Light-emitting device

Abstract

To provide a light-emitting device capable of achieving light emission of high luminance with high luminous efficiency, by increasing the optical coupling efficiency from a light-emitting element to a light transmitting member.SOLUTION: A light-emitting device includes: a light transmitting member having the light-emitting surface and the light-receiving surface of the light-emitting device; a light-emitting element including an emission surface facing the light-receiving surface, and being bonded to the light transmitting member; and a light guide member provided to extend from the light-emitting element surface to the light transmitting member surface, and guiding the emission light from the light-emitting element to the light transmitting member. The light guide member has: a junction region for bonding the emission surface of the light-emitting element and the light-receiving surface of the light transmitting member while facing each other; and a first coating region extending from the junction region, and covering the surface of one of the light-emitting element and light transmitting member projecting outward from the junction region. A first reflection surface for reflecting the emission light to the light transmitting member side is provided on the outer surface of the first coating region.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a light emitting device, and more particularly to a light emitting device including a light guiding member that enhances light emitting efficiency. [Background technology]

[0002] In recent years, light emitting devices equipped with semiconductor light emitting elements such as light emitting diodes (LEDs) and laser diodes (LDs) as light sources have been used in various lighting and display devices. In particular, these semiconductor light emitting elements have low power consumption and long life, so they have attracted attention as light sources for next-generation lighting that can replace fluorescent lamps, and there is a demand for further improvements in light output and light efficiency. In addition, there is a demand for light sources with good light distribution characteristics and high brightness, such as floodlights such as car headlights.

[0003] For example, Patent Document 1 proposes a light-emitting device in which an LED chip assembly, in which a phosphor chip is fixed to an LED chip with a light-transmitting adhesive, is mounted on the cup portion of a lead frame or on an insulating substrate, and the LED chip assembly is sealed with a protective layer or sealing resin mixed with a light-scattering agent. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-141559 A [Patent Document 2] JP 2007-019096 A [Patent Document 3] JP 2002-305328 A [Patent Document 4] Japanese Patent Application Publication No. 10-151794 [Patent Document 5] JP 2009-043764 A [Patent Document 6] JP 2008-300621 A [Patent Document 7] JP 2008-277592 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the light-emitting device described in the cited document 1, there is a risk that the light-transmitting adhesive for bonding the phosphor chip onto the LED chip will drip from the phosphor chip directly or along the side of the light-emitting element to the cup part of the lead frame or the insulating substrate, and the light emitted from the LED chip or the phosphor chip will be guided by the adhesive and absorbed by the surface of the insulating substrate or the electrodes or the lead frame provided thereon, resulting in a problem of a decrease in the light output of the light-emitting device. There is also a similar problem with the light-transmitting resin that covers the light-emitting element or the phosphor chip and the surfaces of the substrate, electrodes, etc. In addition, even if the light path through such a light-transmitting member is small and narrow, it has a large effect on the characteristics of the light-emitting device. Furthermore, the LED chip and the phosphor chip in the cited document 1 are merely fixed to each other at their opposing surfaces by an adhesive, and there is a concern that the coupling efficiency of the light emitted from the LED chip to the phosphor chip is low, and that if the outer shapes of the two chips are poorly matched, the brightness unevenness, color unevenness, and directivity will deteriorate.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a light-emitting device that can reduce the loss of light emitted from a light-emitting element to increase its utilization efficiency, increase the efficiency of optical coupling from the light-emitting element to a light-transmitting member, and increase the light-emitting efficiency and brightness. [Means for solving the problem]

[0007] The light emitting device according to the present invention can achieve the above object by having the following configurations (1) to (15). (1) A light emitting device comprising: a light-transmitting member having a light-emitting surface and a light-receiving surface; a light-emitting element having an exit surface facing the light-receiving surface and joined to the light-transmitting member; and a light-guiding member extending from the surface of the light-emitting element to the surface of the light-transmitting member and guiding light emitted from the light-emitting element to the light-transmitting member, wherein the light-guiding member has a joining region that joins the exit surface of the light-emitting element and the light-receiving surface of the light-transmitting member so as to face each other, and a first covering region that extends from the joining region and covers one of the surfaces of the light-emitting element and the light-transmitting member that protrudes outward from the joining region, and a first reflecting surface that reflects the exit light towards the light-transmitting member is provided on the outer surface of the first covering region. (2) The light emitting device according to (1) above, further comprising a covering member having a light reflective material, the covering member covering a surface of the light guiding member, exposing the light emitting surface and covering the surfaces of the light emitting element and the light transmitting member. (3) The light emitting device according to (1) or (2), wherein the light transmitting member is a wavelength converting member excited by the emitted light of the light emitting element. (4) A light-emitting device described in any one of (1) to (3) above, wherein the first covering region covers one of the protruding surfaces and the other side surface of the light-emitting element and the light-transmitting member, and the first reflecting surface is provided opposite the side surface. (5) The light-emitting device according to (4) above, wherein the covering member covers the surface of the other side via a light-guiding member of a first covering region, and covers the surface of the side of the light-emitting element or light-transmitting member exposed from the light-guiding member. (6) A light emitting device described in any one of (1) to (5) above, wherein a portion of the light receiving surface of the light transmitting member protrudes outward from the light exiting surface, and the first reflecting surface is an inclined surface inclined from a side surface of the light emitting element toward the light receiving surface. (7) The light emitting device according to (6) above, wherein the light receiving surface of the light transmitting member is larger than the light emitting surface of the light emitting element and includes the light emitting surface. (8) A light-emitting device according to any one of (1) to (5) above, wherein a portion of the light-emitting surface of the light-emitting element protrudes outward from the light-receiving surface, and the first reflecting surface is an inclined surface inclined from a side surface of the light-transmitting member toward the light-emitting surface. (9) The light emitting device according to (8) above, wherein the light emitting surface of the light emitting element is larger than the light receiving surface of the light transmitting member and includes the light receiving surface. (10) A light-emitting device as described in any of (1) to (9) above, wherein the light-emitting elements are spaced apart from one another and bonded in multiple to the light-receiving surface side of the light-transmitting member, the light-guiding member has a second covering region extending from the bonding region to cover a portion of the light-receiving surface sandwiched between the spaced apart light-emitting elements, and a second reflecting surface is provided on the outer surface of the second covering region to reflect the emitted light from each of the adjacent light-emitting elements toward the light-receiving surface side. (11) The light emitting device according to (10), wherein the second covering region covers opposing side surfaces of the spaced apart light emitting elements. (12) The light emitting device according to (10) or (11) above, in at least one set of the plurality of light emitting elements, the distances from the light emitting surfaces to the light receiving surfaces of the light transmitting members are different from each other. (13) A light-emitting device according to any one of (1) to (12) above, wherein the light-emitting element has a semiconductor layer and a substrate on the light-emitting surface side of the semiconductor layer, and the light-guiding member extends to and covers a side surface of the substrate, exposing a side surface of the semiconductor. (14) The light emitting device according to any one of (1) to (13) above, further comprising a covering member that contains a light reflective material, exposes the light emitting surface, and covers the light emitting element and a part of the light transmitting member, and the first reflecting surface or the second reflecting surface is provided at the interface between the light guiding member and the covering member. (15) The light emitting device according to any one of (1) to (14) above, wherein the first reflecting surface or the second reflecting surface is a convex curved surface that is convex toward the side surface. Effect of the Invention

[0008] According to the present invention, by joining the light-transmitting member and the light-emitting element arranged opposite to each other with the light-guiding member provided between them and in the area extending therefrom, it is possible to efficiently extract light from the light-emitting element, guide the light, and optically couple it to the light-transmitting member, thereby providing a light-emitting device capable of emitting light with high light-emitting efficiency and high brightness. In addition, by further covering the light-transmitting member and the light-emitting element joined by the light-guiding member with a light-reflective covering member to provide a light-emitting device with a light-emitting surface on a part of the light-transmitting member, it is possible to provide a light-emitting device that can guide light more efficiently, and when the light-transmitting member is a wavelength conversion member, it is possible to provide a light-emitting device that has light distribution characteristics with less color unevenness, high light-emitting efficiency, and can emit light with high brightness. In addition, with such a structure, the outer shape, size, and arrangement of the light-emitting element and the light-transmitting member can be made different, thereby making it possible to obtain a light source with a desired shape and outer dimensions, and therefore it is possible to obtain a light-emitting device that is easy to miniaturize, and furthermore, it is possible to provide a light-emitting device that can adjust light-emitting characteristics such as luminous flux and brightness as appropriate. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2B is a schematic top view of a light emitting device according to one embodiment of the present invention, and FIG. 2A is a schematic cross-sectional view taken along the line AA of the light emitting device. [Diagram 2] 1 is a schematic cross-sectional view illustrating the periphery of a light source unit of a light emitting device according to an embodiment of the present invention. [Diagram 3] FIG. 4 is a schematic cross-sectional view illustrating the periphery of a light source unit of a light-emitting device according to a comparative example of the present invention. [Figure 4] 1 is a schematic cross-sectional view of a light-emitting element according to an embodiment of the present invention. [Diagram 5] FIG. 1A is a schematic cross-sectional view of a light-emitting device according to an embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view illustrating the periphery of a light source unit thereof. [Figure 6] 1 is a schematic cross-sectional view illustrating the periphery of a light source unit of a light emitting device according to an embodiment of the present invention. [Figure 7] 1 is a schematic cross-sectional view illustrating the periphery of a light source unit of a light emitting device according to an embodiment of the present invention. [Figure 8] 1 is a schematic cross-sectional view illustrating a light emitting device according to an embodiment of the present invention. [Figure 9] 1 is a schematic cross-sectional view illustrating a light emitting device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments of the invention will be described with reference to the drawings as appropriate. However, the light-emitting element and device described below are intended to embody the technical idea of ​​the present invention, and the present invention is not limited to the following. In particular, the dimensions, materials, shapes, and relative positions of the components described below are not intended to limit the scope of the present invention, and are merely illustrative examples, unless otherwise specified. The sizes and positional relationships of the components shown in each drawing may be exaggerated to clarify the explanation. Furthermore, each element constituting the present invention may be configured with the same material so that multiple elements are used by one material, or conversely, the function of one material may be shared by multiple materials. Similarly, in each embodiment described below, each configuration may be appropriately combined and applied unless otherwise specified to exclude.

[0011] The light emitting device of the present invention is mainly composed of a light emitting element 10, a light transmitting member 20, and a light guiding member 30, as shown in Figs. 1 and 2. The light emitting element 10 has an emission surface, and the light transmitting member 20 has a surface 21 (light emitting surface 90) exposed to the outside, a light receiving surface 22 facing the surface 21, and a side surface. The light emitting element 10 is disposed so that its emission surface faces the light receiving surface 22 of the light transmitting member, and one of the light emitting element 10 and the light transmitting member 20 protrudes outward from the other member. The light guiding member 30 can be applied with an adhesive for fixing the light emitting element 10 and the light transmitting member 20, and is translucent and provided so as to extend between the surface of the light emitting element and the surface of the light transmitting member, specifically from the surface of the light emitting element to the surface of the light transmitting member, and has a function of guiding the emitted light of the light emitting element 10 to the light transmitting member 20. The light guide member 30 has a joining region 31 that joins the emission surface of the light emitting element and the light receiving surface 22 of the light transmitting member, which face each other, and a covering region (32, 37) that extends from the joining region and covers the protruding surface (a part of the emission surface of the light emitting element or the light receiving surface 22 of the light transmitting member). The light guide member is spaced from the mounting surface of the board and is located on the light transmitting member 20 side, retreating from the mounting surface of the light emitting element 10. Therefore, it is possible to prevent the light emitted from the light emitting element 10 from being guided to the board 50 through the light guide member 30 and being absorbed. A reflecting surface that reflects the light emitted from the light emitting element 10 toward the light transmitting member 20 side is provided on the outer surface of the covering region. In this way, the reflection on the outer surface of the light-guiding member 30 suppresses light diffusion and focuses the light in the light-guiding member 30, making it possible to guide the light to the light-transmitting member 20, thereby reducing the loss of light due to absorption and allowing the light emitted from the light-emitting element 10 to be efficiently coupled to the light-transmitting member 20, thereby improving the luminance distribution of the light-emitting surface. In addition, by bonding the light-emitting element and the light conversion member, it is possible to achieve a good distribution of luminance and chromaticity within the light-emitting surface.

[0012] 1, 2, 5 and 6, it is preferable that the covering region is covered so as to connect the surface of the protrusion with the other side, and the reflecting surface is provided on the outer surface of the light-guiding member facing the covered side. By making the inclined surface connecting the surface of one protrusion with the other side the outer surface, the outward bulging of the covering region is suppressed, and the optical path length of the light reflected on the outer surface to the light-transmitting member 20 is shortened. Furthermore, since the outer surface is a concave curved surface, it becomes a convex curved reflecting surface, and the light-guiding function of the light-guiding member 30 can be improved.

[0013] In addition, as shown in Figs. 1 and 2, the light-emitting device of the present invention further includes a light-reflective covering member 40, and a part of the light-emitting element 10 and the light-transmitting member 20 is covered with this covering member 40, so that the exposed surface 21 of the light-transmitting member can be used as the light-emitting surface 90 of the device, and the light-emitting device can be a surface-emitting type light-emitting device. The covering member 40 also functions as a filler or sealant containing a light-reflective material 45, and can realize a miniaturization of the light-emitting device. In addition, by covering the surface of the light-guiding member 30 with the light-reflective material, the light-guiding action can be assisted, and the optical coupling efficiency of the light emitted from the light-emitting element 10 to the light-transmitting member can be further improved. In addition, it is preferable to provide an area covered by the light-guiding member and an area exposed from the area on the surface of the light-emitting element and the light-transmitting member, and to cover these areas with the covering member, that is, to cover the exposed area directly and the covered area via the light-guiding member. Specifically, the covering member covers one side surface in the above-mentioned covered area via the light-guiding member 30, and covers the other side surface exposed from the light-guiding member 30. As a result, the light reflection function of the covering member strengthens the light confinement effect in the light guide member 30 in the covered region, while restricting the light propagation region from the light emitting element 10 to the light transmitting member 20 in the exposed region, so that the light guide member 30 can efficiently guide the light to the light transmitting member 20. Furthermore, the reflecting surface of the covering region is preferably provided at the interface between the light guide member and the covering member, which further enhances the function. With this configuration, the utilization efficiency of the light emitted from the light emitting element 10 can be improved, and high-luminance light emission with less color unevenness and excellent light distribution characteristics can be achieved.

[0014] (Embodiment 1) 1 and 2 show a light-emitting device 100 according to the first embodiment of the present invention, and the cross section of FIG. 1(a) is a schematic cross section of the top surface taken along line AA of FIG. 1(b), and FIG. 2 is a schematic cross section of the light source portion and its periphery. The light-emitting device 100 shown in FIG. 1 is a surface-emitting type light-emitting device having a light-emitting surface 90. The light-emitting device 100 mainly includes a light-emitting element 10 having a semiconductor element structure 11 on a growth substrate 1, a plate-shaped light-transmitting member 20 having an exposed surface 21 that serves as the light-emitting surface 90 and a light-receiving surface 22 that faces the surface 21, a light-guiding member 30 that guides the light emitted from the light-emitting element 10 to the light-transmitting member 20, and a covering member 40 that contains a light-reflective material 45. The light-emitting element 10 is flip-chip mounted on the wiring layer 51 of the substrate 50 with the light-emitting surface, which is the back surface of the growth substrate 1, facing the light-receiving surface 22 of the light-transmitting member, and is optically coupled to the light-transmitting member 20 by the intervening light-guiding member 30. A frame 55 is provided on the substrate 50 to surround the light emitting element 10 and the light transmitting member 20, and the inside of the frame 55 is filled with a covering member 40, and the light emitting element 10 and a part of the light transmitting member 20 are covered by the covering member 40. The light emitting region of the light emitting device 100, i.e., the window portion for emitting light, is substantially limited to the surface 21 of the light transmitting member 20, and the surface 21 is the light emitting surface 90, forming a surface-emitting type light emitting device. In addition, the light emitting device 100 is capable of controlling the luminance and light distribution of the light emitted from the surface 21, i.e., the light emitting surface 90, depending on the shape and size of the surface 21 of the light transmitting member 20. Furthermore, the light emitting device has relatively uniform luminance and chromaticity in the light emitting surface. Here, the planar shape of the light transmitting member and the light emitting element is rectangular as shown in the figure, and the light emitting element is enclosed in the light transmitting member in the plane.

[0015] The light source unit will be described in detail with reference to FIG. 2. The light guide member 30 has a bonding region 31 that bonds the light emitting element 10 and the light transmitting member 20 to each other in opposition, and more specifically, is provided in a region of the light receiving surface 22 of the light transmitting member that faces the emission surface of the light emitting element 10. In a specific example, for example, in an embodiment described later, the thickness of this bonding region is about 0.01 μm to 100 μm. The light guide member 30 is interposed in the bonding region, so that the light emitting element and the light transmitting member are separated from each other, and the refractive index difference in the emission surface of the light emitting element 10 is alleviated compared to the case where a gas such as the atmosphere is interposed, and light can be efficiently extracted from the light emitting element 10. Therefore, the light from the emission surface of the light emitting element 10 is transmitted into the bonding region 31 and directly optically coupled to the light receiving surface 22 of the light transmitting member.

[0016] In this embodiment, the light receiving surface 22 of the light transmitting member is larger than the emission surface of the light emitting element 10, and a part of the light receiving surface 22 is included and protrudes outward from the emission surface of the light emitting element 10. In other words, the side surface of the light transmitting member 20 is located outside the side surface of the light emitting element 10, and a protrusion is provided on the entire periphery. In such a light emitting device 100, the light emitting surface 90 of the light emitting device is a window for emitting light that is relatively larger than the emission surface of the element, and the luminous flux of the emitted light can be increased. The light guide member 30 has a first covering region 32 that extends from the above-mentioned bonding region 31 and covers the protruding surface of the light transmitting member and the side surface of the light emitting element 10 that hangs down from a part of the side surface, and specifically, this region is provided in a region that protrudes outward from the above-mentioned bonding region. Here, since the light emitted from the light emitting element 10 is usually emitted not only from the emission surface but also from the side surface and bottom surface side (mounting surface side), a part of the light is mainly incident on the first covering region 32 from the side surface of the light emitting element and guided. That is, in the first covering region 32, as in the case of the above-mentioned bonding region, the refractive index difference of the emitting surface of the light emitting element can be alleviated, and the light extraction efficiency can be increased. Here, the outer surface of the first covering region 32 facing the covering member 40 side, i.e., the outer surface of the first covering region 32 facing the side surface of the light emitting element 10, has a first reflecting surface 33 that reflects the emitted light of the light emitting element 10 to the light transmitting member 20 side, and therefore the reflected light of the emitted light is reflected by the first reflecting surface 33 to the light receiving surface 22 side of the light transmitting member 20 and guided, and is optically coupled to the light transmitting member 20. In this way, by once extracting the emitted light from the light emitting element 10 to the side inside the light guiding member 30 and then reflecting it by the first reflecting surface 33, the loss of light due to absorption in the light emitting element 10 can be reduced compared to the form in which the light emitting element 10 is exposed from the light guiding member and directly covered with the light reflective covering member 40, and the light is once propagated and spread inside the light guiding member, so that the optical coupling efficiency and light emitting characteristics can be improved.

[0017] As described above, as shown in FIG. 1 and FIG. 2 in this embodiment, the first reflection surface 33 of the light guide member 30 is provided at the interface with the covering member 40, thereby enhancing the reflection function. In addition, since the interface is composed of the light-transmitting light guide member 30 and the covering member 40 containing a light-reflective material in a light-transmitting base material, it becomes a gentle reflection interface that seeps into the covering member. This configuration can be easily formed by filling the covering member 40 after forming the first covering region 32 on the light guide member 30, and is a structure with excellent mass productivity. Note that the first reflection surface 33 does not necessarily have to be provided at the interface with the covering member 40. For example, the outer surface of the first covering region 32 facing the covering member 40 side and the covering member 40 may be separated, and a gap may be provided between them, and the first reflection surface 33 may be provided at the interface between the light guide member 30 and air. According to this embodiment, the light guide member 30 side at this interface has a high refractive index, and a lot of light can be reflected in the first covering region 32. Furthermore, the light components transmitted into the gap from the first covered region 32 can also be reflected again by the surface of the covering member 40. In addition to this form, for example, the first reflecting surface 33 may be formed by providing the outer surface of the first covered region 32 with a highly reflective metal film such as silver (Ag) or aluminum (Al), a dielectric multilayer film, or a layer made of translucent particles.

[0018] In the light emitting device 100, the surface of the first covering region 32 facing the side surface of the light emitting element 10 is preferably an inclined surface inclined from the side surface toward the light receiving surface 22 of the light transmitting member. This allows the light emitted laterally from the light emitting element 10 to be reflected favorably toward the light receiving surface 22 of the light transmitting member, and also allows favorable optical coupling due to the cross-sectional width expanding toward the protruding surface. Furthermore, this inclined surface may be flat, but it is preferable that it is a convex curved surface that is convex toward the bonding region 31, since this increases the surface area of ​​the first reflecting surface 33 compared to the case where it is flat, and improves the light reflection efficiency.

[0019] The method for forming the first covered region 32 is not particularly limited, but for example, the first covered region 32 can be formed by applying an appropriate amount of the resin material constituting the light guide member 30 onto the emission surface of the light emitting element 10, and then mounting the light transmitting member 20. At this time, the light transmitting member 20 may be appropriately pressed. The resin can be applied by a dispensing method, a stamping method, or the like, and the light transmitting member 20 can be placed in mass production by a die bonding device equipped with a collet that can adsorb, transport, and press the light transmitting member 20.

[0020] The resin material constituting the light guide member 30 may drip directly from the protruding portion of the light emitting element 10 or the light transmitting member 20 or drip along the side of the light emitting element 10 and reach the mounting substrate 50. FIG. 3 is a schematic cross-sectional view for explaining an embodiment in which a hanging portion is provided on such a light guide member 36. In this embodiment compared to the present invention, as shown in FIG. 3, when the adhesive resin of the light guide member 36 drips continuously along the side of the light emitting element 10 to the mounting substrate 50, a light path is formed at the hanging portion. Therefore, the light emitted from the light emitting element 10 to the side or downward is guided to the mounting substrate 50 side by the hanging portion and reaches the surface or wiring 51 of the mounting substrate 50, causing light loss due to absorption. In addition, the formation of the hanging portion may block the formation of the underfill 70 or the like and the infiltration of the covering member 40 into the region between the light emitting element 10 and the substrate 50, and light loss occurs when the light leaks due to the hollowing out. In particular, if the amount of resin material applied is too large, the light guide member 36 may hang down directly from the protruding portion of the light transmitting member 20 onto the substrate 50, or may be separated from the above-mentioned bonding region to bridge the light emitting element 10 and the substrate 50, forming an optical path similar to the above, which may cause light loss. In addition, in the third embodiment described below, a hanging portion that covers the side surface and reaches the mounting substrate in the same manner may be provided, although this structure is more difficult to form than the case in which the light transmitting member protrudes as in this embodiment. Therefore, the amount of resin material applied is appropriately adjusted so as not to be excessive, and is adjusted by the area of ​​the protruding surface and the position of the protruding portion as described below.

[0021] Therefore, the outer surface of the first covering region 32 is preferably located closer to the light transmitting member 20 than the bottom surface and mounting surface of the light emitting element 10, and the range covered by the first covering region 32 is preferably up to the middle of the side surface of the light emitting element 10. That is, as shown in Figs. 1 and 2, it is desirable that the side surface of the light emitting element 10 has a covered region (first covering region 32) on the emission surface (upper) side with respect to the light guide member and a region exposed on the bottom surface and mounting surface (lower) side. Furthermore, it is preferable that this exposed region is covered with the covering member 40. More specifically, when the light emitting element 10 has a semiconductor layer 11 as an element structure and a substrate 1 on the emission surface side of the semiconductor layer, it is preferable that the light guide member 30 extends to cover the side surface of the substrate and exposes the side surface of the semiconductor layer 11. This can increase the light reflectivity of the semiconductor layer 11 side including the light emitting layer while increasing the light transmittance of the substrate side. In addition, the first covering region 32 may be formed to extend uniformly from the junction region 31 to the side surface of the light-emitting element 10, or may be formed to hang down discretely and partially from the junction region 31 to the side surface of the light-emitting element 10.

[0022] Such a form can be easily achieved by surface-treating the area to be exposed from the light guide member 30 in advance, such as by applying a release agent, so that the area is difficult to cover with the light guide member 30. A generally commercially available release agent can be used, and for example, a fluorine-based release agent such as Daifree, a spray type, or Optool, a liquid type, manufactured by Daikin Co., Ltd., can be used. In particular, it is preferable that the surface facing the emission surface of the light emitting element 10, the mounting surface, is surface-treated, and further, it is preferable that a part of the side surface continuing from there, particularly the side surface of the semiconductor layer 11, i.e., the exposed surface of the semiconductor layer 11, is surface-treated. In addition, this surface treatment does not have to coincide with the covering member 40, and there are cases where they overlap or are separated from each other.

[0023] 1 and 2, the side surface of the light-transmitting member 20 is preferably exposed from the light-guiding member 30 and further covered with a light-reflective covering member 40. In this way, compared to the case where the light-guiding member 30 covers the side surface of the light-transmitting member 20, the outward bulge of the outer surface of the light-guiding member 30 can be suppressed, and therefore the optical path length to the light-transmitting member 20 can be shortened, and the optical coupling efficiency can be improved. In addition, as described above, it is preferable because it becomes easier to form the first reflecting surface 33 having a shape and an inclination angle suitable for reflecting light toward the light-receiving surface 22.

[0024] Next, each of the components and structure of the light emitting device of the present invention will be described in detail below.

[0025] (Light emitting element) The light emitting element 10 can be a known one, specifically a semiconductor light emitting element, and in particular, a GaN-based compound semiconductor is preferable because it can emit short wavelength visible light or ultraviolet light that can efficiently excite fluorescent materials. A specific emission peak wavelength is 240 nm or more and 560 nm or less, preferably 380 nm or more and 470 nm or less. In addition, ZnSe-based, InGaAs-based, and AlInGaP-based semiconductor light emitting elements may also be used.

[0026] (Light emitting device structure) The light emitting element structure 11 made of semiconductor layers is preferably a structure that is composed of at least a first conductivity type (n-type) layer 2 and a second conductivity type (p-type) layer 3, as exemplified in FIG. 4, and further has an active layer 3 therebetween. The electrode structure is preferably a same-side electrode structure in which both electrodes 6, 7 of a first conductivity type (negative) and a second conductivity type (positive) are provided on one main surface side, but an opposing electrode structure in which electrodes are provided facing each main surface of the semiconductor layer may also be used. Regarding the mounting form of the light emitting element 10, for example, in the same-side electrode structure, flip-chip mounting in which the electrode formation surface is used as the mounting surface and the opposing substrate 1 side is used as the main emission surface is preferred in terms of optical connection between the emission surface and the light transmitting member 20. In addition, mounting in which the electrode formation surface side is used as the main emission surface and a light transmitting member is bonded thereon, flip-chip mounting, etc. may also be used. The light-transmitting member can be mounted face-up, flip-chip mounted on a light-transmitting member having a wiring structure, and connected to a mounting substrate by the above-mentioned opposing electrode structure. Preferably, the light-emitting element and the light-transmitting member are not provided with wiring or electrodes. The growth substrate 1 of the semiconductor layer 11 may be removed when the light-emitting element structure is not formed, and a support substrate, for example, a conductive substrate or another light-transmitting member / substrate, can be bonded to the semiconductor layer from which the growth substrate has been removed. The light-transmitting member 20 can be used as this support substrate, or the semiconductor layer can be bonded / covered with a light-transmitting member such as glass or resin and supported. The growth substrate can be removed by, for example, mounting or holding on a support, device, or submount, peeling, polishing, or LLO (Laser Lift Off). Furthermore, the light-emitting element 10 can have a light reflection structure, and specifically, of the two opposing main surfaces of the semiconductor layer 11, the other main surface opposing the light extraction side (emission surface side) is set as the light reflection side (lower side in FIG. 1), and a light reflection structure can be provided in the semiconductor layer on this light reflection side, in an electrode, etc. Examples of the light reflection structure include a structure in which a multilayer film reflection layer is provided in the semiconductor layer, or a structure in which an electrode and a reflection layer having a metal film with high light reflectivity such as Ag or Al or a dielectric multilayer film are provided on the semiconductor layer.

[0027] (Nitride semiconductor light emitting device) As an example of the light emitting device 10, in the nitride semiconductor light emitting device 10 of FIG. 4, an n-type semiconductor layer as the first nitride semiconductor layer 2, a light emitting layer as the active layer 3, and a p-type semiconductor layer as the second nitride semiconductor layer 4 are epitaxially grown in this order on a C-plane sapphire substrate as the growth substrate 1. A part of the n-type layer 2 is exposed to form an n-type pad electrode as the first electrode 7, and a light-transmitting conductive layer 5 such as ITO and a p-type pad electrode as the second electrode 6 are formed on almost the entire surface of the p-type layer 4. Furthermore, a protective film 8 is provided by exposing the surfaces of the n-type and p-type pad electrodes 6, 7 and covering the semiconductor layers. The n-type pad electrode 7 may be formed through a light-transmitting conductive layer, similar to the p-type. The growth substrate 1 may be an insulating substrate such as C-plane sapphire, R-plane, A-plane, or spinel (MgAl2O4), or a conductive substrate made of a semiconductor such as silicon carbide (6H, 4H, 3C), Si, ZnS, ZnO, GaAs, GaN, or AlN. Examples of nitride semiconductors include those made of nitrides with the general formula In x Al y Ga 1-x-y In addition to N (0≦x, 0≦y, x+y≦1), B, P, and As may be mixed crystals. The n-type and p-type semiconductor layers 2, 4 are not particularly limited to single layer or multilayer, and the active layer 3 is preferably a single (SQW) or multiple quantum well structure (MQW). An example of a blue light emitting device structure 11 is a structure in which, on a sapphire substrate, a nitride semiconductor underlayer such as a buffer layer, for example, a low-temperature grown thin film GaN and GaN layer, as n-type semiconductor layers, for example, an n-type contact layer of Si-doped GaN and an n-type multilayer film layer of GaN / InGaN are laminated, followed by an active layer of InGaN / GaN MQW, and further, as p-type semiconductor layers, for example, a p-type multilayer film layer of Mg-doped InGaN / AlGaN and a p-type contact layer of Mg-doped GaN are laminated.

[0028] (Light-transmitting material) 1 also includes a light-transmitting member 20 that transmits light from the light-emitting element 10. The light-transmitting member 20 is preferably a light-converting member having a wavelength conversion material capable of converting the wavelength of at least a portion of the light passing through it. For example, as in the embodiment, primary light from the light source excites a phosphor serving as a wavelength conversion material in the light-transmitting member 20, thereby obtaining secondary light having a wavelength different from that of the primary light, and further mixing the secondary light with the primary light to realize emitted light having a desired hue.

[0029] As described above, the light transmitting member 20 of the first embodiment contains the light emitting element 10 in a plan view from the surface 21 (light emitting surface 90), and the side surface of the light transmitting member 20 protrudes outward from the side surface (end surface) of the light emitting element 10, and the light receiving surface 22 is wider than the emission surface of the light emitting element 10 and is optically connected via a light guiding member, so that loss is small. The protruding length of the side surface of the light transmitting member relative to the side surface of the light emitting element is, for example, 0.25 times or more and 5 times or less, specifically 0.5 times or more and 2 times or less, compared to the thickness of the light emitting element. For example, in the light emitting device of the first embodiment, the end of the light transmitting member 20 protrudes with a width of about 50 μm. In addition, as shown in the third embodiment described later, the side surface of the light transmitting member may be located inside the side surface of the light emitting element, that is, the emission surface of the light emitting element may protrude, and the light receiving surface 22 of the light transmitting member may be smaller than the emission surface of the light emitting element 10 as in this example. In this embodiment, the protruding length is, for example, 0.25 to 5 times, specifically 0.5 to 2 times, the thickness of the light-transmitting member. By narrowing the light-emitting region relative to the light-emitting element, the luminance is relatively increased, the mixed colors are uniformed, and color unevenness is reduced. In addition, if the side surface of the light-transmitting member 20 is positioned on approximately the same plane as the side surface of the light-emitting element 10, it is possible to suppress the occurrence of color unevenness due to a lack of light from the light-emitting element 10 at the outer edge of the light-transmitting member.

[0030] Here, as the light-transmitting material that is the base material of the light-transmitting member 20, a material similar to the covering member 40 described below can be used, and for example, an inorganic material such as resin or glass can be used. Even if the light-transmitting member does not have a conversion function, it is preferable to use a material similar to the light-transmitting member for light conversion, excluding or replacing the phosphor. In addition, when the light-transmitting member is plate-shaped as in the embodiment, it is preferable that both surfaces of the surface 21 and the light-receiving surface 22 are substantially flat surfaces, and further, the opposing surfaces are substantially parallel to each other, which increases the efficiency of optical coupling via the light-guiding member of the present invention and makes it easier to join. On the other hand, it is not limited to a plate-like shape, and various shapes or forms such as a shape having a curved surface in the whole or part, a planar shape such as an uneven surface, for example, a shape for collecting and dispersing light, for example, an optical shape such as a lens shape, can be used. In addition, as a wavelength conversion function, in addition to emitting a mixed light of the primary light of the light-emitting element and the converted light (secondary light), it can also be a light-emitting device that mainly emits secondary light converted from the primary light, such as converted light by ultraviolet light of the light-emitting element, or mixed light by multiple converted lights.

[0031] The light-transmitting member 20 with wavelength conversion function is specifically composed of a glass plate, a light-transmitting member, or a phosphor crystal or a single crystal, polycrystalline, amorphous, or ceramic body having the phase of the phosphor crystal of the light-transmitting member, or a sintered body, aggregate, or porous material with a light-transmitting material added appropriately, or a light-transmitting material such as a translucent resin mixed or impregnated therein, or a light-transmitting member containing phosphor particles, such as a molded body of a translucent resin. Note that, from the viewpoint of heat resistance, it is preferable that the light-transmitting member 20 is composed of an inorganic material rather than an organic material such as a resin. Specifically, it is preferable that the light-transmitting member 20 is composed of a translucent inorganic material containing a phosphor, and in particular, a sintered body of a phosphor and an inorganic substance (binding material, binder), or a sintered body or crystal of a phosphor is used to increase reliability. In addition, when using the YAG phosphor of the embodiment, in addition to YAG single crystals and high-purity sintered bodies, YAG / alumina sintered bodies using alumina (Al2O3) as a binder, and sintered bodies using glass as a binder are preferable from the viewpoint of reliability. Furthermore, by making the light-transmitting member 20 plate-shaped, the coupling efficiency with the emission surface of the planar light-emitting element 10 is good, and it is easy to align the light-transmitting member 20 so that it is approximately parallel to the main surface. In addition, by making the thickness of the light-transmitting member 20 approximately constant, the amount of wavelength conversion of the passing light is approximately uniform, the ratio of color mixing is stabilized, and color unevenness in the light-emitting surface 90 can be suppressed. Therefore, when a plurality of light-emitting elements 10 are mounted on one light-transmitting member 20, there is little unevenness in the distribution of brightness and chromaticity in the light-emitting surface 90 due to the arrangement of the individual light-emitting elements 10, and approximately uniform and high-brightness light emission can be obtained. In terms of luminous efficiency and chromaticity adjustment, the thickness of the light transmitting member 20 having a wavelength conversion function is preferably 10 μm or more and 500 μm or less, and more preferably 50 μm or more and 300 μm or less.

[0032] The wavelength conversion material can be suitably combined with a blue light emitting element to produce white light emission. Representative phosphors used in the wavelength conversion material include YAG phosphors (yttrium aluminum garnet) and LAG phosphors (lutetium aluminum garnet) bound with cerium in a garnet structure. In particular, when used for a long period of time at high brightness, the (Re1-x Sm x )3(Al 1-y Ga y )5O 12 :Ce (0≦x<1, 0≦y≦1, where Re is at least one element selected from the group consisting of Y, Gd, La, and Lu), etc. are preferred. Also, a phosphor containing at least one selected from the group consisting of YAG, LAG, BAM, BAM:Mn, (Zn, Cd)Zn:Cu, CCA, SCA, SCESN, SESN, CESN, CASBN, and CaAlSiN3:Eu can be used. In addition to the light-transmitting member, the wavelength conversion member can also be provided, for example, between the light-transmitting member and the light-emitting element, in the bonding member, or between the light-emitting element and the covering member. The light-transmitting member, the wavelength conversion member, and the sintered body can also be disposed in the light-emitting device. The reddish component can be increased by using a nitride-based phosphor having yellow to red light emission, and lighting with a high average color rendering index Ra, a warm white LED, etc. can also be realized. Specifically, by adjusting the amount of phosphors with different chromaticity points on the CIE chromaticity diagram to match the emission wavelength of the light-emitting element, it is possible to emit light at any point on the chromaticity diagram between the phosphors and the light-emitting element. In addition, nitride phosphors, oxynitride phosphors, and silicate phosphors that convert near-ultraviolet to visible light into the yellow to red range can be used. For example, L2SiO4:Eu (L is an alkaline earth metal), especially (Sr x Mae 1-x )2SiO4:Eu (Mae is an alkaline earth metal such as Ca or Ba). Examples of nitride phosphors and oxynitride phosphors include Sr-Ca-Si-N:Eu, Ca-Si-N:Eu, Sr-Si-N:Eu, Sr-Ca-Si-ON:Eu, Ca-Si-ON:Eu, Sr-Si-ON:Eu, etc. Examples of alkaline earth silicon nitride phosphors include those with the general formula LSi2O2N2:Eu and those with the general formula L x S y N (2 / 3x+4 / 3y) :Eu or L x S y O z N (2 / 3x+4 / 3y-2 / 3z) :Eu (L is Sr, Ca, or Sr and Ca).

[0033] (Covering material) As shown in FIG. 1, the covering member 40 covers a part of the light-transmitting member 20, specifically, covers at least a part of the side surface of the light-transmitting member 20. In the present invention, the covering member is suspended from the element or the like to prevent the formation of a light leakage path, so that the reflectance of the covering member is preferably higher than that of the substrate and further the wiring provided thereon. In addition, the base material of the covering member 40 containing the light-reflecting material is preferably a light-transmitting resin material, and it is preferable to use a silicone resin composition, a modified silicone resin composition, or the like, but an insulating resin composition having light transmittance such as an epoxy resin composition, a modified epoxy resin composition, or an acrylic resin composition can be used. In addition, a covering member having excellent weather resistance, such as a hybrid resin containing at least one of these resins, can also be used. Furthermore, inorganic substances having excellent light resistance such as glass and silica gel can also be used. In addition, by molding the resin material, it can be molded into a desired shape and can cover a desired area, and in the present invention, it can be formed by covering the surfaces of the light-emitting element, the light-guiding member, and the light-transmitting member of the light source unit, particularly their side surfaces. Similarly, the surface on the light emitting side can be formed into a desired shape, and can be a flat surface as shown in the figure, or a concave or convex curved surface. In the first embodiment, silicone resin is used as the covering material from the viewpoint of heat resistance and weather resistance.

[0034] Moreover, the covering member 40 contains at least one type of light-reflecting material 45 in the base material. By containing the light-reflecting material 45, the reflectance of the covering member 40 is increased, and more preferably, by using low-absorption particles, light absorption and loss are reduced, and the covering member can be provided with light scattering properties. The light-reflecting material 45 contained in the covering member 40 is at least one type of oxide selected from the group consisting of Ti, Zr, Nb, Al, and Si, or AlN and MgF, specifically at least one type selected from the group consisting of TiO2, ZrO2, Nb2O5, Al2O3, MgF, AlN, and SiO2. When the particles of the light-reflecting material are one type of oxide selected from the group consisting of Ti, Zr, Nb, and Al, the material can have high reflectivity and low absorption, and the refractive index difference with the base material, particularly the translucent resin, can be increased, which is preferable. The covering member 40 can also be made of a molded body made of the light-reflecting material, specifically, a porous material such as an aggregate or sintered body made by aggregating the particles, or a molded body made by a sol-gel method. This is preferable because it increases the difference in refractive index between the light-reflecting material and the air in the porous space, thereby increasing the light reflectivity, and because it can be made of an inorganic material. On the other hand, compared to a covering member having a base material such as the resin, it is possible to mold it into a desired shape, and the controllability of the covered area is good, and the sealing performance and airtight performance can be improved, so that the covering member having the base material is preferable in the present invention. In addition, taking into account the characteristics of both covering members, a composite molded body of both can be made, for example, a structure in which the outer surface side of the porous molded body is impregnated with resin and the inner surface side of the light-emitting element side is made porous. In this way, the covering member or the enclosure made of the covering member may be connected to the inside area and the outside, or may be gas-permeable, and may have a form in which at least light does not leak out.

[0035] In the covering member 40 containing the light-reflecting material 45 in the base material described above, the depth from which light leaks out varies depending on the content concentration and density, so it is advisable to adjust the concentration and density appropriately according to the shape and size of the light-emitting device. For example, when making the thickness of a relatively small light-emitting device small, it is preferable to provide a high-concentration light-reflecting material 45. On the other hand, the concentration is adjusted appropriately during the manufacturing process, such as preparation of the raw material for the covering member 40 containing the light-reflecting material 45, application of the raw material, and molding. The same applies to the porous body. As an example, in the case of the embodiment, it is preferable that the content concentration of the light-reflecting material 45 is 20 weight percent (wt%) or more and the thickness is 20 μm or more, and high-brightness and highly directional emitted light is obtained from the light-emitting surface 90, and the covering member has moderate viscosity, making it easy to form an underfill. In addition, if the concentration of the light-reflecting material is increased, the thermal diffusion of the covering member can be increased.

[0036] The formation region of the covering member is provided with the covering member 40 at least on the side surface of the light transmitting member 20, preferably covering the side surface of the light emitting element, more preferably exposing the light emitting surface in the light source unit including the light transmitting member and the light emitting element and covering the rest, and the same applies when the light guiding member 30 is used. This makes it possible to prevent light from leaking out from the side surface of the light transmitting member, suppressing light with a relatively high intensity from the side surface, and light with a color difference when a light converting member is included, improving the directivity of the emitted light, and reducing unevenness in brightness and color. In addition, by covering the side surface of each member and element and restricting it to the light extraction direction side, the directivity and brightness can be improved. In addition, when the light transmitting member 20 contains a wavelength conversion material, the heat generation of this wavelength conversion material is particularly significant, and this can be improved. As long as the side surface of the light transmitting member 20 is covered with the covering member 40 and the surface 21 is exposed, the outer surface shape is not particularly limited, and the exposed surface may be recessed from the surface 21 of the light transmitting member as shown in FIG. 1. The light-emitting surface 90 protrudes, so that light blocking by the covering member 40 can be avoided, and the surface may be substantially the same as desired. In the first embodiment, the covering member 40 also covers a part of the light-receiving surface 22, and covers the periphery of the light-emitting element 10, specifically, the area of ​​the light-receiving surface 22 of the light-transmitting member excluding the area facing the light-emitting element 10, as shown in the figure. With this configuration, as shown in FIG. 2, the light-receiving surface 22 is provided with an optical connection area (bonding area 31) and a covering area that is covered via the light-guiding member (covering areas 32, 33). In addition, the covering area reflects the light that has traveled toward the light-receiving surface 22 side of the light-transmitting member toward the light extraction side, and the optical loss of the primary light due to the optical absorption in the substrate 50 can be suppressed. As shown in FIGS. 5 and 8, when a plurality of light-emitting elements 10 are joined to one light-transmitting member 20, it is preferable that the covering member 40 is also filled between the light-emitting elements (second covering area 34) to cover the spaced areas of the light-receiving surface 22. This configuration can enhance the heat dissipation properties of the spaced apart region with respect to the heat of the light conversion member in the joint region, and is similarly preferable for the protrusion of the light transmitting member and the first covered region 32 as described above.

[0037] (Additives) In addition to the light-reflecting material 45 and the light-converting material, a viscosity enhancer and the like can be appropriately added to the covering member 40, thereby obtaining a light-emitting device with the desired luminescent color, the color of the members or the surface of the device, such as black for high contrast, and the desired directional characteristics. Similarly, various colorants can be added as filter materials to cut out unnecessary wavelengths. The same applies to other members, and light-transmitting materials such as light-guiding members, sealing members, and light-transmitting members.

[0038] (Light guiding components) The light guide member 30 is used as an adhesive interposed between the light emitting element 10 and the light transmitting member 20 to fix both members. This light guide member is preferably made of a material that has light transmissivity, can guide the emitted light of the light emitting element 10 to the light transmitting member side, and can optically couple both members. Examples of the material include the resin materials used for each of the above members, and light transmissive thermosetting resins such as silicone resin and epoxy resin are preferable, with silicone resin being preferable because of its excellent heat resistance and light resistance. In addition, if silicone resin is used, it is preferable because the effect of the fluorine-based mold release agent is high. Furthermore, if a dimethyl-based silicone resin is used, it is excellent in reliability such as high temperature resistance, and if a phenyl-based silicone resin is used, it is possible to increase the refractive index and increase the efficiency of extracting light from the light emitting element 10.

[0039] (Mounting board 50) On the other hand, in the light emitting device 100 of FIG. 1, the substrate 50 on which the light emitting element 10 is mounted can be one on which at least the surface is formed with wiring 51 connected to the electrode of the element, and wiring 52 for external connection may also be provided. The material of the substrate is, for example, aluminum nitride (AlN), and a single crystal, polycrystal, sintered substrate, other materials such as ceramics such as alumina, glass, semimetallic or metallic substrates such as Si, or laminates or composites thereof can be used, and metallic and ceramic substrates are preferable because of their high heat dissipation. The substrate 50 may not have wiring, and may be, for example, a form in which the growth substrate side of the element in FIG. 4 is mounted and the electrode of the element is wire-connected to the electrode of the device, or a form in which wiring is provided on the light transmitting member and connected. In addition to a form in which the covering member 40 is provided on the mounting substrate 50 as in the light emitting device shown in the figure, a form in which the outer side surface of the mounting substrate 50 is also covered may also be used. In addition, it is preferable that at least the surface of the mounting substrate 50 is made of a highly reflective material. 1 and 2, the light emitting element 10 is attached onto wiring 51 by a conductive adhesive 60, and is electrically connected to the outside. The conductive adhesive 60 may be solder, Ag paste, Au bumps, or the like.

[0040] (Frame, laminated board, base material) The light emitting device 100 shown in FIG. 1 has a frame body 55, which is a holding member for the covering member 40. The frame body 55 can be formed of ceramics, resin, or the like. Alumina, which has high light reflectivity, is preferable, but is not limited to this as long as a reflective film is formed on the surface. If it is a resin, screen printing or the like may be used, or a molded body may be bonded to a mounting substrate. Also, it is preferable to increase the reflectance by using a light reflective material, as with the covering member 40. Also, like the above-mentioned additive member, the frame body may be colored according to the purpose. Note that this frame body can be removed after the covering member is filled or molded. Also, the frame body may be formed integrally with the mounting substrate of the light emitting element, such as a laminated substrate 56, a device base having a cavity structure made of a base material, or the like.

[0041] (Method of manufacturing a light emitting device) An example of a manufacturing method of the light emitting device 100 shown in FIG. 1 will be described below. First, bumps 60 are formed on the mounting substrate 50 or the light emitting element 10, and flip chip mounting is performed. In this example, on the substrate 50 before singulation, one LED chip is mounted in a region corresponding to one light emitting device. Next, a light guide member 30 is applied to the emission surface side of the light emitting element 10 (the back surface of the sapphire substrate or the exposed surface of the nitride semiconductor if the substrate is removed by LLO), and the light transmitting member 20 is laminated, and the resin 30 is thermally cured and bonded. Next, a resin constituting the covering member 40 is potted by a dispenser (liquid constant quantity discharge device) or the like in a frame body 55 erected around the light emitting element 10 so as to cover the side surface of the light transmitting member 20. The dropped resin 40 creeps up and covers the side surfaces of the light emitting element 10 and the light transmitting member 20 due to surface tension, forming an inclined surface that is lower toward the frame body 55 than the surface 21. The exposed surface of resin 40 may be flattened to be approximately flush with surface 21. After resin 40 is cured, it is diced at predetermined positions and cut into a desired size to obtain light emitting device 100.

[0042] (Embodiment 2) Fig. 5(a) is a schematic cross-sectional view of a light-emitting device 200 according to a second embodiment of the present invention, and Fig. 5(b) is a schematic cross-sectional view for explaining the periphery of the light source unit. In the light-emitting device 200, the configuration other than the number of light-emitting elements 10 and the structure of the light-guiding member 30 is substantially similar to that of the first embodiment described above, and therefore the same components are denoted by the same reference numerals and the description thereof will be omitted as appropriate.

[0043] In the light emitting device of the present invention, the number of light emitting elements 10 bonded to one light transmitting member 20 is not particularly limited. By using a plurality of light emitting elements 10, as opposed to a single light emitting element in the first embodiment, the plurality of light emitting elements can be appropriately arranged in accordance with the size and shape of the light transmitting member and the light emitting surface, and can also be driven individually to obtain the desired light emitting characteristics, which is preferable because a light emitting surface with the desired shape and light emitting characteristics can be obtained. When a plurality of light emitting elements 10 are mounted, they are provided at an appropriate distance from each other, and this distance can be appropriately determined in consideration of the light distribution characteristics and heat dissipation properties of the light emitting device, as well as the mounting accuracy of the light emitting elements, and is, for example, within 10% of the dimensions of the light emitting elements. In addition, the plurality of light emitting elements 10 may be bonded to each other. In the present embodiment, two of the light emitting elements are arranged in a row, but this is not limited to this, and various arrangements such as a lattice arrangement, regular arrangement, irregular arrangement, etc. are possible, and it is preferable to arrange the elements at approximately equal intervals to reduce the intensity distribution.

[0044] In the light emitting device 200, a plurality of light emitting elements 10 (two in the figure) are mounted on a mounting substrate 50 with a space between them, and a light transmitting member 20 having a light receiving surface 22 large enough to encompass the plurality of light emitting elements 10 is joined onto the light transmitting member 20 via a light guiding member 30. In this light emitting device 200, the frame is laminated on the substrate 50 to form a base 56 having a cavity structure, and a wiring layer 51 for mounting elements on the upper surface side and a wiring layer 52 for external connection electrically connected thereto are also provided on the lower surface side of the base 56.

[0045] In such a light-emitting device 200, the bonding region 31 is provided in the opposing region between the light-receiving surface 22 of the light-transmitting member and the emission surface of each light-emitting element 10. The above-mentioned first covering region 32 is provided on the side surface facing the outside of the light-receiving surface of the light-emitting element 10 that is disposed on the outside of the light-receiving surface among the plurality of light-emitting elements, and covers the peripheral portion of the light-receiving surface 22 as a protruding surface, and a first reflecting surface 33 is provided on the outer surface thereof, so that light emitted laterally from the light-emitting element 10 can be reflected and guided to the light-receiving surface 22 side of the light-transmitting member. In this example, although not shown, a plurality of light-emitting elements are disposed at one end of the light-receiving surface, and a first covering region and a first reflecting surface are provided on the side surface of the end side, but they may be separated for each element. It is preferable that they are bonded to each other, and one first covering region and one first reflecting surface are common, and they are arranged close to each other to form the first covering region and the first reflecting surface. At this time, the first covering region may be provided with a recess between the elements.

[0046] In addition, when a plurality of light-emitting elements 10 are joined to the light-receiving surface 22 side of one light-transmitting member 20, the light-guiding member 30 also hangs down in the spaced region between adjacent light-emitting elements, that is, has a second covering region 34 extending from the joining region 31 to cover a part of the mutually facing side surfaces of the adjacent light-emitting elements 10 and a part of the light-receiving surface 22 sandwiched between the elements. This second covering region 34 is usually provided so as to connect the mutually facing side surfaces of the adjacent light-emitting elements 10. In addition, the outer surface of this second covering region 34 is also located on the light-transmitting member 20 side from the mounting surface of the light-emitting element 10, that is, the light-guiding member is separated from the mounting substrate, so that it is possible to prevent the light from being guided to the substrate 50, leaking, and being absorbed. And, a second reflecting surface 35 that reflects the light emitted from the light-emitting element 10 to the light-receiving surface 22 side is provided on the outer surface of this second covering region 34. Thus, in a light emitting device in which a plurality of light emitting elements 10 are mounted on the light receiving surface 22 of one light transmitting member 20, the second reflecting surface 35 of the light guiding member 30 can effectively extract light emitted from the plurality of light emitting elements 10 to the side and to the spaced apart regions, and can reflect the light toward the light receiving surface 22 of the light transmitting member to be optically coupled to the light transmitting member 20. It is also preferable that the second reflecting surface 35 also has an inclined surface similar to the first reflecting surface in the light emitting device 100 of the first embodiment. In particular, as shown in the figure, it is preferable that there is one convex curved surface between the elements, because the emitted light from each element can be effectively reflected in the spaced apart regions to be mixed with each other.

[0047] It is preferable that the second reflecting surface 35 is provided farther from the light receiving surface 22 of the light transmitting member than the emission surfaces of the light emitting elements 10. As a result, when the reflecting surface 35 or the tip of the convex curved surface is provided closer to the light receiving surface than the emission surface as shown in FIG. 8 (Embodiment 5), the emitted light of each light emitting element 10 can be diffused and guided widely compared to the case where it is provided between the emission surface and the light receiving surface, and the decrease in the luminous flux in the spaced area can be reduced, and therefore the luminance unevenness and chromaticity unevenness caused by the arrangement of each light emitting element 10 and its light distribution can be reduced, and the luminance in the light emitting surface can be made uniform. On the other hand, in the former case as shown in FIG. 8, although it is easy to separate each light emitting element and the luminance unevenness becomes large, the light extraction efficiency can be increased, which is preferable when utilizing it.

[0048] In addition, it is preferable that at least one set of the multiple light-emitting elements 10 has a different height of the emission surface due to mounting misalignment or the like, and a light-guiding member is interposed between the light-emitting elements 10 so that the distances from the emission surfaces of the light-emitting elements 10 to the light-receiving surface 22 of the light-transmitting member are different from one another. This reduces the incidence of light from one light-emitting element 10 to its adjacent light-emitting element 10, and suppresses the loss of light flux due to light absorption within the light-emitting element 10. This form can be adjusted by the thickness of the conductive adhesive 60 that bonds the light-emitting element 10 to the mounting substrate 50, etc.

[0049] The second reflecting surface 35 is preferably provided at the interface between the light guide member 30 and the covering member 40 sandwiched between the adjacent light emitting elements 10, similarly to the first reflecting surface. In the spaced region between the adjacent light emitting elements, a metal film such as wiring is not formed on the mounting substrate 50 and the substrate surface is often exposed, which is likely to cause light absorption. Therefore, it is preferable that at least the surface of this substrate is covered with a covering member, and it is more preferable that the covering member 40 is filled and the second reflecting surface 35 is provided at the interface with the covering member 40. In addition, as described above, a form in which a gap is provided between the covering member 40 filled in the spaced region and the second reflecting surface 35 may be used.

[0050] (Embodiment 3) FIG. 6 is a schematic cross-sectional view illustrating the periphery of the light source unit of the light-emitting device according to the third embodiment of the present invention. In this light-emitting device, the configuration other than the size relationship between the light-emitting element 10 and the light-transmitting member 20 and the structure of the light-guiding member 30 is the same as that of the first embodiment described above, and therefore the same configurations are given the same reference numerals and the description is omitted as appropriate. In the light-emitting device of the example shown in FIG. 6, the light-receiving surface 22 of the light-transmitting member is smaller than the emission surface of the light-emitting element 10, and a part of the emission surface protrudes outward from the light-receiving surface 22. In other words, the side surface of the light-transmitting member 20 is located inside the side surface of the light-emitting element 10. Such a light-emitting device can increase the brightness of the emitted light by using the light-emitting surface 90 of the light-emitting device as a relatively small light-emitting window. That is, unlike the first and second embodiments described above, the light-guiding member extends to the protruding surface of the light-emitting element and the side surface of the light-transmitting member provided inside the protruding end, covering the area.

[0051] In the light emitting device of this embodiment, the light guide member 30 has a bonding region 31 that bonds the region of the emission surface of the light emitting element 10 facing the light transmitting member and the light receiving surface 22 of the light transmitting member. The light guide member 30 also has a first covering region 32 that extends from the bonding region 31, creeps up to the side surface of the light transmitting member 20, and covers the side surface of the light transmitting member 20. The first covering region 32 that covers the side surface of the light transmitting member 20 can reflect and collect the emitted light of the light emitting element 10, and can particularly reflect the light at its end to guide the light to the light transmitting member 20 side. In addition, the outer surface of the first covering region 32 is also located closer to the light transmitting member 20 side than the mounting surface of the light emitting element 10, thereby preventing light from leaking to the mounting board 50. Here, the outer surface of the first covered region 32 facing the covering member 40, i.e., the outer surface of the first covered region 32 facing the side surface of the light transmitting member, has a first reflecting surface 33 that reflects the light emitted from the light emitting element 10 toward the light transmitting member 20. Therefore, the light transmitted through the first covered region 32 is reflected toward the light transmitting member 20 by the first reflecting surface 33, and the reflected light is optically coupled to the light transmitting member 20 and emitted from the light emitting surface 90 to the outside of the device. In this way, the light emitted from the light emitting element 10 toward the light receiving surface 22 of the light transmitting member is efficiently optically coupled to the light transmitting member, thereby improving the utilization efficiency of the light emitted from the light emitting element 10.

[0052] The first reflecting surface 33 in the light emitting device of this embodiment may have the same interface configuration as the first reflecting surface 33 in the light emitting device 100 of the first and second embodiments, and is preferably provided at the interface with the covering member 40 in the same manner. In addition, since the outer surface of the first covering region 32 facing the side surface of the light transmitting member 20 is an inclined surface inclined from the side surface toward the emission surface side of the light emitting element 10, the first reflecting surface 33 is also an inclined surface inclined in the same manner, which is preferable because it can reflect light favorably toward the light transmitting member 20 side. Furthermore, this inclined surface may be a flat surface, but is preferably a convex curved surface convex toward the bonding region 31 as described above, which can increase the surface area of ​​the first reflecting surface 33 and improve the light reflection efficiency.

[0053] On the other hand, in the light-emitting device of the example shown in FIG. 6, the side of the light-emitting element 10 is exposed from the light-guiding member 30, and is preferably covered with a light-reflective covering member 40. In this way, the outer surface of the light-guiding member 30 is provided so as to connect the emission surface of the light-emitting element 10 and the side of the light-transmitting member 20, so that the outward bulging of the outer surface of the light-guiding member 30 can be suppressed compared to the case where the light-guiding member 30 also covers the side of the light-emitting element 10. Therefore, the optical path length of the light reflected on the outer surface of the light-guiding member 30 to the light-transmitting member 20 can be shortened, the light absorption in the light-guiding member 30 can be reduced, and the optical coupling efficiency to the light-transmitting member 20 can be improved. In addition, it becomes easier to form the first reflecting surface 33 having a shape and an inclination angle suitable for light reflection toward the light-transmitting member 20 side, and the reflection efficiency by the first reflecting surface 33 can be improved.

[0054] (Embodiment 4) FIG. 7 is a schematic cross-sectional view illustrating the periphery of the light source unit of the light-emitting device according to the fourth embodiment of the present invention. In the example shown in FIG. 7, the configuration other than the form of the light-guiding member 30 and the shape of the surface 21 of the light-transmitting member is substantially the same as that of the first embodiment described above, and therefore the same configurations are given the same reference numerals and the description thereof is omitted as appropriate. In the light-emitting device of the example shown in FIG. 7, the light-receiving surface 22 of the light-transmitting member is larger than the emission surface of the light-emitting element 10, and a part of the light-receiving surface 22 protrudes outward from the emission surface of the light-emitting element 10. The light-guiding member 30 has a bonding region 31 that bonds the region of the light-receiving surface 22 of the light-transmitting member facing the light-emitting element and the emission surface of the light-emitting element 10, and also has a third covering region 37 that extends from the bonding region 31 to cover the light-receiving surface 22 of the protruding portion of the light-transmitting member 20 and has an outer surface on the light-transmitting member 20 side from the mounting surface of the light-emitting element 10. The side surface of the light-emitting element 10 and the side surface of the light-transmitting member 20 are exposed from the light-guiding member 30. The outer surface of the third covered region 37 has a third reflecting surface 38 that reflects the light emitted from the light-emitting element 10 toward the light-receiving surface 22 of the light-transmitting member 20. Here, the third covered region and the third reflecting surface are one form of the above-mentioned first covered region and first reflecting surface, respectively.

[0055] The outer surface of the third covering region 37 is preferably an inclined surface inclined from the end of the emission surface of the light-emitting element 10 toward the light-receiving surface 22 of the protruding portion of the light-transmitting member 20. As a result, the third reflecting surface 38 becomes an inclined surface inclined from the end of the emission surface of the light-emitting element 10 toward the light-receiving surface 22 of the protruding portion of the light-transmitting member 20, and the emitted light of the light-emitting element 10, the reflected light from the light-transmitting member, and the emitted light can be well reflected toward the light-receiving surface 22 of the light-transmitting member. Furthermore, this inclined surface may be a flat surface, but it is preferable that it is a convex curved surface that is convex toward the bonding region 31, since the surface area of ​​the third reflecting surface 38 can be increased compared to the case where it is a flat surface, and the light reflection efficiency can be improved. In addition, the third reflecting surface 38 is preferably provided at the interface with the covering member 40, as with the first reflecting surface 33 in the first embodiment, but it may be separated from the covering member 40 by a gap, or it may be formed by providing a metal film or a dielectric multilayer film.

[0056] By bonding the light emitting element 10 and the light transmitting member 20 with such a light guiding member 30, the emitted light of the light emitting element 10 can be suitably coupled, and the luminance and chromaticity distribution in the light emitting surface can be made uniform, compared with the case where the light emitting element 10 and the light transmitting member 20 are bonded only at the bonding region 31. The light guiding function of such a light guiding member 30 depends on the protruding length of the side surface of the light emitting element 10 relative to the side surface of the light transmitting member 20, so it is preferable to set it to the above-mentioned range, for example. The covering form of such a light guiding member 30 can be achieved by appropriately adjusting the amount, protruding width, and surface area of ​​the light guiding member, and can also be achieved by applying a release agent to almost the entire side surface of the light emitting element 10 to prevent the light guiding member 30 from sagging to the side surface of the light emitting element 10. A release agent may also be applied to the side surface of the light transmitting member 20, and the light guiding member 30 can be manufactured with high accuracy. In this example, the side of the light-emitting element is exposed, and the side is not covered as in the first and second embodiments, so that the return light and the converted light can be suppressed from being re-entered into the element by the light-guiding member, that is, the contact area between the light-guiding member and the light-emitting element can be minimized, and the coupling efficiency can be improved. In addition, in the example shown in FIG. 7, the surface 23 of the light-transmitting member is an uneven surface, and the light transmitted through the light-transmitting member 20 is scattered by the unevenness, so that the light extraction efficiency from the light-transmitting member 20 can be improved, and the luminance unevenness and color unevenness can be reduced, and uniform light distribution can be achieved. In particular, when multiple light-emitting elements 10 are mounted, it is preferable because the luminance unevenness and color unevenness caused by this can be reduced. Such unevenness can be formed on the surface of the light-transmitting member by processing such as polishing, dry etching, and wet etching, and in addition to an irregular uneven structure, a regular pattern uneven structure can also be formed. Furthermore, similar effects can be obtained by providing such an uneven structure not only on the surface of the light-transmitting member, but also on the light-receiving surface and even on the surface of each component on the optical path, and in particular, it may be provided on the interface with the light-guiding member or the surface of a component in contact with it, for example, the surface of substrate 1 on the semiconductor layer 11 side, and although not described in detail in the examples, such a structure is used.

[0057] (Modification) In the above-mentioned first to fourth embodiments, the case where either one of the light-emitting element and the light-transmitting member is contained in the other, that is, inside the other, has been described. However, the relationship between the light-emitting element and the light-transmitting member in the light-emitting device of the present invention is not limited to this form, and one may have at least a part of a protruding portion protruding outward from the other. For example, one of the side surfaces constituting the light-emitting element, or a part of one side surface, may protrude outward from the side surface constituting the light-transmitting member, and the other side surfaces may be approximately flush with each other, or the light-transmitting member may protrude, or vice versa. In such a form, the first covering region is provided on the protruding side surface or a part of the side surface. Also, in a top view, a protruding portion may be provided on both sides of either one of the light-emitting element and the light-transmitting member. In such a form, at least one of the first covering regions 32 described in the first and second embodiments is provided in the cross section of the region having the protruding portion. Also, when there are a plurality of light-emitting elements, the first covering region may be provided on the light-emitting element and the light-transmitting member in each element, and they may be mixed. Preferably, the first covering region is provided on either one of the light guiding members, i.e., either of the first and third embodiments, and some of the side surfaces may be substantially the same. More preferably, the first covering region is unified between the light emitting element and the entire outer periphery of the light transmitting member in either form. This is because it is possible to reduce unevenness in brightness and chromaticity in the light emitting surface, and it is most preferable that either one of the side surfaces of the light emitting element and the light transmitting member is included inside the other.

[0058] As described above, the light guide member of the present invention is provided between the light emitting element and the surface of the light transmitting member, and optically couples the two to form a composite light source. Between the element and the member, a joint region where they face each other, and the first covering region that extends from the joint region and covers one protruding surface or the other end face provided inside the protruding surface and the end face are provided. Specifically, the light guide member uses a resin material and is also used as an adhesive, so as described above, by providing a protruding surface, the material may wet and spread from the joint region to the surface, and may also wet and spread from the protruding surface to the side surface that is the other end. In this way, the light guide member utilizes the wetting of the resin on each surface during its production, specifically before the resin hardens, so first, the amount of the material and the application method thereof, and the protruding width and area of ​​the protruding surface are controlled, and in addition, the spread to other regions can be controlled by using a release agent. Therefore, as a specific embodiment of the light guide member, it is preferable that the thickness in the joint region is smaller than that of the light transmitting member and further smaller than that of the growth substrate, so as to reduce the size of the composite light source and increase its coupling efficiency. In addition, the protruding width at that time is about 0.25 to 5 times the thickness of the light emitting element or the light transmitting member, so that control during manufacturing is easy and light from the element can be diffused and collected appropriately. As described above, as shown in the first and third embodiments, when covering one end from one protruding portion to the other end, it is preferable that the end on the protruding portion side is exposed, which is preferable because it can suppress the spread of the light source and improve each characteristic of the present invention compared to the case where it is covered. In addition, when covering, if the thickness is thinner than that of the other end, the influence can be reduced, and the same effect as that of the covering member described later can be expected, which is preferable.

[0059] As described above, the covering area of ​​the protruding surface is preferably thinner than the bonding area as shown in FIG. 7, but the effect of the present invention can be expected even if the side of the element is exposed by performing a release treatment and made thicker. As seen in the first and third embodiments, various characteristics are affected by the covering area of ​​the side of the element, but when a light-transmitting substrate 1 made of a different material from the semiconductor layer 11 is included, the function of the light-transmitting member can be supported as a light propagation region between the light-transmitting member and the element, similar to the light-guiding member, by covering the substrate, which is preferable. In particular, in the case of a light conversion member, the converted light component is also included in the region, which is effective in reducing chromaticity unevenness and orientation. In addition, in an element from which the substrate 1 has been removed, the light component from the emission surface becomes much more than the side, so the side of the element may be exposed. As described above, the covering member can support the functions of the light-guiding member in the light confinement to the composite light source, the light emission from the light-emitting surface, and the coupling thereof, but a reflective film such as a metal film or a dielectric multilayer film can also be used instead. In the case of a light reflecting material as in the embodiment, the light seeps into the substrate, so the light from the light source spreads more than inside the coating, which increases the efficiency of light diffusion and light collection, and further contributes synergistically to the light emitting characteristics, brightness unevenness, and directivity, particularly to the function of the light guide member, which is preferable. Also, in the case of a light conversion member, it is preferable because it contributes favorably to color unevenness and orientation, and further, by covering the side surface, it is preferable to suppress the relatively high side emission, which is different from the surface 21 in color and wavelength component ratio.

[0060] In addition, either the light emitting element 10 or the light transmitting members 20, 24, whichever has a protruding portion, may not have a clear boundary between the surface facing the other member and the side surface continuing from said surface. For example, in the light emitting device 100 of the first embodiment, the light receiving surface 22 and the side surface of the light transmitting member 20 may be integrated to form a single curved surface, for example, a spherical surface or a part thereof. Furthermore, the light receiving surface 22 of the light transmitting member and the emission surface of the light emitting element 10 may be directly bonded by crystal bonding using thermocompression bonding or the like to form a light guide member 30 having a first covering region on the protruding portion and, when a plurality of light emitting elements are provided, a second covering region between the elements.

[0061] (Embodiment 5) FIG. 8 is a schematic cross-sectional view of a light-emitting device 300 according to a fifth embodiment of the present invention. In the light-emitting device 300, the same components as those in the first to fourth embodiments are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. In the example shown in FIG. 8, the light-emitting element 10 and the light-transmitting member 20 are covered with a covering member 40 containing a light-reflective material 45 to form a surface-emitting light source having the surface 21 of the light-transmitting member 20 as the light-emitting surface, and a sealing member 80 is provided to cover the light source and further cover a part of the covering member, forming a hemispherical optical lens. In this light-emitting device 300, a plurality of light-emitting elements 10 (two in the figure) are flip-chip mounted on the wiring pattern 51 on the upper surface side of the mounting board 50, and one light-transmitting member 20 is bonded thereon by a light-guiding member 30. In this example, the covering member 40 of the frame body shown in the first embodiment is removed after molding, and the side surface of the covering member 40 is exposed to the outside to form the outer surface of the light-emitting device. The width of the cross section of the light receiving surface 22 of the light transmitting member is smaller than the distance between the outer side surfaces of the outermost light emitting elements 10, in other words, smaller than the width of the region in which the multiple light emitting elements are provided. The side surfaces of the outermost light emitting elements 10 protrude outward beyond the side surfaces of the light transmitting member 20. The light guiding member 30 has a second covering region and a second reflecting surface 35 similar to those of the second embodiment in a spaced region sandwiched between adjacent light emitting elements, and has a first covering region and a first reflecting surface 33 similar to those of the third embodiment in a region connecting the side surfaces of the light transmitting member 20 and the protruding portions of the emission surfaces of the outermost light emitting elements 10.

[0062] According to the configuration of the light emitting device 300, the first and second covering regions and the first and second reflecting surfaces 33, 35 of the light guide member 30 can efficiently couple the light emitted from the light emitting element 10 to the light transmitting member 20, and can efficiently extract the light from the light transmitting member 20 to the sealing member 80, resulting in a light emitting device with higher output. Furthermore, the optical lens 80 exaggerates or changes the emitted light due to the light distribution characteristics on the surface 21 of the light transmitting member, but the light guide member 30 of the present invention can uniformize the unevenness of the brightness and chromaticity of the light, resulting in a light emitting device with excellent light distribution characteristics. Furthermore, the sealing member 80 continuously covers the surface 21 of the light transmitting member and a part of the surface of the covering member 40, and the light of the sealing member 80 can be reflected by the surface of the covering member 40 and efficiently extracted to the outside, and the light emitting side surface of the covering member 40 is made a concave surface inclined from the side surface of the light transmitting member 20 toward the substrate 50, so that the light is diffused and the emitted light of the light emitting device can be widely oriented. In this way, the light emitting device of the present invention can have desired light emitting characteristics by bonding an optical member to the surface of the light transmitting member of the light emitting surface.

[0063] (Sealing member) Here, if the sealing member 80 has a lower refractive index than the light-transmitting member, it can be bonded to the surface 21 of the light-transmitting member to improve the light extraction efficiency. The surface on the light-emitting side of the sealing member 80 can be formed into various shapes depending on the purpose. For example, as shown in FIG. 8, by making the surface on the light-emitting side a spherical (semispherical) lens shape or a convex curved surface, the light emitted from the light-transmitting member can be efficiently extracted to the outside. In addition, the present invention is not limited to this, and various optical elements and optical members of desired shapes can be used, and the shape can be a concave lens shape, a parabolic surface, or a convex shape with a flat tip, or the light can be scattered as an uneven surface.

[0064] The sealing member 80 can be formed using a resin material such as epoxy resin, silicone resin, modified silicone resin, urea resin, urethane resin, acrylic resin, polycarbonate resin, polyimide resin, etc., in the same manner as the base material of the covering member 30 and the light guide member described above. In addition, since the sealing member 80 also serves as a sealing material to protect the light emitting element 10 and the light transmitting member 20, a material having excellent weather resistance, heat resistance, and hardness is preferable, and among the above, epoxy resin or hard silicone resin is preferable. In addition, glass may be used. Furthermore, the above-mentioned phosphor, and / or light scattering particles such as TiO2, and / or filler such as quartz glass can be appropriately added to the sealing member 80. The sealing member 80 is formed by compression molding, transfer molding, etc.

[0065] (Embodiment 6) FIG. 9 is a schematic cross-sectional view of a light-emitting device 400 according to a sixth embodiment of the present invention. The same reference numerals are used for the substantially same components as those in the first and second embodiments, and the description thereof will be omitted as appropriate. In the light-emitting device 400 of the example shown in FIG. 9, the light-emitting element 10 is flip-chip mounted at approximately the center of the bottom of a mounting base (package) 56 having a recess. The mounting portion is a part of the mounting base 56, but may be a submount. The light-transmitting member 24 is placed and bonded on the light-emitting element 10 via the light-guiding member 30. The recess is filled with a sealing member 84, and the recess is closed by a light-converting member 81 having a surface that becomes the light-emitting surface 82 of the light-emitting device 400. The light-transmitting member 24 and the light-converting member 81 can be configured in the same manner as the above-mentioned light-transmitting member and the above-mentioned light-transmitting member 20, respectively, containing a wavelength conversion material, and the sealing member can also be configured in the same manner as in the fifth embodiment, for example, made of a light-transmitting resin. In particular, in this example, the light transmitting member 24 may not contain a wavelength conversion material, and may be an optical element capable of collecting and diffusing light, other than a plate-like member as shown in the figure, or may be mixed with a light scattering material. Also, a reflective film having a concave curved surface is provided so as to cover the inner surface of the recess and the side surface of the protruding portion of the mounting portion, and can reflect and collect light toward each member 24, 84. Here, this reflective film is formed by the covering member 41 containing the above-mentioned light reflective material 46, and the above-mentioned resin creeps up to form a concave curved reflective surface. Note that the covering member 41 may have a highly reflective metal film such as Ag or Al formed on its surface as a substitute for the covering member 41, or may have a light conversion member containing a phosphor as described above, or may have no covering member and may have a form in which the inner surface of the mounting base is the reflective surface as in the conventional case. Also, the inside of the recess may contain a light conversion member in the sealing member 84, may be airtightly sealed, or may be the atmosphere, and the above-mentioned member 81 may be a member that does not contain a light conversion member, like the member 24. That is, a light emitting device can be made by providing a light conversion member in any of the members 24, 41, 81, and 84 to contain converted light, or a light emitting device can be made that does not include any of the members and extracts light emitted from the light emitting element.

[0066] In the light emitting device 400, as in the second embodiment, the light guide member 30 has the above-mentioned bonding region 31, the first covering region, and the first reflecting surface 33, and the recess is filled with the sealing member 84, so that the outer surface of the first covering region forms an interface with the light-transmitting sealing member, and the first reflecting surface 33 is provided at that interface. In other words, if a refractive index difference is provided between the light guide member and the sealing member, the interface reflection can be utilized, and if the first covering region side has a high refractive index, the reflectance can be increased, which is preferable, and the same is true for the case of airtight sealing. Light is emitted from the light emitting element 10 after being diffused in all directions, but some of the light components are reflected by the inner surface of the first reflecting surface 33 toward the light receiving surface 26 of the light transmitting member 24 and emitted from the light emitting surface 25, and some of the light components are reflected by the recess, The light can be extracted from the light-transmitting member 81. Therefore, the light from the light-emitting element 10 is collected by the light-transmitting member 24 and emitted from the surface 25, increasing the brightness in the front direction, that is, the light-emitting surface 82, and suppressing the diffusion of light within the recessed portion, thereby reducing light absorption. The same is true for the second reflecting surface 35 and its second covering region.

[0067] Furthermore, in the case of the fourth embodiment in which the light emitting element 10 is not covered by the light reflective covering member 40, the coverage of the first and second covering regions provided on the side surface of the light emitting element 10 is preferably the same as that of the first embodiment or wider than that of the first embodiment. If the coverage of the side surface of the light emitting element 10 by the light guide member 30 is wider, the efficiency of extracting light from the light emitting element 10 into the light guide member 30 can be improved, and the surface areas of the first and second reflecting surfaces 33 and 35 can be increased, thereby improving the coupling efficiency of light to the light transmitting member 20. However, as described above, in order to avoid light loss due to light absorption in the mounting base 56, it is preferable that the light guide member 30 has an outer surface located on the light transmitting member 20 side from the mounting surface of the light emitting element 10 and is spaced from the surface of the mounting base 56.

[0068] Examples of the present invention will be described in detail below. It should be noted that the present invention is not limited to the following examples.

[0069] Example 1 As shown in FIG. 5, the light source unit of the light emitting device of Example 1 has two roughly square LED chips of about 1 mm × 1 mm (having a structure in which nitride semiconductors 11 are laminated on a sapphire substrate 10 and having an emission wavelength of 455 nm) flip-chip mounted as light emitting elements 10 on wiring 51 of an AlN ceramic substrate 50, and one sintered body of YAG and alumina (Al2O3) is placed on top of the LED chips as a plate-shaped light conversion member or light transmitting member 20, the outer shape of which is roughly rectangular and measures about 1.1 mm × 2.2 mm, and the thickness of which is about 150 μm, and these are joined together by a light guiding member 30. At this time, an appropriate amount of silicone resin that will become the light guide member 30 is applied with tweezers onto the emission surface of each LED (the back surface of the substrate 1), the light transmitting member 20 is placed on top of it with tweezers, and draped over a portion of the side surface of the light emitting element 10. The resin is thermally cured for 60 minutes in an oven at 150°C, and the two LEDs are bonded so as to be enclosed within the light receiving surface of the light transmitting member as shown in the figure. In this way, the light guide member 30 is formed with a bonding region 31 between the LED and the light transmitting member, a first covering region 32 that covers the outer side surface of the LED light source, and a second covering region 34 that covers the inner side surface between the LEDs, and at this time, the light guide member is formed on the LED side surface, the substrate, and part or almost all of the semiconductor layer 11. Then, as shown in Fig. 1, an LED is mounted on the wiring 51 of the substrate 50, the cover member 40 is filled into the recess inside the frame surrounding the light emitting element 10 and the light transmitting member 20, and the light emitting element 10 and the light transmitting member 20 are encapsulated by the cover member 40 with the surface 21 of the light transmitting member 20 exposed as the light emitting surface, and the frame is removed as shown in Fig. 8 to obtain a light emitting device. Here, the cover member 40 is a silicone resin containing a light reflective material 45, which is TiO2 fine particles with a particle diameter of about 270 nm, at a concentration of about 23 weight percent. When driven with a current of 350 mA, the light emitting device of this Example 1 has a luminous flux of about 167 [lm] (chromaticity y value of about 0.339) and a maximum luminance of 6086 [cd / cm 2 ], average luminance 3524 [cd / cm 2 ], resulting in high luminous flux and high brightness.

[0070] Example 2 The light emitting device of Example 2, as shown in FIG. 6, has a form in which the light receiving surface of one light transmitting member is included in the emission surface of one light emitting element, and the light emitting element in Example 1 is one LED chip 10 having a substantially rectangular shape of about 1 mm×6.5 mm with six element structures provided on one sapphire substrate, and the light transmitting member 20 is further made to have a substantially rectangular shape of about 0.8 mm×6.3 mm, and the light emitting device is manufactured in the same manner as in Example 1. When the light transmitting member 20 is placed, it is lightly pressed to make the light guide member 30 creep up onto a part of the side surface of the light transmitting member 20, forming a first covering region 32. When driven with a current of 700 mA, the light emitting device of Example 2 has a luminous flux of about 740 [lm] (chromaticity y value of about 0.280) and a maximum luminance of 4629 [cd / cm 2 ], average luminance 4123 [cd / cm 2 ], resulting in high luminous flux and high brightness. [Industrial Applicability]

[0071] The light emitting device of the present invention can be suitably used as a light source for illumination, a backlight source for LED displays, liquid crystal display devices and the like, a traffic signal, an illuminated switch, various sensors, various indicators, and the like. [Explanation of symbols]

[0072] 10...light-emitting element (1...growth substrate, 2...first conductive type (n-type) semiconductor layer, 3...active layer, 4...second conductive type (p-type) semiconductor layer, 5...translucent conductive layer, 6...second electrode (p-side pad electrode), 7...first electrode (n-side pad electrode), 8...protective film, 11...element structure) 20, 24... Light-transmitting member (21, 23, 25... surface, 22, 26... light-receiving surface) 30...light guide member (31...joint region, 32...first covering region, 33...first reflecting surface, 34...second covering region, 35...second reflecting surface, 37...third covering region, 38...third reflecting surface), 40, 41...covering member, 45, 46...light reflective material 50... mounting board (51, 52... wiring, 55... frame, 56... laminated board or base material), 60... conductive adhesive

Claims

1. A light emitting element having an emission surface; a light transmitting member including the light exit surface and having a light receiving surface disposed opposite the light exit surface; a light guide member arranged in a region where the emission surface of the light emitting element and the light receiving surface of the light transmitting member face each other so as to join the emission surface of the light emitting element and the light receiving surface of the light transmitting member; A substrate having wiring on which the light-emitting element is mounted; A covering member having a light reflecting material is provided, the light guide member covers a light receiving surface of the light transmitting member located outside the region and a side surface of the light emitting element, and is spaced apart from a surface of the substrate; The covering member covers a side surface of the light emitting element via the light guiding member.

2. 2. The light emitting device of claim 1, wherein the region has a thickness of 0.01 μm to 100 μm.

3. 3. The light emitting device according to claim 1, further comprising a wavelength conversion member that is excited by light emitted from the light emitting element and is provided between the light transmitting member and the light emitting element.

4. the light transmitting member is a glass plate, The light emitting device according to claim 3 , wherein the wavelength conversion member is a light conversion member provided on the glass plate.

5. 3. The light emitting device according to claim 1, wherein the light transmitting member is a sintered body of a phosphor and an inorganic material.

6. The light emitting device according to claim 1 , wherein the substrate further comprises a frame surrounding the light emitting element.

7. The light emitting device according to claim 6 , wherein the frame is integrally formed with the substrate.

8. The light emitting device according to claim 1 , wherein the light guiding member contains a silicone resin.

9. The coating member includes a resin material, The light emitting device according to claim 1 , wherein a surface of the covering member includes a concave curved surface.

10. The light emitting device according to claim 9 , wherein the resin material includes a silicone resin.

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