Method for manufacturing electronic component

Abstract

This method for manufacturing an electronic component comprises a step (a) for backgrinding an electronic component (10) temporarily fixed to a support substrate (20) via an adhesive film (100) including: a substrate layer (A); an adhesive resin layer (B) for temporarily fixing the electronic component (10) to a first surface A1 side of the substrate layer (A); an adhesive resin layer (C) for temporarily fixing the support substrate (20) to a second surface A2 side of the substrate layer (A); and an intermediate layer (D) positioned between the substrate layer (A) and the adhesive resin layer (B), between the substrate layer (A) and the adhesive resin layer (C), or between the substrate layer (A) and the adhesive resin layer (B) as well as between the substrate layer (A) and the adhesive resin layer (C), wherein at least one of the adhesive resin layer (B) or the adhesive resin layer (C) includes a layer in which the adhesiveness is reduced by an external stimulus. The method for manufacturing an electronic component further comprises a step (b) for reducing the adhesiveness of at least one of the adhesive resin layer (B) or the adhesive resin layer (C) by an external stimulus.

Description

Manufacturing method of electronic components

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

[0002] Some manufacturing methods for electronic devices include a process of forming a circuit on an electronic component, followed by a process of backgrinding, ion implantation, laser annealing, sputtering, or the like, on the surface of the electronic component opposite the circuit-formed surface. In these processes, an adhesive film is used to protect the circuit-formed surface of the electronic component. Patent Document 1, for example, describes a technology related to such an adhesive film.

[0003] Patent Document 1 describes a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer containing a pressure-sensitive adhesive including a base polymer and a foaming agent having a foaming temperature of 90° C. or higher, and when the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet is attached to a silicon chip, the shear adhesive strength is 1.0 MPa or higher at an ambient temperature of 25° C. and 0.2 MPa or higher at an ambient temperature of 80° C. Patent Document 1 also describes that "the present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a pressure-sensitive adhesive sheet that can be used for grinding hard and brittle substrates in a back-grinding process of the hard and brittle substrates, which is excellent in all of grinding accuracy, low contamination, productivity, and fixation."

[0004] Japanese Patent Application Laid-Open No. 2020-041007

[0005] The present invention provides a method for manufacturing an electronic component that can suppress the generation of bubbles that occur when an adhesive film is attached to an electronic component and a supporting substrate.

[0006] According to the present invention, there is provided a method for manufacturing an electronic component as follows.

[0007] 1. A method for manufacturing an electronic component, comprising the step (a) of backgrinding an electronic component temporarily fixed to a support substrate via an adhesive film, wherein the adhesive film comprises: a base layer (A); an adhesive resin layer (B) for temporarily fixing the electronic component on a first surface side of the base layer (A); and an adhesive resin layer (C) for temporarily fixing a support substrate on a second surface side of the base layer (A); and an intermediate layer (D) in at least one selected from between the base layer (A) and the adhesive resin layer (B) and between the base layer (A) and the adhesive resin layer (C), wherein at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) comprises a layer whose adhesive strength is reduced by an external stimulus, and the method for manufacturing an electronic component further comprises the step (b) of reducing the adhesive strength of at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) by an external stimulus. The method for producing an electronic component according to 1., wherein at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) comprises one or more types selected from the group consisting of a heat-peelable adhesive resin layer and a light-peelable adhesive resin layer. 3. The method for producing an electronic component according to 2., wherein the heat-peelable adhesive resin layer comprises an adhesive resin layer whose adhesive strength decreases or is lost when heated at a temperature exceeding 100°C. 4. The method for producing an electronic component according to any of 1. to 3., wherein the adhesive resin (C1) constituting the adhesive resin layer (C) comprises one or more types selected from the group consisting of (meth)acrylic resins, urethane resins, silicone resins, polyolefin resins, polyester resins, polyamide resins, fluorine-based resins, and styrene-diene block copolymer resins. 5. The method for producing an electronic component according to any of 1. to 4., wherein the thickness of the adhesive resin layer (C) is 1 μm or more and 500 μm or less. 6. 6. The method for producing an electronic component according to any one of 1. to 5., wherein the adhesive resin constituting the adhesive resin layer (B) comprises one or more selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins.7. The method for producing an electronic component according to any one of 1. to 6., wherein the thickness of the adhesive resin layer (B) is 1 μm or more and 500 μm or less. 8. The method for producing an electronic component according to any one of 1. to 7., wherein the intermediate layer (D) includes a layer that hardens in response to an external stimulus. 9. The method for producing an electronic component according to 8., wherein the intermediate layer (D) includes a crosslinking agent. 10. The method for producing an electronic component according to 9., wherein the crosslinking agent includes one or more selected from the group consisting of polyfunctional (meth)acrylate compounds and isocyanate compounds. 11. The method for producing an electronic component according to any one of 1. to 10., wherein the intermediate layer (D) includes one or more selected from the group consisting of thermal initiators and photoinitiators. 12. 11. The method for producing an electronic component according to 11., wherein the thermal initiator comprises one or more selected from the group consisting of aromatic ketones, onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and azo compounds. 13. The method for producing an electronic component according to 11. or 12., wherein the photoinitiator comprises an alkylphenone photoinitiator. 14. The storage modulus E' at 125°C of intermediate layer (D') obtained by crosslinking intermediate layer (D) is 1.0 x 10. ６ Pa or more 1.0×10 ９15. The method for producing an electronic component according to any one of 1. to 14., wherein the thickness of the intermediate layer (D) is 5 μm or more and 1000 μm or less. 16. The method for producing an electronic component according to any one of 1. to 15., wherein the substrate layer (A) comprises a thermoplastic resin. 17. The method for producing an electronic component according to any one of 1. to 16., wherein the thickness of the substrate layer (A) is 1 μm or more and 500 μm or less. 18. The method for producing an electronic component according to any one of 1. to 17., wherein the electronic component comprises a semiconductor wafer. 19. The method for producing an electronic component according to 18., wherein the semiconductor wafer is a sapphire wafer, indium-phosphorus wafer, silicon-carbon wafer, gallium-nitrogen wafer, gallium-arsenic wafer, silicon wafer, germanium wafer, germanium-arsenic wafer, gallium-phosphorus wafer, gallium-arsenic-aluminum wafer, or lithium tantalate wafer. 20. The method for producing an electronic component according to any one of 1. to 19., wherein the electronic component includes a circuit formation surface. 21. The method for producing an electronic component according to any one of 1. to 20., wherein in step (a), the electronic component is back-ground to reduce the thickness of the electronic component to 100 μm or less. 22. The method for producing an electronic component according to any one of 1. to 21., further comprising step (c) of treating the surface of the electronic component opposite the adhesive film side in a vacuum atmosphere. 23. The method for producing an electronic component according to 22., wherein step (c) includes at least one selected from the group consisting of an ion implantation step, a metal film formation step, and an annealing treatment step. 24. The method for producing an electronic component according to any one of 1. to 23., further comprising step (d) of curing the intermediate layer (D) by an external stimulus.

[0008] According to the present invention, it is possible to provide a method for manufacturing an electronic component that can suppress the generation of bubbles that occur when an adhesive film is attached to an electronic component and a supporting substrate.

[0009] 1A and 1B are cross-sectional views schematically showing an example of the structure of an adhesive film according to an embodiment of the present invention; 2A and 2B are cross-sectional views schematically showing an example of a method for manufacturing an electronic component according to an embodiment of the present invention;

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by common reference numerals, and descriptions thereof will be omitted where appropriate. Furthermore, the drawings are schematic diagrams and do not necessarily correspond to actual dimensional proportions.

[0011] In the present specification, "(meth)acrylic" means acrylic, methacrylic, or both acrylic and methacrylic.

[0012] The adhesive film 100 according to this embodiment will be described below. Fig. 1 is a cross-sectional view schematically showing an example of the structure of the adhesive film 100 according to an embodiment of the present invention. Fig. 2 is a cross-sectional view schematically showing an example of a method for manufacturing an electronic component 10 according to this embodiment.

[0013] The method for producing an electronic component of this embodiment includes a step (a) of backgrinding an electronic component (10) temporarily fixed to a support substrate (20) via an adhesive film (100), wherein the adhesive film (100) includes a base layer (A), an adhesive resin layer (B) for temporarily fixing the electronic component (10) on a first surface (A1) of the base layer (A), an adhesive resin layer (C) for temporarily fixing the support substrate (20) on a second surface (A2) of the base layer (A), and an intermediate layer (D) in at least one selected from between the base layer (A) and the adhesive resin layer (B) and between the base layer (A) and the adhesive resin layer (C), and at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) includes a layer whose adhesive strength is reduced by an external stimulus, and the method for producing an electronic component of this embodiment further includes a step (b) of reducing the adhesive strength of at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) by an external stimulus.

[0014] In this embodiment, the external stimulus is, for example, radiation such as ultraviolet light, electron beams, or infrared light, or heat.

[0015] According to the investigations of the present inventors, it has become clear that when an adhesive film 100 having adhesive resin layers on both sides is attached to an electronic component 10 and a support substrate 20, air bubbles are generated at the interface between the electronic component 10 and / or the support substrate 20 and the adhesive film 100. The cause of the air bubbles is not clear, but it is thought that one cause of the air bubbles is, for example, slight undulations in the adhesive film 100. When the adhesive film 100 has slight undulations, gaps are generated at the interface between the electronic component 10 and / or the support substrate 20 and the adhesive film 100, which is thought to be the cause of the air bubbles.

[0016] If bubbles are generated at the interface between the electronic component 10 and / or the support substrate 20 and the adhesive film 100, thickness variations due to the bubbles may occur when the electronic component 10 is ground. That is, the total thickness variation (TTV) of the electronic component 10 increases. Furthermore, if bubbles are generated at the interface between the electronic component 10 and / or the support substrate 20 and the adhesive film 100, in a subsequent heating vacuum process such as sputtering, the bubbles will expand under vacuum, causing lifting, which will result in insufficient cooling of that portion, resulting in scorching or delamination.

[0017] The mechanism by which the adhesive film 100 of this embodiment can suppress the generation of bubbles is not clear, but it is speculated that the intermediate layer (D) of this embodiment contributes to suppressing undulation of the film, thereby suppressing the generation of bubbles.

[0018] In the pressure-sensitive adhesive film 100 of this embodiment, the pressure-sensitive adhesive resin layer (B) for temporarily fixing the electronic component 10 preferably includes a layer whose adhesive strength decreases in response to an external stimulus, thereby reducing the force required to peel the pressure-sensitive adhesive film 100 from the electronic component 10, and preventing damage to the electronic component 10.

[0019] At least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) preferably contains one or more selected from the group consisting of a heat-peelable adhesive resin layer and a light-peelable adhesive resin layer, which allows the adhesive strength of the adhesive film 100 to be reduced by a simple method such as heating or light irradiation.

[0020] The heat-peelable adhesive resin layer preferably includes an adhesive resin layer whose adhesive strength is reduced or lost when heated at a temperature preferably exceeding 100°C, more preferably exceeding 120°C, even more preferably exceeding 150°C, and even more preferably exceeding 170°C.

[0021] From the viewpoint of improving the balance between mechanical properties and handling properties, the thickness of the entire adhesive film 100 is preferably 20 μm or more and 2000 μm or less, more preferably 30 μm or more and 1000 μm or less, even more preferably 50 μm or more and 800 μm or less, even more preferably 70 μm or more and 700 μm or less, even more preferably 80 μm or more and 600 μm or less, even more preferably 100 μm or more and 550 μm or less, and even more preferably 120 μm or more and 500 μm or less.

[0022] Each layer of the adhesive film 100 of this embodiment will be described below.

[0023] <Adhesive Resin Layer (C)> The adhesive resin layer (C) will be described below.

[0024] The adhesive resin layer (C) is located on the second surface A2 side of the base material layer (A) of this embodiment, and is a layer for adhering to the support substrate 20.

[0025] The adhesive resin layer (C) preferably includes a layer whose adhesive strength decreases with an external stimulus. This allows the adhesive film 100 to be easily peeled off from the support substrate 20 by applying an external stimulus. Examples of the adhesive resin layer (C) whose adhesive strength decreases with an external stimulus include a heat-peelable adhesive resin layer whose adhesive strength decreases with heating, and a light-peelable adhesive resin layer whose adhesive strength decreases with light such as ultraviolet light or radiation. Methods for applying the external stimulus include light irradiation and heat treatment.

[0026] The adhesive resin layer (C) contains, for example, an adhesive resin (C1).

[0027] The heat-peelable adhesive resin layer (C) contains one or more types selected from the group consisting of, for example, a heat-expandable adhesive resin layer containing a gas-generating component, a heat-expandable adhesive resin layer containing heat-expandable microspheres that can expand to reduce adhesive strength, and a heat-crosslinkable adhesive resin layer in which adhesive strength is reduced by a crosslinking reaction of the adhesive component due to heat, etc. Among these, from the viewpoint of further suppressing misalignment of the electronic component 10 and further simplifying the manufacturing method, the adhesive resin layer (C) of this embodiment preferably contains a heat-expandable adhesive resin layer.

[0028] The heat-peelable adhesive resin layer of this embodiment preferably includes an adhesive resin layer whose adhesive strength is reduced or lost by heating at a temperature above 100°C, more preferably at a temperature of 110°C or higher, even more preferably at a temperature of 120°C or higher, even more preferably at a temperature of 130°C or higher, even more preferably at a temperature of 150°C or higher, even more preferably at a temperature of 180°C or higher, even more preferably at a temperature of 200°C or higher, even more preferably at a temperature of 210°C or higher, and even more preferably at a temperature of 230°C or higher. For example, a material can be selected that does not peel at temperatures below 100°C but peels at temperatures above 100°C, and preferably has an adhesive strength sufficient to prevent the adhesive film 100 from peeling from the support substrate 20 during the manufacturing process of the electronic device. Here, the reduction or loss of adhesive strength due to heating at a temperature above 100°C can be evaluated, for example, by attaching the adhesive resin layer (C) side to a stainless steel plate, heat-treating at 90°C for 1 hour, and then heating at a temperature above 100°C for 2 minutes, and then measuring the peel strength from the stainless steel plate. The specific heating temperature when heating at a temperature exceeding 100°C is set to a temperature higher than the temperature at which gas is generated or the temperature at which the heat-expandable microspheres thermally expand, and is appropriately set depending on the type of gas generated and the type of heat-expandable microspheres. In this embodiment, loss of adhesive strength refers to, for example, a 180° peel strength of less than 0.5 N / 25 mm measured at 23°C and a tensile speed of 300 mm / min.

[0029] Examples of gas-generating components that can be used in the thermally expandable adhesive resin layer include azo compounds, azide compounds, Meldrum's acid derivatives, etc. Also usable are inorganic foaming agents such as ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium boron hydroxide, and various azides, water; fluorinated alkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate; paratoluenesulfonylhydrazide, diphenylsulfone-3,3'-disulfonylhydrazide, 4,4'-oxybis(benzenesulfonyl)hydrazide, and the like. Other examples of organic blowing agents that can be used include hydrazine compounds such as p-toluenesulfonylsemicarbazide and 4,4'-oxybis(benzenesulfonylsemicarbazide); semicarbazide compounds such as p-toluenesulfonylsemicarbazide and 4,4'-oxybis(benzenesulfonylsemicarbazide); triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole; and N-nitroso compounds such as N,N'-dinitrosopentamethylenetetramine and N,N'-dimethyl-N,N'-dinitrosoterephthalamide. The gas-generating component may be added to the adhesive resin (C1) or may be directly bonded to the adhesive resin (C1).

[0030] The heat-expandable microspheres used in the heat-expandable adhesive resin layer can be, for example, a microencapsulated blowing agent. Examples of such heat-expandable microspheres include microspheres in which a substance that easily gasifies and expands upon heating, such as isobutane, propane, or pentane, is encapsulated within an elastic shell. Examples of materials constituting the shell include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone. Heat-expandable microspheres can be produced, for example, by a coacervation method or an interfacial polymerization method. Heat-expandable microspheres can be added to the adhesive resin (C1).

[0031] The total content of the gas-generating component and the heat-expandable microspheres can be appropriately set depending on the expansion ratio and adhesive strength reduction of the heat-peelable adhesive resin layer (C) and is not particularly limited, but is preferably 1 to 150 parts by mass, more preferably 10 to 130 parts by mass, and even more preferably 12 to 100 parts by mass, per 100 parts by mass of the adhesive resin (C1) in the heat-peelable adhesive resin layer (C). It is preferable to design the temperature at which gas is generated and the temperature at which the heat-expandable microspheres thermally expand are above 100°C.

[0032] The adhesive resin (C1) constituting the adhesive resin layer (C) preferably contains one or more selected from the group consisting of (meth)acrylic resins, urethane resins, silicone resins, polyolefin resins, polyester resins, polyamide resins, fluorine-based resins and styrene-diene block copolymer resins, and more preferably contains a (meth)acrylic resin.

[0033] The adhesive resin layer (C) preferably further contains, in addition to the adhesive resin (C1), a crosslinking agent (C2) having two or more crosslinkable functional groups per molecule. The crosslinking agent (C2) having two or more crosslinkable functional groups per molecule is used to react with the functional groups of the adhesive resin (C1) to adjust the adhesive strength and cohesive strength. Examples of such crosslinking agents (C2) include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcinol diglycidyl ether; isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate; and trimethylolpropane-tri-β-aziridinylpropionate. Examples of suitable epoxy compounds include aziridine compounds such as tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate; tetrafunctional epoxy compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine compounds such as hexamethoxymethylolmelamine. These compounds may be used alone or in combination of two or more. Among these, it is preferable to use one or more compounds selected from epoxy compounds, isocyanate compounds, and aziridine compounds.

[0034] The content of the crosslinking agent (C2) in the adhesive resin layer (C) is preferably within a range such that the number of functional groups in the crosslinking agent (C2) is not greater than the number of functional groups in the adhesive resin (C1). However, if necessary, an excess of the crosslinking agent (C2) may be added when new functional groups are generated in the crosslinking reaction or when the crosslinking reaction is slow. The content of the crosslinking agent (C2) in the adhesive resin layer (C) is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 5 parts by mass or less, per 100 parts by mass of the adhesive resin (C1).

[0035] In order to further improve adhesion to the support substrate 20, the adhesive resin layer (C) of this embodiment preferably contains a tackifier resin in addition to the adhesive resin (C1). Incorporating a tackifier resin into the adhesive resin layer (C) is preferred because it facilitates adjustment of adhesion to the support substrate 20 at around room temperature. The tackifier resin preferably has a softening point of 100°C or higher. Specific examples of tackifier resins include rosin-based resins such as rosin derivatives treated with esterification or the like; terpene-based resins such as α-pinene, β-pinene, dipentene, and terpene phenol; natural rosins such as gum, wood, and tall oil; petroleum resins obtained by hydrogenating, disproportionating, polymerizing, or maleating these natural rosins; and coumarone-indene resins. Among these, those having a softening point in the range of 100 to 160°C are more preferred, and those in the range of 120 to 150°C are even more preferred.

[0036] The content of the tackifier resin in the adhesive resin layer (C) is preferably 1 part by mass or more and 100 parts by mass or less, more preferably 2 parts by mass or more and 50 parts by mass or less, per 100 parts by mass of the adhesive resin (C1).

[0037] The acid value of the tackifier resin is preferably 30 or less. This tends to make it less likely that adhesive residue will remain on the support substrate 20 when the adhesive film 100 is peeled off.

[0038] The adhesive resin layer (C) may contain additives such as a plasticizer as other components.

[0039] The total content of the adhesive resin (C1), the crosslinking agent (C2), and the tackifying resin in the adhesive resin layer (C) is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and even more preferably 95% by mass or more and 100% by mass or less, when the entire adhesive resin layer (C) is taken as 100% by mass.

[0040] When the adhesive resin layer (C) is constituted by a heat-expandable adhesive resin layer, the total content of the adhesive resin (C1), crosslinking agent (C2), tackifier resin, gas-generating component, and heat-expandable microspheres in the adhesive resin layer (C), when the entire adhesive resin layer (C) is taken as 100% by mass, is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and still more preferably 95% by mass or more and 100% by mass or less.

[0041] The photo-peeling adhesive resin layer (C) contains, for example, a photo-reactive adhesive resin (C3).

[0042] The photo-peeling adhesive resin layer (C) includes, for example, a photo-expandable adhesive resin layer containing a gas-generating component, a photo-expandable adhesive resin layer containing photo-expandable microspheres that can expand to reduce adhesive strength, and a photo-crosslinkable adhesive resin layer in which adhesive strength is reduced by a crosslinking reaction of the adhesive component upon irradiation with light.

[0043] The light source used to reduce the adhesive strength of the photo-peelable adhesive resin layer (C) is not particularly limited, but it is preferable to use a light source capable of irradiating ultraviolet light or visible light with a wavelength of 200 nm or more and 500 nm or less. Examples of such light sources include high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, and super UV lamps. In the case of ultraviolet crosslinking, for example, a high-pressure mercury lamp is used to irradiate ultraviolet light with a dominant wavelength of 365 nm at an irradiation intensity of 10 to 350 mW / cm in an environment of 0 to 60°C. ２ UV dose 100-20,000 mJ / cm ２ By irradiating the adhesive resin layer (C) under the above conditions, the adhesive resin layer (C) expands, reducing the adhesive strength, and can be peeled off.

[0044] The adhesive resin layer (C) may be a single layer or multiple layers. For example, by laminating two or more layers that expand to different degrees upon heating to form the adhesive resin layer (C), it is possible to change the adhesiveness and thermal releasability between one side and the other side of the adhesive resin layer (C).

[0045] The thickness of the adhesive resin layer (C) is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more, from the viewpoint of improving the performance balance between adhesiveness and releasability, and is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 200 μm or less, from the viewpoint of improving the handleability of the adhesive film 100, and is preferably 1 μm or more and 500 μm or less, more preferably 3 μm or more and 300 μm or less, and even more preferably 5 μm or more and 200 μm or less, from the viewpoint of improving the performance balance between adhesiveness, releasability, and handleability.

[0046] The adhesive resin layer (C) may be a single layer or two or more layers.

[0047] <Adhesive Resin Layer (B)> The adhesive resin layer (B) will be described below.

[0048] The adhesive resin layer (B) is a layer for temporarily fixing the electronic component 10 to the first surface A1 side of the base layer (A) of this embodiment.

[0049] The adhesive resin constituting the adhesive resin layer (B) preferably contains one or more selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins, and more preferably contains a (meth)acrylic adhesive resin having a (meth)acrylic polymer as a base polymer, from the viewpoint of making it easy to adjust the adhesive strength.

[0050] The adhesive resin constituting the adhesive resin layer (B) preferably contains a photo-crosslinkable adhesive resin whose adhesive strength decreases upon light irradiation. The adhesive resin layer (B) composed of the photo-crosslinkable adhesive resin crosslinks upon light irradiation, thereby decreasing its adhesive strength. Examples of light include ultraviolet light, electron beams, and infrared light. The photo-crosslinkable adhesive resin is preferably an ultraviolet-crosslinkable adhesive resin.

[0051] Examples of (meth)acrylic polymers contained in (meth)acrylic adhesive resins include homopolymers of (meth)acrylic acid ester compounds and copolymers of (meth)acrylic acid ester compounds and comonomers. Examples of (meth)acrylic acid ester compounds include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and glycidyl (meth)acrylate. These (meth)acrylic acid ester compounds may be used alone or in combination of two or more. Examples of comonomers constituting (meth)acrylic copolymers include vinyl acetate, (meth)acrylonitrile, (meth)acrylamide, styrene, (meth)acrylic acid, itaconic acid, (meth)acrylamide, methylol (meth)acrylamide, and maleic anhydride. These comonomers may be used alone or in combination of two or more.

[0052] The adhesive resin layer (B) contains, for example, a (meth)acrylic adhesive resin and a crosslinkable compound (a component having a carbon-carbon double bond).

[0053] Examples of crosslinkable compounds include monomers, oligomers, and polymers having a carbon-carbon double bond in the molecule and capable of crosslinking by radical polymerization. Examples of such crosslinkable compounds include esters of (meth)acrylic acid and polyhydric alcohols such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; ester (meth)acrylate oligomers; and isocyanurates or isocyanurate compounds such as 2-propenyldi-3-butenyl cyanurate, 2-hydroxyethylbis(2-(meth)acryloxyethyl)isocyanurate, and tris(2-methacryloxyethyl)isocyanurate. When the adhesive resin constituting the adhesive resin layer (B) is a radiation crosslinkable polymer having a carbon-carbon double bond in the side chain of the polymer, it is not necessary to add a crosslinkable compound.

[0054] The photopolymerization initiator may be any compound that is cleaved to generate radicals upon irradiation with radiation, and examples thereof include benzoin alkyl ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; aromatic ketones such as benzil, benzoin, benzophenone, and α-hydroxycyclohexyl phenyl ketone; aromatic ketals such as benzil dimethyl ketal; polyvinyl benzophenone; and thioxanthones such as chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, and diethylthioxanthone.

[0055] Examples of the thermal polymerization initiator include organic peroxide derivatives and azo-based polymerization initiators. Organic peroxide derivatives are preferred because they do not generate nitrogen during heating. Examples of the thermal initiator include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, and peroxydicarbonates.

[0056] The content of the (meth)acrylic adhesive resin in the adhesive resin layer (B) is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and even more preferably 95% by mass or more and 100% by mass or less, when the entire adhesive resin layer (B) is taken as 100% by mass. The total content of the (meth)acrylic adhesive resin and the crosslinkable compound in the adhesive resin layer (B) is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and even more preferably 95% by mass or more and 100% by mass or less, when the entire adhesive resin layer (B) is taken as 100% by mass. The total content of the (meth)acrylic adhesive resin, crosslinking compound, photopolymerization initiator, and thermal polymerization initiator in the adhesive resin layer (B) is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and even more preferably 95% by mass or more and 100% by mass or less, based on 100 parts by mass of the (meth)acrylic adhesive resin. When the content of the crosslinking compound is within the above range, it is easier to adjust the adhesive strength compared to when the content is less than the above range, and storage stability is less likely to decrease due to excessive sensitivity to heat and light compared to when the content is greater than the above range.

[0057] A cross-linking component other than the cross-linking compound (a component having a carbon-carbon double bond) may be added to the adhesive resin layer (B). Hereinafter, such a component will be referred to as a cross-linking agent. Examples of cross-linking agents include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, and diglycerol polyglycidyl ether; aziridine compounds such as tetramethylolmethane-tri-β-aziridinyl propionate, trimethylolpropane-tri-β-aziridinyl propionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), and N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide); and isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, and polyisocyanate.

[0058] The content of the crosslinking agent in the adhesive resin layer (B) is preferably 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the (meth)acrylic adhesive resin, from the viewpoint of improving the performance balance of the heat resistance and adhesion of the adhesive resin layer (B).

[0059] The thickness of the adhesive resin layer (B) is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more, from the viewpoint of improving the performance balance between adhesiveness and releasability, and is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 200 μm or less, from the viewpoint of improving the handleability of the adhesive film 100, and is preferably 1 μm or more and 500 μm or less, more preferably 3 μm or more and 300 μm or less, and even more preferably 5 μm or more and 200 μm or less, from the viewpoint of improving the performance balance between adhesiveness, releasability, and handleability.

[0060] The adhesive resin layer (B) may be a single layer or two or more layers.

[0061] <Intermediate Layer (D)> The intermediate layer (D) will be described below.

[0062] The intermediate layer (D) is a layer located at least one selected from between the base material layer (A) and the adhesive resin layer (B) and between the base material layer (A) and the adhesive resin layer (C).

[0063] The intermediate layer (D) preferably includes a layer that is cured by an external stimulus. When the intermediate layer (D) is cured, the elastic modulus of the pressure-sensitive adhesive film 100 can be improved, and the generation of bubbles can be further suppressed. Furthermore, when the intermediate layer (D) is cured, the heat resistance of the pressure-sensitive adhesive film 100 can be improved, and the pressure-sensitive adhesive film 100 can withstand high-temperature processes such as sputtering and CVD.

[0064] The resin constituting the intermediate layer (D) is not particularly limited, but preferably includes one or more types selected from the group consisting of (meth)acrylic resins, urethane resins, silicone resins, polyolefin resins, polyester resins, polyamide resins, fluorine-based resins, and styrene-diene block copolymer resins, more preferably includes one or more types selected from the group consisting of (meth)acrylic resins and polyolefin resins, and even more preferably includes a (meth)acrylic resin.

[0065] The intermediate layer (D) preferably contains a crosslinking agent, which allows the intermediate layer (D) to be crosslinked more effectively by light energy and thermal energy, thereby improving the elastic modulus of the intermediate layer (D).

[0066] The crosslinking agent used in the intermediate layer (D) of this embodiment may be, for example, one that undergoes a crosslinking reaction due to a chemical species generated from an initiator. The crosslinking agent used in the intermediate layer (D) of this embodiment preferably contains one or more compounds selected from the group consisting of polyfunctional (meth)acrylate compounds and isocyanate compounds. This allows the intermediate layer (D) to be crosslinked more effectively by light energy and thermal energy, thereby improving the elastic modulus of the intermediate layer (D).

[0067] Examples of crosslinking agents used in the intermediate layer (D) of this embodiment include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcinol diglycidyl ether; isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate; and trimethylolpropane-tri-β-aziridinyl Examples of suitable aziridine compounds include propionate, tetramethylolmethane-tri-β-aziridinyl propionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate; tetrafunctional epoxy compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine compounds such as hexamethoxymethylolmelamine. These may be used alone or in combination of two or more. Among these, the crosslinking agent used in the intermediate layer (D) of the present embodiment preferably contains one or more compounds selected from the group consisting of epoxy-based compounds, isocyanate-based compounds, and aziridine-based compounds, and more preferably contains an isocyanate-based compound.

[0068] The content of the crosslinking agent in the intermediate layer (D) is preferably within a range such that the number of functional groups in the crosslinking agent is not greater than the number of functional groups in the adhesive resin. However, if new functional groups are generated in the crosslinking reaction or if the crosslinking reaction is slow, an excess amount may be added as necessary. The content of the crosslinking agent in the intermediate layer (D) is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 5 parts by mass or less, per 100 parts by mass of the resin in the intermediate layer (D).

[0069] The total content of the resin and the crosslinking agent in the intermediate layer (D) is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and even more preferably 95% by mass or more and 100% by mass or less, when the entire intermediate layer (D) is taken as 100% by mass.

[0070] The intermediate layer (D) preferably contains one or more selected from the group consisting of thermal initiators and photoinitiators. This allows the intermediate layer (D) to be crosslinked more effectively by thermal energy and light energy, thereby improving the elastic modulus of the intermediate layer (D). The chemical species generated from the thermal initiator and / or photoinitiator may be appropriately selected based on the functional groups possessed by the resin and / or crosslinking agent. The chemical species generated from the photoinitiator is typically a radical or cation.

[0071] The thermal initiator of this embodiment is not particularly limited as long as it is capable of crosslinking the intermediate layer (D) using thermal energy. For example, it may include one or more selected from the group consisting of aromatic ketones, onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and azo compounds. From the viewpoints of availability and ease of handling, it preferably includes an azo compound or an organic peroxide, and more preferably includes an organic peroxide. The chemical species generated from the thermal initiator may be appropriately selected based on the functional groups possessed by the resin and / or crosslinking agent. The chemical species generated from the thermal initiator is typically a radical or cation.

[0072] Commercially available thermal initiators include V-70, V-65, V-601, V-59, V-40, VF-096, V-30, VAm-110, and VAm-111 (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), Niper BW, Niper BMT, Perloyl TCP, Perloyl L, Perloyl 355, Perloyl SA, Perhexa HC, Perbutyl 355, Perbutyl D, Perbutyl L, Perbutyl ND, Perocta O, Perhexyl D, Perhexyl O, and Perhexyl PV (all manufactured by NOF Corporation), Trigonox 36-C75, Laurox, Perkadox L-W75, Perkadox CH-50L, Trigonox TMBH, Kayacumen H, Kayabutyl H-70, Perkadox BC-FF, and Kayahe Examples of the hydroxybenzoates include Xa AD, Perkadox 14, Kayabutyl C, Kayabutyl D, Perkadox 12-XL25, Trigonox 22-N70 (22-70E), Trigonox D-T50, Trigonox 423-C70, Kayaester CND-C70, Trigonox 23-C70, Trigonox 257-C70, Kayaester P-70, Kayaester TMPO-70, Trigonox 121, Kayaester O, Kayaester HTP-65W, Kayaester AN, Trigonox 42, Trigonox F-C50, Kayabutyl B, Kayacarbon EH, Kayacarbon I-20, Kayacarbon BIC-75, Trigonox 117, and Kayalene 6-70 (all manufactured by Kayaku Akzo Co., Ltd.).

[0073] The content of the thermal initiator in the intermediate layer (D) is preferably 0.1 parts by mass or more and 7 parts by mass or less, more preferably 0.3 parts by mass or more and 3 parts by mass or less, and even more preferably 0.5 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the resin in the intermediate layer (D).

[0074] The photoinitiator of this embodiment is not particularly limited as long as it is capable of crosslinking the intermediate layer (D) using light energy. For example, it may include one or more species selected from the group consisting of alkylphenone-based photoinitiators, acetophenone-based photoinitiators, oxime ester-based photoinitiators, benzoin ether-based photoinitiators, acylphosphine oxide-based photoinitiators, α-ketol-based photoinitiators, aromatic sulfonyl chloride-based photoinitiators, photoactive oxime-based photoinitiators, benzoin-based photoinitiators, benzyl-based photoinitiators, benzophenone-based photoinitiators, and thioxanthone-based photoinitiators. From the viewpoints of high reactivity and low sublimation, an alkylphenone-based photoinitiator is preferably used. The chemical species generated from the photoinitiator may be appropriately selected based on the functional groups possessed by the resin and / or crosslinking agent. The chemical species generated from the photoinitiator is typically a radical or cation.

[0075] Specific examples of alkylphenone photoinitiators include 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-propan-1-one, 2-hydroxy-1-{[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, and the like. Specific examples of acetophenone-based photoinitiators include 1-hydroxycyclohexyl-phenyl-ketone, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, methoxyacetophenone, etc. Specific examples of oxime ester-based photoinitiators include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-2-(o-benzoyloxime), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(o-acetyloxime), etc. Specific examples of benzoin ether photoinitiators include benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, and benzoin isobutyl ether, as well as substituted benzoin ethers such as anisole methyl ether. Specific examples of acylphosphine oxide photoinitiators include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. Specific examples of α-ketol photoinitiators include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one.Specific examples of aromatic sulfonyl chloride photoinitiators include 2-naphthalenesulfonyl chloride. Specific examples of photoactive oxime photoinitiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Specific examples of benzoin photoinitiators include benzoin. Specific examples of benzyl photoinitiators include benzyl. Specific examples of benzophenone photoinitiators include benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, etc. Specific examples of the thioxanthone-based photoinitiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

[0076] As the photoinitiator, a photoinitiator that absorbs light having a wavelength of 300 nm or more (for example, light having a wavelength of 300 nm or more and 500 nm or less) and generates radicals can be preferably used. The photoinitiators can be used alone or in appropriate combination of two or more.

[0077] The content of the photoinitiator in the intermediate layer (D) is preferably 0.1 parts by mass or more and 7 parts by mass or less, more preferably 0.3 parts by mass or more and 3 parts by mass or less, and even more preferably 0.5 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the resin in the intermediate layer (D).

[0078] The storage modulus E' of the intermediate layer (D) at 60°C before crosslinking is preferably 1.0 x 10 ３ Pa or more, more preferably 5.0 × 10 ３ From the viewpoint of effectively absorbing the irregularities on the surface of the electronic component 10, the pressure is preferably 1.0×10 Pa or more. ６ Pa or less, more preferably 5.0 × 10 ５ From the viewpoint of effectively absorbing the irregularities on the surface of the electronic component 10, the pressure is preferably 1.0×10 Pa or less. ３ Pa or more 1.0×10 ６Pa or less, more preferably 5.0 × 10 ３ Pa or more 5.0×10 ５ The storage modulus E' of the intermediate layer (D) at 60°C before crosslinking can be controlled within the above range, for example, by controlling the types and blending ratios of the components constituting the intermediate layer (D) before crosslinking.

[0079] The storage modulus E' at 125°C of the intermediate layer (D') obtained by crosslinking the intermediate layer (D) is preferably 1.0 x 10 ６ Pa or more, more preferably 2.0 × 10 ６ Pa or more, more preferably 3.5 × 10 ６ Pa or more, more preferably 5.0 × 10 ６ Pa or more, more preferably 6.5 × 10 ６ Pa or more, more preferably 8.0 × 10 ６ From the viewpoint of further suppressing the generation of bubbles, the viscosity is preferably 1.0×10 ９ Pa or less, more preferably 5.0 × 10 ８ Pa or less, more preferably 2.0 × 10 ８ Pa or less, more preferably 1.0 × 10 ８ Pa or less, more preferably 5.0 × 10 ７ Pa or less, more preferably 1.0 × 10 ７ From the viewpoint of further suppressing the generation of bubbles, the viscosity is preferably 1.0×10 ６ Pa or more 1.0×10 ９ Pa or less, more preferably 2.0 × 10 ６ Pa or more 5.0×10 ８ Pa or less, more preferably 3.5 × 10 ６ Pa or more 2.0×10 ８ Pa or less, more preferably 5.0 × 10 ６ Pa or more 1.0×10 ８ Pa or less, more preferably 6.5 × 10 ６ Pa or more 5.0×10 ７ Pa or less, more preferably 8.0 × 10 ６ Pa or more 1.0×10 ７The storage modulus E' of the intermediate layer (D') at 125°C can be controlled within the above range, for example, by controlling the types and blending ratios of the components constituting the intermediate layer (D). Whether the crosslinking treatment of the intermediate layer (D) is complete can be determined, for example, by determining the point at which the storage modulus E' of the intermediate layer (D) no longer increases even after the crosslinking treatment.

[0080] From the viewpoint of further suppressing bubble generation, the thickness of the intermediate layer (D) is preferably 5 μm or more and 1,000 μm or less, more preferably 10 μm or more and 900 μm or less, even more preferably 15 μm or more and 800 μm or less, even more preferably 20 μm or more and 700 μm or less, even more preferably 25 μm or more and 600 μm or less, even more preferably 30 μm or more and 500 μm or less, even more preferably 35 μm or more and 400 μm or less, even more preferably 35 μm or more and 300 μm or less, even more preferably 35 μm or more and 200 μm or less, even more preferably 35 μm or more and 100 μm or less, and even more preferably 35 μm or more and 50 μm or less.

[0081] The method for forming the intermediate layer (D) is not particularly limited, and the same method as that for the adhesive resin layer (B) or the adhesive resin layer (C) can be used.

[0082] The intermediate layer (D) may be a single layer or two or more layers.

[0083] <Base layer (A)> The base layer (A) of this embodiment is a layer provided for the purpose of improving the properties of the pressure-sensitive adhesive film 100, such as ease of handling, mechanical properties, and heat resistance.

[0084] The base layer (A) of this embodiment preferably contains a thermoplastic resin. Examples of the thermoplastic resin include one or more selected from the group consisting of polyolefins such as polyethylene, polypropylene, poly(4-methyl-1-pentene), and poly(1-butene); polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyamides such as nylon-6, nylon-66, and polymethaxylene adipamide; polyacrylates; polymethacrylates; polyvinyl chloride; polyvinylidene chloride; polyimides; polyetherimides; ethylene-vinyl acetate copolymers; polyacrylonitrile; polycarbonates; polystyrenes; ionomers; polysulfones; polyethersulfones; and polyphenylene ethers. From the viewpoint of an excellent balance of transparency, mechanical strength, price, and the like, the thermoplastic resin preferably contains one or more selected from the group consisting of polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyamides, and polyimides, and more preferably contains one or two selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate.

[0085] The thickness of the substrate layer (A) of the present embodiment is preferably 1 μm or more and 500 μm or less, more preferably 5 μm or more and 300 μm or less, and even more preferably 10 μm or more and 200 μm or less, from the viewpoint of obtaining good film properties.

[0086] The base layer (A) of the present embodiment may be a stretched film or a uniaxially or biaxially stretched film, but is preferably a uniaxially or biaxially stretched film from the viewpoint of improving mechanical strength.

[0087] The substrate layer (A) of the present embodiment may be surface-treated to improve adhesion to other layers, specifically, corona treatment, plasma treatment, undercoat treatment, or primer coating treatment.

[0088] The substrate layer (A) may be a single layer or two or more layers.

[0089] <Other Layers> The pressure-sensitive adhesive film 100 of this embodiment may further include, for example, an easy-adhesion layer or the like between the layers, as long as the effect of this embodiment is not impaired.

[0090] <Electronic Component> Hereinafter, the electronic component 10 of this embodiment will be described.

[0091] The electronic component 10 of the present embodiment is not particularly limited, but includes, for example, a semiconductor wafer, a sapphire substrate, a lithium tantalate substrate, a mold wafer, a mold panel, a mold array package, an electronic component 10 obtained by singulating a semiconductor substrate or a semiconductor wafer, preferably a semiconductor wafer or a sapphire substrate, and more preferably a semiconductor wafer.

[0092] The semiconductor wafer of this embodiment preferably includes a sapphire wafer, an indium-phosphorus wafer, a silicon-carbon wafer, a gallium-nitrogen wafer, a gallium-arsenide wafer, a silicon wafer, a germanium wafer, a germanium-arsenide wafer, a gallium-phosphorus wafer, a gallium-arsenide-aluminum wafer, or a lithium tantalate wafer, and more preferably includes a sapphire wafer.

[0093] The electronic component 10 of this embodiment preferably includes a circuit formation surface A10.

[0094] The circuit-forming surface A10 of the electronic component 10 of this embodiment has, for example, circuits such as wiring, capacitors, diodes, or transistors formed on its surface. The circuit-forming surface A10 may also be subjected to plasma treatment. The circuit-forming surface A10 of the electronic component 10 may also have bump electrodes or the like, making it an uneven surface.

[0095] Bump electrodes are bonded to electrodes formed on a mounting surface when mounting an electronic device on the mounting surface, forming an electrical connection between the electronic device and the mounting surface (such as the mounting surface of a printed circuit board). Examples of bump electrodes include ball bumps, printed bumps, stud bumps, plated bumps, and pillar bumps. In other words, bump electrodes are typically convex electrodes. These bump electrodes may be used alone or in combination of two or more. The height and diameter of the bump electrodes are not particularly limited, but are preferably 10 μm or more, more preferably 50 μm or more, and preferably 400 μm or less, and more preferably 300 μm or less. The bump pitch is also not particularly limited, but is preferably 20 μm or more, more preferably 100 μm or more, and preferably 600 μm or less, and more preferably 500 μm or less. The bump electrodes may include, for example, one or more metals selected from the group consisting of solder, silver, gold, copper, tin, lead, bismuth, and alloys thereof, preferably solder.

[0096] <Step (a)> Step (a) will be described below.

[0097] The method for manufacturing an electronic component of this embodiment includes a step (a) of back-grinding electronic component 10 that has been temporarily fixed to support substrate 20 via adhesive film 100 .

[0098] In step (a), the surface of electronic component 10 opposite circuit-forming surface A10 is ground to a predetermined thickness. The thickness of electronic component 10 before grinding is determined appropriately depending on the diameter, type, etc. of electronic component 10, and the thickness of electronic component 10 after grinding is determined appropriately depending on the size of the resulting chip, type of circuit, etc.

[0099] The grinding method in step (a) is not particularly limited, and any known grinding method can be used. For example, grinding may be performed while cooling the electronic component 10 and the grinding stone by spraying grinding water on them, or grinding may be performed by a dry polishing method that does not use grinding water.

[0100] In step (a), chemical etching may be performed after grinding. The chemical etching is performed by, for example, immersing the electronic component 10 in a chemical etching solution. The chemical etching is performed for the purposes of removing distortion generated on the back surface of the electronic component 10, further thinning the electronic component 10, removing oxide films, etc., and pretreatment for forming electrodes on the back surface. The etching solution may include one or more selected from the group consisting of acidic aqueous solutions, such as hydrofluoric acid, nitric acid, sulfuric acid, and acetic acid, either alone or in combination, and alkaline aqueous solutions, such as potassium hydroxide and sodium hydroxide.

[0101] The pressure-sensitive adhesive film 100 of this embodiment can suppress the generation of air bubbles that occur when the pressure-sensitive adhesive film 100 is attached to the electronic component 10 and the support substrate 20, and can therefore suppress defects caused by the generation of air bubbles. Here, defects caused by the generation of air bubbles tend to occur more easily as the thickness of the back-ground electronic component 10 of this embodiment is thinner. Therefore, in step (a) of this embodiment, the electronic component 10 is back-ground to a thickness of the electronic component 10 of preferably 100 μm or less, more preferably 80 μm or less, even more preferably 60 μm or less, even more preferably 40 μm or less, and even more preferably 20 μm or less.

[0102] <Step (b)> Step (b) of this embodiment will be described below.

[0103] The method for producing an electronic component of this embodiment further includes a step (b) of reducing the adhesive strength of at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) by an external stimulus.

[0104] The method for producing an electronic component of this embodiment preferably further includes a step (b) of reducing the adhesive strength of at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) by an external stimulus, thereby reducing the force required to peel the adhesive film 100 from the electronic component 10 and the supporting substrate 20, and preventing damage to the electronic component 10.

[0105] The conditions of the external stimulus for reducing the adhesive strength of at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) may be appropriately set depending on the adhesive resin layer whose adhesive strength is to be reduced.

[0106] <Step (c)> Step (c) of this embodiment will be described below.

[0107] The method for producing an electronic component of this embodiment preferably further includes a step (c) of treating the surface of electronic component 10 opposite to the adhesive film 100 side in a vacuum atmosphere.

[0108] In step (c), the vacuum atmosphere means a low-pressure state obtained by reducing the pressure below atmospheric pressure using a vacuum device, and may be, for example, 1000 Pa or less, 100 Pa or less, or 10 Pa or less.

[0109] When the step (b) is performed under a high temperature condition, the temperature of the pressure-sensitive adhesive film 100 in the step (c) is preferably 60°C or higher and 230°C or lower, more preferably 80°C or higher and 210°C or lower, even more preferably 100°C or higher and 190°C or lower, even more preferably 120°C or higher and 170°C or lower, and even more preferably 140°C or higher and 170°C or lower.

[0110] The step (c) is not particularly limited and includes known methods, for example, at least one selected from the group consisting of an ion implantation step, a metal film formation step, and an annealing treatment step.

[0111] <Step (d)> Step (d) of this embodiment will be described below.

[0112] The method for producing an electronic component of this embodiment preferably further includes a step (d) of curing the intermediate layer (D) by an external stimulus. This further suppresses deformation of the pressure-sensitive adhesive film 100 and the generation of bubbles. The step (d) is preferably performed before the step (a).

[0113] The conditions of the external stimulus for curing the intermediate layer (D) may be appropriately set depending on the intermediate layer (D) to be cured.

[0114] <Other Steps> The method for manufacturing an electronic component according to this embodiment may include other steps as long as the effects of this embodiment are not impaired.

[0115] The method for manufacturing an electronic component of this embodiment includes any steps that are commonly performed in the manufacturing process of an electronic component, such as a resist step, a developing step, an ashing step, a sputtering step, a dicing step, a die bonding step, a wire bonding step, a flip chip connection step, a cure heating test step, a sealing step, and a reflow step.

[0116] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted.

[0117] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0118] The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited thereto.

[0119] The details of the method for producing the adhesive film are as follows.

[0120] <Preparation of Layer-Forming Coating Liquid> First, (meth)acrylic resin solution 1, (meth)acrylic resin emulsion 1, and (meth)acrylic resin emulsion 2, which are raw materials for the layer-forming coating liquid used to form each layer of the pressure-sensitive adhesive film, were prepared by the following procedure.

[0121] (Meth)acrylic resin solution 1: 49 parts by mass of ethyl acrylate, 20 parts by mass of 2-ethylhexyl acrylate, 21 parts by mass of methyl acrylate, 10 parts by mass of glycidyl methacrylate, and 0.5 parts by mass (solids content) of a benzoyl peroxide polymerization initiator were reacted in 65 parts by mass of toluene and 50 parts by mass of ethyl acetate at 80°C for 10 hours. After completion of the reaction, the resulting solution was cooled, and to the cooled solution were added 25 parts by mass of xylene, 5 parts by mass of acrylic acid, and 0.5 parts by mass of tetradecyldimethylbenzylammonium chloride, and the mixture was reacted at 85°C for 32 hours while blowing in air. In this way, (meth)acrylic resin solution 1 was obtained.

[0122] (Meth)acrylic resin emulsion 1: Using 0.5 parts by mass of ammonium peroxodisulfate as a polymerization initiator, 63 parts by mass of 2-ethylhexyl acrylate, 21 parts by mass of n-butyl acrylate, 9 parts by mass of methyl methacrylate, 3 parts by mass of 2-hydroxyethyl methacrylate, 2 parts by mass of methacrylic acid, 1 part by mass of acrylamide, 1 part by mass of polytetramethylene glycol diacrylate (manufactured by NOF Corporation, product name: Blemmer ADT-250), and 2 parts by mass of an aqueous solution of polyoxyethylene nonylpropenyl phenyl ether ammonium sulfate (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., product name: Aqualon HS-1025) were emulsion-polymerized in deionized water at 70°C for 8 hours. After completion of polymerization, the pH was adjusted to 7 with aqueous ammonia. In this way, (meth)acrylic resin emulsion 1 with a solids concentration of 56.5% was obtained.

[0123] (Meth)acrylic resin emulsion 2: Using 0.5 parts by mass of 4,4'-azobis-4-cyanovaleric acid (manufactured by Otsuka Chemical Co., Ltd., product name: ACVA) as a polymerization initiator, 74 parts by mass of butyl acrylate, 14 parts by mass of methyl methacrylate, 9 parts by mass of 2-hydroxyethyl methacrylate, 2 parts by mass of methacrylic acid, 1 part by mass of acrylamide, and 3 parts by mass of an aqueous solution of polyoxyethylene nonylpropenylphenyl ether ammonium sulfate (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., product name: Aqualon HS-1025) were emulsion-polymerized in deionized water at 70°C for 8 hours. After completion of polymerization, the pH was adjusted to 7 with aqueous ammonia. As a result, (meth)acrylic resin emulsion 2 with a solids concentration of 42.5% was obtained.

[0124] Next, layer-forming coating solutions used to form each layer of the adhesive film were prepared according to the following procedure.

[0125] Coating liquid C-1 for forming adhesive resin layer (C): 100 parts by mass of (meth)acrylic resin solution 1 (solid content concentration 45%) and 0.9 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., product name: Takenate D170N) (2 parts by mass per 100 parts by mass of adhesive resin in terms of solid content) were mixed, and then 7 parts by mass of toluene and 7 parts by mass of ethyl acetate were further mixed to obtain coating liquid C-1 for forming adhesive resin layer (C).

[0126] Adhesive resin layer (C)-forming coating liquid C-2: 100 parts by mass of the (meth)acrylic resin solution 1 (solid content concentration 45%), 2.4 parts by mass of a polymerized rosin ester-based tackifier (manufactured by Arakawa Chemical Industries, Ltd., product name: Pencel D-125) (5.3 parts by mass per 100 parts by mass of the adhesive resin in terms of solid content), 1.3 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., product name: Olester P49-75S) (2.9 parts by mass per 100 parts by mass of the adhesive resin in terms of solid content), and 7.1 parts by mass of heat-expandable microspheres (manufactured by Sekisui Chemical Co., Ltd., product name: Advancell EM-503) (15.8 parts by mass per 100 parts by mass of the adhesive resin in terms of solid content), were mixed, and then 37 parts by mass of toluene and 37 parts by mass of ethyl acetate were further mixed to obtain adhesive resin layer (C)-forming coating liquid C-2.

[0127] Coating liquid B for forming adhesive resin layer (B): 42.6 parts by mass of (meth)acrylic resin emulsion 1, 57.4 parts by mass of (meth)acrylic resin emulsion 2, 0.4 parts by mass of dimethylethanolamine, 5 parts by mass of an epoxy compound (manufactured by Nagase ChemteX Corporation, product name: EX-1610) as a crosslinking agent, 13 parts by mass of diethylene glycol monobutyl ether, and H ２ 20 parts by mass of the adhesive resin layer (B) was obtained by mixing with 20 parts by mass of the adhesive resin layer (B).

[0128] Coating liquid D for forming intermediate layer (D): Coating liquid D for forming intermediate layer (D) was prepared by mixing 100 parts by mass of the (meth)acrylic resin solution 1, 0.05 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., product name: Olester P49-75S), 1 part by mass of a thermal initiator (manufactured by Kayaku Nouryon, organic peroxide, product name: Perkadox 12-XL25), 3 parts by mass of an alkylphenone-based photoinitiator (manufactured by IGM Resins B.V., 2-benzyl-2-(dimethylamino)-4′-morpholinobutyrophenone, product name: Omnirad 369), and 5 parts by mass of a polyfunctional acrylic oligomer (manufactured by Toagosei Co., Ltd., product name: Aronix M400).

[0129] <Preparation of adhesive film> [Example 1] First, the adhesive resin layer (C) forming coating liquid C-1 was coated on a silicone release-treated separator and dried at 120 ° C for 3 minutes to form a resin film. Then, this resin film was attached to the second surface of a polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name: Lumirror S10, thickness: 38 μm, double-sided corona treated product) which was the base layer (A) to form a resin layer. Similarly, the adhesive resin layer (C) forming coating liquid C-2 was coated on the separator and dried at 120 ° C for 3 minutes to form a resin film. Then, this resin film was laminated on the above-mentioned resin layer to form a two-layer adhesive resin layer (C). Next, similarly, the intermediate layer (D) forming coating liquid D was coated on the separator and dried at 100 ° C for 3 minutes to form a resin film. This resin film was attached to the first surface of the base layer (A) (the surface opposite to the surface on which the adhesive resin layer (C) was provided). This resulted in an intermediate layer (D) (thickness: 40 μm). Next, the adhesive resin layer (B) forming coating liquid B was applied to a separator and dried at 120° C. for 3 minutes to form a resin film. This resin film was laminated on the intermediate layer (D) to form an adhesive resin layer (B) (thickness: 6 μm). As a result, an adhesive film was obtained that included the substrate layer (A), the adhesive resin layer (B) provided on the first surface side of the substrate layer (A), the adhesive resin layer (C) provided on the second surface side of the substrate layer, and the intermediate layer (D) provided between the substrate layer (A) and the adhesive resin layer (B).

[0130] Comparative Example 1 A pressure-sensitive adhesive film was obtained in the same manner as in Example 1, except that the intermediate layer (D) was not formed.

[0131] <Evaluation> Measurement of storage modulus E' of intermediate layer (D) at 125°C: Using the coating solution D for forming the intermediate layer (D) used in the examples and comparative examples, an intermediate layer (D) having a thickness of 40 µm was prepared separately from the adhesive film. Next, the intermediate layer (D) was laminated to obtain a sample having a thickness of 1 mm. Next, the obtained sample was irradiated with a UV irradiator (Ushio Inc., product name: UVX-02528S1AJA02) at an irradiation intensity of 1080 mJ / cm ２The intermediate layer (D) was then irradiated with UV light having a wavelength of 300 to 600 nm under the following conditions: Next, the intermediate layer (D) was crosslinked (cured) at 130°C for 30 minutes. The storage modulus E' of the cured sample at 125°C was then measured using a solid viscoelasticity measuring device (RSA-3, manufactured by TA Instruments) under the following conditions: measurement temperature 125°C, frequency 1 Hz, heating rate 5°C / min, strain fixed mode with a strain of 0.05%, chuck distance 20 mm, and sample width 10 mm, and was found to be 8.4 x 10 ６ It was Pa.

[0132] Evaluation of bubbles: First, the adhesive resin layer (C) side of the adhesive film obtained by the above method was attached to a glass plate (diameter: 300 mm, thickness: 1.5 mm) and pressed under the conditions of a press temperature of 24 ° C, a press pressure of 0.75 MPa (cylinder pressure), a press time of 60 seconds, and a vacuum degree of 25 Pa. Next, the adhesive resin layer (B) side of the adhesive film was attached to a glass plate (diameter: 300 mm, thickness: 1.5 mm) and pressed under the conditions of a press temperature of 24 ° C, a press pressure of 0.75 MPa (cylinder pressure), a press time of 60 seconds, and a vacuum degree of 25 Pa. Next, the adhesive film was visually observed from the adhesive resin layer (B) side of the adhesive film. As a result, when the adhesive sheet of Example 1 was used, no bubbles were observed between the glass plate and the adhesive film. On the other hand, when the adhesive sheet of Comparative Example 1 was used, bubbles were observed between the glass plate and the adhesive film.

[0133] The above results show that the method for manufacturing an electronic component according to this embodiment can suppress the generation of bubbles that occur when an adhesive film is attached to an electronic component and a supporting substrate.

[0134] This application claims priority based on Japanese Patent Application No. 2024-018602, filed February 9, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0135] A: Base material layer (A) B: Adhesive resin layer (B) C: Adhesive resin layer (C) D: Intermediate layer (D) A1: First surface of base material layer (A) A2: Second surface of base material layer (A) A10: Circuit formation surface 10: Electronic component 20: Support substrate 100: Adhesive film

Claims

1. A method for manufacturing an electronic component, comprising the step (a) of backgrinding an electronic component temporarily fixed to a support substrate via an adhesive film, wherein the adhesive film comprises: a base layer (A); an adhesive resin layer (B) for temporarily fixing the electronic component on a first surface side of the base layer (A); and an adhesive resin layer (C) for temporarily fixing a support substrate on a second surface side of the base layer (A); and an intermediate layer (D) in at least one selected from between the base layer (A) and the adhesive resin layer (B) and between the base layer (A) and the adhesive resin layer (C), wherein at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) comprises a layer whose adhesive strength is reduced by an external stimulus, and the method for manufacturing an electronic component further comprises the step (b) of reducing the adhesive strength of at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) by an external stimulus.

2. The method for producing an electronic component according to claim 1, wherein at least one selected from the adhesive resin layer (B) and the adhesive resin layer (C) comprises one or more selected from the group consisting of a heat-peelable adhesive resin layer and a light-peelable adhesive resin layer.

3. The method for manufacturing an electronic component according to claim 2, wherein the heat-peelable adhesive resin layer includes an adhesive resin layer whose adhesive strength is reduced or lost when heated at a temperature exceeding 100°C.

4. A method for producing an electronic component according to any one of claims 1 to 3, wherein the adhesive resin (C1) constituting the adhesive resin layer (C) comprises one or more resins selected from the group consisting of (meth)acrylic resins, urethane resins, silicone resins, polyolefin resins, polyester resins, polyamide resins, fluorine resins and styrene-diene block copolymer resins.

5. The method for producing an electronic component according to any one of claims 1 to 4, wherein the thickness of the adhesive resin layer (C) is 1 μm or more and 500 μm or less.

6. A method for manufacturing an electronic component according to any one of claims 1 to 5, wherein the adhesive resin constituting the adhesive resin layer (B) comprises one or more types selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins.

7. The method for producing an electronic component according to any one of claims 1 to 6, wherein the thickness of the adhesive resin layer (B) is 1 μm or more and 500 μm or less.

8. The method for producing an electronic component according to any one of claims 1 to 7, wherein the intermediate layer (D) includes a layer that hardens in response to an external stimulus.

9. The method for producing an electronic component according to any one of claims 1 to 8, wherein the intermediate layer (D) contains a crosslinking agent.

10. The method for producing an electronic component according to claim 9, wherein the crosslinking agent comprises one or more compounds selected from the group consisting of polyfunctional (meth)acrylate compounds and isocyanate compounds.

11. The method for producing an electronic component according to any one of claims 1 to 10, wherein the intermediate layer (D) contains one or more types selected from the group consisting of thermal initiators and photoinitiators.

12. The method for producing an electronic component according to claim 11, wherein the thermal initiator comprises one or more compounds selected from the group consisting of aromatic ketones, onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and azo compounds.

13. The method for producing an electronic component according to claim 11 or 12, wherein the photoinitiator comprises an alkylphenone-based photoinitiator.

14. The storage modulus E' at 125°C of the intermediate layer (D') obtained by crosslinking the intermediate layer (D) is 1.0 x 10 ６ Pa or more 1.0×10 ９ The method for manufacturing an electronic component according to any one of claims 1 to 13, wherein the temperature is 1000 KPa or less.

15. The method for manufacturing an electronic component according to any one of claims 1 to 14, wherein the thickness of the intermediate layer (D) is 5 μm or more and 1000 μm or less.

16. The method for producing an electronic component according to any one of claims 1 to 15, wherein the substrate layer (A) contains a thermoplastic resin.

17. The method for producing an electronic component according to any one of claims 1 to 16, wherein the thickness of the substrate layer (A) is 1 μm or more and 500 μm or less.

18. The method for manufacturing an electronic component according to any one of claims 1 to 17, wherein the electronic component comprises a semiconductor wafer.

19. The method for producing an electronic component according to claim 18, wherein the semiconductor wafer comprises a sapphire wafer, an indium-phosphorus wafer, a silicon-carbon wafer, a gallium-nitrogen wafer, a gallium-arsenide wafer, a silicon wafer, a germanium wafer, a germanium-arsenide wafer, a gallium-phosphorus wafer, a gallium-arsenide-aluminum wafer, or a lithium tantalate wafer.

20. The method for manufacturing an electronic component according to any one of claims 1 to 19, wherein the electronic component includes a circuit formation surface.

21. The method for producing an electronic component according to any one of claims 1 to 20, wherein in step (a), the electronic component is back-ground to reduce the thickness of the electronic component to 100 μm or less.

22. The method for producing an electronic component according to any one of claims 1 to 21, further comprising a step (c) of treating the surface of the electronic component opposite to the adhesive film side in a vacuum atmosphere.

23. The method for producing an electronic component according to claim 22, wherein step (c) includes at least one step selected from the group consisting of an ion implantation step, a metal film formation step, and an annealing treatment step.

24. The method for producing an electronic component according to any one of claims 1 to 23, further comprising a step (d) of curing the intermediate layer (D) by an external stimulus.

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