【０００１】
【発明の属する技術分野】
本発明は、光半導体素子を収容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】
従来の光通信分野で用いられるＬＤ（レーザダイオード）やＰＤ（フォトダイオ−ド）等の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（以下、光半導体パッケージともいう）を図２に示す。図２の（ａ）は光半導体パッケージの断面図、（ｂ）は光半導体パッケージのＡ−Ａ’線における断面図である。
【０００３】
図２に示すように、従来の光半導体パッケージは、一般に鉄（Ｆｅ）−ニッケル（Ｎｉ）−コバルト（Ｃｏ）合金や鉄（Ｆｅ）−ニッケル（Ｎｉ）合金等の金属から成る略円板状の基体１０２を有する。基体１０２には、両主面間を貫通する直径０．５〜２ｍｍ程度の円形の貫通孔１０２ａが複数形成されており、その貫通孔１０２ａに鉄（Ｆｅ）−ニッケル（Ｎｉ）−コバルト（Ｃｏ）合金や鉄（Ｆｅ）−ニッケル（Ｎｉ）合金等の金属から成る端子１０９が挿入され、貫通孔１０２ａと端子１０９との接合は鉛を主成分とする絶縁ガラス１０５を介して行なわれ、絶縁ガラス１０５によって基体１０２と端子１０９とが電気的に絶縁される。
【０００４】
また基体１０２は、光半導体パッケージ１０１内部側の一方主面に、銅（Ｃｕ）−タングステン（Ｗ）から成る略立方体の金属ブロック１０４が設けられており、金属ブロック１０４には光半導体素子１０３を載置し実装する載置部１０４ａが設けられている。金属ブロック１０４は、基体１０２に７００〜９００℃の融点を有する銀（Ａｇ）−銅（Ｃｕ）等のロウ材によりロウ付けされて固定される。
【０００５】
また、基体１０２の金属ブロック１０４が接合される一方主面には、外周端から幅１ｍｍ以内の外周部に、光半導体素子１０３の保護を目的として、Ｆｅ−Ｎｉ−Ｃｏ合金等から成る蓋体１０６がＹＡＧレーザ溶接等により固定される。
【０００６】
光半導体素子１０３は、金属ブロック１０４に２００〜４００℃の融点を有する金（Ａｕ）−錫（Ｓｎ）等の低融点ロウ材によりロウ付け固定され、光半導体素子１０３の電極がボンディングワイヤ１０９ａを介して端子１０９に電気的に接続される。
【０００７】
そして、基体１０２の一方主面に蓋体１０６をＹＡＧレーザ溶接、シーム溶接またはロウ付け等によって接合し、基体１０２と蓋体１０６とからなる容器内部に光半導体素子１０３を気密に収容し得る光半導体パッケージ１０１となる。また、光半導体素子１０３と対向する部位に光ファイバ１０７ａが固定される蓋部材１０７を接合することにより、製品としての光半導体装置となる。
【０００８】
この光半導体装置は、外部電気回路（図示せず）から供給される駆動信号によって光半導体素子１０３を光励起させ、励起した光を戻り光防止用の光アイソレータ１０７ｂを介して光ファイバ１０７ａに授受させるとともに光ファイバ１０７ａ内を伝達させることによって、大容量の光通信等に使用される。その適応範囲は４０ｋｍ以下の伝送距離かつ２．５Ｇｂｐｓ（Ｇｉｇａ ｂｉｔ ｐｅｒ ｓｅｃｏｎｄ）以下の伝送容量の範囲で多用されている。
【０００９】
なお、図２において、１１０はプリント配線基板１１１の主面に設けられた放熱板であり、１１１はインピーダンス整合用の線路導体や光半導体素子１０３を制御する制御回路等の電気回路が形成されたプリント配線基板である。
【００１０】
近年、４０ｋｍ以下の伝送距離での高速通信に対する需要が急激に増加しており、高速大容量伝送に関する研究開発が進められている。とりわけ、光通信装置において光信号を発信する光半導体装置等の光発信装置が注目されており、光信号の高速化が伝送容量を向上させるための課題となっている。従来の光半導体装置に用いられていた高周波信号は２．４ＧＨｚ程度であったが、より大容量を伝送できる光半導体装置では１０ＧＨｚの高周波信号が要求されてきている。
【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パッケージ１０１では、１０ＧＨｚ程度の高周波信号で駆動される光半導体素子１０３を搭載した光半導体装置を構成しようとすると、光半導体素子１０３と端子１０９との特性インピーダンスのばらつきが大きいため、光半導体素子１０３が正常に作動し難く、特に１０ＧＨｚ以上の高周波信号の損失を小さくして円滑に通すことが困難であるという問題点があった。
【００１２】
これは、光半導体素子１０３と端子１０９との接続部における特性インピーダンスのばらつきを効果的に抑えることが可能な材料および構造としても、端子１０９が絶縁ガラス１０５に覆われない部位で特性インピーダンスが変動してしまう。即ち、端子１０９と基体１０２との接続部においては、端子１０９の周囲は比誘電率３〜４の絶縁ガラス１０５で覆われているのに対し、端子１０９が絶縁ガラス１０５に覆われていない部位では周囲は比誘電率１の大気であるため、特性インピーダンスが変動し端子１０９全体としてばらつくこととなる。そのため、１０ＧＨｚ以上の高周波信号の損失を小さくして円滑に通すことが困難であり、その結果光半導体素子１０３が正常に作動しないという問題点があった。
【００１３】
また、上記従来の光半導体パッケージ１０１においては、プリント配線基板１１１の電気回路と基体１０２との間の端子１０９の部位（端子１０９の外側の部位）で、高周波信号による反射波および外部からの干渉波が入出力信号と干渉し、入出力信号の損失が発生していた。また、光半導体素子１０３が収納される、基体１０２と蓋体１０６とからなる容器内部において、光半導体素子１０３から出力される高周波信号に起因する共振が発生していた。この共振の影響により、光半導体素子１０３の駆動周波数帯域に局部的に１ｄＢ程度の損失が発生し、光半導体素子１０３が正常に作動し難くなる。特に１０〜４５ＧＨｚの高周波信号の損失を小さくして円滑に通すことが困難であるという問題点があった。
【００１４】
上記の端子１０９の外側の部位における反射および外部からの干渉波による損失は、その部位を流れる高周波信号と基体１０２等の金属部分の反射波とが干渉し合うことで発生する。また、光半導体素子１０３が収納される、基体１０２と蓋体１０６とからなる容器内部においても、光半導体素子１０３から出力される高周波信号に起因する電磁波が、蓋体１０６や基体１０２で跳ね返って共振が発生する。そのため、１０ＧＨｚ以上、特に１０〜４５ＧＨｚの高周波帯域において、端子１０９から光半導体素子１０３に高周波信号を損失を小さくして円滑に通すことが困難であるという問題点があった。
【００１５】
従って、本発明は上記従来の問題点に鑑みて完成されたものであり、その目的は、光半導体素子に接続される端子の特性インピーダンスのばらつきを効果的に抑えるとともに高周波信号の共振を抑制することにより、端子において１０〜４５ＧＨｚの高周波信号を損失を小さくして通すことができ、光半導体素子を正常に作動させることができるようにすることである。その結果、１０Ｇｂｐｓ以上の高速伝送において、共振の影響による高周波信号の損失を防ぐことができる光半導体素子パッケージおよび光半導体装置を提供することである。
【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、中央部に一方主面から他方主面にかけて貫通孔が形成された平板状の基体と、主面に一辺から対向する他辺にかけて配線導体が形成され、前記一辺側に光半導体素子が搭載される絶縁体から成る平板部および該平板部の前記主面に前記配線導体の一部を間に挟んで接合された絶縁体から成る立壁部から成り、前記貫通孔に前記一辺側を前記一方主面側として嵌着された端子部材と、前記基体の前記一方主面側に前記端子部材を覆うように取着されるとともに、前記光半導体素子と対向する部位に光ファイバが固定される蓋部材と、前記基体の前記他方主面に前記端子部材を取り囲んで取着された放熱板と、該放熱版の外側の前記端子部材の周囲に位置するとともに前記平板部の前記主面に略平行になるようにして前記放熱板の露出した主面に一端面が接合された対向する一対の金属板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、主面に一辺から対向する他辺にかけて配線導体が形成され、一辺側に光半導体素子が搭載される絶縁体から成る平板部および平板部の主面に配線導体の一部を間に挟んで接合された絶縁体から成る立壁部から成る端子部材を用いたことにより、光半導体素子と端子との間の特性インピーダンスのばらつきを効果的に抑えることができる。これは、セラミックス等の絶縁体から成る平板部に形成する配線導体の主成分として、Ｗ，Ｍｏ（モリブデン）−Ｍｎ（マンガン）等の金属を自由に選定することができ、またスクリーン印刷法により配線導体の幅、長さ、厚みを自由に調整できることから、配線導体の周囲の誘電率が変化しても、配線導体を周囲の誘電率に合わせてインピーダンスを整合できることによる。
【００１８】
従って、インピーダンスの不整合が生じると予測される場合、配線導体でその不整合を相殺することもできる。例えば、絶縁体の誘電体率の変動によりインピーダンスが高くなると予測できる場合、配線導体の幅、長さ、厚みを調整してそのインピーダンスを低くし、信号線路全体のインピーダンスを整えることができる。その結果、１０ＧＨｚ以上の高周波信号の挿入損失や反射損失を抑制でき、１０ＧＨｚ以上の高周波信号の伝送損失を小さくして通すことが可能となる。具体的には、１０ＧＨｚ程度での特性インピーダンスのばらつきによる損失を３ｄＢ以下に抑制でき、また光半導体装置の性能を示す、デジタル信号等である矩形波の高周波信号の立ちあがり時間も３５ｐｓｅｃ（ピコ秒）以下を達成することができる。
【００１９】
また、放熱板の外側の端子部材の周囲に位置するとともに平板部の主面に略平行になるようにして放熱板の露出した主面に一端面が接合された対向する一対の金属板を有することから、端子の外側の部位を流れる高周波信号の反射波および外部からの干渉波による損失を効果的に抑制することができる。即ち、外部の端子および配線導体を伝送してきた高周波信号が立壁部等での反射波と干渉して放射波が発生しても、その放射波は一対の金属板によって１０ＧＨｚ以上の高周波領域で共振現象が起こらないようにして閉じ込められ、その結果、反射波および外部からの干渉波による損失を小さくすることができる。
【００２０】
また本発明の光半導体素子収納用パッケージは、中央部に一方主面から他方主面にかけて貫通孔が形成された平板状の基体と、主面に一辺から対向する他辺にかけて配線導体が形成され、前記一辺側に光半導体素子が搭載される絶縁体から成る平板部および該平板部の前記主面に前記配線導体の一部を間に挟んで接合された絶縁体から成る立壁部から成り、前記貫通孔に前記一辺側を前記一方主面側として嵌着された端子部材と、前記基体の前記一方主面側に前記端子部材を覆うように取着されるとともに、前記光半導体素子と対向する部位に光ファイバが固定される蓋部材と、前記基体の前記他方主面に前記端子部材を取り囲んで取着された放熱板と、前記基体の内側の前記端子部材の周囲に位置するとともに前記平板部の前記主面に略平行になるようにして前記基体の前記一方主面に一端面が接合された対向する一対の金属板とを具備することを特徴とする。
【００２１】
本発明の光半導体素子収納用パッケージは、基体の内側の端子部材の周囲に位置するとともに平板部の主面に略平行になるようにして基体の一方主面に一端面が接合された対向する一対の金属板を有していることから、光半導体素子収納用パッケージを用いた光半導体装置内部で高周波信号に起因した電磁波の共振が発生するのを防ぐことができる。即ち、光半導体素子が収納される、基体と蓋体とからなる容器内部における高周波信号の放射波（電磁波）が蓋体や基体で跳ね返って電磁波の共振が発生するのを防ぐことができる。その結果、１０〜４５ＧＨｚの高周波帯域において局部的な１ｄＢ程度の損失が発生するのを防ぐことができ、１０〜４５ＧＨｚの高周波信号を損失を小さくして良好に伝送させることができる。
【００２２】
本発明の光半導体装置は、上記発明の光半導体素子収納用パッケージの前記端子部材の前記一辺側に光半導体素子を搭載するとともに、前記基体の前記一方主面側に前記光半導体素子と前記光ファイバとを対向させて前記端子部材を覆うように前記蓋部材を取着して成ることを特徴とする。
【００２３】
本発明の光半導体装置は、上記の構成により、１０〜４５ＧＨｚの高周波信号の伝送損失を小さくして使用することができ、安定した高周波信号の入出力を維持できる高性能のものとなる。
【００２４】
【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は本発明の光半導体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し、（ａ）は光半導体装置の断面図、（ｂ）は（ａ）のＡ−Ａ’線における断面図である。図１において、１は光半導体パッケージ、２は基体、２ａは基体２に形成された貫通孔、３は光半導体素子、４は光半導体素子３が搭載される絶縁体から成る平板部、４ａは平板部４の一主面に形成された配線導体、５は絶縁体から成る立壁部である。また、６は光半導体素子３の気密封止用として設けられた蓋体、７は光半導体素子３と対向する位置に光ファイバ７ａが固定された蓋部材、７ａは光ファイバ、８は基体２の他方主面に接合された放熱板、９は高周波信号の入出力用の端子である。また、１０は端子９の外側の端部に接合されたプリント配線基板、１１は端子部材である。また、１２，１２ａは本発明の金属板である。
【００２５】
本発明の光半導体パッケージは、中央部に一方主面から他方主面にかけて貫通孔２ａが形成された平板状の基体２と、主面に一辺から対向する他辺にかけて配線導体４ａが形成され、一辺側に光半導体素子３が搭載される絶縁体から成る平板部４および平板部４の主面に配線導体４ａの一部を間に挟んで接合された絶縁体から成る立壁部５から成り、貫通孔２ａに一辺側を一方主面側として嵌着された端子部材１１と、基体２の一方主面側に端子部材１１を覆うように取着されるとともに、光半導体素子３と対向する部位に光ファイバ７ａが固定される蓋部材７と、基体２の他方主面に端子部材１１を取り囲んで取着された放熱板８と、放熱板８の外側の端子部材１１の周囲に位置するとともに平板部４の主面に略平行になるようにして放熱板８の露出した主面に一端面が接合された対向する一対の金属板１２とを具備している。
【００２６】
また本発明の光半導体パッケージは、中央部に一方主面から他方主面にかけて貫通孔２ａが形成された平板状の基体２と、主面に一辺から対向する他辺にかけて配線導体４ａが形成され、一辺側に光半導体素子３が搭載される絶縁体から成る平板部４および平板部４の主面に配線導体４ａの一部を間に挟んで接合された絶縁体から成る立壁部５から成り、貫通孔２ａに一辺側を一方主面側として嵌着された端子部材１１と、基体２の一方主面側に端子部材１１を覆うように取着されるとともに、光半導体素子３と対向する部位に光ファイバ７ａが固定される蓋部材７と、基体２の他方主面に端子部材１１を取り囲んで取着された放熱板８と、基体２の内側の端子部材１１の周囲に位置するとともに平板部４の主面に略平行になるようにして基体２の一方主面に一端面が接合された対向する一対の金属板１２ａとを具備している。
【００２７】
本発明の光半導体装置は、主面の一辺から対向する他辺にかけて形成された配線導体４ａおよび配線導体４ａが形成されていない一辺側の部位に光半導体素子３が載置される載置部を有する略直方体の絶縁体から成る平板部４と、平板部４の主面に配線導体４ａの一部を間に挟むように接合された略直方体の絶縁体から成る立壁部５とから成る端子部材１１を有している。この端子部材１１を有することにより、半導体素子３と端子９との間の特性インピーダンスの不整合を効果的に抑えることができる。これは、セラミックス等の絶縁体から成る平板部４に形成する配線導体４ａの主成分として、Ｗ，Ｍｏ−Ｍｎ等の金属を自由に選定することができ、またスクリーン印刷法により配線導体４ａの幅、長さ、厚みを自由に変更できることから、配線導体４ａの周囲（平板部４、立壁部５）の誘電率が変化しても、特性インピーダンスの不整合を効果的に抑えることが可能となることによる。従って、本発明の光半導体装置は１０ＧＨｚ以上の高周波信号を低損失で通すことが可能となる。
【００２８】
具体的には、従来１０ＧＨｚでの透過損失が６ｄＢ程度であったのを、本発明では３ｄＢ程度に減少させることができる。これにより、光通信等の用いられる光半導体装置を用いた光モジュールのＥＹＥ（アイ）特性に影響を及ぼさない特性となる。ＥＹＥ特性とは、デジタル信号が円滑に伝送できているかを示す特性であり、パルス発生器で発生させた信号パルスを光モジュールに入力し、光モジュール内で光電変換を行なった後に光信号として光ファイバ７ａから出力されたものが、本来の矩形波が歪んで正弦波等に近くなっており、その光信号を分析することにより得られる特性である。この場合、＋側の矩形波（例えばデジタル信号の「１」に相当する信号）と−側の矩形波（例えばデジタル信号の「０」に相当する信号）とを位相をずらして重ね合わせると、人の目（ｅｙｅ）のように見えることからＥＹＥ特性と呼ばれる。
【００２９】
そして、デジタル信号の１，０の点（ピーク値）以外にオーバーシュート等の認識点があるとエラーとして処理される。高周波信号の共振がある場合エラーモードの発生率が高くなる。デジタル信号の合否判断としては、矩形波の軌跡に囲まれた人の目状の部分がどのくらいオープンになっているかで表す。一般に、人の目状の部分を窓と呼んでおり、窓にかかる点や窓に入りこむ軌跡が発生すれば、即ち窓の形状が所望のものから外れていれば、デジタル信号の１，０とは判定されずにエラーとなる。
【００３０】
本発明の光半導体装置は、放熱板８の外側の端子部材１１の周囲に位置するとともに平板部４の主面に略平行になるようにして放熱板８の露出した主面に一端面が接合された対向する一対の金属板１２を具備する。この構成により、端子９および配線導体４ａを伝送してきた高周波信号が立壁部５等での反射波と干渉して放射波が発生しても、その放射波は一対の金属板によって１０ＧＨｚ以上の高周波領域で共振現象が起こらないように閉じ込められ、その結果、反射波および外部からの干渉波による損失を小さくすることができる。
【００３１】
従って、１０〜４５ＧＨｚの高周波帯域において光半導体装置としての立ち上がり時間を３５ｐｓｅｃ以下とすることができる。
【００３２】
また本発明の光半導体装置は、基体２の内側の端子部材１１の周囲に位置するとともに平板部４の主面に略平行になるようにして基体２の一方主面に一端面が接合された対向する一対の金属板１２ａを具備する。この構成により、光半導体素子が収納される、基体２と蓋体６とからなる容器内部における高周波信号の放射波（電磁波）が蓋体６や基体２で跳ね返って電磁波の共振が発生するのを防ぐことができる。その結果、１０〜４５ＧＨｚの高周波帯域で局部的な１ｄＢ程度の損失が発生するのを防ぐことができ、１０〜４５ＧＨｚの高周波信号を損失を小さくして良好に伝送させることができるとともに、１０〜４５ＧＨｚの高周波帯域において光半導体装置としての立ち上がり時間を３５ｐｓｅｃ以下とすることができる。
【００３３】
本発明の金属板１２，１２ａは、Ｃｕ，Ａｇ，Ａｕ，Ｆｅ，Ｎｉ，Ｔｉ，Ｃｒ，Ｍｏ，Ｗ，Ａｌ等の金属およびこれら金属の合金、例えばＦｅ−Ｎｉ−Ｃｏ合金，Ｆｅ−Ｎｉ合金，真鍮（Ｃｕ−Ｚｎ合金），ステンレススチール，Ｃｕ−Ｗ等の合金から成る。この金属板１２，１２ａは、その金属や合金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方法を施すことによって所定形状に製作される。金属板１２，１２ａの表面には耐食性に優れかつロウ材との濡れ性に優れた厚さ０．５〜９μｍのＮｉ層と厚さ０．５〜５μｍのＡｕ層をメッキ法により順次被着させておくのが良く、金属板１２，１２ａが酸化腐食するのを有効に防止するとともに、各部品を金属板１２，１２ａに良好にロウ付けできる。
【００３４】
金属板１２は、図１に示すように、端子部材１１の主面および端子９の主面を覆うように設置されるのがよい。この場合、配線導体４ａおよび端子９で伝送される高周波信号の損失を有効に抑制できる。また、一つの光半導体装置に金属板１２および金属板１２ａを設けてもよい。この場合、端子９で伝送される高周波信号の反射波および外部からの干渉波による損失を抑制できるとともに光半導体装置内部の高周波信号の共振の発生を抑えることができ、高周波信号の伝送損失をより小さくできる。
【００３５】
また、金属板１２は、端子部材１１に接していることが好ましく、高周波信号の放射損失を有効に抑制するとともに光半導体素子３の熱を外部に伝熱および放散し易くなる。さらに、金属板１２ａは、端子部材１１に接していることが好ましく、この場合、金属板１２ａ間の間隔が小さくなって高周波信号の共振周波数を高周波側へずらすことができ、共振の影響を小さくすることができる。
【００３６】
一つの光半導体装置に金属板１２および金属板１２ａを設ける場合、金属板１２は金属板１２ａよりも厚いことが好ましく、光半導体素子３の熱を薄い金属板１２ａに蓄熱させずに速やかに熱伝導させ、また、厚く体積が大きい金属板１２によって熱を光半導体装置の外部においてある程度蓄熱するとともに放散させ易くすることができる。
【００３７】
基体２は、Ｆｅ−Ｎｉ−Ｃｏ合金等の金属から成る。この基体２は、そ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方法を施すことによって所定形状に製作される。この基体２の中心部には、端子部材１１を嵌着するための略長方形の貫通孔２ａが形成されている。また、基体２の表面には、耐食性に優れかつロウ材との濡れ性に優れた厚さ０．５〜９μｍのＮｉ層と厚さ０．５〜５μｍのＡｕ層をメッキ法により順次被着させておくのが良く、基体２が酸化腐食するのを有効に防止するとともに、各部品を基体２に良好にロウ付けすることができる。
【００３８】
基体２に設けられる端子部材１１は、一主面にメタライズ層等から成る配線導体４ａが形成された略直方体の絶縁体から成る平板部４と、配線導体４ａの一部を間に挟んで平板部４の一主面に接合され、基体２の内外を遮断するように形成された略直方体の絶縁体から成る立壁部５とから成っている。平板部４および立壁部５は、酸化アルミニウム質焼結体（酸化アルミニウムセラミックス）、窒化アルミニウム質焼結体、ガラスセラミックス等の絶縁体から成る。
【００３９】
また、平板部４の一主面には配線導体４ａが形成され、平板部４の一主面の一辺側には光半導体素子３が搭載される。この光半導体素子３はボンディングワイヤで配線導体４ａに電気的に接続され、端子９を介して外部電気回路に電気的に接続される。平板部４に形成された配線導体４ａや接地導体はＷ，Ｍｏ，Ｍｎ等から成り、例えばＷ等の粉末に有機溶剤、溶媒を添加混合して得た金属ペーストを、平板部４となるセラミックグリーンシートにスクリーン印刷法により所定パターンに印刷塗布し、そのセラミックグリーンシートを積層し、焼成することによって形成される。配線導体４ａや接地導体の表面には、酸化防止のためとボンディングワイヤや端子９等を強固に接続するために、厚さ０．５〜９μｍのＮｉ層や厚さ０．５〜５μｍのＡｕ層等の金属層をメッキ法により順次被着させておくと良い。
【００４０】
また、光半導体素子３は、Ｆｅ−Ｎｉ−Ｃｏ合金等から成る基体２の一方主面の外周部にＦｅ−Ｎｉ−Ｃｏ合金等から成る蓋体６をシーム溶接等によって接合することにより気密封止される。
【００４１】
放熱板８は、１５０Ｗ／ｍＫ以上の熱伝導率を有する金属が好ましく、放熱板８の熱伝導率は基体２よりも１００Ｗ／ｍＫ以上高いことがよいが、例えば基体２の熱伝導率を１７Ｗ／ｍＫ（Ｆｅ−Ｎｉ−Ｃｏ合金等）とし、放熱板８の熱伝導率を１８０Ｗ／ｍＫ（Ｃｕ−Ｗ合金等）とする。これは、蓋体６と基体２とを溶接し封止する際などに発生する熱が放熱板８に拡散し、溶接部の温度が低下して円滑な封止が困難になることを防ぐためである。放熱板８の熱伝導率が基体２よりも１００Ｗ／ｍＫ以上高いと、シーム溶接やＹＡＧレーザ溶接等の溶接方法に関係無く良好な溶接封止が可能になる。即ち、蓋体６を溶融させて溶接する際に熱の拡散が発生すれば、蓋体６の溶接されるべき部位が溶け難くなり、円滑な封止ができなくなるが、放熱板８の熱伝導率が基体２よりも１００Ｗ／ｍＫ以上高いとそのような不具合が解消される。
【００４２】
また、基体２の厚みは０．５ｍｍ以上がよい。０．５ｍｍ未満だと、端子部材１１を基体２の貫通孔２ａに嵌着しロウ付け等で接合し蓋体６を基体２に溶接した際に、溶接の条件（温度等）により基体２が曲がったりして変形し易くなり、溶接強度および端子部材１１の接合強度が劣化して、光半導体パッケージの気密封止に不具合を生じ易くなる。
【００４３】
本発明の光半導体パッケージ１は、ＬＤ，ＰＤ等の光半導体素子３およびＬＳＩ等の半導体素子を収納した光通信用のものの場合、基体２に内外を貫通する貫通孔２ａを形成し、貫通孔２ａに、主面に配線導体４ａが形成された略直方体の絶縁体から成る平板部４および配線導体４ａの一部を間に挟んで平板部４の主面に接合され、基体２の内外を遮断する略直方体の絶縁体から成る立壁部５から成る端子部材１１を嵌着接合する。そして、光半導体素子３を平板部４に搭載するとともに配線導体４ａにボンディングワイヤで接続する。その後、基体２の一方主面に蓋体６をシーム溶接等で接合する。しかる後、蓋体６の外周部（鍔状部）に、光ファイバ７ａと戻り光防止用の光アイソレータ７ｂとが樹脂接着剤で接着された蓋部材７を、ＹＡＧレーザ溶接等で接合することによって、製品としての光半導体装置となる。また、この半導体装置は端子９を介してプリント配線基板１０等に電気的に接続される。
【００４４】
かくして、本発明の光半導体パッケージ１は、セラミックス等の絶縁体から成る端子部材１１の誘電率、配線導体４ａの主成分、幅、長さおよび厚さを調整することによって、特性インピーダンスを整合させることができ、高周波信号の透過損失を小さくして高周波信号を円滑に伝送させることができる。また、金属板１２，１２ａを用いることで、１０〜４５ＧＨｚの高周波帯域における伝送損失を抑制でき、高周波信号を安定して円滑に伝送できる。その結果、本発明の光半導体パッケージ１を用いて光半導体装置と成した場合、光半導体素子３に入出力する高周波信号を効率よく伝送させることができる。
【００４５】
【実施例】
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の実施例を以下に説明する。
【００４６】
図１の光半導体装置を以下のように構成した。まず、厚さ１ｍｍ×縦４．５ｍｍ×横３ｍｍの平板部４となるアルミナを主成分とする直方体のセラミックグリーンシート積層体Ａの一主面および側面に、配線導体４ａおよび接地導体となるＷペーストをスクリーン印刷法で印刷塗布し、厚さ１ｍｍ×縦１．５ｍｍ×横３ｍｍの立壁部５となるアルミナを主成分とする直方体のセラミックグリーンシート積層体Ｂをセラミックグリーンシート積層体Ａの一主面に積層し、同時焼成して端子部材１１を作製した。得られた端子部材１１は、長さ４．５ｍｍ、厚さ２ｍｍであり、平板部４および立壁部５の比誘電率が９で、Ｗのメタライズ層から成る配線導体４ａの幅が３ｍｍであった。
【００４７】
また、基体２は、厚さ１ｍｍのＦｅ−Ｎｉ−Ｃｏ合金のインゴットを加工して、厚さ１ｍｍ、直径４．６ｍｍの円板状とした。基体２の中央部には、打ち抜き加工により端子部材１１を嵌着するための四角形の貫通孔２ａを形成した。基体２の表面には、厚さ２μｍのＮｉ層と厚さ２μｍのＡｕ層をメッキ法により順次被着した。放熱板８は、Ｃｕ−Ｗ合金から成る、厚さ１ｍｍ、直径４．６ｍｍの円板状のものとし、その中央部に端子部材１１を挿通させるための貫通孔が形成されており、基体２の他方主面にＡｇロウで接合した。
【００４８】
そして、基体２の貫通孔２ａおよび放熱板８の貫通孔に端子部材１１を嵌め込み、Ａｇロウで接合することにより嵌着接合した。
【００４９】
また、金属板１２は厚さ１ｍｍのＦｅ−Ｎｉ−Ｃｏ合金のインゴットを加工して、厚さ１ｍｍ、長さ（高周波信号の伝送方向に平行な方向の長さ）４ｍｍ、幅（高周波信号の伝送方向に直交する方向の長さ）４ｍｍの板状とした。同様にして、厚さ１ｍｍ、長さ６ｍｍ、幅６ｍｍの金属板１２ａを作製した。
【００５０】
その後、放熱板８の露出した主面に対向する一対の金属板１２を、端子部材１１の平板部４に略平行になるとともに端子部材１１に接するようにして、Ａｇロウを介して接合した。
【００５１】
次に、平板部４の一方主面の配線導体４ａの一辺側の端部にＬＤである光半導体素子３を半田付けして搭載し、光半導体素子３と配線導体４ａとをボンディングワイヤで電気的に接続した。また、基体２の一方主面に対向する一対の金属板１２ａを、端子部材１１の平板部４に略平行になるとともに端子部材１１に接するようにして、Ａｇロウを介して接合した。
【００５２】
そして、Ｆｅ−Ｎｉ−Ｃｏ合金から成る蓋体６を基体２の一方主面の外周部にシーム溶接により接合し気密封止した。しかる後、蓋体６の外周端部に、光ファイバ７ａと光アイソレータ７ｂとを樹脂接着剤で接着した蓋部材７をＹＡＧレーザ溶接により接合し、光半導体装置を作製した。
【００５３】
この光半導体装置について、金属板１２ａの間隔によって発生する共振周波数をシミュレーションによって算出した結果を表１および図３のグラフに示す。
【００５４】
なお、共振周波数の算出は、ｆｃ＝Ｃｏ／２｛（１／ａ）２＋（１／ｂ）２＋（１／ｃ）２｝１／２（ｆｃ：共振周波数、ａ：金属板１２ａの幅、ｂ：金属板１２ａ間の間隔、ｃ：金属板１２ａの長さ、Ｃｏ：２．９９８×１０８ｍ／ｓ）を用いて、ａ，ｃに３ｍｍ，４ｍｍ，５ｍｍ，６ｍｍをそれぞれ代入して行なった。これにより、１０〜４５ＧＨｚの間で共振点が発生しない金属板１２ａ間の間隔ｂを導き出した。また、図３において、×印はａ，ｃが４ｍｍのデータ、△印はａ，ｃが５ｍｍのデータ、□印はａ，ｃが６ｍｍのデータをそれぞれ示す。
【００５５】
【表１】
【００５６】
表１より、ａ，ｃが５ｍｍのサンプルでは、ｂが９ｍｍ以下で共振周波数が４５ＧＨｚを超え、１０〜４５ＧＨｚで共振点が発生しないことが判った。ａ，ｃが６ｍｍのサンプルでは、ｂが５ｍｍ以下で共振周波数が４５ＧＨｚを超え、１０〜４５ＧＨｚで共振点が発生しないことが判った。
【００５７】
また、ａ，ｃが３ｍｍのサンプルとａ，ｃが４ｍｍのサンプルとでは、ｂが１２ｍｍ以下であれば、共振周波数が４５ＧＨｚを超え、１０〜４５ＧＨｚで共振点が発生しないことが判った。従って、ａ，ｃを４ｍｍ以下とすることが好ましい。
【００５８】
また、金属板１２ａがないと、光半導体素子３を覆う蓋体６の内寸法が４ｍｍ以上となるために、光半導体装置において共振周波数３６．４ＧＨｚの共振で発生した。
【００５９】
なお、本発明は上記実施の形態および実施例に限定されず、本発明の要旨を逸脱しない範囲内で種々の変更を行うことは何等差し支えない。
【００６０】
【発明の効果】
本発明の光半導体素子収納用パッケージは、中央部に一方主面から他方主面にかけて貫通孔が形成された平板状の基体と、主面に一辺から対向する他辺にかけて配線導体が形成され、一辺側に光半導体素子が搭載される絶縁体から成る平板部および平板部の主面に配線導体の一部を間に挟んで接合された絶縁体から成る立壁部から成り、貫通孔に一辺側を一方主面側として嵌着された端子部材と、基体の一方主面側に端子部材を覆うように取着されるとともに、光半導体素子と対向する部位に光ファイバが固定される蓋部材と、基体の他方主面に端子部材を取り囲んで取着された放熱板と、放熱版の外側の端子部材の周囲に位置するとともに平板部の主面に略平行になるようにして放熱板の露出した主面に一端面が接合された対向する一対の金属板とを具備することにより、光半導体素子と端子との間の特性インピーダンスのばらつきを効果的に抑えることができる。これは、セラミックス等の絶縁体から成る平板部に形成する配線導体の主成分として、Ｗ，Ｍｏ−Ｍｎ等の金属を自由に選定することができ、またスクリーン印刷法により配線導体の幅、長さ、厚みを自由に調整できることから、配線導体の周囲の誘電率が変化しても、配線導体を周囲の誘電率に合わせてインピーダンスを整合できることによる。
【００６１】
従って、インピーダンスの不整合が生じると予測される場合、配線導体でその不整合を相殺することもできる。例えば、絶縁体の誘電体率の変動によりインピーダンスが高くなると予測できる場合、配線導体の幅、長さ、厚みを調整してそのインピーダンスを低くし、信号線路全体のインピーダンスを調整できる。その結果、１０ＧＨｚ以上の高周波信号の挿入損失や反射損失を抑制でき、１０ＧＨｚ以上の高周波信号の伝送損失を小さくすることができる。具体的には、１０ＧＨｚ程度での特性インピーダンスのばらつきによる損失を３ｄＢ以下に抑制でき、また光半導体装置の性能を示す、デジタル信号等である矩形波の高周波信号の立ちあがり時間も３５ｐｓｅｃ以下を達成することができる。
【００６２】
また、対向する一対の金属板を有することから、端子の外側の部位を流れる高周波信号の反射波および外部からの干渉波による損失を効果的に抑制することができる。即ち、外部の端子および配線導体を伝送してきた高周波信号が立壁部等での反射波と干渉して放射波が発生しても、その放射波は一対の金属板によって１０ＧＨｚ以上の高周波領域で共振現象が起こらないように閉じ込められて、その結果、反射波および外部からの干渉波による損失を小さくすることができる。
【００６３】
また本発明の光半導体素子収納用パッケージは、中央部に一方主面から他方主面にかけて貫通孔が形成された平板状の基体と、主面に一辺から対向する他辺にかけて配線導体が形成され、一辺側に光半導体素子が搭載される絶縁体から成る平板部および平板部の主面に配線導体の一部を間に挟んで接合された絶縁体から成る立壁部から成り、貫通孔に一辺側を一方主面側として嵌着された端子部材と、基体の一方主面側に端子部材を覆うように取着されるとともに、光半導体素子と対向する部位に光ファイバが固定される蓋部材と、基体の他方主面に端子部材を取り囲んで取着された放熱板と、基体の内側の端子部材の周囲に位置するとともに平板部の主面に略平行になるようにして基体の一方主面に一端面が接合された対向する一対の金属板とを具備することにより、光半導体素子収納用パッケージを用いた光半導体装置内部で高周波信号に起因した電磁波の共振が発生するのを防ぐことができる。即ち、光半導体素子が収納される、基体と蓋体とからなる容器内部における高周波信号の放射波（電磁波）が蓋体や基体で跳ね返って電磁波の共振が発生するのを防ぐことができる。その結果、１０〜４５ＧＨｚの高周波帯域において局部的な１ｄＢ程度の損失が発生するのを防ぐことができ、１０〜４５ＧＨｚの高周波信号を損失を小さくして良好に伝送させることができる。
【００６４】
本発明の光半導体装置は、上記発明の光半導体素子収納用パッケージの端子部材の一辺側に光半導体素子を搭載するとともに、基体の一方主面側に光半導体素子と光ファイバとを対向させて端子部材を覆うように蓋部材を取着して成ることにより、１０〜４５ＧＨｚの高周波信号の伝送損失を小さくして使用することができ、安定した高周波信号の入出力を維持できる高性能のものとなる。
【図面の簡単な説明】
【図１】本発明の光半導体装置について実施の形態の一例を示し、（ａ）は光半導体装置の断面図、（ｂ）は（ａ）のＡ−Ａ’線における断面図である。
【図２】従来の光半導体装置の一例を示し、（ａ）は光半導体装置の断面図、（ｂ）は（ａ）のＡ−Ａ’線における断面図である。
【図３】本発明の光半導体装置について金属板の間隔ｂと共振周波数との関係を示すグラフである。
【符号の説明】
１：光半導体素子収納用パッケージ
２：基体
２ａ：貫通孔
３：光半導体素子
４：平板部
４ａ：配線導体
５：立壁部
６：蓋体
７：蓋部材
８：放熱板
１１：端子部材
１２，１２ａ：金属板[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical semiconductor element housing package for housing an optical semiconductor element and an optical semiconductor device.
[0002]
[Prior art]
FIG. 2 shows an optical semiconductor element housing package (hereinafter also referred to as an optical semiconductor package) for housing an optical semiconductor element such as an LD (laser diode) or a PD (photodiode) used in the conventional optical communication field. Show. 2A is a cross-sectional view of the optical semiconductor package, and FIG. 2B is a cross-sectional view of the optical semiconductor package taken along line AA ′.
[0003]
As shown in FIG. 2, a conventional optical semiconductor package generally has a substantially disc shape made of a metal such as an iron (Fe) -nickel (Ni) -cobalt (Co) alloy or an iron (Fe) -nickel (Ni) alloy. Of the base 102. A plurality of circular through-holes 102a having a diameter of about 0.5 to 2 mm penetrating between the main surfaces are formed in the base 102, and iron (Fe) -nickel (Ni) -cobalt (Co) is formed in the through-holes 102a. ) A terminal 109 made of a metal such as an alloy or an iron (Fe) -nickel (Ni) alloy is inserted, and the connection between the through hole 102a and the terminal 109 is performed through an insulating glass 105 containing lead as a main component. The base 105 and the terminal 109 are electrically insulated by the glass 105.
[0004]
The base 102 is provided with a substantially cubic metal block 104 made of copper (Cu) -tungsten (W) on one main surface inside the optical semiconductor package 101, and the optical semiconductor element 103 is mounted on the metal block 104. A mounting portion 104a for mounting and mounting is provided. The metal block 104 is fixed to the base 102 by brazing with a brazing material such as silver (Ag) -copper (Cu) having a melting point of 700 to 900 ° C.
[0005]
On one main surface of the base 102 to which the metal block 104 is joined, a lid made of an Fe—Ni—Co alloy or the like is provided on the outer peripheral portion within 1 mm from the outer peripheral edge for the purpose of protecting the optical semiconductor element 103. 106 is fixed by YAG laser welding or the like.
[0006]
The optical semiconductor element 103 is fixed to the metal block 104 by brazing with a low melting point brazing material such as gold (Au) -tin (Sn) having a melting point of 200 to 400 ° C., and the electrode of the optical semiconductor element 103 is connected to the bonding wire 109 a. The terminal 109 is electrically connected to the terminal 109.
[0007]
Then, a lid 106 is joined to one main surface of the base 102 by YAG laser welding, seam welding, brazing, or the like, and light capable of hermetically housing the optical semiconductor element 103 inside a container including the base 102 and the lid 106. The semiconductor package 101 is obtained. In addition, by joining the cover member 107 to which the optical fiber 107a is fixed at a portion facing the optical semiconductor element 103, an optical semiconductor device as a product is obtained.
[0008]
In this optical semiconductor device, the optical semiconductor element 103 is optically excited by a drive signal supplied from an external electric circuit (not shown), and the excited light is transmitted to and received from the optical fiber 107a via an optical isolator 107b for preventing return light. In addition, by transmitting the light through the optical fiber 107a, it is used for large-capacity optical communication and the like. The adaptation range is frequently used in a range of a transmission distance of 40 km or less and a transmission capacity of 2.5 Gbps (Giga bit per second) or less.
[0009]
In FIG. 2, reference numeral 110 denotes a heat sink provided on the main surface of the printed wiring board 111, and reference numeral 111 denotes an electric circuit such as a line conductor for impedance matching and a control circuit for controlling the optical semiconductor element 103. It is a printed wiring board.
[0010]
In recent years, demand for high-speed communication over a transmission distance of 40 km or less has been rapidly increasing, and research and development on high-speed and large-capacity transmission have been promoted. In particular, optical transmission devices such as an optical semiconductor device that transmits an optical signal in an optical communication device have attracted attention, and increasing the speed of the optical signal has been a problem for improving the transmission capacity. A high-frequency signal used in a conventional optical semiconductor device is about 2.4 GHz, but an optical semiconductor device capable of transmitting a larger capacity requires a high-frequency signal of 10 GHz.
[0011]
[Problems to be solved by the invention]
However, in the above-described conventional optical semiconductor package 101, when an optical semiconductor device including the optical semiconductor element 103 driven by a high-frequency signal of about 10 GHz is to be mounted, the characteristic impedance between the optical semiconductor element 103 and the terminal 109 varies. Due to the large size, the optical semiconductor element 103 has a problem that it is difficult to operate normally, and it is particularly difficult to reduce the loss of a high frequency signal of 10 GHz or more and to make it pass smoothly.
[0012]
This is because even if the material and the structure can effectively suppress the variation of the characteristic impedance at the connection portion between the optical semiconductor element 103 and the terminal 109, the characteristic impedance fluctuates at a portion where the terminal 109 is not covered with the insulating glass 105. Resulting in. That is, in the connection portion between the terminal 109 and the base 102, the periphery of the terminal 109 is covered with the insulating glass 105 having a relative dielectric constant of 3 to 4, whereas the terminal 109 is not covered with the insulating glass 105. In this case, since the surroundings are air having a relative dielectric constant of 1, the characteristic impedance fluctuates and the terminal 109 varies as a whole. Therefore, it is difficult to reduce the loss of the high-frequency signal of 10 GHz or more and make it pass smoothly, and as a result, there is a problem that the optical semiconductor element 103 does not operate normally.
[0013]
Further, in the above-described conventional optical semiconductor package 101, a reflected wave due to a high-frequency signal and external interference occur at a portion of the terminal 109 (a portion outside the terminal 109) between the electric circuit of the printed wiring board 111 and the base 102. The waves interfered with the input and output signals, causing loss of the input and output signals. In addition, resonance caused by a high-frequency signal output from the optical semiconductor element 103 has occurred inside the container including the base 102 and the lid 106 in which the optical semiconductor element 103 is stored. Due to the influence of this resonance, a loss of about 1 dB is locally generated in the driving frequency band of the optical semiconductor element 103, and it becomes difficult for the optical semiconductor element 103 to operate normally. In particular, there is a problem in that it is difficult to reduce the loss of a high-frequency signal of 10 to 45 GHz and smoothly pass the signal.
[0014]
The loss due to the reflection at the portion outside the terminal 109 and the interference wave from the outside is caused by the interference between the high-frequency signal flowing through the portion and the reflected wave from the metal portion such as the base 102. Also, inside the container including the base 102 and the lid 106 in which the optical semiconductor element 103 is accommodated, the electromagnetic wave caused by the high-frequency signal output from the optical semiconductor element 103 bounces off the lid 106 and the base 102. Resonance occurs. For this reason, in a high frequency band of 10 GHz or more, particularly 10 to 45 GHz, there is a problem that it is difficult to reduce the loss of the high frequency signal from the terminal 109 to the optical semiconductor element 103 and smoothly pass the signal.
[0015]
Therefore, the present invention has been completed in view of the above-mentioned conventional problems, and an object of the present invention is to effectively suppress the variation in the characteristic impedance of the terminal connected to the optical semiconductor element and suppress the resonance of the high-frequency signal. Thus, a high-frequency signal of 10 to 45 GHz can be passed through the terminal with a reduced loss, and the optical semiconductor element can be normally operated. As a result, it is an object of the present invention to provide an optical semiconductor element package and an optical semiconductor device which can prevent loss of a high-frequency signal due to resonance in high-speed transmission of 10 Gbps or more.
[0016]
[Means for Solving the Problems]
In the optical semiconductor element housing package of the present invention, a flat substrate having a through hole formed in the center from one main surface to the other main surface, and a wiring conductor formed from one side to the other side facing the main surface, A flat plate portion made of an insulator on which an optical semiconductor element is mounted on one side and a standing wall portion made of an insulator joined to the main surface of the flat plate portion with a part of the wiring conductor interposed therebetween; A terminal member fitted to the through hole with the one side being the one main surface side, and a terminal member attached to the one main surface side of the base so as to cover the terminal member, and facing the optical semiconductor element; A cover member to which an optical fiber is fixed at a portion, a heat sink attached to the other main surface of the base so as to surround the terminal member, and a heat sink which is located around the terminal member outside the heat sink. Substantially parallel to the main surface of the flat part Characterized by comprising a pair of metal plates facing one end surface on the exposed major surface of the heat radiating plate in the so that is joined.
[0017]
In the optical semiconductor element housing package of the present invention, a wiring conductor is formed from one side to the other side opposite to the main surface, and a flat plate portion made of an insulator on which the optical semiconductor element is mounted on one side side and a main surface of the flat plate portion are formed. By using the terminal member composed of the standing wall portion made of an insulator joined with a part of the wiring conductor interposed therebetween, variation in the characteristic impedance between the optical semiconductor element and the terminal can be effectively suppressed. . This is because a metal such as W, Mo (molybdenum) -Mn (manganese) can be freely selected as a main component of a wiring conductor formed on a flat plate portion made of an insulator such as ceramics, and a screen printing method can be used. Because the width, length, and thickness of the wiring conductor can be freely adjusted, even if the dielectric constant around the wiring conductor changes, the impedance can be matched according to the dielectric constant of the wiring conductor.
[0018]
Therefore, when it is predicted that an impedance mismatch occurs, the mismatch can be canceled by the wiring conductor. For example, if it can be predicted that the impedance will increase due to a change in the dielectric constant of the insulator, the impedance of the entire signal line can be adjusted by adjusting the width, length, and thickness of the wiring conductor to reduce the impedance. As a result, the insertion loss and the reflection loss of the high frequency signal of 10 GHz or more can be suppressed, and the transmission loss of the high frequency signal of 10 GHz or more can be reduced. Specifically, loss due to variation in characteristic impedance at about 10 GHz can be suppressed to 3 dB or less, and the rise time of a high-frequency signal of a rectangular wave such as a digital signal, which indicates the performance of the optical semiconductor device, is also 35 psec (picoseconds). The following can be achieved:
[0019]
In addition, it has a pair of opposed metal plates that are located around the terminal member outside the heat sink and are substantially parallel to the main surface of the flat plate portion and one end surface of which is joined to the exposed main surface of the heat sink. Therefore, it is possible to effectively suppress the loss due to the reflected wave of the high frequency signal flowing through the portion outside the terminal and the interference wave from the outside. That is, even if a high-frequency signal transmitted from an external terminal and a wiring conductor interferes with a reflected wave from an upright wall or the like to generate a radiated wave, the radiated wave is resonated in a high-frequency region of 10 GHz or more by a pair of metal plates. It is confined so that the phenomenon does not occur, and as a result, loss due to reflected waves and external interference waves can be reduced.
[0020]
Further, the optical semiconductor element housing package of the present invention has a plate-shaped base having a through hole formed from one main surface to the other main surface at the center, and a wiring conductor formed from one side to the other side facing the main surface. A flat portion made of an insulator on which an optical semiconductor element is mounted on one side, and an upright wall portion made of an insulator joined to the main surface of the flat portion with a part of the wiring conductor interposed therebetween, A terminal member fitted to the through hole with the one side being the one main surface side, and a terminal member attached to the one main surface side of the base so as to cover the terminal member and facing the optical semiconductor element; A cover member to which an optical fiber is fixed at a part to be radiated, a heat sink attached to the other main surface of the base so as to surround the terminal member, and a heat sink positioned around the terminal member inside the base and Substantially flat on the main surface of the flat part One end face to the one main surface of the substrate so as to be is characterized by comprising a pair of metal plate opposite joined.
[0021]
The opto-semiconductor element housing package of the present invention is located around the terminal member on the inner side of the base and is opposed to one end surface of which is joined to one main surface of the base so as to be substantially parallel to the main surface of the flat plate portion. Since a pair of metal plates is provided, it is possible to prevent the occurrence of electromagnetic wave resonance caused by a high-frequency signal inside the optical semiconductor device using the optical semiconductor element housing package. That is, it is possible to prevent the radiation wave (electromagnetic wave) of the high-frequency signal inside the container including the base and the lid in which the optical semiconductor element is housed, from rebounding on the lid and the base and generating the resonance of the electromagnetic wave. As a result, a local loss of about 1 dB can be prevented from occurring in the high-frequency band of 10 to 45 GHz, and the high-frequency signal of 10 to 45 GHz can be transmitted with good loss.
[0022]
In the optical semiconductor device of the present invention, an optical semiconductor element is mounted on the one side of the terminal member of the optical semiconductor element housing package of the present invention, and the optical semiconductor element and the light are mounted on the one main surface side of the base. The cover member is attached so as to face the fiber and cover the terminal member.
[0023]
With the above configuration, the optical semiconductor device of the present invention can be used with a reduced transmission loss of a high-frequency signal of 10 to 45 GHz, and has a high performance capable of maintaining stable input and output of a high-frequency signal.
[0024]
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. 1A and 1B show an example of an embodiment of an optical semiconductor device using an optical semiconductor package of the present invention, wherein FIG. 1A is a cross-sectional view of the optical semiconductor device, and FIG. 1B is a cross-sectional view taken along line AA ′ of FIG. FIG. In FIG. 1, 1 is an optical semiconductor package, 2 is a base, 2a is a through hole formed in the base 2, 3 is an optical semiconductor element, 4 is a flat plate portion made of an insulator on which the optical semiconductor element 3 is mounted, and 4a is Wiring conductors 5 formed on one main surface of the flat plate portion 4 are standing wall portions made of an insulator. 6 is a lid provided for hermetically sealing the optical semiconductor element 3, 7 is a lid member having an optical fiber 7a fixed at a position facing the optical semiconductor element 3, 7a is an optical fiber, and 8 is a base 2 A radiator plate 9 joined to the other main surface is a terminal for inputting and outputting a high-frequency signal. Reference numeral 10 denotes a printed wiring board joined to the outer end of the terminal 9, and reference numeral 11 denotes a terminal member. Reference numerals 12 and 12a are metal plates of the present invention.
[0025]
In the optical semiconductor package of the present invention, a flat substrate 2 having a through hole 2a formed from one main surface to the other main surface at the center, and a wiring conductor 4a formed from one side to the other side facing the main surface, A flat portion 4 made of an insulator on which an optical semiconductor element 3 is mounted on one side, and a standing wall portion 5 made of an insulator joined to a main surface of the flat portion 4 with a part of a wiring conductor 4a interposed therebetween; A terminal member 11 fitted into the through hole 2a with one side as one main surface side, and a portion attached to the one main surface side of the base 2 so as to cover the terminal member 11 and facing the optical semiconductor element 3 A cover member 7 to which an optical fiber 7a is fixed, a heat radiating plate 8 attached to the other main surface of the base 2 so as to surround the terminal member 11, and a heat radiating plate 8 Dissipates heat so that it is substantially parallel to the main surface of the flat plate portion 4 One end surface 8 exposed major surface of the are and a pair of metal plates 12 facing joined.
[0026]
Further, in the optical semiconductor package of the present invention, a flat substrate 2 having a through hole 2a formed in the center from one main surface to the other main surface, and a wiring conductor 4a formed in the main surface from one side to the other opposite side. A flat portion 4 made of an insulator on one side of which the optical semiconductor element 3 is mounted, and a standing wall portion 5 made of an insulator joined to the main surface of the flat portion 4 with a part of the wiring conductor 4a interposed therebetween. A terminal member 11 fitted to the through hole 2a with one side as one main surface side, and a terminal member 11 attached to one main surface side of the base 2 so as to cover the terminal member 11 and face the optical semiconductor element 3. A cover member 7 to which an optical fiber 7a is fixed at a portion; a heat sink 8 attached to the other main surface of the base 2 so as to surround the terminal member 11; The base is set so as to be substantially parallel to the main surface of the flat plate portion 4. One end face on one major surface of 2 is provided with a pair of metal plates 12a facing joined.
[0027]
In the optical semiconductor device of the present invention, the mounting portion on which the optical semiconductor element 3 is mounted on the wiring conductor 4a formed from one side of the main surface to the other side opposite to the main surface and on one side where the wiring conductor 4a is not formed. A flat plate portion 4 made of a substantially rectangular parallelepiped insulator and a standing wall portion 5 made of a substantially rectangular parallelepiped insulator joined to a main surface of the flat plate portion 4 so as to sandwich a part of the wiring conductor 4a therebetween. It has a member 11. Providing the terminal member 11 can effectively suppress the characteristic impedance mismatch between the semiconductor element 3 and the terminal 9. This is because a metal such as W or Mo-Mn can be freely selected as a main component of the wiring conductor 4a formed on the flat plate portion 4 made of an insulator such as ceramics. Since the width, length, and thickness can be freely changed, even if the permittivity around the wiring conductor 4a (the flat plate portion 4, the standing wall portion 5) changes, it is possible to effectively suppress the characteristic impedance mismatch. It depends. Therefore, the optical semiconductor device of the present invention can pass a high-frequency signal of 10 GHz or more with low loss.
[0028]
Specifically, the transmission loss at 10 GHz in the related art can be reduced from about 6 dB to about 3 dB in the present invention. As a result, the characteristics do not affect the EYE (eye) characteristics of an optical module using an optical semiconductor device used for optical communication or the like. The EYE characteristic is a characteristic indicating whether or not a digital signal can be transmitted smoothly. A signal pulse generated by a pulse generator is input to an optical module, photoelectrically converted in the optical module, and then converted into an optical signal. The output from the fiber 7a is a characteristic in which the original rectangular wave is distorted and is close to a sine wave or the like, and is obtained by analyzing the optical signal. In this case, when a + side rectangular wave (for example, a signal corresponding to a digital signal "1") and a-side rectangular wave (for example, a signal corresponding to a digital signal "0") are shifted in phase and superimposed, It is called the EYE characteristic because it looks like human eyes.
[0029]
If there is a recognition point such as an overshoot other than the points 1 and 0 (peak value) of the digital signal, it is processed as an error. When there is resonance of the high-frequency signal, the occurrence rate of the error mode increases. The pass / fail judgment of the digital signal is represented by how open the eye-shaped part of the person surrounded by the locus of the rectangular wave is. Generally, the eye-shaped portion of a person is called a window. If a point on the window or a locus that enters the window occurs, that is, if the shape of the window is out of a desired shape, the digital signal is 1,0. Is not determined and an error occurs.
[0030]
In the optical semiconductor device of the present invention, one end surface is joined to the exposed main surface of the heat sink 8 so as to be located around the terminal member 11 outside the heat sink 8 and to be substantially parallel to the main surface of the flat plate portion 4. And a pair of opposed metal plates 12. With this configuration, even if a high-frequency signal transmitted through the terminal 9 and the wiring conductor 4a interferes with a reflected wave from the standing wall 5 or the like to generate a radiated wave, the radiated wave is generated by a pair of metal plates at a frequency of 10 GHz or more. The region is confined so as not to cause a resonance phenomenon, and as a result, loss due to reflected waves and external interference waves can be reduced.
[0031]
Therefore, the rise time of the optical semiconductor device in the high frequency band of 10 to 45 GHz can be reduced to 35 psec or less.
[0032]
In the optical semiconductor device of the present invention, one end surface is joined to one main surface of the base 2 so as to be located around the terminal member 11 inside the base 2 and to be substantially parallel to the main surface of the flat plate portion 4. It has a pair of metal plates 12a facing each other. With this configuration, the radiation wave (electromagnetic wave) of the high-frequency signal inside the container including the base 2 and the lid 6 in which the optical semiconductor element is stored bounces off the lid 6 and the base 2 and the resonance of the electromagnetic wave occurs. Can be prevented. As a result, it is possible to prevent a local loss of about 1 dB from occurring in a high-frequency band of 10 to 45 GHz, reduce a loss of a high-frequency signal of 10 to 45 GHz, and transmit the signal satisfactorily. In the high-frequency band of 45 GHz, the rise time as the optical semiconductor device can be set to 35 psec or less.
[0033]
The metal plates 12 and 12a of the present invention are made of metals such as Cu, Ag, Au, Fe, Ni, Ti, Cr, Mo, W, and Al and alloys of these metals, for example, Fe-Ni-Co alloys and Fe-Ni alloys. , Brass (Cu-Zn alloy), stainless steel, Cu-W, and other alloys. The metal plates 12 and 12a are manufactured into a predetermined shape by applying a conventionally known metal working method such as rolling or punching to an ingot of the metal or alloy. A Ni layer having a thickness of 0.5 to 9 μm and an Au layer having a thickness of 0.5 to 5 μm having excellent corrosion resistance and excellent wettability with a brazing material are sequentially deposited on the surfaces of the metal plates 12 and 12a by plating. It is preferable that the metal plates 12, 12a are effectively prevented from being oxidized and corroded, and that each component can be satisfactorily brazed to the metal plates 12, 12a.
[0034]
The metal plate 12 is preferably installed so as to cover the main surface of the terminal member 11 and the main surface of the terminal 9 as shown in FIG. In this case, loss of the high-frequency signal transmitted by the wiring conductor 4a and the terminal 9 can be effectively suppressed. Further, the metal plate 12 and the metal plate 12a may be provided in one optical semiconductor device. In this case, the loss due to the reflected wave of the high-frequency signal transmitted at the terminal 9 and the interference wave from the outside can be suppressed, and the occurrence of resonance of the high-frequency signal inside the optical semiconductor device can be suppressed. Can be smaller.
[0035]
In addition, the metal plate 12 is preferably in contact with the terminal member 11, which effectively suppresses radiation loss of a high-frequency signal and facilitates heat transfer and heat dissipation of the optical semiconductor element 3 to the outside. Further, the metal plate 12a is preferably in contact with the terminal member 11. In this case, the interval between the metal plates 12a is reduced, and the resonance frequency of the high frequency signal can be shifted to the high frequency side, and the influence of resonance is reduced. can do.
[0036]
When the metal plate 12 and the metal plate 12a are provided in one optical semiconductor device, the metal plate 12 is preferably thicker than the metal plate 12a, and the heat of the optical semiconductor element 3 is quickly stored without being stored in the thin metal plate 12a. The metal plate 12 which is conductive and has a large volume allows heat to be stored to some extent outside the optical semiconductor device and to be easily dissipated.
[0037]
The base 2 is made of a metal such as an Fe—Ni—Co alloy. The base 2 is manufactured into a predetermined shape by subjecting the metal ingot to a conventionally known metal working method such as rolling or punching. A substantially rectangular through hole 2a for fitting the terminal member 11 is formed in the center of the base 2. On the surface of the substrate 2, a Ni layer having a thickness of 0.5 to 9 μm and an Au layer having a thickness of 0.5 to 5 μm having excellent corrosion resistance and excellent wettability with a brazing material are sequentially deposited by plating. It is preferable that the components are effectively prevented from being oxidized and corroded, and that each component can be satisfactorily brazed to the substrate 2.
[0038]
The terminal member 11 provided on the base 2 has a flat plate portion 4 made of a substantially rectangular parallelepiped insulator having a wiring conductor 4a formed of a metallized layer or the like formed on one main surface, and a flat plate portion with a part of the wiring conductor 4a interposed therebetween. And an upright wall portion 5 formed of a substantially rectangular parallelepiped insulator and joined to one main surface of the portion 4 to block the inside and outside of the base 2. The flat plate portion 4 and the standing wall portion 5 are made of an insulator such as an aluminum oxide sintered body (aluminum oxide ceramics), an aluminum nitride sintered body, or a glass ceramic.
[0039]
A wiring conductor 4 a is formed on one main surface of the flat plate portion 4, and the optical semiconductor element 3 is mounted on one side of one main surface of the flat plate portion 4. The optical semiconductor element 3 is electrically connected to the wiring conductor 4 a by a bonding wire, and is electrically connected to an external electric circuit via the terminal 9. The wiring conductor 4a and the grounding conductor formed on the flat plate portion 4 are made of W, Mo, Mn, or the like. For example, a metal paste obtained by adding an organic solvent or a solvent to a powder of W or the like is used as a ceramic for forming the flat plate portion 4. It is formed by printing and applying a predetermined pattern on a green sheet by a screen printing method, laminating and firing the ceramic green sheet. On the surface of the wiring conductor 4a or the ground conductor, a Ni layer having a thickness of 0.5 to 9 μm or an Au layer having a thickness of 0.5 to 5 μm is formed on the surface of the wiring conductor 4a or the ground conductor in order to prevent oxidation and to firmly connect the bonding wires and the terminals 9 and the like. Preferably, metal layers such as layers are sequentially applied by a plating method.
[0040]
The optical semiconductor element 3 is hermetically sealed by joining a lid 6 made of an Fe-Ni-Co alloy or the like to an outer peripheral portion of one main surface of the base 2 made of an Fe-Ni-Co alloy or the like by seam welding or the like. Is stopped.
[0041]
The radiator plate 8 is preferably made of a metal having a thermal conductivity of 150 W / mK or more. The thermal conductivity of the radiator plate 8 is preferably 100 W / mK or more higher than that of the base 2. / MK (Fe-Ni-Co alloy or the like), and the thermal conductivity of the heat sink 8 is 180 W / mK (Cu-W alloy or the like). This is to prevent heat generated when the lid 6 and the base 2 are welded and sealed from being diffused to the radiator plate 8 to prevent the temperature of the welded portion from lowering and making smooth sealing difficult. It is. When the heat conductivity of the heat sink 8 is higher than that of the substrate 2 by 100 W / mK or more, good welding sealing can be performed regardless of a welding method such as seam welding or YAG laser welding. That is, if heat is diffused when the lid 6 is melted and welded, the portion of the lid 6 to be welded becomes difficult to melt, and smooth sealing cannot be performed. If the rate is higher than the base 2 by 100 W / mK or more, such a problem is solved.
[0042]
The thickness of the base 2 is preferably 0.5 mm or more. If it is less than 0.5 mm, when the terminal member 11 is fitted into the through-hole 2a of the base 2 and joined by brazing or the like and the lid 6 is welded to the base 2, the base 2 may be welded depending on welding conditions (temperature, etc.). The optical semiconductor package is easily deformed due to bending, and the welding strength and the bonding strength of the terminal member 11 are deteriorated, so that a problem is likely to occur in the hermetic sealing of the optical semiconductor package.
[0043]
When the optical semiconductor package 1 of the present invention is used for optical communication in which an optical semiconductor element 3 such as an LD or PD and a semiconductor element such as an LSI are housed, a through hole 2a penetrating through the inside and outside of the base 2 is formed. 2a, a flat plate portion 4 made of a substantially rectangular parallelepiped insulator having a wiring conductor 4a formed on the main surface and a portion of the wiring conductor 4a interposed therebetween and joined to the main surface of the flat plate portion 4 so that the inside and outside of the base 2 A terminal member 11 composed of a standing wall portion 5 made of a substantially rectangular parallelepiped insulator to be interrupted is fitted and joined. Then, the optical semiconductor element 3 is mounted on the flat plate portion 4 and connected to the wiring conductor 4a by a bonding wire. Thereafter, the lid 6 is joined to one main surface of the base 2 by seam welding or the like. Thereafter, the lid member 7 in which the optical fiber 7a and the optical isolator 7b for preventing return light are bonded to the outer peripheral portion (flange-shaped portion) of the lid body 6 with a resin adhesive is bonded by YAG laser welding or the like. Thereby, an optical semiconductor device as a product is obtained. The semiconductor device is electrically connected to a printed wiring board 10 and the like via terminals 9.
[0044]
Thus, in the optical semiconductor package 1 of the present invention, the characteristic impedance is matched by adjusting the dielectric constant of the terminal member 11 made of an insulator such as ceramics, the main component, the width, the length, and the thickness of the wiring conductor 4a. The transmission loss of the high-frequency signal can be reduced, and the high-frequency signal can be transmitted smoothly. Further, by using the metal plates 12 and 12a, transmission loss in a high frequency band of 10 to 45 GHz can be suppressed, and a high frequency signal can be transmitted stably and smoothly. As a result, when an optical semiconductor device is formed using the optical semiconductor package 1 of the present invention, a high-frequency signal input / output to / from the optical semiconductor element 3 can be efficiently transmitted.
[0045]
【Example】
Embodiments of an optical semiconductor element storage package and an optical semiconductor device according to the present invention will be described below.
[0046]
The optical semiconductor device of FIG. 1 was configured as follows. First, a wiring conductor 4a and W serving as a grounding conductor are formed on one main surface and side surfaces of a rectangular parallelepiped ceramic green sheet laminate A containing alumina as a main component and serving as a flat plate portion 4 having a thickness of 1 mm × 4.5 mm × 3 mm. The paste is printed and applied by a screen printing method, and a rectangular parallelepiped ceramic green sheet laminate B containing alumina as a main component and having a thickness of 1 mm × 1.5 mm × 3 mm is mainly used as one of the ceramic green sheet laminates A. The terminal member 11 was produced by laminating on the main surface and firing at the same time. The obtained terminal member 11 had a length of 4.5 mm and a thickness of 2 mm, the relative permittivity of the flat plate portion 4 and the standing wall portion 5 was 9, and the width of the wiring conductor 4a formed of a metallized layer of W was 3 mm. Was.
[0047]
The base 2 was formed by processing a 1 mm thick Fe—Ni—Co alloy ingot into a disk having a thickness of 1 mm and a diameter of 4.6 mm. A rectangular through hole 2a for fitting the terminal member 11 was formed in the center of the base 2 by punching. On the surface of the substrate 2, a Ni layer having a thickness of 2 μm and an Au layer having a thickness of 2 μm were sequentially applied by a plating method. The heat radiating plate 8 is made of a Cu-W alloy and has a disk shape with a thickness of 1 mm and a diameter of 4.6 mm, and a through hole for inserting the terminal member 11 is formed at a central portion thereof. Was joined to the other main surface with Ag brazing.
[0048]
Then, the terminal member 11 was fitted into the through-hole 2a of the base 2 and the through-hole of the radiator plate 8, and was fitted and joined by joining with an Ag braze.
[0049]
The metal plate 12 is formed by processing an ingot of a Fe-Ni-Co alloy having a thickness of 1 mm, and has a thickness of 1 mm, a length (length in a direction parallel to the transmission direction of the high-frequency signal) of 4 mm, and a width (of the high-frequency signal). (Length in the direction perpendicular to the transmission direction) 4 mm. Similarly, a metal plate 12a having a thickness of 1 mm, a length of 6 mm, and a width of 6 mm was produced.
[0050]
Thereafter, a pair of metal plates 12 facing the exposed main surface of the heat radiating plate 8 were joined via an Ag brazing so as to be substantially parallel to the flat plate portion 4 of the terminal member 11 and to be in contact with the terminal member 11.
[0051]
Next, the optical semiconductor element 3 as an LD is mounted on one end of the wiring conductor 4a on one main surface of the flat plate portion 4 by soldering, and the optical semiconductor element 3 and the wiring conductor 4a are electrically connected with a bonding wire. Connected. In addition, a pair of metal plates 12 a facing one main surface of the base 2 were joined via an Ag brazing so as to be substantially parallel to the flat plate portion 4 of the terminal member 11 and to be in contact with the terminal member 11.
[0052]
Then, a lid 6 made of an Fe—Ni—Co alloy was joined to the outer peripheral portion of one main surface of the base 2 by seam welding and hermetically sealed. Thereafter, the lid member 7 in which the optical fiber 7a and the optical isolator 7b were bonded to the outer peripheral end portion of the lid body 6 with a resin adhesive was joined by YAG laser welding to produce an optical semiconductor device.
[0053]
Table 1 and the graph of FIG. 3 show the results of calculating the resonance frequency generated by the distance between the metal plates 12a by simulation for this optical semiconductor device.
[0054]
The resonance frequency is calculated by fc = Co / 2 ｛(1 / a) 2 + (1 / b) 2 + (1 / c) 2 １ ／ 1/2 (fc: resonance frequency, a: metal plate 12a Width, b: distance between metal plates 12a, c: length of metal plate 12a, Co: 2.998 × 10 8 m / s), substituting 3 mm, 4 mm, 5 mm, and 6 mm for a and c, respectively. I did it. Thereby, the interval b between the metal plates 12a at which no resonance point occurs between 10 and 45 GHz was derived. Further, in FIG. 3, crosses indicate data of a and c of 4 mm, triangles indicate data of a and c of 5 mm, and squares indicate data of a and c of 6 mm.
[0055]
[Table 1]
[0056]
From Table 1, it was found that in the sample where a and c were 5 mm, the resonance frequency exceeded 45 GHz when b was 9 mm or less, and no resonance point was generated at 10 to 45 GHz. In the samples with a and c of 6 mm, it was found that the resonance frequency exceeded 45 GHz when b was 5 mm or less, and that no resonance point was generated at 10 to 45 GHz.
[0057]
In addition, it was found that the resonance frequency exceeds 45 GHz and the resonance point does not occur at 10 to 45 GHz when b is 12 mm or less between the sample in which a and c are 3 mm and the sample in which a and c are 4 mm. Therefore, it is preferable that a and c be 4 mm or less.
[0058]
Without the metal plate 12a, the inner dimension of the cover 6 covering the optical semiconductor element 3 would be 4 mm or more, so that the optical semiconductor device generated resonance at a resonance frequency of 36.4 GHz.
[0059]
It should be noted that the present invention is not limited to the above-described embodiments and examples, and various changes may be made without departing from the spirit of the present invention.
[0060]
【The invention's effect】
In the optical semiconductor element housing package of the present invention, a flat substrate having a through hole formed in the center from one main surface to the other main surface, and a wiring conductor formed from one side to the other side facing the main surface, A flat plate portion made of an insulator on which an optical semiconductor element is mounted on one side, and an upright wall portion made of an insulator joined to a main surface of the flat plate portion with a part of a wiring conductor interposed therebetween, A terminal member fitted as one main surface side, and a lid member attached to the one main surface side of the base so as to cover the terminal member, and an optical fiber is fixed to a portion facing the optical semiconductor element. A radiating plate attached to the other main surface of the base member so as to surround the terminal member, and a radiating plate which is located around the terminal member outside the radiating plate and is substantially parallel to the main surface of the flat plate portion. A pair of opposed main surfaces with one end surface joined to the main surface By providing the genus plate, it is possible to suppress variations in the characteristic impedance between the optical semiconductor element and the terminal effectively. This is because a metal such as W or Mo-Mn can be freely selected as a main component of a wiring conductor formed on a flat plate portion made of an insulator such as ceramics, and the width and length of the wiring conductor can be determined by screen printing. Since the thickness can be freely adjusted, even if the dielectric constant around the wiring conductor changes, the impedance can be matched according to the dielectric constant of the wiring conductor.
[0061]
Therefore, when it is predicted that an impedance mismatch occurs, the mismatch can be canceled by the wiring conductor. For example, if it can be predicted that the impedance will increase due to a change in the dielectric constant of the insulator, the impedance of the entire signal line can be adjusted by adjusting the width, length, and thickness of the wiring conductor to lower the impedance. As a result, insertion loss and reflection loss of a high frequency signal of 10 GHz or more can be suppressed, and transmission loss of a high frequency signal of 10 GHz or more can be reduced. Specifically, loss due to variation in characteristic impedance at about 10 GHz can be suppressed to 3 dB or less, and the rise time of a high-frequency signal of a rectangular wave such as a digital signal, which indicates the performance of the optical semiconductor device, also achieves 35 psec or less. be able to.
[0062]
In addition, since there is a pair of metal plates facing each other, it is possible to effectively suppress a loss due to a reflected wave of a high-frequency signal flowing through a portion outside the terminal and an interference wave from the outside. That is, even if a high-frequency signal transmitted from an external terminal and a wiring conductor interferes with a reflected wave from an upright wall or the like to generate a radiated wave, the radiated wave is resonated in a high-frequency region of 10 GHz or more by a pair of metal plates. It is confined so that a phenomenon does not occur, and as a result, loss due to reflected waves and external interference waves can be reduced.
[0063]
Further, the optical semiconductor element housing package of the present invention has a plate-shaped base having a through hole formed from one main surface to the other main surface at the center, and a wiring conductor formed from one side to the other side facing the main surface. A flat portion made of an insulator on which an optical semiconductor element is mounted on one side, and an upright wall portion made of an insulator joined to a main surface of the flat portion with a part of a wiring conductor interposed therebetween, and one side of the through hole is formed. A terminal member fitted with one side as one main surface side, and a cover member attached to one main surface side of the base so as to cover the terminal member, and an optical fiber is fixed to a portion facing the optical semiconductor element And a heat sink attached to the other main surface of the base so as to surround the terminal member, and a heat sink positioned around the terminal member inside the base and substantially parallel to the main surface of the flat plate portion. A pair of opposing metals with one end joined to the surface By providing the door, the electromagnetic wave resonance of due to high frequency signals within an optical semiconductor device using the optical semiconductor element housing package can be prevented from occurring. That is, it is possible to prevent the radiation wave (electromagnetic wave) of the high-frequency signal inside the container including the base and the lid in which the optical semiconductor element is housed, from rebounding on the lid and the base and generating the resonance of the electromagnetic wave. As a result, a local loss of about 1 dB can be prevented from occurring in the high-frequency band of 10 to 45 GHz, and the high-frequency signal of 10 to 45 GHz can be transmitted with good loss.
[0064]
The optical semiconductor device of the present invention has an optical semiconductor element mounted on one side of the terminal member of the optical semiconductor element housing package of the invention, and the optical semiconductor element and the optical fiber are opposed to one main surface of the base. By attaching a lid member so as to cover the terminal member, it is possible to use the transmission loss of the high-frequency signal of 10 to 45 GHz small and to use it, and to maintain a stable input and output of the high-frequency signal. It becomes.
[Brief description of the drawings]
FIGS. 1A and 1B show an example of an embodiment of an optical semiconductor device of the present invention, wherein FIG. 1A is a cross-sectional view of the optical semiconductor device, and FIG. 1B is a cross-sectional view taken along line AA ′ of FIG.
2A and 2B show an example of a conventional optical semiconductor device, wherein FIG. 2A is a cross-sectional view of the optical semiconductor device, and FIG. 2B is a cross-sectional view taken along line AA ′ of FIG.
FIG. 3 is a graph showing a relationship between an interval b between metal plates and a resonance frequency in the optical semiconductor device of the present invention.
[Explanation of symbols]
1: Package for housing optical semiconductor element 2: Base 2a: Through hole 3: Optical semiconductor element 4: Flat plate section 4a: Wiring conductor 5: Standing wall section 6: Lid 7: Lid member 8: Heat sink 11: Terminal member 12, 12a: metal plate
