TWI905141B - Methods for manufacturing protective film forming wafers, wafers with protective films, and laminates. - Google Patents

Abstract

The protective film forming sheet of this embodiment has a support sheet and a curable resin film disposed on one side of the support sheet; the curable resin film is used to adhere to the surface of the wafer with protruding electrodes and to be cured, thereby forming a protective film on the surface of the wafer; the support sheet has a first region in the first side where the curable resin film is disposed, and a second region surrounding the first region where the curable resin film is not disposed.

Description

Methods for manufacturing protective film forming wafers, wafers with protective films, and laminates.

This invention relates to a protective film forming sheet, a method for manufacturing a chip with a protective film, and a laminate. This application claims priority based on Japanese Patent Application No. 2020-031717, filed on February 27, 2020, the contents of which are incorporated herein by reference.

Previously, when mounting multi-pin LSI (Large Scale Integration) packages used in MPUs (Micro Processing Units) or gate arrays on printed wiring boards, the following flip-chip mounting method was used: As a chip, a chip with protruding electrodes (also called "bumps") formed on the interconnect pads made of eutectic solder, high-temperature solder, metal, etc. was used. By flip-chip bonding, these protruding electrodes faced and contacted the corresponding terminals on the chip mounting substrate, and fusion/diffusion bonding was performed.

The chip used in this fabrication method is obtained by monolithically forming a wafer with protruding electrodes on a circuit surface. Furthermore, during this process, a curable resin film is typically attached to the circuit surface to protect the circuit surface and the protruding electrodes, and the resin film is then cured to form a protective film on the circuit surface. The curable resin film is used as a protective film forming sheet for a laminate with a support sheet. In the protective film forming sheet, a curable resin film is provided on the entire surface of one side of the support sheet.

For example, a curable resin film in a protective film forming die is heated and then attached to the electrical surface of a wafer. The curable resin film and support sheet are then cut along the outer periphery of the wafer. The areas of the protective film forming die not attached to the wafer are removed, and the support sheet is peeled off. The curable resin film is then cured, thereby forming a protective film on the electrical surface of the wafer. The wafer is then diced to form wafers, and the protective film is cut along the outer periphery of the wafer, thereby obtaining a wafer with a protective film on its electrical surface (see Patent 1). [Prior Art Documents] [Patent Documents]

[Patent Document 1] International Publication No. 2017/077957.

[The problem the invention aims to solve]

For this type of curing resin film, a relatively softer one is used so that when the curing resin film is attached to the wafer, it can make sufficient contact with the surface of the wafer with protruding electrodes (electrical surface). However, when the curing resin film, which becomes soft by heating, is attached to the wafer, the following problems arise.

When a heated, cured resin film is attached to the surface of a wafer with protruding electrodes, pressure is applied to the cured resin film. The cured resin film is typically used as a protective film layer in the deposition of a support sheet, and this pressure is transmitted to the cured resin film via the support sheet. Consequently, the cured resin film flows radially outward from the wafer due to this pressure, that is, from the area attached to the wafer towards the area not attached to the wafer. Furthermore, in areas where the hardened resin film is not attached to the wafer, especially in the vicinity of the wafer, the hardened resin film flows orthogonally to the radial direction of the wafer and toward the wafer, resulting in a thicker hardened resin film than in areas where it is attached to the wafer.

Thus, the thickened areas of the hardened resin film are redundant and will directly adhere to the side of the wafer or any part of the wafer manufacturing apparatus during any manufacturing process of the protective film-coated wafer, contaminating these parts.

The purpose of this invention is to provide a protective film forming sheet, comprising a resin film for attaching to and curing a surface of a wafer with protruding electrodes, thereby forming a protective film on the aforementioned surface; and, when the aforementioned protective film forming sheet is used to attach the resin film to the surface of the wafer with protruding electrodes, it can suppress the formation of areas of increased thickness due to the flow of the aforementioned resin film. [Means for Solving the Problem]

The present invention comprises the following: [1]. A protective film forming sheet comprising a support sheet and a curable resin film disposed on one side of the support sheet; wherein the curable resin film is used to adhere to and cure the surface of a wafer having protruding electrodes, thereby forming a protective film on the aforementioned surface of the wafer; the support sheet has, on the aforementioned side, a first region having the aforementioned curable resin film and a second region surrounding the first region but not having the aforementioned curable resin film.

[2]. The protective film forming sheet as described in [1], wherein a specimen of the aforementioned curable resin film with a diameter of 25 mm and a thickness of 1 mm is strained under conditions of 90°C and 1 Hz, and the storage elastic modulus of the specimen is measured, wherein the storage elastic modulus of the specimen when the strain of the specimen is 1% is set as Gc1, and the storage elastic modulus of the specimen when the strain of the specimen is 300% is set as Gc300, and the value of X calculated by the following formula: X = Gc1/Gc300 is 19 or more and less than 10000. [3]. The protective film forming sheet as described in [1] or [2], wherein the thickness of the aforementioned curable resin film is 25 μm or more. [4]. A protective film forming sheet as described in any of [1] to [3], wherein the maximum width of the aforementioned curable resin film is 140 mm to 150 mm, 190 mm to 200 mm, 290 mm to 300 mm, or 440 mm to 450 mm.

[5]. A protective film forming sheet as described in any of [1] to [4], wherein the aforementioned support sheet is circular. [6]. A protective film forming sheet as described in [5], wherein the aforementioned support sheet is an adhesive sheet, or has a jig adhesive layer along its outer periphery. [7]. A protective film forming sheet as described in any of [1] to [4], wherein the aforementioned support sheet is a peeling film. [8]. A protective film forming sheet as described in any of [1] to [7], wherein a groove is formed on the aforementioned surface of the aforementioned wafer to form a dicing portion of the aforementioned wafer.

[9]. A method for manufacturing a wafer with a protective film comprises: an attachment step, wherein a curable resin film in a protective film forming wafer as described in any one of [1] to [8] is heated and attached to a surface of a wafer having protruding electrodes; a curing step, wherein the attached curable resin film is cured, thereby forming a protective film on the aforementioned surface of the wafer; and a processing step, wherein the wafer after the formation of the protective film is diced, and the protective film is cut, thereby obtaining a wafer with a protective film, the wafer having a protective film comprising a wafer and the aforementioned protective film disposed on the diced wafer. [10]. A method for manufacturing a wafer with a protective film as described in [9], wherein the wafer used is a wafer whose area when viewed from above is equal to or greater than the area of the surface of the curable resin film facing the wafer; in the aforementioned attachment step, the entire surface of the surface of the curable resin film is attached to the aforementioned surface of the wafer.

[11]. A method for manufacturing a wafer with a protective film as described in [9] or [10], wherein a groove is formed on the aforementioned surface of the wafer to form a dicing portion of the wafer, and in the aforementioned attachment step, when the aforementioned curable resin film is attached to the aforementioned surface facing the wafer, the aforementioned curable resin film is filled into the aforementioned groove. [12]. A method for manufacturing a wafer with a protective film as described in any one of [9] to [11], wherein in the aforementioned attachment step, a roller is used to attach the aforementioned curable resin film to the aforementioned surface of the wafer. [13]. A deposit is obtained by forming a thermosetting resin film on the peeling surface of a peeling membrane, processing the thermosetting resin film and the peeling membrane together into a circular shape, and bonding the entire surface of the surface opposite to the side having the peeling membrane to the surface of a strip-shaped back abrasive belt. [14]. A laminate comprising: a peeling membrane; a thermosetting resin film disposed on a peeling treatment surface of the peeling membrane; and a back abrasive belt disposed on a surface of the thermosetting resin film opposite to the peeling membrane side; wherein the planar shape of the peeling membrane and the planar shape of the thermosetting resin film are both circular; the peeling membrane and the thermosetting resin film are arranged symmetrically at their outer peripheries in the radial direction; and the back abrasive belt is strip-shaped. [Invention Benefits]

Figure 1 is a cross-sectional view schematically illustrating the problem that the present invention seeks to solve. In the region 622 near the periphery of the area where the cured resin film 62 is not attached to the wafer 9, there is typically a region with a lower temperature than the region 621 where the cured resin film 62 is attached to the wafer 9 and the region 620 near the wafer 9 where it is not attached. This is due to the following reason: the region 621 where the cured resin film 62 is attached to the wafer 9 is heated, for example, as described later, using the heated wafer 9 as a heat source. In the aforementioned regions 621 and 620, heat is easily transferred and the temperature rises. In contrast, heat is not easily transferred to the region 622, which is far from the aforementioned periphery of the wafer 9. Consequently, the cured resin film 62 flows easily in the area 621 attached to wafer 9 and in the area 620 near wafer 9 where it is not attached. In contrast, the flowability is low in the area 622 near the periphery where the temperature of the cured resin film 62 is low, thus blocking the flow of the cured resin film 62. Therefore, as explained above, the phenomenon that the cured resin film thickness is increased in the area 620 where it is not attached to wafer 9, especially in the area 620 near wafer 9, compared to the area 621 where it is attached to wafer 9 becomes more obvious.

In contrast, by using the protective film forming sheet of this invention, when the curable resin film in the aforementioned protective film forming sheet is attached to the surface of the wafer with protruding electrodes, the area of the curable resin film not attached to the wafer is narrowed or disappears, thereby reducing the amount of flowing curable resin film and thus suppressing the formation of areas where the curable resin film thickness increases. Furthermore, in the area near the periphery of the aforementioned curable resin film, there is no area that becomes cold, thus further suppressing the formation of areas where the curable resin film thickness increases.

According to the present invention, by using such a protective film forming wafer to manufacture a protective film chip, it is possible to prevent contamination of the side of the wafer or any part of the protective film chip manufacturing apparatus due to the adhesion of excess parts of the hardened resin film.

[Protective Film Forming Sheet] One embodiment of the present invention provides a protective film forming sheet comprising: a support sheet; and a curable resin film disposed on one side of the support sheet; wherein the curable resin film is used to adhere to and cure the surface of a wafer having protruding electrodes, thereby forming a protective film on the aforementioned surface of the wafer; the support sheet has, on the aforementioned side, a first region having the aforementioned curable resin film and a second region surrounding the first region but not having the aforementioned curable resin film. The protective film forming sheet of this embodiment has the aforementioned first and second regions in the support sheet, thereby preventing areas where the cured resin film in the protective film forming sheet fails to adhere to the wafer and forms thickened areas when the cured resin film is attached to the surface of the wafer with protruding electrodes. Hereinafter, the protective film forming sheet of this embodiment will be described with reference to the drawings.

Figure 2 is a plan view schematically illustrating an example of a protective film forming sheet according to this embodiment, and Figure 3 is a cross-sectional view of the protective film forming sheet shown in Figure 2 along line I-I. In the following description, for ease of understanding of the features of the invention, some parts that are considered key components are sometimes enlarged for convenience, and the dimensional ratios of the constituent elements may not be the same as in the actual figures. In the figures following Figure 3, for constituent elements whose labels are the same as those in the previously described figures, detailed explanations are omitted.

The protective film forming sheet 1 shown here comprises: a support sheet 11; and a curable resin film 12 disposed on one side 11a of the support sheet 11. The support sheet 11 has a first region 111a on the side 11a, i.e., the side facing the curable resin film 12, where the curable resin film 12 is disposed, and a second region 112a surrounding the first region 111a but not covered by the curable resin film 12. That is, the entire area of the first region 111a in the support sheet 11 is covered by the curable resin film 12, while the entire area of the second region 112a is not covered by the curable resin film 12.

The second region 112a of one side 11a of the support piece 11 is preferably exposed (the exposed side).

The curable resin film 12 is used to adhere to and cure the surface of the wafer with protruding electrodes, thereby forming a protective film on the surface of the wafer with protruding electrodes. In this specification, "wafer" may 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 and glass.

Electrical circuits are formed on one side of these wafers. In this specification, this side of the wafer with the electrical circuits is referred to as the "electrical surface." The side of the wafer opposite to the electrical surface is referred to as the "inner surface." The side of the wafer with protruding electrodes has the same meaning as the electrical surface. Wafers are diced into chips using methods such as dicing. In this specification, similarly to the case of wafers, the side of the chip with the electrical circuits is referred to as the "electrical surface," and the side of the chip opposite to the electrical surface is referred to as the "inner surface." Bolts, pillars, or other protruding electrodes are provided on both the electrical surface of the wafer and the electrical surface of the chip. These protruding electrodes are preferably made of solder.

The support sheet 11 supports the hardened resin film 12. More specifically, the support sheet 11 can be, for example, composed solely of a substrate having this supporting function; a release film; or an adhesive sheet that can be attached to the wafer during grinding on the inner surface of the wafer. The aforementioned adhesive sheet can also have a jig such as a ring frame attached to its periphery. Furthermore, by using the support sheet 11 as the aforementioned release film, the manufacture of the protective film forming sheet, as described later, is sometimes easier.

The planar shape of the support piece 11, that is, the shape of the aforementioned surface 11a, is circular. For example, when the support piece 11 is an adhesive piece, or when it has a layer of adhesive for the jig along its outer periphery as described later, it is particularly preferable that the planar shape of the support piece 11 is circular. The reason is that the planar shape of this support piece 11 is usually consistent with the inner periphery of the jig such as the annular frame, so it is not necessary to cut the support piece 11 after it is attached to the jig such as the annular frame.

The planar shape of the hardened resin film 12, that is, the shape of the side 12a opposite to the side of the support sheet 11, is circular. Furthermore, sometimes an orientation plane or notch is provided on the wafer for the purpose of identifying or aligning the crystal orientation. Sometimes the shape of the wafer is not perfectly circular, and the hardened resin film 12 can also be set to a planar shape consistent with that shape.

When the protective film forming sheet 1 is viewed from above and downwards from the side of the curing resin film 12, the support sheet 11 and the curing resin film 12 are aligned at their centers and arranged concentrically. The maximum width of the support sheet 11, i.e., its diameter D _11, is greater than the maximum width of the curing resin film 12, i.e., its diameter D ₁₂ .

The planar shape and size of the first region 111a of the support sheet 11 are the same as those of the hardened resin film 12, and are circles with a diameter of D _12. The planar shape of the second region 112a of the support sheet 11 is an annulus with a width of (D ₁₁ - D ₁₂ )/2.

The area of the inner surface of the wafer to which the curable resin film 12 is attached (the area of the wafer with protruding electrodes when viewed from above) is preferably equal to or less than the area of the surface 12a of the curable resin film 12 opposite to the side of the support sheet 11 (the area of the first region 111a of the support sheet 11). By selecting this type of curable resin film 12, when the curable resin film 12 in the protective film forming sheet 1 is attached to the surface of the wafer with protruding electrodes, the amount of curable resin film 12 overflowing onto the second region 112a of the support sheet 11 can be further reduced. As a result, the areas where the curable resin film 12 is not attached to the wafer and forms a thickened area can be further suppressed.

The maximum width (diameter) D ₁₂ of the curable resin film 12 is preferably equal to or less than the maximum diameter (e.g., diameter) of the wafer to which the curable resin film 12 is attached. For example, wafers with a planar circular shape may have diameters of 6 inches, 8 inches, 12 inches, and 18 inches. Preferred curable resin films 12 for attaching to any of these wafers may have a maximum width (diameter) D ₁₂ of 140 mm to 150 mm, 190 mm to 200 mm, 290 mm to 300 mm, or 440 mm to 450 mm.

In the aforementioned surface 11a of the support piece 11, the width of the second region 112a ((D ₁₁ - _{D 12} )/2) is preferably 0.05 to 0.4 times, more preferably 0.07 to 0.3 times, relative to the maximum width (D ₁₂ ) of the first region 111a. By having the width of the second region 112a at or above the aforementioned lower limit, when the support piece 11 is an adhesive sheet or has the aforementioned adhesive layer for fixtures, the possibility of the hardened resin film 12 contacting the fixture can be reduced when the support piece 11 is attached to a fixture such as a ring frame. By limiting the width of the second region 112a to below the aforementioned upper limit, it is possible to prevent the area of the second region 112a from becoming too wide.

On the surface of the wafer to which the curable resin film 12 is attached, where the protruding electrodes are located, grooves can also be formed that form the wafer's dicing portions when the wafer is sliced and monolithically assembled into chips. That is, the curable resin film 12 can also be a resin film used to attach to the surface of the wafer with protruding electrodes and thus forming the grooves that constitute the wafer's dicing portions, and then cured to form a protective film on the aforementioned surface of the wafer. The aforementioned grooves are formed on the surface of the wafer with protruding electrodes in a shape corresponding to the size and shape of the target chip.

For example, by grinding the inner surface (opposite side) of a wafer with the aforementioned grooves formed on the surface having the aforementioned protruding electrodes until the aforementioned grooves appear, a wafer segmented at the aforementioned groove location is obtained. At this time, by attaching a hardening resin film 12, the aforementioned grooves are filled by the hardening resin film 12. As a result, if it becomes a state filled with the hardened material of the hardening resin film 12, that is, a protective film, after obtaining the aforementioned wafer, by cutting the aforementioned protective film between the aforementioned wafers, a wafer with a protective film can be obtained in the following form: the aforementioned wafer not only has a protective film on the surface having the aforementioned protruding electrodes, but also has a protective film on all four sides. Chips that are protected on the sides can obtain a higher level of protection from the protective film.

The support sheet 11 and the cured resin film 12 may each be composed of a single layer (monolayer) or multiple layers (two or more layers). When the support sheet 11 or the cured resin film 12 is composed of multiple layers, these multiple layers may be the same or different from each other, and there is no particular limitation on the combination of these multiple layers.

In this specification, not limited to the case of support sheet 11 and hardened resin film 12, the phrase "multiple layers may be the same or different from each other" means "all layers may be the same, all layers may be different, or only some layers may be the same". Furthermore, the phrase "multiple layers are different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other".

The thickness T ₁₂ of the curable resin film 12 is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 25 μm or more. By having T ₁₂ at or above this value, when the curable resin film 12 is attached to the surface of the wafer with protruding electrodes and the aforementioned grooves, the curable resin film 12 can fill the aforementioned grooves with a higher degree of seamlessness. In addition, it can cover the base near the electrical surface of the protruding electrodes of the wafer with a higher degree of seamlessness. That is, the curable resin film 12 is more advantageous in terms of filling the aforementioned grooves and covering the base of the protruding electrodes.

There is no particular upper limit to the thickness T ₁₂ of the cured resin film 12. For example, in order to avoid the thickness of the cured resin film 12 becoming too thick, T ₁₂ is preferably 200 μm or less, more preferably 130 μm or less, and even more preferably 80 μm or less.

In this manual, the term "thickness of the curing resin film" refers to the overall thickness of the curing resin film. For example, the term "thickness of a multi-layered curing resin film" refers to the total thickness of all the layers that make up the curing resin film.

In the protective film forming sheet 1, a test piece of a curable resin film 12 with a diameter of 25 mm and a thickness of 1 mm is strained at a temperature of 90°C and a frequency of 1 Hz. The storage elastic modulus of the test piece is measured. When the storage elastic modulus of the test piece with a strain of 1% is set as Gc1, and the storage elastic modulus of the test piece with a strain of 300% is set as Gc300, the value of X calculated by the following formula: X=Gc1/Gc300 is preferably 19 or more and less than 10000. This curable resin film 12 is soft and suitable for attaching to objects with uneven surfaces, such as wafers with protruding electrodes and wafers with the aforementioned grooves.

The aforementioned test piece is in the form of a film, and its planar shape is circular. The aforementioned test piece can also be a single-layer curable resin film 12 with a thickness of 1 mm, but for ease of manufacture, it is preferable to form a laminated film by stacking multiple single-layer curable resin films 12 with a thickness of less than 1 mm. The thicknesses of the multiple single-layer curable resin films 12 constituting the aforementioned laminated film can all be the same, or all be different, or only some can be the same; for ease of manufacture, it is preferable that they are all the same.

In this specification, not limited to the aforementioned Gc1 and Gc300, the term "storage elastic modulus of the test piece" means "the storage elastic modulus of the test piece corresponding to the strain when a test piece of a hardened resin film with a diameter of 25 mm and a thickness of 1 mm is subjected to strain at a temperature of 90°C and a frequency of 1 Hz".

When the curable resin film 12 is attached to the surface of the wafer with protruding electrodes, the upper part of the protruding electrodes protrudes through the curable resin film 12. Furthermore, the curable resin film 12 expands between the protruding electrodes in a manner that covers them, making close contact with the surface of the wafer with protruding electrodes, and covering the surface of the protruding electrodes, especially the surface near the surface of the wafer with protruding electrodes, thus filling in the base of the protruding electrodes. In this state, the residue of the curable resin film 12 is suppressed, starting from the top of the protruding electrodes. Therefore, the adhesion of the protective film 12', which is the hardened component of the hardened resin film 12, to the upper part of the protruding electrode is naturally suppressed. Furthermore, when the aforementioned groove is formed on the aforementioned surface, the degree of strain of the hardened resin film 12 differs significantly between the intermediate stage where the hardened resin film 12 begins to penetrate into the aforementioned groove and the final stage where the hardened resin film 12 covers the base of the protruding electrode and fully fills the aforementioned groove. More specifically, the strain of the hardened resin film 12 is greater in the aforementioned intermediate stage and less in the aforementioned final stage. The hardened resin film 12 uses Gc1 as the storage elastic modulus when the strain is small and Gc300 as the storage elastic modulus when the strain is large. The X value (=Gc1/Gc300) is specified to be above 19 but below 10000, with Gc1 increasing and Gc300 decreasing, thereby achieving the excellent effects described above.

Regarding improving the effect of the cured resin film 12 in coating the base of the protruding electrode, the X value is preferably 5000 or less, more preferably 2000 or less, further preferably 1000 or less, and especially preferably 500 or less; for example, it can also be any of 300 or less, 100 or less, and 70 or less. Regarding improving the effect of suppressing the presence of the cured resin film 12 on the upper part of the protruding electrode and improving the effect of the cured resin film 12 in fully filling the aforementioned groove, the X value is preferably 25 or more, more preferably 30 or more, further preferably 40 or more, and especially preferably 50 or more; for example, it can also be 60 or more.

In the hardened resin film 12, there is no particular limitation on the Gc1 value as long as it is 19 or higher but not exceeding 10,000. In terms of ease of increasing the X value, the Gc1 is preferably 1× ^10⁴ Pa to 1× ^10⁶ Pa, more preferably 3× ^10⁴ Pa to 7× ^10⁵ Pa, and even more preferably 5× ^10⁴ Pa to 5× ^10⁵ Pa.

In the cured resin film 12, there is no particular limitation on the Gc300 as long as the X value is 19 or higher but less than 10000. Regarding improving the effect of the cured resin film 12 in fully filling the aforementioned grooves, the Gc300 is preferably less than 15000 Pa, more preferably less than 10000 Pa, further preferably less than 5000 Pa, especially preferably less than 4000 Pa, and for example, less than 3500 Pa. Regarding improving the effect of the cured resin film 12 in covering the base of the protruding electrode, the Gc300 is preferably 100 Pa or higher, more preferably 500 Pa or higher, and further preferably 1000 Pa or higher.

In the hardened resin film 12, it is preferable that both Gc1 and Gc300 satisfy any of the above value ranges.

The storage elastic modulus of the cured resin film 12 is not limited to Gc1 and Gc300. For example, it can be adjusted by adjusting the components and their contents in the cured resin film 12. More specifically, for example, by using polyvinyl acetal as the polymer component (A) described later or a polymer (b) without energy line curing groups, the aforementioned Gc300 can be easily adjusted to an appropriate value, and the X value can be adjusted to an appropriate value. Furthermore, by adjusting the type or content of the additive (I) described later, the aforementioned Gc1 can be easily adjusted to an appropriate value, and the X value can be adjusted to an appropriate value. Additionally, by increasing the content of one or both of the filler (D) and additive (I) described later, the Gc1 can be easily adjusted to a larger value, resulting in a larger X value. The composition of the hardened resin film 12 will be explained separately.

The thickness of the support sheet 11 is not particularly limited, but is preferably 50 μm to 850 μm, and more preferably 75 μm to 700 μm. By having a thickness of the support sheet 11 above the aforementioned lower limit, the support sheet 11 achieves higher strength. By having a thickness of the support sheet 11 below the aforementioned upper limit, the flexibility of the support sheet 11 is improved, and its operability is further enhanced.

In this manual, the term "thickness of the support sheet" refers to the overall thickness of the support sheet. For example, the term "thickness of a multi-layered support sheet" refers to the total thickness of all the layers that make up the support sheet.

Figure 4 is a plan view schematically illustrating another example of a protective film forming sheet according to this embodiment. The protective film forming sheet 2 shown here includes: a support sheet 21; and a hardened resin film 12 disposed on one side 21a of the support sheet 21.

The support sheet 21 is a long strip, and multiple sheets of cured resin film 12 are arranged in a row along its long side. The support sheet 21 is identical to the support sheet 11 in the protective film forming sheet 1 shown in Figures 2 and 3, except for the difference in shape and size when viewed from above. For example, the thickness of the support sheet 21 is the same as that of the support sheet 11. Furthermore, the protective film forming sheet 2 is identical to the protective film forming sheet 1 shown in Figures 2 and 3, except that it has the support sheet 21 instead of the support sheet 11 and the number of cured resin films 12 is different.

The protective film forming sheet 2 is suitable for continuously attaching a hardened resin film 12 to the surface of multiple wafers with protruding electrodes.

The support sheet 21, on its side 21a, i.e., the side facing the cured resin film 12, has multiple first regions 211a on which the cured resin film 12 is disposed, and second regions 212a surrounding these first regions 211a but not on which the cured resin film 12 is disposed. That is, in the support sheet 21, the entire area of each first region 211a is covered by the cured resin film 12, while the entire area of the second region 212a is not covered by the cured resin film 12. Preferably, the second regions 212a in one side 21a of the support sheet 21 are exposed (exposed surface).

The planar shape of the support sheet 21, i.e., the shape of the aforementioned surface 21a, is rectangular, preferably strip-shaped. When viewed from above and downwards from the side of the curable resin film 12, all the curable resin films 12 are arranged at equal intervals on the support sheet 21. All the curable resin films 12 in the protective film forming sheet 2 have the same shape and size. Furthermore, in the width direction of the protective film forming sheet 2 (orthogonal to the long side direction), all the curable resin films 12 are positioned in the same way, coinciding with the center position in the width direction of the protective film forming sheet 2. The maximum width D ₂₁ of the support sheet 21 is greater than the maximum width of the curable resin film 12, i.e., the diameter D ₁₂ . Here, the width of the support piece 21 is constant along its long side, so the maximum width of the support piece 21 only refers to the width of the support piece 21.

The first region 211a of the support sheet 21 has the same planar shape and size as the hardened resin film 12, and is a circle with a diameter of D _12. The second region 212a of the support sheet 21 has a planar shape formed by removing one row from a rectangle and creating multiple circles with a diameter of D ₁₂ .

In the aforementioned surface 21a of the support piece 21, when the minimum value of the line segment connecting one point of the outer periphery of the first region 211a and one point of the outer periphery of the support piece 21 is set to _L1 , and the distance between two adjacent curable resin films 12 is set to _L2 , the smaller value between _L1 and _L2 /2 is preferably 0.03 to 0.25 times, more preferably 0.05 to 0.2 times, relative to the maximum value ( _D12 ) of the width of the aforementioned first region 211a. The aforementioned values can be appropriately adjusted, for example, to match the specifications of the device used to continuously attach the curable resin film 12 to the surface of multiple wafers with protruding electrodes. Here, it indicates that _L1 is equal to ( _D21 - _D12 )/2, but the formula for _L1 varies depending on the configuration position or size of the first region 211a in the aforementioned side 21a of the support piece 21.

The protective film forming sheet of this embodiment is not limited to the protective film forming sheets shown in Figures 2 to 4. A portion of the structure can be modified, deleted, or added to the protective film forming sheets shown in Figures 2 to 4. For example, in the protective film forming sheet 1 shown in Figure 2, as shown in Figure 5, a strip-shaped (here, annular) fixture adhesive layer 13 can be provided along the outer periphery of the support sheet 11 in the second region 112a of the aforementioned surface 11a. The fixture adhesive layer 13 is used to fix the protective film forming sheet 1 to a fixture such as a ring frame. Similarly, in the protective film forming sheet 2 shown in Figure 4, an annular fixture adhesive layer may be provided in the second region 212a of the aforementioned side 21a of the support sheet 21, for each cured resin film 12, without contacting the cured resin film 12 and surrounding the first region 211a.

For example, in the protective film forming sheet 1 shown in FIG2, when the support sheet 11 is an adhesive sheet, a jig adhesive layer (such as the jig adhesive layer 13 shown in FIG5) may be provided on the adhesive layer of the aforementioned adhesive sheet.

For example, although the planar shape of the curing resin film 12 in the protective film forming sheet 1 shown in FIG. 2 and the protective film forming sheet 2 shown in FIG. 4 is circular, the planar shape of the curing resin film is not limited to this, and may also be a non-circular shape such as a quadrilateral.

For example, in the protective film forming sheet 2 shown in Figure 4, some or all of the cured resin films 12 may be arranged at unequal intervals, or the shape and size of some or all of the cured resin films 12 may be different. In addition, the arrangement positions of some or all of the cured resin films 12 in the width direction of the protective film forming sheet 2 may also be different.

For example, in the protective film forming sheet 2 shown in Figure 4, the number of hardened resin films 12 is 3 or more, but the number of hardened resin films 12 is not limited to this.

For example, in the protective film forming sheet 1 shown in FIG. 2 or the protective film forming sheet 2 shown in FIG. 4, support sheets may be provided on both sides of the cured resin film 12 (the side facing the support sheet 11 or the support sheet 21, and the side 12a opposite to that side). As an example, in the protective film forming sheet 2 shown in FIG. 4, the support sheet 11 shown in FIG. 2 may be provided on the side 12a of the cured resin film 12 opposite to the side facing the support sheet 21. In this case, it is preferable that the support sheet 21 is a peeling film, and the support sheet 11 is an adhesive sheet, or a support sheet having the aforementioned jig adhesive layer (e.g., the jig adhesive layer 13 shown in FIG. 5). By using this type of protective film forming sheet, the continuous supply of the protective film forming sheet 1 shown in FIG. 2 becomes easier. In this type of protective film forming sheet, both the support sheet 11 and the support sheet 21 have a second region without the curing resin film 12. Typically, the support sheet 11 functions as a support sheet that has the effects of the present invention.

As an example of a protective film forming sheet of this embodiment, a laminate obtained by means of the following method can be cited: a thermosetting resin film is formed on the peeling surface of a peeling membrane; the thermosetting resin film and the peeling membrane are processed together into a circular shape; and the entire surface of the side opposite to the side having the peeling membrane is bonded to the surface of a strip-shaped back abrasive belt. The aforementioned laminate includes the laminated structure of the support sheet 21 and the thermosetting resin film 12 in the protective film forming sheet 2 shown in FIG. 4. In this laminate, the back abrasive belt of the support sheet 21 has a second region, but the peeling membrane does not have a second region.

As an example of a protective film forming sheet of this embodiment, a laminate can be described as follows: the laminate comprises: a peeling membrane; a thermosetting resin film disposed on a peeling treatment surface of the peeling membrane; and a back abrasive belt disposed on a surface of the thermosetting resin film opposite to the peeling membrane side; wherein the planar shape of the peeling membrane and the planar shape of the thermosetting resin film are both circular; the peeling membrane and the thermosetting resin film are arranged in a consistent manner at their radially adjacent peripheral positions; and the back abrasive belt is strip-shaped. In this laminate, the back abrasive belt corresponding to the support sheet has a second region, but the peeling membrane does not have a second region.

As an example of a protective film forming sheet of this embodiment, a protective film forming sheet can be described as follows: the protective film forming sheet comprises: a support sheet; and a curable resin film disposed on one side of the support sheet; wherein the curable resin film is used to adhere to and cure the surface of the wafer having protruding electrodes, thereby forming a protective film on the aforementioned surface of the wafer; the support sheet has the aforementioned curable resin film disposed on the aforementioned side. The first region of the resin film, and the second region surrounding the first region and not having the aforementioned curable resin film (excluding the deposit obtained by means of: forming a thermosetting resin film on the peeling treatment surface of the peeling film, processing the thermosetting resin film and the peeling film together into a circle, and attaching the entire surface of the thermosetting resin film having the side opposite to the side of the peeling film to the surface of the strip-shaped back abrasive belt).

As another example of a protective film forming sheet according to this embodiment, a protective film forming sheet can be described as follows: the protective film forming sheet comprises: a support sheet; and a curable resin film disposed on one side of the support sheet; wherein the curable resin film is a resin film for attaching to and curing the surface of a wafer with protruding electrodes, thereby forming a protective film on the aforementioned surface of the wafer; the support sheet has, on the aforementioned side, a first region in which the curable resin film is disposed, and a region surrounding the first region without the curable resin film. The second region of the resin film (excluding the following deposit: the deposit having: a peeling film; a thermosetting resin film disposed on a peeling treatment surface of the peeling film; and a back abrasive belt disposed on a surface of the thermosetting resin film opposite to the peeling film side; and the planar shape of the peeling film and the planar shape of the thermosetting resin film are both circular, the peeling film and the thermosetting resin film are arranged in a consistent manner in the radial direction of the outer periphery of these films, and the back abrasive belt is strip-shaped).

The aforementioned curable resin film constituting the protective film forming sheet of this embodiment can be either thermosetting or energy-curable, or it can have both thermosetting and energy-curable 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 using high-pressure mercury lamps, fusion lamps, xenon lamps, black lights, or LED (Light Emitting Diode) lamps as ultraviolet sources. Electron beams can be emitted by irradiating particles generated using electron beam accelerators, etc. In this manual, the term "energy line hardening property" refers to the property of hardening by irradiation of energy lines.

The aforementioned curable resin film can be formed using a curable resin film forming composition containing the constituent material of the curable resin film. For example, the aforementioned curable resin film can be formed by applying the aforementioned curable resin film forming composition to the object surface of the curable resin film and drying it as needed. The ratio of the content of the components that do not vaporize at room temperature in the curable resin film forming composition is usually the same as the ratio of the content of the aforementioned components in the curable resin film. In this specification, "room temperature" means a temperature that is neither particularly cold nor hot, that is, a normal temperature, such as temperatures from 15°C to 25°C.

The application of the aforementioned components for forming a hardened resin film can be carried out using known methods, such as: methods using air knife coating machines, scraper coating machines, rod coating machines, gravure coating machines, roller coating machines, roller knife coating machines, curtain coating machines, mold coating machines, blade coating machines, screen coating machines, Mayer rod coating machines, touch coating machines, and other various coating machines.

Regardless of whether the aforementioned curable resin film is thermosetting or energy-curable, the drying conditions for the aforementioned composition for forming a curable resin film are not particularly limited. However, when the composition for forming a curable resin film contains the solvent described later, heat drying is preferred. Furthermore, curable resin film forming compositions containing solvent are preferably heat-dried at 70°C to 130°C for 10 seconds to 5 minutes. Specifically, thermosetting resin film forming compositions are preferably heat-dried in a manner that prevents the composition itself and the thermosetting resin film formed by the composition from undergoing thermosetting.

Examples of thermosetting resin films include those containing a polymer component (A) and a thermosetting component (B). Examples of thermosetting resin film forming components include, for example, thermosetting resin film forming component (III) containing a polymer component (A) and a thermosetting component (B) (sometimes referred to as "Component (III)" in this specification).

From the perspective of easily adjusting the aforementioned Gc300 and X value to an appropriate value, the aforementioned polymer component (A) is preferably polyvinyl acetal. As for the aforementioned polyvinyl acetal in polymer component (A), known alternatives can be listed. Among these, preferred polyvinyl acetals include, for example, polyvinyl formaldehyde and polyvinyl butyral, with polyvinyl butyral being more preferred.

Examples of the aforementioned thermosetting component (B) include: epoxy thermosetting resins composed of epoxy resin (B1) and thermosetting agent (B2); polyimide resins; unsaturated polyester resins, etc.

The thermosetting resin film and the aforementioned component (III) may further contain other components not equivalent to either the polymer component (A) or the thermosetting component (B). Examples of such other components include: curing accelerators (C), fillers (D), coupling agents (E), crosslinking agents (F), energy-line curing resins (G), photopolymerization initiators (H), additives (I), solvents, etc.

By adjusting the content of the aforementioned filler (D), the aforementioned X value can be adjusted more easily. The filler (D) can be either an organic or inorganic filler, preferably an inorganic filler. Preferred inorganic fillers include, for example: powders of silicon dioxide, alumina, talc, calcium carbonate, titanium dioxide, iron oxide, silicon carbide, boron nitride, etc.; beads formed by spheroidizing these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; glass fibers, etc. Among these, silicon dioxide or alumina is preferred as the inorganic filler.

From the perspective of further improving the filling performance of thermosetting resin film in wafer trenches, the ratio of the content of filler (D) in thermosetting resin film and the aforementioned composition (III) to the total content of all components other than solvent is preferably 5% to 45% by mass, more preferably 5% to 40% by mass, and even more preferably 5% to 30% by mass.

Examples of the aforementioned additive (I) include, for example, colorants, plasticizers, antistatic agents, antioxidants, gas-absorbing agents, rheology control agents, surfactants, and polysiloxane oils. Preferred additives (I) for easily adjusting the X value by appropriately adjusting the aforementioned Gc1 include, for example, rheology control agents, surfactants, and polysiloxane oils.

More specifically, examples of rheology control agents include: polyhydroxycarboxylic acid esters, polycarboxylic acids, and polyamide resins. Examples of surfactants include: modified silicates and acrylic polymers. Examples of polysiloxane oils include: aralkyl-modified polysiloxane oils and modified polydimethylsiloxanes. Modifying groups include: aralkyl groups; polar groups such as hydroxyl groups; and groups with unsaturated bonds such as vinyl and phenyl groups.

From the perspective that the aforementioned X value is easier to adjust, the ratio of the content of additive (I) to the total content of all components other than solvent in the thermosetting resin film and the aforementioned component (III) is preferably 0.5% to 10% by mass, more preferably 0.5% to 7% by mass, and even more preferably 0.5% to 5% by mass.

The thermosetting resin film and the aforementioned component (III) contain polymer component (A), thermosetting component (B), curing accelerator (C), filler (D), coupling agent (E), crosslinking agent (F), energy line curing resin (G), photopolymerization initiator (H), additive (I), solvent, etc. Each component may be only one type or may be two or more types. In the case of two or more types, the combination and ratio of these components can be arbitrarily selected.

Examples of energy-curing resin films include those containing energy-curing component (a). Examples of components for forming energy-curing resin films include components (IV) containing energy-curing component (a) (sometimes referred to simply as "component (IV)" in this specification).

The energy-line curable resin film and the aforementioned component (IV) may further contain other components not equivalent to the energy-line curable component (a). Examples of such other components include: polymers (b) lacking energy-line curable groups, thermosetting components, fillers, coupling agents, crosslinking agents, photopolymerization initiators, additives, solvents, etc.

From the perspective of easily adjusting the above-mentioned Gc300 to an appropriate value and adjusting the X value to an appropriate value, the polymer (b) without energy line hardening groups is preferably polyvinyl acetal.

The thermosetting components, fillers, coupling agents, crosslinking agents, photopolymerization initiators, additives, and solvents in the energy line curing resin film and the aforementioned composition (IV) are the same as those in the thermosetting components (B), fillers (D), coupling agents (E), crosslinking agents (F), photopolymerization initiators (H), additives (I), and solvents in the aforementioned thermosetting resin film and the aforementioned composition (III).

The energy-curing resin film and the aforementioned components (IV) contain energy-curing components (a), polymers (b) without energy-curing groups, thermosetting components, fillers, coupling agents, crosslinking agents, photopolymerization initiators, additives, solvents, etc. Each component may be only one type or two or more types. In the case of two or more types, the combination and ratio of these components can be arbitrarily selected.

The aforementioned support sheet constituting the protective film forming sheet of this embodiment is also known. For example, various resins can be listed as constituent materials of the support sheet composed solely of the aforementioned substrate. Examples of the aforementioned resins include: polyethylene; polyolefins other than polyethylene such as polypropylene; ethylene-based copolymers (polymers obtained using ethylene as a monomer); vinyl chloride-based resins (resins obtained using vinyl chloride as a monomer); polystyrene; polycyclic olefins; polyesters; 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; polyurethane; polyetherketone, etc. Furthermore, examples of the aforementioned resins include, for instance, polymer alloys such as mixtures of the aforementioned polyester and resins other than the polyester. Also, examples of the aforementioned resins include, for instance, crosslinked resins formed by crosslinking one or more of the aforementioned resins as described above; modified resins such as ionic polymers formed using one or more of the aforementioned resins as described above.

In this manual, the term "(meth)acrylic acid" is intended to include both "acrylic acid" and "methacrylic acid". Similarly, the term "(meth)acrylate" includes both "acrylate" and "methacrylate".

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

From the perspective of versatility, and in the manufacturing method of the protective film described later, when the curable resin film in the state of having a support sheet is thermo-cured, it can impart heat resistance to the support sheet. In addition, from the perspective of easily preventing wafer warping, the aforementioned resin is preferably a polyester such as polyethylene terephthalate or polybutylene terephthalate; or a polypropylene. In this case, the support sheet (substrate) can be a single layer or a multilayer structure, as long as it has one or more layers selected from the group consisting of a polyester layer and a polypropylene film layer.

A support sheet consisting solely of the aforementioned substrate and containing resin can be manufactured by molding a resin composition containing the aforementioned resin.

The release film used as the aforementioned support sheet can also be a release film composed of a material with release properties or having a peelable layer, thereby facilitating the peeling of the hardened resin film. The aforementioned release film can be identical to the support sheet composed solely of the aforementioned substrate, except that it is composed of a material with release properties or has a peelable layer on the substrate.

Materials with release properties, such as fluoropolymers, can be cited as examples. Layers with easy-to-peel properties, such as those composed of polysiloxane-based or alkyd-based release agents, can be cited as examples.

The aforementioned adhesive sheet, serving as the support sheet, typically comprises a film-like or sheet-like substrate and an adhesive layer. An intermediate layer may also be provided between the substrate and the adhesive layer to embed the protruding electrodes. The aforementioned substrate in the adhesive sheet can be, for example, the same as that used in a support sheet composed solely of the aforementioned substrate. The adhesive contained in the aforementioned adhesive layer in the adhesive sheet can be, for example, acrylic adhesives, rubber adhesives, or carbamate adhesives. The adhesive layer's adhesion can also be reduced by irradiation with an energy beam. Components contained in the aforementioned intermediate layer of the adhesive sheet may include, for example, a cured form of (meth)acrylate aminocarbamate compound, and thermoplastic polyolefin resins (thermoplastic resins having constituent units derived from olefins).

The support sheet can also be a back-side polishing tape. That is, the inner-side polishing of the wafer, as described later, can also be performed with the support sheet attached to the hardened resin film. Alternatively, the support sheet can also be used during inner-side polishing of the wafer without being attached to the hardened resin film. For example, in manufacturing method 2 of the wafer manufacturing method with a protective film described later, the support sheet can be removed before the hardening step. In this case, during inner-side polishing of the wafer, a back-side polishing tape is attached to the hardened resin film. Therefore, the support sheet does not necessarily need to possess the characteristics required to be a back-side polishing tape. Furthermore, even if the support sheet deforms due to heating during the curing process along with the curing resin film, or if the support sheet has an adhesive layer that softens due to heating, these problems can be avoided by removing the support sheet with these properties before the curing process.

The adhesive layer for the aforementioned fixture may have a single-layer structure containing adhesive components, or it may have a multi-layer structure, which includes a sheet serving as the core material and layers disposed on both sides of the sheet and containing adhesive components. Examples of layers containing adhesive components include those similar to the adhesive layer in the aforementioned adhesive sheet.

[Manufacturing Method of Protective Film Forming Sheet] The protective film forming sheet of this embodiment can be manufactured by sequentially laminating the aforementioned layers (support sheet, curing resin film, fixture adhesive layer, etc.) in a corresponding positional relationship. The formation method of each layer is as described above. Furthermore, the shape of each layer can be adjusted at any time before or after its lamination, as needed.

For example, during the manufacture of the aforementioned protective film forming sheet, the aforementioned curable resin film forming composition is applied to one side of the aforementioned support sheet and dried as needed, thereby depositing the aforementioned curable resin film on the support sheet. Alternatively, during the manufacture of the aforementioned protective film forming sheet, a peeling membrane is used as the support sheet, and the aforementioned curable resin film forming composition is applied to one side of the peeling membrane (the peeling treatment surface) and dried as needed, thereby forming the aforementioned curable resin film on the peeling membrane, thus obtaining the protective film forming sheet. When using a release membrane as a support sheet, it is preferable to form a hardened resin film on approximately the entire surface of the release membrane, then cut the hardened resin film into a shape (e.g., a circle) that is the same as the shape envisioned for the first region of the release membrane, and remove excess hardened resin film in a manner that creates a second region, thereby easily obtaining a protective film forming sheet. Alternatively, when using a strip-shaped release membrane as a support sheet, it is preferable to continuously remove excess hardened resin film in a manner that creates a second region, thereby easily obtaining the protective film forming sheet 2 shown in FIG. 4. Furthermore, it is preferable to adhere the exposed surface of the cured resin film (the side opposite to the release film side) of the protective film forming sheet 2 to the adhesive surface of the support sheet serving as the adhesive sheet (e.g., the exposed surface of the adhesive layer), then cut the adhesive sheet into concentric circles larger than the cured resin film 12, and continuously remove the excess adhesive sheet, thereby obtaining the protective film forming sheet 1 shown in FIG. 2 in a state of continuous placement on the strip-shaped release film. In this case, the release film on the cured resin film can be removed when using the protective film forming sheet.

[Method for Manufacturing a Wafer with a Protective Film] A method for manufacturing a wafer with a protective film according to one embodiment of the present invention comprises: a bonding step, wherein a curable resin film described above in the protective film forming wafer of one embodiment of the present invention is heated and bonded to the surface of a wafer having protruding electrodes; a curing step, wherein the bonded curable resin film is cured, thereby forming a protective film on the aforementioned surface of the wafer; and a processing step, wherein the wafer after the protective film has been formed is diced, and the protective film is cut, thereby obtaining a wafer with a protective film, the wafer having a protective film comprising a wafer and the aforementioned protective film disposed on the diced wafer. According to the method for manufacturing a wafer with a protective film according to this embodiment, in the aforementioned bonding step, areas where the hardened resin film is not bonded to the wafer and where its thickness increases can be suppressed. As a result, in steps following the bonding step, contamination of the wafer side or any part of the wafer manufacturing apparatus with the protective film due to excess hardened resin film adhesion can be prevented.

Figures 6A to 6E are cross-sectional views illustrating one example of a method for manufacturing a wafer with a protective film according to this embodiment. Here, the example using the protective film forming sheet 1 shown in Figures 2 and 3 is used for explanation. The principle of the method for manufacturing a wafer with a protective film remains the same when using the protective film forming sheet 2 shown in Figure 4, or other protective film forming sheets of this embodiment.

In the aforementioned attachment step, the curable resin film 12 in the protective film forming sheet 1 is heated while being attached to the surface 9a of the wafer 9 with protruding electrodes 91. Thus, as shown in FIG. 6A, a wafer 101 with a protective film forming sheet is obtained. This wafer 101 has a protective film forming sheet 1 and a wafer 9 disposed in the curable resin film 12 in the protective film forming sheet 1 on a surface 12a opposite to the side of the support sheet 11. The base of the protruding electrodes 91 in the wafer 9 near the aforementioned surface 9a is formed by being covered by the curable resin film 12. Furthermore, Figure 6A shows the state where the top of the protruding electrode 91 is covered by the hardened resin film 12, but it could also show the state where the top of the protruding electrode 91 is not covered by the hardened resin film 12 and is exposed. In addition, when the support piece 11 is an adhesive piece or a support piece with a jig adhesive layer, the periphery of the support piece 11 can also be attached to a jig such as a ring frame (not shown).

The support sheet 11 in the protective film forming sheet 1 has a second region 112a on one side 11a. Therefore, when the curable resin film 12 in the protective film forming sheet 1 is attached to the surface 9a of the wafer 9 with protruding electrodes, the area of the curable resin film 12 not attached to the wafer 9 can be narrowed or disappeared, thereby reducing the amount of flowing curable resin film. In addition, the area near the periphery of the area of the curable resin film 12 not attached to the wafer 9 will not become cold. As a result, in the aforementioned attachment step, even if the hardened resin film 12 flows outward along the diameter of the wafer 9 (to the left, right, or left and right in Figure 6A) due to the pressure during attachment in the thickness direction, that is, from the area attached to the wafer 9 (on the first area 111a of the support sheet 11) to the area not attached to the wafer 9 (on the second area 112a of the support sheet 11), it is possible to suppress the formation of an area where the thickness of the hardened resin film 12 increases on the second area 112a of the support sheet 11.

On the surface 9a of wafer 9, which has protruding electrodes 91, a plurality of grooves 90 are formed to divide wafer 9 into wafers, thus becoming the dicing portions of wafer 9. In this case, during the aforementioned attachment step, when the curable resin film 12 is attached to the aforementioned surface 9a of wafer 9, the curable resin film 12 fills part or all of the aforementioned grooves 90. Figure 6A shows the state in which the entire area of the grooves 90 is filled with the curable resin film 12.

The groove 90 can be formed, for example, by forming a cut in the thickness direction of the wafer 9 from the aforementioned surface 9a using a known cutting method. This method is sometimes referred to as "half-cut" in the field. Examples of cutting methods include blade cutting and plasma cutting, and there is no particular limitation.

The depth of the groove 90 is not particularly limited as long as it does not reach the thickness of the wafer 9, but is preferably 30μm to 700μm, more preferably 60μm to 600μm, and even more preferably 100μm to 500μm. Because the depth of the groove 90 is above the aforementioned lower limit, the grinding surface can be easily reached by grinding the inner surface 9b of the wafer 9 in the subsequent processing steps, thus making it easier to cleave the wafer 9. Because the depth of the groove 90 is below the aforementioned upper limit, the strength of the wafer 9 before grinding becomes higher.

The width of the groove 90 is preferably 10μm to 2000μm, more preferably 30μm to 1000μm, further preferably 40μm to 500μm, and even more preferably 50μm to 300μm. By having the width of the groove 90 above the aforementioned lower limit, it is easier to prevent the monolithized wafers from contacting each other due to grinding vibrations during the grinding process described later in the processing steps. By having the width of the groove 90 below the aforementioned upper limit, the strength of the wafer 9 before grinding becomes higher.

The height of the protruding electrode 91 is not particularly limited, but is preferably 30μm to 300μm, more preferably 60μm to 250μm, and even more preferably 80μm to 200μm. By ensuring the height of the protruding electrode 91 is above the aforementioned lower limit, the functionality of the protruding electrode 91 can be further improved. By ensuring the height of the protruding electrode 91 is below the aforementioned upper limit, it is easier to install the protruding electrodes 91 at high density, and the possibility of damage to the protruding electrodes 91 during wafer processing can be reduced. In this specification, the term "height of the protruding electrode" refers to the height of the portion of the protruding electrode located at the highest point on the wafer's surface (electrical surface) where the protruding electrode is located.

The thickness of wafer 9 is not particularly limited, but is preferably 100μm to 1000μm, more preferably 200μm to 900μm, and even more preferably 300μm to 800μm. By having the thickness of wafer 9 above the aforementioned lower limit, wafer warping caused by shrinkage during the curing of the hardening resin film 12 can be easily suppressed. By having the thickness of wafer 9 below the aforementioned upper limit, the amount of grinding on the inner surface 9b of wafer 9 in the subsequent processing steps can be suppressed, thus shortening the grinding time.

The heating of the curable resin film 12 while it is being heated and attached to the aforementioned surface 9a of the wafer 9 can be performed by known methods. For example, the wafer can be heated by raising the temperature of the stage on which the wafer is placed, and the heated wafer can be used as a heat source to heat the curable resin film 12.

The temperature (heating temperature) of the curable resin film 12 when it is heated and attached to the aforementioned surface 9a of the wafer 9 is not particularly limited, but is preferably 50°C to 150°C, more preferably 60°C to 130°C, and even more preferably 70°C to 110°C. By setting the aforementioned temperature above the aforementioned lower limit, the curable resin film 12 can be filled more seamlessly into the base of the protruding electrode 91 or the groove 90. By setting the aforementioned temperature below the aforementioned upper limit, the undesirable condition of excessive flowability of the curable resin film 12 can be suppressed.

The pressure applied to the hardened resin film 12 while it is being heated and attached to the aforementioned surface 9a of the wafer 9 (the pressure applied in the thickness direction of the wafer 9) is not particularly limited, but is preferably 0.1 MPa to 1.5 MPa, more preferably 0.3 MPa to 1 MPa. By applying a pressure above the aforementioned lower limit, the hardened resin film 12 can be filled into the trench 90 of the wafer 9 to a greater extent without gaps. By applying a pressure below the aforementioned upper limit, damage to the wafer 9 can be suppressed to a greater extent.

In the aforementioned attachment step, it is preferable to use a roller to attach the cured resin film 12 to the aforementioned surface 9a of the wafer 9. When using a roller to attach the cured resin film of a conventional product to the aforementioned surface 9a of the wafer 9, the following undesirable situation is likely to occur: the cured resin film of the conventional product flows from the area attached to the wafer to the area not attached to the wafer, resulting in the area not attached to the wafer being thicker than the area attached to the wafer. The reason is that the flow direction of the cured resin film is deviated in the direction of roller travel. In contrast, in this embodiment, by using the aforementioned protective film forming sheet, this undesirable situation can be suppressed. That is, in this embodiment, by using a roller to attach the hardened resin film 12 to the aforementioned surface 9a of the wafer 9 in the aforementioned attachment step, the effect of the present invention is significantly improved.

The curable resin film 12 can be attached to the aforementioned surface 9a of the wafer 9 using a roller by a known method. That is, the outermost surface of the support sheet 11 side of the protective film forming sheet 1 (the side of the support sheet 11 opposite to the side of the curable resin film 12) is brought into contact with the roller surface of the rotating roller, thereby feeding the protective film forming sheet 1 in the direction of roller travel, while the aforementioned surface 9a of the wafer 9 is brought into close contact with the side 12a of the curable resin film 12 in the protective film forming sheet 1, which is opposite to the side of the support sheet 11, thereby attaching the curable resin film 12 to the aforementioned surface 9a of the wafer 9.

As for wafer 9, it is preferable to use a wafer in which the area of the wafer 9 when viewed from above the surface 9a having the protruding electrodes 91 (i.e., the area of the aforementioned surface 9a when viewed from above) is equal to or greater than the area of the surface 12a of the cured resin film 12 opposite to the side of the support sheet 11 (i.e., the area of the surface of the cured resin film 12 that adheres to the wafer 9). Furthermore, in the aforementioned attachment step, it is preferable to use this type of wafer 9 to attach the entire surface 12a (the surface of the surface of the wafer 9 that adheres to the wafer 9) of the cured resin film 12 to the aforementioned surface 9a of the wafer 9. In this way, the entire surface 12a of the cured resin film 12 is covered by the surface 9a of the wafer 9, thereby further reducing the amount of cured resin film 12 spilling onto the second region 112a of the support sheet 11. Consequently, it further suppresses the formation of areas where the cured resin film 12 is not attached to the wafer and has increased thickness.

Regarding further suppressing the formation of areas where the thickness of the hardened resin film 12 increases, suitable combinations of the hardened resin film 12 and the wafer 9 used in the aforementioned attachment step include, for example: a combination of a hardened resin film 12 with a maximum width (diameter) D ₁₂ of 140mm to 150mm and a wafer 9 with a diameter of 6 inches; a combination of a hardened resin film 12 with a maximum width (diameter) D ₁₂ of 190mm to 200mm and a wafer 9 with a diameter of 8 inches; a combination of a hardened resin film 12 with a maximum width (diameter) D ₁₂ of 290mm to 300mm and a wafer 9 with a diameter of 12 inches; and a combination of a hardened resin film 12 with a maximum width (diameter) D 12 of 140mm to 150mm and a wafer 9 with a diameter of 6 inches. ₁₂ is a combination of a 440mm to 450mm hardened resin film 12 and an 18-inch diameter wafer 9.

In the aforementioned curing step, by curing the curable resin film 12 attached to the wafer 9, a protective film 12' is formed on the aforementioned surface 9a of the wafer 9, as shown in FIG. 6B. This yields a wafer 102 with a protective film, which includes the wafer 9 and the protective film 12' disposed on the surface 9a of the wafer 9, having protruding electrodes 91. On the surface 12b' opposite to the wafer 9 side of the protective film 12' in the wafer 102, a support sheet 11 is further formed. In FIG. 6B, the symbol 12a' indicates the surface of the protective film 12' opposite to the support sheet 11 side. In the wafer 102 with a protective film, the base near the aforementioned surface 9a of the protruding electrode 91 in wafer 9 is covered by a protective film 12', and the entire area of the trench 90 of wafer 9 is filled with the protective film 12'.

The curing of the curable resin film 12 can be carried out using known methods, taking into account the characteristics of the curable resin film 12. For example, when the curable resin film 12 is thermosetting, it is cured by heating the curable resin film 12; when the curable resin film 12 is energy-curing, it is cured by irradiating the curable resin film 12 with energy rays.

During the thermocuring of the curable resin film 12, the heating temperature is preferably 100°C to 200°C, more preferably 120°C to 150°C. The heating time is preferably 0.5 hours to 5 hours, more preferably 1 hour to 3 hours. During the energy line curing of the curable resin film 12, the illuminance of the energy line is preferably 180 mW/ ^cm² to 280 mW/ ^cm² , and the light intensity of the energy line is preferably 450 mJ/ ^cm² to 1000 mJ/ ^cm² .

In the aforementioned processing steps, the wafer 9 (in the wafer 102 with protective film) after the protective film 12' is formed is diced. Thereby, the wafer 9 is monolithized into wafers 9', as shown in FIG6C, to obtain a wafer dicing body 103 with protective film. The wafer dicing body 103 with protective film has multiple wafers 9' and a protective film 12' that is not cut off and connected together on the surface 9a' of the multiple wafers 9' with protruding electrodes 91.

The wafer 9 can be diced, for example, by using a grinding machine or similar grinding mechanism to grind the inner surface 9b of the wafer 9, which is opposite to the surface 9a with the protruding electrode 91. At this time, the wafer 9 is ground from the inner surface 9b toward the surface 9a until the grinding surface reaches the groove 90 (until the groove 90 appears). By this arrangement, the thickness of the wafer 9 becomes thinner, and the groove 90 becomes the dicing point, thus dividing the wafer 9. The grinding of the inner surface 9b of the wafer 9 continues until the thickness of the wafer 9' reaches the target value.

In the aforementioned processing steps, before cutting the protective film 12', a dicing 8 is attached to the inner surface 9b' of all the wafers 9' in the wafer dicing 103 with the protective film, and the support sheet 11 is removed from the protective film 12'. Thus, as shown in FIG6D, a dicing stack 104 is obtained, which is formed by placing the wafers 9' in the wafer dicing 103 with the protective film on one side of the dicing 8.

The dicing wafer 8 may also be a known type. For example, the dicing wafer 8 may be composed solely of a substrate; or it may have a substrate and an adhesive layer disposed on one side of the aforementioned substrate. When using a dicing wafer 8 having the aforementioned substrate and adhesive layer, the adhesive layer is bonded to the inner surface 9b' of the wafer 9'.

Furthermore, in this specification, when considering both the protective film forming sheet of this embodiment (e.g., the protective film forming sheet 1 shown in Figures 2 and 3, and the protective film forming sheet 2 shown in Figure 4) and the aforementioned cutting sheet (e.g., the cutting sheet 8 shown in Figure 6D), the substrate in the protective film forming sheet of this embodiment is referred to as the "first substrate," and the substrate in the aforementioned cutting sheet is referred to as the "second substrate," thus distinguishing these substrates.

Both the second substrate in the cutting disc 8 and the aforementioned adhesive layer can be any known material. The second substrate can be the same as the first substrate. The adhesive layer can be either heat-curing or non-curing. In this specification, "non-curing" means a property that does not harden due to heating or irradiation by energy beams.

Before attaching the wafer dicing 103 with the protective film to the dicing die 8, for example, the support sheet 11 can be cut along the outline of the wafer dicing 103 with the protective film, that is, at the portion corresponding to the outer periphery of the wafer 9 before dicing. When the protective film 12' extends beyond the shape of the support sheet 11 when viewed from above the wafer 9', the portion of the protective film 12' that overflows from the support sheet 11 is simultaneously cut off. Figure 6D shows the situation in which the support sheet 11 and the protective film 12' are cut off in this way.

In the aforementioned processing steps, the surface portion of the protective film 12' opposite to the wafer 9' is then removed by cleaning, thereby exposing the upper part of the protruding electrode 91. This cleaning is preferably performed when the top of the protruding electrode 91 is covered by the hardened resin film 12, as shown in FIG. 6A. In the aforementioned processing steps, by further cutting the protective film 12', multiple wafers 105 with protective films are obtained, as shown in FIG. 6E. Each wafer 105 with a protective film includes a wafer 9' and a cut protective film 120' disposed on the wafer 9'. In this specification, the "cut protective film" is sometimes simply referred to as the "protective film". More specifically, the protective film 120' after being cut is disposed on the surface 9a' of the chip 9' with protruding electrodes 91.

The surface portion of the aforementioned surface 12b' of the protective film 12' can be cleaned by known methods such as plasma irradiation.

The protective film 12' is cut along the outer periphery (in other words, the side) of the wafer 9'. Preferably, the protective film 12' filling the space between adjacent wafers 9' is cut along the outer periphery (side) of the wafer 9', dividing it into two parts. With this arrangement, a cut protective film 120' is also provided on the side of each adjacent wafer 9'. For each wafer 9', the five surfaces—the surface 9a' with the protruding electrode 91 and the four sides—are protected by the protective film 120', thus achieving a significantly higher level of protection within the wafer 9'.

The protective film 12' can be cut by known methods. For example, the protective film 12' can be cut using a known cutting mechanism such as a cutting knife.

After the aforementioned processing steps, the resulting wafer 105 with the protective film is peeled off the dicing die 8 and picked up. The wafer 105 with the protective film can be picked up using known methods.

When using a cutting disc 8 with the aforementioned adhesive layer, the wafer 105 with the protective film can be peeled off from the adhesive layer and picked up. When the adhesive layer is hardened, picking up the wafer 105 with the protective film after the adhesive layer has hardened makes it easier to pick up.

Up to this point, the example of using a cutting blade 8 to cut the protective film 12' in the aforementioned processing steps has been given. However, as explained above, sometimes a protective film is provided on the inner surface 9b' of the wafer 9' to further protect the wafer 9'. In this case, a protective film forming sheet can be used instead of the cutting blade 8. This protective film forming sheet is composed of a support sheet, and a protective film forming film for forming the protective film is provided on one side of the support sheet. Here, the support sheet may also have a substrate and an adhesive layer. In this case, the protective film forming film is provided on the side of the adhesive layer opposite to the substrate side. When using the aforementioned protective film forming sheet, the protective film forming film is adhered to the inner surface 9b' of the wafer 9'.

Furthermore, in this specification, when considering both the protective film forming sheet of this embodiment (e.g., protective film forming sheet 1 shown in Figures 2 and 3, and protective film forming sheet 2 shown in Figure 4) and the protective film forming sheet having the aforementioned protective film forming film, the protective film forming sheet of this embodiment is referred to as the "first protective film forming sheet," and the protective film forming sheet having the aforementioned protective film forming film is referred to as the "second protective film forming sheet," thus distinguishing these protective film forming sheets. Furthermore, in this case, the support sheets in the protective film forming sheet of this embodiment (e.g., support sheet 11 shown in Figures 2 and 3, and support sheet 21 shown in Figure 4) are referred to as "first support sheets," and the support sheets in the protective film forming sheet having the aforementioned protective film forming film are referred to as "second support sheets," thus distinguishing these support sheets. Similarly, regarding the adhesive layers provided by the support sheets, the adhesive layer in the first support sheet is referred to as "first adhesive layer," and the adhesive layer in the second support sheet is referred to as "second adhesive layer," thus distinguishing these adhesive layers. Furthermore, in this case, the protective film formed from the aforementioned curable resin film using the protective film forming sheet of this embodiment (e.g., the protective film 12' shown in FIG. 6B) is referred to as the "first protective film," and the protective film formed from the aforementioned protective film forming film (e.g., the protective film disposed on the inner surface 9b' of the wafer 9') is referred to as the "second protective film," thus distinguishing these protective films.

The aforementioned second support sheet in the second protective film forming sheet may also be the same as the aforementioned first support sheet in the first protective film forming sheet.

The aforementioned protective film forming film in the second protective film forming sheet can be either curable or non-curable. The curable protective film forming film can be either thermosetting or energy-line curable, or it can possess characteristics of both thermosetting and energy-line curable. The non-curable protective film forming film is considered a protective film after the stage of setting (forming) on the target object (i.e., the wafer).

When a second protective film forming sheet with hardenability is used in the aforementioned processing steps, the second protective film can be formed by attaching the second protective film forming sheet (the aforementioned protective film forming film) to the inner surface 9b' of the wafer 9' and then hardening the protective film forming film at any stage. Alternatively, in the stage before the wafer 105 with the protective film is detached from the aforementioned second support sheet and picked up, the protective film forming film or the second protective film is cut along the outer periphery of the wafer 9'.

When using a second protective film forming sheet, the wafer 105 with the protective film can be peeled off from the second support and picked up after the aforementioned protective film forming film or second protective film has been cut from the inner surface 9b' of the wafer 9'. When the second support sheet has a hardened adhesive layer, picking up the wafer 105 with the protective film after the adhesive layer has hardened makes it easier to pick up.

The method for manufacturing a chip with a protective film in this embodiment is not limited to the above-mentioned manufacturing method (hereinafter sometimes referred to as "manufacturing method 1") as long as it sequentially includes the aforementioned attachment step , hardening step and processing step. A portion of the above-mentioned manufacturing method (manufacturing method 1) may be modified, deleted or added.

For example, this explanation has so far addressed manufacturing method 1, which involves attaching a protective film to a wafer with grooves on the surface of its protruding electrodes, and then monolithically forming the wafer into a chip by grinding the inner surface of the wafer. However, it is also possible to monolithically form a wafer into a chip by using a wafer without the aforementioned grooves and cutting it with a dicing blade—a process known as a full cut. Alternatively, a wafer without the aforementioned grooves can be used, and the wafer can be expanded by irradiating a modified layer pre-formed as a dicing starting point inside the wafer with a laser, or by utilizing the impact during grinding the inner surface of the wafer. In these variations, sometimes wafer-to-chip dicing (monolithography) and protective film cutting are performed simultaneously.

Alternatively, in manufacturing method 1, the steps of completing the protective film forming sheet and the aforementioned bonding step can be performed consecutively instead of using a pre-prepared protective film forming sheet in the aforementioned bonding step. More specifically, manufacturing method 1 may also include a cutting step just before the bonding step, in which the curing resin film formed on approximately the entire surface of the support sheet is cut into a shape identical to the shape conceived for the first region of the support sheet, thereby removing excess curing resin film to create a second region, thus completing the protective film forming sheet. By using an apparatus that continuously performs this cutting step and the aforementioned bonding step, the completion of the protective film forming sheet and the bonding to the wafer can be performed on the same production line.

Figures 7A to 7E are cross-sectional views illustrating another example of a method for manufacturing a chip with a protective film according to the present embodiment (hereinafter sometimes referred to as "manufacturing method 2"). The manufacturing method 2 described below is equivalent to manufacturing method 1 described above, but with a change in the order of some steps.

In manufacturing method 2, the aforementioned attachment step is first performed using the same method as in manufacturing method 1, as shown in FIG. 7A, to fabricate a wafer 101 for forming a protective film. In manufacturing method 2, similarly to manufacturing method 1, it is possible to suppress the thickening of the hardened resin film 12 in the second region 112a of the support sheet 11.

In the curing step described earlier in manufacturing method 2, before the curable resin film 12 is cured, the support sheet 11 and the curable resin film 12 are cut along the outer periphery of the wafer 9 on the wafer 101 with the protective film forming sheet. When the support sheet 11 is an adhesive sheet or a support sheet with a jig adhesive layer, the periphery of the support sheet 11 can be attached to a jig such as a ring frame (not shown) before the support sheet 11 and the curable resin film 12 are cut. Alternatively, the support sheet 11 can be cut and the curable resin film 12 can be removed from the curable resin film 12 without cutting.

In the aforementioned curing step of manufacturing method 2, the curable resin film 12 attached to the wafer 9 is cured using the same method as in the curing step of manufacturing method 1, thereby forming a protective film 12' on the aforementioned surface 9a of the wafer 9, as shown in FIG. 7B. This yields a wafer 102 with a protective film, having the same configuration as in manufacturing method 1. However, unlike in manufacturing method 1, the protective film 12' in the wafer 102 with the protective film may or may not have a cut support sheet 11 on the surface 12b' opposite to the wafer 9. FIG. 7B shows the case where the support sheet 11 is not present.

In the processing steps described above in manufacturing method 2, before dicing the wafer 9, the surface portion of the protective film 12', which is opposite to the side of the wafer 9, is removed by cleaning, thereby exposing the upper part of the protruding electrode 91. Then, a back polishing tape 7, which is different from the support sheet 11, is attached to the aforementioned surface 12b' of the cleaned protective film 12'.

In manufacturing method 2, the cleaning of the surface portion of the aforementioned surface 12b' of the protective film 12' can be carried out using the same method as in manufacturing method 1.

In the attachment step described earlier in manufacturing method 2, as explained above, the formation of areas where the thickness of the hardened resin film 12 increases is suppressed. Therefore, in this step, the overflow of the protective film 12' from the outer periphery of the wafer 9 is suppressed. Thus, the back surface polishing tape 7 can be stably attached to the aforementioned surface 12b' of the protective film 12'.

In the preceding processing steps of manufacturing method 2, the wafer 9 (in the protective film wafer 102) after the protective film 12' is formed is then diced. Thereby, the wafer 9 is monolithically converted into wafers 9', as shown in FIG. 7C, resulting in a protective film wafer dicing 103'. This protective film wafer dicing 103' has multiple wafers 9' and an uncut protective film 12' connected together on the surfaces 9a' of these multiple wafers 9' with protruding electrodes 91. The protective film wafer dicing 103' differs from the protective film wafer dicing 103' in that the thickness of the protective film 12' is thinner than initially achieved through cleaning.

In manufacturing method 2, the dicing of wafer 9 can be performed using the same method as in manufacturing method 1.

In the preceding processing steps of manufacturing method 2, prior to cutting the protective film 12', a dicing 8 is attached to the inner surface 9b' of all the wafers 9' in the wafer dicing 103' with the protective film, and the back-side polishing tape 7 is removed from the protective film 12'. Thus, as shown in FIG7D, a dicing stack 104' is obtained, which is formed by placing the wafer dicing 103' with the protective film and the wafers 9' facing the dicing 8 on one side of the dicing 8.

In the processing steps described earlier in manufacturing method 2, the protective film 12' is then cut off, thereby obtaining a wafer 105 with a protective film having the same structure as in manufacturing method 1, as shown in FIG7E.

In manufacturing method 2, the cutting of the protective film 12' can be performed using the same method as in manufacturing method 1. In manufacturing method 2, for the same reasons as in manufacturing method 1, when cutting the protective film 12' along the outer periphery (in other words, the side surface) of the wafer 9', it is preferable to cut the protective film 12' filling the space between adjacent wafers 9' into two pieces along the outer periphery (side surface) of the wafer 9'.

After the aforementioned processing steps in manufacturing method 2, the resulting wafer 105 with a protective film is peeled off from the dicing wafer 8 and picked up using the same method as in manufacturing method 1.

In the preceding processing steps of manufacturing method 2, a wafer without the aforementioned grooves can also be used, similarly to manufacturing method 1, to monolithize the wafer into a chip. Furthermore, manufacturing method 2 can also include the aforementioned cutting step, similar to manufacturing method 1, just before the aforementioned mounting step.

In either manufacturing method 1 or manufacturing method 2, a substrate device (not shown) can be manufactured by flip-chip bonding the top of the protruding electrode 91 of the obtained protective film wafer 105 to a bonding pad on a circuit substrate. In this case, the protective film wafer 105 is connected to the circuit formation surface of the circuit substrate. For example, if a semiconductor wafer is used as the wafer, a semiconductor device can be cited as an example of the aforementioned substrate device. [Example]

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

The raw materials used to manufacture composition (III) shown below are shown. Polymer component (A)-1: Polyvinyl butyral (S-lec BL-10 manufactured by Sekisui Chemicals Co., Ltd., with a weight average molecular weight of 25,000 and a glass transition temperature of 59°C) having the constituent units represented by formulas (i)-1, (i)-2 and (i)-3.

[Chemistry 1] (In the formula, _l1 is approximately 28, _m1 is 1 to 3, and _n1 is an integer from 68 to 74).

Epoxy Resin (B1)-1: Liquid modified bisphenol A type epoxy resin (DIC's "Epiclon EXA-4850-150", molecular weight 900, epoxy equivalent 450 g/eq). Epoxy Resin (B1)-4: Dicyclopentadiene type epoxy resin (DIC's "Epiclon HP-7200HH", epoxy equivalent 254 g/eq to 264 g/eq). Thermosetting Agent (B2)-1: o-cresol type phenolic varnish resin (DIC's "Phenolite KA-1160"). Hardening accelerator (C)-1: 2-Phenyl-4,5-dihydroxymethylimidazol (Curezol 2PHZ-PW manufactured by Shikoku Chemical Industry Co., Ltd.). Filler (D)-1: Epoxy-modified spherical silica (Admanano YA050C-MKK manufactured by Admatechs, with an average particle size of 50 nm). Additive (I)-1: Rheology control agent (polyhydroxycarboxylic acid ester, BYK-R606 manufactured by BYK Corporation).

[Example 1] Polymer component (A)-1 (100 parts by mass), epoxy resin (B1)-1 (350 parts by mass), epoxy resin (B1)-4 (270 parts by mass), thermosetting agent (B2)-1 (190 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (90 parts by mass), and additive (I)-1 (9 parts by mass) are dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain composition (III) with a total concentration of 45% by mass of all components other than the solvent, which is used as a composition for thermosetting resin film formation. Furthermore, the amounts of components other than the solvent shown here are all solvent-free target amounts.

A single-sided polysiloxane-treated release liner (Lintec Corporation's "SP-PET381031", 38 μm thick) was prepared using polyethylene terephthalate (PET). The aforementioned composition (III) was then coated onto the previously treated surface of this release liner and dried at 120°C for 2 minutes to form a 30 μm thick thermosetting resin film. Subsequently, this thermosetting resin film and the aforementioned release liner were combined and processed into a 170 mm diameter circle to create a test piece with the release liner. The exposed surface of the obtained specimen (in other words, the side opposite to the side with the release film) is bonded to the surface of a transparent strip-shaped backing abrasive tape (Lintec Corporation's "E-8180") to obtain a laminate. The resulting laminate is formed by sequentially depositing the backing abrasive tape, the specimen (thermosetting resin film), and the release film along the thickness direction of these layers.

[Example 2] The thickness of the thermosetting resin film was changed to 45 μm, and the backing abrasive tape was changed to "E-8510HR" manufactured by Lintec Corporation. Otherwise, the deposit was obtained in the same manner as in Example 1.

Furthermore, aside from setting the thickness to 50 μm instead of 45 μm, 20 additional thermosetting resin films identical to those described above were fabricated. These thermosetting resin films were laminated and cut to obtain circular plate-shaped specimens with a thickness of 1 mm and a diameter of 25 mm. The viscoelasticity of these specimens was measured using a viscoelasticity measuring device (MCR301 manufactured by Anton Paar), measuring Gc1 and Gc300, and calculating the X-value. The results are as follows: Gc1 = 115000 Pa. Gc300 = 3900 Pa. X-value = 29.

The trench filling performance of the thermosetting resin film in the aforementioned laminate was evaluated in the following order, and the result was "A". (1) Preparation of the semiconductor wafer fabrication wafer A 12-inch silicon wafer (750 μm thick) with pre-defined dicing lines was used as the semiconductor wafer fabrication wafer. The width of the diced portion of the aforementioned silicon wafer, i.e., the trench, was 60 μm, and the trench depth was 230 μm. (2) Evaluation method After removing the release film from the aforementioned laminate, the exposed surface of the thermosetting resin film (exposed surface) was pressed and attached to the diced surface of the semiconductor wafer under the following conditions. • Lamination Device: Fully automatic laminator (manufactured by Lintec Corporation, product name "RAD-3510"). • Roller Pressure: 0.5MPa. • Roller Height: -400μm. • Lamination Speed: 5mm/sec. • Lamination Temperature: 90℃. Subsequently, after peeling the back-side grinding tape from the thermosetting resin film, the semiconductor wafer with the thermosetting resin film attached is heated at 130℃ for 4 hours, thereby hardening the thermosetting resin film to form a protective film. Next, the semiconductor wafer was cut inwards from the dicing surface at the dicing portion (groove). Using an optical microscope (Keyence VHX-1000), the filling performance of the protective film at the dicing portion (groove) was evaluated. The evaluation criteria for filling performance are as follows: S: No deformation of the protective film shape was observed; the filling performance is the best. A: Slight deformation of the protective film shape was observed near the opening of the groove, but the filling performance is good. B: Poor filling performance. [Industry Applicability]

This invention can be used to manufacture chips with protruding electrodes and a protective film on the surface of the protruding electrodes. Such chips with protective films are connected to the circuit substrate by flip-chip bonding pads, making them suitable for manufacturing substrate devices.

1,2: Protective film forming sheet; 7: Backside grinding belt; 8: Dicing disc; 9: Wafer; 9': Wafer; 9a: Surface of the wafer with protruding electrodes (electrical surface); 9a': Surface of the wafer with protruding electrodes (electrical surface); 9b: Inner surface of the wafer; 9b': Inner surface of the wafer; 11,21: Support sheet; 11a,21a: One side of the support sheet (the side of the support sheet with the hardened resin film); 12,62: Cured resin film; 12': Protective film; 12a: Surface of the cured resin film opposite to the support sheet side; 12a': Surface of the protective film opposite to the support sheet side; 12b': Surface of the protective film opposite to the wafer side; 13: Fixture adhesive layer; 90: Wafer trench; 91: Wafer protrusion electrode; 101: Wafer with protective film forming layer; 102: Wafer with protective film; 103,103' : Wafer dicings with protective films 104, 104': Divided wafer stack 105: Wafers with protective films 111a, 211a: First region on one side of the support sheet 112a, 212a: Second region on one side of the support sheet 120': Protective film after cutting 620: Region near the wafer not attached to the wafer 621: Region on the wafer with a hardened resin film attached 622: Region near the periphery D ₁₁ , _D21 : Maximum width (diameter) of the support plate; _D12 : Maximum width (diameter) of the cured resin film; _L1 : Minimum value of the line segment connecting a point on the outer periphery of the first region to a point on the outer periphery of the support plate; _L2 : Distance between two adjacent cured resin films; _T12 : Thickness of the cured resin film.

[Figure 1] is a cross-sectional view schematically illustrating the problem to be solved by the present invention. [Figure 2] is a plan view schematically showing an example of a protective film forming wafer according to an embodiment of the present invention. [Figure 3] is a cross-sectional view of the protective film forming wafer shown in Figure 2 along line I-I. [Figure 4] is a plan view schematically showing another example of a protective film forming wafer according to an embodiment of the present invention. [Figure 5] is a plan view schematically showing yet another example of a protective film forming wafer according to an embodiment of the present invention. [Figure 6A] is a cross-sectional view schematically illustrating an example of a method for manufacturing a wafer with a protective film according to an embodiment of the present invention. [Figure 6B] is a cross-sectional view schematically illustrating an example of a method for manufacturing a wafer with a protective film according to an embodiment of the present invention. [Figure 6C] is a cross-sectional view illustrating one example of a method for manufacturing a wafer with a protective film according to an embodiment of the present invention. [Figure 6D] is a cross-sectional view illustrating one example of a method for manufacturing a wafer with a protective film according to an embodiment of the present invention. [Figure 6E] is a cross-sectional view illustrating one example of a method for manufacturing a wafer with a protective film according to an embodiment of the present invention. [Figure 7A] 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 7B] 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 7C] is a cross-sectional view illustrating another example of a method for manufacturing a wafer with a protective film according to one embodiment of the present invention. [Figure 7D] is a cross-sectional view illustrating another example of a method for manufacturing a wafer with a protective film according to one embodiment of the present invention. [Figure 7E] is a cross-sectional view illustrating another example of a method for manufacturing a wafer with a protective film according to one embodiment of the present invention.

1: Protective film forming sheet; 11: Support sheet; 11a: One side of the support sheet (the side of the support sheet facing the curing resin film); 12: Curing resin film; 12a: The side of the curing resin film opposite to the support sheet side; D; ₁₁ : Maximum width (diameter) of the support sheet; D; ₁₂ : Maximum width (diameter) of the curing resin film; 111a: First region of one side of the support sheet; 112a: Second region of one side of the support sheet.

Claims (16)

A protective film forming sheet comprises: a support sheet; and a curable resin film disposed on one side of the support sheet; the curable resin film is used to adhere to and cure the surface of a wafer with protruding electrodes, thereby forming a protective film on the surface of the wafer; the support sheet has a first region with the curable resin film disposed thereon on the first side, and a second region surrounding the first region without the curable resin film; the film is formed at a temperature of 90°C and a frequency of... A strain was induced in a specimen of the aforementioned hardened resin film with a diameter of 25 mm and a thickness of 1 mm under a 1 Hz condition. The storage elastic modulus of the specimen was measured. When the strain of the specimen was 1%, the storage elastic modulus of the specimen was set as Gc1. When the strain of the specimen was 300%, the storage elastic modulus of the specimen was set as Gc300. The value of X calculated by the following formula: X=Gc1/Gc300 was 19 or more but less than 10000. The protective film forming sheet as described in claim 1, wherein the thickness of the aforementioned hardened resin film is 25 μm or more. The protective film forming sheet as described in claim 1 or 2, wherein the maximum width of the aforementioned hardened resin film is 140 mm to 150 mm. The protective film forming sheet as described in claim 1 or 2, wherein the maximum width of the aforementioned hardened resin film is 190 mm to 200 mm. The protective film forming sheet as described in claim 1 or 2, wherein the maximum width of the aforementioned hardened resin film is 290 mm to 300 mm. The protective film forming sheet as described in claim 1 or 2, wherein the maximum width of the aforementioned hardened resin film is 440 mm to 450 mm. The protective film forming sheet as described in claim 1 or 2, wherein the aforementioned support sheet is circular. As described in claim 7, the protective film forming sheet is an adhesive sheet, or has a jig adhesive layer along the outer periphery of the aforementioned support sheet. The protective film forming sheet as described in claim 1 or 2, wherein the aforementioned support sheet is a peeling film. The protective film forming sheet as described in claim 1 or 2, wherein a groove is formed on the aforementioned surface of the aforementioned wafer to serve as a dicing portion of the aforementioned wafer. A method for manufacturing a wafer with a protective film includes: an attachment step, in which a curable resin film in a protective film forming wafer as described in any one of claims 1 to 10 is attached to a surface of a wafer having protruding electrodes while being heated; a curing step, in which the attached curable resin film is cured to form a protective film on the aforementioned surface of the wafer; and a processing step, in which the aforementioned wafer after the formation of the protective film is diced and the aforementioned protective film is cut to obtain a wafer with a protective film, wherein the wafer with a protective film has a wafer and the aforementioned protective film disposed on the diced wafer. As described in claim 11, in the method for manufacturing a wafer with a protective film, a wafer is used as the wafer whose area when viewed from above is equal to or greater than the area of the surface of the hardened resin film facing the wafer; in the aforementioned attachment step, the entire surface of the aforementioned surface of the hardened resin film is attached to the aforementioned surface of the wafer. As described in claim 11, in the method for manufacturing a wafer with a protective film, a groove is formed on the aforementioned surface of the aforementioned wafer to form a segmentation portion of the aforementioned wafer; in the aforementioned attachment step, when the aforementioned hardened resin film is attached to the aforementioned surface facing the aforementioned wafer, the aforementioned hardened resin film is filled into the aforementioned groove. The method for manufacturing a wafer with a protective film as described in claim 11, wherein in the aforementioned attachment step, a roller is used to attach the aforementioned hardened resin film to the aforementioned surface of the aforementioned wafer. A deposit is obtained by: forming a thermosetting resin film on the peeling surface of a peeling membrane; processing the thermosetting resin film and the peeling membrane together into a circular shape; bonding the entire surface of the surface opposite to the side having the peeling membrane to the surface of a strip-shaped back abrasive belt; and molding the aforementioned thermosetting resin film, with a diameter of 25 mm and a thickness of 1 mm, at a temperature of 90°C and a frequency of 1 Hz. The test piece of the chemical resin film exhibits strain, and the storage elastic modulus of the test piece is measured. When the strain of the test piece is 1%, the storage elastic modulus of the test piece is set as Gc1, and when the strain of the test piece is 300%, the storage elastic modulus of the test piece is set as Gc300. The value of X calculated by the following formula: X=Gc1/Gc300 is 19 or more but less than 10000. A laminate comprises: a peeling membrane; a thermosetting resin film disposed on a peeling treatment surface of the peeling membrane; and a back abrasive belt disposed on a side of the thermosetting resin film opposite to the peeling membrane side; wherein the planar shape of the peeling membrane and the planar shape of the thermosetting resin film are both circular; the peeling membrane and the thermosetting resin film are arranged symmetrically at their radially peripheral positions; the back abrasive belt is strip-shaped; and a temperature... A thermosetting resin film specimen with a diameter of 25 mm and a thickness of 1 mm was subjected to strain at 90°C and a frequency of 1 Hz. The storage elastic modulus of the specimen was measured. The storage elastic modulus of the specimen when the strain of the specimen was 1% was set as Gc1, and the storage elastic modulus of the specimen when the strain of the specimen was 300% was set as Gc300. The value of X calculated by the following formula: X=Gc1/Gc300 was 19 or more but less than 10000.