JP4150285B2

JP4150285B2 - Mother board for electronic component mounting package

Info

Publication number: JP4150285B2
Application number: JP2003116400A
Authority: JP
Inventors: 日出和田丸; 明彦舟橋
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2003-04-21
Filing date: 2003-04-21
Publication date: 2008-09-17
Anticipated expiration: 2023-04-21
Also published as: JP2004327506A

Description

【０００１】
【発明の属する技術分野】
本発明は、配線基板上に半導体素子や圧電振動子等の電子部品を搭載するための電子部品搭載用パッケージを多数配列してなる電子部品搭載用パッケージ用母基板に関するものである。
【０００２】
【従来の技術】
従来、コンピュータ等の情報処理装置や携帯電話機等の通信端末装置等に実装される樹脂封止型の小型の電子装置として、例えば図５に断面図で示すものが知られている。
この電子装置は、酸化アルミニウム質焼結体等の電気絶縁材料から成る絶縁基板の側面に上下面間にわたる切欠き部４４を複数有するとともに、上面から切欠き部４４を介して下面にかけて導出された、タングステン（Ｗ）やモリブデン（Ｍｏ）等の金属粉末のメタライズ層から成る複数の配線層４５が形成された、大きさが数ｍｍ角程度の四角平板状の配線基板４１を有する。そして、配線基板４１上に半導体素子等の電子部品４２を、その各電極が対応する配線層４５に導体バンプ４６を介して電気的に接続されるようにして搭載するとともに、配線基板４１の上面中央部に電子部品４２を覆うようにして例えばエポキシ樹脂等の樹脂から成る樹脂封止材４３を固着させることにより、電子部品４２を気密に封止して成る電子装置が作製される。
【０００３】
しかしながら、この従来の電子装置では、電子部品４２を覆うようにして液状の樹脂封止材４３を滴下する際に、液状の樹脂封止材４３の一部がその流動性により切欠き部４４内に流れ込んでしまいやすい。そして、切欠き部４４内に樹脂封止材４３が流れ込むと、切欠き部４４内に被着された配線層４５を樹脂封止材４３が覆ってしまう。その結果、電子装置を外部電気回路基板に実装する際に、切欠き部４４内の配線層４５と外部電気回路基板の接続用導体との間に立体的な半田の溜まり（いわゆるメニスカス）が良好に形成されず、電子装置を外部電気回路基板に強固に実装することができなくなるという問題点があった。
【０００４】
そこで、本願出願人は、図３に断面図で示すような電子装置を提案した（下記の特許文献１参照）。すなわち、下層の絶縁層２１ｂの側面に上端が上層の絶縁層２１ａで塞がれた切欠き部２４を有するとともに、上面から内部および切欠き部２４の内面を介して下面に導出するＷやＭｏ等の金属粉末のメタライズ層から成る配線層２５が被着された配線基板２１を有し、その上面に、電子部品２２がその各電極と対応する配線層２５に導体バンプ２６を介して電気的に接続されるようにして搭載され、電子部品２２を覆うように樹脂封止材２３が固着された電子装置である。
【０００５】
この電子装置によれば、切欠き部２４の上端が上層の絶縁層２１ａで塞がれるため、樹脂封止材２３が切欠き部２４内に流れ込んで切欠き部２４内に被着させた配線層２５が樹脂封止材２３で覆われることは一切ない。その結果、電子装置を外部電気回路基板に実装する際に、切欠き部２４内の配線層２５と外部電気回路基板の接続用導体との間に半田の溜りが立体的に良好に形成されて、電子装置が外部電気回路基板に極めて強固に実装されるというものである。
【０００６】
なお、このような従来の電子装置は、その製造時における取り扱いを容易とするとともに製造効率を高いものとするために、図４に断面図で示すように、多数個の電子装置を縦横に一体的に配列形成して製造するように成した多数個取りの製造方法により製造される。
【０００７】
まず、配線基板２１となる多数の配線基板領域３１を仮想線で示した分割線３２で区切って縦横に一体的に配列形成するとともに、分割線３２上に、下層の絶縁層３０ｂを貫通して上端が上層の絶縁層３０ａで塞がれた切欠き部用の穴３３を形成し、各配線基板領域３１の上面から内部および穴３３の内面を介して下面に導出される複数の配線層２５を被着形成して成る母基板３０を準備する。次に、母基板３０の各配線基板領域３１上に電子部品２２をその各電極が対応する配線層２５に電気的に接続されるようにして搭載するとともに、母基板３０上の全ての配線基板領域３１の電子部品２２を覆うように液状の樹脂封止材３４をスクリーン印刷法により塗布する。その後、樹脂封止材３４を硬化させて固着させ、最後に母基板３０を分割線３２に沿って分割することによって多数個の電子装置が同時集約的に製造される。
【０００８】
また、母基板３０の複数の配線層２５は、その露出表面にニッケルめっき層および金めっき層等のめっき金属層が電解めっき法や無電解めっき法により被着されており、これにより、配線層２５の腐食を有効に防止することができる。
【０００９】
そして、分割して得られる電子装置の切欠き部２４内の配線層２５と外部電気回路基板の接続用導体との間に半田の溜りが立体的に良好に形成されて、電子装置を外部電気回路基板に極めて強固に実装させることができる。
【００１０】
【特許文献１】
特開２００１−３５６０６４号公報
【００１１】
【発明が解決しようとする課題】
しかしながら、上述の特許文献１の電子装置においては、母基板３０をめっき液中に浸漬して配線層２５の露出表面にニッケルめっき層および金めっき層等のめっき金属層を電解めっき法や無電解めっき法により被着させているが、その際、切欠き部用の穴３３は各配線基板領域３１を区切る分割線３２上にあるとともに上端が上層の絶縁層３０ａで塞がれていることから、穴３３の内面に被着形成された配線層２５の上端部では空気が抜けきれずに空気溜りが生じ易くなっており、そのため空気溜りの発生している配線層２５の上端部はめっき液中に浸れなくなる。その結果、電子装置の切欠き部２４内の配線層２５の腐食を防ぐことができなくなり、腐食により半田の流れ性が低下するとともに半田の接合力も低下するため、切欠き部２４内の配線層２５と外部電気回路基板の接続用導体との間に半田のメニスカスを良好に形成することができなくなる。すると、電子装置を外部電気回路基板に強固に実装させることができないという問題点が生じていた。
【００１２】
したがって、本発明はかかる従来の問題点に鑑み完成されたものであり、その目的は、配線基板の切欠き部内の配線層にめっき金属層を良好に被着させることにより配線層を外部電気回路に確実かつ強固に接続させることができる電子部品搭載用パッケージおよび電子装置を提供することにある。
【００１３】
【課題を解決するための手段】
本発明の電子部品搭載用パッケージ用母基板は、電子部品が搭載される搭載部および前記電子部品の電極が接続される配線層が形成された配線基板領域が、多数配列された母基板と、前記母基板の下面且つ隣接しあう前記配線基板領域の分割線上に形成された切欠き部用の非貫通の穴と、該穴の内面に形成され、前記配線層と電気的に接続された側面導体層とを備え、前記分割線に沿って前記母基板を分割することにより前記配線基板領域を有する多数の電子部品搭載用パッケージを得るための電子部品搭載用パッケージ用母基板であって、前記側面導体層は、前記穴の下端から上側に向けて途中まで形成されており、該側面導体層の表面には、めっき金属層が形成されていることを特徴とする。
【００１４】
本発明の電子部品搭載用パッケージ用母基板は、切欠き部用の穴の内面にめっき金属層を被着させる際に、空気溜りが発生しやすい切欠き部用の穴の上端部には側面導体層が被着されていないため、側面導体層の上端部にめっき金属層が形成されずに腐食されるのを有効に防止できる。
【００１５】
【発明の実施の形態】
本発明について以下に詳細に説明する。図１は本発明の電子部品搭載用パッケージ用母基板を用いて作製した電子部品搭載用パッケージ（以下、パッケージともいう）について実施の形態の一例を示す断面図であり、図１において、１は配線基板、２はＩＣ，ＬＳＩ等の半導体素子などから成る電子部品、３は樹脂封止材である。
【００１６】
パッケージは、配線基板１の主面に電子部品２が搭載される搭載部７および電子部品２の電極が接続される配線層５が形成されているとともに、配線基板１の角部および側面の少なくとも一方に、配線基板１の下面から上面に向けて形成された切欠き部４に配線層５と電気的に接続された側面導体層５ａが形成されているものであって、切欠き部４は、配線基板１の下面から上面に向けて途中まで形成されているとともに、側面導体層５ａは、切欠き部４の下端から上側に向けて途中まで形成されている。
【００１７】
配線基板１は、酸化アルミニウム質焼結体や窒化アルミニウム質焼結体，ムライト質焼結体，窒化珪素質焼結体，炭化珪素質焼結体，ガラスセラミックス等の電気絶縁材料から成り、例えば上層の絶縁層１ａ，中間層の絶縁層１ｂおよび下層の絶縁層１ｃが積層された四角平板状である。そして、絶縁層１ｂ，１ｃの側面には、上端が絶縁層１ａで塞がれた複数の切欠き部４が形成されている。
【００１８】
この配線基板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で、以下、グリーンシートともいう）を得、しかる後、グリーンシートに切欠き部４となる貫通孔を打ち抜き加工で形成するとともに、電子部品２を搭載するための絶縁層１ａ〜１ｃ用の各グリーンシートを積層し、高温（約１６００℃）で焼成し一体化することで形成される。
【００１９】
また、配線基板１は、電子部品２を支持するものであるとともに、絶縁層１ａの上面から内部および切欠き部４内に被着された側面導体層５ａを介して絶縁層１ｃの下面にかけて被着された複数の配線層５が形成されている。この配線層５は、電子部品２の各電極を外部電気回路に接続するための導電路として機能し、配線基板１の上面の配線層５には電子部品２の各電極が例えば半田や金等から成る導体バンプ６を介して電気的に接続される。
【００２０】
なお、図１の例では、電子部品２はその下面に電極を有するとともに各電極と配線層５とが導体バンプ６を介して電気的に接続されているが、電子部品２はその上面に電極を有するとともに各電極がボンディングワイヤ等を介して配線層５に電気的に接続されていてもよい。
【００２１】
配線層５および側面導体５ａは、例えばＷやＭｏ等の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、配線基板１となるグリーンシートに予め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、絶縁層１ａ〜１ｃのそれぞれの所定位置に被着形成されている。
【００２２】
なお、配線層５および側面導体５ａの露出する表面に、ニッケル（Ｎｉ），金（Ａｕ）等の耐蝕性に優れる金属を１〜２０μｍ程度の厚みで被着させておくのがよく、配線層５および側面導体層５ａが酸化腐蝕するのを有効に防止できるとともに、配線層５と電子部品２との固着、側面導体層５ａと外部電気回路基板の接続用導体との接続を強固にすることができる。従って、配線層５および側面導体層５ａの露出表面には、厚さ１〜１０μｍ程度のＮｉめっき層と厚さ０．１〜３μｍ程度のＡｕめっき層が、電解めっき法や無電解めっき法により順次被着されていることが好ましい。
【００２３】
また、配線基板１の上面には、電子部品２を覆うようにして配線基板１の上面の全面に、エポキシ樹脂等の樹脂から成る樹脂封止材３が固着される。
樹脂封止材３は、配線基板１上に電子部品２を覆うようにして固着されることにより電子部品２を気密に封止して外部環境から保護する保護部材として機能する。
【００２４】
パッケージは、図２の断面図に示すように、その製造時における取り扱いを容易とするとともに製造効率を高いものとするために、多数個のパッケージを縦横に一体的に配列形成した多数個取り配線基板である電子部品搭載用パッケージ用母基板として製作される。
【００２５】
多数個取り用の母基板１０は、酸化アルミニウム質焼結体や窒化アルミニウム質焼結体，ムライト質焼結体，窒化珪素質焼結体，炭化珪素質焼結体，ガラスセラミックス等の電気絶縁材料から成る、上層の絶縁層１０ａ，中間層の絶縁層１０ｂおよび下層の絶縁層１０ｃを積層して成る。また母基板１０は、その中央部に各々が配線基板１となる多数の配線基板領域１１が仮想線である分割線１２で区切って縦横に配列形成されるとともに、分割線１２上に絶縁層１０ｂ，１０ｃを貫通して上端が絶縁層１０ａで塞がれた切欠き部用の穴１３が形成されている。また、各配線基板領域１１の上面から内部および穴１３の内面に被着された側面導体層５ａを介して下面に導出されるメタライズ層から成る配線層５が被着形成されている。
【００２６】
この母基板１０は、絶縁層１０ａ〜１０ｃが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，酸化カルシウム，酸化マグネシウム等の原料粉末に適当な有機バインダおよび溶剤を添加混合して泥漿状と成し、これを従来周知のドクタブレード法によりシート状に形成して３枚のグリーンシートを得て、しかる後、これらのグリーンシートに適当な打ち抜き加工および配線層５，側面導体層５ａ用のＷやＭｏ等の金属粉末を含む金属ペーストの塗布印刷を施すとともに上下に積層し、これを還元雰囲気中で約１６００℃の温度で焼成することによって製作される。
【００２７】
なお、母基板１０の配線層５および側面導体層５ａには、その露出表面にニッケルめっき層および金めっき層等のめっき金属層を電解めっき法や無電解めっき法により被着させておく。
【００２８】
そして、母基板１０の各配線基板領域１１上面に電子部品２を搭載するとともにその各電極を例えば半田や金から成る導体バンプ６を介して対応する配線層５に電気的に接続する。電子部品２の各電極を導体バンプ６を介して配線層５に電気的に接続させるには、例えば、電子部品２の各電極に導体バンプ６を予め取着させておき、この導体バンプ６を対応する配線層５に溶着や圧着等により接合する方法が採用される。
【００２９】
そして、母基板１０上の全配線基板領域１１にわたり各配線基板領域１１およびこれに搭載された各電子部品２を覆うようにして、例えばエポキシ樹脂やポリイミド樹脂，フェノール樹脂，ビスマレイミドトリアジン樹脂等の熱硬化性樹脂から成る液状の樹脂封止材１４を塗布し、硬化させる。
【００３０】
なお、母基板１０上に液状の樹脂封止材１４を塗布するには、一定量ずつ吐出可能なノズルを母基板１０上に配置し、このノズルを水平方向に移動させながらノズルから一定量の液状の樹脂封止材１４を吐出させる方法、または液状の樹脂封止材１４をスクリーン印刷法により母基板１０上に塗布する方法等が採用される。このとき、側面導体層５ａが被着された穴１３はその上端が絶縁層１０ａで塞がれていることから、母基板１０上に塗布した樹脂封止材１４が穴１３内に流れ込むことは一切ない。同時に、樹脂封止材１４を母基板１０上の全配線基板領域１１にわたり塗布することから、樹脂封止材１４を各配線基板領域１１上にまとめて塗布することができ、その結果、樹脂封止材１４の塗布の作業性が極めて簡易になる。また、母基板１０上に塗布した樹脂封止材１４を硬化させるには、例えば熱硬化法や紫外線硬化法により硬化させる方法が採用される。
【００３１】
そして、最後に、母基板１０および樹脂封止材１４をダイアモンドカッターやレーザカッターを用いて分割線１２に沿って分割することにより、中間層の絶縁層１ｂおよび下層の絶縁層１ｃの側面に、上端が上層の絶縁層１ａで塞がれた切欠き部４が形成される。
また、上面から内部および切欠き部４内の側面導体層５ａを介して下面に導出される配線層５が被着された配線基板１の上面に、電子部品２がその各電極と対応する配線層５に導体バンプ６を介して電気的に接続されるようにして搭載され、配線基板１の上面に電子部品２を覆うようにして樹脂封止材３が固着された電子装置が多数個同時集約的に製作される。
【００３２】
本発明において、切欠き部４の上端部には側面導体層５ａが形成されていない非形成部が設けられているが、その非形成部の上下方向の長さは０．０５〜０．５ｍｍが好ましい。０．０５ｍｍ未満では、非形成部の長さが短いため、母基板１０の切欠き部用の穴１３の内面にめっき金属層を被着させる際に非形成部に空気溜りが発生すると、側面導体層５ａの一部を空気溜りが覆ってしまい、側面導体層５ａの一部にめっき金属層が被着されない事態が生じ易い。０．５ｍｍを超えると、非形成部の長さが長くなるため、空気溜りが側面導体５ａの一部を覆うことは無く良好にめっき金属層を被着できるものの、配線基板１の厚みが厚くなり薄型化に不利となる。
【００３３】
かくして、パッケージは、配線基板１の主面に電子部品２が搭載される搭載部７および電子部品２の電極が接続される配線層５が形成されているとともに、配線基板１の角部および側面の少なくとも一方に、配線基板１の下面から上面に向けて形成された切欠き部４に配線層５と電気的に接続された側面導体層５ａが形成されているものであって、切欠き部４は、配線基板１の下面から上面に向けて途中まで形成されているとともに、側面導体層５ａは、切欠き部４下端から上側に向けて下層の絶縁層１ｃ上面の位置まで形成されていることから、母基板１０の切欠き部用の穴１３の内面にめっき金属層を被着させる際に、空気溜りが発生しやすい穴１３の上端部に相当する中間層の絶縁層１ｂの側面には側面導体層５ａが被着されていないため、側面導体層５ａが腐食されるのを有効に防止できるとともに、切欠き部４内の側面導体層５ａと外部電気回路基板の接続用導体との間に半田のメニスカスが良好に形成されて、外部電気回路基板に極めて強固に実装させることができる。
【００３４】
また、電子装置は、上記のパッケージと、搭載部７に搭載されるとともに配線層５に電気的に接続された電子部品２と、電子部品２を覆う樹脂封止材３とを具備したことにより、切欠き部４内の側面導体層５ａと外部電気回路基板の接続用導体との間に半田のメニスカスが良好に形成されて電子装置が外部電気回路基板に極めて強固に実装される信頼性の高いものとなる。
【００３５】
なお、本発明は上述の実施の形態の一例に限定されるものではなく、本発明の要旨を逸脱しない範囲であれば種々の変更は可能である。
【００３６】
【発明の効果】
本発明の電子部品搭載用パッケージ用母基板は、切欠き部用の穴の内面にめっき金属層を被着させる際に、空気溜りが発生しやすい切欠き部用の穴の上端部には側面導体層が被着されていないため、側面導体層の上端部にめっき金属層が形成されずに腐食されるのを有効に防止できる。
【図面の簡単な説明】
【図１】本発明の電子部品搭載用パッケージ用母基板を用いて作製した電子部品搭載用パッケージについて実施の形態の一例を示す断面図である。
【図２】本発明の電子部品搭載用パッケージ用母基板について実施の形態の一例を示す断面図である。
【図３】従来の電子部品搭載用パッケージの断面図である。
【図４】図３の電子部品搭載用パッケージを母基板から多数個取りによって製造する製造方法を説明するための母基板の断面図である。
【図５】従来の電子部品搭載用パッケージの他の例を示す断面図である。
【符号の説明】
１：配線基板
２：電子部品
３：樹脂封止材
５：配線層
５ａ：側面導体層
１０：母基板
１１：配線基板領域
１２：分割線
１３：切欠き部用の穴[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic component comprising a mounting package and arrayed electronic component mounting package for the mother board for mounting electronic components such as semiconductor devices and piezoelectric vibrator on the wiring board.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a resin-sealed small electronic device mounted on an information processing device such as a computer or a communication terminal device such as a mobile phone, for example, a cross-sectional view shown in FIG. 5 is known.
This electronic device has a plurality of notches 44 extending between the upper and lower surfaces on the side surface of an insulating substrate made of an electrically insulating material such as an aluminum oxide sintered body, and is led out from the upper surface to the lower surface via the notches 44. In addition, a wiring board 41 having a square plate shape with a size of several square mm is formed, on which a plurality of wiring layers 45 made of a metallized layer of a metal powder such as tungsten (W) or molybdenum (Mo) are formed. Then, an electronic component 42 such as a semiconductor element is mounted on the wiring board 41 so that each electrode thereof is electrically connected to the corresponding wiring layer 45 via the conductor bump 46, and the upper surface of the wiring board 41. An electronic device in which the electronic component 42 is hermetically sealed is manufactured by fixing a resin sealing material 43 made of a resin such as an epoxy resin so as to cover the electronic component 42 at the center.
[0003]
However, in this conventional electronic device, when the liquid resin sealing material 43 is dropped so as to cover the electronic component 42, a part of the liquid resin sealing material 43 is in the notch 44 due to its fluidity. It is easy to flow into. When the resin sealing material 43 flows into the notch 44, the resin sealing material 43 covers the wiring layer 45 deposited in the notch 44. As a result, when the electronic device is mounted on the external electric circuit board, a three-dimensional solder pool (so-called meniscus) is good between the wiring layer 45 in the notch 44 and the connection conductor of the external electric circuit board. In other words, the electronic device cannot be firmly mounted on the external electric circuit board.
[0004]
Therefore, the applicant of the present application has proposed an electronic device as shown in a sectional view in FIG. 3 (see Patent Document 1 below). That is, the side surface of the lower insulating layer 21b has a notch portion 24 whose upper end is closed by the upper insulating layer 21a, and W or Mo led out from the upper surface to the lower surface through the inside and the inner surface of the notch portion 24. A wiring substrate 25 having a metal layer made of a metal powder such as a metal layer is attached, and an electronic component 22 is electrically connected to the wiring layer 25 corresponding to each electrode via conductor bumps 26 on the upper surface thereof. The electronic device is mounted so as to be connected to the resin, and the resin sealing material 23 is fixed so as to cover the electronic component 22.
[0005]
According to this electronic device, since the upper end of the notch 24 is blocked by the upper insulating layer 21a, the resin sealing material 23 flows into the notch 24 and is deposited in the notch 24. The layer 25 is never covered with the resin sealing material 23. As a result, when the electronic device is mounted on the external electric circuit board, the solder pool is three-dimensionally favorably formed between the wiring layer 25 in the notch 24 and the connection conductor of the external electric circuit board. The electronic device is mounted very firmly on the external electric circuit board.
[0006]
Such a conventional electronic device has a large number of electronic devices integrated vertically and horizontally as shown in a cross-sectional view in FIG. 4 in order to facilitate handling during manufacture and to increase manufacturing efficiency. It is manufactured by a multi-cavity manufacturing method that is configured to be manufactured in an array.
[0007]
First, a large number of wiring board regions 31 to be the wiring board 21 are divided by dividing lines 32 indicated by imaginary lines and integrally formed vertically and horizontally, and the lower insulating layer 30b is penetrated on the dividing lines 32. A plurality of wiring layers 25 led out from the upper surface of each wiring board region 31 to the inner surface and the inner surface of the hole 33 to the lower surface are formed by forming a notch hole 33 whose upper end is blocked by the upper insulating layer 30a. A mother substrate 30 formed by depositing is prepared. Next, the electronic component 22 is mounted on each wiring board region 31 of the mother board 30 so that each electrode is electrically connected to the corresponding wiring layer 25, and all the wiring boards on the mother board 30 are mounted. A liquid resin sealing material 34 is applied by screen printing so as to cover the electronic component 22 in the region 31. Thereafter, the resin sealing material 34 is cured and fixed, and finally, the mother board 30 is divided along the dividing lines 32, whereby a large number of electronic devices are manufactured simultaneously and collectively.
[0008]
In addition, the plurality of wiring layers 25 of the mother board 30 have plating metal layers such as a nickel plating layer and a gold plating layer deposited on the exposed surfaces thereof by an electrolytic plating method or an electroless plating method. 25 corrosion can be effectively prevented.
[0009]
A solder pool is formed in a three-dimensionally good manner between the wiring layer 25 in the notch 24 of the electronic device obtained by the division and the connection conductor of the external electric circuit board, and the electronic device is connected to the external electric device. It can be mounted very firmly on the circuit board.
[0010]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-356064
[Problems to be solved by the invention]
However, in the electronic device disclosed in Patent Document 1 described above, the base substrate 30 is immersed in a plating solution, and a plating metal layer such as a nickel plating layer and a gold plating layer is applied to the exposed surface of the wiring layer 25 by an electrolytic plating method or electroless method. In this case, the hole 33 for the notch is on the dividing line 32 that divides each wiring board region 31 and the upper end is blocked by the upper insulating layer 30a. In the upper end portion of the wiring layer 25 deposited on the inner surface of the hole 33, air cannot escape and air is easily trapped. Therefore, the upper end portion of the wiring layer 25 where the air pool is generated is the plating solution. Cannot soak inside. As a result, the corrosion of the wiring layer 25 in the cutout 24 of the electronic device cannot be prevented, and the flowability of the solder and the bonding strength of the solder are also reduced due to the corrosion. It becomes impossible to satisfactorily form a solder meniscus between 25 and the connecting conductor of the external electric circuit board. As a result, the electronic device cannot be firmly mounted on the external electric circuit board.
[0012]
Accordingly, the present invention has been completed in view of such conventional problems, and the object thereof is to satisfactorily attach a plated metal layer to a wiring layer in a notch portion of a wiring board so that the wiring layer is connected to an external electric circuit. Another object of the present invention is to provide an electronic component mounting package and an electronic device that can be securely and firmly connected to each other.
[0013]
[Means for Solving the Problems]
The electronic component mounting package mother board of the present invention includes a mother board in which a plurality of wiring board regions in which a wiring part to which an electronic component is mounted and a wiring layer to which an electrode of the electronic component is connected are formed are arranged; A non-penetrating hole for a notch formed in the lower surface of the mother board and on the dividing line of the wiring board region adjacent thereto, and a side surface formed in the inner surface of the hole and electrically connected to the wiring layer An electronic component mounting package mother board for obtaining a large number of electronic component mounting packages having the wiring board region by dividing the mother board along the dividing line. The side conductor layer is formed halfway from the lower end of the hole toward the upper side, and a plated metal layer is formed on the surface of the side conductor layer.
[0014]
In the electronic component mounting package mother board of the present invention, when the plated metal layer is deposited on the inner surface of the notch hole, the upper surface of the notch hole is liable to generate a side surface. Since the conductor layer is not deposited, it is possible to effectively prevent corrosion without forming the plated metal layer on the upper end portion of the side conductor layer.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below. FIG. 1 is a cross-sectional view showing an example of an embodiment of an electronic component mounting package (hereinafter also referred to as a package) manufactured using the electronic component mounting package mother board of the present invention . A wiring board, 2 is an electronic component made of a semiconductor element such as an IC or LSI, and 3 is a resin sealing material.
[0016]
The package includes a mounting portion 7 on which the electronic component 2 is mounted on the main surface of the wiring substrate 1 and a wiring layer 5 to which the electrodes of the electronic component 2 are connected, and at least corners and side surfaces of the wiring substrate 1. On the other hand, a side conductor layer 5a electrically connected to the wiring layer 5 is formed in a notch 4 formed from the lower surface to the upper surface of the wiring board 1, and the notch 4 The wiring board 1 is formed halfway from the lower surface toward the upper surface, and the side conductor layer 5a is formed halfway from the lower end of the cutout portion 4 toward the upper side.
[0017]
The wiring board 1 is made of an electrically insulating material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon nitride sintered body, a silicon carbide sintered body, or a glass ceramic. The upper insulating layer 1a, the intermediate insulating layer 1b, and the lower insulating layer 1c are in the form of a square plate. A plurality of notches 4 whose upper ends are closed by the insulating layer 1a are formed on the side surfaces of the insulating layers 1b and 1c.
[0018]
When this wiring board 1 is made of, for example, an aluminum oxide sintered body, a suitable 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. This is formed into a sheet shape by a conventionally known doctor blade method, calendar roll method or the like to obtain a ceramic green sheet (ceramic raw sheet, hereinafter also referred to as a green sheet), and then the notch 4 is formed on the green sheet. The through-holes to be formed are formed by punching, and the green sheets for the insulating layers 1a to 1c for mounting the electronic component 2 are laminated, fired at a high temperature (about 1600 ° C.), and integrated. .
[0019]
The wiring board 1 supports the electronic component 2 and covers the insulating layer 1a from the upper surface to the lower surface of the insulating layer 1c via the side conductor layer 5a attached to the inside and the notch 4. A plurality of attached wiring layers 5 are formed. The wiring layer 5 functions as a conductive path for connecting each electrode of the electronic component 2 to an external electric circuit, and each electrode of the electronic component 2 is, for example, solder, gold or the like on the wiring layer 5 on the upper surface of the wiring substrate 1. It is electrically connected through a conductor bump 6 made of
[0020]
In the example of FIG. 1, the electronic component 2 has electrodes on its lower surface and each electrode and the wiring layer 5 are electrically connected via the conductor bumps 6, but the electronic component 2 has electrodes on its upper surface. Each electrode may be electrically connected to the wiring layer 5 through a bonding wire or the like.
[0021]
For the wiring layer 5 and the side conductor 5a, for example, a metal paste obtained by adding and mixing a suitable organic solvent and solvent to a metal powder such as W or Mo is preliminarily patterned in a green sheet to be the wiring substrate 1 by screen printing. In this way, the insulating layers 1a to 1c are deposited on the respective predetermined positions by printing.
[0022]
It should be noted that a metal having excellent corrosion resistance, such as nickel (Ni), gold (Au), or the like is preferably deposited on the exposed surfaces of the wiring layer 5 and the side conductor 5a in a thickness of about 1 to 20 μm. 5 and the side conductor layer 5a can be effectively prevented from being oxidized and corroded, and the connection between the wiring layer 5 and the electronic component 2 and the connection between the side conductor layer 5a and the connection conductor of the external electric circuit board can be strengthened. Can do. Therefore, on the exposed surfaces of the wiring layer 5 and the side conductor layer 5a, an Ni plating layer having a thickness of about 1 to 10 μm and an Au plating layer having a thickness of about 0.1 to 3 μm are formed by an electrolytic plating method or an electroless plating method. It is preferred that they are deposited sequentially.
[0023]
A resin sealing material 3 made of a resin such as an epoxy resin is fixed to the upper surface of the wiring board 1 so as to cover the electronic component 2 over the entire upper surface of the wiring board 1.
The resin sealing material 3 functions as a protective member that hermetically seals the electronic component 2 and protects it from the external environment by being fixed on the wiring board 1 so as to cover the electronic component 2.
[0024]
As shown in the cross-sectional view of FIG. 2, the package is a multi-piece wiring in which a large number of packages are integrally arranged vertically and horizontally in order to facilitate handling during manufacturing and to increase manufacturing efficiency. It is manufactured as a mother board for an electronic component mounting package which is a board.
[0025]
A large number of mother substrates 10 are used for electrical insulation of aluminum oxide sintered bodies, aluminum nitride sintered bodies, mullite sintered bodies, silicon nitride sintered bodies, silicon carbide sintered bodies, glass ceramics, and the like. The upper insulating layer 10a, the intermediate insulating layer 10b, and the lower insulating layer 10c made of materials are laminated. In addition, the mother board 10 has a plurality of wiring board regions 11, each of which becomes the wiring board 1, at the central portion thereof, which are divided by vertical dividing lines 12 and arranged vertically and horizontally, and an insulating layer 10 b on the dividing lines 12. , 10c and a hole 13 for a notch whose upper end is blocked by an insulating layer 10a is formed. In addition, a wiring layer 5 made of a metallized layer led out from the upper surface of each wiring board region 11 to the lower surface through a side conductor layer 5a attached to the inside and the inner surface of the hole 13 is deposited.
[0026]
When the insulating layers 10a to 10c are made of an aluminum oxide sintered body, the mother substrate 10 is prepared by adding a suitable organic binder and solvent to a raw material powder such as aluminum oxide, silicon oxide, calcium oxide, magnesium oxide and the like. This is formed into a sheet shape by a conventionally known doctor blade method to obtain three green sheets. Thereafter, these green sheets are appropriately punched and wiring layers 5, side conductor layers 5a. It is manufactured by applying and printing a metal paste containing a metal powder such as W or Mo for use and laminating it up and down and firing it at a temperature of about 1600 ° C. in a reducing atmosphere.
[0027]
It should be noted that a plating metal layer such as a nickel plating layer and a gold plating layer is applied to the exposed surface of the wiring layer 5 and the side conductor layer 5a of the mother substrate 10 by an electrolytic plating method or an electroless plating method.
[0028]
Then, the electronic component 2 is mounted on the upper surface of each wiring board region 11 of the mother board 10 and each electrode thereof is electrically connected to the corresponding wiring layer 5 through a conductor bump 6 made of, for example, solder or gold. In order to electrically connect each electrode of the electronic component 2 to the wiring layer 5 via the conductor bump 6, for example, the conductor bump 6 is attached in advance to each electrode of the electronic component 2, and the conductor bump 6 is attached to the electrode 5. A method of joining to the corresponding wiring layer 5 by welding or pressure bonding is employed.
[0029]
The wiring board regions 11 and the electronic components 2 mounted on the wiring board regions 11 on the mother board 10 are covered so as to cover, for example, epoxy resin, polyimide resin, phenol resin, bismaleimide triazine resin, etc. A liquid resin sealing material 14 made of a thermosetting resin is applied and cured.
[0030]
In order to apply the liquid resin sealing material 14 on the mother substrate 10, a nozzle capable of discharging a certain amount is arranged on the mother substrate 10, and a certain amount of nozzle is moved from the nozzle while moving the nozzle in the horizontal direction. A method of discharging the liquid resin sealing material 14 or a method of applying the liquid resin sealing material 14 onto the mother substrate 10 by a screen printing method is employed. At this time, since the upper end of the hole 13 to which the side conductor layer 5a is deposited is closed by the insulating layer 10a, the resin sealing material 14 applied on the mother substrate 10 does not flow into the hole 13. Nothing at all. At the same time, since the resin sealing material 14 is applied over the entire wiring substrate region 11 on the mother substrate 10, the resin sealing material 14 can be applied collectively on each wiring substrate region 11, and as a result, the resin sealing The workability of applying the stopper 14 is extremely simple. Moreover, in order to harden the resin sealing material 14 apply | coated on the motherboard 10, the method of hardening by the thermosetting method or the ultraviolet curing method is employ | adopted, for example.
[0031]
Finally, by dividing the mother substrate 10 and the resin sealing material 14 along the dividing line 12 using a diamond cutter or a laser cutter, the side surfaces of the intermediate insulating layer 1b and the lower insulating layer 1c are A cutout portion 4 whose upper end is blocked by the upper insulating layer 1a is formed.
Further, on the upper surface of the wiring board 1 to which the wiring layer 5 led out from the upper surface to the lower surface through the side conductor layers 5a inside and in the notch portion 4 is attached, the electronic component 2 has wiring corresponding to each electrode. A large number of electronic devices mounted on the layer 5 so as to be electrically connected via the conductor bumps 6 and having the resin sealing material 3 fixed on the upper surface of the wiring board 1 so as to cover the electronic component 2 are simultaneously provided. Made intensively.
[0032]
In the present invention, the upper end portion of the cutout portion 4 is provided with a non-formed portion where the side conductor layer 5a is not formed, and the length in the vertical direction of the non-formed portion is 0.05 to 0.5 mm. Is preferred. If it is less than 0.05 mm, the length of the non-formed part is short, and therefore when the plated metal layer is deposited on the inner surface of the hole 13 for the notch part of the mother substrate 10, The air reservoir covers a part of the conductor layer 5a, and a situation in which the plated metal layer is not deposited on a part of the side conductor layer 5a easily occurs. If the thickness exceeds 0.5 mm, the length of the non-formed portion becomes long, so that the air reservoir does not cover a part of the side conductor 5a and the plated metal layer can be satisfactorily deposited, but the thickness of the wiring board 1 is thick. This is disadvantageous for thinning.
[0033]
Thus, in the package , the mounting portion 7 on which the electronic component 2 is mounted and the wiring layer 5 to which the electrode of the electronic component 2 is connected are formed on the main surface of the wiring substrate 1, and the corners and side surfaces of the wiring substrate 1 are formed. A side conductor layer 5a electrically connected to the wiring layer 5 is formed in at least one of the cutout portion 4 formed from the lower surface to the upper surface of the wiring board 1, and the cutout portion 4 is formed partway from the lower surface to the upper surface of the wiring board 1, and the side conductor layer 5a is formed from the lower end of the notch 4 toward the upper surface to the position of the upper surface of the lower insulating layer 1c. Therefore, when the plating metal layer is deposited on the inner surface of the hole 13 for the notch portion of the mother substrate 10, the side surface of the insulating layer 1b of the intermediate layer corresponding to the upper end portion of the hole 13 where air retention is likely to occur is formed. The side conductor layer 5a is not deposited Therefore, the side conductor layer 5a can be effectively prevented from being corroded, and a solder meniscus is well formed between the side conductor layer 5a in the notch 4 and the connection conductor of the external electric circuit board. It can be mounted very firmly on the external electric circuit board.
[0034]
In addition, the electronic device includes the above package , the electronic component 2 mounted on the mounting portion 7 and electrically connected to the wiring layer 5, and the resin sealing material 3 covering the electronic component 2. The solder meniscus is satisfactorily formed between the side conductor layer 5a in the notch 4 and the connection conductor of the external electric circuit board, and the electronic device is mounted on the external electric circuit board very firmly. It will be expensive.
[0035]
Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.
[0036]
【The invention's effect】
In the electronic component mounting package mother board of the present invention, when the plated metal layer is deposited on the inner surface of the notch hole, the upper surface of the notch hole is liable to generate a side surface. Since the conductor layer is not deposited, it is possible to effectively prevent corrosion without forming the plated metal layer on the upper end portion of the side conductor layer.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of an electronic component mounting package manufactured using the electronic component mounting package mother board of the present invention.
FIG. 2 is a cross-sectional view showing an example of an embodiment of an electronic component mounting package mother board according to the present invention .
FIG. 3 is a cross-sectional view of a conventional electronic component mounting package.
4 is a cross-sectional view of a mother board for explaining a manufacturing method for manufacturing a large number of electronic component mounting packages of FIG. 3 from the mother board.
FIG. 5 is a cross-sectional view showing another example of a conventional electronic component mounting package.
[Explanation of symbols]
1: Wiring board 2: Electronic component 3: Resin encapsulant 5: Wiring layer 5a: Side conductor layer 10: Mother board 11: Wiring board area 12: Dividing line 13: Hole for notch

Claims

A mother board in which a plurality of wiring board regions in which a mounting portion on which electronic parts are mounted and a wiring layer to which electrodes of the electronic parts are connected are formed are arranged;
A non-through hole for a notch formed on the lower surface of the mother board and on the dividing line of the wiring board region adjacent to each other;
A side conductor layer formed on the inner surface of the hole and electrically connected to the wiring layer ;
An electronic component mounting package mother board for obtaining a large number of electronic component mounting packages having the wiring board region by dividing the mother board along the dividing line ,
The side conductor layer is formed partway from the lower end of the hole toward the upper side,
An electronic component mounting package mother board, wherein a plated metal layer is formed on a surface of the side conductor layer.