TWI891990B - Method for treating workpiece - Google Patents

Abstract

The present invention provides a method for treating workpiece, in which a workpiece such as wafer is treated in the state of a laminate that is obtained by fixing the workpiece to a support via a temporarily fixing material, and the method is capable of stably peeling the workpiece off the laminate by a relatively simple process such as mechanical peeling. This object can be solved by a method for treating workpiece that includes the following steps: step (1) of laminating a support (A), a temporarily fixing material (B), and a workpiece (C) situated on a surface of the temporarily fixing material (B) opposite to the side of the support (A); step (2) of applying at least one treatment selected from heat treatment, mechanical treatment, wet processing, and laser processing; and step (3) of separating the workpiece (C) from the laminate (D) having the treated workpiece (C); the ratio of “the 10° peeling strength P₁ between the support (A)/adhesive layer (B)” to “the 10° peeling strength P₂ between the adhesive layer (B)/workpiece (C)” (P₂/P₁) measured when each angle formed by the peeled layers is maintained at 10° is 1.1 or more.

Description

Workpiece processing method

The present invention relates to a method for processing a workpiece, such as a wafer, while the workpiece is secured to a support by a temporary fixture. More specifically, the method improves workpiece handling by introducing a support, enabling various processing steps. The method also allows for stable separation of the workpiece using simpler processes, such as mechanical peeling.

In semiconductor manufacturing processes, temporary fixation of workpieces during handling is sometimes necessary or desirable due to the thinness and fragility of the workpiece. For example, wafers containing the functional layers for semiconductor components are often thinned due to the high density of semiconductor components. However, when thinned to the extreme thickness, adhesive tape alone is insufficient to support the wafer. Therefore, a temporary fixation material is used to temporarily secure the wafer to a rigid carrier (support) for post-thinning processing. Semiconductor manufacturing processes using this support are called wafer support systems.

Methods proposed for peeling the support after treatment include generating gas from a temporary fixing material (see, for example, Patent Document 1), using lasers for peeling, melting the resin of the temporary fixing material to cause the carrier to slide, and pulling up one end of the carrier for peeling (mechanical peeling).

Mechanical peeling offers a cost advantage due to its simpler equipment. However, in principle, mechanical peeling requires applying peeling force at least at the workpiece/temporary fixture interface and the temporary fixture/support interface. Therefore, stable peeling at the intended interface is not always easy. If peeling occurs at an unintended interface (such as the workpiece/temporary fixture interface), it can cause damage to the support or electronic components during peeling.

On the other hand, to prevent peeling from unintended interfaces during mechanical peeling, the adhesion strength at unintended interfaces can be increased. However, if the adhesion strength is increased excessively, it will become difficult to peel the temporary fixing material from the workpiece, for example.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] International Publication No. 2014/024861 A1

In view of the above technical background, the object of the present invention is to provide a method for processing workpieces such as wafers, wherein the workpiece is secured to a support laminate by a temporary fixing material, and the wafer or other workpiece can be reliably separated from the laminate using a relatively simple process such as mechanical peeling.

The inventors of this case conducted in-depth research and discovered that in a workpiece processing method in which a workpiece such as a wafer is secured to a support structure by a temporary fixing material while being processed, when the peel strength between the support structure/temporary fixing material and the peel strength between the temporary fixing material and the workpiece, measured under specific conditions, satisfies these conditions. This led to the completion of the present invention by using a relatively simple process, such as mechanical peeling, to reliably separate the wafer or other workpiece from the stack.

That is, the present invention relates to the following:

[1]

A workpiece processing method comprises the following steps:

Step (1) stacking the support body (A), the temporary fixing material (B), and the workpiece (C) located on the side of the temporary fixing material (B) opposite to the support body (A);

Step (2), subjecting the workpiece (C) to at least one treatment selected from heat treatment, machining treatment, wet treatment and laser processing treatment; and

Step (3), separating the workpiece (C) from the laminate (D) having the processed workpiece (C); wherein,

The ratio P 2 / P 1 of the 10° peeling strength P ₁ between the support (A) and the temporary fixing material (B) to the 10° peeling strength P ₂ between the temporary fixing material (B) and the workpiece (C) measured while maintaining the angle between the peeled layers at ₁₀ ° is _1.1 or higher.

The following [2] to [13] are all preferred aspects or implementation forms of the present invention.

[2]

A method for processing a workpiece as described in [1], wherein the peeling strength _P1 is less than 10N/25mm.

[3]

A method for processing a workpiece as described in [1] or [2], wherein the temporary fixing material (B) has a different composition in the adhesive layer connected to the support body (A) and the adhesive layer connected to the workpiece (C).

[4]

The method for processing a workpiece as described in any one of [1] to [3] is to separate the support body (A) from the temporary fixing material (B), and then remove the temporary fixing material (B) remaining on the workpiece (C), thereby achieving separation of the workpiece (C) from the laminate (D).

[5]

A method for processing a workpiece as described in [4], wherein the method for separating the temporary fixing material (B) and the supporting body (A) is mechanical peeling.

[6]

A method for processing a workpiece as described in any one of [1] to [5], wherein the temporary fixing material (B) contains a hardening adhesive component.

[7]

A method for processing a workpiece as described in any one of [1] to [5], wherein the temporary fixing material (B) contains a release agent.

[8]

A workpiece processing method as described in any one of [1] to [7], wherein the temporary fixing material (B) is formed by bonding the material on both sides of the base film (B ₀ ).

[9]

A wafer processing method as described in any one of [1] to [8], wherein the thickness of the workpiece (C) after processing in step (2) is greater than 1 μm and less than 200 μm.

[10]

A method for processing a workpiece as described in any one of [1] to [8], wherein the thickness of the workpiece (C) is at least temporarily greater than 1 μm and less than 200 μm.

[11]

A method for manufacturing an electronic device, comprising the steps of implementing the workpiece processing method described in any one of [1] to [10].

[12]

The method for manufacturing an electronic device as described in [11], wherein the electronic device has a structure formed by laminating semiconductor chips.

[13]

A laminated body (D) is formed by laminating a support (A), a temporary fixing material (B), and a workpiece (C) located on the side of the temporary fixing material (B) opposite to the support (A), wherein:

The ratio P 2 / P 1 of the 10° peeling strength P ₁ between the support (A) and the temporary fixing material (B) to the 10° peeling strength P ₂ between the temporary fixing material (B) and the workpiece (C) measured while maintaining the angle between the peeled layers at ₁₀ ° is _1.1 or higher.

The workpiece processing method of the present invention improves the handling efficiency of thin or fragile workpieces, allowing for stable processing of wafers and other workpieces in various processing steps. It effectively suppresses delamination at unintended interfaces, allowing for stable separation and removal of processed wafers and other workpieces using simpler and lower-cost processes such as mechanical peeling. This method allows for high productivity and yield in performing a large number of steps on wafers and other workpieces without damaging electronic components such as functional layers formed on them, significantly improving the productivity of electronic devices and other electronic components.

11: Support body (A)

12: Temporary fixing material (B)

13: Workpiece (C)

14: Cutting tape

15: Ring frame

16: Remover

17: Adhesive Tape

18: Adhesive layer ( _B2 ) on the workpiece (C) side

19: Base film (B ₀ )

20: Adhesive layer ( _B1 ) on the support body (A) side

21: Polyimide film

Figure 1 is a schematic diagram illustrating mechanical peeling in one embodiment of the present invention.

Figure 2 is a schematic diagram illustrating the separation of a support body (A) from a laminate (D) in one embodiment of the present invention. (a) shows a preferred separation pattern, while (b) to (c) show poor separation patterns.

FIG3 is a schematic diagram illustrating a specific method for measuring 10° peel strength in the present invention. (a) shows a measurement of the 10° peel strength _P1 using a sample formed by an adhesive layer ( _B1 ) on the side where the substrate film ( _B0 ) is laminated and the support (A). (b) shows a measurement of the 10° peel strength P2 using a sample formed by an adhesive layer ( _B2 ) on the side where the substrate film (B0) is laminated and the workpiece (C). (c) shows a measurement of the 10° peel strength _P2 using a sample formed by an adhesive layer ( _B2 ) on the side where the substrate film (B0) is laminated and the workpiece (C) _. (a) shows a case where a polyimide film-laminated sample was prepared using a temporary fixing material (B) having a substrate film ( _B0 ) and the 10° peeling strength _P1 was measured. (d) shows a case where a polyimide film-laminated sample was prepared using a temporary fixing material (B) having no substrate film (B0) and the 10° peeling strength _P2 was measured.

FIG4 is a schematic diagram showing a method for evaluating the removability of a temporary fixing material (B) from a workpiece (C) according to one embodiment of the present invention.

Figure 5 is a schematic diagram showing a laminate (D) in one embodiment of the present invention.

Figure 6 is a schematic diagram showing a laminate (D) in another embodiment of the present invention.

The workpiece processing method of the present invention has the following features:

Step (1) stacking the support body (A), the temporary fixing material (B), and the workpiece (C) located on the side of the temporary fixing material (B) opposite to the support body (A);

Step (2), subjecting the workpiece (C) to at least one treatment selected from heat treatment, machining treatment, wet treatment and laser processing treatment; and

Step (3), separating the workpiece (C) from the laminate (D) having the processed workpiece (C);

The ratio P 2 / P 1 of the 10° peeling strength P ₁ between the support (A) and the temporary fixing material (B) to the 10° peeling strength P ₂ between the temporary fixing material (B) and the workpiece (C) measured while maintaining the angle between the peeled layers at ₁₀ ° is 1.1 or _higher .

That is, in the processing method of the present invention, a support body (A) and a temporary fixing material (B) serving as a temporary fixing material are used when processing a workpiece (C).

[Support body (A)]

The support (A) preferably has sufficient strength and rigidity, as well as excellent heat and chemical resistance. Using such a support (A) allows for stable handling of the workpiece (C) even when it has been thinned, and allows for numerous and/or diverse processes to be performed on the workpiece (C) without causing any warping. For example, various processes required to manufacture electronic devices with structures such as TSV connections formed on semiconductor wafers can be applied to the workpiece (C) having electronic circuits formed thereon.

Suitable materials for the support (A) include silicon, sapphire, crystal, metals (such as aluminum, copper, and steel), various types of glass, and ceramics. The support (A) can be composed of a single material or multiple materials, and can also include other materials deposited on a substrate. For example, a silicon wafer can also have a deposited layer such as silicon nitride.

In order to adjust the 10° peel strength P ₁ between the temporary fixing material (B), surface treatment such as providing a polysilicone layer may also be performed.

Depending on the temperature of the process for manufacturing the laminate (D), the support (A) can also be made of plastic. For example, sheets made of plastics such as polyimide, acrylic, polyolefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), nylon, and urethane are preferably used as the support (A). Polyimide is particularly preferred due to its heat resistance.

To ensure uniform thickness of the workpiece (C) after grinding, the thickness of the support (A) should be uniform. For example, to thin the silicon wafer used as the workpiece (C) to less than 50μm and maintain uniformity within ±10%, the thickness variation of the support (A) should be kept within ±2μm.

The thickness of the support (A) is not particularly limited, but from the perspective of effectively preventing the workpiece (C) from bending, it is preferably 300 μm or greater, and particularly preferably 500 μm or greater. From the perspective of reducing the total weight during operation or the stress required for mechanical peeling, it is preferably 1500 μm or less, and particularly preferably 1000 μm or less.

[Temporary fixing material (B)]

The temporary fixing material (B) is used to fix the workpiece (C) to the support (A).

The temporary fixing material (B) is preferably easily removable from the support (A) and the workpiece (C). Therefore, the temporary fixing material (B) preferably has sufficient adhesion to secure the workpiece (C) to the support (A), but low enough adhesion to allow for removability.

The temporary fixing material (B) is preferably an adhesive. The adhesive used in this embodiment may be, for example, a rubber-based, acrylic-based, epoxy-based, urethane-based, allyl-based, silicone-based, fluorine-based, or polyimide-based adhesive. Of these, acrylic-based or silicone-based adhesives are preferred due to their heat resistance and ease of adjusting adhesion and bonding strength.

The adhesive can be either a hardening or non-hardening adhesive. However, hardening adhesives are preferred because they harden before heat treatment, making it less likely to cause voids during heat treatment during the manufacturing process, preventing subsequent aging caused by high heat treatment temperatures, and allowing for easy peeling without leaving adhesive residue.

Examples of these hardening adhesives include light-hardening adhesives that crosslink and harden by exposure to light, and thermosetting adhesives that crosslink and harden by heating.

Examples of the aforementioned light-curing adhesives and thermosetting adhesives include those containing monomers, oligomers, or polymers such as acrylic acid, epoxy resin, urethane acrylate, epoxy acrylate, silicone acrylate, or polyester acrylate as curing components, and containing photopolymerization initiators or thermal polymerization initiators.

Among the above, acrylic adhesive polymers can be obtained, for example, by pre-synthesizing a (meth)acrylic polymer having functional groups within its molecule (hereinafter referred to as a functional group-containing (meth)acrylic polymer), and then reacting this polymer with a compound having a functional group reactive with the functional group and a free radical polymerizable unsaturated bond within its molecule (hereinafter referred to as a functional group-containing unsaturated compound).

The aforementioned functional group-containing (meth)acrylic polymers are obtained by copolymerizing an alkyl acrylate and/or alkyl methacrylate, typically with an alkyl group carbon number ranging from 2 to 18, with a functional group-containing monomer and, if desired, other modifying monomers, using conventional methods. The weight-average molecular weight of the aforementioned functional group-containing (meth)acrylic polymers is typically approximately 200,000 to 2,000,000.

Examples of the above-mentioned monomers containing functional groups include: monomers containing carboxyl groups such as acrylic acid and methacrylic acid; monomers containing hydroxyl groups such as hydroxyethyl acrylate and hydroxyethyl methacrylate; monomers containing epoxy groups such as glycidyl acrylate and glycidyl methacrylate; monomers containing isocyanate groups such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate; and monomers containing amino groups such as aminoethyl acrylate and aminoethyl methacrylate.

Examples of the above-mentioned other copolymerizable modifying monomers include various monomers used in general (meth)acrylic polymers, such as vinyl acetate, acrylonitrile, and styrene.

As the functional group-containing unsaturated compound to be reacted with the functional group-containing (meth)acrylic polymer, the same monomer as the functional group-containing monomer can be used, depending on the functional group of the functional group-containing (meth)acrylic polymer. For example, when the functional group of the functional group-containing (meth)acrylic polymer is a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer can be used. When the functional group is a hydroxyl group, an isocyanate group-containing monomer can be used. When the functional group is an epoxy group, a carboxyl group-containing monomer or an amide group-containing monomer such as acrylamide can be used. When the functional group is an amino group, an epoxy group-containing monomer can be used.

Examples of the photopolymerization initiator include those activated by irradiation with light having a wavelength of 250 to 800 nm. Examples of such photopolymerization initiators include acetophenone derivatives such as methoxyacetophenone, benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether, ketone derivatives such as benzyl dimethyl ketal and acetophenone diethyl ketal, phosphine oxide derivatives, bis(η5-cyclopentadienyl)titaniumocene derivatives, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthrone, dimethylthioxanthrone, diethylthioxanthrone, α-hydroxycyclohexylphenyl ketone, and 2-hydroxymethylphenylpropane. These photopolymerization initiators can be used alone or in combination of two or more.

The above-mentioned thermal polymerization initiator can be exemplified by: those that decompose due to heat and generate active free radicals that polymerize and harden. Specifically, for example, tert-butylperoxy-2-ethyl hexanoate, bis(4-methylbenzyl) peroxide, benzoyl peroxide, 1,1-bis(tert-hexylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(4,4-bis-(tert-butylperoxy)cyclohexyl)propane, tert-hexylperoxyisopropyl monocarboxylate, tert-butylperoxy acetate, 2,2-bis-(tert-butylperoxy)cyclohexane, tert-butylperoxy)butane, 4,4-bis-(tert-butylperoxy)pentanoic acid n-butyl ester, di-tert-butylperoxy, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, bis(2-tert-butylperoxyisopropyl)benzene, tert-butylisopropylbenzene peroxide, di-tert-butyl 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, diisopropylbenzene hydroperoxide, etc.

Among these thermal polymerization initiators, commercially available products are not particularly limited. Preferred examples include PERBUTYL O, NYPER BMT, NYPER BW, PERHEXA HC, PERHEXA C, PERTETRA A, PERHEXYL I, PERBUTYL A, PERHEXA 22, PERHEXA V, PERHEXYL D, PERCUMYL D, PERHEXA 25B, PERBUTYL P, PERBUTYL C, PERHEXYNE 25B, and PERCUMYL P (all manufactured by NOF Corporation), and Perkadox 12XL25 (manufactured by Kayaku Nouryon). These thermal polymerization initiators may be used alone or in combination of two or more.

Generally speaking, the oligomer or monomer serving as the curing component has a molecular weight of 10,000 or less and contains 1 to 40 free-radically polymerizable unsaturated bonds within the molecule. From the perspective of three-dimensional network formation, the number of free-radically polymerizable unsaturated bonds is preferably 2 or more.

Examples of oligomers or monomers serving as the curing component include trihydroxymethylpropane triacrylate, tetrahydroxymethylmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, or the same methacrylates as those mentioned above. Other examples include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylates, urethane acrylates, and the same methacrylates as those mentioned above. These polyfunctional oligomers or monomers may be used alone or in combination.

The temporary fixing material (B) may also contain various thermal crosslinking agents such as acrylic polymers without unsaturated double bonds, isocyanate compounds, melamine compounds, epoxides, release agents, plasticizers, resins, surfactants, waxes, and microparticle fillers, depending on the intended content.

For the temporary fixing material (B), from the perspective of adjusting the peeling strength from the support (A) and/or the workpiece (C), it is preferable to use a release agent.

There are no particular limitations on the release agent, as long as it exhibits a general release effect. Examples include hydrocarbon compounds, silicone compounds, fluorine compounds, and polyethylene wax, carnauba wax, octadecanoic acid, and stearic acid, all known release agents for plastics. Silicone and fluorine compounds are preferred, and silicone and fluorine compounds containing functional groups capable of crosslinking with curing adhesives are even more preferred.

Polysilicon oxide, in particular, exhibits excellent heat resistance. Even after treatments accompanied by heat exceeding 200°C, it prevents the adhesive from charring and leaking into the bonded substrate during peeling, making it easier to peel. Because polysilicon oxide has functional groups that can crosslink with the aforementioned curable adhesive, it chemically reacts with light or heat, becoming incorporated into the adhesive. Therefore, polysilicon oxide does not adhere to the bonded substrate and cause contamination. Furthermore, the incorporation of polysilicon oxide prevents residual adhesive from forming on semiconductor chips.

Other release agents include plasticizers. Plasticizers are generally not limited to any type of plasticizer as long as they reduce the adhesion of the adhesive to the substrate. Examples include trimellitic acid esters, pyromellitic acid esters, phthalic acid esters, and adipic acid esters.

There is no specific limit on the amount of release agent added; the amount can be appropriately determined to achieve the desired release effect. On the other hand, to avoid significantly impairing the adhesive properties of the temporary fixing material (B), the amount added should be controlled to avoid excess. For example, a typical amount is 0.1 to 5 parts by mass (preferably 0.1 to 3 parts by mass, and even more preferably 0.1 to 1 part by mass) per 100 parts by mass of the temporary fixing material (B). Adjust the amount based on the desired release force.

If a plasticizer is added, the standard dosage is usually 5 to 50 parts by weight (preferably 10 to 50 parts by weight, and more preferably 20 to 40 parts by weight). Adjust the dosage based on the peeling force.

In this embodiment, this plasma agent can be used alone or in combination.

The thickness of the temporary fixing material (B) is not particularly limited. The preferred lower limit is 5μm, and the preferred upper limit is 250μm. The more preferred lower limit of the thickness of the temporary fixing material (B) is 10μm, and the more preferred upper limit is 200μm. If the thickness of the temporary fixing material (B) is within this range, it can absorb irregularities in the workpiece (C) and provide sufficient strength to temporarily secure it to the support (A). When the temporary fixing material (B) is peeled off, the peeling force can be easily adjusted within an appropriate range.

The temporary fixing material (B) can be a single layer or a multi-layered structure.

In the case of a multi-layered structure, it is preferable to have a layer (adhesive layer) that is adhesive to the workpiece (C) side and the support (A) side. In this case, the adhesive layer ( _B1 ) on one side can be configured to have adequate peel strength with the support (A), while the adhesive layer ( _B2 ) on the other side can be configured to have adequate peel strength with the workpiece (C). In this case, the adhesive layer ( _B1 ) contacting the support (A) and the adhesive layer ( _B2 ) contacting the workpiece (C) preferably have different compositions. In this case, the interface between the adhesive layer (B ₁ ) and the adhesive layer (B ₂ ) may have a layered structure in the general sense in which the composition changes discontinuously, or may have a so-called inclined structure in which the composition changes continuously.

The adhesive layer (B ₁ ) contacting the support (A) and the adhesive layer (B ₂ ) contacting the workpiece (C) can be directly laminated, but preferably, they are laminated on both sides through the base film (B ₀ ), so-called double-sided adhesive tape. In this aspect, the adhesive layer ( _B1 ) can be designed from the perspective of optimizing the peel strength between it and the support (A), the adhesive layer ( _B2 ) can be designed from the perspective of optimizing the peel strength between it and the workpiece (C), and the base film ( _B0 ) can be designed from the perspective of the mechanical strength and workability of the entire temporary fixing material (B) and the entire laminate (D). Therefore, it is particularly advantageous from the perspective of optimizing the performance of the temporary fixing material (B).

Figure 5 shows an example of a laminate (D) using a temporary fixing material (B) composed of an adhesive layer ( _B1 ), a base film ( _B0 ), and an adhesive layer ( _B2 ). In the figure, 11 represents the support (A), 20 represents the adhesive layer ( _B1 ) on the support (A) side, 19 represents the base film ( _B0 ), 18 represents the adhesive layer ( _B2 ) on the workpiece (C) side, and 13 represents the workpiece (C).

The material of the substrate film ( _B0 ) is not particularly limited, but preferably a plastic film is used, for example, a film, sheet, sheet having a mesh structure, sheet having open pores, etc. made of acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, urethane, polyetheretherketone (PEEK), liquid crystal polymer (LCP), polyimide, etc.

[Workpiece(C)]

There is no particular limitation on the workpiece (C) to be processed by the method of the present invention, and any workpiece that can be processed in step (2) of the present invention can be used. Among them, due to reasons such as thinness and fragility, it is necessary to pay attention to the operation during processing, so the method of the present invention is suitable for processing workpieces that need to be temporarily fixed (temporarily fixed). The thinness and fragility of the workpiece here often occur in the steps (1) and/or (2) described later. For example, the method of the present invention is suitable for processing workpieces whose thickness temporarily becomes thinner during processing, thereby hindering operation. As for the case of temporary thinning, there are cases where processing starts with a thin object, where a workpiece with a predetermined thickness is thinned during the process, and where a workpiece that has already been thinned is further processed. The thickness of the temporarily thinned workpiece (C) is typically 1 to 200 μm.

For example, a semiconductor wafer with a completed functional layer is temporarily mounted on a carrier with the functional layer as the carrier side. The surface opposite the functional layer (the back side) is then thinned. Ion implantation, annealing, and electrode formation are performed on the back side before the wafer is separated from the carrier. In this case, the semiconductor wafer in these steps corresponds to the workpiece (C).

For example, a flexible film is temporarily fixed to a carrier, circuit formation or electronic device mounting is performed on the flexible film, and then the flexible film is separated from the carrier. In this case, the flexible film in this step corresponds to the workpiece (C).

Alternatively, this method can also be used to temporarily secure a group of devices, such as chips, that are not necessarily thin, to a temporary securing material (B) formed on a support (A), sealing the entire structure to form a molded wafer or panel, which is then separated from the support. In this method, the workpiece (C) corresponds to the group of devices, such as chips, sealed wafers, and panels. Because these are easily damaged, temporary securing is performed.

As described above, the workpiece (C) processed in the present invention also includes those whose status changes during the manufacturing process.

As described above, the workpiece (C) processed by the present invention is not particularly limited. More specific examples include, in the case of semiconductor wafers, resin-coated copper foil, prepreg, thin multilayer circuit boards, flexible circuit boards, film substrates with organic electroluminescent (EL) or LEDs formed thereon, thin display components, lens arrays, or semiconductor wafers. Examples include silicon wafers, compound semiconductor wafers made of SiC, AlSb, AlAs, AlN, AlP, BN, BP, BAs, GaSb, GaAs, GaN, GaP, InSb, InAs, InN, or InP, crystal wafers, sapphire, glass, encapsulated wafers, and angular encapsulated panels.

Silicon wafers or compound semiconductor wafers can also be doped.

Alternatively, a combination of lamination, coating, sputtering, evaporation, etching, chemical vapor deposition (CVD), physical vapor deposition (PVD), resist coating/patterning, reflow, plasma treatment, chip bonding, wire bonding, and resin encapsulation can be repeated multiple times on the temporary fixing material (B) formed on the support (A) to form the workpiece (C). The thickness of the workpiece (C) in this case is not particularly limited, but is typically 1μm to 2000μm. Examples of the workpiece (C) formed on the temporary fixing material (B) include thin multi-layer circuit boards, component-embedded substrates, redistribution layers, thin film substrates with organic electroluminescent (EL) or LEDs, mold array packages, mold wafers, and mold panels.

Electrical/electronic functional layers can also be formed on or within the wafer workpiece (C). Examples of suitable functional layers include electronic circuits, capacitors, transistors, resistors, electrodes, optical elements, MEMS, etc., and other micro-components are also possible.

The surfaces of these functional layers may also have structures formed from one of the following materials, typically electrodes. Examples of materials for these functional layers include silicon, polysilicon, silicon dioxide, silicon (oxy)nitride, metals (such as copper, aluminum, gold, tungsten, and tantalum), low-k dielectrics, polymer dielectrics, and various metal nitrides and metal silicides. The surface of the workpiece (C) on the side where the device is formed may also have protruding structures such as solder bumps, metal bars, and pillars.

[Step (1)]

The workpiece processing method of the present invention comprises the following steps: (1) laminating the above-mentioned support body (A), temporary fixing material (B), and the workpiece (C) located on the side of the temporary fixing material (B) opposite to the support body (A).

An example of the state after step (1) is shown in Figure 6. In the figure, 11 represents a support body (A), 12 represents a temporary fixing material (B), and 13 represents a workpiece (C).

The workpiece (C) is fixed to the support plate (A) by a temporary fixing material (B), which makes it easier to operate the workpiece (C) during processing in the subsequent step (2) and prevents bending and damage.

The order in which the support (A), temporary fixing material (B), and workpiece (C) are stacked is not particularly limited; these layers can be stacked together or sequentially. As mentioned above, the stacking process may also include forming the workpiece (C) on the temporary fixing material (B).

When the temporary fixing material (B) is supplied in the form of a liquid curing adhesive, the liquid curing adhesive can be applied to either or both of the workpiece (C) and the support (A) by spin coating, etc., to form the temporary fixing material (B) or a precursor of the temporary fixing material (B), and then a laminate can be produced.

When providing a temporary fixing material (B) or a precursor to the temporary fixing material (B) in the form of a solid film, the bonding strength to the support is generally set to be lower than that to the workpiece. Therefore, from the perspective of preventing peeling during operation, it is best to first adhere the film to the workpiece (C) and then layer the support (A).

Furthermore, when lamination is performed under normal pressure and the laminate is formed only under reduced pressure, it is preferable to first attach the film-like temporary fixing material to the support (A) and then to the workpiece (C) in order to better absorb the unevenness of the workpiece such as the wafer.

When the temporary fixing material (B) or the material before the temporary fixing material (B) contains a hardening adhesive component, the adhesive can also be hardened in step (1) to form the temporary fixing material (B). The hardening of the adhesive is performed by irradiating the hardening adhesive component with light or heating it to crosslink and harden the hardening adhesive component.

The chemical resistance of the hardening adhesive component that is crosslinked and hardened by light or heat is dramatically improved. Even if, for example, the surface of the workpiece (C) that is not in contact with the temporary fixing material (B) is treated with a chemical solution in step (2), the dissolution of the adhesive in the chemical solution can be suppressed. In addition, the elastic modulus of the hardening adhesive component that has been crosslinked and hardened increases, so it is less likely to undergo adhesion even at high temperatures and is easier to peel off.

Thus, in this embodiment, in step (2), whether the workpiece (C) is subjected to heat treatment, machining treatment, and/or wet treatment, sufficient bonding force can be maintained during the workpiece (C) treatment. Furthermore, after the workpiece (C) treatment step is completed, the workpiece (C) can be peeled off from the temporary fixing material (B) in step (3) without damaging the workpiece (C) or leaving any adhesive residue.

For example, when the above-mentioned light-curing adhesive component that crosslinks and cures by irradiation includes a polymer having unsaturated double bonds such as vinyl groups in its side chains and a photopolymerization initiator that is activated at a wavelength of 250 to 800 nm, it is preferred that such a light-curing adhesive component be irradiated at an illuminance of 5 mW or more, more preferably at an illuminance of 10 mW or more, further preferably at an illuminance of 20 mW or more, and particularly preferably at an illuminance of 50 mW or more. Furthermore, irradiation is preferably performed at a cumulative illuminance of 300 mJ or more, more preferably at a cumulative illuminance of 500 mJ or more and 10,000 mJ or less, further preferably at a cumulative illuminance of 500 mJ or more and 7,500 mJ or less, and particularly preferably at a cumulative illuminance of 1,000 mJ or more and 5,000 mJ or less.

For example, if a thermosetting adhesive component that crosslinks and hardens by heating is used as the temporary fixing material (B) or a precursor to the temporary fixing material (B), and contains a polymer having unsaturated double bonds such as vinyl groups in its side chains and a thermal polymerization initiator that is activated by heating at approximately 50 to 200°C, the thermosetting adhesive component can be crosslinked and hardened by heating at approximately 50 to 200°C for 10 to 60 minutes.

As described above, when the temporary fixing material (B) is formed by hardening the pre-dried material, it can be laminated with the support (A) or workpiece (C) after hardening, or it can be hardened after lamination, or it can be laminated in a semi-hardened state and then finally hardened.

[Step (2)]

The workpiece processing method of the present invention further comprises the step (2) of subjecting the workpiece (C) after step (1) to at least one treatment selected from heat treatment, machining treatment, wet treatment and laser processing treatment.

The above step (2) also includes TSV processing, which is used to form a structure stacked with TSV-processed semiconductor chips.

Examples of the aforementioned heat treatments (including those involving heat generation, the same shall apply hereinafter) include, but are not limited to, sputtering, evaporation, etching, chemical vapor deposition (CVD), physical vapor deposition (PVD), photoresist coating/patterning, thermal lamination of resin composition films, thermal curing of resin compositions, thermal drying of resin compositions, baking of resin compositions, thermal reflow, resin sealing, plasma treatment, wafer bonding, wire bonding, flip-chip bonding, and surface-activated direct bonding.

In the workpiece processing method of the present invention, the above-mentioned steps can be appropriately handled even in a temperature range of 100°C, especially above 150°C.

The aforementioned mechanical processing typically involves wafer grinding, lapping, drilling, and cutting, but is not limited to these processes and also includes singulation.

When grinding or polishing a workpiece (C) with electrodes formed on its surface, the surface (backside) without electrodes is ground or polished. The thickness of the workpiece (C) after this backside grinding/polishing varies depending on the electronic device in which the resulting electronic device will be used, but is typically set to between 1 μm and 200 μm, preferably between 5 μm and 100 μm, and more preferably between 5 μm and 50 μm. This thinning of the resulting electronic device can contribute to the miniaturization of the electronic device in which it is used.

In this embodiment, when grinding/polishing a workpiece (C), by laminating the temporary fixture (B) and the rigid support (A), the workpiece (C) can be ground with superior processing accuracy. Furthermore, after grinding, the workpiece (C) can be further processed without damaging it, or it can be easily separated from the support (A) and temporary fixture (B).

The aforementioned wet treatments include coating processes such as spin coating, inkjet, and screen printing, polishing processes such as CMP, and processes using acids, alkalis, or organic solvents. Examples include, but are not limited to, coating processes such as electroplating and electroless plating, wet etching processes using hydrofluoric acid, tetramethylammonium hydroxide (TMAH), photoresist stripping processes using N-methyl-2-pyrrolidone, monoethanolamine, DMSO, and cleaning processes using concentrated sulfuric acid, ammonia, and hydrogen peroxide.

Examples of the laser processing include, but are not limited to, annealing, drilling, circuit formation by direct writing, and processing prior to separation from the support.

In the workpiece processing method of the present invention, before the step (3) described later, dicing tape can also be attached to the processing surface of the workpiece such as the wafer after the above processing. By attaching the dicing tape in advance, the support body (A) and the temporary fixing material (B) can be peeled off in step (3) and then cut quickly.

In the present invention, although the support body (A) is separated from the temporary fixing material (B) in step (3), the pre-stripping treatment can also be performed in advance in step (2).

Specifically, laser treatment or solvent-induced swelling and dissolution of the temporary fixing material (B) can be appropriately employed before mechanical stripping. However, from the perspective of simplifying the device and improving costs, it is preferable not to perform such treatments.

In this specification, the laminate having the workpiece (C) after step (2) is also referred to as the laminate (D).

[Step (3)]

The workpiece processing method of the present invention further comprises a step (3) of separating the processed workpiece (C) from the laminate (D).

Separating the workpiece (C) from the laminate (D) is preferably accomplished by separating the support member (A) from the laminate (D) and then removing the temporary fixing material (B) remaining on the workpiece (C). In this embodiment, the generally rigid support member (A) has already been separated from the laminate (D) when the temporary fixing material (B) remaining on the workpiece (C) is removed. Therefore, the workpiece (C) can be separated from the temporary fixing material (B) without applying excessive stress to the workpiece (C), thereby reducing the risk of damaging functional layers formed on the workpiece (C).

There is no particular limitation on the method of separating the support body (A) from the temporary fixing material (B), but mechanical separation is preferred.

The separation between the support (A) and the temporary fixing material (B) and the separation between the temporary fixing material (B) and the workpiece (C) can both be performed by mechanical peeling, or one of them can be performed by a method other than mechanical peeling.

In the workpiece processing method of the present invention, by achieving the aforementioned peel strength ratio P ₂ /P ₁ of 1.1 or greater, peeling between the support (A) and the temporary fixing material (B) is relatively easy. Therefore, the support (A) can be stably and completely peeled from the laminate (D) using a relatively simple process such as mechanical peeling. This effectively suppresses peeling at the unintended interface between the temporary fixing material (B) and the workpiece (C), thereby reducing the risk of damage to functional layers formed on the workpiece (C).

In the laminate (D) consisting of the support (A)/temporary fixing material (B)/workpiece (C) separated in step (3), the angle formed by each peeled layer is maintained at 10°, and the ratio P2/P1 of the "10° peeling strength _P1 between the support (A)/temporary fixing material (B)" and the "10° peeling strength _P2 between the temporary fixing material ( _B )/workpiece (C) _" measured is 1.1 or more. The 10° peel strength _P1 between the support (A) and the temporary fixing material (B) and the 10° peel strength _P2 between the temporary fixing material (B) and the workpiece (C) are measured after a process similar to step (2) described below. For example, if a heat history of 150 to 200°C is applied in step (2), the values are after the heat history is applied.

According to the workpiece processing method of the present invention, by setting the peeling strength ratio P ₂ /P ₁ to 1.1 or higher, the support body (A) can be stably peeled from the temporary fixing material (B) and covering the entire surface of the laminate (D) using a relatively simple process such as mechanical peeling.

This effectively prevents peeling at the unintended interface between the temporary fixing material (B) and the workpiece (C), thereby reducing the risk of damaging the functional layer formed on the workpiece (C).

Furthermore, since this effectively prevents the temporary fixing material (B) from being partially retained on the support (A) or damaged on the workpiece (C), the risk of damage caused by uneven stress on the workpiece (C) or the support (A) is also reduced.

The 10° peel strength ( _P1) between the support (A) and temporary fixing material (B) and the 10° peel strength (P2 ₎ between the temporary fixing material (B) and the workpiece (C) are the force (N/mm) required per unit width of the peeled portion to peel while maintaining the angle between the peeled layers (support (A) and temporary fixing material (B), or temporary fixing material (B) and workpiece (C)) at 10°.

That is, the 10° peel strength _P1 between the support (A) and the temporary fixing material (B) and the 10° peel strength _P2 between the temporary fixing material (B) and the workpiece (C) can be determined by the following method: Under the conditions shown in Figure 3 or a condition based thereon, peeling is performed between 11 support members (A) and 12 temporary fixing materials (B) or between 12 temporary fixing materials (B) and 13 workpieces (C), measuring the force required for peeling and dividing it by the width of the peeled portion. More specifically, the measurement can be performed using the following method.

The support (A) or the workpiece (C) is usually rigid or brittle. In the state of the laminate (D) formed by the support (A)/temporary fixing material (B)/workpiece (C), the angle formed by the peeled layers is usually difficult to maintain at 10°. Therefore, when measuring the 10° peel strength _P1 between the support (A)/temporary fixing material (B), the 10° peel strength _P1 measurement specimen without the workpiece (C) can be used (Figure 3 (a), (c)). When measuring the 10° peel strength _P2 between the temporary fixing material (B) and the workpiece (C), the 10° peel strength P2 without the support (A) can be used. _2. Measurement The sample was measured (Figure 3(b), (d)).

In the former case, when the temporary fixing material (B) has a base film ( _B0 ), the support (A) and the temporary fixing material (B) having the base film ( _B0 ) constitute a sample for measuring the 10° peel strength _P1 and the measurement is performed (Figure 3(a)). When the temporary fixing material (B) does not have a base film and is only an adhesive layer, a polyimide film or the like is used as the backing of the adhesive layer to constitute a sample for measuring the 10° peel strength _P1 and the measurement is performed (Figure 3(c)).

In the latter case, when the temporary fixing material (B) has a base film ( _B0 ), the temporary fixing material (B) having the base film ( _B0 ) and the workpiece (C) constitute a sample for measuring the 10° peel strength _P2 and the measurement is performed (Figure 3(b)). When the temporary fixing material (B) does not have a base film and is only an adhesive layer, a polyimide film or the like is used as the backing of the adhesive layer to constitute a sample for measuring the 10° peel strength _P2 and the measurement is performed (Figure 3(d)).

The peel strength ratio P ₂ /P ₁ is preferably 1.1 or greater, particularly preferably 1.3 or greater.

There is no particular upper limit to the above-mentioned peeling strength ratio _P2 / _P1. However, from the perspective of properly peeling the workpiece (C) from the temporary fixing material (B), it is expected that the peeling strength _P2 between the temporary fixing material (B)/workpiece (C) will not be too large. From the perspective of stably performing the processing in step (2), especially the machining processing, it is expected that the 10° peeling strength _P1 between the support body (A)/temporary fixing material (B) will not be too small. Therefore, the above-mentioned peeling strength ratio _P2 / _P1 is preferably 30 or less, more preferably 15 or less, and particularly preferably 7 or less.

In step (3), from the perspective of stably peeling the support body (A) from the temporary fixing material (B) and covering the entire surface of the laminate (D) by a simple process such as mechanical peeling without applying excessive stress to the workpiece (C), the 10° peeling strength _P1 between the support body (A) and the temporary fixing material (B) is preferably less than 10N/25mm.

The 10° peel strength _P1 between the support body (A) and the temporary fixing material (B) is more preferably 8N/25mm or less, and particularly preferably 7N/25mm or less.

From the perspective of stably carrying out the processing in step (2), especially the machining processing, the 10° peeling strength _P1 between the support body (A) and the temporary fixing material (B) is preferably 1N/25mm or more, and more preferably 2N/25mm or more.

In step (3), the temporary fixing material (B) is preferably separated from the workpiece (C) by separating the support body (A) from the laminate (D) and then removing the temporary fixing material (B) remaining on the workpiece (C). From this point of view, the 10° peeling strength _P2 between the temporary fixing material (B) and the workpiece (C) is preferably less than 30N/25mm, and more preferably less than 20N/25mm.

From the perspective of stably carrying out the processing in step (2), especially the machining processing, the 10° peeling strength _P2 between the temporary fixing material (B) and the workpiece (C) is preferably 2N/25mm or more, and more preferably 3N/25mm or more.

There is no particular limitation on the means for adjusting the 10° peel strength P ₁ , 10° peel strength P ₂ , and peel strength ratio P ₂ /P ₁ . For example, they can be appropriately increased or decreased by conventional means in the art. More specifically, the value of the peel strength can be appropriately increased or decreased by adjusting the composition and manufacturing process of each layer, the manufacturing process of the laminate (D), etc. For example, by increasing the amount of adhesive or bonding agent used in the temporary fixing material (B), the 10° peel strength _P1 or 10° peel strength _P2 can be increased, and by adding a release agent to the temporary fixing material (B), the 10° peel strength _P1 or 10° peel strength _P2 can be reduced.

The mechanical peeling method in this embodiment is not particularly limited, and commercially available devices can be used for peeling. For example, peeling is preferably performed using the method shown in Figure 1.

In this method, the workpiece (C) side of the laminate (D) is secured to a chuck base (not shown) using cutting tape, and then the support (A) is held by a retaining mechanism (not shown).

Slide the remover 16 into the interface between the support body 11 (A) and the temporary fixing material 12 (B). Apply an upward force to the end of the support body 11 (A), forming a peeling interface between the support body 11 (A) and the temporary fixing material 12 (B), which serves as the peeling starting point (Figure 1(b)).

While applying pressure through the retaining mechanism to bend the support body (A), the peeling interface is expanded to allow the peeling to proceed (Figure 1(c)).

If the peeling interface expands and forms across the entire surface between the support member 11 (A) and the temporary fixing member 12 (B), the support member 11 (A) will peel off from the temporary fixing member 12 (B).

Examples of commercially available devices include the SUSS XBC Gen, the EVG EVG805, and the TWH-SR series from TAZMO Co., Ltd.

At this point, according to the present invention, unintended peeling of the interface between the temporary fixing material 12 (B) and the workpiece 13 (C) can be effectively suppressed. Therefore, the temporary fixing material 12 (B) can effectively protect the functional layers formed on the workpiece 13 (C), thereby reducing the risk of damage to these functional layers (Figure 2(a)).

In conventional techniques, prior to the peeling process between the support member (A) 11 and the temporary fixing material (B) 12, peeling may sometimes occur at the interface between the temporary fixing material (B) 12 and the workpiece (C) 13 (Figure 2(b)). As a result, electronic circuits formed on the workpiece (C) 13 may be damaged during the peeling process or during subsequent manufacturing processes where they still require protection from the temporary fixing material (B).

Furthermore, in conventional techniques, there are cases where a portion of the temporary fixing material (B) 12 remains on the support body (A) 11, or a portion of the temporary fixing material (B) 12 on the workpiece (C) 13 is damaged, preventing the complete removal of the support body (A) (Figure 2(c)). As a result, uneven stress may be applied to the workpiece (C) 13 or the support body (A), leading to such damage.

In order to remove the temporary fixing material (B) remaining on the workpiece (C), a solvent can also be used to dissolve it.

The present invention solves these problems with prior art techniques by preventing delamination at unintended interfaces and non-uniform delamination, or at least significantly reducing the frequency of such delamination. This prevents damage to the functional layers formed on workpieces such as wafers, and enables the execution of a large number and/or multiple steps on the workpiece with high productivity and yield.

After being processed by the workpiece processing method of the present invention, a workpiece such as a wafer can be subjected to subsequent steps to produce a final product. Once a functional layer has been formed on the workpiece, further steps such as dicing, bonding, packaging, and sealing, typically used in the manufacture of electronic devices such as semiconductor elements, can be performed to produce the final product.

[Example]

The present invention is described in detail below. Furthermore, the present invention is not limited in any sense by the following embodiments.

The evaluation of physical properties and characteristics in the Examples/Comparative Examples was performed using the following methods.

(1) Mechanical releasability

After applying the predetermined heat cycle shown in Table 1 to the fabricated laminate (D), the workpiece (C) 13 was placed face-down at room temperature and secured to a dicing tape 14 attached to a ring frame 15. The dicing tape 14 was secured with a vacuum chuck (Figure 1(a)). Debonding was intentionally initiated at the interface between the support (A) 11 and the temporary fixing material (B) 12. As shown in Figure 1, a remover 16 was slid into the interface between the support (A) 11 and the temporary fixing material (B). An upward force of typically approximately 120 N was applied to the end of the support (A), thereby forming a debonding interface between the support (A) 11 and the temporary fixing material (B) 12 (Figure 1(b)).

Next, pressure is applied to the resulting peeling interface to expand it, thereby peeling the 11 support (A) (Figure 1(c)). The peeling properties are evaluated using the following criteria.

○: The entire surface of the support (A)/temporary fixing material (B) interface can be intentionally peeled off, and the workpiece (C) is not damaged.

×: Unexpected separation occurs at the interface between the temporary fixing material (B) and the workpiece (C).

(2) Removability of temporary fixing material (B) from workpiece (C)

After the mechanical releasability evaluation described above, the workpiece (C)/temporary fixing material (B) laminate (13) was fixed to the dicing tape (14) attached to the ring frame (15). Adhesive tape (17) was applied to the entire surface of the temporary fixing material (B). The dicing tape (14) was secured with a vacuum chuck, and the temporary fixing material (B) was peeled off at a peeling angle of 90° and a peeling speed of 5 mm/s. Releasability was evaluated using the following criteria.

○: The temporary fixing material (B) can be completely removed from the workpiece (C) without damaging the workpiece (C).

×: The temporary fixing material (B) cannot be separated from the workpiece (C).

(3) 10° peel strength _P1 (peel strength between support and temporary fixing material)

(3-1) When a base film (B ₀ ) is used as a temporary fixing material

The adhesive layer (B ₁ ) on the side contacting the support (A) (20) is laminated on the base film (B ₀ 19) to prepare a P ₁ measurement sample.

(3-2) When the base film (B ₀ ) is not used as a temporary fixing material

Prepare 21 polyimide films (double-sided plasma treatment, 38 μm thickness, manufactured by DU PONT-Toray Co., Ltd., trade name: Kapton (registered trademark) 150EN-A) and layer the same material as the temporary fixing material 12 on top to make the _P1 measurement sample.

(3-3) Measurement

The _P1 measurement sample prepared in (3-1) or (3-2) above was cut into 2.5 cm × 5 cm and rolled back and forth once with a 2 kg roller to attach the _P1 measurement sample's 20 adhesive layer ( _B1 ) or the same material side as the 12 temporary fixing material to the attachment side of the 11 support body (A) cut into 3 cm × 6 cm. Next, using the pretreatment in step (1) of each embodiment and comparative example as the default condition, the prepared support body (A)/ _P1 measurement sample laminate was heated at 140°C for 30 minutes. Then, using step (2) as the default condition, the predetermined thermal history shown in Table 1 was applied, and then the sample was placed at 22.5±1°C and a relative humidity of 50±10% for one week. After the sample was cooled, the peel strength _P1 was measured under these temperature and humidity conditions using VPA-S (manufactured by Kyowa Interface Science Co., Ltd.) at a tensile speed of 300 mm/min and a peel angle of 10° (Figure 3(a) or (c)).

(4) 10° peel strength _P2 (peel strength between temporary fixing material and workpiece)

(4-1) When a base film ( _B0 ) is used as a temporary fixing material

An adhesive layer (B ₂ ) is deposited on the substrate film (B ₀ ) 19 on the side that contacts the workpiece (C) 18 to prepare a P ₂ measurement sample.

(4-2) When the base film ( _B0 ) is not used as a temporary fixing material

Prepare 21 polyimide films (double-sided plasma treatment, 38 μm thickness, manufactured by DU PONT-Toray Co., Ltd., trade name: Kapton (registered trademark) 150EN-A) and layer the same material as 12 temporary fixing materials on top to make a sample for _P2 measurement.

(4-3) Measurement

The _P2 measurement sample prepared in (4-1) or (4-2) above was cut into 2.5 cm x 5 cm and rolled back and forth once with a 2 kg roller to attach the adhesive layer 18 ( _B2 ) or the same material side as the temporary fixing material 12 of the _P2 measurement sample to the attachment side of the workpiece (C) cut into 3 cm x 6 cm. Next, using the pre-treatment in step (1) of each embodiment and comparative example as the default condition, the prepared workpiece (C)/ _P2 measurement sample laminate was heated at 140°C for 30 minutes. Then, using step (2) as the default condition, the predetermined thermal history shown in Table 1 was applied, and the sample was placed at 22.5±1°C and a relative humidity of 50±10% for one week. After the sample was cooled, the peel strength _P2 was measured under these temperature and humidity conditions using VPA-S (manufactured by Kyowa Interface Science Co., Ltd.) at a tensile speed of 300 mm/min and a peel angle of 10 degrees (Figure 3(b) or (d)).

The details of the materials and sources used in the Examples/Comparative Examples are as follows.

[Support (A) and workpiece (C)]

Use the following glass or Si for either the support (A) or the workpiece (C).

.Glass

Use a borosilicate heat-resistant glass substrate with an outer diameter of 300 or 200 mm and a thickness of 700 μm for silicon back grinding.

．Si

Use Si mirror wafers with an outer diameter of 300 or 200 mm and a thickness of 750 μm.

[Resin used to form the temporary fixing material (B)]

．(Meth)acrylic resin solution N:

In a solvent composed of 65 parts by mass of toluene and 50 parts by mass of ethyl acetate, 49 parts by mass of ethyl acrylate, 20 parts by mass of 2-ethylhexyl acrylate, 21 parts by mass of methyl acrylate, 10 parts by mass of glycidyl methacrylate, and 0.5 parts by mass of a benzoyl peroxide-based polymerization initiator were reacted at 80°C for 10 hours. After the reaction, the resulting solution was cooled. To the cooled solution were added 25 parts by mass of xylene, 5 parts by mass of acrylic acid, and 0.5 parts by mass of tetradecyldimethylbenzylammonium chloride. The mixture was reacted at 85°C for 32 hours while blowing air into the solution to obtain (meth)acrylic resin solution N.

．Polysilicone modified (meth) acrylic resin solution NS

To 270 parts by mass of the (meth)acrylic resin solution N, 0.3 parts by mass of a carboxyl-modified organopolysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22-3710) was added and the mixture was reacted at 60°C for 7 days to obtain a silicone-modified (meth)acrylic resin solution NS.

．(Meth)acrylic resin solution L

Use (meth)acrylic adhesive (Bind Seramu SA591, manufactured by Mitsui Chemicals, Inc.).

．(Meth)acrylic latex H

Using 0.5 parts by mass of ammonium persulfate as a polymerization initiator, emulsion polymerization was carried out in deionized water at 70°C with 63 parts by mass of 2-ethylhexyl acrylate, 21 parts by mass of n-butyl acrylate, 9 parts by mass of methyl methacrylate, 3 parts by mass of 2-hydroxyethyl methacrylate, 2 parts by mass of methacrylic acid, 1 part by mass of acrylamide, 1 part by mass of polytetramethylene glycol diacrylate (manufactured by NOF Corporation, trade name: ADT-250), and 2 parts by mass of an aqueous solution of polyoxyethylene nonylpropylene phenyl ether ammonium sulfate (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon HS-1025). After completion of the polymerization, the pH was adjusted to 7.0 with aqueous ammonia to obtain (meth)acrylic resin latex H with a solids content of 56.5% by mass.

．(Meth)acrylic resin latex B

Using 0.5 parts by mass of 4,4'-azobis-4-cyanovaleric acid (manufactured by Otsuka Chemical Co., Ltd., trade name: ACVA) as a polymerization initiator, emulsion polymerization was carried out in deionized water at 70°C with 74 parts by mass of n-butyl acrylate, 14 parts by mass of methyl methacrylate, 9 parts by mass of 2-hydroxyethyl methacrylate, 2 parts by mass of methacrylic acid, 1 part by mass of acrylamide, and 3 parts by mass of HS-1025. After completion of polymerization, the pH was adjusted to 7.0 with aqueous ammonia to obtain (meth)acrylic resin emulsion B with a solids content of 42.5% by mass.

．(Meth)acrylic resin latex A

Using 0.65 parts by mass of ACVA as a polymerization initiator, emulsion polymerization was carried out in deionized water at 70°C with 63 parts by mass of 2-ethylhexyl acrylate, 18 parts by mass of n-butyl acrylate, 12 parts by mass of methyl methacrylate, 3 parts by mass of 2-hydroxyethyl methacrylate, 2 parts by mass of methacrylic acid, 1 part by mass of acrylamide, 1 part by mass of ADT-250, and 2 parts by mass of Aqualon HS-1025. After completion of the polymerization, the pH was adjusted to 7.0 with aqueous ammonia to obtain (meth)acrylic resin emulsion A with a solids content of 42.5% by mass.

．(Meth)acrylic latex S

Using 0.5 parts by mass of ACVA as a polymerization initiator, 47 parts by mass of n-butyl acrylate, 22 parts by mass of methyl methacrylate, 9 parts by mass of 2-hydroxyethyl methacrylate, 15 parts by mass of methacrylic acid, 8 parts by mass of acrylamide, and 0.2 parts by mass of Aqualon HS-1025 were emulsion polymerized in deionized water at 70°C to produce (meth)acrylic resin latex S with a solid content of 40% by mass.

[Base film B ₀ ]

．PEN film

A polyethylene naphthalate film (double-sided corona treatment, thickness: 50 μm, manufactured by Toyobo Film Solutions Co., Ltd., Teonex Q83) was used.

．PET film

A biaxially oriented polyethylene terephthalate film (double-sided corona treatment, thickness 38 μm, manufactured by Toray Industries, Ltd., Lumirror S10) was used.

(Example 1)

To 250 parts by mass of the (meth)acrylic resin solution L, 2.84 parts by mass of HDI isocyanurate (manufactured by Tosoh Co., Ltd., trade name: Coronate HX), 50 parts by mass of dipentatriol penta/hexaacrylate (manufactured by Toagosei Co., Ltd., trade name: ARONIX M-402), 2.0 parts by mass of polysilicone diacrylate (manufactured by DAICEL-ALLNEX Co., Ltd., trade name: Ebecryl 350), and 2 parts by mass of Perkadox 12XL25 (manufactured by Kayaku Nouryon Co., Ltd.) were added to obtain a coating liquid for the adhesive layer ( _B1 ) on the support (A) side. This was used as the adhesive layer ( _B1 ) on the support (A) side. This coating liquid was applied to substrate _B0 (PEN film) and dried at 100°C for 10 minutes to form a 25μm thick adhesive resin layer. Next, a silicone release-treated polyethylene terephthalate film (separator) was laminated to form an adhesive layer ( _B1 )/substrate ( _B0 ) laminate on the separator-attached support (A) side.

An adhesive coating liquid was prepared by mixing 42.6 parts by weight of (meth)acrylic resin latex H, 57.4 parts by weight of (meth)acrylic resin latex B, 0.4 parts by weight of dimethylethanolamine, 3.4 parts by weight of an epoxy compound (trade name: Ex-1610, manufactured by Nagase ChemteX Co., _Ltd. ), 13 parts by weight of butyl carbinol, and 20 parts by weight of pure water. This coating liquid was applied to a silicone release-treated polyethylene terephthalate film (separator) and dried at 120°C for 3 minutes to form a 13 μm thick adhesive resin layer. This was then bonded to the substrate ( _{B0) side of the adhesive layer (B1 )} /substrate ( _B0 ) laminate, creating a temporary fixing material (B) precursor with a separator, consisting of a three-layer adhesive layer ( _B1 )/substrate ( _B0 )/adhesive layer ( _B2 ) prior to heat treatment. The separators on both sides of this three-layer structure were removed, and the support (A) and workpiece (C) listed in Table 1 were laminated using a vacuum laminator and heated at 140°C for 30 minutes, creating a laminate (D) consisting of the support (A)/temporary fixing material (B)/workpiece (C) in this order. The results of the evaluation of the mechanical peelability and removability of the laminate (D) are shown in Table 1.

Separately, laminates of adhesive layer ( _B1 )/substrate ( _B0 ) and adhesive layer ( _B2 )/substrate ( _B0 ) were prepared (using the same coating conditions). The 10° peel strengths _P1 and _P2 were measured using the above method. The results are shown in Table 1.

(Example 2)

To 270 parts by mass of (meth)acrylic resin solution N, 0.5 parts by mass of HDI isocyanurate (manufactured by Tosoh Co., Ltd., trade name: Coronate HX), 12 parts by mass of dipentatriol penta/hexaacrylate (manufactured by Toagosei Co., Ltd., trade name: ARONIX M-400), 1.5 parts by mass of polysilicone diacrylate (manufactured by DAICEL-ALLNEX Co., Ltd., trade name: Ebecryl 350), and 2 parts by mass of Perkadox 12XL25 (manufactured by Kayaku Nouryon Co., Ltd.) were added to obtain a coating liquid for the adhesive layer ( _B1 ) on the support body (A) side. This was used as the adhesive layer ( _B1 ) on the support body (A) side. The coating liquid was applied to a silicone release-treated polyethylene terephthalate film (separator) and dried at 100°C for 10 minutes to form a 100 μm thick adhesive resin layer. A substrate B ₀ (PET film) was then laminated to form an adhesive layer (B ₁ )/substrate (B ₀ ) laminate on the separator-attached support (A) side.

Next, the coating liquid for the adhesive layer ( _B2 ) on the workpiece (C) side in Example 1 was applied to a silicone release-treated polyethylene terephthalate film (separator), dried at 120°C for 3 minutes to form a 6μm thick adhesive resin layer, which was then attached to the substrate (B0) side of the adhesive layer ( _B1 )/substrate ( _B0 ) laminate, thereby producing a temporary fixing material ( _B ) precursor before heat treatment, consisting of a three-layer structure of adhesive layer ( _B1 )/substrate ( _B0 )/adhesive layer ( _B2 ) with a separator.

The separators used on both sides of the three-layer structure were peeled off. The support (A) and workpiece (C) listed in Table 1 were vacuum laminated and heated at 140°C for 30 minutes to produce a laminate (D) consisting of the support (A), temporary fixing material (B), and workpiece (C) in this order. The results of the mechanical peelability and removability evaluation of the laminate (D) are shown in Table 1.

Separately, laminates of adhesive layer ( _B1 )/substrate ( _B0 ) and adhesive layer ( _B2 )/substrate ( _B0 ) were prepared (using the same coating conditions). The 10° peel strengths _P1 and _P2 were measured using the above method. The results are shown in Table 1.

(Example 3)

To 269 parts by mass of silicone-modified (meth)acrylic resin solution NS, 1.0 parts by mass of HDI isocyanurate (manufactured by Tosoh Co., Ltd., trade name: Coronate HX) and 2 parts by mass of Perkadox 12XL25 (manufactured by Kayaku Nouryon Co., Ltd.) were added to prepare an adhesive coating liquid for the temporary fixing material (B). This coating liquid was applied to a silicone release-treated polyethylene terephthalate film (separator) and then dried at 100°C for 10 minutes to form an adhesive resin layer with a thickness of 100 μm. Next, a silicone-release-treated polyethylene terephthalate film (separator) was laminated to create a temporary fixing material (B) precursor (with separators attached on both sides) before heat treatment. The separators on both sides were peeled off, and the support plate (A) and workpiece (C) listed in Table 1 were laminated using a vacuum lamination machine. The laminate was heated at 140°C for 30 minutes to create a laminate (D) consisting of support (A)/temporary fixing material (B)/workpiece (C) in this order. The results of the mechanical peelability and removability evaluation of the laminate (D) are shown in Table 1.

The 10° peel strengths P ₁ and P ₂ were measured using the above method (without using a base film (B ₀ ) as the temporary fixing material). The measurement results are shown in Table 1.

(Example 4)

The coating liquid for the adhesive layer ( _B1 ) on the support (A) side of Example 1 was applied to a silicone release-treated polyethylene terephthalate film (separator) and dried at 100°C for 10 minutes to form a 31 μm thick adhesive resin layer. A _substrate (PET film) was then laminated to form a laminate of adhesive layer ( _B1 )/substrate ( _B0 ) on the support (A) side with a separator.

Next, 100 parts by weight of (meth)acrylic resin emulsion A, 0.7 parts by weight of (meth)acrylic resin emulsion S, 0.3 parts by weight of dimethylethanolamine, 5 parts by weight of an epoxy compound (trade name: Ex-614, manufactured by Nagase ChemteX Co., Ltd.), 9 parts by weight of butyl alcohol, and 12 parts by weight of pure water were mixed to prepare an adhesive coating liquid. This was used as the adhesive layer ( _B2 ) on the workpiece (C) side. This coating liquid was applied to a silicone release-treated polyethylene terephthalate film (separator) and dried at 120°C for 3 minutes to form a 20 μm thick adhesive resin layer. Next, it was attached to the substrate ( _{B0) side of the adhesive layer (B1 )} /substrate ( _B0 ) laminate, thereby producing a temporary fixing material (B) precursor prior to heat treatment, comprising a three-layer structure of adhesive layer ( _B1 )/substrate ( _B0 )/adhesive layer ( _B2 ) with separators. The separators used on both sides of this three-layer structure were removed, and the support (A) and workpiece (C) listed in Table 1 were laminated using a vacuum laminator and heated at 140°C for 30 minutes to produce a laminate (D) consisting of support (A)/temporary fixing material (B)/workpiece (C) in this order. The results of the evaluation of the mechanical peelability and removability of the laminate (D) are shown in Table 1.

Separately, laminates of adhesive layer ( _B1 )/substrate ( _B0 ) and adhesive layer ( _B2 )/substrate ( _B0 ) were prepared (using the same coating conditions). The 10° peel strengths _P1 and _P2 were measured using the above method. The results are shown in Table 1.

(Comparative example 1)

To 269 parts by weight of silicone-modified (meth)acrylic resin solution N, 0.1 parts by weight of HDI isocyanurate (manufactured by Tosoh Co., Ltd., trade name: Coronate HX), 6 parts by weight of pentaerythritol tri/tetraacrylate (manufactured by Toagosei Co., Ltd., trade name: M-450), and 2 parts by weight of Perkadox 12XL25 (manufactured by Kayaku Nouryon Co., Ltd.) were added to prepare an adhesive coating liquid for the temporary fixing material (B). This coating liquid was applied to a silicone release-treated polyethylene terephthalate film (separator) and then dried at 100°C for 10 minutes to form a 50 μm thick adhesive resin layer. Next, a silicone release-treated polyethylene terephthalate film (separator) was laminated to create a temporary fixing material (B) precursor (double-sided separator) before heat treatment. The separators on both sides were peeled off, and the support plate (A) and workpiece (C) listed in Table 1 were stacked using a vacuum lamination machine. The stack was heated at 140°C for 30 minutes to create a laminate (D) consisting of support (A)/temporary fixing material (B)/workpiece (C) in this order. The results of the mechanical peelability and removability evaluation of the laminate (D) are shown in Table 1.

The 10° peel strengths P ₁ and P ₂ were measured using the above method (without using the base film (B ₀ ) as the temporary fixing material). The measurement results are shown in Table 1.

[Table 1]

[Industrial Availability]

The workpiece processing method of the present invention enables the execution of a large number and/or multiple steps on wafers or other workpieces with high productivity and yield without damaging electronic components such as functional layers formed on the wafers or other workpieces. Therefore, it significantly contributes to improving the productivity of electronic devices and has high applicability in various industries, including the semiconductor manufacturing industry, the electronic component industry, the electrical and electronics industry using electronic components, the transportation equipment industry, the information and communications industry, and the precision equipment industry.

11: Support body (A)

12: Temporary fixing material (B)

13: Workpiece (C)

Claims (12)

A method for processing a workpiece comprises the following steps: step (1) laminating a support body (A), a temporary fixing material (B), and a workpiece (C) located on the side of the temporary fixing material (B) opposite to the support body (A); step (2) subjecting the workpiece (C) to at least one treatment selected from heat treatment, mechanical processing, wet processing, and laser processing; and step (3) separating the workpiece (C) from the laminate (D) having the treated workpiece (C); wherein the thickness of the workpiece (C) is at least temporarily set to be greater than 1 μm and less than 200 μm, and the angle formed by each peeled layer is maintained at 10°, and the ratio P 2 /P _{1 of the "peeling strength P 1} between the support (A)/temporary fixing material (B) at 10°" and the "peeling strength _{P 2} between the temporary fixing material (B)/workpiece (C) at 10°" measured is greater than _1.1 . A workpiece processing method as described in claim 1, wherein the peeling strength _P1 is less than 10N/25mm. The workpiece processing method as described in claim 1, wherein the temporary fixing material (B) has a different composition in the adhesive layer connected to the support body (A) and the adhesive layer connected to the workpiece (C). A method for processing a workpiece as described in any one of claims 1 to 3 comprises separating a support body (A) from a temporary fixing material (B) and then removing the temporary fixing material (B) remaining on the workpiece (C), thereby achieving separation of the workpiece (C) from the laminate (D). A workpiece processing method as described in claim 4, wherein the temporary fixing material (B) and the supporting body (A) are separated by mechanical peeling. The workpiece processing method as described in any one of claims 1 to 3, wherein the temporary fixing material (B) contains a hardening adhesive component. The workpiece processing method according to any one of claims 1 to 3, wherein the temporary fixing material (B) contains a release agent. The workpiece processing method according to any one of claims 1 to 3, wherein the temporary fixing material (B) is formed by bonding the material on both sides of the base film (B ₀ ). A method for processing a workpiece as described in any one of claims 1 to 3, wherein the thickness of the workpiece (C) after processing in step (2) is greater than 1 μm and less than 200 μm. A method for manufacturing an electronic device comprises the steps of implementing the workpiece processing method described in any one of claims 1 to 9. The method for manufacturing an electronic device as described in claim 10, wherein the electronic device has a structure formed by stacking semiconductor chips. A laminate (D) is formed by laminating a support (A), a temporary fixing material (B), and a workpiece (C) located on the side of the temporary fixing material (B) opposite to the support (A), wherein the thickness of the workpiece (C) is at least temporarily not less than 1 μm and not more than 200 μm, and the ratio (P 2 /P 1) of the "10° peeling strength P ₁ between the support (A)/temporary fixing material (B)" and the "10° peeling strength P ₂ between the temporary fixing material (B)/workpiece (C)" measured while maintaining the angle formed by the peeled layers at ₁₀ ° is not _less than 1.1.