Adhesive film and method for manufacturing electronic device

Abstract

The adhesive film (50) of the present invention is an adhesive film used for temporarily fixing the electronic component when the electronic component is sealed by a sealing material in the manufacturing process of the electronic device, and comprises: an adhesive resin layer (A) for temporarily fixing the electronic component, an adhesive resin layer (B) for being attached to a supporting substrate and having its adhesive force reduced by external stimulation, and an intermediate layer (C) provided between the adhesive resin layer (A) and the adhesive resin layer (B), wherein the storage elastic modulus E' of the intermediate layer (C) at 120°C is 1.0×10 5 Pa above 8.0×10 6 Pa or less, and the loss tangent (tan δ) of the intermediate layer (C) at 120°C is 0.1 or less.

Description

Technical Field

[0001] The present invention relates to an adhesive film and a method for manufacturing an electronic device. Background Art

[0002] As a technology capable of achieving miniaturization and weight reduction of electronic devices (for example, semiconductor devices), fan-out WLP (wafer level packaging) has been developed.

[0003] In eWLB (Embedded Wafer Level Ball Grid Array), which is one of the methods for manufacturing fan-out WLP, the following method is adopted: multiple electronic components such as semiconductor chips are temporarily fixed in a separated state on an adhesive film attached to a supporting substrate, and the multiple electronic components are sealed together with a sealing material. Here, the adhesive film needs to be firmly adhered to the electronic component and the supporting substrate during the sealing process, etc., and needs to be removed from the sealed electronic component together with the supporting substrate after sealing.

[0004] As a technique related to a method for manufacturing such a fan-out WLP, for example, there is the technique described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2011-134811).

[0005] Patent document 1 describes a heat-resistant adhesive sheet for manufacturing semiconductor devices, which is characterized in that it is a heat-resistant adhesive sheet for manufacturing semiconductor devices used for adhering when resin-sealing a substrate-less semiconductor chip. The heat-resistant adhesive sheet has a base material layer and an adhesive layer. The adhesive layer has an adhesion to SUS304 of more than 0.5N / 20mm after bonding, and is cured by the stimulation received until the end of the resin sealing process, so that the peeling force for the package becomes less than 2.0N / 20mm.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2011-134811 Summary of the invention

[0009] Problems to be solved by the invention

[0010] According to the research conducted by the inventors, it has been clarified that when electronic components are arranged on an adhesive film adhered to a supporting substrate, the electronic components are sealed with a sealing material, and then the adhesive film is peeled off from the supporting substrate, sometimes a portion of the adhesive resin layer of the adhesive film (hereinafter also referred to as paste) will remain on the supporting substrate side (hereinafter also referred to as paste residue).

[0011] The present invention has been made in view of the above circumstances, and provides an adhesive film for temporarily fixing an electronic component capable of suppressing the paste residue on the supporting substrate side when the adhesive film is peeled off from the supporting substrate.

[0012] Methods for solving problems

[0013] The inventors of the present invention have repeatedly conducted in-depth research to achieve the above-mentioned problems. As a result, it was found that by providing an intermediate layer (C) having a specific elastic modulus and loss tangent (tanδ) between an adhesive resin layer (A) for temporarily fixing electronic components and an adhesive resin layer (B) whose adhesive force is reduced by external stimulation, it is possible to suppress the paste residue on the supporting substrate side when the adhesive film is peeled off from the supporting substrate, thereby completing the present invention.

[0014] According to the present invention, there are provided the following adhesive film and method for producing an electronic device. [1]

[0016] An adhesive film is used to temporarily fix an electronic component when the electronic component is sealed by a sealing material in a manufacturing process of an electronic device, and comprises:

[0017] An adhesive resin layer (A) for temporarily fixing the electronic component;

[0018] An adhesive resin layer (B) for attaching to a supporting substrate and having adhesive strength reduced by external stimulation; and

[0019] an intermediate layer (C) provided between the adhesive resin layer (A) and the adhesive resin layer (B),

[0020] The storage elastic modulus E' of the intermediate layer (C) at 120°C is 1.0×10 5 Pa above 8.0×10 6 Pa or less, and the loss tangent (tan δ) of the intermediate layer (C) at 120°C is 0.1 or less. [2]

[0022] The adhesive film according to the above-mentioned [1],

[0023] The adhesive strength of the adhesive resin layer (B) is reduced by heating. [3]

[0025] According to the adhesive film described in [2] above,

[0026] The adhesive resin layer (B) contains at least one selected from the group consisting of a gas generating component and heat-expandable microspheres. [4]

[0028] The adhesive film according to any one of [1] to [3] above,

[0029] When the entirety of the adhesive resin layer (A) is taken as 100 mass %, the content of at least one selected from the group consisting of a gas generating component and heat-expandable microspheres in the adhesive resin layer (A) is 0.1 mass % or less. [5]

[0031] The adhesive film according to any one of [1] to [4] above,

[0032] The sealing material is an epoxy resin-based sealing material. [6]

[0034] The adhesive film according to any one of [1] to [5] above,

[0035] The adhesive resin layer (A) contains a (meth)acrylic adhesive resin. [7]

[0037] A method for manufacturing an electronic device, comprising at least the following steps:

[0038] Step (1), preparing a structure comprising: the adhesive film according to any one of the above [1] to [6], an electronic component attached to the adhesive resin layer (A) of the adhesive film, and a supporting substrate attached to the adhesive resin layer (B) of the adhesive film;

[0039] Step (2), sealing the electronic component with a sealing material;

[0040] Step (3), applying an external stimulus to reduce the adhesive force of the adhesive resin layer (B), thereby peeling the supporting substrate from the structure; and

[0041] Step (4) of peeling the adhesive film from the electronic component. [8]

[0043] According to the method for manufacturing an electronic device described in [7] above, the sealing material is an epoxy resin-based sealing material.

[0044] Effects of the Invention

[0045] According to the present invention, it is possible to provide an adhesive film for temporarily fixing an electronic component which can suppress the paste residue on the supporting substrate side when the adhesive film is peeled off from the supporting substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The above-mentioned object and other objects, features and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings.

[0047] Figure 1 This is a cross-sectional view schematically showing an example of the structure of the adhesive film according to the embodiment of the present invention.

[0048] Figure 2 This is a cross-sectional view schematically showing an example of the structure of the adhesive film according to the embodiment of the present invention.

[0049] Figure 3 It is a cross-sectional view schematically showing an example of a method for manufacturing an electronic device according to an embodiment of the present invention.

[0050] Figure 4 It is a cross-sectional view schematically showing an example of a method for manufacturing an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] Hereinafter, the embodiments of the present invention will be described using the accompanying drawings. In addition, in all the drawings, the same components are given common symbols and the description is appropriately omitted. In addition, the drawings are schematic diagrams and are inconsistent with the actual dimensional ratios. In addition, the numerical range "A to B" means above A and below B unless otherwise specified. In addition, in the present embodiment, the so-called "(meth) acrylic acid" refers to acrylic acid, methacrylic acid, or both acrylic acid and methacrylic acid.

[0052] 1. Adhesive film for temporary fixing of electronic components

[0053] Hereinafter, the adhesive film 50 according to the present embodiment will be described.

[0054] Figure 1 and Figure 2 It is a cross-sectional view schematically showing an example of the structure of the adhesive film 50 according to the embodiment of the present invention.

[0055] like Figure 1 As shown in FIG. 1 , the adhesive film 50 of the present embodiment is an adhesive film used to temporarily fix the electronic components when the electronic components are sealed by a sealing material in the manufacturing process of the electronic device, and comprises: an adhesive resin layer (A) for temporarily fixing the electronic components, an adhesive resin layer (B) for being attached to a supporting substrate and having its adhesive force reduced by external stimulation, and an intermediate layer (C) provided between the adhesive resin layer (A) and the adhesive resin layer (B). Moreover, the storage elastic modulus E' of the intermediate layer (C) at 120°C is 1.0×10 5 Pa above 8.0×10 6 Pa or less, and the loss tangent (tan δ) of the intermediate layer (C) at 120°C is 0.1 or less.

[0056] As described above, the inventors have found that when electronic components are arranged on an adhesive film attached to a support substrate, the electronic components are sealed with a sealant, and then the adhesive film is peeled from the support substrate, paste residue may be generated on the support substrate side.

[0057] The reason is not clear, but it is believed to be the following. First, when the electronic component is sealed by the sealing material, the metal frame (the peripheral portion of the mold) contacts the adhesive film, and stress is applied to the adhesive film and the supporting substrate at the contact position. It is believed that at the position where the stress is applied, the adhesion between the supporting substrate and the adhesive resin layer is improved, and when the adhesive film is peeled off from the supporting substrate, a part of the adhesive resin layer of the adhesive film will remain on the supporting substrate side.

[0058] The present inventors have repeatedly conducted in-depth research to realize an adhesive film for temporarily fixing electronic components that can suppress the paste residue generated on the supporting substrate side when the electronic components are sealed by a sealing material in the manufacturing process of an electronic device. As a result, the following understanding was obtained: in an adhesive film having an adhesive resin layer (A) for temporarily fixing electronic components and an adhesive resin layer (B) whose adhesive force is reduced by external stimulation, it is effective to provide an intermediate layer (C) having a specific elastic modulus and loss tangent (tanδ) between the adhesive resin layer (A) and the adhesive resin layer (B).

[0059] Furthermore, the present inventors conducted further studies based on the above findings and found for the first time that by setting the storage elastic modulus E' and loss tangent (tanδ) of the intermediate layer (C) at 120°C to the above ranges, it is possible to effectively suppress the paste residue on the supporting substrate side when the adhesive film is peeled off from the supporting substrate.

[0060] That is, the adhesive film 50 involved in this embodiment is provided with an intermediate layer (C) between the adhesive resin layer (A) and the adhesive resin layer (B), so that the storage elastic modulus E' and the loss tangent (tanδ) of the intermediate layer (C) at 120°C are within the above-mentioned range, thereby being able to effectively suppress the paste residue on the supporting substrate side when the adhesive film is peeled off from the supporting substrate.

[0061] The reason why the adhesive film 50 according to the present embodiment can effectively suppress the paste residue on the supporting substrate side when the adhesive film is peeled off from the supporting substrate is not clear, but is considered to be the following reason.

[0062] First, as described above, when the electronic component is sealed by the sealing material, the metal frame (the outer periphery of the mold) contacts the adhesive film, and stress is applied to the adhesive film and the supporting substrate at the contact portion. It is believed that the adhesion between the supporting substrate and the adhesive resin layer is increased at the portion where the stress is applied, and when the adhesive film is peeled off from the supporting substrate, a part of the adhesive resin layer of the adhesive film will remain on the supporting substrate side.

[0063] On the other hand, the adhesive film 50 according to the present embodiment is provided with an intermediate layer (C) having a storage elastic modulus E' and a loss tangent (tanδ) within the above range at 120°C between the adhesive resin layer (A) and the adhesive resin layer (B). It is believed that the stress from the metal frame is relieved by the intermediate layer (C), and the increase in the adhesive force between the support substrate and the adhesive resin layer can be suppressed, and as a result, the paste residue on the support substrate side when the adhesive film is peeled off from the support substrate can be effectively suppressed.

[0064] The entire thickness of the adhesive film 50 according to the present embodiment is preferably from 10 μm to 1000 μm, and more preferably from 20 μm to 500 μm, from the viewpoint of the balance between mechanical properties and handling properties.

[0065] The adhesive film 50 according to the present embodiment can be used as a film for temporarily fixing electronic components in the manufacturing process of electronic devices, and can be particularly suitably used as a film for temporarily fixing electronic components in the manufacturing process of fan-out WLP and fan-out PLP.

[0066] Next, each layer constituting the adhesive film 50 according to the present embodiment will be described.

[0067] <Adhesive resin layer (A)>

[0068] The adhesive resin layer (A) is a layer that comes into contact with the surface of an electronic component to temporarily fix the electronic component when the electronic component is sealed with a sealing material in the production process of an electronic device.

[0069] The adhesive resin layer (A) contains an adhesive resin.

[0070] Examples of the adhesive resin include (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins.

[0071] Among these, from the viewpoint of facilitating the adjustment of adhesive strength, a (meth)acrylic adhesive resin is preferred.

[0072] As the adhesive resin layer (A), a radiation cross-linked adhesive resin layer whose adhesive force is reduced by radiation can also be used. The radiation cross-linked adhesive resin layer is cross-linked by irradiation with radiation, and the adhesive force is significantly reduced, so it becomes easy to peel the adhesive film 50 from the electronic component. As radiation, ultraviolet rays, electron beams, infrared rays, etc. can be cited.

[0073] As the radiation cross-linkable adhesive resin layer, an ultraviolet cross-linkable adhesive resin layer is preferable.

[0074] Examples of the (meth)acrylic adhesive resin used for the adhesive resin layer (A) include copolymers containing (meth)acrylic acid alkyl ester monomer units (A) and monomer units (B) having a functional group reactive with a crosslinking agent.

[0075] In the present embodiment, the (meth)acrylic acid alkyl ester refers to an acrylate alkyl ester, a methacrylate alkyl ester, or a mixture thereof.

[0076] The (meth)acrylic adhesive resin according to the present embodiment can be obtained, for example, by copolymerizing a monomer mixture containing an alkyl (meth)acrylate monomer (A) and a monomer (B) having a functional group reactive with a crosslinking agent.

[0077] As the monomer (A) forming the (meth)acrylic acid alkyl ester monomer unit (A), there can be mentioned an (meth)acrylic acid alkyl ester having an alkyl group with about 1 to 12 carbon atoms. It is preferably an (meth)acrylic acid alkyl ester having an alkyl group with 1 to 8 carbon atoms. Specifically, there can be mentioned methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, etc. These can be used alone or in combination of two or more.

[0078] In the (meth)acrylic adhesive resin involved in the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin is set to 100 mass%, the content of the (meth)acrylic acid alkyl ester monomer unit (A) is preferably 10 mass% to 98.9 mass%, and more preferably 85 mass% to 95 mass%.

[0079] As the monomer (B) for forming the monomer (B) having a functional group capable of reacting with the crosslinking agent, acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, itaconic acid monoalkyl esters, mesaconic acid monoalkyl esters, citraconic acid monoalkyl esters, fumaric acid monoalkyl esters, maleic acid monoalkyl esters, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tert-butylaminoethyl acrylate, tert-butylaminoethyl methacrylate, etc. are mentioned. Preferred are acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, etc. These can be used alone or in combination of two or more.

[0080] In the (meth)acrylic adhesive resin involved in the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin is set to 100 mass%, the content of the monomer unit (B) is preferably 1 mass% to 40 mass%, more preferably 1 mass% to 20 mass%, and further preferably 1 mass% to 10 mass%.

[0081] The (meth)acrylic adhesive resin according to the present embodiment may further contain a bifunctional monomer (C) or a specific comonomer (hereinafter referred to as a polymerizable surfactant) unit having a property as a surfactant, in addition to the monomer unit (A) and the monomer unit (B).

[0082] The polymerizable surfactant has a property of copolymerizing with the monomer (A), the monomer (B) and the monomer (C), and has a function as an emulsifier in the case of emulsion polymerization.

[0083] Examples of the monomer (C) forming the bifunctional monomer unit (C) include allyl methacrylate, allyl acrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tetraethylene glycol di(meth)acrylate, and monomers having diacrylate or dimethacrylate at both ends and a propylene glycol type main chain structure (e.g., manufactured by NOF Corporation, commercially available Product name: PDP-200, PDP-400 manufactured by NOF Corporation, ADP-200 manufactured by NOF Corporation, ADP-400 manufactured by NOF Corporation), 1,4-butanediol type (for example, manufactured by NOF Corporation, trade name: ADT-250, manufactured by NOF Corporation ADT-850) and mixed types thereof (for example, manufactured by NOF Corporation, trade name: ADET-1800, manufactured by NOF Corporation ADPT-4000) and the like.

[0084] In the (meth)acrylic adhesive resin involved in this embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin is set to 100 mass%, the content of the monomer unit (C) is preferably 0.1 mass% to 30 mass%, and more preferably 0.1 mass% to 5 mass%.

[0085] Examples of the polymerizable surfactant include surfactants having a polymerizable 1-propenyl group introduced into the benzene ring of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: Aklon RN-10, Aklon RN-20, Aklon RN-30, Aklon RN-50, etc.), surfactants having a polymerizable 1-propenyl group introduced into the benzene ring of ammonium salts of sulfate esters of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: Aklon HS-10, Aklon HS-20, Aklon HS-1025, etc.), and sulfosuccinic acid diesters having a polymerizable double bond in the molecule (manufactured by Kao Corporation; trade names: Latemul S-120A, Latemul S-180A, etc.).

[0086] Furthermore, the (meth)acrylic adhesive resin according to the present embodiment may further contain a monomer unit formed from a monomer having a polymerizable double bond, such as vinyl acetate, acrylonitrile, or styrene, as necessary.

[0087] The polymerization reaction mechanism of the (meth)acrylic adhesive resin of the present embodiment includes free radical polymerization, anionic polymerization, cationic polymerization, etc. If the manufacturing cost of the (meth)acrylic adhesive resin, the influence of the functional groups of the monomers, and the influence of ions on the surface of the electronic components are taken into consideration, it is preferred to polymerize by free radical polymerization.

[0088] When the polymerization is carried out by a radical polymerization reaction, examples of the radical polymerization initiator include organic peroxides such as benzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, 3,3,5-trimethylhexanoyl peroxide, di-2-ethylhexyl peroxydicarbonate, methyl ethyl ketone peroxide, tert-butyl peroxyphthalate, tert-butyl peroxybenzoate, di-tert-butyl peroxyacetate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-2-hexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, tert-butyl peroxide, and di-tert-amyl peroxide; inorganic peroxides such as ammonium persulfate, potassium persulfate, and sodium persulfate; and azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, and 4,4'-azobis-4-cyanovaleric acid.

[0089] When polymerization is performed by emulsion polymerization, among these free radical polymerization initiators, water-soluble inorganic peroxides such as ammonium persulfate, potassium persulfate, and sodium persulfate are preferred, and water-soluble azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid are also preferred. Considering the influence of ions on the surface of electronic components, azo compounds having a carboxyl group in the molecule such as ammonium persulfate and 4,4'-azobis-4-cyanovaleric acid are more preferred, and azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid are particularly preferred.

[0090] The adhesive resin layer (A) according to the present embodiment preferably further contains a crosslinking agent having two or more crosslinkable functional groups in one molecule in addition to the (meth)acrylic adhesive resin.

[0091] The crosslinking agent having two or more crosslinkable functional groups in one molecule is used to react with the functional groups of the (meth)acrylic adhesive resin to adjust the adhesive force and cohesive force.

[0092] Examples of such crosslinking agents include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcinol diglycidyl ether; isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate tris-adduct of trimethylolpropane, polyisocyanates, diphenylmethane diisocyanate, and toluene diisocyanate; trimethylolpropane-tri-β-aziridinyl propionate, tetramethylolmethane-tri-β-aziridinyl propionate, and tetramethylolmethane-tri-β-aziridinyl propionate. Aziridine compounds such as N-aziridinyl propionate, N,N'-diphenylmethane-4,4'-bis(1-aziridine carboxamide), N,N'-hexamethylene-1,6-bis(1-aziridine carboxamide), N,N'-toluene-2,4-bis(1-aziridine carboxamide), and trimethylolpropane-tri-β-(2-methylaziridine) propionate; tetrafunctional epoxy compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; melamine compounds such as hexamethoxymethylolmelamine, etc. These compounds may be used alone or in combination of two or more.

[0093] Among these, it is preferred that one or two or more selected from epoxy compounds (including the above-mentioned tetrafunctional epoxy compounds), isocyanate compounds and aziridine compounds are contained.

[0094] The content of the crosslinking agent is usually preferably within a range where the number of functional groups in the crosslinking agent does not exceed the number of functional groups in the (meth)acrylic adhesive resin. However, in the case where new functional groups are generated by the crosslinking reaction or the crosslinking reaction is slow, an excess amount may be contained as required.

[0095] The content of the cross-linking agent in the adhesive resin layer (A) is preferably from 0.1 to 30 parts by mass, more preferably from 0.1 to 20 parts by mass, and even more preferably from 0.1 to 15 parts by mass, relative to 100 parts by mass of the (meth)acrylic adhesive resin, from the viewpoint of improving the heat resistance of the adhesive resin layer (A) and the balance with the adhesion.

[0096] The thickness of the adhesive resin layer (A) is not particularly limited, but is, for example, preferably from 1 μm to 100 μm, and more preferably from 3 μm to 50 μm.

[0097] The adhesive resin layer (A) can be formed, for example, by coating an adhesive on the intermediate layer (C) or the base layer 10 described later. The adhesive may be dissolved in a solvent and applied as a coating liquid, may be applied as an aqueous emulsion, or may be directly applied as a liquid adhesive.

[0098] Examples of the aqueous emulsion coating liquid include a coating liquid prepared by dispersing a (meth)acrylic adhesive resin (a), a silicone adhesive resin, a urethane adhesive resin, an olefin adhesive resin, a styrene adhesive resin, or the like in water.

[0099] An adhesive coating liquid dissolved in an organic solvent can be used. The organic solvent is not particularly limited, and can be appropriately selected from known organic solvents based on solubility and drying time. Examples of organic solvents include esters such as ethyl acetate and methyl acetate; ketones such as acetone and MEK; aromatics such as benzene, toluene, and ethylbenzene; linear or cyclic aliphatic systems such as heptane, hexane, and cyclohexane; and alcohols such as isopropanol and butanol. Ethyl acetate and toluene are preferred organic solvents. These solvents may be used alone or in combination of two or more.

[0100] As a method for applying the adhesive coating liquid, a conventionally known coating method can be used, for example, a roller coating method, a reverse roller coating method, a gravure roller method, a rod coating method, a notch wheel coating method, a die coating method, etc. The drying conditions of the coated adhesive are not particularly limited. Generally speaking, it is preferably dried for 10 seconds to 10 minutes at a temperature range of 80 to 200° C. It is further preferably dried for 15 seconds to 5 minutes at 80 to 170° C. In order to fully promote the crosslinking reaction of the crosslinking agent and the adhesive, the adhesive coating liquid can be heated at 40 to 80° C. for about 5 to 300 hours after the drying of the adhesive coating liquid is completed.

[0101] The intermediate layer (C) or substrate layer 10 and the adhesive resin layer (A) may be formed by co-extrusion molding, or by laminating (stacking) a film-like intermediate layer (C) or substrate layer 10 and a film-like adhesive resin layer (A).

[0102] <Adhesive resin layer (B)>

[0103] The adhesive film 50 according to the present embodiment includes an adhesive resin layer (B) for being attached to a supporting substrate and having adhesive strength reduced by external stimulation.

[0104] Thus, by applying an external stimulus, the adhesive film 50 can be easily peeled from the supporting substrate.

[0105] Here, as the adhesive resin layer (B) whose adhesive force is reduced by external stimulation, for example, a heat-peelable adhesive resin layer whose adhesive force is reduced by heating, a radiation-peelable adhesive resin layer whose adhesive force is reduced by radiation, etc. Among these, a heat-peelable adhesive resin layer whose adhesive force is reduced by heating is preferred.

[0106] As the heat-peelable adhesive resin layer, for example, there can be mentioned an adhesive resin layer composed of a heat-expandable adhesive containing a gas-generating component, a heat-expandable adhesive containing heat-expandable microspheres that expand and can reduce adhesive strength, a heat-expandable adhesive in which the adhesive component undergoes a cross-linking reaction with the help of heat to reduce adhesive strength, and the like.

[0107] In this embodiment, the heat-expandable adhesive used for the adhesive resin layer (B) is an adhesive whose adhesive strength is reduced or lost by applying heat. For example, a material that does not peel off at a temperature below 150°C and peels off at a temperature exceeding 150°C can be selected, preferably having an adhesive strength to the extent that the adhesive film 50 does not peel off from the supporting substrate during the manufacturing process of the electronic device.

[0108] As the gas generating component used for the heat-expandable adhesive, for example, an azo compound, an azide compound, a McLennan acid derivative, etc. can be used. In addition, inorganic foaming agents such as ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium borohydroxide, various azides, and the like, water; chlorofluoroalkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate; hydrazine compounds such as p-toluenesulfonylhydrazine, diphenylsulfone-3,3'-disulfonylhydrazine, 4,4'-oxybis(benzenesulfonylhydrazine), and allylbis(sulfonylhydrazine); semicarbazide compounds such as p-tolylenesulfonylsemicarbazide and 4,4'-oxybis(benzenesulfonylsemicarbazide); triazole compounds such as 5-morpholino-1,2,3,4-thiatriazole; organic foaming agents such as N-nitroso compounds such as N,N'-dinitrosopentamethylenetetramine and N,N'-dimethyl-N,N'-dinitrosoterephthalamide, and the like; The gas generating component may be added to the adhesive resin or may be directly bonded to the adhesive resin.

[0109] As the heat-expandable microspheres used in the heat-expandable adhesive, for example, a microencapsulated foaming agent can be used. As such heat-expandable microspheres, for example, isobutane, propane, pentane, etc. can be encapsulated in a microsphere in an elastic shell by heating and easily gasifying and expanding substances. As the material constituting the above-mentioned shell, for example, 1,1-dichloroethylene-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, polysulfone, etc. can be cited. Heat-expandable microspheres, for example, can be manufactured by a coagulation method, an interfacial polymerization method, etc.

[0110] Heat-expandable microspheres can be added to the adhesive resin.

[0111] The content of at least one selected from the group consisting of the gas generating component and the heat-expandable microspheres can be appropriately set according to the expansion ratio of the heat-peelable adhesive resin layer (B), the reduction of the adhesive force, etc., and is not particularly limited. For example, it is, for example, 1 mass part to 150 mass parts, preferably 5 mass parts to 130 mass parts, and further preferably 10 mass parts to 100 mass parts, relative to 100 mass parts of the adhesive resin in the heat-peelable adhesive resin layer (B).

[0112] It is preferable to design so that the temperature at which the gas is generated and the temperature at which the heat-expandable microspheres thermally expand become a temperature exceeding 150°C.

[0113] As the adhesive resin constituting the heat-expandable adhesive, for example, (meth) acrylic resin, urethane resin, silicone resin, polyolefin resin, polyester resin, polyamide resin, fluorine resin, styrene-diene block copolymer resin, etc. can be mentioned. Among these, (meth) acrylic resin is preferred.

[0114] As the (meth)acrylic resin used for the adhesive resin layer (B), for example, the same resin as the (meth)acrylic adhesive resin used for the above-mentioned adhesive resin layer (A) can be used.

[0115] In addition, in the adhesive film 50 involved in the present embodiment, from the viewpoint of reducing the adhesive force of the adhesive resin layer (B) by applying external stimulation and stably maintaining the electronic components on the adhesive resin layer (A) when the supporting substrate is peeled off from the adhesive resin layer (B), when the entire adhesive resin layer (A) is set to 100 mass%, the content of at least one selected from gas generating components and heat-expandable microspheres in the adhesive resin layer (A) is preferably 0.1 mass% or less, more preferably 0.05 mass% or less, further preferably 0.01 mass% or less, and particularly preferably not containing at least one selected from gas generating components and heat-expandable microspheres in the adhesive resin layer (A).

[0116] The thickness of the adhesive resin layer (B) is not particularly limited, but is, for example, preferably from 5 μm to 300 μm, and more preferably from 10 μm to 150 μm.

[0117] The adhesive resin layer (B) can be formed, for example, by applying an adhesive coating liquid on the intermediate layer (C) or the base layer 10 described later.

[0118] As a method for applying the adhesive coating liquid, a conventionally known coating method can be used, for example, a roller coating method, a reverse roller coating method, a gravure roller method, a rod coating method, a notch wheel coating method, a die coating method, etc. The drying conditions of the coated adhesive are not particularly limited. Generally speaking, it is preferably dried for 10 seconds to 10 minutes at a temperature range of 80 to 200° C. It is further preferably dried for 15 seconds to 5 minutes at 80 to 170° C. In order to fully promote the crosslinking reaction of the crosslinking agent and the adhesive, the adhesive coating liquid can be heated at 40 to 80° C. for about 5 to 300 hours after the drying of the adhesive coating liquid is completed.

[0119] In addition, the intermediate layer (C) or the base layer 10 and the adhesive resin layer (B) may be formed by co-extrusion molding, or by laminating (stacking) the film-like intermediate layer (C) or the base layer 10 and the film-like adhesive resin layer (B).

[0120] <Middle layer (C)>

[0121] The adhesive film 50 involved in this embodiment has an intermediate layer (C) having a specific elastic modulus and loss tangent (tan δ) between the adhesive resin layer (A) and the adhesive resin layer (B). As a result, the stress absorption of the adhesive film 50 as a whole is improved, and the stress from the metal frame when the electronic component is sealed by the sealing material can be alleviated, and as a result, the increase in the adhesive force between the support substrate and the adhesive resin layer (B) can be suppressed, and as a result, the paste residue on the support substrate side when the adhesive film 50 is peeled off from the support substrate can be effectively suppressed.

[0122] In the adhesive film 50 according to the present embodiment, from the viewpoint of effectively suppressing the paste residue on the supporting substrate side when the adhesive film 50 is peeled off from the supporting substrate, the storage elastic modulus E' of the intermediate layer (C) at 120°C is 1.0×10 5 Pa or more, preferably 1.5×10 5 Pa or more, and 8.0×10 6 Pa or less, preferably 5.0×10 6 Pa or less, more preferably 3.0×10 6 Below Pa.

[0123] The storage elastic modulus E' of the intermediate layer (C) at 120°C can be controlled within the above range by controlling the types and blending ratios of the components constituting the intermediate layer (C), for example.

[0124] In addition, in the adhesive film 50 according to the present embodiment, from the viewpoint of effectively suppressing the paste residue on the supporting substrate side when the adhesive film is peeled off from the supporting substrate, the loss tangent (tan δ) at 120° C. is 0.1 or less. The lower limit of the loss tangent (tan δ) at 120° C. is not particularly limited, and is, for example, 0.0001 or more, preferably 0.001 or more, and more preferably 0.01 or more.

[0125] The loss tangent (tan δ) of the intermediate layer (C) at 120° C. can be controlled within the above range by controlling the types and blending ratios of the components constituting the intermediate layer (C), for example.

[0126] The resin constituting the intermediate layer (C) is not particularly limited as long as the storage elastic modulus E' at 120°C is within the above range, and for example, a thermoplastic resin can be used.

[0127] More specifically, (meth)acrylic resins, urethane resins, silicone resins, polyolefin resins, polyester resins, polyamide resins, fluorine resins, styrene-diene block copolymer resins, and the like are exemplified.

[0128] Among these, (meth)acrylic resins are preferred because the storage elastic modulus E' at 120°C can be easily adjusted.

[0129] The resin constituting the intermediate layer (C) may be used alone or in combination of two or more.

[0130] As the (meth)acrylic resin used for the intermediate layer (C), for example, the same resin as the (meth)acrylic adhesive resin used for the above-mentioned adhesive resin layer (A) can be used.

[0131] When a (meth)acrylic resin is used for the intermediate layer (C) according to the present embodiment, it is preferred that a crosslinking agent having two or more crosslinkable functional groups be further contained in addition to the (meth)acrylic resin.

[0132] The crosslinking agent having two or more crosslinkable functional groups in one molecule is used to react with the functional groups of the (meth)acrylic resin to adjust the adhesive force and the cohesive force.

[0133] Examples of such crosslinking agents include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcinol diglycidyl ether; isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate tris-adduct of trimethylolpropane, polyisocyanates, diphenylmethane diisocyanate, and toluene diisocyanate; trimethylolpropane-tri-β-aziridinyl propionate, tetramethylolmethane-tri-β-aziridinyl propionate, and tetramethylolmethane-tri-β-aziridinyl propionate. Aziridine compounds such as N-aziridinyl propionate, N,N'-diphenylmethane-4,4'-bis(1-aziridine carboxamide), N,N'-hexamethylene-1,6-bis(1-aziridine carboxamide), N,N'-toluene-2,4-bis(1-aziridine carboxamide), and trimethylolpropane-tri-β-(2-methylaziridine) propionate; tetrafunctional epoxy compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; melamine compounds such as hexamethoxymethylolmelamine, etc. These compounds may be used alone or in combination of two or more.

[0134] Among these, it is preferred that one or two or more selected from epoxy compounds, isocyanate compounds and aziridine compounds are contained.

[0135] The content of the crosslinking agent in the intermediate layer (C) is preferably from 0.5 to 10 parts by mass, more preferably from 0.7 to 5 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin, from the viewpoint of adjusting the storage elastic modulus E' at 120°C and the loss tangent (tanδ) at 120°C of the intermediate layer (C) to desired values.

[0136] In addition, in the adhesive film 50 involved in the present embodiment, from the viewpoint of reducing the adhesion of the adhesive resin layer (B) by applying external stimulation and maintaining good adhesion between the intermediate layer (C) and the adhesive resin layer (B) when the supporting substrate is peeled off from the adhesive resin layer (B), when the entire intermediate layer (C) is set to 100 mass%, the content of at least one selected from gas generating components and heat-expandable microspheres in the intermediate layer (C) is preferably less than 0.1 mass%, more preferably less than 0.05 mass%, further preferably less than 0.01 mass%, and particularly preferably not containing at least one selected from gas generating components and heat-expandable microspheres in the intermediate layer (C).

[0137] The thickness of the intermediate layer (C) is not particularly limited, but is, for example, preferably from 5 μm to 300 μm, and more preferably from 10 μm to 150 μm.

[0138] The intermediate layer (C) can be formed, for example, by applying a coating liquid onto the adhesive resin layer (A), the adhesive resin layer (B), or the base material layer 10 described later.

[0139] As a method for applying the coating liquid, a conventionally known coating method can be used, for example, a roller coating method, a reverse roller coating method, a gravure roller method, a rod coating method, a notch wheel coating method, a die coating method, etc. The drying conditions of the applied adhesive are not particularly limited. Generally speaking, it is preferably dried for 10 seconds to 10 minutes at a temperature range of 80 to 200° C. It is further preferably dried for 15 seconds to 5 minutes at 80 to 170° C. In order to fully promote the crosslinking reaction of the crosslinking agent and the adhesive, the coating liquid can be heated at 40 to 80° C. for about 5 to 300 hours after the drying of the coating liquid is completed.

[0140] In addition, the adhesive resin layer (A), the adhesive resin layer (B) or the substrate layer 10 and the intermediate layer (C) can be formed by co-extrusion molding, and the film-like adhesive resin layer (A), the adhesive resin layer (B) or the substrate layer 10 and the film-like intermediate layer (C) can be laminated (stacked) to form.

[0141] <Base material layer>

[0142] The adhesive film 50 according to this embodiment is as follows Figure 2As shown in FIG. 1 , in order to improve the handling properties, mechanical properties, heat resistance and other properties of the adhesive film 50, a base layer 10 can be further provided between the adhesive resin layer (A) and the adhesive resin layer (B). The base layer 10 can be, for example, Figure 2 As shown in the figure, it is provided between the adhesive resin layer (A) and the intermediate layer (C), and it may be provided between the adhesive resin layer (B) and the intermediate layer (C).

[0143] The base material layer 10 is not particularly limited, and examples thereof include resin films.

[0144] As the resin constituting the above-mentioned resin film, a known thermoplastic resin can be used. For example, one or more selected from polyolefins such as polyethylene, polypropylene, poly(4-methyl-1-pentene), and poly(1-butene); polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyamides such as nylon-6, nylon-66, and poly(m-xylylene adipamide); polyacrylates; polymethacrylates; polyvinyl chloride; polyvinylidene chloride; polyimides; polyetherimides; ethylene-vinyl acetate copolymers; polyacrylonitrile; polycarbonates; polystyrenes; ionomers; polysulfones; polyethersulfones; and polyphenylene oxides.

[0145] Among these, from the viewpoint of excellent balance among transparency, mechanical strength, price, etc., preferably, one or more selected from polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyimide are used, and more preferably, at least one selected from polyethylene terephthalate and polyethylene naphthalate are used.

[0146] The base layer 10 may be a single layer or may be two or more layers.

[0147] The resin film used to form the substrate layer 10 may be in the form of a stretched film or a film stretched uniaxially or biaxially. From the perspective of improving the mechanical strength of the substrate layer 10, a film stretched uniaxially or biaxially is preferred.

[0148] The thickness of the base layer 10 is preferably 1 μm to 500 μm, more preferably 5 μm to 300 μm, and further preferably 10 μm to 250 μm, from the viewpoint of obtaining good film properties.

[0149] The base material layer 10 may be subjected to a surface treatment in order to improve adhesion with other layers. Specifically, the base material layer 10 may be subjected to a corona treatment, a plasma treatment, an undercoat treatment, a primer coat treatment, or the like.

[0150] <Other floors>

[0151] The adhesive film 50 according to the present embodiment may further include, for example, an adhesive layer between the base layer 10 and the adhesive resin layer (A) or between the base layer 10 and the adhesive resin layer (B) within a range not impairing the effects of the present embodiment.

[0152] 2. Method for manufacturing electronic device

[0153] Next, a method for manufacturing the electronic device according to this embodiment will be described. Figure 3 and 4 It is a cross-sectional view schematically showing an example of a method for manufacturing an electronic device according to an embodiment of the present invention.

[0154] The method for manufacturing an electronic device according to this embodiment includes at least the following four steps.

[0155] Step (1) of preparing a structure 100, wherein the structure 100 comprises: an adhesive film 50 according to the present embodiment, an electronic component 70 attached to an adhesive resin layer (A) of the adhesive film 50, and a supporting substrate 80 attached to an adhesive resin layer (B) of the adhesive film 50,

[0156] Step (2), sealing the electronic component 70 with the sealing material 60,

[0157] Step (3), by applying an external stimulus, the adhesive force of the adhesive resin layer (B) is reduced, and the supporting substrate 80 is peeled off from the structure 100,

[0158] Step (4), peeling the adhesive film 50 from the electronic component 70,

[0159] Furthermore, in the method for manufacturing an electronic device according to the present embodiment, the adhesive film 50 according to the present embodiment described above is used as an adhesive film for temporarily fixing the electronic component 70 .

[0160] Hereinafter, each step of the method for manufacturing the electronic device according to the present embodiment will be described.

[0161] (Process (1))

[0162] First, a structure 100 including an adhesive film 50 , an electronic component 70 attached to an adhesive resin layer (A) of the adhesive film 50 , and a supporting substrate 80 attached to an adhesive resin layer (B) of the adhesive film 50 is prepared.

[0163] Such a structure 100 can be produced, for example, by the following steps.

[0164] First, the adhesive film 50 is adhered to the support substrate 80 in such a manner that the adhesive resin layer (B) is on the support substrate 80 side. A protective film may be attached to the adhesive resin layer (B), and the exposed surface of the adhesive resin layer (B) may be adhered to the support substrate 80 surface by peeling off the protective film.

[0165] As the support substrate 80 , for example, a quartz substrate, a glass substrate, a SUS substrate, or the like can be used.

[0166] Next, the structure 100 can be obtained by placing the electronic component 70 on the adhesive resin layer (A) of the adhesive film 50 adhered to the supporting substrate 80 .

[0167] Examples of the electronic component 70 include semiconductor chips such as ICs, LSIs, discrete components, light emitting diodes, and light receiving elements, semiconductor panels, and semiconductor packages.

[0168] (Process (2))

[0169] Next, the electronic component 70 is sealed with the sealing material 60 .

[0170] The electronic component 70 is covered with the sealing material 60 and the sealing material 60 is cured at a temperature of 150° C. or less, for example, to seal the electronic component 70 .

[0171] The form of the sealing material 60 is not particularly limited, and may be, for example, granular, sheet, or liquid.

[0172] The sealing material 60 is not particularly limited, and for example, an epoxy resin-based sealing material using epoxy resin can be used.

[0173] In view of improving the affinity of the sealing material 60 to the adhesive film 50 and being able to seal the electronic component 70 more uniformly, a liquid epoxy resin-based sealing material is particularly preferred.

[0174] As such an epoxy resin-based sealing material, for example, T693 / R4000 series, T693 / R1000 series, T693 / R5000 series, etc. manufactured by Nagase ChemteX Corporation can be used.

[0175] Examples of the sealing method include transfer molding, injection molding, compression molding, and casting molding. After the electronic component 70 is sealed with the sealing material 60, the sealing material 60 is cured by heating at a temperature of 150°C or less, to obtain the structure 100 in which the electronic component 70 is sealed.

[0176] (Process (3))

[0177] Next, by applying an external stimulus, the adhesive force of the adhesive resin layer (B) is reduced, and the supporting substrate 80 is peeled off from the structure 100 .

[0178] The support substrate 80 can be easily removed from the adhesive film 50 by, for example, heating the electronic component 70 to a temperature exceeding 150° C. to reduce the adhesive force of the adhesive resin layer (B).

[0179] (Process (4))

[0180] Next, the adhesive film 50 is removed from the electronic component 70 to obtain the electronic device 200 .

[0181] Examples of a method for removing the adhesive film 50 from the electronic component 70 include a method of mechanically peeling the adhesive film 50 and a method of peeling the adhesive film 50 after reducing the adhesive force on the surface of the adhesive film 50 .

[0182] (Process (5))

[0183] In the method for manufacturing an electronic device according to this embodiment, Figure 4 As shown, the process further includes a step (5) of forming a wiring layer 310 and a bump 320 on the exposed surface of the obtained electronic device 200 to obtain an electronic device 300 .

[0184] The wiring layer 310 includes pads (not shown) formed on the outermost surface as external connection terminals and wiring (not shown) electrically connecting the exposed electronic components 70 to the pads. The wiring layer 310 can be formed by a conventionally known method and may have a multilayer structure.

[0185] Furthermore, a bump 320 can be formed on the pad of the wiring layer 310 to obtain the electronic device 300. Examples of the bump 320 include a solder bump and a metal bump. The solder bump can be formed, for example, by placing a solder ball on the pad of the wiring layer 310 as an external connection terminal and heating to melt the solder (reflow). The metal bump can be formed by a ball bonding method, a plating method, an Au ball transfer method, or the like.

[0186] (Process (6))

[0187] In the method for manufacturing an electronic device according to this embodiment, Figure 4 As shown, the method further includes step (6): cutting the electronic device 300 to obtain a plurality of electronic devices 400 .

[0188] The electronic device 300 can be cut using a known method.

[0189] As mentioned above, although embodiment of this invention was described, these are illustrations of this invention, and various structures other than the above-mentioned can also be adopted.

[0190] In addition, the present invention is not limited to the above-mentioned embodiment, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are also included in the present invention.

[0191] Example

[0192] Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

[0193] The details of the materials used for preparing the adhesive films in Examples and Comparative Examples are as follows.

[0194] <Adhesive coating liquid A for forming adhesive resin layer (A)>

[0195] (Preparation of Adhesive Resin Solution A1)

[0196] In deionized pure water, 0.5 parts by mass of 4,4'-azobis-4-cyanovaleric acid (manufactured by Otsuka Chemical Co., Ltd., trade name: ACVA) as a polymerization initiator, 74.3 parts by mass of n-butyl acrylate and 13.7 parts by mass of methyl methacrylate as monomers (A), 9 parts by mass of 2-hydroxyethyl methacrylate as monomer (B), and 3 parts by mass of a substance having a polymerizable 1-propenyl group introduced into the benzene ring of the ammonium salt of the sulfate ester of polyoxyethylene nonylphenyl ether (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Akulon HS-1025) as a polymerizable surfactant were added. Then, emulsion polymerization was carried out at 70-72°C for 8 hours under stirring to obtain an acrylic resin emulsion. It was neutralized with ammonia water (pH = 7.0) to obtain an adhesive resin solution A1 with a solid content concentration of 42.5%.

[0197] (Preparation of Adhesive Resin Solution A2)

[0198] In deionized pure water, 0.5 parts by mass of ammonium persulfate as a polymerization initiator, 63 parts by mass of 2-ethylhexyl acrylate, 21 parts by mass of n-butyl acrylate and 9 parts by mass of methyl methacrylate as monomers (A), 3 parts by mass of 2-hydroxyethyl methacrylate as monomers (B), 1 part by mass of polytetramethylene glycol diacrylate (manufactured by NOF Corporation, trade name: ADT-250) as monomers (C), and 2 parts by mass of a substance having a polymerizable 1-propenyl group introduced into the benzene ring of an ammonium salt of a sulfate ester of polyoxyethylene nonylphenyl ether (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Akulon HS-1025) as a polymerizable surfactant were added, and emulsion polymerization was carried out at 70 to 72° C. for 8 hours under stirring to obtain an acrylic resin emulsion. This was neutralized with aqueous ammonia (pH=7.0) to obtain an adhesive resin solution A2 having a solid content concentration of 56.5%.

[0199] (Preparation of Adhesive Coating Liquid A)

[0200] 50 parts by mass of the adhesive resin solution A1, 50 parts by mass of the adhesive resin solution A2, 0.3 parts by mass of dimethylethanolamine, and 6 parts by mass of an epoxy compound (Ex-1610 manufactured by Nagase ChemteX Co., Ltd.) as a crosslinking agent were mixed to obtain an adhesive coating liquid A.

[0201] <Adhesive coating liquid B for forming adhesive resin layer (B)>

[0202] (Preparation of polymer A solution)

[0203] 74 parts by mass of n-butyl acrylate, 16 parts by mass of methyl methacrylate, 7 parts by mass of 2-hydroxyethyl methacrylate and 3 parts by mass of acrylic acid were copolymerized in a mixed solvent of toluene and ethyl acetate to obtain a polymer A solution having a concentration of 45% by mass and a molecular weight of 250,000.

[0204] (Preparation of Adhesive Coating Liquid B)

[0205] The polymer A solution, an isocyanate compound as a crosslinking agent (olester P49-75S manufactured by Mitsui Chemicals, Inc.), heat-expandable microspheres with an expansion starting temperature of 160°C, and a thickener (Pensel D125 manufactured by Arakawa Chemical Co., Ltd.) were mixed in a ratio of 100:2:15:5 (solid content mass ratio) to obtain an adhesive coating liquid B.

[0206] <Coating liquid C for forming intermediate layer (C)>

[0207] (Preparation of polymer A solution)

[0208] 74 parts by mass of n-butyl acrylate, 16 parts by mass of methyl methacrylate, 7 parts by mass of 2-hydroxyethyl methacrylate and 3 parts by mass of acrylic acid were copolymerized in a mixed solvent of toluene and ethyl acetate to obtain a polymer A solution having a concentration of 45% by mass and a molecular weight of 250,000.

[0209] (Preparation of polymer B solution)

[0210] 35 parts by mass of 2-ethylhexyl acrylate, 41 parts by mass of n-butyl acrylate, 15 parts by mass of ethyl acrylate and 9 parts by mass of 2-hydroxyethyl methacrylate were copolymerized in a mixed solvent of toluene and ethyl acetate under a nitrogen atmosphere to obtain a polymer B solution having a molecular weight of 300,000.

[0211] (Preparation of coating liquid C)

[0212] The polymer A solution and an epoxy compound (Tetrad C, manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a crosslinking agent were mixed at a ratio of 100:1 (solid content mass ratio) to obtain a coating liquid C1.

[0213] In addition, except having changed the kind of polymer solution, the kind and the compounding amount of the crosslinking agent into the values ​​described in Table 1, it carried out similarly to the coating liquid C1, and prepared the coating liquids C1 to C9, respectively.

[0214] In addition, the epoxy compound in Table 1 is Tetrad C (produced by Mitsubishi Gas Chemical Co., Ltd.), and the isocyanate compound is Olester P49-75S (produced by Mitsui Chemicals, Inc.).

[0215] [Example 1]

[0216] On a polyethylene terephthalate (PET) film (38 μm thick) as a substrate layer, an adhesive coating liquid A was applied and dried to form an adhesive resin layer (A) having a thickness of 13 μm. Next, a coating liquid C1 was applied to the surface of the PET film on the opposite side to the adhesive resin layer (A) and dried to form an intermediate layer (C) having a thickness of 20 μm. Next, an adhesive coating liquid B was applied to the intermediate layer (C) and dried to form an adhesive resin layer (B) having a thickness of 25 μm, thereby obtaining an adhesive film.

[0217] The following evaluations were performed on the obtained adhesive films. The obtained results are shown in Table 1.

[0218] [Examples 2 to 6 and Comparative Examples 1 to 3]

[0219] Adhesive films were produced in the same manner as in Example 1 except that coating liquids C2 to C9 were used respectively in place of coating liquid C1.

[0220] The following evaluations were performed on the obtained adhesive films. The obtained results are shown in Table 1, respectively.

[0221] [Comparative Example 4]

[0222] An adhesive film was produced in the same manner as in Example 1 except that the intermediate layer (C) was not formed.

[0223] The following evaluations were performed on the obtained adhesive films. The obtained results are shown in Table 1, respectively.

[0224] <Evaluation>

[0225] (1) Measurement of storage elastic modulus E' and loss tangent (tanδ) of the intermediate layer (C) at 120°C

[0226] Coating solutions C1 to C9 were applied onto release films to a dry thickness of 20 μm, and then dried in an oven at 110° C. for 3 minutes. The samples were then stacked until the sample thickness reached 1 mm, thereby obtaining samples for viscoelasticity measurement.

[0227] Next, the solid viscoelasticity of the intermediate layer (C) was measured using a solid viscoelasticity measuring apparatus (RSA-3, manufactured by TA Instrument) under the conditions of a frequency of 1 Hz, a heating rate of 5°C / min, a strain of 0.05%, a chuck distance of 20 mm, and a sample width of 10 mm, and the storage elastic modulus E' and the loss tangent (tanδ) of the intermediate layer (C) at 120°C were calculated.

[0228] (2) Paste residue on the supporting substrate

[0229] The adhesive resin layer (B) of the adhesive film obtained in the examples and comparative examples was attached to a supporting substrate, and a plurality of silicon wafers were placed on the adhesive resin layer (A).

[0230] Next, after being placed at 23°C for 1 minute, a compression molding machine (WCM-300MC, manufactured by APIC YAMADA) was used to seal the multiple silicon wafers arranged on the adhesive resin layer (A) at a temperature of 120°C for 3 minutes using a liquid epoxy resin sealant (T693 / R4212, manufactured by Nagase ChemteX).

[0231] Next, the supporting substrate / adhesive film / silicon wafer / sealing material structure is taken out from the compression molding machine, heated in an oven at 150°C for 30 minutes, and then the adhesive resin layer (B) is foamed at 185°C to separate the supporting substrate from the adhesive film / silicon wafer / sealing material structure.

[0232] Next, the surface of the supporting substrate after the detachment was visually observed to confirm the paste residue of the adhesive film on the surface of the supporting substrate, and the paste residue of the adhesive film was evaluated according to the following criteria.

[0233] ○: No paste residue was observed on the surface of the supporting substrate by visual inspection.

[0234] ×: Paste residue was observed on the surface of the supporting substrate by visual inspection.

[0235] [Table 1]

[0236]

[0237] The storage elastic modulus E' of the intermediate layer (C) at 120°C is 1.0×10 5 Pa above 8.0×10 6 In Examples 1 to 6 of the adhesive films having a loss tangent (tan δ) of 0.1 or less at 120°C of the intermediate layer (C), no paste residue was observed on the supporting substrate. Therefore, it can be understood that the adhesive films of Examples 1 to 6 can suppress the paste residue on the supporting substrate side when the adhesive film is peeled off from the supporting substrate.

[0238] On the other hand, the storage elastic modulus E' of the intermediate layer (C) at 120°C is less than 1.0×10 5 In Comparative Examples 2 and 3 of the adhesive films having a loss tangent (tan δ) of more than 0.1, or Comparative Example 1 of the adhesive film having a loss tangent (tan δ) of more than 0.1 at 120°C using an intermediate layer (C), or Comparative Example 4 of the adhesive film without the intermediate layer (C), the paste residue was observed on the supporting substrate. Therefore, it can be understood that in the adhesive films of Comparative Examples 1 to 4, when the adhesive films are peeled off from the supporting substrate, the paste residue is generated on the supporting substrate side.

Claims

1. An adhesive film for temporarily fixing an electronic component when the electronic component is sealed by a sealing material in a manufacturing process of an electronic device, comprising: An adhesive resin layer (A) for temporarily fixing the electronic component, An adhesive resin layer (B) for bonding to a supporting substrate and having adhesive strength reduced by external stimulation, and an intermediate layer (C) provided between the adhesive resin layer (A) and the adhesive resin layer (B), The storage elastic modulus E' of the intermediate layer (C) at 120°C is 1.0×10 5 Pa above 8.0×10 6 Pa or less, and the loss tangent (tan δ) of the intermediate layer (C) at 120°C is 0.1 or less, The intermediate layer (C) contains a (meth)acrylic resin and a crosslinking agent having two or more crosslinkable functional groups in one molecule. 2 . The adhesive film according to claim 1 , wherein the adhesive strength of the adhesive resin layer (B) is reduced by heating. 3 . The adhesive film according to claim 2 , wherein the adhesive resin layer (B) contains at least one selected from the group consisting of a gas generating component and heat-expandable microspheres.

4. The adhesive film according to any one of claims 1 to 3, wherein when the entire adhesive resin layer (A) is set to 100 mass %, the content of at least one selected from the group consisting of a gas generating component and heat-expandable microspheres in the adhesive resin layer (A) is 0.1 mass % or less. 5 . The adhesive film according to claim 1 , wherein the sealing material is an epoxy resin-based sealing material. 6 . The adhesive film according to claim 1 , wherein the adhesive resin layer (A) comprises a (meth)acrylic adhesive resin.

7. A method for manufacturing an electronic device, comprising at least the following steps: Step (1), preparing a structure comprising: the adhesive film according to any one of claims 1 to 6, an electronic component attached to the adhesive resin layer (A) of the adhesive film, and a supporting substrate attached to the adhesive resin layer (B) of the adhesive film; Step (2), sealing the electronic component with a sealing material; Step (3), reducing the adhesive force of the adhesive resin layer (B) by applying an external stimulus, thereby peeling the supporting substrate from the structure; and Step (4) of peeling the adhesive film from the electronic component. 8 . The method for manufacturing an electronic device according to claim 7 , wherein the sealing material is an epoxy resin-based sealing material.

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