CN101779300A - Light-emitting device - Google Patents

Abstract

A light-emitting device in which a gallium nitride upper and lower electrode type light-emitting diode is provided on a ceramic substrate on which at least a pair of insulated metal substrates or at least two package electrodes are formed. In the light-emitting device, a gallium nitride upper and lower electrode type light-emitting diode (11) is mounted on substrates (12, 14). The power of the gallium nitride upper and lower electrode type light-emitting diode (11) is connected on the substrates (12, 14), and is surrounded by a reflector (16). The reflector (16) is adhered to the substrates (12, 14) with an adhesive. Further, the reflector (16) is provided in such a manner that a fluorescent layer covers an aperture plane.

Description

light emitting device

technical field

The present invention relates to a light-emitting device in which gallium nitride-based upper and lower electrode type light-emitting diodes are disposed on at least a pair of insulated metal substrates or a ceramic substrate on which at least two substrate electrodes are formed. The present invention relates to a light-emitting device capable of passing a large current to the above-mentioned GaN-based upper and lower electrode type light-emitting diodes, taking into account heat dissipation of heat generated at this time, expansion and contraction due to thermal stress of metal parts caused by the heat, and the like. In addition, the present invention relates to a gallium nitride-based upper and lower electrode type that can prevent damage to the light-emitting layer due to vibration or heat by connecting a metal member composed of a metal plate-shaped member and solder instead of connecting a metal wire by wire bonding. A light-emitting device composed of light-emitting diodes. Furthermore, the present invention relates to a light-emitting device capable of efficiently irradiating light from the above-mentioned light-emitting portion by forming fine unevenness on the light-emitting portion on the upper surface of the above-mentioned gallium nitride-based upper and lower electrode type light-emitting diode, and without covering the upper surface with a sealing material. .

Background technique

FIG. 6 is a view for explaining a conventional example, and is an example in which upper and lower electrode type light emitting diodes are provided on a reflector. In FIG. 6 , the lower electrodes of the upper and lower electrode type light emitting diodes 61 are bonded to one metal substrate 62 . The upper electrodes of the upper and lower electrode type light emitting diodes 61 are bonded to another metal substrate 64 by wire bonding 65 , and the one metal substrate 62 and the other metal substrate 64 are separated by an insulating member 63 . The separated metal substrates 61 and 64 are integrally held by the reflector 66 . The upper and lower electrode type light emitting diodes 61 are sealed in the reflective frame 66 by a sealing material 67 . The sealing material 67 is filled on the upper surface of the reflection frame 66, and the fluorescent film 68 and the transparent protective film 69 are formed thereon.

In the light-emitting device described in Japanese Patent Application Laid-Open No. 2007-27585, a light-emitting diode is provided on a substrate, the light-emitting diode is sealed with a sealing material, and a phosphor layer is provided on the sealing material.

Filling the entire reflective frame with the sealing material described in the above-mentioned conventional examples and patent publications covers the fine unevenness of the light-emitting part, thereby hindering light scattered from the light-emitting part and efficiently irradiated.

The light-emitting diode mounted on the metal substrate having a gap shown in FIG. 6 is sealed with a transparent resin, and a hard resin is used to impart strength to the transparent resin. However, the above-mentioned sealing material with high hardness has a problem that the thermal stress generated from the light emitting diode is large. There is a possibility that the above-mentioned thermal stress may cause disconnection of the wiring that supplies power to the light-emitting diodes.

In addition, in the light-emitting device shown in FIG. 6, the sealing material and the fluorescent film, and the fluorescent film and the transparent protective film are adhered to each other in a semi-cured state. In the above-mentioned light-emitting device, although the sealing material, the fluorescent film, and the transparent protective film are each adhered to each other well, stress is generated due to shrinkage when they are in a cured state. That is, at the time of the shrinkage, the sealing material is bent. Along with the bending of the sealing material, the fluorescent film is stretched, and cracks, curls, or cracks may occur in some cases.

Contents of the invention

In order to solve the above-mentioned problems, the object of the present invention is to provide a light-emitting device in which the light-emitting part of the gallium nitride-based upper and lower electrode type light-emitting diodes has fine unevenness, so that a large amount of light can be efficiently irradiated without providing a sealing material, and light can be realized. Increased efficiency. An object of the present invention is to provide a light-emitting device in which thermal stress does not cause cracking or curling of a phosphor-containing film. An object of the present invention is to provide a light-emitting device that is excellent in mass productivity, withstands high current and thermal stress, and maintains high intensity.

The light-emitting device of the present invention is characterized in that it is at least composed of the following components: a package with a reflector and at least a pair of package electrodes on the bottom of the reflector; a gallium nitride-based upper and lower electrode type light-emitting diode, which has a p-type nitrogen There is an active layer between the gallium nitride semiconductor layer and the n-type gallium nitride semiconductor layer, an upper surface light-emitting part and a partial electrode on the upper part of the above-mentioned one semiconductor layer, and a A jointed lower electrode; a metal member that connects the upper partial electrode of the above-mentioned gallium nitride-based upper and lower electrode type light-emitting diode to the other of the above-mentioned package electrodes; the joint between one of the above-mentioned package electrodes and the above-mentioned bottom electrode Solder used for joining the upper part of the electrode to the metal member, and the metal member to the other of the package electrodes; and the phosphor layer mounted near the upper surface of the reflector, gallium nitride-based upper and lower electrode type The light-emitting portion on the upper surface of the light-emitting diode is formed with fine unevenness, and there is no sealing material on the upper surface.

The light-emitting device of the present invention is characterized in that the package includes a pair of separated metal substrates serving as package electrodes, and a reflector bonded to the pair of metal substrates.

In the light-emitting device of the present invention, the package is composed of a ceramic substrate on which at least one pair of package electrodes is formed, and a reflector bonded to the ceramic substrate.

The light-emitting device of the present invention is characterized in that the above-mentioned package is composed of a metal substrate as one of at least one pair of package electrodes, a ceramic substrate on which the other of the package electrodes is formed, and the above-mentioned metal substrate and the above-mentioned ceramic substrate. Bottom-bonded reflector construction.

The light-emitting device of the present invention is characterized in that the metal member is a gold or silver ribbon wire, or an aluminum or copper ribbon wire covered with gold and/or silver.

The light-emitting device of the present invention is characterized in that the above-mentioned reflector is composed of alumina-based, alumina-glass composite-based ceramics, etc., and is made of silicone resin-based, epoxy resin-based, polyimide resin-based, A glass-based or solder-based adhesive is bonded to the substrate.

In the light-emitting device of the present invention, the phosphor layer is bonded to a step provided on the reflector.

In the light-emitting device of the present invention, the phosphor layer is provided on a frame mounted in the opening of the reflector.

The light-emitting device of the present invention is characterized in that a plurality of the gallium nitride-based upper and lower electrode type light-emitting diodes are arranged on the bottom of the above-mentioned reflector, and the above-mentioned plurality of gallium nitride-based upper and lower electrode type light-emitting diodes are connected in series and/or in parallel. Ground bonded package electrodes.

In the light-emitting device of the present invention, a package having a reflector and at least one pair of package electrodes, a gallium nitride-based upper and lower electrode type light-emitting diode, and a metal that joins the electrodes of the gallium nitride-based upper and lower electrode type light-emitting diode to the above-mentioned package electrodes member, and a phosphor layer provided near the opening of the reflector. The above-mentioned reflector is composed of a square, circular, elliptical or other cylindrical body, and can reflect light from the inclined surface and the bottom inside. In addition, at least one pair of encapsulation electrodes is disposed on the bottom of the reflector. One or the other of the aforementioned pair of encapsulation electrodes can also serve as a common electrode.

Gallium nitride-based upper and lower electrode type light-emitting diodes, with an active layer between the p-type gallium nitride semiconductor layer and the n-type gallium nitride semiconductor layer in the middle part, and an upper surface light-emitting part and some electrodes on the upper part of the above-mentioned one semiconductor layer , the lowermost layer of the another semiconductor layer has a lower electrode joined to one of the encapsulation electrodes, and emits light from above and sideways. A metal member, for example, an elongated thin plate member, connects the upper partial electrode of the gallium nitride-based upper and lower electrode type light emitting diode to the other of the package electrodes. One of the package electrodes is joined to the lower electrode, the upper partial electrode is joined to the metal member, and the metal member is joined to the other of the package electrodes using solder. A phosphor layer is installed near the upper surface of the reflector.

In addition, the upper surface light-emitting portion of the gallium nitride-based upper and lower electrode type light-emitting diodes has fine unevenness formed on the surface. The fine unevenness on the above-mentioned surface can diffusely reflect light and improve luminous efficiency. Furthermore, since the upper surface light-emitting portion of the gallium nitride-based upper and lower electrode type light-emitting diode does not have a sealing material on its upper surface, diffuse reflection of light can be effectively irradiated, and the luminous efficiency can be further improved.

In the light-emitting device of the present invention, the package electrodes are formed of a pair of metal substrates separated from each other by a space or an insulating member. The aforementioned pair of metal substrates are integrally bonded with one reflector mounted on top of them. Since the separated metal substrate and the reflector are bonded with an adhesive or the like, sufficient strength can be obtained.

In the light-emitting device of the present invention, at least one pair of the above-mentioned encapsulation electrodes is formed on the ceramic substrate. A reflector is bonded to the ceramic substrate on which the aforementioned pair of package electrodes are formed. Since the at least one pair of package electrodes and the reflector bonded to the package electrodes do not have a separation portion, the light-emitting device is structurally strong.

The light-emitting device of the present invention differs from the above-mentioned invention in that the package is composed of a metal substrate, a ceramic substrate, and a reflector. At least one pair of encapsulation electrodes is composed of a metal substrate and an encapsulation electrode formed on the ceramic substrate. One reflector is integrally bonded to the metal substrate and the ceramic substrate.

In the light-emitting device of the present invention, the metal member is an elongated strip made of gold or silver, or an elongated strip made of aluminum, copper, or an alloy thereof coated with gold and/or silver. The above-mentioned metal member is easily bent into an arbitrary shape, has a large joining area by solder, and can improve solder wettability.

In the light-emitting device of the present invention, the reflector is formed of a member such as alumina-based, alumina-glass composite-based ceramics, or the like. The above-mentioned reflector is bonded to the above-mentioned metal substrate or the above-mentioned ceramic substrate with a silicone resin-based, epoxy-resin-based, polyimide-resin-based, glass-based, or solder-based adhesive, and is firmly fixed as a light-emitting device. .

In the light-emitting device of the present invention, the phosphor layer is bonded to the step provided on the upper portion of the reflector, and light of wavelengths from ultraviolet to blue light is emitted from the gallium nitride-based upper and lower electrode type light-emitting diodes. The above-mentioned phosphor film is a combination of a phosphor that absorbs ultraviolet rays and emits blue light, and a phosphor that absorbs ultraviolet to blue light and emits yellow light for ultraviolet light emitting diodes. In addition, the above-mentioned phosphor film can be used in combination with a phosphor that absorbs ultraviolet light and emits blue light, a phosphor that absorbs ultraviolet to blue light and emits green light, and a phosphor that absorbs ultraviolet to blue light and emits red light.

As the above-mentioned phosphor film, a phosphor that emits blue light and a phosphor that absorbs the blue light and emits yellow light are used for the blue light-emitting diode. In addition, as the phosphor film, phosphors that emit blue light, phosphors that absorb blue light and emit green light, and phosphors that absorb blue light and emit red light can be used. Furthermore, in the above-mentioned phosphor film, when a yellow phosphor is used, color rendering can be improved by blending a small amount of red-emitting phosphor.

In the light-emitting device of the present invention, the phosphor layer is incorporated into a frame, and the frame is attached near the opening of the reflector. The phosphor layer is produced in a different process from that of the package in which the gallium nitride-based upper and lower electrode type light-emitting diodes are mounted, and is not filled with a sealing material at the end, and is mounted near the opening of the reflector.

The light-emitting device of the present invention is characterized in that a plurality of gallium nitride-based upper and lower electrode type light-emitting diodes are provided on the bottom of the reflector. The package electrodes are provided so as to be able to connect the plurality of gallium nitride-based upper and lower electrode type light-emitting diodes in series and/or in parallel. One and/or the other of the aforementioned encapsulation electrodes can be shared. The light-emitting device of the present invention can irradiate intense light from one package.

According to the present invention, since the upper electrode of the gallium nitride-based upper and lower electrode type light-emitting diodes is connected to the other package electrode by means of a long metal member such as a metal wire tape, it is not necessary to seal it with a sealing material. Since the fine unevenness formed on the light-emitting portion of the upper surface of the gallium nitride-based upper and lower electrode type light-emitting diode is not covered with a sealing material, light can be irradiated efficiently by utilizing the fine unevenness.

According to the present invention, since the light-emitting device is composed of a pair of metal substrates and/or ceramic substrates, gallium nitride-based upper and lower electrode type light-emitting diodes, metal parts, reflectors, and phosphor layers mounted on the reflectors, Therefore, heat dissipation is good, a large current can flow, and light can be emitted with high brightness.

According to the present invention, since the phosphor layer is pre-attached to the phosphor layer attachment frame together with the transparent protective film, and can be attached to the reflector only by fitting, it becomes a light-emitting device excellent in mass productivity.

According to the present invention, since wire bonding and the like are not used, it is possible to obtain a light-emitting device that not only has high reliability over a long period of time, but also is low in cost and excellent in mass productivity.

According to the present invention, since the upper electrodes of the gallium nitride-based upper and lower electrode type light-emitting diodes connected to one metal substrate are connected to the other metal substrate using, for example, a plate-shaped metal member, not only can a large current flow, but also the heat dissipation is excellent. Well, even if thermal stress occurs, it can be relieved. In particular, in the present invention, when solder is used for each connecting portion, vibration is not applied to the bonding portion and/or the light emitting layer, and a light emitting diode unit composed of gallium nitride-based upper and lower electrode type light emitting diodes without defective products can be obtained.

According to the present invention, the gallium nitride-based upper and lower electrode type light-emitting diodes can be easily changed into desired colors only by changing the type of phosphor-containing film.

Description of drawings

Fig. 1 (a) to (d) are the first embodiment of the present invention, and Fig. 1 (a) is a schematic cross-sectional view for explaining the state where gallium nitride-based upper and lower electrode type light-emitting diodes are mounted on a pair of metal substrates , FIG. 1(b) is a cross-sectional view of a phosphor layer mounting frame, FIG. 1(c) is an enlarged schematic cross-sectional view of a state where a light-emitting diode is installed, and FIG. 1(d) is a plan view of a light-emitting device.

2(a) to (c) are Embodiment 2 of the present invention, and FIG. 2(a) is a cross-sectional view illustrating a state in which gallium nitride-based upper and lower electrode type light-emitting diodes are mounted on a pair of metal substrates. FIG. 2( b ) is a cross-sectional view of a phosphor layer mounting frame, and FIG. 2( c ) is a perspective view of a metal member.

3( a ) is a cross-sectional view of a light-emitting device made of a metal substrate and ceramics with packaging electrodes according to Embodiment 3 of the present invention, FIG. 3( b ) is an enlarged cross-sectional view, and FIG. 3( c) is a plan view.

4( a ) and ( b ) are enlarged plan views of the upper surfaces of the electrodes in the gallium nitride-based upper and lower electrode type light-emitting diodes of the present invention.

FIG. 5 is a comparative example for explaining an example in which the luminosity of a gallium nitride-based upper and lower electrode type light-emitting diode (blue) was measured depending on the presence or absence of a sealing material.

FIG. 6 is a view for explaining a conventional example, and is an example in which gallium nitride-based upper and lower electrode type light emitting diodes are provided on a reflector.

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

(Example 1)

Fig. 1 (a) to (d) are the first embodiment of the present invention, and Fig. 1 (a) is a schematic cross-sectional view for explaining the state where gallium nitride-based upper and lower electrode type light-emitting diodes are mounted on a pair of metal substrates , FIG. 1(b) is a cross-sectional view of a phosphor layer mounting frame, FIG. 1(c) is an enlarged schematic cross-sectional view of a state where gallium nitride-based upper and lower electrode type light-emitting diodes are mounted, and FIG. 1(d) is a light-emitting device. floor plan. The schematic diagrams shown in Fig. 1(a) to (d) may differ from the actual size ratio. In Figure 1(a)-(d), a pair of metal substrates 12, 14 in Embodiment 1 are made of iron, aluminum or copper, or their alloys, and are plated with gold and/or silver as needed to form packaging electrodes. . The package is constituted by the reflector 16 and the aforementioned pair of package electrodes.

The reflector 16 is made of, for example, alumina-based, alumina-glass composite-based ceramics, or the like. In addition, the above-mentioned reflector 16 is bonded to a metal substrate, a ceramic substrate, or the like with an adhesive of silicone resin, epoxy resin, polyimide resin, glass, or solder.

In addition, the pair of metal substrates 12 and 14 are insulated from each other by the gap or the insulating member 13 . The reflector 16 has reflective surfaces 161 and 162 , and the GaN-based upper and lower electrode type light-emitting diodes 11 and metal members 15 are mounted on the metal substrates 12 and 14 inside. In addition, a phosphor layer mounting frame 19 for mounting a phosphor layer 191 and the like is fitted into the above-mentioned reflector 16 . The phosphor layer mounting frame 19 is mounted with the phosphor layer 191 and transparent silicone resin films 192 and 193 sandwiching the phosphor layer 191 from up and down. In addition, since the gallium nitride-based upper and lower electrode type light-emitting diodes 11 and the metal member 15 are not filled with a sealing material, a space 18 is formed between them and the phosphor layer 191 .

The aforementioned metal substrates 12 and 14 are, for example, a square of 10mm×10mm, and the gap 13 between them has a width of 0.5mm. In addition, the gallium nitride-based upper and lower electrode type light-emitting diodes 11 have a size of 1.0 mm×1.0 mm and a thickness of 0.5 mm.

In the GaN-based upper and lower electrode type light emitting diode 11, the lower electrode 112 (see FIG. 1(c)) is bonded to the metal substrate 12 with solder or the like. The upper electrode 111 (see FIG. 1( c )) of the gallium nitride-based upper and lower electrode type light emitting diode 11 is bonded to the metal substrate 14 via the metal member 15 by the same solder as above. The above-mentioned bonding by solder is simultaneously performed by passing through a reflow furnace. In addition, the above-mentioned gallium nitride-based upper and lower electrode type light-emitting diodes have fine unevenness formed on the surface of the upper electrode, so that light can be irradiated efficiently.

In FIG. 1( b ), the phosphor layer mounting frame 19 consists of an annular frame portion 19 - 1 and a substantially horizontal phosphor layer mounting portion 19 - 2 provided continuously below the annular frame portion 19 - 1 . , a reflector internal fitting convex part 19-3 provided continuously with the above-mentioned phosphor layer mounting part 19-2 and fitted into the internal concave part of the reflector 16, and the reflector internal fitting convex part 19-3 The reflection body mounting part 19-4 which is connected and becomes the back side of the said phosphor layer mounting part 19-2 is comprised. The phosphor layer mounting portion 19 - 2 can be provided with transparent silicone resin films 192 and 193 to protect the upper and lower surfaces of the phosphor layer 191 as needed.

The above-mentioned phosphor layer mounting frame 19 can be produced at any place, fitted to the above-mentioned reflector 16, and fixed with an adhesive or the like. The above-mentioned space portion 18 is connected to the outside atmosphere through a hole or a cutout portion, etc., not shown, provided in the above-mentioned phosphor layer mounting frame 19 as necessary. Since the hole or notch can keep the pressure of the space 18 constant, no cracks, cracks, or curls will occur on the phosphor layer 191 or the like. In addition, by adding a desired substance to the above-mentioned phosphor layer 191 , light of a desired color can be irradiated from the gallium nitride-based upper and lower electrode type light emitting diodes 11 .

In addition, by mixing the above-mentioned phosphor layer 191 into the above-mentioned transparent silicone resin films 192 and 193, the color of light emitted from the gallium nitride-based upper and lower electrode type light-emitting diodes 11 can be converted into a desired color. In addition, if the phosphor layer mounting frame 19 has a plurality of phosphor layers 191 having different phosphors, it is possible to immediately respond to a request for light of a desired color.

(Example 2)

2(a) to (c) are Embodiment 2 of the present invention, and FIG. 2(a) is a cross-sectional view illustrating a state in which gallium nitride-based upper and lower electrode type light-emitting diodes are mounted on a pair of metal substrates. FIG. 2( b ) is a cross-sectional view of a phosphor layer mounting frame, and FIG. 2( c ) is a perspective view of a metal member. In Fig. 2 (a) ~ (c), the difference from Embodiment 1 is that at least two packaging electrodes 14-1, 14-2 insulated from each other are formed on the ceramic substrate 12', and the phosphor layer The mounting frame 21 is fitted on the outside of the reflector 16 .

The phosphor layer mounting frame 21 is composed of an annular frame portion 211, a substantially horizontal phosphor layer mounting portion 212 provided continuously under the annular frame portion 211, and a phosphor layer mounting portion 212 continuously disposed. The mounting portion 214 placed on the reflector 16 and the fitting portion 213 fitted to the outside of the reflector 16 are configured. Transparent silicone resin films 192 and 193 are attached to the phosphor layer mounting portion 212 to protect the upper and lower surfaces of the phosphor layer 191 . The inside of the reflector 16 in FIGS. 1 and 2 is circular, and the surrounding is square, but not limited to a square cylindrical shape, and also includes circular, elliptical, square, rectangular, and other deformed shapes. The above-mentioned phosphor layer can also be provided directly on the above-mentioned reflector 16 without passing through a frame.

The metal member 15 shown in FIG. 2( c ) is used to connect the upper electrode of the gallium nitride-based upper and lower electrode type light-emitting diodes and another package electrode. The metal member 15 is composed of a joint portion 155 joined to the package electrode, two arm portions 151, 153, and an end portion 154 joined to the upper electrode of the gallium nitride-based upper and lower electrode type light emitting diode. The bonding portion 155 and the package electrode are firmly bonded with solder over a large area. The above-mentioned metal parts 15 are plated with gold and/or silver on copper, aluminum or their alloys to improve light reflection and solder wettability. In addition, the shape of the above-mentioned metal member 15 is such that the light emitted from the side of the light-emitting layer of the gallium nitride-based upper and lower electrode type light-emitting diode passes through the upper part, in addition to that shown in FIG. 2(c). Furthermore, the above-mentioned metal member 15 is constituted by a long strip of metal wire whose shape can be changed, and has a large joining area by soldering, so that it is easy to mount.

The above-mentioned metal wire strip has a thickness of 25 μm and a width of 150 μm, and can be increased or decreased around the above-mentioned length. Since the above-mentioned metal wire strip is made of elongated metal, heat conduction is good and a large current can flow. In addition, since the above-mentioned metal wire tape reflects light well, it can emit light efficiently to the outside without forming a shadow.

(Example 3)

3( a ) is a cross-sectional view of a light-emitting device made of a metal substrate and ceramics with packaging electrodes according to Embodiment 3 of the present invention, FIG. 3( b ) is an enlarged cross-sectional view, and FIG. 3( c) is a plan view. In FIGS. 3( a ) to ( c ), in the package, the metal substrate 12 and the ceramic substrate 12 ′ having package electrodes 121 are bonded together with an adhesive or the like via a reflector 16 . The above-mentioned metal substrate 12 and the lower electrode 112 of the GaN-based upper and lower electrode type light emitting diode 11 (Fig. The metal member 15 and the package electrode 121 of the ceramic substrate 12' are bonded with solder.

The above-mentioned junction can be plated with gold and/or silver in advance to improve the wettability of the solder. The metal substrate 12 and the ceramic substrate 12' are plated with gold and/or silver on the entire surface to simultaneously achieve improvement in current conductivity, light reflectivity, and wettability of joints. The package electrode 121 is connected to the lower electrode 122 (for the ceramic substrate) through the via hole 33 plated with gold and/or silver. The above-mentioned lower electrode 122 and the metal substrate 12 are soldered to wiring on a printed wiring board (not shown).

The gallium nitride-based upper and lower electrode type light emitting diode 11 has an active layer between, for example, a p-type gallium nitride semiconductor layer and an n-type gallium nitride semiconductor layer. The gallium nitride-based upper and lower electrode type light emitting diode has an upper surface light-emitting portion and a partial electrode on the upper portion of the one semiconductor layer, and has a lower electrode connected to the encapsulation electrode on the lowermost layer of the other semiconductor layer.

4( a ) and FIG. 4( b ) are enlarged plan views of the upper surfaces of the electrodes in the gallium nitride-based upper and lower electrode type light-emitting diodes of the present invention. In FIGS. 4( a ) and ( b ), the above-mentioned gallium nitride-based upper and lower electrode type light-emitting diodes 11 have fine unevenness formed on the light-emitting portion on the upper part, and high luminance can be obtained by flowing a large current.

(comparative example)

A comparison was made between a GaN-based upper and lower electrode type light emitting diode in which metal wires were ultrasonically connected in a conventional example and a GaN based upper and lower electrode type light emitting diode of the present invention joined by solder and metal members. In the conventional example, two metal wires with a diameter of 30 μm were used to connect the upper electrode of the gallium nitride-based upper and lower electrode type light-emitting diodes to the other wire bonding of the metal substrate by ultrasonic wire bonding. , About 10% of defective products with poor luminescence were produced. Furthermore, when energizing at 350 mA, about 4% of burning loss due to abnormal energization occurred. In the examples of the present invention, no defective product occurred in either the connection step or the energization of 350 mA to 500 mA.

FIG. 5 is a comparative example for explaining an example in which the luminosity of a gallium nitride-based upper and lower electrode type light-emitting diode (blue) was measured depending on the presence or absence of a sealing material. In this example, a GaN-based upper and lower electrode type light-emitting diode with a wavelength of 450nm and a blue light-emitting diode with a concave-convex surface and a wavelength of 450nm was bonded to the package, and a current of 3.2V and 350mA was passed to measure the luminosity of the blue light, which was 5000mcd. ~5700mcd. When this is used as a sealing material and sealed with a silicone-based elastomer type and a gel type sealing material, the luminosity decreases by about 600mcd to 900mcd (comparative example).

In addition, a phosphor film obtained by blending a europium-based yellow phosphor (manufactured by Intermatix Corporation, Y4254, 28% by weight, 250 μm in thickness) in a silicone resin was bonded to the steps on the upper part of the reflector, and the blue and fluorescent light of the light-emitting diode were used. The yellow emitted by the body emits white light, and the luminosity of the white light was measured by flowing a current of 3.2V and 350mA in the same manner as above, and the luminosity of the white light was 25800mcd to 26900mcd in the examples, and 21600mcd to 23600mcd in the comparative examples. Measured light beam simultaneously, embodiment is 67.6 lumens～74.2 lumens, average 70.5 lumens; The comparative example that has used elastomer type sealing material is 57.4 lumens～64.0 lumens, average 60 lumens; The comparative example that has used gel type sealing material is 60.2 Lumens ~ 63.1 lumens, with an average of 61.5 lumens. The luminous flux of the white light of the embodiment is increased by 14.6% to 17.5% compared with the comparative example. In addition, an LHD tester manufactured by Fuxing System Co., Ltd. of Japan was used for photometric measurement, and a beam meter manufactured by LAB SPHERE Company was used for beam measurement.

Industrial availability

As mentioned above, although the Example of this invention was demonstrated in detail, this invention is not limited to the said Example. In addition, in the present invention, various design changes can be made without departing from the scope described in the claims. This embodiment describes a pair of insulated metal substrates or package electrodes, but it goes without saying that a plurality of GaN-based upper and lower electrode type light-emitting diodes and package electrodes can be connected in series and/or in parallel. light emitting device.

The gallium nitride-based upper and lower electrode type light-emitting diodes of the present invention are joined by solder for connecting upper and lower electrodes, metal substrates, metal parts, and the like. Solder is especially preferred. As the solder, known or well-known materials such as solder paste, solder and flux, gold-tin eutectic solder paste, and indium-based eutectic solder can be used. The above solders include, for example, gold and tin (20%), gold and tin (90%), gold and silicon dioxide (3.15%), gold and germanium (12%), and tin-copper-nickel systems, Tin-silver, tin-silver-copper, tin-silver-bismuth-indium, tin-zinc eutectic solder. For the gallium nitride-based upper and lower electrode type light-emitting diodes of the present invention, known or well-known ones can be used in the same manner as above. As the phosphor layer and gallium nitride-based upper and lower electrode type light-emitting diodes used in the present invention, known or well-known ones can be used.

Claims (9)

1. A light emitting device, characterized in that it is at least composed of the following components: a package having a reflector and at least one pair of package electrodes on the bottom of said reflector; Gallium nitride-based upper and lower electrode type light-emitting diodes, which have an active layer between the p-type gallium nitride semiconductor layer and the n-type gallium nitride semiconductor layer, and have an upper surface light-emitting part and some electrodes on the upper part of the above-mentioned one semiconductor layer. The lowermost layer of the another semiconductor layer has a lower electrode joined to one of the encapsulation electrodes; A metal part that connects the upper part of the electrode of the above-mentioned gallium nitride-based upper and lower electrode type light-emitting diodes to the other of the above-mentioned packaging electrodes; Solder used for joining one of the package electrodes to the lower electrode, joining the partial upper electrode to the metal member, or joining the metal member to the other of the package electrodes; and a phosphor layer mounted near the upper surface of the reflector, and The upper surface of the gallium nitride-based upper and lower electrode type light emitting diodes has fine unevenness formed on the upper surface of the light emitting part, and there is no sealing material on the upper surface. 2. The lighting device according to claim 1, characterized in that: The above-mentioned package is composed of a pair of separated metal substrates as package electrodes, and a reflector bonded to the pair of metal substrates. 3. The lighting device according to claim 1, characterized in that: The package is composed of a ceramic substrate on which at least one pair of package electrodes is formed, and a reflector bonded to the ceramic substrate. 4. The lighting device according to claim 1, characterized in that: The package includes a metal substrate as one of at least one pair of package electrodes, a ceramic substrate on which the other of the package electrodes is formed, and a reflector joined to the metal substrate and the ceramic substrate. 5. The light-emitting device according to any one of claims 1-4, characterized in that: The metal member is a gold or silver ribbon wire, or an aluminum or copper ribbon wire covered with gold and/or silver. 6. The light-emitting device according to any one of claims 1-5, characterized in that: The above-mentioned reflector is composed of alumina-based, alumina-glass composite-based ceramics, etc., using silicone resin-based, epoxy resin-based, polyimide resin-based, glass-based, and solder-based adhesives bonded to the above substrate. 7. The light-emitting device according to any one of claims 1-6, characterized in that: The phosphor layer is bonded to a step provided above the reflector. 8. The light-emitting device according to any one of claims 1-7, characterized in that: The phosphor layer is provided on a frame attached to the opening of the reflector. 9. The light-emitting device according to any one of claims 1-8, characterized in that: A plurality of the gallium nitride-based upper and lower electrode type light emitting diodes and package electrodes connecting the plurality of gallium nitride based upper and lower electrode type light emitting diodes in series and/or in parallel are provided on the bottom of the reflector.

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