JP2011151059A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device achieving a light distribution without a deviation even when an LED element is used as a light source. <P>SOLUTION: The light-emitting device includes: a long heat dissipating member 2; a light-emitting body 3 mounted at the center in a width direction of the heat dissipating member 2, including a first semiconductor layer 33 of a first conductivity type, a light-emitting layer 34, and a second semiconductor layer 35 of a second conductivity type, provided with an electrode 37 of the first semiconductor layer 35 in a pair outside of the heat dissipating member 2 in the width direction, and forming a linear light source in a longitudinal direction of the heat dissipating member 2; and a lens 4 covering the light-emitting body 3 above the heat dissipating member 2, wherein a sufficient light can be emitted in a lateral direction from the light-emitting body 3 so that the light enters an inside of the lens 4 uniformly. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light-emitting device used as an alternative to lighting fixtures such as incandescent lamps, mercury lamps, and fluorescent lamps.

  As this type of light-emitting device, an external substrate as a plate-shaped heat dissipation member, a light-emitting body that is mounted on the external substrate and emits light linearly, a fluorescent lens that covers the light-emitting body on the external substrate, a fluorescent lens and a light-emitting body The inventor of the present application has proposed a vacuum heat insulating layer formed therebetween (see Patent Document 1). According to this light emitting device, the light emitting body having the LED structure can emit light linearly or in a planar shape, so that the light emitting area can be increased to increase the luminance.

Japanese Patent No. 4338768

  By the way, in the light emitting device described in Patent Document 1, when an ordinary LED element is used, the amount of light traveling from the LED element in the lateral direction is relatively small, and thus unevenness occurs in the light emitted from the light emitting device to the outside. Cheap.

  This invention is made | formed in view of the said situation, The place made into the objective is providing the light-emitting device which can be set as the light distribution which is not biased even if it uses an LED element as a light source.

  To achieve the above object, according to the present invention, a long heat dissipation member and a first conductive type first semiconductor layer, a light emitting layer, and a second conductive type second semiconductor are mounted at the center in the width direction of the heat dissipation member. A light-emitting body that includes a layer and a pair of electrodes on the outer side in the width direction of the heat-dissipating member, and that forms a linear light source in the longitudinal direction of the heat-dissipating member; And a lens for covering the light emitting device.

  According to this light emitting device, since the electrode of the first semiconductor layer is provided on the outer side in the width direction, the amount of light emitted from the light emitter in the lateral direction is ensured. As a result, light is sufficiently emitted from the light emitter in the lateral direction in addition to the upward direction, and the light is incident on the entire inner surface of the lens. Thereby, unevenness of light emitted from the light emitting device to the outside can be reduced.

  In the light-emitting device, it is preferable that the heat dissipating member has an ion generation unit that emits negative ions to the outside.

  In the above light-emitting device, the heat dissipation member may be made of a porous material, and the ion generator may be formed to cover the surface of the porous material by impregnating the heat dissipation member.

  In the light-emitting device, the ion generation unit may be formed in a layered manner on a surface of the heat dissipation member opposite to the mounting surface of the light emitter.

  In the above light emitting device, the light emitter is composed of a plurality of light emitting elements each having a rectangular shape that is long in the width direction of the heat radiating member. You may have done.

  In the light emitting device, the lens may include a fluorescent layer that emits light having a wavelength different from that of the light when excited by light emitted from the light emitter.

  In the light emitting device, the lens may include a diffusion layer that diffuses light.

  The light emitting device may include a vacuum heat insulating layer formed between the lens and the light emitter.

  According to this invention, even if it uses an LED element as a light source, it can be set as the light distribution without a bias | inclination.

FIG. 1 is an external perspective view of a light emitting device showing an embodiment of the present invention. FIG. 2 is an enlarged perspective view of the light emitting device. FIG. 3 is a cross-sectional view of the light emitting device. FIG. 4 is an enlarged perspective explanatory view of a light emitting device showing a modification. FIG. 5 is an explanatory plan view of a semiconductor wafer showing a modification. FIG. 6 is a cross-sectional view of a light emitting device showing a modification. FIG. 7 is a cross-sectional view of a light emitting device showing a modification. FIG. 8 is a cross-sectional view of a light emitting device showing a modification.

  1 to 3 show an embodiment of the present invention. FIG. 1 is an external perspective view of a light emitting device, FIG. 2 is an enlarged perspective explanatory view of the light emitting device, and FIG. 3 is a sectional view of the light emitting device.

  As shown in FIG. 1, the light emitting device 1 is formed in a long shape as a whole, and includes a plate-like external substrate 2 and a lens 4 having a semicircular cross section that covers one surface of the external substrate 2. The light emitting device 1 is provided on a ceiling, a wall surface, a stand or the like like a conventional fluorescent lamp, and radiates light emitted from a light emitter 3 (not shown in FIG. 1) to the outside through a lens 4. Although not particularly shown in FIG. 1, the external substrate 2 is usually used by being connected to a heat sink. For example, when installed on a ceiling or a wall surface, a steel frame or the like can be used as a heat sink.

  As shown in FIG. 2, the light emitting device 1 includes an external substrate 2 as a heat radiating member, a light emitter 3 mounted on the external substrate 2, a lens 4 covering the light emitter 3 on the external substrate 2, and a lens 4. And a vacuum heat insulating layer 5 formed between the light emitters 3. In the present embodiment, the light emitter 3 has a long rectangular shape in the width direction of the external substrate 2 in plan view. A plurality of light emitters 3 are arranged in the longitudinal direction of the external substrate 2 to form a linear light source as a whole.

  The external substrate 2 is an interposer, for example, and has a substrate body 21 made of an inorganic material and having excellent heat dissipation. The substrate body 21 is made of ceramic such as AlN, for example, and is formed in a square shape in plan view. A circuit pattern for supplying power to the light emitter 3 is formed on the surface of the substrate body 21. An ion generation layer 22 as an ion generation part is formed on the surface of the substrate body 21 opposite to the mounting surface of the light emitter 3. In the present embodiment, the circuit pattern of the first electrode 2a is formed on one end side in the width direction of the surface of the external substrate 2, and the circuit pattern of the second electrode 2b is formed from the center in the width direction to the other end side.

  For example, the ion generation layer 22 is formed in a layer shape by applying finely ground tourmaline, soot powder particles, or the like to the entire lower surface of the substrate body 21. The ion generation layer 22 is excited when heat generated in the light emitter 3 is transmitted through the substrate body 21 and generates a large amount of negative ions.

  As shown in FIG. 3, the light emitter 3 has a support substrate 31 and a semiconductor multilayer structure formed on the support substrate 31. In the present embodiment, the light emitter 3 is a face-up type, the support substrate 31 is sapphire, and the semiconductor laminated structure is a GaN-based material. The semiconductor stacked structure includes an n-type semiconductor layer 33, a light emitting layer 34, and a p-type semiconductor layer 35 from the support substrate 31 side, and an n-side electrode 36 and a p-side on the n-type semiconductor layer 33 and the p-type semiconductor layer 35. An electrode 37 is formed.

  In the n-type semiconductor layer 33, an exposed portion 33a is formed by removing the central side of the light emitting layer 34 and the p-type semiconductor layer 35 by etching, and an n-side electrode 36 is formed at the center in the width direction of the exposed portion 33a. . In the present embodiment, the exposed portion 33a is formed to have the same width as the p-type semiconductor layer 35 in plan view. In the present embodiment, the light emitting layer 34 is formed separately in the width direction of the external substrate 2, and the p-side electrode 37 is provided on each separated light emitting layer 34. That is, the p-side electrodes 37 are provided as a pair on the outside in the width direction of the external substrate 2.

  The n-side electrode 36 is electrically connected to the first electrode 2a on the external substrate 2 by the first wire 3a. Each p-side electrode 37 is electrically connected to the second electrode 2b on the external substrate 2 by the second wire 3b.

  Moreover, the light emitter 3 emits blue light, and has a peak wavelength of 460 nm, for example. The light emitter 3 is sealed with a transparent resin 7 such as an epoxy resin or silicone. The transparent resin 7 does not contain a phosphor, and transmits light emitted from the light emitter 3 as it is. The transparent resin 7 is preferably a resin having high heat resistance.

  As shown in FIG. 3, the lens 4 is made of a transparent material such as resin or glass, and has a fluorescent layer 41 and a diffusion layer 42 in this order from the inside. The lens 4 can also be formed of a transparent material such as fiber reinforced plastics (FRP (Fiber Reinforced Plastics)).

  The fluorescent layer 41 contains a phosphor in a transparent material. When the phosphor is excited by light emitted from the light emitter 3, the phosphor emits light having a wavelength different from that of the light. In the present embodiment, the illuminant 3 is a yellow phosphor that emits yellow light when excited by blue light. For example, YAG (Yttrium Aluminum Garnet), a silicate system, or the like is used.

  The diffusion layer 42 contains diffusion particles in the transparent material. The diffusing particles scatter light incident on the diffusion layer 42 to uniformize the intensity, chromaticity, and the like of the light emitted from the lens 4 to the outside.

The vacuum heat insulating layer 5 is formed by depressurizing a gas such as air from the atmospheric pressure. “Vacuum” as used herein does not mean a state in which no substance is present, but a state in which the gas is depressurized to the extent that it has an adiabatic action. The pressure inside the vacuum heat insulating layer 5 may be 10 ² Pa or more (low vacuum) as long as it is lower than atmospheric pressure, preferably 10 ² to 10 ⁻¹ Pa or less (medium vacuum), and 10 ⁻¹ to 10 ^{−. 5} Pa (high vacuum) is more preferable. Furthermore, the pressure inside the vacuum heat insulating layer 5 can be 10 ⁻⁵ or less (ultra-high vacuum).

  According to the light emitting device 1 configured as described above, when voltage is applied to the light emitter 3 through the first electrode 2a and the second electrode 2b of the external substrate 2, blue light is emitted from the light emitter 3, and blue light is emitted. The light enters the lens 4 directly or indirectly. Here, since the light emitting body 3 is formed with a pair of light emitting layers 34 on the outer side in the width direction of the external substrate 2, the amount of light emitted to the outer side in the width direction (lateral direction) is secured. As a result, light is sufficiently emitted from the light emitter 3 in the lateral direction in addition to the upward direction, and the light is incident on the inner surface of the lens 4 as a whole.

  Part of the blue light incident on the lens 4 is converted into yellow light by the phosphor in the phosphor layer 41. Then, since light diffuses in the diffusion layer 42 and unevenness in the amount of light and chromaticity is reduced, a mixed light of blue light and yellow light is emitted to the outside. In this way, white light is emitted from the light emitting device 1.

  As described above, in the light emitting device 1 of the present embodiment, the light emitter 3 emits light on the outer side in the width direction of the external substrate 2, so that the light is emitted from the lens 4 in the lateral direction (a direction parallel to the external substrate 2). Can be secured. Therefore, when the light emitting device 1 is installed on a ceiling, a wall surface or the like, the installation surface of the device is not sufficiently irradiated, and the light emitting device 1 does not give a dark impression to the user or the like.

  Further, heat generated in the light emitter 3 during light emission of the light emitter 3 is transmitted to the ion generation layer 22 through the substrate body 21, and negative ions are released from the ion generation layer 22. By the negative ions released from the light emitting device 1 to the outside, it is possible to obtain an effect of removing fine particles contained in tobacco smoke, a deodorizing effect, an effect of removing formaldehyde, and the like.

  Further, since the heat generated in the light emitter 3 is insulated by the vacuum heat insulating layer 5, it hardly transmits to the lens 4 side, and most of it is transmitted to the external substrate 2 side, so that negative ions are generated. Can be efficiently performed, and deterioration of the phosphor contained in the lens 4 can be suppressed. Therefore, the original long life of the LED in the light emitter 3 can be utilized without considering the deterioration of the phosphor. In addition, since heat is not transferred from the mounting portion of the light emitter 3 in the apparatus to the direction of the lens 4, when the light emitter 3 is used as a lighting fixture that illuminates the room, the irradiated body, etc., the room, the irradiated body, etc. are heated. There is no thermal effect caused by the light emitting device 1 on the room, the irradiated object, or the like. Further, since the heat dissipating member is plate-shaped, it is easy to increase the heat dissipating area, the heat dissipating performance can be improved, and the apparatus can be made thin, which is extremely advantageous in practical use.

  In the above embodiment, the light emitter 3 extends in the width direction of the external substrate 2. However, for example, as shown in FIG. 4, the light emitter 103 extends in the longitudinal direction of the external substrate 2. Also good. In the light emitting device 101 of FIG. 4, the light emitter 103 is formed by extending the light emitter 3 of the embodiment in the longitudinal direction of the external substrate 2, and a plurality of electrodes 36 and 37 are arranged in the longitudinal direction. According to the light emitting device 101, since the number of the light emitters 103 is small, variations in luminance, chromaticity and the like in each light emitter 13 can be reduced. In addition, if a light-emitting body is comprised from one elongate LED element, dispersion | variation in a brightness | luminance, chromaticity, etc. will be eliminated.

  As shown in FIG. 5, the light emitter 103 is created by cutting a disk-shaped semiconductor wafer 200 in which a semiconductor laminate is formed on a support substrate 31. On the center side of the semiconductor wafer 200, a long light emitter 103 is formed adjacent to the width direction thereof. A substantially square light emitter 201 used for the point light source LED is formed outside each light emitter 103 in the semiconductor wafer 200.

  Moreover, in the said embodiment, although the light-emitting body 3 showed what is a face-up type, for example, as shown in FIG. 6, the light-emitting body 303 may be a flip chip type. Further, the emission wavelength, material, and the like of the light emitter 3 can be arbitrarily changed. For example, the light emitter 303 may emit ultraviolet light, and the lens 4 may include a blue phosphor, a green phosphor, and a red phosphor that are excited by the ultraviolet light. Further, white light may be obtained by combining a plurality of types of light emitters having different emission wavelengths without containing a phosphor.

  In the light emitting device 301 of FIG. 6, each p-side electrode 337 on the p-type semiconductor layer 35 of the light emitter 303 is connected to the second electrode 302b of the external substrate 2 via the solder 303b. In addition, the n-side electrode 336 on the n-type semiconductor layer 33 is connected to the first electrode 302a of the external substrate 2 through the solder 303a. In the light emitting device 301, the first electrode 302 a is formed in the center in the width direction of the external substrate 2, and the second electrode 302 b is formed on the outside in the width direction of the external substrate 2.

  In the above embodiment, the ion generation layer 22 is formed on the lower surface of the external substrate 2. For example, as shown in FIG. 6, the lower side of the external substrate 2 is a porous material 322, and this porous The material may be formed by impregnating the ion generating material so as to cover the surface of the internal cavity of the material 322. In FIG. 6, the element mounting substrate 302 is composed of a non-porous material 321 on the upper side and a porous material 322 on the lower side. Thus, by impregnating the porous material with the ion generating material, the surface area of the ion generating portion can be increased and negative ions can be efficiently generated.

  In the embodiment, the n-side electrode 36 is formed on the n-type semiconductor layer 33, and the n-side electrode 36 and the first electrode 2a of the external substrate 2 are connected by the first wire 3a. For example, as shown in FIG. 7, the n-type semiconductor layer 33 and the first electrode 402a are directly and electrically connected through the support substrate 431 using a support substrate 431 of the light emitter 403 as a conductive material such as GaN. It is also possible to do. A pair of p-side electrodes 37 are formed on the p-type semiconductor layer 35 and are connected to the second electrode 402b by wires 403b. In the light emitting device 401, the first electrode 402 a is formed in the center in the width direction of the external substrate 2, and the second electrode 402 b is formed on the outer side in the width direction of the external substrate 2. The support substrate 431 of the light emitter 403 may be provided on the p-type semiconductor layer 35 side, and a wire may be connected to the n-type semiconductor layer 33 side. Further, in the light emitting device 401 of FIG. 7, the element mounting substrate 402 is made of a porous material having an ion generating portion formed on the entire surface, and the inside of the lens 4 is not in a vacuum.

  In the above embodiment, the lens 4 has a semicircular cross section. However, the shape of the lens 4 can be changed as appropriate. For example, as shown in FIG. 8, the lens 504 may be a flat plate formed of the diffusion layer 542. In the light emitting device 501 of FIG. 8, a reflector member 509 having a reflecting surface is installed on the external substrate 402, and a lens 504 is installed on the heat insulating glass 508 installed on the upper end of the reflector member 509. Also in the light emitting device 501, the amount of light emitted from the light emitter 3 in the lateral direction is ensured, light is incident on the entire inner surface of the lens 504, and unevenness of light emitted from the light emitting device 501 to the outside is reduced. Can do. In the light emitting device 501 of FIG. 8, the entire element mounting substrate 402 is made of a porous material having an ion generating portion formed on the surface, and the inside of the lens 504 is not in a vacuum.

Moreover, in the said embodiment, although what provided the fluorescent substance layer 41 in the lens 4 was shown, you may contain the fluorescent substance 71 in the sealing resin 7, as shown, for example in FIG.
Moreover, in the said embodiment, although what showed the light-emitting body 3 sealing with the sealing resin 7 was shown, the heat-resistant performance of an apparatus can further be improved by sealing the light-emitting body 3 with glass.

  In the above-described embodiment, the lens 4 has a two-layer structure including the fluorescent layer 41 and the diffusion layer 42. However, the layer configuration of the lens 4 is arbitrary. For example, the lens 4 may be a single layer of a fluorescent layer or a diffusion layer, or may be a single layer in which phosphor particles and diffusion particles are mixed, and further, a fluorescent function, a diffusion function, and ion generation. It may be one without a function or the like.

  In the above embodiment, the vacuum heat insulating layer 5 is formed between the lens 4 and the light emitter 3, but the inside of the lens 4 does not have to be evacuated, and other specific details such as a detailed structure. Of course, it can be changed appropriately.

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 External substrate 2a 1st electrode 2b 2nd electrode 3 Light emitter 3a 1st wire 3b 2nd wire 4 Lens 5 Vacuum heat insulation layer 7 Sealing resin 21 Substrate body 22 Ion generation layer 31 Support substrate 32 Semiconductor laminated body 33 n-type semiconductor layer 33a exposed portion 34 light-emitting layer 35 p-type semiconductor layer 36 n-side electrode 37 p-side electrode 41 fluorescent layer 42 diffusion layer 101 light-emitting device 103 light-emitting body 200 semiconductor wafer 201 light-emitting body 301 light-emitting device 302 element mounting substrate 302a first 1 electrode 302b second electrode 303 light emitter 321 non-polymorphic material 322 porous material 336 n side electrode 337 p side electrode 401 light emitting device 402 element mounting substrate 402a first electrode 402b second electrode 403 light emitter 403b wire 431 support substrate 501 Light emitting device 504 Lens 508 Heat insulating material 509 Reflector 542 Diffusion layer

Claims (8)

A long heat dissipation member,
The heat dissipation member is mounted at the center in the width direction, and includes a first conductive type first semiconductor layer, a light emitting layer, and a second conductivity type second semiconductor layer, and an electrode of the first semiconductor layer is located outside the heat dissipation member in the width direction. A light emitter that forms a linear light source in the longitudinal direction of the heat dissipation member;
And a lens that covers the light emitter on the heat dissipation member.   The light-emitting device according to claim 1, wherein the heat radiating member includes an ion generation unit that emits negative ions to the outside. The heat dissipation member is made of a porous material,
The light-emitting device according to claim 2, wherein the ion generation unit is formed so as to cover a surface of the porous material by impregnating the heat dissipation member.   The light-emitting device according to claim 2, wherein the ion generation unit is formed in a layered manner on a surface of the heat radiating member opposite to the mounting surface of the light emitter.   The light emitter is composed of a plurality of light emitting elements each having a rectangular shape that is long in the width direction of the heat radiating member, and the light emitting elements are aligned in the longitudinal direction of the heat radiating member to form a linear light source as a whole. 5. The light emitting device according to any one of items 1 to 4.   The light emitting device according to claim 2, wherein the lens includes a fluorescent layer that emits light having a wavelength different from that of the light when excited by light emitted from the light emitter.   The light emitting device according to claim 2, wherein the lens includes a diffusion layer that diffuses light.   The light emitting device according to claim 2, further comprising a vacuum heat insulating layer formed between the lens and the light emitter.

Images