Method for manufacturing electronic equipment

Abstract

To provide a method for manufacturing electronic equipment that enables formation of fine wiring layers on an adhesive film.SOLUTION: A method for manufacturing electronic equipment includes a process for preparing a structure with a support substrate 60 and an adhesive film 50 attached to the support substrate 60, a process for forming a resist pattern 70 using a resist on the support adhesive film 50, a process for forming a wiring layer 80 on the adhesive film 50 by electroless plating, and a process for removing the resist pattern 70.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing an electronic device. [Background technology]

[0002] 2. Description of the Related Art A fan-out type WLP (wafer level package) has been developed as a technology capable of reducing the size and weight of electronic devices (eg, semiconductor devices).

[0003] As a technique relating to a manufacturing method of such a fan-out WLP, for example, the technique described in Patent Document 1 can be given.

[0004] Patent Document 1 describes a heat-resistant adhesive sheet for use in manufacturing semiconductor device that is attached when resin-encapsulating a substrateless semiconductor chip, the heat-resistant adhesive sheet having a base layer and an adhesive layer, the adhesive layer having an adhesive strength to SUS304 of 0.5 N / 20 mm or more after lamination and hardening due to stimuli received up until the completion of the resin-encapsulating process, such that the peel strength to the package is 2.0 N / 20 mm or less. Patent Document 1 describes how, when resin-sealing a substrateless semiconductor chip that does not use a metal lead frame, the chip is held in place without shifting from the specified position, and no adhesive residue is left after use. Furthermore, no gas is generated when heated, and the adhesive does not melt, allowing wiring to be securely installed, thereby improving the manufacturing yield of semiconductor packages and reducing contamination caused by adhesive residue when the sheet is peeled off. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-134811 A Summary of the Invention [Problem to be solved by the invention]

[0006] There are two main methods for fabricating fan-out WLPs using eWLB (Embedded Wafer Level Ball Grid Array). The first method is called the chip-first process, in which multiple electronic components such as semiconductor chips are temporarily fixed in a spaced-apart state onto an adhesive film attached to a support substrate, resin sealing is performed, and a redistribution layer (RDL layer) is formed on top of that. The second method is called the RDL-first process, in which a redistribution layer (RDL layer) is formed on a temporary fixing material, electronic components such as semiconductor chips are connected, and then resin sealing is performed.

[0007] The RDL first process is broadly divided into three types according to the method of forming the wiring layer: the subtractive method, the semi-additive method, and the full-additive method. In the subtractive method, a metal layer is formed on a temporary fixing material, and then etched to form a wiring layer. In the semi-additive method, (1) a thin metal film that serves as a seed layer is formed on a temporary fixing material, (2) a resist pattern is formed on the thin metal film by photolithography or other methods, (3) electrolytic plating is performed on the metal film to form a wiring layer according to the resist pattern, (4) the resist pattern is removed, and (5) etching is performed just enough to dissolve the plating seed layer in the areas that were covered by the resist pattern, thereby forming the wiring layer. In the full additive method, the surface on which the wiring layer is to be formed is first catalyzed, then a resist pattern is formed on the catalyzed surface by photolithography or the like, and then the wiring layer is formed by electroless plating.

[0008] The full additive method is advantageous for forming a fine wiring layer since it is possible to form the wiring layer without performing etching.

[0009] The present invention has been made in view of the above circumstances, and provides a method for manufacturing an electronic device that is capable of forming a fine wiring layer on an adhesive film. [Means for solving the problem]

[0010] According to the present invention, there is provided a method for manufacturing an electronic device as follows.

[0011] [1] A step of preparing a structure including a support substrate and an adhesive film attached to the support substrate; forming a resist pattern on the adhesive film using a resist; forming a wiring layer on the adhesive film by electroless plating; removing the resist pattern; A method for manufacturing an electronic device comprising the steps of: [2] The method for manufacturing an electronic device according to [1] above, wherein the wiring layer is formed without an etching process. [3] The method for manufacturing an electronic device according to [1] or [2] above, further comprising the step of mounting an electronic component on the wiring layer. [4] The method for manufacturing an electronic device according to [3] above, further comprising the step of encapsulating the electronic components mounted on the wiring layer with an encapsulant. [5] The adhesive resin layer (B) includes a layer whose adhesive strength is reduced by an external stimulus, The method for producing an electronic device described in [4] above, further comprising a first peeling step of peeling off the adhesive film from the support substrate or the wiring layer by applying an external stimulus to reduce the adhesive strength of the adhesive resin layer (B) after the sealing step. [6] The method for producing an electronic device according to [5] above, further comprising a second peeling step of peeling the adhesive film from the support substrate or the wiring layer after the first peeling step. [7] The method for producing an electronic device according to any one of the above [1] to [6], wherein the electronic device includes a fan-out package. [8] The adhesive film comprises a base layer, an adhesive resin layer (A) provided on a first surface side of the base layer, and an adhesive resin layer (B) provided on a second surface side of the base layer, At least one of the adhesive resin layer (A) or the adhesive resin layer (B) contains a reducing agent, The method for producing an electronic device according to any one of the above [1] to [7], wherein the wiring layer is formed on a surface of the adhesive resin layer (A) or the adhesive resin layer (B) on which the layer containing the reducing agent is provided. [9] The method for producing an electronic device according to [8] above, wherein the reducing agent contains one or more elements selected from the group consisting of copper, silver, palladium, iridium, platinum and gold.

[10] The method for producing an electronic device according to [9] above, wherein the reducing agent contains palladium.

[11] The method for producing an electronic device according to

[10] above, wherein the reducing agent comprises one or more selected from the group consisting of palladium alone and palladium halides.

[12] The method for manufacturing an electronic device according to any one of the above [8] to

[11] , wherein at least one of the adhesive resin layer (A) and the adhesive resin layer (B) 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.

[13] The method for producing an electronic device according to any one of the above [8] to

[12] , wherein the adhesive resin layer (B) includes a self-peeling adhesive resin layer whose adhesive strength decreases in response to an external stimulus.

[14] The self-peeling adhesive resin layer contains a thermal expansion adhesive, The method for producing an electronic device according to

[13] above, wherein the thermally expandable adhesive is an adhesive whose adhesive strength is reduced or lost when heated at a temperature exceeding 150°C. Effect of the Invention

[0012] According to the present invention, it is possible to provide a method for manufacturing an electronic device that is capable of forming a fine wiring layer on an adhesive film. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic example of the structure of an adhesive film according to the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing a schematic example of a wiring layer formed by electroless plating on an adhesive film according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] <Electronic device manufacturing method> First, a method for manufacturing an electronic device according to this embodiment will be described.

[0015] The method for manufacturing an electronic device according to this embodiment includes the steps of preparing a structure having a support substrate and an adhesive film attached to the support substrate, forming a resist pattern on the adhesive film using a resist, forming a wiring layer on the adhesive film by electroless plating, and removing the resist pattern.

[0016] Electroless plating is a method in which metal ions are reduced and precipitated by a chemical reaction between metal ions and a reducing agent.

[0017] Here, the formation of a wiring layer by electroless plating on an adhesive film according to this embodiment will be described with reference to FIG. 2, taking as an example a case in which the adhesive resin layer (A) contains a reducing agent. (1) The second surface of the adhesive film 50 (the surface on the second surface 10B side of the base layer) is attached to a supporting substrate 60, thereby preparing the structure 100. (2) A resist pattern 70 is formed on the first surface of the adhesive film 50 (the surface on the first surface 10A side of the base layer) using a resist. (3) The wiring layer 80 is formed by electroless plating on the first surface of the adhesive film 50. Specifically, a plating solution is brought into contact with the areas on the first surface of the adhesive film 50 where the resist pattern 70 is not formed, and the plating solution is brought into contact with the first surface of the adhesive film 50 to reduce and precipitate metal ions in the plating solution, thereby forming the wiring layer 80. (4) The resist pattern 70 is removed.

[0018] Although the adhesive resin layer (A) contains a reducing agent in the above description, the adhesive resin layer (B) may contain a reducing agent. In this case, the first surface of the adhesive film 50 is attached to the support substrate 60, and the resist pattern 70 and the wiring layer 80 are formed on the second surface. The adhesive resin layer (A) and the adhesive resin layer (B) may not contain a reducing agent. In that case, for example, a reducing agent may be applied to the first surface 10A or the second surface 10B of the adhesive film 50, and then the adhesive film 50 may be immersed in a plating solution to perform electroless plating. Alternatively, the adhesive film 50 may be immersed in a plating solution, and then a reducing agent may be applied to the adhesive film 50 to perform electroless plating.

[0019] According to the method for manufacturing an electronic device according to this embodiment, electroless plating is possible on an adhesive film, so that it is possible to form a wiring layer by a full additive method that does not require etching.

[0020] In the method for manufacturing an electronic device according to this embodiment, it is preferable that the wiring layer 80 is formed without going through an etching process. By not performing etching, it is possible to avoid breakage or shorting of wiring due to etching, which is advantageous from the viewpoint of forming fine wiring. In addition, the ability to form a wiring layer without etching is advantageous in terms of reducing the amount of waste liquid and reducing the environmental load, and therefore, the adhesive film of the present embodiment can reduce the amount of waste liquid and reduce the environmental load.

[0021] The method of electroless plating in the method of manufacturing an electronic device according to this embodiment is not particularly limited. For example, after forming the resist pattern 70, electroless plating can be performed by immersing the resist pattern 70 in a plating solution to form a plating bath.

[0022] The plating solution according to the present embodiment is not particularly limited as long as it contains a metal element. The metal element contained in the plating solution includes, for example, one or more elements selected from the group consisting of copper, platinum, gold, silver, nickel, chromium, cobalt, and tin, preferably one or more elements selected from the group consisting of copper and nickel, and more preferably nickel.

[0023] The plating solution according to this embodiment contains one or more selected from the group consisting of water and water-soluble organic solvents.

[0024] The treatment temperature of the electroless plating is not particularly limited, and is, for example, 25° C. or higher, preferably 35° C. or higher, more preferably 45° C. or higher, and is, for example, 95° C. or lower. The treatment time of the electroless plating is also not particularly limited, and is, for example, 5 minutes or more, preferably 10 minutes or more, more preferably 20 minutes or more, and is, for example, 3 hours or less.

[0025] The method for manufacturing an electronic device according to this embodiment may further include a step of mounting electronic components on the wiring layer 80.

[0026] The method for manufacturing an electronic device according to this embodiment may further include a step of sealing the electronic components mounted on the wiring layer 80 with a sealing material.

[0027] The method for sealing the electronic components with the sealing material is not particularly limited, but for example, the electronic components can be sealed by heating and curing the sealing material. The heating temperature is not particularly limited, but is preferably 150° C. or less from the viewpoint of maintaining the adhesive strength of the adhesive resin layer (B).

[0028] The form of the sealing material according to the present embodiment is not particularly limited, and may be, for example, granular, sheet-like, or liquid.

[0029] The components of the sealing material are not particularly limited, but preferably contain an epoxy resin-based sealing material, and more preferably contain a liquid epoxy resin-based sealing material, from the viewpoint of improving the affinity of the sealing material to the adhesive film 50 and enabling more uniform sealing of electronic components. As such an epoxy resin-based sealing material, for example, T693 / R4000 series, T693 / R1000 series, T693 / R5000 series, etc. manufactured by Nagase ChemteX Corporation can be used.

[0030] The sealing method in the sealing step is not particularly limited, but it is preferable to seal the electronic components with the sealing material using one or more molding methods selected from the group consisting of transfer molding, injection molding, compression molding, and cast molding.

[0031] The manufacturing method for an electronic device according to this embodiment may further include a first peeling step after the sealing step, in which the adhesive resin layer (B) includes a layer whose adhesive strength is reduced by an external stimulus, and an external stimulus is applied to reduce the adhesive strength of the adhesive resin layer (B) to peel off the adhesive film 50 from the support substrate 60 or the wiring layer 80. The means for reducing the adhesive strength of the adhesive resin layer (B) is not particularly limited. For example, when the adhesive resin layer (B) includes a layer whose adhesive strength is reduced by heating to a temperature exceeding 150°C, the adhesive strength can be reduced by heating to a temperature exceeding 150°C.

[0032] The method for manufacturing an electronic device according to this embodiment may further include a second peeling step of peeling the adhesive film 50 from the support substrate 60 or the wiring layer 80 after the first peeling step. Methods for peeling the adhesive film 50 from the support substrate 60 or the wiring layer 80 include, for example, a mechanical peeling method, a method in which the adhesive strength of the surface of the adhesive film 50 is reduced before peeling, and the like.

[0033] The type of electronic device obtained by the method for manufacturing an electronic device according to this embodiment is not particularly limited, but preferably includes a fan-out type package. In a fan-out type package, the terminals can be spread out 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. In addition, since a package substrate is not required, it can be made thinner.

[0034] In the manufacturing method for an electronic device according to this embodiment, preferably, the adhesive film 50 comprises a base layer 10, an adhesive resin layer (A) provided on the first surface 10A side of the base layer 10, and an adhesive resin layer (B) provided on the second surface 10B side of the base layer 10, and at least one of the adhesive resin layer (A) or the adhesive resin layer (B) contains a reducing agent, and a wiring layer 80 is formed on the surface of the adhesive resin layer (A) or the adhesive resin layer (B) on which the layer containing the reducing agent is provided.

[0035] The reducing agent according to the present embodiment is not particularly limited as long as it can reduce and deposit metal ions in the plating solution. From the viewpoint of more efficiently reducing and depositing metal ions, the reducing agent preferably contains one or more metals selected from the group consisting of iron, cobalt, nickel, tin, copper, silver, palladium, iridium, platinum, and gold, more preferably contains one or more metals selected from the group consisting of copper, silver, palladium, iridium, platinum, and gold, still more preferably contains palladium, and still more preferably contains one or more metals selected from the group consisting of palladium alone and palladium halides such as palladium chloride and palladium bromide.

[0036] The shape of the reducing agent according to the present embodiment is not particularly limited, but from the viewpoint of more efficiently reducing and precipitating metal ions, it is preferably in the form of particles.

[0037] Examples of commercially available reducing agents according to this embodiment include palladium nanopowder such as "ML-001N" manufactured by Iox Corporation, and composite particles of palladium particles and resin particles such as "HYPERTECH (registered trademark) PL-series photosensitive electroless plating nucleating agent" manufactured by Nissan Chemical Industries, Ltd.

[0038] The content of the reducing agent in this embodiment is not particularly limited as long as it is an amount that can reduce and precipitate metal ions in the plating solution, but from the viewpoint of more efficiently reducing and precipitating metal ions, the content is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, even more preferably 0.1 mass% or more, even more preferably 0.5 mass% or more, even more preferably 1.0 mass% or more, and even more preferably 5.0 mass% or more, based on the entire adhesive film.

[0039] The method for incorporating the reducing agent in this embodiment into at least one of the adhesive resin layer (A) and the adhesive resin layer (B) is not particularly limited, and an adhesive containing the reducing agent may be applied to the base layer 10, or an adhesive resin layer may be formed on the base layer 10 in advance and then impregnated with the reducing agent.

[0040] <Adhesive film used in the manufacturing method of electronic devices> Next, the adhesive film used in the method for producing an electronic device according to this embodiment will be described.

[0041] First, each layer constituting the adhesive film 50 according to this embodiment will be described.

[0042] (base material layer) The base layer 10 is a layer provided for the purpose of improving the properties of the adhesive film 50, such as handleability, mechanical properties, and heat resistance. The base layer 10 is not particularly limited, but may be, for example, a resin film. The resin constituting the resin film may be any known thermoplastic resin, including, for example, one or more selected from polyolefins such as polyethylene, polypropylene, poly(4-methyl-1-pentene), and poly(1-butene); polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyamides such as nylon-6, nylon-66, and polymetaxylene 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 an excellent balance of transparency, mechanical strength, price, and the like, one or more selected from polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyimide are preferred, and at least one selected from polyethylene terephthalate and polyethylene naphthalate is more preferred.

[0043] The substrate layer 10 may be a single layer or two or more layers. The resin film used to form the base layer 10 may be in the form of a stretched film or a uniaxially or biaxially stretched film. From the viewpoint of improving the mechanical strength of the base layer 10, however, a uniaxially or biaxially stretched film is preferable.

[0044] From the viewpoint of obtaining good film properties, the thickness of the base layer 10 is preferably 1 μm or more and 500 μm or less, more preferably 5 μm or more and 300 μm or less, and further preferably 10 μm or more and 250 μm or less. The substrate layer 10 may be subjected to a surface treatment in order to improve adhesion to other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coat treatment, etc. may be performed.

[0045] (Adhesive resin layer (A)) The adhesive resin layer (A) is a layer provided on one side of the base layer 10, and is a layer that comes into contact with the surface of an electronic component to temporarily fix the electronic component when, for example, sealing the electronic component with a sealing material during the manufacturing process of an electronic device.

[0046] The adhesive resin layer (A) preferably contains one or more types selected from (meth)acrylic adhesive resins, silicone-based adhesive resins, urethane-based adhesive resins, olefin-based adhesive resins, and styrene-based adhesive resins, and among these, from the viewpoint of easily adjusting the adhesive strength, it is more preferable that it contains a (meth)acrylic adhesive resin (a).

[0047] The (meth)acrylic adhesive resin (a) used in the adhesive resin layer (A) may be, for example, a copolymer containing a (meth)acrylic acid alkyl ester monomer unit (a1) and a monomer unit (a2) having a functional group capable of reacting with a crosslinking agent. In this embodiment, the (meth)acrylic acid alkyl ester means an acrylic acid alkyl ester, a methacrylic acid alkyl ester, or a mixture thereof.

[0048] The (meth)acrylic adhesive resin (a) according to this embodiment can be obtained, for example, by copolymerizing a monomer mixture containing a (meth)acrylic acid alkyl ester monomer (a1) and a monomer (a2) having a functional group capable of reacting with a crosslinking agent.

[0049] Examples of the monomer (a1) forming the (meth)acrylic acid alkyl ester monomer unit (a1) include (meth)acrylic acid alkyl esters having an alkyl group with about 1 to 12 carbon atoms. Preferred are (meth)acrylic acid alkyl esters having an alkyl group with 1 to 8 carbon atoms. Specific examples include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. These may be used alone or in combination of two or more. In the (meth)acrylic adhesive resin (a) according to this embodiment, the content of the (meth)acrylic acid alkyl ester monomer unit (a1) is preferably from 10 mass% to 98.9 mass%, more preferably from 50 mass% to 97 mass%, and even more preferably from 85 mass% to 95 mass%, when the sum of all monomer units in the (meth)acrylic adhesive resin (a) is 100 mass%.

[0050] Examples of the monomer (a2) that forms the monomer (a2) having a functional group that can react with a crosslinking agent include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, itaconic acid monoalkyl ester, mesaconic acid monoalkyl ester, citraconic acid monoalkyl ester, fumaric acid monoalkyl ester, maleic acid monoalkyl ester, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tertiary-butylaminoethyl acrylate, and tertiary-butylaminoethyl methacrylate. Preferred are acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, and the like. These may be used alone or in combination of two or more. In the (meth)acrylic adhesive resin (a) according to this embodiment, the content of the monomer unit (a2) is preferably from 1 to 40% by mass, more preferably from 1 to 20% by mass, and even more preferably from 1 to 10% by mass, when the sum of all monomer units in the (meth)acrylic adhesive resin (a) is taken as 100% by mass.

[0051] The (meth)acrylic adhesive resin (a) according to this embodiment may further contain, in addition to the monomer unit (a1) and the monomer unit (a2), 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 monomers (a1), (a2) and (a3), and also acts as an emulsifier in the case of emulsion polymerization.

[0052] Examples of the monomer (a3) ​​forming the bifunctional monomer unit (a3) ​​include allyl methacrylate, allyl acrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tetraethylene glycol di(meth)acrylate, and, for example, those having diacrylate or dimethacrylate at both ends and a main chain structure of propylene glycol type (e.g., Nippon Oil & Fats Corporation, trade names: PDP-200, PDP-400, ADP-200, ADP-400), tetramethylene glycol type (e.g., Nippon Oil & Fats Corporation, trade names: ADT-250, ADT-850) and mixtures thereof (e.g., Nippon Oil & Fats Corporation, trade names: ADET-1800, ADPT-4000).

[0053] In the (meth)acrylic adhesive resin (a) according to this embodiment, the content of the monomer unit (a3) ​​is preferably from 0.1 to 30% by mass, more preferably from 0.1 to 15% by mass, even more preferably from 0.1 to 20% by mass, and particularly preferably from 0.1 to 5% by mass, when the sum of all monomer units in the (meth)acrylic adhesive resin (a) is 100% by mass.

[0054] Examples of polymerizable surfactants include those in which a polymerizable 1-propenyl group has been introduced into the benzene ring of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: Aqualon RN-10, RN-20, RN-30, RN-50, etc.), those in which a polymerizable 1-propenyl group has been introduced into the benzene ring of an ammonium salt of a sulfate ester of polyoxyethylene nonylphenyl ether (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) according to this embodiment, the content of the polymerizable surfactant is preferably from 0.1% by mass to 30% by mass, more preferably from 0.1% by mass to 15% by mass, even more preferably from 0.1% by mass to 20% by mass, and particularly preferably from 0.1% by mass to 5% by mass, when the sum of all monomer units in the (meth)acrylic adhesive resin (a) is taken as 100% by mass.

[0055] The (meth)acrylic adhesive resin (a) according to this 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.

[0056] The polymerization reaction mechanism of the (meth)acrylic adhesive resin (a) according to the present embodiment may be radical polymerization, anionic polymerization, cationic polymerization, etc. Considering the production cost of the (meth)acrylic adhesive resin (a), the effect of the functional group of the monomer, the effect of ions on the surface of the electronic component, etc., it is preferable to polymerize by radical polymerization. When polymerizing by radical polymerization reaction, the following radical polymerization initiators are used: 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-butyl peroxy-2-hexanoate, t-butyl peroxy Examples of the peroxides include organic peroxides such as 2-ethylhexanoate, 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.

[0057] When polymerization is performed by emulsion polymerization, among these radical polymerization initiators, inorganic peroxides such as water-soluble 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 are preferred. Considering the influence of ions on the surface of electronic components, azo compounds having a carboxyl group in the molecule such as ammonium persulfate and 4,4'-azobis-4-cyanovaleric acid are more preferred, and azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid are particularly preferred.

[0058] The adhesive resin layer (A) according to this embodiment preferably further contains, in addition to the adhesive resin (A1), a crosslinking agent (A2) having two or more crosslinkable functional groups in one molecule. The crosslinking agent (A2) having two or more crosslinkable functional groups in one molecule is used to react with the functional groups of the adhesive resin (A1) to adjust the adhesive strength and cohesive strength. Examples of such crosslinking agents (A2) include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcin diglycidyl ether; isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate; and trimethylolpropane-tri-β-aziridinylpropionate. aziridine-based compounds such as N,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 compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine-based compounds such as hexamethoxymethylolmelamine. These may be used alone or in combination of two or more. Among these, it is preferable to contain one or more compounds selected from the group consisting of epoxy compounds, isocyanate compounds, and aziridine compounds.

[0059] The content of the crosslinking agent (A2) is usually preferably within a range in which the number of functional groups in the crosslinking agent (A2) is not greater than the number of functional groups in the adhesive resin (A1). However, if necessary, an excess of the crosslinking agent (A2) may be contained when new functional groups are generated by the crosslinking reaction or when the crosslinking reaction is slow. The content of the crosslinking agent (A2) 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 (A1), from the viewpoint of improving the balance between the heat resistance and adhesion of the adhesive resin layer (A).

[0060] 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 crosslinking adhesive resin layer, it may contain various additives for radiation crosslinking. The total content of the adhesive resin (A1) and the crosslinking agent (A2) in the adhesive resin layer (A) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, when the entire adhesive resin layer (A) is taken as 100% by mass. This can further suppress adhesive residue on the electronic component side when the adhesive film is peeled off from the electronic component.

[0061] The thickness of the adhesive resin layer (A) is not particularly limited, but is preferably, for example, from 1 μm to 100 μm, and more preferably from 3 μm to 50 μm.

[0062] The adhesive resin layer (A) can be formed, for example, by applying an adhesive onto the base layer 10. The adhesive may be dissolved in a solvent and applied as a coating liquid, or may be applied as a water-based emulsion, or the liquid adhesive may be directly applied. Among them, the adhesive coating solution dissolved in an organic solvent is preferred. The organic solvent is not particularly limited, and may be appropriately selected from known solvents in consideration of solubility and drying time. Examples of organic solvents include esters such as ethyl acetate and methyl acetate; ketones such as acetone and MEK; aromatics such as benzene, toluene and ethylbenzene; linear or cyclic aliphatics such as heptane, hexane and cyclohexane; and alcohols such as isopropanol and butanol. Ethyl acetate and toluene are preferred as organic solvents. These solvents may be used alone or in combination of two or more. The adhesive coating liquid can be coated by a conventional coating method such as a roll coater method, a reverse roll coater method, a gravure roll method, a bar coat method, a comma coater method, a die coater method, etc. There is no particular restriction on the drying conditions of the coated adhesive, but it is generally preferable to dry the coated adhesive at a temperature range of 80 to 200°C for 10 seconds to 10 minutes. More preferably, the coated adhesive is dried at 80 to 170°C for 15 seconds to 5 minutes. In order to sufficiently promote the crosslinking reaction between the crosslinking agent and the adhesive, the coated adhesive may be heated at 40 to 80°C for about 5 to 300 hours after drying of the adhesive coating liquid is completed. The base material layer 10 and the adhesive resin layer (A) may be formed by co-extrusion molding, or the base material layer 10 in the form of a film and the adhesive resin layer (A) in the form of a film may be laminated together.

[0063] (Adhesive resin layer (B)) The adhesive film 50 according to this embodiment includes an adhesive resin layer (B) on the second surface 10B side of the base layer 10 opposite the first surface 10A.

[0064] The adhesive resin layer (B) preferably contains one or more selected from (meth)acrylic adhesive resins, silicone-based adhesive resins, urethane-based adhesive resins, olefin-based adhesive resins, and styrene-based adhesive resins, and among these, more preferably contains a (meth)acrylic adhesive resin from the viewpoint of easily adjusting the adhesive strength.

[0065] The adhesive resin layer (B) preferably contains a self-peeling adhesive resin layer whose adhesive strength decreases in response to an external stimulus, thereby allowing the adhesive film 50 to be easily peeled off from the support substrate 60 by applying an external stimulus. Here, examples of the self-peeling adhesive resin layer whose adhesive strength decreases due to an external stimulus include a heat-peeling type self-peeling adhesive resin layer whose adhesive strength decreases due to heating, a radiation-peeling type self-peeling adhesive resin layer whose adhesive strength decreases due to radiation, etc. Among these, a heat-peeling type self-peeling adhesive resin layer whose adhesive strength decreases due to heating is preferred. Examples of heat-peelable self-peelable adhesive resin layers include adhesive resin layers composed of a heat-expandable adhesive containing a gas-generating component, a heat-expandable adhesive containing heat-expandable microspheres that can expand to reduce adhesive strength, and a heat-expandable adhesive whose adhesive strength is reduced as a result of the adhesive component undergoing a crosslinking reaction due to heat.

[0066] The self-peeling adhesive resin layer preferably contains a thermally expandable adhesive, and the thermally expandable adhesive is preferably an adhesive whose adhesive strength is reduced or lost when heated at a temperature exceeding 150°C. Here, the decrease or loss of adhesive strength due to heating at a temperature exceeding 150°C can be evaluated, for example, by attaching the adhesive resin layer (B) side to a stainless steel plate, performing a heat treatment at 140°C for 1 hour, and then heating at a temperature exceeding 150°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 150°C is set to a temperature higher than the temperature at which gas is generated or the temperature at which the thermally expandable microspheres thermally expand, and is appropriately set depending on the type of gas generated or the type of thermally expandable microspheres. In this embodiment, the loss of adhesive strength refers to, for example, a case where the 180° peel strength measured under conditions of 23°C and a tensile speed of 300 mm / min is less than 0.5 N / 25 mm.

[0067] Examples of gas generating components that can be used in the thermal expansion type pressure sensitive adhesive include azo compounds, azide compounds, and Meldrum's acid derivatives. In addition, inorganic foaming agents such as ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, 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'-oxybis(benzenesulfonyl)hydrazide, and the like can be used. Also usable are organic foaming agents such as hydrazine compounds such as p-toluenesulfonylsemicarbazide 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 added to the adhesive resin (B1) or may be directly bonded to the adhesive resin (B1).

[0068] As the heat-expandable microspheres used in the heat-expandable pressure-sensitive adhesive, for example, a microencapsulated foaming agent can be used. Examples of such heat-expandable microspheres include microspheres in which a substance that is easily gasified and expanded by 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, for example, by a coacervation method or an interfacial polymerization method. Thermally expandable microspheres can be added to the adhesive resin.

[0069] The content of at least one selected from the gas-generating component and the heat-expandable microspheres can be appropriately set depending on the expansion ratio and adhesive strength reduction of the heat-peelable adhesive resin layer (B) and is not particularly limited, and is, for example, 1 part by mass or more and 150 parts by mass or less, preferably 10 parts by mass or more and 130 parts by mass or less, and more preferably 12 parts by mass or more and 100 parts by mass or less, relative to 100 parts by mass of the adhesive resin (B1) in the heat-peelable adhesive resin layer (B). It is preferable to design the temperature at which gas is generated and the temperature at which the heat-expandable microspheres expand are above 150°C.

[0070] Examples of the adhesive resin (B1) constituting the thermally expandable adhesive include (meth)acrylic resin (b), urethane resin, silicone resin, polyolefin resin, polyester resin, polyamide resin, fluorine resin, styrene-diene block copolymer resin, etc. Among these, (meth)acrylic resin (b) is preferred.

[0071] The (meth)acrylic adhesive resin (b) used in the adhesive resin layer (B) may be, for example, a copolymer containing a (meth)acrylic acid alkyl ester monomer unit (b1) and a monomer unit (b2) having a functional group capable of reacting with a crosslinking agent. In this embodiment, the (meth)acrylic acid alkyl ester means an acrylic acid alkyl ester, a methacrylic acid alkyl ester, or a mixture thereof.

[0072] The (meth)acrylic adhesive resin (b) according to this embodiment can be obtained, for example, by copolymerizing a monomer mixture containing a (meth)acrylic acid alkyl ester monomer (b1) and a monomer (b2) having a functional group capable of reacting with a crosslinking agent.

[0073] Examples of the monomer (b1) forming the (meth)acrylic acid alkyl ester monomer unit (b1) include (meth)acrylic acid alkyl esters having an alkyl group with about 1 to 12 carbon atoms. Preferred are (meth)acrylic acid alkyl esters having an alkyl group with 1 to 8 carbon atoms. Specific examples include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. These may be used alone or in combination of two or more. In the (meth)acrylic adhesive resin (b) according to this embodiment, the content of the (meth)acrylic acid alkyl ester monomer unit (b1) is preferably from 10 mass% to 98.9 mass%, more preferably from 50 mass% to 97 mass%, and even more preferably from 85 mass% to 95 mass%, when the sum of all monomer units in the (meth)acrylic adhesive resin (b) is 100 mass%.

[0074] Examples of the monomer (b2) that forms the monomer (b2) having a functional group that can react with a crosslinking agent include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, itaconic acid monoalkyl ester, mesaconic acid monoalkyl ester, citraconic acid monoalkyl ester, fumaric acid monoalkyl ester, maleic acid monoalkyl ester, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tertiary-butylaminoethyl acrylate, and tertiary-butylaminoethyl methacrylate. Preferred are acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, and the like. These may be used alone or in combination of two or more. In the (meth)acrylic adhesive resin (b) according to this embodiment, the content of the monomer unit (b2) is preferably from 1 to 40% by mass, more preferably from 1 to 20% by mass, and even more preferably from 1 to 10% by mass, when the sum of all monomer units in the (meth)acrylic adhesive resin (b) is taken as 100% by mass.

[0075] The (meth)acrylic adhesive resin (b) according to this embodiment may further contain, in addition to the monomer unit (b1) and the monomer unit (b2), a bifunctional monomer unit (b3) 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 monomers (b1), (b2) and (b3), and also acts as an emulsifier in the case of emulsion polymerization.

[0076] Examples of the monomer (b3) forming the bifunctional monomer unit (b3) include allyl methacrylate, allyl acrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tetraethylene glycol di(meth)acrylate, and, for example, those having diacrylate or dimethacrylate at both ends and a main chain structure of propylene glycol type (e.g., Nippon Oil & Fats Corporation, trade names: PDP-200, PDP-400, ADP-200, ADP-400), tetramethylene glycol type (e.g., Nippon Oil & Fats Corporation, trade names: ADT-250, ADT-850) and mixtures thereof (e.g., Nippon Oil & Fats Corporation, trade names: ADET-1800, ADPT-4000).

[0077] In the (meth)acrylic adhesive resin (b) according to this embodiment, the content of the monomer unit (b3) is preferably from 0.1 to 30% by mass, more preferably from 0.1 to 15% by mass, even more preferably from 0.1 to 20% by mass, and particularly preferably from 0.1 to 5% by mass, when the sum of all monomer units in the (meth)acrylic adhesive resin (b) is 100% by mass.

[0078] Examples of polymerizable surfactants include those in which a polymerizable 1-propenyl group has been introduced into the benzene ring of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: Aqualon RN-10, RN-20, RN-30, RN-50, etc.), those in which a polymerizable 1-propenyl group has been introduced into the benzene ring of an ammonium salt of a sulfate ester of polyoxyethylene nonylphenyl ether (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 (b) according to this embodiment, the content of the polymerizable surfactant is preferably from 0.1% by mass to 30% by mass, more preferably from 0.1% by mass to 15% by mass, even more preferably from 0.1% by mass to 20% by mass, and particularly preferably from 0.1% by mass to 5% by mass, when the sum of all monomer units in the (meth)acrylic adhesive resin (b) is taken as 100% by mass.

[0079] The (meth)acrylic adhesive resin (b) according to this 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.

[0080] The polymerization reaction mechanism of the (meth)acrylic adhesive resin (b) according to the present embodiment may be radical polymerization, anionic polymerization, cationic polymerization, etc. Considering the production cost of the (meth)acrylic adhesive resin (b), the effect of the functional group of the monomer, the effect of ions on the surface of the electronic component, etc., it is preferable to polymerize by radical polymerization. When polymerizing by radical polymerization reaction, the following radical polymerization initiators are used: 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-butyl peroxy-2-hexanoate, t-butyl peroxy Examples of the peroxides include organic peroxides such as 2-ethylhexanoate, 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.

[0081] When polymerization is performed by emulsion polymerization, among these radical polymerization initiators, inorganic peroxides such as water-soluble 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 are preferred. Considering the influence of ions on the surface of electronic components, azo compounds having a carboxyl group in the molecule such as ammonium persulfate and 4,4'-azobis-4-cyanovaleric acid are more preferred, and azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid are particularly preferred.

[0082] The adhesive resin layer (B) according to this embodiment preferably further contains, in addition to the adhesive resin (B1), a crosslinking agent (B2) having two or more crosslinkable functional groups in one molecule. The crosslinking agent (B2) having two or more crosslinkable functional groups in one molecule is used to react with the functional groups of the adhesive resin (B1) to adjust the adhesive strength and cohesive strength. Examples of such crosslinking agents (B2) include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcin diglycidyl ether; isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate; and trimethylolpropane-tri-β-aziridinylpropionate. aziridine-based compounds such as N,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 compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine-based compounds such as hexamethoxymethylolmelamine. These may be used alone or in combination of two or more. Among these, it is preferable to contain one or more compounds selected from the group consisting of epoxy compounds, isocyanate compounds, and aziridine compounds.

[0083] The content of the crosslinking agent (B2) is usually preferably within a range in which the number of functional groups in the crosslinking agent (B2) is not greater than the number of functional groups in the adhesive resin (B1). However, if necessary, an excess of the crosslinking agent (B2) may be contained when new functional groups are generated by the crosslinking reaction or when the crosslinking reaction is slow. The content of the crosslinking agent (B2) in the adhesive resin layer (B) is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the adhesive resin (B1).

[0084] The adhesive resin layer (B) according to the present embodiment preferably contains a tackifier resin in addition to the adhesive resin (B1) from the viewpoint of improving adhesion to the support substrate. It is preferable to include a tackifier resin in the adhesive resin layer (B) because it is easy to adjust the adhesion to the support substrate at around room temperature. The tackifier resin is preferably one whose softening point is 100°C or higher. Specific examples of the tackifier resin include rosin-based resins such as rosin-based derivatives treated by esterification or the like; terpene-based resins such as α-pinene-based, β-pinene-based, dipentene-based, and terpene phenol-based resins; natural rosins such as gum-based, wood-based, and tall oil-based resins; hydrogenated, disproportionated, polymerized, maleated, and petroleum resins of these natural rosins; coumarone-indene resins, etc.

[0085] Among these, those having a softening point in the range of 100 to 160° C. are more preferred, and those having a softening point in the range of 120 to 150° C. are particularly preferred. By using a tackifier resin having a softening point in the above range, not only is contamination and adhesive residue on the support substrate reduced, but the adhesion to the support substrate in the working environment can be further improved. Furthermore, by using a polymerized rosin ester-based tackifier resin as the tackifier resin, not only is contamination and adhesive residue on the support substrate reduced, but the adhesion to the support substrate in an environment of 80 to 130° C. is improved, and in the case of a heat-expandable pressure-sensitive adhesive containing heat-expandable microspheres, the heat-expandable microspheres can be more easily peeled off from the support substrate after expansion.

[0086] The blending ratio of the tackifier resin is not particularly limited, and may be appropriately selected so that the elastic modulus of the adhesive resin layer (B) can be adjusted within a desired predetermined numerical range. However, in terms of the elastic modulus and initial peeling force of the adhesive resin layer (B), it is preferable to set it to 1 to 100 parts by mass with respect to 100 parts by mass of the adhesive resin (B1). When the blending ratio of the tackifier resin is equal to or more than the above lower limit with respect to 100 parts by mass of the adhesive resin (B1), the adhesion to the support substrate during operation tends to be good. On the other hand, when it is equal to or less than the above upper limit, the attachment to the support substrate at room temperature tends to be good. In terms of the adhesion to the support substrate and the attachment at room temperature, it is more preferable to set the blending ratio of the tackifier resin to 2 to 50 parts by mass with respect to 100 parts by mass of the adhesive resin (B1). In addition, the acid value of the tackifier resin is preferably 30 or less. When the acid value of the tackifier resin is equal to or less than the above upper limit, adhesive residue tends to be less likely to be left on the support substrate during peeling.

[0087] The adhesive resin layer (B) may contain additives such as plasticizers as other components. The total content of the adhesive resin (B1), crosslinking agent (B2) and tackifier resin in the adhesive resin layer (B) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, when the entire adhesive resin layer (B) is taken as 100% by mass. Furthermore, when the adhesive resin layer (B) is composed of a heat-expandable adhesive, the total content of the adhesive resin (B1), crosslinking agent (B2), tackifier resin, gas-generating component and heat-expandable microspheres in the adhesive resin layer (B) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, when the entire adhesive resin layer (B) is taken as 100% by mass.

[0088] The thickness of the adhesive resin layer (B) is not particularly limited, but is preferably, for example, from 5 μm to 300 μm, and more preferably from 20 μm to 150 μm.

[0089] The adhesive resin layer (B) can be formed, for example, by a method of applying an adhesive coating liquid onto the base layer 10, or by transferring the adhesive resin layer (B) formed on a separator onto the base layer 10. The adhesive coating liquid can be coated by a conventional coating method such as a roll coater method, a reverse roll coater method, a gravure roll method, a bar coat method, a comma coater method, a die coater method, etc. There is no particular restriction on the drying conditions of the coated adhesive, but it is generally preferable to dry the coated adhesive at a temperature range of 80 to 200°C for 10 seconds to 10 minutes. More preferably, the coated adhesive is dried at 80 to 170°C for 15 seconds to 5 minutes. In order to sufficiently promote the crosslinking reaction between the crosslinking agent and the adhesive, the coated adhesive may be heated at 40 to 80°C for about 5 to 300 hours after drying of the adhesive coating liquid is completed. The base material layer 10 and the adhesive resin layer (B) may be formed by co-extrusion molding, or the base material layer 10 in the form of a film and the adhesive resin layer (B) in the form of a film may be laminated together.

[0090] (Other layers) The adhesive film 50 of this embodiment may further include, for example, an unevenness absorbing layer, an impact absorbing layer, an easy-adhesion layer, etc., between the base layer 10 and the adhesive resin layer (A) or between the base layer 10 and the adhesive resin layer (B), as long as the effect of this embodiment is not impaired.

[0091] The unevenness-absorbing layer is preferably formed from natural rubber or synthetic rubber, or synthetic resin having rubber elasticity, having a Shore D hardness of, for example, 50 or less, preferably 40 or less according to Shore D hardness of ASTM D-2240. The thickness of the unevenness-absorbing layer is, for example, 500 μm or less, preferably 5 to 300 μm, more preferably 10 to 150 μm.

[0092] Examples of synthetic rubber or synthetic resin include synthetic rubbers such as nitrile, diene, and acrylic, thermoplastic elastomers such as polyolefin and polyester, and synthetic resins having rubber elasticity such as ethylene-vinyl acetate copolymer, polyurethane, polybutadiene, and soft polyvinyl chloride. In this embodiment, even if the polymer is essentially hard, such as polyvinyl chloride, it can be used that has rubber elasticity due to the combination with a compounding agent such as a plasticizer or softener. In addition, the adhesive resins exemplified in the adhesive resin layer (A) and the adhesive resin layer (B) can also be preferably used to form the unevenness absorbing layer.

[0093] (Adhesive film thickness) The total thickness of the adhesive film 50 according to this embodiment is preferably 10 μm or more and 1000 μm or less, and more preferably 20 μm or more and 500 μm or less, from the viewpoint of the balance between mechanical properties and ease of handling.

[0094] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

[0095] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of the present invention that can achieve the object of the present invention are included in the present invention. [Explanation of symbols]

[0096] A Adhesive resin layer B Adhesive resin layer 10 Base material layer 10A 1st side 10B 2nd side 50 Adhesive Film 60 Support substrate 70 Resist Pattern 80 wiring layer 100 structures

Claims

1. A step of preparing a structure including a support substrate and an adhesive film attached to the support substrate; forming a resist pattern on the adhesive film using a resist; forming a wiring layer on the adhesive film by electroless plating; removing the resist pattern; A method for manufacturing an electronic device, comprising:

2. The method for manufacturing an electronic device according to claim 1 , wherein the wiring layer is formed without an etching process.

3. The method for manufacturing an electronic device according to claim 1 , further comprising the step of mounting an electronic component on the wiring layer.

4. The method for manufacturing an electronic device according to claim 3 , further comprising the step of sealing the electronic components mounted on the wiring layer with a sealing material.

5. The adhesive resin layer (B) includes a layer whose adhesive strength is reduced by an external stimulus, 5. The method for manufacturing an electronic device according to claim 4, further comprising a first peeling step of peeling off the adhesive film from the support substrate or the wiring layer by applying an external stimulus to reduce the adhesive strength of the adhesive resin layer (B) after the sealing step.

6. The method for manufacturing an electronic device according to claim 5 , further comprising, after the first peeling step, a second peeling step of peeling the adhesive film from the support substrate or the wiring layer.

7. The method for manufacturing an electronic device according to claim 1 or 2, wherein the electronic device comprises a fan-out type package.

8. The pressure-sensitive adhesive film comprises a base layer, an adhesive resin layer (A) provided on a first surface side of the base layer, and an adhesive resin layer (B) provided on a second surface side of the base layer, At least one of the adhesive resin layer (A) or the adhesive resin layer (B) contains a reducing agent, The method for manufacturing an electronic device according to claim 1 or 2, wherein the wiring layer is formed on a surface of the adhesive resin layer (A) or the adhesive resin layer (B) on which the layer containing the reducing agent is provided.

9. 9. The method for manufacturing an electronic device according to claim 8, wherein the reducing agent comprises one or more selected from the group consisting of iron, cobalt, nickel, tin, copper, silver, palladium, iridium, platinum, and gold.

10. The method for manufacturing an electronic device according to claim 9 , wherein the reducing agent comprises palladium.

11. The method for producing an electronic device according to claim 10, wherein the reducing agent comprises one or more selected from the group consisting of palladium elemental and palladium halides.

12. 9. The method for manufacturing an electronic device according to claim 8, wherein at least one of the adhesive resin layer (A) and the adhesive resin layer (B) 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.

13. The method for manufacturing an electronic device according to claim 8 , wherein the adhesive resin layer (B) includes a self-peeling adhesive resin layer whose adhesive strength decreases in response to an external stimulus.

14. the self-peeling adhesive resin layer contains a thermal expansion adhesive, The method for manufacturing an electronic device according to claim 13 , wherein the thermally expandable pressure-sensitive adhesive is a pressure-sensitive adhesive whose adhesive strength is reduced or lost when heated at a temperature exceeding 150° C.

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