Method for manufacturing electronic device

Abstract

The method for manufacturing an electronic device of the present invention comprises at least the following steps: step (1), preparing a structure (100), wherein the structure (100) comprises an adhesive film (50), an electronic component (70) and a supporting substrate (80), wherein the adhesive film (50) comprises: a base material layer (10), an adhesive resin layer (A) disposed on the first surface (10A) side of the base material layer (10) and used for temporarily fixing the electronic component (70), and an adhesive resin layer (A) disposed on the second surface (10B) side of the base material layer (10) and having an adhesive force due to external The adhesive resin layer (B) is reduced by stimulation, the electronic component (70) is adhered to the adhesive resin layer (A) of the adhesive film (50), and the supporting substrate (80) is adhered to the adhesive resin layer (B) of the adhesive film (50); step (2), at least one of the steps (2-1) of reducing the moisture content in the adhesive film (50) and the step (2-2) of reducing the moisture content in the structure (100), and step (3), sealing the electronic component (70) by a sealing material (60).

Description

Technical Field

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

[0002] As a technology capable of achieving miniaturization and weight reduction of electronic devices (for example, semiconductor devices), fan-out type WLP (wafer level packaging) is being developed.

[0003] In eWLB (Embedded Wafer Level Ball Grid Array), which is one of the methods for manufacturing fan-out WLP, the following method is adopted: multiple electronic components such as semiconductor chips are temporarily fixed in a separated state on an adhesive film attached to a supporting substrate, and the multiple electronic components are sealed together with a sealing material. Here, the adhesive film needs to be adhered to the electronic component and the supporting substrate during the sealing process, etc., and it needs to be removed from the sealed electronic component together with the supporting substrate after sealing.

[0004] As a related art of a method for manufacturing such a fan-out WLP, for example, there is the art described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2011-134811).

[0005] Patent document 1 describes a heat-resistant adhesive sheet for manufacturing semiconductor devices, which is characterized in that it is a heat-resistant adhesive sheet for manufacturing semiconductor devices that is used for attaching when a substrate-less semiconductor chip is resin-sealed. The heat-resistant adhesive sheet has a base material layer and an adhesive layer. The adhesive layer has an adhesion to SUS304 of more than 0.5N / 20mm after bonding, and is cured due to the stimulation received until the end of the resin sealing process, so that the peeling force to the package becomes less than 2.0N / 20mm.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2011-134811 Summary of the invention

[0009] Problems to be solved by the invention

[0010] According to the research conducted by the present inventors, it has been found that when electronic components are arranged on an adhesive film and sealed with a sealing material, the position of the electronic components may be misaligned (hereinafter also referred to as positional misalignment of the electronic components).

[0011] The present invention has been made in view of the above circumstances, and provides a method for manufacturing an electronic device capable of suppressing positional displacement of electronic components in a sealing step.

[0012] Methods for solving problems

[0013] The present inventors have conducted intensive studies to achieve the above-mentioned objectives and have found that the positional displacement of electronic components in the sealing process can be suppressed by performing a process of reducing the moisture content in an adhesive film or a process of reducing the moisture content in a structure including an adhesive film, thereby completing the present invention.

[0014] According to the present invention, there is provided a method for manufacturing an electronic device as shown below. [1]

[0016] A method for manufacturing an electronic device, comprising at least the following steps:

[0017] Step (1), preparing a structure comprising an adhesive film, an electronic component and a supporting substrate,

[0018] The adhesive film comprises: a base layer, an adhesive resin layer (A) provided on a first surface side of the base layer and used for temporarily fixing the electronic component, and an adhesive resin layer (B) provided on a second surface side of the base layer and having adhesive force reduced by external stimulation,

[0019] The electronic component is adhered to the adhesive resin layer (A) of the adhesive film.

[0020] The supporting substrate is adhered to the adhesive resin layer (B) of the adhesive film;

[0021] Step (2), at least one selected from the group consisting of step (2-1) of reducing the moisture content in the adhesive film and step (2-2) of reducing the moisture content in the structure; and

[0022] Step (3) of sealing the electronic component with a sealing material. [2]

[0024] According to the method for manufacturing an electronic device described in [1] above,

[0025] The step (2) includes a step (2-1) of reducing the water content in the adhesive film.

[0026] The above step (2-1) is performed before the above step (1). [3]

[0028] According to the method for manufacturing an electronic device described in [2] above,

[0029] In the step (2-1), the moisture content in the adhesive film is reduced by heating the adhesive film and / or reducing the pressure on the adhesive film. [4]

[0031] According to the method for manufacturing an electronic device described in [1] above,

[0032] The step (2) includes a step (2-2) of reducing the water content in the structure.

[0033] The step (2-2) is performed between the step (1) and the step (3). [5]

[0035] According to the method for manufacturing an electronic device described in [4] above,

[0036] In the step (2-2), the water content in the structure is reduced by heating the structure and / or reducing the pressure of the structure. [6]

[0038] According to the method for manufacturing an electronic device described in [4] or [5] above,

[0039] The above step (2) is performed immediately before the above step (3). [7]

[0041] The method for manufacturing an electronic device according to any one of [1] to [6] above,

[0042] After the step (3), the method further comprises the step (4) of reducing the adhesive force of the adhesive resin layer (B) by applying an external stimulus, thereby peeling the supporting substrate from the structure. [8]

[0044] According to the method for manufacturing an electronic device described in [7] above,

[0045] After the step (4), the method further includes the step (5) of peeling the adhesive film from the electronic component. [9]

[0047] The method for manufacturing an electronic device according to any one of [1] to [8] above,

[0048] The interval between the above step (2) and the above step (3) is within 12 hours.

[10]

[0050] The method for manufacturing an electronic device according to any one of [1] to [9] above,

[0051] The sealing material is an epoxy resin-based sealing material.

[11]

[0053] The method for manufacturing an electronic device according to any one of [1] to

[10] above,

[0054] The adhesive resin layer (A) contains a (meth)acrylic adhesive resin.

[0055] Effects of the Invention

[0056] According to the present invention, it is possible to provide a method for manufacturing an electronic device capable of suppressing positional displacement of an electronic component in a sealing step. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The above-mentioned object and other objects, features and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings.

[0058] Figure 1 This is a cross-sectional view schematically showing an example of the structure of the adhesive film according to the embodiment of the present invention.

[0059] Figure 2 It 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.

[0060] Figure 3 It 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.

[0061] Figure 4 It 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. DETAILED DESCRIPTION

[0062] Hereinafter, the embodiments of the present invention will be described using the accompanying drawings. In addition, in all the drawings, the same components are given common symbols and the description is appropriately omitted. In addition, the drawings are schematic diagrams and are not consistent with the actual dimensional ratios. In addition, the numerical range "A to B" means above A and below B unless otherwise specified. In addition, in the present embodiment, the so-called "(meth) acrylic acid" refers to acrylic acid, methacrylic acid, or both acrylic acid and methacrylic acid.

[0063] 1. Method for manufacturing electronic device

[0064] First, a method for manufacturing an electronic device according to this embodiment will be described. Figure 1 It is a cross-sectional view schematically showing an example of the structure of the adhesive film 50 according to the embodiment of the present invention.

[0065] Figures 2 to 4 It 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.

[0066] The method for manufacturing an electronic device according to the present embodiment includes at least the following three steps.

[0067] (1) a step of preparing a structure 100, the structure 100 comprising an adhesive film 50, an electronic component 70, and a supporting substrate 80, the adhesive film 50 comprising: a base material layer 10, an adhesive resin layer (A) provided on a first surface 10A side of the base material layer 10 and used for temporarily fixing the electronic component 70, and an adhesive resin layer (B) provided on a second surface 10B side of the base material layer 10 and having adhesive force reduced by external stimulation, the electronic component 70 being adhered to the adhesive resin layer (A) of the adhesive film 50, and the supporting substrate 80 being adhered to the adhesive resin layer (B) of the adhesive film 50,

[0068] (2) at least one step selected from the step (2-1) of reducing the moisture content in the adhesive film 50 and the step (2-2) of reducing the moisture content in the structure 100,

[0069] (3) A step of sealing the electronic component 70 with the sealing material 60 .

[0070] As described above, the present inventors have found through their studies that when electronic components are placed on an adhesive film and sealed with a sealing material, the electronic components may be misaligned (hereinafter also referred to as "positional misalignment of the electronic components").

[0071] The inventors of the present invention have repeatedly conducted in-depth research to achieve the above-mentioned problem. As a result, they have found that, in the process of sealing electronic components, the electronic components may be misaligned due to outgassing of moisture contained in the adhesive film, especially outgassing of moisture contained in the adhesive resin layer attached to the supporting substrate side.

[0072] Based on the above knowledge, the inventors of the present invention have conducted further repeated studies and have found for the first time that by performing at least one step (2) selected from the step (2-1) of reducing the moisture content in the adhesive film 50 and the step (2-2) of reducing the moisture content in the structure 100, it is possible to suppress the positional displacement of the electronic components in the sealing step.

[0073] That is, according to the manufacturing method of the electronic device involved in this embodiment, by performing at least one step (2) selected from the step (2-1) of reducing the moisture content in the adhesive film 50 and the step (2-2) of reducing the moisture content in the structure 100, in the process of sealing the electronic components, the outgassing of moisture contained in the adhesive film, especially the outgassing of moisture contained in the adhesive resin layer adhered to the supporting substrate side, can be suppressed, as a result, the positional misalignment of the electronic components in the sealing process can be suppressed.

[0074] As described above, according to the method for manufacturing an electronic device according to the present embodiment, it is possible to suppress positional displacement of electronic components in the sealing step.

[0075] Hereinafter, each step of the method for manufacturing the electronic device according to the present embodiment will be described.

[0076] (Process (1))

[0077] In step (1), a structure 100 including an adhesive film 50 , an electronic component 70 attached to an adhesive resin layer (A) of the adhesive film 50 , and a supporting substrate 80 attached to an adhesive resin layer (B) of the adhesive film 50 is prepared.

[0078] Such a structure 100 can be produced, for example, by the following steps.

[0079] First, the adhesive film 50 is attached to the support substrate 80 in such a manner that the adhesive resin layer (B) is on the support substrate 80 side. A protective film may also be attached to the adhesive resin layer (B), and the exposed surface of the adhesive resin layer (B) can be attached to the support substrate 80 surface by peeling off the protective film.

[0080] As the support substrate 80 , for example, a quartz substrate, a glass substrate, a SUS substrate, or the like can be used.

[0081] Next, by placing the electronic component 70 on the adhesive resin layer (A) of the adhesive film 50 attached to the supporting substrate 80 , the structure 100 can be obtained.

[0082] Examples of the electronic component 70 include semiconductor chips such as ICs, LSIs, discrete devices, light emitting diodes, and light receiving elements, semiconductor panels, and semiconductor packages.

[0083] (Process (2))

[0084] The step (2) includes at least one step selected from the step (2-1) of reducing the moisture content in the adhesive film 50 and the step (2-2) of reducing the moisture content in the structure 100 .

[0085] Step (2-1) Figure 2 As shown in FIG. 1 , it is preferably performed before step (1). That is, it is preferable to reduce the moisture content in the adhesive film 50 at a stage before the structure 100 is produced. By doing so, the moisture content in the adhesive film 50 at a stage before being cut into an appropriate size, for example, in a rolled state, can be reduced, and the moisture content in the structure 100 can be reduced more efficiently.

[0086] In the step (2-1), for example, the moisture content in the adhesive film 50 can be reduced by heating the adhesive film 50 and / or reducing the pressure on the adhesive film 50 .

[0087] On the other hand, step (2-2) is as follows Figure 3 As shown, it is preferably performed between step (1) and step (3), and more preferably performed immediately before step (3). By performing step (2-2) immediately before step (3), positional displacement of electronic components in the sealing step can be further suppressed.

[0088] In the step (2-2), for example, the water content in the structure 100 can be reduced by heating the structure 100 and / or reducing the pressure of the structure 100 .

[0089] In the manufacturing method of the electronic device involved in the present embodiment, the interval between step (2) and step (3) is preferably within 12 hours, more preferably within 6 hours, further preferably within 3 hours, and particularly preferably within 1 hour. By doing so, it is possible to suppress the moisture in the atmosphere from being adsorbed on the adhesive film 50 and the structure 100 between steps (2) and (3). Thus, in the process of sealing the electronic components, it is possible to further suppress the outgassing of moisture contained in the adhesive film 50 and the structure 100, and as a result, it is possible to further suppress the positional misalignment of the electronic components in the sealing process.

[0090] In step (2), the temperature at which the adhesive film 50 or the structure 100 is heated is not particularly limited as long as it is a temperature that can reduce the amount of moisture contained in the adhesive film 50 or the structure 100 and does not cause degradation of the adhesive film 50 or the structure 100. For example, it is preferably in the range of 80°C to 180°C, and more preferably in the range of 100°C to 150°C.

[0091] The time for heating the adhesive film 50 or the structure 100 is not particularly limited as long as it is a heating time that can reduce the moisture content in the adhesive film 50 or the structure 100 and does not cause degradation of the adhesive film 50 or the structure 100. For example, it is within the range of 1 minute to 120 minutes, and preferably within the range of 5 minutes to 60 minutes.

[0092] The method of heating the adhesive film 50 or the structure 100 is not particularly limited, and for example, a generally known heating treatment method such as an oven, a dryer, a heating roll, a drying furnace, etc. can be used.

[0093] When the pressure of the adhesive film 50 or the structure 100 is reduced, the pressure during the reduction of pressure is, for example, 100 Pa or more and 10000 Pa or less.

[0094] The method for reducing the pressure of the adhesive film 50 or the structure 100 is not particularly limited, and for example, a generally known method for reducing the pressure, such as a vacuum dryer, can be used.

[0095] The moisture content can be adjusted by heating or reducing the pressure of the adhesive film 50 or the structure 100 as described above. When heated at a temperature exceeding 125° C., the pressure during the reduction is preferably set to 500 Pa or more in order to prevent separation of the electronic component 70 and the adhesive film 50 .

[0096] Whether the moisture content in the adhesive film 50 or the structure 100 has decreased can be determined by, for example, a known method such as thermogravimetric analysis.

[0097] (Process (3))

[0098] Next, the electronic component 70 is sealed with the sealing material 60 .

[0099] The electronic component 70 is covered with the sealing material 60 , and the sealing material 60 is cured at a temperature of 150° C. or less, for example, to seal the electronic component 70 .

[0100] The form of the sealing material 60 is not particularly limited, and may be, for example, a granular form, a sheet form, or a liquid form.

[0101] The sealing material 60 is not particularly limited, and for example, an epoxy resin-based sealing material using epoxy resin can be used.

[0102] In particular, a liquid epoxy resin-based sealing material is preferred because the sealing material 60 has a better affinity for the adhesive film 50 and can seal the electronic component 70 more evenly.

[0103] As such an epoxy resin-based sealing material, for example, T693 / R4000 series, T693 / R1000 series, T693 / R5000 series, etc. manufactured by Nagase Chemtex Corporation can be used.

[0104] Examples of sealing methods include transfer molding, injection molding, compression molding, and casting molding. After sealing the electronic component 70 with the sealing material 60, the sealing material 60 is cured by heating at a temperature of 150°C or less, thereby obtaining the structure 100 in which the electronic component 70 is sealed.

[0105] (Process (4))

[0106] In the method for manufacturing an electronic device according to this embodiment, Figure 4As shown, after step (3), there may be further included a step (4) of reducing the adhesive force of the adhesive resin layer (B) by applying an external stimulus to peel the supporting substrate 80 from the structure 100 .

[0107] The support substrate 80 can be easily removed from the adhesive film 50 by, for example, heating the electronic component 70 to a temperature exceeding 150° C. after sealing the electronic component 70 to reduce the adhesive force of the adhesive resin layer (B).

[0108] (Process (5))

[0109] In the method for manufacturing an electronic device according to this embodiment, Figure 4 As shown, after step (4), step (5) of peeling the adhesive film 50 from the electronic component 70 to obtain the electronic device 200 may be further included.

[0110] Examples of a method for peeling the adhesive film 50 from the electronic component 70 include a method of mechanically peeling the adhesive film 50 and a method of peeling the adhesive film 50 after reducing the adhesive force on the surface of the adhesive film 50 .

[0111] (Process (6))

[0112] In the method for manufacturing an electronic device according to this embodiment, Figure 4 As shown, the method may further include forming a wiring layer 310 and a bump 320 on the exposed surface of the obtained electronic device 200 to obtain the electronic device 300 (6).

[0113] The wiring layer 310 includes pads (not shown) formed on the outermost surface as external connection terminals and wiring (not shown) electrically connecting the exposed electronic components 70 to the pads. The wiring layer 310 can be formed by a conventionally known method and may have a multilayer structure.

[0114] Furthermore, a bump 320 can be formed on the pad of the wiring layer 310 to obtain the electronic device 300. Examples of the bump 320 include a solder bump and a gold bump. The solder bump can be formed, for example, by placing a solder ball on the pad as the external connection terminal of the wiring layer 310 and heating the solder to melt (reflow). The gold bump can be formed by a ball soldering method, a plating method, an Au ball transfer method, or the like.

[0115] (Process (7))

[0116] In the method for manufacturing an electronic device according to this embodiment, Figure 4 As shown, the method may further include a step (7) of cutting the electronic device 300 to obtain a plurality of electronic devices 400 .

[0117] The electronic device 300 can be cut using a known method.

[0118] 2. Adhesive film

[0119] Hereinafter, the adhesive film 50 according to the present embodiment will be described.

[0120] Figure 1 It is a cross-sectional view schematically showing an example of the structure of the adhesive film 50 according to the embodiment of the present invention.

[0121] like Figure 1 As shown, the adhesive film 50 involved in this embodiment comprises: a substrate layer 10, an adhesive resin layer (A) arranged on the first surface 10A side of the substrate layer 10, and an adhesive resin layer (B) arranged on the second surface 10B side of the substrate layer 10 and the adhesive force of which is reduced due to external stimulation.

[0122] The entire thickness of the adhesive film 50 according to the present embodiment is preferably from 10 μm to 1000 μm, and more preferably from 20 μm to 500 μm, from the viewpoint of the balance between mechanical properties and handling properties.

[0123] Next, each layer constituting the adhesive film 50 according to the present embodiment will be described.

[0124] <Base material layer>

[0125] The base material layer 10 is a layer provided for the purpose of improving the handling properties, mechanical properties, heat resistance and other properties of the adhesive film 50 .

[0126] The base material layer 10 is not particularly limited, and an example thereof may be a resin film.

[0127] As the resin constituting the above-mentioned resin film, a known thermoplastic resin can be used. For example, one or more of the following can be cited: 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 poly(m-phenylene adipamide); polyacrylates; polymethacrylates; polyvinyl chloride; polyvinylidene chloride; polyimides; polyetherimides; ethylene-vinyl acetate copolymers; polyacrylonitrile; polycarbonates; polystyrenes; ionomers; polysulfones; polyethersulfones; and polyphenylene oxides.

[0128] Among these, from the viewpoint of excellent balance among transparency, mechanical strength, price, etc., preferably, one or more selected from polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyimide are used, and more preferably, at least one selected from polyethylene terephthalate and polyethylene naphthalate are used.

[0129] The base layer 10 may be a single layer or may be two or more layers.

[0130] The resin film used to form the substrate layer 10 may be a stretched film or a uniaxially or biaxially stretched film. From the perspective of improving the mechanical strength of the substrate layer 10 , a uniaxially or biaxially stretched film is preferred.

[0131] The thickness of the base layer 10 is preferably 1 μm to 500 μm, more preferably 5 μm to 300 μm, and further preferably 10 μm to 250 μm, from the viewpoint of obtaining good film properties.

[0132] In order to improve the adhesion with other layers, the base material layer 10 may be subjected to a surface treatment. Specifically, a corona treatment, a plasma treatment, an undercoat treatment, a primer coat treatment, etc. may be performed.

[0133] <Adhesive resin layer (A)>

[0134] The adhesive resin layer (A) is a layer provided on one surface of the base layer 10 and is a layer for temporarily fixing the electronic component by contacting the surface of the electronic component when the electronic component is sealed with a sealing material in the manufacturing process of the electronic device.

[0135] The adhesive resin layer (A) contains an adhesive resin (A1).

[0136] Examples of the adhesive resin (A1) include (meth)acrylic adhesive resins (a), silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins.

[0137] Among these, the (meth)acrylic adhesive resin (a) is preferred from the viewpoint of facilitating the adjustment of adhesive strength.

[0138] As the adhesive resin layer (A), a radiation cross-linked adhesive resin layer whose adhesive force is reduced by radiation can also be used. Since the radiation cross-linked adhesive resin layer is cross-linked by radiation irradiation, the adhesive force is significantly reduced, so it becomes easy to peel the adhesive film 50 from the electronic component. Examples of radiation include ultraviolet rays, electron beams, infrared rays, etc.

[0139] As the radiation cross-linkable adhesive resin layer, an ultraviolet cross-linkable adhesive resin layer is preferable.

[0140] Examples of the (meth)acrylic adhesive resin (a) used in the adhesive resin layer (A) include copolymers containing (meth)acrylic acid alkyl ester monomer units (a1) and monomer units (a2) having a functional group reactive with a crosslinking agent.

[0141] In the present embodiment, the (meth)acrylic acid alkyl ester refers to an acrylate alkyl ester, a methacrylate alkyl ester, or a mixture thereof.

[0142] The (meth)acrylic adhesive resin (a) according to the present 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 reactive with a crosslinking agent.

[0143] As the monomer (a1) forming the (meth)acrylic acid alkyl ester monomer unit (a1), there can be mentioned an (meth)acrylic acid alkyl ester having an alkyl group with about 1 to 12 carbon atoms. It is preferably an (meth)acrylic acid alkyl ester having an alkyl group with 1 to 8 carbon atoms. Specifically, there can be mentioned methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, etc. These can be used alone or in combination of two or more.

[0144] In the (meth)acrylic adhesive resin (a) according to the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is taken as 100 mass %, the content of the (meth)acrylic acid alkyl ester monomer unit (a1) is preferably 10 mass % to 98.9 mass %, more preferably 50 mass % to 97 mass %, and even more preferably 85 mass % to 95 mass %.

[0145] As the monomer (a2) forming the monomer unit (a2) having a functional group capable of reacting with a crosslinking agent, acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, itaconic acid monoalkyl esters, mesaconic acid monoalkyl esters, citraconic acid monoalkyl esters, fumaric acid monoalkyl esters, maleic acid monoalkyl esters, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tert-butylaminoethyl acrylate, tert-butylaminoethyl methacrylate, etc. are mentioned. Preferred are acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, etc. These can be used alone or in combination of two or more.

[0146] In the (meth)acrylic adhesive resin (a) involved in the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is set to 100 mass%, the content of the monomer unit (a2) is preferably 1 mass% to 40 mass%, more preferably 1 mass% to 20 mass%, and further preferably 1 mass% to 10 mass%.

[0147] The (meth)acrylic adhesive resin (a) according to the present embodiment may further contain, in addition to the monomer units (a1) and (a2), a bifunctional monomer unit (a3) ​​and a specific comonomer (hereinafter referred to as a polymerizable surfactant) unit having a property as a surfactant.

[0148] The polymerizable surfactant has a property of copolymerizing with the monomer (a1), the monomer (a2), and the monomer (a3), and functions as an emulsifier when emulsion polymerization is performed.

[0149] Examples of the monomer (a3) ​​forming the bifunctional monomer unit (a3) ​​include allyl methacrylate, allyl acrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tetraethylene glycol di(meth)acrylate, and a main chain structure having diacrylate or dimethacrylate at both ends and propylene glycol (e.g., manufactured by NOF Corporation, Monomers of 1,4-butanediol type (e.g., NOF Corporation, trade name: ADT-250, NOF Corporation, ADT-850) and mixed types thereof (e.g., NOF Corporation, trade name: ADET-1800, NOF Corporation, ADPT-4000) and the like.

[0150] In the (meth)acrylic adhesive resin (a) involved in the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is set to 100 mass%, the content of the monomer unit (a3) ​​is preferably 0.1 mass% to 30 mass%, more preferably 0.1 mass% to 15 mass%, further preferably 0.1 mass% to 20 mass%, and particularly preferably 0.1 mass% to 5 mass%.

[0151] Examples of polymerizable surfactants include those having a polymerizable 1-propenyl group introduced into the benzene ring of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: Aqualon RN-10, Aqualon RN-20, Aqualon RN-30, Aqualon RN-50, etc.), those having a polymerizable 1-propenyl group 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, Aqualon HS-20, Aqualon HS-1025, etc.), and sulfosuccinic acid diesters having a polymerizable double bond in the molecule (manufactured by Kao Corporation; trade names: Latemul S-120A, Latemul S-180A, etc.).

[0152] In the (meth)acrylic adhesive resin (a) involved in the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is set to 100 mass%, the content of the polymerizable surfactant is preferably 0.1 mass% to 30 mass%, more preferably 0.1 mass% to 15 mass%, further preferably 0.1 mass% to 20 mass%, and particularly preferably 0.1 mass% to 5 mass%.

[0153] The (meth)acrylic adhesive resin (a) according to the present embodiment may further contain a monomer unit composed of a monomer having a polymerizable double bond such as vinyl acetate, acrylonitrile, or styrene, as necessary.

[0154] The polymerization reaction mechanism of the (meth)acrylic adhesive resin (a) according to the present embodiment includes free radical polymerization, anionic polymerization, cationic polymerization, etc. If the manufacturing cost of the (meth)acrylic adhesive resin (a), the influence of the functional groups of the monomers, and the influence of ions on the surface of the electronic components are taken into consideration, polymerization by free radical polymerization is preferred.

[0155] Examples of the radical polymerization initiator used in the case of performing polymerization by radical polymerization include organic peroxides such as benzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, 3,3,5-trimethylhexanoyl peroxide, di-2-ethylhexyl peroxydicarbonate, methyl ethyl ketone peroxide, tert-butyl peroxyphthalate, tert-butyl peroxybenzoate, di-tert-butyl peroxyacetate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-2-hexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, tert-butyl peroxide, and di-tert-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.

[0156] When polymerization is performed by emulsion polymerization, among these free radical polymerization initiators, preferred are water-soluble inorganic peroxides such as ammonium persulfate, potassium persulfate, and sodium persulfate, and water-soluble azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid. Considering the influence of ions on the surface of electronic components, more preferred are azo compounds having a carboxyl group in the molecule such as ammonium persulfate and 4,4'-azobis-4-cyanovaleric acid, and particularly preferred are azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid.

[0157] The adhesive resin layer (A) according to the present embodiment preferably further contains a crosslinking agent (A2) having two or more crosslinkable functional groups in one molecule in addition to the adhesive resin (A1).

[0158] The crosslinking agent (A2) having two or more crosslinkable functional groups in one molecule is reacted with the functional group of the adhesive resin (A1) to adjust the adhesive strength and cohesive force.

[0159] Examples of such a crosslinking agent (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 tri-adduct of trimethylolpropane, polyisocyanates, diphenylmethane diisocyanate, and toluene diisocyanate; trimethylolpropane-tri-β-aziridinyl propionate, tetramethylolmethane-tri-isocyanate, and isocyanate-based compounds. Aziridine compounds such as 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; melamine compounds such as hexamethoxymethylolmelamine, etc. These compounds may be used alone or in combination of two or more.

[0160] Among these, it is preferred that one or two or more selected from epoxy compounds, isocyanate compounds and aziridine compounds are contained.

[0161] The content of the crosslinking agent (A2) is preferably within a range where the number of functional groups in the crosslinking agent (A2) is not more than the number of functional groups in the adhesive resin (A1). However, in the case where new functional groups are generated during the crosslinking reaction or the crosslinking reaction is slow, an excessive amount may be contained as needed.

[0162] 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 relative to 100 parts by mass of the adhesive resin (A1) from the viewpoint of improving the balance between the heat resistance and the adhesion of the adhesive resin layer (A).

[0163] When the whole of the adhesive resin layer (A) is set to 100 mass %, the total content of the adhesive resin (A1) and the crosslinking agent (A2) in the adhesive resin layer (A) is preferably 50 mass % to 100 mass %, more preferably 70 mass % to 100 mass %, further preferably 90 mass % to 100 mass %, particularly preferably 95 mass % to 100 mass %. Thus, it is possible to further suppress the residual adhesive on the electronic component side when the adhesive film is peeled off from the electronic component.

[0164] The thickness of the adhesive resin layer (A) is not particularly limited, but is, for example, preferably from 1 μm to 100 μm, and more preferably from 3 μm to 50 μm.

[0165] The adhesive resin layer (A) can be formed, for example, by coating an adhesive on the base layer 10. The adhesive may be dissolved in a solvent and applied as a coating liquid, may be applied as an aqueous emulsion, or may be directly applied as a liquid adhesive.

[0166] Among them, aqueous emulsion coating liquids are preferred. Examples of aqueous emulsion coating liquids include coating liquids prepared by dispersing (meth)acrylic adhesive resins (a), silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, styrene adhesive resins, and the like in water.

[0167] 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 based on solubility and drying time. Examples of organic solvents include esters such as ethyl acetate and methyl acetate; ketones such as acetone and MEK; aromatics such as benzene, toluene, and ethylbenzene; linear or cyclic aliphatic systems such as heptane, hexane, and cyclohexane; and alcohols such as isopropanol and butanol. Ethyl acetate and toluene are preferred organic solvents. One of these solvents may be used alone, or two or more may be mixed and used.

[0168] As a method for applying the adhesive coating liquid, a conventionally known coating method can be used, for example, a roller coater method, a reverse roller coater method, a gravure roller method, a rod coating method, a notch wheel coater method, a die coating method, etc. The drying conditions of the adhesive after coating are not particularly limited. Generally speaking, it is preferably dried for 10 seconds to 10 minutes at a temperature range of 80 to 200° C. It is further preferably dried for 15 seconds to 5 minutes at 80 to 170° C. In order to fully promote the crosslinking reaction of the crosslinking agent and the adhesive, the adhesive coating liquid can be heated at 40 to 80° C. for about 5 to 300 hours after the drying of the adhesive coating liquid is completed.

[0169] The base layer 10 and the adhesive resin layer (A) may be formed by co-extrusion molding, or may be formed by laminating (stacking) a film-like base layer 10 and a film-like adhesive resin layer (A).

[0170] <Adhesive resin layer (B)>

[0171] The adhesive film 50 according to the present embodiment includes an adhesive resin layer (B) whose adhesive force is reduced by external stimulation on the second surface 10B side of the base layer 10 opposite to the first surface 10A.

[0172] Thus, the adhesive film 50 can be easily peeled off from the supporting substrate 80 by applying an external stimulus.

[0173] Here, as the adhesive resin layer (B) whose adhesive force is reduced by external stimulation, for example, a heat-peelable adhesive resin layer whose adhesive force is reduced by heating, a radiation-peelable adhesive resin layer whose adhesive force is reduced by radiation, etc. Among these, a heat-peelable adhesive resin layer whose adhesive force is reduced by heating is preferred.

[0174] As the heat-peelable adhesive resin layer, for example, there can be mentioned an adhesive resin layer composed of a heat-expandable adhesive containing a gas-generating component, a heat-expandable adhesive containing heat-expandable microspheres that can expand and reduce adhesive strength, a heat-expandable adhesive in which the adhesive component undergoes a cross-linking reaction due to heat to reduce adhesive strength, and the like.

[0175] In the present embodiment, the heat-expandable adhesive used for the adhesive resin layer (B) is an adhesive whose adhesive force is reduced or lost by heating at a temperature exceeding 150° C. For example, a material that does not peel at a temperature below 150° C. but peels at a temperature exceeding 150° C. can be selected, and preferably has an adhesive force to the extent that the adhesive film 50 does not peel off from the supporting substrate 80 during the manufacturing process of the electronic device.

[0176] Here, about the adhesive force reduction or loss by heating at a temperature exceeding 150°C, for example, it can be evaluated as follows: the adhesive resin layer (B) side is pasted on a stainless steel plate, heat treated for 1 hour at 140°C, then heated for 2 minutes at a temperature exceeding 150°C, and evaluated by the peel strength from the stainless steel plate measured thereafter. About the specific heating temperature when heating at a temperature exceeding 150°C, it is set to a temperature higher than the temperature at which the temperature of the generated gas and the heat-expandable microspheres undergo thermal expansion, and is appropriately set according to the type of the generated gas and the heat-expandable microspheres. In the present embodiment, the so-called adhesive force loss refers to, for example, the situation that the 180° peel strength obtained by measuring under the conditions of 23°C, a tensile speed of 300mm / minute is less than 0.5N / 25mm.

[0177] As the gas generating component used for the heat-expandable adhesive, for example, an azo compound, an azide compound, a Meldrum's acid derivative, etc. can be used. In addition, inorganic foaming agents such as ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium borohydroxide, various azides, and the like, water; chlorofluoroalkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate; hydrazine compounds such as p-toluenesulfonylhydrazine, diphenylsulfone-3,3'-disulfonylhydrazine, 4,4'-oxybis(benzenesulfonylhydrazine), and allylbis(sulfonylhydrazine); semicarbazide compounds such as p-tolylsulfonylsemicarbazide and 4,4'-oxybis(benzenesulfonylsemicarbazide); triazole compounds such as 5-morpholinyl-1,2,3,4-thiatriazole; organic foaming agents such as N-nitroso compounds such as N,N'-dinitrosopentamethylenetetramine and N,N'-dimethyl-N,N'-dinitrosoterephthalamide, and the like can also be used. The gas generating component may be added to the adhesive resin (B1) or may be directly bonded to the adhesive resin (B1).

[0178] As the heat-expandable microsphere used by the heat-expandable adhesive, it is possible to use, for example, a microencapsulated foaming agent. As such heat-expandable microsphere, for example, isobutane, propane, pentane, etc. can be enumerated, and the material that is easily gasified and expanded by heating is encapsulated in the microsphere in the shell with elasticity, etc. As the material constituting the above-mentioned shell, for example, vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, polysulfone, etc. can be enumerated. Heat-expandable microsphere, for example, can be manufactured by coagulation (coacervation) method, interfacial polymerization method, etc.

[0179] Heat-expandable microspheres can be added to the adhesive resin.

[0180] The content of at least one selected from the group consisting of the gas generating component and the heat-expandable microspheres can be appropriately set according to the expansion ratio of the heat-peelable adhesive resin layer (B), the reduction in adhesive force, etc., and is not particularly limited. For example, relative to 100 parts by mass of the adhesive resin (B1) in the heat-peelable adhesive resin layer (B), it is, for example, 1 part by mass to 150 parts by mass, preferably 10 parts by mass to 130 parts by mass, and further preferably 12 parts by mass to 100 parts by mass.

[0181] It is preferable to design the temperature at which the gas is generated and the temperature at which the heat-expandable microspheres thermally expand to be higher than 150°C.

[0182] As the adhesive resin (B1) constituting the heat-expandable adhesive, for example, (meth)acrylic resin (b), urethane resin, silicone resin, polyolefin resin, polyester resin, polyamide resin, fluorine resin, styrene-diene block copolymer resin, etc. Among these, (meth)acrylic resin (b) is preferred.

[0183] Examples of the (meth)acrylic adhesive resin (b) used in the adhesive resin layer (B) include copolymers containing (meth)acrylic acid alkyl ester monomer units (b1) and monomer units (b2) having a functional group reactive with a crosslinking agent.

[0184] In the present embodiment, the (meth)acrylic acid alkyl ester refers to an acrylate alkyl ester, a methacrylate alkyl ester, or a mixture thereof.

[0185] The (meth)acrylic adhesive resin (b) according to the present 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 reactive with a crosslinking agent.

[0186] As the monomer (b1) forming the (meth)acrylic acid alkyl ester monomer unit (b1), there can be mentioned (meth)acrylic acid alkyl esters having an alkyl group with about 1 to 12 carbon atoms. It is preferably (meth)acrylic acid alkyl esters having an alkyl group with 1 to 8 carbon atoms. Specifically, there can be mentioned methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, etc. These can be used alone or in combination of two or more.

[0187] In the (meth)acrylic adhesive resin (b) involved in the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is set to 100 mass%, the content of the (meth)acrylic acid alkyl ester monomer unit (b1) is preferably 10 mass% to 98.9 mass%, more preferably 50 mass% to 97 mass%, and further preferably 85 mass% to 95 mass%.

[0188] As the monomer (b2) forming the monomer unit (b2) having a functional group that can react with a crosslinking agent, 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, tert-butylaminoethyl methacrylate, etc. are mentioned. Preferred are acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, etc. They can be used alone or in combination.

[0189] In the (meth)acrylic adhesive resin (b) involved in the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is set to 100 mass%, the content of the monomer unit (b2) is preferably 1 mass% to 40 mass%, more preferably 1 mass% to 20 mass%, and further preferably 1 mass% to 10 mass%.

[0190] The (meth)acrylic adhesive resin (b) according to the present embodiment may further contain, in addition to the monomer units (b1) and (b2), bifunctional monomer units (b3) and specific comonomer units (hereinafter referred to as polymerizable surfactants) having properties as surfactants.

[0191] The polymerizable surfactant has a property of copolymerizing with the monomer (b1), the monomer (b2), and the monomer (b3), and functions as an emulsifier when emulsion polymerization is performed.

[0192] Examples of the monomer (b3) forming the bifunctional monomer unit (b3) include allyl methacrylate, allyl acrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tetraethylene glycol di(meth)acrylate, and a main chain structure having diacrylate or dimethacrylate at both ends and propylene glycol (e.g., manufactured by NOF Corporation, Monomers of 1,4-butanediol type (e.g., NOF Corporation, trade name: ADT-250, NOF Corporation, ADT-850) and mixed types thereof (e.g., NOF Corporation, trade name: ADET-1800, NOF Corporation, ADPT-4000) and the like.

[0193] In the (meth)acrylic adhesive resin (b) involved in the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is set to 100 mass%, the content of the monomer unit (b3) is preferably 0.1 mass% to 30 mass%, more preferably 0.1 mass% to 15 mass%, further preferably 0.1 mass% to 20 mass%, and particularly preferably 0.1 mass% to 5 mass%.

[0194] Examples of polymerizable surfactants include those having a polymerizable 1-propenyl group introduced into the benzene ring of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: Aqualon RN-10, Aqualon RN-20, Aqualon RN-30, Aqualon RN-50, etc.), those having a polymerizable 1-propenyl group 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, Aqualon HS-20, Aqualon HS-1025, etc.), and sulfosuccinic acid diesters having a polymerizable double bond in the molecule (manufactured by Kao Corporation; trade names: Latemul S-120A, Latemul S-180A, etc.).

[0195] In the (meth)acrylic adhesive resin (b) involved in the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is set to 100 mass%, the content of the polymerizable surfactant is preferably 0.1 mass% to 30 mass%, more preferably 0.1 mass% to 15 mass%, further preferably 0.1 mass% to 20 mass%, and particularly preferably 0.1 mass% to 5 mass%.

[0196] The (meth)acrylic adhesive resin (b) according to the present embodiment may further contain a monomer unit formed from a monomer having a polymerizable double bond such as vinyl acetate, acrylonitrile, or styrene, as necessary.

[0197] The polymerization reaction mechanism of the (meth)acrylic adhesive resin (b) according to the present embodiment includes free radical polymerization, anionic polymerization, cationic polymerization, etc. If the manufacturing cost of the (meth)acrylic adhesive resin (b), the influence of the functional groups of the monomers, and the influence of ions on the surface of the electronic components are taken into consideration, polymerization by free radical polymerization is preferred.

[0198] Examples of the radical polymerization initiator used in the case of performing polymerization by radical polymerization include organic peroxides such as benzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, 3,3,5-trimethylhexanoyl peroxide, di-2-ethylhexyl peroxydicarbonate, methyl ethyl ketone peroxide, tert-butyl peroxyphthalate, tert-butyl peroxybenzoate, di-tert-butyl peroxyacetate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-2-hexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, tert-butyl peroxide, and di-tert-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.

[0199] When the polymerization is carried out by emulsion polymerization, among these free radical polymerization initiators, water-soluble inorganic peroxides such as ammonium persulfate, potassium persulfate, and sodium persulfate, and water-soluble azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid are preferred. Considering the influence of ions on the surface of electronic components, azo compounds having a carboxyl group in the molecule such as ammonium persulfate and 4,4'-azobis-4-cyanovaleric acid are more preferred, and azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid are particularly preferred.

[0200] The adhesive resin layer (B) according to the present embodiment preferably further contains a crosslinking agent (B2) having two or more crosslinkable functional groups in one molecule in addition to the adhesive resin (B1) from the viewpoint of further suppressing positional displacement of electronic components in the sealing step.

[0201] The crosslinking agent (B2) having two or more crosslinkable functional groups in one molecule is reacted with the functional group of the adhesive resin (B1) to adjust the adhesive strength and cohesive force.

[0202] Examples of such a crosslinking agent (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 tri-adduct of trimethylolpropane, polyisocyanates, diphenylmethane diisocyanate, and toluene diisocyanate; trimethylolpropane-tri-β-aziridinyl propionate, tetramethylolmethane-tri-isocyanate, and isocyanate-based compounds. Aziridine compounds such as 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; melamine compounds such as hexamethoxymethylolmelamine, etc. These compounds may be used alone or in combination of two or more.

[0203] Among these, it is preferred that one or two or more selected from epoxy compounds, isocyanate compounds and aziridine compounds are contained.

[0204] The content of the crosslinking agent (B2) is preferably within a range where the number of functional groups in the crosslinking agent (B2) is not more than the number of functional groups in the adhesive resin (B1). However, in the case where new functional groups are generated during the crosslinking reaction or the crosslinking reaction is slow, an excessive amount may be contained as needed.

[0205] The content of the cross-linking agent (B2) in the adhesive resin layer (B) is preferably from 0.1 to 10 parts by mass, and more preferably from 0.5 to 5 parts by mass, relative to 100 parts by mass of the adhesive resin (B1).

[0206] When the whole of the adhesive resin layer (B) is set to 100 mass %, the total content of the adhesive resin (B1) and the crosslinking agent (B2) in the adhesive resin layer (B) is preferably 50 mass % to 100 mass %, more preferably 70 mass % to 100 mass %, further preferably 90 mass % to 100 mass %, and particularly preferably 95 mass % to 100 mass %. Thus, the positional misalignment of the electronic components in the sealing process can be further suppressed.

[0207] When the entire adhesive resin layer (B) is set to 100 mass%, the total content of the adhesive resin (B1), the crosslinking agent (B2) and at least one selected from the gas generating component and the heat-expandable microspheres in the adhesive resin layer (B) is preferably from 50 mass% to 100 mass%, more preferably from 70 mass% to 100 mass%, further preferably from 90 mass% to 100 mass%, and particularly preferably from 95 mass% to 100 mass%.

[0208] In addition, in the adhesive film 50 involved in the present embodiment, from the viewpoint of reducing the adhesion of the adhesive resin layer (B) by applying external stimulation, and stably maintaining the electronic components on the adhesive resin layer (A) when the supporting substrate is peeled off from the adhesive resin layer (B), when the entire adhesive resin layer (A) is set to 100 mass%, the content of at least one selected from gas generating components and heat-expandable microspheres in the adhesive resin layer (A) is preferably 0.1 mass% or less, more preferably 0.05 mass% or less, further preferably 0.01 mass% or less, and particularly preferably not containing at least one selected from gas generating components and heat-expandable microspheres in the adhesive resin layer (A).

[0209] In the adhesive resin layer (B) involved in the present embodiment, from the viewpoint of improving the adhesion to the supporting substrate, in addition to the adhesive resin (B1), it is preferred to include a tackifying resin. The adhesive resin layer (B) contains a tackifying resin, which makes it easy to adjust the adhesion to the supporting substrate near room temperature, so it is preferred. As a tackifying resin, a tackifying resin having a softening point of 100°C or above is preferred. Specific examples of tackifying resins include rosin-based resins such as rosin-based derivatives that have been subjected to esterification or the like; terpene resins such as α-pinene, β-pinene, dipentene, and terpene phenol; natural rosins such as rubber, wood, and tall oil; these natural rosins have been hydrogenated, disproportionated, polymerized, and maleicated; petroleum resins; coumarone-indene resins, etc.

[0210] Among them, a tackifying resin having a softening point in the range of 100 to 160° C. is more preferred, and a tackifying resin having a softening point in the range of 120 to 150° C. is particularly preferred. If a tackifying resin having a softening point in the above range is used, not only will there be less contamination and residual adhesive on the supporting substrate, but also the adhesion with the supporting substrate in the operating environment can be further improved. Furthermore, if a polymerized rosin ester-based tackifying resin is used as the tackifying resin, not only will there be less contamination and residual adhesive on the supporting substrate, but also the adhesion with the supporting substrate in an environment of 80 to 130° C. is improved, and after the expansion of the heat-expandable microspheres, it can be more easily peeled off from the supporting substrate.

[0211] Regarding the mixing ratio of the tackifying resin, as long as it is appropriately selected in a manner that the elastic modulus of the adhesive resin layer (B) can be adjusted to a desired predetermined numerical range, there is no particular restriction. However, from the elastic modulus and initial peeling force of the adhesive resin layer (B), it is preferably 1 to 100 parts by mass relative to 100 parts by mass of the adhesive resin (B1). If the mixing ratio of the tackifying resin is above the above lower limit relative to 100 parts by mass of the adhesive resin (B1), there is a tendency that the adhesion to the support substrate during operation becomes good. On the other hand, if it is below the above upper limit, there is a tendency that the adhesion to the support substrate at room temperature becomes good. From the perspective of the adhesion to the support substrate and the adhesion at room temperature, it is further preferred that the mixing ratio of the tackifying resin is 2 to 50 parts by mass relative to 100 parts by mass of the adhesive resin (B1). In addition, the acid value of the tackifying resin is preferably less than 30. If the acid value of the tackifying resin is below the above upper limit, there is a tendency that it is difficult for the support substrate to have residual glue when peeling.

[0212] The thickness of the adhesive resin layer (B) is not particularly limited, but is, for example, preferably from 5 μm to 300 μm, and more preferably from 20 μm to 150 μm.

[0213] The adhesive resin layer (B) can be formed, for example, by a method of applying an adhesive coating liquid on the base layer 10 or a method of transferring the adhesive resin layer (B) formed on the separator to the base layer 10 .

[0214] As a method for applying the adhesive coating liquid, a conventionally known coating method can be used, for example, a roller coater method, a reverse roller coater method, a gravure roller method, a rod coating method, a notch wheel coater method, a die coating method, etc. The drying conditions of the adhesive after coating are not particularly limited. Generally speaking, it is preferably dried for 10 seconds to 10 minutes at a temperature range of 80 to 200° C. It is further preferably dried for 15 seconds to 5 minutes at 80 to 170° C. In order to fully promote the crosslinking reaction of the crosslinking agent and the adhesive, the adhesive coating liquid can be heated at 40 to 80° C. for about 5 to 300 hours after the drying of the adhesive coating liquid is completed.

[0215] The base layer 10 and the adhesive resin layer (B) may be formed by co-extrusion molding, or may be formed by laminating (stacking) a film-like base layer 10 and a film-like adhesive resin layer (B).

[0216] <Other floors>

[0217] In the adhesive film 50 involved in this embodiment, within the range that does not impair the effect of this embodiment, for example, a bump absorption layer, an impact absorption layer, an easy-adhesion layer, etc. can be further provided between the substrate layer 10 and the adhesive resin layer (A) or between the substrate layer 10 and the adhesive resin layer (B).

[0218] The unevenness absorbing layer is preferably formed of natural rubber, synthetic rubber, or synthetic resin having rubber elasticity, whose Shore D hardness obtained by a Shore D hardness meter of ASTM D-2240 is, for example, 50 or less, preferably 40 or less. The thickness of the unevenness absorbing layer is, for example, 500 μm or less, preferably 5 to 300 μm, and more preferably 10 to 150 μm.

[0219] As synthetic rubber or synthetic resin, for example, synthetic rubber of nitrile, diene, acrylic, etc., thermoplastic elastomer of polyolefin, polyester, etc., ethylene-vinyl acetate copolymer, polyurethane, polybutadiene, soft polyvinyl chloride, etc., synthetic resin with rubber elasticity can be cited. In addition, even if it is a hard polymer such as polyvinyl chloride, a material that is given rubber elasticity by combining with a compounding agent such as a plasticizer and a softener can also be used in this embodiment. In addition, the adhesive resins exemplified by the above-mentioned adhesive resin layer (A) and the adhesive resin layer (B) can also be preferably used for the formation of the concave-convex absorption layer.

[0220] As mentioned above, although embodiment of this invention was described, these are illustrations of this invention, and various structures other than the above-mentioned can also be adopted.

[0221] In addition, the present invention is not limited to the above-mentioned embodiment, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are also included in the present invention.

[0222] Example

[0223] Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

[0224] The details of the materials used for producing the adhesive film are as follows.

[0225] <Adhesive resin solution SA1>

[0226] In deionized pure water, 0.5 parts by mass of 4,4'-azobis-4-cyanovaleric acid (manufactured by Otsuka Chemical Co., Ltd., trade name: ACVA) as a polymerization initiator, 74.3 parts by mass of n-butyl acrylate and 13.7 parts by mass of methyl methacrylate as monomers (a1), 9 parts by mass of 2-hydroxyethyl methacrylate as monomers (a2), and 3 parts by mass of a substance having a polymerizable 1-propenyl group introduced into the benzene ring of an ammonium salt of a sulfate ester of polyoxyethylene nonylphenyl ether (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-1025) as a polymerizable surfactant were added, and emulsion polymerization was carried out at 70 to 72° C. for 8 hours under stirring to obtain an acrylic resin emulsion. This was neutralized with aqueous ammonia (pH=7.0) to obtain an adhesive resin solution SA1 having a solid content concentration of 42.5%.

[0227] <Adhesive resin solution SA2>

[0228] In deionized pure water, 0.5 parts by mass of ammonium persulfate as a polymerization initiator, 63 parts by mass of 2-ethylhexyl acrylate, 21 parts by mass of n-butyl acrylate and 9 parts by mass of methyl methacrylate as monomers (a1), 3 parts by mass of 2-hydroxyethyl methacrylate as monomers (a2), 1 part by mass of polytetramethylene glycol diacrylate (manufactured by NOF Corporation, trade name: ADT-250) as monomers (a3), and 2 parts by mass of a substance in which a polymerizable 1-propenyl group is introduced into the benzene ring of an ammonium salt of a sulfate ester of polyoxyethylene nonylphenyl ether (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-1025) as a polymerizable surfactant were added, and emulsion polymerization was carried out at 70 to 72° C. for 8 hours under stirring to obtain an acrylic resin emulsion. This was neutralized with aqueous ammonia (pH=7.0) to obtain an adhesive resin solution SA2 having a solid content concentration of 56.5%.

[0229] <Adhesive coating liquid A1>

[0230] 57.4 parts by mass of the adhesive resin solution SA1, 42.6 parts by mass of the adhesive resin solution SA2, 0.4 parts by mass of dimethylethanolamine, and 3.4 parts by mass of an epoxy compound (Ex-1610 manufactured by Nagase Chemtex Co., Ltd.) as a crosslinking agent were mixed to obtain an adhesive coating liquid A1.

[0231] <Adhesive resin solution SB1>

[0232] In a mixed solvent containing ethyl acetate and toluene, 0.536 parts by weight of tert-butyl peroxy-2-ethylhexanoate (manufactured by NOF Corporation, trade name: Perbutyl O (registered trademark)) as a polymerization initiator, 34.9 parts by weight of 2-ethylhexyl acrylate, 41 parts by weight of n-butyl acrylate and 14.7 parts by weight of ethyl acrylate as monomers (b1), and 9.4 parts by weight of 2-hydroxyethyl methacrylate as monomers (b2) were added, and solution polymerization was carried out at 83 to 87° C. for 11 hours under stirring to obtain an acrylic resin solution having a solid content concentration of 45% by weight. This was referred to as adhesive resin solution SB1.

[0233] <Adhesive coating liquid B1>

[0234] 100 parts by mass of adhesive resin solution SB1 and 0.9 parts by mass of isocyanate crosslinking agent (Mitsui Chemicals, Inc., trade name: Olester P49-75S) (2 parts by mass relative to 100 parts by mass of adhesive resin) were mixed separately, and the solid content concentration was adjusted to 40% with ethyl acetate to obtain an adhesive coating liquid B1.

[0235] <Adhesive coating liquid B2>

[0236] 100 parts by mass of adhesive resin solution SB1, 2.25 parts by mass of polymerized rosin ester tackifier (manufactured by Arakawa Chemical Industries, Ltd., trade name: Pencel D-125) (5 parts by mass relative to 100 parts by mass of adhesive resin), 1.2 parts by mass of isocyanate crosslinking agent (manufactured by Mitsui Chemicals, Ltd., trade name: Olester P49-75S) (2 parts by mass relative to 100 parts by mass of adhesive resin), and 6.75 parts by mass of heat-expandable microspheres (manufactured by Sekisui Chemical Industries, Ltd., trade name: Advancell EM-503) (15 parts by mass relative to 100 parts by mass of adhesive resin) were mixed separately, and the solid content concentration was adjusted to 30% with ethyl acetate to prepare an adhesive coating liquid B2.

[0237] [Example 1]

[0238] On a polyethylene terephthalate (PET) film (38 μm thick) as a substrate layer, an adhesive coating liquid A1 was applied and dried to form an adhesive resin layer (A) having a thickness of 10 μm. Next, an adhesive coating liquid B1 was applied to the surface of the PET film on the opposite side to the adhesive resin layer (A) and dried to form a 20 μm thick concave-convex absorption layer, and an adhesive coating liquid B2 was applied thereon and dried to form a heat-peelable adhesive resin layer (B) having a thickness of 30 μm, thereby obtaining an adhesive film.

[0239] The adhesive resin layer (B) side of the obtained adhesive film is bonded to a 320 mm square SUS substrate, and 5 mm square semiconductor chips are placed on the adhesive resin layer (A) of the adhesive film in a grid pattern with 2 mm intervals as electronic components and made to fit tightly. Subsequently, heat treatment is performed at 130°C for 30 minutes to stabilize the adhesion between the adhesive resin layer (A) and the adhesive resin layer (B), thereby obtaining a structure.

[0240] Two days after the structure was obtained, the obtained structure was heat-treated at 100° C. for 20 minutes to reduce the moisture content in the structure.

[0241] Ten minutes after the structure was heated, a granular epoxy resin sealant (manufactured by Sumitomo Bakelite Co., Ltd., product name: G730) was used to seal the plurality of semiconductor chips on the adhesive resin layer (A) by compression molding at 135°C using a compression molding machine.

[0242] Next, the semiconductor chip was visually observed for positional displacement. As a result, no positional displacement of the semiconductor chip was observed.

[0243] [Comparative Example 1]

[0244] The positional misalignment of the semiconductor chip was observed in the same manner as in Example 1 except that the step of heating the structure at 100° C. for 20 minutes to reduce the moisture content in the structure was not performed.

[0245] As a result, a place where the semiconductor chip jumped was observed. That is, in Comparative Example 1, a positional deviation of the semiconductor chip was observed.

[0246] This application claims the priority based on Japanese patent application No. 2018-066900 filed on March 30, 2018, and all the disclosed contents are incorporated into this application.

Claims

1. A method for manufacturing an electronic device, comprising at least the following steps: Step (1), preparing a structure comprising an adhesive film, an electronic component and a supporting substrate, The adhesive film comprises: a base layer, an adhesive resin layer A provided on a first surface side of the base layer and used for temporarily fixing electronic components, and an adhesive resin layer B provided on a second surface side of the base layer and having adhesive force reduced by external stimulation, The electronic component is attached to the adhesive resin layer A of the adhesive film. The supporting substrate is adhered to the adhesive resin layer B of the adhesive film; Step (2-2), reducing the amount of water in the structure; and Step (3), sealing the electronic component with a sealing material, The step (2-2) is performed between the step (1) and the step (3).

2. The method for manufacturing an electronic device according to claim 1, In the step (2-2), the water content in the structure is reduced by heating the structure and / or reducing the pressure of the structure.

3. The method for manufacturing an electronic device according to claim 1, The step (2-2) is performed immediately before the step (3).

4. A method for manufacturing an electronic device, comprising at least the following steps: Step (1), preparing a structure comprising an adhesive film, an electronic component and a supporting substrate, The adhesive film comprises: a base layer, an adhesive resin layer A provided on a first surface side of the base layer and used for temporarily fixing electronic components, and an adhesive resin layer B provided on a second surface side of the base layer and having adhesive force reduced by external stimulation, The electronic component is attached to the adhesive resin layer A of the adhesive film. The supporting substrate is adhered to the adhesive resin layer B of the adhesive film; Step (2), at least one selected from the group consisting of step (2-1) of reducing the moisture content in the adhesive film and step (2-2) of reducing the moisture content in the structure; and Step (3), sealing the electronic component with a sealing material, The interval between the step (2) and the step (3) is within 12 hours.

5. The method for manufacturing an electronic device according to any one of claims 1 to 4, After the step (3), the method further comprises the step (4) of reducing the adhesive force of the adhesive resin layer B by applying an external stimulus, thereby peeling the supporting substrate from the structure.

6. The method for manufacturing an electronic device according to claim 5, After the step (4), the method further comprises the step (5) of peeling the adhesive film from the electronic component.

7. The method for manufacturing an electronic device according to any one of claims 1 to 4, The sealing material is an epoxy resin sealing material.

8. The method for manufacturing an electronic device according to any one of claims 1 to 4, The adhesive resin layer A contains a (meth)acrylic adhesive resin.

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