Method for manufacturing resin film, composite sheet, and semiconductor chip with first protective film

Abstract

This resin film is a thermosetting resin film and exhibits an amount of heat generation of not more than 100 J / g in the temperature range of 100-300°C when, using the pre-thermoset resin film as a first test specimen, the first test specimen is analyzed by differential scanning calorimetry (DSC) using conditions of a constant rate of temperature rise at a rate of temperature rise of 10°C / min.

Description

[Technical Field]

[0001] The present invention relates to a resin film, a composite sheet, and a method for manufacturing a semiconductor chip with a first protective film. 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. [Background technology]

[0002] Conventionally, when mounting a multi-pin LSI package used in an MPU, gate array, or the like on a printed wiring board, a semiconductor chip with convex electrodes (hereinafter referred to as "bumps" in this specification) made of eutectic solder, high-temperature solder, gold, or the like formed on its connection pads has been used, and the so-called face-down method of flip-chip mounting has been adopted in which these bumps are brought face-to-face and into contact with corresponding terminal portions on a chip-mounting substrate, and melted / diffusion bonded.

[0003] The semiconductor chips used in this packaging method are obtained, for example, by grinding or dicing the surface opposite to the circuit surface (i.e., the bump-formed surface) of a semiconductor wafer having bumps formed on its circuit surface into individual pieces. In the process of obtaining such semiconductor chips, a curable resin film is usually attached to the bump-formed surface of the semiconductor wafer in order to protect the bumps and the bumps, and this film is cured to form a protective film on the bump-formed surface.

[0004] On the other hand, semiconductor devices are expected to have higher functionality, and the size of semiconductor chips is tending to increase. However, larger-sized semiconductor chips are prone to deformation of bumps due to warping when mounted on a substrate, and cracks are particularly likely to occur in bumps located at or near the edge of the semiconductor chip. A protective film formed on the bump-forming surface is also expected to suppress such damage to the bumps.

[0005] A method for forming a protective film on the bump-formed surface of a semiconductor wafer will be described with reference to FIGS. 8A to 8D. To form the protective film, a protective film formation sheet 8 as shown in Fig. 8A is used. The protective film formation sheet 8 is configured by laminating an adhesive layer 83 and a curable resin film 82 in this order on a base material 81.

[0006] First, the protective film forming sheet 8 is placed so that the curable resin film 82 faces the bump formation surface 9a of the semiconductor wafer 9. Next, the protective film formation sheet 8 is pressed against the semiconductor wafer 9, and as shown in Fig. 8B, the curable resin film 82 of the protective film formation sheet 8 is bonded to the bump formation surface 9a of the semiconductor wafer 9. At this time, the curable resin film 82 is bonded while being heated. As a result, the curable resin film 82 is in close contact with the bump formation surface 9a of the semiconductor wafer 9 and the surfaces 91a of the bumps 91, and if the bumps 91 penetrate the curable resin film 82, the adhesive layer 83 is also in close contact with part of the surfaces 91a of the bumps 91. After bonding such a curable resin film 82, if necessary, the surface (back surface) 9b of the semiconductor wafer 9 opposite to the bump formation surface 9a is ground, and then a protective film forming sheet is separately attached to the back surface 9b of the semiconductor wafer 9 to protect this back surface 9b (not shown).

[0007] Next, as shown in FIG. 8C, the substrate 81 and the adhesive layer 83 are removed from the curable resin film 82. The curable resin film 82 is then cured to form a protective film 82' as shown in FIG. 8D.

[0008] As such, a protective film forming sheet capable of forming a protective film on the bump formation surface of a semiconductor wafer has been disclosed in which the curable resin film is thermosetting and has a melt viscosity within a specific range, and the adhesive layer has a shear modulus within a specific range at a specific temperature range (see Patent Document 1). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2015-092594 Summary of the Invention [Problem to be solved by the invention]

[0010] Various methods for dividing a semiconductor wafer into semiconductor chips are known. One example involves using a semiconductor wafer with a bump-formed surface that has grooves formed thereon, which serve as dividing points. As described above, the surface opposite the bump-formed surface (back surface) of the semiconductor wafer is ground, and the ground surface (back surface) reaches the grooves to divide the semiconductor wafer into semiconductor chips. When this method is employed, if a curable resin film in a protective film-forming sheet is bonded to the bump-formed surface of the semiconductor wafer prior to dividing the semiconductor wafer, and the grooves are sufficiently filled with the curable resin film, the semiconductor wafer is divided and the curable resin film is cured, thereby covering not only the bump-formed surface of the semiconductor chip but also its side surfaces with a protective film. A semiconductor chip having a protective film not only on the bump-formed surface but also on its side surfaces is shown in FIG. 9. FIG. 9 is a cross-sectional view schematically illustrating an example of a semiconductor chip (semiconductor chip with a protective film) having a protective film on the bump-formed surface and side surfaces, assuming that it is obtained normally using the protective film-forming sheet 8 described above.

[0011] The semiconductor chip 909 with a protective film shown here comprises a semiconductor chip 9' and a first protective film 820' provided on a side surface 9c' and a bump-forming surface 9a' of the semiconductor chip 9'. The semiconductor chip 9' is protected on its side surface 9c' and bump-forming surface 9a' by the first protective film 820' after cutting, and the semiconductor chip 9' provides a significantly high level of protection.

[0012] A thermosetting resin film may be used as the curable resin film. When the filled resin film is thermally cured, the thermosetting resin film may partially fail to cure if the grooves filled with the resin film have a fine shape and heat is not uniformly transferred to the resin film. If this occurs, the protective effect of the chip may be reduced below the expected value. Furthermore, when a protective film that has not cured properly is cut along the gaps between semiconductor chips, processing debris generated during cutting may adhere to the semiconductor chips or wafers, or the cut surfaces of the protective film may re-adhere. In contrast, it is not clear whether the sheet for forming a protective film (film for forming a protective film) disclosed in Patent Document 1 can solve these problems.

[0013] So far, we have explained the case where a curable resin film is applied to the bump-formed surface of a semiconductor wafer, but this is not limited to this case, and the resin film may be applied to an uneven surface other than the bump-formed surface of a semiconductor wafer. However, when applying the resin film to such an uneven surface, there is a possibility that the resin film may not cure properly.

[0014] The present invention aims to provide a resin film that can be applied to an uneven surface and can form a protective film, such that when the resin film is filled into grooves on the uneven surface and cut after being subjected to a heat treatment for thermal curing, processing debris that may be generated during cutting is unlikely to adhere to a semiconductor chip or wafer, and a composite sheet including the resin film that is used when applying the resin film to an uneven surface. [Means for solving the problem]

[0015] The present invention has the following aspects. [1] A thermosetting resin film, A resin film in which the heat generation value in the range of 100 to 300°C is 100 J / g or less, as obtained by analyzing the resin film before heat curing as a first test piece by differential scanning calorimetry (DSC) under a constant heating rate of 10°C / min. [2] The resin film contains a thermosetting component (B), The resin film according to [1] above, wherein the content of the thermosetting component (B) is 10 to 75 mass % relative to the total mass of the resin film. [3] A resin film having a diameter of 25 mm and a thickness of 1 mm was used as a second test piece, and strain was generated in the second test piece under conditions of a temperature of 90°C and a frequency of 1 Hz to measure the storage modulus of the second test piece. When the storage modulus of the second test piece when the strain of the second test piece is 1% is defined as Gc1, and when the storage modulus of the second test piece when the strain of the second test piece is 300% is defined as Gc300, the following formula is obtained: X=Gc1 / Gc300 The resin film according to [1] or [2] above, wherein the X value calculated by the above formula is 19 or more and less than 10,000. [4] The resin film according to any one of [1] to [3] above, which is intended to be attached to an uneven surface. [5] The resin film according to any one of [1] to [4] above, which is used to protect the uneven surface and side surfaces of a semiconductor chip. [6] A support sheet and a resin film provided on one surface of the support sheet, The composite sheet, wherein the resin film is the resin film according to any one of [1] to [5] above. [7] The composite sheet according to [6], wherein the support sheet comprises a substrate and an adhesive layer provided on one side of the substrate, and the adhesive layer is disposed between the substrate and the resin film. [8] The composite sheet according to [6] or [7], wherein the support sheet comprises a substrate and a buffer layer provided on one side of the substrate, and the buffer layer is disposed between the substrate and the resin film. [9] A method for manufacturing a semiconductor chip with a first protective film using a semiconductor wafer, comprising: the semiconductor chip with a first protective film includes a semiconductor chip and a first protective film provided on a side surface of the semiconductor chip and a surface having bumps, the semiconductor wafer has, on one surface thereof, bumps and grooves that become dividing portions of the semiconductor wafer; The manufacturing method includes a bonding step of bonding the resin film in the composite sheet according to any one of [6] to [8] to the one surface of the semiconductor wafer, thereby producing a semiconductor wafer with a resin film, in which the one surface is provided with the resin film and the grooves are filled with the resin film; The manufacturing method further comprises: a curing step (1) of thermally curing the resin film after the bonding step to form the first protective film, thereby producing a semiconductor wafer with a first protective film, the semiconductor wafer including the semiconductor wafer and the first protective film provided on the one surface of the semiconductor wafer and filling the grooves; a dividing step (1) of dividing the semiconductor wafer after the curing step (1), thereby producing a group of semiconductor chips with a first protective film, the group of semiconductor chips including a plurality of semiconductor chips and the first protective film provided on surfaces of the plurality of semiconductor chips having the bumps and in gaps between the semiconductor chips; and a cutting step (1) of cutting the first protective film along the gaps between the semiconductor chips in the group of semiconductor chips with a first protective film, after the dividing step (1), thereby producing the semiconductor chips with a first protective film; a cutting step (2) of cutting the first protective film along the grooves in the semiconductor wafer with the first protective film after the bonding step and the curing step (1) to produce a cut-in semiconductor wafer with the first protective film, and a dividing step (2) of dividing the semiconductor wafer after the cutting step (2) to produce semiconductor chips with the first protective film, or A method for manufacturing a semiconductor chip with a first protective film, comprising: a dividing step (3) of dividing the semiconductor wafer after the bonding step to produce a group of semiconductor chips with a resin film, the group including a plurality of the semiconductor chips and the resin film provided on the surfaces of the plurality of semiconductor chips having the bumps and in the gaps between the semiconductor chips; a hardening step (3) of thermally hardening the resin film after the dividing step (3) to form the first protective film, thereby producing a group of semiconductor chips with a first protective film, the group including a plurality of the semiconductor chips and the first protective film provided on the surfaces of the plurality of semiconductor chips having the bumps and in the gaps between the semiconductor chips; and a cutting step (3) of cutting the first protective film along the gaps between the semiconductor chips in the group of semiconductor chips with a first protective film after the hardening step (3), to obtain the semiconductor chips with a first protective film. [Effects of the Invention]

[0016] According to the present invention, there are provided a resin film that can be applied to an uneven surface and can form a protective film, and when the resin film is filled into grooves on the uneven surface and cut after being subjected to a heat treatment for thermal curing, processing debris that may be generated during cutting is unlikely to adhere to a semiconductor chip or wafer, and a composite sheet including the resin film that is used when applying the resin film to an uneven surface. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view schematically illustrating an example of a resin film according to one embodiment of the present invention. [Figure 2] FIG. 10 is a plan view for schematically explaining the amount of protrusion of a resin film when the planar shape of the resin film is circular. [Figure 3] 1 is a cross-sectional view schematically illustrating an example of a composite sheet according to an embodiment of the present invention. [Figure 4A] 4 is a cross-sectional view schematically showing an example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 4B]4 is a cross-sectional view schematically showing an example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 4C] 4 is a cross-sectional view schematically showing an example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 4D] 4 is a cross-sectional view schematically showing an example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 4E] 4 is a cross-sectional view schematically showing an example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 5A] 4 is a cross-sectional view schematically showing another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 5B] 4 is a cross-sectional view schematically showing another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 5C] 4 is a cross-sectional view schematically showing another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 5D] 4 is a cross-sectional view schematically showing another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 5E] 4 is a cross-sectional view schematically showing another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 6A] 4 is a cross-sectional view schematically showing yet another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 6B] 4 is a cross-sectional view schematically showing yet another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 6C] 4 is a cross-sectional view schematically showing yet another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 6D]4 is a cross-sectional view schematically showing yet another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 6E] 4 is a cross-sectional view schematically showing yet another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet shown in FIG. 3 is used. FIG. [Figure 7] 1 is a plan view schematically showing a laminate including a thermosetting resin film produced when measuring the amount of protrusion of the thermosetting resin film in Example 1. FIG. [Figure 8A] 1A to 1C are cross-sectional views for schematically explaining a method for forming a protective film on a bump-formed surface of a semiconductor wafer. [Figure 8B] 1A to 1C are cross-sectional views for schematically explaining a method for forming a protective film on a bump-formed surface of a semiconductor wafer. [Figure 8C] 1A to 1C are cross-sectional views for schematically explaining a method for forming a protective film on a bump-formed surface of a semiconductor wafer. [Figure 8D] 1A to 1C are cross-sectional views for schematically explaining a method for forming a protective film on a bump-formed surface of a semiconductor wafer. [Figure 9] 1 is a cross-sectional view schematically showing an example of a semiconductor chip having a protective film on a bump-forming surface and a side surface. DETAILED DESCRIPTION OF THE INVENTION

[0018] Resin film and its manufacturing method A resin film according to one embodiment of the present invention is a thermosetting resin film, and the resin film before thermosetting is used as a first test piece. When the first test piece is analyzed by differential scanning calorimetry (DSC) under a constant heating rate of 10°C / min, the heat value of the exothermic peak in the range of 100 to 300°C is 100 J / g or less.

[0019] The resin film of this embodiment is suitable for application to uneven surfaces. Furthermore, the resin film of this embodiment is thermosetting, and can form a protective film by thermal curing. The resin film of this embodiment is suitable for protecting the uneven surfaces and side surfaces of semiconductor chips. Hereinafter, in this specification, unless otherwise specified, a resin film refers to a thermosetting resin film, and "curing" a resin film refers to "thermosetting."

[0020] When the resin film of this embodiment is applied to an uneven surface while being heated, the softened resin film spreads between the convex portions to cover the convex portions, adheres closely to the uneven surface, and covers the surfaces of the convex portions, particularly the surfaces near the convex portions, embedding the bases of the convex portions. In this case, preferably, the convex portions of the uneven surface penetrate the resin film, with the upper portions of the convex portions protruding from the resin film. Furthermore, if the uneven surface has fine grooves, the resin film can fill these grooves, thereby preventing poor curing of the resin film when a heat treatment for thermal curing is performed after filling. The reason poor curing of the resin film can be prevented in this way is that the calorific value of the first test piece of the resin film is 100 J / g or less.

[0021] When the resin film of this embodiment is applied to an uneven surface, the heating temperature and application pressure of the resin film can be adjusted appropriately depending on other application conditions and the width and depth of the grooves on the uneven surface, but can be the same as when applied to the bump-forming surface of a semiconductor wafer, as described below.

[0022] The degree to which the resin film or protective film fills the grooves on the uneven surface (sometimes referred to in this specification as "groove filling suitability") can be confirmed by observing the uneven surface provided with the resin film or protective film using an optical microscope. The degree of generation of processing waste that may be generated when cutting the resin film after heat treatment for thermosetting can be confirmed by observing the intersection of the cutting lines using an optical microscope.

[0023] When the resin film of this embodiment is attached to the uneven surface, a composite sheet including the resin film of this embodiment can be used. The composite sheet will be described in detail later.

[0024] More specifically, an example of an object to which the resin film is to be attached, which has an uneven surface, is a semiconductor wafer having bumps. That is, the resin film can be attached to a semiconductor wafer before it is divided into semiconductor chips. In this case, the resin film is attached to the surface of the semiconductor wafer having bumps.

[0025] In this specification, the surface of either a semiconductor wafer or a semiconductor chip that has bumps thereon may be referred to as a "bump-formed surface."

[0026] By applying the resin film to the bump-forming surface while heating it, the softened resin film spreads between the bumps to cover them, adheres to the bump-forming surface, and covers the surfaces of the bumps, particularly the surfaces in the vicinity of the bump-forming surface, embedding the bases of the bumps. In this case, preferably, the bumps on the bump-forming surface penetrate the resin film, and the tops of the bumps protrude from the resin film. Furthermore, if the bump-forming surface has fine grooves, the resin film can fill these grooves.

[0027] The resin film provided on the bump-forming surface and filling the grooves is then cured in this state to finally form a first protective film. In the resin film of the embodiment, the calorific value of the first test piece made using the resin film is 100 J / g or less, thereby suppressing poor curing.

[0028] In this specification, the protective film provided on the bump-formed surface of the semiconductor wafer or semiconductor chip is referred to as a "first protective film," and the protective film provided on the surface opposite to the bump-formed surface of the semiconductor wafer or semiconductor chip (i.e., the back surface) is referred to as a "second protective film."

[0029] The resin film is thermosetting, and may have both thermosetting and energy ray curing properties.

[0030] As used herein, "energy rays" refers to electromagnetic waves or charged particle beams that have an energy quantum. Examples of energy rays include ultraviolet rays, radioactive rays, and electron beams. Ultraviolet rays can be irradiated using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, or an LED lamp as an ultraviolet light source. Electron beams can be irradiated using those generated by an electron beam accelerator or the like. In addition, in this specification, "energy ray curable" means a property of being cured by irradiation with energy rays, and "non-energy ray curable" means a property of not being cured even when irradiated with energy rays. Moreover, "non-curable" means a property that does not cure by any means such as heating or irradiation with energy rays.

[0031] In order to analyze the heat quantity corresponding to the heat of reaction during curing of the resin film, in this embodiment, the measured value of the heat generation of the resin film by differential scanning calorimetry (DSC) is used. To measure the heat generation quantity of the resin film, a first test piece of the resin film before thermal curing is used. In terms of suitability for DSC analysis and ease of preparation, the first test piece is preferably a laminated film composed of multiple single-layer resin films each having a thickness of less than 0.5 mm. In addition, it is preferable to use a test piece of 5 mg or more. The calorific value is the calorific value in the range of 100 to 300°C, which is obtained by DSC analysis in which the first test piece is measured under a constant temperature rise condition of a temperature rise rate of 10°C / min. The calorific value can be determined as the integral value of the exothermic peak in the range of 100 to 300°C in the DSC curve obtained by the DSC analysis.

[0032] The calorific value of the first test piece is 100 J / g or less, for example, preferably 10 to 100 J / g, more preferably 50 to 90 J / g, and even more preferably 60 to 80 J / g. When the calorific value is less than the upper limit, poor curing of the resin film is unlikely to occur even in a state where heat transfer to the resin film is likely to be uneven, such as when a resin film filled in fine grooves is thermally cured. Furthermore, when the calorific value is more than the lower limit, the resin film exhibits good thermosetting performance.

[0033] The calorific value of the first test piece can be easily adjusted by adjusting the type or content of the components contained in the resin film. To achieve this, the type or content of the components contained in the composition for forming the resin film may be adjusted. For example, when using the thermosetting resin film-forming composition (III) described below, the calorific value can be easily adjusted by adjusting the type or content of the main components contained in the composition, such as the thermosetting component (B) (e.g., epoxy resin (B1) and thermosetting agent (B2)), filler (D), etc. For example, when the content of the thermosetting component (B) in the thermosetting resin film and the composition (III) (for example, the total content of the epoxy resin (B1) and the thermosetting agent (B2)) is reduced, the calorific value tends to decrease.

[0034] In this embodiment, the resin film having a diameter of 25 mm and a thickness of 1 mm is used as a second test piece, and strain is generated in the second test piece under conditions of a temperature of 90°C and a frequency of 1 Hz to measure the storage elastic modulus of the second test piece. When the storage elastic modulus of the second test piece when the strain of the second test piece is 1% is defined as Gc1, and when the storage elastic modulus of the second test piece when the strain of the second test piece is 300% is defined as Gc300, the following formula is obtained: X=Gc1 / Gc300 It is preferable that the X value calculated by the above formula is 19 or more and less than 10,000 (19≦X value<10,000). When such a resin film is attached to an uneven surface, when the convex portions of the uneven surface penetrate the resin film and the upper portions of the convex portions protrude from the resin film, the resin film is prevented from remaining at the upper portions of the convex portions. Naturally, the cured resin film in this state is also prevented from adhering to the upper portions of the convex portions. Furthermore, since the resin film after attachment is prevented from protruding from its original size, for example, protrusion of the resin film from the uneven surface is prevented. Furthermore, when the resin film and its cured product are provided on the uneven surface, the regions of the convex portions of the uneven surface other than the upper portions (for example, base portions near the uneven surface) or regions near the convex portions of the uneven surface are unintentionally exposed without being covered by the resin film and its cured product, i.e., so-called repelling. In this way, when the X value is 19 or more and less than 10,000, the resin film has superior properties in that the entire uneven surface can be covered by the resin film itself and its cured product while exposing the convex portions.

[0035] The second test piece for measuring strain dispersion is in the form of a film, and its planar shape is circular. The second test piece may be a single layer of the resin film having a thickness of 1 mm, but in terms of ease of production, it is preferable that it is a laminated film composed of multiple single layer resin films having a thickness of less than 1 mm. The thicknesses of the multiple single-layer resin films that make up the laminated film may all be the same, all different, or only some of them may be the same, but from the standpoint of ease of production, it is preferable that they all be the same.

[0036] In this specification, the "storage modulus of the second test piece" is not limited to Gc1 and Gc300, but means "the storage modulus of the second test piece corresponding to the strain generated when strain is generated in the second test piece of a resin film having a diameter of 25 mm and a thickness of 1 mm under the conditions of a temperature of 90°C and a frequency of 1 Hz."

[0037] When a resin film is applied to the uneven surface of an object to be applied, the degree of distortion of the resin film differs significantly between the middle stage when the tops of the convex portions of the uneven surface (the tops of the bumps if the object to be applied is a semiconductor wafer with bumps) penetrate the resin film and protrude, and the final stage when the resin film embeds the bases of the convex portions after the tops of the convex portions have penetrated the resin film and protrude. More specifically, the distortion of the resin film is large in the middle stage and small in the final stage. The resin film of this embodiment employs Gc1 as the storage modulus when the strain is small and Gc300 as the storage modulus when the strain is large, and by setting the X value (= Gc1 / Gc300) to a specific range by making Gc1 high and Gc300 low, the excellent effects described above are achieved.

[0038] Whether or not the resin film remains on the tops of the convex portions of the textured surface can be confirmed, for example, by obtaining SEM image data of the tops of the convex portions. Furthermore, whether or not the resin film is protruding from the uneven surface and whether or not the resin film is repelling from the uneven surface can be confirmed, for example, by obtaining SEM image data of the relevant area on the uneven surface.

[0039] In the resin film, the X value may be, for example, any one of 5000 or less, 2000 or less, 1000 or less, 500 or less, 300 or less, 100 or less, and 70 or less. For example, the X value may be any one of 19 to 5000, 25 to 2000, 30 to 1000, 35 to 500, 40 to 300, 45 to 100, and 50 to 70. The larger the X value, the better the groove filling suitability tends to be.

[0040] When other resin films having an X value of 10,000 or more are applied to an uneven surface, even if the upper portions of the convex portions protrude from the other resin film, no effect of suppressing cissing is observed, and the cured product of the other resin film also remains in a state where cissing has occurred.

[0041] In the resin film, it is preferable that the X value of Gc1 is 19 or more and less than 10,000. However, as explained above, the effect of suppressing the resin film from remaining on the top of the convex portion, the effect of suppressing the resin film from protruding, and the effect of suppressing the resin film and its cured product from cissing are all exhibited at a high level, so Gc1 is 1 × 10 4 ~1×10 6 Pa is preferred, and 1×10 5 ~7×10 5 Pa is more preferred.

[0042] In the resin film, Gc300 is not particularly limited as long as the X value is 19 or more and less than 10,000. However, for the same reasons as in the case of Gc1 above, Gc300 is preferably 1 to 30,000 Pa, and may be, for example, 1 to 5,000 Pa or 5,000 to 30,000 Pa.

[0043] The resin film must satisfy both of the above conditions, that is, Gc1 must be 1×10 4 ~1×10 6 Pa, preferably 1 × 10 5 ~7×10 5 Pa, and Gc300 is preferably 1 to 30,000 Pa, 1 to 5,000 Pa, or 5,000 to 30,000 Pa.

[0044] The storage modulus of the resin film can be easily adjusted by adjusting the type or content of the components contained in the resin film, not limited to Gc1 and Gc300. To achieve this, the type or content of the components contained in the composition for forming the resin film can be adjusted. For example, when using the thermosetting resin film-forming composition (III) described below, the storage modulus of the resin film can be easily adjusted by adjusting the type or content of the main components contained in the composition, such as the polymer component (A) and the filler (D), or by adjusting the type or content of the additive (I), such as a rheology control agent, a surfactant, or a silicone oil. For example, when the content of the filler (D) or the additive (I) in the thermosetting resin film and the composition (III) is increased, the X value tends to increase.

[0045] The resin film of this embodiment can be laminated with a support sheet to form a composite sheet, for example, as described below.

[0046] FIG. 1 is a cross-sectional view schematically illustrating an example of a resin film according to one embodiment of the present invention. In addition, the drawings used in the following explanation may show enlarged essential parts for the sake of convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality.

[0047] The resin film 12 shown here has a first release film 151 on one of its surfaces (sometimes referred to as the "first surface" in this specification) 12a, and a second release film 152 on the other surface (sometimes referred to as the "second surface" in this specification) 12b opposite the first surface 12a. Such a resin film 12 is suitable for storage in the form of a roll, for example.

[0048] The calorific value of the first test piece of the resin film 12 is 100 J / g or less. The X value of the second test piece of the resin film 12 is preferably 19 or more and less than 10,000.

[0049] The first release film 151 and the second release film 152 may both be known films. The first release film 151 and the second release film 152 may be the same as each other, or may be different from each other, for example, in that the peeling force required to peel them from the resin film 12 is different from each other.

[0050] 1, either the first release film 151 or the second release film 152 is removed, and the resulting exposed surface becomes the surface to be attached to the uneven surface. Then, the remaining other of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes the surface to be attached to other layers (e.g., a buffer layer, an adhesive layer, etc.) that will form the composite sheet described below.

[0051] Although Figure 1 shows an example in which a release film is provided on both sides (first side 12a, second side 12b) of resin film 12, the release film may be provided on only one side of resin film 12, i.e., only first side 12a or only second side 12b.

[0052] The resin film of the present embodiment contains a resin component, and may or may not contain components other than the resin component. Preferred resin films include, for example, those containing a resin component, a thermosetting component, and a filler, and optionally containing various additives that do not fall into any of these categories (resin component, thermosetting component, and filler) and have the effect of adjusting the storage modulus of the resin film.

[0053] Examples of the additives having the effect of adjusting the storage modulus of the resin film include rheology control agents (thixotropic agents), surfactants, silicone oils, and the like.

[0054] If a resin film protrudes from its original size when it is attached to an object, such as when it is attached to an uneven surface, the resin film in this protruding state can be viewed in a planar view from above, and the maximum length of the line segment connecting two different points on the outer circumference of the resin film at this time can be found.Furthermore, the original width of the resin film (i.e., before it protruded) can be found at the position where it overlaps with the line segment that indicates this maximum length, and the width of the resin film can be subtracted from the maximum length of the line segment to calculate the amount of protrusion of the resin film.

[0055] FIG. 2 is a plan view for schematically explaining the amount of protrusion of a resin film when the planar shape of the resin film is circular. In FIG. 2 and subsequent figures, the same components as those shown in the figures already described are given the same reference numerals as in the figures already described, and detailed description thereof will be omitted.

[0056] The resin film 101 shown here protrudes from its original size when attached to an attachment object 102. The resin film has its original size indicated by the reference numeral 101', which is shown for convenience in order to make it easier to understand the amount of protrusion. The original resin film 101' has a circular planar shape here, but the protruding resin film 101 has a non-circular planar shape. However, this is just an example, and the planar shape of the protruding resin film 101 is not limited to that shown here.

[0057] To find the amount of protrusion of resin film 101, find the maximum value of length D1 of the line segment connecting point 1010a on outer periphery 1010 of resin film 101 and another point 1010b, and then find the value D0 of the initial width of resin film 101' (i.e., before protrusion) at the position where it overlaps with the line segment that indicates this maximum value. The difference between D1 and D0 (D1-D0) is the amount of protrusion. The line segment indicating the maximum value in resin film 101 may pass through the center of the circle in original resin film 101' when viewed in a plane, in which case the width value of original resin film 101' at the position where it overlaps with the line segment indicating this maximum value becomes the diameter of resin film 101'.

[0058] Here, we have explained the amount of resin film protruding when the planar shape of the resin film is circular, with reference to the drawings, but the amount of resin film protruding can also be calculated using a similar method when the planar shape is other than circular.

[0059] The resin film may be composed of one layer (single layer) or two or more layers. When the resin film is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0060] In this specification, not only in the case of the resin film, "multiple layers may be the same or different from one another" means "all layers may be the same, all layers may be different, or only some layers may be the same," and further, "multiple layers are different from one another" means "at least one of the constituent materials and thicknesses of each layer is different from one another."

[0061] The thickness of the resin film is preferably 1 to 100 μm, more preferably 5 to 80 μm, and particularly preferably 5 to 60 μm. When the thickness of the resin film is equal to or greater than the lower limit, the effect of the resin film is enhanced. For example, when a protective film is formed using a resin film, a protective film with higher protective ability can be formed. On the other hand, when the thickness of the resin film is equal to or less than the upper limit, excessive thickness is prevented. Here, "thickness of the resin film" means the thickness of the entire resin film, and for example, the thickness of a resin film consisting of multiple layers means the total thickness of all layers that make up the resin film. In this specification, unless otherwise specified, "thickness" refers to a value expressed as the average of thickness measurements at five randomly selected locations, and can be obtained using a constant pressure thickness measuring device in accordance with JIS K7130.

[0062] <<Resin film-forming composition>> The resin film can be formed using a resin film-forming composition containing its constituent materials. For example, the resin film can be formed by applying the resin film-forming composition to the surface to be formed and drying it as necessary. The ratio of the contents of the components that do not vaporize at room temperature in the resin film-forming composition is usually the same as the ratio of the contents of the components in the resin film. In this specification, "room temperature" means a temperature that is neither particularly cold nor hot, that is, an ordinary temperature, and examples thereof include temperatures of 15 to 25°C.

[0063] A thermosetting resin film can be formed using a composition for forming a thermosetting resin film. In this specification, when a resin film has both thermosetting and energy ray-curable properties, and the contribution of the thermosetting of the resin film to its curing (e.g., formation of a protective film) is greater than the contribution of the energy ray-curing, the resin film is treated as being thermosetting. Conversely, when the contribution of the energy ray-curing of the resin film to its curing is greater than the contribution of the thermosetting, the resin film is treated as being energy ray-curable.

[0064] The resin film-forming composition may be applied by a known method, for example, by using various coaters such as an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, Mayer bar coater, or kiss coater.

[0065] The drying conditions for the resin film-forming composition are not particularly limited. However, when the resin film-forming composition contains a solvent, which will be described later, it is preferable to heat-dry it. The resin film-forming composition containing the solvent is preferably heat-dried, for example, at 70 to 130°C for 10 seconds to 5 minutes. However, the thermosetting resin film-forming composition is preferably heat-dried so as not to thermally cure the composition itself or the thermosetting resin film formed from this composition.

[0066] The thermosetting resin film and the energy ray-curable resin film will be described in more detail below.

[0067] Thermosetting resin film When a thermosetting resin film is cured to form a cured product, particularly when a protective film is formed, the curing conditions are not particularly limited as long as the cured product has a degree of curing that allows it to fully exhibit its functions, and may be appropriately selected depending on the type of thermosetting resin film, the use of the cured product, etc. For example, when forming a protective film, the heating temperature during curing of the thermosetting resin film is preferably 100 to 200°C, more preferably 110 to 170°C, and particularly preferably 120 to 150°C. The heating time during the thermal curing is preferably 0.5 to 5 hours, more preferably 0.5 to 4 hours, and particularly preferably 1 to 4 hours. The thermosetting resin film may be cured while being pressed, and in this case, the pressure applied is preferably 0.1 to 1 MPa.

[0068] <Thermosetting resin film-forming composition> Examples of the composition for forming a thermosetting resin film include a composition for forming a thermosetting resin film (III) (sometimes simply referred to as "composition (III)" in this specification) containing a polymer component (A), a thermosetting component (B), and a filler (D).

[0069] [Polymer component (A)] The polymer component (A) is a polymer compound for imparting film-forming properties, flexibility, etc. to the thermosetting resin film. In this specification, the polymer compound also includes products of polycondensation reactions. The polymer component (A) contained in the composition (III) and the thermosetting resin film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0070] Examples of the polymer component (A) include polyvinyl acetal, acrylic resin, urethane resin, phenoxy resin, silicone resin, saturated polyester resin, and the like. Among these, the polymer component (A) is preferably polyvinyl acetal.

[0071] The polyvinyl acetal in the polymer component (A) may be any known polyvinyl acetal. Of these, preferred polyvinyl acetals include, for example, polyvinyl formal and polyvinyl butyral, with polyvinyl butyral being more preferred. Examples of polyvinyl butyral include those having structural units represented by the following formulas (i)-1, (i)-2, and (i)-3.

[0072] [ka] (In the formula, l, m, and n each independently represents an integer of 1 or more.)

[0073] The weight-average molecular weight (Mw) of the polyvinyl acetal is preferably 5,000 to 200,000, and more preferably 8,000 to 100,000. When the weight-average molecular weight of the polyvinyl acetal is in this range, the following effects are achieved: when a thermosetting resin film is applied to the uneven surface, the fine grooves on the uneven surface are sufficiently filled, and peeling of the protective film from the uneven surface is suppressed (for example, when a thermosetting resin film is applied to the bump-forming surface, the fine grooves on the bump-forming surface are sufficiently filled, and peeling of the protective film from the bump-forming surface is suppressed; the same applies hereinafter); and when a thermosetting resin film is applied to the uneven surface, the thermosetting resin film is suppressed from remaining on the upper parts of the convex portions of the uneven surface (for example, when a thermosetting resin film is applied to the bump-forming surface, the thermosetting resin film is suppressed from remaining on the upper parts of the bumps). The effect of suppressing the thermosetting resin film from remaining on the uneven surface (for example, the effect of suppressing the thermosetting resin film from protruding from its original size on the bump-forming surface when the thermosetting resin film is attached to the bump-forming surface; the same applies below), and the effect of suppressing the thermosetting resin film and its cured product from repelling on the uneven surface (for example, the effect of suppressing the thermosetting resin film and its cured product from repelling on the bump-forming surface when the thermosetting resin film is attached to the bump-forming surface; the same applies below) are further enhanced.

[0074] In this specification, unless otherwise specified, the "weight average molecular weight" is a polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0075] The glass transition temperature (Tg) of the polyvinyl acetal is preferably 40 to 80° C., more preferably 50 to 70° C. When the Tg of the polyvinyl acetal is in this range, when a thermosetting resin film is attached to the uneven surface, the effects of suppressing the thermosetting resin film from remaining on the tops of the convex portions of the uneven surface, suppressing the thermosetting resin film from protruding from the uneven surface, and suppressing the thermosetting resin film and its cured product from repelling on the uneven surface are enhanced.

[0076] The ratio of the three or more monomers constituting the polyvinyl acetal can be selected arbitrarily.

[0077] The acrylic resin in the polymer component (A) may be any known acrylic polymer. The weight-average molecular weight (Mw) of the acrylic resin is preferably 5000 to 1,000,000, and more preferably 8000 to 800,000. When the weight-average molecular weight of the acrylic resin is in this range, when a thermosetting resin film is attached to the uneven surface, the effects of suppressing the thermosetting resin film from remaining on the tops of the convex portions of the uneven surface, suppressing the thermosetting resin film from protruding from the uneven surface, and suppressing repelling of the thermosetting resin film and its cured product on the uneven surface are enhanced.

[0078] The glass transition temperature (Tg) of the acrylic resin is preferably −50 to 70° C., more preferably −30 to 60° C. When the Tg of the acrylic resin is in this range, when the thermosetting resin film is attached to the uneven surface, the effects of suppressing the thermosetting resin film from remaining on the tops of the convex portions of the uneven surface, suppressing the thermosetting resin film from protruding from the uneven surface, and suppressing cissing of the thermosetting resin film and its cured product on the uneven surface are enhanced.

[0079] When an acrylic resin has two or more structural units, the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox equation. The Tg of the monomer from which the structural unit is derived can be calculated using the value listed in the Polymer Data Handbook or the Adhesive Handbook.

[0080] The acrylic resin may be made up of one type of monomer or two or more types of monomers, and when two or more types of monomers are used, the combination and ratio thereof can be selected arbitrarily.

[0081] Examples of acrylic resins include polymers of one or more (meth)acrylic acid esters; A copolymer of two or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like; Examples include copolymers of one or more (meth)acrylic acid esters and one or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like.

[0082] In this specification, the term "(meth)acrylic acid" encompasses both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid. For example, "(meth)acrylate" encompasses both "acrylate" and "methacrylate," and "(meth)acryloyl group" encompasses both "acryloyl group" and "methacryloyl group."

[0083] Examples of the (meth)acrylic acid ester constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and p) (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure and has 1 to 18 carbon atoms, such as isononyl acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate); (meth)acrylic acid cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate; (Meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester; (Meth)acrylic acid cycloalkenyloxyalkyl esters such as (meth)acrylic acid dicyclopentenyloxyethyl ester; (Meth)acrylic acid imide; glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate; hydroxyl group-containing (meth)acrylic acid esters such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; Examples include substituted amino group-containing (meth)acrylic acid esters such as N-methylaminoethyl (meth)acrylate. Here, the term "substituted amino group" refers to a group in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom.

[0084] The acrylic resin may have a functional group capable of bonding to other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, or an isocyanate group. The functional group of the acrylic resin may bond to other compounds via a crosslinking agent (F) described below, or may bond directly to other compounds without the crosslinking agent (F). Bonding of the acrylic resin to other compounds via the functional group tends to improve the reliability of, for example, a package obtained using the thermosetting resin film.

[0085] In composition (III), the ratio of the content of polymer component (A) to the total content of all components other than the solvent (i.e., in the thermosetting resin film, the ratio of the content of polymer component (A) to the total mass of the thermosetting resin film) is preferably 5 to 35 mass%, more preferably 5 to 27 mass%, regardless of the type of polymer component (A).

[0086] [Thermosetting component (B)] The thermosetting component (B) has thermosetting properties and is a component that heat-cures the thermosetting resin film to form a hard cured product. The thermosetting component (B) contained in the composition (III) and the thermosetting resin film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0087] Examples of the thermosetting component (B) include epoxy-based thermosetting resins, polyimide resins, and unsaturated polyester resins. Among these, the thermosetting component (B) is preferably an epoxy-based thermosetting resin.

[0088] (epoxy thermosetting resin) The epoxy thermosetting resin is composed of an epoxy resin (B1) and a thermosetting agent (B2). The epoxy-based thermosetting resin contained in the composition (III) and the thermosetting resin film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0089] Epoxy resin (B1) Examples of the epoxy resin (B1) include known epoxy resins, such as bifunctional or higher functional epoxy compounds, including polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, orthocresol novolac epoxy resins, dicyclopentadiene-type epoxy resins, biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and phenylene skeleton-type epoxy resins.

[0090] The epoxy resin (B1) may be an epoxy resin having an unsaturated hydrocarbon group. Epoxy resins having an unsaturated hydrocarbon group have higher compatibility with acrylic resins than epoxy resins not having an unsaturated hydrocarbon group. Therefore, the use of an epoxy resin having an unsaturated hydrocarbon group tends to improve the reliability of a package obtained using, for example, a thermosetting resin film.

[0091] Examples of epoxy resins having unsaturated hydrocarbon groups include compounds obtained by converting some of the epoxy groups of a polyfunctional epoxy resin into groups having unsaturated hydrocarbon groups. Such compounds can be obtained, for example, by subjecting epoxy groups to an addition reaction with (meth)acrylic acid or a derivative thereof. Furthermore, examples of epoxy resins having an unsaturated hydrocarbon group include compounds in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring or the like constituting the epoxy resin. The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include an ethenyl group (vinyl group), a 2-propenyl group (allyl group), a (meth)acryloyl group, and a (meth)acrylamide group, with an acryloyl group being preferred.

[0092] The number average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoints of the curability of the thermosetting resin film and the strength and heat resistance of the cured product of the thermosetting resin film (for example, a protective film), it is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000. The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1000 g / eq, more preferably 100 to 600 g / eq.

[0093] The epoxy resin (B1) may be used alone or in combination of two or more kinds. When two or more kinds are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0094] Heat hardener (B2) The heat curing agent (B2) functions as a curing agent for the epoxy resin (B1). The thermosetting agent (B2) may be, for example, a compound having two or more functional groups per molecule that can react with an epoxy group. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an anhydride group of an acid group. A phenolic hydroxyl group, an amino group, or an anhydride group of an acid group is preferred, and a phenolic hydroxyl group or an amino group is more preferred.

[0095] Among the heat curing agents (B2), examples of phenolic curing agents having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Among the heat curing agents (B2), examples of amine-based curing agents having an amino group include dicyandiamide (hereinafter sometimes abbreviated as "DICY").

[0096] The heat curing agent (B2) may have an unsaturated hydrocarbon group. Examples of the thermosetting agent (B2) having an unsaturated hydrocarbon group include a compound in which some of the hydroxyl groups of a phenolic resin are substituted with a group having an unsaturated hydrocarbon group, and a compound in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring of a phenolic resin. The unsaturated hydrocarbon group in the heat curing agent (B2) is the same as the unsaturated hydrocarbon group in the epoxy resin having an unsaturated hydrocarbon group described above.

[0097] Of the thermosetting agents (B2), for example, the number average molecular weight of resin components such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000. Of the thermosetting agent (B2), the molecular weight of the non-resin component such as biphenol or dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

[0098] The heat curing agent (B2) may be used alone or in combination of two or more kinds. When two or more kinds are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0099] In the composition (III) and the thermosetting resin film, the content of the thermosetting agent (B2) is preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass, and may be, for example, any of 5 to 150 parts by mass, 10 to 100 parts by mass, and 15 to 75 parts by mass, per 100 parts by mass of the epoxy resin (B1). When the content of the thermosetting agent (B2) is equal to or greater than the lower limit, curing of the thermosetting resin film proceeds more easily. When the content of the thermosetting agent (B2) is equal to or less than the upper limit, the moisture absorption rate of the thermosetting resin film is reduced, thereby further improving the reliability of, for example, a package obtained using the thermosetting resin film.

[0100] In composition (III), the ratio of the content of the thermosetting component (B) (e.g., the total content of the epoxy resin (B1) and the thermosetting agent (B2)) to the total content of all components other than the solvent (i.e., the ratio of the content of the thermosetting component (B) in the thermosetting resin film to the total mass of the thermosetting resin film) is preferably 10 to 75 mass%, more preferably 15 to 73 mass%, and may be any of 35 to 70 mass% and 55 to 70 mass%. When the ratio is within this range, when the thermosetting resin film is applied to the uneven surface, the effect of filling the fine grooves on the uneven surface and suppressing poor curing of the resin film, the effect of suppressing the thermosetting resin film remaining on the upper parts of the convex portions of the uneven surface, the effect of suppressing protrusion of the thermosetting resin film on the uneven surface, and the effect of suppressing cissing of the thermosetting resin film and its cured product on the uneven surface are enhanced, and a hard cured product (e.g., a protective film) can be formed. In particular, the lower the content ratio of the thermosetting component (B) relative to the total mass of the resin film, the easier it is to reduce the calorific value of the first test piece, and the more effectively it is possible to suppress poor curing of the resin film. Furthermore, the higher the content of the thermosetting component (B) relative to the total mass of the resin film, the more effectively the groove-filling suitability can be improved. This is presumably because the thermosetting component (B) before curing has a low molecular weight and exhibits excellent fluidity. Furthermore, in order to obtain such effects more significantly, the content of the thermosetting component (B) may be adjusted appropriately depending on the type of the polymer component (A).

[0101] [Filling material (D)] The X value can be more easily adjusted by adjusting the amount of filler (D) in the composition (III) and the thermosetting resin film. By increasing the amount of filler (D) in the composition (III) and the thermosetting resin film, the content of the thermosetting component can be adjusted to be lower, making it easy to reduce the heat release value of the first test piece. The use of a thermosetting resin film containing filler (D) can also reduce the moisture absorption rate of the cured product of the thermosetting resin film (e.g., a protective film) and improve heat dissipation.

[0102] The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler. Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride, etc.; beads obtained by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; glass fibers, etc. Among these, the inorganic filler is preferably silica or alumina.

[0103] The filler (D) contained in the composition (III) and the thermosetting resin film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0104] In composition (III), the ratio of the content of filler (D) to the total content of all components other than the solvent (i.e., the ratio of the content of filler (D) in the thermosetting resin film to the total mass of the thermosetting resin film) is preferably 10 to 65% by mass, more preferably 15 to 55% by mass, and may be, for example, 15 to 40% by mass, 15 to 30% by mass, 30 to 55% by mass, or 40 to 55% by mass. When the ratio is within this range, when the thermosetting resin film is attached to the uneven surface, the effect of filling the fine grooves on the uneven surface and suppressing poor curing of the resin film, the effect of suppressing the thermosetting resin film remaining on the upper parts of the convex portions of the uneven surface, the effect of suppressing protrusion of the thermosetting resin film on the uneven surface, and the effect of suppressing cissing of the thermosetting resin film and its cured product on the uneven surface are enhanced.

[0105] [Additives (I)] The composition (III) and the thermosetting resin film may contain an additive (I). Examples of the additive (I) include a component for adjusting the X value. Among these, examples of the additive (I) that are preferable in terms of making it easier to adjust the X value include rheology control agents, surfactants, and silicone oils.

[0106] More specifically, examples of the rheology control agent include polyhydroxycarboxylic acid esters, polycarboxylic acids, and polyamide resins. Examples of the surfactant include modified siloxane and acrylic polymer. Examples of the silicone oil include aralkyl-modified silicone oil and modified polydimethylsiloxane, and examples of the modifying group include aralkyl groups; polar groups such as hydroxy groups; and groups having an unsaturated bond such as vinyl groups and phenyl groups.

[0107] In addition to the additives (I) mentioned above, various other general-purpose additives such as plasticizers, antistatic agents, antioxidants, gettering agents, ultraviolet absorbers, and tackifiers may also be used.

[0108] The additive (I) contained in the composition (III) and the thermosetting resin film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0109] The content of the additive (I) in the composition (III) and the thermosetting resin film is not particularly limited, and can be adjusted appropriately depending on the type and purpose. For example, when the purpose is to adjust the X value, the ratio of the content of additive (I) in composition (III) to the total content of all components other than the solvent (i.e., the ratio of the content of additive (I) in the thermosetting resin film to the total mass of the thermosetting resin film) is preferably 0.5 to 10 mass%, more preferably 0.5 to 7 mass%, and even more preferably 0.5 to 5 mass%.

[0110] [Curing accelerator (C)] The composition (III) and the thermosetting resin film may contain a curing accelerator (C), which is a component for adjusting the curing rate of the composition (III). Preferred examples of the curing accelerator (C) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines (phosphines in which one or more hydrogen atoms are substituted with organic groups) such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

[0111] The curing accelerator (C) contained in the composition (III) and the thermosetting resin film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[0112] When the curing accelerator (C) is used, the content of the curing accelerator (C) in the composition (III) and the thermosetting resin film is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the thermosetting component (B). When the content of the curing accelerator (C) is equal to or greater than the lower limit, the effects of using the curing accelerator (C) are more pronounced. When the content of the curing accelerator (C) is equal to or less than the upper limit, for example, the effect of suppressing the highly polar curing accelerator (C) from migrating and segregating to the adhesive interface with the adherend under high temperature and high humidity conditions in the thermosetting resin film is enhanced, thereby further improving the reliability of the package obtained using the thermosetting resin film.

[0113] [Coupling agent (E)] The composition (III) and the thermosetting resin film may contain a coupling agent (E). By using a coupling agent (E) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesiveness and adhesion of the thermosetting resin film to an adherend can be improved. Furthermore, by using the coupling agent (E), the water resistance of the cured product of the thermosetting resin film (e.g., a protective film) can be improved without impairing the heat resistance.

[0114] The coupling agent (E) is preferably a compound having a functional group capable of reacting with the functional group of the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent. Preferred examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2- Examples of such silanes include (aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazole silane.

[0115] The coupling agent (E) contained in the composition (III) and the thermosetting resin film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[0116] When a coupling agent (E) is used, the content of the coupling agent (E) in the composition (III) and the thermosetting resin film is preferably 0.03 to 10 parts by mass, more preferably 0.05 to 6 parts by mass, and particularly preferably 0.1 to 3 parts by mass, per 100 parts by mass of the total content of the polymer component (A) and the thermosetting component (B). When the content of the coupling agent (E) is equal to or greater than the lower limit, the effects of using the coupling agent (E), such as improved dispersibility of the filler (D) in the resin and improved adhesion of the thermosetting resin film to the substrate, are more significantly achieved. When the content of the coupling agent (E) is equal to or less than the upper limit, outgassing is further suppressed.

[0117] [Crosslinker (F)] When the polymer component (A) has a functional group capable of bonding with other compounds, such as a vinyl group, (meth)acryloyl group, amino group, hydroxyl group, carboxyl group, or isocyanate group, the composition (III) and the thermosetting resin film may contain a crosslinking agent (F). The crosslinking agent (F) is a component that bonds the functional group in the polymer component (A) with other compounds to form a crosslink, and by crosslinking in this manner, the initial adhesive strength and cohesive strength of the thermosetting resin film can be adjusted.

[0118] Examples of the crosslinking agent (F) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridinyl group).

[0119] Examples of the organic polyisocyanate compound include aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, and alicyclic polyisocyanate compounds (hereinafter, these compounds may be collectively referred to as "aromatic polyisocyanate compounds, etc."); trimers, isocyanurates, and adducts of the aromatic polyisocyanate compounds, etc.; and isocyanate-terminated urethane prepolymers obtained by reacting the aromatic polyisocyanate compounds, etc. with polyol compounds. The "adduct" refers to a reaction product of the aromatic polyisocyanate compound, aliphatic polyisocyanate compound, or alicyclic polyisocyanate compound with a low-molecular-weight active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, or castor oil. Examples of the adduct include the xylylene diisocyanate adduct of trimethylolpropane, as described below. Furthermore, the term "isocyanate-terminated urethane prepolymer" refers to a prepolymer having a urethane bond and an isocyanate group at the end of the molecule.

[0120] More specific examples of the organic polyisocyanate compound include 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylylene diisocyanate; diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; a compound in which one or more of tolylene diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are added to all or some of the hydroxyl groups of a polyol such as trimethylolpropane; lysine diisocyanate, and the like.

[0121] Examples of the organic polyvalent imine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, and N,N'-toluene-2,4-bis(1-aziridinecarboxamide)triethylenemelamine.

[0122] When an organic polyisocyanate compound is used as the crosslinking agent (F), it is preferable to use a hydroxyl group-containing polymer as the polymer component (A). When the crosslinking agent (F) has an isocyanate group and the polymer component (A) has a hydroxyl group, a crosslinked structure can be easily introduced into the thermosetting resin film by the reaction between the crosslinking agent (F) and the polymer component (A).

[0123] The crosslinking agent (F) contained in the composition (III) and the thermosetting resin film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0124] When a crosslinking agent (F) is used, the content of the crosslinking agent (F) in the composition (III) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass, per 100 parts by mass of the polymer component (A). When the content of the crosslinking agent (F) is equal to or greater than the lower limit, the effect of using the crosslinking agent (F) is more pronounced. When the content of the crosslinking agent (F) is equal to or less than the upper limit, excessive use of the crosslinking agent (F) is suppressed.

[0125] [Other ingredients] The composition (III) and the thermosetting resin film may contain other components that do not fall under any of the above-mentioned polymer component (A), thermosetting component (B), filler (D), additive (I), curing accelerator (C), coupling agent (E), and crosslinking agent (F), as long as the effects of the present invention are not impaired. Examples of the other components include an energy ray curable resin and a photopolymerization initiator.

[0126] The other components contained in the composition (III) and the thermosetting resin film may be one type only or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily. The contents of the composition (III) and the other components in the thermosetting resin film are not particularly limited and may be appropriately selected depending on the purpose.

[0127] [solvent] Composition (III) preferably further contains a solvent, which makes composition (III) easier to handle. The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The composition (III) may contain only one type of solvent, or two or more types of solvents. When two or more types of solvents are contained, the combination and ratio thereof can be selected arbitrarily.

[0128] A more preferred example of the solvent contained in composition (III) is methyl ethyl ketone, etc., from the viewpoint of enabling the components contained in composition (III) to be mixed more uniformly.

[0129] The content of the solvent in the composition (III) is not particularly limited, and may be appropriately selected depending on, for example, the types of components other than the solvent.

[0130] <Method for producing a thermosetting resin film-forming composition> A thermosetting resin film-forming composition such as composition (III) can be obtained by blending the components that constitute the composition. The order of addition of the components when blending is not particularly limited, and two or more components may be added simultaneously. The method for mixing the components during blending is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer or stirring blades, a method of mixing using a mixer, or a method of mixing by adding ultrasound. The temperature and time for adding and mixing each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. A temperature of 15 to 30°C is preferred.

[0131] An example of a preferred resin film of this embodiment is a thermosetting resin film, the resin film before thermal curing is used as a first test piece, and the first test piece is analyzed by differential scanning calorimetry (DSC) under a constant temperature rise condition of a temperature rise rate of 10°C / min, and the calorific value in the range of 100 to 300°C is any one of 100 J / g or less, 10 to 100 J / g, 50 to 90 J / g, and 60 to 80 J / g; The resin film contains a polymer component (A) and a thermosetting component (B), the content of the polymer component (A) in the resin film is either 5 to 35% by mass or 5 to 27% by mass relative to the total mass of the resin film; The resin film may have a content of the thermosetting component (B) of 10 to 75 mass %, 15 to 73 mass %, or 35 to 70 mass % relative to the total mass of the resin film.

[0132] An example of a preferred resin film of this embodiment is a thermosetting resin film, the resin film before thermal curing is used as a first test piece, and the first test piece is analyzed by differential scanning calorimetry (DSC) under a constant temperature rise condition of a temperature rise rate of 10°C / min, and the calorific value in the range of 100 to 300°C is any one of 100 J / g or less, 10 to 100 J / g, 50 to 90 J / g, and 60 to 80 J / g; the resin film contains a polymer component (A), a thermosetting component (B), and a filler (D), the content of the polymer component (A) in the resin film is either 5 to 35% by mass or 5 to 27% by mass relative to the total mass of the resin film; the content of the thermosetting component (B) in the resin film is any one of 10 to 75 mass%, 15 to 73 mass%, and 35 to 70 mass% relative to the total mass of the resin film; The resin film may have a content of the filler (D) of 10 to 65% by mass or 15 to 55% by mass relative to the total mass of the resin film.

[0133] Another example of a preferable resin film of the present embodiment is a thermosetting resin film, the resin film before thermal curing is used as a first test piece, and the first test piece is analyzed by differential scanning calorimetry (DSC) under a constant temperature rise condition of a temperature rise rate of 10°C / min, and the calorific value in the range of 100 to 300°C is any one of 100 J / g or less, 10 to 100 J / g, 50 to 90 J / g, and 60 to 80 J / g; the X value is any one of 19 or more and less than 10,000, 19 to 5,000, 25 to 2,000, 30 to 1,000, 35 to 500, 40 to 300, 45 to 100, and 50 to 70; the resin film contains a polymer component (A), a thermosetting component (B), a filler (D), and an additive (I), the content of the polymer component (A) in the resin film is either 5 to 35% by mass or 5 to 27% by mass relative to the total mass of the resin film; the content of the thermosetting component (B) in the resin film is any one of 10 to 75 mass%, 15 to 73 mass%, and 35 to 70 mass% relative to the total mass of the resin film; the content of the filler (D) in the resin film is either 10 to 65 mass% or 15 to 55 mass% relative to the total mass of the resin film; Examples of the resin film include a resin film in which the content of the additive (I) relative to the total mass of the resin film is any one of 0.5 to 10 mass %, 0.5 to 7 mass %, and 0.5 to 5 mass %.

[0134] ◇Composite sheet A composite sheet according to one embodiment of the present invention comprises a support sheet and a resin film provided on one side of the support sheet, the resin film being the resin film according to one embodiment of the present invention described above. As described above, by using the composite sheet of this embodiment, the resin film can be adhered well to the uneven surface of the object to which it is to be attached, and at this time, the fine grooves on the uneven surface can be filled, thereby suppressing poor curing of the resin film.

[0135] In this specification, when the resin film is used to form the first protective film, the composite sheet is referred to as a "sheet for forming the first protective film," and the support sheet in the sheet for forming the first protective film is referred to as a "first support sheet." On the other hand, to provide a second protective film on the surface (back surface) opposite to the bump-formed surface of the semiconductor wafer or semiconductor chip, a second protective film-forming sheet is used, which is configured to include a second protective film-forming film for forming the second protective film. Examples of the second protective film-forming sheet include a sheet configured to include a dicing sheet and a second protective film-forming film provided on the dicing sheet. When the dicing sheet includes the same material as the support sheet, this support sheet is referred to as a "second support sheet." Similarly, for example, if the first support sheet has a substrate and an adhesive layer, these will be referred to as the "first substrate" and the "first adhesive layer," and if the second support sheet has a substrate and an adhesive layer, these will be referred to as the "second substrate" and the "second adhesive layer."

[0136] FIG. 3 is a cross-sectional view schematically showing an example of the composite sheet of the present embodiment. The composite sheet 1 shown here is composed of a support sheet 10 and a resin film 12 provided on one side 10a of the support sheet 10 (sometimes referred to as the "first side" in this specification). The support sheet 10 is composed of a substrate 11, a buffer layer 13 provided on one surface 11a of the substrate 11 (sometimes referred to as the "first surface" in this specification), and an adhesive layer 14 provided on the surface 13a of the buffer layer 13 opposite the substrate 11 side (sometimes referred to as the "first surface" in this specification). That is, the composite sheet 1 is constructed by laminating a substrate 11, a buffer layer 13, an adhesive layer 14, and a resin film 12 in this order in the thickness direction. The adhesive layer 14 is the outermost layer on one side (the side of the resin film 12) of the support sheet 10, and the side opposite to the buffer layer 13 side (sometimes referred to as the "first side" in this specification) 14a is the same as the first side 10a of the support sheet 10.

[0137] In the composite sheet 1 , the buffer layer 13 and the adhesive layer 14 are both disposed between the substrate 11 and the resin film 12 .

[0138] The resin film 12 is the resin film according to one embodiment of the present invention described above. The surface (first surface) 12a of the resin film 12 opposite to the buffer layer 13 side is the surface to be attached to the uneven surface of the resin film 12 (in other words, the composite sheet 1).

[0139] The composite sheet of this embodiment is not limited to that shown in FIG. 3, and some of the components shown in FIG. 3 may be modified, deleted, or added, as long as the effects of the present invention are not impaired.

[0140] For example, in the composite sheet of this embodiment, in addition to the support sheet comprising the above-mentioned substrate, buffer layer, and adhesive layer, examples of the support sheet include a support sheet comprising only a substrate; a support sheet comprising a substrate and an adhesive layer provided on one side of the substrate; and a support sheet comprising a substrate and a buffer layer provided on one side of the substrate. When the support sheet includes a substrate and a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is disposed between the substrate and the resin film in the composite sheet. When the support sheet includes a substrate and a buffer layer, the buffer layer is disposed between the substrate and the resin film in the composite sheet. Of these, the support sheet is more preferably one comprising the above-mentioned substrate, buffer layer, and adhesive layer.

[0141] For example, in the composite sheet of this embodiment, the support sheet (support sheet 10 in the composite sheet 1 shown in Figure 3) may have an adhesive layer between the substrate (substrate 11 in the composite sheet 1 shown in Figure 3) and the buffer layer (buffer layer 13 in the composite sheet 1 shown in Figure 3). The adhesion layer improves the adhesion between the substrate and the buffer layer and highly suppresses peeling between the substrate and the buffer layer in the composite sheet, so that the composite sheet having the adhesion layer can more stably maintain the laminated structure of the substrate, adhesion layer, and buffer layer during use. The adhesive layer is in the form of a sheet or a film. A preferred adhesive layer is, for example, one containing an ethylene-vinyl acetate copolymer resin (EVA).

[0142] For example, the composite sheet of this embodiment may have a release film on the outermost layer (resin film 12 in the composite sheet 1 shown in FIG. 3) on the side opposite to the substrate. Next, each layer constituting the composite sheet of this embodiment will be described.

[0143] ◎Base material The substrate is in the form of a sheet or film, and examples of the constituent materials thereof include various resins. Examples of the resin include polyethylenes such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene-based copolymers (copolymers obtained using ethylene as a monomer) such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer; and vinyl chloride-based resins (copolymers obtained using vinyl chloride as a monomer) such as polyvinyl chloride and vinyl chloride copolymer. resins containing aromatic rings); polystyrene; polycycloolefin; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and wholly aromatic polyesters in which all structural units have aromatic cyclic groups; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxides; polyphenylene sulfides; polysulfones; and polyether ketones. Further, examples of the resin include polymer alloys such as mixtures of the polyester and other resins. The polymer alloys of the polyester and other resins preferably contain a relatively small amount of resin other than polyester. Examples of the resin include crosslinked resins in which one or more of the resins exemplified above are crosslinked; and modified resins such as ionomers using one or more of the resins exemplified above.

[0144] The resin constituting the substrate may be one type only, or two or more types, and when two or more types are used, the combination and ratio thereof can be selected arbitrarily.

[0145] The substrate may be a single layer (single layer) or may be a multi-layer structure of two or more layers. If the substrate is a multi-layer structure, the multi-layer structure may be the same or different from each other, and the combination of the multi-layer structure is not particularly limited.

[0146] The thickness of the substrate is preferably 5 to 1000 μm, more preferably 10 to 500 μm, further preferably 15 to 300 μm, and particularly preferably 20 to 180 μm. Here, the "thickness of the substrate" means the thickness of the entire substrate, and for example, the thickness of a substrate consisting of multiple layers means the total thickness of all layers that make up the substrate.

[0147] The substrate preferably has a high thickness accuracy, i.e., a thickness variation that is suppressed regardless of the location. Among the above-mentioned constituent materials, examples of materials that can be used to form a substrate with such a high thickness accuracy include polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, and ethylene-vinyl acetate copolymer.

[0148] In addition to the main constituent materials such as the resin, the substrate may contain various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, and softeners (plasticizers).

[0149] The substrate may be transparent or opaque, may be colored according to the purpose, or may have other layers vapor-deposited thereon. When the resin film is energy ray curable, the substrate is preferably one that transmits energy rays.

[0150] The substrate can be produced by a known method. For example, a substrate containing a resin can be produced by molding a resin composition containing the resin.

[0151] ◎Buffer layer The buffer layer is in the form of a sheet or film and has a buffering effect against forces applied to the buffer layer and layers adjacent thereto. Here, examples of "layers adjacent to the buffer layer" include the resin film, a layer corresponding to a cured product thereof (e.g., a protective film such as the first protective film), and a pressure-sensitive adhesive layer.

[0152] The constituent material of the buffer layer is not particularly limited.

[0153] A preferred buffer layer is, for example, one containing urethane (meth)acrylate.

[0154] As in the case of the resin film described above, strain is generated in a test piece of a buffer layer having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz, and the storage modulus of the test piece is measured. When the storage modulus of the test piece when the strain of the test piece is 300% is taken as Gb300, it is preferable that Gb300 is equal to or greater than Gc300 (Gb300≧Gc300). By using the composite sheet that satisfies these conditions and attaching the resin film to an uneven surface, the upper parts of the convex portions of the uneven surface (for example, bumps on a semiconductor wafer) can more easily penetrate the resin film.

[0155] As described above, when a test piece of the buffer layer is strained in the range of 0.01% to 1000% and the storage modulus Gb of the test piece is measured, and a test piece of the resin film is strained in the range of 0.01% to 1000% and the storage modulus Gc of the test piece is measured, and Gb and Gc are compared for the same strain, it is more preferable that Gb is equal to or greater than Gc (Gb≧Gc) over the entire strain range of 0.01% to 1000%, and even more preferable that Gb is equal to or greater than Gc over the entire strain range of 10% to 1000%. By using the composite sheet that satisfies these conditions and attaching the resin film to an uneven surface, the upper parts of the convex portions of the uneven surface (e.g., bumps on a semiconductor wafer) can more easily penetrate the resin film.

[0156] The buffer layer may consist of one layer (single layer) or two or more layers. When it consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0157] The thickness of the buffer layer is preferably 150 to 1000 μm, more preferably 150 to 800 μm, further preferably 200 to 600 μm, and particularly preferably 250 to 500 μm. Here, the "thickness of the buffer layer" means the thickness of the entire buffer layer, and for example, the thickness of a buffer layer consisting of multiple layers means the total thickness of all layers that make up the buffer layer.

[0158] <<Composition for forming buffer layer>> The buffer layer can be formed using a buffer layer-forming composition containing the constituent materials of the buffer layer, such as the resin. For example, the buffer layer can be formed at the desired location by extruding the buffer layer-forming composition onto the surface on which the buffer layer is to be formed. A more specific method for forming the buffer layer will be described in detail later, along with methods for forming other layers. The ratio of the contents of the components that do not vaporize at room temperature in the buffer layer-forming composition is usually the same as the ratio of the contents of the components of the buffer layer.

[0159] <Buffer layer forming composition (V)> The buffer layer-forming composition may be, for example, a buffer layer-forming composition (V) containing urethane (meth)acrylate.

[0160] The content of the urethane (meth)acrylate in the buffer layer-forming composition (V) and the buffer layer is preferably 80 to 100% by mass.

[0161] [Other ingredients] The buffer layer-forming composition (V) and the buffer layer may contain components other than the urethane (meth)acrylate, as long as the effects of the present invention are not impaired. The other components are not particularly limited and can be appropriately selected depending on the purpose.

[0162] The other components contained in the buffer layer-forming composition (V) and the buffer layer may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily. The contents of the buffer layer-forming composition (V) and the other components of the buffer layer are not particularly limited and may be appropriately selected depending on the purpose.

[0163] ◎Adhesive layer The pressure-sensitive adhesive layer is in the form of a sheet or film and contains a pressure-sensitive adhesive. Examples of the adhesive include adhesive resins such as acrylic resins, urethane resins, rubber-based resins, silicone resins, epoxy-based resins, polyvinyl ethers, polycarbonates, and ester-based resins, with acrylic resins being preferred.

[0164] In this specification, the term "adhesive resin" includes both a resin having adhesive properties and a resin having adhesive properties. For example, the adhesive resin includes not only resins that are adhesive by themselves, but also resins that become adhesive when used in combination with other components such as additives, and resins that become adhesive in the presence of a trigger such as heat or water.

[0165] The adhesive layer may consist of one layer (single layer), or may consist of two or more layers. When it consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0166] The thickness of the pressure-sensitive adhesive layer is preferably 10 to 180 μm, more preferably 30 to 120 μm, and particularly preferably 40 to 80 μm. When the thickness of the pressure-sensitive adhesive layer is equal to or greater than the lower limit, the effect of providing the pressure-sensitive adhesive layer is more pronounced. When the thickness of the pressure-sensitive adhesive layer is equal to or less than the upper limit, the support sheet can be made thinner. Here, "thickness of the adhesive layer" means the thickness of the entire adhesive layer, and for example, the thickness of an adhesive layer consisting of multiple layers means the total thickness of all layers that make up the adhesive layer.

[0167] The adhesive layer may be formed using an energy ray-curable adhesive or a non-energy ray-curable adhesive. That is, the adhesive layer may be either energy ray-curable or non-energy ray-curable. The energy ray-curable adhesive layer can easily adjust its physical properties before and after curing. For example, by curing the energy ray-curable adhesive layer before picking up the semiconductor chip with the first protective film described below, the semiconductor chip with the first protective film can be more easily picked up.

[0168] <<Adhesive composition>> The pressure-sensitive adhesive layer can be formed using a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive. For example, the pressure-sensitive adhesive composition can be applied to a surface on which the pressure-sensitive adhesive layer is to be formed, and then dried as necessary to form the pressure-sensitive adhesive layer at the desired location. The ratio of the contents of the components that do not vaporize at room temperature in the pressure-sensitive adhesive composition is usually the same as the ratio of the contents of the components in the pressure-sensitive adhesive layer.

[0169] The pressure-sensitive adhesive composition can be applied, for example, by the same method as in the case of applying the resin film-forming composition described above.

[0170] The drying conditions for the pressure-sensitive adhesive composition are not particularly limited. When the pressure-sensitive adhesive composition contains a solvent described below, it is preferably dried by heating. The pressure-sensitive adhesive composition containing the solvent is preferably dried, for example, at 70 to 130°C for 10 seconds to 5 minutes.

[0171] When a pressure-sensitive adhesive layer is provided on a substrate or a buffer layer, for example, a pressure-sensitive adhesive composition may be applied to the substrate or the buffer layer and dried as necessary to laminate the pressure-sensitive adhesive layer on the substrate or the buffer layer. When a pressure-sensitive adhesive layer is provided on a substrate or the buffer layer, for example, a pressure-sensitive adhesive composition may be applied to a release film and dried as necessary to form a pressure-sensitive adhesive layer on the release film, and the exposed surface of this pressure-sensitive adhesive layer may be attached to one surface of the substrate or the buffer layer to laminate the pressure-sensitive adhesive layer on the substrate or the buffer layer. In this case, the release film may be removed at any time during the manufacturing process or during the use of the composite sheet.

[0172] When the adhesive layer is energy ray-curable, examples of the energy ray-curable adhesive composition include adhesive composition (I-1) containing a non-energy ray-curable adhesive resin (I-1a) (hereinafter sometimes abbreviated as "adhesive resin (I-1a)") and an energy ray-curable compound; adhesive composition (I-2) containing an energy ray-curable adhesive resin (I-2a) (hereinafter sometimes abbreviated as "adhesive resin (I-2a)") in which an unsaturated group has been introduced into the side chain of the adhesive resin (I-1a); adhesive composition (I-3) containing the adhesive resin (I-2a) and an energy ray-curable low molecular weight compound; and the like.

[0173] Examples of the pressure-sensitive adhesive composition (I-1), pressure-sensitive adhesive composition (I-2), and pressure-sensitive adhesive composition (I-3) include the first pressure-sensitive adhesive composition (I-1), first pressure-sensitive adhesive composition (I-2), and first pressure-sensitive adhesive composition (I-3) described in paragraphs 0045 to 0105 of WO 2017 / 078047.

[0174] When the pressure-sensitive adhesive layer is non-energy ray curable, examples of the non-energy ray curable pressure-sensitive adhesive composition include the pressure-sensitive adhesive composition (I-4) containing the pressure-sensitive adhesive resin (I-1a).

[0175] <<Method of manufacturing pressure-sensitive adhesive composition>> The pressure-sensitive adhesive compositions such as pressure-sensitive adhesive compositions (I-1) to (I-4) can be obtained by blending the pressure-sensitive adhesive and, if necessary, components other than the pressure-sensitive adhesive, for constituting the pressure-sensitive adhesive composition. The order of addition of the components when blending is not particularly limited, and two or more components may be added simultaneously. The method for mixing the components during blending is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer or stirring blades, a method of mixing using a mixer, or a method of mixing by adding ultrasound. The temperature and time for adding and mixing each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. A temperature of 15 to 30°C is preferred.

[0176] ◎Resin film The resin film in the composite sheet of this embodiment is the same as that described above, and therefore a detailed description thereof will be omitted here.

[0177] An example of a preferred composite sheet of the present embodiment is a composite sheet including a support sheet and a resin film provided on one surface of the support sheet, the support sheet comprises a substrate, a buffer layer provided on one surface of the substrate, and a pressure-sensitive adhesive layer provided on the surface of the buffer layer opposite to the substrate side, the buffer layer and the pressure-sensitive adhesive layer being disposed between the substrate and the resin film; the resin film is a thermosetting resin film, the resin film before thermal curing is used as a first test piece, and the first test piece is analyzed by differential scanning calorimetry (DSC) under a constant temperature rise condition of a temperature rise rate of 10°C / min, and the calorific value in the range of 100 to 300°C is any one of 100 J / g or less, 10 to 100 J / g, 50 to 90 J / g, and 60 to 80 J / g; The resin film contains a polymer component (A) and a thermosetting component (B), the content of the polymer component (A) in the resin film is either 5 to 35% by mass or 5 to 27% by mass relative to the total mass of the resin film; Examples of the composite sheet include those in which the content of the thermosetting component (B) in the resin film relative to the total mass of the resin film is any one of 10 to 75 mass %, 15 to 73 mass %, and 35 to 70 mass %.

[0178] Another example of a preferred composite sheet of the present embodiment is a composite sheet including a support sheet and a resin film provided on one surface of the support sheet, the support sheet comprises a substrate, a buffer layer provided on one surface of the substrate, and a pressure-sensitive adhesive layer provided on the surface of the buffer layer opposite to the substrate side, the buffer layer and the pressure-sensitive adhesive layer being disposed between the substrate and the resin film; the resin film is a thermosetting resin film, the resin film before thermal curing is used as a first test piece, and the first test piece is analyzed by differential scanning calorimetry (DSC) under a constant temperature rise condition of a temperature rise rate of 10°C / min, and the calorific value in the range of 100 to 300°C is any one of 100 J / g or less, 10 to 100 J / g, 50 to 90 J / g, and 60 to 80 J / g; the resin film contains a polymer component (A), a thermosetting component (B), and a filler (D), the content of the polymer component (A) in the resin film is either 5 to 35% by mass or 5 to 27% by mass relative to the total mass of the resin film; the content of the thermosetting component (B) in the resin film is any one of 10 to 75 mass%, 15 to 73 mass%, and 35 to 70 mass% relative to the total mass of the resin film; The resin film may have a content of the filler (D) of 10 to 65% by mass or 15 to 55% by mass relative to the total mass of the resin film. , and composite sheets.

[0179] Yet another example of a preferable composite sheet of the present embodiment is a composite sheet including a support sheet and a resin film provided on one surface of the support sheet, the support sheet comprises a substrate, a buffer layer provided on one surface of the substrate, and a pressure-sensitive adhesive layer provided on the surface of the buffer layer opposite to the substrate side, the buffer layer and the pressure-sensitive adhesive layer being disposed between the substrate and the resin film; the resin film is a thermosetting resin film, the resin film before heat curing is used as a first test piece, and the first test piece is analyzed by differential scanning calorimetry (DSC) under a constant temperature rise condition of a temperature rise rate of 10°C / min, and the calorific value in the range of 100 to 300°C is one of 100 J / g or less, 10 to 100 J / g, 50 to 90 J / g, or 60 to 80 J / g; the X value is any one of 19 or more and less than 10,000, 19 to 5,000, 25 to 2,000, 30 to 1,000, 35 to 500, 40 to 300, 45 to 100, and 50 to 70; the resin film contains a polymer component (A), a thermosetting component (B), a filler (D), and an additive (I), the content of the polymer component (A) in the resin film is either 5 to 35% by mass or 5 to 27% by mass relative to the total mass of the resin film; the content of the thermosetting component (B) in the resin film is any one of 10 to 75 mass%, 15 to 73 mass%, and 35 to 70 mass% relative to the total mass of the resin film; the content of the filler (D) in the resin film is either 10 to 65 mass% or 15 to 55 mass% relative to the total mass of the resin film; Examples of the composite sheet include those in which the content of the additive (I) in the resin film relative to the total mass of the resin film is any one of 0.5 to 10 mass %, 0.5 to 7 mass %, and 0.5 to 5 mass %.

[0180] ◇Composite sheet manufacturing method The composite sheet can be produced by laminating the above-mentioned layers in order so that they are in the corresponding positional relationship. The method for forming each layer is as described above.

[0181] For example, a composite sheet having a substrate, a buffer layer, a pressure-sensitive adhesive layer, and a resin film laminated in this order in the thickness direction can be produced by the method described below. That is, a buffer layer is laminated on the substrate by extrusion molding a buffer layer-forming composition onto the substrate. The above-mentioned pressure-sensitive adhesive composition is applied to the release-treated surface of a release film, and dried as necessary to laminate a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer on the release film is then bonded to the buffer layer on the substrate, thereby obtaining a laminated sheet with a release film, in which the substrate, buffer layer, pressure-sensitive adhesive layer, and release film are laminated in this order in the thickness direction. Separately, the above-mentioned resin film-forming composition is applied to the release-treated surface of a release film, and dried as necessary to laminate a resin film. The release film is then removed from the laminated sheet obtained above, and the newly exposed surface of the adhesive layer is bonded to the exposed surface of the resin film on the release film, thereby obtaining a composite sheet in which the substrate, buffer layer, adhesive layer, resin film, and release film are laminated in this order in the thickness direction. The release film on the resin film can be removed when the composite sheet is to be used.

[0182] A composite sheet having layers other than the above-mentioned layers can be produced by appropriately adding either or both of the steps of forming and laminating the other layers to the above-mentioned production method so that the lamination positions of the other layers are appropriate.

[0183] ◇ Manufacturing method for semiconductor chips with first protective film (method for using resin film and composite sheet) As explained above, the resin film of this embodiment has excellent properties in that, when applied to the uneven surface of an object, it can penetrate the convex portions, exposing their upper portions, while covering the entire uneven surface. That is, the resin film of this embodiment is suitable for application to the uneven surface of an object having an uneven surface. Furthermore, if the uneven surface has fine grooves, the resin film can fill these grooves, thereby filling the grooves with a protective film. Furthermore, since the resin film fills the fine grooves on the uneven surface and prevents the resin film from being poorly cured after being heat-treated for curing, it is possible to prevent processing debris that may be generated when the protective film is cut from adhering to the semiconductor chip or wafer. The resin film of this embodiment is suitable for protecting the uneven surface and side surfaces of a semiconductor chip, and is particularly suitable for use in manufacturing a semiconductor chip with a first protective film, which includes a semiconductor chip and a first protective film provided on the side surfaces and the surface having bumps (bump-forming surface) of the semiconductor chip. In this case, the uneven surface is the bump-forming surface of the semiconductor chip, and the convex portions are the bumps. Furthermore, the concave portions include grooves on the bump-forming surface. The semiconductor chip with the first protective film is suitable for use in manufacturing a semiconductor device by flip-chip bonding the bumps therein to a substrate. The resin film of this embodiment is suitable for use in the form of the composite sheet described above. Hereinafter, a method for manufacturing a semiconductor chip with a first protective film when using the composite sheet will be described.

[0184] A method for manufacturing a semiconductor chip with a first protective film according to one embodiment of the present invention is a method for manufacturing a semiconductor chip with a first protective film using a semiconductor wafer, wherein the semiconductor chip with the first protective film comprises a semiconductor chip and a first protective film provided on a side surface of the semiconductor chip and a surface having bumps, and the semiconductor wafer has bumps and grooves on one surface thereof that become dividing points of the semiconductor wafer, and the manufacturing method includes a bonding step of bonding the thermosetting resin film in the composite sheet according to the embodiment of the present invention to the one surface of the semiconductor wafer, thereby manufacturing a semiconductor wafer with a resin film provided on the one surface and having the resin film filled in the grooves, and the manufacturing method further includes a curing step (1) of thermally curing the resin film after the bonding step to form the first protective film, thereby manufacturing a semiconductor wafer with a first protective film that comprises the semiconductor wafer and the first protective film provided on the one surface of the semiconductor wafer and having the grooves filled a dividing step (1) of manufacturing a group of semiconductor chips with a first protective film, the group including a plurality of semiconductor chips and the first protective film provided on the surfaces of the plurality of semiconductor chips having the bumps and in the gaps between the semiconductor chips; and a cutting step (1) of manufacturing the semiconductor chips with the first protective film by cutting the first protective film along the gaps between the semiconductor chips in the group of semiconductor chips with the first protective film after the dividing step (1) (this manufacturing method may be referred to as "manufacturing method (1)" in this specification), or a cutting step (2) of cutting the first protective film along the grooves in the semiconductor wafer with the first protective film after the curing step (1) to produce a cut semiconductor wafer with the first protective film, and a dividing step (2) of dividing the semiconductor wafer after the cutting step (2) to produce semiconductor chips with the first protective film (this manufacturing method may be referred to as "manufacturing method (2)" in this specification), or a manufacturing method of dividing the semiconductor wafer after the bonding step to produce a plurality of the semiconductor chips,The method includes a dividing step (3) of manufacturing a group of semiconductor chips with a resin film, the group including the resin film provided on the surfaces of the plurality of semiconductor chips having the bumps and in the gaps between the semiconductor chips; a curing step (3) of manufacturing a group of semiconductor chips with a first protective film, the group including the plurality of semiconductor chips and the first protective film provided on the surfaces of the plurality of semiconductor chips having the bumps and in the gaps between the semiconductor chips by thermally curing the resin film after the dividing step (3); and a cutting step (3) of obtaining the semiconductor chips with a first protective film by cutting the first protective film along the gaps between the semiconductor chips in the group of semiconductor chips with a first protective film after the curing step (3) (this manufacturing method may be referred to as "manufacturing method (3)" in this specification). These manufacturing methods will be described below.

[0185] <<Manufacturing method (1)>> 4A to 4E are cross-sectional views that schematically show a manufacturing method (1) as an example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet 1 shown in FIG. 3 is used. Here, since the resin film is used for forming the first protective film, the "composite sheet 1" is referred to as the "sheet 1 for forming the first protective film," and the "substrate 11" is referred to as the "first substrate 11."

[0186] <Attachment process> In the bonding step of manufacturing method (1), as shown in Figures 4A and 4B, the resin film 12 in the first protective film forming sheet 1 is bonded to one surface 9a of the semiconductor wafer 9 (hereinafter, sometimes referred to as the "bump forming surface"). The semiconductor wafer 9 has, on its bump-forming surface 9a, a plurality of bumps 91 and a plurality of grooves 90 which are to be the locations where the semiconductor wafer 9 is to be divided. In this process, by providing a first protective film forming sheet 1 on the semiconductor wafer 9, a resin film-attached semiconductor wafer 901 is produced, in which the bump forming surface 9a of the semiconductor wafer 9 is provided with a resin film 12 and the grooves 90 are filled with the resin film 12.

[0187] Here, a state is shown in which the top portion 9101 of the bump 91 protrudes from the resin film 12. The degree to which the top portion 9101 of the bump 91 protrudes from the resin film 12 can be adjusted by the composition and thickness of the resin film 12 or the conditions for applying the resin film 12.

[0188] In the attaching step of the manufacturing method (1), for example, first, the first protective film forming sheet 1 is placed so that its resin film 12 faces the bump formation surface 9a of the semiconductor wafer 9 as shown in FIG. 4A.

[0189] The thickness of the semiconductor wafer 9 to which the resin film 12 is attached is not particularly limited, but is preferably 100 to 1000 μm, more preferably 200 to 900 μm, and even more preferably 300 to 800 μm. When the thickness of the semiconductor wafer 9 is equal to or greater than the lower limit, warping due to shrinkage during curing of the resin film 12 can be easily suppressed. When the thickness of the semiconductor wafer 9 is equal to or less than the upper limit, the time required for dividing the semiconductor wafer 9, which will be described later, can be further reduced. In this specification, the "thickness of a semiconductor wafer" means the thickness of the semiconductor wafer in the region where the groove does not exist, when the semiconductor wafer has the groove.

[0190] The height of the bumps 91 is not particularly limited, but is preferably 120 to 300 μm, more preferably 150 to 270 μm, and particularly preferably 180 to 240 μm. When the height of the bumps 91 is equal to or greater than the lower limit, the function of the bumps 91 can be further improved. When the height of the bumps 91 is equal to or less than the upper limit, the effect of suppressing the resin film 12 from remaining on the bumps 91 can be further improved. In this specification, the "height of a bump" means the height of the bump at the highest point from the bump formation surface.

[0191] The width of the bump 91 is not particularly limited, but is preferably 170 to 350 μm, more preferably 200 to 320 μm, and particularly preferably 230 to 290 μm. When the width of the bump 91 is equal to or greater than the lower limit, the function of the bump 91 can be further improved. When the width of the bump 91 is equal to or less than the upper limit, the effect of suppressing the resin film 12 from remaining on the bump 91 can be further improved. In this specification, the "bump width" means the maximum length of a line segment obtained by connecting two different points on the bump surface when the bump is viewed in a plan view looking down on the bump from a direction perpendicular to the bump formation surface.

[0192] The distance between adjacent bumps 91 is not particularly limited, but is preferably 250 to 800 μm, more preferably 300 to 600 μm, and particularly preferably 350 to 500 μm. When the distance is equal to or greater than the lower limit, the function of the bumps 91 can be further improved. When the distance is equal to or less than the upper limit, the effect of suppressing the resin film 12 from remaining on the bumps 91 can be further improved. In this specification, the "distance between adjacent bumps" means the minimum distance between the surfaces of adjacent bumps.

[0193] The depth of the grooves 90 is not particularly limited as long as it is equal to or greater than the final target chip thickness and less than the thickness of the semiconductor wafer 9 before grinding, which will be described later, but is preferably 30 to 700 μm, more preferably 60 to 600 μm, and even more preferably 100 to 500 μm. When the depth of the grooves 90 is equal to or greater than the lower limit, the semiconductor wafer 9 can be more easily divided, which will be described later. When the depth of the grooves 90 is equal to or less than the upper limit, the semiconductor wafer 9 has a higher strength. In this specification, when the groove depth is not a constant value, the maximum value of the groove depth is adopted as the "groove depth."

[0194] The width of the groove 90 is not particularly limited, but is preferably 10 to 2000 μm, more preferably 30 to 1000 μm, even more preferably 40 to 500 μm, and particularly preferably 50 to 300 μm. When the width of the groove 90 is equal to or greater than the lower limit, the effect of preventing contact between adjacent semiconductor chips when dividing the semiconductor wafer 9, as described below, is enhanced. When the width of the groove 90 is equal to or less than the upper limit, the semiconductor wafer 9 has a higher strength. In this specification, when the groove width is not a constant value, the maximum value of the groove width is adopted as the "groove width."

[0195] Next, in the bonding step of manufacturing method (1), the resin film 12 is brought into contact with the bumps 91 on the semiconductor wafer 9, and the first protective film-forming sheet 1 is pressed against the semiconductor wafer 9. This causes the first surface 12a of the resin film 12 to be pressed against the surfaces 91a of the bumps 91 and the bump-forming surface 9a of the semiconductor wafer 9, successively. At this time, the resin film 12 is heated, causing the resin film 12 to soften and spread between the bumps 91 so as to cover the bumps 91, adhering to the bump-forming surface 9a and covering the surfaces 91a of the bumps 91, particularly the surfaces 91a in the vicinity of the bump-forming surface 9a, and embedding the bases of the bumps 91. Therefore, the resin film 12 is sufficiently adhered to the bump-forming surface 9a and the bases of the bumps 91, and further, the resin film 12 fills the grooves 90 on the semiconductor wafer 9. As a result of the above, a semiconductor wafer 901 with a resin film is obtained as shown in FIG. 4B.

[0196] As described above, the method for pressing the first protective film forming sheet 1 to the semiconductor wafer 9 can be any known method for pressing and attaching various sheets to an object, such as a method using a laminating roller.

[0197] The heating temperature of the first protective film-forming sheet 1 (resin film 12) when pressure-bonding it to the semiconductor wafer 9 may be a temperature at which the resin film 12 is not cured at all or does not harden excessively, and may be, for example, 80 to 100°C. The heating temperature is preferably 85 to 95°C, since this allows the resin film 12 to adhere sufficiently to the bump-forming surface 9a and the bases of the bumps 91, and enhances the effect of the resin film 12 being sufficiently filled into the grooves 90.

[0198] The pressure when the first protective film-forming sheet 1 (resin film 12) is pressure-bonded to the semiconductor wafer 9 is not particularly limited, and may be, for example, 0.1 to 1.5 MPa. The pressure is preferably 0.3 to 1 MPa, since this allows the resin film 12 to adhere sufficiently to the bump-forming surface 9a and the bases of the bumps 91, and enhances the effect of the resin film 12 being sufficiently filled into the grooves 90.

[0199] As described above, when the first protective film-forming sheet 1 is pressure-bonded to the semiconductor wafer 9, the resin film 12, the adhesive layer 14, and the buffer layer 13 in the first protective film-forming sheet 1 are subjected to pressure from the bumps 91, and initially, the first surface 12a of the resin film 12, the first surface 14a of the adhesive layer 14, and the first surface 13a of the buffer layer 13 are deformed into a concave shape. Then, in this state, the resin film 12 may be torn when pressure is applied from the bumps 91. When the X value is 19 or more and less than 10,000 (19≦X value<10,000), such a tear in the resin film 12 occurs. In this case, when the first surface 12a of the resin film 12 is finally pressure-bonded to the bump-forming surface 9a of the semiconductor wafer 9, the upper portion 910 including the apex 9101 of the bump 91 penetrates and protrudes through the resin film 12. In this final stage, the upper portion 910 of the bump 91 does not usually penetrate the buffer layer 13. This is because the buffer layer 13 has a buffering effect against the pressure applied by the bump 91.

[0200] Figure 4B shows a case where, at the stage when the attachment process is completed, no or almost no resin film 12 remains on the upper portion 910 including the top portion 9101 of the bump 91, and the remaining resin film 12 on the upper portion 910 of the bump 91 is suppressed. In this specification, unless otherwise specified, "almost no resin film remains on top of the bump" means that although a small amount of resin film remains on top of the bump, the remaining amount is such that it does not interfere with the electrical connection between the semiconductor chip and the substrate when the semiconductor chip equipped with this bump is flip-chip connected to the substrate.

[0201] When the X value is equal to or greater than 19 and less than 10,000, at the stage when the laminating step is completed, the resin film 12 is prevented from protruding from its original size, and therefore the resin film 12 is prevented from protruding from the bump-forming surface 9 a of the semiconductor wafer 9.

[0202] When the X value is equal to or greater than 19 and less than 10,000, repelling of the resin film 12 on the bump-forming surface 9a is further suppressed at the stage when the attaching step is completed. More specifically, with the resin film 12 provided on the bump-forming surface 9a, a phenomenon in which regions of the bumps 91 other than their upper portions 910 (for example, base portions near the bump-forming surface 9a) or regions of the bump-forming surface 9a near the bumps 91 are unintentionally not covered by the resin film 12 and are exposed is suppressed.

[0203] <Curing process (1)> In the curing step (1) after the bonding step of manufacturing method (1), the first support sheet 10 is removed from the semiconductor wafer 901 with a resin film, and then, as shown in Figure 4C, the resin film 12 is cured to form a first protective film 12', thereby producing a semiconductor wafer 902 with a first protective film, which includes a semiconductor wafer 9 and a first protective film 12' provided on the bump formation surface 9a of the semiconductor wafer 9 and filled in the grooves 90. In the curing step (1), the resin film 12 is cured by heating under the heating conditions as described above. The resin film 12 has a calorific value of 100 J / g or less for the first test piece produced using the resin film 12, and poor curing is suppressed.

[0204] Reference numeral 9b denotes the surface (back surface) of the semiconductor wafer 9 opposite to the bump-formed surface 9a.

[0205] In the semiconductor wafer 901 with a resin film, the grooves 90 on the semiconductor wafer 9 are sufficiently filled with the resin film 12, so that the curing step (1) results in a semiconductor wafer 902 with a first protective film in which the grooves 90 are sufficiently filled with the first protective film 12'.

[0206] <Dividing process (1)> In the dividing step (1) after the hardening step (1), the semiconductor wafer 9 is divided to produce a group 903 of semiconductor chips with a first protective film, which includes a plurality of semiconductor chips 9' and a surface 9a' having bumps on the plurality of semiconductor chips 9' (hereinafter sometimes referred to as the "bump forming surface") and a first protective film 12' provided in the gaps 90' between the semiconductor chips 9', as shown in Figure 4D.

[0207] The gap 90' between the semiconductor chips 9' is a region sandwiched between the side surfaces 9c' of the adjacent semiconductor chips 9'.

[0208] The semiconductor wafer 9 can be divided by a known method. In this embodiment, for example, the division can be performed by grinding the back surface 9b of the semiconductor wafer 9 using a grinding means such as a grinder. At this time, the semiconductor wafer 9 is ground in a direction from the back surface 9b of the semiconductor wafer 9 toward the bump-forming surface 9a until the grinding surface (back surface 9b) reaches the groove 90 (in other words, until the groove 90 appears, or in other words, until the gap 90' is formed). In this way, the thickness of the semiconductor wafer 9 is reduced, and the semiconductor wafer 9 is divided at the groove 90, and at the same time, the gap 90' is formed from the groove 90. The grinding of the back surface 9b of the semiconductor wafer 9 is performed until the thickness of the semiconductor chip 9' reaches a desired value. For example, grinding may be stopped when the grinding surface reaches the groove 90. Alternatively, the back surface 9b may be ground even after the grinding surface reaches the groove 90, along with the first protective film 12' present within the gap 90'.

[0209] In the dividing step (1), if necessary, a backgrinding tape may be applied to the surface of the first protective film-coated semiconductor wafer 902 on the bump formation surface 9a side, and the back surface 9b of the semiconductor wafer 9 may be ground.

[0210] In this specification, for convenience, the back surface of the semiconductor wafer 9 during grinding is also designated by the symbol 9b. Reference numeral 9b' denotes the surface (back surface) of the semiconductor chip 9' opposite to the bump-formed surface 9a'.

[0211] In the group of semiconductor chips 903 with a first protective film, all of the semiconductor chips 9' are held together by one first protective film 12'. When a backgrind tape is used as described above, all of the semiconductor chips 9' are held together by one first protective film 12' and the backgrind tape attached to the surface of the group of semiconductor chips 903 with a first protective film on the bump-forming surface 9a' side.

[0212] <Cutting process (1)> In the cutting process (1) after the dividing process (1), the first protective film 12' is cut along the gaps 90' between the semiconductor chips 9' in the group of semiconductor chips 903 with the first protective film, thereby producing semiconductor chips 900 with the first protective film, as shown in Figure 4E. Since the heat generation amount of the first test piece made using the resin film 12 is 100 J / g or less, poor hardening is suppressed, and processing debris that may be generated during cutting is less likely to adhere to the semiconductor chip 9'. The semiconductor chip 900 with a first protective film includes a semiconductor chip 9' and a first protective film 120' provided on a side surface 9c' and a bump-forming surface 9a' of the semiconductor chip 9'. The semiconductor chip 9' is protected by the first protective film 120' after cutting on its side surface 9c' and bump-forming surface 9a', respectively, and the protection effect obtained for the semiconductor chip 9' is significantly high.

[0213] When the semiconductor chip 9' has a rectangular planar shape when viewed from above the bump-forming surface 9a' side, one semiconductor chip 9' has four side surfaces 9c'. Therefore, in the semiconductor chip 900 with a first protective film, a first protective film 120' after cutting is integrally provided on all (i.e., four) side surfaces 9c' of the semiconductor chip 9' and one bump-forming surface 9a'. In this specification, the "first protective film after cutting" may be simply referred to as the "first protective film."

[0214] In the cutting step (1), the first protective film 12' is cut along the outer periphery of the semiconductor chip 9' (in other words, the side surface 9c'). At this time, it is preferable to cut the first protective film 12' filling the gap 90' between adjacent semiconductor chips 9' along the outer periphery of the semiconductor chip 9' (in other words, the side surface 9c') and divide it into two. In this way, it is possible to provide first protective films 120' with a more uniform shape after cutting on each side surface 9c' of the semiconductor chip 9'.

[0215] The first protective film 12' can be cut by a known method such as blade dicing or laser dicing.

[0216] Cutting of first protective film 12′ can be performed, for example, by attaching a known dicing sheet to the back surface 9b′ of semiconductor chip 9′ in group 903 of semiconductor chips with first protective film and removing the backgrind tape. If the backgrind tape has an energy ray-curable adhesive layer, the adhesive layer can be cured by irradiating it with energy rays, thereby making it easier to remove the backgrind tape from group 903 of semiconductor chips with first protective film.

[0217] In the semiconductor chip 900 with the first protective film, the first protective film 120' is sufficiently adhered to the bump-forming surface 9a', the bases of the bumps 91, and the side surfaces 9c' of the semiconductor chip 9', thereby preventing the first protective film 120' from peeling off from these. The first protective film 120' is provided with a sufficient thickness on the side surfaces 9c' of the semiconductor chip 9'.

[0218] Furthermore, when the X value is equal to or greater than 19 and less than 10,000, in the semiconductor chip 900 with the first protective film, the top 9101 of the bump 91 protrudes from the first protective film 120', and the first protective film 120' does not or hardly adheres to the upper part 910 including the top 9101 of the bump 91, thereby suppressing adhesion of the first protective film 120' to the upper part 910 of the bump 91. Furthermore, in the semiconductor chip 900 with the first protective film, the first protective film 120' is prevented from protruding from the bump-formed surface 9a' of the semiconductor chip 9'. Furthermore, repelling of the first protective film 120' is suppressed on the bump-forming surface 9a' of the semiconductor chip 9'. More specifically, with the first protective film 120' provided on the bump-forming surface 9a', a phenomenon in which regions of the bumps 91 other than their upper portions 910 (for example, base portions near the bump-forming surface 9a') or regions of the bump-forming surface 9a' near the bumps 91 are unintentionally exposed without being covered by the first protective film 120' is suppressed.

[0219] <<Manufacturing method (2)>> 5A to 5E are cross-sectional views that schematically show a manufacturing method (2) as another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet 1 shown in FIG. 3 is used.

[0220] <Attachment process, curing process (1)> In the manufacturing method (2), as shown in FIGS. 5A to 5C, the bonding step and the curing step (1) are performed in the same manner as in the manufacturing method (1), to produce the semiconductor wafer 902 with the first protective film.

[0221] <Cutting process (2)> In the cutting step (2) after the hardening step (1) of the manufacturing method (2), the first protective film 12' is cut along the groove 90 in the semiconductor wafer 902 with the first protective film, thereby producing a cut semiconductor wafer 904 with the first protective film, as shown in Figure 5D. In this step, it is preferable to cut the first protective film 12′ filled in the groove 90 along the side surface 90c of the groove 90. By doing so, it is possible to finally provide the first protective film having a more uniform shape after cutting on each side surface of the semiconductor chip.

[0222] In the cutting step (2), the first protective film 12' is cut from the surface 12b' opposite the semiconductor wafer 9 side of the first protective film 12' toward the surface 12a' facing the semiconductor wafer 9. At this time, the cuts in the first protective film 12' do not have to reach the tip of the first protective film 12' in the depth direction of the groove 90. However, in order to facilitate dividing the semiconductor wafer 9 as described below, it is preferable that the cuts be closer to the tip. It is more preferable that the cuts reach the tip, i.e., cut the first protective film 12'. FIG. 5D shows a case where the cuts in the first protective film 12' reach the tip and cut the first protective film 12' (representing the cut first protective film 120'). On the other hand, when the semiconductor wafer 9 is divided into semiconductor chips by grinding the back surface 9b of the semiconductor wafer 9 as described below, cracks or chips at the corners of the semiconductor chips and cracks or chips in the first protective film 12' present near the corners of the semiconductor chips are suppressed, so it is preferable that the reach position of the notch in the first protective film 12' coincides with the location where the back surface of the semiconductor chip is expected to ultimately be formed, or is near such a location.

[0223] The first protective film 12' can be cut by a known method such as blade dicing or laser dicing, as in the case of the cutting step (1).

[0224] <Dividing process (2)> In the dividing step (2) after the cutting step (2), the semiconductor wafer 9 is divided to produce semiconductor chips 900 with a first protective film, as shown in FIG. 5E. The semiconductor chips 900 with the first protective film obtained in the dividing step (2) are the same as the semiconductor chips 900 with the first protective film obtained in the cutting step (1).

[0225] The semiconductor wafer 9 can be divided by a known method, similar to the case of the dividing step (1). For example, when the back surface 9b of the semiconductor wafer 9 is ground using a grinding means such as a grinder, the back surface 9b is ground in a direction from the back surface 9b toward the bump-forming surface 9a until the ground surface (back surface 9b) reaches the groove 90. If, in the cutting step (2), the notch in the first protective film 12′ does not reach the tip of the first protective film 12′ in the depth direction of the groove 90, the back surface 9b is further ground together with the first protective film 12′ until the ground surface reaches the notch in the first protective film 12′.

[0226] As in the case of manufacturing method (1), in the semiconductor chip 900 with the first protective film obtained in the dividing step (2), peeling of the first protective film 120' from the bump-forming surface 9a', the bases of the bumps 91, and the side surfaces 9c' of the semiconductor chip 9' is suppressed. The side surfaces 9c' of the semiconductor chip 9' are provided with the first protective film 120' of sufficient thickness.

[0227] Furthermore, when the X value is equal to or greater than 19 and less than 10,000, the semiconductor chip 900 with the first protective film obtained in the dividing step (2) has the following effects: suppression of adhesion of the first protective film 120' to the upper part 910 of the bump 91; suppression of protrusion of the first protective film 120' from the bump forming surface 9a'; and suppression of repelling of the first protective film 120' from the bump forming surface 9a', as in the manufacturing method (1).

[0228] <<Manufacturing method (3)>> 6A to 6E are cross-sectional views that schematically show a manufacturing method (3) as yet another example of a method for manufacturing a semiconductor chip with a first protective film when the composite sheet 1 shown in FIG. 3 is used.

[0229] <Attachment process> In the manufacturing method (3), as shown in FIGS. 6A and 6B, the bonding step is carried out in the same manner as in the manufacturing method (1), and the semiconductor wafer 901 with the resin film is produced.

[0230] <Dividing process (3)> In the dividing step (3) after the bonding step of the manufacturing method (3), the semiconductor wafer 9 is divided to produce a group of semiconductor chips 905 with a resin film, which includes a plurality of semiconductor chips 9' and a resin film 12 provided on the bump forming surfaces 9a' of the plurality of semiconductor chips 9' and in the gaps 90' between the semiconductor chips 9', as shown in Figure 6C.

[0231] The semiconductor wafer 9 can be divided by a known method, similar to the case of the dividing step (1).

[0232] In the group of semiconductor chips with resin film 905, all the semiconductor chips 9' are held together by one resin film 12 and support sheet .

[0233] <Curing process (3)> In the curing process (3) after the dividing process (3), the first support sheet 10 is removed from the semiconductor chip group 905, and then the resin film 12 is cured to form a first protective film, thereby producing a semiconductor chip group 903 with a first protective film, which includes a plurality of semiconductor chips 9' and a first protective film 12' provided on the bump forming surfaces 9a' of the plurality of semiconductor chips 9' and in the gaps 90' between the semiconductor chips 9', as shown in Figure 6D. The group of semiconductor chips 903 with a first protective film obtained in the curing step (3) is the same as the group of semiconductor chips 903 with a first protective film obtained in the dividing step (1).

[0234] The resin film 12 can be cured by a known method, as in the curing step (1).

[0235] <Cutting process (3)> In the cutting process (3) after the hardening process (3), the first protective film 12' is cut along the gaps 90' between the semiconductor chips 9' in the group 903 of semiconductor chips with the first protective film, thereby producing semiconductor chips 900 with the first protective film. The semiconductor chips 900 with the first protective film obtained in the cutting step (3) are the same as the semiconductor chips 900 with the first protective film obtained in the cutting step (1).

[0236] The first protective film 12' can be cut by a known method, similar to the cutting step (1) described above.

[0237] As in the case of manufacturing method (1), in the semiconductor chip 900 with the first protective film obtained in the cutting step (3), peeling of the first protective film 120' from the bump-forming surface 9a', the bases of the bumps 91, and the side surfaces 9c' of the semiconductor chip 9' is suppressed. Further, the first protective film 120' having a sufficient thickness is provided on the side surfaces 9c' of the semiconductor chip 9'.

[0238] Furthermore, when the X value is equal to or greater than 19 and less than 10,000, the semiconductor chip 900 with the first protective film obtained in the cutting step (3) has the following effects: suppression of adhesion of the first protective film 120' to the upper part 910 of the bump 91; suppression of protrusion of the first protective film 120' from the bump forming surface 9a'; and suppression of repelling of the first protective film 120' from the bump forming surface 9a', as in the case of the manufacturing method (1).

[0239] Up to this point, we have explained the case where the composite sheet (sheet for forming the first protective film) 1 shown in Figure 3 is used, but even when using the composite sheet of the other embodiments described above, this composite sheet will achieve the same effects as when the composite sheet 1 is used.

[0240] The above-mentioned production methods (1) to (3) may include other steps different from the steps explained so far, within the scope of the present invention.

[0241] For example, when a second protective film is provided on the back surface of a semiconductor chip, manufacturing methods (1) to (3) may include, at any timing, a step of attaching a film for forming a second protective film in a sheet for forming a second protective film to the back surface of the semiconductor chip, a step of curing the film for forming a second protective film to form a second protective film if the film for forming a second protective film is curable, and a step of cutting the film for forming a second protective film or the second protective film along the outer periphery (side) of the semiconductor chip.

[0242] For example, if at any stage after the bonding process, the resin film 12, the first protective film 12', or the first protective film 120' after cutting remains on the upper portion 910 including the top portion 9101 of the bump 91, manufacturing methods (1) to (3) may include a removal process of removing the remaining resin film 12, the first protective film 12', or the first protective film 120' after cutting from the upper portion 910 of the bump 91 at any timing after the bonding process.

[0243] Residual parts of the resin film 12, the first protective film 12', or the first protective film 120' after cutting on the upper part 910 of the bump 91 can be removed by a known method such as plasma irradiation.

[0244] Up to this point, we have described the grinding of the backside of a semiconductor wafer or a semiconductor chip group by providing a support sheet or backgrinding tape on the bump-formed surface of a semiconductor wafer or a bump-formed surface of a semiconductor chip group via a resin film or a first protective film. However, in this embodiment, instead of the support sheet or backgrinding tape, a resin sheet other than these may be provided to grind the backside of a semiconductor wafer or a semiconductor chip group. Here, the resin sheet can be formed by embedding a resin film or a first protective film on the bump-formed surface of the semiconductor wafer or the bump-formed surface of the semiconductor chip group with a flowable resin, further embedding the surfaces of the bumps, and then curing the resin sheet. When providing such a resin sheet, a resin film covering the resin film or first protective film on the bump-formed surface and the surfaces of the bumps may be formed using another resin that is flexible enough to conform to the surfaces of the bumps before using the flowable resin, and then the resin sheet may be provided via this resin film. By providing the resin film in this manner, the resin sheet can be easily removed after grinding or the like of the rear surface of the semiconductor wafer or the rear surface of the semiconductor chip group.

[0245] ◇How to use semiconductor chips with first protective film The semiconductor chip with the first protective film can be used to manufacture a semiconductor device. For example, the semiconductor chip with the first protective film is flip-chip connected (mounted) at the tops of the bumps therein to the circuit formation surface of a circuit board. When a sheet for forming a second protective film is used, prior to flip-chip connection of the semiconductor chip with the first protective film, the semiconductor chip with the first protective film and the second protective film is separated from the dicing sheet in the sheet for forming the second protective film and picked up. The semiconductor chip with the first protective film and the second protective film can be picked up by a known method.

[0246] Thereafter, a semiconductor package is produced in accordance with a known method using the circuit board thus obtained on which the semiconductor chip has already been mounted, and the desired semiconductor device can be manufactured using this semiconductor package. [Example]

[0247] The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited to the examples shown below.

[0248] <Raw materials for producing the resin film-forming composition> The raw materials used in the production of the resin film-forming composition are shown below. [Polymer component (A)] (A)-1: Polyvinyl butyral having structural units represented by the following formulas (i)-1, (i)-2, and (i)-3 ("S-LEC BL-10" manufactured by Sekisui Chemical Co., Ltd., weight average molecular weight 25,000, glass transition temperature 59°C).

[0249] [ka] (wherein l1 is approximately 28, m1 is 1 to 3, and n1 is an integer of 68 to 74.)

[0250] [Epoxy resin (B1)] (B1)-1: Liquid modified bisphenol A epoxy resin (DIC Corporation, "Epicron EXA-4850-150", molecular weight 900, epoxy equivalent 450 g / eq) (B1)-2: Dicyclopentadiene-type epoxy resin (DIC Corporation "Epicron HP-7200HH", epoxy equivalent 254-264g / eq) (B1)-3: Bisphenol A epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 184-194 g / eq) [Thermal hardener (B2)] (B2)-1: o-Cresol novolac resin (DIC Corporation "Phenolite KA-1160", softening point 80°C, hydroxyl equivalent 117g / eq) (B2)-2: Biphenyl aralkyl phenolic resin ("MEHC-7851-H" manufactured by Meiwa Kasei Co., Ltd., solid dispersion type latent hardener, hydroxyl group equivalent 218 g / eq) [Curing accelerator (C)] (C)-1: 2-Phenyl-4,5-dihydroxymethylimidazole ("Curezol 2PHZ-PW" manufactured by Shikoku Chemicals Corporation) [Filling material (D)] (D)-1: Spherical silica modified with epoxy groups ("Admanano YA050C-MKK" manufactured by Admatechs Co., Ltd., average particle size 50 nm) (D)-2: Spherical silica modified with epoxy groups ("5SE-CH1" manufactured by Admatechs Co., Ltd., average particle size 500 nm) [Coupling agent (E)] (E)-1:3-Glycidoxypropyltrimethoxysilane (silane coupling agent, Shin-Etsu Silicones "KBM-403") [Additives (I)] (I)-1: Surfactant (acrylic polymer, BYK "BYK-361N") (I)-2: Silicone oil (aralkyl-modified silicone oil, "XF42-334" manufactured by Momentive Performance Materials Japan) (I)-3: Rheology control agent (polyhydroxycarboxylic acid ester, BYK "BYK-R606")

[0251] [Example 1] <<Production of the sheet for forming the first protective film>> <Production of Thermosetting Resin Film-Forming Composition> Polymer component (A)-1 (100 parts by mass), epoxy resin (B1)-1 (290 parts by mass), epoxy resin (B1)-2 (220 parts by mass), (B2)-1 (160 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (200 parts by mass), additive (I)-1 (25 parts by mass), and additive (I)-2 (3 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23 ° C. to obtain a composition (III) for forming a thermosetting resin film, in which the total concentration of all components other than the solvent was 45% by mass. Note that the amounts of all components other than the solvent shown here are the amounts of the target product excluding the solvent.

[0252] <Production of thermosetting resin film> A release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) made of polyethylene terephthalate, one side of which had been treated for release by silicone treatment, was used. Composition (III) obtained above was applied to the release-treated surface, and the resulting film was dried by heating at 120°C for 2 minutes to form a thermosetting resin film with a thickness of 45 μm.

[0253] <Production of the sheet for forming the first protective film> A laminate sheet (backgrind tape, "E-8510HR" manufactured by Lintec Corporation, also corresponding to the support sheet) corresponding to a laminate of a first substrate, a buffer layer, and a first adhesive layer was used, and the first adhesive layer in this laminate sheet was bonded to the thermosetting resin film on the release film obtained above. This resulted in a first protective film-forming sheet having the configuration shown in Figure 3, in which the first substrate, buffer layer, first adhesive layer, thermosetting resin film, and release film were laminated in this order in the thickness direction.

[0254] <<Evaluation of thermosetting resin films>> <Differential scanning calorimetry (DSC)> [Production of thermosetting resin film and first test piece] A 45 μm-thick thermosetting resin film was prepared using the same method as above, except for the coating amount of composition (III). The resulting thermosetting resin film was laminated to a thickness of 225 μm, and 5 mg of the thermosetting resin film was separated. This was used as the first test piece of the resin film before thermal curing. The 5 mg first test piece was sealed in an aluminum pan and heated from room temperature to 300°C at a heating rate of 10°C / min using a DSC device (TA Instruments, "Q-2000") under a nitrogen atmosphere, scanning the range from 50 to 300°C. The exothermic peaks in the range from 100 to 300°C were integrated from the scan chart to calculate the heat generated during the reaction.

[0255] <Evaluation of the ability of thermosetting resin film to fill grooves on wafer surfaces> [Preparation of silicon wafer with first protective film] Using a half-cut dicer (DISCO Corporation, "DFD6361"), multiple grooves, each 60 μm wide and 230 μm deep, were formed in a mesh pattern on the surface of a silicon wafer (12 inches in diameter, 750 μm thick) to obtain chips measuring 6 mm x 6 mm. Using a lamination device (roller laminator, "RAD-3510 F / 12" manufactured by Lintec Corporation), the sheet for forming the first protective film obtained above was laminated to the surface of the silicon wafer on which the grooves were formed, using the thermosetting resin film contained therein, under conditions of a table temperature of 90°C, an lamination speed of 2 mm / s, an lamination pressure of 0.5 MPa, and a roller lamination height of -200 μm. Next, the laminated sheet (support sheet) was peeled off from the first protective film-forming sheet to prepare a silicon wafer with a thermosetting resin film. Next, after being attached to the surface of the silicon wafer on which the grooves were formed, the thermosetting resin film was heat-treated using a pressure oven ("RAD-9100" manufactured by Lintec Corporation) under heating conditions of a temperature of 130°C, a time of 4 hours, and an internal furnace pressure of 0.5 MPa, thereby thermally curing the film and forming a first protective film. In this way, a silicon wafer with a first protective film was produced.

[0256] [Evaluation of thermosetting resin film's ability to fill grooves on wafer surfaces] The silicon wafers with the first protective film obtained above were observed using an optical microscope. The groove-filling suitability of the first protective film (i.e., the cured product of the thermosetting resin film) on the wafer surface was evaluated according to the following criteria. The results are shown in the "Groove-filling suitability" column in Table 1. (Evaluation criteria) A: No distortion was observed in the shape of the first protective film, and it had high suitability for filling grooves. B: The shape of the first protective film is slightly distorted in the area corresponding to the vicinity of the opening of the groove, but the groove filling suitability is good. C: Neither A nor B above applies, and the groove filling suitability is poor.

[0257] <Evaluation of processing waste> [Manufacturing silicon chips with first protective film] Again, a laminated sheet (backgrind tape, "E-8510HR" manufactured by Lintec Corporation) corresponding to a laminate of a first substrate, a buffer layer, and a first adhesive layer was used, and the first adhesive layer in this laminated sheet was bonded to the surface of the first protective film of the silicon wafer with the first protective film whose filling suitability had been evaluated. The back surface of the silicon wafer with the first protective film was ground until the ground surface reached the grooves, dividing the silicon wafer into silicon chips, and grinding was continued until the thickness of the silicon chips reached 200 μm. Next, using a laminating device (a roller-type laminator, manufactured by Lintec Corporation, model RAD-3510 F / 12), dicing tape (manufactured by Lintec Corporation, model D-686H) was attached to the backside (ground surface) of all of the silicon chips obtained above. Then, using a blade dicer (manufactured by Disco Corporation, model DFD6362), the first protective film was cut along the periphery of the obtained silicon chips by blade dicing. At this time, the blade movement speed was set to 10 mm / s, and the blade rotation speed was set to 50,000 rpm. The blade cut into the base material of the dicing tape to a depth of 20 μm from the surface facing the silicon chip. As a result of the above, a plurality of silicon chips with a first protective film were obtained, each comprising a silicon chip measuring 6 mm x 6 mm and a first protective film integrally formed on four side surfaces and one surface (the surface that had the groove in the silicon wafer) of the silicon chip, and fixed on dicing tape.

[0258] [evaluation] Next, after cutting with the blade, the intersections of the cutting lines were observed using an optical microscope. To ensure uniform observation, five intersections were selected for observation: one at the center of the silicon wafer and four locations near the periphery of the silicon wafer, each located approximately equidistant from the center and equidistant from each other. If any of the five locations showed signs of processing debris adhering to the chip, the entire group of silicon chips was deemed defective. The results of the "Number of defectives / Number of evaluations (=5)" are shown in the "Processing Debris Evaluation" column in Table 1.

[0259] <Measurement of Gc1 and Gc300 of thermosetting resin film and calculation of X value> [Production of thermosetting resin film and second test piece] Twenty 50 μm-thick thermosetting resin films were prepared in the same manner as above, except that the coating amount of composition (III) was changed. These thermosetting resin films were then laminated, and the resulting laminated film was cut into a disk having a diameter of 25 mm to prepare a second test piece of thermosetting resin film having a thickness of 1 mm.

[0260] [Measurement of Gc1 and Gc300 of thermosetting resin film and calculation of X value] The location where the test piece was to be placed in the viscoelasticity measuring device ("MCR301" manufactured by Anton Paar) was kept warm at 90°C in advance, and the second test piece of the thermosetting resin film obtained above was placed on this location, and the second test piece was fixed to the location by pressing a measuring jig against the top surface of the second test piece. Next, the strain generated in the second test piece was increased stepwise in the range of 0.01% to 1000% under the conditions of a temperature of 90°C and a measurement frequency of 1 Hz, and the storage modulus Gc of the second test piece was measured. Then, the X value was calculated from the measured values ​​of Gc1 and Gc300. The results are shown in Table 1.

[0261] <Measurement of protrusion amount of thermosetting resin film> [Production of thermosetting resin film and third test piece] A release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) made of polyethylene terephthalate, one side of which had been treated for release by silicone treatment, was used. Composition (III) obtained above was applied to the release-treated surface, and the resulting film was dried by heating at 120°C for 2 minutes to form a thermosetting resin film with a thickness of 30 μm. Next, this thermosetting resin film was processed together with the release film into a circular shape having a diameter of 170 mm to prepare a third test piece with a release film.

[0262] [Measurement of protrusion amount of thermosetting resin film] The entire exposed surface of the obtained third test piece (in other words, the surface opposite to the side provided with the release film) was bonded to the surface of a transparent strip-shaped backgrind tape ("E-8180" manufactured by Lintec Corporation) to obtain the laminate shown in Fig. 7. Fig. 7 is a plan view schematically showing the state of the obtained laminate when viewed from above the backgrind tape side. As shown here, the obtained laminate 101 is composed of a backgrinding tape 7, a third test piece 120 (thermosetting resin film 12), and a release film, laminated in this order in the thickness direction.

[0263] Next, the release film was removed from the resulting laminate, and the newly exposed surface of the third test piece (in other words, the surface of the third test piece opposite the side provided with the backgrind tape) was pressed against one surface of a 12-inch diameter silicon wafer, thereby attaching the third test piece to the surface of the silicon wafer. The third test piece was attached while being heated using a laminating device (a roller-type laminator, "RAD-3510 F / 12" manufactured by Lintec Corporation) under conditions of a table temperature of 90°C, an attachment speed of 2 mm / s, an attachment pressure of 0.5 MPa, and a roller attachment height of -200 μm. Next, for the third test piece with the backgrind tape attached to the silicon wafer, the maximum length of the line segment connecting two different points on the periphery was measured, and the measured value (maximum length of the line segment) was used to calculate the protrusion amount (mm) of the third test piece (in other words, the thermosetting resin film) by the method described with reference to Figure 2. The results are shown in Table 1.

[0264] [Example 2, Reference Example 1] <<Production of thermosetting resin film and sheet for forming first protective film, and evaluation of thermosetting resin film>> A thermosetting resin film and a sheet for forming a first protective film were produced and the thermosetting resin film was evaluated in the same manner as in Example 1, except that either or both of the types and amounts of the components blended during the production of the composition for forming a thermosetting resin film were changed so that the types and contents of the components contained in the composition for forming a thermosetting resin film were as shown in Table 1. The results are shown in Table 1. In Table 1, the notation "-" in the column for contained components means that the thermosetting resin film-forming composition does not contain that component.

[0265] [Table 1]

[0266] As is clear from the above results, no adhesion of processing debris to the chips was observed in Examples 1 and 2. In Examples 1 and 2, the calorific value obtained by differential scanning calorimetry (DSC) satisfied the requirement of 100 J / g or less. Similarly, in Examples 1 and 2, the content of the thermosetting component (B) relative to the total mass of the resin film was within the range of 10 to 75 mass%.

[0267] Furthermore, in Example 1, in which the content ratio of the thermosetting component (B) and the content ratio of the filler (D) were high and the X value was also high, the thermosetting resin film had particularly good suitability for filling grooves on the silicon wafer surface.

[0268] Furthermore, in Example 1 (Example 2 was not evaluated), the protrusion amount of the third test piece was 0 mm (no protrusion of the thermosetting resin film was observed), and the basic properties of this thermosetting resin film were good. In Examples 1 and 2, the X value was 27 to 65, and it was determined that the thermosetting resin films of Examples 1 and 2, when attached to an uneven surface (for example, a bump-formed surface of a semiconductor wafer), can penetrate convex portions (for example, bumps), can prevent the film from remaining on the upper parts of the convex portions, can prevent the film from protruding from the uneven surface, and can prevent the thermosetting resin film itself and its cured product from repelling on the uneven surface. [Industrial Applicability]

[0269] The present invention can be used in the manufacture of semiconductor chips and the like having bumps on their connection pads, which are used in flip-chip connection methods. [Explanation of symbols]

[0270] 1 composite sheet (sheet for forming first protective film), 10 support sheet (first support sheet), 10a one side of support sheet, 11 base material (first base material), 11a one side of base material, 12 resin film, 12a first side of resin film, 12' first protective film, 120' first protective film (first protective film after cutting), 13 buffer layer, 9 semiconductor wafer, 90 groove in semiconductor wafer, 9a semiconductor wafer Bump-formed surface of wafer, 9'...semiconductor chip, 9a'...bump-formed surface of semiconductor chip, 9c'...side surface of semiconductor chip, 91...bump, 900...semiconductor chip with first protective film, 901...semiconductor wafer with resin film, 902...semiconductor wafer with first protective film, 903...group of semiconductor chips with first protective film, 904...semiconductor wafer with first protective film that has been notched, 905...group of semiconductor chips with resin film

Claims

1. A thermosetting resin film, the thermosetting resin film contains a polymer component (A), an epoxy resin (B1), a thermosetting agent (B2), a filler (D), and an additive (I), the polymer component (A) is one or more selected from the group consisting of polyvinyl acetal, a urethane resin, and a silicone resin; the ratio of the total content of the epoxy resin (B1) and the thermosetting agent (B2) in the thermosetting resin film to the total mass of the thermosetting resin film is 10 to 75 mass%, The resin film has a calorific value of 100 J / g or less in the range of 100 to 300°C, as determined by analyzing the resin film before heat curing as a first test piece by differential scanning calorimetry (DSC) under a constant temperature rise condition of a temperature rise rate of 10°C / min.

2. A resin film having a diameter of 25 mm and a thickness of 1 mm was used as a second test piece, and strain was generated in the second test piece under conditions of a temperature of 90°C and a frequency of 1 Hz to measure the storage elastic modulus of the second test piece. When the storage elastic modulus of the second test piece when the strain of the second test piece is 1% is defined as Gc1, and the storage elastic modulus of the second test piece when the strain of the second test piece is 300% is defined as Gc300, the following formula was obtained: X=Gc1 / Gc300 The resin film according to claim 1, wherein the X value calculated by the above formula is 19 or more and less than 10,000.

3. The resin film according to claim 1 or 2, which is to be attached to an uneven surface.

4. The resin film according to any one of claims 1 to 3, wherein the resin film is for protecting the uneven surface and side surfaces of a semiconductor chip.

5. A support sheet and a resin film provided on one surface of the support sheet, The composite sheet, wherein the resin film is the resin film according to any one of claims 1 to 4.

6. 6. The composite sheet according to claim 5, wherein the support sheet comprises a substrate and an adhesive layer provided on one surface of the substrate, and the adhesive layer is disposed between the substrate and the resin film.

7. 7. The composite sheet according to claim 5 or 6, wherein the support sheet comprises a substrate and a buffer layer provided on one surface of the substrate, and the buffer layer is disposed between the substrate and the resin film.

8. A method for manufacturing a semiconductor chip with a first protective film using a semiconductor wafer, comprising: The semiconductor chip with a first protective film includes a semiconductor chip and a first protective film provided on a side surface of the semiconductor chip and a surface having bumps, the semiconductor wafer has, on one surface thereof, bumps and grooves that become dividing portions of the semiconductor wafer; The manufacturing method includes a bonding step of bonding the resin film in the composite sheet according to any one of claims 5 to 7 to the one surface of the semiconductor wafer, thereby producing a semiconductor wafer with a resin film, the semiconductor wafer having the resin film on the one surface and the grooves filled with the resin film; The manufacturing method further comprises: a curing step (1) of thermally curing the resin film after the bonding step to form the first protective film, thereby producing a semiconductor wafer with a first protective film, the semiconductor wafer including the semiconductor wafer and the first protective film provided on the one surface of the semiconductor wafer and filling the grooves; a dividing step (1) of dividing the semiconductor wafer after the curing step (1) to produce a group of semiconductor chips with a first protective film, the group including a plurality of semiconductor chips and the first protective film provided on surfaces of the plurality of semiconductor chips having the bumps and in gaps between the semiconductor chips; and a cutting step (1) of cutting the first protective film along the gaps between the semiconductor chips in the group of semiconductor chips with a first protective film, after the dividing step (1), to produce the semiconductor chips with a first protective film; a cutting step (2) of cutting the first protective film along the grooves in the semiconductor wafer with the first protective film after the bonding step and the curing step (1) to produce a cut-in semiconductor wafer with the first protective film, and a dividing step (2) of dividing the semiconductor wafer after the cutting step (2) to produce semiconductor chips with the first protective film, or a dividing step (3) of dividing the semiconductor wafer after the bonding step to produce a group of semiconductor chips with a resin film, the group including a plurality of the semiconductor chips and the resin film provided on the surfaces of the plurality of semiconductor chips having the bumps and in the gaps between the semiconductor chips; a curing step (3) of thermally curing the resin film after the dividing step (3) to form the first protective film, thereby producing a group of semiconductor chips with a first protective film, the group including a plurality of the semiconductor chips and the first protective film provided on the surfaces of the plurality of semiconductor chips having the bumps and in the gaps between the semiconductor chips; and a cutting step (3) of cutting the first protective film along the gaps between the semiconductor chips in the group of semiconductor chips with a first protective film after the curing step (3), to obtain the semiconductor chips with a first protective film.

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