JP2015156324A

JP2015156324A - Vehicle lighting appliance

Info

Publication number: JP2015156324A
Application number: JP2014031152A
Authority: JP
Inventors: 文弥大塚; Fumiya Otsuka
Original assignee: Stanley Electric Co Ltd
Current assignee: Stanley Electric Co Ltd
Priority date: 2014-02-20
Filing date: 2014-02-20
Publication date: 2015-08-27

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle lighting appliance which is reducible in costs and size by reducing the number of part items and assembling man-hours by eliminating a heat sink.

SOLUTION: A vehicle lighting appliance comprises an LED 1 being a light source, an LED base board 2 mounted with the LED 1, and a reflector 4 which reflects light emitted from an LED 1. In the LED base board 2, copper foils 7, 8 and insulation films 9, 10 are sequentially laminated on both faces of the LED base board with an insulation plate 6 sandwiched therebetween, thicknesses of the copper foils 7, 8 are set equal to or thicker than 0.1 mm, the LED 1 is mounted on one copper foil 8, both the copper foils 7, 8 are electrically connected to each other through a plurality of via holes 11 which penetrate the LED base board 2, and a face which is mounted with the LED 1 of the LED base board 2 is made to closely adhere to the reflector 4.

Description

本発明は、ＬＥＤ（発光ダイオード）を光源とする車両用灯具に関するものである。 The present invention relates to a vehicular lamp using an LED (light emitting diode) as a light source.

ヘッドランプ等の車両用灯具の光源には、発光効率が高くて省電力、高寿命であるＬＥＤが従来のバルブ（電球）に代えて使用されつつあるが、ＬＥＤは、発光すると高い熱を発生する。ＬＥＤが発熱してその温度が高くなると、該ＬＥＤの発光効率が低下して車両用灯具全体の光度が低下する他、ＬＥＤが劣化してその寿命も低下するという問題が発生する。 As light sources for vehicle lamps such as headlamps, LEDs with high luminous efficiency, low power consumption, and long life are being used instead of conventional bulbs, but LEDs generate high heat when they emit light. To do. When an LED generates heat and its temperature increases, the luminous efficiency of the LED decreases and the luminous intensity of the entire vehicular lamp decreases. In addition, the LED deteriorates and its lifetime decreases.

そこで、ＬＥＤを冷却してその温度上昇を抑える冷却構造が従来から種々提案されている。例えば、図４の斜視図に示すように、複数（図示例では、４つ）のＬＥＤ１０１が実装されたＬＥＤ基板１０２に熱伝導性グリス１０３を介して金属製のヒートシンク（放熱板）１０４を密着させ、これらのＬＥＤ基板１０２とヒートシンク１０４を２本のネジ１０５によってリフレクタ１０６に取り付ける構成が提案されている。このような冷却構造によれば、ＬＥＤ１０１が発生する熱は、ヒートシンク１０４とリフレクタ１０６に伝導し、これらのヒートシンク１０４とリフレクタ１０６から周囲に放熱されるため、ＬＥＤ１０１が冷却されてその温度上昇が低く抑えられる。 Therefore, various cooling structures that cool the LEDs and suppress the temperature rise have been proposed. For example, as shown in the perspective view of FIG. 4, a metal heat sink (heat radiating plate) 104 is closely attached to the LED substrate 102 on which a plurality of (in the illustrated example, four) LEDs 101 are mounted via a thermally conductive grease 103. Then, a configuration in which the LED substrate 102 and the heat sink 104 are attached to the reflector 106 with two screws 105 has been proposed. According to such a cooling structure, the heat generated by the LED 101 is conducted to the heat sink 104 and the reflector 106 and is dissipated from the heat sink 104 and the reflector 106 to the surroundings. Therefore, the LED 101 is cooled and its temperature rise is low. It can be suppressed.

又、特許文献１には、図５に示すような車両用灯具が提案されている。 Patent Document 1 proposes a vehicular lamp as shown in FIG.

即ち、図５は特許文献１において提案された車両用灯具要部の断面図であり、図示の車両用灯具においては、ネジ２０１によってハウジング２０２に取り付けられたヒートシンク２０３の上面にリフレクタ２０４を密着させ、下面にＬＥＤ基板２０５を密着させ、両者をネジ２０６による共締めによってリフレクタ２０４に固定している。ここで、ＬＥＤ基板２０５は、絶縁板２０７の両面に導電膜２０８，２０９を形成し、導電膜２０８上にＬＥＤ２１０を実装するとともに、両導電膜２０８，２０９同士を複数のビア（スルーホール）２１１によって電気的に接続するとともに、ＬＥＤ基板２０５を絶縁層２１２を介してヒートシンク２０３に密着させている。 That is, FIG. 5 is a cross-sectional view of the main part of the vehicle lamp proposed in Patent Document 1. In the illustrated vehicle lamp, the reflector 204 is brought into close contact with the upper surface of the heat sink 203 attached to the housing 202 by the screw 201. The LED substrate 205 is brought into close contact with the lower surface, and both are fixed to the reflector 204 by tightening with screws 206. Here, in the LED substrate 205, the conductive films 208 and 209 are formed on both surfaces of the insulating plate 207, the LED 210 is mounted on the conductive film 208, and the conductive films 208 and 209 are connected to each other with a plurality of vias (through holes) 211. The LED substrate 205 is brought into close contact with the heat sink 203 through the insulating layer 212.

斯かる車両用灯具においては、ＬＥＤ２１０が発生する熱の一部は、輻射熱としてリフレクタ２０４に伝導して該リフレクタ２０４の表面から放熱される。又、他の熱は、ヒートシンク２０３とＬＥＤ基板２０５に伝導し、これらのヒートシンク２０３とＬＥＤ基板２０５の表面から周囲に放熱される。 In such a vehicular lamp, part of the heat generated by the LED 210 is conducted to the reflector 204 as radiant heat and is radiated from the surface of the reflector 204. Further, other heat is conducted to the heat sink 203 and the LED substrate 205 and is radiated from the surfaces of the heat sink 203 and the LED substrate 205 to the surroundings.

特開２０１０−１８２４８６号公報JP 2010-182486 A

しかしながら、図４に示す従来の車両用灯具及び図５に示す特許文献１において提案された車両用灯具には、何れもヒートシンク１０４，２０３が使用されているため、部品点数やヒートシンク１０４，２０３の組付工数が増えるためにコストアップを招くという問題がある。又、ヒートシンク１０４，２０３のサイズが大きくなると、車両用灯具全体が大型化するという問題もある。 However, since both the conventional vehicle lamp shown in FIG. 4 and the vehicle lamp proposed in Patent Document 1 shown in FIG. 5 use the heat sinks 104 and 203, the number of parts and the heat sinks 104 and 203 There is a problem that the cost increases due to the increase in the number of assembly steps. Further, when the size of the heat sinks 104 and 203 is increased, there is a problem that the entire vehicle lamp is increased in size.

本発明は上記問題に鑑みてなされたもので、その目的とする処は、ヒートシンクを廃して部品点数や組付工数を削減することによってコストダウンと小型化を図ることができる車両用灯具を提供することにある。 The present invention has been made in view of the above problems, and the object of the present invention is to provide a vehicular lamp that can be reduced in cost and size by eliminating the heat sink and reducing the number of parts and the number of assembly steps. There is to do.

上記目的を達成するため、請求項１記載の発明は、光源であるＬＥＤと、該ＬＥＤを実装したＬＥＤ基板と、前記ＬＥＤから出射する光を反射させるリフレクタを備える車両用灯具において、
前記ＬＥＤ基板を、間に絶縁板を挟んでその両面に銅箔と絶縁膜を順次積層するとともに、前記銅箔の厚さを０．１ｍｍ以上に設定し、
一方の銅箔上に前記ＬＥＤを実装し、当該ＬＥＤ基板を貫通する複数のビアによって両銅箔同士を電気的に接続し、
前記ＬＥＤ基板の前記ＬＥＤが実装された側の面を前記リフレクタに密着させたことを特徴とする。 In order to achieve the above object, an invention according to claim 1 is an automotive lamp comprising an LED as a light source, an LED substrate on which the LED is mounted, and a reflector that reflects light emitted from the LED.
While laminating a copper foil and an insulating film sequentially on both sides of the LED substrate with an insulating plate in between, the thickness of the copper foil is set to 0.1 mm or more,
The LED is mounted on one copper foil, and the copper foils are electrically connected to each other by a plurality of vias penetrating the LED substrate,
A surface of the LED substrate on which the LED is mounted is closely attached to the reflector.

請求項２記載の発明は、請求項１記載の発明において、前記リフレクタの平面部に前記ＬＥＤ基板を密着させるとともに、該平面部に、前記ＬＥＤが臨む開口部を形成したことを特徴とする。 The invention according to claim 2 is characterized in that, in the invention according to claim 1, the LED substrate is brought into close contact with the flat part of the reflector, and an opening part facing the LED is formed in the flat part.

請求項１記載の発明によれば、ＬＥＤ基板に０．１ｍｍ以上と従来の厚さの２倍以上の比較的厚い銅箔を２層設けたため、ＬＥＤ基板自体の熱容量が大きくなり、ＬＥＤにて発生する熱がより多くＬＥＤ基板に伝導し、該ＬＥＤ基板から効果的に放熱される。又、ＬＥＤ基板においては、ＬＥＤから一方の銅箔（ＬＥＤが実装された側の銅箔）に伝導する熱は、リフレクタへと伝導して該リフレクタの表面から放熱されるとともに、複数のビアを経て他方の銅箔へと伝導してＬＥＤ基板の表面から放熱される。これによってＬＥＤが効果的に冷却されてその温度上昇が低く抑えられ、該ＬＥＤの発光効率や耐久寿命の低下が防がれる。 According to the first aspect of the present invention, since the LED substrate is provided with two layers of a relatively thick copper foil of 0.1 mm or more and twice the conventional thickness, the heat capacity of the LED substrate itself is increased. The generated heat is more conducted to the LED substrate and effectively radiated from the LED substrate. In the LED substrate, heat conducted from the LED to one copper foil (copper foil on the side where the LED is mounted) is conducted to the reflector and dissipated from the surface of the reflector, and a plurality of vias are formed. Then, it is conducted to the other copper foil and radiated from the surface of the LED substrate. As a result, the LED is effectively cooled and its temperature rise is suppressed to a low level, and the light emission efficiency and durability of the LED are prevented from decreasing.

以上のようにＬＥＤ基板の放熱性能が高められる結果、従来必要であったヒートシンクが不要となり、部品点数や組付工数を削減して車両用灯具のコストダウンと小型化を図ることができる。 As described above, as a result of improving the heat dissipation performance of the LED substrate, a heat sink that has been conventionally required is not required, and the number of parts and the number of assembling steps can be reduced to reduce the cost and size of the vehicular lamp.

請求項２記載の発明によれば、ＬＥＤが発生する熱の一部は、ＬＥＤ基板からリフレクタへと直接伝導するとともに、輻射熱としてリフレクタに伝導して該リフレクタの表面から放熱されるため、ＬＥＤが効果的に冷却されてその温度上昇が低く抑えられる。 According to the second aspect of the present invention, part of the heat generated by the LED is directly conducted from the LED substrate to the reflector, and is conducted to the reflector as radiant heat and is radiated from the surface of the reflector. It is cooled effectively and its temperature rise is kept low.

本発明に係る車両用灯具要部の分解斜視図である。It is a disassembled perspective view of the vehicle lamp principal part which concerns on this invention. 本発明に係る車両用灯具要部の側断面図である。It is a sectional side view of the principal part of the vehicle lamp which concerns on this invention. 本発明に係る車両用灯具のＬＥＤ基板の部分断面図である。It is a fragmentary sectional view of the LED board of the vehicular lamp which concerns on this invention. 従来の車両用灯具要部の分解斜視図である。It is a disassembled perspective view of the conventional vehicle lamp principal part. 特許文献１において提案された車両用灯具要部の断面図である。It is sectional drawing of the vehicle lamp principal part proposed in patent document 1. FIG.

以下に本発明の実施の形態を添付図面に基づいて説明する。 Embodiments of the present invention will be described below with reference to the accompanying drawings.

図１は本発明に係る車両用灯具要部の分解斜視図、図２は同車両用灯具要部の側断面図、図３は同車両用灯具のＬＥＤ基板の部分断面図であり、本実施の形態に係る車両用灯具においては、図１に示すように、複数（図示例では、４つ）のＬＥＤ１が実装されたＬＥＤ基板２を２本のネジ３によってリフレクタ４に取り付けており、従来設けられていたヒートシンクは備えていない。尚、図１において、５はＬＥＤ基板２上のＬＥＤ１に駆動電流を供給するための電源コードである。 FIG. 1 is an exploded perspective view of an essential part of a vehicular lamp according to the present invention, FIG. 2 is a side sectional view of the essential part of the vehicular lamp, and FIG. 3 is a partial cross-sectional view of an LED substrate of the vehicular lamp. In the vehicular lamp according to the embodiment, as shown in FIG. 1, an LED substrate 2 on which a plurality of (in the illustrated example, four) LEDs 1 are mounted is attached to a reflector 4 with two screws 3. The provided heat sink is not provided. In FIG. 1, reference numeral 5 denotes a power cord for supplying a drive current to the LED 1 on the LED substrate 2.

上記リフレクタ４は、図２に示すように、水平な平面部４Ａと該平面部４Ａから下方に一体に延びる反射部４Ｂとで構成されており、平面部４Ａ上に前記ＬＥＤ基板２が密着した状態で２本のネジ３(図１参照)によって取り付けられている。ここで、ＬＥＤ１はＬＥＤ基板２の下面に実装されており、リフレクタ４の平面部４Ａには、各ＬＥＤ１が臨む４つ（ＬＥＤ１と同数）の開口部４ａが幅方向（図２の紙面垂直方向）に所定の間隔（ＬＥＤ１の配列ピッチ）で形成されている。尚、本実施の形態では、ＬＥＤ基板２を２本のネジ３によってリフレクタ４の平面部４Ａ上に密着した状態で取り付けたが、熱伝導率の高い接着剤等によってＬＥＤ基板２をリフレクタ４の平面部４Ａ上に接着しても良い。 As shown in FIG. 2, the reflector 4 is composed of a horizontal flat surface portion 4A and a reflecting portion 4B integrally extending downward from the flat surface portion 4A, and the LED substrate 2 is in close contact with the flat surface portion 4A. In the state, it is attached by two screws 3 (see FIG. 1). Here, the LEDs 1 are mounted on the lower surface of the LED substrate 2, and four openings 4 a (the same number as the LEDs 1) facing each LED 1 are arranged in the width direction (perpendicular to the plane of FIG. 2). ) At predetermined intervals (the arrangement pitch of the LEDs 1). In this embodiment, the LED substrate 2 is attached in a state of being in close contact with the flat portion 4A of the reflector 4 by the two screws 3. However, the LED substrate 2 is attached to the reflector 4 with an adhesive having a high thermal conductivity. You may adhere | attach on the plane part 4A.

又、リフレクタ４の反射部４Ｂは曲面状に成形されており、その内面の各ＬＥＤ１に対向する部位には、各ＬＥＤ１を焦点とする回転楕円状の反射面４ｂが形成されている。従って、リフレクタ４の反射部４Ｂの内面には、図１に示すように、ＬＥＤ１と同数の４つの反射面４ｂが幅方向に所定の間隔（ＬＥＤ１の配列ピッチ）で配置されており、各反射面４ｂにはアルミ蒸着等の反射処理が施されている。 Further, the reflector 4B of the reflector 4 is formed in a curved shape, and a spheroid reflecting surface 4b having the focus on each LED 1 is formed at a portion of the inner surface facing each LED 1. Therefore, as shown in FIG. 1, four reflecting surfaces 4b of the same number as the LEDs 1 are arranged on the inner surface of the reflecting portion 4B of the reflector 4 at a predetermined interval in the width direction (arrangement pitch of the LEDs 1). The surface 4b is subjected to a reflection treatment such as aluminum vapor deposition.

ここで、前記ＬＥＤ基板２の構成の詳細を図３に基づいて説明する。 Here, the detail of the structure of the said LED board 2 is demonstrated based on FIG.

ＬＥＤ基板２は、間に最も厚さの厚い絶縁板（プリプレグ）６を挟んでその上下面に銅箔７，８と絶縁膜（レジスト）９，１０を順次積層することによって構成されており、該ＬＥＤ基板２の下面に形成された絶縁膜１０の一部は剥がされ、その剥がされた部分に露出する下側の銅箔８の下面に各ＬＥＤ１が実装されている。そして、上側の銅箔７と下側の銅箔８とは、ＬＥＤ基板２に貫設されたビア（内周面に金属メッキを施したスルーホール）１１によって互いに電気的に接続されている。 The LED substrate 2 is configured by sequentially laminating copper foils 7 and 8 and insulating films (resist) 9 and 10 on the upper and lower surfaces with the thickest insulating plate (prepreg) 6 interposed therebetween, A part of the insulating film 10 formed on the lower surface of the LED substrate 2 is peeled off, and each LED 1 is mounted on the lower surface of the lower copper foil 8 exposed at the peeled portion. The upper copper foil 7 and the lower copper foil 8 are electrically connected to each other by vias (through holes in which the inner peripheral surface is metal-plated) 11 penetrating the LED substrate 2.

前記絶縁基板６は、例えばエポキシ樹脂によって構成されており、本実施の形態では、その厚さは１ｍｍに設定されている。又、熱伝導率の高い前記銅箔７，８には、従来から一般的に使用されているものの厚さ（０．０５ｍｍ程度）の２倍以上の厚さの比較的厚いものが使用されており、本実施の形態では、厚さ０．１４ｍｍのものが使用されている。尚、本実施の形態では、絶縁膜９，１０の厚さは、銅箔７，８よりも薄い０．０２ｍｍに設定されている。 The insulating substrate 6 is made of, for example, an epoxy resin, and in this embodiment, the thickness is set to 1 mm. Further, the copper foils 7 and 8 having high thermal conductivity are relatively thick, more than twice the thickness (about 0.05 mm) that has been generally used. In this embodiment, a thickness of 0.14 mm is used. In the present embodiment, the thickness of the insulating films 9 and 10 is set to 0.02 mm, which is thinner than the copper foils 7 and 8.

而して、不図示の電源から電源コード５（図１参照）を経てＬＥＤ基板２上の４つの各ＬＥＤ１に駆動電流が供給されると、各ＬＥＤ１が起動されて発光し、その光は図２に矢印にて示すように下方に向けて照射される。そして、各ＬＥＤ１から下方に向かう光は、リフレクタ４の反射部４Ｂに形成された回転楕円状の反射面４ｂで反射して平行光として前方（図２の左方）に向かって照射される。 Thus, when a drive current is supplied from a power source (not shown) to each of the four LEDs 1 on the LED board 2 via the power cord 5 (see FIG. 1), each LED 1 is activated and emits light. As shown by arrow 2 in FIG. And the light which goes downward from each LED1 is reflected by the spheroidal reflection surface 4b formed in the reflection part 4B of the reflector 4, and is irradiated toward the front (left side of FIG. 2) as parallel light.

上述のように各ＬＥＤ１が発光すると各ＬＥＤ１が発熱するが、各ＬＥＤ１が発生する熱の一部は、ＬＥＤ基板２からリフレクタ４へと直接伝導するとともに、輻射熱としてリフレクタ４に伝導する。ここで、本実施の形態では、ＬＥＤ基板２に０．１ｍｍ以上と従来の厚さの２倍以上の比較的厚い銅箔７，８を２層設けたため、ＬＥＤ基板２自体の熱容量が大きくなり、ＬＥＤ１にて発生する熱がより多くＬＥＤ基板２に伝導し、該ＬＥＤ基板２とリフレクタ４の表面から効果的に放熱される。 As described above, when each LED 1 emits light, each LED 1 generates heat, but part of the heat generated by each LED 1 is directly conducted from the LED substrate 2 to the reflector 4 and also conducted to the reflector 4 as radiant heat. Here, in this embodiment, since the LED board 2 is provided with two layers of relatively thick copper foils 7 and 8 that are 0.1 mm or more and twice the conventional thickness, the heat capacity of the LED board 2 itself is increased. More heat generated in the LED 1 is conducted to the LED substrate 2 and is effectively radiated from the surfaces of the LED substrate 2 and the reflector 4.

又、ＬＥＤ基板２においては、ＬＥＤ１から下側の銅箔（ＬＥＤ１が実装された側の銅箔）８に伝導する熱は、前述のようにリフレクタ４へと伝導して該リフレクタ４の表面から放熱されるとともに、複数のビア１１を経て上側の銅箔７へと伝導してＬＥＤ基板２の表面から放熱される。 Further, in the LED substrate 2, heat conducted from the LED 1 to the lower copper foil (copper foil on the side where the LED 1 is mounted) 8 is conducted to the reflector 4 as described above, and from the surface of the reflector 4. While being radiated, the heat is conducted to the upper copper foil 7 through the plurality of vias 11 and is radiated from the surface of the LED substrate 2.

以上の結果、ＬＥＤ１が効果的に冷却されてその温度上昇が低く抑えられ、該ＬＥＤ１の発光効率や耐久寿命の低下が防がれる。 As a result, the LED 1 is effectively cooled and its temperature rise is kept low, and the light emission efficiency and durability life of the LED 1 are prevented from being lowered.

而して、本実施の形態では、以上説明したようにＬＥＤ基板２の放熱性能が高められる結果、従来必要であったヒートシンクが不要となり、部品点数や組付工数を削減して当該車両用灯具のコストダウンと小型化を図ることができるという効果が得られる。 Thus, in the present embodiment, as described above, the heat dissipation performance of the LED board 2 is enhanced, so that a heat sink that has been necessary in the past is not necessary, and the number of parts and the number of assembling steps can be reduced. The effect that the cost reduction and size reduction of this can be achieved is acquired.

１ＬＥＤ
２ＬＥＤ基板
３ネジ
４リフレクタ
４Ａリフレクタの平面部
４Ｂリフレクタの反射部
４ａリフレクタの開口部
５電源コード
６絶縁板
７，８銅箔
９，１０絶縁膜
１１ビア
1 LED
2 LED board 3 Screw 4 Reflector 4A Reflector plane 4B Reflector reflection 4a Reflector opening 5 Power cord 6 Insulating plate 7, 8 Copper foil 9, 10 Insulating film 11 Via

Claims

光源であるＬＥＤと、該ＬＥＤを実装したＬＥＤ基板と、前記ＬＥＤから出射する光を反射させるリフレクタを備える車両用灯具において、
前記ＬＥＤ基板を、間に絶縁板を挟んでその両面に銅箔と絶縁膜を順次積層するとともに、前記銅箔の厚さを０．１ｍｍ以上に設定し、
一方の銅箔上に前記ＬＥＤを実装し、当該ＬＥＤ基板を貫通する複数のビアによって両銅箔同士を電気的に接続し、
前記ＬＥＤ基板の前記ＬＥＤが実装された側の面を前記リフレクタに密着させたことを特徴とする車両用灯具。 In a vehicular lamp provided with an LED as a light source, an LED substrate on which the LED is mounted, and a reflector that reflects light emitted from the LED,
While laminating a copper foil and an insulating film sequentially on both sides of the LED substrate with an insulating plate in between, the thickness of the copper foil is set to 0.1 mm or more,
The LED is mounted on one copper foil, and the copper foils are electrically connected to each other by a plurality of vias penetrating the LED substrate,
A vehicular lamp characterized in that a surface of the LED substrate on which the LED is mounted is in close contact with the reflector.

前記リフレクタの平面部に前記プリント基板を密着させるとともに、該平面部に、前記ＬＥＤが臨む開口部を形成したことを特徴とする請求項１記載の車両用灯具。
2. The vehicular lamp according to claim 1, wherein the printed circuit board is brought into close contact with a flat portion of the reflector, and an opening facing the LED is formed in the flat portion.