KR102334672B1 - Curable composition and electronic component - Google Patents

Abstract

(Project) To provide the curable composition which does not have the conventional problem, can ensure the adhesive strength excellent at low temperature, low pressure, and a short time, and can electrically connect members.
(Solution) The curable composition of the present invention is characterized in that it contains (A) a compound having an ethylenically unsaturated bond, (B) a peroxide, and (C) a solder powder.
In addition, the curable composition of the present invention is a composition containing (A) an organic component including a compound having an ethylenically unsaturated bond, (B) a peroxide, (D) an organic binder, and (C) a conductive powder, It is characterized in that the ethylenically unsaturated bond equivalent in the component (when a solvent is included, the solvent is excluded) is 260 or more.

Description

Curable composition and electronic component {CURABLE COMPOSITION AND ELECTRONIC COMPONENT}

The present invention relates to a curable composition, and more particularly, to a curable composition suitable for use in electronic components as a conductive adhesive capable of electrically connecting members at a low temperature, a low pressure, and in a short time.

In the field of electronic devices or circuit formation technology for electronic devices, a method has been used to obtain conductivity and connection strength by melting cream solder obtained by kneading solder powder and flux when electronic components are mounted on a substrate. However, since it is necessary to process at a high temperature in order to electrically connect members using such a cream solder, consideration for reliably protecting a mounted component from heat was calculated|required.

On the other hand, there has been proposed a technique of a conductive adhesive that enables conductive connection at a low temperature by using a low-melting-point solder and reinforces the adhesive strength of the low-melting-point solder using an epoxy resin (Patent Document 1). However, this prior art has a problem that the solder paste cannot be cured in a short time.

On the other hand, as a technique of a conductive adhesive that cures a low-melting-point solder paste in a short time, treatment at a high temperature is disclosed (Patent Document 2). However, satisfactory adhesive strength could not be obtained in this prior art.

As described above, the present situation is that a technique for enabling a conductive connection excellent in adhesive strength at a low temperature and a low pressure in a short time with a conductive adhesive such as a solder paste has not yet been proposed.

Japanese Patent Laid-Open No. 2012-115871 Japanese Patent Laid-Open No. 2013-51353

An object of the present invention is to provide a curable composition suitably used as a conductive adhesive capable of securing excellent adhesive strength at a low temperature and a low pressure and in a short period of time, and capable of electrically connecting members.

MEANS TO SOLVE THE PROBLEM The present inventors came to complete the invention which makes the following content a summary structure, as a result of earnestly examining in order to solve the said subject.

That is, the curable composition of the present invention comprises (A) a compound having an ethylenically unsaturated bond, (B) a peroxide, and (C) an electrically conductive powder.

That is, the curable composition of the present invention further comprises (D) an organic binder,

The ethylenically unsaturated bond of the curable composition in the organic component (excluding the solvent when a solvent is included) comprising (A) the compound having an ethylenically unsaturated bond, (B) a peroxide, and (D) an organic binder It is characterized in that the equivalent weight is 260 or more.

Curable composition of this invention WHEREIN: It is preferable that the said (A) compound which has an ethylenically unsaturated bond is a (meth)acryloyl group containing compound.

In this specification, a (meth)acryloyl group is a term generically naming an acryloyl group, a methacryloyl group, and mixtures thereof, and the same applies to similar expressions, such as (meth)acrylate.

The curable composition of the present invention WHEREIN: It is preferable that the said (B) peroxide is liquid. The liquid (B) peroxide is more preferably at least one compound selected from peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxycarbonate and peroxyester.

In the curable composition of the present invention, the (C) conductive powder is preferably a low-melting-point solder powder.

Moreover, it is preferable that the curable composition of this invention does not contain a solvent. In the present invention, "no solvent is used" or "solvent free" means that the curable composition does not contain a solvent substantially, and the decrease in mass by heating at 150° C. for 30 minutes of the composition is 3 compared to the mass before heating. It means that it is less than mass %.

The curable composition of this invention is used suitably as a conductive adhesive of an electronic component, and members are electrically connected to the electronic component obtained.

ADVANTAGE OF THE INVENTION According to this invention, the curable composition used suitably as a conductive adhesive which can ensure the adhesive strength excellent in low temperature, low pressure and a short time and can electrically connect members can be provided.

The curable composition of the present invention comprises (A) a compound having an ethylenically unsaturated bond, (B) a peroxide, and (C) an electrically conductive powder.

The curable composition of the present invention further contains (D) an organic binder, and an organic component comprising (A) a compound having an ethylenically unsaturated bond, (B) a peroxide and (D) an organic binder (when a solvent is included) It is characterized in that the ethylenically unsaturated bond equivalent in the solvent is 260 or more.

The conductive powder (C) used in the present invention is preferably a low-melting-point solder powder, more preferably a low-melting-point lead-free solder, and contributes to electrical connection between members in an electronic component.

The curable composition of the present invention preferably contains (C) no lead at all in components other than the conductive powder, (A) a compound having an ethylenically unsaturated bond, and (B) a peroxide; One (C) is to reinforce the electrical connection by the conductive powder in terms of adhesive strength. In particular, by using (B) peroxide, (A) curing of the compound having an ethylenically unsaturated bond is performed at a low temperature and in a short time. In addition, it was found that, by using a liquid peroxide as the peroxide, an effect peculiar to the present invention that the paste is also excellent in storage stability is obtained.

ADVANTAGE OF THE INVENTION According to the curable composition of this invention, since cure shrinkage which generate|occur|produces at the time of hardening is suppressed, the outstanding adhesive strength can be obtained.

In general, the smaller the ethylenically unsaturated bond equivalent, the greater the amount of ethylenically unsaturated groups contained in the composition. Therefore, the crosslinking point during the curing reaction increases and a cured product having a high crosslinking density is obtained. In addition, the higher the density of the reactor, that is, the higher the concentration of the reactor is, the better the reactivity, which is advantageous for low-temperature and short-time curing.

However, as a result of earnest examination, the inventors discovered that the crosslinking density was reduced and the fall of the adhesive strength by cure shrinkage could be suppressed by daringly enlarging an ethylenically unsaturated bond equivalent. In addition, in the present invention, by introducing an organic binder and peroxide, curing at a low temperature and in a short time is possible, and the adhesive strength is improved.

[Ethylenic unsaturated bond equivalent]

The ethylenically unsaturated bond equivalent in the present invention is a mass per gram equivalent in terms of the number of ethylenically unsaturated bonds. When an ethylenically unsaturated group is a (meth)acryloyl group, it is also generally called (meth)acryl equivalent.

For example, when an ethylenically unsaturated group is a (meth)acryloyl group, it is defined as the mass of the organic component (a solvent is excluded when a solvent is included) per (meth)acryloyl group.

That is, the ethylenically unsaturated bond equivalent of the curable composition in the present invention is an organic component ((A) compound having an ethylenically unsaturated bond + (B) peroxide + (D) organic binder + other organic components) (solvent When it contains, it can obtain by dividing the total mass of the solvent by the number of ethylenically unsaturated bonds in a composition.

The components constituting the curable composition of the present invention will be described below.

[(A) a compound having an ethylenically unsaturated bond]

The curable composition of this invention is a composition containing (A) the compound which has an ethylenically unsaturated bond.

(A) The compound having an ethylenically unsaturated bond can be used without particular limitation as long as it has an ethylenically unsaturated bond, but a (meth)acryloyl group-containing compound is preferable. In addition to the following monomers, these oligomers can also be used.

Examples of the (meth)acryloyl group-containing compound include substituted or unsubstituted aliphatic acrylates, alicyclic acrylates, aromatic acrylates, heterocyclic acrylates and ethylene oxide-modified acrylates and epoxy acrylates; Urethane acrylate, polyester acrylate, polyether acrylate, polyol acrylate, alkyd acrylate, melamine acrylate, silicone acrylate, polybutadiene acrylate, and corresponding methacrylates can be used.

More specifically, as monofunctional (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate ) acrylate, hydroxypropyl (meth) acrylate, butoxymethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, glycerol mono Aliphatic (meth)acrylates, such as (meth)acrylate, cyclohexyl (meth)acrylate, 4-(meth)acryloxytricyclo[5.2.1.02.6]decane, isobornyl (meth)acrylate, such as Aromatics, such as alicyclic (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate Modified (meth)acrylate, such as meth)acrylate, aliphatic epoxy-modified (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-(meth)acryloxyalkyl phosphate, 2-(meth)acryloyloxy Ethyl phosphoric acid ester, (meth)acryloyloxyethyl phthalic acid, (gamma)-(meth)acryloxyalkyl trialkoxysilane, etc. are mentioned.

In addition, as polyfunctional (meth)acrylate, bisphenol-A-di(meth)acrylate, alkylene oxide-modified bisphenol-A-di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1, 6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylic Rate, polypropylene glycol di(meth)acrylate, bis(2-(meth)acryloyloxyethyl)phosphate ester, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipenta Erythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, bis[4-(meth)acryloxymethyl]tricyclo[5.2.1.02.6]decane, bis[4-(meth)acryl Oxy-2-hydroxypropyloxyphenyl] propane, isophorone diisocyanate-modified urethane (meth) acrylate, hexamethylene diisocyanate-modified urethane (meth) acrylate, oligosiloxanyl di (meth) acrylate, trimethyl hexamethylene di Isocyanate-modified urethane (meth) acrylate, triallyl isocyanurate, vinyl (meth) acrylate, allyl (meth) acrylate, and the like can be used.

In addition, as a compound which has (A) ethylenically unsaturated bond of this invention, the following compounds can also be used.

(1) Liquid polybutadiene urethane (meth) acrylate obtained by urethane addition reaction of 2-hydroxyethyl (meth) acrylate with the hydroxyl group of liquid polybutadiene through 2,4-tolylene diisocyanate;

(2) liquid polybutadiene acrylate obtained by esterifying 2-hydroxyacrylate with maleic polybutadiene to which maleic anhydride is added;

(3) liquid polybutadiene (meth)acrylate obtained by an epoxy esterification reaction of a carboxyl group of polybutadiene with glycidyl (meth)acrylate;

(4) liquid polybutadiene (meth)acrylate obtained by esterification of epoxidized polybutadiene obtained by making an epoxidizing agent act on liquid polybutadiene and (meth)acrylic acid;

(5) liquid polybutadiene (meth)acrylate obtained by dechlorination reaction between liquid polybutadiene having a hydroxyl group and (meth)acrylic acid chloride, and

(6) Liquid hydrogenated 1,2 polybutadiene (meth) acryl obtained by urethane (meth) acrylate modification of liquid hydrogenated 1,2 polybutadiene glycol obtained by hydrogenating double bonds of liquid polybutadiene having hydroxyl groups at both ends of the molecule rate is preferably used.

Examples of these commercially available products include NISSO PB TE-2000, NISSO PB TEA-1000, NISSO PB TE-3000, NISSO PB TEAI-1000 (all of the above are manufactured by Nippon Soda Corporation), MM-1000-80, MAC-1000- 80 (all of the above are manufactured by Nippon Seki Chemical Co., Ltd.), Polyvek ACR-LC (manufactured by Nippon Hydrajin Kogyo Co., Ltd.), HYCAR VT VTR 2000 x 164 (manufactured by Ube Kosang Industries, Ltd.), Quinbeam 101 (manufactured by Nippon Zeon Corporation), Chemlink 5000 (manufactured by SARTOMER), BAC-15 (manufactured by Osaka Yuki Chemical Co., Ltd.), BAC-45 (Osaka Yuki Chemical) (manufactured by Kogyo Co., Ltd.), UAT-2000 (manufactured by Kyoe Sha Chemicals), EPOLID PB-3600 (manufactured by Daicel Chemicals, Inc.), EY RESIN, BR-45UAS (Light) Chemical High School Co., Ltd.) etc. are mentioned.

Among these, in particular 2-hydroxy-3-phenoxypropylacrylate, phenoxyethylacrylate, 4-hydroxybutylacrylate, tetrahydrofurfurylacrylate, 2-hydroxyethylacrylate, 2-hydroxypropyl Acrylate and 2-acryloyloxyethyl phthalic acid are preferably used.

These (A) compounds which have an ethylenically unsaturated bond can be used 1 type or in mixture of 2 or more types.

The compound having an ethylenically unsaturated bond as described above is blended so that the ethylenically unsaturated bond equivalent in the organic component excluding the solvent of the composition is 260 or more. Preferably it is 260-1000, More preferably, it is 260-700, More preferably, it is 310-500, More preferably, it is set as 330-500. By setting the ethylenically unsaturated bond equivalent to 260 or more, curing shrinkage generated during curing is suppressed, and sufficient adhesive strength can be obtained. Moreover, sufficient sclerosis|hardenability can be acquired by making an ethylenically unsaturated bond equivalent into 1000 or less.

By using the (B) peroxide mentioned later with respect to this (A) compound which has an ethylenically unsaturated bond, reaction is started quickly, rapid hardening becomes possible, and adhesive strength becomes favorable.

Here, the compounding quantity of this (A) compound which has an ethylenically unsaturated bond is 10-90 mass % with respect to the total mass of curable composition, Preferably it is 20-70 mass %, More preferably, it is 25-60 mass %.

(A) When the compounding quantity of the compound which has an ethylenically unsaturated bond shall be 10 mass % or more with respect to the gross mass of a curable composition, sufficient sclerosis|hardenability is acquired and adhesive strength also becomes favorable. Moreover, cure shrinkage is suppressed and adhesive strength also becomes favorable because (A) the compounding quantity of the compound which has an ethylenically unsaturated bond shall be 90 mass % or less with respect to the gross mass of a curable composition.

[(B) Peroxide]

The curable composition of the present invention contains (B) peroxide as a polymerization initiator for the compound (A) having an ethylenically unsaturated bond.

(B) A radical reaction of a compound having an ethylenically unsaturated bond is initiated by the peroxide. As a result, the adhesive force of the members in an electronic component improves.

The peroxide (B) used in the present invention includes liquid and powder peroxide, and specific examples include the following materials.

Ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide and acetylacetone peroxide, 1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di( peroxyketals such as t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)-2-methylcyclohexane and 1,1-di(t-butylperoxy)cyclohexane; 2-di(t-butylperoxy)butane, n-butyl4,4-di-(t-butylperoxy)valerate and 2,2-di(4,4-di-(t-butylperoxy) Peroxyketals such as cyclohexyl) propane, p-mentane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, and t-butyl hydroperoxide Hydroperoxide such as oxide, di(2-t-butylperoxyisopropyl)benzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylcumylperoxide Dialkyl peroxides such as oxide, di-t-hexyl peroxide, di-t-butyl peroxide and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, diisobutyl peroxide Oxide, di (3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, disuccinic acid peroxide, di- (3-methylbenzoyl) peroxide, benzoyl (3-methylbenzoyl) peroxide, di Diacyl peroxides such as benzoyl peroxide and di-(4-methylbenzoyl) peroxide, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, and di(4-t-butylcyclohexyl) Peroxydicarbonates such as peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, and di-sec-butylperoxydicarbonate, cumylperoxyneodecanoate, 1,1,3 ,3-Tetramethylbutylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxyneoheptanoate, t-hexylperoxypivalate , t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy) Hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t- butyl peroxy -3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexyl silperoxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxyacetate, t-butylperoxy-3-methylbenzoate, t-butylperoxybenzoate and Peroxyesters, such as t-butylperoxyallyl monocarbonate, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone.

Among these peroxides, it is preferable to use a liquid one. By using a liquid peroxide, it is excellent also in storage stability of a curable composition. Here, the liquid peroxide means a liquid peroxide at room temperature (25°C) and atmospheric pressure.

(B) By using a peroxide, (A) curing of the compound having an ethylenically unsaturated bond is performed at a low temperature and in a short time. Moreover, by using a liquid thing as (B) peroxide, it is excellent also in storage stability of a curable composition.

Usually, in thermosetting compositions, a powder curing agent is blended to impart a function as a latent curing agent, but in the present invention, it was unexpectedly found that the storage stability of the curable composition was improved by using the liquid (B) peroxide. As a result, according to the liquid (B) peroxide, it is well dispersed in the curable composition and acts favorably on the compound having (A) an ethylenically unsaturated bond to accelerate curing.

As the liquid (B) peroxide, for example, ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide and acetylacetone peroxide, 1,1-di(t-hexylperoxy)-3,3,5 -trimethylcyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)-2-methylcyclohexane and 1,1-di(t-butylperoxy) ) peroxyketals such as cyclohexane, 2,2-di(t-butylperoxy)butane, n-butyl(4,4-di-(t-butylperoxy)valerate, and 2,2-di(4) Peroxyketals such as ,4-di-(t-butylperoxy)cyclohexyl)propane, p-mentane hydroperoxide, diisopropylbenzenehydroperoxide, 1,1,3,3-tetramethylbutylhydroperoxide Hydroperoxides such as oxide, cumene hydroperoxide and t-butyl hydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylcumyl peroxide, di-t- Dialkyl peroxides such as hexyl peroxide, di-t-butyl peroxide and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, diisobutyl peroxide, di(3, 5,5-trimethylhexanoyl) peroxide, di-(3-methylbenzoyl) peroxide and diacyl peroxides such as benzoyl (3-methylbenzoyl) peroxide and dibenzoyl peroxide, di-n-propyl peroxydica Peroxydicarbonate, cumylperoxyneodecanoate, such as lebonate, diisopropyl peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, and di-sec-butylperoxydicarbonate , 1,1,3,3-tetramethylbutylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxyneoheptanoate, t -Hexylperoxypivalate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2- Ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-hexylperoxyisopropyl monocarbonate, t-butylper Oxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t- hexyl peroxy Peroxyesters such as benzoate, t-butylperoxyacetate, t-butylperoxy-3-methylbenzoate, t-butylperoxybenzoate and t-butylperoxyallyl monocarbonate, and 3,3 ',4,4'-tetra(t-butylperoxycarbonyl)benzophenone is mentioned.

Among these, in the present invention, it is particularly preferable to use the following peroxides.

1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, n-butyl-4,4-di-(t -Peroxyketals such as butylperoxy)valerate, hydroperoxides such as 1,1,3,3-tetramethylbutylhydroperoxide, and 2,5-dimethyl-2,5-di(t-butylperoxy) ) hexane, t-butylcumyl peroxide, di-t-hexyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, etc. Alkyl peroxide, diacyl peroxide, peroxycarbonate and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t- Butylperoxy-2-ethylhexanoate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,3,5-trimethylhexanoate, t-butylperoxylaurate, t- and peroxyesters such as butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, t-butylperoxy-3-methylbenzoate and t-butylperoxybenzoate.

Moreover, excellent adhesiveness is obtained by using peroxyester among the said especially preferable peroxides. Among them, alkyl peroxy esters

By using , very excellent adhesive strength is obtained.

As described above, (B) peroxide has a half-life temperature of 80°C to 160°C for 1 minute, preferably 85°C to 145°C, and more preferably 90°C to 135°C.

By setting the half-life temperature to 80°C or higher for 1 minute, a sufficient pot life can be ensured for use at room temperature. Moreover, sufficient sclerosis|hardenability can be ensured by making the half-life temperature into 160 degreeC or less for 1 minute.

(B) Although a peroxide is used individually, it can also be used combining several types.

The compounding quantity of such (B) peroxide is 0.1-10 mass % with respect to the total mass of curable composition, Preferably it is 0.5-5 mass %, More preferably, it is selected suitably in the range of 1-3 mass %.

Sufficient sclerosis|hardenability can be ensured by the compounding quantity of (B) peroxide being 0.1 mass % or more with respect to the compound which has (A) ethylenically unsaturated bond. Moreover, sufficient adhesiveness can be ensured by the compounding quantity of a peroxide being 10 mass % or less with respect to the compound which has (A) ethylenically unsaturated bond.

[(C) conductive powder]

(C) Conductive powder is contained in the curable composition of this invention. The conductive powder of the present invention means a powder of a substance having a ^{volume resistivity of 1×10 6 Ω·cm or less.}

The members are electrically connected to each other by this (C) conductive powder.

Examples of the conductive powder (C) include metal powders of Sn, Bi, In, and Sb, carbon powders, etc. made of materials such as Au, Ag, Ni, Cu, Pd and low-melting-point solder mentioned later. The conductive powder may be a composite powder in which a non-conductive powder such as glass, ceramic, or plastic as a nucleus is coated with a metal layer, or a composite powder having the non-conductive powder and a metal powder or carbon powder. If the conductive powder is the composite powder or heat-meltable metal powder, the conductive powder is deformed by heating and pressing, so that the contact area with the electrode is increased during connection, and particularly high reliability is obtained. Moreover, as this (C) electroconductive powder, a silver-coated copper powder and the metal powder which has a shape in which many fine metal powders were connected in chain|strand can also be used.

In the curable composition of the present invention (C), the conductive powder is preferably a low-melting-point solder powder, does not contain lead, and a low-melting-point solder powder is more suitably used.

Here, the low-melting-point solder powder means a solder powder having a melting point of 200°C or lower, preferably 170°C or lower, and more preferably 150°C or lower.

In addition, the solder powder containing no lead means the solder powder with a lead content of 0.10 mass % or less prescribed|regulated by JIS Z 3282 (Solder-chemical composition and shape).

As the lead-free solder powder, a low-melting-point solder composed of at least one metal selected from tin, bismuth, indium, copper, silver and antimony is suitably used. In particular, an alloy of tin (Sn) and bismuth (Bi) is preferably used from the viewpoint of the balance between cost, handleability and bonding strength.

The content of Bi in the solder powder is appropriately selected within the range of 15 to 65 mass%, preferably 35 to 65 mass%, and more preferably 55 to 60 mass%.

When the content of Bi is 15% by mass or more, the alloy starts melting at about 160°C. When the content of Bi is further increased, the melting initiation temperature decreases, the melting initiation temperature becomes 139°C at 20% by mass or more, and the eutectic composition at 58% by mass or more. When the Bi content is in the range of 15 to 65% by mass, the effect of lowering the melting point can be sufficiently obtained, and therefore sufficient conduction connection can be obtained even at a low temperature.

It is preferable that this (C) electrically conductive powder is spherical particle|grains, It is preferable that average particle diameter D50 is 0.1 micrometer - 20 micrometers, Preferably they are 3 micrometers - 17 micrometers, More preferably, they are 7 micrometers - 15 micrometers. (C) When the average particle diameter D50 of the conductive powder is 20 µm or less, sufficient conductive connection is attained even in a fine location. Moreover, the aggregation of the electrically-conductive powder in curable composition can be suppressed by (C) the average particle diameter D50 of an electrically-conductive powder being 0.1 micrometer or more.

The compounding quantity of (C) electroconductive powder as demonstrated above is 5-60 mass % in curable composition, Preferably it is 15-45 mass %, More preferably, it is selected suitably in 25-35 mass %.

(C) Sufficient conduction|electrical_connection connection is securable by the compounding quantity of an electrically-conductive powder being 5 mass % or more in curable composition. Moreover, sufficient adhesiveness is securable by the compounding quantity of (C) electrically conductive powder being 60 mass % or less in curable composition.

[(D) organic binder]

The curable composition of the present invention is a composition comprising (D) a compound having an organic binder. By adding this organic binder, the stress generated during thermal curing is relieved, and the adhesive strength is further improved.

An organic binder is an organic resin component, and a well-known and usual natural resin and synthetic resin can be used.

Examples of such organic binders include natural resins such as cellulose and rosin, polyethylene, polypropylene, polystyrene, polycarbonate, polyvinyl chloride, polyvinyl acetate, polyamide, acrylic resin, polyethylene terephthalate, fluororesin, silicone resin, and polyester. Synthetic resins, such as resin, an acetal resin, and a butyral resin, can be used. Especially, it is preferable to use an acrylic resin, a butyral resin, and a saturated polyester resin.

Specific examples of the butyral resin include S-Rec BL-1, BL-1H, BL-2, BL-2H, BL-5, BL- of Sekisui Chemical S-Rec series (manufactured by Sekisui Chemical Co., Ltd.). 10, BL-S, BL-L, and the like.

Specific examples of the saturated polyester resin include Byron 200, 220, 240, 245, 270, 280, 290, 296, 300, 337, 500, 530, 550, 560 of the Toyobo Byron series (manufactured by Toyobo Industries, Ltd.). , 600, 630, 650, BX1001, GK110, 130, 140, 150, 180, 190, 250, 330, 590, 640, 680, 780, 810, 880, 890. As a specific example of an acrylic resin, Kurarit LA2330 of Kurarit series (manufactured by K.K.), etc. are mentioned.

It is preferable to use the organic binder which is solid at room temperature (25 degreeC) and atmospheric pressure. By using a solid organic binder, it becomes easy to maintain the intensity|strength after hardening of a curable composition. The Tg (glass transition temperature) of the organic binder is preferably -20 to 150°C, preferably 0 to 120°C, more preferably 10 to 70°C.

(D) The molecular weight of the organic binder is preferably 1,000 to 100,000, preferably 3,000 to 80,000, more preferably 5,000 to 60,000. When the molecular weight is 1,000 or more, stress can be relieved without bleeding out during curing, and when it is 100,000 or less, it is easily compatible with the compound having an ethylenically unsaturated bond, and sufficient fluidity can be obtained.

(D) The compounding quantity of an organic binder is 1-90 mass % with respect to the total mass of a curable composition, Preferably it is 3-60 mass %, More preferably, it is 5-40 mass %.

[Other ingredients]

As described above, the curable composition of the present invention may contain additives such as a known and usual thixotropic imparting agent, an antifoaming agent, and a leveling agent, if necessary.

In addition, in order to remove the oxide film of copper, the activator which has a carboxyl group is generally used for the curable composition or solder paste used for the copper electrode used for an electronic device or a circuit of an electronic device, etc.

However, since electrodes used for display members such as liquid crystal panels and touch panels are formed of a material other than copper such as a conductive paste such as silver or sputtering such as aluminum, these electrodes are formed by the activator having a carboxyl group. The inventors realized that it corrodes easily.

Then, it is preferable that the curable composition of this invention does not contain the activator which has a carboxyl group in a composition.

The curable composition of this invention is used for the electrical connection of members in an electronic component.

For example, the curable composition of this invention is apply|coated to the electrical connection location of the connection member in a printed wiring board etc. by pattern printing with a screen mesh or a metal mask, or coating devices, such as a dispenser.

After confirming that the curable composition has been sufficiently supplied to the connection portion, the member (part) to be connected is placed on the connection portion of the connection member (substrate), and is cured by thermocompression at a predetermined temperature and a predetermined pressure. Thereby, the connecting member (substrate) and the to-be-connected member (component) are electrically connected.

In this invention, since the outstanding adhesive strength is obtained by thermocompression bonding at low temperature, low pressure, and a short time, damage does not affect an electronic component.

Specifically, the thermocompression compression temperature is 100° C. to 240° C., preferably 120° C. to 200° C., more preferably 140 to 160° C., and the thermocompression compression pressure is 0.05 MPa to 3.0 MPa, preferably 0.1 MPa to 2.0 MPa, more preferably 0.5 MPa to 1.5 MPa, and thermocompression bonding time is 1 second to 60 seconds, preferably 1 second to 20 seconds, more preferably 1 second to 9 seconds. According to the treatment at a temperature of 100°C or higher, the reaction of the compound having an ethylenically unsaturated bond proceeds favorably, and by performing the treatment at a temperature of 240°C or lower, the electronic component to be bonded is not damaged by heating. and maintain its original performance. In addition, by setting the pressure to 0.05 MPa or more, sufficient bonding is formed between electronic components and the conductivity is also sufficient, and by setting the pressure to 3.0 MPa or less, damage due to application of an excessive load to the electronic components is prevented. In addition, by making the thermocompression bonding time short, the damage by heat to an electronic component is prevented.

In this way, when the curable composition of this invention is used, the adhesive strength excellent in low temperature, low pressure and a short time can be ensured, and members in an electronic component can be electrically connected.

[Example]

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these. In addition, unless otherwise indicated below, "part" and "%" shall be based on mass.

(Examples 1 to 8 and Comparative Example 1)

I. Preparation of curable composition

Each component was mix|blended and stirred by the compounding ratio (mass ratio) shown in Table 1, and the curable composition of Examples 1-8 and Comparative Example 1 was produced.

II. Evaluation of adhesive strength

II-1. Preparation of test pieces

(1) Rigid substrate (copper substrate)

The curable compositions of Examples 1 to 8 and Comparative Example 1 prepared in I above were coated on a rigid substrate (substrate: FR-4, putt width: 100 μm, pitch width: 0.2 mm, flash Au treatment) on a metal mask (mask thickness) : 80 µm, opening: 15 mm × 1 mm) was applied with a scraper. Next, a flexible substrate (width: 16 mm, base material: polyimide, pat width: 100 µm, pitch width: 0.2 mm, flash Au treatment) was loaded on the rigid substrate in the state in which the curable composition was applied. At the time of this loading, the positions of the putt of the rigid substrate and the putt of the flexible substrate were aligned, and the length of the overlapping surfaces of both substrates was 4 mm. Thus, with respect to the bonding surface of the board|substrates mounted in this way, thermocompression-bonding was performed at 1.5 MPa, 150 degreeC, and 6 second, and the test piece was produced.

(2) silver electrode substrate

The curable composition of Example 4 was patterned on soda-lime glass (thickness 1.1 mm) with silver paste (ECM-100 AF6100 manufactured by Taiyo Ink. Co., Ltd.) on a substrate (silver electrode substrate) (pattern width: 100 µm) , pitch width: 0.2 mm) was applied with a scraper through a metal mask (mask thickness: 80 µm, opening: 15 mm × 1 mm). Next, the flexible substrate (width: 16 mm, base material: polyimide, pat width: 100 micrometers, pitch width: 0.2 mm, flash Au treatment) was loaded with respect to the glass substrate of the state to which the curable composition was apply|coated. At the time of this loading, the positions of the putt of the rigid board and the putt of the flexible board were aligned, and the length of the overlapping surfaces of the two boards was set to 4 mm. Thus, with respect to the bonding surface of the board|substrates mounted in this way, thermocompression-bonding was performed at 1.5 MPa, 150 degreeC, and 6 second, and the test piece was produced.

(3) ITO substrate

The curable composition of Example 4 was placed on an ITO-deposited glass substrate (ITO-based) (PD200 manufactured by Asahi Glass Co., Ltd., ITO thickness 500 Å) with a metal mask (mask thickness: 80 μm, opening: 15 mm × 1 mm) interposed therebetween It was applied with a scraper. Next, the flexible substrate (width: 16 mm, base material: polyimide, pat width: 100 micrometers, pitch width: 0.2 mm, flash Au treatment) was loaded with respect to the glass substrate of the state to which the curable composition was apply|coated. At the time of this loading, the positions of the putt of the rigid board and the putt of the flexible board were aligned, and the length of the overlapping surfaces of the two boards was set to 4 mm. Thus, with respect to the bonding surface of the board|substrates mounted in this way, thermocompression-bonding was performed at 1.5 MPa, 150 degreeC, and 6 second, and the test piece was produced.

(4) aluminum substrate

The curable composition of Example 4 was applied on an aluminum rigid substrate (base: FR-4, aluminum thickness of 25 µm) with a scraper through a metal mask (mask thickness: 80 µm, opening: 15 mm×1 mm). Next, the flexible substrate (width: 16 mm, base material: polyimide, pat width: 100 micrometers, pitch width: 0.2 mm, flash Au treatment) was loaded with respect to the glass substrate of the state to which the curable composition was apply|coated. At the time of this loading, the positions of the putt of the rigid board and the putt of the flexible board were aligned, and the length of the overlapping surfaces of the two boards was set to 4 mm. Thus, with respect to the bonding surface of the board|substrates mounted in this way, thermocompression-bonding was performed at 1.5 MPa, 150 degreeC, and 6 second, and the test piece was produced.

II-2. Determination of adhesive strength

With respect to the produced test piece, according to JIS K 6854-1, the flexible substrate was peeled off in the vertical direction, and adhesive strength was measured. The obtained evaluation result is shown together in Table 1.

Ⅲ. Assessment of continuity

Using the test piece obtained in II-1 above, conduction between the put part of the rigid substrate and the put part of the flexible substrate was confirmed and evaluated by a tester (Digital High Tester 3256, manufactured by Hioki Electronics Co., Ltd.). The evaluation criteria are as follows. The obtained evaluation result is shown together in Table 1.

○: Conduction was confirmed.

x: Conduction was not confirmed.

IV. Evaluation of storage stability (thickening rate)

The viscosity of the curable composition prepared in the above I was measured with an E-type viscometer (corn plate type viscometer TVH-33 manufactured by Toki Sangyo Co., Ltd., measurement temperature 25° C.), and this was taken as the initial viscosity. Then, the curable composition was stored in a 30 degreeC thermostat for 60 hours, and the viscosity after the lapse of 60 hours was similarly measured with the said E-type viscometer.

The thickening rate was calculated by the following formula.

Thickening rate (%) = ((Viscosity after 60 hours (dPa·s)/Initial viscosity (dPa·s))-1) × 100

The obtained evaluation result is shown in Table 1.

The detail of each component described in Table 1 is as follows.

Compound (A-1) having an ethylenically unsaturated bond: 2-hydroxy-3-phenoxypropyl acrylate (Aronix M-5700 manufactured by Toagosei Co., Ltd., molecular weight: 222, Tg: 17°C, viscosity: 1.65 dPa s/25℃)

Compound (A-2) having an ethylenically unsaturated bond: polybutadiene urethane acrylate (BR-45UAS manufactured by Light Chemical Kogyo Co., Ltd., molecular weight: Mw3000, Tg: 222°C, viscosity: 375 dPa·s/25°C)

Organic binder (D-1): polyester resin (byron 500 manufactured by Toyobo Seki Co., Ltd., molecular weight: Mn23000, Tg: 4°C)

Epoxy resin: Bisphenol A epoxy resin (Mitsubishi Chemical Co., Ltd. 828, molecular weight: 370, viscosity: 138 dPa·s/25°C)

Hardening agent: 2-ethyl-4-methylimidazole (Shikoku Chemical Co., Ltd. 2E4MZ, melting|fusing point: 40 degreeC)

Peroxide (B-1): t-hexylperoxyisopropyl monocarbonate, appearance: liquid, half-life temperature for 1 minute: 155.0°C, 10 hours half-life temperature: 95.0°C)

Peroxide (B-2): 1,1-di(t-hexylperoxy)cyclohexane (Perhexa HC manufactured by Nichi Oil Co., Ltd., Appearance: Liquid, 1 minute half-life temperature: 149.2° C., 10 hour half-life temperature: 87.1℃)

Peroxide (B-3): t-butylperoxy-2-ethylhexanoate (perbutyl O manufactured by Nichi Oil Co., Ltd., appearance: liquid, half-life temperature for 1 minute: 134°C, half-life temperature for 10 hours: 72.1°C )

Peroxide (B-4): 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (Nichi Oil Co., Ltd. Perocta O, Form: Liquid, 1 minute half-life temperature: 124.3°C , 10 hours half-life temperature: 65.3°C)

Peroxide (B-5): t-hexylperoxy-2-ethylhexanoate (perhexyl O manufactured by Nichi Oil Co., Ltd., appearance: liquid, half-life temperature for 1 minute: 90.1 ° C., half-life temperature for 10 hours: 69.9 ° C. )

Peroxide (B-6): dibenzoyl peroxide (Nipper BW manufactured by Nichi Oil Co., Ltd., property: powder, half-life temperature for 1 minute: 130°C, half-life temperature for 10 hours: 73.6°C)

Peroxide (B-7): di(4-t-butylcyclohexyl)peroxydicarbonate (Nichi Oil Co., Ltd. peroyl TCP, properties: powder, 1 minute half-life temperature: 92.1°C, 10 hour half-life temperature : 40.8℃)

Solder powder: spherical particles of 42Sn-58Bi composition (average particle diameter (D50): 13.12 μm)

As is clear from the results shown in Table 1, it was confirmed that a low temperature, low pressure and short time conductive adhesion was possible by using a compound having an ethylenically unsaturated bond and a peroxide.

In addition, it was confirmed that the thickening rate decreased and storage stability was improved by using the liquid peroxide.

(Examples 9 to 16 and Comparative Examples 2 to 5)

I. Preparation of curable composition

Each component was mix|blended and stirred by the compounding ratio (mass ratio) shown in Table 2, and the curable composition of Examples 9-16 and Comparative Examples 2-5 was manufactured.

II. Evaluation of adhesive strength

II-1. Preparation of test pieces

(1) Rigid substrate (copper substrate)

In the same manner as in Examples 1 to 8 and Comparative Example 1 described above, the curable compositions of Examples 9 to 16 and Comparative Examples 2 to 5 prepared in I above were applied to a rigid substrate, and test pieces were produced in the same manner.

(2) silver electrode substrate

Similarly to Example 4, the curable composition of Example 9 was apply|coated to the silver electrode board|substrate, and the test piece was produced by similar operation.

(3) ITO substrate

In the same manner as in Example 4, the solder paste of Example 9 was applied to the ITO substrate, and a test piece was produced in the same manner.

(4) aluminum substrate

Similarly to Example 4, the curable composition of Example 9 was apply|coated to the aluminum rigid board|substrate, and the test piece was produced by similar operation.

II-2. Determination of adhesive strength

With respect to the produced test piece, according to JIS K 6854-1, the flexible substrate was peeled off in the vertical direction, and adhesive strength was measured. The evaluation criteria are as follows. The obtained evaluation result is shown together in Table 2.

○: 10N/16mm or more

△: 5N/16mm or more

×: less than 5N/16mm

Ⅲ. About the evaluation of continuity|conductivity and the evaluation of storage stability (thickening rate), the evaluation conditions and evaluation criteria similar to Examples 1-8 and Comparative Example 1 were evaluated.

Table 2 shows the evaluation results.

The detail of each component described in Table 2 is as follows.

(A) a compound having an ethylenically unsaturated bond:

(A-1) 2-hydroxy-3-phenoxypropyl acrylate, manufactured by Toagosei Co., Ltd. "Aronix M 5700"

(A-3) Phenoxyethyl acrylate, "light acrylate PO-A" manufactured by Kyoesha Chemical Co., Ltd.

(A-4) 4-hydroxybutyl acrylate, "4HBA" manufactured by Nippon Chemicals Co., Ltd.

(A-5) Trimethylolpropane EO-modified (n≒1) triacrylate, manufactured by Toagosei Co., Ltd. "Aronix M-350"

(A-6) Trimethylolpropane triacrylate, manufactured by Toagosei Co., Ltd. "Aronix M-309"

(D) organic binders:

(D-2) Phosphorus-containing polyester resin, manufactured by Toyobo Corporation "Byron 337", molecular weight: Mn10000, Tg: 14°C, appearance: solid

(D-3) Alkylacetalized polyvinyl alcohol (about 29 mol% of OH groups, 3 mol% or less of acetyl groups, about 71 mol% of butyralization degree), Sekisui Chemical Co., Ltd. "Srec B BL10" ', molecular weight: 15000, Tg: 59℃, appearance: solid)

(D-4) Methyl methacrylate (MMA)-butyl acrylate (BA) block copolymer, "Kurarit LA2330" manufactured by K.K., molecular weight: 50000, property: solid)

(B) peroxide

(B-4) 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, Nichiyo Oil Co., Ltd. "Perocta O", 1-minute half-life temperature: 124.3°C, 10-hour half-life temperature : 65.3℃, Appearance: Liquid)

(B-7) dibenzoyl peroxide, "Niper BW" manufactured by Nichiyu Corporation, 1 minute half-life temperature: 130° C., 10-hour half-life temperature: 73.6° C., appearance: powder)

(C) conductive powder: (C-1) 42Sn-58Bi [spherical particles of 42Sn-58Bi composition: average particle diameter (D50), 13.12 μm];

(E) thixotropic imparting agent

(E-1) Silica fine particles (specific surface area 170 m ² /g) “Aerosil R974” manufactured by Nippon Aerosil Co., Ltd.

Equivalent weight in organic component (g/eq)*: Number of equivalents of ethylenic double bond in organic component (excluding solvent)

As is clear from the results shown in Table 2, it was confirmed that, in adhesion by the composition of the present invention having an ethylenically unsaturated bond equivalent of 260 or more, conductive adhesion at a low temperature, a low pressure, and a short time was possible, and excellent adhesive strength was obtained.

Moreover, it was confirmed that the thickening rate was small and storage stability became favorable by using a liquid peroxide.

Claims (6)

(A) a compound having an ethylenically unsaturated bond;
(B) a peroxide;
(C) conductive powder;
(D) an organic binder;
The ethylenically unsaturated bond equivalent in the organic component (excluding the solvent when a solvent is included) consisting of (A) the compound having an ethylenically unsaturated bond, (B) peroxide, and (D) an organic binder is 260 or more Curable composition, characterized in that 500 or less. The curable composition according to claim 1, wherein the (B) peroxide is liquid. The curable composition according to claim 1 or 2, wherein the conductive powder (C) is a low-melting-point solder powder having a melting point of 200°C or less. The curable composition according to claim 1 or 2, which is used as a conductive adhesive for electronic components. An electronic component in which members are electrically connected using the curable composition according to claim 1 or 2 . delete