Method for manufacturing electronic device

Abstract

This method for manufacturing an electronic device is provided with at least: a preparation step for preparing a structure (100) provided with an adhesive film (50), an electronic component (70), and a support substrate (80); a pre-baking step for heating the structure (100); and a sealing step for sealing the electronic component (70) with a sealing material (60). The adhesive film (50) is provided with: a base material layer (10); an adhesive resin layer (A) that is provided on the first surface (10A) side of the base material layer (10) and that temporarily fixes the electronic component (70); and an adhesive resin layer (B) which is provided on the second surface (10B) side of the base material layer (10) and which has an adhesive force reduced by an external stimulus, the electronic component (70) being adhered to the adhesive resin layer (A) of the adhesive film (50), and the support substrate (80) being adhered to the adhesive resin layer (B) of the adhesive film (50).

Description

[0001] This application is a divisional application of the Chinese patent application No. 202080020955.7 with the title of "Manufacturing method of electronic device", filed on February 27, 2020, which is based on and claims priority from an earlier filed application. TECHNICAL FIELD

[0002] The present application relates to a manufacturing method of electronic device. BACKGROUND

[0003] As a technology capable of pursuing miniaturization and weight reduction of electronic devices (for example, semiconductor devices), a fan-out WLP (Wafer Level Package) has been developed.

[0004] In the eWLB (Embedded Wafer Level Ball Grid Array) which is one of the manufacturing methods of the fan-out WLP, a method in which a plurality of electronic components such as semiconductor chips are temporarily fixed in a separated state on an adhesive film attached to a support substrate, and the plurality of electronic components are sealed together with a sealing material is adopted. Here, the adhesive film needs to be adhered to the electronic components and the support substrate in a sealing process or the like, and needs to be removed together with the support substrate from the sealed electronic components after sealing.

[0005] As a technology related to the manufacturing method of such a fan-out WLP, for example, the technology described in Patent Literature 1 (Japanese Patent Application Publication No. 2011-134811) can be cited.

[0006] Patent Literature 1 describes a heat-resistant adhesive sheet for semiconductor device manufacturing, characterized in that it is a heat-resistant adhesive sheet for semiconductor device manufacturing to be used by being attached when a substrateless semiconductor chip is resin-sealed, and has a base material layer and an adhesive layer, the adhesive layer being a layer in which the adhesion to SUS304 after attachment is 0.5 N / 20 mm or more, and is cured by stimuli received until the resin-sealing process ends, so that the peeling force from the package becomes 2.0 N / 20 mm or less.

[0007] Prior Art Documents

[0008] Patent Literature

[0009] Patent Literature 1: Japanese Patent Application Publication No. 2011-134811 SUMMARY

[0010] Problems to be Solved by the Invention

[0011] According to the research by the present inventors, it was confirmed that when an electronic component is arranged on an adhesive film and the electronic component is sealed by a sealing material, the position of the electronic component is sometimes shifted (hereinafter, also referred to as position shift of the electronic component).

[0012] The present application has been made in view of the above circumstances, and provides a method for manufacturing an electronic device capable of suppressing position shift of an electronic component in a sealing step.

[0013] Means for solving the problem

[0014] The present inventors have made intensive studies in order to solve the above problem. As a result, it was found that by performing a pre-baking step before a sealing step, position shift of an electronic component in the sealing step can be suppressed, and thus the present application has been completed.

[0015] According to the present application, a method for manufacturing an electronic device as shown below is provided. [1]

[0017] A method for manufacturing an electronic device, comprising at least the following steps:

[0018] a preparation step of preparing a structure body provided with an adhesive film, an electronic component, and a support substrate;

[0019] a pre-baking step of heating the structure body; and

[0020] a sealing step of sealing the electronic component by a sealing material,

[0021] the adhesive film is provided with: a base material layer; an adhesive resin layer (A) provided on a first surface side of the base material layer and used for temporarily fixing the electronic component; and an adhesive resin layer (B) provided on a second surface side of the base material layer and having adhesive force reduced by external stimulation,

[0022] the electronic component is attached to the adhesive resin layer (A) of the adhesive film,

[0023] the support substrate is attached to the adhesive resin layer (B) of the adhesive film. [2]

[0025] The method for manufacturing an electronic device according to the above [1], wherein the heating temperature in the pre-baking step is less than 160°C. [3]

[0027] The method for manufacturing an electronic device according to the above [1] or [2], wherein the heating temperature in the pre-baking step is 70°C or higher. [4]

[0029] The manufacturing method of an electronic device according to any one of the above [1] to [3], further includes a first peeling step of peeling the support substrate from the structure by reducing the adhesion of the adhesive resin layer (B) by applying an external stimulus after the sealing step. [5]

[0031] The manufacturing method of an electronic device according to the above [4], further includes a second peeling step of peeling the adhesive film from the electronic component after the first peeling step. [6]

[0033] The manufacturing method of an electronic device according to any one of the above [1] to [5], wherein the sealing material is an epoxy resin-based sealing material. [7]

[0035] The manufacturing method of an electronic device according to any one of the above [1] to [6], wherein the adhesive resin constituting the adhesive resin layer (A) includes one or two or more selected from the group consisting of a (meth)acrylic-based adhesive resin, a silicone-based adhesive resin, a urethane-based adhesive resin, an olefin-based adhesive resin, and a styrene-based adhesive resin.

[0036] Effects of the Invention

[0037] According to the present application, it is possible to provide a manufacturing method of an electronic device capable of suppressing positional displacement of an electronic component in a sealing step. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 A cross-sectional view schematically showing an example of a structure of an adhesive film of an embodiment to which the present application is applied.

[0039] Figure 2 A cross-sectional view schematically showing an example of a manufacturing method of an electronic device of an embodiment to which the present application is applied.

[0040] Figure 3 A cross-sectional view schematically showing an example of a manufacturing method of an electronic device of an embodiment to which the present application is applied. DETAILED DESCRIPTION

[0041] Hereinafter, with respect to the embodiments of the present application, explanation is made using the drawings. Also, in all the drawings, with respect to the same constituent elements, common symbols are attached, and explanation is appropriately omitted. Further, the drawings are schematic views, and do not coincide with the actual dimensional ratio. Furthermore, with respect to a numerical range "A to B", unless otherwise specified, it means A or more and B or less. Furthermore, in the present embodiment, the term "(meth)acrylic acid" means acrylic acid, methacrylic acid, or both of acrylic acid and methacrylic acid.

[0042] 1. A manufacturing method of an electronic device

[0043] First, a manufacturing method of an electronic device according to the present embodiment will be described. Figure 1 A cross-sectional view schematically showing an example of a structure of an adhesive film 50 according to the present embodiment will be described.

[0044] Figure 2 and Figure 3 A cross-sectional view schematically showing an example of a manufacturing method of an electronic device according to the present embodiment will be described.

[0045] The manufacturing method of an electronic device according to the present embodiment has at least the following three steps.

[0046] (1) A preparation step of preparing a structure 100 having an adhesive film 50, an electronic component 70, and a support substrate 80, the adhesive film 50 having: 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 a reduced adhesive force by an external stimulus, the electronic component 70 being attached to the adhesive resin layer (A) of the adhesive film 50, and the support substrate 80 being attached to the adhesive resin layer (B) of the adhesive film 50,

[0047] (2) A pre-baking step of heating the structure 100,

[0048] (3) A sealing step of sealing the electronic component 70 with a sealing material 60.

[0049] As described above, according to the research by the present inventors and others, it has been clarified that when an electronic component is disposed on an adhesive film and the electronic component is sealed with a sealing material, the position of the electronic component sometimes shifts (hereinafter, also referred to as position shift of the electronic component).

[0050] The present inventors and others have repeatedly and intensively researched in order to solve the above problem. As a result, it has been recognized that in a step of sealing the electronic component, the position of the electronic component shifts due to the pressure caused by the flow of the sealing material, and further, the position of the electronic component shifts due to outgassing derived from the moisture contained in the adhesive film, particularly, outgassing derived from the moisture contained in the adhesive resin layer attached to the support substrate side.

[0051] The present inventors and others have repeatedly researched further based on the above recognition. As a result, it has been found for the first time that by performing a pre-baking step of heating the structure 100 before the sealing step, the adhesive force of the adhesive resin layer (A) with respect to the electronic component 70 is increased, and the position shift of the electronic component in the sealing step is suppressed.

[0052] That is, according to the manufacturing method of an electronic device related to the present embodiment, since the pre-baking process of heating the structure 100 is performed before the sealing process, the adhesion of the adhesive resin layer (A) to the electronic component 70 is improved, and thus it is possible to suppress the positional displacement of the electronic component 70 due to the pressure caused by the flow of the sealing material 60 and the outgassing due to moisture in the process of sealing the electronic component.

[0053] As described above, according to the manufacturing method of an electronic device related to the present embodiment, it is possible to suppress the positional displacement of the electronic component in the sealing process.

[0054] Hereinafter, each process of the manufacturing method of an electronic device related to the present embodiment will be described.

[0055] ((1) Preparation process)

[0056] In the preparation process, a structure 100 is prepared, which includes an adhesive film 50, an electronic component 70 adhered to the adhesive resin layer (A) of the adhesive film 50, and a support substrate 80 adhered to the adhesive resin layer (B) of the adhesive film 50.

[0057] Such a structure 100 can be manufactured, for example, by the following steps.

[0058] First, the adhesive film 50 is attached to the support substrate 80 so that the adhesive resin layer (B) is on the support substrate 80 side. A protective film called a spacer can be adhered 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.

[0059] As the support substrate 80, for example, a quartz substrate, a glass substrate, a SUS substrate, or the like can be used.

[0060] Next, the electronic component 70 is disposed on the adhesive resin layer (A) of the adhesive film 50 attached to the support substrate 80, and thus the structure 100 can be obtained.

[0061] As the electronic component 70, for example, a semiconductor chip such as an IC, an LSI, a discrete, a light emitting diode, a light receiving element, a semiconductor panel, a semiconductor package, or the like can be used.

[0062] ((2) Pre-baking process)

[0063] In the pre-baking step, the structure 100 obtained in the preparation step is heated. By so doing, the adhesion of the adhesive resin layer (A) to the electronic component 70 in the adhesive film 50 can be improved. As a result, in the sealing step, when the electronic component 70 is sealed by the sealing material 60, the positional displacement of the electronic component 70 due to the pressure caused by the flow of the sealing material 60 and the outgassing from moisture can be suppressed.

[0064] In the pre-baking step, as the upper limit of the temperature at the time of heating the structure 100, there is no particular limitation as long as it is a temperature at which the adhesion of the adhesive resin layer (A) to the electronic component 70 can be improved, and it is preferably less than 160°C, more preferably 155°C or lower, and further preferably 150°C or lower. By so doing, the outgassing from moisture contained in the adhesive film can be suppressed from being generated abruptly, and as a result, in the pre-baking step and the sealing step, the positional displacement of the electronic component 70 due to the outgassing from moisture can be further suppressed. In addition, in the case where the adhesive resin layer (B) is of the heat-expandable type, if the temperature at the time of heating the structure 100 is less than or equal to the above upper limit, the thermal expansion is suppressed, and thus the decrease in the adhesion of the adhesive film 50 to the support substrate 80 is suppressed, and as a result, the peeling of the adhesive film 50 from the support substrate 80 in the step of sealing the electronic component can be suppressed.

[0065] In the pre-baking step, as the lower limit of the temperature at the time of heating the structure 100, there is no particular limitation as long as it is a temperature at which the adhesion of the adhesive resin layer (A) to the electronic component 70 can be improved, and it is preferably 70°C or higher, more preferably 80°C or higher, further preferably 90°C or higher, and further more preferably 100°C or higher. By so doing, the heating time in the pre-baking step can be shortened, and as a result, the manufacturing time of the electronic device can be shortened. If the manufacturing time of the electronic device can be shortened, the productivity of the electronic device can be improved.

[0066] The time for which the structure 100 is heated is not particularly limited as long as it is a heating time at which the adhesion of the adhesive resin layer (A) to the electronic component 70 can be improved, and for example, it is preferably in the range of 1 minute or more and 120 minutes or less, and more preferably 5 minutes or more and 80 minutes or less.

[0067] The method for heating the structure 100 is not particularly limited, and for example, a generally known heating treatment method such as an oven, a dryer, a heating roller, a drying furnace, or the like can be used.

[0068] As to whether the adhesion of the adhesive resin layer (A) to the electronic component 70 is improved or not, for example, a generally known method such as the share strength of the electronic component 70 and the adhesive film 50 can be used.

[0069] ((3) Sealing step)

[0070] Next, the electronic component 70 is sealed by the sealing material 60.

[0071] The electronic component 70 is sealed by covering the electronic component 70 with the sealing material 60, and curing the sealing material 60 at a temperature of 150°C or lower, for example.

[0072] Further, the sealing material 60 is not particularly limited in form, and is, for example, in a granular form, a sheet form, or a liquid form.

[0073] The sealing material 60 is not particularly limited, and is, for example, an epoxy resin-based sealing material using an epoxy resin.

[0074] From the viewpoint of making the affinity of the sealing material 60 for the adhesive film 50 better, and enabling the electronic component 70 to be more uniformly sealed, an epoxy resin-based sealing material in a liquid form is particularly preferable.

[0075] As such an epoxy resin-based sealing material, for example, T693 / R4000 series, T693 / R1000 series, T693 / R5000 series, and the like manufactured by Nagase Chemtex Corporation can be used.

[0076] As the sealing method, for example, transfer molding, injection molding, compression molding, casting molding, and the like can be given. After the electronic component 70 is sealed by the sealing material 60, the sealing material 60 can be cured, for example, by heating at a temperature of 150°C or lower, thereby obtaining a structure 100 in which the electronic component 70 is sealed.

[0077] ((4) First peeling step)

[0078] In the method for manufacturing an electronic device according to the present embodiment, as shown in Figure 3 ((3) Sealing step), a first peeling step of reducing the adhesion of the adhesive resin layer (B) to peel off the support substrate 80 from the structure 100 by imparting an external stimulus can be further included.

[0079] The support substrate 80 can be easily removed from the adhesive film 50, for example, by heating to a temperature exceeding 150°C after the electronic component 70 is sealed, to reduce the adhesion of the adhesive resin layer (B).

[0080] ((5) Second peeling step)

[0081] In the method for manufacturing an electronic device according to the present embodiment, as shown in Figure 3As shown, after the first peeling process, the second peeling process of peeling the adhesive film 50 from the electronic component 70 is further provided to obtain the electronic device 200.

[0082] As the method of peeling the adhesive film 50 from the electronic component 70, for example, a method of mechanically peeling, a method of peeling after reducing the adhesion of the surface of the adhesive film 50, and the like can be given.

[0083] (Other processes)

[0084] In the method of manufacturing the electronic device according to the present embodiment, as shown, a process (6) of forming a wiring layer 310 and a bump 320 on the exposed surface of the obtained electronic device 200 to obtain an electronic device 300 can be further provided. Figure 3

[0085] The wiring layer 310 includes a pad (not shown) as an external connection terminal formed on the outermost surface, and a wiring (not shown) electrically connecting the exposed electronic component 70 and the pad. The wiring layer 310 can be formed by a publicly known method, and can be a multilayer structure.

[0086] Further, the bump 320 can be formed on the pad of the wiring layer 310 to obtain the electronic device 300. As the bump 320, a solder bump, a gold bump, and the like can be given. The solder bump can be formed by, for example, arranging a solder ball on the pad as the external connection terminal of the wiring layer 310 and melting (reflowing) the solder by heating. The gold bump can be formed by a ball bonding method, a plating method, an Au ball transfer printing method, and the like.

[0087] In the method of manufacturing the electronic device according to the present embodiment, as shown, a process (7) of cutting the electronic device 300 to obtain a plurality of electronic devices 400 can be further provided. Figure 3

[0088] The cutting of the electronic device 300 can be performed by a publicly known method.

[0089] 2. Adhesive film

[0090] Hereinafter, the adhesive film 50 according to the present embodiment will be described.

[0091] Figure 1 A cross-sectional view schematically showing an example of the structure of the adhesive film 50 according to the present embodiment.

[0092] As shown, the adhesive film 50 according to the present embodiment includes a base film 51, a first adhesive layer 52, a second adhesive layer 53, and a third adhesive layer 54. Figure 1 ​​As illustrated, the adhesive film 50 according to the present embodiment includes a substrate layer 10, an adhesive resin layer (A) provided on the first surface 10A side of the substrate layer 10, and an adhesive resin layer (B) provided on the second surface 10B side of the substrate layer 10 and having a reduced adhesive force by an external stimulus.

[0093] The thickness of the adhesive film 50 according to the present embodiment is preferably 10 μm or more and 1000 μm or less, and more preferably 20 μm or more and 500 μm or less, from the viewpoint of balancing mechanical properties and handling properties.

[0094] Next, each layer constituting the adhesive film 50 according to the present embodiment will be described.

[0095] <Substrate Layer>

[0096] The substrate layer 10 is a layer provided for the purpose of improving the handling properties, mechanical properties, heat resistance, and the like of the adhesive film 50.

[0097] The substrate layer 10 is not particularly limited, and examples thereof include a resin film.

[0098] As the resin constituting the resin film, a publicly known thermoplastic resin can be used. Examples thereof include one or two or more selected from the group consisting of polyolefins such as polyethylene, polypropylene, poly(4-methyl-1-pentene), and poly(1-butene); polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyamides such as nylon-6, nylon-66, and poly-m-xylylene adipamide; polyacrylates; polymethacrylates; polyvinyl chloride; polyvinylidene chloride; polyimides; polyetherimides; ethylene-vinyl acetate copolymers; polyacrylonitrile; polycarbonates; polystyrene; ionomers; polysulfones; polyethersulfones; and polyphenylene ethers.

[0099] Among these, from the viewpoint of balancing transparency, mechanical strength, and price, one or two or more selected from the group consisting of polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyamides, and polyimides is preferred, and at least one selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate is more preferred.

[0100] The substrate layer 10 can be a single layer, or two or more layers.

[0101] Further, as the form of the resin film used to form the substrate layer 10, it can be a stretched film, or a film stretched in a uniaxial direction or a biaxial direction, and from the viewpoint of improving the mechanical strength of the substrate layer 10, a film stretched in a uniaxial direction or a biaxial direction is preferred.

[0102] The thickness of the base layer 10 is preferably 1 μm or more and 500 μm or less, more preferably 5 μm or more and 300 μm or less, and further preferably 10 μm or more and 250 μm or less, from the viewpoint of obtaining good film properties.

[0103] The base layer 10 can be subjected to surface treatment in order to improve adhesion to other layers. Specifically, it can be subjected to corona treatment, plasma treatment, under coat treatment, primer coat treatment, or the like.

[0104] <Adhesive resin layer (A)>

[0105] The adhesive resin layer (A) is a layer provided on one side of the base layer 10, and is, for example, a layer used for contacting the surface of an electronic component and temporarily fixing the electronic component when the electronic component is sealed by a sealing material in a manufacturing process of an electronic device.

[0106] The adhesive resin layer (A) contains an adhesive resin (A1).

[0107] As the adhesive resin (A1), for example, a (meth)acrylic adhesive resin (a), a silicone adhesive resin, a urethane adhesive resin, an olefin adhesive resin, a styrene adhesive resin, or the like can be given.

[0108] Among these, from the viewpoint of making adjustment of adhesion force easy and the like, the (meth)acrylic adhesive resin (a) is preferable.

[0109] As the adhesive resin layer (A), a radiation crosslinking type adhesive resin layer in which adhesion force is reduced by radiation can also be used. The radiation crosslinking type adhesive resin layer is crosslinked by irradiation of radiation, and the adhesion force is significantly reduced, and thus the adhesive film 50 is easily peeled from the electronic component. As the radiation, ultraviolet rays, electron rays, infrared rays, or the like can be given.

[0110] As the radiation crosslinking type adhesive resin layer, an ultraviolet crosslinking type adhesive resin layer is preferable.

[0111] As the (meth)acrylic adhesive resin (a) used for the adhesive resin layer (A), for example, a copolymer containing a (meth)acrylic alkyl ester monomer unit (a1) and a monomer unit (a2) having a functional group capable of reacting with a crosslinking agent can be given.

[0112] In the present embodiment, the (meth)acrylic alkyl ester means an alkyl acrylate, an alkyl methacrylate, or a mixture thereof.

[0113] The (meth)acrylic adhesive resin (a) according to the present embodiment can be obtained, for example, by copolymerizing a monomer mixture containing an alkyl (meth)acrylate monomer (al) and a monomer (a2) having a functional group capable of reacting with a crosslinking agent.

[0114] As the monomer (al) forming the alkyl (meth)acrylate monomer unit (al), an alkyl (meth)acrylate having an alkyl group having a carbon number of about 1 to 12 can be given. An alkyl (meth)acrylate having an alkyl group having a carbon number of 1 to 8 is preferable. Specifically, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and the like can be given. Two or more of them can be used alone or in combination.

[0115] 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% by mass, the content of the alkyl (meth)acrylate monomer unit (al) 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 further preferably 85% by mass or more and 95% by mass or less.

[0116] 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 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, t-butylaminoethyl acrylate, t-butylaminoethyl methacrylate, and the like can be given. Acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, and the like are preferable. Two or more of them can be used alone or in combination.

[0117] 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% by mass, 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 further preferably 1% by mass or more and 10% by mass or less.

[0118] The (meth)acrylic adhesive resin (a) according to the present embodiment can further contain, in addition to the monomer unit (al) and the monomer unit (a2), a 2-functional monomer unit (a3) and a specific comonomer unit having the property of a surfactant (hereinafter referred to as a polymerizable surfactant).

[0119] The polymerizable surfactant has the property of being copolymerized with the monomer (al), the monomer (a2), and the monomer (a3), and has the effect of an emulsifier in the case of emulsion polymerization.

[0120] As the monomer (a3) forming the 2-functional monomer unit (a3), mention can be made of 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, a substance in which both terminals are diacrylate or dimethacrylate and the structure of the main chain is propylene glycol type (for example, manufactured by Nippon Oil & Fats Co., Ltd., trade name: PDP-200, manufactured by Nippon Oil & Fats Co., Ltd. PDP-400, manufactured by Nippon Oil & Fats Co., Ltd. ADP-200, manufactured by Nippon Oil & Fats Co., Ltd. ADP-400), 1,4-butanediol type (for example, manufactured by Nippon Oil & Fats Co., Ltd., trade name: ADT-250, manufactured by Nippon Oil & Fats Co., Ltd. ADT-850), and a mixed type thereof (for example, manufactured by Nippon Oil & Fats Co., Ltd., trade name: ADET-1800, manufactured by Nippon Oil & Fats Co., Ltd. ADPT-4000), and the like.

[0121] In the (meth)acrylic adhesive resin (a) according to the present embodiment, when the total of all the monomer units in the (meth)acrylic adhesive resin (a) is taken as 100 mass%, the content of the monomer unit (a3) is preferably 0.1 mass% or more and 30 mass% or less, more preferably 0.1 mass% or more and 15 mass% or less, further preferably 0.1 mass% or more and 20 mass% or less, and particularly preferably 0.1 mass% or more and 5 mass% or less.

[0122] As examples of the polymerizable surfactant, there are, for example, a surfactant in which a polymerizable 1-propenyl group is introduced into a benzene ring of polyoxyethylene nonylphenyl ether (manufactured by the First Industrial Co., Ltd.; trade name: Aquaon RN-10, Aquaon RN-20, Aquaon RN-30, Aquaon RN-50, etc.), a surfactant in which a polymerizable 1-propenyl group is introduced into a benzene ring of an ammonium salt of a sulfate ester of polyoxyethylene nonylphenyl ether (manufactured by the First Industrial Co., Ltd.; trade name: Aquaon HS-10, Aquaon HS-20, Aquaon HS-1025, etc.), and a sulfosuccinic acid diester-based surfactant having a polymerizable double bond in the molecule (manufactured by the Kao Corporation; trade name: Latemul S-120A, Latemul S-180A, etc.), and the like.

[0123] 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% by mass, 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 15% by mass or less, further preferably 0.1% by mass or more and 20% by mass or less, and particularly preferably 0.1% by mass or more and 5% by mass or less.

[0124] The (meth)acrylic adhesive resin (a) according to the present embodiment can further contain, as needed, a monomer unit formed from a monomer having a polymerizable double bond such as vinyl acetate, acrylonitrile, or styrene.

[0125] As the polymerization mechanism of the (meth)acrylic adhesive resin (a) according to the present embodiment, there are, for example, radical polymerization, anionic polymerization, cationic polymerization, and the like. If the manufacturing cost of the (meth)acrylic adhesive resin (a), the influence of the functional group of the monomer, and the influence of ions on the surface of the electronic component are taken into consideration, it is preferable that the polymerization be performed by radical polymerization.

[0126] When polymerization is performed by a radical polymerization reaction, as the radical polymerization initiator, mention can be made 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-butyl peroxy-2-hexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, t-butyl peroxide, di-t-amyl peroxide, and the like organic peroxides; ammonium persulfate, potassium persulfate, sodium persulfate, and the like inorganic peroxides; 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 4,4'-azobis-4-cyanovaleric acid, and the like azo compounds.

[0127] In the case where polymerization is performed by an emulsion polymerization method, among these radical polymerization initiators, inorganic peroxides such as ammonium persulfate, potassium persulfate, and sodium persulfate, which are water-soluble, and azo compounds such as 4,4'-azobis-4-cyanovaleric acid, which have a carboxyl group within the molecule and are water-soluble, are preferred. If the influence of ions on the surface of an electronic component is taken into consideration, azo compounds such as 4,4'-azobis-4-cyanovaleric acid, which have a carboxyl group within the molecule, are further preferred, and azo compounds such as 4,4'-azobis-4-cyanovaleric acid, which have a carboxyl group within the molecule, are particularly preferred.

[0128] In the adhesive resin layer (A) according to the present embodiment, in addition to the adhesive resin (Al), a crosslinking agent (A2) having two or more crosslinkable functional groups in one molecule is preferably further included.

[0129] The crosslinking agent (A2) having two or more crosslinkable functional groups in one molecule is used to react with the functional groups possessed by the adhesive resin (Al), and adjust the adhesion and cohesion.

[0130] As such a crosslinking agent (A2), epoxy-based compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, resorcinol diglycidyl ether, and the like; isocyanate-based compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylolpropane toluene diisocyanate triadduct, polyisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, and the like; aziridine-based compounds such as trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(l-aziridinylcarboxamide), N,N'-hexamethylene-l,6-bis(l-aziridinylcarboxamide), N,N'-toluene-2,4-bis(l-aziridinylcarboxamide), trimethylolpropane-tri-β-(2-methylaziridine)propionate, and the like; tetrafunctional epoxy-based compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, and the like; melamine-based compounds such as hexamethoxymethylmelamine, and the like can be given. These can be used alone or in combination of two or more.

[0131] Among these, one or two or more selected from the group consisting of epoxy-based compounds, isocyanate-based compounds, and aziridine-based compounds are preferable.

[0132] The content of the crosslinking agent (A2) is generally preferably in 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 a functional group is newly generated by the crosslinking reaction, in the case where the crosslinking reaction is slow, and the like, it can be contained in excess as necessary.

[0133] Regarding the content of the crosslinking agent (A2) in the adhesive resin layer (A), from the viewpoint of improving the balance between the heat resistance and the adhesion of the adhesive resin layer (A), it 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).

[0134] The adhesive resin layer (A) can contain additives such as plasticizers, tackifying resins, and the like as other components. In the case where the adhesive resin layer (A) is a radiation crosslinking type adhesive resin layer, various additives for radiation crosslinking can be contained. When the entirety of the adhesive resin layer (A) is taken as 100% by mass, the total of the contents 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, further preferably 90% by mass or more, and particularly preferably 95% by mass or more. Thereby, the occurrence of the adhesive residue on the electronic component side at the time of peeling the adhesive film from the electronic component can be further suppressed.

[0135] The thickness of the adhesive resin layer (A) is not particularly limited, and for example, is preferably 1 μm or more and 100 μm or less, and more preferably 3 μm or more and 50 μm or less.

[0136] The adhesive resin layer (A) can be formed, for example, by applying an adhesive on the base material layer 10. The adhesive can be applied as a coating liquid by dissolving in a solvent, can be applied as an aqueous emulsion, or can be directly applied as a liquid adhesive.

[0137] Among them, an adhesive coating liquid dissolved in an organic solvent is preferable. The organic solvent is not particularly limited, and can be appropriately selected from publicly known organic solvents in terms of solubility and drying time. As the organic solvent, ester-based solvents such as ethyl acetate and methyl acetate; ketone-based solvents such as acetone and MEK; aromatic solvents such as benzene, toluene, and ethylbenzene; and linear or cyclic aliphatic solvents such as heptane, hexane, and cyclohexane; and alcohol-based solvents such as isopropyl alcohol and butanol can be exemplified. As the organic solvent, ethyl acetate and toluene are preferable. These solvents can be used alone or in combination of two or more.

[0138] As the method of applying the adhesive coating liquid, publicly known coating methods such as a roll coater method, a reverse roll coater method, a gravure roll method, a bar coater method, a hopper coater method, and a die coater method can be used. The drying conditions of the applied adhesive are not particularly limited, and in general, drying is preferably performed at a temperature of 80 to 200°C for 10 seconds to 10 minutes. Further preferably, drying is performed at 80 to 170°C for 15 seconds to 5 minutes. In order to sufficiently promote the crosslinking reaction of the crosslinking agent and the adhesive, heating at 40 to 80°C for 5 to 300 hours or so can be performed after the drying of the adhesive coating liquid is completed.

[0139] Further, the base material layer 10 and the adhesive resin layer (A) can be formed by co-extrusion molding, or can be formed by laminating (stacking) a film-shaped base material layer 10 and a film-shaped adhesive resin layer (A).

[0140] <Adhesive resin layer (B)>

[0141] The adhesive film 50 according to the present embodiment has an adhesive resin layer (B) having a reduced adhesive force by external stimulation on the second surface 10B side of the base material layer 10 opposite the first surface 10A.

[0142] Thus, by applying an external stimulus, the adhesive film 50 can be easily peeled from the support substrate 80.

[0143] Here, as the adhesive resin layer (B) whose adhesion is reduced by external stimulation, for example, a heat-peeling type adhesive resin layer whose adhesion is reduced by heating, a radiation-peeling type adhesive resin layer whose adhesion is reduced by radiation, and the like can be given. Among these, the heat-peeling type adhesive resin layer whose adhesion is reduced by heating is preferable.

[0144] As the heat-peeling type adhesive resin layer, for example, an adhesive resin layer composed of a heat-expanding type adhesive containing a gas generating component, a heat-expanding type adhesive containing heat-expandable microspheres that can reduce adhesion by expansion, a heat-expanding type adhesive in which adhesion is reduced by cross-linking reaction of an adhesive component by heat, and the like can be given.

[0145] In the present embodiment, the heat-expanding type adhesive used for the adhesive resin layer (B) is, for example, an adhesive whose adhesion is reduced or lost by heating at a temperature exceeding 150°C. For example, a material that does not peel at 150°C or lower and peels at a temperature exceeding 150°C can be selected, and preferably has adhesion to the extent that the adhesive film 50 does not peel from the support substrate 80 in the manufacturing process of the electronic device.

[0146] Here, for the case where adhesion is reduced or lost by heating at a temperature exceeding 150°C, for example, the following evaluation can be made: the adhesive resin layer (B) side is attached to a stainless steel plate, a heating treatment at 140°C for 1 hour is performed, and then the peeling strength from the stainless steel plate is measured after heating at a temperature exceeding 150°C for 2 minutes, and is evaluated by the peeling strength. The specific heating temperature at the time of heating at a temperature exceeding 150°C can be set to a temperature higher than the temperature at which gas is generated or the temperature at which heat-expandable microspheres thermally expand, and can be appropriately set depending on the kind of the generated gas or the heat-expandable microspheres. In the present embodiment, the loss of adhesion means, for example, a case where the 180° peeling strength measured at 23°C and a tensile speed of 300 mm / minute is less than 0.5 N / 25 mm.

[0147] As the gas generating component used for the heat-expandable adhesive, for example, azo compounds, azide compounds, Michler's acid derivatives, and the like can be used. In addition, inorganic blowing agents such as ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium borohydride, various azides, water; chlorofluoroalkane compounds such as trichloromonofluoromethane, dichloromonofluoromethane; azo compounds such as azobis isobutyronitrile, azodicarboxamide, barium azodicarboxylate; hydrazine compounds such as p-toluenesulfonyl hydrazide, diphenyl sulfone-3,3'-disulfonyl hydrazide, 4,4'-oxybis(benzenesulfonyl hydrazide), allyl bis(sulfonyl hydrazide); carbazate compounds such as p-methoxyphenylene sulfonyl carbazate, 4,4'-oxybis(benzenesulfonyl carbazate); triazole compounds such as 5-morpholinyl-1,2,3,4-thiatriazole; N-nitroso compounds such as N,N'-dinitrosopentamethylene tetramine, N,N'-dimethyl-N,N'-dinitrosophthaloyl diamide; and the like can be used. The gas generating component can be added to the adhesive resin (B1) or can be directly combined with the adhesive resin (B1).

[0148] As the heat-expandable microspheres used for the heat-expandable adhesive, for example, microencapsulated blowing agents can be used. As such heat-expandable microspheres, for example, microspheres in which substances that easily gasify and expand by heating, such as isobutane, propane, pentane, and the like, are enclosed in an elastic shell can be used. As the material constituting the shell, for example, 1,1-dichloroethylene-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, polysulfone, and the like can be used. The heat-expandable microspheres can be produced, for example, by a coacervation method, an interfacial polymerization method, or the like.

[0149] The heat-expandable microspheres can be added to the adhesive resin.

[0150] 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, the reducibility of the adhesive force, and the like of the heat-peeling type adhesive resin layer (B), and is not particularly limited, and for example, is 1 parts by mass or more and 150 parts by mass or less, preferably 10 parts by mass or more and 130 parts by mass or less, and further preferably 12 parts by mass or more and 100 parts by mass or less, with respect to 100 parts by mass of the adhesive resin (B1) in the heat-peeling type adhesive resin layer (B).

[0151] The temperature at which the gas is generated and the temperature at which the heat-expandable microspheres expand are preferably designed to be a temperature exceeding 150°C.

[0152] As the adhesive resin (B1) constituting the heat-expandable adhesive, for example, a (meth)acrylic resin (b), a urethane-based resin, a silicone-based resin, a polyolefin-based resin, a polyester-based resin, a polyamide-based resin, a fluorine-based resin, a styrene-diene block copolymer-based resin, and the like can be given. Among these, the (meth)acrylic resin (b) is preferred.

[0153] As the (meth)acrylic adhesive resin (b) used for the adhesive resin layer (B), for example, a copolymer containing an alkyl (meth)acrylate monomer unit (b1) and a monomer unit (b2) having a functional group capable of reacting with a crosslinking agent can be given.

[0154] In the present embodiment, the alkyl (meth)acrylate refers to an alkyl acrylate, an alkyl methacrylate, or a mixture thereof.

[0155] The (meth)acrylic adhesive resin (b) related to the present embodiment can be obtained, for example, by copolymerizing a monomer mixture containing an alkyl (meth)acrylate monomer (b1) and a monomer (b2) having a functional group capable of reacting with a crosslinking agent.

[0156] As the monomer (b1) forming the alkyl (meth)acrylate monomer unit (b1), an alkyl (meth)acrylate having an alkyl group having a carbon number of about 1 to 12 can be given. An alkyl (meth)acrylate having an alkyl group having a carbon number of 1 to 8 is preferred. Specifically, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and the like can be given. Two or more of these can be used alone or in combination.

[0157] In the (meth)acrylic adhesive resin (b) related to the present embodiment, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is taken as 100% by mass, the content of the alkyl (meth)acrylate 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 further preferably 85% by mass or more and 95% by mass or less.

[0158] As the monomer (b2) forming the monomer unit (b2) having a functional group capable of reacting with the 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, t-butylaminoethyl acrylate, t-butylaminoethyl methacrylate, and the like can be given. Acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, and the like are preferable. Two or more of them can be used alone or in combination.

[0159] 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 further preferably 1% by mass or more and 10% by mass or less, when the total of all the monomer units in the (meth)acrylic adhesive resin (b) is taken as 100% by mass.

[0160] In the (meth)acrylic adhesive resin (b) according to the present embodiment, in addition to the monomer unit (b1) and the monomer unit (b2), a 2-functional monomer unit (b3) and a specific comonomer unit having the property of a surfactant (hereinafter referred to as a polymerizable surfactant) can be further included.

[0161] The polymerizable surfactant has the property of copolymerizing with the monomer (b1), the monomer (b2), and the monomer (b3), and in the case of emulsion polymerization, has the effect of an emulsifier.

[0162] As the monomer (b3) forming the 2-functional monomer unit (b3), 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, a monomer in which both terminals are diacrylate or dimethacrylate and the structure of the main chain is propylene glycol type (for example, manufactured by Nippon Shokubai Co., Ltd., trade name: PDP-200, manufactured by Nippon Shokubai Co., Ltd. PDP-400, manufactured by Nippon Shokubai Co., Ltd. ADP-200, manufactured by Nippon Shokubai Co., Ltd. ADP-400), 1,4-butanediol type (for example, manufactured by Nippon Shokubai Co., Ltd., trade name: ADT-250, manufactured by Nippon Shokubai Co., Ltd. ADT-850), and a mixed type thereof (for example, manufactured by Nippon Shokubai Co., Ltd., trade name: ADET-1800, manufactured by Nippon Shokubai Co., Ltd. ADPT-4000), and the like can be given.

[0163] In the (meth)acrylic adhesive resin (b) according to the present embodiment, the content of the 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 15% by mass or less, further preferably 0.1% by mass or more and 20% by mass or less, and particularly 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 taken as 100% by mass.

[0164] As examples of the polymerizable surfactant, there are, for example, a surfactant in which a polymerizable 1-propenyl group is introduced into the benzene ring of polyoxyethylene nonylphenyl ether (manufactured by the First Industrial Co., Ltd.; trade name: Akucell RN-10, Akucell RN-20, Akucell RN-30, Akucell RN-50, etc.), a surfactant 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 the First Industrial Co., Ltd.; trade name: Akucell HS-10, Akucell HS-20, Akucell HS-1025, etc.), and a sulfosuccinic acid diester-based surfactant having a polymerizable double bond in the molecule (manufactured by the Kao Corporation; trade name: Latemul S-120A, Latemul S-180A, etc.), and the like.

[0165] 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 15% by mass or less, further preferably 0.1% by mass or more and 20% by mass or less, and particularly 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 taken as 100% by mass.

[0166] The (meth)acrylic adhesive resin (b) according to the present embodiment can further contain, as needed, a monomer unit formed from a monomer having a polymerizable double bond such as vinyl acetate, acrylonitrile, and styrene.

[0167] As the polymerization mechanism of the (meth)acrylic adhesive resin (b) according to the present embodiment, there are, for example, radical polymerization, anionic polymerization, cationic polymerization, and the like. If the manufacturing cost of the (meth)acrylic adhesive resin (b), the influence of the functional group of the monomer, and the influence of ions on the surface of the electronic component are taken into consideration, it is preferable to perform polymerization by radical polymerization.

[0168] When polymerization is performed by a radical polymerization reaction, as the radical polymerization initiator, mention can be made 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-butyl peroxy-2-hexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, t-butyl peroxide, di-t-amyl peroxide, and the like organic peroxides; ammonium persulfate, potassium persulfate, sodium persulfate, and the like inorganic peroxides; 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 4,4'-azobis-4-cyanovaleric acid, and the like azo compounds.

[0169] In the case where polymerization is performed by an emulsion polymerization method, among these radical polymerization initiators, inorganic peroxides such as ammonium persulfate, potassium persulfate, and sodium persulfate, and azo compounds such as 4,4'-azobis-4-cyanovaleric acid having a carboxyl group within the molecule, which are water-soluble, are preferred. If the influence of ions on the surface of an electronic component is taken into consideration, further preferred are azo compounds such as 4,4'-azobis-4-cyanovaleric acid having a carboxyl group within the molecule, and particularly preferred is 4,4'-azobis-4-cyanovaleric acid having a carboxyl group within the molecule.

[0170] 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).

[0171] The crosslinking agent (B2) having two or more crosslinkable functional groups in one molecule is used to react with the functional groups possessed by the adhesive resin (B1), and adjust the adhesion and cohesion.

[0172] As such a crosslinking agent (B2), epoxy-based compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, resorcinol diglycidyl ether, and the like; isocyanate-based compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, and the like; aziridine-based compounds such as trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(l-aziridinylcarboxamide), N,N'-hexamethylene-l,6-bis(l-aziridinylcarboxamide), N,N'-toluene-2,4-bis(l-aziridinylcarboxamide), trimethylolpropane-tri-β-(2-methylaziridine)propionate, and the like; tetrafunctional epoxy-based compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, and the like; melamine-based compounds such as hexamethoxymethylmelamine, and the like can be given. These can be used alone or in combination of two or more.

[0173] Among these, one or two or more selected from the group consisting of epoxy-based compounds, isocyanate-based compounds, and aziridine-based compounds are preferred.

[0174] The content of the crosslinking agent (B2) is generally preferably in 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 a functional group is newly generated by the crosslinking reaction, in the case where the crosslinking reaction is slow, and the like, it can be contained in excess as necessary.

[0175] 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, with respect to 100 parts by mass of the adhesive resin (B1).

[0176] From the viewpoint of improving adhesion to the support substrate, the adhesive resin layer (B) according to the present embodiment preferably contains a tackifying resin in addition to the adhesive resin (Bl). The tackifying resin is preferably contained in the adhesive resin layer (B) because it is easy to adjust the adhesion to the support substrate at around room temperature. As the tackifying resin, a tackifying resin having a softening point of 100°C or higher is preferable. As specific examples of the tackifying resin, there are mentioned rosin-based resins such as rosin-based derivatives subjected to esterification or the like; terpene-based resins such as α-pinene-based, β-pinene-based, dipentene-based, terpene phenolic-based resins; natural-based rosins such as rubber-based, wood-based, tall oil-based rosins; petroleum resins subjected to hydrogenation, disproportionation, polymerization, maleation of these natural-based rosins; coumarone-indene resins; and the like.

[0177] Among these, a substance having a softening point in the range of 100 to 160°C is more preferable, and a substance having a softening point in the range of 120 to 150°C is particularly preferable. If a tackifying resin having a softening point in the above range is used, not only is the contamination of the support substrate less, but also the adhesion to the support substrate under the working environment can be further improved. Further, if a polymerized rosin ester-based tackifying resin is used as the tackifying resin, not only is the contamination of the support substrate less, but also the adhesion to the support substrate under an environment of 80 to 130°C is improved, and in the case of a heat-expandable adhesive containing heat-expandable microspheres, the support substrate can be easily peeled off from the support substrate after the heat-expandable microspheres are expanded.

[0178] The blending ratio of the tackifying resin is not particularly limited as long as it is appropriately selected in a manner that the elastic modulus of the adhesive resin layer (B) is adjusted to a desired predetermined range, but, from the viewpoint of the elastic modulus and the 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 (Bl). If the blending ratio of the tackifying resin is above the above lower limit value relative to 100 parts by mass of the adhesive resin (Bl), there is a tendency that the adhesion to the support substrate during work becomes good. On the other hand, if it is below the above upper limit value, there is a tendency that the adhesion to the support substrate at room temperature becomes good. From the viewpoint of the adhesion to the support substrate and the adhesion at room temperature, it is further preferable that the blending ratio of the tackifying resin is 2 to 50 parts by mass relative to 100 parts by mass of the adhesive resin (Bl). In addition, the acid value of the tackifying resin is preferably 30 or less. If the acid value of the tackifying resin is below the above upper limit value, there is a tendency that the support substrate is less likely to be contaminated with a residue at the time of peeling.

[0179] The adhesive resin layer (B) can contain an additive such as a plasticizer as an additional component. The total of the contents of the adhesive resin (Bl), the crosslinking agent (B2), and the tackifying resin in the adhesive resin layer (B) is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 90% by mass or more, and particularly preferably 95% by mass or more, when the entirety of the adhesive resin layer (B) is taken as 100% by mass. Further, in the case where the adhesive resin layer (B) is composed of a heat-expandable adhesive, the total of the contents of the adhesive resin (Bl), the crosslinking agent (B2), the tackifying resin, the gas generating component, and the heat-expandable microspheres in the adhesive resin layer (B) is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 90% by mass or more, and particularly preferably 95% by mass or more, when the entirety of the adhesive resin layer (B) is taken as 100% by mass.

[0180] The thickness of the adhesive resin layer (B) is not particularly limited, and is preferably 5 μm or more and 300 μm or less, more preferably 20 μm or more and 150 μm or less, for example.

[0181] The adhesive resin layer (B) can be formed, for example, by a method in which an adhesive coating liquid is applied onto the base material layer 10, a method in which an adhesive resin layer (B) formed on a separator is transferred onto the base material layer 10, or the like.

[0182] As the method of applying the adhesive coating liquid, a conventionally known coating method such as roll coating, reverse roll coating, gravure roll coating, bar coating, hopper coating, die coating, or the like can be employed. The drying conditions of the applied adhesive are not particularly limited, and in general, drying is preferably performed at a temperature in the range of 80 to 200°C for 10 seconds to 10 minutes. Further, drying is more preferably performed at 80 to 170°C for 15 seconds to 5 minutes. In order to sufficiently promote the crosslinking reaction of the crosslinking agent with the adhesive, heating at 40 to 80°C for 5 to 300 hours or so can be performed after the completion of drying of the adhesive coating liquid.

[0183] Further, the base material layer 10 and the adhesive resin layer (B) can be formed by co-extrusion molding, or can be formed by laminating (stacking) a film-shaped base material layer 10 and a film-shaped adhesive resin layer (B).

[0184] <Other Layer>

[0185] The adhesive film 50 according to the present embodiment can further have, for example, a concave-convex absorbing layer, an impact absorbing layer, an easily adherable layer, or the like provided between the base material layer 10 and the adhesive resin layer (A) or between the base material layer 10 and the adhesive resin layer (B) without impairing the effects of the present embodiment.

[0186] The unevenness-absorbing layer is preferably formed of natural rubber, synthetic rubber, or a synthetic resin having rubber elasticity, which has a Shore D hardness of, for example, 50 or less, preferably 40 or less, as measured by a D-type Shore hardness meter according to ASTM D-2240. The thickness of the unevenness-absorbing layer is, for example, 500 μm or less, preferably 5 to 300 μm, more preferably 10 to 150 μm.

[0187] As the synthetic rubber or synthetic resin, for example, synthetic rubbers such as nitrile-based, diene-based, and acrylic-based synthetic rubbers, thermoplastic elastomers such as polyolefin-based and polyester-based synthetic rubbers, ethylene-vinyl acetate copolymers, polyurethanes, polybutadienes, and soft polyvinyl chlorides, and the like having rubber elasticity can be given. Also, even a polymer such as polyvinyl chloride, which is essentially hard, can be used in the present embodiment, as long as it has rubber elasticity by being combined with a plasticizer, softening agent, or the like. Furthermore, the adhesive resins exemplified in the above-mentioned adhesive resin layer (A) and adhesive resin layer (B), and the like can also be preferably used for the formation of the unevenness-absorbing layer.

[0188] The above describes the embodiments of the present application, but they are examples of the present application, and various configurations other than the above can also be employed.

[0189] Furthermore, the present application is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope of achieving the objects of the present application are included in the present application.

[0190] Example

[0191] Hereinafter, the present application will be specifically described by way of examples, but the present application is not limited thereto.

[0192] Details of the materials used for the production of the adhesive film are as follows.

[0193] <Adhesive Resin Solution SA1>

[0194] In deionized pure water, 0.5 parts by mass of 4,4'-azobis-4-cyanovaleric acid (Otsuka Chemical Co., Ltd., trade name: ACVA) as a polymerization initiator, 74.3 parts by mass of n-butyl acrylate as a monomer (al), 13.7 parts by mass of methyl methacrylate as a monomer (al), 9 parts by mass of 2-hydroxyethyl methacrylate as a monomer (a2), and 3 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 a polyoxyethylene nonylphenyl ether (the first industrial Co., Ltd.; trade name: Akucell HS-1025) as a polymerizable surfactant were respectively added, and emulsion polymerization was performed at 70 to 72°C for 8 hours with stirring to obtain an acrylic resin emulsion. This was neutralized with ammonia water (pH = 7.0) to obtain an adhesive resin solution SA1 having a solid content concentration of 42.5%.

[0195] <Adhesive resin solution SA2>

[0196] In deionized pure water, 0.5 parts by mass of ammonium persulfate as a polymerization initiator, 63 parts by mass of 2-ethylhexyl acrylate as monomer (al), 21 parts by mass of n-butyl acrylate, and 9 parts by mass of methyl methacrylate as monomers (al), 3 parts by mass of 2-hydroxyethyl methacrylate as monomer (a2), 1 part by mass of polytetramethylene ether glycol diacrylate (manufactured by Nippon Oil & Fats Co., Ltd., trade name: ADT-250) as monomer (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 the First Industrial Co., Ltd.; trade name: Akucell HS-1025) as a polymerizable surfactant were separately put in, and emulsion polymerization was performed at 70 to 72°C for 8 hours with stirring to obtain an acrylic resin emulsion. This was neutralized with ammonia water (pH = 7.0) to obtain an adhesive resin solution SA2 having a solid content concentration of 56.5%.

[0197] <Adhesive coating liquid Al>

[0198] An adhesive coating liquid Al was obtained by mixing 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 (manufactured by Nagase Chemtex Corporation, Ex-1610) as a crosslinking agent.

[0199] <Adhesive resin solution SB1>

[0200] In a mixed solvent containing ethyl acetate and toluene, 0.536 parts by mass of t-butyl peroxy-2-ethylhexanoate (manufactured by Nippon Oil & Fats Co., Ltd., trade name: Perbutyl O (registered trademark)) as a polymerization initiator, 34.9 parts by mass of 2-ethylhexyl acrylate as monomer (bl), 41 parts by mass of n-butyl acrylate, and 14.7 parts by mass of ethyl acrylate as monomers (bl), and 9.4 parts by mass of 2-hydroxyethyl methacrylate as monomer (b2) were separately put in, and solution polymerization was performed at 83 to 87°C for 11 hours with stirring to obtain an acrylic resin solution having a solid content concentration of 45 mass%. This was set as an adhesive resin solution SB1.

[0201] <Adhesive coating liquid Bl>

[0202] A pressure-sensitive adhesive coating liquid B2 was prepared by mixing 100 parts by mass of the pressure-sensitive adhesive solution SB1, 2.25 parts by mass of a polymeric rosin ester-based tackifier (Arakawa Chemical Industries, Ltd., trade name: Pencel D-125) (5 parts by mass relative to 100 parts by mass of the pressure-sensitive adhesive), 1.2 parts by mass of an isocyanate-based crosslinking agent (Mitsui Chemicals, Inc., trade name: Olester P49-75S) (2 parts by mass relative to 100 parts by mass of the pressure-sensitive adhesive), and 6.75 parts by mass of thermally expandable microspheres (Nippon Shokubai Co., Ltd., trade name: Advancell EM-503) (15 parts by mass relative to 100 parts by mass of the pressure-sensitive adhesive), and adjusting the solid content concentration to 30% with ethyl acetate.

[0203] <Pressure-sensitive adhesive coating liquid B2>

[0204] A pressure-sensitive adhesive coating liquid B2 was prepared by mixing 100 parts by mass of the pressure-sensitive adhesive solution SB1, 2.25 parts by mass of a polymeric rosin ester-based tackifier (Arakawa Chemical Industries, Ltd., trade name: Pencel D-125) (5 parts by mass relative to 100 parts by mass of the pressure-sensitive adhesive), 1.2 parts by mass of an isocyanate-based crosslinking agent (Mitsui Chemicals, Inc., trade name: Olester P49-75S) (2 parts by mass relative to 100 parts by mass of the pressure-sensitive adhesive), and 6.75 parts by mass of thermally expandable microspheres (Nippon Shokubai Co., Ltd., trade name: Advancell EM-503) (15 parts by mass relative to 100 parts by mass of the pressure-sensitive adhesive), and adjusting the solid content concentration to 30% with ethyl acetate.

[0205] [Example 1]

[0206] On a polyethylene terephthalate (PET) film (thickness: 38 μm) as a base material layer, a pressure-sensitive resin layer (A) having a thickness of 10 μm formed by drying the pressure-sensitive adhesive coating liquid Al was provided. Next, on the surface of the PET film on the opposite side from the pressure-sensitive resin layer (A), a concavo-convex absorption layer having a thickness of 20 μm formed by drying the pressure-sensitive adhesive coating liquid Bl was provided, and on this, a heat-peeling type pressure-sensitive resin layer (B) having a thickness of 30 μm formed by drying the pressure-sensitive adhesive coating liquid B2 was provided, thereby obtaining a pressure-sensitive film.

[0207] The pressure-sensitive resin layer (B) side of the obtained pressure-sensitive film was attached to a 320 mm square SUS substrate, and as an electronic component, a 5 mm square semiconductor chip was placed on the pressure-sensitive resin layer (A) of the pressure-sensitive film in a lattice pattern at intervals of 2 mm and made to adhere, thereby obtaining a structure.

[0208] Next, the obtained structure was subjected to heat treatment at 100°C for 30 minutes, thereby performing pre-baking of the structure.

[0209] Here, for the structure after pre-baking, the positional displacement of the semiconductor chip was observed by visual inspection, and evaluation was performed using the following criteria.

[0210] O: No positional displacement of all electronic components

[0211] X: At least one electronic component has moved from the original position

[0212] Further, for the structure after pre-baking, the presence or absence of thermal expansion of the adhesive resin layer (B) was observed by visual observation, and the following criteria were used for evaluation. The results obtained are shown in Table 1.

[0213] O: The appearance of the adhesive resin layer (B) was not changed

[0214] X: The adhesive resin layer (B) has expanded

[0215] Next, using a compression molding machine, a plurality of semiconductor chips on the adhesive resin layer (A) were sealed by compression molding using a granular epoxy resin-based sealing material (manufactured by Sumitomo Bakelite Co., Ltd., product name: G730) at 135°C, and an electronic device was obtained.

[0216] Next, the positional displacement of the semiconductor chips was observed by visual observation, and the following criteria were used for evaluation. The results obtained are shown in Table 1.

[0217] O: All electronic components had no positional displacement

[0218] X: At least one electronic component has moved from the original position

[0219] [Examples 2 to 6]

[0220] The conditions of the heating treatment in the pre-baking step were changed to those shown in Table 1, and otherwise, the same method as in Example 1 was used to produce a structure and an electronic device, and the same evaluation as in Example 1 was performed.

[0221] The results obtained are shown in Table 1.

[0222] [Comparative Example 1]

[0223] Except that the pre-baking step was not performed, the same method as in Example 1 was used to produce a structure and an electronic device, and the same evaluation as in Example 1 was performed.

[0224] The results obtained are shown in Table 1.

[0225] [Table 1]

[0226]

[0227] Explanation of symbols

[0228] A: Adhesive resin layer, B: Adhesive resin layer, 10: Base material layer, 10A: First surface, 10B: Second surface, 50: Adhesive film, 60: Sealing material, 70: Electronic component, 80: Support substrate, 100: Structure, 200: Electronic device, 300: Electronic device, 310: Wiring layer, 320: Bump, 400: Electronic device.

[0229] This application claims priority to Japanese Application No. 2019-046792, filed March 14, 2019, the disclosure of which is incorporated herein in its entirety.

Claims

1. A method for manufacturing an electronic device, comprising at least the following steps: Preparation process for a structure containing an adhesive film, electronic components, and a supporting substrate; A pre-baking process that heats the structure; and A sealing process in which the electronic components are sealed using a sealing material. The adhesive membrane comprises: Substrate layer; An adhesive resin layer A disposed on the first side of the substrate layer for temporarily fixing electronic components; and An adhesive resin layer B is disposed on the second side of the substrate layer and whose adhesive strength is reduced by external stimulation. The electronic component is bonded to the adhesive resin layer A of the adhesive film. The supporting substrate is bonded to the adhesive resin layer B of the adhesive film.

2. The method for manufacturing an electronic device according to claim 1, wherein the heating temperature in the pre-baking process is less than 160°C.

3. In the method for manufacturing an electronic device according to claim 1 or 2, the heating temperature in the pre-baking process is above 70°C.

4. The method for manufacturing an electronic device according to any one of claims 1 to 3, further comprising, after the sealing process, a first peeling process: reducing the adhesiveness of the adhesive resin layer B by applying external stimulation to peel the support substrate from the structure.

5. The method for manufacturing an electronic device according to claim 4, further comprising a second peeling step after the first peeling step: peeling the adhesive film from the electronic component.

6. The method for manufacturing an electronic device according to any one of claims 1 to 5, wherein the sealing material is an epoxy resin-based sealing material.

7. The method for manufacturing an electronic device according to any one of claims 1 to 6, wherein the adhesive resin constituting the adhesive resin layer (A) comprises one or more selected from (meth)acrylic adhesive resin, silicone adhesive resin, urethane adhesive resin, olefin adhesive resin and styrene adhesive resin.

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