Method of manufacturing electronic device

Abstract

To provide a method of manufacturing an electronic device, with which an electronic device improved in reliability can be obtained.SOLUTION: There is provided a method of manufacturing an electronic device, which includes a step (a) of preparing a structure 100 and a step (b) of sealing an electronic component 70 by a sealing material 60. The structure includes: an adhesive film 50 including a base material layer 10, an adhesive resin layer (A) provided on a first surface 10A side of the base material layer 10 to temporarily fix an electronic component 70, and an adhesive resin layer (B) provided on a second surface 10B side of the base material layer 10; the electronic component 70 adhered to the adhesive resin layer (A) of the adhesive film 50; and a support substrate 80 adhered to the adhesive resin layer (B) of the adhesive film 50. The electronic component 70 includes a body part 110 and a bump part 120 provided at least one face of the body part 110. The bump part 120 is in contact with the adhesive resin layer (A) of the adhesive film 50. In the step (b), the body part 110 is sealed while a gap is provided between the body part 110 of the electronic component 70 and the adhesive resin layer (A).SELECTED DRAWING: Figure 3

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. Patent Document 1 describes a heat-resistant adhesive sheet for semiconductor device manufacturing that is attached when resin-sealing a substrate-less semiconductor chip, as a method for solving the problem of the chip not being held in place due to pressure during resin sealing and shifting from the designated position, or the problem of the package being damaged due to the sealing material hardening or heat causing the sealing material to become strongly adhesive to the chip surface when the heat-resistant adhesive sheet for semiconductor device manufacturing is peeled off, 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 before the resin sealing process is completed, so that the peel strength to the package is 2.0 N / 20 mm or less. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-134811 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to the research of the present inventors, it has become clear that when an electronic component having an uneven structure, such as a bump, is placed on an adhesive film and the electronic component is sealed with a sealing material, the surface of the electronic component that comes into contact with the adhesive film may not be sufficiently sealed, and sufficient protection by the sealing material may not be obtained.

[0006] The present invention has been made in view of the above circumstances, and provides a method for manufacturing an electronic device that can provide an electronic device with improved reliability. [Means for solving the problem]

[0007] The present inventors conducted extensive research to achieve the above object, and as a result, they discovered that by sealing the electronic component with a gap provided between the main body and the adhesive film, the surface of the electronic component that comes into contact with the adhesive film can be sufficiently sealed, and as a result, the reliability of the electronic device can be improved, and thus the present invention was completed.

[0008] According to the present invention, there is provided a method for manufacturing an electronic device as follows.

[0009] [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 step (a) of preparing a structure including a support substrate attached to the adhesive resin layer (B) of the adhesive film; (b) sealing the electronic component with a sealing material, The electronic component has a main body portion and bump portions provided on at least one surface of the main body portion, and the bump portions are in contact with the adhesive resin layer (A) of the adhesive film. In the step (b), a method for manufacturing an electronic device in which the main body portion of the electronic component is sealed with a gap provided between the main body portion of the electronic component and the adhesive resin layer (A). [2] In the step (b), the method for manufacturing an electronic device according to [1], wherein one surface of the electronic component that is in contact with the adhesive resin layer (A) is sealed. [3] In the step (b), the method for manufacturing an electronic device according to [1] or [2], wherein the entire surface of the electronic component is sealed at once. [4] The electronic component has a rectangular parallelepiped shape, and in the step (b), the method for manufacturing an electronic device according to any one of [1] to [3], wherein the six surfaces of the rectangular parallelepiped shape are sealed at once. [5] The method for manufacturing an electronic device according to any one of [1] to [4], wherein the thickness of the adhesive resin layer (A) is 1 μm or more and 100 μm or less. [6] When the height of the bump portion of the electronic component is H and the thickness of the adhesive resin layer (A) is T, the method for manufacturing an electronic device according to any one of [1] to [5], which satisfies the relationship of 1.1 < H / T < 5.0. [7] The method for manufacturing an electronic device according to any one of [1] to [6], wherein the adhesive film further includes a concavo-convex absorbing resin layer (C) between at least one of the base material layer and the adhesive resin layer (A) and between the base material layer and the adhesive resin layer (B). [8] Before the step (b), the method for manufacturing an electronic device according to [7], further including a step of crosslinking the concavo-convex absorbing resin layer (C) by applying at least one kind of energy selected from the group consisting of light energy and thermal energy to the concavo-convex absorbing resin layer (C) in the structure. [9] The manufacturing method of the electronic device according to [7] or [8], wherein the thickness of the concavo-convex absorbent resin layer (C) is 5 μm or more and 400 μm or less.

[10] The manufacturing method of the electronic device according to any one of [7] to [9], when the height of the bump portion of the electronic component is H, the thickness of the adhesive resin layer (A) is T, and the thickness of the concavo-convex absorbent resin layer (C) is I, satisfying the relationship of 1.1 < H / (T + I) < 5.0.

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

[10] , wherein the adhesive film further includes a hard layer (D), or the base material layer is a hard layer.

[12] The manufacturing method of the electronic device according to any one of [1] to

[11] , wherein the hard layer (D) or the base material layer includes one or more selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyimide, aramid, polyether ketone, polyether sulfone, and polyphenylene sulfide.

[13] The manufacturing method of the electronic device according to any one of [1] to

[12] , wherein the Shore D hardness of the hard layer (D) or the base material layer by the D-type Shore of ASTM D-2240 is 55 or more.

[14] The manufacturing method of the electronic device according to any one of [1] to

[13] , wherein the adhesive resin layer (B) is a layer whose adhesive force decreases due to external stimuli.

[15] The manufacturing method of the electronic device according to any one of [1] to

[14] , wherein the adhesive resin layer (A) includes 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.

[16] The manufacturing method of the electronic device according to any one of [1] to

[15] , wherein the encapsulant includes an epoxy resin-based encapsulant.

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

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

[0010] According to the present invention, it is possible to provide a manufacturing method for an electronic device that can obtain an electronic device with improved reliability. [Brief description of the drawings]

[0011] [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] 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 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] 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 5] FIG. 1 is a diagram for explaining a sealing defect of an electronic component called a standoff. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. In addition, the drawings are schematic views, and the actual dimensional ratios are not necessarily the same. In the present specification, unless otherwise specified, the expression "A to B" regarding a numerical range means greater than or equal to A and less than or equal to B. For example, 1 to 5% means greater than or equal to 1% and less than or equal to 5%. In the present specification, "(meth)acrylic" means acrylic, methacrylic, or both acrylic and methacrylic.

[0013] 1. Manufacturing method of electronic device First, a method for manufacturing an electronic device according to the present embodiment will be described. Figures 3 and 4 are cross-sectional views that typically show an example of a method for manufacturing an electronic device according to the present embodiment. The method for manufacturing an electronic device according to this embodiment includes at least the following two steps. (a) A step of preparing a structure 100 including a base layer 10, an adhesive film 50 including an adhesive resin layer (A) provided on a 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 a 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. (b) A process of sealing the electronic component 70 with the sealing material 60 Moreover, electronic component 70 according to this embodiment has main body portion 110 and bump portion 120 provided on at least one surface of main body portion 110, and bump portion 120 is in contact with adhesive resin layer (A) of adhesive film 50. In the step (b), the main body 110 of the electronic component 70 is sealed with a gap provided between the main body 110 and the adhesive resin layer (A).

[0014] As described above, the inventors' research has revealed that when an electronic component having an uneven structure, such as a bump, is placed on an adhesive film and the electronic component is sealed with a sealing material, the surface of the electronic component that comes into contact with the adhesive film may not be sufficiently sealed, and sufficient protection by the sealing material may not be obtained. The present inventors have conducted extensive research to achieve the above object, and as a result, have found for the first time that by sealing the electronic component with a gap provided between the main body and the adhesive film, the surface of the electronic component that comes into contact with the adhesive film can be sufficiently sealed, and as a result, the reliability of the electronic device can be improved. That is, according to the manufacturing method of the electronic device of this embodiment, by sealing the main body 110 of the electronic component 70 while leaving a gap between the main body 110 and the adhesive resin layer (A), it is possible to seal the surface of the electronic component 70 that comes into contact with the adhesive resin layer (A), thereby improving the reliability of the electronic device. As described above, according to the method for manufacturing an electronic device according to this embodiment, it is possible to improve the reliability of the electronic device.

[0015] Each step of the method for manufacturing an electronic device according to this embodiment will be described below.

[0016] ((a) 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.

[0017] 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 may be attached onto the adhesive resin layer (B), and the protective film may be peeled off, and the exposed surface of the adhesive resin layer (B) may be attached 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.

[0018] Next, the electronic component 70 is placed on the adhesive resin layer (A) of the adhesive film 50 attached to the support substrate 80 so that the bump portion 120 is in contact with the adhesive resin layer (A), thereby obtaining the structure 100. 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. Electronic component 70 has a shape in which main body 110 has at least one surface, and bump portion 120 is provided on at least one surface of main body 110, so that the surface on which bump portion 120 is provided has an uneven structure. The shape of electronic component 70 is not limited to a specific shape, but may be a rectangular parallelepiped. When electronic component 70 has a rectangular parallelepiped shape, bump portion 120 is provided on at least one of six faces of main body 110. Furthermore, the bump portion is bonded to an electrode formed on the mounting surface, for example, when mounting an electronic device on the mounting surface, thereby forming an electrical connection between the electronic device and the mounting surface (the mounting surface of a printed circuit board, etc.). Examples of the bump portion include bump electrodes such as ball bumps, printed bumps, stud bumps, plated bumps, pillar bumps, etc. These bump electrodes may be used alone or in combination of two or more kinds. The metal species constituting the bump electrode is not particularly limited, and examples thereof include silver, gold, copper, tin, lead, bismuth, and alloys thereof. These metal species may be used alone or in combination of two or more.

[0019] ((b) Sealing process) Next, the electronic components 70 are encapsulated with the encapsulant 60 . The electronic component 70 is 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 component 70. When the adhesive resin layer (B) of the adhesive film 50 contains at least one selected from a gas-generating component and heat-expandable microspheres, the temperature for curing the sealing material 60 is preferably within a range not exceeding the temperature at which gas is generated or the temperature at which the heat-expandable microspheres thermally expand. The form of the sealing material 60 is not particularly limited, but may be, for example, granular, sheet-like, or liquid.

[0020] In the sealing process, as shown in Fig. 3, the main body 110 of the electronic component 70 is sealed with a gap between the main body 110 and the adhesive resin layer (A). In this way, the surface of the electronic component 70 that contacts the adhesive resin layer (A) can be sealed, and as a result, the reliability of the electronic device can be improved. In order to further improve the reliability of the electronic device, in the sealing step (b), it is preferable to seal one surface of the electronic component 70 that is in contact with the adhesive resin layer (A), it is more preferable to seal the entire surface of the electronic component 70 at once, and when the electronic component 70 has a rectangular parallelepiped shape, it is preferable to seal all six surfaces of the electronic component 70 at once.

[0021] Furthermore, the size of the gap between the main body portion 110 of the electronic component 70 and the adhesive resin layer (A) is not particularly limited, but from the viewpoint of further improving the reliability of the electronic device, when the height of the bump portion 120 is H and the thickness of the adhesive resin layer (A) is T, H / T is preferably greater than 1.1, more preferably 1.3 or more, even more preferably 1.5 or more, even more preferably 1.7 or more, even more preferably 1.9 or more, even more preferably 2.0 or more, and preferably less than 5.0, more preferably 4.5 or less, even more preferably 4.0 or less, even more preferably 3.7 or less, even more preferably 3.3 or less, and even more preferably 3.0 or less.

[0022] The sealing material 60 is not particularly limited, but preferably contains one or more types selected from an epoxy resin-based sealing material using an epoxy resin and a silicone resin-based sealing material using a silicone resin, and more preferably contains an epoxy resin-based sealing material, and even more preferably contains a liquid epoxy resin-based sealing material, since this improves the affinity of the sealing material 60 to the adhesive film 50 and enables the electronic component 70 to be sealed 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. Examples of such silicone resin-based sealing materials that can be used include KMC-8400 manufactured by Shin-Etsu Chemical Co., Ltd., and TSE3033 and TSE3251 manufactured by Momentive Performance Materials Japan, Inc.

[0023] Examples of the sealing method include transfer molding, injection molding, compression molding, cast molding, etc. After sealing the electronic component 70 with the sealing material 60, the sealing material 60 is cured by heating at a temperature of, for example, 150° C. or less, to obtain the structure 100 in which the electronic component 70 is sealed.

[0024] ((c) 1st peeling process) In the manufacturing method of the electronic device according to this embodiment, as shown in FIG. 4(c), after the (b) sealing step, a first peeling step may be further provided 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. The support substrate 80 can be easily removed from the adhesive film 50, for example, by sealing the electronic components 70 and then heating the support substrate 80 to a temperature exceeding 150°C or a temperature exceeding 170°C to reduce the adhesive strength of the adhesive resin layer (B).

[0025] ((d) Second peeling step) In the manufacturing method for an electronic device according to this embodiment, as shown in FIG. 4(d), after the first peeling step (c), a second peeling step 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.

[0026] (Other processes) The method for manufacturing an electronic device according to this embodiment may further include a step (e) 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. 4(e).

[0027] 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.

[0028] 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.

[0029] Moreover, the method for manufacturing an electronic device according to this embodiment may further include a step (f) of dicing the electronic device 300 to obtain a plurality of electronic devices 400, as shown in FIG. 4(f). The electronic device 300 can be diced by a known method.

[0030] 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.

[0031] 2. Adhesive film The adhesive film 50 according to this embodiment will be described below. 1 and 2 are cross-sectional views that diagrammatically show an example of the structure of an adhesive film 50 according to an embodiment of the present invention.

[0032] 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.

[0033] 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.

[0034] Next, each layer constituting the adhesive film 50 according to this embodiment will be described.

[0035] <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 the group consisting of 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 preventing the electronic component 70 from sinking into the adhesive film 50, thereby making it easier to secure a gap between the main body 110 of the electronic component 70 and the adhesive resin layer (A) in the sealing process (b), and improving the reliability of the electronic device, one or more types selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyimide, aramid, polyether ketone, polyether sulfone, and polyphenylene sulfide are preferred, and one or more types selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate are more preferred. In addition, by preventing the electronic component 70 from sinking into the adhesive film 50, it is possible to prevent poor sealing of the electronic component 70A, known as standoff 90 (where part of the side of the electronic component 70A is not sealed), as well as wrinkles on the surface of the sealing material after sealing, as shown in Figure 5(d'). The Shore D hardness of the base layer 10 according to ASTM D-2240 Shore D hardness is preferably 53 or more, more preferably 55 or more, and even more preferably 60 or more, from the viewpoint of preventing the electronic component 70 from sinking into the adhesive film 50, thereby facilitating securing a gap between the main body 110 of the electronic component 70 and the adhesive resin layer (A) in the sealing step (b), and improving the reliability of the electronic device. The upper limit of the Shore D hardness is not particularly limited, but is, for example, 85 or less.

[0036] 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.

[0037] 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.

[0038] <Adhesive resin layer (A)> The adhesive resin layer (A) is a layer provided on one surface side of the base layer 10. The adhesive resin layer (A) is a layer for temporarily fixing an electronic component by contacting the surface of the electronic component when the electronic component is sealed with a sealing material in a manufacturing process of an electronic device, for example.

[0039] The adhesive resin layer (A) preferably contains an adhesive resin (A1). The adhesive resin (A1) preferably contains one or more selected from the group consisting of (meth)acrylic adhesive resins (a), silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins. Among these, the (meth)acrylic adhesive resin (a) is preferred from the viewpoint of easily adjusting the adhesive strength.

[0040] The adhesive resin layer (A) may be a radiation-crosslinked adhesive resin layer whose adhesive strength can be reduced by radiation. When the radiation-crosslinked adhesive resin layer is irradiated with radiation, crosslinking occurs and the adhesive strength is significantly reduced, making it easier to peel the adhesive film 50 from the electronic component. Examples of radiation include ultraviolet rays, electron beams, and infrared rays. The radiation crosslinkable adhesive resin layer is preferably an ultraviolet crosslinkable adhesive resin layer.

[0041] 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.

[0042] 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.

[0043] The monomer (a1) forming the (meth)acrylic acid alkyl ester monomer unit (a1) includes a (meth)acrylic acid alkyl ester having an alkyl group with about 1 to 12 carbon atoms. A (meth)acrylic acid alkyl ester having an alkyl group with 1 to 8 carbon atoms is preferable. Specific examples include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, etc. 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%.

[0044] Examples of the monomer (a2) forming the monomer unit (a2) having a functional group capable of reacting 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, acrylate, methacrylate, 2-hydroxyethyl acrylate, methacrylate, acrylamide, methacrylamide, tertiary butylaminoethyl acrylate, tertiary butylaminoethyl methacrylate, etc. Preferred are acrylic acid, methacrylic acid, acrylate, 2-hydroxyethyl acrylate, methacrylate, acrylamide, methacrylamide, etc. 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.

[0045] 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 monomer (a1), the monomer (a2) and the bifunctional monomer (a3), and also acts as an emulsifier in the case of emulsion polymerization.

[0046] Examples of monomers that form 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).

[0047] In the (meth)acrylic adhesive resin (a) according to this embodiment, the content of the bifunctional monomer unit (a3) ​​is preferably from 0.1 to 30% by mass, more preferably from 0.1 to 20% by mass, even more preferably from 0.1 to 15% by mass, and still more preferably from 0.1 to 5% by mass, when the sum of all monomer units in the (meth)acrylic adhesive resin (a) is taken as 100% by mass.

[0048] 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 20% by mass, even more preferably from 0.1% by mass to 15% by mass, and still more 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.

[0049] 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.

[0050] 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.

[0051] When polymerization is performed by emulsion polymerization, among these radical polymerization initiators, preferred are 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. 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 even more preferred.

[0052] 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 can be used to adjust the adhesive strength and cohesive strength by reacting with the functional groups of the adhesive resin (A1). 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 tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate; tetrafunctional epoxy-based 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 use one or more compounds selected from the group consisting of epoxy compounds, isocyanate compounds, and aziridine compounds.

[0053] 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).

[0054] 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 even more 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.

[0055] The adhesive resin layer (A) may be a single layer or multiple layers. The thickness of the adhesive resin layer (A) is not particularly limited, but from the viewpoint of facilitating the securing of a gap between the main body 110 of the electronic component 70 and the adhesive resin layer (A) in the sealing process (b) and improving the reliability of the electronic device, the thickness is preferably 100 μm or less, more preferably 75 μm or less, even more preferably 50 μm or less, even more preferably 40 μm or less, even more preferably 30 μm or less, and preferably 1 μm or more.

[0056] 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 aqueous emulsion coating liquid is preferable. Examples of the aqueous emulsion coating liquid include a coating liquid in which a (meth)acrylic adhesive resin (a), a silicone adhesive resin, a urethane adhesive resin, an olefin adhesive resin, a styrene adhesive resin, or the like is dispersed in water. A pressure-sensitive adhesive coating solution dissolved in an organic solvent may be used. 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.

[0057] 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. It is more preferable to dry the coated adhesive 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 adhesive coating liquid may be heated at 40 to 80°C for about 5 to 300 hours after drying is completed.

[0058] 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.

[0059] <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) is preferably a layer whose adhesive strength decreases in response to an external stimulus, so that the adhesive film 50 can be easily peeled off from the supporting substrate by applying an external stimulus. Here, examples of the adhesive resin layer (B) whose adhesive strength is reduced by an external stimulus include a heat-peeling type adhesive resin layer whose adhesive strength is reduced by heating, a light-peeling type adhesive resin layer whose adhesive strength is reduced by light such as radiation, etc. That is, examples of the external stimulus include light energy and heat energy, etc. Examples of the heat-peelable adhesive resin layer include adhesive resin layers composed of a heat-expandable adhesive that contains an adhesive resin (B1) and further contains a gas-generating component, a heat-expandable adhesive that contains 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.

[0060] In this embodiment, the thermally expandable adhesive used in the adhesive resin layer (B) is an adhesive whose adhesive strength is reduced or lost when heated, for example, above 150° C., preferably above 170° C. For example, a material can be selected that does not peel off at 150° C. or below or 170° C. or below, but peels off at 150° C. or above 170° C., and it is preferable that the adhesive film 50 has an adhesive strength sufficient to prevent it from peeling off from the supporting substrate during the manufacturing process of the electronic device. Here, the decrease or loss of adhesive strength due to heating at over 150°C or over 170°C can be evaluated by, for example, 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 of over 150°C or over 170°C for 2 minutes, and then measuring the peel strength from the stainless steel plate. The specific heating temperature when heating at a temperature of over 150°C or over 170°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 in which 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.

[0061] 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).

[0062] 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.

[0063] 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, but 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 or the temperature at which the heat-expandable microspheres expand is greater than 150°C or greater than 170°C.

[0064] Examples of the adhesive resin (B1) constituting the thermally expandable adhesive agent include (meth)acrylic adhesive resin (b), urethane resin, silicone resin, polyolefin resin, polyester resin, polyamide resin, fluorine resin, styrene-diene block copolymer resin, etc. Among these, (meth)acrylic adhesive resin (b) is preferred.

[0065] 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.

[0066] 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.

[0067] 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%.

[0068] 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, acrylate, methacrylate, 2-hydroxyethyl acrylate, methacrylate, acrylamide, methacrylamide, tertiary butylaminoethyl acrylate, tertiary butylaminoethyl methacrylate, etc. Preferred are acrylic acid, methacrylic acid, acrylate, 2-hydroxyethyl acrylate, methacrylate, acrylamide, methacrylamide, etc. 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.

[0069] 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 monomer (b1), the monomer (b2) and the bifunctional monomer (b3), and also acts as an emulsifier in the case of emulsion polymerization.

[0070] Examples of monomers that form 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., manufactured by Nippon Oil & Fats Co., Ltd.; trade names: PDP-200, PDP-400, ADP-200, ADP-400), tetramethylene glycol type (e.g., manufactured by Nippon Oil & Fats Co., Ltd.; trade names: ADT-250, ADT-850), and mixtures thereof (e.g., manufactured by Nippon Oil & Fats Co., Ltd.; trade names: ADET-1800, ADPT-4000).

[0071] In the (meth)acrylic adhesive resin (b) according to this embodiment, the content of the bifunctional monomer unit (b3) is preferably from 0.1 to 30% by mass, more preferably from 0.1 to 20% by mass, even more preferably from 0.1 to 15% by mass, and even more 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.

[0072] 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 20% by mass, even more preferably from 0.1% by mass to 15% by mass, and even more 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.

[0073] 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.

[0074] 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.

[0075] When polymerization is performed by emulsion polymerization, among these radical polymerization initiators, preferred are 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. 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 even more preferred.

[0076] 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 tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate; tetrafunctional epoxy-based 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 use one or more compounds selected from the group consisting of epoxy compounds, isocyanate compounds, and aziridine compounds.

[0077] 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).

[0078] 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 having a softening point of 100°C or higher. Specific examples of the tackifier resin include rosin-based resins such as rosin-based derivatives treated with 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; petroleum resins obtained by treating these natural rosins with hydrogenation, disproportionation, polymerization, maleinization, and the like; and coumarone-indene resins.

[0079] 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 even more preferred. Use of a tackifier resin having a softening point in the above range not only reduces contamination and adhesive residue on the support substrate, but also enables further improvement in adhesion to the support substrate in a working environment. Furthermore, use of a polymerized rosin ester-based tackifier resin as the tackifier resin not only reduces contamination and adhesive residue on the support substrate, but also improves adhesion to the support substrate in an environment of 80 to 130° C., 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.

[0080] 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.

[0081] 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 even more 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 even more preferably 95% by mass or more, when the entire adhesive resin layer (B) is taken as 100% by mass.

[0082] The adhesive resin layer (B) may be a single layer or a multilayer. For example, by laminating two or more layers having different degrees of expansion by heating to form the adhesive resin layer (B), the adhesiveness / thermal peelability can be changed between one side and the other side of the adhesive resin layer (B). The thickness of the adhesive resin layer (B) is not particularly limited, but is preferably, for example, from 3 μm to 300 μm, and more preferably from 20 μm to 150 μm.

[0083] 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.

[0084] <Roughness-absorbing resin layer (C)> As shown in FIG. 2, the adhesive film 50 of this embodiment preferably further comprises an unevenness-absorbing resin layer (C) between the base layer 10 and the adhesive resin layer (A) or between the base layer 10 and the adhesive resin layer (B), and more preferably further comprises an unevenness-absorbing resin layer (C) between the base layer 10 and the adhesive resin layer (A). The unevenness-absorbing resin layer (C) is a layer provided for the purpose of improving the conformability of the adhesive film 50 to the surface of the electronic component on which the uneven structure is formed, and improving the adhesion between the adhesive film 50 and the electronic component 70 having the uneven structure. Furthermore, it is preferable that the unevenness-absorbing resin layer (C) is crosslinkable by at least one type of energy selected from the group consisting of light energy and thermal energy. The elastic modulus of the unevenness-absorbing resin layer (C) can be increased by crosslinking and curing the unevenness-absorbing resin layer (C). That is, in the manufacturing method of the electronic device according to the present embodiment, it is preferable to further include a step of crosslinking the unevenness-absorbing resin layer (C) by applying at least one type of energy selected from the group consisting of light energy and thermal energy to the unevenness-absorbing resin layer (C) in the structure 100 before the sealing step (b). This makes it possible to suppress the electronic component 70 from sinking into the adhesive film 50 in the sealing step (b), and to easily ensure a gap between the main body part 110 of the electronic component 70 and the adhesive resin layer (A) in the sealing step (b). In addition, by preventing the electronic component 70 from sinking into the adhesive film 50, it is possible to prevent poor sealing of the electronic component 70A, known as standoff 90 (where part of the side of the electronic component 70A is not sealed), as well as wrinkles on the surface of the sealing material after sealing, as shown in Figure 5(d').

[0085] The resin constituting the unevenness-absorbing resin layer (C) is not particularly limited as long as it exhibits unevenness absorption, and is preferably, for example, a thermoplastic resin, more preferably one or more selected from the group consisting of polyolefin resins, polystyrene resins, and (meth)acrylic resins. In addition, the resin constituting the unevenness-absorbing resin layer (C) is preferably a resin having a Shore D hardness of preferably 50 or less, more preferably 40 or less according to ASTM D-2240 Shore D hardness. Even when the resin constituting the irregularity-absorbing resin layer (C) is not a thermoplastic resin, it is preferable that the resin has the same irregularity-absorbing properties as described above.

[0086] The unevenness-absorbing resin layer (C) preferably contains a resin, a crosslinking agent, and at least one initiator selected from a photoinitiator and a thermal initiator, where the photoinitiator is a compound that generates an active chemical species by light, and the thermal initiator is a compound that generates an active chemical species by heat. By including these components in the unevenness-absorbing resin layer (C), the unevenness-absorbing resin layer (C) can be crosslinked more effectively by at least one of light energy and heat energy, and the elastic modulus of the unevenness-absorbing resin layer (C) can be further improved. This makes it possible to suppress the unevenness-absorbing resin layer (C) from being softened by heat in the process of sealing the electronic component 70 with the sealing material 60, and as a result, it is possible to further suppress the electronic component 70 from sinking into the adhesive film 50 due to the pressure of the sealing material 60. Depending on the chemical structure and reactivity of the resin and crosslinking agent, the unevenness-absorbing resin layer (C) may be crosslinked (cured) by at least one of light energy and heat energy even if it does not necessarily contain an initiator.

[0087] The resin constituting the irregularity-absorbing resin layer (C) is not particularly limited, but preferable examples thereof include the resins explained as the adhesive resin (B1) in the adhesive resin layer (B) described above. The resin constituting the unevenness-absorbing resin layer (C) is not particularly limited, and examples thereof include olefin resins such as ethylene-α-olefin copolymers containing ethylene and an α-olefin having 3 to 20 carbon atoms, high-density ethylene resins, low-density ethylene resins, medium-density ethylene resins, very low-density ethylene resins, linear low-density polyethylene (LLDPE) resins, propylene (co)polymers, 1-butene (co)polymers, 4-methylpentene-1 (co)polymers, ethylene-cyclic olefin copolymers, ethylene-α-olefin-cyclic olefin copolymers, ethylene-α-olefin-non-conjugated polyene copolymers, ethylene-α-olefin-conjugated polyene copolymers, ethylene-aromatic vinyl copolymers, and ethylene-α-olefin-aromatic vinyl copolymers; ethylene-carboxylic acid anhydride copolymers such as ethylene-unsaturated carboxylic anhydride copolymers and ethylene-α-olefin-unsaturated carboxylic anhydride copolymers; ethylene-epoxy copolymers such as ethylene-epoxy-containing unsaturated compound copolymers and ethylene-α-olefin-epoxy-containing unsaturated compound copolymers; ethylene-(meth)acrylate copolymers, ethylene-(meth)acryloyl acetate ... ethylene-(meth)acrylic acid ester copolymers such as methyl acrylate copolymer, ethylene-propyl (meth)acrylate copolymer, ethylene-butyl (meth)acrylate copolymer, ethylene-hexyl (meth)acrylate copolymer, ethylene-2-hydroxyethyl (meth)acrylate copolymer, ethylene-2-hydroxypropyl (meth)acrylate copolymer, and ethylene-glycidyl (meth)acrylate copolymer; ethylene-ethylenically unsaturated acid copolymers such as ethylene-(meth)acrylic acid copolymer, ethylene-maleic acid copolymer, ethylene-fumaric acid copolymer, and ethylene-crotonic acid copolymer; ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer, ethylene-vinyl butyrate copolymer, and ethylene-vinyl stearate copolymer; ethylene-styrene copolymer; unsaturated carboxylic acid ester (co)polymers such as (meth)acrylic acid ester (co)polymers; ionomer resins such as ethylene-metal acrylate copolymer and ethylene-metal methacrylate copolymer; urethane-based resins; silicone-based resins; acrylic acid-based resins; methacrylic acid-based resins;Cyclic olefin (co)polymers; α-olefins, aromatic vinyl compounds, aromatic polyene copolymers; ethylene, α-olefins, aromatic vinyl compounds; aromatic polyene copolymers; ethylene, aromatic vinyl compounds, aromatic polyene copolymers; styrene-based resins; acrylonitrile, butadiene, styrene copolymers; styrene, conjugated diene copolymers; acrylonitrile, styrene copolymers; acrylonitrile, ethylene, α-olefins, non-conjugated polyene, styrene copolymers; acrylonitrile, ethylene, α-olefins, conjugated polyene, styrene copolymers; methacrylic acid, styrene copolymers; ethylene terephthalate resins; fluororesins; polyester carbonates; polyvinyl chloride; polyvinylidene chloride; polyolefin-based thermoplastic elastomers; polystyrene-based thermoplastic elastomers; polyurethane-based thermoplastic elastomers; 1,2-polybutadiene-based thermoplastic elastomers; trans-polyisoprene-based thermoplastic elastomers; chlorinated polyethylene-based thermoplastic elastomers; liquid crystal polyesters; polylactic acid, etc., may be used. The irregularity-absorbing resin layer (C) may contain only one resin, or may contain two or more resins.

[0088] The crosslinking agent contained in the unevenness-absorbing resin layer (C) is not particularly limited, and may be any agent that undergoes a crosslinking reaction due to a chemical species generated from an initiator. Examples of the crosslinking agent include polyfunctional (meth)acrylate compounds and isocyanate compounds, and more specifically, examples thereof include urethane (meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, and the like; and isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate. Examples of the crosslinking agent include various monomers or oligomers such as urethane compounds, polyether compounds, polyester compounds, polycarbonate compounds, and polybutadiene compounds. The amount of the crosslinking agent is, for example, 5 to 500 parts by mass, preferably 40 to 150 parts by mass, per 100 parts by mass of the resin (base polymer) such as the (meth)acrylic polymer in the roughness-absorbing resin layer (C).

[0089] The unevenness-absorbing resin layer (C) may contain one or more of the crosslinking agents (A2) contained in the adhesive resin layer (A). Specifically, the unevenness-absorbing resin layer (C) may contain an isocyanate-based compound. When such a crosslinking agent is used, the amount is, for example, 0.01 parts by mass or more and 5 parts by mass or less, preferably 0.01 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the resin (base polymer) in the unevenness-absorbing resin layer (C).

[0090] The photoinitiator contained in the roughness-absorbing resin layer (C) is not particularly limited as long as it is capable of crosslinking the resin and / or crosslinking agent in the roughness-absorbing resin layer (C) by light energy. The chemical species generated from the photoinitiator may be appropriately selected based on the functional groups of the resin and / or crosslinker. The chemical species generated from the photoinitiator is typically a radical or a cation.

[0091] As the photoinitiator, an alkylphenone-based photoinitiator, an acetophenone-based photoinitiator, an oxime ester-based photoinitiator, a benzoin ether-based photoinitiator, an acylphosphine oxide-based photoinitiator, an α-ketol-based photoinitiator, an aromatic sulfonyl chloride-based photoinitiator, a photoactive oxime-based photoinitiator, a benzoin-based photoinitiator, a benzyl-based photoinitiator, a benzophenone-based photoinitiator, a thioxanthone-based photoinitiator, etc. can be used. The photoinitiator can be used alone or in appropriate combination of two or more. Among these, it is preferable to include an alkylphenone-based photoinitiator from the viewpoint of high reactivity and low sublimation.

[0092] Specific examples of alkylphenone photoinitiators include 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-propan-1-one, 2-hydroxy-1-{[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, and the like. Specific examples of acetophenone-based photoinitiators include 1-hydroxycyclohexyl-phenyl-ketone, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, methoxyacetophenone, and the like. Specific examples of oxime ester photoinitiators include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-2-(o-benzoyloxime), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(o-acetyloxime), and the like. Specific examples of benzoin ether photoinitiators include benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, and benzoin isobutyl ether, and substituted benzoin ethers such as anisole methyl ether. Specific examples of acylphosphine oxide photoinitiators include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and the like. Specific examples of α-ketol photoinitiators include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one, and the like. A specific example of the aromatic sulfonyl chloride photoinitiator is 2-naphthalenesulfonyl chloride. Specific examples of photoactive oxime-based photoinitiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime, and the like. Specific examples of benzoin-based photoinitiators include benzoin. Specific examples of benzyl-based photoinitiators include benzyl and the like. Specific examples of benzophenone-based photoinitiators include benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexyl phenyl ketone. Specific examples of thioxanthone-based photoinitiators include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

[0093] As the photoinitiator, a photoinitiator that absorbs light having a wavelength of 300 nm or more (for example, light having a wavelength of 300 nm or more and 500 nm or less) to generate radicals can be preferably used. The photoinitiator can be used alone or in appropriate combination of two or more kinds.

[0094] The content of the photoinitiator in the unevenness-absorbing resin layer (C) is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, based on 100 parts by mass of the resin (base polymer) such as the (meth)acrylic polymer in the unevenness-absorbing resin layer (C). From the viewpoint of storage stability, the content is preferably 7 parts by mass or less, and more preferably 3 parts by mass or less.

[0095] The thermal initiator contained in the unevenness-absorbing resin layer (C) is not particularly limited as long as it is capable of crosslinking the resin and / or crosslinking agent in the unevenness-absorbing resin layer (C) by thermal energy. The chemical species generated from the thermal initiator may be appropriately selected based on the functional groups of the resin and / or crosslinker. The chemical species generated from the thermal initiator is typically a radical or a cation.

[0096] Examples of thermal initiators include aromatic ketones, onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having carbon-halogen bonds, and azo compounds. These may be used alone or in combination of two or more. Among these, azo compounds and organic peroxides are preferred from the viewpoints of availability and ease of handling, and organic peroxides are more preferred.

[0097] Commercially available thermal initiators include V-70, V-65, V-601, V-59, V-40, VF-096, V-30, VAm-110, and VAm-111 (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), Niper BW, Niper BMT, Peroyl TCP, Peroyl L, Peroyl 355, Peroyl SA, Perhexa HC, Perbutyl 355, Perbutyl D, Perbutyl L, Perbutyl ND, Perocta O, Perhexyl D, Perhexyl O, and Perhexyl PV (all manufactured by NOF Corp.), Trigonox 36-C75, Laurox, Perkadox L-W75, Perkadox CH-50L, Trigonox TMBH, Kayacumene H, Kayabutyl H-70, Perkadox BC-FF, and Kayahexyl PV (all manufactured by NOF Corp.). Examples of such compounds include SA AD, Perkadox 14, Kayabutyl C, Kayabutyl D, Perkadox 12-XL25, Trigonox 22-N70 (22-70E), Trigonox D-T50, Trigonox 423-C70, Kayaester CND-C70, Trigonox 23-C70, Trigonox 257-C70, Kayaester P-70, Kayaester TMPO-70, Trigonox 121, Kayaester O, Kayaester HTP-65W, Kayaester AN, Trigonox 42, Trigonox F-C50, Kayabutyl B, Kayacarvone EH, Kayacarvone I-20, Kayacarvone BIC-75, Trigonox 117, and Kayalene 6-70 (all manufactured by Kayaku Akzo Co., Ltd.).

[0098] The content of the thermal initiator in the unevenness-absorbing resin layer (C) is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, based on 100 parts by mass of the resin (base polymer) such as the (meth)acrylic polymer in the unevenness-absorbing resin layer (C). From the viewpoint of storage stability, the content is preferably 7 parts by mass or less, and more preferably 3 parts by mass or less.

[0099] In the adhesive film 50 according to the present embodiment, the lower limit of the storage modulus E' at 60°C of the unevenness-absorbing resin layer (C) before crosslinking is 1.0 × 10 to further suppress sinking of the electronic component 70 into the adhesive film 50 in the sealing step (b) of the electronic component 70. 3 Pa or more is preferable, 5.0×10 3 Pa or more is more preferable. In addition, in the pressure-sensitive adhesive film 50 according to the present embodiment, the upper limit of the storage elastic modulus E' at 60°C of the unevenness-absorbing resin layer (C) before crosslinking is 1.0 × 10 to effectively absorb the unevenness on the surface of the electronic component 70 and prevent the unevenness absorption from deteriorating over time due to springback of the resin. 6 Pa or less is preferable, and 5.0×10 5 Pa or less is more preferable. The storage modulus E' at 60°C of the unevenness-absorbing resin layer (C) before crosslinking can be controlled within the above range, for example, by controlling the types and blending ratios of each component constituting the unevenness-absorbing resin layer (C).

[0100] In the pressure-sensitive adhesive film 50 according to the present embodiment, the lower limit of the storage modulus E' at 125°C of the unevenness-absorbing resin layer (C') obtained by crosslinking the unevenness-absorbing resin layer (C) is 1.0 × 10 to further suppress sinking of the electronic component 70 into the pressure-sensitive adhesive film 50 in the sealing step (b) of the electronic component 70. 6 Pa or more is preferable, 5.0×10 6 Pa or more is more preferable. In the pressure-sensitive adhesive film 50 according to the present embodiment, the upper limit of the storage modulus E′ at 125° C. of the irregularity-absorbing resin layer (C′) is set to 1.0×10 9 Pa or less is preferable, and 1.0×10 8 Pa or less is more preferable. The storage modulus E' of the unevenness-absorbing resin layer (C') at 125°C can be controlled within the above range, for example, by controlling the types and blending ratios of each component constituting the unevenness-absorbing resin layer (C). Here, whether the crosslinking treatment of the unevenness-absorbing resin layer (C) is completed can be determined, for example, by determining the point at which the storage modulus E' of the unevenness-absorbing resin layer (C) no longer increases even after the crosslinking treatment.

[0101] The thickness of the unevenness-absorbing resin layer (C) is not particularly limited, but from the viewpoint of making it easier to secure a gap between the main body 110 of the electronic component 70 and the adhesive resin layer (A) in the sealing process (b) and improving the reliability of the electronic device, it is preferably 400 μm or less, more preferably 350 μm or less, even more preferably 300 μm or less, even more preferably 250 μm or less, even more preferably 200 μm or less, and preferably 5 μm or more, more preferably 20 μm or more, even more preferably 30 μm or more, even more preferably 50 μm.

[0102] Furthermore, from the viewpoint of easily securing a gap between the main body portion 110 of the electronic component 70 and the adhesive resin layer (A) in the sealing process (b) and improving the reliability of the electronic device, when the height of the bump portion 120 is H, the thickness of the adhesive resin layer (A) is T, and the thickness of the unevenness-absorbing resin layer (C) is I, H / (T+I) is preferably greater than 1.1, more preferably 1.3 or more, even more preferably 1.5 or more, even more preferably 1.7 or more, even more preferably 1.9 or more, even more preferably 2.0 or more, and preferably less than 5.0, more preferably 4.5 or less, even more preferably 4.0 or less, even more preferably 3.7 or less, even more preferably 3.3 or less, and even more preferably 3.0 or less.

[0103] <Hard layer (D)> The adhesive film 50 according to this embodiment may further include a hard layer (D) within a range that does not impair the effect of this embodiment. The hard layer (D) can be provided, for example, between the base layer 10 and the adhesive resin layer (A) or between the base layer 10 and the irregularity-absorbing resin layer (C), and is preferably provided between the base layer 10 and the adhesive resin layer (A). The hard layer (D) is a layer that is provided for the purpose of preventing the electronic component 70 from sinking into the adhesive film 50, thereby making it easier to secure a gap between the main body 110 of the electronic component 70 and the adhesive resin layer (A) in the sealing process (b), thereby improving the reliability of the electronic device. The resin constituting the hard layer (D) is preferably one or more selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyimide, aramid, polyether ketone, polyether sulfone and polyphenylene sulfide, and more preferably one or more selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate, from the viewpoint of preventing the electronic component 70 from sinking into the adhesive film 50, thereby making it easier to secure a gap between the main body 110 of the electronic component 70 and the adhesive resin layer (A) in the sealing process (b) and improving the reliability of the electronic device. In addition, by preventing the electronic component 70 from sinking into the adhesive film 50, it is possible to prevent poor sealing of the electronic component 70A, known as standoff 90 (where part of the side of the electronic component 70A is not sealed), as well as wrinkles on the surface of the sealing material after sealing, as shown in Figure 5(d'). The Shore D hardness of the hard layer (D) according to Shore D hardness of ASTM D-2240 is preferably 53 or more, more preferably 55 or more, and even more preferably 60 or more, from the viewpoint of preventing the electronic component 70 from sinking into the adhesive film 50, thereby facilitating securing a gap between the main body 110 of the electronic component 70 and the adhesive resin layer (A) in the sealing step (b), and improving the reliability of the electronic device. The upper limit of the Shore D hardness is not particularly limited, but is, for example, 85 or less.

[0104] The hard layer (D) may be a single layer or two or more layers. The form of the resin film used to form the hard layer (D) may be a stretched film or a uniaxially or biaxially stretched film. From the viewpoint of improving the mechanical strength of the hard layer (D), however, a uniaxially or biaxially stretched film is preferable.

[0105] From the viewpoint of obtaining good film properties, the thickness of the hard layer (D) is preferably from 1 μm to 500 μm, more preferably from 5 μm to 300 μm, and further preferably from 10 μm to 250 μm. The hard layer (D) may be subjected to a surface treatment in order to improve adhesion to other layers, specifically, a corona treatment, a plasma treatment, an undercoat treatment, a primer coat treatment, or the like.

[0106] <Other layers> The adhesive film 50 according to this embodiment may further include, for example, an easy-adhesion layer or the like between each of the layers, as long as the effect of this embodiment is not impaired.

[0107] 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.

[0108] 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]

[0109] A Adhesive resin layer B Adhesive resin layer C. Unevenness-absorbing resin layer C' Unevenness-absorbing resin layer 10 Base material layer 10A 1st side 10B 2nd side 50 Adhesive Film 50A Adhesive Film 60 Encapsulating material 60A Sealing material 70 Electronic Components 70A Electronic Components 80 Support substrate 80A support board 90 Standoff 100 structures 110 Main body 120 Bump section 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 step (a) of preparing a structure including a support substrate attached to the adhesive resin layer (B) of the adhesive film; and (b) sealing the electronic component with a sealing material, the electronic component has a main body and a bump portion provided on at least one surface of the main body, the bump portion being in contact with the adhesive resin layer (A) of the adhesive film; In the step (b), the body portion of the electronic component is sealed with a gap provided between the body portion and the adhesive resin layer (A).

2. The method for manufacturing an electronic device according to claim 1 , wherein in the step (b), one surface of the electronic component that contacts the adhesive resin layer (A) is sealed.

3. 3. The method for manufacturing an electronic device according to claim 1, wherein in the step (b), all surfaces of the electronic component are encapsulated at once.

4. 3. The method for manufacturing an electronic device according to claim 1, wherein the electronic component has a rectangular parallelepiped shape, and in step (b), six faces of the rectangular parallelepiped shape are sealed together.

5. The method for manufacturing an electronic device according to claim 1 or 2, wherein the adhesive resin layer (A) has a thickness of 1 μm or more and 100 μm or less.

6. 3. The method for manufacturing an electronic device according to claim 1, wherein when a height of the bump portion of the electronic component is H and a thickness of the adhesive resin layer (A) is T, a relationship of 1.1<H / T<5.0 is satisfied.

7. The method for manufacturing an electronic device according to claim 1 or 2, wherein the adhesive film further comprises an unevenness-absorbing resin layer (C) at least one between the base layer and the adhesive resin layer (A) and between the base layer and the adhesive resin layer (B).

8. 8. The method for manufacturing an electronic device according to claim 7, further comprising, before the step (b), a step of crosslinking the unevenness-absorbing resin layer (C) in the structure by applying at least one type of energy selected from the group consisting of light energy and thermal energy to the unevenness-absorbing resin layer (C).

9. The method for manufacturing an electronic device according to claim 7, wherein the thickness of the irregularity-absorbing resin layer (C) is 5 μm or more and 400 μm or less.

10. 8. The method for manufacturing an electronic device according to claim 7, wherein when a height of the bump portion of the electronic component is H, a thickness of the adhesive resin layer (A) is T, and a thickness of the irregularity-absorbing resin layer (C) is I, a relationship of 1.1<H / (T+I)<5.0 is satisfied.

11. The method for producing an electronic device according to claim 1 or 2, wherein the adhesive film further comprises a hard layer (D), or the substrate layer is a hard layer.

12. A method for manufacturing an electronic device as described in Claim 11, wherein the hard layer (D) or the base layer comprises one or more materials selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyimide, aramid, polyether ketone, polyether sulfone and polyphenylene sulfide.

13. The method for manufacturing an electronic device according to claim 11, wherein the hard layer (D) or the base material layer has a Shore D hardness of 55 or more according to ASTM D-2240 Shore D hardness.

14. The method for manufacturing an electronic device according to claim 1 or 2, wherein the adhesive resin layer (B) is a layer whose adhesive strength decreases in response to an external stimulus.

15. 3. The method for manufacturing an electronic device according to claim 1 or 2, wherein the adhesive resin layer (A) contains one or more selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins.

16. The method for manufacturing an electronic device according to claim 1 , 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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