JP2009130298A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device capable of decreasing the amount of a light diffusing material and suppressing local heat generation of a color converting member. <P>SOLUTION: The light emitting device includes an LED chip 10, a mounting substrate 20 on which the LED chip 10 is mounted, and the dome-shaped color converting member 70 which is formed by dispersing fluorescent particles excited with light emitted by the LED chip 10 to emit visible light with a longer wavelength than that of the LED chip in a base material made of a transparent material (silicone resin etc.) and disposed enclosing the LED chip 10 between the mounting substrate 20. The color converting member 70 is configured such that the light diffusing material 73 differing in refractive index from the base material is dispersed only in a predetermined area whose relative incident light intensity based upon orientation characteristics of the LED chip 10 exceeds a specified value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light emitting device using an LED chip (light emitting diode chip).

  Conventionally, a GaN LED chip that emits blue light or ultraviolet light, and a phosphor or light absorption as a wavelength conversion material that emits light of an emission color different from that of the LED chip when excited by light emitted from the LED chip. Research and development of light emitting devices that emit light of a color different from the emission color of the LED chip, including white, by combining with the body is performed in various places (for example, see Patent Document 1), and the light output of the light emitting device is increased. Along with this, application to lighting applications is progressing.

Here, in Patent Document 1, as shown in FIG. 9, the LED chip 10 ′, the mounting substrate 20 ′ on which the LED chip 10 ′ is mounted on one surface side, and the light emitted from the LED chip 10 ′. The dome is formed by phosphor particles that emit visible light having a wavelength longer than that of the LED chip 10 ′ and a light-transmitting material, and is disposed between the mounting substrate 20 ′ and the LED chip 10 ′. And a light-emitting device 1 ′ in which a light diffusing material is dispersed in the color conversion member 70 ′. In the light emitting device 1 ′ having the configuration shown in FIG. 9, a GaN blue LED chip is used as the LED chip 10 ′, and a yellow phosphor is used as the phosphor of the color conversion member 70 ′, thereby obtaining white light. be able to.
JP 2007-250817 A

  By the way, in the above-described light emitting device 1 ′, the color unevenness can be reduced, but since the light diffusing material is dispersed throughout the color conversion member 70 ′, the amount of the light diffusing material is relatively large. In addition, the cost increases, and the distribution of the phosphor particles that generate heat due to the energy loss due to the Stokes shift is likely to be locally concentrated due to the light distribution of the LED chip 10 ′, and the color conversion member 70 ′. The temperature rises locally, which tends to cause a decrease in the light conversion efficiency of the phosphor particles and a decrease in the reliability of the color conversion member 70 ′.

  The present invention has been made in view of the above reasons, and an object of the present invention is to provide a light emitting device capable of reducing the amount of the light diffusing material and suppressing local heat generation of the color conversion member. is there.

  According to the first aspect of the present invention, an LED chip, a mounting substrate on which the LED chip is mounted, and phosphor particles that are excited by light emitted from the LED chip and emit visible light having a longer wavelength than the LED chip are transmitted. A dome-shaped color conversion member that is dispersed in a base material made of a light-sensitive material and is disposed so as to surround the LED chip between the mounting substrate and the color conversion member. The different light diffusing materials are dispersed only in a prescribed region where the relative incident light intensity based on the orientation characteristics of the LED chip exceeds a prescribed value.

  According to this invention, since the color conversion member has the light diffusion material having a refractive index different from that of the base material dispersed in only the specified region where the relative incident light intensity based on the orientation characteristics of the LED chip exceeds the specified value, Compared with the case where the light diffusing material is dispersed over the entire color conversion member, the amount of the light diffusing material can be reduced, and in the specified region where the relative incident light intensity exceeds the specified value in the color converting member, Light from the LED chip can be diffused, and the phosphor particles that generate heat due to energy loss due to Stokes shift can be prevented from being concentrated locally, so that the amount of light diffusing material can be reduced and It becomes possible to suppress local heat generation of the color conversion member.

  The invention of claim 2 is characterized in that the base material is glass as compared with the invention of claim 1.

  According to this invention, the temperature increase of the color conversion member can be suppressed as compared with the case where the base material is an organic material such as a silicone resin.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the light diffusing material is made of glass fiber.

  According to this invention, compared with the case where the light diffusing material is spherical, it is possible to efficiently dissipate heat generated in the phosphor particles of the color conversion member, and the color conversion member can be locally dissipated. It is possible to further suppress excessive heat generation.

  According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the light diffusing material comprises metal nanoparticles.

  According to the present invention, the surface plasmon polariton is excited in the light diffusing material by the light from the LED chip and the light from the LED chip is enhanced, so that it is possible to increase the light extraction efficiency to the outside. .

  According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the mounting substrate is formed of a heat conductive material.

  According to this invention, it is possible to efficiently dissipate the heat generated in the color conversion member through the mounting substrate, and it is possible to further suppress local heat generation of the color conversion member.

  According to a sixth aspect of the present invention, in any of the first to fifth aspects of the present invention, a dome-shaped optical member disposed so as to surround the LED chip between the mounting substrate and the color conversion member. A sealing portion in which the LED chip is sealed inside the optical member, and an air layer is formed between the color conversion member and the optical member.

  According to this invention, among the light emitted from the LED chip and scattered by the phosphor particles in the color conversion member, the amount of light scattered to the optical member side and transmitted through the optical member can be reduced, and the entire apparatus The light output can be improved by improving the light extraction efficiency to the outside.

  According to the first aspect of the present invention, the amount of the light diffusing material can be reduced and local heat generation of the color conversion member can be suppressed.

(Embodiment 1)
Hereinafter, the light-emitting device of this embodiment will be described with reference to FIGS.

  The light emitting device 1 of the present embodiment has a rectangular plate shape in which the LED chip 10 has conductor patterns 23 and 23 for supplying power to the LED chip 10 on one surface side, and the LED chip 10 is mounted on the one surface side. An optical member that controls the light distribution of the light emitted from the mounting substrate 20 and the LED chip 10 and is fixed to the one surface side of the mounting substrate 20 in such a manner that the LED chip 10 is housed between the mounting substrate 20 and the mounting substrate 20. A plurality of dome-shaped optical members 60 made of a translucent material, and a plurality of LED chips 10 that are electrically connected to the LED chips 10 in a space surrounded by the optical members 60 and the mounting substrate 20 (books). In the embodiment, the sealing portion 50 made of a light-transmitting sealing resin sealing the two bonding wires 14 and the light emitted from the LED chip 10 and transmitted through the sealing portion 50 and the optical member 60 are used. The phosphor particles that are excited and emit visible light having a wavelength longer than that of the LED chip 10 are dispersed in a base material made of a light-transmitting material, and the LED is placed between the mounting substrate 20 on the one surface side of the mounting substrate 20. And a dome-shaped color conversion member 70 disposed so as to surround the chip 10 and the like. Here, the color conversion member 70 is disposed so that an air layer 80 is formed between the light emitting surface 60 b of the optical member 60 on the one surface side of the mounting substrate 20. Further, the mounting substrate 20 has an annular dam portion 27 protruding outside the optical member 60 on the one surface so as to dam the sealing resin overflowing from the space when the optical member 60 is fixed to the mounting substrate 20. Has been.

  Here, when using the light-emitting device 1 of this embodiment as a light source of a lighting fixture, for example, the fixture main body 100 (FIG. 2) made of metal (for example, a metal having high thermal conductivity such as Al or Cu) in the lighting fixture. 5 and 6) and the mounting substrate 20, a resin sheet containing a filler made of a filler such as silica or alumina and having a low viscosity when heated (for example, an epoxy resin sheet highly filled with fused silica) What is necessary is just to join by the joining member 90 which consists of such an organic green sheet. Here, since the joining member 90 made of the resin sheet has electrical insulation properties, has high thermal conductivity, high fluidity during heating, and high adhesion to the uneven surface, the mounting substrate 20 is made of a metal instrument. Joining to the main body 100 via the joining member 90 (the joining member 90 is heated between the mounting substrate 20 and the instrument main body 100 and then the joining member 90 is heated to thereby heat the mounting substrate 20 and the instrument main body 100. Can be prevented from generating gaps between the bonding member 90 and the mounting substrate 20 and the instrument main body 100, thereby preventing an increase in thermal resistance and variations due to insufficient adhesion. Compared to the conventional case where the light emitting device is mounted on a circuit board and a rubber sheet-like heat radiation sheet such as Sarcon (registered trademark) is sandwiched between the circuit board and the instrument body, the LED chip 10 Since the heat resistance up to the instrument body 100 can be reduced, the heat dissipation is improved, the variation in the heat resistance is reduced, and the temperature rise of the junction temperature of the LED chip 10 can be suppressed, so that the input power can be increased, High output can be achieved. In addition, when using the light-emitting device 1 of this embodiment as a light source of a lighting fixture, as shown in FIG. 5, the several light-emitting device 1 is mounted in the fixture main body 100, and the several light-emitting device 1 is connected in series. Or connect in parallel. In addition, the light emitting device 1 is not limited to the metal instrument body 100 but may be bonded to the metal member via the bonding member 90.

  The LED chip 10 is a GaN-based blue LED chip that emits blue light, and uses an n-type SiC substrate having a lattice constant and a crystal structure close to GaN as compared to a sapphire substrate and having conductivity as a crystal growth substrate. In addition, a light emitting part formed of a GaN-based compound semiconductor material and having a laminated structure part having a double hetero structure, for example, is grown on the main surface side of the SiC substrate by an epitaxial growth method (for example, MOVPE method). Here, the LED chip 10 has an anode electrode (not shown) formed on one surface side (upper surface side in FIG. 1A) and a cathode electrode on the other surface side (lower surface side in FIG. 1A). Is formed. The cathode electrode and the anode electrode are composed of a laminated film of a Ni film and an Au film, but the material of the cathode electrode and the anode electrode is not particularly limited, and a material capable of obtaining good ohmic characteristics For example, Al or the like may be employed. Further, the structure of the LED chip 10 is not particularly limited. For example, a light emitting unit is formed by supporting a light emitting unit after epitaxially growing the light emitting unit or the like on the main surface side of the crystal growth substrate. Alternatively, a substrate obtained by removing the crystal growth substrate or the like may be used.

  The mounting substrate 20 is made of a thermally conductive material and has a rectangular plate-shaped heat transfer plate 21 on which the LED chip 10 is mounted, and one surface side of the heat transfer plate 21 (upper surface side in FIG. 1A), for example, polyolefin-based. And a wiring board 22 made of a rectangular flexible printed wiring board fixed via a fixing sheet 29 (see FIG. 2). The mounting surface of the LED chip 10 on the heat transfer plate 21 at the center of the wiring board 22 A rectangular window hole 24 for exposing (a part of the one surface) is formed, and the LED chip 10 is mounted on the heat transfer plate 21 via a submount member 30 described later disposed inside the window hole 24. Has been. Therefore, the heat generated in the LED chip 10 is transferred to the submount member 30 and the heat transfer plate 21 without passing through the wiring board 22. Here, an alignment mark 21c (see FIG. 2) for increasing the positioning accuracy of the submount member 30 is formed on the one surface of the heat transfer plate 21.

  In this embodiment, Cu is adopted as the heat conductive material of the heat transfer plate 21, but not limited to Cu, for example, Al may be adopted. In the present embodiment, the LED chip 10 is mounted on the heat transfer plate 21 so that the light emitting portion of the LED chip 10 is farther from the heat transfer plate 21 than the crystal growth substrate. The heat transfer plate 21 may be mounted so as to be closer to the heat transfer plate 21 than the crystal growth substrate. In consideration of light extraction efficiency, it is desirable to arrange the light emitting part on the side away from the heat transfer plate 21, but in this embodiment, the crystal growth substrate and the light emitting part have the same refractive index. Therefore, even if the light emitting part is arranged on the side close to the heat transfer plate 21, the light extraction loss does not become too large.

  The above-mentioned wiring board 22 is provided with a pair of conductor patterns 23 and 23 for supplying power to the LED chip 10 on one surface side of an insulating base material 22a made of a polyimide film. A protective layer 26 made of a white resist (resin) covering a portion of the conductive base material 22a where the conductor patterns 23, 23 are not formed is laminated. Therefore, the light emitted from the side surface of the LED chip 10 and incident on the surface of the protective layer 26 is reflected by the surface of the protective layer 26, thereby preventing the light emitted from the LED chip 10 from being absorbed by the wiring substrate 22. Thus, the light output can be improved by improving the light extraction efficiency to the outside. In addition, each conductor pattern 23 and 23 is formed in the outer periphery shape a little smaller than half of the outer periphery shape of the insulating base material 22a. Further, FR4, FR5, paper phenol or the like may be employed as the material of the insulating base material 22a.

  The protective layer 26 is patterned so that two portions of the conductor patterns 23 and 23 are exposed in the vicinity of the window hole 24 of the wiring substrate 22 and one portion of the conductor patterns 23 and 23 is exposed in the peripheral portion of the wiring substrate 22. In each conductor pattern 23, 23, two rectangular portions exposed in the vicinity of the window hole 24 of the wiring substrate 22 constitute a terminal portion 23 a to which the bonding wire 14 is connected. The circular part exposed in the part constitutes the external connection electrode part 23b. The conductor patterns 23 and 23 of the wiring board 22 are constituted by a laminated film of a Cu film, a Ni film, and an Au film. In addition, “+” is used for the external connection electrode portion 23b (the right external connection electrode portion 23b in FIG. 6) to which the anode electrode of the LED chip 10 is electrically connected, of the two external connection electrode portions 23b. Is displayed, and “−” is formed on the external connection electrode portion 23b (the left external connection electrode portion 23b in FIG. 6) to which the cathode electrode of the LED chip 10 is electrically connected. Therefore, the polarities of the external connection electrode portions 23b and 23b in the light emitting device 1 can be visually recognized, and erroneous connection can be prevented.

  By the way, the LED chip 10 is mounted on the heat transfer plate 21 via the above-described submount member 30 that relieves stress acting on the LED chip 10 due to a difference in linear expansion coefficient between the LED chip 10 and the heat transfer plate 21. Has been. Here, the submount member 30 is formed in a rectangular plate shape having a size larger than the chip size of the LED chip 10.

  The submount member 30 has not only a function of relieving the stress but also a heat conduction function of transferring heat generated in the LED chip 10 to a range wider than the chip size of the LED chip 10 in the heat transfer plate 21. Yes. Therefore, in the light emitting device 1 of the present embodiment, since the LED chip 10 is mounted on the heat transfer plate 21 via the submount member 30, the heat generated in the LED chip 10 is transferred to the submount member 30 and the heat transfer plate 21. The heat acting on the LED chip 10 due to the difference in linear expansion coefficient between the LED chip 10 and the heat transfer plate 21 can be relieved.

  In the present embodiment, AlN having a relatively high thermal conductivity and insulation is used as the material of the submount member 30, and the LED chip 10 has the cathode electrode on the LED chip 10 side of the submount member 30. An electrode pattern 31 (see FIG. 2) provided on the surface and connected to the cathode electrode and electrically connected to one conductor pattern 23 via a bonding wire 14 made of a fine metal wire (for example, a gold fine wire, an aluminum fine wire, etc.) The anode electrode is electrically connected to the other conductor pattern 23 via the bonding wire 14. The LED chip 10 and the submount member 30 may be bonded using, for example, solder such as SnPb, AuSn, SnAgCu, or silver paste, but may be bonded using lead-free solder such as AuSn, SnAgCu. Preferably, when the submount member 30 is made of Cu and bonded using AuSn, a pretreatment is required in which a metal layer made of Au or Ag is formed in advance on the bonding surface of the submount member 30 and the LED chip. It is. Further, the submount member 30 and the heat transfer plate 21 are preferably bonded using, for example, lead-free solder such as AuSn or SnAgCu. However, when bonding using AuSn, the bonding in the heat transfer plate 21 is performed. A pretreatment for forming a metal layer made of Au or Ag in advance on the surface is necessary.

  The material of the submount member 30 is not limited to AlN, and may be any material that has a linear expansion coefficient that is relatively close to 6H—SiC that is a material for a crystal growth substrate and that has a relatively high thermal conductivity. Si, Cu, CuW or the like may be employed. The submount member 30 has the above-described heat conduction function, and the area of the surface of the heat transfer plate 21 on the LED chip 10 side is sufficiently larger than the area of the surface of the LED chip 10 on the heat transfer plate 21 side. Larger is desirable.

  In the light emitting device 1 of the present embodiment, the thickness dimension of the submount member 30 is set so that the surface of the submount member 30 is farther from the heat transfer plate 21 than the surface of the protective layer 26 of the wiring board 22. In addition, light emitted from the LED chip 10 to the side can be prevented from being absorbed by the wiring board 22 through the inner peripheral surface of the window hole 24 of the wiring board 22. In addition, if a reflective film that reflects the light emitted from the LED chip 10 is formed around the bonding portion with the LED chip 10 on the surface of the submount member 30 on the side to which the LED chip 10 is bonded, the LED chip 10 is formed. It is possible to prevent the light radiated from the side surface from being absorbed by the submount member 30 and to further increase the light extraction efficiency to the outside. Here, the reflective film may be constituted by a laminated film of a Ni film and an Al film, for example.

  As the sealing resin that is the material of the sealing portion 50 described above, a silicone resin is used. However, the sealing resin is not limited to the silicone resin, and for example, an acrylic resin may be used. Further, glass may be used instead of the sealing resin.

  The optical member 60 is a molded product of a translucent material (for example, silicone resin, glass, etc.) and is formed in a dome shape. Here, in this embodiment, since the optical member 60 is formed of a silicone resin molded product, the difference in refractive index and the linear expansion coefficient between the optical member 60 and the sealing portion 50 can be reduced. In addition, when the material of the sealing part 50 is an acrylic resin, it is preferable to form the optical member 60 also with an acrylic resin.

  By the way, the optical member 60 has a light emitting surface 60b formed in a convex curved surface shape that does not totally reflect the light incident from the light incident surface 60a at the boundary between the light emitting surface 60b and the air layer 80 described above. 10 and the optical axis coincide with each other. Therefore, the light emitted from the LED chip 10 and incident on the light incident surface 60a of the optical member 60 can easily reach the color conversion member 70 without being totally reflected at the boundary between the light emitting surface 60b and the air layer 80, The total luminous flux can be increased. The light emitted from the side surface of the LED chip 10 propagates through the sealing portion 50, the optical member 60, and the air layer 80 to reach the color conversion member 70 and excites the phosphor particles of the color conversion member 70, or the phosphor. The particles pass through the color conversion member 70 without colliding with the particles. Further, the optical member 60 is formed so that the thickness is uniform along the normal direction regardless of the position.

  The color conversion member 70 is a molded product of a mixture in which a translucent material such as a silicone resin and phosphor particles that are excited by blue light emitted from the LED chip 10 and emit broad yellow light are mixed. (The color conversion member 70 has phosphor particles dispersed in a base material made of a translucent material.) Therefore, in the light emitting device 1 of this embodiment, the blue light emitted from the LED chip 10 and the light emitted from the phosphor particles are emitted through the light emitting surface 70b of the color conversion member 70, and white light is emitted. Obtainable. The translucent material used as the material of the color conversion member 70 is not limited to a silicone resin, but an organic / inorganic hybrid in which, for example, an acrylic resin, glass, an organic component and an inorganic component are mixed and combined at the nm level or the molecular level. Materials etc. may be adopted. Further, the phosphor particles mixed with the translucent material used as the material of the color conversion member 70 are not limited to the yellow phosphor particles. For example, white light is obtained even when the red phosphor particles and the green phosphor particles are mixed. be able to.

  Here, the color conversion member 70 has a light incident surface 70 a formed along the light emitting surface 60 b of the optical member 60. Accordingly, the distance between the light emitting surface 60b in the normal direction and the light incident surface 70a of the color conversion member 70 is a substantially constant value regardless of the position of the light emitting surface 60b of the optical member 60. In addition, the color conversion member 70 is shape | molded so that the thickness along a normal line direction may become uniform irrespective of a position. Further, the color conversion member 70 is fixed to the mounting substrate 20 with an end edge (periphery of the opening) on the mounting substrate 20 side using, for example, an adhesive (for example, silicone resin, epoxy resin, low melting point glass, or the like). do it.

  In the above-described lighting fixture using the light-emitting device 1 of the present embodiment as a light source, the wiring pattern 202 that defines the connection relationship of each light-emitting device 1 has one surface of the insulating substrate 201 as shown in FIGS. A circuit board 200 formed on the side is provided. In the present embodiment, the plurality of light emitting devices 1 are connected in series. However, the connection relationship between the plurality of light emitting devices 1 is not particularly limited. For example, the light emitting devices 1 may be connected in parallel or connected in series. And parallel connection may be combined.

  The circuit board 200 is disposed in the shallow bottomed cylindrical instrument body 100 so as to be separated from the bottom wall 100a of the instrument body 100, and the circuit board 200 is disposed at a position corresponding to each light-emitting device 1 respectively. An aperture window 204 through which a part passes is formed. In addition, as a material of the insulating base material 201 of the circuit board 200, for example, a glass epoxy resin such as FR4 may be adopted, but not limited to a glass epoxy resin, for example, a polyimide resin, a phenol resin, or the like may be used. . Moreover, the shape of the instrument main body 100 is not specifically limited, For example, flat form may be sufficient.

  The circuit board 200 described above is provided with a wire insertion hole 206 through which a lead wire for power supply inserted through the insertion hole 100c formed in the bottom wall 100a of the instrument body 100 is inserted. A pair of electric wires inserted through 206 is electrically connected. Further, the circuit board 200 has a light reflecting layer 203 made of a white resist layer formed on the surface side opposite to the bottom wall 100 a side of the instrument body 100, and most of the wiring pattern 202 is the light reflecting layer 203. Covered by.

  In the circuit board 200, the opening size of each opening window 204 is set to be slightly larger than the planar size of the mounting substrate 20 in the light emitting device 1. In addition, in order to prevent an overvoltage from being applied to the LED chip 10 of the light emitting device 1, a surface mount type Zener diode 231 (see FIG. 6) for preventing overvoltage and a surface mount type ceramic are provided on the circuit board 200. A capacitor 232 (see FIG. 6) is mounted in the vicinity of each opening window 204.

  On the other hand, in the light emitting device 1, each external connection electrode portion 23 b of the mounting board 20 is electrically connected to the wiring pattern 202 of the circuit board 200 via the terminal board 210. Here, the terminal plate 210 forms a terminal piece 211 that is joined to the wiring pattern 202 by using solder or the like so as to overlap the wiring pattern 202 by bending one end of an elongated metal plate into an L shape. The other end portion is bent in a J shape to form a terminal piece 212 to be joined to the external connection electrode portion 23b using solder or the like so that the thickness direction thereof matches. It is possible to relieve the stress generated at the joint between the connection terminal 210, the external connection electrode portion 23b, and the wiring pattern 202 due to the difference in linear expansion coefficient with the circuit board 200. Connection reliability with the substrate 200 can be improved.

  Moreover, if the planar size of the above-mentioned sheet-like joining member 90 is set larger than the planar size of the heat transfer plate 21, the joining member 90 and the heat transfer plate 21 are formed in the same planar size. Compared to the case, the creeping distance between the heat transfer plate 21 and the tool body 100 that is a metal member can be increased, and the lightning surge resistance when used as a light source for a lighting fixture can be increased (however, In general, the creeping distance between the light emitting device and the metal member required for the indoor lighting fixture and the outdoor lighting fixture is different, and the outdoor lighting fixture requires a longer creepage distance). Here, the thickness of the sheet-like joining member 90 needs to be designed in accordance with the lightning surge resistance required withstand voltage, but it is desirable to set it thinner from the viewpoint of reducing thermal resistance. Therefore, regarding the joining member 90, after setting the thickness, the planar size may be set so that the creepage distance requirement can be satisfied.

  In the manufacturing method of the above-described light emitting device 1, for example, after the LED chip 10 and each of the conductor patterns 23 and 23 are electrically connected via the two bonding wires 14, the LED chip 10 is connected to the window hole 24 of the wiring board 22. After injecting liquid sealing resin (for example, silicone resin) that becomes a part of the sealing portion 50 into the gap between the submount member 30 and the wiring board 22 from the continuously formed injection hole 28, the resin is cured. Thereafter, liquid sealing resin (for example, silicone resin) which becomes the remaining portion of the sealing portion 50 described above is injected into the inside of the dome-shaped optical member 60, and then the optical member 60 is placed at a predetermined position on the mounting substrate 20. The optical member 60 is fixed to the mounting substrate 20 at the same time as the sealing portion 50 is formed by being disposed in the substrate and curing the sealing resin, and then the color conversion member 70 is fixed to the mounting substrate 20. Such a manufacturing method can be considered, but even in such a manufacturing method, bubbles may be generated in the sealing portion 50 during the manufacturing process, so a large amount of liquid sealing resin is injected into the optical member 60. There is a need to.

  Therefore, in the light emitting device 1 of the present embodiment, as described above, when the optical member 60 is fixed to the mounting substrate 20 outside the optical member 60 on the one surface of the mounting substrate 20, the space (with the optical member 60 and the optical member 60). An annular (in the present embodiment, annular) dam portion 27 is provided to dam up the sealing resin overflowing from the space surrounded by the mounting substrate 20. Here, the dam portion 27 is formed of a white resist. In addition, the dam portion 27 extends inward from the inner peripheral surface of the dam portion 27 to center the center of the dam portion 27 and the central axis of the optical member 60 (four in this embodiment). The claw portions 27b are spaced apart in the circumferential direction and provided at equal intervals, and also serve as a positioning portion for the color conversion member 70. Here, the number of the claw portions 27b for centering is not limited to four, but it is desirable to provide at least three, and the sealing resin that can be stored between the dam portion 27 and the optical member 60 In order to increase the permissible amount, it is desirable that the width dimension of the centering claw portion 27b is small.

  Further, the color conversion member 70 has a notch 71 that engages with the weir 27 on the edge of the mounting substrate 20 side over the entire circumference. Therefore, in the light emitting device 1 of the present embodiment, the positioning accuracy of the color conversion member 70 with respect to the mounting substrate 20 can be increased, and the interval between the color conversion member 70 and the optical member 60 can be shortened. The notch 71 is open on the edge side and the inner surface 70a side of the color conversion member 70.

  The portions of the conductive patterns 23 and 23 on the mounting substrate 20 that are exposed outside the color conversion member 70 constitute the external connection electrode portions 23b and 23b.

  In manufacturing the light emitting device 1 of the present embodiment, as shown in FIG. 4A, after the LED chip 10 is mounted on the mounting substrate 20 and the LED chip 10 and the bonding wires 14 and 14 are electrically connected. The liquid which becomes a part of the above-described sealing portion 50 in the gap between the submount member 30 and the wiring board 22 from the resin injection hole 28 (see FIG. 2) formed continuously to the window hole 24 of the wiring board 22. And a liquid sealing resin (for example, silicone resin) 50a that becomes a part of the above-described sealing portion 50 is injected inside the dome-shaped optical member 60. Then, the optical member 60 is made to face the mounting substrate 20, the optical member 60 and the mounting substrate 20 are brought closer as shown in FIG. 4B, and the optical member 60 is positioned as shown in FIG. 4C. Liquid sealing tree 50a to form a sealing portion 50 formed by curing the fixed optical member 60 to the mounting substrate 20, then, so that securing the color conversion member 70 to the mounting substrate 20. Here, in FIG. 4A, an appropriate amount (quantitative amount) of the sealing resin 50 a larger than the volume of the inner space of the optical member 60 is injected inside the dome-shaped optical member 60. In addition, the sealing resin 50a accumulated in the space surrounded by the optical member 60, the dam portion 27, and the protective layer 26 on the one surface side of the mounting substrate 20 is cured to be the resin portion 50b in FIG. It becomes.

  According to such a manufacturing method, it is difficult to generate voids in the sealing portion 50 during the manufacturing process, and it is possible to provide the light emitting device 1 with high reliability and high light output. Here, the sealing injected into the gap between the submount member 30 and the wiring board 22 before the optical member 60 is brought close to the mounting board 20 as shown in FIG. If the resin 50a is cured, there is an advantage that voids are easily removed when the optical member 60 and the mounting substrate 20 are brought close to each other as shown in FIG.

  In the light emitting device 1 of the present embodiment described above, the optical member 60 that controls the light distribution of the light emitted from the LED chip 10 is formed in a dome shape, and the LED chip 10 is accommodated between the mounting substrate 20. A sealing part that is fixed to the one surface side of the mounting substrate 20 and is made of a light-transmitting sealing resin that is filled in the space surrounded by the optical member 60 and the mounting substrate 20 and seals the LED chip 10. 50 and a dome-shaped color conversion member 70 disposed so as to surround the optical member 60 on the one surface side of the mounting substrate 20, and on the outer surface of the optical member 60 on the one surface of the mounting substrate 20. An annular dam portion 27 that dams up the sealing resin 50 a overflowing from the space when the member 60 is fixed to the mounting substrate 20 is projected, and the dam portion 27 extends inward from the inner peripheral surface of the dam portion 27. The center of the weir 27 and the optics A plurality of centering claws 27b for centering the central axis of the material 60 are provided apart from each other in the circumferential direction, and also serve as a positioning portion for the color conversion member 70. The conductor patterns 23 and 23 are formed of the color conversion member. Since the portions exposed outside 70 constitute the external connection electrode portions 23b and 23b, it is possible to prevent voids from being generated in the sealing portion 50, and the bonding wires 14 and 14 are disconnected and the light output is reduced. In addition, the positioning accuracy of the optical member 60 can be improved, and the optical member 60 and the inner peripheral surface of the dam portion 27 are separated from each other, so that the sealing resin 50a overflows outside the dam portion 27. Adhesion on the external connection electrode portions 23b and 23b can be suppressed, and the occurrence of poor soldering or the like in the external connection electrode portions 23b and 23b can be prevented. As shown in FIG. 7, the same material as the weir 27 (in this embodiment, between the annular weir 27 and each external connection electrode 23 b, 23 b on the one surface of the mounting substrate 20, If the arc-shaped resin stoppers 25, 25 formed of white resist are provided, it is possible to more reliably prevent the sealing resin 50a from adhering to the surfaces of the external connection electrode portions 23b, 23b during manufacturing. it can.

  Further, in the light emitting device 1 of the present embodiment, since the dam portion 27 is formed of a white resist, the light emitted from the LED chip 10 or the light emitted from the phosphor is absorbed by the dam portion 27. Can be prevented, and the optical output can be increased. In the light emitting device 1 of the present embodiment, the thickness dimension of the submount member 30 is such that the surface of the submount member 30 is farther from the heat transfer plate 21 than the one surface of the wiring board 22 (the surface of the protective layer 26). Therefore, the light emitted from the LED chip 10 to the side can be prevented from being absorbed by the wiring board 22 and the light output can be increased.

  Moreover, since the light-emitting device 1 of this embodiment has the conductor patterns 23 and 23 for the electric power feeding to the LED chip 10 in the said one surface side of the mounting board | substrate 20, mounting board | substrate 20 is mounted in a circuit board. Since it is possible to thermally couple with the fixture body 100 of the lighting fixture, the thermal resistance from the LED chip 10 to the fixture body 100 can be reduced, the heat dissipation is improved, and the temperature rise of the junction temperature of the LED chip 10 can be suppressed. The input power can be increased and the optical output can be increased.

  By the way, as shown in FIG. 1, the color conversion member 70 in the light emitting device 1 of the present embodiment is a spherical light diffusing material 73 having a refractive index different from that of a base material made of a translucent material (for example, silicone resin). The relative incident light intensity based on the orientation characteristics of the LED chip 10 (the orientation solid that is the envelope surface of the arrow tip of the radiated light vector in which the light intensity in each direction of the LED chip 10 is represented by the direction and length of the arrow) [Light intensity in a specific direction / maximum light intensity] × 100%) is dispersed only in a specified region exceeding a specified value. Here, the alignment characteristic of the LED chip 10 in this embodiment is a highly directional alignment characteristic in which the light intensity is maximized in the normal direction of the LED chip 10, and the relative incident light intensity at the top of the color conversion member 70 is Since it is larger than the peripheral portion of the color conversion member 70, the specified value is set to 90%, and the top of the color conversion member 70 is used as the specified region. However, the specified value is not limited to 90%, and may be set as appropriate within a range of about 50% to 90%.

  Accordingly, in the light emitting device 1 of the present embodiment, the color conversion member 70 is a stipulation that the relative incident light intensity based on the orientation characteristics of the LED chip 10 exceeds the stipulated value for the light diffusing material 73 having a refractive index different from that of the base material. Since the light diffusing material 73 is dispersed only in the region, the amount of the light diffusing material 73 can be reduced as compared with the case where the light diffusing material 73 is dispersed over the entire color converting member 70. In the specified region where the intensity exceeds the specified value, the light from the LED chip 10 can be diffused by the light diffusing material 73, and the phosphor particles that generate heat due to energy loss due to the Stokes shift are prevented from being concentrated locally. Therefore, the amount of the light diffusing material can be reduced and the local heat generation of the color conversion member 70 can be suppressed, and the light conversion efficiency of the phosphor particles can be improved. It is possible to prevent a reduction in reliability of the color conversion member 70 together.

Here, as the material of the light diffusing material 73, for example, a transparent inorganic material such as SiO ₂ (glass), TiO ₂ , Al ₂ O ₃ is preferably employed. The diffusion effect increases as the refractive index of the light diffusing material 73 increases.

  The base material of the color conversion member 70 is not limited to the silicone resin, and may be glass. If glass is used, the temperature of the color conversion member 70 is increased as compared with the case where the base material is an organic material such as a silicone resin. Can be suppressed. The base material of the color conversion member 70 may be a high melting glass, and the diffusion material 73 may be a low melting glass.

  Further, the light diffusing material 73 is not limited to the spherical glass, and may be composed of glass fiber, mesh-like glass, metal nanoparticles, or the like. Here, if a glass fiber is adopted as the light diffusing material 73, heat generated in the phosphor particles of the color conversion member 70 can be efficiently radiated as compared with the case where the light diffusing material 73 is spherical glass. Thus, local heat generation of the color conversion member 70 can be further suppressed. If metal nanoparticles (for example, nanoparticles of noble metals such as gold and silver) are employed as the light diffusing material 73, surface plasmon polaritons are excited in the light diffusing material 73 by the light from the LED chip 10, and the LED chip 10. Since the light from the light is enhanced, the light extraction efficiency to the outside can be increased.

  In the light emitting device 1 of the present embodiment, the dome-shaped optical member 60 disposed so as to surround the LED chip 10 between the mounting substrate 20 and the inner side of the color conversion member 70, and the inner side of the optical member 60. And the sealing portion 50 that seals the LED chip 10, and the air layer 80 is formed between the color conversion member 70 and the optical member 60. Of the light scattered by the phosphor particles, the amount of light scattered to the optical member 60 side and transmitted through the optical member 60 can be reduced, and the light output can be improved by improving the light extraction efficiency to the outside as the entire apparatus. .

(Embodiment 2)
The basic configuration of the light emitting device 1 of the present embodiment is substantially the same as that of the first embodiment. As shown in FIG. 8, the mounting substrate 20 has an electrical insulating property such as a ceramic substrate (for example, an alumina substrate or an aluminum nitride substrate). However, it is different in that it is formed using an insulating substrate 20a made of a ceramic substrate having a high thermal conductivity (in short, the mounting substrate 20 is formed of a thermally conductive material). In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  In the present embodiment, the mounting substrate 20 has two conductor patterns 23 and 23 electrically connected to the respective electrodes of the LED chip 10 so as to straddle one surface, the side surface, and the other surface of the insulating substrate 20a. The portions formed on the other surface side of the insulating substrate 20 constitute external connection electrode portions 23b and 23b, and the planar size is larger than that of the LED chip 10 at the central portion of the other surface of the insulating substrate 20. A rectangular heat-dissipating conductor 126 is formed. Here, in the light emitting device 1 of the present embodiment, the LED chip 10 is mounted on the one conductor pattern 23 on the one surface side of the insulating substrate 20a, but the submount member 30 described in the first embodiment. You may make it mount on the conductor pattern 23 via. Alternatively, the conductor patterns 23 and 23 may be provided only on the one surface side of the insulating substrate 20a, and a part of each of the conductor patterns 23 and 23 may be used as external connection electrode portions 23b and 23b.

  In the light emitting device 1 of the present embodiment, as in the first embodiment, the color conversion member 70 uses a light diffusing material 73 having a refractive index different from that of the base material and the relative incident light intensity based on the orientation characteristics of the LED chip 10 is a specified value. The amount of the light diffusing material 73 can be reduced and local heat generation of the color conversion member 70 can be suppressed, and the light conversion efficiency of the phosphor particles can be improved. This makes it possible to prevent a decrease in the reliability of the color conversion member 70.

  Further, in the first embodiment, the mounting substrate 20 includes the heat transfer plate 21 made of a heat conductive material and the wiring substrate 22 using the organic insulating base material 22a, and is generated in the color conversion member 70. Although it is difficult for heat to be transferred to the mounting substrate 20, the light emitting device 1 of the present embodiment is formed by using the insulating substrate 20 a made of a heat conductive material in the light emitting device 1. The heat generated in 70 can be efficiently radiated through the mounting substrate 20, and the local heat generation of the color conversion member 70 can be further suppressed.

  In each of the above-described embodiments, a blue LED chip whose emission color is blue is used as the LED chip 10, and a SiC substrate is used as the crystal growth substrate. However, instead of the SiC substrate, a GaN substrate or A sapphire substrate may be used. When a SiC substrate or a GaN substrate is used, the crystal growth substrate has a higher thermal conductivity than the case where a sapphire substrate that is an insulator is used as the crystal growth substrate. The thermal resistance of the growth substrate can be reduced. The LED chip 10 has the anode electrode formed on the one surface side and the cathode electrode formed on the other surface side. The anode electrode and the cathode electrode are formed on the one surface side. In this case, both the anode electrode and the cathode electrode can be directly connected to the conductor patterns 23 and 23 via the bonding wires 14. Moreover, the light radiated | emitted from LED chip 10 is not restricted to blue light, For example, red light, green light, purple light, ultraviolet light etc. may be sufficient.

1 is a schematic cross-sectional view of a light emitting device according to Embodiment 1. FIG. It is a principal part schematic disassembled perspective view of the lighting fixture using the light-emitting device same as the above. It is a principal part schematic plan view of a light-emitting device same as the above. It is explanatory drawing of the manufacturing method of a light-emitting device same as the above. It is a principal part schematic disassembled perspective view of the lighting fixture using the light-emitting device same as the above. It is a principal part schematic perspective view of the lighting fixture using the light-emitting device same as the above. It is a principal part schematic disassembled perspective view of the lighting fixture using the light-emitting device of the other structural example same as the above. 6 is a schematic cross-sectional view of a light emitting device according to Embodiment 2. FIG. It is a schematic sectional drawing of the light-emitting device of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting device 10 LED chip 14 Bonding wire 20 Mounting board 21 Heat-transfer board 22 Wiring board 23 Conductor pattern 23b External connection electrode part 30 Submount member 50 Sealing part 60 Optical member 70 Color conversion member 70a Light incident surface 70b Light emission Surface 73 Light diffusing material 80 Air layer

Claims (6)

  An LED chip, a mounting substrate on which the LED chip is mounted, and a base material made of a light-transmitting material, phosphor particles that are excited by light emitted from the LED chip and emit visible light having a longer wavelength than the LED chip And a dome-shaped color conversion member disposed so as to surround the LED chip with the mounting substrate, and the color conversion member includes a light diffusion material having a refractive index different from that of the base material. A light emitting device characterized in that it is dispersed only in a prescribed region where the relative incident light intensity based on the orientation characteristics of the chip exceeds a prescribed value.   The light emitting device according to claim 1, wherein the base material is glass.   The light-emitting device according to claim 1, wherein the light diffusing material is made of glass fiber.   The light-emitting device according to claim 1, wherein the light diffusing material is made of metal nanoparticles.   The light-emitting device according to claim 1, wherein the mounting substrate is made of a heat conductive material.   A dome-shaped optical member disposed so as to surround the LED chip between the color conversion member and the mounting substrate; and a sealing portion that seals the LED chip inside the optical member. The light emitting device according to claim 1, further comprising an air layer formed between the color conversion member and the optical member.

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