JP2004342791A

JP2004342791A - Led lamp and led lighting device

Info

Publication number: JP2004342791A
Application number: JP2003136926A
Authority: JP
Inventors: Kunihiro Hattori; 邦裕服部
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-05-15
Filing date: 2003-05-15
Publication date: 2004-12-02
Anticipated expiration: 2023-05-15
Also published as: JP3938100B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED (light emitting diode) lighting device of high reliability wherein property deterioration by increase of current is suppressed, although decline in emission efficiency by temperature rise, chrominance variation by variation of luminescence wavelength and shortening of lifetime are caused when current is increased in the conventional LED lighting device. <P>SOLUTION: A frame (102) for power supply and a heat dissipation plate (103) wherein a hollow (104) whose bottom is flat is formed by performing cutting, press, sintering etc. to thermally conductive material are collectively formed integrally by using non-conductivity adhesive (107), and a heat dissipation frame (figure 4 (not shown)) is constituted. An LED element (106) is mounted on the flat part of the hollow, and the LED element and the frame for power supply are connected with a conductive thin wire (105) such as a gold streak. Resin mould is performed in a form wherein a part (103a) of a surface opposite to an LED element mounting surface of the heat dissipation plate on which the LED element is mounted is exposed. As a result, heat is excluded by using a heat sink or the like from a heat dissipation plate exposed part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、熱による発光効率の低下、および発光波長の変動を抑えた、信頼性の高いＬＥＤ照明具に関するものである。
【０００２】
【従来の技術】
従来から屋外照明灯、警告灯、ディスプレイ装置等の光源として、ＬＥＤディスクリートランプ（５１１）が搭載されている。しかし、複数のＬＥＤランプを集合体として回路基板（５１３）に搭載した場合、個々から発生する熱により灯具全体が高温となり、発光効率の低下、信頼性の低下を招く。その対策として筐体内部へ外気の取り込みの対策、またはＬＥＤディスクリートランプユニットとヒートシンクの空間部をフィラー入り樹脂（５１２）で埋め、熱拡散を期待している（例えば、特許文献１参照）。
【０００３】
しかし、熱の発生源であるＬＥＤチップ搭載部と放熱樹脂（５１２）は断面０．２５ｍｍ^２のリードフレーム（５１１ａ）で繋がっているのみで、放熱効果は極めて悪い。それゆえ、１個当たりのＬＥＤ素子に注入できる電流値は２０ｍＡ程度であり、ＬＥＤランプの密度が大になればより低電流でしか使用できなくなる。
【０００４】
また、ＬＥＤディスクリートランプ（５１１）は回路基板と２本のリードでつながっており、前後または左右のどちらかに傾く可能性があり、集合体として使用する場合は点灯状態で個々の光軸の調整が必要となる欠点がある（図５参照）。
【０００５】
一方、銅箔層（６１７）、絶縁層（６１６）、金属ベース（６１５）の積層基板に絞り加工を施し、絞り加工部分にＬＥＤチップを搭載し、金属ベースの貫通穴を通してＬＥＤチップ搭載側のレンズを保持したＬＥＤユニットの製造法が提案されている（例えば、特許文献２参照）。
【０００６】
しかし、ＬＥＤ素子を搭載した積層金属基板を樹脂で一体成形するため、ユニットとしての光軸のズレは生じないものの、発光部の配置の変更には基板の絞り用金型、レンズ用金型等高額な金型費用が必要となる。また、熱源であるＬＥＤ素子は金属基板と絶縁層を介した回路部に搭載されており、ＬＥＤ素子から金属基板への熱抵抗は大きい。かつ、ＬＥＤ素子から離れた部分の金属ベース部からしか熱の除去ができない問題点がある。（図６参照）。
【０００７】
【特許文献１】特開平０９−２０４５９５号公報（第５頁、図１）
【特許文献２】特開平０６−３３４２２４号公報（第４頁、図１）
【０００８】
【開発が解決しようとする課題】上記のようにＬＥＤ素子で発生した熱の除去が十分でない場合、図９のグラフの従来品Ａおよび従来品Ｂに示すように、低電流値でしか注入電流に比例した光出力が得られず、大電流値では消費電力の無駄が生じると伴に発光素子の寿命も短くなる。また、発光波長についても図１０の従来品Ａおよび従来品Ｂに示すように、ＬＥＤ素子の接合部温度上昇に伴い長波長側にシフトし色調が変化する。
【０００９】
また、紫外線発光素子を励起光源とし蛍光材を間接的に発光させるＬＥＤランプにおいては発光素子の波長変動により蛍光材の発光効率が大きく影響され、期待される光度および色度が得られない問題がある。
【００１０】
【課題を解決するための手段】ＬＥＤ素子を熱伝導度の大きい材料に搭載し、ＬＥＤ素子の接合部で発生する熱を最短距離である裏面から放熱フィン等に伝導させＬＥＤ素子の温度上昇を抑えることで、電流値変化による特性の変動を最小限に抑え、特に大電流での発光効率の低下および寿命の短縮を防止する。
【００１１】
【発明の実施の形態】以下、本発明の実施態様を図に基づいて説明する。図４は本発明にかかるＬＥＤランプに使用するフレームの一例を示す斜視図である。表面側に底辺がフラット４０４ａで傾斜した反射面４０４ｂを備えた窪みと裏面側に本体４０３より小さい径の凸部を形成した熱伝導性材料と給電のためのワイヤーボンド可能なフレーム４０２を接着剤で一体化する。
【００１２】
ちなみに、図４の窪み部分について詳細に説明すると、使用するＬＥＤチップの幅をＷ１とすると、窪み底辺の直径Ｗは、Ｗ１×１．４１＋０．０２ｍｍ≦Ｗ≦Ｗ１×１．４１＋１．０ｍｍが望ましく、さらに望ましくは、Ｗ１×１．４１＋０．１ｍｍ≦Ｗ≦Ｗ１×１．４１＋０．５ｍｍである。
【００１３】
窪みの深さについては、使用するＬＥＤチップの高さをＴとすると、深さＨはＴ≦Ｈ＜Ｔ×５が望ましく、さらに望ましくは、Ｔ×２≦Ｈ≦Ｔ×３である。
【００１４】
また、反射面の広がり角度θは、底面に対し３０°以上が望ましい、さらに望ましくは４５°≦θ≦７５°であり、この範囲外ではレンズ面への取り出し効率が低下する。
【００１５】
次に、本発明の図１について説明する。放熱プレート１０３の窪み部底辺のフラット部１０４ａにＬＥＤチップ１０６を接着樹脂で搭載固定し、ＬＥＤチップ１０６の電極パターンと給電フレームをワイヤーボンドする。上記ＬＥＤチップの搭載された放熱フレームを、ＬＥＤチップ搭載面がレンズ側になるようモールド用型にセットする。なお、望ましくはＬＥＤチップを搭載した窪み部分に事前にシリコン系柔軟樹脂またはモールド材と同じ樹脂を充填しておくと気泡の混入防止に有効である。
【００１６】
続いて、放熱プレ−トの凸部１０３ａが露出するよう透明樹脂を充填する。なお、充填する樹脂は熱硬化、熱可塑のどちらの樹脂を使ってもよい。また、樹脂と凸部段差は、使用する放熱プレートと使用する樹脂の熱膨張係数を考慮し、ＬＥＤ点灯時に放熱プレートの凸部が常に水平、または突出するよう、樹脂充填量を調節しておく。
【００１７】
また、図７は上記本発明のＬＥＤランプを使った一例であり、詳細に説明する。穴を開けたエポキシ回路基板７１３の穴に本発明のＬＥＤランプを配置し、基板の回路とＬＥＤランプの給電フレーム７１２を半田等、導電性材料で接続固定する。次にＬＥＤランプ裏面側の放熱プレートの突出部に熱伝導性樹脂を塗布し、塗布面をヒートシンク等放熱器のフラット面と接触させる。ＬＥＤランプを搭載した基板と放熱器は、熱伝導性樹脂の厚みが薄くなるようネジ、またはリベットにより固定する。
【００１８】
【実施例１】厚さ２ｍｍ、直径５．８ｍｍの銅（還元銅）円板を、表面側に底面１０４ａの直径が０．８ｍｍ、反射面１０４ｂの角度が６０°、深さ０．５ｍｍの窪み、裏面側に直径５．０ｍｍ、段差０．６ｍｍの凸部１０３ａになるようプレス加工した放熱プレートの表面ドーナツ状フラット面に非導電性接着材ムロマックボンドＨ−３３３Ｃを薄く塗布し、プレスで打ち抜き下地に０．３μｍのニッケルめっき、表面に３μｍの銀メッキした給電フレーム１０２を１．０Ｋｇ／ｃｍ^２の加重を掛けた状態で１５０℃の雰囲気で３０分間硬化した。
【００１９】
なお、本実施例では接着強度２４０Ｋｇ／ｃｍ^２を使用したが、硬化後の接着強度が１５０Ｋｇ／ｃｍ^２以上が望ましい。また、非導電性接着剤の塗布はスタンピング方式で行ったが、スクリーン印刷、ディスペンス方式でもよい。硬化時の加重は２．０〜０．５Ｋｇ／ｃｍ^２が望ましく、加重を大きくすると電気絶縁されない場合が生じやすくなる。また、加重をかけない場合には接着材の厚みが不均一となり硬化後の接着強度にバラツキが生じ信頼性が落ちる原因となる。
【００２０】
上記、放熱プレートの窪み底面１０４ａにＬＥＤチップ１０６（チップサイズ０．３２ｍｍ角、チップ高さ０．２２ｍｍ、材質ＧａＮ／サファイヤ）を非導電性接着剤ムロマックボンドＨ３８６で配置固定し、ＬＥＤチップ表面の電極と給電フレーム１０２をφ２５μｍの金線１０５で接続した。ＬＥＤチップの固定に使用する非導電性樹脂は、透明または白色樹脂がより望ましく、着色樹脂は光の吸収によりレンズ面への光の取り出し効率が低下する。また、樹脂の色によっては本来のＬＥＤチップの発光色と異なる色度となる不具合が生じる。
【００２１】
続いて、ＬＥＤチップ搭載の窪み１０４に透明エポキシ樹脂を予備充填し、チップ搭載面側が下側になるよう金型に装着（金型についてもレンズ面が下）。透明エポキシ樹脂を金型と放熱プレート隙間から放熱プレートの凸部１０３ａとフラットになるよう注入し、１２０℃で硬化後、金型から取り外しφ７ｍｍ、高さ５．１ｍｍのＬＥＤランプ１３０を作成した。
【００２２】
なお、紫外線発光ＬＥＤチップを光源として可視光を得る場合は、窪み部１０４に蛍光剤を混和したシリコン樹脂を注入、硬化後に金型に装着すればよい。また、インサート成形等、他の成形方法を用いれば透明ポリカーボネート樹脂、アクリル樹脂等も使用できる。
【００２３】
【実施例２】上記実施例１と同寸法の放熱プレート３０３をアルミニウムの溶融成形で作成し、実施例１と同様の方法で給電フレームと一体化した。本放熱プレートの窪み部に、表面にワイヤーボンド可能なＡｕを蒸着したＡｌＮ（サイズ０．５ｍｍ角、厚み０．１ｍｍ）３０８を熱導電性樹脂で固定し、その上にＬＥＤチップ３０６ａ（チップサイズ０．３２ｍｍ角、チップ高さ０．２５ｍｍ、材質ＡｌＧａＡｓ／ＡｌＧａＡｓ、表面ｎ電極、裏面ｐ電極）を導電性接着剤ムロマックボンドＡ−７１Ｓで接着した。つづいて、表面ｎ電極と給電フレーム３０２をφ２５μｍの金線３０５ａで接続し、もう片方の給電フレーム３０２とＡｌＮ（３０８）をφ２５μｍの金線３０５ｂで接続した。本実施例では２００Ｗ／ｍ・ＫのＡｌＮを使用したが、熱伝導度が１５０Ｗ／ｍ・Ｋ以上の材料であれば特に問題は生じなかった。
【００２４】
上記ＬＥＤチップを搭載した放熱プレートの窪み部に透明シリコン樹脂を充填、熱硬化後、放熱プレートの凸部フラット表面に樹脂が回り込まないよう設計された金型にセットし、透明ポリカーボネート樹脂を金型温度１６０℃、樹脂温度２８０℃の条件でインサート成形しＬＥＤランプ１３０を作成した。
【００２５】
【実施例３】φ７ｍｍの穴を開けたエポキシ回路基板７１３の穴部に、実施例１で作成した本発明のＬＥＤランプ７３０をはめ込み、基板上の回路とＬＥＤランプの給電フレームをハンダにより接続した。次に、本ＬＥＤランプの搭載された基板裏面に現われる放熱プレートのフラット部１０３ａに熱伝導性材料７１８（信越化学工業製オイルコンパウンドＧ７５１）を塗布し、ヒートシンクに搭載した。ＬＥＤランプの搭載された基板とヒートシンクはタッピングネジで固定の後、ＬＥＤランプ搭載面のレンズ部を除いて防湿樹脂７１２（東芝シリコンＴＳＥ３９９）を塗布し、ＬＥＤ照明具を作成した。本実施例では熱伝導率４．５Ｗ／ｍ・Ｋのアルミナ混和シリコンオイルを使用したが、熱伝導性材料の膜厚が０．１ｍｍ以下で固定できれば２．０Ｗ／ｍ・Ｋの熱伝導率でも十分特性は確保できた。
【００２６】
【実施例４】内側に半径１５ｍｍの反射面および集光レンズ８２２を備えたヘッド部と放熱効率を向上させるため、外形２０ｍｍ、厚み２ｍｍの７枚のフィンを備えたヒートシンクをアルミニウム材で作成した。次に、実施例１で作成した本発明のＬＥＤランプの給電プレート１０２の＋極にケーブルを接続し、放熱プレートの凸部１０３ａに熱伝導性材料８１８（ＡＯＳ製５４０１２、熱伝導率２．５８Ｗ／ｍ・Ｋ）を塗布、ＬＥＤランプのレンズ側がヘッド部側になるようＬＥＤランプをセットした。一方ＬＥＤランプの他方の給電フレーム（−極）はヒートシンクと接触させ、ヘッド部をヒートシンクにねじ込みＬＥＤ照明具を作成した。
【００２７】また、導電性金属筐体に本実施例のＬＥＤ照明具を多数個配置した照明具の場合、制御回路の−極を筐体に接続することで煩雑な配線が不要となる。
【００２８】
【比較例１】実施例３の方法で、本発明のＬＥＤランプ２２４個を、７個直列３２並列の電気回路で、従来品と同じ同心円状に配置したＬＥＤ照明具を作成した。本比較例を点灯させＬＥＤランプ１個に流れる電流値を基準に、ディスクリートランプを搭載した従来品Ａ、金属積層基板を用いた従来品Ｂと比較した。図９、図１０に示すように、従来品Ａは３０ｍＡ付近まで比例的に出力は増加するものの、５０ｍＡを超えると出力は低下した。また、従来品Ｂについても９０ｍＡを超えると出力低下がみられた。発光波長についても、略ＬＥＤチップの温度と推測される波長変動をした。
【００２９】一方、本比較例で作成したＬＥＤ照明具は１６０ｍＡまで略比例的に光度が得られ、発光波長変動についても従来品の１／３〜１／２の変動であった。
【００３０】
【発明の効果】以上説明した通り、本発明のＬＥＤランプおよびＬＥＤ照明具は熱による特性変動を非常に低く抑えることが可能となる。従って、光度・色度・変換効率等の特性の安定化、超寿命化の優れた効果を奏でる。
【図面の簡単な説明】
【図１】本発明にかかるＬＥＤランプの斜視図である。
【図２】本発明にかかるＬＥＤランプの断面図である。
【図３】本発明にかかるＬＥＤランプの一例を示す断面図である。
【図４】本発明のＬＥＤランプの放熱機構の説明図である。
【図５】従来のＬＥＤランプを搭載したユニットの断面図である。
【図６】従来の金属ベース基板を使ったＬＥＤユニットの断面図である。
【図７】本発明のＬＥＤランプを搭載したＬＥＤ照明具の断面図である。
【図８】本発明のＬＥＤランプを搭載したＬＥＤ照明具の断面図である。
【図９】比較例品の光出力を示すグラフ図である。
【図１０】比較例品の波長変動を示すグラフ図である。
【符号の説明】
１０１透明樹脂
１０２給電用フレーム
１０３放熱プレート
１０４凹部
１０６ＬＥＤチップ
５１１ＬＥＤディスクリートランプ
５１２放熱樹脂
６１５金属基板
６１６エポキシ絶縁層
７０９ヒートシンク
７１２防湿樹脂
７１３エポキシ回路基板
７１８放熱コンパウンド[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a highly reliable LED lighting device in which a decrease in luminous efficiency due to heat and a change in luminous wavelength are suppressed.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an LED discrete lamp (511) has been mounted as a light source for outdoor lighting lamps, warning lamps, display devices, and the like. However, when a plurality of LED lamps are mounted on the circuit board (513) as an assembly, the heat generated from each of the lamps raises the temperature of the entire lamp, resulting in a decrease in luminous efficiency and a decrease in reliability. As a countermeasure, it is expected that external air is taken into the housing, or that the space between the LED discrete lamp unit and the heat sink is filled with a resin containing filler (512) to diffuse heat (for example, see Patent Document 1).
[0003]
However, the LED chip mounting portion, which is a heat generation source, and the heat dissipation resin (512) are connected only by the lead frame (511a) having a cross section of 0.25 mm ² , and the heat dissipation effect is extremely poor. Therefore, the current value that can be injected into one LED element is about 20 mA, and the higher the density of the LED lamp, the lower the current that can be used.
[0004]
In addition, the LED discrete lamp (511) is connected to the circuit board by two leads, and may be tilted forward or backward or left or right. When used as an assembly, adjustment of individual optical axes in a lighting state is performed. (See FIG. 5).
[0005]
On the other hand, drawing processing is performed on the laminated substrate of the copper foil layer (617), the insulating layer (616), and the metal base (615), the LED chip is mounted on the drawn part, and the LED chip mounting side is passed through the through hole of the metal base. A method of manufacturing an LED unit holding a lens has been proposed (for example, see Patent Document 2).
[0006]
However, since the laminated metal substrate on which the LED elements are mounted is integrally molded with resin, there is no deviation of the optical axis as a unit. High mold cost is required. Further, the LED element, which is a heat source, is mounted on a circuit portion via a metal substrate and an insulating layer, and the thermal resistance from the LED element to the metal substrate is large. In addition, there is a problem that heat can be removed only from the metal base portion at a portion distant from the LED element. (See FIG. 6).
[0007]
[Patent Document 1] JP-A-09-204595 (page 5, FIG. 1)
[Patent Document 2] Japanese Patent Application Laid-Open No. 06-334224 (page 4, FIG. 1)
[0008]
[Problems to be Solved by the Invention] When the heat generated by the LED element is not sufficiently removed as described above, as shown in the conventional products A and B in the graph of FIG. Cannot be obtained, and a large current value wastes power consumption and shortens the life of the light emitting element. Further, as shown in the conventional products A and B in FIG. 10, the emission wavelength shifts to the longer wavelength side and the color tone changes as the junction temperature of the LED element increases.
[0009]
Further, in an LED lamp that emits fluorescent material indirectly using an ultraviolet light emitting device as an excitation light source, there is a problem that the luminous efficiency of the fluorescent material is greatly affected by the wavelength fluctuation of the light emitting device, and the expected luminous intensity and chromaticity cannot be obtained. is there.
[0010]
The LED element is mounted on a material having high thermal conductivity, and the heat generated at the junction of the LED element is conducted to the radiation fin or the like from the rear surface, which is the shortest distance, to reduce the temperature rise of the LED element. By suppressing the fluctuation, the fluctuation of the characteristics due to the change in the current value is minimized, and the reduction of the luminous efficiency and the shortening of the life especially at a large current are prevented.
[0011]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a perspective view showing an example of a frame used for the LED lamp according to the present invention. A heat conductive material having a concave portion having a reflective surface 404b with a flat bottom 404a inclined on the front surface side and a convex portion having a smaller diameter than the main body 403 formed on the rear surface side, and a wire-bondable frame 402 for power supply adhesive. To integrate.
[0012]
Incidentally, when the recessed portion in FIG. 4 is described in detail, assuming that the width of the LED chip to be used is W1, the diameter W of the bottom of the recess is preferably W1 × 1.41 + 0.02 mm ≦ W ≦ W1 × 1.41 + 1.0 mm. And more preferably, W1 × 1.41 + 0.1 mm ≦ W ≦ W1 × 1.41 + 0.5 mm.
[0013]
As for the depth of the depression, assuming that the height of the LED chip to be used is T, the depth H is desirably T ≦ H <T × 5, and more desirably, T × 2 ≦ H ≦ T × 3.
[0014]
Also, the spread angle θ of the reflection surface is desirably 30 ° or more with respect to the bottom surface, and more desirably 45 ° ≦ θ ≦ 75 °. Outside this range, the efficiency of taking out light to the lens surface is reduced.
[0015]
Next, FIG. 1 of the present invention will be described. The LED chip 106 is mounted and fixed on the flat portion 104a at the bottom of the concave portion of the heat radiation plate 103 with an adhesive resin, and the electrode pattern of the LED chip 106 and the power supply frame are wire-bonded. The heat dissipation frame on which the LED chip is mounted is set in a mold so that the LED chip mounting surface is on the lens side. In addition, it is effective to prevent the intrusion of air bubbles by filling in advance the silicon-based flexible resin or the same resin as the molding material in advance in the recessed portion where the LED chip is mounted.
[0016]
Subsequently, a transparent resin is filled so that the projection 103a of the heat radiation plate is exposed. The resin to be filled may be either a thermosetting resin or a thermoplastic resin. In addition, the resin and the convex step are adjusted in consideration of the heat radiation plate to be used and the thermal expansion coefficient of the resin to be used, and the resin filling amount is adjusted so that the convex portion of the heat radiation plate is always horizontal or protrudes when the LED is turned on. .
[0017]
FIG. 7 is an example using the LED lamp of the present invention, and will be described in detail. The LED lamp of the present invention is arranged in the hole of the perforated epoxy circuit board 713, and the circuit of the board and the power supply frame 712 of the LED lamp are connected and fixed with a conductive material such as solder. Next, a heat conductive resin is applied to the projecting portion of the heat dissipation plate on the back side of the LED lamp, and the applied surface is brought into contact with a flat surface of a heat sink such as a heat sink. The board on which the LED lamp is mounted and the radiator are fixed with screws or rivets so that the thickness of the heat conductive resin is reduced.
[0018]
EXAMPLE 1 A copper (reduced copper) disk having a thickness of 2 mm and a diameter of 5.8 mm was placed on the front side with a bottom surface 104a having a diameter of 0.8 mm, a reflecting surface 104b having an angle of 60 ° and a depth of 0.5 mm. The non-conductive adhesive Muromac Bond H-333C is thinly applied to the donut-shaped flat surface of the heat sink plate which has been pressed so as to form the projections 103a having a diameter of 5.0 mm and a step of 0.6 mm on the dent and the back side. Then, a power supply frame 102 having a 0.3 μm nickel plating on the base and a 3 μm silver plating on the surface was cured for 30 minutes in a 150 ° C. atmosphere under a load of 1.0 kg / cm ² .
[0019]
In the present embodiment was used the adhesive strength 240 Kg / cm ^2, the adhesive strength after curing 150 Kg / cm ² or more. The application of the non-conductive adhesive is performed by a stamping method, but may be performed by a screen printing method or a dispensing method. The load at the time of curing is desirably 2.0 to 0.5 kg / cm ^{2, and} when the load is increased, the case where electrical insulation is not obtained easily occurs. Further, when no load is applied, the thickness of the adhesive becomes non-uniform, and the adhesive strength after curing varies, which causes a decrease in reliability.
[0020]
The LED chip 106 (chip size 0.32 mm square, chip height 0.22 mm, material GaN / sapphire) is arranged and fixed to the concave bottom surface 104a of the heat radiating plate with a non-conductive adhesive Muromac bond H386, and the LED chip surface is fixed. And the power supply frame 102 were connected by a gold wire 105 having a diameter of 25 μm. The non-conductive resin used for fixing the LED chip is more preferably a transparent or white resin, and the colored resin reduces light extraction efficiency to the lens surface due to light absorption. Further, depending on the color of the resin, there is a problem that the chromaticity differs from the original emission color of the LED chip.
[0021]
Subsequently, the recess 104 on which the LED chip is mounted is pre-filled with a transparent epoxy resin, and is mounted on a mold such that the chip mounting surface is on the lower side (the lens surface is also on the mold). A transparent epoxy resin was injected from the gap between the mold and the heat radiating plate so as to be flat with the convex portion 103a of the heat radiating plate. After curing at 120 ° C., the resin was removed from the metal mold to produce an LED lamp 130 having a diameter of φ7 mm and a height of 5.1 mm.
[0022]
In the case where visible light is obtained using an ultraviolet light emitting LED chip as a light source, a silicone resin mixed with a fluorescent agent may be injected into the recessed portion 104, and may be mounted on a mold after curing. If other molding methods such as insert molding are used, a transparent polycarbonate resin, an acrylic resin, or the like can be used.
[0023]
Embodiment 2 A heat radiating plate 303 having the same dimensions as that of Embodiment 1 was formed by melting aluminum, and integrated with a power supply frame in the same manner as in Embodiment 1. An AlN (size 0.5 mm square, thickness 0.1 mm) 308 on which Au capable of wire bonding is vapor-deposited on the surface of the heat dissipation plate is fixed with a thermally conductive resin, and an LED chip 306 a (chip size) is placed thereon. A 0.32 mm square, a chip height of 0.25 mm, a material of AlGaAs / AlGaAs, a front n-electrode, and a back p-electrode) were bonded with a conductive adhesive Muromac Bond A-71S. Subsequently, the surface n-electrode and the feeding frame 302 were connected by a φ25 μm gold wire 305a, and the other feeding frame 302 was connected to the AlN (308) by a φ25 μm gold wire 305b. In the present embodiment, AlN of 200 W / m · K was used, but no particular problem occurred if the material had a thermal conductivity of 150 W / m · K or more.
[0024]
Fill the recessed part of the heat sink with the above LED chip with transparent silicon resin, and after thermosetting, set in a mold designed to prevent the resin from wrapping around the flat surface of the convex part of the heat sink, and mold the transparent polycarbonate resin. The LED lamp 130 was formed by insert molding under the conditions of a temperature of 160 ° C. and a resin temperature of 280 ° C.
[0025]
Embodiment 3 The LED lamp 730 of the present invention prepared in Embodiment 1 was fitted into the hole of the epoxy circuit board 713 having a hole of φ7 mm, and the circuit on the board and the power supply frame of the LED lamp were connected by soldering. . Next, a heat conductive material 718 (oil compound G751 manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the flat portion 103a of the heat radiation plate that appeared on the back surface of the substrate on which the present LED lamp was mounted, and was mounted on a heat sink. The substrate on which the LED lamp was mounted and the heat sink were fixed with tapping screws, and then a moisture-proof resin 712 (Toshiba Silicon TSE399) was applied except for the lens portion on the LED lamp mounting surface to prepare an LED lighting device. In this embodiment, an alumina-mixed silicone oil having a thermal conductivity of 4.5 W / m · K was used. However, if the thickness of the thermal conductive material can be fixed to 0.1 mm or less, a thermal conductivity of 2.0 W / m · K is used. However, sufficient characteristics could be secured.
[0026]
Embodiment 4 A heat sink provided with an aluminum material and a fin having a thickness of 20 mm and a thickness of 2 mm was formed from an aluminum material in order to improve the heat radiation efficiency and a head portion having a reflecting surface with a radius of 15 mm and a condensing lens 822 inside. . Next, a cable was connected to the positive pole of the power supply plate 102 of the LED lamp of the present invention created in Example 1, and a heat conductive material 818 (54012 made by AOS, thermal conductivity 2.58 W / M · K), and the LED lamp was set so that the lens side of the LED lamp was on the head side. The other power supply frame (-pole) of the one LED lamp was brought into contact with the heat sink, and the head was screwed into the heat sink to produce an LED lighting device.
In the case of a lighting fixture in which a large number of the LED lighting fixtures of this embodiment are arranged in a conductive metal housing, complicated wiring is not required by connecting the negative pole of the control circuit to the housing.
[0028]
COMPARATIVE EXAMPLE 1 By the method of Example 3, an LED illuminator in which 224 LED lamps of the present invention were arranged concentrically in the same concentric circle as a conventional product by using an electric circuit of 7 in series and 32 in parallel. This comparative example was turned on, and a current value flowing through one LED lamp was compared with a conventional product A equipped with a discrete lamp and a conventional product B using a metal laminated substrate. As shown in FIGS. 9 and 10, the output of the conventional product A increased proportionally to around 30 mA, but the output decreased when it exceeded 50 mA. In addition, the output of the conventional product B was also reduced when the output exceeded 90 mA. The emission wavelength also fluctuated, which is assumed to be approximately the temperature of the LED chip.
On the other hand, the LED luminaire produced in this comparative example can obtain the luminous intensity almost proportionally up to 160 mA, and the fluctuation of the emission wavelength is 1/3 to 1/2 that of the conventional product.
[0030]
As described above, the LED lamp and the LED lighting device of the present invention can suppress characteristic fluctuations due to heat to a very low level. Therefore, excellent effects such as stabilization of characteristics such as luminous intensity, chromaticity, and conversion efficiency, and prolongation of life can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view of an LED lamp according to the present invention.
FIG. 2 is a sectional view of an LED lamp according to the present invention.
FIG. 3 is a sectional view showing an example of the LED lamp according to the present invention.
FIG. 4 is an explanatory view of a heat radiation mechanism of the LED lamp of the present invention.
FIG. 5 is a cross-sectional view of a unit equipped with a conventional LED lamp.
FIG. 6 is a cross-sectional view of an LED unit using a conventional metal base substrate.
FIG. 7 is a cross-sectional view of an LED lighting device equipped with the LED lamp of the present invention.
FIG. 8 is a sectional view of an LED lighting device equipped with the LED lamp of the present invention.
FIG. 9 is a graph showing the light output of a comparative example product.
FIG. 10 is a graph showing a wavelength variation of a comparative example product.
[Explanation of symbols]
101 Transparent Resin 102 Power Supply Frame 103 Heat Dissipation Plate 104 Depression 106 LED Chip 511 LED Discrete Lamp 512 Heat Dissipation Resin 615 Metal Substrate 616 Epoxy Insulating Layer 709 Heat Sink 712 Moisture Proof Resin 713 Epoxy Circuit Board 718 Heat Dissipation Compound

Claims

A conductive metal frame (102) and a heat radiating plate (103) made of a material having a concave portion (104) and a convex portion (103a) having a thermal conductivity of 150 Kcal / m · hr · ° C or higher are connected by a non-conductive resin. At least one LED chip (106) is mounted in the recess (104), and a first resin mold part (101a) having lens characteristics on the LED chip mounting surface side and a part of the heat radiation plate (101). An LED lamp, wherein a second resin mold part (101b) molded so that 103a) is exposed is integrally molded.

An LED lighting device in which a heat conductive metal (709) for heat radiation and one or more LED lamps according to claim 1 are in contact with a heat conductive material (718) to improve a heat radiation effect.