Curable resin film, composite sheet, semiconductor chip, and method of manufacturing semiconductor chip

Abstract

To provide a curable resin film that is used for forming a cured resin membrane as a protection membrane on both a bump formation surface and a lateral face of a semiconductor chip having the bump formation surface with a bump and that has an excellent processing quality after grinding and individualization; and to provide a composite sheet comprising the curable resin film, a semiconductor chip, and a method of manufacturing the semiconductor chip.SOLUTION: Provided is a curable resin film used for forming a cured resin membrane as a protection membrane on both a bump formation surface and a lateral face of a semiconductor chip having the bump formation surface with a bump. A breaking energy at 70°C of the curable resin film after curing is equal to or less than 10.0 MJ / m3.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable resin film, a composite sheet, a semiconductor chip, and a method for manufacturing the semiconductor chip. More specifically, the present invention relates to a curable resin film, a composite sheet including the curable resin film, a semiconductor chip using the curable resin film and the composite sheet, a semiconductor chip provided with a cured resin film as a protective film, and a method for manufacturing the semiconductor chip. [Background technology]

[0002] In recent years, semiconductor devices have been manufactured using a mounting method known as the face-down method, in which a semiconductor chip having bumps on its circuit surface and a substrate for mounting the semiconductor chip are stacked together so that the circuit surface of the semiconductor chip faces the substrate, thereby mounting the semiconductor chip on the substrate. The semiconductor chips are usually obtained by dividing a semiconductor wafer having bumps on its circuit surface into individual chips.

[0003] A semiconductor wafer having bumps may be provided with a protective film for the purpose of protecting the bonded portion between the bump and the semiconductor wafer (hereinafter also referred to as a "bump neck"). For example, in Patent Documents 1 and 2, a laminate in which a supporting substrate, an adhesive layer, and a thermosetting resin layer are laminated in this order is pressed and attached to the bump-forming surface of a semiconductor wafer having bumps, with the thermosetting resin layer serving as the bonding surface, and then the thermosetting resin layer is heated and cured to form a protective film. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-092594 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-169484 Summary of the Invention [Problem to be solved by the invention]

[0005] In the methods described in Patent Documents 1 and 2, a protective film is formed on a bumped wafer, and then the bumped wafer is diced together with the protective film to obtain individual semiconductor chips. When the bumped wafer is diced together with the protective film in this way, the cut surface of the protective film cut by the dicing blade has good processing quality. However, after careful consideration, the inventors have discovered a problem in that when a protective film is formed on both the bump-forming surface and the side surface of a semiconductor chip having a bump-forming surface with bumps, the processing quality of the cut surface of the protective film by the dicing blade decreases.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide a curable resin film that is used to form a cured resin film as a protective film on both the bump-forming surface and side surfaces of a semiconductor chip having a bump-forming surface with bumps, and that has excellent processing quality after grinding and singulation, a composite sheet that includes the curable resin film, a semiconductor chip, and a method for manufacturing the semiconductor chip. [Means for solving the problem]

[0007] The present inventors conducted extensive research to solve the above-mentioned problems and found that when a protective film is formed on both the bump-forming surface and the side surfaces of a semiconductor chip having a bump-forming surface with bumps, the dicing blade cuts only the protective film without cutting the wafer, resulting in a decrease in the processing quality of the cut surface of the protective film. To solve this problem, the present inventors focused on the physical properties of the curable resin film used to form the protective film and conducted further extensive research. As a result, they found that the above-mentioned problems can be solved by using a curable resin film having a breaking energy at 70°C after curing that is equal to or less than a specific value to form a protective film on a semiconductor chip, thereby completing the present invention.

[0008] That is, the present invention relates to the following: [1] A curable resin film used to form a cured resin film as a protective film on both the bump-forming surface and side surfaces of a semiconductor chip having a bump-forming surface, The breaking energy of the curable resin film at 70°C after curing is 10.0MJ / m 3 The following is a curable resin film. [2] The curable resin film according to [1] above, having a thickness of 30 μm or more. [3] A composite sheet having a laminated structure in which the curable resin film according to [1] or [2] above and a release sheet are laminated together. [4] The composite sheet according to [3] above, wherein the release sheet has a substrate and a release layer, and the release layer faces the curable resin film. [5] The composite sheet according to [4] above, further comprising an intermediate layer between the substrate and the release layer. [6] The composite sheet according to [4] or [5] above, wherein the release layer is a layer formed from a composition containing an ethylene-vinyl acetate copolymer. [7] The method includes the following steps (S1) to (S4) in this order: Step (S1): A step of preparing a semiconductor chip manufacturing wafer having a bump-forming surface with bumps, the bump-forming surface of the semiconductor wafer having grooves formed thereon as planned division lines that do not reach the rear surface. Step (S2): A step of pressing and pasting the curable resin film according to the above item [1] or [2] onto the bump-formed surface of the semiconductor chip fabrication wafer, covering the bump-formed surface of the semiconductor chip fabrication wafer with the curable resin film, and embedding the curable resin film in the grooves formed in the semiconductor chip fabrication wafer. Step (S3): A step of curing the curable resin film to obtain a wafer for producing semiconductor chips with a cured resin film. Step (S4): A step of dividing the wafer for manufacturing semiconductor chips with the cured resin film along the planned dividing lines to obtain semiconductor chips having at least the bump-forming surface and side surfaces covered with the cured resin film. The method for manufacturing a semiconductor chip further comprises 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): Step (S-BG): Grinding the back surface of the semiconductor chip fabrication wafer [8] A semiconductor chip having a bump-forming surface with bumps, the semiconductor chip having a cured resin film formed by curing the curable resin film described in [1] or [2] above on both the bump-forming surface and the side surfaces. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a curable resin film that is used to form a cured resin film as a protective film on both the bump-forming surface and side surfaces of a semiconductor chip having a bump-forming surface with bumps, and that has excellent processing quality after grinding and singulation, a composite sheet that includes the curable resin film, a semiconductor chip, and a method for manufacturing the semiconductor chip. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view showing the configuration of a composite sheet in one embodiment of the present invention. [Figure 2] FIG. 4 is a schematic cross-sectional view showing the configuration of a composite sheet according to another embodiment of the present invention. [Figure 3] 1 is a schematic cross-sectional view showing an example of a wafer for fabricating semiconductor chips prepared in step (S1). [Figure 4] FIG. 1 is a diagram showing an outline of step (S2). [Figure 5] FIG. 1 is a diagram showing an outline of step (S3). [Figure 6] FIG. 1 is a diagram showing an outline of step (S4). [Figure 7] FIG. 1 is a diagram showing an outline of step (S-BG). DETAILED DESCRIPTION OF THE INVENTION

[0011] In this specification, the term "active ingredient" refers to the components contained in the target composition excluding water and diluent solvents such as organic solvents. In addition, in this specification, "(meth)acrylic acid" refers to both "acrylic acid" and "methacrylic acid", and the same applies to other similar terms. In this specification, the weight average molecular weight and number average molecular weight are values ​​measured by gel permeation chromatography (GPC) in terms of polystyrene. Furthermore, in this specification, for preferred numerical ranges (e.g., ranges of content, etc.), the lower and upper limits described in stages can be independently combined. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60."

[0012] [Curing resin film] The curable resin film of the present invention is a curable resin film used to form a cured resin film as a protective film on both the bump-forming surface and the side surface of a semiconductor chip having a bump-forming surface, and the breaking energy of the curable resin film at 70°C after curing is 10.0 MJ / m 3 The following is the result. The breaking energy of the curable resin film at 70°C after curing is 10.0MJ / m 3 If the breaking energy exceeds 9.0 MJ / m, the cutting debris generated when the curable resin film is embedded in grooves formed in a semiconductor chip fabrication wafer and the curable resin film is cured to form a cured resin film and then cut along the planned division lines during the semiconductor chip fabrication process will become large, and the cutting debris will be more likely to remain as residue in the grooves. Therefore, if the residue adheres to the cut surface of the semiconductor chip fabrication wafer, the processing quality of the resulting semiconductor chips may be reduced. From this perspective, the breaking energy is preferably 9.0 MJ / m 3 or less, more preferably 7.0 MJ / m 3 or less, and more preferably 5.5 MJ / m3 and even more preferably 3.0 MJ / m or less. 3 The lower limit of the breaking energy is not particularly limited, but is preferably 0.1 MJ / m 3 That's all. The breaking energy can be adjusted by adjusting either or both of the type and amount of components contained in the curable resin that forms the curable resin film. The breaking energy can be measured by the method described in the examples.

[0013] The curable resin film of the present invention preferably has a breaking elongation at 70°C after curing of 85% or less, more preferably 65% ​​or less, even more preferably 45% or less, even more preferably 40% or less, even more preferably 30% or less, and even more preferably 20% or less. When the breaking elongation is equal to or less than the above value, deformation due to elongation of the cured resin film caused by frictional heat and generation of cutting debris can be suppressed during the semiconductor chip manufacturing process when the curable resin film is embedded in grooves formed in a semiconductor chip manufacturing wafer and the cured resin film is cut along the planned division lines. Therefore, deformation of the cut surface of the semiconductor chip manufacturing wafer and adhesion of cutting debris to the cut surface are less likely to occur, resulting in semiconductor chips with excellent processing quality. The lower limit of the breaking elongation is not particularly limited, but it may be 1% or more, or 3% or more. The breaking elongation can be adjusted by adjusting either or both of the type and amount of components contained in the curable resin that forms the curable resin film. The breaking elongation can be measured by the method described in the examples.

[0014] The curable resin film of the present invention preferably has a product of breaking elongation (T) and breaking energy (E) at 70°C after curing of 1000 or less, more preferably 850 or less, even more preferably 650 or less, even more preferably 450 or less, even more preferably 300 or less, and even more preferably 200 or less. When the product of breaking elongation (T) and breaking energy (E) is the above value or less, cutting debris and residual material are suppressed in the semiconductor chip manufacturing process, and the processing quality of the obtained semiconductor chips can be improved. Furthermore, the lower limit of the product of breaking elongation and breaking energy is not particularly limited, but it may be 1 or more.

[0015] The curable resin film of the present invention preferably satisfies the following requirement (I) from the viewpoint of forming a protective film that has excellent coverage on both the bump-forming surface and the side surfaces of a semiconductor chip. <Requirement (I)> A strain is generated in a test piece of the curable resin film having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz, and the storage modulus of the test piece is measured. When the storage modulus of the test piece when the strain of the test piece is 1% is defined as Gc1 and the storage modulus of the test piece when the strain of the test piece is 300% is defined as Gc300, the value X calculated by the following formula (i) is 10 or more and less than 10,000. X=Gc1 / Gc300 (i)

[0016] The upper limit of the X value specified in the above requirement (I) is preferably 5,000 or less, more preferably 2,000 or less, even more preferably 1,000 or less, still more preferably 500 or less, even more preferably 300 or less, still more preferably 100 or less, and still more preferably 70 or less, from the viewpoint of forming a protective film with excellent coverage. In order to improve the embedding property into the grooves of the wafer for producing semiconductor chips, the lower limit of the X value specified in the above requirement (I) is preferably 20 or more, more preferably 30 or more.

[0017] In the curable resin film of the present invention, Gc1 is not particularly limited as long as the X value defined in the above requirement (I) is 10 or more and less than 10,000. However, from the viewpoint of making it easier to form a protective film with excellent covering properties, Gc1 is set to 1×10 2 ~1×10 6 Pa is preferred, and 2×10 3 ~7×10 5 Pa is more preferable, and 3×10 3 ~5×10 5 Pa is more preferred.

[0018] In the curable resin film of the present invention, Gc300 is not particularly limited as long as the X value is 10 or more and less than 10,000. However, from the viewpoint of improving the embeddability of the curable resin film into the bump bases and into the grooves of the semiconductor chip fabrication wafer after the bumps penetrate the curable resin film, Gc300 is preferably 10 to 15,000 Pa, more preferably 30 to 10,000 Pa, and even more preferably 60 to 5,000 Pa.

[0019] From the viewpoint of the processing quality of chips after processing and reducing retained matter, the curable resin film of the present invention preferably has a crosslink density of 0.20 to 0.70 mol / ml, more preferably 0.40 to 0.60 mol / ml, and even more preferably 0.45 to 0.49 mol / ml. The crosslink density can be calculated by the method described in the examples below.

[0020] The thickness of the curable resin film of the present invention is preferably 30 μm or more, more preferably 40 μm or more, and even more preferably 45 μm or more from the viewpoint of good filling properties into grooves, and is preferably 250 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less from the viewpoint of suppressing contamination due to seepage during application. However, the thickness can be adjusted as appropriate because the volume of the resin to be filled varies depending on the depth and width of the grooves provided in the wafer for fabricating semiconductor chips. Here, the "thickness of the curable resin film" means the thickness of the entire curable resin film, and for example, the thickness of a curable resin film consisting of multiple layers means the total thickness of all layers that make up the curable resin film.

[0021] The curable resin film of the present invention is a film used to cover the bump-forming surface of a semiconductor chip fabrication wafer and to fill grooves formed in the semiconductor chip fabrication wafer, and forms a cured resin film by curing with heat or energy ray irradiation. The curable resin film may be a thermosetting resin film that is cured by heat or an energy ray-curable resin film that is cured by energy ray irradiation, but a thermosetting resin film is preferred from the viewpoint of making it easier to exhibit the effects of the present invention. The thermosetting resin film will be described below.

[0022] (thermosetting resin film) The thermosetting resin film contains a polymer component (A) and a thermosetting component (B). The thermosetting resin film is formed, for example, from a thermosetting resin composition containing the polymer component (A) and the thermosetting component (B). The polymer component (A) is a component that can be considered to be formed by a polymerization reaction of a polymerizable compound. The thermosetting component (B) is a component that can undergo a curing (polymerization) reaction when triggered by heat. The curing (polymerization) reaction also includes a polycondensation reaction. In the following description of this specification, "the content of each component in the total amount of active ingredients of the thermosetting resin composition" is synonymous with "the content of each component of the thermosetting resin film formed from the thermosetting resin composition."

[0023] [Polymer component (A)] The thermosetting resin film and the thermosetting resin composition contain a polymer component (A). The polymer component (A) is a polymer compound that imparts film-forming properties, flexibility, etc. to the thermosetting resin film. The polymer component (A) may be used alone or in combination of two or more. When two or more polymer components (A) are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0024] Examples of the polymer component (A) include acrylic resins (resins having (meth)acryloyl groups), polyarylate resins, polyvinyl acetal, 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 polyvinyl acetals are preferred, and polyarylate resins are more preferred.

[0025] Examples of the acrylic resin include 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. When the weight-average molecular weight of the acrylic resin is equal to or greater than the lower limit, the shape stability (stability over time during storage) of the thermosetting resin film is easily improved. Furthermore, when the weight-average molecular weight of the acrylic resin is equal to or less than the upper limit, the thermosetting resin film is easily conformable to the uneven surface of the adherend, which makes it easier to suppress the occurrence of voids between the adherend and the thermosetting resin film. Therefore, the coating property of the bump-forming surface of the semiconductor wafer is improved, and the embedding property into the grooves is also easily improved.

[0026] 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 application and handling properties of the curable resin film.

[0027] 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.

[0028] Examples of the (meth)acrylic acid ester constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and (meth) (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure and has 1 to 18 carbon atoms, such as isononyl acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate); (meth)acrylic acid cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate; (Meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester; (Meth)acrylic acid cycloalkenyloxyalkyl esters such as (meth)acrylic acid dicyclopentenyloxyethyl ester; (Meth)acrylic acid imide; glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate; hydroxyl group-containing (meth)acrylic acid esters such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; Examples include substituted amino group-containing (meth)acrylic acid esters such as N-methylaminoethyl (meth)acrylate. In this specification, the term "substituted amino group" refers to a group in which one or two hydrogen atoms of an amino group have been substituted with a group other than a hydrogen atom. Among these, from the viewpoint of the film-forming properties of the curable resin film and the adhesiveness of the curable resin film to the protective film-forming surface of a semiconductor chip, it is preferable to use a copolymer of a (meth)acrylic acid alkyl ester, a glycidyl group-containing (meth)acrylic acid ester, and a hydroxyl group-containing (meth)acrylic acid ester, in which the alkyl group constituting the alkyl ester has a chain structure containing 1 to 18 carbon atoms; it is more preferable to use a copolymer of a (meth)acrylic acid alkyl ester, a glycidyl group-containing (meth)acrylic acid ester, and a hydroxyl group-containing (meth)acrylic acid ester, in which the alkyl group constituting the alkyl ester has a chain structure containing 1 to 4 carbon atoms; and it is even more preferable to use a copolymer of a combination of butyl acrylate, methyl acrylate, glycidyl acrylate, and 2-hydroxyethyl acrylate.

[0029] The acrylic resin may be, for example, a copolymer of one or more monomers selected from (meth)acrylic acid ester, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like.

[0030] The monomer constituting the acrylic resin may be one type alone or two or more types. When the acrylic resin is composed of two or more types of monomers, the combination and ratio thereof can be selected arbitrarily.

[0031] The polyarylate resin in the polymer component (A) may be any known resin, such as a resin having a basic structure obtained by polycondensation of a dihydric phenol with a dibasic acid such as phthalic acid or carboxylic acid. Among these, a polycondensate of bisphenol A with phthalic acid, poly(4,4'-isopropylidenediphenylene terephthalate / isophthalate) copolymer, or a derivative thereof is preferred.

[0032] The polyvinyl acetal in the polymer component (A) may be any known polyvinyl acetal. Of these, preferred polyvinyl acetals include, for example, polyvinyl formal and polyvinyl butyral, with polyvinyl butyral being more preferred. Examples of polyvinyl butyral include those having structural units represented by the following formulas (i)-1, (i)-2, and (i)-3.

[0033] [ka]

[0034] (In the formula, l, m, and n each independently represent an integer of 1 or more.)

[0035] The weight-average molecular weight (Mw) of the polyvinyl acetal is preferably 5,000 to 200,000, more preferably 8,000 to 100,000. When the weight-average molecular weight of the polyvinyl acetal is equal to or greater than the above-mentioned lower limit, the shape stability (stability over time during storage) of the thermosetting resin film is easily improved. Furthermore, when the weight-average molecular weight of the polyvinyl acetal is equal to or less than the above-mentioned upper limit, the thermosetting resin film is easily conformable to the uneven surface of the adherend, which makes it easier to suppress the occurrence of voids between the adherend and the thermosetting resin film, for example. Therefore, the coverage of the bump-forming surface of the semiconductor wafer is improved, and the ability to fill grooves is also easily improved.

[0036] The glass transition temperature (Tg) of the polyvinyl acetal is preferably 40 to 80°C, more preferably 50 to 70°C, from the viewpoint of film-forming properties of the curable resin film and exposing properties of the bump tops. Here, in this specification, "exposure of the bump top" refers to the ability of the bump to penetrate a thermosetting resin film for forming a protective film when the thermosetting resin film is attached to a wafer with bumps, and is also referred to as the penetration ability of the bump top.

[0037] The ratio of the three or more monomers constituting the polyvinyl acetal can be selected arbitrarily.

[0038] The content of the polymer component (A) is preferably 2 to 30 mass %, more preferably 3 to 25 mass %, and even more preferably 3 to 15 mass %, based on the total amount of active ingredients of the thermosetting resin composition.

[0039] The polymer component (A) may also correspond to the thermosetting component (B). In the present invention, when the thermosetting resin composition contains components that correspond to both the polymer component (A) and the thermosetting component (B), the thermosetting resin composition is considered to contain both the polymer component (A) and the thermosetting component (B).

[0040] [Thermosetting component (B)] The thermosetting resin film and the thermosetting resin composition contain a thermosetting component (B). The thermosetting component (B) is a component for curing the thermosetting resin film to form a hard cured resin film. The thermosetting component (B) may be used singly or in combination of two or more. When two or more thermosetting components (B) are used, the combination and ratio thereof can be selected arbitrarily.

[0041] Examples of the thermosetting component (B) include epoxy thermosetting resins, thermosetting polyimides, polyurethanes, unsaturated polyesters, and silicone resins. Among these, epoxy thermosetting resins are preferred. When the thermosetting component (B) is an epoxy thermosetting resin, the protective properties of the cured resin film and the protruding properties of the bump tops can be improved, and warping of the cured resin film can be suppressed.

[0042] The epoxy thermosetting resin is composed of an epoxy resin (B1) and a thermosetting agent (B2). The epoxy thermosetting resin may be used alone or in combination of two or more. When two or more epoxy thermosetting resins are used, the combination and ratio thereof can be selected arbitrarily.

[0043] <Epoxy resin (B1)> The epoxy resin (B1) is not particularly limited, but from the viewpoint of making it easier to exhibit the effects of the present invention, 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). In this specification, "room temperature" refers to 5 to 35°C, preferably 15 to 25°C.

[0044] The liquid epoxy resin is not particularly limited as long as it is liquid at room temperature, and examples thereof include bisphenol A type epoxy resins, bisphenol F type epoxy resins, novolac type epoxy resins, glycidyl ester type epoxy resins, biphenyl type epoxy resins, phenylene skeleton type epoxy resins, etc. Among these, bisphenol A type epoxy resins are preferred. The liquid epoxy resin may be used alone or in combination of two or more. When two or more liquid epoxy resins are used, the combination and ratio thereof can be selected arbitrarily.

[0045] 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 500 g / eq.

[0046] The solid epoxy resin is not particularly limited as long as it is solid at room temperature, and examples thereof include biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, orthocresol novolac epoxy resins, dicyclopentadiene-type epoxy resins, naphthalene-type epoxy resins, anthracene-type epoxy resins, fluorene-skeleton-type epoxy resins, etc. Among these, naphthalene-type epoxy resins and fluorene-skeleton-type epoxy resins are preferred, and fluorene-skeleton-type epoxy resins are more preferred. The solid epoxy resin may be used alone or in combination of two or more. When two or more solid epoxy resins are used, the combination and ratio thereof can be selected arbitrarily.

[0047] The epoxy equivalent of the solid epoxy resin is preferably 150 to 450 g / eq, more preferably 150 to 400 g / eq.

[0048] The ratio ((x) / (y)) of the content of the liquid epoxy resin (x) to the content of the solid epoxy resin (y) is preferably 0.2 to 10.0 by mass, more preferably 0.3 to 8.0, even more preferably 0.4 to 6.0, and still more preferably 0.5 to 5.0. When the ratio ((x) / (y)) is within the above range, the breaking energy at 70°C after curing of the curable resin film can be easily adjusted to the above-mentioned value or less.

[0049] The number average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoints of the curability of the thermosetting resin film and the strength and heat resistance of the cured 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.

[0050] <Heat curing agent (B2)> The heat curing agent (B2) functions as a curing agent for the epoxy resin (B1). The thermosetting agent (B2) may be, for example, a compound having two or more functional groups per molecule that can react with an epoxy group. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an anhydride group of an acid group. A phenolic hydroxyl group, an amino group, or an anhydride group of an acid group is preferred, and a phenolic hydroxyl group or an amino group is more preferred.

[0051] Among the heat curing agents (B2), examples of phenolic curing agents having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-based phenolic resins, and aralkyl phenolic resins. Among the heat curing agents (B2), examples of amine-based curing agents having an amino group include dicyandiamide (hereinafter sometimes abbreviated as "DICY"). Among these, from the viewpoint of making it easier to exhibit the effects of the present invention, phenolic curing agents having a phenolic hydroxyl group are preferred, and novolac-type phenolic resins are more preferred.

[0052] Of the thermosetting agents (B2), for example, the number average molecular weight of resin components such as polyfunctional phenol resins, novolac-type phenol resins, dicyclopentadiene-based phenol resins, and aralkyl phenol resins is preferably 300 to 30,000, more preferably 400 to 10,000, and even more preferably 500 to 3,000. Of the thermosetting agent (B2), the molecular weight of the non-resin component such as biphenol or dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

[0053] The heat curing agent (B2) may be used singly or in combination of two or more. When two or more types of heat curing agents (B2) are used, the combination and ratio thereof can be selected arbitrarily.

[0054] In the thermosetting resin composition, the content of the thermosetting agent (B2) is preferably 1 to 200 parts by mass, more preferably 5 to 150 parts by mass, even more preferably 10 to 100 parts by mass, and even more preferably 15 to 77 parts by mass, per 100 parts by mass of the epoxy resin (B1). When the content of the thermosetting agent (B2) is at least the above lower limit, curing of the thermosetting resin film proceeds more easily. Furthermore, when the content of the thermosetting agent (B2) is at most the above upper limit, the moisture absorption rate of the thermosetting resin film is reduced, and the reliability of the package obtained using the thermosetting resin film is further improved.

[0055] In the thermosetting resin composition, the content of the thermosetting component (B) (total content of the epoxy resin (B1) and the thermosetting agent (B2)) is preferably 200 to 3,000 parts by mass, more preferably 300 to 2,000 parts by mass, even more preferably 400 to 1,000 parts by mass, and even more preferably 500 to 800 parts by mass, relative to 100 parts by mass of the polymer component (A), from the viewpoint of enhancing the protective properties of the cured resin film.

[0056] [Curing accelerator (C)] The thermosetting resin film and the thermosetting resin composition may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing rate of the thermosetting resin composition. Preferred examples of the curing accelerator (C) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines (phosphines in which one or more hydrogen atoms are substituted with organic groups) such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate. 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.

[0057] The curing accelerator (C) may be used singly or in combination of two or more. When two or more curing accelerators (C) are used, the combination and ratio thereof can be selected arbitrarily.

[0058] When a curing accelerator (C) is used in the thermosetting resin composition, the content of the curing accelerator (C) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the thermosetting component (B). When the content of the curing accelerator (C) is equal to or greater than the above-mentioned lower limit, the effects of using the curing accelerator (C) are more pronounced. Furthermore, when the content of the curing accelerator (C) is equal to or less than the above-mentioned upper limit, for example, the effect of suppressing the highly polar curing accelerator (C) from migrating and segregating to the adhesive interface with the adherend in the thermosetting resin film under high temperature and high humidity conditions is enhanced, thereby further improving the reliability of the package obtained using the thermosetting resin film.

[0059] [Filler (D)] The thermosetting resin film and the thermosetting resin composition may contain a filler (D). The inclusion of the filler (D) makes it easier to adjust the thermal expansion coefficient of the cured resin film obtained by curing the thermosetting resin film within an appropriate range, thereby further improving the reliability of the package obtained using the thermosetting resin film. Furthermore, the inclusion of the filler (D) in the thermosetting resin film can also reduce the moisture absorption rate of the cured resin film and improve heat dissipation.

[0060] The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler. Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride, etc.; beads obtained by spheroidizing these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; glass fibers, etc. Among these, from the viewpoint of more easily achieving the effects of the present invention, the inorganic filler is preferably silica or alumina.

[0061] The filler (D) may be used alone or in combination of two or more kinds. When two or more types of filler (D) are used, the combination and ratio thereof can be selected arbitrarily.

[0062] When filler (D) is used, the content of filler (D) is preferably 5 to 50 mass%, more preferably 7 to 40 mass%, and even more preferably 10 to 30 mass%, based on the total amount of active ingredients of the thermosetting resin composition, from the viewpoint of suppressing peeling of the cured resin film from the chip due to thermal expansion and thermal contraction.

[0063] The average particle diameter of the filler (D) is preferably 5 nm to 1000 nm, more preferably 5 nm to 500 nm, and even more preferably 10 nm to 300 nm. The average particle diameter is determined by measuring the outer diameter of a single particle at several points and calculating the average value.

[0064] [Energy ray curable resin (E)] The thermosetting resin film and the thermosetting resin composition may contain an energy ray-curable resin (E). The thermosetting resin film contains the energy ray-curable resin (E), and thus the properties can be changed by irradiation with energy rays.

[0065] The energy ray curable resin (E) is obtained by polymerizing (curing) an energy ray curable compound. Examples of the energy ray curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferred.

[0066] Examples of acrylate compounds include chain acrylates such as trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Examples of the polyalkylene glycol (meth)acrylate include aliphatic skeleton-containing (meth)acrylates; alicyclic skeleton-containing (meth)acrylates such as dicyclopentanyl di(meth)acrylate; polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; oligoester (meth)acrylates; urethane (meth)acrylate oligomers; epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the above polyalkylene glycol (meth)acrylates; and itaconic acid oligomers.

[0067] The weight average molecular weight of the energy ray-curable compound is preferably from 100 to 30,000, and more preferably from 300 to 10,000.

[0068] The energy ray-curable compound used for polymerization may be used alone or in combination of two or more. When two or more energy ray-curable compounds are used for polymerization, the combination and ratio thereof can be selected arbitrarily.

[0069] When the energy ray-curable resin (E) is used, the content of the energy ray-curable resin (E) is preferably 1 to 95 mass%, more preferably 5 to 90 mass%, and even more preferably 10 to 85 mass%, based on the total amount of the active ingredients of the thermosetting resin composition.

[0070] [Photopolymerization initiator (F)] When the thermosetting resin film and the thermosetting resin composition contain an energy ray-curable resin (E), the thermosetting resin film and the thermosetting resin composition may contain a photopolymerization initiator (F) to efficiently proceed with the polymerization reaction of the energy ray-curable resin (E).

[0071] Examples of the photopolymerization initiator (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.

[0072] The photopolymerization initiator (F) may be used singly or in combination of two or more. When two or more photopolymerization initiators (F) are used, the combination and ratio thereof can be selected arbitrarily.

[0073] In the thermosetting resin composition, 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, relative to 100 parts by mass of the content of the energy ray-curable resin (E).

[0074] [Additive (G)] The thermosetting resin film and the thermosetting resin composition may contain an additive (G) within a range that does not impair the effects of the present invention. The additive (G) may be a known additive and can be selected arbitrarily depending on the purpose, and is not particularly limited. Preferred examples of the additive (G) include coupling agents, crosslinking agents, surfactants, plasticizers, antistatic agents, antioxidants, and gettering agents.

[0075] The additive (G) may be used singly or in combination of two or more. When two or more general-purpose additives (G) are used, the combination and ratio thereof can be selected arbitrarily. The content of the additive (G) is not particularly limited and may be appropriately selected depending on the purpose.

[0076] 〔solvent〕 The thermosetting resin composition preferably further contains a solvent. A thermosetting resin composition containing a solvent has good handleability. The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The solvent may be used alone or in combination of two or more. When two or more solvents are used, the combination and ratio thereof can be selected arbitrarily. The solvent is preferably methyl ethyl ketone or the like, since it allows the components contained in the thermosetting resin composition to be mixed more uniformly.

[0077] (Method for preparing thermosetting resin composition) The thermosetting resin composition is prepared by blending the components that constitute it. The order of addition of the components when blending is not particularly limited, and two or more components may be added simultaneously. When a solvent is used, the solvent may be mixed with any of the other components to pre-dilute the components, or the solvent may be mixed with any of the other components without pre-diluting them. The method for mixing the components during blending is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer or stirring blades, a method of mixing using a mixer, or a method of mixing by adding ultrasound. The temperature and time for adding and mixing each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. A temperature of 15 to 30°C is preferred.

[0078] [Composite sheet] The curable resin film of one embodiment of the present invention may be a composite sheet having a laminated structure in which the curable resin film and a release sheet are laminated together. By forming the composite sheet, the curable resin film is stably supported and protected when transporting the curable resin film as a product package or when transporting the curable resin film in a semiconductor chip manufacturing process. FIG. 1 is a schematic cross-sectional view showing the configuration of a composite sheet according to one embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view showing the configuration of a composite sheet according to another embodiment of the present invention. 1 has a release sheet 1 and a curable resin film 2 provided on the release sheet 1. The release sheet 1 has a substrate 3 and a release layer 4, and the release layer 4 is provided so as to face the curable resin film 2. 2 has a release sheet 11 and a curable resin film 12 provided on the release sheet 11. The release sheet 11 may have an intermediate layer 15 provided between the substrate 13 and the release layer 14. A laminate in which the substrate 13, the intermediate layer 15, and the release layer 14 are laminated in this order is suitable for use as a backgrind sheet. Each layer constituting the release sheet used in the composite sheet of the present invention will now be described.

[0079] (base material) The substrate is in the form of a sheet or film, and examples of the constituent materials thereof include the following various resins. Examples of resins constituting the substrate include polyethylenes such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene-based copolymers (copolymers obtained using ethylene as a monomer) such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer; and vinyl chloride-based resins (copolymers obtained using vinyl chloride as a monomer) such as polyvinyl chloride and vinyl chloride copolymer. resins obtained by the above method); polystyrene; polycycloolefin; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and wholly aromatic polyesters in which all structural units have aromatic cyclic groups; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxides; polyphenylene sulfides; polysulfones; and polyether ketones. Further, examples of the resin constituting the substrate include polymer alloys such as mixtures of the above polyesters with other resins. The polymer alloys of the above polyesters with other resins preferably contain a relatively small amount of resin other than polyester. Further, examples of the resin constituting the substrate include crosslinked resins in which one or more of the resins exemplified above are crosslinked; and modified resins such as ionomers using one or more of the resins exemplified above.

[0080] The resin constituting the substrate may be one type used alone or two or more types used in combination. When the substrate is composed of two or more types of resins, the combination and ratio thereof can be selected arbitrarily.

[0081] The substrate may be one layer (single layer) or two or more layers. When the substrate is a multilayer substrate, these layers may be the same or different from each other, and the combination of these layers is not particularly limited.

[0082] The thickness of the substrate is preferably 5 μm to 1,000 μm, more preferably 10 μm to 500 μm, even more preferably 15 μm to 300 μm, and even more preferably 20 μm to 150 μm. Here, the "thickness of the substrate" means the thickness of the entire substrate, and for example, the thickness of a substrate consisting of multiple layers means the total thickness of all layers that make up the substrate.

[0083] The substrate preferably has a high thickness accuracy, i.e., a thickness variation that is suppressed regardless of location. Among the above-mentioned constituent materials, examples of materials with a high thickness accuracy that can be used to constitute the substrate include polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, polybutylene terephthalate, and ethylene-vinyl acetate copolymer.

[0084] In addition to the main constituent materials such as the resins described above, the substrate may contain various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, and softeners (plasticizers).

[0085] The substrate may be transparent or opaque, may be colored as desired, or may have other layers vapor-deposited thereon.

[0086] The substrate can be produced by a known method. For example, a substrate containing a resin can be produced by molding a resin composition containing the resin.

[0087] (peeling layer) The release layer has a function of imparting releasability to the release sheet, and is formed, for example, from a cured product of a release layer-forming composition containing a release agent. The release agent is not particularly limited, and examples thereof include silicone resin, alkyd resin, acrylic resin, ethylene-vinyl acetate copolymer, etc. Among these, ethylene-vinyl acetate copolymer is preferred from the viewpoint of improving the protruding properties of the bump tops and from the viewpoint of peelability from the cured resin film.

[0088] The release layer may be one layer (single layer) or two or more layers. When the release layer is a multi-layer, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0089] From the viewpoint of releasability and handleability, the thickness of the release layer is preferably 3 to 50 μm, more preferably 5 to 30 μm. Here, the "thickness of the release layer" means the thickness of the entire release layer, and for example, the thickness of a release layer consisting of multiple layers means the total thickness of all layers that make up the release layer.

[0090] (middle class) The intermediate layer is in the form of a sheet or film, and its constituent material may be appropriately selected depending on the purpose and is not particularly limited. For example, when the purpose is to prevent the cured resin film from being deformed by the shape of bumps present on the semiconductor surface being reflected in the protective film covering the semiconductor surface, a preferred constituent material for the intermediate layer is urethane (meth)acrylate, etc., which has high conformability to irregularities and further improves the adhesion of the intermediate layer.

[0091] The intermediate layer may be one layer (single layer) or two or more layers. When the intermediate layer is a multi-layer structure, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0092] The thickness of the intermediate layer can be adjusted appropriately depending on the height of the bumps on the semiconductor surface to be protected, but is preferably 50 μm to 600 μm, more preferably 70 μm to 500 μm, and even more preferably 80 μm to 400 μm, so as to easily absorb the effects of relatively tall bumps. Here, the "thickness of the intermediate layer" refers to the thickness of the entire intermediate layer; for example, the thickness of an intermediate layer consisting of multiple layers refers to the total thickness of all the layers that make up the intermediate layer.

[0093] (Manufacturing method of composite sheet) The composite sheet can be produced by laminating the above-mentioned layers in order so that they are in a corresponding positional relationship. For example, when manufacturing a composite sheet, if a release layer or intermediate layer is laminated on a substrate, the release layer or intermediate layer can be laminated by applying a composition for forming a release layer or a composition for forming an intermediate layer to the substrate and drying it as necessary or irradiating it with energy rays. Examples of the coating method include spin coating, spray coating, bar coating, knife coating, roll coating, roll knife coating, blade coating, die coating, and gravure coating.

[0094] On the other hand, for example, when a curable resin film is laminated on a release layer already laminated on a substrate, it is possible to directly form the curable resin film by applying a thermosetting resin composition onto the release layer. Similarly, when a release layer is to be laminated on top of an intermediate layer already laminated on a substrate, the release layer can be formed directly by applying a composition for forming a release layer onto the intermediate layer.

[0095] Thus, when forming a continuous two-layer laminate structure using any of the compositions, it is possible to form a new layer by applying another composition on the layer formed from the composition. However, it is preferable that the layer to be laminated later is first formed on a separate release film using the composition, and the exposed surface of this formed layer opposite the side in contact with the release film is bonded to the exposed surface of the remaining layer already formed to form a continuous two-layer laminate structure. In this case, it is preferable that the composition is applied to the release-treated surface of the release film. The release film can be removed as needed after the laminate structure is formed.

[0096] [Semiconductor chip manufacturing method] The method for manufacturing semiconductor chips of the present invention roughly includes a step (S1) of preparing a wafer for semiconductor chip production, a step (S2) of applying a curable resin film, a step (S3) of curing the curable resin film, and a step (S4) of singulating, and further includes a step (S-BG) of grinding the back surface of the wafer for semiconductor chip production.

[0097] Specifically, the method for producing a semiconductor chip of the present invention includes the following steps (S1) to (S4) in this order. Step (S1): A step of preparing a semiconductor chip manufacturing wafer having a bump-forming surface with bumps, the bump-forming surface of the semiconductor wafer having grooves formed thereon as planned division lines that do not reach the rear surface. Step (S2): A step of pressing and pasting the curable resin film onto the bump-formed surface of the semiconductor chip fabrication wafer, covering the bump-formed surface of the semiconductor chip fabrication wafer with the curable resin film, and embedding the curable resin film in the grooves formed in the semiconductor chip fabrication wafer. Step (S3): A step of curing the curable resin film to obtain a wafer for producing semiconductor chips with a cured resin film. Step (S4): A step of dividing the wafer for producing semiconductor chips with the cured resin film along the planned dividing lines to obtain semiconductor chips having at least the bump-forming surface and side surfaces covered with the cured resin film. Furthermore, the method includes 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). Step (S-BG): Grinding the back surface of the semiconductor chip fabrication wafer

[0098] In the semiconductor chip manufacturing method of the present invention, the curable resin film is embedded in grooves formed in a semiconductor chip manufacturing wafer, and the curable resin film is cured to form a cured resin film, and when the cured resin film is cut along the planned division lines, the cutting debris generated is small and the cutting debris is less likely to remain as residue.As a result, the residue is less likely to adhere to the cut surface of the wafer, and semiconductor chips with excellent processing quality can be obtained. In the semiconductor chip manufacturing method of the present invention, when the curable resin film is embedded in grooves formed in a semiconductor chip fabrication wafer and the curable resin film is cured to form a cured resin film, which is then cut along the planned division lines, the dicing blade cuts only the cured resin film without cutting the semiconductor chip fabrication wafer. Therefore, unlike when the semiconductor chip fabrication wafer is cut together with the cured resin film, the effect of removing the cutting debris from the cured resin film along with the cutting debris from the semiconductor chip fabrication wafer and the effect of exposing the abrasive grains when cutting the semiconductor chip fabrication wafer with the dicing blade are not achieved, and the processing quality of the cut surface of the cured resin film by the dicing blade is likely to be reduced. However, in the present invention, the breaking energy at 70°C after curing of the curable resin film is 10.0 MJ / m 3 The following adjustments make it possible to obtain semiconductor chips with excellent processing quality without reducing the processing quality of the cut surface of the cured resin film by the dicing blade. Furthermore, by using a manufacturing method including the above steps, a semiconductor chip can be obtained in which not only the bump-forming surface but also the side surfaces are covered with a cured resin film, which has excellent strength and is less likely to peel off as a protective film. The term "covered" used here means that a cured resin film is formed along the shape of the semiconductor chip on at least the bump-forming surface and side surfaces of one semiconductor chip.

[0099] Each step of the method for manufacturing a semiconductor chip of the present invention will be described in detail below. In the following description, a "semiconductor chip" will also be referred to simply as a "chip," and a "semiconductor wafer" will also be referred to simply as a "wafer." Furthermore, a curable resin film (the curable resin film of the present invention) for forming a cured resin film as a protective film on both the bump-formed surface and the side surface of a semiconductor chip is also referred to as a "first curable resin film (X1)." The cured resin film formed by curing the "first curable resin film (X1)" is also referred to as a "first cured resin film (r1)." The curable resin film for forming a cured resin film as a protective film on the surface (rear surface) opposite to the bump-formed surface of a semiconductor chip is also referred to as a "second curable resin film (X2)." The cured resin film formed by curing the "second curable resin film (X2)" is also referred to as a "second cured resin film (r2)." Furthermore, the composite sheet for forming the first cured resin film (r1) as a protective film on both the bump-forming surface and the side surfaces of the semiconductor chip is also referred to as the "first composite sheet (α1)." The "first composite sheet (α1)" has a laminated structure in which a "first release sheet (Y1)" and a "first curable resin film (X1)" are laminated. In addition, the composite sheet for forming the second cured resin film (r2) as a protective film on the back surface of the semiconductor chip is also referred to as the "second composite sheet (α2)." The "second composite sheet (α2)" has a laminated structure in which a "second release sheet (Y2)" and a "second curable resin film (X2)" are laminated.

[0100] [Process (S1)] FIG. 3 shows a schematic cross-sectional view of an example of the semiconductor wafer prepared in step (S1). In step (S1), a semiconductor chip manufacturing wafer 30 is prepared, in which grooves 23 serving as planned division lines are formed on the bump formation surface 21a of the semiconductor wafer 21, the bump formation surface 21a having bumps 22, without reaching the back surface 21b.

[0101] The shape of the bumps 22 is not particularly limited, and may be any shape as long as it can be brought into contact with and fixed to electrodes on a chip-mounting substrate. For example, although the bumps 22 are shown as spherical in FIG. 3, the bumps 22 may also be spheroids. The spheroids may be, for example, spheroids elongated in a direction perpendicular to the bump-forming surface 21a of the wafer 21, or spheroids elongated in a direction horizontal to the bump-forming surface 21a of the wafer 21. Furthermore, the bumps 22 may also be pillar-shaped.

[0102] The height of the bumps 22 is not particularly limited and may be changed as appropriate according to design requirements. For example, it is 30 μm to 300 μm, preferably 60 μm to 250 μm, and more preferably 80 μm to 200 μm. It should be noted that "the height of the bump 22" means the height of the portion of one bump that is located at the highest position from the bump formation surface 21a.

[0103] The number of bumps 22 is not particularly limited either, and may be changed as appropriate according to design requirements.

[0104] The wafer 21 is a semiconductor wafer having circuits such as wiring, capacitors, diodes, and transistors formed on its surface. The material of the wafer is not particularly limited, and examples thereof include a silicon wafer, a silicon carbide wafer, a compound semiconductor wafer, a glass wafer, and a sapphire wafer.

[0105] The size of wafer 21 is not particularly limited, but from the viewpoint of improving batch processing efficiency, it is usually 8 inches (diameter 200 mm) or more, and preferably 12 inches (diameter 300 mm) or more. The shape of wafer 21 is not limited to a circle, and may be a polygonal shape such as a square or rectangle. In the case of a polygonal wafer, from the viewpoint of improving batch processing efficiency, it is preferable that the length of the longest side of wafer 21 is equal to or greater than the above size (diameter).

[0106] The thickness of the wafer 21 is not particularly limited, but is preferably 100 μm to 1,000 μm, more preferably 200 μm to 900 μm, and even more preferably 300 μm to 800 μm, from the viewpoint of easily suppressing warpage due to shrinkage when the curable resin film is cured and from the viewpoint of reducing the amount of grinding of the back surface 21b of the wafer 21 in a later process and thereby shortening the time required for back surface grinding.

[0107] A plurality of grooves 23 are formed in a grid pattern on the bump formation surface 21a of the semiconductor chip fabrication wafer 30 prepared in step (S1) as planned division lines when the semiconductor chip fabrication wafer 30 is singulated. The plurality of grooves 23 are cut grooves formed when applying a blade tip dicing method (dicing before grinding), and are formed to a depth shallower than the thickness of the wafer 21 so that the deepest parts of the grooves 23 do not reach the back surface 21b of the wafer 21. The plurality of grooves 23 can be formed by dicing using a conventionally known wafer dicing device equipped with a dicing blade, or the like. The grooves 23 may be formed so that the semiconductor chip to be manufactured has a desired size and shape. The size of the semiconductor chip is usually about 0.5 mm x 0.5 mm to 1.0 mm x 1.0 mm, but is not limited to this size.

[0108] From the viewpoint of improving embedding properties of the curable resin film, 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.

[0109] The depth of the groove 23 is adjusted according to the thickness of the wafer used and the required chip thickness, and is preferably 30 μm to 700 μm, more preferably 60 μm to 600 μm, and even more preferably 100 μm to 500 μm.

[0110] The semiconductor chip fabrication wafer 30 prepared in the step (S1) is subjected to the step (S2).

[0111] [Process (S2)] An outline of step (S2) is shown in FIG. In the step (S2), a first hardening resin film (X1) is pressed onto the bump formation surface 21a of the semiconductor chip fabrication wafer 30 and attached thereto. Here, from the viewpoint of ease of handling, the first curable resin film (X1) may be used as a first composite sheet (α1) having a laminated structure in which a first release sheet (Y1) and the first curable resin film (X1) are laminated. When the first composite sheet (α1) is used, the first curable resin film (X1) of the first composite sheet (α1) is pressed onto the bump formation surface 21a of the semiconductor chip fabrication wafer 30 with the first curable resin film (X1) as the attachment surface.

[0112] In step (S2), as shown in FIG. 4, the bump forming surface 21a of the semiconductor chip fabrication wafer 30 is covered with a first curable resin film (X1), and the first curable resin film (X1) is embedded in the groove portion 23 formed in the semiconductor chip fabrication wafer 30.

[0113] The pressure applied when attaching the first hardening resin film (X1) to the semiconductor chip fabrication wafer 30 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 first hardening resin film (X1) into the groove portions 23. The pressure applied when attaching the first hardening resin film (X1) to the semiconductor chip fabrication wafer 30 may be varied as appropriate from the beginning to the end of the attachment process. For example, from the viewpoint of improving the embedding properties of the first hardening resin film (X1) in the grooves 23, it is preferable to lower the pressure applied at the beginning of the attachment process and gradually increase the pressure applied.

[0114] Furthermore, when attaching the first curable resin film (X1) to the semiconductor chip manufacturing wafer 30, if the first curable resin film (X1) is a thermosetting resin film, it is preferable to heat it in order to improve the embeddability of the first curable resin film (X1) into the groove portion 23. Specifically, the heating temperature (application temperature) is preferably 50°C to 150°C, more preferably 60°C to 130°C, and even more preferably 70°C to 110°C. The heat treatment performed on the first hardenable resin film (X1) is not included in the hardening treatment of the first hardenable resin film (X1).

[0115] Furthermore, when the first curable resin film (X1) is attached to the semiconductor chip fabrication wafer 30, it is preferable to do so in a reduced pressure environment. This creates a negative pressure in the grooves 23, making it easier for the first curable resin film (X1) to spread throughout the entire grooves 23. As a result, the first curable resin film (X1) is more easily embedded in the grooves 23. The specific pressure of the reduced pressure environment is preferably 0.001 kPa to 50 kPa, more preferably 0.01 kPa to 5 kPa, and even more preferably 0.05 kPa to 1 kPa.

[0116] [Process (S3)] An outline of step (S3) is shown in FIG. In the step (S3), the first curable resin film (X1) is cured to obtain a semiconductor chip fabrication wafer 30 with a first curable resin layer (r1) thereon. The first cured resin film (r1) formed by curing the first cured resin film (X1) is stronger than the first cured resin film (X1) at room temperature, and therefore the formation of the first cured resin film (r1) provides good protection for the bump neck.

[0117] The first curable resin film (X1) can be cured by either heat curing or curing by irradiation with energy rays, depending on the type of curable component contained in the first curable resin film (X1). In this specification, the term "energy rays" refers to electromagnetic waves or charged particle beams that have an energy quantum, and examples thereof include ultraviolet rays and electron beams, with ultraviolet rays being preferred. When thermal curing is carried out, the curing temperature is preferably 90° C. to 200° C., and the curing time is preferably 1 hour to 3 hours. The conditions for curing by energy ray irradiation are appropriately set depending on the type of energy ray used. For example, when ultraviolet light is used, the illuminance is preferably 170 mW / cm 2 ~250mW / cm 2 and the light intensity is preferably 300 mJ / cm 2 ~3,000mJ / cm 2 is. Here, in the process of curing the first curable resin film (X1) to form the first cured resin film (r1), it is preferable that the first curable resin film (X1) is a thermosetting resin film, from the viewpoint of removing air bubbles and the like that may get in when filling the groove portion 23 with the first curable resin film (X1) in step (S2).

[0118] [Process (S4)] An outline of step (S4) is shown in FIG. In the step (S4), the portions of the first cured resin film (r1) of the semiconductor chip fabrication wafer 30 having the first cured resin film (r1) formed in the grooves 23 are cut along the planned dividing lines. The first cured resin film (r1) is formed by curing the curable resin film of the present invention, and therefore the breaking energy of the first cured resin film (r1) at 70°C is 10.0 MJ / m 3 The following is satisfied. Therefore, in step (S4), when the portion of the first cured resin film (r1) formed in the groove portion 23 is cut along the planned dividing line, cutting debris generated is small, and the cutting debris is less likely to remain as residue. Therefore, residue is less likely to adhere to the cut surface of the wafer, and semiconductor chips with excellent processing quality can be obtained.

[0119] The cutting is performed by blade dicing, thereby obtaining semiconductor chips 40 in which at least the bump-forming surface 21a and the side surfaces are covered with the first cured resin film (r1). The semiconductor chip 40 has excellent strength because the bump-forming surface 21a and side surfaces are coated with the first cured resin film (r1). Furthermore, because the bump-forming surface 21a and side surfaces are continuously and seamlessly coated with the first cured resin film (r1), the bonding surface (interface) between the bump-forming surface 21a and the first cured resin film (r1) is not exposed on the side surfaces of the semiconductor chip 40. The exposed portion of the bonding surface (interface) between the bump-forming surface 21a and the first cured resin film (r1) that is exposed on the side surfaces of the semiconductor chip 40 is likely to become the starting point for film peeling. Since the semiconductor chip 40 of the present invention does not have such an exposed portion, film peeling from the exposed portion is unlikely to occur during the process of cutting the semiconductor chip fabrication wafer 30 to manufacture the semiconductor chip 40 or after manufacture. Therefore, a semiconductor chip 40 can be obtained in which peeling of the first cured resin film (r1) serving as a protective film is suppressed.

[0120] In step (S4), when the portions of the first cured resin film (r1) of the semiconductor chip fabrication wafer 30 that are formed in the groove portions 23 are cut along the planned division lines, it is preferable that the first cured resin film (r1) be transparent. The transparency of the first cured resin film (r1) allows the semiconductor wafer 21 to be seen through, ensuring visibility of the planned division lines. This makes it easier to cut along the planned division lines.

[0121] [Process (S-BG)] The outline of step (S-BG) is shown in FIG. In step (S-BG), as shown in FIG. 7(1-a), first, the back surface 21b of the semiconductor chip fabrication wafer 30 is ground with the first composite sheet (α1) attached. "BG" in FIG. 7 stands for back grinding. Next, as shown in FIG. 7(1-b), the first release sheet (Y1) is peeled off from the first composite sheet (α1). The amount of grinding when grinding the back surface 21b of the semiconductor chip manufacturing wafer 30 should be an amount that exposes at least the bottom of the groove portion 23 of the semiconductor chip manufacturing wafer 30, but further grinding may be carried out so that the first curable resin film (X1) or the first curable resin film (r1) embedded in the groove portion 23 is also ground together with the semiconductor chip manufacturing wafer 30.

[0122] The step (S-BG) may be performed after the step (S2) and before the step (S3), after the step (S3) and before the step (S4), or during the step (S4). Of these, from the viewpoint of more easily achieving the effects of the present invention, it is preferable to perform the step (S-BG) after the step (S3) and before the step (S4), or during the step (S4).

[0123] [Process (T)] In one aspect of the method for producing a semiconductor chip of the present invention, it is preferable to further include the following step (T). Step (T): A step of forming a second cured resin film (r2) on the back surface of the semiconductor chip fabrication wafer.

[0124] According to the manufacturing method of the above embodiment, it is possible to obtain a semiconductor chip 40 in which at least the bump-forming surface 21a and the side surfaces are covered with the first cured resin film (r1). However, the back surface of the semiconductor chip 40 is exposed. Therefore, from the viewpoint of protecting the back surface of the semiconductor chip 40 and further improving the strength of the semiconductor chip 40, it is preferable to perform the above step (T).

[0125] More specifically, the above step (T) preferably includes the following step (T1) and step (T2) in this order. Step (T1): A step of attaching a second curable resin film (X2) to the backside of a wafer for manufacturing semiconductor chips. Step (T2): A step of curing the second curable resin film (X2) to form a second cured resin film (r2) In addition, in the step (T1), a second composite sheet (α2) having a laminated structure in which a second release sheet (Y2) and a second curable resin film (X2) are laminated may be used. In particular, the step (T1) is preferably a step of attaching the second composite sheet (α2) having a laminated structure in which a second release sheet (Y2) and a second curable resin film (X2) are laminated to the back surface of the semiconductor chip production wafer, with the second curable resin film (X2) serving as an attachment surface. In this case, the timing for peeling the second release sheet (Y2) from the second composite sheet (α2) may be between the step (T1) and the step (T2), or after the step (T2).

[0126] Here, when the second composite sheet (α2) is used in the step (T1), it is preferable that the release sheet (Y2) of the second composite sheet (α2) not only supports the second curable resin film (X2) but also functions as a dicing sheet. Furthermore, since the second composite sheet (α2) is attached to the back surface 21b of the semiconductor chip manufacturing wafer 30 with the first cured resin film (r1) in step (S4), the second release sheet (Y2) functions as a dicing sheet when dicing into individual pieces, making dicing easier.

[0127] Here, when step (S-BG) is followed by step (S3), step (T1) may be performed before step (S3), and then step (S3) and step (T2) may be performed simultaneously. That is, the first curable resin film (X1) and the second curable resin film (X2) may be cured simultaneously. This reduces the number of times the curing treatment is performed.

[0128] [Process (U)] One aspect of the method for producing a semiconductor chip of the present invention may further include the following step (U): Step (U): A step of removing the first cured resin film (r1) covering the top of the bump or the first cured resin film (r1) attached to a part of the top of the bump to expose the top of the bump. The exposure process for exposing the tops of the bumps may be, for example, an etching process such as a wet etching process or a dry etching process. Here, the dry etching process may be, for example, a plasma etching process. If the tops of the bumps are not exposed on the surface of the protective film, the exposing process may be performed to recede the protective film until the tops of the bumps are exposed.

[0129] The timing of carrying out step (U) is not particularly limited as long as the first cured resin film (r1) is exposed, and it is preferable that it is after step (S3) and before step (S4), and that the release sheet (Y1) and backgrind sheet are not attached.

[0130] [Semiconductor chips] The semiconductor chip of the present invention has a bump-forming surface having bumps, and has a cured resin film formed by curing the curable resin film of the present invention on both the bump-forming surface and the side surfaces. The semiconductor chips of the present invention are obtained by cutting a cured resin film embedded in grooves formed in a semiconductor chip fabrication wafer along the planned division lines to separate the film. Because the cured resin film is a cured product of the above-mentioned curable resin film, the cutting debris generated when the cured resin film is cut along the planned division lines is small, making it less likely for the cutting debris to remain as residue. Therefore, the semiconductor chips of the present invention are less likely to have residue adhere to them and have excellent processing quality. [Example]

[0131] The present invention will now be described in detail with reference to examples, but the present invention is not limited to the following examples.

[0132] 1. Raw materials for producing curable resin film-forming compositions The raw materials used in the production of the curable resin film-forming composition are shown below. (1) Polymer component (A) (A)-1: Polyvinyl butyral having structural units represented by the following formulas (i)-1, (i)-2, and (i)-3 ("S-LEC BL-10" manufactured by Sekisui Chemical Co., Ltd., weight average molecular weight 25,000, glass transition temperature 59°C) (A)-2: Polyarylate ("Unifiner (registered trademark) M-2040" manufactured by Unitika Ltd.)

[0133] [ka]

[0134] (wherein l1 is approximately 28, m1 is 1 to 3, and n1 is an integer of 68 to 74.)

[0135] (Thermosetting component (B)) (2) Epoxy resin (B1) [Liquid epoxy resin] (B1)-1: Liquid modified bisphenol A epoxy resin (DIC Corporation, "Epicron EXA-4850-150", number average molecular weight 900, epoxy equivalent weight 450 g / eq) [Solid epoxy resin] (B1)-2: Naphthalene-type epoxy resin (DIC Corporation, "Epicron HP-4710", epoxy equivalent 170 g / eq) (B1)-3: Naphthalene-type epoxy resin (DIC Corporation, "Epicron HP-5000", epoxy equivalent: 252 g / eq) (B1)-4: Fluorene skeleton epoxy resin (OGSOL CG500 manufactured by Osaka Gas Chemicals Co., Ltd., epoxy equivalent weight 300 g / eq)

[0136] (3) Heat curing agent (B2) (B2)-1: O-cresol novolac resin (DIC Corporation, "Phenolite KA-1160," hydroxyl equivalent: 117 g / eq)

[0137] (4) Curing accelerator (C) (C)-1:2-Phenyl-4,5-dihydroxymethylimidazole ("Curezol 2PHZ-PW" manufactured by Shikoku Chemicals Corporation)

[0138] (5) Filler (D) (D)-1: Spherical silica modified with epoxy groups ("Admanano YA050C-MKK" manufactured by Admatechs Co., Ltd., average particle size 50 nm)

[0139] (6) Additives (G) (G)-1: Surfactant (acrylic polymer, BYK "BYK-361N") (G)-2: Silicone oil (aralkyl-modified silicone oil, "XF42-334" manufactured by Momentive Performance Materials Japan, LLC)

[0140] 2. Examples 1 to 5 and Comparative Examples 1 and 2 2-1. Example 1 (1) Preparation of thermosetting resin film-forming composition (1) Polymer component (A)-2 (100 parts by mass), epoxy resin (B1)-1 (295 parts by mass), epoxy resin (B1)-4 (210 parts by mass), heat curing agent (B2)-1 (162 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (199 parts by mass), additive (G)-1 (22 parts by mass), and additive (G)-2 (2 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23 ° C. to obtain a thermosetting resin film-forming composition (1) with a total concentration of all components other than the solvent of 60% by mass. Note that the amounts of all components other than the solvent shown here are the amounts of the target product excluding the solvent.

[0141] (2) Manufacturing of thermosetting resin films A release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) made of polyethylene terephthalate, one side of which had been treated for release by silicone treatment, was used. The composition (1) obtained above was applied to the release-treated surface, and the coating was dried by heating at 120°C for 2 minutes to form a thermosetting resin film with a thickness of 45 μm.

[0142] 2-2. Examples 2 to 5 and Comparative Examples 1 and 2 A thermosetting resin film having a thickness of 45 μm was formed in the same manner as in Example 1, except that either the type or the amount of the components blended during the production of the thermosetting resin film-forming composition (1) was changed so that the types and contents of the components contained in the thermosetting resin film-forming composition (1) were as shown in Table 1 below. In Table 1, the notation "-" in the column for contained components means that the thermosetting resin film-forming composition does not contain that component.

[0143] [Table 1]

[0144] 3. Evaluation The thermosetting resin film obtained above was subjected to the following evaluations, and the results are shown in Table 2.

[0145] 3-1. Calculation of crosslink density The crosslink density was calculated according to the following formula.

[0146]

number

[0147] 3-2. Measurement of breaking energy (E) and breaking elongation (T), and calculation of T x E Five 45 μm-thick thermosetting resin films were laminated at 60°C to prepare a 225 μm-thick laminated film. This laminated film was heat-cured at 130°C and 0.5 MPa for 240 minutes, then placed on a dicing tape ("D-676H" manufactured by Lintec Corporation) and ground using a dicing machine ("DFD6362" manufactured by Disco Corporation) at a rotation speed of 30,000 rpm, a feed rate of 10 mm / sec, and a cutting depth of 20 μm to prepare test pieces measuring 3 mm wide and 100 mm long. The test piece was placed in a Tensilon with a thermostatic chamber (Tensilon universal material testing machine ("RTG-1210" manufactured by Orientec Co., Ltd.), thermostatic chamber for testing machine ("TKC-R3T-GS" manufactured by Orientec Co., Ltd.)) so that the chuck length was 50 mm, and the breaking elongation (T) and breaking energy (E) were measured at a temperature of 70°C and a speed of 200 mm / min. T×E was calculated from the obtained values ​​of breaking elongation (T) and breaking energy (E).

[0148] 3-3. Measurement of Gc1 and Gc300 of curable resin film and calculation of X value Twenty thermosetting resin films with a thickness of 45 μm were prepared. These thermosetting resin films were then laminated, and the resulting laminated film was cut into a disk with a diameter of 25 mm to prepare a thermosetting resin film test piece with a thickness of 900 μm. The location where the test piece was to be placed in the viscoelasticity measuring device ("MCR301" manufactured by Anton Paar) was kept warm at 80°C in advance, and the test piece of the thermosetting resin film obtained above was placed on this location, and the test piece was fixed to the location by pressing a measuring jig against the top surface of the test piece. Next, the storage modulus Gc of the test piece was measured by increasing the strain generated in the test piece stepwise from 0.01% to 1000% under the conditions of a temperature of 90°C and a measurement frequency of 1 Hz. The X value was calculated from the measured values ​​of Gc1 and Gc300.

[0149] 3-4. Evaluation of groove filling and seepage from wafer edges (1) Preparation of wafers for semiconductor chip production A 12-inch silicon wafer (750 μm thick) was used as the wafer for semiconductor chip fabrication, with the planned dividing lines cut in half. The width of the half-cut portion of the silicon wafer (the width of the groove) was 60 μm, and the depth of the groove was 230 μm.

[0150] (2) Evaluation method One side of a 45 μm thick thermosetting resin film was attached to the front side (half-cut surface) of the semiconductor chip fabrication wafer while pressing under the following conditions. - Application device: BG tape laminator (Rintec Corporation "RAD-3510F / 8") - Application pressure: 0.5MPa Application time: 43 seconds Application speed: 7mm / sec Application temperature: 80℃ Roller application height: -200mm Next, the semiconductor chip fabrication wafer with the attached thermosetting resin film was heated at a temperature of 130°C and a pressure of 0.5 MPa for 4 hours to harden the film and form a cured resin film. The semiconductor chip fabrication wafer was then cut from the half-cut surface to the back surface, and the embedding of the cured resin film into the grooves of the half-cut portions was observed using an optical microscope (Keyence Corporation, "VHX-100"). The presence or absence of seepage of the cured resin film from the edge of the wafer was also visually observed. The evaluation criteria for embeddability were as follows. S: No distortion is observed in the shape of the cured resin film, and the embedding property is the best. A: Although some distortion is observed in the shape of the cured resin film near the entrance of the groove, the embedding property is good. B: Poor embedding ability.

[0151] 3-5. Evaluate processing quality and check for the presence of retained material Five 45 μm-thick thermosetting resin films were laminated at 60°C and then cut into a 5 cm x 5 cm piece to prepare a 225 μm-thick laminated film. This laminated film was heat-cured at 130°C and 0.5 MPa for 240 minutes and then attached to dicing tape ("D-676H" manufactured by Lintec Corporation). The surface of the laminated film opposite the dicing tape was then ground using a dicing machine ("DFD6362" manufactured by Disco Corporation, blade: ZH05-SD1500-N1-50-27HECC, blade width: 0.03 mm) at a rotation speed of 30,000 rpm, a feed rate of 30 mm / sec, and a cutting depth of 20 μm, resulting in individual chips (hereinafter simply referred to as "chips") consisting of only the resin and measuring 2 mm x 2 mm. The surface of the laminated film on which the dicing lines were formed (the surface opposite to the dicing tape surface) was observed with a digital microscope (Keyence Corporation, "VHX-7000") to check for the presence of retained material on the dicing lines. The results are shown in "Retained material - surface side" in Table 2.

[0152] Next, a UV irradiation device ("RAD-2000F / 12" manufactured by Lintec Corporation) was used to irradiate the back surface of the laminated film (the surface to which the dicing tape was attached) with an illuminance of 230 mW / cm. 2 , light intensity 190mJ / cm 2 After irradiating with ultraviolet light under the conditions, the laminate film was transferred with the front surface (the surface opposite to the dicing tape attached surface) facing toward a semiconductor processing tape ("D-210" manufactured by Lintec Corporation). The chip surrounded by the dicing lines was observed from the back surface (dicing tape attached surface) of the laminate film transferred to the semiconductor processing tape using a digital microscope ("VHX-7000" manufactured by Keyence Corporation), and the presence or absence of distortion of the chip due to retained material was evaluated according to the following criteria. The percentage of distortion of the chip was calculated using the following formula. The results are shown in Table 2 under "Retained material - back side."

[0153]

number

[0154] In the above formula, Ha is the blade width (mm) of the blade used for dicing, which was 0.03 mm in this evaluation, and Hb is the kerf width (mm) of the dicing line measured using the following procedure. The distance between each chip (called the kerf width) between the chip separated by the dicing machine and the chip adjacent to it on one side was observed using a digital microscope, and the narrowest distance was measured. This was repeated for four chips, and the average value (mm) was calculated.

[0155] [Evaluation criteria for the back surface of the laminated film] 0: No distortion is observed on the chip dicing line. 1: Distortion of 1% or more and less than 20% was observed on the dicing line of the chip. 2: Distortion of 20% or more but less than 50% was observed on the dicing line of the chip. 3: Distortion of 50% or more was observed on the chip dicing line.

[0156] Next, a UV irradiation device ("RAD-2000F / 12" manufactured by Lintec Corporation) was used to irradiate the laminated film from the semiconductor processing tape side with an illuminance of 230 mW / cm. 2 , light intensity 190mJ / cm 2 After irradiating with ultraviolet light under the conditions, the chip surrounded by the dicing lines was picked up. The side of the chip was observed using a scanning electron microscope (SEM, Keyence Corporation's "VE-9700") from a direction perpendicular to the top surface of the chip at an angle of 45°, and the processing quality was evaluated according to the following criteria. The contamination rates at the chip corners and on the chip side were calculated using the following formula.

[0157]

number

[0158] In the above formula, Ta is the thickness (μm) of the chip after singulation, which is 225 μm in this evaluation, and Tb is the average width (μm) of the area where cutting debris or residual material adheres at the corner of the chip after singulation (however, perpendicular to the chip surface) measured for four chips.

[0159]

number

[0160] In the above formula, Ta is the thickness (μm) of the chip after singulation, which is 225 μm in this evaluation, and Tc is the average width (μm) of the area where cutting debris or residual material adheres on the side of the chip after singulation (however, perpendicular to the chip surface) measured for four chips.

[0161] [Evaluation of chip angle and side surface] Evaluation (1): The side of the tip was observed to check for protrusions due to the adhesion of cutting chips or remaining material.

[0162] Evaluation (2): Contamination of chip corners 0: No protrusions due to cutting chips or retained material are observed at the corners of the chip. 1: Protrusions due to cutting debris or remaining material are found at the corners of the chips, and the protrusions contaminate the corners of the chips by 1% or more but less than 20%. 2: Protrusions due to cutting debris or remaining material are found at the corners of the chips, and the protrusions contaminate 20% to less than 50% of the corners of the chips. 3: Protrusions due to cutting debris or remaining material are found at the corners of the chips, and the protrusions contaminate 50% or more of the corners of the chips.

[0163] Evaluation (3): Contamination on the chip side 0: No cutting debris or residue was observed on the side of the tip. 1: Cutting debris or accumulated material is observed on the chip side surface, and the cutting debris or accumulated material contaminates 1% or more but less than 20% of the chip side surface. 2: Cutting debris or accumulated material is observed on the side of the chip, and the cutting debris or accumulated material contaminates 20% or more but less than 50% of the chip side. 3: Cutting debris or accumulated material is observed on the side of the chip, and the cutting debris or accumulated material contaminates 50% or more of the side of the chip.

[0164] [Table 2]

[0165] From Examples 1 to 5, the breaking energy at 70°C after curing was 10.0 MJ / m 3 It can be seen that by using the following curable resin film to form a protective film for a semiconductor chip, it is possible to obtain a semiconductor chip with excellent processing quality, with less adhesion of cutting debris and residual matter. [Explanation of symbols]

[0166] 10,20 composite sheet 30 Wafers for semiconductor chip manufacturing 40 Semiconductor Chips 1,11 Peel-off sheet 2,12 Curable resin film 3,13 Base material 4,14 Peeling layer 15 Middle Class 21 Semiconductor wafers 21a Bump forming surface 21b Back side 22 Bump 23 Groove X1 First hardening resin film Y1 First release sheet r1 First cured resin film α1 First Composite Sheet X2 Secondary curing resin film Y2 Second release sheet r2 Second cured resin film α2 Secondary Composite Sheet

Claims

1. A curable resin film used to form a cured resin film as a protective film on both a bump-forming surface and a side surface of a semiconductor chip having a bump-forming surface, The breaking energy of the curable resin film at 70°C after curing is 10.0 MJ / m ３ The following is a curable resin film.

2. The curable resin film according to claim 1 , having a thickness of 30 μm or more.

3. A composite sheet having a laminated structure in which the curable resin film according to claim 1 or 2 and a release sheet are laminated.

4. The composite sheet according to claim 3 , wherein the release sheet has a substrate and a release layer, the release layer facing the curable resin film.

5. The composite sheet according to claim 4 , further comprising an intermediate layer between the substrate and the release layer.

6. 5. The composite sheet according to claim 4, wherein the release layer is formed from a composition containing an ethylene-vinyl acetate copolymer.

7. The method includes the following steps (S1) to (S4) in this order: Step (S1): A step of preparing a semiconductor chip manufacturing wafer having a bump-forming surface on which grooves as planned division lines are formed so as not to reach the rear surface of the semiconductor wafer. Step (S2): A step of pressing and pasting the curable resin film according to claim 1 or 2 onto the bump-formed surface of the semiconductor chip fabrication wafer, thereby covering the bump-formed surface of the semiconductor chip fabrication wafer with the curable resin film and embedding the curable resin film in the grooves formed in the semiconductor chip fabrication wafer. Step (S3): A step of curing the curable resin film to obtain a wafer for producing semiconductor chips with a cured resin film. Step (S4): A step of dividing the wafer for producing semiconductor chips with the cured resin film along the planned dividing lines to obtain semiconductor chips in which at least the bump-forming surface and side surfaces are covered with the cured resin film. The method for manufacturing a semiconductor chip further comprises 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): Step (S-BG): Grinding the back surface of the semiconductor chip fabrication wafer

8. A semiconductor chip having a bump-forming surface with bumps, the semiconductor chip having a cured resin film formed by curing the curable resin film according to claim 1 on both the bump-forming surface and a side surface.

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