JP3935085B2

JP3935085B2 - Semiconductor element storage package and semiconductor device

Info

Publication number: JP3935085B2
Application number: JP2003035697A
Authority: JP
Inventors: 利弘橋本; 寛司久間
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2003-02-13
Filing date: 2003-02-13
Publication date: 2007-06-20
Anticipated expiration: 2023-02-13
Also published as: JP2004247511A

Description

【０００１】
【発明の属する技術分野】
本発明は、光通信分野やマイクロ波通信、ミリ波通信等の分野で用いられる、高い周波数帯域で作動する各種半導体素子を収納する半導体素子収納用パッケージおよび半導体装置に関する。
【０００２】
【従来の技術】
従来の光通信分野やマイクロ波通信、ミリ波通信等の分野で使用される、高周波数信号により作動する各種半導体素子を収容する半導体素子収納用パッケージ（以下、パッケージともいう）を図５に示す。図５に示すように、パッケージ101は一般に、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る基体102を有する。この基体102は、その上面にＬＤ（半導体レーザ）、ＰＤ（フォトダイオード）、ＩＣ、ＬＳＩ等の半導体素子105が載置用基台107を介して載置される載置部102ａを有する。そして、パッケージ101は、基体102と、鉄−ニッケル−コバルト合金や銅−タングステン合金等の金属から成り、載置部102ａを取り囲むように基体102の上面に接合された枠体103とで主に構成されている。この枠体103は、基体102の上面に銀ろう等のろう材を介して接合されている。
【０００３】
枠体103は、その側部に設けられた貫通孔108に、半導体素子105と外部電気回路とを電気的に接続する絶縁端子である同軸コネクタ104が嵌着接合されている。この同軸コネクタ104は、鉄−ニッケル−コバルト合金等の金属から成る筒状の外周導体104ａと、絶縁体104ｂと、中心導体104ｃとから成る。絶縁体104ｂとしては、ホウ珪酸ガラス等が外周導体104ａの内部に充填されて成る。また、中心導体104ｃは、絶縁体104ｂの中心軸部分に挿着され、パッケージ101の内外を導通させる機能を有する。さらに、外周導体104ａは、枠体103の側部に設けられた貫通孔108の内周面に金−錫合金半田等のろう材106で固定される。そして、同軸コネクタ104は、外部電気回路と半導体素子105とを電気的に接続する機能を有するとともにパッケージ101内部を気密に塞ぐ機能を有する。
【０００４】
なお、枠体103の貫通孔108は、枠体103の外面側に大径部108ａおよび内面側に大径部108ａと同軸で連なる小径部108ｂを有し、大径部108ａの内周面に、外周導体104ａの外周面がろう材106を介して接合されている。また、貫通孔108の内周面は、外周導体104ａの外周面とのろう付け性を良好とするために、その全面にニッケルや金等の金属から成るめっき金属層109が被着されている。
【０００５】
また、同軸コネクタ104と半導体素子105との電気的接続は、中心導体104ｃの枠体103内側に突出した一端と、載置部102ａ上に載置用基台107を載置してこの上に半導体素子105と回路基板107ａとを載置し、中心導体104ｃと回路基板107ａ表面に形成した配線導体107ｂとを金−錫合金半田等の低融点ろう材でろう付けし、配線導体107ｂと半導体素子105とをボンディングワイヤ等の導電性接続部材110を介して接続することにより行なわれる。または、載置部102ａに半導体素子105を直接載置固定し、中心導体104ｃと半導体素子105とを導電性接続部材110で接続することにより行なわれる。
【０００６】
【特許文献１】
特開2002−94167号公報
【０００７】
【発明が解決しようとする課題】
しかしながら、上記従来のパッケージ101においては、枠体103の側部に形成された貫通孔108に同軸コネクタ104の外周導体104ａを半田等のろう材106によりろう付けする工程において、ろう材106がめっき金属層109表面を濡れ広がって貫通孔108の大径部108ａから小径部108ｂまで流れ込み易くなり、その場合、同軸コネクタ104の中心導体104ｃと小径部104ｃとの距離が変化して所定のエアギャップａの確保ができなくなるとともに、中心導体104ｃに対する接地性が不安定となり、良好な高周波特性が得られないという問題点を有していた。
【０００８】
また、ろう材106が貫通孔108の大径部108ａから小径部108ｂまで流れ込むのを防ぐために、ろう材106の量を少なくすると、同軸コネクタ104の外周導体104ａの外周面の全面にろう材106が付着しにくくなり、外周導体104ａの接地性が劣化して良好な高周波特性が得られなくなり、またパッケージの気密が不十分になるという問題点を有していた。
【０００９】
したがって、本発明は上記従来の技術の問題点に鑑み完成されたものであり、その目的は、同軸コネクタにおいて良好な高周波特性が得られるとともに半導体素子を気密に封止して収納することができるパッケージおよび半導体装置を提供することにある。
【００１０】
【課題を解決するための手段】
本発明の半導体素子収納用パッケージは、上面に半導体素子が載置される載置部を有する基体と、該基体の前記上面に前記載置部を取り囲むように取着され、側部に外面から内面まで貫通した、前記外面側に大径部および前記内面側に前記大径部と同軸で連なる小径部を有する貫通孔が形成されているとともに表面にめっき金属層が形成された枠体と、外周導体およびその中心軸に設置された中心導体ならびにその間に介在させた絶縁体から成り、前記外周導体の外周面が前記貫通孔の前記大径部の内周面にろう材を介して接合され、かつ前記中心導体が前記半導体素子に電気的に接続される同軸コネクタとを具備した半導体素子収納用パッケージにおいて、前記貫通孔は、前記大径部の内周面のうちで前記小径部側の端部を除く部位に前記めっき金属層が形成されており、前記端部から前記大径部と前記小径部との間の段差を経て該段差側の前記小径部の端までの部位が前記めっき金属層の非形成部とされていることを特徴とする。
【００１１】
本発明の半導体素子収納用パッケージは、貫通孔は、大径部の内周面のうちで小径部側の端部を除く部位にめっき金属層が形成されており、端部から大径部と小径部との間の段差を経て段差側の小径部の端までの部位がめっき金属層の非形成部とされていることから、枠体の貫通孔に同軸コネクタの外周導体をろう付けする際に、ろう材がめっき金属層の表面を濡れ広がって貫通孔の大径部から小径部まで流れ込むのを、大径部の内周面の小径部側の端部で効果的に防ぐことができる。その結果、同軸コネクタの中心導体と小径部との間のエアギャップを均一とすることができ、中心導体に対する接地性（接地電位部の同軸性）が確保されて、良好な高周波特性が得られる。
【００１２】
また、ろう材が貫通孔の大径部から小径部まで流れ込むのを防ぐためにその量を少なくする必要がないため、同軸コネクタの外周導体の外周面の全面のほとんどにろう材が付着するため、外周導体の接地性が良好になり良好な高周波特性が得られるとともに、十分な気密性が得られる。
【００１３】
さらに、ろう材は貫通孔の大径部と小径部との間の段差にも流れ込まないので、同軸コネクタを貫通孔の上記段差に隙間なく当接させて嵌着でき、高い位置精度で同軸コネクタを枠体に設置することができる。また、ろう材は貫通孔の内周面の大径部の小径部側の端部付近において裾野状の傾斜したメニスカスを形成するため、同軸コネクタの接合強度が向上することとなる。
【００１４】
本発明の半導体装置は、本発明の半導体素子収納用パッケージと、前記載置部に載置固定されるとともに前記同軸コネクタの前記中心導体に電気的に接続された半導体素子と、前記枠体の上面に取着された蓋体とを具備していることを特徴とする。
【００１５】
本発明の半導体装置は、上記の構成により、良好な高周波特性および十分な気密性が得られる、高性能で高信頼性のものとなる。
【００１６】
【発明の実施の形態】
本発明の半導体素子収納用パッケージを以下に詳細に説明する。図１は、本発明のパッケージの実施の形態の一例を示す断面図であり、図１において、２は基体、３は枠体、４は同軸コネクタであり、主にこれらで本発明のパッケージ１が構成される。また、５は半導体素子、６はろう材、７は載置用基台、７ａは回路基板、７ｂは配線導体、８は貫通孔、９はめっき金属層、10はボンディングワイヤである。
【００１７】
なお、図１では、半導体素子５が載置部２ａに載置用基台７を介して載置されているが、半導体素子５が載置部２ａに直接載置されていてもよい。
【００１８】
本発明のパッケージは、上面に半導体素子５が載置される載置部２ａを有する基体２と、基体２の上面に載置部２ａを取り囲むように取着され、側部に外面から内面まで貫通した、外面側に大径部８ａおよび内面側に大径部８ａと同軸で連なる小径部８ｂを有する貫通孔８が形成されているとともに表面にめっき金属層９が形成された枠体３と、外周導体４ａおよびその中心軸に設置された中心導体４ｃならびにその間に介在させた絶縁体４ｂから成り、外周導体４ａの外周面が貫通孔８の大径部８ａの内周面にろう材６を介して接合され、かつ中心導体４ｃが半導体素子５に電気的に接続される同軸コネクタ４とを具備し、貫通孔８は、大径部８ａの内周面のうちで小径部８ｂ側の端部を除く部位にめっき金属層９が形成されており、その端部から大径部８ａと小径部８ｂとの間の段差Ｔを経て段差Ｔ側の小径部８ｂの端までの部位がめっき金属層９の非形成部とされている。
【００１９】
本発明における基体２は、半導体素子５を支持するための支持部材および半導体素子５が発生する熱を放散するための放熱板としての機能を有し、その上面の中央部に半導体素子５が載置用基台７を介して載置される載置部２ａを有している。この載置部２ａに載置用基台７が錫−鉛半田等の低融点ろう材を介して接着され、半導体素子５の熱が載置用基台７および低融点ろう材を介して外部に効率良く放散され、半導体素子５の作動性が良好なものとなる。
【００２０】
この基体２は、鉄−ニッケル−コバルト合金や銅−タングステン合金等の金属から成り、そのインゴットに圧延加工や打ち抜き加工等の従来周知の金属加工を施すことによって長方形状に製作される。また、その表面には耐蝕性に優れるとともにろう材６との濡れ性に優れる金属、具体的には厚さ0.5〜９μｍのニッケル層と0.5〜９μｍの金層とをめっき法により順次被着させておくのがよく、基体２が酸化腐食するのを有効に防止できるとともに、基体２上面に載置用基台７をろう材を介して強固に接合することができる。
【００２１】
載置用基台７はシリコン（Ｓｉ）や銅−タングステン合金等の熱伝導性の高い金属から成り、その上面には、アルミナ（Ａｌ_２Ｏ_３）質焼結体（アルミナセラミックス）等のセラミックスから成り、上面に伝送線路としてのメタライズ層から成る配線導体７ｂが形成されたインピーダンス整合等用の回路基板７ａが接合される。配線導体７ｂは、同軸コネクタ４の中心導体４ｃのインピーダンスと同じになるように形成されたマイクロストリップ線路であり、半導体素子５にボンディングワイヤ10を介して、また、中心導体４ｃとは金−錫合金半田等の低融点ろう材を介して接続され、同軸コネクタ４の中心導体４ｃと半導体素子５とを電気的に接続する機能を有する。
【００２２】
また、基体２の上面には、載置部２ａを取り囲んで枠体３が銀ろう等のろう材を介して接合されている。枠体３は、その側部に外面から内面まで貫通する貫通孔８を有しており、この貫通孔８には同軸コネクタ４が嵌着接合されている。この枠体３は、鉄−ニッケル−コバルト合金や銅−タングステン合金等の金属から成り、そのインゴットに圧延加工や打ち抜き加工等の従来周知の金属加工を施すことによって所定形状に製作される。または、基体２と一体的に形成されていてもよい。また、その表面には耐蝕性に優れるとともにろう材との濡れ性に優れる金属、具体的には厚さ0.5〜９μｍのニッケル層と0.5〜９μｍの金層とをめっき法により順次被着させて成るめっき金属層９が形成されており、これにより、枠体３が酸化腐食するのを有効に防止できるとともに、貫通孔８の内周面に同軸コネクタ４の外周導体４ａを強固に接合することができる。
【００２３】
また、貫通孔８に嵌着された同軸コネクタ４は、半導体素子５と外部電気回路とを電気的に接続する機能を有するとともにパッケージ１の内部を気密に塞ぐ機能を有する。同軸コネクタ４の外周導体４ａは、金属から成る筒状体であり、接地部としての機能を有し、その外周面が貫通孔８の内周面に金−錫合金半田等のろう材６でろう付けされている。同軸コネクタ４の絶縁体４ｂは、ホウ珪酸ガラス等の絶縁物から成り、外周導体４ａと中心導体４ｃとを絶縁する機能を有する。同軸コネクタ４の中心導体４ｃは、絶縁体４ｂの中心軸部分に挿着され、半導体素子５と外部電気回路とを電気的に接続する機能を有する。
【００２４】
外周導体４ａおよび中心導体４ｃは、鉄−ニッケル−コバルト合金や銅−タングステン合金等の金属から成り、そのインゴットに圧延加工や打ち抜き加工等の従来周知の金属加工を施すことによって筒状および棒状に形成される。また、その表面には耐蝕性に優れるとともにろう材６との濡れ性に優れる金属、具体的には厚さ0.5〜９μｍのニッケル層と0.5〜９μｍの金層とをめっき法により順次被着させておくのがよく、外周導体４ａおよび中心導体４ｃが酸化腐食するのを有効に防止できるとともに、外周導体４ａの外周面と貫通孔８の内周面、中心導体４ｃと外部電気回路、および中心導体４ｃと回路基板７ａの配線導体７ｂとを強固に接合することができる。
【００２５】
なお、同軸コネクタ４は、高周波信号が伝送される中心導体４ｃと外周導体４ａとが、信号伝送時のインピーダンス整合が可能な同軸構造を構成しているので、伝送される高周波信号の周波数が高くなっても、中心導体４ｃにインピーダンスの整合が困難となる部位が出現することはない。
【００２６】
そして、本発明のパッケージ１においては、貫通孔８は、大径部８ａの内周面のうちで小径部８ｂ側の端部を除く部位にめっき金属層９が形成されており、その端部から大径部８ａと小径部８ｂとの間の段差Ｔを経て段差Ｔ側の小径部８ｂの端までの部位がめっき金属層９の非形成部とされている。これにより、枠体３の貫通孔８に同軸コネクタ４の外周導体４ａをろう付けする際に、ろう材６がめっき金属層９の表面を濡れ広がって貫通孔８の大径部８ａから小径部８ｂまで流れ込むのを、大径部８ａの内周面の小径部８ｂ側の端部で効果的に防ぐことができる。その結果、同軸コネクタ４の中心導体４ｃと小径部８ｂとの間のエアギャップＡを均一とすることができ、中心導体４ｃに対する接地性（接地電位部の同軸性）が確保されて、良好な高周波特性が得られる。
【００２７】
また、ろう材６が貫通孔８の大径部８ａから小径部８ｂまで流れ込むのを防ぐためにその量を少なくする必要がないため、同軸コネクタ４の外周導体４ａの外周面の全面のほとんどにろう材６が付着するため、外周導体４ａの接地性が良好になり良好な高周波特性が得られるとともに、十分な気密性が得られる。
【００２８】
さらに、ろう材６は貫通孔８の大径部８ａと小径部８ｂとの間の段差Ｔにも流れ込まないので、同軸コネクタ４を貫通孔８の段差Ｔに隙間なく当接させて嵌着でき、高い位置精度で同軸コネクタ４を枠体３に設置することができる。また、ろう材６は貫通孔８の内周面の大径部８ａの小径部８ｂ側の端部付近において裾野状の傾斜したメニスカスを形成するため、同軸コネクタ４の接合強度が向上することとなる。
【００２９】
上記のめっき金属層９の非形成部は以下のような方法により設けられる。まず、枠体３となる鉄−ニッケル−コバルト合金や銅−タングステン合金等の母材を準備し、この母材に従来周知の圧延加工や打抜き加工を施すことにより枠体３を製作する。次に、枠体３の側部に貫通孔８を、従来周知の打抜き加工や切削加工法を用いて、枠体３の外面側が同軸コネクタ４の外周導体４ａの直径より大きな径を有する大径部８ａ、内面側が同軸コネクタ４の外周導体４ａの直径より小さな径を有する小径部８ｂとなるように穿孔する。
【００３０】
次に、枠体３の表面全体に厚さ0.5〜９μｍのニッケル層と厚さ0.5〜９μｍの金層とをめっき法により順次被着し、しかる後、大径部８ａと小径部８ｂとの間の段差Ｔおよび大径部８ａの内周面で小径部８ｂ側の端部（以下、端部Ｔ１という）を、先端にダイヤモンド等の研削材を固着したリューターを用いて機械的に研磨してめっき金属層９を除去し、段差Ｔおよび端部Ｔ１をめっき金属層９の非形成部とする。
【００３１】
または、枠体３の表面全体にめっき金属層９を被着する前に、段差Ｔおよび端部Ｔ１を、めっき液への耐薬品性（耐アルカリ性や耐酸性）を持つビニールテープやオーバーコートレジン（保護樹脂層）などで予めマスクしておき、このマスクをめっき金属層９を被着した後に取り除くことにより、段差Ｔおよび端部Ｔ１をめっき金属層９の非形成部としてもよい。
【００３２】
本発明において、上記端部Ｔ１の幅（同軸コネクタ４の軸方向の幅）は、0.10〜0.50ｍｍがよい。0.10ｍｍ未満では、ろう材６が段差Ｔへ入り込み易くなる。0.50ｍｍを超えると、同軸コネクタ４の外周導体４ａの接合強度が低下するとともに、外周導体４ａの外周面で枠体３に接地されない部位が大きくなり、外周導体４ａの接地性が不安定になり易い。
【００３３】
また本発明において、図２〜図４に示すように、めっき金属層９の非形成部の端部Ｔ１付近に溝11を全周にわたって形成してもよい。
【００３４】
図２は、端部Ｔ１にめっき金属層９の端に隣接して溝11を形成したものであり、この場合ろう材６が段差Ｔへ向かって広がろうとしても溝11で効果的に阻止することができる。
【００３５】
図３は、端部Ｔ１にめっき金属層９の端が内面の途中（底面の途中）まで形成された溝11を設けたものであり、この場合ろう材６が段差Ｔへ向かって広がろうとしても溝11でより効果的に阻止することができる。すなわち、ろう材６は溝11のめっき金属層９によって溝11内へは容易に誘い込まれるものの、溝11から段差Ｔ側の狭い隙間へ入り込むのは容易ではないことによる。
【００３６】
図４は、端部Ｔ１にめっき金属層９が内面の全面に形成された溝11で、めっき金属層９の端が開口に達している溝11を設けたものであり、この場合ろう材６が段差Ｔへ向かって広がろうとしても溝11で効果的に阻止することができる。この場合、ろう材６は溝11のめっき金属層９によって溝11内へ容易に誘い込まれて溜まり、溝11で阻止されることとなる。
【００３７】
また、同軸コネクタ４の貫通孔８への嵌着は、以下のような方法により行なわれる。まず、内径が同軸コネクタ４の外周導体４ａの径よりも大きく外径が貫通孔８の大径部８ａの径よりも小さい、厚みが0.2〜0.5ｍｍの筒状でフラックス入りの高温（高融点280〜290℃）のＰｂ−Ｓｎ半田（Ｐｂ：Ｓｎ＝９：１）を準備する。この筒状のＰｂ−Ｓｎ半田の長さは、外周導体４ａの長さと略同じとする。
【００３８】
なお、このような筒状の半田は、円柱状の半田を所定の長さに切断した後、打抜き加工により貫通孔を形成することにより製作される。
【００３９】
次に、筒状の半田に挿入した同軸コネクタ４を枠体３の貫通孔８の大径部８ａに挿入し、その状態で枠体３を炉に入れて、フラックスおよび枠体３の酸化を防ぐためにＮ_２雰囲中で、ステンレススチール（ＳＵＳ）製のヒーターブロックを熱源とし、１〜３分程度300〜400℃の温度に加熱する。これにより、半田を溶融して、同軸コネクタ４の外周導体４ａの外周面が貫通孔８の大径部８ａの内周面に接合される。この場合、Ｎ_２が充填された連続炉で、ピーク温度を300〜400℃とし、１〜３分程度保持することで半田を溶融させてもよい。
【００４０】
また、枠体３の上面には、鉄−ニッケル−コバルト合金等の金属やアルミナセラミックス等の絶縁材料から成る蓋体（図示せず）が接合され、これにより基体２、枠体３および蓋体から成る容器の内部に半導体素子５が気密に収納される。蓋体の枠体３上面への接合は、シーム溶接法、ＹＡＧレーザ溶接法等の溶接法、金−錫合金半田等の低融点ろう材によるろう付けにより行なわれる。
【００４１】
かくして、本発明のパッケージ１は、基体２の載置部２ａに半導体素子５を載置固定するとともに、半導体素子５の各電極をボンディングワイヤ10等を介して同軸コネクタ４の中心導体４ｃに電気的に接続し、次に、枠体３の上面に蓋体を取着し、基体２と枠体３と蓋体とから成る容器の内部に半導体素子５を気密に収納することによって半導体装置となる。
【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】
まず、縦35ｍｍ、横20ｍｍ、厚さ３ｍｍの長方形状の銅−タングステン合金から成る基体２と、縦35ｍｍ、横20ｍｍ、高さ７ｍｍの長方形状の鉄−ニッケル−コバルト合金から成る枠体３とを切削加工により製作し、しかる後、これらを銀−銅ろう材で接合して容器本体を製作した。また、枠体３の側部には、外面側に径大部８ａ、内面側に径小部８ｂを有する貫通孔８を打抜き加工および切削加工により形成した。
【００４４】
次に、容器本体の全面に厚さ５μｍのニッケル層と厚さ0.5μｍの金層とを積層して成るめっき金属層９をめっき法により被着した。その後、貫通孔８の大径部８ａと小径部８ｂとの間の段差Ｔおよび大径部８ａの端部Ｔ１（幅0.20ｍｍ）において、ダイヤモンドが固着したリューターを用いてめっき金属層９の除去を行ない、めっき金属層９の非形成部とした。
【００４５】
また、外周導体４ａ、絶縁体４ｂおよび中心導体４ｃからなる同軸コネクタ４を別途準備し、この同軸コネクタ４を筒状のＰｂ−Ｓｎ半田に挿入した状態で貫通孔８の大径部８ａに嵌着してサンプルＡを作製した。
【００４６】
なお、Ｐｂ−Ｓｎ半田は、炉中でＮ_２雰囲気中で、ＳＵＳ製のヒーターブロックを熱源とし、150秒間380℃に加熱して溶融した。
【００４７】
比較例として、貫通孔８の内面の全面にニッケル層と金層とが被着していること以外は実施例と同じようにして、サンプルＢを作製した。
【００４８】
これらのサンプルＡ，Ｂの各10個について、10〜50ＧＨｚの周波数帯での高周波信号の反射損失の測定を行なった。また、ヘリウムガスのリーク量の測定を行なった。１×10^−９Ｐａ・ｍ^３／ｓｅｃ以下を合格とし、１×10^−９Ｐａ・ｍ^３／ｓｅｃを超えるものを不合格とした。その結果を表１に示す。
【００４９】
【表１】

【００５０】
表１より、サンプルＢはサンプルＡと比較して15ＧＨｚ以上の周波数帯において反射損失が大きくなった。また、サンプルＢはサンプルＡと比較してヘリウムガスのリーク発生率も高くなった。
【００５１】
なお、本発明は上述の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なうことは何ら支障ない。例えば、半導体素子５が、半導体レーザ（ＬＤ）やフォトダイオード（ＰＤ）等の光半導体素子であってもよい。
【００５２】
【発明の効果】
本発明の半導体素子収納用パッケージは、貫通孔は大径部の内周面のうちで小径部側の端部を除く部位にめっき金属層が形成されており、その端部から大径部と小径部との間の段差を経て段差側の小径部の端までの部位がめっき金属層の非形成部とされていることから、枠体の貫通孔に同軸コネクタの外周導体をろう付けする際に、ろう材がめっき金属層の表面を濡れ広がって貫通孔の大径部から小径部まで流れ込むのを、大径部の内周面の小径部側の端部で効果的に防ぐことができる。その結果、同軸コネクタの中心導体と小径部との間のエアギャップを均一とすることができ、中心導体に対する接地性（接地電位部の同軸性）が確保されて、良好な高周波特性が得られる。
【００５３】
また、ろう材が貫通孔の大径部から小径部まで流れ込むのを防ぐためにその量を少なくする必要がないため、同軸コネクタの外周導体の外周面の全面のほとんどにろう材が付着するため、外周導体の接地性が良好になり良好な高周波特性が得られるとともに、十分な気密性が得られる。
【００５４】
さらに、ろう材は貫通孔の大径部と小径部との間の段差にも流れ込まないので、同軸コネクタを貫通孔の上記段差に隙間なく当接させて嵌着でき、高い位置精度で同軸コネクタを枠体に設置することができる。また、ろう材は貫通孔の内周面の大径部の小径部側の端部付近において裾野状の傾斜したメニスカスを形成するため、同軸コネクタの接合強度が向上することとなる。
【００５５】
本発明の半導体装置は、本発明の半導体素子収納用パッケージと、載置部に載置固定されるとともに同軸コネクタの中心導体に電気的に接続された半導体素子と、枠体の上面に取着された蓋体とを具備していることにより、良好な高周波特性および十分な気密性が得られる、高性能で高信頼性のものとなる。
【図面の簡単な説明】
【図１】本発明の半導体素子収納用パッケージの実施の形態の一例を示す断面図である。
【図２】本発明の半導体素子収納用パッケージについて実施の形態の他の例を示す要部断面図である。
【図３】本発明の半導体素子収納用パッケージについて実施の形態の他の例を示す要部断面図である。
【図４】本発明の半導体素子収納用パッケージについて実施の形態の他の例を示す要部断面図である。
【図５】従来の半導体素子収納用パッケージの例を示す断面図である。
【符号の説明】
１：半導体素子収納用パッケージ
２：基体
２ａ：載置部
３：枠体
４：同軸コネクタ
４ａ：外周導体
４ｂ：絶縁体
４ｃ：中心導体
５：半導体素子
６：ろう材
８：貫通孔
８ａ：大径部
８ｂ：小径部
Ｔ：段差[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device housing package and a semiconductor device for housing various semiconductor devices operating in a high frequency band, which are used in the fields of optical communication, microwave communication, millimeter wave communication, and the like.
[0002]
[Prior art]
FIG. 5 shows a package for housing a semiconductor element (hereinafter also referred to as a package) that accommodates various semiconductor elements that operate in response to a high-frequency signal and is used in the fields of conventional optical communication, microwave communication, millimeter wave communication, and the like. . As shown in FIG. 5, the package 101 generally has a base 102 made of a metal such as an iron (Fe) -nickel (Ni) -cobalt (Co) alloy or a copper (Cu) -tungsten (W) alloy. The base 102 has a mounting portion 102a on the upper surface of which a semiconductor element 105 such as an LD (semiconductor laser), PD (photodiode), IC, LSI or the like is mounted via a mounting base 107. The package 101 is mainly composed of a base body 102 and a frame body 103 made of a metal such as an iron-nickel-cobalt alloy or a copper-tungsten alloy and joined to the upper surface of the base body 102 so as to surround the mounting portion 102a. It is configured. The frame 103 is joined to the upper surface of the base 102 via a brazing material such as silver brazing.
[0003]
In the frame 103, a coaxial connector 104, which is an insulating terminal for electrically connecting the semiconductor element 105 and an external electric circuit, is fitted and joined to a through hole 108 provided on a side portion thereof. The coaxial connector 104 includes a cylindrical outer peripheral conductor 104a made of a metal such as iron-nickel-cobalt alloy, an insulator 104b, and a center conductor 104c. As the insulator 104b, borosilicate glass or the like is filled in the outer conductor 104a. The central conductor 104c is inserted into the central axis portion of the insulator 104b and has a function of conducting the inside and outside of the package 101. Further, the outer peripheral conductor 104a is fixed to the inner peripheral surface of the through hole 108 provided in the side portion of the frame 103 with a brazing material 106 such as gold-tin alloy solder. The coaxial connector 104 has a function of electrically connecting an external electric circuit and the semiconductor element 105 and also has a function of sealing the inside of the package 101 in an airtight manner.
[0004]
The through hole 108 of the frame body 103 has a large diameter portion 108a on the outer surface side of the frame body 103 and a small diameter portion 108b coaxially connected to the large diameter portion 108a on the inner surface side, and is formed on the inner peripheral surface of the large diameter portion 108a. The outer peripheral surface of the outer peripheral conductor 104 a is joined via the brazing material 106. In addition, a plated metal layer 109 made of a metal such as nickel or gold is applied to the entire inner peripheral surface of the through hole 108 in order to improve the brazing property with the outer peripheral surface of the outer peripheral conductor 104a. .
[0005]
In addition, the electrical connection between the coaxial connector 104 and the semiconductor element 105 is performed by placing a mounting base 107 on one end of the center conductor 104c protruding inside the frame 103 and the mounting portion 102a. The semiconductor element 105 and the circuit board 107a are mounted, and the central conductor 104c and the wiring conductor 107b formed on the surface of the circuit board 107a are brazed with a low melting point brazing material such as gold-tin alloy solder, and the wiring conductor 107b and the semiconductor are connected. This is performed by connecting the element 105 to a conductive connecting member 110 such as a bonding wire. Alternatively, the semiconductor element 105 is directly mounted and fixed on the mounting portion 102a, and the central conductor 104c and the semiconductor element 105 are connected by the conductive connection member 110.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-94167
[Problems to be solved by the invention]
However, in the conventional package 101, the brazing material 106 is plated in the step of brazing the outer peripheral conductor 104a of the coaxial connector 104 to the through hole 108 formed in the side portion of the frame 103 with the brazing material 106 such as solder. The surface of the metal layer 109 spreads wet and easily flows from the large diameter portion 108a to the small diameter portion 108b of the through hole 108. In this case, the distance between the central conductor 104c and the small diameter portion 104c of the coaxial connector 104 changes, and a predetermined air gap is formed. a cannot be secured, and the grounding property with respect to the central conductor 104c becomes unstable, so that there is a problem that a good high frequency characteristic cannot be obtained.
[0008]
Further, if the amount of the brazing material 106 is reduced in order to prevent the brazing material 106 from flowing from the large diameter portion 108a to the small diameter portion 108b of the through hole 108, the brazing material 106 is formed on the entire outer peripheral surface of the outer peripheral conductor 104a of the coaxial connector 104. Is difficult to adhere, the grounding property of the outer conductor 104a is deteriorated, and good high frequency characteristics cannot be obtained, and the package is not airtight.
[0009]
Accordingly, the present invention has been completed in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a high-frequency characteristic in a coaxial connector and to seal a semiconductor element in a hermetically sealed manner. It is to provide a package and a semiconductor device.
[0010]
[Means for Solving the Problems]
The package for housing a semiconductor element of the present invention has a base having a mounting portion on which a semiconductor element is mounted on an upper surface, and is attached to the upper surface of the base so as to surround the mounting portion, and is attached to a side portion from an outer surface. A frame body that penetrates to the inner surface, has a large-diameter portion on the outer surface side, and a through-hole having a small-diameter portion that is coaxially connected to the large-diameter portion on the inner surface side, and a plated metal layer formed on the surface; It consists of an outer peripheral conductor, a central conductor installed on the central axis thereof, and an insulator interposed therebetween, and the outer peripheral surface of the outer peripheral conductor is joined to the inner peripheral surface of the large-diameter portion of the through hole via a brazing material. In the package for housing a semiconductor element, wherein the central conductor is electrically connected to the semiconductor element, the through hole is formed on the small diameter portion side of the inner peripheral surface of the large diameter portion. The part except for the end A plated metal layer is formed, and a portion from the end portion through the step between the large diameter portion and the small diameter portion to the end of the small diameter portion on the step side is a portion where the plated metal layer is not formed It is said that it is said.
[0011]
In the package for housing a semiconductor element of the present invention, the through hole has a plated metal layer formed on a portion of the inner peripheral surface of the large-diameter portion excluding the end portion on the small-diameter portion side. When brazing the outer peripheral conductor of the coaxial connector to the through-hole of the frame body, the portion from the step to the small-diameter portion on the step side to the end of the small-diameter portion is the non-formed portion of the plated metal layer. In addition, it is possible to effectively prevent the brazing material from getting wet from spreading on the surface of the plated metal layer and flowing from the large diameter portion to the small diameter portion of the through hole at the end portion on the small diameter portion side of the inner peripheral surface of the large diameter portion. . As a result, the air gap between the center conductor and the small diameter portion of the coaxial connector can be made uniform, and the grounding property (coaxiality of the ground potential portion) with respect to the center conductor is ensured, and good high frequency characteristics can be obtained. .
[0012]
Moreover, since it is not necessary to reduce the amount of brazing material to prevent the brazing material from flowing from the large diameter portion of the through hole to the small diameter portion, the brazing material adheres to almost the entire outer peripheral surface of the outer peripheral conductor of the coaxial connector. The grounding property of the outer peripheral conductor is improved and good high frequency characteristics are obtained, and sufficient airtightness is obtained.
[0013]
Further, since the brazing material does not flow into the step between the large-diameter portion and the small-diameter portion of the through hole, the coaxial connector can be fitted in contact with the step of the through hole without any gap, and the coaxial connector can be fitted with high positional accuracy. Can be installed on the frame. Further, since the brazing material forms an inclined meniscus in the vicinity of the end on the small diameter side of the large diameter portion of the inner peripheral surface of the through hole, the joint strength of the coaxial connector is improved.
[0014]
The semiconductor device of the present invention includes a semiconductor element storage package of the present invention, a semiconductor element mounted and fixed on the mounting portion and electrically connected to the central conductor of the coaxial connector, and the frame body. And a lid attached to the upper surface.
[0015]
With the above structure, the semiconductor device of the present invention has high performance and high reliability that can provide good high-frequency characteristics and sufficient airtightness.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The semiconductor element storage package of the present invention will be described in detail below. FIG. 1 is a cross-sectional view showing an example of an embodiment of a package of the present invention. In FIG. 1, 2 is a base, 3 is a frame body, and 4 is a coaxial connector. Is configured. Further, 5 is a semiconductor element, 6 is a brazing material, 7 is a mounting base, 7a is a circuit board, 7b is a wiring conductor, 8 is a through hole, 9 is a plated metal layer, and 10 is a bonding wire.
[0017]
In FIG. 1, the semiconductor element 5 is placed on the placement portion 2a via the placement base 7, but the semiconductor element 5 may be placed directly on the placement portion 2a.
[0018]
The package of the present invention is mounted on the upper surface of the base body 2 having the mounting portion 2a on which the semiconductor element 5 is mounted, and on the upper surface of the base body 2 so as to surround the mounting portion 2a. A through-hole 8 having a large diameter portion 8a on the outer surface side and a small diameter portion 8b coaxially connected to the large diameter portion 8a on the inner surface side and a plated metal layer 9 formed on the surface; The outer peripheral conductor 4a, the central conductor 4c installed on the central axis thereof, and the insulator 4b interposed therebetween, the outer peripheral surface of the outer peripheral conductor 4a being the brazing material 6 on the inner peripheral surface of the large diameter portion 8a of the through hole 8 And a coaxial connector 4 in which the central conductor 4c is electrically connected to the semiconductor element 5, and the through hole 8 is formed on the small diameter portion 8b side of the inner peripheral surface of the large diameter portion 8a. A plated metal layer 9 is formed on the portion excluding the end, Site to the end of the step T side of the small diameter portion 8b through a step T between the large diameter portion 8a and a small diameter portion 8b is a non-forming portion of the plating metal layer 9 from the parts.
[0019]
The substrate 2 in the present invention has a function as a support member for supporting the semiconductor element 5 and a heat radiating plate for radiating heat generated by the semiconductor element 5, and the semiconductor element 5 is mounted at the center of the upper surface thereof. It has the mounting part 2a mounted via the mounting base 7. The mounting base 7 is bonded to the mounting portion 2a via a low melting point solder such as tin-lead solder, and the heat of the semiconductor element 5 is externally applied via the mounting base 7 and the low melting point solder. Thus, the semiconductor element 5 has good operability.
[0020]
The substrate 2 is made of a metal such as an iron-nickel-cobalt alloy or a copper-tungsten alloy, and is manufactured in a rectangular shape by subjecting the ingot to conventionally known metal processing such as rolling or punching. Further, a metal having excellent corrosion resistance and wettability with the brazing material 6, specifically, a nickel layer having a thickness of 0.5 to 9 μm and a gold layer having a thickness of 0.5 to 9 μm are sequentially deposited by plating. The base 2 can be effectively prevented from being oxidatively corroded, and the mounting base 7 can be firmly joined to the upper surface of the base 2 via the brazing material.
[0021]
The mounting base 7 is made of a metal having high thermal conductivity such as silicon (Si) or a copper-tungsten alloy, and ceramics such as alumina (Al ₂ O ₃ ) sintered body (alumina ceramics) on the upper surface. A circuit board 7a for impedance matching and the like having a wiring conductor 7b made of a metallized layer as a transmission line formed on the upper surface is joined. The wiring conductor 7b is a microstrip line formed so as to have the same impedance as that of the central conductor 4c of the coaxial connector 4. The wiring conductor 7b is connected to the semiconductor element 5 via the bonding wire 10 and is connected to the central conductor 4c by gold-tin. It is connected via a low melting point brazing material such as an alloy solder and has a function of electrically connecting the central conductor 4c of the coaxial connector 4 and the semiconductor element 5.
[0022]
In addition, a frame 3 is joined to the upper surface of the base 2 via a brazing material such as silver brazing so as to surround the mounting portion 2a. The frame body 3 has a through-hole 8 penetrating from the outer surface to the inner surface on a side portion thereof, and the coaxial connector 4 is fitted and joined to the through-hole 8. The frame 3 is made of a metal such as an iron-nickel-cobalt alloy or a copper-tungsten alloy, and is manufactured in a predetermined shape by subjecting the ingot to conventionally known metal processing such as rolling or punching. Alternatively, it may be formed integrally with the base 2. Further, a metal having excellent corrosion resistance and wettability with a brazing material, specifically, a nickel layer having a thickness of 0.5 to 9 μm and a gold layer having a thickness of 0.5 to 9 μm are sequentially deposited on the surface by a plating method. The plated metal layer 9 is formed, whereby it is possible to effectively prevent the frame 3 from being oxidatively corroded and to firmly join the outer peripheral conductor 4a of the coaxial connector 4 to the inner peripheral surface of the through hole 8. Can do.
[0023]
The coaxial connector 4 fitted in the through hole 8 has a function of electrically connecting the semiconductor element 5 and an external electric circuit, and a function of sealing the inside of the package 1 in an airtight manner. The outer peripheral conductor 4 a of the coaxial connector 4 is a cylindrical body made of metal and has a function as a grounding portion, and the outer peripheral surface thereof is a brazing material 6 such as gold-tin alloy solder on the inner peripheral surface of the through hole 8. It is brazed. The insulator 4b of the coaxial connector 4 is made of an insulator such as borosilicate glass and has a function of insulating the outer peripheral conductor 4a and the center conductor 4c. The central conductor 4c of the coaxial connector 4 is inserted into the central axis portion of the insulator 4b and has a function of electrically connecting the semiconductor element 5 and an external electric circuit.
[0024]
The outer conductor 4a and the center conductor 4c are made of a metal such as iron-nickel-cobalt alloy or copper-tungsten alloy, and the ingot is formed into a cylindrical shape or a rod shape by performing conventionally known metal processing such as rolling or stamping. It is formed. Further, a metal having excellent corrosion resistance and wettability with the brazing material 6, specifically, a nickel layer having a thickness of 0.5 to 9 μm and a gold layer having a thickness of 0.5 to 9 μm are sequentially deposited by plating. The outer peripheral conductor 4a and the central conductor 4c can be effectively prevented from being oxidatively corroded, and the outer peripheral surface of the outer peripheral conductor 4a and the inner peripheral surface of the through hole 8, the central conductor 4c and the external electric circuit, and the center The conductor 4c and the wiring conductor 7b of the circuit board 7a can be firmly joined.
[0025]
The coaxial connector 4 has a coaxial structure in which the center conductor 4c and the outer peripheral conductor 4a through which high-frequency signals are transmitted can perform impedance matching during signal transmission, so that the frequency of the transmitted high-frequency signals is high. Even if it becomes, the site | part which becomes difficult to match an impedance does not appear in the center conductor 4c.
[0026]
In the package 1 of the present invention, the through-hole 8 is formed with a plated metal layer 9 in a portion of the inner peripheral surface of the large-diameter portion 8a excluding the end portion on the small-diameter portion 8b side. The portion from the large diameter portion 8 a to the end of the small diameter portion 8 b on the step T side through the step T between the large diameter portion 8 a and the small diameter portion 8 b is a non-formed portion of the plated metal layer 9. Thereby, when the outer peripheral conductor 4a of the coaxial connector 4 is brazed to the through hole 8 of the frame body 3, the brazing material 6 wets and spreads the surface of the plated metal layer 9, and the small diameter portion from the large diameter portion 8a of the through hole 8 is obtained. It is possible to effectively prevent the flow up to 8b at the end portion on the small diameter portion 8b side of the inner peripheral surface of the large diameter portion 8a. As a result, the air gap A between the central conductor 4c and the small-diameter portion 8b of the coaxial connector 4 can be made uniform, and the grounding property (coaxiality of the ground potential portion) with respect to the central conductor 4c is ensured. High frequency characteristics can be obtained.
[0027]
Further, since it is not necessary to reduce the amount of the brazing material 6 in order to prevent the brazing material 6 from flowing from the large diameter portion 8a to the small diameter portion 8b of the through hole 8, almost all of the outer peripheral surface of the outer peripheral conductor 4a of the coaxial connector 4 will be used. Since the material 6 adheres, the grounding property of the outer peripheral conductor 4a is improved and good high frequency characteristics are obtained, and sufficient airtightness is obtained.
[0028]
Further, since the brazing material 6 does not flow into the step T between the large diameter portion 8a and the small diameter portion 8b of the through hole 8, the coaxial connector 4 can be fitted into the step T of the through hole 8 with no gap. The coaxial connector 4 can be installed on the frame 3 with high positional accuracy. Further, since the brazing material 6 forms a skirt-like inclined meniscus in the vicinity of the end portion on the small diameter portion 8b side of the large diameter portion 8a on the inner peripheral surface of the through hole 8, the joint strength of the coaxial connector 4 is improved. Become.
[0029]
The non-formed portion of the plated metal layer 9 is provided by the following method. First, a base material such as an iron-nickel-cobalt alloy or a copper-tungsten alloy to be the frame body 3 is prepared, and the base body 3 is manufactured by subjecting this base material to a conventionally known rolling process or punching process. Next, the through-hole 8 is formed in the side portion of the frame body 3, and the outer diameter side of the frame body 3 has a larger diameter than the diameter of the outer peripheral conductor 4 a of the coaxial connector 4 using a conventionally known punching or cutting method. The portion 8 a and the inner surface side are perforated so as to be a small diameter portion 8 b having a diameter smaller than the diameter of the outer peripheral conductor 4 a of the coaxial connector 4.
[0030]
Next, a nickel layer having a thickness of 0.5 to 9 μm and a gold layer having a thickness of 0.5 to 9 μm are sequentially deposited on the entire surface of the frame 3 by a plating method, and thereafter, the large diameter portion 8a and the small diameter portion 8b are formed. The step on the small diameter portion 8b side (hereinafter referred to as the end portion T1) on the step T between them and the inner peripheral surface of the large diameter portion 8a is mechanically polished using a router having a diamond or other abrasive material fixed to the tip. Then, the plated metal layer 9 is removed, and the step T and the end T1 are defined as portions where the plated metal layer 9 is not formed.
[0031]
Alternatively, before depositing the plating metal layer 9 on the entire surface of the frame 3, the step T and the end T1 are made of vinyl tape or overcoat resin having chemical resistance (alkali resistance or acid resistance) to the plating solution. The step T and the end T1 may be made non-formed portions of the plated metal layer 9 by masking in advance with a (protective resin layer) or the like and removing the mask after the plated metal layer 9 is deposited.
[0032]
In the present invention, the width of the end T1 (the axial width of the coaxial connector 4) is preferably 0.10 to 0.50 mm. If it is less than 0.10 mm, the brazing material 6 is likely to enter the step T. If it exceeds 0.50 mm, the joint strength of the outer peripheral conductor 4a of the coaxial connector 4 is reduced, and the portion that is not grounded to the frame 3 on the outer peripheral surface of the outer peripheral conductor 4a becomes large, and the grounding property of the outer peripheral conductor 4a becomes unstable. easy.
[0033]
Moreover, in this invention, as shown in FIGS. 2-4, you may form the groove | channel 11 over the perimeter in the edge part T1 vicinity of the non-formation part of the plating metal layer 9. FIG.
[0034]
FIG. 2 shows a groove 11 formed at the end T1 adjacent to the end of the plated metal layer 9. In this case, even if the brazing material 6 spreads toward the step T, it is effectively prevented by the groove 11. can do.
[0035]
FIG. 3 shows an end portion T1 provided with a groove 11 in which the end of the plated metal layer 9 is formed halfway along the inner surface (halfway along the bottom surface). In this case, the brazing material 6 spreads toward the step T. However, the groove 11 can be more effectively prevented. That is, the brazing material 6 is easily drawn into the groove 11 by the plated metal layer 9 in the groove 11, but it is not easy to enter the narrow gap on the step T side from the groove 11.
[0036]
FIG. 4 shows a groove 11 in which the plated metal layer 9 is formed on the entire inner surface at the end T1, and a groove 11 in which the end of the plated metal layer 9 reaches the opening. Can be effectively prevented by the groove 11 even if it is going to spread toward the step T. In this case, the brazing material 6 is easily attracted and accumulated in the groove 11 by the plated metal layer 9 in the groove 11 and is blocked by the groove 11.
[0037]
The coaxial connector 4 is fitted into the through hole 8 by the following method. First, a high temperature (high melting point) in a cylindrical shape with a thickness of 0.2 to 0.5 mm, whose inner diameter is larger than the diameter of the outer peripheral conductor 4a of the coaxial connector 4 and smaller in outer diameter than the diameter of the large diameter portion 8a of the through hole 8. 280-290 ° C.) Pb—Sn solder (Pb: Sn = 9: 1) is prepared. The length of the cylindrical Pb—Sn solder is substantially the same as the length of the outer conductor 4a.
[0038]
In addition, such a cylindrical solder is manufactured by cutting a cylindrical solder into a predetermined length and then forming a through hole by punching.
[0039]
Next, the coaxial connector 4 inserted into the cylindrical solder is inserted into the large diameter portion 8a of the through hole 8 of the frame 3, and the frame 3 is put in a furnace in this state to oxidize the flux and the frame 3. In order to prevent this, in a N ₂ atmosphere, a heater block made of stainless steel (SUS) is used as a heat source and heated to a temperature of 300 to 400 ° C. for about 1 to 3 minutes. As a result, the solder is melted and the outer peripheral surface of the outer peripheral conductor 4 a of the coaxial connector 4 is joined to the inner peripheral surface of the large-diameter portion 8 a of the through hole 8. In this case, the solder may be melted by maintaining the peak temperature at 300 to 400 ° C. and maintaining it for about 1 to 3 minutes in a continuous furnace filled with N ₂ .
[0040]
Further, a lid body (not shown) made of an insulating material such as a metal such as iron-nickel-cobalt alloy or alumina ceramics is joined to the upper surface of the frame body 3, whereby the base body 2, the frame body 3 and the lid body. The semiconductor element 5 is housed in an airtight manner in a container made of The lid is joined to the upper surface of the frame 3 by a welding method such as a seam welding method or a YAG laser welding method, or brazing with a low melting point brazing material such as gold-tin alloy solder.
[0041]
Thus, in the package 1 of the present invention, the semiconductor element 5 is mounted and fixed on the mounting portion 2a of the base 2, and each electrode of the semiconductor element 5 is electrically connected to the central conductor 4c of the coaxial connector 4 via the bonding wires 10 or the like. Next, a lid is attached to the upper surface of the frame 3, and the semiconductor element 5 is hermetically housed in a container composed of the base body 2, the frame 3, and the lid, and thereby the semiconductor device Become.
[0042]
【Example】
Embodiments of the semiconductor element storage package of the present invention will be described below.
[0043]
First, a base 2 made of a rectangular copper-tungsten alloy having a length of 35 mm, a width of 20 mm, and a thickness of 3 mm, and a frame 3 made of a rectangular iron-nickel-cobalt alloy having a length of 35 mm, a width of 20 mm, and a height of 7 mm; After that, the container body was manufactured by joining them with a silver-copper brazing material. Moreover, the through-hole 8 which has the large diameter part 8a in the outer surface side and the small diameter part 8b in the inner surface side was formed in the side part of the frame 3 by punching and cutting.
[0044]
Next, a plated metal layer 9 formed by laminating a nickel layer having a thickness of 5 μm and a gold layer having a thickness of 0.5 μm was applied to the entire surface of the container body by a plating method. Thereafter, at the step T between the large diameter portion 8a and the small diameter portion 8b of the through-hole 8 and the end portion T1 (width 0.20 mm) of the large diameter portion 8a, the plating metal layer 9 is removed using a router to which diamond is fixed. The plating metal layer 9 was not formed.
[0045]
In addition, a coaxial connector 4 comprising an outer peripheral conductor 4a, an insulator 4b, and a center conductor 4c is separately prepared, and the coaxial connector 4 is fitted into the large-diameter portion 8a of the through hole 8 in a state where the coaxial connector 4 is inserted into a cylindrical Pb-Sn solder. A sample A was prepared.
[0046]
The Pb—Sn solder was melted by heating at 380 ° C. for 150 seconds in a furnace in an N ₂ atmosphere using a SUS heater block as a heat source.
[0047]
As a comparative example, a sample B was produced in the same manner as in the example except that a nickel layer and a gold layer were deposited on the entire inner surface of the through hole 8.
[0048]
For each of 10 samples A and B, the reflection loss of the high-frequency signal in the frequency band of 10 to 50 GHz was measured. In addition, the amount of leak of helium gas was measured. 1 × 10 ⁻⁹ Pa · m ³ / sec or less was accepted and those exceeding 1 × 10 ⁻⁹ Pa · m ³ / sec were rejected. The results are shown in Table 1.
[0049]
[Table 1]

[0050]
From Table 1, the reflection loss of Sample B was larger than that of Sample A in the frequency band of 15 GHz or higher. Sample B also had a higher incidence of helium gas leak than Sample A.
[0051]
It should be noted that the present invention is not limited to the above-described embodiment and examples, and various modifications can be made without departing from the gist of the present invention. For example, the semiconductor element 5 may be an optical semiconductor element such as a semiconductor laser (LD) or a photodiode (PD).
[0052]
【The invention's effect】
In the package for housing a semiconductor element of the present invention, the through hole has a plated metal layer formed on a portion of the inner peripheral surface of the large-diameter portion excluding the end portion on the small-diameter portion side. When brazing the outer peripheral conductor of the coaxial connector to the through-hole of the frame body, the portion from the step to the small-diameter portion on the step side to the end of the small-diameter portion is the non-formed portion of the plated metal layer. In addition, it is possible to effectively prevent the brazing material from getting wet from spreading on the surface of the plated metal layer and flowing from the large diameter portion to the small diameter portion of the through hole at the end portion on the small diameter portion side of the inner peripheral surface of the large diameter portion. . As a result, the air gap between the center conductor and the small diameter portion of the coaxial connector can be made uniform, and the grounding property (coaxiality of the ground potential portion) with respect to the center conductor is ensured, and good high frequency characteristics can be obtained. .
[0053]
Moreover, since it is not necessary to reduce the amount of brazing material to prevent the brazing material from flowing from the large diameter portion of the through hole to the small diameter portion, the brazing material adheres to almost the entire outer peripheral surface of the outer peripheral conductor of the coaxial connector. The grounding property of the outer peripheral conductor is improved and good high frequency characteristics are obtained, and sufficient airtightness is obtained.
[0054]
Further, since the brazing material does not flow into the step between the large-diameter portion and the small-diameter portion of the through hole, the coaxial connector can be fitted in contact with the step of the through hole without any gap, and the coaxial connector can be fitted with high positional accuracy. Can be installed on the frame. Further, since the brazing material forms an inclined meniscus in the vicinity of the end on the small diameter side of the large diameter portion of the inner peripheral surface of the through hole, the joint strength of the coaxial connector is improved.
[0055]
A semiconductor device according to the present invention includes a semiconductor element storage package according to the present invention, a semiconductor element mounted and fixed on the mounting portion and electrically connected to the central conductor of the coaxial connector, and an upper surface of the frame. By providing the lid, the high-performance and high-reliability can be obtained with good high-frequency characteristics and sufficient airtightness.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of a package for housing a semiconductor element of the present invention.
FIG. 2 is a cross-sectional view of a main part showing another example of the embodiment of the package for housing a semiconductor element of the present invention.
FIG. 3 is a cross-sectional view of an essential part showing another example of the embodiment of the package for housing a semiconductor element of the present invention.
FIG. 4 is a cross-sectional view of a principal part showing another example of the embodiment of the package for housing a semiconductor element of the present invention.
FIG. 5 is a cross-sectional view showing an example of a conventional package for housing semiconductor elements.
[Explanation of symbols]
1: Semiconductor element storage package 2: Base 2a: Placement part 3: Frame body 4: Coaxial connector 4a: Outer conductor 4b: Insulator 4c: Center conductor 5: Semiconductor element 6: Brazing material 8: Through hole 8a: Large Diameter portion 8b: Small diameter portion T: Step

Claims

A base having a mounting portion on which a semiconductor element is mounted, and a base portion that is attached to the upper surface of the base so as to surround the mounting portion and penetrates from an outer surface to an inner surface on a side portion. A through-hole having a small-diameter portion coaxially connected to the large-diameter portion is formed on the diameter portion and the inner surface side, and a frame body in which a plated metal layer is formed on the surface, and an outer peripheral conductor and a central axis thereof. A center conductor and an insulator interposed therebetween, an outer peripheral surface of the outer peripheral conductor is joined to an inner peripheral surface of the large-diameter portion of the through-hole via a brazing material, and the central conductor is connected to the semiconductor element In the package for housing a semiconductor element comprising a coaxial connector that is electrically connected, the through-hole is formed on the plated metal layer at a portion of the inner peripheral surface of the large-diameter portion excluding the end portion on the small-diameter portion side. Formed at the end And a portion from the step portion between the large diameter portion and the small diameter portion to the end of the small diameter portion on the step side is a non-formed portion of the plated metal layer. package.

The semiconductor element storage package according to claim 1, a semiconductor element mounted and fixed on the mounting portion and electrically connected to the central conductor of the coaxial connector, and attached to the upper surface of the frame body A semiconductor device comprising a lid.