【０００１】
【発明の属する技術分野】
本発明は、半導体レーザ（ＬＤ），フォトダイオード（ＰＤ）等の光半導体素子を収納する光半導体素子収納用パッケージおよび光半導体装置に関する。
【０００２】
【従来の技術】
従来の光通信等の分野において高い周波数で作動する半導体レーザ（ＬＤ），フォトダイオード（ＰＤ）等の光半導体素子を気密封止して収納した光半導体装置の例を図３に示す。図３は光半導体素子としてＬＤを内部に収納したものの断面図である。同図において、２１は基体、２２は光半導体素子、２３は金属製の蓋体、２４は透光性部材、２６は光ファイバである。
【０００３】
基体２１は鉄（Ｆｅ）−ニッケル（Ｎｉ）−コバルト（Ｃｏ）合金や銅（Ｃｕ）−タングステン（Ｗ）合金等の金属から成り、その上側主面の略中央部には、光半導体素子２２が、アルミナ（Ａｌ２Ｏ３）質焼結体等のセラミックスから成る略直方体の基台２８を介して基体２１の上側主面に発光部を上側に向けて搭載固定される。この構成により、光半導体素子２２から発する光信号が基体２１の上方へ出射されることとなる。また、基体２１には、Ｆｅ−Ｎｉ合金やＦｅ−Ｎｉ−Ｃｏ合金等の金属からなる外部接続用ピン２５を挿通させるために上下主面間を貫通する貫通孔２１ａが形成されており、貫通孔２１ａに光半導体装置内外を導通する端子としての外部接続用ピン２５を挿通させるとともに、外部接続用ピン２５と貫通孔２１ａとの隙間にガラス等の誘電体から成る接合材を充填し、基体２１と外部接続用ピン２５とを気密に接合する。これにより、外部接続用ピン２５が光半導体装置内外を導通する端子として機能する。
【０００４】
なお、基台２８に搭載された光半導体素子２２は、その電極が外部接続用ピン２５の光半導体素子２２側の先端とボンディングワイヤ２９等を介して電気的に接続されている。
【０００５】
また、基体２１の上側主面の外周部に接合され、上端が閉じられ下端が開かれた筒状であり上端面２３ａの略中央部に貫通孔２３ｂが形成されており、Ｆｅ−Ｎｉ−Ｃｏ合金等の金属から成る蓋体２３が設けられる。蓋体２３の下端２３ｃは、例えば図３のような鍔状となっており、これにより基体２１と蓋体２３との接合面積が大きくなり、基体２１と蓋体２３とで構成される容器内部の気密信頼性が向上する。
【０００６】
さらに、貫通孔２３ｂを塞ぐように、貫通孔２３ｂの上端面２３ａ側開口の周囲に透光性部材２４が接合される。透光性部材２４はガラスやサファイア等から成る円板状，レンズ状，球状または半球状等のものであり、ガラスによる接合や半田付け等により蓋体２３に気密に接合される。
【０００７】
このような基体２１、蓋体２３および透光性部材２４から主に構成される容器内部に光半導体素子２２を収容し気密に封止する。
【０００８】
最後に、光ファイバ２６固定用の筒状の金属製の固定部材２７が、蓋体２３の外周の鍔状部に溶接され、光ファイバ２６が固定部材２７の上面の貫通孔に外部から挿通固定されて透光性部材２４の上方に固定され、外部接続用ピン２５の外側の先端部が外部電気回路（図示せず）に電気的に接続されることによって、光半導体装置となる（例えば、下記の特許文献１参照）。
【０００９】
この光半導体装置は、外部電気回路から供給される電気信号によって光半導体素子２２にレーザ光等の光を励起させ、この光を透光性部材２４、光ファイバ２６の順に透過させ、光ファイバ２６を介して外部に伝送させることによって、高速光通信等に使用される光半導体装置として機能する。この場合、光半導体素子２２から光信号が正常に発光しているか確認するためのモニタ用ＰＤ（図示せず）が搭載されていてもよい。または、外部から光ファイバ２６を介して伝送してくる光信号を、透光性部材２４を透過させ光半導体素子２２に受光させて、光信号を電気信号に変換することによって、高速光通信等に使用される光半導体装置として機能する。
【００１０】
【特許文献１】
特開２００１−１８３３６９号公報
【００１１】
【発明が解決しようとする課題】
しかしながら、上記従来の光半導体装置において、外部接続用ピン２５が基体２１の貫通孔２１ａに挿通されガラス等を介して気密に接合される構成であるため、外部接続用ピン２５の直径寸法の最小加工限界、貫通孔２１ａの孔寸法、隣接する貫通孔２１ａ間の間隔の最小加工限界等の制約があり、そのため、基体２１に外部接続用ピン２５を１本挿入するために大きな面積が必要とされ、基体２１に取り付けられる外部接続用ピン２５の本数が数本に限られるという問題点があった。
【００１２】
さらに、光半導体装置内にはＬＤ，ＰＤ等の光半導体素子２２やモニタ用ＰＤのみが収容され、光半導体素子２２を駆動するためのドライバＩＣは別の半導体素子収納用パッケージ内に収納され、外部電気回路を介してドライバＩＣと光半導体装置とを電気的に接続する必要があり、光半導体素子２２を駆動させるための装置全体が大型化するという問題点もあった。
【００１３】
また、外部接続用ピン２５をガラス等の接合材を介して基体２１に接合しただけの端子構造であるため、外部接続用ピン２５に外部から応力が加わった場合に接合材にクラック等の破損が生じ、光半導体装置内部の気密が損なわれるという問題点があった。
【００１４】
さらに、外部接続用ピン２５の貫通孔２１ａに挿入されていない部位を特性インピーダンスに整合させた信号線路とするのが困難であり、外部接続用ピン２５を伝送する高周波信号が外部接続用ピン２５で反射等して伝送損失が生じ、高周波信号を効率よく伝送できなくなるという問題点もあった。特に、２ＧＨｚ以上の高周波になると伝送効率が著しく劣化し易くなっていた。
【００１５】
また、現在光信号の発光源として用いられるＬＤの多くは、光信号が光半導体素子２２の側面から発光するため、光ファイバ２６の方向に発光させるためには、光半導体素子２２を基体２１の上側主面に対して垂直な面に搭載する必要がある。従って、基体２１の上側主面に基台２８を設け、さらに基台２８の基体２１の上側主面に対して垂直な面に光半導体素子２２を搭載するため、光半導体素子２２と外部接続用ピン２５とをボンディングワイヤ２９により接続する際、作業性が悪く手間がかかるという問題点があった。
【００１６】
従って、本発明は上記問題点に鑑み完成されたものであり、その目的は、光半導体装置に取り付けられる端子数を増やして内部に収容する集積回路素子（ＩＣ）等の部品を増加させ、光半導体装置を高集積化および多機能化させるとともに、高周波信号を効率よく伝送させ得るものとし、また内部の気密信頼性を向上させ、光半導体素子を長期にわたり正常かつ安定に作動させ得るものとすることにある。
【００１７】
【課題を解決するための手段】
本発明の光半導体素子収納用パッケージは、略中央部に断面形状が略長方形の貫通穴が形成されている金属から成る板状の基体と、上端面の略中央部に貫通孔が形成されているとともに下端が開かれた筒状とされ、前記基体の上側主面の外周部に下端が接合される金属から成る蓋体と、前記貫通孔の上端面側開口の周囲に接合された透光性部材とを具備しており、前記基体は、前記貫通穴に、一主面に一辺から対向する他辺にかけて線路導体が形成されるとともに前記一主面の一端部に光半導体素子の載置部が設けられた誘電体から成る平板部および該平板部の前記一主面に前記線路導体の一部を間に挟んで接合された誘電体から成る立壁部から成る入出力端子が、前記一端部を前記基体と前記蓋体との間に位置させるとともに前記平板部の他主面を前記貫通穴の一方の長辺側にして嵌着されている光半導体素子収納用パッケージにおいて、前記基体は、前記貫通穴の他方の長辺側の前記上側主面と内面との間に段差が形成されており、前記立壁部の前記段差側の面に一側面が接合されるとともに前記段差の底面に他側面側の下面が接合されて前記立壁部と前記段差との間の隙間を塞ぐ略長方形の金属板が設けられていることを特徴とする。
【００１８】
本発明の光半導体素子収納用パッケージは、金属から成る板状の基体は貫通穴の他方の長辺側の上側主面と内面との間に段差が形成されており、立壁部の段差側の面に一側面が接合されるとともに段差の底面に他側面側の下面が接合されて立壁部と段差との間の隙間を塞ぐ略長方形の金属板が設けられていることから、貫通穴に入出力端子を嵌着する際に、金属板を貫通穴の段差に載置した状態で入出力端子を貫通穴に挿入し、金属板を段差の底面で入出力端子の幅に合わせてスライドさせて位置を調整した後、貫通穴を塞ぐように金属板を接合することができる。このように、基体の段差の底面に他側面側の下面が載置されている金属板は、接合される前に段差の底面でスライドさせて位置調整できるので、金属加工の精度によって貫通穴の大きさがばらついていたり、焼成時の収縮ばらつきにより入出力端子の寸法がばらついていても、入出力端子と貫通穴の長辺部におけるクリアランス（間隔）を確実に塞ぐことができるので、基体の入出力端子接合部における気密性を向上させることができる。
【００１９】
また、金属板は基体よりも薄くすることができ、金属板と入出力端子との接合部で入出力端子が金属板に接する面積を小さくできるので、金属板の部位で入出力端子にかかる基体との熱膨張差による応力を緩和させ、入出力端子にクラック等の破損が生じるのを防止でき、入出力端子の接合部における気密性をより向上させることができる。
【００２０】
さらに、貫通穴に、一主面に一辺から対向する他辺にかけて線路導体が形成されるとともに一主面の一端部に光半導体素子の載置部が設けられた誘電体から成る平板部およびこの平板部の一主面に線路導体の一部を間に挟んで接合された誘電体から成る立壁部から成る入出力端子が、一端部を基体と蓋体との間に位置させて嵌着されていることから、入出力端子に微細な間隔をもって電極パッド、配線導体および内部配線等を多数形成することができ、その結果、光半導体素子やモニタ用ＰＤだけでなく、光半導体素子を駆動するためのドライバＩＣ等を入出力端子の表面に設けることができ、信号入出力および光半導体素子の駆動や制御を入出力端子で行なうことができる。従って、外部電気回路に設けられていたドライバＩＣ等を光半導体装置の内部や入出力端子の外側に実装し高集積化できることから、光半導体素子を駆動させるための装置全体を小型化できる。
【００２１】
また、貫通穴に入出力端子が嵌着されていることによって、従来のガラス接合された外部接続用ピンに比較して、外部接続用ピンの接合部にクラック等の破損が生じて光半導体装置内部の気密が破れるのを有効に抑制することができる。従って、外部接続用ピンをガラス等の接合材を介して基体の貫通孔に接合した従来の構造に比べ気密信頼性が大幅に向上する。また外部接続用ピンを介すことなく、入出力端子の線路導体で外部電気回路に接続できるため、高周波信号が反射等して伝送損失が生じるのを抑制し、高周波信号の伝送効率を大幅に改善することができる。
【００２２】
さらに、従来のように光半導体素子と外部接続用ピンとをボンディングワイヤにより接続する必要はなく、線路導体と光半導体素子とを同じ平板部の一主面上においてボンディングワイヤにより接続することができるため、ボンディングワイヤによる電気的な接続が容易となるとともに、ボンディングワイヤの長さも短くすることができボンディングワイヤのインダクタンスを小さくして高周波信号の伝送効率を向上させることができる。
【００２３】
本発明の光半導体装置は、本発明の光半導体パッケージと、前記載置部に基台を介して載置固定されるとともに入出力端子に電気的に接続された光半導体素子と、前記基体の上側主面に接合された前記蓋体とを具備したことを特徴とする。
【００２４】
本発明の光半導体装置は、上記の構成により、上記本発明の光半導体素子収納用パッケージを用いた高性能で信頼性の高いものとなる。
【００２５】
【発明の実施の形態】
本発明の光半導体素子収納用パッケージ（以下、パッケージともいう）および光半導体装置について以下に詳細に説明する。図１（ａ）は本発明のパッケージを用いた光半導体装置について実施の形態の一例を示す断面図、図１（ｂ）は図１（ａ）の要部拡大下面図、図２（ａ）は本発明の光半導体装置について実施の形態の他の例を示す断面図、図２（ｂ）は図２（ａ）の要部拡大下面図である。これらの図において、１は金属製の基体、２は光半導体素子、３は金属製の蓋体、４は透光性部材、５は入出力端子、６は光ファイバである。
【００２６】
本発明のパッケージは、略中央部に断面形状が略長方形の貫通穴１ａが形成されている金属から成る板状の基体１と、上端面３ａの略中央部に貫通孔３ｂが形成されているとともに下端３ｃが開かれた筒状とされ、基体１の上側主面の外周部に下端３ｃが接合される金属から成る蓋体３と、貫通孔３ｂの上端面３ａ側開口の周囲に接合された透光性部材４とを具備しており、基体１は、貫通穴１ａに、一主面に一辺から対向する他辺にかけて線路導体５ｃが形成されるとともに一主面の一端部に光半導体素子２の載置部が設けられた誘電体から成る平板部５ｂおよび平板部５ｂの一主面に線路導体５ｃの一部を間に挟んで接合された誘電体から成る立壁部５ａから成る入出力端子５が、一端部を基体１と蓋体３との間に位置させるとともに平板部５ｂの他主面を貫通穴１ａの一方の長辺側にして嵌着されているものにおいて、基体は、貫通穴１ａの他方の長辺側の上側主面と内面との間に段差１ｂが形成されており、立壁部５ａの段差１ｂ側の面に一側面が接合されるとともに段差１ｂの底面に他側面側の下面が接合されて立壁部５ａと段差１ｂとの間の隙間を塞ぐ略長方形の金属板１ｃが設けられている。
【００２７】
本発明の基体１および金属板１ｃは、Ｆｅ−Ｎｉ−Ｃｏ合金やＣｕ−Ｗ合金等の金属のインゴットに圧延加工や打ち抜き加工等の従来周知の金属加工法を施すことによって所定形状に製作される。また、基体１には、図１（ｂ），図２（ｂ）に示すように、主面の中央部に断面形状が略長方形の貫通穴１ａが形成されている。この貫通穴１ａの内面には、入出力端子５の表面に設けられたメタライズ層が、銀（Ａｇ）ロウ等のロウ材によって接合されることにより、貫通穴１ａを塞ぐようにして入出力端子５が気密に接合される。
【００２８】
段差１ｂの底面に載置固定されている金属板１ｃは、金属板１ｃを貫通穴１ａの段差１ｂに載置した状態で入出力端子５を貫通穴１ａに挿入し、金属板１ｃを段差１ｂの底面で入出力端子５の幅に合わせてスライドさせて位置を調整した後、貫通穴１ａを塞ぐように金属板１ｃを接合することができる。このように、金属板１ｃは、段差１ｂの底面でスライドさせて位置調整できるので、金属加工の精度によって貫通穴１ａの大きさがばらついていたり、焼成時の収縮ばらつきにより入出力端子５の高さがばらついていても、入出力端子５と基体１との長辺部におけるクリアランスを確実に塞ぐことができるので、基体１の入出力端子５の接合部における気密性を向上させることができる。
【００２９】
さらに、金属板１ｃは基体１よりも薄くすることができ、従来に比べ金属板１ｃと入出力端子５との接合部で入出力端子５が金属板１ｃに接する面積を小さくできるので、入出力端子５にかかる金属板１ｃとの熱膨張差による応力を緩和させ、入出力端子５にクラック等の破損が生じるのを防止でき、入出力端子５の接合部における気密性を向上させることができる。
【００３０】
また、金属板１ｃは、立壁部５ａと反対側の他側面が段差１ｂの側面に当接しておらず隙間があるのがよい。この場合、その隙間に金属板１ｃを接合するためのロウ材のメニスカスや溜まりが形成されて接合強度が向上する。
【００３１】
本発明の入出力端子５は、図１（ａ）に示すように、一主面に一辺から対向する他辺にかけて線路導体５ｃが形成されるとともに一主面の一端部に光半導体素子２の載置部が設けられた平板部５ｂおよびこの平板部５ｂの一主面に線路導体５ｃの一部を間に挟んで接合された立壁部５ａから構成される。平板部５ｂおよび立壁部５ａは、Ａｌ２Ｏ３質焼結体（アルミナセラミックス），ＡｌＮ質焼結体，３Ａｌ２Ｏ３・２ＳｉＯ２質焼結体等の誘電体から成り、また、線路導体５ｃは、タングステン（Ｗ）やモリブデン（Ｍｏ）等のメタライズ層から成る。
【００３２】
このような入出力端子５は以下のようにして作製される。例えば、平板部５ｂおよび立壁部５ａがＡｌ２Ｏ３質焼結体から成る場合、先ず酸化アルミニウム、酸化珪素（ＳｉＯ２）、酸化マグネシウム（ＭｇＯ）および酸化カルシウム（ＣａＯ）等の原料粉末に適当な有機バインダー、可塑剤、溶剤等を添加混合して泥漿状と成す。これを従来周知のドクターブレード法やカレンダーロール法等のテープ成形技術により複数のセラミックグリーンシートを得る。次に、このセラミックグリーンシートに、ＷやＭｏ等の高融点金属粉末に適当な有機バインダー、可塑剤、溶剤等を添加混合して得た金属ペーストを、スクリーン印刷法等の厚膜形成技術により印刷塗布して、線路導体５ｃとなるメタライズ層を所定パターンに形成する。また、入出力端子５をＡｇロウ等を介して基体１にロウ付けするために、入出力端子５の基体１との接合部にも、線路導体５ｃと同様にしてメタライズ層を所定パターンに形成する。しかる後、セラミックグリーンシートを複数枚積層し、これを還元雰囲気中約１６００℃の温度で焼成することにより製作される。
【００３３】
また、入出力端子５は、その表面に基体１との接合のためのメタライズ層を形成せずに焼成し、焼成後に入出力端子５の表面をスライス切断加工あるいは研磨加工した後、そのスライス切断面あるいは研磨面にＷやＭｏ等を主成分とする金属ペーストをスクリーン印刷法等の厚膜形成技術により印刷塗布して、これを還元雰囲気中約１３００℃の温度で焼成することにより製作してもよい。これにより、入出力端子５の表面を平坦にすることができ、基体１との接合をより良好にすることができる。
【００３４】
そして、光半導体素子２と線路導体５ｃとは平板部５ｂの一主面においてボンディングワイヤ９等を介して電気的に接続される。本発明の入出力端子５を用いることにより、従来のように光半導体素子２と外部接続用ピンとをボンディングワイヤ９により接続する必要はなく、線路導体５ｃと光半導体素子２とを同じ平板部５ｂ上の一主面においてボンディングワイヤ９により接続することができるため、ボンディングワイヤ９による電気的な接続が容易となるとともに、ボンディングワイヤ９の長さも短くすることができ、ボンディングワイヤ９のインダクタンスを小さくして高周波信号の伝送効率を向上させることができる。
【００３５】
また、入出力端子５は、図２（ａ）に示すように、平板部５ｂの下面に金属板１０がＡｇロウ等のロウ材により接合されていてもよい。この構成により、光半導体素子２の作動時に発生した熱を金属板１０を介して光半導体装置の外部に効率よく放熱させることができる。従って、光半導体素子２が蓄熱して温度が上昇するのを抑制し、光半導体素子２を正常に作動させることができる。
【００３６】
金属板１０は、略長方形の形状で、Ｆｅ−Ｎｉ−Ｃｏ合金やＣｕ−Ｗ合金等の金属から成り、そのインゴットに圧延加工や打ち抜き加工等の従来周知の金属加工法を施すことによって所定形状に製作される。
【００３７】
また、平板部５ｂは、金属板１０が接合されている場合、図２（ａ）に示すように、光半導体素子２の載置部を基台８として分離した状態で金属板１０上に接合されていてもよい。これにより、例えば、基台８をＡｌＮ質焼結体等の熱伝導性のよい誘電体で形成して、光半導体素子２で発生した熱を良好に金属板１０に伝導させて光半導体素子２を効率よく放熱させることができる。
【００３８】
さらに、基台８に載置される光半導体素子２と線路導体５ｃとは、ボンディングワイヤ９を介して電気的に接続されている。あるいは、基台８上に線路導体５ｃと同様の方法で形成した線路導体８ａをボンディングワイヤ９を介して線路導体５ｃおよび光半導体素子２にそれぞれ電気的に接続してもよい。この場合、ボンディングワイヤ９の長さを短くして、そのインダクタンスを小さくするという観点から、線路導体５ｃの上面と線路導体８ａの上面とが平板部５ｂの一主面に対して同じ高さになっていることが好ましい。また、線路導体５ｃと線路導体８ａとが、ボンディングワイヤ９を使用せずに板状の金属片や金属棒により電気的に接続されていてもよく、この場合、よりインダクタンスを小さくすることができるとともにインピーダンスの調整も容易となる。
【００３９】
また、基体１の上側主面の外周部には、上端面３ａの略中央部に貫通孔３ｂが形成され下端３ｃが開かれた筒状である蓋体３が設けられる。蓋体３の下端３ｃは、鉛（Ｐｂ）−錫（Ｓｎ）半田等の半田による半田付けや溶接等によって基体１と気密に接合される。なお、下端３ｃは、基体１との接合面積を大きくして、基体１と蓋体３とで構成される容器内部の気密信頼性を向上させるために、図１に示すような鍔状であることが好ましい。
【００４０】
蓋体３は、断面形状（横断面形状）が円形または長方形等の多角形の筒状であり、Ｆｅ−Ｎｉ−Ｃｏ合金等の金属から成り、そのインゴットに圧延加工や打ち抜き加工等の従来周知の金属加工法を施すことによって所定形状に製作される。なお、蓋体３は、筒状部と上端面３ａが個々に製作され、それらをロウ付け、半田付け、溶接等によって接合したものであってもよい。
【００４１】
蓋体３には、貫通孔３ｂを塞ぐように貫通孔３ｂの上端面３ａ側開口の周囲に、透光性部材４がガラス接合や半田付け等により気密に接合される。透光性部材４は、ガラスやサファイア等から成る円板状，レンズ状，球状または半球状等のものであり、球状の場合表面の全周にわたる帯状部で、円板状やレンズ状の場合一主面の外周部で、半球状の場合平面部の外周部で蓋体３に接合される。
【００４２】
また、光ファイバ６は、Ｆｅ−Ｎｉ−Ｃｏ合金等の金属から成る略円筒状の固定部材７の上端面に固定されており、固定部材７の下端面が蓋体３の外周の鍔状部にレーザ溶接法等の溶接によって接合される。光ファイバ６が固定部材７を介して透光性部材４の上方に固定されることによって、製品としての光半導体装置となる。これにより、光ファイバ６を介して内部に収容する光半導体素子２と外部との光信号の授受が可能となる。
【００４３】
本発明において、透光性部材４は貫通孔３ｂの上端面３ａ側開口の周囲に接合されるのが好ましく、この場合以下の点で有利である。即ち、蓋体３の外周の鍔状部に固定部材７を溶接する際の熱が蓋体３に局所的に加わり、蓋体３の透光性部材４との接合面に熱膨張による引っ張り応力が加わると、透光性部材４が蓋体３から剥がれ易くなるが、光半導体装置は内部を気密にするため外側から内側に気圧が加わり易く、気圧によって透光性部材４が蓋体３に押し付けられて剥がれにくくなる。一方、透光性部材４が貫通孔３ｂの上端面３ａの裏面側開口の周囲に接合されていると、熱膨張による応力によって透光性部材４を剥がそうとする引っ張り応力と気圧による圧力とが、透光性部材４が蓋体３から容易に外れてしまうこととなる。
【００４４】
本発明の光半導体装置は、光半導体素子２の電極を外部電気回路に電気的に接続し、製品としての光半導体装置となる。この光半導体装置は、例えば外部電気回路から供給される電気信号によって光半導体素子２にレーザ光等の光を励起させ、この光を透光性部材４、光ファイバ６の順に透過させ、光ファイバ６を介して外部に伝送することによって、高速光通信等に使用される光半導体装置として機能する。
【００４５】
なお、本発明は上記実施の形態に限定されるものではなく、本発明の要旨を逸脱しない範囲内であれば種々の変更を施すことは何等差し支えない。
【００４６】
【発明の効果】
本発明の光半導体素子収納用パッケージは、金属から成る板状の基体は貫通穴の他方の長辺側の上側主面と内面との間に段差が形成されており、立壁部の段差側の面に一側面が接合されるとともに段差の底面に他側面側の下面が接合されて立壁部と段差との間の隙間を塞ぐ略長方形の金属板が設けられていることにより、貫通穴に入出力端子を嵌着する際に、金属板を貫通穴の段差に載置した状態で入出力端子を貫通穴に挿入し、金属板を段差の底面で入出力端子の幅に合わせてスライドさせて位置を調整した後、貫通穴を塞ぐように金属板を接合することができる。このように、基体の段差の底面に他側面側の下面が載置されている金属板は、接合される前に段差の底面でスライドさせて位置調整できるので、金属加工の精度によって貫通穴の大きさがばらついていたり、焼成時の収縮ばらつきにより入出力端子の寸法がばらついていても、入出力端子と貫通穴の長辺部におけるクリアランス（間隔）を確実に塞ぐことができるので、基体の入出力端子接合部における気密性を向上させることができる。
【００４７】
また、金属板は基体よりも薄くすることができ、金属板と入出力端子との接合部で入出力端子が金属板に接する面積を小さくできるので、金属板の部位で入出力端子にかかる基体との熱膨張差による応力を緩和させ、入出力端子にクラック等の破損が生じるのを防止でき、入出力端子の接合部における気密性をより向上させることができる。
【００４８】
さらに、貫通穴に、一主面に一辺から対向する他辺にかけて線路導体が形成されるとともに一主面の一端部に光半導体素子の載置部が設けられた誘電体から成る平板部およびこの平板部の一主面に線路導体の一部を間に挟んで接合された誘電体から成る立壁部から成る入出力端子が、一端部を基体と蓋体との間に位置させて嵌着されていることから、入出力端子に微細な間隔をもって電極パッド、配線導体および内部配線等を多数形成することができ、その結果、光半導体素子やモニタ用ＰＤだけでなく、光半導体素子を駆動するためのドライバＩＣ等を入出力端子の表面に設けることができ、信号入出力および光半導体素子の駆動や制御を入出力端子で行なうことができる。従って、外部電気回路に設けられていたドライバＩＣ等を光半導体装置の内部や入出力端子の外側に実装し高集積化できることから、光半導体素子を駆動させるための装置全体を小型化できる。
【００４９】
また、貫通穴に入出力端子が嵌着されていることによって、従来のガラス接合された外部接続用ピンに比較して、外部接続用ピンの接合部にクラック等の破損が生じて光半導体装置内部の気密が破れるのを有効に抑制することができる。従って、外部接続用ピンをガラス等の接合材を介して基体の貫通孔に接合した従来の構造に比べ気密信頼性が大幅に向上する。また外部接続用ピンを介すことなく、入出力端子の線路導体で外部電気回路に接続できるため、高周波信号が反射等して伝送損失が生じるのを抑制し、高周波信号の伝送効率を大幅に改善することができる。
【００５０】
さらに、従来のように光半導体素子と外部接続用ピンとをボンディングワイヤにより接続する必要はなく、線路導体と光半導体素子とを同じ平板部の一主面上においてボンディングワイヤにより接続することができるため、ボンディングワイヤによる電気的な接続が容易となるとともに、ボンディングワイヤの長さも短くすることができボンディングワイヤのインダクタンスを小さくして高周波信号の伝送効率を向上させることができる。
【００５１】
本発明の光半導体装置は、本発明の光半導体パッケージと、載置部に基台を介して載置固定されるとともに入出力端子に電気的に接続された光半導体素子と、基体の上側主面に接合された蓋体とを具備したことにより、上記本発明の光半導体パッケージを用いた高性能で信頼性の高いものとなる。
【図面の簡単な説明】
【図１】（ａ）は本発明の光半導体装置について実施の形態の例を示す断面図であり、（ｂ）は（ａ）の要部拡大下面図である。
【図２】（ａ）は本発明の光半導体装置について実施の形態の他の例を示す断面図であり、（ｂ）は（ａ）の要部拡大下面図である。
【図３】従来の光半導体装置の例を示す断面図である。
【符号の説明】
１：基体
１ａ：貫通穴
１ｂ：段差
１ｃ：金属板
２：光半導体素子
３：蓋体
３ａ：上端面
３ｂ：貫通孔
４：透光性部材
５：入出力素子
５ａ：立壁部
５ｂ：平板部
５ｃ：線路導体[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical semiconductor device housing package for housing an optical semiconductor device such as a semiconductor laser (LD) and a photodiode (PD), and an optical semiconductor device.
[0002]
[Prior art]
FIG. 3 shows an example of an optical semiconductor device in which an optical semiconductor element such as a semiconductor laser (LD) or a photodiode (PD) that operates at a high frequency in a conventional field such as optical communication is hermetically sealed and housed. FIG. 3 is a sectional view of an optical semiconductor device in which an LD is housed. In the figure, 21 is a base, 22 is an optical semiconductor element, 23 is a metal lid, 24 is a translucent member, and 26 is an optical fiber.
[0003]
The base 21 is made of a metal such as an iron (Fe) -nickel (Ni) -cobalt (Co) alloy or a copper (Cu) -tungsten (W) alloy. Is mounted and fixed on the upper main surface of the base 21 with the light emitting portion facing upward via a substantially rectangular parallelepiped base 28 made of ceramics such as alumina (Al 2 O 3 ) sintered body. With this configuration, an optical signal emitted from the optical semiconductor element 22 is emitted above the base 21. The base 21 has a through hole 21a penetrating between the upper and lower main surfaces for inserting the external connection pin 25 made of a metal such as an Fe-Ni alloy or an Fe-Ni-Co alloy. An external connection pin 25 as a terminal for conducting inside and outside the optical semiconductor device is inserted into the hole 21a, and a gap between the external connection pin 25 and the through hole 21a is filled with a bonding material made of a dielectric material such as glass. 21 and the external connection pins 25 are hermetically bonded. Thus, the external connection pin 25 functions as a terminal that conducts inside and outside the optical semiconductor device.
[0004]
The electrodes of the optical semiconductor element 22 mounted on the base 28 are electrically connected to the tips of the external connection pins 25 on the optical semiconductor element 22 side via bonding wires 29 and the like.
[0005]
Further, it is joined to the outer peripheral portion of the upper main surface of the base 21 and has a cylindrical shape with the upper end closed and the lower end opened, and a through-hole 23b is formed substantially at the center of the upper end surface 23a. A lid 23 made of a metal such as an alloy is provided. The lower end 23c of the lid 23 has, for example, a flange shape as shown in FIG. 3, thereby increasing the bonding area between the base 21 and the lid 23, and the inside of the container formed of the base 21 and the lid 23. Airtight reliability is improved.
[0006]
Further, a light transmissive member 24 is joined around the opening on the upper end surface 23a side of the through hole 23b so as to close the through hole 23b. The translucent member 24 has a disk shape, a lens shape, a spherical shape or a hemispherical shape made of glass, sapphire, or the like, and is hermetically bonded to the lid 23 by glass bonding or soldering.
[0007]
The optical semiconductor element 22 is accommodated in a container mainly composed of such a base 21, a lid 23 and a translucent member 24 and hermetically sealed.
[0008]
Finally, a cylindrical metal fixing member 27 for fixing the optical fiber 26 is welded to the flange portion on the outer periphery of the lid 23, and the optical fiber 26 is inserted and fixed from the outside into the through hole on the upper surface of the fixing member 27. Then, it is fixed above the translucent member 24, and the outer end portion of the external connection pin 25 is electrically connected to an external electric circuit (not shown), so that an optical semiconductor device is obtained (for example, See Patent Document 1 below).
[0009]
This optical semiconductor device excites light such as laser light in the optical semiconductor element 22 by an electric signal supplied from an external electric circuit, transmits this light in the order of the light transmitting member 24 and the optical fiber 26, By transmitting the signal to the outside via the optical semiconductor device, the device functions as an optical semiconductor device used for high-speed optical communication or the like. In this case, a monitoring PD (not shown) for checking whether the optical signal is normally emitted from the optical semiconductor element 22 may be mounted. Alternatively, an optical signal transmitted from the outside via the optical fiber 26 is transmitted through the translucent member 24 and received by the optical semiconductor element 22, and the optical signal is converted into an electric signal. Function as an optical semiconductor device used for
[0010]
[Patent Document 1]
JP 2001-183369 A
[Problems to be solved by the invention]
However, in the above-described conventional optical semiconductor device, since the external connection pins 25 are configured to be inserted into the through holes 21a of the base 21 and to be hermetically bonded via glass or the like, the external connection pins 25 have a minimum diameter dimension. There are restrictions such as a processing limit, a hole size of the through hole 21a, and a minimum processing limit of an interval between the adjacent through holes 21a. Therefore, a large area is required for inserting one external connection pin 25 into the base 21. Thus, there is a problem that the number of external connection pins 25 attached to the base 21 is limited to several.
[0012]
Further, the optical semiconductor device accommodates only the optical semiconductor element 22 such as an LD and a PD and a monitoring PD, and a driver IC for driving the optical semiconductor element 22 is accommodated in another semiconductor element accommodation package. It is necessary to electrically connect the driver IC and the optical semiconductor device via an external electric circuit, and there is a problem that the entire device for driving the optical semiconductor element 22 becomes large.
[0013]
In addition, since the terminal structure is such that the external connection pins 25 are merely bonded to the base 21 via a bonding material such as glass, when a stress is applied to the external connection pins 25 from the outside, the bonding material may be damaged such as a crack. This causes a problem that airtightness inside the optical semiconductor device is impaired.
[0014]
Further, it is difficult to make a portion of the external connection pin 25 that is not inserted into the through-hole 21a a signal line that matches the characteristic impedance, and a high-frequency signal transmitted through the external connection pin 25 is transmitted to the external connection pin 25. There is also a problem that transmission loss occurs due to reflection or the like, and high-frequency signals cannot be transmitted efficiently. In particular, when the frequency becomes higher than 2 GHz, the transmission efficiency tends to be remarkably deteriorated.
[0015]
In many LDs currently used as a light source of an optical signal, since the optical signal emits light from the side surface of the optical semiconductor element 22, in order to emit light in the direction of the optical fiber 26, the optical semiconductor element 22 is It must be mounted on a surface perpendicular to the upper main surface. Therefore, since the base 28 is provided on the upper main surface of the base 21 and the optical semiconductor element 22 is mounted on a surface perpendicular to the upper main surface of the base 21 of the base 28, the optical semiconductor element 22 is connected to the external connection. When connecting the pins 25 with the bonding wires 29, there is a problem that workability is poor and labor is required.
[0016]
Accordingly, the present invention has been completed in view of the above problems, and an object of the present invention is to increase the number of terminals attached to an optical semiconductor device to increase the number of components such as integrated circuit elements (ICs) housed therein, and A semiconductor device with high integration and multi-functionality, high-frequency signals can be transmitted efficiently, internal airtight reliability is improved, and optical semiconductor elements can operate normally and stably for a long time. It is in.
[0017]
[Means for Solving the Problems]
The optical semiconductor element housing package of the present invention has a plate-shaped base made of metal having a substantially rectangular through hole formed in a substantially central section and a through hole formed in a substantially central portion of an upper end surface. A cover body made of metal having a cylindrical shape with a lower end opened and having a lower end joined to an outer peripheral portion of an upper main surface of the base; and a light-transmissive joined around an upper end side opening of the through hole. The base has a line conductor formed in the through hole from one side to the other side facing one main surface, and an optical semiconductor element mounted on one end of the one main surface. An input / output terminal comprising a flat portion made of a dielectric provided with a portion and an upright wall portion made of a dielectric joined to the one main surface of the flat portion with a part of the line conductor interposed therebetween; Part is located between the base and the lid, and In the optical semiconductor element housing package fitted with the main surface having one long side of the through hole, the base is provided between the upper main surface and the inner surface on the other long side of the through hole. A gap is formed between the upright wall portion and the step by joining one side surface to the step side surface of the upright wall portion and joining the lower surface of the other side surface to the bottom surface of the step portion. And a substantially rectangular metal plate for closing is provided.
[0018]
In the package for housing an optical semiconductor element of the present invention, the plate-like base made of metal has a step formed between the upper main surface on the other long side of the through hole and the inner surface, and the step on the step side of the upright wall portion. One side is joined to the surface, and the lower surface of the other side is joined to the bottom of the step, and a substantially rectangular metal plate that closes the gap between the standing wall and the step is provided. When fitting the output terminal, insert the input / output terminal into the through hole with the metal plate placed on the step of the through hole, and slide the metal plate on the bottom of the step according to the width of the input / output terminal. After adjusting the position, the metal plate can be joined so as to close the through hole. In this manner, the metal plate on which the lower surface on the other side is placed on the bottom surface of the step of the base can be slid on the bottom surface of the step before joining, so that the through-hole can be adjusted by the precision of metal processing. Even if the size varies or the size of the input / output terminal varies due to shrinkage during firing, the clearance (interval) at the long side of the input / output terminal and the through hole can be reliably closed, so that the base The airtightness at the input / output terminal junction can be improved.
[0019]
Also, the metal plate can be made thinner than the base, and the area where the input / output terminal contacts the metal plate at the junction between the metal plate and the input / output terminal can be reduced. Stress due to the difference in thermal expansion between the input and output terminals can be prevented, and damage such as cracks can be prevented from occurring in the input and output terminals, and the airtightness at the junction of the input and output terminals can be further improved.
[0020]
Further, in the through hole, a line conductor is formed from one side to the other side opposite to the one main surface, and a flat plate portion made of a dielectric material in which a mounting portion of the optical semiconductor element is provided at one end of the one main surface, and An input / output terminal composed of a standing wall made of a dielectric joined to one main surface of the flat plate with a part of the line conductor interposed therebetween is fitted with one end positioned between the base and the lid. As a result, a large number of electrode pads, wiring conductors, internal wirings, and the like can be formed at minute intervals between the input and output terminals. As a result, not only the optical semiconductor element and the monitoring PD but also the optical semiconductor element are driven. A driver IC or the like can be provided on the surface of the input / output terminal, and signal input / output and driving and control of the optical semiconductor element can be performed at the input / output terminal. Therefore, since the driver IC and the like provided in the external electric circuit can be mounted inside the optical semiconductor device or outside the input / output terminals and can be highly integrated, the entire device for driving the optical semiconductor element can be downsized.
[0021]
Further, since the input / output terminals are fitted into the through holes, cracks and the like are generated at the joints of the external connection pins as compared with the conventional glass-bonded external connection pins, so that the optical semiconductor device is damaged. Breaking of the internal airtightness can be effectively suppressed. Therefore, the airtight reliability is greatly improved as compared with the conventional structure in which the external connection pins are joined to the through holes of the base via a joining material such as glass. In addition, since it is possible to connect to an external electric circuit with the line conductors of the input / output terminals without passing through the external connection pins, high-frequency signals are prevented from being reflected and transmission loss is generated, and transmission efficiency of high-frequency signals is greatly improved. Can be improved.
[0022]
Further, unlike the related art, it is not necessary to connect the optical semiconductor element and the external connection pin by a bonding wire, and the line conductor and the optical semiconductor element can be connected by the bonding wire on one main surface of the same flat plate portion. In addition, the electrical connection by the bonding wire is facilitated, the length of the bonding wire can be shortened, the inductance of the bonding wire can be reduced, and the transmission efficiency of a high-frequency signal can be improved.
[0023]
An optical semiconductor device according to the present invention includes an optical semiconductor package according to the present invention, an optical semiconductor element mounted and fixed to the mounting portion via a base, and electrically connected to an input / output terminal. And a lid joined to the upper main surface.
[0024]
With the above configuration, the optical semiconductor device of the present invention has high performance and high reliability using the optical semiconductor element housing package of the present invention.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
An optical semiconductor element storage package (hereinafter, also referred to as a package) and an optical semiconductor device of the present invention will be described in detail below. 1A is a cross-sectional view showing an example of an embodiment of an optical semiconductor device using the package of the present invention, FIG. 1B is an enlarged bottom view of a main part of FIG. 1A, and FIG. FIG. 2 is a sectional view showing another example of the embodiment of the optical semiconductor device of the present invention, and FIG. 2B is an enlarged bottom view of a main part of FIG. 2A. In these figures, 1 is a metal base, 2 is an optical semiconductor element, 3 is a metal lid, 4 is a translucent member, 5 is an input / output terminal, and 6 is an optical fiber.
[0026]
In the package of the present invention, a plate-shaped base 1 made of metal having a through hole 1a having a substantially rectangular cross section at a substantially central portion, and a through hole 3b formed at a substantially central portion of an upper end surface 3a. At the same time, the lower end 3c is formed in a cylindrical shape with the open end, and the lid 3 made of metal whose lower end 3c is joined to the outer peripheral portion of the upper main surface of the base 1 is joined to the periphery of the opening on the upper end surface 3a side of the through hole 3b. The base body 1 has a through hole 1a, a line conductor 5c formed on one main surface from one side to the opposite side, and an optical semiconductor on one end of one main surface. A flat plate portion 5b made of a dielectric on which the mounting portion of the element 2 is provided, and a standing wall portion 5a made of a dielectric joined to one main surface of the flat plate portion 5b with a part of the line conductor 5c interposed therebetween. The output terminal 5 has one end positioned between the base 1 and the lid 3 and The base 5b is fitted with the other main surface of the portion 5b on one long side of the through hole 1a, and the base is formed between the inner surface and the upper main surface on the other long side of the through hole 1a. Is formed, and one side surface is joined to the surface of the standing wall portion 5a on the side of the step 1b, and the lower surface of the other side surface is joined to the bottom surface of the step 1b to close the gap between the standing wall portion 5a and the step 1b. A substantially rectangular metal plate 1c is provided.
[0027]
The base 1 and the metal plate 1c of the present invention are manufactured into a predetermined shape by subjecting a metal ingot such as an Fe-Ni-Co alloy or a Cu-W alloy to a conventionally known metal working method such as rolling or punching. You. As shown in FIGS. 1 (b) and 2 (b), the base 1 has a through hole 1a having a substantially rectangular cross section at the center of the main surface. A metallized layer provided on the surface of the input / output terminal 5 is joined to the inner surface of the through hole 1a with a brazing material such as silver (Ag) brazing, so as to close the through hole 1a. 5 are hermetically bonded.
[0028]
With the metal plate 1c mounted and fixed on the bottom surface of the step 1b, the input / output terminal 5 is inserted into the through hole 1a while the metal plate 1c is placed on the step 1b of the through hole 1a, and the metal plate 1c is connected to the step 1b. After adjusting the position by sliding on the bottom surface according to the width of the input / output terminal 5, the metal plate 1c can be joined so as to cover the through hole 1a. As described above, since the position of the metal plate 1c can be adjusted by sliding on the bottom surface of the step 1b, the size of the through-hole 1a varies depending on the precision of metal working, and the height of the input / output terminal 5 due to shrinkage variation during firing. Even if the input / output terminals 5 vary, the clearance at the long sides of the input / output terminals 5 and the base 1 can be reliably closed, so that the airtightness at the junction between the input / output terminals 5 of the base 1 can be improved.
[0029]
Further, the metal plate 1c can be made thinner than the base 1, and the area where the input / output terminal 5 contacts the metal plate 1c at the joint between the metal plate 1c and the input / output terminal 5 can be made smaller than in the conventional case. The stress due to the difference in thermal expansion between the metal plate 1c and the terminal 5 can be reduced, and the input / output terminal 5 can be prevented from being damaged such as a crack. .
[0030]
In the metal plate 1c, it is preferable that the other side surface opposite to the upright wall portion 5a does not abut on the side surface of the step 1b so that there is a gap. In this case, a meniscus or pool of brazing material for joining the metal plate 1c is formed in the gap, and the joining strength is improved.
[0031]
As shown in FIG. 1A, the input / output terminal 5 of the present invention has a line conductor 5c formed on one main surface from one side to the opposite side, and the optical semiconductor element 2 at one end of one main surface. It is composed of a flat plate portion 5b provided with a mounting portion and an upright wall portion 5a joined to one main surface of the flat plate portion 5b with a part of the line conductor 5c interposed therebetween. The flat plate portion 5b and the standing wall portion 5a are made of a dielectric material such as an Al 2 O 3 sintered body (alumina ceramics), an AlN sintered body, a 3Al 2 O 3 .2SiO 2 sintered body, and a line conductor. 5c is made of a metallized layer such as tungsten (W) or molybdenum (Mo).
[0032]
Such an input / output terminal 5 is manufactured as follows. For example, when the flat plate portion 5b and the vertical wall portion 5a are made of an Al 2 O 3 sintered body, firstly, it is suitable for a raw material powder such as aluminum oxide, silicon oxide (SiO 2 ), magnesium oxide (MgO), and calcium oxide (CaO). An organic binder, a plasticizer, a solvent and the like are added and mixed to form a slurry. A plurality of ceramic green sheets are obtained by a tape forming technique such as a doctor blade method and a calender roll method, which are well known in the art. Next, a metal paste obtained by adding a suitable organic binder, a plasticizer, a solvent, and the like to a high melting point metal powder such as W or Mo to the ceramic green sheet is mixed with a thick film forming technique such as a screen printing method. By printing and applying, a metallized layer to be the line conductor 5c is formed in a predetermined pattern. Further, in order to braze the input / output terminal 5 to the base 1 via an Ag brazing or the like, a metallized layer is formed in a predetermined pattern at the joint between the input / output terminal 5 and the base 1, similarly to the line conductor 5c. I do. Thereafter, a plurality of ceramic green sheets are laminated and fired at a temperature of about 1600 ° C. in a reducing atmosphere.
[0033]
The input / output terminals 5 are baked without forming a metallized layer for bonding to the substrate 1 on the surface, and after sintering, the surface of the input / output terminals 5 is sliced or polished, and then sliced. A metal paste containing W or Mo as a main component is printed and applied on a surface or a polished surface by a thick film forming technique such as a screen printing method, and the resultant is baked at a temperature of about 1300 ° C. in a reducing atmosphere. Is also good. Thereby, the surface of the input / output terminal 5 can be flattened, and the bonding with the base 1 can be further improved.
[0034]
The optical semiconductor element 2 and the line conductor 5c are electrically connected to each other via a bonding wire 9 or the like on one main surface of the flat plate portion 5b. By using the input / output terminal 5 of the present invention, there is no need to connect the optical semiconductor element 2 and the external connection pins with the bonding wires 9 unlike the conventional case, and the line conductor 5c and the optical semiconductor element 2 are connected to the same flat plate portion 5b. Since the connection can be made by the bonding wire 9 on the upper main surface, the electrical connection by the bonding wire 9 becomes easy, and the length of the bonding wire 9 can be shortened, so that the inductance of the bonding wire 9 is reduced. As a result, the transmission efficiency of the high-frequency signal can be improved.
[0035]
Further, as shown in FIG. 2A, the input / output terminal 5 may be such that the metal plate 10 is joined to the lower surface of the flat plate portion 5b by a brazing material such as Ag brazing. With this configuration, heat generated during operation of the optical semiconductor element 2 can be efficiently radiated to the outside of the optical semiconductor device via the metal plate 10. Therefore, it is possible to prevent the optical semiconductor element 2 from storing heat and increase the temperature, and to operate the optical semiconductor element 2 normally.
[0036]
The metal plate 10 has a substantially rectangular shape and is made of a metal such as an Fe-Ni-Co alloy or a Cu-W alloy, and has a predetermined shape by subjecting the ingot to a conventionally known metal working method such as rolling or punching. It is produced in.
[0037]
When the metal plate 10 is bonded, the flat plate portion 5b is bonded to the metal plate 10 in a state where the mounting portion of the optical semiconductor element 2 is separated as a base 8 as shown in FIG. It may be. Thereby, for example, the base 8 is formed of a dielectric material having good thermal conductivity such as an AlN sintered body, and the heat generated in the optical semiconductor element 2 is satisfactorily conducted to the metal plate 10 so that the optical semiconductor element 2 Can be efficiently dissipated.
[0038]
Further, the optical semiconductor element 2 mounted on the base 8 and the line conductor 5c are electrically connected via a bonding wire 9. Alternatively, the line conductor 8 a formed on the base 8 in the same manner as the line conductor 5 c may be electrically connected to the line conductor 5 c and the optical semiconductor element 2 via the bonding wire 9. In this case, from the viewpoint of reducing the length of the bonding wire 9 and reducing its inductance, the upper surface of the line conductor 5c and the upper surface of the line conductor 8a have the same height with respect to one main surface of the flat plate portion 5b. It is preferred that it is. Further, the line conductor 5c and the line conductor 8a may be electrically connected by a plate-shaped metal piece or metal bar without using the bonding wire 9, and in this case, the inductance can be further reduced. At the same time, the impedance can be easily adjusted.
[0039]
On the outer peripheral portion of the upper main surface of the base 1, there is provided a cylindrical lid 3 having a through hole 3b formed at a substantially central portion of the upper end surface 3a and an open lower end 3c. The lower end 3c of the lid 3 is hermetically joined to the base 1 by soldering or welding with solder such as lead (Pb) -tin (Sn) solder. The lower end 3c has a flange shape as shown in FIG. 1 in order to increase the bonding area with the base 1 and improve the airtight reliability inside the container formed by the base 1 and the lid 3. Is preferred.
[0040]
The lid 3 is a polygonal cylinder having a cross-sectional shape (cross-sectional shape) such as a circle or a rectangle, and is made of a metal such as an Fe-Ni-Co alloy. Is manufactured in a predetermined shape by applying the metal working method of (1). Note that the lid 3 may be one in which the cylindrical portion and the upper end surface 3a are individually manufactured, and they are joined by brazing, soldering, welding, or the like.
[0041]
A light-transmissive member 4 is hermetically joined to the lid 3 around the opening on the upper end surface 3a side of the through hole 3b so as to close the through hole 3b by glass joining, soldering, or the like. The translucent member 4 has a disk shape, a lens shape, a spherical shape or a hemispherical shape made of glass, sapphire, or the like. In the case of a hemisphere, the outer peripheral portion of one principal surface is joined to the lid 3 at the outer peripheral portion of the flat surface portion.
[0042]
The optical fiber 6 is fixed to an upper end surface of a substantially cylindrical fixing member 7 made of a metal such as an Fe—Ni—Co alloy, and the lower end surface of the fixing member 7 is a flange-shaped portion on the outer periphery of the lid 3. Are joined by welding such as laser welding. By fixing the optical fiber 6 above the translucent member 4 via the fixing member 7, an optical semiconductor device as a product is obtained. Thus, it becomes possible to exchange optical signals between the optical semiconductor element 2 housed inside and the outside via the optical fiber 6.
[0043]
In the present invention, the translucent member 4 is preferably joined to the periphery of the opening on the upper end surface 3a side of the through hole 3b, which is advantageous in the following points. That is, heat generated when the fixing member 7 is welded to the flange portion on the outer periphery of the lid 3 is locally applied to the lid 3, and a tensile stress due to thermal expansion is applied to the joint surface of the lid 3 with the light transmitting member 4. Is applied, the translucent member 4 is easily peeled off from the lid 3, but the optical semiconductor device is apt to be pressurized from the outside to the inside to make the inside airtight, and the translucent member 4 is applied to the lid 3 by the air pressure. It is hard to be peeled by being pressed. On the other hand, when the translucent member 4 is joined to the periphery of the back side opening of the upper end surface 3a of the through hole 3b, the tensile stress for peeling the translucent member 4 due to the stress due to thermal expansion and the pressure due to the atmospheric pressure However, the light transmitting member 4 is easily detached from the lid 3.
[0044]
The optical semiconductor device of the present invention electrically connects the electrodes of the optical semiconductor element 2 to an external electric circuit, and becomes an optical semiconductor device as a product. This optical semiconductor device excites light such as laser light in the optical semiconductor element 2 by an electric signal supplied from, for example, an external electric circuit, and transmits the light through the light transmitting member 4 and the optical fiber 6 in this order. By transmitting the signal to the outside via the device 6, the device functions as an optical semiconductor device used for high-speed optical communication or the like.
[0045]
The present invention is not limited to the above-described embodiment, and various changes may be made without departing from the scope of the present invention.
[0046]
【The invention's effect】
In the package for housing an optical semiconductor element of the present invention, the plate-like base made of metal has a step formed between the upper main surface on the other long side of the through hole and the inner surface, and the step on the step side of the upright wall portion. One side is joined to the surface, and the lower surface on the other side is joined to the bottom of the step, and a substantially rectangular metal plate that closes the gap between the standing wall and the step is provided. When fitting the output terminal, insert the input / output terminal into the through hole with the metal plate placed on the step of the through hole, and slide the metal plate on the bottom of the step according to the width of the input / output terminal. After adjusting the position, the metal plate can be joined so as to close the through hole. In this manner, the metal plate on which the lower surface on the other side is placed on the bottom surface of the step of the base can be slid on the bottom surface of the step before joining, so that the through-hole can be adjusted by the precision of metal processing. Even if the size varies or the size of the input / output terminal varies due to shrinkage during firing, the clearance (interval) at the long side of the input / output terminal and the through hole can be reliably closed, so that the base The airtightness at the input / output terminal junction can be improved.
[0047]
Also, the metal plate can be made thinner than the base, and the area where the input / output terminal contacts the metal plate at the junction between the metal plate and the input / output terminal can be reduced. Stress due to the difference in thermal expansion between the input and output terminals can be prevented, and damage such as cracks can be prevented from occurring in the input and output terminals, and the airtightness at the junction of the input and output terminals can be further improved.
[0048]
Further, in the through hole, a line conductor is formed from one side to the other side opposite to the one main surface, and a flat plate portion made of a dielectric material in which a mounting portion of the optical semiconductor element is provided at one end of the one main surface, and An input / output terminal composed of a standing wall made of a dielectric joined to one main surface of the flat plate with a part of the line conductor interposed therebetween is fitted with one end positioned between the base and the lid. As a result, a large number of electrode pads, wiring conductors, internal wirings, and the like can be formed at minute intervals between the input and output terminals. As a result, not only the optical semiconductor element and the monitoring PD but also the optical semiconductor element are driven. A driver IC or the like can be provided on the surface of the input / output terminal, and signal input / output and driving and control of the optical semiconductor element can be performed at the input / output terminal. Therefore, since the driver IC and the like provided in the external electric circuit can be mounted inside the optical semiconductor device or outside the input / output terminals and can be highly integrated, the entire device for driving the optical semiconductor element can be downsized.
[0049]
Further, since the input / output terminals are fitted into the through holes, cracks and the like are generated at the joints of the external connection pins as compared with the conventional glass-bonded external connection pins, so that the optical semiconductor device is damaged. Breaking of the internal airtightness can be effectively suppressed. Therefore, the airtight reliability is greatly improved as compared with the conventional structure in which the external connection pins are joined to the through holes of the base via a joining material such as glass. In addition, since it is possible to connect to an external electric circuit with the line conductors of the input / output terminals without passing through the external connection pins, high-frequency signals are prevented from being reflected and transmission loss is generated, and transmission efficiency of high-frequency signals is greatly improved. Can be improved.
[0050]
Further, unlike the related art, it is not necessary to connect the optical semiconductor element and the external connection pin by a bonding wire, and the line conductor and the optical semiconductor element can be connected by the bonding wire on one main surface of the same flat plate portion. In addition, the electrical connection by the bonding wire is facilitated, the length of the bonding wire can be shortened, the inductance of the bonding wire can be reduced, and the transmission efficiency of a high-frequency signal can be improved.
[0051]
An optical semiconductor device of the present invention includes an optical semiconductor package of the present invention, an optical semiconductor element mounted and fixed to a mounting portion via a base, and electrically connected to an input / output terminal. By providing the lid joined to the surface, high performance and high reliability using the optical semiconductor package of the present invention can be obtained.
[Brief description of the drawings]
1A is a cross-sectional view showing an example of an embodiment of an optical semiconductor device of the present invention, and FIG. 1B is an enlarged bottom view of a main part of FIG.
2A is a cross-sectional view illustrating another example of the embodiment of the optical semiconductor device of the present invention, and FIG. 2B is an enlarged bottom view of the main part of FIG.
FIG. 3 is a cross-sectional view illustrating an example of a conventional optical semiconductor device.
[Explanation of symbols]
1: base 1a: through hole 1b: step 1c: metal plate 2: optical semiconductor element 3: lid 3a: upper end surface 3b: through hole 4: translucent member 5: input / output element 5a: standing wall 5b: flat plate 5c: line conductor
