JP3746475B2

JP3746475B2 - Manufacturing method of multilayer electronic components

Info

Publication number: JP3746475B2
Application number: JP2002249810A
Authority: JP
Inventors: 進小野
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2002-08-28
Filing date: 2002-08-28
Publication date: 2006-02-15
Anticipated expiration: 2022-08-28
Also published as: JP2004087992A

Description

【０００１】
【発明の属する技術分野】
本発明は、積層型電子部品の製法に関し、特にセラミックスと内部電極とが交互に積層された素子本体の対向する側面に、内部電極端が露出する凹溝を交互に形成し、凹溝が形成された側面に、内部電極と交互に接続する外部電極が形成された積層型電子部品の製法に関するものである。
【０００２】
【従来技術】
従来、積層型電子部品の製法として、特開平６−１５１９９９号公報に記載されるようなものが知られている。
【０００３】
この公報に開示された積層型電子部品は、先ず、内部電極パターンが一対のグリーンシートで挟持された複数のシート積層体に、電極材料が充填される電極用貫通孔と絶縁材料が充填される絶縁用貫通孔を形成し、電極用貫通孔にＡｇ−Ｐｄのスラリーを、絶縁用貫通孔にはガラス−アルミナ系セラミックスのスラリーを充填し、この後、上下のシート積層体において、電極用貫通孔と絶縁用貫通孔が重なるようにシート積層体を交互に位置をずらして積層し、この積層体を焼成した後、貫通孔で切断して、側面に電極材料と絶縁材料が交互に表出した素子本体を得る。
【０００４】
この後、電極材料と絶縁材料が交互に表出した素子本体の側面に、Ａｇペーストを塗布して焼き付けるか、導電性接着剤を塗布してキュア処理することで外部電極を形成し、積層型電子部品を作製していた。
【０００５】
このような積層型電子部品では、内部電極パターンの端部に、素子本体の側面に形成された電極材料が接続され、この電極材料の素子本体側面に占める面積割合を大きくできるため、塗布して形成した外部電極の素子本体側面への付着強度をある程度向上できる。
【０００６】
【発明が解決しようとする課題】
しかしながら、上記公報に記載された積層型電子部品では、外部電極が形成される素子本体側面が平坦であったため、Ａｇペーストを塗布して焼き付けるか、導電性接着剤を塗布してキュア処理して形成した外部電極の付着強度が未だ低いという問題があった。
【０００７】
また、凹溝内にガラス−アルミナ系セラミックスが充填され、内部電極端と外部電極が絶縁されていたため、素子本体の伸縮により凹溝内のセラミックスにクラックが発生し、本来絶縁されるべき内部電極と外部電極との間でショートが発生するという問題があった。
【０００８】
本発明は、寸法通りの凹溝を一挙にかつ確実に形成するとともに、素子本体に対する外部電極の付着強度を著しく向上でき、内部電極と外部電極との間のショートを防止できる積層型電子部品の製法を提供することを目的とする。
【０００９】
【課題を解決するための手段】
本発明の積層型電子部品の製法は、複数のセラミックグリーンシートと複数の内部電極パターンを交互に積層してなる素子本体成形体を作製する工程と、該素子本体成形体の対向する側面に、前記内部電極パターンの端部を露出させ、かつ該内部電極パターンの一層おきに凹溝を形成する工程と、前記素子本体成形体を熱処理して素子本体を作製する工程と、を具備する積層型電子部品の製法であって、
前記素子本体成形体の前記凹溝に、前記熱処理により分解する飛散物質を充填する工程と、隣り合う前記凹溝間の前記素子本体成形体の側面に、金属とガラスを含有する導電物質からなる導電膜を形成する工程と、前記熱処理により、前記導電膜が前記素子本体の有する内部電極と拡散接合し、かつ根元部が前記ガラスに埋設される突起状の導電性端子となる工程と、該導電性端子に外部電極を接合する工程と、を含むことを特徴とする。
【００１０】
前記凹溝に前記飛散物質を充填する工程は、前記内部電極パターンを一対の前記セラミックグリーンシートで挟持してなるシート積層体を作製し、該シート積層体の表面に前記飛散物質からなるシートを積層し、前記シート積層体を打ち抜き加工して凹溝用貫通孔を形成するとともに、該凹溝用貫通孔に前記飛散物質を充填し、前記シート積層体を複数積層させて前記素子本体成形体を作製し、前記飛散物質が充填された前記凹溝用貫通孔を、前記シート積層体の積層方向で切断することを特徴とする。
【００１１】
前記導電物質からなる導電膜を形成する工程は、前記内部電極パターンを一対の前記セラミックグリーンシートで挟持してなるシート積層体を作製し、該シート積層体の表面に前記シート積層体の表面に金属とガラスを含有する導電物質シートを積層し、前記シート積層体を打ち抜き加工して端子形成用貫通孔を形成するとともに、該端子形成用貫通孔に導電物質を充填し、前記シート積層体を複数積層させて前記素子本体成形体を作製し、前記導電物質が充填された前記端子形成用貫通孔を、前記素子本体成形体の積層方向で切断することを特徴とする。
【００１２】
本発明の積層型電子部品では、従来のダイシングなどにより一つ一つ溝加工をすることなく、凹溝を一挙に形成することができ、加工時間を短縮でき、製造工程を簡略化できる。また、対向する側面に、内部電極パターン端が露出し、熱処理により分解する飛散物質が充填された凹溝を、前記内部電極パターン一層おきに交互に形成し、かつ凹溝間の側面に金属とガラスを含有する導電膜を形成してなる素子本体成形体を、簡単な工程で容易に形成できる。
【００１３】
さらに、脱バイ〜焼成（熱処理）工程後には、凹溝間の素子本体側面に露出した内部電極端部に、根元部がガラスに埋設され、かつ内部電極と拡散接合した突起状の導電性端子が形成され、これにより、内部電極の端部に導電性端子を強固に接合できるとともに、凹溝内に絶縁性樹脂を充填することができ、素子本体の伸縮によってもクラックが発生せず、内部電極と外部電極との間でのショートを防止できる。
【００１４】
さらにまた、導電性端子が形成された素子本体の側面に、導電性端子の先端部に板状導電部材からなる外部電極を接合して外部電極を形成したり、導電性端子を導電性樹脂からなる外部電極中に埋設して外部電極を形成するため、素子本体に対する外部電極の付着強度を向上できる。
【００１５】
【発明の実施の形態】
図１乃至図８は本発明の積層型電子部品の製法を説明するための工程図を示すもので、先ず、チタン酸ジルコン酸鉛Ｐｂ（Ｚｒ，Ｔｉ）Ｏ₃などの圧電体セラミックスの仮焼粉末と、アクリル樹脂や、ブチラール樹脂などの有機高分子からなる有機バインダーと、可塑剤とを混合したスラリーを作製し、例えばスリップキャステイング法により、厚み５０〜２５０μｍのセラミックグリーンシートを作製する。
【００１６】
このグリーンシートを所定の寸法に打ち抜いた後、図１（ａ）に示すようにグリーンシート１の片面に、内部電極となる銀−パラジウムを主成分とする導電性ペーストをスクリーン印刷法により１〜１０μｍの厚みに印刷し、乾燥させて内部電極パターン３を形成する。
【００１７】
この後、図１（ｂ）に示すように、内部電極パターン３上に、作製したグリーンシート５を、内部電極パターン３を挟むように重ね、加圧してシート積層体７を作製する。尚、図１（ａ）のように、広いグリーンシート１の中央部に導電性ペーストを塗布し、この導電性ペーストを覆うようにグリーンシート５を積層し、これをカットして、図１（ｂ）に示すようなシート積層体７を作製する。このようなシート積層体７を多数作製する。
【００１８】
次に打ち抜き装置を用いて、図２に示すように、複数のシート積層体７にそれぞれ多数の凹溝用貫通孔９ａ及び端子形成用貫通孔９ｂを規則的に整列した状態で形成する。これらの凹溝用貫通孔９ａは、凹溝の大きさによって寸法は異なってくるが、例えば幅２ｍｍ、長さ１０ｍｍ程度の大きさの長方形形状とする。また、端子形成用貫通孔９ｂは、例えば幅０．６ｍｍ、長さ１０ｍｍ程度の大きさの長方形形状とする。即ち、素子本体を作製した場合に、凹溝用貫通孔９ａと端子用貫通孔９ｂとの幅の差の１／２の深さを有する凹溝が形成される。
【００１９】
そして、図３（ａ）に示すように、複数のシート積層体７に形成した多数の凹溝用貫通孔９ａに飛散物質１１を充填し、端子形成用貫通孔９ｂに金属粉末とガラスを含有する導電物質１２を充填する。飛散物質１１は、脱バイ〜焼成時（熱処理時）に飛散する物質からなるもので、低温域で分解飛散する低温分解有機物と、高温域で分解飛散する高温分解有機物とを含有することが望ましい。また、導電物質１２は脱脂〜焼成時（熱処理時）に導電性端子となるもので、金属粉末５０〜８０体積％とケイ素を主成分とするガラス粉末２０〜５０体積％とからなる固形成分を含有するものが望ましい。
【００２０】
低温分解有機物としては、アクリル樹脂や、ブチラール樹脂などの有機高分子樹脂等があるが、本発明では、シート積層体７を加熱加圧して一体化する時における飛散物質１１の積層方向への収縮をグリーンシート１に近づけることができ、シート積層体７と飛散物質１１の収縮差に伴う積層界面の空隙、もしくは変形を防止するために、また、低温域での飛散物質の脱脂状態をグリーンシート１に近づけることができ、凹溝近傍におけるクラックやデラミネーションを抑制できるという点から、セラミックグリーンシート１に用いられるバインダ樹脂を、低温分解有機物として用いることが望ましい。
【００２１】
同様に導電物質のバインダ樹脂も、凹溝近傍におけるクラックやデラミネーションを抑制できるという点から、セラミックグリーンシート１に用いられるバインダ樹脂を用いることが望ましい。
【００２２】
特に、シート積層体７同士の加熱圧着時の接着力、及び脱バイ時の易分解性の点からアクリル樹脂が望ましい。尚、本発明では、低温分解有機物とは、６００℃までに分解飛散する有機物である。
【００２３】
また、高温分解有機物としては、フェノール粉末、アクリルビーズ、カーボンビーズ、もしくはカーボンファイバーがある。焼成温度近くまで、残留するという点、及びアクリル樹脂やブチラール樹脂などの有機高分子樹脂と混合してシート状の飛散物質の作製が容易という点から、高温分解有機物としては、カーボンビーズ、もしくはカーボンファイバーが望ましい。尚、本発明においては、高温分解有機物とは、７５０℃まで分解せずに残留する有機物である。
【００２４】
低温分解有機物と高温分解有機物の混合比率は、高温分解有機物１００重量部に対して低温分解有機物を２５〜６０重量部であることが望ましく、特に収縮を合致させるという点から、低温分解有機物は３５〜４５重量部であることが望ましい。
【００２５】
導電物質１２は、金属粉末５０〜８０体積％とケイ素を主成分とするガラス粉末２０〜５０体積％とからなる固形成分を含有することにより、後述する熱処理時に、ガラスが溶融し、溶融したガラス中に存在する導電性金属粒子が、内部電極の端部に集合し、素子本体の側面から突出する突起状の導電性端子が形成されるとともに、素子本体の側面において、拡散したグリーンシートの成分とケイ素を含むガラスが形成され、このガラスにより導電性端子の根元部が埋設され、導電性端子を内部電極端部に強固に接合することができる。
【００２６】
導電物質１２の金属粉末（導電性端子）は、銀、ニッケル、銅、金、アルミニウム、等の導電性を備えた金属及びそれらの合金からなり、応力を十分に吸収するという点から、ヤング率の低い銀、若しくは銀が主成分の合金が望ましい。
【００２７】
凹溝用貫通孔９ａ及び端子形成用貫通孔９ｂに充填される飛散物質１１及び導電物質１２は、スラリー状のものであっても良く、また、スラリー状のものをシート状に成形し、これらのシート状の飛散物質１１、導電物質１２を凹溝用貫通孔９ａ及び端子形成用貫通孔９ｂ内に収納し、充填しても良い。
【００２８】
シート状に成形された飛散物質１１、導電物質１２を貫通孔９ａ、９ｂ内に収納充填することにより、充填物の貫通孔９ａ、９ｂからのはみ出しを防止することができる。シート状の飛散物質１１を、シート積層体７の凹溝用貫通孔９ａ内に収容するには、図３（ｂ）に示すように、シート積層体７の表面に飛散物質シート１３を積層し、図３（ｃ）に示すように、これを、凹溝用貫通孔９ａを形成するために作製したプレス型により、押出量を制御して打ち抜き加工することにより、凹溝用貫通孔９ａを形成すると同時に、凹溝用貫通孔９ａ内にシート状の飛散物質１１を収納充填できる。この後、シート積層体７の表面に積層された残部の飛散物質シート１３を剥離することにより、凹溝用貫通孔９ａ内にシート状の飛散物質１１が収納されたシート積層体７を作製できる。
【００２９】
同様に導電物質１２の端子形成用貫通孔９ｂへの充填は、図示しないが、導電性ペーストで作製した導電物質シートをシート積層体７の表面に積層し、端子形成用貫通孔９ｂを形成するために作製したプレス型により、押出量を制御して打ち抜き加工することにより、端子形成用貫通孔９ｂを形成すると同時に、この端子形成用貫通孔９ｂ内にシート状の導電物質１２を充填できる。この後、シート積層体７の表面に積層された残部の導電物質シートを剥離することにより、端子形成用貫通孔９ｂ内にシート状の導電物質１２が収納されたシート積層体７を作製できる。尚、導電物質１２の充填の後に、飛散物質１１の充填を行っても良い。
【００３０】
これらの飛散物質シートや導電物質シートは、アクリル樹脂や、ブチラール樹脂などの有機物と、可塑剤とを混合したスラリーを作製し、グリーンシート１と同様に、例えばスリップキャステイング法により、厚み５０〜２５０μｍにて作製される。
【００３１】
この後、図４に示すように、シート積層体７を、上下のシート積層体において凹溝用貫通孔９ａ内の飛散物質１１と端子形成用貫通孔９ｂの導電物質１２が重畳するように交互に位置をずらして積層し、その後、５０〜２００℃で加熱を行いながら加圧して一体化し、積層体を作製する。
【００３２】
この後、積層体を、図４（ａ）、（ｂ）で示す一点鎖線で、即ち、凹溝用貫通孔９ａと、隣り合う端子形成用貫通孔９ｂの幅方向中心位置で切断して、図５に示すように、対向する側面に、飛散物質１１が充填された凹溝２１と、この凹溝２１間の側面に導電膜２２が交互に形成された、素子本体成形体２３を作製する。
【００３３】
この素子本体成形体２３は、対向する側面に内部電極パターン３一層おきに凹溝２１が形成されており、これらの凹溝２１の底面には内部電極パターン３端が露出し、さらに凹溝２１内には熱処理により分解する飛散物質１１が充填されている。また、凹溝２１間の素子本体成形体２３の側面には、内部電極パターン３一層おきに導電膜２２が形成され、外部電極が形成される素子本体成形体の対向する側面には、飛散物質１１と導電膜２２が交互に露出している。
【００３４】
その後、大気中において４００〜８００℃で５〜４０時間の脱バイを行なう。この際、飛散物質１１が分解飛散し、素子本体成形体２３の対向する側面に凹溝２１が形成される。その後、９００〜１２００℃で２〜５時間で本焼成が行われ、図６に示すように、導電膜２２中の導電性金属粒子が、内部電極２９の端部に集合し、素子本体３１の側面から突出する導電性端子３５が形成され、圧電体２７と内部電極２９が交互に積層された素子本体３１が作製される。この素子本体３１は柱状で、対向する側面には、底面に内部電極２９端が露出する凹溝２１が内部電極２９毎に交互に形成されており、凹溝２１間の内部電極２９端部には導電性端子３５が内部電極２９毎に交互に形成されている。
【００３５】
導電性端子３５は、図７に示すように、根元部がガラス５１に埋設され、上記したように、導電性端子３５の金属と、内部電極２９の金属が相互に拡散接合している。
【００３６】
この後、図８に示すように素子本体３１の凹溝２１及び導電性端子３５が形成された側面において、板状導電部材からなる外部電極３３を導電性端子３５側に押圧して荷重を加えた状態で７００〜９５０℃で熱処理することにより、導電性端子３５の先端部に板状導電部材からなる外部電極３３を接合する。
【００３７】
また、板状導電部材からなる外部電極３３は、銀、ニッケル、銅、金、アルミニウム等の導電性を備えた金属及びそれらの合金からなり、このうち、導電性端子３５との接合強度が強く、ヤング率が低いという点から、銀、若しくは銀が主成分の合金が望ましい。
【００３８】
尚、上記例では、導電性端子３５の先端部に板状導電部材からなる外部電極３３を接合した例について説明したが、導電性端子３５間における凹溝２１の開口部に、凹溝２１を覆うように低温で分解する紙を敷き、外部電極を形成する素子本体の側面に導電性樹脂を塗布し、１５０〜３００℃で熱処理を行い外部電極を形成してもよい。
【００３９】
この後、凹溝２１内にシリコーンゴム等の絶縁樹脂３９を充填し、また、内部電極２９端が露出している素子本体３１の他の側面にも絶縁樹脂を被覆して、積層型圧電素子を作製できる。
【００４０】
以上のような積層型圧電素子の製法では、寸法通りの凹溝２１を一挙にかつ確実に形成できるとともに、凹溝２１間の側面に金属とガラスを含有する導電膜２２を形成してなる素子本体成形体２３を、簡単な工程で容易に形成でき、脱バイ〜焼成（熱処理）工程後には、凹溝２１間の素子本体３１側面に露出した内部電極２９端部に、根元部がガラス５１に埋設され、かつ内部電極２９と拡散接合した導電性端子３５を形成できるため、焼結された素子本体３１の側面に導電性ペーストを塗布し、熱処理して突起状の導電性端子を形成する工程を別個に設ける必要がない。
【００４１】
そして、このような突起状の導電性端子３５が形成された素子本体３１の側面に、導電性端子３５の先端部を外部電極３３に接合したり、側面に導電性端子３５を埋設するように導電性ペーストを塗布して外部電極３３を形成することにより、素子本体３１に対する外部電極３３の付着強度を向上できる。
【００４２】
また、外部電極３３を導電性端子３５の先端部に接合して形成する場合には、導電性端子３５が外部電極３３に生じる応力を吸収し、該外部電極３３と内部電極２９の断線を抑制することができ、さらに、素子本体３１の導電性端子３５を形成した側面の表面近傍にガラス５１が形成されているため、導電性端子３５の根元部を補強でき、導電性端子３５と内部電極との接合強度を強固なものとすることができる。
【００４３】
尚、本発明の積層型電子部品の製法は、積層型圧電トランス、積層型コンデンサ、積層型圧電アクチュエータ等の積層型電子部品の製法に好適に用いられる。
【００４４】
【実施例】
チタン酸ジルコン酸鉛Ｐｂ（Ｚｒ，Ｔｉ）Ｏ₃からなる圧電体セラミックスの仮焼粉末と、有機高分子からなるバインダーと、可塑剤とを混合したスラリーを作製し、スリップキャステイング法により、厚み１００μｍのセラミックグリーンシートを作製した。
【００４５】
このグリーンシートの片面に内部電極３となる銀−パラジウムを主成分とする導電性ペーストをスクリーン印刷法により５μｍの厚みに印刷し、導電性ペーストを乾燥して内部電極パターンを形成した後、さらにこの内部電極パターン表面にグリーンシートを積層し、図１（ｂ）に示すような、内部電極パターンをグリーンシートで挟持したシート積層体を複数作製した。
【００４６】
これらのシート積層体の所定個所に、図２に示すように、複数の凹溝用貫通孔（幅２ｍｍ、長さ１０ｍｍ）、及び端子形成用貫通孔（幅０．６ｍｍ、長さ１０ｍｍ）を形成すると同時に、シート状飛散物質及びシート状導電物質を充填した。充填は、先ず、低温分解有機物であるアクリル樹脂を、高温分解有機物であるカーボンファイバー１００重量部に対して４０重量部の割合で混合し、これをシート状に成形して厚み２００μｍの飛散物質シートを作製した。
【００４７】
また、銀−パラジウム合金粉末を６０体積％と、残部がケイ素を主成分とし、アルミニウムを含むガラス粉末４０体積％との混合物にバインダーを加え、十分に混合して、これをシート状に成形して厚み２００μｍの導電物質シートを作製した。
【００４８】
この後、シート積層体の表面に飛散物質シートを積層し、凹溝用貫通孔を形成するプレス型により、押し出し量を制御して成形し、凹溝用貫通孔を形成すると同時に、この凹溝用貫通孔内にシート状飛散物質を充填し、シート積層体の表面に残存している飛散物質シートを剥離した。この後、シート積層体の表面に導電物質シートを積層し、端子形成用貫通孔を形成するプレス型により、押し出し量を制御して成形し、端子形成用貫通孔を形成すると同時に、この端子形成用貫通孔内にシート状の導電物質を充填し、シート積層体の表面に残存している導電物質シートを剥離した。
【００４９】
そして、図４に示すように、貫通孔の位置を交互にずらして積層し、その後、１５０℃で加熱を行いながら加圧して一体化し、積層体を貫通孔で切断して、内部に飛散物質が設けられた凹溝と、凹溝間の導電膜が側面に交互に形成された、図５に示すような素子本体成形体を作製した。
【００５０】
素子本体成形体は、対向する側面に内部電極パターン一層おきに凹溝が形成されており、これらの凹溝の底面には内部電極パターン端が露出し、さらに凹溝内には熱処理により分解する飛散物質が充填されていた。これら各素子本体の断面を観察した結果、凹溝の変形はなかった。また、凹溝間には、導電膜が形成されていた。
【００５１】
その後、８００℃で５時間の脱バイを行い、飛散物質を分解飛散させ、図５に示すように、素子本体成形体の対向する２側面に凹溝を形成した。
【００５２】
その後、１１００℃で５時間で本焼成を行い、図６に示すように、素子本体側面の凹溝間に導電性端子の形成された素子本体を得た。導電性端子は、図７に示すように、積層方向と同一方向に幅１０μｍ、高さ２０μｍであった。この導電性端子の根元部は、ガラス５１に埋設されていた。
【００５３】
この後、素子本体の対向する側面に、導電性端子の先端に当接するように、銀からなる厚み２５μｍの板状導電部材を導電性端子側に３０ｋＰａで押圧し９００℃で接合することで外部電極を形成した。
【００５４】
また、これとは別に、セルロース紙で凹溝を覆うように敷き、外部電極が形成される素子本体の側面に、Ａｇとポリイミドを主成分とする導電性樹脂を塗布し、３００℃で熱処理することで、セルロース紙を分解させるとともに、導電性樹脂を導電性端子と接着させることで外部電極を形成させた。
【００５５】
その後、凹溝内及び素子本体の外周面に絶縁体としてシリコーンゴムを充填し、外部電極にリード線を接続し、正極及び負極の外部電極にリード線を介して３ｋＶ／ｍｍの直流電界を１５分間印加して分極処理を行い、積層型圧電素子を作製した。
【００５６】
また、比較例として、シート積層体に端子形成用貫通孔を形成することなく、凹溝用貫通孔のみ形成して、素子本体を形成し、この素子本体の凹溝にシリコーンゴムを充填し、素子本体の側面に導電性樹脂を塗布後、熱処理することで外部電極を形成した。これを試料Ｎｏ．３に記載した。
【００５７】
また、シート積層体に、電極材料が充填される電極用貫通孔と絶縁材料が充填される絶縁用貫通孔を形成し、電極用貫通孔にガラスを含有しないＡｇ−Ｐｄスラリーを、絶縁用貫通孔にはガラス−アルミナ系セラミックスのスラリーを充填し、この後、上下のシート積層体において、電極用貫通孔と絶縁用貫通孔が重なるようにシート積層体を交互に位置をずらして積層し、この積層体を焼成した後、貫通孔で切断して、側面に電極材料と絶縁材料が交互に表出した素子本体を作製し、電極材料と絶縁材料が交互に表出した素子本体の側面に、Ａｇペーストを塗布して焼き付けて外部電極を形成した。これを試料Ｎｏ．４に記載した。
【００５８】
外部電極に１５０Ｖの直流電圧を印加した結果、積層方向に４０μｍの変位量が得られた。さらに、この素子に室温で０〜＋１５０Ｖの交流電圧を１２０Ｈｚの周波数にて印加し駆動試験を行った結果を表１示す。
【００５９】
【表１】

【００６０】
表１の結果より、導電性端子が形成されない、本発明の範囲外の試料Ｎｏ．３では内部電極と外部電極間で剥離が発生しスパークが起きていた。また、本発明の範囲外の試料Ｎｏ．４では、凹溝内のセラミックにクラックが発生しており、凹溝内の内部電極と外部電極間でショートが発生していた。一方、突起状の導電性端子が存在する本発明の試料Ｎｏ．１、２では駆動試験後も異常は見られなかった。
【００６１】
【発明の効果】
以上詳述した通り、本発明の積層型電子部品の製法では、素子本体成形体に凹溝を確実にかつ一挙に形成でき、脱バイ〜焼成（熱処理）工程後には、凹溝間の素子本体側面に露出した内部電極端部に、根元部がガラスに埋設され、かつ内部電極と拡散接合した導電性端子が形成され、これにより、内部電極の端部に導電性端子を強固に接合できるとともに、内部電極と外部電極との間におけるショートを防止でき、さらに突起状の導電性端子の先端部に板状導電部材からなる外部電極を接合して外部電極を形成したり、導電性端子を導電性樹脂からなる外部電極中に埋設して外部電極を形成するため、素子本体に対する外部電極の付着強度を向上できる。
【図面の簡単な説明】
【図１】本発明の積層型電子部品の製法に用いられるシート積層体の工程図であり、（ａ）はグリーンシート上に内部電極パターンを形成した平面図、（ｂ）は内部電極パターンをグリーンシートで挟持した断面図である。
【図２】シート積層体に多数の貫通孔を規則的に形成した平面図である。
【図３】（ａ）は貫通孔に飛散物質、導電物質を充填したシート積層体を示す断面図、（ｂ）（ｃ）はシート状飛散物質を凹溝用貫通孔に充填する工程図である。
【図４】（ａ）はシート積層体を交互に位置をずらして積層した状態を示す断面図、（ｂ）はその平面図である。
【図５】素子本体成形体の断面図である。
【図６】素子本体の断面図である。
【図７】導電性端子及びその近傍を拡大して示す断面図である。
【図８】積層型電子部品の断面図である。
【符号の説明】
１、５・・・グリーンシート
３・・・内部電極パターン
７・・・シート積層体
９ａ・・・凹溝用貫通孔
９ｂ・・・端子形成用貫通孔
１１・・・飛散物質（シート状飛散物質）
１２・・・導電物質（シート状導電物質）
２１・・・凹溝
２２・・・導電膜
２３・・・素子本体成形体
２７・・・圧電体
２９・・・内部電極
３１・・・素子本体
３３・・・外部電極
３５・・・導電性端子
３７・・・外部電極
５１・・・ガラス[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a multilayer electronic component, and in particular, a concave groove is formed by alternately forming a concave groove in which an end of an internal electrode is exposed on an opposing side surface of an element body in which ceramics and internal electrodes are alternately stacked. The present invention relates to a method for manufacturing a multilayer electronic component in which external electrodes alternately connected to internal electrodes are formed on the side surfaces.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a method for manufacturing a multilayer electronic component, a method described in JP-A-6-151999 is known.
[0003]
In the multilayer electronic component disclosed in this publication, first, a plurality of sheet laminates in which an internal electrode pattern is sandwiched between a pair of green sheets are filled with an electrode through-hole filled with an electrode material and an insulating material. Insulating through holes are formed, Ag-Pd slurry is filled in the electrode through holes, and glass-alumina ceramic slurry is filled in the insulating through holes. Thereafter, in the upper and lower sheet laminates, the electrode through holes are filled. Laminate sheet laminates alternately so that the holes and insulating through-holes overlap, and after firing this laminate, cut through the through-holes so that the electrode material and insulating material appear alternately on the side The obtained element body is obtained.
[0004]
Thereafter, an external electrode is formed by applying an Ag paste to the side surface of the element body where the electrode material and the insulating material are alternately exposed and baking, or applying a conductive adhesive and performing a curing process. Electronic parts were made.
[0005]
In such a multilayer electronic component, the electrode material formed on the side surface of the element body is connected to the end of the internal electrode pattern, and the area ratio of the electrode material on the side surface of the element body can be increased. The adhesion strength of the formed external electrode to the side surface of the element body can be improved to some extent.
[0006]
[Problems to be solved by the invention]
However, in the multilayer electronic component described in the above publication, since the side surface of the element body on which the external electrode is formed is flat, the Ag paste is applied and baked, or the conductive adhesive is applied and cured. There was a problem that the adhesion strength of the formed external electrode was still low.
[0007]
In addition, since the glass-alumina ceramics were filled in the groove and the internal electrode end and the external electrode were insulated, the ceramic in the groove was cracked by the expansion and contraction of the element body, and the internal electrode that should be originally insulated There is a problem that a short circuit occurs between the electrode and the external electrode.
[0008]
The present invention provides a multilayer electronic component capable of forming a concave groove according to a dimension at once and reliably, improving the adhesion strength of the external electrode to the element body, and preventing a short circuit between the internal electrode and the external electrode. The purpose is to provide a manufacturing method.
[0009]
[Means for Solving the Problems]
The method for producing a multilayer electronic component according to the present invention includes a step of producing an element body molded body obtained by alternately laminating a plurality of ceramic green sheets and a plurality of internal electrode patterns, and an opposing side surface of the element body molded body, A laminate type comprising: a step of exposing an end portion of the internal electrode pattern and forming a concave groove every other layer of the internal electrode pattern; and a step of heat-treating the element body molded body to produce an element body. A manufacturing method for electronic components,
A step of filling the groove of the element body molded body with a scattering material that is decomposed by the heat treatment, and a conductive material containing metal and glass on the side surface of the element body molded body between the adjacent groove grooves. Forming a conductive film;The heat treatment causes the conductive film to be diffusion-bonded to the internal electrode of the element body, and the base portion becomes a projecting conductive terminal embedded in the glass; andA step of bonding an external electrode to the conductive terminalWhen,It is characterized by including.
[0010]
The step of filling the concave grooves with the scattering material is to produce a sheet laminate in which the internal electrode pattern is sandwiched between a pair of ceramic green sheets, and the sheet made of the scattering material is formed on the surface of the sheet laminate. Laminating and punching the sheet laminate to form through holes for concave grooves, filling the through holes for concave grooves with the scattering material, and laminating a plurality of the sheet laminates to form the element body molded body The concave groove through hole filled with the scattering material is cut in the stacking direction of the sheet laminate..
[0011]
The step of forming a conductive film made of the conductive material includes producing a sheet laminated body in which the internal electrode pattern is sandwiched between a pair of the ceramic green sheets, and on the surface of the sheet laminated body. A sheet of conductive material containing metal and glass is laminated, and the sheet laminate is punched to form a terminal forming through hole, and the terminal forming through hole is filled with a conductive substance, The element body molded body is produced by laminating a plurality of elements, and the terminal forming through-hole filled with the conductive material is cut in the stacking direction of the element body molded body.
[0012]
In the multilayer electronic component of the present invention, the grooves can be formed all at once without performing groove processing one by one by conventional dicing or the like, the processing time can be shortened, and the manufacturing process can be simplified.In addition, on the opposite side surfaces, the inner electrode pattern ends are exposed, and recessed grooves filled with a scattering material that decomposes by heat treatment are alternately formed every other inner electrode pattern, and metal is formed on the side surfaces between the recessed grooves. An element body molded body formed by forming a conductive film containing glass can be easily formed by a simple process.
[0013]
Further, after the de-buying to firing (heat treatment) process, the protruding conductive terminals in which the root portions are embedded in glass at the end portions of the internal electrodes exposed on the side surfaces of the element body between the concave grooves and diffusion-bonded to the internal electrodes As a result, the conductive terminal can be firmly joined to the end portion of the internal electrode, the insulating resin can be filled in the concave groove, and cracks do not occur even when the element body expands and contracts. A short circuit between the electrode and the external electrode can be prevented.
[0014]
Furthermore, an external electrode made of a plate-like conductive member is joined to the end of the conductive terminal on the side surface of the element body where the conductive terminal is formed to form an external electrode, or the conductive terminal is made of a conductive resin. Since the external electrode is formed by being embedded in the external electrode, the adhesion strength of the external electrode to the element body can be improved.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 to FIG. 8 show process drawings for explaining a method of manufacturing a multilayer electronic component of the present invention. First, lead zirconate titanate Pb (Zr, Ti) O_ThreeA slurry is prepared by mixing a calcined powder of piezoelectric ceramics such as an organic binder made of an organic polymer such as acrylic resin or butyral resin, and a plasticizer, and has a thickness of 50 to 250 μm by a slip casting method, for example. A ceramic green sheet is produced.
[0016]
After the green sheet is punched to a predetermined size, as shown in FIG. 1A, a conductive paste mainly composed of silver-palladium as an internal electrode is formed on one side of the green sheet 1 by screen printing. The internal electrode pattern 3 is formed by printing to a thickness of 10 μm and drying.
[0017]
Thereafter, as shown in FIG. 1B, the produced green sheet 5 is stacked on the internal electrode pattern 3 so as to sandwich the internal electrode pattern 3, and is pressed to prepare a sheet laminate 7. As shown in FIG. 1 (a), a conductive paste is applied to the center of a wide green sheet 1, a green sheet 5 is laminated so as to cover the conductive paste, and this is cut. A sheet laminate 7 as shown in b) is produced. A large number of such sheet laminates 7 are produced.
[0018]
Next, using a punching device, as shown in FIG. 2, a plurality of concave groove through holes 9 a and terminal forming through holes 9 b are formed in a plurality of sheet laminates 7 in a regularly aligned state. These through-holes 9a for concave grooves have different dimensions depending on the size of the concave grooves, but have a rectangular shape with a width of about 2 mm and a length of about 10 mm, for example. Further, the terminal forming through hole 9b has a rectangular shape with a width of about 0.6 mm and a length of about 10 mm, for example. That is, when the element body is manufactured, a concave groove having a depth that is ½ of the width difference between the concave groove through hole 9a and the terminal through hole 9b is formed.
[0019]
And as shown to Fig.3 (a), the scattering material 11 is filled into many through-holes 9a for concave grooves formed in the some sheet | seat laminated body 7, and metal powder and glass are contained in the through-hole 9b for terminal formation. The conductive material 12 to be filled is filled. The scattering substance 11 is made of a substance that is scattered during debuying and firing (at the time of heat treatment), and preferably contains a low-temperature decomposition organic substance that decomposes and scatters in a low-temperature area and a high-temperature decomposition organic substance that decomposes and scatters in a high-temperature area. . The conductive material 12 becomes a conductive terminal at the time of degreasing to firing (at the time of heat treatment), and a solid component composed of 50 to 80% by volume of metal powder and 20 to 50% by volume of glass powder mainly containing silicon. What is contained is desirable.
[0020]
Examples of the low-temperature decomposition organic substance include an acrylic polymer and an organic polymer resin such as a butyral resin. In the present invention, the shattering substance 11 contracts in the stacking direction when the sheet laminate 7 is integrated by heating and pressing. Can be brought close to the green sheet 1 to prevent voids or deformation at the lamination interface due to the difference in contraction between the sheet laminate 7 and the scattering substance 11, and the degreasing state of the scattering substance in the low temperature region can be reduced to the green sheet. It is desirable to use the binder resin used for the ceramic green sheet 1 as the low-temperature decomposition organic substance because it can be close to 1 and cracks and delamination in the vicinity of the groove can be suppressed.
[0021]
Similarly, it is desirable that the binder resin used for the ceramic green sheet 1 is also used as the conductive resin binder because cracks and delamination in the vicinity of the concave grooves can be suppressed.
[0022]
In particular, an acrylic resin is desirable from the viewpoint of adhesive strength at the time of thermocompression bonding between the sheet laminates 7 and easy decomposability at the time of removal. In the present invention, the low-temperature decomposition organic substance is an organic substance that decomposes and scatters up to 600 ° C.
[0023]
Examples of the high-temperature decomposition organic substance include phenol powder, acrylic beads, carbon beads, and carbon fibers. From the point that it remains near the firing temperature, and because it is easy to produce a sheet-like scattered material by mixing with an organic polymer resin such as an acrylic resin or butyral resin, carbon beads or carbon Fiber is preferred. In the present invention, the high temperature decomposition organic substance is an organic substance remaining without being decomposed up to 750 ° C.
[0024]
The mixing ratio of the low temperature decomposition organic substance and the high temperature decomposition organic substance is preferably 25 to 60 parts by weight of the low temperature decomposition organic substance with respect to 100 parts by weight of the high temperature decomposition organic substance. It is desirable that it is -45 weight part.
[0025]
The conductive material 12 contains a solid component composed of 50 to 80% by volume of a metal powder and 20 to 50% by volume of a glass powder containing silicon as a main component. The conductive metal particles present inside gather at the end of the internal electrode to form a protruding conductive terminal protruding from the side surface of the element body, and the components of the diffused green sheet on the side surface of the element body A glass containing silicon and silicon is formed, and the base portion of the conductive terminal is embedded by this glass, and the conductive terminal can be firmly bonded to the end portion of the internal electrode.
[0026]
The metal powder (conductive terminal) of the conductive material 12 is made of a metal having conductivity such as silver, nickel, copper, gold, aluminum, or an alloy thereof, and absorbs stress sufficiently. Low silver or an alloy containing silver as a main component is desirable.
[0027]
The scattering material 11 and the conductive material 12 filled in the through hole 9a for concave groove and the through hole 9b for terminal formation may be in the form of a slurry, or the slurry is formed into a sheet, The sheet-like scattered material 11 and the conductive material 12 may be accommodated in the recessed groove through hole 9a and the terminal forming through hole 9b.
[0028]
By storing and filling the scattering material 11 and the conductive material 12 formed in a sheet shape into the through

holes

9a and 9b, it is possible to prevent the filler from protruding from the through

holes

9a and 9b. In order to accommodate the sheet-like scattered material 11 in the through-hole 9a for the concave groove of the sheet laminate 7, a scattered material sheet 13 is laminated on the surface of the sheet laminate 7 as shown in FIG. As shown in FIG. 3 (c), this is punched by controlling the amount of extrusion with a press die manufactured to form the concave groove through hole 9a, thereby forming the concave groove through hole 9a. Simultaneously with the formation, the sheet-like scattered substance 11 can be housed and filled in the through hole 9a for the concave groove. Thereafter, the remaining scattered substance sheet 13 laminated on the surface of the sheet laminated body 7 is peeled off, whereby the sheet laminated body 7 in which the sheet-like scattered substance 11 is accommodated in the concave groove through hole 9a can be produced. .
[0029]
Similarly, the filling of the conductive material 12 into the terminal formation through-hole 9b is not shown, but a conductive material sheet made of a conductive paste is laminated on the surface of the sheet laminate 7 to form the terminal formation through-hole 9b. For this reason, the terminal forming through-hole 9b can be formed at the same time as the terminal-forming through-hole 9b is formed by punching by controlling the amount of extrusion with the press die produced for this purpose. Thereafter, the remaining conductive material sheet laminated on the surface of the sheet laminated body 7 is peeled off, whereby the sheet laminated body 7 in which the sheet-like conductive material 12 is accommodated in the terminal forming through holes 9b can be produced. The scattering material 11 may be filled after the conductive material 12 is filled.
[0030]
For these scattering material sheets and conductive material sheets, a slurry in which an organic material such as acrylic resin or butyral resin is mixed with a plasticizer is prepared, and, like the green sheet 1, for example, a thickness of 50 to 250 μm by a slip casting method. It is produced by.
[0031]
Thereafter, as shown in FIG. 4, the sheet laminates 7 are alternately arranged in the upper and lower sheet laminates so that the scattered substances 11 in the through-holes 9a for concave grooves and the conductive substances 12 in the through holes 9b for terminal formation overlap. The positions are shifted to each other, and then the layers are pressed and integrated while heating at 50 to 200 ° C. to produce a laminate.
[0032]
Thereafter, the laminate is cut along the alternate long and short dash line shown in FIGS. 4A and 4B, that is, at the center position in the width direction of the through hole 9 a for concave grooves and the adjacent through hole 9 b for forming terminals, As shown in FIG. 5, a device body molded body 23 is produced in which concave grooves 21 filled with the scattering material 11 are formed on opposite side surfaces, and conductive films 22 are alternately formed on the side surfaces between the concave grooves 21. .
[0033]
In this element body molded body 23, concave grooves 21 are formed on the opposite side surfaces every three internal electrode patterns 3, and the ends of the internal electrode patterns 3 are exposed on the bottom surfaces of these concave grooves 21. The inside is filled with a scattering material 11 that decomposes by heat treatment. In addition, the conductive film 22 is formed on every three internal electrode patterns on the side surface of the element body molded body 23 between the concave grooves 21, and the scattered substance is formed on the opposite side surface of the element body molded body on which the external electrode is formed. 11 and the conductive film 22 are alternately exposed.
[0034]
Thereafter, de-bye treatment is performed in the atmosphere at 400 to 800 ° C. for 5 to 40 hours. At this time, the scattering material 11 is decomposed and scattered, and the concave grooves 21 are formed on the opposing side surfaces of the element body molded body 23. Thereafter, main baking is performed at 900 to 1200 ° C. for 2 to 5 hours. As shown in FIG. 6, the conductive metal particles in the conductive film 22 gather at the end of the internal electrode 29, and Conductive terminals 35 projecting from the side surfaces are formed, and an element body 31 is produced in which piezoelectric bodies 27 and internal electrodes 29 are alternately stacked. The element body 31 has a columnar shape, and on the opposite side surfaces, the concave grooves 21 in which the ends of the internal electrodes 29 are exposed are alternately formed on the bottom surface for each internal electrode 29, and at the ends of the internal electrodes 29 between the concave grooves 21. The conductive terminals 35 are alternately formed for each internal electrode 29.
[0035]
As shown in FIG. 7, the base portion of the conductive terminal 35 is embedded in the glass 51, and as described above, the metal of the conductive terminal 35 and the metal of the internal electrode 29 are diffusion-bonded to each other.
[0036]
After that, as shown in FIG. 8, on the side surface of the element body 31 where the concave groove 21 and the conductive terminal 35 are formed, the external electrode 33 made of a plate-like conductive member is pressed to the conductive terminal 35 side to apply a load. In this state, the external electrode 33 made of a plate-like conductive member is joined to the tip of the conductive terminal 35 by heat treatment at 700 to 950 ° C.
[0037]
The external electrode 33 made of a plate-like conductive member is made of a metal having conductivity such as silver, nickel, copper, gold, and aluminum, and an alloy thereof, and of these, the bonding strength with the conductive terminal 35 is strong. From the viewpoint of low Young's modulus, silver or an alloy containing silver as a main component is desirable.
[0038]
In the above example, the example in which the external electrode 33 made of a plate-like conductive member is joined to the tip of the conductive terminal 35 has been described. However, the groove 21 is formed in the opening of the groove 21 between the conductive terminals 35. An external electrode may be formed by laying paper that decomposes at a low temperature so as to cover, applying a conductive resin to the side surface of the element body that forms the external electrode, and performing heat treatment at 150 to 300 ° C.
[0039]
Thereafter, the concave groove 21 is filled with an insulating resin 39 such as silicone rubber, and the other side surface of the element main body 31 where the end of the internal electrode 29 is exposed is covered with the insulating resin, so that the laminated piezoelectric element is formed. Can be produced.
[0040]
In the manufacturing method of the multilayer piezoelectric element as described above, the concave grooves 21 having the dimensions can be formed at once and reliably, and the conductive film 22 containing metal and glass is formed on the side surfaces between the concave grooves 21. The body molded body 23 can be easily formed by a simple process. After the de-buying to firing (heat treatment) process, the root portion is formed of the glass 51 at the end of the internal electrode 29 exposed on the side of the element body 31 between the concave grooves 21. Since the conductive terminal 35 embedded in and diffusely bonded to the internal electrode 29 can be formed, a conductive paste is applied to the side surface of the sintered element body 31, and heat treatment is performed to form a protruding conductive terminal. There is no need to provide a separate process.
[0041]
Then, the tip of the conductive terminal 35 is joined to the external electrode 33 on the side surface of the element body 31 on which the protruding conductive terminal 35 is formed, or the conductive terminal 35 is embedded in the side surface. By applying the conductive paste to form the external electrode 33, the adhesion strength of the external electrode 33 to the element body 31 can be improved.
[0042]
Further, when the external electrode 33 is formed by bonding to the tip of the conductive terminal 35, the conductive terminal 35 absorbs stress generated in the external electrode 33 and suppresses disconnection between the external electrode 33 and the internal electrode 29. Further, since the glass 51 is formed in the vicinity of the surface of the side surface of the element body 31 where the conductive terminal 35 is formed, the base portion of the conductive terminal 35 can be reinforced, and the conductive terminal 35 and the internal electrode can be reinforced. It is possible to make the joint strength strong.
[0043]
The method for manufacturing a multilayer electronic component of the present invention is suitably used for a method of manufacturing a multilayer electronic component such as a multilayer piezoelectric transformer, a multilayer capacitor, or a multilayer piezoelectric actuator.
[0044]
【Example】
Lead zirconate titanate Pb (Zr, Ti) O_ThreeA ceramic green sheet having a thickness of 100 μm was prepared by a slip casting method using a ceramic ceramic calcined powder, an organic polymer binder, and a plasticizer.
[0045]
A conductive paste mainly composed of silver-palladium, which becomes the internal electrode 3, is printed on one side of the green sheet to a thickness of 5 μm by screen printing, and the conductive paste is dried to form an internal electrode pattern. A green sheet was laminated on the surface of the internal electrode pattern to produce a plurality of sheet laminates in which the internal electrode pattern was sandwiched between the green sheets as shown in FIG.
[0046]
As shown in FIG. 2, a plurality of concave groove through holes (width 2 mm, length 10 mm) and terminal forming through holes (width 0.6 mm, length 10 mm) are provided at predetermined positions of these sheet laminates. Simultaneously with the formation, the sheet-like scattering substance and the sheet-like conductive substance were filled. First, acrylic resin, which is a low-temperature decomposition organic substance, is mixed at a ratio of 40 parts by weight with respect to 100 parts by weight of carbon fiber, which is a high-temperature decomposition organic substance. Was made.
[0047]
Further, a binder is added to a mixture of 60% by volume of the silver-palladium alloy powder and the remaining 40% by volume of the glass powder containing silicon as a main component and containing aluminum, and the mixture is sufficiently mixed to form a sheet. Thus, a conductive material sheet having a thickness of 200 μm was produced.
[0048]
Thereafter, the scattering material sheet is laminated on the surface of the sheet laminate, and the extrusion is controlled by a press die that forms the through hole for the concave groove to form the through hole for the concave groove. The through-hole for use was filled with a sheet-like scattering material, and the scattering material sheet remaining on the surface of the sheet laminate was peeled off. After that, a conductive material sheet is laminated on the surface of the sheet laminate, and formed by controlling the amount of extrusion by a press die for forming a terminal forming through hole, and simultaneously forming the terminal forming through hole. The sheet-shaped conductive material was filled in the through-hole for use, and the conductive material sheet remaining on the surface of the sheet laminate was peeled off.
[0049]
Then, as shown in FIG. 4, the positions of the through holes are alternately shifted and laminated, and then the pressure is unified while heating at 150 ° C., and the laminated body is cut at the through holes, and the scattering material is contained inside. An element body molded body as shown in FIG. 5 was produced, in which concave grooves provided with, and conductive films between the concave grooves were alternately formed on the side surfaces.
[0050]
In the element body molded body, concave grooves are formed on the opposite side surfaces every other internal electrode pattern, and the ends of the internal electrode patterns are exposed on the bottom surfaces of these concave grooves, and further, the concave grooves are decomposed by heat treatment. It was filled with flying material. As a result of observing the cross section of each element body, the groove was not deformed. Moreover, the electrically conductive film was formed between the ditch | grooves.
[0051]
After that, debuying was performed at 800 ° C. for 5 hours to decompose and disperse the scattered substances, and as shown in FIG. 5, concave grooves were formed on the two opposite side surfaces of the element body molded body.
[0052]
Then, main baking was performed at 1100 ° C. for 5 hours to obtain an element body in which conductive terminals were formed between the concave grooves on the side face of the element body as shown in FIG. As shown in FIG. 7, the conductive terminal had a width of 10 μm and a height of 20 μm in the same direction as the stacking direction. The base portion of the conductive terminal was embedded in the glass 51.
[0053]
Thereafter, a plate-like conductive member made of silver having a thickness of 25 μm is pressed against the conductive terminal side at 30 kPa so as to abut the tip of the conductive terminal on the opposing side surface of the element body, and bonded at 900 ° C. An electrode was formed.
[0054]
Separately from this, it is laid so as to cover the groove with cellulose paper, and a conductive resin mainly composed of Ag and polyimide is applied to the side surface of the element body on which the external electrode is formed, and heat-treated at 300 ° C. As a result, the cellulose paper was decomposed, and an external electrode was formed by adhering a conductive resin to the conductive terminal.
[0055]
Thereafter, silicone rubber as an insulator is filled in the groove and the outer peripheral surface of the element body, lead wires are connected to the external electrodes, and a DC electric field of 3 kV / mm is applied to the positive and negative external electrodes via the lead wires. Polarization treatment was performed by applying for a minute to produce a laminated piezoelectric element.
[0056]
In addition, as a comparative example, without forming the terminal formation through hole in the sheet laminate, forming only the through hole for the concave groove, forming the element body, filling the concave groove of the element body with silicone rubber, An external electrode was formed by applying a conductive resin to the side surface of the element body and then performing a heat treatment. This is designated as Sample No. 3.
[0057]
In addition, an electrode through hole filled with an electrode material and an insulating through hole filled with an insulating material are formed in the sheet laminate, and Ag-Pd slurry not containing glass is passed through the electrode through hole for insulation. The holes are filled with a slurry of glass-alumina ceramics, and thereafter, in the upper and lower sheet laminates, the sheet laminates are alternately shifted and laminated so that the electrode through holes and the insulating through holes overlap, After firing this laminate, cut through the through-hole to produce an element body in which the electrode material and insulating material are alternately exposed on the side surface, and on the side surface of the element body in which the electrode material and insulating material are alternately exposed. Then, an Ag paste was applied and baked to form an external electrode. This is designated as Sample No. 4.
[0058]
As a result of applying a DC voltage of 150 V to the external electrode, a displacement of 40 μm was obtained in the stacking direction. Furthermore, Table 1 shows the results of a drive test in which an AC voltage of 0 to +150 V was applied to this device at a frequency of 120 Hz at room temperature.
[0059]
[Table 1]

[0060]
From the results shown in Table 1, sample Nos. Out of the scope of the present invention in which conductive terminals were not formed. In No. 3, peeling occurred between the internal electrode and the external electrode, and sparking occurred. In addition, sample No. outside the scope of the present invention. In No. 4, a crack occurred in the ceramic in the groove, and a short circuit occurred between the internal electrode and the external electrode in the groove. On the other hand, the sample No. of the present invention in which a protruding conductive terminal is present. In 1 and 2, no abnormality was observed after the driving test.
[0061]
【The invention's effect】
As described above in detail, in the method for manufacturing a multilayer electronic component according to the present invention, a groove can be formed reliably and at once in the element body molded body. At the end of the internal electrode exposed on the side surface, a conductive terminal is formed in which the root portion is embedded in glass and diffusion-bonded to the internal electrode, whereby the conductive terminal can be firmly bonded to the end of the internal electrode. Short circuit between the internal electrode and the external electrode can be prevented, and the external electrode made of a plate-like conductive member can be joined to the tip of the protruding conductive terminal to form the external electrode, or the conductive terminal can be made conductive Since the external electrode is formed by being embedded in the external electrode made of the conductive resin, the adhesion strength of the external electrode to the element body can be improved.
[Brief description of the drawings]
FIG. 1 is a process diagram of a sheet laminate used in a method for producing a multilayer electronic component according to the present invention, wherein (a) is a plan view in which an internal electrode pattern is formed on a green sheet, and (b) is an internal electrode pattern. It is sectional drawing clamped with the green sheet.
FIG. 2 is a plan view in which a large number of through holes are regularly formed in a sheet laminate.
FIGS. 3A and 3B are cross-sectional views showing a sheet laminate in which a through-hole is filled with a scattering material and a conductive material, and FIGS. 3B and 3C are process diagrams for filling the through-hole for a concave groove with a sheet-like scattering material. is there.
FIG. 4A is a cross-sectional view showing a state in which sheet laminates are alternately laminated at different positions, and FIG. 4B is a plan view thereof.
FIG. 5 is a cross-sectional view of an element body molded body.
FIG. 6 is a cross-sectional view of an element body.
FIG. 7 is an enlarged sectional view showing a conductive terminal and its vicinity.
FIG. 8 is a cross-sectional view of a multilayer electronic component.
[Explanation of symbols]
1,5 ... Green sheet
3 ... Internal electrode pattern
7 ... Sheet laminate
9a: through hole for concave groove
9b ... Terminal formation through hole
11 ... Scattering material (sheet-like scattering material)
12 ... Conductive substance (sheet-like conductive substance)
21 ... concave groove
22: Conductive film
23 ... Element body molded body
27 ... Piezoelectric material
29 ... Internal electrode
31 ... Element body
33 ... External electrode
35 ... Conductive terminal
37 ... External electrode
51 ... Glass

Claims

A step of producing an element main body formed by alternately laminating a plurality of ceramic green sheets and a plurality of internal electrode patterns; and exposing the end portions of the internal electrode patterns on opposing side surfaces of the element main body; And a step of forming a concave groove every other layer of the internal electrode pattern, and a step of manufacturing the element body by heat-treating the element body molded body,
A step of filling the groove of the element body molded body with a scattering material that is decomposed by the heat treatment, and a conductive material containing metal and glass on the side surface of the element body molded body between the adjacent groove grooves. A step of forming a conductive film, a step of forming a projecting conductive terminal in which the conductive film is diffusion-bonded to an internal electrode of the element body and a root portion is embedded in the glass by the heat treatment; preparation of multilayer electronic components, which comprises a step of bonding the external electrodes to the conductive terminal.

The step of filling the concave groove with the scattering material produces a sheet laminate in which the internal electrode pattern is sandwiched between a pair of ceramic green sheets, and a sheet made of the scattering material is formed on the surface of the sheet laminate. Laminating and punching the sheet laminate to form through holes for concave grooves, filling the through holes for concave grooves with the scattering material, and laminating a plurality of the sheet laminates to form the element body molded body The method for manufacturing a multilayer electronic component according to claim 1, wherein the through hole for a concave groove filled with the scattering material is cut in a stacking direction of the sheet laminate.

The step of forming a conductive film made of the conductive material includes producing a sheet laminated body in which the internal electrode pattern is sandwiched between a pair of the ceramic green sheets, and on the surface of the sheet laminated body. A sheet of conductive material containing metal and glass is laminated, and the sheet laminate is punched to form a terminal forming through hole, and the terminal forming through hole is filled with a conductive substance, The element body molded body is produced by laminating a plurality of layers, and the terminal forming through-hole filled with the conductive material is cut in the stacking direction of the element body molded body. A manufacturing method for multilayer electronic components.

The method for producing a multilayer electronic component according to any one of claims 1 to 3, further comprising a step of joining an external electrode made of a plate-like conductive member to a tip portion of the conductive terminal.

The method for producing a multilayer electronic component according to any one of claims 1 to 3, further comprising a step of embedding the conductive terminal in an external electrode made of a conductive resin.