Adhesive film for circuit connection, circuit connection structure, and method for manufacturing the same.

Abstract

To provide an adhesive film for circuit connection that is able to prevent the localization of conductive particles even under heat and pressure, while also reducing connection resistance.SOLUTION: An adhesive film 10 for circuit connection comprises: a first adhesive layer 1 containing conductive particles 4 and a thermoplastic resin; and a second adhesive layer 2 provided on the first adhesive layer 1. The thermoplastic resin includes a resin in which at least some of hydroxy groups in a phenoxy resin are modified with a group represented by formula (1) or formula (1A).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to an adhesive film for circuit connections, a circuit connection structure, and a method for manufacturing the same. [Background technology]

[0002] Conventionally, anisotropic conductive films, in which conductive particles are dispersed in an adhesive film, have been used for connecting liquid crystal displays to tape carrier packages (TCPs), flexible printed circuit boards (FPCs) to TCPs, or FPCs to printed wiring boards. Specifically, a circuit connection structure can be obtained by bonding circuit components together through circuit connection portions formed by the circuit connection adhesive film, and by electrically connecting electrodes on the circuit components via the conductive particles in the circuit connection portions. Furthermore, when mounting semiconductor silicon chips onto substrates, so-called chip-on-glass (COG) mounting, in which semiconductor silicon chips are directly mounted onto the substrate, has been adopted as an alternative to conventional wire bonding, and anisotropic conductive films are also used in COG mounting (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-054288 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, with anisotropic conductive films, it is difficult to control the fluidity during connection. When connecting a semiconductor chip to a substrate (when heat and external force are applied), adhesive components may leak out from the circuit connection area, resulting in the localization of conductive particles within the circuit connection area. When conductive particles localize within the circuit connection area, they can accumulate between adjacent circuits, forming a short circuit and potentially leading to malfunction.

[0005] Further, if the fluidity of the anisotropic conductive film is insufficient, the resin discharging property between connected circuits may be degraded, which may cause an increase in connection resistance.

[0006] Accordingly, the main object of the present disclosure is to provide an adhesive film for circuit connection that can suppress localization of conductive particles even when heat and external force are applied, and can reduce connection resistance. [Means for Solving the Problem]

[0007] The inventors of the present invention conducted studies to solve the above problems, and found that by using a specific resin as the thermoplastic resin, localization of conductive particles can be suppressed even when an external force is applied, and furthermore, connection resistance can be reduced, thereby completing the invention of the present disclosure.

[0008] The present disclosure provides the adhesive film for circuit connection according to any one of [1] to [9], the method for producing a circuit-connected structure according to

[10] , and the circuit-connected structure according to

[11] . [1] An adhesive film for circuit connection, comprising: a first adhesive layer containing conductive particles and a thermoplastic resin; and a second adhesive layer provided on the first adhesive layer, wherein the thermoplastic resin includes a resin obtained by modifying at least a part of hydroxy groups in a phenoxy resin with a group represented by the following formula (1) or the following formula (1A). [Chemical Formula] [In formula (1), R 1 represents a hydrogen atom or a methyl group, x represents an integer of 2 to 6, y represents an integer of 1 to 6, and * represents a bonding position that bonds to an oxygen atom derived from a hydroxy group.]] [Chemical Formula] [In formula (1A), R 1x, y, and * are the same as above. *1 and *2 indicate the bonding positions with carbon atoms of other radical polymerizable groups. [2] The circuit connection adhesive film according to [1], wherein the thickness of the first adhesive layer is 5 μm or less, and the ratio of the thickness of the first adhesive layer to the average particle size of the conductive particles is 0.50 or more. [3] The circuit connection adhesive film according to [1] or [2], wherein the first adhesive layer further contains a cured product of a photocurable resin component and a first thermosetting resin component, and the second adhesive layer further contains a second thermosetting resin component. [4] The circuit connection adhesive film according to [3], wherein the photocurable resin component comprises a radical polymerizable compound and a photoradical polymerization initiator. [5] The circuit connection adhesive film according to [3] or [4], wherein the first thermosetting resin component and the second thermosetting resin component each contain a cationic polymerizable compound and a thermal cationic polymerization initiator. [6] The circuit connection adhesive film according to [5], wherein the cationic polymerizable compound is at least one selected from the group consisting of oxetane compounds and alicyclic epoxy compounds. [7] The circuit connection adhesive film according to [5] or [6], wherein the thermal cationic polymerization initiator is a salt compound having an anion containing boron as a constituent element. [8] The circuit connection adhesive film according to any one of [3] to [7], further comprising a third adhesive layer containing a third thermosetting resin component, provided on the side of the first adhesive layer opposite to the second adhesive layer. [9] The circuit connection adhesive film according to [8], wherein the third thermosetting resin component comprises a cationic polymerizable compound and a thermal cationic polymerization initiator.

[10] A method for manufacturing a circuit connection structure, comprising the steps of interposing a circuit connection adhesive film according to any of [1] to [9] between a first circuit member having a first electrode and a second circuit member having a second electrode, and then heat-pressing the first circuit member and the second circuit member to electrically connect the first electrode and the second electrode to each other.

[11] A circuit connection structure comprising a first circuit member having a first electrode, a second circuit member having a second electrode, and a circuit connection portion disposed between the first circuit member and the second circuit member and electrically connecting the first electrode and the second electrode to each other, wherein the circuit connection portion includes a cured product of the circuit connection adhesive film described in [1] to [9]. [Effects of the Invention]

[0009] This disclosure provides for a circuit connection adhesive film that can suppress the localization of conductive particles and reduce connection resistance even when heat and external force are applied. Furthermore, this disclosure provides for a circuit connection structure using such a circuit connection adhesive film and a method for manufacturing the same. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic cross-sectional view showing one embodiment of an adhesive film for circuit connection. [Figure 2] Figure 2 is a schematic cross-sectional view showing one embodiment of a circuit connection structure. [Figure 3] Figure 3 is a schematic cross-sectional view showing one embodiment of a method for manufacturing a circuit connection structure. Figures 3(a) and 3(b) are schematic cross-sectional views showing each step of the process. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described in detail below. However, this disclosure is not limited to the embodiments described below.

[0012] In this specification, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper or lower limit of one stage of the numerical range may be replaced with the upper or lower limit of another stage of the numerical range. Also, in numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. Furthermore, the upper and lower limits described individually can be combined in any way. In the notation "A~B" for a numerical range, the numbers A and B at both ends are included in the numerical range as the lower and upper limits, respectively. In this specification, for example, the description "10 or more" means "10" and "numbers greater than 10," and this applies even if the numbers are different. Also, for example, the description "10 or less" means "10" and "numbers less than 10," and this applies even if the numbers are different.

[0013] In this specification, "(meth)acrylate" means at least one of acrylate and its corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylic acid." Furthermore, "A or B" means that either A or B is included, or both are included.

[0014] The materials exemplified below may be used individually or in combination of two or more, unless otherwise specified. The content of each component in the composition refers to the total amount of any multiple substances present in the composition, unless otherwise specified, if multiple substances corresponding to each component exist in the composition.

[0015] [Adhesive film for circuit connections] Figure 1 is a schematic cross-sectional view showing one embodiment of an adhesive film for circuit connection. The adhesive film 10 for circuit connection shown in Figure 1 (hereinafter sometimes simply referred to as "adhesive film 10") comprises a first adhesive layer 1 containing conductive particles 4 and an adhesive component 5 containing a predetermined resin as a thermoplastic resin, and a second adhesive layer 2 provided on the first adhesive layer 1. In the adhesive film 10, there may be a first region which is a region formed from the first adhesive film (first adhesive layer 1), and a second region which is a region formed from the second adhesive film (second adhesive layer 2) provided adjacent to the first region. In other words, the adhesive film 10 can also be said to comprise a first region containing an adhesive component 5 containing a predetermined resin as a thermoplastic resin, and a second region provided adjacent to the first region.

[0016] The adhesive film 10 has conductive particles 4 dispersed in the first adhesive layer 1. Therefore, the adhesive film 10 may be an anisotropically conductive adhesive film for circuit connection (anisotropically conductive adhesive film). The adhesive film 10 may be interposed between a first circuit member having a first electrode and a second circuit member having a second electrode, and used to electrically connect the first electrode and the second electrode to each other by thermocompression bonding the first and second circuit members.

[0017] <First adhesive layer> The first adhesive layer 1 contains conductive particles 4 (hereinafter sometimes referred to as "component (A)") and a thermoplastic resin (hereinafter sometimes referred to as "component (B)"). The first adhesive layer 1 may further contain a cured product of a photocurable resin component (hereinafter sometimes referred to as "component (C)") and a thermosetting resin component (hereinafter sometimes referred to as "component (D)"). The first adhesive layer 1 can be obtained, for example, by irradiating a composition layer consisting of a composition containing components (A), (B), (C), and (D) with light energy to polymerize the components contained in component (C) and cure component (C). The first adhesive layer 1 may contain component (A), cured products of components (B) and (C), and an adhesive component 5 containing component (D). The cured product of component (C) may be a cured product in which component (C) has been completely cured, or a cured product in which a part of component (C) has been cured. Component (D) is a component that can flow when the circuit is connected, and may be, for example, an uncured curable resin component.

[0018] (A) Component: Conductive particles Component (A) is not particularly limited as long as it is a conductive particle, and may be metal particles composed of metals such as Au, Ag, Pd, Ni, Cu, or solder, or conductive carbon particles composed of conductive carbon. Component (A) may also be a coated conductive particle comprising a core containing non-conductive glass, ceramic, or plastic (such as polystyrene), and a coating layer containing the above-mentioned metal or conductive carbon that covers the core. Among these, component (A) is preferably a coated conductive particle comprising a core containing metal particles or plastic formed from a heat-meltable metal, and a coating layer containing metal or conductive carbon that covers the core. Since such coated conductive particles can be easily deformed by heating or pressurizing the cured product of the thermosetting resin component, for example, when electrically connecting opposing electrodes of a semiconductor chip and a substrate, the contact area between the electrodes and component (A) can be increased, and the conductivity between the electrodes can be further improved.

[0019] Component (A) may be insulating coated conductive particles comprising the above-mentioned metal particles, conductive carbon particles, or coated conductive particles, and an insulating layer that covers the surface of the particles and contains an insulating material such as resin. When component (A) is insulating coated conductive particles, even if the content of component (A) is high, the presence of an insulating layer on the surface of the particles can suppress the occurrence of short circuits due to contact between components (A), and can also improve the insulation between adjacent electrode circuits in semiconductor chips and substrates.

[0020] (A) The maximum particle size of component (A) 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 component (A) may be 1 μm or more, 2 μm or more, or 2.5 μm or more. From the viewpoint of excellent dispersibility and conductivity, the maximum particle size of component (A) may be 20 μm or less, 10 μm or less, or 5 μm or less. In this specification, the particle size of any 300 conductive particles (pcs) is measured by observation using a scanning electron microscope (SEM), and the largest value obtained is taken as the maximum particle size of component (A). If component (A) has protrusions or is not spherical, the particle size of component (A) is taken as the diameter of the circle circumscribing the conductive particle in the SEM image.

[0021] The average particle size of component (A) may be 1 μm or more, 2 μm or more, or 2.5 μm or more, from the viewpoint of excellent dispersibility and conductivity. The average particle size of component (A) may be 20 μm or less, 10 μm or less, or 5 μm or less, from the viewpoint of excellent dispersibility and conductivity. In this specification, the particle size of any 300 conductive particles (pcs) is measured by observation using a scanning electron microscope (SEM), and the simple average value of the obtained particle sizes is taken as the average particle size.

[0022] In the first adhesive layer 1, it is preferable that component (A) is uniformly dispersed. From the viewpoint of obtaining stable connection resistance, the particle density of component (A) in the adhesive film 10 should be 100 particles / mm². 2 More than 1000 pieces / mm 2 More than 3000 pieces / mm 2 Above, or 5000 pieces / mm2 As described above. The particle density of component (A) in the adhesive film 10 may be 100000 particles / mm from the viewpoint of improving insulation between adjacent electrodes 2 or less, 70000 particles / mm 2 or less, 50000 particles / mm 2 or less, or 30000 particles / mm 2 or less.

[0023] The content of component (A), based on the total mass of the first adhesive layer, may be 1% by mass or more, 5% by mass or more, or 10% by mass or more from the viewpoint of further improving conductivity. The content of component (A), based on the total mass of the first adhesive layer, may be 80% by mass or less, 60% by mass or less, or 40% by mass or less from the viewpoint of easily suppressing short circuits. When the content of component (A) is within the above range, the effect of the present disclosure tends to be remarkably exhibited. The content of component (A) in the composition or composition layer (based on the total mass of the composition or composition layer) may be the same as the above range.

[0024] Component (B): Thermoplastic resin Component (B) includes the above resin in which at least part of the hydroxy groups in the phenoxy resin are modified with a group represented by formula (1) or formula (1A) (hereinafter may be referred to as "component (B1)"). Component (B1) is not included in component (C1) (radically polymerizable compound) described later. In addition to component (B1), component (B) may further contain a thermoplastic resin other than component (B1) (hereinafter may be referred to as "component (B2)").

[0025] • Component (B1): A resin in which at least part of the hydroxy groups in the phenoxy resin are modified with a group represented by formula (1) or formula (1A) A resin in which at least some of the hydroxyl groups in a phenoxy resin are modified with a group represented by formula (1) (hereinafter sometimes referred to as "resin (1)") 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 the 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). Resin (1) is a component that can act as a thermoplastic resin.

[0026] By including component (B1) as component (B) in the adhesive composition, it becomes possible to form an adhesive film for circuit connections that can suppress the localization of conductive particles even when heat and external force are applied. The reason for this effect is not entirely clear, but the inventors speculate that the (meth)acryloyl groups in the group represented by formula (1) crosslink intermolecularly or intramolecularly due to light irradiation (e.g., ultraviolet light) or heat, improving the toughness of the film and effectively suppressing the proximity of conductive particles to each other. Furthermore, this effect tends to be further enhanced when component (B) includes components (B1) and (B2).

[0027] [ka]

[0028] In formula (1), R 1 x represents a hydrogen atom or a methyl group. x represents an integer from 2 to 6, and may be 2 to 5, 2 to 4, or 2 to 3. y represents an integer from 1 to 6, and may be 1 to 5, 1 to 4, 1 to 3, or 1 to 2. * indicates a bonding position with an oxygen atom derived from a hydroxyl group.

[0029] [ka]

[0030] In formula (2), R 1x and y are equivalent to those stated above.

[0031] The compound represented by formula (2) can be obtained by known methods such as the phosgene method using an amino alcohol having the corresponding ether linkage, or by using a commercially available product. For example, the compound represented by formula (2) can be obtained by reacting an amino alcohol having an ether linkage, such as 2-(2-aminoethoxy)ethanol or 2-(2-(2-aminoethoxy)ethoxy)ethanol, with an acid chloride such as (meth)acrylate chloride, and then reacting it with phosgene. A commercially available product is Karenz® MOI(R 1 A compound represented by formula (2) where is a methyl group, x is 2, and y is 1 (manufactured by Showa Denko Corporation), Karens (registered trademark) AOI (R 1 A compound represented by formula (2) where is a hydrogen atom, x is 2, and y is 1 (manufactured by Showa Denko Corporation), Karens (registered trademark) MOI-EG(R 1 Examples include compounds represented by formula (2), where is a methyl group, x is 2, and y is 2 (manufactured by Showa Denko Corporation).

[0032] Phenoxy resins can be obtained, for example, by reacting a polyvalent phenol compound with a polyvalent epoxy compound. Such phenoxy resins typically have a structure in which an aliphatic hydroxyl group is formed at the bond between an aromatic hydroxyl group and an epoxy group (for example, a structure derived from formula (X) below). Among such phenoxy resins, those obtained by reacting bisphenols with diglycidyl etherified bisphenols are readily available and common.

[0033] Examples of polyvalent phenol compounds include bisphenol A and bisphenol F. Examples of polyvalent epoxy compounds include bisphenol A diglycidyl ether and bisphenol F diglycidyl ether.

[0034] Phenoxy resins can be polyhydroxy polyethers (thermoplastic resins) synthesized from bisphenols and epichlorohydrin. Such phenoxy resins typically have a structure derived from the following formula (X) (* indicates the bond position) derived from epichlorohydrin, where the hydroxyl group of the phenoxy resin is a methine carbon atom (C A It is connected to ).

[0035] [ka]

[0036] Commercially available phenoxy resins can be used. Examples of commercially available phenoxy resins include FX-293, YP-70, ZX1356-2, FX-310, TOPR-300 (all manufactured by Nippon Steel Chemical & Material Co., Ltd.), PKHA, PKHB, PKHC, PKHH, PKHJ, PKFE, PKHP-200 (all manufactured by Huntsman International LLC.), jER1256, jER4250, jER4275 (all manufactured by Mitsubishi Chemical Corporation), H360, EXA-192 (all manufactured by DIC Corporation), and others.

[0037] The modification rate of the group represented by formula (1) to the hydroxyl group of the phenoxy resin may be 0.5 to 50%. When the modification rate is 0.5% or higher, the localization of conductive particles tends to be sufficiently suppressed. When the modification rate is 50% or lower, the connection resistance of the circuit connection tends to be better. The modification rate may be 1.0% or higher, 3.0% or higher, or 5.0% or higher, and may be 40% or lower, 30% or lower, 20% or lower, 15% or lower, or 10% or lower.

[0038] Here, the modification rate of the group represented by formula (1) to the hydroxyl group of the phenoxy resin is, for example, for a resin modified with the group represented by formula (1), 1The ¹H-NMR spectrum can be measured and the integral value of the peaks in the resulting spectrum can be calculated. The resin modified with the group represented by formula (1) has a structure derived from formula (X) above, as well as a structure derived from formula (Y) below (* indicates the bond position). In the structure derived from formula (X), the methine carbon atom (C A ) hydrogen atom (H A The chemical shift value attributed to (based on the methyl group of tetramethylsilane (TMS)) is usually observed to be δ4.2-4.4. On the other hand, in the structure derived from formula (Y), the methine carbon atom (C B ) hydrogen atom (H B The chemical shift value attributed to (based on the methyl group of tetramethylsilane (TMS)) is H A The chemical shift value attributable to (H) is shifted at a lower magnetic field and is usually observed at δ5.2~6.0. Therefore, hydrogen atoms (H) A The integral value of the peak attributed to ) and the hydrogen atom (H B The sum of the integral values ​​of the peaks attributed to the hydrogen atom (H B The percentage of the integral value of the peaks attributed to (H) B The integral value of / (H A The integral value of +H B The rate of modification can be determined by calculating the integral value of () × 100 (%). Furthermore, by plotting the relationship between the amount of compound represented by formula (2) added when reacting phenoxy resin and the compound represented by formula (2) and the rate of modification, a calibration curve can be created, thereby deriving the rate of modification from the amount of compound represented by formula (2) added.

[0039] [ka]

[0040] Resin (1) 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.

[0041] The amount of compound represented by formula (2) added can be arbitrarily set so that the rate of modification of the group represented by formula (1) to the hydroxyl groups of the phenoxy resin reaches a predetermined value. The amount of compound represented by formula (2) added may be 0.5 to 50 mol% relative to the total molar amount of hydroxyl groups in the phenoxy resin. The amount of compound represented by formula (2) added may be 1.0 mol% or more, 3.0 mol% or more, or 5.0 mol% or more, and may also be 40 mol% or less, 30 mol% or less, 20 mol% or less, 15 mol% or less, or 10 mol% or less, relative to the total molar amount of hydroxyl groups in the phenoxy resin.

[0042] The organic solvent can be used without particular limitations as long as it can dissolve the phenoxy resin and the compound represented by formula (2). Examples of organic solvents 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; carbonate esters such as ethylene carbonate and propylene carbonate; and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone (NMP).

[0043] A urethane catalyst can be used as the catalyst. Examples of catalysts 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 n-propyl zirconate, n-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).

[0044] The reaction temperature between 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 holding at the above reaction temperature may be, for example, 0.1 to 12 hours, 8 hours or less, 6 hours or less, or 4 hours or less.

[0045] In the first adhesive layer 1, the (meth)acryloyl group of the group represented by formula (1) in the resin (1) may react with the (meth)acryloyl group of another group represented by formula (1) in the resin (1) or with the radical polymerizable group of component (C1) described later (radical polymerization proceeds) to form a bond between the carbon atom of the (meth)acryloyl group of the group represented by formula (1) in the resin (1) and the carbon atom of the other radical polymerizable group (such as the (meth)acryloyl group of another group represented by formula (1) in the resin (1), or the radical polymerizable group of component (C1) described later). In other words, some or all of the groups represented by formula (1) in the resin (1) may be converted to the group represented by formula (1A).

[0046] [ka]

[0047] In formula (1A), R 1 , x, y, and * are the same as above. *1 and *2 indicate bonding positions with carbon atoms of other radical polymerizable groups.

[0048] The content of component (B1) may be 20-100% by mass, 30-100% by mass, 40-100% by mass, 50-100% by mass, 60-100% by mass, 70-100% by mass, or 80-100% by mass, based on the total mass of component (B).

[0049] • (B2) component: Thermoplastic resin other than (B1) component Examples of component (B2) include phenoxy resin, polyester resin, polyamide resin, polyurethane resin, polyester urethane resin, and acrylic rubber that have not been modified with a group represented by formula (1) or formula (1A). Among these, component (B2) may be, for example, a phenoxy resin that has not been modified with a group represented by formula (1) or formula (1A).

[0050] The content of component (B2) may be, for example, 0-80% by mass, 0-70% by mass, 0-60% by mass, 0-50% by mass, 0-40% by mass, 0-30% by mass, or 0-20% by mass, based on the total mass of component (B).

[0051] The content of component (B) may be 1% by mass or more, 5% by mass or more, or 10% by mass or more, and may be 50% by mass or less, 40% by mass or less, or 30% by mass or less, based on the total mass of the adhesive composition. 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.

[0052] (C) Component: Photocurable resin component The first adhesive layer 1 may further contain a cured product of component (C). The curing of component (C) suppresses the fluidity of conductive particles during circuit connection while suppressing a decrease in the exclaveability of the resin. Component (C) is not particularly limited as long as it is a resin component that cures by light irradiation, but if component (D) is a resin component that has cationic curability, it may be a resin component that has radical curability from the viewpoint of having better connection resistance. Component (C) may include, for example, a radical polymerizable compound (hereinafter sometimes referred to as "component (C1)") and a photoradical polymerization initiator (hereinafter sometimes referred to as "component (C2)"). Component (C) may be a component consisting of component (C1) and component (C2).

[0053] • (C1) component: radical polymerizable compound Component (C1) is a compound whose polymerization or crosslinking proceeds by radicals generated by irradiation of component (C2) with light (e.g., ultraviolet light). Component (C1) may be a monomer, or a polymer (or oligomer) formed by the polymerization of one or more monomers.

[0054] Component (C1) is a compound having radical polymerizable groups that react with radicals. Examples of radical polymerizable groups include (meth)acryloyl groups, vinyl groups, allyl groups, styryl groups, alkenyl groups, alkenylene groups, maleimide groups, etc. The number of radical polymerizable groups (number of functional groups) in component (C1) may be 2 or more from the viewpoint of easily obtaining the desired melt viscosity after polymerization, further improving the effect of reducing connection resistance, and providing superior connection reliability, and may be 10 or less from the viewpoint of suppressing curing shrinkage during polymerization. Furthermore, in order to balance the crosslinking density and curing shrinkage, in addition to compounds with a number of radical polymerizable groups within the above range, compounds with a number of radical polymerizable groups outside the above range may also be used.

[0055] Component (C1) may, for example, include a polyfunctional (two- or more functional) (meth)acrylate from the viewpoint of suppressing the flow of conductive particles. The polyfunctional (two- or more functional) (meth)acrylate may be a bifunctional (meth)acrylate, and the bifunctional (meth)acrylate may be a bifunctional aromatic (meth)acrylate.

[0056] 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, polypropylene glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, and 1,3-butane. Aliphatic (meth)acrylates such as diol 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, glycerin di(meth)acrylate, tricyclodecanedimethanol (meth)acrylate, and ethoxylated 2-methyl-1,3-propanediol di(meth)acrylate;Aromatic (meth)acrylates such as ethoxylated bisphenol A type di(meth)acrylate, propoxylated bisphenol A type di(meth)acrylate, ethoxylated propoxylated bisphenol A type di(meth)acrylate, ethoxylated bisphenol F type di(meth)acrylate, propoxylated bisphenol F type di(meth)acrylate, ethoxylated propoxylated bisphenol F type di(meth)acrylate, ethoxylated fluorene type di(meth)acrylate, propoxylated fluorene type di(meth)acrylate, ethoxylated propoxylated fluorene type di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, ethoxylated propoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol Examples include aliphatic (meth)acrylates such as methylmethylol tri(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, 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 tetraacrylate, and dipentaerythritol hexa(meth)acrylate; and aromatic epoxy (meth)acrylates such as bisphenol-type epoxy (meth)acrylate, phenol novolac-type epoxy (meth)acrylate, and cresol novolac-type epoxy (meth)acrylate.

[0057] The content of polyfunctional (two or more functional) (meth)acrylate may be, for example, 40-100% by mass, 50-100% by mass, or 60-100% by mass, based on the total mass of component (C1), from the viewpoint of achieving both a reduction in connection resistance and suppression of particle flow.

[0058] Component (C1) may further contain monofunctional (meth)acrylates in addition to polyfunctional (bifunctional or more) (meth)acrylates. Examples of monofunctional (meth)acrylates 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, 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)acryloyl Aliphatic (meth)acrylates such as methyl 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, phenoxymethyl Aromatic (meth)acrylates such as ethylene glycol (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, phenoxypolypropylene 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 include (meth)acrylates having epoxy groups such as glycidyl (meth)acrylate, (meth)acrylates having alicyclic epoxy groups such as 3,4-epoxycyclohexylmethyl (meth)acrylate, and (meth)acrylates having oxetanyl groups such as (3-ethyloxetan-3-yl)methyl (meth)acrylate.

[0059] The content of monofunctional (meth)acrylate may be, for example, 0-60% by mass, 0-50% by mass, or 0-40% by mass, based on the total mass of component (C1).

[0060] The cured product of component (C) may have polymerizable groups that react with a factor other than a radical. The polymerizable groups that react with a factor other than a radical may be cationic polymerizable groups that react with a cation. Examples of cationic polymerizable groups include epoxy groups such as glycidyl groups, alicyclic epoxy groups such as epoxycyclohexylmethyl groups, and oxetanyl groups such as ethyloxetanylmethyl groups. Polymerizable groups that react with a factor other than a radical can be introduced into the cured product of component (C) by using a (meth)acrylate having polymerizable groups that react with a factor other than a radical, such as an epoxy group (meth)acrylate, an alicyclic epoxy group (meth)acrylate, or an oxetanyl group (meth)acrylate, as component (C1). The mass ratio of (meth)acrylate having polymerizable groups reacting by means other than radicals to the total mass of component (C1) (mass of (meth)acrylate having polymerizable groups reacting by means other than radicals (amount charged) / total mass of component (C1) (amount charged)) may be, for example, 0 to 0.7, 0 to 0.5, or 0 to 0.3 from the viewpoint of improving reliability.

[0061] Component (C1) may contain polyfunctional (bifunctional or more) and monofunctional (meth)acrylates, as well as other radical polymerizable compounds. Examples of other radical polymerizable compounds include maleimide compounds, vinyl ether compounds, allyl compounds, styrene derivatives, acrylamide derivatives, nadiimide derivatives, and the like. The content of the other radical polymerizable compounds may be, for example, 0 to 40% by mass based on the total mass of component (C1).

[0062] • (C2) component: Photoradical polymerization initiator Component (C2) is a photopolymerization initiator that generates radicals upon irradiation with light containing wavelengths in the range of 150 to 750 nm, light containing wavelengths in the range of 254 to 405 nm, or light containing a wavelength of 365 nm (e.g., ultraviolet light).

[0063] Component (C2) decomposes upon exposure to light, generating free radicals. In other words, component (C2) is a compound that generates radicals upon application of external light energy. Component (C2) may be a compound having structures such as an oxime ester structure, bisimidazole structure, acridine structure, α-aminoalkylphenone structure, aminobenzophenone structure, N-phenylglycine structure, acylphosphine oxide structure, benzyldimethylketal structure, or α-hydroxyalkylphenone structure. Component (C2) may also 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, from the viewpoint of easily obtaining a desired melt viscosity and superior connection resistance reduction effect.

[0064] 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)], etanone,1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(o-acetyloxime), and others.

[0065] Specific examples of compounds having an α-aminoalkylphenone structure include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1-morpholinophenyl)-butanone-1.

[0066] Specific examples of compounds having an acylphosphine oxide structure include bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0067] The content of component (C2) 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 component (C1), from the viewpoint of suppressing the flow of conductive particles.

[0068] The content of the cured product of component (C) (the sum of components (C1) and (C2)) 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 first adhesive layer, from the viewpoint of suppressing the flow of conductive particles. The content of the cured product of component (C) may be 50% by mass or less, 40% by mass or less, or 30% by mass or less, based on the total mass of the first adhesive layer, from the viewpoint of reducing connection resistance. When the content of the cured product of component (C) is within the above range, the effects of this disclosure tend to be significantly exhibited. The content of component (C) in the composition or composition layer (based on the total mass of the composition or composition layer) may be the same as the above range.

[0069] (D) Component: Thermosetting resin component The first adhesive layer 1 may further contain component (D). Component (D) is not particularly limited as long as it is a resin component that hardens by heat, but if component (C) is a resin component that has radical curing properties, component (D) may be a resin component that has cationic curing properties from the viewpoint of being superior in terms of connection resistance. Component (D) may include, for example, a cationic polymerizable compound (hereinafter sometimes referred to as "component (D1)") and a thermal cationic polymerization initiator (hereinafter sometimes referred to as "component (D2)"). Component (D) may be a component consisting of component (D1) and component (D2). The first thermosetting resin component, the second thermosetting resin component, and the third thermosetting resin component refer to the thermosetting resin components contained in the first adhesive layer, the second adhesive layer, and the third adhesive layer, respectively. The types and contents of the components (e.g., component (D1), component (D2), etc.) contained in the first thermosetting resin component, the second thermosetting resin component, and the third thermosetting resin component may be the same or different from each other.

[0070] • (D1) Component: Cationic polymerizable compound Component (D1) is a compound that undergoes polymerization or crosslinking with respect to component (D2) by a substance (such as an acid) generated by heating. Note that component (D1) means a compound that does not have radical polymerizable groups that react with radicals, and component (D1) is not included in component (C1). From the viewpoint of further improving the effect of reducing connection resistance and providing superior connection reliability, component (D1) may be at least one selected from the group consisting of, for example, oxetane compounds and alicyclic epoxy compounds. From the viewpoint of easily obtaining the desired melt viscosity, it is preferable that component (D1) contains both oxetane compounds and alicyclic epoxy compounds.

[0071] The oxetane compound used as component (D1) is not particularly limited as long as it has an oxetanyl group and does not have a radical polymerizable group. Examples of commercially available oxetane compounds include 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.).

[0072] The alicyclic epoxy compound used as component (D1) is not particularly limited as long as it has an alicyclic epoxy group (e.g., an epoxycyclohexyl group) and does not have a radical polymerizable group. Examples of commercially available alicyclic epoxy compounds include EHPE3150, EHPE3150CE, Celoxide 8010, Celoxide 2021P, and Celoxide 2081 (trade names, manufactured by Daicel Corporation).

[0073] • (D2) component: Thermal cationic polymerization initiator Component (D2) is a thermal polymerization initiator that generates an acid or the like upon heating to initiate polymerization. Component (D2) may be a salt compound composed of a cation and anion. Component (D2) 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 - Examples include onium salts such as sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, and anilinium salts, which have anions such as those mentioned above.

[0074] (D2) Component is, from the viewpoint of storage stability, for example, an anion containing boron as a constituent element, i.e., BF4 - Or BR4 - (R represents two or more fluorine atoms or phenyl groups substituted with two or more trifluoromethyl groups.) The salt compound may have these elements. An anion containing boron as a constituent element is BR4 - It may be, and more specifically, tetrakis(pentafluorophenyl)borate.

[0075] The onium salt as component (D2) may be an anilinium salt, for example, as it has resistance to substances that can inhibit cationic hardening. Examples of anilinium salt compounds include N,N-dimethylanilinium salt, N,N-diethylanilinium salt, and other N,N-dialkylanilinium salts.

[0076] Component (D2) may be an anilinium salt having an anion containing boron as a constituent element. Examples of commercially available salt compounds of this type include CXC-1821 (trade name, manufactured by King Industries).

[0077] The content of component (D2) may be, for example, 0.1 to 20 parts by mass, 1 to 18 parts by mass, 3 to 15 parts by mass, or 5 to 12 parts by mass per 100 parts by mass of component (D1), from the viewpoint of ensuring the formability and curability of the adhesive film for forming the first adhesive layer.

[0078] The content of component (D) may be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more, based on the total mass of the first adhesive layer, from the viewpoint of ensuring the curability of the adhesive film for forming the first adhesive layer. The content of component (D) may be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the total mass of the first adhesive layer, from the viewpoint of ensuring the formation of the adhesive film for forming the first adhesive layer. When the content of component (D) is within the above ranges, the effects of this disclosure tend to be significantly exhibited. The content of component (D) in the composition or composition layer (based on the total mass of the composition or composition layer) may be the same as the above ranges.

[0079] Other ingredients The first adhesive layer 1 may further contain other components in addition to component (A), component (B), component (C) (cured product of component (C)), and component (D). Examples of other components include coupling agents (hereinafter sometimes referred to as "component (E)") and fillers (hereinafter sometimes referred to as "component (F)").

[0080] Examples of component (E) 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. The adhesion of the first adhesive layer 1 can be further improved by containing component (E). Component (E) may be, for example, a silane coupling agent. The content of component (E) may be 0.1 to 10% by mass based on the total mass of the first adhesive layer. The content of component (E) in the composition or composition layer (based on the total mass of the composition or composition layer) may be the same as the range described above.

[0081] Component (F) may be, for example, a non-conductive filler (e.g., non-conductive particles). Component (F) may be either an inorganic filler or an organic filler. Examples of inorganic fillers include metal oxide nanoparticles such as silica nanoparticles, alumina nanoparticles, silica-alumina nanoparticles, titania nanoparticles, and zirconia nanoparticles; and inorganic nanoparticles such as metal nitride nanoparticles. Examples of organic fillers include organic nanoparticles such as silicone nanoparticles, methacrylate-butadiene-styrene nanoparticles, acrylic-silicone nanoparticles, polyamide nanoparticles, and polyimide nanoparticles. Component (F) may be, for example, silica nanoparticles. The content of component (F) may be 0.1 to 10% by mass based on the total mass of the first adhesive layer. The content of component (F) in the composition or composition layer (based on the total mass of the composition or composition layer) may be the same as the range described above.

[0082] Other additives The first adhesive layer 1 may further contain other additives such as softeners, accelerators, degradation inhibitors, colorants, flame retardants, and thixotropic agents. The content of these other additives may be, for example, 0.1 to 10% by mass based on the total mass of the first adhesive layer. The content of other additives in the composition or composition layer (based on the total mass of the composition or composition layer) may be the same as the range described above.

[0083] The thickness d1 of the first adhesive layer 1 may be 5 μm or less, for example, 4.5 μm or less, 4 μm or less, 3.5 μm or less, 3 μm or less, or 2.5 μm or less. By making the thickness d1 of the first adhesive layer 1 5 μm or less, the fluidity of conductive particles during circuit connection can be further suppressed. The thickness d1 of the first adhesive layer 1 may be, for example, 0.1 μm or more or 0.7 μm or more. Note that, as shown in Figure 1, if a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 1 (for example, protruding toward the second adhesive layer 2), the distance from the surface 2a of the first adhesive layer 1 opposite to the second adhesive layer 2 side to the boundary S between the first adhesive layer 1 and the second adhesive layer 2 located in the spaced portion between adjacent conductive particles 4, 4 (the distance shown as d1 in Figure 1) is the thickness of the first adhesive layer 1, and the exposed portion of the conductive particles 4 is not included in the thickness of the first adhesive layer 1. The length of the exposed portion of the conductive particle 4 may be, for example, 0.1 μm or more, or 5 μm or less.

[0084] The ratio of the thickness of the first adhesive layer 1 to the average particle size of component (A) (conductive particles 4) (thickness of the first adhesive layer 1 / average particle size of component (A) (conductive particles 4)) may be 0.50 or more, for example, 0.55 or more or 0.60 or more. By having a ratio of 0.50 or more, the amount of resin between opposing circuits is reduced, and an increase in the connection resistance between opposing circuits can be suppressed. The ratio may be, for example, 2.00 or less, 1.50 or less, 1.20 or less, 1.00 or less, or 0.80 or less.

[0085] <Second adhesive layer> The second adhesive layer 2 may contain component (D). Since the components (D1) and (D2) used in component (D) in the second adhesive layer 2 (i.e., the second thermosetting resin component) are the same as the components (D1) and (D2) used in component (D) in the first adhesive layer 1 (i.e., the first thermosetting resin component), a detailed explanation is omitted here. The second thermosetting resin component may be the same as or different from the first thermosetting resin component.

[0086] The content of component (D) (the sum of components (D1) and (D2)) may be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more, based on the total mass of the second adhesive layer, from the viewpoint of maintaining reliability. The content of component (D) (the sum of components (D1) and (D2)) may be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the total mass of the second adhesive layer, from the viewpoint of preventing resin leakage defects in reels, which is one form of supply.

[0087] The second adhesive layer 2 may further contain component (B) of the first adhesive layer 1. Here, component (B) may consist only of component (B2) and not component (B1). That is, the second adhesive layer 2 may further contain component (B2) as component (B). The content of component (B) may be 1% by mass or more, 5% by mass or more, or 10% by mass or more, and 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 second adhesive layer.

[0088] The second adhesive layer 2 may further contain other components and other additives of the first adhesive layer 1. Preferred embodiments of the other components and other additives are the same as those of the preferred embodiments of the first adhesive layer 1.

[0089] The content of component (E) may be 0.1 to 10% by mass, based on the total mass of the second adhesive layer.

[0090] The content of component (F) may be 1% by mass or more, 10% by mass or more, or 30% by mass or more, and may be 90% by mass or less, 70% by mass or less, or 50% by mass or less, based on the total mass of the second adhesive layer.

[0091] The content of other additives may be, for example, 0.1 to 10% by mass, based on the total mass of the second adhesive layer.

[0092] The thickness d2 of the second adhesive layer 2 may be set appropriately according to the height of the electrodes of the circuit member to be bonded. The thickness d2 of the second adhesive layer 2 may be 5 μm or more, 7 μm or more, 15 μm or less, or 11 μm or less, from the viewpoint of being able to sufficiently fill the space between electrodes and seal the electrodes and obtain better connection reliability. If a part of the conductive particles 4 is exposed from the surface of the first adhesive layer 1 (for example, protruding toward the second adhesive layer 2 side), the distance from the surface 3a of the second adhesive layer 2 opposite to the first adhesive layer 1 side to the boundary S between the first adhesive layer 1 and the second adhesive layer 2 located in the spaced portion between adjacent conductive particles 4, 4 (the distance shown as d2 in Figure 1) is the thickness of the second adhesive layer 2.

[0093] The thickness of the adhesive film 10 (the sum of the thicknesses of all the layers constituting the adhesive film 10, in Figure 1, the sum of the thickness d1 of the first adhesive layer 1 and the thickness d2 of the second adhesive layer 2) may be, for example, 5 μm or more or 8 μm or more, and 30 μm or less or 20 μm or less.

[0094] In the adhesive film 10, conductive particles 4 are dispersed in the first adhesive layer 1. Therefore, the adhesive film 10 is an anisotropically conductive adhesive film having anisotropic conductivity. The adhesive film 10 is interposed between a first circuit member having a first electrode and a second circuit member having a second electrode, and is used to electrically connect the first electrode and the second electrode to each other by thermocompression bonding the first circuit member and the second circuit member.

[0095] According to the adhesive film 10, by including component (B1) as component (B), it is possible to form an adhesive film for circuit connections that can suppress the localization of conductive particles even when heat and external force are applied.

[0096] Although the adhesive film of this embodiment has been described above, this disclosure is not limited to the above embodiment.

[0097] The adhesive film may consist of two layers, for example, a first adhesive layer and a second adhesive layer, or it may consist of three or more layers, including the first adhesive layer and the second adhesive layer. The adhesive film may further include, for example, a third adhesive layer containing a (third) thermosetting resin component, provided on the side of the first adhesive layer opposite to the second adhesive layer. In the adhesive film, there may be a first region, which is a region formed from the first adhesive film (first adhesive layer), and a third region, which is a region formed from the third adhesive film (third adhesive layer), provided adjacent to the first region. The adhesive film may further include a third region containing a (third) thermosetting resin component, provided adjacent to the side of the first region opposite to the second region.

[0098] The third adhesive layer may contain component (D). Since components (D1) and (D2) used in component (D) in the third adhesive layer (i.e., the third thermosetting resin component) are the same as components (D1) and (D2) used in component (D) in the first adhesive layer 1 (i.e., the first thermosetting resin component), a detailed explanation is omitted here. The third thermosetting resin component may be the same as or different from the first thermosetting resin component. The third thermosetting resin component may be the same as or different from the second thermosetting resin component.

[0099] The content of component (D) (the sum of components (D1) and (D2)) may be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more, based on the total mass of the third adhesive layer, from the viewpoint of providing good transferability and peel resistance. The content of component (D) (the sum of components (D1) and (D2)) may be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the total mass of the third adhesive layer, from the viewpoint of providing good half-cutability and blocking resistance (suppression of resin seepage from the reel).

[0100] The third adhesive layer may further contain component (B) of the first adhesive layer 1. Here, component (B) may consist only of component (B2) and not component (B1). That is, the third adhesive layer may further contain component (B2) as component (B). The content of component (B) may be 10% by mass or more, 20% by mass or more, or 30% by mass or more, and 80% by mass or less, 70% by mass or less, or 60% by mass or less, based on the total mass of the second adhesive layer.

[0101] The third adhesive layer may further contain other components and other additives of the first adhesive layer 1. Preferred embodiments of the other components and other additives are the same as those of the preferred embodiment of the first adhesive layer 1.

[0102] The content of component (E) may be 0.1 to 10% by mass, based on the total mass of the third adhesive layer.

[0103] The content of component (F) may be 1% by mass or more, 5% by mass or more, or 10% by mass or more, and may be 50% by mass or less, 40% by mass or less, or 30% by mass or less, based on the total mass of the third adhesive layer.

[0104] The content of other additives may be, for example, 0.1 to 10% by mass, based on the total mass of the third adhesive layer.

[0105] The thickness of the third adhesive layer may be set appropriately according to the height of the electrodes of the circuit components to be bonded. The thickness of the third adhesive layer may be 0.2 μm or more and 3 μm or less, from the viewpoint of sufficiently filling the space between electrodes and sealing the electrodes, thereby obtaining better connection reliability.

[0106] Furthermore, although the circuit connection adhesive film in the above embodiment is an anisotropically conductive adhesive film having anisotropic conductivity, the circuit connection adhesive film may also be a conductive adhesive film that does not have anisotropic conductivity.

[0107] [Method for manufacturing adhesive film for circuit connections] A method for manufacturing an adhesive film for circuit connections according to one embodiment may include, for example, a step of irradiating a composition layer comprising a composition containing component (A), component (B1) (a resin in which at least a portion of the hydroxyl groups in the phenoxy resin is modified with a group represented by formula (1) (resin (1))), component (B), component (C), and component (D) (a first thermosetting resin component) with light to form a first adhesive layer (first step), and a step of laminating a second adhesive layer containing component (D) (a second thermosetting resin component) on the first adhesive layer (second step). The manufacturing method may further include a step of laminating a third adhesive layer containing component (D) (a third thermosetting resin component) on the layer of the first adhesive layer opposite to the second adhesive layer (third step).

[0108] In the first step, for example, a composition containing component (A), component (B1) (resin (1)), component (B), component (C), and component (D), as well as other components and other additives added as needed, is dissolved or dispersed in an organic solvent by stirring, mixing, kneading, etc., to prepare a varnish composition. Then, the varnish composition is applied to a mold-release treated substrate using a knife coater, roll coater, applicator, comma coater, die coater, etc., and the organic solvent is evaporated by heating to form a composition layer on the substrate. At this time, the thickness of the final obtained first adhesive layer (first adhesive film) can be adjusted by adjusting the amount of varnish composition applied. Subsequently, the composition layer is irradiated with light to cure component (C) in the composition layer and form a first adhesive layer on the substrate. At this time, some or all of the groups represented by formula (1) in resin (1) as component (B1) can be converted to groups represented by formula (1A). The first adhesive layer can be called the first adhesive film.

[0109] The organic solvent used in the preparation of the varnish composition is not particularly limited as long as it has the property of uniformly dissolving or dispersing each component. Examples of such organic solvents include toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, and butyl acetate. These organic solvents can be used individually or in combination of two or more. Stirring, mixing, or kneading during the preparation of the varnish composition can be carried out using, for example, a stirrer, a 3-roll mill, a ball mill, a bead mill, a homodisper, etc.

[0110] The substrate is not particularly limited as long as it has heat resistance that can withstand the heating conditions when volatilizing organic solvents. Examples of such substrates include stretched 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, liquid crystal polymers, etc. (for example, films).

[0111] The heating conditions for volatilizing the organic solvent from the varnish composition applied to the substrate can be appropriately set according to the organic solvent used. For example, the heating conditions may be 40 to 120°C for 0.1 to 10 minutes.

[0112] For light irradiation during the curing process, it is preferable to use irradiation light (e.g., ultraviolet light) that includes wavelengths in the range of 150 to 750 nm. Light irradiation can be performed using, for example, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, LED light sources, etc. The integrated light intensity of the light irradiation can be set as appropriate, for example, 500 to 3000 mJ / cm². 2 That's fine.

[0113] The second step is to laminate a second adhesive layer onto the first adhesive layer. In the second step, for example, first, a second adhesive layer is formed on the substrate in the same manner as in the first step, except that component (D) and other components and additives added as needed are used, and light irradiation is not performed, thereby obtaining a second adhesive film. Then, the second adhesive layer can be laminated onto the first adhesive layer by bonding the first adhesive film and the second adhesive film together. Alternatively, in the second step, for example, the second adhesive layer can also be laminated onto the first adhesive layer by applying a varnish composition obtained using component (D) and other components and additives added as needed onto the first adhesive layer and volatilizing the organic solvent.

[0114] Methods for bonding the first adhesive film and the second adhesive film include, for example, heat pressing, roll lamination, and vacuum lamination. Lamination can be carried out, for example, under temperature conditions of 0 to 80°C.

[0115] The third step is to laminate the third adhesive layer onto the layer of the first adhesive layer opposite to the second adhesive layer. In the third step, for example, first, the third adhesive layer is formed on the substrate in the same manner as in the second step to obtain the third adhesive film. Then, the third adhesive layer can be laminated onto the layer of the first adhesive layer opposite to the second adhesive layer by laminating the third adhesive film to the side of the first adhesive film opposite to the second adhesive film. Alternatively, in the third step, for example, the third adhesive layer can also be laminated onto the first adhesive layer by applying a varnish composition to the layer of the first adhesive layer opposite to the second adhesive layer in the same manner as in the second step and volatilizing the organic solvent. The lamination method and conditions are the same as in the second step.

[0116] [Circuit connection structure and method for manufacturing the same] The following describes a circuit connection structure using an adhesive film 10 as a circuit connection material and a method for manufacturing the same.

[0117] Figure 2 is a schematic cross-sectional view showing one embodiment of a circuit connection structure. As shown in Figure 2, the circuit connection structure 20 includes a first circuit board 11 and a first circuit member 13 having a first electrode 12 formed on the main surface 11a of the first circuit board 11, a second circuit board 14 and a second circuit member 16 having a second electrode 15 formed on the main surface 14a of the second circuit board 14, and a circuit connection portion 17 disposed between the first circuit member 13 and the second circuit member 16, which electrically connects the first electrode 12 and the second electrode 15 to each other.

[0118] The first circuit member 13 and the second circuit member 16 may be the same or different from each other. The first circuit member 13 and the second circuit member 16 may be a glass substrate or plastic substrate on which electrodes are formed; a printed circuit board; a ceramic circuit board; a flexible circuit board; an IC chip, etc. The first circuit board 11 and the second circuit board 14 may be formed from an inorganic material such as a semiconductor, glass, or ceramic; an organic material such as polyimide or polycarbonate; or a composite material such as glass / epoxy.

[0119] The first electrode 12 and the second electrode 15 may be electrodes containing metals such as gold, silver, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, aluminum, molybdenum, and titanium, or oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), and indium gallium zinc oxide (IGZO). The first electrode 12 and the second electrode 15 may also be electrodes formed by laminating two or more of these metals, oxides, etc. The electrodes formed by laminating two or more types may have two or more layers, or three or more layers. If the first circuit member 13 is a plastic substrate, the first electrode 12 may be an electrode having a titanium layer on its outermost surface. The first electrode 12 and the second electrode 15 may be circuit electrodes or bump electrodes. At least one of the first electrode 12 and the second electrode 15 may be a bump electrode. Figure 2 shows an embodiment in which the first electrode 12 is a circuit electrode and the second electrode 15 is a bump electrode.

[0120] The circuit connection portion 17 includes a cured product of the adhesive film 10. The circuit connection portion 17 may consist of a cured product of the adhesive film 10. The circuit connection portion 17 includes, for example, a first cured product region 18 located on the first circuit member 13 side in the direction in which the first circuit member 13 and the second circuit member 16 face each other (hereinafter referred to as the "opposing direction"), which consists of cured products of components (B), (C), (D), etc., other than the conductive particles 4 in the first adhesive layer; a second cured product region 19 located on the second circuit member 16 side in the opposing direction, which consists of cured products of component (D), etc., in the second adhesive layer; and conductive particles 4 interposed at least between the first electrode 12 and the second electrode 15 to electrically connect the first electrode 12 and the second electrode 15 to each other. As shown in Figure 2, the circuit connection portion 17 does not necessarily have two distinct regions between the first cured material region 18 and the second cured material region 19, and the cured material derived from the first adhesive layer and the cured material derived from the second adhesive layer may be mixed together to form a single cured material region.

[0121] Figure 3 is a schematic cross-sectional view showing one embodiment of a method for manufacturing a circuit connection structure. Figures 3(a) and 3(b) are schematic cross-sectional views showing each step. As shown in Figure 3, the method for manufacturing the circuit connection structure 20 includes the step of interposing an adhesive film 10 between a first circuit member 13 having a first electrode 12 and a second circuit member 16 having a second electrode 15, and then heat-pressing the first circuit member 13 and the second circuit member 16 together to electrically connect the first electrode 12 and the second electrode 15 to each other.

[0122] Specifically, as shown in Figure 3(a), first, a first circuit member 13 comprising a first circuit board 11 and a first electrode 12 formed on the main surface 11a of the first circuit board 11, and a second circuit member 16 comprising a second circuit board 14 and a second electrode 15 formed on the main surface 14a of the second circuit board 14 are prepared.

[0123] Next, the first circuit member 13 and the second circuit member 16 are arranged so that the first electrode 12 and the second electrode 15 face each other, and the adhesive film 10 is placed between the first circuit member 13 and the second circuit member 16. For example, as shown in Figure 3(a), the adhesive film 10 is laminated onto the first circuit member 13 so that the side with the first adhesive layer 1 faces the main surface 11a of the first circuit board 11. Next, the second circuit member 16 is placed on the first circuit member 13, to which the adhesive film 10 has been laminated, so that the first electrode 12 on the first circuit board 11 and the second electrode 15 on the second circuit board 14 face each other.

[0124] Then, as shown in Figure 3(b), the first circuit member 13, the adhesive film 10, and the second circuit member 16 are heated, and the first circuit member 13 and the second circuit member 16 are pressed together in the thickness direction, thereby thermocompressing them together. At this time, as indicated by the arrows in Figure 3(b), the second adhesive layer 2 has a flowable, uncured thermosetting component, so it flows to fill the gaps between the second electrodes 15 and hardens due to the heating. As a result, the first electrode 12 and the second electrode 15 are electrically connected to each other via the conductive particles 4, and the first circuit member 13 and the second circuit member 16 are bonded to each other, thereby obtaining the circuit connection structure 20 shown in Figure 2. In the manufacturing method of the circuit connection structure 20 of this embodiment, a portion of the first adhesive layer 1 is hardened by light irradiation, so the conductive particles 4 are fixed in the first adhesive layer 1. Furthermore, the first adhesive layer 1 hardly flows during the heat-compression bonding process, and the conductive particles are efficiently captured between the opposing electrodes, thereby reducing the connection resistance between the opposing first electrode 12 and second electrode 15. In addition, by having a thickness of 5 μm or less for the first adhesive layer, the fluidity of the conductive particles during circuit connection can be further suppressed.

[0125] The heating temperature for heat-compression bonding can be set as appropriate, but for example, it may be between 50 and 190°C. The pressurization is not particularly limited as long as it does not damage the adherend, but in the case of COP mounting, for example, the area-equivalent pressure at the bump electrode may be between 0.1 and 50 MPa. In the case of COG mounting, for example, the area-equivalent pressure at the bump electrode may be between 10 and 100 MPa. The heating and pressurization times may be in the range of 0.5 to 120 seconds. [Examples]

[0126] The present disclosure will be described in more detail below with reference to examples. However, the present disclosure is not limited to these examples.

[0127] [Synthesis of resins] (Manufacturing Example 1-1) Synthesis of resin B1-1a In a flask equipped with a stirrer, condenser, thermometer, and gas inlet tube, 400.00 g of methyl ethyl ketone and 200.00 g of toluene, along with 396.16 g of phenoxy resin (FX-293, manufactured by Nippon Steel Chemical & Material Co., Ltd.), were added and stirred until uniformly dissolved. The mixture was then heated to 60°C, and MOI-EG(2-(2-methacryloyloxyethyloxy)ethyl isocyanate, R 1 3.80 g of the compound represented by formula (2), in which x is a methyl group, x is 2, and y is 2 (manufactured by Showa Denko Corporation), and 0.04 g of the catalyst dioctyl tin dilaurate were added, and the flask was stirred while blowing in nitrogen, and the reaction was carried out for 2 hours to obtain the target resin B1-1a. As described above, regarding resin B1-1a... 1 By measuring 1H-NMR and calculating the degradation rate from the integral value of the peaks in the resulting spectrum, the degradation rate of resin B1-1a was found to be 1%.

[0128] (Manufacturing Example 1-2) Synthesis of resin B1-1b Resin B1-1b was obtained in the same manner as in Example 1-1, except that the amount of phenoxy resin added was changed to 388.91 g and the amount of MOI-EG added to 11.05 g. The modification rate of resin B1-1b was 5%.

[0129] (Manufacturing Example 1-3) Synthesis of Resin B1-1c Resin B1-1c was obtained in the same manner as in Example 1-1, except that the amount of phenoxy resin added was changed to 380.50 g and the amount of MOI-EG added to 19.46 g. The modification rate of resin B1-1c was 9%.

[0130] (Manufacturing Example 1-4) Synthesis of resin B1-1d Resin B1-1d was obtained in the same manner as in Example 1-1, except that the amount of phenoxy resin added was changed to 368.43 g and the amount of MOI-EG added to 31.53 g. The modification rate of resin B1-1d was 15%.

[0131] (Manufacturing Example 2-1) Synthesis of resin B1-2a In a flask equipped with a stirrer, condenser, thermometer, and gas inlet tube, 400.00 g of methyl ethyl ketone and 200.00 g of toluene, along with 396.16 g of phenoxy resin (YP-70, manufactured by Nippon Steel Chemical & Material Co., Ltd.), were added and stirred until uniformly dissolved. Then, the temperature was 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 dioctyl tin dilaurate, a catalyst, were added. The flask was stirred while blowing in nitrogen, and the reaction was carried out for 2 hours to obtain the target resin B1-2a. As described above, regarding resin B1-2a... 1 By measuring 1H-NMR and calculating the degradation rate from the integral value of the peaks in the resulting spectrum, the degradation rate of resin B1-2a was found to be 1%.

[0132] (Manufacturing Example 2-2) Synthesis of resin B1-2b Resin B1-2b was obtained in the same manner as in Example 2-1, except that the amount of phenoxy resin added was changed to 381.66 g and the amount of MOI-EG added to 18.30 g. The modification rate of resin B1-2b was 5%.

[0133] (Manufacturing Example 2-3) Synthesis of Resin B1-2c Resin B1-2c was obtained in the same manner as in Example 2-1, except that the amount of phenoxy resin added was changed to 368.19 g and the amount of MOI-EG added to 31.77 g. The modification rate of resin B1-2c was 9%.

[0134] (Manufacturing Example 3-1) Synthesis of resin B1-3a In a flask equipped with a stirrer, condenser, thermometer, and gas inlet tube, 400.00 g of methyl ethyl ketone and 200.00 g of toluene, along with 388.91 g of phenoxy resin (FX-293, manufactured by Nippon Steel Chemical & Material Co., Ltd.), were added and stirred until uniformly dissolved. The mixture was then heated to 60°C, and AOI (2-(2-acryloyloxyethyloxy)ethyl isocyanate, R 1 11.05 g of the compound represented by formula (2), where x is hydrogen, x is 2, and y is 1 (manufactured by Showa Denko Corporation), and 0.04 g of the catalyst dioctyl tin dilaurate were added, and the flask was stirred while blowing in nitrogen, and the reaction was carried out for 2 hours to obtain the target resin B1-3a. As described above, regarding resin B1-3a... 1 By measuring 1H-NMR and calculating the degradation rate from the integral value of the peaks in the resulting spectrum, the degradation rate of resin B1-3a was found to be 5%.

[0135] [Preparation of the first adhesive layer, the second adhesive layer, and the third adhesive layer] The following materials were used in the preparation of the first adhesive layer, the second adhesive layer, and the third adhesive layer.

[0136] (A) Component: Conductive particles A-1: Conductive particles with an average particle size of 3.2 μm are used, in which the surface of a plastic core is plated with Ni, and the outermost surface is replaced with Pd plating.

[0137] (B) Component: Thermoplastic resin • (B1) component: A resin in which at least some of the hydroxyl groups in the phenoxy resin are modified with a group represented by formula (1). B1-1a: Resin from manufacturing example 1-1 (modification rate: 1%) B1-1b: Resin from manufacturing example 1-2 (modification rate: 5%) B1-1c: Resin from manufacturing example 1-3 (modification rate: 9%) B1-1d: Resin from manufacturing example 1-4 (modification rate: 15%) B1-2a: Resin from manufacturing example 2-1 (modification rate: 1%) B1-2b: Resin from manufacturing example 2-2 (modification rate: 5%) B1-2c: Resin from manufacturing example 2-3 (modification rate: 9%) B1-3a: Resin from manufacturing example 3-1 (modification rate: 5%) • (B2) component: Thermoplastic resin other than (B1) component B2-1: FX-293 (Phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) B2-2: YP-70 (Phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) B2-3: FX-310 (Phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) B2-4: TOPR-300 (Phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.) B2-5: ZX1356-2 (Phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.)

[0138] (C) Component: Photocurable resin component • (C1) component: radical polymerizable compound C1-1: A-BPEF (Ethoxylated fluorene-type di(meth)acrylate (bifunctional), manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) C1-2: VR-90 (Bisphenol A type epoxy (meth)acrylate (bifunctional) (vinyl ester resin), manufactured by Showa Denko Corporation) • (C2) component: Photoradical polymerization initiator C2-1: IrgacureOXE-02 (a compound with an oxime ester structure, manufactured by BASF)

[0139] (D) Component: Thermosetting resin component • (D1) Component: Cationic polymerizable compound D1-1: OXBP (Oxetane compound, manufactured by Ube Industries, Ltd.) D1-2: OXSQ (Oxetane compound, manufactured by Toagosei Co., Ltd.) D1-3: EHPE3150 (Alicyclic epoxy compound, manufactured by Daicel Corporation) D1-4: CEL2021P (Alicyclic epoxy compound, manufactured by Daicel Corporation) • (D2) component: Thermal cationic polymerization initiator D2-1: CXC-1821 (Anilinium salt, manufactured by King Industries)

[0140] (E) Component: Coupling agent E-1: SH-6040 (3-Glycidoxypropyltrimethoxysilane, manufactured by Toray Dow Corning Co., Ltd.)

[0141] (F) Component: Filler F-1: R805 (Silica microparticles, manufactured by Evonik Industries AG) F-2: SE2050 (Silica microparticles, manufactured by Admatex Co., Ltd.)

[0142] <Preparation of the first adhesive film (first adhesive layer)> The materials shown in Tables 1 and 2 were mixed in the composition ratios shown in Tables 1 and 2 (the values ​​in Tables 1 and 2 represent the non-volatile content) to obtain adhesive varnishes diluted with organic solvents. These were then coated onto a release-treated PET (polyethylene terephthalate) film under a magnetic field, and the organic solvents were dried with hot air at 70°C for 5 minutes to obtain composition layers containing each component. The thickness of composition layers 1a to 1o after drying was 2 μm, and the thickness of composition layers 1p and 1q after drying was 6 μm. Next, composition layers 1a to 1q were irradiated with light (UV irradiation: metal halide lamp, cumulative light intensity: 1900-2300 mJ / cm²). 2 First adhesive films (first adhesive layers) 1A to 1Q were obtained by ). The first adhesive films 1A to 1Q contain a cured product of a photocurable resin component and a thermosetting resin component. The thickness of the first adhesive films (first adhesive layers) 1A to 1O was 2 μm, and the thickness of the first adhesive films (first adhesive layers) 1P and 1Q was 6 μm.

[0143] [Table 1]

[0144] [Table 2]

[0145] <Preparation of the second adhesive film (second adhesive layer)> The materials shown in Table 3 were mixed in the composition ratios shown in Table 3 (the values ​​in Table 3 represent the non-volatile content) to obtain an adhesive varnish diluted with an organic solvent. This was then coated onto a release-treated PET (polyethylene terephthalate) film. The second adhesive film 2A was coated to a dry thickness of 9 μm. The second adhesive film 2B was coated to a dry thickness of 10 μm. The second adhesive film 2C was coated to a dry thickness of 6 μm. Next, the organic solvent was dried to obtain second adhesive films 2A to 2C containing each component. The constituent components of the second adhesive films 2A to 2C are identical.

[0146] [Table 3]

[0147] <Third adhesive film (third adhesive layer)> The materials shown in Table 4 were mixed in the composition ratios shown in Table 4 (the values ​​in Table 4 represent the non-volatile content) to obtain an adhesive varnish diluted with an organic solvent. This was then coated onto a release-treated PET (polyethylene terephthalate) film, and the organic solvent was dried to obtain a third adhesive film 3A. The third adhesive film 3A was coated to a thickness of 1 μm after drying.

[0148] [Table 4]

[0149] (Examples 1-9 and Comparative Examples 1-8) [Fabrication of adhesive film] Using the first adhesive film, the second adhesive film, and the third adhesive film prepared as described above, adhesive films with the configurations shown in Tables 5 and 6 were prepared. For example, in the adhesive film of Example 1, the first adhesive film 1A was bonded to the second adhesive film 2A while applying a temperature of 50-60°C, and the release film of the first adhesive film 1A was peeled off. Next, the third adhesive film 3A was bonded to the first adhesive film 1A, which was exposed by peeling off the release film, while applying a temperature of 50-60°C, to obtain the adhesive film of Example 1. For the three-layer adhesive films of Examples 2-5, 8, 9 and Comparative Examples 1-4, 7, 8, adhesive films with the configurations shown in Tables 5 and 6 were prepared in the same manner as in Example 1. For the two-layer adhesive films of Examples 6, 7 and Comparative Examples 5, 6, adhesive films with the configurations shown in Tables 5 and 6 were prepared in the same manner as in Example 1, except that the third adhesive film was not bonded.

[0150] [Measurement of conductive particle density] The adhesive films of Examples 1-9 and Comparative Examples 1-8 were examined using a microscope and image analysis software (product name: ImagePro, manufactured by Hakuto Co., Ltd.) at a depth of 25,000 μm. 2 The number of conductive particles per 1 mm was measured at 20 locations, and the average value was calculated. 2 The conductive particle density was calculated by converting it to the number of conductive particles per unit area. The results are shown in Tables 5 and 6.

[0151] [Evaluation of localization of conductive particles] The adhesive films of Examples 1-9 and Comparative Examples 1-8 were cut to a predetermined size (13 mm long x 13 mm wide x approximately 12 μm thick) to prepare evaluation films. Next, the evaluation films were attached to a polyimide substrate with aluminum wiring (substrate thickness: 50 μm, aluminum 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 9 μm, number of bumps: 184) was mounted using a flip-chip mounting device (product name: FCB3-3, manufactured by Panasonic Corporation). The mounting conditions were a crimping head temperature of 190°C, a crimping time of 10 seconds, and a crimping pressure of 30 MPa. In this way, a semiconductor device was fabricated in which the polyimide substrate with aluminum wiring and the semiconductor chip with gold bumps were daisy-chained. For the fabricated semiconductor device, a shear force measuring device was used to peel the semiconductor chip from the substrate, and the degree of localization of conductive particles 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 conductive particles are absent is less than 1% of the total area. Grade B: The area of ​​the semiconductor chip where conductive particles are absent is 1% or more but less than 15% of the total area. Grade C: The area of ​​the semiconductor chip is 15% or more of the area where conductive particles are absent.

[0152] [Evaluation of connection resistance] (Preparation of circuit components) As the first circuit component, a polyimide substrate (outer dimensions: 38 mm × 28 mm, thickness: 50 μm) was prepared with a Ti (50 nm) / Al (400 nm) wiring pattern (pattern width: 19 μm, inter-electrode spacing: 5 μm) formed on its surface. As the second circuit component, an IC chip (outer dimensions: 0.9 mm × 20.3 mm, thickness: 0.3 mm, bump electrode size: 70 μm × 12 μm, inter-bump electrode spacing: 12 μm, bump electrode thickness: 9 μm) was prepared with gold bump electrodes arranged in a staggered pattern in two rows.

[0153] (Fabrication of circuit connection structures) In the evaluation of conductive particle localization, circuit connection structures were fabricated using the adhesive films of Examples 1-9 and Comparative Examples 7 and 8, which received an A or B rating. The adhesive film was placed on the first circuit member so that the first or third adhesive layer of the adhesive film was in contact with the first circuit member. A thermocompression bonding apparatus (BS-17U, manufactured by Ohashi Seisakusho Co., Ltd.) consisting of a ceramic heater stage and a tool (8 mm x 50 mm) was used, at 70°C and 0.98 MPa (10 kgf / cm²). 2 The adhesive film was attached to the first circuit member by heating and pressurizing for 2 seconds under the conditions specified above, and the release film on the side of the adhesive film opposite to the first circuit member was peeled off. Next, the bump electrode of the first circuit member and the circuit electrode of the second circuit member were aligned, and then the second adhesive layer of the adhesive film was attached to the second circuit member by heating and pressurizing for 5 seconds under the conditions specified above the measured maximum temperature of the adhesive film (160°C) and the area-converted pressure at the bump electrode (20 MPa), thereby fabricating a circuit connection structure.

[0154] (Evaluation of connection resistance) The connection resistance was evaluated using the obtained circuit connection structure. The connection resistance was evaluated using the four-terminal measurement method, and the average value of the connection resistance values ​​measured at 14 locations was used for evaluation. A digital multimeter (7461A, manufactured by ADC Corporation) was used for measurement. A connection resistance value of less than 1.0Ω was evaluated as A, a connection resistance value of 1.0Ω or more and less than 2.0Ω was evaluated as B, and a connection resistance value of 2.0Ω or more was evaluated as C. The results are shown in Tables 5 and 6.

[0155] [Table 5]

[0156] [Table 6]

[0157] As shown in Tables 4 and 5, the adhesive films of Examples 1 to 9 performed well in both the evaluation of conductive particle localization and the evaluation of connection resistance. Therefore, it was confirmed that the adhesive film of this disclosure can suppress the localization of conductive particles and reduce connection resistance even when heat and external force are applied. [Explanation of Symbols]

[0158] 1...First adhesive layer, 2...Second adhesive layer, 4...Conductive particles, 5...Adhesive components, 10...Adhesive film for circuit connection (adhesive film), 11...First circuit board, 12...First electrode (circuit electrode), 13...First circuit member, 14...Second circuit board, 15...Second electrode (bump electrode), 16...Second circuit member, 17...Circuit connection part, 20...Circuit connection structure.

Claims

1. A first adhesive layer containing conductive particles and a thermoplastic resin, A second adhesive layer provided on the first adhesive layer, Equipped with, The first adhesive layer further contains a cured product of a photocurable resin component and a first thermosetting resin component, The second adhesive layer further contains a second thermosetting resin component, The thermoplastic resin includes a resin in which at least a portion of the hydroxyl groups in the phenoxy resin are modified with a group represented by the following formula (1) or the following formula (1A). Adhesive film for circuit connections. 【Chemistry 1】 [In formula (1), R １ x represents a hydrogen atom or a methyl group, x represents an integer from 2 to 6, and y represents an integer from 1 to 6. * indicates the bonding position with the oxygen atom derived from the hydroxyl group. 【Chemistry 2】 [In formula (1A), R １ x, y, and * are the same as above. *1 and *2 indicate bonding positions with carbon atoms of other radical polymerizable groups.

2. The thickness of the first adhesive layer is 5 μm or less. The ratio of the thickness of the first adhesive layer to the average particle size of the conductive particles is 0.50 or more. The adhesive film for circuit connection according to claim 1.

3. The photocurable resin component comprises a radical polymerizable compound and a photoradical polymerization initiator. The adhesive film for circuit connection according to claim 1.

4. The first thermosetting resin component and the second thermosetting resin component include a cationic polymerizable compound and a thermal cationic polymerization initiator. The adhesive film for circuit connection according to claim 1.

5. The cationic polymerizable compound is at least one selected from the group consisting of oxetane compounds and alicyclic epoxy compounds. The adhesive film for circuit connection according to claim 4.

6. The thermal cationic polymerization initiator is a salt compound having an anion containing boron as a constituent element. The adhesive film for circuit connection according to claim 4.

7. The present invention further comprises a third adhesive layer containing a third thermosetting resin component, provided on the side of the first adhesive layer opposite to the second adhesive layer. The adhesive film for circuit connection according to claim 1.

8. The third thermosetting resin component comprises a cationic polymerizable compound and a thermal cationic polymerization initiator. The adhesive film for circuit connection according to claim 7.

9. The method comprises the steps of interposing a circuit connection adhesive film according to any one of claims 1 to 8 between a first circuit member having a first electrode and a second circuit member having a second electrode, and then heat-pressing the first circuit member and the second circuit member together to electrically connect the first electrode and the second electrode to each other. A method for manufacturing a circuit connection structure.

10. A first circuit member having a first electrode, A second circuit member having a second electrode, A circuit connection portion is disposed between the first circuit member and the second circuit member and electrically connects the first electrode and the second electrode to each other, Equipped with, The circuit connection portion includes a cured product of the circuit connection adhesive film described in any one of claims 1 to 8. Circuit connection structure.

Images