JPH11172147A - Production of electroconductive powder, electroconductive powder and electroconductive paste by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an electroconductive powder useful as an electronic material by which times for separating the electroconductive powder from a solvent containing a lubricant, and for drying the electroconductive powder can be extremely shortened by washing the electroconductive powder with a solvent added with an aluminum-based coupling agent. SOLUTION: An electroconductive powder (e.g. silver powder) is subjected to milling and/or flattening treatment in the presence of a lubricant (e.g. stearic acid), and the lubricant attached to the electroconductive powder is washed with a solvent (e.g. alcoholic solvent) added with an aluminum-based coupling agent (e.g. acetoalkoxyaluminum diisopropionate). The coupling agent of 0.01-10 wt.% is preferably added to the solvent of 99.99-90 wt.%.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は電子材料用として有
用な、導電粉の製造法、該方法により製造された導電粉
及びこれを用いた導電性ペーストに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a conductive powder useful for electronic materials, a conductive powder produced by the method, and a conductive paste using the same.

【０００２】[0002]

【従来の技術】一般に金属粉末の粉砕又はメカニカルア
ロイング処理はボールミルなどで行われており、粉砕又
はメカニカルアロイング処理する際、粉体粉末冶金協会
発行、「粉体及び粉末冶金」１９９２年、第３９巻第７
号、第５５９〜５６３頁に記載されているようにステア
リン酸などの滑剤が用いられている。電気回路形成用の
導電性ペーストに用いられる導電粉も、任意の大きさ、
形状にするため湿式又は乾式法で粉砕され、特に乾式法
で粉砕する場合、ステアリン酸などの滑剤を添加して粉
砕すると導電粉の凝集や粉砕装置への付着を防止するこ
とができる。2. Description of the Related Art Generally, pulverization or mechanical alloying of metal powder is performed by a ball mill or the like. When pulverization or mechanical alloying is performed, "Powder and Powder Metallurgy" published by the Japan Society of Powder and Powder Metallurgy, 1992, Volume 39 Number 7
No. 559-563, a lubricant such as stearic acid is used. The conductive powder used for the conductive paste for forming the electric circuit is also of any size,
The powder is pulverized by a wet or dry method in order to form the powder. In particular, in the case of pulverization by a dry method, when a lubricant such as stearic acid is added and pulverized, aggregation of the conductive powder and adhesion to the pulverizer can be prevented.

【０００３】しかしながら、滑剤を含んだ導電粉をその
まま導電性ペーストに使用し、金属表面等に塗布、乾
燥、硬化させると密着強度が著しく低下し、はく離など
が生じ易くなる。アルコール、アセトン、酢酸エチル等
の溶媒で導電粉に付着した滑剤を洗浄して取り除けば、
密着強度の低下を防止することができる。上記の溶媒で
洗浄する場合、導電粉を溶媒に入れ撹拌などの処置を行
い静置した後、滑剤を含む溶媒分を乾燥させれば滑剤を
取り除いた導電粉が得られるが、そのまま乾燥すると溶
媒の揮発に時間がかかる。導電粉と溶媒を分離した後、
滑剤を含む溶媒を傾斜して除去するか、スポイトなどを
用いて溶媒を吸い取った後、乾燥すれば乾燥時間が大き
く短縮されるがこの方法においても、溶媒と導電粉の分
離に数十時間という時間がかかるという欠点があった。However, when a conductive powder containing a lubricant is used as it is in a conductive paste and applied to a metal surface or the like, dried, and cured, the adhesion strength is remarkably reduced, and peeling is liable to occur. If the lubricant attached to the conductive powder is removed by washing with a solvent such as alcohol, acetone, ethyl acetate, etc.,
A decrease in adhesion strength can be prevented. In the case of washing with the above solvent, the conductive powder is removed from the solvent by drying the solvent containing the lubricant after the conductive powder is placed in the solvent and subjected to a treatment such as stirring. It takes time to evaporate. After separating conductive powder and solvent,
The solvent containing the lubricant is removed at an angle or the solvent is sucked off using a dropper, etc., and the drying time is greatly reduced if it is dried.However, in this method, it takes several tens of hours to separate the solvent and the conductive powder. There was a disadvantage that it took time.

【０００４】[0004]

【発明が解決しようとする課題】請求項１記載の発明
は、導電粉と滑剤を含む溶媒の分離時間及び乾燥時間を
大幅に短縮できる導電粉の製造法を提供するものであ
る。請求項２記載の発明は、導電粉と滑剤を含む溶媒の
分離時間及び乾燥時間を大幅に短縮できる導電粉を提供
するものである。請求項３記載の発明は、請求項２記載
の導電粉を用いた密着強度の高い導電性ペーストを提供
するものである。SUMMARY OF THE INVENTION The first aspect of the present invention provides a method for producing a conductive powder capable of greatly shortening the time required for separating and drying the solvent containing the conductive powder and the lubricant. The second aspect of the present invention provides a conductive powder capable of greatly reducing the time required for separating the conductive powder and the solvent containing the lubricant and the drying time. According to a third aspect of the present invention, there is provided a conductive paste having high adhesion strength using the conductive powder according to the second aspect.

【０００５】[0005]

【課題を解決するための手段】本発明は、導電粉を滑剤
の存在下に粉砕及び／又は扁平化処理した後、導電粉に
付着した滑剤をアルミニウム系カップリング剤を添加し
た溶媒で洗浄することを特徴とする導電粉の製造法に関
する。また、本発明は、上記の方法により製造された導
電粉に関する。さらに、本発明は、上記の導電粉、結合
剤及び溶剤を含有してなる導電性ペーストに関する。SUMMARY OF THE INVENTION According to the present invention, after a conductive powder is ground and / or flattened in the presence of a lubricant, the lubricant attached to the conductive powder is washed with a solvent containing an aluminum-based coupling agent. And a method for producing a conductive powder. Further, the present invention relates to a conductive powder produced by the above method. Further, the present invention relates to a conductive paste containing the above-mentioned conductive powder, binder and solvent.

【０００６】[0006]

【発明の実施の形態】本発明に用いられる導電粉は、銀
粉、銅粉、ニッケル粉、銀めっき銅粉、ニッケルめっき
銅粉等の各種金属粉やカーボン粉を用いることができ
る。滑剤としては、ステアリン酸、パルミチン酸等の飽
和脂肪酸、各種ワックスなどそれぞれの粉砕装置及び粉
砕条件、扁平化装置及び扁平化条件に適したものが用い
られる。滑剤は導電粉９８．０〜９９．９０５重量％に
対し、０．０９５〜２．０重量％使用される。BEST MODE FOR CARRYING OUT THE INVENTION As the conductive powder used in the present invention, various metal powders such as silver powder, copper powder, nickel powder, silver-plated copper powder, nickel-plated copper powder and carbon powder can be used. As the lubricant, those suitable for the respective crushing devices and crushing conditions, the flattening device and the flattening conditions, such as saturated fatty acids such as stearic acid and palmitic acid, and various waxes are used. The lubricant is used in an amount of 0.095 to 2.0% by weight based on 98.0 to 99.905% by weight of the conductive powder.

【０００７】またアルミニウム系カップリング剤として
は、アセトアルコキシアルミニウムジイソプロピレート
などが用いられる。溶媒としては、アルコール系溶媒、
酢酸エチル、アセトン等導電粉に付着した滑剤の洗浄に
適した溶媒を選択して用いればよい。[0007] As the aluminum-based coupling agent, acetoalkoxyaluminum diisopropylate and the like are used. As the solvent, an alcohol solvent,
A solvent suitable for cleaning the lubricant attached to the conductive powder, such as ethyl acetate and acetone, may be selected and used.

【０００８】アルミニウム系カップリング剤の添加量
は、溶媒９９．９９〜９０重量％に対し、アルミニウム
系カップリング剤を０．０１〜１０重量％添加すること
が好ましく、溶媒９９．９５〜９５重量％に対し、アル
ミニウム系カップリング剤を０．０５〜５重量％添加す
ることがより好ましく、溶媒９９．９〜９９重量％に対
し、アルミニウム系カップリング剤を０．１〜１重量％
添加することがさらに好ましい。アルミニウム系カップ
リング剤の添加量が０．０１重量％未満では導電粉との
分離時間が長くかかる傾向があり、１０重量％を越える
と滑剤の洗浄が不十分となる傾向があり、さらにはコス
トが高くなる傾向がある。The amount of the aluminum-based coupling agent added is preferably 0.01 to 10% by weight of the aluminum-based coupling agent with respect to 99.99 to 90% by weight of the solvent, and 99.95 to 95% by weight of the solvent. %, More preferably 0.05 to 5% by weight of an aluminum coupling agent, and 0.1 to 1% by weight of an aluminum coupling agent to 99.9 to 99% by weight of a solvent.
More preferably, it is added. If the addition amount of the aluminum-based coupling agent is less than 0.01% by weight, the separation time from the conductive powder tends to be long, and if it exceeds 10% by weight, the cleaning of the lubricant tends to be insufficient, and furthermore, the cost is increased. Tend to be higher.

【０００９】導電粉を滑剤の存在下に粉砕及び／又は扁
平化処理する方法については特に制限はないが、例えば
らいかい機、ボールミル、振動ミル等の方法で粉砕及び
／又は扁平化処理することができる。滑剤を添加して扁
平化処理して得られる扁平状導電粉としては、形状とし
てほぼ平担で微細な小片からなる導電粉で、例えばりん
片状導電粉がある。扁平状導電粉としては、アスペクト
比が３〜２０及び長径の平均粒径が５〜３０μｍの導電
粉を用いることが好ましく、アスペクト比が５〜１５及
び長径の平均粒径が７〜２０μｍの導電粉を用いること
がさらに好ましい。なお上記でいう平均粒径は、レーザ
ー散乱型粒度分布測定装置により測定することができ
る。本発明においては、前記装置としてマスターサイザ
ー（マルバン社製）を用いて測定した。The method of pulverizing and / or flattening the conductive powder in the presence of a lubricant is not particularly limited. For example, pulverizing and / or flattening by a method such as a milling machine, a ball mill, a vibration mill, or the like. Can be. The flat conductive powder obtained by adding a lubricant and flattening is a conductive powder composed of fine particles that are almost flat in shape and are, for example, flaky conductive powder. As the flat conductive powder, it is preferable to use a conductive powder having an aspect ratio of 3 to 20 and a long diameter having an average particle diameter of 5 to 30 μm, and a conductive powder having an aspect ratio of 5 to 15 and a long diameter having an average particle diameter of 7 to 20 μm. More preferably, powder is used. The average particle size mentioned above can be measured by a laser scattering type particle size distribution measuring device. In the present invention, the measurement was performed using a master sizer (manufactured by Malvern) as the device.

【００１０】本発明における、導電粉のアスペクト比と
は、導電粉の粒子の長径と短径の比率（長径／短径）を
いう。本発明においては、粘度の低い硬化性樹脂中に導
電粉の粒子をよく混合し、静置して粒子を沈降させると
ともにそのまま樹脂を硬化させ、得られた硬化物を垂直
方向に切断し、その切断面に現れる粒子の形状を電子顕
微鏡で拡大して観察し、少なくとも１００個の粒子につ
いて一つ一つの粒子の長径／短径を求め、それらの平均
値をもってアスペクト比とする。ここで、短径とは、前
記切断面に現れる粒子について、その粒子の外側に接す
る二つの平行線の組合せを粒子を挾むように選択し、こ
れらの組合せのうち最短間隔になる二つの平行線の距離
である。一方、長径とは、前記短径を決する平行線に直
角方向の二つの平行線であって、粒子の外側に接する二
つの平行線の組合せのうち、最長間隔になる二つの平行
線の距離である。これらの四つの線で形成される長方形
は、粒子がちょうどその中に納まる大きさとなる。な
お、本発明において行った具体的方法については後述す
る。In the present invention, the aspect ratio of the conductive powder refers to the ratio of the major axis to the minor axis (major axis / minor axis) of the conductive powder particles. In the present invention, the particles of the conductive powder are mixed well in the curable resin having a low viscosity, and the resin is cured while allowing the particles to settle by standing, and the obtained cured product is cut in the vertical direction. The shape of the particles appearing on the cut surface is observed under magnification with an electron microscope, and the major axis / minor axis of each particle is obtained for at least 100 particles, and the average value thereof is defined as the aspect ratio. Here, the minor axis is defined as a combination of two parallel lines contacting the outside of the particle so as to sandwich the particle. Distance. On the other hand, the major axis is two parallel lines perpendicular to the parallel line that determines the minor axis, and of the combination of the two parallel lines tangent to the outside of the particle, the distance between the two parallel lines at the longest interval. is there. The rectangle formed by these four lines is sized to fit the particle exactly inside it. The specific method used in the present invention will be described later.

【００１１】導電ペーストは、これらの導電粉、結合剤
及び溶剤を含有してなるものである。この導電ペースト
において導電粉と結合剤の含有量は、導電ペーストの固
形分に対して導電性及び接着性の点で導電粉が７０〜９
３重量％及び結合剤が７〜３０重量％の範囲が好まし
く、導電粉７５〜９０重量％及び結合剤が１０〜２５重
量％の範囲がより好ましく、導電粉７８〜８８重量％及
び結合剤が１２〜２２重量％の範囲がさらに好ましい。
溶剤は、導電ペーストに対して５〜４５重量％の範囲が
好ましく、７〜４０重量％の範囲がより好ましく、１０
〜３５重量％の範囲がさらに好ましい。The conductive paste contains these conductive powder, binder and solvent. In this conductive paste, the content of the conductive powder and the binder is 70 to 9 in terms of conductivity and adhesiveness with respect to the solid content of the conductive paste.
The range of 3% by weight and the binder is preferably in the range of 7 to 30% by weight, the range of 75 to 90% by weight of the conductive powder and the range of 10 to 25% by weight of the binder is more preferable, and the range of 78 to 88% by weight of the conductive powder and the binder is more preferable. A range from 12 to 22% by weight is more preferred.
The solvent is preferably in a range of 5 to 45% by weight, more preferably in a range of 7 to 40% by weight, based on the conductive paste.
More preferably, it is in the range of -35 wt%.

【００１２】結合剤としては、フェノール樹脂、エポキ
シ樹脂等の熱硬化性樹脂を用いることが好ましい。フェ
ノール樹脂としては、レゾール型フェノール樹脂やノボ
ラック型フェノール樹脂が挙げられる。必要に応じてこ
れらのフェノール樹脂を変成して用いてもよい。ノボラ
ック型フェノール樹脂を使用する場合はヘキサメチレン
テトラミン等の硬化剤を用いる。これらの樹脂は単独で
用いてもよく、２種類以上を併用してもよい。またエポ
キシ樹脂としては、ビスフェノール型エポキシ樹脂、フ
ェノールノボラック型エポキシ樹脂、エポキシ化ポリブ
タジエン、脂環式エポキシ樹脂、可とう性エポキシ樹
脂、多官能エポキシ樹脂等が挙げられる。これらの樹脂
は単独で用いてもよく、２種類以上を併用してもよい。It is preferable to use a thermosetting resin such as a phenol resin and an epoxy resin as the binder. Examples of the phenol resin include a resol type phenol resin and a novolak type phenol resin. If necessary, these phenolic resins may be modified and used. When a novolak-type phenol resin is used, a curing agent such as hexamethylenetetramine is used. These resins may be used alone or in combination of two or more. Examples of the epoxy resin include a bisphenol-type epoxy resin, a phenol novolak-type epoxy resin, an epoxidized polybutadiene, an alicyclic epoxy resin, a flexible epoxy resin, and a polyfunctional epoxy resin. These resins may be used alone or in combination of two or more.

【００１３】溶剤としては、ブチルセロソルブ、エチル
カルビトール、ブチルエチルカルビトール、エチルセロ
ソルブ、エチルセロソルブアセテート、ブチルセロソル
ブアセテート、エチルカルビトールアセテート、ブチル
カルビトールアセテート等を用いることが好ましい。本
発明の導電性ペーストは、上記の導電粉、結合剤及び溶
剤と共にらいかい機、ニーダー等に入れて混合して得る
ことができる。As the solvent, butyl cellosolve, ethyl carbitol, butyl ethyl carbitol, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve acetate, ethyl carbitol acetate, butyl carbitol acetate and the like are preferably used. The conductive paste of the present invention can be obtained by putting it in a grinder, kneader or the like together with the above-mentioned conductive powder, binder and solvent and mixing them.

【００１４】[0014]

【実施例】以下本発明の実施例を説明する。なお本発明
は以下の実施例に制限されるものではない。 実施例１ 平均粒径が５μｍの略球形銀粉（徳力化学製、商品名Ｓ
ＦＲ−Ａｇ）１００ｇ及びステアリン酸を０．５ｇ配合
し、直径が２mm（φ）のジルコニアボールと共に遊星型
ボールミルで３０分間回転させ、扁平化処理した。該扁
平化処理銀粉及びアルミニウム系カップリング剤として
アセトアルコキシアルミニウムジイソプロピレートをエ
タノール９９重量％に対して１重量％添加したエタノー
ル溶液２００ｇをビーカーに入れ十分に撹拌（洗浄）し
た。撹拌後、銀粉が沈殿し、溶媒と銀粉が完全に分離す
る時間を計測したところ５分であった。Embodiments of the present invention will be described below. The present invention is not limited to the following embodiments. Example 1 Substantially spherical silver powder having an average particle size of 5 μm (manufactured by Tokurika Chemical, trade name S
100 g of FR-Ag) and 0.5 g of stearic acid were blended, and the mixture was rotated with a zirconia ball having a diameter of 2 mm (φ) in a planetary ball mill for 30 minutes to be flattened. The flattened silver powder and 200 g of an ethanol solution containing 1% by weight of acetoalkoxyaluminum diisopropylate as an aluminum-based coupling agent with respect to 99% by weight of ethanol were put into a beaker and sufficiently stirred (washed). After the stirring, the silver powder was precipitated, and the time required for completely separating the solvent and the silver powder was measured to be 5 minutes.

【００１５】次に実施例１のアルミニウム系カップリン
グ剤を添加して洗浄した銀スラリーの溶媒を乾燥機で乾
燥し、アスペクト比が平均１０及び長径の平均粒径が
８．９μｍの扁平状銀粉を得た。次いで扁平状銀粉１０
０重量部、レゾール型フェノール樹脂（日立化成工業
(株)製、商品名ＶＰ−１３Ｎの濃縮品、固形分９５重量
％）１５重量部及びブチルセロソルブ２０重量部をらい
かい機で３０分間混合して均一に分散させ、導電性ペー
ストを得た。なお扁平状銀粉と結合剤の配合割合は、導
電ペーストの固形分に対して扁平状銀粉が８７．０重量
％及び結合剤が１３．０重量％であった。Next, the solvent of the silver slurry washed with the addition of the aluminum-based coupling agent of Example 1 was dried with a drier, and the flat silver powder having an average aspect ratio of 10 and a long diameter having an average particle size of 8.9 μm was used. I got Then, the flat silver powder 10
0 parts by weight, resol type phenol resin (Hitachi Chemical Industries
15 parts by weight of a concentrated product of VP-13N (trade name, manufactured by Co., Ltd., solid content: 95% by weight) and 20 parts by weight of butyl cellosolve were mixed by a rapier for 30 minutes and uniformly dispersed to obtain a conductive paste. The mixing ratio of the flat silver powder and the binder was 87.0% by weight of the flat silver powder and 13.0% by weight of the binder based on the solid content of the conductive paste.

【００１６】次に上記で得た導電性ペーストを厚さが
１．６mmの紙フェノール銅張積層板（日立化成工業(株)
製、商品名ＭＣＬ−４３７Ｆ（ＳＲＤ））の銅箔上に塗
布し、大気中で７０℃で２時間、さらに１５０℃で３０
分間の条件で加熱硬化して厚さが８０μｍの導電膜を形
成した。次いで導電膜上にカッターで１mm間隔で縦横そ
れぞれ１１本ずつ格子状に切り込みを入れ、升目上にセ
ロハンテープを十分に密着させた後、セロハンテープを
急激に引き剥がした。その結果、はく離はまったく見ら
れなかった。Next, the conductive paste obtained above was applied to a paper phenol copper-clad laminate having a thickness of 1.6 mm (Hitachi Chemical Industry Co., Ltd.)
Co., Ltd., trade name: MCL-437F (SRD)), applied in air at 70 ° C. for 2 hours and further at 150 ° C. for 30 hours.
Then, the film was cured by heating under the conditions of minutes, thereby forming a conductive film having a thickness of 80 μm. Next, 11 slits each of which were arranged vertically and horizontally at 1 mm intervals were cut on the conductive film in a grid pattern, and the cellophane tape was sufficiently adhered to the cells, and then the cellophane tape was rapidly peeled off. As a result, no peeling was observed.

【００１７】また上記で得た導電性ぺーストを直径が
０．５mm（φ）のスルーホールを形成した上記と同様の
紙フェノール銅張積層板上に２００メッシュのスクリー
ンを通して印刷してスルーホールに充てんしたものを、
大気中で７０℃で２時間、さらに１５０℃で３０分間の
条件で加熱硬化して配線板を得た。得られた配線板の抵
抗を測定した結果、２０．７ｍΩ／穴であった。The conductive paste obtained above is printed through a 200-mesh screen on the same paper phenol copper-clad laminate having a through-hole having a diameter of 0.5 mm (φ) to form a through-hole. Filled,
The circuit board was obtained by heating and curing in air at 70 ° C. for 2 hours and further at 150 ° C. for 30 minutes. As a result of measuring the resistance of the obtained wiring board, it was 20.7 mΩ / hole.

【００１８】なお、本実施例におけるアスペクト比の具
体的測定法を以下に示す。低粘度のエポキシ樹脂（ビュ
ーラー社製）の主剤（No.２０−８１３０）８ｇと硬化
剤（No.２０−８１３２）２ｇを混合し、ここへ導電粉
２ｇを混合して良く分散させ、そのまま３０℃で真空脱
泡した後、６〜８時間３０℃で静置して粒子を沈降させ
硬化させた。その後、得られた硬化物を垂直方向に切断
し、切断面を電子顕微鏡で２０００倍に拡大して切断面
に現われた１００個の粒子について長径／短径を求め、
それらの平均値をもって、アスペクト比とした。The specific method of measuring the aspect ratio in the present embodiment will be described below. 8 g of a base material (No. 20-8130) of a low-viscosity epoxy resin (manufactured by Buehler Co.) and 2 g of a curing agent (No. 20-8132) are mixed, and 2 g of conductive powder is mixed and dispersed well, and the mixture is left as it is. After degassing in vacuo at ℃, the particles were allowed to stand at 30 ℃ for 6 to 8 hours to settle and harden the particles. Thereafter, the obtained cured product was cut in the vertical direction, the cut surface was magnified 2000 times with an electron microscope, and the long diameter / short diameter was determined for 100 particles that appeared on the cut surface,
The average value was used as the aspect ratio.

【００１９】比較例１ アルミニウム系カップリング剤を添加しない以外は実施
例１と同様の工程を経て撹拌（洗浄）した。撹拌後、銀
粉が沈殿し、溶媒と銀粉が完全に分離する時間を計測し
たところ２２時間かかった。以下実施例１と同様の工程
を経て導電性ペーストを得、さらに紙フェノール銅張積
層板上の銅箔上に厚さが８０μｍの導電膜を形成した。
次いで実施例１と同様に導電膜上にカッターで１mm間隔
で縦横それぞれ１１本ずつ格子状に切り込みを入れたと
ころ、この時点で導電膜のはく離が生じた。なお実施例
１と同様の工程を経て配線板を得、抵抗を測定した結果
２２．５ｍΩ／穴であった。Comparative Example 1 The procedure of Example 1 was repeated except that no aluminum-based coupling agent was added, followed by stirring (washing). After stirring, the silver powder was precipitated, and it took 22 hours to measure the time required for completely separating the solvent and the silver powder. Hereinafter, a conductive paste was obtained through the same steps as in Example 1, and a conductive film having a thickness of 80 μm was formed on the copper foil on the paper phenol copper-clad laminate.
Next, in the same manner as in Example 1, 11 cuts were formed in a grid pattern on the conductive film at an interval of 1 mm each in a vertical and horizontal direction, and peeling of the conductive film occurred at this time. A wiring board was obtained through the same steps as in Example 1, and the resistance was measured. The result was 22.5 mΩ / hole.

【００２０】実施例２ 平均粒径が５μｍの略球形銅粉（日本アトマイズ加工
製、商品名ＳＦ−Ｃｕ）に対して置換めっき法で銀を１
５重量％被覆した銀めっき銅粉１００ｇ及びパルミチン
酸を０．５ｇ配合し、実施例１と同様の工程を経て扁平
化処理した。該扁平化処理銀めっき銅粉及びアルミニウ
ム系カップリング剤としてアセトアルコキシアルミニウ
ムジイソプロピレートを酢酸エチル９９．５重量％に対
して０．５重量％添加した酢酸エチル溶液２００ｇをビ
ーカーに入れ十分に撹拌（洗浄）した。撹拌後、銀粉が
沈殿し、溶媒と銀めっき銅粉が完全に分離する時間を計
測したところ６分３０秒であった。Example 2 Silver was added to a substantially spherical copper powder (manufactured by Nippon Atomize, trade name SF-Cu) having an average particle size of 5 μm by displacement plating.
100 g of silver-plated copper powder coated with 5% by weight and 0.5 g of palmitic acid were blended and flattened through the same steps as in Example 1. The flattened silver-plated copper powder and 200 g of an ethyl acetate solution containing 0.5% by weight of acetoalkoxyaluminum diisopropylate as an aluminum-based coupling agent with respect to 99.5% by weight of ethyl acetate were put into a beaker and sufficiently stirred. (Washed). After the stirring, the silver powder was precipitated, and the time required for completely separating the solvent and the silver-plated copper powder was measured, and it was 6 minutes and 30 seconds.

【００２１】次に実施例２のアルミニウム系カップリン
グ剤を添加して洗浄した銀めっき銅スラリーの溶媒を乾
燥機で乾燥し、アスペクト比が平均で８．６及び長径の
平均粒径が７．５μｍの扁平状銀めっき銅粉を得た。以
下実施例１と同様の工程を経て導電性ペーストと配線板
を得た。なお扁平状銀めっき銅粉と結合剤の配合割合
は、導電ペーストの固形分に対して扁平状銀めっき銅粉
が８７．０重量％及び結合剤が１３．０重量％であっ
た。実施例１と同様の方法ではく離試験を行った結果、
はく離はまったく見られなかった。また得られた配線板
の抵抗を測定した結果２２．３ｍΩ／穴であった。Next, the solvent of the silver-plated copper slurry washed by adding the aluminum-based coupling agent of Example 2 was dried by a drier, and the average aspect ratio was 8.6 and the average particle diameter of the major axis was 7. 5 μm flat silver-plated copper powder was obtained. Thereafter, through the same steps as in Example 1, a conductive paste and a wiring board were obtained. The mixing ratio of the flat silver-plated copper powder and the binder was 87.0% by weight of the flat silver-plated copper powder and 13.0% by weight of the binder based on the solid content of the conductive paste. As a result of performing a peeling test in the same manner as in Example 1,
No peeling was seen. Also, the resistance of the obtained wiring board was measured, and the result was 22.3 mΩ / hole.

【００２２】比較例２ アルミニウム系カップリング剤を添加しない以外は実施
例２と同様の工程を経て撹拌（洗浄）した。撹拌後、銀
めっき銅粉が沈殿し、溶媒と銀めっき銅粉が完全に分離
する時間を計測したところ４０時間３０分かかった。以
下実施例１と同様の工程を経て導電性ペーストを得、さ
らに紙フェノール銅張積層板上の銅箔上に厚さが８０μ
ｍの導電膜を形成した。次いで実施例１と同様に導電膜
上にカッターで１mm間隔で縦横それぞれ１１本ずつ格子
状に切り込みを入れたところ、この時点で導電膜のはく
離が生じた。なお実施例１と同様の工程を経て配線板を
得、抵抗を測定した結果２３．３ｍΩ／穴であった。Comparative Example 2 The procedure of Example 2 was repeated except that the aluminum-based coupling agent was not added, followed by stirring (washing). After the stirring, the silver-plated copper powder precipitated, and it took 40 hours and 30 minutes when the time required for completely separating the solvent and the silver-plated copper powder was measured. Thereafter, a conductive paste was obtained through the same steps as in Example 1, and the thickness was 80 μm on a copper foil on a paper phenol copper-clad laminate.
m of the conductive film was formed. Next, in the same manner as in Example 1, 11 cuts were formed in a grid pattern on the conductive film at an interval of 1 mm each in a vertical and horizontal direction, and peeling of the conductive film occurred at this time. A wiring board was obtained through the same steps as in Example 1, and the resistance was measured. The result was 23.3 mΩ / hole.

【００２３】[0023]

【発明の効果】請求項１記載の方法により得られる導電
粉は、滑剤を溶解した溶媒の分離時間及び乾燥時間を大
幅に短縮することができる。請求項２記載の導電粉は、
滑剤を溶解した溶媒の分離時間及び乾燥時間を大幅に短
縮することができる。請求項３記載の導電性ペースト
は、密着強度が高く、スルーホール抵抗についても何ら
問題の生じない導電性ペーストである。According to the conductive powder obtained by the method of the first aspect, the time required for separating and drying the solvent in which the lubricant is dissolved can be greatly reduced. The conductive powder according to claim 2,
The separation time and drying time of the solvent in which the lubricant is dissolved can be greatly reduced. The conductive paste according to the third aspect is a conductive paste having a high adhesion strength and having no problem with through-hole resistance.

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】 導電粉を滑剤の存在下に粉砕及び／又は
扁平化処理した後、導電粉に付着した滑剤をアルミニウ
ム系カップリング剤を添加した溶媒で洗浄することを特
徴とする導電粉の製造法。The method of claim 1, wherein the conductive powder is ground and / or flattened in the presence of a lubricant, and then the lubricant attached to the conductive powder is washed with a solvent to which an aluminum-based coupling agent is added. Manufacturing method. 【請求項２】 請求項１記載の製造法により製造された
導電粉。2. A conductive powder produced by the production method according to claim 1. 【請求項３】 請求項２記載の導電粉、結合剤及び溶剤
を含有してなる導電性ペースト。3. A conductive paste comprising the conductive powder according to claim 2, a binder and a solvent.