Adhesive film

Abstract

An adhesive film (10) comprising a substrate layer (A) and an adhesive resin layer (B), wherein the arithmetic average roughness Ra according to a prescribed method is 12-100 μm.

Description

Adhesive Film

[0001] The present invention relates to an adhesive film.

[0002] In the manufacturing process of electronic devices, there is a step of dicing an electronic component such as a semiconductor substrate into a plurality of electronic components. In this dicing step, for example, the electronic component is diced to obtain a plurality of electronic components while the electronic component is attached onto a pressure-sensitive adhesive film (PSA film) (hereinafter also referred to as an adhesive film). Examples of the technology related to adhesive films used in such dicing steps include the technology described in Patent Document 1.

[0003] Patent Document 1 addresses the problem of providing a dicing tape and a dicing die-bonding film (DDAF) that are suitable for increasing the separation distance while suppressing lifting of the divided semiconductor chips with die-bonding film (DAF) on the dicing tape from the dicing tape in the expanding step performed using DDAF to obtain semiconductor chips with die-bonding film (DAF), and are also suitable for achieving good pick-up performance in the pick-up step. The dicing tape described therein has a laminated structure including a base material and an adhesive layer, wherein the value of the ratio of a second tensile stress generated at a strain value of 20% in a tensile test performed on a 20 mm-wide dicing tape test piece under the conditions of an initial chuck distance of 100 mm, 23°C, and a tensile speed of 1000 mm / min to a first tensile stress generated at a strain value of 20% in a tensile test performed on the 20 mm-wide dicing tape test piece under the conditions of an initial chuck distance of 100 mm, 23°C, and a tensile speed of 10 mm / min is 1.4 or more.

[0004] Japanese Unexamined Patent Application Publication No. 2019-16634

[0005] The present invention provides an adhesive film capable of reducing the time required for debonding.

[0006] Conventional adhesive films described in Patent Document 1 and others were designed based on the guideline of controlling the tensile properties of the adhesive film, in order to be suitable for increasing the separation distance while suppressing lifting and to achieve good pick-up performance in the pick-up process. In contrast, the present inventors, in order to solve the problem of reducing the time required for debonding, investigated and discovered that the arithmetic mean roughness after heating the adhesive film by a predetermined method affects the time required for debonding, and thus completed the present invention.

[0007] According to the present invention, the following adhesive film is provided.

[0008] [1] An adhesive film comprising a base layer (A) and an adhesive resin layer (B), wherein the arithmetic mean roughness Ra according to Method 1 below is 12 μm or more and 100 μm or less. (Method 1) A structure 1 is fabricated by fixing the surface of the adhesive film on the base layer (A) side to a silicon wafer, and left to stand at a temperature of 23°C, a humidity of 50 ± 5% RH for 1 hour. Next, the structure 1 is placed on the hot plate with the silicon wafer facing the hot plate, and the structure 1 is heated using the hot plate at 150°C for 60 seconds in an air atmosphere. Next, the arithmetic mean roughness Ra of the surface of the adhesive film on the adhesive resin layer (B) side is measured in accordance with JIS B 0601:2013. [2] The adhesive film according to [1] above, wherein the peel strength according to Method 2 below is 3.0 N / 25 mm or less. (Method 2) The side of the adhesive film facing the adhesive resin layer (B) is attached to a silicon wafer under the conditions of a temperature of 23°C, a humidity of 50±5%RH, an attachment speed of 10 mm / second, and a pressure of 0.4 MPa, and left to stand for 1 hour under the conditions of a temperature of 23°C, a humidity of 50±5%RH. Then, the adhesive film is peeled from the silicon wafer under the conditions of a temperature of 23°C, a humidity of 50±5%RH, a peel angle of 180°, and a tensile speed of 300 mm / min to measure the 180° peel strength. [3] The adhesive film according to [1] or [2] above, wherein the adhesive resin layer (B) contains thermally expandable microspheres. [4] The adhesive film according to [3], wherein the adhesive resin layer (B) is a layer formed from an adhesive resin composition containing an adhesive resin, the adhesive resin composition further contains the thermally expandable microspheres, and the content of the thermally expandable microspheres in the adhesive resin composition is 1.0 part by mass or more and 100 parts by mass or less, when the content of the adhesive resin in the adhesive resin composition is 100 parts by mass. [5] The adhesive film according to any one of [1] to [4], wherein the adhesive resin layer (B) is a layer formed from an adhesive resin composition containing an adhesive resin, the adhesive resin composition further contains a crosslinking agent. [6] The adhesive film according to [5], wherein the content of the crosslinking agent in the adhesive resin composition is 1.0 part by mass or more and 50 parts by mass or less, when the content of the adhesive resin in the adhesive resin composition is 100 parts by mass.[7] The adhesive film according to any one of [1] to [6] above, wherein the thickness of the adhesive resin layer (B) is 0.1 μm or more and 50 μm or less. [8] The adhesive film according to any one of [1] to [7] above, further comprising an intermediate layer (C) between the base layer (A) and the adhesive resin layer (B). [9] The adhesive film according to [8] above, wherein the thickness of the intermediate layer (C) is 0.1 μm or more and 50 μm or less.

[10] The adhesive film according to any one of [1] to [9] above, wherein the adhesive resin layer (B) is a layer whose adhesive strength decreases by heat treatment.

[11] The adhesive film according to any one of [1] to

[10] above, wherein the adhesive resin layer (B) includes one or more selected from the group consisting of (meth)acrylic adhesive resin, silicone adhesive resin, urethane adhesive resin, olefin adhesive resin, and styrene adhesive resin.

[12] The adhesive film according to any one of [1] to

[11] above, wherein the base material layer (A) comprises one or more selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyamide, polyimide, and polyetheretherketone.

[13] The adhesive film according to any one of [1] to

[12] above, wherein the base material layer (A) comprises one or more selected from the group consisting of dicing tape, tape for temporary fixing of electronic components, tape for substrate processing, backgrind tape, and surface protection tape.

[0009] According to the present invention, an adhesive film can be provided that can reduce the time required for debonding.

[0010] This is a schematic cross-sectional view showing an example of the structure of the adhesive film of this embodiment. This is a schematic cross-sectional view showing an example of the manufacturing method of the electronic device of this embodiment. This is a schematic cross-sectional view showing an example of the manufacturing method of the electronic device of this embodiment. This is a schematic cross-sectional view showing an example of the manufacturing method of the electronic device of this embodiment.

[0011] In this specification, the term "(meth)acrylate" encompasses both acrylate and methacrylate. The same applies to similar terms such as "(meth)acrylic." For each component described in this specification, one type may be used, or two or more types may be used in combination. The "~" symbol indicating a numerical range represents "greater than or equal to" and "less than or equal to," including both the upper and lower limits. To avoid complexity, if there are multiple identical components in the same drawing, only one may be assigned a reference numeral, and none of them may be assigned a reference numeral. Drawings are for illustrative purposes only. The shapes and dimensional ratios of each component in the drawings do not necessarily correspond to actual articles.

[0012] <Adhesive Film> The adhesive film of this embodiment comprises a base layer (A) and an adhesive resin layer (B) (hereinafter also referred to as the adhesive layer (B)). In the adhesive film of this embodiment, the arithmetic mean roughness Ra measured by the following method 1 is 12 μm or more and 100 μm or less. (Method 1) A structure 1 is fabricated by fixing the surface of the adhesive film with the base layer (A) to a silicon wafer, and left to stand at a temperature of 23°C, a humidity of 50 ± 5% RH, for 1 hour. Next, the structure 1 is placed on a hot plate with the silicon wafer facing the hot plate, and the structure 1 is heated using the hot plate at 150°C for 60 seconds under air conditions. Next, the arithmetic mean roughness Ra of the surface of the adhesive film with the adhesive layer (B) is measured in accordance with JIS B 0601:2013. The adhesive film of this embodiment, having the above configuration, can reduce the time required for debonding (hereinafter also referred to as the debonding time).

[0013] The reason for this is not entirely clear, but the following reasons can be inferred. In this embodiment, the arithmetic mean roughness Ra obtained by method 1 is within the above numerical range, which is thought to allow for a large increase in surface irregularities of the adhesive layer (B) during debonding in a short time. As a result, it is thought that the debonding time can be reduced with this embodiment.

[0014] First, the layer structure of the adhesive film of this embodiment will be described. Figure 1 is a schematic cross-sectional view showing an example of the structure of an adhesive film (adhesive film 10) according to an embodiment of the present invention. The adhesive film 10 comprises a base layer (A), an intermediate layer (C), and an adhesive layer (B) in this order.

[0015] In the adhesive film of this embodiment, the sum of the thicknesses of the base layer (A) and the adhesive layer (B) is preferably 10 μm or more and 2000 μm or less, more preferably 15 μm or more and 1000 μm or less, even more preferably 20 μm or more and 500 μm or less, even more preferably 25 μm or more and 100 μm or less, even more preferably 30 μm or more and 80 μm or less, even more preferably 35 μm or more and 75 μm or less, even more preferably 40 μm or more and 70 μm or less, and even more preferably 45 μm or more and 65 μm or less, from the viewpoint of improving the balance between mechanical properties and handling ease.

[0016] In the adhesive film of this embodiment, the sum of the thicknesses of the adhesive layer (B) and the intermediate layer (C) is preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 80 μm or less, even more preferably 10 μm or more and 60 μm or less, even more preferably 12 μm or more and 55 μm or less, even more preferably 14 μm or more and 50 μm or less, even more preferably 16 μm or more and 45 μm or less, even more preferably 18 μm or more and 40 μm or less, and even more preferably 20 μm or more and 35 μm or less, from the viewpoint of further reducing the debonding time.

[0017] The overall thickness of the adhesive film of this embodiment is preferably 10 μm to 2000 μm, more preferably 20 μm to 1000 μm, even more preferably 30 μm to 500 μm, even more preferably 35 μm to 100 μm, even more preferably 40 μm to 80 μm, even more preferably 45 μm to 75 μm, even more preferably 50 μm to 70 μm, and even more preferably 55 μm to 65 μm, from the viewpoint of improving the balance between mechanical properties and handling ease.

[0018] Next, each layer of the adhesive film of this embodiment will be described.

[0019] (Base layer (A)) The adhesive film of this embodiment comprises a base layer (A). The base layer (A) is a layer provided for the purpose of improving the handling properties, mechanical properties, heat resistance, and other properties of the adhesive film. The base layer (A) is not particularly limited as long as it has mechanical strength that can withstand the external forces applied when processing the workpiece, but a resin film is an example.

[0020] The base layer (A) includes, for example, a thermoplastic resin. The thermoplastic resin includes, for example, one or more selected from the group consisting of polyolefins, polyesters, polyamides, poly(meth)acrylates, polyvinyl chlorides, polyvinylidene chlorides, polyimides, polyetherimides, ethylene-vinyl acetate copolymers, polyacrylonitriles, polycarbonates, polystyrenes, ionomers, polysulfones, polyethersulfones, polyphenylene ethers, and aromatic polyetherketones. The polyolefin includes, for example, one or more selected from the group consisting of polyethylene, polypropylene, poly(4-methyl-1-pentene), and poly(1-butene). The polyester includes, for example, one or more selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. The polyamide includes, for example, one or more selected from the group consisting of nylon-6, nylon-66, and polymetaxylene adipamide. Aromatic polyether ketones include, for example, one or more selected from the group consisting of polyether ketone (PEK), polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polyether ether ketone ketone (PEEKK), and polyether ketone esters.

[0021] The base layer (A) preferably contains one or more materials selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyamide, polyimide, and polyetheretherketone, and more preferably contains polyethylene terephthalate, from the viewpoint of improving the balance between mechanical properties and handling performance.

[0022] The base layer (A) may be a single layer or a multilayer of two or more layers. Furthermore, when a resin film is used for the base layer (A), the resin film is preferably a stretched film, and more preferably a film stretched uniaxially or biaxially, from the viewpoint of improving the mechanical strength of the base layer (A).

[0023] From the viewpoint of improving film properties, the thickness of the substrate layer (A) is preferably 1 μm to 500 μm, more preferably 5 μm to 400 μm, even more preferably 10 μm to 300 μm, even more preferably 20 μm to 200 μm, even more preferably 25 μm to 100 μm, even more preferably 30 μm to 50 μm, and even more preferably 35 μm to 45 μm.

[0024] The substrate layer (A) may undergo surface treatments such as corona treatment, plasma treatment, undercoat treatment, or primer coating treatment to improve its adhesion to other layers.

[0025] (Adhesive layer (B)) The adhesive film of this embodiment includes an adhesive layer (B). The adhesive layer (B) is a layer that adheres to the surface of the workpiece when the workpiece is attached to the adhesive film. The adhesive layer (B) may be a single layer or a multilayer of two or more layers.

[0026] The adhesive layer (B) is a layer formed from an adhesive resin composition containing an adhesive resin (B1). The adhesive resin composition preferably further comprises one or more selected from the group consisting of a crosslinking agent (B2), a thermally expandable microsphere (B3), and a thickener (B4). The adhesive resin composition may also further contain additives such as plasticizers as other components. The adhesive coating liquid in the example is an example of an adhesive resin composition.

[0027] The adhesive layer (B) is preferably a layer whose adhesive strength decreases with heat treatment. In this case, the adhesive resin composition forming the adhesive layer (B) preferably includes an adhesive resin (B1) and thermally expandable microspheres (B3).

[0028] Adhesive resin (B1) preferably includes one or more selected from the group consisting of (meth)acrylic adhesive resins, silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins, from the viewpoint of improving the balance between adhesive strength and heat resistance. Adhesive resin (B1) more preferably includes (meth)acrylic adhesive resin from the viewpoint of easily adjusting the adhesive strength.

[0029] The (meth)acrylic adhesive resin includes, for example, a copolymer (b) having a constituent unit (b1) of an alkyl (meth)acrylate and a constituent unit (b2) having a functional group that can react with a crosslinking agent (B2).

[0030] Copolymer (b) can be produced, for example, by copolymerizing a monomer that forms a structural unit (b1) of an alkyl (meth)acrylate (hereinafter also referred to as monomer (b1)) and a monomer that forms a structural unit (b2) having a functional group that can react with a crosslinking agent (B2) (hereinafter also referred to as monomer (b2)). Note that copolymer (b) may also have structural units other than structural units (b1) and structural unit (b2).

[0031] The monomer (b1) preferably comprises an alkyl (meth)acrylate having an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl (meth)acrylate having an alkyl group having 1 to 8 carbon atoms, and even more preferably one or more selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate.

[0032] The monomer (b2) comprises, for example, one or more selected from the group consisting of (meth)acrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, monoalkyl itaconic acid, monoalkyl mesaconic acid, monoalkyl citraconic acid, monoalkyl fumaric acid, monoalkyl maleic acid, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, (meth)acrylamide, and t-butylaminoethyl (meth)acrylate. The monomer (b2) preferably comprises one or more selected from the group consisting of (meth)acrylic acid, 2-hydroxyethyl (meth)acrylate, and (meth)acrylamide, and more preferably comprises 2-hydroxyethyl (meth)acrylate.

[0033] The polymerization method for copolymer (b) is not particularly limited, but may be radical polymerization, anionic polymerization, cationic polymerization, etc. From the viewpoint of the manufacturing cost of copolymer (b), the influence of the functional groups of the monomer, and the influence of ions on the surface of the workpiece, radical polymerization is preferred as the polymerization reaction mechanism for copolymer (b).

[0034] When copolymer (b) is synthesized by radical polymerization, the radical polymerization initiator includes, for example, one or more selected from the group consisting of organic peroxides, inorganic peroxides, and azo compounds. Organic peroxides include, for example, one or more selected from the group consisting of benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, 3,3,5-trimethylhexanoyl peroxide, di-2-ethylhexyl peroxydicarbonate, methyl ethyl ketone peroxide, t-butyl peroxyphthalate, t-butyl peroxybenzoate, di-t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-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, and di-t-amyl peroxide. Inorganic peroxides include, for example, one or more selected from the group consisting of ammonium persulfate, potassium persulfate, and sodium persulfate. The azo compound includes, for example, one or more selected from the group consisting of 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, and 4,4'-azobis-4-cyanovaleric acid.

[0035] The radical polymerization initiator used to synthesize copolymer (b) preferably contains an organic peroxide, and more preferably contains t-butylperoxy-2-ethylhexanoate, from the viewpoint of improving the balance between the adhesive strength and heat resistance of the adhesive layer (B).

[0036] From the viewpoint of improving adhesive strength, the content of the adhesive resin (B1) in the adhesive resin composition is preferably 10% to 90% by mass, more preferably 30% to 85% by mass, even more preferably 40% to 80% by mass, and even more preferably 50% to 75% by mass, when the total solid content in the adhesive resin composition is considered to be 100% by mass.

[0037] The adhesive resin composition preferably further comprises a crosslinking agent (B2). The crosslinking agent (B2) is a compound having two or more crosslinkable functional groups in one molecule. The crosslinking agent (B2) is used to react with the functional groups of the adhesive resin (B1) to adjust the tackiness and cohesiveness of the adhesive layer (B).

[0038] The crosslinking agent (B2) is not particularly limited, but may include, for example, one or more selected from the group consisting of epoxy crosslinking agents, isocyanate crosslinking agents, aziridine crosslinking agents, tetrafunctional epoxy crosslinking agents, and melamine crosslinking agents.

[0039] From the viewpoint of further reducing the debonding time, the content of the crosslinking agent (B2) in the adhesive resin composition is preferably 1.0 part by mass or more and 50 parts by mass or less, more preferably 5.0 parts by mass or more and 40 parts by mass or less, even more preferably 10 parts by mass or more and 30 parts by mass or less, and even more preferably 15 parts by mass or more and 20 parts by mass or less, when the content of the adhesive resin (B1) in the adhesive resin composition is 100 parts by mass.

[0040] The adhesive layer (B) preferably further comprises thermally expandable microspheres (B3) from the viewpoint of reducing stress on the workpiece. In this case, the adhesive resin composition further comprises thermally expandable microspheres (B3). The thermally expandable microspheres (B3) are a resin composition of tiny spherical particles that expand when heated.

[0041] The thermally expandable microsphere (B3) preferably comprises a shell and a volatile expanding agent within the shell. More preferably, the thermally expandable microsphere has a structure in which the volatile expanding agent is contained within the space inside the shell. With such a structure, for example, the shell expands when the volatile expanding agent volatilizes and turns into a gas upon heating.

[0042] The shell contains one or more selected from the group consisting of thermoplastic resins and thermosetting resins. The thermoplastic resin includes, for example, one or more selected from the group consisting of vinylidene chloride-acrylonitrile copolymers, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone. The thermosetting resin includes, for example, one or more selected from the group consisting of epoxy resins, phenolic resins, melamine resins, urea resins, polyimide resins, and bismaleimide resins.

[0043] The volatile expanding agent is, for example, a substance that becomes a gas when heated. The volatile expanding agent includes, for example, one or more selected from the group consisting of ethane, ethylene, propane, propene, n-butane, isobutane, butene, isobutene, n-pentane, isopentane, neopentane, n-hexane, heptane, and petroleum ether.

[0044] The expansion temperature of the heat-expandable microspheres (B3) is preferably 100°C or higher and 150°C or lower, more preferably 110°C or higher and 140°C or lower, and still more preferably 115°C or higher and 130°C or lower, from the viewpoint of facilitating formation of the adhesive layer (B) containing the heat-expandable microspheres (B3).

[0045] The content of the heat-expandable microspheres (B3) in the adhesive resin composition, when the content of the adhesive resin (B1) in the adhesive resin composition is 100 parts by mass, is preferably 1.0 part by mass or more and 100 parts by mass or less, more preferably 10 parts by mass or more and 90 parts by mass or less, still more preferably 20 parts by mass or more and 80 parts by mass or less, still more preferably 25 parts by mass or more and 70 parts by mass or less, still more preferably 30 parts by mass or more and 60 parts by mass or less, still more preferably 35 parts by mass or more and 50 parts by mass or less, and even more preferably 40 parts by mass or more and 45 parts by mass or less, from the viewpoint of further reducing debonding time.

[0046] The adhesive resin composition preferably further contains a thickener (B4) from the viewpoint of improving the adhesive strength of the adhesive layer (B).

[0047] The thickener (B4) includes, for example, one or more selected from the group consisting of rosin-based resins, terpene-based resins, natural rosin resins, petroleum resins, and coumarone-indene-based resins. The rosin-based resins include, for example, rosin-based derivatives that have undergone treatment such as esterification. Further, the terpene-based resins include, for example, one or more selected from the group consisting of α-pinene-based resins, β-pinene-based resins, dipentene-based resins, and terpene phenol-based resins. Further, the natural rosin resins include one or more selected from the group consisting of gum-based resins, wood-based resins, and tall oil-based resins. Further, the petroleum resins include, for example, resins obtained by hydrogenating, disproportionating, polymerizing, or maleating natural rosin resins.

[0048] The content of the thickener (B4) in the pressure-sensitive adhesive resin composition, when the content of the pressure-sensitive adhesive resin (B1) in the pressure-sensitive adhesive resin composition is 100 parts by mass, is preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.5 parts by mass or more and 15 parts by mass or less, still more preferably 1 part by mass or more and 10 parts by mass or less, and even more preferably 3 parts by mass or more and 7 parts by mass or less, from the viewpoint of improving adhesive strength.

[0049] The thickness of the pressure-sensitive adhesive layer (B) is preferably 50 µm or less, more preferably 40 µm or less, still more preferably 35 µm or less, even more preferably 30 µm or less, yet more preferably 25 µm or less, and even more preferably 20 µm or less, from the viewpoint of further reducing debonding time. The lower limit of the thickness of the pressure-sensitive adhesive layer (B) may be, for example, 0.1 µm or more, 0.5 µm or more, 1 µm or more, 5 µm or more, or 10 µm or more, from the viewpoint of reliably solving the problem of reducing debonding time. The thickness of the pressure-sensitive adhesive layer (B) is preferably 0.1 µm or more and 50 µm or less, more preferably 0.5 µm or more and 40 µm or less, still more preferably 1 µm or more and 35 µm or less, even more preferably 5 µm or more and 30 µm or less, yet more preferably 10 µm or more and 25 µm or less, and even more preferably 10 µm or more and 20 µm or less, from the viewpoint of further reducing debonding time.

[0050] (Intermediate layer (C)) The adhesive film of this embodiment preferably further comprises an intermediate layer (C) between the base layer (A) and the adhesive layer (B). The intermediate layer (C) is, for example, a layer provided as a surface-absorbing resin layer, an impact-absorbing layer, an anchor coat layer, etc.

[0051] The intermediate layer (C) preferably comprises a thermoplastic resin, more preferably one or more selected from the group consisting of (meth)acrylic resins, olefin resins, styrene resins, urethane resins, silicone resins, ester resins, amide resins, and fluororesins, and even more preferably one or more selected from the group consisting of (meth)acrylic resins, olefin resins, and styrene resins.

[0052] From the viewpoint of further reducing the debonding time, the thickness of the intermediate layer (C) is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, even more preferably 25 μm or less, even more preferably 20 μm or less, and even more preferably 15 μm or less. From the viewpoint of reliably solving the problem of reducing the debonding time, the lower limit of the thickness of the intermediate layer (C) may be, for example, 0.1 μm or more, 0.5 μm or more, 1 μm or more, 3 μm or more, or 5 μm or more. From the viewpoint of further reducing the debonding time, the thickness of the intermediate layer (C) is preferably 0.1 μm or more and 50 μm or less, more preferably 0.5 μm or more and 40 μm or less, even more preferably 1 μm or more and 30 μm or less, even more preferably 3 μm or more and 25 μm or less, even more preferably 5 μm or more and 20 μm or less, and even more preferably 5 μm or more and 15 μm or less.

[0053] The intermediate layer (C) may contain additives such as plasticizers as other components. Furthermore, the intermediate layer (C) may be a single layer or a multilayer structure of two or more layers.

[0054] (Other layers) The adhesive film of this embodiment may further comprise layers other than the base layer (A), the intermediate layer (C), and the adhesive layer (B). For example, the adhesive film of this embodiment may further comprise an antistatic layer on the surface of the adhesive layer (B) opposite to the base layer (A), or an antistatic layer on the surface of the base layer (A) opposite to the adhesive layer (B), or an adhesive resin layer on the surface of the base layer (A) opposite to the adhesive layer (B).

[0055] [Characteristics of the Adhesive Film] The characteristics of the adhesive film of this embodiment will be described below.

[0056] The arithmetic mean roughness Ra of the adhesive film of this embodiment, obtained by method 1 above, is 12 μm or more, preferably 13 μm or more, more preferably 15 μm or more, even more preferably 18 μm or more, even more preferably 20 μm or more, even more preferably 22 μm or more, and even more preferably 23 μm or more, from the viewpoint of reducing the debonding time. The upper limit of the arithmetic mean roughness Ra of the adhesive film of this embodiment, obtained by method 1 above, may be, for example, 100 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less, from the viewpoint of reliably solving the problem of reducing the debonding time. The arithmetic mean roughness Ra of the adhesive film of this embodiment, obtained by method 1 above, is, for example, 12 μm or more and 100 μm or less, but may also be 13 μm or more and 80 μm or less, 15 μm or more and 70 μm or less, 18 μm or more and 60 μm or less, 20 μm or more and 50 μm or less, 22 μm or more and 40 μm or less, or 23 μm or more and 30 μm or less.

[0057] More specifically, the method for measuring the arithmetic mean roughness Ra using Method 1 described above can be the method described in the Examples.

[0058] The arithmetic mean roughness Ra according to Method 1 above can be adjusted, for example, by adjusting the composition of the adhesive layer (B), the method of forming the adhesive layer (B), the thickness of the adhesive layer (B), the composition of the intermediate layer (C), the method of forming the intermediate layer (C), the thickness of the intermediate layer (C), the type of adhesive resin (B1), the type of crosslinking agent (B2), the type of thermally expandable microspheres (B3), etc. The composition of the adhesive layer (B) can also be adjusted, for example, by adjusting the blending of the adhesive resin composition used to form the adhesive layer (B), the method of forming the adhesive layer (B), etc. In this embodiment, the inventors have newly discovered a guideline that the debonding time can be reduced by adjusting the arithmetic mean roughness (arithmetic mean roughness Ra according to Method 1 above) after heating the adhesive film by a predetermined method. Therefore, the arithmetic mean roughness Ra according to Method 1 can be controlled by adjusting the factors that control the arithmetic mean roughness Ra according to Method 1 above.

[0059] The peel strength of the adhesive film of this embodiment by method 2 below is preferably 3.0 N / 25 mm or less, more preferably 2.8 N / 25 mm or less, even more preferably 2.6 N / 25 mm or less, even more preferably 2.4 N / 25 mm or less, even more preferably 2.0 N / 25 mm or less, even more preferably 1.9 N / 25 mm or less, even more preferably 1.8 N / 25 mm or less, even more preferably 1.7 N / 25 mm or less, even more preferably 1.6 N / 25 mm or less, and even more preferably 1.5 N / 25 mm or less. The lower limit of the peel strength of the adhesive film of this embodiment by method 2 below is, for example, 0.001 N / 25 mm or more, 0.01 N / 25 mm or more, 0.1 N / 25 mm or more, or 0.5 N / 25 mm or more, from the viewpoint of reliably solving the problem of reducing the debonding time. The peel strength of the adhesive film of this embodiment by method 2 below is preferably 0.001 N / 25 mm or more and 3.0 N / 25 mm or less, more preferably 0.001 N / 25 mm or more and 2.8 N / 25 mm or less, even more preferably 0.001 N / 25 mm or more and 2.6 N / 25 mm or less, even more preferably 0.01 N / 25 mm or more and 2.4 N / 25 mm or less, and even more preferably 0 The N / 25 mm is 0.01 N / 25 mm or more and 2.0 N / 25 mm or less, more preferably 0.01 N / 25 mm or more and 1.9 N / 25 mm or less, more preferably 0.1 N / 25 mm or more and 1.8 N / 25 mm or less, more preferably 0.1 N / 25 mm or more and 1.7 N / 25 mm or less, more preferably 0.1 N / 25 mm or more and 1.6 N / 25 mm or less, and more preferably 0.5 N / 25 mm or more and 1.5 N / 25 mm or less.

[0060] (Method 2) The adhesive layer (B) side of the adhesive film is attached to a silicon wafer under the conditions of a temperature of 23°C, humidity of 50±5%RH, application speed of 10 mm / second, and pressure of 0.4 MPa, and left to stand for 1 hour at a temperature of 23°C and humidity of 50±5%RH. Then, the adhesive film is peeled from the silicon wafer under the conditions of a temperature of 23°C, humidity of 50±5%RH, peel angle of 180°, and tensile speed of 300 mm / min, and the 180° peel strength is measured.

[0061] More specifically, the method for measuring peel strength using Method 2 described above can be the method described in the Examples.

[0062] The peel strength obtained by method 2 described above can be adjusted, for example, by adjusting the composition of the adhesive layer (B), the method of forming the adhesive layer (B), the thickness of the adhesive layer (B), the composition of the intermediate layer (C), the method of forming the intermediate layer (C), the thickness of the intermediate layer (C), the type of adhesive resin (B1), the type of crosslinking agent (B2), the type of thermally expandable microspheres (B3), etc. The composition of the adhesive layer (B) can be adjusted, for example, by adjusting the blending of the adhesive resin composition used to form the adhesive layer (B), the method of forming the adhesive layer (B), etc.

[0063] The debonding time of the adhesive film of this embodiment by method 3 below is preferably 3.0 s or less, more preferably 2.5 s or less, even more preferably 2.0 s or less, and even more preferably 1.5 s or less, from the viewpoint of further reducing the debonding time. The lower limit of the debonding time of the adhesive film of this embodiment by method 3 below is not particularly limited, but may be, for example, 0.1 s or more, or 0.5 s or more. The debonding time of the adhesive film of this embodiment by method 3 below is preferably 0.1 s or more and 3.0 s or less, more preferably 0.1 s or more and 2.5 s or less, even more preferably 0.5 s or more and 2.0 s or less, and even more preferably 0.5 s or more and 1.5 s or less, from the viewpoint of further reducing the debonding time.

[0064] (Method 3) Structure 3 is fabricated by attaching the adhesive layer (B) side of the adhesive film to a silicon wafer under the following conditions: temperature 23°C, humidity 50±5%RH, bonding speed 10 mm / second, and pressure 0.4 MPa. Next, structure 3 is left to stand at 23°C, humidity 50±5%RH for 1 hour. Then, structure 3 is placed on a 150°C hot plate with the silicon wafer facing the hot plate side, and the time from when structure 3 is placed on the hot plate until the entire adhesive film is debonded is measured and defined as the debonding time.

[0065] More specifically, the method for measuring the debonding time using method 3 described above can be the method described in the examples.

[0066] The debonding time according to method 3 described above can be adjusted, for example, by adjusting the composition of the adhesive layer (B), the method of forming the adhesive layer (B), the thickness of the adhesive layer (B), the composition of the intermediate layer (C), the method of forming the intermediate layer (C), the thickness of the intermediate layer (C), the type of adhesive resin (B1), the type of crosslinking agent (B2), the type of thermally expandable microspheres (B3), etc. The composition of the adhesive layer (B) can be adjusted, for example, by adjusting the blending of the adhesive resin composition used to form the adhesive layer (B), the method of forming the adhesive layer (B), etc.

[0067] [Method for Manufacturing Adhesive Film] Next, an example of a method for manufacturing the adhesive film 10 of this embodiment will be described. The adhesive film 10 of this embodiment can be manufactured, for example, by applying an intermediate layer (C) on a base layer (A), and then applying an adhesive layer (B) on top of the intermediate layer (C).

[0068] Methods for applying an adhesive layer (B) onto an intermediate layer (C) include, for example, applying an adhesive coating liquid containing an adhesive resin composition capable of forming an adhesive layer (B), or transferring an adhesive layer (B) formed on a separator onto an intermediate layer (C). Similarly, an intermediate layer (C) can be applied onto a substrate layer (A) using the same method.

[0069] Methods for applying the adhesive coating solution include, for example, the roll coater method, the reverse roll coater method, the gravure roll method, the bar coat method, the comma coater method, and the die coater method. The drying conditions for the adhesive coating solution are not particularly limited, but preferably they are dried at a temperature range of 80 to 200°C for 10 seconds to 10 minutes, and more preferably at a temperature range of 80 to 170°C for 15 seconds to 5 minutes. In order to sufficiently promote the crosslinking reaction between the adhesive resin (B1) and the crosslinking agent (B2), the adhesive coating solution may be further heated at a temperature range of 40 to 80°C for 5 to 300 hours after the drying of the adhesive coating solution is complete.

[0070] Furthermore, the adhesive film 10 of this embodiment may be manufactured by laminating a base layer (A), an intermediate layer (C), and an adhesive layer (B) in this order. Alternatively, the adhesive film 10 of this embodiment may be manufactured by co-extruding a base layer (A), an intermediate layer (C), and an adhesive layer (B) in this order.

[0071] [Applications of the Adhesive Film] The adhesive film of this embodiment can reduce debonding time, and therefore its applications are not particularly limited. The adhesive film of this embodiment can be used when processing various materials.

[0072] In this embodiment, the object to be processed is an object that is processed while temporarily fixed to an adhesive film. The object to be processed includes, for example, one or more selected from the group consisting of electronic components and substrates. Electronic components include, for example, one or more selected from the group consisting of semiconductor memories such as DRAM and SRAM; semiconductor chips such as ICs, LSIs, discrete components, light-emitting diodes, and photodetectors; semiconductor panels; semiconductor packages such as fan-out type packages; ceramic capacitors; electrical elements such as oscillators; display devices; thermal heads; and solar cells. Substrates include, for example, one or more selected from the group consisting of semiconductor substrates; package substrates in which multiple semiconductor chips are collectively sealed with sealing resin, such as mold array package substrates, fan-out type package substrates, and wafer-level package substrates; printed circuit boards (multilayer ceramic sheets); green sheets for multilayer ceramic capacitors; and thin glass substrates. Semiconductor substrates include semiconductor substrates such as silicon substrates, germanium substrates, and gallium-arsenide substrates; and semiconductor substrates on which circuits are formed on the surface or inside.

[0073] The adhesive film of this embodiment is preferably one or more selected from the group consisting of dicing tape, tape for temporarily fixing electronic components, tape for substrate processing, backgrind tape, and surface protection tape, more preferably a dicing tape, and even more preferably a dicing tape used for dicing semiconductor substrates for HBM (High Bandwidth Memory).

[0074] The semiconductor substrate for HBM preferably includes through-electrodes. The through-electrodes may be, for example, through-silicon vias (TSVs). The semiconductor substrate for HBM is, for example, a silicon wafer on which a plurality of TSVs and a plurality of DRAM circuits are formed.

[0075] <Method for Manufacturing Electronic Devices> The following describes a method for manufacturing electronic devices using the adhesive film of this embodiment.

[0076] The manufacturing method of the electronic device of this embodiment comprises the following two steps: (1) A preparation step (P) to prepare a structure X including the adhesive film of this embodiment and a workpiece temporarily fixed to the adhesive layer (B) of the adhesive film of this embodiment; (2) A processing step (R) to process the workpiece temporarily fixed to the adhesive film of this embodiment.

[0077] As mentioned above, the adhesive film of this embodiment has an arithmetic mean roughness Ra of 12 μm or more, as determined by the above method 1.

[0078] As described above, the adhesive film of this embodiment can reduce the debonding time. Therefore, the manufacturing method of the electronic device of this embodiment using the adhesive film of this embodiment can reduce the debonding time.

[0079] The following describes in detail each step of the manufacturing method for the electronic device of this embodiment, using the method for manufacturing a laminate of electronic components from an HBM semiconductor substrate (hereinafter also referred to as manufacturing method 1) as an example, with reference to Figures 2 to 4. Figure 2 is a schematic diagram showing the preparation step (P), film formation step (Q), and processing step (R), which will be described later. Figure 3 is a schematic diagram showing the expansion step (S), heating step (T), and pickup step (U), which will be described later. Figure 4 is a schematic diagram showing the lamination step (V), which will be described later.

[0080] (Preparation Step (P)) Manufacturing method 1 includes a preparation step (P). In the preparation step (P), a structure X is prepared, which includes an adhesive film 10 and a semiconductor substrate 20 temporarily fixed to the adhesive layer (B) of the adhesive film 10. The structure X is temporarily fixed to a support member (not shown) by a dicing ring 90.

[0081] In manufacturing method 1, the semiconductor substrate 20 is an HBM semiconductor substrate. The semiconductor substrate 20 is a silicon wafer 21 having a plurality of through electrodes 22 and a plurality of DRAM circuits (not shown). The through electrodes 22 penetrate the silicon wafer 21 between the surface of the silicon wafer 21 on the pad 24 side and the surface of the silicon wafer 21 on the pad 25 side. One end of the through electrode 22 is connected to a pad 24 located on the surface of the silicon wafer 21. Multiple through electrodes 22 are each connected to different pads 24. Bumps 23 are located on each of the multiple pads 24 located on the surface of the silicon wafer 21. The other end of the through electrode 22 is connected to a pad 25 located on the surface of the silicon wafer 21 opposite to the surface where the pads 24 are located. Multiple through electrodes 22 are each connected to different pads 25.

[0082] Structure X can be manufactured, for example, by the following procedure: The adhesive film 10 is placed on the support member so that the base material layer (A) side is in contact with the support member. Next, the adhesive film 10 is fixed to the support member by the dicing ring 90. Then, the side of the silicon wafer 21 on the pad 25 side of the semiconductor substrate 20 is attached to the adhesive layer (B) of the adhesive film 10 located on the support member.

[0083] The temperature at which the semiconductor substrate 20 is attached to the adhesive film 10 is not particularly limited, but is, for example, 25°C to 80°C. The pressure at which the semiconductor substrate 20 is attached to the adhesive film 10 is also not particularly limited, but is, for example, 0.3 MPa to 0.5 MPa.

[0084] (Processing step (R)) Manufacturing method 1 includes a processing step (R) after the preparation step (P). The processing step (R) is preferably performed after the film formation step (Q), which will be described later. In the processing step (R), the object to be processed, which is temporarily fixed to the adhesive film 10, is processed. The content of the processing applied to the object to be processed is not particularly limited.

[0085] The processing step (R) of manufacturing method 1 preferably includes a dicing step of dicing the workpiece. In this case, the adhesive film 10 is preferably a dicing tape. In this case, the workpiece preferably includes a substrate, and more preferably includes a semiconductor substrate 20. In this case, the semiconductor substrate 20 preferably includes through electrodes 22. In this case, the semiconductor substrate 20 preferably has a functional film 30 on at least one surface. In this case, manufacturing method 1 preferably further includes a film formation step (Q) described later.

[0086] In the dicing process, the semiconductor substrate 20, which is temporarily fixed to the adhesive film 10, is diced. The method for dicing the semiconductor substrate 20 is not particularly limited, but is one or more selected from the group consisting of, for example, blade dicing, ablation dicing, and stealth dicing. Stealth dicing includes, for example, one or more selected from the group consisting of normal stealth dicing, half-cut stealth dicing, and full-cut stealth dicing. The method for dicing the semiconductor substrate 20 is preferably the SDTT (Steel Dicing Through Tape) method. The dicing conditions can be appropriately adjusted according to the dicing method and the configuration of the semiconductor substrate 20. In the dicing process, after forming cracks in the semiconductor substrate 20 with a laser, the semiconductor substrate 20 may be divided into electronic components 40 (e.g., memory dies) by expanding the adhesive film 10 in the expansion process (S) described later. Alternatively, the semiconductor substrate 20 may be cut during the dicing process to separate the electronic components 40 from the semiconductor substrate 20.

[0087] Manufacturing method 1 may further include steps other than the preparation step (P) and the processing step (R), if necessary. The manufacturing method of the electronic device of this embodiment further includes, as other steps, one or more selected from the group consisting of, for example, a film formation step (Q), an expansion step (S), a heating step (T), a pickup step (U), and a lamination step (V).

[0088] (Film Formation Step (Q)) The manufacturing method 1 preferably further comprises a film formation step (Q) between the preparation step (P) and the processing step (R) (dicing step). In the film formation step (Q), a functional film 30 is formed on the surface of the semiconductor substrate 20 on the side where the bumps 23 and pads 24 are located. The functional film 30 covers the bumps 23 and pads 24.

[0089] The type of functional film 30 is not particularly limited. The functional film 30 includes, for example, one or more selected from the group consisting of non-conductive films, conductive films, surface protective films, and adhesive films. Preferably, the functional film 30 includes one or more selected from the group consisting of non-conductive adhesive films and conductive adhesive films.

[0090] The method for forming the functional film 30 is not particularly limited. The functional film 30 can be formed, for example, by laminating a resin film for forming the functional film 30 onto a semiconductor substrate 20. The lamination temperature is, for example, 70°C to 90°C. The thickness of the functional film 30 is, for example, 1 μm to 100 μm.

[0091] (Expanding step (S)) The manufacturing method 1 preferably further comprises an expanding step (S) simultaneously with or after the processing step (R). In the expanding step (S), the area in the adhesive layer (B) where the workpiece (semiconductor substrate 20) is temporarily fixed is expanded in the in-plane direction of the adhesive film 10 to increase the spacing between adjacent processed workpieces (electronic components 40). The method of expanding the adhesive film 10 is not particularly limited. For example, the adhesive film 10 can be expanded in the in-plane direction by using a push-up member (not shown) to push up the area of ​​the adhesive film 10 located between the outer periphery of the semiconductor substrate 20 and the inner periphery of the dicing ring 90 from the lower side in Figure 3.

[0092] (Heating step (T)) The manufacturing method 1 preferably further comprises a heating step (T) after the processing step (R). The heating step (T) is more preferably performed after the expanding step (S). In the heating step (T), the structure X is heated. By heating the structure X, the adhesive strength of the adhesive layer (B) is reduced, making it easier to pick up the electronic component 40 from the adhesive film 10. Specifically, the adhesive film 10 on the underside of the electronic component 40 to be picked up in the pickup step (U) described later is heated to expand the thermally expandable microspheres (B3) in the adhesive layer (B), thereby reducing the contact area between the electronic component 40 to be picked up and the adhesive film 10. As a result, the adhesive strength of the adhesive film 10 to the electronic component 40 to be picked up is reduced.

[0093] The heating method for structure X is not particularly limited, but examples include heating by a heater such as an oven, hot plate, or electric heater; dielectric heating; magnetic heating; and heating by electromagnetic waves (near-infrared, mid-infrared, far-infrared, etc.). The heating temperature is not particularly limited, but for example, it is above the foaming temperature of the thermally expandable microsphere (B3). The heating temperature is preferably 130°C to 180°C, more preferably 135°C to 170°C, and even more preferably 140°C to 160°C.

[0094] (Pickup step (U)) The manufacturing method 1 preferably further comprises a pickup step (U) after the processing step (R). The pickup step (U) is more preferably performed simultaneously with or after the heating step (T), and even more preferably simultaneously with the heating step (T). In the pickup step (U), the processed workpiece (electronic component 40) is picked up from the adhesive film 10. The method of picking up the electronic component 40 is not particularly limited. For example, the electronic component 40 can be picked up from the adhesive film 10 by using a pin member (not shown) to push up the adhesive film 10 on the lower side of the electronic component 40 to be picked up from the lower side in Figure 3. Alternatively, the heating step (T) and the pickup step (U) may be performed simultaneously by pushing up the adhesive film 10 on the lower side of the electronic component 40 to be picked up while heating the pin member.

[0095] (Lamination Process (V)) The manufacturing method 1 preferably further comprises a lamination process (V) after the processing process (R). The lamination process (V) is more preferably performed after the pickup process (U). In the lamination process (V), a plurality of electronic components 40 are stacked to form a laminate 50. Specifically, the plurality of electronic components 40 are stacked and heated and pressed together to fuse the bumps 23 of the upper electronic component 40 with the pads 25 of the lower electronic component 40, thereby forming the laminate 50. The heating and pressing conditions can be appropriately adjusted according to the configuration of the electronic components 40, the type of functional film 30, etc.

[0096] Although embodiments of the present invention have been described above, these are merely examples, and various other configurations can be adopted. Furthermore, the present invention is not limited to the embodiments described above, and modifications, improvements, etc., that do not impair the effects of the present invention are included in the present invention.

[0097] This embodiment will be described in detail below with reference to examples and other relevant information. However, this embodiment is not limited in any way to the descriptions of these examples.

[0098] The details of the materials used to produce the adhesive film are as follows:

[0099] • Base layer (A): Polyethylene terephthalate film (Lumirror #38-S10, manufactured by Toray Industries, Inc., 38 μm thick) (hereinafter also referred to as PET film 1).

[0100] • Adhesive layer (B) First, (meth)acrylic resin solutions to be used to form the adhesive coating solutions B1 to B3 and C described later were prepared by the following procedure. Ethyl acetate and toluene were mixed to prepare a mixed solvent. Next, 0.536 parts by mass of t-butyl peroxy-2-ethylhexanoate (perbutyl O, manufactured by NOF Corporation) as a polymerization initiator, 34.9 parts by mass of 2-ethylhexyl acrylate, 41.0 parts by mass of n-butyl acrylate, 14.7 parts by mass of ethyl acrylate, and 9.4 parts by mass of 2-hydroxyethyl methacrylate were added to the mixed solvent, and solution polymerization was carried out at a temperature of 83 to 87°C for 11 hours under stirring to obtain a (meth)acrylic resin solution with a solid content of 45% by mass.

[0101] Next, an adhesive coating solution B1 to be used to form the adhesive layer (B) was prepared by the following procedure. To 100 parts by mass of a (meth)acrylic resin solution, 8.4 parts by mass of an isocyanate crosslinking agent (Takenate D-178NL, manufactured by Mitsui Chemicals, Inc.), 19.0 parts by mass of a thermally expandable microsphere (Advancell EML-101, manufactured by Sekisui Chemical Co., Ltd.), and 2.37 parts by mass of a thickener (Pencell D-125, manufactured by Arakawa Chemical Industries, Ltd.) were added and stirred to obtain the adhesive coating solution B1.

[0102] Furthermore, an adhesive coating solution B2 used to form the adhesive layer (B) was prepared by the following procedure. To 100 parts by mass of a (meth)acrylic resin solution, 8.4 parts by mass of an isocyanate crosslinking agent (Takenate D-178NL, manufactured by Mitsui Chemicals, Inc.), 14.3 parts by mass of a thermally expandable microsphere (Advancell EML-101, manufactured by Sekisui Chemical Co., Ltd.), and 2.37 parts by mass of a thickener (Pencell D-125, manufactured by Arakawa Chemical Industries, Ltd.) were added and stirred to obtain the adhesive coating solution B2.

[0103] Furthermore, an adhesive coating solution B3 used to form the adhesive layer (B) was prepared by the following procedure. To 100 parts by mass of a (meth)acrylic resin solution, 8.4 parts by mass of an isocyanate crosslinking agent (Takenate D-178NL, manufactured by Mitsui Chemicals, Inc.), 9.5 parts by mass of a thermally expandable microsphere (Advancell EML-101, manufactured by Sekisui Chemical Co., Ltd.), and 2.37 parts by mass of a thickener (Pencell D-125, manufactured by Arakawa Chemical Industries, Ltd.) were added and stirred to obtain the adhesive coating solution B3.

[0104] - Intermediate layer (C) The adhesive coating solution C used to form the intermediate layer (C) was prepared by the following procedure. 100 parts by mass of (meth)acrylic resin solution was mixed with 0.9 parts by mass of isocyanate crosslinking agent (Takenate D-170, manufactured by Mitsui Chemicals, Inc.), and the mixture was adjusted with ethyl acetate to a solid content concentration of 40% by mass to obtain the adhesive coating solution C.

[0105] The adhesive films for each example were prepared using the following procedure.

[0106] [Example 1] An adhesive film of Example 1 was prepared by following the procedure below. An adhesive coating liquid C was applied to a PET film 1 (base layer (A)) and dried at a temperature of 120°C for 3 minutes to form an intermediate layer (C) with a thickness of 10 μm. Next, a separator 1 (SP-PET T18, manufactured by Mitsui Chemicals ICT Materia Co., Ltd., thickness 31 μm) was laminated onto the intermediate layer (C). Next, an adhesive coating liquid B1 was applied to a separator 2 (SP-PET T18, manufactured by Mitsui Chemicals ICT Materia Co., Ltd., thickness 31 μm) and dried at a temperature of 120°C for 3 minutes to form an adhesive layer (B) with a thickness of 14 μm. Next, after peeling off the separator 1 from the intermediate layer (C), the adhesive layer (B) was attached to the surface of the intermediate layer (C) on the side from which the separator 1 was peeled off to obtain the adhesive film of Example 1 in contact with the separator 2.

[0107] [Example 2] An adhesive film of Example 2 was prepared using the same procedure as in Example 1, except that the thickness of the intermediate layer (C) was changed from 10 μm to 20 μm.

[0108] [Example 3] An adhesive film of Example 3 was prepared using the same procedure as in Example 1, except that the thickness of the intermediate layer (C) was changed from 10 μm to 20 μm, and the thickness of the adhesive layer (B) was changed from 14 μm to 27 μm.

[0109] [Example 4] An adhesive film of Example 4 was prepared using the same procedure as in Example 1, except that the thickness of the intermediate layer (C) was changed from 10 μm to 20 μm, the adhesive coating liquid B1 was changed to adhesive coating liquid B2, and the thickness of the adhesive layer (B) was changed from 14 μm to 27 μm.

[0110] [Comparative Example 1] A comparative adhesive film of Comparative Example 1 was prepared using the same procedure as in Example 1, except that the thickness of the intermediate layer (C) was changed from 10 μm to 20 μm, the adhesive coating solution B1 was changed to adhesive coating solution B3, and the thickness of the adhesive layer (B) was changed from 14 μm to 27 μm.

[0111] The properties of the adhesive films in each example were measured using the following method. The measurement results are shown in Table 1.

[0112] (Measurement of arithmetic mean roughness Ra) Test film 1 was prepared by cutting the adhesive film of each example to 150 mm x 150 mm. Next, structure 1 was prepared by fixing the substrate layer (A) side of test film 1 to a silicon wafer (4 inch P-type Bare Si Wafer, manufactured by Shin-Etsu Chemical Co., Ltd.). Test film 1 was fixed to the silicon wafer using double-sided tape. After peeling off the separator 2 on the adhesive layer (B) side, structure 1 was left to stand at a temperature of 23°C, humidity of 50 ± 5% RH for 1 hour. Next, structure 1 was placed on a hot plate with the silicon wafer facing the hot plate side, and structure 1 was heated using the hot plate at 150°C for 60 seconds in an air atmosphere. After cooling to 23°C, the arithmetic mean roughness Ra of the adhesive layer (B) side of test film 1 was measured using a laser microscope (VHX-5000, manufactured by Keyence Corporation) in accordance with JIS B 0601:2013.

[0113] (Measurement of Peel Strength) Each example of adhesive film was cut to 300 mm x 50 mm to prepare test film 2. Next, the adhesive layer (B) side of test film 2 was attached to a silicon wafer (4 inch P-type Bare Si Wafer, manufactured by Shin-Etsu Chemical Co., Ltd.) under the conditions of temperature 23°C, humidity 50±5%RH, attachment speed 10 mm / sec, and pressure 0.4 MPa. Next, the silicon wafer with test film 2 attached was left to stand for 1 hour under the conditions of temperature 23°C, humidity 50±5%RH. Then, the 180° peel strength was measured by peeling test film 2 from the silicon wafer using a tensile testing machine (Autograph AGS-500, manufactured by Shimadzu Corporation) under the conditions of temperature 23°C, humidity 50±5%RH, peel angle 180°, and tensile speed 300 mm / min. The peel strength was measured using the value output by the tensile testing machine in units of [N / 25 mm].

[0114] (Measurement of Debonding Time) Test film 3 was prepared by cutting the adhesive film of each example to 150 mm x 150 mm. Next, structure 3 was prepared by attaching the adhesive layer (B) side of test film 3 to a silicon wafer (4 inch P-type Bare Si Wafer, manufactured by Shin-Etsu Chemical Co., Ltd.) under the conditions of a temperature of 23°C, humidity of 50 ± 5% RH, bonding speed of 10 mm / second, and pressure of 0.4 MPa. Next, structure 3 was left to stand at a temperature of 23°C, humidity of 50 ± 5% RH for 1 hour. Then, structure 3 was placed on a 150°C hot plate with the silicon wafer facing the hot plate side, and the time from the time structure 3 was placed on the hot plate until the entire adhesive film was debonded was measured and defined as the debonding time.

[0115]

[0116] Comparative Example 1 was an adhesive film with a relatively high arithmetic mean roughness Ra after heating compared to other conventional adhesive films, but its arithmetic mean roughness Ra was 11 μm. Therefore, it is considered that the Ra after heating of a typical conventional adhesive film is 10 μm or less.

[0117] This application claims priority based on Japanese Patent Application No. 2025-053217, filed on 27 March 2025, and incorporates all of its disclosures herein.

[0118] 10 Adhesive film A Substrate layer B Adhesive resin layer C Intermediate layer X Structure 20 Semiconductor substrate 21 Silicon wafer 22 Through electrode 23 Bump 24 Pad 25 Pad 30 Functional film 40 Electronic component 50 Laminate 90 Dicing ring P Preparation process Q Film formation process R Processing process S Expanding process T Heating process U Pickup process V Lamination process

Claims

1. An adhesive film comprising a base layer (A) and an adhesive resin layer (B), wherein the arithmetic mean roughness Ra determined by the following method 1 is 12 μm or more and 100 μm or less. (Method 1) A structure 1 is fabricated by fixing the side of the adhesive film facing the substrate layer (A) to a silicon wafer, and the structure is left standing at a temperature of 23°C, a humidity of 50±5%RH, and for 1 hour. Next, the structure 1 is placed on the hot plate so that the silicon wafer faces the hot plate, and the structure 1 is heated using the hot plate at 150°C for 60 seconds under air conditions. Then, the arithmetic mean roughness Ra of the side of the adhesive film facing the adhesive resin layer (B) is measured in accordance with JIS B 0601:2013.

2. The adhesive film according to claim 1, wherein the peel strength obtained by method 2 below is 3.0 N / 25 mm or less. (Method 2) The adhesive side of the adhesive film with the adhesive resin layer (B) is attached to a silicon wafer under the conditions of a temperature of 23°C, a humidity of 50±5%RH, an attachment speed of 10 mm / second, and a pressure of 0.4 MPa, and left to stand for 1 hour under the conditions of a temperature of 23°C, a humidity of 50±5%RH. Then, the adhesive film is peeled from the silicon wafer under the conditions of a temperature of 23°C, a humidity of 50±5%RH, a peel angle of 180°, and a tensile speed of 300 mm / min, and the 180° peel strength is measured.

3. The adhesive film according to claim 1 or 2, wherein the adhesive resin layer (B) contains thermally expandable microspheres.

4. The adhesive film according to claim 3, wherein the adhesive resin layer (B) is a layer formed from an adhesive resin composition containing an adhesive resin, the adhesive resin composition further contains the thermally expandable microspheres, and the content of the thermally expandable microspheres in the adhesive resin composition is 1.0 part by mass or more and 100 parts by mass or less, when the content of the adhesive resin in the adhesive resin composition is 100 parts by mass.

5. The adhesive film according to any one of claims 1 to 4, wherein the adhesive resin layer (B) is a layer formed from an adhesive resin composition containing an adhesive resin, and the adhesive resin composition further contains a crosslinking agent.

6. The adhesive film according to claim 5, wherein the amount of the crosslinking agent in the adhesive resin composition is 1.0 part by mass or more and 50 parts by mass or less, when the amount of the adhesive resin in the adhesive resin composition is 100 parts by mass.

7. The adhesive film according to any one of claims 1 to 6, wherein the thickness of the adhesive resin layer (B) is 0.1 μm or more and 50 μm or less.

8. The adhesive film according to any one of claims 1 to 7, further comprising an intermediate layer (C) between the base material layer (A) and the adhesive resin layer (B).

9. The adhesive film according to claim 8, wherein the thickness of the intermediate layer (C) is 0.1 μm or more and 50 μm or less.

10. The adhesive film according to any one of claims 1 to 9, wherein the adhesive resin layer (B) is a layer whose adhesive strength decreases when heated.

11. The adhesive film according to any one of claims 1 to 10, wherein the adhesive resin layer (B) comprises one or more selected from the group consisting of (meth)acrylic adhesive resin, silicone adhesive resin, urethane adhesive resin, olefin adhesive resin, and styrene adhesive resin.

12. The adhesive film according to any one of claims 1 to 11, wherein the base layer (A) comprises one or more selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyamide, polyimide, and polyetheretherketone.

13. The adhesive film according to any one of claims 1 to 12, wherein it is one or more selected from the group consisting of dicing tape, tape for temporarily fixing electronic components, tape for processing substrates, backgrinding tape, and surface protection tape.

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