JP4825379B2

JP4825379B2 - Light emitting device

Info

Publication number: JP4825379B2
Application number: JP2001284752A
Authority: JP
Inventors: 悟酒井
Original assignee: Stanley Electric Co Ltd
Current assignee: Stanley Electric Co Ltd
Priority date: 2001-09-19
Filing date: 2001-09-19
Publication date: 2011-11-30
Anticipated expiration: 2021-09-19
Also published as: JP2003092430A

Description

【０００１】
【発明の属する技術分野】
本発明は発光装置に関し、特に半導体発光素子を組み込んだ発光装置に関する。詳しくは発光ダイオード（以下、ＬＥＤという。）などの半導体発光素子と蛍光材料とを組合わせて、蛍光材料による放出光を利用して白色発光などを行う発光装置に関するものである。
【０００２】
【従来の技術】
ＬＥＤなどの半導体発光素子と蛍光体を組合わせた発光装置は、長寿命な発光装置として広く用いられはじめており、例えば液晶のバックライト光源として白色発光ＬＥＤが使われるなど、様々な用途が期待されている。
【０００３】
図１０は、従来の白色発光のＬＥＤ発光装置の一例を示す断面図であり、プリント基板等の上にＬＥＤ発光装置を載置する所謂、面実装型のＬＥＤ発光装置の例を示す。ＬＥＤ発光装置９０は図１０（Ａ）に示すように、ＧａＮ系化合物半導体等からなる青色発光ＬＥＤチップ９１と、ＬＥＤチップ９１を搭載する凹部９２を中央に備えた基部９３と、凹部９２内に充填された透光性樹脂９４とからなる。また、透光性樹脂９４には、ＬＥＤチップ９１から放射された光の一部を吸収して黄色系の光を放出する蛍光体９５が分散混入されている。また、基部９３の外周面および凹部９２内面には一対の外部接続電極９６、９６が設けられ、凹部９２内においてＬＥＤチップ９１と金属ワイヤーで電気的に接続されている。
このＬＥＤ発光装置９０においては、ＬＥＤチップ９１から放射された光の一部が透光性樹脂９４内に分散している蛍光体９５に吸収され、蛍光体９５は黄色系の光を放出する。これによりＬＥＤチップ９１の青色光と蛍光体９５の黄色系の光が同時に発光装置９０から照射され、白色系の発光色を得ることが可能になる。
【０００４】
また、透光性樹脂９４内に蛍光体を分散させた場合には、蛍光体の分布むらが生じやすいため色むらが発生することがある。そこで、図１０（Ｂ）に示したように、蛍光体９５を含まない透光性樹脂９４’にてＬＥＤチップ９１を封止し、その上に蛍光体９５を含有する樹脂層９７を均一な厚みとなるように形成するものもある。
このような青色発光ＬＥＤと蛍光物質とにより青色ＬＥＤからの発光を色変換させて白色発光を可能とした発光装置としては、例えば特開平５−１５２６０９号、特開平７−９９３４５号、特開平１１−３１８４５号、特開２０００−１５６５２８号公報などがある。
【０００５】
【発明が解決しようとする課題】
しかしながら、上記の従来の技術では、ＬＥＤチップ９１からの直接の放射光を受けて蛍光体９５にて色変換された光および反射されたＬＥＤ光は、更に別の蛍光体９５に到達して多重反射を繰り返しながら蛍光体を含有する透光性樹脂層９４を通過した後に外部に取出されるため、減衰が大きく、波長変換効果が十分に得られないという問題点があった。
【０００６】
本発明は以上の点に鑑み、蛍光材料による波長変換効率の優れた、明るい発光装置およびその製造方法を提供することを主たる目的とする。
【０００７】
【課題を解決するための手段】
上記目的は、本発明の請求項１の発明によれば、発光素子と、発光素子に給電する電極と、該発光素子の放射光を吸収して異なる波長の光を放出する波長変換材料層と、これらを一体化する透光性材料とを備えた発光装置において、上記波長変換材料層は、上記透光性材料内で発光素子の主光放射方向に対して傾斜して設けられており、発光素子から照射された光の反射光路側の主光出射面から波長変換光を取り出すようにされており、上記発光装置が、上記波長変換材料層の表面側および裏面側のそれぞれの方向から光を照射する少なくとも２個以上の発光素子を備え、上記波長変換材料層は、発光素子から照射された光により励起されて異なる波長の光を放出する蛍光材料を含み、上記波長変換材料層の表面側もしくは裏面側から照射された励起光を波長変換して、その反射光路側へ放射すると共に、当該波長変換材料層を通過する光路側へ放射する厚みとされていることを特徴とする発光装置、により達成される。
【０００８】
この請求項１の発明では、発光素子の放射光を、その主光放射方向に対して傾斜した波長変換層を形成しているので、発光素子から放射される発光強度の強い光が波長変換材料層に含まれる蛍光体などの波長変換物質によって波長変換された後、その波長変換光の大部分が他の波長変換物質に吸収、反射されることなく発光装置の光出射面に向かって進行する。よって、従来例にて説明した蛍光材料含有層を通過して光を取出すＬＥＤ発光装置に比べて、減衰することなく波長変換光を取出すことができ得る。
【０００９】
本発明の請求項２の発明によれば、上記発光装置が略直方体形状をなし、その対向する一対の面のそれぞれには発光素子が搭載され、主光放射方向が向かい合うように配設されており、上記波長変換材料層は、発光素子を搭載した面の両方に対し傾斜して接する傾斜面に沿って形成されている、ことを特徴とする請求項１に記載の発光装置、により上記した目的は達成される。
この請求項２の発明では、複数の発光素子からの放射光が同一の波長変換材料層に照射され、波長変換された後、その波長変換光の大部分が他の波長変換物質に吸収、反射されることなく光出射面に向かって進行する。よって、従来例にて説明した蛍光材料含有層を通過して光りを取出すＬＥＤ発光装置に比べて、効率よく波長変換光を取出すことができ、明るい発光装置を得ることができ得る。
また、本発明の請求項３から請求項５の発明によっても、従来例にて説明した蛍光材料含有層を通過して光りを取出すＬＥＤ発光装置に比べて、減衰の少ない、効率の良い波長変換光を取出すことができる、明るい発光装置を得ることができ得る。
【００１０】
また、本明細書に記載の製造方法の発明によれば、発光素子と、発光素子に給電する電極と、該発光素子の放射光の主光放射方向に対して傾斜して設けられており、放射光を吸収して異なる波長の光を放出する波長変換材料層と、これらを一体化する透光性材料とを備えた直方体形状の面実装型発光装置の製造方法であって、直方体の１面に相当する矩形とされ、発光素子の正負電極を電気的に接続した電極基板を作製する工程と、直方体を略２分割する傾斜面に沿って切断した形状に相当するキャビティを有するモールド型に電極基板をインサートする工程と、上記キャビティ内に透光性材料を充填し、その表面に波長変換材料層を形成する工程と、波長変換材料層を介して上記キャビティ同士が対向するようにモールド型を重ねて一体化させ、直方体形状の発光装置の複数を作製する工程と、を順に実施することを特徴とする面実装型発光装置の製造方法、により上記した目的は達成される。
この発明によれば、均一な厚みに制御された波長変換材料層を備える面実装型発光装置を、比較的簡単な方法で得ることができ得る。
【００１１】
【発明の実施の形態】
以下、この発明の好適な実施形態を図１乃至図８を参照しながら、詳細に説明する。図１および図２は本発明による発光装置の一実施形態を示す。なお、この実施形態は所謂面実装型もしくはチップ部品タイプと称されるＬＥＤ発光装置に適用したものである。
【００１２】
面実装型ＬＥＤ発光装置１０は、直方体形状をなしており、対向する両側面に放射方向が向かいあうように配置されたＧａＮ系半導体からなる２個のＬＥＤチップ１，１と、このＬＥＤチップ１の間に位置するように対角の辺７ａ，７ｂを結ぶ平面に形成した蛍光材料含有層７と、これらを封止する透光性樹脂４と、により構成される。
【００１３】
ＬＥＤチップ１は、蛍光材料を励起可能なものであり、青色および／または紫外光を放射するものが好ましい。このような半導体発光素子としては、例えばＧａＮ，ＩｎＧａＮ，ＩｎＧａＡｌＮ，ＡｌＧａＮ等の窒化ガリウム系化合物、ダイヤモンド等を発光層として形成させたものを用いることができる。ＬＥＤチップ１は後述する電極基板６に搭載され、金属ワイヤーにより電気的に接続されており、電極基板６と反対側の方向に向かって光を放射するようにされている。
【００１４】
蛍光材料含有層７は、ＬＥＤチップ１から放射された光により励起されて発光する蛍光体等の蛍光材料を含有した層で、蛍光体８を接着剤により透光性樹脂４に接着させて塗付したり、蛍光体８を高密度に分散させた樹脂層を塗付したりすることにより均一な厚みの層状に形成している。蛍光材料は、励起光源であるＬＥＤチップから放射される光や、ＬＥＤ発光装置の用途等に応じた所望の発光色に応じて種々の公知の蛍光材料から適宜選択することができる。具体的な蛍光材料としては、セリウムで付活されたイットリウム・アルミニウム・ガーネット系蛍光体、セリウムで付活されたイットリウム・アルミニウム・ガーネット系蛍光体にプラセオジウムをドープした蛍光体、赤色に変換するＬａ_２Ｏ_２蛍光体、緑色に変換する３Ｂａ０・８Ａｌ_２Ｏ_３蛍光体および青色に変換するＳｒ_１０（ＰＯ_４）_６Ｃ_１２蛍光体およびこれらを混合した混合蛍光体などがある。
【００１５】
また、蛍光材料含有層７は、各々のＬＥＤチップ１からの主照射方向に対して傾斜面を形成する。そのため、この実施形態では、直方体形状のＬＥＤ発光装置１０のＬＥＤチップ１，１を配置した面の対角する辺７ａ、７ｂを通る平面に沿って形成している。これにより、各々のＬＥＤチップ１から放射された光は蛍光材料含有層７にて反射して、傾斜面と対向する平面である紙面上方向および下方向の面４ａおよび４ｂに向かって波長変換された光を主に放射するようになる。蛍光材料含有層７の厚みは、蛍光材料が面内方向で均一に分布すればよいので、蛍光材料の厚み程度の薄さでも良く、好ましくは複数の蛍光材料が厚み方向においても数個分布するように蛍光材料の平均粒径の２〜８倍とする。蛍光材料含有層７の厚みが薄すぎると波長変換の効率が乏しく、また、反射せずに透過する光が増加する。逆に厚すぎると材料コストが高くなる割には波長変換効率がほとんど変わらないからである。なお、ＬＥＤチップからの光の強度によって異なるが、蛍光材料含有層７の厚みを上述した程度にした場合には、一方のＬＥＤチップ１からの光が蛍光材料含有層７により反射する側の光路Ｌ１を経た波長変換光と、蛍光材料含有層７を通過する側の光路Ｌ２を経た波長変換光がＬ１＞Ｌ２の割合で発生し、同様に他方のＬＥＤチップ１からの光が蛍光材料含有層７により反射する側の光路Ｌ１’を経た波長変換光と、蛍光材料含有層７を通過する側の光路Ｌ２’を経た波長変換光がＬ１’＞Ｌ２’の割合で発生する。よって、主光出射面４ａ側においては波長変換光としてＬ１＋Ｌ２’の合成光を得ることができ、同様に主光出射面４ｂ側においては波長変換光としてＬ１’＋Ｌ２の合成光を得ることができるので、発光装置全体の光取出し効率を高めることができ得る。
【００１６】
透光性樹脂４は、ＬＥＤチップ１および蛍光材料含有層７を封止し、側面に電極基板６に設けた電極が露出するようにして６面体の直方体形状のパッケージを形成している。また、主光出射面となる４ａおよび４ｂの表面を粗面化して、内部反射しにくいようにして光の取り出し効率を高めることが好適である。
なお、透光性樹脂４は、ＬＥＤチップ１などを一体化するパッケージとして成形しやすく、ＬＥＤチップと外部とを電気的に絶縁でき、透過率が高い材料が好ましく、更に好ましくはＬＥＤチップ１等との密着性に優れると共に耐熱性などの信頼性に優れる材料が良い。具体的な材料例としては、エポキシ樹脂、ポリカーボネート樹脂、アクリル樹脂、シリコーン樹脂などが挙げられるが、用途に応じて種々の材料の中から適宜選択できる。また、ＬＥＤチップ１周辺をシリコーン樹脂等の熱膨張係数が小さく柔らかな材料とし、直方体の外殻を硬度の高いエポキシ樹脂等の材料とする等の積層構造のものとしても良い。このような積層構造にすれば、ＬＥＤチップ１に比較的大きな電流を流した場合においても、ＬＥＤチップの発熱により透光性樹脂にクラックが生じたり、ＬＥＤチップの発光効率が低下する問題が低減され、より信頼性の高い発光装置を得ることができ得る。また、ＬＥＤチップ１として紫外線を主発光ピークとする発光素子を用いた場合など、ＬＥＤチップからの放射光による透光性樹脂４の光劣化が顕著な場合には、樹脂に代えてガラス、セラミック等の無機材料よりなる透光性材料にてパッケージしても良い。
【００１７】
ここで、本実施形態のＬＥＤ発光装置１０の製造方法について図３および図４を用いて簡単に説明する。
【００１８】
初めに電極基板準備工程について説明する。図４はＬＥＤチップ１を搭載した電極基板６の要部断面図であり、（Ａ）はワイヤ接続、（Ｂ）はＬＥＤチップの図示しない基板側から光を取出すようにして取り付けたフリップチップ接続の例である。
図４（Ａ）において電極基板６は、第一外部接続電極２ａおよび第二外部接続電極２ｂからなる一対の電極２間に、絶縁性材料からなる基体５が位置するようにして、接着テープ９上に貼付する。その後、基体５上にＬＥＤチップ１を絶縁性の接着剤等で固定し、ＬＥＤチップ１の光出射面側に設けられた正負電極の各々と両電極２ａ，２ｂの夫々とを金属ワイヤ３にてボンディングして電気的に接続する。
外部接続電極２は、比較的大きな電流を流すことができ、かつ、放熱性を高めるために、基体５よりも厚くした金属板により形成することが好ましい。また、図１に示したようにＬＥＤチップ１を囲むように第一外部接続電極２ａをＬ字形状、第二外部接続電極２ｂを略矩形状に形成して面積を大きくして、放熱性およびプリント基板等に本発光装置１０を取り付けるときの接続性を高めると良い。なお、基体５の厚みはＬＥＤチップ１と接続する金属ワイヤ３のループ形状にかかる負荷ができる限り小さくなるように、ＬＥＤチップ１の光出射面の高さと外部接続電極２の高さが略同一となるようにすることが好適である。基体５は熱伝導性に優れた絶縁性材料により形成することが好ましく、基体全体が絶縁性材料からなるものでなくても良い。例えば外部接続電極２ａ，２ｂとの界面領域に絶縁膜として酸化膜を形成したシリコンなども用いることができる。
なお、図４（Ｂ）のフリップチップ接続とした電極基板６の場合には、ＬＥＤチップの図示しない基板側が基体５と反対側に位置するようにして載置し、ＬＥＤチップ１の正負電極の各々を金属バンプ３’等を用いて外部接続電極２ａ、２ｂ上に電気的に接続している。これによりＬＥＤチップ１からの発光は図示しないＬＥＤの基板を通して放射される。なお、他の点はワイヤ接続と同様であるのでここでの説明は省略する。
【００１９】
次にＬＥＤ発光装置１０のパッケージ工程について説明する。最初に直方体形状のパッケージを上述した対角する辺７ａ，７ｂを通る平面、即ち蛍光材料含有層７を形成する面にて切断して直方体を略２分割した形状である五面体に相当するキャビティ２３を形成したモールド型２２を用意し、側面に相当する位置に上述した電極基板準備工程にてＬＥＤチップ１を配設しておいた電極基板６を設置する（図３（Ａ））。
続いてキャビティ２３内に溶解した透光性樹脂を塗付もしくは注入して、透光性樹脂４をインサート成形する。次にその表面に蛍光体８を含有する接着剤樹脂等を均一な厚みに塗付して蛍光材料含有層７を形成する（図３（Ｂ））。
次に、蛍光材料含有層７を介してキャビティ２３同士が対向して直方体のパッケージとなるように位置決めしてモールド型２２，２２を貼り合わせる（図３（Ｃ））。なお、本貼り合わせ工程は、いずれか一方に蛍光材料含有層７を形成したモールド型を用い、他方のモールド型表面に蛍光材料含有層７を形成しないものを用いても良い。
最後に、モールド型２２から取出し、直方体のＬＥＤ発光装置１０の夫々に分割することで、複数の面実装型ＬＥＤ発光装置１０を容易に得ることができる。
【００２０】
面実装型ＬＥＤ発光装置１０は、以上のように構成されており、ＬＥＤチップ１から放射された光は蛍光材料含有層７に到達し、少なくとも一部の光が波長変換された後にＬＥＤチップ１の光放射方向と異なる方向である略９０度上方および略９０度下方である主光出射面４ａ、４ｂに向かって、異なる波長の光を放出する。
本実施形態によれば、ＬＥＤチップ１の主光放射方向に対して傾斜した蛍光材料含有層７を形成しているので、ＬＥＤチップ１の発光強度の強い光が蛍光材料にて波長変換された後、その波長変換光の大部分が他の蛍光材料に吸収、反射されることなく光出射面に向かって進行する。よって、従来例にて説明した蛍光材料含有層を通過して光りを取出すＬＥＤ発光装置９０に比べて、効率よく波長変換光を取出すことができ得る。さらに、波長変換材料層７の表面および裏面の双方から照射するように少なくとも２個のＬＥＤチップ１を設けているので、ＬＥＤ発光装置１０の両側に光を取出すことができ得る。また、主に蛍光材料含有層７による反射光を利用しているので、従来の蛍光材料含有層を通過して光りを取出す場合に比べて、厚みによる色むらの影響を受け難くなり色むらが生じにくくなる。
【００２１】
第２の実施形態について、要部断面図である図５を用いて説明する。
【００２２】
第２の実施形態の発光装置２０において、上記第１の実施形態と異なる点は、発光装置のパッケージ周囲に反射部材２１を設けている点である。反射部材２１は一方の主光出射面４ｂと、４ｂと直交する電極基板６を設けていない側面の透光性樹脂４の露出面の表面に形成して、他方の主光出射面４ａ側から光を取出すようにしたものである。反射部材２１は、例えばチタン酸バリウム等白色材料を分散させた樹脂層や、銀等の金属を蒸着した反射フィルムを貼付したりすることにより形成することができる。また、反射部材に蓄光材料を混合させることで、蓄光材料に蓄えられた光による発光を呈するＬＥＤ発光装置を得ることもでき得る。
また、蛍光材料含有層７の厚みを、一方のＬＥＤチップ１（図面の場合には左側のＬＥＤチップ）から放射された光により励起されて蛍光材料から放出する波長変換光が、蛍光材料含有層７を通過して主光照射面４ａにも向かうように薄く形成している。
【００２３】
本実施形態によれば、一方の主光出射面４ｂ側に向かった光は反射部材２１により反射され、蛍光材料含有層７を通過して主光照射面４ａに向かう。また、蛍光材料含有層７と直交する側方側に設けた反射部材２１に到達した光も反射して、その一部が主光照射面４ａに向かう。従って、主光出射面４ａから照射される光量を第１の実施形態の発光装置に比べて増大させた発光装置を得ることができ得る。
また、本実施形態のＬＥＤ発光装置２０において、発光装置のパッケージを作成した後に反射部材２１を周囲に貼付した場合には、蛍光材料含有層７を介して貼り合わせて形成したパッケージの接着強度を向上せしめて、強固な面実装型の発光装置２０を得ることができ得る。
【００２４】
第３の実施形態について、図６から図８を用いて説明する。
【００２５】
第３の実施形態のＬＥＤ発光装置３０において、上記第１の実施形態と異なる点は、発光装置の一方の主光出射面である４ｂに一対の電極３１ａ、３１ｂからなる外部接続用電極３１を設けている点である。底面側外部接続用電極３１ａ、３１ｂは金属フィルム等からなり、図７に示すように電極基板６の外部接続用電極２ａ，２ｂの夫々と一体とされており、ＬＥＤ発光装置３０の底面に露出するようにして設ける。
【００２６】
このようなＬＥＤ発光装置３０は、図８に示したパッケージ工程の概略説明図に従って製造することができ得る。
【００２７】
まず、直方体形状のパッケージを上述した対角する辺７ａ，７ｂを通る平面、即ち蛍光材料含有層７を形成する面にて切断した五面体形状に相当する複数のキャビティ３３を形成したモールド型３２を用意する。このとき、キャビティ３３ａ内の底面側外部接続用電極３１ａ、３１ｂに対応する位置には溝３４が形成され、溝を形成していない先の実施形態と同一形状のキャビティ３３ｂとが交互に形成されている。溝３４は、電極基板３６から延びた底面側外部接続用電極３１ａ、３１ｂを折り曲げて所定位置に配設すると共に、発光装置３０において底面側外部接続用電極３１ａ、３１ｂが僅かに突出して、図示しないプリント基板等の上に取り付ける際に半田付けが容易に行えるようにするために形成しているものである。次にその溝３４を形成したキャビティ３３ａには底面側外部接続用電極３１ａ、３１ｂが位置するようにして電極基板３６を設置し、他のキャビティ３３ｂには底面側外部接続用電極３１ａ、３１ｂが接続されていない先の実施例と同一の電極基板６を設置する（図８（Ａ））。
続いてキャビティ３３内に溶解した透光性樹脂を塗付もしくは注入して、透光性樹脂４を形成してインサート成形する。次にその表面に蛍光体８を含有する接着剤樹脂等を均一な厚みに塗付して蛍光材料含有層７を形成する（図８（Ｂ））。
次に、蛍光材料含有層７を向かい合わせて、キャビティ３３ａと３３ｂとが対向して直方体のパッケージとなるように位置決めしてモールド型３２を貼り合わせ、主光出射面である４ｂ側のみに電極が位置するようにする（図８（Ｃ））。なお、本貼り合わせ工程は、いずれか一方に蛍光材料含有層７を形成したモールド型を用い、他方のモールド型表面に蛍光材料含有層７を形成しないものを用いても良い点は先の実施形態と同様である。
最後に、モールド型３２から取出し、複数の直方体のパッケージに分割して、複数の面実装型ＬＥＤ発光装置３０を容易に得ることができる。
【００２８】
本実施形態によれば、面実装型の発光装置３０のパッケージ底面側にも電極が形成されているので、図示しないプリント基板等に搭載した場合に搭載基板の法線方向に容易に光を照射することができ得る。なお、底面側外部接続用電極３１ａ、３１ｂは一方のＬＥＤチップ１としか接続していないが、これを他方のＬＥＤチップの外部接続用電極の夫々と電気的に接続させることで、２個のＬＥＤチップを直列的にもしくは並列的に接続しても良い。この場合には底面側外部接続用電極３１ａ、３１ｂに接続するのみで少なくとも２個のＬＥＤを同時に点灯することが可能となり得る。
【００２９】
尚、上記した実施形態は、本発明の好適な具体例であるから、技術的に好ましい種々の限定が付されているが、本発明の範囲はこれらの態様に限られるものではない。例えば図９に示すように、蛍光材料含有層４７の幅を狭いものとしてＬＥＤ発光装置４０の側面に蛍光材料含有層４７が露出しないようにして透光性樹脂による封止性能を向上させたり、光出射面に紫外線吸収膜もしくはフィルタ層４１を設ける、などの種々の変更も本発明に包含される。
【００３０】
更に、上述した各実施形態においては２個のＬＥＤチップを用いる例を示したが、主光出射面に向かって蛍光材料含有層による反射光を照射する側のＬＥＤチップのみを用いたもの（例えば、各実施形態における断面図において右側のＬＥＤチップ１）とすることもできる。この場合においても、最も発光強度の強いＬＥＤ放射光が、蛍光材料にて波長変換された後に更に他の蛍光材料に吸収、反射されることなく断面図にて上方側の主光照射面４ａから外部に導出される。よって、減衰の少ない波長変換光を取出すことができ得る。なお、使用する発光素子として２個以上の発光素子を並設したものを用いるなどの変更も当然に本発明に包含される。
【００３１】
【発明の効果】
以上述べたように、本発明によれば発光素子の主光放射方向に対して傾斜した波長変換材料層を形成しているので、発光素子から放射された最も発光強度の強い光が波長変換材料層にて波長変換された後、その波長変換光の大部分が他の波長変換材料に吸収、反射されることなく光出射面に向かって進行する。よって、従来例にて説明した蛍光材料含有層を通過して光を取出すＬＥＤ発光装置に比べて、蛍光材料含有層を通過して減衰した光を取出すのではないので、効率よく波長変換光を取出すことができ得る。また、波長変換材料層による反射光側から主に光を取出しているので、波長変換材料層を透過する場合における厚みむらに起因する色むらの問題が大幅に軽減される。また、蛍光体などの波長変換材料を用いた面実装型の発光装置を簡単に得ることができ得る、といった顕著な効果を奏する。
【図面の簡単な説明】
【図１】本発明による第一の実施形態の面実装型ＬＥＤ発光装置の斜視図である。
【図２】図１の面実装型ＬＥＤ発光装置の断面を示す説明図である。
【図３】本発明による面実装型ＬＥＤ発光装置の製造工程を順に説明する概略断面図である。
【図４】電極基板の要部を説明する概略断面図。（Ａ）はワイヤ接続（Ｂ）はフリップチップ接続の例である。
【図５】本発明による第二の実施形態の面実装型ＬＥＤ発光装置を示す説明図。（Ａ）は斜視図（Ｂ）は要部断面図である。
【図６】本発明による第三の実施形態の面実装型ＬＥＤ発光装置を示す説明図。（Ａ）は斜視図（Ｂ）は要部断面図である。
【図７】本発明による第三の実施形態の電極基板の要部を説明する概略断面図である。
【図８】本発明による第三の実施形態の面実装型ＬＥＤ発光装置の製造工程を順に説明する概略断面図である。
【図９】本発明による更に他の実施形態の面実装型ＬＥＤ発光装置の斜視図である。
【図１０】従来の面実装型ＬＥＤ発光装置を示す概略断面図である。
【符号の説明】
１ＬＥＤチップ
２外部接続電極
３金属ワイヤ
４透光性樹脂
５基体
６，３６電極基板
７，４７蛍光材料含有層
８蛍光体
９接着テープ
１０，２０，３０，４０ＬＥＤ発光装置
２１反射部材
２２，３２モールド型
２３，３３キャビティ
３１底部側外部接続電極
３４溝
９０面実装型ＬＥＤ発光装置
９１ＬＥＤチップ
９２凹部
９３基部
９４透光性樹脂
９５蛍光体
９６電極
９７蛍光体含有樹脂層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light emitting device, and particularly to a light emitting device incorporating a semiconductor light emitting element. Specifically, the present invention relates to a light-emitting device that combines a semiconductor light-emitting element such as a light-emitting diode (hereinafter referred to as an LED) and a fluorescent material to emit white light using light emitted from the fluorescent material.
[0002]
[Prior art]
Light-emitting devices that combine phosphors and semiconductor light-emitting elements such as LEDs have begun to be widely used as long-lived light-emitting devices. For example, white light-emitting LEDs are used as a backlight light source for liquid crystals, and various applications are expected. ing.
[0003]
FIG. 10 is a cross-sectional view showing an example of a conventional white light emitting LED light emitting device, and shows an example of a so-called surface mount type LED light emitting device in which the LED light emitting device is mounted on a printed circuit board or the like. As shown in FIG. 10A, the LED light emitting device 90 includes a blue light emitting LED chip 91 made of a GaN-based compound semiconductor or the like, a base 93 having a concave portion 92 for mounting the LED chip 91 in the center, and a concave portion 92. It consists of a translucent resin 94 filled. The translucent resin 94 is dispersed and mixed with a phosphor 95 that absorbs part of the light emitted from the LED chip 91 and emits yellow light. Further, a pair of external connection electrodes 96 are provided on the outer peripheral surface of the base portion 93 and the inner surface of the recess 92, and are electrically connected to the LED chip 91 with a metal wire in the recess 92.
In the LED light emitting device 90, a part of the light emitted from the LED chip 91 is absorbed by the phosphor 95 dispersed in the translucent resin 94, and the phosphor 95 emits yellow light. As a result, the blue light of the LED chip 91 and the yellow light of the phosphor 95 are simultaneously irradiated from the light emitting device 90, and a white light emission color can be obtained.
[0004]
In addition, when the phosphor is dispersed in the translucent resin 94, uneven distribution of the phosphor is likely to occur, and thus uneven color may occur. Therefore, as shown in FIG. 10B, the LED chip 91 is sealed with a translucent resin 94 ′ not including the phosphor 95, and a resin layer 97 containing the phosphor 95 is uniformly formed thereon. Some are formed to have a thickness.
Examples of light emitting devices that enable white light emission by color-converting the light emitted from the blue LED with such a blue light emitting LED and a fluorescent material include, for example, Japanese Patent Laid-Open Nos. 5-152609, 7-99345, and 11 -31845, JP-A 2000-156528, and the like.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional technique, the light that is directly converted from the LED chip 91 and subjected to color conversion by the phosphor 95 and the reflected LED light reach another phosphor 95 and are multiplexed. Since it is taken out outside after passing through the translucent resin layer 94 containing a phosphor while repeating reflection, there is a problem that attenuation is large and a wavelength conversion effect cannot be sufficiently obtained.
[0006]
In view of the above, it is a main object of the present invention to provide a bright light-emitting device having excellent wavelength conversion efficiency using a fluorescent material and a method for manufacturing the same.
[0007]
[Means for Solving the Problems]
  According to the first aspect of the present invention, the object is to provide a light emitting element, an electrode for supplying power to the light emitting element, a wavelength conversion material layer that absorbs radiated light of the light emitting element and emits light of different wavelengths, and In the light emitting device including the translucent material that integrates them, the wavelength conversion material layer is provided to be inclined with respect to the main light emission direction of the light emitting element in the translucent material, Wavelength converted light is extracted from the main light exit surface on the reflected light path side of the light emitted from the light emitting element.The light emitting device includes at least two or more light emitting elements that irradiate light from respective directions of the front surface side and the back surface side of the wavelength conversion material layer, and the wavelength conversion material layer is irradiated from the light emitting element. Including a fluorescent material that is excited by light and emits light of different wavelengths, converts the wavelength of the excitation light irradiated from the front surface side or the back surface side of the wavelength conversion material layer, and radiates it to the reflected light path side, and The thickness of radiation to the optical path passing through the wavelength conversion material layerIt is achieved by a light emitting device characterized by comprising:
[0008]
In the first aspect of the invention, since the wavelength conversion layer in which the emitted light of the light emitting element is inclined with respect to the main light emission direction is formed, the light having a high emission intensity emitted from the light emitting element is converted into the wavelength converting material. After being wavelength-converted by a wavelength conversion material such as a phosphor contained in the layer, most of the wavelength-converted light travels toward the light exit surface of the light emitting device without being absorbed and reflected by other wavelength conversion materials. . Therefore, it is possible to extract the wavelength-converted light without being attenuated as compared with the LED light-emitting device that extracts light through the fluorescent material-containing layer described in the conventional example.
[0009]
According to invention of Claim 2 of this invention, the said light-emitting device isIt has a substantially rectangular parallelepiped shape, and a light emitting element is mounted on each of a pair of opposed surfaces thereof, and is arranged so that the main light emission directions face each other. The wavelength conversion material layer is formed on the surface on which the light emitting element is mounted. The above-described object is achieved by the light-emitting device according to claim 1, wherein the light-emitting device is formed along an inclined surface that is inclined and in contact with both.
In the invention of claim 2,After the light emitted from a plurality of light emitting elements is irradiated on the same wavelength conversion material layer and converted in wavelength, the light output surface is obtained without the majority of the wavelength converted light being absorbed and reflected by other wavelength conversion materials. Proceed toward. Therefore, compared with the LED light-emitting device that extracts light through the fluorescent material-containing layer described in the conventional example, wavelength-converted light can be extracted efficiently, and a bright light-emitting device can be obtained.
  Further, the claims of the present invention3Claims from5According to the invention, it is possible to obtain a bright light-emitting device capable of taking out wavelength-converted light with less attenuation and efficient as compared with the LED light-emitting device that extracts light through the fluorescent material-containing layer described in the conventional example. Can be.
[0010]
Also bookDescribed in the descriptionAccording to the manufacturing method of the present invention, the light emitting element, the electrode for supplying power to the light emitting element, and the main light radiation direction of the emitted light of the light emitting element are inclined and are different by absorbing the emitted light. A method for manufacturing a rectangular parallelepiped surface-mounted light-emitting device including a wavelength conversion material layer that emits light of a wavelength and a translucent material that integrates the wavelength conversion material layer, and is a rectangle corresponding to one surface of the rectangular parallelepiped A step of producing an electrode substrate in which positive and negative electrodes of a light emitting element are electrically connected, and a step of inserting the electrode substrate into a mold having a cavity corresponding to a shape cut along an inclined surface that substantially divides a rectangular parallelepiped , Filling the cavity with a translucent material, forming a wavelength conversion material layer on the surface, and integrating the molds so that the cavities face each other through the wavelength conversion material layer, Solid rectangular shape Method of manufacturing a surface mounted light emitting device which comprises carrying out the step of fabricating a plurality of devices, in this order, above object is achieved by.
  According to the present invention, it is possible to obtain a surface-mounted light emitting device including a wavelength conversion material layer controlled to have a uniform thickness by a relatively simple method.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2 show an embodiment of a light emitting device according to the present invention. This embodiment is applied to an LED light emitting device called a so-called surface mount type or chip component type.
[0012]
The surface-mounted LED light emitting device 10 has a rectangular parallelepiped shape, and includes two LED chips 1 and 1 made of GaN-based semiconductors arranged so that the radiation directions are opposed to opposite side surfaces, and the LED chip 1 The fluorescent material-containing layer 7 is formed on a plane connecting the diagonal sides 7a and 7b so as to be positioned between the transparent material 4 and the translucent resin 4 for sealing them.
[0013]
The LED chip 1 is capable of exciting a fluorescent material, and preferably emits blue and / or ultraviolet light. As such a semiconductor light emitting device, for example, a gallium nitride compound such as GaN, InGaN, InGaAlN, AlGaN, or the like formed with diamond as a light emitting layer can be used. The LED chip 1 is mounted on an electrode substrate 6 to be described later and is electrically connected by a metal wire so as to emit light in the direction opposite to the electrode substrate 6.
[0014]
The fluorescent material-containing layer 7 is a layer containing a fluorescent material such as a fluorescent material that is excited by the light emitted from the LED chip 1 and emits light, and is applied by adhering the fluorescent material 8 to the translucent resin 4 with an adhesive. Or a resin layer in which the phosphor 8 is dispersed at a high density is applied to form a layer having a uniform thickness. The fluorescent material can be appropriately selected from various known fluorescent materials according to the light emitted from the LED chip, which is an excitation light source, and the desired emission color according to the use of the LED light-emitting device. Specific fluorescent materials include yttrium / aluminum / garnet phosphors activated by cerium, phosphors doped with praseodymium in yttrium / aluminum / garnet phosphors activated by cerium, and La converted to red₂O₂Phosphor, 3Ba0 · 8Al that converts to green₂O₃Sr that converts to phosphor and blue₁₀(PO₄)₆C₁₂There are phosphors and mixed phosphors obtained by mixing these.
[0015]
Further, the fluorescent material-containing layer 7 forms an inclined surface with respect to the main irradiation direction from each LED chip 1. Therefore, in this embodiment, the rectangular LED light emitting device 10 is formed along a plane passing through the opposite sides 7a and 7b of the surface on which the LED chips 1 and 1 are arranged. As a result, the light emitted from each LED chip 1 is reflected by the fluorescent material-containing layer 7 and wavelength-converted toward the upper and lower planes 4a and 4b, which are planes facing the inclined surface. Radiate mainly light. The thickness of the fluorescent material-containing layer 7 may be as thin as the fluorescent material as long as the fluorescent material is uniformly distributed in the in-plane direction, and preferably several fluorescent materials are distributed in the thickness direction. Thus, it is set to 2 to 8 times the average particle diameter of the fluorescent material. If the thickness of the fluorescent material-containing layer 7 is too thin, the wavelength conversion efficiency is poor, and more light is transmitted without being reflected. On the contrary, if the thickness is too large, the wavelength conversion efficiency hardly changes for the material cost. In addition, although it changes with the intensity | strengths of the light from an LED chip, when the thickness of the fluorescent material containing layer 7 is made into the above-mentioned grade, the optical path on the side where the light from one LED chip 1 is reflected by the fluorescent material containing layer 7 The wavelength-converted light that has passed through L1 and the wavelength-converted light that has passed through the optical path L2 on the side passing through the fluorescent material-containing layer 7 are generated at a ratio of L1> L2, and similarly, the light from the other LED chip 1 is emitted from the fluorescent material-containing layer 7 is generated at a ratio of L1 ′> L2 ′. Therefore, L1 + L2 ′ combined light can be obtained as the wavelength-converted light on the main light exit surface 4a side, and similarly L1 ′ + L2 composite light can be obtained as the wavelength-converted light on the main light exit surface 4b side. Therefore, the light extraction efficiency of the entire light emitting device can be increased.
[0016]
The translucent resin 4 seals the LED chip 1 and the fluorescent material-containing layer 7 and forms a hexahedral rectangular parallelepiped package so that the electrodes provided on the electrode substrate 6 are exposed on the side surfaces. In addition, it is preferable to increase the light extraction efficiency by roughening the surfaces of 4a and 4b serving as the main light emitting surfaces so as not to be internally reflected.
The translucent resin 4 is easily formed as a package in which the LED chip 1 and the like are integrated, is preferably a material that can electrically insulate the LED chip from the outside, and has a high transmittance, and more preferably the LED chip 1 and the like. A material that has excellent adhesiveness and excellent reliability such as heat resistance is preferable. Specific examples of the material include an epoxy resin, a polycarbonate resin, an acrylic resin, a silicone resin, and the like, and can be appropriately selected from various materials depending on applications. Alternatively, the LED chip 1 may have a laminated structure in which the periphery of the LED chip 1 is made of a soft material having a small thermal expansion coefficient such as silicone resin and the outer shell of the rectangular parallelepiped is made of a material such as epoxy resin having high hardness. With such a laminated structure, even when a relatively large current is passed through the LED chip 1, cracks in the translucent resin due to the heat generated by the LED chip or reduction in light emission efficiency of the LED chip is reduced. Thus, a more reliable light-emitting device can be obtained. Further, when the LED chip 1 is a light emitting element having an ultraviolet light as a main light emission peak or the like and the light deterioration of the translucent resin 4 due to the emitted light from the LED chip is remarkable, glass or ceramic is used instead of the resin. You may package with the translucent material which consists of inorganic materials, such as.
[0017]
Here, the manufacturing method of the LED light-emitting device 10 of this embodiment is demonstrated easily using FIG. 3 and FIG.
[0018]
First, the electrode substrate preparation process will be described. 4A and 4B are cross-sectional views of the main part of the electrode substrate 6 on which the LED chip 1 is mounted. FIG. 4A is a wire connection, and FIG. 4B is a flip chip connection that is attached so that light is extracted from the substrate side (not shown) It is an example.
In FIG. 4A, the electrode substrate 6 has an adhesive tape 9 such that a base 5 made of an insulating material is positioned between a pair of electrodes 2 made of a first external connection electrode 2a and a second external connection electrode 2b. Stick on top. Thereafter, the LED chip 1 is fixed on the base 5 with an insulating adhesive or the like, and each of the positive and negative electrodes provided on the light emitting surface side of the LED chip 1 and each of the electrodes 2a and 2b is attached to the metal wire 3. Bond and connect electrically.
The external connection electrode 2 is preferably formed of a metal plate thicker than the base 5 in order to allow a relatively large current to flow and to improve heat dissipation. Further, as shown in FIG. 1, the first external connection electrode 2a is formed in an L shape so as to surround the LED chip 1 and the second external connection electrode 2b is formed in a substantially rectangular shape so as to increase the area. It is preferable to improve connectivity when the light emitting device 10 is attached to a printed circuit board or the like. The height of the light emitting surface of the LED chip 1 and the height of the external connection electrode 2 are substantially the same so that the load on the loop shape of the metal wire 3 connected to the LED chip 1 is as small as possible. It is preferable that The base 5 is preferably formed of an insulating material having excellent thermal conductivity, and the entire base may not be made of an insulating material. For example, silicon in which an oxide film is formed as an insulating film in the interface region with the external connection electrodes 2a and 2b can be used.
In the case of the electrode substrate 6 with flip chip connection shown in FIG. 4B, the LED chip is placed so that the substrate side (not shown) of the LED chip is located on the side opposite to the base 5, and the positive and negative electrodes of the LED chip 1 are placed. Each is electrically connected to the external connection electrodes 2a and 2b using a metal bump 3 ′ or the like. As a result, light emitted from the LED chip 1 is radiated through an LED substrate (not shown). Since the other points are the same as those of the wire connection, description thereof is omitted here.
[0019]
Next, the packaging process of the LED light emitting device 10 will be described. A cavity corresponding to a pentahedron having a rectangular parallelepiped shape obtained by first cutting a rectangular parallelepiped package at a plane passing through the diagonal sides 7a and 7b, that is, a plane on which the fluorescent material-containing layer 7 is formed. 3 is prepared, and the electrode substrate 6 in which the LED chip 1 is disposed in the electrode substrate preparation step described above is installed at a position corresponding to the side surface (FIG. 3A).
Subsequently, the translucent resin dissolved in the cavity 23 is applied or injected, and the translucent resin 4 is insert-molded. Next, an adhesive resin or the like containing phosphor 8 is applied to the surface with a uniform thickness to form fluorescent material-containing layer 7 (FIG. 3B).
Next, the molds 22 and 22 are bonded together by positioning so that the cavities 23 face each other through the fluorescent material-containing layer 7 to form a rectangular parallelepiped package (FIG. 3C). In this bonding process, a mold having the fluorescent material-containing layer 7 formed on one of them may be used, and a mold not forming the fluorescent material-containing layer 7 on the surface of the other mold may be used.
Finally, the plurality of surface-mounted LED light-emitting devices 10 can be easily obtained by taking out from the mold die 22 and dividing into the respective rectangular parallelepiped LED light-emitting devices 10.
[0020]
The surface-mounted LED light emitting device 10 is configured as described above, and the light emitted from the LED chip 1 reaches the fluorescent material-containing layer 7, and after at least part of the light is wavelength-converted, the LED chip 1. Light of different wavelengths is emitted toward the main light exit surfaces 4a and 4b which are approximately 90 degrees above and approximately 90 degrees below, which are directions different from the light emission direction.
According to the present embodiment, since the fluorescent material-containing layer 7 inclined with respect to the main light emission direction of the LED chip 1 is formed, the light with strong emission intensity of the LED chip 1 is wavelength-converted by the fluorescent material. Thereafter, most of the wavelength-converted light travels toward the light exit surface without being absorbed and reflected by other fluorescent materials. Therefore, compared with the LED light-emitting device 90 which extracts the light through the fluorescent material-containing layer described in the conventional example, the wavelength-converted light can be extracted efficiently. Furthermore, since at least two LED chips 1 are provided so as to irradiate from both the front surface and the back surface of the wavelength conversion material layer 7, light can be extracted to both sides of the LED light emitting device 10. In addition, since the reflected light mainly from the fluorescent material-containing layer 7 is used, it is less affected by the uneven color due to the thickness, and the uneven color is less than when the light is taken out through the conventional fluorescent material-containing layer. It becomes difficult to occur.
[0021]
A second embodiment will be described with reference to FIG.
[0022]
The light emitting device 20 of the second embodiment is different from the first embodiment in that a reflecting member 21 is provided around the package of the light emitting device. The reflecting member 21 is formed on the surface of the exposed surface of the translucent resin 4 on one side where the electrode substrate 6 orthogonal to the main light emitting surface 4b and 4b is not provided, and from the other main light emitting surface 4a side. The light is taken out. The reflecting member 21 can be formed, for example, by attaching a resin layer in which a white material such as barium titanate is dispersed, or a reflecting film on which a metal such as silver is deposited. Moreover, the LED light-emitting device which exhibits light emission by the light stored in the luminous material can also be obtained by mixing the luminous material with the reflecting member.
The wavelength-converted light that is excited by the light emitted from one LED chip 1 (left LED chip in the case of drawing) and emitted from the fluorescent material is converted into the fluorescent material-containing layer 7 by changing the thickness of the fluorescent material-containing layer 7. 7 is formed thinly so as to pass through the main light irradiation surface 4a.
[0023]
According to the present embodiment, the light directed toward the one main light exit surface 4b is reflected by the reflecting member 21, passes through the fluorescent material-containing layer 7, and travels toward the main light irradiation surface 4a. Moreover, the light which reached | attained the reflection member 21 provided in the side side orthogonal to the fluorescent material content layer 7 is reflected, and the one part goes to the main light irradiation surface 4a. Therefore, it is possible to obtain a light emitting device in which the amount of light irradiated from the main light emitting surface 4a is increased as compared with the light emitting device of the first embodiment.
In addition, in the LED light emitting device 20 of the present embodiment, when the reflecting member 21 is pasted after the light emitting device package is created, the adhesive strength of the package formed by bonding through the fluorescent material containing layer 7 is increased. As a result, it is possible to obtain a strong surface-mounted light emitting device 20.
[0024]
A third embodiment will be described with reference to FIGS.
[0025]
The LED light emitting device 30 of the third embodiment is different from the first embodiment in that an external connection electrode 31 including a pair of electrodes 31a and 31b is provided on 4b which is one main light emitting surface of the light emitting device. It is a point that is provided. The bottom surface side external connection electrodes 31a and 31b are made of a metal film or the like, and are integrated with the external connection electrodes 2a and 2b of the electrode substrate 6 as shown in FIG. To be provided.
[0026]
Such an LED light emitting device 30 can be manufactured according to the schematic explanatory diagram of the packaging process shown in FIG.
[0027]
First, a mold 32 having a plurality of cavities 33 corresponding to a pentahedron shape obtained by cutting a rectangular parallelepiped package on the plane passing through the diagonal sides 7a and 7b, that is, the surface on which the fluorescent material-containing layer 7 is formed. Prepare. At this time, grooves 34 are formed at positions corresponding to the bottom surface side external connection electrodes 31a and 31b in the cavity 33a, and cavities 33b having the same shape as the previous embodiment in which no grooves are formed are alternately formed. ing. The groove 34 is formed by bending the bottom-side external connection electrodes 31a and 31b extending from the electrode substrate 36 at a predetermined position, and the bottom-side external connection electrodes 31a and 31b slightly project in the light emitting device 30. It is formed so that soldering can be easily performed when it is mounted on a printed circuit board or the like. Next, the electrode substrate 36 is set so that the bottom side external connection electrodes 31a and 31b are positioned in the cavity 33a in which the groove 34 is formed, and the bottom side external connection electrodes 31a and 31b are provided in the other cavity 33b. The same electrode substrate 6 as that of the previous embodiment that is not connected is installed (FIG. 8A).
Subsequently, the translucent resin dissolved in the cavity 33 is applied or injected to form the translucent resin 4 and insert molding. Next, an adhesive resin or the like containing phosphor 8 is applied to the surface with a uniform thickness to form fluorescent material-containing layer 7 (FIG. 8B).
Next, the fluorescent material-containing layer 7 is faced, the cavities 33a and 33b are opposed to each other and positioned so as to form a rectangular parallelepiped package, and the mold die 32 is bonded, and an electrode is formed only on the 4b side which is the main light emitting surface. Is positioned (FIG. 8C). In addition, this bonding process uses the mold which formed the fluorescent material content layer 7 in any one, and the point which does not form the fluorescent material content layer 7 in the other mold type surface may be used. It is the same as the form.
Finally, it can be taken out from the mold 32 and divided into a plurality of rectangular parallelepiped packages, so that a plurality of surface-mounted LED light emitting devices 30 can be easily obtained.
[0028]
According to the present embodiment, since the electrode is also formed on the package bottom surface side of the surface mount type light emitting device 30, light is easily irradiated in the normal direction of the mounting substrate when mounted on a printed circuit board (not shown). You can get. The bottom surface side external connection electrodes 31a and 31b are connected only to one LED chip 1, but by electrically connecting them to the external connection electrodes of the other LED chip, LED chips may be connected in series or in parallel. In this case, it may be possible to light at least two LEDs simultaneously by simply connecting to the bottom side external connection electrodes 31a and 31b.
[0029]
The above-described embodiments are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is not limited to these aspects. For example, as shown in FIG. 9, the width of the fluorescent material-containing layer 47 is made narrow so that the fluorescent material-containing layer 47 is not exposed on the side surface of the LED light-emitting device 40, and the sealing performance with a translucent resin is improved. Various modifications such as providing an ultraviolet absorbing film or a filter layer 41 on the light emitting surface are also included in the present invention.
[0030]
Furthermore, in each of the above-described embodiments, an example using two LED chips has been shown. However, only the LED chip on the side that irradiates the reflected light from the fluorescent material-containing layer toward the main light emission surface is used (for example, Moreover, it can also be set as the LED chip 1) of the right side in sectional drawing in each embodiment. Even in this case, the LED emitted light having the strongest emission intensity is wavelength-converted by the fluorescent material and is not further absorbed and reflected by the other fluorescent material, and is reflected from the upper main light irradiation surface 4a in the sectional view. Derived externally. Therefore, it is possible to extract wavelength converted light with little attenuation. It should be noted that changes such as using two or more light emitting elements arranged in parallel as a light emitting element to be used are also included in the present invention.
[0031]
【The invention's effect】
As described above, according to the present invention, since the wavelength conversion material layer inclined with respect to the main light emission direction of the light emitting element is formed, the light having the strongest emission intensity emitted from the light emitting element is the wavelength conversion material. After wavelength conversion by the layer, most of the wavelength converted light travels toward the light exit surface without being absorbed and reflected by other wavelength conversion materials. Therefore, compared with the LED light emitting device that extracts light through the fluorescent material-containing layer described in the conventional example, it does not extract the attenuated light through the fluorescent material-containing layer, so that the wavelength-converted light is efficiently emitted. Can be taken out. Further, since light is mainly extracted from the reflected light side by the wavelength conversion material layer, the problem of uneven color due to thickness unevenness when passing through the wavelength conversion material layer is greatly reduced. In addition, there is a remarkable effect that a surface-mounted light emitting device using a wavelength conversion material such as a phosphor can be easily obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view of a surface-mount LED light emitting device according to a first embodiment of the present invention.
FIG. 2 is an explanatory view showing a cross section of the surface-mounted LED light-emitting device of FIG.
FIG. 3 is a schematic cross-sectional view for sequentially explaining the manufacturing process of the surface-mounted LED light emitting device according to the present invention.
FIG. 4 is a schematic cross-sectional view illustrating a main part of an electrode substrate. (A) is wire connection (B) is an example of flip chip connection.
FIG. 5 is an explanatory view showing a surface-mounted LED light-emitting device according to a second embodiment of the present invention. (A) is a perspective view (B) is a sectional view of the main part.
FIG. 6 is an explanatory view showing a surface-mounted LED light-emitting device according to a third embodiment of the present invention. (A) is a perspective view (B) is a sectional view of the main part.
FIG. 7 is a schematic cross-sectional view illustrating a main part of an electrode substrate according to a third embodiment of the present invention.
FIG. 8 is a schematic cross-sectional view for sequentially explaining the manufacturing process of the surface-mounted LED light emitting device according to the third embodiment of the present invention.
FIG. 9 is a perspective view of a surface-mounted LED light emitting device according to still another embodiment of the present invention.
FIG. 10 is a schematic cross-sectional view showing a conventional surface-mounted LED light-emitting device.
[Explanation of symbols]
1 LED chip
2 External connection electrode
3 Metal wire
4 Translucent resin
5 Base
6,36 electrode substrate
7, 47 Fluorescent material containing layer
8 Phosphor
9 Adhesive tape
10, 20, 30, 40 LED light emitting device
21 Reflective member
22, 32 Mold type
23,33 cavity
31 Bottom side external connection electrode
34 groove
90 Surface-mount LED light-emitting device
91 LED chip
92 recess
93 Base
94 Translucent resin
95 phosphor
96 electrodes
97 Phosphor-containing resin layer

Claims

A light emitting device comprising: a light emitting element; an electrode that feeds the light emitting element; a wavelength converting material layer that absorbs radiation emitted from the light emitting element and emits light of different wavelengths; and a translucent material that integrates them. In
The wavelength conversion material layer is provided in the translucent material so as to be inclined with respect to the main light emission direction of the light emitting element, and has a wavelength from the main light emitting surface on the reflected light path side of the light emitted from the light emitting element. The conversion light is taken out ,
The light-emitting device includes at least two or more light-emitting elements that irradiate light from respective directions of the front surface side and the back surface side of the wavelength conversion material layer,
The wavelength conversion material layer includes a fluorescent material that is excited by light emitted from the light emitting element and emits light having a different wavelength, and converts the excitation light irradiated from the front side or the back side of the wavelength conversion material layer. The light emitting device has a thickness that radiates toward the reflected light path and radiates toward the light path that passes through the wavelength conversion material layer .

The light emitting device has a substantially rectangular parallelepiped shape, and a light emitting element is mounted on each of the opposed pair of surfaces, and is arranged so that the main light emission directions face each other,
The light emitting device according to claim 1 , wherein the wavelength conversion material layer is formed along an inclined surface that is inclined and in contact with both surfaces on which the light emitting element is mounted.

On the surface provided with the light emitting element, a pair of electrodes for supplying power to the light emitting element is formed so as to surround the periphery of the light emitting element, and the electrodes are exposed to the outside to serve as external connection electrodes. The light emitting device according to claim 2 , wherein the light emitting device is a light emitting device.

The light emitting device according to claim 3 , wherein an electrode connected to the external connection electrode is exposed on a surface orthogonal to a surface including the light emitting element of the light emitting device.

The light emitting device is characterized in that it comprises a main light emitting surface of the at least one surface, a surface which is coated with a reflective layer, the light emitting device according to any one of claims 1 to 4.