Method for manufacturing semiconductor device

Abstract

Disclosed is a method for manufacturing a semiconductor device. This method for manufacturing a semiconductor device includes: a step for preparing a laminate which includes an integrated dicing / die bonding film that has a base material layer, a tackifier layer, and an adhesive layer in this order, and a plurality of semiconductor chips obtained by individualizing a semiconductor wafer that is provided on the adhesive layer of the integrated dicing / die bonding film; a step for forming a groove in the adhesive layer by irradiating the adhesive layer with a laser through a gap among the plurality of semiconductor chips; and a step for producing semiconductor chips with an adhesive layer piece by individualizing the adhesive layer, in which the groove has been formed, by expanding the base material layer. The thickness of the adhesive layer is 30-50 μm, and the depth of the groove is 45% or less with respect to the thickness of the adhesive layer.

Description

Semiconductor device manufacturing method

[0001] The present disclosure relates to a method for manufacturing a semiconductor device.

[0002] In recent years, semiconductor chips have become thinner as semiconductor packages have become smaller and thinner, with higher capacity and more functionality. Thinning semiconductor chips tends to increase the likelihood of defects during processing, such as breakage of semiconductor wafers, and therefore semiconductor device manufacturing processes are also changing from conventional methods. Known processes for suppressing defects during thinning of semiconductor chips include the dicing-before-grinding (DBG) process. Unlike conventional processes that perform a back-grinding process after a back-grinding process, the DBG process performs a back-grinding process after a dicing process. More specifically, this process involves forming grooves on the circuit-forming surface of a semiconductor wafer along dicing lines by half-cut dicing, and then grinding (back-grinding) the back surface of the semiconductor wafer opposite the circuit-forming surface to a depth at least reaching the grooves, thereby simultaneously thinning and singulating the semiconductor wafer (see, for example, Patent Documents 1 and 2). This process makes it possible to produce thin semiconductor chips while suppressing defects during processing.

[0003] In the DBG process, a film called a dicing / die bonding integrated film is attached to the backside of a semiconductor chip. The dicing / die bonding integrated film has a structure in which a base layer, a pressure-sensitive adhesive layer, and an adhesive layer are laminated in this order, and the adhesive layer is attached to the backside of the semiconductor chip. The adhesive layer is then singulated to obtain a semiconductor chip with adhesive layer pieces, which is composed of the semiconductor chip and the singulated adhesive layer. A known method for singulating the adhesive layer is to use a laser to cut the adhesive layer (see, for example, Patent Documents 3 and 4).

[0004] International Publication No. 2016 / 189986 JP 2011-181951 A JP 2018-190940 A JP 2019-121646 A

[0005] A known method for singulating an adhesive layer involves forming grooves in the adhesive layer using a laser, and then expanding the base layer of a dicing / die-bonding integrated film under cooling conditions to separate the adhesive layer. The inventors of the present invention have investigated this method and found that laser irradiation of the adhesive layer tends to cause debris from the adhesive layer to adhere to the surface, side, etc. of the semiconductor chip. If a large amount of debris from the adhesive layer adheres to the semiconductor chip, a process for removing the debris is required, which may reduce the yield of semiconductor chip production.

[0006] An object of the present disclosure is to provide a method for manufacturing a semiconductor device that can suppress adhesion of debris originating from an adhesive layer to a semiconductor chip.

[0007] The present inventors conducted extensive research to solve the above-mentioned problems and discovered that laser irradiation of the adhesive layer causes resin components of the adhesive layer to creep up on the side surfaces of semiconductor chips. Figure 4 shows SEM (scanning electron microscope) images of the side surfaces of semiconductor chips taken after forming grooves in the adhesive layer and expanding under cooling conditions. Figure 4(a) is an SEM image of Example 1, and Figure 4(b) is an SEM image of Comparative Example 1. In Figure 4, thickness A represents the thickness of the adhesive layer after laser irradiation and expanding under cooling conditions, and thickness B represents the thickness of the divided portions of the adhesive layer divided by expanding. Creeping up of the resin components of the adhesive layer refers to a phenomenon in which the adhesive layer becomes thicker after laser irradiation than before laser irradiation. Resin components that have crept up are likely to scatter, which is thought to be a cause of debris generation. Further research by the present inventors revealed a correlation between the creeping height (creeping amount) of the resin components of the adhesive layer and the depth of the grooves in the adhesive layer formed by the laser. That is, it is presumed that as the groove depth in the adhesive layer formed by the laser increases, the resin component of the adhesive layer creeps up to a greater height (amount of creep), which results in the scattering of debris over a wider area. On the other hand, if the groove depth in the adhesive layer formed by the laser is small, it is predicted that a sufficient kerf width (gap between semiconductor chips) between the semiconductor chips cannot be obtained after expanding. However, the present inventors unexpectedly found that a sufficient kerf width between the semiconductor chips can be obtained even in such a case, and have thus completed the invention of the present disclosure.

[0008] The present disclosure provides a method for manufacturing a semiconductor device according to [1] and [2]. [1] A method for manufacturing a semiconductor device, comprising the steps of: preparing a laminate including a dicing and die bonding integrated film having a base layer, a pressure-sensitive adhesive layer, and an adhesive layer in this order; and a plurality of semiconductor chips formed by singulating a semiconductor wafer, the semiconductor chips being provided on the adhesive layer of the dicing and die bonding integrated film; irradiating the adhesive layer with a laser through gaps between the plurality of semiconductor chips to form grooves in the adhesive layer; and expanding the base layer to singulate the adhesive layer with the grooves formed therein, thereby producing semiconductor chips with adhesive layer pieces, wherein the thickness of the adhesive layer is 30 to 50 μm, and the depth of the grooves is 45% or less of the thickness of the adhesive layer. [2] The method for manufacturing a semiconductor device according to [1], wherein the laminate is a laminate produced by a method including the steps of: forming grooves along dicing lines on the circuit formation surface of the semiconductor wafer; grinding the back surface of the semiconductor wafer opposite to the circuit formation surface on which the grooves have been formed to a depth that reaches at least the grooves, thereby producing the plurality of semiconductor chips; and attaching the adhesive layer of the dicing and die bonding integrated film to the back surfaces of the plurality of semiconductor chips.

[0009] According to the present disclosure, a method for manufacturing a semiconductor device is provided that can suppress adhesion of debris originating from an adhesive layer to a semiconductor chip. Some embodiments of the method for manufacturing a semiconductor device are also excellent in that a sufficient kerf width can be obtained between semiconductor chips after expansion.

[0010] FIG. 1 is a schematic cross-sectional view illustrating one embodiment of a method for manufacturing a semiconductor device, with FIGS. 1(a), 1(b), 1(c), and 1(d) illustrating each step. FIG. 2 is a schematic cross-sectional view illustrating one embodiment of a method for manufacturing a semiconductor device, with FIGS. 2(a), 2(b), 2(c), and 2(d) illustrating each step. FIG. 3 is a schematic cross-sectional view illustrating one embodiment of a method for manufacturing a laminate, with FIGS. 3(a), 3(b), 3(c), 3(d), 3(e), and 3(f) illustrating each step. FIG. 4 is a scanning electron microscope (SEM) image of the side of a semiconductor chip taken after forming a groove in an adhesive layer and expanding under cooling conditions. FIG. 4(a) is an SEM image of Example 1, and FIG. 4(b) is an SEM image of Comparative Example 1.

[0011] The present embodiment will be described in detail below with reference to the drawings. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components (including steps, etc.) are not essential unless otherwise specified. The same or equivalent parts are given the same reference numerals, and duplicate explanations will be omitted. Furthermore, unless otherwise specified, positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings. The sizes of the components in each figure are conceptual, and the relative size relationships between the components are not limited to those shown in each figure.

[0012] The same applies to the numerical values ​​and ranges in the present disclosure, and do not limit the present disclosure. In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described in this specification, the upper limit or lower limit of that numerical range may be replaced with a value shown in the examples. Furthermore, the upper limit and lower limit values ​​described individually can be combined in any combination.

[0013] In this specification, the term "layer" includes not only a structure having a shape formed over the entire surface when observed in a plan view, but also a structure having a shape formed on a portion thereof. In this specification, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes as long as the intended effect of the process is achieved.

[0014] In this specification, the term "(meth)acrylate" refers to at least one of an acrylate and its corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylic acid."

[0015] "A or B" means that either A or B is contained, or both are contained. Furthermore, unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. When a plurality of substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified.

[0016] [Method for manufacturing a semiconductor device] One embodiment of the method for manufacturing a semiconductor device includes the steps of: preparing a laminate including a dicing / die-bonding integrated film (hereinafter sometimes referred to as an "integrated film") having a base layer, a pressure-sensitive adhesive layer, and an adhesive layer in this order; and a plurality of semiconductor chips formed by dividing a semiconductor wafer and disposed on the adhesive layer of the integrated film (step (A)); irradiating the adhesive layer with a laser through the gaps between the plurality of semiconductor chips to form grooves in the adhesive layer (step (B)); and expanding the base layer to divide the adhesive layer with the grooves to produce semiconductor chips with adhesive layer pieces (step (C)). Figures 1 and 2 are schematic cross-sectional views illustrating one embodiment of the method for manufacturing a semiconductor device.

[0017] <Step (A)> In this step, a laminate 10 is prepared, which includes an integrated film 9 having a base layer 1, a pressure-sensitive adhesive layer 3, and an adhesive layer 5 in this order, and a plurality of semiconductor chips SC formed by dicing a semiconductor wafer and provided on the adhesive layer 5 of the integrated film 9 (see FIG. 1( a)). In the laminate 10, a dicing ring DR for fixing the semiconductor chips SC may be attached to the surface of the pressure-sensitive adhesive layer 3 opposite to the base layer 1. A laminate film having a base layer and an adhesive layer provided on the base layer is called a dicing film.

[0018] (Substrate Layer) A known polymer sheet or film can be used for the substrate layer 1. Specific examples of the substrate layer 1 include polyolefins such as crystalline polypropylene, amorphous polypropylene, high-density polyethylene, medium-density polyethylene, low-density polyethylene, very low-density polyethylene, low-density linear polyethylene, polybutene, and polymethylpentene, ethylene-vinyl acetate copolymers, ionomer resins, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester (random or alternating) copolymers, ethylene-butene copolymers, ethylene-hexene copolymers, polyurethanes, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polycarbonates, polyimides, polyether ether ketones, polyetherimides, polyamides, wholly aromatic polyamides, polyphenylsulfide, aramid (paper), glass, glass cloth, fluororesins, polyvinyl chloride, polyvinylidene chloride, cellulose-based resins, silicone resins, mixtures of these with a plasticizer, and cured products crosslinked by electron beam irradiation.

[0019] The substrate layer 1 may have a surface primarily composed of at least one resin selected from the group consisting of polyethylene, polypropylene, polyethylene-polypropylene random copolymer, and polyethylene-polypropylene block copolymer, and this surface may be in contact with the pressure-sensitive adhesive layer 3. These resins can be good substrates in terms of properties such as Young's modulus, stress relaxation, and melting point, as well as cost and recycling of waste materials after use. The substrate layer 1 may be a single layer, or may have a multilayer structure in which layers made of different materials are laminated, as necessary. In order to control adhesion to the pressure-sensitive adhesive layer 3, the surface of the substrate layer 1 may be subjected to a surface roughening treatment such as a matte treatment or a corona treatment.

[0020] The thickness of the substrate layer 1 may be, for example, 10 to 200 μm or 20 to 170 μm.

[0021] (Adhesive Layer) The adhesive layer 3 may contain, for example, an ultraviolet-curable adhesive or a non-ultraviolet-curable adhesive, or may contain an ultraviolet-curable adhesive. In one embodiment, the ultraviolet-curable adhesive may contain a (meth)acrylic resin having a chain-polymerizable functional group (hereinafter, sometimes referred to as "(meth)acrylic resin (A)") and a photopolymerization initiator. At least a portion of the (meth)acrylic resin (A) may be crosslinked with a crosslinking agent. In one embodiment, the adhesive layer 3 may be made of an ultraviolet-curable adhesive. In one embodiment, the adhesive layer 3 may be made of a non-ultraviolet-curable adhesive.

[0022] The (meth)acrylic resin (A) has a chain-polymerizable functional group (hereinafter, sometimes referred to as "functional group (A)"). The functional group (A) may be at least one selected from an acryloyl group and a methacryloyl group.

[0023] The content of the functional group (A) in the (meth)acrylic resin (A) may be, for example, 0.1 to 1.2 mmol / g, 0.3 to 1.0 mmol / g, or 0.5 to 0.8 mmol / g.

[0024] The (meth)acrylic resin (A) can be obtained by reacting a (meth)acrylic resin (hereinafter sometimes referred to as "(meth)acrylic resin (B)") having at least one functional group (hereinafter sometimes referred to as "functional group (B)") selected from a hydroxyl group, a glycidyl group (epoxy group), an amino group, etc., with a compound for introducing the functional group (A) described below (hereinafter sometimes referred to as "functional group (A)-introducing compound"). The (meth)acrylic resin (A) can also be considered a reaction product of the (meth)acrylic resin (B) and the functional group (A)-introducing compound.

[0025] The (meth)acrylic resin (B) can be obtained by synthesis using a known method. Examples of synthesis methods include solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, precipitation polymerization, gas phase polymerization, plasma polymerization, and supercritical polymerization. The types of polymerization reactions include radical polymerization, cationic polymerization, anionic polymerization, living radical polymerization, living cationic polymerization, living anionic polymerization, coordination polymerization, and immortal polymerization, as well as techniques such as ATRP (atom transfer radical polymerization) and RAFT (reversible addition-fragmentation chain transfer polymerization). Among these, synthesis by radical polymerization using a solution polymerization method has advantages such as good economy, high reactivity, and ease of polymerization control, as well as the ability to use the resin solution obtained by polymerization as is for blending.

[0026] Here, the synthesis method of the (meth)acrylic resin (B) will be described in detail, taking as an example a method for obtaining the (meth)acrylic resin (B) by radical polymerization using a solution polymerization method.

[0027] The monomer used in synthesizing the (meth)acrylic resin (B) is not particularly limited as long as it has one (meth)acryloyl group in one molecule. Specific examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, butoxyethyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octylheptyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate. aliphatic (meth)acrylates such as methyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, and mono(2-(meth)acryloyloxyethyl)succinate; alicyclic (meth)acrylates such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, mono(2-(meth)acryloyloxyethyl)tetrahydrophthalate, and mono(2-(meth)acryloyloxyethyl)hexahydrophthalate;Benzyl (meth)acrylate, phenyl (meth)acrylate, o-biphenyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, phenoxyethyl (meth)acrylate, p-cumylphenoxyethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 1-naphthoxyethyl (meth)acrylate, 2-naphthoxyethyl (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, nonylphenoxy aromatic (meth)acrylates such as phenoxy polyethylene glycol (meth)acrylate, phenoxy polypropylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-(o-phenylphenoxy)propyl (meth)acrylate, 2-hydroxy-3-(1-naphthoxy)propyl (meth)acrylate, and 2-hydroxy-3-(2-naphthoxy)propyl (meth)acrylate; 2-tetrahydrofurfuryl (meth)acrylate heterocyclic (meth)acrylates such as acrylate, N-(meth)acryloyloxyethylhexahydrophthalimide, 2-(meth)acryloyloxyethyl-N-carbazole, caprolactone-modified products thereof, ω-carboxy-polycaprolactone mono(meth)acrylate, glycidyl (meth)acrylate, α-ethylglycidyl (meth)acrylate, α-propylglycidyl (meth)acrylate, α-butylglycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, 2-ethyl ... compounds having an ethylenically unsaturated group and an epoxy group, such as butylglycidyl (meth)acrylate, 2-propylglycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 3,4-epoxyheptyl (meth)acrylate, α-ethyl-6,7-epoxyheptyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether;Ethylenically unsaturated groups and oxetanyl such as (2-ethyl-2-oxetanyl)methyl (meth)acrylate, (2-methyl-2-oxetanyl)methyl (meth)acrylate, 2-(2-ethyl-2-oxetanyl)ethyl (meth)acrylate, 2-(2-methyl-2-oxetanyl)ethyl (meth)acrylate, 3-(2-ethyl-2-oxetanyl)propyl (meth)acrylate, and 3-(2-methyl-2-oxetanyl)propyl (meth)acrylate compounds having an ethylenically unsaturated group and an isocyanate group, such as 2-(meth)acryloxyethyl isocyanate; and compounds having an ethylenically unsaturated group and a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. The desired (meth)acrylic resin (B) can be synthesized by appropriately combining these;

[0028] The (meth)acrylic resin (B) has at least one functional group (B) selected from a hydroxyl group, a glycidyl group (epoxy group), an amino group, etc. as a reaction site with a functional group (A)-introducing compound or a crosslinking agent described below.

[0029] Examples of the monomer for synthesizing the (meth)acrylic resin (B) having a hydroxyl group include compounds having an ethylenically unsaturated group and a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate.

[0030] Examples of the monomer for synthesizing the (meth)acrylic resin (B) having a glycidyl group include compounds having an ethylenically unsaturated group and an epoxy group, such as glycidyl (meth)acrylate, α-ethylglycidyl (meth)acrylate, α-propylglycidyl (meth)acrylate, α-butylglycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, 2-ethylglycidyl (meth)acrylate, 2-propylglycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 3,4-epoxyheptyl (meth)acrylate, α-ethyl-6,7-epoxyheptyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether.

[0031] The (meth)acrylic resin (A) has a functional group (A) such as an acryloyl group, a methacryloyl group, etc. The functional group (A) can be introduced into the (meth)acrylic resin (B) by, for example, reacting the (meth)acrylic resin (B) having at least one functional group (B) selected from a hydroxyl group, a glycidyl group (epoxy group), an amino group, etc. with a functional group (A)-introducing compound. Specific examples of the functional group (A)-introducing compound include 2-methacryloyloxyethyl isocyanate, α,α-dimethyl-4-isopropenylbenzyl isocyanate, allyl isocyanate, 1,1-(bisacryloxymethyl)ethyl isocyanate; acryloyl monoisocyanate compounds obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate or 4-hydroxybutylethyl (meth)acrylate; and acryloyl monoisocyanate compounds obtained by reacting a diisocyanate compound or a polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate. Among these, the functional group (A)-introducing compound may be 2-methacryloxyethyl isocyanate.

[0032] The (meth)acrylic resin (A) may have at least one functional group (B) selected from a hydroxyl group, a glycidyl group (epoxy group), an amino group, etc., derived from the (meth)acrylic resin (B) as a reactive site, and some of the reactive sites may be crosslinked with a crosslinking agent. That is, at least a portion of the (meth)acrylic resin (A) may be crosslinked with a crosslinking agent. The ultraviolet-curable pressure-sensitive adhesive may contain the (meth)acrylic resin (A) that may be crosslinked with a crosslinking agent.

[0033] The crosslinking agent is used, for example, for the purpose of controlling the storage modulus and / or adhesiveness of the pressure-sensitive adhesive layer. The crosslinking agent may be any compound having, in one molecule, two or more functional groups (hereinafter sometimes referred to as "functional groups (C)") that can react with at least one functional group (B) selected from a hydroxyl group, a glycidyl group (epoxy group), an amino group, etc., derived from the (meth)acrylic resin (B) that may remain in the (meth)acrylic resin (A). Examples of bonds formed by the reaction between the (meth)acrylic resin (A) and the crosslinking agent include ester bonds, ether bonds, amide bonds, imide bonds, urethane bonds, and urea bonds.

[0034] The functional group (C) in the crosslinking agent may be an isocyanate group. That is, the crosslinking agent may be, for example, a polyfunctional isocyanate having two or more isocyanate groups in one molecule. When such a polyfunctional isocyanate is used, it easily reacts with the functional group (B) derived from the (meth)acrylic resin (B) that may remain in the (meth)acrylic resin (A), thereby forming a strong crosslinked structure.

[0035] Examples of polyfunctional isocyanates having two or more isocyanate groups in one molecule include isocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, and lysine isocyanate.

[0036] The crosslinking agent may be a reaction product (isocyanate group-containing oligomer) of a polyfunctional isocyanate with a polyhydric alcohol having two or more hydroxy groups in one molecule. Examples of polyhydric alcohols having two or more hydroxy groups in one molecule include ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, 1,4-cyclohexanediol, and 1,3-cyclohexanediol.

[0037] Among these, the crosslinking agent may be a reaction product (isocyanate group-containing oligomer) of a polyfunctional isocyanate having two or more isocyanate groups per molecule with a polyhydric alcohol having three or more hydroxy groups per molecule. By using such an isocyanate group-containing oligomer as a crosslinking agent, the pressure-sensitive adhesive layer 3 forms a dense crosslinked structure, which tends to prevent the pressure-sensitive adhesive from adhering to the adhesive layer 5 during the pick-up process.

[0038] The content of the crosslinking agent when reacting the (meth)acrylic resin (A) with the crosslinking agent can be appropriately set depending on the cohesive strength, elongation at break, adhesion to the adhesive layer, etc. required for the pressure-sensitive adhesive layer 3. The content of the crosslinking agent may be, for example, 0.1 to 10 parts by mass, 0.2 to 7 parts by mass, or 0.3 to 5 parts by mass relative to 100 parts by mass of the total amount of the (meth)acrylic resin (A).

[0039] The (meth)acrylic resin (A) may be a main component of the ultraviolet-curable pressure-sensitive adhesive (or the pressure-sensitive adhesive layer 3). The content of the (meth)acrylic resin (A) may be 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, or 98% by mass or more, based on the total amount of the ultraviolet-curable pressure-sensitive adhesive (or the pressure-sensitive adhesive layer 3).

[0040] The photopolymerization initiator is not particularly limited as long as it generates chain-polymerizable active species upon irradiation with ultraviolet light. Examples of the photopolymerization initiator include a photoradical polymerization initiator. Here, the chain-polymerizable active species refers to a species that initiates a polymerization reaction by reacting with a chain-polymerizable functional group.

[0041] Examples of the photoradical polymerization initiator include benzoin ketals such as 2,2-dimethoxy-1,2-diphenylethan-1-one; α-hydroxyketones such as 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one; 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, and 1,2-methyl-1-[4-(methylthio)phenyl] α-aminoketones such as 1-[4-(phenylthio)phenyl]-1,2-octadione-2-(benzoyl)oxime; oxime esters such as 1-[4-(phenylthio)phenyl]-1,2-octadione-2-(benzoyl)oxime; phosphine oxides such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o- 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer; benzophenone, N,N,N',N'-tetramethyl-4,4'-diaminobenzophenone, N,N,N',N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxyphenyl benzophenone compounds such as 4'-dimethylaminobenzophenone; quinone compounds such as 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, and 2,3-dimethylanthraquinone;Benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoin compounds such as benzoin, methylbenzoin, and ethylbenzoin; benzyl compounds such as benzyl dimethyl ketal; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinylheptane); N-phenylglycine, and coumarin;

[0042] The content of the photopolymerization initiator in the ultraviolet-curable pressure-sensitive adhesive may be, for example, 0.1 to 30 parts by mass, 0.3 to 10 parts by mass, or 0.5 to 5 parts by mass, relative to 100 parts by mass of the total amount of the (meth)acrylic resin (A).

[0043] The pressure-sensitive adhesive layer 3 may contain other components, such as a resin other than a (meth)acrylic resin having a chain-polymerizable functional group (such as an acrylic monomer or oligomer, or a urethane monomer or oligomer), a tackifier (such as a tackifier), an antistatic agent, or a filler (such as an organic filler or an inorganic filler).

[0044] The thickness of the pressure-sensitive adhesive layer 3 may be, for example, 1 μm or more, 2 μm or more, 3 μm or more, or 5 μm or more, and may be 100 μm or less, 50 μm or less, 20 μm or less, or 15 μm or less.

[0045] In the dicing film 7, the pressure-sensitive adhesive layer 3 is formed on the base layer 1. Known methods can be used to form the pressure-sensitive adhesive layer 3. For example, a laminate of the base layer 1 and the pressure-sensitive adhesive layer 3 may be formed by a two-layer extrusion method, or a varnish of an ultraviolet-curable pressure-sensitive adhesive (varnish for forming the pressure-sensitive adhesive layer) may be prepared and applied to the surface of the base layer 1, or the pressure-sensitive adhesive layer 3 may be formed on a release-treated film and then transferred to the base layer 1.

[0046] The varnish of the ultraviolet-curable pressure-sensitive adhesive (varnish for forming the pressure-sensitive adhesive layer) may be an organic solvent that can dissolve the ultraviolet-curable pressure-sensitive adhesive (the (meth)acrylic resin (A), the photopolymerization initiator, the crosslinking agent, etc.) and that volatilizes when heated. Specific examples of organic solvents include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p-cymene; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, and propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. Examples of the alkyl ether include polyhydric alcohol alkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether; polyhydric alcohol alkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate; and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0047] Among these, from the viewpoints of solubility and boiling point, the organic solvent may be at least one selected from the group consisting of toluene, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, and N,N-dimethylacetamide. The solids concentration of the varnish is usually 10 to 60 mass%.

[0048] (Adhesive Layer) The adhesive layer 5 can be formed using a known die bonding film (a film used to bond a semiconductor chip to a support member or to bond semiconductor chips to each other) or an adhesive composition constituting the same. The adhesive composition constituting the adhesive layer 5 may contain, for example, an epoxy resin, an epoxy resin curing agent, and a reactive group-containing (meth)acrylic copolymer. The adhesive composition constituting the adhesive layer 5 may further contain a coupling agent, a curing accelerator, a filler, etc.

[0049] Examples of epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, alicyclic epoxy resins, aliphatic linear epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, bisphenol A novolac epoxy resins, diglycidyl ethers of biphenols, diglycidyl ethers of naphthalenediols, diglycidyl ethers of phenols, diglycidyl ethers of alcohols, and difunctional epoxy resins such as alkyl-substituted, halide, and hydrogenated versions thereof, and novolac epoxy resins. Other commonly known epoxy resins, such as multifunctional epoxy resins and heterocycle-containing epoxy resins, may also be used. Note that components other than the epoxy resin may be contained as impurities to the extent that they do not impair the properties.

[0050] Examples of epoxy resin curing agents include phenolic resins that can be obtained by reacting a phenolic compound with a xylylene compound that is a divalent linking group in the absence or presence of an acid catalyst. Examples of phenolic compounds used in the production of phenolic resins include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, p-ethylphenol, o-n-propylphenol, m-n-propylphenol, p-n-propylphenol, o-isopropylphenol, m-isopropylphenol, p-isopropylphenol, o-n-butylphenol, m-n-butylphenol, p-n-butylphenol, o-isobutylphenol, m-isobutylphenol, p-isobutylphenol, octylphenol, nonylphenol, 2,4-xylenol, Examples of xylylene compounds that can be used include 2,6-xylenol, 3,5-xylenol, 2,4,6-trimethylphenol, resorcinol, catechol, hydroquinone, 4-methoxyphenol, o-phenylphenol, m-phenylphenol, p-phenylphenol, p-cyclohexylphenol, o-allylphenol, p-allylphenol, o-benzylphenol, p-benzylphenol, o-chlorophenol, p-chlorophenol, o-bromophenol, p-bromophenol, o-iodophenol, p-iodophenol, o-fluorophenol, m-fluorophenol, and p-fluorophenol. Examples of xylylene compounds that are divalent linking groups used in the production of phenolic resins include the following xylylene dihalides, xylylene diglycols, and derivatives thereof.That is, specific examples of the xylylene compound include α,α'-dichloro-p-xylene, α,α'-dichloro-m-xylene, α,α'-dichloro-o-xylene, α,α'-dibromo-p-xylene, α,α'-dibromo-m-xylene, α,α'-dibromo-o-xylene, α,α'-diiodo-p-xylene, α,α'-diiodo-m-xylene, and α,α'-diiodo -o-xylene, α,α'-dihydroxy-p-xylene, α,α'-dihydroxy-m-xylene, α,α'-dihydroxy-o-xylene, α,α'-dimethoxy-p-xylene, α,α'-dimethoxy-m-xylene, α,α'-dimethoxy-o-xylene, α,α'-diethoxy-p-xylene, α,α'-diethoxy-m-xylene, α,α'-diethoxy-o- Xylene, α,α'-di-n-propoxy-p-xylene, α,α'-di-n-propoxy-m-xylene, α,α'-di-n-propoxy-o-xylene, α,α'-diisopropoxy-p-xylene, α,α'-diisopropoxy-m-xylene, α,α'-diisopropoxy-o-xylene, α,α'-di-n-butoxy-p-xylene, α,α'-di-n-butoxy Examples of the isobutoxy-m-xylene include α,α'-di-n-butoxy-o-xylene, α,α'-diisobutoxy-p-xylene, α,α'-diisobutoxy-m-xylene, α,α'-diisobutoxy-o-xylene, α,α'-di-tert-butoxy-p-xylene, α,α'-di-tert-butoxy-m-xylene, and α,α'-di-tert-butoxy-o-xylene.

[0051] When reacting a phenolic compound with a xylylene compound, a phenolic resin can be obtained by reacting the compound at 50 to 250°C using an acidic catalyst such as mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and polyphosphoric acid; organic carboxylic acids such as dimethyl sulfate, diethyl sulfate, p-toluenesulfonic acid, methanesulfonic acid, and ethanesulfonic acid; superacids such as trifluoromethanesulfonic acid; strongly acidic ion exchange resins such as alkanesulfonic acid-type ion exchange resins; strongly acidic ion exchange resins such as perfluoroalkanesulfonic acid-type ion exchange resins (trade name: Nafion, manufactured by DuPont; "Nafion" is a registered trademark); natural and synthetic zeolites; and activated clay (acid clay). The reaction time can be appropriately set depending on the raw materials and reaction temperature, and can be, for example, about 1 to 15 hours. The reaction time can be determined by monitoring the reaction composition using gel permeation chromatography (GPC) or the like.

[0052] The reactive group-containing (meth)acrylic copolymer may be, for example, an epoxy group-containing (meth)acrylic copolymer. The epoxy group-containing (meth)acrylic copolymer may be a copolymer obtained by using glycidyl (meth)acrylate as a raw material in an amount of 0.5 to 6% by mass relative to the resulting copolymer. When the glycidyl (meth)acrylate content is 0.5% by mass or more, high adhesive strength is easily obtained, while when the glycidyl (meth)acrylate content is 6% by mass or less, gelation tends to be suppressed. The monomer constituting the remainder of the reactive group-containing (meth)acrylic copolymer may be, for example, an alkyl (meth)acrylate having an alkyl group having 1 to 8 carbon atoms, such as methyl (meth)acrylate, styrene, acrylonitrile, etc. Among these, the monomer constituting the remainder of the reactive group-containing (meth)acrylic copolymer may be ethyl (meth)acrylate and / or butyl (meth)acrylate. The mixing ratio can be adjusted taking into account the Tg of the reactive group-containing (meth)acrylic copolymer. When the Tg is -10°C or higher, the tackiness of the adhesive layer 5 in the B-stage state tends to be prevented from becoming too great, and handling tends to be excellent. The glass transition point (Tg) of the epoxy group-containing (meth)acrylic copolymer may be, for example, 30°C or lower. The polymerization method is not particularly limited, and examples thereof include pearl polymerization and solution polymerization. An example of a commercially available epoxy group-containing (meth)acrylic copolymer is HTR-860P-3 (trade name, manufactured by Nagase ChemteX Corporation).

[0053] From the viewpoint of adhesiveness and heat resistance, the weight-average molecular weight of the epoxy group-containing (meth)acrylic copolymer may be 100,000 or more, or may be 300,000 to 3,000,000, or 500,000 to 2,000,000. If the weight-average molecular weight is 3,000,000 or less, a decrease in the packing between the chip and the substrate supporting it can be suppressed. The weight-average molecular weight is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve with standard polystyrene.

[0054] The coupling agent may be a silane coupling agent, and specific examples of the silane coupling agent include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltrimethoxysilane.

[0055] Examples of the curing accelerator include tertiary amines, imidazoles, quaternary ammonium salts, etc. Specific examples of the curing accelerator include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium trimellitate.

[0056] The filler may be an inorganic filler. Specific examples of the inorganic filler include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, boron nitride, crystalline silica, and amorphous silica.

[0057] The thickness d1 of the adhesive layer 5 is 30 to 50 μm, and may be, for example, 32 μm or more, 35 μm or more, or 37 μm or more, and may be 48 μm or less, 45 μm or less, or 43 μm or less. When the thickness of the adhesive layer 5 is 30 to 50 μm, the effects shown in the present disclosure tend to be easily and satisfactorily obtained.

[0058] The adhesive layer 5 may be an embodiment that does not contain an epoxy resin or an epoxy resin curing agent. For example, when the adhesive layer 5 contains a reactive group-containing (meth)acrylic copolymer, the adhesive layer 5 may contain the reactive group-containing (meth)acrylic copolymer, a curing accelerator, and a filler.

[0059] The adhesive layer 5 may be formed by preparing a varnish of the adhesive composition (varnish for forming the adhesive layer) and applying it to the surface of the pressure-sensitive adhesive layer 3, or by forming the adhesive layer 5 on a release-treated film and then attaching it to the pressure-sensitive adhesive layer 3. The varnish of the adhesive composition (varnish for forming the adhesive layer) may be an organic solvent that can dissolve each component other than the filler and that volatilizes when heated. Specific examples of the organic solvent include the same organic solvents as those used in the varnish of the ultraviolet-curable pressure-sensitive adhesive.

[0060] (Integrated film) The integrated film 9 can be manufactured, for example, by a method including the steps of preparing a dicing film 7 having a base layer 1 and an adhesive layer 3 provided on the base layer 1, and providing an adhesive layer 5 on the adhesive layer 3 of the dicing film 7.

[0061] (Semiconductor Chip) The semiconductor chip SC is obtained by dividing a semiconductor wafer and can be obtained by, for example, a DBG process. The shape of the semiconductor chip SC in a plan view may be, for example, a square or a rectangle. The area of ​​the semiconductor chip SC is 10 to 250 mm ２ 20 to 200 mm ２ Or 30 to 150 mm ２ The length of one side of the semiconductor chip SC may be, for example, 1 mm or more, and may be 2 to 18 mm or 3 to 15 mm.

[0062] The thickness of the semiconductor chip SC (thickness Dsc described below) may be, for example, 10 to 200 μm, or 20 to 100 μm. The thicknesses of the multiple semiconductor chips SC may be the same or different from each other.

[0063] 3 is a schematic cross-sectional view illustrating one embodiment of a method for manufacturing a laminate. The laminate 10 may be a laminate manufactured by a method including, for example, a step (a) of forming grooves along dicing lines on a circuit-forming surface of a semiconductor wafer, a step (b) of grinding the back surface of the semiconductor wafer opposite to the circuit-forming surface on which the grooves have been formed to a depth that reaches at least the grooves to manufacture a plurality of semiconductor chips, and a step (c) of attaching an adhesive layer of an integrated film to the back surfaces of the plurality of semiconductor chips.

[0064] In step (a), grooves w1 are formed along dicing lines on the circuit formation surface s1 of the semiconductor wafer SW (see FIGS. 3(a) and 3(b)).

[0065] Examples of semiconductor wafers SW include single crystal silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide. The semiconductor wafer SW typically has a circuit-forming surface s1 and a back surface s2 opposite to the circuit-forming surface s1.

[0066] The thickness Dsw of the semiconductor wafer SW is usually larger than the thickness Dsc of the semiconductor chip SC. The thickness Dsw of the semiconductor wafer SW may be, for example, 50 to 3000 μm, 100 to 2000 μm, or 200 to 1500 μm.

[0067] The grooves w1 are formed by performing half-cut dicing using a dicing blade 23 along dicing lines of the semiconductor wafer SW (see FIG. 3(b)). Half-cut dicing means cutting the semiconductor wafer SW to a depth dw1 (depth dw1 may be less than the thickness Dsw of the semiconductor wafer SW) so as not to cut the semiconductor wafer SW completely. Half-cut dicing using the dicing blade 23 can be performed using a commercially available dicing saw. The grooves w1 are formed on the circuit formation surface s1 of the semiconductor wafer SW, for example, so as to form a grid pattern in a plan view.

[0068] In step (b), the back surface s2 of the semiconductor wafer SW (semiconductor wafer SWa) on which the grooves w1 are formed, opposite the circuit formation surface s1, is ground to a depth dw1 that reaches at least the grooves w1, in a portion corresponding to the thickness dw2 of the semiconductor wafer SWa on which the grooves are formed, to produce a plurality of semiconductor chips SC (see FIGS. 3(c), 3(d), and 3(e)). In the semiconductor wafer SWa on which the grooves are formed, the sum of the depth dw1 of the grooves w1 and the thickness dw2 of the semiconductor wafer SWa on which the grooves are formed can be equal to or less than the thickness Dsw of the semiconductor wafer SW.

[0069] In step (b), first, a backgrinding tape 25 is attached to the circuit formation surface s1 of the semiconductor wafer SW on which the grooves w1 are formed (see FIG. 3(c)). The backgrinding tape 25 may be any backgrinding tape used in the relevant field, and may be, for example, a backgrinding tape provided with an adhesive layer containing an ultraviolet-curable adhesive.

[0070] Next, the back surface s2 of the semiconductor wafer SW on which the grooves w1 are formed is ground (see FIG. 3(d)). Grinding the back surface of the semiconductor wafer SW on which the grooves w1 are formed can be performed using a general grinder. By grinding the back surface s2 in this manner, multiple semiconductor chips SC having a thickness Dsc can be produced, as shown in FIG. 3(e). The thickness Dsc can be equal to or less than the depth dw1. The semiconductor chip SC typically has a circuit-forming surface s1 and a back surface s3 opposite to the circuit-forming surface s1.

[0071] In step (c), the adhesive layer 5 of the integrated film 9 is attached to the back surfaces s3 of the semiconductor chips SC obtained above (see FIG. 3(f)). In this way, a laminate 50 having, in this order, the base layer 1, the pressure-sensitive adhesive layer 3, the adhesive layer 5, the semiconductor chips SC, and the backgrind tape 25 can be obtained.

[0072] Subsequently, the backgrind tape 25 is peeled off from the laminate 50 to obtain the laminate 10. When the backgrind tape 25 has an adhesive layer containing an ultraviolet-curable adhesive, the adhesive layer of the backgrind tape 25 is irradiated with ultraviolet light to harden the adhesive layer and reduce its adhesive strength, thereby enabling the backgrind tape 25 to be efficiently peeled off from the laminate 50.

[0073] <Step (B)> In this step, a laser 15 is irradiated onto the adhesive layer 5 through the gaps between the plurality of semiconductor chips SC to form grooves w in the adhesive layer 5 (see FIGS. 1(a) and 1(b)).

[0074] The semiconductor chips SC formed by dividing a semiconductor wafer and provided on the adhesive layer 5 of the integrated film 9 usually have gaps between them. By irradiating the adhesive layer 5 with a laser 15 through the gaps, grooves w can be formed along the shape of the semiconductor chips SC in a planar view. Note that when irradiating the adhesive layer 5 with the laser 15, the laser is adjusted so as not to completely divide the adhesive layer 5.

[0075] The laser 15 is irradiated from the semiconductor chip SC side through the gaps between the semiconductor chips SC, as shown in FIG. 1B. The laser 15 can be irradiated using a commercially available laser saw. The frequency of the laser 15 may be, for example, 30 to 250 kHz, 50 to 200 kHz, or 80 to 120 kHz. The output of the laser 15 may be, for example, 0.05 to 2.0 W, 0.1 to 1.0 W, or 0.2 to 0.5 W. The feed speed during irradiation of the laser 15 may be, for example, 20 to 500 mm / s, 50 to 400 mm / s, or 100 to 300 mm / s.

[0076] The depth d2 of the groove w is 45% or less of the thickness d1 of the adhesive layer 5. When the depth d2 of the groove w is 45% or less of the thickness d1 of the adhesive layer 5, creeping up of the resin component of the adhesive layer on the side surface of the semiconductor chip can be suppressed, and as a result, adhesion of debris originating from the adhesive layer to the semiconductor chip can be suppressed. In one embodiment, the depth d2 of the groove w may be 42% or less or 40% or less of the thickness d1 of the adhesive layer 5, and may be 10% or more, 15% or more, 20% or more, 25% or more, 28% or more, or 30% or more of the thickness d1 of the adhesive layer 5. In one embodiment, the depth d2 of the groove w may be 40% or less, 35% or less, 30% or less, or 25% or less of the thickness d1 of the adhesive layer 5, and may be 10% or more, 15% or more, or 20% or more.

[0077] The depth d2 of the groove w can be adjusted by, for example, appropriately adjusting the frequency, output, and feed rate of the laser 15 during irradiation.

[0078] <Step (C)> In this step, the base layer 1 is expanded to separate the adhesive layer 5 having the grooves w formed therein, thereby producing semiconductor chips 13 with adhesive layer pieces (see Figures 1(c) and 1(d)).

[0079] An example of a method for expanding the base layer 1 is to push up the region inside the dicing ring DR of the dicing film 7 (base layer 1) with a ring Ra under cooling conditions (cooling expansion, see FIG. 1(c)). The temperature of the cooling conditions may be, for example, −15 to 0° C. By expanding the base layer 1, the adhesive layer 5 is divided along the grooves w. This division forms, on the pressure-sensitive adhesive layer 3, a semiconductor chip 13 with adhesive layer pieces, which includes the semiconductor chip SC and adhesive layer pieces 5a obtained by dividing the adhesive layer 5.

[0080] After the ring Ra is lowered, the area of ​​the dicing film 7 between the dicing ring DR and the semiconductor chips 13 with adhesive layer pieces may be heated by a heater H (see FIG. 1(d)). The dicing film 7 in the heated area will thermally shrink, making it possible to further widen the kerf width between the semiconductor chips 13 with adhesive layer pieces.

[0081] The method for manufacturing a semiconductor device of this embodiment may further include a step of irradiating the adhesive layer 3 with ultraviolet light to form an adhesive cured layer 11 containing a cured product of the ultraviolet-curable adhesive (step (D)), a step of picking up the semiconductor chip 13 with the adhesive layer piece (step (E)), a step of thermocompressing the picked-up semiconductor chip 13 with the adhesive layer piece and the support member 21 via the adhesive layer piece 5a (step (F)), and a step of thermally curing the adhesive layer piece 5a (step (G)).

[0082] <Step (D)> This step is performed when the pressure-sensitive adhesive layer 3 contains an ultraviolet-curable pressure-sensitive adhesive. When the pressure-sensitive adhesive layer 3 does not contain an ultraviolet-curable pressure-sensitive adhesive, this step may be omitted. In this step, the pressure-sensitive adhesive layer 3 of the laminate 10 is irradiated with ultraviolet light to form a pressure-sensitive adhesive cured product layer 11 containing a cured product of the ultraviolet-curable pressure-sensitive adhesive (see FIGS. 2( a) and 2(b)).

[0083] For example, as shown in Fig. 2(a), ultraviolet light is irradiated from the substrate layer 1 side through the substrate layer 1. The source of ultraviolet light irradiation is not particularly limited, but for example, a metal halide lamp, a high-pressure sodium lamp, a UV-LED lamp, etc. can be used. The illuminance of ultraviolet light on the pressure-sensitive adhesive layer 3 is, for example, 1 to 1000 mW / cm ２ , 10~900mW / cm ２ , or 30 to 800 mW / cm ２ The amount of ultraviolet light irradiated onto the pressure-sensitive adhesive layer 3 may be, for example, 10 to 3000 mJ / cm. ２ , 50-2500mJ / cm ２ , or 100 to 2000 mJ / cm ２ It may be.

[0084] <Step (E)> In this step, if necessary, the individualized semiconductor chips 13 with adhesive layer pieces are pushed up from the base layer 1 side by a needle 17 while being separated from each other, and the pushed-up semiconductor chips 13 with adhesive layer pieces are sucked up by a suction collet 19 and picked up from the adhesive cured layer 11 (or adhesive layer 3) (see FIG. 2(c)).

[0085] <Step (F)> In this step, the picked-up semiconductor chip 13 with adhesive layer piece is bonded to the support member 21 by thermocompression via the adhesive layer piece 5 a. One or more semiconductor chips 13 with adhesive layer piece (semiconductor chip SC) may be bonded to the support member 21.

[0086] The thermocompression bonding conditions for the semiconductor chip 13 with the adhesive layer piece can be adjusted as appropriate depending on the constituent components of the adhesive layer piece 5a. The heating temperature in the thermocompression bonding may be, for example, 80 to 160°C. The load in the thermocompression bonding may be, for example, 5 to 15 N. The heating time in the thermocompression bonding may be, for example, 0.5 to 20 seconds.

[0087] <Step (G)> In this step, the adhesive layer piece 5a is thermally cured. The thermal curing conditions for the adhesive layer piece 5a can be adjusted appropriately depending on the constituent components of the adhesive layer piece 5a. The heating temperature for thermal curing may be, for example, 60 to 200°C, 90 to 190°C, or 120 to 180°C. The heating time for thermal curing may be 30 minutes to 5 hours, 1 to 3 hours, or 2 to 3 hours. The temperature or pressure may be changed stepwise during the thermal curing.

[0088] In this way, a semiconductor device 40 (see Figure 2 (d)) can be manufactured, which comprises (multiple) semiconductor chips SC, a support member 21 on which the semiconductor chips SC are mounted, and a cured product of the adhesive layer piece 5a (cured product of the adhesive layer piece 5ac) that bonds the semiconductor chips SC and the support member 21.

[0089] According to the manufacturing method of the semiconductor device of the present embodiment, it is possible to prevent the resin component of the adhesive layer from creeping up on the side surface of the semiconductor chip, and as a result, it is possible to prevent the adhesion of debris originating from the adhesive layer to the semiconductor chip. Some embodiments of the manufacturing method of the semiconductor device are also excellent in that a sufficient kerf width can be obtained between the semiconductor chips after expansion.

[0090] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to these examples. Unless otherwise specified, all chemicals used were reagents (commercially available products).

[0091] [Synthesis of (meth)acrylic resin] (Production Example 1: Synthesis of (meth)acrylic resin 1a) The following components were placed in a 2000 mL flask equipped with a three-one motor, a stirring blade, and a nitrogen inlet tube: ethyl acetate (solvent): 635 parts by mass, 2-ethylhexyl acrylate: 395 parts by mass, 2-hydroxyethyl acrylate: 100 parts by mass, methacrylic acid: 5 parts by mass, and azobisisobutyronitrile: 0.08 parts by mass.

[0092] The contents were stirred until sufficiently homogenous, and then bubbling was performed for 60 minutes at a flow rate of 500 mL / min to degas the dissolved oxygen in the system. The temperature was raised to 78°C over 1 hour, and polymerization was allowed to continue for 6 hours after the temperature increase. Next, the reaction solution was transferred to a 2000 mL autoclave equipped with a three-one motor, a stirring blade, and a nitrogen inlet tube, and heated at 120°C and 0.28 MPa for 4.5 hours, after which it was cooled to room temperature (25±3°C, the same applies below).

[0093] Next, 490 parts by mass of ethyl acetate was added and stirred to dilute the contents. To this, 0.10 parts by mass of dioctyltin dilaurate was added as a urethanization catalyst, and then 105.3 parts by mass of 2-methacryloyloxyethyl isocyanate (Karenz MOI (trade name) manufactured by Showa Denko K.K.) was added, and the mixture was allowed to react at 70°C for 6 hours, followed by cooling to room temperature. Next, further ethyl acetate was added, and the nonvolatile content of the (meth)acrylic resin solution was adjusted to 35% by mass, thereby obtaining a solution containing the (meth)acrylic resin 1a of Production Example 1.

[0094] (Production Example 2: Preparation of dicing film 2a) A UV-curable adhesive varnish (varnish for forming an adhesive layer) was prepared by mixing the following components (see Table 1). The amount of ethyl acetate (solvent) was adjusted so that the total solid content of the varnish was 25 mass %. (Meth)acrylic resin (A): a solution containing the (meth)acrylic resin 1a of Production Example 1: 100 parts by mass (solid content) Photopolymerization initiator: Omnirad 184 (trade name ("Omnirad" is a registered trademark), 1-hydroxycyclohexyl phenyl ketone, manufactured by IGM RESINS B.V.): 1.0 part by mass Photopolymerization initiator: Omnirad 819 (trade name ("Omnirad" is a registered trademark), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, manufactured by IGM RESINS B.V.): 0.2 part by mass Crosslinking agent: Coronate L (trade name, polyfunctional isocyanate (reaction product of tolylene diisocyanate and trimethylolpropane), manufactured by Nippon Polyurethane Industry Co., Ltd., solid content 75% by mass): 2.0 parts by mass (solid content) Ethyl acetate (solvent)

[0095] A polyethylene terephthalate film (width 450 mm, length 500 mm, thickness 38 μm) with a release treatment applied to one surface was prepared. A UV-curable adhesive varnish was applied to the release-treated surface using an applicator, and then dried at 80°C for 3 minutes. This resulted in a dicing film 2a comprising a polyethylene terephthalate film as a base layer and a 10 μm-thick adhesive layer formed thereon.

[0096] A polyolefin film (width 450 mm, length 500 mm, thickness 90 μm) was prepared, with one side subjected to corona treatment. The corona-treated surface was bonded to the pressure-sensitive adhesive layer of the laminate at room temperature. Next, the pressure-sensitive adhesive layer was transferred to the polyolefin film (cover film) by pressing with a rubber roll. After that, the film was left at room temperature for 3 days to obtain a dicing film 2a with a cover film of Production Example 2.

[0097] (Production Example 3: Production of die bonding film 3a) A varnish for forming an adhesive layer was prepared by mixing the following components: First, cyclohexanone (solvent) was added to a mixture containing the following components, and the mixture was stirred and mixed, and then further kneaded for 90 minutes using a bead mill. Epoxy resin: N-500P-10 (trade name, manufactured by DIC Corporation, o-cresol novolac epoxy resin, epoxy equivalent: 204 g / eq, softening point: 75 to 85°C): 11 parts by mass; Epoxy resin: EXA-830CRP (trade name, manufactured by DIC Corporation, bisphenol F epoxy resin, epoxy equivalent: 160, molecular weight: 1800, softening point: 85°C): 8 parts by mass; Epoxy resin curing agent: MEH-7800M (trade name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Corporation), phenylaralkyl phenol resin, hydroxyl group equivalent: 174 g / eq, softening point: 80°C): 15 parts by mass; Coupling agent: NUC A-189 (trade name, manufactured by Momentive Performance Materials Japan, LLC, silane coupling agent, γ-mercaptopropyltrimethoxysilane): 0.1 part by mass; Coupling agent: NUC A-1160 (trade name, manufactured by Momentive Performance Materials Japan, LLC, silane coupling agent, γ-ureidopropyltriethoxysilane): 0.2 parts by mass Filler: SC2050-HLG (trade name, manufactured by Admatechs Co., Ltd., silica filler, average particle size: 0.50 μm): 40 parts by mass

[0098] The following components were further added to the mixture obtained as described above, and then the mixture was subjected to stirring, mixing, and vacuum deaeration to obtain a varnish for forming an adhesive layer. Reactive group-containing (meth)acrylic copolymer: SG-P3 (trade name, manufactured by Nagase ChemteX Corporation, acrylic rubber, weight average molecular weight: 800,000, Tg: 12°C): 24.6 parts by mass; Curing accelerator: Curesol 2PZ-CN (trade name ("Curesol" is a registered trademark), manufactured by Shikoku Chemicals Corporation, 1-cyanoethyl-2-phenylimidazole): 0.1 parts by mass.

[0099] A polyethylene terephthalate film (35 μm thick) with a release treatment applied to one surface was prepared. A varnish for forming an adhesive layer was applied to the release-treated surface using an applicator, and then heated and dried at 140° C. for 5 minutes. This resulted in a die-bonding film 3a including a polyethylene terephthalate film (carrier film) and a 40 μm thick adhesive layer (in a B-stage state) formed thereon.

[0100] (Production Example 4: Preparation of Integrated Film 4a) The die bonding film 3a was cut together with the carrier film into a circle with a diameter of 312 mm. A dicing film 2a from which the polyethylene terephthalate film had been peeled was attached to the cut die bonding film 3a at room temperature, and then left at room temperature for one day. Thereafter, the dicing film 2a was cut into a circle with a diameter of 370 mm. In this way, an integrated film 4a of Production Example 4 was obtained.

[0101] [Fabrication of Laminate] A semiconductor wafer (silicon wafer) with a thickness of 775 μm was prepared, and a fully automatic dicer (DFD6361, manufactured by Disco Corporation) was used to half-cut the circuit-forming surface (front surface) of the semiconductor wafer to form a groove with a depth of 60 μm. The dicing blade used was a Disco Corporation ZH05-SD4000-N1-70-DD dicing blade, and the rotation speed and cutting speed were 40,000 rpm and 30 mm / s, respectively. The size of the semiconductor chip was 4 mm × 12 mm.

[0102] Next, a backgrinding tape laminator (RAD-3520F / 12, manufactured by Lintec Corporation) was used to attach a backgrinding tape to the circuit formation surface (front surface) of the semiconductor wafer, and then a grinder (DGP8761, manufactured by Disco Corporation) was used to grind the semiconductor wafer from the back surface side so that the thickness of the semiconductor chips finally obtained would be 90 μm, and the semiconductor wafer was divided into a plurality of semiconductor chips.

[0103] Next, to reduce the adhesive strength between the backgrinding tape and the semiconductor chip, ultraviolet light was irradiated onto the backgrinding tape using a wafer mounter (DFM2800, manufactured by Disco Corporation). Then, using the same wafer mounter (DFM2800, manufactured by Disco Corporation), an integrated film 4a was attached to the backside of the diced semiconductor wafer (the backside of the semiconductor chip) at a temperature of 70°C, a tension level of 5, and an attachment speed of 10 mm / sec. At this time, a ring frame was attached to the outer peripheral region of the dicing tape. The backgrinding tape was then peeled off to produce multiple laminates each including an integrated film having a base layer, a pressure-sensitive adhesive layer, and an adhesive layer in this order, and multiple semiconductor chips formed by dicing the semiconductor wafer and disposed on the adhesive layer of the integrated film.

[0104] Example 1 Preparation and Evaluation of Laminate for Evaluation (Preparation of Laminate for Evaluation) A laser was irradiated through the gap between the semiconductor chips using a laser saw (DFL7160, manufactured by Disco Corporation) on the prepared laminate to form grooves in the adhesive layer. The laser irradiation conditions were a frequency of 100 kHz, an output of 0.7 W, a feed rate of 200 mm / s, a defocus amount of −0.09 mm, and a laser width of 3.7 μm. The laser width was determined by measuring it in advance using the following procedure. First, an integrated film 4a was prepared as a sample, and the adhesive layer was irradiated with a laser under the above laser irradiation conditions. Next, the grooves provided on the surface of the adhesive layer were observed, and the width of the grooves was measured to determine the laser width.

[0105] Next, the base material layer was expanded by cooling and expanding under the following conditions using a die separator (DDS2300, manufactured by Disco Corporation), thereby dividing the adhesive layer. The dicing film was then shrunk by heating under the following conditions. (Cooling and expanding conditions) Cooling temperature: -2°C Cooling time: 100 seconds Push-up amount: 14 mm Push-up speed: 8 mm / sec Holding time after push-up: 3 seconds (Heating conditions) Heater temperature: 250°C Heater rotation speed: 5° / sec Push-up amount: 9 mm Push-up speed: 1 mm / sec Tape cooling waiting time: 0 seconds

[0106] Next, in the same manner as above, a die separator was used to apply an illuminance of 80 mW / cm to the pressure-sensitive adhesive layer from the base layer side to the pressure-sensitive adhesive layer in order to reduce the adhesive strength between the pressure-sensitive adhesive layer and the adhesive layer. ２ and an irradiation dose of 130 mJ / cm ２ In this way, a plurality of evaluation laminates of Example 1 having, in this order, a base layer, a cured adhesive layer, and a plurality of semiconductor chips with adhesive layer pieces attached thereto were obtained.

[0107] (Evaluation of Evaluation Laminate) (1) Measurement of the Depth of the Groove Caused by Laser Irradiation and the Height of the Resin Component of the Adhesive Layer The depth of the groove caused by laser irradiation and the height of the resin component of the adhesive layer were measured for the evaluation laminate of Example 1. Using tweezers, the semiconductor chip with the adhesive layer piece was peeled off from the evaluation laminate of Example 1, and the side of the semiconductor chip with the adhesive layer piece was observed using an SEM (scanning electron microscope, SU1510, manufactured by Hitachi High-Technologies Corporation). The depth of the groove caused by laser irradiation and the height of the resin component of the adhesive layer were measured. Figure 4 shows SEM (scanning electron microscope) images of the side of a semiconductor chip taken after forming a groove in the adhesive layer and expanding under cooling conditions. Figure 4(a) is an SEM image of Example 1, and Figure 4(b) is an SEM image of Comparative Example 1. In Figure 4, thickness A represents the thickness of the adhesive layer after laser irradiation and expansion under cooling conditions, and thickness B represents the thickness of the divided portion of the adhesive layer divided by expanding. The thickness of the adhesive layer before laser irradiation (40 μm) minus thickness B corresponds to the depth of the groove formed in the adhesive layer by laser irradiation. The thickness of the adhesive layer before laser irradiation (40 μm) minus thickness A corresponds to the creeping height of the resin component of the adhesive layer. The results are shown in Table 1.

[0108] (2) Measurement of debris scattering distance For the evaluation laminate of Example 1, debris on the surface of the semiconductor chip of the semiconductor chip with adhesive layer piece was observed using a 3D measuring laser microscope (OLS4100, manufactured by Olympus Corporation). The magnification was set to 20x, and the debris scattering distance from the chip edge was measured from the obtained image using the length measurement function. Observations were performed with N=8, and the average value was taken as the debris scattering distance from the chip edge. The longer the debris scattering distance, the more debris was generated from the adhesive layer and the greater the amount of debris adhered. The results are shown in Table 1.

[0109] (3) Evaluation of Kerf Width In the evaluation laminate of Example 1, the width of the gaps (kerf width) between the lattice-shaped semiconductor chips was measured by microscopic observation. The width of the gaps along the MD direction (machine direction, the direction parallel to the longitudinal direction (flow direction) of the raw roll from which the base film is obtained) or TD direction (transverse direction, the direction perpendicular to the MD direction) around the semiconductor chip was measured at two locations near each of the four positions that divide the outer periphery of the semiconductor wafer (silicon wafer) into four equal parts, and at one location in the center of the semiconductor wafer. The average value of the gap widths along the MD direction or TD direction measured at a total of nine locations was calculated, and this was used as the kerf width in the MD direction or TD direction. A large kerf width (e.g., 45 μm or more) tends to suppress the occurrence of problems when picking up semiconductor chips with adhesive layer pieces. The results are shown in Table 1.

[0110] (4) Evaluation of Dividing Width In the evaluation laminate of Example 1, the dividing width of the adhesive layer in the gaps between the lattice-shaped semiconductor chips was measured by microscopic observation. The dividing width of the adhesive layer was determined by measuring the width of the transmitted portion when light was applied from the base layer side of the evaluation laminate. More specifically, the width of the transmitted portion along the MD or TD direction around the semiconductor chip was measured at two locations near each of four positions that divide the outer periphery of the semiconductor wafer (silicon wafer) into four equal parts, and at one location in the center of the semiconductor wafer. The average value of the width of the transmitted portion along the MD or TD direction measured at a total of nine locations was calculated, and this was used as the dividing width in the MD or TD direction. A large dividing width (e.g., 10 μm or more) tends to suppress the occurrence of problems when picking up semiconductor chips with adhesive layer pieces. The results are shown in Table 1.

[0111] Examples 2 and 3 and Comparative Examples 1 and 2 Preparation and Evaluation of Evaluation Laminates Laminates for evaluation in Examples 2 and 3 and Comparative Examples 1 and 2 were prepared in the same manner as in Example 1, except that grooves were formed in the adhesive layer under the laser irradiation conditions in Table 1. Evaluations were carried out using the prepared evaluation laminates in the same manner as in Example 1. The results are shown in Table 1.

[0112]

[0113] As shown in Table 1, when the adhesive layer thickness was 30 to 50 μm, the evaluation laminates of Examples 1 to 3, in which the groove depth was adjusted to 45% or less of the adhesive layer thickness, were found to have a shorter scattering distance of debris on the surface of the semiconductor chip and a smaller amount of debris than the evaluation laminates of Comparative Examples 1 and 2, in which the groove depth was adjusted to more than 45% of the adhesive layer thickness. These findings confirmed that the manufacturing method for a semiconductor device according to the present disclosure is capable of suppressing the adhesion of adhesive layer-derived debris to a semiconductor chip.

[0114] 1...base material layer, 3...adhesive layer, 5...adhesive layer, 5a...adhesive layer piece, 5ac...cured product of adhesive layer piece, 7...dicing film, 9...integrated film, 10, 50...laminated body, 11...cured adhesive layer, 13...semiconductor chip with adhesive layer piece, 15...laser, 17...needle, 19...suction collet, 21...support member, 23...dicing blade, 25...backgrinding tape, 40...semiconductor device, SC...semiconductor chip, SW...semiconductor wafer, SWa...semiconductor wafer with groove formed therein, DR...dicing ring, s1...circuit forming surface, s2, s3...back surface, w, w1...groove.

Claims

1. A method for manufacturing a semiconductor device, comprising the steps of: preparing a laminate comprising a dicing / die bonding integrated film having a base layer, a pressure-sensitive adhesive layer, and an adhesive layer in this order; and a plurality of semiconductor chips formed by dicing a semiconductor wafer, the plurality of semiconductor chips being provided on the adhesive layer of the dicing / die bonding integrated film; irradiating the adhesive layer with a laser through the gaps between the plurality of semiconductor chips to form grooves in the adhesive layer; and expanding the base layer to diced the adhesive layer with the grooves formed therein, thereby producing semiconductor chips with adhesive layer pieces; wherein the thickness of the adhesive layer is 30 to 50 μm, and the depth of the grooves is 45% or less of the thickness of the adhesive layer.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the laminate is a laminate produced by a method including the steps of: forming grooves along dicing lines on the circuit formation surface of the semiconductor wafer; grinding the back surface of the semiconductor wafer opposite the circuit formation surface on which the grooves are formed to a depth that reaches at least the grooves to produce the multiple semiconductor chips; and attaching the adhesive layer of the dicing and die bonding integrated film to the back surfaces of the multiple semiconductor chips.