JP5678462B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light-emitting device that enables light emission of different colors by mixing light emitted from a light-emitting element with original light even after wavelength conversion.

  A semiconductor light emitting element such as a light emitting diode is small in size, has high power efficiency, and emits bright colors. In addition, the semiconductor light emitting device has the characteristics that there is no fear of a broken ball, etc., excellent initial drive characteristics, and resistance to vibration and repeated on / off lighting. In addition, a light-emitting device that can emit light of various colors based on the principle of light color mixing is developed by combining light emission of a semiconductor light-emitting element and a wavelength conversion member that can emit light of different wavelengths when excited by this. Has been. Such light emitting devices are used as various light sources. In particular, in recent years, it has attracted attention as a next-generation illumination with low power consumption and long life replacing fluorescent lamps, and further improvements in light emission output and light emission efficiency are required. In addition, there is a demand for a high-luminance light source such as a projector such as a car headlight and a floodlight.

  Regarding such a light emitting device, Patent Document 1 proposes a structure shown in FIGS. 5 (a) and 5 (b). A light emitting semiconductor chip assembly 72 shown in FIG. 5A is configured by fixing a light emitting diode chip 78 on a phosphor chip 74 via a transparent adhesive 76. The phosphor chip 74 has a phosphor layer 82 on a substrate 80 made of a transparent material such as silica or alumina or an opaque material having good light reflectivity. FIG. 5B shows a cross-sectional view of a light emitting device 92 configured using the light emitting semiconductor chip assembly 72. The light emitting device 92 includes an anode lead 88 and a cathode lead 90, and a light emitting semiconductor chip assembly 72 is fixed to a cup portion 90 a provided at the tip of the cathode lead 90. The anode electrode 84 and the cathode electrode 86 of the light emitting semiconductor chip assembly 72 are connected to the anode lead 88 and the cathode lead 90, respectively. The periphery of the light emitting semiconductor chip assembly 72 is covered with a protective adhesive 96 in which a light scattering agent 94 is dispersed.

JP 2002-141559 A

  According to the light emitting device shown in FIGS. 5A and 5B, since the phosphor chip 74 is fixed to the back surface of the light emitting diode chip 78, the back surface of the light emitting diode chip 78 is connected to the cup portion 90a of the cathode lead. The light output is increased compared to a structure that directly bonds. This is due to the following reason. When the back surface of the light emitting diode chip 78 is directly bonded to the cup portion 90a of the cathode lead with silver paste or the like, light emitted from the back surface of the light emitting diode chip 78 is reflected by the silver paste, but the silver paste has a reflectivity. Since it is not high, light output will fall. By adhering the phosphor chip 74 to the back surface of the light emitting diode chip 78, light emitted from the back surface of the light emitting diode chip 78 is extracted to the outside through the phosphor layer 82 that is in direct contact with the light emitting diode chip 78. improves. In addition, due to the effect of the light scattering agent 94 dispersed in the protective adhesive 96, the light emission of the light emitting diode chip 78 and the phosphor chip 74 is mixed and color unevenness is suppressed.

  However, such a conventional light emitting device has a problem that it is difficult to obtain a light emitting device that sufficiently satisfies both color unevenness and light emission output. That is, in order to sufficiently suppress the color unevenness by mixing the light emission of the light emitting diode chip 78 and the phosphor chip 74, it is necessary to disperse the light scattering agent 94 in a certain amount. However, if the light scattering agent 94 is dispersed in a large amount around the light emitting diode chip 78, the light scattered by the light scattering agent 94 easily returns to the inside of the light emitting diode chip 78. The proportion of absorbed light will increase. Accordingly, when the amount of the light scattering agent 94 is increased in order to improve the color unevenness, the light emission output is lowered, and when the amount of the light scattering agent 94 is decreased in order to increase the light emission output, the color unevenness is deteriorated.

  Accordingly, an object of the present invention is to provide a new light-emitting device that can simultaneously improve both color unevenness and light-emission output.

In order to achieve the above object, a light-emitting device of the present invention includes a container having a recess having an upper surface opened, a light-emitting element disposed inside the recess and having a light-emitting layer made of a semiconductor, and the light-emitting element. A support member made of a translucent material to be supported, and disposed inside the recess, between the light emitting element and the upper surface of the recess, and absorbs part of the light emitted from the light emitting element to emit light of different wavelengths. A light-emitting device that includes a wavelength conversion member that emits light and a translucent member that covers an upper surface of the recess, and that emits light from the light-emitting element and light emitted from the wavelength conversion member and emits the light from the upper surface of the recess. The concave portion has a scattering surface capable of scattering light emitted from the light emitting element and light emitted from the wavelength converting member on at least a part of a side surface thereof, and the light emitting element and the wavelength converting member are Apart from the side, said Side light element is exposed from the wavelength conversion member, wherein the wavelength conversion member, at least, apart from the light emitting element is disposed in the middle of the path toward the upper surface of the recess from the light emitting element, and The translucent member is fixed to the light emitting element side, and the surface of the translucent member on the light emitting element side has a critical angle θ _C between the center of the light emitting layer of the light emitting element and the upper end of the recess. It is arranged so as to be smaller than an angle β formed by the connecting line and the optical axis of the recess, and the surface of the translucent member facing the light emitting element side is a scattering surface .

  By exposing the side surface of the light emitting element from the wavelength conversion member, the absorption loss due to the wavelength conversion member can be reduced and the light extraction efficiency can be improved. Moreover, since the light emitted from the side surface of the light emitting element is scattered by the wavelength conversion member and returned to the light emitting element, the light extraction efficiency is also improved. On the other hand, the light extracted directly from the exposed side surface of the light emitting element to the outside of the wavelength conversion member is scattered on the scattering surface formed in the concave portion together with the light passing through the wavelength conversion member, and then mixed light from the opening on the upper surface of the concave portion. Therefore, the occurrence of uneven color is also suppressed. In the present invention, since both the light emitting layer and the wavelength conversion member of the light emitting element are separated from the side surface of the recess, the ratio of the light scattered by the scattering surface formed in the recess to return to the light emitting element and the wavelength conversion member There are few. In addition, since both the light emitting layer and the wavelength conversion member of the light emitting element are separated from the side surface of the recess, the light of the light emitting element and the wavelength conversion member is uniformly irradiated over a wider range of the scattering surface formed in the recess. Since it becomes easy, color unevenness can also be suppressed favorably.

  According to the present invention, the light emitting element and the wavelength conversion member are separated from the side surface of the recess, the side surface of the light emitting element is exposed from the wavelength conversion member, and light is directly taken out from the side surface of the light emitting element. Since the scattering surface that can scatter both the light and the wavelength-converted light by the wavelength conversion member is formed, the light extraction efficiency can be increased while suppressing color unevenness.

FIG. 1 is a schematic cross-sectional view showing a light emitting device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an example of a light-emitting element used in the light-emitting device of FIG. FIG. 3 is a schematic diagram showing the relationship between the recesses and the light emitting layer. FIG. 4 is a schematic diagram showing the relationship between the recess and the wavelength conversion member. 5A and 5B are schematic cross-sectional views showing a conventional light emitting device.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Each drawing is a schematic diagram, and the arrangement, dimensions, ratio, shape, and the like shown therein may be different from actual ones. Moreover, in each embodiment, the member using the same code | symbol as other embodiment represents the same or corresponding member, and may abbreviate | omit description.

In this specification, the terms “upper” and “lower” are also used as terms indicating the side from which light emission of the light-emitting device is extracted and the opposite side. For example, “upward” refers to the direction in which the light emission of the light emitting device is extracted, and “downward” refers to the opposite direction. Further, the “upper surface” refers to the surface on the side from which light emission of the light emitting device is extracted, and the “lower surface” refers to the surface on the opposite side. The term “inside” with respect to the light emitting device refers to a side close to the light emitting layer of the light emitting element, and the term “outside” refers to the opposite side. In this specification, “translucency” means that the transmittance of the light emitting element at the emission wavelength is 10% or more. “Mixed” light means that two types of light having different chromaticities are spatially mixed so as to be recognized by human eyes as light having new chromaticity. The “refractive index” in the present invention refers to the refractive index at the emission wavelength of the light emitting element.

  FIG. 1 is a schematic cross-sectional view showing a light emitting device 10 according to an embodiment of the present invention. A light emitting element 20 and a wavelength conversion member 30 that absorbs part of the light emitted from the light emitting element 20 and converts it to a different wavelength are accommodated in a package 16 (accommodator). The package 16 in the present embodiment includes a mounting substrate 12 in which wiring is formed on a flat insulating member, and an annular side wall 14 formed on the mounting substrate 12. When viewed from above, the outer shape of the package 16 is rectangular and is cut into a circular shape to form an annular side wall 14. The light emitting element 20 has a structure as shown in FIG. 2, for example, and includes a light emitting layer 38 made of a semiconductor. Further, the two electrodes 42 and 46 of the light emitting element 20 are connected to the wirings 12a and 12b of the mounting substrate 12 through electrodes and wires formed on the support substrate 32, and can be energized from the outside.

  A recess 16a is formed in the package 16 so that the light emitting element 20 and the wavelength conversion member 30 can be accommodated. Moreover, in this Embodiment, the recessed part 16a is mortar shape so that light emission of the light emitting element 20 and the wavelength conversion member 30 can be taken out efficiently. That is, the recess 16a is formed by the inner surface of the side wall 14 of the package 16 and the upper surface of the mounting substrate 12, but the side wall 14 of the package 16 has an annular shape, and its inner diameter increases as it goes upward. As a result, the concave portion 16a has a mortar shape, and light incident on the surface of the concave portion 16a can be efficiently extracted from above. The concave portion 16a is filled with a translucent sealing member 28. The recess 16a of the package 16 in FIG. 1 is circular in plan view, and has a structure in which a rectangular light emitting element 20 and a rectangular wavelength conversion member 30 are arranged near the center thereof. The light emitting element 20 and the wavelength conversion member 30 are both installed substantially parallel to the bottom surface of the recess 16a. Further, in the present embodiment, the phosphor layer 56 in which the phosphor particles 54 are dispersed is formed on the side surface of the recess 16a, and the phosphor particles 54 scatter the light of the light emitting element 20 and simultaneously convert the wavelength. Also do. More specifically, a phosphor layer 56 in which phosphor particles 54 are dispersed in a phosphor holding member 55 is formed on the inner surface of the side wall 14 of the package. The side wall 14 of the package is made of a material that exhibits a high reflectance at the interface with the phosphor layer 56 at the emission wavelength of the light emitting element 20.

  In the light emitting device 10, the upper surface of the recess 16 a is covered with a light transmissive member 57, and a part of the light emitted from the light emitting element 20 is absorbed to emit light of different wavelengths on the light emitting element side of the light transmissive member 57. The wavelength conversion member 30 is fixed. The wavelength conversion member 30 is plate-shaped, and the side surface of the semiconductor light emitting element 20 is exposed without being covered by the wavelength conversion member 30, and light can be directly extracted. A part of the light emitted from the upper surface of the light emitting element 20 is mainly wavelength-converted by the wavelength conversion member 30, and a part of the light emitted from the side and lower surfaces of the light emitting element 20 is mainly converted by the phosphor layer 56. . Light of a desired color can be obtained by mixing the light thus converted in wavelength and the light of the original light emitting element 20. For example, if the light emitting element 20 emits blue light and the wavelength conversion member 30 emits yellow light, white light emission can be obtained by mixing them.

  The light emitting device according to the present embodiment has a first feature in that the side surface of the light emitting element 20 is exposed without being covered by the wavelength conversion member 30. In a conventional light emitting device, when the side surface of the light emitting element 20 is simply exposed without being covered with the wavelength conversion member 30, light emitted from the side surface of the light emitting element 20 is directly extracted outside without passing through the wavelength conversion member 30. Strong color unevenness occurs. If a scattering agent such as a filler that scatters light is dispersed in the sealing member 28, the light from the light emitting element 20 and the light from the wavelength conversion member 30 can be mixed to suppress uneven color. However, if a sufficient amount of the scattering agent for suppressing the color unevenness is dispersed in the sealing member 28, the ratio of light returning to the inside of the light emitting element 20 increases, and the ratio of light absorbed by the light emitting element 20 increases. As a result, the light emission output decreases.

  Therefore, in the present embodiment, the phosphor layer 56 in which the phosphor particles 54 are dispersed is formed on the side surface of the recess 16a, and the side surface of the recess 16a is used as the scattering surface 18. That is, the phosphor particles 54 are dispersed on the side surface of the recess 16a of the package, and when light is incident thereon, a part of the wavelength is converted and scattered by the phosphor particles 54. As a result, of the light emitted from the light emitting element 20 and the wavelength conversion member 30, the light impinging on the side surface of the recess 16 a of the package is scattered and then extracted to the outside. In the scattering process, the light and wavelength of the light emitting element 20 are extracted. The light of the conversion member 30 is mixed and uneven color is suppressed. Further, since the side surface of the recess 16a of the package is an inclined surface inclined from the upper end toward the center, if a scattering surface is provided on the inclined surface, the scattered light is likely to face the upper surface of the recess 16a.

  That is, in the light emitting device in the present embodiment, the side surface of the light emitting element 20 is exposed without being covered by the wavelength conversion member 30, and the wavelength of the light of the light emitting element 20 and the wavelength conversion member 30 is exposed on the side surface of the recess 16 a. It is characterized in that a scattering surface 18 capable of scattering both of the converted lights is formed, whereby light extraction efficiency can be increased while suppressing color unevenness. By exposing the side surface of the light emitting element 20 from the wavelength conversion member 30, the light from the light emitting element 20 can be extracted without passing through the wavelength conversion member 30, so that the absorption loss due to the wavelength conversion member 30 can be reduced and the light extraction efficiency can be improved. . Moreover, since the probability that light emitted from the side surface of the light emitting element 20 is scattered by the wavelength conversion member 30 and returns to the light emitting element 20 is lowered, the light extraction efficiency is also improved. On the other hand, the light directly extracted from the exposed side surface of the light emitting element 20 is scattered on the scattering surface 18 formed on the side surface of the recess 16a and is wavelength-converted with the light passing through the wavelength conversion member 30, that is, the light of the light emitting element. Together with the light including both of the light, the light is extracted as mixed light from the upper surface of the recess 16a. Furthermore, the light that has passed through the wavelength conversion member 30 and is scattered on the scattering surface 18 is also extracted as mixed light from the upper surface of the recess 16a. Therefore, the occurrence of uneven color can also be suppressed.

  The light emitting device 10 of the present embodiment will be described in further detail with respect to the effect of suppressing color unevenness and improving the light extraction efficiency. First, in terms of light extraction, in addition to the effect that the absorption loss due to the wavelength conversion member 30 is reduced by exposing the side surface of the light emitting element 20, the return light from the wavelength conversion member 30 to the light emitting element 20 is suppressed. There is also an effect of doing. That is, when the wavelength conversion member 30 includes phosphor particles having the same size as the emission wavelength of the light-emitting element 20, the light from the light-emitting element 20 is scattered by the phosphor particles, and the light-emitting element 20 is scattered. Return light is generated. If the side surface of the light emitting element 20 is exposed from the wavelength conversion member 30, there is no return light from the side surface due to scattering of the phosphor particles, and self-absorption by the return light is reduced. Furthermore, in the present embodiment, the side surface of the recess 16a is a scattering surface, and the light emitting layer 38 and the wavelength conversion member 30 of the light emitting element 20 are separated from the side surface of the recess 16a of the package. The ratio of the light from which the scattered light returns to the light emitting element 20 and the wavelength conversion member 30 is small. In particular, if the inner diameter of the concave portion 16a is gradually increased toward the upper side, the light scattered on the side surface of the concave portion 16a becomes easier to move upward on average, and therefore the ratio of returning to the light emitting element 20 and the wavelength conversion member 30 Are even less. Therefore, by using the side wall 14 of the package 16 as a scattering surface, light can be scattered from the side wall 14 and extracted from the upper surface of the recess, and the light emission output hardly decreases. On the other hand, conventionally, since the light emission is scattered by covering the light emitting element 20 and the wavelength conversion member 30 with a member in which a light scattering agent is dispersed, the scattered light is emitted from the light emitting element 20 and the wavelength conversion member. It was easy to return to 30 and light self-absorption occurred.

  Furthermore, normally, the amount of heat generated by the light emitting element 20 when the light emitting device is driven is larger than the amount of heat generated by the wavelength conversion member 30, and thus when the side surface of the light emitting element 20 is exposed from the wavelength conversion member 30 as in the present embodiment. Further, deterioration of the wavelength conversion member 30 due to heat generation of the light emitting element 20 can also be suppressed. That is, if the side surface of the light-emitting element 20 is exposed without being covered with the wavelength conversion member 30 as in the present embodiment, the contact area between the wavelength conversion member 30 and the light-emitting element 20 is also reduced. The deterioration of the wavelength conversion member 30 due to can also be suppressed.

  In the present embodiment, the wavelength conversion member 30 is arranged in the middle of the path from the light emitting element 20 to the upper surface of the recess 16a, and is separated from the light emitting element 20, and the side surface or the bottom surface of the light emitting element 20 and the recess 16a The wavelength conversion member 30 does not exist between the two. In this manner, by providing the wavelength conversion member 30 apart from the light emitting element, it is possible to obtain a light emitting device with improved reliability without being affected by the operating temperature of each other, suppressing deterioration due to heat. In addition, by making the translucent member 57 a member having a higher thermal conductivity than the sealing member 28 such as glass, the heat of the wavelength conversion member 30 can be drawn to the translucent member 57. It is also possible to provide a metal frame that supports the translucent member 57 in the package and to conduct heat through the metal frame. In the present embodiment, since the wavelength conversion member 30 does not exist between the light emitting element 20 and the side surface or the bottom surface of the recess 16a, the light extraction efficiency from the light emitting element 20 is improved. Since the light emitted from the light emitting element 20 to the side and below is subjected to wavelength conversion and scattering by the phosphor layer 56 constituting the scattering surface 18, the occurrence of color unevenness is also suppressed.

In the present embodiment, since the wavelength conversion member 30 and the light emitting element 20 are separated from each other, a part of the light emitted from the light emitting element 20 passes between the wavelength conversion member 30 and the scattering surface 18 and is recessed. There is a case where it directly reaches the opening on the upper surface of 16a. In such a case, as will be described later with reference to FIG. 3, the light from the light emitting element 20 that passes between the wavelength conversion member 30 and the scattering surface 18 and directly reaches the upper surface of the concave portion 16 a is reflected on the upper surface of the concave portion 16 a. It is preferable that the light emitting device is configured to be incident at an angle larger than the critical angle θ _c of total reflection on the surface of the sealing member 28 or the translucent member 57 disposed on the surface. The light returned into the recess 16 a by total reflection can be scattered by the scattering surface 18. Therefore, after the light emitted from the light emitting element 20 passes through either the wavelength conversion member 30 or the scattering surface 18, it is extracted from the upper surface of the recess 16a, and the color unevenness can be improved.

  Further, by adjusting the width or position of the wavelength conversion member 30 such as increasing the width of the wavelength conversion member 30 or bringing it closer to the light emitting element 20, or by adjusting the inclination or depth of the recess 16a, the light emitting element A structure in which light emitted from the exposed side surface 20 is always taken out of the recess 16 a through the wavelength conversion member 30 or scattering on the scattering surface 18 may be adopted. That is, as shown in FIG. 4 to be described later, the upper end of the region where the direct light from the light emitting element 20 reaches may be positioned on the side surface of the recess 16a. When the separation distance between the wavelength conversion member 30 and the light emitting element 20 is large as in the present embodiment, the width of the wavelength conversion member 30 is increased so that the light emitted from the light emitting element 20 does not directly exit from the upper surface of the recess 16a. Then, on the other hand, the distance between the wavelength conversion member 30 and the side surface of the recess 16a is reduced, and the region where the light emitted from the wavelength conversion member 30 to the side and the light emitted from the light emitting element 20 directly reaches is reduced. . Therefore, in order to suppress direct emission of the light emitted from the light emitting element 20 to the outside of the concave portion 16a, a translucent member 57 having a substantially flat surface is provided on the upper surface of the concave portion 16a as in the present embodiment. It is desirable. Thereby, the light emitted from the light emitting element 20 and not passing through the wavelength conversion member 30 can be returned into the recess by total reflection at the interface of the translucent member 57. The translucent member 57 may not be provided, and only the sealing member 28 may be filled in the recess to make the surface substantially flat. Note that the surface of the translucent member 57 or the sealing member 28 is preferably substantially parallel to the upper surface of the light emitting element 20.

  Further, in the present embodiment, the utilization rate of light emitted from the lower surface of the light emitting element 20 is increased by separating a distance d from a light emitting layer 38 to be described later to the bottom surface of the recess 16a by a certain distance or more. For this reason, in particular, it is necessary to convert the wavelength of light emitted from the lower surface of the light emitting element and to extract the light to the outside so as not to cause color unevenness. Further, since the path from the light emitting element 20 to the bottom surface of the recess 16a (that is, the mounting substrate 12) is a heat dissipation path, it is preferable from the viewpoint of durability that this path is made of a member having high heat dissipation. Therefore, in the present embodiment, the phosphor layer 56 having the phosphor particles 54 is provided on the side surface of the recess 16a, whereby wavelength conversion and scattering of light emitted from the lower surface and the side surface of the light emitting element 20 are simultaneously performed. In order to improve heat dissipation, as shown in FIG. 1, the phosphor layer 56 is provided on the side surface of the recess 16a, the mounting substrate 12 is exposed on the bottom surface of the recess 16a, and the mounting substrate 12 and the light emitting element 20 or the support substrate are exposed. It is desirable to connect 32. Members connected to the light emitting element 20 or the support substrate 32 may be wirings 12a and 12b. When the mounting substrate 12 is an insulating member, heat dissipation can be enhanced by connecting to the wirings 12a and 12b made of metal. A heat radiator such as a metal member insulated from the wirings 12a and 12b may be provided, and a support member may be provided on the heat radiator. In particular, as in the present embodiment, when the light-emitting element 20 has no wavelength conversion member on the lower surface, the light-emitting element 20 emits light directly to the outside by forming the scattering surface with a phosphor layer. It can suppress taking out.

  In the present embodiment, the scattering surface 18 formed on the side surface of the recess 16a is preferably formed in as wide a range as possible. However, it is desirable to form at least a part of the side surface of the recess 16a, more preferably the entire side surface. Thereby, uneven color can be effectively suppressed. That is, the color unevenness is caused by the difference in the optical path length when the light emitted from the light emitting element 20 passes through the wavelength conversion member 30, but is irradiated from the light emitting element 20 to the front surface of the plate-shaped wavelength conversion member 30 to convert the wavelength. The light extracted from the main surface of the member 30 has a relatively uniform optical path length in the wavelength conversion member 30 and hardly causes color unevenness, whereas the light extracted from the side surface of the wavelength conversion member 30 is wavelength converted. This is because the light travels diagonally through the member 30 and is emitted, so that uneven color due to the difference in the optical path length of the wavelength conversion member 30 is likely to occur. In addition, the light extracted from the side surface of the plate-shaped wavelength conversion member 30 has an optical path length larger than that of the light extracted from the main surface, so that the intensity of the wavelength-converted light tends to increase. Therefore, as in the present embodiment, each of the light extracted from the side surface of the wavelength conversion member 30 is scattered on the scattering surface 18, mixed with the light directly extracted from the light emitting element 20, and extracted from the upper surface of the recess 16a. Color unevenness can be reduced by arranging the members.

  In particular, when the side surface of the light emitting element 20 is exposed from the wavelength conversion member 30 as in the present embodiment, color unevenness due to light emitted from the side surface of the light emitting element 20 is likely to occur. However, the light emitted from the side surface of the light emitting element 20 is most likely to enter the region facing the side surface of the light emitting layer 38 among the side surfaces of the recess 16a. Therefore, it is preferable to form the scattering surface so as to include a region facing the side surface of the light emitting layer 38 among the side surfaces of the recess 16a. Thereby, the color nonuniformity which generate | occur | produces when the side surface of the light emitting element 20 is exposed without being covered with the wavelength conversion member can also be suppressed effectively. More preferably, light emitted from the wavelength conversion member 30 and the light emitting element 20 in a direction substantially perpendicular to the optical axis direction of the concave portion 16a (that is, a direction substantially parallel to the upper surface of the concave portion 16a) among at least the side surfaces of the concave portion 16a. It forms in the area where That is, in the present embodiment, at least the side surface of the recess 16a, the region where the light emitted from the side surface of the plate-like wavelength conversion member 30 in the direction substantially perpendicular to the side surface reaches the light emitting element 20 It is preferably formed in a region where light emitted from the side surface in a direction substantially parallel to the light emitting layer 38 reaches. Since the wavelength conversion member 30 is likely to have a shape that spreads in a direction parallel to the main surface of the light emitting element 20 such as a plate shape, the wavelength-converted light emitted from the wavelength conversion member 30 to the side is relatively strong. Tends to be strong. Therefore, by forming the scattering surface 18 in a region where the light emitted from the wavelength conversion member 30 is substantially parallel to the upper surface of the concave portion 16a, the color mixture with the light emitted from the side surface of the light emitting element 20 is promoted, and the color unevenness. Can be more effectively suppressed.

  Further, the overlapping region where both the light emitted from the side surface of the light emitting element 20 and the light emitted from the side surface of the wavelength conversion member 30 directly reach the facing region facing the light emitting element 20 and the wavelength conversion member 30 on the side surface of the recess 16a. The light-emitting element 20 and the wavelength conversion member 30 may be arranged so that At this time, it is desirable to provide the scattering surface 18 in the overlapping region. There may be a first region where only light emitted from the side surface of the light emitting element 20 reaches directly above and below the overlapping region, and a second region where only light emitted from the side surface of the wavelength conversion member 30 reaches directly. . By providing the scattering surface 18 in the first region where the direct light from the light emitting element 20 is strong, the light can be scattered, mixed with the light in the overlapping region and the second region, and taken out from the upper surface of the recess 16a. Can be suppressed. Similarly, in the second region where the wavelength-converted light is strong, the uneven color can be suppressed by providing the scattering surface 18. Further, since the light emitted from the upper surface of the light emitting element 20 passes through the wavelength conversion member 30 and is extracted from the upper surface of the recess 16a, both the light emission of the light emitting element 20 and the wavelength-converted light are mixed and the upper surface of the recess 16a. Taken from. In the present embodiment, since the wavelength conversion member 30 does not exist on the lower surface of the light emitting element 20, the light emitted from the lower surface of the light emitting element 20 is directly emitted from the lower surface of the light emitting element 20 to the bottom surface or side surface of the recess 16a. To reach.

  Further, in the present embodiment, in order to satisfactorily mix the light emission of the light emitting element 20 and the light emission of the wavelength conversion member 30 by the scattering surface 18, the light emission of the light emitting element 20 and the wavelength conversion member 30 may It is advantageous to irradiate a wide surface. Therefore, it is desirable to form both the light emitting layer 38 and the wavelength conversion member 30 of the light emitting element 20 apart from the side surface of the recess 16a. More preferably, the light emitting layer 38 and the wavelength conversion member 30 of the light emitting element 20 are formed apart from both the side surface and the bottom surface of the recess 16a. By separating both the light emitting layer 38 and the wavelength conversion member 30 from the side surface and the bottom surface of the recess 16a, a region where both the light emitted from the light emitting element 20 and the light from the wavelength conversion member 30 overlap on the scattering surface 18 can be widened. Can be mixed well. Further, if both the light emitting layer 38 and the wavelength conversion member 30 are separated from the side surface and the bottom surface of the recess 16a, the ratio of the scattered light returning to the light emitting element 20 and the wavelength conversion member 30 is reduced, and the light extraction efficiency is improved. .

  In particular, in the light emitting device 10 according to the present embodiment, the light emitting element 20 is disposed in the recess 16a so that light emitted from the lower surface of the light emitting element 20 can be used efficiently. That is, as shown in FIG. 3, the maximum width in the planar direction of the light emitting layer 38 is w [μm], and the distance d from the light emitting layer 38 of the light emitting element 20 to the bottom surface of the recess 16a is at least 0.5 w [μm] or more. It is preferable to arrange the light emitting layer 38 so that Depending on the structure of the package 16, the bottom surface of the recess 16 a may have some laminated structure. In this case, the surface from which the light emission layer 38 reflects the light most strongly is used as a reference, and from there to the light emission layer 38. Let the distance be d. When the distance from the light emitting layer 38 to the surface of the recess 16a that reflects light is too close, such as when the light emitting element 20 is directly fixed to the bottom surface of the recess 16a, most of the light emitted from the light emitting layer 38 is directed to the light emitting element 20. Returning, the light is absorbed again by the semiconductor layer and the electrode in the light emitting element 20. Assuming light that emerges from the end of the light emitting layer 38 and is reflected by the bottom surface of the recess 16a, if the distance d from the light emitting layer 38 to the bottom surface of the recess 16a is 0.5 w, the light is emitted downward from the end of the light emitting layer 38. Of the light, the incident angle α with respect to the bottom surface of the concave portion 16a (the angle formed by the normal to the bottom surface of the concave portion 16a and the light beam incident on the bottom surface) is 45 ° or more and can be extracted outside. That is, more than half of the light emitted below the light emitting element 20 can be extracted to the outside. Therefore, by setting the distance d from the light emitting layer 38 to the bottom surface of the recess 16 a to be 0.5 w or more, the light emitted downward from the light emitting layer 38 is easily emitted outside without returning to the light emitting element 20. The critical value of the incident angle α becomes smaller as the distance d from the light emitting layer to the bottom surface of the recess 16a becomes longer, and it becomes easier to extract the emitted light to the outside. The distance d from the light emitting layer 38 to the bottom surface of the recess 16a is preferably 1 w [μm] or more, more preferably 2 w [μm] or more. In addition, the light emitting layer 38 is desirably disposed above one third of the depth of the concave portion 16a forming the scattering surface (= distance from the bottom surface to the upper surface of the concave portion 16a). As described above, the light emitting layer 8 in the light emitting element 20 is disposed sufficiently apart from the bottom surface of the recess 16a, so that light emitted downward from the light emitting layer 38 is reflected by the bottom surface of the recess 16a and then again emitted from the light emitting element 20. The probability of returning to itself decreases, and the light can be scattered on the scattering surface, and the light emission of the light emitting element 20 can be used efficiently.

The position of the light emitting layer 38 in the recess 16a also affects the proportion of the light emitted from the light emitting element 20 and the wavelength conversion member 30 that is directly extracted from the upper surface of the recess 16a of the package. If the light emitting layer 38 is arranged away from the upper surface of the recess 16a, the proportion of light directly extracted to the outside of the recess 16a is reduced, so that the effect of color mixing by the scattering surface 18 is enhanced. The maximum width in the planar direction of the light emitting layer 38 is w [μm], and the distance d ₂ from the light emitting layer 38 of the light emitting element 20 to the upper surface of the recess 16a is at least 0.5 w [μm], more preferably 1 w [μm]. It is desirable to arrange the light emitting layer 38 so as to achieve the above. The distance d ₂ is greater than the distance d from the light emitting layer 38 to the bottom surface of the recess portion 16a is desirable. Here, the “upper surface” of the recess 16a refers to a plane including the upper end of the recess 16a. The interpretation of this “upper surface” is the same in other embodiments.

Further, as shown in FIG. 3, an angle formed by a line connecting the center of the light emitting layer 38 and the upper end of the recess 16a and the optical axis of the recess 16a (= the optical axis direction when the recess is a reflecting mirror having no scattering function). Is β, and all the light emitted from the center of the light emitting layer 38 to the upper surface and having an angle of β or less formed by the optical axis of the concave portion 16a directly reaches the upper surface of the concave portion 16a. Therefore, it is preferable to determine the relationship between the concave portion 16a and the light emitting layer 38 so that the angle β is small because the scattering effect on the side surface of the concave portion 16a is increased. It is desirable that the angle β is smaller than 90 °, more preferably 70 ° or less. On the other hand, if the angle β is too small, the light emitting device has a strong directivity of light emission. On the other hand, if the angle β is too small, the light emission of the light emitting element 20 is likely to return to the light emitting element 20 due to repeated scattering on the side surface of the recess 16a, and the output of the light emitting device 10 decreases. Therefore, the angle β is desirably 30 ° or more, more preferably 50 ° or more. Angle β can be adjusted by the distance _{d 2.} about d ₂ is longer, β decreases. Further, the angle β can also be adjusted by increasing or decreasing the width of the opening on the upper surface of the recess 16a that is the emission portion. If the width of the opening is narrowed, β becomes smaller. Note that light emitted from the upper surface of the light emitting element 20 tends to be emitted strongly in a direction substantially perpendicular to the surface of the light emitting element 20.

In the case where the sealing member is filled in the recess 16a, the light that has reached the upper surface of the concave portion 16a, if incident on the upper surface of the concave portion 16a at an angle smaller than the critical angle theta _c for total reflection, as it is to the outside retrieved, if incident at an angle greater than the critical angle theta _c is returned to the recess 16a by total internal reflection. When the critical angle θ _c is smaller than the angle β, the light extracted directly can be reduced, and the light returned into the recess 16a by total reflection can be scattered by the scattering surface, so that the color unevenness can be further improved. . The sealing member can promote total reflection on the surface of the sealing member by setting the surface thereof to a substantially flat surface. On the other hand, when the critical angle θ _c is larger than the angle β, the ratio of light directly extracted increases by setting the critical angle θ _c ≧ angle β, which is preferable from the viewpoint of light extraction efficiency. Further, by increasing the distance d _2, since the ratio of the light output angle greater than the critical angle theta _c can be made small, preferred in terms of light extraction efficiency. The angle β can also be adjusted by increasing or decreasing the width of the opening on the upper surface of the concave portion 16a that is the emission portion. For example, if narrowing the width of the opening, even if long distance d ₂ the ratio of light reaching the scattering surface can be increased. On the other hand, light that is directly extracted by increasing the ratio of light rays having an emission angle that is equal to or greater than the critical angle θ _c , that is, by making the emission part wider, or by reducing the distance d ₂ , for example, d ₂ <d. Since the light returned into the recess 16a by total reflection can be scattered by the scattering surface, the color unevenness can be further improved.

  Further, in order to suppress the return light to the light emitting element 20, it is preferable that the light emitting layer 38 of the light emitting element 20 is sufficiently separated from the side surface of the recess 16a, that is, the scattering surface. The shortest distance from the end of the light emitting layer 38 to the side surface of the concave portion 16a is the maximum width in the planar direction of the light emitting layer 38 w [ It is desirable to arrange the light emitting layer 38 so that it is 0.5 w [μm] or more, 1 w [μm] or more, more preferably 3 w [μm] or more as μm].

    As shown in FIG. 4, from the viewpoint of suppressing color unevenness, the light emitted from the light emitting element 20 passes through the wavelength conversion member 30 or scatters on the scattering surface 18, and then the upper surface of the recess 16 a. Is preferably taken out of. This can be considered separately for light traveling upward, laterally, and downward from the light emitting element 20. In the present embodiment, the light that travels upward from the light emitting element 20 and goes directly to the upper surface of the concave portion 16a reaches the upper surface after passing through the wavelength conversion member 30, and thus the light converted in wavelength by the wavelength conversion member 30 Mixed colors. The light emitted laterally from the light emitting element 20 is scattered by the scattering surface 18 formed on the side surface of the recess 16a together with the light emitted laterally from the wavelength conversion member 30, and mixed with each other. The light emitted downward from the light emitting element 20 is scattered by the scattering surface 18 or reflected by the mounting substrate 12 and mixed with the wavelength-converted light. Therefore, the light emitted from the light emitting element 20 in any direction is mixed with the light whose wavelength is converted by the wavelength conversion member 30, and the occurrence of color unevenness is suppressed. Further, in this embodiment, since the scattering surface 18 is formed by the phosphor layer 56, the light emitted from the light emitting element 20 passes through at least one of the wavelength conversion member 30 and the phosphor layer 56, and one of them. The part is wavelength-converted and taken out from the upper surface of the recess 16a.

  Furthermore, as shown in FIG. 4, when an angle formed by a line connecting the upper end of the side surface of the wavelength conversion member 30 and the upper end of the recess 16a and a line perpendicular to the upper surface of the recess 16a is γ, the angle γ is reduced. The scattering surface facing the side surface of the wavelength conversion member 30 can be increased, and the light extracted directly from the side surface of the wavelength conversion member 30 to the outside can be reduced. It is desirable that the angle γ is less than 90 °, more preferably 70 ° or less. In addition, if the angle γ is too small, the scattered light easily returns to the wavelength conversion member 30 and the light emitting element 20, and the output of the light emitting device 10 decreases, so the angle γ is 30 ° or more, more preferably 50 °. It is desirable to set it above. Moreover, the area | region which faces the side surface of the wavelength conversion member 30 can be enlarged by enlarging the inclination of a scattering surface. Thereby, the area which scatters the light radiate | emitted from the side surface of the wavelength conversion member 30 can be enlarged, and color unevenness can be suppressed further. Further, as shown in FIG. 4, the wavelength conversion member 30 and the light emitting element 20 are controlled in size and arrangement so that a light beam emitted from the side surface of the light emitting layer 38 and traveling outside the wavelength conversion member 30 always hits the recess 16a. Is preferred. Thereby, the light emitted from the exposed side surface of the light emitting element 20 can be scattered by the scattering surface formed in the recess 16a.

  Further, the color unevenness is further suppressed by separating the light emitting element 20 and the wavelength conversion member 30 from the side surface of the recess 16a and adjusting the distance. For example, as shown in FIG. 4, when considering a region where light emitted from the side surface of the light emitting layer 38 of the light emitting element 20 reaches directly on the side surface of the recess 16 a, the side surface of the plate-like wavelength conversion member 30 It is preferable that a region where light emitted in a direction substantially perpendicular to the side surface reaches is included in the region. This relationship can be satisfied by sufficiently separating the light emitting element 20 and the wavelength conversion member 30 from the side surface of the recess 16a. If such a relationship is satisfied, by forming the scattering surface 18 in the above region, the light emitted from the side surface of the light emitting element 20 is efficiently mixed with the light that has passed through the wavelength conversion member 30, and the color Unevenness can be effectively suppressed. Further, by reducing the protruding portion of the wavelength conversion member 30 and increasing the distance between the wavelength conversion member 30 and the light emitting layer 38, the wavelength conversion member 30 emits light from the side surface of the light emitting layer 38 to the side surface of the recess 16a. The emission angle of light that reaches directly can be increased, and the above-described region can be increased. Since the upper end of the region is located on the side surface of the recess 16a, the light emitted from the light emitting element 20 cannot be emitted directly from the upper surface of the recess 16a. Therefore, the direct light of the light emitting element 20 is scattered on the side surface of the recess 16a. The light can be scattered by the light 18 and mixed with the light emitted from the wavelength conversion member 30 to be emitted from the concave portion 16a, and color unevenness is further suppressed.

  In the present embodiment, the light emitting element 20 is fixed to the package 16 via a support substrate 32 made of a light transmissive material such as sapphire. That is, the support substrate 32 is directly bonded to the upper surface of the mounting substrate 12 which is the bottom surface of the recess 16a, and the light emitting element 20 is directly fixed thereon. Since the support member interposed between the light emitting element 20 and the mounting substrate 12 serves as a heat dissipation path from the light emitting element 20 toward the mounting substrate 12, it is preferable to use a material having high thermal conductivity. For example, in the present embodiment, it is preferable that the support substrate 32 constituting the support member is made of a material having high thermal conductivity. The main material of the support substrate 32 is such that the thermal conductivity is 0.8 [W / mK] or more, more preferably 1.2 [W / mK] or more, and still more preferably 35 [W / mK] or more. desirable. As a result, the heat dissipation efficiency of the light emitting element 20 is increased, and thus the light emitting device 10 can be obtained in which the light emission output is hardly reduced even when the light emitting element 20 is lit for a long time. Note that as a part of the support member interposed between the light emitting element 20 and the bottom surface of the recess 16a, a member having low thermal conductivity may be present in a thin film that does not significantly hinder the overall thermal conduction. For example, even if the support substrate 32 is bonded with an adhesive layer having a low thermal conductivity, the thermal conductivity of the entire support member may be within the above range. That is, when the support member is made of a composite material, it is sufficient that the thermal conductivity of the entire support member is not less than a predetermined value. In consideration of heat sinking, it is desirable to provide the support member on at least one of the wirings 12a and 12b. Further, a heat radiating body such as a metal member insulated from the wiring may be provided, and a supporting member may be provided on the heat radiating body. The support member and the wirings 12a and 12b are bonded with resin, metal paste, or the like. It is desirable to use a metal paste having a high thermal conductivity. In this case, adhesion can be improved by providing a metal film on the surface of the support member and bonding the metal film side with a metal paste. The metal film can also be used as a reflective layer.

  In addition, the support member that supports the light emitting element 20 interposed between the light emitting element 20 and the recess 16a preferably has a light transmitting property so as not to absorb light emitted from the light emitting element 20. In addition, as long as it has translucency as a whole, as a part of the support member interposed between the light emitting element 20 and the bottom surface of the recess 16a, a thin film in which a low translucency member does not hinder the entire translucency. It does not matter if it exists. For example, even if a layer made of a member having low light transmission is formed on the light transmitting support substrate 32, the light transmission as a whole of the support member may not be hindered. When such a low light-transmissive member is interposed between the light emitting element 20 and the bottom surface of the recess 16a, the support substrate is set so that the ratio of blocking light from the light emitting layer 38 toward the bottom surface of the recess 16a is reduced. It is desirable to provide a width narrower than 32, more preferably a width narrower than the light emitting layer 38. When a light reflecting member having a larger area than the light emitting element 20 exists between the light emitting element 20 and the bottom surface of the recess 16a, the arrangement of the light emitting layer 38 is adjusted with the light reflecting member as a substantial bottom surface of the recess. It is desirable to do.

  In addition, the 1st wavelength conversion member containing fluorescent substance can also be arrange | positioned as a supporting member. At this time, the support member is preferably laminated in the order of the support substrate 32 and the first wavelength conversion member from the bottom surface of the recess 16a, whereby the first wavelength conversion member can be separated from the bottom surface of the recess 16a. When the first wavelength conversion member is separated from the bottom surface of the recess 16a, the light emitted from the first wavelength conversion member is likely to be widely irradiated on the scattering surface. Further, the rate at which the light scattered or reflected by the recess 16a returns to the first wavelength conversion member also decreases. Moreover, it is preferable that the space between the side surface of the support member made of the support substrate 32 and the first wavelength conversion member and the recess 16a is substantially filled with a light-transmitting member. This is because, if there is a member that substantially blocks light, the color mixture by the scattering surface 18 becomes non-uniform, causing color unevenness. In particular, when a light-shielding member that substantially blocks light exists only in a specific direction with respect to the center of the recess 16a, color unevenness appears strongly. A member with a small light-shielding area, such as a current-carrying wire, has no problem because it does not substantially block light.

Hereinafter, each member which comprises the light-emitting device 10 in this Embodiment is demonstrated in detail.
(Light emitting element 20)
The light emitting element 20 only needs to have a light emitting layer made of a semiconductor. In particular, a light emitting device including a light emitting layer made of a nitride semiconductor, particularly a light emitting layer made of a gallium nitride compound semiconductor (particularly InGaN), can emit strong light in the short wavelength region of the visible light region or the near ultraviolet region. Therefore, it can be suitably combined with the wavelength conversion member. The light emitting element 20 emits light whose emission peak wavelength of the emitted light output from the light emitting layer 38 is in the vicinity of 240 nm to 500 nm, preferably 380 nm to 420 nm, more preferably 450 nm to 470 nm, which is a short wavelength region from near ultraviolet to visible light. It is desirable to have a spectrum. If it is a light emitting element which emits light in this wavelength range, it becomes possible to emit a desired color, particularly white light, in combination with various wavelength conversion members. The light emitting element 20 may have a light emitting layer made of a semiconductor such as ZnSe, InGaAs, or AlInGaP.

  FIG. 2 is a schematic cross-sectional view illustrating an example of the light emitting element 20. A light-transmitting insulating substrate 34 such as sapphire is provided on a first conductivity type (for example, n-type) semiconductor layer 36, a light emitting layer 38, and a second conductivity type (for example, a conductivity type different from the first conductivity type). , P-type) semiconductor layers 40 are sequentially stacked. The second conductive type semiconductor layer 40 and the light emitting layer 38 are partially removed to expose the first conductive type semiconductor layer 36, and a first electrode (n-side electrode) 42 is formed on the exposed surface. . The second conductivity type semiconductor layer 40 has a second electrode (p-side ohmic electrode) 44 formed on substantially the entire surface, and a (p-side) pad electrode 46 for connection to the outside. Each electrode can be a translucent or reflective electrode. Usually, a translucent electrode is used when the electrode forming surface is mounted on the upper side, and the electrode forming surface is formed as shown in FIG. In the case of the light emitting element 20 that is flip-chip mounted as the lower side, a reflective electrode is used.

  As shown in FIG. 1, in this embodiment, the substrate 34 of the light emitting element 20 is flip-chip mounted on the support substrate 32 with the substrate 34 facing upward. Mounting electrodes are formed on the upper surface of the support substrate 32 and are connected to the first electrode 42 and the second electrode 46 of the light emitting element 20 via solder bumps or the like. The electrodes formed on the upper surface of the support substrate 32 are further connected to the wirings 12a and 12b of the mounting substrate 12 by wires. As a result, the light emitting element 20 can be electrically driven from the outside. For the electrode formed on the upper surface of the support substrate 32, a member that substantially shields light from the light emitting layer 38 is usually used. For this reason, the electrode on the upper surface of the support substrate 32 is formed only on a part of the upper surface of the support substrate 32 so that light traveling downward from the light emitting element 20 can reach the bottom surface of the recess 16a. Preferably, the electrode portion protruding from the light emitting element 20 in a top view is formed with a width smaller than the width of the light emitting element 20.

  The light emitting element 20 that can be used in the present invention is not limited to the structure shown in FIG. For example, each conductive type layer may be provided with an insulating, semi-insulating, and reverse conductive type structure in part. Further, the substrate 34 may be conductive, and in this case, the first electrode 42 may be formed on the back surface of the substrate 34. The substrate 34 may be a substrate used for growing a semiconductor layer, or may be a substrate bonded after the semiconductor layer is grown. Alternatively, the substrate can be peeled off and only the semiconductor layer can be used as a light-emitting element. The shape of the light emitting element 20 in a top view is typically a rectangle, and preferably a substantially square shape. By making it substantially square, the distance from each side of the light emitting element 20 to the scattering surface can be made substantially equal, and color unevenness can be easily suppressed. The top view shape of the support substrate 32 is preferably substantially the same as that of the light emitting element 20. As the light emitting element 20, one having a side of about several hundred μm to several mm can be used, and specifically, a substantially square element having a side of about 400 μm to 1 mm can be used. At this time, the distance from the side surface of the light emitting element 20 to the scattering surface 18 is, for example, about 0.5 to 2 mm.

(Wavelength conversion member 30)
The wavelength conversion member 30 is not particularly limited as long as it can absorb part of the light emitted from the light emitting element 20 and emit light of different wavelengths. The wavelength conversion member 30 may be a member in which a wavelength conversion substance such as a phosphor is contained in a translucent member such as glass or resin, or may be a member made of a crystal of the wavelength conversion substance or an amorphous body itself.

As the wavelength converting substance, a phosphor excited by near ultraviolet light or visible light is particularly preferable. In particular, when the light-emitting element 20 is a blue light-emitting element and a white light-emitting device is desired, it is preferable to use a phosphor that is excited in blue and exhibits yellow broad light emission as the wavelength conversion material. Examples of such a phosphor include a phosphor having a garnet structure activated by cerium (particularly, a phosphor activated by cerium and containing aluminum and having a garnet structure). Since the phosphor activated with cerium emits light in yellow and broad, white having good color rendering properties can be realized in combination with blue light emission. In addition, a garnet structure, particularly a phosphor having a garnet structure containing aluminum, is resistant to heat, light, and moisture, and can maintain yellow light emission with high luminance for a long time. For example, as the wavelength conversion _{material, (Re 1-x Sm x} ) 3 (Al 1-y Ga y) 5 O 12: Ce (0 ≦ x <1,0 ≦ y ≦ 1, where, Re is, Y, Gd It is preferable to use a YAG-based phosphor (generally abbreviated as YAG) represented by at least one element selected from the group consisting of La, Lu, and Tb. In addition to the yellow phosphor, Lu ₃ Al ₅ O ₁₂ : Ce, BaMgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Mn, (Zn, Cd) Zn: Cu, (Sr, Ca) ₁₀ ( Color rendering properties can also be adjusted using phosphors such as PO ₄ ) ₆ Cl ₂ : Eu, Mn, (Sr, Ca) ₂ Si ₅ N ₈ : Eu, CaAlSiB _x N _{3 + x} : Eu, and CaAlSiN ₃ : Eu. .

  In particular, when the emission wavelength of the light emitting element 20 is a short wavelength, the wavelength conversion member 30 may include two or more types of wavelength conversion substances. It is also possible to excite and emit the first type of wavelength converting substance by the primary light from the light emitting element 20 and to excite and emit another type of wavelength converting substance by the secondary light emitted from the wavelength converting substance. In addition, if two types of phosphors having different chromaticities are used, an area formed by connecting the two types of phosphors and the chromaticity points of the light emitting elements on the chromaticity diagram by adjusting the amount of the two types of phosphors. Light emission corresponding to any of the chromaticity points can be obtained.

  For example, the wavelength conversion member 30 may include a phosphor having yellow to red light emission in addition to the yellow light-emitting phosphor. Thereby, a reddish component can be increased and a light emitting device having a high average color rendering index Ra can be obtained. If the light emitting device has a high average color rendering index Ra, the light emitting device is suitable for lighting applications. Moreover, it can also be set as the light-emitting device which light-emits a light bulb color by increasing a reddish component. Examples of phosphors that convert near-ultraviolet to visible light into a yellow to red region include nitride phosphors, oxynitride phosphors, and silicate phosphors.

Nitride-based phosphors and oxynitride (oxynitride) phosphors include Sr—Ca—Si—N: Eu, Ca—Si—N: Eu, Sr—Si—N: Eu, and Sr—Ca—Si. -O-N: Eu, Ca-Si-O-N: Eu, Sr-Si-O-N: Eu, etc. are mentioned. Among the nitride phosphors and oxynitride phosphors, alkaline earth silicon nitride phosphors are preferable, and can be represented by the following general formula (L is any one of Sr, Ca, Sr and Ca).
_{LSi 2 O 2 N 2: Eu} , L x Si y N (2 / 3x + 4 / 3y): Eu, L x Si y O z N (2 / 3x + 4 / 3y-2 / 3z): Eu

Examples of the silicate phosphor include L ₂ SiO ₄ : Eu (L is an alkaline earth metal), (Sr _x Mae _1-x ) ₂ SiO ₄ : Eu (Mae is an alkaline earth metal such as Ca and Ba), and the like. preferable.

  On the other hand, as the translucent member containing the wavelength converting substance, an organic material or an inorganic material having translucency with respect to the light of the light emitting element 20 can be used. As the organic material, a resin having translucency is preferable. For example, it is preferable to use a silicone resin composition, a modified silicone resin composition, or the like, but an insulating resin composition having translucency such as an epoxy resin composition, a modified epoxy resin composition, or an acrylic resin composition is used. Can do. Also, a resin excellent in weather resistance such as a hybrid resin containing at least one of these resins can be used. Moreover, as an inorganic material, amorphous materials, such as glass, an inorganic crystal, a ceramic, etc. can be used. As described above, in the case where the wavelength conversion member is a phosphor crystal or an amorphous material, which is a wavelength conversion material, a light transmissive member is not necessary.

  It is preferable that the wavelength conversion member is a composite material of an inorganic binder made of an inorganic material and a phosphor because scattering inside the wavelength conversion member is suppressed and durability is improved. As the inorganic binder, inorganic crystals such as sapphire, amorphous materials such as glass, and various inorganic materials such as ceramics can be used. In general, an inorganic material such as glass or sapphire has a small difference in refractive index from a phosphor made of an inorganic material. For example, the refractive index of a phosphor having a garnet structure including aluminum is about 1.7 to 1.8, whereas the refractive index of a general light-transmitting resin is about 1.5, whereas the refractive index of glass. The refractive index is about 1.6, and the refractive index of sapphire is about 1.7. For this reason, there is little scattering of the light by the fluorescent substance in the wavelength conversion member, and light can be efficiently extracted from the wavelength conversion member. The inorganic binder may be any inorganic material as long as it is translucent, but the refractive index difference from the phosphor is smaller than 0.3, more preferably 0.2 or less, and even more preferably 0.1. The following is desirable.

  In this case, the structure of the wavelength conversion member is preferably a structure in which the phosphor and the inorganic binder are mixed almost uniformly. For example, it is preferable that the wavelength conversion member has a sea-island structure in which one of the phosphor and the inorganic binder is dispersed in an island shape in the other because uniform wavelength conversion can be performed in the wavelength conversion member. In this case, a structure in which the island-shaped phosphor is dispersed in the inorganic binder or a structure in which the island-shaped inorganic binder is dispersed in the phosphor may be employed. For uniform wavelength conversion, the diameter of the island in the sea-island structure can be, for example, about 1 μm to 50 μm.

  The wavelength conversion member 30 provided on the upper surface of the light emitting element 20 mainly plays a role of converting the wavelength of the light emitted from the light emitting element 20 that does not hit the recess 16a of the package and is directly extracted outside. Since such light is not mixed by scattering, the wavelength conversion member 30 is preferably formed so that the optical path length through which the light emitted from the light emitting element 20 passes is substantially uniform. Thus, a light emitting device with little color unevenness can be obtained. Specifically, the wavelength conversion member 30 preferably covers the upper surface of the light emitting element 20 with a substantially uniform thickness, and preferably has a plate shape.

  For example, the wavelength conversion member 30 is preferably plate-shaped. When the wavelength conversion member 30 is plate-shaped, a part of the light in the wavelength conversion member 30 is totally reflected by two opposing main surfaces and is emitted from the side surface. For this reason, the light emitted from the side surface has a large optical path length in the wavelength conversion member, and the intensity of the wavelength-converted light tends to increase, and in principle, color unevenness is likely to occur. However, in the present embodiment, since the side surface of the light emitting element 20 is exposed, light emission of the light emitting element 20 that emits in the same direction as the side surface of the wavelength conversion member 30 is also strong. Since the light emitted from the light emitting element 20 and the wavelength conversion member 30 is scattered by the recess 16a, the occurrence of uneven color is suppressed even if the wavelength conversion member 30 is plate-shaped. In this case, the wavelength conversion member 30 is preferably installed in parallel with the light emitting element 20.

The wavelength conversion member 30 is preferably made of an inorganic material. In particular, it is desirable to use an inorganic material having a thermal conductivity of 0.8 [W / mK] or more, more preferably 1.2 [W / mK] or more, and even more preferably 35 [W / mK] or more. Specifically, the wavelength conversion member 30 can be formed by using an inorganic phosphor crystal or an amorphous material itself as the wavelength conversion member 30, or by incorporating inorganic phosphor particles in a transparent member made of an inorganic material. Examples of the case where the wavelength conversion member 30 is made of an inorganic phosphor crystal or amorphous substance itself include YAG, (Sr, Ba) ₂ SiO ₄ : Eu, and the like. When inorganic phosphor particles are contained in a transparent member made of an inorganic material, an amorphous material such as glass, an inorganic crystal, ceramic, or the like can be used as the transparent member of the inorganic material. For example, a sintered body of phosphor particles and transparent member particles, or a sintered body of phosphor particles and glass can be used. A phosphor particle and a polycrystal of another member may be used. By configuring the wavelength conversion member with such a material, the durability of the wavelength conversion member 30 itself is enhanced, and at the same time, heat radiation is improved, and the highly reliable light-emitting device 10 can be realized. Further, the wavelength conversion member 30 made of an inorganic material has a higher hardness than that of an organic material such as a resin, and can be processed at a high temperature.

  The wavelength conversion member 30 preferably has an outer dimension in the planar direction larger than that of the light emitting element 20 and protrudes from the outer periphery of the light emitting element 20 in a hook shape. Thereby, the emitted light from the upper surface of the light emitting element 20 can be extracted outside after passing through the wavelength conversion member 30. For example, when the size of the wavelength conversion member 30 is the same as that of the light emitting element 20, most of the light emitted obliquely upward from the side surface of the light emitting layer 38 passes outside the wavelength conversion member 30 and is recessed 16 a. There may be a case where it is taken out directly to the outside of the recess 16a while avoiding the scattering surface on the side surface. Therefore, as shown in FIG. 1, if the wavelength conversion member 30 is made larger than the light emitting element 20 and protrudes from the outer periphery of the light emitting element 20 in a bowl shape, the light extracted directly to the outside of the recess 16 a can be reduced. it can. In addition, if the wavelength conversion member 30 protrudes from the outer periphery of the light emitting element 20 to such an extent that this can be achieved, the size and planar shape of the wavelength conversion member are not particularly limited. However, if the wavelength conversion member 30 is too large, the light scattered by the concave portion 16a will pass through the wavelength conversion member 30 again, resulting in color unevenness and a decrease in light emission output. The maximum dimension in the planar direction of the wavelength conversion member 30 in the present embodiment is 1.1 times or more, preferably 1.5 or more times, and 3 or less times the maximum dimension in the planar direction of the light emitting layer 38 of the light emitting element 20. Preferably, it is desirable to make it 2 times or less.

(First wavelength conversion member)
In addition, a first wavelength conversion member can be provided between the support substrate 32 and the light emitting element 30. The material and shape of the first wavelength conversion member can be the same as those of the wavelength conversion member 30 described above. The first wavelength conversion member is preferably formed in contact with the lower surface of the light emitting element 20, mainly converts the wavelength of light emitted from the lower surface of the light emitting element 20, and serves as a substrate for fixing the light emitting element 20, It also serves as a heat dissipation path from the light emitting element 20 to the mounting substrate 12. In the present embodiment, the light emitted from the side surface and the lower surface of the light emitting element 20 and the light emitted from the first wavelength conversion member are scattered by the scattering surface 18 formed in the recess 16a and mixed to the outside. Emitted. Therefore, since the first wavelength conversion member does not need to scatter light inside, the first wavelength conversion member is preferably a composite material of an inorganic binder made of an inorganic material and a phosphor. Thereby, the return light from the first wavelength conversion member to the light emitting element 20 can be suppressed. The first wavelength conversion member does not need to be strictly restricted in shape and arrangement in consideration of color unevenness, and can have a relatively free shape and arrangement as long as the light of the light emitting element 20 can be wavelength-converted.

  The first wavelength conversion member is preferably plate-shaped. If the first wavelength conversion member is plate-shaped, the light emitting element 20 can be stably fixed. Further, if the first wavelength conversion member is formed into a plate shape, the first wavelength conversion member is processed as a large plate material when the light emitting device 10 is manufactured, and is cut into a desired size. Since it can adhere | attach on the support member 32, there exists a merit which the assembly of the light-emitting device 10 becomes easy. Further, the first wavelength conversion member in the present embodiment also functions as a mounting surface on which the light emitting element 20 is flip-chip mounted. However, if the first wavelength conversion member is plate-shaped, wiring can be easily formed. . For example, a wiring pattern can be collectively formed on a first wavelength conversion member processed into a large plate shape, and the wiring pattern can be cut out and bonded onto the support member 32. By connecting the wiring pattern on the surface of the first wavelength conversion member and the light emitting element 20 with a conductive member such as metal or resin or an adhesive, heat generated by the light emitting element 20 is transferred to the first wavelength conversion member via the wiring pattern. I can escape. When the light emitting element 20 is flip-chip mounted, the light emitting layer 38 that easily generates heat can be brought close to the first wavelength conversion member, and heat can be efficiently radiated. When the first wavelength conversion member is plate-shaped, the light emission at the end face tends to be strong, so that color unevenness is likely to occur in principle. However, in the present embodiment, since the side surface of the light emitting element 20 is exposed, the light emission of the light emitting element 20 emitted in the same direction as the end face of the first wavelength conversion member is also strong. Since the light emitted from the light emitting element 20 and the first wavelength conversion member is scattered by the concave portion 16a, the occurrence of uneven color is suppressed even if the first wavelength conversion member is plate-shaped.

  In addition, a translucent member can be arrange | positioned on the upper surface of such a plate-shaped 1st wavelength conversion member, and a light emitting element can also be provided on it. Further, in order to be “plate-shaped”, the entire shape may be plate-shaped, and may have a recess or a hole for placing the light-emitting element. Further, a pattern for obtaining some optical effect may be formed on the surface. When the wavelength conversion member 32 or the first wavelength conversion member is “plate-shaped”, the planar shape is not limited to a rectangle, and may be various shapes such as a circle and an ellipse.

  The top view shape of the wavelength conversion member 30 is preferably substantially square, similar to the light emitting element 20. The wavelength conversion member 30 overlaps with the light emitting element 20 in a top view and is preferably larger than the light emitting element 20. Specifically, the length of one side of the wavelength conversion member 30 can be about 1.5 to 3.5 times the length of one side of the light emitting element 20. For example, when the light emitting element 20 has a substantially square shape with a side of about 450 μm, the wavelength conversion member 30 has a substantially square shape with a side of about 1 mm, and when the light emitting element 20 has a substantially square shape with a side of about 1 mm, the wavelength conversion is performed. The member 30 has a substantially square shape with a side of about 1.5 mm. At this time, the distance from the side surface of the wavelength conversion member 30 to the scattering surface can be about 0.5 to 1.5 mm. Moreover, the thickness of the wavelength conversion member 30 can select the thickness from which desired chromaticity is obtained, for example, shall be 100 micrometers-200 micrometers. If the wavelength conversion member 30 and the first wavelength conversion member are made of the same material, the manufacturing cost can be reduced by sharing the members.

  A pattern for obtaining some optical effect such as a lens pattern may be formed on the light receiving surface and the light emitting surface of the wavelength converting member 30 and the first wavelength converting member. As described above, the wavelength conversion member 30 in the present embodiment is “plate-like”, but any pattern may be formed on the surface as long as the overall shape is plate-like. Further, even if a certain pattern is on the fixing surface of the light emitting element, the light emitting element can be stably fixed if the period of the pattern is sufficiently small with respect to the size of the light emitting element.

(Package 16, recess 16a)
If the package 16 has a concave portion 16a with a part of the side surface being a scattering surface and can accommodate the light emitting element 20 and the wavelength conversion member 30 so that electrical connection to the light emitting element 20 is possible, Any structure is acceptable. In the present embodiment, the package 16 includes a mounting substrate 12 in which wirings 12a and 12b are formed on a flat insulating member, and an annular side wall 14 formed on the mounting substrate 12, and the package 16 in a top view. The outer shape of this is a rectangle and is cut into a circle to form an annular side wall 14. A recess 16 a is configured by the upper surface of the mounting substrate 12 and the inner surface of the side wall 14. In the present embodiment, the side surface of the recess 16a is used as the scattering surface 18 by forming the phosphor layer 56 in which the phosphor particles 54 are dispersed on the side surface of the recess 16a. As a result, the light directly extracted from the light emitting element 20 is increased, and the light emitted from the light emitting element 20 with a scattering surface is mixed with the light having passed through the wavelength conversion member 30 and wavelength-converted, so that It can be taken out from the upper surface, and the light emission output can be improved by suppressing color unevenness. In the present embodiment, the side surface of the recess 16a is a scattering surface, but a scattering surface can also be provided on the bottom surface of the recess 16a. For example, an appropriate scattering layer may be formed so as to leave a wire connection region on the surface of the mounting substrate 12. In the present embodiment, the light emitted from the semiconductor element 20 is scattered as it is on the scattering surface 18 so as not to be accompanied by optical effects other than scattering (for example, absorption or wavelength conversion). As a result, the loss of light generated on the scattering surface 18 can be suppressed, and the light extraction efficiency can be increased.

  The concave portion 16a may have any shape as long as the light emitting element 20 and the wavelength conversion member 30 can be accommodated and the upper surface is opened so that light can be extracted. However, the bottom surface of the recess 16a is preferably flat so that the light emitting element 20 and the like can be stably fixed. Moreover, it is preferable that the internal diameter of the recessed part 16a becomes large gradually from the bottom face toward the upper surface. Further, the recess 16a preferably has a circular shape in plan view, thereby improving the uniformity of light emission and suppressing color unevenness. The light emitting element 20 is usually rectangular in plan view, and even if the entire surface of the light emitting element 20 is covered with a wavelength conversion member, color unevenness is likely to occur. By scattering on the scattering surface, the uniformity of light emission can be improved and color unevenness can be suppressed. The plate-like wavelength conversion member 30 is easy to manufacture when the shape in plan view is rectangular, and such a rectangular light source is preferably scattered on the scattering surface of the circular recess 16a. In particular, when the planar view shape of the light source including the light emitting element 20 and the wavelength conversion member 30 is rectangular, there is a difference in intensity between the light emitted from the sides of the rectangle and the light emitted from around the corners. However, the unevenness of color due to the shape of the light source can be suppressed by scattering the light thus extracted in the circular recess 16a. Furthermore, it is preferable that the concave portion 16a has a mortar shape that is circular in plan view when viewed at any height. The light source including the light emitting element 20 and the wavelength conversion member 30 is preferably disposed at the center of the recess 16a in plan view. In order to efficiently extract the light irradiated on the scattering surface, the scattering surface 18 formed on the side surface of the concave portion 16a can be observed outside the light emitting element 20 and the wavelength conversion member 30 when viewed from above. It is desirable to be.

  The scattering surface 18 formed on the side surface of the recess 16 a is a surface capable of scattering the light emission of the light emitting element 20 and the light emission of the wavelength conversion member 30. In order to make the surface capable of scattering, in addition to forming the phosphor layer 56 described above, the size is equal to or smaller than the shorter wavelength of the light emission of the light emitting element 20 and the light emission of the wavelength conversion member 30, And a surface on which fine structures made of materials having different refractive indexes are distributed.

For example, a scattering surface can be obtained by dispersing translucent particles having a refractive index different from that of the base material in the translucent base material. The refractive index difference between the particles and the surrounding material is preferably 0.1 or more, more preferably 1.0 or more. The “refractive index” referred to here refers to the refractive index in air. The particles include glass fibers, glass beads, talc, silica, alumina, magnesia, zinc white, calcium carbonate, barium sulfate, titania, aluminum hydroxide, mica, feldspar powder, quartz powder and other inorganic particles, silicone resin Organic particles such as fluorine resin, epoxy resin, and styrene-based crosslinked resin can be used, and one of these can be used alone or in combination of two or more. As the particles, oxides containing any of Ti, Zr, Nb, Al, and Si, AlN, MgF, and the like are particularly preferable (oxides containing Ti, Zr, Nb, Al, and Si include TiO ₂ , ZrO, and the like). ₂ , Nb ₂ O ₅ and Al ₂ O ₃ are preferred). Among these, an oxide containing any of Ti, Zr, Nb, and Al is preferable. Particles made of these materials are preferable because they have a high refractive index and a high refractive index with the sealing member, so that scattering is increased. In addition, any oxide is preferable because it does not absorb in the visible light region and does not contribute to a reduction in efficiency. The particles are preferably contained to such an extent that they are observed as white. This makes it possible to form a scattering surface 18 with low translucency and high reflectance, and to improve the light extraction efficiency from the upper surface of the recess 16a.

The average particle size R of the particles preferably satisfies 0.4 × λ / π <R <λ, where λ is the emission wavelength of the light emitting element 20 so that scattering occurs efficiently. When the average particle diameter R of the particles becomes 0.4 × λ / π or less, the particle enters the Rayleigh scattering region, and the scattering intensity is proportional to the fourth power of the wavelength. Therefore, the scattering of the light emission of the phosphor having a long wavelength is weakened. The average particle diameter R of the particles is 70 nm or more, preferably 200 nm or more, and is 400 nm or less, preferably 300 nm or less. Moreover, the scattering coefficient of a scattering surface can be adjusted with the quantity which contains particle | grains. For example, the amount of the particles can be 10 to 50% by weight, and particularly when the particles of TiO ₂ are contained, the amount is preferably 20 to 40% by weight. If the content of the particles is 30% by weight or more, it is preferable because the scattering on the scattering surface 18 becomes strong and the reflectance becomes high. On the other hand, as the surrounding base material containing the particles, silicone resin, epoxy resin, glass and the like are preferable. Among them, silicone resins have thermosetting properties, light resistance, and relatively soft properties. Silicone resin has a low refractive index of about 1.4, and therefore, it is easy to make a difference in refractive index between particles such as TiO2 (refractive index of about 2.5), and is preferable for enhancing scattering by the scattering surface.

  In addition, you may form the scattering surface 18 formed in the side surface of the recessed part 16a with another method. For example, if the side wall 14 is formed using a porous body formed by agglomerating and sintering particles, the inner surface thereof can be used as a scattering surface. Moreover, it is good also as the side wall 14 using the porous body shape | molded by the sol gel method. In such a porous body, scattering occurs based on a difference in refractive index between the material of the porous body and air (or a substance having a different refractive index filled therein) existing in the pores of the porous body. In addition, when such a porous body is used for the side wall 14, in order to improve sealing performance and airtightness, it is good also as a composite material of a porous body and resin. Moreover, it can also be set as a scattering surface by giving uneven | corrugated processing or roughening to the surface of a translucent member or a reflective member, or forming a scattering particle layer in the surface.

  Moreover, although it is preferable to form the scattering surface 18 formed in the side surface of the recessed part 16a in the widest possible range, it is preferable to form it in at least a part of the side surface of the recessed part 16a. More preferably, it should be formed on the entire side surface of the recess 16a. Thereby, uneven color can be effectively suppressed. That is, the color unevenness is caused by the difference in the optical path length when the light emitted from the light emitting element 20 passes through the wavelength conversion member 30, but for the light traveling from the light emitting element 20 toward the bottom surface or the upper surface of the recess 16a, the wavelength conversion member. While the light path length of 30 is relatively uniform and color unevenness is unlikely to occur, the color unevenness due to the difference in the light path length of the wavelength conversion member 30 for light traveling obliquely from the light emitting element 20 toward the side surface of the recess 16a. It is because it is easy to generate | occur | produce. In addition, when providing the scattering surface 18 in a part of side surface of the recessed part 16a, it is preferable to form the scattering surface 18 so that the circumference | surroundings of the light emitting element 20 may be enclosed equally. That is, it is preferable that the scattering surface 18 is formed uniformly in all directions with the center of the light emitting element 20 as a reference in plan view. This is because, when the scattering surface 18 is formed widely only in a certain direction with respect to the center of the light emitting element 20, or when the scattering surface 18 is not formed only in a certain direction, color unevenness is caused.

  In particular, when the plate-like wavelength conversion member 30 is provided as in the present embodiment, light emission tends to be strong on the side surface of the plate-like body, and thus uneven color tends to occur. However, if it is a plate-like body installed in parallel to the bottom surface of the recess 16a, the light emitted from the side surface of the plate-like body is the most in the region of the side surface of the recess 16a that faces the side surface of the plate-like body. Easy to enter. Therefore, it is preferable to form a scattering surface in a region facing the side surface of the plate-like wavelength conversion member, among the side surfaces of the recess 16a. Thereby, the color nonuniformity which generate | occur | produces because the wavelength conversion member 30 is plate shape can also be suppressed effectively. Further, in order to suppress the return light to the light emitting element 20, the scattering surface radiates light from the light emitting element 20 in a direction substantially parallel to the main surface of the light emitting element 20 or on the upper surface side of the recess 16a. Is desirable.

The “bottom surface” of the concave portion 16a refers to a region of the concave portion 16a that includes the projection surface of the light emitting element 20 in the optical axis direction of the concave portion 16a and is not more than the same height as the projection surface. "" Refers to the region rising from the "bottom surface". The interpretation of the “bottom surface” and the “side surface” is the same for the recess 16a in the other embodiments.
(Phosphor layer 56)

  In order to sufficiently suppress the color unevenness, it is necessary to disperse the phosphor particles 54 in the phosphor layer 56 so that the light from the light emitting element 20 is scattered by the phosphor particles 54. Therefore, the average particle diameter of the phosphor particles 54 is 3 μm or more, preferably 10 μm or more. Further, it is desirable that the difference in refractive index between the phosphor particles 54 and the surrounding material is greater than 0 and 0.4 or less. Here, “refractive index” refers to the refractive index at the emission wavelength of the light emitting element 20. As the material of the phosphor particles 54, the same phosphor material as that of the wavelength conversion member 30 can be used.

  As a material of the phosphor layer 56 in which the phosphor particles 54 are dispersed, an organic material or an inorganic material having translucency with respect to the light of the light emitting element 20 can be used. As the organic material, a resin having translucency is preferable. For example, it is preferable to use a silicone resin composition, a modified silicone resin composition, or the like, but an insulating resin composition having translucency such as an epoxy resin composition, a modified epoxy resin composition, or an acrylic resin composition is used. Can do. Also, a resin excellent in weather resistance such as a hybrid resin containing at least one of these resins can be used. Moreover, as an inorganic material, amorphous materials, such as glass, an inorganic crystal, a ceramic, etc. can be used.

  The sidewall 14 in the present embodiment is preferably made of a material having a high reflectance with respect to the light emission of the light emitting element 20. For example, if the material of the side wall 14 outside the phosphor layer 56 is made to have a lower refractive index than the material constituting the phosphor layer 56, the reflectivity at the interface between the phosphor layer 56 and the side wall 14 is preferably increased. . The difference in refractive index between the material of the side wall 14 and the material constituting the phosphor layer 56 is 0.05 or more, preferably 0.1 or more. Silicone, epoxy, or the like can be used as the material of the side wall 14.

  In the present embodiment, the phosphor layer 56 including the phosphor particles 54 is preferably formed on at least part of the side surface of the recess 16a, preferably on the entire side surface. Thus, when the side surface of the light emitting element 20 is exposed from the wavelength conversion member, the light emitted from the side surface of the light emitting element 20 can be reliably wavelength-converted and scattered. Further, in order to wavelength-convert and scatter light emitted from the lower surface of the light emitting element 20, it is preferable to cover the side surface of the recess 16a with the phosphor layer 54 up to the boundary with the bottom surface of the recess 16a. If the concave portion 16a has a mortar shape having an inner diameter that increases upward, the side surface of the concave portion 16a is covered with the phosphor layer 54, so that the light emitted from the lower surface of the light emitting element 20 is also wavelength-converted and scattered. It becomes easy to do. If the side surface of the recess 16a is covered with the phosphor layer 16a, it is sufficient to cover the inner surface of the side wall 14 with the phosphor layer 56, so that the assembly of the light emitting device 10 is facilitated.

  In addition, you may provide the fluorescent substance layer 56 not only to the side surface of the recessed part 16a but to the bottom face of the recessed part 16a. However, it is preferable not to provide the phosphor layer 56 in the path from the light emitting element 20 to the bottom surface of the recess 16a in the bottom surface of the recess 16a. Since the portion from the light emitting element 20 to the bottom surface of the recess 16a is a heat dissipation path of the light emitting element 20, if the phosphor layer 56 exists in this path, the heat dissipation efficiency is lowered and the deterioration of the phosphor layer 56 itself is accelerated. .

  In addition, the wavelength conversion member 30 in the present embodiment is preferably formed only on the upper surface of the light emitting element 20, and the side surface and the lower surface of the light emitting element 20 are preferably exposed from the wavelength conversion member 30. The reason why the wavelength conversion member 30 is provided on the upper surface of the light emitting element 20 is to convert the wavelength of the light emitted from the light emitting element 20 that is extracted outside without hitting the recess 16a of the package. The wavelength conversion member 30 in the present embodiment preferably projects from the outer periphery of the light emitting element 20 in a bowl shape. The wavelength conversion member 30 is preferably made of an inorganic material.

  The phosphor layer 56 including the phosphor particles 54 and the wavelength conversion member 30 may include a phosphor having yellow to red emission in addition to the phosphor emitting yellow. In this way, a multilayer structure in which layers containing different phosphors are stacked may be used. In this case, it is preferable that the wavelength conversion member 30 has a phosphor layer that emits light at a short wavelength on the light emitting element 20 side. It is preferable.

(Supporting substrate 32)
In the present embodiment, the light emitting element 20 is fixed to the mounting substrate 12 via the support substrate 32 so that the light emitting layer 38 of the light emitting element 20 is separated from the bottom surface of the recess 16a of the package by a predetermined distance. In the present embodiment, the support substrate 32 is preferably transparent to the light emitted from the light emitting layer 38 so that the light emitted downward from the light emitting layer 38 can be used efficiently. Moreover, since the support substrate 32 forms a heat dissipation path from the light emitting element 20 to the mounting substrate 12, it is preferable that the support substrate 32 be made of a material having high thermal conductivity. It is desirable to use a material having a thermal conductivity of 0.8 [W / mK] or more, more preferably 1.2 [W / mK] or more, and still more preferably 35 [W / mK] or more.

  As the support substrate 32, inorganic materials, such as sapphire and glass, can be used, for example. Among these, sapphire is preferable because it has a relatively high thermal conductivity and exhibits high transmittance with respect to the blue light emitted from the light emitting element 20.

(Mounting board 12)
The mounting substrate 12 only needs to have a wiring on the surface that is electrically connected to the light emitting element 20. In the present embodiment, wiring is formed on a flat insulating member to form the mounting substrate 12. As the insulating member, ceramic such as aluminum nitride or alumina, or glass can be used. Further, an insulating thin film layer such as aluminum nitride may be formed on the surface of a semimetal such as Si or metal. These mounting boards 12 are preferable because of their high heat dissipation. The wiring can be formed by patterning the metal layer by an ion milling method or an etching method. For example, a wiring pattern made of a platinum thin film or the like can be formed on the surface of aluminum nitride. Furthermore, a protective film made of a thin film such as SiO ₂ may be formed for the purpose of protecting the wiring pattern. Further, a heat radiator such as a metal member insulated from the wiring of the mounting board can be provided in the region where the support member is provided.

(Sealing member 28)
The material of the sealing member 28 filled in the recess 16a is not particularly limited as long as it is translucent. Although it is preferable in terms of durability to use a silicone resin composition, a modified silicone resin composition, etc., an insulating resin composition having translucency such as an epoxy resin composition, a modified epoxy resin composition, an acrylic resin composition, etc. Can also be used. Moreover, sealing members excellent in weather resistance, such as hybrid resins containing at least one of these resins, can also be used. Furthermore, inorganic materials having excellent light resistance such as glass and silica gel can be used. The sealing member 28 is a member whose light transmittance from the light emitting element 20 and the wavelength conversion member 30 is higher than that of the wavelength conversion member 30, and the phosphor content is preferably smaller than that of the wavelength conversion member 30, and more preferably. It is set as the translucent member which does not contain fluorescent substance. Moreover, it is preferable not to contain the scattering agent which scatters light. The upper surface of the sealing member 28 is preferably substantially flat and substantially parallel to the wavelength conversion member 30. As a result, light emitted obliquely from the main surface of the plate-shaped wavelength conversion member 30, light emitted from the side surface, or light emission of the light emitting element 20 that passes outside the wavelength conversion member 30 is high in the sealing member 28. Since it becomes easy to enter at an angle, it is easy to return to the recess 16a and scatter.

  The above embodiments are merely examples, and the present invention is not limited to these. In addition, each element of the present invention is not limited to the case of being configured with the members described in the above embodiment, and a plurality of elements of the invention may be configured with a single member, or one element may be configured with a plurality of members. You can also.

DESCRIPTION OF SYMBOLS 10 Light-emitting device 12 Mounting board 12a, 12b Wiring 14 Side wall 16 Package 16a Recess 18 Scattering surface 20 Light emitting element 28 Sealing member 30 Wavelength conversion member 32 Support substrate 34 Substrate 36 N-type nitride semiconductor layer 38 Light-emitting layer 40 P-type nitride Semiconductor layer 42 n-side electrode 44 p-side ohmic electrode 46 p-side pad electrode 48 protective insulating film 57 translucent member 72 light-emitting semiconductor chip assembly 74 phosphor chip 76 adhesive 78 light-emitting diode chip 80 substrate 82 phosphor layer 84 anode Electrode 86 Cathode electrode 88 Anode lead 90 Cathode lead 90a Cup portion 92 Light emitting device 94 Light scattering agent 96 Protective adhesive

Claims (15)

A container having a recess having an upper surface opened;
A light emitting device that is disposed inside the recess and includes a light emitting layer made of a semiconductor;
A support member made of a translucent material that supports the light emitting element;
Inside the recess, disposed between the light emitting element and the upper surface of the recess, a wavelength conversion member that absorbs part of the light emission of the light emitting element and emits light of a different wavelength,
A translucent member that covers the upper surface of the recess, and a light emitting device that emits light from the light emitting element and light emitted from the wavelength conversion member and emits the light from the upper surface of the recess,
The concave portion has a scattering surface capable of scattering light emission of the light emitting element and light emission of the wavelength conversion member on at least a part of the side surface thereof,
The light emitting element and the wavelength conversion member are separated from the side surface of the recess,
The side surface of the light emitting element is exposed from the wavelength conversion member,
The wavelength conversion member is disposed at least in the middle of a path from the light emitting element toward the upper surface of the recess, and is fixed to the light emitting element side of the translucent member;
The surface of the translucent member on the light emitting element side has an angle β formed by the critical angle θ _C of the surface formed by a line connecting the center of the light emitting layer of the light emitting element and the upper end of the recess and the optical axis of the recess. Is also arranged to be smaller,
The light-emitting device, wherein a surface of the translucent member that faces the light-emitting element side is a scattering surface. The concave portion is filled with a translucent sealing member,
The light-emitting device according to claim 1, wherein the translucent member is a member having a higher thermal conductivity than the sealing member.   An angle β formed by a line connecting the center of the light emitting layer of the light emitting element and the upper end of the recess and the optical axis of the recess is on the surface of the sealing member or the translucent member disposed on the upper surface of the recess. The light-emitting device according to claim 2, wherein β> θc with respect to the critical angle θc of total reflection.   4. The light emitting device according to claim 1, wherein the scattering surface is a surface formed by dispersing phosphor particles in a phosphor holding member having a refractive index different from that of the phosphor particles. 5. apparatus.   The light-emitting device according to claim 1, wherein the scattering surface is a surface formed by dispersing translucent particles in a base material having a refractive index different from that of the particles.   The light emitting device according to claim 1, wherein the wavelength conversion member is disposed only between the light emitting element and an upper surface of the recess.   The light emitting device according to claim 1, further comprising a plate-like wavelength conversion member as the wavelength conversion member.   8. The light emission according to claim 1, wherein the light emitted from the light emitting element is extracted from the upper surface of the concave portion after passing through either the wavelength conversion member or the scattering surface. apparatus.   The container includes a mounting board and a side wall formed on the mounting board, the light emitting element is mounted on the mounting board, and the scattering surface is formed on the side wall. The light-emitting device according to claim 1. The support substrate constituting the support member is made of a material having high thermal conductivity, and the main material of the support substrate has a thermal conductivity of 0.8 [W / mK] or more. Item 10. The light emitting device according to any one of Item 9.   The distance from the light emitting layer of the said light emitting element to the bottom face of the said recessed part is 1/2 or more of the maximum width of the planar direction of the said light emitting layer, The said any one of Claim 1 thru | or 10 characterized by the above-mentioned. Light-emitting device.   The light emitting device according to any one of claims 1 to 11, wherein the light emitting layer of the light emitting element is disposed above one third of the distance from the bottom surface to the top surface of the recess. .   The distance from the light emitting layer of the said light emitting element to the upper surface of the said recessed part is 1/2 or more of the maximum width of the planar direction of the said light emitting layer, The Claim 1 characterized by the above-mentioned. Light-emitting device.   14. The shortest distance from the edge of the light emitting layer of the light emitting element to the side surface of the recess is at least half of the maximum width in the plane direction of the light emitting layer of the light emitting element. The light-emitting device of any one of Claims.   The said support member is comprised by laminating | stacking a support substrate and a 1st wavelength conversion member in order from the bottom face of the said recessed part, The structure of any one of Claim 1 thru | or 14 characterized by the above-mentioned. Light emitting device.

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