Evaluation method of photocurable pressure-sensitive adhesive, dicing die bonding integrated film and method for manufacturing the same, and method for manufacturing semiconductor device

Abstract

The present invention discloses a method for evaluating a photocurable pressure-sensitive adhesive for a dicing die-bonding integrated film. In addition, a dicing die-bonding integrated film based on the method for evaluating the photocurable pressure-sensitive adhesive and a method for manufacturing the same are disclosed. A method for manufacturing a semiconductor device using the dicing die-bonding integrated film is also disclosed.

Description

Technical Field

[0001] The present invention relates to an evaluation method of a photocurable pressure-sensitive adhesive, a dicing / die-bonding integrated film and a manufacturing method thereof, and a manufacturing method of a semiconductor device. Background Art

[0002] In the manufacture of semiconductor chips, there are usually a dicing process for singulating a semiconductor wafer into individual semiconductor chips and a die bonding process for bonding the singulated semiconductor chips to a lead frame, a package substrate, etc. In the manufacture of such semiconductor chips, a dicing-die bonding integrated film is mainly used, which is obtained by combining a dicing film and a die bonding film, wherein the dicing film has a photocurable pressure-sensitive adhesive layer formed of a photocurable pressure-sensitive adhesive for fixing the semiconductor wafer in the dicing process, and the die bonding film has an adhesive layer for bonding the semiconductor chip to the lead frame, a package substrate, etc.

[0003] In recent years, as an example of a method for manufacturing semiconductor chips by singulating thin semiconductor wafers, a so-called stealth cutting method has been proposed, which involves not completely cutting the semiconductor wafer but irradiating the inside of the semiconductor wafer on a predetermined cutting line with laser light to form a modified layer, thereby expanding the cutting film and cutting the semiconductor wafer (for example, Patent Document 1). From the viewpoint of preventing the semiconductor chips singulated by stealth cutting from being damaged in the subsequent picking process, it is required to peel off the die bonding film and the cutting film with a smaller force. However, if peeling is performed with a small force, there is a tendency that the peeling time will become longer and the productivity will decrease. Therefore, for the cutting die bonding integrated film used in the manufacture of thin semiconductor chips, it is required to be able to improve the success rate of picking up and shorten the peeling time of picking up, so the selection of the photocurable pressure-sensitive adhesive constituting the photocurable pressure-sensitive adhesive layer becomes important.

[0004] Previous technical literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2003-338467

[0007] Patent Document 2: Japanese Patent Application Publication No. 2004-017639

[0008] Patent Document 3: Japanese Patent Application Publication No. 2006-089521

[0009] Patent Document 4: Japanese Patent Application Publication No. 2006-266798

[0010] Patent Document 5: Japanese Patent Application Publication No. 2014-055250

[0011] Patent Document 6: Japanese Patent Application Publication No. 2014-181258

[0012] Patent Document 7: Japanese Patent Application Publication No. 2015-028146 Summary of the invention

[0013] Technical issues to be solved by the invention

[0014] However, in the manufacture of semiconductor chips, it is difficult to predict in advance whether a photocurable pressure-sensitive adhesive to be used as a photocurable pressure-sensitive adhesive layer of a dicing die bonding integrated film has excellent pickup properties, and in many cases, this is not known until actual use.

[0015] Means for solving technical problems

[0016] The present invention has been made in view of such circumstances, and a main object of the present invention is to provide a novel evaluation method of a photocurable pressure-sensitive adhesive used for a dicing die bonding integrated film.

[0017] As factors affecting the peelability of the adherend and the pressure-sensitive adhesive, the adhesive force of the pressure-sensitive adhesive (the overall characteristics of the pressure-sensitive adhesive), the interaction at the interface between the adherend and the pressure-sensitive adhesive (the surface characteristics of the pressure-sensitive adhesive), etc. can be cited. It is generally known that the overall characteristics contribute more to the peelability than the surface characteristics, and there is a tendency to control the peelability by adjusting the overall characteristics. However, it is believed that the influence of the surface characteristics cannot be ignored with respect to the pickup of thin semiconductor chips. For example, the deformation form of the pressure-sensitive adhesive between the adherend and the pressure-sensitive adhesive, for example, when peeling the adherend and the pressure-sensitive adhesive, the wire drawing of the pressure-sensitive adhesive between the adherend and the pressure-sensitive adhesive without breaking depending on the situation, and sometimes the wire drawing that is greatly deformed like a thread or a wall, also has a great influence on the peelability. In the previous industrial field, the occurrence of the wire drawing phenomenon was considered to be an undesirable phenomenon of the pressure-sensitive adhesive, and the peelability was improved by reducing or suppressing the occurrence of wire drawing (for example, refer to the above-mentioned patent documents 2 to 7, etc.). Under such circumstances, the inventors conducted in-depth research and found that when peeling the adherend and the pressure-sensitive adhesive, when a specific wire drawing phenomenon is observed, the peeling progresses faster and the peeling speed increases due to the propagation of the wire drawing breaking impact, compared with the case where no wire drawing phenomenon is observed, thereby completing the present invention.

[0018] One aspect of the present invention provides a method for evaluating a photocurable pressure-sensitive adhesive for a die-cutting integrated film. The method for evaluating a photocurable pressure-sensitive adhesive comprises: a first step of preparing a die-cutting integrated film having a substrate layer, a photocurable pressure-sensitive adhesive layer formed by a photocurable pressure-sensitive adhesive, and an adhesive layer stacked in sequence, irradiating the photocurable pressure-sensitive adhesive layer with ultraviolet light under the following irradiation conditions to form a cured product of the photocurable pressure-sensitive adhesive layer, and measuring the peeling force when the cured product of the adhesive layer and the photocurable pressure-sensitive adhesive layer are peeled off under the following peeling conditions; a second step of preparing a die-cutting integrated film having a substrate layer, a photocurable pressure-sensitive adhesive layer formed by a photocurable pressure-sensitive adhesive, and an adhesive layer stacked in sequence. The method comprises the following steps: combining an integral molded film, treating a photocurable pressure-sensitive adhesive layer under the following heating and cooling conditions, irradiating the photocurable pressure-sensitive adhesive layer with ultraviolet rays under the following irradiation conditions to form a cured product of the photocurable pressure-sensitive adhesive layer, peeling off the adhesive layer and the cured product of the photocurable pressure-sensitive adhesive layer under the following peeling conditions, observing the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off using a scanning probe microscope, and measuring the number and width of wire drawing marks on the surface; and a third step of judging the quality of the photocurable pressure-sensitive adhesive based on the peeling force and the number and width of wire drawing marks.

[0019] (irradiation conditions)

[0020] Irradiation intensity: 70mW / cm 2

[0021] Total light intensity: 150mJ / cm 2

[0022] (Peeling conditions)

[0023] Temperature: 25±5℃

[0024] Humidity: 55±10%

[0025] Peeling angle: 30°

[0026] Peeling speed: 600mm / min

[0027] (Heating and cooling conditions)

[0028] Heat treatment: 65°C, 15 minutes

[0029] Cooling treatment: Leave in air for 30 minutes until the temperature reaches 25±5℃

[0030] Such a method of evaluating a photocurable pressure-sensitive adhesive is useful for predicting in advance whether a photocurable pressure-sensitive adhesive to be used as a photocurable pressure-sensitive adhesive layer of a dicing die bonding integrated film has excellent pickup properties.

[0031] The third step may be a step of judging the quality of the photocurable pressure-sensitive adhesive based on whether the peeling force and the number and width of stringing marks satisfy the following conditions (a) and (b).

[0032] Condition (a): Peel force is 0.70 N / 25 mm or less.

[0033] Condition (b): After the adhesive layer is peeled off, a 25 μm×25 μm region having 15 or more wire drawing marks exists on the surface of the cured product of the photocurable pressure-sensitive adhesive layer, and the median of the wire drawing mark width in the region is 120 to 200 nm.

[0034] The photocurable pressure-sensitive adhesive may contain a (meth)acrylic copolymer having a reactive functional group, a photopolymerization initiator, and a crosslinking agent having two or more functional groups capable of reacting with the reactive functional group. The (meth)acrylic copolymer may further contain a (meth)acrylic acid monomer unit.

[0035] The adhesive layer may contain an epoxy resin, an epoxy resin curing agent, and a (meth)acrylic copolymer having an epoxy group.

[0036] Another aspect of the present invention provides a method for manufacturing a cutting die-bonding integrated film, which includes: a process of forming a photocurable pressure-sensitive adhesive layer on a substrate layer, wherein the photocurable pressure-sensitive adhesive layer is formed by a photocurable pressure-sensitive adhesive judged to be good by an evaluation method for the photocurable pressure-sensitive adhesive; and a process of forming an adhesive layer on the photocurable pressure-sensitive adhesive layer.

[0037] Another aspect of the present invention provides a method for manufacturing a semiconductor device, which includes: a process of attaching an adhesive layer of a diced die-bonding integrated film obtained by the manufacturing method to a semiconductor wafer; a process of singulating the semiconductor wafer, the adhesive layer, and the photocurable pressure-sensitive adhesive layer by dicing; a process of irradiating the photocurable pressure-sensitive adhesive layer with ultraviolet rays to form a cured product of the photocurable pressure-sensitive adhesive layer; a process of picking up a semiconductor element with the adhesive layer attached from the cured product of the photocurable pressure-sensitive adhesive layer; and a process of bonding the semiconductor element to a supporting substrate for mounting the semiconductor element via the adhesive layer.

[0038] The thickness of the semiconductor wafer can be less than 35 μm. Stealth cutting can be used for cutting.

[0039] Another aspect of the present invention provides a dicing die bonding integrated film including, in order, a base layer, a photocurable pressure-sensitive adhesive layer formed of a photocurable pressure-sensitive adhesive judged as good by the photocurable pressure-sensitive adhesive evaluation method, and an adhesive layer.

[0040] Effects of the Invention

[0041] According to the present invention, a novel evaluation method for a photocurable pressure-sensitive adhesive for a dicing die-bonding integrated film is provided. In addition, according to the present invention, a dicing die-bonding integrated film and a manufacturing method thereof based on the evaluation method for the photocurable pressure-sensitive adhesive are provided. Furthermore, according to the present invention, a manufacturing method for a semiconductor device using the dicing die-bonding integrated film is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic cross-sectional view showing one embodiment of a dicing die bonding integrated film.

[0043] Figure 2 (a) and Figure 2 (b) is a diagram showing an example of shape image distribution and phase image distribution of the surface of a cured product of the photocurable pressure-sensitive adhesive layer, Figure 2 (a) is the shape image distribution, Figure 2 (b) is the phase image distribution.

[0044] Figure 3 (a) and Figure 3 (b) is a diagram showing an example of the cross-sectional distribution of the surface of the cured product of the photocurable pressure-sensitive adhesive layer, Figure 3 (a) is the shape image distribution, Figure 3 (b) is Figure 3 Cross-sectional distribution of the wire drawing mark X along line iii-iii in (a).

[0045] Figure 4 (a) and Figure 4 (b) is a diagram showing an example of the cross-sectional distribution of the surface of the cured product of the photocurable pressure-sensitive adhesive layer, Figure 4 (a) is the shape image distribution, Figure 4 (b) is Figure 4 Cross-sectional distribution of the wire drawing mark Y along line iv-iv in (a).

[0046] Figure 5 is a schematic cross-sectional view for explaining one embodiment of a method for manufacturing a semiconductor device. Figure 5 (a), (b), (c), (d) and (e) are schematic cross-sectional views showing the respective steps.

[0047] Figure 6 is a schematic cross-sectional view for explaining one embodiment of a method for manufacturing a semiconductor device. Figure 6 (f), (g), (h) and (i) are schematic cross-sectional views showing the respective steps.

[0048] Figure 7It is a schematic cross-sectional view showing one embodiment of a semiconductor device. DETAILED DESCRIPTION

[0049] Hereinafter, embodiments of the present invention will be described with appropriate reference to the accompanying drawings. However, the present invention is not limited to the following embodiments. In the following embodiments, unless otherwise specified, the constituent elements (including processes, etc.) are not essential. The sizes of the constituent elements in each figure are conceptual, and the relative relationship between the sizes of the constituent elements is not limited to those shown in each figure.

[0050] The same is true for the numerical values ​​and their ranges in this specification, and the present invention is not limited thereto. In this specification, the numerical range represented by "~" represents the range in which the numerical values ​​recorded before and after "~" are respectively included as the minimum and maximum values. In the numerical range recorded in stages in this specification, the upper limit or lower limit recorded in one numerical range may also be replaced by the upper limit or lower limit of the numerical range recorded in another stage. In addition, in the numerical range recorded in this specification, the upper limit or lower limit of the numerical range may also be replaced by the value shown in the embodiment.

[0051] In this specification, (meth)acrylate refers to acrylate or its corresponding methacrylate. The same applies to other similar expressions such as (meth)acryloyl, (meth)acrylic acid copolymer, etc.

[0052] In this specification, "wire drawing" refers to the deformation of the pressure-sensitive adhesive between the adherend and the pressure-sensitive adhesive, and when the adherend and the pressure-sensitive adhesive are peeled off, the pressure-sensitive adhesive does not break between the adherend and the pressure-sensitive adhesive, but deforms greatly like a thread. "Wire drawing marks" refer to the marks (protrusions) observed on the surface of the pressure-sensitive adhesive due to partial shrinkage caused by the breakage of the pressure-sensitive adhesive after wire drawing occurs, partial shrinkage after large deformation, or partial shrinkage caused by the irreversible stretching of the pressure-sensitive adhesive or large deformation after peeling from the adherend.

[0053] [Evaluation method of light-curing pressure-sensitive adhesive]

[0054] An evaluation method for a photocurable pressure-sensitive adhesive for a dicing die-bonding integrated film according to one embodiment includes: a first step of preparing a dicing die-bonding integrated film having a substrate layer, a photocurable pressure-sensitive adhesive layer formed by a photocurable pressure-sensitive adhesive, and an adhesive layer laminated in sequence, irradiating the photocurable pressure-sensitive adhesive layer with ultraviolet rays under specific irradiation conditions to form a cured product of the photocurable pressure-sensitive adhesive layer, and measuring the peeling force when the adhesive layer and the cured product of the photocurable pressure-sensitive adhesive layer are peeled off under specific peeling conditions; a second step of preparing a substrate layer, a photocurable pressure-sensitive adhesive layer formed by a photocurable pressure-sensitive adhesive, and an adhesive layer laminated in sequence, The cutting die-bonding integrated film of the composite layer is processed under specific heating and cooling conditions, and the photocurable pressure-sensitive adhesive layer is irradiated with ultraviolet rays under specific irradiation conditions to form a cured product of the photocurable pressure-sensitive adhesive layer, the adhesive layer and the cured product of the photocurable pressure-sensitive adhesive layer are peeled off under specific peeling conditions, and the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off is observed using a scanning probe microscope to measure the number and width of wire drawing marks on the surface; and a third step of judging the quality of the photocurable pressure-sensitive adhesive based on the peeling force and the number and width of wire drawing marks.

[0055] Hereinafter, first, the photocurable pressure-sensitive adhesive to be evaluated and the dicing die bonding integrated film having a photocurable pressure-sensitive adhesive layer formed of the photocurable pressure-sensitive adhesive and the method for producing the same are described, then the factors affecting the stringing phenomenon are examined, and finally each process is described.

[0056] <Light-curing pressure-sensitive adhesive>

[0057] In the evaluation method of the photocurable pressure-sensitive adhesive of the present embodiment, the photocurable pressure-sensitive adhesive cured by ultraviolet irradiation can be the evaluation object. Hereinafter, as an example of the photocurable pressure-sensitive adhesive to be evaluated, a photocurable pressure-sensitive adhesive containing a (meth)acrylic acid copolymer having a reactive functional group, a photopolymerization initiator, and a crosslinking agent having two or more functional groups capable of reacting with the reactive functional group is described.

[0058] ((Meth)acrylic acid copolymer having reactive functional groups)

[0059] The (meth)acrylic copolymer having a reactive functional group can be obtained, for example, by copolymerizing one or two or more (meth)acrylate monomers (a1) or (meth)acrylic acid with one or two or more polymerizable compounds (a2) having a reactive functional group.

[0060] The (meth)acrylate monomer (a1) may be, for example, at least one selected from the group consisting of linear or branched alkyl (meth)acrylates, alicyclic (meth)acrylates, aromatic (meth)acrylates, alkoxy alkyl (meth)acrylates, alkoxy (poly)alkylene glycol (meth)acrylates, alkoxyalkoxyalkyl (meth)acrylates, and dialkylaminoalkyl (meth)acrylates.

[0061] Examples of the linear or branched alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, and tridecyl (meth)acrylate.

[0062] Examples of the alicyclic (meth)acrylate include cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate.

[0063] As an aromatic (meth)acrylate, phenoxyethyl (meth)acrylate etc. are mentioned, for example.

[0064] As an alkoxy alkyl (meth)acrylate, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, etc. are mentioned, for example.

[0065] Examples of the alkoxy (poly) alkylene glycol (meth)acrylate include methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, butoxytriethylene glycol (meth)acrylate, and methoxydipropylene glycol (meth)acrylate.

[0066] As an alkoxyalkoxyalkyl (meth)acrylate, 2-methoxyethoxyethyl (meth)acrylate, 2-ethoxyethoxyethyl (meth)acrylate, etc. are mentioned, for example.

[0067] Examples of the dialkylaminoalkyl (meth)acrylate include N,N-dimethylaminoethyl (meth)acrylate and N,N-diethylaminoethyl (meth)acrylate.

[0068] The polymerizable compound (a2) may have at least one reactive functional group selected from the group consisting of a hydroxyl group and an epoxy group. Hydroxyl groups and epoxy groups have good reactivity with compounds (b) having an isocyanate group or the like, and thus can be used appropriately. The polymerizable compound (a2) preferably has a hydroxyl group.

[0069] Examples of the polymerizable compound (a2) having a hydroxyl group as a reactive functional group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate.

[0070] Examples of the polymerizable compound (a2) having an epoxy group as a reactive functional group include (meth)acrylates having an epoxy group such as glycidyl (meth)acrylate and 3,4-epoxycyclohexyl (meth)acrylate.

[0071] The (meth)acrylic acid copolymer may contain (meth)acrylic acid as a monomer unit. In addition to the (meth)acrylate monomer (a1) and the polymerizable compound (a2), other polymerizable compounds may be contained as monomer units. Examples of other polymerizable compounds include aromatic vinyl compounds such as styrene and vinyltoluene.

[0072] The (meth)acrylic copolymer having a reactive functional group may also have a functional group capable of chain polymerization. That is, it may have a main chain composed of a (meth)acrylic copolymer having a reactive functional group and a side chain bonded to the main chain and containing a polymerizable double bond. The side chain containing a polymerizable double bond may be a (meth)acryloyl group, but is not limited thereto. The (meth)acrylic copolymer having a functional group capable of chain polymerization may be obtained in the following manner, wherein one or more compounds (b) including a functional group reactive with the reactive functional group of the (meth)acrylic copolymer having a reactive functional group and a functional group capable of chain polymerization are reacted, and a functional group capable of chain polymerization is introduced into the side chain of the (meth)acrylic copolymer.

[0073] Examples of the functional group that reacts with the reactive functional group (epoxy group, hydroxyl group, etc.) include an isocyanate group and the like.

[0074] Specific examples of the compound (b) having an isocyanate group include 2-methacryloyloxyethyl isocyanate (for example, manufactured by SHOWA DENKO KK, trade name "Karenz MOI").

[0075] The content of the compound (b) may be 0.3 to 1.5 mmol / g relative to the (meth)acrylic acid copolymer having a reactive functional group.

[0076] The acid value of the (meth)acrylic acid copolymer having a reactive functional group may be, for example, 0 to 150 mgKOH / g. The hydroxyl value of the (meth)acrylic acid copolymer having a reactive functional group may be, for example, 0 to 150 mgKOH / g. The acid value and the hydroxyl value are measured according to JIS K0070.

[0077] The weight average molecular weight (Mw) of the (meth)acrylic copolymer having a reactive functional group may be 100,000 to 1,000,000, 200,000 to 800,000, or 300,000 to 700,000. The weight average molecular weight is a polystyrene conversion value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

[0078] (Photopolymerization Initiator)

[0079] As the photopolymerization initiator, there is no particular limitation as long as it is a photopolymerization initiator that starts polymerization by irradiation with ultraviolet rays, and examples thereof include photoradical polymerization initiators. As the photoradical polymerization initiator, examples thereof include benzoin ketal such as 2,2-dimethoxy-1,2-diphenylethane-1-one; α-hydroxyketones such as 1-hydroxycyclohexylphenyl ketone; α-aminoketones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butane-1-one; oxime esters such as 1-[4-(phenylthio)phenyl]-1,2-octanedione-2-(benzoyl)oxime; and bis(2,4,6-trimethylbenzoyl)phenyl oxide. Phosphine oxides such as phosphine; 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer; benzophenone compounds such as benzophenone and N,N,N',N'-tetramethyl-4,4'-diaminobenzophenone; quinone compounds such as 2-ethylanthraquinone; benzoin ethers such as benzoin methyl ether; benzoin compounds such as benzoin; benzyl compounds such as benzyl dimethyl ketal; acridine compounds such as 9-phenylacridine; N-phenylglycine, coumarin, etc. These may be used alone or in combination with an appropriate sensitizer.

[0080] The content of the photopolymerization initiator may be 0.1 to 10 parts by mass, or 0.5 to 5 parts by mass, relative to 100 parts by mass of the (meth)acrylic copolymer.

[0081] (Crosslinking agent)

[0082] The crosslinking agent is not particularly limited as long as it is a compound having two or more functional groups that can react with the reactive functional groups (epoxy, hydroxyl, etc.) of the (meth)acrylic copolymer having a reactive functional group. Examples of the bond formed by the reaction between the crosslinking agent and the (meth)acrylic copolymer having a reactive functional group include an ester bond, an ether bond, an amide bond, an imide bond, a urethane bond, and a urea bond.

[0083] Examples of the crosslinking agent include compounds having two or more isocyanate groups in one molecule. When such a compound is used, since it easily reacts with the reactive functional group of the (meth)acrylic copolymer, it tends to be easy to control adhesion and stringing.

[0084] Examples of the compound having two or more isocyanate groups in one molecule include isocyanate compounds such as 2,4-toluene diisocyanate, 2,6-toluene 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.

[0085] Specific examples of the compound having two or more isocyanate groups in one molecule include polyfunctional isocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name “Coronate L”).

[0086] The crosslinking agent may be a reaction product (isocyanate group-containing oligomer) of the isocyanate compound and a polyol having two or more hydroxyl groups in one molecule. Examples of the polyol having two or more hydroxyl groups in one molecule include ethylene glycol, propylene glycol, butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, glycerol, pentaerythritol, dipentaerythritol, 1,4-cyclohexanediol, and 1,3-cyclohexanediol.

[0087] The crosslinking agent may be a reaction product (isocyanate-containing oligomer) of a polyfunctional isocyanate having two or more isocyanate groups in one molecule and a polyol having three or more hydroxyl groups in one molecule. By using such an isocyanate-containing oligomer as a crosslinking agent, the photocurable pressure-sensitive adhesive layer 20 tends to form a denser crosslinked structure.

[0088] The content of the cross-linking agent may be, for example, 3 to 50% by mass relative to the total mass of the (meth)acrylic acid copolymer.

[0089] <Dicing die bonding integrated film and method of manufacturing the same>

[0090] Figure 1 1 is a schematic cross-sectional view showing one embodiment of a dicing die bonding integrated film. The dicing die bonding integrated film 1 includes a base material layer 10 , a photocurable pressure-sensitive adhesive layer 20 formed of a photocurable pressure-sensitive adhesive, and an adhesive layer 30 laminated in this order.

[0091] (Base material layer)

[0092] The substrate layer 10 can use a known polymer sheet or film, and there is no particular limitation as long as it is made of a material that can expand in the die bonding process. Examples of such materials include polyolefins such as crystalline polypropylene, non-crystalline polypropylene, high-density polyethylene, medium-density polyethylene, low-density polyethylene, ultra-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, alternating) copolymers; ethylene-propylene copolymers; ethylene-butene copolymers; ethylene-hexene copolymers; polyurethanes; polyesters such as polyethylene terephthalate and polyethylene naphthalate; polycarbonates; polyimides; polyetheretherketones; polyimides; polyetherimides; polyamides; fully aromatic polyamides; polyphenylene sulfides; aramid (paper); glass; glass cloth; fluororesins; polyvinyl chloride; polyvinylidene chloride; cellulose resins; silicone resins, etc. These materials may be materials mixed with plasticizers, silica, anti-blocking materials, slip agents, antistatic agents, and the like.

[0093] Among them, the substrate layer 10 can have a surface with at least one material selected from polyethylene, polypropylene, polyethylene-polypropylene random copolymer and polyethylene-polypropylene block copolymer as the main component from the viewpoints of Young's modulus, stress relaxation, melting point and other characteristics, price, and waste recycling after use, and the surface is in contact with the photocurable pressure-sensitive adhesive layer 20. The substrate layer 10 can be a single layer or a multilayer of more than two layers formed by different materials. From the viewpoint of controlling the adhesion with the photocurable pressure-sensitive adhesive layer 20 described later, the substrate layer 10 can be subjected to surface roughening treatment such as corona discharge treatment and matte treatment as needed.

[0094] The thickness of the substrate layer 10 may be, for example, 70 to 120 μm or 80 to 100 μm. If the thickness of the substrate layer 10 is 70 μm or more, there is a tendency to further suppress damage caused by expansion. If the thickness of the substrate layer 10 is 120 μm or less, there is a tendency that the stress during pickup easily reaches the adhesive layer, and the pickup property is more excellent.

[0095] (Photocurable pressure-sensitive adhesive layer)

[0096] The photocurable pressure-sensitive adhesive layer 20 is a layer formed by the photocurable pressure-sensitive adhesive. The photocurable pressure-sensitive adhesive layer 20 is formed on the substrate layer 10. As a method for forming the photocurable pressure-sensitive adhesive layer 20 on the substrate layer 10, for example, there can be cited a method of preparing a varnish for forming a photocurable pressure-sensitive adhesive layer, applying the varnish to the substrate layer 10, removing the volatile components of the varnish, and forming the photocurable pressure-sensitive adhesive layer 20; applying the varnish to a film subjected to a release treatment, removing the volatile components of the varnish, forming the photocurable pressure-sensitive adhesive layer 20, and transferring the obtained photocurable pressure-sensitive adhesive layer 20 to the substrate layer 10.

[0097] The varnish for forming a photocurable pressure-sensitive adhesive layer contains a (meth)acrylic copolymer having a reactive functional group, a photopolymerization initiator, a crosslinking agent having two or more functional groups capable of reacting with the reactive functional group, and an organic solvent. The organic solvent can dissolve the (meth)acrylic copolymer having a reactive functional group, the photopolymerization initiator, and the crosslinking agent having two or more functional groups capable of reacting with the reactive functional group, and can volatilize by heating. As such organic solvents, for example, aromatic hydrocarbons such as toluene and xylene; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; alcohols such as methanol, ethanol, ethylene glycol, and propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; polyol alkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol dimethyl ether; polyol alkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. These can be used alone or in combination of two or more. The solid content concentration of the varnish can be 10 to 60% by mass based on the total mass of the varnish.

[0098] The thickness of the photocurable pressure-sensitive adhesive layer 20 may be, for example, 1 to 200 μm, 3 to 50 μm, or 5 to 30 μm.

[0099] (Adhesive layer)

[0100] The adhesive layer 30 is a layer formed by an adhesive. There is no particular limitation on the adhesive as long as it is an adhesive used in the field of die bonding films. As an example of an adhesive, an adhesive containing an epoxy resin, an epoxy resin curing agent, and a (meth) acrylic copolymer having an epoxy group is described below. According to the adhesive layer 30 formed by such an adhesive, the adhesion between the chip and the substrate and between the chips is excellent, and the electrode embedding property, the wire embedding property, etc. can be given, and bonding can be performed at a low temperature in the die bonding process.

[0101] Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol F novolac epoxy resin, epoxy resins containing dicyclopentadiene skeletons, stilbene epoxy resins, epoxy resins containing triazine skeletons, epoxy resins containing fluorene skeletons, trisphenol methane epoxy resins, biphenyl epoxy resins, xylylene epoxy resins, biphenyl aralkyl epoxy resins, naphthalene epoxy resins, polyfunctional phenols, diglycidyl ether compounds of polycyclic aromatics such as anthracene, etc. These may be used alone or in combination of two or more.

[0102] Epoxy resin curing agent can be, for example, phenolic resin. As long as phenolic resin has phenolic hydroxyl group in molecule, it can be used without particular restriction. As phenolic resin, for example, phenol, cresol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol and / or α-naphthol, β-naphthol, dihydroxynaphthalene and other phenols and formaldehyde and other compounds with aldehyde groups condensed or co-condensed under acidic catalysts can be cited. Novolac type phenolic resin, phenols and / or naphthols and dimethoxy-p-xylene or bis(methoxymethyl)biphenyl synthesized phenol aralkyl resin, naphthol aralkyl resin, etc. can be cited. These can be used alone or in combination of two or more.

[0103] The (meth)acrylic copolymer having an epoxy group may be a copolymer in which the (meth)acrylic acid glycidyl ester as a raw material is adjusted to an amount of 0.5 to 6% by mass relative to the obtained copolymer. When the amount is 0.5% by mass or more, there is a tendency to easily obtain high adhesion, and when the amount is 6% by mass or less, there is a tendency to suppress gelation. The remainder of the (meth)acrylic acid glycidyl ester may be a mixture of (meth)acrylic acid alkyl esters having an alkyl group with 1 to 8 carbon atoms such as methyl (meth)acrylate, and styrene, acrylonitrile, etc. The (meth)acrylic acid alkyl ester may contain ethyl (meth)acrylate and / or butyl (meth)acrylate. The mixing ratio of each component can be adjusted in consideration of the Tg (glass transition temperature) of the obtained (meth)acrylic copolymer having an epoxy group. If Tg is above -10°C, the viscosity of the adhesive layer 30 in the B-stage state tends to be better, and there is a tendency to be excellent in handling. The upper limit value of Tg of the (meth)acrylic copolymer having an epoxy group may be, for example, 30°C.

[0104] The weight average molecular weight of the (meth)acrylic copolymer having an epoxy group may be 100,000 or more, 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, there is a tendency to control the decrease in the filling property between the semiconductor chip and the supporting substrate. The weight average molecular weight is a polystyrene conversion value obtained by gel permeation chromatography (GPC) using a standard curve based on standard polystyrene.

[0105] The adhesive may further contain a curing accelerator such as a tertiary amine, imidazoles, or a quaternary ammonium salt as required. Examples of the curing accelerator include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazole. These may be used alone or in combination of two or more.

[0106] The binder may also contain an inorganic filler as needed. 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 silicon dioxide, amorphous silicon dioxide, etc. These may be used alone or in combination of two or more.

[0107] The adhesive layer 30 is formed on the photocurable pressure-sensitive adhesive layer 20. As a method for forming the adhesive layer 30 on the photocurable pressure-sensitive adhesive layer 20, for example, there can be cited a method of preparing a varnish for forming an adhesive layer, applying the varnish on a film subjected to a demolding treatment, forming the adhesive layer 30, and transferring the obtained adhesive layer 30 onto the photocurable pressure-sensitive adhesive layer 20. The varnish for forming an adhesive layer contains an epoxy resin, an epoxy resin curing agent, a (meth) acrylic copolymer having an epoxy group, and an organic solvent. The organic solvent may be the same as the organic solvent exemplified in the organic solvent used in the varnish for forming a photocurable pressure-sensitive adhesive layer.

[0108] The thickness of the adhesive layer 30 may be, for example, 1 to 300 μm, 5 to 150 μm, or 10 to 100 μm.

[0109] [Factors affecting wire drawing]

[0110] Wiredrawing can be caused by the interaction at the interface of the cured product of the adhesive layer and the photocurable pressure-sensitive adhesive layer. Therefore, as one of the influencing factors of the wiredrawing phenomenon, the type and content of the crosslinking agent are listed. For example, if the content of the crosslinking agent is reduced, there is a tendency that the number of wiredrawing traces increases and the width of the traces of the wiredrawing traces also becomes larger. Therefore, by adjusting the type and content of the crosslinking agent, the number of wiredrawing traces and the width of the traces can be controlled. In addition, as an influencing factor of the wiredrawing phenomenon other than the composition of the photocurable pressure-sensitive adhesive, the coating conditions are cited. The number of wiredrawing traces and the width of the traces can be controlled by changing the coating conditions such as the coating speed, the coating temperature, and the air volume. Furthermore, as an influencing factor of the wiredrawing phenomenon, the conditions when the adhesive layer and the photocurable pressure-sensitive adhesive layer are bonded during the production of the cutting die bonding integrated film, the surface properties (surface roughness, surface free energy, etc.) of the adhesive layer and the photocurable pressure-sensitive adhesive layer, the molecular weight, polarity, and glass transition point of the (meth) acrylic copolymer with reactive functional groups, etc. can be cited.

[0111] <1st step>

[0112] In this step, first, a dicing die bonding integrated film for evaluation is prepared in which a base material layer, a photocurable pressure-sensitive adhesive layer formed of a photocurable pressure-sensitive adhesive to be evaluated, and an adhesive layer are sequentially laminated.

[0113] In the evaluation dicing die bonding integrated film, the types of the substrate layer, the photocurable pressure-sensitive adhesive layer, and the adhesive layer are not particularly limited, and any selected dicing die bonding integrated film can be used. The thickness of the photocurable pressure-sensitive adhesive formed by the photocurable pressure-sensitive adhesive as the evaluation object can be, for example, 10 μm. The thickness of the adhesive layer can be, for example, 10 μm.

[0114] Next, the photocurable pressure-sensitive adhesive layer is irradiated with ultraviolet rays under the following irradiation conditions to cure the photocurable pressure-sensitive adhesive and form a cured product of the photocurable pressure-sensitive adhesive layer. The light source of ultraviolet rays can be appropriately selected according to the type of photopolymerization initiator used. The light source of ultraviolet rays is not particularly limited, but can be one selected from the group consisting of a low-pressure mercury lamp, a far ultraviolet lamp, an excimer ultraviolet lamp, a high-pressure mercury lamp and a metal halide lamp. Among them, the light source of ultraviolet rays preferably has a high-pressure mercury lamp with a central wavelength of 365nm. In addition, in the irradiation of ultraviolet rays, in order to reduce the influence of the heat generated by the light source, a cold mirror or the like can also be used in combination.

[0115] (irradiation conditions)

[0116] Irradiation intensity: 70mW / cm 2

[0117] Total light intensity: 150mJ / cm 2

[0118] The irradiation temperature in the ultraviolet irradiation conditions may be 60° C. or lower or 40° C. or lower.

[0119] Finally, the peeling force (low angle peeling strength) when peeling the cured product of the adhesive layer and the photocurable pressure-sensitive adhesive layer under the following peeling conditions is measured. When peeling the cured product of the adhesive layer and the photocurable pressure-sensitive adhesive layer, it is preferably carried out by attaching a pressure-sensitive adhesive tape, a support tape, etc. to the adhesive layer and stretching these tapes using a peeling strength measuring device that can adjust the peeling angle.

[0120] (Peeling conditions)

[0121] Temperature: 25±5℃

[0122] Humidity: 55±10%

[0123] Peeling angle: 30°

[0124] Peeling speed: 600mm / min

[0125] The lower the peeling angle, the more the influence of the base material layer on the peeling force tends to be eliminated, but it is difficult to measure when it is less than 15°. Therefore, 30° is suitable as the test condition for low-angle peel strength.

[0126] <Step 2>

[0127] In this step, first, a dicing die bonding integrated film for evaluation is prepared in which a base layer, a photocurable pressure-sensitive adhesive layer formed of a photocurable pressure-sensitive adhesive to be evaluated, and an adhesive layer are sequentially laminated. The dicing die bonding integrated film for evaluation in the second step may be the same as the dicing die bonding integrated film for evaluation in the first step, but a film that has not been subjected to the peeling force measurement in the first step is used.

[0128] Next, the photocurable pressure-sensitive adhesive layer of the dicing die bonding integrated film for evaluation is treated under the following heating and cooling conditions. When the photocurable pressure-sensitive adhesive layer is not treated under the heating and cooling conditions, the adhesion between the photocurable pressure-sensitive adhesive layer and the adhesive layer may be insufficient, and when the adhesive layer and the cured product of the photocurable pressure-sensitive adhesive layer are peeled off, there is a tendency that wiredrawing marks are difficult to observe. The following heating and cooling conditions are assumed to be a wafer lamination process for semiconductor devices, and there is a tendency that wiredrawing marks are more easily observed. The heating treatment under the heating and cooling conditions is preferably performed from the substrate layer side using a heater or the like. In addition, the substrate layer is preferably a substrate layer that does not deform, such as wrinkles or relaxation, during the heating treatment (65°C, 15 minutes). During the heating treatment, in order to prevent the dicing die bonding integrated film for evaluation from bending, it is preferably heated while being suppressed with a heat-resistant cloth or the like. The surface pressure at this time can be 0.1 g / cm 2If the surface pressure is too high, the photocurable pressure-sensitive adhesive layer and the adhesive layer will be too close to each other, and there is a possibility of excessive wire drawing marks. In order to prevent the curing of the photocurable pressure-sensitive adhesive layer, it is preferably carried out while shielding from light.

[0129] (Heating and cooling conditions)

[0130] Heat treatment: 65°C, 15 minutes

[0131] Cooling: air cooling to 25±5℃

[0132] Next, the photocurable pressure-sensitive adhesive layer is irradiated with ultraviolet rays under the same irradiation conditions as in the first step to form a cured product of the photocurable pressure-sensitive adhesive layer, and the adhesive layer is stretched under the same peeling conditions as in the first step to peel off the adhesive layer and the cured product of the photocurable pressure-sensitive adhesive layer. The substrate layer having the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off is recovered as a measurement sample. At this time, the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off is recovered in a manner that does not contaminate the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off. In addition, it is preferred that the substrate layer having the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off is cut into a size of 5 mm × 5 mm as a measurement sample.

[0133] Finally, the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off is observed using a scanning probe microscope, and the number and width of the wiredrawing marks on the surface are measured. From the viewpoint of avoiding the influence of static electricity, it is preferred to use a conventional carbon double-sided tape used in scanning electron microscope observations, etc. when fixing the measurement sample to the scanning probe microscope. In addition, from the viewpoint of avoiding the influence of static electricity, observation using a scanning probe microscope is preferably performed after being fixed for more than half a day (12 hours) and left to stand for static elimination, or after appropriately eliminating static electricity using a static eliminator, etc.

[0134] The scanning probe microscope probe is preferably provided with a cantilever with a low spring constant which is most suitable for measuring the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off. Observation using the scanning probe microscope is preferably performed in a dynamic mode (DFM).

[0135] Wiredrawing marks are marks (protrusions) observed on the surface of the cured product of the photocurable pressure-sensitive adhesive layer. Phase image data of the surface of the cured product of the photocurable pressure-sensitive adhesive layer can be obtained, and the parts in the phase image where the hardness is obviously different from the surrounding areas are regarded as wiredrawing marks. The number of wiredrawing marks is the number of parts in the phase image where the hardness is obviously different from the surrounding areas.

[0136] The trace width of the wire drawing trace can be obtained as follows: First, a scanning probe microscope is used to obtain a shape image distribution and a phase image distribution of the surface of the cured product of the photocurable pressure-sensitive adhesive layer including a portion whose hardness is significantly different from that of the surrounding area in the phase image. Figure 2 : is a diagram showing an example of shape image distribution and phase image distribution of the surface of a cured product of a photocurable pressure-sensitive adhesive layer. Figure 2 (a) is the shape image distribution, Figure 2 (b) is the phase image distribution. Figure 2 The brushing marks observed in the shape image distribution of (a) are raised portions that are curved lines protruding upward, and are represented by the lightest color (for example, white in the case of a black and white image). On the other hand, in the phase image distribution, a smaller phase difference than the surroundings means that it is harder than the surroundings. Figure 2 The wire drawing marks observed in the phase image distribution of (b) are because the photocurable pressure-sensitive adhesive layer is stretched to the limit, so the parts with a phase difference of less than 50% compared with the surroundings are represented by the darkest color (for example, black in the case of a black and white image). In this way, wire drawing marks can be observed not only from the shape image distribution but also from the phase image distribution. Next, according to the obtained Figure 2 The shape image distribution of (a) is obtained by using commercially available image processing software (such as image processing software attached to a scanning probe microscope) to output the cross-sectional distribution of the cross-sectional line where the trace width of each wire drawing mark is the largest for all the wire drawing marks to be measured. Figure 3 1 is a diagram showing an example of the cross-sectional distribution of the surface of the cured product of the photocurable pressure-sensitive adhesive layer. Figure 3 (a) is the shape image distribution, Figure 3 (b) is Figure 3 The cross-sectional distribution of the wire drawing mark X along the line iii-iii in (a). Figure 3 (b) is a cross-sectional distribution when the height of the two ends of the drawing mark is substantially the same (for example, less than 1 nm). In this cross-sectional distribution, the width Wx between the two ends (minimum values) of the drawing mark X can be set to the trace width of the drawing mark X. On the other hand, Figure 4 1 is a diagram showing an example of the cross-sectional distribution of the surface of the cured product of the photocurable pressure-sensitive adhesive layer. Figure 4 (a) is the shape image distribution, Figure 4 (b) is Figure 4 Cross-sectional distribution of the wire drawing mark Y along line iv-iv in (a). Figure 4(b) is a cross-sectional distribution when there is a difference in height between the two ends of the observed wire drawing mark (for example, more than 1 nm). In this case, the end (minimum value) closer to the vertex height of the wire drawing mark Y can be set as the reference height Hy, and the width Wy at the reference height Hy can be set as the trace width of the wire drawing mark Y.

[0137] <Step 3>

[0138] In this process, the quality of the photocurable pressure-sensitive adhesive is determined based on the peeling force and the number and width of the stringing marks. The peeling force and the number and width of the stringing marks used as the evaluation criteria can be appropriately set according to the thickness of the semiconductor wafer, etc.

[0139] The third step may be a step of judging the quality of the photocurable pressure-sensitive adhesive based on whether the peeling force and the number and width of the wire drawing marks satisfy the following conditions (a) and (b). The dicing die bonding integrated film having a photocurable pressure-sensitive adhesive layer formed by a photocurable pressure-sensitive adhesive satisfying the following conditions (a) and (b) can be preferably used in a dicing process (e.g., invisible dicing, etc.) used for semiconductor wafers with a relatively thin thickness (e.g., less than 35 μm).

[0140] Condition (a): Peel force is 0.70 N / 25 mm or less.

[0141] Condition (b): After the adhesive layer is peeled off, there is a 25 μm×25 μm area (sometimes referred to as a "specific area") with 15 or more wire drawing marks on the surface of the cured product of the photocurable pressure-sensitive adhesive layer, and the median width of the wire drawing marks in the area is 120 to 200 nm.

[0142] When the photocurable pressure-sensitive adhesive satisfying condition (a) is applied to the dicing die bonding integrated film, the success rate of picking up tends to be further improved. The peeling force in condition (a) may be 0.65 N / 25 mm or less or 0.63 N / 25 mm or less. The lower limit of the peeling force in condition (a) is not particularly limited, but may be 0.10 N / 25 mm or more.

[0143] When the photocurable pressure-sensitive adhesive satisfying the condition (b) is applied to the dicing die bonding integrated film, there is a tendency that the peeling time of pickup becomes shorter.

[0144] Based on the presence of a specific area on the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off, there is a tendency that stress propagation becomes good and the peeling speed increases. The number of traces of the wiredrawing marks present in the specific area can be more than 15 or more than 20, or it can be less than 70, less than 60 or less than 50. Regarding the peeling speed, both contribute to the existence of the specific area and the trace width of the wiredrawing marks present in the specific area. In a specific area, when the number of traces of the wiredrawing marks is more than 15, there is a tendency that stress propagation is high and the peeling speed is accelerated. In a specific area, when the number of traces of the wiredrawing marks is less than 70, there is a tendency to suppress excessive increase in peeling force.

[0145] In the case where there are specific areas with more than 15 traces of wire drawing marks on the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off, the median of the trace width of the wire drawing marks existing in these specific areas is calculated. Among them, the median refers to the value located in the center when a limited number of data is arranged in order from small to large, and when the number of data is an even number, it refers to the average value of the values ​​close to the center. For example, when the number of wire drawing marks is 15, the trace width of the 8th wire drawing mark when the trace width of the wire drawing marks is arranged in order from small to large is the median, and when the number of wire drawing marks is 16, the average value of the trace width of the 8th wire drawing mark and the trace width of the 9th wire drawing mark when the trace width of the wire drawing marks is arranged in order from small to large is the median. The median of the trace width of the wire drawing marks existing in the specific area can be more than 130nm or more than 150nm, or it can be less than 190nm or less than 180nm. When the median width of the wire drawing marks existing in a specific region is 120 nm or more, the wire drawing breakage impact is easily propagated, and the peeling rate tends to increase. When the median width of the wire drawing marks existing in a specific region is 200 nm or less, the wire drawing breakage is easily caused, and the peeling rate tends to increase.

[0146] [Method for manufacturing dicing die bonding integrated film]

[0147] A method for manufacturing a dicing die-bonding integrated film according to one embodiment includes: a step of forming a photocurable pressure-sensitive adhesive layer formed of a photocurable pressure-sensitive adhesive judged as good by the photocurable pressure-sensitive adhesive evaluation method on a substrate layer; and a step of forming an adhesive layer on the photocurable pressure-sensitive adhesive layer. The substrate layer and the adhesive layer may be the same as those exemplified in the photocurable pressure-sensitive adhesive evaluation method. The method for forming the photocurable pressure-sensitive adhesive layer and the method for forming the adhesive layer may also be the same as those exemplified in the photocurable pressure-sensitive adhesive evaluation method.

[0148] [Dicing and Die Bonding Integrated Film]

[0149] The dicing die bonding integrated film of one embodiment includes a substrate layer, a photocurable pressure-sensitive adhesive layer formed of a photocurable pressure-sensitive adhesive judged as good by the photocurable pressure-sensitive adhesive evaluation method, and an adhesive layer in this order. The substrate layer and the adhesive layer may be the same as those exemplified in the photocurable pressure-sensitive adhesive evaluation method.

[0150] [Method for manufacturing semiconductor device (semiconductor package)]

[0151] Figure 5 and Figure 6 It is a schematic cross-sectional view for illustrating an embodiment of a method for manufacturing a semiconductor device. The method for manufacturing a semiconductor device of this embodiment includes: a process of attaching the adhesive layer 30 of the diced die bonding integrated film 1 obtained by the manufacturing method to the semiconductor wafer W2 (wafer lamination process); a process of singulating the semiconductor wafer W2, the adhesive layer 30 and the photocurable pressure-sensitive adhesive layer 20 (dicing process); a process of irradiating the photocurable pressure-sensitive adhesive layer 20 with ultraviolet rays (ultraviolet irradiation process); a process of picking up a semiconductor element (a semiconductor element 50 with an adhesive layer) attached with an adhesive layer 30a from a base layer 10 (picking up process) and a process of bonding the semiconductor element 50 with an adhesive layer to a supporting substrate 60 for mounting a semiconductor element via the adhesive layer 30a (semiconductor element bonding process).

[0152] The dicing in the dicing step is not particularly limited, and examples thereof include blade dicing, laser dicing, stealth dicing, etc. When the thickness of the semiconductor wafer W2 is 35 μm or less, stealth dicing may be used for dicing. Hereinafter, a method of mainly using stealth dicing as dicing will be described in detail.

[0153] <Modified layer forming step>

[0154] When stealth dicing is used for dicing, the method for manufacturing a semiconductor device may include a modified layer forming step before the wafer lamination step.

[0155] First, a semiconductor wafer W1 having a thickness H1 is prepared. The thickness H1 of the semiconductor wafer W1 on which the modified layer is formed may be greater than 35 μm. Next, a protective film 2 (see FIG. 2 ) is attached to one main surface of the semiconductor wafer W1. Figure 5 The surface to which the protective film 2 is attached is preferably the circuit surface of the semiconductor wafer W1. The protective film 2 may be a back grinding tape used in back grinding (back grinding) of the semiconductor wafer. Next, the semiconductor wafer W1 is irradiated with laser light to form a modified layer 4 (refer to Figure 5(b)), the side (back side) of the semiconductor wafer W1 opposite to the surface on which the protective film 2 is attached is back ground (back grinding) and polished (grinded), thereby producing a semiconductor wafer W2 having a modified layer 4 (reference Figure 5 (c)). The thickness H2 of the obtained semiconductor wafer W2 can be 35 μm or less.

[0156] <Wafer Lamination Process>

[0157] Next, the adhesive layer 30 of the dicing die bonding integrated film 1 is placed in a predetermined device. Next, the dicing die bonding integrated film 1 is attached to the main surface Ws of the semiconductor wafer W2 via the adhesive layer 30 (see Figure 5 (d)), peeling off the protective film 2 of the semiconductor wafer W2 (reference Figure 5 (e)).

[0158] <Cutting process>

[0159] Next, at least the semiconductor wafer W2 and the adhesive layer 30 are cut into individual pieces by dicing (see Figure 6 (f)). When stealth dicing is used for dicing, the individual pieces can be separated by cold expansion and heat shrinkage.

[0160] <Ultraviolet irradiation process>

[0161] Next, the photocurable pressure-sensitive adhesive layer 20 is irradiated with ultraviolet rays to cure the photocurable pressure-sensitive adhesive in the photocurable pressure-sensitive adhesive layer 20, thereby forming a cured product of the photocurable pressure-sensitive adhesive layer (a layer containing a cured product of the photocurable pressure-sensitive adhesive) (see Figure 6 (g)). Therefore, the adhesive force between the photocurable pressure-sensitive adhesive layer 20 and the adhesive layer 30 can be reduced. In the ultraviolet irradiation, ultraviolet rays with a wavelength of 200 to 400 nm are preferably used. The ultraviolet irradiation conditions are preferably adjusted to an illumination of 30 to 240 mW / cm 2 The irradiation dose is 200~500mJ / cm 2 .

[0162] <Pick-up process>

[0163] Next, the cut semiconductor elements 50 with adhesive layers are separated from each other by expanding the substrate layer 10, and the semiconductor elements 50 with adhesive layers ejected from the substrate layer 10 side by the ejector pins 42 are sucked by the suction chuck 44 and picked up from the cured product 20ac of the photocurable pressure-sensitive adhesive layer (see FIG. Figure 6(h)). In addition, the semiconductor element 50 with an adhesive layer has a semiconductor element Wa and an adhesive layer 30a. The semiconductor element Wa is obtained by cutting and dividing the semiconductor wafer W2, and the adhesive layer 30a is obtained by cutting and dividing the adhesive layer 30. The cured product 20ac of the photocurable pressure-sensitive adhesive layer is obtained by cutting and dividing the cured product of the photocurable pressure-sensitive adhesive layer. The cured product 20ac of the photocurable pressure-sensitive adhesive layer may remain on the substrate layer 10 when picking up the semiconductor element 50 with an adhesive layer. In the picking-up process, expansion is not necessarily required, but by expansion, the picking-up property can be further improved.

[0164] The ejection amount by the ejector pin 42 can be appropriately set. Furthermore, from the perspective of ensuring sufficient pickup performance even for extremely thin wafers, for example, two-stage or three-stage pickup can be performed. In addition, the semiconductor element 50 with an adhesive layer can be picked up by a method other than the method using the suction chuck 44.

[0165] <Semiconductor device bonding process>

[0166] After the semiconductor element 50 with the adhesive layer is picked up, the semiconductor element 50 with the adhesive layer is bonded to the semiconductor element mounting support substrate 60 via the adhesive layer 30a by thermocompression bonding (see Figure 6 (i)). A plurality of semiconductor elements 50 with adhesive layers may be bonded to a semiconductor element mounting support substrate 60.

[0167] Figure 7 is a cross-sectional view schematically showing one embodiment of a semiconductor device. Figure 7 The semiconductor device 100 shown can be manufactured by the above-mentioned steps, and further includes the following manufacturing method: a step of electrically connecting the semiconductor element Wa to the semiconductor element mounting support substrate 60 by means of a bonding wire 70; and a step of resin-sealing the semiconductor element Wa on the surface 60a of the semiconductor element mounting support substrate 60 using a resin sealing material 80. On the surface of the semiconductor element mounting support substrate 60 on the side opposite to the surface 60a, solder balls 90 can be formed for electrical connection with an external substrate (motherboard).

[0168] Example

[0169] The present invention will be described in more detail below by way of examples, but the present invention is not limited to these examples. Unless otherwise specified, commercially available reagents were used as compounds.

[0170] [Preparation of dicing die bonding integrated film]

[0171] (Preparation of (meth)acrylic acid copolymer solutions A to E)

[0172] In a 2000mL autoclave equipped with a Three-One Motor, a stirring blade and a nitrogen inlet pipe, 2-ethylhexyl acrylate (2EHA), 2-hydroxyethyl acrylate (HEA) and methacrylic acid (MAA) were added in the proportions (unit: mass parts) shown in Table 1, and 127 mass parts of ethyl acetate and 0.04 mass parts of azobisisobutyronitrile were added. Stir it until it is uniform, and bubble it at a flow rate of 500ml / min for 60 minutes to degas the dissolved oxygen in the system. Then, the temperature was raised to 78°C in 1 hour, and polymerization was carried out for 6 hours while maintaining 78-83°C. Then, the reaction solution was transferred to a 2000mL autoclave equipped with a Three-One Motor, a stirring blade and a nitrogen inlet pipe, and after heating for 4.5 hours at 120°C and 0.28MPa, it was cooled to room temperature (25°C, the same below). Then, 98 mass parts of ethyl acetate were further added for dilution. 0.05 parts by mass of hydroquinone monomethyl ether as a polymerization inhibitor and 0.02 parts by mass of dioctyltin dilaurate as a urethanization catalyst were added thereto, and 10 parts by mass of 2-methacryloyloxyethyl isocyanate (manufactured by SHOWA DENKO KK, trade name "Karenz MOI") as a compound having a functional group capable of chain polymerization was added, and the mixture was reacted at 70° C. for 6 hours and cooled to room temperature. Then, ethyl acetate was added so that the nonvolatile component (solid content) content was 35% by mass, thereby obtaining (meth)acrylic acid copolymer solutions A to E having a hydroxyl group as a reactive functional group.

[0173] The acid value and hydroxyl value of the (meth)acrylic acid copolymer in the (meth)acrylic acid copolymer solution A to E were measured according to JIS K0070. The results are shown in Table 1. In addition, the obtained acrylic resin was vacuum dried at 60°C overnight, and the obtained solid component was subjected to elemental analysis using a fully automatic elemental analyzer vario EL manufactured by Elementar, and the content of the introduced 2-methacryloyloxyethyl isocyanate was calculated from the nitrogen content. The results are shown in Table 1. Furthermore, SD-8022 / DP-8020 / RI-8020 manufactured by TOSOH CORPORATION was used as a GPC device, Gelpack GL-A150-S / GL-A160-S manufactured by Hitachi Chemical Co., Ltd. was used as a column, and tetrahydrofuran was used as an eluent to measure the weight average molecular weight (Mw) converted to polystyrene. The results are shown in Table 1.

[0174] [Table 1]

[0175]

[0176] <Production Example 1: Preparation of Dicing Die Bonding Integrated Film A>

[0177] (Preparation of Cutting Film)

[0178] 100 parts by mass of the (meth)acrylic acid copolymer solution A prepared as a (meth)acrylic acid copolymer having a reactive functional group, 0.5 parts by mass of 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Speciality Chemicals, IRGACURE184) as a photopolymerization initiator, and 2 parts by mass of a multifunctional isocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate L", solid content 75%) as a crosslinking agent were mixed. Ethyl acetate was added to the mixture so that the total solid content became 25% by mass, and the mixture was uniformly stirred for 10 minutes to obtain a varnish for forming a photocurable pressure-sensitive adhesive layer. While adjusting the gap, the obtained varnish for forming the photocurable pressure-sensitive adhesive layer is applied to a polyethylene terephthalate (PET) film with a width of 350 mm, a length of 400 mm, and a thickness of 38 μm, which has been subjected to a demolding treatment on one side, so that the thickness of the photocurable pressure-sensitive adhesive layer after drying becomes 10 μm, and the varnish for forming the photocurable pressure-sensitive adhesive layer is heated and dried at 80-100°C for 3 minutes. Then, a polyolefin film (substrate layer, thickness: 90 μm) with a corona discharge treatment on one side is bonded, cured at 40°C for 72 hours, and cross-linked to obtain a dicing film having a substrate layer and a photocurable pressure-sensitive adhesive layer. In addition, cross-linking is performed while confirming the progress of curing using FT-IR spectroscopy.

[0179] (Fabrication of Die-bonding Film)

[0180] 55 parts by mass of YDCN-703 (manufactured by Tohto Kasei Co., Ltd., trade name, cresol novolac type epoxy resin, epoxy equivalent 210, molecular weight 1200, softening point 80°C) as an epoxy resin, 45 parts by mass of Milex XLC-LL (manufactured by Mitsui Chemicals, Inc., trade name, hydroxyl equivalent 175, water absorption 1.8%, heating mass reduction rate at 350°C 4%) as a phenolic resin, 1.7 parts by mass of NUCA-189 (manufactured by Nippon Unica Co., Ltd., trade name, γ-mercaptopropyltrimethoxysilane) as a silane coupling agent, 3.2 parts by mass of NUCA-1160 (manufactured by Nippon Unica Co., Ltd., trade name, γ-ureidopropyltriethoxysilane) as a silane coupling agent, and 32 parts by mass of AEROSIL Cyclohexanone was added to R972 (a silica filler whose surface was coated with dimethyldichlorosilane, hydrolyzed in a reactor at 400°C, and surface-modified with an organic group such as methyl, manufactured by NIPPON AEROSIL CO., LTD., trade name, average particle size 0.016 μm), and stirred and mixed, and then kneaded for 90 minutes using a bead mill. 280 parts by mass of HTR-860P-3 (manufactured by Nagase Chemtex Corporation, trade name, weight average molecular weight 800,000, acrylic rubber containing 3% by mass of glycidyl acrylate or glycidyl methacrylate) and 0.5 parts by mass of Curesol 2PZ-CN (manufactured by SHIKOKU CHEMICALS CORPORATION, trade name, 1-cyanoethyl-2-phenylimidazole) as a curing accelerator were added to the obtained mixture, stirred and mixed, and vacuum degassed to obtain a varnish for forming an adhesive layer. The obtained adhesive layer-forming varnish was applied to a release-treated polyethylene terephthalate (PET) film to a predetermined thickness, and dried by heating at 140° C. for 5 minutes to form a 10 μm-thick B-stage adhesive layer, thereby manufacturing a die bonding film having an adhesive layer.

[0181] (Production of Die-cutting and Bonding Integrated Film)

[0182] The die bonding film produced by the above is cut into a size that is easy to handle together with the PET film. For the adhesive layer of the cut die bonding film, the PET film is peeled off and then attached before the photocurable pressure-sensitive adhesive layer of the cut film is attached. The bonding is performed in a clean room (a dust-free room with a temperature of 23°C and a humidity of 50%) using a laminator without a heated roller (i.e., a temperature of 23°C). Afterwards, from the viewpoint of maintaining a constant adhesion between the adhesive layer and the photocurable pressure-sensitive adhesive layer, the cut die bonding integrated film A is obtained by storing it in a refrigerator at 4°C for 1 day.

[0183] <Production Example 2: Preparation of Dicing Die Bonding Integrated Film B>

[0184] A dicing die bonding integrated film B was obtained in the same manner as in Production Example 1 except that the content of the cross-linking agent was changed from 8 parts by mass to 10 parts by mass.

[0185] <Production Example 3: Preparation of Dicing Die Bonding Integrated Film C>

[0186] A dicing die bonding integrated film C was obtained in the same manner as in Production Example 1 except that the (meth)acrylic copolymer solution was changed from A to B and the content of the crosslinking agent was changed from 8 parts by mass to 6 parts by mass.

[0187] <Production Example 4: Preparation of Dicing Die Bonding Integrated Film D>

[0188] A dicing die bonding integrated film D was obtained in the same manner as in Production Example 1 except that the coating speed of the photocurable pressure-sensitive adhesive layer-forming varnish was changed to 0.8 times that of Production Example 1.

[0189] <Production Example 5: Preparation of Dicing Die Bonding Integrated Film E>

[0190] A dicing die bonding integrated film E was obtained in the same manner as in Production Example 1 except that the coating speed of the photocurable pressure-sensitive adhesive layer-forming varnish was changed to 1.2 times that of Production Example 1.

[0191] <Production Example 6: Preparation of Dicing Die Bonding Integrated Film F>

[0192] A dicing die bonding integrated film F was obtained in the same manner as in Production Example 1 except that the (meth)acrylic copolymer solution was changed from A to C and the content of the cross-linking agent was changed from 8 parts by mass to 6 parts by mass.

[0193] <Production Example 7: Preparation of Dicing Die Bonding Integrated Film G>

[0194] A dicing die bonding integrated film G was obtained in the same manner as in Production Example 1 except that the (meth)acrylic copolymer solution was changed from A to D and the content of the cross-linking agent was changed from 8 parts by mass to 6 parts by mass.

[0195] <Production Example 8: Preparation of Dicing Die Bonding Integrated Film H>

[0196] A dicing die bonding integrated film H was obtained in the same manner as in Production Example 1 except that the content of the cross-linking agent was changed from 8 parts by mass to 6 parts by mass.

[0197] <Production Example 9: Preparation of Dicing Die Bonding Integrated Film I>

[0198] A dicing die bonding integrated film I was obtained in the same manner as in Production Example 1 except that the (meth)acrylic acid copolymer solution A was changed to the (meth)acrylic acid copolymer solution E.

[0199] <Production Example 10: Preparation of Dicing Die Bonding Integrated Film J>

[0200] A dicing die bonding integrated film J was obtained in the same manner as in Production Example 1 except that the coating speed of the photocurable pressure-sensitive adhesive layer-forming varnish was changed to 1.5 times that of Production Example 1.

[0201] <Production Example 11: Preparation of Dicing and Die Bonding Integrated Film K>

[0202] A dicing die bonding integrated film K was obtained in the same manner as in Production Example 1 except that the coating speed of the photocurable pressure-sensitive adhesive layer-forming varnish was changed to 0.6 times that of Production Example 1.

[0203] <Production Example 12: Preparation of Dicing Die Bonding Integrated Film L>

[0204] In the preparation of the cutting die bonding integrated film, the PET film of the cutting film is peeled off in a clean room (a dust-free room with a temperature of 23°C and a humidity of 50%), and the photocurable pressure-sensitive adhesive layer is exposed to the air for more than one day and then attached to the adhesive layer of the die bonding film. Other operations are carried out in the same manner as in Manufacturing Example 1 to obtain a cutting die bonding integrated film L.

[0205] <Manufacturing Example 13: Preparation of Dicing Die Bonding Integrated Film M>

[0206] A dicing die bonding integrated film M was obtained in the same manner as in Production Example 1 except that the adhesive layer of the die bonding film and the photocurable pressure-sensitive adhesive layer of the dicing film were bonded together while the roll of the laminator was heated to 50° C. in the preparation of the dicing die bonding integrated film.

[0207] [Determination of peel force]

[0208] <Preparation of measurement samples>

[0209] The diced die bonding integrated films A to M were cut into 30 mm wide and 200 mm long, the PET film on the adhesive layer side of the die bonding film was peeled off, and the support film (EC tape manufactured by Oji Tac Co., Ltd.) was attached to the adhesive layer side using a roller and cut into 25 mm wide and 170 mm long. Next, an ultraviolet irradiation device (UV SYSTEM manufactured by GS YUASA CORPORATION, ultraviolet light with a central wavelength of 365 nm) was used to irradiate the substrate layer (polyolefin film) side of the cut diced die bonding integrated film with an adhesive film at a temperature below 40°C and an irradiation intensity of 70 mW / cm 2 And the cumulative light intensity is 150mJ / cm 2 The photocurable pressure-sensitive adhesive layer is irradiated with light to form a cured product, thereby obtaining a measurement sample.

[0210] <Measurement of peel force>

[0211] For the measurement sample prepared as described above, an angle-free adhesive / film peeling analysis device VPA-2S (manufactured by Kyowa Interface Science Co., Ltd.) was used to stretch the support film at a temperature of 25±5°C, a humidity of 55±10%, a peeling angle of 30°, and a peeling speed of 600mm / min to measure the peeling force (low angle (30°) peeling strength) when peeling the cured product of the adhesive layer and the photocurable pressure-sensitive adhesive layer. The same measurement was performed 3 times, and the average value was used as the low angle peeling strength. The results are shown in Tables 2, 3, and 4. In addition, the sufficiency of condition (a) (peeling force is less than 0.70N / 25mm) is also shown in Tables 2, 3, and 4.

[0212] [Measurement of wire drawing trace count and trace width]

[0213] <Preparation of measurement samples>

[0214] The dicing die bonding integrated film is the same as the film used in the above-mentioned peeling force measurement, and a film that has not been subjected to the above-mentioned peeling force measurement is used. The dicing die bonding integrated films A to M are cut into 30 mm wide and 50 mm long or more, respectively. Next, the heater is brought into contact with the substrate layer (polyolefin film) of the dicing die bonding integrated film, and the photocurable pressure-sensitive adhesive layer is heated at 65°C for 15 minutes, and then air-cooled to 25±5°C. After air-cooling, the PET film on the adhesive layer side of the die bonding film is peeled off, and the support film (manufactured by Oji Tac Co., Ltd., EC tape) is attached and neatly cut into 25 mm in width. Next, an ultraviolet irradiation device (manufactured by GSYUASA CORPORATION, UV SYSTEM, ultraviolet rays with a central wavelength of 365 nm) is used on the substrate layer (polyolefin film) side of the dicing die bonding integrated film with the support film after self-heating and cooling, at an irradiation temperature below 40°C and an irradiation intensity of 70 mW / cm 2 And the cumulative light intensity is 150mJ / cm 2 Then, the adhesive layer and the cured product of the photocurable pressure-sensitive adhesive layer were peeled off by irradiating the cured product of the photocurable pressure-sensitive adhesive layer. Then, the adhesive layer and the cured product of the photocurable pressure-sensitive adhesive layer were peeled off by using an angle-free adhesive / film peeling analysis device VPA-2S (manufactured by Kyowa Interface Science Co., Ltd.), and the support film was stretched at a temperature of 25±5°C, a humidity of 55±10%, a peeling angle of 30°, and a peeling speed of 600 mm / min. The substrate layer of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer was peeled off was recovered, and the sample for measurement was obtained by cutting into a size of 5 mm×5 mm.

[0215] <Measurement of wire drawing mark number and mark width>

[0216] The measurement sample prepared as above is fixed on a plate-shaped stage. Carbon double-sided tape is used to fix the measurement sample. Using a scanning probe microscope (manufactured by Hitachi High-Tech Science Corporation, trade name "SPA400"), the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off is observed, and image analysis software (attached to "SPA400") is used for analysis. A cantilever with a low spring constant (manufactured by Olympus Corporation, trade name "OMCL-AC240TS") is set on the probe of the scanning probe microscope. In the observation of the cured product of the photocurable pressure-sensitive adhesive layer, observation is performed in a dynamic mode (DFM), and phase image data is obtained at the same time, and the part in the phase image where the hardness is obviously different from the surrounding area is used as a drawing mark. In the observation of the measurement sample, it is confirmed whether there is a 25μm×25μm area (specific area) with a number of drawing marks of 15 or more on the surface of the observation object. In the case of a specific area where the number of traces of wire drawing marks on the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off is more than 15, the median of the trace width of the wire drawing marks present in the specific area is calculated. The trace width of the wire drawing marks is obtained as follows. First, a scanning probe microscope is used to obtain the shape image distribution and phase image distribution of the cured product surface of the photocurable pressure-sensitive adhesive layer containing a portion whose hardness is obviously different from the surrounding in the phase image. Then, according to the shape image distribution obtained, a commercially available image processing software (image processing software attached to a scanning probe microscope, etc.) is used to output the cross-sectional distribution of the cross-sectional line of view with the largest trace width of each wire drawing mark for all wire drawing marks that become the object of measurement, and the trace width of the wire drawing marks is obtained according to the above-mentioned benchmark. In addition, in the shape image distribution, the wire drawing marks are represented by the lightest color (in the case of a black and white image, such as white), but the number of portions whose hardness is obviously different from the surrounding in the phase image is the same as the number of portions represented by the lightest color in the shape image distribution. The results are shown in Tables 2, 3 and 4. In addition, the sufficiency of condition (b) (the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off has a 25μm×25μm area with 15 or more wire drawing marks, and the median of the width of the wire drawing marks in the area is 120 to 200nm) is also shown in Tables 2, 3 and 4.

[0217] [Evaluation of Pickup Properties in Cutting Process]

[0218] The obtained dicing die-bonding integrated films A to M of Manufacturing Examples 1 to 13 were evaluated for the success rate of picking up under the predetermined conditions of the dicing process and the peeling time required for picking up.

[0219] <Production of evaluation samples>

[0220] (Formation of Modified Layer)

[0221] A back grinding tape was attached to one side of a semiconductor wafer (silicon wafer (thickness 750 μm, outer diameter 12 inches)) to obtain a semiconductor wafer with a back grinding tape. Laser light was irradiated to the side of the semiconductor wafer opposite to the side to which the back grinding tape was attached to form a modified layer inside the semiconductor wafer. The laser irradiation conditions were as follows.

[0222] Laser oscillator type: semiconductor laser excited Q-switched solid laser

[0223] Wavelength: 1342nm

[0224] Vibration form: Pulse

[0225] Frequency: 90kHz

[0226] Output: 1.7W

[0227] Semiconductor wafer stage moving speed: 700 mm / sec

[0228] Next, the surface of the semiconductor wafer opposite to the side on which the back grinding tape was attached was back ground and polished, thereby obtaining a semiconductor wafer having a thickness of 30 μm.

[0229] (Wafer Lamination)

[0230] On the surface of the semiconductor wafer opposite to the side on which the back grinding tape was attached, the PET film of the dicing die bonding integrated film was peeled off and an adhesive layer was attached.

[0231] (Cutting)

[0232] Next, the semiconductor wafer with the dicing die bonding integrated film having the modified layer is fixed on an expansion device. Next, the dicing film is expanded under the following conditions to separate the semiconductor wafer, the adhesive layer, and the photocurable pressure-sensitive adhesive layer.

[0233] Device: manufactured by DISCO CORPORATION, trade name "DDS 2300 Fully Automatic DieSeparator"

[0234] Cold expansion conditions:

[0235] Temperature: -15°C, Height: 9mm, Cooling time: 90 seconds, Speed: 300mm / second, Standby time: 0 seconds

[0236] Heat shrinkage conditions:

[0237] Temperature: 220°C, Height: 7mm, Holding time: 15 seconds, Speed: 30mm / second, Heating speed: 7°C / second

[0238] (Ultraviolet radiation)

[0239] The photocurable pressure-sensitive adhesive layer of the singulated semiconductor wafer was irradiated with an intensity of 70 mW / cm 2 And the cumulative light intensity is 150mJ / cm 2 The ultraviolet rays having a central wavelength of 365 nm were irradiated to form a cured product of the photocurable pressure-sensitive adhesive layer, thereby obtaining a sample for evaluating pickup properties described below.

[0240] <Evaluation of Pickup Performance>

[0241] A pick-up test was performed using a die bonder DB-830P (manufactured by FASFORD TECHNOLOGY (formerly Hitachi High-technologies)) with 9 pins. The pick-up chuck used was RUBBER TIP 13-087E-33 (manufactured by MICRONICS JAPAN CO., LTD., trade name, size: 10×10 mm). The ejector pin used was EJECTORNEEDLE SEN2-83-05 (manufactured by MICRONICS JAPAN CO., LTD., trade name, diameter: 0.7 mm, tip shape: semicircle with a diameter of 350 μm). Nine ejector pins were arranged at equal intervals from the pin center.

[0242] (Pickup success rate)

[0243] In the above-mentioned pickup test, the pickup success rate of 95% to 100% was evaluated as "A", and the pickup success rate of less than 95% was evaluated as "B". The results are shown in Tables 2, 3, and 4.

[0244] (Pick-up peeling time)

[0245] Use high-speed camera MEMRECM GX-1Plus (manufactured by nac Image Technology Inc., trade name) to shoot the above-mentioned pick-up test, and evaluate the time from the contact between the chuck and the chip to the complete peeling of the adhesive layer and the photocurable pressure-sensitive adhesive layer as the peeling time. Picking is carried out at a speed of 1mm / second up to 300μm. The frame rate is 1000 frames / second. The peeling time is evaluated as "A" when it is less than 60ms, "B" when it is more than 60ms and less than 90ms, and "C" when it is more than 90ms. The results are shown in Table 2, Table 3 and Table 4.

[0246] [Table 2]

[0247]

[0248] [Table 3]

[0249]

[0250] [Table 4]

[0251]

[0252] As shown in Tables 2, 3, and 4, the peeling force of the diced die-bonded integrated films A to E of Manufacturing Examples 1 to 5 is less than 0.70 N / 25 mm, and there is a 25 μm×25 μm area with 15 or more wire drawing marks on the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off, and the median of the width of the wire drawing marks in the area is 120 to 200 nm, which all meet conditions (a) and (b). It is clear that the diced die-bonded integrated films A to E of these Manufacturing Examples 1 to 5 are excellent in the evaluation of pickup properties. In contrast, it is clear that the diced die-bonded integrated films F to M of Manufacturing Examples 6 to 13 that do not meet either condition (a) or condition (b), or do not meet both conditions (a) and conditions (b), are insufficient in the evaluation of pickup properties.

[0253] Explanation of symbols

[0254] 1-cutting die bonding integrated film, 2-protective film, 4-modified layer, 10-base material layer, 20-photocurable pressure-sensitive adhesive layer, 20ac-cured material of the photocurable pressure-sensitive adhesive layer, 30, 30a-adhesive layer, 42-ejector pin, 44-suction chuck, 50-semiconductor element with adhesive layer, 60-support substrate for mounting semiconductor element, 70-bonding wire, 80-resin sealing material, 90-solder ball, W1, W2-semiconductor wafer, H1-thickness of semiconductor wafer W1, H2-thickness of semiconductor wafer W2, 100-semiconductor device.

Claims

1. A method for evaluating a photocurable pressure-sensitive adhesive, wherein the photocurable pressure-sensitive adhesive is used for cutting a die-bonding integrated film, comprising: In the first step, a dicing die bonding integrated film having a substrate layer, a photocurable pressure-sensitive adhesive layer formed of a photocurable pressure-sensitive adhesive, and an adhesive layer laminated in sequence is prepared, the photocurable pressure-sensitive adhesive layer is irradiated with ultraviolet rays under the following irradiation conditions to form a cured product of the photocurable pressure-sensitive adhesive layer, and a peeling force when the adhesive layer and the cured product of the photocurable pressure-sensitive adhesive layer are peeled off under the following peeling conditions is measured; The second step is to prepare a dicing die bonding integrated film having a substrate layer, a photocurable pressure-sensitive adhesive layer formed by a photocurable pressure-sensitive adhesive, and an adhesive layer laminated in sequence, treat the photocurable pressure-sensitive adhesive layer under the following heating and cooling conditions, and irradiate the photocurable pressure-sensitive adhesive layer with ultraviolet rays under the following irradiation conditions to form a cured product of the photocurable pressure-sensitive adhesive layer, peel off the adhesive layer and the cured product of the photocurable pressure-sensitive adhesive layer under the following peeling conditions, observe the surface of the cured product of the photocurable pressure-sensitive adhesive layer after the adhesive layer is peeled off using a scanning probe microscope, and measure the number and width of wire drawing marks on the surface; as well as In the third step, the quality of the photocurable pressure-sensitive adhesive is determined based on whether the peeling force and the number and width of the wire drawing marks satisfy the following conditions (a) and (b). Irradiation conditions Irradiation intensity: 70mW / cm 2 Total light intensity: 150mJ / cm 2 Stripping conditions Temperature: 25±5℃ Humidity: 55±10% Peeling angle: 30° Peeling speed: 600mm / min Heating and cooling conditions Heat treatment: 65°C, 15 minutes Cooling treatment: Leave in air for 30 minutes until the temperature reaches 25±5℃ Condition (a): The peeling force is 0.70 N / 25 mm or less, Condition (b): After the adhesive layer is peeled off, there is a 25 μm×25 μm area with 15 or more wire drawing marks on the surface of the cured product of the photocurable pressure-sensitive adhesive layer, and the median of the wire drawing marks in the area is 120 to 200 nm.

2. The method for evaluating a photocurable pressure-sensitive adhesive according to claim 1, wherein: The photocurable pressure-sensitive adhesive contains a (meth)acrylic copolymer having a reactive functional group, a photopolymerization initiator, and a crosslinking agent having two or more functional groups capable of reacting with the reactive functional group.

3. The method for evaluating a photocurable pressure-sensitive adhesive according to claim 2, wherein: The (meth)acrylic copolymer contains (meth)acrylic acid as a monomer unit.

4. The method for evaluating a photocurable pressure-sensitive adhesive according to any one of claims 1 to 3, wherein: The adhesive layer contains an epoxy resin, an epoxy resin curing agent, and a (meth)acrylic copolymer having an epoxy group.

5. A method for manufacturing a dicing die bonding integrated film, comprising: A step of forming a photocurable pressure-sensitive adhesive layer formed of a photocurable pressure-sensitive adhesive judged to be good by the photocurable pressure-sensitive adhesive evaluation method according to any one of claims 1 to 4 on a substrate layer; and A step of forming an adhesive layer on the photocurable pressure-sensitive adhesive layer.

6. A method for manufacturing a semiconductor device, comprising: a step of attaching the adhesive layer of the dicing die bonding integrated film obtained by the method for manufacturing a dicing die bonding integrated film according to claim 5 to a semiconductor wafer; A step of singulating the semiconductor wafer, the adhesive layer, and the photocurable pressure-sensitive adhesive layer by dicing; The step of irradiating the photocurable pressure-sensitive adhesive layer with ultraviolet rays to form a cured product of the photocurable pressure-sensitive adhesive layer; A step of picking up the semiconductor element to which the adhesive layer is attached from the cured product of the photocurable pressure-sensitive adhesive layer; and A step of bonding the semiconductor element to a supporting substrate for mounting a semiconductor element via the adhesive layer.

7. The method for manufacturing a semiconductor device according to claim 6, wherein: The thickness of the semiconductor wafer is less than 35 μm.

8. The method for manufacturing a semiconductor device according to claim 6 or 7, wherein: The cutting adopts invisible cutting. 9 . A dicing die bonding integrated film comprising, in order, a base layer, a photocurable pressure-sensitive adhesive layer formed of a photocurable pressure-sensitive adhesive judged to be good by the photocurable pressure-sensitive adhesive evaluation method according to claim 1 , and an adhesive layer.

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