【０００１】
【発明の属する技術分野】
本発明は、光通信等の分野に用いられる光半導体素子を収納するための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７に示す。図７は光半導体素子としてＬＤを内部に収納した光半導体装置の断面図である。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、２５は外部接続用ピン、２６は光ファイバである。これらの基体２１と外部接続用ピン２５とで光半導体素子収納用パッケージが基本的に構成される。また、光半導体素子収納用パッケージに光半導体素子２２を搭載し、透光性部材２４が接合された蓋体２３を接合することにより光半導体装置となる。
【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７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および外部接続用ピン２５から主に構成される光半導体素子収納用パッケージに光半導体素子２２を搭載し、透光性部材２４が接合された蓋体２３を接合して気密に封止す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）。
【０００８】
そして、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。これにより、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。また、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。
【０００９】
【特許文献１】
特開２０００−１８３３６９号公報
【００１０】
【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。
【００１１】
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。
【００１２】
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。
【００１３】
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。
【００１４】
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。
【００１５】
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。
【００１６】
【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、中央部を通る直線状の分割線で二分割された金属板から成る板部材がそれらの分割面同士で接合されて成るとともに前記中央部の接合線上に該接合線に長辺が略平行とされた断面形状が略長方形の貫通穴が形成されている基体と、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てい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り、前記貫通穴に嵌着された入出力端子と、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ており、前記貫通孔の上端面側開口の周囲に透光性部材が接合され、前記基体の上側主面の外周部に、前記一端部を前記透光性部材に対向させて覆うようにその下端で接合される金属製の蓋体とを具備することを特徴とする。
【００１７】
本発明の光半導体素子収納用パッケージは、中央部を通る直線状の分割線で二分割された金属板から成る板部材がそれらの分割面同士で接合されて成るとともに中央部の接合線上にこの接合線に長辺が略平行とされた断面形状が略長方形の貫通穴が形成されている基体を具備したことから、この貫通穴に入出力端子を嵌着する際、入出力端子を二分割された２枚の板部材の間の貫通穴の部位に挟み込んでおき、板部材と入出力端子との接合面に圧力を加えた状態でこれらを一体的に接合することができるので、基体の入出力端子部における気密性を向上させることができる。また、従来のように一枚の基体に貫通穴を形成するよりも、２分割された板部材に切り欠き部を形成する方が金属加工の加工精度を向上できるという利点もある。
【００１８】
また、基体の板部材を互いに接合する前に、入出力端子を貫通穴と成る板部材の切り欠き部に嵌め込むことができるため、従来のように入出力端子を貫通穴に挿入する必要がなく、従って、入出力端子と貫通穴の内面との間の引っ掛かりをなくすことができる。その結果、入出力端子と貫通穴の寸法をより近づけることが可能となり、入出力端子と貫通穴との間の隙間を非常に小さくして気密性をより向上させることができる。さらに、板部材の分割面にロウ材のプリフォームを万遍なく設けておき接合することができるので、板部材同士の間や板部材と入出力端子との間の隙間をロウ材で良好に充填することができ、これらの接合強度および気密性を向上させることができる。
【００１９】
また、上記の貫通穴に、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り、貫通穴に嵌着された入出力端子を具備することから、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この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することができることから、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。
【００２０】
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基板に接続することができるため、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。
【００２１】
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。
【００２２】
本発明の光半導体素子収納用パッケージにおいて、好ましくは、前記蓋体は前記基体の上側主面の外周部に金属から成る環状部材を介して接合されていることを特徴とする。
【００２３】
本発明の光半導体素子収納用パッケージは、蓋体が基体の上側主面の外周部に金属から成る環状部材を介して接合されていることから、基体を構成する板部材同士の厚み方向の接合ずれにより板部材同士の間に段差が生じた場合でも、環状部材を基体の上側主面にロウ付けすることにより、平坦な環状部材の上側主面と蓋体の下端とを隙間なく接触させることができる。その結果、環状部材の上側主面と蓋体の下端とを溶接法によってより強固に接合することができ、光半導体素子収納用パッケージの気密性を向上させることが可能となる。
【００２４】
本発明の光半導体素子収納用パッケージにおいて、好ましくは、前記環状部材は、外周端が前記基体の外周端よりも全周にわたって外側に突出していることを特徴とする。
【００２５】
本発明の光半導体素子収納用パッケージは、環状部材の外周端が基体の外周端よりも全周にわたって外側に突出していることから、蓋体を環状部材に接合する際に発生した応力を環状部材の基体から外側にはみ出した部分で吸収することにより、基体に熱応力が伝わるのを有効に抑制することができる。即ち、環状部材の上面に蓋体をシーム溶接法等により加熱して接合した後の冷却時に、蓋体の露出した上面は急速に冷却されて収縮しようとするので、蓋体の上面と環状部材との接合部とに温度差が生じて蓋体および環状部材が上側に反ろうとする応力が生じるが、この応力を環状部材の基体からはみ出した部分が適度に変形して吸収することによって基体に伝え難くすることができる。
【００２６】
本発明の光半導体装置は、上記の光半導体素子収納用パッケージの前記載置部に光半導体素子がその受光部または発光部を前記透光性部材に対向させて載置固定されているとともに前記線路導体に電気的に接続され、前記基体の上側主面の外周部に前記蓋体の下端が接合されていることを特徴とする。
【００２７】
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周波伝送特性および気密信頼性の優れたものとなる。
【００２８】
【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〜図６は本発明の光半導体装置について実施の形態の各種例を示すものであり、これらの図で（ａ）は本発明の光半導体装置の断面図、（ｂ）は本発明の光半導体装置の下面図である。
【００２９】
図１〜図６において、１は基体、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、１１は環状部材である。これら基体１および入出力端子５で光半導体素子収納用パッケージが基本的に構成される。また、光半導体素子収納用パッケージに光半導体素子２を搭載し、透光性部材４が接合された蓋体３を接合することにより光半導体装置となる。
【００３０】
本発明の光半導体素子収納用パッケージは、中央部を通る直線状の分割線で二分割された金属板から成る板部材１ｂ，１ｃがそれらの分割面同士で接合されて成るとともに中央部の接合線上にこの接合線に長辺が略平行とされた断面形状が略長方形の貫通穴１ａが形成されている基体１と、一主面に一辺から対向する他辺にかけて線路導体５ｃが形成されてい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誘電体から成る立壁部５ａから成り、貫通穴１ａに嵌着された入出力端子５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ており、貫通孔３ｂの上端面３ａ側開口の周囲に透光性部材４が接合され、基体１の上側主面の外周部に、一端部を透光性部材４に対向させて覆うようにその下端３ｃで接合される金属製の蓋体３とを具備している構成である。
【００３１】
本発明の基体１は、略円板状、略長方形等の平板状であり、中央部を通る直線状の分割線で二分割された金属板から成る板部材１ｂ，１ｃがそれらの分割面同士で接合されて成る。このような板部材１ｂ，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。
【００３２】
また、基体１には、図１〜図６の（ｂ）に示すように、中央部の接合線上にこの接合線に長辺が略平行とされた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。
【００３３】
貫通穴１ａは、一方の、あるいは両方の板部材１ｂ，１ｃの接合線の略中央に切り欠き部を形成した後、これらの板部材１ｂ，１ｃをそれらの分割面同士でＡｇロウ等のロウ材を介して接合することで、一方の板部材１ｂ（１ｃ）の切り欠き部の開放部が他方によって閉じられることにより、または板部材１ｂ，１ｃの双方の切り欠き部の開放部が互いに閉じられることにより形成されている。
【００３４】
貫通穴１ａをこのような構成にすることにより、貫通穴１ａに入出力端子５を嵌着する際、入出力端子５を二分割された２枚の板部材１ｂ，１ｃの間の貫通穴１ａの部位に挟み込んでおき、板部材１ｂ，１ｃと入出力端子５との接合面に圧力を加えた状態でこれらを一体的に接合することができるので、基体１の入出力端子５部における気密性を向上させることができる。また、従来のように一枚の基体１に貫通穴１ａを形成するよりも、２分割された板部材１ｂ，１ｃに切り欠き部を形成する方が金属加工の加工精度を向上できるという利点もある。
【００３５】
また、基体１の板部材１ｂ，１ｃを互いに接合する前に、入出力端子５を貫通穴１ａと成る板部材１ｂ，１ｃの切り欠き部に嵌め込むことができるため、従来のように入出力端子５を貫通穴１ａに挿入する必要がなく、従って、入出力端子５と貫通穴１ａの内面との間の引っ掛かりをなくすことができる。その結果、入出力端子５と貫通穴１ａの寸法をより近づけることが可能となり、入出力端子５と貫通穴１ａとの間の隙間を非常に小さくして気密性をより向上させることができる。さらに、板部材１ｂ，１ｃの分割面にロウ材のプリフォームを万遍なく設けておき接合することができるので、板部材１ｂ，１ｃ同士の間や板部材１ｂ，１ｃと入出力端子５との間の隙間をロウ材で良好に充填することができ、これらの接合強度および気密性を向上させることができる。
【００３６】
好ましくは、図１（ｂ），図３（ｂ），図５（ｂ）に示すように、基体１は入出力端子５の立壁部５ａの上面を通る直線，または入出力端子５の平板部５ｂの下面を通る直線で、板部材１ｂ，１ｃに分割されているのがよい。これにより、入出力端子５と板部材１ｂ，１ｃ、および板部材１ｂ，１ｃ同士をＡｇロウ等のロウ材を介して接合する際、接合時の圧力により板部材１ｂ，１ｃと入出力端子５との間から流れ出たロウ材を、板部材１ｂ，１ｃ同士の接合部に流れ込み易くすることができ、入出力端子５と板部材１ｂ，１ｃとの接合部、および板部材１ｂ，１ｃ同士の接合部に連続したロウ材のメニスカスを形成することが可能となる。その結果、入出力端子５と板部材１ｂ，１ｃとの接合強度、および板部材１ｂ，１ｃ同士の接合強度を向上させることができるとともに光半導体装置内部の気密性をより良好にすることができる。
【００３７】
本発明の入出力端子５は、図１（ａ），図３（ａ），図５（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，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。
【００３８】
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、タングステン（Ｗ）やモリブデン（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。
【００３９】
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。
【００４０】
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。
【００４１】
また、入出力端子５は、図２（ａ），図４（ａ），図６（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。
【００４２】
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。
【００４３】
また、平板部５ｂは、金属板１０が接合されている場合、図２（ａ），図４（ａ），図６（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。
【００４４】
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。
【００４５】
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。
【００４６】
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。
【００４７】
また、蓋体３は、図３〜図６の（ａ）に示すように基体１の上側主面の外周部に金属から成る環状部材１１を介して接合されているのが好ましい。これにより、基体１を構成する板部材１ｂ，１ｃ同士の厚み方向の接合ずれにより板部材１ｂ，１ｃ同士の間に段差が生じた場合でも、環状部材１１を基体１の上側主面にロウ付けすることにより、平坦な環状部材１１の上側主面と蓋体３の下端３ｃとを隙間なく接触させることができる。その結果、環状部材１１の上側主面と蓋体３の下端３ｃとをシーム溶接やレーザ溶接等の溶接法によってより強固に接合することができ、光半導体素子収納用パッケージの気密性を向上させることが可能となる。
【００４８】
環状部材１１は、Ｆｅ−Ｎｉ−Ｃｏ合金やＦｅ−Ｎｉ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。そして、ロウ付けや半田付けすることにより基体１の上側主面の外周部に接合される。
【００４９】
環状部材１１の厚さは０．１〜１．５ｍｍであるのがよい。０．１ｍｍ未満であると、環状部材１１が変形し易いために蓋体３の下端３ｃとの接合面を平坦にし難くなり、環状部材１１の上側主面と蓋体３の下端３ｃとを溶接法によってより強固に接合するのが困難になり易い。また、１．５ｍｍを超えると、光半導体素子収納用パッケージを小型化するのが困難になり易い。
【００５０】
また、環状部材１１の外径は、蓋体３の下端３ｃが図１〜６に示すように鍔状になっている場合、この鍔状部の下面の外径と略同じであるのがよい。これにより、蓋体３の鍔状部の下面の中央部だけでなく外側端部も環状部材１１と良好に接合することができる。その結果、環状部材１１の上側主面に蓋体３をシーム溶接やレーザ溶接等の溶接法により接合した場合、環状部材１１と接合している蓋体３の鍔状部の下面と、外気と接しているためにより冷却速度が速い蓋体３の鍔状部の上面との間に収縮差が生じて蓋体３の鍔状部の外周側の端部が上に反り上がろうとするのを有効に抑制することができる。
【００５１】
このように蓋体３の下端３ｃが鍔状になっている場合、環状部材１１の外径は蓋体３の鍔状部の下面の外径の０．９〜１．１倍であるのがよい。０．９倍未満であると、蓋体３と環状部材１１とを溶接法により接合した場合、蓋体３の鍔状部の外周側の端部が上に反り上がるのを抑制する効果が小さくなり易い。また、１．１倍を超えると、半導体素子収納用パッケージを小型化するのが困難になり易い。
【００５２】
また、環状部材１１の外径は、蓋体３の下端３ｃが筒状である場合、蓋体３の下端３ｃの外径よりも大きいことがよい。これにより、蓋体３と環状部材１１をシーム溶接やレーザ溶接等の溶接法により溶接した場合、蓋体３の外側の側面と環状部材１１の上側主面との間に溶接により溶融した蓋体３または環状部材１１の溶融物からなる良好なメニスカスが形成されるため、蓋体３と環状部材１１との接合強度を大きくすることができる。
【００５３】
このように蓋体３の下端３ｃが筒状である場合、環状部材１１の外径は蓋体３の下端３ｃの外径の１．１〜１．５倍であるのがよい。１．１倍未満であると、蓋体３の外側の側面と環状部材１１の上側主面との間に溶接により溶融した蓋体３または環状部材１１の溶融物からなる良好なメニスカスを形成するのが困難となり易く、蓋体３と環状部材１１との接合強度が小さくなり易い。また、１．５倍を超えると、半導体素子収納用パッケージを小型化するのが困難になり易い。
【００５４】
また、環状部材１１は、外周端が基体１の外周端よりも全周にわたって外側に突出しているのがよい。これにより、蓋体３を環状部材１１に接合する際に発生した応力を環状部材１１の基体１から外側にはみ出した部分で吸収することにより、基体１に熱応力が伝わるのを有効に抑制することができる。即ち、環状部材１１の上面に蓋体３をシーム溶接法等により加熱して接合した後の冷却時に、蓋体３の露出した上面は急速に冷却されて収縮しようとするので、蓋体３の上面と環状部材１１との接合部とに温度差が生じて蓋体３および環状部材１１が上側に反ろうとする応力が生じるが、この応力を環状部材１１の基体１からはみ出した部分が適度に変形して吸収することによって基体１に伝え難くすることができる。
【００５５】
環状部材１１は、基体１の外形寸法をＤ１、環状部材１１の外形寸法をＤ２としたとき（図５，図６）、Ｄ１＜Ｄ２≦１．５×Ｄ１とするのがよい。Ｄ２≦Ｄ１であると環状部材１１に蓋体３を接合する際に基体１に応力が加わりやすくなり、入出力端子５にクラック等の破損が生じる場合がある。一方、Ｄ２＞１．５×Ｄ１であると環状部材１１が大きくなり、光半導体素子収納用パッケージを小型化するのが困難になりやすく、また、環状部材１１の変形が大きくなって光半導体素子収納用パッケージが歪み易くなり、光半導体素子２と光ファイバ６との光軸がずれてしまい、光信号を効率よく伝送できなくなる場合がある。
【００５６】
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。
【００５７】
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。
【００５８】
このような光半導体素子収納用パッケージは、基体１の貫通穴１ａに嵌着された入出力端子５に設けられた光半導体素子２の載置部に、光半導体素子２をＳｎ−Ｐｂ半田等の低融点ロウ材で載置固定するとともに、線路導体５ｃと光半導体素子２とをボンディングワイヤ９で電気的に接続し、基体１の上側主面の外周部に蓋体２をシーム溶接等により接合することにより、光半導体装置となる。
【００５９】
そして、光半導体装置の蓋体３の外周の鍔状部には、光ファイバ６が上端面に固定されたＦｅ−Ｎｉ−Ｃｏ合金等の金属から成る略円筒状の固定部材７の下端面が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。
【００６０】
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。
【００６１】
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。
【００６２】
【発明の効果】
本発明の光半導体素子収納用パッケージは、中央部を通る直線状の分割線で二分割された金属板から成る板部材がそれらの分割面同士で接合されて成るとともに中央部の接合線上にこの接合線に長辺が略平行とされた断面形状が略長方形の貫通穴が形成されている基体を具備したことから、この貫通穴に入出力端子を嵌着する際、入出力端子を二分割された２枚の板部材の間の貫通穴の部位に挟み込んでおき、板部材と入出力端子との接合面に圧力を加えた状態でこれらを一体的に接合することができるので、基体の入出力端子部における気密性を向上させることができる。また、従来のように一枚の基体に貫通穴を形成するよりも、２分割された板部材に切り欠き部を形成する方が金属加工の加工精度を向上できるという利点もある。
【００６３】
また、基体の板部材を互いに接合する前に、入出力端子を貫通穴と成る板部材の切り欠き部に嵌め込むことができるため、従来のように入出力端子を貫通穴に挿入する必要がなく、従って、入出力端子と貫通穴の内面との間の引っ掛かりをなくすことができる。その結果、入出力端子と貫通穴の寸法をより近づけることが可能となり、入出力端子と貫通穴との間の隙間を非常に小さくして気密性をより向上させることができる。さらに、板部材の分割面にロウ材のプリフォームを万遍なく設けておき接合することができるので、板部材同士の間や板部材と入出力端子との間の隙間をロウ材で良好に充填することができ、これらの接合強度および気密性を向上させることができる。
【００６４】
また、上記の貫通穴に、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り、貫通穴に嵌着された入出力端子を具備することから、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この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することができることから、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。
【００６５】
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基板に接続することができるため、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。
【００６６】
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。
【００６７】
本発明の光半導体素子収納用パッケージは、蓋体が基体の上側主面の外周部に金属から成る環状部材を介して接合されていることから、基体を構成する板部材同士の厚み方向の接合ずれにより板部材同士の間に段差が生じた場合でも、環状部材を基体の上側主面にロウ付けすることにより、平坦な環状部材の上側主面と蓋体の下端とを隙間なく接触させることができる。その結果、環状部材の上側主面と蓋体の下端とを溶接法によってより強固に接合することができ、光半導体素子収納用パッケージの気密性を向上させることが可能となる。
【００６８】
本発明の光半導体素子収納用パッケージは、環状部材の外周端が基体の外周端よりも全周にわたって外側に突出していることから、蓋体を環状部材に接合する際に発生した応力を環状部材の基体から外側にはみ出した部分で吸収することにより、基体に熱応力が伝わるのを有効に抑制することができる。即ち、環状部材の上面に蓋体をシーム溶接法等により加熱して接合した後の冷却時に、蓋体の露出した上面は急速に冷却されて収縮しようとするので、蓋体の上面と環状部材との接合部とに温度差が生じて蓋体および環状部材が上側に反ろうとする応力が生じるが、この応力を環状部材の基体からはみ出した部分が適度に変形して吸収することによって基体に伝え難くすることができる。
【００６９】
本発明の光半導体装置は、上記の光半導体素子収納用パッケージの載置部に光半導体素子がその受光部または発光部を透光性部材に対向させて載置固定されているとともに線路導体に電気的に接続され、基体の上側主面の外周部に蓋体の下端が接合されていることにより、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周波伝送特性および気密信頼性の優れたものとなる。
【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）の下面図である。
【図３】（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）の下面図である。
【図４】（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）の下面図である。
【図５】（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）の下面図である。
【図６】（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）の下面図である。
【図７】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，１ｃ：板部材
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：入出力端子
５ａ：立壁部
５ｂ：平板部
５ｃ：線路導体
１１：環状部材[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical semiconductor element housing package for housing an optical semiconductor element used in the field of optical communication and the like, and an optical semiconductor device.
[0002]
[Prior art]
FIG. 7 shows an example of an optical semiconductor device in which optical semiconductor elements such as a semiconductor laser (LD) and a photodiode (PD) operating at a high frequency in the field of conventional optical communication and the like are hermetically sealed and housed. FIG. 7 is a sectional view of an optical semiconductor device in which an LD is housed as an optical semiconductor element. In the figure, 21 is a base, 22 is an optical semiconductor element, 23 is a metal lid, 24 is a translucent member, 25 is an external connection pin, and 26 is an optical fiber. The base 21 and the external connection pins 25 basically constitute an optical semiconductor element housing package. Further, the optical semiconductor device is mounted by mounting the optical semiconductor device 22 in the optical semiconductor device housing package and joining the lid 23 to which the translucent member 24 is joined.
[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 a flange shape as shown in FIG. 7, for example, whereby the joint area between the base 21 and the lid 23 is increased, and the inside of the container constituted by the base 21 and the lid 23 is formed. 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 mounted on the optical semiconductor element housing package mainly composed of the base 21 and the external connection pins 25, and the lid 23 to which the translucent member 24 is joined is joined to airtightly. An optical semiconductor device is obtained by sealing (see, for example, Patent Document 1 below).
[0008]
Then, 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. The upper end of the external connection pin 25 is fixed above the translucent member 24, and is electrically connected to an external electric circuit (not shown). Accordingly, light such as laser light is excited in the optical semiconductor element 22 by an electric signal supplied from an external electric circuit, and the light is transmitted through the light transmitting member 24 and the optical fiber 26 in this order, and is transmitted through the optical fiber 26. By transmitting it to the outside, it functions as an optical semiconductor device used for high-speed optical communication and 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
[0009]
[Patent Document 1]
JP 2000-183369 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.
[0011]
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.
[0012]
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.
[0013]
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.
[0014]
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.
[0015]
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.
[0016]
[Means for Solving the Problems]
The package for storing an optical semiconductor element of the present invention is formed by joining a plate member made of a metal plate divided into two by a linear dividing line passing through a central portion at the divided surfaces thereof, and on the joining line at the central portion. A base having a through-hole having a substantially rectangular cross section in which the long sides are substantially parallel to the joining line; a line conductor formed on one main surface from one side to the other side opposite to the base; A flat plate portion made of a dielectric having a mounting portion for an optical semiconductor element provided at one end of the surface, and a dielectric joined to the one main surface of the flat plate portion with a part of the line conductor interposed therebetween. An input / output terminal fitted into the through hole, a through hole is formed at a substantially central portion of the upper end surface, and a lower end is opened, and the input / output terminal is formed in a cylindrical shape. A translucent member is joined around the end face side opening, and The outer periphery of the main surface, characterized in that said one end portion comprising a said light transmissive member made of metal lid that is joined at its lower end to cover so as to face.
[0017]
The package for storing an optical semiconductor element of the present invention is formed by joining a plate member made of a metal plate divided into two by a linear dividing line passing through the central portion at its divided surfaces, and at the same time on the joining line at the central portion. Since the base is provided with a through-hole having a substantially rectangular cross section in which the long sides are substantially parallel to the joining line, the input / output terminal is divided into two when fitting the input / output terminal into the through-hole. Between the two plate members and the input and output terminals can be integrally joined in a state where pressure is applied to the joint surface between the plate members and the input / output terminals. The airtightness at the input / output terminal can be improved. Also, there is an advantage that forming the notch in the plate member divided into two can improve the processing accuracy of metal processing, rather than forming a through hole in one base as in the conventional case.
[0018]
In addition, since the input / output terminals can be fitted into the cutouts of the plate members that form the through holes before the plate members of the base are joined to each other, it is necessary to insert the input / output terminals into the through holes as in the related art. Therefore, it is possible to eliminate the catch between the input / output terminal and the inner surface of the through hole. As a result, the dimensions of the input / output terminal and the through-hole can be made closer, and the gap between the input / output terminal and the through-hole can be made very small, so that the airtightness can be further improved. Furthermore, since the preform of the brazing material can be uniformly provided on the dividing surface of the plate member and joined, the gap between the plate members and the gap between the plate member and the input / output terminal can be satisfactorily filled with the brazing material. They can be filled, and their joining strength and airtightness can be improved.
[0019]
In addition, a flat plate portion made of a dielectric, in which a line conductor is formed in the through hole from one side to the other side opposite to one main surface and a mounting portion of the optical semiconductor element is provided at one end of the one main surface. And an input / output terminal formed of a dielectric wall joined to one main surface of the flat plate portion with a part of the line conductor interposed therebetween and having an input / output terminal fitted in a through hole. A large number of electrode pads, wiring conductors, internal wiring, and the like can be formed at minute intervals. As a result, not only optical semiconductor elements and monitoring PDs but also driver ICs for driving the optical semiconductor elements can be input and output. It can be provided on the surface of the terminal, and signal input / output and driving and control of the optical semiconductor element can be performed by the input / output terminal. Therefore, the driver IC and the like provided in the external electric circuit can be mounted inside the optical semiconductor device and outside the input / output terminals and can be highly integrated, so that the entire device for driving the optical semiconductor element can be downsized. it can.
[0020]
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 the external electric circuit board by the line conductor of the input / output terminal without passing through the external connection pin, it is possible to suppress the transmission loss due to the reflection of the high frequency signal and the like, and the transmission of the high frequency signal. Efficiency can be greatly improved.
[0021]
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.
[0022]
In the package for housing an optical semiconductor element of the present invention, preferably, the lid is joined to an outer peripheral portion of an upper main surface of the base via an annular member made of metal.
[0023]
In the package for housing an optical semiconductor element of the present invention, since the lid is joined to the outer peripheral portion of the upper main surface of the base via an annular member made of metal, the plate members constituting the base are joined in the thickness direction. Even if a step occurs between the plate members due to the displacement, the upper main surface of the flat annular member and the lower end of the lid are brought into contact with no gap by brazing the annular member to the upper main surface of the base. Can be. As a result, the upper main surface of the annular member and the lower end of the lid can be more firmly joined by the welding method, and the airtightness of the package for housing an optical semiconductor element can be improved.
[0024]
In the package for housing an optical semiconductor element according to the present invention, preferably, the annular member has an outer peripheral end projecting outward over the entire periphery from the outer peripheral end of the base.
[0025]
In the optical semiconductor element housing package of the present invention, since the outer peripheral end of the annular member protrudes outward over the entire periphery from the outer peripheral end of the base, the stress generated when the lid is joined to the annular member is reduced. Absorption at the portion protruding outside from the base can effectively suppress transmission of thermal stress to the base. That is, at the time of cooling after heating and joining the lid to the upper surface of the annular member by seam welding or the like, the exposed upper surface of the lid is rapidly cooled and tends to contract, so that the upper surface of the lid and the annular member are When the lid and the annular member warp upward due to a temperature difference between them and the joint between the annular member and the annular member, the portion of the annular member that protrudes from the base is appropriately deformed and absorbed, so that the base is deformed and absorbed. It can be difficult to convey.
[0026]
In the optical semiconductor device of the present invention, the optical semiconductor element is mounted and fixed on the mounting section of the optical semiconductor element housing package with the light receiving section or the light emitting section facing the light transmitting member. It is electrically connected to a line conductor, and a lower end of the lid is joined to an outer peripheral portion of an upper main surface of the base.
[0027]
The optical semiconductor device of the present invention has excellent high-frequency transmission characteristics and airtight reliability using the package for storing an optical semiconductor element of the present invention with the above configuration.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
The package for storing an optical semiconductor element and the optical semiconductor device of the present invention will be described in detail below. 1 to 6 show various examples of the embodiment of the optical semiconductor device of the present invention. FIG. 1A is a cross-sectional view of the optical semiconductor device of the present invention, and FIG. It is a bottom view of an optical semiconductor device.
[0029]
1 to 6, 1 is a base, 2 is an optical semiconductor element, 3 is a metal lid, 4 is a translucent member, 5 is an input / output terminal, 6 is an optical fiber, and 11 is an annular member. The base 1 and the input / output terminals 5 basically constitute an optical semiconductor element housing package. Further, the optical semiconductor device 2 is mounted on the optical semiconductor device housing package, and the lid 3 to which the translucent member 4 is bonded is joined to form an optical semiconductor device.
[0030]
The package for storing an optical semiconductor element according to the present invention is formed by joining plate members 1b and 1c made of a metal plate divided into two by a linear dividing line passing through the central portion at their divided surfaces and joining the central portion. A base 1 having a through-hole 1a having a substantially rectangular cross section whose long side is substantially parallel to the joining line formed on a line, and a line conductor 5c is formed on one main surface from one side to the other side facing the same. And a flat plate portion 5b made of a dielectric having a mounting portion for the optical semiconductor element 2 provided at one end of one main surface, and joined to one main surface of the flat plate portion 5b with a part of the line conductor 5c interposed therebetween. The input / output terminal 5 fitted in the through hole 1a and the through hole 3b formed substantially in the center of the upper end surface 3a and having a lower end 3c opened. And the upper end surface 3a side of the through hole 3b is opened. And a metal cover joined at its lower end 3c to the outer peripheral portion of the upper main surface of the base 1 so as to cover one end of the base member 1 so as to face the translucent member 4. 3 is provided.
[0031]
The base 1 of the present invention has a plate shape such as a substantially disk shape or a substantially rectangular shape, and plate members 1b and 1c formed of a metal plate divided into two by a straight dividing line passing through the center are formed by dividing the divided surfaces thereof. It consists of joined. Such plate members 1b and 1c are manufactured in 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. .
[0032]
In addition, as shown in FIGS. 1 to 6B, a through-hole 1a having a substantially rectangular cross-section having a long side substantially parallel to the joining line is formed on the joining line in the center of the base 1, as shown in FIGS. Have been. 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.
[0033]
The through-hole 1a is formed by forming a cutout at approximately the center of the joining line of one or both of the plate members 1b and 1c, and then joining these plate members 1b and 1c to each other at their divided surfaces with a solder such as Ag solder. By joining through the material, the open portions of the cutout portions of one plate member 1b (1c) are closed by the other, or the open portions of both cutout portions of the plate members 1b and 1c close to each other. It is formed by being performed.
[0034]
By forming the through hole 1a in such a configuration, when the input / output terminal 5 is fitted into the through hole 1a, the input / output terminal 5 is divided into two plate members 1b and 1c. Can be integrally joined in a state where pressure is applied to the joining surfaces of the plate members 1b and 1c and the input / output terminals 5, so that the airtightness at the input / output terminals 5 of the base 1 is maintained. Performance can be improved. Further, forming the cutout portions in the two divided plate members 1b and 1c can improve the processing accuracy of metal processing, rather than forming the through holes 1a in one base body 1 as in the conventional case. is there.
[0035]
Also, before the plate members 1b and 1c of the base 1 are joined to each other, the input / output terminal 5 can be fitted into the cutouts of the plate members 1b and 1c that form the through holes 1a. There is no need to insert the terminal 5 into the through-hole 1a, so that it is possible to eliminate the hook between the input / output terminal 5 and the inner surface of the through-hole 1a. As a result, the dimensions of the input / output terminal 5 and the through hole 1a can be made closer, and the gap between the input / output terminal 5 and the through hole 1a can be made very small to further improve the airtightness. Further, since the preforms of the brazing material can be uniformly provided on the divided surfaces of the plate members 1b and 1c and joined, the gap between the plate members 1b and 1c or between the plate members 1b and 1c and the input / output terminal 5 can be increased. Can be satisfactorily filled with a brazing material, and the joining strength and airtightness thereof can be improved.
[0036]
Preferably, as shown in FIGS. 1 (b), 3 (b), and 5 (b), the base 1 is a straight line passing through the upper surface of the standing wall 5a of the input / output terminal 5, or a flat plate of the input / output terminal 5. It is good to be divided into plate members 1b and 1c by a straight line passing through the lower surface of 5b. Thus, when the input / output terminal 5 and the plate members 1b and 1c, and the plate members 1b and 1c are joined to each other via a brazing material such as Ag brazing, the pressure at the time of joining causes the plate members 1b and 1c and the input / output terminals 5 to join. Can easily flow into the joint between the plate members 1b and 1c, and the joint between the input / output terminal 5 and the plate members 1b and 1c, and between the plate members 1b and 1c. It is possible to form a continuous meniscus of brazing material at the joint. As a result, the joining strength between the input / output terminal 5 and the plate members 1b and 1c and the joining strength between the plate members 1b and 1c can be improved, and the airtightness inside the optical semiconductor device can be further improved. .
[0037]
As shown in FIGS. 1 (a), 3 (a), and 5 (a), the input / output terminal 5 of the present invention has a line conductor 5c formed on one main surface from one side to the other side facing the same. The flat portion 5b provided with the mounting portion of the optical semiconductor element 2 at one end of one main surface and the standing wall portion 5a joined to one main surface of the flat portion 5b with a part of the line conductor 5c interposed therebetween. Be composed. 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, an AlN sintered body, a 3Al 2 O 3 .2SiO 2 sintered body, and the line conductor 5c is made of tungsten. (W) and a metallized layer of molybdenum (Mo).
[0038]
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 tungsten (W) or molybdenum (Mo) is mixed with the ceramic green sheet, using a screen printing method or the like. The metallized layer to be the line conductor 5c is formed in a predetermined pattern by printing and applying the thick film forming technique. 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.
[0039]
The input / output terminal 5 is baked without forming a metallized layer for bonding to the substrate 1 on its surface, and after sintering, the surface of the input / output terminal 5 is slice-cut or polished, and then slice-cut. It is manufactured by printing and applying a metal paste containing W or Mo as the main component on the surface or polished surface by a thick film forming technique such as a screen printing method, and firing this at a temperature of about 1300 ° C. in a reducing atmosphere. You may. Thereby, the surface of the input / output terminal 5 can be flattened, and the bonding with the base 1 can be further improved.
[0040]
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.
[0041]
As shown in FIGS. 2 (a), 4 (a) and 6 (a), the input / output terminal 5 has a metal plate 10 joined to the lower surface of the flat plate portion 5b with a brazing material such as Ag brazing. You may. 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.
[0042]
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.
[0043]
When the metal plate 10 is bonded, the flat plate portion 5b serves as a base for mounting the optical semiconductor element 2 as shown in FIGS. 2 (a), 4 (a) and 6 (a). 8 may be joined to the metal plate 10 in a separated state. 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.
[0044]
Further, the optical semiconductor element 2 mounted on the base 8 and the line conductor 5c are electrically connected via the 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. Adjustment of the impedance is also facilitated.
[0045]
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.
[0046]
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.
[0047]
The lid 3 is preferably joined to the outer peripheral portion of the upper main surface of the base 1 via an annular member 11 made of metal, as shown in FIGS. Thereby, even when a step is generated between the plate members 1b and 1c due to a joining displacement in the thickness direction between the plate members 1b and 1c constituting the base 1, the annular member 11 is brazed to the upper main surface of the base 1. By doing so, the upper main surface of the flat annular member 11 and the lower end 3c of the lid 3 can be brought into contact with no gap. As a result, the upper main surface of the annular member 11 and the lower end 3c of the lid 3 can be more firmly joined by a welding method such as seam welding or laser welding, and the airtightness of the package for housing an optical semiconductor element is improved. It becomes possible.
[0048]
The annular member 11 is made of a metal such as an Fe—Ni—Co alloy or an Fe—Ni alloy, and is formed into a predetermined shape by subjecting the ingot to a conventionally known metal working method such as rolling or punching. Then, it is joined to the outer peripheral portion of the upper main surface of the base 1 by brazing or soldering.
[0049]
The thickness of the annular member 11 is preferably 0.1 to 1.5 mm. When the diameter is less than 0.1 mm, the annular member 11 is easily deformed, so that it is difficult to flatten the joint surface with the lower end 3c of the lid 3, and the upper main surface of the annular member 11 and the lower end 3c of the lid 3 are welded. It tends to be difficult to join more firmly by the method. If it exceeds 1.5 mm, it is likely to be difficult to reduce the size of the package for housing an optical semiconductor element.
[0050]
When the lower end 3c of the lid 3 is formed in a flange shape as shown in FIGS. 1 to 6, the outer diameter of the annular member 11 is preferably substantially the same as the outer diameter of the lower surface of the flange portion. . Thereby, not only the center part of the lower surface of the flange-shaped part of the lid 3 but also the outer end part can be satisfactorily joined to the annular member 11. As a result, when the lid 3 is joined to the upper main surface of the annular member 11 by a welding method such as seam welding or laser welding, the lower surface of the flange-shaped portion of the lid 3 joined to the annular member 11 is connected to the outside air. Due to the contact, there is a difference in contraction between the upper surface of the flange portion of the lid 3 having a high cooling rate, and the outer peripheral end of the flange portion of the lid 3 tends to warp upward. It can be suppressed effectively.
[0051]
When the lower end 3c of the lid 3 has a flange shape as described above, the outer diameter of the annular member 11 is 0.9 to 1.1 times the outer diameter of the lower surface of the flange portion of the lid 3. Good. When it is less than 0.9 times, when the lid 3 and the annular member 11 are joined by a welding method, the effect of suppressing the outer peripheral end of the flange-shaped portion of the lid 3 from rising upward is small. Easy to be. On the other hand, if it exceeds 1.1 times, it becomes easy to reduce the size of the semiconductor device housing package.
[0052]
When the lower end 3c of the lid 3 is cylindrical, the outer diameter of the annular member 11 is preferably larger than the outer diameter of the lower end 3c of the lid 3. Accordingly, when the lid 3 and the annular member 11 are welded by a welding method such as seam welding or laser welding, the lid melted by welding between the outer side surface of the lid 3 and the upper main surface of the annular member 11. Since a good meniscus made of the molten material of the annular member 3 or the annular member 11 is formed, the joining strength between the lid 3 and the annular member 11 can be increased.
[0053]
When the lower end 3c of the lid 3 is cylindrical, the outer diameter of the annular member 11 is preferably 1.1 to 1.5 times the outer diameter of the lower end 3c of the lid 3. When the ratio is less than 1.1 times, a good meniscus is formed between the outer side surface of the lid 3 and the upper main surface of the annular member 11, which is made of a molten material of the lid 3 or the annular member 11 melted by welding. This tends to be difficult, and the joining strength between the lid 3 and the annular member 11 tends to be small. On the other hand, when the ratio exceeds 1.5 times, it becomes difficult to reduce the size of the semiconductor device housing package.
[0054]
Further, it is preferable that the outer peripheral end of the annular member 11 protrudes outward over the entire periphery from the outer peripheral end of the base 1. Thereby, the stress generated when the lid 3 is joined to the annular member 11 is absorbed by the portion of the annular member 11 protruding outside of the base 1, thereby effectively suppressing transmission of thermal stress to the base 1. be able to. That is, at the time of cooling after heating and joining the lid 3 to the upper surface of the annular member 11 by seam welding or the like, the exposed upper surface of the lid 3 is rapidly cooled and contracts. A temperature difference occurs between the upper surface and the joint between the annular member 11 and a stress is generated that causes the lid 3 and the annular member 11 to warp upward. The portion of the annular member 11 that protrudes from the base 1 is appropriately reduced. By being deformed and absorbed, transmission to the base 1 can be made difficult.
[0055]
When the outer dimension of the base member 1 is D1 and the outer dimension of the annular member 11 is D2 (FIGS. 5 and 6), it is preferable that D1 <D2 ≦ 1.5 × D1. When D2 ≦ D1, stress is easily applied to the base 1 when the lid 3 is joined to the annular member 11, and the input / output terminals 5 may be damaged such as cracks. On the other hand, if D2> 1.5 × D1, the size of the annular member 11 becomes large, making it difficult to reduce the size of the optical semiconductor element housing package. The storage package may be easily distorted, the optical axis of the optical semiconductor element 2 and the optical fiber 6 may be shifted, and the optical signal may not be transmitted efficiently.
[0056]
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. The outer peripheral portion of the surface is joined to the lid 3 at the outer peripheral portion of the flat portion in the case of a hemisphere.
[0057]
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.
[0058]
Such an optical semiconductor element housing package includes an optical semiconductor element 2 mounted on an input / output terminal 5 fitted in the through hole 1a of the base 1 and the optical semiconductor element 2 mounted on the mounting portion. The line conductor 5c and the optical semiconductor element 2 are electrically connected to each other by a bonding wire 9, and the lid 2 is attached to the outer peripheral portion of the upper main surface of the base 1 by seam welding or the like. By joining, an optical semiconductor device is obtained.
[0059]
The lower end surface of a substantially cylindrical fixing member 7 made of a metal such as a Fe-Ni-Co alloy to which the optical fiber 6 is fixed on the upper end surface is formed on the outer periphery of the lid 3 of the optical semiconductor device. It is joined by welding such as laser welding. Since the optical fiber 6 is fixed above the translucent member 4 via the fixing member 7, it is possible to exchange optical signals between the optical semiconductor element 2 housed therein and the outside via the optical fiber 6. .
[0060]
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.
[0061]
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.
[0062]
【The invention's effect】
The package for storing an optical semiconductor element of the present invention is formed by joining a plate member made of a metal plate divided into two by a linear dividing line passing through the central portion at its divided surfaces, and at the same time on the joining line at the central portion. Since the base is provided with a through-hole having a substantially rectangular cross section in which the long sides are substantially parallel to the joining line, the input / output terminal is divided into two when fitting the input / output terminal into the through-hole. Between the two plate members and the input and output terminals can be integrally joined in a state where pressure is applied to the joint surface between the plate members and the input / output terminals. The airtightness at the input / output terminal can be improved. Also, there is an advantage that forming the notch in the plate member divided into two can improve the processing accuracy of metal processing, rather than forming a through hole in one base as in the conventional case.
[0063]
In addition, since the input / output terminals can be fitted into the cutouts of the plate members that form the through holes before the plate members of the base are joined to each other, it is necessary to insert the input / output terminals into the through holes as in the related art. Therefore, it is possible to eliminate the catch between the input / output terminal and the inner surface of the through hole. As a result, the dimensions of the input / output terminal and the through-hole can be made closer, and the gap between the input / output terminal and the through-hole can be made very small, so that the airtightness can be further improved. Furthermore, since the preform of the brazing material can be uniformly provided on the dividing surface of the plate member and joined, the gap between the plate members and the gap between the plate member and the input / output terminal can be satisfactorily filled with the brazing material. They can be filled, and their joining strength and airtightness can be improved.
[0064]
In addition, a flat plate portion made of a dielectric, in which a line conductor is formed in the through hole from one side to the other side opposite to one main surface and a mounting portion of the optical semiconductor element is provided at one end of the one main surface. And an input / output terminal formed of a dielectric wall joined to one main surface of the flat plate portion with a part of the line conductor interposed therebetween and having an input / output terminal fitted in a through hole. A large number of electrode pads, wiring conductors, internal wiring, and the like can be formed at minute intervals. As a result, not only optical semiconductor elements and monitoring PDs but also driver ICs for driving the optical semiconductor elements can be input and output. It can be provided on the surface of the terminal, and signal input / output and driving and control of the optical semiconductor element can be performed by the input / output terminal. Therefore, the driver IC and the like provided in the external electric circuit can be mounted inside the optical semiconductor device and outside the input / output terminals and can be highly integrated, so that the entire device for driving the optical semiconductor element can be downsized. it can.
[0065]
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 the external electric circuit board by the line conductor of the input / output terminal without passing through the external connection pin, it is possible to suppress the transmission loss due to the reflection of the high frequency signal and the like, and the transmission of the high frequency signal. Efficiency can be greatly improved.
[0066]
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.
[0067]
In the package for housing an optical semiconductor element of the present invention, since the lid is joined to the outer peripheral portion of the upper main surface of the base via an annular member made of metal, the plate members constituting the base are joined in the thickness direction. Even when a step is generated between the plate members due to the displacement, the upper main surface of the flat annular member and the lower end of the lid are brought into contact with no gap by brazing the annular member to the upper main surface of the base. Can be. As a result, the upper main surface of the annular member and the lower end of the lid can be more firmly joined by the welding method, and the airtightness of the package for housing an optical semiconductor element can be improved.
[0068]
In the optical semiconductor element housing package of the present invention, since the outer peripheral end of the annular member protrudes outward over the entire periphery from the outer peripheral end of the base, the stress generated when the lid is joined to the annular member is reduced. Absorption at the portion protruding outside from the base can effectively suppress transmission of thermal stress to the base. That is, at the time of cooling after heating and joining the lid to the upper surface of the annular member by seam welding or the like, the exposed upper surface of the lid is rapidly cooled and tends to contract, so that the upper surface of the lid and the annular member are When the lid and the annular member warp upward due to a temperature difference between them and the joint between the annular member and the annular member, the portion of the annular member that protrudes from the base is appropriately deformed and absorbed, so that the base is deformed and absorbed. It can be difficult to convey.
[0069]
In the optical semiconductor device of the present invention, the optical semiconductor element is mounted and fixed on the mounting part of the optical semiconductor element housing package with the light receiving part or the light emitting part facing the light transmitting member and the line semiconductor. It is electrically connected, and the lower end of the lid is joined to the outer peripheral portion of the upper main surface of the base, so that the high-frequency transmission characteristics and airtight reliability using the optical semiconductor element housing package of the present invention are excellent. It will be.
[Brief description of the drawings]
1A is a cross-sectional view illustrating an example of an embodiment of an optical semiconductor device of the present invention, and FIG. 1B is a bottom view of FIG.
2A is a cross-sectional view showing another example of the embodiment of the optical semiconductor device of the present invention, and FIG. 2B is a bottom view of FIG.
3A is a cross-sectional view showing another example of the embodiment of the optical semiconductor device of the present invention, and FIG. 3B is a bottom view of FIG.
4A is a cross-sectional view showing another example of the embodiment of the optical semiconductor device of the present invention, and FIG. 4B is a bottom view of FIG.
FIG. 5A is a cross-sectional view showing another example of the embodiment of the optical semiconductor device of the present invention, and FIG. 5B is a bottom view of FIG.
6A is a sectional view showing another example of the embodiment of the optical semiconductor device of the present invention, and FIG. 6B is a bottom view of FIG.
FIG. 7 is a cross-sectional view illustrating an example of a conventional optical semiconductor device.
[Explanation of symbols]
1: base 1a: through holes 1b, 1c: plate member 2: optical semiconductor element 3: lid 3a: upper end surface 3b: through hole 4: translucent member 5: input / output terminal 5a: standing wall portion 5b: flat plate portion 5c : Line conductor 11: annular member