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. An elongation at break at 70°C of the curable resin film after curing is equal to or less than 85%.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 a semiconductor chip. More specifically, the present invention relates to a curable resin film, a composite sheet comprising the curable resin film, a semiconductor chip having a curable resin film as a protective film provided by utilizing these, 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 the face-down method, a semiconductor chip with bumps on its circuit surface and a substrate for mounting the semiconductor chip are stacked so that the circuit surface of the semiconductor chip and the substrate face each other, thereby mounting the semiconductor chip onto the substrate. Typically, these semiconductor chips are obtained by slicing a semiconductor wafer, which has bumps on its circuit surface, into individual pieces.

[0003] Semiconductor wafers with bumps may have a protective film applied to protect the junction between the bump and the semiconductor wafer (hereinafter also referred to as the "bump neck"). For example, in Patent Documents 1 and 2, a laminate in which a support substrate, an adhesive layer, and a thermosetting resin layer are stacked in this order is pressed and attached to the bump-forming surface of a semiconductor wafer having bumps, with the thermosetting resin layer as the bonding surface, and then a protective film is formed by heating and curing the thermosetting resin layer. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-092594 [Patent Document 2] Japanese Patent Publication No. 2012-169484 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In the methods described in Patent Documents 1 and 2 above, after forming a protective film on a bumped wafer, the bumped wafer is diced together with the protective film to obtain individual semiconductor chips. When a bumped wafer is diced together with a protective film in this way, the cut surface of the protective film by the dicing blade has good processing quality. However, as a result of diligent research by the inventors, it was discovered 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 equipped with bumps, the processing quality of the cut surface of the protective film by the dicing blade deteriorates.

[0006] The present invention has been made in view of the above problems, and aims to provide a curable resin film that is used to form a curable 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 with bumps, and which exhibits excellent processing quality after grinding and fragmentation, a composite sheet comprising the curable resin film, a semiconductor chip, and a method for manufacturing the semiconductor chip. [Means for solving the problem]

[0007] The inventors of the present invention conducted intensive studies to solve the above problems and found 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 is reduced because only the protective film is cut without cutting the wafer. To resolve this problem, the inventors focused on the physical properties of the curable resin film used to form the protective film and conducted further intensive studies. As a result, they found that the above problems can be solved by using a curable resin film in which the elongation at break at 70°C after curing is below a specific value for forming a protective film on a semiconductor chip, and thus completed the present invention.

[0008] In other words, the present invention relates to the following: [1] A curable resin film used to form a curable 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, A curable resin film having a break elongation of 85% or less at 70°C after curing. [2] The curable resin film according to [1] above, wherein the product of the elongation at break and the energy at break at 70°C after curing is 1000 or less. [3] A curable resin film according to [1] or [2] above, having a thickness of 30 μm or more. [4] A composite sheet having a laminated structure in which a curable resin film described in any of [1] to [3] above and a release sheet are laminated together. [5] The composite sheet according to [4] above, wherein the release sheet comprises a base material and a release layer, the release layer facing the curable resin film. [6] The composite sheet according to [5], further comprising an intermediate layer between the substrate and the release layer. [7] The composite sheet according to [5] or [6], wherein the release layer is a layer formed from a composition containing an ethylene-vinyl acetate copolymer. [8] The following steps (S1) to (S4) are included in this order: Step (S1): A step to prepare a semiconductor wafer for manufacturing semiconductor chips, in which grooves, which are intended to be division lines, are formed on the bump-forming surface of a semiconductor wafer having bumps, without reaching the back surface. Step (S2): A step in which a curable resin film described in any of [1] to [3] above is pressed and attached to the bump-forming surface of the semiconductor chip manufacturing wafer, thereby covering the bump-forming surface of the semiconductor chip manufacturing wafer with the curable resin film, and embedding the curable resin film into the grooves formed in the semiconductor chip manufacturing wafer. Step (S3): A step to cure the curable resin film to obtain a wafer for manufacturing semiconductor chips with a cured resin film. Step (S4): Dicing the wafer for manufacturing the semiconductor chip with the cured resin film along the planned dicing lines to obtain semiconductor chips, at least the bump formation surface and the side surfaces of which are covered with the cured resin film. Furthermore, a method for manufacturing a semiconductor chip, including 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): A step of grinding the back surface of the wafer for manufacturing the semiconductor chip. [9] A semiconductor chip having a cured resin film formed by curing the curable resin film according to any one of [1] to [3] on both the bump formation surface and the side surfaces of the semiconductor chip having the bump formation surface provided with bumps. [Advantages of the Invention]

[0009] According to the present invention, there can be provided a curable resin film used for forming a cured resin film as a protective film on both the bump formation surface and the side surfaces of a semiconductor chip having a bump formation surface provided with bumps, and being excellent in processing quality after grinding and dicing, a composite sheet including the curable resin film, a semiconductor chip, and a method for manufacturing the semiconductor chip. [Brief Description of the Drawings]

[0010] [Figure 1] It is a schematic cross-sectional view showing the configuration of a composite sheet in an embodiment of the present invention. [Figure 2] It is a schematic cross-sectional view showing the configuration of a composite sheet in another embodiment of the present invention. [Figure 3] It is a schematic cross-sectional view showing an example of a wafer for manufacturing a semiconductor chip prepared in the step (S1). [Figure 4] It is a view showing an outline of the step (S2). [Figure 5] It is a view showing an outline of the step (S3). [Figure 6] It is a view showing an outline of the step (S4). [Figure 7]This diagram shows a schematic of the process (S-BG). [Modes for carrying out the invention]

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

[0012] [Curing resin film] The curable resin film of the present invention is a curable resin film used to form a curable 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 equipped with bumps, wherein the elongation at break at 70°C after curing of the curable resin film is 85% or less. If the elongation at break of the curable resin film at 70°C after curing exceeds 85%, then during the semiconductor chip manufacturing process, when the curable resin film is embedded in the grooves formed in the semiconductor chip wafer and the cured resin film is cut along the planned cutting line, deformation due to elongation of the cured resin film caused by frictional heat and the generation of cutting debris are likely to occur. As a result, deformation of the cut surface of the semiconductor chip wafer and adhesion of cutting debris to the cut surface may occur, potentially reducing the processing quality of the resulting semiconductor chip. From this viewpoint, the elongation at break is preferably 65% ​​or less, more preferably 45% or less, even more preferably 40% or less, even more preferably 30% or less, and even more preferably 20% or less. Furthermore, the lower limit of the elongation at break is not particularly limited, but may be 1% or more, or 3% or more. The above-mentioned elongation at break can be adjusted by adjusting either or both of the types and amounts of components contained in the curable resin that forms the curable resin film. The above-mentioned elongation at break can be measured by the method described in the examples.

[0013] The curable resin film of the present invention preferably has a breaking energy of 10.0 MJ / m² at 70°C after curing. 3 The following, and more preferably 9.0 MJ / m 3 The following, and more preferably 7.0 MJ / m 3 The following, and more preferably 6.0 MJ / m 3 The following, and more preferably 3.0 MJ / m 3The following applies: When the fracture energy is below the above value, in the semiconductor chip manufacturing process, when the curable resin film is embedded in the grooves formed in the semiconductor chip wafer and the cured resin film formed by curing the curable resin film is cut along the planned division line, the amount of cutting debris generated becomes smaller, and the cutting debris is less likely to remain as residue in the grooves. As a result, residue is less likely to adhere to the cut surface of the semiconductor chip wafer, and a semiconductor chip with excellent processing quality can be obtained. Furthermore, the lower limit of the fracture energy is not particularly limited, but is preferably 0.1 MJ / m 3 That's all. The above-mentioned fracture energy can be adjusted by adjusting either or both of the types and amounts of components contained in the curable resin that forms the curable resin film. The fracture energy mentioned above can be measured by the method described in the examples.

[0014] The curable resin film of the present invention preferably has a product of the elongation at break (T) and the energy at break (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 the elongation at break (T) and the energy at break (E) is less than or equal to the above value, cutting debris and retained material are suppressed in the semiconductor chip manufacturing process, and the processing quality of the resulting semiconductor chip can be improved. Furthermore, the lower limit of the product of the elongation at break and the energy at break is not particularly limited, but may be 1 or more.

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

[0016] From the viewpoint of forming a protective film with excellent coating properties, the upper limit of the X value defined in the above requirement (I) is preferably 5,000 or less, more preferably 2,000 or less, still more preferably 1,000 or less, even more preferably 500 or less, still even more preferably 300 or less, still more preferably 100 or less, and even more preferably 70 or less. Also, from the viewpoint of making the embedding property into the groove of the wafer for manufacturing a semiconductor chip better, the lower limit of the X value defined 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 coating properties, Gc1 is preferably 1×10 2 ~1×10 6 Pa, more preferably 2×10 3 ~7×10 5 Pa, and still more preferably 3×10 3 ~5×10 5 Pa.

[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, after the bump penetrates the curable resin film, from the viewpoint of improving the embedding ability of the curable resin film into the bump base and into the grooves of the wafer for semiconductor chip fabrication, 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] The curable resin film of the present invention preferably has a crosslinking 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, from the viewpoint of processing quality of chips after processing and reduction of retained material. The above crosslink density can be calculated using 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 of grooves. Furthermore, the thickness of the curable resin film 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 above thickness can be adjusted as needed, as the volume of resin to be filled changes depending on the depth and width of the grooves provided in the semiconductor chip wafer. Here, "thickness of the curable resin film" refers to the total thickness of the curable resin film. For example, the thickness of a curable resin film consisting of multiple layers refers to the total thickness of all the 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 manufacturing wafer and to fill grooves formed in the semiconductor chip manufacturing wafer, and forms a curable resin film by heating or energy ray irradiation. The curable resin film may be a thermosetting resin film that hardens by heating, or an energy ray curable resin film that hardens 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 following describes thermosetting resin films.

[0022] (Thermosetting resin film) The above thermosetting resin film contains a polymer component (A) and a thermosetting component (B). The above thermosetting resin film is formed, for example, from a thermosetting resin composition containing a polymer component (A) and a thermosetting component (B). Polymeric component (A) is a component that can be considered to have been formed by a polymerization reaction of polymerizable compounds. Thermosetting component (B) is a component that can undergo a curing (polymerization) reaction triggered by heat. This curing (polymerization) reaction also includes polycondensation reactions. In this specification, "the total amount of each component in the thermosetting resin composition" is synonymous with "the amount of each component in the thermosetting resin film formed from the thermosetting resin composition."

[0023] [Potassium component (A)] The thermosetting resin film and thermosetting resin composition contain polymer component (A). Polymer component (A) is a polymer compound used to impart film-forming properties, flexibility, and other characteristics to a thermosetting resin film. Polymer component (A) may be used alone or in combination of two or more types. When using two or more types of polymer component (A) in combination, the combination and ratio can be arbitrarily selected.

[0024] Examples of polymer components (A) include acrylic resins (resins having (meth)acryloyl groups), polyarylate resins, polyvinyl acetal, polyester, 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 acetal are preferred.

[0025] Examples of acrylic resins include well-known acrylic polymers. The weight-average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, more preferably 300,000 to 1,500,000, and even more preferably 500,000 to 1,000,000. Having a weight-average molecular weight of acrylic resin above the lower limit mentioned above makes it easier to improve the dimensional stability (stable over time during storage) of the thermosetting resin film. Furthermore, having a weight-average molecular weight of acrylic resin below the upper limit makes it easier for the thermosetting resin film to conform to the uneven surface of the substrate, thus suppressing the formation of voids between the substrate and the thermosetting resin film. Therefore, the coverage of the bump-forming surface of semiconductor wafers is improved, and the ability to fill grooves is also enhanced.

[0026] The glass transition temperature (Tg) of acrylic resins is preferably -60 to 70°C, more preferably -40 to 50°C, and even more preferably -30 to 30°C, from the viewpoint of the adhesiveness and handling properties of the 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, etc.

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

[0029] Acrylic resins may also be copolymerized with one or more monomers selected from, for example, (meth)acrylic acid esters, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide.

[0030] The monomers constituting the acrylic resin may be a single type or two or more types. If the monomers constituting the acrylic resin are two or more types, their combination and ratio can be arbitrarily selected.

[0031] Examples of polyarylate resins in polymer component (A) include known resins, such as those whose basic structure is the polycondensation of a divalent phenol with a dibasic acid such as phthalic acid or a carboxylic acid. Among these, polycondensates of bisphenol A and phthalic acid, poly-4,4'-isopropylidenediphenylene terephthalate / isophthalate copolymers, and their derivatives are preferred.

[0032] Examples of the polyvinyl acetal in polymer component (A) include those that are well known. Among 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 constituent units represented by the following formulas (i)-1, (i)-2, and (i)-3.

[0033] [ka]

[0034] (In the formula, l, m, and n are each an independent integer greater than or equal to 1.)

[0035] The weight-average molecular weight (Mw) of polyvinyl acetal is preferably 5,000 to 200,000, and more preferably 8,000 to 100,000. Having a weight-average molecular weight of polyvinyl acetal above the lower limit makes it easier to improve the shape stability (stable over time during storage) of the thermosetting resin film. Furthermore, having a weight-average molecular weight of polyvinyl acetal below the upper limit makes it easier for the thermosetting resin film to conform to the uneven surface of the adherend, for example, making it easier to suppress the generation of voids between the adherend and the thermosetting resin film. Therefore, the coverage of the bump-forming surface of the semiconductor wafer is improved, and the ability to embed in grooves is also improved.

[0036] The glass transition temperature (Tg) of polyvinyl acetal is preferably 40 to 80°C, and more preferably 50 to 70°C, from the viewpoint of film-forming properties of the curable resin film and the ability of the bump top to protrude. Herein, in this specification, "bump top protrusion" refers to the ability of a bump to penetrate a thermosetting resin film for protective film formation when the film is applied to a bump-equipped wafer, and is also called bump top penetration.

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

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

[0039] Polymer component (A) may also correspond to thermosetting component (B). In this invention, if a thermosetting resin composition contains components that correspond to both polymer component (A) and thermosetting component (B), the thermosetting resin composition is deemed to contain both polymer component (A) and thermosetting component (B).

[0040] [Thermosetting component (B)] The thermosetting resin film and thermosetting resin composition contain thermosetting component (B). Thermosetting component (B) is a component that cures the thermosetting resin film to form a hard, cured resin film. The thermosetting component (B) may be used alone or in combination of two or more types. If there are two or more types of thermosetting component (B), their combination and ratio can be arbitrarily selected.

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

[0042] Epoxy thermosetting resins consist of an epoxy resin (B1) and a thermosetting agent (B2). Epoxy thermosetting resins may be used individually or in combination of two or more types. When two or more epoxy thermosetting resins are used, their combination and ratio can be arbitrarily selected.

[0043] <Epoxy resin (B1)> While the epoxy resin (B1) is not particularly limited, it is preferable to use a combination of an epoxy resin that is solid at room temperature (hereinafter also referred to as a solid epoxy resin) and an epoxy resin that is liquid at room temperature (hereinafter also referred to as a liquid epoxy resin) from the viewpoint of making it easier to exhibit the effects of the present invention. 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. Examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, glycidyl ester type epoxy resin, biphenyl type epoxy resin, and phenylene skeleton type epoxy resin. Among these, bisphenol A type epoxy resin is preferred. Liquid epoxy resin may be used alone or in combination of two or more types. When two or more types of liquid epoxy resin are used, their combination and ratio can be arbitrarily selected.

[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. Examples include biphenyl-type epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, orthocresol novolac epoxy resin, dicyclopentadiene-type epoxy resin, naphthalene-type epoxy resin, anthracene-type epoxy resin, and fluorene skeleton-type epoxy resin. Among these, naphthalene-type epoxy resin and fluorene skeleton-type epoxy resin are preferred, and fluorene skeleton-type epoxy resin is more preferred. Solid epoxy resins may be used individually or in combination of two or more types. When two or more solid epoxy resins are used, their combination and ratio can be arbitrarily selected.

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

[0048] The ratio of the liquid epoxy resin (x) content to the solid epoxy resin (y) content [(x) / (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 even more preferably 0.5 to 5.0. When the above ratio [(x) / (y)] is within the above range, it becomes easier to adjust the elongation at break at 70°C after curing of the curable resin film to be less than or equal to the above value.

[0049] The number-average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoint of the curability of the thermosetting resin film 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] <Thermosetting agent (B2)> The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1). Examples of the thermosetting agent (B2) include compounds having two or more functional groups capable of reacting with epoxy groups in one molecule. Examples of the above functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups in which an acid group has been converted into an anhydride. It is preferable that the functional group is a phenolic hydroxyl group, an amino group, or a group in which an acid group has been converted into an anhydride, and it is more preferable that the functional group is a phenolic hydroxyl group or an amino group.

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

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

[0053] The thermosetting agent (B2) may be used alone or in combination of two or more types. If there are two or more types of thermosetting agent (B2), their combination and ratio can be arbitrarily selected.

[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, based on the content of 100 parts by mass of the epoxy resin (B1). When the content of the thermosetting agent (B2) is above the lower limit, the curing of the thermosetting resin film proceeds more easily. Furthermore, when the content of the thermosetting agent (B2) is below the upper limit, the moisture absorption rate of the thermosetting resin film is reduced, and the reliability of the package obtained using the thermosetting resin film is further improved.

[0055] In a thermosetting resin composition, the content of the thermosetting component (B) (total content of epoxy resin (B1) and thermosetting agent (B2)) is preferably 200 to 3000 parts by mass, more preferably 300 to 2000 parts by mass, even more preferably 400 to 1000 parts by mass, and even more preferably 500 to 800 parts by mass, based on 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 thermosetting resin composition may contain a curing accelerator (C). Curing accelerator (C) is an ingredient used to adjust the curing rate of a thermosetting resin composition. Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organophosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate. Among these, imidazoles are preferred, and 2-phenyl-4,5-dihydroxymethylimidazole is more preferred, from the viewpoint of making it easier to exhibit the effects of the present invention.

[0057] The curing accelerator (C) may be used alone or in combination of two or more types. If there are two or more types of curing accelerator (C), their combination and ratio can be arbitrarily selected.

[0058] In a thermosetting resin composition, when a curing accelerator (C) is used, the content of the curing accelerator (C) is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the content of the thermosetting component (B). When the content of the curing accelerator (C) is above the lower limit, the effects of using the curing accelerator (C) are more easily obtained. Furthermore, when the content of the curing accelerator (C) is below the upper limit, for example, the effect of suppressing the migration and segregation of highly polar curing accelerators (C) to the adhesive interface side with the adherend in the thermosetting resin film under high temperature and high humidity conditions is enhanced, and the reliability of the package obtained using the thermosetting resin film is further improved.

[0059] [Filler (D)] The thermosetting resin film and thermosetting resin composition may contain a filler (D). By including filler (D), it becomes easier to adjust the thermal expansion coefficient of the cured resin film obtained by curing the thermosetting resin film to an appropriate range, thereby further improving the reliability of packages obtained using the thermosetting resin film. In addition, by including filler (D) in the thermosetting resin film, it is also possible to reduce the moisture absorption rate of the cured resin film and improve its heat dissipation.

[0060] The filler (D) may be either an organic filler or an inorganic filler, but an inorganic filler is preferred. Preferred inorganic fillers include, for example, powders such as silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride; beads formed from these inorganic fillers in a spherical shape; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers. Among these, from the viewpoint of making it easier to exhibit 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 types. If there are two or more types of filler (D), their combination and ratio can be selected arbitrarily.

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

[0063] The average particle size 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 above average particle size is calculated by measuring the outer diameter of a single particle at several locations and determining the average value.

[0064] [Energy ray curable resin (E)] The thermosetting resin film and thermosetting resin composition may contain an energy ray curable resin (E). The thermosetting resin film contains an energy-ray curable resin (E), allowing its properties to be altered by irradiation with energy rays.

[0065] Energy-ray curable resin (E) is obtained by polymerizing (curing) an energy-ray curable compound. Examples of energy-ray curable compounds 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-like 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 include aliphatic skeleton-containing (meth)acrylates; cyclic aliphatic 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-mentioned polyalkylene glycol (meth)acrylates; itaconic acid oligomers, etc.

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

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

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

[0070] [Photopolymerization initiator (F)] When a thermosetting resin film and a 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) in order to efficiently advance the polymerization reaction of the energy ray curable resin (E).

[0071] Examples of photopolymerization initiators (F) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, 1,2-diphenylmethane, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 2-chloroanthraquinone.

[0072] The photopolymerization initiator (F) may be used alone or in combination of two or more types. If there are two or more types of photopolymerization initiator (F), their combination and ratio can be arbitrarily selected.

[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, based on the content of 100 parts by mass of the energy ray curable resin (E).

[0074] [Additive (G)] The thermosetting resin film and thermosetting resin composition may contain additive (G) as long as it does not impair the effects of the present invention. Additive (G) may be any known additive and can be arbitrarily selected depending on the purpose, and is not particularly limited. Preferred additives (G) include, for example, coupling agents, crosslinking agents, surfactants, plasticizers, antistatic agents, antioxidants, and gettering agents.

[0075] Additive (G) may be used individually or in combination of two or more types. If there are two or more general-purpose additives (G), their combination and ratio can be arbitrarily selected. The amount of additive (G) is not particularly limited and should be selected as appropriate depending on the purpose.

[0076] 〔solvent〕 The thermosetting resin composition preferably further contains a solvent. Thermosetting resin compositions containing solvents offer good handling properties. The solvent is not particularly limited, but preferred solvents include, for example, hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The solvent may be used alone or in combination of two or more types. If two or more solvents are used, their combination and ratio can be arbitrarily selected. The solvent is preferably methyl ethyl ketone or the like, as it allows for more uniform mixing of the components contained in the thermosetting resin composition.

[0077] (Method for preparing a thermosetting resin composition) A thermosetting resin composition is prepared by blending the various components that make it up. The order in which each component is added during formulation is not particularly limited, and two or more components may be added simultaneously. When using a solvent, the solvent may be used after pre-diluting the formulation by mixing it with any of the other components, or the solvent may be used by mixing it with the other components without pre-diluting them. The method of mixing each component during formulation is not particularly limited; it can be appropriately selected from known methods such as mixing by rotating a stirring bar or impeller, mixing using a mixer, or mixing by applying ultrasonic waves. The temperature and time during the addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and can be adjusted as appropriate, but a temperature of 15 to 30°C is preferred.

[0078] [Composite Sheet] 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. By using a 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 within the semiconductor chip manufacturing process. Figure 1 is a schematic cross-sectional view showing the configuration of a composite sheet in one embodiment of the present invention, and Figure 2 is a schematic cross-sectional view showing the configuration of a composite sheet in another embodiment of the present invention. The composite sheet 10 in Figure 1 comprises a release sheet 1 and a curable resin film 2 provided on the release sheet 1. The release sheet 1 comprises a base material 3 and a release layer 4, and the release layer 4 is provided so as to face the curable resin film 2. The composite sheet 20 in Figure 2 comprises 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 between the base material 13 and the release layer 14. Furthermore, a laminate in which the base material 13, the intermediate layer 15, and the release layer 14 are laminated in this order is suitable for use as a backgrind sheet. The following describes each layer that constitutes the release sheet used in the composite sheet of the present invention.

[0079] (base material) The base material is in the form of a sheet or film, and its constituent materials include, for example, the following various resins. Examples of resins constituting the base material include polyethylene 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 such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer (polymers obtained using ethylene as a monomer); and vinyl chloride-based resins such as polyvinyl chloride and vinyl chloride copolymer (using vinyl chloride as a monomer). Examples of resins obtained by [processing] include: polystyrene; polycycloolefin; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and all aromatic polyesters having aromatic cyclic groups as all constituent units; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethane; polyurethane acrylate; polyimide; polyamide; polycarbonate; fluororesin; polyacetal; modified polyphenylene oxide; polyphenylene sulfide; polysulfone; polyether ketone, etc. Furthermore, examples of resins constituting the base material include polymer alloys such as mixtures of the above-mentioned polyester and other resins. It is preferable that the polymer alloy of polyester and other resins contains a relatively small amount of the resin other than polyester. Furthermore, examples of resins constituting the base material include crosslinked resins obtained by crosslinking one or more of the above-mentioned resins; and modified resins such as ionomers using one or more of the above-mentioned resins.

[0080] The resin constituting the base material may be used alone or in combination of two or more types. If the base material is composed of two or more types of resin, the combination and ratio of these resins can be arbitrarily selected.

[0081] The base material may consist of only one layer (single layer) or two or more layers. If the base material consists of multiple layers, these layers may be identical or different from each other, and there are no particular limitations on the combination of these layers.

[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, "substrate thickness" refers to the total thickness of the substrate. For example, the thickness of a substrate consisting of multiple layers refers to the total thickness of all the layers that make up the substrate.

[0083] The base material should preferably have high thickness accuracy, that is, thickness variation should be suppressed regardless of the location. Among the constituent materials mentioned above, examples of materials with high thickness accuracy that can be used to construct such a base material 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 resin mentioned above, the base material may also contain various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, and plasticizers.

[0085] The substrate may be transparent or opaque, may be colored depending on the purpose, or may have other layers deposited on it.

[0086] The substrate can be manufactured by known methods. For example, a substrate containing a resin can be manufactured by molding a resin composition containing the above-mentioned resin.

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

[0088] The release layer may be a single layer or multiple layers (two or more). If the release layer consists of multiple layers, these layers may be identical or different, and there are no particular limitations on the combination of these layers.

[0089] The thickness of the release layer is preferably 3 to 50 μm, and more preferably 5 to 30 μm, from the viewpoint of releaseability and handling. Here, "thickness of the release layer" refers to the total thickness of the release layer, and for example, the thickness of a release layer consisting of multiple layers refers to the total thickness of all layers constituting the release layer.

[0090] (Middle class) The intermediate layer is in the form of a sheet or film, and its constituent material can be appropriately selected according to the purpose and is not particularly limited. For example, when the purpose is to suppress deformation of the cured resin film due to 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, which has high conformability to unevenness and further improves the adhesion of the intermediate layer.

[0091] The intermediate layer may consist of only one layer (single layer) or two or more layers. If the intermediate layer consists of multiple layers, these layers may be identical or different from each other, and there are no particular limitations on the combination of these layers.

[0092] The thickness of the intermediate layer can be adjusted as appropriate according to the height of the bumps on the semiconductor surface to be protected, but it is preferably 50 μm to 600 μm, more preferably 70 μm to 500 μm, and even more preferably 80 μm to 400 μm, in order to easily absorb the effects of relatively tall bumps. Here, "thickness of the intermediate layer" refers to the total thickness of the intermediate layer, and 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] (Method of manufacturing composite sheets) A composite sheet can be manufactured by sequentially laminating the above-mentioned layers in their corresponding positional relationships. For example, when manufacturing a composite sheet and laminating a release layer or intermediate layer onto a substrate, the release layer or intermediate layer can be laminated by coating the substrate with a release layer-forming composition or intermediate layer-forming composition, drying it as needed, or irradiating it with energy rays. Examples of coating methods 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 laminating a curable resin film on top of a release layer already laminated on a substrate, it is possible to directly form the curable resin film by coating the release layer with a thermosetting resin composition. Similarly, when laminating a release layer on top of an intermediate layer already laminated on a substrate, it is possible to directly form the release layer by coating the intermediate layer with a release layer forming composition.

[0095] Thus, when forming a continuous two-layer laminated structure using any of the compositions, it is possible to further coat the layer formed from the above composition to form a new layer. However, it is preferable that the second layer to be laminated is pre-formed on a separate release film using the above composition, and the exposed surface of this pre-formed layer opposite to the side in contact with the release film is bonded to the exposed surface of the remaining already formed layer to form a continuous two-layer laminated structure. In this case, it is preferable to coat the release treatment surface of the release film with the above composition. The release film may be removed as needed after the formation of the laminated structure.

[0096] [Manufacturing method for semiconductor chips] The semiconductor chip manufacturing method of the present invention broadly includes the steps of preparing a wafer for semiconductor chip manufacturing (S1), attaching a curable resin film (S2), curing the curable resin film (S3), and separating the wafer into individual pieces (S4), and further includes the step of grinding the back surface of the wafer for semiconductor chip manufacturing (S-BG).

[0097] In detail, the method for manufacturing a semiconductor chip of the present invention includes the following steps (S1) to (S4) in this order. Step (S1): A step to prepare a semiconductor wafer for semiconductor chip fabrication, in which grooves, which are intended to be division lines, are formed on the bump-forming surface of a semiconductor wafer having bumps, without reaching the back surface. Step (S2): The process of pressing and attaching the above-mentioned curable resin film to the bump-forming surface of the semiconductor chip manufacturing wafer, thereby covering the bump-forming surface of the semiconductor chip manufacturing wafer with the curable resin film, and embedding the curable resin film into the grooves formed in the semiconductor chip manufacturing wafer. Step (S3): A step to cure the above-mentioned curable resin film to obtain a wafer for manufacturing semiconductor chips with a cured resin film. Step (S4): A step to obtain a semiconductor chip in which at least the bump-forming surface and side surfaces are covered with the cured resin film, by separating the wafer for semiconductor chip fabrication along the planned division lines. Furthermore, the following step (S-BG) is included after step (S2) and before step (S3), after step (S3) and before step (S4), or during step (S4). Process (S-BG): A process for grinding the back surface of the wafer used for manufacturing the semiconductor chip.

[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 when the cured resin film formed by curing the curable resin film is cut along the planned division line, deformation due to elongation of the cured resin film due to frictional heat and the generation of cutting debris can be suppressed. As a result, deformation of the cut surface of the semiconductor wafer and adhesion of cutting debris to the cut surface are less likely to occur, and a semiconductor chip 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 manufacturing wafer, and the cured resin film formed by curing the curable resin film is cut along the planned division line, only the cured resin film is cut by the dicing blade, without cutting the semiconductor chip manufacturing wafer. Therefore, unlike when the semiconductor chip manufacturing wafer is cut together with the cured resin film, there is no effect of removing the cutting debris of the cured resin film along with the cutting debris of the semiconductor chip manufacturing wafer, nor is there an effect of preparing the abrasive grains when the semiconductor chip manufacturing wafer is cut by the dicing blade, which tends to reduce the processing quality of the cut surface of the cured resin film by the dicing blade. However, in the present invention, since the elongation at break at 70°C after curing of the curable resin film is adjusted to 85% or less, it is possible to obtain a semiconductor chip with excellent processing quality without reducing the processing quality of the cut surface of the cured resin film by the dicing blade. Furthermore, the manufacturing method including the above process yields a semiconductor chip in which not only the bump-forming surface but also the sides are covered with a cured resin film, resulting in a chip with excellent strength and resistance to peeling of the cured resin film, which acts as a protective layer. In this context, "coated" means that a cured resin film has been formed on at least the bump-forming surface and the side surface of a single semiconductor chip, following the shape of the semiconductor chip.

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

[0100] [Process (S1)] A schematic cross-sectional view of an example of a semiconductor wafer prepared in process (S1) is shown in Figure 3. In step (S1), a semiconductor wafer 30 for semiconductor chip fabrication is prepared, in which grooves 23, which are intended to be divided lines, are formed on the bump-forming surface 21a of a semiconductor wafer 21 having bumps 22, without reaching the back surface 21b.

[0101] The shape of the bump 22 is not particularly limited and can be any shape as long as it can be in contact with and fixed to electrodes on the substrate for chip mounting. For example, in Figure 3, the bump 22 is spherical, but the bump 22 may be a spheroid. This spheroid may be, for example, a spheroid stretched perpendicularly to the bump-forming surface 21a of the wafer 21, or a spheroid stretched horizontally to the bump-forming surface 21a of the wafer 21. The bump 22 may also be pillar-shaped.

[0102] The height of bump 22 is not particularly limited and can be changed as appropriate according to design requirements. For example, the particle size is 30 μm to 300 μm, preferably 60 μm to 250 μm, and more preferably 80 μm to 200 μm. Furthermore, "the height of the bump 22" refers to the height of the highest point of a single bump, relative to the bump-forming surface 21a.

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

[0104] Wafer 21 is a semiconductor wafer on which circuits such as wiring, capacitors, diodes, and transistors are formed on its surface. The material of the wafer is not particularly limited and includes, for example, silicon wafers, silicon carbide wafers, compound semiconductor wafers, glass wafers, and sapphire wafers.

[0105] The size of the wafer 21 is not particularly limited, but from the viewpoint of improving batch processing efficiency, it is usually 8 inches (200 mm in diameter) or larger, and preferably 12 inches (300 mm in diameter) or larger. The shape of the wafer 21 is not limited to circular, and may be square, rectangular, or other angular shapes. In the case of an angular wafer, from the viewpoint of improving batch processing efficiency, it is preferable that the length of the longest side of the wafer 21 is equal to or greater than the above size (diameter).

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

[0107] In process (S1), a plurality of grooves 23 are formed in a grid pattern on the bump-forming surface 21a of the semiconductor chip manufacturing wafer 30 prepared in process (S1) as planned division lines when the semiconductor chip manufacturing wafer 30 is divided into individual pieces. The plurality of grooves 23 are notches formed when the blade-first dicing method (Dicing Before Grinding) is applied, and are formed to a depth shallower than the thickness of the wafer 21, so that the deepest part of the groove 23 does 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 apparatus equipped with a dicing blade. The multiple grooves 23 should be formed so that the semiconductor chip to be manufactured has the desired size and shape. The size of the semiconductor chip is typically around 0.5mm × 0.5mm to 1.0mm × 1.0mm, but is not limited to this size.

[0108] The width of the groove 23 is preferably 10 μm to 2,000 μm, more preferably 30 μm to 1,000 μm, even more preferably 40 μm to 500 μm, and even more preferably 50 μm to 300 μm, from the viewpoint of improving the embedding ability of the curable resin film.

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

[0110] The semiconductor chip manufacturing wafer 30 prepared in process (S1) is subjected to process (S2).

[0111] [Process (S2)] A schematic of process (S2) is shown in Figure 4. In step (S2), a first-curable resin film (X1) is pressed and attached to the bump-forming surface 21a of the semiconductor chip wafer 30. Here, the first curable resin film (X1) may be used as a first composite sheet (α1) having a laminated structure in which the first release sheet (Y1) and the first curable resin film (X1) are laminated, from the viewpoint of ease of handling. When using the first composite sheet (α1), the first curable resin film (X1) of the first composite sheet (α1) is pressed and attached to the bump-forming surface 21a of the semiconductor chip manufacturing wafer 30, with the first curable resin film (X1) of the first composite sheet (α1) as the attachment surface.

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

[0113] The pressing force applied when attaching the first curable resin film (X1) to the semiconductor chip 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 curable resin film (X1) into the grooves 23. Furthermore, the pressing force applied when attaching the first curable resin film (X1) to the semiconductor chip wafer 30 may be appropriately varied from the initial stage to the final stage of attachment. For example, from the viewpoint of improving the embedding of the first curable resin film (X1) into the grooves 23, it is preferable to lower the pressing force at the initial stage of attachment and gradually increase it.

[0114] Furthermore, when attaching the first curable resin film (X1) to the semiconductor chip 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 embedding properties of the first curable resin film (X1) into the grooves 23. The specific 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. Furthermore, the heat treatment performed on the first curable resin film (X1) is not included in the curing treatment of the first curable resin film (X1).

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

[0116] [Process (S3)] A schematic of process (S3) is shown in Figure 5. In step (S3), the first curable resin film (X1) is cured to obtain a wafer 30 for semiconductor chip fabrication with the first curable resin film (r1) attached. The first cured resin film (r1), formed by curing the first curable resin film (X1), becomes stronger than the first curable resin film (X1) at room temperature. Therefore, the bump neck is well protected by forming the first cured resin film (r1).

[0117] The curing of the first curable resin film (X1) can be carried out by either thermal 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, "energy beam" means an electromagnetic wave or charged particle beam that has an energy quantum, and examples of such beams include ultraviolet rays and electron beams, with ultraviolet rays being preferred. When performing thermal curing, the curing temperature is preferably 90°C to 200°C, and the curing time is preferably 1 to 3 hours. The conditions for curing by energy ray irradiation are set appropriately depending on the type of energy ray used. For example, when using ultraviolet light, the illuminance is preferably 170 mw / cm². 2 ~250mw / cm 2 The light intensity is preferably 300 mJ / cm². 2 ~3,000 mJ / cm 2 That is the case. Here, in the process of curing the first curable resin film (X1) to form the first curable 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 trapped when filling the grooves 23 with the first curable resin film (X1) in step (S2).

[0118] [Process (S4)] A schematic of process (S4) is shown in Figure 6. In step (S4), the portion of the first cured resin film (r1) of the semiconductor chip manufacturing wafer 30 with the first cured resin film (r1) that is formed in the groove 23 is cut along the planned division line. Since the first cured resin film (r1) described above is formed by curing the curable resin film of the present invention, the elongation at break of the first cured resin film (r1) at 70°C satisfies the requirement of 85% or less. Therefore, in step (S4), when the portion of the first cured resin film (r1) formed in the groove 23 is cut along the planned division line, deformation due to elongation of the first cured resin film (r1) due to frictional heat and the generation of cutting debris can be suppressed. Consequently, deformation of the cut surface of the wafer and adhesion of cutting debris to the cut surface are less likely to occur, and a semiconductor chip with excellent processing quality can be obtained.

[0119] Cutting is performed by blade dicing. This makes it possible to obtain a semiconductor chip 40 in which at least the bump-forming surface 21a and the side surface are covered with a first cured resin film (r1). The semiconductor chip 40 has excellent strength because its bump-forming surface 21a and side surface are covered with a first cured resin film (r1). Furthermore, because the bump-forming surface 21a and side surface are continuously covered with the first cured resin film (r1) without any breaks, the bonding surface (interface) between the bump-forming surface 21a and the first cured resin film (r1) is not exposed on the side surface of the semiconductor chip 40. Of the bonding surface (interface) between the bump-forming surface 21a and the first cured resin film (r1), the exposed portion that is exposed on the side surface of the semiconductor chip 40 is prone to becoming a starting point for film peeling. In the semiconductor chip 40 of the present invention, since such exposed portions do not exist, film peeling from such exposed portions is less likely to occur during the process of manufacturing the semiconductor chip 40 by cutting the wafer 30 for semiconductor chip manufacturing, or after manufacturing. Therefore, a semiconductor chip 40 is obtained in which peeling of the first cured resin film (r1) as a protective film is suppressed.

[0120] Furthermore, in step (S4), when cutting the portion of the first cured resin film (r1) of the semiconductor chip manufacturing wafer 30 with the first cured resin film (r1) that is formed in the groove 23 along the planned division line, it is preferable that the first cured resin film (r1) is transparent. Because the first cured resin film (r1) is transparent, the semiconductor wafer 21 is visible through it, ensuring the visibility of the planned division line. Therefore, it becomes easier to cut along the planned division line.

[0121] [Process (S-BG)] A schematic of the process (S-BG) is shown in Figure 7. In step (S-BG), as shown in (1-a) of Figure 7, first, the back surface 21b of the semiconductor chip manufacturing wafer 30 is ground with the first composite sheet (α1) attached. "BG" in Figure 7 stands for back grind. Next, as shown in (1-b) of Figure 7, the first release sheet (Y1) is peeled off from the first composite sheet (α1). When grinding the back surface 21b of the semiconductor chip manufacturing wafer 30, the amount of grinding should be at least enough to expose the bottom of the groove portion 23 of the semiconductor chip manufacturing wafer 30. However, further grinding may be performed to grind the first curable resin film (X1) or first curable resin film (r1) embedded in the groove portion 23 along with the semiconductor chip manufacturing wafer 30.

[0122] The above step (S-BG) may be performed after step (S2) and before step (S3), after step (S3) and before step (S4), or in step (S4). In particular, from the viewpoint of making it easier to exhibit the effects of the present invention, it is preferable to perform it after step (S3) and before step (S4), or in step (S4).

[0123] [Process (T)] In one embodiment of the semiconductor chip manufacturing method 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 manufacturing wafer described above.

[0124] According to the manufacturing method of the above embodiment, a semiconductor chip 40 can be obtained in which at least the bump-forming surface 21a and the side surface are covered with a 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 carry out the above step (T).

[0125] More specifically, the above process (T) preferably includes the following process (T1) and process (T2) in this order. • Process (T1): A process of attaching a second-curing resin film (X2) to the back surface of a wafer for semiconductor chip fabrication. • Process (T2): A process to cure a second-curing resin film (X2) to form a second-curing resin film (r2). Furthermore, in 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. More specifically, it is preferable that step (T1) is a step of attaching 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 to the back surface of a wafer for semiconductor chip fabrication, with the second curable resin film (X2) as the attachment surface. In this case, the timing of peeling the second release sheet (Y2) from the second composite sheet (α2) may be between process (T1) and process (T2), or it may be after process (T2).

[0126] In this case, when a second composite sheet (α2) is used in step (T1), it is preferable that the release sheet (Y2) of the second composite sheet (α2) supports the second curable resin film (X2) and also functions as a dicing sheet. Furthermore, in process (S4), 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). This allows the second release sheet (Y2) to function as a dicing sheet when dicing to create individual pieces, making the dicing process easier.

[0127] Here, if process (S3) is performed after process (S-BG), process (T1) may be performed before process (S3), and then process (S3) and process (T2) may be performed simultaneously. In other words, the first curable resin film (X1) and the second curable resin film (X2) may be cured together at the same time. This reduces the number of curing treatments.

[0128] [Process (U)] One embodiment of the semiconductor chip manufacturing method 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) adhering to a part of the top of the bump, to expose the top of the bump. Exposure treatments to expose the top of the bump include etching treatments such as wet etching and dry etching. Examples of dry etching processes include plasma etching. Furthermore, exposure processing may be performed to retract the protective film until the tops of the bumps are exposed, if the tops of the bumps are not exposed on the surface of the protective film.

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

[0130] [Semiconductor chips] The semiconductor chip of the present invention has a bump-forming surface with bumps, and both the bump-forming surface and the side surface have a cured resin film formed by curing the curable resin film of the present invention. The semiconductor chip of the present invention is obtained by cutting a cured resin film embedded in a groove formed in a semiconductor chip manufacturing wafer along a planned division line to create individual pieces. Since the cured resin film is a cured product of the curable resin film described above, when the cured resin film is cut along the planned division line, deformation due to elongation of the cured resin film caused by frictional heat and the generation of cutting debris can be suppressed. Therefore, the semiconductor chip of the present invention is less prone to deformation and adhesion of cutting debris, and has excellent processing quality. [Examples]

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

[0132] 1. Raw materials for the manufacture of compositions for forming curable resin films. The raw materials used in the production of the composition for forming curable resin films are listed below. (1) Polymer component (A) • (A)-1: Polyvinyl butyral having constituent units represented by the following formulas (i)-1, (i)-2, and (i)-3 (Sekisui Chemical Co., Ltd.'s "Eslec BL-10", weight-average molecular weight 25,000, glass transition temperature 59°C) • (A)-2: Polyarylate (Unitika Ltd.'s "Unifiner® M-2040")

[0133] [ka]

[0134] (In the formula, l1 is approximately 28, m1 is between 1 and 3, and n1 is an integer between 68 and 74.)

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

[0136] (3) Thermosetting agent (B2) • (B2)-1: O-cresol-type novolac resin (DIC Corporation's "Phenolite KA-1160", hydroxyl group equivalent 117 g / eq)

[0137] (4) Curing accelerator (C) (C)-1:2-phenyl-4,5-dihydroxymethylimidazole (Curesol 2PHZ-PW, manufactured by Shikoku Chemicals Co., Ltd.)

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

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

[0140] 2. Examples 1-5 and Comparative Examples 1 and 2 2-1. Example 1 (1) Production of composition (1) for forming thermosetting resin film Polymer component (A)-2 (100 parts by mass), epoxy resin (B1)-1 (295 parts by mass), epoxy resin (B1)-4 (210 parts by mass), thermosetting 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) in which the total concentration of all components other than the solvent was 60% by mass. Note that all amounts of components other than the solvent shown herein are the amounts of the target product without the solvent.

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

[0142] 2-2. Examples 2-5 and Comparative Examples 1 and 2 A thermosetting resin film with a thickness of 45 μm was formed in the same manner as in Example 1, except that the types and amounts of components of the thermosetting resin film-forming composition (1) were changed during the manufacturing of the composition (1), so that the types and amounts of components of the composition (1) are as shown in Table 1 described later. In addition, a "-" in the "Components" column of Table 1 indicates 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 used for the following evaluation. The results are shown in Table 2.

[0145] 3-1. Calculation of Crosslinking Density The crosslinking density was calculated using the following formula.

[0146]

number

[0147] 3-2. Measurement of fracture elongation (T) and fracture energy (E), and calculation of T × E Five 45 μm thick thermosetting resin films were laminated at 60°C to prepare a laminated film with a thickness of 225 μm. This laminated film was heat-cured at 130°C and 0.5 MPa for 240 minutes, then placed on a dicing tape (Lintec Corporation's "D-676H"), and subsequently ground using a dicing device (DISCO Corporation's "DFD6362") at a rotation speed of 30,000 rpm, a feed rate of 10 mm / second, and a cutting depth of 20 μm to produce test pieces with a width of 3 mm and a length of 100 mm. The above test specimens were placed in a Tensilon with a constant temperature bath (Tensilon universal material tester (RTG-1210, manufactured by Orientec Co., Ltd.), constant temperature bath for the tester (TKC-R3T-GS, manufactured by Orientec Co., Ltd.)) so that the distance between the chucks was 50 mm, and the elongation at break (T) and the energy at break (E) were measured under conditions of a temperature of 70°C and a speed of 200 mm / min. From the obtained values ​​of elongation at break (T) and energy at break (E), T × E was calculated.

[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 circular disc with a diameter of 25 mm to produce a test specimen of thermosetting resin film with a thickness of 900 μm. In the viscoelasticity measuring device (Anton Paar's "MCR301"), the location where the test specimen was to be placed was preheated to 80°C. The test specimen of the thermosetting resin film obtained above was then placed on this location, and the test specimen was fixed to the location by pressing a measuring jig against the upper surface of the test specimen. Next, under conditions of a temperature of 90°C and a measurement frequency of 1 Hz, the strain generated in the test specimen was gradually increased in the range of 0.01% to 1000%, and the storage modulus Gc of the test specimen was measured. Then, the X value was calculated from the measured values ​​of Gc1 and Gc300.

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

[0150] (2) Evaluation method One side of a 45 μm thick thermosetting resin film was attached to the surface side (half-cut surface) of a semiconductor chip manufacturing wafer under the following conditions while being pressed. • Lamination device: BG tape laminator (Lintec Corporation "RAD-3510F / 8") • Adhesion pressure: 0.5 MPa • Application time: 43 seconds • Application speed: 7mm / second • Application temperature: 80℃ • Roller application height: -200mm Next, a semiconductor chip fabrication wafer with a thermosetting resin film attached was heated at a temperature of 130°C and a pressure of 0.5 MPa for 4 hours to cure it and form a cured resin film. Then, the semiconductor chip fabrication wafer was cut from the half-cut surface toward the back surface, and the embedding of the cured resin film into the grooves of the half-cut portion was observed using an optical microscope (Keyence Corporation "VHX-100"). In addition, the presence or absence of leakage of the cured resin film from the edges of the wafer was observed visually. The evaluation criteria for implantability were as follows: S: No distortion is observed in the shape of the cured resin film, resulting in excellent embedding properties. A: Although slight distortion is observed in the shape of the hardened resin film near the entrance of the groove, the embedding properties are good. B: The implantability is poor.

[0151] 3-5. Evaluation of processing quality and confirmation of the presence or absence of retained material. Five 45 μm thick thermosetting resin films were laminated at 60°C, and then cut into 5 cm x 5 cm sections to prepare a laminated film with a thickness of 225 μm. This laminated film was heat-cured at 130°C and 0.5 MPa for 240 minutes, and then attached to dicing tape (Lintec Corporation's "D-676H"). Next, using a dicing machine (Disco Corporation's "DFD6362", blade: ZH05-SD1500-N1-50-27HECC, blade width 0.03 mm), the side of the laminated film opposite to the side attached to the dicing tape was ground at a rotation speed of 30,000 rpm, a feed rate of 30 mm / second, and a cutting depth of 20 μm, resulting in individual pieces of resin only, 2 mm x 2 mm square (hereinafter simply referred to as "chips"). The surface of the laminated film with the dicing line formed (the side opposite to the side to which the dicing tape was applied) was observed with a digital microscope (Keyence Corporation "VHX-7000") to check for the presence or absence of accumulated material in the dicing line. The results are shown in Table 2 under "Accumulated Material - Surface Side".

[0152] Next, using a UV irradiation device (Lintec Corporation's "RAD-2000F / 12"), an illuminance of 230 mW / cm² was applied to the back surface (the side with the dicing tape attached) of the laminated film. 2 , light intensity 190mJ / cm 2 After irradiating with ultraviolet light under the specified conditions, the surface of the laminated film (the side opposite to the dicing tape application side) was transferred to a semiconductor processing tape (Lintec Corporation's "D-210"). The chip surrounded by the dicing lines was observed from the back side (dicing tape application side) of the laminated film transferred to the semiconductor processing tape using a digital microscope (Keyence Corporation's "VHX-7000"), and the presence or absence of distortion due to accumulated material on the chip was evaluated according to the following criteria. The percentage of chip distortion was calculated using the following formula. The results are shown in Table 2 under "Accumulated Material - Back Side".

[0153]

number

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

[0155] [Evaluation criteria for the back surface of laminated films] 0: No distortion is observed in the dicing line of the chip. 1: Distortion of 1% to less than 20% was observed in the dicing line of the chip. 2: Distortion of 20% to less than 50% was observed in the dicing line of the chip. 3: More than 50% distortion was observed in the dicing line of the chip.

[0156] Next, using a UV irradiation device (Lintec Corporation's "RAD-2000F / 12"), an illuminance of 230 mW / cm² is applied to the semiconductor processing tape side of the laminated film. 2 , light intensity 190mJ / cm 2 After irradiating with ultraviolet light under the specified conditions, chips surrounded by the dicing line were picked up. The side surface of the chips was observed using a scanning electron microscope (SEM, VE-9700, manufactured by Keyence Corporation) from a direction forming a 45° angle to the top surface of the chip, and the processing quality was evaluated according to the following criteria. The percentage of contamination at the chip corners and the percentage of contamination on the chip sides were calculated using the following formulas.

[0157]

number

[0158] In the above formula, Ta is the thickness of the chip after fragmentation (μm), which is 225 μm in this evaluation. Tb is the average value (μm) of the width of the area where cutting debris or retained material is attached at the corner of the fragmented chip (but perpendicular to the chip surface), measured for four chips.

[0159]

number

[0160] In the above formula, Ta is the thickness of the chip after fragmentation (μm), which is 225 μm in this evaluation. Tc is the average value (μm) of the width of the area where cutting debris or retained material is attached on the side surface of the fragmented chip (but perpendicular to the chip surface), measured for four chips.

[0161] [Evaluation of tip angle and side profile] Evaluation (1): The sides of the chip were observed to check for any protrusions caused by the attachment of cutting debris or retained material.

[0162] Evaluation (2): Contamination of tip corners 0: No protrusions due to cutting debris or accumulated material are observed at the corners of the chip. 1: A protrusion is observed on the corner of the chip due to cutting debris or accumulated material, and this protrusion contaminates the corner of the chip by 1% to less than 20%. 2: Protrusions due to cutting debris or accumulated material are observed at the corners of the chips, and these protrusions contaminate 20% to less than 50% of the corners of the chips. 3: A protrusion is observed on the corner of the chip due to cutting debris or accumulated material, and this protrusion contaminates more than 50% of the corner of the chip.

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

[0164] [Table 2]

[0165] Examples 1 to 5 demonstrate that by using a curable resin film with a fracture elongation of 85% or less at 70°C after curing for the formation of a protective film on semiconductor chips, it is possible to obtain semiconductor chips with excellent processing quality, characterized by less deformation of the cut surface and less adhesion of cutting debris and retained substances. [Explanation of symbols]

[0166] 10,20 Composite Sheet 30 Wafers for semiconductor chip fabrication 40 semiconductor chips 1,11 Release sheet 2.12 Curable resin film 3,13 Base material 4,14 Exfoliation layer 15 Middle Class 21 Semiconductor wafers 21a Bump-forming surface 21b Back side 22 Bump 23 Groove X1 First-curing resin film Y1 First release sheet r1 First cured resin film α1 First Composite Sheet X2 Second-curing resin film Y2 Second release sheet r2 Second cured resin film α2 Second 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 curable resin film has a breaking elongation of 85% or less at 70°C after curing.

2. The curable resin film according to claim 1 , wherein the product of breaking elongation and breaking energy of the curable resin film at 70° C. after curing is 1,000 or less.

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

4. 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.

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

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

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

8. 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 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 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 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

9. 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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