JP2013239586A - Semiconductor light-emitting device and lighting appliance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve color unevenness in a semiconductor light-emitting device, which is dependent on a light emission direction.SOLUTION: A semiconductor light-emitting device having a wavelength conversion layer which covers a semiconductor light-emitting element and a light emission surface of the semiconductor light-emitting element comprises a transparent layer 5 provided in a region along an outer periphery of a top face (light emission surface) of a semiconductor light-emitting element 1 and the top face of the light-emitting element including the transparent layer 5 is covered with the wavelength conversion layer 4. Because light emitted from the light emission surface in an inclined manner with respect to a vertical direction passes through the wavelength conversion layer 4 and the transparent layer 5 to be extracted, an optical path through the wavelength conversion layer 4 becomes shorter than a case where the transparent layer 5 does not exist thereby to decrease the occurrence of color evenness caused by a phenomenon that a color of light emitted by the wavelength conversion layer 4 becomes preferential.

Description

  The present invention relates to a semiconductor light-emitting device that can be used for lamps such as street lamps and headlamps, and more particularly to a semiconductor light-emitting device with improved color unevenness.

  Currently used semiconductor light-emitting devices have a structure in which the upper surface of a light-emitting element fixed on a substrate is covered with a phosphor layer, and the light emitted from the light-emitting element and the light emitted from the phosphor layer due to the light. It is configured to generate a desired color, for example, white light by color mixing (for example, a semiconductor light emitting device described in Patent Documents 1 and 2). In such a semiconductor light emitting device, there is a problem that color unevenness is likely to occur due to non-uniformity of the thickness of the phosphor layer, and in order to improve this, Patent Document 2 discloses a film thickness of the phosphor-containing layer. It has been proposed that the thickness is reduced toward the outer edge.

JP 2009-135136 A JP 2010-92897 A

  By the way, the semiconductor light emitting device is used as a light source of various lamps, and depending on the type of the lamp, the light traveling from the light emitting device to the front is used. However, for example, in a headlamp of an automobile, a lamp that extracts light by combining a light emitting device and an optical component such as a reflector or a lens uses light including light that is inclined obliquely from the front direction of the light emitting device as a light source. Therefore, the color tone of light in a direction having an angle with respect to the front surface also becomes a problem.

  If the thickness of the phosphor layer is uniform, the uneven color due to the non-uniform thickness is eliminated for the light in the front direction, but the light emitted from the light emitting element is transmitted through the phosphor layer for the light in the oblique direction. Since the optical path becomes longer as the angle from the front increases, color unevenness due to the light emission direction occurs. For example, in a semiconductor light emitting device that emits white light by a combination of a light emitting element that emits light in the blue to ultraviolet region and a phosphor that emits yellow light, the light in the front direction is white but the light that travels to the periphery is phosphor. The light from becomes dominant and yellowish.

  When such a light emitting device is used for a headlamp, not only a decorative problem but also a problem that the light illuminating the road surface becomes yellow and difficult to see. As described in Patent Document 2, when the thickness of the phosphor layer itself is reduced toward the periphery, the color unevenness depending on the emission direction is improved to some extent. However, since the phosphor particles generally have a large specific gravity relative to the resin in which they are dispersed, they often sink in the resin layer and are unevenly distributed in the lower layer. For this reason, just adjusting the film thickness of the resin layer containing the phosphor does not adjust the film thickness of the phosphor layer, but is insufficient to improve the color unevenness depending on the emission direction.

  Accordingly, an object of the present invention is to improve color unevenness depending on the emission direction in a semiconductor light emitting device, and in particular to obtain white light without color unevenness in a lamp combined with a reflector and a lens.

  In order to solve the above-described problems, a semiconductor light emitting device of the present invention is provided with a transparent layer in a region along the outer periphery of a semiconductor light emitting element having an upper surface as a light emitting surface, and the upper surface of the light emitting element including the transparent layer has a wavelength The structure is covered with a conversion layer.

  That is, the semiconductor light emitting device of the present invention includes a light emitting element having a light emitting surface on the upper surface, a transparent layer disposed on the upper surface of the light emitting element along the outer periphery of the light emitting element, an upper surface of the transparent layer, and an upper surface of the light emitting element. And a wavelength conversion layer covering a region where the transparent layer is not disposed.

  The cross-sectional shape of the transparent layer can be an arbitrary shape such as a triangle or a quadrangle. In addition, the transparent layer may be formed by coating along the outer periphery of the upper surface of the light emitting element, or may be disposed in advance as a rod.

  The portion of the wavelength conversion layer surrounded by the transparent layer may be flat or dome-shaped.

  The lamp of the present invention is a lamp including a light source that emits light radially and an optical element that emits light having a predetermined light distribution characteristic by reflecting and collecting light from the light source. The semiconductor light emitting device of the present invention is used as the light source.

  According to the present invention, the transparent layer functions to adjust the length of an optical path through which light emitted at an angle with respect to the front surface of the light emitting element passes through the wavelength conversion layer. Can be prevented from being largely dominated by the color of light from the wavelength conversion layer, that is, color unevenness is increased.

1 is a top view showing a semiconductor light emitting device according to a first embodiment. FIG. 2 is a side sectional view of the semiconductor light emitting device of FIG. 1. Sectional drawing which shows an example of the light emitting element with which the semiconductor light-emitting device of this invention is provided. It is a figure explaining the function of a transparent layer, (a) shows the case where the transparent layer 5 is provided, (b) shows the case where the transparent layer 5 is not provided. (A)-(d) is a figure which shows an example of the manufacturing process of the semiconductor light-emitting device of 1st embodiment. The sectional side view which shows the semiconductor light-emitting device of 2nd embodiment. It is a figure which shows the semiconductor light-emitting device of 3rd embodiment, (a) is a top view, (b) is a sectional side view. Sectional drawing which shows embodiment of the lamp of this invention. The figure which shows the course of the light in the lamp of FIG. The figure explaining the measurement of the luminescent color in an Example. The graph which shows the measurement result of an Example and a comparative example. Sectional drawing of the light-emitting device of a comparative example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First embodiment>
FIG. 1 is a top view showing a first embodiment of a semiconductor light emitting device 10 of the present invention, and FIG. 2 is a side sectional view. The semiconductor light emitting device 10 includes a semiconductor light emitting element (hereinafter referred to as a light emitting element) 1, a resin layer 2 including a phosphor 2a, a substrate 3 on which the light emitting element 1 is fixed, and a transparent layer made of a material that transmits light. 5 is provided.

  The type of the light-emitting element 1 is not particularly limited as long as the light-emitting element 1 emits light from the upper surface. A face-up element having two electrode terminal portions formed on the upper surface, and a flip having two electrode terminal portions formed on the lower surface A known light emitting device such as an MB (metal bond) device in which two electrode terminal portions are formed on the upper surface and the lower surface can be used. FIG. 3 shows an example of the MB element. In the light emitting element 1, a semiconductor epitaxial layer (an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer) is sequentially formed on a transparent substrate (not shown) such as sapphire, and the epitaxial layer is made of an opaque material such as Si or Ge. The sapphire substrate is peeled off after being bonded to the upper surface of a simple element substrate 11 via a metal film 12 composed of a plurality of metal layers including a mirror layer and a protective layer. A cathode electrode 14 is formed by depositing a metal such as Au, Ag, Al or the like on the n-type semiconductor layer of the epitaxial layer 13 exposed on the front surface side by sputtering or the like, and then patterning, and Pt is formed on the back surface of the element substrate 11. The anode electrode 15 is formed by vapor-depositing a metal such as. In the light emitting element 1, the upper surface on which the cathode electrode 14 is formed is mainly a light emitting surface.

  The substrate 3 is a mounting substrate on which a wiring pattern is formed, and the anode electrode 15 formed on the lower surface of the light emitting element 1 is electrically connected by being fixed to the substrate 3 with a conductive adhesive or the like. The cathode electrode 14 is electrically connected to an electrode pad (not shown) formed on the substrate 3 by a conductive wire (not shown).

  The resin layer 2 is a layer in which phosphor particles 2a are dispersed in a transparent resin such as silicone or epoxy resin, and is formed so as to cover the upper surface of the light emitting element 1 on which the transparent layer 5 and the transparent layer 5 described later are not formed. The The phosphor is a wavelength conversion material that emits light of a predetermined wavelength by light emitted from the light emitting element 1, and a predetermined material is selected and used in combination with the light emitting element 1. As an example, when the light-emitting element 1 is a light-emitting element that emits blue to violet light such as InGaN, GaN, or AlGaN, a phosphor such as YAG or SiAlON is used, and thus white light can be extracted. The phosphor is usually used in the form of particles.

  The resin layer 2 is formed by dropping a phosphor particle 2a dispersed in a resin by potting or the like. At this time, although it varies depending on the ratio of the phosphor particles to the resin and the presence or absence of thixotropy of the resin, in the case of a resin not imparted with thixotropy, the phosphor particles settle on the light emitting element 1 side and fluorescent on the light emitting element 1 side. An area where body particles become highly concentrated is born. In the present embodiment, a region in which the phosphor particles have a high concentration (specifically, the proportion of the phosphor particles in the region is 80% by volume or more) is referred to as a phosphor layer 4, and the thickness of the layer 4 is the phosphor. Let it be the thickness of the layer. Although the thickness of the fluorescent substance layer 4 is not specifically limited, Usually, it is about 1/3 to 2 times the thickness of the light emitting element 1, and can be adjusted with content of the fluorescent substance particle of an element.

  The transparent layer 5 is a layer for adjusting the length of the optical path through which the light emitted from the upper surface of the light emitting element 1 passes through the resin layer 2 (phosphor layer 4). Formed. As a material constituting the transparent layer 5, a transparent and heat resistant resin such as silicone or epoxy resin, or glass can be used. The resin constituting the transparent layer 5 may be the same as or different from the resin constituting the resin layer 2, but the adhesiveness with the resin layer 2 can be enhanced by using the same resin.

  In this embodiment, the transparent layer 5 has a shape in which the outer peripheral side of the light emitting element 1 is thickest and the thickness is thinned inward (for example, the shape of the cross section perpendicular to the element surface is substantially triangular) Is thinner than the thickness of the phosphor layer 4 and is covered with the phosphor layer 4. The width of the region for forming the transparent layer 5 and the thickness of the transparent layer 5 (the thickness of the maximum thickness portion) are appropriately determined according to the size of the element 1 (vertical and horizontal size), the thickness of the phosphor layer 4, and the like. .

  The function of the transparent layer 5 will be described with reference to FIG. 4A shows a case where the transparent layer 5 is provided, and FIG. 4B shows a case where the transparent layer 5 is not provided. In the figure, Dp and Wp represent the thickness and width of the phosphor layer 4, respectively, and Dt and Wt represent the thickness (maximum height) and width of the transparent layer 5, respectively.

  The light emitting element 1 emits light from the entire upper surface, and proceeds radially from a plane including the upper surface toward the upper side. Here, when the direction perpendicular to the upper surface is 0 °, and light emitted from the upper surface center 1C is considered as a representative of light emitted from the upper surface, when there is no transparent layer 5 (FIG. 4B), the direction is 0 °. The path through which light passes through the phosphor layer is the shortest, and the path (optical path length) through the phosphor layer becomes longer as the angle approaches 90 °. Thereby, in the light with a large angle, the ratio of the light from a fluorescent substance layer becomes high, and becomes light with strong yellowishness. When light emission from the entire top surface of the light emitting element is considered, light at a certain angle θ is a combination of light traveling from the entire surface in the same direction (angle θ). Here, a part of the light emitted from the light emitting element 1 (light indicated by a dotted line) is emitted from the side surface of the phosphor layer. In this case, the optical path length is shortened, but the optical path of the light (light indicated by the solid line) emitted from the emission surface. Since the length increases with an increase in θ, the overall color remains yellowish as the angle approaches 90 °.

  When such light is viewed from the top surface of the light emitting element, light in a relatively small angle range is seen, so that there is almost no change in color, that is, light with no color unevenness. However, in a lamp that combines a reflector and a lens and uses a lot of light with a large angle among light emitted radially from a light emitting element, a change in color due to a change in the optical path length passing through the phosphor layer appears strongly. .

  On the other hand, as shown in FIG. 4A, when the transparent layer 5 is disposed on the upper surface of the light emitting element, the angle determined by the thickness Dp and the width Wp of the phosphor layer is θmax (= arc (Wp / 2Dp). In this case, the optical path length of the light emitted from the center 1C of the light emitting element 1 becomes maximum at the angle θmax, and the light from the entire upper surface of the light emitting element 1 is centered on the light emitting element 1 to the center side end 5A of the transparent layer 5. The light from the region (light indicated by the solid line) passes through the maximum optical path length, but the light from the other region (light indicated by the alternate long and short dash line and the dotted line) is phosphor due to the presence of the transparent layer 5 The light path in the layer 4 is shortened or emitted from the side surface of the transparent layer 5 without passing through the phosphor layer 4, and the color (blue or purple) of the light emitting element 1 itself becomes dominant light. The yellow light passing through the maximum optical path length and the color of the light emitting element are mixed. White light.

  As can be seen from the function of the transparent layer 5 described above, when the volume of the transparent layer 5 is too large, the color of light emitted from the light-emitting element 1 becomes dominant and bluish, and the volume of the transparent layer 5 increases. When it is too small, the color of the light emitted from the phosphor layer 4 becomes dominant and yellowing becomes strong. Therefore, as described above, the size of the transparent layer 5 is preferably determined so as to obtain a desired color in consideration of the size of the light emitting element 1 and the thickness of the phosphor layer 4. As an example, the width Wt of the transparent layer 5 is preferably 0.4 or less, more preferably 0.25 or less, preferably 0.1 or more, when the shorter width of the light emitting element 1 is 1. Preferably it is 0.15 or more. The thickness (maximum height) Dt of the transparent layer 5 is preferably 0.1 or more when the thickness Dp of the phosphor layer 4 is 1, and is 1/10 to 1/1 of the width Wt of the transparent layer 5. Preferably it is about 5.

  Note that light with a small angle among light emitted from the light emitting element tends to increase the color (blueness) of light from the light emitting element 1 at the outer peripheral portion due to the transparent layer 5 on the outer periphery. Since the transparent layer 5 of the embodiment has a shape in which the thickness is large on the outer peripheral side and becomes thinner toward the center side, such a color change toward the outer periphery of the light emitting element can be reduced.

  Next, a method for manufacturing the semiconductor light emitting device of this embodiment will be described. FIG. 5 shows an example of the manufacturing process.

  First, the light emitting element 1 is mounted on the substrate 3 so that the light extraction surface (upper surface of the epitaxial layer 13) is the upper surface, and the electrode (not shown) is connected to the electrode pad of the substrate 3 (FIG. 5A). In the illustrated example, the epitaxial layer 13 of the light-emitting element 1 is slightly smaller in size than the element substrate 11 and the metal film (mirror layer and protective layer) 12 disposed on the element substrate 11, and there is a region where the metal film 12 is exposed in the periphery. Is formed.

  Next, the transparent layer 5 is formed along the periphery of the epitaxial layer 13 where the metal film 12 is exposed and the outer periphery of the upper surface of the epitaxial layer 13 (FIG. 5B). The transparent layer 5 can be formed to have an arbitrary thickness by, for example, applying a transparent resin imparted with thixotropy using a known method such as potting or printing. At that time, the thickness can be inclined by decreasing the coating width in order from the bottom, and the inclination angle can be adjusted by adjusting the ratio of changing the coating width of each layer. Since the transparent layer 5 is formed on the upper surface of the epitaxial layer 13 in the form of a bank along the outer periphery thereof, it also functions as a dam frame when the resin layer 2 is formed in the next step.

  Next, an uncured transparent resin in which the phosphor particles 2a are dispersed is injected into the dam frame formed of the transparent layer 5 by potting or the like (FIG. 5C). In general, when the content of the phosphor particles is large, the viscosity of the transparent resin is increased and the thickness of the resin layer (phosphor layer) 2 is likely to be non-uniform, so the phosphor content is about 10-50. To do. In this case, the phosphor particles settle in the process of curing the transparent resin to form a high-concentration region (phosphor layer 4) on the light emitting element 1 side, and the upper part has a dome shape formed by the surface tension of the resin. By curing the resin layer 2, a semiconductor light emitting device as shown in FIG. 5D is finally obtained.

  As described above, the semiconductor light emitting device according to the present embodiment emits light radially from the light emitting element by disposing the transparent layer made of a material that transmits light in the region along the outer periphery of the upper surface of the light emitting element. Of the light, the light having a large angle with respect to the vertical direction can prevent the light from the phosphor layer from being dominant, and suppress the occurrence of color unevenness depending on the light emission angle.

  In the semiconductor light emitting device of the present embodiment, the transparent layer has a shape in which the thickness becomes thinner from the outer peripheral side toward the inner side, so that the color change accompanying the increase of the light emission angle can be made smooth. Furthermore, since the transparent layer can function as a dam frame when the resin layer containing the phosphor particles is formed, it is not necessary to separately provide a dam frame or the like, and the resin layer forming process can be facilitated.

  2 and 5 show the case where the transparent layer 5 has a substantially triangular cross section, but the inclined portion may be a shape that protrudes outside or inside the triangle instead of a straight line. .

<Second embodiment>
The semiconductor light emitting device of this embodiment is different from the first embodiment in the shape of the transparent layer. Other elements are the same as in the first embodiment.

  FIG. 6 shows a side cross section of the semiconductor light emitting device of this embodiment. In FIG. 6, the same elements as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in the figure, in this semiconductor light emitting device, a light emitting element 1, a transparent layer 50, and a resin layer 2 are formed on a substrate 3. Also in this embodiment, the light emitting element 1 has a region in which the epitaxial layer 13 is smaller than the underlying element substrate 11 and the metal film 12 and the metal film 12 is exposed around the epitaxial layer 13.

  The transparent layer 50 is formed along the outer periphery of the portion of the metal film 12 and the upper surface of the epitaxial layer 13. The thickness of the transparent layer 50 in the epitaxial layer 13 is substantially constant, and the upper surface of the transparent layer 50 is flat (that is, parallel to the light emitting surface of the element 1). Similarly to the transparent layer 5 of the first embodiment, the transparent layer 50 of the present embodiment can be formed by recoating the resin constituting the transparent layer, and the thickness can be adjusted by adjusting the number of layers to be overcoated. Can be adjusted. Thereafter, the resin layer 2 is formed by potting an uncured resin in which phosphor particles are dispersed inside the transparent layer 50, as in the first embodiment.

  In the light emitting device of the present embodiment, since the thickness of the transparent layer 50 is constant, the transparent layer 50 and the transparent layer 50 are not provided for light perpendicular to the top surface of the light emitting element (0 °) or light having a small angle. Although it is easy to produce a color difference between the portions, if the thickness is the same as that of the transparent layer 5 of the first embodiment, the color change is suppressed at a stage where the light emission angle is smaller than that of the first embodiment. An effect is obtained.

  In FIG. 6, the transparent layer 50 has a substantially rectangular cross section. However, a trapezoidal shape in which one side of the transparent layer 50 is inclined may be formed, and the inclined side may have a shape protruding outward or inward of the trapezoid. It is also possible. Also in this embodiment, the shape of the resin layer 2 may be flat instead of a dome shape, or the resin layer 2 may be a phosphor layer 4 in which phosphor particles are uniformly dispersed.

<Third embodiment>
The semiconductor light emitting device of this embodiment is characterized in that a transparent rod (bar-shaped member) is used as the transparent layer. The transparent layer of the semiconductor light emitting device of the first and second embodiments is formed by repeatedly applying a transparent resin. In this embodiment, a transparent rod previously molded into a predetermined shape is used, and the light emitting element 1 is used. A transparent layer is obtained by sticking to the surface. FIG. 7 shows a top view and a side sectional view of the semiconductor light emitting device of this embodiment. In the figure, the same elements as those in the first embodiment are denoted by the same reference numerals.

  As the transparent rod 7, a transparent material such as glass can be used in addition to a resin such as a silicone resin and an epoxy resin. When a resin having a refractive index equal to or lower than the resin of the resin layer 2 is used, no interface reflection occurs between the resin layer and the transparent layer, but a material having a higher refractive index than the resin of the resin layer 2 is used. When using, it is preferable to process such as roughening the surface or forming a shape that prevents interface reflection. The shape may be a shape whose thickness changes from the outer peripheral side to the inner side as in the first embodiment, or may be a shape having a flat upper surface as in the second embodiment.

  As the adhesive 8 for sticking the transparent rod 7 onto the light emitting element 1, a silicone-based or epoxy-based adhesive having heat resistance and light transmission can be used. The thickness of the adhesive 8 is adjusted so that the total thickness of the transparent rods 7 becomes the designed thickness of the transparent layer. The design thickness of the transparent layer is slightly thinner than the thickness of the phosphor layer. Thus, since the phosphor covers the upper surface of the transparent layer, it is possible to prevent only the outer peripheral portion of the element from shining blue when light emission from the upper surface is seen.

  According to the semiconductor light emitting device of this embodiment, the degree of freedom of the material of the transparent layer is high, the step of applying the transparent layer a plurality of times to obtain a desired shape can be omitted, and the manufacturing process can be simplified. it can.

  As mentioned above, although each embodiment of the semiconductor light-emitting device of this invention was described, the semiconductor light-emitting device of this invention is not limited to embodiment mentioned above, A various change is possible. For example, FIG. 2, FIG. 6 and FIG. 7 show a resin layer 2 having a dome shape and a high-concentration phosphor layer formed at the bottom, but the phosphor particles are almost uniform in the resin layer. The resin layer may be dispersed in the resin layer, and the shape of the resin layer may be not only a dome shape but also a resin layer having a flat upper surface.

  Further, the size of the transparent layer shown in the above description is merely an example, and can be changed according to the emission angle of light to be used.

  Next, an embodiment of the lamp of the present invention will be described. FIG. 8 shows a sectional structure of a headlamp as an embodiment of the lamp of the present invention.

  The headlamp includes a lamp chamber 80 including a front lens 81 and a housing 83, and an optical unit 90 accommodated in the lamp chamber. The optical unit 90 is a semiconductor element of the present invention as a main element. The light source unit 100 which consists of a light-emitting device, the reflector 91 by which 1 thru | or several reflective surfaces 91a-91c were formed in the inner surface, and the projection lens 95 are provided. The light source unit 100 may employ any of the light emitting devices of the above-described embodiments, and is fixed to the upper surface of the mount plate 93 so that the upper surface thereof faces upward. The projection lens 95 is fixed to one end of a cylindrical lens holder 97, and the other end of the lens holder 97 is connected to the reflector 91. A connecting portion between the lens holder 97 and the reflector 91 is provided with a shade 99 for forming a predetermined light distribution pattern.

  The reflector 91 reflects the light emitted from the light source unit 100 and directs it toward the projection lens 95. In the embodiment shown in FIG. 8, a plurality of elliptical reflecting surfaces 91a, 91b, 91c are formed. The respective focal positions are designed so that the light emitted from the unit 100 is directed to the projection lens 95. Specifically, as shown in FIG. 9, the reflection surface 91 a is installed so as to cover the rear side from the upper side of the light source unit 100, reflects light traveling from the upper side to the rear side of the light source unit 100, and faces the projection lens 95. Dodge. The reflective surface 91b is installed in front of the light source unit 100 continuously to the reflective surface 91a, reflects light traveling forward from the light source unit 100, and is directed toward the projection lens 95 via the reflective surface 91c installed below the reflective surface 91b. Dodge. The light reflected by the reflecting surfaces 91 a and 91 c of the reflector 91 is collected at a focal position near the end of the shade 99, and then extracted by the projection lens 95 as parallel light having a predetermined light distribution pattern.

  Due to the design of the reflector 91 described above, most of the light emitted from the light source unit 100 in a hemispherical shape is efficiently utilized from 0 ° to an angle close to 90 °, and light having a large angle is used as the projection lens 95. The light is emitted from the vicinity of the center. Therefore, when a conventional light-emitting device having a large color unevenness angle dependency is used as a light source unit, the light emitted from the projection lens 95 is greatly affected by the color unevenness. It becomes yellowish light. On the other hand, the lamp of the present invention can obtain white or near-white light for light emitted from the light source unit 100 at a large angle (angle with respect to the vertical direction), and can realize a lamp without color unevenness. .

  8 shows a lamp that employs a reflector having a plurality of reflecting surfaces. However, the reflecting surface provided in the reflector is not limited to the illustrated one. For example, a single reflecting surface that covers the light source unit 100 is provided. A well-known structure, such as a lamp that employs the provided reflector, can be employed.

Examples of the semiconductor light emitting device of the present invention will be described below.
A 1 mm square light emitting element (blue light emission) was mounted on a ceramic substrate. A thixotropic silicone resin is applied to a region along the outer periphery of the epitaxial layer of the light-emitting element and the outer periphery of the upper surface thereof using a coating device for a small amount, and finally, as shown in FIG. A transparent dam frame having a cross section perpendicular to the element surface and having a substantially right triangle and a width of 0.20 to 0.25 mm and a height of 0.03 to 0.05 was formed. After curing the silicone resin of the dam frame, a silicone resin (phosphor content: 40% by weight) containing yellow light-emitting phosphor particles (YAG phosphor) in the region of the upper surface of the element surrounded by the dam frame is used. When the long side is 1 and the resin height is dropped between 0.2 and 0.4 (preferably 0.3), it is cured to form a phosphor layer, and light emission as shown in FIG. The device was manufactured. The height of the phosphor layer of this light emitting device was 0.16 to 0.18 mm.

  The light emission color at each angle was measured in a state where the light emitting device manufactured as described above was energized to emit light. As shown in FIG. 10, the emission color is measured from −80 ° to + 80 ° when the direction passing through the center of the upper surface of the light emitting element and the direction perpendicular to the upper surface of the light emitting element is 0 ° and the direction parallel to the upper surface is 90 °. The Y value of the CIE color system was measured by a method based on JIS Z 8723 while moving the goniometer-mounted spectroradiometer (OL 770 spectroradiometry system: KL Buoy Co., Ltd.) 11. Such a measurement of the luminescent color is performed in a first direction (measurement position 1) passing through the center of the light emitting element and a second direction (measurement position 2) perpendicular thereto, and an average value thereof is taken as a measurement value. The difference from the measured value of 0 ° was determined. The result is shown by a solid line in FIG.

  As a comparative example, without providing a dam frame, a phosphor layer was formed by potting a phosphor particle-containing silicone resin on the upper surface of a light emitting device similar to the example, and a light emitting device as shown in FIG. 12 was manufactured. Also for this light emitting device, the emission color (Y value of the CIE color system) in the range from −80 ° to + 80 ° was measured in the same manner as in the example. The result is shown by a dotted line in FIG.

  As can be seen from the results shown in FIG. 11, in the example, the color is about 1/4 of the chromaticity difference of the comparative example (the light emitting device in which the phosphor layer is formed without providing the dam frame) until the angle is close to 70 °. It was shown that the angle difference can be suppressed and the angle dependency of the light emitting element can be greatly improved.

  ADVANTAGE OF THE INVENTION According to this invention, the angle dependence of the hue of the light (light with a large inclination angle) which goes to the direction inclined from the front direction of the light-emitting device can be suppressed, and it is especially a lamp using light with a large inclination angle. When applied, color unevenness due to angle dependency can be reduced. Thereby, an easy-to-see lamp can be provided.

DESCRIPTION OF SYMBOLS 1 ... Light emitting element, 2 ... Resin layer, 2a ... Phosphor particle (wavelength conversion material), 3 ... Substrate, 5, 50 ... Transparent layer, 7 ... Transparent rod (bar shape) Members) 10, 100 ... semiconductor light emitting device, 11 ... element substrate, 12 ... metal film, 13 ... epitaxial layer, 80 ... lamp chamber, 81 ... front lens, 83. ..Case, 90 ... optical unit, 91 ... reflector, 93 ... mount plate, 95 ... projection lens, 97 ... lens holder.

Claims (9)

  A light emitting device having a light emitting surface on an upper surface, a transparent layer disposed along an outer periphery of the light emitting device on the upper surface of the light emitting device, and an upper surface of the transparent layer and the transparent layer on the upper surface of the light emitting device are disposed. And a wavelength conversion layer that covers a region that is not formed. The semiconductor light emitting device according to claim 1,
The transparent layer has a shape in which a cross section perpendicular to the upper surface of the light emitting element is thickest on the outer peripheral side and becomes thinner toward the inside. The semiconductor light-emitting device according to claim 1 or 2,
The wavelength conversion layer includes a phosphor and a resin that disperses the phosphor, and has a high-concentration region formed by sedimenting the phosphor on the light emitting element side. A semiconductor light-emitting device according to any one of claims 1 to 3,
The said wavelength conversion layer is a dome shape which thickness increases toward the center part from the outer peripheral side, The semiconductor manufacturing apparatus characterized by the above-mentioned. The semiconductor light emitting device according to claim 1,
The transparent layer has a quadrangular cross section perpendicular to the top surface of the light emitting element. A semiconductor light emitting device according to any one of claims 1 to 5,
The semiconductor light-emitting device, wherein the transparent layer is formed by applying a transparent resin. A semiconductor light emitting device according to any one of claims 1 to 5,
The said transparent layer is formed by sticking the rod-shaped member which consists of a transparent material to the said light emitting element, The semiconductor light-emitting device characterized by the above-mentioned. A semiconductor light emitting device according to any one of claims 1 to 7,
The light-emitting element includes an element substrate and a stacked structure formed on the element substrate and including an epitaxial layer as an uppermost layer.
The semiconductor light emitting device, wherein the transparent layer is formed so as to cover a part of the laminated structure. A lamp comprising: a light source that emits light radially; and an optical element that emits light having a predetermined light distribution characteristic by reflecting and collecting light from the light source,
A lamp comprising the semiconductor light-emitting device according to claim 1 as the light source.

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