Method for manufacturing a composite sheet for forming a protective film and a semiconductor device.

Abstract

The present invention provides a composite sheet for forming a protective film that exhibits low peeling force when separating the base material, buffer layer, and intermediate release layer, and also has excellent cutability. [Solution] A composite sheet 1 for forming a protective film on a protruding electrode surface, wherein the base material 10 includes a core material layer 11 and a soft material layer 12, the soft material layer provided on one side of the core material layer is in contact with a protective film forming film 13, the peel force after heat lamination with the two base materials overlapping so that the soft material layers are in contact with each other is 3,000 mN / 25 mm or less, the load deflection temperature of the core material layer is higher than the application temperature, the load deflection temperature of the soft material layer is lower than the application temperature, and the peel force when peeling the base material from the protective film forming film is greater than 40 mN / 100 mm and less than 3,000 mN / 100 mm.

Description

[Technical Field]

[0001] The present invention relates to a composite sheet for forming a protective film and a method for manufacturing a semiconductor device. [Background technology]

[0002] In recent years, semiconductor devices have been manufactured using a mounting method known as the face-down method. In the face-down method, a semiconductor chip with bumps on its circuit surface and a substrate for mounting the semiconductor chip are stacked so that the circuit surface of the semiconductor chip and the substrate face each other, thereby mounting the semiconductor chip onto the substrate. Typically, these semiconductor chips are obtained by slicing a semiconductor wafer, which has bumps on its circuit surface, into individual pieces.

[0003] Incidentally, semiconductor wafers equipped with protruding electrodes such as bumps may have a protective film provided to protect the junction between the protruding electrode and the semiconductor wafer (hereinafter also referred to as the "base portion"). For example, Patent Document 1 discloses a composite sheet for forming a protective film, in which a substrate, a buffer layer, an intermediate release layer, and a protective film-forming film are laminated in this order. The composite sheet for forming a protective film is attached to the bump-forming surface of a semiconductor wafer, cut along the shape of the semiconductor wafer, and then the layers other than the protective film-forming film (substrate, buffer layer, and intermediate release layer) are peeled off from the protective film-forming film. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2023 / 136053 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the above-mentioned composite sheet for forming protective films exhibits a slightly high peeling force when separating layers other than the protective film (substrate, buffer layer, and intermediate release layer) from the protective film, and improvement in this regard is desired. Furthermore, excellent cutability is also required for the composite sheet for forming protective films.

[0006] Therefore, the object of the present invention is to provide a composite sheet for forming a protective film that has low peeling force when peeling layers other than the protective film from the protective film forming film, and also has excellent cutability. [Means for solving the problem]

[0007] The present invention provides the following [1] to [7]. [1] A composite sheet for forming a protective film, used to form a protective film on the protruding electrode surface of a member with a protruding electrode, having a laminated structure in which a protective film forming film and a substrate are laminated, The substrate includes a core material layer and a soft material layer. The soft material layer is provided on at least one surface of the core material layer, The soft material layer provided on at least one side of the core material layer is in direct contact with the protective film forming film, Two of the aforementioned substrates are prepared, and the two substrates are stacked so that the soft material layers are in contact with each other, and then heat-laminated at 80°C and 0.3 MPa. The peeling force between the soft material layers when peeling one substrate from the other is 3,000 mN / 25 mm or less. The load deflection temperature (T1) of the core material layer is higher than the bonding temperature when the protective film-forming composite sheet is attached to the protruding electrode forming surface of the member with the protruding electrode. The load deflection temperature (T2) of the soft material layer is lower than the application temperature when the protective film-forming composite sheet is applied to the protruding electrode forming surface of the member with the protruding electrode. A composite sheet for forming a protective film, wherein the peeling force when peeling the substrate from the protective film is greater than 40 mN / 100 mm and less than 3,000 mN / 100 mm. [2] A composite sheet for forming a protective film, used to form a protective film on the protruding electrode surface of a member with a protruding electrode, having a laminated structure in which a protective film forming film and a substrate are laminated, The substrate includes a core material layer and a soft material layer. The soft material layer is provided on at least one surface of the core material layer, The soft material layer provided on at least one side of the core material layer is in direct contact with the protective film forming film, Two of the aforementioned substrates are prepared, and the two substrates are stacked so that the soft material layers are in contact with each other, and then heat-laminated at 80°C and 0.3 MPa. The peeling force between the soft material layers when peeling one substrate from the other is 3,000 mN / 25 mm or less. The load deflection temperature (T1) of the core material layer is 50°C or higher. The load deflection temperature (T2) of the aforementioned soft material layer is 90°C or less. The load deflection temperature (T1) of the core material layer is greater than the load deflection temperature (T2) of the soft material layer. A composite sheet for forming a protective film, wherein the peeling force when peeling the substrate from the protective film is greater than 40 mN / 100 mm and less than 3,000 mN / 100 mm. [3] A composite sheet for forming a protective film, used to form a protective film on the protruding electrode surface of a member with a protruding electrode, having a laminated structure in which a protective film forming film and a substrate are laminated, The substrate includes a core material layer and a soft material layer. The soft material layer is provided on at least one surface of the core material layer, The soft material layer provided on at least one side of the core material layer is in direct contact with the protective film forming film, Two of the aforementioned substrates are prepared, and the two substrates are stacked so that the soft material layers are in contact with each other, and then heat-laminated at 80°C and 0.3 MPa. The peeling force between the soft material layers when peeling one substrate from the other is 3,000 mN / 25 mm or less. The load deflection temperature (T1) of the core material layer is 80°C or higher. The soft material layer has a load deflection temperature (T2) of 80°C or lower, The core material layer has a load deflection temperature (T1) greater than the load deflection temperature (T2) of the soft material layer, A composite sheet for forming a protective film, wherein the peel force when peeling the base material from the protective film-forming film is more than 40 mN / 100 mm and less than 3,000 mN / 100 mm. [4] The composite sheet for forming a protective film according to any one of the above [1] to [3], wherein the soft material layer is a polyolefin resin layer. [5] The composite sheet for forming a protective film according to any one of the above [1] to [3], wherein the core material layer is a polyethylene terephthalate resin layer. [6] A method for manufacturing a semiconductor device, comprising the step of forming a protective film on the protruding electrode forming surface of a member with protruding electrodes using the composite sheet for forming a protective film according to any one of the above [1] to [3]. [7] The member with protruding electrodes is a semiconductor wafer having a protruding electrode forming surface provided with protruding electrodes, and includes the following steps (S1) to (S4), ·Step (S1): A step of preparing a wafer for manufacturing semiconductor chips, in which grooves as planned dividing lines are formed on the protruding electrode forming surface of the semiconductor wafer without reaching the back surface ·Step (S2): A step of attaching the protective film-forming film of the composite sheet for forming a protective film to the protruding electrode forming surface of the wafer for manufacturing semiconductor chips, covering the protruding electrode forming surface of the wafer for manufacturing semiconductor chips with the protective film-forming film, and embedding the protective film-forming film into the grooves formed in the wafer for manufacturing semiconductor chips ·Step (S3): A step of curing the protective film-forming film to obtain a wafer for manufacturing semiconductor chips with a protective film ·Step (S4): A step of dicing the wafer for manufacturing semiconductor chips with a protective film along the planned dividing lines to obtain semiconductor chips at least the protruding electrode forming surfaces and side surfaces of which are covered with the protective film Further, the method for manufacturing a semiconductor device according to the above [6], comprising the following step (S-BG) after the step (S2) and before the step (S3), after the step (S3) and before the step (S4), or in the step (S4). Effects of the Invention

[0008] According to the present invention, it is possible to provide a composite sheet for forming a protective film that has low peeling force when peeling a layer (substrate) other than the protective film-forming film from the protective film-forming film, and also has excellent cuttability. Brief Description of the Drawings

[0009] [Figure 1] It is a schematic cross-sectional view showing an example of the composite sheet for forming a protective film of the present embodiment. [Figure 2] It is a schematic cross-sectional view showing another example of the composite sheet for forming a protective film of the present embodiment. [Figure 3] It is a schematic cross-sectional view showing a part of the method for manufacturing a semiconductor device according to the first aspect of the present embodiment. [Figure 4] It is a schematic cross-sectional view showing a part of the method for manufacturing a semiconductor device according to the first aspect of the present embodiment. [Figure 5] It is a schematic cross-sectional view showing a part of the method for manufacturing a semiconductor device according to the first aspect of the present embodiment. [Figure 6] It is a schematic cross-sectional view showing a part of the method for manufacturing a semiconductor device according to the first aspect of the present embodiment. [Figure 7] In the method for manufacturing a semiconductor device according to the second aspect of the present embodiment, it is a schematic cross-sectional view showing an example of a wafer for producing semiconductor chips prepared in step (S1). [Figure 8] It is a diagram showing an outline of step (S2) in the method for manufacturing a semiconductor device according to the second aspect of the present embodiment. [Figure 9] It is a diagram showing an outline of step (S3) in the method for manufacturing a semiconductor device according to the second aspect of the present embodiment. [Figure 10] It is a diagram showing an outline of step (S4) in the method for manufacturing a semiconductor device according to the second aspect of the present embodiment. [Figure 11] This figure shows a schematic of the process (S-BG) in the method for manufacturing a semiconductor device according to the second embodiment of this model. [Figure 12] This figure illustrates how to overlap the substrates when evaluating self-adhesion (peelability) in Example 4. [Modes for carrying out the invention]

[0010] In this specification, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are values ​​on a standard polystyrene basis measured by gel permeation chromatography (GPC), specifically values ​​measured based on the method described in the Examples.

[0011] In this specification, the lower and upper limits described in steps for a preferred numerical range (e.g., range of content, etc.) can be combined independently. For example, from the description "preferably 10 to 90, more preferably 30 to 60", the "preferred lower limit (10)" and the "more preferred upper limit (60)" can be combined to arrive at "10 to 60".

[0012] In this specification, "energy beam" means an electromagnetic wave or charged particle beam that has an energy quantum. Examples of energy beams include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated using electrodeless lamps, high-pressure mercury lamps, metal halide lamps, xenon lamps, black lights, LED lamps, etc. Electron beams can be irradiated using those generated by electron accelerators, etc. Furthermore, in this specification, "energy ray curability" means the property of hardening by irradiation with energy rays, and "thermosetting property" means the property of hardening by heating.

[0013] In this specification, for example, "(meth)acrylic acid" refers to both "acrylic acid" and "methacrylic acid," and the same applies to other similar terms.

[0014] In this specification, the "circuit side" of a semiconductor wafer and semiconductor chip refers to the side on which the circuit is formed, and the "back side" of a semiconductor wafer and semiconductor chip refers to the side opposite to the circuit side.

[0015] In this specification, the "thickness" of an object means the total thickness of the object as a whole. For example, if the object consists of multiple layers, it means the total thickness of all the layers that make up the object. In this specification, unless otherwise specified, the "thickness" of an object refers to the average value of the thickness measured at five randomly selected locations on the object, and can be obtained using a constant-pressure thickness measuring instrument in accordance with JIS K 7130:1999.

[0016] In this specification, "solid content" or "active ingredient" refers to the components of the composition in question, excluding diluting solvents such as water and organic solvents.

[0017] The mechanism of action described herein is speculative and does not limit the mechanism by which the present invention achieves its effects.

[0018] In order to make the features of the present invention easier to understand, the drawings may show enlarged versions of key parts for convenience, and the dimensional ratios of each component may not be the same as in reality.

[0019] [Aspects of the composite sheet for forming a protective film according to this embodiment] The protective film-forming composite sheet of this embodiment is used to form a protective film on the protruding electrode forming surface of a member with a protruding electrode, and is a protective film-forming composite sheet having a laminated structure in which a protective film-forming film and a substrate are laminated together. The substrate includes a core material layer and a soft material layer. The soft material layer is provided on at least one surface of the core material layer, The soft material layer provided on at least one side of the core material layer is in direct contact with the protective film forming film, Two of the aforementioned substrates are prepared, and the two substrates are stacked so that the soft material layers are in contact with each other, and then heat-laminated at 80°C and 0.3 MPa. The peeling force between the soft material layers when peeling one substrate from the other is 3,000 mN / 25 mm or less. The load deflection temperature (T1) of the core material layer is higher than the bonding temperature when the protective film-forming composite sheet is attached to the protruding electrode forming surface of the member with the protruding electrode. The load deflection temperature (T2) of the soft material layer is lower than the application temperature when the protective film-forming composite sheet is applied to the protruding electrode-forming surface of the member with the protruding electrode. The peeling force when peeling the substrate from the protective film is greater than 40 mN / 100 mm and less than 3,000 mN / 100 mm.

[0020] Another embodiment of the protective film-forming composite sheet is used to form a protective film on the protruding electrode forming surface of a member with a protruding electrode, and is a protective film-forming composite sheet having a laminated structure in which a protective film-forming film and a substrate are laminated, The substrate includes a core material layer and a soft material layer. The soft material layer is provided on at least one surface of the core material layer, The soft material layer provided on at least one side of the core material layer is in direct contact with the protective film forming film, Two of the aforementioned substrates are prepared, and the two substrates are stacked so that the soft material layers are in contact with each other, and then heat-laminated at 80°C and 0.3 MPa. The peeling force between the soft material layers when peeling one substrate from the other is 3,000 mN / 25 mm or less. The load deflection temperature (T1) of the core material layer is 50°C or higher. The load deflection temperature (T2) of the aforementioned soft material layer is 90°C or less. The load deflection temperature (T1) of the core material layer is greater than the load deflection temperature (T2) of the soft material layer. The peeling force when peeling the substrate from the protective film is greater than 40 mN / 100 mm and less than 3,000 mN / 100 mm.

[0021] A composite sheet for forming a protective film in yet another embodiment of this embodiment is used to form a protective film on the protruding electrode forming surface of a member with a protruding electrode, and is a composite sheet for forming a protective film having a laminated structure in which a protective film forming film and a substrate are laminated, The substrate includes a core material layer and a soft material layer. The soft material layer is provided on at least one surface of the core material layer, The soft material layer provided on at least one side of the core material layer is in direct contact with the protective film forming film, Two of the aforementioned substrates are prepared, and the two substrates are stacked so that the soft material layers are in contact with each other, and then heat-laminated at 80°C and 0.3 MPa. The peeling force between the soft material layers when peeling one substrate from the other is 3,000 mN / 25 mm or less. The load deflection temperature (T1) of the core material layer is 80°C or higher. The load deflection temperature (T2) of the aforementioned soft material layer is 80°C or less. The load deflection temperature (T1) of the core material layer is greater than the load deflection temperature (T2) of the soft material layer. The peeling force when peeling the substrate from the protective film is greater than 40 mN / 100 mm and less than 3,000 mN / 100 mm.

[0022] The inventors diligently conducted research to solve the above problems. As a result, they found that the composite sheet for forming a protective film with the above configuration exhibits low peeling force when peeling the substrate from the protective film and also has excellent cutability. After further various studies, they completed the present invention.

[0023] The protective film-forming film and substrate constituting the protective film-forming composite sheet of this embodiment will be described below, followed by a detailed explanation of the structure of the protective film-forming composite sheet and the method for manufacturing the semiconductor device.

[0024] <Film for forming protective film> The protective film in this embodiment is composed of a curable resin film (x). The curable resin film (x), upon curing, becomes a highly protective film with excellent protective properties, such as protection of the surface on which the protruding electrode is formed (especially the protection of the base of the bump if the protruding electrode is a bump) and impact resistance. The curable resin film (x) may be thermosetting, which hardens by heating, or energy ray curable, which hardens by energy ray irradiation. However, from the viewpoint of ensuring high temperature and high fluidity and improving conformability to protruding electrodes, it is preferable that it be a thermosetting resin film (x1). Furthermore, from the viewpoint of making it easier to ensure high temperature and high fluidity of the curable resin film (x), the loss tangent tanδ of the curable resin film (x) at 80°C before curing is preferably 2.5 or less, more preferably 1.8 or less, and even more preferably 1.2 or less. The loss tangent tanδ of the curable resin film (x) at 80°C before curing can be measured by the method described in the examples below. Furthermore, in this embodiment, "before curing" means the state before the curable resin film (x) is subjected to heat curing or energy ray curing. For example, a curable resin composition (x-1) described later that has been dried (drying temperature 70-130°C, drying time 10 seconds-5 minutes) is also included in the "before curing" curable resin film (x).

[0025] The loss tangent tanδ of the curable resin film (x) at 80°C before curing can be adjusted to the above range by adjusting one or both of the types and contents of the components contained in the curable resin composition for forming the curable resin film (x). Here, a particularly effective method for adjusting the loss tangent tanδ of the curable resin film (x) at 80°C before curing to the above range is, for example, using a flexible epoxy resin as the thermosetting component (B). However, the method for controlling the loss tangent tanδ of the curable resin film (x) at 80°C before curing is not limited to this.

[0026] The curable resin film (x) may consist of only one layer or two or more layers. If the curable resin film (x) consists of multiple layers, these layers may be identical or different from each other, and the combination of these layers is not particularly limited.

[0027] The thickness of the curable resin film (x) is not particularly limited, but is preferably 10 to 70 μm, more preferably 15 to 60 μm, and even more preferably 15 to 50 μm. When the thickness of the curable resin film (x) is greater than or equal to the lower limit, it is easier to produce a sheet with high in-plane uniformity, and a protective film with higher protective capacity tends to be formed. Conversely, when the thickness of the curable resin film (x) is less than or equal to the upper limit, the protective film is less likely to become excessively thick. The thickness of the curable resin film (x) can be adjusted based on the relationship between the thickness of the curable resin film (x) and the thickness of the protective film formed by curing the curable resin film (x), as well as information such as the height of the protruding electrode on the component with the protruding electrode to be used. The thermosetting resin film (x1) and the energy ray curable resin film (x2) will be described below.

[0028] (Thermosetting resin film (x1)) The thermosetting resin film (x1) contains a polymer component (A) and a thermosetting component (B). The thermosetting resin film (x1) is formed, for example, from a thermosetting resin composition (x1-1) containing a polymer component (A) and a thermosetting component (B). Polymeric component (A) is a component that can be considered to have been formed by a polymerization reaction of polymerizable compounds. Thermosetting component (B) is a component that can undergo a curing (polymerization) reaction triggered by heat. This curing (polymerization) reaction includes polycondensation reactions.

[0029] (Polymer component (A)) The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) contain a polymer component (A). Polymer component (A) is a polymer compound used to impart film-forming properties, flexibility, and other characteristics to the thermosetting resin film (x1). Polymer component (A) may be used alone or in combination of two or more types. When two or more polymer components (A) are used in combination, the combination and ratio can be arbitrarily selected.

[0030] Examples of polymer components (A) include acrylic resins, polyarylate resins, polyacetal resins, polyesters, urethane resins (resins having urethane bonds), acrylic urethane resins, silicone resins (resins having siloxane bonds), rubber resins (resins having a rubber structure), phenoxy resins, and thermosetting polyimides. Among these, acrylic resins, polyarylate resins, and polyacetal resins are preferred, with polyacetal resins being more preferred.

[0031] -Acrylic resin- Examples of acrylic resins include well-known acrylic polymers. The weight-average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, more preferably 300,000 to 1,500,000, and even more preferably 500,000 to 1,000,000. Having a weight-average molecular weight of the acrylic resin above the lower limit mentioned above makes it easier to improve the shape stability (stable over time during storage) of the thermosetting resin film (x1). Also, having a weight-average molecular weight of the acrylic resin below the upper limit mentioned above makes it easier for the thermosetting resin film (x1) to conform to the uneven surface of the adherend, for example, making it easier to suppress the generation of voids between the adherend and the thermosetting resin film (x1). Therefore, the coverage of the surface on which protruding electrodes are formed is improved, and the ability to fill grooves that these surfaces may have is also improved.

[0032] The glass transition temperature (Tg) of the acrylic resin is preferably -60 to 70°C, more preferably -40 to 50°C, and even more preferably -30 to 30°C, from the viewpoint of the adhesiveness and handling properties of the thermosetting resin film (x1).

[0033] Examples of acrylic resins include polymers of one or more (meth)acrylic acid esters; copolymers of two or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide, etc.

[0034] Examples of (meth)acrylic acid esters that constitute acrylic resins 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 (meth) Alkyl methacrylates 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), in which the alkyl group constituting the alkyl ester has a chain structure with 1 to 18 carbon atoms; Cycloalkyl esters of (meth)acrylates, such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (meth)acrylate aralkyl esters such as benzyl (meth)acrylate; (meth)acrylate dicyclopentenyl ester and other cycloalkenyl (meth)acrylates; (meth)acrylate cycloalkenyloxyalkyl esters such as (meth)acrylate dicyclopentenyloxyethyl ester; (meth)acrylimide; Glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate; 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 other hydroxyl group-containing (meth)acrylate esters; Examples include (meth)acrylic acid esters containing substituted amino groups, such as N-methylaminoethyl (meth)acrylate. In this specification, "substituted amino group" means a group in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom. Among these, from the viewpoint of film-forming properties of the thermosetting resin film (x1) and the adherence of the thermosetting resin film (x1) to the protruding electrode forming surface, it is preferable that the alkyl group constituting the alkyl ester is a copolymer of (meth)acrylate alkyl ester having a chain structure with 1 to 18 carbon atoms, glycidyl group-containing (meth)acrylate ester, and hydroxyl group-containing (meth)acrylate ester; it is more preferable that the alkyl group constituting the alkyl ester is a copolymer of (meth)acrylate alkyl ester having a chain structure with 1 to 4 carbon atoms, glycidyl group-containing (meth)acrylate ester, and hydroxyl group-containing (meth)acrylate ester; and it is even more preferable that it is a copolymer of butyl acrylate, methyl acrylate, glycidyl acrylate, and 2-hydroxyethyl acrylate.

[0035] Acrylic resins may also be copolymerized with one or more monomers selected from, for example, (meth)acrylic acid esters, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide.

[0036] The monomers that make up the acrylic resin may be used individually or in combination of two or more. When the monomers that make up the acrylic resin are two or more, their combination and ratio can be arbitrarily selected.

[0037] -Polyarylate resin- Examples of the polyarylate resin in polymer component (A) include those that are well known. Examples of polyarylate resins include resins whose basic structure is the polycondensation of a divalent phenol with a dibasic acid such as phthalic acid or a carboxylic acid. Among these, polycondensates of bisphenol A and phthalic acid, poly-4,4'-isopropylidenediphenylene terephthalate / isophthalate copolymers, and their derivatives are preferred.

[0038] -Acetal resin- Examples of the polyacetal resin in polymer component (A) include those that are well known. Among these, preferred polyacetal resins include, for example, polyvinyl formal and polyvinyl butyral, with polyvinyl butyral being the most preferred. Examples of polyvinyl butyral include those having constituent units represented by the following formulas (i)-1, (i)-2, and (i)-3.

[0039] [ka]

[0040] (In the formula, l, m, and n are each an independent integer greater than or equal to 1.)

[0041] The weight-average molecular weight (Mw) of the polyvinyl acetal resin (preferably polyvinyl butyral) is preferably 5,000 to 200,000, more preferably 8,000 to 100,000, even more preferably 8,000 to 50,000, and even more preferably 10,000 to 35,000. Having a weight-average molecular weight of the polyvinyl acetal resin (preferably polyvinyl butyral) above the lower limit of the above-mentioned values ​​makes it easier to improve the shape stability (stable over time during storage) of the thermosetting resin film (x1). Furthermore, having a weight-average molecular weight of the polyvinyl acetal resin (preferably polyvinyl butyral) below the upper limit of the above-mentioned values ​​makes it easier for the thermosetting resin film (x1) to conform to the uneven surface of the adherend, for example, making it easier to suppress the generation of voids between the adherend and the thermosetting resin film (x1). Therefore, the coating properties on the surface where the protruding electrode is formed are improved, and the ability to embed into any irregularities that the material may have is also easily enhanced.

[0042] The glass transition temperature (Tg) of the polyvinyl acetal resin (preferably polyvinyl butyral) is preferably 40 to 80°C, and more preferably 50 to 70°C, from the viewpoint of film-forming properties of the thermosetting resin film (x1) and the protrusion of the tops of the protruding electrodes on the protruding electrode forming surface. Herein, in this specification, "the ability of the top of the protruding electrode to penetrate the thermosetting resin film (x1) when the thermosetting resin film (x1) is attached to the surface on which the protruding electrode is formed" refers to the ability of the top of the protruding electrode to penetrate the thermosetting resin film (x1), and is also referred to as "the ability of the top of the protruding electrode to penetrate".

[0043] The ratio of three or more monomers that make up the polyvinyl acetal resin (preferably polyvinyl butyral) can be arbitrarily selected.

[0044] In the thermosetting resin film (x1) and the thermosetting resin composition (x1-1), the content of polymer component (A) is preferably 2 to 30% by mass, more preferably 3 to 25% by mass, and even more preferably 3 to 15% by mass, based on the total amount of active ingredients.

[0045] Polymer component (A) may also correspond to thermosetting component (B). In this embodiment, if thermosetting resin composition (x1) and thermosetting resin composition (x1-1) contain components that correspond to both polymer component (A) and thermosetting component (B), thermosetting resin composition (x1) and thermosetting resin composition (x1-1) are considered to contain both polymer component (A) and thermosetting component (B).

[0046] (Thermosetting component (B)) The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) contain a thermosetting component (B). The thermosetting component (B) is a component that cures the thermosetting resin film (x1) to form a hard, cured resin film. The thermosetting component (B) may be used alone or in combination of two or more types. If there are two or more types of thermosetting component (B), their combination and ratio can be arbitrarily selected.

[0047] Examples of thermosetting component (B) include epoxy thermosetting resins, thermosetting polyimides, polyurethanes, unsaturated polyesters, and silicone resins. Among these, epoxy thermosetting resins are preferred. When thermosetting component (B) is an epoxy thermosetting resin, the protective properties of the cured resin film and the protrusion of the top of the protruding electrode are improved, and warping of the cured resin film can be suppressed.

[0048] Epoxy thermosetting resins consist of an epoxy resin (B1) and a thermosetting agent (B2). Epoxy thermosetting resins may be used individually or in combination of two or more types. When two or more epoxy thermosetting resins are used, their combination and ratio can be arbitrarily selected.

[0049] -Epoxy resin (B1)- While the epoxy resin (B1) is not particularly limited, it is preferable to use a combination of an epoxy resin that is solid at room temperature (hereinafter also referred to as a solid epoxy resin) and an epoxy resin that is liquid at room temperature (hereinafter also referred to as a liquid epoxy resin) from the viewpoint of making it easier to exhibit the effects of the present invention. Furthermore, from the viewpoint of making it easier to adjust the pre-curing loss tangent tanδ of the thermosetting resin film (x1) to the above range, it is preferable to use a flexible epoxy resin among liquid epoxy resins. In this specification, "room temperature" refers to 5 to 35°C, preferably 15 to 25°C.

[0050] The liquid epoxy resin is not particularly limited as long as it is liquid at room temperature. Examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, glycidyl ester type epoxy resin, biphenyl type epoxy resin, and phenylene skeleton type epoxy resin. Among these, bisphenol A type epoxy resin is preferred. Liquid epoxy resin may be used alone or in combination of two or more types. When two or more types of liquid epoxy resin are used, their combination and ratio can be arbitrarily selected.

[0051] The epoxy equivalent of the liquid epoxy resin is preferably 200 to 600 g / eq, more preferably 250 to 550 g / eq, and even more preferably 300 to 520 g / eq. The epoxy equivalent in this embodiment can be measured in accordance with JIS K 7236:2009.

[0052] As previously mentioned, it is preferable to use a flexible epoxy resin among liquid epoxy resins. In this embodiment, the term "flexible epoxy resin" refers to an epoxy resin into which a flexible skeleton has been introduced. Flexible skeletons in flexible epoxy resins include alkylene groups, alkenylene groups, alkylylene groups, polyoxyalkylene groups, polyoxyalkenylene groups, and polyoxyalkylene groups. The number of carbon atoms in the alkylene group, alkenylene group, and alkynylene group is preferably 1 to 30, more preferably 1 to 15, from the viewpoint of improving the stability of the flexible epoxy resin, facilitating the reduction of the glass transition temperature, and improving the embedding ability of the protruding electrode. Furthermore, the number of carbon atoms in the alkylene group, alkenylene group, and alkylylene group of the polyoxyalkylene group, polyoxyalkernylene group, and polyoxyalkylynylene group is preferably 2 to 4, more preferably 3, from the viewpoint of availability, improvement of the stability of the flexible epoxy resin, ease of reducing the glass transition temperature, and improvement of the embedding ability of the protruding electrode. Furthermore, from the viewpoint of easily adjusting the glass transition temperature (Tg) of the thermosetting resin film (x1) before curing to 40°C or lower, it is preferable that the flexible skeleton in the flexible epoxy resin does not have rigid bonds or skeletons, and it is particularly preferable that it does not have an aromatic ring skeleton. Furthermore, it is preferable that the flexible epoxy resin has the above-mentioned flexible skeleton introduced between the epoxy group and the bisphenol skeleton. More preferably, it is a flexible epoxy resin represented by the following general formula (2). EL 1 -BL 2 -E···(2) In the above general formula (2), E is an epoxy group. B is a bisphenol skeleton (for example, a divalent group obtained by removing a hydrogen atom from the hydroxyl group of bisphenol A). 1 and L 2 Each of these is an independent flexible skeleton as described above.

[0053] The solid epoxy resin is not particularly limited as long as it is solid at room temperature. Examples include biphenyl-type epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, orthocresol novolac epoxy resin, dicyclopentadiene-type epoxy resin, naphthalene-type epoxy resin, anthracene-type epoxy resin, and fluorene-based epoxy resin. Among these, naphthalene-type epoxy resin, dicyclopentadiene-type epoxy resin, and fluorene-based epoxy resin are preferred, and naphthalene-type epoxy resin and dicyclopentadiene-type epoxy resin are more preferred. Solid epoxy resins may be used individually or in combination of two or more types. If two or more types of solid epoxy resins are used, their combination and ratio can be arbitrarily selected.

[0054] The epoxy equivalent of the solid epoxy resin is preferably 150 to 450 g / eq, and more preferably 150 to 400 g / eq.

[0055] The ratio of liquid epoxy resin (xe) to solid epoxy resin (ye) [(xe) / (ye)] is preferably 0.01 to 10.0 by mass, more preferably 0.02 to 8.0, and even more preferably 0.03 to 6.0. When the above ratio [(xe) / (ye)] is within the above range, the effects of the present invention can be more easily improved.

[0056] The number-average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoint of the curability of the thermosetting resin film (x1) and the strength and heat resistance of the cured resin film after curing, it is preferably 300 to 30,000, more preferably 400 to 10,000, and even more preferably 500 to 3,000.

[0057] -Thermosetting agent (B2)- The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1). Examples of the thermosetting agent (B2) include compounds having two or more functional groups capable of reacting with epoxy groups in one molecule. Examples of the above functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups in which an acid group has been converted into an anhydride. It is preferable that the functional group is a phenolic hydroxyl group, an amino group, or a group in which an acid group has been converted into an anhydride, and it is more preferable that the functional group is a phenolic hydroxyl group or an amino group.

[0058] Examples of thermosetting agents (B2) that include phenolic curing agents having phenolic hydroxyl groups include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-based phenolic resins, and aralkylphenolic resins. Among the thermosetting agents (B2), examples of amine-based curing agents having an amino group include dicyandiamide (hereinafter sometimes abbreviated as "DICY"). Among these, phenolic curing agents having phenolic hydroxyl groups are preferred, and novolac-type phenolic resins are more preferred.

[0059] Among the thermosetting agents (B2), the number average molecular weight of the resin components, such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-based phenolic resins, and aralkylphenolic resins, is preferably 300 to 30,000, more preferably 400 to 10,000, and even more preferably 500 to 3,000. The molecular weight of the non-resin component of the thermosetting agent (B2), such as biphenol or dicyandiamide, is not particularly limited, but is preferably 60 to 500.

[0060] The thermosetting agent (B2) may be used alone or in combination of two or more types. If there are two or more types of thermosetting agent (B2), their combination and ratio can be arbitrarily selected.

[0061] In the thermosetting resin film (x1) and thermosetting resin composition (x1-1), the content of the thermosetting agent (B2) is preferably 0.010 to 200 parts by mass, more preferably 0.020 to 150 parts by mass, even more preferably 0.050 to 100 parts by mass, and even more preferably 0.10 to 77 parts by mass, based on 100 parts by mass of epoxy resin (B1). When the content of the thermosetting agent (B2) is above the lower limit, the curing of the thermosetting resin film (x1) proceeds more easily. Furthermore, when the content of the thermosetting agent (B2) is below the upper limit, the moisture absorption rate of the thermosetting resin film (x1) is reduced, and the reliability of the package obtained using the thermosetting resin film (x1) is further improved.

[0062] In the thermosetting resin film (x1) and thermosetting resin composition (x1-1), the content of the thermosetting component (B) (total content of epoxy resin (B1) and thermosetting agent (B2)) is preferably 200 to 10,000 parts by mass, more preferably 300 to 5,000 parts by mass, and even more preferably 400 to 1,000 parts by mass, per 100 parts by mass of the polymer component (A), from the viewpoint of enhancing the protective properties of the cured resin film.

[0063] -Curing accelerator (C)- The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may contain a curing accelerator (C). The curing accelerator (C) is an ingredient used to adjust the curing rate of the thermosetting resin film (x1). Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organophosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate. Among these, imidazoles are preferred, and 2-phenyl-4,5-dihydroxymethylimidazole is more preferred, from the viewpoint of making it easier to exhibit the effects of the present invention.

[0064] The curing accelerator (C) may be used alone or in combination of two or more types. If there are two or more types of curing accelerator (C), their combination and ratio can be arbitrarily selected.

[0065] In the thermosetting resin film (x1) and thermosetting resin composition (x1-1), when a curing accelerator (C) is used, the content of the curing accelerator (C) is preferably 0.001 to 10 parts by mass, and more preferably 0.01 to 5 parts by mass, per 100 parts by mass of the content of the thermosetting component (B). When the content of the curing accelerator (C) is above the lower limit, the effect of using the curing accelerator (C) is more easily obtained. Furthermore, when the content of the curing accelerator (C) is below the upper limit, for example, the effect of suppressing the migration and segregation of highly polar curing accelerators (C) to the adhesive interface side with the adherend in the thermosetting resin film (x1) under high temperature and high humidity conditions is enhanced, and the reliability of the package obtained using the thermosetting resin film (x1) is further improved.

[0066] -Filling material (D)- The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may contain a filler (D). By including a filler (D) and satisfying the above parameters, the chipping suppression of the cured resin film obtained by curing the thermosetting resin film (x) can be easily improved. Furthermore, by including the filler (D), it becomes easier to adjust the coefficient of thermal expansion of the cured resin film obtained by curing the thermosetting resin film (x) to an appropriate range, thereby further improving the reliability of the package obtained using the thermosetting resin film (x1). In addition, by including the filler (D) in the thermosetting resin film (x1), it is also possible to reduce the moisture absorption rate of the cured resin film and improve its heat dissipation.

[0067] The filler (D) may be either an organic filler or an inorganic filler, but it is preferably an inorganic filler or an organic / inorganic hybrid filler. Preferred inorganic fillers include, for example, powders such as silica, talc, calcium carbonate, and boron nitride; beads formed from these inorganic fillers in a spherical shape; surface modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; and glass fibers. Preferred organic / inorganic hybrid fillers include, for example, component-mixed fillers such as silica-acrylic composite particles (e.g., Soliostar manufactured by Nippon Shokubai); and composite fillers incorporating inorganic fine particles with organic materials. Among these, inorganic fillers are preferred, and among inorganic fillers, silica is preferred.

[0068] The filler (D) may be used alone or in combination of two or more types. If there are two or more types of filler (D), their combination and ratio can be selected arbitrarily.

[0069] In the thermosetting resin film (x1) and thermosetting resin composition (x1-1), when a filler (D) is used, the content of the filler (D) is preferably 5 to 50% by mass, more preferably 7 to 40% by mass, and even more preferably 10 to 30% by mass, based on the total amount of the active ingredient, from the viewpoint of suppressing the peeling of the cured resin film from the chip due to thermal expansion and thermal contraction.

[0070] The average particle size of the filler (D) is preferably 500 nm or less, more preferably 5 to 300 nm, and particularly preferably 10 to 100 nm. In this specification, the particle size of the filler (D) refers to the arithmetic mean particle size obtained by randomly selecting and measuring the particle sizes of multiple primary particles of the filler (D) observed with an electron microscope, and then calculating the average value of these measurements.

[0071] -Energy ray curable resin (E)- The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may contain an energy ray curable resin (E). The thermosetting resin film (x1) contains an energy-ray curable resin (E), allowing its properties to be altered by irradiation with energy rays.

[0072] Energy-ray curable resin (E) is obtained by polymerizing (curing) an energy-ray curable compound. Examples of energy-ray curable compounds include a polymer (e1) having energy-ray curable groups and a weight-average molecular weight of 80,000 to 2,000,000, and a compound (e2) having energy-ray curable groups and a molecular weight of 100 to 80,000. The polymer (e1) may be at least partially crosslinked with a crosslinking agent, or it may not be crosslinked.

[0073] (A polymer (e1) having energy-ray curable groups and a weight-average molecular weight of 80,000 to 2,000,000) Examples of polymers (e1) having energy ray curable groups and a weight-average molecular weight of 80,000 to 2,000,000 include acrylic resins (e1-1) formed by an addition reaction between an acrylic polymer (e11) having a functional group that can react with a group of another compound, and an energy ray curable compound (e12) having a group that reacts with the functional group and an energy ray curable group such as an energy ray curable double bond.

[0074] Examples of functional groups that can react with groups of other compounds include hydroxyl groups, carboxyl groups, amino groups, substituted amino groups (groups in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom), and epoxy groups. However, in terms of preventing corrosion of circuits such as semiconductor wafers and semiconductor chips, it is preferable that the functional group is a group other than a carboxyl group. Among these, the functional group is preferably a hydroxyl group.

[0075] • Acrylic polymer having functional groups (e11) Examples of the acrylic polymer (e11) having the functional group include those obtained by copolymerizing an acrylic monomer having the functional group with an acrylic monomer not having the functional group, and those obtained by copolymerizing monomers other than acrylic monomers (non-acrylic monomers) in addition to these monomers. Furthermore, the acrylic polymer (e11) may be a random copolymer or a block copolymer.

[0076] Examples of acrylic monomers having the aforementioned functional groups include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, substituted amino group-containing monomers, epoxy group-containing monomers, and the like.

[0077] Examples of the hydroxyl group-containing monomers 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. Examples include hydroxyalkyl (meth)acrylates, vinyl alcohol, allyl alcohol, and other non-(meth)acrylic unsaturated alcohols (unsaturated alcohols that do not have a (meth)acryloyl skeleton).

[0078] Examples of the carboxyl group-containing monomers 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 carboxyalkyl esters of (meth)acrylic acid such as 2-carboxyethyl methacrylate.

[0079] The acrylic monomer having the aforementioned functional group is preferably a hydroxyl group-containing monomer or a carboxyl group-containing monomer, and more preferably a hydroxyl group-containing monomer.

[0080] The acrylic polymer (e11) may consist of only one acrylic monomer having the functional group, or two or more monomers. If there are two or more monomers, their combination and ratio can be arbitrarily selected.

[0081] Examples of acrylic monomers that do not have the aforementioned functional groups 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. Examples of alkyl esters include isononyl, 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, octadecyl ((meth)acrylate) (stearyl (meth)acrylate), etc., in which the alkyl group constituting the alkyl ester has a chain structure with 1 to 18 carbon atoms.

[0082] Furthermore, examples of acrylic monomers that do not have the aforementioned functional groups include alkoxyalkyl group-containing (meth)acrylic acid esters such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate; aromatic group-containing (meth)acrylic acid esters such as aryl (meth)acrylate such as phenyl (meth)acrylate; non-crosslinked (meth)acrylamide and its derivatives; and non-crosslinked (meth)acrylic acid esters having a tertiary amino group such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.

[0083] The acrylic polymer (e11) may consist of only one acrylic monomer that does not have the functional group, or it may consist of two or more monomers. If there are two or more monomers, their combination and ratio can be arbitrarily selected.

[0084] Examples of the non-acrylic monomers include olefins such as ethylene and norbornene; vinyl acetate; and styrene. The non-acrylic monomers constituting the acrylic polymer (e11) may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0085] In the acrylic polymer (e11), the ratio (content) of the amount of constituent units derived from the functional group-containing acrylic monomer to the total amount of constituent units is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass, and particularly preferably 3 to 30% by mass. Having this ratio within this range allows the content of energy-ray-curable groups in the acrylic resin (e1-1) obtained by copolymerization of the acrylic polymer (e11) and the energy-ray-curable compound (e12) to easily adjust the degree of curing of the protective film within a preferred range.

[0086] The acrylic polymer (e11) constituting the acrylic resin (e1-1) may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0087] In the energy-ray curable resin (E), the content of the acrylic resin (e1-1) is preferably 1 to 40% by mass, more preferably 2 to 30% by mass, and particularly preferably 3 to 20% by mass.

[0088] • Energy ray curable compound (e12) The energy ray curable compound (e12) preferably has one or more groups selected from the group consisting of isocyanate groups, epoxy groups, and carboxyl groups as groups that can react with the functional groups of the acrylic polymer (e11), and more preferably has an isocyanate group as such. For example, if the energy ray curable compound (e12) has an isocyanate group as such, this isocyanate group readily reacts with the hydroxyl group of the acrylic polymer (e11) having a hydroxyl group as such as a functional group.

[0089] The energy ray curable compound (e12) preferably has 1 to 5 energy ray curable groups per molecule, and more preferably 1 to 2.

[0090] Examples of the energy-ray curable compound (e12) include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate; Acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth)acrylate; Examples include acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate. Among these, the energy ray curable compound (e12) is preferably 2-methacryloyloxyethyl isocyanate.

[0091] The energy ray curable compound (e12) constituting the acrylic resin (e1-1) may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0092] In the acrylic resin (e1-1), the ratio of the content of energy-ray-curable groups derived from the energy-ray-curable compound (e12) to the content of the functional groups derived from the acrylic polymer (e11) is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. Having the content within this range increases the adhesive strength of the protective film after curing. Note that if the energy-ray-curable compound (e12) is a monofunctional compound (having one of the groups in one molecule), the upper limit of the content ratio is 100 mol%, but if the energy-ray-curable compound (e12) 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%.

[0093] The weight-average molecular weight (Mw) of the polymer (e1) is preferably 100,000 to 2,000,000, and more preferably 300,000 to 1,500,000. Here, "weight-average molecular weight" is as explained earlier.

[0094] If the polymer (e1) is crosslinked with a crosslinking agent in at least a portion thereof, the polymer (e1) may be a monomer that does not fall under any of the above-described monomers that constitute the acrylic polymer (e11) and has a group that reacts with the crosslinking agent, which is polymerized and crosslinked at the group that reacts with the crosslinking agent, or it may be a group that reacts with the functional group derived from the energy ray curable compound (e12).

[0095] The polymer (e1) contained in the thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0096] (Compounds with energy-ray curable groups and a molecular weight of 100 to 80,000 (e2)) Examples of energy-ray curable groups in compound (e2) having an energy-ray curable group and a molecular weight of 100 to 80,000 include groups containing energy-ray curable double bonds, and preferred examples include (meth)acryloyl groups and vinyl groups.

[0097] The compound (e2) is not particularly limited as long as it satisfies the above conditions, but examples include low molecular weight compounds having energy ray curable groups, epoxy resins having energy ray curable groups, and phenolic resins having energy ray curable groups.

[0098] Among the compounds (e2) mentioned above, examples of low molecular weight compounds 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 compounds include 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol E 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, tricyclodecanedimethanol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and 1,4-butylene glycoside. Difunctional (meth)acrylates such as di(meth)acrylate, 1,6-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, 2-hydroxy-1,3-di(meth)acryloxypropane, and dicyclopentanyl di(meth)acrylate; 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, tetramethylolmethane tetra(meth)acrylate, ethoxylated pentaerythritol tetra( Polyfunctional (meth)acrylates such as meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol poly(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; Oligoester (meth)acrylate; urethane (meth)acrylate oligomer; epoxy-modified (meth)acrylate; polyether (meth)acrylate other than the above polyalkylene glycol (meth)acrylate; Examples include polyfunctional (meth)acrylate oligomers such as urethane (meth)acrylate oligomers; and itaconic acid oligomers.

[0099] Of the aforementioned compounds (e2), epoxy resins having energy-ray curable groups and phenolic resins having energy-ray curable groups also fall under the category of resins constituting thermosetting component (B), but in this invention they are treated as compounds (e2).

[0100] The compound (e2) preferably has a weight-average molecular weight of 100 to 30,000, and more preferably 300 to 10,000.

[0101] The compound (e2) contained in the thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0102] The energy-curable compounds used in polymerization may be used individually or in combination of two or more. When two or more energy-curable compounds are used in polymerization, their combination and ratio can be arbitrarily selected. For example, the polymer (e1) and the compound (e2) may be used individually or in combination.

[0103] In thermosetting resin films (x1) and thermosetting resin compositions (x1-1), when an energy-ray curable resin (E) is used, the content of the energy-ray curable resin (E) is preferably 1 to 95% by mass, more preferably 5 to 90% by mass, and even more preferably 10 to 85% by mass, based on the total amount of active ingredients in the thermosetting resin composition (x1-1). -Photopolymerization initiator (F)- If the thermosetting resin film (x1) and thermosetting resin composition (x1-1) contain an energy ray curable resin (E), the thermosetting resin film (x1) and thermosetting resin composition (x1-1) may contain a photopolymerization initiator (F) in order to efficiently advance the polymerization reaction of the energy ray curable resin (E).

[0104] Examples of photopolymerization initiators (F) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, 1,2-diphenylmethane, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 2-chloroanthraquinone.

[0105] The photopolymerization initiator (F) may be used alone or in combination of two or more types. If there are two or more photopolymerization initiators (F), their combination and ratio can be arbitrarily selected.

[0106] In the thermosetting resin film (x1) and thermosetting resin composition (x1-1), when a photopolymerization initiator (F) is used, the content of the photopolymerization initiator (F) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass, based on 100 parts by mass of the energy ray curable resin (E).

[0107] -Additive (G)- The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may contain additive (G) as long as it does not impair the effects of the present invention. Additive (G) may be any known additive and can be arbitrarily selected depending on the purpose, and is not particularly limited. Preferred additives (G) include, for example, rheology control agents, coupling agents, crosslinking agents, surfactants, plasticizers, antistatic agents, antioxidants, leveling agents, gettering agents, and silicone oils.

[0108] Additive (G) may be used alone or in combination of two or more types. If there are two or more types of additive (G), their combination and ratio can be arbitrarily selected. The amount of additive (G) is not particularly limited and should be selected as appropriate depending on the purpose.

[0109] -solvent- The thermosetting resin composition (x1-1) preferably further contains a solvent. A thermosetting resin composition (x1-1) containing a solvent has good handling properties. The solvent is not particularly limited, but preferred solvents include, for example, 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 may be used alone or in combination of two or more types. If two or more solvents are used, their combination and ratio can be arbitrarily selected. The solvent is preferably methyl ethyl ketone or the like, as it allows for more uniform mixing of the components contained in the thermosetting resin composition (x1-1).

[0110] -Method for preparing a thermosetting resin composition (x1-1)- A thermosetting resin composition (x1-1) is prepared by blending the components that make it up. The order in which each component is added during formulation is not particularly limited, and two or more components may be added simultaneously. When using a solvent, the solvent may be used after pre-diluting the formulation by mixing it with any of the other components, or the solvent may be used by mixing it with the other components without pre-diluting them. The method of mixing each component during formulation is not particularly limited; it can be appropriately selected from known methods such as mixing by rotating a stirring bar or impeller, mixing using a mixer, or mixing by applying ultrasonic waves. The temperature and time during the addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and can be adjusted as appropriate, but a temperature of 15 to 30°C is preferred.

[0111] (Energy-ray curable resin film (x2)) The energy ray-curable resin film (x2) contains an energy ray-curable component (α). The energy ray-curable resin film (x2) is formed from, for example, an energy ray-curable resin composition (x2-1) containing an energy ray-curable component (α). The energy ray curable component (α) is preferably uncured, more preferably tacky, and even more preferably both uncured and tacky. In this specification, the following description of "the content of each component on a total basis of the active ingredients of the energy ray-curable resin composition (x2-1)" is synonymous with "the content of each component of the energy ray-curable resin film (x2) formed from the energy ray-curable resin composition (x2-1)".

[0112] -Energy ray curing component (α)- The energy ray curable component (α) is a component that hardens upon irradiation with energy rays, and is also a component that imparts film-forming properties and flexibility to the energy ray curable resin film (x2). Examples of the energy-ray curable component (α) include a polymer (α1) having an energy-ray curable group and a weight-average molecular weight of 80,000 to 2,000,000, and a compound (α2) having an energy-ray curable group and a molecular weight of 100 to 80,000. The polymer (α1) may be at least partially crosslinked with a crosslinking agent, or it may not be crosslinked.

[0113] Furthermore, the polymer (α1) and compound (α2) in the energy-ray curable resin composition (x2-1) are the same as the polymer (e1) and compound (e2) in the thermosetting resin composition (x1-1), and their preferred embodiments are also the same as those of the polymer (e1) and compound (e2) in the thermosetting resin composition (x1-1).

[0114] - A polymer (β) that does not have energy-ray curable groups - When the energy-ray curable resin composition (x2-1) and the energy-ray curable resin film (x2) contain compound (α2) as the energy-ray curable component (α), it is preferable that they also contain a polymer (β) that does not have an energy-ray curable group. The polymer (β) that does not have energy-ray curable groups may be crosslinked with a crosslinking agent in at least a portion of it, or it may not be crosslinked.

[0115] Examples of polymers (β) that do not have energy-ray curable groups include acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber resins, acrylic urethane resins, and polyvinyl acetals. Among these, polymers (β) are preferably acrylic polymers (hereinafter sometimes abbreviated as "acrylic polymer (β-1)") and polyvinyl acetals.

[0116] The acrylic polymer (β-1) may be any known polymer, for example, a homopolymer of one acrylic monomer, or a copolymer of two or more acrylic monomers. Alternatively, the acrylic polymer (β-1) may be a copolymer of one or more acrylic monomers and one or more monomers other than acrylic monomers (non-acrylic monomers).

[0117] Examples of the acrylic monomers constituting the acrylic polymer (β-1) include alkyl (meth)acrylates, (meth)acrylates having a cyclic skeleton, glycidyl group-containing (meth)acrylates, hydroxyl group-containing (meth)acrylates, and substituted amino group-containing (meth)acrylates.

[0118] Examples of alkyl (meth)acrylates 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 isono(meth)acrylate. Examples of alkyl esters include (meth)acrylates such as nyl, 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), in which the alkyl group constituting the alkyl ester has a chain structure with 1 to 18 carbon atoms.

[0119] Examples of (meth)acrylic acid esters having a cyclic skeleton include cycloalkyl (meth)acrylate esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; aralkyl (meth)acrylate esters such as benzyl (meth)acrylate; cycloalkenyl (meth)acrylate esters such as dicyclopentenyl (meth)acrylate; and cycloalkenyloxyalkyl (meth)acrylate esters such as dicyclopentenyloxyethyl (meth)acrylate.

[0120] Examples of glycidyl group-containing (meth)acrylic acid esters include glycidyl (meth)acrylate. Examples of hydroxyl group-containing (meth)acrylic acid esters 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. Examples of the substituted amino group-containing (meth)acrylic acid ester include N-methylaminoethyl (meth)acrylic acid.

[0121] Examples of non-acrylic monomers that constitute the acrylic polymer (β-1) include olefins such as ethylene and norbornene; vinyl acetate; and styrene.

[0122] As for the polyvinyl acetal, as explained in the section on polymer component (A), polyvinyl formal and polyvinyl butyral are preferred, with polyvinyl butyral being more preferred. Furthermore, as for the polyvinyl butyral, those having the constituent units represented by the above formulas (i)-1, (i)-2, and (i)-3 are preferred. The preferred embodiments of polyvinyl butyral are as described in polymer component (A), and the explanation is omitted.

[0123] Examples of polymers (β) that do not have energy-ray curable groups and are crosslinked by a crosslinking agent include polymers (β) in which reactive functional groups react with the crosslinking agent. The reactive functional group can be appropriately selected depending on the type of crosslinking agent, etc., and is not particularly limited. For example, when the crosslinking agent is a polyisocyanate compound, the reactive functional group can be a hydroxyl group, a carboxyl group, or an amino group, and among these, the hydroxyl group, which has high reactivity with the isocyanate group, is preferred. Furthermore, when the crosslinking agent is an epoxy compound, the reactive functional group can be a carboxyl group, an amino group, or an amide group, and among these, the carboxyl group, which has high reactivity with epoxy groups, is preferred. However, in terms of preventing corrosion of semiconductor wafers and semiconductor chip circuits, it is preferable that the reactive functional group is a group other than a carboxyl group.

[0124] Examples of polymers (β) having reactive functional groups but not energy-ray curable groups include those obtained by polymerizing monomers having at least reactive functional groups. In the case of acrylic polymers (β-1), either or both of the acrylic and non-acrylic monomers listed as constituent monomers may have reactive functional groups. For example, an example of a polymer (β) having a hydroxyl group as a reactive functional group is one obtained by polymerizing a hydroxyl group-containing (meth)acrylic acid ester. In addition, polymers obtained by polymerizing monomers in which one or more hydrogen atoms are substituted with the reactive functional group in the aforementioned acrylic or non-acrylic monomers may also be used.

[0125] In a polymer (β) having a reactive functional group, the ratio (content) of the amount of constituent units derived from the monomer having a reactive functional group to the total mass of the constituent units is preferably 1 to 20% by mass, and more preferably 2 to 10% by mass. When the ratio is within this range, the degree of crosslinking in polymer (β) is within a more preferable range.

[0126] The weight-average molecular weight (Mw) of the polymer (β) that does not have energy-ray curable groups is preferably 10,000 to 2,000,000, and more preferably 20,000 to 1,500,000, from the viewpoint that the film-forming properties of the energy-ray curable resin composition (x2-1) will be better.

[0127] The polymer (β) that does not have energy-ray curable groups may be used alone or in combination of two or more types. When there are two or more polymers (β) that do not have energy-ray curable groups, their combination and ratio can be arbitrarily selected.

[0128] Examples of energy-ray curable resin compositions (x2-1) include those containing either or both of the polymer (α1) and the compound (α2). Furthermore, if the energy-ray curable resin composition (x2-1) contains compound (α2), it is preferable that it also contains a polymer (β) that does not have an energy-ray curable group, and in this case, it is also preferable that it contains polymer (α1). Furthermore, the energy-ray curable resin composition (x2-1) may not contain compound (α2) and may contain both polymer (α1) and polymer (β) that does not have an energy-ray curable group.

[0129] When the energy-ray curable resin composition (x2-1) contains a polymer (α1), a compound (α2), and a polymer (β) that does not have an energy-ray curable group, the content of compound (α2) is preferably 10 to 400 parts by mass, and more preferably 30 to 350 parts by mass, based on 100 parts by mass of the total content of polymer (α1) and polymer (β) that does not have an energy-ray curable group.

[0130] The total content of the energy ray-curable component (α) and the polymer (β) without energy ray-curable groups is preferably 5 to 90% by mass, more preferably 10 to 80% by mass, and even more preferably 20 to 70% by mass, based on the total amount of active ingredients in the energy ray-curable resin composition (x2-1). Having the energy ray-curable component content within this range results in better energy ray curability of the energy ray-curable resin film (x2).

[0131] The energy-ray curable resin composition (x2-1) may contain, in addition to the energy-ray curable component, one or more components selected from the group consisting of thermosetting components, photopolymerization initiators, fillers, coupling agents, crosslinking agents, and additives, depending on the purpose. For example, by using an energy-ray curable resin composition (x2-1) containing an energy-ray curable component and a thermosetting component, the energy-ray curable resin film (x2) formed has improved adhesion to the adherend upon heating, and the strength of the cured resin film formed from this energy-ray curable resin film (x2) is also improved.

[0132] The thermosetting component, photopolymerization initiator, and additive in the energy ray curable resin composition (x2-1) are the same as those in the thermosetting component (B), photopolymerization initiator (F), filler (D), and additive (G) in the thermosetting resin composition (x1-1), respectively.

[0133] In the energy-ray curable resin composition (x2-1), the thermosetting component, photopolymerization initiator, filler, and additive may each be used individually or in combination of two or more. When two or more are used in combination, the combination and ratio can be arbitrarily selected. The content of thermosetting components, photopolymerization initiators, fillers, and additives in the energy ray curable resin composition (x2-1) can be adjusted as appropriate depending on the purpose, and is not particularly limited.

[0134] The energy-ray curable resin composition (x2-1) is preferable to further contain a solvent, as its handling properties are improved by dilution. Examples of solvents contained in the energy-ray-curable resin composition (x2-1) include the same solvent as that in the thermosetting resin composition (x1-1). The solvent contained in the energy-ray curable resin composition (x2-1) may be used alone or in combination of two or more types. When using two or more types in combination, the combination and ratio can be arbitrarily selected.

[0135] -Other ingredients- The energy-ray curable resin composition (x2-1) may contain, in addition to the energy-ray curable component described above, appropriate amounts of components other than the curable component, namely curing accelerators (C), fillers (D), additives (G), etc., similar to the case of the thermosetting resin film (x1) described earlier.

[0136] -Method for preparing an energy-curable resin composition (x2-1)- The energy-ray curable resin composition (x2-1) is obtained by blending the components that constitute it. The order in which the components are added is not particularly limited, and two or more components may be added simultaneously. When using a solvent, the solvent may be used after pre-diluting the mixture by mixing it with any other component, or the solvent may be used by mixing it with the other components without pre-diluting them. The method of mixing each component during formulation is not particularly limited, and any known method may be appropriately selected, such as mixing by rotating a stirring bar or impeller; mixing using a mixer; or mixing by applying ultrasound. The temperature and time during the addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and can be adjusted as appropriate, but a temperature of 15 to 30°C is preferred.

[0137] (Preparation of a curable resin film (x)) The curable resin film (x) can be manufactured, for example, by coating the surface to be formed with a curable resin composition such as the thermosetting resin composition (x1-1) or the energy ray curable resin composition (x2-1) of this embodiment (hereinafter also referred to as curable resin composition (x-1)), and drying it as necessary. The curable resin composition (x-1) can be applied by known methods, such as using various coaters including an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, Meyer bar coater, and kiss coater. The drying conditions after applying the curable resin composition (x-1) are not particularly limited, but for example, the drying temperature can be set to 70 to 130°C and the drying time to 10 seconds to 5 minutes.

[0138] <Base material> In this embodiment, the base material includes a core material layer and a flexible material layer. The flexible material layer is provided on at least one side of the core material layer. Therefore, the flexible material layer may be provided on only one side of the core material layer, or on both sides of the core material layer. Alternatively, the structure may consist of a flexible material layer provided on at least one side of the core material layer, with multiple flexible material layers and multiple core material layers arranged alternately.

[0139] The thickness of the substrate is not particularly limited, but is preferably 50 to 600 μm, more preferably 75 to 500 μm, and even more preferably 100 to 400 μm. Furthermore, the thickness of the substrate may be selected considering the height of the protruding electrode, for example, it may be 50 to 200 μm, 50 to 150 μm, or 50 to 120 μm.

[0140] The core material layer and soft material layer constituting the base material may contain various known additives other than the main constituent materials, such as fillers, colorants, antioxidants, organic lubricants, catalysts, and softeners (plasticizers).

[0141] The core material layer and soft material layer constituting the base material may be transparent or opaque, may be colored according to the purpose, or other layers may be deposited on other surfaces that do not come into contact with the protective film. Furthermore, if the protective film-forming film is energy ray curable, it is preferable that the substrate be light-transmitting.

[0142] The core material layer and the soft material layer will be explained in detail below.

[0143] (Core layer) In this embodiment, the core material layer is required to have a load deflection temperature (T1) that is higher than the application temperature when the composite sheet for forming the protective film is applied to the protruding electrode forming surface of the member with the protruding electrode. For example, if the application temperature is 80°C, the load deflection temperature (T1) of the core material layer must be higher than 80°C. By having a load deflection temperature (T1) of the core material layer that is higher than the bonding temperature, the rigidity of the substrate is ensured even in the bonding temperature range, making it easier to transmit the pressing force during bonding to the surface where the protruding electrodes are formed. Furthermore, the load deflection temperature (T1) of the core material layer is preferably 50°C or higher, and more preferably 80°C or higher.

[0144] From the viewpoint of improving the effects of the present invention, the thickness of the core material layer is preferably 10 to 150 μm, more preferably 20 to 100 μm, and even more preferably 50 to 80 μm.

[0145] Examples of resin compositions that can constitute the core material layer include polystyrene; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and all aromatic polyesters in which all constituent units are aromatic cyclic groups; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethanes; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxide; polyphenylene sulfide; polysulfones; polyether ketones; polymer alloys such as mixtures of the above polyesters and other resins; crosslinked resins in which one or more of the above resins are crosslinked; and modified resins such as ionomers using one or more of the above resins. Among these, polyester is preferred, and polyethylene terephthalate is more preferred. In other words, the core material layer is preferably a polyethylene terephthalate resin layer. Furthermore, the resin constituting the core material layer may be a single type used alone, or two or more types may be used in combination.

[0146] (Soft material layer) In this embodiment, the soft material layer is required to have a load deflection temperature (T2) lower than the application temperature when the composite sheet for forming the protective film is applied to the protruding electrode forming surface of the member with the protruding electrode. For example, if the application temperature is 80°C, the glass transition temperature (Tg2) of the soft material layer must be lower than 80°C. By keeping the soft material layer at a temperature below the application temperature, the soft material layer exhibits flexibility within the application temperature range, making it easier to achieve good conformability to the uneven surface of the protruding electrode formation surface. Furthermore, the load deflection temperature (T2) of the core material layer is preferably 90°C or lower, and more preferably 80°C or lower.

[0147] From the viewpoint of improving the effects of the present invention, the thickness of the soft material layer is preferably 5 to 100 μm, more preferably 10 to 75 μm, and even more preferably 15 to 50 μm. Furthermore, the thickness of the soft material layer may be 40 μm or less, or 30 μm or less.

[0148] Examples of resins that constitute the flexible material layer include polyolefin resins and urethane resins. Specifically, polyolefin resins include polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); and polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resins. The resin constituting the soft material layer may be used alone or in combination of two or more types.

[0149] Furthermore, the substrate containing the core material layer and the flexible material layer can be manufactured by known methods. For example, a substrate containing resin can be manufactured by molding a resin composition containing the above-mentioned resin.

[0150] <Structure of a composite sheet> The composite sheet for forming a protective film in this embodiment (hereinafter also simply referred to as the "composite sheet") is a sheet in which a protective film and a substrate are laminated together. The following describes the first and second embodiments of the composite sheet according to this embodiment. However, the composite sheet according to this embodiment is not limited to the first and second embodiments. For example, the first and second embodiments may have other layers, as long as they do not significantly impair the effects of the present invention.

[0151] (First aspect) Figure 1 shows a first embodiment of the composite sheet of this embodiment. The composite sheet 1 shown in Figure 1 comprises a base material 10 and a protective film 13. The base material 10 has a core material layer 11 with soft material layers 12 on both sides, and one of the soft material layers 12 is in direct contact with the protective film 13. Although not shown in the illustration, a release film or the like may be provided on the side of the protective film-forming film 13 opposite to the substrate 10.

[0152] (Second aspect) A second embodiment of the composite sheet of this embodiment is shown in Figure 2. The composite sheet 1a shown in Figure 2 comprises a base material 10 and a protective film 13. The base material 10 has a soft material layer 12 on one side of the core material layer 11, and the soft material layer 12 is in direct contact with the protective film forming film 13. Although not shown in the illustration, a release film or the like may be provided on the side of the protective film-forming film 13 opposite to the substrate 10.

[0153] (Method of manufacturing composite sheets) The composite sheet of this embodiment can be manufactured by sequentially stacking the above-mentioned layers in corresponding positional relationships. For example, the curable resin composition (x-1) of this embodiment is applied to the release surface of a release film, and dried as necessary to form a curable resin film (x) on the release film as a protective film-forming film. Next, the side of the substrate facing the flexible material layer and the exposed side of the curable resin film (x) opposite to the release film are bonded together. This results in a composite sheet having a laminated structure of the substrate and the curable resin film (x), in which the flexible material layer of the substrate and the curable resin film (x) are in direct contact. The release film provided on the curable resin film (x) in the composite sheet can be removed at any stage between the time of manufacture of the composite sheet and the time of use. Furthermore, a composite sheet having a laminated structure of a substrate and a curable resin film (x), in which the flexible material layer of the substrate and the curable resin film (x) are in direct contact, can also be manufactured by coating the flexible material layer side of the substrate with a curable resin composition (x-1) and drying it as necessary.

[0154] A composite sheet comprising layers other than those described above can be manufactured by adding or omitting steps as appropriate in the manufacturing method described above, so that the stacking positions of each layer are at desired positions.

[0155] <Physical properties of composite sheets> The composite sheet for forming a protective film in this embodiment satisfies the following physical properties.

[0156] (Peeling force) The composite sheet for forming a protective film in this embodiment is required to have a peeling force greater than 40 mN / 100 mm and less than 3,000 mN / 100 mm when peeling the substrate from the protective film. Within the aforementioned range of peeling force, the protective film-forming film exhibits excellent retention during distribution, storage, and application to the surface where protruding electrodes are formed. Furthermore, after application to the surface, only the protective film-forming film remains, making it easy to remove other laminates. Therefore, a composite sheet for forming a protective film can be produced that offers excellent handling properties. Here, from the viewpoint of further improving handling, the peeling force is preferably 60 mN / 100 mm to 2,800 mN / 100 mm, more preferably 80 mN / 100 mm to 2,600 mN / 100 mm, and even more preferably 100 mN / 100 mm to 2,000 mN / 100 mm. In this embodiment, the peeling force refers to the peeling force measured by the method described in the examples later.

[0157] (Self-adhesion) The composite sheet for forming a protective film in this embodiment is prepared by preparing two substrates, overlapping the two substrates so that the soft material layers are in contact with each other, and then heat laminating them. The peeling force when peeling them off is 3,000 mN / 25 mm or less. This makes it possible to reduce the self-adhesion of the soft material layer of the substrate. From the viewpoint of making it easier to reduce self-adhesion, the above peeling force is preferably 2,400 mN / 25 mm or less, more preferably 2,000 mN / 25 mm, and even more preferably 1,000 mN / 25 mm or less. By reducing the self-adhesion properties of the soft material layer of the substrate, the peeling force required when peeling the substrate from the protective film can be significantly reduced.

[0158] [Method for manufacturing a semiconductor device according to the first embodiment] A first embodiment of this invention provides a method for manufacturing a semiconductor device, which includes the step of forming a protective film on the protruding electrode surface of a member with protruding electrodes using a protective film-forming composite sheet. Here, taking the case where the member with the protruding electrode is a semiconductor wafer with bumps as an example, the manufacturing method of the semiconductor device according to the first aspect of this embodiment is preferably a manufacturing method that includes the following steps 1 to 5. Step 1: The step of attaching the protective film-forming film of the protective film-forming composite sheet of this embodiment to the protruding electrode-forming surface of a semiconductor wafer, thereby laminating the protective film-forming composite sheet onto the semiconductor wafer (hereinafter also referred to as the "attachment step"). Step 2: The process of removing the substrate from the composite sheet for forming the protective film that was laminated in Step 1 (hereinafter also referred to as the "removal step"). Step 3: A step to form a protective film by curing a protective film-forming film on a semiconductor wafer (hereinafter also referred to as the "curing step"). Step 4: A step to manufacture semiconductor chips by dividing the semiconductor wafer after Step 3 (hereinafter also referred to as the "dividing step"), and a step to cut the protective film after Step 3 (hereinafter also referred to as the "cutting step"). Step 5: The process of mounting the semiconductor chip with a protective film onto the substrate using a flip-chip connection (hereinafter also referred to as the "mounting process"). The following explains each process with reference to the diagrams. In Figures 3 to 6, the protective film 13 is synonymous with the curable resin film (x). Furthermore, while Figures 3 to 6 illustrate an embodiment using the composite sheet for forming a protective film shown in Figure 1, the method for manufacturing a semiconductor device according to the first embodiment of this embodiment is not limited to this embodiment, and composite sheets with other configurations may also be used.

[0159] <Process 1: Pasting Process> Figure 3 is a schematic cross-sectional view illustrating the application process. Figures 3(a) and (b) show the process of attaching the protective film-forming composite sheet 1 to the protruding electrode-forming surface 20a of the semiconductor wafer 20. In the bonding process, for example, first, as shown in Figure 3(a), the composite sheet 1 for forming the protective film is positioned so that the protective film 13 faces the protruding electrode formation surface 20a of the semiconductor wafer 20. Next, as shown in Figure 3(b), the protective film-forming film 13 is brought into contact with the protruding electrode 21 on the semiconductor wafer 20, and the protective film-forming composite sheet 1 is pressed against the semiconductor wafer 20. By pressing, the protective film-forming film 13 is sequentially pressed onto the surface of the protruding electrode 21 and the protruding electrode-forming surface 20a of the semiconductor wafer 20.

[0160] The height of the protruding electrode 21 may be 10 to 400 μm, 15 to 150 μm, or 20 to 50 μm. In this specification, "height of the protruding electrode" means the height of the portion of the protruding electrode that is located at the highest position from the surface on which the protruding electrode is formed. The width of the protruding electrode 21 may be 10 to 400 μm, 15 to 150 μm, or 20 to 50 μm. In this specification, "width of the protruding electrode" means the maximum length of a line segment obtained by drawing a straight line between two different points on the surface of the protruding electrode when the protruding electrode is viewed from above in a plan view from a direction perpendicular to the surface on which the protruding electrode is formed. The distance between adjacent protruding electrodes 21 is not particularly limited, but may be 10 to 400 μm, 15 to 150 μm, or 20 to 50 μm. In this specification, "distance between adjacent protruding electrodes" means the minimum distance between the surfaces of adjacent protruding electrodes.

[0161] As a method for pressing the protective film-forming composite sheet 1 onto the semiconductor wafer 20, known methods for pressing and attaching various sheets to an object can be applied, such as using a roller-type laminator. The heating temperature when pressing the protective film-forming composite sheet 1 onto the semiconductor wafer 20 is not particularly limited and may be, for example, 50 to 90°C, and preferably 70 to 85°C. The pressure applied when pressing the protective film-forming composite sheet 1 onto the semiconductor wafer 20 is not particularly limited and may be, for example, 0.1 to 1.5 MPa, and preferably 0.2 to 1 MPa. The speed at which the protective film-forming composite sheet 1 is attached to the semiconductor wafer 20 is not particularly limited, but is usually around 3 mm / s. Furthermore, the method for pressing the protective film-forming composite sheet 1 onto the semiconductor wafer 20 is not limited to using a roller-type laminator; for example, a method using a vacuum laminator may also be employed.

[0162] After the bonding process, the side of the semiconductor wafer 20 opposite to the protruding electrode formation surface 20a (the back side) may be ground as needed, and further, another protective film-forming composite sheet (not shown) may be attached to the back side after grinding.

[0163] <Step 2: Removal step> Figure 4 is a schematic cross-sectional view illustrating the removal process. After the bonding process, the protective film-forming composite sheet 1 is cut along the shape of the semiconductor wafer 20. The protective film-forming composite sheet 1 of this embodiment has excellent cutability, so it can be cut well along the shape of the semiconductor wafer 20 without wrinkles or distortions during cutting. Then, as shown in Figure 4, the substrate 10 is peeled off from the protective film-forming composite sheet 1 to obtain a semiconductor wafer 30 with a protective film-forming film, which comprises the semiconductor wafer 20 and the protective film-forming film 13 provided on the protruding electrode-forming surface 20a of the semiconductor wafer 20. The protective film-forming composite sheet 1 of this embodiment has excellent peelability when peeling the substrate 10 from the protective film-forming composite sheet 1, making it easy to remove the substrate 10. The substrate 10 can be removed by known methods.

[0164] <Process 3: Curing process> Figure 5 is a schematic cross-sectional view illustrating the curing process. After the removal process, as shown in Figure 5, the protective film-forming film 13 is cured to form a protective film 13' on the bump-forming surface 20a of the semiconductor wafer 20. This results in a semiconductor wafer 40 with a protective film 13' on the protruding electrode-forming surface 20a of the semiconductor wafer 20. The protective film 13 can be cured by either thermal curing or curing by irradiation with energy rays, depending on the type of curable component contained in the protective film 13. When performing thermal curing, the curing temperature is preferably 90°C to 200°C (more preferably 110°C to 170°C, and even more preferably 120°C to 140°C), and the curing time is preferably 1 hour to 5 hours. The conditions for curing by energy ray irradiation are set appropriately depending on the type of energy ray used. For example, when using ultraviolet light, the illuminance is preferably 170 mw / cm². 2 ~250mw / cm 2 The light intensity is preferably 300 mJ / cm². 2 ~3,000 mJ / cm 2 That is the case.

[0165] <Process 4: Splitting process, cutting process> Figure 6 is a schematic cross-sectional view illustrating the dividing and cutting processes. After the curing process, as shown in Figure 6, the semiconductor wafer 20 is divided in the splitting process, and the protective film 13' is cut. This results in a semiconductor chip 60 with a protective film, which has the cut protective film 13' on the bump-forming surface of the semiconductor chip.

[0166] The dividing and cutting processes can be carried out by known methods. The order in which the dividing and cutting processes are performed is not particularly limited, but it is preferable to perform the dividing and cutting processes simultaneously or in that order. When the dividing and cutting processes are performed in this order, for example, the dividing process may be performed by a known dicing method, and then the cutting process may be performed immediately afterward. Dicing can be performed by providing a dicing sheet (not shown) on the back surface of the semiconductor wafer 20 (which may be the back surface after grinding). In the cutting process, the protective film 13' is cut along the planned or already divided portion of the semiconductor wafer 20 (in other words, the outer periphery of the semiconductor chip 40).

[0167] <Process 5: Assembly Process> In the mounting process, the semiconductor chip 60 with the protective film obtained in the curing process is flip-chip connected to the substrate at the top of the film 21 (not shown). At this time, the semiconductor chip 60 with the protective film is connected to the circuit formation surface of the substrate. If a large amount of protective film covers the top of the electrode, the protective film on the top is removed as appropriate before connection. The protective film can be removed, for example, by plasma treatment or laser irradiation. Subsequently, using the circuit board with the semiconductor chip already mounted, obtained in this manner, a semiconductor package can be fabricated according to a known method, and the desired semiconductor device can be manufactured using this semiconductor package.

[0168] [Method for manufacturing semiconductor manufacturing apparatus according to the second embodiment] A second embodiment of this invention relates to a method for manufacturing a semiconductor device, wherein the member with the protruding electrode is a semiconductor wafer having a protruding electrode forming surface equipped with the protruding electrode, and includes the following steps (S1) to (S4): • Step (S1): A step of preparing a semiconductor wafer for semiconductor chip fabrication in which grooves, which are intended to be divided lines, are formed on the protruding electrode formation surface of the semiconductor wafer without reaching the back surface. Step (S2): A step in which the protective film-forming film of the protective film-forming composite sheet is attached to the protruding electrode-forming surface of the semiconductor chip manufacturing wafer, covering the protruding electrode-forming surface of the semiconductor chip manufacturing wafer with the protective film-forming film, and embedding the protective film-forming film into the grooves formed in the semiconductor chip manufacturing wafer. • Step (S3): A step to cure the protective film-forming film to obtain a wafer for manufacturing semiconductor chips with a protective film. • Step (S4): A step in which the wafer for fabricating the semiconductor chip with the protective film is divided into individual pieces along the planned division line to obtain a semiconductor chip in which at least the surface where the protruding electrodes are formed and the sides are covered with the protective film. Furthermore, the following step (S-BG) is included after step (S2) and before step (S3), after step (S3) and before step (S4), or during step (S4). • Process (S-BG): A process for grinding the back surface of the semiconductor chip manufacturing wafer. The following explains each step with reference to the diagrams. Note that while Figures 8 and 11 omit the detailed configuration of the substrate, the substrate configuration may be as shown in Figure 1 or as shown in Figure 2. Furthermore, although bumps will be used as an example of protruding electrodes in the following explanation, other types of protruding electrodes may, of course, be used in this invention.

[0169] <Process (S1)> A schematic cross-sectional view of an example of a semiconductor wafer prepared in process (S1) is shown in Figure 7. In step (S1), a semiconductor wafer 70 for semiconductor chip fabrication is prepared, in which grooves 23, which are intended to be divided lines, are formed on the bump-forming surface 20a of a semiconductor wafer 20 having bumps 21, without reaching the back surface 20b.

[0170] The shape of the bump 21 is not particularly limited and can be any shape as long as it can be in contact with and fixed to electrodes on the substrate for chip mounting. For example, in Figure 7, the bump 21 is spherical, but the bump 21 may be a spheroid. This spheroid may be, for example, a spheroid stretched perpendicularly to the bump-forming surface 20a of the wafer 20, or a spheroid stretched horizontally to the bump-forming surface 20a of the wafer 20. The bump 21 may also be pillar-shaped.

[0171] The height of the bump 21, the width of the bump 21, and the distance between adjacent bumps 21 are not particularly limited, but examples include the height of the bump 21, the width of the bump 21, and the distance between adjacent bumps 21 as described in the first embodiment of the semiconductor device manufacturing method.

[0172] The type, size, and thickness of the wafer 20 are not particularly limited, but examples include the semiconductor wafers listed in the semiconductor device manufacturing method of the first embodiment.

[0173] In step (S1), a plurality of grooves 23 are formed in a grid pattern on the bump-forming surface 20a of the semiconductor chip manufacturing wafer 70, which is prepared as the planned division lines when the semiconductor chip manufacturing wafer 70 is divided into individual pieces. The plurality of grooves 23 are notches formed when the blade-first dicing method (Dicing Before Grinding) is applied, and are formed to a depth shallower than the thickness of the wafer 20, so that the deepest part of the groove 23 does not reach the back surface 20b of the wafer 20. The plurality of grooves 23 can be formed by dicing using a conventionally known wafer dicing apparatus equipped with a dicing blade. The multiple grooves 23 should be formed so that the semiconductor chip to be manufactured has the desired size and shape. The size of the semiconductor chip is typically around 0.5mm × 0.5mm to 1.0mm × 1.0mm, but is not limited to this size.

[0174] The width of the groove 23 is preferably 10 μm to 2,000 μm, more preferably 30 μm to 1,000 μm, even more preferably 40 μm to 500 μm, and even more preferably 50 μm to 300 μm, from the viewpoint of improving the embedding ability of the curable resin film (x).

[0175] The depth of the groove 23 is adjusted according to the thickness of the wafer used and the required chip thickness, preferably 30 μm to 700 μm, more preferably 60 μm to 600 μm, and even more preferably 100 μm to 500 μm.

[0176] The semiconductor chip wafer 70 prepared in process (S1) is used in process (S2).

[0177] <Process (S2)> A schematic of process (S2) is shown in Figure 8. In step (S2), the protective film-forming film 13 of the protective film-forming composite sheet 1 is pressed and attached to the bump-forming surface 21a of the semiconductor chip manufacturing wafer 30, using the protective film-forming film as the attachment surface.

[0178] In step (S2), as shown in Figure 8, the bump-forming surface 20a of the semiconductor chip manufacturing wafer 70 is covered with a protective film-forming film 13, and the protective film-forming film 13 is embedded in the grooves 23 formed in the semiconductor chip manufacturing wafer 70.

[0179] The pressing force applied when attaching the protective film-forming film 13 to the semiconductor chip manufacturing wafer 70 is preferably 1 kPa to 200 kPa, more preferably 5 kPa to 150 kPa, and even more preferably 10 kPa to 100 kPa, from the viewpoint of ensuring good embedding of the protective film-forming film 13 into the grooves 23. Furthermore, the pressing force applied when attaching the protective film-forming film 13 to the semiconductor chip manufacturing wafer 70 may be appropriately varied from the initial stage to the final stage of attachment. For example, from the viewpoint of improving the embedding of the protective film-forming film 13 into the grooves 23, it is preferable to lower the pressing force at the initial stage of attachment and gradually increase it.

[0180] Furthermore, when attaching the protective film-forming film 13 to the semiconductor chip manufacturing wafer 70, if the protective film-forming film 13 is a thermosetting resin film (x1), it is preferable to heat it in order to improve the embedding properties of the thermosetting resin film (x1) into the grooves 23. The specific heating temperature (application temperature) is preferably 50°C to 120°C, more preferably 60°C to 110°C, and even more preferably 70°C to 100°C. The heat treatment performed on the protective film 13 is not included in the curing treatment of the curable resin film (x).

[0181] Furthermore, when attaching the protective film 13 to the semiconductor chip wafer 70, it is preferable to do so under reduced pressure. This creates negative pressure in the grooves 23, making it easier for the protective film 13 to spread throughout the grooves 23. As a result, the embedding of the protective film 13 into the grooves 23 becomes better. The specific pressure of the reduced pressure environment is preferably 0.001kPa to 50kPa, more preferably 0.01kPa to 5kPa, and even more preferably 0.05kPa to 1kPa.

[0182] After the bonding process, the protective film-forming composite sheet 1 is cut along the shape of the semiconductor wafer 20. The protective film-forming composite sheet 1 of this embodiment has excellent cutability, so it can be cut well along the shape of the semiconductor wafer 20 without wrinkles or folds occurring during cutting, and without deformation of the edges after cutting. Then, the base material 10 is removed from the protective film-forming composite sheet 1. The base material 10 can be removed by known methods. Furthermore, the protective film-forming composite sheet 1 of this embodiment has excellent peelability when peeling the base material 10 from the protective film-forming composite sheet 1, so the base material 10 can be easily removed.

[0183] <Process (S3)> A schematic of process (S3) is shown in Figure 9. In step (S3), the protective film-forming film 13 is cured to obtain the wafer 70 for manufacturing semiconductor chips with the protective film 13'. The protective film 13' formed by curing the protective film-forming film 13 is stronger than the protective film-forming film 13 at normal temperature. Therefore, the bump neck can be favorably protected by forming the protective film 13'.

[0184] Curing of the protective film-forming film 13 can be performed by either thermal curing or curing by energy ray irradiation, depending on the type of curable component contained in the protective film-forming film 13. As conditions for performing thermal curing, the curing temperature is preferably 90°C to 200°C (more preferably 110°C to 170°C, still more preferably 120°C to 140°C), and the curing time is preferably 1 hour to 5 hours. As conditions for performing curing by energy ray irradiation, the conditions are appropriately set according to the type of energy ray used. For example, when ultraviolet rays are used, the illuminance is preferably 170 mw / cm 2 ~250 mw / cm 2 , and the light quantity is preferably 300 mJ / cm 2 ~3,000 mJ / cm 2 . Here, in the process of curing the protective film-forming film 13 to form the protective film 13', from the viewpoint of removing bubbles and the like that may enter when the groove portions 23 are filled with the protective film-forming film 13 in step (S2), the protective film-forming film 13 is preferably a thermosetting resin film.

[0185] <Step (S4)> The outline of step (S4) is shown in Figure 10. In step (S4), the portion of the protective film 13' of the wafer 70 for manufacturing semiconductor chips with the protective film 13' that is formed in the groove portions 23 is cut along the planned dividing lines. The cutting is performed by blade dicing. Thereby, the semiconductor chip 80 having at least the bump forming surface 20a and the side surfaces covered with the protective film 13' can be obtained. The semiconductor chip 80 has excellent strength because its bump-forming surface 20a and sides are covered with a protective film 13'. Furthermore, because the bump-forming surface 20a and sides are continuously covered with the protective film 13' without any breaks, the bonding surface (interface) between the bump-forming surface 20a and the protective film 13' is not exposed on the sides of the semiconductor chip 80. Of the bonding surface (interface) between the bump-forming surface 20a and the protective film 13', the exposed portion on the sides of the semiconductor chip 80 is prone to becoming a starting point for film peeling. In this embodiment, since such exposed portions do not exist in the semiconductor chip 80, film peeling from such exposed portions is less likely to occur during the process of cutting the semiconductor chip wafer 70 to manufacture the semiconductor chip 80, or after manufacturing. Therefore, a semiconductor chip 80 with suppressed peeling of the protective film 13' can be obtained.

[0186] Furthermore, in step (S4), when cutting the portion of the protective film 13' of the semiconductor chip manufacturing wafer 70 with the protective film 13' that is formed in the groove 23 along the planned division line, it is preferable that the protective film 13' is transparent. Because the protective film 13' is transparent, the semiconductor wafer 20 is visible through it, ensuring visibility of the planned division line. Therefore, it becomes easier to cut along the planned division line.

[0187] <Process (S-BG)> A schematic of the process (S-BG) is shown in Figure 11. In step (S-BG), as shown in (1-a) of Figure 11, first, the back surface 20b of the semiconductor chip manufacturing wafer 70 is ground with the protective film-forming composite sheet 1 attached. "BG" in Figure 11 stands for back grind. Next, as shown in (1-b) of Figure 11, the substrate 10 is peeled off from the protective film-forming composite sheet 1. When grinding the back surface 20b of the semiconductor chip manufacturing wafer 70, the amount of grinding should be at least enough to expose the bottom of the groove 23 of the semiconductor chip manufacturing wafer 70. However, further grinding may be performed to grind the protective film 13 or protective film 13' embedded in the groove 23 along with the semiconductor chip manufacturing wafer 70.

[0188] The above step (S-BG) may be performed after step (S2) and before step (S3), after step (S3) and before step (S4), or in step (S4). In particular, from the viewpoint of making it easier to exhibit the effects of the present invention, it is preferable to perform it after step (S3) and before step (S4), or in step (S4).

[0189] <Process (T)> In the semiconductor chip manufacturing method of the second embodiment of this model, it is preferable to further include the following step (T). Step (T): A step of forming a back surface protective film (rb) on the back surface of the semiconductor chip manufacturing wafer described above.

[0190] According to the manufacturing method of the above embodiment, a semiconductor chip 80 can be obtained in which at least the bump-forming surface 20a and the side surface are covered with a cured resin film (r). However, the back surface of the semiconductor chip 80 is exposed. Therefore, from the viewpoint of protecting the back surface of the semiconductor chip 80 and further improving the strength of the semiconductor chip 80, it is preferable to carry out the above step (T).

[0191] More specifically, the above process (T) preferably includes the following process (T1) and process (T2) in this order. • Process (T1): A process of attaching a protective film (xb) for the back surface to the back surface of a wafer for semiconductor chip fabrication. • Process (T2): A process to cure the back-side curable resin film (xb) to form a back-side protective film (rb).

[0192] In step (T1), a composite sheet for the back surface (α2) may be used, which is formed by laminating a support sheet (y2) and a protective film-forming film for the back surface (xb). In this case, it is preferable that the support sheet (y2) of the composite sheet for the back surface (α2) supports the curable resin film for the back surface (xb) and also functions as a dicing sheet. Furthermore, in process (S4), the composite sheet for the back surface (α2) is attached to the back surface 20b of the semiconductor wafer 70 with the protective film 13', so that when dicing is performed to separate the wafer into individual pieces, the support sheet (y2) functions as a dicing sheet, making it easier to perform dicing.

[0193] Here, if process (S3) is performed after process (S-BG), process (T1) may be performed before process (S3), and then process (S3) and process (T2) may be performed simultaneously. In other words, the protective film forming film 13 and the protective film forming film for the back surface (xb) may be cured together at the same time. This reduces the number of curing processes.

[0194] <Process (U)> The semiconductor chip manufacturing method according to the second aspect of this embodiment may further include the following step (U). Step (U): A step of removing the protective film 13' covering the top of the bump, or the protective film 13' adhering to a part of the top of the bump, to expose the top of the bump. Exposure treatments to expose the top of the bump include etching treatments such as wet etching and dry etching. Examples of dry etching processes include plasma etching. Furthermore, exposure processing may be performed to retract the protective film until the tops of the bumps are exposed, if the tops of the bumps are not exposed on the surface of the protective film.

[0195] The timing of performing step (U) is not particularly limited as long as the protective film 13' is exposed. In addition, step (U) may be performed after step 3 in the semiconductor chip manufacturing method of the first embodiment of this model. [Examples]

[0196] The present invention will be specifically described by the following examples, but the present invention is not limited to the following examples.

[0197] [Method for measuring weight average molecular weight (Mw)] The method for measuring the weight average molecular weight (Mw) in the present examples is as described below. Measurement was performed under the following conditions using a gel permeation chromatograph apparatus (manufactured by Tosoh Corporation, product name "HLC-8320GPC"), and a value converted in terms of standard polystyrene was used. (Measurement conditions) ·Column: A series of sequentially connected "TSKgel guardcolumn SuperHzH", "TSKgel SuperHZM-M", "TSKgel SuperHZM-M", and "TSKgel SuperHZ2000" (all manufactured by Tosoh Corporation) ·Column temperature: 40°C ·Developing solvent: Tetrahydrofuran ·Standard substance: Polystyrene · Injection volume: 20 μL ·Flow rate: 0.35 mL / min · Detector: Differential refractometer

[0198] [Measurement of deflection temperature under load] The deflection temperature under load was measured in accordance with Method B (measurement at a load of 0.45 MPa) of the ISO 75 (JIS K7191) standard.

[0199] [Production of thermosetting resin film] A thermosetting resin film was produced by the method shown below.

[0200] <Raw materials for thermosetting resin film> The raw materials used for producing the thermosetting resin film are shown below.

[0201] "Polymer component (A)" ·(A)-1: Polyvinyl butyral having structural units represented by the following formulas (i)-1, (i)-2 and (i)-3 (manufactured by Sekisui Chemical Co., Ltd., "S-LEC BL-10", weight average molecular weight 25,000, glass transition temperature 59°C). [Chemical Formula] (In the formula, l is approximately 28, m is between 1 and 3, and n is an integer between 68 and 74.)

[0202] "Epoxy resin (B1)" • (B1)-1: Liquid modified bisphenol A type epoxy resin (DIC Corporation's "Epiclon EXA-4850-150", number average molecular weight 900, epoxy equivalent 450 g / eq, liquid epoxy resin) • (B1)-2: Liquid special epoxy resin (ADEKA Corporation's "ADEKA Resin EP-4005", epoxy equivalent 510g / eq, flexible epoxy resin) • (B1)-3: Dicyclopentadiene type epoxy resin (DIC Corporation's "Epiclon HP-7200HH", epoxy equivalent 254-264 g / eq, solid epoxy resin) (B1)-2 is a flexible epoxy resin, and in the above general formula (2), B is a divalent group obtained by removing a hydrogen atom from the hydroxyl group of bisphenol A, and L 1 and L 2 Each of these is a flexible epoxy resin in which polyoxypropylene groups are independently present.

[0203] "Thermosetting agent (B2)" (B2)-1: o-cresol type novolac resin (DIC Corporation's "Phenolite KA-1160")

[0204] "Curing accelerator (C)" (C)-1:2-phenyl-4,5-dihydroxymethylimidazole (Shikoku Chemicals Co., Ltd. "Curesol 2PHZ-PW")

[0205] "Filling material (D)" (D)-1: Spherical silica modified with epoxy groups (Admanano YA050C-MKK, manufactured by Admatex, with an average particle size of 50 nm)

[0206] "Additives (G)" • (G)-1: Surfactant (acrylic polymer, manufactured by BYK, product name "BYK-361N") • (G)-2: Silicone oil (aralkyl-modified silicone oil, manufactured by Momentive Performance Materials Japan, product name "XF42-334")

[0207] [Base material] The following four types of substrates were prepared. In this embodiment, since the application temperature of the protective film-forming composite sheet is 80°C, whether each layer of the substrate is a core material layer or a flexible material layer was determined based on the application temperature of 80°C. • "PO / PET / PO": "Blue Olefin Double-Sided Noodles" manufactured by Ajia Aluminum Co., Ltd. This substrate consists of a polyethylene terephthalate film with polyolefin resin layers on both sides. The thickness of each layer is 25 μm for PO, 50 μm for PET, and 25 μm for PO. The load deflection temperature of PO is 50°C, which corresponds to a soft material layer. The temperature at which PET deflects under load is 100°C, which corresponds to the core material layer. • "PET": Toyobo Co., Ltd.'s "Cosmoshine A4300", thickness 75 μm This is a polyethylene terephthalate film (75 μm thick). The temperature at which PET deflects under load is 100°C, which corresponds to the core material layer. • "PE": Gunze Corporation's "Funclear LLB Type #110" It is a polyethylene film (110 μm thick). The temperature at which PE deflects under load is 40°C, which corresponds to a soft material layer.

[0208] [Example 1] (1) Preparation of thermosetting resin composition (x1-1)-1 Polymer component (A)-1 (100 parts by mass), epoxy resin (B1)-1 (150 parts by mass), epoxy resin (B1)-2 (250 parts by mass), epoxy resin (B1)-3 (200 parts by mass), thermosetting agent (B2)-1 (150 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (200 parts by mass), additive (G)-1 (2 parts by mass), and additive (G)-2 (20 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain thermosetting resin composition (x1-1)-1 in which the total concentration of all components other than the solvent was 60% by mass. Note that all amounts of components other than the solvent shown herein are the amounts of the target product without the solvent.

[0209] (2) Preparation of composite sheets for protective film formation A thermosetting resin composition (x1-1)-1 obtained above was applied to the release surface of a double-release film (Lintec Corporation's "SP-PET502150"), which is a polyethylene terephthalate film in which one side has been released by silicone treatment. The film was dried at 100°C for 2 minutes to produce a thermosetting resin film (x1)-1 with a thickness of 30 μm on the double-release film. Next, a composite sheet 1 for forming a protective film was prepared by laminating a substrate (PO / PET / PO) to the exposed surface of a thermosetting resin film (x1)-1, thereby creating a laminated structure of a substrate (PO / PET / PO), a thermosetting resin film (x1)-1 (30 μm), and a release film.

[0210] [Comparative Example 1] (1) Preparation of thermosetting resin film A thermosetting resin composition (x1-1)-1 prepared in (1) of Example 1 was applied to the release surface of a double-release film (Lintec Corporation's "SP-PET502150"), which is a polyethylene terephthalate film in which one side has been released by silicone treatment. The film was dried at 100°C for 2 minutes to produce a thermosetting resin film (x1)-1 with a thickness of 30 μm on the double-release film. Next, a lightly release film (Lintec Corporation, product name "SP-PET381130*"), in which one side of a polyethylene terephthalate film was peeled off by silicone treatment, was laminated to the exposed surface of the thermosetting resin film (x1)-1 to obtain a thermosetting resin film (x1)-1 with release films on both sides.

[0211] (2) Preparation of buffer layer A buffer layer-forming composition was prepared by blending monofunctional urethane acrylate (40 parts by mass), isobornyl acrylate (45 parts by mass), 2-hydroxypropyl acrylate (15 parts by mass), pentaerythritol tetrakis (3-mercaptobutyrate) (Resonac's "Karenz MT® PE1", a secondary tetrafunctional thiol group-containing compound, solid content concentration 100% by mass) (3.5 parts by mass), a crosslinking agent (1.8 parts by mass), and a photopolymerization initiator (2-hydroxy-2-methyl-1-phenyl-propan-1-one, BASF's "Darocure 1173", solid content concentration 100% by mass) (1.0 part by mass). Next, the buffer layer-forming composition obtained above was applied to one surface of the substrate (PET) to form a coating film. The coating film was then irradiated with ultraviolet light from the exposed side (opposite the substrate) to form a semi-cured coating film. At this time, a belt conveyor type ultraviolet irradiation device (ECS-401GGX, manufactured by iGraphix Co., Ltd.) was used as the ultraviolet irradiation device, and a high-pressure mercury lamp (H04-L41, manufactured by iGraphix Co., Ltd.) was used as the ultraviolet light source, emitting ultraviolet light with a wavelength of 365 nm at an irradiance of 120 mW / cm². 2 , light intensity 200mJ / cm 2 The irradiation was carried out under the following conditions. These irradiation conditions were determined using an ultraviolet integrated illuminance meter (UVPF-A1, manufactured by iGraphix). Next, a laminate was created by bonding the release-treated surface of a PET-based release film (Lintec Corporation's "SP-PET381031", 38 μm thick) to the exposed surface of the obtained semi-cured material. This laminate was then irradiated with ultraviolet light from outside the release film side to completely cure the semi-cured material, forming a buffer layer with a thickness of 400 μm. At this time, the same ultraviolet irradiation device and ultraviolet source as described above were used to emit ultraviolet light with a wavelength of 365 nm and an irradiance of 330 mW / cm². 2 , light intensity 1200mJ / cm 2 The irradiation was carried out under the following conditions. These irradiation conditions were determined using the same ultraviolet integrated illuminance meter as described above. As a result, a laminated sheet was obtained in which a base material (PET), a buffer layer (UA), and a release film were laminated in this order in the thickness direction.

[0212] (3) Preparation of the intermediate delamination layer At room temperature, an ethylene-vinyl acetate copolymer (weight-average molecular weight (Mw) 55,000, VA content 20% by mass) was dissolved in toluene to prepare a toluene solution with a solid content concentration of 12% by mass, thereby obtaining a composition for forming an intermediate peel layer. Next, the intermediate release layer-forming composition obtained above was applied to the release surface of a PET-based release film (Lintec Corporation's "SP-PET381031", 38 μm thick), and an intermediate release layer with a thickness of 10 μm was prepared by heating and drying at 100°C for 2 minutes.

[0213] (4) Fabrication of composite sheets for protective film formation The release film of the laminated sheet obtained above was removed, and the exposed surface of the intermediate release layer obtained above was bonded to the exposed surface of the buffer layer resulting from this, thereby obtaining a laminated sheet with an additional intermediate release layer (layer structure: base material (PET) / buffer layer / intermediate release layer / release film). Next, the release film was removed from the intermediate release layer of this laminated sheet, and the exposed surface obtained by removing the light release film from the thermosetting resin film (x1)-1 with release films on both sides was laminated to the exposed surface of the intermediate release layer resulting from this. As a result, a composite sheet 1' for forming a protective film was obtained, which was constructed by laminating a base material (PET, 75 μm thick), a buffer layer (UA, 400 μm thick), an intermediate release layer (EVA, 10 μm thick), a thermosetting resin film (x1)-1 (30 μm thick), and a double release film in this order in the thickness direction.

[0214] [Comparative Example 2] (1) Preparation of the adhesive layer An acrylic copolymer (weight-average molecular weight 800,000) was obtained by copolymerizing 2-ethylhexyl acrylate (80 parts by mass) and 2-hydroxyethyl acrylate (20 parts by mass), and adding 2-isocyanate ethyl methacrylate ("Kalenz MOI®" manufactured by Resonaq) to the acrylic copolymer such that the addition ratio to the hydroxyl groups (100 equivalents) of the constituent units derived from 2-hydroxyethyl acrylate in the acrylic copolymer was 80 equivalents. To this acrylic polymer (100 parts by mass), 1-hydroxycyclohexyl phenyl ketone (photopolymerization initiator, "Irgacure® 184" manufactured by BASF) (3 parts by mass) and trimethylolpropane adduct tolylene diisocyanate (crosslinking agent, "Coronate® L" manufactured by Tosoh Corporation) (1.1 parts by mass) were added, and a liquid solution with a concentration of 20% by mass of the acrylic polymer was prepared using methyl ethyl ketone. This liquid solution was then stirred for 30 minutes to prepare a solution-type adhesive composition. Next, the adhesive composition obtained above was applied to the release surface of a PET-based release film (Lintec Corporation's "SP-PET381031", 38 μm thick), and heated and dried at 120°C for 2 minutes to form an adhesive layer with a thickness of 10 μm.

[0215] (2) Preparation of composite sheets for protective film formation The exposed surface of the adhesive layer obtained above was bonded to the substrate (PET). Next, the release film was removed from the adhesive layer, and the exposed surface of the thermosetting resin film (x1)-1 with double-sided release films, obtained by removing the light release film, was bonded to the exposed surface of the adhesive layer. As a result, a composite sheet 2' for forming a protective film was obtained, which was constructed by laminating a base material (PET, 75 μm thick), an adhesive layer (PSA, 10 μm thick), a thermosetting resin film (x1)-1 (30 μm thick), and a release film in this order in the thickness direction.

[0216] [Comparative Example 3] The exposed surface of the intermediate release layer obtained in Comparative Example 1 was bonded to the substrate (PET) to obtain a laminated sheet (layer structure: substrate (PET) / intermediate release layer / release film). Next, the release film was removed from the intermediate release layer of this laminated sheet, and the exposed surface obtained by removing the light release film from the thermosetting resin film (x1)-1 with release films on both sides was laminated to the exposed surface of the intermediate release layer resulting from this. As a result, a composite sheet 3' for forming a protective film was obtained, which was constructed by laminating a base material (PET, 75 μm thick), an intermediate release layer (EVA, 10 μm thick), a thermosetting resin film (x1)-1 (30 μm thick), and a release film in this order in the thickness direction.

[0217] [Comparative Example 4] In Example 1, the substrate was changed to "PE," and a composite sheet 4' for forming a protective film was obtained, which was constructed by laminating a substrate (PE, 110 μm thick), a thermosetting resin film (x1)-1 (30 μm thick), and a release film in this order in the thickness direction.

[0218] [evaluation] In this embodiment, the following evaluations 1 to 4 were performed.

[0219] <Evaluation 1: Evaluation of cutting ability> (1) Preparation of half-cut wafers A silicon wafer (780 μm thick, 8 inches) was half-cut with a kerf width of 20 μm, a dicing depth of 40 μm, and a chip size of 40 μm x 40 μm to create a textured wafer with a height of 40 μm, a shape of 40 μm square, and a distance of 20 μm between adjacent bumps. The 40 μm square bumps on this wafer were treated as bumps and evaluated as described below. In the following explanation, this wafer will also be referred to as a "pseudo-wafer." The dicing conditions are as follows: (Dicing conditions) • Dicing machine: Disco DFD6363 • Blade: SD4000-HEAA-N1-90 • Rotation speed: 35krpm ·Speed; 20mm / s

[0220] (2) Application of a composite sheet for forming a protective film After removing the release film protecting the thermosetting resin film (x1)-1 from the protective film-forming composite sheet of Example 1 and Comparative Examples 1-4, the protective film-forming composite sheet was attached to the uneven surface of the simulated wafer using an attachment device. The side of the protective film-forming composite sheet attached to the simulated wafer was the side facing the thermosetting resin film (x1)-1. The lamination was performed using a roller-type laminator (Lintec Corporation, RAD-3520 F / 12) under the following lamination conditions. (Attachment conditions) • Table temperature: 80℃ ·Application speed: 3mm / s • Application pressure: 0.3 MPa • Roller application height: 0 μm After the application was complete, the composite sheet for forming the protective film was cut along the shape of the bumped pseudo-wafer.

[0221] (3) Evaluation of cutting ability After attaching the protective film-forming composite sheet to the simulated wafer under the evaluation conditions 1(2) described above, the protective film-forming composite sheet was cut along the shape of the simulated wafer. The appearance of the protective film-forming composite sheet was then visually evaluated, and those receiving an A rating were deemed acceptable. A: No deformation is observed at the ends after cutting. B: The edges after cutting are deformed and shrink, failing to maintain a flat surface. The conditions for cutting the composite sheet for protective film formation along the shape of a simulated wafer are shown below. (Conditions for cutting) • Cutting mechanism inside the adhesive application device (Lintec Corporation, RAD-3520) • Blade: Art knife (OLFA, model number "XB10") • Insert the blade along the outer edge of the simulated wafer from the support sheet side. • Art knife angle: A-axis, B-axis, and C-axis are all 0° • Cutting speed: 80mm / s

[0222] <Evaluation 2: Evaluation of peelability> After removing the release film protecting the thermosetting resin film (x1)-1 from the protective film-forming composite sheet of Example 1 and Comparative Examples 1-4, the protective film-forming composite sheet was attached to the mirror surface of an 8-inch silicon wafer using an attachment device. The side of the protective film-forming composite sheet attached to the silicon wafer was the side facing the thermosetting resin film (x1)-1. The laminating device used was a roller-type laminator (Lintec Corporation, RAD-3520 F / 12), and lamination was performed under the following conditions. (Attachment conditions) • Table temperature: 80℃ ·Application speed: 3mm / s • Application pressure: 0.3 MPa • Roller application height: 0 μm Subsequently, after cutting the attached protective film-forming composite sheet to the size of the silicon wafer, the layers other than the thermosetting resin film (x1)-1 of the protective film-forming composite sheet attached to the mirror surface of the silicon wafer were pulled at various tensile speeds in a 180° direction under conditions of a table temperature of 30°C to 60°C. It was confirmed whether the layers other than the thermosetting resin film (x1)-1 could be peeled off from the protective film-forming composite sheet attached to the mirror surface of the silicon wafer, leaving only the thermosetting resin film (x1)-1. In this example, the samples were evaluated under the following six conditions, and those that could be peeled off under any one of the conditions were deemed acceptable. 30℃ × 2mm / s 30℃ × 50 mm / s 30℃ × 100 mm / s 60℃ × 2 mm / s 60℃ × 50 mm / s 60℃ × 100 mm / s

[0223] <Evaluation 3: Evaluation of peeling force> After removing the release film protecting the thermosetting resin film (x1)-1 from the protective film-forming composite sheet of Example 1 and Comparative Examples 1-4, the protective film-forming composite sheet was attached to the mirror surface of an 8-inch silicon wafer using an attachment device. The side of the protective film-forming composite sheet attached to the silicon wafer was the side facing the thermosetting resin film (x1)-1. The laminating device used was a roller-type laminator (Lintec Corporation, RAD-3520 F / 12), and lamination was performed under the following conditions. (Attachment conditions) • Table temperature: 80℃ ·Application speed: 3mm / s • Application pressure: 0.3 MPa • Roller application height: 0 μm Subsequently, the attached protective film-forming composite sheet was cut to the size of the silicon wafer, then cut into 100 mm widths, and the samples were fixed to a universal tensile testing machine (Orientec Co., Ltd., product name "Tensilon UTM-4-100"). Next, the 100 mm width portion of the protective film-forming composite sheet attached to the mirror surface of the silicon wafer was pulled at a tensile speed of 1000 mm / min in the 180° direction under conditions of 23°C and 50% RH, in accordance with JIS Z0237:2009, and the layers other than the thermosetting resin film (x1)-1 were peeled off the protective film-forming composite sheet attached to the mirror surface of the silicon wafer, leaving only the thermosetting resin film (x1)-1 (i.e., the substrate). The force at which the layers other than the thermosetting resin film (x1)-1 (i.e., the substrate) were peeled off was measured and defined as the peel force (unit: mN / 100 mm). In this example, samples with a peeling force exceeding 40 mN / 100 mm and less than 3,000 mN / 100 mm were deemed acceptable.

[0224] <Evaluation 4: Self-adhesion (peeling strength) evaluation> Each substrate was cut to a width of 100 mm x 25 cm, and the surfaces that would come into contact with the protective film (the soft material layers) were overlapped as shown in Figure 12 and bonded together by heat lamination. Then, under conditions of 23°C and 50% RH, one substrate was peeled from the other at a peeling angle of 90° and a peeling speed of 300 mm / min, and the peeling force between the surfaces of the substrates that came into contact with the protective film (for example, the peeling force at the PO interface in Example 1) was measured. A peeling force of 3,000 mN / 25 mm or less was considered acceptable. Note that while Figure 12 illustrates the case where the substrate is PO / PET / PO, the same principle applies when stacking other substrates. Thermal lamination was performed under the following conditions. Condition: Device name (RAD-3520F / 12) Application temperature: 80℃ Pasting speed: 3mm / s Application pressure: 0.3 MPa

[0225] <Evaluation 5: Evaluation of the loss tangent tanδ of the thermosetting resin film before curing> Twenty-two sheets of thermosetting resin film (x1)-1 were prepared. Next, 22 thermosetting resin films were laminated and then cut into a 25 mm diameter disc to produce a test specimen of a protective film with a thickness of 990 μm. The lamination conditions for stacking 22 thermosetting resin films are shown below. (Lamination conditions) • Equipment: Desktop laminator (Product name: "LPD3212", manufactured by Fujipla Co., Ltd.) • Application pressure: 0.3 MPa • Application temperature: 60℃ • Application speed: 1 mm / second

[0226] Then, for the uncured specimens, the loss tangent tanδ was determined from the storage modulus and loss modulus obtained using a viscoelasticity measuring device. The measurement conditions are shown below. (Measurement conditions) • Viscoelasticity measuring device: Anton Paar MCR301 ·Measurement frequency: 1Hz ·Temperature: 80℃

[0227] The evaluation results are shown in Table 1. In Table 1, a rating of A indicates a pass, and a rating of B indicates a fail.

[0228] [Table 1]

[0229] From Table 1, the following can be seen. When using the protective film-forming composite sheet 1 of Example 1, it is found that all aspects, including cutability, peelability, and peeling force, are excellent, ensuring good coverage of the protruding electrode formation surface, including the base portion of the protruding electrode, and also exhibiting excellent handling properties. In contrast, when using the composite sheets 1' to 4' for protective film formation in Comparative Examples 1 to 4, it can be seen that at least one of the following items—cuttability, peelability, or peeling strength—is inferior. [Explanation of Symbols]

[0230] 1, 1a Composite sheet 10 Base material 11 Core material layer 12 Soft material layer 13. Film for forming protective film 13'protective membrane 20 Semiconductor wafers 21. Protruding electrodes (bumps) 23 Groove 60 Semiconductor chips with 13' protective film 70 Wafers for semiconductor chip fabrication 80 Semiconductor chips with 13' protective film

Claims

1. A composite sheet for forming a protective film is used to form a protective film on the surface of a protruding electrode of a member with a protruding electrode, and has a laminated structure in which a protective film-forming film and a substrate are laminated together, The substrate includes a core material layer and a soft material layer. The soft material layer is provided on at least one surface of the core material layer, The soft material layer provided on at least one side of the core material layer is in direct contact with the protective film forming film, Two of the above-mentioned substrates are prepared, and the two substrates are stacked so that the soft material layers are in contact with each other, and then heat-laminated at 80°C and 0.3 MPa. The peeling force between the soft material layers when peeling one substrate from the other is 3,000 mN / 25 mm or less. The load deflection temperature (T1) of the core material layer is higher than the temperature at which the protective film-forming composite sheet is attached to the protruding electrode forming surface of the member with the protruding electrode. The load deflection temperature (T2) of the soft material layer is lower than the application temperature when the protective film-forming composite sheet is applied to the protruding electrode forming surface of the member with the protruding electrode. A composite sheet for forming a protective film, wherein the peeling force when peeling the substrate from the protective film is greater than 40 mN / 100 mm and less than 3,000 mN / 100 mm.

2. A composite sheet for forming a protective film is used to form a protective film on the surface of a protruding electrode of a member with a protruding electrode, and has a laminated structure in which a protective film-forming film and a substrate are laminated together, The substrate includes a core material layer and a soft material layer. The soft material layer is provided on at least one surface of the core material layer, The soft material layer provided on at least one side of the core material layer is in direct contact with the protective film forming film, Two of the above-mentioned substrates are prepared, and the two substrates are stacked so that the soft material layers are in contact with each other, and then heat-laminated at 80°C and 0.3 MPa. The peeling force between the soft material layers when peeling one substrate from the other is 3,000 mN / 25 mm or less. The load deflection temperature (T1) of the core material layer is 50°C or higher. The load deflection temperature (T2) of the aforementioned soft material layer is 90°C or less. The load deflection temperature (T1) of the core material layer is greater than the load deflection temperature (T2) of the soft material layer. A composite sheet for forming a protective film, wherein the peeling force when peeling the substrate from the protective film is greater than 40 mN / 100 mm and less than 3,000 mN / 100 mm.

3. A composite sheet for forming a protective film is used to form a protective film on the surface of a protruding electrode of a member with a protruding electrode, and has a laminated structure in which a protective film-forming film and a substrate are laminated together, The substrate includes a core material layer and a soft material layer. The soft material layer is provided on at least one surface of the core material layer, The soft material layer provided on at least one side of the core material layer is in direct contact with the protective film forming film, Two of the above-mentioned substrates are prepared, and the two substrates are stacked so that the soft material layers are in contact with each other, and then heat-laminated at 80°C and 0.3 MPa. The peeling force between the soft material layers when peeling one substrate from the other is 3,000 mN / 25 mm or less. The load deflection temperature (T1) of the core material layer is 80°C or higher. The load deflection temperature (T2) of the aforementioned soft material layer is 80°C or less. The load deflection temperature (T1) of the core material layer is greater than the load deflection temperature (T2) of the soft material layer. A composite sheet for forming a protective film, wherein the peeling force when peeling the substrate from the protective film is greater than 40 mN / 100 mm and less than 3,000 mN / 100 mm.

4. The composite sheet for forming a protective film according to any one of claims 1 to 3, wherein the soft material layer is a polyolefin resin layer.

5. The composite sheet for forming a protective film according to any one of claims 1 to 3, wherein the core material layer is a polyethylene terephthalate resin layer.

6. A method for manufacturing a semiconductor device, comprising the step of forming a protective film on the protruding electrode forming surface of a member with protruding electrodes using a protective film forming composite sheet according to any one of claims 1 to 3.

7. The member with the protruding electrode is a semiconductor wafer having a protruding electrode forming surface equipped with a protruding electrode, and includes the following steps (S1) to (S4): Step (S1): A step to prepare a semiconductor wafer for semiconductor chip fabrication in which grooves, which are intended to be divided lines, are formed on the protruding electrode formation surface of the semiconductor wafer without reaching the back surface. Step (S2): The process of attaching the protective film-forming film of the protective film-forming composite sheet to the protruding electrode-forming surface of the semiconductor chip manufacturing wafer, covering the protruding electrode-forming surface of the semiconductor chip manufacturing wafer with the protective film-forming film, and embedding the protective film-forming film into the grooves formed in the semiconductor chip manufacturing wafer. Step (S3): A step to cure the protective film-forming film to obtain a wafer for manufacturing semiconductor chips with a protective film. Step (S4): A step to obtain a semiconductor chip in which at least the surface on which the protruding electrode is formed and the sides are covered with the protective film, by separating the wafer for fabricating the semiconductor chip with the protective film along the planned division line. Furthermore, the method for manufacturing a semiconductor device according to claim 6, comprising the following step (S-BG) after step (S2) and before step (S3), after step (S3) and before step (S4), or in step (S4). • Process (S-BG): A process for grinding the back surface of the semiconductor chip manufacturing wafer.

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