TWI912537B - Protective film forming film, composite sheet for forming protective film, method for manufacturing workpiece with protective film, and method for manufacturing workpiece with protective film. - Google Patents

Abstract

The present invention is a protective film forming film (13), a protective film forming composite sheet having a protective film forming film (13), a method for manufacturing a workpiece with a protective film using a protective film forming film (13) or a protective film forming composite sheet, and a method for manufacturing a workpiece with a protective film. Even if there are scratches on the surface of the thermosetting protective film forming film (13), the scratches on the surface of the protective film after thermosetting the protective film forming film (13) can still become inconspicuous.

Description

Protective film forming film, composite sheet for forming protective film, method for manufacturing workpiece with protective film, and method for manufacturing workpiece with protective film.

This invention relates to a protective film forming film, a composite sheet for forming a protective film, a method for manufacturing a workpiece having a protective film, and a method for manufacturing a processed workpiece having a protective film. This application is based on and claims priority to Japanese Patent Application No. 2021-137056 filed in Japan on August 25, 2021, the contents of which are incorporated herein by reference.

In semiconductor wafers or insulator wafers, there are wafers in which a circuit is formed on one side (electrical surface), and bumps or other protruding electrodes are formed on that side (electrical surface). Such wafers are diced into chips, and the protruding electrodes of these chips are connected to bonding pads on a circuit substrate, thus mounting the wafers onto the aforementioned circuit substrate. In order to suppress damage such as cracking, a protective film is sometimes used to protect the side (inner surface) opposite to the electrical surface in such wafers or chips.

To form this protective film, a protective film forming film is attached to the inner surface of the wafer. Sometimes the protective film forming film is deposited on a support sheet to support it, and used as a protective film forming composite; other times it is used without being deposited on the support sheet (see Patent 1). Subsequently, the wafer with the protective film forming film on its inner surface (wafer with protective film forming film) is processed into a chip with a protective film on its inner surface (chip with protective film) through various subsequent steps. During this process, the wafer with the protective film forming film must be transported to a destination location, such as a location for subsequent steps or a storage location.

The aforementioned wafer with a protective film can be manufactured, for example, by the following method: after manufacturing the wafer with the protective film, the wafer is diced to manufacture a wafer, and the protective film is cut off, thereby manufacturing a wafer (a wafer with a protective film) with the cut protective film on its inner surface. After picking up the wafer with the protective film, the cut protective film is then hardened to form the protective film. Alternatively, the cut protective film can be hardened, and after forming the wafer with the protective film, the wafer with the protective film is picked up.

Furthermore, the aforementioned wafer with a protective film can also be manufactured, for example, by: fabricating the wafer with the protective film forming film, hardening the protective film forming film therein to form a protective film, then dicing the wafer to fabricate a wafer, and cutting off the protective film. [Prior Art Documents] [Patent Documents]

[Patent Document 1] International Publication No. 2015/111632.

[Problem to be Solved by the Invention] As the aforementioned protective film forming film, thermosetting protective film forming films can be widely used. These thermosetting protective film forming films are formed by thermosetting through heating. When the thermosetting protective film forming film is attached to the inner surface of a workpiece, a release liner or support sheet is pressed from the side of the protective film forming film opposite to the workpiece side using a pressing mechanism such as a laminating roller. At this time, for example, if particulate foreign matter is mixed between the release liner or support sheet and the laminating roller, sometimes indentations of the particulate foreign matter are formed on the surface of the protective film forming film opposite to the workpiece side.

Taking a wafer with a protective film as an example, when transporting a workpiece with a protective film, the exposed surface of the protective film, opposite to the workpiece side, contacts a transport mechanism, and the transport mechanism transports the workpiece in a fixed state. As such a transport mechanism, there is a known example where the workpiece is fixed by adsorbing it at the contact point between the transport mechanism and the workpiece. When using such a transport mechanism to transport a workpiece with a protective film, contact marks from the transport mechanism (specifically, at the contact point of the fixed portion within the transport mechanism) sometimes form at the fixing point of the protective film (the aforementioned fixing portion). For example, when the aforementioned fixed part is a circular adsorption plate, sometimes circular adsorption marks will form on the exposed surface of the protective film.

Furthermore, if a lifting mechanism such as a pin is used to pick up a wafer with a protective film forming film, sometimes a dent (pin mark) is formed at the lifting point made by the lifting mechanism of the protective film forming film.

The reason why scratches such as indentations, contact marks, adsorption marks, and dents form on the surface of the protective film is because the protective film is relatively soft. Workpieces with this type of scratch that are clearly identifiable not only have aesthetic problems but also raise concerns about reduced laser printing quality. Even after the protective film is thermo-cured to form a protective film, workpieces with the protective film where the scratches are still clearly identifiable have aesthetic problems and raise concerns about reduced laser printing quality. Furthermore, the protective film disclosed in Patent 1 does not necessarily solve these problems.

The purpose of this invention is to provide a protective film forming film, a protective film forming composite sheet having the aforementioned protective film forming film, a method for manufacturing a workpiece with a protective film utilizing the aforementioned protective film forming film or protective film forming composite sheet, and a method for manufacturing a workpiece with a protective film, wherein even when the surface of the thermosetting protective film forming film has scratches, the scratches on the surface of the thermosetting protective film can still be made less noticeable. [Means for solving the problem]

The present invention includes the following aspects. [1] A protective film forming film with thermosetting properties; when a 4 mm wide sample of the aforementioned protective film forming film is held at two locations with a 20 mm interval, and the sample is heated from -50 °C to 150 °C in a stretching mode at a frequency of 11 Hz, a heating rate of 3 °C/min, and a constant heating rate, the storage elastic modulus E’ of the aforementioned sample is measured, and the storage elastic modulus E’(90) of the aforementioned sample is 5 MPa or less before 90 °C. [2] As described in [1], when a 4 mm wide sample of the aforementioned protective film is held at two locations with a 20 mm interval, and the sample is heated from -50 °C to 150 °C in a stretching mode at a frequency of 11 Hz, a heating rate of 3 °C/min, and a constant heating rate, the tanδ of the sample is measured. Before 90 °C, the tanδ(90) of the sample is 0.34 or higher.

[3] As described in [1] or [2], in which a 5 mm wide specimen of the thermocured product of the aforementioned protective film is taken and held at two locations with a 20 mm interval, and the specimen is heated from -60 °C to 300 °C in a stretching mode at a frequency of 11 Hz, a heating rate of 3 °C/min, and a constant heating rate, while the storage elastic modulus E’ of the aforementioned specimen is measured, the storage elastic modulus E’ (23) of the aforementioned specimen is 100 MPa or more before 23 °C. [4] As described in any of [1] to [3], the protective film contains a polymer component (A) comprising acrylic resin; the glass transition temperature of the aforementioned acrylic resin is less than 10 °C. [5] The protective film forming film described in any of [1] to [4] contains filler (D); the content of the filler (D) is less than 50% of the total mass of the protective film forming film.

[6] A composite sheet for forming a protective film has a support sheet and a protective film forming film disposed on one side of the support sheet; the protective film forming film is the protective film forming film described in any one of [1] to [5].

[7] A method for manufacturing a workpiece with a protective film, wherein the workpiece with a protective film comprises a workpiece and a protective film disposed at any location of the workpiece; the manufacturing method comprises the following steps: an attachment step, wherein a protective film forming film as described in any of [1] to [5] or a protective film forming composite sheet as described in [6] is attached to a target portion of the workpiece, thereby producing a workpiece with a protective film forming film comprising the workpiece and the protective film forming film; a thermosetting step, wherein after the attachment step, the protective film forming film is thermoset to form the protective film, thereby producing the workpiece with the protective film. [8] A method for manufacturing a workpiece having a protective film, wherein the workpiece having a protective film comprises a workpiece obtained by processing a workpiece and a protective film disposed at any location on the workpiece; the manufacturing method comprises the following steps: an attachment step, wherein a protective film forming film as described in any of [1] to [5], or a protective film forming composite sheet as described in [6], is attached to a target area of the workpiece, thereby producing a workpiece having the workpiece and the protective film forming film; a processing step, wherein after the attachment step, the workpiece is processed to produce the workpiece; and a thermosetting step, wherein after the attachment step, the protective film forming film is thermoset to form the protective film. [Invention Benefits]

According to the present invention, a protective film forming film, a protective film forming composite sheet having the aforementioned protective film forming film, a method for manufacturing a workpiece with a protective film utilizing the aforementioned protective film forming film or protective film forming composite sheet, and a method for manufacturing a workpiece with a protective film are provided. Even if the heat-curable protective film forming film has scratches on its surface, the scratches on the surface of the protective film after heat curing can still be made less noticeable.

◇Protective Film Forming Membrane One embodiment of the present invention is a thermosetting protective film forming membrane. A 4mm wide sample of the aforementioned protective film forming membrane is held at two locations with a 20mm interval. While the sample is heated from -50℃ to 150℃ in a stretching mode at a frequency of 11Hz, a heating rate of 3℃/min, and a constant heating rate, the storage elastic modulus E’ of the sample is measured. At 90℃, the storage elastic modulus E’(90) of the sample is 5MPa or less. The protective film forming membrane of this embodiment can, for example, be laminated with a support sheet to form a composite sheet for forming a protective film, as described later.

By utilizing the protective film forming film of this embodiment, or a protective film forming composite sheet having the protective film forming film of this embodiment, a workpiece having a protective film can be manufactured, consisting of a workpiece and a protective film disposed at any location on the aforementioned workpiece. Furthermore, a workpiece processing object having a protective film can be manufactured, consisting of a workpiece processing object and a protective film disposed at any location on the aforementioned workpiece processing object. For example, when the workpiece is a wafer, by utilizing the aforementioned protective film forming film or protective film forming composite sheet, a wafer having a protective film can be manufactured, consisting of a wafer and a protective film disposed on the inner surface of the aforementioned wafer.

In this embodiment, the workpiece can be exemplified by, for example, a semiconductor wafer or a semiconductor device panel. A semiconductor device panel is something manipulated during the manufacturing process of a semiconductor device. Specific examples of such a semiconductor device panel include: a semiconductor device panel constructed by planarly arranging multiple semiconductor devices within a circular, rectangular, or other shaped area, using one or more electronic components sealed with sealing resin. In this specification, the article formed by processing the workpiece is referred to as a "workpiece processed item." For example, when the workpiece is a semiconductor wafer, a semiconductor chip can be exemplified as a workpiece processed item.

In this specification, the term "wafer" can include: semiconductor wafers composed of elemental semiconductors such as silicon, germanium, and selenium, or compound semiconductors such as GaAs, GaP, InP, CdTe, ZnSe, and SiC; and insulating wafers composed of insulators such as sapphire, glass, lithium niobate, and lithium tantalum. Electrical circuits are formed on one side of these wafers; in this specification, the side of the wafer with the electrical circuits formed is called the "electrical surface." The side of the wafer opposite to the electrical surface is called the "inner surface." Wafers are processed (divided) into chips by means of dicing or other methods. In this specification, similar to the case of a wafer, the side of the chip where the circuit is formed is referred to as the "surface surface," and the side of the chip opposite to the surface surface is referred to as the "inner surface." Both the surface surfaces of the wafer and the surface surfaces of the chip are preferably provided with protruding electrodes such as bumps and pillars. These protruding electrodes are preferably made of solder.

Furthermore, by utilizing the aforementioned chip with a protective film, a substrate device can be manufactured. In this specification, the term "substrate device" refers to a substrate device formed by flip-chip bonding of a workpiece with a protective film to a bonding pad on a circuit substrate in the protruding electrodes on the electrical surface of the workpiece. For example, if a semiconductor wafer is used as the workpiece, a semiconductor device formed by flip-chip bonding of a semiconductor chip with a protective film can be cited as an example of a substrate device.

The protective film forming film of this embodiment is formed by the fact that the storage elastic modulus E’(90) of the aforementioned test piece is less than 5MPa before 90°C. Therefore, even if there are scratches on the surface of the thermosetting protective film forming film during the process of manufacturing the aforementioned workpiece with a protective film or the aforementioned workpiece with a protective film using the protective film forming film of this embodiment, the scratches on the surface of the protective film after thermosetting can still become inconspicuous. The protective film formation of this embodiment is achieved by using a storage elastic modulus E’(90) of less than 5 MPa for the aforementioned test piece before 90°C. When the protective film is heat-cured to form a protective film, the fluidity of the protective film is greater at 90°C before heat curing than at room temperature. This can repair the damage on the surface of the protective film. In other words, it can be considered that due to the excellent self-healing properties of the protective film formed in this embodiment, the damage on the surface of the protective film becomes less noticeable. In this specification, "room temperature" means a temperature that is neither particularly cold nor particularly hot, that is, a normal temperature, such as temperatures from 15°C to 25°C.

The protective film of this embodiment has a storage elastic modulus E’(90) of 5 MPa or less, preferably 3 MPa or less, more preferably 2 MPa or less, even more preferably 0.4 MPa or less, and even more preferably 0.2 MPa or less when the protective film is formed at 90°C.

The protective film forming film of this embodiment is thermosetting, and performs its function as a protective film through thermosetting. The protective film forming film is produced by heating a room-temperature protective film forming film to a temperature above 100°C and then cooling it back to room temperature. When the hardness of the heated and cooled protective film forming film is compared with the hardness of the unheated protective film forming film at the same temperature, and the heated and cooled protective film forming film is harder, the protective film forming film is thermosetting.

The protective film formed in this embodiment preferably has the property of not hardening at 90°C, but softening instead. That is, when the test piece with a width of 4 mm of the aforementioned protective film is held at two locations with a 20 mm interval, and the test piece is heated from -50°C to 150°C in a stretching mode at a frequency of 11 Hz, a heating rate of 3°C/min, and a constant heating rate, while the storage elastic modulus E’ of the aforementioned test piece is measured, the storage elastic modulus E’(90) of the aforementioned test piece is preferably less than the storage elastic modulus E’(70) of the aforementioned test piece at 70°C.

The protective film of this embodiment preferably has a storage elastic modulus E’(70) of 8 MPa or less before 70°C, more preferably 3.5 MPa or less, even more preferably 3 MPa or less, and most preferably 2 MPa or less.

The protective film forming film of this embodiment is formed by holding two 4mm wide test pieces of the aforementioned protective film forming film at 20mm intervals. The test pieces are heated from -50℃ to 150℃ in a stretching mode at a frequency of 11Hz, a heating rate of 3℃/min, and a constant heating rate. While measuring the tanδ of the test pieces, the tanδ (90) of the test pieces before 90℃ is preferably 0.20 or higher, more preferably 0.24 or higher, and even more preferably 0.34 or higher. Because the tanδ (90) value of the test pieces before 90℃ is above the aforementioned lower limit, the protective film forming film tends to have excellent self-repairing properties. This is presumably due to the increased contribution of the viscous components of the protective film forming film at 90℃.

The protective film forming membrane of this embodiment is formed by holding two 4mm wide test pieces of the aforementioned protective film forming membrane at 20mm intervals. The test pieces are heated from -50℃ to 150℃ in a stretching mode at a frequency of 11Hz, a heating rate of 3℃/min, and a constant heating rate. While measuring the tanδ of the test pieces, the tanδ (70) of the test pieces at 70℃ is preferably 0.35 or higher, more preferably 0.40 or higher, and even more preferably 0.50 or higher. Because the tanδ (70) value of the test pieces at 70℃ is above the aforementioned lower limit, the protective film forming membrane tends to have excellent self-repairing properties. This is presumably due to the increased contribution of the viscous components of the protective film forming membrane at 70℃.

A 5mm wide specimen of the thermocured material formed by heating and curing the protective film of this embodiment was taken and held at two locations with a 20mm interval. The specimen was heated from -60℃ to 300℃ in a stretching mode at a frequency of 11Hz, a heating rate of 3℃/min and a constant heating rate. At the same time, the storage elastic modulus E’ of the specimen was measured. The storage elastic modulus E’ (23) of the specimen before 23℃ is preferably 100MPa or more, more preferably 200MPa or more, and even more preferably 300MPa or more. If the storage elastic modulus E’(23) of the heat-cured protective film is too low, when the workpiece with protective film, such as a wafer with protective film, is packaged on a carrier belt and transported, the soft protective film may collide with the inner wall of the carrier belt, causing scratches or dents. Moreover, in the step of picking up the wafer with protective film after curing, a higher storage elastic modulus E’(23) of the heat-cured protective film can reduce needle marks during picking.

The protective film can be composed of a single layer or multiple layers. When the protective film is composed of multiple layers, these layers can be the same or different from each other, and there is no particular limitation on the combination of these layers. From the perspective of ease of control of the storage elastic modulus E' and manufacturing cost, the protective film is preferably composed of a single layer.

In this manual, the term "multiple layers may be the same or different from each other" is not limited to the case of protective film formation. It means that "all layers may be the same, all layers may be different, or only some layers may be the same." Furthermore, the term "multiple layers are different from each other" means that "at least one of the constituent materials and thicknesses of each layer is different from each other."

The storage elastic modulus E' of the protective film forming film specimen can be determined by laminating multiple of the aforementioned protective film forming films and cutting them out to produce a laminate with a width of 4 mm, and using the laminate as a specimen for measurement.

The storage elastic modulus E' of the protective film specimen can be determined by laminating multiple sheets of the aforementioned protective film forming film and cutting them out to create a laminate with a width of 5 mm. This laminate is then heated and hardened to form a protective film laminate, which is then used as a specimen for measurement. Alternatively, the storage elastic modulus E' of the protective film can be determined by laminating multiple sheets of the aforementioned protective film forming film and heating and hardening them to create a protective film. This laminate is then cut out to create a laminate with a width of 4 mm, which is then used as a specimen for measurement.

More specifically, the aforementioned test piece was held at two locations with a 20mm interval. While holding the test piece at this location, the temperature was increased at a constant rate of 3℃/min from -10℃ to 170℃, and the storage elastic modulus E' of the test piece was measured at a frequency of 11Hz. The phrase "held at two locations with a 20mm interval" means that the length of the portion of the test piece used to measure the storage elastic modulus E' is 20mm.

The aforementioned test piece can be held at the aforementioned two locations using, for example, a known holding mechanism such as a clamp.

The thickness of the aforementioned test piece (layer) is not particularly limited, as long as it does not hinder the implementation of the aforementioned test and does not impair the accuracy of the measurement of the aforementioned storage elastic modulus E’. Generally, the thickness of the aforementioned test piece is preferably 190 μm to 210 μm, more preferably 195 μm to 205 μm, and even more preferably 200 μm.

There is no particular limitation on the number of protective film sheets constituting the aforementioned test piece, and they can be arbitrarily selected according to the thickness of each protective film sheet. For example, the aforementioned test piece can be made by using 5 protective film sheets or protective films with a thickness of 40 μm. However, this is just one example, and the number and thickness of the protective film sheets or protective films used are not limited thereto.

The storage elastic modulus E’(90) and storage elastic modulus E’(70) of the aforementioned test piece can be adjusted by adjusting the type and content of the components contained in the aforementioned protective film forming film. For example, when the protective film forming film contains the polymer component (A) described later, the storage elastic modulus E’ of the test piece can be adjusted more easily by adjusting the type and amount of the constituent units of the polymer component (A). More specifically, for example, by using an acrylic resin having a certain amount or more of constituent units derived from 2-ethylhexyl acrylate as the polymer component (A) and adjusting the content of the acrylic resin, the storage elastic modulus E’ of the test piece can be adjusted more easily.

When the polymer component (A) contains acrylic resin, the storage elastic modulus E’ of the sample can be more easily adjusted by adjusting the glass transition temperature of the acrylic resin. The lower the glass transition temperature of the acrylic resin, the smaller the storage elastic modulus E’(90) and storage elastic modulus E’(70) of the sample tend to be. Moreover, when the protective film forming film contains the filler (D) described later, the storage elastic modulus E’(90) and storage elastic modulus E’(70) of the sample can be more easily adjusted by using surface-modified spherical filler (D) to adjust the average particle size and content. Typically, the larger the average particle size of the filler (D), the smaller the storage elastic modulus E’(90) and storage elastic modulus E’(70) of the specimen tend to be.

The thickness of the protective film is preferably less than 50 μm, and more preferably less than 45 μm.

In terms of the thickness of the protective film, which can form a protective film with higher protective performance, it is preferably 10μm or more, more preferably 15μm or more, and for example, it can also be 20μm or more.

The thickness of the protective film can be appropriately adjusted within a range set by arbitrarily combining any of the above-mentioned upper and lower limits. For example, in one embodiment, the thickness of the protective film can be either 5 μm or more but less than 50 μm, or 5 μm or more but less than 45 μm.

In this specification, the term "thickness of the protective film" refers to the overall thickness of the protective film. For example, the term "thickness of a protective film composed of multiple layers" refers to the total thickness of all the layers that make up the protective film.

In this manual, not limited to the case of protective film formation, the term "thickness" unless otherwise specified is the average value of the thickness measured at 5 randomly selected locations on the object, which can be obtained using a constant pressure thickness gauge according to JIS (Japanese Industrial Standards) K7130.

In this embodiment, the thermocured material obtained by heating the aforementioned protective film is preferably used as a protective film.

When the aforementioned protective film is attached to the target area of the wafer and thermally cured to form the protective film, there are no particular limitations on the curing conditions, as long as the protective film is cured to the extent that it can fully perform its function. It can be appropriately selected according to the type of protective film.

For example, the heating temperature for the thermosetting of the protective film is preferably 100°C to 180°C, more preferably 110°C to 160°C, and even more preferably 120°C to 140°C. In addition, the heating time for the aforementioned thermosetting is preferably 0.5h to 5h, more preferably 0.5h to 4h, and even more preferably 1h to 3h.

[Composition for forming a protective film] The aforementioned protective film forming film can be formed using a composition for forming a protective film (more specifically, a thermosetting composition for forming a protective film) containing the constituent material of the protective film forming film. For example, the protective film forming film can be formed by applying the composition for forming a protective film to the object surface of the protective film forming film and drying it as needed.

The aforementioned protective film can also have energy line curing properties in addition to thermocuring properties.

In this manual, the term "energy line" refers to electromagnetic waves or beams of charged particles containing energy quanta. Examples of energy lines include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be emitted by irradiating objects using high-pressure mercury lamps, fusion lamps, xenon lamps, black light, or LED (Light Emitting Diode) lamps. Electron beams can be emitted by irradiating objects produced by electron beam accelerators. In this manual, "energy line hardening property" refers to the property of hardening by irradiation of energy lines, while "non-energy line hardening property" refers to the property of not hardening even when irradiated with energy lines.

In the protective film forming film, the percentage of the total content of one or more of the following ingredients in the protective film forming film does not exceed 100% by mass relative to the total mass of the protective film forming film. Similarly, in the protective film forming composition, the percentage of the total content of one or more of the following ingredients in the protective film forming composition does not exceed 100% by mass relative to the total mass of the protective film forming composition.

The coating of the protective film forming component can be carried out by known methods, such as: using air knife coating machine, doctor blade coating machine, rod coating machine, gravure coating machine, roller coating machine, roller blade coating machine, curtain coating machine, die coating machine, knife coating machine, screen coating machine, Meyer bar coating machine, touch coating machine, and other coating machine methods.

There are no particular limitations on the drying conditions of the protective film forming composition. However, when the protective film forming composition contains the solvent described later, heat drying is preferred. Furthermore, the protective film forming composition containing the solvent is preferably heat-dried at 70°C to 130°C for 10 seconds to 5 minutes. However, since the protective film forming composition is thermosetting, it is preferable to heat-dry it in a manner that neither the composition itself nor the thermosetting protective film formed by the composition undergoes thermosetting.

As a preferred protective film forming film, an example is a protective film forming film containing a polymer component (A), a thermosetting component (B), and a filler (D). The polymer component (A) is a component that is considered to be formed by the polymerization reaction of a polymeric compound. The thermosetting component (B) is a component that can undergo a curing (polymerization) reaction triggered by heat. Furthermore, in this specification, the polymerization reaction also includes a condensation reaction. The composition of the protective film forming component will be explained in detail below.

[Composition for forming protective film (III)] As a preferred composition for forming protective film, examples include: composition (III) for forming protective film containing the aforementioned polymer component (A), thermosetting component (B) and filler (D) (sometimes referred to as "composition (III)" in this specification).

[Polymer Component (A)] Polymer component (A) is a polymer compound used to impart film-forming properties or flexibility to the protective film. Furthermore, in this specification, the polymer compound also includes products of the condensation reaction.

The polymer component (A) contained in the composition (III) and the protective film forming film may be only one type or two or more types. In the case of two or more types, the combination and ratio of these polymer components (A) may be arbitrarily selected.

As a polymer component (A), examples include: acrylic resin, amino formaldehyde resin, phenoxy resin, polysiloxane resin, saturated polyester resin, etc., with acrylic resin being preferred.

As the aforementioned acrylic resin in polymer component (A), known acrylic polymers can be listed. The weight-average molecular weight (Mw) of the acrylic resin is preferably from 10,000 to 2,000,000, more preferably from 100,000 to 1,500,000, further preferably from 200,000 to 1,200,000, and even more preferably from 300,000 to 1,000,000. By having a weight-average molecular weight of the acrylic resin above the aforementioned lower limit, it is easier to impart film-forming properties. By having a weight-average molecular weight of the acrylic resin below the aforementioned upper limit, it is easier to reduce the aforementioned storage elastic modulus E’(90) and the aforementioned storage elastic modulus E’(70).

In this manual, the term "weight average molecular weight" refers to the polystyrene equivalent determined by gel osmosis chromatography (GPC) unless otherwise specified.

The glass transition temperature (Tg) of the acrylic resin is preferably above -80°C to below 10°C, more preferably above -70°C to below 5°C, even more preferably above -60°C to below 0°C, and particularly preferably above -60°C to below -5°C. By having the Tg of the acrylic resin above the aforementioned lower limit, the adhesion between the thermosetting material of the protective film and the support sheet is inhibited, for example, and the peelability of the support sheet is appropriately improved. By having the Tg of the acrylic resin below the aforementioned upper limit, it is easier to reduce the aforementioned storage elastic modulus E’(90) and the aforementioned storage elastic modulus E’(70).

Acrylic resin has m types of constituent units (m is an integer greater than 2). When the m types of monomers from which these constituent units are derived are assigned a unique number from 1 to m and named "monomer m", the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox formula shown below.

(In the formula, Tg is the glass transition temperature of acrylic resin; m is an integer greater than or equal to 2; _Tgk is the glass transition temperature of the homopolymer of monomer m; _Wk is the mass fraction of the constituent unit m derived from monomer m in acrylic resin, wherein _Wk satisfies the following formula).

(In the formula, m and _Wk are the same as those mentioned above).

The aforementioned Tg _k can be the value recorded in polymer data manuals, adhesive manuals, or polymer handbooks. For example, the Tg _k of methyl acrylate homopolymer is 10°C, the Tg _k of methyl methacrylate homopolymer is 105°C, the Tg _k of 2-hydroxyethyl acrylate homopolymer is -15°C, the Tg _k of glycidyl methacrylate homopolymer is 41°C, the Tg _k of 2-ethylhexyl acrylate homopolymer is -70°C, the Tg _k of acrylic acid homopolymer is 103°C, the Tg _k of acrylonitrile homopolymer is 97°C, the Tg _k of n-butyl acrylate homopolymer is -54°C, the Tg _k of 2-ethylhexyl methacrylate homopolymer is -10°C, and the Tg _k of ethyl acrylate homopolymer is -24°C.

Examples of acrylic resins include: polymers of one or more (meth)acrylates; copolymers of two or more monomers selected from the aforementioned (meth)acrylates, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-hydroxymethylacrylamide. When the acrylic resin consists of two or more monomers, the combination and ratio of these monomers can be arbitrarily selected.

As constituents of acrylic resins, the aforementioned (meth)acrylates include, for example: methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, dibutyl (meth)acrylate, terbutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, and so on. (Meth)octyl acrylate, (Meth)nonyl acrylate, (Meth)isononyl acrylate, (Meth)decyl acrylate, (Meth)undecyl acrylate, (Meth)dodecyl acrylate ((Meth)lauryl acrylate), (Meth)tridecyl acrylate, (Meth)tetradecyl acrylate ((Meth)myristyl acrylate), (Meth)pentadecanyl acrylate, (Meth)hexadecyl acrylate ((Meth)palmitoyl acrylate), (Meth)heptadecyl acrylate, (Meth)oct ... Alkyl methacrylates, such as octadecyl acrylate ((meth)acrylate stearate), etc., in which the alkyl group has a chain structure with 1 to 18 carbon atoms; cycloalkyl methacrylates, such as isobornyl methacrylate and dicyclopentyl methacrylate; aralkyl methacrylates, such as benzyl methacrylate; cycloalkenyl methacrylates, such as dicyclopentenyl methacrylate; cycloalkenyl methacrylates, such as dicyclopentenoxyethyl methacrylate; cycloalkenoxyalkyl methacrylates, such as dicyclopentenoxyethyl methacrylate; Acrylimide; glycidyl acrylate and other (meth)acrylates containing glycidyl groups; hydroxymethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate and other (meth)acrylates containing hydroxyl groups; N-methylaminoethyl methacrylate and other (meth)acrylates containing substituted amino groups. Here, "substituted amino group" refers to a structural group having one or two hydrogen atoms of an amino group substituted with a group other than a hydrogen atom.

In this specification, the term "(meth)acrylic acid" includes both "acrylic acid" and "methacrylic acid". Similarly, similar terms include "(meth)acrylic acid", which includes both "acrylic" and "methacrylic", and "(meth)acrylate", which includes both "acrylate" and "methacrylate".

Acrylic resins may also possess functional groups such as vinyl, (meth)acrylic, amino, hydroxyl, carboxyl, and isocyanate groups, which can bond with other compounds. The aforementioned functional groups of acrylic resins can bond with other compounds through the crosslinking agent (F) described later, or they can bond directly with other compounds without the crosslinking agent (F).

As an example of a better acrylic resin, one can be listed: acrylic resin (α) having a constituent unit derived from 2-ethylhexyl acrylate.

In the aforementioned acrylic resin (α), the ratio (content) of the constituent units derived from the aforementioned 2-ethylhexyl acrylate relative to the total amount of the constituent units constituting the acrylic resin (α) is preferably 10% by mass to 90% by mass, for example, it can be any one of 25% by mass to 85% by mass, 40% by mass to 80% by mass, and 50% by mass to 75% by mass.

In this invention, the polymer component (A) may be a thermoplastic resin other than acrylic resin (hereinafter, sometimes simply referred to as "thermoplastic resin"), or it may be used in combination with acrylic resin. By using the aforementioned thermoplastic resin, the peelability of the protective film from the self-supporting sheet is sometimes improved, or the protective film forms a film that easily follows the uneven surface of the adhered object.

The weight-average molecular weight of the aforementioned thermoplastic resin is preferably between 1,000 and 100,000, and more preferably between 3,000 and 80,000.

The glass transition temperature (Tg) of the aforementioned thermoplastic resin is preferably -30°C to 150°C, and more preferably -20°C to 120°C.

Examples of the aforementioned thermoplastic resins include: polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, polystyrene, etc.

The thermoplastic resin contained in component (III) and the protective film forming film may be only one type or two or more types. In the case of two or more types, the combination and ratio of these thermoplastic resins may be arbitrarily selected.

In composition (III), regardless of the type of polymer component (A), the content of polymer component (A) relative to the total content of all components other than the solvent is preferably from 10% to 85% by mass, more preferably from 15% to 70% by mass, for example, it can be any one of 15% to 45% by mass and 15% to 35% by mass, or any one of 20% to 70% by mass and 25% to 70% by mass. This content has the same meaning as the following: In the protective film forming membrane, regardless of the type of polymer component (A), the content ratio of polymer component (A) relative to the total mass of the protective film forming membrane is preferably 10% to 85% by mass, more preferably 15% to 70% by mass, for example, any one of 15% to 45% by mass and 15% to 35% by mass, or any one of 20% to 70% by mass and 25% to 70% by mass. This is based on the fact that: in the process of removing the solvent from the resin composition containing the solvent to form a resin film, the amount of components other than the solvent usually does not change; and in the resin composition and the resin film, the content ratio of components other than the solvent is the same. Therefore, in this specification, the following is not limited to the case of protective film formation. The content of components other than solvent is only recorded in the resin film after the solvent has been removed from the resin composition.

Polymer component (A) is sometimes equivalent to thermosetting component (B). In this invention, when composition (III) contains such a component that is equivalent to both polymer component (A) and thermosetting component (B), composition (III) is deemed to contain both polymer component (A) and thermosetting component (B).

[Thermosetting Component (B)] Thermosetting component (B) is a component used to harden the protective film forming membrane. The thermosetting component (B) contained in composition (III) and the protective film forming membrane may be only one type or two or more types. In the case of two or more types, the combination and ratio of these thermosetting components (B) can be arbitrarily selected.

Examples of thermosetting components (B) include epoxy thermosetting resins, thermosetting polyimide resins, and unsaturated polyester resins, with epoxy thermosetting resins being preferred. In this specification, the term "thermosetting polyimide resin" refers to both the polyimide precursors that form polyimide resins through thermosetting and the thermosetting polyimides themselves.

[Epoxy Thermosetting Resin] The epoxy thermosetting resin is composed of epoxy resin (B1) and thermosetting agent (B2). The epoxy thermosetting resin contained in component (III) and the protective film forming film may be only one type or two or more types. In the case of two or more types, the combination and ratio of these epoxy thermosetting resins can be arbitrarily selected.

• Epoxy resins (B1) As epoxy resins (B1), known epoxy resins can be listed, such as: multifunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenates, o-cresol phenolic varnish epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenyl skeleton type epoxy resins, and other epoxy compounds with more than two functions.

As an epoxy resin (B1), epoxy resins with unsaturated hydrocarbon groups can also be used.

The number-average molecular weight of the epoxy resin (B1) is not particularly limited, but in terms of the curability of the protective film, as well as the strength and heat resistance of the protective film, it is preferably 300 to 30,000, more preferably 300 to 10,000, and even more preferably 300 to 3,000. The epoxy equivalent of the epoxy resin (B1) is preferably 100 g/eq to 1,000 g/eq, more preferably 150 g/eq to 950 g/eq.

Epoxy resin (B1) can be used alone or in combination with two or more. When two or more are used together, the combination and ratio of these epoxy resins (B1) can be arbitrarily selected.

• Thermosetting Agent (B2) Thermosetting agent (B2) functions as a curing agent for epoxy resin (B1). Examples of thermosetting agents (B2) include compounds having two or more functional groups capable of reacting with epoxy groups in a single molecule. Examples of the aforementioned functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups formed by anhydride conversion of acid groups. Phenolic hydroxyl groups, amino groups, or groups formed by anhydride conversion of acid groups are preferred, and phenolic hydroxyl groups or amino groups are even more preferred.

Among thermosetting agents (B2), phenolic curing agents containing phenolic hydroxyl groups include, for example, polyfunctional phenolic resins, biphenol, phenolic varnish-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Among thermosetting agents (B2), amine curing agents containing amino groups include, for example, dicyandiamine.

Thermosetting agents (B2) may also have unsaturated hydrocarbon groups.

When using a phenolic curing agent as a thermosetting agent (B2), the thermosetting agent (B2) is preferably one with a high softening point or glass transition temperature, in terms of improving the peelability of the protective film's self-supporting sheet.

In the thermosetting agent (B2), the average molecular weight of resin components such as polyfunctional phenolic resins, phenolic varnish-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins is preferably 300 to 30,000, more preferably 400 to 10,000, and even more preferably 500 to 3,000. The molecular weight of non-resin components in the thermosetting agent (B2), such as biphenol and dicyandiamine, is not particularly limited, but is preferably 60 to 500.

The thermosetting agent (B2) can be used alone or in combination with two or more. When two or more are used together, the combination and ratio of these thermosetting agents (B2) can be arbitrarily selected.

In the protective film forming film, the content of thermosetting agent (B2) is preferably 0.1 to 100 parts by mass relative to 100 parts by mass of epoxy resin (B1), more preferably 0.5 to 50 parts by mass, and for example, any one of 0.5 to 25 parts by mass, 0.5 to 10 parts by mass, and 0.5 to 5 parts by mass. By having the aforementioned content of thermosetting agent (B2) at or above the aforementioned lower limit, the curing of the protective film forming film is easier. By having the aforementioned content of thermosetting agent (B2) at or below the aforementioned upper limit, the moisture absorption rate of the protective film forming film is reduced, further improving the reliability of the encapsulation obtained using the protective film forming film.

In the protective film forming film, relative to the total content of polymer component (A) and thermosetting component (B) of 100 parts by mass, the content of thermosetting component (B) (e.g., the total content of epoxy resin (B1) and thermosetting agent (B2)) is preferably 10 to 100 parts by mass, more preferably 20 to 70 parts by mass, even more preferably 25 to 55 parts by mass, and particularly preferably 30 to 45 parts by mass. By having the aforementioned content of thermosetting component (B) above the aforementioned lower limit, it is easier, for example, to increase the storage elastic modulus E’ (23) of the thermosetting protective film. By having the aforementioned content of thermosetting component (B) below the aforementioned upper limit, it is easier, for example, to decrease the aforementioned storage elastic modulus E’ (90).

[Fill (D)] Composition (III) and the protective film forming film preferably contain filler (D). By containing filler (D) in the protective film forming film, the storage elastic modulus E' of the aforementioned test piece can be adjusted more easily. More specifically, by adjusting the average particle size of the filler (D) contained in the protective film forming film and the content of the filler (D) in the protective film forming film, the storage elastic modulus E' of the aforementioned test piece can be adjusted more easily. Moreover, by containing filler (D) in the protective film forming film, the adjustment of the coefficient of thermal expansion of the protective film forming film and the protective film becomes easier, and by optimizing the coefficient of thermal expansion relative to the forming object of the protective film, the reliability of the wafer with the protective film obtained by using the protective film forming film is further improved. Furthermore, by using a protective film containing filler (D), the moisture absorption rate of the protective film can be reduced, or its heat dissipation can be improved.

The filler (D) can be either organic or inorganic, preferably inorganic. Examples of preferred inorganic fillers include: powders of silicon dioxide, alumina, talc, calcium carbonate, titanium dioxide, iron oxide, silicon carbide, boron nitride, etc.; beads obtained by spheroidizing these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; glass fibers, etc. Among these, the inorganic filler is preferably silicon dioxide or alumina, more preferably silicon dioxide.

Regarding the improvement of the dispersibility of the filler (D) in the composition for forming the protective film on components other than the filler (D), the aforementioned silica is preferably silica with an organic surface modification, more preferably silica with a vinyl, epoxy, phenyl or methacrylate surface modification, and even more preferably silica with a vinyl or epoxy surface modification.

Regarding the improvement of the dispersibility of the filler (D) in the composition for forming the protective film to components other than the filler (D), the average particle size of the filler (D) is preferably 0.05 μm to 2 μm, more preferably 0.2 μm to 0.9 μm, and even more preferably 0.4 μm to 0.7 μm. By having the average particle size of the filler (D) at or above the aforementioned lower limit, there is a tendency to further reduce the aforementioned storage elastic modulus E’(90) and storage elastic modulus E’(70).

In this manual, unless otherwise specified, "average particle size" refers to the particle size ( _D50 ) at 50% of the cumulative value in the particle size distribution curve obtained by laser diffraction.

The filler (D) contained in the composition (III) and the protective film forming film may be one or more types. In the case of two or more types, the combination and ratio of these fillers (D) can be arbitrarily selected.

When using filler (D), the content of filler (D) in the protective film forming film is preferably 30% to 70% by mass relative to the total mass of the protective film forming film. For example, it can be any one of 35% to 70% by mass, 35% to 65% by mass, and 35% to 59% by mass, or 35% to less than 50% by mass. By using the above-mentioned ratio within this range, it becomes easier to adjust the above-mentioned storage elastic modulus E’ (90), the above-mentioned storage elastic modulus E’ (70), and the storage elastic modulus E’ (23) of the thermosetting protective film to the above-mentioned range. In the protective film forming film, the content of filler (D) relative to the total mass of the protective film forming film is preferably 40% to 70% by mass, for example, it can be any one of 45% to 70% by mass, 45% to 65% by mass, and 45% to 59% by mass, or it can be 45% to less than 50% by mass.

[Curving Accelerator (C)] The component (III) and the protective film forming film may also contain a curing accelerator (C). The curing accelerator (C) is a component used to adjust the curing rate of the component (III). Examples of preferred hardening accelerators (C) include: tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organophosphines (phosphines in which one or more hydrogen atoms are substituted with organic groups) such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylborates such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

The curing accelerator (C) contained in the composition (III) and the protective film forming film may be one or more. In the case of two or more, the combination and ratio of these curing accelerators (C) may be arbitrarily selected.

When using a curing accelerator (C), in the protective film forming film, the content of the curing accelerator (C) is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of the thermosetting component (B), and more preferably 0.1 to 7 parts by mass. By having the content of the curing accelerator (C) above the aforementioned lower limit, the effects obtained by using the curing accelerator (C) are more significantly obtained, and the storage elastic modulus E’(23) of the thermosetting protective film is more easily increased. By having the content of the curing accelerator (C) below the aforementioned upper limit, for example, the effect of inhibiting the highly polar curing accelerator (C) from migrating to the interface with the adherend in the protective film forming film under high temperature and high humidity conditions and segregating therein is improved. As a result, the reliability of the wafer with protective film obtained by forming a protective film is further improved.

[Coupling Agent (E)] Composition (III) and the protective film forming film may also contain a coupling agent (E). By using a coupling agent (E) having functional groups that can react with inorganic or organic compounds, the adhesion of the protective film formed by the protective film forming film to the substrate can be improved. Moreover, by using a coupling agent (E), the water resistance can be improved without compromising the aforementioned heat resistance of the protective film.

The coupling agent (E) is preferably a compound having a functional group that can react with the functional groups of the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent.

Preferred silane coupling agents include, for example: 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and 3-(2-aminoethylamino)propyltrimethoxysilane. Silane, 3-(2-aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinepropyltrimethoxysilane, 3-ureopropyltriethoxysilane, 3-caprylylpropyltrimethoxysilane, 3-caprylylpropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, imidazolylsilane, etc.

As a preferred alternative to the aforementioned silane coupling agents, oligomeric silane coupling agents having multiple alkoxysilane groups per molecule can also be listed. These oligomeric silane coupling agents are less volatile and have multiple alkoxysilane groups per molecule, thus they are superior in terms of effectively improving durability. Examples of the aforementioned oligomeric silane coupling agents include: "X-41-1053", "X-41-1059A", "X-41-1056" and "X-40-2651" (all manufactured by Shin-Etsu Chemical Co., Ltd.) which are epoxy-containing oligomeric silane coupling agents; and "X-41-1818", "X-41-1810" and "X-41-1805" (all manufactured by Shin-Etsu Chemical Co., Ltd.) which are guanidine-containing oligomeric silane coupling agents.

The coupling agent (E) contained in the composition (III) and the protective film forming film may be only one or more. In the case of two or more, the combination and ratio of these coupling agents (E) may be arbitrarily selected.

When using a coupling agent (E), in the protective film forming film, relative to 100 parts by mass of the total content of polymer component (A) and thermosetting component (B), the content of coupling agent (E) is preferably 0.03 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 2 parts by mass. By having the aforementioned content of coupling agent (E) at or above the aforementioned lower limit, the effects obtained by using coupling agent (E), such as improved dispersibility of filler (D) in resin or improved adhesion between the protective film forming film and the substrate, are more significantly obtained. By having the aforementioned content of coupling agent (E) at or below the aforementioned upper limit, the generation of gas escape is further suppressed.

[Crosslinking Agent (F)] When using the above-mentioned acrylic resin or other components having functional groups such as vinyl, (meth)acrylic, amino, hydroxyl, carboxyl, and isocyanate groups that can bond with other compounds as polymer component (A), the composition (III) and the protective film forming film may also contain a crosslinking agent (F). The crosslinking agent (F) is a component used to crosslink the aforementioned functional groups in polymer component (A) with other compounds, thereby regulating the adhesion and cohesion of the protective film forming film.

Examples of crosslinking agents (F) include: organic polyisocyanate compounds, organic polyimine compounds, metal chelate crosslinking agents (crosslinking agents with metal chelate structures), aziridine crosslinking agents (crosslinking agents with aziridine groups), etc.

The crosslinking agent (F) contained in the component (III) and the protective film forming film may be only one type or two or more types. In the case of two or more types, the combination and ratio of these crosslinking agents (F) may be arbitrarily selected.

Regarding reducing the aforementioned storage elastic modulus E’(90) and the aforementioned storage elastic modulus E’(70), it is preferable that composition (III) does not contain crosslinking agent (F), or that in composition (III), the content of crosslinking agent (F) is, for example, less than 0.01 parts by mass relative to 100 parts by mass of polymer component (A), that is, the content of crosslinking agent (F) is low. In contrast, when using a certain amount or more of crosslinking agent (F), in composition (III), the content of crosslinking agent (F) is preferably 0.01 parts by mass to 20 parts by mass relative to 100 parts by mass of polymer component (A), more preferably 0.1 parts by mass to 10 parts by mass, and even more preferably 0.5 parts by mass to 5 parts by mass. By having the crosslinking agent (F) at a level above the aforementioned lower limit, the effects obtained from using the crosslinking agent (F) are more significantly achieved. By having the crosslinking agent (F) at a level below the aforementioned upper limit, the aforementioned storage elastic modulus E’(90) and the aforementioned storage elastic modulus E’(70) can be reduced more easily.

The [energy-curing resin (G)] component (III) and the protective film forming film may also contain energy-curing resin (G). By containing energy-curing resin (G), the protective film forming film can change its properties by irradiation with energy rays.

Line-curing resin (G) is a line-curing compound, or can be considered as an oligomer or polymer (polymer) synthesized from a line-curing compound. Examples of such line-curing compounds include compounds having at least one polymerizable double bond within the molecule, preferably acrylate compounds having a (meth)acrylic group.

Examples of the aforementioned acrylate compounds include, for instance, trimethylolpropane tri(meth)acrylate, tetramethylmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate, which contain chain aliphatic compounds. Methacrylates with a cyclic aliphatic backbone; methacrylates containing a cyclic aliphatic backbone, such as dicyclopentyl methacrylate; polyalkylene glycol (methacrylates) such as polyethylene glycol dimethacrylate; oligopolyester (methacrylates); (meth)acrylate aminocarbamate oligomers; epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the aforementioned polyalkylene glycol (meth)acrylates; isoconic acid oligomers, etc.

The weight-average molecular weight of the aforementioned energy line hardening compound is preferably 100 to 30,000, and more preferably 300 to 10,000.

The aforementioned energy line hardening compound used to synthesize the aforementioned oligomers or polymers may be one or more. In the case of two or more, the combination and ratio of these energy line hardening compounds may be arbitrarily selected.

The energy line curing resin (G) contained in component (III) and the protective film forming film may be one or more types. In the case of two or more types, the combination and ratio of these energy line curing resins (G) may be arbitrarily selected.

When using energy line curing resin (G), the content of energy line curing resin (G) in composition (III) relative to the total mass of composition (III) is preferably 1% to 30% by mass, more preferably 5% to 25% by mass, and even more preferably 10% to 20% by mass.

When the [photopolymerization initiator (H)] component (III) and the protective film forming film contain energy line curing resin (G), in order to carry out the polymerization reaction of energy line curing resin (G) efficiently, the photopolymerization initiator (H) may also be included.

Examples of photopolymerization initiators (H) in composition (III) include: benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoate, benzoin dimethyl ketone, and other benzoin compounds; acetophenone compounds such as 2-hydroxy-2-methyl-1-phenylpropane-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropenyl)benzyl)phenyl)-2-methylpropane-1-one, 2-(dimethylamino)-1-(4-morpholinylphenyl)-2-benzyl-1-butanone; bis(2 Acrylphosphine oxide compounds such as 4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; sulfide compounds such as benzylphenyl sulfide and tetramethylthiuram monosulfide; α-ketone compounds such as 1-hydroxycyclohexylphenyl ketone; azo compounds such as azobisisobutyronitrile; titanium eccentricate compounds such as titanium eccentricate; thiotonone compounds such as thiotonone; peroxide compounds; diacetyl compounds such as diacetyl; benzohexyl; dibenzohexyl; benzophenone; 2,4-diethylthiotonone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone; quinone compounds such as 1-chloroanthraquinone and 2-chloroanthraquinone. Furthermore, photosensitizers such as levulinamide can also be used as photopolymerization initiators (H).

The photopolymerization initiator (H) contained in the composition (III) and the protective film forming film may be one or more. In the case of two or more, the combination and ratio of these photopolymerization initiators (H) may be arbitrarily selected.

When using a photopolymerization initiator (H), in composition (III), the content of the photopolymerization initiator (H) is preferably 0.1 to 20 parts by mass relative to 100 parts by mass of the energy line curing resin (G), more preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass.

[Colorant (I)] Composition (III) and the protective film forming film preferably contain colorant (I). By containing colorant (I), the light transmittance of the protective film forming film and the protective film can be easily adjusted.

As coloring agents (I), examples include known coloring agents such as inorganic pigments, organic pigments, and organic dyes.

Examples of organic pigments and dyes mentioned above include: amine-based pigments, anthocyanin-based pigments, quinone-based pigments, squalene-based pigments, azuron-based pigments, polymethyl pigments, naphthoquinone-based pigments, pyranone-based pigments, phthalocyanine-based pigments, naphthylphthalocyanine-based pigments, naphthyllactone-based pigments, azo-based pigments, condensed azo-based pigments, indigo-based pigments, pyrenone-based pigments, perylene-based pigments, and dioxazine-based pigments. Pigments include quinacridone pigments, isoindolineone pigments, quinolineone pigments, pyrrole pigments, indigo pigments, metal complex pigments (metal chromate dyes), dithiol metal complex pigments, indolephenol pigments, triallylmethane pigments, anthraquinone pigments, naphthol pigments, methylimine pigments, benzimidazole pigments, pinantrone pigments, and threne pigments, etc.

Examples of inorganic pigments mentioned above include: carbon black, cobalt-based pigments, iron-based pigments, chromium-based pigments, titanium-based pigments, vanadium-based pigments, zirconium-based pigments, molybdenum-based pigments, ruthenium-based pigments, platinum-based pigments, ITO (Indium Tin Oxide) pigments, and ATO (Antimony Tin Oxide) pigments.

The colorant (I) contained in the composition (III) and the protective film forming film may be only one type or two or more types. In the case of two or more types, the combination and ratio of these colorants (I) can be arbitrarily selected.

When using a colorant (I), the amount of colorant (I) in the protective film forming film can be adjusted appropriately according to the purpose. For example, by adjusting the amount of colorant (I) in the protective film forming film, the light transmittance of the protective film forming film can be adjusted, thereby adjusting the print legibility when laser printing is performed on the protective film forming film or the protective film. Moreover, by adjusting the amount of colorant (I) in the protective film forming film, the creativity of the protective film can also be improved, or the grinding marks on the inner surface of the wafer can be made less visible. Taking these aspects into consideration, the ratio of colorant (I) content in the protective film to the total mass of the protective film is preferably 0.1% to 10% by mass, more preferably 0.1% to 7.5% by mass, and even more preferably 0.1% to 5% by mass. By setting the aforementioned ratio above the aforementioned lower limit, the effects obtained by using colorant (I) are more significantly achieved. For example, when the protective film is peeled off from the adherend, it is easy to visually confirm whether any residue of the protective film remains on the adherend. By setting the aforementioned ratio below the aforementioned upper limit, the excessive use of colorant (I) is suppressed.

[General Additive (J)] The composition (III) and the protective film may also contain a general additive (J) to the extent that it does not impair the efficacy of the invention. The general additive (J) may be known and may be selected arbitrarily according to the purpose without particular limitation. Preferred additives include, for example: plasticizers, antistatic agents, antioxidants, getters, ultraviolet absorbers, etc.

The component (III) and the protective film forming film may contain only one or more general additives (J). In the case of two or more, the combination and ratio of these general additives (J) can be arbitrarily selected. There is no particular limitation on the content of the general additives (J) in the component (III) and the protective film forming film, as long as they are appropriately selected according to the purpose.

[Soluble] Composition (III) preferably contains a solvent. Composition (III) containing a solvent has better workability. In this specification, the term "solvent" is defined as not only as a substance that dissolves the object component, but also as a dispersion medium that disperses the object component.

The aforementioned solvents are not particularly limited, but preferred examples include: hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropane-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds containing amide bonds) such as dimethylformamide and N-methylpyrrolidone. Component (III) may contain only one type of solvent or two or more types. In the case of two or more types, the combination and ratio of these solvents can be arbitrarily selected.

Among the solvents contained in composition (III), those that are better solvents, for example, that can mix the components contained in composition (III) more evenly, include methyl ethyl ketone, toluene, ethyl acetate, etc.

There is no particular limitation on the amount of solvent in component (III). For example, it can be appropriately selected according to the type of components other than the solvent.

[Manufacturing Method of Component (III) for Protective Film Formation] Component (III) is obtained by blending the various components constituting the component. There is no particular limitation on the order in which the components are added, and two or more components may be added simultaneously. There is no particular limitation on the method of mixing the components during blending, as long as a suitable method is selected from the following known methods: mixing by rotating a stir bar or stirring blade; mixing using a mixer; mixing by applying ultrasound. There is no particular limitation on the temperature and time during the addition and mixing of the components, as long as the components do not deteriorate, and they may be adjusted appropriately. The preferred temperature is 15°C to 30°C.

◎Example of protective film formation Figure 1 is a schematic cross-sectional view showing an example of a protective film formation according to the present embodiment. Furthermore, in the following description, some parts that are important are sometimes enlarged for ease of understanding of the features of the present invention, and the size ratios of each component may not be the same as the actual dimensions.

The protective film forming film 13 shown here has a first peeling film 151 on one side (sometimes referred to as the "first side" in this specification) 13a, and a second peeling film 152 on the other side (sometimes referred to as the "second side" in this specification) 13b, which is opposite to the first side 13a. This protective film forming film 13 is suitable for storage, for example, in a roller shape.

When measuring the storage elastic modulus E’ of the aforementioned test piece made by forming the protective film 13, the storage elastic modulus E’(90) of the aforementioned test piece at 90°C is less than 5 MPa.

The protective film forming film 13 can be formed using the above-mentioned protective film forming composition.

Both the first peeling membrane 151 and the second peeling membrane 152 can be known peeling membranes. The first peeling membrane 151 and the second peeling membrane 152 can be the same as each other, or they can be different from each other, for example, they can be different because the peeling force required when the self-protective membrane forming membrane 13 is different.

The protective film forming film 13 shown in Figure 1 is formed by removing either the first release film 151 or the second release film 152, and the resulting exposed surface becomes the attachment surface for any part of the workpiece (not shown). Alternatively, when using a support sheet or cutting sheet as described later, the remaining one of the first release film 151 and the second release film 152 is removed, and the exposed surface of the resulting protective film forming film 13 becomes the attachment surface for the aforementioned support sheet or cutting sheet.

Figure 1 shows an example where the peeling membrane is disposed on both sides (first side 13a, second side 13b) of the protective film forming membrane 13. However, the peeling membrane may also be disposed on only one side of the protective film forming membrane 13, that is, only on the first side 13a or only on the second side 13b.

The protective film forming membrane of this embodiment has the following forms. "1" A protective film forming membrane with thermosetting properties; when a 4 mm wide sample of the aforementioned protective film forming membrane is held at two locations with a 20 mm interval, and the sample is heated from -50 °C to 150 °C in a stretching mode at a frequency of 11 Hz, a heating rate of 3 °C/min, and a constant heating rate, the storage elastic modulus E' of the aforementioned sample is measured. Before 90 °C, the storage elastic modulus E' (90) of the aforementioned sample is any one of 5 MPa or less, 3 MPa or less, 2 MPa or less, 0.4 MPa or less, and 0.2 MPa or less.

"2" As described in "1", the protective film forming film is formed by taking a 4 mm wide test piece of the aforementioned protective film forming film and holding it at two locations with a 20 mm interval. The test piece is heated from -50°C to 150°C in a stretching mode at a frequency of 11 Hz, a heating rate of 3°C/min, and a constant heating rate. When the tanδ of the test piece is measured, the tanδ (90) of the test piece before 90°C is any one of 0.20 or more, 0.24 or more, and 0.34 or more.

"3" As described in "1" or "2", in which a 5 mm wide specimen of the heat-cured material of the aforementioned protective film is held at two locations with a 20 mm interval, and the specimen is heated from -60°C to 300°C in a stretching mode at a frequency of 11 Hz, a heating rate of 3°C/min and a constant heating rate, while the storage elastic modulus E' of the aforementioned specimen is measured, the storage elastic modulus E' (23) of the aforementioned specimen before 23°C is any one of 100 MPa or more, 200 MPa or more, and 300 MPa or more.

"4" The protective film formed as described in any of "1" to "3" contains a polymer component (A) comprising acrylic resin; wherein the glass transition temperature of the aforementioned acrylic resin is not 10°C, and is any one of -80°C or higher to less than 10°C, -70°C or higher to less than 5°C, -60°C or higher to less than 0°C, and -60°C or higher to less than -5°C.

"5" The protective film forming film as described in any of "1" to "4" contains filler (D); the content of the filler (D) relative to the total mass of the aforementioned protective film forming film is any one of less than 50% by mass, more than 30% by mass and less than 70% by mass, more than 35% by mass and less than 70% by mass, more than 35% by mass and less than 65% by mass, more than 35% by mass and less than 59% by mass, and more than 35% by mass and less than 50% by mass.

"6" is a protective film forming film as described in any of "1" to "5", wherein the polymer component (A) is present; the content of the polymer component (A) relative to the total mass of the aforementioned protective film forming film is any one of 10% to 85% by mass, 15% to 70% by mass, 15% to 45% by mass, 15% to 35% by mass, 20% to 70% by mass, and 25% to 70% by mass.

"7" is a protective film formed as described in any of "1" to "6", which contains a polymer component (A) and a thermosetting component (B); the content of the thermosetting component (B) is any one of 10 to 100 parts by mass, 20 to 70 parts by mass, 25 to 55 parts by mass, and 30 to 45 parts by mass, relative to the total content of the polymer component (A) and the thermosetting component (B) of 100 parts by mass.

"8" As described in any of "1" to "7", wherein when a 4 mm wide sample of the aforementioned protective film is held at two locations with a 20 mm interval, and the sample is heated from -50°C to 150°C in a stretching mode at a frequency of 11 Hz, a heating rate of 3°C/min, and a constant heating rate, the storage elastic modulus E' of the sample is measured, and the storage elastic modulus E'(90) of the sample before 90°C is less than the storage elastic modulus E'(70) of the sample before 70°C. "9" As described in "8", wherein the aforementioned storage elastic modulus E'(70) is any one of 8 MPa or less, 3.5 MPa or less, 3 MPa or less, and 2 MPa or less.

The protective film forming film of this embodiment, when used in conjunction with the support sheet described later, can constitute a composite sheet for forming a protective film that can simultaneously perform the formation of a protective film and the processing (e.g., cutting) of a workpiece. This composite sheet for forming a protective film will be described below.

◇ Composite Sheet for Protective Film Formation One embodiment of the present invention comprises a composite sheet for protective film formation, having a support sheet and a protective film forming film disposed on one side of the support sheet, wherein the protective film forming film is the protective film forming film of one embodiment of the present invention. The composite sheet for protective film formation of this embodiment can be attached to a target area of a workpiece (e.g., the inner surface of a wafer) by means of the protective film forming film in the composite sheet.

In this specification, even after the protective film has hardened, as long as the laminated structure of the thermocured material of the support sheet and the protective film is maintained, the laminated structure is referred to as a "composite sheet for forming a protective film".

The following provides a detailed description of each layer of the composite sheet that constitutes the aforementioned protective film.

◎Supporting Sheet The aforementioned supporting sheet may be composed of one layer (single layer) or multiple layers (two or more layers). When the supporting sheet is composed of multiple layers, the constituent materials and thicknesses of these multiple layers may be the same or different from each other. There are no particular limitations on the combination of these multiple layers as long as it does not impair the function of the invention.

Support sheets can be either transparent or opaque, and can also be colored depending on the purpose. When the protective film forming film has energy line hardening properties, the support sheet is preferably designed to allow energy lines to pass through.

Examples of support sheets include: a support sheet having a substrate and an adhesive layer disposed on one side of the substrate; and a support sheet consisting only of a substrate. When the support sheet has an adhesive layer, the adhesive layer is disposed between the substrate and the protective film forming film in the composite sheet for forming the protective film.

When using a support sheet having a substrate and an adhesive layer, the adhesion and peelability between the support sheet and the protective film forming film can be easily adjusted in the protective film forming composite sheet. When using a support sheet consisting only of a substrate, the protective film forming composite sheet can be manufactured at low cost.

Hereinafter, with reference to the drawings, examples of composite sheets for forming protective films in this embodiment will be explained according to the types of such support sheets.

◎An Example of a Composite Sheet for Forming a Protective Film Figure 2 is a schematic cross-sectional view showing an example of a composite sheet for forming a protective film according to this embodiment. Furthermore, in the figures following Figure 2, for the same constituent elements as shown in the previously described figures, the same symbols are used as in the previously described figures, and detailed explanations are omitted.

The protective film forming composite sheet 101 shown here comprises a support sheet 10 and a protective film forming film 13 disposed on one side (sometimes referred to as the "first side") 10a of the support sheet 10. The support sheet 10 comprises a substrate 11 and an adhesive layer 12 disposed on one side (first side) 11a of the substrate 11. In the protective film forming composite sheet 101, the adhesive layer 12 is disposed between the substrate 11 and the protective film forming film 13. That is, the protective film forming composite sheet 101 is formed by sequentially laminating the substrate 11, the adhesive layer 12 and the protective film forming film 13 in their thickness directions. The first surface 10a of the support sheet 10 is the same as the side of the adhesive layer 12 opposite to the side of the substrate 11 (sometimes referred to as the "first surface" in this specification) 12a.

The protective film forming composite sheet 101 further has a jig adhesive layer 16 and a peeling film 15 on the protective film forming film 13. In the protective film forming composite sheet 101, the protective film forming film 13 is deposited on the entire or substantially entire first surface 12a of the adhesive layer 12, and the jig adhesive layer 16 is deposited on a portion of the side of the protective film forming film 13 opposite to the side of the adhesive layer 12 (sometimes referred to as the "first surface" in this specification), that is, in the area near the periphery. Furthermore, a peeling film 15 is deposited on the area of the first surface 13a of the protective film forming film 13 where the fixture adhesive layer 16 is not deposited, and on the surface of the fixture adhesive layer 16 opposite to the protective film forming film 13 (sometimes referred to as the "first surface" in this specification) 16a. A support sheet 10 is provided on the surface of the protective film forming film 13 opposite to the first surface 13a (sometimes referred to as the "second surface" in this specification) 13b.

Not limited to the protective film forming composite sheet 101, in the protective film forming composite sheet of this embodiment, the peeling membrane (e.g., the peeling membrane 15 shown in FIG2) can be of any configuration. The protective film forming composite sheet of this embodiment may or may not have a peeling membrane.

The adhesive layer 16 for the fixture is used to fix the protective film forming composite sheet 101 to a fixture such as an annular frame. The adhesive layer 16 for the fixture may have a single-layer structure containing adhesive or adhesive components, or it may have a multi-layer structure, which has a sheet that serves as the core material and layers containing adhesive or adhesive components disposed on both sides of the aforementioned sheet.

The protective film forming composite sheet 101 is used to attach the target part of the workpiece to the first surface 13a of the protective film forming film 13 with the peeling film 15 removed, and then attach the first surface 16a of the adhesive layer 16 of the fixture to the fixture such as the ring frame.

As described above, in the step of manufacturing the aforementioned workpiece with a protective film or the aforementioned processed workpiece with a protective film using the protective film forming composite sheet 101 with the protective film forming film 13, even if there are scratches on the surface of the thermosetting protective film forming film, the scratches on the surface of the protective film after the protective film forming film 13 is thermosetting can still become inconspicuous.

Figure 3 is a schematic cross-sectional view showing another example of the protective film forming composite sheet of this embodiment. The protective film forming composite sheet 102 shown here is the same as the protective film forming composite sheet 101 shown in Figure 2, except that the shape and size of the protective film forming film are different, and the adhesive layer of the fixture is deposited on the first side of the adhesive layer rather than the first side of the protective film forming film.

More specifically, in the protective film forming composite sheet 102, the protective film forming film 23 is deposited on a portion of the first surface 12a of the adhesive layer 12, that is, the central area of the adhesive layer 12 in the width direction (left-right direction in FIG. 3). Furthermore, in the area of the first surface 12a of the adhesive layer 12 where the protective film forming film 23 is not deposited, a jig adhesive layer 16 is deposited in such a way that the protective film forming film 23 is non-contactly surrounded from the outside of the width direction. Additionally, a release film 15 is laminated on the side of the protective film forming film 23 opposite to the adhesive layer 12 (sometimes referred to as the "first side" in this specification) 23a and the first side 16a of the fixture adhesive layer 16. A support sheet 10 is provided on the side of the protective film forming film 23 opposite to the first side 23a (sometimes referred to as the "second side" in this specification) 23b.

Figure 4 is a schematic cross-sectional view showing another example of the protective film forming composite sheet of this embodiment. The protective film forming composite sheet 103 shown here is the same as the protective film forming composite sheet 102 shown in Figure 3, except that it does not have the adhesive layer 16 for the jig.

Figure 5 is a schematic cross-sectional view showing another example of the protective film forming composite sheet of this embodiment. The protective film forming composite sheet 104 shown here is the same as the protective film forming composite sheet 101 shown in Figure 2, except that it is constructed with a support sheet 20 instead of a support sheet 10.

The support sheet 20 is composed solely of the substrate 11. That is, the protective film forming composite sheet 104 is formed by laminating the substrate 11 and the protective film forming film 13 in their thickness directions. The side surface (one side) 20a of the protective film forming film 13 of the support sheet 20 is the same as the first side surface 11a of the substrate 11.

The protective film forming composite sheet of this embodiment is not limited to that shown in Figures 1 to 5. Within the scope of not impairing the effectiveness of the invention, one part shown in Figures 1 to 5 may be modified or deleted, or other components may be added to the protective film forming composite sheet described so far.

Then, the layers that make up the support sheet are explained in more detail.

○ Substrate The aforementioned substrate is in sheet or film form, and various resins can be listed as constituent materials of the substrate. Examples of such resins include: polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resins; ethylene-based copolymers (polymers obtained using ethylene as a monomer) such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid copolymer, and ethylene-norbornene copolymer; vinyl chloride-based resins (resins obtained using vinyl chloride as a monomer) such as polyvinyl chloride and vinyl chloride copolymers; polystyrene... Ethylene; polycyclic aromatic hydrocarbons; polyethylene terephthalate, polyethylene naphthalate, polyethylene butylene terephthalate, polyethylene isophthalate, polyethylene 2,6-naphthalate, and other fully aromatic polyesters whose constituent units have aromatic cyclic groups; copolymers of two or more of the aforementioned polyesters; poly(meth)acrylates; polyurethane; polyurethane acrylates; polyimide; polyamide; polycarbonate; fluororesins; polyacetal; modified polyphenylene ether; polyphenylene sulfide; polyetherketone; etc. Furthermore, polymer alloys, such as mixtures of the aforementioned polyesters and other resins, can also be listed as polymer alloys. Preferably, in polymer alloys of the aforementioned polyesters and other resins, the amount of resins other than polyesters is relatively small. Furthermore, examples of the aforementioned resins include, for instance, crosslinked resins formed by crosslinking one or more of the resins described so far; and modified resins using one or more ionic polymers of the resins described so far. In terms of excellent heat resistance, polypropylene or polybutylene terephthalate is preferred among the aforementioned resins.

The resin constituting the substrate may be one type or two or more types. In the case of two or more types, the combination and ratio of these resins can be arbitrarily selected.

The substrate can be composed of one layer (single layer) or multiple layers (two or more layers). When it is composed of multiple layers, these multiple layers can be the same or different from each other, and there is no particular limitation on the combination of these multiple layers.

The thickness of the substrate is preferably 50 μm to 300 μm, and more preferably 60 μm to 100 μm. By using a substrate thickness within this range, the flexibility of the composite sheet used for forming the protective film and its suitability for wafer bonding are further improved. Here, "substrate thickness" refers to the overall thickness of the substrate, such as the thickness of a multi-layer substrate, which refers to the total thickness of all the layers that make up the substrate.

In addition to the aforementioned main constituent materials such as resins, the substrate may also contain various known additives such as fillers, colorants, antioxidants, organic lubricants, catalysts, and plasticizers.

The substrate can be either transparent or opaque, and can be colored or coated with other layers depending on the purpose. When the protective film has energy line hardening properties, the substrate is preferably designed to allow energy lines to pass through.

The substrate may also undergo surface treatments to adjust its adhesion to layers disposed on it (e.g., adhesive layers, protective film forming films, or other aforementioned layers), such as: roughening treatments using sandblasting, solvent treatment, etc.; oxidation treatments such as corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone-ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment, etc.; oleophilic treatment; hydrophilic treatment, etc. Furthermore, the substrate may also undergo a surface primer treatment.

The substrate can also have adhesiveness on at least one side by containing a specific range of components (such as resin).

The substrate can be manufactured by known methods. For example, a resin-containing substrate can be manufactured by molding a resin composition containing the aforementioned resin.

○ Adhesive Layer The aforementioned adhesive layer is in sheet or film form and contains an adhesive. Examples of such adhesives include: acrylic resins, carbamate resins, rubber-based resins, polysiloxane resins, epoxy resins, polyvinyl ether, polycarbonate, ester-based resins, and other adhesive resins.

The adhesive layer can consist of a single layer or multiple layers. When it consists of multiple layers, these multiple layers can be the same or different from each other, and there are no particular restrictions on the combination of these multiple layers.

The thickness of the adhesive layer is not particularly limited, but it is preferably 1 μm to 100 μm, more preferably 1 μm to 60 μm, and even more preferably 1 μm to 30 μm. Here, the term "thickness of the adhesive layer" refers to the overall thickness of the adhesive layer, such as the thickness of an adhesive layer composed of multiple layers, which means the total thickness of all the layers that make up the adhesive layer.

The adhesive layer can be either transparent or opaque, and can also be colored depending on the purpose. When the protective film has energy line hardening properties, the adhesive layer is preferably designed to allow the energy lines to pass through.

The adhesive layer can be either line-cured or non-line-cured. A line-cured adhesive layer allows for adjustment of its properties before and after curing. For example, by curing the line-cured adhesive layer before picking up the protective film wafer (described later), the protective film wafer can be picked up more easily.

In this specification, even after the energy line curing adhesive layer has been energy line cured, as long as the laminated structure of the substrate and the cured energy line curing adhesive layer is maintained, the laminated structure is referred to as a "support sheet".

An adhesive layer can be formed using an adhesive composition containing an adhesive. For example, an adhesive composition is applied to the object surface to which the adhesive layer is to be formed, and then dried as needed, thereby forming an adhesive layer on the target area. The ratio of the non-vaporizable components in the adhesive composition to each other at room temperature is usually the same as the ratio of the aforementioned components to each other in the adhesive layer.

In the adhesive layer, the percentage of the total content of one or more of the ingredients described below in the adhesive layer does not exceed 100% by mass relative to the total mass of the adhesive layer. Similarly, in the adhesive composition, the percentage of the total content of one or more of the ingredients described below in the adhesive composition does not exceed 100% by mass relative to the total mass of the adhesive composition.

The application and drying of the adhesive composition can be carried out, for example, by the same method as the application and drying of the composition for forming the protective film described above.

When the adhesive layer is energy-line hardening, the energy-line hardening adhesive composition may include, for example, the following adhesive compositions: adhesive composition (I-1), containing a non-energy-line hardening adhesive resin (I-1a) (hereinafter sometimes simply referred to as "adhesive resin (I-1a)") and an energy-line hardening compound; adhesive composition (I-2), containing an energy-line hardening adhesive resin (I-2a) (hereinafter sometimes simply referred to as "adhesive resin (I-2a)") with unsaturated groups introduced into the side chains of the non-energy-line hardening adhesive resin (I-1a); and adhesive composition (I-3), containing the aforementioned adhesive resin (I-2a) and an energy-line hardening compound.

When the adhesive layer is non-energy-line curing, examples of non-energy-line curing adhesive compositions include adhesive compositions (I-4) containing the aforementioned non-energy-line curing adhesive resin (I-1a).

[Non-energy-line hardening adhesive resin (I-1a)] The aforementioned adhesive resin (I-1a) is preferably an acrylic resin.

Examples of the aforementioned acrylic resins include acrylic polymers having at least one constituent unit derived from an alkyl methacrylate. Examples of the aforementioned alkyl methacrylates include alkyl methacrylates in which the alkyl group forming the alkyl ester has 1 to 20 carbon atoms, preferably in a linear or branched form.

The aforementioned acrylic polymer is preferably composed of, in addition to the constituent units derived from (meth)acrylate alkyl esters, constituent units derived from functionalized monomers. Examples of such functionalized monomers include monomers that become crosslinking starting points through the reaction of the aforementioned functional groups with the crosslinking agent described later.

Examples of functionalized monomers include hydroxyl monomers, carboxyl monomers, amine monomers, and epoxy monomers.

The aforementioned acrylic polymers may also have constituent units derived from (meth)acrylate alkyl esters, and constituent units derived from functionalized monomers, as well as constituent units derived from other monomers. There are no particular limitations on the aforementioned other monomers, as long as they can copolymerize with (meth)acrylate alkyl esters, etc. Examples of such other monomers include: styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide, etc.

In the aforementioned adhesive composition (I-1), adhesive composition (I-2), adhesive composition (I-3) and adhesive composition (I-4) (hereinafter referred to as "adhesive composition (I-1) to adhesive composition (I-4)"), the aforementioned acrylic polymer and other acrylic resins may have only one type of constituent unit or more than two types. In the case of more than two types, the combination and ratio of these constituent units can be arbitrarily selected.

In the aforementioned acrylic polymer, the ratio of the amount of the constituent unit containing the functional group to the total amount of the constituent unit is preferably 1% to 35% by mass.

The adhesive resin (I-1a) contained in the adhesive composition (I-1) or adhesive composition (I-4) may be only one type or two or more types. In the case of two or more types, the combination and ratio of these adhesive resins (I-1a) may be arbitrarily selected.

In the adhesive layer formed by adhesive composition (I-1) or adhesive composition (I-4), the content of adhesive resin (I-1a) is preferably 5% to 99% by mass relative to the total mass of the aforementioned adhesive layer.

[Energy Line Hardening Adhesive Resin (I-2a)] The aforementioned adhesive resin (I-2a) is obtained, for example, by reacting an unsaturated compound containing an energy line polymerizable unsaturated group with the functional groups in the adhesive resin (I-1a).

The aforementioned unsaturated group-containing compounds are compounds that, in addition to the aforementioned energy-line polymerizable unsaturated groups, further possess a group capable of bonding with the adhesive resin (I-1a) through reaction with the functional groups in the adhesive resin (I-1a). Examples of the aforementioned energy-line polymerizable unsaturated groups include (meth)acrylyl, ethenyl, and allyl (2-propenyl), with (meth)acrylyl being preferred. Examples of groups capable of bonding with the functional groups in the adhesive resin (I-1a) include isocyanate groups and glycidyl groups capable of bonding with hydroxyl or amino groups, and hydroxyl and amino groups capable of bonding with carboxyl or epoxy groups.

Examples of compounds containing unsaturated groups include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and (meth)acrylate glycidyl ester.

The adhesive resin (I-2a) contained in the adhesive composition (I-2) or adhesive composition (I-3) may be only one type or two or more types. In the case of two or more types, the combination and ratio of these adhesive resins (I-2a) may be arbitrarily selected.

In the adhesive layer formed by adhesive composition (I-2) or adhesive composition (I-3), the content of adhesive resin (I-2a) is preferably 5% to 99% by mass relative to the total mass of the aforementioned adhesive layer.

[Energy-line hardening compounds] The energy-line hardening compounds contained in the aforementioned adhesive composition (I-1) or adhesive composition (I-3) can be listed as: monomers or oligomers having energy-line polymerizable unsaturated groups and capable of being hardened by energy-line irradiation.

Examples of monomers in energy line curing compounds include: trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol (meth)acrylate, and other poly(meth)acrylates; (meth)acrylate aminocarbamates; polyester (meth)acrylates; polyether (meth)acrylates; epoxy (meth)acrylates, etc. Examples of oligomers in energy line curing compounds include oligomers that are polymers of the monomers exemplified above.

The adhesive composition (I-1) or adhesive composition (I-3) may contain only one or more of the aforementioned energy line hardening compounds. In the case of two or more, the combination and ratio of these energy line hardening compounds may be arbitrarily selected.

In the adhesive layer formed by adhesive composition (I-1) or adhesive composition (I-3), the content of the aforementioned energy line hardening compound is preferably 1% to 95% by mass relative to the total mass of the aforementioned adhesive layer.

[Crosslinking Agent] When using the aforementioned acrylic polymer as an adhesive resin (I-1a) that has, in addition to the constituent units derived from (meth)acrylate alkyl esters, also a constituent unit derived from a functional group, the adhesive composition (I-1) or adhesive composition (I-4) preferably contains a crosslinking agent. Moreover, for example, when using the aforementioned acrylic polymer as an adhesive resin (I-2a) that has the same constituent units derived from functional groups as in adhesive resin (I-1a), the adhesive composition (I-2) or adhesive composition (I-3) may also contain a crosslinking agent.

The aforementioned crosslinking agent, for example, reacts with the aforementioned functional groups to crosslink adhesive resins (I-1a) with each other or adhesive resins (I-2a) with each other. Examples of crosslinking agents include: toluene diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, and adducts of these diisocyanates (crosslinking agents with isocyanate groups); epoxy crosslinking agents such as ethylene glycol glycidyl ether (crosslinking agents with glycidyl groups); aziridine crosslinking agents such as hexa[1-(2-methyl)aziridinyl]triphosphatrazine (crosslinking agents with aziridine groups); metal chelating crosslinking agents such as aluminum chelates (crosslinking agents with metal chelating structures); and isocyanurate crosslinking agents (crosslinking agents with an isocyanuric acid skeleton).

The crosslinking agent contained in the adhesive composition (I-1) to the adhesive composition (I-4) may be only one type or two or more types. In the case of two or more types, the combination and ratio of these crosslinking agents can be arbitrarily selected.

In the aforementioned adhesive composition (I-1) or adhesive composition (I-4), the content of crosslinking agent is preferably 0.01 to 50 parts by weight relative to 100 parts by weight of adhesive resin (I-1a). In the aforementioned adhesive composition (I-2) or adhesive composition (I-3), the content of crosslinking agent is preferably 0.01 to 50 parts by weight relative to 100 parts by weight of adhesive resin (I-2a).

[Photopolymerization Initiator] Adhesive components (I-1), (I-2), and (I-3) (hereinafter referred to as "Adhesive Components (I-1) to Adhesive Components (I-3)") may further contain a photopolymerization initiator. Adhesive components (I-1) to (I-3) containing a photopolymerization initiator undergo sufficient hardening reaction even when irradiated with relatively low-energy rays such as ultraviolet light.

As a photopolymerization initiator, for example, other photopolymerization initiators similar to the aforementioned photopolymerization initiator (H) can be listed.

The photopolymerization initiator contained in the adhesive composition (I-1) to the adhesive composition (I-3) may be only one type or two or more types. In the case of two or more types, the combination and ratio of these photopolymerization initiators may be arbitrarily selected.

In the adhesive composition (I-1), the content of photopolymerization initiator is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the aforementioned energy line curing compound. In the adhesive composition (I-2), the content of photopolymerization initiator is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the adhesive resin (I-2a). In the adhesive composition (I-3), the content of photopolymerization initiator is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the total content of the adhesive resin (I-2a) and the aforementioned energy line curing compound.

[Other Additives] Adhesive compositions (I-1) to (I-4) may also contain other additives not equivalent to any of the above-mentioned components, to the extent that the efficacy of the invention is not impaired. Examples of such other additives include, for example, antistatic agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, colorants (pigments, dyes), sensitizers, tackifiers, reaction retarders, crosslinking promoters (catalysts), and other known additives. Furthermore, a reaction retarder is, for example, a component that inhibits unintended cross-linking reactions in the adhesive components (I-1) to (I-4) during storage due to the catalytic action of the catalyst mixed in with the adhesive components (I-1) to (I-4). Examples of reaction retarders include compounds that form chelate complexes by chelating the catalyst; more specifically, compounds having two or more carbonyl groups (-C(=O)-) in one molecule.

The adhesive composition (I-1) to adhesive composition (I-4) may contain only one or more other additives. In the case of two or more additives, the combination and ratio of these other additives may be arbitrarily selected.

There are no particular limitations on the content of other additives in adhesive compositions (I-1) to adhesive compositions (I-4), as long as they are selected appropriately according to the type of additive.

[Soluble] Adhesive components (I-1) to adhesive components (I-4) may also contain a solvent. Adhesive components (I-1) to adhesive components (I-4) improve their application suitability relative to the application surface by containing a solvent.

The aforementioned solvent is preferably an organic solvent. Examples of such organic solvents include: ketones such as methyl ethyl ketone and acetone; esters (carboxylic acid esters) such as ethyl acetate; ethers such as tetrahydrofuran and dioxane; aliphatic hydrocarbons such as cyclohexane and n-hexane; aromatic hydrocarbons such as toluene and xylene; and alcohols such as 1-propanol and 2-propanol.

The adhesive composition (I-1) to adhesive composition (I-4) may contain only one type of solvent or two or more types of solvent. In the case of two or more types of solvent, the combination and ratio of these solvents may be arbitrarily selected.

There is no particular limitation on the content of solvent in adhesive components (I-1) to adhesive components (I-4), as long as it is adjusted appropriately.

○ Method for manufacturing adhesive composition Adhesive composition, except for the different types of formulations, can be manufactured by the same method as the protective film forming composition described above.

◇ Manufacturing method of composite sheet for forming protective film The aforementioned composite sheet for forming protective film can be manufactured by laminating the above layers in a corresponding positional relationship, and adjusting the shape of some or all of the layers as needed. The formation method of each layer is as described above.

For example, when an adhesive layer is deposited on a substrate during the manufacture of a support sheet, the adhesive composition described above can simply be applied to the substrate and dried as needed. Furthermore, an adhesive layer can also be deposited on the substrate by applying an adhesive composition to a release film and drying it as needed, thereby pre-forming an adhesive layer on the release film, and then adhering the exposed surface of the adhesive layer to a surface of the substrate. In this case, the adhesive composition is preferably applied to the release-treated surface of the release film. Moreover, in this situation, the release film can be removed at any time during the manufacturing or use of the composite sheet for forming the protective film. So far, we have taken the case of an adhesive layer being laminated on a substrate as an example, but the above method can also be applied to cases where other layers besides an adhesive layer are laminated on a substrate.

On the other hand, when a protective film is deposited on top of an adhesive layer already deposited on a substrate, a protective film forming component can be applied to the adhesive layer to directly form the protective film forming film. Layers other than the protective film forming film can also be formed using the same component used to form those layers, deposited on the adhesive layer using the same method. Thus, when a new layer (hereinafter referred to as "second layer") is formed on any layer already deposited on the substrate (hereinafter sometimes referred to as "first layer") to form a laminated structure of two consecutive layers (in other words, a laminated structure of the first layer and the second layer), the method of applying the composition for forming the second layer to the first layer and drying it as needed can be applied. However, the second layer is preferably pre-formed on the release film using the composition for forming the second layer, and the exposed surface of the already formed second layer, which is opposite to the side in contact with the release film, is adhered to the exposed surface of the first layer, thereby forming a laminated structure of two consecutive layers. In this case, the aforementioned composition is preferably applied to the peeling treatment surface of the peeling membrane. The peeling membrane can be removed as needed after the lamination structure is formed. Here, the case of forming a protective film on the adhesive layer is taken as an example, but in cases such as forming a layer (film) other than the protective film on the adhesive layer, the lamination structure can be arbitrarily chosen.

In this way, all layers other than the substrate constituting the composite sheet for forming the protective film can be deposited by pre-forming on the release film and attaching it to the surface of the target layer. Therefore, the composite sheet for forming the protective film can be manufactured by appropriately selecting the layers using this step as needed.

Furthermore, protective film forming composite sheets are typically stored with a release film adhered to the surface of the outermost layer (e.g., the protective film forming film) opposite to the support sheet. Therefore, a protective film forming component or other component used to form the outermost layer is applied to the release film (preferably the peeling treatment surface), and dried as needed, thereby pre-forming the outermost layer on the release film. The remaining layers are then deposited on the exposed surface of this layer opposite to the side in contact with the release film. By maintaining the adhered state without removing the release film, a protective film forming composite sheet with a release film can be obtained.

◇ Method for manufacturing a workpiece with a protective film (method of using a protective film forming film and a composite sheet for forming a protective film) The aforementioned protective film forming film and the composite sheet for forming a protective film can be used to manufacture a workpiece with a protective film, which consists of a workpiece and a protective film disposed at any part of the aforementioned workpiece.

The method for manufacturing a workpiece with a protective film according to this embodiment includes the following steps: an attachment step, in which a protective film forming film, which does not constitute the aforementioned protective film forming composite sheet, or a protective film forming film in the aforementioned protective film forming composite sheet, is attached to a target area of the aforementioned workpiece, thereby producing a workpiece with a protective film forming film formed by having the aforementioned workpiece and the protective film forming film; and a thermosetting step, in which, after the aforementioned attachment step, the aforementioned protective film forming film is thermoset to form the aforementioned protective film, thereby producing the aforementioned workpiece with a protective film. When the workpiece is a wafer, a wafer with a protective film formed by having a wafer and a protective film disposed on the inner surface of the aforementioned wafer can be cited as an example of a workpiece with a protective film. The aforementioned method for manufacturing a wafer with a protective film includes the following steps: an attachment step, in which a protective film forming film that does not constitute the aforementioned protective film forming composite, or a protective film forming film in the aforementioned protective film forming composite, is attached to the inner surface of the aforementioned wafer to produce a workpiece having a protective film forming film, which is formed by having the aforementioned wafer and the aforementioned protective film forming film disposed on the inner surface of the aforementioned wafer; and a thermosetting step, in which, after the aforementioned attachment step, the aforementioned protective film forming film is thermoset to form the aforementioned protective film, thereby producing the aforementioned workpiece having a protective film.

[Manufacturing Method of Wafer with Protective Film (Manufacturing Method (1-1))] Hereinafter, as a manufacturing method of workpiece with protective film, the manufacturing method of wafer with protective film will be given as an example, and the explanation will be carried out with reference to the drawings.

Figure 6 is a cross-sectional view illustrating one example of a manufacturing method in which a protective film is formed in the manufacturing method of a wafer with a protective film according to the present embodiment (sometimes referred to as "manufacturing method (1-1)" in this specification). Here, the case of forming film 13 using the protective film shown in Figure 1 will be explained.

In the attachment step described in the aforementioned manufacturing method (1-1), firstly, as shown in FIG6(a), a protective film forming film 13 with the first release film 151 removed and having a second release film 152 on one side (here, the second side 13b) and the other side (here, the first side 13a) exposed is attached to the inner side 9b of the wafer 9, as shown in FIG6(c), to produce a wafer 901 with a protective film forming film.

In Figure 6(a), the arrows indicate the direction in which the protective film 13 is attached to the wafer 9. Preferably, the wafer 9 is placed on a temperature-regulating platform 8, as shown here, to preheat the wafer 9, and the protective film 13 is attached to the heated wafer 9. To attach the protective film 13 to its inner surface 9b, the wafer 9 is positioned with the surface area 9a, which has protruding electrodes 90, facing the platform 8. The circuit diagram of the wafer 9 is omitted here.

When the protective film forming film 13 is attached to the inner surface of the wafer 9, it is pressed from the side of the protective film forming film 13 opposite to the side of the wafer 9 by a pressing mechanism such as a lamination roller 161.

There are no particular limitations on the attachment conditions of the protective film forming film 13 to the wafer 9. Generally, the temperature of the protective film forming film 13 during attachment (attachment temperature) is preferably 20°C to 100°C, the attachment speed of the protective film forming film 13 is preferably 0.1 m/min to 2 m/min, and the pressure applied to the protective film forming film 13 during attachment (attachment pressure) is preferably 0.1 MPa to 0.6 MPa.

As shown in Figures 6(b) and 6(c), the second release film 152 is removed from the protective film 13 after it has been attached to the wafer 9. For example, when the second release film 152 is separated from the protective film 13 by a lamination roller 161, particulate foreign matter 17 may sometimes be mixed between the second release film 152 and the lamination roller 161. Therefore, sometimes the pressing marks 18 of the particulate foreign matter 17 will be formed on the surface 13b of the protective film 13 opposite to the wafer 9.

In the aforementioned manufacturing method (1-1), after the attachment step, the protective film forming film 13 attached to the wafer 9 is thermally cured in the aforementioned thermosetting step to form a protective film 13', as shown in FIG6(d), thereby producing a wafer 902 with a protective film.

The heating conditions for the protective film formation in the thermosetting step are not particularly limited, as long as the protective film is thermoset and forms a protective film to the extent that the protective film fully performs its function. The heating temperature for the protective film formation in the thermosetting step is preferably 100°C to 180°C, more preferably 110°C to 160°C, and even more preferably 120°C to 140°C. The heating time for the protective film formation in the thermosetting step is preferably 0.5h to 5h, more preferably 0.5h to 4h, and even more preferably 1h to 3h.

When using the previous protective film forming method, if an indentation 18 is formed on the surface 13b of the protective film forming film 13 opposite to the wafer 9, the indentation 18 will remain even after a thermosetting process, resulting in defective products. In contrast, when using the protective film forming film manufacturing method (1-1) of this embodiment, if indentations 18 or other damage are formed on the surface of the protective film forming film 13, the damage can be reduced by performing a thermosetting process, utilizing the self-repairing effect caused by heating, making the damage on the surface of the protective film 13' less noticeable.

The aforementioned manufacturing method (1-1) preferably includes a heating step after the aforementioned attachment step and before the aforementioned thermosetting step. This heating step involves heating the protective film forming film 13 without thermosetting it. Heating the protective film forming film 13 without thermosetting it reduces surface scratches on the protective film forming film 13, making the surface scratches on the protective film 13' less noticeable.

The heating conditions for forming the protective film in the heating step are not particularly limited, as long as they prevent the protective film 13 from thermally hardening and reduce the surface scratches of the protective film 13. The heating temperature for forming the protective film in the heating step is preferably 75°C to 105°C, more preferably 80°C to 100°C, and even more preferably 85°C to 95°C. The heating time for forming the protective film in the heating step is preferably 0.5h to 5h, more preferably 0.5h to 4h, and even more preferably 1h to 3h.

Using the wafer 902 with protective film obtained above, wafer 9 is diced and protective film 13' is cut, thereby producing a chip with protective film (illustration omitted).

Up to this point, as a manufacturing method (1-1), a method for manufacturing a wafer with a protective film using a protective film forming film has been explained. However, a composite wafer for forming a protective film with a protective film forming film can also be used instead of a protective film forming film to manufacture a wafer with a protective film forming film.

[Method for Manufacturing a Wafer with a Protective Film (Manufacturing Method (1-2))] Figure 7 is a cross-sectional view schematically illustrating one example of a manufacturing method in this embodiment of the method for manufacturing a wafer with a protective film, in which a protective film forming film is formed using a protective film that does not constitute a protective film forming composite, and a transport step is performed (sometimes referred to in this specification as "manufacturing method (1-2)"). Here, the case of using the protective film forming film 13 as shown in Figure 1 will be explained.

The attachment step described in manufacturing method (1-2) can be performed using the same method as the attachment step described in manufacturing method (1-1), such as a lamination roller. Using the attachment step described in manufacturing method (1-2), a wafer 901 with a protective film is fabricated as shown in FIG. 7(a). Even in FIG. 7(a), as in FIG. 6(c), sometimes indentations such as pressure marks 18 (not shown) are formed on the surface 13b of the protective film 13, which is opposite to the wafer 9.

In the aforementioned transport step, then as shown in FIG. 7(b), the exposed surface (here, the second surface 13b) of the protective film forming film 13 in the wafer 901 with the protective film forming film is brought into contact with the transport mechanism 7 used to transport the wafer 901 with the protective film forming film, thereby fixing the wafer 901 with the protective film forming film by the transport mechanism 7. The transport mechanism 7 can be any known type. For example, at the contact portion between the transport mechanism 7 and the transport object (here, the wafer 901 with the protective film forming film), a mechanism for fixing the transport object by adsorption (such as a so-called adsorption arm) can be used as the transport mechanism 7. As the aforementioned contact portion in this case, an adsorption tray can be cited as an example. However, the conveying mechanism 7 is not limited to this; it can also be fixed by means other than adsorption of the conveyed object. Furthermore, only the conveying mechanism 7 is shown here, and cross-sections are omitted.

In the aforementioned transport step, then as shown in Figure 7(c), the wafer 901 with the protective film formed, which is fixed by the transport mechanism 7, is pulled away from the platform 8. The arrows in Figure 7(c) indicate the direction in which the wafer 901 with the protective film formed is pulled away from the platform 8.

Furthermore, as shown in Figure 7(d), the wafer 901 with the protective film forming film is then directly transported in a fixed state by the transport mechanism 7. In addition, in Figure 7(d), the transport direction of the wafer 901 with the protective film forming film is indicated by arrows, but this is only one example of the transport direction, and the transport direction is not limited to this direction.

In the aforementioned transport step, then as shown in FIG7(e), the fixed state of the transport mechanism 7 is released from the wafer 901 with the protective film formed after transport to the target site, and the transport mechanism 7 is pulled away from the wafer 901 with the protective film formed. As described above, the aforementioned transport step is completed.

After the aforementioned conveying steps are completed, contact marks 19 may sometimes form at the contact point between the protective film forming film 13 (more specifically, the second surface 13b of the protective film forming film 13) in the wafer 901 with the protective film forming film and the fixing part in the conveying mechanism 7, due to contact with the conveying mechanism 7. For example, if the aforementioned fixing part is a planar suction tray with a circular shape, sometimes circular contact marks 19 are formed on the exposed surface of the protective film forming film 13.

Following the aforementioned transport step in the aforementioned manufacturing method (1-2), the protective film 13 attached to the wafer 9 is thermally cured in the aforementioned thermosetting step to form a protective film 13', as shown in FIG. 7(f), thereby producing a wafer 902 with a protective film. The thermosetting step in manufacturing method (1-2) can be performed in the same manner as the thermosetting step in manufacturing method (1-1).

When using the previous protective film forming method, if scratches such as indentation 18 and contact marks 19 are formed on the surface 13b of the protective film forming film 13 opposite to the wafer 9, these scratches will remain even after the thermosetting step, resulting in defective products. In contrast, when using the protective film forming film manufacturing method (1-2) of this embodiment, if scratches are formed on the surface of the protective film forming film 13, the scratches can be reduced by performing the thermosetting step due to the self-repairing effect caused by heating, and the scratches on the surface of the protective film 13' become less noticeable.

Preferably, the aforementioned manufacturing method (1-2) includes a heating step after the aforementioned conveying step and before the aforementioned thermosetting step, in which the protective film forming film 13 is heated without thermosetting the protective film forming film 13. Heating the protective film forming film 13 without thermosetting it can reduce the size of scratches on the surface of the protective film forming film 13, making the scratches on the surface of the protective film 13' less noticeable. The heating step in manufacturing method (1-2) can be performed in the same manner as the heating step in manufacturing method (1-1).

The wafer 902 with the protective film obtained above can be used to cleave wafer 9 and cut the protective film 13' to produce a chip with the protective film (illustration omitted).

[Variations on the Manufacturing Method of a Workpiece with a Protective Film] The manufacturing method of a workpiece with a protective film in this embodiment may also include other steps, without impairing the effectiveness of the invention, that are not equivalent to any of the aforementioned attaching step, conveying step, heating step, or thermosetting step. These other steps can be arbitrarily selected according to the purpose and are not particularly limited. The timing of performing these other steps can be appropriately selected according to the content of the other steps.

As an example of the other steps mentioned above in the aforementioned method for manufacturing a wafer with a protective film, if the wafer is equipped with a back polishing tape on the electrical surface, a back polishing tape removal step can be listed, which removes the back polishing tape from the electrical surface of the wafer before the aforementioned attachment step. The aforementioned back polishing tape can be a known back polishing tape, and the attachment of the back polishing tape to the electrical surface of the wafer and its removal from the electrical surface of the wafer can be performed by known methods.

Up to this point, the manufacturing methods (1-1) and (1-2) described above have explained the case of forming film 13 using the protective film shown in FIG1. However, in the manufacturing method of the workpiece with a protective film in this embodiment, protective film forming composite sheets such as the protective film forming composite sheet 101 shown in FIG2, the protective film forming composite sheet 102 shown in FIG3, the protective film forming composite sheet 103 shown in FIG4, and the protective film forming composite sheet 104 shown in FIG5 can also be used. When using the aforementioned protective film forming composite sheets, based on the difference in the composition between the aforementioned protective film forming composite sheets and the protective film forming film 13 shown in FIG1, the manufacturing method of the workpiece with a protective film in this embodiment can also include performing the other steps mentioned above at any time.

◇Method for manufacturing a workpiece with a protective film (Method for using a protective film forming film and a composite sheet for forming a protective film) The aforementioned protective film forming film and composite sheet for forming a protective film can be used to manufacture a workpiece with a protective film, which consists of a workpiece obtained by processing a workpiece and a protective film disposed at any location on the aforementioned workpiece. The method for manufacturing a workpiece with a protective film in this embodiment differs from the method for manufacturing a workpiece with a protective film described above in that it includes a step of manufacturing a workpiece by processing a workpiece.

The method for manufacturing a workpiece with a protective film according to this embodiment includes the following steps: an attachment step, in which the aforementioned protective film forming film, which does not constitute the aforementioned protective film forming composite sheet, or the protective film forming film in the aforementioned protective film forming composite sheet, is attached to the target area of the aforementioned workpiece, thereby producing a workpiece with a protective film forming film formed by having the aforementioned workpiece and the protective film forming film; a processing step, in which the aforementioned workpiece is processed after the attachment step, thereby producing the aforementioned workpiece; and a thermosetting step, in which the aforementioned protective film forming film is thermoset after the attachment step, thereby forming the aforementioned protective film. When the workpiece is a wafer, the aforementioned workpiece with a protective film can be exemplified by a wafer having a wafer and a protective film disposed on the inner surface of the wafer. The aforementioned method for manufacturing a wafer with a protective film comprises the following steps: an attachment step, in which a protective film forming film that does not constitute the aforementioned protective film forming composite, or a protective film forming film in the aforementioned protective film forming composite, is attached to the inner surface of a wafer, thereby producing a wafer with a protective film forming film formed by having the aforementioned wafer and the aforementioned protective film forming film disposed on the inner surface of the aforementioned wafer; a processing step (also known as a "dicing step"), in which the aforementioned wafer is diced after the aforementioned attachment step, thereby producing a wafer; and a thermosetting step, in which the aforementioned protective film forming film is thermoset after the aforementioned attachment step, thereby forming the aforementioned protective film.

[Manufacturing Method of a Wafer with Protective Film (Manufacturing Method (2-1))] Hereinafter, as a method for manufacturing a workpiece with a protective film, a method for manufacturing a wafer with a protective film will be described as an example, with reference to the drawings. Figure 8 is a cross-sectional view schematically illustrating one example of a manufacturing method in this embodiment of the method for manufacturing a wafer with a protective film using a protective film forming film that does not constitute a composite sheet for forming a protective film (sometimes referred to as "manufacturing method (2-1)" in this specification). Here, the case of using a protective film forming film 13 as shown in Figure 1 will be described.

In the attachment step prior to the aforementioned manufacturing method (2-1), as shown in FIG8(a), the surface 13a of the protective film forming film 13 with the first peeling film 151 removed is attached to the inner surface 9b of the wafer 9, thereby producing a wafer 901 with a protective film forming film.

The attachment step described in manufacturing method (2-1) can be performed using the same method as the attachment step described in manufacturing method (1-1), such as the lamination roller method. In the attachment step described in manufacturing method (2-1), as in manufacturing method (1-1), sometimes indentations such as pressure marks 18 (not shown) are formed on the surface 13b of the protective film forming film 13 that is opposite to the wafer 9 side.

Before the attachment step and the processing step described in the aforementioned manufacturing method (2-1), as shown in FIG8(b), the second release film 152 is removed from the wafer 901 with the protective film forming film, and the cutting disc 80 is attached to the newly exposed surface (i.e., the second surface 13b of the protective film forming film 13). The cutting disc 80 has a substrate 81 and an adhesive layer 82 disposed on one side of the substrate 81. In this step, the side of the adhesive layer 82 opposite to the side of the substrate 81 (sometimes referred to as the "first surface" in this specification) 82a is attached to the second surface 13b of the protective film forming film 13. The first surface 82a of the adhesive layer 82 is the same as the first surface 80a of the cutting disc 80. Thus, the aforementioned manufacturing method (2-1) includes a dicing attachment step, in which a dicing piece is attached to the side of the protective film that is opposite to the wafer side in the aforementioned wafer with the protective film forming film between the aforementioned attachment step and the aforementioned processing step.

The cutting disc 80 may also be the same as the support disc 10 in the composite sheet 101 for forming the protective film. The use of the cutting disc 80 is shown here, but in the manufacturing method (2-1), a known cutting disc other than the cutting disc 80 may also be used, such as a cutting disc made only of a substrate.

The attachment of the protective film forming film 13 to the cutting disc 80 can be carried out by a known method, for example, by the same method as the attachment of the protective film forming film 13 to the wafer 9 in the attachment step described earlier in manufacturing method (1-1).

When the dicing die 80 is attached to the surface 13b of the protective film forming film 13, for example, particulate foreign matter 17 may be mixed between the dicing die 80 and the laminating roller 161, and scratches such as indentations 18 (not shown) may be formed on the surface 13b of the protective film forming film 13 that is opposite to the wafer 9.

Following the aforementioned bonding step in the aforementioned manufacturing method (2-1), the wafer 90 is fabricated by dicing the wafer 9 in the aforementioned processing step. Furthermore, following the aforementioned bonding step, the protective film forming film 13 is cut in the cutting step. By performing the aforementioned processing step and cutting step, as shown in FIG8(c), a wafer 913 with a protective film forming film is fabricated, consisting of a wafer 90 and a cut protective film forming film 130 disposed on the inner surface 90b of the wafer 90. A wafer group 903 with a protective film forming film is fabricated and held in an orderly manner on the support sheet 10, consisting of multiple wafers 913 with protective film forming films. In Figure 8(c), symbol 130a represents the first side of the protective film forming film 130 after it has been cut, corresponding to the first side 13a of the protective film forming film 13. Furthermore, symbol 130b represents the second side of the protective film forming film 130 after it has been cut, corresponding to the second side 13b of the protective film forming film 13.

In manufacturing method (2-1), it is preferable to perform the aforementioned processing step and the aforementioned cutting step simultaneously after the aforementioned attachment step, or to perform the aforementioned processing step and then perform the aforementioned cutting step. In manufacturing method (2-1), when wafer processing (division) and the cutting of the protective film formation film can be performed continuously in the same manner without interruption by the same operation, regardless of the order, it is considered that the processing step and the cutting step are performed simultaneously.

The aforementioned processing and cutting steps can be performed using known methods in the order in which they are performed.

For example, when processing and cutting steps are performed simultaneously, wafer 9 can be diced and protective film 13 can be cut simultaneously using various cutting methods such as blade cutting, laser cutting using laser irradiation, or water cutting by spraying water containing abrasive. Furthermore, wafer 9 dicing and protective film 13 cutting can also be performed simultaneously by: for wafer 9, which has a modified layer formed by stealth dicing (registered trademark) and has not been diced, and the protective film 13, a so-called expansion is performed simultaneously, stretching in a direction parallel to their surfaces. This expansion is preferably performed at a low temperature such as -20°C to 5°C.

Stealth dicing (registered trademark) is a method as follows: First, a predetermined dicing area is defined inside the wafer. Laser light is then focused onto this area, creating a modified layer inside the wafer. This modified layer differs from other parts of the wafer; it is altered and weakened by laser light irradiation. Therefore, by applying force to the wafer, cracks extending towards both sides of the wafer are created within the modified layer, forming the starting point for wafer dicing. Then, force is applied to the wafer to dice it at the aforementioned modified layer, thus producing a chip.

For example, by performing the aforementioned processing steps and cutting steps in manufacturing method (2-1), as shown in FIG8(c), a wafer 913 with a protective film forming film is manufactured, and a wafer group 903 with a protective film forming film is formed by holding multiple wafers 913 with protective film forming film in a neat arrangement on the dicing wafer 80.

By performing the aforementioned thermosetting step after the processing step and cutting step in manufacturing method (2-1), as shown in FIG8(d), a protective film wafer 913' is manufactured, and a protective film wafer group 904 is formed by holding multiple such protective film wafers 913' in a neatly arranged state on the dicing wafer 80.

In Figure 8(d), symbol 130a’ represents the first side of the protective film 130’, corresponding to the first side 130a of the protective film formed after cutting. Moreover, symbol 130b’ represents the second side of the protective film 130’, corresponding to the second side 130b of the protective film formed after cutting.

The thermosetting step in manufacturing method (2-1) can be performed in the same manner as the thermosetting step in manufacturing method (1-1).

In the case of manufacturing method (2-1), the protective film forming film of the above embodiment is also used. Therefore, similar to the case of manufacturing method (1-1), if there are scratches such as indentations 18 on the surface of the protective film forming film 13, the scratches can still be reduced by performing a heat curing step and by the self-repairing effect caused by heating, and the scratches on the surface of the protective film 13' become less noticeable.

The aforementioned manufacturing method (2-1) preferably includes a heating step that heats the protective film forming film 130 without subjecting it to heat curing, either after the aforementioned attachment step and before the aforementioned processing step, or after the aforementioned processing step and before the aforementioned thermosetting step. By heating the protective film forming film 130 without subjecting it to heat curing, scratches on the surface of the protective film forming film 130 can be reduced, and scratches on the surface of the protective film 130' can be made less noticeable. The heating step in manufacturing method (2-1) can be performed in the same manner as the heating step in manufacturing method (1-1).

In the aforementioned heating step and the aforementioned thermosetting step, the wafer group 903 with the protective film forming film can be arranged with its surfaces (e.g., the first surface 130a of the cut protective film forming film 130 and the inner surface 90b of the wafer 90) parallel to the horizontal direction (so-called "horizontal"), and the protective film forming film 130 can be heated for thermosetting. On the other hand, in the aforementioned heating step and the aforementioned thermosetting step, the wafer group 903 with the protective film forming film can also be arranged with its surfaces (same as above) orthogonal to the horizontal direction (in other words, parallel to the vertical direction) (so-called "vertical"), and the protective film forming film 130 can be heated for thermosetting. When the wafer group 903 with the protective film forming film is arranged longitudinally and heated, compared with the case of being arranged horizontally and heated, sagging can be suppressed in the area of the wafer 913' with the protective film in the dicing die 80.

Following the thermosetting step described in manufacturing method (2-1), as shown in Figure 8(e), the target protective film wafer 913' can be removed by picking it up from the dicing die 80 in the protective film wafer group 904 through a picking step. In the picking step described in manufacturing method (2-1), a peeling occurs between the second surface 130b' of the protective film 130' in the protective film wafer 913' and the first surface 82a of the adhesive layer 82 in the dicing die 80.

The wafer 913' with a protective film can be picked up using known methods. The wafer 913' with a protective film can be picked up using a lifting mechanism such as a ejector pin. Here, we illustrate the case where a pulling mechanism 800, such as a vacuum clamp, is used to pull the wafer 913' with a protective film in the direction of arrow P. Furthermore, only the pulling mechanism 800 is shown, and its cross-section is omitted.

[Manufacturing Method of a Chip with a Protective Film (Manufacturing Method (2-2))] Figure 9 is a cross-sectional view schematically illustrating one example of a manufacturing method (sometimes referred to as "Manufacturing Method (2-2)") in which a protective film forming composite sheet is used in the manufacturing method of a chip with a protective film according to this embodiment is employed. Here, the case of using the protective film forming composite sheet 101 as shown in Figure 2 will be explained.

In the attachment step described in the aforementioned manufacturing method (2-2), as shown in FIG9(a), a wafer 901 with a protective film is manufactured by attaching the protective film forming film 13 (more specifically, the protective film forming film 13 with the peeling film 15 removed) of the protective film forming composite 101 to the inner surface 9b of the wafer 9.

In manufacturing method (2-2), apart from the aforementioned aspect of replacing the wafer 901 with a protective film forming film with a support sheet 10 with the aforementioned protective film forming film with a support sheet 10 after the attachment step, and the aspect of performing a pick-up step before the thermosetting step, the processing steps and cutting steps can be performed in the same manner as in manufacturing method (2-1).

For example, in manufacturing method (2-2), by performing the aforementioned processing steps and dicing steps, as shown in FIG. 9(b), a wafer 913 with a protective film is fabricated, and a wafer group 905 consisting of multiple wafers 913 with protective film forming films is fabricated on the support sheet 10 in a neatly arranged state. The wafer group 905 with protective film forming films is the same as the wafer group 903 with protective film forming films in manufacturing method (2-1), except that the support sheet 10 is used instead of the dicing sheet 80. The dicing method of wafer 9 can also be the same as the dicing method of wafer 9 in the aforementioned processing steps of manufacturing method (2-1). In manufacturing method (2-2), the cutting of the protective film forming film 13 can also be a known method, for example, it can be the same as the cutting method of the protective film forming film 13 in the cutting step described above in manufacturing method (2-1).

By using the obtained wafer 913 with the protective film formation film, the wafer 913 with the protective film formation film is peeled off from the support sheet 10 and picked up, as shown in FIG. 9(c). The wafer 913 with the protective film formation film can be removed. The steps at this time can also be the same as the picking steps described in manufacturing method (2-1). In the picking steps described in manufacturing method (2-2), peeling occurs between the second surface 130b of the protective film formation film 130 in the wafer 913 with the protective film formation film and the first surface 12a of the adhesive layer 12 in the support sheet 10.

If the wafer 913 with the protective film forming film is picked up using a lifting mechanism such as a pin, sometimes a dent (pin mark) or other scratches are formed at the lifting point of the protective film forming film 130.

After the picking step in the aforementioned manufacturing method (2-2), in the aforementioned thermosetting step, the protective film forming film 130 in the wafer 913 with the protective film forming film is thermoset to form a protective film 130', thereby manufacturing a wafer 913' with a protective film.

In Figure 9(d), symbol 130a’ represents the first side of the protective film 130’, corresponding to the first side 130a of the protective film formed after cutting. Moreover, symbol 130b’ represents the second side of the protective film 130’, corresponding to the second side 130b of the protective film formed after cutting.

The thermosetting step in manufacturing method (2-2) can be performed in the same manner as the thermosetting step in manufacturing method (1-1).

When using the previous protective film forming method, if scratches such as dents (not shown) are formed on the surface 130b of the protective film forming film 13, which is opposite to the wafer 9, the scratches will remain even after the thermosetting step, resulting in defective products. In contrast, when using the protective film forming film manufacturing method (2-2) of this embodiment, if scratches are formed on the surface of the protective film forming film 13, the scratches can be reduced by performing the thermosetting step due to the self-repairing effect caused by heating, and the scratches on the surface of the protective film 13' become less noticeable.

Preferably, the aforementioned manufacturing method (2-2) includes a heating step after the aforementioned picking step and before the aforementioned thermosetting step, in which the protective film forming film 130 is heated without thermosetting the protective film forming film 130. By heating the protective film forming film 130 without thermosetting the protective film forming film 130, the scratches on the surface of the protective film forming film 130 can be reduced, and the scratches on the surface of the protective film 130' become less noticeable. The heating step in manufacturing method (2-2) can be performed in the same manner as the heating step in manufacturing method (1-1).

Up to this point, the manufacturing method (2-2) described above has explained the case using the protective film forming composite sheet 101 shown in FIG. 2. However, in the manufacturing method of the workpiece with a protective film in this embodiment, other protective film forming composite sheets, such as the protective film forming composite sheet 102 shown in FIG. 3, the protective film forming composite sheet 103 shown in FIG. 4, and the protective film forming composite sheet 104 shown in FIG. 5, can also be used. When using the aforementioned other protective film forming composite sheets, based on the differences in the composition between the aforementioned other protective film forming composite sheets and the protective film forming composite sheet 101 shown in FIG. 2, the manufacturing method of the workpiece with a protective film in this embodiment can also perform the aforementioned other steps at any time.

Up to this point, as described in the aforementioned manufacturing method (2-2), a method for manufacturing a wafer with a protective film using a protective film forming composite has been explained. However, even if a protective film forming film that does not constitute a protective film forming composite is used instead of the protective film forming composite, a wafer with a protective film can still be manufactured.

[Variations on the Manufacturing Method of a Workpiece with a Protective Film] The manufacturing method of a workpiece with a protective film of this embodiment may also include other steps, without impairing the effectiveness of the invention, that are not equivalent to any of the aforementioned attachment step, processing step, cutting step, heating step, thermosetting step, pickup step, or cutting disc attachment step. These other steps can be arbitrarily selected according to the purpose and are not particularly limited. The timing of performing these other steps can be appropriately selected according to their content.

As an example of the aforementioned other steps in the method for manufacturing a wafer with a protective film, the following steps can be listed: a back-side polishing tape attachment step, in which a back-side polishing tape is attached to the electrical surface of the wafer before the attachment step; and a back-side polishing tape removal step, in which the back-side polishing tape is removed from the electrical surface of the wafer after the attachment step and before the processing step and the cutting step. The back-side polishing tape can be a known type of back-side polishing tape, and the attachment and removal of the back-side polishing tape from the electrical surface of the wafer can be performed by known methods.

In this specification, the term "attachment step" is not equivalent to either "dicing disc attachment step" or "back grinding tape attachment step," but refers to the aforementioned step of attaching the protective film forming film, or the protective film forming film in the aforementioned protective film forming composite sheet, to the target area of the workpiece (e.g., the inner surface of a wafer).

As another example of the aforementioned other steps in the method for manufacturing a wafer with a protective film, a printing step is provided, performed after the aforementioned attachment step and before the aforementioned pick-up step, on the side of the protective film forming film or the protective film opposite to the wafer side or the wafer side. Laser printing on the protective film forming film or the protective film can be performed using known methods.

◇Method for manufacturing substrate device (method for using workpiece with protective film) After obtaining workpiece with protective film by the above manufacturing method, except that the workpiece with protective film is used to replace the previous workpiece with protective film, the substrate device can be manufactured in the same way as the previous substrate device manufacturing method.

As a method for manufacturing such a substrate device, one example is a method that includes the following flip-chip interconnection step: a protruding electrode on a workpiece with a protective film, obtained by forming the aforementioned protective film, is brought into contact with a connecting pad on a circuit substrate, thereby electrically connecting the protruding electrode to the connecting pad on the circuit substrate. [Example]

The present invention will now be described in more detail with reference to specific embodiments. However, the present invention is not limited to the embodiments shown below.

[Raw Materials for Resin Manufacturing] The formal names of the raw materials for resin manufacturing, as abbreviated in this embodiment and comparative example, are shown below. MA: Methyl acrylate HEA: 2-Hydroxyethyl acrylate 2EHA: 2-Ethylhexyl acrylate 2EHMA: 2-Ethylhexyl methacrylate GMA: Glycidyl methacrylate MMA: Methyl methacrylate BA: n-Butyl acrylate EA: Ethyl acrylate

[Raw Materials for Manufacturing Components for Protective Film Formation] The raw materials used to manufacture components for protective film formation are shown below.

[Polymer Composition (A)] (A)-1: An acrylic polymer copolymerized from 2EHA (65 parts by mass), MMA (25 parts by mass), and HEA (10 parts by mass) (weight average molecular weight: 500,000, glass transition temperature: -38°C) (A)-2: An acrylic polymer copolymerized from BA (40 parts by mass), EA (25 parts by mass), MMA (30 parts by mass), and GMA (5 parts by mass) (weight average molecular weight: 500,000, glass transition temperature: -9°C) (A)-3: An acrylic polymer copolymerized from 2EHA (30 parts by mass), EA (35 parts by mass), MMA (30 parts by mass), and GMA (5 parts by mass) (weight average molecular weight: 500,000, glass transition temperature: -12°C) (A)-4: A copolymer formed by copolymerizing 2EHA (73 parts by mass), MA (12 parts by mass), GMA (3 parts by mass), and HEA (12 parts by mass) (weight average molecular weight: 550,000, glass transition temperature: -55℃). (A)-5: A copolymer formed by copolymerizing 2EHA (12 parts by mass), MA (73 parts by mass), GMA (3 parts by mass), and HEA (12 parts by mass) (weight average molecular weight: 550,000, glass transition temperature: -5℃). (A)-6: A copolymer formed by copolymerizing 2EHMA (85 parts by mass), MA (7 parts by mass), and HEA (8 parts by mass) (weight average molecular weight: 650,000, glass transition temperature: -9℃). (A)-7: A copolymer formed by copolymerizing BA (60 parts by mass), MA (10 parts by mass), GMA (17 parts by mass), and HEA (13 parts by mass) (weight average molecular weight: 500,000, glass transition temperature: -31℃). (A)-8: A copolymer formed by copolymerizing MA (87 parts by mass) and HEA (13 parts by mass) (weight average molecular weight: 450,000, glass transition temperature: 6℃).

[Epoxy Resins (B1)] (B1)-1: Bisphenol A type epoxy resin (Mitsubishi Chemical Co., Ltd. "jER828", epoxy equivalent: 184g/eq to 194g/eq) (B1)-2: Dicyclopentadiene type epoxy resin (DIC Corporation "Epiclone HP-7200", epoxy equivalent: 254g/eq to 264g/eq) (B1)-3: Bisphenol type epoxy resin (Mitsubishi Chemical Co., Ltd. "jER1055", epoxy equivalent: 800g/eq to 900g/eq) (B1)-4: Dicyclopentadiene type epoxy resin (Nippon Kayaku Co., Ltd. "XD-1000", epoxy equivalent: 248g/eq) (B1)-5: Dicyclopentadiene type epoxy resin (DIC Corporation's "Epiclone HP-7200HH", epoxy equivalent: 274g/eq to 286g/eq) [Thermosetting agent (B2)] (B2)-1: Dicyandiamine (Thermoactive latent epoxy resin curing agent, Mitsubishi Chemical Corporation's "DICY7")

[Curing Accelerator (C)] (C)-1: 2-Phenyl-4,5-dihydroxymethylimidazolium (Curezole 2PHZ manufactured by Shikoku Chemical Industry Co., Ltd.) [Filler (D)] (D)-1: Silica filler (SC2050MA manufactured by Admatechs Co., Ltd., spherical silica filler with epoxy-modified surface, average particle size: 0.5μm) (D)-2: Silica filler (SV-10 manufactured by Ryusen Co., Ltd. (spherical silica filler with an average particle size of 10μm) is pulverized, and the average particle size after pulverization is 2.0μm) (D)-3: Silica filler (Admatechs "SC105G-MMQ", spherical silica filler with vinyl-modified surface, average particle size: 0.3μm) (E)-1: Oligomeric silane coupling agent with epoxy, methyl and methoxy groups (Shin-Etsu Chemical Co., Ltd. "X-41-1056", epoxy equivalent 280g/eq) [Coloring agent (I)] (I)-1: Organic black pigment (Dai-Nippon Seika Co., Ltd. "6377 Black") (I)-2: Carbon black (Mitsubishi Chemical Co., Ltd. "MA-600")

[Example 1] [Manufacturing of Protective Film Forming Film] [Manufacturing of Component (III)-1 for Protective Film Formation] Polymer component (A)-1 (30.1 parts by mass), epoxy resin (B1)-1 (12.0 parts by mass), epoxy resin (B1)-2 (6.0 parts by mass), thermosetting agent (B2)-1 (0.4 parts by mass), curing accelerator (C)-1 (0.4 parts by mass), filler (D)-1 (48.1 parts by mass), coupling agent (E)-1 (0.4 parts by mass), and colorant (I)-1 (2.5 parts by mass) are dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain a thermosetting protective film forming component (III)-1 with a total concentration of 60% by mass for all components other than the solvent. The amounts of components other than methyl ethyl ketone shown here are all solvent-free target amounts.

[Preparation of Protective Film Forming Film] Using a release membrane (second release membrane, manufactured by Lintec Corporation, "SP-PET502150", 50μm thick) on one side of a polyethylene terephthalate film treated with polysiloxane, the aforementioned protective film forming component (III)-1 was applied to the release-treated side of the release membrane and dried at 100°C for 2 minutes, thereby producing a thermosetting protective film forming film with a thickness of 40μm.

Furthermore, on the exposed surface of the obtained protective film forming film that does not have the second peeling film, a peeling treatment surface of the peeling film (first peeling film, manufactured by Lintec Corporation "SP-PET381031", thickness 38μm) is bonded at an bonding speed of 2m/min, a bonding temperature of 60°C, and a bonding pressure of 0.5MPa. This process creates a protective film forming film with a peeling film, consisting of a protective film forming film, a first peeling film disposed on one side of the aforementioned protective film forming film, and a second peeling film disposed on the other side of the aforementioned protective film forming film.

[Evaluation of the protective film forming film] [Determination of the storage elastic modulus E’(70) and E’(90) of the protective film forming film] Using the five protective film forming films with peeling membranes obtained above, while removing the first or second peeling membrane, the exposed surfaces of the protective film forming films were sequentially laminated together to create a laminate consisting of a second peeling membrane, five protective film forming films (total thickness 200 μm), and the second peeling membrane. In addition, slices with a width of 4 mm and a length of 30 mm were cut from the laminate with the length direction aligned with the MD direction of the protective film forming film. Next, the two outermost second exfoliating membranes were removed from the slice, and the resulting material was used as a test piece. Then, using a dynamic viscoelasticity automatic measuring device (A&D Corporation's "Rheovibron DDV-01FP"), the storage elastic modulus E' of the aforementioned test piece was measured in the temperature range of -50°C to 150°C under the following conditions: clamp spacing of 20 mm, frequency of 11 Hz, heating rate of 3°C/min, and constant heating. The storage elastic modulus E'(70) at 70°C and the storage elastic modulus E'(90) at 90°C are shown in Table 1. Furthermore, the tanδ(70) at 70°C and the tanδ(90) at 90°C are shown in Table 1.

[Determination of the storage elastic modulus E’(23) of the protective film] In the same manner as above, a laminate consisting of a second release membrane, five protective film forming films (total thickness 200 μm) and a second release membrane were sequentially laminated. A slice with a width of 5 mm and a length of 30 mm was cut from the laminate with the length direction aligned with the MD direction of the protective film forming film. The slice was heated at 90°C for 2 h, and then heated at 130°C for 2 h (two-stage heating). The two outermost second release membranes were then removed from the slice, and the obtained sample was used as a test piece. Subsequently, using a dynamic viscoelasticity measuring device (TA Instruments "DMAQ800"), the storage elastic modulus E' of the aforementioned specimen was measured in the temperature range of -60°C to 300°C under the following conditions: clamp spacing of 20 mm, frequency of 11 Hz, heating rate of 3°C/min, and constant heating. The storage elastic modulus E'(23) at 23°C is shown in Table 1.

[Evaluation of self-repairability (A)] Using a pick-and-place machine (Lintec Corporation, RAD-3600F/12), the first release film was removed from the protective film forming film with a release film obtained above. Impurities (tiny silicon foreign objects) with a thickness of 40μm, a length of 0.25mm, and a width of 0.25mm were carried from the side of the second release film and pressed with lamination rollers. In this way, the exposed protective film forming film was attached to the grinding surface of the silicon wafer (8-inch diameter, 350μm thickness, ♯2000 grinding) to create a stack of silicon wafer, protective film forming film, and second release film stacked in sequence. The second exfoliation membrane was peeled off, and the surface of the protective film was observed using a laser microscope (KEYENCE, VK-9700). Due to the embedding of impurities, a scratch with a depth of about 2.03 μm (that is, the depth of the scratch before heating) was observed on the surface of the protective film.

The protective film with scratches on its surface was heated at 90°C for 2 hours. Similarly, the surface of the protective film after heating was observed with a laser microscope, and scratches with a depth of about 0.26 μm (that is, the depth of the scratches after heating) were observed on the surface of the protective film.

The self-repair rate (A) [%] resulting from heating at 90°C for 2 hours is calculated using the following formula, rounding the first decimal place to the nearest integer. Self-repair rate (A) [%] = {(depth of the wound before heating - depth of the wound after heating) / depth of the wound before heating} × 100

Furthermore, the self-repair rate (A) [%] and the evaluation results based on the following criteria are shown in Table 1. A: 100% to 80% B: 79% to 60% C: 59% to 35% D: 34% to 15% E: 14% to 0%

[Evaluation of Self-Healing Property (C)] As described above, a protective film with a 2.07 μm deep scratch on its surface before heating was formed. The film was then heated at 90°C for 2 hours, followed by heating at 130°C for 2 hours. Similarly, the surface of the protective film was observed using a laser microscope. A scratch with a depth of approximately 0.18 μm (i.e., the depth of the scratch after heating at 90°C and then heat-hardening) was observed on the surface of the protective film.

The self-repair rate (C) [%] resulting from heating at 130℃ for 2 hours is calculated using the following formula, rounding off the first decimal place. Self-repair rate (C) [%] = {(depth of the scratch before heating - depth of the scratch after heating to 90℃ and then hardening) / depth of the scratch before heating} × 100

Table 1 shows the self-repair rate (C) [%] and the evaluation results based on the following criteria: A: 100% to 80% B: 79% to 60% C: 59% to 35% D: 34% to 15% E: 14% to 0%

[Evaluation of Self-Healing (B)] As described above, a protective film with a 2.01 μm deep scratch on its surface before heating was formed and heated at 130°C for 2 hours to create the protective film. Similarly, the surface of the protective film was observed using a laser microscope, and a scratch with a depth of approximately 0.80 μm (i.e., the depth of the scratch after heat hardening) was observed on the surface of the protective film.

The self-repair rate (B) [%] resulting from heating at 130°C for 2 hours is calculated using the following formula, rounding the first decimal place to the nearest integer. Self-repair rate (B) [%] = {(depth of the scratch before heating - depth of the scratch after heat hardening) / depth of the scratch before heating} × 100

The self-repair rate (B) [%] and the evaluation results based on the following criteria are shown in Table 1. (Evaluation Criteria) A: 100% to 80% B: 79% to 60% C: 59% to 35% D: 34% to 15% E: 14% to 0%

[Manufacturing and Evaluation of Protective Film Forming Film] [Examples 2 to 7, Comparative Examples 1 to 2] The protective film forming film and the composite sheet for forming the protective film were manufactured in the same manner as in Example 1, except that the types of ingredients were changed as shown in Table 1 or Table 2. The protective film forming film was evaluated. The results are shown in Table 1 or Table 2.

[Table 1] Implementation Example 1 Implementation Example 2 Implementation Example 3 Implementation Example 4 Implementation Example 5 The components (mass %) of the protective film forming film Polymer component (A) (A)-1 30.1 34.2 (A)-2 24.3 (A)-3 24.3 (A)-4 24.3 Epoxy resin (B1) (B1)-1 12.0 13.7 9.7 9.7 9.7 (B1)-2 6.0 6.8 4.9 4.9 4.9 Thermosetting agent (B2) (B2)-1 0.4 0.5 0.3 0.3 0.3 Hardening accelerator (C) (C)-1 0.4 0.5 0.3 0.3 0.3 Filler (D) (D)-1 48.1 41.0 58.2 58.2 58.2 Coupling agent (E) (E)-l 0.4 0.5 0.3 0.3 0.3 Colorant (I) (I)-1 2.5 2.9 2.0 2.0 2.0 total 100 100 100 100 100 Evaluation results The storage elastic modulus of the protective film formation membrane E'(70)/MPa 0.43 0.19 1.30 1.24 0.44 E'(90)/MPa 0.19 0.06 1.20 0.90 0.39 Protective film formation membrane tanδ tanδ(70) 0.51 0.50 0.35 0.43 0.37 tan δ (90) 0.36 0.34 0.29 0.34 0.24 Storage elastic modulus of protective film E'(23)/MPa 820 300 5100 2900 370 Self-repair rate (A) induced by heating at 90°C for 2 hours (A)/% 87 95 71 76 83 Evaluation results A A B B A Self-repair rate (B) resulting from heating at 130°C for 2 hours. (B)/% 60 71 52 55 58 Evaluation results B B C C C Self-repair rate (C) resulting from heating at 90°C for 2 hours and heating at 130°C for 2 hours. (C)/% 91 97 79 81 87 Evaluation results A A B A A

[Table 2] Implementation Example 6 Implementation Example 7 Comparative example 1 Comparative example 2 The components (mass %) of the protective film forming film Polymer component (A) (A)-5 24.3 (A)-6 24.3 (A)-7 18.7 (A)-8 25.6 Epoxy resin (B1) (B1)-1 9.7 9.7 11.2 10.2 (B1)-3 1.9 1.7 (B1)-5 5.1 (B1)-2 4.9 4.9 (B1)-4 5.6 Thermosetting agent (B2) (B2)-1 0.3 0.3 0.4 0.3 Hardening accelerator (C) (C)-1 0.3 0.3 0.4 0.3 Filler (D) (D)-2 54.1 (D)-1 58.2 58.2 5.6 (D)-3 54.6 Coupling agent (E) (E)-1 0.3 0.3 0.4 0.3 Colorant (I) (I)-2 1.9 1.7 (I)-1 2.0 2.0 total 100 100 100 100 Evaluation results The storage elastic modulus of the protective film formation membrane E'(70)/MPa 3.23 3.95 11.83 8.04 E'(90)/MPa 2.20 3.40 8.90 5.20 Protective film formation membrane tanδ tanδ(70) 0.43 0.36 0.41 0.42 tan δ (90) 0.31 0.21 0.33 0.25 Storage elastic modulus of protective film E'(23)/MPa 6900 2090 6720 7060 Self-repair rate (A) resulting from heating at 90°C for 2 hours (A)/% 41 29 5 10 Evaluation results C D E E Self-repair rate (B) resulting from heating at 130°C for 2 hours. (B)/% 37 twenty one 3 8 Evaluation results C D E E Self-repair rate (C) resulting from heating at 90°C for 2 hours and heating at 130°C for 2 hours. (C)/% 47 36 9 14 Evaluation results C C E E

As the results above indicate, no self-repairing effect was observed in the protective film-forming films of Comparative Examples 1 and 2 after heating at 90°C for 2 hours. Furthermore, no self-repairing effect was observed in the protective film-forming films of Comparative Examples 1 and 2 after heating at 130°C for 2 hours under normal heat curing conditions. Even after heating at 90°C for 2 hours and at 130°C for 2 hours, no self-repairing effect was observed.

In contrast, the protective film forming films of Examples 1 to 7 exhibited self-repairing properties when heated at 90°C for 2 hours. Furthermore, the protective film forming films of Examples 1 to 7 also exhibited self-repairing properties when heated at 130°C for 2 hours under normal heat curing conditions. Moreover, compared to heating at 130°C for 2 hours under normal heat curing conditions, superior self-repairing properties were observed when heated at 90°C for 2 hours and at 130°C for 2 hours. Therefore, in the process of manufacturing workpieces with protective films or processed workpieces with protective films using the protective film forming film of the present invention, or a composite sheet for forming protective films having the protective film forming film of the present invention, even if scratches are formed on the surface of the protective film forming film, the scratches on the surface of the protective film after thermosetting can still become less noticeable. [Industrial Applicability]

This invention can be used to manufacture various substrate devices, such as semiconductor devices.

7: Conveying mechanism 8: Platform 9: Wafer 9a: Wafer's electrical surface 9b: Inner surface of the wafer 10, 20: Support sheet 10a, 20a: One side of the support sheet (first side) 11, 81: Substrate 11a: One side of the substrate (first side) 12, 82: Adhesive layer 12a, 82a: First side of the adhesive layer 13, 23: Protective film forming film (thermosetting protective film forming film) 13a, 23a: One side of the protective film forming film (first side) 13b, 23b: The other side of the protective film forming film (second side) 13’, 130’: Protective film 13b’, 130b’: Second side of the protective film 130: Protective film forming film after cutting 130a: First side of the protective film formed after cutting 130b: Second side of the protective film formed after cutting 130a’: First side of the protective film 15: Peeling film 16: Adhesive layer for fixture 16a: First side of adhesive layer for fixture 17: Foreign matter 18: Indentation 19: Contact mark 80: Die 80a: First side of the die 90: Wafer 90b: Inner surface of the wafer 101, 102, 103, 104: Composite sheet for forming the protective film 151: First peeling film 152: Second peeling film 161: Lamination roller 800: Peeling mechanism 901: Wafer with protective film forming film 902: Wafer with protective film 903, 905: Wafer array with protective film formation 904: Wafer array with protective film 913: Wafer with protective film formation 913’: Wafer with protective film P: Pull-off direction

[Figure 1] is a schematic cross-sectional view illustrating an example of a protective film forming film according to an embodiment of the present invention. [Figure 2] is a schematic cross-sectional view illustrating an example of a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 3] is a schematic cross-sectional view illustrating another example of a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 4] is a schematic cross-sectional view illustrating yet another example of a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 5] is a schematic cross-sectional view illustrating yet another example of a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 6] is a cross-sectional view illustrating an example of a method for manufacturing a wafer with a protective film according to an embodiment of the present invention. [Figure 7] is a cross-sectional view illustrating another example of a method for manufacturing a wafer with a protective film according to an embodiment of the present invention. [Figure 8] is a cross-sectional view illustrating another example of a method for manufacturing a chip with a protective film according to an embodiment of the present invention. [Figure 9] is a cross-sectional view illustrating another example of a method for manufacturing a chip with a protective film according to an embodiment of the present invention.

13: Protective film formation (thermosetting protective film formation)

13a: Protective film forming one side of the film (first side)

13b: The protective film forms the other side (second side) of the membrane.

151: First membrane exfoliation

152: Second exfoliation membrane

Claims (8)

A protective film forming film with thermosetting properties; a 4 mm wide sample of the aforementioned protective film forming film is held at two locations with a 20 mm interval, and the sample is heated from -50 °C to 150 °C in a stretching mode at a frequency of 11 Hz, a heating rate of 3 °C/min, and a constant heating rate, while the storage elastic modulus E’ of the aforementioned sample is measured. Before 90 °C, the storage elastic modulus E’(90) of the aforementioned sample is 5 MPa or less. As described in claim 1, when a 4 mm wide sample of the aforementioned protective film is held at two locations with a 20 mm interval, and the sample is heated from -50 °C to 150 °C in a stretching mode at a frequency of 11 Hz, a heating rate of 3 °C/min, and a constant heating rate, the tanδ of the sample is measured, and the tanδ(90) of the sample is 0.34 or higher before 90 °C. As described in claim 1 or 2, when a 5 mm wide specimen of the heat-cured material of the aforementioned protective film is held at two locations with a 20 mm interval, and the specimen is heated from -60°C to 300°C in a stretching mode at a frequency of 11 Hz, a heating rate of 3°C/min, and a constant heating rate, the storage elastic modulus E’ of the aforementioned specimen is measured, and the storage elastic modulus E’(23) of the aforementioned specimen is 100 MPa or more before 23°C. The protective film formed as described in claim 1 or 2 contains a polymer component (A) comprising acrylic resin; the glass transition temperature of the aforementioned acrylic resin does not reach 10°C. The protective film forming film described in claim 1 or 2 contains filler (D); the content of the aforementioned filler (D) is less than 50% of the total mass of the aforementioned protective film forming film. A composite sheet for forming a protective film comprises a support sheet and a protective film forming film disposed on one side of the support sheet; the protective film forming film is the protective film forming film as described in any one of claims 1 to 5. A method for manufacturing a workpiece with a protective film, wherein the workpiece with a protective film comprises a workpiece and a protective film disposed at any location on the workpiece; the manufacturing method comprises the following steps: an attachment step, wherein a protective film forming film as described in any one of claims 1 to 5, or a protective film forming composite sheet as described in claim 6, is attached to a target area of the workpiece, thereby producing a workpiece with a protective film forming film comprising the workpiece and the protective film forming film; a thermosetting step, wherein after the attachment step, the protective film forming film is thermoset to form the protective film, thereby producing the workpiece with the protective film. A method for manufacturing a workpiece having a protective film, wherein the workpiece having a protective film comprises a workpiece obtained by processing a workpiece and a protective film disposed at any location on the workpiece; the manufacturing method comprises the following steps: an attachment step, wherein a protective film forming film as described in any one of claims 1 to 5, or a protective film forming composite sheet as described in claim 6, is attached to a target area of the workpiece, thereby producing a workpiece having the workpiece and the protective film forming film; a processing step, wherein after the attachment step, the workpiece is processed to produce the workpiece; and a thermosetting step, wherein after the attachment step, the protective film forming film is thermoset to form the protective film.