JP2004253711A

JP2004253711A - Package for housing light emitting element and light emitting device

Info

Publication number: JP2004253711A
Application number: JP2003044398A
Authority: JP
Inventors: Yoshinori Maekawa; 義紀前川; Toshiyuki Chitose; 敏幸千歳; Yosuke Moriyama; 陽介森山
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2003-02-21
Filing date: 2003-02-21
Publication date: 2004-09-09

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for housing a light emitting element which can be mounted highly reliably on the wiring conductor of an external electric circuit board without causing any positional deviation nor being inclined with high joint strength and is high in working efficiency and, in addition, on which a plurality of light emitting elements can be mounted so that the elements may make full-color light emission. <P>SOLUTION: This package for housing light emitting element is constituted by laminating a frame body 2 having through holes surrounding a plurality of mounting sections 1a upon the upper surface of a belt-like substrate 1 on which the plurality of mounting sections 1a is formed in a row for mounting light emitting elements 3. The substrate 1 has notched sections 7 formed by notching its four corners from the upper surface to the lower surface of the substrate 1, and having arcuate shapes in the top view under the frame body 2 and side-face conductors formed on the inner peripheral surfaces of the notched sections 7. The electrodes of the light emitting elements 3 mounted on the mounting sections 1a are electrically connected to the side-face conductors. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、発光ダイオード等の発光素子を用いた表示装置等に用いられる、発光素子を収納するための発光素子収納用パッケージおよび発光装置に関する。
【０００２】
【従来の技術】
従来、発光ダイオード等の発光素子を収容するための発光素子収納用パッケージ（以下、単にパッケージともいう）として、セラミック製のパッケージが用いられている。従来のセラミック製のパッケージは、図７のパッケージの断面図に示すように、上面の中央部に発光素子２３を搭載するための導体層から成る搭載部２１ａを有し、搭載部２１ａおよびその周辺から下面に導出された一対のメタライズ配線導体２４ａ，２４ｂを有する四角平板状のセラミック製の基体２１と、その上面に積層され、中央部に発光素子２３を収容するための貫通孔２２ａを有する四角枠状のセラミック製の枠体２２とから主に構成されている。
【０００３】
そして、基体２１の上面の一方のメタライズ配線導体２４ａが接続された搭載部２１ａ上に発光素子２３を導電性接合材を介して固着するとともに発光素子２３の電極と他方のメタライズ配線導体２４ｂとをボンディングワイヤ２５を介して電気的に接続し、しかる後、枠体２２の貫通孔２２ａ内に透明樹脂（図示せず）を充填して発光素子２３を封止することによって発光装置となる。この発光装置を外部電気回路基板の配線導体に半田を介して接続することによって、発光装置が外部電気回路基板に実装されるとともに搭載する発光装置の電極が外部電気回路に電気的に接続され発光素子２３へ電力が供給されることとなる。
【０００４】
このようなセラミック製のパッケージにおいては、内部に収容する発光素子２３が発する光を枠体２２の貫通孔２２ａの内周面で反射させるが、発光装置の発光効率を良好なものとするために貫通孔２２ａの内周面にニッケル（Ｎｉ）や金（Ａｕ）等の金属から成る金属めっき層２６ｂを表面に有するメタライズ金属層２６ａを被着させている（例えば、下記の特許文献１参照）。
【０００５】
また、近年青色の発光素子の開発が進められ、これに伴って３原色である赤色、緑色、青色をそれぞれ発光する３個の発光素子を１つのパッケージに収納し、フルカラー発光させるようにしたパッケージが用いられるようになってきている。このパッケージは、図８のパッケージの平面図および図９のパッケージの断面図に示すように、基板３１の上面に複数個の発光素子３３を搭載する搭載部３１ａを有するとともに、４隅に平面視で円弧状であって上下面にわたって切り欠かれた切欠き部３４が形成されている。そして、切欠き部３４にそれぞれが電気的に独立した電極が形成されており、搭載部３１ａに搭載される複数個の発光素子３３の電極が４隅の電極の何れかに接続されている。
【０００６】
これにより、例えば搭載部３１ａに３個の発光素子３３を搭載した場合、４つの電極のうち１つを発光素子３３の接地電極と接続される共通電極３４ａ、他の３つを各発光素子３３の駆動用電極と接続される個別電極３４ｂとして３個の発光素子３３が接続可能となる。そして、この３個の発光素子３３をそれぞれ青色、緑色、赤色を発光するものとすれば、フルカラー発光することができる。
【０００７】
また、パッケージの上方へ放射する光の輝度を大きくするために、さらに別個の発光素子３３を搭載している。例えばフルカラー発光させる際に３原色の発光素子３３は色ごとに光の輝度に差があり、特に青色を発光する発光素子３３の輝度が小さいため、すでに搭載されている青色発光用の発光素子３３の他に青色発光用の発光素子３３を１個追加して輝度を大きくしている。そして、追加した発光素子３３は、すでに搭載されている発光素子３３と電気的に同じ接続となるように共通電極３４ａおよび個別電極３４ｂに接続されている（例えば、下記特許文献２参照）。
【０００８】
【特許文献１】
特開平１４−２３２０１７号公報
【０００９】
【特許文献２】
特開平５−１３８１８号公報
【００１０】
【発明が解決しようとする課題】
しかしながら、上記の特許文献１のパッケージによると、基体２１の下面に延出しているメタライズ配線導体２４ａ，２４ｂの面積が小さいため、基体２１となるセラミックグリーンシート（以下、グリーンシートともいう）にメタライズ配線導体２４ａ，２４ｂの形状に金属ペーストを印刷塗布する際、金属ペーストが表面張力により盛り上がりメタライズ配線導体２４ａ，２４ｂを一定の厚みに印刷することができず、メタライズ配線導体２４ａとメタライズ配線導体２４ｂとで高さのバラツキが発生する。すると、メタライズ配線導体２４ａ，２４ｂを外部電気回路基板の配線導体に半田を介して接続した際に、発光装置が外部電気回路基板に対して傾斜した状態で実装される。その結果、発光装置のメタライズ配線導体２４ａ，２４ｂと外部電気回路基板の配線導体との間に位置ずれ等が発生するという問題点があった。
【００１１】
また、上記の特許文献２のパッケージによると、発光素子３３を搭載した発光装置を外部電気回路に接続して発光素子３３に電力を供給する場合に、発光素子３３の接地電極と接続される共通電極３４ａおよび発光素子３３の駆動用電極と接続される個別電極３４ｂの配置をその都度確認して外部電気回路に接続しなければならないため、作業効率が非常に低下するという問題点があった。
【００１２】
また、例えばフルカラー発光させる際に３原色の発光素子３３は色ごとに光の輝度に差があり、特に青色の発光素子３３の輝度が小さいため、すでに搭載されている青色の発光素子３３の他に青色の発光素子３３を１個追加して輝度を大きくしているが、この構成では、輝度を大きくするために搭載された発光素子３３の電気的接続がすでに搭載されている発光素子３３と同じ接続となるように共通電極３４ａ，個別電極３４ｂに接続されている。そのため、すでに搭載されている発光素子３３と追加した発光素子３３の電圧や光波長、輝度などをそれぞれ単独に微調整することができないという問題点があった。
【００１３】
従って、本発明は上記従来の問題点に鑑み完成されたものであり、その目的は、外部電気回路基板の配線導体に位置ずれや傾斜もなく正確に実装できるとともに、接合強度の大きい信頼性の高い実装が可能となり、作業効率が高く、かつ高精度のフルカラー発光ができるように複数個の発光素子を搭載可能なパッケージおよび発光装置を提供することにある。
【００１４】
【課題を解決するための手段】
本発明の発光素子収納用パッケージは、上面に発光素子を搭載するための搭載部が列状に複数形成された帯状の基体の上面に、複数の前記搭載部を取り囲む貫通孔を有する枠体を積層してなる発光素子収納用パッケージであって、前記基体は、４つの角部のそれぞれに前記枠体の下方に位置して上下面にわたって切り欠かれた平面視で円弧状の切欠き部を有し、該切欠き部の内周面に側面導体が形成されており、該側面導体に前記搭載部に搭載される前記発光素子の電極が電気的に接続されることを特徴とする。
【００１５】
本発明の発光素子収納用パッケージは、上面に発光素子を搭載するための搭載部が列状に複数形成された帯状の基体は、４つの角部のそれぞれに枠体の下方に位置して上下面にわたって切り欠かれた平面視で円弧状の切欠き部を有し、切欠き部の内周面に側面導体が形成されていることから、円弧状の切欠き部の内周面に形成された側面導体の表面積は大きなものとなり、基体の下面に形成された電極パッドを外部電気回路基板の配線導体に半田を介して接続する際に、切欠き部の側面導体と外部電気回路基板の配線導体との間に大きな半田のメニスカスが形成されるため、接合強度を大きくすることができる。
【００１６】
また、基体の下面の各電極パッドが外部電気回路基板の配線導体に半田で接合される際に、大きな半田のメニスカスは、各電極パッド間の半田の高さパラツキを吸収するように働き、各電極パッド間の高さバラツキを抑えるとともに接合を強固なものとすることができる。これにより、基体を外部電気回路基板の配線導体に平坦な状態で正確な位置に実装させることができる。
【００１７】
本発明の発光素子収納用パッケージにおいて、好ましくは、前記側面導体は、４つのうち一方の対角位置の２つが前記発光素子の駆動用電極と接続され、他方の対角位置の２つが前記発光素子の接地電極と接続されることを特徴とする。
【００１８】
本発明の発光素子収納用パッケージは、好ましくは側面導体は４つのうち一方の対角位置の２つが発光素子の駆動用電極と接続され、他方の対角位置の２つが発光素子の接地電極と接続されることから、発光素子が搭載された発光装置が外部電気回路基板の配線導体に半田で接合される場合に、発光装置が所定の配置から１８０°回転されて接合されたとしても配置ずれは発生せず、外部の電気回路の配線導体に所定の側面導体が接合されることとなる。その結果、基体の側面導体の配置を接合のたびに確認することも不要となり、作業効率を高くすることができる。
【００１９】
また本発明の発光素子収納用パッケージにおいて、好ましくは、前記複数個の発光素子の少なくとも１個は他の発光素子の輝度調整用であり、輝度調整用の発光素子の電極が電気的に接続される前記側面導体は外部の輝度調整回路に接続されることを特徴とする。
【００２０】
本発明の発光素子収納用パッケージは、好ましくは複数個の発光素子の少なくとも１個は他の発光素子の輝度調整用であり、輝度調整用の発光素子の電極が電気的に接続される側面導体は外部の輝度調整回路に接続されることから、所定の色の発光素子に対して輝度調整用の発光素子を設けた場合、輝度調整用の発光素子の電圧、光波長、輝度などを所定の色の発光素子と別個に調整することができ、所定の色の輝度等を微調整できる。例えばフルカラー発光できるように、青色、緑色、赤色の３個の発光素子を搭載した場合、３個の発光素子にそれぞれ対応して輝度調整用の発光素子を３個搭載し、３原色の発光素子の輝度、色の強さ等をそれぞれ微調整でき、高精彩のフルカラー表示が可能となる。
【００２１】
本発明の発光装置は、上記本発明の発光素子収納用パッケージと、前記複数の搭載部にそれぞれ搭載された発光素子と、該発光素子を覆う透明樹脂とを具備していることを特徴とする。
【００２２】
本発明の発光装置は、上記の構成により、簡略な構成で高い発光効率を有する高性能のものとなるとともに、外部電気回路基板の配線導体に位置ずれや傾斜もなく正確に実装することができるとともに、接合強度の大きい信頼性の高い実装が可能となり、作業効率が高く、かつフルカラー発光できるように複数個の発光素子が搭載可能となる。
【００２３】
【発明の実施の形態】
本発明の発光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、図２はその平面図、図３の（ａ），（ｂ），（ｃ）は図２のパッケージの各絶縁層の平面図である。これらの図において、１は基体、２は枠体、７は切欠き部であり、主としてこれらで本発明のパッケージが構成されている。このパッケージは、例えば青色、緑色、赤色の３原色をそれぞれ発光する発光素子３を設けてフルカラー発光させる発光装置に好適に用いられる。
【００２４】
本発明のパッケージは、上面に発光素子３を搭載するための搭載部１ａが列状に複数形成された帯状の基体１の上面に、複数の搭載部１ａを取り囲む貫通孔を有する枠体２を積層してなるものであって、基体１は、４つの角部のそれぞれに枠体２の下方に位置して上下面にわたって切り欠かれた平面視で円弧状の切欠き部７を有し、切欠き部７の内周面に側面導体７ａ，７ｂが形成されており、側面導体７ａ，７ｂに搭載部１ａに搭載される発光素子３の電極が電気的に接続されるものである。
【００２５】
本発明における基体１は、酸化アルミニウム質焼結体（アルミナセラミックス）、窒化アルミニウム質焼結体等のセラミックスから成る帯状のものであり、複数の発光素子３を支持する支持体であり、その上面に複数の発光素子３を搭載する搭載部１ａを有している。基体１が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グリーンシート（セラミック生シート）を得、しかる後、グリーンシートに適当な打ち抜き加工を施して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。
【００２６】
また、基体１は、その表面および内部を示す図３の（ａ）〜（ｃ）に示すように、表面に搭載部１ａ、メタライズ配線導体４ａ，４ｂが被着形成されている。このメタライズ配線導体４ａ，４ｂは、基体１の４つの角部のそれぞれに上下面にわたって切り欠かれ、平面視で円弧状の切欠き部７の内周面に形成された側面導体７ａ，７ｂおよび基体１内部に被着形成された接続導体９ａ，９ｂを介して、基体１の下面に形成された電極パッド８ａ，８ｂに電気的に接続されている。
【００２７】
本発明において、好ましくは、基体１の２つの長辺側の側面のそれぞれに、上下面にわたって切り欠かれた平面視で円弧状の切欠き部７の内周面に形成された側面導体７ａ，７ｂが形成されていることがよい。この場合、パッケージの基体１を外部電気回路基板の配線導体等に半田で接合する際に、基体１の側面の切欠き部７に形成された側面導体７ａ，７ｂにおいても大きな半田のメニスカスが形成されるため、発光装置がより強固に接合される。また、基体１の側面に側面導体７ａ，７ｂが形成されていることから、その側面導体７ａ，７ｂと発光素子３とを接続するためのメタライズ配線導体４ａ，４ｂが最短のものとなり、短線化される。その結果、メタライズ配線導体４ａ，４ｂの抵抗やインダクタンスが小さくなり、発光素子３を高効率で発光させることが可能となる。
【００２８】
また、メタライズ配線導体４ａ，４ｂ、側面導体７ａ，７ｂ、接続導体９ａ，９ｂおよび電極パッド８ａ，８ｂは、ＷやＭｏ等の金属粉末のメタライズ層から成り、パッケージ内部に収容する３個の発光素子３を外部に電気的に接続するための導電路として機能している。
【００２９】
そして、メタライズ配線導体４ａが接続された搭載部１ａには、発光ダイオード等の発光素子３の接地電極である下面が、金−シリコン合金や銀−エポキシ樹脂等の導電性接合材により固着されている。メタライズ配線導体４ｂの搭載部１ａに隣接するそれぞれの部位には、発光素子３の駆動用電極のそれぞれがボンディングワイヤ５を介して電気的に接続されている。このような発光素子３が３個並ぶようにして搭載される。また、発光素子３は、搭載部１ａおよびメタライズ配線導体４ｂにフリップチップ実装されていてもよい。そして、基体１下面の電極パッド８ａ，８ｂが外部電気回路基板の配線導体に接続されることにより、発光素子３の接地電極および駆動用電極が外部電気回路に電気的に接続され、発光素子３へ電力や駆動信号が供給される。
【００３０】
メタライズ配線導体４ａ，４ｂ、側面導体７ａ，７ｂ、接続導体９ａ，９ｂおよび電極パッド８ａ，８ｂは、例えばＷやＭｏ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、基体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、基体１の所定位置に被着形成される。
【００３１】
なお、メタライズ配線導体４ａ，４ｂ、側面導体７ａ，７ｂおよび電極パッド８ａ，８ｂの露出する表面にＮｉや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、これらの導体が酸化腐蝕するのを有効に防止することができるとともに、メタライズ配線導体４ａと発光素子３、メタライズ配線導体４ｂとボンディングワイヤ５との接合、電極パッド８ａ，８ｂおよび側面導体７ａ，７ｂと外部電気回路基板の配線導体との接合を強固にすることができる。したがって、より好ましくは、メタライズ配線導体４ａ，４ｂ、側面導体７ａ，７ｂおよび電極パッド８ａ，８ｂ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めっき層と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のがよい。
【００３２】
なお、切欠き部７は、基体１用のグリーンシートの４つの角部の部位、さらに、好ましくは２つの長辺の側面の部位に打ち抜き金型で打ち抜いて形成する。このとき、切欠き部７は、枠体２の下方に位置して平面視で枠体２の厚みより小さい曲率半径の円弧状とされてグリーンシートの上下面にわたって切り欠かれるように打ち抜いて形成され、側面導体７ａ，７ｂが切欠き部７の内周面に形成される。
【００３３】
枠体２は、基体１と実質的に同じ組成のセラミックスから成り、基体１の上面に積層されて焼結一体化されて接合されている。枠体２は、グリーンシートに予め、その中央部に発光素子３を収容するための断面形状が四角形状、楕円形状、多角形状等の貫通孔２ａを打ち抜き加工で形成し、これを複数枚積層し、基体１となるグリーンシートの上に積層して焼結一体化して基体１の上面に接合される。
【００３４】
また、枠体２の貫通孔２ａは、枠体２の上面側開口が下面側開口よりも大きく形成されており、貫通孔２ａの内周面は基体１の上面に対する角度θが３５〜７０°であることが好ましい。７０°を超えると、貫通孔２ａ内に収容された発光素子３の光を外部に良好に反射することが困難となる傾向にある。３５°未満では、貫通孔２ａをそのような角度で打ち抜き法で安定的かつ効率良く形成することが困難となるとともに、パッケージが大型化される傾向にある。
【００３５】
また枠体２は、枠体２用のグリーンシートの中央部を打ち抜き金型を用いて打ち抜くことによって形成されるが、このとき、枠体２用のグリーンシートに形成される貫通孔２ａの内周面をグリーンシートの一方の主面から他方の主面に向けて３５〜７０°の角度θで広がるように形成する。このように、貫通孔２ａの内周面がグリーンシートの一方の主面から他方の主面に向けて３５〜７０°の角度θで広がるように形成されることにより、貫通孔２ａの内周面が基体１の上面に対して３５〜７０°の角度θで外側に広がるように形成される。
【００３６】
また、貫通孔２ａの開口の横断面形状は、四角形状、楕円形状、多角形状等の種々の形状でよいが、貫通孔２ａの製作の容易さや形状の安定性等の点から、枠体２の上面側開口と下面側開口が同形状であるのが好ましい。
【００３７】
また、枠体２の貫通孔２ａの内周面の全面には、メタライズ金属層６ａおよび金属めっき層６ｂが形成されているのが好ましく、例えば、ＷやＭｏ等の金属粉末のメタライズ金属層６ａ上にＮｉ，Ａｕ，Ａｇ等の金属めっき層６ｂが被着されている。この金属めっき層６ｂは、発光素子３の光に対する反射率は８０％以上であることが好ましいが、金属めっき層６ｂがＮｉ，Ａｕ，Ａｇ等から成ることによって、発光素子３の光に対する反射率を８０％以上とすることができる。反射率が８０％未満であると、枠体２の貫通孔２ａに収容された発光素子３の光を良好に反射することが困難となる。
【００３８】
また、貫通孔２ａの内周面の全面に形成された金属めっき層６ｂの表面の算術平均粗さＲａは１〜１０μｍが好ましい。１μｍ未満では、貫通孔２ａに収容された発光素子３の光を均一に反射させることができず、反射する光の強さに偏りが発生し易くなる。１０μｍを超えると、貫通孔２ａに収容された発光素子３の光が散乱し、反射光を高い反射率で外部に均一に放射することが困難になる。
【００３９】
このように、本発明のパッケージは、上面に発光素子３を搭載するための搭載部１ａが列状に複数形成された帯状の基体１は、４つの角部のそれぞれに枠体１の下方に位置して上下面にわたって切り欠かれた平面視で円弧状の切欠き部７を有し、切欠き部７の内周面に側面導体７ａ，７ｂが形成されていることから、側面導体７ａ，７ｂの表面積が大きくなる。その結果、基体１の下面に形成された電極パッド８ａ，８ｂを外部電気回路基板の配線導体に半田を介して接続する際に、側面導体７ａ，７ｂと外部電気回路基板の配線導体との間に大きな半田のメニスカスが形成されるため、接合強度を大きくすることができる。
【００４０】
また、基体１の下面の各電極パッド８ａ，８ｂが外部電気回路基板の配線導体に半田で接合される際に、大きな半田のメニスカスは、電極パッド８ａ，８ｂ間の半田の高さパラツキを吸収するように働き、電極パッド８ａ，８ｂ間の高さバラツキを抑え、かつ接合を強固にすることができる。これにより、発光装置を外部電気回路基板の配線導体に平坦な状態で正確な位置に実装できる。
【００４１】
また、好ましくは基体１の２つの長辺の側面にも側面導体７ａ，７ｂが形成されることから、その側面導体７ａ，７ｂと発光素子３とを接続するためのメタライズ配線導体４ａ，４ｂとが短線化される。また、搭載部１ａに搭載される複数の発光素子３の電極が、側面導体７ａ，７ｂを介して、基体１内部に形成された共通の接続導体で９ａ，９ｂに電気的に接続されることから、発光素子３への駆動信号、接地電位の導電路がさらに短線化される。これにより、メタライズ配線導体４ａ，４ｂの抵抗やインダクタンスが小さくなり、発光素子３を高効率で発光させることが可能となる。
【００４２】
なお、電極パッド８ａ，８ｂは、表面の平坦度が２０μｍ／１０ｍｍ以下であることが好ましい。２０μｍ／１０ｍｍを超えると、電極パッド８ａ，８ｂを外部電子回路基板の配線導体に半田を介して接続する際に、電極パッド８ａ，８ｂ間に高さのバラツキが発生し、電極パッド８ａ，８ｂを上記配線導体の正確な位置に実装するのが困難となる。
【００４３】
また、電極パッド８ａ，８ｂは、略均等に同じ面積で配置され、それらの合計の面積が基体１下面の面積の１５〜４０％であることが好ましい。１５％未満では、電極パッド８ａ，８ｂの平坦性が劣化し易くなり、４０％を超えると、電極パッド８ａ，８ｂを接合するための半田の量が多くなり半田の表面張力による高さパラツキが大きくなる。
【００４４】
なお、基体１の４つの角部に形成された側面導体７ａ，７ｂに接続された電極パッド８ａ，８ｂ以外に、基体１の２つの長辺の側面の側面導体７ａ，７ｂに接続された電極パッド８ａ，８ｂを基体１下面に形成することができる。この場合、基体１の２つの長辺の側面の側面導体７ａ，７ｂに接続された電極パッド８ａ，８ｂは、外部電気回路基板の配線導体との電気的接続は不要であり、接続強度を大きくするために形成される。
【００４５】
また、切欠き部７は枠体２の下方に位置していることから、枠体２の貫通孔２ａ内に充填される透明樹脂が切欠き部７へ流れ出すのを有効に防止して封止が良好なものとなる。
【００４６】
本発明のパッケージは、好ましくは、側面導体７ａ，７ｂは、４つの角部のうち一方の対角位置の２つの側面導体７ｂが発光素子３の駆動用電極と接続され、他方の対角位置の２つの側面導体７ａが発光素子３の接地電極と接続されることから、発光素子３が搭載される発光装置が外部電気回路基板の配線導体に半田で接合される際に、発光装置が水平に１８０°回転して接合されたとしても外部電気回路基板の配線導体には同じ側面導体７ａ，７ｂが接合されることとなる。そのため、基体１の側面導体７ａ，７ｂの配置を接合のたびに確認する必要はなく、作業効率を高くすることが可能となる。
【００４７】
また、本発明のパッケージは、図４のパッケージの断面図、図５の平面図および図６（ａ）〜（ｃ）の平面図に示すように、３個の発光素子１３ｄ，１３ｅ，１３ｆから成る１組が、他の３個の発光素子１３ａ，１３ｂ，１３ｃから成る１組の輝度調整用であることがよい。輝度調整用の発光素子１３ｄ〜１３ｆの電極がメタライズ配線導体１４ｃ，１４ｄ、接続導体１９ｃ，１９ｄおよび側面導体１７ｃ，１７ｄを介して基体１１の下面に形成された電極パッド１８ｃ，１８ｄに電気的に接続され、電極パッド１８ｃ，１８ｄが外部の輝度調整回路に電気的に独立して接続されている。これにより、発光素子の駆動電圧、光波長、輝度などの調整を高精度に行なうことができる。
【００４８】
例えばフルカラー発光できるように、青色、緑色、赤色の３原色をそれぞれ発光する発光素子１３ａ〜１３ｃを搭載した場合、発光素子１３ａ〜１３ｃにそれぞれ対応して輝度調整用の発光素子１３ｄ〜１３ｆを搭載し、発光素子１３ａ〜１３ｃのそれぞれの輝度等の微調整を行なうことができる。その結果、３個１組の発光素子１３ａ〜１３ｃの色の強さ、輝度、色合を精度よく調整できる。
【００４９】
また、図５に示すように、基体１１に搭載される発光素子１３ａ〜１３ｃの１組と発光素子１３ｄ〜１３ｆの１組とは、その並びが基体１１の上面の中心に関して対称に配置され搭載されていることがよい。これにより、発光装置が水平に１８０°回転されて接合されたとしても、外部の電気回路基板の配線導体に同じ側面導体１７ａ〜１７ｄが接合されるため、発光装置の電気的接続は正常に保持される。その結果、基体１１の側面導体１７ａ〜１７ｄの配置を接合のたびに確認する必要はなく、接合の作業効率を高くすることができる。
【００５０】
なお、図４〜図６において、１４ａ，１４ｂ，１４ｃ，１４ｄはメタライズ配線層、１５はボンディングワイヤ、１９ａ，１９ｂ，１９ｃ，１９ｄは接続導体である。
【００５１】
かくして、本発明のパッケージは、基体１の搭載部１ａに複数の発光素子３を搭載するとともに発光素子３の電極をメタライズ配線導体４ｂにボンディングワイヤ５を介して電気的に接続し、しかる後、発光素子３を覆うようにシリコーン樹脂やエポキシ樹脂等の透明樹脂を設けて発光素子３を封止することによって発光装置となる。発光素子３を覆う透明樹脂は、枠体２の内側に充填されていてもよいし、発光素子３およびその周囲のみを覆うように設けられていてもよい。
【００５２】
また、枠体２の上面にガラス，石英，サファイア，透光性樹脂等からなる透光性蓋体を接合してもよい。また、本発明の発光装置は、発光ダイオード等の発光素子３を複数個収納した小型のものであることから、個々に蓋をするよりも透明樹脂で発光素子３のすべてを覆った方が封止の作業性が良く、また内部のボンディングワイヤ５等の位置固定や各導体層の腐蝕防止等の点で有利なものである。
【００５３】
なお、本発明は上述の実施の形態に限定されず、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。
【００５４】
【発明の効果】
本発明の発光素子収納用パッケージは、上面に発光素子を搭載するための搭載部が列状に複数形成された帯状の基体は、４つの角部のそれぞれに枠体の下方に位置して上下面にわたって切り欠かれた平面視で円弧状の切欠き部を有し、切欠き部の内周面に側面導体が形成されていることから、円弧状の切欠き部の内周面に形成された側面導体の表面積は大きなものとなり、基体の下面に形成された電極パッドを外部電気回路基板の配線導体に半田を介して接続する際に、切欠き部の側面導体と外部電気回路基板の配線導体との間に大きな半田のメニスカスが形成されるため、接合強度を大きくすることができる。
【００５５】
また、基体の下面の各電極パッドが外部電気回路基板の配線導体に半田で接合される際に、大きな半田のメニスカスは、各電極パッド間の半田の高さパラツキを吸収するように働き、各電極パッド間の高さバラツキを抑えるとともに接合を強固なものとすることができる。これにより、基体を外部電気回路基板の配線導体に平坦な状態で正確な位置に実装させることができる。
【００５６】
本発明の発光素子収納用パッケージは、好ましくは側面導体は４つのうち一方の対角位置の２つが発光素子の駆動用電極と接続され、他方の対角位置の２つが発光素子の接地電極と接続されることから、発光素子が搭載された発光装置が外部電気回路基板の配線導体に半田で接合される場合に、発光装置が所定の配置から水平に１８０°回転されて接合されたとしても配置ずれは発生せず、外部の電気回路の配線導体に所定の側面導体が接合されることとなる。その結果、基体の側面導体の配置を接合のたびに確認することも不要となり、作業効率を高くすることができる。
【００５７】
また本発明の発光素子収納用パッケージは、好ましくは複数個の発光素子の少なくとも１個は他の発光素子の輝度調整用であり、輝度調整用の発光素子の電極が電気的に接続される側面導体は外部の輝度調整回路に接続されることから、所定の色の発光素子に対して輝度調整用の発光素子を設けた場合、輝度調整用の発光素子の駆動電圧、光波長、輝度などを所定の色の発光素子と別個に調整することができ、所定の色の輝度等を微調整できる。例えばフルカラー発光できるように、青色、緑色、赤色の３個の発光素子を搭載した場合、３個の発光素子にそれぞれ対応して輝度調整用の発光素子を３個搭載し、３原色の発光素子の輝度、色の強さ等をそれぞれ微調整でき、高精彩のフルカラー表示が可能となる。
【００５８】
本発明の発光装置は、上記本発明の発光素子収納用パッケージと、複数の搭載部にそれぞれ搭載された発光素子と、発光素子を覆う透明樹脂とを具備していることにより、簡略な構成で高い発光効率を有する高性能のものとなるとともに、外部電気回路基板の配線導体に位置ずれや傾斜もなく正確に実装することができるとともに、接合強度の大きい信頼性の高い実装が可能となり、作業効率が高く、かつフルカラー発光できるように複数個の発光素子が搭載可能となる。
【図面の簡単な説明】
【図１】本発明の発光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】図１の発光素子収納用パッケージの平面図である。
【図３】（ａ）〜（ｃ）は図１の発光素子収納用パッケージにおける基体の各絶縁層の平面図である。
【図４】本発明の発光素子収納用パッケージの実施の形態の他の例を示す断面図である。
【図５】図４の発光素子収納用パッケージの平面図である。
【図６】（ａ）〜（ｃ）は図４の発光素子収納用パッケージにおける基体の各絶縁層の平面図である。
【図７】従来の発光素子収納用パッケージの断面図である。
【図８】従来の発光素子収納用パッケージの他の例の平面図である。
【図９】図８の発光素子収納用パッケージのＡ−Ａ線における断面図である。
【符号の説明】
１：基体
１ａ：搭載部
２：枠体
３：発光素子
７：切欠き部
７ａ，７ｂ：側面導体
８ａ，８ｂ：電極パッド[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light emitting element housing package for housing a light emitting element and a light emitting device used for a display device or the like using a light emitting element such as a light emitting diode.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a ceramic package has been used as a light emitting element housing package (hereinafter, simply referred to as a package) for housing a light emitting element such as a light emitting diode. As shown in the cross-sectional view of the package of FIG. 7, the conventional ceramic package has a mounting portion 21a formed of a conductor layer for mounting the light emitting element 23 at the center of the upper surface, and the mounting portion 21a and its periphery. And a square plate-like ceramic base 21 having a pair of metallized wiring conductors 24a and 24b led out to the lower surface, and a through hole 22a for accommodating the light emitting element 23 in the center portion, laminated on the upper surface thereof. It is mainly composed of a frame-shaped ceramic frame 22.
[0003]
Then, the light emitting element 23 is fixed via a conductive bonding material on the mounting portion 21a to which the one metallized wiring conductor 24a on the upper surface of the base 21 is connected, and the electrode of the light emitting element 23 and the other metallized wiring conductor 24b are connected. A light emitting device is obtained by electrically connecting via the bonding wire 25 and then filling the through hole 22a of the frame 22 with a transparent resin (not shown) and sealing the light emitting element 23. By connecting the light emitting device to the wiring conductor of the external electric circuit board via solder, the light emitting device is mounted on the external electric circuit board and the electrodes of the mounted light emitting device are electrically connected to the external electric circuit to emit light. Power is supplied to the element 23.
[0004]
In such a ceramic package, the light emitted from the light emitting element 23 housed inside is reflected by the inner peripheral surface of the through hole 22a of the frame 22, but in order to improve the luminous efficiency of the light emitting device. A metallized metal layer 26a having a metal plating layer 26b made of a metal such as nickel (Ni) or gold (Au) on the inner peripheral surface of the through hole 22a is adhered (for example, see Patent Document 1 below). .
[0005]
In recent years, blue light-emitting elements have been developed, and accordingly, three light-emitting elements that emit red, green, and blue light, which are the three primary colors, are housed in a single package to emit full-color light. Is being used. As shown in the plan view of the package of FIG. 8 and the cross-sectional view of the package of FIG. 9, this package has a mounting portion 31a for mounting a plurality of light emitting elements 33 on the upper surface of a substrate 31, and has four corners in plan view. A notch 34 is formed in the shape of an arc and cut out over the upper and lower surfaces. Electrodes that are electrically independent of each other are formed in the cutout portions 34, and the electrodes of the plurality of light emitting elements 33 mounted on the mounting portion 31a are connected to any of the four corner electrodes.
[0006]
Thus, for example, when three light emitting elements 33 are mounted on the mounting portion 31a, one of the four electrodes is a common electrode 34a connected to the ground electrode of the light emitting element 33, and the other three electrodes are each a light emitting element 33. The three light emitting elements 33 can be connected as the individual electrodes 34b connected to the driving electrodes. If the three light emitting elements 33 emit blue, green, and red light, respectively, full-color light emission can be performed.
[0007]
Further, in order to increase the luminance of light emitted above the package, a separate light emitting element 33 is mounted. For example, when emitting full color light, the light emitting elements 33 of the three primary colors have a difference in light luminance for each color. In particular, since the luminance of the light emitting element 33 that emits blue light is small, the light emitting element 33 for blue light emission already mounted is used. In addition, one blue light emitting element 33 is added to increase the luminance. Further, the added light emitting element 33 is connected to the common electrode 34a and the individual electrode 34b so as to be electrically connected to the already mounted light emitting element 33 (for example, see Patent Document 2 below).
[0008]
[Patent Document 1]
JP-A-14-232017
[0009]
[Patent Document 2]
JP-A-5-13818
[0010]
[Problems to be solved by the invention]
However, according to the package of Patent Document 1, since the area of the metallized wiring conductors 24a and 24b extending on the lower surface of the base 21 is small, the metallized ceramic green sheet (hereinafter, also referred to as a green sheet) serving as the base 21 is formed. When printing and applying a metal paste to the shapes of the wiring conductors 24a and 24b, the metal paste swells due to surface tension and the metallized wiring conductors 24a and 24b cannot be printed to a certain thickness, and the metallized wiring conductors 24a and 24b are not printed. And a variation in height occurs. Then, when the metallized wiring conductors 24a and 24b are connected to the wiring conductors of the external electric circuit board via solder, the light emitting device is mounted in a state inclined with respect to the external electric circuit board. As a result, there is a problem that a displacement or the like occurs between the metallized wiring conductors 24a and 24b of the light emitting device and the wiring conductor of the external electric circuit board.
[0011]
Further, according to the package of Patent Document 2, when a light emitting device equipped with the light emitting element 33 is connected to an external electric circuit to supply power to the light emitting element 33, a common electrode connected to the ground electrode of the light emitting element 33 is provided. Since the arrangement of the electrode 34a and the individual electrode 34b connected to the driving electrode of the light emitting element 33 must be checked each time and connected to an external electric circuit, there is a problem that the working efficiency is greatly reduced.
[0012]
In addition, for example, when full-color light emission is performed, the light emitting elements 33 of the three primary colors have differences in light luminance for each color. In particular, since the luminance of the blue light emitting element 33 is low, the light emitting element Although the luminance is increased by adding one blue light emitting element 33 to the light emitting element 33, in this configuration, the electric connection of the light emitting element 33 mounted to increase the luminance is compared with the light emitting element 33 already mounted. They are connected to the common electrode 34a and the individual electrodes 34b so as to have the same connection. Therefore, there is a problem that the voltage, light wavelength, luminance, and the like of the light emitting element 33 already mounted and the light emitting element 33 added cannot be finely adjusted independently.
[0013]
Therefore, the present invention has been completed in view of the above-mentioned conventional problems, and an object of the present invention is to provide a wiring conductor of an external electric circuit board that can be accurately mounted without displacement or inclination, and that has a high bonding strength and reliability. An object of the present invention is to provide a package and a light-emitting device which can be mounted at a high level, have a high work efficiency, and can mount a plurality of light-emitting elements so as to perform full-color light emission with high accuracy.
[0014]
[Means for Solving the Problems]
The light-emitting element housing package of the present invention includes a frame body having a through-hole surrounding a plurality of the mounting portions on an upper surface of a band-shaped base in which a plurality of mounting portions for mounting the light-emitting elements on the upper surface are formed in a row. A light-emitting element housing package formed by stacking, wherein the base is provided with an arc-shaped notch in a plan view, which is cut out over the upper and lower surfaces and located below the frame at each of four corners. A side conductor is formed on an inner peripheral surface of the notch, and an electrode of the light emitting element mounted on the mounting portion is electrically connected to the side conductor.
[0015]
In the light-emitting element housing package according to the present invention, a strip-shaped substrate having a plurality of mounting portions for mounting the light-emitting element on the upper surface is positioned below the frame at each of the four corners. It has an arc-shaped notch in plan view cut out over the lower surface, and the side conductor is formed on the inner peripheral surface of the notch, so it is formed on the inner peripheral surface of the arc-shaped notch. When the electrode pad formed on the lower surface of the base is connected to the wiring conductor of the external electric circuit board via solder, the side conductor of the notch and the wiring of the external electric circuit board become large. Since a large solder meniscus is formed between the conductor and the conductor, the bonding strength can be increased.
[0016]
In addition, when each electrode pad on the lower surface of the base is joined to the wiring conductor of the external electric circuit board by solder, a large meniscus of the solder acts to absorb the height variation of the solder between the electrode pads, and The height variation between the electrode pads can be suppressed, and the bonding can be strengthened. Thus, the base can be mounted on the wiring conductor of the external electric circuit board at a precise position in a flat state.
[0017]
In the light-emitting element housing package according to the present invention, preferably, two of the four side conductors at one diagonal position of the four side conductors are connected to the driving electrode of the light-emitting element, and two at the other diagonal position are the light-emitting elements. It is characterized by being connected to a ground electrode of the element.
[0018]
In the light-emitting element housing package of the present invention, preferably, two of the four side conductors at one diagonal position of the four side conductors are connected to the driving electrode of the light-emitting element, and two at the other diagonal position are connected to the ground electrode of the light-emitting element. Due to the connection, when the light emitting device on which the light emitting element is mounted is joined to the wiring conductor of the external electric circuit board by soldering, even if the light emitting device is rotated by 180 ° from the predetermined arrangement, the misalignment occurs. Does not occur, and the predetermined side conductor is joined to the wiring conductor of the external electric circuit. As a result, it is not necessary to check the arrangement of the side conductors of the base every time joining is performed, and the working efficiency can be increased.
[0019]
In the light-emitting element housing package of the present invention, preferably, at least one of the plurality of light-emitting elements is for adjusting the luminance of another light-emitting element, and the electrodes of the light-emitting element for luminance adjustment are electrically connected. The side conductor is connected to an external brightness adjustment circuit.
[0020]
In the light-emitting element housing package of the present invention, preferably, at least one of the plurality of light-emitting elements is for adjusting luminance of another light-emitting element, and a side conductor to which electrodes of the light-emitting element for luminance adjustment are electrically connected. Is connected to an external brightness adjustment circuit, so when a light emission element for brightness adjustment is provided for a light emission element of a predetermined color, the voltage, light wavelength, brightness, etc. of the light emission element for brightness adjustment are set to a predetermined value. It can be adjusted separately from the light emitting element of the color, and the brightness of the predetermined color can be finely adjusted. For example, when three light-emitting elements of blue, green, and red are mounted so that full-color light emission can be performed, three light-emitting elements for adjusting brightness are mounted corresponding to the three light-emitting elements, respectively, and light-emitting elements of three primary colors are provided. Brightness, color intensity, etc., can be finely adjusted, and high-definition full-color display becomes possible.
[0021]
A light-emitting device of the present invention includes the light-emitting element housing package of the present invention, a light-emitting element mounted on each of the plurality of mounting portions, and a transparent resin covering the light-emitting element. .
[0022]
The light emitting device of the present invention has a simple structure and high performance with high luminous efficiency, and can be accurately mounted on a wiring conductor of an external electric circuit board without displacement or inclination. At the same time, mounting with high bonding strength and high reliability is possible, and a plurality of light emitting elements can be mounted so as to achieve high working efficiency and full color light emission.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
The light emitting element housing package of the present invention will be described in detail below. FIG. 1 is a sectional view showing an example of an embodiment of the package of the present invention, FIG. 2 is a plan view thereof, and FIGS. 3 (a), (b) and (c) show the respective insulating layers of the package of FIG. It is a top view. In these figures, 1 is a base, 2 is a frame, and 7 is a notch, and these mainly constitute the package of the present invention. This package is suitably used for a light-emitting device that emits full-color light by providing, for example, light-emitting elements 3 that emit light of three primary colors of blue, green, and red, respectively.
[0024]
In the package of the present invention, a frame 2 having a through hole surrounding a plurality of mounting portions 1a is formed on an upper surface of a band-shaped base body 1 on which a plurality of mounting portions 1a for mounting the light emitting elements 3 are formed in a row. The base body 1 has an arc-shaped notch 7 in a plan view, which is located below the frame 2 and is notched over the upper and lower surfaces at each of the four corners, Side conductors 7a and 7b are formed on the inner peripheral surface of the notch 7, and the electrodes of the light emitting element 3 mounted on the mounting portion 1a are electrically connected to the side conductors 7a and 7b.
[0025]
The base 1 according to the present invention is a belt-shaped member made of ceramics such as an aluminum oxide sintered body (alumina ceramics) and an aluminum nitride sintered body, and is a support for supporting the plurality of light emitting elements 3, and has an upper surface thereof. And a mounting section 1a for mounting a plurality of light emitting elements 3. When the substrate 1 is made of, for example, an aluminum oxide-based sintered body, a raw material powder such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide is mixed with a suitable organic binder, a solvent, and the like to form a slurry. A green sheet (green ceramic sheet) is obtained by forming the sheet into a sheet by a well-known doctor blade method, a calendar roll method, or the like. Thereafter, a plurality of green sheets are subjected to appropriate punching and laminated at a high temperature (about (1600 ° C.).
[0026]
Further, as shown in FIGS. 3A to 3C showing the surface and the inside of the base 1, the mounting portion 1a and the metallized wiring conductors 4a and 4b are formed on the surface. The metallized wiring conductors 4a and 4b are cut out at the four corners of the base 1 over the upper and lower surfaces, and the side conductors 7a and 7b formed on the inner peripheral surface of the notch 7 having an arc shape in plan view. It is electrically connected to electrode pads 8a, 8b formed on the lower surface of the base 1 through connection conductors 9a, 9b adhered and formed inside the base 1.
[0027]
In the present invention, preferably, the side conductors 7a, 7a, which are formed on the inner peripheral surface of the arc-shaped notch 7 in plan view, which is cut out over the upper and lower surfaces, on each of the two long side surfaces of the base 1. 7b is preferably formed. In this case, when the package base 1 is joined to a wiring conductor or the like of the external electric circuit board by soldering, a large solder meniscus is formed also in the side conductors 7a and 7b formed in the cutouts 7 on the side surfaces of the base 1. Therefore, the light emitting device is more firmly joined. Further, since the side conductors 7a and 7b are formed on the side surfaces of the base 1, the metallized wiring conductors 4a and 4b for connecting the side conductors 7a and 7b and the light emitting element 3 are shortest, and the length is reduced. Is done. As a result, the resistance and inductance of the metallized wiring conductors 4a and 4b are reduced, and the light emitting element 3 can emit light with high efficiency.
[0028]
The metallized wiring conductors 4a and 4b, the side conductors 7a and 7b, the connection conductors 9a and 9b, and the electrode pads 8a and 8b are formed of a metallized layer of a metal powder such as W or Mo, and the three light emitting elements housed inside the package are provided. It functions as a conductive path for electrically connecting the element 3 to the outside.
[0029]
The lower surface, which is the ground electrode of the light emitting element 3 such as a light emitting diode, is fixed to the mounting portion 1a to which the metallized wiring conductor 4a is connected by a conductive bonding material such as a gold-silicon alloy or a silver-epoxy resin. I have. Driving electrodes of the light emitting element 3 are electrically connected via bonding wires 5 to respective portions of the metallized wiring conductor 4b adjacent to the mounting portion 1a. The three light emitting elements 3 are mounted so as to be arranged side by side. Further, the light emitting element 3 may be flip-chip mounted on the mounting portion 1a and the metallized wiring conductor 4b. Then, by connecting the electrode pads 8a and 8b on the lower surface of the base 1 to the wiring conductors of the external electric circuit board, the ground electrode and the driving electrode of the light emitting element 3 are electrically connected to the external electric circuit. Power and drive signals are supplied to the
[0030]
The metallized wiring conductors 4a and 4b, side conductors 7a and 7b, connection conductors 9a and 9b, and electrode pads 8a and 8b were obtained by adding a suitable organic solvent and a solvent to a high melting point metal powder such as W or Mo. The green paste serving as the base 1 is preliminarily printed and applied in a predetermined pattern by a screen printing method, whereby the metal paste is adhered and formed at a predetermined position on the base 1.
[0031]
It is preferable that a metal having excellent corrosion resistance such as Ni or Au is applied to the exposed surfaces of the metallized wiring conductors 4a and 4b, the side conductors 7a and 7b, and the electrode pads 8a and 8b in a thickness of about 1 to 20 μm. Often, these conductors can be effectively prevented from being oxidized and corroded, and the metallized wiring conductor 4a and the light emitting element 3, the metallized wiring conductor 4b and the bonding wire 5, the connection between the electrode pads 8a and 8b, and the side conductor 7a. , 7b and the wiring conductor of the external electric circuit board can be strengthened. Therefore, more preferably, a Ni plating layer having a thickness of about 1 to 10 μm and a Ni plating layer having a thickness of about 0.1 to 3 μm are formed on the exposed surfaces of the metallized wiring conductors 4 a and 4 b, the side conductors 7 a and 7 b, and the electrode pads 8 a and 8 b. It is preferable that the Au plating layer is sequentially applied by an electrolytic plating method or an electroless plating method.
[0032]
The notch 7 is formed by punching out the four corners of the green sheet for the base 1, and more preferably, the two long side surfaces using a punching die. At this time, the cutout portion 7 is formed by punching out so as to be located below the frame body 2, formed in an arc shape having a radius of curvature smaller than the thickness of the frame body 2 in plan view, and cut out over the upper and lower surfaces of the green sheet. Then, the side conductors 7 a and 7 b are formed on the inner peripheral surface of the notch 7.
[0033]
The frame 2 is made of ceramics having substantially the same composition as the base 1, and is laminated on the upper surface of the base 1, sintered and integrated, and joined. The frame 2 is formed by punching through holes 2a in the center of a green sheet in advance, the center of which has a square, elliptical, or polygonal cross section for accommodating the light emitting element 3, and laminating a plurality of the through holes. Then, it is laminated on a green sheet serving as the base 1, sintered and integrated, and joined to the upper surface of the base 1.
[0034]
The through hole 2a of the frame 2 is formed such that the opening on the upper surface of the frame 2 is larger than the opening on the lower surface, and the inner peripheral surface of the through hole 2a has an angle θ of 35 to 70 ° with respect to the upper surface of the base 1. It is preferable that If it exceeds 70 °, it tends to be difficult to favorably reflect light of the light emitting element 3 housed in the through hole 2a to the outside. If the angle is less than 35 °, it is difficult to form the through-hole 2a stably and efficiently by the punching method at such an angle, and the package tends to be large.
[0035]
The frame 2 is formed by punching out the center of the green sheet for the frame 2 using a punching die. At this time, the inside of the through hole 2a formed in the green sheet for the frame 2 is formed. The peripheral surface is formed so as to extend from one main surface of the green sheet toward the other main surface at an angle θ of 35 to 70 °. As described above, the inner peripheral surface of the through hole 2a is formed so as to spread at an angle θ of 35 to 70 ° from one main surface to the other main surface of the green sheet, so that the inner peripheral surface of the through hole 2a is formed. The surface is formed so as to spread outward at an angle θ of 35 to 70 ° with respect to the upper surface of the base 1.
[0036]
The cross-sectional shape of the opening of the through hole 2a may be various shapes such as a square shape, an elliptical shape, and a polygonal shape. However, from the viewpoint of the ease of manufacturing the through hole 2a and the stability of the shape, the frame 2 It is preferable that the upper surface side opening and the lower surface side opening have the same shape.
[0037]
It is preferable that a metallized metal layer 6a and a metal plating layer 6b are formed on the entire inner peripheral surface of the through hole 2a of the frame body 2. For example, the metallized metal layer 6a of a metal powder such as W or Mo is preferably used. A metal plating layer 6b of Ni, Au, Ag or the like is adhered thereon. The metal plating layer 6b preferably has a reflectance of 80% or more for light of the light emitting element 3. However, since the metal plating layer 6b is made of Ni, Au, Ag, or the like, the reflectance of the light emitting element 3 for light is high. Can be 80% or more. If the reflectance is less than 80%, it becomes difficult to satisfactorily reflect the light of the light emitting element 3 accommodated in the through hole 2a of the frame 2.
[0038]
The arithmetic average roughness Ra of the surface of the metal plating layer 6b formed on the entire inner peripheral surface of the through hole 2a is preferably 1 to 10 μm. If it is less than 1 μm, the light of the light emitting element 3 accommodated in the through hole 2a cannot be reflected uniformly, and the intensity of the reflected light tends to be uneven. If it exceeds 10 μm, the light of the light emitting element 3 housed in the through hole 2a is scattered, and it becomes difficult to uniformly radiate the reflected light to the outside with a high reflectance.
[0039]
As described above, in the package of the present invention, the strip-shaped base 1 in which the mounting portions 1a for mounting the light emitting elements 3 on the upper surface are formed in a row is provided below the frame 1 at each of the four corners. It has an arc-shaped notch 7 in a plan view, which is cut out over the upper and lower surfaces, and the side conductors 7a, 7b are formed on the inner peripheral surface of the notch 7, so that the side conductors 7a, 7b are formed. 7b has a large surface area. As a result, when the electrode pads 8a, 8b formed on the lower surface of the base 1 are connected to the wiring conductors of the external electric circuit board via solder, the connection between the side conductors 7a, 7b and the wiring conductors of the external electric circuit board is made. Since a large solder meniscus is formed, the bonding strength can be increased.
[0040]
When each of the electrode pads 8a and 8b on the lower surface of the base 1 is soldered to the wiring conductor of the external electric circuit board, the large meniscus of the solder absorbs the variation in the height of the solder between the electrode pads 8a and 8b. And the height variation between the electrode pads 8a and 8b can be suppressed and the bonding can be strengthened. Thereby, the light emitting device can be mounted on the wiring conductor of the external electric circuit board in a flat and accurate position.
[0041]
Also, since side conductors 7a and 7b are preferably formed on the two long side surfaces of base 1, metallized wiring conductors 4a and 4b for connecting side conductors 7a and 7b and light emitting element 3 are formed. Is shortened. Further, the electrodes of the plurality of light emitting elements 3 mounted on the mounting portion 1a are electrically connected to 9a, 9b via side conductors 7a, 7b by a common connection conductor formed inside the base 1. Therefore, the drive signal to the light emitting element 3 and the conductive path of the ground potential are further shortened. Accordingly, the resistance and inductance of the metallized wiring conductors 4a and 4b are reduced, and the light emitting element 3 can emit light with high efficiency.
[0042]
The electrode pads 8a and 8b preferably have a surface flatness of 20 μm / 10 mm or less. If it exceeds 20 μm / 10 mm, when connecting the electrode pads 8a, 8b to the wiring conductors of the external electronic circuit board via solder, a variation in height occurs between the electrode pads 8a, 8b, and the electrode pads 8a, 8b At the correct position of the wiring conductor.
[0043]
Further, the electrode pads 8a and 8b are arranged almost equally in the same area, and the total area thereof is preferably 15 to 40% of the area of the lower surface of the base 1. If it is less than 15%, the flatness of the electrode pads 8a and 8b tends to deteriorate, and if it exceeds 40%, the amount of solder for joining the electrode pads 8a and 8b increases and the height variation due to the surface tension of the solder is reduced. growing.
[0044]
In addition to the electrode pads 8a and 8b connected to the side conductors 7a and 7b formed at the four corners of the base 1, the electrodes connected to the side conductors 7a and 7b on the two long side surfaces of the base 1 The pads 8a and 8b can be formed on the lower surface of the base 1. In this case, the electrode pads 8a and 8b connected to the side conductors 7a and 7b on the two long sides of the base 1 do not need to be electrically connected to the wiring conductor of the external electric circuit board, and the connection strength is large. Formed to
[0045]
In addition, since the notch 7 is located below the frame 2, the transparent resin filled in the through-hole 2 a of the frame 2 is effectively prevented from flowing out to the notch 7 and sealed. Is good.
[0046]
In the package of the present invention, preferably, the side conductors 7a and 7b are connected to the driving electrode of the light emitting element 3 at the two diagonal positions of one of the four corners and at the other diagonal position. Since the two side conductors 7a are connected to the ground electrode of the light emitting element 3, when the light emitting apparatus on which the light emitting element 3 is mounted is joined to the wiring conductor of the external electric circuit board by soldering, the light emitting apparatus is horizontal. The same side conductors 7a and 7b are joined to the wiring conductors of the external electric circuit board even if they are joined by being rotated by 180 °. Therefore, it is not necessary to check the arrangement of the side conductors 7a and 7b of the base 1 every time joining is performed, and the working efficiency can be increased.
[0047]
Further, the package of the present invention includes three light emitting elements 13d, 13e, and 13f as shown in the cross-sectional view of the package of FIG. 4, the plan view of FIG. 5, and the plan views of FIGS. It is preferable that the one set is used for one set of brightness adjustment composed of the other three light emitting elements 13a, 13b, and 13c. The electrodes of the light emitting elements 13d to 13f for adjusting the brightness are electrically connected to the electrode pads 18c and 18d formed on the lower surface of the base 11 via the metallized wiring conductors 14c and 14d, the connection conductors 19c and 19d, and the side conductors 17c and 17d. The electrode pads 18c and 18d are electrically connected independently to an external brightness adjustment circuit. This makes it possible to adjust the drive voltage, light wavelength, luminance, and the like of the light emitting element with high accuracy.
[0048]
For example, when the light-emitting elements 13a to 13c that emit the three primary colors of blue, green, and red respectively are mounted so that full-color light emission can be performed, the light-emitting elements 13d to 13f for adjusting the brightness are mounted corresponding to the light-emitting elements 13a to 13c, respectively. Then, fine adjustment of the luminance and the like of each of the light emitting elements 13a to 13c can be performed. As a result, it is possible to accurately adjust the color intensity, luminance, and hue of the set of three light emitting elements 13a to 13c.
[0049]
As shown in FIG. 5, one set of the light emitting elements 13a to 13c and one set of the light emitting elements 13d to 13f mounted on the base 11 are arranged such that their arrangement is symmetric with respect to the center of the upper surface of the base 11, and It is good that it is. Accordingly, even if the light emitting device is rotated by 180 ° horizontally and joined, the same side conductors 17a to 17d are joined to the wiring conductors of the external electric circuit board, so that the electrical connection of the light emitting device is normally maintained. Is done. As a result, it is not necessary to check the arrangement of the side conductors 17a to 17d of the base 11 every time the joining is performed, and the joining work efficiency can be increased.
[0050]
4 to 6, 14a, 14b, 14c and 14d are metallized wiring layers, 15 is a bonding wire, and 19a, 19b, 19c and 19d are connection conductors.
[0051]
Thus, in the package of the present invention, the plurality of light emitting elements 3 are mounted on the mounting portion 1a of the base 1, and the electrodes of the light emitting elements 3 are electrically connected to the metallized wiring conductors 4b via the bonding wires 5, and thereafter, A light emitting device is obtained by providing a transparent resin such as a silicone resin or an epoxy resin so as to cover the light emitting element 3 and sealing the light emitting element 3. The transparent resin that covers the light emitting element 3 may be filled inside the frame 2 or may be provided so as to cover only the light emitting element 3 and its surroundings.
[0052]
Further, a light-transmitting lid made of glass, quartz, sapphire, light-transmitting resin, or the like may be joined to the upper surface of the frame 2. In addition, since the light emitting device of the present invention is a small one in which a plurality of light emitting elements 3 such as light emitting diodes are housed, it is better to cover all the light emitting elements 3 with a transparent resin than to individually cover them. This is advantageous in terms of workability of stopping, good fixation of the position of the internal bonding wires 5 and the like, prevention of corrosion of each conductor layer, and the like.
[0053]
Note that the present invention is not limited to the above-described embodiment, and various changes may be made without departing from the spirit of the present invention.
[0054]
【The invention's effect】
In the light-emitting element housing package according to the present invention, a strip-shaped substrate having a plurality of mounting portions for mounting the light-emitting element on the upper surface is positioned below the frame at each of the four corners. It has an arc-shaped notch in plan view cut out over the lower surface, and the side conductor is formed on the inner peripheral surface of the notch, so it is formed on the inner peripheral surface of the arc-shaped notch. When the electrode pad formed on the lower surface of the base is connected to the wiring conductor of the external electric circuit board via solder, the side conductor of the notch and the wiring of the external electric circuit board become large. Since a large solder meniscus is formed between the conductor and the conductor, the bonding strength can be increased.
[0055]
In addition, when each electrode pad on the lower surface of the base is joined to the wiring conductor of the external electric circuit board by solder, a large meniscus of the solder acts to absorb the height variation of the solder between the electrode pads, and The height variation between the electrode pads can be suppressed, and the bonding can be strengthened. Thus, the base can be mounted on the wiring conductor of the external electric circuit board at a precise position in a flat state.
[0056]
In the light-emitting element housing package of the present invention, preferably, two of the four side conductors at one diagonal position of the four side conductors are connected to the driving electrode of the light-emitting element, and two at the other diagonal position are connected to the ground electrode of the light-emitting element. Since the connection is made, when the light emitting device on which the light emitting element is mounted is joined to the wiring conductor of the external electric circuit board by soldering, even if the light emitting device is rotated by 180 ° horizontally from the predetermined arrangement and joined. No displacement occurs, and the predetermined side conductor is joined to the wiring conductor of the external electric circuit. As a result, it is not necessary to check the arrangement of the side conductors of the base every time joining is performed, and the working efficiency can be increased.
[0057]
Further, in the light-emitting element housing package of the present invention, preferably, at least one of the plurality of light-emitting elements is for adjusting luminance of another light-emitting element, and a side surface to which electrodes of the light-emitting element for luminance adjustment are electrically connected. Since the conductor is connected to an external brightness adjusting circuit, when a light emitting element for brightness adjustment is provided for a light emitting element of a predetermined color, the drive voltage, light wavelength, brightness, etc. of the light emitting element for brightness adjustment are adjusted. It can be adjusted separately from the light emitting element of the predetermined color, and the brightness of the predetermined color can be finely adjusted. For example, when three light-emitting elements of blue, green, and red are mounted so that full-color light emission can be performed, three light-emitting elements for adjusting brightness are mounted corresponding to the three light-emitting elements, respectively, and light-emitting elements of three primary colors are provided. Brightness, color intensity, etc., can be finely adjusted, and high-definition full-color display becomes possible.
[0058]
The light emitting device of the present invention has a simple configuration by including the light emitting element housing package of the present invention, the light emitting element mounted on each of the plurality of mounting portions, and the transparent resin covering the light emitting element. It is a high-performance device with high luminous efficiency, can be mounted accurately on the wiring conductor of the external electric circuit board without displacement or inclination, and can be mounted with high bonding strength and high reliability. A plurality of light-emitting elements can be mounted so that high efficiency and full-color light emission can be achieved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of a light emitting element housing package of the present invention.
FIG. 2 is a plan view of the light emitting element housing package of FIG. 1;
3 (a) to 3 (c) are plan views of respective insulating layers of a base in the light emitting element housing package of FIG.
FIG. 4 is a cross-sectional view showing another example of the embodiment of the light emitting element housing package of the present invention.
FIG. 5 is a plan view of the light emitting element housing package of FIG. 4;
6 (a) to 6 (c) are plan views of respective insulating layers of a base in the light emitting element housing package of FIG. 4;
FIG. 7 is a cross-sectional view of a conventional light emitting element storage package.
FIG. 8 is a plan view of another example of a conventional light emitting element storage package.
9 is a cross-sectional view of the light emitting element housing package of FIG. 8 taken along line AA.
[Explanation of symbols]
1: Substrate
1a: mounting part
2: Frame
3: Light emitting element
7: Notch
7a, 7b: side conductor
8a, 8b: electrode pad

Claims

A light emitting element housing package formed by stacking a frame having a through hole surrounding a plurality of the mounting parts on an upper surface of a band-shaped base in which a plurality of mounting parts for mounting light emitting elements on the upper surface are formed in a row. The base has an arc-shaped notch in a plan view, which is located below the frame body and is notched over upper and lower surfaces at each of the four corners, and has an inner periphery of the notch. A side surface conductor is formed on a surface, and an electrode of the light emitting element mounted on the mounting portion is electrically connected to the side surface conductor.

Two of the four side conductors at one diagonal position are connected to the driving electrode of the light emitting element, and two at the other diagonal position are connected to the ground electrode of the light emitting element. The light-emitting element storage package according to claim 1.

At least one of the plurality of light emitting elements is for adjusting luminance of another light emitting element, and the side conductor to which an electrode of the light emitting element for luminance adjustment is electrically connected is connected to an external luminance adjusting circuit. 3. The package for accommodating a light-emitting element according to claim 1, wherein:

A light-emitting element storage package according to any one of claims 1 to 3, a light-emitting element mounted on each of the plurality of mounting portions, and a transparent resin covering the light-emitting element. Light emitting device.