【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し、特に外部電気回路基板への実装構造を改良したものに関する。
【０００２】
【従来の技術】
従来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、単にパッケージともいう）を図３，図４に示す。図３はパッケージの平面図、図４は図３のＢ−Ｂ’線における断面図である。これらの図において、２１は四角形状の基体、２２は枠体、２３は光ファイバ固定部材（以下、単に固定部材ともいう）、２４は入出力端子、２６は蓋体を示し、これら基体２１、枠体２２および蓋体２６とで、内部空間に光半導体素子３１を収容する容器が基本的に構成される。
【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、その上側主面の中央部には、半導体レーザ（ＬＤ），フォトダイオード（ＰＤ）等の光半導体素子３１を載置固定するための載置部２１ａが設けられる。また、基体２１の四隅を同一面でもって外側に延出して設けられた延出部に貫通孔２１ｃが形成されて成るネジ取付部２１ｂが設けられている。この基体２１は、貫通孔２１ｃにネジを通して外部電気回路基板にネジ止めして固定される。
【０００４】
基体２１の上側主面の外周部には、載置部２１ａを囲繞するようにして接合され、側部に貫通穴２２ａが形成された枠体２２が立設されている。この枠体２２は、基体２１と同様にＦｅ−Ｎｉ−Ｃｏ合金やＣｕ−Ｗ合金等の金属から成り、基体２１と一体成形される、または基体２１に銀（Ａｇ）ロウ等のロウ材を介してロウ付けされる、またはシーム溶接法等の溶接法により接合されることによって、基体２１の上側主面の外周部に立設されている。
【０００５】
また、枠体２２の側部には、固定部材２３が貫通穴２２ａに嵌着されて取り付けられている。固定部材２３は、光ファイバ２８を枠体２２の側部に固定するための筒状の部材であり、Ｆｅ−Ｎｉ−Ｃｏ合金やステンレス鋼（ＳＵＳ）等の金属から成り、固定部材２３には中心軸方向に形成された貫通孔２３ａが設けられており、固定部材２３の外周面が枠体２２の貫通穴２２ａの内面にロウ材を介して嵌着接合されている。
【０００６】
さらに、枠体２２の貫通穴２２ａが形成された側部に隣接する側部には入出力端子２４を取り付けるための切欠き部または貫通孔から成る取付部２２ｂが形成されている。この取付部２２ｂには、アルミナ（Ａｌ２Ｏ３）質焼結体、窒化アルミニウム（ＡｌＮ）質焼結体、ムライト（３Ａｌ２Ｏ３・２ＳｉＯ２）質焼結体等のセラミックスから成る入出力端子２４がロウ材を介して嵌着接合され、枠体２２の内外を導通する多数の線路導体２４ａが被着形成されている。
【０００７】
このようなパッケージは、枠体２２および入出力端子２４の上面に、Ｆｅ−Ｎｉ−Ｃｏ合金等の金属から成るシールリング２５がＡｇろう等のロウ材を介して接合される。また、載置部２１ａには光半導体素子３１がペルチェ素子や回路基板等の基台３０を介して載置され、光半導体素子３１の各電極がボンディングワイヤ３２を介して線路導体２４ａの枠体２２内側の部位に電気的に接続される。そして、ホルダー２７に固定された光ファイバ２８が固定部材２３に挿通されて、ホルダー２７が固定部材２３に溶接固定されることにより光ファイバ２８の光入出力端面と光半導体素子３１の光入出力端面とが光結合される。しかる後、シールリング２５の上面にＦｅ−Ｎｉ−Ｃｏ合金等から成る蓋体２６がシーム溶接法等の溶接法により接合されて光半導体素子３１を気密に封止することによって、製品としての光半導体装置が完成される。
【０００８】
この光半導体装置は、ネジ取付部２１ｂの貫通孔２１ｃにネジを通して基体２１を外部電気回路基板（図示せず）にネジ止め固定し、入出力端子２４の枠体２２の外側の線路導体２４ａと外部電気回路とを電気的に接続した後、外部電気回路から電気信号によって光半導体素子３１で光を励起させ、この光を光ファイバ２８を介して外部に伝送することによって、または、外部から光ファイバ２８を通って伝送してきた光信号を、光半導体素子３１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光電変換素子として作動することができ、高速光通信等に使用される。
【０００９】
しかしながら、このような光半導体装置は、貫通孔２１ｃにネジを挿入して外部電気回路基板にネジ止め固定する際、ネジの締め付けによりネジ取付部２１ｂに応力が発生し、この応力が基体２１や枠体２２に伝わってパッケージに歪みが生じ、その結果、光ファイバ２８と光半導体素子３１との光軸がずれて光結合効率が劣化するという問題点を有していた。
【００１０】
このような問題点を解決するため、ネジ取付部２１ｂを基体２１と別体とし、基体２１よりも縦弾性係数の低い材質、例えば、Ｃｕ，Ｃｕ合金，アルミニウム（Ａｌ），Ａｌ合金等で形成し、基体２１にＡｇロウ付けした構成が提案されている（例えば、下記の特許文献１参照）。これにより、パッケージをネジ止め固定する際、ネジ取付部２１ｂをネジで締め付けても、ネジ取付部２１ｂが主に変形して基体２１の変形が抑えられ、光半導体素子３１と光ファイバ２８との光結合効率の低下を抑制することができる。
【００１１】
【特許文献１】
特開平６−８２６５９号公報
【００１２】
【発明が解決しようとする課題】
しかしながら、上記特許文献１に示されるパッケージは、ネジ止め固定する際、ネジ取付部２１ｂをネジで締め付けても、ネジ取付部２１ｂが主に変形して基体２１の変形が抑えられるものの、ネジ取付部２１ｂと基体２１との接合部には応力が集中し易く、その応力によりネジ取付部２１ｂと基体２１との接合部において剥離が生じ、パッケージが破損するという問題点を有していた。
【００１３】
また、基体２１と枠体２２とがほぼ同一の平均線膨張係数であり、かつ基体２１の上側主面に枠体２２が接合されているため、パッケージを作製する際、加熱してロウ付けした後冷却する時に、枠体２２側が拘束されて基体２１が載置部２１ａを枠体２２との接合部よりも下側に位置するように反り易くなる。そのため、このパッケージに光半導体素子３１を搭載し、光ファイバ２８と光軸を調整した後、パッケージを外部電気回路基板に搭載すると、基体２１の反りの頂点が外部電気回路基板に接触し、この接触点を支点としてネジ取付部２１ｂから基体２１の反りを押し広げるように応力が加わって基体２１が変形し、光半導体素子３１と光ファイバ２８との光結合効率が大きく劣化するという問題点をも有していた。
【００１４】
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、光半導体素子収納用パッケージのネジ止めにより、光半導体素子収納用パッケージに歪が生じるのを有効に抑制し、ＬＤ，ＰＤ等の光半導体素子の光入出力端面と光ファイバの光入出力端面との間における光信号の授受を正常に維持させ、光結合効率の優れた光半導体素子収納用パッケージおよび光半導体装置を提供することにある。
【００１５】
【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、上側主面に光半導体素子が載置される載置部が形成されているとともに四隅部にネジ取付部が形成された四角形状の金属製の基体と、該基体の前記上側主面の外周部で前記ネジ取付部よりも内側に前記載置部を囲繞するように接合され、側部に光ファイバを固定するための貫通穴が形成された金属製の枠体と、前記貫通穴に嵌着されるかまたは前記貫通穴の前記枠体外面側の開口の周囲に一端が接合された筒状の光ファイバ固定部材とを具備しており、前記基体は、前記貫通穴の側の一端とそれに対向する他端とが前記載置部よりも下側に位置するように反っていることを特徴とする。
【００１６】
本発明の光半導体素子収納用パッケージは、基体の貫通穴の側の一端とそれに対向する他端とが載置部よりも下側に位置するように反っていることから、載置部に載置した光半導体素子と光ファイバとを光結合させた後、光半導体素子収納用パッケージを外部電気回路基板にネジ止めしても、基体の載置部が上に凸となるようにして反っているため、基体の枠体内側の部位は外部電気回路基板と接触することがなく、基体の反りを押し広げるような応力の支点は枠体内側の部位には存在しなくなる。即ち、基体が反った状態を維持しながら外部電気回路基板にネジ止めされることとなり、光半導体素子と光ファイバとの光結合効率の劣化を効果的に抑制することができる。
【００１７】
また、ネジ取付部は基体と一体になっているため、ネジ取付部が基体から剥離することなく、枠体との接合部を支点として適度に変形することが可能となる。従って、ネジ取付部が外部回路基板の形状に合わせて適度に変形して、基体の枠体内側の部位に応力を伝えたり、歪みを発生させたりすることなく、光半導体素子収納用パッケージを外部電気回路基板にネジ止めすることが可能となり、光半導体素子の光入出力端面と光ファイバの光入出力端面との間における光信号の授受を正常に維持させ、光結合効率の優れたものとすることができる。
【００１８】
本発明の光半導体装置は、上記本発明の光半導体素子収納用パッケージと、前記光ファイバ固定部材に挿入され固定された光ファイバと、該光ファイバに光学的に結合するように前記載置部に載置された光半導体素子と、前記枠体の上面に接合された蓋体とを具備していることを特徴とする。
【００１９】
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光結合効率の優れたものとなる。
【００２０】
【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について以下に詳細に説明する。図１は本発明のパッケージについて実施の形態の一例を示す平面図、図２は図１のＡ−Ａ’線における断面図である。これらの図において、１は基体、２は枠体、３は固定部材、４は入出力端子、５はシールリング、６は蓋体を示し、これら基体１、枠体２、入出力端子４および蓋体６とで、内部に光半導体素子１１を収容する容器が基本的に構成される。
【００２１】
本発明のパッケージは、上側主面に光半導体素子１１が載置される載置部１ａが形成されているとともに四隅部にネジ取付部１ｂが形成された四角形状の金属製の基体１と、この基体１の上側主面の外周部でネジ取付部１ｂよりも内側に載置部１ａを囲繞するように接合され、側部に光ファイバ８を固定するための貫通穴２ａが形成された金属製の枠体２と、貫通穴２ａに嵌着されるかまたは貫通穴２ａの枠体２外面側の開口の周囲に一端が接合された筒状の光ファイバ固定部材３とを具備しており、基体１は、貫通穴２ａの側の一端とそれに対向する他端とが載置部１ａよりも下側に位置するように反っている。
【００２２】
基体１は、上側主面の載置部１ａを頂点としてこの載置部１ａから貫通穴２ａの側の両端にわたって滑らかな曲面となるように反っているのがよい。これにより、パッケージを外部電気回路にネジ止めする際、基体１の枠体２の内側の部位を変形させたり歪ませたりすることなく、枠体２の外側の部位のみを外部電気回路基板の表面形状に合わせて適度に変形させることができる。
【００２３】
基体１の反りの大きさ、即ち、基体１の上側主面の反りの頂点と枠体２の下面全面に接する平面貫通穴２ａの側の両端同士で形成される平面との距離は、１乃至５０μｍであるのがよい。１μｍ未満であると、基体１の枠体２の内部領域の部位が外部電気回路基板と接触し、外部電気回路基板の歪みによって基体１が変形し易くなり、光半導体素子１１と光ファイバ８との光軸がずれ易くなる。また、５０μｍを超えると、載置部１ａに光半導体素子１１を固定し難くなるとともに、パッケージを外部電気回路基板にネジ止めする際、基体１の枠体２の外側の部位が大きく変形し、この変形による応力が載置部１ａに伝わって光半導体素子１１と光ファイバ８との光軸がずれ易くなる。
【００２４】
基体１は、Ｆｅ−Ｎｉ−Ｃｏ合金、Ｃｕ−Ｗ合金等の金属材料から成り、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。基体１の四隅には外側に延出したネジ取付部１ｂが形成されており、ネジ取付部１ｂにはネジ挿入用の貫通孔１ｃが形成されている。
【００２５】
基体１は、平板上の金属材料を金型等でプレスして変形させることによって、または金属射出成型等の方法で成型することによって、貫通穴２ａの側の一端とそれに対向する他端とが載置部１ａよりも下側に位置するように反らせることができる。あるいは、基体１の材料を枠体２よりも弾性率の低いものとすることにより、枠体２，入出力端子４および基体１を加熱接合した後の冷却時に基体１が大きく収縮する際、枠体２および入出力端子４は変形し難いのに対し、基体１は変形し易いために上に凸となるように反った状態にすることができる。
【００２６】
基体１は、好ましくは、Ｃｕを１５％〜２０％含有するＣｕ−Ｗ合金とするのがよい。これにより、基体１を適度に軟らかくして貫通穴２ａの側の一端とそれに対向する他端とが載置部１ａよりも下側に位置するように容易に反らせることが可能となる。また、ネジ取付部１ｂを基体１と枠体２との接合部を支点として適度に変形し易くして、載置部１ａに応力が伝わるのを抑制することができる。さらに、このような基体１は熱放散性にも優れるため、より安定に光半導体素子１１を駆動させることができる。
【００２７】
基体１は、貫通穴２ａの側の一端とそれに対向する他端とが載置部１ａよりも下側に位置するように反っていることから、載置部１ａに載置した光半導体素子１１と光ファイバ８とを光結合させた後、パッケージを外部電気回路基板にネジ止めしても、基体１の載置部１ａが上に凸となるようにして反っているため、基体１の枠体２内側の部位は外部電気回路基板と接触することがなく、基体１の反りを押し広げるような応力の支点は枠体２内側の部位には存在しなくなる。即ち、基体１が反った状態を維持しながら外部電気回路基板にネジ止めされることとなり、光半導体素子１１と光ファイバ８との光結合効率の劣化を効果的に抑制することができる。
【００２８】
また、ネジ取付部１ｂは基体１と一体になっているため、ネジ取付部１ｂが基体１から剥離することなく、枠体２との接合部を支点として適度に変形することが可能となる。従って、ネジ取付部１ｂが外部回路基板の形状に合わせて適度に変形して、基体１の枠体２内側の部位に応力を伝えたり、歪みを発生させたりすることなく、パッケージを外部電気回路基板にネジ止めすることが可能となり、光半導体素子１１の光入出力端面と光ファイバ８の光入出力端面との間における光信号の授受を正常に維持させ、光結合効率の優れたものとすることができる。
【００２９】
ネジ取付部１ｂの平面視形状は、図１に示すように、基体１の対向する２つの辺部をそれぞれ枠体２よりも外側に延出させたものでもよく、また基体１の四隅をそれぞれ枠体２よりも外側に張り出すように延出させ、各延出部に１個ずつ貫通孔１ｃを形成したものでもよい。
【００３０】
また、基体１の上面の載置部１ａには、ＬＤ，ＰＤ等の光半導体素子１１が載置固定される。基体１は、光半導体素子１１が作動時に発する熱を外部に放熱させる放熱板としての役割も果たす。なお、光半導体素子１１は、作動時に発生する熱を効率よく基体１を介して外部へ放熱させるために、ペルチェ素子や回路基板等の基台１０に搭載された状態で載置部１ａに載置固定されてもよい。
【００３１】
なお、基体１の表面には、酸化腐食の防止や光半導体素子１１の載置固定を良好にするために、厚さ０．５〜９μｍのＮｉ層や厚さ０．５〜５μｍの金（Ａｕ）層からなる金属層をめっき法等により被着させておくとよい。
【００３２】
枠体２は平面視形状が四角形の枠状体で、基体１の上側主面の外周部でネジ取付部１ｂよりも内側に載置部１ａを囲繞するように接合され、側部に貫通穴２ａおよび取付部２ｂが形成されている。貫通穴２ａは固定部材３を支持するものであり、また、取付部２ｂは入出力端子４を支持するものである。このような枠体２は、基体１と同様にＦｅ−Ｎｉ−Ｃｏ合金やＣｕ−Ｗの合金等から成り、基体１にＡｇロウ等のロウ材を介してロウ付けされる、またはシーム溶接法等の溶接法により接合されることにより、基体１の上側主面の外周部に立設される。
【００３３】
枠体２は、基体１とともにその内側に光半導体素子１１を収容する空所を形成するとともに、その側部の貫通穴２ａに嵌着されるかまたは貫通穴２ａの枠体２外側の開口の周囲に一端が接合された筒状の固定部材３を介して光ファイバ８を支持固定する。
【００３４】
固定部材３は、光ファイバ８を枠体２の側部に固定するための円筒状等の筒状の部材であり、Ｆｅ−Ｎｉ−Ｃｏ合金やステンレス鋼等の金属から成る。固定部材３は、中心軸方向に光ファイバ８を挿入するための貫通孔３ａが設けられており、枠体２の側部の貫通穴２ａの内面に外周面がロウ材を介して嵌着されるかまたは貫通穴２ａの枠体２外側の開口の周囲に一端がロウ材を介して接合されることにより、枠体２の側部に固定される。
【００３５】
入出力端子４は、長方形の平板部の上面に、四角柱状の立壁部が積層されており、Ａｌ２Ｏ３質セラミックス，ＡｌＮ質セラミックス，３Ａｌ２Ｏ３・２ＳｉＯ２質セラミックス等の誘電体から成る部材である。この入出力端子４は枠体２の取付部２ａに嵌め込まれるとともに、入出力端子４と取付部３ａとの隙間に溶融したＡｇろう等のロウ材を毛細管現象により充填させることで、枠体２に嵌着接合される。入出力端子４の平板部の上面には、枠体２内外を導通するＷ，モリブデン（Ｍｏ）等のメタライズ層から成る線路導体４ａが被着形成されており、枠体２の一部となって枠体２内外を気密に仕切るとともに、枠体２内外を導通させる導電路としての機能を有する。
【００３６】
ネジ取付部１ｂは、光ファイバ８が固定される貫通穴２ａが形成された枠体２の側部側およびこの側部に対向する枠体２の側部側に設けられているのがよい。これにより、パッケージを外部電気回路基板にネジ止め固定した際に発生する応力が、光ファイバ８が固定されている枠体２の側部に加わるのを抑制することができる。即ち、互いに逆の方向に延出した２つのネジ取付部１ｂの間に位置する部分において基体１の曲げ応力が最も大きくなり易いのに対し、枠体２の同じ側部側にある２つのネジ取付部１ｂの間に位置する部分においては基体１の曲げ応力は小さく、この曲げ応力の小さい部分に対応する枠体２の側部で光ファイバ８を固定することにより、光ファイバ８の位置がずれるのを有効に抑制することができる。
【００３７】
また、貫通孔１ｃの平面視形状は、図１に示すような円形である必要はなく、四角形や半円形等であってもよい。
【００３８】
本発明の光半導体装置は、上記構成のパッケージと、固定部材３に挿入され固定された光ファイバ８と、この光ファイバ８に光学的に結合するように載置部１ａに載置された光半導体素子１１と、枠体２の上面に接合された蓋体６とを具備している。
【００３９】
このような光半導体装置は以下のようにして作製される。先ず、上記構成のパッケージに光半導体素子１１をペルチェ素子や回路基板等の基台１０を介して載置部１ａに載置固定した後、光半導体素子１１の電極と、枠体２の側部または基体１に設けられた、パッケージの内外の導電路として機能する入出力端子４の枠体２内側の線路導体４ａとを、ボンディングワイヤ１２で電気的に接続し、枠体２の上部に接合されたシールリング５の上面にＦｅ−Ｎｉ−Ｃｏ合金等の金属，セラミックス，樹脂等から成る蓋体６をロウ付け法やシームウエルド法等の溶接法で接合することにより、光半導体素子１１を気密に封止する。そして、光ファイバ８が挿通固定された枠状や筒状の金属製のホルダー７を、光半導体素子１１の光入出力端面と光ファイバ８の光入出力端面とが対向し光結合するようにして固定部材３の枠体２外側の一端に溶接することにより、光半導体装置が作製される。
【００４０】
本発明の光半導体装置は、ネジ取付部１ｂで外部電気回路基板にネジ止め固定され、入出力端子４の枠体２外側の線路導体４ａにリード端子やリボン線の一端をロウ付けし、リード端子やリボン線の他端を外部電気回路に接続することにより、光半導体装置内部に収納した光半導体素子１１が外部電気回路に電気的に接続され、光半導体素子１１が高周波信号で作動することとなる。
【００４１】
このような光半導体装置は、外部電気回路から供給される駆動信号によって光半導体素子１１を光励起させ、励起したレーザ光等の光信号を光ファイバ８に入力させるとともに光ファイバ８内を伝送させることによって、または、外部から光ファイバ８を通って伝送してきた光信号を光半導体素子１１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、大容量の情報を高速に伝送できる光電変換装置として機能し、光通信分野等に多く用いられる。
【００４２】
【実施例】
本発明の半導体素子収納用パッケージの実施例を以下に説明する。
【００４３】
図１の本発明のパッケージのサンプルを以下のようにして作成した。Ｃｕの含有率の異なる数種のＣｕ−Ｗ合金（表１参照）からなる縦３０ｍｍ×横１３ｍｍ×高さ１ｍｍの基体１を用意した。
【００４４】
そして、Ｆｅ−Ｎｉ−Ｃｏ合金（平均線膨張係数：９．８×１０−６／℃）からなる縦２１ｍｍ×横１３ｍｍ×高さ７ｍｍで厚さ１ｍｍの枠体２および、縦２１ｍｍ×横１３ｍｍ×高さ１ｍｍで厚さ１ｍｍのシールリング５、Ａｌ２Ｏ３質セラミックス（平均線膨張係数：７．８×１０−６／℃）から成る幅４ｍｍ×高さ３．５ｍｍ×長さ１８ｍｍの入出力端子４を用意し、基体１、枠体２、入出力端子４、シールリング５をＡｇ−Ｃｕロウ（融点７８０℃）で接合し、これらを常温（２５℃）まで均一に冷却することによりパッケージを作成した（サンプルＰ１〜Ｐ３）。
【００４５】
これらのサンプルＰ１〜Ｐ３の基体１底面部の反りの大きさは表１に示すような値であった。なお、表１において、反りの大きさは基体１の貫通穴２ａの側の一端とそれに対向する他端とを結ぶ面（基準面）と載置部１ａとの距離（基体１の上面と基準面との最大距離）を示し、基体１の載置部１ａが基準面からどの程度上側に反っているかを示す。即ち、数値がマイナスであるのは基体１が貫通穴の側の一端とそれに対向する他端とが載置部１ａよりも上側に位置するように反っており、本発明の請求範囲外であることを示す。
【００４６】
【表１】
【００４７】
これらのサンプルＰ１〜Ｐ３を上面が平坦な外部電気回路基板にネジ止めした際の、載置部１ａ中心部の厚み方向の歪みによって発生した変位量を有限要素法による解析によって求めた。これらの評価結果を表２に示す。
【００４８】
【表２】
【００４９】
表２より、基体１の貫通穴２ａの側の一端とそれに対向する他端とが載置部１ａよりも上側に位置するように反っている本発明のサンプルＰ２およびＰ３における基体１の載置部１ａの中心部に発生する変位は、１μｍ以下の値に大幅に低減させることができ、本発明のパッケージが光ファイバ８と光半導体素子１１との光軸ずれを防止するのに有効であることが判った。
【００５０】
本発明は以上の実施の形態の例および実施例に限定されるものでなく、本発明の要旨を逸脱しない範囲内で種々の変更を施すことは何等支障ない。例えば、固定部材３は貫通穴２ａの枠体２外側開口の周囲に一端がロウ付けまたは溶接されてもよく、これにより貫通穴２ａの内面に固定部材３の外周面を嵌着させる必要がなくなるため、貫通穴２ａの内径寸法および固定部材３の外形寸法の精度を比較的粗くすることができ、貫通穴２ａや固定部材３の加工が容易になり作業効率が向上する。
【００５１】
【発明の効果】
本発明の光半導体素子収納用パッケージは、上側主面に光半導体素子が載置される載置部が形成されているとともに四隅部にネジ取付部が形成された四角形状の金属製の基体と、この基体の上側主面の外周部でネジ取付部よりも内側に載置部を囲繞するように接合され、側部に光ファイバを固定するための貫通穴が形成された金属製の枠体と、貫通穴に嵌着されるかまたは貫通穴の枠体外面側の開口の周囲に一端が接合された筒状の光ファイバ固定部材とを具備しており、基体は、貫通穴の側の一端とそれに対向する他端とが載置部よりも下側に位置するように反っていることから、載置部に載置した光半導体素子と光ファイバとを光結合させた後、光半導体素子収納用パッケージを外部電気回路基板にネジ止めしても、基体の載置部が上に凸となるようにして反っているため、基体の枠体内側の部位は外部電気回路基板と接触することがなく、基体の反りを押し広げるような応力の支点は枠体内側の部位には存在しない。即ち、基体が反った状態を維持しながら外部電気回路基板にネジ止めされることとなり、光半導体素子と光ファイバとの光結合効率の劣化を効果的に抑制することができる。
【００５２】
また、ネジ止め部は基体と一体になっているため、ネジ止め部が基体から剥離することなく、枠体との接合部を支点として適度に変形することが可能となる。従って、ネジ止め部が外部回路基板の形状に合わせて適度に変形して、基体の枠体内側の部位に応力を伝えたり、歪みを発生させたりすることなく、光半導体素子収納用パッケージを外部電気回路基板にネジ止めすることが可能となり、光半導体素子の光入出力端面と光ファイバの光入出力端面との間における光信号の授受を正常に維持させ、光結合効率の優れたものとすることができる。
【００５３】
本発明の光半導体装置は、上記本発明の光半導体素子収納用パッケージと、光ファイバ固定部材に挿入され固定された光ファイバと、この光ファイバに光学的に結合するように載置部に載置された光半導体素子と、枠体の上面に接合された蓋体とを具備していることにより、上記本発明の光半導体素子収納用パッケージを用いた光結合効率の優れたものとなる。
【図面の簡単な説明】
【図１】本発明の光半導体素子収納用パッケージについて実施の形態の例を示す平面図である。
【図２】図１の光半導体素子収納用パッケージのＡ−Ａ’線における断面図である。
【図３】従来の光半導体素子収納用パッケージの平面図である。
【図４】図３の光半導体素子収納用パッケージのＢ−Ｂ’線における断面図である。
【符号の説明】
１：基体
１ａ：載置部
１ｂ：ネジ取付部
２：枠体
２ａ：貫通穴
２ｂ：取付部
３：光ファイバ固定部材
４：入出力端子
４ａ：線路導体
６：蓋体
８：光ファイバ
１１：光半導体素子[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, and more particularly to an optical semiconductor device having an improved mounting structure on an external electric circuit board.
[0002]
[Prior art]
FIGS. 3 and 4 show a conventional package for housing an optical semiconductor device (hereinafter, simply referred to as a package) for housing an optical semiconductor device. FIG. 3 is a plan view of the package, and FIG. 4 is a sectional view taken along line BB ′ of FIG. In these figures, 21 is a rectangular base, 22 is a frame, 23 is an optical fiber fixing member (hereinafter also simply referred to as a fixing member), 24 is an input / output terminal, and 26 is a lid. The frame 22 and the lid 26 basically constitute a container for housing the optical semiconductor element 31 in the internal space.
[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, and has a semiconductor laser (LD) ), A mounting portion 21a for mounting and fixing an optical semiconductor element 31 such as a photodiode (PD). Further, a screw mounting portion 21b is provided in which a through hole 21c is formed in an extending portion provided by extending the four corners of the base 21 outward on the same surface. The base 21 is fixed to the external electric circuit board by screwing through the through hole 21c.
[0004]
A frame 22 having a through hole 22a formed on the side thereof is provided upright on the outer peripheral portion of the upper main surface of the base 21 so as to surround the mounting portion 21a. The frame body 22 is made of a metal such as an Fe—Ni—Co alloy or a Cu—W alloy similarly to the base body 21, and is integrally formed with the base body 21, or a base material 21 made of a brazing material such as silver (Ag) braze. The base 21 is erected on the outer peripheral portion of the upper main surface of the base 21 by being brazed through or joined by a welding method such as a seam welding method.
[0005]
A fixing member 23 is attached to the side of the frame 22 by being fitted into the through hole 22a. The fixing member 23 is a cylindrical member for fixing the optical fiber 28 to the side of the frame 22, and is made of a metal such as an Fe—Ni—Co alloy or stainless steel (SUS). A through hole 23a formed in the center axis direction is provided, and an outer peripheral surface of the fixing member 23 is fitted and joined to an inner surface of the through hole 22a of the frame 22 via a brazing material.
[0006]
Further, a mounting portion 22b formed of a cutout portion or a through hole for mounting the input / output terminal 24 is formed on a side portion of the frame body 22 adjacent to the side portion on which the through hole 22a is formed. The mounting portion 22b has an input / output made of ceramics such as an alumina (Al 2 O 3 ) -based sintered body, an aluminum nitride (AlN) -based sintered body, and a mullite (3Al 2 O 3 · 2SiO 2 ) -based sintered body. The terminals 24 are fitted and joined via a brazing material, and a large number of line conductors 24a that conduct between the inside and outside of the frame body 22 are formed.
[0007]
In such a package, a seal ring 25 made of a metal such as an Fe-Ni-Co alloy is joined to the upper surfaces of the frame body 22 and the input / output terminals 24 via a brazing material such as Ag solder. An optical semiconductor element 31 is mounted on the mounting section 21a via a base 30 such as a Peltier element or a circuit board. Each electrode of the optical semiconductor element 31 is connected to a frame of the line conductor 24a via a bonding wire 32. 22 is electrically connected to a portion inside. Then, the optical fiber 28 fixed to the holder 27 is inserted through the fixing member 23, and the holder 27 is welded and fixed to the fixing member 23, so that the light input / output end face of the optical fiber 28 and the light input / output The end face is optically coupled. Thereafter, a lid 26 made of a Fe—Ni—Co alloy or the like is joined to the upper surface of the seal ring 25 by a welding method such as a seam welding method to hermetically seal the optical semiconductor element 31, so that light as a product is obtained. The semiconductor device is completed.
[0008]
In this optical semiconductor device, the base 21 is screwed and fixed to an external electric circuit board (not shown) by passing a screw through the through hole 21c of the screw mounting portion 21b, and the line conductor 24a outside the frame 22 of the input / output terminal 24 is connected to the line conductor 24a. After being electrically connected to the external electric circuit, light is excited by the optical semiconductor element 31 by an electric signal from the external electric circuit, and the light is transmitted to the outside via the optical fiber 28, or the light is transmitted from the outside. An optical signal transmitted through the fiber 28 is received by the optical semiconductor element 31 and converted into an electric signal, whereby the optical semiconductor element 31 can operate as a photoelectric conversion element, and is used for high-speed optical communication and the like.
[0009]
However, in such an optical semiconductor device, when a screw is inserted into the through hole 21c and fixed to the external electric circuit board with a screw, stress is generated in the screw mounting portion 21b due to the tightening of the screw, and the stress is generated by the base 21 or There is a problem in that the package is distorted by being transmitted to the frame 22, and as a result, the optical axis of the optical fiber 28 and the optical semiconductor element 31 are shifted, thereby deteriorating the optical coupling efficiency.
[0010]
In order to solve such a problem, the screw mounting portion 21b is formed separately from the base 21, and is formed of a material having a lower longitudinal elastic modulus than the base 21, for example, Cu, Cu alloy, aluminum (Al), Al alloy, or the like. A configuration in which Ag is brazed to the base 21 has been proposed (for example, see Patent Document 1 below). Accordingly, when the package is screwed and fixed, even if the screw mounting portion 21b is tightened with a screw, the screw mounting portion 21b is mainly deformed and the deformation of the base 21 is suppressed, so that the optical semiconductor element 31 and the optical fiber 28 A decrease in optical coupling efficiency can be suppressed.
[0011]
[Patent Document 1]
JP-A-6-82659
[Problems to be solved by the invention]
However, in the package disclosed in Patent Document 1, even when the screw mounting portion 21b is tightened with a screw at the time of screwing and fixing, the screw mounting portion 21b is mainly deformed and the deformation of the base 21 is suppressed, but the screw mounting portion 21b is deformed. There is a problem that stress is easily concentrated on the joint between the portion 21b and the base 21, and the stress causes peeling at the joint between the screw mounting portion 21b and the base 21 to damage the package.
[0013]
In addition, since the base 21 and the frame 22 have substantially the same average linear expansion coefficient, and the frame 22 is joined to the upper main surface of the base 21, the package was heated and brazed at the time of manufacturing the package. At the time of post-cooling, the frame 22 side is restrained, and the base 21 is easily warped so that the mounting portion 21a is located below the joint portion with the frame 22. Therefore, when the optical semiconductor element 31 is mounted on the package, the optical axis is adjusted with the optical fiber 28, and then the package is mounted on the external electric circuit board, the apex of the warp of the base 21 contacts the external electric circuit board. The stress is applied so as to push the warp of the base 21 from the screw mounting portion 21b with the contact point as a fulcrum, and the base 21 is deformed, and the optical coupling efficiency between the optical semiconductor element 31 and the optical fiber 28 is greatly deteriorated. Had also.
[0014]
Accordingly, the present invention has been completed in view of the above problems, and an object of the present invention is to effectively suppress occurrence of distortion in an optical semiconductor element housing package due to screwing of the optical semiconductor element housing package, and to provide an LD. Optical semiconductor device housing package and optical semiconductor device having excellent optical coupling efficiency by maintaining normal transmission and reception of an optical signal between an optical input / output end face of an optical semiconductor element such as an optical semiconductor device and a PD and an optical input / output end face of an optical fiber. Is to provide.
[0015]
[Means for Solving the Problems]
The optical semiconductor element housing package of the present invention has a square metal base in which a mounting portion on which the optical semiconductor device is mounted is formed on the upper main surface and screw mounting portions are formed at four corners. A metal which is joined to the outer peripheral portion of the upper main surface of the base body inside the screw mounting portion so as to surround the mounting portion, and has a through hole formed on a side portion for fixing an optical fiber. And a cylindrical optical fiber fixing member that is fitted into the through hole or one end of which is joined around an opening of the through hole on the outer surface side of the frame. Is characterized in that one end on the side of the through hole and the other end opposite to the through hole are warped so as to be positioned lower than the mounting portion.
[0016]
In the package for housing an optical semiconductor element of the present invention, one end of the base on the side of the through hole and the other end facing the same are warped so as to be located below the mounting portion. After optically coupling the placed optical semiconductor device and the optical fiber, even if the optical semiconductor device housing package is screwed to the external electric circuit board, the mounting portion of the base is warped so as to be convex upward. Therefore, the portion of the base inside the frame does not come into contact with the external electric circuit board, and the fulcrum of the stress that pushes out the warpage of the base does not exist in the portion inside the frame. That is, the substrate is screwed to the external electric circuit board while maintaining the warped state, so that the deterioration of the optical coupling efficiency between the optical semiconductor element and the optical fiber can be effectively suppressed.
[0017]
In addition, since the screw attachment portion is integrated with the base, the screw attachment portion can be appropriately deformed with the joint portion with the frame serving as a fulcrum without peeling off from the base. Therefore, the screw mounting portion is appropriately deformed according to the shape of the external circuit board, and the optical semiconductor element housing package can be externally transferred without transmitting stress or generating distortion to the portion of the base inside the frame. Screws can be screwed to the electric circuit board, and the transmission and reception of optical signals between the optical input / output end face of the optical semiconductor element and the optical input / output end face of the optical fiber can be maintained normally. can do.
[0018]
The optical semiconductor device of the present invention includes the package for storing an optical semiconductor element of the present invention, an optical fiber inserted and fixed in the optical fiber fixing member, and a mounting portion that is optically coupled to the optical fiber. And a lid joined to the upper surface of the frame.
[0019]
With the above configuration, the optical semiconductor device of the present invention has excellent optical coupling efficiency using the optical semiconductor element housing package of the present invention.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
The package for housing an optical semiconductor element of the present invention will be described in detail below. FIG. 1 is a plan view showing an example of an embodiment of the package of the present invention, and FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. In these figures, 1 is a base, 2 is a frame, 3 is a fixing member, 4 is an input / output terminal, 5 is a seal ring, 6 is a lid, and these base 1, frame 2, input / output terminal 4 and The lid 6 basically constitutes a container for housing the optical semiconductor element 11 therein.
[0021]
The package according to the present invention includes a square metal base 1 having a mounting portion 1a on which an optical semiconductor element 11 is mounted on its upper main surface and screw mounting portions 1b formed at four corners, A metal having an outer peripheral portion of the upper main surface of the base 1 which is joined to the inside of the screw mounting portion 1b so as to surround the mounting portion 1a and which has a through hole 2a for fixing the optical fiber 8 on a side portion. Frame member 2 and a cylindrical optical fiber fixing member 3 which is fitted into the through hole 2a or one end of which is joined to the periphery of the opening of the through hole 2a on the outer surface side of the frame member 2. The base 1 is warped so that one end on the side of the through hole 2a and the other end facing the through hole 2a are located below the mounting portion 1a.
[0022]
The base 1 is preferably warped so as to have a smooth curved surface from the mounting portion 1a to both ends on the side of the through hole 2a with the mounting portion 1a on the upper main surface as a vertex. Accordingly, when the package is screwed to the external electric circuit, only the portion outside the frame 2 is fixed to the surface of the external electric circuit board without deforming or distorting the portion inside the frame 2 of the base 1. It can be appropriately deformed according to the shape.
[0023]
The magnitude of the warpage of the base 1, that is, the distance between the top of the warp of the upper main surface of the base 1 and the plane formed by both ends on the side of the plane through hole 2 a in contact with the entire lower surface of the frame 2 is 1 to The thickness is preferably 50 μm. When the thickness is less than 1 μm, the portion of the base 1 in the inner region of the frame 2 comes into contact with the external electric circuit board, and the base 1 is easily deformed by the distortion of the external electric circuit board, and the optical semiconductor element 11 and the optical fiber 8 Easily shifts in the optical axis. If the thickness exceeds 50 μm, it becomes difficult to fix the optical semiconductor element 11 to the mounting portion 1a, and when the package is screwed to the external electric circuit board, a portion of the base 1 outside the frame 2 is greatly deformed, The stress due to this deformation is transmitted to the mounting portion 1a, and the optical axis of the optical semiconductor element 11 and the optical fiber 8 is easily shifted.
[0024]
The base 1 is made of a metal material such as an Fe-Ni-Co alloy or a Cu-W alloy, and is formed into a predetermined shape by subjecting the ingot to a conventionally known metal working method such as rolling or punching. At four corners of the base 1, a screw mounting portion 1b extending outward is formed, and the screw mounting portion 1b is formed with a through hole 1c for screw insertion.
[0025]
The base 1 is formed by pressing and deforming a metal material on a flat plate with a mold or the like, or by molding by a method such as metal injection molding, so that one end on the side of the through hole 2a and the other end facing the through hole 2a. It can be warped so as to be located below the mounting portion 1a. Alternatively, by setting the material of the base 1 to have a lower elastic modulus than that of the frame 2, when the base 1 contracts greatly during cooling after the frame 2, the input / output terminals 4 and the base 1 are joined by heating, the frame 1 The body 2 and the input / output terminals 4 are hardly deformed, whereas the base 1 is easily deformed, so that the base 2 can be warped so as to project upward.
[0026]
The substrate 1 is preferably a Cu-W alloy containing 15% to 20% of Cu. Thereby, the base 1 can be appropriately softened and easily bent so that one end on the side of the through hole 2a and the other end facing the through hole 2a are located below the mounting portion 1a. In addition, the screw attachment portion 1b can be easily deformed appropriately with the joint between the base 1 and the frame 2 as a fulcrum, so that transmission of stress to the mounting portion 1a can be suppressed. Furthermore, since such a base 1 is excellent in heat dissipation, the optical semiconductor element 11 can be driven more stably.
[0027]
Since the base 1 is warped so that one end on the side of the through hole 2a and the other end opposite to the through hole 2a are located below the mounting portion 1a, the optical semiconductor element 11 mounted on the mounting portion 1a is warped. Even after the package is screwed to the external electric circuit board after optically coupling the optical fiber 8 and the optical fiber 8, the mounting portion 1a of the base 1 is warped so as to be convex upward. The portion inside the body 2 does not come into contact with the external electric circuit board, and the fulcrum of the stress that pushes out the warpage of the base 1 does not exist in the portion inside the frame 2. That is, the base 1 is screwed to the external electric circuit board while maintaining the warped state, so that the deterioration of the optical coupling efficiency between the optical semiconductor element 11 and the optical fiber 8 can be effectively suppressed.
[0028]
Further, since the screw mounting portion 1b is integrated with the base 1, the screw mounting portion 1b can be appropriately deformed with the joint with the frame 2 as a fulcrum without peeling off from the base 1. Accordingly, the screw mounting portion 1b is appropriately deformed according to the shape of the external circuit board, and does not transmit stress to the portion inside the frame 2 of the base 1 or generate distortion, and the package is connected to the external electric circuit. Screws can be screwed to the substrate, and transmission and reception of optical signals between the optical input / output end face of the optical semiconductor element 11 and the optical input / output end face of the optical fiber 8 can be normally maintained. can do.
[0029]
As shown in FIG. 1, the shape of the screw mounting portion 1 b in plan view may be such that two opposing sides of the base 1 extend outside the frame 2, respectively, It may be extended so as to protrude outside the frame body 2, and one through hole 1 c may be formed in each extending portion.
[0030]
An optical semiconductor element 11 such as an LD or PD is mounted and fixed on the mounting portion 1a on the upper surface of the base 1. The base 1 also serves as a heat radiating plate for radiating heat generated when the optical semiconductor element 11 operates to the outside. The optical semiconductor element 11 is mounted on the mounting portion 1a while being mounted on a base 10 such as a Peltier element or a circuit board in order to efficiently radiate heat generated during operation to the outside through the base 1. It may be fixed.
[0031]
In addition, on the surface of the base 1, a Ni layer having a thickness of 0.5 to 9 μm or a gold layer having a thickness of 0.5 to 5 μm ( It is preferable that a metal layer composed of an Au) layer be applied by plating or the like.
[0032]
The frame body 2 is a frame-like body having a square shape in plan view, and is joined to the outer peripheral portion of the upper main surface of the base 1 so as to surround the mounting portion 1a inside the screw mounting portion 1b and to have a through hole in the side portion. 2a and a mounting portion 2b are formed. The through hole 2 a supports the fixing member 3, and the mounting portion 2 b supports the input / output terminal 4. Such a frame 2 is made of an Fe—Ni—Co alloy, a Cu—W alloy, or the like, like the base 1, and is brazed to the base 1 via a brazing material such as Ag brazing, or a seam welding method. By being welded by such a welding method as above, the base 1 is erected on the outer peripheral portion of the upper main surface.
[0033]
The frame 2 together with the base 1 forms a space for accommodating the optical semiconductor element 11 therein, and is fitted into the through hole 2a on the side thereof or the opening of the through hole 2a outside the frame 2 is formed. The optical fiber 8 is supported and fixed via a cylindrical fixing member 3 having one end joined to the periphery.
[0034]
The fixing member 3 is a cylindrical member such as a cylindrical member for fixing the optical fiber 8 to a side portion of the frame 2, and is made of a metal such as an Fe-Ni-Co alloy or stainless steel. The fixing member 3 is provided with a through hole 3a for inserting the optical fiber 8 in the center axis direction, and the outer peripheral surface is fitted to the inner surface of the through hole 2a on the side of the frame 2 via a brazing material. One end is joined to the periphery of the opening of the through hole 2a on the outside of the frame body 2 via a brazing material, thereby being fixed to the side of the frame body 2.
[0035]
The input / output terminal 4 has a rectangular pillar-shaped standing wall portion laminated on the upper surface of a rectangular flat plate portion, and is made of a dielectric such as Al 2 O 3 ceramics, AlN ceramics, 3Al 2 O 3 .2SiO 2 ceramics. Member. The input / output terminal 4 is fitted into the mounting portion 2a of the frame 2, and the gap between the input / output terminal 4 and the mounting portion 3a is filled with molten brazing material such as Ag braze by capillary action. Is fitted and joined. On the upper surface of the flat plate portion of the input / output terminal 4, a line conductor 4 a made of a metallized layer of W, molybdenum (Mo) or the like, which conducts inside and outside of the frame 2, is formed. And has a function as a conductive path for electrically connecting the inside and outside of the frame 2.
[0036]
The screw mounting portion 1b is preferably provided on the side of the frame 2 where the through hole 2a to which the optical fiber 8 is fixed is formed, and on the side of the frame 2 opposed to this side. Thus, it is possible to suppress the stress generated when the package is fixed to the external electric circuit board by screwing from being applied to the side of the frame 2 to which the optical fiber 8 is fixed. That is, while the bending stress of the base 1 is most likely to be largest in a portion located between the two screw mounting portions 1b extending in opposite directions, the two screws on the same side of the frame 2 are opposite to each other. The bending stress of the substrate 1 is small in the portion located between the mounting portions 1b, and the position of the optical fiber 8 is fixed by fixing the optical fiber 8 on the side of the frame 2 corresponding to the portion having a small bending stress. Deviation can be effectively suppressed.
[0037]
Further, the shape of the through-hole 1c in a plan view does not need to be circular as shown in FIG. 1, but may be square or semicircular.
[0038]
The optical semiconductor device of the present invention includes a package having the above-described configuration, an optical fiber 8 inserted and fixed in the fixing member 3, and an optical fiber mounted on the mounting portion 1 a so as to be optically coupled to the optical fiber 8. The semiconductor device includes a semiconductor element and a lid joined to an upper surface of the frame.
[0039]
Such an optical semiconductor device is manufactured as follows. First, after the optical semiconductor element 11 is mounted and fixed on the mounting part 1a via the base 10 such as a Peltier element or a circuit board in the package having the above configuration, the electrodes of the optical semiconductor element 11 and the side parts of the frame 2 are fixed. Alternatively, the input / output terminals 4 functioning as conductive paths inside and outside the package provided on the base 1 are electrically connected to the line conductors 4 a inside the frame 2 by bonding wires 12 and bonded to the upper portion of the frame 2. The optical semiconductor element 11 is attached to the upper surface of the sealed ring 5 by joining a lid 6 made of metal such as Fe-Ni-Co alloy, ceramics, resin or the like by a welding method such as a brazing method or a seam welding method. Seal hermetically. Then, a frame-shaped or cylindrical metal holder 7 into which the optical fiber 8 is inserted and fixed is set so that the optical input / output end face of the optical semiconductor element 11 and the optical input / output end face of the optical fiber 8 face and optically couple. The optical semiconductor device is manufactured by welding the fixing member 3 to one end of the fixing member 3 outside the frame 2.
[0040]
The optical semiconductor device of the present invention is screwed and fixed to an external electric circuit board by a screw mounting portion 1b, and one end of a lead terminal or a ribbon wire is brazed to a line conductor 4a outside the frame 2 of the input / output terminal 4, and a lead is formed. By connecting the terminal or the other end of the ribbon wire to an external electric circuit, the optical semiconductor element 11 housed inside the optical semiconductor device is electrically connected to the external electric circuit, and the optical semiconductor element 11 operates with a high-frequency signal. It becomes.
[0041]
In such an optical semiconductor device, the optical semiconductor element 11 is optically excited by a drive signal supplied from an external electric circuit, and an optical signal such as an excited laser beam is input to the optical fiber 8 and transmitted through the optical fiber 8. Or by allowing the optical semiconductor element 11 to receive an optical signal transmitted from the outside through the optical fiber 8 and converting the optical signal into an electric signal, thereby transmitting a large amount of information at a high speed. It functions and is often used in the optical communication field and the like.
[0042]
【Example】
Embodiments of the package for housing a semiconductor element of the present invention will be described below.
[0043]
A sample of the package of the present invention shown in FIG. 1 was prepared as follows. A base 1 having a length of 30 mm, a width of 13 mm, and a height of 1 mm made of several kinds of Cu-W alloys having different Cu contents (see Table 1) was prepared.
[0044]
Then, a frame 2 made of an Fe—Ni—Co alloy (average coefficient of linear expansion: 9.8 × 10 −6 / ° C.) having a length of 21 mm × width of 13 mm × height of 7 mm and a thickness of 1 mm, and a length of 21 mm × width of 13 mm × Seal ring 5 having a height of 1 mm and a thickness of 1 mm, made of Al 2 O 3 ceramics (average coefficient of linear expansion: 7.8 × 10 −6 / ° C.) 4 mm wide × 3.5 mm high × 18 mm long The input / output terminals 4 are prepared, and the base 1, the frame 2, the input / output terminals 4, and the seal ring 5 are joined with an Ag-Cu solder (melting point: 780 ° C), and these are uniformly cooled to room temperature (25 ° C). (Samples P1 to P3).
[0045]
The magnitude of the warpage of the bottom surface of the base 1 of each of the samples P1 to P3 was as shown in Table 1. In Table 1, the magnitude of the warpage is determined by the distance between the surface (reference surface) connecting one end of the base 1 on the side of the through hole 2a and the other end opposite thereto and the mounting portion 1a (the upper surface of the base 1 and the reference). (The maximum distance from the surface), and shows how much the mounting portion 1a of the base 1 is warped upward from the reference surface. That is, the reason why the numerical value is negative is that the base 1 is warped so that one end on the side of the through hole and the other end opposite to the through hole are located above the mounting portion 1a, which is outside the scope of the present invention. It indicates that.
[0046]
[Table 1]
[0047]
When these samples P1 to P3 were screwed to an external electric circuit board having a flat upper surface, the displacement generated by the strain in the thickness direction at the center of the mounting portion 1a was obtained by analysis by the finite element method. Table 2 shows the evaluation results.
[0048]
[Table 2]
[0049]
From Table 2, the placement of the base 1 in the samples P2 and P3 of the present invention in which one end of the base 1 on the side of the through hole 2a and the other end opposite to the through-hole 2b are warped so as to be located above the placement section 1a. The displacement occurring at the center of the portion 1a can be greatly reduced to a value of 1 μm or less, and the package of the present invention is effective for preventing the optical axis 8 from being shifted from the optical fiber 8 to the optical semiconductor element 11. It turns out.
[0050]
The present invention is not limited to the above-described embodiments and examples, and various changes may be made without departing from the scope of the present invention. For example, one end of the fixing member 3 may be brazed or welded around the outer opening of the frame 2 of the through hole 2a, so that it is not necessary to fit the outer peripheral surface of the fixing member 3 to the inner surface of the through hole 2a. Therefore, the accuracy of the inner diameter of the through hole 2a and the outer dimension of the fixing member 3 can be made relatively coarse, and the processing of the through hole 2a and the fixing member 3 is facilitated, thereby improving the working efficiency.
[0051]
【The invention's effect】
The optical semiconductor element housing package of the present invention has a square metal base in which a mounting portion on which the optical semiconductor device is mounted is formed on the upper main surface and screw mounting portions are formed at four corners. A metal frame body which is joined to the outer peripheral portion of the upper main surface of the base body so as to surround the mounting portion inside the screw mounting portion and has a through hole formed on a side portion for fixing an optical fiber; And a cylindrical optical fiber fixing member one end of which is fitted into the through hole or joined to the periphery of the opening of the through hole on the outer surface side of the frame, and the base is provided on the side of the through hole. Since the one end and the other end opposite to it are warped so as to be located below the mounting portion, the optical semiconductor device mounted on the mounting portion and the optical fiber Even if the element storage package is screwed to the external electric circuit board, the mounting portion of the base Therefore, the portion of the base inside the frame does not come into contact with the external electric circuit board, and the fulcrum of the stress that pushes out the warp of the base does not exist in the inside of the frame. . That is, the substrate is screwed to the external electric circuit board while maintaining the warped state, so that the deterioration of the optical coupling efficiency between the optical semiconductor element and the optical fiber can be effectively suppressed.
[0052]
Further, since the screwed portion is integrated with the base, the screwed portion can be appropriately deformed with the joint with the frame serving as a fulcrum without peeling off from the base. Therefore, the screwing portion is appropriately deformed according to the shape of the external circuit board, and the optical semiconductor element housing package can be externally transferred without transmitting stress or generating distortion to the portion of the base inside the frame. Screws can be screwed to the electric circuit board, and the transmission and reception of optical signals between the optical input / output end face of the optical semiconductor element and the optical input / output end face of the optical fiber can be maintained normally. can do.
[0053]
The optical semiconductor device of the present invention includes the optical semiconductor element storage package of the present invention, an optical fiber inserted and fixed in the optical fiber fixing member, and a mounting portion mounted on the mounting portion so as to be optically coupled to the optical fiber. By providing the placed optical semiconductor element and the lid joined to the upper surface of the frame, the optical coupling efficiency using the optical semiconductor element housing package of the present invention is excellent.
[Brief description of the drawings]
FIG. 1 is a plan view showing an example of an embodiment of an optical semiconductor element housing package of the present invention.
FIG. 2 is a cross-sectional view taken along line AA ′ of the optical semiconductor element housing package of FIG.
FIG. 3 is a plan view of a conventional package for housing an optical semiconductor element.
4 is a cross-sectional view of the package for housing an optical semiconductor element of FIG. 3 taken along line BB ′.
[Explanation of symbols]
1: base 1a: mounting portion 1b: screw mounting portion 2: frame 2a: through hole 2b: mounting portion 3: optical fiber fixing member 4: input / output terminal 4a: line conductor 6: lid 8, optical fiber 11: Optical semiconductor device
