KR101163436B1 - Insulation-coated electroconductive particles - Google Patents

Abstract

(Problem) Excellent solvent resistance and conduction reliability are simultaneously given to the insulating coating electrically-conductive particle for anisotropic conductive adhesive agents.

(Solution means) The polyfunctional compound which has the other functional group which can react the said insulating resin layer of the insulating-coated electrically conductive particle which the surface of electroconductive particle is coat | covered with the insulating resin layer which consists of insulating resin which has a functional group, and the functional group of insulating resin. Surface treatment with. When the functional group of insulating resin is a carboxyl group, it is preferable to use a polyfunctional aziridine compound as a polyfunctional compound, For example, trimethylolpropane- tri- (beta)-aziridinyl propionate, tetramethylol methane-tri -beta -aziridinyl propionate or N, N-hexamethylene-1,6-bis-1-aziridinecarboxyamide. The insulating resin layer is composed of an insulating resin having an acrylic acid monomer unit or a methacrylic acid monomer unit, preferably an acrylic acid styrene copolymer.

Clad conductive particles

Description

Insulation coating conductive particle {INSULATION-COATED ELECTROCONDUCTIVE PARTICLES}

The present invention relates to insulating coated conductive particles used in anisotropic conductive adhesives.

As the conductive particles used for the anisotropic conductive adhesive, thermoplastic insulating resins are used to prevent the occurrence of shorts between the conductive particles in the surface of the conductive particles such as metal particles such as nickel and plated metal particles having a plating metal layer formed on the surface of the resin particles. Or insulating coating electroconductive particle coat | covered with insulating thermosetting resin is used widely (refer patent document 1-3).

Patent Document 1: Japanese Patent Application Laid-Open No. 5-217617

Patent Document 2: Japanese Patent Application Laid-Open No. 5-70750

Patent Document 3: Japanese Patent Application Laid-Open No. 11-241054

DISCLOSURE OF INVENTION

Problems to be solved by the invention

However, if an anisotropic conductive adhesive film or paste is produced using the insulating coated conductive particles as described above, the insulating resin layer covering the insulating coated conductive particles may be used as a solvent for use in the manufacture. There was a problem of swelling, dissolution or deformation. In such a case, adverse effects also occurred in the conduction reliability of the anisotropic conductive adhesive.

In order to improve the solvent resistance of the insulating resin layer, it is also conceivable to configure the insulating resin layer with a thermosetting insulating resin composition, but if the insulating resin layer becomes too hard, the connection insulating resin layer is sufficiently removed from the opposite electrodes to be connected. As a result, there is a problem that sufficient conduction reliability cannot be obtained as a result.

An object of this invention is to make it possible to simultaneously provide the outstanding solvent resistance and conduction | relief reliability to the insulation coating conductive particle suitable for the electrically-conductive particle of an anisotropic conductive adhesive agent.

Means for solving the problem

MEANS TO SOLVE THE PROBLEM This inventor forms the insulating resin layer which consists of insulating resin which has a functional group on the surface of an electroconductive particle, and surface-treats this insulating resin layer with the polyfunctional compound which has 2 or more of other functional groups which react with this functional group in 1 molecule. When the functional group of an insulating resin layer and the functional group of a polyfunctional compound were made to react, it discovered that the solvent resistance and conduction | reliability of the insulation coating electroconductive particle obtained can be improved, and this invention was completed.

That is, this invention is insulation coating electroconductive particle in which the surface of electroconductive particle is coat | covered with the insulating resin layer which consists of insulating resin which has a functional group, and the insulating resin layer has two or more other functional groups in 1 molecule which react with the said functional group. It is surface-treated with the polyfunctional compound which has, The insulating coating electroconductive particle characterized by the above-mentioned.

Moreover, this invention surface the surface of the said insulating resin layer of the electrically-conductive particle coat | covered with the insulating resin layer which consists of insulating resin which has a functional group with the polyfunctional compound which has 2 or more of other functional groups in 1 molecule which can react with this functional group. It provides the manufacturing method of the insulation coating electroconductive particle characterized by processing.

Furthermore, this invention provides the anisotropic conductive adhesive characterized by disperse | distributing the above-mentioned insulating coating electroconductive particle to an insulating adhesive agent.

Moreover, this invention is an anisotropic connection sheet material which has an anisotropic conductive layer which consists of an anisotropic conductive adhesive mentioned above, The low viscosity insulating adhesive layer which has a viscosity at the time of connection than the anisotropic conductive layer is lower than at least one side of this anisotropic conductive layer. Provided is an anisotropic connection sheet material formed.

In addition, the present invention ensures conduction between the electrodes of the first electronic component and the electrodes of the second electronic component, and in the connection method for adhering the electrodes to each other, the anisotropic conductivity described above between the opposing electrodes. Bonding the electrodes while sandwiching the adhesive or the anisotropic connection sheet material and applying pressure heating to remove the insulating resin layer of the contact portion of the insulating coated conductive particles in contact with both of the electrodes while ensuring conduction between the opposing electrodes. The connection method characterized by this, and this connection method provide the connection structure obtained by connecting the electrode of a 1st electronic component and the electrode of a 2nd electronic component.

Effects of the Invention

According to the present invention, excellent solvent resistance and conduction reliability can be simultaneously provided to the insulating coated conductive particles suitable for the conductive particles of the anisotropic conductive adhesive. Therefore, even if the anisotropic conductive adhesive obtained by disperse | distributing this insulating coating conductive particle to an insulating adhesive agent, and the anisotropic connection sheet material which has an anisotropic conductive layer which consists of this anisotropic conductive adhesive is manufactured by the process using a solvent, the insulation property of insulating coating conductive particle is carried out. Not only can it be ensured, but the density | concentration of the insulation coating electroconductive particle in an anisotropic conductive adhesive agent or anisotropic connection sheet material can be made high concentration. Therefore, when connecting between opposing electrodes using an anisotropic conductive adhesive or an anisotropic connecting sheet material, the number of insulating coating conductive particles which contribute to conduction between opposing electrodes can be increased, and high conduction with low conduction resistance is achieved. Reliability can be realized.

Carrying out the invention  Best form for

The insulation coating electroconductive particle of this invention is insulation coating electroconductive particle by which the surface of electroconductive particle is coat | covered with an insulating resin layer.

In this invention, insulating resin which has a functional group is used as insulating resin which comprises the insulating resin layer which coats electroconductive particle. Thereby, it becomes possible to improve the adhesiveness between electroconductive particle and insulating resin layer. Examples of such a functional group include a carboxyl group, an oxazoline group, an amino group, an epoxy group, a mercapto group, a substituent having hydrogen that can be drawn out as an active radical (for example, a saturated hydrocarbon group, an unsaturated hydrocarbon group), and the like. Moreover, the insulating resin which has such a functional group is insulating resin which has a monomer unit which has any one of these functional groups.

If the amount of these functional groups in the insulating resin is too small, the solvent resistance will not be sufficient. If the amount is too high, the crosslinking density will be excessive and the conduction reliability will be lowered. Therefore, it is appropriate to determine appropriately according to the type of the functional group or the type of the polyfunctional compound. desirable.

Specifically, as the insulating resin having a carboxyl group, a monomer unit having a carboxyl group, preferably an insulating resin having an acrylic acid monomer unit or a methacrylic acid monomer unit, for example, an acrylic acid styrene copolymer (PP-2000S, Dainippon Ink) Chemical industry corporation | Co., Ltd .; acid value 5 mgKOH / g or less), carboxylic acid modified styrene divinylbenzene copolymer (SX8742A, JSR Corporation make; acid value about 3.5 mgKOH / g), etc. are mentioned. The carboxyl group amount (acid value) in insulating resin becomes like this. Preferably it is 0.1-50 mgKOH / g, More preferably, it is 0.5-5 mgKOH / g.

As the insulating resin having an oxazoline group, an insulating resin having a monomer unit having an oxazoline group, preferably an oxazolylethylene monomer unit, for example, an oxazolyl ethylene styrene copolymer (Epocross RPS, Nihon Shokubai Co., Ltd.) Can be mentioned.

As insulating resin which has an amino group, the monomer unit which has an amino group, The insulating resin which has an amino alkylester monomer unit of (meth) acrylic acid, an acrylamide unit, etc. are mentioned preferably. The amino group amount in insulating resin becomes like this. Preferably it is 0.01-5 millimoles / g (insulating resin).

As the insulating resin having an epoxy group, for example, the epoxy resins exemplified in pages 2 to 40 of "High Performance of Epoxy Resin and Blending Technology and Evaluation of Curing Agent? Application (Publisher Information Technology Association, 1997, 12, 12)" Can be used.

As insulating resin which has a mercapto group, insulating resin which has a monomer unit which has a mercapto group, for example, terminal mercapto group containing polyvinyl alcohol, etc. of Unexamined-Japanese-Patent No. 2004-216703, etc. are mentioned.

As an insulating resin having a substituent having hydrogen that can be drawn out as an active radical, an insulating resin having a monomer, preferably an ethylene monomer, butadiene monomer, or isoprene monomer unit, which becomes a substituent having hydrogen that can be drawn out as an active radical, Polyethylene, polybutadiene, polyisoprene, etc. are mentioned, for example.

If the thickness of the insulating resin layer is too thin, electrical insulation will be insufficient, and if it is too thick, the conduction characteristics will be lowered, and therefore it is preferably 0.01 to 1 µm, more preferably 0.1 to 0.5 µm.

By the way, although the insulating coating electroconductive particle of this invention coat | covers the surface of an electroconductive particle with the insulating resin layer which consists of insulating resin which has a functional group as mentioned above, in order to ensure sufficient conduction reliability of an anisotropic conductive adhesive, it is insulating coating conductive The insulating resin layer itself of the particles needs to be excluded from the portion to be connected at the time of the thermocompression bonding process. Therefore, although the insulating resin layer itself needs to be thermoplastic under heat processing conditions, since it is easy to swell by an organic solvent and melt | dissolves in some cases, it is a problem with solvent resistance. Moreover, since a functional group, for example, a carboxyl group is easy to react with the epoxy group of the epoxy resin generally used as an adhesive component of an anisotropic conductive adhesive, there exists a possibility that the storage property of an anisotropic conductive adhesive may be reduced.

Therefore, in this invention, the insulating resin layer of insulation coating electroconductive particle is surface-treated with the polyfunctional compound which has 2 or more other functional groups which can react with the functional group of insulating resin. This surface treatment makes a functional group of a polyfunctional compound react with the functional group of insulating resin. Specifically, it can normally react by spraying the solution of a polyfunctional compound (for example, ethanol solution) on the surface of an insulating resin layer, heating and drying, and further heating to reaction temperature. Moreover, depending on the combination of functional groups, it can also make it react at the time of heat drying. Alternatively, the conductive particles coated with an insulating resin may be added to a solution of a polyfunctional compound (for example, an ethanol solution), stirred and dispersed, and reacted by heating and stirring to a temperature required for the reaction in that state. As a result, since the surface of the insulating resin layer is crosslinked by the polyfunctional compound, the solvent resistance of the insulating coating conductive particles can be improved without damaging the thermoplastic of the insulating resin layer, and the free functional group can be eliminated. Even if an epoxy resin is used, the storage property of the anisotropic conductive adhesive can be improved.

The polyfunctional compound which can be used by this invention has two or more other functional groups which can react with the functional group of insulating resin in 1 molecule, and is selected according to the functional group of insulating resin. Examples of such polyfunctional compounds include polyol compounds, polyamine compounds, polyisocyanate compounds, polycarbonate compounds, polyepoxy compounds, polyaziridine compounds, and organic peroxides.

As a preferable combination of the functional group and polyfunctional compound of insulating resin, a polyaziridine compound, a polyol compound, a polyamine compound, etc. are mentioned with respect to a carboxyl group, A polycarboxylic acid compound etc. are mentioned with respect to an oxazoline group, An amino group A polycarboxylic acid compound, a polyepoxy compound, etc. can be mentioned, A polyamine compound etc. are mentioned with respect to an epoxy group.

As a specific example of a polyol compound, polyester polyol, polyethyleneglycol, etc. are mentioned.

As a specific example of a polyamine compound, mencene diamine, isophorone diamine, diamino diphenylmethane, metaphenylenediamine, polycyclohexyl polyamine, and polyamide amine are mentioned.

Hexamethylene diisocyanate etc. are mentioned as a specific example of a polyisocyanate compound.

Specific examples of the polycarboxylic acid compound include cyclobutanetetracarboxylic acid, biphenyltetracarboxylic acid, benzophenone biphenyltetracarboxylic acid, pyromellitic acid and the like.

As a specific example of a polyepoxy compound, a bisphenol-type epoxy resin, a novolak-type epoxy resin, a cyclic aliphatic epoxy resin, a dimer acid type diglycidyl ester, etc. are mentioned.

Specific examples of the polyaziridine compound include trimethyrolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N, N-hexamethylene-1, 6-bis-1-aziridinecarboxyamide can be mentioned. Especially, trimethylolpropane- tri- (beta)-aziridinyl propionate is preferable at the point of reactivity.

As a specific example of an organic peroxide etc., a benzoyl peroxide etc. are mentioned.

Here, as a preferable aspect of the insulation coating electroconductive particle of this invention, the case where the substituent of the insulating resin which comprises an insulating resin layer is a carboxyl group, and a polyfunctional compound is a polyaziridine compound is mentioned. The surface treatment in this aspect makes the carboxyl group of insulating resin react with the aziridine group of a polyfunctional aziridine compound. Specifically, it can usually make it react by spraying the solution of a polyfunctional aziridine compound (for example, ethanol solution) on the surface of an insulating resin layer, and heating and drying at 80-140 degreeC. Moreover, it can also make it react by stirring and disperse | distributing the electrically-conductive particle coated with insulating resin to the solution (for example, ethanol solution) of a polyfunctional aziridine compound, and heating and stirring to 30-80 degreeC in that state. Thereby, since the carboxyl group of the surface of an insulating resin layer is bridge | crosslinked by an aziridine compound, since the solvent resistance of an insulation coating electrically conductive particle can be improved without damaging the thermoplastic of an insulating resin layer, and since free carboxyl group can be reduced, Even if an epoxy resin is used as the adhesive component, the storage properties of the anisotropic conductive adhesive can be improved.

In addition, the reaction of the aziridine group and the carboxyl group is well known (Encyclopedia of Chemical Technology, vol. 13, p142 to 166 (1984), etc.).

The usage-amount of a polyfunctional aziridine compound can be suitably determined by the number of aziridine groups of an aziridine compound, the carboxyl group equivalent of insulating resin, the grade of solvent resistance required, etc.

Moreover, as another preferable aspect of the insulation coating electroconductive particle of this invention, the case where the substituent of the insulating resin which comprises an insulating resin layer is an oxazoline group, and a polyfunctional compound is polycarboxylic acid is mentioned. The surface treatment in this aspect makes a carboxyl group of a polycarboxylic acid compound react with the oxazoline group of insulating resin. Specifically, it can normally react by spraying the solution (for example, ethanol solution) of a polycarboxylic acid compound on the surface of an insulating resin layer, and heating and drying at 80-140 degreeC. Moreover, it can also make it react by stirring and disperse | distributing the electrically-conductive particle coat | covered with insulating resin in the solution (for example, ethanol solution) of a polycarboxylic acid compound, and stirring by heating at 30-80 degreeC in that state. Thereby, since the surface of an insulating resin layer is bridge | crosslinked by a polycarboxylic acid compound, the solvent resistance of an insulation coating electroconductive particle can be improved, without damaging the thermoplastic of an insulating resin layer, and also the free oxazoline group and carboxylic acid Since it can eliminate, even if an epoxy resin is used as an adhesive component, the storage property of an anisotropic conductive adhesive can be improved.

In addition, the oxazoline group and the reaction of poly-carboxylic acid compound is well known and details, oxazolyl to involve ring-opening of ring sleepy amide ester _{(-CO 2 CH 2 CH 2 NHCO-} ) reaction to give the coupled.

The usage-amount of a polycarboxylic acid compound can be suitably determined by the number of carboxylic acids of a polycarboxylic acid compound, the oxazoline group equivalent of insulating resin, the grade of required solvent resistance, etc.

As the conductive particles used in the insulating coated conductive particles of the present invention, those having the same structure as those used in the conventional anisotropic conductive adhesive can be used. For example, metal particles, such as solder and nickel, resin particle coated with metal (nickel, gold, aluminum, copper, etc.) plating, glass particle, or ceramic particle, the particle | grains which insulated and coated these, etc. are mentioned. Especially, the metal coating resin particle which is easy to respond to the deviation of the smoothness of an electrode, for example, nickel gold plating coating resin particle can be used preferably. Moreover, what has surface protrusion can be used for these electroconductive particles as needed. In this case, corrosiveness is favorable to an electrode, and it is possible to improve conduction reliability.

When the average particle diameter of the electrically-conductive particle used by this invention is too small, conduction | electrical_connection reliability will fall, and when too large, insulation reliability will fall, Preferably it is 2-10 micrometers.

The insulation coating conductive particle of this invention arrange | positions the polyfunctional compound which has the other functional group which can react with the above-mentioned functional group on the surface of the said insulating resin layer of the conductive particle coat | covered with the insulating resin layer which consists of insulating resin which has a functional group. It can manufacture by making the functional group of insulating resin and other compound of a polyfunctional compound react by heating. More specifically, the surface of electroconductive particle is coat | covered with insulating resin by a conventional method, and the solution (for example, ethanol solution) of a polyfunctional aziridine compound is sprayed on the surface, and it dried at 80-140 degreeC It can react by heating. Moreover, it can make it react by adding the electrically-conductive particle coat | covered with insulating resin to the solution of a polyfunctional aziridine compound, and heating at 30-80 degreeC, stirring. In this case, the treated particles may be separated by filtration after the reaction.

The insulating coating conductive particle of this invention can be used suitably as a conductive particle of an anisotropic conductive adhesive agent. Such an anisotropic conductive adhesive can be produced by uniformly mixing the insulating coated conductive particles with the insulating adhesive which is an adhesive component by an ordinary method together with an organic solvent or an inorganic filler as necessary. This anisotropic electrically conductive adhesive agent can be made into a paste or a film form according to a conventional method.

When the compounding quantity of the insulation coating electroconductive particle in this anisotropic conductive adhesive agent is too small, conduction reliability will fall, and when too large, insulation reliability will fall, Preferably it is 1-30 volume%.

As an insulating adhesive agent used for this anisotropic conductive adhesive agent, a well-known thermoplastic insulating adhesive agent and a thermal or photocurable insulating adhesive agent can be used, For example, superposition | polymerization components, such as a liquid epoxy resin, an imidazole series hardening | curing agent and a modified amine type hardening | curing agent It consists of a thermosetting liquid insulating adhesive consisting of a curing agent component such as a curable component, an acrylate resin having a polymerizable double bond and a liquid insulating adhesive consisting of a curing catalyst, thermoplastic resins such as acrylic, SBR, SIS, polyurethane, and rubber resins. Liquid rubber adhesive etc. can be used.

Moreover, you may contain film forming resin which does not show adhesiveness, for example, a phenoxy resin, a polyester resin, a polyurethane resin, SEBS resin, SIS resin, an NBR resin, etc. in an insulating adhesive agent as needed.

Various additives, for example, a thickener, surfactant, etc. can be mix | blended with an anisotropic conductive adhesive as needed.

The anisotropic conductive adhesive of this invention can be manufactured by disperse | distributing insulating resin coating conductive particle to an insulating adhesive agent in accordance with a conventional method.

The anisotropic conductive adhesive of this invention can be used as an anisotropic connection sheet material by shape | molding in layer shape and making it an anisotropic conductive layer. In this case, it is preferable to form, on at least one side of the anisotropic conductive layer, a low viscosity insulating adhesive layer having a lower viscosity at the time of connection than the anisotropic conductive layer. With this configuration, since the viscosity of the anisotropic conductive layer becomes relatively higher than that of the low viscosity insulating adhesive layer at the time of connection, the flow of the anisotropic conductive layer is suppressed, and the outflow of conductive particles from between the electrodes to be connected can be prevented. It is possible to further improve conduction reliability.

It is preferable that the viscosity of the anisotropic conductive layer at the time of connection is at least 10 times or more higher than the viscosity of a low viscosity insulating adhesive bond layer.

As such a low viscosity insulating adhesive layer, what adjusted the component of the insulating adhesive agent used for the anisotropic electrically conductive adhesive agent mentioned above, and lowered the viscosity can be used.

It is preferable to set the thickness of the low-viscosity insulating adhesive layer to the thickness which can fill a space at least so that a short may not generate | occur | produce by the electrically conductive particle which flowed out into the interelectrode space at the time of connection. In some cases, by overcharging the space, a protruding portion can be formed around the connecting portion to function as a sealing material or a moisture proof material.

The anisotropic connection sheet material which has a low viscosity insulating adhesive layer can be manufactured by laminating an anisotropic conductive layer and a low viscosity insulating adhesive layer by a dry lamination method or a sequential coating method by a conventional method.

The anisotropic conductive adhesive or anisotropic connection sheet material of the present invention provides conduction between electrodes of first electronic components such as semiconductor chips and liquid crystal display elements, and electrodes of second electronic components such as semiconductor chip mounting substrates and liquid crystal drive substrates. In addition, it can be preferably used when the electrodes are bonded to each other while ensuring. In this case, the anisotropic conductive adhesive or anisotropic connection sheet material is sandwiched between the opposite electrodes to pressurize and heated to remove and insulate the insulating resin layer of the contact portion of the insulating coated conductive particles in contact with both of the electrodes. The electrodes can be bonded while securing conduction between the electrodes. Thus, the connection structure obtained by connecting the electrode of a 1st electronic component and the electrode of a 2nd electronic component will show favorable conduction reliability.

Hereinafter, the present invention will be described in detail with reference to examples.

Comparative Example 1

The surface of the conductive particles (AU204, Sekisui Chemical Co., Ltd.) in which the Ni / Au electroless plating layer was formed on the surface of the 4 μm diameter styrene resin particles was 0.2 μm thick by a conventional method. -2000S, and Dai Nippon Ink Chemical Co., Ltd.), the insulating coating electroconductive particle of the comparative example 1 was obtained.

Example 1

A solution in which 5 parts by weight of trimethylolpropane-tri-β-aziridinylpropionate (TAZM) was dissolved in 95 parts by weight of ethanol was evenly sprayed on the insulating coated conductive particles obtained in Comparative Example 1, followed by drying by heating at 100 ° C. The crosslinking reaction was performed by doing this, and the insulating coating electroconductive particle of Example 1 was obtained.

Example 2

100 weight part of insulation coating electroconductive particle obtained by the comparative example 1 is disperse | distributed to 100 weight part of ethanol, 2 weight part of trimethylolpropane- tri- (beta)-aziridinyl propionates (TAZM) are added to this dispersion liquid, and it is stirred and disperse | distributed After performing crosslinking reaction by heating and stirring at 65 degreeC for 4 hours, it isolate | separated by filtration and dried for 30 minutes at 80 degreeC, and obtained the insulating coating electroconductive particle of Example 2.

Example 3

Same as Example 2, except for using tetramethylolmethane-tri-β-aziridinylpropionate (TAZO) instead of trimethylolpropane-tri-β-aziridinylpropionate (TAZM) By operation, the insulation coating conductive particle of Example 3 was obtained.

Example 4

In addition to using N, N-hexamethylene-1,6-bis-1-aziridinecarboxyamide (HDU) in place of trimethylolpropane-tri-β-aziridinylpropionate (TAZM) By the same operation as in Example 2, the insulating coated conductive particles of Example 4 were obtained.

(evaluation)

10 parts by weight of each of the insulating coated conductive particles of Comparative Example 1 and Examples 1 to 4 were added to 90 parts by weight of three kinds of solvents such as toluene, MEK, or ethyl acetate, and left to stand at room temperature for 100 hours to insulate the coated conductive particles. Was precipitated and the supernatant was collected. The collected supernatant was heated to remove volatile components and the weight of the nonvolatile components was measured. This nonvolatile component corresponds to the weight of the insulating resin dissolved in the solvent. The ratio (weight%) melt | dissolved in the solvent in insulating resin is shown in Table 1.

Further, the precipitated insulating coated conductive particles were dried, and the resulting dried insulating coated conductive particles were charged between a pair of copper electrodes (φ6 mm × 125 μm), a voltage was applied between the electrodes, and the leaked voltage (withstand voltage) was measured. It was. The obtained results are shown in Table 1.

In addition, 35 parts by weight of phenoxy resin (YP50, Touto Chemical Co., Ltd.), 30 parts by weight of epoxy resin (YL980, Japan epoxy resin; epoxy equivalent 185 g / eq), epoxy dispersed imidazole series curing agent (HX3941HP, Asahi Kasei ( Note) An adhesive composition comprising 35 parts by weight, 20 parts by weight of conductive particles (conductive particles of Examples 1 to 4 or Comparative Example 1), 40 parts by weight of toluene, and 40 parts by weight of ethyl acetate, is applied to a peeled polyethylene terephthalate film. It applied so that it might become 25 micrometers in dry thickness, it dried at 80 degreeC for 5 minutes, the adhesive layer was formed, and the adhesive sheet was created. Insulation TEG for short evaluation which is in the ITO wiring arrange | positioned in the shape of comb-shaped on the glass substrate in the contact bonding layer surface of this adhesive sheet (chip size 25 * 2.5mm; number of bumps 8376; bump size 35 * 55micrometer; space between bumps 10 (Micrometer) was crimped | bonded on the conditions of 210 degreeC of arrival temperature, and 10 second of bonding time by the bonder. Then, the insulation resistance between the bumps was measured, and the occurrence rate of the short was calculated. The obtained results are shown in Table 1.

solvent Evaluation items
Comparative example Example One One 2 3 4 toluene
Dissolved content (wt%) 26.9 7.5 3.8 4.0 8.3 Withstand voltage (kV) 0.4 2.0 2.4 2.3 1.8 MEK
Dissolved content (wt%) 27.4 8.2 4.4 6.1 8.7 Withstand voltage (kV) 0.5 1.9 2.2 2.0 1.5 Ethyl acetate
Dissolved content (wt%) 26.6 7.2 4.0 5.8 7.9 Withstand voltage (kV) 0.6 2.1 2.6 2.1 1.6 Short occurrence rate (%) 6.2 0.3 0.0 0.0 0.5

As can be seen from Table 1, the insulating coated conductive particles of Examples 1 to 4 were superior in solvent resistance and withstand voltage resistance to the insulating coated conductive particles of Comparative Example 1 which were not surface treated with an aziridine compound in any solvent. Do. Therefore, conduction reliability is also improved. In addition, the incidence of short is very small, and good storage stability can be expected.

Example 5

(1) Formation of Anisotropic Conductive Layer

Liquid epoxy resin containing 50 parts by weight of a phenoxy resin (YP50, manufactured by Touto Kasei Co., Ltd.), 25 parts by weight of a solid epoxy resin (EP1009, Japan epoxy resin), and a microcapsule-type latent curing agent (HX3941HP, Asahi Kasei) Manufacture) The mixed resin composition which consists of 25 weight part was melt | dissolved in the mixed solvent which mixed MEK and toluene in the same weight, and obtained the 40 weight% resin solution.

The surface of the metal-coated resin particles coated with 0.2 µm thick nickel on polystyrene particles having an average particle diameter of 3 µm and coated with 0.02 µm thick gold was further subjected to oxazoline-modified polystyrene resin (Focross RPS, Nippon Shokubai Co., Ltd.). ) Is coated so as to have a thickness of 0.2 to 0.5 μm, and further treated with butanetetracarboxylic acid to prepare insulating coated conductive particles, and disperse the obtained insulating coated conductive particles to 10% by volume in the resin solution prepared first. I was.

The obtained dispersion liquid was apply | coated to the peeling process surface of the polyethylene terephthalate (PET) film which carried out the peeling process with silicone, and it apply | coated with a roll coater so that it might become 5 micrometers thickness in dry thickness, and dried at 80 degreeC for 5 minutes, and anisotropic conductive layer on PET Formed.

(2) Formation of Low Viscosity Insulating Adhesive Layer

MEK and toluene are the same in the mixed resin composition which consists of 50 weight part of solid epoxy resins (EP1009, Japan epoxy resin company), and 50 weight part of liquid epoxy resins (HX3941HP, Asahi Kasei Co., Ltd.) containing a microcapsule type latent hardener. It melt | dissolved in the mixed solvent mixed by weight and obtained the 40 weight% resin solution. By the same operation as when the anisotropic conductive layer was formed using the obtained resin solution, the 12-micrometer-thick low-viscosity insulating resin layer which does not contain electroconductive particle, and the low-viscosity insulation of 3 micrometers thickness were carried out on the peeling process PET film. The resin layer was produced.

(3) anisotropic conductive sheet material

The anisotropic conductive sheet material of Example 1 was produced by laminating a 12 micrometer-thick low-viscosity insulating resin layer on one side of the produced anisotropic conductive layer, and a 3 micrometer-thick low viscosity insulating resin layer on the other side.

Comparative Example 2

The anisotropic conductive sheet material was produced like Example 5 except having coat | covered the surface of electroconductive particle with the polystyrene resin (G100C, Toyo Styrol Co., Ltd.) of thickness 0.2-0.5 micrometer instead of oxazoline modified styrene resin.

Comparative Example 3

The surface of the conductive particles was coated with a cured product (0.2 to 0.5 µm thick) of a liquid epoxy resin (HX3941HP, Asahi Kasei Co., Ltd.) containing a microcapsule latent curing agent in place of the oxazoline modified styrene resin. In the same manner as in Example 5, an anisotropic conductive sheet material was produced.

(4) evaluation

(4a) Number of conductive particles per one electrode (bump) of IC chip

Prior to evaluation, a connection IC chip and a circuit board were prepared. The specifications of the IC chip used for evaluation are chip size 2.5mm square, 8376 bump number, 35 x 55 micrometers of gold plating bumps, 10 micrometers of bump spaces, and 15 micrometers of bump heights. The circuit board arrange | positions ITO wiring on a glass substrate. The anisotropic conductive sheet material was sandwiched between this IC chip and a circuit board, and it bonded by thermobonding on the conditions of 210 degreeC and mounting time of 10 second by bonder, and obtained the bonded structure. From the circuit board side of this bonded structure, the bump of 200 points | pieces was counted using the optical microscope of 340 times the magnification, and the number of electroconductive particles which remain | survives in one bump of an IC chip was counted. The obtained results are shown in Table 2. From the viewpoint of conduction reliability, it is desired that at least five conductive particles remain on the bumps.

(4b) conduction reliability

The sample similar to the sample used for evaluation of the number of electroconductive particles per bump of an IC chip was produced, and this was aged for 24 hours using the pressure cooker tester (EHS-411, Tabbyec's company). After the end of aging, the conduction resistance between the electrodes of the samples opposed to each other was measured. The obtained results are shown in Table 2. The case where conduction resistance was 20 ohms or less was evaluated as "G" (Good), and the case where it exceeded 20 ohms was evaluated as "NG" (No good).

(4c) insulation reliability

The same sample as the sample used in the evaluation of conduction reliability was produced, and the insulation resistance between adjacent electrodes of this sample was measured. The obtained results are shown in Table 2. The case where it was less than 1 * 10 <^8> ohms was evaluated as "NG" (No Good), and the case where insulation resistance is 1 * 10 <^8> ohms or more was evaluated as "G" (Good).

Number of conductive particles on bumps Continuity reliability Insulation reliability Example 5 20 G G Comparative Example 2 19 G NG Comparative Example 3 22 NG G

From the results of Example 5 in Table 2, when the low viscosity insulating adhesive layer is formed on the anisotropic conductive layer, the number of conductive particles remaining on the bumps at the time of connection increases, so that the number of conductive particles entering between relatively adjacent electrodes decreases. It turns out that insulation reliability improves.

Moreover, in the case of the comparative example 2 which used the thing which does not have a functional group as insulating resin of insulating coating electroconductive particle, since surface crosslinked structure cannot be expected, the fall of solvent resistance was anticipated and it was actually lacking insulation reliability. Moreover, although it has a functional group as insulating resin of an insulation coating electroconductive particle, it turns out that there exists a problem in conduction reliability in the case of the comparative example 3 which hardens | cures to self-complete | finish and cannot expect reaction with butane tetracarboxylic acid.

Since the insulation coating conductive particle of this invention is excellent in solvent resistance and withstand voltage resistance, the conduction | electrical_connection reliability is improved, and the occurrence rate of a short is very small and favorable storage stability can be expected, the electroconductive particle of an anisotropic conductive adhesive agent Useful as

Claims (13)

Insulating coating electrically-conductive particle which the surface of electroconductive particle is coat | covered with the insulating resin layer which consists of insulating resin which has a functional group, The insulating resin layer has a polyfunctional compound which has 2 or more of other functional groups in 1 molecule which can react with this functional group. And the surface-treated, functional group of the insulating resin is a carboxyl group, and the polyfunctional compound is a polyaziridine compound. delete delete delete The method of claim 1, The aziridine compound is trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate or N, N-hexamethylene-1,6-bis-1- Insulation coating conductive particle which is an aziridine carboxyamide. The method of claim 1, Insulation coating electroconductive particle whose insulating resin layer is comprised from the insulating resin which has an acrylic acid monomeric unit or a methacrylic acid monomeric unit. The method of claim 6, Insulation coating electroconductive particle whose insulating resin is an acrylic acid styrene copolymer. Insulation coating conductivity which surface-treats the surface of the said insulating resin layer of the electrically-conductive particle coat | covered with the insulating resin layer which consists of insulating resin which has a functional group with the polyfunctional compound which has 2 or more of other functional groups which can react with this functional group in 1 molecule. The manufacturing method of particle | grains WHEREIN: The functional group of the said insulating resin is a carboxyl group, and the said polyfunctional compound is a polyaziridine compound, The manufacturing method of the insulating coating conductive particle characterized by the above-mentioned. The insulating coating conductive particle of Claim 1 disperse | distributes to an insulating adhesive agent, The anisotropic conductive adhesive agent characterized by the above-mentioned. The method of claim 9, The anisotropic conductive adhesive whose insulating adhesive contains an epoxy resin. An anisotropic connection sheet material having an anisotropic conductive layer made of the anisotropic conductive adhesive according to claim 9, wherein a low viscosity insulating adhesive layer having a lower viscosity at the time of connection than the anisotropic conductive layer is formed on at least one side of the anisotropic conductive layer. Anisotropic Connection Sheet Material. In the connection method which ensures the conduction between the electrode of a 1st electronic component, and the electrode of a 2nd electronic component, and adhere | attaches these electrodes mutually, the anisotropic conductive adhesive of Claim 9 or between these opposing electrodes, By clamping and anisotropically connecting the anisotropic connection sheet material of claim 11, the electrode is bonded while removing the insulating resin layer of the contact portion of the insulating coated conductive particles in contact with both of these electrodes while ensuring conduction between the opposing electrodes. The connection method characterized by the above-mentioned. The connection structure in which the electrode of a 1st electronic component and the electrode of a 2nd electronic component are connected by the connection method of Claim 12.