WO2012169498A1

WO2012169498A1 - Anistropic conductive member

Info

Publication number: WO2012169498A1
Application number: PCT/JP2012/064482
Authority: WO
Inventors: 慎一林
Original assignee: デクセリアルズ株式会社
Priority date: 2011-06-09
Filing date: 2012-06-05
Publication date: 2012-12-13
Also published as: JP2011181525A; KR20140040203A; CN103582919A; TW201313858A; TWI525167B

Abstract

Provided is an anistropic conductive member capable of suppressing the deterioration of an epoxy resin and reducing connection resistance. Conductive particles are dispersed in an insulating adhesive resin containing an epoxy resin, a cationic polymerization initiator, and core-shell polymer particles having a glycidyl group in the shell section. As a result, it is possible to improve the affinity of the epoxy resin with the shell section, minimize the deterioration of the epoxy resin, and reduce connection resistance.

Description

Anisotropic conductive material

The present invention relates to an anisotropic conductive material in which conductive particles are dispersed. This application claims priority on the basis of Japanese Patent Application No. 2011-129294 filed on June 9, 2011 in Japan, and is incorporated herein by reference. Is done.

Conventionally, when connecting liquid crystal panels and tape carrier package (TCP) substrates, liquid crystal panels and chip-on-film (COF) substrates, printed wiring boards (PWB) and TCP substrates, PWB and COF substrates, anisotropic conductive films (ACF) is used.

An anisotropic conductive film is a resin composition containing an epoxy resin, a polymerization initiator, conductive particles, etc., formed into a film, and is classified into an anionic polymerization type, a cationic polymerization type, etc., depending on the polymerization method for the epoxy resin. Is done.

As one method for improving the adhesive strength of an anisotropic conductive film, a method of adding so-called core-shell polymer particles, which are rubber-like polymer particles, to an anisotropic conductive film is known (for example, Patent Documents). 1 and 2). By adding the core-shell polymer particles, a cured product having high toughness can be obtained, and a cured product having excellent heat resistance and insulation can be obtained.

JP 2008-195852 A JP 2010-001346 A

The curing mechanism by cationic polymerization is presumed that a cationic species or Lewis acid generated from an initiator by an external stimulus such as heat or light opens the epoxy group and polymerizes all at once by a chain reaction to form a network. . As a result, all the cross-linked parts are ether bonds, and since there are no ester bonds weak to water and free hydroxyl groups, it can be expected that excellent electrical characteristics, water resistance, solvent resistance, and the like can be obtained.

However, when the conventional core-shell polymer particles are added to the cationic polymerization type anisotropic conductive film, the affinity between the shell portion and the epoxy resin is insufficient, which causes deterioration of the epoxy resin and high connection resistance. There was a case.

The present invention has been proposed in view of such a conventional situation, and provides an anisotropic conductive material that can suppress deterioration of an epoxy resin and reduce connection resistance.

In order to solve the above-described problems, the anisotropic conductive material according to the present invention is conductive to an insulating adhesive resin containing an epoxy resin, a cationic polymerization initiator, and core-shell polymer particles having a glycidyl group in the shell portion. The characteristic particle is dispersed.

Further, the connection body according to the present invention is an anisotropic conductive material in which conductive particles are dispersed in an insulating adhesive resin containing an epoxy resin, a cationic polymerization initiator, and a core-shell polymer particle having a glycidyl group in a shell portion. The electrode of the first electronic component and the electrode of the second electronic component are electrically connected depending on the material.

According to the present invention, the affinity between the shell portion and the epoxy resin is improved, the deterioration of the epoxy resin is suppressed, and the connection resistance can be reduced.

Hereinafter, embodiments of the present invention will be described in detail in the following order.
1. 1. Anisotropic conductive material 2. Manufacturing method of anisotropic conductive material 3. Connection method using anisotropic conductive material Example

<1. Anisotropic Conductive Material>
The anisotropic conductive material in the present embodiment is obtained by dispersing conductive particles in an insulating adhesive resin containing an epoxy resin, a cationic polymerization initiator, and core-shell polymer particles having a glycidyl group in the shell portion. is there.

As the epoxy resin, bisphenol type epoxy resin, phenol novolac type epoxy resin, alicyclic type epoxy resin, heterocyclic type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, halogenated epoxy resin, etc. can be used alone or in combination. Can be used. The content of the epoxy resin is preferably 35 to 95% by mass, more preferably 45%, based on the entire insulating adhesive resin (excluding conductive particles, epoxy resin, cationic polymerization initiator, core-shell polymer particles, etc.). Is 75% by mass.

Also, in order to improve the film formability, it is preferable to mix a phenoxy resin which is a high molecular weight epoxy resin made from epichlorohydrin and bisphenol. If the content of the phenoxy resin is too small, a film is not formed. If the content is too large, the exclusion property of the resin for obtaining electrical connection tends to be low. It is preferably 25 to 45% by mass.

In the cationic curing agent, the cationic species causes the epoxy group at the end of the epoxy resin to open and self-crosslinks the epoxy resins. Examples of such cationic curing agents include onium salts such as aromatic sulfonium salts, aromatic diazonium salts, iodonium salts, phosphonium salts, and selenonium salts. In particular, an aromatic sulfonium salt is suitable as a cationic curing agent because of its excellent reactivity at low temperatures and a long pot life.

The core-shell polymer particles are composed of a core part and a shell part that forms an outer layer of the core part. The core portion is not particularly limited as long as it does not inhibit polymerization for introducing a glycidyl group into the shell portion. For example, an acrylic rubber polymer, a diene rubber polymer, an olefin rubber polymer, etc. Or a mixture of two or more.

The core portion preferably has a theoretical glass transition temperature represented by the following formula (1) (FOX formula) of −30 ° C. or lower. When the theoretical glass transition temperature exceeds −30 ° C., it becomes difficult to obtain good adhesive strength of the cured product.
1 / Tg = W ₁ / T ₁ + W ₂ / T ₂ +... W _n / T _n (1)
In _{_{_{(1), W 1, W 2 ··· W}}} n is the weight fraction of each _{_{_{monomer, T 1, T 2 ··· T}}} n is the glass transition temperature of each monomer (K).

Specific examples of the monomer forming the core include, for example, ethyl acrylate (Tg = −22 ° C., only temperature is shown in parentheses below), n-propyl acrylate (−37 ° C.), n-butyl acrylate (− 54 ° C.), isobutyl acrylate (−24 ° C.), sec-butyl acrylate (−21 ° C.), n-hexyl acrylate (−57 ° C.), 2-ethylhexyl acrylate (−85 ° C.), n-octylyl methacrylate (−25 ° C), alkyl (meth) acrylates such as isooctyl acrylate (-45 ° C), n-nonyl methacrylate (-35 ° C), n-decyl methacrylate (-45 ° C): 4 to 6 carbon atoms such as butadiene Conjugated diene monomers composed of carbon atoms: vinyl methyl ether (-31 ° C), vinyl ethyl ether -33 ° C.), include vinyl ethers such as vinyl propyl ether (-49 ° C.) is. These monomers may be used alone or in combination of two or more, but (meth) acrylate monomers are preferably used from the viewpoints of adjustment of glass transition temperature, adhesiveness, economy and the like.

The shell part has a glycidyl group introduced by polymerization with the core part. For example, when the core portion is composed of an acrylic rubber polymer, glycidyl methacrylate, β-methyl glycidyl methacrylate, glycidyl acrylate, or the like can be used as a polymerization monomer for forming a shell portion having a glycidyl group.

The core-shell polymer particles preferably have an epoxy value of the shell portion of 0.2 eq / kg or more. When the epoxy value is less than 0.2 eq / kg, it is difficult to obtain a good connection resistance as an anisotropic conductive material.

Here, the epoxy value of the shell part is the ratio of the monomer having an epoxy group contained in the polymerizable monomer composition forming the shell part. For example, if 1% of glycidyl (meth) acrylate (GMA) is contained in the polymerizable monomer composition, 0.01 / 142 (GMA molecular weight) = 0.00007 [mol / g], which is replaced with an equivalent unit. And 0.07 [eq / kg].

The content of the core-shell polymer particles is preferably 20 to 50% by mass with respect to the entire insulating adhesive resin. When the content of the core-shell polymer particles is less than 20% by mass, good adhesive strength of the cured product cannot be obtained. On the other hand, when the content of the core-shell polymer particles exceeds 50% by mass, it becomes difficult to obtain good connection resistance as a tangentially anisotropic conductive material.

Moreover, it is preferable to add a silane coupling agent as another additive composition of the insulating adhesive resin. As the silane coupling agent, an epoxy-based, amino-based, mercapto-sulfide-based, ureido-based, or the like can be used. In this embodiment, an epoxy-based silane coupling agent is preferably used. Thereby, the adhesiveness in the interface of an organic material and an inorganic material can be improved. Moreover, you may add an inorganic filler. As the inorganic filler, silica, talc, titanium oxide, calcium carbonate, magnesium oxide and the like can be used, and the kind of the inorganic filler is not particularly limited. Depending on the content of the inorganic filler, the fluidity can be controlled and the particle capture rate can be improved. Moreover, when mix | blending each component of these binder resin, toluene, ethyl acetate, or these mixed solvents are used preferably.

Examples of the conductive particles include metal particles such as gold particles, silver particles, and nickel particles, and metal-coated resin particles in which the surfaces of resin particles such as benzoguanamine resin and styrene resin are coated with a metal such as gold, nickel, and zinc. Can be used. The average particle size of such conductive particles is 1 to 10 μm, more preferably 2 to 6 μm.

The average particle density of the conductive particles in the insulating adhesive resin is connected in terms of reliability and insulation reliability, is preferably 1000 to 50000 / mm ^2, more preferably from 3,000 to 30,000 pieces / mm ² .

The anisotropic conductive material having such a structure improves the affinity between the shell portion of the core-shell polymer particles and the epoxy resin, so that the deterioration of the epoxy resin is suppressed and the connection resistance can be reduced. Moreover, the toughness of the epoxy resin is enhanced by the core-shell polymer particles, and an excellent adhesive strength can be obtained.

<2. Method for producing anisotropic conductive material>
Next, the manufacturing method of the anisotropic conductive material mentioned above is demonstrated. Here, a method for manufacturing an anisotropic conductive film in which an anisotropic conductive material is formed in a film shape will be described. The method for producing an anisotropic conductive film includes a particle preparation step of preparing a core-shell polymer particle having a glycidyl group in a shell portion, an epoxy resin, a cationic polymerization initiator, a core-shell polymer particle, a conductive material on a release substrate. An application step of applying a composition containing conductive particles, and a drying step of drying the composition on the release substrate.

In the particle preparation step, first, a solution containing a polymerization initiator is heated and stirred, and a monomer (single or a combination of two or more) is dropped to obtain core particles (core part) as a polymer. Then, a mixed solution of a polymerizable monomer composition and a chain transfer agent that forms a shell part having a glycidyl group is dropped into the solution in which the core particles are obtained, and the mixture is stirred and cooled to prepare an emulsion of the core-shell polymer particles. To obtain core-shell polymer particles.

In the coating step, a bar coater, a coating device, etc. are prepared after adjusting a composition containing an epoxy resin, a cationic polymerization initiator, core-shell polymer particles, and conductive particles on the release substrate to have the above-described configuration. Apply using. The release substrate has, for example, a laminated structure in which a release agent such as silicone is applied to PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methlpentene-1), PTFE (Polytetrafluoroethylene), etc. Prevents the composition from drying and maintains the shape of the composition. The composition is obtained by dissolving the above-described composition in an organic solvent. As the organic solvent, toluene, ethyl acetate, a mixed solvent thereof, or other various organic solvents can be used.

In the next drying step, the composition on the release substrate is dried by a heat oven, a heat drying apparatus or the like. Thereby, an anisotropic conductive film in which conductive particles are dispersed in an insulating adhesive resin containing an epoxy resin, a cationic polymerization initiator, and core-shell polymer particles can be obtained.

<3. Connection Method Using Anisotropic Conductive Material>
Next, the electronic component connecting method using the anisotropic conductive material described above is different in that conductive particles are dispersed in an insulating adhesive resin containing an epoxy resin, a cationic polymerization initiator, and core-shell polymer particles. The isotropic conductive material is sandwiched between the electrode of the first electronic component and the electrode of the second electronic component, the first electronic component and the second electronic component are heated and pressurized, and the first electronic component The electrode is electrically connected to the electrode of the second electronic component. In addition, since the anisotropic conductive material in this implementation is a cation curable type, you may use an ultraviolet-ray and a heating each independently, or may use both together.

Although the anisotropic conductive material in this embodiment can be used in various situations, the first electronic component is a liquid crystal panel, a printed wiring board (PWB), or the like, and the second electronic component is It is preferably applied to a flexible printed circuit board, a tape carrier package (TCP) board, a chip-on-film (COF) board, or the like.

In the anisotropic conductive material in the present embodiment, since the core-shell polymer particles having a glycidyl group are added to the shell portion, deterioration of the epoxy resin of the anisotropic conductive material is suppressed. For this reason, the connection body in which the electrode of the first electronic component and the electrode of the second electronic component are electrically connected can obtain a stable connection resistance even in a high temperature and high humidity reliability test. In addition, since the toughness of the epoxy resin is reinforced by the core-shell polymer particles, this connection body can obtain excellent adhesive strength.

<2. Example>
Hereinafter, the present invention will be specifically described with reference to examples. Here, first, a plurality of core particles A to F having different theoretical glass transition temperatures are prepared, and a plurality of core shell polymer particles (samples 1 to 12) having different epoxy values are prepared using the core particles A to F. Anisotropic conductive materials of Examples and Comparative Examples using core-shell polymer particles were produced. And the connection body was produced using the anisotropic conductive material of an Example and a comparative example, and the connection resistance and adhesive strength of the connection body were evaluated. The present invention is not limited to these examples.

<Preparation of core particles>
[Core particle A]
A 1 liter round bottom Kolben was charged with 400 parts by mass of pure water and 0.02 parts by mass of sodium dodecylbenzenesulfonate and heated to 80 ° C. with stirring. Next, using 0.3 parts by mass of potassium persulfate as an initiator, as a polymerizable monomer composition for forming the core part, a solution containing 10% by mass of butyl acrylate and 90% by mass of 2-ethylhexyl acrylate was added for 100 minutes. Then, the mixture was further stirred for 30 minutes after the completion of the dropwise addition to obtain core particles A.

The theoretical glass transition temperature (Tg) of the core particle A was calculated by the following formula (1) (FOX formula), which was −82 ° C.
1 / Tg = W ₁ / T ₁ + W ₂ / T ₂ +... W _n / T _n (1)
In _{_{_{(1), W 1, W 2 ··· W}}} n is the weight fraction of each _{_{_{monomer, T 1, T 2 ··· T}}} n is the glass transition temperature of each monomer (K).

[Core particle B]
A core particle B was obtained in the same manner as the preparation method of the core particle A, except that a solution containing 90% by mass of butyl acrylate and 10% by mass of ethyl acrylate was used as the polymerizable monomer composition forming the core part. . The theoretical glass transition temperature (Tg) of the core particle B was −51.2 ° C. when calculated by the FOX equation.

[Core particle C]
A core particle C was obtained in the same manner as the preparation method of the core particle A, except that a solution containing 30% by mass of butyl acrylate and 70% by mass of ethyl acrylate was used as the polymerizable monomer composition forming the core part. . The theoretical glass transition temperature (Tg) of the core particle C was calculated by the FOX equation and found to be −32.5 ° C.

[Core particle D]
A core particle D was obtained in the same manner as the preparation method of the core particle A except that a solution containing 100% by mass of ethyl acrylate was used as the polymerizable monomer composition forming the core part. The theoretical glass transition temperature (Tg) of the core particle D was calculated by the FOX equation and found to be −22.0 ° C.

[Core particle E]
A core particle E was obtained in the same manner as the preparation method of the core particle A, except that a solution containing 80% by mass of ethyl acrylate and 20% by mass of methyl methacrylate was used as the polymerizable monomer composition forming the core part. . The theoretical glass transition temperature (Tg) of the core particle E was calculated by the FOX equation and found to be −3.9 ° C.

[Core particle F]
A core particle F was obtained in the same manner as the preparation method of the core particle A, except that a solution containing 60% by mass of ethyl acrylate and 40% by mass of methyl methacrylate was used as the polymerizable monomer composition forming the core part. . It was 17.0 degreeC when the theoretical glass transition temperature (Tg) of this core particle F was computed by FOX type | formula.

Table 1 shows the composition of the core particles A to F and the theoretical glass transition temperature (Tg). Further, the average particle diameters of the core particles A to F were measured and all were 0.15 μm. Moreover, the variation coefficient of the particle diameter was 6%, and it was confirmed that the distribution of the particle diameter was very small.

<Preparation of core-shell polymer particles>
[Sample 1]
After stirring the solution from which the core particle B was obtained, 0.2 parts by mass of octyl thioglycolate as a chain transfer agent was added to a solution containing 100% by mass of methyl methacrylate as a polymerizable monomer composition forming the shell part. The mixed liquid was added dropwise over 100 minutes. After dropping, the mixture was further stirred for 2 hours and then cooled to prepare an emulsion of core-shell polymer particles, whereby core-shell polymer particles of Sample 1 were obtained.

[Sample 2]
As the polymerizable monomer composition for forming the shell portion, the same procedure as in the core-shell polymer particle preparation method of Sample 1 was used, except that a solution containing 98.6% by mass of methyl methacrylate and 1.4% by mass of glycidyl methacrylate was used. Thus, core-shell polymer particles of Sample 2 were obtained. The epoxy value of the shell part was the ratio of the monomer having an epoxy group contained in the polymerizable monomer composition forming the shell part, and the glycidyl group was introduced into the shell part at the same ratio. In sample 2, since 1.4% by mass of glycidyl (meth) acrylate (GMA) is contained in the polymerizable monomer composition, 0.014 / 142 (GMA molecular weight) = 0.0001 [mol / g], equivalent unit Is 0.1 [eq / kg].

[Sample 3]
As the polymerizable monomer composition for forming the shell part, the same procedure as in the core-shell polymer particle preparation method of Sample 1 was used, except that a solution containing 97.1% by mass of methyl methacrylate and 2.9% by mass of glycidyl methacrylate was used. Thus, core-shell polymer particles of Sample 3 were obtained. The epoxy value of the core-shell polymer particle shell portion of Sample 3 was 0.2 [eq / kg] when calculated as the ratio of GMA contained in the polymerizable monomer composition forming the shell portion.

[Sample 4]
As the polymerizable monomer composition for forming the shell part, the same method as the core-shell polymer particle preparation method of Sample 1 was used except that a solution containing 95.7% by mass of methyl methacrylate and 4.3% by mass of glycidyl methacrylate was used. Thus, core-shell polymer particles of Sample 4 were obtained. The epoxy value of the shell part of the core-shell polymer particles of Sample 4 was 0.3 [eq / kg] when calculated as the ratio of GMA contained in the polymerizable monomer composition forming the shell part.

[Sample 5]
As the polymerizable monomer composition for forming the shell portion, the same method as the core-shell polymer particle preparation method of Sample 1 was used except that a solution containing 91.4% by mass of methyl methacrylate and 8.6% by mass of glycidyl methacrylate was used. Thus, core-shell polymer particles of Sample 5 were obtained. The epoxy value of the shell part of the core-shell polymer particles of Sample 5 was 0.6 [eq / kg] when calculated as the ratio of GMA contained in the polymerizable monomer composition forming the shell part.

[Sample 6]
As the polymerizable monomer composition for forming the shell part, the same procedure as for the core-shell polymer particles of Sample 1 was used, except that a solution containing 85.7% by mass of methyl methacrylate and 14.3% by mass of glycidyl methacrylate was used. Thus, core-shell polymer particles of Sample 6 were obtained. The epoxy value of the shell part of the core-shell polymer particles of Sample 6 was 1.0 [eq / kg] when calculated as the ratio of GMA contained in the polymerizable monomer composition forming the shell part.

[Sample 7]
A core-shell polymer particle of Sample 7 was obtained in the same manner as the preparation method of the core-shell polymer particle of Sample 1, except that a solution containing 100% by mass of glycidyl methacrylate was used as the polymerizable monomer composition forming the shell portion. The epoxy value of the shell part of the core-shell polymer particles of Sample 7 was 7.0 [eq / kg] when calculated as the ratio of GMA contained in the polymerizable monomer composition forming the shell part.

[Sample 8]
A sample was used except that a solution containing 91.4% by mass of methyl methacrylate and 8.6% by mass of glycidyl methacrylate was used as the polymerizable monomer composition forming the shell portion using the solution from which the core particles A were obtained. The core-shell polymer particles of Sample 8 were obtained in the same manner as in the production method of the core-shell polymer particles of 1. The epoxy value of the shell part of the core-shell polymer particles of Sample 8 was 0.6 [eq / kg] when calculated as the ratio of GMA contained in the polymerizable monomer composition forming the shell part.

[Sample 9]
A sample was used except that a solution containing 91.4% by mass of methyl methacrylate and 8.6% by mass of glycidyl methacrylate was used as the polymerizable monomer composition forming the shell portion using the solution from which the core particles C were obtained. The core-shell polymer particles of Sample 9 were obtained in the same manner as in the production method of the core-shell polymer particles of 1. The epoxy value of the shell part of the core-shell polymer particles of Sample 9 was 0.6 [eq / kg] when calculated as the ratio of GMA contained in the polymerizable monomer composition forming the shell part.

[Sample 10]
A sample was used except that a solution containing 91.4% by mass of methyl methacrylate and 8.6% by mass of glycidyl methacrylate was used as a polymerizable monomer composition for forming a shell portion using the solution from which the core particle D was obtained. The core-shell polymer particles of Sample 10 were obtained in the same manner as in the production method of the core-shell polymer particles of 1. The epoxy value of the shell part of the core-shell polymer particles of Sample 10 was 0.6 [eq / kg] when calculated as the ratio of GMA contained in the polymerizable monomer composition forming the shell part.

[Sample 11]
A sample was used except that a solution containing 91.4% by weight of methyl methacrylate and 8.6% by weight of glycidyl methacrylate was used as a polymerizable monomer composition for forming a shell portion using the solution from which the core particle E was obtained. The core-shell polymer particles of Sample 11 were obtained in the same manner as in the method for producing the core-shell polymer particles of 1. The epoxy value of the shell part of the core-shell polymer particles of Sample 11 was 0.6 [eq / kg] when calculated as the ratio of GMA contained in the polymerizable monomer composition forming the shell part.

[Sample 12]
A sample was used except that a solution containing 91.4% by mass of methyl methacrylate and 8.6% by mass of glycidyl methacrylate was used as a polymerizable monomer composition for forming a shell portion using the solution from which the core particles F were obtained. The core-shell polymer particles of Sample 12 were obtained in the same manner as in the production method of the core-shell polymer particles of 1. The epoxy value of the shell part of the core-shell polymer particles of Sample 12 was 0.6 [eq / kg] when calculated as the ratio of GMA contained in the polymerizable monomer composition forming the shell part.

Table 2 shows the composition and epoxy value of the core-shell particles of Samples 1 to 12. The final particle diameters of the core-shell polymer particles of Samples 1 to 12 were all 0.19 μm and the coefficient of variation was 6%.

<Preparation of anisotropic conductive material, connection body, measurement of connection resistance, and measurement of adhesive strength>
[Example 1]
35 parts by mass of phenoxy resin (product name: YP-50, manufactured by Nippon Steel Chemical Co., Ltd.), 30 parts by mass of epoxy resin (product name: EP-828, manufactured by Mitsubishi Chemical Corporation), 30 parts by mass of core-shell polymer particles of sample 2, silane cup Conductive particles in an adhesive composed of 1 part by mass of a ring agent (product name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) and 4 parts by mass of a curing agent (product name: SI-60L, manufactured by Sanshin Chemical Co., Ltd.) (Product name: AUL704, manufactured by Sekisui Chemical Co., Ltd.) was dispersed so as to have a particle density of 10,000 particles / mm ² to prepare a cation-curing electrode bonding sheet of Example 1 having a thickness of 20 μm.

[Production of connected body]
As an evaluation substrate, COF (50 μm P, Cu 8 μmt-Sn plating, 38 μmt-Sperflex substrate) and IZO coating glass (all surface IZO coating, glass thickness 0.7 mm) were bonded. The cation-curing electrode bonding sheet was slit to 1.5 mm width and attached to IZO coating glass. After COF was temporarily fixed thereon, bonding was performed using a heat tool of 1.5 mm width and a buffer material of 100 μmt Teflon under bonding conditions of 190 ° C.-3 MPa-5 sec to complete a connection body.

[Measurement of connection resistance]
The connection resistance of the connection body after the initial stage and after the reliability test of 85 ° C./85%/500 hr was measured. The measurement was performed by measuring the connection resistance when a current of 1 mA was passed by a four-terminal method using a digital multimeter (product number: digital multimeter 7555, manufactured by Yokogawa Electric Corporation). As a result, the initial connection resistance of the connection body connected using the anisotropic conductive material of Example 1 was 2.1Ω, and the connection resistance after the reliability test was 5.5Ω.

[Measurement of adhesive strength of connector]
The adhesive strength after the reliability test of the initial stage and 85 ° C./85%/500 hr was measured for each mounted body. The measurement was performed by measuring the adhesive strength when the COF was pulled up at a measurement speed of 50 mm / sec using a tensile tester (product number: RTC1201, manufactured by AND). As a result, the initial bonding strength of the connection body connected using the anisotropic conductive material of Example 1 was 7.0 N / cm, and the bonding strength after the reliability test was 4.3 N / cm.

[Example 2]
A cation-curing electrode bonding sheet of Example 2 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 3 were used. The initial connection resistance of the connection body connected using the anisotropic conductive material of Example 2 was 2.0Ω, and the connection resistance after the reliability test was 4.3Ω. Further, the initial adhesive strength of the connection body was 7.1 N / cm, and the adhesive strength after the reliability test was 5.0 N / cm.

[Example 3]
A cation-curing electrode bonding sheet of Example 3 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 4 were used. The initial connection resistance of the connection body connected using the anisotropic conductive material of Example 3 was 2.1Ω, and the connection resistance after the reliability test was 4.0Ω. Further, the initial adhesive strength of the connection body was 7.0 N / cm, and the adhesive strength after the reliability test was 5.5 N / cm.

[Example 4]
A cation-curing electrode bonding sheet of Example 4 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 5 were used. The connection resistance of the connection body connected using the anisotropic conductive material of Example 4 was 2.1Ω, and the connection resistance after the reliability test was 3.7Ω. The initial bond strength of the connection body was 7.3 N / cm, and the bond strength after the reliability test was 6.2 N / cm.

[Example 5]
A cation-curing electrode bonding sheet of Example 5 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 6 were used. The initial connection resistance of the connection body connected using the anisotropic conductive material of Example 5 was 2.0Ω, and the connection resistance after the reliability test was 4.1Ω. Further, the initial adhesive strength of the connection body was 7.0 N / cm, and the adhesive strength after the reliability test was 6.0 N / cm.

[Example 6]
A cation-curing electrode bonding sheet of Example 6 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 7 were used. The initial connection resistance of the connection body connected using the anisotropic conductive material of Example 6 was 2.1Ω, and the connection resistance after the reliability test was 3.8Ω. Further, the initial adhesive strength of the connection body was 7.1 N / cm, and the adhesive strength after the reliability test was 6.0 N / cm.

[Example 7]
A cation-curing electrode bonding sheet of Example 7 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 8 were used. The initial connection resistance of the connection body connected using the anisotropic conductive material of Example 7 was 2.0Ω, and the connection resistance after the reliability test was 4.0Ω. The initial bond strength of the connection body was 7.5 N / cm, and the bond strength after the reliability test was 6.2 N / cm.

[Example 8]
A cationically cured electrode bonding sheet of Example 8 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 9 were used. The initial connection resistance of the connection body connected using the anisotropic conductive material of Example 8 was 2.1Ω, and the connection resistance after the reliability test was 3.8Ω. The initial bond strength of the connection body was 6.9 N / cm, and the bond strength after the reliability test was 5.1 N / cm.

[Example 9]
A cationically cured electrode bonding sheet of Example 9 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 10 were used. The connection resistance of the connection body connected using the anisotropic conductive material of Example 9 was 2.0Ω, and the connection resistance after the reliability test was 3.7Ω. The initial bond strength of the connection body was 6.9 N / cm, and the bond strength after the reliability test was 4.7 N / cm.

[Example 10]
A cation-curing electrode bonding sheet of Example 10 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 11 were used. The initial connection resistance of the connection body connected using the anisotropic conductive material of Example 10 was 2.1Ω, and the connection resistance after the reliability test was 3.8Ω. Further, the initial adhesive strength of the connection body was 6.0 N / cm, and the adhesive strength after the reliability test was 4.5 N / cm.

[Example 11]
A cation-curing electrode bonding sheet of Example 11 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 12 were used. The initial connection resistance of the connection body connected using the anisotropic conductive material of Example 11 was 2.1Ω, and the connection resistance after the reliability test was 3.7Ω. Further, the initial adhesive strength of the connection body was 5.5 N / cm, and the adhesive strength after the reliability test was 3.0 N / cm.

[Example 12]
The cation-curing electrode adhesive sheet of Example 12 was prepared in the same manner as in Example 1 except that 50 parts by mass of phenoxy resin, 35 parts by mass of epoxy resin, and 10 parts by mass of the core-shell polymer particles of Sample 5 were used. Produced. The connection resistance of the connection body connected using the anisotropic conductive material of Example 12 was 2.0Ω, and the connection resistance after the reliability test was 3.4Ω.
Further, the initial adhesive strength of the connection body was 6.0 N / cm, and the adhesive strength after the reliability test was 4.0 N / cm.

[Example 13]
Except for using 45 parts by mass of the phenoxy resin, 30 parts by mass of the epoxy resin, and 20 parts by mass of the core-shell polymer particles of Sample 5, the cation-curing electrode adhesive sheet of Example 13 was used in the same manner as in Example 1. Produced. The initial connection resistance of the connection body connected using the anisotropic conductive material of Example 13 was 2.2Ω, and the connection resistance after the reliability test was 3.6Ω.
Further, the initial adhesive strength of the connection body was 6.9 N / cm, and the adhesive strength after the reliability test was 5.0 N / cm.

[Example 14]
The cation-curing electrode adhesive sheet of Example 14 was prepared in the same manner as in Example 1 except that 25 parts by mass of phenoxy resin, 20 parts by mass of epoxy resin, and 50 parts by mass of the core-shell polymer particles of Sample 5 were used. Produced. The connection resistance of the connection body connected using the anisotropic conductive material of Example 14 was 2.1Ω, and the connection resistance after the reliability test was 4.4Ω.
The initial bond strength of the connection body was 7.5 N / cm, and the bond strength after the reliability test was 6.2 N / cm.

[Example 15]
The cation-curing electrode bonding sheet of Example 15 was prepared in the same manner as in Example 1 except that 15 parts by mass of phenoxy resin, 20 parts by mass of epoxy resin, and 60 parts by mass of the core-shell polymer particles of Sample 5 were used. Produced. The connection resistance of the connection body connected using the anisotropic conductive material of Example 15 was 2.0Ω, and the connection resistance after the reliability test was 4.7Ω.
Further, the initial adhesive strength of the connection body was 7.5 N / cm, and the adhesive strength after the reliability test was 6.3 N / cm.

[Comparative Example 1]
A cationically curable electrode bonding sheet of Comparative Example 1 in the same manner as in Example 1 except that the core-shell polymer particles were not used (0 part by mass), the phenoxy resin was changed to 60 parts by mass, and the epoxy resin was changed to 35 parts by mass. Was made. The initial connection resistance of the connection body connected using the anisotropic conductive material of Comparative Example 1 was 2.0Ω, and the connection resistance after the reliability test was 3.3Ω. Further, the initial adhesive strength of the connection body was 5.1 N / cm, and the adhesive strength after the reliability test was 0.7 N / cm.

[Comparative Example 2]
A cation-curing electrode bonding sheet of Comparative Example 2 was produced in the same manner as in Example 1 except that the core-shell polymer particles of Sample 1 were used. The initial connection resistance of the connection body connected using the anisotropic conductive material of Comparative Example 1 was 2.1Ω, and the connection resistance after the reliability test was 7.0Ω. Further, the initial adhesive strength of the connection body was 7.2 N / cm, and the adhesive strength after the reliability test was 4.0 N / cm.

Table 3 shows the blending amount of the core-shell polymer particles, the epoxy value, the theoretical glass transition temperature, the connection resistance of the connection body, and the adhesive strength in the cation-curing electrode bonding sheets of the above Examples and Comparative Examples.

<Evaluation>
Examples 1 to 15 containing core-shell polymer particles having a glycidyl group in the shell part can obtain excellent adhesive strength after the initial stage and reliability test of the connected body, as compared with Comparative Example 1 containing no core-shell polymer particles. I was able to.

In addition, Examples 1 to 15 containing core-shell polymer particles having a glycidyl group in the shell part were compared with Comparative Example 2 containing core-shell polymer particles having no glycidyl group in the shell part, and the initial and reliability tests of the connected body. Later, excellent connection resistance could be obtained.
This is presumably because the affinity between the shell portion and the epoxy resin was improved and the deterioration of the epoxy resin was suppressed.

Further, as in Examples 2 to 6, when the epoxy value of the shell portion of the core-shell polymer particles was 0.2 eq / kg or more, stable connection resistance could be obtained even after the reliability test.

Further, as in Examples 4 and 7 and 8, when the theoretical glass transition temperature of the core part of the core-shell polymer particles is −30 ° C. or lower, stable adhesive strength can be obtained even after the reliability test. did it.

Further, as in Examples 4 and 13 and 14, the core-shell polymer particles are contained in the insulating adhesive resin in an amount of 20 to 50% by mass, so that stable connection resistance and adhesive strength can be obtained even after the reliability test. I was able to get it.

Claims

An anisotropic conductive material in which conductive particles are dispersed in an insulating adhesive resin containing an epoxy resin, a cationic polymerization initiator, and core-shell polymer particles having a glycidyl group in the shell portion.
The anisotropic conductive material according to claim 1, wherein the core-shell polymer particles have a core portion made of an acrylic rubber polymer, and the shell portion has a glycidyl group derived from glycidyl (meth) acrylate.
The anisotropic conductive material according to claim 1 or 2, wherein an epoxy value of a shell portion of the core-shell polymer particle is 0.2 eq / kg or more.
The anisotropic conductive material according to any one of claims 1 to 3, wherein a theoretical glass transition temperature of a core portion of the core-shell polymer particle is -30 ° C or lower.
The anisotropic conductive material according to any one of claims 1 to 4, wherein the core-shell polymer particles are contained in an insulating adhesive resin in an amount of 20 to 50 mass%.
The electrode of the first electronic component is made of an anisotropic conductive material in which conductive particles are dispersed in an insulating adhesive resin containing an epoxy resin, a cationic polymerization initiator, and core-shell polymer particles having a glycidyl group in the shell portion. And a connection body in which the electrode of the second electronic component is electrically connected.