Method for manufacturing electronic device

Abstract

To provide a method for manufacturing an electronic device which can suppress positional deviation of an electronic component in a sealing step.SOLUTION: A method for manufacturing an electronic device includes: a preparation step of preparing a structure 100 having an adhesive film 50 having a base material layer 10, an adhesive resin layer (A) which is provided on a first surface side of the base material layer 10 and temporarily fixes an electronic component 70, and an adhesive resin layer (B) provided on a second surface side of the base material layer 10, an electronic component 70 stuck to the adhesive resin layer (A) of the adhesive film 50, and a support substrate 80 stuck to the adhesive resin layer (B) of the adhesive film 50; and a sealing step of sealing the electronic component 70 by a sealing material 60, wherein the method includes an air removing step of removing an air reservoir in the structure 100 between the preparation step and the sealing step.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 Fan-out packages have been developed as a technology that can reduce the size and weight of electronic devices (eg, semiconductor devices). In eWLB (Embedded Wafer Level Ball Grid Array), which is one of the methods for manufacturing fan-out packages, multiple electronic components such as semiconductor chips are temporarily fixed in a spaced-apart state on an adhesive film attached to a support substrate, and the multiple electronic components are collectively sealed with a sealing material. Here, the adhesive film needs to be fixed to the electronic components and the support substrate during the sealing process, and after sealing, it needs to be removed from the sealed electronic components together with the support substrate.

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

[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] According to the inventors' research, it has become clear that when electronic components are placed on an adhesive film and sealed with a sealing material, the position of the electronic components may become misaligned (hereinafter also referred to as misalignment of the electronic components). The present invention has been made in view of the above circumstances, and provides a method for manufacturing an electronic device that can suppress misalignment of electronic components during the sealing process. [Means for solving the problem]

[0007] According to the present invention, there is provided a method for manufacturing an electronic device as follows.

[0008] [1] An adhesive film including a base layer, an adhesive resin layer (A) provided on a first surface side of the base layer and for temporarily fixing an electronic component, and an adhesive resin layer (B) provided on a second surface side of the base layer; an electronic component attached to the adhesive resin layer (A) of the adhesive film; A preparation step of preparing a structure including a support substrate attached to the adhesive resin layer (B) of the adhesive film; a sealing step of sealing the electronic component with a sealing material; A method for manufacturing an electronic device comprising: A method for manufacturing an electronic device, comprising the steps of: removing air pockets in the structure between the preparing step and the sealing step. [2] The method for manufacturing an electronic device according to [1] above, wherein in the air removal step, the structure is placed in a reduced pressure environment. [3] The method for manufacturing an electronic device according to the above-mentioned [1] or [2], wherein in the air removal step, an electronic component fixing member is laminated on the electronic component of the structure. [4] The method for manufacturing an electronic device according to [3] above, wherein in the air removal step, the structure in which the electronic component fixing members are stacked is heated. [5] The method for manufacturing an electronic device according to the above-mentioned [3] or [4], wherein in the air removal step, the structure in which the electronic component fixing members are stacked is pressurized. [6] The method for producing an electronic device according to any one of the above [3] to [5], wherein the electronic part fixing member contains polyolefin. [7] The method for producing an electronic device according to any one of the above [3] to [6], wherein the electronic part fixing member is in the form of a film. [8] The method for producing an electronic device according to any one of the above [1] to [7], wherein in the air removing step, the heating temperature is less than 70°C. [9] The method for producing an electronic device according to any one of the above [1] to [8], wherein in the air removing step, the heating time is less than 5 minutes.

[10] The method for producing an electronic device according to any one of the above [1] to [9], further comprising, after the air removing step, a moisture removing step of removing moisture from within the structure.

[11] The method for manufacturing an electronic device according to any one of the above [1] to

[10] , wherein in the sealing step, the electronic components are sealed with the sealing material by using one or more molding methods selected from the group consisting of transfer molding, injection molding, compression molding, and cast molding.

[12] The adhesive resin layer (B) is a layer whose adhesive strength decreases in response to an external stimulus, The method for producing an electronic device according to any one of the above [1] to

[11] , further comprising, after the sealing step, a first peeling step of peeling off the support substrate from the structure by applying an external stimulus to reduce the adhesive strength of the adhesive resin layer (B).

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

[12] above, further comprising a second peeling step of peeling the adhesive film from the electronic component after the first peeling step.

[14] The method for producing an electronic device according to any one of the above [1] to

[13] , wherein the adhesive resin constituting the adhesive resin layer (A) 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.

[15] The adhesive resin layer (B) contains a thermally expandable adhesive, The method for producing an electronic device according to any one of the above [1] to

[14] , 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.

[16] The method for producing an electronic device according to any one of the above [1] to

[15] , wherein the sealing material comprises an epoxy resin-based sealing material.

[17] The method for producing an electronic device according to any one of the above [1] to

[16] , wherein the electronic device includes a fan-out package. Effect of the Invention

[0009] According to the present invention, it is possible to provide a method for manufacturing an electronic device that can suppress misalignment of electronic components during a sealing process. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a schematic example of a structure of an adhesive film according to an embodiment of the present invention. [Diagram 2] 1A to 1C are cross-sectional views illustrating an example of a method for manufacturing an electronic device according to an embodiment of the present invention. [Diagram 3] 1A to 1C are cross-sectional views illustrating an example of a method for manufacturing an electronic device according to an embodiment of the present invention. [Figure 4] FIG. 2 is a cross-sectional view showing a schematic view of an electronic component fixing member laminated on an electronic component of the structure according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] 1. Manufacturing method of electronic device A method for manufacturing an electronic device according to this embodiment will be described below.

[0012] First, a method for manufacturing an electronic device according to the present embodiment will be described. Fig. 1 is a cross-sectional view that illustrates an example of the structure of an adhesive film 50 according to an embodiment of the present invention. 2 and 3 are cross-sectional views that typically show an example of a method for manufacturing an electronic device according to an embodiment of the present invention. The method for manufacturing an electronic device according to this embodiment includes at least the following three steps. (1) A preparation step of preparing a structure 100 including a base layer 10, an adhesive film 50 including an adhesive resin layer (A) provided on the first surface 10A side of the base layer 10 and for temporarily fixing an electronic component 70, and an adhesive resin layer (B) provided on the second surface 10B side of the base layer 10, the electronic component 70 attached to the adhesive resin layer (A) of the adhesive film 50, and a support substrate 80 attached to the adhesive resin layer (B) of the adhesive film 50. (2) An air removal step for removing air pockets in the structure 100 (3) Sealing process of sealing electronic components 70 with sealing material 60

[0013] As described above, the inventors' research has revealed that when electronic components are placed on an adhesive film and sealed with a sealing material, the position of the electronic components may become misaligned (hereinafter also referred to as misalignment of the electronic components). The present inventors have conducted extensive research to achieve the above object. As a result, they have found that in the process of sealing the electronic components, the electronic components are not able to withstand the pressure caused by the flow of the sealing material, resulting in displacement of the electronic components. Furthermore, they have found that air pockets formed in the structure 100, particularly air pockets formed between the electronic components 70 and the adhesive film 50, reduce the adhesion between the electronic components 70 and the adhesive film 50, resulting in displacement of the electronic components. Based on the above findings, the present inventors have further investigated the matter and found for the first time that removing air pockets in structure 100 before the sealing step maintains the adhesion between electronic component 70 and adhesive film 50, thereby preventing the electronic component from shifting in position during the sealing step. That is, according to the method for manufacturing an electronic device of this embodiment, by removing air pockets in the structure 100 before the sealing step, adhesion between the electronic component 70 and the adhesive film 50 is maintained, so that it is possible to prevent the position of the electronic component 70 from being shifted due to the pressure caused by the flow of the sealing material 60 during the step of sealing the electronic component. As described above, according to the method for manufacturing an electronic device according to this embodiment, it is possible to suppress misalignment of electronic components during the sealing process.

[0014] Each step of the method for manufacturing an electronic device according to this embodiment will be described below.

[0015] ((1) Preparation process) In the preparation process, a structure 100 is prepared, which includes an adhesive film 50, an electronic component 70 attached to the adhesive resin layer (A) of the adhesive film 50, and a support substrate 80 attached to the adhesive resin layer (B) of the adhesive film 50.

[0016] Such a structure 100 can be fabricated, for example, by the following procedure. First, the adhesive film 50 is attached onto the support substrate 80 so that the adhesive resin layer (B) faces the support substrate 80. A protective film called a separator may be attached onto the adhesive resin layer (B), and the protective film can be peeled off to attach the exposed surface of the adhesive resin layer (B) to the surface of the support substrate 80. The support substrate 80 may be, for example, a quartz substrate, a glass substrate, or a SUS substrate.

[0017] Next, the electronic component 70 is disposed on the adhesive resin layer (A) of the adhesive film 50 attached onto the supporting substrate 80, whereby the structure 100 can be obtained. Examples of the electronic component 70 include semiconductor chips such as ICs, LSIs, discrete devices, light-emitting diodes, and light-receiving elements, semiconductor panels, and semiconductor packages.

[0018] ((2) Air Removal Process) The air removal process will now be described.

[0019] In the air removal step, it is preferable to place the structure 100 in a reduced pressure environment. This removes air pockets that have formed between the adhesive film 50 and the electronic components 70, further suppressing misalignment of the electronic components in the sealing step. The degree of pressure reduction when placing the structure 100 in a reduced pressure environment is not particularly limited, but is preferably 1.0×10 5 Pa or less, more preferably 5.0×10 4 Pa or less, more preferably 1.0×10 4 Pa or less, more preferably 5.0×10 3 Pa or less, for example, 1.0×10 -2 Pa or more, preferably 1.0 Pa or more, more preferably 1.0×10 2 Pa or more.

[0020] In the air removal step, as shown in Fig. 4, it is preferable to laminate an electronic component fixing member 110 on the electronic component 70 of the structure 100. This allows the electronic component fixing member 110 to be in close contact with the adhesive film 50 with the electronic component 70 sandwiched between the electronic component fixing member 110 and the adhesive film 50. This removes air pockets that have formed between the adhesive film 50 and the electronic component 70, further suppressing misalignment of the electronic component in the sealing step.

[0021] In the air removal step, it is preferable to heat the structure 100 in which the electronic component fixing members 110 are laminated. This allows the electronic component fixing members 110 to adhere more closely to the adhesive film 50, and air pockets that have formed between the adhesive film 50 and the electronic components 70 are more effectively removed, further suppressing misalignment of the electronic components in the sealing step.

[0022] In the air removal step, it is preferable to pressurize the structure 100 in which the electronic component fixing members 110 are laminated. This allows the electronic component fixing members 110 to adhere more closely to the adhesive film 50, and air pockets that have formed between the adhesive film 50 and the electronic components 70 are more effectively removed, further suppressing displacement of the electronic components in the sealing step.

[0023] The electronic component fixing member 110 preferably contains a thermoplastic resin, and more preferably contains one or more polyolefins selected from the group consisting of polyethylene, polypropylene, poly(4-methyl-1-pentene), poly(1-butene), etc. This allows the electronic component fixing member 110 to adhere more closely to the adhesive film 50, and air pockets that have formed between the adhesive film 50 and the electronic component 70 are further removed, further suppressing displacement of the electronic component during the sealing process.

[0024] The electronic component fixing member 110 is preferably in the form of a film, which makes it easier to laminate onto the structure 100 and also easier to remove from the structure 100 after the air removal step is completed.

[0025] After the air removal process is completed, the electronic component fixing member 110 is removed from the structure 100.

[0026] The air removal step may involve heating the structure.

[0027] The heating temperature in the air removal process is not particularly limited, but from the viewpoint of more efficiently removing air pockets that have formed between the adhesive film 50 and the electronic component 70, it is preferably 30°C or higher, more preferably 35°C or higher, more preferably 40°C or higher, even more preferably 45°C or higher, even more preferably 50°C or higher, even more preferably 55°C or higher, even more preferably 60°C or higher, and even more preferably 65°C or higher; and from the viewpoint of preventing deterioration of components such as the electronic component fixing member 110 and the adhesive film 50, and from the viewpoint of suppressing thermal expansion of the adhesive film 50 when the adhesive film 50 is of a thermal expansion type, it is preferably less than 150°C, more preferably less than 100°C, even more preferably less than 90°C, even more preferably less than 70°C, even more preferably less than 68°C, and even more preferably less than 67°C.

[0028] The heating time in the air removal process is not particularly limited, but is, for example, 1 second or more, and from the viewpoint of preventing deterioration of components such as the electronic component fixing member 110 and the adhesive film 50, and from the viewpoint of suppressing thermal expansion of the adhesive film 50 if the adhesive film 50 is of a thermal expansion type, the heating time is preferably less than 5 minutes, more preferably less than 3 minutes, even more preferably less than 1 minute, even more preferably less than 30 seconds, and even more preferably less than 10 seconds.

[0029] The method for heating the structure 100 is not particularly limited, but for example, a generally known heat treatment method such as an oven, a dryer, a heating roll, or a drying furnace can be used.

[0030] ((3) Sealing process) Next, the electronic components 70 are encapsulated with the encapsulant 60 . The electronic components 70 are covered with the sealing material 60, and the sealing material 60 is cured at a temperature of, for example, 150° C. or less to seal the electronic components 70. The form of the sealing material 60 is not particularly limited, but may be, for example, granular, sheet-like, or liquid.

[0031] The components of the sealing material 60 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 60 to the adhesive film 50 and enabling the electronic component 70 to be sealed more evenly. 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.

[0032] 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.

[0033] After the electronic components 70 are sealed with the sealing material 60, the sealing material 60 can be cured, for example, by heating at a temperature of 150° C. or less, to obtain a structure 100 in which the electronic components 70 are sealed.

[0034] (Other processes) The method for manufacturing an electronic device according to this embodiment may further include steps other than the preparation step (1), the air removal step (2), and the sealing step (3).

[0035] The method for manufacturing an electronic device according to this embodiment preferably further includes, after the air removal step (2), a moisture removal step of removing moisture from within the structure 100. This can reduce the amount of moisture within the structure 100, and can prevent moisture-related deterioration of the electronic component 70.

[0036] The method for removing moisture in the moisture removing step is not particularly limited, and any method may be used, such as drying by heating, drying under reduced pressure, or drying with a desiccant.

[0037] When drying is performed by heating, the heating temperature is not particularly limited, but from the viewpoint of more reliably removing moisture, it is preferably 70°C or higher, more preferably 80°C or higher, even more preferably 90°C or higher, and even more preferably 100°C or higher, and is, for example, less than 150°C.

[0038] When drying is performed by heating, the heating time is not particularly limited, but from the viewpoint of more reliably removing moisture, it is preferably 5 minutes or more, more preferably 10 minutes or more, even more preferably 20 minutes or more, even more preferably 30 minutes or more, even more preferably 1 hour or more, and is, for example, less than 3 hours.

[0039] The method for manufacturing an electronic device according to this embodiment may further include a first peeling step (4) after the sealing step (3), in which an external stimulus is applied to reduce the adhesive strength of the adhesive resin layer (B) to peel off the support substrate 80 from the structure 100, as shown in FIG. 3. The support substrate 80 can be easily removed from the adhesive film 50, for example, by heating the support substrate 80 to a temperature exceeding 150°C after sealing the electronic components 70, thereby reducing the adhesive strength of the adhesive resin layer (B).

[0040] In the manufacturing method of the electronic device according to this embodiment, as shown in FIG. 3, after the first peeling step (4), a second peeling step (5) may be further provided in which the adhesive film 50 is peeled off from the electronic component 70 to obtain the electronic device 200. Methods for peeling the adhesive film 50 from the electronic component 70 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.

[0041] The method for manufacturing an electronic device according to this embodiment may further include a step (6) of forming a wiring layer 310 and a bump 320 on the exposed surface of the obtained electronic device 200 to obtain the electronic device 300, as shown in FIG.

[0042] The wiring layer 310 includes pads (not shown) that are external connection terminals formed on the outermost surface, and wiring (not shown) that electrically connects the pads to the exposed electronic components 70. The wiring layer 310 can be formed by a conventionally known method, and may have a multi-layer structure.

[0043] Then, bumps 320 are formed on the pads of the wiring layer 310, and the electronic device 300 can be obtained. Examples of the bumps 320 include solder bumps and gold bumps. The solder bumps can be formed, for example, by placing solder balls on the pads that are external connection terminals of the wiring layer 310 and heating the solder to melt (reflow). The gold bumps can be formed by ball bonding, plating, Au ball transfer, or other methods.

[0044] Moreover, the method for manufacturing an electronic device according to this embodiment may further include a step (7) of dicing the electronic device 300 to obtain a plurality of electronic devices 400, as shown in FIG. The electronic device 300 can be diced by a known method.

[0045] The type of electronic device 300 is not particularly limited, but preferably includes a fan-out type package. In a fan-out type package, terminals can be spread 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.

[0046] 2. Adhesive film The adhesive film 50 according to this embodiment will be described below. FIG. 1 is a cross-sectional view that illustrates an example of the structure of an adhesive film 50 according to an embodiment of the present invention.

[0047] As shown in FIG. 1, the adhesive film 50 of this embodiment 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.

[0048] 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.

[0049] Next, each layer constituting the adhesive film 50 according to this embodiment will be described.

[0050] <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.

[0051] 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.

[0052] 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.

[0053] <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.

[0054] The adhesive resin (A1) constituting the adhesive resin layer (A) 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 (a) from the viewpoint of facilitating adjustment of the adhesive strength.

[0055] 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.

[0056] 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.

[0057] 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%.

[0058] 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.

[0059] 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.

[0060] 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).

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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).

[0068] 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.

[0069] 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.

[0070] 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.

[0071] <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. The adhesive resin layer (B) preferably has a function of decreasing its adhesive strength in response to an external stimulus, so that the adhesive film 50 can be easily peeled off from the support substrate 80 by applying an external stimulus. Here, examples of the adhesive resin layer (B) whose adhesive strength decreases with an external stimulus include a heat-peeling type adhesive resin layer whose adhesive strength decreases with heating, a radiation-peeling type adhesive resin layer whose adhesive strength decreases with radiation, etc. Among these, a heat-peeling type adhesive resin layer whose adhesive strength decreases with heating is preferred. Examples of heat-peelable adhesive resin layers include adhesive resin layers made 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.

[0072] The adhesive resin layer (B) preferably contains a thermally expandable adhesive, and it is more preferable that the thermally expandable adhesive is 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.

[0073] 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).

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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%.

[0080] 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.

[0081] 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.

[0082] 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).

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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).

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] <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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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]

[0101] A Adhesive resin layer B Adhesive resin layer 10 Base material layer 10A 1st side 10B 2nd side 50 Adhesive Film 60 Encapsulating material 70 Electronic Components 80 Support substrate 100 structures 110 Electronic component fixing parts 200 Electronic equipment 300 Electronic equipment 310 wiring layer 320 Bump 400 Electronic equipment

Claims

1. an adhesive film including a base layer, an adhesive resin layer (A) provided on a first surface side of the base layer and for temporarily fixing an electronic component, and an adhesive resin layer (B) provided on a second surface side of the base layer; an electronic component attached to the adhesive resin layer (A) of the adhesive film; a preparation step of preparing a structure including a support substrate attached to the adhesive resin layer (B) of the adhesive film; a sealing step of sealing the electronic component with a sealing material; A method for manufacturing an electronic device, comprising: The method for manufacturing an electronic device further comprises, between the preparing step and the sealing step, an air removal step of removing air pockets in the structure.

2. The method for manufacturing an electronic device according to claim 1 , wherein the structure is placed in a reduced pressure environment in the air removal step.

3. The method for manufacturing an electronic device according to claim 1 or 2, wherein in the air removal step, an electronic component fixing member is laminated on the electronic component of the structure.

4. The method for manufacturing an electronic device according to claim 3 , wherein the structure in which the electronic component fixing members are stacked is heated in the air removal step.

5. The method for manufacturing an electronic device according to claim 3 , wherein the structure in which the electronic component fixing members are stacked is pressurized in the air removal step.

6. The method for manufacturing an electronic device according to claim 3 , wherein the electronic component fixing member contains polyolefin.

7. The method for manufacturing an electronic device according to claim 3 , wherein the electronic component fixing member is in the form of a film.

8. The method for manufacturing an electronic device according to claim 1 or 2, wherein the heating temperature in the air removal step is less than 70°C.

9. The method for manufacturing an electronic device according to claim 1 or 2, wherein the heating time in the air removal step is less than 5 minutes.

10. The method for manufacturing an electronic device according to claim 1 or 2, further comprising a moisture removal step of removing moisture from the structure after the air removal step.

11. 3. The method for manufacturing an electronic device according to claim 1, wherein in the sealing step, the electronic components are sealed 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.

12. the adhesive resin layer (B) is a layer whose adhesive strength decreases in response to an external stimulus, 3. The method for manufacturing an electronic device according to claim 1, further comprising, after the sealing step, a first peeling step of applying an external stimulus to reduce the adhesive strength of the adhesive resin layer (B) and peeling the support substrate from the structure.

13. The method for manufacturing an electronic device according to claim 12 , further comprising, after the first peeling step, a second peeling step of peeling the adhesive film from the electronic component.

14. 3. The method for manufacturing an electronic device according to claim 1 or 2, wherein the adhesive resin constituting the adhesive resin layer (A) 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.

15. the adhesive resin layer (B) contains a thermally expandable adhesive, The method for manufacturing an electronic device according to claim 1 or 2, wherein the thermally expandable adhesive is an adhesive whose adhesive strength is reduced or lost when heated at a temperature exceeding 150°C.

16. The method for manufacturing an electronic device according to claim 1 or 2, wherein the sealing material includes an epoxy resin-based sealing material.

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

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