Resin, adhesive composition, and adhesive film

Abstract

To provide an adhesive film capable of suppressing localization of an inorganic particle even when applied with external force, and a resin and an adhesive composition suitably used for forming the adhesive film.SOLUTION: There is provided a resin where at least a part of hydroxy groups of a phenoxy resin is modified by a group represented by the following formula (1). In the formula (1), R1 is a hydrogen atom or a methyl group, x is an integer of 2-6, and y is an integer of 2-6. * is a bond position for bonding to an oxygen atom derived from a hydroxyl group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to resins, adhesive compositions, and adhesive films. [Background technology]

[0002] Conventionally, wire bonding, which uses thin metal wires such as gold wires, has been widely used to connect semiconductor chips to substrates. However, in order to meet the demands for higher performance, higher integration, and faster speeds in semiconductor devices, flip-chip connection (FC connection), which directly connects the semiconductor chip to the substrate by forming conductive protrusions called bumps on the semiconductor chip or substrate, is becoming more popular.

[0003] For example, the COB (Chip On Board) type connection method, which is widely used for BGA (Ball Grid Array), CSP (Chip Size Package), etc., in connection between semiconductor chips and substrates, also falls under the FC connection method. The FC connection method is also widely used in COC (Chip On Chip) type connection methods, which form connection parts (e.g., bumps and wiring) on ​​semiconductor chips to connect between semiconductor chips (see, for example, Patent Document 1).

[0004] Furthermore, in the case of packages that are strongly required to be even smaller, thinner, and more highly functional, chip-stacked packages, POP (Package On Package), TSV (Through-Silicon Via), and other technologies that use the above-mentioned connection methods to stack chips in multiple layers, are beginning to become widespread. These stacking and multi-layering technologies arrange semiconductor chips and other components in three dimensions, making it possible to make packages smaller than methods that arrange them in two dimensions. Furthermore, because they are effective in improving semiconductor performance, reducing noise, reducing mounting area, and saving power, they are attracting attention as a next-generation semiconductor wiring technology.

[0005] In recent years, with the increasing functionality and integration of packages, a method has been proposed in which an adhesive film containing inorganic particles is used as an adhesive member between a semiconductor chip and a substrate in order to achieve both productivity and connection reliability (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-294382 [Patent Document 2] International Publication No. 2018 / 225191 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when an adhesive film containing inorganic particles is used as an adhesive member, it is difficult to control the fluidity of the adhesive during connection. When connecting a semiconductor chip and a substrate (when an external force is applied), adhesive components may protrude from the adhesive layer formed from the adhesive film, resulting in localization of inorganic particles within the adhesive member. The protruding adhesive components (inorganic particles, etc.) may cause damage to the semiconductor chip, substrate, etc. Therefore, there is a need for the development of an adhesive film and its material (resin) that can suppress this phenomenon.

[0008] The present disclosure aims to provide an adhesive film that can suppress localization of inorganic particles even when an external force is applied, and a resin and adhesive composition that are suitable for use in forming such an adhesive film. [Means for solving the problem]

[0009] The present disclosure provides the resins described in [1] and [2], the adhesive compositions described in [3] to [6], and the adhesive films described in [7] and [8].

[0010] [1] A phenoxy resin in which at least a portion of the hydroxy groups has been modified with a group represented by the following formula (1): [ka] [In formula (1), R 1 represents a hydrogen atom or a methyl group, x represents an integer of 2 to 6, and y represents an integer of 2 to 6. * represents the bonding position to the oxygen atom derived from the hydroxy group.] [2] The resin according to [1], wherein the modification rate of the group represented by formula (1) relative to the hydroxyl groups of the phenoxy resin is 0.5 to 50%. [3] An adhesive composition containing inorganic particles, a curable resin component, and a thermoplastic resin, wherein the thermoplastic resin contains the resin described in [1] or [2]. [4] The adhesive composition according to [3], wherein the curable resin component contains a radical polymerizable compound and a radical polymerization initiator. [5] The adhesive composition according to [4], wherein the curable resin component further contains a cationic polymerizable compound and a cationic polymerization initiator. [6] The adhesive composition according to [5], wherein the cationically polymerizable compound contains an epoxy resin. [7] An adhesive film having an adhesive layer containing the adhesive composition according to any one of [3] to [6] or a cured product thereof. [8] The adhesive film according to [7], which is for circuit connection. [Effects of the Invention]

[0011] The present disclosure provides an adhesive film that can suppress localization of inorganic particles even when an external force is applied, and also provides a resin and adhesive composition that are suitable for use in forming such an adhesive film. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments.

[0013] In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, in numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with a value shown in the examples. Furthermore, individually described upper and lower limits can be arbitrarily combined. In the expression "A to B," the numerical values ​​A and B at both ends are included as the lower and upper limits, respectively, in the numerical range. In this specification, for example, the expression "10 or more" means "10" and "a number greater than 10," and this also applies when the numerical values ​​are different. Furthermore, for example, the expression "10 or less" means "10" and "a number less than 10," and this also applies when the numerical values ​​are different.

[0014] In this specification, "(meth)acrylate" means at least one of an acrylate and its corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylic acid." Furthermore, "A or B" may include either A or B, or may include both.

[0015] Unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. When a plurality of substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the plurality of substances present in the composition unless otherwise specified.

[0016] [resin] In one embodiment, the resin is a phenoxy resin in which at least a portion of the hydroxy groups has been modified with a group represented by the following formula (1). The resin of this embodiment can be said to be a reaction product of a phenoxy resin and an isocyanate compound having a (meth)acryloyl group. Here, the isocyanate compound having a (meth)acryloyl group is a compound represented by the following formula (2). That is, the group represented by formula (1) is a group derived from the compound represented by formula (2). The resin of this embodiment is a component that can function as a thermoplastic resin.

[0017] [ka]

[0018] In formula (1), R 1 represents a hydrogen atom or a methyl group. x represents an integer of 2 to 6 and may be 2 to 5, 2 to 4, or 2 to 3. y represents an integer of 2 to 6 and may be 2 to 5, 2 to 4, or 2 to 3. * represents the bonding position to the oxygen atom derived from the hydroxy group.

[0019] [ka]

[0020] In formula (2), R 1 , x, and y are as defined above.

[0021] The compound represented by formula (2) can be obtained by a known method such as the phosgene method using a corresponding amino alcohol having an ether bond, or a commercially available product can also be used. The compound represented by formula (2) can be obtained, for example, by reacting an amino alcohol having an ether bond, such as 2-(2-aminoethoxy)ethanol or 2-(2-(2-aminoethoxy)ethoxy)ethanol, with an acid chloride, such as (meth)acrylic acid chloride, and then reacting the resulting mixture with phosgene. Commercially available products include Karenz (registered trademark) MOI-EG (R 1is a methyl group, x is 2, and y is 2, and is a compound represented by formula (2), manufactured by Showa Denko KK

[0022] Phenoxy resins can be obtained, for example, by reacting a polyhydric phenol compound with a polyepoxy compound. Such phenoxy resins usually have a structure (e.g., a structure derived from the following formula (X)) in which an aliphatic hydroxyl group is generated at the bond formed by the reaction of an aromatic hydroxyl group (hydroxy group) with an epoxy group. As such phenoxy resins, those obtained by reacting a bisphenol with a diglycidyl etherified bisphenol are easily available and are common.

[0023] Examples of polyhydric phenol compounds include bisphenol A and bisphenol F. Examples of polyepoxy compounds include bisphenol A diglycidyl ether and bisphenol F diglycidyl ether.

[0024] The phenoxy resin may be, for example, a polyhydroxypolyether (thermoplastic resin) synthesized from bisphenols and epichlorohydrin. Such a phenoxy resin usually has a structure derived from epichlorohydrin, as shown in the following formula (X) (* indicates a bond position), and the hydroxy group of the phenoxy resin is a methine carbon atom (C A ) is bonded to

[0025] [ka]

[0026] Commercially available phenoxy resins can be used, such as FX-293, YP-70, ZX1356-2, FX-310, and TOPR-300 (all manufactured by Nippon Steel Chemical & Material Co., Ltd.), PKHA, PKHB, PKHC, PKHH, PKHJ, PKFE, and PKHP-200 (all manufactured by Huntsman International LLC.), jER1256, jER4250, and jER4275 (all manufactured by Mitsubishi Chemical Corporation), H360, and EXA-192 (all manufactured by DIC Corporation).

[0027] The modification rate of the group represented by formula (1) relative to the hydroxy groups of the phenoxy resin may be 0.5 to 50%. If the modification rate is 0.5% or more, toughness tends to be improved when applied to an adhesive composition. If the modification rate is 50% or less, flexibility tends to be ensured when applied to an adhesive composition. The modification rate may be 1.0% or more, 1.5% or more, or 2.0% or more, or may be 45% or less, 40% or less, 35% or less, or 20% or less.

[0028] Here, the modification rate of the group represented by formula (1) relative to the hydroxy group of the phenoxy resin is, for example, as follows for a resin modified with a group represented by formula (1): 1 The H-NMR can be measured and the integral value of the peak in the spectrum obtained can be used to calculate the ratio. The resin modified with the group represented by formula (1) has a structure derived from the following formula (Y) (* indicates the bonding position) in addition to the structure derived from formula (X). In the structure derived from formula (X), the methine carbon atom (C A ) is bonded to a hydrogen atom (H A The chemical shift values ​​(based on the methyl group of tetramethylsilane (TMS)) assigned to the methine carbon atom (C B ) is bonded to a hydrogen atom (H B The chemical shifts assigned to the methyl group of tetramethylsilane (TMS) are AThe chemical shifts are shifted downfield from those assigned to hydrogen atoms (H A ) and the integral value of the peaks assigned to hydrogen atoms (H B ) relative to the total integral of the peaks assigned to hydrogen atoms (H B ) (H B integral value of / (H A Integral value of +H B The modification rate can be calculated by calculating the integral of the above formula (integral value of the above formula) × 100(%). The modification rate can be calculated from the amount of the compound represented by formula (2) added by plotting the relationship between the amount of the compound represented by formula (2) added when reacting the phenoxy resin with the compound represented by formula (2) and the modification rate to create a calibration curve.

[0029] [ka]

[0030] The resin of this embodiment can be obtained by reacting a phenoxy resin with a compound represented by formula (2) in an organic solvent, optionally in the presence of a catalyst.

[0031] The amount of the compound represented by formula (2) added can be set arbitrarily so that the modification rate of the group represented by formula (1) relative to the hydroxy groups of the phenoxy resin is a predetermined value. The amount of the compound represented by formula (2) added may be 0.5 to 50 mol% relative to the total molar amount of hydroxy groups in the phenoxy resin. The amount of the compound represented by formula (2) added may be 1.0 mol% or more, 1.5 mol% or more, or 2.0 mol% or more, or 45 mol% or less, 40 mol% or less, 35 mol% or less, or 20 mol% or less, relative to the total molar amount of hydroxy groups in the phenoxy resin.

[0032] The organic solvent can be any solvent capable of dissolving the phenoxy resin and the compound represented by formula (2). Examples of the organic solvent include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p-cymene; aliphatic hydrocarbons such as hexane and heptane; cyclic alkanes such as methylcyclohexane; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone (NMP).

[0033] The catalyst may be a urethanization catalyst. Examples of the catalyst include tin-based catalysts such as dibutyltin dilaurate, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, and dioctyltin dilaurate; amine-based catalysts such as triethylamine, triethylenediamine (TEDA), 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), 1,5-diazabicyclo[4.3.0]nonene-5 (DBN), and 1-isobutyl-2-methylimidazole (IBM); and zirconium-based catalysts such as normal propyl zirconate, normal butyl zirconate, zirconium tetraacetylacetonate, zirconium monoacetylacetonate, and zirconium ethylacetoacetate. The catalyst content may be 0.01 to 1% by mass relative to the total mass of the compound represented by formula (2).

[0034] The reaction temperature of the phenoxy resin and the compound represented by formula (2) may be, for example, 0 to 200° C., 20 to 150° C., or 40 to 100° C. The time for maintaining the reaction temperature may be, for example, 0.1 to 12 hours, and may be 8 hours or less, 6 hours or less, or 4 hours or less.

[0035] The resin of this embodiment can be suitably used to form an adhesive film that can suppress localization of inorganic particles even when an external force is applied. The reason why the use of the resin of this embodiment can suppress localization of inorganic particles is not necessarily clear, but the inventors speculate that this is because (meth)acryloyl groups in the resin react alone or simultaneously with other components when exposed to light (e.g., ultraviolet light) or heat, forming new chemical bonds and resulting in a structure with higher toughness.

[0036] [Adhesive composition] The adhesive composition of one embodiment contains at least inorganic particles (hereinafter sometimes referred to as "component (A)"), a curable resin component (hereinafter sometimes referred to as "component (B)"), and a thermoplastic resin (hereinafter sometimes referred to as "component (C)").

[0037] (A) Component: Inorganic particles Component (A) may be conductive particles or non-conductive particles (insulating particles). When component (A) is conductive particles, the adhesive composition can be used, for example, as a conductive adhesive. When component (A) is non-conductive particles, the adhesive composition can be used, for example, as an insulating adhesive.

[0038] The conductive particles are not particularly limited as long as they are conductive, and may be metal particles made of metals such as Au, Ag, Pd, Ni, Cu, or solder, or conductive carbon particles made of conductive carbon. The conductive particles may also be coated conductive particles having a core made of non-conductive glass, silica, ceramic, plastic (e.g., polystyrene), or the like, and a coating layer containing the above metal or conductive carbon that coats the core. Among these, the conductive particles are preferably metal particles made of a heat-fusible metal, or coated conductive particles having a core made of silica or plastic and a coating layer containing a metal or conductive carbon that coats the core. Such coated conductive particles can be easily deformed by applying heat or pressure to a cured product of a thermosetting resin component. Therefore, for example, when electrically connecting opposing electrodes of a semiconductor chip and a substrate, the contact area between the electrodes and the conductive particles can be increased, thereby further improving the conductivity between the electrodes.

[0039] The conductive particles may be insulating coated conductive particles comprising the above-mentioned metal particles, conductive carbon particles, or coated conductive particles, and an insulating layer containing an insulating material such as resin and coating the surfaces of the particles. When the conductive particles are insulating coated conductive particles, even if the content of the conductive particles is high, the insulating layer is provided on the surface of the particles, so that the occurrence of short circuits due to contact between the conductive particles can be suppressed, and the insulation between adjacent electrode circuits in the semiconductor chip and the substrate can also be improved.

[0040] The maximum particle size of the conductive particles must be smaller than the minimum electrode spacing (the shortest distance between adjacent electrodes). From the viewpoint of excellent dispersibility and conductivity, the maximum particle size of the conductive particles may be 1.0 μm or more, 2.0 μm or more, or 2.5 μm or more. From the viewpoint of excellent dispersibility and conductivity, the maximum particle size of the conductive particles may be 20 μm or less, 10 μm or less, or 5 μm or less. In this specification, the particle size of 300 random conductive particles (pcs) is measured by observation using a scanning electron microscope (SEM), and the largest value obtained is defined as the maximum particle size of the conductive particles. Note that when the conductive particles are not spherical, such as when they have protrusions, the particle size of the conductive particles is defined as the diameter of a circle circumscribing the conductive particles in the SEM image.

[0041] The average particle size of the conductive particles may be 1.0 μm or more, 2.0 μm or more, or 2.5 μm or more from the viewpoint of excellent dispersibility and conductivity. The average particle size of the conductive particles may be 20 μm or less or 10 μm or less from the viewpoint of excellent dispersibility and conductivity. In this specification, the particle size of 300 random conductive particles (pcs) is measured by observation using a scanning electron microscope (SEM), and the simple average of the particle sizes obtained is defined as the average particle size.

[0042] Examples of non-conductive particles include metal oxide particles such as silica particles, alumina particles, silica-alumina particles, titania particles, and zirconia particles; and inorganic particles such as metal nitride particles.

[0043] The content of component (A) may be 1% by mass or more, 5% by mass or more, or 10% by mass or more, based on the total mass of the adhesive composition (excluding the organic solvent; the same applies below). The content of component (A) may be 80% by mass or less, 60% by mass or less, or 40% by mass or less, based on the total mass of the adhesive composition. When the content of component (A) is within the above range, the effects of the present disclosure tend to be significantly achieved. The content of component (A) in the adhesive layer (based on the total mass of the adhesive layer) may be the same as the above range.

[0044] (B) Component: Curable resin component The component (B) may contain a resin component having radical curability (radical curable resin component). That is, the component (B) may contain a radical polymerizable compound (hereinafter, sometimes referred to as the "component (B1)") and a radical polymerization initiator (hereinafter, sometimes referred to as the "component (B2)"). Note that the resin in which at least a portion of the hydroxy groups in a phenoxy resin described below are modified with a group represented by formula (1) is not included in the component (B1). The radical curable resin component may be a photoradical curable resin component that cures upon light irradiation, or a thermal radical curable resin component that cures upon heat. In one embodiment, the radical curable resin component may be a photoradical curable resin component. The photoradical curable resin component may be a combination of the component (B1) and a photoradical polymerization initiator (hereinafter, sometimes referred to as the "component (B2L)"). The thermal radical curable resin component may be a combination of the component (B1) and a thermal radical polymerization initiator (hereinafter, sometimes referred to as the "component (B2H)").

[0045] Component (B1): radical polymerizable compound Component (B1) is a compound that undergoes polymerization or crosslinking due to radicals generated by irradiating component (B2) with light (e.g., ultraviolet light) or heating. Component (B1) may be either a monomer or a polymer (or oligomer) formed by polymerization of one or more monomers.

[0046] The component (B1) is a compound having a radically polymerizable group that reacts with radicals. The component (B1) may be a compound that does not have a cationic polymerizable group. Examples of the radically polymerizable group include (meth)acryloyl, vinyl, allyl, styryl, alkenyl, alkenylene, and maleimide groups. The number of radically polymerizable groups (the number of functional groups) possessed by the component (B1) may be 2 or more from the viewpoints of easily achieving a desired melt viscosity after polymerization and achieving better connection reliability, and may be 10 or less from the viewpoint of suppressing cure shrinkage during polymerization. Furthermore, in order to balance the crosslink density and cure shrinkage, in addition to compounds having the number of radically polymerizable groups within the above range, compounds having the number of radically polymerizable groups outside the above range may be used.

[0047] From the viewpoint of suppressing the flow of component (A), component (B1) may contain, for example, a polyfunctional (difunctional or higher) (meth)acrylate. The polyfunctional (difunctional or higher) (meth)acrylate may be a difunctional (meth)acrylate, and the difunctional (meth)acrylate may be a difunctional aromatic (meth)acrylate.

[0048] Examples of polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate. acrylate, ethoxylated polypropylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, glycol Serin di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, ethoxylated 2-methyl-1,3-propanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, ethoxylated propoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, propoxylated aliphatic (meth)acrylates such as propoxylated pentaerythritol tri(meth)acrylate, ethoxylated propoxylated pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, propoxylated pentaerythritol tetra(meth)acrylate, ethoxylated propoxylated pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate;Aromatic (meth)acrylates such as ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, ethoxylated propoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol F di(meth)acrylate, propoxylated bisphenol F di(meth)acrylate, ethoxylated propoxylated bisphenol F di(meth)acrylate, ethoxylated fluorene di(meth)acrylate, propoxylated fluorene di(meth)acrylate, and ethoxylated propoxylated fluorene di(meth)acrylate; aromatic epoxy (meth)acrylates such as bisphenol epoxy (meth)acrylate, phenol novolac epoxy (meth)acrylate, and cresol novolac epoxy (meth)acrylate;

[0049] The content of the polyfunctional (difunctional or higher) (meth)acrylate may be, for example, 40 to 100 mass %, 50 to 100 mass %, or 60 to 100 mass % based on the total mass of the component (B1) from the viewpoint of suppressing particle flow.

[0050] The component (B1) may further contain a monofunctional (meth)acrylate in addition to a polyfunctional (difunctional or higher) (meth)acrylate. Examples of the monofunctional (meth)acrylate include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, butoxyethyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octylheptyl (meth)acrylate, and nonyl (meth)acrylate. Decyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, mono(2-(meth)acryloyloxy) Aliphatic (meth)acrylates such as diethyl succinate; benzyl (meth)acrylate, phenyl (meth)acrylate, o-biphenyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, phenoxyethyl (meth)acrylate, p-cumylphenoxyethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 1-naphthoxyethyl (meth)acrylate, 2-naphthoxyethyl (meth)acrylate, phenoxypolyether aromatic (meth)acrylates such as ethylene glycol (meth)acrylate, nonylphenoxy polyethylene glycol (meth)acrylate, phenoxy polypropylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-(o-phenylphenoxy)propyl (meth)acrylate, 2-hydroxy-3-(1-naphthoxy)propyl (meth)acrylate, and 2-hydroxy-3-(2-naphthoxy)propyl (meth)acrylate;Examples of such acrylates include (meth)acrylates having an epoxy group such as glycidyl (meth)acrylate, (meth)acrylates having an alicyclic epoxy group such as 3,4-epoxycyclohexylmethyl (meth)acrylate, and (meth)acrylates having an oxetanyl group such as (3-ethyloxetan-3-yl)methyl (meth)acrylate.

[0051] The content of the monofunctional (meth)acrylate may be, for example, 0 to 60 mass %, 0 to 50 mass %, or 0 to 40 mass % based on the total mass of the component (B1).

[0052] The component (B1) may contain other radically polymerizable compounds in addition to polyfunctional (difunctional or higher) and monofunctional (meth)acrylates. Examples of other radically polymerizable compounds include maleimide compounds, vinyl ether compounds, allyl compounds, styrene derivatives, acrylamide derivatives, and nadimide derivatives. The content of other radically polymerizable compounds may be, for example, 0 to 40% by mass based on the total mass of the component (B1).

[0053] Component (B2): Radical polymerization initiator (Component (B2L): Photoradical polymerization initiator) The component (B2L) is a polymerization initiator that generates radicals when irradiated with light having a wavelength in the range of 150 to 750 nm, light having a wavelength in the range of 254 to 405 nm, or light having a wavelength of 365 nm (for example, ultraviolet light).

[0054] The component (B2L) decomposes under light to generate free radicals. In other words, the component (B2L) is a compound that generates radicals upon application of external light energy. The component (B2L) may be a compound having an oxime ester structure, a bisimidazole structure, an acridine structure, an α-aminoalkylphenone structure, an aminobenzophenone structure, an N-phenylglycine structure, an acylphosphine oxide structure, a benzyl dimethyl ketal structure, an α-hydroxyalkylphenone structure, or the like. From the viewpoint of facilitating the attainment of a desired melt viscosity, the component (B2L) may be a compound having at least one structure selected from the group consisting of an oxime ester structure, an α-aminoalkylphenone structure, and an acylphosphine oxide structure.

[0055] Specific examples of compounds having an oxime ester structure include 1-phenyl-1,2-butanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-o-benzoyloxime, 1,3-diphenylpropanetrione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetrione-2-(o-benzoyl)oxime, 1,2-octanedione, 1-[4-(phenylthio)phenyl-, 2-(o-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(o-acetyloxime), and the like.

[0056] Specific examples of compounds having an α-aminoalkylphenone structure include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-morpholinophenyl)-butanone-1, and the like.

[0057] Specific examples of compounds having an acylphosphine oxide structure include bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide.

[0058] The amount of the component (B2L) may be, for example, 0.1 to 10 parts by mass, 0.3 to 7 parts by mass, or 0.5 to 5 parts by mass per 100 parts by mass of the component (B1) in order to suppress the flow of the component (A).

[0059] (Component (B2H): Thermal radical polymerization initiator) The component (B2H) is a polymerization initiator that generates radicals when exposed to heat. The one-hour half-life temperature of the component (B2H) may be, for example, 50 to 100°C.

[0060] Examples of the (B2H) component include diacyl peroxides such as octanoyl peroxide, lauroyl peroxide, stearyl peroxide, and benzoyl peroxide; t-butyl peroxypivalate, t-hexyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-hexylperoxyisopropyl monocarbonate, and t-butylperoxyisopropyl ether. peroxyesters such as 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane and 2,2'-azobis(4-methoxy-2'-dimethylvaleronitrile); and azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(4-methoxy-2'-dimethylvaleronitrile).

[0061] The amount of the component (B2H) may be, for example, 0.1 to 15 parts by mass, 0.3 to 12 parts by mass, or 0.5 to 10 parts by mass per 100 parts by mass of the component (B1) in order to suppress the flow of the component (A).

[0062] The content of the components (B1) and (B2) may be 20 to 100 mass %, 30 to 100 mass %, or 40 to 100 mass % based on the total mass of the component (B).

[0063] The component (B) may further contain a resin component having cation curability (cationic curable resin component). That is, the component (B) may further contain a cationically polymerizable compound (hereinafter sometimes referred to as the "component (B3)") and a cationic polymerization initiator (hereinafter sometimes referred to as the "component (B4)"). The cationic curable resin component may be a photocationic curable resin component that cures upon light irradiation, or a thermocationic curable resin component that cures upon heat. In one embodiment, the cationic curable resin component may be a thermocationic curable resin component. The photocationic curable resin component may be a combination of the component (B3) and a photocationic polymerization initiator (hereinafter sometimes referred to as the "component (B4L)"). The thermocationic curable resin component may be a combination of the component (B3) and a thermoradical polymerization initiator (hereinafter sometimes referred to as the "component (B4H)"). The component (B) may contain a photoradical curable resin component and a thermocationic curable resin component. When component (B) contains a photoradical curable resin component and a thermocationically curable resin component, the adhesive composition can be cured in stages by selectively using light irradiation or heat.

[0064] Component (B3): Cationic polymerizable compound Component (B3) is a compound that undergoes polymerization or crosslinking in response to a substance (such as an acid) generated by irradiating component (B4) with light (e.g., ultraviolet light) or heating. Component (B3) is a compound having a cationically polymerizable group. Examples of the cationically polymerizable group include cyclic ether groups such as an oxetanyl group and an epoxy group. Component (B3) may be a compound without a radically polymerizable group. Examples of component (B3) include an epoxy resin (epoxy compound) having an epoxy group, an oxetane compound having an oxetanyl group, and an alicyclic epoxy compound having an alicyclic epoxy group. Component (B3) may contain a monofunctional cationically polymerizable compound or a polyfunctional (difunctional or higher) cationically polymerizable compound. The cationically polymerizable group in the polyfunctional cationically polymerizable compound may be a group selected from the group consisting of an epoxy group, an oxetanyl group, and an alicyclic epoxy group.

[0065] The epoxy resin used as component (B3) is not particularly limited as long as it has an epoxy group. Examples of epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, naphthalene epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, phenol aralkyl epoxy resins, biphenyl epoxy resins, triphenylmethane epoxy resins, dicyclopentadiene epoxy resins, and various polyfunctional epoxy resins.

[0066] The oxetane compound as component (B3) can be used without any particular limitation as long as it is a compound having an oxetanyl group. Commercially available oxetane compounds include, for example, ETERNACOLL OXBP (trade name: 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, manufactured by Ube Industries, Ltd.), OXSQ, OXT-121, OXT-221, OXT-101, and OXT-212 (trade names, manufactured by Toagosei Co., Ltd.).

[0067] The alicyclic epoxy compound as component (B3) can be any compound having an alicyclic epoxy group (e.g., an epoxycyclohexyl group) without any particular limitation. Commercially available alicyclic epoxy compounds include EHPE3150, EHPE3150CE, Celloxide 8010, Celloxide 2021P, and Celloxide 2081 (trade names, manufactured by Daicel Corporation).

[0068] Component (B4): Cationic polymerization initiator (Component (B4L): Photocationic polymerization initiator) The component (B4L) is a polymerization initiator that generates a substance that initiates cationic polymerization when irradiated with light having a wavelength in the range of 150 to 750 nm, light having a wavelength in the range of 254 to 405 nm, or light having a wavelength of 365 nm (e.g., ultraviolet light). Note that some of the components (B4L) may also function as the component (B4H), which will be described later.

[0069] The (B4L) component is, for example, BF4 - , BR4 - (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups), PF6 - , SbF6 - , AsF6 - , SO4R - (R represents an alkyl group), and other onium salts such as sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, and anilinium salts.

[0070] Commercially available products of the (B4L) component include, for example, CPI-100P, CPI-110P, CPI-101A, CPI-200K, and CPI-210S (all manufactured by San-Apro Ltd.), UVI-6990, UVI-6992, and UVI-6976 (all manufactured by Dow Chemical Japan), and SP-150, SP-152, SP-170, SP-172, and SP-300 (all manufactured by ADEKA Corporation).

[0071] The content of the (B4L) component may be, for example, 0.1 to 15 parts by mass, 0.3 to 12 parts by mass, 0.5 to 10 parts by mass, or 1 to 5 parts by mass per 100 parts by mass of the (B3) component, in order to ensure the formability and curability of the adhesive film.

[0072] (B4H) component: thermal cationic polymerization initiator The component (B4H) is a polymerization initiator that generates a substance that initiates cationic polymerization when heated (for example, at 40 to 150°C). Note that some of the components (B4H) may also function as the above-mentioned component (B4L).

[0073] The (B4H) component, like the (B4L) component, can be, for example, BF4 - , BR4 - (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups), PF6 - , SbF6 - , AsF6 - , SO4R -(R represents an alkyl group), and other onium salts such as sulfonium salts, pyridium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, and anilinium salts.

[0074] Examples of commercially available products of component (B4H) include CP-66, CP-77 (all manufactured by ADEKA CORPORATION), SI-25, SI-45, SI-60, SI-60L, SI-60LA, SI-60B, SI-80L, SI-100L, SI-110L, and SI-180L (all manufactured by Sanshin Chemical Industry Co., Ltd.), CI-2855 (manufactured by Nippon Soda Co., Ltd.), and benzyl(4-hydroxyphenyl)methylsulfonium hexafluoroantimonate (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0075] The component (B4H) may be used in combination with a polymerization inhibitor such as 4-hydroxyphenyldimethylsulfonium methylsulfate.

[0076] The content of the (B4H) component (total amount of the (B4H) component and the polymerization inhibitor) may be, for example, 0.01 to 15 parts by mass, 0.05 to 10 parts by mass, or 0.1 to 7 parts by mass per 100 parts by mass of the (B3) component, in order to ensure the formability and curability of the adhesive film.

[0077] The contents of the components (B3) and (B4) may be, for example, 0 to 80 mass %, 0 to 70 mass %, or 0 to 60 mass % based on the total mass of the component (B).

[0078] The content of component (B), based on the total mass of the adhesive composition, may be 20% by mass or more, 30% by mass or more, or 40% by mass or more. The content of component (B), based on the total mass of the adhesive composition, may be 80% by mass or less, 70% by mass or less, or 60% by mass or less. When the content of component (B) is within the above range, the effects of the present disclosure tend to be significantly exhibited. The content of component (B) in the adhesive layer (based on the total mass of the adhesive layer) may be the same as the above range.

[0079] (C) Component: Thermoplastic resin Component (C) includes the above-mentioned phenoxy resin in which at least a portion of the hydroxy groups have been modified with a group represented by formula (1) (hereinafter, sometimes referred to as "component (C1)"). Component (C1) is not included in component (B1). Component (C) may further include, in addition to component (C1), a thermoplastic resin other than component (C1) (hereinafter, sometimes referred to as "component (C2)").

[0080] Component (C1): a phenoxy resin in which at least a portion of the hydroxy groups has been modified with a group represented by formula (1) By including component (C1) as component (C), the adhesive composition can form an adhesive film that can suppress localization of inorganic particles even when external force is applied. While the reason for this effect is not entirely clear, the inventors speculate that it is because the (meth)acryloyl groups in component (C1) react alone or simultaneously with other components upon irradiation with light (e.g., ultraviolet light) or heat, forming new chemical bonds and resulting in a structure with greater toughness. Furthermore, this effect tends to be further enhanced when component (B) includes components (B1) and (B2).

[0081] The content of the component (C1) may be 20 to 100 mass %, 30 to 100 mass %, or 40 to 100 mass %, based on the total mass of the component (C).

[0082] Component (C2): Thermoplastic resin other than component (C1) Examples of the component (C2) include phenoxy resins, polyester resins, polyamide resins, polyurethane resins, polyester urethane resins, acrylic rubbers, etc. that are not modified with a group represented by formula (1). Among these, the component (C2) may be, for example, a phenoxy resin that is not modified with a group represented by formula (1).

[0083] The content of the component (C2) may be, for example, 0 to 80 mass %, 0 to 70 mass %, or 0 to 60 mass % based on the total mass of the component (C).

[0084] The content of component (C) may be 1 mass % or more, 5 mass % or more, or 10 mass % or more, and may be 50 mass % or less, 40 mass % or less, or 30 mass % or less, based on the total mass of the adhesive composition. The content of component (C) in the adhesive layer (based on the total mass of the adhesive layer) may be in the same range as above.

[0085] When the adhesive composition contains only the component (C1) as the component (C), the modification rate of the group represented by formula (1) relative to the hydroxy groups of the phenoxy resin of the component (C1) may be 0.5% or more, 1.0% or more, 1.5% or more, or 2.0% or more.

[0086] When the adhesive composition contains components (C1) and (C2) as component (C), the localization of inorganic particles in the adhesive film can be further suppressed by increasing the modification ratio of the group represented by formula (1) to the hydroxy groups of the phenoxy resin of component (C1), depending on the content of component (C2). From this perspective, the modification ratio of the group represented by formula (1) to the hydroxy groups of the phenoxy resin of component (C1) may be 1.0% or more, 2.0% or more, 5.0% or more, or 8.5% or more.

[0087] The adhesive composition may further contain other components in addition to components (A), (B), and (C), such as a coupling agent (hereinafter sometimes referred to as "component (D)").

[0088] Examples of component (D) include silane coupling agents having organic functional groups such as (meth)acryloyl groups, mercapto groups, amino groups, imidazole groups, and epoxy groups, silane compounds such as tetraalkoxysilanes, tetraalkoxytitanate derivatives, and polydialkyltitanate derivatives. By further including component (D) in the adhesive composition, adhesion can be further improved. Component (D) may be, for example, a silane coupling agent.

[0089] The content of component (D) may be 0.1 to 10% by mass based on the total mass of the adhesive composition. The content of component (D) in the adhesive layer (based on the total mass of the adhesive layer) may be in the same range as above.

[0090] The adhesive composition may further contain other additives such as organic fillers (organic particles), softeners, accelerators, anti-degradants, colorants, flame retardants, and thixotropic agents. The content of the other additives may be, for example, 0.1 to 10% by mass based on the total mass of the adhesive composition. The content of the other additives in the adhesive layer (based on the total mass of the adhesive layer) may be the same as the above range.

[0091] [Adhesive film] An adhesive film of one embodiment includes an adhesive layer (first adhesive layer) containing the above-described adhesive composition or a cured product thereof. The adhesive composition in the first adhesive layer may be partially or completely cured, or may not be cured. The adhesive film of this embodiment is suitable for use in circuit connection.

[0092] The adhesive film can be obtained, for example, by the following method. First, the above-mentioned adhesive composition is dissolved or dispersed in an organic solvent by stirring, kneading, or the like to prepare a varnish composition. The varnish composition is then applied to a release-treated substrate using a knife coater, roll coater, applicator, comma coater, die coater, or the like, and the organic solvent is then volatilized by heating, thereby forming a first adhesive layer (first adhesive film) made of the adhesive composition on the substrate. At this time, the thickness of the finally obtained first adhesive layer (first adhesive film) can be adjusted by adjusting the amount of varnish composition applied.

[0093] When the adhesive composition contains a photocurable resin component (a photoradical curable resin component or a photocationically curable resin component) as the curable resin component, the first adhesive layer may be irradiated with light to cure the photocurable resin component in the first adhesive layer. In this case, the first adhesive layer contains a cured product of the photocurable resin component. When the photocurable resin component is a photoradical curable resin component, the radical polymerizable group of component (B1) may react with the (meth)acryloyl group of the group represented by formula (1) of component (C1) to form a bond. When the adhesive composition contains a photocurable resin component and a thermosetting resin component as the curable resin components, and the curing systems of the components are different (for example, a combination of a photoradical curable resin component and a thermocationically curable resin component), the first adhesive layer contains a cured product of the photocurable resin component and an (uncured) thermosetting resin component.

[0094] The organic solvent used in preparing the varnish composition is not particularly limited as long as it has the property of being able to uniformly dissolve or disperse each component. Examples of the organic solvent include the same organic solvent used in the reaction between the phenoxy resin and the compound represented by formula (2). The organic solvent used in the reaction between the phenoxy resin and the compound represented by formula (2) may be used as is in preparing the varnish composition.

[0095] The stirring and kneading during preparation of the varnish composition can be carried out using, for example, a stirrer, a kneading machine, a three-roll mill, a ball mill, a bead mill, a homodisper, or the like.

[0096] The substrate is not particularly limited as long as it has heat resistance sufficient to withstand the heating conditions required for volatilizing the organic solvent. Examples of such substrates include substrates (e.g., films) made of oriented polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, cellulose, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, and liquid crystal polymer.

[0097] The heating conditions for volatilizing the organic solvent from the varnish composition applied to the substrate can be appropriately set depending on the organic solvent used, etc. The heating conditions may be, for example, 40 to 120°C for 0.1 to 10 minutes.

[0098] When irradiating the first adhesive layer with light, it is preferable to use irradiation light having a wavelength in the range of 150 to 750 nm (for example, ultraviolet light). Light irradiation can be carried out using, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, an LED light source, etc. The cumulative light amount of light irradiation can be set appropriately, but is, for example, 500 to 3000 mJ / cm. 2 It may be.

[0099] The thickness of the first adhesive layer may be 20 μm or less, or may be 15 μm or less, 10 μm or less, 8 μm or less, 5.0 μm or less, 4.5 μm or less, 4.0 μm or less, 3.5 μm or less, 3.0 μm or less, or 2.5 μm or less. By having the thickness of the first adhesive layer be 5 μm or less, the fluidity of component (A) during circuit connection can be further suppressed. The thickness of the first adhesive layer may be, for example, 0.1 μm or more or 0.7 μm or more. Note that, if a portion of the inorganic particles is exposed from the surface of the first adhesive layer, the exposed portion of the inorganic particles is not included in the thickness of the first adhesive layer.

[0100] The adhesive film may be a single layer or multiple layers. That is, it may have only a first adhesive layer, or it may have a first adhesive layer and, in addition, multiple adhesive layers different from the first adhesive layer. In one embodiment, the adhesive film may have a first adhesive layer and a second adhesive layer provided on the first adhesive layer. The second adhesive layer may be, for example, a layer obtained by excluding the radical curable resin component and component (C1) from the components of the first adhesive layer (a layer made of an adhesive composition that does not contain a radical curable resin component as component (B) and a component (C1) as component (an adhesive composition containing a (B) component consisting of a cationic curable resin component and a (C2) component)). The second adhesive layer (second adhesive film) can be obtained by the same method as the first adhesive layer (first adhesive film).

[0101] The thickness of the second adhesive layer can be set appropriately depending on the height of the electrodes of the circuit member to be bonded, etc. From the viewpoint of being able to sufficiently fill the space between the electrodes and seal the electrodes, and thus obtaining better connection reliability, the thickness of the second adhesive layer may be 5 μm or more or 7 μm or more, or may be 30 μm or less, 20 μm or less, 15 μm or less, or 11 μm or less.

[0102] The thickness of the adhesive film (the total thickness of all layers constituting the adhesive film) may be, for example, 5 μm or more or 8 μm or more, and may be 50 μm or less, 40 μm or less, 30 μm or less, or 20 μm or less.

[0103] In one embodiment, the adhesive film may include a first adhesive layer, a second adhesive layer disposed on the first adhesive layer, and a third adhesive layer disposed on the first adhesive layer on the opposite side of the second adhesive layer. The third adhesive layer may be, for example, a layer obtained by excluding component (C1) from the components of the first adhesive layer (i.e., a layer consisting of an adhesive composition (C2) containing component (C) that does not contain component (C1)). The third adhesive layer (third adhesive film) can be obtained by the same method as the first adhesive layer (first adhesive film).

[0104] The thickness of the third adhesive layer may be set appropriately depending on the height of the electrodes of the circuit member to be bonded, etc. The thickness of the third adhesive layer may be 0.2 μm or more and 3.0 μm or less, from the viewpoint of being able to sufficiently fill the space between the electrodes to seal the electrodes and obtain better connection reliability.

[0105] According to the adhesive film of this embodiment, it is possible to suppress localization of inorganic particles even when an external force is applied. [Example]

[0106] The present disclosure will be described in more detail below with reference to examples, although the present disclosure is not limited to these examples.

[0107] [Resin synthesis] (Example 1-1) Synthesis of Resin C1-1a A flask equipped with a stirrer, condenser, thermometer, and gas inlet tube was charged with 400.00 g of methyl ethyl ketone as a solvent, 200.00 g of toluene, and 393.26 g of phenoxy resin (FX-293, manufactured by Nippon Steel Chemical & Material Co., Ltd.) and stirred until uniformly dissolved. The temperature was then raised to 60°C, and MOI-EG (2-(2-methacryloyloxyethyloxy)ethyl isocyanate, R 1 6.70 g of a compound represented by formula (2) in which x is a methyl group, x is 2, and y is 2 (manufactured by Showa Denko K.K.) and 0.04 g of dioctyltin dilaurate as a catalyst were added, and the contents of the flask were stirred while blowing in nitrogen, and the reaction was carried out for 2 hours to obtain the target resin C1-1a. 1 H-NMR was measured, and the modification rate was calculated from the integral value of the peak in the spectrum obtained, and the modification rate of Resin C1-1a was found to be 3%.

[0108] (Example 1-2) Synthesis of Resin C1-1b Resin C1-1b was obtained in the same manner as in Example 1-1, except that the amount of phenoxy resin charged was changed to 388.91 g and the amount of MOI-EG charged was changed to 11.05 g. The modification rate of Resin C1-1b was 5%.

[0109] (Example 1-3) Synthesis of Resin C1-1c Resin C1-1c was obtained in the same manner as in Example 1-1, except that the amount of phenoxy resin charged was changed to 384.66 g and the amount of MOI-EG charged was changed to 15.30 g. The modification rate of Resin C1-1c was 7%.

[0110] (Example 1-4) Synthesis of Resin C1-1d Resin C1-1d was obtained in the same manner as in Example 1-1, except that the amount of phenoxy resin charged was changed to 380.50 g and the amount of MOI-EG charged was changed to 19.46 g. The modification rate of Resin C1-1d was 9%.

[0111] (Example 1-5) Synthesis of Resin C1-1e Resin C1-1e was obtained in the same manner as in Example 1-1, except that the amount of phenoxy resin charged was changed to 372.45 g and the amount of MOI-EG charged was changed to 27.51 g. The modification rate of Resin C1-1e was 13%.

[0112] (Example 1-6) Synthesis of Resin C1-1f Resin C1-1f was obtained in the same manner as in Example 1-1, except that the amount of phenoxy resin charged was changed to 364.73 g and the amount of MOI-EG charged was changed to 35.23 g. The modification rate of Resin C1-1f was 17%.

[0113] (Example 2-1) Synthesis of Resin C1-2a A flask equipped with a stirrer, condenser, thermometer, and gas inlet tube was charged with 400.00 g of methyl ethyl ketone and 200.00 g of toluene as solvents, and 396.16 g of phenoxy resin (YP-70, manufactured by Nippon Steel Chemical & Material Co., Ltd.) and stirred until uniformly dissolved. The temperature was then raised to 60°C, and 3.80 g of MOI-EG (2-(2-methacryloyloxyethyloxy)ethyl isocyanate, manufactured by Showa Denko K.K.) and 0.04 g of dioctyltin dilaurate as a catalyst were added. The contents of the flask were stirred while blowing in nitrogen, and the reaction was carried out for 2 hours to obtain the target resin C1-2a. As described above, for resin C1-2a, 1 H-NMR was measured, and the modification rate was calculated from the integral value of the peak in the spectrum obtained, and the modification rate of Resin C1-2a was found to be 1%.

[0114] (Example 2-2) Synthesis of Resin C1-2b Resin C1-2b was obtained in the same manner as in Example 2-1, except that the amount of phenoxy resin charged was changed to 388.78 g and the amount of MOI-EG charged was changed to 11.18 g. The modification rate of Resin C1-2b was 3%.

[0115] (Example 2-3) Synthesis of Resin C1-2c Resin C1-2c was obtained in the same manner as in Example 2-1, except that the amount of phenoxy resin charged was changed to 381.66 g and the amount of MOI-EG charged was changed to 18.30 g. The modification rate of Resin C1-2c was 5%.

[0116] (Example 2-4) Synthesis of Resin C1-2d Resin C1-2d was obtained in the same manner as in Example 2-1, except that the amount of phenoxy resin charged was changed to 374.81 g and the amount of MOI-EG charged was changed to 25.15 g. The modification rate of Resin C1-2d was 7%.

[0117] (Example 2-5) Synthesis of Resin C1-2e Resin C1-2e was obtained in the same manner as in Example 2-1, except that the amount of phenoxy resin charged was changed to 368.19 g and the amount of MOI-EG charged was changed to 31.77 g. The modification rate of Resin C1-2e was 9%.

[0118] [Preparation of the first adhesive layer (first adhesive film) and the second adhesive layer (second adhesive film)] In the preparation of these, the following materials were used.

[0119] (A) Component: Inorganic particles A-1: TFM-S05P (Ag-coated Si core particles, manufactured by Toyo Aluminum Co., Ltd., particle size: 6 μm (D50)) A-2: R805 (silica fine particles, manufactured by Evonik Industries AG) A-3: SE2050 (silica particles, manufactured by Admatechs Co., Ltd.)

[0120] (B) Component: Curable resin component Component (B1): radical polymerizable compound B1-1: VR-90 (bisphenol A type epoxy (meth)acrylate (bifunctional) (vinyl ester resin), manufactured by Showa Denko K.K.) Component (B2): Radical polymerization initiator (B2L) component: Photoradical polymerization initiator B2L-1: Omnirad907 (2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, manufactured by IGM Resins BV) Component (B3): Cationic polymerizable compound B3-1: jER828 (bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation) Component (B4): cationic polymerization initiator (B4H) component: thermal cationic polymerization initiator B4H-1: Benzyl(4-hydroxyphenyl)methylsulfonium hexafluoroantimonate (Tokyo Chemical Industry Co., Ltd.) B4H-2: 4-Hydroxyphenyldimethylsulfonium methylsulfate (Tokyo Chemical Industry Co., Ltd.)

[0121] (C) Component: Thermoplastic resin Component (C1): a phenoxy resin in which at least a portion of the hydroxy groups has been modified with a group represented by formula (1) C1-1a: Resin of Example 1-1 (modification rate: 3%) C1-1b: Resin of Example 1-2 (modification rate: 5%) C1-1c: Resin of Example 1-3 (modification rate: 7%) C1-1d: Resin of Example 1-4 (modification rate: 9%) C1-1e: Resin of Example 1-5 (modification rate: 13%) C1-1f: Resin of Example 1-6 (modification rate: 17%) C1-2a: Resin of Example 2-1 (modification rate: 1%) C1-2b: Resin of Example 2-2 (modification rate: 3%) C1-2c: Resin of Example 2-3 (modification rate: 5%) C1-2d: Resin of Example 2-4 (modification rate: 7%) C1-2e: Resin of Example 2-5 (modification rate: 9%) Component (C2): Thermoplastic resin other than component (C1) C2-1: FX-293 (phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) C2-2: YP-70 (phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) C2-3: ZX1356-2 (phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) C2-4: FX-310 (phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) C2-5: TOPR-300 (phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.)

[0122] Component (D): Coupling agent E-1: KBM-403 (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0123] <Preparation of First Adhesive Film (First Adhesive Layer)> The materials shown in Table 1 were mixed in the composition ratios shown in Table 1 (the values ​​in Table 1 indicate the non-volatile content), and each adhesive varnish was diluted with an organic solvent (the reaction solvent used in producing component C1). The resulting mixture was then applied to a 50 μm-thick release-treated PET (polyethylene terephthalate) film as a substrate, and the organic solvent was dried to obtain adhesive layers 1a-1k containing each component. The adhesive layers 1a-1k had a thickness of 2 μm after drying. The adhesive layers 1a-1k were then irradiated with light (UV irradiation: metal halide lamp, cumulative light intensity: 1900-2300 mJ / cm). 2 ) to obtain first adhesive films (first adhesive layers) 1A to 1K. The first adhesive films 1A to 1K contain a cured product of a photocurable resin component and a thermosetting resin component. The first adhesive films (first adhesive layers) 1A to 1K had a thickness of 2 μm.

[0124] [Table 1]

[0125] <Preparation of second adhesive film (second adhesive layer)> The materials shown in Table 2 were mixed in the composition ratios shown in Table 2 (the values ​​in Table 2 indicate the non-volatile content), to obtain an adhesive varnish diluted with an organic solvent. This was then coated onto a 50 μm thick release-treated PET (polyethylene terephthalate) film as a substrate, and the organic solvent was dried to obtain a second adhesive film (second adhesive layer) 2A. The thickness of the second adhesive film 2A after drying was 9 μm.

[0126] [Table 2]

[0127] (Examples 3-1 to 3-10 and Comparative Example 3-1) [Preparation of adhesive film] Using the first adhesive film and second adhesive film produced above, adhesive films were produced with the configurations shown in Table 3. First adhesive films 1A to 1K were each laminated to second adhesive film 2A while applying a temperature of 50 to 60°C, thereby obtaining adhesive films of Examples 3-1 to 3-10 and Comparative Example 3-1 with the configurations shown in Table 3.

[0128] [Evaluation of the fluidity of inorganic particles] The adhesive films of Examples 3-1 to 3-10 and Comparative Example 3-1 were cut to a predetermined size (13 mm long x 13 mm wide x 11 μm thick) to prepare evaluation films. The evaluation films were then attached to a copper-wiring-equipped glass epoxy substrate (substrate thickness: 420 μm, copper wiring thickness: 2 μm), and a semiconductor chip with gold bumps (chip size: 10.2 mm long x 10.2 mm wide x 0.55 mm thick, bump height: approximately 10 μm, number of bumps: 184) was mounted using a flip mounter (product name: FCB3-3, manufactured by Panasonic Corporation). The mounting conditions were a pressure head temperature of 300°C, a pressure time of 10 seconds, and a pressure of 30 MPa. This produced a semiconductor device in which a copper-wiring-equipped glass epoxy substrate and a semiconductor chip with gold bumps were daisy-chain connected. For the fabricated semiconductor device, the semiconductor chip was peeled off from the substrate using a shear force measuring device, and the fluidity (degree of localization) of the inorganic particles A-1 in the evaluation film remaining on the semiconductor chip was observed and evaluated based on the following criteria. Grade A: The area of ​​the semiconductor chip where inorganic particles A-1 are not present is less than 1%. Grade B: The area of ​​the semiconductor chip where inorganic particles A-1 are not present is 1% or more but less than 15%. C rating: The area of ​​the semiconductor chip where inorganic particles A-1 are not present is 15% or more.

[0129] [Table 3]

[0130] As shown in Table 3, the adhesive films of Examples 3-1 to 3-10, which had adhesive layers containing a specified resin as a thermoplastic resin, had fewer areas where inorganic particles A-1 were not present, compared to the adhesive film of Comparative Example 3-1, which had an adhesive layer that did not contain the specified resin. From the above, it was confirmed that the adhesive film of the present disclosure can suppress localization of inorganic particles even when an external force is applied.

Claims

1. At least a portion of the hydroxy groups in the phenoxy resin are modified with a group represented by the following formula (1): resin. 【Chemistry 1】 [In formula (1), R １ represents a hydrogen atom or a methyl group, x represents an integer of 2 to 6, and y represents an integer of 2 to 6. * represents the bonding position to the oxygen atom derived from the hydroxy group.]

2. the modification rate of the group represented by formula (1) relative to the hydroxy group of the phenoxy resin is 0.5 to 50%; The resin of claim 1.

3. Contains inorganic particles, a curable resin component, and a thermoplastic resin, The thermoplastic resin comprises the resin of claim 1. Adhesive composition.

4. the curable resin component contains a radical polymerizable compound and a radical polymerization initiator; The adhesive composition according to claim 3.

5. The curable resin component further contains a cationic polymerizable compound and a cationic polymerization initiator. The adhesive composition according to claim 4.

6. The cationically polymerizable compound includes an epoxy resin. The adhesive composition according to claim 5.

7. An adhesive layer comprising the adhesive composition according to any one of claims 3 to 6 or a cured product thereof. Adhesive film.

8. For circuit connection, The adhesive film of claim 7.

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