JP2013026244A - Led light source - Google Patents

Led light source Download PDF

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JP2013026244A
JP2013026244A JP2011156190A JP2011156190A JP2013026244A JP 2013026244 A JP2013026244 A JP 2013026244A JP 2011156190 A JP2011156190 A JP 2011156190A JP 2011156190 A JP2011156190 A JP 2011156190A JP 2013026244 A JP2013026244 A JP 2013026244A
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phosphor layer
led chip
led
light source
light
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Tomonori Ito
知規 伊藤
Hirotoshi Oikaze
寛歳 追風
Kentaro Nishiwaki
健太郎 西脇
Isayuki Nagahama
功幸 長浜
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Panasonic Corp
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Panasonic Corp
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    • HELECTRICITY
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    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/02Bonding areas; Manufacturing methods related thereto
    • H01L2224/04Structure, shape, material or disposition of the bonding areas prior to the connecting process
    • H01L2224/05Structure, shape, material or disposition of the bonding areas prior to the connecting process of an individual bonding area
    • H01L2224/0554External layer
    • H01L2224/0555Shape
    • H01L2224/05552Shape in top view
    • H01L2224/05553Shape in top view being rectangular
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    • H01L2224/02Bonding areas; Manufacturing methods related thereto
    • H01L2224/04Structure, shape, material or disposition of the bonding areas prior to the connecting process
    • H01L2224/05Structure, shape, material or disposition of the bonding areas prior to the connecting process of an individual bonding area
    • H01L2224/0554External layer
    • H01L2224/0555Shape
    • H01L2224/05552Shape in top view
    • H01L2224/05554Shape in top view being square
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    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/31Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L2224/32Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H01L2224/321Disposition
    • H01L2224/32151Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/32221Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/32225Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/47Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805Shape
    • H01L2224/4809Loop shape
    • H01L2224/48091Arched
    • HELECTRICITY
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    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/47Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/481Disposition
    • H01L2224/48151Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/48221Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/48225Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H01L2224/48227Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation connecting the wire to a bond pad of the item
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
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    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/47Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/49Structure, shape, material or disposition of the wire connectors after the connecting process of a plurality of wire connectors
    • H01L2224/491Disposition
    • H01L2224/4912Layout
    • H01L2224/49175Parallel arrangements
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    • H01L2224/73Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
    • H01L2224/732Location after the connecting process
    • H01L2224/73251Location after the connecting process on different surfaces
    • H01L2224/73265Layer and wire connectors

Abstract

PROBLEM TO BE SOLVED: To provide an LED light source with improved light emitting efficiency.SOLUTION: An LED chip 11 includes the LED chip 11 mounted on a wiring board 12 and a phosphor layer FL for covering the LED chip 11. The phosphor layer FL contains a phosphor particles FP, which convert a wavelength of a ray of light emitted from the LED chip 11 into a longer wavelength, and a transmissive resin TR. A cross-section outline Sfl, Lfl of the phosphor layer FL is formed with a curve Lfl which is concave in a direction toward a center O of the LED chip 11.

Description

本発明は、LED光源に関する。   The present invention relates to an LED light source.

近年、励起光源として、青色LED、紫LED、UV(紫外線)LED等の半導体発光素子からの発光された光の一部またはすべてを、蛍光体により変換して白色光を発生させる小型の白色LEDに注目が集まっている。   Recently, as an excitation light source, a small white LED that generates white light by converting a part or all of light emitted from a semiconductor light emitting element such as a blue LED, a purple LED, and a UV (ultraviolet) LED with a phosphor. Attention has been gathered.

半導体発光素子(励起光源)と蛍光体(変換物質)とを組み合わせた発光装置は、照明光源や液晶バックライト光源などの分野で利用されている。このような発光装置は、例えばシリコン樹脂やガラス等の透光性部材の材料中に蛍光体を含有させた後、発光素子が搭載された凹部内に、樹脂をディスペンサなどで滴下注入し、当該樹脂を熱硬化させることにより形成される(例えば、特許文献1参照)。   A light emitting device in which a semiconductor light emitting element (excitation light source) and a phosphor (converting substance) are combined is used in fields such as an illumination light source and a liquid crystal backlight light source. In such a light-emitting device, for example, a phosphor is contained in a material of a translucent member such as silicon resin or glass, and then the resin is dropped and injected into a concave portion in which the light-emitting element is mounted with a dispenser or the like. It is formed by thermally curing a resin (see, for example, Patent Document 1).

また、GaN(窒化ガリウム)等の化合物で構成される半導体基板を用いたLEDチップにおいては、LEDチップの上面には蛍光物質が塗布されると共に、電極から導電性ワイヤーにより外部に引き出される構造となっている。(例えば、特許文献2参照)。   In addition, in an LED chip using a semiconductor substrate composed of a compound such as GaN (gallium nitride), a fluorescent material is applied to the upper surface of the LED chip, and the structure is drawn out from the electrode by a conductive wire. It has become. (For example, refer to Patent Document 2).

LEDはGaP(ガリウムリン)やGaN等の化合物半導体ウエハ上にPN接合を形成し、これに順方向電流を通じて可視光又は近赤外光の発光を得るものであり、近年、表示、通信、計測、及び制御等の分野に広く応用されている。しかし、このようなLEDを用いた光源(以下、「LED光源」と称する)の発光色は限られた色調のものしか存在しない。そこで、所望の発光色を得ようと、透過性樹脂であるエポキシ樹脂やシリコン樹脂等の封止樹脂中に蛍光物質や着色剤を含有させる試みがある。このような従来のLEDの一例を、図面を参照して以下に説明する。   An LED forms a PN junction on a compound semiconductor wafer such as GaP (gallium phosphide) or GaN, and emits visible light or near-infrared light through a forward current thereto. In recent years, display, communication, and measurement are performed. And widely applied in the fields of control and the like. However, the light emission color of such a light source using LEDs (hereinafter referred to as “LED light source”) has only a limited color tone. Therefore, in order to obtain a desired emission color, there is an attempt to include a fluorescent material or a colorant in a sealing resin such as an epoxy resin or a silicon resin that is a transparent resin. An example of such a conventional LED will be described below with reference to the drawings.

図8に、従来のLED光源1の縦断面を示す。LEDチップ11は、GaN(窒化ガリウム)系の青色LEDチップである。配線基板12の両面銅箔部にはメッキレジストがラミネートされ、露光現像により配線パターンが形成され、更にその上に金メッキ等の表面処理が施されている。基板電極121は、上面電極121aから側面電極121bを経由して下面電極121cに至る配線パターンである。基板電極122は、上面電極122aから側面電極122bを経由して下面電極122cに至る他方の電極パターンである。   In FIG. 8, the longitudinal cross-section of the conventional LED light source 1 is shown. The LED chip 11 is a GaN (gallium nitride) blue LED chip. A plating resist is laminated on the double-sided copper foil portion of the wiring board 12, a wiring pattern is formed by exposure and development, and surface treatment such as gold plating is further performed thereon. The substrate electrode 121 is a wiring pattern extending from the upper surface electrode 121a to the lower surface electrode 121c via the side surface electrode 121b. The substrate electrode 122 is the other electrode pattern from the upper surface electrode 122a to the lower surface electrode 122c via the side surface electrode 122b.

接着材13を介して、上面電極121aにLEDチップ11がダイボンディングされた配線基板12は両面銅箔張りのガラスエポキシ樹脂等より成る。ボンディングワイヤ14はAu(金)線等より成る。LEDチップ電極112は、LEDチップ11の上面に設けられている。LEDチップ電極112と基板電極121とはボンディングワイヤ14によって接続されている。LEDチップ11、LEDチップ電極112の接続部、及びボンディングワイヤ14等の保護と、LEDチップ11からの効果的な発光とを実現するために、これらの表面は蛍光体層15によって封止されている。なお、蛍光体層15は、透光性のエポキシ樹脂等から成る透光性樹脂151を有する。   The wiring board 12 in which the LED chip 11 is die-bonded to the upper surface electrode 121a through the adhesive 13 is made of a glass epoxy resin or the like covered with a double-sided copper foil. The bonding wire 14 is made of Au (gold) wire or the like. The LED chip electrode 112 is provided on the upper surface of the LED chip 11. The LED chip electrode 112 and the substrate electrode 121 are connected by a bonding wire 14. In order to realize protection of the LED chip 11, the connection part of the LED chip electrode 112, the bonding wire 14, and the like and effective light emission from the LED chip 11, these surfaces are sealed with the phosphor layer 15. Yes. Note that the phosphor layer 15 includes a translucent resin 151 made of a translucent epoxy resin or the like.

蛍光体層15は、蛍光体粒子152を含有している。LEDチップ11を発光させると、LEDチップ11から発する青色光の一部は、透光性樹脂151の中で蛍光体粒子152に当り、蛍光体粒子152によって黄色光に変化させられて蛍光体層15から出射する。蛍光体粒子152に当たらなかった、青色光は青色のまま、蛍光体層15から出射するので、蛍光体層15から出射した黄色光と青色光とが混じって白色光になる。より詳しく述べれば、蛍光体層15から別々に出射した青色光と黄色光とを、観測する側(人間)が白色光と認識する。このように蛍光体層15から出射された白色光をフィルターして、パステル調の発光色を得ることができる。   The phosphor layer 15 contains phosphor particles 152. When the LED chip 11 is caused to emit light, a part of blue light emitted from the LED chip 11 hits the phosphor particles 152 in the translucent resin 151 and is changed to yellow light by the phosphor particles 152, so that the phosphor layer 15 is emitted. Since the blue light that did not hit the phosphor particles 152 is emitted from the phosphor layer 15 while remaining blue, the yellow light emitted from the phosphor layer 15 and the blue light are mixed to become white light. More specifically, the observing side (human) recognizes blue light and yellow light separately emitted from the phosphor layer 15 as white light. In this way, the white light emitted from the phosphor layer 15 can be filtered to obtain a pastel emission color.

特開平7−99345号公報JP-A-7-99345 特開2003−258310号公報JP 2003-258310 A

しかしながら、上述の構成では、LEDチップの周囲を覆う透光性樹脂151の屈折率n(n=約1.2〜約1.9)が、周囲の空気との屈折率(n=1.0)よりも大きいため、スネルの法則(屈折の法則)より、臨界角が非常に小さく、その結果、一部の光しか外部に放射されないという問題がある。例えば、透光性樹脂151にシリコン(n=1.6)を用いた場合、臨界角は31°である。この場合、角度31°の円錐体内の光だけが蛍光体層15から出射され、光の出力効率は制限を受ける。   However, in the above-described configuration, the refractive index n (n = about 1.2 to about 1.9) of the translucent resin 151 covering the periphery of the LED chip is the refractive index with the surrounding air (n = 1.0). ), The critical angle is much smaller than Snell's law (the law of refraction), and as a result, only a part of the light is emitted to the outside. For example, when silicon (n = 1.6) is used for the translucent resin 151, the critical angle is 31 °. In this case, only the light within the cone having an angle of 31 ° is emitted from the phosphor layer 15, and the light output efficiency is limited.

本発明は、上述の問題に鑑みて、光の取り出し効率が改善されたLED光源を提供することを目的とする。   In view of the above problems, an object of the present invention is to provide an LED light source with improved light extraction efficiency.

上記の課題を解決する為に、本発明は、LED光源であって、
配線基板上に実装されたLEDチップと、
前記LEDチップを覆う蛍光体層とを備え、
前記蛍光体層は、前記LEDチップから出射された光の波長をより長い波長に変換する蛍光体粒子と、透過性樹脂とを含み、
前記蛍光体層の断面輪郭が前記LEDチップの中心方向に凹んだ曲線で形成されていることを特徴とする。
In order to solve the above problems, the present invention is an LED light source,
An LED chip mounted on a wiring board;
A phosphor layer covering the LED chip,
The phosphor layer includes phosphor particles that convert the wavelength of light emitted from the LED chip into a longer wavelength, and a transmissive resin.
The cross-sectional outline of the phosphor layer is formed by a curve that is recessed in the center direction of the LED chip.

本発明のLED光源によれば、LEDチップを覆う蛍光体層からの臨界角出射の確率を増やすことができ、その結果、蛍光体層からの光の取り出し効率を向上させる効果を奏する。   According to the LED light source of the present invention, the probability of the critical angle emission from the phosphor layer covering the LED chip can be increased, and as a result, the effect of improving the light extraction efficiency from the phosphor layer is achieved.

本発明の実施の形態1に係るLED光源の構成を示す縦断面図である。It is a longitudinal cross-sectional view which shows the structure of the LED light source which concerns on Embodiment 1 of this invention. 図1に示すLED光源を上から見た平面図である。It is the top view which looked at the LED light source shown in FIG. 1 from the top. 図1に示すLED光源の蛍光体層の側面輪郭形状の説明図である。It is explanatory drawing of the side surface outline shape of the fluorescent substance layer of the LED light source shown in FIG. 本発明の実施の形態2に係るLED光源を上から見た平面図である。It is the top view which looked at the LED light source which concerns on Embodiment 2 of this invention from the top. 図4に示すLED光源の蛍光体層の底面輪郭形状の説明図である。It is explanatory drawing of the bottom face contour shape of the fluorescent substance layer of the LED light source shown in FIG. 本発明の実施の形態3に係るLED光源を上から見た平面図である。It is the top view which looked at the LED light source which concerns on Embodiment 3 of this invention from the top. 図6に示すLED光源の蛍光体層の輪郭形状の説明図である。It is explanatory drawing of the outline shape of the fluorescent substance layer of the LED light source shown in FIG. 従来のLED光源の構成を示す縦断面図である。It is a longitudinal cross-sectional view which shows the structure of the conventional LED light source.

(実施の形態1)
以下に、図1、図2、及び図3を参照して本発明の実施の形態1について、図面を参照しながら説明する。図1に実施の形態1に係るLED光源LS1の縦断面構造を示し、図2にLED光源LS1を上から見た状態を示す。LEDチップ11は、例えば波長380nmから780nmの可視領域の範囲内にピーク波長を有する光を出射するLEDを用いることができる。LEDチップ11は、図1に示すように、接着剤13を介して配線基板12の上に設けられた基板電極121に実装されている。LEDチップ11の占有面積は、接着剤13の面積よりも小さく、LEDチップ11の周囲には接着剤13がはみ出ている。
(Embodiment 1)
The first embodiment of the present invention will be described below with reference to the drawings with reference to FIG. 1, FIG. 2, and FIG. FIG. 1 shows a longitudinal sectional structure of an LED light source LS1 according to Embodiment 1, and FIG. 2 shows a state of the LED light source LS1 as viewed from above. As the LED chip 11, for example, an LED that emits light having a peak wavelength within a visible range of wavelengths from 380 nm to 780 nm can be used. As shown in FIG. 1, the LED chip 11 is mounted on a substrate electrode 121 provided on the wiring substrate 12 via an adhesive 13. The area occupied by the LED chip 11 is smaller than the area of the adhesive 13, and the adhesive 13 protrudes around the LED chip 11.

LEDチップ11の上面には、LEDチップ電極112が2つ設けられている。LEDチップ電極112は、ボンディングワイヤ14などにより、配線基板12上の基板電極121(図2)と電気的に接続されている。これにより、LEDチップ11に電流を供給して、LEDチップ発光部111に発光を引き起すことができる。基板電極121を備える配線基板12は多層配線基板であっても良い。複数個のLEDチップ11が単一の配線基板12に実装される場合、配線基板12は放熱性に優れたメタルコンポジット基板を用いて作成されることが望ましい。   Two LED chip electrodes 112 are provided on the upper surface of the LED chip 11. The LED chip electrode 112 is electrically connected to the substrate electrode 121 (FIG. 2) on the wiring substrate 12 by a bonding wire 14 or the like. Thereby, current can be supplied to the LED chip 11 to cause the LED chip light emitting unit 111 to emit light. The wiring substrate 12 including the substrate electrode 121 may be a multilayer wiring substrate. When a plurality of LED chips 11 are mounted on a single wiring board 12, it is desirable that the wiring board 12 be formed using a metal composite board having excellent heat dissipation.

LEDチップ11は、透光性樹脂TR1の中に無数の蛍光体粒子FPが分散する蛍光体層FL1で被覆されている。透光性樹脂TR1は、直径Dの円形底面(図2)から、高さH(図1)まで凹状斜面により、概ね円錐形状に形成されている。なお、透光性樹脂TR1の高さHは、蛍光体層FL1の高さでもある。本実施の形態においては透光性樹脂TR1の底面形状は直径Dで規定される円形としているが、これに限定されるものではなく、これについては後ほど図4、図5、図6、及び図7を参照して説明する。なお、本実施の形態において、円形底面の直径Dを透光性樹脂TR1の幅W1と呼ぶ。透光性樹脂TR1は、電気的絶縁性を有し、LEDチップ11から発せられる光が透過する性質を有する材料から構成される。透光性樹脂TR1の材料として、例えば、シリコン樹脂、アクリル樹脂、エポキシ樹脂、及びフッ素樹脂等の樹脂類やガラス等の材料を用いることができる。シリコン樹脂を用いた場合、透光性樹脂TR1の屈折率n1は、約1.4である。   The LED chip 11 is covered with a phosphor layer FL1 in which countless phosphor particles FP are dispersed in a translucent resin TR1. The translucent resin TR1 is formed in a substantially conical shape by a concave slope from a circular bottom surface (FIG. 2) having a diameter D to a height H (FIG. 1). The height H of the translucent resin TR1 is also the height of the phosphor layer FL1. In the present embodiment, the shape of the bottom surface of the translucent resin TR1 is a circle defined by the diameter D, but is not limited to this, and this will be described later with reference to FIG. 4, FIG. 5, FIG. This will be described with reference to FIG. In the present embodiment, the diameter D of the circular bottom is referred to as the width W1 of the translucent resin TR1. The translucent resin TR1 is made of a material having electrical insulation and a property of transmitting light emitted from the LED chip 11. As a material of the translucent resin TR1, for example, a resin such as a silicon resin, an acrylic resin, an epoxy resin, and a fluororesin, or a material such as glass can be used. When silicon resin is used, the refractive index n1 of the translucent resin TR1 is about 1.4.

蛍光体粒子FPは、LEDチップ11から放射される青色光を黄色光に変換する。蛍光体粒子FPとしては、YAG(イットリウム・アルゴン・ガーネット)等の材料が用いられる。最終商品(LED光源)の種類に応じて、蛍光体層FL1に分散させる蛍光体粒子FPの種類(蛍光体粒子のサイズや材質)を適宜変更調整する必要がある。蛍光体粒子FPの種類(サイズや材質)は1つに限定されず、1つの蛍光体層FL1(透光性樹脂TR1)に複数種類の蛍光体粒子FPを混在させても良い。通常、蛍光体粒子FPは、その粒度分布が10μmから20μmであるものが用いられるが、本発明ではその限りでなく、50μm以下の粒度分布のもので良い。   The phosphor particles FP convert blue light emitted from the LED chip 11 into yellow light. As the phosphor particles FP, materials such as YAG (yttrium, argon, garnet) are used. In accordance with the type of the final product (LED light source), it is necessary to appropriately change and adjust the type (phosphor particle size and material) of the phosphor particles FP dispersed in the phosphor layer FL1. The kind (size or material) of the phosphor particles FP is not limited to one, and a plurality of kinds of phosphor particles FP may be mixed in one phosphor layer FL1 (translucent resin TR1). In general, the phosphor particles FP having a particle size distribution of 10 μm to 20 μm are used, but the present invention is not limited thereto, and may be those having a particle size distribution of 50 μm or less.

次に、図3を参照して、蛍光体層FL1(特に凹状斜面)の形状について説明する。同図において、LEDチップ11の縦断面の中心をOとし、Oを通りLEDチップ11の発光面に対して垂直な(LEDチップ11厚み)方向に伸びる軸をZ軸とし、Oを通りZ軸に垂直な(LEDチップ11の発光面に平行な長さ)方向に伸びる軸をX軸としている。図3においては、図1に示した蛍光体層FL1の約右半分が示されている。なお、図3は、図1同様に、LEDチップ11の一片における断面図である。   Next, the shape of the phosphor layer FL1 (particularly the concave slope) will be described with reference to FIG. In the figure, the center of the vertical cross section of the LED chip 11 is O, the axis extending through the O in the direction perpendicular to the light emitting surface of the LED chip 11 (the thickness of the LED chip 11) is the Z axis, and passing through O is the Z axis. An axis extending in a direction perpendicular to the LED (length parallel to the light emitting surface of the LED chip 11) is taken as an X axis. In FIG. 3, the right half of the phosphor layer FL1 shown in FIG. 1 is shown. 3 is a cross-sectional view of one piece of the LED chip 11 as in FIG.

曲線Lfl1は、X軸(Y軸)とZ軸で規定されるXZ(YZ)平面で蛍光体層FL1を切った時の蛍光体層FL1の最外縁部の形状、つまり蛍光体層FL1の側面輪郭を示している。この意味において、曲線Lfl1を蛍光体層輪郭或いは蛍光体層外縁と呼ぶ。蛍光体層輪郭Lfl1は、蛍光体層FL1と周囲(空気)との境界線でもある。つまり、蛍光体層輪郭Lfl1は蛍光体層FL1と周囲との境界線でもあり、この境界線(蛍光体層輪郭Lfl1)で規定される蛍光体層FL1の表面を蛍光体層境界面Sfl1と呼ぶ。なお、紙面の都合状、円錐状の頂点および底面の外縁部は示されていない。   A curved line Lfl1 is the shape of the outermost edge of the phosphor layer FL1 when the phosphor layer FL1 is cut along the XZ (YZ) plane defined by the X axis (Y axis) and the Z axis, that is, the side surface of the phosphor layer FL1. Outline is shown. In this sense, the curve Lfl1 is referred to as a phosphor layer outline or a phosphor layer outer edge. The phosphor layer contour Lfl1 is also a boundary line between the phosphor layer FL1 and the surrounding (air). That is, the phosphor layer contour Lfl1 is also a boundary line between the phosphor layer FL1 and the surroundings, and the surface of the phosphor layer FL1 defined by this boundary line (phosphor layer contour Lfl1) is referred to as a phosphor layer boundary surface Sfl1. . In addition, the convenience of a paper surface, the conical vertex, and the outer edge part of a bottom face are not shown.

蛍光体層FL1の凹状斜面(蛍光体層境界面Sfl1)は、LEDチップ11の上面および側面から発せられる光を効率的に蛍光体層FL1の外側の空気層へ出射するために、LEDチップ11の中心Oに向かって凹んだ輪郭形状を有する。なお、LED光源LS1をXY平面で切った時の蛍光体層FL1の輪郭は、蛍光体層FL1の高さH(以降、「蛍光体層高H」と称する)がゼロ、つまり底部では直径Dの円形であり、蛍光体層高Hに応じてDより小さな直径で規定される円形である。上述のように、底部での直径Dを蛍光体層FL1の幅W1と呼ぶ。   The concave slope (phosphor layer boundary surface Sfl1) of the phosphor layer FL1 is used to efficiently emit light emitted from the upper surface and side surfaces of the LED chip 11 to the air layer outside the phosphor layer FL1. And has a contour shape recessed toward the center O. The outline of the phosphor layer FL1 when the LED light source LS1 is cut along the XY plane is that the height H of the phosphor layer FL1 (hereinafter referred to as “phosphor layer height H”) is zero, that is, the diameter D at the bottom. A circle defined by a diameter smaller than D according to the phosphor layer height H. As described above, the diameter D at the bottom is referred to as the width W1 of the phosphor layer FL1.

蛍光体層高Hは、LEDチップ11の形状にもよるが、例えばLEDチップ11の断面形状の厚みh(以降、「LEDチップ厚h」と称する)の約1.5倍〜10倍(1.5h≦H≦10h)程度が好ましく、より好ましくは1.5倍〜3倍未満(1.5h≦H<3h)である。つまり、1.5h≦H≦10hの場合、LEDチップ11より発せられた青色光と、蛍光体粒子FPで変換された黄色光とが蛍光体層FL1内で反射する回数が少なく、且つ光路長が短いので、蛍光体層FL1中での光減衰によるLED光源LS1としての発光ロスを抑えられる。また、1.5h≦H<3hの場合は、蛍光体層FL1の形成が1.5h≦H≦10hの場合に比べて容易であるので、複数個の蛍光体層FL1(LED光源LS1)を形成する場合にも、一定の形状を得ることができる。結果、複数のLED光源LS1のそれぞれの蛍光体層FL1から出射する光のばらつきを抑えることができる。   The phosphor layer height H depends on the shape of the LED chip 11, but is about 1.5 to 10 times (1) the thickness h (hereinafter referred to as “LED chip thickness h”) of the LED chip 11, for example. 0.5 h ≦ H ≦ 10 h) is preferable, and more preferably 1.5 times to less than 3 times (1.5 h ≦ H <3 h). That is, when 1.5h ≦ H ≦ 10h, the number of times that the blue light emitted from the LED chip 11 and the yellow light converted by the phosphor particles FP are reflected in the phosphor layer FL1 is small, and the optical path length is Therefore, a light emission loss as the LED light source LS1 due to light attenuation in the phosphor layer FL1 can be suppressed. Further, in the case of 1.5h ≦ H <3h, the formation of the phosphor layer FL1 is easier than in the case of 1.5h ≦ H ≦ 10h, and therefore a plurality of phosphor layers FL1 (LED light sources LS1) are formed. Even when it is formed, a certain shape can be obtained. As a result, it is possible to suppress variations in light emitted from the respective phosphor layers FL1 of the plurality of LED light sources LS1.

蛍光体層高HがLEDチップ厚hの1.5倍未満(H<1.5h)の場合、LEDチップ11と蛍光体層境界面Sfl1(蛍光体層輪郭Lfl1)との距離L1が極めて近いため、蛍光体層境界面Sfl1の表面精度(形状や面粗度)の影響で、LEDチップ11或いは蛍光体粒子FPから発せられた光が蛍光体層境界面Sfl1で乱反射される成分(以降、「乱反射成分」)が多くなり、LED光源LS1としての発光ロスが増加する。また、蛍光体層FL1の幅W1(W1=D)は、LEDチップ11の縦断面形状の長さaの1.5倍〜10倍(1.5a≦W1≦10a)程度に設計することが好ましく、3倍未満(W1<3a)であることがより好ましい。なお、図1に示すように、本実施の形態においては、LEDチップ11は四角柱状に形成されており、その寸法はa×a×hで表すことができる。1辺がaでなく、bの場合は、aとbの長い方を、縦断面図の長さaとする。   When the phosphor layer height H is less than 1.5 times the LED chip thickness h (H <1.5h), the distance L1 between the LED chip 11 and the phosphor layer boundary surface Sfl1 (phosphor layer contour Lfl1) is extremely short. Therefore, a component (hereinafter referred to as a component) in which light emitted from the LED chip 11 or the phosphor particle FP is diffusely reflected by the phosphor layer boundary surface Sfl1 due to the influence of the surface accuracy (shape and surface roughness) of the phosphor layer boundary surface Sfl1. The “irregular reflection component”) increases, and the light emission loss as the LED light source LS1 increases. Further, the width W1 (W1 = D) of the phosphor layer FL1 is designed to be about 1.5 to 10 times (1.5a ≦ W1 ≦ 10a) of the length a of the vertical cross-sectional shape of the LED chip 11. Preferably, it is less than 3 times (W1 <3a). As shown in FIG. 1, in the present embodiment, the LED chip 11 is formed in a quadrangular prism shape, and the dimension can be expressed as a × a × h. When one side is not a but b, the longer one of a and b is the length a in the longitudinal sectional view.

蛍光体層FL1の幅W1がLEDチップ11の断面形状の長さaの3倍以上(W1≧3a)であると、蛍光体層FL1の形状のアスペクト比(蛍光体層FL1の高さHと断面形状の長さaの比)が大きくなる。LEDチップ11の断面形状の長さaに対して蛍光体層FL1の高さが大きくなると、蛍光体層FL1が曲がり易く折れ易いので、蛍光体層FL1の形状の形成および形状の保持が困難になり、蛍光体層FL1の形状不良が発生し易くなる。蛍光体層FL1の幅W1がLEDチップ11の断面形状の長さaの10倍より大きく(W1>10a)なると、LEDチップ11より発せられた青色光および、蛍光体粒子FPで変換された黄色光が蛍光体層FL1内で反射する回数が増加し、光路長も長くなるため、蛍光体層FL1内での光の減衰によるLED光源LS1としての発光ロスが幅W1に応じて急激に増加する。   When the width W1 of the phosphor layer FL1 is at least three times the length a of the cross-sectional shape of the LED chip 11 (W1 ≧ 3a), the aspect ratio of the shape of the phosphor layer FL1 (the height H of the phosphor layer FL1) The ratio of the cross-sectional length a) becomes larger. When the height of the phosphor layer FL1 increases with respect to the length a of the cross-sectional shape of the LED chip 11, the phosphor layer FL1 is easily bent and easily broken, so that it is difficult to form and maintain the shape of the phosphor layer FL1. Accordingly, the shape defect of the phosphor layer FL1 is likely to occur. When the width W1 of the phosphor layer FL1 is larger than 10 times the length a of the cross-sectional shape of the LED chip 11 (W1> 10a), blue light emitted from the LED chip 11 and yellow converted by the phosphor particles FP Since the number of times the light is reflected in the phosphor layer FL1 increases and the optical path length increases, the light emission loss as the LED light source LS1 due to the attenuation of the light in the phosphor layer FL1 increases rapidly according to the width W1. .

蛍光体層FL1の幅W1がLEDチップ11の長さaの1.5倍未満(W1<1.5a)の場合、蛍光体層FL1の形状はLEDチップ11と蛍光体層FL1の蛍光体層輪郭Lfl1との距離L1が極めて近くなる。そのため、蛍光体層境界面Sfl1の表面精度の影響で、蛍光体層境界面Sfl1での反射時の乱反射成分が多くなり、LED光源LS1としての発光ロスが増加する。図3に示した例では、LEDチップ11の寸法が約0.3mm×0.3mm×厚み0.1mm(LEDチップ厚h=0.1mmで、a=0.3mmで、奥行き(不図示)=0.3mm)のときに、蛍光体層高Hは0.15mm〜約1.0mm(例えば、H=0.3mm)であり、蛍光体層FL1の幅W1は約0.25mm〜1.5mm(例えば、W1=0.5mm)である。   When the width W1 of the phosphor layer FL1 is less than 1.5 times the length a of the LED chip 11 (W1 <1.5a), the shape of the phosphor layer FL1 is the phosphor layer of the LED chip 11 and the phosphor layer FL1. The distance L1 with the contour Lfl1 is very close. Therefore, due to the influence of the surface accuracy of the phosphor layer boundary surface Sfl1, the irregular reflection component at the time of reflection on the phosphor layer boundary surface Sfl1 increases, and the light emission loss as the LED light source LS1 increases. In the example shown in FIG. 3, the dimensions of the LED chip 11 are about 0.3 mm × 0.3 mm × thickness 0.1 mm (LED chip thickness h = 0.1 mm, a = 0.3 mm, depth (not shown). = 0.3 mm), the phosphor layer height H is 0.15 mm to about 1.0 mm (for example, H = 0.3 mm), and the width W1 of the phosphor layer FL1 is about 0.25 mm to 1.mm. 5 mm (for example, W1 = 0.5 mm).

さらに、蛍光体層境界面Sfl1は、蛍光体層輪郭Lfl1がX軸およびZ軸を漸近線とする直角双曲線の一つに相当するとなお良い。この場合の蛍光体層輪郭Lfl1とLEDチップ11との距離L1は、LEDチップ11の形状にもよるが、0からLEDチップ厚hの3倍未満(0<L<3h)が好ましく、2倍未満(0<L<2h)がより好ましいことが確認されている。蛍光体層境界面Sfl1とLEDチップ11との距離L1がLEDチップ厚hの2倍以上(L≧2h)の場合、LEDチップ11より発せられた青色光および、蛍光体粒子FPで変換された黄色光が蛍光体層境界面Sfl1から出射する条件が満足されず、蛍光体層FL1内で反射する回数が増加し、光路長も長くなるため、減衰によるLED光源LS1としての発光ロスが距離L1に応じて急激に増加する。さらに、蛍光体層境界面Sfl1とLEDチップ11との距離L1がLEDチップ厚hの3倍以上の場合、蛍光体層FL1とLEDチップ11との線膨張率の差の影響によりLEDチップ11に応力が集中し、LEDチップ11にダメージが発生し易い。   Further, the phosphor layer boundary surface Sfl1 is more preferably equivalent to one of the right-angled hyperbola in which the phosphor layer contour Lfl1 has asymptotic lines on the X axis and the Z axis. In this case, the distance L1 between the phosphor layer contour Lfl1 and the LED chip 11 is preferably 0 to less than 3 times the LED chip thickness h (0 <L <3h), although it depends on the shape of the LED chip 11. Less than (0 <L <2h) has been confirmed to be more preferable. When the distance L1 between the phosphor layer boundary surface Sfl1 and the LED chip 11 is more than twice the LED chip thickness h (L ≧ 2h), it is converted by the blue light emitted from the LED chip 11 and the phosphor particles FP. The condition for emitting yellow light from the phosphor layer boundary surface Sfl1 is not satisfied, the number of reflections in the phosphor layer FL1 is increased, and the optical path length is also increased. Therefore, the emission loss as the LED light source LS1 due to attenuation is reduced by the distance L1. It increases rapidly according to. Furthermore, when the distance L1 between the phosphor layer boundary surface Sfl1 and the LED chip 11 is three times or more the LED chip thickness h, the LED chip 11 is affected by the difference in linear expansion coefficient between the phosphor layer FL1 and the LED chip 11. Stress concentrates and the LED chip 11 is easily damaged.

図1、図2及び図3を参照して述べたように、本実施の形態においては、LED光源LS1の最小単位は、1つの配線基板12の上に設けられた複数の基板電極121の1つに、1つのLEDチップ11が接着剤13で接合され、LEDチップ発光部111が設けられた2つのLEDチップ電極112がそれぞれボンディングワイヤ14によって残りの基板電極121に接続されたLEDチップ11の全体が、蛍光体層FL1で覆われて構成されている。本発明において、LED光源は、複数のLED光源LS1を2次元アレイ状に配列して構成しても良い。   As described with reference to FIGS. 1, 2, and 3, in the present embodiment, the minimum unit of the LED light source LS <b> 1 is one of the plurality of substrate electrodes 121 provided on one wiring substrate 12. One LED chip 11 is bonded with an adhesive 13, and two LED chip electrodes 112 provided with LED chip light emitting portions 111 are connected to the remaining substrate electrodes 121 by bonding wires 14, respectively. The whole is covered with the phosphor layer FL1. In the present invention, the LED light source may be configured by arranging a plurality of LED light sources LS1 in a two-dimensional array.

具体的には、1つの配線基板12の主面上に、複数のLEDチップ11が2次元アレイ状に配列され、その複数のLEDチップ11のそれぞれに対応して蛍光体層FL1が個々のLEDチップ11を覆うように設けられる。この複数のLEDチップ11は全て同一のサイズであっても良いし、異なるサイズであっても良い。さらに、複数のLEDチップ11はそれぞれピーク波長の異なるものであっても良い。   Specifically, a plurality of LED chips 11 are arranged in a two-dimensional array on the main surface of one wiring substrate 12, and the phosphor layer FL 1 is an individual LED corresponding to each of the plurality of LED chips 11. It is provided so as to cover the chip 11. The plurality of LED chips 11 may all have the same size or different sizes. Further, the plurality of LED chips 11 may have different peak wavelengths.

また、複数のLEDチップ11のそれぞれに設けられる蛍光体層FL1に含まれる透光性樹脂TR1の数或いは材質は、同一であってもLEDチップ11毎に異なっても良い。さらに、複数の透光性樹脂TR1の個々は同一の形状であっても、それぞれ異なる形状であっても良い。   Further, the number or the material of the translucent resin TR1 included in the phosphor layer FL1 provided in each of the plurality of LED chips 11 may be the same or different for each LED chip 11. Further, each of the plurality of translucent resins TR1 may have the same shape or different shapes.

上述のように、本実施形態のLED光源LS1においては、LEDチップ11から発せられる青色から紫外にわたる波長の青色光の一部が、LEDチップ11を覆う蛍光体層FL1内の蛍光体粒子FPにより青色光とは異なる波長の光に変換される。この青色光と青色光が波長変換されて生成された光(以降、「波長変換光」と称する)とが蛍光体層FL1の内部或いは外部で混合されて、実質的にLED光源LS1から白色系の光が発せられる。   As described above, in the LED light source LS1 of the present embodiment, part of blue light having a wavelength ranging from blue to ultraviolet emitted from the LED chip 11 is caused by the phosphor particles FP in the phosphor layer FL1 covering the LED chip 11. It is converted into light having a wavelength different from that of blue light. The blue light and the light generated by wavelength-converting the blue light (hereinafter referred to as “wavelength converted light”) are mixed inside or outside the phosphor layer FL1 to substantially emit white light from the LED light source LS1. The light is emitted.

特に、本実施形態のLED光源LS1によれば、蛍光体層FL1の断面形状が、LEDチップ11の上面、側面から発せられる光の配光角に相当する形状に形成されている。すなわち、LEDチップ11の上面(LEDチップ発光部111)及び側面から発せられる光の強度分布をより反映させた状態でかつ、蛍光体層FL1から空気層への光の出射効率を高めた蛍光体層FL1を配置することができる。これにより、約5%高い光束を出射するLED光源LS1を得られることが確認されている。   In particular, according to the LED light source LS1 of the present embodiment, the cross-sectional shape of the phosphor layer FL1 is formed in a shape corresponding to the light distribution angle of light emitted from the upper surface and the side surface of the LED chip 11. In other words, the phosphor that reflects the intensity distribution of light emitted from the upper surface (LED chip light emitting unit 111) and the side surface of the LED chip 11 and enhances the light emission efficiency from the phosphor layer FL1 to the air layer. Layer FL1 can be disposed. Thereby, it has been confirmed that an LED light source LS1 that emits about 5% higher luminous flux can be obtained.

(実施の形態2)
以下に、図4及び図5を参照して、本発明の実施の形態2に係るLED光源について説明する。図4は本実施の形態に係るLED光源LS2を上からみた状態が示されている。LED光源LS2は上述の実施の形態1に係るLED光源LS1において、蛍光体層FL1が蛍光体層FL2に置き換えられている。具体的には、蛍光体層FL1の底部が円形状に形成されているのに対して、蛍光体層FL2の底部は星形状に形成されている。なお、底部における最大距離を蛍光体層FL2の幅W2と呼ぶ。本例においては、蛍光体層FL2の底部は、4つの頂点が中心に向かって凹んだ曲線で結ばれた四角星形状の平面輪郭を有している。つまり、蛍光体層FL2は、四角星錐状に形成されている。よって、LED光源LS2をXY平面で切った時の蛍光体層FL2の平面輪郭は、蛍光体層高Hに応じて変化する。
(Embodiment 2)
Below, with reference to FIG.4 and FIG.5, the LED light source which concerns on Embodiment 2 of this invention is demonstrated. FIG. 4 shows a state in which the LED light source LS2 according to the present embodiment is viewed from above. The LED light source LS2 is the same as the LED light source LS1 according to Embodiment 1 described above, except that the phosphor layer FL1 is replaced with the phosphor layer FL2. Specifically, the bottom of the phosphor layer FL1 is formed in a circular shape, whereas the bottom of the phosphor layer FL2 is formed in a star shape. The maximum distance at the bottom is called the width W2 of the phosphor layer FL2. In the present example, the bottom of the phosphor layer FL2 has a quadrangular star-shaped planar outline connected by a curve in which four vertices are recessed toward the center. That is, the phosphor layer FL2 is formed in a square star cone shape. Therefore, the planar contour of the phosphor layer FL2 when the LED light source LS2 is cut along the XY plane changes according to the phosphor layer height H.

次に、図4に示す蛍光体層FL2の底部の輪郭形状を示す図5を参照して、蛍光体層FL2の平面輪郭形状について説明する。なお、同図においては、図4に示した蛍光体層FL2の約右四分の一が示されている。蛍光体層FL2は、LEDチップ11の2つの端面11a及び11bから発せられる光を効率的に蛍光体層FL2外側の空気層へ出射するために、LEDチップ11の中心Oの方向へくぼんだ輪郭形状を有する。蛍光体層FL2の幅W2は、例えばLEDチップ11の長さaの約1.5倍〜10倍(1.5a≦W2≦10a)程度大きく設計すれば良く、1.5倍〜3倍未満(1.5a≦W2<3a)であることが好ましい。   Next, the planar contour shape of the phosphor layer FL2 will be described with reference to FIG. 5 showing the contour shape of the bottom portion of the phosphor layer FL2 shown in FIG. In the figure, the right quarter of the phosphor layer FL2 shown in FIG. 4 is shown. The phosphor layer FL2 has a contour recessed in the direction of the center O of the LED chip 11 in order to efficiently emit light emitted from the two end faces 11a and 11b of the LED chip 11 to the air layer outside the phosphor layer FL2. Has a shape. The width W2 of the phosphor layer FL2 may be designed to be about 1.5 times to 10 times (1.5a ≦ W2 ≦ 10a) of the length a of the LED chip 11, for example, 1.5 times to less than 3 times. It is preferable that (1.5a ≦ W2 <3a).

蛍光体層FL2の幅W2がLEDチップ11の長さaの1.5倍以上10倍以下(1.5a≦W2≦10a)であれば、LEDチップ11より発せられた青色光および、蛍光体粒子FPで変換された黄色光が蛍光体層FL2よりの出射条件が満足することにより、蛍光体層FL2内で反射する回数が少なく、光路長も短くなるため、光の減衰によるLED光源LS2としての発光ロスを抑えることができる。さらに、蛍光体層FL2の幅W2がLEDチップ11の長さaの1.5倍以上3倍以下(1.5a≦W2≦3a)であれば、蛍光体層FL2の高さがLEDチップ11の長さaに対して低いため、蛍光体層FL2は曲がりにくく折れにくいので、蛍光体層FL2の形成が容易になり、蛍光体層FL2を複数作成する場合に一定の形状を得ることができるため、LED光源LS2(蛍光体層FL2)から出射する光の輝度のばらつきを抑えることができてより好ましい。   If the width W2 of the phosphor layer FL2 is 1.5 to 10 times the length a of the LED chip 11 (1.5a ≦ W2 ≦ 10a), the blue light emitted from the LED chip 11 and the phosphor Since the yellow light converted by the particles FP satisfies the emission condition from the phosphor layer FL2, the number of times it is reflected in the phosphor layer FL2 is reduced and the optical path length is also shortened, so that the LED light source LS2 due to light attenuation is obtained. Luminescence loss can be suppressed. Furthermore, if the width W2 of the phosphor layer FL2 is 1.5 to 3 times the length a of the LED chip 11 (1.5a ≦ W2 ≦ 3a), the height of the phosphor layer FL2 is the LED chip 11. Since the phosphor layer FL2 is difficult to bend and bend easily, the formation of the phosphor layer FL2 is facilitated, and a certain shape can be obtained when a plurality of phosphor layers FL2 are formed. Therefore, it is more preferable that the variation in the luminance of the light emitted from the LED light source LS2 (phosphor layer FL2) can be suppressed.

幅W2がLEDチップ11の長さaの1.5倍未満(W<1.5a)の場合の、蛍光体層FL2の形状はLEDチップ11と蛍光体層FL2の輪郭形状(蛍光体層輪郭)Lfl2(図4に示す蛍光体層FL2の底部の輪郭形状)との距離L2(同一XY平面上でのLEDチップ11の角と輪郭形状Lfl2との距離)が極めて小さくなるため、輪郭形状Lfl2の表面精度の影響で、反射時の乱反射成分が多くなり、LED光源LS2としての発光ロスが増加する。図5に示す例では、LEDチップ11の寸法(a×b×h)が約0.3mm×約0.3mm×0.1mmのときに、蛍光体層FL2の幅W2は約0.25mm〜1.5mm(例えば0.5mm)である。さらに、蛍光体層FL2の輪郭形状Lfl2は、この直交するX軸、Y軸を漸近線とする直角双曲線の一つに相当する輪郭を有する形状を備えているとなお良く、その際の輪郭形状Lfl2とLEDチップ11との距離L2は、0以上且つチップ長さaの3倍未満(0≦L2<3a)が好ましく、2倍未満(0≦L2<2a)がより好ましい。   When the width W2 is less than 1.5 times the length a of the LED chip 11 (W <1.5a), the shape of the phosphor layer FL2 is the contour shape of the LED chip 11 and the phosphor layer FL2 (the phosphor layer contour). ) Since the distance L2 (the distance between the corner of the LED chip 11 and the contour shape Lfl2 on the same XY plane) with Lfl2 (the contour shape of the bottom of the phosphor layer FL2 shown in FIG. 4) is extremely small, the contour shape Lfl2 Due to the influence of the surface accuracy, the irregular reflection component at the time of reflection increases, and the light emission loss as the LED light source LS2 increases. In the example shown in FIG. 5, when the dimension (a × b × h) of the LED chip 11 is about 0.3 mm × about 0.3 mm × 0.1 mm, the width W2 of the phosphor layer FL2 is about 0.25 mm˜ 1.5 mm (for example, 0.5 mm). Further, the contour shape Lfl2 of the phosphor layer FL2 is preferably provided with a shape having a contour corresponding to one of the right-angled hyperbola with the orthogonal X axis and Y axis asymptotic lines. The distance L2 between Lfl2 and the LED chip 11 is preferably 0 or more and less than 3 times the chip length a (0 ≦ L2 <3a), more preferably less than 2 times (0 ≦ L2 <2a).

輪郭形状Lfl2とLEDチップ11との距離L2がチップ長さaの2倍以上(L2≧2a)になると、LEDチップ11より発せられた青色光および、蛍光体粒子FPで変換された黄色光が蛍光体層FL2よりの出射条件が満足しないことにより、蛍光体層FL2内で反射する回数が増加し、光路長も長くなるため、減衰よるLED光源LS2としての発光ロスが距離L2に応じて急激に増加する。さらに距離L2が、チップ長さaの3倍以上(L2≧3a)になると、蛍光体層FL2とLEDチップ11の線膨張差で生じる応力により、LEDチップ11へのダメージが発生しやすくなる。   When the distance L2 between the contour shape Lfl2 and the LED chip 11 is more than twice the chip length a (L2 ≧ 2a), blue light emitted from the LED chip 11 and yellow light converted by the phosphor particles FP are generated. When the emission condition from the phosphor layer FL2 is not satisfied, the number of times of reflection in the phosphor layer FL2 increases and the optical path length also increases, so that the light emission loss as the LED light source LS2 due to attenuation rapidly increases according to the distance L2. To increase. Further, when the distance L2 is three times or more of the chip length a (L2 ≧ 3a), the LED chip 11 is easily damaged by the stress generated by the difference in linear expansion between the phosphor layer FL2 and the LED chip 11.

本実施形態においても、蛍光体層FL2の平面形状が、LEDチップ11の2つの側面から発せられる光の強度分布をより反映させた状態(配光角が一致)で且つより高効率で出射することができる構造となっており、すなわち、空気層への光の出射効率を高めることができる。結果、約5%〜10%高い光束を出射するLED光源LS2を得られることが確認された。   Also in the present embodiment, the planar shape of the phosphor layer FL2 emits light with higher efficiency in a state that more closely reflects the intensity distribution of light emitted from the two side surfaces of the LED chip 11 (the light distribution angles match). In other words, the light emission efficiency to the air layer can be increased. As a result, it was confirmed that an LED light source LS2 that emits a luminous flux about 5% to 10% higher can be obtained.

(実施の形態3)
以下に、図6及び図7を参照して、本発明の実施の形態3に係るLED光源について説明する。図6は本実施の形態に係るLED光源を上から見た様子が示している。LED光源LS3は上述の実施の形態2に係るLED光源LS2において、LEDチップ11及び蛍光体層FL2がそれぞれLEDチップ11cと蛍光体層FL3とに置き換えられている。具体的には、蛍光体層FL2の底部が四角星形状の輪郭を有しているのに対して、蛍光体層FL3は、六角星の6つの頂点が中心に向かって凹んだ曲線で結ばれた六角星形状の平面輪郭を有している。なお、底部における最大距離を蛍光体層FL3の幅W3と呼ぶ。また、LEDチップ11が四角柱状に形成されているのに対して、LEDチップ11cは六角柱状に形成されている。
(Embodiment 3)
Below, with reference to FIG.6 and FIG.7, the LED light source which concerns on Embodiment 3 of this invention is demonstrated. FIG. 6 shows the LED light source according to the present embodiment as viewed from above. The LED light source LS3 is the same as the LED light source LS2 according to Embodiment 2 described above, except that the LED chip 11 and the phosphor layer FL2 are replaced with the LED chip 11c and the phosphor layer FL3, respectively. Specifically, the bottom of the phosphor layer FL2 has a quadrilateral star-shaped outline, whereas the phosphor layer FL3 is connected by a curve in which six vertices of hexagonal stars are recessed toward the center. It has a hexagonal star-shaped planar outline. The maximum distance at the bottom is referred to as the width W3 of the phosphor layer FL3. Further, the LED chip 11 is formed in a quadrangular column shape, whereas the LED chip 11c is formed in a hexagonal column shape.

次に、図7を参照してLEDチップ11cの形状および、蛍光体層FL3の平面輪郭形状について説明する。図7においては、LEDチップ11cの中心をO’と定義し、O’とLEDチップ11cの一辺の中点を通る方向にのびる軸をX’軸、LEDチップ11cの中心O’と前述の一辺と隣り合う辺の中点を通る方向にのびる軸をY’軸とする。蛍光体層FL3の平面輪郭の一辺は、LEDチップ11cの2つの端面S11a及びS11bから発せられる光を効率的に蛍光体層FL3の外側の空気層へ出射するために、LEDチップ11の中心O’の方向に凹んだ輪郭形状を有する。   Next, the shape of the LED chip 11c and the planar contour shape of the phosphor layer FL3 will be described with reference to FIG. In FIG. 7, the center of the LED chip 11c is defined as O ′, the axis extending in the direction passing through the midpoint of one side of the LED chip 11c is the X ′ axis, and the center O ′ of the LED chip 11c is the one side described above. The axis extending in the direction passing through the midpoint of the adjacent side is defined as the Y ′ axis. One side of the planar outline of the phosphor layer FL3 is formed so that the light emitted from the two end faces S11a and S11b of the LED chip 11c is efficiently emitted to the air layer outside the phosphor layer FL3. It has a contour shape that is recessed in the 'direction.

蛍光体層FL3の幅W3は、例えばLEDチップ11cの六角形の一辺の長さa’の約1.5倍〜10倍(1.5a’≦W3≦10a’)程度に設計すれば良く、1.5倍〜3倍未満(1.5a’≦W3<3a’)であることが好ましい。幅W3が長さa’の1.5倍以上10倍以下(1.5a’≦W3≦10a’)であれば、LEDチップ11cより発せられた青色光および、蛍光体粒子FPで変換された黄色光が蛍光体層FL3内で反射する回数を少なくでき、光路長も短くなるため、光の減衰によるLED光源LS3の発光ロスを抑えることができて良い。幅W3がa’の1.5倍以上3倍以下(1.5a’≦W3≦3a’)であれば、さらに蛍光体層FL3の形成が容易になる。よって、蛍光体層FL3を複数作成する場合にも一定の形状を得ることができ、そして、蛍光体層LS3(蛍光体層FL3)から出射する光のばらつきを抑えることができてより好ましい。   The width W3 of the phosphor layer FL3 may be designed to be, for example, about 1.5 times to 10 times (1.5a ′ ≦ W3 ≦ 10a ′) the length a ′ of one side of the hexagon of the LED chip 11c. The ratio is preferably 1.5 times to less than 3 times (1.5a ′ ≦ W3 <3a ′). If the width W3 is 1.5 times to 10 times the length a ′ (1.5a ′ ≦ W3 ≦ 10a ′), the light is converted by the blue light emitted from the LED chip 11c and the phosphor particles FP. Since the number of times yellow light is reflected in the phosphor layer FL3 can be reduced and the optical path length is shortened, the light emission loss of the LED light source LS3 due to light attenuation can be suppressed. If the width W3 is not less than 1.5 times and not more than 3 times a '(1.5a'≤W3≤3a'), the formation of the phosphor layer FL3 is further facilitated. Therefore, it is more preferable that a certain shape can be obtained even when a plurality of phosphor layers FL3 are formed, and variation in light emitted from the phosphor layer LS3 (phosphor layer FL3) can be suppressed.

幅W3が長さa’の1.5倍未満(W3<1.5a’)の場合、LEDチップ11cと蛍光体層FL3の輪郭形状(蛍光体層輪郭)Lfl3との距離が極めて近くなるため、輪郭形状Lfl3の表面精度の影響で、反射時の乱反射成分が多くなり、LED光源LS3の発光ロスが増加する。図7に示した例では、長さa’が約0.15mmのときに、幅W3は約0.45mm〜0.9mm(例えば0.5mm)である。   When the width W3 is less than 1.5 times the length a ′ (W3 <1.5a ′), the distance between the LED chip 11c and the contour shape (phosphor layer contour) Lfl3 of the phosphor layer FL3 is extremely short. Due to the influence of the surface accuracy of the contour shape Lfl3, irregular reflection components at the time of reflection increase, and the light emission loss of the LED light source LS3 increases. In the example shown in FIG. 7, when the length a 'is about 0.15 mm, the width W3 is about 0.45 mm to 0.9 mm (for example, 0.5 mm).

また、蛍光体層FL3の輪郭形状は、X’軸及びY’軸の2軸を漸近線とする双曲線の一つに相当する輪郭を有する形状を備えているとなお良く、その際の輪郭形状Lfl3とLEDチップ11cとの距離L3は、0から長さa’の3倍未満(0<L3<3a’)が好ましく、2倍未満(0<L3<2a’)がより好ましい。距離L3が長さa’の2倍以上(L3≧2a’)であると、蛍光体層FL3とLEDチップ11cの線膨張差で生じる応力により、LEDチップ11cでダメージが発生しやすくなる。さらに距離L3が、長さa’の3倍以上(L3≧3a’)であるとLEDチップ11cより発せられた青色光がおよび、蛍光体粒子FPで変換された黄色光が蛍光体層FL3よりの出射条件が満足しないことにより、蛍光体層FL3内で反射する回数が増加し、光路長も長くなるため、減衰によるLED光源LS3の発光ロスが増加する。   Further, the contour shape of the phosphor layer FL3 is preferably provided with a shape having a contour corresponding to one of hyperbolic curves having two axes of the X ′ axis and the Y ′ axis asymptotic lines. The distance L3 between Lfl3 and the LED chip 11c is preferably from 0 to less than 3 times the length a ′ (0 <L3 <3a ′), and more preferably less than 2 times (0 <L3 <2a ′). When the distance L3 is at least twice the length a ′ (L3 ≧ 2a ′), the LED chip 11c is likely to be damaged by the stress generated by the difference in linear expansion between the phosphor layer FL3 and the LED chip 11c. Further, when the distance L3 is at least three times the length a ′ (L3 ≧ 3a ′), the blue light emitted from the LED chip 11c and the yellow light converted by the phosphor particles FP are from the phosphor layer FL3. Since the number of times of reflection in the phosphor layer FL3 increases and the optical path length increases, the light emission loss of the LED light source LS3 due to attenuation increases.

なお、説明の簡便化のために、LEDチップ11cが六角柱状形状を例として説明しているが、LEDチップ11cは六角柱状に限定されずN(N≧3)角形柱であっても良い。LED光源LS3においても、蛍光体層FL3の平面形状は、N角形柱状のLEDチップ11cのN個の側面から発せられる光の強度分布をより反映させた状態で、且つより高効率で出射することができるように構成されている。すなわち、空気層への光の出射効率を高めた蛍光体層FL3を配置できる。したがって、約5%〜10%高い光束を出射するLED光源LS3を得られることが確認されている。   For simplicity of explanation, the LED chip 11c has been described as an example of a hexagonal column shape, but the LED chip 11c is not limited to a hexagonal column shape, and may be an N (N ≧ 3) square column. In the LED light source LS3 as well, the planar shape of the phosphor layer FL3 is more efficiently reflected in a state that more closely reflects the intensity distribution of light emitted from the N side surfaces of the N-square columnar LED chip 11c. It is configured to be able to. That is, the phosphor layer FL3 with improved light emission efficiency to the air layer can be disposed. Therefore, it has been confirmed that an LED light source LS3 that emits a luminous flux that is about 5% to 10% higher can be obtained.

上述の各実施の形態に係る、LED光源LS1、LS2及びLS3は、LED光源LSと総称する。同様に、蛍光体層FL1、FL2、及びFL3は、蛍光体層FLと総称される。透光性樹脂TR1、TR2、及びTR3は、透光性樹脂TRと総称される。幅W1、W2、及びW3は、幅Wと総称される。蛍光体層輪郭Lfl1、Lfl2、及びLfl3は、蛍光体層輪郭Lflと総称される。   The LED light sources LS1, LS2, and LS3 according to the above-described embodiments are collectively referred to as LED light sources LS. Similarly, the phosphor layers FL1, FL2, and FL3 are collectively referred to as a phosphor layer FL. Translucent resins TR1, TR2, and TR3 are collectively referred to as translucent resin TR. The widths W1, W2, and W3 are collectively referred to as the width W. The phosphor layer contours Lfl1, Lfl2, and Lfl3 are collectively referred to as a phosphor layer contour Lfl.

上述のように、本発明によれば、光の取り出し効率を向上させたLED光源を提供できる。本発明により光の取り出し効率を向上させたLED光源は、高効率なLED照明やフィールドで用いる大型ディスプレイ等の用途に適用できる。   As described above, according to the present invention, an LED light source with improved light extraction efficiency can be provided. The LED light source with improved light extraction efficiency according to the present invention can be applied to applications such as high-efficiency LED lighting and large displays used in the field.

本発明は、LED光源の光取り出し効率の向上に利用できる。   The present invention can be used to improve the light extraction efficiency of an LED light source.

LS1、LS2、LS3 LED光源
FL1、FL2、FL3 蛍光体層
D 蛍光体層の底部直径
W1、W2、W3 蛍光体層の幅
H 透光性樹脂(蛍光体層)の高さ
a、a’ LEDチップの長さ
h LEDチップの厚み
FP 蛍光体粒子
L1、L2、L3 、LEDチップと蛍光体層境界面との距離
O、O’ LEDチップの中心
11 LEDチップ
12 配線基板
13 接着剤
14 ボンディングワイヤ
15 蛍光体層
111 LEDチップ発光部
112 LEDチップ電極
121、122 基板電極
121a、122a 上面電極
121b、122b 側面電極
121c、122c 下面電極
151 透光性樹脂
LS1, LS2, LS3 LED light source FL1, FL2, FL3 phosphor layer D bottom diameter of phosphor layer W1, W2, W3 width of phosphor layer H height of translucent resin (phosphor layer) a, a ′ LED Chip length h LED chip thickness FP phosphor particles L1, L2, L3, distance between LED chip and phosphor layer interface O, O ′ center of LED chip 11 LED chip 12 wiring board 13 adhesive 14 bonding wire DESCRIPTION OF SYMBOLS 15 Phosphor layer 111 LED chip light emission part 112 LED chip electrode 121,122 Substrate electrode 121a, 122a Upper surface electrode 121b, 122b Side surface electrode 121c, 122c Lower surface electrode 151 Translucent resin

Claims (7)

配線基板上に実装されたLEDチップと、
前記LEDチップを覆う蛍光体層とを備え、
前記蛍光体層は、前記LEDチップから出射された光の波長をより長い波長に変換する蛍光体粒子と、透過性樹脂とを含み、
前記蛍光体層の断面輪郭が前記LEDチップの中心方向に凹んだ曲線で形成されていることを特徴とするLED光源。
An LED chip mounted on a wiring board;
A phosphor layer covering the LED chip,
The phosphor layer includes phosphor particles that convert the wavelength of light emitted from the LED chip into a longer wavelength, and a transmissive resin.
The LED light source, wherein a cross-sectional contour of the phosphor layer is formed by a curve that is recessed in the center direction of the LED chip.
前記輪郭と前記LEDチップとの距離は、前記LEDチップの厚みの3倍未満であることを特徴とする請求項1に記載のLED光源。   The LED light source according to claim 1, wherein a distance between the contour and the LED chip is less than three times a thickness of the LED chip. 前記蛍光体層の高さは、前記LEDチップの厚みの1.5倍以上且つ10倍以下であり、前記蛍光体層の幅は、前記LEDチップの縦断面における一片の長さの1.5倍以上且つ10倍以下であることを特徴とする、請求項1及び請求項2のいずれか1項に記載のLED光源。   The height of the phosphor layer is not less than 1.5 times and not more than 10 times the thickness of the LED chip, and the width of the phosphor layer is 1.5 of the length of one piece in the longitudinal section of the LED chip. The LED light source according to any one of claims 1 and 2, wherein the LED light source is not less than 10 times and not more than 10 times. 前記蛍光体層の高さは、前記LEDチップの厚みの1.5倍以上且つ3倍以下であり、前記蛍光体層の幅は、前記LEDチップの縦断面における一片の長さの1.5倍以上且つ3倍以下である請求項1及び請求項2のいずれか1項に記載のLED光源。   The height of the phosphor layer is not less than 1.5 times and not more than 3 times the thickness of the LED chip, and the width of the phosphor layer is 1.5 of the length of one piece in the longitudinal section of the LED chip. 3. The LED light source according to claim 1, wherein the LED light source is not less than 3 times and not more than 3 times. 前記蛍光体層の断面輪郭は前記LEDチップの上面に対して垂直な方向に関して、双曲線で形成されていることを特徴とする請求項1乃至請求項4のいずれか1項に記載のLED光源。   5. The LED light source according to claim 1, wherein a cross-sectional contour of the phosphor layer is formed as a hyperbola with respect to a direction perpendicular to the upper surface of the LED chip. 前記LEDチップの上面に対して垂直な方向から見た、前記蛍光体層の断面輪郭は双曲線で囲まれることを特徴とする請求項1乃至請求項5のいずれか1項に記載のLED光源。   The LED light source according to any one of claims 1 to 5, wherein a cross-sectional contour of the phosphor layer viewed from a direction perpendicular to the upper surface of the LED chip is surrounded by a hyperbola. 前記LEDチップの上面に対して垂直な方向から見た、前記LEDチップの平面形状は多角形であることを特徴とする請求項5乃至請求項6のいずれか1項に記載のLED光源。   The LED light source according to any one of claims 5 to 6, wherein the planar shape of the LED chip viewed from a direction perpendicular to the upper surface of the LED chip is a polygon.
JP2011156190A 2011-07-15 2011-07-15 Led light source Withdrawn JP2013026244A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109087982A (en) * 2017-06-14 2018-12-25 光宝光电(常州)有限公司 Ultraviolet LED encapsulating structure and its manufacturing method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109087982A (en) * 2017-06-14 2018-12-25 光宝光电(常州)有限公司 Ultraviolet LED encapsulating structure and its manufacturing method

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