Adhesive film and method for manufacturing electronic device

Abstract

An adhesive film (50) comprising: a film (1) including an adhesive resin layer (A), a substrate layer (B), and an adhesive resin layer (C) in this order, the adhesive resin layer (C) being capable of reducing adhesive strength by means of external stimulation; and a film (2) including a substrate layer (D) and an adhesive resin layer (E) in this order, wherein the adhesive resin layer (C) and the substrate layer (D) are in direct contact with each other.

Description

Method for manufacturing adhesive film and electronic device

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

[0002] Fan-out packaging is known as a technology that can reduce the size and weight of electronic devices (e.g., semiconductor devices). One method for fabricating a fan-out package, called an embedded wafer level ball grid array (eWLB), involves temporarily fixing a plurality of electronic components, such as semiconductor chips, spaced apart on an adhesive film attached to a support substrate, and then encapsulating the plurality of electronic components together with an encapsulant. Here, the adhesive film must be adhered to the electronic components and the support substrate during the encapsulation process, and must be removed from the encapsulated electronic components together with the support substrate after encapsulation.

[0003] Techniques relating to a manufacturing method for such a fan-out type package include, for example, the technique described in Patent Document 1 (Japanese Patent Laid-Open No. 2011-134811).

[0004] Patent Document 1 describes a heat-resistant adhesive sheet for semiconductor device manufacturing that is used by adhering when resin-encapsulating a substrateless semiconductor chip, with the aim of solving the problem of the chip not being held in place due to pressure during resin encapsulation and shifting from its designated position, or the problem of the package being damaged when the heat-resistant adhesive sheet for semiconductor device manufacturing is peeled off due to the hardening of the encapsulant or heat causing the encapsulant to become strongly adhesive to the chip surface, the heat-resistant adhesive sheet having a base layer and an adhesive layer, the adhesive layer having an adhesive strength to SUS304 after lamination of 0.5 N / 20 mm or more, and hardening due to stimuli received up to the time the resin encapsulation process is completed, so that the peel strength to the package is 2.0 N / 20 mm or less.

[0005] JP 2011-134811 A

[0006] According to the investigations of the present inventors, it has become clear that when peeling an adhesive film from a support substrate or an electronic component, peeling failure between the support substrate or the electronic component and the adhesive film may occur. The present invention has been made in view of the above circumstances, and provides an adhesive film with improved peelability from the support substrate or the electronic component.

[0007] The present inventors have conducted extensive research to achieve the above object, and as a result have found that the use of a pressure-sensitive adhesive film having a specific layer structure can improve the releasability from a supporting substrate or an electronic component, thereby completing the present invention.

[0008] According to the present invention, the following methods for producing a pressure-sensitive adhesive film and an electronic device are provided.

[0009] [1] An adhesive film comprising: a film 1 having, in this order, an adhesive resin layer (A), a base layer (B), and an adhesive resin layer (C) capable of reducing adhesive strength in response to an external stimulus; and a film 2 having, in this order, a base layer (D) and an adhesive resin layer (E), wherein the adhesive resin layer (C) is in direct contact with the base layer (D). [2] An adhesive film having, in this order, an adhesive resin layer (A), a base layer (B), an adhesive resin layer (C) capable of reducing adhesive strength in response to an external stimulus, the base layer (D), and an adhesive resin layer (E). [3] The adhesive film according to [1] or [2] above, wherein the adhesive resin layer (A) comprises one or more resins selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins. [4] The pressure-sensitive adhesive film according to any one of [1] to [3] above, wherein the total content of the gas-generating component and heat-expandable microspheres in the pressure-sensitive adhesive resin layer (A) is 0.1% by mass or less, when the entire pressure-sensitive adhesive resin layer (A) is taken as 100% by mass. [5] The pressure-sensitive adhesive film according to any one of [1] to [4] above, wherein the pressure-sensitive adhesive resin layer (A) has a thickness of 1 μm or more and 40 μm or less. [6] The pressure-sensitive adhesive film according to any one of [1] to [5] above, wherein the base layer (B) comprises one or more selected from the group consisting of polyolefin, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, polyimide, and ethylene-vinyl acetate copolymer. [7] The pressure-sensitive adhesive film according to any one of [1] to [6] above, wherein the base layer (B) has a thickness of 1 μm or more and 300 μm or less. [8] The pressure-sensitive adhesive film according to any one of [1] to [7] above, wherein the external stimulus comprises one or more selected from the group consisting of light irradiation and heat treatment. [9] The pressure-sensitive adhesive film according to any one of [1] to [8] above, wherein the pressure-sensitive adhesive resin layer (C) comprises a layer whose adhesive strength decreases by heat treatment.

[10] The pressure-sensitive adhesive film according to [9] above, wherein the pressure-sensitive adhesive resin layer (C) comprises one or more selected from the group consisting of a gas-generating component and heat-expandable microspheres.

[11] The pressure-sensitive adhesive film according to [9] or

[10] above, wherein the adhesive strength of the adhesive resin layer (C) decreases when heated at a temperature exceeding 100°C.

[12] The pressure-sensitive adhesive film according to any one of [1] to

[11] above, wherein the adhesive resin layer (C) comprises one or more resins selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins.

[13] The pressure-sensitive adhesive film according to any one of [1] to

[12] above, wherein the adhesive resin layer (C) has a thickness of 10 μm or more and 100 μm or less.

[14] The pressure-sensitive adhesive film according to any one of [1] to

[13] above, wherein the base layer (D) comprises one or more resins selected from the group consisting of polyolefins, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamides, polyimides, and ethylene-vinyl acetate copolymers.

[15] The pressure-sensitive adhesive film according to any one of [1] to

[14] above, wherein the thickness of the base material layer (D) is 1 μm or more and 300 μm or less.

[16] The pressure-sensitive adhesive film according to any one of [1] to

[15] above, wherein the pressure-sensitive adhesive resin layer (E) contains one or more resins selected from the group consisting of (meth)acrylic pressure-sensitive adhesive resins, silicone pressure-sensitive adhesive resins, urethane pressure-sensitive adhesive resins, olefin pressure-sensitive adhesive resins, and styrene pressure-sensitive adhesive resins.

[17] The pressure-sensitive adhesive film according to any one of [1] to

[16] above, wherein the total content of the gas-generating component and heat-expandable microspheres in the pressure-sensitive adhesive resin layer (E) is 0.1 mass% or less, when the entire pressure-sensitive adhesive resin layer (E) is taken as 100 mass%.

[18] The pressure-sensitive adhesive film according to any one of [1] to

[17] above, wherein the thickness of the pressure-sensitive adhesive resin layer (E) is 1 μm or more and 40 μm or less.

[19] The pressure-sensitive adhesive film according to any one of the above [1] to

[18] , further comprising an intermediate layer (F) between at least one selected from the group consisting of the adhesive resin layer (A) and the base layer (B), the base layer (B) and the adhesive resin layer (C), and the base layer (D) and the adhesive resin layer (E).

[20] The pressure-sensitive adhesive film according to the above

[19] , wherein the thickness of the intermediate layer (F) is 1 μm or more and 400 μm or less.

[21] The pressure-sensitive adhesive film according to any one of [1] to

[20] above, which is capable of temporarily fixing an electronic component when sealing the electronic component with a sealing material.

[22] The pressure-sensitive adhesive film according to any one of [1] to

[20] above, which is a backgrinding tape.

[23] A method for manufacturing an electronic device, comprising the steps of: preparing a structure comprising a support substrate on one side of the pressure-sensitive adhesive film according to any one of [1] to

[20] above and an electronic component on the other side of the pressure-sensitive adhesive film; and reducing the adhesive strength of the pressure-sensitive adhesive resin layer (C) by an external stimulus, thereby peeling the pressure-sensitive adhesive resin layer (C) from the base layer (D).

[24] The method for manufacturing an electronic device according to

[23] above, wherein the step of preparing the structure comprises the steps of bonding the pressure-sensitive adhesive resin layer (C) to the base layer (D) together, and bonding one side of the pressure-sensitive adhesive film to the support substrate.

[25] A method for producing an electronic device according to

[23] or

[24] above, further comprising a step of peeling the pressure-sensitive adhesive film from the electronic component.

[26] A method for producing an electronic device according to any one of

[23] to

[25] above, further comprising a step of encapsulating the electronic component with an encapsulant between the step of preparing the structure and the step of peeling the pressure-sensitive adhesive resin layer (C) and the base material layer (D).

[27] A method for producing an electronic device according to

[26] above, wherein the encapsulant comprises one or more selected from the group consisting of epoxy resin-based encapsulants and silicone resin-based encapsulants.

[28] A method for producing an electronic device according to any one of

[23] to

[27] above, wherein the electronic device comprises a fan-out package.

[29] A method for producing an electronic device, comprising, in this order: preparing a structure comprising an electronic component on one side of the pressure-sensitive adhesive film according to any one of [1] to

[20] above; and back-grinding the electronic component.

[30] The method for manufacturing an electronic device according to

[29] above, wherein the electronic component comprises one or more selected from the group consisting of a semiconductor wafer and a mold wafer.

[31] The method for manufacturing an electronic device according to

[30] above, wherein the semiconductor wafer is a silicon wafer, a sapphire wafer, an indium-phosphorus wafer, a silicon-carbon wafer, a gallium-nitrogen wafer, a gallium-oxygen wafer, a gallium-arsenic wafer, a silicon wafer, a germanium wafer, a germanium-arsenic wafer, a gallium-phosphorus wafer, a gallium-arsenic-aluminum wafer, an indium-gallium-nitrogen wafer, a gallium-arsenic-phosphorus wafer, a glass wafer, or a lithium tantalate wafer.

[32] The method for manufacturing an electronic device according to

[30] or

[31] above, wherein the electronic component includes a circuit formation surface.

[0010] According to the present invention, it is possible to provide a pressure-sensitive adhesive film that has improved releasability from a supporting substrate or an electronic component.

[0011] 1 is a cross-sectional view schematically showing an example of the structure of an adhesive film according to an embodiment of the present invention. 2 is a cross-sectional view schematically showing an example of the structure of an adhesive film according to an embodiment of the present invention. 3 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. 4 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. 5 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.

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by common reference numerals, and descriptions thereof will be omitted where appropriate. Furthermore, the drawings are schematic diagrams and do not necessarily correspond to actual dimensional ratios. In the specification, the expression "A to B" regarding a numerical range means A or more and B or less, unless otherwise specified. For example, 1 to 5% means 1% or more and 5% or less. In the specification, "(meth)acrylic" means acrylic, methacrylic, or both acrylic and methacrylic.

[0013] <Adhesive Film> The adhesive film of this embodiment will be described below. In one aspect of the adhesive film 50 of this embodiment, as shown in Fig. 1 , the adhesive film 50 of this embodiment comprises a film 1 including, in this order, an adhesive resin layer (A), a base layer (B), and an adhesive resin layer (C) that can reduce adhesive strength in response to an external stimulus, and a film 2 including, in this order, a base layer (D) and an adhesive resin layer (E), and the adhesive film 50 is used so that the adhesive resin layer (C) and the base layer (D) are in direct contact with each other.

[0014] In one aspect of the adhesive film 50 of the present embodiment, as shown in FIG. 2 , the adhesive film 50 of the present embodiment comprises an adhesive resin layer (A), a base layer (B), an adhesive resin layer (C) capable of reducing adhesive strength in response to an external stimulus, a base layer (D), and an adhesive resin layer (E) in this order.

[0015] According to the studies of the present inventors, it has become clear that when peeling an adhesive film from a support substrate or electronic component, peeling failure between the support substrate or electronic component and the adhesive film may occur. The present invention can improve peelability from the support substrate or electronic component by using an adhesive film having a specific layer structure. Although the reason for this is unclear, it is thought that by limiting the material of the layer in contact with the layer that can reduce adhesive strength in response to an external stimulus to a component that facilitates peeling, the adhesive film can be stably peeled from the support substrate or electronic component regardless of the material of the support substrate or electronic component.

[0016] Next, each layer constituting the adhesive film 50 of this embodiment will be described.

[0017] [Adhesive Resin Layer (A)] The film 1 and the adhesive film 50 of the present embodiment include an adhesive resin layer (A) on one surface of the base layer (B) from the viewpoint of suppressing misalignment of the electronic component 70. The adhesive resin layer (A) is a layer that comes into contact with the surface of an electronic component or a supporting substrate to temporarily fix the electronic component or the supporting substrate, for example, when sealing the electronic component with a sealing material in the manufacturing process of an electronic device.

[0018] The adhesive resin layer (A) preferably contains an adhesive resin (Aa). The adhesive resin (Aa) preferably contains one or more selected from the group consisting of (meth)acrylic adhesive resin (a), silicone adhesive resin, urethane adhesive resin, olefin adhesive resin, and styrene adhesive resin. Among these, the adhesive resin (Aa) preferably contains a (meth)acrylic adhesive resin (a) from the viewpoint of suppressing misalignment of the electronic component 70 and improving the performance balance of adhesive strength.

[0019] The adhesive resin layer (A) may be a radiation-crosslinkable adhesive resin layer whose adhesive strength can be reduced by radiation. When the radiation-crosslinkable adhesive resin layer is irradiated with radiation, crosslinking occurs, significantly reducing the adhesive strength, making it easier to peel the film 1 and the adhesive film 50 from the electronic component. Examples of radiation include ultraviolet light, electron beams, and infrared light. The radiation-crosslinkable adhesive resin layer preferably includes an ultraviolet-crosslinkable adhesive resin layer.

[0020] The (meth)acrylic adhesive resin (a) used in the adhesive resin layer (A) of this embodiment preferably comprises a copolymer containing (meth)acrylic acid alkyl ester monomer units (a1) and monomer units (a2) having a functional group capable of reacting with a crosslinking agent. In this embodiment, the (meth)acrylic acid alkyl ester refers to an acrylic acid alkyl ester, a methacrylic acid alkyl ester, or a mixture thereof.

[0021] The (meth)acrylic adhesive resin (a) of the present embodiment can be obtained, for example, by copolymerizing a monomer mixture containing a (meth)acrylic acid alkyl ester monomer and a monomer having a functional group capable of reacting with a crosslinking agent.

[0022] The (meth)acrylic acid alkyl ester monomer of this embodiment preferably includes a (meth)acrylic acid alkyl ester having an alkyl group having about 1 to 12 carbon atoms, and more preferably includes a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms. The (meth)acrylic acid alkyl ester having an alkyl group having about 1 to 12 carbon atoms preferably includes one or more selected from the group consisting of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. In the (meth)acrylic adhesive resin (a) of this embodiment, the content of the (meth)acrylic acid alkyl ester monomer unit (a1) is preferably 10% by mass or more and 98.9% by mass or less, more preferably 50% by mass or more and 97% by mass or less, and even more preferably 85% by mass or more and 95% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is taken as 100% by mass.

[0023] Preferred examples of the monomer having a functional group reactive with the crosslinking agent of this embodiment include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, monoalkyl itaconic acid esters, monoalkyl mesaconic acid esters, monoalkyl citraconic acid esters, monoalkyl fumaric acid esters, monoalkyl maleic acid esters, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tert-butylaminoethyl acrylate, tert-butylaminoethyl methacrylate, etc. More preferred examples of the monomer having a functional group reactive with the crosslinking agent of this embodiment include one or more selected from the group consisting of acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, and methacrylamide. In the (meth)acrylic adhesive resin (a) of the present embodiment, the content of the monomer unit (a2) having a functional group capable of reacting with a crosslinking agent is preferably 1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 20% by mass or less, and even more preferably 1% by mass or more and 10% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is 100% by mass.

[0024] The (meth)acrylic adhesive resin (a) of this embodiment may further contain, in addition to the (meth)acrylic acid alkyl ester monomer unit (a1) and the monomer unit (a2) having a functional group reactive with a crosslinking agent, a bifunctional monomer unit (a3) ​​or a specific comonomer unit having surfactant properties (hereinafter referred to as a polymerizable surfactant). The polymerizable surfactant has the property of copolymerizing with the (meth)acrylic acid alkyl ester monomer, the monomer having a functional group reactive with a crosslinking agent, and the bifunctional monomer, and also acts as an emulsifier when emulsion polymerization is performed.

[0025] The bifunctional monomer of the present embodiment preferably includes one or more monomers selected from the group consisting of 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, monomers having diacrylate or dimethacrylate at both ends and a propylene glycol main chain structure (e.g., manufactured by NOF Corporation, trade names: PDP-200, PDP-400, ADP-200, ADP-400), tetramethylene glycol monomers (e.g., manufactured by NOF Corporation, trade names: ADT-250, ADT-850), and mixtures thereof (e.g., manufactured by NOF Corporation, trade names: ADET-1800, ADPT-4000).

[0026] In the (meth)acrylic adhesive resin (a) of the present embodiment, the content of the bifunctional monomer unit (a3) ​​is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 20% by mass or less, even more preferably 0.1% by mass or more and 15% by mass or less, and still more preferably 0.1% by mass or more and 5% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is 100% by mass.

[0027] The polymerizable surfactant of this embodiment preferably includes one or more surfactants selected from the group consisting of polyoxyethylene nonylphenyl ether having a polymerizable 1-propenyl group introduced into the benzene ring (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: AQUALON RN-10, RN-20, RN-30, RN-50, etc.), polyoxyethylene nonylphenyl ether sulfate ammonium salt having a polymerizable 1-propenyl group introduced into the benzene ring (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: AQUALON HS-10, HS-20, HS-1025, etc.), and sulfosuccinic acid diesters having a polymerizable double bond in the molecule (manufactured by Kao Corporation; trade names: Latemul S-120A, S-180A, etc.). In the (meth)acrylic adhesive resin (a) of the present embodiment, the content of the polymerizable surfactant is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 20% by mass or less, even more preferably 0.1% by mass or more and 15% by mass or less, and still more preferably 0.1% by mass or more and 5% by mass or less, when the sum of all monomer units in the (meth)acrylic adhesive resin (a) is 100% by mass.

[0028] The (meth)acrylic adhesive resin (a) of the present embodiment may further contain, if necessary, a monomer unit formed from a monomer having a polymerizable double bond, such as vinyl acetate, acrylonitrile, or styrene.

[0029] The polymerization reaction mechanism of the (meth)acrylic adhesive resin (a) of this embodiment may be radical polymerization, anionic polymerization, cationic polymerization, or the like. Considering the production cost of the (meth)acrylic adhesive resin (a), the influence of the functional groups of the monomers, and the influence of ions on the surface of electronic components, polymerization by radical polymerization is preferred. When polymerization by radical polymerization is performed, the (meth)acrylic adhesive resin (a) of this embodiment preferably contains a radical polymerization initiator. The radical polymerization initiator of this embodiment is preferably benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, 3,3,5-trimethylhexanoyl peroxide, di-2-ethylhexyl peroxydicarbonate, methyl ethyl ketone peroxide, t-butyl peroxyphthalate, t-butyl peroxybenzoate, di-t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butylperoxy-2-hexanoate, or t-butylperoxy-2-ethylhexanoate. The peroxides may include one or more compounds selected from the group consisting of organic peroxides such as t-butylperoxy-3,5,5-trimethylhexanoate, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, t-butyl peroxide, and di-t-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.

[0030] When polymerized by emulsion polymerization, the (meth)acrylic adhesive resin (a) of this embodiment preferably contains one or more compounds selected from the group consisting of water-soluble inorganic peroxides such as ammonium persulfate, potassium persulfate, and sodium persulfate; and azo compounds having a carboxyl group in the molecule, such as water-soluble 4,4'-azobis-4-cyanovaleric acid. Furthermore, in consideration of the influence of ions on the surface of electronic components, the (meth)acrylic adhesive resin (a) more preferably contains an azo compound having a carboxyl group in the molecule, such as ammonium persulfate or 4,4'-azobis-4-cyanovaleric acid, and even more preferably contains an azo compound having a carboxyl group in the molecule, such as 4,4'-azobis-4-cyanovaleric acid.

[0031] From the viewpoint of suppressing misalignment of the electronic component 70 and improving the performance balance of adhesive strength, the adhesive resin layer (A) of this embodiment preferably further contains, in addition to the adhesive resin (Aa), a crosslinking agent (Ab) having two or more crosslinkable functional groups per molecule. The crosslinking agent (Ab) having two or more crosslinkable functional groups per molecule can be reacted with the functional groups of the adhesive resin (Aa) and used to adjust the adhesive strength and cohesive strength. The crosslinking agent (Ab) of the present embodiment is preferably an epoxy-based crosslinking agent such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, or resorcinol diglycidyl ether; an isocyanate-based crosslinking agent such as tetramethylene diisocyanate, hexamethylene diisocyanate, a toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, or tolylene diisocyanate; trimethylolpropane-tri-β-aziridinyl propionate, tetramethylolpropane-tri-β-aziridinyl propionate, or tetramethylolpropane-tri-β-aziridinyl propionate; The crosslinking agent may comprise one or more crosslinkers selected from the group consisting of aziridine-based crosslinkers such as tyrolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate; tetrafunctional epoxy-based crosslinkers such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine-based crosslinkers such as hexamethoxymethylolmelamine. Among these, the crosslinking agent (Ab) of this embodiment preferably includes one or more crosslinking agents selected from the group consisting of epoxy-based crosslinking agents, isocyanate-based crosslinking agents, and aziridine-based crosslinking agents, from the viewpoint of being able to improve the performance balance between suppressing misalignment of the electronic component 70 and adhesive strength.

[0032] The content of the crosslinking agent (Ab) is preferably within a range such that the number of functional groups in the crosslinking agent (Ab) is not greater than the number of functional groups in the adhesive resin (Aa). However, an excess amount of the crosslinking agent (Ab) may be added as necessary when new functional groups are generated by the crosslinking reaction or when the crosslinking reaction is slow. The content of the crosslinking agent (Ab) in the adhesive resin layer (A) is preferably 0.1 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the adhesive resin (Aa), from the viewpoint of suppressing misalignment of the electronic component 70 in the adhesive resin layer (A) and improving the performance balance between heat resistance and adhesion.

[0033] The adhesive resin layer (A) may contain additives such as plasticizers and tackifier resins as other components. When the adhesive resin layer (A) is a radiation-crosslinkable adhesive resin layer, it may contain various additives for radiation crosslinking. The total content of the adhesive resin (Aa) and the crosslinking agent (Ab) in the adhesive resin layer (A) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on 100% by mass of the entire adhesive resin layer (A), from the viewpoint of suppressing misalignment of the electronic component 70. Furthermore, the upper limit of the total content of the adhesive resin (Aa) and the crosslinking agent (Ab) in the adhesive resin layer (A) is not particularly limited, but may be, for example, 100% by mass or less.

[0034] In the film 1 and the adhesive film 50 of this embodiment, from the viewpoint of stably holding the electronic component 70 when the support substrate is peeled off from the adhesive film 50, the total content of the gas-generating component and heat-expandable microspheres in the adhesive resin layer (A) is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, and even more preferably 0.01% by mass or less, based on 100% by mass of the entire adhesive resin layer (A). More preferably, the adhesive resin layer (A) does not contain any gas-generating component or heat-expandable microspheres.

[0035] The adhesive resin layer (A) may be a single layer or a multilayer. The thickness of the adhesive resin layer (A) is preferably 1 μm or more and 40 μm or less, more preferably 3 μm or more and 35 μm or less, and even more preferably 5 μm or more and 30 μm or less.

[0036] The adhesive resin layer (A) can be formed, for example, by applying an adhesive onto the substrate layer (B). The adhesive may be dissolved in a solvent and applied as a coating liquid, or may be applied as an aqueous emulsion, or the liquid adhesive may be directly applied. Among these, the adhesive is preferably an aqueous emulsion coating liquid. Examples of aqueous emulsion coating liquids include coating liquids in which a (meth)acrylic adhesive resin, a silicone adhesive resin, a urethane adhesive resin, an olefin adhesive resin, a styrene adhesive resin, or the like is dispersed in water. An adhesive coating liquid dissolved in an organic solvent may also be used. The organic solvent is not particularly limited, and may be appropriately selected from known organic solvents in consideration of solubility and drying time. The organic solvent of the present embodiment preferably includes one or more selected from the group consisting of 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 solvents such as heptane, hexane, and cyclohexane; and alcohols such as isopropanol and butanol, and more preferably includes one or two selected from the group consisting of ethyl acetate and toluene.

[0037] The adhesive coating liquid can be applied using conventional coating methods such as a roll coater method, a reverse roll coater method, a gravure roll method, a bar coater method, a comma coater method, or a die coater method. The drying conditions for the applied adhesive are not particularly limited, but generally, drying is preferably performed for 10 seconds to 10 minutes at a temperature range of 80 to 200°C. Drying for 15 seconds to 5 minutes at 80 to 170°C is even more preferable. To sufficiently promote the crosslinking reaction between the crosslinker and the adhesive, the adhesive coating liquid may be heated at 40 to 80°C for approximately 5 to 300 hours after drying is complete.

[0038] In addition, the adhesive resin layer (A) of this embodiment may be formed by co-extrusion molding together with multiple layers including the base layer (B), or may be formed by further laminating the film-like adhesive resin layer (A) on the film-like base layer (B). In the examples described later, the adhesive resin layer (A) is first formed on the surface of a separator (release film), and then the adhesive resin layer (A) is bonded to other layers to produce film 1 and an adhesive film.

[0039] [Base layer (B)] The base layer (B) is a layer provided for the purpose of improving the properties such as handleability, mechanical properties, and heat resistance of the film 1 and the pressure-sensitive adhesive film 50. The base layer (B) is not particularly limited, but examples thereof include a resin film.

[0040] The base layer (B) preferably contains a thermoplastic resin. The thermoplastic resin constituting the base layer (B) of this embodiment preferably contains 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 polymethaxylene adipamide; polyacrylates; polymethacrylates; polyvinyl chloride; polyvinylidene chloride; polyimides; polyetherimides; ethylene-vinyl acetate copolymers; polyacrylonitrile; polycarbonates; polystyrenes; ionomers; polysulfones; polyethersulfones; and polyphenylene ethers. Among these, the base layer (B) contains one or more selected from the group consisting of polyolefin, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, polyimide, and ethylene-vinyl acetate copolymer, and more preferably contains one or more selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate.

[0041] The base layer (B) may be a single layer or two or more layers. The form of the resin film used to form the base layer (B) may be a stretched film or a uniaxially or biaxially stretched film, but from the viewpoint of improving the mechanical strength of the base layer (B), a uniaxially or biaxially stretched film is preferred.

[0042] From the viewpoint of obtaining good film properties, the thickness of the substrate layer (B) is preferably 1 μm or more and 300 μm or less, more preferably 10 μm or more and 200 μm or less, and even more preferably 20 μm or more and 100 μm or less. The substrate layer (B) may be subjected to a surface treatment to improve adhesion to other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coating treatment, etc. may be performed.

[0043] [Adhesive resin layer (C)] The film 1 and the adhesive film 50 of this embodiment are provided with an adhesive resin layer (C) on the opposite side of the base layer (B) from the adhesive resin layer (A) side, the adhesive strength of which can be reduced by an external stimulus, in order to suppress misalignment of the electronic component 70.

[0044] The external stimulus preferably includes one or more selected from the group consisting of light irradiation and heat treatment, and more preferably includes heat treatment.

[0045] The adhesive resin layer (C) of this embodiment preferably contains a heat-expandable adhesive from the viewpoint of further improving releasability. The heat-expandable adhesive of this embodiment preferably contains an adhesive resin (C1) and one or more components selected from the group consisting of a gas-generating component and heat-expandable microspheres, and more preferably contains an adhesive resin (C1) and heat-expandable microspheres.

[0046] The adhesive resin layer (C) of this embodiment is a layer whose adhesive strength is reduced or lost when heated at a temperature preferably exceeding 100°C, more preferably at a temperature of 130°C or higher, even more preferably at a temperature of 150°C or higher, even more preferably at a temperature of 170°C or higher, even more preferably at a temperature of 180°C or higher, even more preferably at a temperature of 190°C or higher, even more preferably at a temperature of 200°C or higher, and even more preferably at a temperature of 210°C or higher. Such an adhesive resin layer (C) can be obtained by selecting the type of gas-generating component or heat-expandable microspheres in the adhesive resin layer (C). Here, the reduction or loss of adhesive strength when heated at a temperature exceeding 100°C can be evaluated, for example, by attaching the adhesive resin layer (C) side to a stainless steel plate, heating it at 80°C for 1 hour, and then heating it at a temperature exceeding 100°C for 2 minutes, and then measuring the peel strength from the stainless steel plate. The specific heating temperature when heating at a temperature exceeding 100°C is set to a temperature higher than the temperature at which gas is generated or the temperature at which the heat-expandable microspheres thermally expand, and is appropriately set depending on the type of gas generated and the type of heat-expandable microspheres. In this embodiment, loss of adhesive strength refers to, for example, a 180° peel strength of less than 0.5 N / 25 mm measured at 23°C and a tensile speed of 300 mm / min.

[0047] Examples of gas-generating components that can be used include azo compounds, azide compounds, Meldrum's acid derivatives, etc. Examples of gas-generating components include inorganic blowing agents such as ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium boron hydroxide, and various azides; water; fluorinated alkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate; paratoluenesulfonylhydrazide, diphenylsulfone-3,3'-disulfonylhydrazide, 4,4'-oxo-2,4'-dimethylaminobenzoate, and the like; Other examples of organic blowing agents that can be used include hydrazine compounds such as bis(benzenesulfonylhydrazide) and allylbis(sulfonylhydrazide); semicarbazide compounds such as p-toluylenesulfonylsemicarbazide and 4,4'-oxybis(benzenesulfonylsemicarbazide); triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole; and N-nitroso compounds such as N,N'-dinitrosopentamethylenetetramine and N,N'-dimethyl-N,N'-dinitrosoterephthalamide. The gas-generating component may be mixed with the adhesive resin (C1) or may be directly bonded to the adhesive resin (C1).

[0048] Heat-expandable microspheres can be prepared using, for example, microencapsulated blowing agents. Examples of such heat-expandable microspheres include microspheres in which a substance that easily gasifies and expands upon heating, such as isobutane, propane, or pentane, is encapsulated in an elastic shell. Examples of materials constituting the shell include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone. Heat-expandable microspheres can be produced by, for example, coacervation or interfacial polymerization.

[0049] From the viewpoint of further improving thermal peelability, the total content of the gas-generating component and heat-expandable microspheres in the adhesive resin layer (C) is preferably 1 to 150 parts by mass, more preferably 3 to 150 parts by mass, even more preferably 5 to 100 parts by mass, even more preferably 7 to 50 parts by mass, even more preferably 11 to 25 parts by mass, even more preferably 12 to 20 parts by mass, and even more preferably 14 to 18 parts by mass, per 100 parts by mass of the adhesive resin (C1) in the adhesive resin layer (C). It is preferable to design the temperature at which gas is generated and the temperature at which the heat-expandable microspheres thermally expand are above 100°C.

[0050] The adhesive resin (C1) of this embodiment preferably comprises one or more selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, polyester adhesive resins, polyamide adhesive resins, fluorine adhesive resins and styrene adhesive resins, and from the viewpoint of further improving the releasability, more preferably comprises one or more selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins and styrene adhesive resins, and from the viewpoint of easily adjusting the adhesive strength, more preferably comprises a (meth)acrylic adhesive resin. As the (meth)acrylic adhesive resin that can be used for the adhesive resin (C1) of this embodiment, for example, the above-mentioned (meth)acrylic adhesive resin (a) can be used.

[0051] The adhesive resin layer (C) of this embodiment preferably further contains, in addition to the adhesive resin (C1), a crosslinking agent (C2) having two or more crosslinkable functional groups per molecule. The crosslinking agent (C2) having two or more crosslinkable functional groups per molecule is reacted with the functional groups of the adhesive resin (C1) to adjust the adhesive strength and cohesive strength. The crosslinking agent (C2) of the present embodiment is preferably an epoxy-based crosslinking agent such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, or resorcinol diglycidyl ether; an isocyanate-based crosslinking agent such as tetramethylene diisocyanate, hexamethylene diisocyanate, a toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, or tolylene diisocyanate; trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'- The adhesive composition contains one or more crosslinkers selected from the group consisting of aziridine crosslinkers such as bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate; tetrafunctional epoxy crosslinkers such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine crosslinkers such as hexamethoxymethylolmelamine. From the viewpoint of further improving the performance balance between adhesive strength and releasability, the adhesive composition contains more preferably one or more crosslinkers selected from the group consisting of epoxy crosslinkers, isocyanate crosslinkers, and aziridine crosslinkers.

[0052] The content of the crosslinking agent (C2) in the adhesive resin layer (C) is preferably within a range such that the number of functional groups in the crosslinking agent (C2) is not greater than the number of functional groups in the adhesive resin (C1). However, an excess amount may be added as necessary when new functional groups are generated by the crosslinking reaction or when the crosslinking reaction is slow. From the viewpoint of further improving the performance balance of adhesive strength, peelability, and storage stability, the content of the crosslinking agent (C2) in the adhesive resin layer (C) is preferably 0.1 parts by mass or more and 10.0 parts by mass or less, more preferably 0.5 parts by mass or more and 8.0 parts by mass or less, even more preferably 1.0 parts by mass or more and 6.0 parts by mass or less, and even more preferably 2.0 parts by mass or more and 4.0 parts by mass or less, per 100 parts by mass of the adhesive resin (C1).

[0053] The adhesive resin layer (C) of this embodiment preferably contains a tackifier resin in addition to the adhesive resin (C1) from the viewpoint of further improving adhesive strength. By including a tackifier resin in the adhesive resin layer (C), it becomes easier to adjust the adhesion to the support substrate at around room temperature. The tackifier resin preferably has a softening point of 100°C or higher. Specific examples of tackifier resins include rosin-based resins such as rosin derivatives treated by esterification or the like; terpene-based resins such as α-pinene, β-pinene, dipentene, and terpene phenol; natural rosins such as gum, wood, and tall oil; petroleum resins obtained by hydrogenating, disproportionating, polymerizing, or maleating these natural rosins; and coumarone-indene resins. The adhesive resin layer (C) of this embodiment preferably contains a tackifier resin having a softening point in the range of 100 to 160°C, more preferably in the range of 120 to 150°C.

[0054] From the viewpoint of further improving adhesion to the support substrate during operation, the content of the tackifier resin in the adhesive resin layer (C) is preferably 1 part by mass or more and 100 parts by mass or less, more preferably 2 parts by mass or more and 50 parts by mass or less, even more preferably 3 parts by mass or more and 30 parts by mass or less, and even more preferably 5 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the adhesive resin (C1).

[0055] The adhesive resin layer (C) may contain additives such as plasticizers as other components. The total content of the adhesive resin (C1), crosslinking agent (C2), tackifier resin, gas-generating component, and heat-expandable microspheres in the adhesive resin layer (C) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on 100% by mass of the entire adhesive resin layer (C). The upper limit is not particularly limited, but is, for example, 100% by mass or less.

[0056] The adhesive resin layer (C) may be a single layer or a multilayer. The thickness of the adhesive resin layer (C) is preferably 10 μm or more and 100 μm or less, more preferably 15 μm or more and 90 μm or less, even more preferably 20 μm or more and 80 μm or less, and still more preferably 25 μm or more and 70 μm or less, from the viewpoint of further improving the balance of the handling properties, adhesiveness, and peelability of the film 1 and the adhesive film 50.

[0057] [Substrate layer (D)] The substrate layer (D) is a layer provided for the purpose of improving the properties such as the handleability, mechanical properties, and heat resistance of the film 2 and the pressure-sensitive adhesive film 50. The substrate layer (D) is not particularly limited, but examples thereof include a resin film.

[0058] The base layer (D) preferably contains a thermoplastic resin. The thermoplastic resin constituting the base layer (D) of this embodiment preferably contains 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 polymethaxylene adipamide; polyacrylates; polymethacrylates; polyvinyl chloride; polyvinylidene chloride; polyimides; polyetherimides; ethylene-vinyl acetate copolymers; polyacrylonitrile; polycarbonates; polystyrenes; ionomers; polysulfones; polyethersulfones; and polyphenylene ethers. Among these, from the viewpoint of achieving an excellent balance between transparency, mechanical strength, price, and the like, the base layer (D) preferably contains one or more selected from the group consisting of polyolefin, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, polyimide, and ethylene-vinyl acetate copolymer, and more preferably contains one or more selected from polyethylene terephthalate and polyethylene naphthalate.

[0059] The base layer (D) may be a single layer or two or more layers. The form of the resin film used to form the base layer (D) may be a stretched film or a uniaxially or biaxially stretched film, but from the viewpoint of improving the mechanical strength of the base layer (D), a uniaxially or biaxially stretched film is preferred.

[0060] From the viewpoint of obtaining good film properties, the thickness of the substrate layer (D) is preferably 1 μm or more and 300 μm or less, more preferably 10 μm or more and 200 μm or less, and even more preferably 20 μm or more and 100 μm or less. The substrate layer (D) may be subjected to a surface treatment to improve adhesion to other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coating treatment, etc. may be performed.

[0061] [Adhesive Resin Layer (E)] The film 2 and the adhesive film 50 of the present embodiment are provided with an adhesive resin layer (E) on one surface of the base layer (D) from the viewpoint of suppressing misalignment of the electronic component 70. The adhesive resin layer (E) is a layer that comes into contact with the surface of an electronic component or a supporting substrate to temporarily fix the electronic component or the supporting substrate, for example, when sealing the electronic component with a sealing material in the manufacturing process of an electronic device.

[0062] The adhesive resin layer (E) preferably contains an adhesive resin (Ea). The adhesive resin (Ea) preferably contains one or more selected from (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins. Among these, the adhesive resin (Ea) preferably contains a (meth)acrylic adhesive resin from the viewpoint of suppressing misalignment of the electronic component 70 and improving the performance balance of adhesive strength. As the (meth)acrylic adhesive resin that can be used for the adhesive resin (Ea) of this embodiment, for example, the above-mentioned (meth)acrylic adhesive resin (a) can be used.

[0063] The adhesive resin layer (E) may be a radiation-crosslinkable adhesive resin layer whose adhesive strength can be reduced by radiation. When the radiation-crosslinkable adhesive resin layer is irradiated with radiation, crosslinking occurs, significantly reducing the adhesive strength, making it easier to peel the adhesive film 50 from the electronic component. Examples of radiation include ultraviolet light, electron beams, and infrared light. The radiation-crosslinkable adhesive resin layer preferably includes an ultraviolet-crosslinkable adhesive resin layer.

[0064] The adhesive resin layer (E) of this embodiment preferably further contains, in addition to the adhesive resin (Ea), a crosslinking agent (Eb) having two or more crosslinkable functional groups per molecule, from the viewpoint of suppressing misalignment of the electronic component 70 and improving the performance balance of adhesive strength. The crosslinking agent (Eb) having two or more crosslinkable functional groups per molecule can be reacted with the functional groups of the adhesive resin (Ea) and used to adjust the adhesive strength and cohesive strength. The crosslinking agent (Eb) of the present embodiment is preferably an epoxy-based crosslinking agent such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, or resorcinol diglycidyl ether; an isocyanate-based crosslinking agent such as tetramethylene diisocyanate, hexamethylene diisocyanate, a toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, or tolylene diisocyanate; trimethylolpropane-tri-β-aziridinyl propionate, tetramethylolpropane-tri-β-aziridinyl propionate, or tetramethylolpropane-tri-β-aziridinyl propionate; The crosslinking agent may comprise one or more crosslinkers selected from the group consisting of aziridine-based crosslinkers such as tyrolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate; tetrafunctional epoxy-based crosslinkers such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine-based crosslinkers such as hexamethoxymethylolmelamine. Among these, the crosslinking agent (Eb) of this embodiment preferably includes one or more crosslinking agents selected from the group consisting of epoxy-based crosslinking agents, isocyanate-based crosslinking agents, and aziridine-based crosslinking agents, from the viewpoint of being able to improve the performance balance between suppressing misalignment of the electronic component 70 and adhesive strength.

[0065] The content of the crosslinking agent (Eb) is preferably within a range such that the number of functional groups in the crosslinking agent (Eb) is not greater than the number of functional groups in the adhesive resin (Ea). However, an excess amount of the crosslinking agent (Eb) may be added as necessary when new functional groups are generated by the crosslinking reaction or when the crosslinking reaction is slow. The content of the crosslinking agent (Eb) in the adhesive resin layer (E) is preferably 0.1 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the adhesive resin (Ea), from the viewpoint of suppressing misalignment of the electronic component 70 in the adhesive resin layer (E) and improving the performance balance between heat resistance and adhesion.

[0066] The adhesive resin layer (E) may contain additives such as plasticizers and tackifier resins as other components. When the adhesive resin layer (E) is a radiation-crosslinkable adhesive resin layer, it may contain various additives for radiation crosslinking. The total content of the adhesive resin (Ea) and the crosslinking agent (Eb) in the adhesive resin layer (E) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on 100% by mass of the entire adhesive resin layer (E), from the viewpoint of suppressing misalignment of the electronic component 70. The upper limit of the total content of the adhesive resin (Ea) and the crosslinking agent (Eb) in the adhesive resin layer (E) is not particularly limited, but may be, for example, 100% by mass or less.

[0067] In the pressure-sensitive adhesive film 50 of the present embodiment, from the viewpoint of being able to stably hold the electronic component 70 when the support substrate is peeled off from the pressure-sensitive adhesive film 50, the total content of the gas-generating component and heat-expandable microspheres in the pressure-sensitive adhesive resin layer (E) is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, even more preferably 0.01% by mass or less, based on 100% by mass of the entire pressure-sensitive adhesive resin layer (E). More preferably, the pressure-sensitive adhesive resin layer (E) does not contain any gas-generating component or heat-expandable microspheres.

[0068] The adhesive resin layer (E) may be a single layer or a multilayer. The thickness of the adhesive resin layer (E) is preferably 1 μm or more and 40 μm or less, more preferably 3 μm or more and 35 μm or less, and even more preferably 5 μm or more and 30 μm or less.

[0069] The adhesive resin layer (E) can be formed, for example, by applying an adhesive onto the substrate layer (D). The adhesive may be dissolved in a solvent and applied as a coating liquid, or may be applied as an aqueous emulsion, or the liquid adhesive may be directly applied. Among these, the adhesive is preferably an aqueous emulsion coating liquid. Examples of aqueous emulsion coating liquids include coating liquids in which a (meth)acrylic adhesive resin, a silicone adhesive resin, a urethane adhesive resin, an olefin adhesive resin, a styrene adhesive resin, or the like is dispersed in water. An adhesive coating liquid dissolved in an organic solvent may also be used. The organic solvent is not particularly limited, and may be appropriately selected from known organic solvents in consideration of solubility and drying time. The organic solvent of the present embodiment preferably includes one or more selected from the group consisting of 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 solvents such as heptane, hexane, and cyclohexane; and alcohols such as isopropanol and butanol, and more preferably includes one or two selected from the group consisting of ethyl acetate and toluene.

[0070] The adhesive coating liquid can be applied using conventional coating methods such as a roll coater method, a reverse roll coater method, a gravure roll method, a bar coater method, a comma coater method, or a die coater method. The drying conditions for the applied adhesive are not particularly limited, but generally, drying is preferably performed for 10 seconds to 10 minutes at a temperature range of 80 to 200°C. Drying for 15 seconds to 5 minutes at 80 to 170°C is even more preferable. To sufficiently promote the crosslinking reaction between the crosslinker and the adhesive, the adhesive coating liquid may be heated at 40 to 80°C for approximately 5 to 300 hours after drying is complete.

[0071] In addition, the adhesive resin layer (E) of this embodiment may be formed by co-extrusion molding together with multiple layers including the base layer (D), or may be formed by further laminating the film-like adhesive resin layer (E) on the film-like base layer (D). In the examples described later, the adhesive resin layer (E) is first formed on the surface of a separator (release film), and then the adhesive resin layer (E) is bonded to other layers to produce the film 2 and the adhesive film.

[0072] [Intermediate layer (F)] The pressure-sensitive adhesive film 50 of the present embodiment further includes an intermediate layer (F) between at least one layer selected from the group consisting of the adhesive resin layer (A) and the base layer (B), the base layer (B) and the adhesive resin layer (C), and the base layer (D) and the adhesive resin layer (E), from the viewpoint of being able to suppress misalignment of the electronic component 70 and to improve the performance balance of the conformability and adhesion of the pressure-sensitive adhesive film 50 to the electronic component and the supporting substrate. The intermediate layer (F) of the present embodiment is, for example, a layer for imparting conformability and adhesion to the electronic component and the supporting substrate to the pressure-sensitive adhesive film 50.

[0073] The intermediate layer (F) of this embodiment preferably contains a thermoplastic resin (F1). The thermoplastic resin (F1) of this embodiment preferably contains one or more selected from the group consisting of polyolefin resins, ethylene-carboxylic anhydride copolymers, ethylene-epoxy copolymers, ethylene-(meth)acrylic acid ester copolymers, ethylene-ethylenically unsaturated acid copolymers, ethylene-vinyl ester copolymers, polystyrene resins, and (meth)acrylic resins, and more preferably contains a (meth)acrylic resin from the viewpoint of further improving releasability. Examples of the (meth)acrylic resin that can be used for the thermoplastic resin (F1) of this embodiment include the (meth)acrylic adhesive resin (a) described above.

[0074] The intermediate layer (F) of this embodiment preferably further contains, in addition to the thermoplastic resin (F1), a crosslinking agent (F2) having two or more crosslinkable functional groups per molecule. The crosslinking agent (F2) having two or more crosslinkable functional groups per molecule is reacted with the functional groups of the thermoplastic resin (F1) to adjust the adhesive strength and cohesive strength. The crosslinking agent (F2) of the present embodiment is preferably an epoxy-based crosslinking agent such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, or resorcinol diglycidyl ether; an isocyanate-based crosslinking agent such as tetramethylene diisocyanate, hexamethylene diisocyanate, a toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, or tolylene diisocyanate; trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'- The adhesive composition contains one or more crosslinkers selected from the group consisting of aziridine crosslinkers such as bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate; tetrafunctional epoxy crosslinkers such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine crosslinkers such as hexamethoxymethylolmelamine. From the viewpoint of further improving the performance balance between adhesive strength and releasability, the adhesive composition contains more preferably one or more crosslinkers selected from the group consisting of epoxy crosslinkers, isocyanate crosslinkers, and aziridine crosslinkers.

[0075] The content of the crosslinking agent (F2) in the intermediate layer (F) of this embodiment is preferably within a range such that the number of functional groups in the crosslinking agent (F2) is not greater than the number of functional groups in the thermoplastic resin (F1). However, an excess amount may be added as necessary when new functional groups are generated in the crosslinking reaction or when the crosslinking reaction is slow. From the viewpoint of further improving the performance balance of adhesive strength, peelability, and storage stability, the content of the crosslinking agent (F2) in the intermediate layer (F) of this embodiment is preferably 0.1 parts by mass or more and 10.0 parts by mass or less, more preferably 0.5 parts by mass or more and 8.0 parts by mass or less, even more preferably 1.0 parts by mass or more and 6.0 parts by mass or less, and even more preferably 2.0 parts by mass or more and 4.0 parts by mass or less, per 100 parts by mass of the thermoplastic resin (F1).

[0076] The intermediate layer (F) of this embodiment preferably contains a tackifier resin in addition to the thermoplastic resin (F1) from the viewpoint of further improving adhesive strength. By incorporating a tackifier resin into the intermediate layer (F), it becomes easier to adjust the adhesion to the support substrate at around room temperature. The tackifier resin preferably has a softening point of 100°C or higher. Specific examples of tackifier resins include rosin-based resins such as rosin derivatives treated by esterification or the like; terpene-based resins such as α-pinene, β-pinene, dipentene, and terpene phenol; natural rosins such as gum, wood, and tall oil; petroleum resins obtained by hydrogenating, disproportionating, polymerizing, or maleating these natural rosins; and coumarone-indene resins. Among these tackifier resins, the intermediate layer (F) of this embodiment preferably contains a tackifier resin having a softening point in the range of 100 to 160°C, more preferably in the range of 120 to 150°C.

[0077] In order to further improve adhesion to the support substrate during operation, the content of the tackifier resin in the intermediate layer (F) of this embodiment is preferably 1 part by mass or more and 100 parts by mass or less, more preferably 2 parts by mass or more and 50 parts by mass or less, even more preferably 3 parts by mass or more and 30 parts by mass or less, and even more preferably 3 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin (F1).

[0078] The intermediate layer (F) of this embodiment may contain additives such as plasticizers as other components. The total content of the thermoplastic resin (F1), crosslinking agent (F2), tackifier resin, gas-generating component, and heat-expandable microspheres in the intermediate layer (F) of this embodiment is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on 100% by mass of the entire intermediate layer (F). The upper limit is not particularly limited, but is, for example, 100% by mass or less.

[0079] The thickness of the intermediate layer (F) in this embodiment is preferably 1 μm or more and 400 μm or less, more preferably 5 μm or more and 300 μm or less, and even more preferably 10 μm or more and 100 μm or less, from the viewpoint of improving the unevenness absorbency of the adhesive film 50.

[0080] [Other Layers] The pressure-sensitive adhesive film 50 of this embodiment may further include, for example, an easy-adhesion layer or the like between the layers, as long as the effect of this embodiment is not impaired.

[0081] [Use] The pressure-sensitive adhesive film 50 of the present embodiment can preferably temporarily fix the electronic component 70 when sealing the electronic component 70 with a sealing material. In this case, the electronic component 70 preferably has an uneven structure.

[0082] Here, the uneven structure of the electronic component preferably includes a bump electrode. When the uneven structure of the electronic component includes a bump electrode, when the height of the bump electrode is H [μm] and the thickness of the adhesive resin layer (A) is d [μm], H / d is preferably 1 or less, more preferably 0.85 or less, and even more preferably 0.7 or less. When H / d is equal to or less than the above upper limit, the thickness of the adhesive film 50 can be made thinner while improving the unevenness absorbency. The lower limit of H / d is not particularly limited, but is, for example, 0.01 or more. The height of the bump electrode is generally 2 μm or more and 600 μm or less.

[0083] The adhesive film 50 of the present embodiment is preferably a backgrinding tape. That is, the adhesive film 50 of the present embodiment can be preferably used in a step of backgrinding the electronic component 70 temporarily fixed to the adhesive film 50.

[0084] <Method for manufacturing electronic device> Hereinafter, a method for manufacturing an electronic device of this embodiment will be described. In one aspect of this embodiment, the method for manufacturing an electronic device of this embodiment preferably includes, in this order, a step of preparing a structure 100 including a support substrate 80 on one side of an adhesive film 50 and an electronic component 70 on the other side of the adhesive film 50, as shown in Fig. 3 , and a step of reducing the adhesive force of the adhesive resin layer (C) by an external stimulus, and peeling the adhesive resin layer (C) from the base material layer (D).

[0085] First, a structure 100 is prepared, which includes a support substrate 80 on one side of an adhesive film 50 and an electronic component 70 on the other side of the adhesive film 50. The structure 100 in the method for manufacturing an electronic device of this embodiment can be produced, for example, by the following procedure. First, one side of the adhesive film 50 and the support substrate 80 are attached to the support substrate 80. A protective film called a separator may be attached to the adhesive film 50, and the protective film can be peeled off to attach the exposed surface of the adhesive film 50 to the surface of the support substrate. Next, the structure 100 can be obtained by placing the electronic component 70 on the side of the adhesive film 50 opposite to the side to which the support substrate 80 is attached.

[0086] Furthermore, from the viewpoint of manufacturing efficiency, the step of preparing the structure 100 in the manufacturing method of the electronic device of the present embodiment preferably includes a step of bonding the adhesive resin layer (C) and the base material layer (D) together, and a step of bonding one surface of the adhesive film 50 to the support substrate 80. In this case, the order of the two steps is not particularly limited. That is, the adhesive resin layer (A) of film 1 constituting the adhesive film 50 may be bonded to the support substrate 80, and then the adhesive resin layer (C) of film 1 and the base layer (D) of film 2 may be bonded together; the adhesive resin layer (E) of film 2 constituting the adhesive film 50 may be bonded to the support substrate 80, and then the adhesive resin layer (C) of film 1 and the base layer (D) of film 2 may be bonded together; the adhesive resin layer (C) of film 1 and the base layer (D) of film 2 may be bonded together, and then the adhesive resin layer (A) side of the adhesive film 50 may be bonded to the support substrate 80; or the adhesive resin layer (C) of film 1 and the base layer (D) of film 2 may be bonded together, and then the adhesive resin layer (E) side of the adhesive film 50 may be bonded to the support substrate 80.

[0087] The support substrate 80 may be, for example, a quartz substrate, a glass substrate, or a SUS substrate.

[0088] Examples of the electronic component 70 to be attached to the adhesive film 50 include semiconductor chips such as ICs, LSIs, discrete devices, light-emitting diodes, and light-receiving elements, semiconductor panels, and semiconductor packages.

[0089] The surface of the electronic component 70 may have an uneven structure, for example, by having electrodes. Furthermore, for example, when mounting an electronic device on a mounting surface, the electrodes are bonded to the electrodes formed on the mounting surface to form an electrical connection between the electronic device and the mounting surface (such as the mounting surface of a printed circuit board). Examples of the electrodes include bump electrodes such as ball bumps, printed bumps, stud bumps, plated bumps, and pillar bumps. That is, the electrodes are typically convex electrodes. These bump electrodes may be used alone or in combination of two or more types. Furthermore, the metal species constituting the bump electrodes are not particularly limited, and examples include silver, gold, copper, tin, lead, bismuth, and alloys thereof. These metal species may be used alone or in combination of two or more types.

[0090] Next, the adhesive strength of the adhesive resin layer (C) is reduced by an external stimulus, and the adhesive resin layer (C) is peeled off from the base layer (D). The method of reducing the adhesive strength of the adhesive resin layer (C) and then peeling it off preferably includes a method of subjecting the adhesive film 50 to one or more treatments selected from the group consisting of light irradiation and heat treatment.

[0091] When the adhesive resin layer (C) is subjected to light irradiation treatment, the light source used preferably includes a light source capable of irradiating ultraviolet light containing a wavelength component capable of exciting the photoinitiator, and more preferably includes a light source capable of irradiating ultraviolet light containing a component with a wavelength of less than 300 nm. Examples of such light sources include high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, and super UV lamps. The light irradiated by the above light sources may contain a component with a wavelength of 300 nm or more. In the case of ultraviolet crosslinking, for example, ultraviolet light with a dominant wavelength of 365 nm is irradiated using a high-pressure mercury lamp at an irradiation intensity of 10 to 350 mW / cm in an environment of 0 to 60°C. ２ UV dose 100-20,000 mJ / cm ２ By irradiating the adhesive film 50 under the above conditions, the adhesive strength of the adhesive resin layer (C) can be reduced.

[0092] When the pressure-sensitive adhesive resin layer (C) is subjected to heat treatment, the heating method preferably includes heating in an oven, heating on a hot plate, heating by infrared irradiation, etc. In the above heating methods, the heating temperature may be higher than the temperature at which gas is generated or the temperature at which the heat-expandable microspheres thermally expand, and is, for example, 100° C. or higher and 300° C. or lower, and the heat treatment time is, for example, 10 minutes or higher and 180 minutes or lower.

[0093] In one aspect of the method for producing an electronic device according to the present embodiment, as shown in FIG. 4 , the method preferably further includes a step of peeling the adhesive film 50 from the electronic component 70 after a step of reducing the adhesive strength of the adhesive resin layer (C) by an external stimulus to peel the adhesive resin layer (C) from the base layer (D). This step results in an electronic device 200. In this step, "peeling the adhesive film 50 from the electronic component 70" is synonymous with peeling film 1 in the adhesive film 50 from the electronic component 70 when the electronic component 70 is attached to the adhesive resin layer (A), and is synonymous with peeling film 2 in the adhesive film 50 from the electronic component 70 when the electronic component 70 is attached to the adhesive resin layer (E). Examples of methods for peeling the adhesive film 50 from the electronic component 70 include a mechanical peeling method and a method of peeling after reducing the adhesive strength of the surface of the adhesive film 50, i.e., the adhesive resin layer (A) or the adhesive resin layer (E).

[0094] The method for reducing the adhesive strength of the surface of the adhesive film 50 before peeling it off preferably includes a method of subjecting the adhesive film 50 to one or more treatments selected from the group consisting of light irradiation and heat treatment.

[0095] When the PSA film 50 is subjected to light irradiation treatment, the light source used preferably includes a light source capable of irradiating ultraviolet light containing a wavelength component capable of exciting the photoinitiator, and more preferably includes a light source capable of irradiating ultraviolet light containing a component with a wavelength of less than 300 nm. Examples of such light sources include high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, and super UV lamps. The light irradiated by the above light sources may contain a component with a wavelength of 300 nm or more. In the case of ultraviolet crosslinking, for example, ultraviolet light with a dominant wavelength of 365 nm is irradiated using a high-pressure mercury lamp in an environment of 0 to 60°C, with an irradiation intensity of 10 to 350 mW / cm. ２ UV dose 100-20,000 mJ / cm ２ By irradiating the adhesive film 50 under the above conditions, the adhesive strength of the surface of the adhesive film 50 can be reduced.

[0096] When the pressure-sensitive adhesive film 50 is subjected to heat treatment, the heating method preferably includes heating in an oven, heating on a hot plate, heating by infrared irradiation, etc. In the above heating methods, the heating temperature is, for example, 50° C. or more and 300° C. or less, and the heat treatment time is, for example, 10 minutes or more and 180 minutes or less.

[0097] 4 , the method for manufacturing an electronic device according to the present embodiment preferably further includes a step of encapsulating electronic components 70 with a sealant 60 between the step of preparing the structure 100 and the step of peeling the adhesive resin layer (C) and the base layer (D) from each other. In the step of encapsulating electronic components 70 with a sealant 60, the electronic components 70 are encapsulated by covering them with the sealant 60. Here, when the adhesive resin layer (C) of the adhesive film 50 contains at least one selected from a gas-generating component and heat-expandable microspheres, the temperature at which the sealant 60 is used for encapsulation is preferably within a range not exceeding the temperature at which gas is generated or the temperature at which the heat-expandable microspheres thermally expand.

[0098] In the step of sealing the electronic components 70 with the sealing material 60, the plurality of electronic components 70 may be sealed collectively or individually with the sealing material 60. The method for individually covering the plurality of electronic components 70 with the sealing material 60 preferably includes one or more methods selected from the group consisting of a 3D printer method, a spray method, a screen printing method, and an inkjet method, and more preferably includes a 3D printer method.

[0099] As the sealing material 60, any known sealing material with high insulating properties can be used. However, in order to improve the affinity of the sealing material 60 to the adhesive film 50 and enable more uniform sealing of the electronic component 70, the sealing material 60 preferably includes one or more types selected from the group consisting of epoxy resin-based sealing materials and silicone resin-based sealing materials. Examples of such epoxy resin-based sealing materials that can be used include the T693 / R4000 series, T693 / R1000 series, and T693 / R5000 series manufactured by Nagase ChemteX Corporation. Examples of such silicone resin-based sealing materials that can be used include KMC-8400 manufactured by Shin-Etsu Chemical Co., Ltd., and TSE3033 and TSE3251 manufactured by Momentive Performance Materials Japan, Inc. The sealing material 60 may be in either a solid or liquid form. However, a liquid form is preferred from the viewpoints that the sealing process can be performed at low temperature and low pressure and that displacement of the electronic component 70 during the sealing process can be further suppressed.

[0100] The method for manufacturing an electronic device according to the present embodiment preferably further includes, between the step of sealing the electronic component 70 with the sealing material 60 and the step of peeling the adhesive resin layer (C) from the base layer (D), a step of curing the sealing material 60 by treating it with one or two methods selected from the group consisting of light irradiation and heat treatment. This fixes the electronic component 70 and further suppresses misalignment of the electronic component 70.

[0101] The method of curing the encapsulant 60 by light irradiation is preferably a method of crosslinking and curing the encapsulant 60 by irradiating the encapsulant 60 with light such as ultraviolet light. The light source used in this method is preferably a light source capable of irradiating ultraviolet light containing wavelength components capable of exciting a photoinitiator, and more preferably a light source capable of irradiating ultraviolet light containing components with wavelengths of less than 300 nm. The method of curing the encapsulant 60 by heat treatment is preferably a method of curing the encapsulant 60 by thermal crosslinking using an oven, thermal crosslinking using a hot plate, or thermal crosslinking using infrared radiation. In the case of thermal crosslinking, the heating temperature is, for example, 50°C or higher and 100°C or lower, and the heating treatment time is, for example, 10 minutes or higher and 180 minutes or lower. The heating temperature is preferably a temperature that does not exceed the temperature at which gas contained in the pressure-sensitive adhesive film 50 is generated or the temperature at which the heat-expandable microspheres thermally expand.

[0102] The method for manufacturing an electronic device according to this embodiment can be preferably used to manufacture an electronic device including a fan-out package. That is, the electronic device obtained by the method for manufacturing an electronic device according to this embodiment includes a fan-out package. In a fan-out package, terminals can be extended to the outside of the chip (fan out), so it can be used in applications where the number of terminals is large compared to the chip area. Furthermore, since a package substrate is not required, it can also be made thinner.

[0103] In one aspect of this embodiment, the method for manufacturing an electronic device of this embodiment preferably includes, in this order, a step of preparing a structure 100 having electronic components 70 on one side of an adhesive film 50, and a step of back-grinding the electronic components 70, as shown in FIG.

[0104] First, a structure 100 is prepared, which includes an electronic component 70 on one surface of an adhesive film 50. Such a structure 100 can be produced, for example, by attaching one surface of the adhesive film 50 to the electronic component 70.

[0105] The operation of attaching the adhesive film 50 to the electronic component 70 may be performed manually, but generally, it can be performed using a device called an automatic attachment machine equipped with a roll of adhesive film. The conditions for attaching the adhesive film 50 to the electronic component 70 are not particularly limited, but can be, for example, a temperature of 20 to 80°C, a pressure of 0.05 to 0.5 MPa, and an attachment speed of 0.5 to 20 mm / sec.

[0106] Examples of the electronic component 70 to which the adhesive film 50 is attached include semiconductor chips such as ICs, LSIs, discretes, light-emitting diodes, and light-receiving elements, semiconductor panels, semiconductor packages, semiconductor wafers, molded wafers, molded panels, molded array packages, and semiconductor substrates, and preferably includes one or more types selected from the group consisting of semiconductor wafers and molded wafers, and more preferably includes a semiconductor wafer.

[0107] The semiconductor wafer in one aspect of the method for manufacturing an electronic device of this embodiment is preferably a silicon wafer, a sapphire wafer, an indium-phosphorus wafer, a silicon-carbon wafer, a gallium-nitrogen wafer, a gallium-oxygen wafer, a gallium-arsenic wafer, a silicon wafer, a germanium wafer, a germanium-arsenic wafer, a gallium-phosphorus wafer, a gallium-arsenic-aluminum wafer, an indium-gallium-nitrogen wafer, a gallium-arsenic-phosphorus wafer, a glass wafer, or a lithium tantalate wafer. The mold wafer in one aspect of the method for manufacturing an electronic device of this embodiment preferably includes a wafer manufactured by an eWLB (Embedded Wafer Level Ball Grid Array) process, which is one of the manufacturing methods for fan-out type WLP.

[0108] In one aspect of the method for manufacturing an electronic device according to the present embodiment, the electronic component 70 preferably includes a circuit-forming surface. The electronic component 70 including the circuit-forming surface is not particularly limited, and examples thereof include electronic components having circuits such as wiring, capacitors, diodes, or transistors formed on the surface. Furthermore, the circuit-forming surface may be plasma-treated.

[0109] The circuit-forming surface of the electronic component 70 may be uneven, for example, by having bump electrodes or the like. The bump electrodes are bonded to electrodes formed on the mounting surface when mounting an electronic device on the mounting surface, forming an electrical connection between the electronic device and the mounting surface (such as the mounting surface of a printed circuit board). Examples of bump electrodes include ball bumps, printed bumps, stud bumps, plated bumps, and pillar bumps. In other words, bump electrodes are typically convex electrodes. These bump electrodes may be used alone or in combination of two or more types. The height and diameter of the bump electrodes are not particularly limited, but are preferably 10 to 400 μm, more preferably 50 to 300 μm, respectively. The bump pitch is also not particularly limited, but is preferably 20 to 600 μm, more preferably 100 to 500 μm. The metal species constituting the bump electrode is not particularly limited, and examples thereof include solder, silver, gold, copper, tin, lead, bismuth, and alloys thereof, but the adhesive film 50 is suitably used when the bump electrode is a solder bump. These metal species may be used alone or in combination of two or more.

[0110] In one aspect of the method for manufacturing an electronic device according to the present embodiment, from the viewpoint of protecting the circuit-forming surface of the electronic component 70, an adhesive film 50 is preferably attached to the circuit-forming surface of the electronic component 70.

[0111] Next, the electronic component 70 is back-ground. "Back-grinding" means thinning the electronic component 70 to a predetermined thickness without damaging it. For example, the structure 100 is fixed to a chuck table or the like of a grinding machine, and the surface of the electronic component 70 opposite the circuit-forming surface (also referred to as the back surface or non-circuit-forming surface) is ground.

[0112] In the process of back-grinding electronic component 70, electronic component 70 is ground until its thickness is equal to or less than a desired thickness. The thickness of electronic component 70 before grinding is determined appropriately depending on the diameter, type, etc. of electronic component 70, and the thickness of electronic component 70 after grinding is determined appropriately depending on the size, type of circuit, etc. of the electronic device 200 to be obtained. Furthermore, if electronic component 70 is half-cut or a modified layer is formed by laser irradiation, electronic component 70 can be singulated into individual chips.

[0113] The method for backgrinding the electronic component 70 is not particularly limited, and known grinding methods can be employed. Grinding can be performed by pouring water over the electronic component 70 and the grindstone to cool it. If necessary, a dry polishing process, which is a grinding method that does not use grinding water, can be performed at the end of the backgrinding process of the electronic component 70. After grinding, chemical etching can be performed as needed. Chemical etching can be performed by immersing the electronic component 70 with the adhesive film 50 attached in an etching solution selected from the group consisting of an acidic aqueous solution containing, alone or in combination, hydrofluoric acid, nitric acid, sulfuric acid, acetic acid, etc., and an alkaline aqueous solution such as potassium hydroxide aqueous solution or sodium hydroxide aqueous solution. Etching is performed for the purposes of removing distortion on the back surface of the electronic component 70, further thinning the electronic component 70, removing oxide films, etc., and pretreatment for forming electrodes on the back surface. The etching solution is appropriately selected depending on the purpose.

[0114] In one aspect of the method for producing an electronic device of the present embodiment, as shown in Fig. 6, the method preferably further includes a step of reducing the adhesive strength of the adhesive resin layer (C) by an external stimulus, and then peeling the adhesive resin layer (C) from the base material layer (D). This step can further improve the releasability between the electronic component 70 and the adhesive film 50. The method for reducing the adhesive strength of the adhesive resin layer (C) and then peeling the adhesive film 50 preferably includes a method of subjecting the adhesive film 50 to one or more treatments selected from the group consisting of light irradiation and heat treatment.

[0115] When the adhesive resin layer (C) is subjected to light irradiation treatment, the light source used preferably includes a light source capable of irradiating ultraviolet light containing a wavelength component capable of exciting the photoinitiator, and more preferably includes a light source capable of irradiating ultraviolet light containing a component with a wavelength of less than 300 nm. Examples of such light sources include high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, and super UV lamps. The light irradiated by the above light sources may contain a component with a wavelength of 300 nm or more. In the case of ultraviolet crosslinking, for example, ultraviolet light with a dominant wavelength of 365 nm is irradiated using a high-pressure mercury lamp at an irradiation intensity of 10 to 350 mW / cm in an environment of 0 to 60°C. ２ UV dose 100-20,000 mJ / cm ２ By irradiating the adhesive film 50 under the above conditions, the adhesive strength of the adhesive resin layer (C) can be reduced.

[0116] When the pressure-sensitive adhesive resin layer (C) is subjected to heat treatment, the heating method preferably includes heating in an oven, heating on a hot plate, heating by infrared irradiation, etc. In the above heating methods, the heating temperature may be higher than the temperature at which gas is generated or the temperature at which the heat-expandable microspheres thermally expand, and is, for example, 100° C. or higher and 300° C. or lower, and the heat treatment time is, for example, 10 minutes or higher and 180 minutes or lower.

[0117] 6, one aspect of the method for producing an electronic device according to the present embodiment preferably further includes a step of peeling the adhesive film 50 from the electronic component 70. This step results in the electronic device 200. Examples of methods for peeling the adhesive film 50 from the electronic component 70 include a mechanical peeling method and a method of reducing the adhesive strength of the surface of the adhesive film 50 before peeling.

[0118] The method for reducing the adhesive strength of the surface of the adhesive film 50 before peeling it off preferably includes a method of subjecting the adhesive film 50 to one or more treatments selected from the group consisting of light irradiation and heat treatment.

[0119] When the PSA film 50 is subjected to light irradiation treatment, the light source used preferably includes a light source capable of irradiating ultraviolet light containing a wavelength component capable of exciting the photoinitiator, and more preferably includes a light source capable of irradiating ultraviolet light containing a component with a wavelength of less than 300 nm. Examples of such light sources include high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, and super UV lamps. The light irradiated by the above light sources may contain a component with a wavelength of 300 nm or more. In the case of ultraviolet crosslinking, for example, ultraviolet light with a dominant wavelength of 365 nm is irradiated using a high-pressure mercury lamp in an environment of 0 to 60°C, with an irradiation intensity of 10 to 350 mW / cm. ２ UV dose 100-20,000 mJ / cm ２ By irradiating the adhesive film 50 under the above conditions, the adhesive strength of the surface of the adhesive film 50 can be reduced.

[0120] When the pressure-sensitive adhesive film 50 is subjected to heat treatment, the heating method preferably includes heating in an oven, heating on a hot plate, heating by infrared irradiation, etc. In the above heating methods, the heating temperature is, for example, 50° C. or more and 300° C. or less, and the heat treatment time is, for example, 10 minutes or more and 180 minutes or less.

[0121] Before removing the adhesive film 50 from the electronic component 70, the electronic component 70 may be mounted on a dicing tape or a dicing tape with a die attach film together with a ring frame. The operation of removing the adhesive film 50 from the electronic component 70 may be performed manually, but can generally be performed by a device called an automatic peeler.

[0122] The surface of the electronic component 70 after peeling off the adhesive film 50 may be cleaned as needed. Examples of cleaning methods include wet cleaning such as water cleaning and solvent cleaning, and dry cleaning such as plasma cleaning. In the case of wet cleaning, ultrasonic cleaning may be used in combination. The cleaning method can be appropriately selected depending on the degree of contamination on the surface of the electronic component 70.

[0123] In one aspect of the method for manufacturing an electronic device according to the present embodiment, after the above steps are performed, a step of mounting the obtained electronic device 200 on a circuit board may be further performed. These steps can be performed based on publicly known information.

[0124] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted.

[0125] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0126] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Details of the method for producing the adhesive film are as follows.

[0127] <Raw Material Components> (Resin Emulsion 1) Using 0.5 parts by mass of ammonium peroxodisulfate as a polymerization initiator, 63 parts by mass of 2-ethylhexyl acrylate, 21 parts by mass of butyl acrylate, 9 parts by mass of methyl methacrylate, 3 parts by mass of 2-hydroxyethyl methacrylate, 2 parts by mass of methacrylic acid, 1 part by mass of acrylamide, 1 part by mass of polytetramethylene glycol diacrylate (manufactured by NOF Corporation, product name: Blemmer ADT-250), and 2 parts by mass of an aqueous solution of polyoxyethylene nonylpropenyl phenyl ether ammonium sulfate (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., product name: Aqualon HS-1025) were emulsion-polymerized in deionized water at 70°C for 8 hours. After completion of polymerization, the pH was adjusted to 7 with aqueous ammonia. As a result, a (meth)acrylic resin emulsion 1 with a solids concentration of 56.5% by mass was obtained.

[0128] (Resin Emulsion 2) Using 0.5 parts by mass of 4,4'-azobis-4-cyanovaleric acid (manufactured by Otsuka Chemical Co., Ltd., product name: ACVA) as a polymerization initiator, 74 parts by mass of butyl acrylate, 14 parts by mass of methyl methacrylate, 9 parts by mass of 2-hydroxyethyl methacrylate, 2 parts by mass of methacrylic acid, 1 part by mass of acrylamide, and 3 parts by mass of an aqueous solution of polyoxyethylene nonylpropenylphenyl ether ammonium sulfate (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., product name: Aqualon HS-1025) were emulsion-polymerized in deionized water at 70°C for 8 hours. After completion of polymerization, the pH was adjusted to 7 with aqueous ammonia. As a result, a (meth)acrylic resin emulsion 2 with a solids concentration of 42.5% by mass was obtained.

[0129] (Resin solution 1) 49 parts by mass of ethyl acrylate, 20 parts by mass of 2-ethylhexyl acrylate, 21 parts by mass of methyl acrylate, 10 parts by mass of glycidyl methacrylate, and 0.5 parts by mass (solids content equivalent) of a benzoyl peroxide-based polymerization initiator as a polymerization initiator were reacted in 65 parts by mass of toluene and 50 parts by mass of ethyl acetate at 80° C. for 10 hours. After completion of the reaction, the resulting solution was cooled, and 25 parts by mass of xylene, 5 parts by mass of acrylic acid, and 0.5 parts by mass of tetradecyldimethylbenzylammonium chloride were added to the cooled solution, and the mixture was reacted at 85° C. for 32 hours while blowing air in, to obtain a (meth)acrylic resin solution (resin solution 1) with a solids concentration of 45% by mass.

[0130] (Adhesive coating liquid A and adhesive coating liquid E for forming adhesive resin layer (A) or adhesive resin layer (E)) 42.6 parts by mass of resin emulsion 1, 57.4 parts by mass of resin emulsion 2, 0.4 parts by mass of dimethylethanolamine, 5 parts by mass of an epoxy compound (manufactured by Nagase ChemteX Corporation, product name: EX-1610) as a crosslinking agent, 13 parts by mass of diethylene glycol monobutyl ether, and ２ 20 parts by mass of PEG-1000 and 20 parts by mass of PEG-1000 were mixed to prepare adhesive coating solutions A and E.

[0131] (Adhesive Coating Liquid C for Forming Adhesive Resin Layer (C)) 100 parts by mass of resin solution 1, 2.4 parts by mass of a polymerized rosin ester tackifier (rosin resin, manufactured by Arakawa Chemical Industries, Ltd., product name: Pencel D-125) (5.3 parts by mass per 100 parts by mass of adhesive resin, converted into solids), 1.3 parts by mass of an isocyanate crosslinking agent (manufactured by Mitsui Chemicals, Inc., product name: Olester P49-75S) (2.9 parts by mass per 100 parts by mass of adhesive resin, converted into solids), and 7.1 parts by mass of heat-expandable microspheres (manufactured by Sekisui Chemical Co., Ltd., product name: Advancell EM-503) (15.8 parts by mass per 100 parts by mass of adhesive resin, converted into solids), were mixed, and 37 parts by mass of toluene and 37 parts by mass of ethyl acetate were added to prepare adhesive coating liquid C.

[0132] <Preparation of Adhesive Film> (Examples 1 to 4) First, adhesive coating liquid A was applied to a silicone-release-treated separator and dried at 120°C for 3 minutes to form a resin film A with a thickness of 10 μm. This resin film A was then attached to the second surface of a polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name: Lumirror S10, thickness: 38 μm, double-sided corona-treated) that served as the substrate layer (B), to form an adhesive resin layer (A). Thereafter, adhesive coating liquid C was applied to the silicone-release-treated separator and dried at 80°C for 3 minutes to form a resin film C with a thickness of 50 μm. This resin film C was then attached to the first surface of the substrate layer (B) (the surface opposite to the surface of the substrate layer on which the adhesive resin layer (A) was provided). This resulted in an adhesive resin layer (C). As a result, a film 1 was obtained that included, in this order, an adhesive resin layer (A), a substrate layer (B), and an adhesive resin layer (C) capable of reducing adhesive strength in response to an external stimulus. Next, the adhesive coating solution E was applied to a silicone-release-treated separator and dried at 120°C for 3 minutes to form a 10 μm-thick resin film E. This resin film E was then bonded to the first surface of a polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name: Lumirror S10, thickness: 38 μm, double-sided corona-treated) serving as the substrate layer (D). This resulted in a film 2 having the substrate layer (D) and adhesive resin layer (E) in this order. The adhesive resin layer (C) of the film 1 was then bonded to the substrate layer (D) of the film 2. This resulted in a pressure-sensitive adhesive film 1 having the adhesive resin layer (A), substrate layer (B), an adhesive resin layer (C) capable of reducing adhesive strength in response to an external stimulus, substrate layer (D), and adhesive resin layer (E) in this order. The resulting pressure-sensitive adhesive film 1 was heated at 60°C for 5 days.

[0133] (Comparative Examples 1 to 4) Film 1 was produced in the same manner as in Examples 1 to 4. Film 2 was not laminated to Film 1, and Film 1 was used as is as PSA film 2. The obtained PSA film 2 was heated at 60°C for 5 days.

[0134] <Evaluation> [Releasability] (Examples 1 to 3) The adhesive resin layer (E) side of the adhesive film 1 was adhered to an adherend shown in Table 1. Then, the adhesive film 1 together with the adherend was pre-baked at 150°C for 1 hour. Next, using a compression molding machine, a liquid epoxy resin-based sealing material (manufactured by Nagase ChemteX Corporation, product name: R4212-2C) was compression molded (125°C, 600 seconds) onto the adhesive resin layer (A) of the adhesive film 1 to obtain a structure. The obtained structure was post-molded at 150°C for 4 hours. Thereafter, the structure was heated at 195°C for 60 seconds to peel the adhesive resin layer (C) of film 1 from the base layer (D) of film 2. Then, the adherend and film 2 were heated at 150°C for 60 seconds, and the adherend and film 2 were peeled off by peeling while maintaining the temperature at 150°C. Thereafter, the peelability was evaluated according to the following criteria. The results are shown in Table 1. A: The adhesive film was peeled from the adherend. B: The adhesive film was peeled from the adherend, but part of the adhesive film remained on the adherend. C: The adhesive film could not be peeled from the adherend.

[0135] Example 4 The adhesive resin layer (A) side of the adhesive film 1 was adhered to a support substrate (SUS430-2B). Then, the adhesive film 1 together with the support substrate was pre-baked at 150°C for 1 hour. Next, using a compression molding machine, a liquid epoxy resin-based sealant (manufactured by Nagase ChemteX Corporation, product name: R4212-2C) was compression molded (125°C, 600 seconds) onto the adhesive resin layer (E) of the adhesive film 1 to obtain a structure in which the adherend was the epoxy resin-based sealant. The obtained structure was subjected to post-mold curing at 150°C for 4 hours. Thereafter, the structure was heated at 195°C for 60 seconds to peel off the adhesive resin layer (C) of film 1 and the base layer (D) of film 2. The adherend and the film 2 were then heated at 150°C for 60 seconds, and the adherend and the film 2 were peeled off while the temperature was maintained at 150°C. Thereafter, the releasability was evaluated using the same criteria as in Examples 1 to 3. The results are shown in Table 1.

[0136] (Comparative Examples 1 to 3) The adhesive resin layer (C) side of the adhesive film 2 was adhered to an adherend shown in Table 1. The adhesive film 2 together with the adherend was then pre-baked at 150°C for 1 hour. Next, a liquid epoxy resin-based encapsulant (manufactured by Nagase ChemteX Corporation, product name: R4212-2C) was compression molded (125°C, 600 seconds) onto the adhesive resin layer (A) of the adhesive film 2 using a compression molding machine to obtain a structure. The resulting structure was post-molded at 150°C for 4 hours. The structure was then heated at 195°C for 60 seconds, and the adhesive film 2 was vertically peeled from the adherend while maintaining the temperature at 195°C. Thereafter, the peelability was evaluated using the same criteria as in Examples 1 to 3. The results are shown in Table 1.

[0137] (Comparative Example 4) The adhesive resin layer (A) side of the adhesive film 2 was adhered to a support substrate (SUS430-2B). The adhesive film 2, together with the support substrate, was pre-baked at 150°C for 1 hour. Next, using a compression molding machine, a liquid epoxy resin-based sealant (manufactured by Nagase ChemteX Corporation, product name: R4212-2C) was compression molded (125°C, 600 seconds) onto the adhesive resin layer (C) of the adhesive film 2 to obtain a structure in which the adherend was the epoxy resin-based sealant. The resulting structure was post-molded at 150°C for 4 hours. The structure was then heated at 195°C for 60 seconds, and the adhesive film 2 and the adherend were vertically peeled off while the temperature was maintained at 195°C. Thereafter, the peelability was evaluated using the same criteria as in Examples 1 to 3. The results are shown in Table 1.

[0138]

[0139] As in each example, by using an adhesive film having a specific layer structure, it was possible to improve the releasability from the support substrate or electronic component.

[0140] This application claims priority based on Japanese Patent Application No. 2024-049082, filed March 26, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0141] A: adhesive resin layer B: substrate layer C: adhesive resin layer D: substrate layer E: adhesive resin layer 1: film 2: film 50: adhesive film 60: sealing material 70: electronic component 80: supporting substrate 100: structure 200: electronic device

Claims

1. An adhesive film comprising: film 1 having, in this order, an adhesive resin layer (A), a base layer (B), and an adhesive resin layer (C) whose adhesive strength can be reduced by an external stimulus; and film 2 having, in this order, a base layer (D) and an adhesive resin layer (E), wherein the adhesive resin layer (C) and the base layer (D) are in direct contact with each other.

2. An adhesive film comprising, in this order, an adhesive resin layer (A), a base layer (B), an adhesive resin layer (C) capable of reducing adhesive strength in response to an external stimulus, a base layer (D), and an adhesive resin layer (E).

3. An adhesive film as described in claim 1 or 2, wherein the adhesive resin layer (A) contains one or more selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins and styrene adhesive resins.

4. The adhesive film according to any one of claims 1 to 3, wherein the total content of the gas-generating component and heat-expandable microspheres in the adhesive resin layer (A) is 0.1 mass% or less, when the entire adhesive resin layer (A) is taken as 100 mass%.

5. The adhesive film according to any one of claims 1 to 4, wherein the thickness of the adhesive resin layer (A) is 1 μm or more and 40 μm or less.

6. The pressure-sensitive adhesive film according to any one of claims 1 to 5, wherein the base layer (B) comprises one or more materials selected from the group consisting of polyolefin, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, polyimide, and ethylene-vinyl acetate copolymer.

7. The pressure-sensitive adhesive film according to any one of claims 1 to 6, wherein the thickness of the substrate layer (B) is 1 μm or more and 300 μm or less.

8. The adhesive film according to any one of claims 1 to 7, wherein the external stimulus comprises one or more selected from the group consisting of light irradiation and heat treatment.

9. The adhesive film according to any one of claims 1 to 8, wherein the adhesive resin layer (C) includes a layer whose adhesive strength decreases upon heat treatment.

10. The adhesive film according to claim 9, wherein the adhesive resin layer (C) contains one or more components selected from the group consisting of gas-generating components and heat-expandable microspheres.

11. The adhesive film according to claim 9 or 10, wherein the adhesive strength of the adhesive resin layer (C) decreases when heated at a temperature exceeding 100°C.

12. An adhesive film according to any one of claims 1 to 11, wherein the adhesive resin layer (C) contains one or more resins selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins.

13. The adhesive film according to any one of claims 1 to 12, wherein the thickness of the adhesive resin layer (C) is 10 μm or more and 100 μm or less.

14. The pressure-sensitive adhesive film according to any one of claims 1 to 13, wherein the substrate layer (D) comprises one or more materials selected from the group consisting of polyolefin, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, polyimide, and ethylene-vinyl acetate copolymer.

15. The adhesive film according to any one of claims 1 to 14, wherein the thickness of the substrate layer (D) is 1 μm or more and 300 μm or less.

16. An adhesive film according to any one of claims 1 to 15, wherein the adhesive resin layer (E) contains one or more resins selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins.

17. The adhesive film according to any one of claims 1 to 16, wherein the total content of the gas-generating component and heat-expandable microspheres in the adhesive resin layer (E) is 0.1 mass% or less, when the entire adhesive resin layer (E) is taken as 100 mass%.

18. An adhesive film according to any one of claims 1 to 17, wherein the thickness of the adhesive resin layer (E) is 1 μm or more and 40 μm or less.

19. An adhesive film according to any one of claims 1 to 18, further comprising an intermediate layer (F) between at least one selected from the group consisting of between the adhesive resin layer (A) and the base layer (B), between the base layer (B) and the adhesive resin layer (C), and between the base layer (D) and the adhesive resin layer (E).

20. The adhesive film according to claim 19, wherein the thickness of the intermediate layer (F) is 1 μm or more and 400 μm or less.

21. The adhesive film according to any one of claims 1 to 20, which is capable of temporarily fixing electronic components when the electronic components are sealed with a sealing material.

22. The adhesive film according to any one of claims 1 to 20, which is a backgrind tape.

23. A method for manufacturing an electronic device, comprising, in this order: a step of preparing a structure comprising a support substrate on one side of an adhesive film according to any one of claims 1 to 20 and an electronic component on the other side of the adhesive film; and a step of reducing the adhesive strength of the adhesive resin layer (C) by an external stimulus, thereby peeling the adhesive resin layer (C) from the base material layer (D).

24. The method for manufacturing an electronic device according to claim 23, wherein the step of preparing the structure includes the steps of bonding the adhesive resin layer (C) and the base material layer (D) together, and bonding one surface of the adhesive film to the support substrate.

25. The method for manufacturing an electronic device according to claim 23 or 24, further comprising the step of peeling the adhesive film from the electronic component.

26. The method for manufacturing an electronic device according to any one of claims 23 to 25, further comprising a step of encapsulating the electronic component with an encapsulant between the step of preparing the structure and the step of peeling the adhesive resin layer (C) from the base layer (D).

27. The method for manufacturing an electronic device according to claim 26, wherein the sealing material comprises one or more materials selected from the group consisting of epoxy resin sealing materials and silicone resin sealing materials.

28. The method for manufacturing an electronic device according to any one of claims 23 to 27, wherein the electronic device comprises a fan-out type package.

29. A method for manufacturing an electronic device, comprising the steps of: preparing a structure having an electronic component on one side of the adhesive film according to any one of claims 1 to 20; and back-grinding the electronic component, in this order.

30. The method for manufacturing an electronic device according to claim 29, wherein the electronic component comprises one or more selected from the group consisting of a semiconductor wafer and a mold wafer.

31. The method for manufacturing an electronic device according to claim 30, wherein the semiconductor wafer is a silicon wafer, a sapphire wafer, an indium-phosphorus wafer, a silicon-carbon wafer, a gallium-nitrogen wafer, a gallium-oxygen wafer, a gallium-arsenic wafer, a silicon wafer, a germanium wafer, a germanium-arsenic wafer, a gallium-phosphorus wafer, a gallium-arsenic-aluminum wafer, an indium-gallium-nitrogen wafer, a gallium-arsenic-phosphorus wafer, a glass wafer, or a lithium tantalate wafer.

32. The method for manufacturing an electronic device according to claim 30 or 31, wherein the electronic component includes a circuit-forming surface.

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