JP2022158554A - Adhesive film for circuit connection, and circuit connection structure and method for producing the same - Google Patents

Abstract

To provide an adhesive film for circuit connection that has excellent adhesion to a plastic substrate before curing and also has excellent adhesion to the plastic substrate after curing.SOLUTION: An adhesive film for circuit connection is provided. The adhesive film for circuit connection 10 includes a first region 1 containing a conductive particle 4, a rubber elastic particle 5, and a first adhesive component, and a second region 2 provided adjacent to the first region 1 and containing a second adhesive component.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present disclosure relates to a circuit-connecting adhesive film, a circuit-connecting structure, and a manufacturing method thereof.

2. Description of the Related Art Conventionally, liquid crystal display panels, organic EL panels, and the like have been used as various display means for televisions, PC monitors, mobile phones, smart phones, and the like. In such a display device, so-called COG (chip on glass) mounting, in which a driving IC is directly mounted on the glass substrate of the display panel, is adopted from the viewpoint of fine pitch, light weight and thinness.

In a liquid crystal display panel adopting the COG mounting method, for example, a semiconductor element such as a liquid crystal driving IC is connected on a transparent substrate (such as a glass substrate) having multiple transparent electrodes (such as ITO (indium tin oxide)). be done. 2. Description of the Related Art As an adhesive material for connecting electrode terminals and transparent electrodes of a semiconductor element, an adhesive film for circuit connection, in which conductive particles are dispersed in an adhesive, is used. For example, when a liquid crystal driving IC is mounted as a semiconductor element, the liquid crystal driving IC has a plurality of electrode terminals corresponding to transparent electrodes on its mounting surface, and the liquid crystal driving IC is mounted through an adhesive film for circuit connection. The electrode terminal and the transparent electrode are connected to each other by thermocompression bonding the IC to the transparent substrate to obtain a circuit connection structure.

In recent years, displays having curved surfaces (flexible displays) have been proposed. In such a flexible display, a flexible plastic substrate (such as a polyimide substrate) is used instead of a glass substrate as the substrate, so various electronic components such as a driving IC are also mounted on the plastic substrate. As such a mounting method, COP (chip on plastic) mounting using an adhesive film for circuit connection is being studied (see, for example, Patent Document 1).

JP 2016-054288 A

An adhesive film for circuit connection used for COP mounting is required to have high adhesion to a plastic substrate (especially a polyimide substrate). However, when the circuit connection adhesive film used for COG mounting is applied to COP mounting, the adhesive strength with the plastic substrate is not sufficient, and peeling may occur, for example, after a reliability test under high temperature and high humidity conditions. .

Accordingly, the main object of the present disclosure is to provide an adhesive film for circuit connection that has excellent adhesive strength to a plastic substrate before curing and excellent adhesive strength to a plastic substrate after curing.

One aspect of the present disclosure relates to circuit connecting adhesive films. The circuit-connecting adhesive film includes a first region containing conductive particles, rubber-elastic particles, and a first adhesive component, and a second adhesive component provided adjacent to the first region. and a second region containing According to such a circuit-connecting adhesive film, it is possible to have excellent adhesion to a plastic substrate before curing, and to have excellent adhesion to a plastic substrate after curing. Although the reason why such an effect is exhibited is not necessarily clear, the inclusion of the rubber elastic particles in the first region of the circuit-connecting adhesive film increases the fracture toughness of the composition constituting the circuit-connecting adhesive film. It is presumed that this is because the strength of adhesion to the plastic substrate and the shear strength (adhesive strength to the plastic substrate) are thereby improved.

The first region of the adhesive film for circuit connection may include a conductive particle-containing region containing conductive particles and a rubber elastic particle-containing region containing rubber elastic particles in this order from the second region side. In this case, the rubber elastic particle-containing region may contain a polyfunctional alicyclic epoxy compound. Also, the rubber elastic particle-containing region may further contain a polyfunctional oxetane compound in addition to the polyfunctional alicyclic epoxy compound.

Another aspect of the present disclosure relates to a method of manufacturing a circuit connection structure. The method for manufacturing the circuit connection structure includes interposing the circuit connection adhesive film between a first circuit member having a first electrode and a second circuit member having a second electrode. and thermocompressing the first circuit member and the second circuit member to electrically connect the first electrode and the second electrode to each other.

Another aspect of the present disclosure relates to circuit connection structures. The circuit connection structure is arranged between a first circuit member having a first electrode, a second circuit member having a second electrode, and the first circuit member and the second circuit member, and a circuit connection portion electrically connecting the first electrode and the second electrode to each other. The circuit-connecting part contains a cured product of the circuit-connecting adhesive film.

According to the present disclosure, there is provided an adhesive film for circuit connection that has excellent adhesive strength to a plastic substrate before curing and excellent adhesive strength to a plastic substrate after curing. Some forms of circuit-connecting adhesive films are also excellent in terms of crack resistance of the circuit-connecting structure. Further, according to the present disclosure, a circuit connection structure using such an adhesive film for circuit connection and a method for manufacturing the same are provided.

FIG. 1 is a schematic cross-sectional view showing one embodiment of an adhesive film for circuit connection. FIG. 2 is a schematic cross-sectional view showing one embodiment of the circuit connection structure. FIG. 3 is a schematic cross-sectional view showing an embodiment of a method for manufacturing a circuit connection structure. 3A and 3B are schematic cross-sectional views showing each step.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. However, the present disclosure is not limited to the following embodiments.

In this specification, a numerical range indicated using "to" indicates a range including the numerical values before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or lower limit value of the numerical range at one step may be replaced with the upper limit value or lower limit value of the numerical range at another step. Moreover, in the numerical ranges described in this specification, the upper and lower limits of the numerical ranges may be replaced with the values shown in the examples. Moreover, the upper limit value and the lower limit value described individually can be combined arbitrarily. Moreover, in this specification, "(meth)acrylate" means at least one of acrylate and methacrylate corresponding thereto. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylic acid". Also, "(poly)" means both with and without the "poly" prefix. Moreover, "A or B" may include either one of A and B, or may include both. Materials exemplified below may be used singly or in combination of two or more unless otherwise specified. The content of each component in the composition means the total amount of the plurality of substances present in the composition unless otherwise specified when there are multiple substances corresponding to each component in the composition.

[Adhesive film for circuit connection]
FIG. 1 is a schematic cross-sectional view showing one embodiment of an adhesive film for circuit connection. The circuit-connecting adhesive film 10 shown in FIG. 1 (hereinafter sometimes simply referred to as "adhesive film 10") is a first adhesive containing conductive particles 4, rubber-elastic particles 5, and a first adhesive component. It comprises a single region 1 and a second region 2 adjacent to the first region 1 and containing a second adhesive component. The first region 1 of the adhesive film 10 comprises a conductive particle-containing region 1A containing conductive particles 4 (and the first A adhesive component) and a rubber elastic region containing rubber elastic particles 5 (and the first B adhesive component). and the particle-containing region 1B in this order from the second region 2 side. The conductive particle-containing region 1A has a higher conductive particle content than other regions (regions other than the conductive particle-containing region 1A, the rubber elastic particle-containing region 1B and the second region 2 in the adhesive film 10 shown in FIG. 1). can be a region with a high content of The rubber-elastic-particle-containing region 1B has a higher rubber content than other regions (regions other than the rubber-elastic-particle-containing region 1B, the conductive-particle-containing region 1A and the second region 2 in the adhesive film 10 shown in FIG. 1). It can be a region with a high content of elastic particles.

The first region 1 can be a region formed from a first adhesive film (first adhesive layer). When the first region 1 includes the conductive particle-containing region 1A and the rubber-elastic particle-containing region 1B, the conductive particle-containing region 1A is a region formed from a conductive particle-containing film (conductive particle-containing layer) and has rubber elasticity. The particle-containing region 1B can be a region formed from a rubber-elastic particle-containing film (rubber-elastic particle-containing layer). The second region 2 can be a region formed from a second adhesive film (second adhesive layer).

The adhesive film 10 comprising the rubber elastic particle-containing region 1B, the conductive particle-containing region 1A, and the second region 2 in this order is, for example, a rubber-elastic particle-containing film, a conductive particle-containing film, and a second adhesive film. It can be obtained by laminating in this order.

The adhesive film 10 has conductive particles 4 dispersed in the first region 1 . As such, the adhesive film 10 can be an anisotropically conductive adhesive film. 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 the first circuit member and the second circuit member are heated. It may be used to crimp and electrically connect the first electrode and the second electrode to each other.

The laminated structure of the adhesive film 10 may be a two-region (layer) structure consisting of the first region 1 and the second region 2, or may be a structure of three or more regions (layers).

<First region (first adhesive layer)>
The first region 1 (first adhesive layer) comprises conductive particles 4 (hereinafter sometimes referred to as "(A) component") and rubber elastic particles 5 (hereinafter sometimes referred to as "(B) component"). ), and (first) adhesive component (hereinafter sometimes referred to as “(C) component”).

(A) component: conductive particles The component (A) is not particularly limited as long as it is a particle having conductivity, metal particles composed of metals such as Au, Ag, Pd, Ni, Cu, solder, conductive carbon It may be a conductive carbon particle or the like composed of. The component (A) may contain at least one metal selected from the group consisting of gold, palladium and nickel. Component (A) is a coated conductive particle comprising a nucleus containing non-conductive glass, ceramic, plastic (such as polystyrene), etc., and a coating layer containing the above metal or conductive carbon and covering the nucleus. good. Among these, the component (A) preferably comprises a core containing metal particles made of a heat-fusible metal or plastic, and a coating layer containing a metal or conductive carbon and covering the core. particles. With such coated conductive particles, the cured product of the thermosetting resin component can be easily deformed by heating or pressing. It is possible to increase the contact area and further improve the conductivity between the electrodes.

Component (A) is an insulating coated conductive particle comprising the above metal particles, conductive carbon particles, or coated conductive particles, and an insulating material such as a resin, and an insulating layer covering the surface of the particles. good. When the component (A) is an insulating coating conductive particle, even if the content of the component (A) is large, the surface of the particle is coated with a resin, so that the short circuit due to the contact between the components (A) The occurrence can be suppressed, and the insulation between adjacent electrode circuits can be improved. As the component (A), one of the various conductive particles described above may be used alone, or two or more thereof may be used in combination.

The maximum particle size of component (A) must be smaller than the minimum distance between electrodes (the shortest distance between adjacent electrodes). The maximum particle size of component (A) may be 1.0 μm or more, 2.0 μm or more, or 2.5 μm or more from the viewpoint of excellent dispersibility and conductivity. The maximum particle size of 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, for 300 arbitrary conductive particles (pcs), the particle size is measured by observation using a scanning electron microscope (SEM), and the largest value obtained is the maximum particle size of the component (A) and When the component (A) is not spherical, such as when the component (A) has projections, the particle size of the component (A) is the diameter of a circle circumscribing the conductive particles in the SEM image.

The average particle size of component (A) may be 1.0 μm or more, 2.0 μm or more, or 2.5 μm or more from the viewpoint of excellent dispersibility and conductivity. The average particle size of 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, 300 arbitrary conductive particles (pcs) are observed with a scanning electron microscope (SEM) to measure the particle size, and the average value of the obtained particle sizes is defined as the average particle size.

The component (A) is preferably dispersed uniformly in the first region 1 (first adhesive layer) and a conductive particle-containing region 1A (conductive particle-containing layer) which will be described later. From the viewpoint of obtaining stable connection resistance, the particle density of the component (A) in the adhesive film 10 is 100 particles/ ^mm2 or more, 1000 particles/ ^mm2 or more, 3000 particles/ ^mm2 or more, or 5000 particles/mm2. It may be ² or more. The particle density of the component (A) in the adhesive film 10 is 100,000 particles/mm ² or less, 70,000 particles/mm ² or less, 50,000 particles/mm ² or less, or 30,000 from the viewpoint of improving the insulation between adjacent electrodes. pcs/mm ² or less.

From the viewpoint of further improving conductivity, the content of component (A) is 1% by mass or more, 5% by mass or more, based on the total mass of the first region (first adhesive layer). Alternatively, it may be 10% by mass or more. The content of component (A) is 60% by mass or less, 50% by mass or less, or 40% by mass, based on the total mass of the first region (first adhesive layer), from the viewpoint of easily suppressing short circuits. may be: When the content of component (A) is within the above range, the effects of the present disclosure tend to be remarkably exhibited. The content of the component (A) in the composition or composition layer for forming the first region 1 (first adhesive layer) may be the same as the above range.

Component (B): Rubber elastic particles By containing the component (B) in the first region 1, the adhesive film 10 has excellent adhesion to the plastic substrate before curing and adhesion to the plastic substrate after curing. It has excellent adhesion.

Component (B) is not particularly limited as long as it is a particle having rubber elasticity.

Core-shell type rubber particles are formed by grafting a polymer different from the core component onto the surface of a particulate core component containing a crosslinked rubbery polymer as a main component, at least partially on the surface of the particulate core component. means coated rubber particles.

Examples of core components include crosslinked rubber particles. Examples of crosslinked rubber particles include butadiene rubber, styrene/butadiene rubber, acrylic rubber, silicone rubber, butyl rubber, nitrile rubber, styrene rubber, synthetic natural rubber, and ethylene/propylene rubber.

The shell component includes, for example, a polymer polymerized from at least one monomer selected from the group consisting of (meth)acrylic acid esters and aromatic vinyl compounds. The shell component may be graft polymerized to the core component. When styrene-butadiene rubber is used as the core component, the shell component is preferably a polymer of methyl methacrylate and styrene.

EXL-2655 (manufactured by Dow Chemical Japan Co., Ltd.), AC-4030, AC-3355, AC-3816, F351, GMX-0810 (manufactured by Aica Kogyo Co., Ltd.) and the like can be used as the core-shell type rubber particles.

The silicone rubber particles are not particularly limited as long as they are rubber particles made of polysiloxane. are coated with a shell component containing a three-dimensional crosslinked silicone as a main component. Examples of silicone rubber particles that can be used include KMP-605, KMP-600, KMP-597 and KMP-594 (manufactured by Shin-Etsu Chemical Co., Ltd.).

The average particle diameter of the component (B) may be 3 μm or less, 2 μm or less, 1 μm or less, or 0.7 μm or less from the viewpoint that the connection of the electrodes by the (A) component is hardly hindered. The average particle size of component (A) may be 0.01 μm or more, 0.05 μm or more, or 0.1 μm or more. In the present specification, the average particle size of component (B) can be measured by the following method. First, prepare a solution in which the component (B) is dispersed in methyl ethyl ketone. Next, the solution is measured with Microtrac MT-3000II (manufactured by Nikkiso Co., Ltd.). The average value of the measured values obtained by performing the measurement three times can be used as the average particle diameter of the component (B).

In the first region 1 (first adhesive layer) and the later-described rubber elastic particle-containing region 1B (rubber elastic particle-containing layer), the component (B) is preferably dispersed uniformly.

The content of component (B) is based on the total mass of the first region (first adhesive layer), from the viewpoint of adhesion to the plastic substrate before curing and adhesion to the plastic substrate after curing. , 0.1 mass % or more, 0.5 mass % or more, or 1 mass % or more, and may be 15 mass % or less, 10 mass % or less, or 5 mass % or less. When the content of component (B) is within the above range, the effects of the present disclosure tend to be remarkably exhibited. The content of the component (B) in the composition or composition layer for forming the first region 1 (first adhesive layer) may be the same as the above range.

(C) Component: Adhesive Component The (C) component includes a polymerizable compound (hereinafter sometimes referred to as "(C1) component") and a polymerization initiator (hereinafter sometimes referred to as "(C2) component"). ) etc. may be included. The component (C) may contain a curable resin component consisting of a combination of the component (C1) and the component (C2) and/or a cured product of the curable resin component.

The first adhesive component may contain a cured product of a photocurable resin component. In this case, the first adhesive component may contain a photopolymerization initiator as the (C2) component. The first region 1 (first adhesive layer) containing the first adhesive component containing the cured product of the photocurable resin component is, for example, the composition layer containing the photocurable resin component. It can be obtained by irradiating light energy to cure the photocurable resin component. The photocurable resin component may be a cationic curing system (a combination of the (C1C) component and the (C2CL) component described later), or a radical curing system (a combination of the (C1R) component and the (C2RL) component described later). may be

The first adhesive component may further contain a thermosetting resin component (first thermosetting resin component) in addition to the cured product of the photocurable resin component. In this case, the first adhesive component may further contain a thermal polymerization initiator as the (C2) component. The first region 1 (first adhesive layer) containing a first adhesive component containing a cured product of a photocurable resin component and a thermosetting resin component is, for example, a photocurable resin component and a thermosetting It can be obtained by irradiating a composition layer containing a photocurable resin component with light energy to cure the photocurable resin component. The first thermosetting resin component may be a cationic curing system (a combination of the (C1C) component and the (C2CH) component described later), or a radical curing system (the (C1R) component and the (C2RH) component described later). combination), preferably a cationic curing system. The curing system of the photocurable resin component and the curing system of the thermosetting resin component are preferably different, and the photocurable resin component is a radical curing system, and the thermosetting resin component is a cationic curing system. is more preferable.

(C1) component: polymerizable compound (C1) component is a cationically polymerizable compound (hereinafter sometimes referred to as "(C1C) component"), or a radically polymerizable compound (hereinafter referred to as "(C1R) component ) may be used.

(C1C) Component: Cationic Polymerizable Compound The (C1C) component is a compound that crosslinks by reacting with a cationic polymerization initiator (photocationic polymerization initiator, thermal cationic polymerization initiator, etc.). The (C1C) component means a compound that does not have a radically polymerizable group that reacts with radicals, and the (C1C) component is not included in the (C1R) component described below. Examples of the (C1C) component include polyfunctional epoxy compounds, polyfunctional oxetane compounds, and polyfunctional alicyclic epoxy compounds. The (C1C) component contains at least one selected from the group consisting of, for example, a polyfunctional oxetane compound and a polyfunctional alicyclic epoxy compound, from the viewpoint of further improving the effect of reducing the connection resistance and improving the connection reliability. may contain a polyfunctional alicyclic epoxy compound. (C1C) component may be used individually by 1 type, and may be used in combination of plurality.

Examples of polyfunctional epoxy compounds include bisphenol-type epoxy resins derived from epichlorohydrin and bisphenol compounds such as bisphenol A, bisphenol F, or bisphenol AD; epoxy novolak resin; various epoxy compounds having two or more glycidyl groups in one molecule such as glycidylamine, glycidyl ether, biphenyl, and alicyclic. One of these compounds may be used alone, or two or more of them may be used in combination.

As the polyfunctional oxetane compound, any compound having two or more oxetanyl groups and no radically polymerizable group can be used without particular limitation. Examples of commercially available oxetane compounds include OXBP (trade name, manufactured by Ube Industries, Ltd.), OXSQ, OXT-121, and OXT-221 (trade name, manufactured by Toagosei Co., Ltd.). One of these compounds may be used alone, or two or more of them may be used in combination.

As the polyfunctional alicyclic epoxy compound, any compound having two or more alicyclic epoxy groups (for example, an epoxycyclohexyl group) and no radically polymerizable group can be used without particular limitation. Examples of commercially available alicyclic epoxy compounds include CEL8000, CEL8010, CEL2021P, and CEL2081 (trade name, manufactured by Daicel Corporation). One of these compounds may be used alone, or two or more of them may be used in combination.

Among these, the first region 1 (first adhesive layer) or the later-described rubber elastic particle-containing region 1B (rubber elastic particle-containing layer) has superior adhesive strength to the plastic substrate after curing, so ( It is preferable to include a polyfunctional alicyclic epoxy compound as the C1C) component. Further, when the first region 1 (first adhesive layer) or the later-described rubber elastic particle-containing region 1B (rubber elastic particle-containing layer) contains a polyfunctional alicyclic epoxy compound as the (C1C) component, In addition to the polyfunctional alicyclic epoxy compound, it is preferable to further contain a polyfunctional oxetane compound, since the adhesive strength to the plastic substrate is even more excellent.

(C1R) Component: Radically Polymerizable Compound The (C1R) component is a compound polymerized by radicals generated from a radical polymerization initiator (photoradical polymerization initiator, thermal radical polymerization initiator component, etc.). The (C1R) component may be either a monomer or a polymer (or oligomer) obtained by polymerizing one or more monomers. The (C1R) component may be used singly or in combination.

The (C1R) component is a compound having a radically polymerizable group that reacts with radicals. Examples of radically polymerizable groups include (meth)acryloyl groups, vinyl groups, allyl groups, styryl groups, alkenyl groups, alkenylene groups, maleimide groups and the like. The number of radically polymerizable groups (number of functional groups) of the (C1R) component is 2 or more from the viewpoint that the desired melt viscosity is easily obtained after polymerization, the effect of reducing the connection resistance is further improved, and the connection reliability is excellent. from the viewpoint of suppressing curing shrinkage during polymerization, it may be 10 or less. In addition to the compound having the number of radically polymerizable groups within the above range, a compound having the number of radically polymerizable groups outside the above range may also be used in order to balance the crosslink density and cure shrinkage. good.

The (C1R) component may contain, for example, a polyfunctional (bifunctional or higher) (meth)acrylate from the viewpoint of suppressing the flow of the conductive particles. The polyfunctional (bifunctional or higher) (meth)acrylate may be a bifunctional (meth)acrylate, and the bifunctional (meth)acrylate may be a bifunctional aromatic (meth)acrylate.

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. ) 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, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate (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, glycerine di(meth)acrylate, tricyclodecanedimethanol (meth)acrylate, ethoxylated 2-methyl-1,3-propanediol di(meth)acrylate and other aliphatic ( meth)acrylate; 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 Aromatic (meth)acrylates such as di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, ethoxylated propoxylated tri(meth)acrylate Methylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tri (Meth)acrylates, 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 Aliphatic (meth)acrylates such as (meth)acrylates, ethoxylated propoxylated pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetraacrylate, and dipentaerythritol hexa(meth)acrylate; bisphenol type epoxy (meth)acrylate, phenol novolac Aromatic epoxy (meth)acrylates such as type epoxy (meth)acrylate and cresol novolac type epoxy (meth)acrylate.

The content of the polyfunctional (difunctional or higher) (meth)acrylate is, for example, 40 to 100 based on the total mass of the (C1R) component from the viewpoint of achieving both the effect of reducing the connection resistance and the suppression of particle flow. % by weight, 50-100% by weight, or 60-100% by weight.

The (C1R) component may further contain a monofunctional (meth)acrylate in addition to the polyfunctional (bifunctional or higher) (meth)acrylate. Monofunctional (meth)acrylates include, for example, (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 acrylates 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxy Aliphatic (meth)acrylates such as polyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, mono(2-(meth)acryloyloxyethyl)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, phenoxypolyethyleneglycol (meth)acrylate, nonylphenoxypolyethyleneglycol (meth)acrylate, phenoxypolypropyleneglycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-(o-phenylphenoxy)propyl (meth)acrylate, 2-hydroxy-3-(1-naphthoxy)propyl (meth)acrylate, 2- Aromatic (meth)acrylates such as hydroxy-3-(2-naphthoxy)propyl (meth)acrylate; (meth)acrylates having an epoxy group such as glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate (Meth)acrylates with alicyclic epoxy groups such as ( Examples thereof include (meth)acrylates having an oxetanyl group such as 3-ethyloxetan-3-yl)methyl (meth)acrylate.

The monofunctional (meth)acrylate content may be, for example, 0 to 60% by weight, 0 to 50% by weight, or 0 to 40% by weight, based on the total weight of the (C1R) component.

The (C1R) component may contain other radically polymerizable compounds in addition to polyfunctional (difunctional or higher) and monofunctional (meth)acrylates. Other radically polymerizable compounds include, for example, maleimide compounds, vinyl ether compounds, allyl compounds, styrene derivatives, acrylamide derivatives, nadimide derivatives and the like. The content of other radically polymerizable compounds may be, for example, 0 to 40% by mass based on the total mass of the (C1R) component.

(C2) component: polymerization initiator When the (C1) component is the (C1C) component, the (C2) component is a photocationic polymerization initiator (hereinafter sometimes referred to as the “(C2CL) component”), may also be a thermal cationic polymerization initiator (hereinafter sometimes referred to as "(C2CH) component"). By combining the (C1C) component and the (C2CL) component, a photocurable resin component can be obtained. A thermosetting resin component can be obtained by combining the (C1C) component and the (C2CH) component.

(C2CL) component: photo cationic polymerization initiator (C2CL) component contains light containing a wavelength within the range of 150 to 750 nm, preferably light containing a wavelength within the range of 254 to 405 nm, more preferably light containing a wavelength of 365 nm It is a polymerization initiator that generates a substance that initiates cationic polymerization when irradiated with light (eg, ultraviolet light). The (C2CL) component may act as the (C2CH) component described later.

The (C2CL) component is, for example, BF ₄ ⁻ , BR ₄ ⁻ (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups), PF ₆ ⁻ , SbF ₆ ⁻ and onium salts such as sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, and anilinium salts having anions such as AsF ₆ ^— . These may be used individually by 1 type, and may be used in combination of plurality.

Commercially available products of the (C2CL) component include, for example, CPI-100P, CPI-110P, CPI-101A, CPI-200K, CPI-210S (all manufactured by San-Apro Co., Ltd.), UVI-6990, UVI-6992, UVI- 6976 (all manufactured by Dow Chemical Japan Co., Ltd.), SP-150, SP-152, SP-170, SP-172, SP-300 (all manufactured by ADEKA Corporation) and the like.

The content of the (C2CL) component is 100 parts by mass of the (C1C) component from the viewpoint of ensuring the formability and curability of the adhesive film for forming the first region (first adhesive layer). For example, it may be 0.1 to 15 parts by weight, 0.3 to 12 parts by weight, 0.5 to 10 parts by weight, or 1 to 5 parts by weight.

(C2CH) Component: Thermal Cationic Polymerization Initiator The (C2CH) component is a polymerization initiator that generates a substance that initiates cationic polymerization by heat (eg, 40 to 150° C.). The (C2CH) component may act as the (C2CL) component described above.

The (C2CH) component is similar to the (C2CL) component, for example, BF ₄ ⁻ , BR ₄ ⁻ (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups.) , PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , and onium salts such as sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, iodonium salts, and anilinium salts. These may be used individually by 1 type, and may be used in combination of plurality.

Commercially available products of the (CCH) component include, for example, CP-66, CP-77 (both manufactured by ADEKA Corporation), SI-25, SI-45, SI-60, SI-60L, SI-60LA, SI- 60B, SI-80L, SI-100L, SI-110L, SI-180L (all manufactured by Sanshin Chemical Industry Co., Ltd.), CI-2855 (manufactured by Nippon Soda Co., Ltd.), PI-2074 (manufactured by Rhodia Japan Co., Ltd.) ) and the like.

The content of the (CCH) component is 100 parts by mass of the (C1C) component from the viewpoint of ensuring the formability and curability of the adhesive film for forming the first region (first adhesive layer). For example, it may be 0.1 to 50 parts by weight, 0.5 to 40 parts by weight, 1 to 30 parts by weight, or 5 to 20 parts by weight.

When the (C1) component is the (C1R) component, the (C2) component may be a photoradical polymerization initiator (hereinafter sometimes referred to as the "(C2RL) component"), or a thermal radical polymerization initiator ( Hereinafter, it may be referred to as “(C2RH) component”.). By combining the (C1R) component and the (C2RL) component, a photocurable resin component can be obtained. A thermosetting resin component can be obtained by combining the (C1R) component and the (C2RH) component.

(C2RL) component: photoradical polymerization initiator (C2RL) component contains light containing a wavelength within the range of 150 to 750 nm, preferably light containing a wavelength within the range of 254 to 405 nm, more preferably light containing a wavelength of 365 nm It is a polymerization initiator that generates radicals when irradiated with light (eg, ultraviolet light). The (C2RL) component may be used singly or in combination.

The (C2RL) component is decomposed by light to generate free radicals. That is, the (C2RL) component is a compound that generates radicals upon application of external light energy. The (C2RL) component has an oxime ester structure, a bisimidazole structure, an acridine structure, an α-aminoalkylphenone structure, an aminobenzophenone structure, an N-phenylglycine structure, an acylphosphine oxide structure, a benzyldimethylketal structure, and an α-hydroxyalkylphenone structure. It may be a compound having a structure such as The (C2RL) component may be used singly or in combination. The (C2RL) component is 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 the desired melt viscosity and from the viewpoint of being more excellent in the effect of reducing connection resistance. It may be a compound having at least one structure of

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

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

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

The content of the (C2RL) component is, for example, 0.1 to 10 parts by mass, 0.3 to 7 parts by mass, or 0 with respect to 100 parts by mass of the (C1R) component from the viewpoint of suppressing the flow of the conductive particles. .5 to 5 parts by mass.

(C2RH) Component: Thermal Radical Polymerization Initiator The (C2RH) component is a polymerization initiator that generates radicals by heat. The one hour half-life temperature of the (C2RH) component may be, for example, between 50 and 100°C. The (C2RH) component may be used singly or in combination.

(C2RH) components include, for example, octanoyl peroxide, lauroyl peroxide, stearyl peroxide, diacyl peroxide such as benzoyl peroxide; t-butyl peroxypivalate, t-hexyl peroxypivalate, 1,1 , 3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexa noate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate , t-butyl peroxylaurylate, t-butyl peroxy isopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, 2,5-dimethyl- Peroxy esters such as 2,5-bis(benzoylperoxy)hexane, t-butyl peroxyacetate; and 2,2′-azobisisobutyronitrile, 2,2′-azobis(2,4-dimethyl valeronitrile), and azo compounds such as 2,2'-azobis(4-methoxy-2'-dimethylvaleronitrile).

The content of the (C2RH) component is, from the viewpoint of suppressing the flow of the conductive particles, relative to 100 parts by mass of the (C1R) component, for example, 0.1 to 15 parts by mass, 0.3 to 12 parts by mass, or 0 .5 to 10 parts by mass.

The component (C) (first adhesive component) may contain a cured product of a photocurable resin component. The content of the cured product of the photocurable resin component is 40 to 100% by mass, 50 to 100% by mass, or 60 to 100% by mass based on the total mass of component (C) (first adhesive component). can be The content of the photocurable resin component in the composition or composition layer for forming the first region 1 (first adhesive layer) may be the same as the above range.

The (C) component (first adhesive component) may further contain a thermosetting resin component in addition to the cured product of the photocurable resin component. The content of the thermosetting resin component is 0 to 60% by mass, 0 to 50% by mass, or 0 to 40% by mass, based on the total mass of component (C) (first adhesive component). good. The content of the thermosetting resin component in the composition or composition layer for forming the first region 1 (first adhesive layer) may be the same as the above range.

(C) The content of the component (first adhesive component) is the first region (first adhesive layer) from the viewpoint of ensuring the curability of the adhesive film for forming the first region (first adhesive layer). Based on the total mass of the (first adhesive layer), it may be 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more. The content of the component (C) (first adhesive component) is the first region (first adhesive layer) from the viewpoint of ensuring the formability of the adhesive film for forming the first region (first adhesive layer). It may be 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less based on the total mass of the (first adhesive layer). When the content of component (C) (first adhesive component) is within the above range, the effects of the present disclosure tend to be remarkably exhibited. The content of the component (C) (first adhesive component) in the composition or composition layer for forming the first region 1 (first adhesive layer) is the same as the above range. you can

• Other components The first region 1 (first adhesive layer) may further contain other components in addition to the components (A), (B), and (C). Other components include, for example, a thermoplastic resin (hereinafter sometimes referred to as "(D) component"), a coupling agent (hereinafter sometimes referred to as "(E) component"), a filler (hereinafter sometimes referred to as "(E) component"), , and may be referred to as “(F) component”).

Component (D): Thermoplastic resin Examples of component (D) include phenoxy resins, polyester resins, polyamide resins, polyurethane resins, polyester urethane resins, acrylic rubbers, epoxy resins (solid at 25°C), polyvinyl acetal resins, and the like. mentioned. These may be used individually by 1 type, and may be used in combination of plurality. A composition layer (and a first adhesive layer) is formed from the composition by further containing the component (D) in the composition containing the components (A), (B), and (C). It can be easily formed. Among these, the (D) component may be, for example, a phenoxy resin.

The content of component (D) is 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 region (first adhesive layer). may be 70% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less. The content of the component (D) in the composition or composition layer for forming the first region 1 (first adhesive layer) may be the same as the above range.

Component (E): Coupling agent Component (E) includes, for example, a (meth)acryloyl group, a mercapto group, an amino group, an imidazole group, a silane coupling agent having an organic functional group such as an epoxy group, a tetraalkoxysilane, and the like. silane compounds, tetraalkoxytitanate derivatives, polydialkyltitanate derivatives, and the like. These may be used individually by 1 type, and may be used in combination of plurality. By including the component (F) in the first adhesive layer, the adhesiveness can be further improved. The (E) component 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 region (first adhesive layer). The content of the component (E) in the composition or composition layer for forming the first region 1 (first adhesive layer) may be the same as the above range.

(F) Component: Filler Examples of the component (F) include non-conductive fillers (eg, non-conductive particles). (F) Component may be either an inorganic filler or an organic filler. Examples of inorganic fillers include metal oxide fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles and zirconia fine particles; and inorganic fine particles such as metal nitride fine particles. Examples of the organic filler include organic fine particles such as silicone fine particles, methacrylate/butadiene/styrene fine particles, acryl/silicone fine particles, polyamide fine particles, and polyimide fine particles. These may be used individually by 1 type, and may be used in combination of plurality. The (F) component may be silica fine particles, for example. The content of component (F) may be 0.1 to 10% by mass based on the total mass of the first region (first adhesive layer). The content of the component (F) in the composition or composition layer for forming the first region 1 (first adhesive layer) may be the same as the above range.

· Other additives The first region 1 (first adhesive layer) further contains other additives such as softeners, accelerators, antidegradants, colorants, flame retardants, and thixotropic agents. You may have The content of other additives may be, for example, 0.1 to 10% by mass based on the total mass of the first region (first adhesive layer). The content of other additives in the composition or composition layer for forming the first region 1 (first adhesive layer) may be the same as the above range.

The thickness d1 of the first region 1 may be, for example, 8.0 μm or less. The thickness d1 of the first region 1 may be 7.0 μm or less or 6.0 μm or less. When the thickness d1 of the first region 1 is 5 μm or less, conductive particles can be more efficiently captured during circuit connection. The thickness d1 of the first region 1 may be, for example, 0.2 μm or more, 0.8 μm or more, or 1.2 μm or more.

The thickness d1 of the first region 1 is obtained by, for example, sandwiching the adhesive film between two sheets of glass (thickness: about 1 mm) and adding 100 g of bisphenol A type epoxy resin (trade name: JER811, manufactured by Mitsubishi Chemical Corporation). , and 10 g of a curing agent (trade name: Epomount curing agent, manufactured by Refinetech Co., Ltd.). SE-8020, manufactured by Hitachi High-Tech Science Co., Ltd.). Moreover, as shown in FIG. 1, when a part of the conductive particles 4 is exposed from the surface of the first region 1 (for example, protrudes toward the second region 2), the first region 1 and the polyvinyl The distance from the boundary S1B with the acetal resin-containing region 3 to the boundary S2 between the first region 1 and the second region 2 located in the spaced part between the adjacent conductive particles 4, 4 (distance indicated by d1 in FIG. 1) ) is the thickness of the first region 1 , and the exposed portion of the conductive particles 4 is not included in the thickness of the first region 1 . The length of the exposed portion of the conductive particles 4 may be, for example, 0.1 μm or more and 5 μm or less.

On the other hand, when the adhesive film is produced by laminating a first adhesive film and a second adhesive film, for example, the thickness of the first adhesive film is easily maintained in the adhesive film. , the thickness of the first adhesive film may be the thickness d1 of the first region 1 . When part of the conductive particles is exposed from the surface of the first adhesive film, the exposed part of the conductive particles is not included in the thickness of the first adhesive film.

The first region 1 may include a conductive particle-containing region 1A and a rubber elastic particle-containing region 1B in this order from the second region 2 side.

(Conductive particle-containing region)
The conductive particle-containing region 1A may contain components (A) and (C) (first A adhesive component). The 1A adhesive component can be exemplified by the same as the first adhesive component. The conductive particle-containing region 1A may further contain other components ((D) component, (E) component, and (F) component), other additives, and the like.

The content of component (A) may be 1% by mass or more, 5% by mass or more, or 10% by mass or more based on the total mass of the conductive particle-containing region (conductive particle-containing layer). The content of component (A) may be 60% by mass or less, 50% by mass or less, or 40% by mass or less based on the total mass of the conductive particle-containing region (conductive particle-containing layer). When the content of component (A) is within the above range, the effects of the present disclosure tend to be remarkably exhibited. The content of the component (A) in the composition or composition layer for forming the conductive particle-containing region 1A (conductive particle-containing layer) may be the same as the above range.

The conductive particle-containing region 1A preferably does not substantially contain the component (B). Here, substantially not containing means that the content of the component (B) is 5% by mass or less, 3% by mass or less, or 1% by mass, based on the total mass of the conductive particle-containing region (conductive particle-containing layer) % or less.

The (C) component (first A adhesive component) may contain a cured product of a photocurable resin component. The content of the cured product of the photocurable resin component is 40 to 100% by mass, 50 to 100% by mass, or 60 to 100% by mass based on the total mass of component (C) (first A adhesive component). can be The content of the photocurable resin component in the composition or composition layer for forming the conductive particle-containing region 1A (conductive particle-containing layer) may be the same as the above range.

The component (C) (1A adhesive component) may further contain a thermosetting resin component (1A thermosetting resin component) in addition to the cured product of the photocurable resin component. The first A thermosetting resin component is a cationic curing system (combination of (C1C) component and (C2CH) component) or a radical curing system (combination of (C1R) component and (C2RH) component). However, it is preferably a cationic curing system. The content of the 1A thermosetting resin component is 0 to 60% by mass, 0 to 50% by mass, or 0 to 40% by mass, based on the total mass of the component (C) (1A adhesive component). can be The content of the thermosetting resin component in the composition or composition layer for forming the conductive particle-containing region 1A (conductive particle-containing layer) may be the same as the above range.

The content of the component (C) (first A adhesive component) is 5% by mass or more, 10% by mass or more, 15% by mass or more, based on the total mass of the conductive particle-containing region 1A (conductive particle-containing layer), Alternatively, it may be 20% by mass or more. The content of the component (C) (first A adhesive component) is 80% by mass or less, 70% by mass or less, 60% by mass or less, based on the total mass of the conductive particle-containing region 1A (conductive particle-containing layer), Or it may be 50% by mass or less. When the content of the component (C) (first A adhesive component) is within the above range, the effects of the present disclosure tend to be remarkably exhibited. The content of the component (C) (1A adhesive component) in the composition or composition layer for forming the conductive particle-containing region 1A (conductive particle-containing layer) may be the same as the above range. .

The content of component (D) is 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 conductive particle-containing region 1A (conductive particle-containing layer). Well, it may be 70% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less. The content of component (D) in the composition or composition layer for forming the conductive particle-containing region (conductive particle-containing layer) may be the same as the above range.

The content of component (E) may be 0.1 to 10% by mass based on the total mass of the conductive particle-containing region (conductive particle-containing layer). The content of component (E) in the composition or composition layer for forming the conductive particle-containing region (conductive particle-containing layer) may be the same as the above range.

The content of component (F) may be 0.1 to 10% by mass based on the total mass of the conductive particle-containing region (conductive particle-containing layer). The content of component (F) in the composition or composition layer for forming the conductive particle-containing region (conductive particle-containing layer) may be the same as the above range.

The thickness d1A of the conductive particle-containing region 1A may be, for example, 5.0 μm or less, 4.5 μm or less, or 4.0 μm or less, and may be 0.1 μm or more, 0.5 μm or more, or 0.7 μm or more. you can The thickness d1A of the conductive particle-containing region 1A can be determined by the same method as the thickness d1 of the first region 1. Also, the thickness of the conductive particle-containing film may be the thickness d1A of the conductive particle-containing region 1A.

(Rubber elastic particle-containing region)
The rubber-elastic particle-containing region 1B may contain the (B) component and the (C) component (first B adhesive component). The 1B adhesive component can be exemplified by the same as the first adhesive component. The rubber elastic particle-containing region 1B may further contain other components ((D) component, (E) component, and (F) component), other additives, and the like.

The content of component (B) is based on the total mass of the rubber elastic particle-containing region (rubber elastic particle-containing layer), from the viewpoint of adhesion to the plastic substrate before curing and adhesion to the plastic substrate after curing. , 0.1 mass % or more, 0.5 mass % or more, or 1 mass % or more, and may be 15 mass % or less, 10 mass % or less, or 5 mass % or less. When the content of component (B) is within the above range, the effects of the present disclosure tend to be remarkably exhibited. The content of component (B) in the composition or composition layer for forming the rubber elastic particle-containing region (rubber elastic particle-containing layer) may be the same as the above range.

The rubber elastic particle-containing region 1B preferably does not substantially contain component (A). Here, "substantially free" means that the content of component (A) is 5% by mass or less, 3% by mass or less, based on the total mass of the rubber elastic particle-containing region (rubber elastic particle-containing layer), or It means that it is 1% by mass or less.

The (C) component (1B adhesive component) may be a thermosetting resin component (1B thermosetting resin component). In this case, the 1B adhesive component may contain a thermal polymerization initiator as the (C2) component. The 1B thermosetting resin component is a cationic curing system (combination of (C1C) component and (C2CH) component) or a radical curing system (combination of (C1R) component and (C2RH) component). However, it is preferably a cationic curing system. The 1B thermosetting resin component may be the same as or different from the 1A thermosetting resin component, but preferably has a common curing system.

The content of component (C) (1B adhesive component) is 5% by mass or more, 10% by mass or more, or 15% by mass or more based on the total mass of the rubber elastic particle-containing region (rubber elastic particle-containing layer). , or 20% by mass or more. The content of component (C) (1B adhesive component) is 80% by mass or less, 70% by mass or less, or 60% by mass or less based on the total mass of the rubber elastic particle-containing region (rubber elastic particle-containing layer). , or 50% by mass or less. When the content of component (C) (first B adhesive component) is within the above range, the effects of the present disclosure tend to be remarkably exhibited. The content of component (C) (1B adhesive component) in the composition or composition layer for forming the rubber elastic particle-containing region (rubber elastic particle-containing layer) is the same as the above range. good.

The content of component (D) is 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 rubber elastic particle-containing region (rubber elastic particle-containing layer). may be 70% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less. The content of component (D) in the composition or composition layer for forming the rubber elastic particle-containing region (rubber elastic particle-containing layer) may be the same as the above range.

The content of component (E) may be 0.1 to 10% by mass based on the total mass of the rubber elastic particle-containing region (rubber elastic particle-containing layer). The content of component (E) in the composition or composition layer for forming the rubber elastic particle-containing region (rubber elastic particle-containing layer) may be the same as the above range.

The content of component (F) may be 0.1 to 10% by mass based on the total mass of the rubber elastic particle-containing region (rubber elastic particle-containing layer). The content of component (F) in the composition or composition layer for forming the rubber elastic particle-containing region (rubber elastic particle-containing layer) may be the same as the above range.

The thickness d1B of the rubber elastic particle-containing region 1B may be, for example, 3.0 μm or less, 2.5 μm or less, or 2.0 μm or less, and may be 0.1 μm or more, 0.3 μm or more, or 0.5 μm or more. It's okay. The thickness d1B of the rubber-elastic particle-containing region 1B can be obtained by the same method as the thickness d1 of the first region 1. Alternatively, the thickness of the rubber elastic particle-containing film may be the thickness d1B of the rubber elastic particle-containing region 1B.

<Second Region (Second Adhesive Layer)>
The second region 2 (second adhesive layer) may contain component (C) (second adhesive component). The second adhesive component may be the same or different than the first adhesive component.

The (C) component (second adhesive component) may contain the (C1) component, the (C2) component, and the like. The component (C) may contain a curable resin component consisting of a combination of the component (C1) and the component (C2) and/or a cured product of the curable resin component.

The component (C) (second adhesive component) may be a thermosetting resin component (second thermosetting resin component). In this case, the second adhesive component may contain a thermal polymerization initiator as the (C2) component. The thermosetting resin component may be a cationic curing system (a combination of the (C1C) component and the (C2CH) component) or a radical curing system (a combination of the (C1R) component and the (C2RH) component). Often, cationic curing systems are preferred. The second thermosetting resin component may be the same as or different from the first thermosetting resin component, but preferably has a common curing system.

(C) The content of the component (second adhesive component) is the second region (second adhesive layer) from the viewpoint of ensuring the curability of the adhesive film for forming the second region (second adhesive layer). It may be 10% by mass or more, 20% by mass or more, 30% by mass or more, or 40% by mass or more based on the total mass of the (second adhesive layer). The content of the component (C) (second adhesive component) is the second region (second adhesive layer) from the viewpoint of ensuring the formability of the adhesive film for forming the second region (second adhesive layer). It may be 80% by mass or less, 70% by mass or less, 60% by mass or less, or 55% by mass or less based on the total mass of the (second adhesive layer). When the content of component (C) (second adhesive component) is within the above range, the effects of the present disclosure tend to be remarkably exhibited. In addition, the content of the component (C) (second adhesive component) in the composition or composition layer for forming the second region (second adhesive layer) (of the composition or composition layer) total mass) may be similar to the above range.

The second region 2 (second adhesive layer) may further contain other components and additives in the first region 1 (first adhesive layer). Preferred aspects of other components and other additives are the same as those of the first region 1 (first adhesive layer).

The content of component (D) is 1% by mass or more, 5% by mass or more, 10% by mass or more, or 15% by mass or more based on the total mass of the second region (second adhesive layer). may be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less. The content of component (D) in the composition or composition layer for forming the second region (second adhesive layer) may be the same as the above range.

The content of component (E) may be 0.1 to 10% by mass based on the total mass of the second region (second adhesive layer). The content of component (E) in the composition or composition layer for forming the second region (second adhesive layer) may be the same as the above range.

The content of component (F) may be 0.1 to 10% by mass based on the total mass of the second region (second adhesive layer). The content of component (F) in the composition or composition layer for forming the second region (second adhesive layer) may be the same as the above range.

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

The thickness d2 of the second region 2 may be appropriately set according to the height of the electrode of the circuit member to be adhered. The thickness d2 of the second region 2 is 3.0 μm or more and 5.0 μm, from the viewpoint that the space between the electrodes can be sufficiently filled and the electrodes can be sealed, and better connection reliability can be obtained. or more, or 7.0 μm or more, and may be 20 μm or less, 15 μm or less, or 12 μm or less.

The thickness d2 of the second region 2 can be obtained by the same method as the thickness d1 of the first region 1. FIG. In addition, when a part of the conductive particles 4 is exposed from the surface of the first region 1 (for example, protrudes to the second region 2 side), the second region 2 is opposite to the first region 1 side The distance from the main surface 2a on the side to the boundary S2 between the first region 1 and the second region 2 located in the spaced part of the adjacent conductive particles 4, 4 (the distance indicated by d2 in FIG. 1) is the second is the thickness of region 2 of

On the other hand, when the adhesive film is produced by laminating the first adhesive film and the second adhesive film, for example, the thickness of the second adhesive film is easily maintained in the adhesive film. , the thickness of the second adhesive film may be the thickness d2 of the second region 2 .

The thickness of the adhesive film 10 (total thickness of all layers constituting the adhesive film 10) may be, for example, 3.2 μm or more, 5.8 μm or more, or 7.2 μm or more, and 28 μm or less. , 22 μm or less, or 18 μm or less.

The circuit-connecting adhesive film of the above embodiment is an anisotropic conductive adhesive film, but the circuit-connecting adhesive film may be a conductive adhesive film that does not exhibit anisotropic conductivity.

[Method for producing circuit-connecting adhesive film]
In one embodiment of the method for producing an adhesive film for circuit connection, a first adhesive layer containing components (A), (B), and (C) (first adhesive component) is formed. a step (first step); and a step of laminating a second adhesive layer containing component (C) (second adhesive component) on the first adhesive layer (second step). Prepare. The first step includes forming a conductive particle-containing layer containing component (A) (and component (C) (first A adhesive component), component (B) (and component (C) (first B and forming a first adhesive layer by laminating the conductive particle-containing layer and the rubber elastic particle-containing layer together. good too.

In the first step, for example, first, a composition containing (A) component, (B) component, and (C) component, and other components and other additives added as necessary, is organically A varnish composition is prepared by dissolving or dispersing by stirring, mixing, kneading, or the like in a solvent. After that, the varnish composition is applied to the base material that has been subjected to the release treatment using a knife coater, roll coater, applicator, comma coater, die coater, etc., and then the organic solvent is volatilized by heating, and the Then, a composition layer (first adhesive layer) made of the composition is formed. At this time, the thickness of the finally obtained first adhesive layer (first adhesive film) can be adjusted by adjusting the coating amount of the varnish composition.

When the component (C) (the first adhesive component) contains a photocurable resin component, the first step includes the component (A), the component (B), and the component (C) containing the photocurable resin component. may be a step of curing a photocurable resin component on a composition layer made of a composition containing to form a first adhesive layer. At this time, the composition may contain a thermosetting resin component. In this case, in the first step, the composition layer made of the composition is irradiated with light to cure the photocurable resin component in the composition layer, thereby forming the first adhesive layer on the substrate. do. The first adhesive layer can be referred to as a first adhesive film.

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, butyl acetate and the like. These organic solvents can be used alone or in combination of two or more. Stirring and mixing or kneading during preparation of the varnish composition can be performed using, for example, a stirrer, a kneader, a three-roll mill, a ball mill, a bead mill, a homodisper, or the like.

The substrate is not particularly limited as long as it has heat resistance that can withstand the heating conditions when volatilizing the organic solvent. Examples of such substrates include oriented polypropylene (OPP), polyethylene terephthalate (PET), polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate, polyolefin, polyacetate, polycarbonate, polyphenylene sulfide, polyamide, polyimide, cellulose, Substrates (for example, films) made of ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, synthetic rubber, liquid crystal polymer, or the like can be used.

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. The heating conditions may be, for example, 40-120° C. for 0.1-10 minutes.

Part of the organic solvent may remain in the first adhesive layer without being removed. The content of the organic solvent in the first adhesive layer may be, for example, 10% by mass or less based on the total mass of the first adhesive layer.

When light is used in the curing step, it is preferable to use light having a wavelength within the range of 150 to 750 nm (for example, ultraviolet light). Light irradiation can be performed using, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, an LED light source, or the like. The integrated amount of light irradiation can be appropriately set, and may be, for example, 500 to 3000 mJ/cm ² .

The conductive particle-containing layer and the rubber-elastic particle-containing layer can be formed, for example, in the same manner as the method for forming the first adhesive layer, except that the components contained therein are changed. The conductive particle-containing layer and the rubber elastic particle-containing layer can be referred to as a conductive particle-containing film and a rubber elastic particle-containing film.

A part of the organic solvent may remain in the conductive particle-containing layer and the rubber-elastic particle-containing layer without being removed. The content of the organic solvent in the conductive particle-containing layer may be, for example, 10% by mass or less based on the total mass of the conductive particle-containing layer. The content of the organic solvent in the rubber elastic particle-containing layer may be, for example, 10% by mass or less based on the total weight of the rubber elastic particle-containing layer.

Examples of methods for laminating the conductive particle-containing film and the rubber elastic particle-containing film include methods such as heat press, roll lamination, and vacuum lamination. Lamination can be performed, for example, under temperature conditions of 0 to 80°C.

The second step is laminating a second adhesive layer on the first adhesive layer. When the first adhesive layer includes a conductive particle-containing layer and a rubber-elastic particle-containing layer, the second adhesive layer is laminated on the conductive particle-containing layer. In the second step, for example, first, except for using the component (C) and other components and other additives added as necessary (and not performing light irradiation), the first step A second adhesive layer is formed on the substrate in the same manner as in , to obtain a second adhesive film. A second adhesive layer can then be laminated onto the first adhesive layer by laminating the first adhesive film and the second adhesive film together. Further, in the second step, for example, on the first adhesive layer (conductive particle-containing layer), (C) component, and other components and other additives that are added as necessary. The second adhesive layer can also be laminated on the first adhesive layer by applying the varnish composition obtained and volatilizing the organic solvent.

Part of the organic solvent may remain in the second adhesive layer without being removed. The content of the organic solvent in the second adhesive layer may be, for example, 10% by mass or less based on the total mass of the second adhesive layer.

The method for bonding the first adhesive film and the second adhesive film may be the same as the method for bonding the conductive particle-containing film and the rubber elastic particle-containing film.

[Circuit connection structure and its manufacturing method]
A circuit-connecting structure using the circuit-connecting adhesive film 10 as a circuit-connecting material and a method for producing the circuit-connecting structure will be described below.

FIG. 2 is a schematic cross-sectional view showing one embodiment of the circuit connection structure. As shown in FIG. 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 a main surface 11 a of the first circuit board 11 . , a second circuit member 16 having a second circuit board 14 and a second electrode 15 formed on a main surface 14a of the second circuit board 14, and a first circuit member 13 and a second circuit member 16 to electrically connect the first electrode 12 and the second electrode 15 to each other.

The first circuit member 13 and the second circuit member 16 may be the same or different. The first circuit member 13 and the second circuit member 16 are glass substrates or plastic substrates on which circuit electrodes are formed; printed wiring boards; ceramic wiring boards; flexible wiring boards; you can The first circuit board 11 and the second circuit board 14 may be made of inorganic materials such as semiconductors, glass, and ceramics, organic materials (plastics) such as polyimide and polycarbonate, composite materials such as glass/epoxy, and the like. The first circuit board 11 may be a plastic board or a polyimide board. The first circuit member 13 may be, for example, a plastic substrate on which circuit electrodes are formed, or a polyimide substrate on which circuit electrodes are formed. The second circuit member 16 may be, for example, an IC chip such as a driving IC.

The first electrode 12 and the second electrode 15 are metals such as gold, silver, tin, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, aluminum, molybdenum, titanium, indium tin oxide (ITO), Electrodes may include oxides such as indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), and the like. The first electrode 12 and the second electrode 15 may be electrodes formed by stacking two or more of these metals, oxides, and the like. The electrode formed by laminating two or more kinds may have two or more layers, or may have three or more layers. When 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. In FIG. 2, the first electrodes 12 are circuit electrodes, and the second electrodes 15 are bump electrodes.

The circuit connecting portion 17 contains the cured adhesive film 10 described above. The circuit connecting portion 17 may be made of the cured adhesive film 10 described above. The circuit connection portion 17 is positioned, for example, on the side of the first circuit member 13 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"), and is provided with the above-described rubber elasticity. Located on the second circuit member 16 side in the opposite direction to the cured product region 18B made of the cured product of the component (C) (first B adhesive component) in the particle-containing region, the (C ) component (second adhesive component), and (C) component (first A adhesive component) disposed between cured product region 18B and cured product region 19. and conductive particles 4 interposed between at least the first electrode 12 and the second electrode 15 to electrically connect the first electrode 12 and the second electrode 15 to each other. and Circuit connection portion 17 may not have three distinct regions between cured region 18B, cured region 18A, and cured region 19, as shown in FIG.

The circuit connection structure is, for example, a flexible organic electroluminescence color display (organic EL display) in which a plastic substrate on which organic EL elements are regularly arranged and a driving circuit element that is a driver for image display are connected, Examples include a touch panel in which a plastic substrate on which organic EL elements are arranged regularly and a position input element such as a touch pad are connected. The circuit connection structure can be applied to various monitors such as smartphones, tablets, televisions, vehicle navigation systems, and wearable terminals; furniture; home appliances;

FIG. 3 is a schematic cross-sectional view showing an embodiment of a method for manufacturing a circuit connection structure. 3A and 3B are schematic cross-sectional views showing each step. As shown in FIG. 3, the method of manufacturing the circuit connection structure 20 includes: between a first circuit member 13 having a first electrode 12 and a second circuit member 16 having a second electrode 15 A step of electrically connecting the first electrode 12 and the second electrode 15 to each other by thermocompression bonding the first circuit member 13 and the second circuit member 16 with the adhesive film 10 interposed therebetween. .

Specifically, first, as shown in FIG. A member 13 and a second circuit member 16 having a second circuit board 14 and a second electrode 15 formed on the main surface 14a of the second circuit board 14 are prepared.

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 first circuit member 13 and the second circuit member An adhesive film 10 is placed between 16 . For example, as shown in FIG. 3A, the adhesive film 10 is laminated on the first circuit member 13 so that the first adhesive layer side faces the main surface 11a of the first circuit board 11. . At this time, the adhesive film 10 is arranged so that the rubber elastic particle-containing region 1</b>B becomes the first circuit member 13 . Next, a first adhesive film 10 is laminated such 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. A second circuit member 16 is arranged on the circuit member 13 .

Then, as shown in FIG. 3B, the first circuit member 13 and the second circuit member 16 are heated while the first circuit member 13, the adhesive film 10, and the second circuit member 16 are heated. is pressed in the thickness direction, the first circuit member 13 and the second circuit member 16 are thermocompression bonded to each other. At this time, as indicated by arrows in FIG. and hardened by the above heating. As a result, the first electrode 12 and the second electrode 15 are electrically connected to each other through the conductive particles 4, and the first circuit member 13 and the second circuit member 16 are adhered to each other. 2 can be obtained. In the method for manufacturing the circuit connection structure 20 of the present embodiment, since the first adhesive layer may be partially cured by light or the like, the conductive particles 4 are fixed in the first adhesive layer. In addition, the first adhesive layer hardly flows during the thermocompression bonding, and the conductive particles are efficiently captured between the opposing electrodes, so that the opposing first electrode 12 and second electrode The connection resistance between 15 tends to be reduced. Moreover, when the thickness of the first adhesive layer is 5 μm or less, there is a tendency that the conductive particles can be captured more efficiently during circuit connection.

The heating temperature for thermocompression bonding can be appropriately set, and may be, for example, 50 to 190.degree. The pressure is not particularly limited as long as it does not damage the adherend, but in the case of COG mounting, for example, the area conversion pressure at the bump electrode may be 10 to 100 MPa. These heating and pressurizing times may range from 0.5 to 120 seconds. Also, in the case of COP (chip on plastic) mounting, for example, the area conversion pressure at the bump electrode may be 0.1 to 50 MPa.

Hereinafter, the present disclosure will be described more specifically with reference to examples. However, the present disclosure is not limited to these examples.

[Preparation of Conductive Particle-Containing Film (Conductive Particle-Containing Layer), Rubber Elastic Particle-Containing Film (Rubber Elastic Particle-Containing Layer), and Second Adhesive Film (Second Adhesive Layer)]
<Preparation of materials>
Materials shown below were used in the production of these devices.

(A) Conductive Particles A-1: Conductive particles (average particle diameter: 3.0 μm, specific gravity: 2.9 conductive particle)
(B) Rubber elastic particles B-1: EXL-2655 (rubber elastic particles (core-shell type rubber particles), core portion: styrene/butadiene copolymer, shell portion: methyl methacrylate/styrene copolymer, average particle size: 0 .1 μm, Dow Chemical Japan Co., Ltd.)
B-2: KMP-605 (rubber elastic particles (silicone rubber particles, particles obtained by coating the surface of particulate silicone rubber powder with a silicone resin), average particle size: 2 μm, manufactured by Shin-Etsu Chemical Co., Ltd.)
B-3: AC-4030 (Rubber elastic particles (acrylic core-shell type rubber particles), average particle size: 0.5 μm, manufactured by Aica Kogyo Co., Ltd.)
(C) Adhesive Component (C1) Curing Compound (C1C) Cationic Curing Compound C1C-1: OXBP (4,4′-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, bifunctional oxetane compound , manufactured by Ube Industries, Ltd.)
C1C-2: OXSQ (polyfunctional oxetane compound, manufactured by Toagosei Co., Ltd.)
C1C-3: CEL2021P (3′,4′-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, manufactured by Daicel Corporation)
C1C-4: CEL8000 (3,4,3′,4′-diepoxybicyclohexyl, manufactured by Daicel Corporation)
C1C-5: EHPE3150 (1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, manufactured by Daicel Corporation)
C1C-6: YL983U (bisphenol F type liquid epoxy resin, manufactured by Mitsubishi Chemical Corporation)
(C2) Polymerization initiator (C2CH) Thermal cationic polymerization initiator C2CH-1: SI-60LA (manufactured by Sanshin Chemical Industry Co., Ltd.)
(C2CL) Photocationic polymerization initiator C2CL-1: CPI-310B (manufactured by SanAbro Co., Ltd.), diluted with an organic solvent to a non-volatile content of 10% by mass.

(D) Thermoplastic resin D-1: FX-293 (phenoxy resin, manufactured by Nippon Steel Chemical & Materials Co., Ltd.), diluted with an organic solvent to a non-volatile content of 40% by mass D-2: ZX1356-2 (bisphenol Copolymerized phenoxy resin of A type and bisphenol F type, weight average molecular weight: 70000, glass transition temperature: 71 ° C., manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), diluted with an organic solvent to a nonvolatile content of 50% by mass.

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

(F) Component: Filler F-1: SE2050 (silica fine particles, manufactured by Admatechs Co., Ltd.), diluted with an organic solvent to a non-volatile content of 70% by mass F-2: YA-050C (silica fine particles, Co., Ltd. Admatechs), diluted with an organic solvent to 70 mass% non-volatile content

<Production of conductive particle-containing film (conductive particle-containing layer)>
After obtaining a composition obtained by mixing the materials shown in Table 1 at the composition ratio shown in Table 1 (the numerical values in Table 1 mean the non-volatile content), a base material with a thickness of 50 μm was subjected to mold release treatment. A composition layer 1A-a containing each component was obtained by coating on a release-treated PET (polyethylene terephthalate) film while applying a magnetic field and drying the organic solvent. The thickness of the composition layer 1A-a after drying was 3.5 μm. Next, by irradiating the composition layer 1A-a with light (UV irradiation: metal halide lamp, integrated light quantity: 1000 to 2000 mJ/cm ² ), a conductive particle-containing film 1A-a was obtained. The conductive particle-containing film 1A-a contains a cured product of a photocurable resin component.

<Preparation of Rubber Elastic Particle-Containing Film (Rubber Elastic Particle-Containing Layer)>
After mixing the materials shown in Table 2 at the composition ratio shown in Table 2 (the numerical values in Table 2 mean the amount of non-volatile matter), a release-treated substrate having a thickness of 50 μm was released. By coating on a PET (polyethylene terephthalate) film and drying the organic solvent, rubber elastic particle-containing films 1B-a to 1B-f were obtained. The thickness of the rubber elastic particle-containing films 1B-a to 1B-f after drying was 2 μm.

<Preparation of Film Not Containing Rubber Elastic Particles (Layer Not Containing Rubber Elastic Particles)>
Rubber-elastic particle-free films 1B'-a and 1B'-b were prepared for use as comparative examples. After mixing the materials shown in Table 3 at the composition ratio shown in Table 3 (the numerical values in Table 3 mean the non-volatile content), a release-treated substrate having a thickness of 50 μm was released. Films 1B'-a and 1B'-b containing no rubber elastic particles were obtained by coating on a PET (polyethylene terephthalate) film and drying the organic solvent. The thickness of films 1B′-a and 1B′-b not containing rubber elastic particles after drying was 2 μm.

<Production of Second Adhesive Film (Second Adhesive Layer)>
After mixing the materials shown in Table 4 at the composition ratio shown in Table 4 (the numerical values in Table 2 mean the non-volatile content), a release-treated substrate having a thickness of 50 μm was released. A second adhesive film (second adhesive layer) 2-a was obtained by coating on a PET (polyethylene terephthalate) film and drying the organic solvent. The thickness of the second adhesive film 2-a after drying was 8 μm.

(Examples 1 to 6 and Comparative Examples 1 and 2)
[Preparation of adhesive film]
Using the conductive particle-containing film, the rubber elastic particle-containing film (or the rubber elastic particle-free film), and the second adhesive film prepared above, adhesive films having the configurations shown in Table 5 were prepared. First, the conductive particle-containing film and the second adhesive film were laminated together by a hot roll laminator heated to 50°C. Next, the base material (release PET film) of the conductive particle-containing film is peeled off, and the conductive particle-containing film and the rubber elastic particle-containing film (or rubber elastic particle-free film) are laminated using a hot roll laminator heated to 50°C. The adhesives of Examples 1 to 6 and Comparative Examples 1 and 2, in which a film containing rubber elastic particles (or a film not containing rubber elastic particles), a film containing conductive particles, and a second adhesive film were laminated in this order. got the film.

[Evaluation of Adhesive Film]
<Measurement of adhesion before curing>
(Preparation of evaluation sample)
A polyimide substrate (500H, manufactured by DuPont-Toray, thickness: 0.125 mm) was prepared. The adhesive film used was cut into 2.5 mm×30 mm. The adhesive film was placed on the polyimide substrate so that the rubber elastic particle-containing film (or rubber elastic particle-free film) side of the adhesive film was in contact with the polyimide substrate. Using a thermocompression bonding device (BS-17U, manufactured by Ohashi Seisakusho Co., Ltd.) consisting of a stage consisting of a ceramic heater and a tool (8 mm × 50 mm), under the conditions of 60 ° C. and 0.98 MPa (10 kgf / cm ² ). The adhesive film was adhered to the polyimide substrate by applying heat and pressure for 1 second, and the release-treated PET on the side of the adhesive film opposite to the polyimide substrate was peeled off. Next, a polyethylene tape (manufactured by Nitto Denko Corporation, Danpuron No. 335PE, width 2.3 mm) was prepared, and the width of the adhesive film (2. A polyethylene tape was attached so as to be positioned in the center of 5 mm) to prepare an evaluation sample.

(Evaluation of Adhesion)
The polyimide substrate of the prepared evaluation sample is fixed, and the polyethylene tape is peeled off at an angle of 90 ° and a speed of 50 mm / min using a Tensilon universal material tester, and the peel strength is evaluated as the adhesion strength before curing. did. In this evaluation, since the adhesive film is peeled off together with the polyethylene tape, the adhesion between the adhesive film and the polyimide substrate can be measured. When the peel strength was 50 N/m or more, it was evaluated as "A", and when it was less than 50 N/m, it was evaluated as "B". Table 5 shows the results.

<Measurement of adhesive strength after curing>
(Preparation of circuit members)
As a first circuit member, Ti (50 nm)/Al (400 nm)/Ti (50 nm) was applied to the surface of a polyimide substrate (200EN, manufactured by DuPont Toray Co., Ltd., outline: 38 mm × 28 mm, thickness: 0.05 mm). A wiring pattern (pattern width: 19 μm, space between electrodes: 5 μm) was formed. As a second circuit member, an IC chip having a straight arrangement structure in which bump electrodes are arranged in a line (outer shape: 0.9 mm × 20 mm, thickness: 0.3 mm, bump electrode size: 1200 µm ² , space between bump electrodes) : 5 μm, bump electrode thickness: 8 μm).

(Preparation of circuit connection structure)
Using the adhesive films of Examples 1 to 6 and Comparative Examples 1 and 2, circuit connection structures were produced. The adhesive film used was cut into 2.0 mm×25 mm. The adhesive film was placed on the first circuit member such that the rubber-elastic particle-containing film (or rubber-elastic particle-free film) side of the adhesive film was in contact with the first circuit member. Using a thermocompression bonding device (BS-17U, manufactured by Ohashi Seisakusho Co., Ltd.) consisting of a stage consisting of a ceramic heater and a tool (8 mm × 50 mm), under the conditions of 60 ° C. and 0.98 MPa (10 kgf / cm ² ). The adhesive film was adhered to the first circuit member by applying heat and pressure for 1 second, and the release-treated PET on the opposite side of the adhesive film to the first circuit member was peeled off. Next, after aligning the bump electrodes of the first circuit member and the circuit electrodes of the second circuit member, the measured maximum temperature of the adhesive film was 170° C., and the area conversion pressure at the bump electrodes was 20 MPa. The second adhesive layer of the adhesive film was adhered to the second circuit member by applying heat and pressure for 5 seconds to produce a circuit connection structure.

(Evaluation of adhesive force)
The measurement of shear strength as adhesive strength was performed as follows. First, the first circuit member (polyimide substrate) side of the circuit connection structure was fixed to a glass substrate (thickness: 1.0 mm) using a two-liquid adhesive. Next, shear stress was applied using a bonder tester to separate the second circuit member (IC chip) from the circuit connection structure, and the shear strength was measured. A case where the shear strength was 20 MPa or more was evaluated as "A", a case where the shear strength was less than 20 MPa and 10 MPa or more was evaluated as "B", and a case where the shear strength was less than 10 MPa was evaluated as "C". Table 5 shows the results.

As shown in Table 5, the circuit-connecting adhesive films of Examples 1 to 6 were superior to the circuit-connecting adhesive films of Comparative Examples 1 and 2 in terms of adhesion before curing and curing in the circuit-connecting structure. It was excellent in terms of post-shear strength. From these results, it was confirmed that the adhesive film for circuit connection of the present disclosure has excellent adhesion to a plastic substrate before curing, and also has excellent adhesion to a plastic substrate after curing.

Reference Signs List 1 First region 1A Conductive particle-containing region 1B Rubber elastic particle-containing region 2 Second region 4 Conductive particle 5 Rubber elastic particle 10 Circuit connection adhesive film (adhesion agent 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, 18A, 18B, 19... Cured material region, 20... Circuit connection structure.

Claims (6)

a first region containing conductive particles, elastomeric particles, and a first adhesive component;
a second region containing a second adhesive component located adjacent to the first region;
comprising
Adhesive film for circuit connection. The first region includes a conductive particle-containing region containing the conductive particles and a rubber-elastic particle-containing region containing the rubber-elastic particles in this order from the second region side,
The adhesive film for circuit connection according to claim 1. wherein the rubber elastic particle-containing region contains a polyfunctional alicyclic epoxy compound,
The adhesive film for circuit connection according to claim 2. the rubber-elastic particle-containing region further comprises a polyfunctional oxetane compound,
The adhesive film for circuit connection according to claim 3. Between the first circuit member having the first electrode and the second circuit member having the second electrode, the adhesive film for circuit connection according to any one of claims 1 to 4 is interposed. and thermocompression bonding the first circuit member and the second circuit member to electrically connect the first electrode and the second electrode to each other;
A method for manufacturing a circuit connection structure. a first circuit member having a first electrode;
a second circuit member having a second electrode;
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;
with
The circuit connection portion comprises a cured product of the circuit connection adhesive film according to any one of claims 1 to 4,
Circuit connection structure.

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