JP3850313B2

JP3850313B2 - Semiconductor device

Info

Publication number: JP3850313B2
Application number: JP2002052425A
Authority: JP
Inventors: 久夫迫田; 一仁金指
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2002-02-27
Filing date: 2002-02-27
Publication date: 2006-11-29
Anticipated expiration: 2022-02-27
Also published as: JP2003258138A

Description

【０００１】
【発明の属する技術分野】
本発明は、ＩＣ，ＬＳＩ等の半導体素子を収納した半導体装置に関する。
【０００２】
【従来の技術】
従来、ＬＳＩ（大規模集積回路素子）などの半導体素子を内部に収容した半導体装置は、通常、酸化アルミニウム質焼結体等の電気絶縁材料から成り、その上面の略中央部に半導体素子を収容するための凹部およびその凹部周辺から外周部にかけて導出されたダングステン（Ｗ）、モリブデン（Ｍｏ）、マンガン（Ｍｎ）等の高融点金属粉末から成る複数個のメタライズ配線層を有する絶縁基体と、半導体素子を外部電気回路に電気的に接続するためにメタライズ配線層に銀ろう等のろう材を介してろう付けされた複数個の外部リード端子と、鉄−ニッケル−コバルト合金や鉄−ニッケル合金等の金属から成る金属蓋体とから構成されている。
【０００３】
そして、絶縁基体の凹部の底面に半導体素子をガラス、樹脂、ろう材等の接着剤を介して接着固定するとともに半導体素子の各電極をボンディングワイヤを介してメタライズ配線層に接続し、しかる後、絶縁基体上面に金属蓋体を溶接し、絶縁基体と金属蓋体とから成る容器内部に半導体素子を気密に収容することによって半導体装置となる。
【０００４】
なお、絶縁基体上に金属蓋体を溶接するには、絶縁基体の上面に鉄（Ｆｅ）−ニッケル（Ｎｉ）−コバルト（Ｃｏ）合金やＦｅ−Ｎｉ合金等の金属材料から成る金属枠体を予めろう付けしておくとともに、金属枠体に金属蓋体をシームウエルド法により溶接する方法が採用されている。このように、絶縁基体上にろう付けされた金属枠体に金属蓋体をシームウエルド法により溶接した半導体装置は、その気密信頼性が極めて高く、例えば通信衛星等に組み込まれて宇宙空間などで使用される。
【０００５】
【発明が解決しようとする課題】
しかしながら、この従来の半導体装置によれば、宇宙空間で使用した場合、宇宙空間における放射線が、原子量の小さな元素から構成されたＦｅ−Ｎｉ−Ｃｏ合金やＦｅ−Ｎｉ合金等からなる金属蓋体を透過して半導体素子の表面から侵入してしまい、半導体素子に誤動作を引き起すという問題が発生していた。
【０００６】
従って、本発明はかかる従来の問題に鑑み案出されたものであり、その目的は、半導体装置を通信衛星等に組み込んで放射線の影響の大きい宇宙空間等で使用する場合に、放射線が半導体素子の表面から侵入して半導体素子に誤動作を引起すことのない半導体装置を提供することにある。
【０００７】
【課題を解決するための手段】
本発明の半導体装置は、上面に凹部が形成された絶縁基体と、前記凹部の底面に載置された半導体素子と、前記絶縁基体の上面の前記凹部の周囲に取着された金属枠体と、該金属枠体の上面に接合されるとともに上側主面および／または下側主面の中央部に肉厚部が形成された金属蓋体と、前記肉厚部に接合されるとともに多孔質のタングステン焼結体に銅を含浸させて成る板部材とを具備しており、前記金属蓋体は前記肉厚部の側面に全周にわたって断面形状がＶ字状の溝が形成されているとともに、該溝の前記金属蓋体側の内面が前記肉厚部の側面に対して垂直になっていることを特徴とする。
【０００８】
本発明の半導体装置によれば、金属蓋体の上側主面および／または下側主面の中央部に肉厚部が形成された金属蓋体と、前記肉厚部に接合されるとともに多孔質のタングステン焼結体に銅を含浸させて成る板部材とを具備したことから、半導体装置を通信衛星等に組み込んで放射線の影響が大きい宇宙空間等で使用した場合、銅を含浸させた多孔質のタングステン焼結体から成る板部材により放射線が半導体素子に侵入するのを阻止することができ、半導体装置の放射線による劣化を抑制して半導体装置を長寿命化することができる。また、金属蓋体に形成された肉厚部により、板部材を金属蓋体に接合する際に、ろう材が金属蓋体の外周部へ流れ出すことを防止して金属蓋体を金属枠体に強固に溶接することができる。
【００１０】
本発明の半導体装置は、上記の構成により、板部材を肉厚部にろう付けした際にろう材が肉厚部の側面を濡れ広がって、金属枠体の金属蓋体との溶接部に達するのを防ぐことができる。その結果、金属蓋体を金属枠体に強固に溶接することができる。
【００１１】
【発明の実施の形態】
本発明の半導体装置を以下に詳細に説明する。図１は本発明の半導体装置の実施の形態の一例を示す断面図であり、１は絶縁基体、２は金属蓋体、３は板部材、４は半導体素子、５は金属枠体である。この絶縁基体１と金属枠体５および金属蓋体２とで半導体素子４を収容するための容器が構成される。
【００１２】
本発明の絶縁基体１は酸化アルミニウム質焼結体、ムライト質焼結体、窒化アルミニウム質焼結体、炭化珪素質焼結体、ガラスセラミックス焼結体等の電気絶縁材料から成り、その上面の略中央部に半導体素子４を収容するための空所を形成する凹部１ａが設けてあり、凹部１ａの底面には半導体素子４がろう材、ガラス、樹脂等の接着剤を介して接着固定される。
【００１３】
絶縁基体１は例えば酸化アルミニウム質焼結体から成る場合、酸化アルミニウム、酸化珪素、酸化マグネシウム、酸化カルシウム等の原料粉末に適当な有機バインダー、溶剤等を添加混合して泥漿状となし、これを従来周知のドクターブレード法やカレンダーロール法等によりシート状に成形してセラミックグリーンシート（セラミック生シート）を得、しかる後、セラミックグリーンシートに適当な打ち抜き加工を施すとともにこれを複数枚積層し、高温（約1600℃）で焼成することによって製作される。
【００１４】
また、絶縁基体１にはその上面の凹部１ａ周辺から外周縁にかけて複数個のメタライズ配線層９が被着形成されており、メタライズ配線層９の凹部１ａ周辺部には半導体素子４の各電極がボンディングワイヤ６を介して電気的に接続され、また絶縁基体１の外周縁に導出する部位には外部リード端子７がろう材を介してろう付けされる。このメタライズ配線層９は、外部電気回路に接続される外部リード端子７に半導体素子４の各電極を電気的に導通させる作用を為し、Ｗ，Ｍｏ，Ｍｎ等の高融点金属粉末から成る。
【００１５】
メタライズ配線層９は、例えば、Ｗ等の高融点金属粉末に適当な有機溶剤、溶媒を添加混合して得た金属ペーストを絶縁基体１となるセラミックグリーンシートに予め従来周知のスクリーン印刷法により所定パターンに印刷塗布しておくことによって絶縁基体１の所定位置に被着形成される。また、メタライズ配線層９は、その露出する表面にＮｉ，金（Ａｕ）等の耐蝕性に優れかつろう材と濡れ性の良い金属をメッキ法により１〜20μｍの厚みに層着させておくのがよく、メタライズ配線層９の酸化腐食を有効に防止できるとともにメタライズ配線層９とボンディングワイヤ６および外部リード端子７とのろう付け接合を強固にすることができる。
【００１６】
外部リード端子７は、半導体素子４の各電極を外部電気回路に電気的に接続する作用を為し、Ｆｅ−Ｎｉ−Ｃｏ合金やＦｅ−Ｎｉ合金等の金属材料から成り、絶縁基体１に被着したメタライズ配線層９にろう付けされている。この外部リード端子７は、Ｆｅ−Ｎｉ−Ｃｏ合金等のインゴット（塊）を圧延加工法や打ち抜き加工法等、従来周知の金属加工法により所定の板状に形成することによって製作される。
【００１７】
また、絶縁基体１の上面には、凹部１ａを囲繞するようにしてアルミナセラミックス等から成るセラミック枠体1ｂが積層されており、そのセラミック枠体１ｂの上面にメタライズ金属層８が枠状に被着形成されており、枠状のメタライズ金属層８には金属枠体５がろう材を介してろう付けされている。枠状のメタライズ金属層８は金属枠体５を絶縁基体１にろう付けする際の下地金属層であり、Ｗ，Ｍｏ，Ｍｎ等の高融点金属粉末によって形成され、メタライズ配線層９と同様の方法で形成される。具体的には、Ｗ等の高融点金属粉末に適当な有機溶剤、溶媒を添加混合して得た金属ペーストをセラミック枠体１ｂとなるセラミックグリーンシートに、予め従来周知のスクリーン印刷法により所定パターンに印刷塗布しておくことによって絶縁基体１の上面に枠状に被着形成される。
【００１８】
金属枠体５は、枠状のメタライズ金属層８に取着されており、金属蓋体２を絶縁基体１に取着する際の下地金属部材であり、絶縁基体１の上面のセラミック枠体1ｂに被着させたメタライズ金属層８に銀ろう等のろう材を介してろう付けすることによって絶縁基体１の上面に取着されている。そして、絶縁基体１の凹部１ａの底面に半導体素子４を接着固定するとともに半導体素子４の各電極とメタライズ配線層９とをボンディングワイヤ６を介して電気的に接続した後、金属枠体５の上面に金属蓋体２をシームウエルド法によって溶接することによって絶縁基体１と金属枠体５と金属蓋体２とから成る容器内部に半導体素子４が気密に封止される。この場合、Ｆｅ−Ｎｉ−Ｃｏ合金やＦｅ−Ｎｉ合金から成る金属枠体５に、同じくＦｅ−Ｎｉ−Ｃｏ合金やＦｅ−Ｎｉ合金から成る金属蓋体２をシームウエルド法により溶接することから、パッケージの気密信頼性が極めて高いものとなる。
【００１９】
金属枠体５および金属蓋体２はＦｅ−Ｎｉ−Ｃｏ合金やＦｅ−Ｎｉ合金等の金属材料から成り、Ｆｅ−Ｎｉ−Ｃｏ合金等のインゴット（塊）に所定の金属加工を施すことによって形成される。
【００２０】
さらに、金属蓋体２の上側主面および／または下側主面には、半導体素子４の表面から放射線（α線、β線、γ線、宇宙線等）の侵入を阻止するための板部材３が接合されている。この板部材３は、例えば多孔質のＷ焼結体に５〜30重量％の銅を含浸させたＣｕ−Ｗ複合材料から成り、Ａｇ−Ｃｕ合金等のろう材を介して金属蓋体２の下面に接合されている。この板部材３は、半導体装置内部に収容される半導体素子４の上方を覆うように、金属蓋体２の上側主面および／または下側主面の中央部に接合されており、半導体素子４に不要な放射線が半導体素子４の表面から侵入するのを防止する遮蔽部材として機能する。即ち、板部材３を構成するＷの原子量が180程度と大きなことから、放射線が金属蓋体２を透過するのを有効に阻止することができる。従って、放射線が半導体素子４の表面から侵入して半導体素子４に誤動作を引起すこともなくなる。
【００２１】
なお、板部材３の金属蓋体２へのろう付けは、金属蓋体２と板部材３とをそれらの間にろう材箔を挟んで重ね、約900℃の温度に加熱してろう材箔を溶融させることによって行われる。このとき、金属蓋体２の板部材３がろう付けされる中央部の厚みを金属枠体５に溶接される外周部の厚みよりも厚くして、金属蓋体２の板部材３がろう付けされる中央部と金属枠体５に溶接される外周部との間に高さが0.3〜2.0ｍｍ程度の肉厚部２ａを形成しておくことが好ましい。この肉厚部２ａにより、板部材３を金属蓋体２に接合する際に、ろう材が金属蓋体２の外周部へ流れ出すことが防止され、金属蓋体２の外周部に不要なろう材が付着しないので、金属蓋体２を金属枠体５に強固に溶接させることができる。肉厚部２ａの高さが0.3ｍｍ未満では、肉厚部２ａの高さが低いため、ろう材が金属蓋体２の外周部へ容易に流れ出してしまう。2.0ｍｍを超えると、金属蓋体２の厚みのために半導体装置が不要に厚いものとなってしまう。
【００２２】
さらに、図２に肉厚部２ａの部分拡大断面図を示す。（ａ）は肉厚部２ａの側面に全周にわたって断面形状がコ字状の溝を形成したものであり、（ｂ）は断面形状がＶ字状の溝を形成したものである。このように、肉厚部２ａの側面に溝を形成することでろう材が金属蓋体２の外周部へ流れ出すのをさらに防止することができる。また溝として、断面形状が略Ｖ字状のものであって、板部材３側（下側）の斜面が下側により傾斜して肉厚部２ａの側面に平行に近くなっているとともに、金属蓋体２側（上側）の斜面が肉厚部２ａの側面に略垂直になっている形状がよい。この場合、ろう材の濡れ広がりを確実に溝で阻止することができる。
【００２３】
また、板部材３は、その厚みが0.1ｍｍ未満では放射線の透過を十分に阻止することができなくなる傾向にあり、２ｍｍを超えると、板部材３の厚みのために半導体装置が不要に厚いものとなってしまう傾向にある。従って、板部材３の厚みは0.1〜２ｍｍが好ましい。
【００２４】
さらに、図２に示すように、肉厚部２ａの板部材３が接合される接合面は、板部材３の主面よりも大きいことがよい。この場合、接合面の外周部にろう材のメニスカスが形成されて肉厚部２ａの側面にろう材が這い上がらないようにすることができる。板部材３の周囲に0.1〜1.0ｍｍ程度の幅のろう付け部が全周にわたって形成されるように、肉厚部２ａの接合面が板部材３の主面よりも大きいことがより好ましい。0.1ｍｍ未満では、ろう材が肉厚部２ａの側面に這い上がり易くなり、1.0ｍｍを超えると、肉厚部2aの接合面が不要に大きなものとなってしまい、半導体装置の小型化に対して不適である。
【００２５】
また、板部材３を構成するＣｕ−Ｗ複合材料に含有されるＣｕは、その含有量が５重量％未満であると、板部材３の熱膨張係数がＦｅ−Ｎｉ−Ｃｏ合金やＦｅ−Ｎｉ合金等の金属から成る金属蓋体２の熱膨張係数よりも極めて小さいものとなる。30重量％を超えると、板部材３の熱膨張係数が金属蓋体２の熱膨張係数よりも極めて大きなものとなる。そして、いずれの場合にも、板部材３を金属蓋体２にろう付けする際に、両者の熱膨張係数の相違に起因して、金属蓋体２に大きな反りが発生し、金属蓋体２を金属枠体５にシームウエルド法で溶接するのが難しくなる。従って、板部材３を構成するＣｕ−Ｗ複合材料に含有されるＣｕの含有量は５〜30重量％が好ましい。
【００２６】
また、板部材３は、粒径が10μｍ程度のＷ粉末をプレス成形により約98000000Ｎ／ｍ²の圧力でブロック状に押し固めて、これを約2300℃の温度で焼成して多孔質のＷ焼結体を得、しかる後、1100℃の温度で加熱溶融させたＣｕをこのＷ焼結体の多孔部分に毛管現象を利用して含浸させることによって製作される。
【００２７】
なお、板部材３のろう付け面に、板部材３と金属蓋体２とのろう付けを容易で強固なものとするために、厚みが１〜５μｍ程度のＮｉめっき層を被着することが好ましい。
【００２８】
また、半導体素子４の上面への放射線の侵入を効果的に阻止するには、板部材３の主面の面積が半導体素子４の上面の面積よりも大きいことが好ましい。
【００２９】
かくして、本発明の半導体装置は、絶縁基体１の凹部１ａ底面に半導体素子４をろう材、ガラス、樹脂等の接着剤を介して接着固定するとともに半導体素子４の各電極をボンディングワイヤ６を介してメタライズ配線層９に電気的に接続し、しかる後、絶縁基体１の上面にろう付けした金属枠体５に金属蓋体２をシームウエルド法により溶接し、絶縁基体１と金属蓋体２とから成る容器内部に半導体素子４を気密に収容することによって最終製品としての半導体装置となる。
【００３０】
【実施例】
本発明の半導体装置の実施例を以下に説明する。
【００３１】
（実施例１）
図１の本発明の半導体装置を以下のようにして構成した。
【００３２】
酸化アルミニウム焼結体（アルミナセラミックス）から成る絶縁基体１の凹部１ａ底面に、ＬＳＩから成る半導体素子４を樹脂接着剤を介して接着固定した。このとき、Ｗから成るとともに表面に厚さ５μｍのＮｉメッキ層および厚さ1.2μｍのＡｕメッキ層を順次被着したメタライズ配線層９に、半導体素子４の各電極をボンディングワイヤ６を介して電気的に接続し、メタライズ配線層９の絶縁基体１の上面の外周部にＦｅ−Ｎｉ−Ｃｏ合金から成る外部リード端子７をＡｇろうでろう付けした。絶縁基体１上面の凹部１ａの周囲にはアルミナセラミックスから成るセラミック枠体１ｂを積層した。セラミック枠体１ｂの上面のＷから成るメタライズ金属層８に、Ｆｅ−Ｎｉ−Ｃｏ合金から成る金属枠体５をＡｇろうでろう付けし、金属枠体５の上面に、下側主面に板部材３をろう付けしたＦｅ−Ｎｉ−Ｃｏ合金から成る金属蓋体２をシームウェルド溶接法で溶接した。
【００３３】
板部材３として、Ｗ板、Ｃｕ板、Ｃｕの含有量を種々のものとしたＣｕ−Ｗ複合材料から成るものを作製し、それらを設けた半導体装置について、放射線（高エネルギーの２次宇宙線（γ線）に相当する放射線）を外部から照射した場合の遮蔽性、板部材３の接合性について評価した結果を表１に示す。なお、Ｗ板、Ｃｕ板の場合は平板状のものとし、Ｃｕ−Ｗ複合材料から成るものの場合は肉厚部２ａ以外の厚さが１ｍｍで肉厚部２ａの高さが１ｍｍであるものとした。また、表１でｗｔ％は重量％を意味する。
【００３４】
【表１】

【００３５】
表１より、Ｃｕの含有量が５〜30ｗｔ％のＣｕ−Ｗ複合材料から成る板部材３では、放射線の遮蔽性および接合性が良好であった。なお、遮蔽性については、放射線の透過によって半導体素子４に誤動作が生じなかったものを○、誤動作が生じたたものを×とした。接合性については、金属蓋体２の熱膨張係数と板部材３の熱膨張係数との相違によってこれらが変形し、金属蓋体２と板部材３との接合部で板部材３の剥れ等の接合不良が発生しなかったものを○、接合不良が発生したものを×とした。
【００３６】
遮蔽性について、Ｗ板およびＣｕの含有量が40ｗｔ％以下のＣｕ−Ｗ複合材料が、半導体素子４に誤動作が生じなかった。これは、原子量の大きいＷに対する原子量の小さいＣｕの含有量を40ｗｔ％以下とすることにより、板部材３の遮蔽効果が保持されたものである。接合性について、板部材３のＣｕの含有量が５〜30ｗｔ％のＣｕ−Ｗ複合材料で良好であった。それ以外では、板部材３の熱膨張係数とＦｅ−Ｎｉ−Ｃｏ合金から成る金属蓋体２の熱膨張係数との差により発生する熱応力が、ろう材を介して接合されている金属蓋体２と板部材３の接合部にかかり、この接合部から板部材３が剥れてしまった。
【００３７】
上記の結果より、遮蔽性および接合性を満足する板部材３はＣｕの含有量が５〜30ｗｔ％のＣｕ−Ｗ複合材料であることが判った。なお、ろう付け時（約800℃）のＦｅ−Ｎｉ−Ｃｏ合金の熱膨脹係数は6.2×10^-6／℃、Ｗの熱膨脹係数は5.0×10^-6／℃、Ｃｕの熱膨脹係数18.3×10^-6／℃である。
【００３８】
（実施例２）
また、Ｃｕの含有量を10重量％としたＣｕ−Ｗ複合材料から成り、肉厚部２ａ以外の厚さが１ｍｍで肉厚部２ａの高さを種々のものとした板部材３を設けた半導体装置を上記実施例１と同様にして作製した。これらの半導体装置について、板部材３を肉厚部２ａにＡｇろうでろう付けした際のＡｇろうの流れについて評価結果を表２に示す。なお、これらの半導体装置について、肉厚部２ａの板部材３が接合される接合面は、板部材３の主面よりも幅0.5ｍｍ分だけ全周にわたって大きいものとした。
【００３９】
【表２】

【００４０】
表２より、肉厚部２ａの高さは0.3ｍｍ以上が適合となった。なお、判定は、金属蓋体２の外周部に不要なＡｇろうが流れ出していない場合を○、流れ出している場合を×とした。肉厚部２ａの高さが0.1ｍｍ以下の場合、肉厚部２ａの高さが低いためＡｇろうが金属蓋体２の外周部へ流れ出した。この場合、金属蓋体２の外周部に不要なＡｇろうが付着し、金属蓋体２を金属枠体５に強固に溶接させることができなくなった。0.3ｍｍを超えると、Ａｇろうの流れ出しはなくなったが、2.0ｍｍを超えると、肉厚部２ａの厚みのために半導体装置が不要に厚いものとなった。これにより、肉厚部２ａの高さは0.3〜2.0ｍｍとするのが好ましいことがわかった。
【００４１】
（実施例３）
図２のように肉厚部２ａの側面に、断面形状がコ字状の溝Ａ、Ｖ字状の溝Ｂ、略Ｖ字状であって下側の斜面と肉厚部２ａ側面とのなす角が20°で上側の斜面と肉厚部２ａ側面とのなす角が90°である溝Ｃを形成した３種の半導体装置、および溝のない半導体装置を、上記実施例１と同様にして各10個ずつ作製した。これらについて、板部材３を肉厚部２ａにＡｇろうでろう付けした際のＡｇろうの流れについて評価結果を表３に示す。なお、これらの半導体装置について、肉厚部２ａの板部材３が接合される接合面が板部材３の主面よりも幅0.5ｍｍ分だけ全周にわたって大きくなるようにした。
【００４２】
【表３】

【００４３】
表３より、溝ＣはＡｇろうの流れ出しを完全に阻止していることが判った。なお、判定は、肉厚部２ａ以外の金属蓋体２へのＡｇろうの流れ出しがないものを○、Ａｇろうの流れ出しがあるものを×とした。溝のない肉厚部２ａに対し、溝Ａ、溝Ｂおよび溝Ｃは、溝内の角部にメニスカスが形成されＡｇろうの流れ出しを有効に防いでいる。
【００４４】
なお、本発明は上記実施の形態および実施例に限定されず、本発明の要旨を逸脱しない範囲内で種々の変更を施すことは何等差し支えない。例えば図２の溝は他の形状であってもよく、円弧状やＵ字状の溝でもよい。また、例えば図３に本発明の実施の形態の他の例を示すように、板部材３が金属蓋体２の上側主面に接合されていてもよい。この場合、板部材３が金属蓋体２の下側主面に接合された場合と同様に放射線が半導体素子４の表面から侵入するのを阻止できる。また、金属蓋体２の上下主面に板部材３が接合されていてもかまわない。さらに、絶縁基体1の下面にも板部材３を接合させて裏面側からの放射線の透過を阻止することもできる。
【００４５】
【発明の効果】
本発明の半導体装置は、上面に凹部が形成された絶縁基体と、凹部の底面に載置された半導体素子と、絶縁基体の上面の凹部の周囲に取着された金属枠体と、金属枠体の上面に接合されるとともに上側主面および／または下側主面の中央部に肉厚部が形成された金属蓋体と、肉厚部に接合されるとともに多孔質のタングステン焼結体に銅を含浸させて成る板部材とを具備したことにより、半導体装置を通信衛星等に組み込んで放射線の影響が大きい宇宙空間等で使用した場合、多孔質のタングステン焼結体に銅を含浸させて成る板部材により放射線が半導体素子に侵入するのを阻止することができ、半導体装置の放射線による劣化を抑制して半導体装置を長寿命化することができる。また、金属蓋体に形成された肉厚部により、板部材を金属蓋体に接合する際に、ろう材が金属蓋体の外周部へ流れ出すことを防止して金属蓋体を金属枠体に強固に溶接させることができる。
【００４６】
本発明の半導体装置は、好ましくは、金属蓋体は肉厚部の側面に全周にわたって溝が形成されていることにより、板部材を肉厚部にろう付けした際にろう材が肉厚部の側面を濡れ広がって、金属枠体の金属蓋体との溶接部に達するのを防ぐことができる。その結果、金属蓋体を金属枠体に強固に溶接することができる。
【図面の簡単な説明】
【図１】本発明の半導体装置について実施の形態の一例を示す断面図である。
【図２】（ａ），（ｂ）は本発明の半導体装置における金属蓋体の肉厚部について実施の形態の例をそれぞれ示す要部拡大断面図である。
【図３】本発明の半導体装置について実施の形態の他の例を示す断面図である。
【符号の説明】
１：絶縁基体
１ａ：凹部
１ｂ：セラミック枠体
２：金属蓋体
２ａ：肉厚部
３：板部材
４：半導体素子
５：金属枠体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device containing a semiconductor element such as an IC or LSI.
[0002]
[Prior art]
Conventionally, a semiconductor device in which a semiconductor element such as an LSI (Large Scale Integrated Circuit Element) is accommodated is usually made of an electrically insulating material such as an aluminum oxide sintered body, and the semiconductor element is accommodated in a substantially central portion on the upper surface thereof. An insulating substrate having a plurality of metallized wiring layers made of refractory metal powder such as dungsten (W), molybdenum (Mo), manganese (Mn), etc. A plurality of external lead terminals brazed to the metallized wiring layer through a brazing material such as silver brazing to electrically connect the element to an external electric circuit, and an iron-nickel-cobalt alloy, iron-nickel alloy, etc. And a metal lid made of a metal.
[0003]
Then, the semiconductor element is bonded and fixed to the bottom surface of the concave portion of the insulating base via an adhesive such as glass, resin, brazing material, and each electrode of the semiconductor element is connected to the metallized wiring layer via a bonding wire. A metal lid is welded to the upper surface of the insulating base, and the semiconductor element is hermetically accommodated inside a container composed of the insulating base and the metal lid, thereby forming a semiconductor device.
[0004]
In order to weld the metal lid on the insulating substrate, a metal frame made of a metal material such as iron (Fe) -nickel (Ni) -cobalt (Co) alloy or Fe-Ni alloy is provided on the upper surface of the insulating substrate. A method of brazing in advance and welding a metal lid to a metal frame by a seam weld method is employed. Thus, a semiconductor device in which a metal lid is welded to a metal frame brazed on an insulating substrate by a seam weld method has extremely high hermetic reliability, and is incorporated into a communication satellite or the like, for example, in outer space. used.
[0005]
[Problems to be solved by the invention]
However, according to this conventional semiconductor device, when used in outer space, the metal lid made of Fe-Ni-Co alloy, Fe-Ni alloy, or the like in which the radiation in outer space is composed of an element having a small atomic weight. There has been a problem that the light penetrates from the surface of the semiconductor element and causes a malfunction in the semiconductor element.
[0006]
Therefore, the present invention has been devised in view of such conventional problems, and the object thereof is to incorporate a semiconductor device into a communication satellite or the like and use the semiconductor device in a space where the influence of radiation is large. An object of the present invention is to provide a semiconductor device that does not enter from the surface of the semiconductor device and cause a malfunction in the semiconductor element.
[0007]
[Means for Solving the Problems]
The semiconductor device of the present invention includes an insulating base having a recess formed on the top surface, a semiconductor element placed on the bottom surface of the recess, and a metal frame attached around the recess on the top surface of the insulating base. A metal lid that is bonded to the upper surface of the metal frame and has a thick portion formed at the center of the upper main surface and / or the lower main surface, and is bonded to the thick portion and is porous. A plate member formed by impregnating a tungsten sintered body with copper, and the metal lid body has a V-shaped groove formed on the side surface of the thick portion over the entire circumference. An inner surface of the groove on the metal lid side is perpendicular to a side surface of the thick portion.
[0008]
According to the semiconductor device of the present invention, the metal lid body in which the thick portion is formed in the central portion of the upper main surface and / or the lower main surface of the metal lid body, and the porous portion that is joined to the thick portion and is porous Since the plate member made by impregnating copper into the tungsten sintered body of the above, the porous material impregnated with copper when the semiconductor device is incorporated in a communication satellite etc. and used in outer space where the influence of radiation is large The plate member made of the tungsten sintered body can prevent radiation from entering the semiconductor element, thereby suppressing deterioration of the semiconductor device due to radiation and extending the life of the semiconductor device. In addition, the thick portion formed on the metal lid prevents the brazing material from flowing out to the outer periphery of the metal lid when the plate member is joined to the metal lid, so that the metal lid is made into the metal frame. It can be firmly welded.
[0010]
In the semiconductor device of the present invention, with the above configuration, when the plate member is brazed to the thick part, the brazing material wets and spreads the side surface of the thick part and reaches the welded portion of the metal frame body with the metal lid. Can be prevented. As a result, the metal lid can be firmly welded to the metal frame.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The semiconductor device 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 semiconductor device according to the present invention. 1 is an insulating substrate, 2 is a metal lid, 3 is a plate member, 4 is a semiconductor element, and 5 is a metal frame. The insulating base 1, the metal frame 5 and the metal lid 2 constitute a container for housing the semiconductor element 4.
[0012]
The insulating substrate 1 of the present invention is made of an electrically insulating material such as an aluminum oxide sintered body, a mullite sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a glass ceramic sintered body, etc. A recess 1a that forms a space for accommodating the semiconductor element 4 is provided at a substantially central portion, and the semiconductor element 4 is bonded and fixed to the bottom surface of the recess 1a via an adhesive such as brazing material, glass, resin, or the like. The
[0013]
When the insulating substrate 1 is made of, for example, an aluminum oxide sintered body, an appropriate organic binder, solvent, etc. are added to and mixed with raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide to form a slurry. A ceramic green sheet (ceramic raw sheet) is obtained by molding into a sheet shape by a conventionally known doctor blade method or calendar roll method, etc., and thereafter, a suitable number of punching processes are applied to the ceramic green sheet, and a plurality of these are laminated, Manufactured by firing at high temperature (about 1600 ° C).
[0014]
In addition, a plurality of metallized wiring layers 9 are deposited on the insulating substrate 1 from the periphery of the recess 1a on the upper surface to the outer periphery, and each electrode of the semiconductor element 4 is formed around the recess 1a of the metallized wiring layer 9. External lead terminals 7 are brazed via a brazing material to portions that are electrically connected via bonding wires 6 and lead out to the outer peripheral edge of the insulating substrate 1. The metallized wiring layer 9 functions to electrically connect each electrode of the semiconductor element 4 to the external lead terminal 7 connected to an external electric circuit, and is made of a refractory metal powder such as W, Mo, or Mn.
[0015]
For example, the metallized wiring layer 9 is pre-determined in advance by a conventionally well-known screen printing method on a ceramic green sheet serving as the insulating substrate 1 by adding and mixing a suitable organic solvent and solvent with a refractory metal powder such as W. The insulating substrate 1 is deposited on a predetermined position by printing and applying to the pattern. Further, the metallized wiring layer 9 is formed by depositing a metal having excellent corrosion resistance such as Ni, gold (Au) and the like and brazing metal and good wettability on the exposed surface to a thickness of 1 to 20 μm by plating. Therefore, the oxidative corrosion of the metallized wiring layer 9 can be effectively prevented, and the brazed joint between the metallized wiring layer 9 and the bonding wire 6 and the external lead terminal 7 can be strengthened.
[0016]
The external lead terminal 7 serves to electrically connect each electrode of the semiconductor element 4 to an external electric circuit, and is made of a metal material such as Fe—Ni—Co alloy or Fe—Ni alloy. The metallized wiring layer 9 is brazed. The external lead terminal 7 is manufactured by forming an ingot (lump) such as an Fe-Ni-Co alloy into a predetermined plate shape by a conventionally known metal processing method such as a rolling method or a punching method.
[0017]
A ceramic frame 1b made of alumina ceramic or the like is laminated on the upper surface of the insulating substrate 1 so as to surround the recess 1a, and the metallized metal layer 8 is covered in a frame shape on the upper surface of the ceramic frame 1b. The metal frame 5 is brazed to the frame-like metallized metal layer 8 via a brazing material. The frame-like metallized metal layer 8 is a base metal layer when the metal frame 5 is brazed to the insulating substrate 1 and is formed of a refractory metal powder such as W, Mo, Mn, etc., and is similar to the metallized wiring layer 9. Formed by the method. Specifically, a metal paste obtained by adding and mixing an appropriate organic solvent and solvent to a refractory metal powder such as W is preliminarily formed in a predetermined pattern on a ceramic green sheet to be a ceramic frame 1b by a conventionally known screen printing method. By being printed and coated on the upper surface of the insulating substrate 1, it is formed in a frame shape.
[0018]
The metal frame 5 is attached to a frame-like metallized metal layer 8, and is a base metal member for attaching the metal lid 2 to the insulating base 1, and the ceramic frame 1 b on the upper surface of the insulating base 1. It is attached to the upper surface of the insulating substrate 1 by brazing the metallized metal layer 8 deposited on the metallized metal layer 8 via a brazing material such as silver brazing. Then, the semiconductor element 4 is bonded and fixed to the bottom surface of the recess 1 a of the insulating base 1 and each electrode of the semiconductor element 4 and the metallized wiring layer 9 are electrically connected via the bonding wires 6. The semiconductor element 4 is hermetically sealed inside the container composed of the insulating base 1, the metal frame 5, and the metal lid 2 by welding the metal lid 2 to the upper surface by the seam weld method. In this case, since the metal lid 2 also made of Fe-Ni-Co alloy or Fe-Ni alloy is welded to the metal frame 5 made of Fe-Ni-Co alloy or Fe-Ni alloy by the seam weld method, The hermetic reliability of the package is extremely high.
[0019]
The metal frame 5 and the metal lid 2 are made of a metal material such as an Fe—Ni—Co alloy or an Fe—Ni alloy, and are formed by subjecting an ingot such as an Fe—Ni—Co alloy to predetermined metal processing. Is done.
[0020]
Further, a plate member for preventing radiation (α rays, β rays, γ rays, cosmic rays, etc.) from entering the upper main surface and / or the lower main surface of the metal lid 2 from the surface of the semiconductor element 4. 3 is joined. The plate member 3 is made of, for example, a Cu-W composite material in which 5 to 30% by weight of copper is impregnated into a porous W sintered body, and the metal lid 2 is formed through a brazing material such as an Ag-Cu alloy. It is joined to the bottom surface. The plate member 3 is joined to the central portion of the upper main surface and / or the lower main surface of the metal lid 2 so as to cover the upper side of the semiconductor element 4 accommodated in the semiconductor device. It functions as a shielding member that prevents unnecessary radiation from entering from the surface of the semiconductor element 4. That is, since the atomic weight of W constituting the plate member 3 is as large as about 180, it is possible to effectively prevent radiation from passing through the metal lid 2. Therefore, radiation does not enter from the surface of the semiconductor element 4 and cause malfunction in the semiconductor element 4.
[0021]
The brazing of the plate member 3 to the metal lid 2 is performed by overlapping the metal lid 2 and the plate member 3 with a brazing filler metal foil sandwiched between them and heating to a temperature of about 900 ° C. By melting. At this time, the thickness of the central portion where the plate member 3 of the metal lid 2 is brazed is made thicker than the thickness of the outer peripheral portion welded to the metal frame 5, so that the plate member 3 of the metal lid 2 is brazed. It is preferable to form a thick portion 2 a having a height of about 0.3 to 2.0 mm between the central portion to be welded and the outer peripheral portion welded to the metal frame 5. The thick portion 2 a prevents the brazing material from flowing out to the outer peripheral portion of the metal lid 2 when the plate member 3 is joined to the metal lid 2, and is unnecessary for the outer peripheral portion of the metal lid 2. Therefore, the metal lid 2 can be firmly welded to the metal frame 5. If the thickness of the thick portion 2a is less than 0.3 mm, the thickness of the thick portion 2a is low, so that the brazing material easily flows out to the outer peripheral portion of the metal lid 2. If the thickness exceeds 2.0 mm, the semiconductor device becomes unnecessarily thick due to the thickness of the metal lid 2.
[0022]
Further, FIG. 2 shows a partially enlarged sectional view of the thick portion 2a. (A) is a groove having a U-shaped cross section formed on the side surface of the thick part 2a over the entire circumference, and (b) is a groove having a V-shaped cross section. In this way, it is possible to further prevent the brazing material from flowing out to the outer peripheral portion of the metal lid 2 by forming a groove on the side surface of the thick portion 2a. Further, the groove has a substantially V-shaped cross section, and the slope on the plate member 3 side (lower side) is inclined to the lower side so as to be parallel to the side surface of the thick portion 2a. A shape in which the inclined surface on the lid 2 side (upper side) is substantially perpendicular to the side surface of the thick portion 2a is preferable. In this case, wetting and spreading of the brazing material can be reliably prevented by the groove.
[0023]
Further, if the thickness of the plate member 3 is less than 0.1 mm, it tends to be impossible to sufficiently block the transmission of radiation. If the thickness exceeds 2 mm, the semiconductor device is unnecessarily thick due to the thickness of the plate member 3. It tends to become. Therefore, the thickness of the plate member 3 is preferably 0.1 to 2 mm.
[0024]
Furthermore, as shown in FIG. 2, the joining surface to which the plate member 3 of the thick portion 2 a is joined is preferably larger than the main surface of the plate member 3. In this case, it is possible to prevent the brazing material from creeping up on the side surface of the thick portion 2a by forming a meniscus of the brazing material on the outer peripheral portion of the joint surface. It is more preferable that the joining surface of the thick portion 2 a is larger than the main surface of the plate member 3 so that a brazed portion having a width of about 0.1 to 1.0 mm is formed around the plate member 3 over the entire circumference. If the thickness is less than 0.1 mm, the brazing material tends to crawl up to the side surface of the thick portion 2a. If the thickness exceeds 1.0 mm, the joining surface of the thick portion 2a becomes unnecessarily large. Is inappropriate.
[0025]
Further, Cu contained in the Cu—W composite material constituting the plate member 3 has a thermal expansion coefficient of Fe—Ni—Co alloy or Fe—Ni when the content is less than 5 wt%. It becomes extremely smaller than the thermal expansion coefficient of the metal lid 2 made of a metal such as an alloy. When it exceeds 30% by weight, the thermal expansion coefficient of the plate member 3 becomes extremely larger than the thermal expansion coefficient of the metal lid 2. In either case, when the plate member 3 is brazed to the metal lid 2, the metal lid 2 is greatly warped due to the difference in thermal expansion coefficient between the two, and the metal lid 2 Is difficult to weld to the metal frame 5 by the seam weld method. Therefore, the content of Cu contained in the Cu—W composite material constituting the plate member 3 is preferably 5 to 30% by weight.
[0026]
Further, the plate member 3 is formed by pressing W powder having a particle size of about 10 μm into a block shape by press molding at a pressure of about 98000000 N / m ² , and firing this at a temperature of about 2300 ° C. A sintered body is obtained, and thereafter, the molten portion is impregnated with Cu, which is heated and melted at a temperature of 1100 ° C., by utilizing capillary action in the porous portion of the W sintered body.
[0027]
In addition, in order to make the brazing of the plate member 3 and the metal lid 2 easy and strong on the brazing surface of the plate member 3, a Ni plating layer having a thickness of about 1 to 5 μm may be applied. preferable.
[0028]
In order to effectively prevent radiation from entering the upper surface of the semiconductor element 4, the area of the main surface of the plate member 3 is preferably larger than the area of the upper surface of the semiconductor element 4.
[0029]
Thus, in the semiconductor device of the present invention, the semiconductor element 4 is bonded and fixed to the bottom surface of the recess 1a of the insulating base 1 with an adhesive such as brazing material, glass, resin, etc., and each electrode of the semiconductor element 4 is bonded to the bonding wire 6. Then, the metal lid 2 is electrically connected to the metallized wiring layer 9 and then welded to the metal frame 5 brazed to the upper surface of the insulating base 1 by the seam weld method. A semiconductor device as a final product is obtained by airtightly housing the semiconductor element 4 in a container made of
[0030]
【Example】
Examples of the semiconductor device of the present invention will be described below.
[0031]
Example 1
The semiconductor device of the present invention shown in FIG. 1 was configured as follows.
[0032]
The semiconductor element 4 made of LSI was bonded and fixed to the bottom surface of the recess 1a of the insulating substrate 1 made of an aluminum oxide sintered body (alumina ceramic) via a resin adhesive. At this time, each electrode of the semiconductor element 4 is electrically connected to the metallized wiring layer 9 made of W and having a Ni plating layer having a thickness of 5 μm and an Au plating layer having a thickness of 1.2 μm sequentially deposited on the surface via bonding wires 6. The external lead terminals 7 made of Fe—Ni—Co alloy were brazed to the outer peripheral portion of the upper surface of the insulating base 1 of the metallized wiring layer 9 by Ag brazing. A ceramic frame 1b made of alumina ceramics was laminated around the recess 1a on the upper surface of the insulating substrate 1. A metal frame 5 made of Fe-Ni-Co alloy is brazed to the metallized metal layer 8 made of W on the upper surface of the ceramic frame 1b by Ag brazing, and a plate is formed on the upper surface of the metal frame 5 on the lower main surface. The metal lid 2 made of an Fe—Ni—Co alloy brazed to the member 3 was welded by a seam weld welding method.
[0033]
As the plate member 3, a W plate, a Cu plate, and a Cu-W composite material having various contents of Cu are prepared, and radiation (high energy secondary cosmic ray) is applied to the semiconductor device provided with them. Table 1 shows the results of evaluating the shielding properties and the bonding properties of the plate member 3 when the radiation corresponding to (γ rays) is irradiated from the outside. In the case of a W plate or a Cu plate, a flat plate is used, and in the case of a Cu-W composite material, the thickness other than the thick portion 2a is 1 mm and the thickness of the thick portion 2a is 1 mm. did. In Table 1, wt% means weight%.
[0034]
[Table 1]

[0035]
From Table 1, in the board member 3 which consists of Cu-W composite material whose Cu content is 5-30 wt%, the shielding property of radiation and bondability were favorable. As for the shielding property, the case where no malfunction occurred in the semiconductor element 4 due to the transmission of radiation was marked with ◯, and the case where malfunction occurred was marked with ×. As for the bonding property, these are deformed due to the difference between the thermal expansion coefficient of the metal lid 2 and the thermal expansion coefficient of the plate member 3, and the plate member 3 is peeled off at the joint between the metal lid 2 and the plate member 3. The case where no bonding failure occurred was marked with ◯, and the case where bonding failure occurred was marked with x.
[0036]
Regarding the shielding property, the W-plate and the Cu—W composite material having a Cu content of 40 wt% or less did not cause malfunction in the semiconductor element 4. This is because the shielding effect of the plate member 3 is maintained by setting the content of Cu with a small atomic weight relative to W with a large atomic weight to 40 wt% or less. Regarding the bondability, the Cu-W composite material having a Cu content of 5 to 30 wt% in the plate member 3 was good. Other than that, the thermal stress generated due to the difference between the thermal expansion coefficient of the plate member 3 and the thermal expansion coefficient of the metal lid 2 made of Fe—Ni—Co alloy is joined through the brazing material. 2 and the plate member 3 was applied to the joint portion, and the plate member 3 was peeled off from the joint portion.
[0037]
From the above results, it was found that the plate member 3 satisfying the shielding property and the bonding property is a Cu—W composite material having a Cu content of 5 to 30 wt%. The thermal expansion coefficient of the Fe—Ni—Co alloy during brazing (about 800 ° C.) is 6.2 × 10 ⁻⁶ / ° C., the thermal expansion coefficient of W is 5.0 × 10 ⁻⁶ / ° C., and the thermal expansion coefficient of Cu is 18.3 × 10 ^{− 6} / ° C.
[0038]
(Example 2)
Further, a plate member 3 made of a Cu-W composite material having a Cu content of 10% by weight, having a thickness other than the thick portion 2a of 1 mm and various heights of the thick portion 2a is provided. A semiconductor device was fabricated in the same manner as in Example 1. Table 2 shows the evaluation results of the flow of Ag brazing when the plate member 3 is brazed to the thick portion 2a with respect to these semiconductor devices. In these semiconductor devices, the joining surface to which the plate member 3 of the thick portion 2a is joined is larger than the main surface of the plate member 3 over the entire circumference by a width of 0.5 mm.
[0039]
[Table 2]

[0040]
From Table 2, the thickness of the thick part 2a is 0.3 mm or more. In the determination, a case where unnecessary Ag wax did not flow out to the outer peripheral portion of the metal lid 2 was marked as ◯, and a case where it was flowing out was marked as x. When the thickness of the thick part 2a was 0.1 mm or less, the Ag braze flowed out to the outer peripheral part of the metal lid 2 because the height of the thick part 2a was low. In this case, unnecessary Ag solder adhered to the outer peripheral portion of the metal lid 2, and the metal lid 2 could not be firmly welded to the metal frame 5. When the thickness exceeded 0.3 mm, the flow of Ag solder disappeared, but when it exceeded 2.0 mm, the semiconductor device became unnecessarily thick due to the thickness of the thick portion 2a. Thereby, it turned out that it is preferable that the height of the thick part 2a shall be 0.3-2.0 mm.
[0041]
Example 3
As shown in FIG. 2, on the side surface of the thick part 2a, the groove A, the V-shaped groove B, and the substantially V-shaped cross section are formed by the lower slope and the side of the thick part 2a. Three types of semiconductor devices in which a groove C having an angle of 20 ° and an angle between the upper slope and the side surface of the thick part 2a formed by 90 ° and a semiconductor device without a groove are the same as in the first embodiment. Ten of each were prepared. Table 3 shows the evaluation results of the flow of Ag brazing when the plate member 3 is brazed to the thick part 2a. In these semiconductor devices, the joining surface to which the plate member 3 of the thick portion 2a is joined is larger than the main surface of the plate member 3 over the entire circumference by a width of 0.5 mm.
[0042]
[Table 3]

[0043]
From Table 3, it was found that the groove C completely prevented the flow of Ag wax. In the determination, a case where there was no flow of Ag wax to the metal lid 2 other than the thick portion 2a was evaluated as ◯, and a case where there was a flow of Ag wax was evaluated as x. In contrast to the thick portion 2a having no groove, the grooves A, B and C have meniscuses formed at the corners of the grooves, effectively preventing the flow of Ag solder.
[0044]
It should be noted that the present invention is not limited to the above-described embodiments and examples, and various modifications may be made without departing from the scope of the present invention. For example, the grooves in FIG. 2 may have other shapes, and may be arc-shaped or U-shaped grooves. Further, for example, as shown in FIG. 3 as another example of the embodiment of the present invention, the plate member 3 may be joined to the upper main surface of the metal lid 2. In this case, radiation can be prevented from entering from the surface of the semiconductor element 4 in the same manner as when the plate member 3 is joined to the lower main surface of the metal lid 2. Further, the plate member 3 may be joined to the upper and lower main surfaces of the metal lid 2. Further, the plate member 3 can be bonded to the lower surface of the insulating base 1 to prevent the transmission of radiation from the back surface side.
[0045]
【The invention's effect】
A semiconductor device according to the present invention includes an insulating base having a recess formed on the upper surface, a semiconductor element placed on the bottom surface of the recess, a metal frame attached around the recess on the upper surface of the insulating base, and a metal frame. A metal lid body joined to the upper surface of the body and having a thick portion formed at the center of the upper main surface and / or the lower main surface, and a porous tungsten sintered body joined to the thick portion and By including a plate member impregnated with copper, a porous tungsten sintered body is impregnated with copper when the semiconductor device is incorporated into a communication satellite or the like and used in outer space where the influence of radiation is large. The plate member formed can prevent radiation from entering the semiconductor element, thereby suppressing the deterioration of the semiconductor device due to radiation and extending the life of the semiconductor device. In addition, the thick portion formed on the metal lid prevents the brazing material from flowing out to the outer periphery of the metal lid when the plate member is joined to the metal lid, so that the metal lid is made into the metal frame. It can be welded firmly.
[0046]
In the semiconductor device of the present invention, preferably, the metal lid is formed with grooves on the entire side surface of the thick portion, so that the brazing material is thick when the plate member is brazed to the thick portion. It is possible to prevent the side surface of the metal frame from getting wet and reaching the welded portion of the metal frame with the metal lid. As a result, the metal lid can be firmly welded to the metal frame.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of a semiconductor device of the present invention.
FIGS. 2A and 2B are main part enlarged sectional views showing examples of an embodiment of a thick part of a metal lid in a semiconductor device of the present invention, respectively.
FIG. 3 is a cross-sectional view showing another example of the embodiment of the semiconductor device of the present invention.
[Explanation of symbols]
1: Insulating substrate 1a: Recess 1b: Ceramic frame 2: Metal lid 2a: Thick part 3: Plate member 4: Semiconductor element 5: Metal frame

Claims

An insulating base having a recess formed on the top surface, a semiconductor element mounted on the bottom surface of the recess, a metal frame attached around the recess on the top surface of the insulating base, and an upper surface of the metal frame And a copper lid on the porous tungsten sintered body which is bonded to the thick part and has a thick part formed in the central part of the upper main surface and / or the lower main surface. A plate member formed by impregnation, and the metal lid body has a V -shaped groove formed on the side surface of the thick portion over the entire circumference, and the groove side of the groove is the metal lid body side. wherein a inner surface is turned vertically into and against the side surface of the thick portion of the.