Electronic device production method

Abstract

This electronic device production method comprises: a step (a) for preparing a structure (100) including an adhesive film (50) that is provided with a base material layer (10), an adhesive resin layer (A) provided to a first surface (10A) side of the base material layer (10) and for provisionally fixing electronic components (70), and an adhesive resin layer (B) provided to a second surface (10B) side of the base material layer (10), said structure (100) further including electronic components (70) that are attached to the adhesive resin layer (A) of the adhesive film (50), and a support substrate (80) that is attached to the adhesive resin layer (B) of the adhesive film (50); and a step (b) for sealing the electronic components (70) with a sealing material (60). Each electronic component (70) has a main body (110) and a bump (120) that is provided to at least one surface of the main body (110). The bump (120) is in contact with the adhesive resin layer (A) of the adhesive film (50). At step (b), the main body (110) is sealed with a gap provided between the main body (110) of the electronic component (70) and the adhesive resin layer (A).

Description

Manufacturing method of electronic device

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

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

[0003] An example of a technique related to a method for manufacturing such a fan-out package is described in Patent Document 1. Patent Document 1 describes a heat-resistant adhesive sheet for semiconductor device manufacturing that is used by adhering when resin-encapsulating a substrateless semiconductor chip, as a method for solving the problem of the chip not being held in place due to pressure during resin encapsulation and shifting from its designated position, or the problem of the package being damaged when the heat-resistant adhesive sheet for semiconductor device manufacturing is peeled off due to the hardening of the encapsulant or heat causing the encapsulant to become strongly adhesive to the chip surface. The heat-resistant adhesive sheet has a base layer and an adhesive layer, and the adhesive layer has an adhesive strength to SUS304 stainless steel of 0.5 N / 20 mm or more after lamination and hardens due to stimuli received before the resin encapsulation process is completed, so that the peel strength to the package is 2.0 N / 20 mm or less.

[0004] JP 2011-134811 A

[0005] According to the research of the present inventors, 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, it has become clear that the surface of the electronic component that comes into contact with the adhesive film may not be sealed sufficiently, and the sealing material may not provide sufficient protection.

[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.

[0007] The present inventors have conducted extensive research to achieve the above object, and as a result have found 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, thereby improving the reliability of the electronic device, and have completed the present invention.

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

[0009] [1] A method for manufacturing an electronic device, the method comprising: a step (a) of preparing a structure including: a base layer; an adhesive film including 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; and a support substrate attached to the adhesive resin layer (B) of the adhesive film; and a step (b) of sealing the electronic component with a sealing material, wherein the electronic component has a main body portion and a bump portion provided on at least one surface of the main body portion, and the bump portion is in contact with the adhesive resin layer (A) of the adhesive film, and in the step (b), the method for manufacturing an electronic device comprises sealing the main body portion of the electronic component with a gap provided between the main body portion of the electronic component and the adhesive resin layer (A). [2] The method for manufacturing an electronic device according to [1] above, wherein in step (b), one surface of the electronic component that contacts the adhesive resin layer (A) is encapsulated. [3] The method for manufacturing an electronic device according to [1] or [2] above, wherein in step (b), all surfaces of the electronic component are encapsulated at once. [4] The method for manufacturing an electronic device according to any of [1] to [3] above, wherein the electronic component has a rectangular parallelepiped shape, and in step (b), six surfaces of the rectangular parallelepiped shape are encapsulated at once. [5] The method for manufacturing an electronic device according to any of [1] to [4] above, wherein the thickness of the adhesive resin layer (A) is 1 μm or more and 100 μm or less. [6] The method for manufacturing an electronic device according to any of [1] to [5] above, wherein, 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 relationship 1.1<H / T<5.0 is satisfied. [7] The method for producing an electronic device according to any one of [1] to [6], wherein the pressure-sensitive adhesive film further comprises an irregularity-absorbing resin layer (C) between the base material layer and the pressure-sensitive adhesive resin layer (A) or between the base material layer and the pressure-sensitive adhesive resin layer (B). [8] The method for producing an electronic device according to [7], further comprising, before the step (b), a step of crosslinking the irregularity-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 irregularity-absorbing resin layer (C).[9] The method for manufacturing an electronic device according to [7] or [8] above, wherein the thickness of the irregularity-absorbing resin layer (C) is 5 μm or more and 400 μm or less.

[10] The method for manufacturing an electronic device according to any of [7] to [9] above, wherein the relationship of 1.1 < H / (T + I) < 5.0 is satisfied, where H is the height of the bump portion of the electronic component, T is the thickness of the adhesive resin layer (A), and I is the thickness of the irregularity-absorbing resin layer (C).

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

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

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

[11] above, wherein the hard layer (D) or the base layer contains 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 method for manufacturing an electronic device according to any one of [1] to

[12] above, wherein the hard layer (D) or the base 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 any one of [1] to

[13] above, wherein the adhesive resin layer (B) is a layer whose adhesive strength decreases in response to an external stimulus.

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

[14] above, wherein the adhesive resin layer (A) contains one or more selected from the group consisting of a (meth)acrylic adhesive resin, a silicone adhesive resin, a urethane adhesive resin, an olefin adhesive resin, and a styrene adhesive resin.

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

[15] above, wherein the encapsulant contains an epoxy resin encapsulant.

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

[16] above, wherein the electronic device contains a fan-out type package.

[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.

[0011] Fig. 1 is a cross-sectional view schematically showing an example of the structure of an adhesive film according to an embodiment of the present invention. Fig. 2 is a cross-sectional view schematically showing an example of the structure of an adhesive film according to an embodiment of the present invention. Fig. 3 is a cross-sectional view schematically showing an example of a method for manufacturing an electronic device according to an embodiment of the present invention. Fig. 4 is a cross-sectional view schematically showing an example of a method for manufacturing an electronic device according to an embodiment of the present invention. Fig. 5 is a view for explaining a sealing defect of an electronic component called a standoff.

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

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

[0014] As described above, the inventors' studies revealed that when an electronic component having a concave-convex structure, such as bumps, is placed on an adhesive film and then sealed with an encapsulant, the surface of the electronic component in contact with the adhesive film may not be sufficiently sealed, resulting in insufficient protection by the encapsulant. The inventors conducted extensive research to achieve this goal. As a result, they discovered for the first time that sealing the electronic component with a gap between the main body portion of the electronic component and the adhesive film can adequately seal the surface of the electronic component in contact with the adhesive film, thereby improving the reliability of the electronic device. That is, according to the electronic device manufacturing method of this embodiment, by sealing the main body portion 110 of the electronic component 70 with a gap between the main body portion 110 and the adhesive resin layer (A), the surface of the electronic component 70 in contact with the adhesive resin layer (A) can be sealed, thereby improving the reliability of the electronic device. As described above, the electronic device manufacturing method of this embodiment makes it 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 step) In the preparation step, 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 produced, for example, by the following procedure. First, the adhesive film 50 is attached to the support substrate 80 so that the adhesive resin layer (B) faces the support substrate 80. A protective film may be attached to the adhesive resin layer (B), and the protective film can be peeled off, and the exposed surface of the adhesive resin layer (B) can be attached to the surface of the support substrate 80. As the support substrate 80, for example, a quartz substrate, a glass substrate, a SUS substrate, etc. can be used.

[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, as well as semiconductor panels and semiconductor packages. The electronic component 70 has a main body 110 having at least one surface, and a bump portion 120 is provided on at least one surface of the main body 110, thereby creating an uneven structure on the surface on which the bump portion 120 is provided. The shape of the electronic component 70 is not limited to a specific shape, but may be a rectangular parallelepiped. When the electronic component 70 has a rectangular parallelepiped shape, the bump portion 120 is provided on at least one of the six surfaces of the main body 110. Furthermore, the bump portion 120 is bonded to an electrode formed on a mounting surface when mounting an electronic device on the mounting surface, for example, to form an electrical connection between the electronic device and the mounting surface (such as a mounting surface of a printed circuit board). Examples of the bump portion 120 include bump electrodes such as ball bumps, printed bumps, stud bumps, plated bumps, and pillar bumps. These bump electrodes may be used alone or in combination of two or more types. The metal species constituting the bump electrode is not particularly limited, and examples include silver, gold, copper, tin, lead, bismuth, and alloys thereof. These metal species may be used alone or in combination of two or more types.

[0019] (b) Sealing Step) Next, the electronic component 70 is sealed with the sealing material 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 lower to seal the electronic component 70. Here, 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 that does not exceed 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, and may be, for example, granular, sheet-like, or liquid.

[0020] In the sealing step, 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). This seals the surface of the electronic component 70 that contacts the adhesive resin layer (A), thereby improving the reliability of the electronic device. From the viewpoint of further improving the reliability of the electronic device, in the sealing step (b), it is preferable to seal one surface of the electronic component 70 that contacts the adhesive resin layer (A), and it is more preferable to seal the entire surface of the electronic component 70 at once. 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, although 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, 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, even more preferably 3.0 or less.

[0022] The encapsulant 60 is not particularly limited, but preferably includes one or more types selected from an epoxy resin-based encapsulant using an epoxy resin and a silicone resin-based encapsulant using a silicone resin. Since this improves the affinity of the encapsulant 60 to the PSA film 50 and enables more uniform encapsulation of the electronic component 70, the encapsulant more preferably includes an epoxy resin-based encapsulant, and even more preferably includes a liquid epoxy resin-based encapsulant. Examples of such epoxy resin-based encapsulants include the T693 / R4000 series, T693 / R1000 series, and T693 / R5000 series manufactured by Nagase ChemteX Corporation. Examples of such silicone resin-based encapsulants include KMC-8400 manufactured by Shin-Etsu Chemical Co., Ltd., and TSE3033 and TSE3251 manufactured by Momentive Performance Materials Japan, Ltd.

[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, thereby obtaining the structure 100 in which the electronic component 70 is sealed.

[0024] 4(c) The method for manufacturing an electronic device according to this embodiment may further include, after the (b) sealing step, a first peeling step of applying an external stimulus to reduce the adhesive strength of the adhesive resin layer (B) and peeling the support substrate 80 from the structure 100. After sealing the electronic component 70, the support substrate 80 can be easily removed from the adhesive film 50 by, for example, 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) The method for manufacturing an electronic device according to this embodiment may further include, after the (c) First Peeling Step, a Second Peeling Step of peeling the adhesive film 50 from the electronic component 70 to obtain the electronic device 200, as shown in Fig. 4(d) . Examples of methods for peeling the adhesive film 50 from the electronic component 70 include a mechanical peeling method and a method of peeling after reducing the adhesive strength of the surface of the adhesive film 50.

[0026] (Other Processes) The method for manufacturing an electronic device according to this embodiment may further include a process (e) of forming a wiring layer 310 and a bump 320 on the exposed surface of the obtained electronic device 200, thereby obtaining 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, thereby obtaining the electronic device 300. Examples of the bumps 320 include solder bumps and gold bumps. Solder bumps can be formed, for example, by placing solder balls on pads that serve as external connection terminals of the wiring layer 310 and heating them to melt the solder (reflow). Gold bumps can be formed by methods such as ball bonding, plating, and Au ball transfer.

[0029] 4( f), 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. The dicing of the electronic device 300 can be performed by a known method.

[0030] The type of electronic device 300 is not particularly limited, but preferably includes a fan-out type package. A fan-out type package allows terminals to 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 now be described. Figures 1 and 2 are cross-sectional views that schematically 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 according to 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, more preferably 20 μm or more and 500 μm or less, from the viewpoint of the balance between mechanical properties and handling properties.

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

[0035] <Substrate Layer> The substrate layer 10 is a layer provided for the purpose of improving the handleability, mechanical properties, heat resistance, and other properties of the pressure-sensitive adhesive film 50. The substrate layer 10 is not particularly limited, but examples thereof include a resin film. A known thermoplastic resin can be used as the resin constituting the resin film. Examples include one or more resins 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 polymethaxylene adipamide; polyacrylate; polymethacrylate; polyvinyl chloride; polyvinylidene chloride; polyimide; polyetherimide; ethylene-vinyl acetate copolymer; polyacrylonitrile; polycarbonate; polystyrene; ionomer; polysulfone; polyethersulfone; and polyphenylene ether. Among these, from the viewpoint of preventing the electronic component 70 from sinking into the adhesive film 50, thereby facilitating the creation of 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, one or more 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 selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate are more preferred. Furthermore, preventing the electronic component 70 from sinking into the adhesive film 50 also has the effect of preventing poor sealing of the electronic component 70A, known as standoff 90 (where a portion of the side surface of the electronic component 70A is not sealed), as shown in FIG. 5(d'), and preventing wrinkles from occurring on the surface of the sealing material 60 after sealing.Furthermore, the Shore D hardness of the base material 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 suppressing sinking of the electronic component 70 into the adhesive film 50, thereby making it easier to ensure 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 base layer 10 may be a single layer or two or more layers. The resin film used to form the base layer 10 may be a stretched film or a uniaxially or biaxially stretched film, but from the viewpoint of improving the mechanical strength of the base layer 10, a uniaxially or biaxially stretched film is preferred.

[0037] From the viewpoint of obtaining good film properties, the thickness of the substrate 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 even more preferably 10 μm or more and 250 μm or less. The substrate layer 10 may be subjected to a surface treatment to improve adhesion to other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coating treatment, etc. may be performed.

[0038] <Adhesive Resin Layer (A)> The adhesive resin layer (A) is a layer provided on one surface of the base layer 10. The adhesive resin layer (A) is a layer that comes into contact with the surface of the electronic component 70 to temporarily fix the electronic component 70 when the electronic component 70 is sealed with the sealing material 60 in the manufacturing process of the 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, (meth)acrylic adhesive resins (a) are preferred from the viewpoint of facilitating adjustment of adhesive strength.

[0040] The adhesive resin layer (A) may be a radiation-crosslinkable adhesive resin layer whose adhesive strength can be reduced by radiation. When the radiation-crosslinkable adhesive resin layer is irradiated with radiation, crosslinking occurs, significantly reducing the adhesive strength, making it easier to peel the adhesive film 50 from the electronic component 70. Examples of radiation include ultraviolet light, electron beams, and infrared light. As the radiation-crosslinkable adhesive resin layer, an ultraviolet-crosslinkable adhesive resin layer is preferred.

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

[0044] Examples of the monomer (a2) that forms the monomer unit (a2) having a functional group reactive with a crosslinking agent include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, itaconic acid monoalkyl ester, mesaconic acid monoalkyl ester, citraconic acid monoalkyl ester, fumaric acid monoalkyl ester, maleic acid monoalkyl ester, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tert-butylaminoethyl acrylate, and tert-butylaminoethyl methacrylate. Preferred are acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, and the like. These may be used alone or in combination of two or more. In the (meth)acrylic adhesive resin (a) according to the present embodiment, the content of the monomer unit (a2) is preferably 1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 20% by mass or less, and even more preferably 1% by mass or more and 10% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is 100% by mass.

[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 when emulsion polymerization is performed.

[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 propylene glycol main chain structure (e.g., manufactured by NOF Corporation, trade names: PDP-200, PDP-400, ADP-200, ADP-400), tetramethylene glycol (e.g., manufactured by NOF Corporation, trade names: ADT-250, ADT-850), and mixtures thereof (e.g., manufactured by NOF Corporation, trade names: ADET-1800, ADPT-4000).

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

[0048] Examples of the polymerizable surfactant 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 the present embodiment, the content of the polymerizable surfactant is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 20% by mass or less, even more preferably 0.1% by mass or more and 15% by mass or less, and still more preferably 0.1% by mass or more and 5% by mass or less, when the sum of all monomer units in the (meth)acrylic adhesive resin (a) is 100% by mass.

[0049] The (meth)acrylic adhesive resin (a) according to the present embodiment may further contain, if necessary, a monomer unit formed from a monomer having a polymerizable double bond, such as vinyl acetate, acrylonitrile, or styrene.

[0050] The polymerization reaction mechanism of the (meth)acrylic adhesive resin (a) according to this embodiment may be radical polymerization, anionic polymerization, cationic polymerization, or the like. Taking into consideration the production cost of the (meth)acrylic adhesive resin (a), the influence of the functional groups of the monomer, and the influence of ions on the surface of the electronic component 70, polymerization by radical polymerization is preferred. When polymerization is carried out by radical polymerization, the radical polymerization initiator may be selected from the group consisting of benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, 3,3,5-trimethylhexanoyl peroxide, di-2-ethylhexyl peroxydicarbonate, methyl ethyl ketone peroxide, t-butyl peroxyphthalate, t-butyl peroxybenzoate, di-t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butylperoxy-2-hexanoate, t-butyl peroxy, and the like. Examples of the peroxide 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, inorganic peroxides such as water-soluble ammonium persulfate, potassium persulfate, and sodium persulfate, and azo compounds having a carboxyl group in the molecule such as water-soluble 4,4'-azobis-4-cyanovaleric acid are preferred. Considering the influence of ions on the surface of electronic component 70, 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 per molecule. The crosslinking agent (A2) having two or more crosslinkable functional groups per molecule can be reacted with the functional groups of the adhesive resin (A1) to adjust the adhesive strength and cohesive strength. Examples of such crosslinking agents (A2) include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcinol 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. Examples of suitable aziridine compounds include 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 compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine compounds such as hexamethoxymethylolmelamine. These compounds may be used alone or in combination. 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 such that 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, an excess amount of the crosslinking agent (A2) may be added as necessary when new functional groups are generated in the crosslinking reaction or when the crosslinking reaction is slow. From the viewpoint of improving the balance between the heat resistance and adhesion of the adhesive resin layer (A), 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).

[0054] The adhesive resin layer (A) may contain additives such as plasticizers and tackifying resins as other components. When the adhesive resin layer (A) is a radiation-crosslinkable adhesive resin layer, it may contain various additives for radiation crosslinking. The total content of the adhesive resin (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 reduce adhesive residue on the electronic component 70 when the adhesive film 50 is peeled from the electronic component 70.

[0055] The adhesive resin layer (A) may be a single layer or a multilayer. The thickness of the adhesive resin layer (A) is not particularly limited, but from the viewpoint of easily ensuring 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 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, still 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 to the substrate layer 10. The adhesive may be dissolved in a solvent and applied as a coating liquid, or may be applied as an aqueous emulsion, or the liquid adhesive may be applied directly. Among these, aqueous emulsion coating liquids are preferred. Examples of aqueous emulsion coating liquids include coating liquids prepared by dispersing (meth)acrylic adhesive resin (a), silicone adhesive resin, urethane adhesive resin, olefin adhesive resin, styrene adhesive resin, or the like in water. An adhesive coating liquid dissolved in an organic solvent may also be used. The organic solvent is not particularly limited and may be appropriately selected from known solvents taking into account solubility and drying time. Examples of organic solvents include esters such as ethyl acetate and methyl acetate; ketones such as acetone and MEK; aromatic solvents such as benzene, toluene, and ethylbenzene; linear or cyclic aliphatic solvents such as heptane, hexane, and cyclohexane; and alcohols such as isopropanol and butanol. Ethyl acetate and toluene are preferred organic solvents. These solvents may be used alone or in combination of two or more.

[0057] The adhesive coating liquid can be applied using conventional coating methods such as a roll coater method, a reverse roll coater method, a gravure roll method, a bar coater method, a comma coater method, or a die coater method. The drying conditions for the applied adhesive are not particularly limited, but generally, drying is preferably performed for 10 seconds to 10 minutes at a temperature range of 80 to 200°C. Drying for 15 seconds to 5 minutes at 80 to 170°C is even more preferable. To sufficiently promote the crosslinking reaction between the crosslinker and the adhesive, the adhesive coating liquid may be heated at 40 to 80°C for approximately 5 to 300 hours after drying is complete.

[0058] The base material layer 10 and the adhesive resin layer (A) may be formed by co-extrusion molding, or may be formed by laminating a film-like base material layer 10 and a film-like adhesive resin layer (A).

[0059] <Adhesive Resin Layer (B)> The adhesive film 50 according to this embodiment includes an adhesive resin layer (B) on the second surface 10B of the base layer 10, opposite the first surface 10A. The adhesive resin layer (B) is preferably a layer whose adhesive strength decreases with an external stimulus. This allows the adhesive film 50 to be easily peeled off from the support substrate 80 by applying an external stimulus. Examples of the adhesive resin layer (B) whose adhesive strength decreases with an external stimulus include a heat-peelable adhesive resin layer whose adhesive strength decreases with heat, and a light-peelable adhesive resin layer whose adhesive strength decreases with light such as radiation. That is, examples of the external stimulus include light energy and thermal energy. Examples of the heat-peelable adhesive resin layer include an adhesive resin (B1) and an adhesive resin layer composed of a heat-expandable adhesive that further contains a gas-generating component, a heat-expandable adhesive containing heat-expandable microspheres that expand to reduce adhesive strength, and a heat-expandable adhesive whose adhesive strength decreases due to a crosslinking reaction of the adhesive component with heat.

[0060] In this embodiment, the thermally expandable adhesive used in the adhesive resin layer (B) is an adhesive whose adhesive strength decreases or is lost when heated, for example, above 150°C, preferably above 170°C. For example, a material can be selected that does not peel at temperatures below 150°C or below 170°C, but peels above 150°C or above 170°C. Preferably, the adhesive strength is sufficient to prevent the adhesive film 50 from peeling from the support substrate 80 during the manufacturing process of the electronic device. Here, the decrease or loss of adhesive strength due to heating above 150°C or above 170°C can be evaluated, for example, by attaching the adhesive resin layer (B) side to a stainless steel plate, subjecting it to heat treatment at 140°C for 1 hour, and then heating it at a temperature above 150°C or above 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 above 150°C or above 170°C is set to a temperature higher than the temperature at which gas is generated or the temperature at which the heat-expandable microspheres thermally expand, and is set appropriately depending on the gas generated and the type of heat-expandable microspheres. In this embodiment, loss of adhesive strength refers to, for example, a case where the 180° peel strength measured under conditions of 23° C. and a pulling rate of 300 mm / min becomes less than 0.5 N / 25 mm.

[0061] Examples of gas-generating components that can be used in thermally expandable pressure-sensitive adhesives include azo compounds, azide compounds, and Meldrum's acid derivatives. Other examples include inorganic blowing agents such as ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium boron hydroxide, and various azides; water; fluorinated alkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate; paratoluenesulfonylhydrazide, diphenylsulfone-3,3'-disulfonylhydrazide, 4,4'-oxybis(benzenesulfonyl)hydrazide; Other examples of organic blowing agents that can be used include hydrazine compounds such as p-toluenesulfonylsemicarbazide and 4,4'-oxybis(benzenesulfonylsemicarbazide); semicarbazide 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] The heat-expandable microspheres used in heat-expandable pressure-sensitive adhesives can be, for example, microencapsulated blowing agents. Examples of such heat-expandable microspheres include microspheres in which a substance that easily gasifies and expands upon heating, such as isobutane, propane, or pentane, is encapsulated within 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 coacervation or interfacial polymerization. Heat-expandable microspheres can be added to adhesive resins.

[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 to 150 parts by mass, preferably 10 to 130 parts by mass, and more preferably 12 to 100 parts by mass, per 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 thermally expand are above 150°C or above 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 refers to 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 containing about 1 to 12 carbon atoms. (Meth)acrylic acid alkyl esters having an alkyl group containing 1 to 8 carbon atoms are preferred. 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 10% by mass or more and 98.9% by mass or less, more preferably 50% by mass or more and 97% by mass or less, and even more preferably 85% by mass or more and 95% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is taken as 100% by mass.

[0068] Examples of the monomer (b2) that forms the monomer (b2) having a functional group reactive with a crosslinking agent include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, itaconic acid monoalkyl ester, mesaconic acid monoalkyl ester, citraconic acid monoalkyl ester, fumaric acid monoalkyl ester, maleic acid monoalkyl ester, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tert-butylaminoethyl acrylate, and tert-butylaminoethyl methacrylate. Preferred are acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, and the like. These may be used alone or in combination of two or more. In the (meth)acrylic adhesive resin (b) according to the present embodiment, the content of the monomer unit (b2) is preferably 1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 20% by mass or less, and even more preferably 1% by mass or more and 10% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is 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 when emulsion polymerization is performed.

[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 propylene glycol main chain structure (e.g., manufactured by NOF Corporation; trade names: PDP-200, PDP-400, ADP-200, ADP-400), tetramethylene glycol (e.g., manufactured by NOF Corporation; trade names: ADT-250, ADT-850), and mixtures thereof (e.g., manufactured by NOF Corporation; trade names: ADET-1800, ADPT-4000).

[0071] In the (meth)acrylic adhesive resin (b) according to the present embodiment, the content of the bifunctional monomer unit (b3) is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 20% by mass or less, even more preferably 0.1% by mass or more and 15% by mass or less, and still more preferably 0.1% by mass or more and 5% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is 100% by mass.

[0072] Examples of the polymerizable surfactant 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 the present embodiment, the content of the polymerizable surfactant is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 20% by mass or less, even more preferably 0.1% by mass or more and 15% by mass or less, and still more preferably 0.1% by mass or more and 5% by mass or less, when the sum of all monomer units in the (meth)acrylic adhesive resin (b) is 100% by mass.

[0073] The (meth)acrylic adhesive resin (b) according to the present embodiment may further contain, as 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 this embodiment may be radical polymerization, anionic polymerization, cationic polymerization, or the like. Taking into consideration the production cost of the (meth)acrylic adhesive resin (b), the influence of the functional groups of the monomer, and the influence of ions on the surface of the electronic component 70, polymerization by radical polymerization is preferred. When polymerization is carried out by radical polymerization, the radical polymerization initiator may be selected from the group consisting of benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, 3,3,5-trimethylhexanoyl peroxide, di-2-ethylhexyl peroxydicarbonate, methyl ethyl ketone peroxide, t-butyl peroxyphthalate, t-butyl peroxybenzoate, di-t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butylperoxy-2-hexanoate, t-butyl peroxy, and the like. Examples of the peroxide 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, inorganic peroxides such as water-soluble ammonium persulfate, potassium persulfate, and sodium persulfate, and azo compounds having a carboxyl group in the molecule such as water-soluble 4,4'-azobis-4-cyanovaleric acid are preferred. Considering the influence of ions on the surface of electronic component 70, 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 per molecule. The crosslinking agent (B2) having two or more crosslinkable functional groups per molecule is reacted 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 resorcinol 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. Examples of suitable aziridine compounds include 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 compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine compounds such as hexamethoxymethylolmelamine. These compounds may be used alone or in combination. 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 such that 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 amount of the crosslinking agent (B2) may be added when new functional groups are generated in 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 parts by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 5 parts by mass or less, per 100 parts by mass of the adhesive resin (B1).

[0078] From the viewpoint of improving adhesion to the support substrate 80, the adhesive resin layer (B) according to this embodiment preferably contains a tackifier resin in addition to the adhesive resin (B1). Inclusion of a tackifier resin in the adhesive resin layer (B) is preferred because it facilitates adjustment of adhesion to the support substrate 80 at around room temperature. The tackifier resin preferably has a softening point of 100°C or higher. Specific examples of tackifier resins include rosin-based resins such as rosin derivatives that have been treated with esterification or the like; terpene-based resins such as α-pinene, β-pinene, dipentene, 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, maleation, or 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 in the range of 120 to 150°C are even more preferred. Using a tackifier resin having a softening point within the above range not only reduces contamination and adhesive residue on the support substrate 80, but also enables further improved adhesion to the support substrate 80 in the working environment. Furthermore, using a polymerized rosin ester-based tackifier resin as the tackifier resin not only reduces contamination and adhesive residue on the support substrate 80, but also improves adhesion to the support substrate 80 in an environment of 80 to 130°C, and in the case of a heat-expandable pressure-sensitive adhesive containing heat-expandable microspheres, it enables even easier peeling from the support substrate 80 after the heat-expandable microspheres have expanded.

[0080] The blending ratio of the tackifier resin is not particularly limited, and may be appropriately selected so as to adjust the elastic modulus of the adhesive resin layer (B) within the desired predetermined numerical range. However, in terms of the elastic modulus and initial peel strength of the adhesive resin layer (B), a blending ratio of 1 to 100 parts by mass per 100 parts by mass of the adhesive resin (B1) is preferred. When the blending ratio of the tackifier resin is equal to or greater than the lower limit per 100 parts by mass of the adhesive resin (B1), adhesion to the support substrate 80 during operation tends to be improved. On the other hand, when the blending ratio is equal to or less than the upper limit, attachment to the support substrate 80 at room temperature tends to be improved. In terms of adhesion to the support substrate 80 and attachment at room temperature, a blending ratio of the tackifier resin of 2 to 50 parts by mass per 100 parts by mass of the adhesive resin (B1) is more preferred. Furthermore, 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 upper limit, adhesive residue on the support substrate 80 tends to be less likely to be left 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 with different degrees of expansion upon 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, 3 μm or more and 300 μm or less, and more preferably 20 μm or more and 150 μm or less.

[0083] The adhesive resin layer (B) can be formed, for example, by 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. Conventional coating methods, such as roll coating, reverse roll coating, gravure roll coating, bar coating, comma coating, and die coating, can be used to apply the adhesive coating liquid. While there are no particular limitations on the drying conditions for the applied adhesive, drying at a temperature range of 80 to 200°C for 10 seconds to 10 minutes is generally preferred. Drying at 80 to 170°C for 15 seconds to 5 minutes is more preferred. To sufficiently promote the crosslinking reaction between the crosslinker and the adhesive, the adhesive coating liquid may be heated at 40 to 80°C for approximately 5 to 300 hours after drying. The base material layer 10 and the adhesive resin layer (B) may be formed by co-extrusion molding, or may be formed by laminating a film-like base material layer 10 and a film-like adhesive resin layer (B).

[0084] <Irregularity-Absorbing Resin Layer (C)> As shown in Figure 2, the pressure-sensitive adhesive film 50 according to this embodiment preferably further comprises an irregularity-absorbing resin layer (C) between the substrate layer 10 and the adhesive resin layer (A) or between the substrate layer 10 and the adhesive resin layer (B), and more preferably comprises an irregularity-absorbing resin layer (C) between the substrate layer 10 and the adhesive resin layer (A). The irregularity-absorbing resin layer (C) is a layer provided for the purpose of improving the conformability of the pressure-sensitive adhesive film 50 to the surface of the electronic component 70 on which the irregular structure is formed, and improving the adhesion between the electronic component 70 having the irregular structure and the adhesive film 50. Furthermore, the irregularity-absorbing resin layer (C) is preferably crosslinkable by at least one type of energy selected from the group consisting of light energy and thermal energy. By crosslinking and curing the irregularity-absorbing resin layer (C), the elastic modulus of the irregularity-absorbing resin layer (C) can be increased. That is, the method for manufacturing an electronic device according to this embodiment preferably further includes a step of crosslinking the irregularity-absorbing resin layer (C) in the structure 100 by applying at least one type of energy selected from the group consisting of light energy and thermal energy to the irregularity-absorbing resin layer (C) prior to the sealing step (b). This can prevent the electronic component 70 from sinking into the adhesive film 50 in the sealing step (b), making it easier to ensure a gap between the main body 110 of the electronic component 70 and the adhesive resin layer (A) in the sealing step (b). Furthermore, suppressing the sinking of the electronic component 70 into the adhesive film 50 also has the effect of preventing poor sealing of the electronic component 70A, known as standoff 90 (where a portion of the side surface of the electronic component 70A is not sealed), as shown in FIG. 5(d'), and wrinkles that occur on the surface of the sealant 60 after sealing.

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

[0086] The irregularity-absorbing resin layer (C) preferably contains a resin, a crosslinking agent, and at least one initiator selected from a photoinitiator and a thermal initiator. Here, the photoinitiator is a compound that generates activated chemical species when exposed to light, and the thermal initiator is a compound that generates activated chemical species when exposed to heat. By including these components in the irregularity-absorbing resin layer (C), the irregularity-absorbing resin layer (C) can be more effectively crosslinked by at least one of light energy and thermal energy, further improving the elastic modulus of the irregularity-absorbing resin layer (C). This prevents the irregularity-absorbing resin layer (C) from softening due to heat during the process of sealing the electronic component 70 with the sealing material 60, thereby further preventing 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 irregularity-absorbing resin layer (C) may be crosslinked (cured) by at least one of light energy and thermal energy even without necessarily containing an initiator.

[0087] The resin constituting the irregularity-absorbing resin layer (C) is not particularly limited, but preferred examples include the resins described above as the adhesive resin (B1) in the adhesive resin layer (B). The resin constituting the irregularity-absorbing resin layer (C) is not particularly limited, and examples thereof include olefin-based 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; and ethylene-epoxy-containing unsaturated compound copolymers and ethylene-α-olefin-epoxy-containing unsaturated compound copolymers. Epoxy copolymers; ethylene-(meth)acrylic acid ester copolymers such as ethylene-ethyl (meth)acrylate copolymer, ethylene-methyl (meth)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 copolymers and ethylene-metal methacrylate copolymers; urethane-based resins; silicone-based resins; acrylic acid-based resins; methacrylic acid-based resins; cyclic olefin (co)polymers; α-olefin-aromatic vinyl compound-aromatic polyene copolymers; ethylene-α-olefin-aromatic vinyl compound; aromatic polyene copolymers; ethylene-aromatic vinyl compound-aromatic polyene copolymers; styrene-based resins; acrylonitrile-butadiene-styrene copolymers; styrene-conjugated diene copolymers; acrylonitrile-styrene copolymers; acrylonitrile-ethylene-α-olefin-non-conjugated polyene One or more materials selected from the group consisting of styrene copolymers, acrylonitrile-ethylene-α-olefin-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 crystalline polyesters, polylactic acid, etc. can be used. The unevenness-absorbing resin layer (C) may contain only one resin, or may contain two or more resins.

[0088] The crosslinking agent contained in the roughness-absorbing resin layer (C) can be any crosslinking agent that undergoes a crosslinking reaction with a chemical species generated from an initiator, without any particular limitation. Examples of the crosslinking agent include polyfunctional (meth)acrylate compounds and isocyanate compounds, and more specifically, 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, etc.; 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, polybutadiene compounds, etc. The amount of the crosslinking agent is, for example, 5 parts by mass or more and 500 parts by mass or less, preferably 40 parts by mass or more and 150 parts by mass or less, relative to 100 parts by mass of the resin (base polymer) such as the (meth)acrylic polymer in the roughness-absorbing resin layer (C).

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

[0090] The photoinitiator contained in the roughness-absorbing resin layer (C) is not particularly limited as long as it can crosslink 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 possessed by the resin and / or crosslinking agent. The chemical species generated from the photoinitiator is typically a radical or cation.

[0091] Examples of photoinitiators that can be used include alkylphenone-based photoinitiators, acetophenone-based photoinitiators, oxime ester-based photoinitiators, benzoin ether-based photoinitiators, acylphosphine oxide-based photoinitiators, α-ketol-based photoinitiators, aromatic sulfonyl chloride-based photoinitiators, photoactive oxime-based photoinitiators, benzoin-based photoinitiators, benzyl-based photoinitiators, benzophenone-based photoinitiators, and thioxanthone-based photoinitiators. These photoinitiators can be used alone or in appropriate combinations of two or more. Among these, it is preferable to use an alkylphenone-based photoinitiator from the viewpoints 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, etc. Specific examples of oxime ester-based 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), etc. 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, as well as 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, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. Specific examples of α-ketol photoinitiators include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one.Specific examples of aromatic sulfonyl chloride photoinitiators include 2-naphthalenesulfonyl chloride. Specific examples of photoactive oxime photoinitiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Specific examples of benzoin photoinitiators include benzoin. Specific examples of benzyl photoinitiators include benzyl. Specific examples of benzophenone photoinitiators include benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, etc. Specific examples of the thioxanthone-based photoinitiator 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) and generates radicals can be preferably used. The photoinitiators can be used alone or in appropriate combination of two or more.

[0094] The content of the photoinitiator in the roughness-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, relative to 100 parts by mass of the resin (base polymer) such as a (meth)acrylic polymer in the roughness-absorbing resin layer (C). From the viewpoint of storage stability, the content is preferably 7 parts by mass or less, more preferably 3 parts by mass or less.

[0095] The thermal initiator contained in the roughness-absorbing resin layer (C) is not particularly limited as long as it can crosslink the resin and / or crosslinking agent in the roughness-absorbing resin layer (C) by thermal energy. The chemical species generated from the thermal initiator may be appropriately selected based on the functional groups possessed by the resin and / or crosslinking agent. The chemical species generated from the thermal initiator is typically a radical or 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 with carbon-halogen bonds, and azo compounds.These may be used alone or in combination of two or more.Among these, azo compounds or organic peroxides are preferred in terms 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, Perloyl TCP, Perloyl L, Perloyl 355, Perloyl 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, Kayacumen H, Kayabutyl H-70, Perkadox BC-FF, and Kayahexyl. 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, Kayacarbon EH, Kayacarbon I-20, Kayacarbon BIC-75, Trigonox 117, Kayalene 6-70 (all manufactured by Kayaku Akzo Co., Ltd.)

[0098] The content of the thermal initiator in the roughness-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, relative to 100 parts by mass of the resin (base polymer) such as a (meth)acrylic polymer in the roughness-absorbing resin layer (C). From the viewpoint of storage stability, it is preferably 7 parts by mass or less, more preferably 3 parts by mass or less.

[0099] In the pressure-sensitive adhesive film 50 according to this 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, from the viewpoint of being able 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. ３ Pa or more is preferable, and 5.0 × 10 ３ In the pressure-sensitive adhesive film 50 according to the present embodiment, the upper limit of the storage modulus E' at 60°C of the irregularity-absorbing resin layer (C) before crosslinking is 1.0 x 10 Pa or more, from the viewpoint of effectively absorbing the irregularities on the surface of the electronic component 70 and preventing deterioration of the irregularity absorption over time due to springback of the resin. ６ Pa or less, and 5.0 × 10 ５ 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 the components constituting the unevenness-absorbing resin layer (C).

[0100] In the pressure-sensitive adhesive film 50 according to this embodiment, the lower limit of the storage modulus E' at 125°C of the irregularity-absorbing resin layer (C') obtained by crosslinking the irregularity-absorbing resin layer (C) is 1.0 × 10, from the viewpoint of being able 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, and 5.0 × 10 ６ 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 preferably 1.0×10 Pa or more, since this can further suppress displacement of the electronic component 70 in the sealing step (b). ９ Pa or less, and 1.0 × 10８ Pa or less is more preferable. The storage modulus E' of the unevenness-absorbent 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-absorbent resin layer (C). Here, whether or not the crosslinking treatment of the unevenness-absorbent resin layer (C) is complete can be determined, for example, by determining the point at which the storage modulus E' of the unevenness-absorbent 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 step (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 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 step (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 pressure-sensitive adhesive film 50 according to this embodiment may further include a hard layer (D) within a range that does not impair the effects of this embodiment. The hard layer (D) can be provided, for example, between the base material layer 10 and the adhesive resin layer (A) or between the base material layer 10 and the irregularity-absorbing resin layer (C), and is preferably provided between the base material layer 10 and the adhesive resin layer (A). The hard layer (D) is a layer provided for the purpose of suppressing sinking of the electronic component 70 into the pressure-sensitive adhesive film 50, thereby making it easier to ensure 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 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 facilitating the creation of 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. Furthermore, by preventing the electronic component 70 from sinking into the adhesive film 50, the effect of preventing the occurrence of a seal defect of the electronic component 70A, known as a standoff 90 (where a portion of the side surface of the electronic component 70A is not sealed), and the occurrence of wrinkles on the surface of the sealant 60 after sealing is also achieved. Furthermore, the Shore D hardness of the hard layer (D) 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 suppressing sinking of the electronic component 70 into the adhesive film 50, thereby making it easier to ensure 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, but from the viewpoint of improving the mechanical strength of the hard layer (D), a uniaxially or biaxially stretched film is preferred.

[0105] From the viewpoint of obtaining good film properties, the thickness of the hard layer (D) is preferably 1 μm or more and 500 μm or less, more preferably 5 μm or more and 300 μm or less, and even more preferably 10 μm or more and 250 μm or less. The hard layer (D) may be subjected to a surface treatment to improve adhesion to other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coating treatment, etc. may be performed.

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

[0107] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted.

[0108] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0109] A Adhesive resin layer B Adhesive resin layer C Irregularity-absorbing resin layer C' Irregularity-absorbing resin layer 10 Base layer 10A First surface 10B Second surface 50 Adhesive film 50A Adhesive film 60 Sealing material 60A Sealing material 70 Electronic component 70A Electronic component 75A Bump portion 80 Support substrate 80A Support substrate 90 Standoff 100 Structure 110 Main body portion 120 Bump portion 200 Electronic device 300 Electronic device 310 Wiring layer 320 Bump 400 Electronic device

Claims

1. A method for manufacturing an electronic device, comprising: a step (a) of preparing a structure comprising: an adhesive film comprising a base layer, an adhesive resin layer (A) provided on a first surface of the base layer for temporarily fixing an electronic component, and an adhesive resin layer (B) provided on a second surface of the base layer; an electronic component attached to the adhesive resin layer (A) of the adhesive film; and a support substrate attached to the adhesive resin layer (B) of the adhesive film; and a step (b) of encapsulating the electronic component with an encapsulant, wherein the electronic component has a main body portion and a bump portion provided on at least one surface of the main body portion, the bump portion being in contact with the adhesive resin layer (A) of the adhesive film, and in the step (b), the main body portion of the electronic component is encapsulated with a gap between the main body portion of the electronic component and the adhesive resin layer (A).

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

3. The method for manufacturing an electronic device according to claim 1 or 2, wherein in step (b), the entire surfaces of the electronic components are encapsulated all at once.

4. The method for manufacturing an electronic device according to any one of claims 1 to 3, 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 any one of claims 1 to 4, wherein the thickness of the adhesive resin layer (A) is 1 μm or more and 100 μm or less.

6. A method for manufacturing an electronic device according to any one of claims 1 to 5, wherein the relationship 1.1<H / T<5.0 is satisfied, where H is the height of the bump portion of the electronic component and T is the thickness of the adhesive resin layer (A).

7. A method for manufacturing an electronic device according to any one of claims 1 to 6, wherein the adhesive film further comprises an irregularity-absorbing resin layer (C) at least either between the base layer and the adhesive resin layer (A) or between the base layer and the adhesive resin layer (B).

8. A method for manufacturing an electronic device as described in claim 7, further comprising, before 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 or 8, wherein the thickness of the irregularity-absorbing resin layer (C) is 5 μm or more and 400 μm or less.

10. A method for manufacturing an electronic device according to any one of claims 7 to 9, wherein the relationship 1.1 < H / (T + I) < 5.0 is satisfied, where H is the height of the bump portion of the electronic component, T is the thickness of the adhesive resin layer (A), and I is the thickness of the irregularity-absorbing resin layer (C).

11. The method for manufacturing an electronic device according to any one of claims 1 to 10, wherein the adhesive film further comprises a hard layer (D), or the substrate layer is a hard layer.

12. The method for manufacturing an electronic device according to any one of claims 1 to 11, wherein the hard layer (D) or the substrate layer contains 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 any one of claims 1 to 12, wherein the hard layer (D) or the substrate layer has a Shore D hardness of 55 or more according to Shore D hardness of ASTM D-2240.

14. The method for manufacturing an electronic device according to any one of claims 1 to 13, wherein the adhesive resin layer (B) is a layer whose adhesive strength decreases in response to an external stimulus.

15. A method for manufacturing an electronic device according to any one of claims 1 to 14, wherein the adhesive resin layer (A) contains one or more types 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 any one of claims 1 to 15, wherein the sealing material includes an epoxy resin-based sealing material.

17. The method for manufacturing an electronic device according to any one of claims 1 to 16, wherein the electronic device comprises a fan-out type package.

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