First protective film forming sheet, method of manufacturing semiconductor device, and use of sheet

Abstract

To provide a protective film forming sheet equipped with a protective film forming film for forming a protective film on a bump formation surface of a semiconductor wafer, the sheet being configured to allow members other than the protective film forming film to be easily removed after pasting the protective film forming sheet on the bump formation surface without curing any of layers in the members.SOLUTION: A first protective film forming sheet 1 for forming at least a first protective film on a bump formation surface of a semiconductor wafer is configured by laminating a first substrate 11, a buffer layer 12, an intermediate peeling layer 13, and a first protective film forming film 14 in this order. In a peeling test to peel the intermediate peeling layer 13 at 180 degrees from the first protective film forming film 14 using a test piece having a width of 25 mm of the first protective film forming sheet 1, peel force between the intermediate peeling layer 13 and the first protective film forming film 14 is 1000 mN / 25 mm or lower.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sheet for forming a first protective film, a method for manufacturing a semiconductor device, and use of the sheet. [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 has been used 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, and the flip-chip mounting method has been adopted in which these bumps are brought face-to-face and into contact with corresponding terminal portions on a chip-mounting substrate using the so-called face-down method, and melt / diffusion bonding is performed.

[0003] The semiconductor chip used in this mounting method is obtained, for example, by grinding or dicing the surface opposite to the circuit surface (in other words, the bump-formed surface) of a semiconductor wafer having bumps formed on the circuit surface into individual pieces. In the process of obtaining such a semiconductor chip, for example, a curable protective film-forming film is attached to the bump-formed surface of the semiconductor wafer for the purpose of protecting the bumps and the bumps, and the film is cured to form a protective film on the bump-formed surface. In this specification, such a protective film-forming film and protective film may be referred to as a "first protective film-forming film" and a "first protective film", respectively. At this time, it is desirable that the bumps on the bump-formed surface penetrate the protective film-forming film (first protective film-forming film), the tops of the bumps protrude from the protective film-forming film, and further, no protective film-forming film remains on the upper part including the tops of the bumps. This is because the semiconductor chip is used as is for flip-chip mounting.

[0004] On the other hand, when the protective film-forming film is attached to the bump-forming surface, a sheet for forming a protective film may be used in which the protective film-forming film, the adhesive layer, and the base material are laminated in this order. In this specification, such a sheet for forming a protective film may be referred to as a "first sheet for forming a protective film." In this case, the adhesive layer and the base material are peeled off from the protective film-forming film after it is attached to the bump-forming surface, and the protective film-forming film is cured. If the adhesive layer and the base material are not peeled off from the protective film-forming film, the subsequent steps cannot be performed normally.

[0005] Such a sheet for forming a protective film is disclosed in which a substrate, a pressure-sensitive adhesive layer, and a thermosetting resin layer are laminated in this order, the melt viscosity of the thermosetting resin layer is in a specific range, and the shear modulus of the pressure-sensitive adhesive layer is in a specific range at a specific temperature range of the pressure-sensitive adhesive layer (see Patent Document 1). In this sheet for forming a protective film (sheet for forming a first protective film), the cured product of the thermosetting resin layer becomes the protective film (first protective film). Patent Document 1 also describes that when the thermosetting resin layer contains an epoxy resin and a phenolic resin, and the pressure-sensitive adhesive layer contains an acrylic polymer, the peelability between the thermosetting resin layer and the pressure-sensitive adhesive layer is improved. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2015-92594 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in Patent Document 1, the only sheet specifically disclosed as a sheet for forming a protective film in which the peelability between the thermosetting resin layer and the adhesive layer is improved is a sheet for forming a protective film having an ultraviolet-curable adhesive layer. Moreover, the peelability between the thermosetting resin layer and the adhesive layer is improved only when the adhesive layer is cured with ultraviolet light. Therefore, in the sheet for forming a protective film disclosed in Patent Document 1, if the adhesive layer is not cured, it is unclear whether the peelability between the thermosetting resin layer and the adhesive layer is improved, and in order to improve the peelability, the adhesive layer needs to be cured, which increases the number of manufacturing steps for semiconductor chips.

[0008] The present invention aims to provide a protective film forming sheet having a protective film forming film for forming a protective film on a surface of a semiconductor wafer having bumps, which sheet can be attached to a surface having bumps, and when other components are peeled off from the protective film forming film after the protective film forming sheet is attached, the other components can be easily peeled off without hardening any of the layers in the other components. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention employs the following configuration. [1] A first protective film-forming sheet for forming a first protective film on at least a surface having bumps of a semiconductor wafer, the first protective film-forming sheet being configured by laminating a first base material, a buffer layer, an intermediate release layer, and a first protective film-forming film in this order in the thickness direction, and when a peel test is performed using a test piece of the first protective film-forming sheet having a width of 25 mm, in which the intermediate release layer is peeled off from the first protective film-forming film, and the angle formed by the surface of the first protective film-forming film on which the intermediate release layer was attached and the surface of the intermediate release layer on which the first protective film was attached is set to 180°, the intermediate release layer is peeled off from the first protective film-forming film in its length direction at a peel speed of 100 mm / min, the peel force between the intermediate release layer and the first protective film-forming film is 1000 mN / 25 mm or less.

[0010] [2] The first protective film-forming sheet described in [1], wherein the intermediate release layer contains an ethylene-vinyl acetate copolymer, and in the ethylene-vinyl acetate copolymer, the ratio of the amount of structural units derived from vinyl acetate to the total amount of structural units is 40 mass% or less. [3] The sheet for forming a first protective film according to [2], wherein the ethylene-vinyl acetate copolymer has a weight average molecular weight of 200,000 or less.

[0011] [4] A method for manufacturing a semiconductor device using the first protective film-forming sheet according to any one of [1] to [3], the manufacturing method including a bonding step of bonding the first protective film-forming film in the first protective film-forming sheet to a surface of a semiconductor wafer having bumps and causing tops of the bumps to protrude from the first protective film-forming film, thereby providing the first protective film-forming sheet on the semiconductor wafer; and after the bonding step, peeling the intermediate release layer in the first protective film-forming sheet from the first protective film-forming film to remove layers of the first protective film-forming sheet other than the first protective film-forming film from the first protective film-forming film, and further, when the first protective film-forming film is curable, curing the first protective film-forming film to form a first protective film, and When the film-forming film is non-curable, the method for manufacturing a semiconductor device includes a first protective film forming step of forming the first protective film on the surface having the bumps by treating the first protective film-forming film after removing layers other than the first protective film-forming film as a first protective film, a dividing step of producing semiconductor chips by dividing the semiconductor wafer after the first protective film forming step, a cutting step of cutting the first protective film after the first protective film forming step, and a mounting step of flip-chip connecting the semiconductor chip with the first protective film, in which the tops of the bumps protrude from the first protective film, to a substrate at the tops of the bumps. [5] The method for manufacturing a semiconductor device according to [4], wherein in the attaching step, the first protective film-forming film is attached to the surface of the semiconductor wafer having the bumps at an attachment speed of 4 mm / s or more.

[0012] [6] Use of a sheet for forming a first protective film on at least a surface having bumps of a semiconductor wafer, the sheet being a first protective film-forming sheet constructed by laminating a first base material, a buffer layer, an intermediate release layer, and a first protective film-forming film in this order in the thickness direction, wherein when a peel test is performed using a test piece of the first protective film-forming sheet having a width of 25 mm, in which the intermediate release layer is peeled from the first protective film-forming film, and the angle formed by the surface of the first protective film-forming film on which the intermediate release layer was affixed and the surface of the intermediate release layer on which the first protective film-forming film was affixed is set to 180°, the intermediate release layer is peeled from the first protective film-forming film in its length direction at a peel speed of 100 mm / min, the peel force between the intermediate release layer and the first protective film-forming film is 1000 mN / 25 mm or less. Effect of the Invention

[0013] According to the present invention, there is provided a protective film forming sheet comprising a protective film forming film for forming a protective film on a surface of a semiconductor wafer having bumps, wherein after the protective film forming sheet is affixed to the surface having the bumps, when other components are peeled off from the protective film forming film, the other components can be easily peeled off without hardening any of the layers in the other components. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view that illustrates an example of a first protective film-forming sheet according to an embodiment of the present invention. [Figure 2A] FIG. 2 is a cross-sectional view for illustrating a schematic example of a method for manufacturing a semiconductor device when the first protective film-forming sheet shown in FIG. 1 is used. [Figure 2B] FIG. 2 is a cross-sectional view for illustrating a schematic example of a method for manufacturing a semiconductor device when the first protective film-forming sheet shown in FIG. 1 is used. [Figure 2C] FIG. 2 is a cross-sectional view for illustrating a schematic example of a method for manufacturing a semiconductor device when the first protective film-forming sheet shown in FIG. 1 is used. [Figure 2D] FIG. 2 is a cross-sectional view for illustrating a schematic example of a method for manufacturing a semiconductor device when the first protective film-forming sheet shown in FIG. 1 is used. [Figure 2E] FIG. 2 is a cross-sectional view for illustrating a schematic example of a method for manufacturing a semiconductor device when the first protective film-forming sheet shown in FIG. 1 is used. [Figure 3A] 1. FIG. 4 is a cross-sectional view for illustrating a schematic example of another example of a method for manufacturing a semiconductor device when the first protective film-forming sheet shown in FIG. 1 is used. [Figure 3B] 1. FIG. 4 is a cross-sectional view for illustrating a schematic example of another example of a method for manufacturing a semiconductor device when the first protective film-forming sheet shown in FIG. 1 is used. [Figure 3C] 1. FIG. 4 is a cross-sectional view for illustrating a schematic example of another example of a method for manufacturing a semiconductor device when the first protective film-forming sheet shown in FIG. 1 is used. [Figure 3D] 1. FIG. 4 is a cross-sectional view for illustrating a schematic example of another example of a method for manufacturing a semiconductor device when the first protective film-forming sheet shown in FIG. 1 is used. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] ◇First protective film forming sheet A first protective film forming sheet according to one embodiment of the present invention is a first protective film forming sheet for forming a first protective film on at least a surface having bumps of a semiconductor wafer, and the first protective film forming sheet is composed of a first substrate, a buffer layer, an intermediate release layer, and a first protective film forming film laminated in this order in the thickness direction. When a peel test is performed using a test piece of the first protective film forming sheet having a width of 25 mm, in which the intermediate release layer is peeled off from the first protective film forming film and the angle formed by the surface of the first protective film forming film on which the intermediate release layer was attached and the surface of the intermediate release layer on which the first protective film was attached is set to 180°, the intermediate release layer is peeled off from the first protective film forming film in its length direction at a peel speed of 100 mm / min, the peel force between the intermediate release layer and the first protective film forming film is 1000 mN / 25 mm or less. In the sheet for forming a first protective film of this embodiment, the peel force between the intermediate release layer in the test piece and the first protective film-forming film is 1000 mN / 25 mm or less, so that after the sheet for forming a first protective film of this embodiment is attached to a surface of a semiconductor wafer having bumps, when the other components other than the first protective film-forming film, i.e., the first substrate, the buffer layer and the intermediate release layer, are peeled off from the first protective film-forming film, these other components (the first substrate, the buffer layer and the intermediate release layer) can be easily peeled off without hardening any of these layers, particularly the intermediate release layer adjacent to the first protective film-forming film. In the rest of this specification, the fact that after the first protective film-forming sheet is attached to the bump-bearing surface of a semiconductor wafer, the first substrate, buffer layer and intermediate release layer can be easily peeled off from the protective film-forming film without hardening the intermediate release layer, etc., will be described as the laminate of the first substrate, buffer layer and intermediate release layer having good peelability, etc.

[0016] In this specification, the surface of a semiconductor wafer or a semiconductor chip that has bumps may be referred to as a "bump-formed surface," and the surface of the semiconductor wafer or the semiconductor chip opposite to the bump-formed surface may be referred to as a "rear surface."

[0017] In this specification, the protective film provided on the surface of the semiconductor wafer or semiconductor chip opposite to the surface on which bumps are formed (that is, the back surface) is referred to as a "second protective film". In order to provide a second protective film on the surface (rear surface) opposite to the bump-forming surface of a semiconductor wafer or semiconductor chip, a sheet for forming a second protective film is used, which is configured to include a second protective film-forming film for forming the second protective film. An example of the sheet for forming a second protective film is one 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 first substrate, this substrate is referred to as a "second substrate".

[0018] The sheet for forming a first protective film of this embodiment can form a first protective film not only on the bump formation surface of a semiconductor chip, but also on the side surface as described below. That is, the sheet for forming a first protective film of this embodiment can be used as a sheet for forming a first protective film at least on the bump formation surface of a semiconductor wafer.

[0019] FIG. 1 is a cross-sectional view that illustrates an example of the first protective film-forming sheet of the present embodiment. In addition, the figures used in the following explanation may show key parts enlarged for 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 the actual ones.

[0020] The first protective film-forming sheet 1 shown here is configured to include a first substrate 11, a buffer layer 12 provided on one surface 11a of the first substrate 11, an intermediate release layer 13 provided on a surface 12a of the buffer layer 12 opposite the first substrate 11 side, and a first protective film-forming film 14 provided on a surface (sometimes referred to as the "first surface" in this specification) 13a of the intermediate release layer 13 opposite the buffer layer 12 side. That is, the first protective film-forming sheet 1 is configured by laminating the first substrate 11, the buffer layer 12, the intermediate release layer 13, and the first protective film-forming film 14 in this order in the thickness direction. The first protective film-forming sheet 1 further includes a release film 15 provided on the side 14a opposite the intermediate release layer 13 side of the first protective film-forming film 14 (sometimes referred to as the "first side" in this specification).

[0021] In the test piece prepared from the first protective film-forming sheet 1, the intermediate release layer 13 exhibits the above-mentioned peel force (1000 mN / 25 mm or less) against the first protective film-forming film .

[0022] The release film 15 is not particularly limited and may be a known one. In the first protective film-forming sheet 1, the release film 15 is an optional configuration, and the first protective film-forming sheet 1 does not necessarily have to include the release film 15.

[0023] The first protective film forming sheet of this embodiment is not limited to that shown in FIG. 1, and some of the configuration may be changed, deleted, or added to that shown in FIG. 1 as long as the effects of the present invention are not impaired. For example, the first protective film-forming sheet of this embodiment may further include other layers that do not fall under any of the first substrate, the buffer layer, the intermediate release layer, the first protective film-forming film, and the release film. However, in a first protective film-forming sheet that does not include a release film, it is preferable that the first protective film-forming film is one of the outermost layers, that is, the layer that is disposed on the outermost side in the stacking direction of each layer. In addition, in the first protective film-forming sheet of this embodiment, it is preferable that the first substrate and the buffer layer are provided in direct contact with each other, the buffer layer and the intermediate release layer are provided in direct contact with each other, and the intermediate release layer and the first protective film-forming film are provided in direct contact with each other. Next, each layer constituting the first protective film-forming sheet of this embodiment will be described.

[0024] ◎First protective film forming film The first protective film-forming film may be curable or non-curable. For example, the first protective film-forming film may function as the first protective film by being cured, or may function as the first protective film in an uncured state. The curable first protective film-forming film may be either thermosetting or energy ray curable, or may have both thermosetting and energy ray curable properties.

[0025] The first protective film-forming film is preferably curable in that it is possible to form a first protective film having higher protective ability.

[0026] In this specification, the term "energy rays" refers to electromagnetic waves or charged particle beams that have an energy quantum. Examples of energy rays include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated by using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, or an LED lamp as an ultraviolet ray source. Electron beams can be irradiated by generating them using an electron beam accelerator or the like. In this specification, "energy ray curable" means a property that is cured by irradiation with energy rays, and "non-energy ray curable" means a property that is not cured even when irradiated with energy rays. In this specification, the term "non-curable" refers to a property that does not cure by any means, such as heating or irradiation with energy rays.

[0027] The first protective film-forming film contains a resin component, and may or may not contain components other than the resin component.

[0028] The first protective film-forming film is soft and has high conformability to uneven surfaces such as the bump-formed surface of a semiconductor wafer, etc. As a result, the first protective film-forming film and the first protective film exhibit high adhesion to uneven surfaces such as the bump-formed surface of a semiconductor wafer, and the first protective film exhibits high adhesion to uneven surfaces such as the bump-formed surface of a semiconductor chip.

[0029] When the first protective film-forming film in the first protective film-forming sheet of this embodiment is attached to the bump-forming surface of the semiconductor wafer while being heated, the bumps on the bump-forming surface penetrate the first protective film-forming film, and the tops of the bumps protrude from the first protective film-forming film. The softened first protective film-forming film then spreads between the bumps so as to cover them, adheres to the bump-forming surface, covers the surfaces of the bumps, particularly the surfaces of the areas in the vicinity of the bump-forming surface, and embeds the bases of the bumps. In this state, the first protective film-forming film is suppressed from remaining on the upper parts of the bumps. When the first protective film-forming film is curable, the first protective film-forming film in this state (the state in which the bases of the bumps are embedded) subsequently hardens to finally form the first protective film, and when the first protective film-forming film is non-curable, the first protective film-forming film after this state (the state in which the bases of the bumps are embedded) functions as the first protective film. Naturally, the first protective film is also prevented from adhering to the upper part of the bump. In particular, as described later, when the first protective film-forming sheet of this embodiment is used in which the intermediate release layer contains ethylene-vinyl acetate copolymer (EVA), even if the first protective film-forming film in the first protective film-forming sheet is attached to the bump-forming surface of the semiconductor wafer at high speed, the top of the bump protrudes from the first protective film-forming film, and the first protective film-forming film remains and the first protective film is prevented from adhering to the upper part of the bump. The reason why the first protective film-forming sheet of this embodiment has such excellent characteristics is that the first protective film-forming sheet is configured by laminating the first base material, the buffer layer, the intermediate release layer, and the first protective film-forming film in this order, and the intermediate release layer contains ethylene-vinyl acetate copolymer.

[0030] In recent years, in order to efficiently form a protective film on the bump formation surface, it has been considered to attach the protective film-forming film in the protective film-forming sheet to the bump formation surface at a higher speed than before. However, when attaching the protective film-forming film to the bump formation surface, not only is the attachment itself difficult, but it is also difficult to make the tops of the bumps protrude from the protective film-forming film, and even if they do protrude, the protective film-forming film is likely to remain on the upper part including the tops of the bumps. Therefore, a first protective film-forming sheet that can be attached normally even when the first protective film-forming film is attached to the bump formation surface of a semiconductor wafer at a high speed is extremely useful.

[0031] The presence or absence of the first protective film-forming film remaining on the top of the bumps on the bump-forming surface and the presence or absence of the first protective film attached can be confirmed, for example, by obtaining image data of the top of the bumps using a scanning electron microscope (SEM).

[0032] After the first protective film-forming sheet of this embodiment is attached to the bump-forming surface of the semiconductor wafer, the laminate of the first base material, the buffer layer, and the intermediate release layer has good peelability when peeled from the first protective film-forming film on the bump-forming surface. This is because, as described above, the peel force between the intermediate release layer and the first protective film-forming film in the test piece is 1000 mN / 25 mm or less. Typically, the peeling of the laminate from the first protective film-forming film is an interfacial peeling between the intermediate release layer and the first protective film-forming film. Furthermore, the remaining intermediate release layer is suppressed on the surface opposite to the first surface of the first protective film-forming film (sometimes referred to as the "second surface" in this specification).

[0033] As described below, such good releasability can be more easily achieved when the intermediate release layer contains an ethylene-vinyl acetate copolymer (EVA).

[0034] Regardless of whether the first protective film-forming film is curable or non-curable, and when it is curable, regardless of whether it is heat curable or energy ray curable, the first protective film-forming film may be composed of one layer (single layer) or may be composed of two or more layers. When the first protective film-forming 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.

[0035] In this specification, not only in the case of the first protective film-forming film, "multiple layers may be the same or different from each other" means "all layers may be the same, all layers may be different, or only some layers may be the same", and further, "multiple layers are different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other".

[0036] Regardless of whether the first protective film-forming film is curable or non-curable, and in the case of curable, regardless of whether it is thermosetting or energy ray curable, the thickness of the first protective film-forming film is preferably 1 to 200 μm, more preferably 10 to 150 μm, and particularly preferably 20 to 130 μm. When the thickness of the first protective film-forming film is equal to or greater than the lower limit, the effect of the first protective film-forming film is enhanced. For example, when a protective film is formed using the first protective film-forming film, a protective film with higher protective ability can be formed. When the thickness of the first protective film-forming film is equal to or less than the upper limit, the first protective film is prevented from becoming excessively thick.

[0037] As described later, when the first protective film is formed not only on the bump-formed surface of the semiconductor chip but also on the side surface, it is necessary to use a semiconductor wafer having grooves on the bump-formed surface. In this way, when the first protective film is formed on the side surface of the semiconductor chip as well, in addition to the same reasons as above, the thickness of the first protective film-forming film is preferably 2 to 200 μm, more preferably 30 to 150 μm, and particularly preferably 30 to 130 μm, in terms of being able to sufficiently fill the grooves with the first protective film-forming film. On the other hand, when the first protective film is formed on the bump-forming surface of the semiconductor chip but not on the side surface, a semiconductor wafer having no grooves on the bump-forming surface may be used. In this case, for the same reasons as above (the effect of the first protective film-forming film is enhanced; the first protective film is prevented from becoming excessively thick), the thickness of the first protective film-forming film is preferably 1 to 100 μm, more preferably 20 to 75 μm, and particularly preferably 35 to 55 μm.

[0038] In this specification, "thickness of the first protective film-forming film" means the entire thickness of the first protective film-forming film; for example, the thickness of a first protective film-forming film consisting of multiple layers means the total thickness of all layers that make up the first protective film-forming film.

[0039] In this specification, "thickness" is not limited to the case of the first protective film-forming film, and unless otherwise specified, means the average thickness measured at five randomly selected points on the object, and can be obtained using a constant pressure thickness gauge in accordance with JIS K7130.

[0040] <<Composition for forming the first protective film>> The first protective film-forming film can be formed using a first protective film-forming composition containing its constituent materials. For example, the first protective film-forming film can be formed by applying the first protective 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 first protective film-forming composition is usually the same as the ratio of the contents of the components in the first protective film-forming film. In this specification, "room temperature" means a temperature that is not particularly cooled or heated, that is, a normal temperature, and examples thereof include a temperature of 15 to 25°C.

[0041] The thermosetting first protective film-forming film can be formed using a thermosetting first protective film-forming composition, the energy ray-curable first protective film-forming film can be formed using an energy ray-curable first protective film-forming composition, and the non-curable first protective film-forming film can be formed using a non-curable first protective film-forming composition. In this specification, when the first protective film-forming film has both thermosetting and energy ray curing properties, if the contribution of the thermosetting of the first protective film-forming film is greater than the contribution of the energy ray curing in forming the first protective film, the first protective film-forming film is treated as being thermosetting. Conversely, when the contribution of the energy ray curing of the first protective film is greater than the contribution of the thermosetting in forming the first protective film, the first protective film-forming film is treated as being energy ray curing.

[0042] In the first protective film-forming film, the ratio of the total content of one or more components contained in the first protective film-forming film, which will be described later, to the total mass of the first protective film-forming film does not exceed 100 mass %. Similarly, in the composition for forming the first protective film, the ratio of the total content of one or more of the components described below in the composition for forming the first protective film to the total mass of the composition for forming the first protective film does not exceed 100 mass%.

[0043] The composition for forming the first protective film may be applied by a known method, such as a method 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.

[0044] Regardless of whether the first protective film-forming film is curable or non-curable, and regardless of whether the first protective film-forming film is heat-curable or energy ray-curable when the first protective film-forming film is curable, the drying conditions of the first protective film-forming composition are not particularly limited. However, when the first protective film-forming composition contains a solvent described later, it is preferable to heat-dry it. And, the first protective film-forming composition containing the solvent is preferably heat-dried, for example, at 70 to 130°C for 10 seconds to 5 minutes. However, it is preferable to heat-dry the thermosetting first protective film-forming composition so that the composition itself and the thermosetting first protective film-forming film formed from the composition are not thermally cured.

[0045] The thermosetting first protective film-forming film, the energy ray-curable first protective film-forming film, and the non-curable first protective film-forming film will be described in further detail below.

[0046] Thermosetting first protective film The thermosetting first protective film-forming film may, for example, contain a polymer component (A), a thermosetting component (B), a curing accelerator (C), a filler (D), and an additive (I).

[0047] The curing conditions for curing the thermosetting first protective film-forming film to form the first protective film are not particularly limited as long as the first protective film is cured to a degree that allows it to fully perform its function, and may be appropriately selected depending on the type of thermosetting first protective film-forming film, etc. For example, the heating temperature during thermal curing of the thermosetting first protective film-forming film is preferably 100 to 200° C., and may be, for example, any one of 110 to 170° C. and 120 to 150° C. The heating time during thermal curing is preferably 0.5 to 5 hours, and may be, for example, any one of 0.5 to 4 hours and 1 to 3 hours.

[0048] <Thermosetting first protective film forming composition> Examples of the composition for forming a thermosetting first protective film include a composition for forming a thermosetting first protective film (III) (sometimes simply referred to as "composition (III)" in this specification) containing a polymer component (A), a thermosetting component (B), a curing accelerator (C), a filler (D), and an additive (I).

[0049] [Polymer component (A)] The polymer component (A) is a polymer compound for imparting film-forming properties, flexibility, etc. to the thermosetting first protective film-forming film. In this specification, the polymer compound also includes products of polycondensation reactions.

[0050] The polymer component (A) contained in the composition (III) and the thermosetting first protective film-forming film may be only one type, or may be two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0051] Examples of the polymer component (A) include polyvinyl acetal, acrylic resin, urethane resin, phenoxy resin, silicone resin, saturated polyester resin, and the like. Of these, the polymer component (A) is preferably polyvinyl acetal.

[0052] The polyvinyl acetal in the polymer component (A) may be any of the known polyvinyl acetals. Among them, 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.

[0053] [ka]

[0054] The weight average molecular weight (Mw) of the polyvinyl acetal is preferably 5000 to 200000, and more preferably 8000 to 100000. When the weight average molecular weight of the polyvinyl acetal is in such a range, the effect of suppressing the thermosetting first protective film-forming film from remaining on the upper part of the bump when the thermosetting first protective film-forming film is attached to the bump-forming surface is enhanced.

[0055] In this specification, unless otherwise specified, the "weight average molecular weight" is a polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0056] The glass transition temperature (Tg) of the polyvinyl acetal is preferably 40 to 80° C., and more preferably 50 to 70° C. When the Tg of the polyvinyl acetal is in such a range, the effect of suppressing the thermosetting first protective film-forming film from remaining on the upper part of the bump when the thermosetting first protective film-forming film is attached to the bump-forming surface is enhanced.

[0057] The ratio of the three or more monomers constituting the polyvinyl acetal can be selected arbitrarily.

[0058] 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 1000000, and more preferably 8000 to 800000. When the weight average molecular weight of the acrylic resin is in such a range, the effect of suppressing the first thermosetting protective film-forming film from remaining on the upper part of the bump when the first thermosetting protective film-forming film is attached to the bump-forming surface is enhanced.

[0059] The glass transition temperature (Tg) of the acrylic resin is preferably −50 to 70° C., and more preferably −30 to 60° C. When the Tg of the acrylic resin is in such a range, the effect of suppressing the first thermosetting protective film-forming film from remaining on the upper part of the bump when the first thermosetting protective film-forming film is attached to the bump-forming surface is enhanced.

[0060] When the acrylic resin has two or more kinds of structural units, the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox formula. The Tg of the monomer from which the structural unit is derived can be the value listed in the Polymer Data Handbook or the Adhesive Handbook.

[0061] The monomer constituting the acrylic resin may be of only one type, or may be of two or more types, and when it is of two or more types, the combination and ratio thereof can be selected arbitrarily.

[0062] Examples of the acrylic resin 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.

[0063] In this specification, the term "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid. For example, "(meth)acrylate" is a concept that includes both "acrylate" and "methacrylate," and "(meth)acryloyl group" is a concept that includes both "acryloyl group" and "methacryloyl group."

[0064] 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 methyl (meth)acrylate. p) (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure having 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 of the substituted amino group-containing (meth)acrylic acid ester include N-methylaminoethyl (meth)acrylate. Here, the term "substituted amino group" refers to a group having a structure in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom.

[0065] The acrylic resin may have a functional group capable of bonding with other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, etc. The functional group of the acrylic resin may be bonded with other compounds via a crosslinking agent (F) described later, or may be bonded directly with other compounds without the crosslinking agent (F). When the acrylic resin is bonded with other compounds via the functional group, for example, the reliability of the package obtained by using the thermosetting first protective film-forming film tends to be improved.

[0066] In the composition (III), the ratio of the content of the polymer component (A) to the total content of all components other than the solvent is preferably 5 to 25 mass%, and more preferably 5 to 15 mass%, regardless of the type of the polymer component (A). This is equivalent to saying that the content ratio of polymer component (A) in the thermosetting first protective film-forming film to the total mass of the thermosetting first protective film-forming film is preferably 5 to 25 mass%, and more preferably 5 to 15 mass%, regardless of the type of polymer component (A). This is based on the fact that the amount of components other than the solvent does not usually change during the process of removing the solvent from the resin composition containing the solvent to form the resin film, and the content ratio of the components other than the solvent is the same between the resin composition and the resin film. Therefore, in this specification, not only in the case of the thermosetting first protective film-forming film, but also in the case of the resin film obtained by removing the solvent from the resin composition, the content of the components other than the solvent will be described below.

[0067] The polymer component (A) may also correspond to the thermosetting component (B). In this embodiment, when the composition (III) contains a component that corresponds to both the polymer component (A) and the thermosetting component (B), the composition (III) is considered to contain the polymer component (A) and the thermosetting component (B).

[0068] [Thermosetting component (B)] The thermosetting component (B) has thermosetting properties and is a component for thermally curing the thermosetting first protective film-forming film.

[0069] The thermosetting component (B) contained in the composition (III) and the thermosetting first protective film-forming film may be only one type, or may be two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0070] Examples of the thermosetting component (B) include epoxy-based thermosetting resins, thermosetting polyimide resins, and unsaturated polyester resins, with epoxy-based thermosetting resins being preferred. In this specification, the thermosetting polyimide resin is a general term for a polyimide precursor that forms a polyimide resin by thermal curing, and a thermosetting polyimide.

[0071] (Epoxy thermosetting resin) The epoxy thermosetting resin comprises an epoxy resin (B1) and a thermosetting agent (B2). The epoxy-based thermosetting resin contained in composition (III) and the thermosetting first protective film-forming film may be only one type or two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0072] Epoxy resin (B1) The epoxy resin (B1) may be any known epoxy resin, such as a polyfunctional epoxy resin, a biphenyl compound, bisphenol A diglycidyl ether and its hydrogenated product, orthocresol novolac epoxy resin, a dicyclopentadiene type epoxy resin, a biphenyl type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a phenylene skeleton type epoxy resin.

[0073] The epoxy resin (B1) may be an epoxy resin having an unsaturated hydrocarbon group. The epoxy resin having an unsaturated hydrocarbon group has higher compatibility with acrylic resin than the epoxy resin having no unsaturated hydrocarbon group. Therefore, by using the epoxy resin having an unsaturated hydrocarbon group, for example, the reliability of the package obtained by using the thermosetting first protective film-forming film tends to be improved.

[0074] Examples of epoxy resins having unsaturated hydrocarbon groups include compounds having a structure in which a part of the epoxy groups of a polyfunctional epoxy resin is converted to a group having an unsaturated hydrocarbon group. Such compounds can be obtained, for example, by subjecting an epoxy group to an addition reaction with (meth)acrylic acid or a derivative thereof. Furthermore, examples of epoxy resins having an unsaturated hydrocarbon group include compounds having a structure 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.

[0075] The number average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoints of the curability of the thermosetting first protective film-forming film and the strength and heat resistance of the cured product of the thermosetting first protective film-forming film (e.g., the first 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 from 100 to 1000 g / eq, and more preferably from 200 to 800 g / eq.

[0076] 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.

[0077] ·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 capable of reacting with an epoxy group in one molecule. The functional group may, for example, be a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, or an anhydride group of an acid group, and the like. The phenolic hydroxyl group, the amino group, or an anhydride group of an acid group is preferred, and the phenolic hydroxyl group or the amino group is more preferred.

[0078] 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").

[0079] The heat curing agent (B2) may have an unsaturated hydrocarbon group. Examples of the heat curing agent (B2) having an unsaturated hydrocarbon group include a compound having a structure in which some of the hydroxyl groups of a phenol resin are substituted with a group having an unsaturated hydrocarbon group, and a compound having a structure in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring of a phenol resin. The unsaturated hydrocarbon group in the heat curing agent (B2) is the same as the unsaturated hydrocarbon group in the above-mentioned epoxy resin having an unsaturated hydrocarbon group.

[0080] Of the thermosetting agents (B2), for example, the number average molecular weight of resin components such as polyfunctional phenol resins, novolac type phenol resins, dicyclopentadiene type phenol resins, and aralkyl type phenol 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 components, such as biphenol and dicyandiamide, is not particularly limited, but is preferably 60 to 500, for example.

[0081] 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.

[0082] In the thermosetting first protective film-forming 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, relative to 100 parts by mass of the epoxy resin (B1). When the content of the thermosetting agent (B2) is equal to or more than the lower limit, the curing of the thermosetting first protective film-forming film is more likely to proceed. When the content of the thermosetting agent (B2) is equal to or less than the upper limit, the moisture absorption rate of the thermosetting first protective film-forming film is reduced, and, for example, the reliability of the package obtained using the thermosetting first protective film-forming film is further improved.

[0083] In the thermosetting first protective film-forming film, the content of the thermosetting component (B) (for example, the total content of the epoxy resin (B1) and the thermosetting agent (B2)) is preferably 600 to 1000 parts by mass per 100 parts by mass of the polymer component (A). When the content of the thermosetting component (B) is in such a range, when the thermosetting first protective film-forming film is attached to the bump-forming surface, the effect of suppressing the thermosetting first protective film-forming film from remaining on the upper part of the bump is enhanced, and a hard first protective film can be formed. Furthermore, in order to obtain such effects more significantly, the content of the thermosetting component (B) may be appropriately adjusted depending on the type of the polymer component (A).

[0084] For example, when the polymer component (A) is the polyvinyl acetal, in the thermosetting first protective film-forming film, the content of the thermosetting component (B) is preferably 600 to 1,000 parts by mass, more preferably 600 to 900 parts by mass, and even more preferably 600 to 800 parts by mass per 100 parts by mass of the polymer component (A).

[0085] [Cure accelerator (C)] The curing accelerator (C) 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.

[0086] The curing accelerator (C) contained in the composition (III) and the thermosetting first protective film-forming film may be of only one type or of two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0087] In the thermosetting first protective film-forming film, the content of the curing accelerator (C) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the content of the thermosetting component (B). When the content of the curing accelerator (C) is equal to or more than the lower limit, the effect of using the curing accelerator (C) is more remarkable. 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 to the adhesive interface with the adherend under high temperature and high humidity conditions in the thermosetting first protective film-forming film and segregating therein is enhanced, and for example, the reliability of the package obtained using the thermosetting first protective film-forming film is further improved.

[0088] [Filling material (D)] By adjusting the amount of the composition (III) and the filler (D) in the thermosetting first protective film-forming film, when the thermosetting first protective film-forming film is attached to the bump-forming surface, the effect of suppressing the remaining of the thermosetting first protective film-forming film on the upper part of the bump can be adjusted. In addition, the thermal expansion coefficient of the cured product of the thermosetting first protective film-forming film (e.g., the first protective film) can be more easily adjusted. For example, by optimizing the thermal expansion coefficient of the first protective film for the object on which the first protective film is formed, the reliability of the package obtained by using the thermosetting first protective film-forming film is further improved. In addition, as described later, in order to form the first protective film not only on the bump-forming surface of the semiconductor chip but also on the side surface, when filling the grooves provided on the bump-forming surface of the semiconductor wafer with the first protective film-forming film, the degree of filling can be adjusted. In addition, by using the thermosetting first protective film-forming film containing the filler (D), the moisture absorption rate of the cured product of the thermosetting first protective film-forming film (e.g., the first protective film) can be reduced and the heat dissipation can be improved.

[0089] 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, and the like; beads obtained by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; glass fibers, and the like. Among these, the inorganic filler is preferably silica or alumina.

[0090] The filler (D) contained in the composition (III) and the thermosetting first protective film-forming film may be of only one type or of two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0091] In the thermosetting first protective film-forming film, the content ratio of the filler (D) to the total mass of the thermosetting first protective film-forming film is preferably 5 to 45 mass%, more preferably 5 to 40 mass%, and even more preferably 5 to 30 mass%. By having the ratio in such a range, when the thermosetting first protective film-forming film is attached to the bump-forming surface, the effect of suppressing the thermosetting first protective film-forming film from remaining on the upper part of the bump is enhanced, and the thermal expansion coefficient can be more easily adjusted.

[0092] [Additives (I)] By adjusting the type or amount of additive (I) in composition (III) and the thermosetting first protective film-forming film, the effect of suppressing the residue of the thermosetting first protective film-forming film on the top of the bump when the thermosetting first protective film-forming film is attached to the bump-forming surface can be adjusted. Among them, examples of the additive (I) that are preferable in terms of increasing the effect of suppressing the remaining of the thermosetting first protective film-forming film include a rheology control agent, a surfactant, and silicone oil.

[0093] More specifically, examples of the rheology control agent include polyhydroxycarboxylic acid esters, polyvalent carboxylic 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 hydroxyl groups; and groups having an unsaturated bond such as vinyl groups and phenyl groups.

[0094] In addition to the above, the additive (I) may also include various other general-purpose additives such as plasticizers, antistatic agents, antioxidants, gettering agents, ultraviolet absorbers, and tackifiers.

[0095] The additive (I) contained in the composition (III) and the thermosetting first protective film-forming film may be of only one type or of two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0096] The content of the composition (III) and the additive (I) in the thermosetting first protective film-forming film is not particularly limited, and can be appropriately adjusted depending on the type and purpose. For example, when the purpose is to adjust the effect of suppressing the remaining of the above-mentioned thermosetting first protective film-forming film, the content ratio of additive (I) in the thermosetting first protective film-forming film relative to the total mass of the thermosetting first protective film-forming film is preferably 0.5 to 10 mass%, more preferably 0.5 to 7 mass%, and even more preferably 0.5 to 5 mass%.

[0097] [Coupling agent (E)] The composition (III) and the thermosetting first protective film-forming 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 first protective film-forming film to an adherend can be improved. In addition, by using the coupling agent (E), the cured product of the thermosetting first protective film-forming film (e.g., the first protective film) has improved water resistance without impairing heat resistance.

[0098] The coupling agent (E) is preferably a compound having a functional group capable of reacting with the functional groups 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 the silane include bis(3-(aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazole silane.

[0099] The coupling agent (E) contained in the composition (III) and the thermosetting first protective film-forming film may be only one type or two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0100] When the coupling agent (E) is used, the content of the coupling agent (E) in the thermosetting first protective film-forming film may be, for example, 0.03 to 20 parts by mass relative to 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 more than the lower limit, the effects of using the coupling agent (E), such as improvement in dispersibility of the filler (D) in the resin and improvement in adhesion of the thermosetting first protective film-forming film to the adherend, are more significantly obtained. When the content of the coupling agent (E) is equal to or less than the upper limit, the generation of outgassing is more suppressed.

[0101] [Crosslinker (F)] When the polymer component (A) has a functional group capable of bonding with 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 composition (III) and the thermosetting first protective film-forming film may contain a crosslinking agent (F). The crosslinking agent (F) is a component for bonding the functional group in the polymer component (A) with other compounds to crosslink the functional group, and by crosslinking in this manner, the initial adhesive strength and cohesive strength of the thermosetting first protective film-forming film can be adjusted.

[0102] 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).

[0103] 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 terminal isocyanate urethane prepolymers, which are reaction products of the aromatic polyisocyanate compounds, etc., and 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 a xylylene diisocyanate adduct of trimethylolpropane, as described below. In this specification, the term "isocyanate-terminated urethane prepolymer" refers to a prepolymer having a urethane bond and an isocyanate group at the terminal of the molecule.

[0104] 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 a portion of the hydroxyl groups of a polyol such as trimethylolpropane; lysine diisocyanate, and the like.

[0105] Examples of the organic polyvalent imine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-toluene-2,4-bis(1-aziridinecarboxamide)triethylenemelamine, and the like.

[0106] 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 first protective film-forming film by the reaction between the crosslinking agent (F) and the polymer component (A).

[0107] The crosslinking agent (F) contained in the composition (III) and the thermosetting first protective film-forming film may be of only one type or of two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0108] When the crosslinking agent (F) is used, the content of the crosslinking agent (F) in the composition (III) may be, for example, 0.01 to 20 parts by mass relative to 100 parts by mass of the polymer component (A). When the content of the crosslinking agent (F) is equal to or more than the lower limit, the effect of using the crosslinking agent (F) is more remarkable. 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.

[0109] [Other ingredients] The composition (III) and the thermosetting first protective film-forming film may contain other components that do not fall under any of the above-mentioned polymer component (A), thermosetting component (B), curing accelerator (C), filler (D), additive (I), coupling agent (E), and crosslinking agent (F), within a range that does not impair the effects of the present invention. Examples of the other components include an energy ray curable resin and a photopolymerization initiator.

[0110] The other components contained in composition (III) and the thermosetting first protective film-forming film may be of only one type or of two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily. The contents of the composition (III) and the other components in the thermosetting first protective film-forming film are not particularly limited and may be appropriately selected depending on the purpose.

[0111] [solvent] It is preferable that the composition (III) further contains a solvent. The composition (III) containing a solvent has good handleability. 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.

[0112] For example, an example of a preferred thermosetting first protective film-forming film, in terms of improving the high-speed application ability of the first protective film-forming sheet described below and the penetrability of the first protective film-forming film, and making it easier to adjust the peel force between the intermediate release layer and the first protective film-forming film to the desired range, is one that contains a polymer component (A), a thermosetting component (B), a curing accelerator (C), a filler (D), and an additive (I), and in the thermosetting first protective film-forming film, the ratio of the total content of the polymer component (A), the thermosetting component (B), the curing accelerator (C), the filler (D), and the additive (I) to the total mass of the thermosetting first protective film-forming film is 85 mass% or more, preferably 90 mass% or more, and more preferably 95 mass% or more. In view of the above, an example of a more preferred thermosetting first protective film-forming film includes a film containing a polymer component (A), a thermosetting component (B), a curing accelerator (C), a filler (D), and an additive (I), in which the polymer component (A) is polyvinyl acetal, the thermosetting component (B) is an epoxy resin (B1) and a thermosetting agent (B2), and the additive (I) is one or more selected from the group consisting of a rheology control agent, a surfactant, and a silicone oil, and in the thermosetting first protective film-forming film, the total content ratio of the polymer component (A), the thermosetting component (B), the curing accelerator (C), the filler (D), and the additive (I) to the total mass of the thermosetting first protective film-forming film is 85 mass% or more, preferably 90 mass% or more, and more preferably 95 mass% or more. The thickness of these thermosetting first protective film-forming films is preferably 2 to 7 times, and more preferably 3 to 6 times, the thickness of the intermediate release layer.

[0113] <Method for producing the composition for forming the thermosetting first protective film> The thermosetting composition for forming the first protective film, such as composition (III), can be obtained by blending the respective components constituting 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, a method of mixing by adding ultrasound, etc. The temperature and time during addition and mixing of 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.

[0114] Energy ray curable first protective film The energy ray-curable first protective film-forming film may, for example, contain an energy ray-curable component (a), a filler, and an additive.

[0115] The curing conditions when curing the energy ray-curable first protective film-forming film to form the first protective film are not particularly limited as long as the first protective film is cured to a degree that allows it to fully perform its function, and may be appropriately selected depending on the type of energy ray-curable first protective film-forming film, etc. For example, the illuminance of the energy ray during curing of the energy ray-curable first protective film-forming film is 180 to 280 mW / cm 2 The amount of energy rays during the curing is preferably 450 to 1000 mJ / cm. 2 It is preferable that:

[0116] <Energy ray-curable composition for forming first protective film> Examples of the energy ray-curable composition for forming a first protective film include an energy ray-curable composition for forming a first protective film (IV) (sometimes simply referred to as "composition (IV)" in this specification) that contains an energy ray-curable component (a), a filler, and an additive.

[0117] [Energy ray curable component (a)] The energy ray-curable component (a) is a component that is cured by irradiation with energy rays, and is also a component that imparts film-forming properties, flexibility, and the like to the energy ray-curable first protective film-forming film. The energy ray-curable component (a) is preferably uncured and preferably has adhesive properties, and more preferably is uncured and has adhesive properties.

[0118] Examples of the energy ray curable component (a) include a polymer (a1) having an energy ray curable group and a weight average molecular weight of 80000 to 2000000, and a compound (a2) having an energy ray curable group and a molecular weight of 100 to 80000. The polymer (a1) may be at least partially crosslinked with a crosslinking agent, or may not be crosslinked.

[0119] (Polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80,000 to 2,000,000) An example of the polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80,000 to 2,000,000 includes an acrylic resin (a1-1) having a structure obtained by polymerizing an acrylic polymer (a11) having a functional group capable of reacting with a group possessed by another compound, and an energy ray-curable compound (a12) having a group reactive with the functional group and an energy ray-curable group such as an energy ray-curable double bond.

[0120] Examples of the functional group capable of reacting with a group possessed by another compound include a hydroxyl group, a carboxy group, an amino group, a substituted amino group (a group having a structure in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom), an epoxy group, etc. However, from the viewpoint of preventing corrosion of circuits of a semiconductor wafer, a semiconductor chip, etc., it is preferable that the functional group is a group other than a carboxy group. Of these, the functional group is preferably a hydroxyl group.

[0121] Acrylic polymers having functional groups (a11) The acrylic polymer (a11) having a functional group may, for example, be one having a structure in which an acrylic monomer having the functional group and an acrylic monomer not having the functional group are copolymerized, and may also be one having a structure in which a monomer other than the acrylic monomer (non-acrylic monomer) is further copolymerized in addition to these monomers. The acrylic polymer (a11) may be a random copolymer or a block copolymer.

[0122] Examples of the acrylic monomer having a functional group include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, a substituted amino group-containing monomer, and an epoxy group-containing monomer.

[0123] Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth)acrylates 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; and non-(meth)acrylic unsaturated alcohols (unsaturated alcohols not having a (meth)acryloyl skeleton) such as vinyl alcohol and allyl alcohol.

[0124] Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth)acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as fumaric acid, itaconic acid, maleic acid and citraconic acid; anhydrides of the ethylenically unsaturated dicarboxylic acids; and (meth)acrylic acid carboxyalkyl esters such as 2-carboxyethyl methacrylate.

[0125] The acrylic monomer having a functional group is preferably a hydroxyl group-containing monomer or a carboxyl group-containing monomer, and more preferably a hydroxyl group-containing monomer.

[0126] The acrylic monomer having a functional group constituting the acrylic polymer (a11) may be of only one kind, or of two or more kinds. When there are two or more kinds, the combination and ratio thereof can be selected arbitrarily.

[0127] Examples of the acrylic monomer not having a functional group 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, isopropyl (meth)acrylate, n-butyl (meth)acrylate, ethyl ... Examples of (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure having 1 to 18 carbon atoms include sononyl, 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).

[0128] Examples of the acrylic monomer not having a functional group include alkoxyalkyl group-containing (meth)acrylic acid esters such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate; (meth)acrylic acid esters having an aromatic group, including (meth)acrylic acid aryl esters such as phenyl (meth)acrylate; non-crosslinkable (meth)acrylamide and derivatives thereof; and (meth)acrylic acid esters having a non-crosslinkable tertiary amino group, such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.

[0129] The acrylic monomer not having a functional group constituting the acrylic polymer (a11) may be of only one kind or of two or more kinds, and when it is of two or more kinds, the combination and ratio thereof can be arbitrarily selected.

[0130] Examples of the non-acrylic monomer include olefins such as ethylene and norbornene; vinyl acetate; and styrene. The non-acrylic monomer constituting the acrylic polymer (a11) may be of only one kind, or may be of two or more kinds. When it is of two or more kinds, the combination and ratio thereof can be selected arbitrarily.

[0131] In the acrylic polymer (a11), the ratio (content) of the amount of the structural unit derived from the acrylic monomer having the functional group to the total amount of the structural units constituting the acrylic polymer (a11) is preferably 0.1 to 50 mass%, more preferably 1 to 40 mass%, and particularly preferably 3 to 30 mass%. When the ratio is in such a range, the content of the energy ray curable group in the acrylic resin (a1-1) obtained by copolymerization of the acrylic polymer (a11) and the energy ray curable compound (a12) makes it possible to easily adjust the degree of curing of the cured product (e.g., first protective film) of the energy ray curable first protective film-forming film to a preferred range.

[0132] The acrylic polymer (a11) constituting the acrylic resin (a1-1) may be of only one kind, or may be of two or more kinds. When there are two or more kinds, the combination and ratio thereof can be selected arbitrarily.

[0133] In the energy ray-curable first protective film-forming film, the content ratio of the acrylic resin (a1-1) relative to the total mass of the energy ray-curable first protective film-forming film is preferably 1 to 40 mass%, more preferably 2 to 30 mass%, and particularly preferably 3 to 20 mass%.

[0134] Energy ray curable compounds (a12) The energy ray curable compound (a12) preferably has one or more groups selected from the group consisting of an isocyanate group, an epoxy group, and a carboxy group as a group capable of reacting with the functional group of the acrylic polymer (a11), and more preferably has an isocyanate group as the group. For example, when the energy ray curable compound (a12) has an isocyanate group as the group, the isocyanate group easily reacts with the hydroxyl group of the acrylic polymer (a11) having a hydroxyl group as the functional group.

[0135] The energy ray-curable compound (a12) preferably has 1 to 5, and more preferably 1 or 2, energy ray-curable groups in one molecule.

[0136] Examples of the energy ray-curable compound (a12) include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate; an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate; Examples of the isocyanate include an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate. Among these, the energy ray-curable compound (a12) is preferably 2-methacryloyloxyethyl isocyanate.

[0137] The energy ray-curable compound (a12) constituting the acrylic resin (a1-1) may be of only one type, or of two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0138] In the acrylic resin (a1-1), the content ratio of the energy ray curable group derived from the energy ray curable compound (a12) to the content of the functional group derived from the acrylic polymer (a11) is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. When the content ratio is in such a range, the adhesive strength of the cured product (for example, the first protective film) of the energy ray curable first protective film-forming film becomes larger. Note that, when the energy ray curable compound (a12) is a monofunctional compound (having one of the groups in one molecule), the upper limit of the content ratio is 100 mol%, but when the energy ray curable compound (a12) is a polyfunctional compound (having two or more of the groups in one molecule), the upper limit of the content ratio may exceed 100 mol%.

[0139] The weight average molecular weight (Mw) of the polymer (a1) is preferably from 100,000 to 2,000,000, and more preferably from 300,000 to 1,500,000.

[0140] When the polymer (a1) is at least partially crosslinked with a crosslinking agent, the polymer (a1) may be crosslinked at the group reactive with the crosslinking agent by polymerization of a monomer which does not correspond to any of the above-mentioned monomers described as constituting the acrylic polymer (a11) and has a group reactive with the crosslinking agent, or the polymer (a1) may be crosslinked at a group reactive with the functional group derived from the energy ray-curable compound (a12).

[0141] The polymer (a1) contained in the composition (IV) and the energy ray-curable first protective film-forming 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.

[0142] (Compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80,000) The energy ray-curable group in the compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80,000 includes a group containing an energy ray-curable double bond, and preferred examples thereof include a (meth)acryloyl group and a vinyl group.

[0143] The compound (a2) is not particularly limited as long as it satisfies the above conditions, and examples of the compound (a2) include a low molecular weight compound having an energy ray-curable group, an epoxy resin having an energy ray-curable group, and a phenol resin having an energy ray-curable group.

[0144] Among the compounds (a2), examples of the low molecular weight compound having an energy ray-curable group include polyfunctional monomers or oligomers, and acrylate compounds having a (meth)acryloyl group are preferred. Examples of the acrylate-based compound include 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxydiethoxy)phenyl]propane, 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene, 2,2-bis[4-((meth)acryloxypolypropoxy)phenyl]propane, tricyclodecane dimethanol di(meth)acrylate, 1,10-decane diol di(meth)acrylate, 1,2-dimethylphenyl di(meth)acrylate, 1,3-dimethylphenyl di(meth)acrylate, 1,4-dimethylphenyl di(meth)acrylate, 1,5-dimethylphenyl di(meth)acrylate, 1,6-dimethylphenyl di(meth)acrylate, 1,7-dimethylphenyl di(meth)acrylate, 1,8-dimethylphenyl di(meth)acrylate, 1,9-dimethylphenyl di(meth)acrylate, 1,10-dimethylphenyl ... bifunctional (meth)acrylates such as 6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2-bis[4-((meth)acryloxyethoxy)phenyl]propane, neopentyl glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, and 2-hydroxy-1,3-di(meth)acryloxypropane; polyfunctional (meth)acrylates such as tris(2-(meth)acryloxyethyl)isocyanurate, ε-caprolactone-modified tris-(2-(meth)acryloxyethyl)isocyanurate, ethoxylated glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; Examples of the polyfunctional (meth)acrylate oligomer include urethane (meth)acrylate oligomer.

[0145] Among the compounds (a2), examples of the epoxy resin having an energy ray curable group and the phenolic resin having an energy ray curable group include those described in paragraph 0043 of JP 2013-194102 A. Although such resins also fall under the category of resins constituting the thermosetting component described below, in this embodiment they are treated as the compound (a2).

[0146] The weight average molecular weight of the compound (a2) is preferably from 100 to 30,000, and more preferably from 300 to 10,000.

[0147] The compound (a2) contained in the composition (IV) and the energy ray-curable first protective film-forming 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.

[0148] [Polymer (b) having no energy ray-curable group] When the composition (IV) and the energy ray curable first protective film-forming film contain the compound (a2) as the energy ray curable component (a), it is preferable that they further contain a polymer (b) that does not have an energy ray curable group. The polymer (b) may be at least partially crosslinked with a crosslinking agent, or may not be crosslinked.

[0149] Examples of the polymer (b) having no energy ray-curable group include acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber-based resins, and acrylic urethane resins. Among these, the polymer (b) is preferably an acrylic polymer (hereinafter sometimes abbreviated as "acrylic polymer (b-1)").

[0150] The acrylic polymer (b-1) may be a known one, and may be, for example, a homopolymer of one kind of acrylic monomer, a copolymer of two or more kinds of acrylic monomers, or a copolymer of one or more kinds of acrylic monomers and one or more kinds of monomers other than the acrylic monomers (non-acrylic monomers).

[0151] Examples of the acrylic monomer constituting the acrylic polymer (b-1) include (meth)acrylic acid alkyl esters, (meth)acrylic acid esters having a cyclic skeleton, glycidyl group-containing (meth)acrylic acid esters, hydroxyl group-containing (meth)acrylic acid esters, substituted amino group-containing (meth)acrylic acid esters, etc. Here, the "substituted amino group" is as explained above.

[0152] Examples of the (meth)acrylic acid alkyl ester include the same as the acrylic monomer not having a functional group (e.g., a (meth)acrylic acid alkyl ester in which the alkyl group constituting the alkyl ester has a chain structure having 1 to 18 carbon atoms) constituting the acrylic polymer (a11) described above.

[0153] Examples of the (meth)acrylic acid ester having a cyclic skeleton include cycloalkyl (meth)acrylic acid 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 are included.

[0154] The glycidyl group-containing (meth)acrylic acid ester may, for example, be glycidyl (meth)acrylate. Examples of the hydroxyl group-containing (meth)acrylic acid ester include 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. The substituted amino group-containing (meth)acrylic acid ester may, for example, be N-methylaminoethyl (meth)acrylate.

[0155] Examples of the non-acrylic monomer constituting the acrylic polymer (b-1) include olefins such as ethylene and norbornene; vinyl acetate; and styrene.

[0156] The polymer (b) having no energy ray-curable group and at least a portion of which is crosslinked with a crosslinking agent may be, for example, a polymer in which a reactive functional group in the polymer (b) has reacted with a crosslinking agent. The reactive functional group may be appropriately selected according to the type of crosslinking agent, and is not particularly limited. For example, when the crosslinking agent is a polyisocyanate compound, the reactive functional group may be a hydroxyl group, a carboxyl group, an amino group, etc., and among these, a hydroxyl group having high reactivity with an isocyanate group is preferred. When the crosslinking agent is an epoxy compound, the reactive functional group may be a carboxyl group, an amino group, an amide group, etc., and among these, a carboxyl group having high reactivity with an epoxy group is preferred. However, from the viewpoint of preventing corrosion of the circuits of a semiconductor wafer or a semiconductor chip, the reactive functional group is preferably a group other than a carboxyl group.

[0157] The polymer (b) having the reactive functional group and not having the energy ray curable group may be, for example, one obtained by polymerizing at least a monomer having the reactive functional group. In the case of the acrylic polymer (b-1), one or both of the acrylic monomer and the non-acrylic monomer listed as the monomers constituting the polymer may be one having the reactive functional group. The polymer (b) having a hydroxyl group as a reactive functional group may be, for example, one obtained by polymerizing a hydroxyl group-containing (meth)acrylic acid ester, and may also be one obtained by polymerizing a monomer having a structure in which one or more hydrogen atoms in the acrylic monomer or non-acrylic monomer listed above are replaced with the reactive functional group.

[0158] In the polymer (b) having a reactive functional group, the ratio (content) of the amount of the structural unit derived from the monomer having a reactive functional group to the total amount of the structural units constituting the polymer (b) is preferably 1 to 20 mass%, more preferably 2 to 10 mass%. When the ratio is in such a range, the degree of crosslinking in the polymer (b) becomes a more preferable range.

[0159] The weight average molecular weight (Mw) of the polymer (b) having no energy ray-curable group is preferably from 10,000 to 2,000,000, and more preferably from 100,000 to 1,500,000, in terms of improving the film-forming property of the composition (IV).

[0160] The polymer (b) not having an energy ray-curable group contained in the composition (IV) and the energy ray-curable first protective film-forming film may be only one type or may be two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0161] The composition (IV) may contain either one or both of the polymer (a1) and the compound (a2). When the composition (IV) contains the compound (a2), it is preferable that the composition (IV) further contains the polymer (b) having no energy ray curable group, and in this case, it is also preferable that the composition (IV) further contains the (a1). The composition (IV) may not contain the compound (a2), and may contain both the polymer (a1) and the polymer (b) having no energy ray curable group.

[0162] When the composition (IV) contains the polymer (a1), the compound (a2), and the polymer (b) having no energy ray-curable group, the content of the compound (a2) in the composition (IV) is preferably 10 to 400 parts by mass, and more preferably 30 to 350 parts by mass, per 100 parts by mass of the total content of the polymer (a1) and the polymer (b) having no energy ray-curable group.

[0163] In the energy ray-curable first protective film-forming film, the ratio of the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group to the total mass of the energy ray-curable first protective film-forming film is preferably 5 to 90 mass%, more preferably 10 to 80 mass%, and particularly preferably 20 to 70 mass%. When the ratio is in such a range, the energy ray curability of the energy ray-curable first protective film-forming film becomes better.

[0164] [Filling material] By adjusting the amount of the filler in the composition (IV) and the energy ray curable first protective film-forming film, when the energy ray curable first protective film-forming film is attached to the bump-forming surface, the effect of suppressing the energy ray curable first protective film-forming film remaining on the upper part of the bump can be adjusted. In addition, the thermal expansion coefficient of the cured product of the energy ray curable first protective film-forming film (for example, the first protective film) can be more easily adjusted, and for example, by optimizing the thermal expansion coefficient of the first protective film for the object on which the first protective film is formed, the reliability of the package obtained by using the energy ray curable first protective film-forming film is further improved. In addition, as described later, in order to form the first protective film not only on the bump-forming surface of the semiconductor chip but also on the side surface, when filling the grooves provided on the bump-forming surface of the semiconductor wafer with the first protective film, the degree of filling can be adjusted. In addition, by using an energy ray-curable first protective film-forming film containing a filler, it is possible to reduce the moisture absorption rate of the cured product of the energy ray-curable first protective film-forming film (e.g., the first protective film) and improve the heat dissipation properties.

[0165] The filler contained in the composition (IV) and the energy ray curable first protective film-forming film is the same as the filler (D) contained in the composition (III) and the thermosetting first protective film-forming film described above.

[0166] The aspect of the inclusion of the filler in the composition (IV) and the energy ray curable first protective film-forming film may be the same as the aspect of the inclusion of the filler (D) in the composition (III) and the thermosetting first protective film-forming film.

[0167] The filler contained in the composition (IV) and the energy ray-curable first protective film-forming film may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0168] In the energy ray-curable first protective film-forming film, the content ratio of the filler to the total mass of the energy ray-curable first protective film-forming film may be, for example, 5 to 45 mass %. By having the ratio in such a range, when the energy ray-curable first protective film-forming film is attached to the bump-forming surface, the effect of suppressing the energy ray-curable first protective film-forming film from remaining on the upper part of the bump is enhanced, and the thermal expansion coefficient can be more easily adjusted.

[0169] [Additives] By adjusting the type or amount of additives in composition (IV) and the energy ray-curable first protective film-forming film, the effect of suppressing the remaining of the energy ray-curable first protective film-forming film on the top of the bump when the energy ray-curable first protective film-forming film is attached to the bump-forming surface can be adjusted.

[0170] The additives contained in the composition (IV) and the energy ray-curable first protective film-forming film are the same as the additives (I) contained in the composition (III) and the heat-curable first protective film-forming film described above. For example, examples of additives that are preferable in terms of being able to more easily adjust the effect of suppressing the remaining of the energy ray-curable first protective film-forming film include rheology control agents, surfactants, silicone oils, and the like.

[0171] The mode of inclusion of the additive in the composition (IV) and the energy ray curable first protective film-forming film may be the same as the mode of inclusion of the additive (I) in the composition (III) and the heat curable first protective film-forming film.

[0172] The additives contained in the composition (IV) and the energy ray-curable first protective film-forming 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.

[0173] The content of the additives in the composition (IV) and the energy ray-curable first protective film-forming film is not particularly limited, and can be appropriately adjusted depending on the type and purpose. For example, when the purpose is to adjust the effect of suppressing the remaining of the above-mentioned energy ray-curable first protective film-forming film, the content ratio of the additive in the energy ray-curable first protective film-forming film relative to the total mass of the energy ray-curable first protective film-forming film may be, for example, 0.5 to 10 mass%.

[0174] [Other ingredients] The composition (IV) and the energy ray curable first protective film-forming film may contain other components that do not fall under any of the energy ray curable component (a), the filler, the additive, and the polymer (b) not having an energy ray curable group, within a range that does not impair the effects of the present invention. Examples of the other components include a thermosetting component, a photopolymerization initiator, a coupling agent, a crosslinking agent, etc. For example, by using the composition (IV) containing the energy ray-curable component (a) and a thermosetting component, the adhesive strength of the energy ray-curable first protective film-forming film to an adherend is improved by heating, and the strength of the cured product of the energy ray-curable first protective film-forming film (e.g., the first protective film) is also improved.

[0175] The thermosetting component, photopolymerization initiator, coupling agent, and crosslinking agent in composition (IV) may be the same as the thermosetting component (B), photopolymerization initiator, coupling agent (E), and crosslinking agent (F) in composition (III), respectively.

[0176] The other components contained in composition (IV) and the energy ray-curable first protective film-forming film may be one type only or two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily. The contents of the composition (IV) and the other components in the energy ray-curable first protective film-forming film are not particularly limited, and may be appropriately selected depending on the purpose.

[0177] [solvent] Composition (IV) preferably further contains a solvent. Composition (IV) containing a solvent has good handleability. The content of the solvent in the composition (IV) is not particularly limited, and may be appropriately selected depending on, for example, the types of components other than the solvent.

[0178] For example, an example of a preferred energy ray-curable first protective film-forming film, in terms of improving the high-speed application ability of the first protective film-forming sheet described below and the penetrability of the first protective film-forming film, and making it easier to adjust the peel force between the intermediate release layer and the first protective film-forming film to a desired range, is one that contains an energy ray-curable component (a), a filler, and an additive, and in the energy ray-curable first protective film-forming film, the ratio of the total content of the energy ray-curable component (a), the filler, and the additive to the total mass of the energy ray-curable first protective film-forming film is 85 mass% or more, preferably 90 mass% or more, and more preferably 95 mass% or more. In view of the above, a more preferable example of the energy ray curable first protective film-forming film is a film that contains an energy ray curable component (a), a polymer (b) having no energy ray curable group, a filler, and an additive, and the energy ray curable component (a) is either or both of a polymer (a1) having an energy ray curable group and having a weight average molecular weight of 80,000 to 2,000,000, and a compound (a2) having an energy ray curable group and having a molecular weight of 100 to 80,000, and the polymer (b) not having an energy ray curable group is an acrylic polymer, a phenoxy resin, a urethane resin, a polyester, a rubber-based and the additive is one or more selected from the group consisting of a rheology control agent, a surfactant, and a silicone oil, and in the energy ray-curable first protective film-forming film, the total content of the energy ray-curable component (a), the polymer (b) not having an energy ray-curable group, the filler, and the additive is 85 mass% or more, preferably 90 mass% or more, and more preferably 95 mass% or more relative to the total mass of the energy ray-curable first protective film-forming film. The thickness of these energy ray-curable first protective film-forming films is preferably 2 to 7 times, and more preferably 3 to 6 times, the thickness of the intermediate release layer.

[0179] <Method for producing energy ray-curable composition for forming first protective film> The energy ray-curable composition for forming the first protective film, such as composition (IV), can be obtained by blending the respective components constituting the composition. The energy ray-curable composition for forming the first protective film can be produced in the same manner as the above-described heat-curable composition for forming the first protective film, except that the types of ingredients used are different.

[0180] ○Non-curable first protective film forming film The non-curable first protective film-forming film may contain, for example, a thermoplastic resin, a filler, and an additive.

[0181] <Non-curable first protective film forming composition (V)> Examples of compositions for forming a non-curable first protective film include a non-curable composition for forming a first protective film (V) (sometimes abbreviated in this specification as simply "composition (V)") that contains a thermoplastic resin, a filler, and an additive.

[0182] [Thermoplastic resin] The thermoplastic resin is not particularly limited. More specifically, examples of the thermoplastic resin include the same non-curable resins as those listed as components contained in the above-mentioned composition (III), such as polyvinyl acetal, acrylic resin, urethane resin, phenoxy resin, silicone resin, and saturated polyester resin.

[0183] The thermoplastic resin contained in composition (V) and the non-curable first protective film-forming film may be only one type or two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0184] In the non-curable first protective film-forming film, the content ratio of the thermoplastic resin to the total mass of the non-curable first protective film-forming film is preferably 25 to 75 mass %.

[0185] [Filling material] The non-curable first protective film-forming film containing the filler exhibits the same effects as the thermosetting first protective film-forming film containing the filler (D).

[0186] Examples of the filler contained in the composition (V) and the non-curable first protective film-forming film include the same filler (D) contained in the composition (III) and the thermosetting first protective film-forming film.

[0187] The filler contained in the composition (V) and the non-curable first protective film-forming film may be only one type, or may be two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0188] In the non-curable first protective film-forming film, the ratio of the content of the filler to the total mass of the non-curable first protective film-forming film is preferably 15 to 70 mass%. By the ratio being in such a range, similarly to the case where the composition (III) is used, when the non-curable first protective film-forming film is attached to the bump-forming surface, the effect of suppressing the non-curable first protective film-forming film remaining on the upper part of the bump becomes higher, and the thermal expansion coefficient of the non-curable first protective film-forming film and the first protective film becomes easier to adjust. In addition, as described later, when filling the non-curable first protective film-forming film into the grooves provided on the bump-forming surface of the semiconductor wafer in order to form the first protective film not only on the bump-forming surface of the semiconductor chip but also on the side surface, the non-curable first protective film-forming film can be filled sufficiently.

[0189] [Additives] By adjusting the type or amount of additives in composition (V) and the non-curable first protective film-forming film, the effect of suppressing the remaining of the non-curable first protective film-forming film on the top of the bump when the non-curable first protective film-forming film is attached to the bump-forming surface can be adjusted.

[0190] The additives contained in the composition (V) and the non-curable first protective film-forming film are the same as the additives (I) contained in the composition (III) and the thermosetting first protective film-forming film described above. For example, examples of additives that are preferable in terms of making it easier to adjust the effect of suppressing the remaining of the above-mentioned non-curable first protective film-forming film include rheology control agents, surfactants, silicone oils, and the like.

[0191] The mode of inclusion of the additive in the composition (V) and the non-curable first protective film-forming film may be the same as the mode of inclusion of the additive (I) in the composition (III) and the thermosetting first protective film-forming film.

[0192] The additives contained in the composition (V) and the non-curable first protective film-forming 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.

[0193] The content of the additives in the composition (V) and the non-curable first protective film-forming film is not particularly limited, and can be appropriately adjusted depending on the type and purpose. For example, when the purpose is to adjust the effect of suppressing the remaining of the above-mentioned non-curable first protective film-forming film, the content ratio of the additive in the non-curable first protective film-forming film relative to the total mass of the non-curable first protective film-forming film may be, for example, 0.5 to 10 mass%.

[0194] [Other ingredients] Composition (V) and the non-curable first protective film-forming film may contain other components that do not fall under any of the thermoplastic resins, fillers, and additives, within a range that does not impair the effects of the present invention. The other components are not particularly limited and can be selected arbitrarily depending on the purpose.

[0195] The other components contained in composition (V) and the non-curable first protective film-forming film may be of only one type or of two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily. The contents of the composition (V) and the other components in the non-curable first protective film-forming film are not particularly limited and may be appropriately selected depending on the purpose.

[0196] [solvent] Composition (V) preferably further contains a solvent, which provides good handleability. The content of the solvent in the composition (V) is not particularly limited, and may be appropriately selected depending on, for example, the types of components other than the solvent.

[0197] For example, an example of a preferred non-curable first protective film-forming film, in terms of improving the high-speed application ability of the first protective film-forming sheet described below and the penetrability of the first protective film-forming film, and making it easier to adjust the peel force between the intermediate release layer and the first protective film-forming film to the desired range, is one that contains a thermoplastic resin, a filler, and an additive, and in which the ratio of the total content of the thermoplastic resin, the filler, and the additive to the total mass of the non-curable first protective film-forming film is 85 mass% or more, preferably 90 mass% or more, and more preferably 95 mass% or more. In view of the above, an example of a more preferred non-curable first protective film-forming film is one which contains a thermoplastic resin, a filler, and an additive, wherein the thermoplastic resin is one or more selected from the group consisting of polyvinyl acetal, acrylic resin, urethane resin, phenoxy resin, silicone resin, and saturated polyester resin, and the additive is one or more selected from the group consisting of rheology control agents, surfactants, and silicone oils, and in the non-curable first protective film-forming film, the ratio of the total content of the thermoplastic resin, the filler, and the additive to the total mass of the non-curable first protective film-forming film is 85 mass% or more, preferably 90 mass% or more, and more preferably 95 mass% or more. The thickness of these non-curable first protective film-forming films is preferably 2 to 7 times, and more preferably 3 to 6 times, the thickness of the intermediate release layer.

[0198] <Method for producing composition for forming non-curable first protective film> The non-curable first protective film-forming composition such as composition (V) can be obtained by blending the respective components constituting the composition. The non-curable composition for forming the first protective film can be produced in the same manner as the above-described thermosetting composition for forming the first protective film, except that the types of ingredients used are different.

[0199] ◎ Intermediate peeling layer The intermediate release layer is a layer for improving the peelability of the first base material and the buffer layer from the first protective film-forming film after the first protective film-forming sheet is attached to the bump-forming surface of the semiconductor wafer. In addition, by adjusting the type of components contained in the intermediate release layer, the high-speed attachment property of the first protective film-forming sheet and the penetration property of the first protective film-forming film, which will be described later, can also be improved.

[0200] The intermediate release layer is preferably a resin layer containing a resin, and more preferably a non-curable (non-curable) resin layer.

[0201] The peel strength between the intermediate release layer and the first protective film-forming film in the test piece prepared from the sheet for forming a first protective film of this embodiment is 1000 mN / 25 mm or less, which results in good peelability of the laminate of the first substrate, the buffer layer, and the intermediate release layer in the sheet for forming a first protective film of this embodiment. The peel strength can be measured, for example, by the following method. That is, first, a test piece having a width of 25 mm is cut out from the first protective film-forming sheet. Next, in an environment of 23°C temperature and 50% relative humidity (RH), the peeling speed is set to 100mm / min, and the intermediate peeling layer is peeled off from the first protective film-forming film so that the surfaces of the intermediate peeling layer and the first protective film-forming film in the test piece that were in contact with each other form an angle of 180° (180° peeling is performed). More specifically, the laminate of the first substrate, the buffer layer and the intermediate peeling layer is peeled off from the first protective film-forming film in its length direction. Then, the load (peeling force) at this 180° peeling is measured, and the measured value at the first 5 mm length and the measured value at the last 5 mm length are excluded from the effective value, and the average value of the measured values ​​at the remaining length is adopted as the peeling force (mN / 25mm).

[0202] When measuring the peeling force, it is preferable to attach the entire exposed surface of the first protective film-forming film in the test piece to the surface of a hard support such as a stainless steel (SUS) plate via a double-sided tape in an environment of 23°C temperature and 50% relative humidity, and to measure the peeling force using the hard support with the test piece obtained in this way. In this way, the peeling force can be measured with higher accuracy. At this time, it is preferable to attach the test piece to the hard support using a rubber roller with a mass of 2 kg. It is preferable that the obtained hard support with the test piece is left as it is for 20 minutes in an environment of 23°C temperature and 50% relative humidity, and further placed in an oven heated to 90°C and left for 5 minutes. By leaving it in this way, the adhesive force between the first protective film-forming film in the hard support with the test piece and the double-sided tape is increased and stabilized. Furthermore, it is preferable that the hard support with the test piece is left to stand for 2 hours in an environment of 23°C temperature and 50% relative humidity after being left in this way. By further leaving the test piece still, the rigid support with the test piece attached thereto is subjected to a humidity conditioning treatment, and as a result, the peel force can be measured with higher accuracy.

[0203] In this embodiment, the peel strength between the intermediate release layer and the first protective film-forming film in the test piece may be, for example, 950 mN / 25 mm or less, 850 mN / 25 mm or less, or 760 mN / 25 mm or less. The smaller the peel strength, the higher the peelability of the laminate of the first substrate, the buffer layer, and the intermediate release layer. The lower limit of the peel strength is not particularly limited. In terms of better handleability of the first protective film-forming sheet, the peel strength is preferably 100 mN / 25 mm or more. In one embodiment, the peeling force may be, for example, any one of 100 to 1000 mN / 25 mm, 100 to 950 mN / 25 mm, 100 to 850 mN / 25 mm, and 100 to 760 mN / 25 mm, although these are just examples of the peeling force.

[0204] The peel force between the intermediate release layer and the first protective film-forming film in the test piece can be more easily adjusted by, for example, adjusting the components contained in the intermediate release layer and their contents (ie, composition).

[0205] For example, when the intermediate release layer is a resin layer, the resin is preferably an ethylene-vinyl acetate copolymer (EVA). When the intermediate release layer contains an ethylene-vinyl acetate copolymer, the peel force can be more easily reduced. The reason is unclear, but is presumed to be as follows. That is, the first protective film-forming film, regardless of whether it is curable or non-curable, and when it is curable, regardless of whether it is thermosetting or energy ray curable, usually contains a highly polar low molecular weight compound. Since the low molecular weight compound is easily transferred between layers, the low molecular weight compound in the first protective film-forming film is easily transferred to a layer adjacent to the first protective film-forming film. In the conventional first protective film-forming sheet, the interface between the first protective film-forming film and the layer adjacent thereto (e.g., adhesive layer) becomes unclear due to the interlayer transfer of such a low molecular weight compound, and as a result, it is presumed that the adhesive force between these layers becomes large, and the layer adjacent to the first protective film-forming film (e.g., adhesive layer) becomes difficult to peel off from the first protective film-forming film. In contrast, when the first protective film-forming sheet of the present embodiment has the intermediate release layer containing ethylene-vinyl acetate copolymer, the polarity of the ethylene-vinyl acetate copolymer is usually lower than the polarity of the low molecular weight compound, so it is assumed that the migration of the low molecular weight compound from the first protective film-forming film to the intermediate release layer is suppressed. As a result, it is assumed that the peeling force between the intermediate release layer and the first protective film-forming film is easily reduced.

[0206] In this embodiment, examples of the low molecular weight compound in the first protective film-forming film that is presumed to be suppressed from migrating to the intermediate release layer include monomers, oligomers, and inorganic compounds. Examples of the low molecular weight compound in the thermosetting first protective film-forming film include an epoxy resin (B1), a thermosetting agent (B2), a filler (D), and an additive (I). Examples of the low molecular weight compound in the energy ray curable first protective film-forming film include, among the compounds (a2) having an energy ray curable group, monomers or oligomers, fillers, photopolymerization initiators, additives, etc. Examples of the low molecular weight compound in the non-curable first protective film-forming film include a filler and an additive.

[0207] When the intermediate release layer contains an ethylene-vinyl acetate copolymer, the ratio of the amount (parts by mass) of the constituent units derived from vinyl acetate to the total amount of the constituent units (total amount of all the constituent units constituting the ethylene-vinyl acetate copolymer. The same applies below) (parts by mass) in the ethylene-vinyl acetate copolymer ([amount (parts by mass) of the constituent units derived from vinyl acetate constituting the ethylene-vinyl acetate copolymer] / [total amount (parts by mass) of all the constituent units constituting the ethylene-vinyl acetate copolymer]×100) is preferably 40% by mass or less. That is, the intermediate release layer contains an ethylene-vinyl acetate copolymer, and the ratio of the amount of the constituent units derived from vinyl acetate to the total amount of the constituent units in the ethylene-vinyl acetate copolymer is preferably 40% by mass or less. When the ratio is equal to or less than the upper limit, the peelability of the laminate of the first base material, the buffer layer and the intermediate release layer is better. This is because the smaller the ratio, the lower the polarity of the ethylene-vinyl acetate copolymer. In order to make such effects more pronounced, the ratio is more preferably 35% by mass or less, further preferably 30% by mass or less, and may be, for example, 25% by mass or less.

[0208] In this specification, the ratio of the amount (parts by mass) of structural units derived from vinyl acetate to the total amount (parts by mass) of structural units in an ethylene-vinyl acetate copolymer is sometimes referred to as the "VA content."

[0209] In the ethylene-vinyl acetate copolymer contained in the intermediate release layer, the ratio (VA content) of the amount (parts by mass) of the structural units derived from vinyl acetate to the total amount (parts by mass) of the structural units is preferably 10% by mass or more, and may be, for example, 15% by mass or more. When the ratio is equal to or more than the lower limit, the handleability of the composition for forming the intermediate release layer (composition (VII) described later) is improved, the intermediate release layer can be formed more easily, and the first protective film-forming sheet can be produced more easily.

[0210] In the ethylene-vinyl acetate copolymer, the ratio of the amount (parts by mass) of the structural units derived from vinyl acetate to the total amount (parts by mass) of the structural units (VA content) can be appropriately adjusted within a range set by arbitrarily combining any of the lower limit values ​​described above with any of the upper limit values ​​described above. In one embodiment, the ratio may be, for example, any of 10 to 40 mass%, 10 to 35 mass%, 10 to 30 mass%, and 10 to 25 mass% or less, or any of 15 to 40 mass%, 15 to 35 mass%, 15 to 30 mass%, and 15 to 25 mass% or less. However, these are just examples of the ratio (VA content).

[0211] The weight average molecular weight of the ethylene-vinyl acetate copolymer contained in the intermediate release layer is preferably 200,000 or less, more preferably 180,000 or less, and even more preferably 160,000 or less, and may be, for example, 100,000 or less or 60,000 or less. When the weight average molecular weight is equal to or less than the upper limit, the peelability of the laminate of the first base material, the buffer layer, and the intermediate release layer becomes better. Furthermore, the high-speed attachment property of the first protective film-forming sheet described later and the penetration property of the first protective film-forming film become higher.

[0212] The lower limit of the weight average molecular weight of the ethylene-vinyl acetate copolymer contained in the intermediate release layer is not particularly limited. For example, the weight average molecular weight may be 5000 or more, in order to improve the film-forming property of the composition (VII) described later.

[0213] In one embodiment, the weight average molecular weight of the ethylene-vinyl acetate copolymer contained in the intermediate release layer may be, for example, any one of 5000 to 200000, 5000 to 180000, 5000 to 160000, 5000 to 100000, and 5000 to 60000. However, these are only examples of the weight average molecular weight.

[0214] The intermediate release layer contains ethylene-vinyl acetate copolymer (EVA), which improves the embedding property of the bumps in the first protective film-forming film when the first protective film-forming sheet is attached to the bump-forming surface of the semiconductor wafer. This enables high-speed attachment of the first protective film-forming sheet to the bump-forming surface of the semiconductor wafer. In this specification, the property that enables high-speed attachment of the first protective film-forming sheet is sometimes referred to as "high-speed attachment property." Furthermore, since the intermediate release layer contains EVA, the buffer layer strongly presses the first protective film-forming film when the first protective film-forming sheet is attached to the bump-forming surface of the semiconductor wafer. This makes it possible to make the tops of the bumps protrude from the first protective film-forming film and suppress the first protective film-forming film from remaining on the tops of the bumps even when the first protective film-forming sheet is attached at high speed. In this specification, the property of the first protective film-forming film in the first protective film-forming sheet being suppressed from remaining on the tops of the bumps and easily causing the tops of the bumps to protrude is sometimes referred to as "penetrability". Since EVA has the property of softening moderately when heated, these effects, i.e., the effect that the first protective film-forming sheet has high-speed application ability and the first protective film-forming film has penetrability, are particularly pronounced when the first protective film-forming sheet is applied while being heated.

[0215] The first protective film-forming sheet of this embodiment has an intermediate release layer containing ethylene-vinyl acetate copolymer (EVA), and therefore exhibits the above-mentioned excellent effects (effects of improving the peelability, high-speed application property, and penetrability of the first protective film-forming film of the laminate of the first substrate, buffer layer, and intermediate release layer) regardless of the type of first protective film-forming film.

[0216] The intermediate release layer containing ethylene-vinyl acetate copolymer (EVA) may contain only ethylene-vinyl acetate copolymer (in other words, it may be a layer made of ethylene-vinyl acetate copolymer), or it may contain ethylene-vinyl acetate copolymer and other components.

[0217] The intermediate release layer is in the form of a sheet or film.

[0218] The intermediate release layer may be only one layer (single layer) or may be two or more layers. If it is 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.

[0219] The thickness of the intermediate release layer is preferably from 5 to 30 μm, more preferably from 6 to 25 μm, and particularly preferably from 7 to 20 μm. Here, "the thickness of the intermediate peeling layer" means the thickness of the entire intermediate peeling layer; for example, the thickness of an intermediate peeling layer consisting of multiple layers means the total thickness of all layers that make up the intermediate peeling layer.

[0220] <<Composition for forming intermediate release layer>> The intermediate peeling layer can be formed using a composition for forming an intermediate peeling layer containing its constituent materials. For example, the composition for forming an intermediate peeling layer is applied to the surface on which the intermediate peeling layer is to be formed, and dried as necessary to form the intermediate peeling layer. A more specific method for forming the intermediate peeling layer will be described in detail later, together with the method for forming other layers. The ratio of the contents of the components that do not vaporize at room temperature in the composition for forming an intermediate peeling layer is usually the same as the ratio of the contents of the components of the intermediate peeling layer.

[0221] In the intermediate release layer, the ratio of the total content of one or more components contained in the intermediate release layer, which will be described later, to the total mass of the intermediate release layer does not exceed 100 mass %. Similarly, in the composition for forming an intermediate release layer, the ratio of the total content of one or more of the components contained in the composition for forming an intermediate release layer, as described below, to the total mass of the composition for forming an intermediate release layer does not exceed 100 mass%.

[0222] The composition for forming the intermediate release layer can be applied in the same manner as in the case of the composition for forming the first protective film described above. The drying conditions of the intermediate release layer forming composition are not particularly limited. However, when the intermediate release layer forming composition contains a solvent described later, it is preferable to heat-dry it. And, the intermediate release layer forming composition containing the solvent is preferably heat-dried under conditions of, for example, 70 to 130°C for 10 seconds to 5 minutes.

[0223] <Composition for forming intermediate release layer (VII)> A preferred example of a composition for forming an intermediate release layer is composition (VII) for forming an intermediate release layer containing ethylene-vinyl acetate copolymer (EVA) (sometimes referred to simply as "composition (VII)" in this specification). The composition (VII) may contain an ethylene-vinyl acetate copolymer and other components.

[0224] The ethylene-vinyl acetate copolymer is preferably the main component of the intermediate release layer, which improves the peelability of the laminate of the first base material, the buffer layer, and the intermediate release layer in the first protective film-forming sheet, the high-speed application property of the first protective film-forming sheet, and the penetrability of the first protective film-forming film. In particular, in the intermediate release layer, the ratio of the ethylene-vinyl acetate copolymer content to the total mass of the intermediate release layer ([ethylene-vinyl acetate copolymer content of intermediate release layer (parts by mass)] / [total mass of intermediate release layer (parts by mass)]×100) is preferably 80% by mass or more, more preferably 90% by mass or more, and may be, for example, any one of 95% by mass or more, 97% by mass or more, and 99% by mass or more. When the ratio is equal to or more than the lower limit, the releasability, high-speed application property, and penetration property are further improved. On the other hand, the proportion is 100% by mass or less.

[0225] [Other ingredients] The other components contained in the composition (VII) and the intermediate release layer are not particularly limited and can be appropriately selected depending on the purpose.

[0226] The other components contained in composition (VII) and the intermediate release 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.

[0227] Examples of the other components contained in the composition (VII) and the intermediate release layer include non-polar resins such as ethylene-based polymers. The ethylene-based polymer is a polymer having at least a structural unit derived from ethylene, and may be a homopolymer of ethylene or a copolymer of ethylene and another monomer.

[0228] Examples of the ethylene homopolymer (i.e., polyethylene) include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metallocene-catalyzed linear low density polyethylene (mLLDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE).

[0229] The non-polar resin such as the ethylene polymer may be an oil component such as paraffin oil or paraffin wax.

[0230] The other components contained in the composition (VII) include a solvent. The composition (VII) containing a solvent has excellent handleability.

[0231] Examples of the solvent contained in composition (VII) 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 solvent contained in the composition (VII) may be only one type, or may be two or more types. When two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[0232] The content of the other components in the composition (VII) and the intermediate release layer can be appropriately adjusted depending on the type of the other components.

[0233] When the other component is a component other than the solvent, in the intermediate release layer, the ratio of the content of the other component (component other than the solvent) to the total mass of the intermediate release layer ([content of the other components other than the solvent in the intermediate release layer (parts by mass)] / [total mass of the intermediate release layer (parts by mass)]×100) is preferably 20% by mass or less, more preferably 10% by mass or less, and may be, for example, any of 5% by mass or less, 3% by mass or less, and 1% by mass or less. When the ratio is less than the upper limit, the releasability of the laminate of the first substrate, buffer layer, and intermediate release layer in the first protective film-forming sheet, the high-speed application ability of the first protective film-forming sheet, and the penetrability of the first protective film-forming film are further improved. On the other hand, when the other components are components other than the solvent, the ratio is 0% by mass or more.

[0234] When the other component is a solvent, in composition (VII), the ratio of the content of the other component (solvent) to the total mass of composition (VII) ([content of solvent in composition (VII) (parts by mass)] / [total mass (parts by mass) of composition (VII)]×100) is preferably 5 to 50 mass%, and may be, for example, any one of 5 to 35 mass% and 5 to 20 mass%. When the ratio is equal to or more than the lower limit, the handleability of composition (VII) is further improved. When the ratio is equal to or less than the upper limit, the first protective film-forming film can be formed more efficiently.

[0235] An example of a preferred intermediate release layer in terms of enhancing the intended effect of the present invention (the effect of improving the peelability, high-speed application property, and penetrability of the first protective film-forming film of the laminate of the first substrate, the buffer layer, and the intermediate release layer) is one in which the peel force between the intermediate release layer and the first protective film-forming film in the test piece is 1000 mN / 25 mm or less, contains an ethylene-vinyl acetate copolymer, and in the intermediate release layer, the ratio of the content of the ethylene-vinyl acetate copolymer to the total mass of the intermediate release layer is 80 mass% or more, preferably 90 mass% or more, in the ethylene-vinyl acetate copolymer, the ratio of the amount of structural units derived from vinyl acetate to the total amount of structural units is 40 mass% or less, and the weight average molecular weight of the ethylene-vinyl acetate copolymer is 200,000 or less.

[0236] <<Method of manufacturing the composition for forming the intermediate release layer>> The composition for forming the intermediate release layer, such as composition (VII), can be obtained by blending the respective components for constituting the composition. The composition for forming the intermediate release layer can be produced, for example, by the same method as the composition for forming the thermosetting first protective film described above, except that the types of ingredients used are different.

[0237] ◎Buffer layer The buffer layer has a buffering effect against a force applied to the buffer layer and layers adjacent thereto. Here, the "layers adjacent thereto" include the intermediate release layer, the first protective film-forming film, and the first protective film.

[0238] The material of the buffer layer is not particularly limited, but is preferably a resin.

[0239] A preferred example of the buffer layer is one formed using a buffer layer-forming composition containing urethane (meth)acrylate or the like.

[0240] The buffer layer may be only one layer (single layer), or may be two or more layers. If it is 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.

[0241] The thickness of the buffer layer is preferably from 150 to 1000 μm, more preferably from 150 to 800 μm, further preferably from 200 to 600 μm, and particularly preferably from 250 to 500 μm. Here, the "thickness of the buffer layer" means the thickness of the entire buffer layer. 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.

[0242] <<Composition for forming buffer layer>> The buffer layer can be formed using a buffer layer forming composition containing a material for forming the buffer layer. For example, the buffer layer can be formed by applying the buffer layer forming composition to the surface on which the buffer layer is to be formed, and drying it as necessary. When the buffer layer forming composition has energy ray curing properties as described below, it is preferable to further cure the buffer layer forming composition after application with energy ray. A more specific method for forming the buffer layer will be described in detail later, together with the methods for forming other layers.

[0243] In the buffer layer forming composition, the ratio of the total content of one or more components contained in the buffer layer forming composition, which will be described later, to the total mass of the buffer layer forming composition does not exceed 100 mass %.

[0244] The composition for forming the buffer layer can be applied in the same manner as in the case of the composition for forming the first protective film described above. The drying conditions for the composition for forming the buffer layer are not particularly limited, and may be the same as the drying conditions for the composition for forming the intermediate release layer described above, for example.

[0245] When the energy ray-curable buffer layer-forming composition is cured with energy rays, the illuminance of the energy rays is 100 to 350 mW / cm 2 The amount of energy rays is preferably 200 to 1400 mJ / cm 2 The energy ray curing of the energy ray curable buffer layer forming composition may be carried out in one step, or may be carried out in two or more separate steps (via semi-curing). When the energy ray curing is carried out in multiple separate steps, the amount of energy ray in each step is preferably 200 to 1400 mJ / cm. 2 It is preferable that the total amount of light for all times is 200 to 1400 mJ / cm 2 It is preferable that:

[0246] <Buffer layer forming composition (VI)> The composition for forming a buffer layer may, for example, be a composition for forming a buffer layer (VI) (sometimes simply referred to as "composition (VI)" in this specification) containing a urethane (meth)acrylate (X).

[0247] [Urethane (meth)acrylate (X)] The urethane (meth)acrylate (X) contained in the composition (VI) is a compound having at least a (meth)acryloyl group and a urethane bond, and has the property of being polymerized by energy ray irradiation. That is, the composition (VI) has energy ray curing properties. The number of (meth)acryloyl groups in the urethane (meth)acrylate (X) may be any of 1, 2, and 3 or more (that is, the urethane (meth)acrylate (X) may be any of monofunctional, bifunctional, and trifunctional or more), but it is preferable that the urethane (meth)acrylate (X) is a monofunctional urethane (meth)acrylate. The monofunctional urethane (meth)acrylate (X) does not participate in the formation of a three-dimensional network structure in the polymerization structure, so that the three-dimensional network structure is difficult to form in the buffer layer, and in that case, the first protective film forming sheet is easy to follow the bump formation surface of the semiconductor wafer.

[0248] The urethane (meth)acrylate (X) contained in the composition (VI) may be of only one type, or of two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0249] The urethane (meth)acrylate (X) may be, for example, a reaction product of a terminal isocyanate urethane prepolymer, which is a reaction product of a polyol compound (x1) and a polyisocyanate compound (x2), and a compound (x3) having a (meth)acryloyl group. Here, the term "terminal isocyanate urethane prepolymer" is as described above.

[0250] The polyol compound (x1) is not particularly limited as long as it is a compound having two or more hydroxyl groups in one molecule. Examples of the polyol compound (x1) include alkylene diols, polyether polyols, polyester polyols, polycarbonate polyols, etc. Among these, the polyol compound (x1) is preferably a polyether polyol.

[0251] The polyol compound (x1) may be any of a difunctional diol, a trifunctional triol, and a tetrafunctional or higher polyol. From the viewpoints of availability, versatility, reactivity, and the like, a difunctional diol is preferable, and a polyether diol is more preferable. Examples of the polyether diol include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

[0252] The polyester polyol is obtained by polycondensation of a polyol component and a polybasic acid component. Examples of the polyol component include various alkanediols such as ethylene glycol, diethylene glycol, and butanediol (preferably alkanediols having 2 to 10 carbon atoms), and various glycols. The polybasic acid component may be, for example, a component known as a polybasic acid component of a general polyester. More specifically, the polybasic acid component may be, for example, an aliphatic dibasic acid having 4 to 20 carbon atoms, such as adipic acid or sebacic acid; an aromatic dibasic acid, such as terephthalic acid; an aromatic polybasic acid, such as trimellitic acid; anhydrides of these dibasic acids or polybasic acids; derivatives of these dibasic acids or polybasic acids, dimer acids, and hydrogenated dimer acids.

[0253] The polycarbonate type polyol is not particularly limited, and examples of the polycarbonate type polyol include reaction products of glycols and alkylene carbonates.

[0254] Examples of the polyisocyanate compound (x2) include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates.

[0255] The compound (x3) having a (meth)acryloyl group may be a (meth)acrylate having a hydroxyl group, and may be the same as the hydroxyl group-containing (meth)acrylic acid ester previously listed as a component constituting the acrylic resin as the polymer component (A) contained in the composition (III). Among these, the (meth)acrylate having a hydroxyl group is preferably a hydroxyalkyl (meth)acrylate.

[0256] The weight average molecular weight of the urethane (meth)acrylate (X) is preferably 1000 to 100000, more preferably 3000 to 80000, and further preferably 5000 to 65000. When the weight average molecular weight is 1000 or more, the polymer of the urethane (meth)acrylate (X) and the polymerizable monomer (Z) described later imparts an appropriate hardness to the buffer layer.

[0257] In composition (VI), the ratio of the content of the urethane (meth)acrylate (X) to the total content of components other than the solvent ([content of the urethane (meth)acrylate (X) in composition (VI) (parts by mass)] / [total content of components other than the solvent in composition (VI) (parts by mass)]×100) is preferably 10 to 70% by mass, more preferably 20 to 70% by mass, even more preferably 25 to 60% by mass, and particularly preferably 30 to 50% by mass. When the ratio is within such a range, the effect obtained by providing the buffer layer in the first protective film-forming sheet is enhanced without compromising other effects.

[0258] [Other ingredients] The composition (VI) may contain a urethane (meth)acrylate (X) and other components that do not fall under the category of the urethane (meth)acrylate (X). Examples of the other components in the composition (VI) include a thiol group-containing compound (Y) and a polymerizable monomer (Z).

[0259] The other components contained in the composition (VI) may be one type only, or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily. The composition (VI) may contain only one of the thiol group-containing compound (Y) and the polymerizable monomer (Z), but it is preferable that the composition (VI) contains both the thiol group-containing compound (Y) and the polymerizable monomer (Z).

[0260] (Thiol group-containing compound (Y)) The thiol group-containing compound (Y) is not particularly limited as long as it is a compound having one or more thiol groups (-SH) in one molecule.

[0261] Examples of the thiol group-containing compound (Y) include nonyl mercaptan, 1-dodecanethiol, 1,2-ethanedithiol, 1,3-propanedithiol, triazine thiol, triazine dithiol, triazine trithiol, 1,2,3-propane trithiol, tetraethylene glycol bis(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), Examples of the mercaptopropyl ether include pentaerythritol tetrakisthioglucarate, dipentaerythritol hexakis(3-mercaptopropionate), tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, 1,4-bis(3-mercaptobutyryloxy)butane, pentaerythritol tetrakis(3-mercaptobutyrate), and 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione.

[0262] The thiol group-containing compound (Y) is preferably a polyfunctional thiol group-containing compound (a compound having two or more thiol groups in one molecule), and more preferably a tetrafunctional thiol group-containing compound (a compound having four thiol groups in one molecule).

[0263] The thiol group-containing compound (Y) contained in the composition (VI) may be one type or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0264] In the composition (VI), the content of the thiol group-containing compound (Y) relative to 100 parts by mass of the total content of the urethane (meth)acrylate (X) and the polymerizable monomer (Z) ([content (parts by mass) of the thiol group-containing compound (Y) in the composition (VI)] / [total content (parts by mass) of the urethane (meth)acrylate (X) and the polymerizable monomer (Z) in the composition (VI)]×100) is preferably 1 to 4.9 parts by mass, and more preferably 1.5 to 4.8 parts by mass.

[0265] (Polymerizable monomer (Z)) From the viewpoint of improving the film-forming property of the buffer layer, the composition (VI) preferably contains a polymerizable monomer (Z). The polymerizable monomer (Z) is a polymerizable compound other than the urethane (meth)acrylate (X) and is a compound that can be polymerized by irradiation with energy rays. However, the polymerizable monomer (Z) does not include a resin component. Here, the "resin component" refers to an oligomer or polymer having a repeating unit in its structure and a compound having a weight average molecular weight of 1000 or more.

[0266] The polymerizable monomer (Z) is preferably a compound having one or more (meth)acryloyl groups. Examples of such polymerizable monomers (Z) include (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure having 1 to 18 carbon atoms; (meth)acrylic acid esters having functional groups such as hydroxyl groups, amide groups, amino groups, or epoxy groups; (meth)acrylic acid esters having alicyclic structures such as (meth)acrylic acid cycloalkyl esters; (meth)acrylic acid esters having aromatic structures; (meth)acrylic acid esters having heterocyclic structures; and vinyl compounds other than these.

[0267] Among the (meth)acrylic acid esters having a functional group, examples of the (meth)acrylic acid esters having a hydroxyl group include the same hydroxyl group-containing (meth)acrylic acid esters as those previously listed as constituting the acrylic resin as the polymer component (A) which is a component contained in the composition (III). Examples of the (meth)acrylic acid ester having an alicyclic structure include isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxy (meth)acrylate, cyclohexyl (meth)acrylate, 1-adamantyl (meth)acrylate, and 2-adamantyl (meth)acrylate. Examples of the (meth)acrylic acid ester having an aromatic structure include phenylhydroxypropyl (meth)acrylate, benzyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate. Examples of the (meth)acrylic acid ester having a heterocyclic structure include tetrahydrofurfuryl (meth)acrylate, 2-morpholinoethyl (meth)acrylate, and the like.

[0268] The polymerizable monomer (Z) contained in the composition (VI) may be one kind or two or more kinds. When there are two or more kinds, the combination and ratio thereof can be selected arbitrarily.

[0269] The composition (VI) preferably contains, as the polymerizable monomer (Z), at least a (meth)acrylic acid ester having an alicyclic structure, more preferably both a (meth)acrylic acid ester having an alicyclic structure and a (meth)acrylic acid ester having a functional group, and even more preferably both isobornyl (meth)acrylate and a hydroxyalkyl (meth)acrylate.

[0270] In the composition (VI), the ratio of the content of the polymerizable monomer (Z) to the total content of the components other than the solvent ([content of the polymerizable monomer (Z) in the composition (VI) (parts by mass)] / [total content of the components other than the solvent in the composition (VI) (parts by mass)]×100) is preferably 20 to 80% by mass, more preferably 30 to 80% by mass, even more preferably 40 to 75% by mass, and particularly preferably 50 to 70% by mass. When the content is within such a range, the mobility of the portion having a structure in which the polymerizable monomer (Z) is polymerized in the buffer layer becomes higher, so that the buffer layer tends to become more flexible, and the first protective film-forming sheet becomes easier to follow the bump formation surface of the semiconductor wafer.

[0271] In composition (VI), the ratio of the content of the (meth)acrylic acid ester having an alicyclic structure to the total content of the polymerizable monomer (Z) ([content (parts by mass) of the (meth)acrylic acid ester having an alicyclic structure in composition (VI)] / [total content (parts by mass) of the polymerizable monomer (Z) in composition (VI)]×100) is preferably 52 to 87% by mass, more preferably 55 to 85% by mass, and even more preferably 60 to 80% by mass. When the content is within this range, the first protective film-forming sheet can more easily conform to the bump formation surface of the semiconductor wafer.

[0272] The mass ratio of [content (parts by mass) of urethane (meth)acrylate (X) in composition (VI)] / [content (parts by mass) of polymerizable monomer (Z) in composition (VI)] is preferably 20 / 80 to 60 / 40, more preferably 30 / 70 to 50 / 50, and even more preferably 35 / 65 to 45 / 55. When the mass ratio is in such a range, the first protective film-forming sheet can more easily conform to the bump formation surface of the semiconductor wafer.

[0273] (Photopolymerization initiator) The composition (VI) preferably further contains a photopolymerization initiator. The composition (VI) containing a photopolymerization initiator is more easily cured by irradiation with energy rays.

[0274] Examples of the photopolymerization initiator contained in the composition (VI) include acetophenone, 2,2-diethoxybenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, Michler's ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl diphenylsulfide, tetramethylthiuram monosulfide, benzyl dimethyl ketal, dibenzyl, diacetyl, 1-chloroanthraquinone, 2-chloroanthraquinone, 2-ethylanthraquinone, and 2,2-dimethoxy-1,2-diphenylethane. low molecular weight polymerization initiators such as 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, diethylthioxanthone, isopropylthioxanthone, and 2,4,6-trimethylbenzoyldiphenyl-phosphine oxide; and oligomerized polymerization initiators such as oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone}.

[0275] The photopolymerization initiator contained in the composition (VI) may be only one type, or may be two or more types. When two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[0276] In the composition (VI), the content of the photopolymerization initiator relative to the total content of the urethane (meth)acrylate (X) and the polymerizable monomer (Z) ([content of the photopolymerization initiator in the composition (VI) (parts by mass)] / [total content of the urethane (meth)acrylate (X) and the polymerizable monomer (Z) in the composition (parts by mass)]×100) is preferably 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.3 to 5 parts by mass, relative to 100 parts by mass of the total content of the urethane (meth)acrylate (X) and the polymerizable monomer (Z).

[0277] (Other additives) Composition (VI) may contain other additives other than those described above, within the scope of not impairing the effects of the present invention. Examples of the other additives include crosslinking agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, pigments, and dyes.

[0278] When the composition (VI) contains the other additives, the content of the other additives in the composition (VI) relative to 100 parts by mass of the total content of the urethane (meth)acrylate (X) and the polymerizable monomer (Z) ([content (parts by mass) of the other additives in the composition (VI)] / [total content (parts by mass) of the urethane (meth)acrylate (X) and the polymerizable monomer (Z) in the composition (VI)]×100) is preferably 0.01 to 6 parts by mass, and more preferably 0.1 to 3 parts by mass.

[0279] (Other resin components) The composition (VI) may contain other resin components that do not fall under the category of the urethane (meth)acrylate (X) within the range that does not impair the effects of the present invention.

[0280] <Modifications of the buffer layer> So far, the buffer layer has been described as being formed using a buffer layer-forming composition containing the urethane (meth)acrylate (X). However, in this embodiment, the buffer layer may be formed using a buffer layer-forming composition containing another resin component such as an olefin resin, instead of the urethane (meth)acrylate (X).

[0281] For example, an example of a preferred buffer layer in terms of improving the high-speed application property of the first protective film-forming sheet and the penetrability of the first protective film-forming film is a buffer layer obtained using a buffer layer-forming composition (composition (VI)) containing a urethane (meth)acrylate (X), a thiol group-containing compound (Y), a polymerizable monomer (Z), a photopolymerization initiator, and a crosslinking agent, in which the ratio of the total content of the urethane (meth)acrylate (X), the thiol group-containing compound (Y), the polymerizable monomer (Z), the photopolymerization initiator, and the crosslinking agent to the total content of components other than the solvent in the buffer layer-forming composition is 85 mass% or more, preferably 90 mass% or more, and more preferably 95 mass% or more. From the above viewpoints, a more preferable example of the buffer layer is a buffer layer obtained by using a buffer layer-forming composition (composition (VI)) containing a urethane (meth)acrylate (X), a thiol group-containing compound (Y), a polymerizable monomer (Z), a photopolymerization initiator, and a crosslinking agent, in which the urethane (meth)acrylate (X) is a reaction product of a terminal isocyanate urethane prepolymer, which is a reaction product of a polyol compound (x1) and a polyisocyanate compound (x2), and a compound (x3) having a (meth)acryloyl group, and the thiol group-containing compound (Y) is one molecule thereof. and the polymerizable monomer (Z) is a (meth)acrylic acid ester having an alicyclic structure and a (meth)acrylic acid ester having a functional group, and in the buffer layer forming composition, the ratio of the total content of the urethane (meth)acrylate (X), the thiol group-containing compound (Y), the polymerizable monomer (Z), the photopolymerization initiator and the crosslinking agent to the total content of components other than the solvent is 85 mass % or more, preferably 90 mass % or more, and more preferably 95 mass % or more. These buffer layers are preferably obtained by curing the buffer layer-forming composition with energy rays. The thickness of these buffer layers is preferably 10 to 70 times, and more preferably 30 to 50 times, the thickness of the intermediate release layer.

[0282] <<Method of manufacturing the composition for forming the buffer layer>> The buffer layer-forming composition such as composition (VI) can be obtained by blending the respective components constituting the buffer layer. The composition for forming the buffer layer can be produced in the same manner as the composition for forming the thermosetting first protective film described above, except that the types of ingredients used are different.

[0283] ◎First base material The first base material 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 by 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; vinyl chloride-based resins (copolymers obtained by using vinyl chloride as a monomer) such as polyvinyl chloride and vinyl chloride copolymer. obtained resin); polystyrene; polycycloolefin; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and wholly aromatic polyesters in which all constituent 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. The resin may also be a polymer alloy such as a mixture of the polyester and another resin. The polymer alloy of the polyester and another resin is preferably one in which the amount of the resin other than the polyester is relatively small. 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.

[0284] The resin constituting the first base material may be only one type, or may be two or more types. When two or more types are used, the combination and ratio thereof can be selected arbitrarily.

[0285] The first base material may be only one layer (single layer), or may be two or more layers. If it is 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.

[0286] The thickness of the first substrate is preferably from 5 to 1000 μm, more preferably from 10 to 500 μm, further preferably from 15 to 300 μm, and particularly preferably from 20 to 150 μm. Here, "the thickness of the first substrate" means the thickness of the entire first substrate. For example, the thickness of a first substrate consisting of multiple layers means the total thickness of all layers constituting the first substrate.

[0287] The first base material is preferably one having a high thickness accuracy, i.e., one having reduced thickness variation regardless of the location. Among the above-mentioned constituent materials, examples of materials that can be used to constitute the first base material having such a high thickness accuracy include polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, and ethylene-vinyl acetate copolymer.

[0288] In addition to the main constituent materials such as the resin, the first substrate may contain various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, and softeners (plasticizers).

[0289] The first substrate may be transparent or opaque, may be colored according to the purpose, and may have other layers vapor-deposited thereon. When the first protective film-forming film is energy ray-curable, the first base material is preferably one that transmits energy rays.

[0290] The first substrate can be produced by a known method. For example, a first substrate containing a resin can be produced by molding a resin composition containing the resin.

[0291] ◎Example of the sheet for forming the first protective film A preferred example of the first protective film-forming sheet of the present embodiment is a first protective film-forming sheet for forming a first protective film at least on a surface of a semiconductor wafer having bumps, The first protective film-forming sheet is configured by laminating a first base material, a buffer layer, an intermediate release layer, and a first protective film-forming film in this order in a thickness direction, a test piece of the first protective film-forming sheet having a width of 25 mm was used, the intermediate release layer was peeled off from the first protective film-forming film, and a peel test was performed in which the intermediate release layer was peeled off from the first protective film-forming film in its length direction at a peel speed of 100 mm / min with the angle between the surface of the first protective film-forming film to which the intermediate release layer was attached and the surface of the intermediate release layer to which the first protective film-forming film was attached being set at 180°; the peel force between the intermediate release layer and the first protective film-forming film was 1000 mN / 25 mm or less, the intermediate release layer contains an ethylene-vinyl acetate copolymer, and the content of the ethylene-vinyl acetate copolymer in the intermediate release layer is 80% by mass or more relative to the total mass of the intermediate release layer; The first protective film-forming film is a thermosetting first protective film-forming film containing a polymer component (A), a thermosetting component (B), a curing accelerator (C), a filler (D), and an additive (I), and in the first protective film-forming film, the ratio of the total content of the polymer component (A), the thermosetting component (B), the curing accelerator (C), the filler (D), and the additive (I) to the total mass of the first protective film-forming film is 85 mass% or more, An example of the first protective film-forming sheet is a buffer layer obtained using a buffer layer-forming composition containing a urethane (meth)acrylate (X), a thiol group-containing compound (Y), a polymerizable monomer (Z), a photopolymerization initiator, and a crosslinking agent, and in the buffer layer-forming composition, the ratio of the total content of the urethane (meth)acrylate (X), the thiol group-containing compound (Y), the polymerizable monomer (Z), the photopolymerization initiator, and the crosslinking agent to the total content of components other than a solvent is 85 mass% or more. In such a sheet for forming a first protective film, the thickness of the first protective film-forming film is preferably 2 to 7 times the thickness of the intermediate release layer, and the thickness of the buffer layer is preferably 10 to 70 times the thickness of the intermediate release layer.

[0292] Another preferred example of the first protective film-forming sheet of the present embodiment is a first protective film-forming sheet for forming a first protective film at least on a surface of a semiconductor wafer having bumps, The first protective film-forming sheet is configured by laminating a first base material, a buffer layer, an intermediate release layer, and a first protective film-forming film in this order in a thickness direction, a test piece of the first protective film-forming sheet having a width of 25 mm was used, the intermediate release layer was peeled off from the first protective film-forming film, and a peel test was performed in which the intermediate release layer was peeled off from the first protective film-forming film in its length direction at a peel speed of 100 mm / min with the angle between the surface of the first protective film-forming film to which the intermediate release layer was attached and the surface of the intermediate release layer to which the first protective film-forming film was attached being set at 180°; the peel force between the intermediate release layer and the first protective film-forming film was 1000 mN / 25 mm or less, the intermediate release layer contains an ethylene-vinyl acetate copolymer, the content of the ethylene-vinyl acetate copolymer in the intermediate release layer is 80% by mass or more relative to the total mass of the intermediate release layer, the content of structural units derived from vinyl acetate in the ethylene-vinyl acetate copolymer is 40% by mass or less relative to the total amount of structural units, and the weight average molecular weight of the ethylene-vinyl acetate copolymer is 200,000 or less; The first protective film-forming film is a thermosetting first protective film-forming film containing a polymer component (A), a thermosetting component (B), a curing accelerator (C), a filler (D), and an additive (I), the polymer component (A) is polyvinyl acetal, the thermosetting component (B) is an epoxy resin (B1) and a thermosetting agent (B2), and the additive (I) is one or more selected from the group consisting of a rheology control agent, a surfactant, and a silicone oil, and in the first protective film-forming film, the ratio of the total content of the polymer component (A), the thermosetting component (B), the curing accelerator (C), the filler (D), and the additive (I) to the total mass of the first protective film-forming film is 85 mass% or more, The buffer layer is a buffer layer obtained by using a composition for forming a buffer layer, the composition containing a urethane (meth)acrylate (X), a thiol group-containing compound (Y), a polymerizable monomer (Z), a photopolymerization initiator, and a crosslinking agent, the urethane (meth)acrylate (X) being a reaction product of a terminal isocyanate urethane prepolymer, which is a reaction product of a polyol compound (x1) and a polyisocyanate compound (x2), and a compound (x3) having a (meth)acryloyl group, the thiol group-containing compound (Y) having two isocyanate groups in one molecule, and a first protective film-forming sheet, in which the polymerizable monomer (Z) is a (meth)acrylic acid ester having an alicyclic structure and a (meth)acrylic acid ester having a functional group, and in the buffer layer-forming composition, the ratio of the total content of the urethane (meth)acrylate (X), the thiol group-containing compound (Y), the polymerizable monomer (Z), the photopolymerization initiator, and the crosslinking agent to the total content of components other than the solvent is 85 mass% or more. In such a sheet for forming a first protective film, the thickness of the first protective film-forming film is preferably 2 to 7 times the thickness of the intermediate release layer, and the thickness of the buffer layer is preferably 10 to 70 times the thickness of the intermediate release layer.

[0293] ◇ Manufacturing method of the sheet for forming the first protective film The first protective film-forming sheet can be produced by laminating the above-mentioned layers in order so that they are in a corresponding positional relationship. The method of forming each layer is as described above.

[0294] For example, the first protective film-forming sheet can be produced by the method described below. That is, a buffer layer is formed on the first substrate by applying a buffer layer-forming composition (for example, the composition (VI)) onto one surface of the first substrate and drying as necessary. When the buffer layer-forming composition is energy ray curable, the applied buffer layer-forming composition is further cured with energy rays. This results in a first laminated sheet in which the first substrate and the buffer layer are laminated together. A release film may be further provided on the exposed surface of the buffer layer in the first laminated sheet (the surface opposite to the first substrate side) as necessary. Separately, a composition for forming an intermediate release layer (for example, the composition (VII)) is applied onto a release film, and dried as necessary to form an intermediate release layer on the release film. In this case, it is preferable that the composition for forming an intermediate release layer is applied onto the release-treated surface of the release film. Separately, a first protective film-forming composition (e.g., composition (III), composition (IV) or composition (V)) is applied onto a release film and dried as necessary to form a first protective film-forming film on the release film. In this case, it is preferable that the first protective film-forming composition is applied onto the release-treated surface of the release film.

[0295] Next, the exposed surface of the buffer layer (the surface opposite to the first substrate side) of the first laminate sheet is bonded to the exposed surface of the intermediate release layer (the surface opposite to the release film side), thereby obtaining a second laminate sheet configured by laminating the first substrate, buffer layer, intermediate release layer, and release film in this order in the thickness direction.

[0296] Next, in the second laminated sheet, the release film is removed, and the exposed surface of the intermediate release layer (the surface opposite to the buffer layer side) resulting from this is bonded to the exposed surface of the first protective film-forming film (the surface opposite to the release film side). This results in a first protective film-forming sheet configured by laminating the first base material, the buffer layer, the intermediate release layer, the first protective film-forming film, and the release film in this order in the thickness direction. The release film provided on the first protective film-forming film in the first protective film-forming sheet may be removed at any stage from after the production of the first protective film-forming sheet to after its use.

[0297] A first protective film-forming sheet having layers other than the above-mentioned layers can be produced by appropriately adding either or both of the formation process and lamination process of the other layers in the above-mentioned production method so that the lamination position of the other layers is appropriate.

[0298] ◇Method of manufacturing a semiconductor device (method of using the sheet for forming a first protective film) As described above, the first protective film-forming sheet of this embodiment is used, and the first protective film-forming film therein is attached to the bump-forming surface of the semiconductor wafer. At this time, the top of the bump is made to protrude from the first protective film-forming film, and it is possible to suppress the first protective film-forming film from remaining on the top of the bump. Furthermore, when the intermediate release layer contains an ethylene-vinyl acetate copolymer, the first protective film-forming sheet of this embodiment can be attached to the bump-forming surface of the semiconductor wafer at high speed. Furthermore, even when the first protective film-forming sheet is attached at high speed, it is possible to suppress the first protective film-forming film from remaining on the top of the bump. Next, by curing the first protective film-forming film as necessary, a semiconductor wafer with a first protective film can be manufactured, which includes a semiconductor wafer and a first protective film provided on the bump-forming surface of the semiconductor wafer. In this case, before the first protective film is formed, it is necessary to peel off the laminate of the first base material, the buffer layer, and the intermediate release layer from the first protective film-forming film on the bump formation surface, and the laminate has good peelability. Next, by dividing the semiconductor wafer with the first protective film, a semiconductor chip with the first protective film, which includes a semiconductor chip and a first protective film provided on the bump-forming surface of the semiconductor chip, can be manufactured. At this time, since the first protective film-forming film is prevented from remaining on the upper parts of the bumps of the semiconductor wafer with the first protective film, the adhesion of the first protective film is also prevented on the upper parts of the bumps of the obtained semiconductor chip with the first protective film. Furthermore, the semiconductor chip with the first protective film can be flip-chip connected to a substrate at the bumps therein to manufacture a semiconductor device. At this time, since the adhesion of the first protective film to the top of the bumps of the semiconductor chip with the first protective film is suppressed, the electrical connection between the semiconductor chip and the substrate is not impeded. In other words, the sheet for forming a first protective film of this embodiment is suitable for manufacturing semiconductor devices. Hereinafter, a method for manufacturing a semiconductor device using the first protective film-forming sheet will be described.

[0299] A manufacturing method of a semiconductor device according to one embodiment of the present invention is a manufacturing method of a semiconductor device using a first protective film-forming sheet according to one embodiment of the present invention described above, and the manufacturing method includes a bonding step of bonding the first protective film-forming film in the first protective film-forming sheet to a surface of a semiconductor wafer having bumps (bump-forming surface) and causing tops of the bumps to protrude from the first protective film-forming film, thereby providing the first protective film-forming sheet on the semiconductor wafer, and after the bonding step, peeling the intermediate release layer in the first protective film-forming sheet from the first protective film-forming film to remove layers of the first protective film-forming sheet other than the first protective film-forming film from the first protective film-forming film, and further, when the first protective film-forming film is curable, curing the first protective film-forming film to form a semiconductor wafer. The method includes a first protective film forming step of forming a first protective film, and when the first protective film-forming film is non-curable, treating the first protective film after removing layers other than the first protective film as the first protective film, thereby forming the first protective film on the surface having the bumps (bump-forming surface); a dividing step of producing semiconductor chips by dividing the semiconductor wafer after the first protective film forming step; a cutting step of cutting the first protective film after the first protective film forming step; and a mounting step of flip-chip connecting the semiconductor chip with the first protective film, in which the tops of the bumps protrude from the first protective film, to a substrate at the tops of the bumps.

[0300] Among the methods for manufacturing a semiconductor device of this embodiment, a manufacturing method in which the first protective film-forming film is curable (sometimes referred to in this specification as "manufacturing method (1)") includes a bonding step of bonding the first protective film-forming film in the first protective film-forming sheet to a surface of a semiconductor wafer having bumps (bump-forming surface) and causing the tops of the bumps to protrude from the first protective film-forming film, thereby providing the first protective film-forming sheet on the semiconductor wafer; and after the bonding step, peeling the intermediate release layer in the first protective film-forming sheet from the first protective film-forming film, thereby removing layers of the first protective film-forming sheet other than the first protective film-forming film from the first protective film-forming film, and The method further includes a first protective film forming step of forming the first protective film on the surface having the bumps (bump forming surface) by hardening the first protective film forming film to form a first protective film; a dividing step of producing semiconductor chips by dividing the semiconductor wafer after the first protective film forming step; a cutting step of cutting the first protective film after the first protective film forming step; and a mounting step of flip-chip connecting the semiconductor chip with the first protective film, which includes the semiconductor chip obtained after the dividing step and the cutting step, and the first protective film provided on the surface having the bumps (bump forming surface) of the semiconductor chip, with the tops of the bumps protruding from the first protective film, to a substrate at the tops of the bumps.

[0301] Among the manufacturing methods of the semiconductor device of this embodiment, a manufacturing method in which the first protective film-forming film is non-curable (sometimes referred to as "manufacturing method (2)" in this specification) includes a bonding step of bonding the first protective film-forming film in the first protective film-forming sheet to a surface of a semiconductor wafer having bumps (bump-forming surface) and causing the tops of the bumps to protrude from the first protective film-forming film, thereby providing the first protective film-forming sheet on the semiconductor wafer; and after the bonding step, peeling the intermediate release layer in the first protective film-forming sheet from the first protective film-forming film, thereby removing layers of the first protective film-forming sheet other than the first protective film-forming film from the first protective film-forming film, and further The method includes a first protective film forming step of forming the first protective film on the surface having the bumps (bump forming surface) by treating the first protective film formed film after removing layers other than the first protective film as a first protective film, a dividing step of producing semiconductor chips by dividing the semiconductor wafer after the first protective film forming step, a cutting step of cutting the first protective film after the first protective film forming step, and a mounting step of flip-chip connecting the semiconductor chip with the first protective film, the semiconductor chip having the bumps and the first protective film provided on the surface of the semiconductor chip having the bumps, obtained after the dividing step and the cutting step, and the tops of the bumps protruding from the first protective film, to a substrate at the tops of the bumps.

[0302] <<Manufacturing method (1)>> The production method (1) will now be described. 2A to 2E are cross-sectional views for illustrating an example of the manufacturing method (1) when the first protective film-forming sheet 1 shown in FIG. 1 is used. In FIG. 2A 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.

[0303] <Attachment process> 2A and 2B, in the attachment step of the manufacturing method (1), the first protective film-forming film 14 in the first protective film-forming sheet 1 is attached to a surface (bump-forming surface) 9a having bumps 91 of the semiconductor wafer 9, and the tops 9101 of the bumps 91 are made to protrude from the first protective film-forming film 14, thereby providing the first protective film-forming sheet 1 on the semiconductor wafer 9. At this time, the first protective film-forming film 14 is prevented from remaining on the upper parts 910 of the bumps 91.

[0304] In the sticking step, for example, first, as shown in FIG. 2A, the first protective film-forming sheet 1 is placed so that the first protective film-forming film 14 therein faces the bump formation surface 9a of the semiconductor wafer 9.

[0305] The height of the bump 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 bump 91 is equal to or greater than the lower limit, the function of the bump 91 can be further improved. When the height of the bump 91 is equal to or less than the upper limit, the effect of suppressing the first protective film-forming film 14 from remaining on the upper portion 910 of the bump 91 is enhanced. In this specification, the "height of a bump" means the height of the bump at the highest point from the bump formation surface.

[0306] 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 first protective film-forming film 14 from remaining on the upper portion 910 of the bump 91 is enhanced. In this specification, the "width of a bump" means the maximum length of a line segment obtained by drawing a straight line between 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-forming surface.

[0307] 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 first protective film-forming film 14 from remaining on the upper portions 910 of 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.

[0308] Next, in the bonding step, the first protective film-forming film 14 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 14a of the first protective film-forming film 14 to be pressed against the surfaces 91a of the bumps 91 and the bump-forming surface 9a of the semiconductor wafer 9, in that order. At this time, by heating the first protective film-forming film 14, the first protective film-forming film 14 softens and spreads between the bumps 91 so as to cover the bumps 91, adheres to the bump-forming surface 9a, and covers the surfaces 91a of the bumps 91, particularly the surfaces 91a in the vicinity of the bump-forming surface 9a, to embed the bases of the bumps 91. As a result of the above, the first protective film-forming film 14 in the first protective film-forming sheet 1 is attached to the bump formation surface 9a of the semiconductor wafer 9, as shown in FIG. 2B.

[0309] As described above, the method of pressing (in other words, attaching) the first protective film forming sheet 1 to the semiconductor wafer 9 can be any known method of pressing and attaching various sheets to an object, such as a method using a roller-type laminator.

[0310] The heating temperature of the first protective film-forming sheet 1 (first protective film-forming film 14) when it is pressed (attached) to the semiconductor wafer 9 may be a temperature at which the curing of the thermosetting first protective film-forming film 14 does not proceed at all or excessively, and may be, for example, 80 to 100°C. However, the heating temperature is more preferably 85 to 95° C. in order to enhance the effect of suppressing the first protective film-forming film 14 from remaining on the upper parts 910 of the bumps 91.

[0311] The pressure when the first protective film-forming sheet 1 (first protective film-forming film 14) is pressure-bonded (attached) to the semiconductor wafer 9 is not particularly limited, and may be, for example, 0.1 to 1.5 MPa. However, in terms of improving the effect of suppressing the first protective film-forming film 14 from remaining on the upper portion 910 of the bump 91, the pressure is more preferably 0.3 to 1 MPa.

[0312] The speed (applying speed) when the first protective film-forming sheet 1 (first protective film-forming film 14) is applied to the semiconductor wafer 9 may be, for example, 3 mm / s or more. When the intermediate release layer 13 in the first protective film-forming sheet 1 contains an ethylene-vinyl acetate copolymer, the first protective film-forming sheet 1 can be applied to the bump-forming surface 9a of the semiconductor wafer 9 at high speed. In this case, the application speed is preferably 4 mm / s or more. That is, when the intermediate release layer 13 contains an ethylene-vinyl acetate copolymer, in the application step, the first protective film-forming film 14 is preferably applied to the bump-forming surface 9a of the semiconductor wafer 9 at an application speed of 4 mm / s or more. By applying the first protective film-forming film 14 at a high speed such as 4 mm / s or more, the above-mentioned effect of suppressing the remaining of the first protective film-forming film 14 on the upper portion 910 of the bump 91 is more significantly exhibited. On the other hand, by setting the sticking speed to 20 mm / s or less, the effect of suppressing the first protective film-forming film 14 from remaining on the upper portion 910 of the bump 91 is more stably achieved.

[0313] As described above, when the first protective film-forming sheet 1 is pressure-bonded (attached) to the semiconductor wafer 9, the first protective film-forming film 14 and the intermediate release layer 13 in the first protective film-forming sheet 1 are pressed through the buffer layer 12 and pressure is applied from the bumps 91. In the initial stage, the first surface 14a of the first protective film-forming film 14 and the first surface 13a of the intermediate release layer 13 are deformed into a concave shape. Then, the first protective film-forming film 14 to which pressure is applied from the bumps 91 in this state is torn. Finally, at the stage where the first surface 14a of the first protective film-forming film 14 is pressure-bonded to the bump-forming surface 9a of the semiconductor wafer 9, the upper portion 910 including the top portion 9101 of the bump 91 penetrates the first protective film-forming film 14 and protrudes. Note that in this final stage, the upper portion 910 of the bump 91 does not usually penetrate the intermediate release layer 13. This is because the first protective film-forming sheet 1 has the buffer layer 12, and is particularly noticeable when the intermediate release layer 13 contains EVA.

[0314] 2B, at the stage where the attachment process is completed, none or almost none of the first protective film-forming film 14 remains on the upper portion 910 including the top portion 9101 of the bump 91, and the remaining first protective film-forming film 14 is suppressed on the upper portion 910 of the bump 91. In this specification, unless otherwise specified, "almost no first protective film-forming film remains on the upper portion of the bump" means that although a small amount of the first protective film-forming film remains on the upper portion of the bump, the remaining amount is an amount that does not interfere with the electrical connection between the semiconductor chip and the substrate when the semiconductor chip having the bump is flip-chip connected to the substrate.

[0315] After the bonding step of manufacturing method (1), if necessary, the surface (back surface) 9b of the semiconductor wafer 9 opposite the bump formation surface 9a is ground, and then a second protective film forming sheet (not shown) is bonded to this back surface 9b.

[0316] <First protective film formation process> After the bonding step of the manufacturing method (1), in the first protective film forming step, first, as shown in FIG. 2C, the intermediate release layer 13 in the first protective film forming sheet 1 is peeled off from the first protective film forming film 14, thereby removing layers of the first protective film forming sheet 1 other than the first protective film forming film 14 from the first protective film forming film 14. In this specification, this step in the first protective film forming step may be referred to as a "removal step". More specifically, the layers to be removed here are the first base material 11, the buffer layer 12, and the intermediate release layer 13. As a result, a semiconductor wafer 914 with a first protective film forming film is obtained, which is configured to include the semiconductor wafer 9 and the first protective film forming film 14 provided on the bump forming surface 9a of the semiconductor wafer 9. The layers other than the first protective film-forming film 14 can be removed from the first protective film-forming film 14 by a known method.

[0317] Since the peeling force between the intermediate release layer 13 and the first protective film-forming film 14 in the test piece prepared from the first protective film-forming sheet 1 is 1000 mN / 25 mm or less, in the removal step (first protective film forming step), when other components, i.e., the laminate of the first base material 11, the buffer layer 12, and the intermediate release layer 13, are peeled from the first protective film-forming film 14, the laminate can be easily peeled off without curing any of these layers, particularly the intermediate release layer 13 adjacent to the first protective film-forming film 14. Typically, the peeling of the laminate from the first protective film-forming film 14 is an interfacial peeling between the intermediate release layer 13 and the first protective film-forming film 14. Furthermore, the remaining of the intermediate release layer 13 is suppressed on the surface 14b of the first protective film-forming film 14 on the intermediate release layer 13 side (sometimes referred to as the "second surface" in this specification).

[0318] In the first protective film forming step of the manufacturing method (1), the first protective film-forming film 14 is then cured to form the first protective film 14' on the bump-forming surface 9a, as shown in Fig. 2D. In this specification, this step in the first protective film forming step is sometimes referred to as a "curing step". As a result, a first protective film-attached semiconductor wafer 914' is obtained, which is composed of the semiconductor wafer 9 and the first protective film 14' provided on the bump-forming surface 9a of the semiconductor wafer 9. The first protective film-forming film 14 is curable, and in this step (the curing step), if the first protective film-forming film 14 is thermosetting, the first protective film-forming film 14 is cured by heating, and if the first protective film-forming film 14 is energy ray curable, the first protective film-forming film 14 is cured by irradiating with energy rays. The heating conditions and the energy ray irradiation conditions at this time are as described above.

[0319] <Dividing process, cutting process> After the first protective film forming step of manufacturing method (1), in the dividing step, the semiconductor wafer 9 is divided to produce semiconductor chips 90, and in the cutting step, the first protective film 14' is cut. Here, the first protective film 14' after cutting is newly given the reference symbol 140'. By performing the dividing and cutting steps, a semiconductor chip 9140' with a first protective film is obtained, which is composed of a semiconductor chip 90 and a first protective film (sometimes simply referred to as the "first protective film" in this specification) 140' after cutting, which is provided on the bump formation surface (surface having bumps) 90a of the semiconductor chip 90, as shown in Figure 2E.

[0320] The dividing step and the cutting step can be carried out by a known method.

[0321] The order of performing the dividing step and the cutting step is not particularly limited, but it is preferable to perform the dividing step and the cutting step simultaneously, or to perform the dividing step and the cutting step in this order. When performing the dividing step and the cutting step in this order, for example, the dividing step may be performed by a known dicing method, and then the cutting step may be performed immediately and continuously thereafter. Dicing can be performed by providing a dicing sheet (not shown) on the back surface 9b of the semiconductor wafer 9 (which may be the back surface after grinding). In the cutting step, the first protective film 14' is cut along the planned or already-divided portions of the semiconductor wafer 9 (in other words, along the outer periphery of the semiconductor chip 90).

[0322] In the semiconductor chip 9140' with the first protective film, the top 9101 of the bump 91 protrudes from the first protective film 140', and the first protective film is not attached at all or almost not attached to the top 910 including the top 9101 of the bump 91, and the attachment of the first protective film to the top 910 of the bump 91 is suppressed. In this specification, "almost no first protective film attached to the top of the bump" means that, unless otherwise specified, although a small amount of the first protective film is attached to the top of the bump, the amount of attachment is such that it does not interfere with the electrical connection between the semiconductor chip and the substrate when the semiconductor chip having the bump is flip-chip connected to the substrate. Typically, the remaining intermediate peeling layer 13 and the like is suppressed on the second surface 140b' of the first protective film 140'.

[0323] <Mounting process> In the mounting step of manufacturing method (1), the semiconductor chip 9140' with the first protective film, in which the tops 9101 of the bumps 91 protrude from the first protective film 140' obtained after the dividing step and the cutting step, is flip-chip connected to a substrate at the tops 9101 of the bumps 91 (not shown). At this time, the semiconductor chip 9140' with the first protective film is connected to the circuit formation surface of the substrate. Since adhesion of the first protective film 140' to the upper portions 910 of the bumps 91 in the semiconductor chip 9140' with the first protective film is suppressed, the degree of electrical connection between the semiconductor chip 90 and the substrate is high in this step.

[0324] When the second protective film forming sheet is used, the first protective film-attached semiconductor chip 9140' is detached from the dicing sheet (not shown) in the second protective film forming sheet and picked up prior to flip-chip connection. The semiconductor chip 9140' with the first protective film can be picked up by a known method. When the second protective film forming sheet is used, the semiconductor chip 90 in the semiconductor chip 9140' with the first protective film has the second protective film after cutting on the rear surface 90b (not shown).

[0325] When the second protective film-forming film in the sheet for forming a second protective film is curable, the second protective film-forming film is cured at an appropriate timing according to its type to form the second protective film. Then, the second protective film is cut at an appropriate timing according to its type.

[0326] The second protective film-forming film can be cured in the same manner as the first protective film-forming film 14, and may be cured simultaneously with the first protective film-forming film 14 or may be cured separately from the first protective film-forming film 14.

[0327] The second protective film can be cut in the same manner as the first protective film. The order of performing the dividing step and the cutting of the second protective film is not particularly limited, but it is preferable to perform the dividing step and the cutting of the second protective film simultaneously, or to perform the cutting of the second protective film after the dividing step. When the dividing step and the cutting of the second protective film are performed in this order, for example, the dividing step may be performed by a known dicing method, and the cutting of the second protective film may be performed immediately after the dividing step. The second protective film is cut along the planned or already-divided portions of the semiconductor wafer 9 (in other words, along the outer periphery of the semiconductor chip 90).

[0328] Thereafter, a semiconductor package is produced according to a known method using the circuit board thus obtained, on which the semiconductor chip 90 is already mounted, and the desired semiconductor device can be manufactured using this semiconductor package (not shown).

[0329] <<Manufacturing method (2)>> Next, the production method (2) will be described. 3A to 3D are cross-sectional views for illustrating an example of the manufacturing method (2) when the first protective film-forming sheet 1 shown in FIG. 1 is used.

[0330] In the bonding step of manufacturing method (2), as shown in Figures 3A to 3B, the first protective film-forming film 14 in the first protective film-forming sheet 1 is bonded to a surface (bump-forming surface) 9a having bumps 91 of the semiconductor wafer 9, and the tops 9101 of the bumps 91 are caused to protrude from the first protective film-forming film 14, thereby providing the first protective film-forming sheet 1 on the semiconductor wafer 9. The bonding step of the manufacturing method (2) is the same as the bonding step of the manufacturing method (1) except that the first protective film-forming film 14 in the sheet for forming a protective film 1 is non-curable instead of curable, and can be performed in the same manner as the bonding step of the manufacturing method (1). Therefore, a further detailed description of the bonding step of the manufacturing method (2) will be omitted.

[0331] In the manufacturing method (2), similarly to the manufacturing method (1), as shown in Fig. 3B, at the stage where the bonding step is completed, none or almost none of the first protective film-forming film 14 remains on the upper portion 910 including the top portion 9101 of the bump 91, and the remaining of the first protective film-forming film 14 is suppressed on the upper portion 910 of the bump 91. When the intermediate release layer 13 in the first protective film-forming sheet 1 contains an ethylene-vinyl acetate copolymer, the first protective film-forming sheet 1 can be bonded at high speed to the bump formation surface 9a of the semiconductor wafer 9, and even in this case, the remaining of the first protective film-forming film 14 is suppressed on the upper portion 910 of the bump 91.

[0332] After the bonding step in manufacturing method (2), if necessary, the surface (back surface) 9b of the semiconductor wafer 9 opposite the bump formation surface 9a is ground, and then a second protective film forming sheet (not shown) is bonded to this back surface 9b.

[0333] <First protective film formation process> After the bonding step of manufacturing method (2), in the first protective film forming step, the intermediate release layer 13 in the first protective film-forming sheet 1 is peeled off from the first protective film-forming film 14, thereby removing the layers of the first protective film-forming sheet 1 other than the first protective film-forming film 14 from the first protective film-forming film 14. In this specification, as in the case of manufacturing method (1), this step in the first protective film forming step may be referred to as the "removal step".

[0334] Since the peeling force between the intermediate release layer 13 and the first protective film-forming film 14 in the test piece prepared from the first protective film-forming sheet 1 is 1000 mN / 25 mm or less, in the same manner as in the case of the manufacturing method (1), in the removing step (first protective film forming step), when other components other than the first protective film-forming film 14, that is, the laminate of the first base material 11, the buffer layer 12, and the intermediate release layer 13 are peeled off from the first protective film-forming film 14, the laminate can be easily peeled off without curing any of these layers, particularly the intermediate release layer 13 adjacent to the first protective film-forming film 14. Typically, the peeling of the laminate from the first protective film-forming film 14 is an interfacial peeling between the intermediate release layer 13 and the first protective film-forming film 14. Furthermore, the remaining intermediate release layer 13 is suppressed on the second surface 14b of the first protective film-forming film 14.

[0335] The removing step is the same as the removing step in the above-mentioned manufacturing method (1) except that the first protective film-forming film 14 in the sheet for forming a protective film 1 is non-curable instead of curable, and can be performed in the same manner as the removing step in the manufacturing method (1). Therefore, the removing step in the manufacturing method (2) will not be described in further detail.

[0336] In the first protective film forming step of the manufacturing method (2), the non-curable first protective film-forming film 14 after removing layers other than the first protective film-forming film 14 is treated as the first protective film. As a result, as shown in FIG. 3C, the first protective film 14' is formed on the bump-forming surface 9a. The non-curable first protective film-forming film 14 also functions as a protective film in that state. Therefore, in this embodiment, the non-curable first protective film-forming film 14 is considered to be the first protective film 14' after the intermediate release layer 13 is removed during use. As a result, a semiconductor wafer 914' with a first protective film is obtained, similarly to the case after the curing step in the manufacturing method (1). Typically, the intermediate peeling layer 13 is prevented from remaining on the second surface 14b' of the first protective film 14'.

[0337] <Dividing process, cutting process> After the first protective film forming step of the manufacturing method (1), in the dividing step, the semiconductor wafer 9 is divided to produce semiconductor chips 90, and in the cutting step, the first protective film 14' is cut. By carrying out the dividing and cutting steps, a semiconductor chip 9140' with a first protective film is obtained, as shown in FIG. 3D.

[0338] Also in manufacturing method (2), in the semiconductor chip 9140' with the first protective film, the tops 9101 of the bumps 91 protrude from the first protective film 140', and the first protective film is not or hardly adheres at all to the upper parts 910 including the tops 9101 of the bumps 91, and adhesion of the first protective film to the upper parts 910 of the bumps 91 is suppressed. And typically, remaining intermediate peeling layer 13 and the like is suppressed on the second surface 140b' of the first protective film 140'.

[0339] The dividing step and the cutting step of the manufacturing method (2) are the same as the dividing step and the cutting step of the manufacturing method (1) except that the first protective film 14' is not a cured product of the first protective film-forming film 14, and can be performed in the same manner as the dividing step and the cutting step of the manufacturing method (1). Therefore, the dividing step and the cutting step of the manufacturing method (2) will not be described in further detail.

[0340] <Mounting process> In the mounting step of manufacturing method (2), the semiconductor chip 9140' with the first protective film, in which the tops 9101 of the bumps 91 protrude from the first protective film 140' obtained after the dividing step and the cutting step, is flip-chip connected to a substrate at the tops 9101 of the bumps 91 (not shown). At this time, the semiconductor chip 9140' with the first protective film is connected to the circuit formation surface of the substrate. Since adhesion of the first protective film 140' to the upper portions 910 of the bumps 91 in the semiconductor chip 9140' with the first protective film is suppressed, the degree of electrical connection between the semiconductor chip 90 and the substrate is high in this step.

[0341] The mounting step of the manufacturing method (2) is the same as the mounting step of the manufacturing method (1) except that the first protective film 140' is not a cured product of the first protective film-forming film 14, and can be performed in the same manner as the mounting step of the manufacturing method (1). Therefore, a further detailed description of the mounting step of the manufacturing method (2) will be omitted.

[0342] In the manufacturing method (2), the same procedure as in the manufacturing method (1) is followed to produce a semiconductor package using a circuit board on which a semiconductor chip 90 is already mounted, and the desired semiconductor device can be manufactured using this semiconductor package (not shown).

[0343] In both manufacturing method (1) and manufacturing method (2), the case where the first protective film-forming sheet 1 shown in FIG. 1 is used has been described here, but even when a first protective film-forming sheet of another embodiment is used, this first protective film-forming sheet achieves the same effect as when the first protective film-forming sheet 1 is used.

[0344] <<Modification of the manufacturing method of the semiconductor device (method of using the first protective film-forming sheet)>> In the manufacturing method of the semiconductor device of this embodiment, a semiconductor wafer can be used in which grooves that become the dividing points of the semiconductor wafer when the semiconductor wafer is divided into individual semiconductor chips are formed on the bump-forming surface. By using such a semiconductor wafer, a semiconductor chip can be manufactured in which the first protective film is provided not only on the bump-forming surface but also on the side surfaces. Here, the side surfaces refer to the outer periphery of the semiconductor chip that is continuous with the bump-forming surface, and a semiconductor chip having a rectangular planar shape has four side surfaces. And, the first protective film is provided on the bump-forming surface and the four side surfaces of the semiconductor chip having a rectangular planar shape. Regardless of the planar shape of the semiconductor chip, a semiconductor chip whose side surfaces are also protected in this way can obtain a higher protective effect by the first protective film.

[0345] In this case, the manufacturing method of the semiconductor device of this embodiment is, for example, a manufacturing method of a semiconductor device using a first protective film-forming sheet according to the above-mentioned embodiment of the present invention, and the manufacturing method includes a step of using a semiconductor wafer having a surface (bump-forming surface) having a bump, the surface having a groove that is to be a dividing portion of the semiconductor wafer, attaching the first protective film-forming film in the first protective film-forming sheet to the surface (bump-forming surface) of the semiconductor wafer having the bump, causing the tops of the bumps to protrude from the first protective film-forming film and filling the grooves with the first protective film-forming film, thereby providing the first protective film-forming sheet on the semiconductor wafer, and after the attaching step, peeling the intermediate release layer in the first protective film-forming sheet from the first protective film-forming film to remove layers of the first protective film-forming sheet other than the first protective film-forming film from the first protective film-forming film, and further, when the first protective film-forming film is curable, curing the first protective film-forming film to form a first protective film, and forming the first protective film by the first protective film-forming film. In the case where the protective film-forming film is non-curable, a first protective film-forming process is performed in which the first protective film-forming film obtained after removing layers other than the first protective film-forming film is treated as a first protective film to form the first protective film on the surface having the bumps (bump-forming surface), and after the first protective film-forming process, a surface (back surface) opposite to the surface having the bumps (bump-forming surface) of the semiconductor wafer is ground, and the ground surface is brought to reach the groove filled with the first protective film (to cause the groove to appear on the opposite surface), thereby dividing the semiconductor wafer. a dividing step of producing a group of semiconductor chips integrated with the first protective film filled in the grooves; a cutting step of cutting the first protective film after the dividing step; and a mounting step of flip-chip connecting the semiconductor chip with the first protective film obtained after the dividing step and the cutting step, the semiconductor chip having the semiconductor chip and the first protective film provided on the surface having the bumps and on the side surfaces of the semiconductor chip, the tops of the bumps protruding from the first protective film, to a substrate at the tops of the bumps.

[0346] Among the modified examples of the manufacturing method of the semiconductor device of this embodiment, a manufacturing method in which the first protective film-forming film is curable (sometimes referred to as "manufacturing method (3)" in this specification) includes a step of using a semiconductor wafer having a surface having bumps (bump-forming surface) on which grooves are formed as dividing points of the semiconductor wafer, attaching the first protective film-forming film in the first protective film-forming sheet to the surface having bumps (bump-forming surface) of the semiconductor wafer, causing the tops of the bumps to protrude from the first protective film-forming film and filling the grooves with the first protective film-forming film, thereby providing the first protective film-forming sheet on the semiconductor wafer, and after the attaching step, peeling the intermediate release layer in the first protective film-forming sheet from the first protective film-forming film to remove layers of the first protective film-forming sheet other than the first protective film-forming film from the first protective film-forming film, and further removing the first protective film-forming film from the first protective film-forming film. The method includes a first protective film forming step of forming the first protective film on the surface having the bumps (bump forming surface) by hardening the first protective film-forming film; a dividing step of grinding the surface (back surface) opposite the surface having the bumps (bump forming surface) of the semiconductor wafer after the first protective film forming step, bringing the ground surface to the grooves filled with the first protective film (making the grooves appear on the opposite surface), and dividing the semiconductor wafer to produce a group of semiconductor chips integrated with the first protective film filled in the grooves; a cutting step of cutting the first protective film after the dividing step; and a mounting step of flip-chip connecting the semiconductor chip with the first protective film, which includes the semiconductor chip obtained after the dividing step and the cutting step, and the first protective film provided on the surface having the bumps and a side surface of the semiconductor chip, and in which the tops of the bumps protrude from the first protective film, to a substrate at the tops of the bumps.

[0347] Among the modified examples of the manufacturing method of the semiconductor device of this embodiment, a manufacturing method in which the first protective film-forming film is non-curable (sometimes referred to as "manufacturing method (4)" in this specification) includes a semiconductor wafer having a surface having bumps (bump-forming surface) on which grooves are formed to be divided, a bonding step of bonding the first protective film-forming film in the first protective film-forming sheet to the surface having bumps (bump-forming surface) of the semiconductor wafer, causing the tops of the bumps to protrude from the first protective film-forming film and filling the grooves with the first protective film-forming film, thereby providing the first protective film-forming sheet on the semiconductor wafer, and a bonding step of bonding the first protective film-forming sheet to the semiconductor wafer by peeling the intermediate release layer in the first protective film-forming sheet from the first protective film-forming film after the bonding step, thereby removing layers of the first protective film-forming sheet other than the first protective film from the first protective film-forming film, and removing layers other than the first protective film from the first protective film-forming film. The method includes a first protective film forming step of forming the first protective film on the surface having the bumps (bump forming surface) by treating the first protective film-forming film after removing the outer layer as a first protective film; a dividing step of grinding the surface (back surface) of the semiconductor wafer opposite the surface having the bumps (bump forming surface) after the first protective film forming step, bringing the ground surface to the grooves filled with the first protective film (making the grooves appear on the opposite surface), and dividing the semiconductor wafer to produce a group of semiconductor chips integrated with the first protective film filled in the grooves; a cutting step of cutting the first protective film after the dividing step; and a mounting step of flip-chip connecting the semiconductor chip with the first protective film, which comprises the semiconductor chip obtained after the dividing step and the cutting step, and the first protective film provided on the surface having the bumps and a side surface of the semiconductor chip, and in which the tops of the bumps protrude from the first protective film, to a substrate at the tops of the bumps.

[0348] The bonding step of the above-mentioned modified examples (manufacturing method (3) and manufacturing method (4)) can be performed in the same manner as the bonding step of the manufacturing method using the above-mentioned semiconductor wafer without grooves (manufacturing method (1) and manufacturing method (2)) except that the semiconductor wafer further has the grooves formed on its bump formation surface. In the bonding step of the above-mentioned modified examples, the same effect as the bonding step of the manufacturing method using the above-mentioned semiconductor wafer without grooves can be obtained. That is, at the stage where the bonding step is completed, the first protective film-forming film does not remain at all or almost does not remain on the upper part including the top part of the bump, and the remaining of the first protective film-forming film is suppressed on the upper part of the bump. In addition, when the intermediate peeling in the first protective film-forming sheet contains ethylene-vinyl acetate copolymer, the first protective film-forming sheet 1 can be bonded at high speed to the bump formation surface of the semiconductor wafer, and even in this case, the remaining of the first protective film-forming film is suppressed on the upper part of the bump.

[0349] The first protective film forming step of the above-mentioned modified examples (manufacturing method (3) and manufacturing method (4)) can be performed in the same manner as the first protective film forming step of the manufacturing method (manufacturing method (1) and manufacturing method (2)) using the above-mentioned semiconductor wafer not having a groove formed therein. In addition, in the first protective film forming step of the above-mentioned modified examples, the same effect as the first protective film forming step of the manufacturing method using the above-mentioned semiconductor wafer not having a groove formed therein can be obtained. That is, when peeling off the other components, that is, the laminate of the first base material, the buffer layer and the intermediate release layer, from the first protective film-forming film, the laminate can be easily peeled off without curing any of these layers, particularly the intermediate release layer adjacent to the first protective film-forming film. Typically, peeling of the laminate from the first protective film-forming film is an interfacial peeling between the intermediate release layer and the first protective film-forming film. In addition, the remaining intermediate release layer is suppressed on the second surface of the first protective film-forming film.

[0350] The division step of the above-mentioned modified examples (manufacturing method (3) and manufacturing method (4)) can be performed in the same manner as the division step of the manufacturing methods (manufacturing method (1) and manufacturing method (2)) using semiconductor wafers not having grooves formed therein, except that the method of dividing the semiconductor wafer is limited to a specific method of grinding the back surface of the semiconductor wafer. The cutting step in the above-mentioned modified examples (manufacturing method (3) and manufacturing method (4)) can be carried out, for example, by attaching a dicing sheet to the surface (back surface) of all the semiconductor chips opposite the surface having the bumps (bump-forming surface), and then cutting the first protective film filled in the grooves along the side surfaces of the semiconductor chips at a location toward the center in the width direction of the grooves. In this way, the first protective film is cut between the side surfaces of adjacent semiconductor chips, and semiconductor chips are obtained with the first protective film provided on these side surfaces. The cutting of the first protective film in this case can be carried out by a known method. After the dividing step and the cutting step in the above-mentioned modified example, similar to the case after the dividing step and the cutting step in the manufacturing method using a semiconductor wafer in which the above-mentioned grooves are not formed, typically, residual intermediate peeling layer, etc. is suppressed on the second surface of the first protective film after cutting.

[0351] The mounting step in the above-mentioned modified examples (manufacturing method (3) and manufacturing method (4)) can be performed in the same manner as the mounting step in the manufacturing methods (manufacturing method (1) and manufacturing method (2)) that use a semiconductor wafer having no grooves formed therein. EXAMPLES

[0352] The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited to the following examples.

[0353] <Materials for producing the composition for forming the first protective film> The raw materials used in the production of the composition for forming the first protective film are shown below. [Polymer component (A)] (A)-1: Polyvinyl butyral having structural units represented by the following formulae (i)-1, (i)-2, and (i)-3 ("S-LEC BL-10" manufactured by Sekisui Chemical Co., Ltd., weight average molecular weight 25000, glass transition temperature 59°C). In the polyvinyl butyral, the proportion of the amount of the structural units represented by the following formula (i)-1 relative to the total amount of the structural units represented by the following formulae (i)-1, (i)-2, and (i)-3 is 68 to 74 mol%, the proportion of the amount of the structural units represented by the following formula (i)-2 is 1 to 3 mol%, and the proportion of the amount of the structural units represented by the following formula (i)-3 is about 28 mol%.

[0354] [ka]

[0355] [Epoxy resin (B1)] (B1)-1: Liquid modified bisphenol A type epoxy resin (DIC Corporation "Epicron EXA-4850-150", molecular weight 900, epoxy equivalent 450g / eq) (B1)-2: Dicyclopentadiene type liquid epoxy resin (DIC "Epicron HP-7200HH", epoxy equivalent 254-264g / eq) [Heat hardener (B2)] (B2)-1: o-cresol type novolak resin (DIC Corporation "Phenolite KA-1160") [Cure accelerator (C)] (C)-1: 2-phenyl-4,5-dihydroxymethylimidazole ("Curezol 2PHZ-PW" manufactured by Shikoku Chemical Industry Co., Ltd.) [Filling material (D)] (D)-1: Spherical silica modified with epoxy groups ("Admanano YA050C-MKK" manufactured by Admatechs Co., Ltd., average particle size 50 nm) [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, Inc.)

[0356] [Example 1] <<Production of the sheet for forming the first protective film>> <Production of Thermosetting First Protective Film-Forming Composition> Polymer component (A)-1 (100 parts by mass), epoxy resin (B1)-1 (320 parts by mass), epoxy resin (B1)-2 (250 parts by mass), heat curing agent (B2)-1 (180 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (160 parts by mass), additive (I)-1 (22 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) having a total concentration of all components other than the solvent of 45% by mass as a composition for forming a thermosetting first protective film. Note that the blending amounts of all components other than the solvent shown here are the blending amounts of the target product excluding the solvent.

[0357] <Production of first protective film-forming film> A release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) made of polyethylene terephthalate film with one side treated for release by silicone treatment was used, and the composition (III) obtained above was applied to the release-treated surface, followed by drying by heating at 120°C for 2 minutes to form a first protective film-forming film (sometimes referred to as "first protective film-forming film (1)" in this specification) having a thickness of 45 μm. The glass transition temperature of this first protective film-forming film (1) was 88°C.

[0358] <Production of composition for forming buffer layer> Monofunctional urethane acrylate (40 parts by mass), isobornyl acrylate (45 parts by mass), 2-hydroxypropyl acrylate (15 parts by mass), pentaerythritol tetrakis(3-mercaptobutyrate) (Showa Denko K.K.'s "KARENZMT (registered trademark) PE1", a secondary tetrafunctional thiol group-containing compound, solid content concentration 100% by mass) (3.5 parts by mass), a crosslinker (1.8 parts by mass), and a photopolymerization initiator (2-hydroxy-2-methyl-1-phenyl-propan-1-one, BASF's "Darocur (registered trademark) 1173", solid content concentration 100% by mass) (1.0 part by mass) were mixed to produce composition (VI).

[0359] <Formation of buffer layer> A PET film (Toyobo Co., Ltd., "Cosmoshine (registered trademark) A4300", thickness 75 μm) was used as the first substrate, and the composition (VI) obtained above was applied onto one side of this first substrate to form a coating film. The coating film was irradiated with ultraviolet light from the outside of its exposed surface side (the side opposite to the PET film side) to form a semi-cured product of the coating film. At this time, a belt conveyor type ultraviolet irradiation device (iGraphics Co., Ltd., "ECS-401GGX") was used as the ultraviolet irradiation device, and a high-pressure mercury lamp (iGraphics Co., Ltd., "H04-L41") was used as the ultraviolet light source, and ultraviolet light with a wavelength of 365 nm was irradiated at an illuminance of 120 mW / cm. 2 , light intensity 200mJ / cm 2 These irradiation conditions were determined using an ultraviolet integrating illuminometer (UVPF-A1, manufactured by iGraphics). Next, the release-treated surface of the release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) was attached to the exposed surface of the obtained semi-cured product to produce a laminate, and ultraviolet rays were irradiated to this laminate from the outside of the release film side to completely cure the semi-cured product, thereby forming a buffer layer with a thickness of 400 μm. At this time, ultraviolet rays with a wavelength of 365 nm and an illuminance of 330 mW / cm were irradiated using the same ultraviolet irradiation device and ultraviolet source as above. 2 , light intensity 1200mJ / cm 2 These irradiation conditions were determined using the same ultraviolet integrating illuminometer as above. In this manner, a laminate sheet (corresponding to the first laminate sheet) was obtained in which the first base material, the buffer layer, and the release film were laminated in this order in the thickness direction.

[0360] <Production of composition for forming intermediate release layer> At room temperature, ethylene-vinyl acetate copolymer (EVA, weight average molecular weight 50,000, VA content 14 mass%, sometimes referred to as "EVA (1)" in this specification) was dissolved in toluene to prepare a toluene solution with a solid concentration of 12 mass%, which was designated as composition (VII).

[0361] <Formation of intermediate peeling layer> The composition (VII) obtained above was applied to the release-treated surface of the release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) and dried by heating at 100°C for 2 minutes to form an intermediate release layer having a thickness of 10 μm.

[0362] <Production of the sheet for forming the first protective film> In the laminated sheet (first laminated sheet) with the buffer layer obtained above, the release film was removed, and the exposed surface of the intermediate release layer obtained above was bonded to the exposed surface of the buffer layer thus obtained, thereby obtaining a laminated sheet (corresponding to the second laminated sheet) further laminated with an intermediate release layer. Next, the release film was removed from the intermediate release layer (in the second laminated sheet) after this bonding, and the exposed surface of the first protective film-forming film obtained above was bonded to the exposed surface of the intermediate release layer thus obtained. As a result of the above, a first protective film-forming sheet with a release film was obtained, which was composed of a first substrate (thickness 75 μm), a buffer layer (thickness 400 μm), an intermediate release layer (thickness 10 μm), a first protective film-forming film (thickness 45 μm) and a release film (thickness 38 μm) laminated in the thickness direction in this order.

[0363] <<Evaluation of the sheet for forming the first protective film>> <<Evaluation of high-speed application of the first protective film forming sheet>> The release film was removed from the first protective film-forming film in the first protective film-forming sheet with the release film obtained above. The exposed surface (the surface opposite to the intermediate release layer side) of the first protective film-forming film in the first protective film-forming sheet thus obtained was pressed against the bump-forming surface of a semiconductor wafer having a diameter of 8 inches and having bumps, thereby attaching the first protective film-forming sheet to the bump-forming surface of the semiconductor wafer. At this time, the semiconductor wafer used had bumps that were approximately spherical in shape, had a height of 210 μm, a width of 250 μm, and a distance between the bumps of 400 μm. The first protective film-forming sheet was attached while heating the first protective film-forming sheet using an attachment device (roller-type laminator, "RAD-3510 F / 12" manufactured by Lintec Corporation) under conditions of a table temperature of 90° C., attachment pressure of 0.5 MPa, and roller attachment height of -400 μm. Such application was carried out multiple times while changing the application speed.

[0364] Next, the semiconductor wafer with the first protective film forming sheet attached was observed through the first protective film forming sheet using a digital microscope. At this time, one location (6 mm x 6 mm) in the center of the semiconductor wafer and four equally spaced locations (each 6 mm x 6 mm) in the vicinity of the outer periphery were selected from the semiconductor wafer, and these five locations were observed such that the direction connecting the two locations near the outer periphery and the one location in the center coincided with the attachment direction of the first protective film forming sheet. Each of these five locations included eight bumps, which means that the peripheral areas of a total of 40 bumps in the semiconductor wafer were observed. If any of these five locations contained air bubbles (in other words, voids between the semiconductor wafer and the first protective film-forming sheet) that were connected between adjacent bumps, it was determined that the first protective film-forming film in the first protective film-forming sheet was not properly attached to the bump-forming surface of the semiconductor wafer, and the application speed of the first protective film-forming sheet when it was properly attached was confirmed. Based on this application speed, the high-speed application property of the first protective film-forming sheet was evaluated according to the following criteria. The results are shown in Table 2. [Evaluation Criteria] A: It can be applied normally at an application speed of 5 mm / s, and has high-speed application properties. B: The tape can be applied normally at an application speed of 3 mm / s, but cannot be applied normally at an application speed of 5 mm / s, and does not have high-speed application properties. C: The sample could not be applied normally at an application speed of 3 mm / s, and was not suitable for application.

[0365] <Evaluation of the bump penetration of the first protective film and the effect of suppressing the remaining part on the bump> The first protective film-forming sheet was applied to the bump-forming surface of the semiconductor wafer in the same manner as in the above "Evaluation of high-speed application of the first protective film-forming sheet", except that the application speed was specified as 5 mm / s. Next, the back surface of the semiconductor wafer was ground using a grinding machine (Disco's "DFG8760") to reduce the thickness of the semiconductor wafer to 250 μm. Next, the first base material, the buffer layer, and the intermediate release layer were removed from the first protective film-forming film using a multi-wafer mounter ("RAD-2700 F / 12" manufactured by Lintec Corporation) to expose the first protective film-forming film. The first protective film-forming film was then heated at 130°C for 4 hours to form the first protective film.

[0366] Next, a dicing sheet (dicing tape "Adwill D-686H" manufactured by Lintec) was attached to the back surface (ground surface) of the semiconductor wafer, and using a blade dicer ("DFD6362" manufactured by Disco) and a dicing blade ("ZH05-SD2000-N1-90CC" manufactured by Disco), the semiconductor wafer was divided into semiconductor chips measuring 6 mm x 6 mm with a blade rotation speed of 30,000 rpm and a blade feed speed of 30 mm / s, and at the same time the first protective film was cut to the same size. As a result of the above, a group of semiconductor chips with a first protective film was obtained, which was composed of a large number (multiple) semiconductor chips with a first protective film, each of which had a semiconductor chip and a first protective film provided on the bump formation surface of the semiconductor chip, aligned and held on a dicing sheet.

[0367] From the group of semiconductor chips with a first protective film obtained as described above, one location in the center and four locations equally spaced from each other near the outer periphery were selected, with the direction connecting the two locations near the outer periphery and the one location in the center being consistent with the attachment direction of the sheet for forming a first protective film.One semiconductor chip with a first protective film was taken out from each of these five locations, for a total of five chips.

[0368] Next, the surfaces of the bumps of the semiconductor chips with the first protective film were observed from a direction that forms an angle of 60° with the direction perpendicular to the bump-forming surface of the semiconductor chip with the first protective film using a scanning electron microscope (SEM, Keyence Corporation "VE-9700"). Then, the presence or absence of the penetration of the bumps through the first protective film and the presence or absence of the attachment of the first protective film to the upper part of the bumps were confirmed. Each of these five semiconductor chips with the first protective film includes eight bumps, that is, the surfaces of 40 bumps in total were observed. The reason for observing the surfaces of the bumps of the semiconductor chips with the first protective film from the direction that forms an angle of 60° described above is that by doing so, the first protective film remaining on the upper part of the bumps is most easily distinguishable. Then, the penetration of the bumps of the first protective film-forming film and the effect of suppressing the remaining of the first protective film-forming film on the upper part of the bumps were evaluated according to the following criteria. The results are shown in Table 2. [Evaluation Criteria] A: All of the bumps penetrated the first protective film, and the first protective film was not attached to the top of any of the bumps. The first protective film-forming film had high bump penetration properties and a high effect of suppressing residue on the top of the bumps. B: One or more bumps did not penetrate the first protective film, or even if they did penetrate, the first protective film was attached to the top of the bump, and the bump penetration ability of the first protective film-forming film was poor or the residue suppression effect on the top of the bump was poor.

[0369] <Measurement of peel force between intermediate release layer and first protective film-forming film> A piece having a width of 25 mm and a length of 150 mm was cut out from the sheet for forming the first protective film obtained above, and the release film was removed from the first protective film-forming film in this piece to prepare a test piece. Under an environment of a temperature of 23°C and a relative humidity (RH) of 50%, the entire exposed surface of the first protective film-forming film in the test piece was attached to the #600 polished surface of a stainless steel (SUS) plate ("SUS304 #600HL, thickness 0.5 mm, size 70 mm x 150 mm" manufactured by Paltec Co., Ltd.) via double-sided tape to prepare a SUS plate with a test piece. At this time, the test piece was attached using a rubber roller with a mass of 2 kg. The obtained SUS plate with the test piece was left as it was for 20 minutes, and then placed in an oven heated to 90°C and left for 5 minutes. Next, the SUS plate with the test piece was removed from the oven and left to stand for 2 hours in an environment with a temperature of 23°C and a relative humidity (RH) of 50%, thereby subjecting the SUS plate with the test piece to a humidity conditioning treatment.

[0370] Subsequently, in an environment of a temperature of 23°C and a relative humidity of 50%, the laminate of the first base material, the buffer layer and the intermediate release layer was peeled off from the first protective film-forming film at a peeling speed of 100 mm / min on the SUS plate with the test piece after the humidity conditioning treatment. At this time, the angle between the surface of the first protective film-forming film to which the intermediate release layer was attached and the surface of the intermediate release layer to which the first protective film-forming film was attached was set to 180°, and the intermediate release layer (the laminate) was peeled off in its length direction (180° peeling was performed). Then, the load at this 180° peeling was measured, and the measurement length was set to 140 mm, and the measurement value at the first length of 5 mm and the measurement value at the last length of 5 mm were excluded from the effective value. Then, the average value of the measured values ​​was adopted as the peel force between the intermediate release layer and the first protective film-forming film. The results are shown in Table 2.

[0371] <<Production and evaluation of the first protective film forming sheet>> [Example 2] Composition (III) having the same composition as in Example 1, except that the contents of epoxy resin (B1)-1, epoxy resin (B1)-2, heat curing agent (B2)-1 and filler (D)-1 were different as shown in Table 1, was produced in the same manner as in Example 1. Then, a first protective film-forming film (sometimes referred to as "first protective film-forming film (2)" in this specification) was produced in the same manner as in Example 1, except that this composition (III) was used, and a sheet for forming a first protective film was produced and evaluated. The results are shown in Table 2. The glass transition temperature of the first protective film-forming film (2) was 81°C.

[0372] [Example 3] A sheet for forming a first protective film was produced and evaluated in the same manner as in Example 1, except that an ethylene-vinyl acetate copolymer (weight average molecular weight 65,000, VA content 28 mass%, sometimes referred to as "EVA (2)" in this specification) was used instead of EVA (1) (weight average molecular weight 50,000, VA content 14 mass%) when producing the composition for forming an intermediate release layer (composition (VII)). The results are shown in Table 2.

[0373] [Comparative Example 1] A sheet for forming a first protective film was produced and evaluated in the same manner as in Example 1, except that an ethylene-vinyl acetate copolymer (weight average molecular weight 155,000, VA content 42 mass%, sometimes referred to as "EVA (3)" in this specification) was used instead of EVA (1) (weight average molecular weight 50,000, VA content 14 mass%) when producing the composition for forming an intermediate release layer (composition (VII)). The results are shown in Table 2.

[0374] <<Production of the sheet for forming the first protective film>> [Comparative Example 2] <Production of Pressure-Sensitive Adhesive Composition> An acrylic copolymer obtained by copolymerizing 2-ethylhexyl acrylate (80 parts by mass) and 2-hydroxyethyl acrylate (20 parts by mass) was used, and 2-isocyanatoethyl methacrylate ("KarenzMOI (registered trademark)" manufactured by Showa Denko KK) was added to the acrylic copolymer so that the addition ratio relative to the hydroxyl groups (100 equivalents) of the structural units derived from 2-hydroxyethyl acrylate in the acrylic copolymer was 80 equivalents, thereby obtaining an acrylic polymer (weight average molecular weight 800,000).

[0375] To this acrylic polymer (100 parts by mass), 1-hydroxycyclohexyl phenyl ketone (photopolymerization initiator, BASF's "Irgacure (registered trademark) 184") (3 parts by mass) and trimethylolpropane adduct tolylene diisocyanate (crosslinking agent, Tosoh's "Coronate (registered trademark) L") (1.1 parts by mass) were added, and a liquid was prepared using methyl ethyl ketone. This liquid was stirred for 30 minutes to prepare a pressure-sensitive adhesive composition in solution form with a solid content concentration of 20% by mass.

[0376] <Production of the sheet for forming the first protective film> The adhesive composition obtained above was applied to the release-treated surface of the release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) and dried by heating at 120°C for 2 minutes to form an energy ray-curable adhesive layer having a thickness of 10 μm.

[0377] A first protective film-forming sheet was produced in the same manner as in Example 1, except that the pressure-sensitive adhesive layer obtained above was used instead of the intermediate release layer.

[0378] <<Evaluation of the sheet for forming the first protective film>> The sheet for forming a first protective film obtained above was evaluated in the same manner as in Example 1. However, when "measuring the peel strength between the intermediate release layer and the first protective film-forming film", unlike in Example 1, the SUS plate with the test piece after the humidity conditioning treatment was further irradiated with ultraviolet light having a wavelength of 365 nm and an illuminance of 230 mW / cm 2, light intensity 1120mJ / cm 2 The pressure-sensitive adhesive layer was cured with energy rays by irradiating the adhesive layer under the above conditions, and then the peel strength between the cured product and the first protective film-forming film was measured. At this time, the same ultraviolet irradiating device and ultraviolet source as those used in forming the buffer layer were used, and the irradiation conditions were also specified using the same ultraviolet integrating illuminometer as those used in forming the buffer layer. The results are shown in Table 2.

[0379] [Table 1]

[0380] [Table 2]

[0381] As is clear from the above results, in Examples 1 to 3, the peel force between the intermediate release layer and the first protective film-forming film was 900 mN / 25 mm or less, and was suppressed to a low level within an appropriate range. That is, after the first protective film-forming sheets of Examples 1 to 3 were attached to the bump formation surface of the semiconductor wafer, the laminate of the first base material, the buffer layer, and the intermediate release layer had good peelability from the protective film-forming film. Furthermore, in Examples 1 to 3, the first protective film-forming sheet could be normally attached to the bump-forming surface of the semiconductor wafer at an attachment speed of 5 mm / s by the first protective film-forming film therein, and the first protective film-forming sheet had high-speed attachment properties. Even when attached at such a high speed, adhesion of the first protective film to the upper part of the bump could be suppressed, that is, the top of the bump could be made to protrude from the first protective film-forming film, and the first protective film-forming film could be suppressed from remaining in the upper part including the top of the bump.

[0382] In Examples 1 to 3, the intermediate release layer contained EVA, the VA content of the EVA was 28 mass % or less, and the weight average molecular weight of the EVA was 65,000 or less.

[0383] In contrast, in Comparative Example 1, the peeling force between the intermediate release layer and the first protective film-forming film was 50000 mN / 25 mm, which was extremely large. That is, after the first protective film-forming sheet of Comparative Example 1 was attached to the bump formation surface of the semiconductor wafer, the peeling property of the laminate of the first base material, the buffer layer, and the intermediate release layer from the protective film-forming film was significantly poor. In Comparative Example 1, the intermediate release layer contained EVA, and the VA content of the EVA was 42 mass %, and the weight average molecular weight of the EVA was 155,000.

[0384] In Comparative Example 2, the peeling force between the energy ray-cured product of the pressure-sensitive adhesive layer and the first protective film-forming film was 1200 mN / 25 mm, which was large. That is, after the first protective film-forming sheet of Comparative Example 2 was attached to the bump formation surface of the semiconductor wafer, the peeling property of the laminate of the first base material, the buffer layer, and the energy ray-cured product of the pressure-sensitive adhesive layer from the protective film-forming film was poor. In Comparative Example 2, the first protective film-forming sheet could be normally attached to the bump-forming surface of the semiconductor wafer at an attachment speed of 3 mm / s by using the first protective film-forming film therein, but could not be normally attached at an attachment speed of 5 mm / s, and the first protective film-forming sheet did not have high-speed attachment properties. Furthermore, when attached at an attachment speed of 5 mm / s, the adhesion of the first protective film on the upper part of the bumps could not be suppressed. That is, in Comparative Example 2, when the first protective film-forming sheet was attached to the bump-forming surface of the semiconductor wafer at an attachment speed of 5 mm / s, the remaining of the first protective film-forming film on the upper part of the bumps could not be suppressed. The first protective film-forming sheet of Comparative Example 2 had a pressure-sensitive adhesive layer containing an acrylic polymer, rather than an intermediate release layer containing EVA. [Industrial Applicability]

[0385] INDUSTRIAL APPLICABILITY The present invention can be utilized in the manufacture of a semiconductor chip for use in a flip chip connection method, the semiconductor chip having bumps and a protective film on the bump-formed surface. [Explanation of symbols]

[0386] 1...First protective film forming sheet, 11...first base material, 12...buffer layer, 13: intermediate release layer; 13a: a surface of the intermediate release layer opposite to the buffer layer (a first surface of the intermediate release layer); 14: first protective film-forming film; 14b: a surface of the first protective film-forming film on the intermediate release layer side (a second surface of the first protective film-forming film); 14'...first protective film; 140'...first protective film after cutting; 9: semiconductor wafer; 9a: bump-formed surface of the semiconductor wafer (surface of the semiconductor wafer having bumps); 90: semiconductor chip; 90a: bump formation surface of the semiconductor chip (surface of the semiconductor chip having bumps); 91···bump, 9101···bump top, 9140'···First protective film-coated semiconductor chip

Claims

1. A first protective film forming sheet for forming a first protective film on at least a bump-bearing surface of a semiconductor wafer, The first protective film-forming sheet is configured by laminating a first base material, a buffer layer, an intermediate release layer, and a first protective film-forming film in this order in a thickness direction, A first protective film-forming sheet, in which a test piece of the first protective film-forming sheet having a width of 25 mm is used, the intermediate release layer is peeled off from the first protective film-forming film, and a peel test is performed in which the angle between the surface of the first protective film-forming film on which the intermediate release layer was attached and the surface of the intermediate release layer on which the first protective film was attached is set to 180°, and the intermediate release layer is peeled off from the first protective film-forming film in its length direction at a peel speed of 100 mm / min., the peel force between the intermediate release layer and the first protective film-forming film is 1000 mN / 25 mm or less.

2. the intermediate release layer comprises an ethylene-vinyl acetate copolymer; 2. The sheet for forming a first protective film according to claim 1, wherein in the ethylene-vinyl acetate copolymer, the ratio of the amount of structural units derived from vinyl acetate to the total amount of structural units is 40 mass% or less.

3. 3. The first protective film-forming sheet according to claim 2, wherein the ethylene-vinyl acetate copolymer has a weight average molecular weight of 200,000 or less.

4. A method for manufacturing a semiconductor device using the first protective film-forming sheet according to any one of claims 1 to 3, The manufacturing method includes a bonding step of bonding the first protective film-forming film in the first protective film-forming sheet to a surface of a semiconductor wafer having bumps, and causing tops of the bumps to protrude from the first protective film-forming film, thereby providing the first protective film-forming sheet on the semiconductor wafer; a first protective film forming step of removing layers of the first protective film-forming sheet other than the first protective film-forming film from the first protective film-forming film by peeling the intermediate release layer in the first protective film-forming sheet from the first protective film-forming film after the attaching step, and further, when the first protective film-forming film is curable, curing the first protective film-forming film to form a first protective film, and when the first protective film-forming film is non-curable, treating the first protective film-forming film after removing layers other than the first protective film-forming film as a first protective film to form the first protective film on the surface having the bumps; a dividing step of dividing the semiconductor wafer into semiconductor chips after the first protective film forming step; a cutting step of cutting the first protective film after the first protective film forming step; A method for manufacturing a semiconductor device, comprising: the semiconductor chip obtained after the dividing step and the cutting step; and the first protective film provided on a surface of the semiconductor chip having the bumps, and a mounting step of flip-chip connecting the semiconductor chip with the first protective film, in which the tops of the bumps protrude from the first protective film, to a substrate at the tops of the bumps.

5. The method for manufacturing a semiconductor device according to claim 4 , wherein in the attaching step, the first protective film-forming film is attached to the surface of the semiconductor wafer having the bumps at an attachment speed of 4 mm / s or more.

6. Use of a sheet for forming a first protective film on at least a bump-bearing surface of a semiconductor wafer, comprising: the sheet is a first protective film-forming sheet configured by laminating a first base material, a buffer layer, an intermediate release layer, and a first protective film-forming film in this order in a thickness direction; A use of a sheet in which a test piece of the first protective film-forming sheet having a width of 25 mm is used, the intermediate release layer is peeled from the first protective film-forming film, and a peel test is performed in which the angle between the surface of the first protective film-forming film to which the intermediate release layer was attached and the surface of the intermediate release layer to which the first protective film-forming film was attached is set to 180°, and the intermediate release layer is peeled from the first protective film-forming film in its length direction at a peel speed of 100 mm / min, and the peel force between the intermediate release layer and the first protective film-forming film is 1000 mN / 25 mm or less.

Images