Semiconductor light-emitting device

Abstract

In this light-emitting device for wavelength conversion of emitted light by means of a phosphor-containing resin layer, the angle dependency of the chromaticity of the emitted light is reduced.　A frame body is provided so as to surround a light-emitting element placed on an upper surface of a substrate, an upper surface of the light-emitting element is covered, and the space from a side surface of the light-emitting element to the frame body is sealed by a phosphor-containing sealing member. A light diffusion material is dispersed in the phosphor-containing sealing member, and light emitted from the light-emitting element and fluorescence emitted from particles of the phosphor are mixed and emitted from the surface of the phosphor-containing sealing member. The differences ΔCx, ΔCy between the chromaticities Cx and Cy of light emitted obliquely from the surface of the phosphor-containing sealing member and the chromaticities Cx, Cy of light emitted in the normal direction, respectively, are 0.006 or less, where Cx and Cy are coordinate values of the horizontal axis and the vertical axis, respectively, of a chromaticity diagram (CIE1931).

Description

Semiconductor light-emitting device

[0001] The present invention relates to a semiconductor light emitting device having a structure in which the top and side surfaces of a semiconductor light emitting element are sealed with a resin containing a phosphor and a diffusing material.

[0002] Patent Document 1 discloses that a light emitting device in which the upper surface of a light emitting element provided on a substrate is sealed with resin has a difference in chromaticity between light emitted in a frontal direction and light emitted in an oblique direction, and that this difference in chromaticity causes uneven illumination. In the invention of Patent Document 1, a diffusing material is mixed into the resin placed on the upper surface of the light emitting element, thereby suppressing the difference between the maximum and minimum values ​​of chromaticity y in the measurement angle range of -60 degrees to 60 degrees to a predetermined value or less.

[0003] Furthermore, Patent Document 2 discloses a package in which a frame-shaped resin portion is provided on a lead frame, a light-emitting element is mounted on the lead frame, and resin is poured into the inside of the frame-shaped resin portion, thereby sealing the top and side surfaces of the light-emitting element with resin.

[0004] JP 2023-67740 A JP 2012-182215 A

[0005] The technology of Patent Document 1 is effective in suppressing the difference between the maximum and minimum values ​​of chromaticity y in a light-emitting device that emits monochromatic light only from the top surface of the light-emitting element. However, in a light-emitting device that emits white light by dispersing phosphor in resin and uses light emitted from the top and side surfaces of the light-emitting element, it is difficult to suppress chromaticity unevenness.

[0006] The reason is that in the case of a light-emitting device in which light is emitted from the top surface and the side surface of the light-emitting element, the optical path length that light emitted from the top surface of the light-emitting element and heading directly upward passes through the phosphor-containing resin layer is different from the optical path length that light emitted from the side surface of the light-emitting element and heading toward the top surface of the phosphor-containing resin layer passes through the resin layer. The longer the optical path length through the phosphor-containing resin layer, the greater the ratio of fluorescence to excitation light, so the light emitted from the side surface of the light-emitting element has a higher ratio of fluorescence to excitation light, causing chromaticity unevenness.

[0007] 8(a) and 8(b), the directional characteristics of the light emitted from the light-emitting element are Lambertian radiation, whereas fluorescence is emitted in all directions from each phosphor particle. Therefore, even if a diffusing material is added to the phosphor-containing resin, it is difficult to make the directional characteristics of the additively mixed light emitted from the upper surface of the phosphor-containing resin layer match between the fluorescence and the excitation light, which causes chromaticity unevenness.

[0008] The object of the present invention is to reduce the angular dependence of the chromaticity of the additively mixed emitted light in a light emitting device having a structure in which light emitted from the top and side surfaces of a light emitting element is wavelength converted using a phosphor-containing resin layer.

[0009] To achieve the above object, the present invention provides a semiconductor light-emitting device comprising a substrate, a light-emitting element mounted on the upper surface of the substrate, a frame surrounding the light-emitting element, and a phosphor-containing sealing member. The phosphor-containing sealing member contains phosphor particles, covers the upper surface of the light-emitting element, and fills the space from the side of the light-emitting element to the frame. A light diffusing material is dispersed in the phosphor-containing sealing member, and the light emitted from the light-emitting element and the fluorescence emitted from the phosphor particles are mixed. The chromaticities Cx and Cy of the light emitted obliquely from the surface of the phosphor-containing sealing member differ from the chromaticities Cx and Cy of the light emitted perpendicularly from the surface of the phosphor-containing sealing member by differences ΔCx and ΔCy of 0.006 or less, respectively, where Cx and Cy are the coordinate values ​​on the horizontal and vertical axes of the chromaticity diagram (CIE 1931), respectively.

[0010] According to the present invention, in a light emitting device having a structure in which light emitted from the top and side surfaces of a light emitting element is wavelength converted by a phosphor-containing resin layer, the angle dependency of the chromaticity of the emitted light can be reduced.

[0011] (a) to (c) are a top view, a side view of the long side, and a side view of the short side of the semiconductor light-emitting device 1 according to the first embodiment of the present invention; (d) and (e) are cross-sectional views taken along lines A-A and B-B; and (f) is a top view with the sealing resin removed. (a) to (d) are top views, side views of the long side, side views of the short side, and A-A cross-sectional views of the lead electrodes 10, 20 and the frame 40. (a) is a graph showing the chromaticity in the longitudinal direction of the semiconductor light-emitting element of the example; (b) is a graph showing the chromaticity in the longitudinal direction of the semiconductor light-emitting element of Comparative Example 1; and (c) is a graph showing the chromaticity in the longitudinal direction of the semiconductor light-emitting element of Comparative Example 2. This is a schematic diagram showing the emission angle range of the semiconductor light-emitting device according to the first embodiment. This is a flowchart showing the manufacturing process of the semiconductor light-emitting device according to the first embodiment. (a) to (c) are diagrams illustrating the manufacturing process of the semiconductor light-emitting device according to the first embodiment. (a) to (c) are diagrams illustrating the manufacturing process of the semiconductor light-emitting device 1 according to the first embodiment. 1A is a diagram illustrating the directional characteristics of light emitted by a light-emitting element of a semiconductor light-emitting device, and FIG. 1B is a diagram illustrating the directional characteristics of fluorescence emitted by phosphor particles.

[0012] An embodiment of the present invention will be described with reference to the drawings.

[0013] First, the structure of the semiconductor light-emitting device 1 of this embodiment will be described with reference to Figures 1 and 2. Figures 1(a) to 1(c) are a top view, a side view of the long side, and a side view of the short side of the semiconductor light-emitting device 1, Figures 1(d) and 1(e) are cross-sectional views taken along lines A-A and B-B, and Figure 1(f) is a top view with the sealing resin removed. Figures 2(a) to 2(d) are top views, side views of the long side, side views of the short side, and a cross-sectional view taken along line A-A of the lead electrodes 10 and 20 and the frame 40.

[0014] The semiconductor light-emitting device 1 includes a pair of flat lead electrodes 10, 20, a frame 40, a light-emitting element 50, a light-reflective sealing member 70, and a phosphor-containing sealing member 80. The frame 40 is shaped like a bank, surrounding the lead electrodes 10, 20 and filling the gap 30 between them. The light-emitting element 50 is bonded via an adhesive member 60 to the upper surface of the lead electrode 20 on one side of a recess defined by the inner surface of the frame 40 and the upper surfaces of the lead electrodes 10, 20. The light-reflective sealing member 70 is embedded from the periphery of the light-emitting element 50 to the inner surface of the frame 40. The phosphor-containing sealing member 80 covers the light-emitting element 50 and the reflective sealing member, filling the recess. Bonding wires 90, 91 are also provided, connecting a pair of upper electrodes (not shown) of the light-emitting element 50 to the lead electrodes 10, 20, respectively. The semiconductor light-emitting element 1 also includes a protective element 51 adhered via a conductive adhesive to the lead electrode 10 on the side to which the light-emitting element 50 is not adhered, and a bonding wire 93 connecting the upper electrode of the protective element 51 to the lead electrode.

[0015] The frame 40 is rectangular, is mounted on the lead electrodes 10, 20, and covers the long-side side surfaces of the lead electrodes 10, 20. The frame 40 fills steps 40a (see FIG. 1( e)) on the long-side side surfaces of the lead electrodes 10, 20, thereby preventing separation between the lead electrodes 10, 20 and the frame 40. The resin constituting the frame 40 also fills the gap 30 between the lead electrodes 10, 20.

[0016] A portion of the upper surfaces of the pair of lead electrodes 10 and 20 between the inner surface of the frame 40 and the light emitting element 50 is covered with a light-reflective sealing member 70 .

[0017] The space from the side surface of the light-emitting element 50 to the inner surface of the frame 40 is filled with a phosphor-containing sealing member 80, which is a resin in which phosphor particles PP and a light diffusing material PD are dispersed. The phosphor-containing sealing member 80 covers the upper surface of the light-emitting element 50 and the upper surface of the light-reflective sealing member 70, and has a substantially flat surface. The height of the surface of the phosphor-containing sealing member 80 matches the height of the frame 40 (the upper end of the frame 40 in FIG. 1( d )).

[0018] The light-reflective sealing member 70 is made of a material that reflects the light emitted from the light-emitting element 50 and the fluorescence emitted by the phosphor particles PP of the phosphor-containing sealing member 80 when excited by the light from the light-emitting element 50. For example, the light-reflective sealing member 70 is made of a resin in which light-reflective particles are dispersed.

[0019] The light-reflective sealing member 70 does not contact the side surfaces of the light-emitting element 50. The thickness of the light-reflective sealing member 70 is formed to increase with increasing distance from the light-emitting element 50, and the upper surface of the light-reflective sealing member 70 is inclined. The inclined upper surface of the light-reflective sealing member 70 reflects light emitted from the side surfaces of the light-emitting element 50 upward.

[0020] As described above, the light diffusing material PD is dispersed in the phosphor-containing sealing member 80, and the light (e.g., blue light) emitted from the light emitting element 50 and the fluorescence (e.g., yellow light) emitted from the phosphor particles PP are additively mixed and diffused, and then emitted from the surface of the phosphor-containing sealing member 80. In other words, the semiconductor light emitting device 1 is a light emitting device that emits mixed light (e.g., white light) containing light of two or more colors with different hues.

[0021] The light diffusing material PD is yttrium phosphate particles with a particle size that is primarily responsible for geometrical optical scattering. The particle size of the light diffusing material PD is preferably 1 μm or more, at which point geometrical optical scattering characteristics become dominant in the visible light band. Furthermore, the particle size of the light diffusing material PD is smaller than that of the phosphor particles PP, and scatters the light emitted by the phosphor particles PP to reduce color unevenness. Furthermore, the particle size (median particle size) of the phosphor particles PP, which use blue light (approximately 445 nm) as excitation light, is preferably approximately 5 μm to 50 μm, which provides good absorption efficiency for the excitation light. Therefore, the particle size of the light diffusing material PD is preferably 5 μm or less.

[0022] In the semiconductor light-emitting device 1 of this embodiment, the light emitted from the surface of the phosphor-containing sealing member 80 is a white mixed color light (additive mixed light) obtained by mixing the blue light emitted from the light-emitting element 50 and the yellow light (fluorescence) with a wide half-width emitted from the phosphor particles PP.

[0023] 3A shows the emission angle dependence of the chromaticity of the mixed color light emitted from the surface of the phosphor-containing sealing member 80 of the semiconductor light-emitting device 1 of this embodiment. Also, FIGS. 3B and 3C show the emission angle dependence of the chromaticity of the mixed color light emitted from the surface of the phosphor-containing sealing member 80 of the semiconductor light-emitting devices of Comparative Examples 1 and 2.

[0024] 3(a) to 3(c) represent the angle θ (emission azimuth angle) between the light emitted from the surface of the phosphor-containing sealing member 80 and the perpendicular to the exposed surface of the phosphor-containing sealing member 80 (see FIG. 4). On the other hand, the vertical axis of the graph represents the difference ΔCx and ΔCy between the chromaticity Cx and Cy of the light emitted from the phosphor-containing sealing member 80 of the semiconductor light-emitting device 1 at an emission azimuth angle of 0°, which is set as a reference value (i.e., 0), and the chromaticity Cx and Cy represent the coordinate value (Cx) on the horizontal axis and the coordinate value (Cy) on the vertical axis of the chromaticity diagram (CIE 1931) defined by the CIE (Commission Internationale de l'Eclairage).

[0025] The chromaticity Cx and Cy of the light emitted in the direction perpendicular to the exposed surface of the phosphor-containing sealing member 80 of the semiconductor light-emitting device 1 (at an emission azimuth angle of 0°) are approximately Cx = 0.33 and Cy = 0.33. In other words, the light is a white color obtained by additively mixing two colors of light with different hues. Therefore, the smaller the differences ΔCx and ΔCy between the chromaticity Cx and Cy values ​​at each emission azimuth angle and the chromaticity Cx and Cy values ​​at an emission azimuth angle of 0°, the smaller the chromaticity deviation, which is preferable when the semiconductor light-emitting device 1 is viewed from the front (at an emission azimuth angle of 0°) or from an oblique direction.

[0026] Furthermore, in the chromaticity diagram, in the vicinity of Cx=0.33 and Cy=0.33, even if the values ​​of Cx and Cx deviate from 0.33, if the values ​​of Cx and Cy are equal, the light will be white, but if the values ​​of Cx and Cy are not equal, the light will be mixed with a different hue (for example, light shifted toward green or red). Therefore, it is preferable that the difference between the values ​​of ΔCx and ΔCy is small.

[0027] In the semiconductor light-emitting device 1 of this embodiment, the differences ΔCx and ΔCy between the chromaticity Cx and Cy values ​​at each emission azimuth angle and the chromaticity Cx and Cy values ​​at an emission azimuth angle of 0° can be reduced. The difference between the ΔCx and ΔCy values ​​can also be reduced.

[0028] A semiconductor light-emitting device 1 manufactured in an example described later uses, as the light diffusing material PD, yttrium phosphate (YPO ) having a particle size of 2 μm with a geometrical optical scattering size. ４ ) particles. As shown in FIG. 3( a), the measurement range of the emission azimuth angle is the range (±70°) that the measurement device can measure without being affected by the frame 40. In the semiconductor light-emitting device of the example, the emission azimuth angle at which the differences ΔCx and ΔCy in the chromaticity Cx and Cy values ​​at each emission azimuth angle within the measurement range, relative to the chromaticity Cx and Cy values ​​(reference values) at an emission azimuth angle of 0°, are maximum is +70°, as shown in FIG. 3( a), where ΔCx is 0.003 and ΔCy is 0.005. Therefore, the differences ΔCx and ΔCy in the chromaticity Cx and Cy at each emission azimuth angle relative to the chromaticity Cx and Cy at an emission azimuth angle of 0° are kept small.

[0029] Furthermore, at each emission azimuth angle of the semiconductor light-emitting device 1 of the embodiment, the maximum value of the difference between the chromaticity Cx and Cy, which represents the deviation from white, |ΔCx−ΔCy|, is 0.002 at an emission azimuth angle of +70°, and the deviation of the chromaticity from white is also kept small.

[0030] In contrast, the semiconductor light emitting device manufactured in Comparative Example 1 described later uses alumina (Al ２ O ３ ) particles. Within the measurement range of the emission azimuth angle of the semiconductor light-emitting device of Comparative Example 1, the emission azimuth angle at which the differences ΔCx and ΔCy between the chromaticity Cx and Cy values ​​(reference values) at each emission azimuth angle are maximized is the emission azimuth angle +70° for Cx, where ΔCx = 0.006, as shown in FIG. 3(b). On the other hand, for Cy, ΔCy = 0.01 at an emission azimuth angle +60°, and values ​​greater than this could not be measured. Therefore, the maximum values ​​of ΔCx and ΔCy were larger than those of the examples.

[0031] Furthermore, at each emission azimuth angle of the semiconductor light-emitting device 1 of the comparative example, the maximum value of the magnitude of the difference between the chromaticity Cx and Cy, which represents the deviation from white, |ΔCx−ΔCy|, cannot be calculated because ΔCy becomes 0.01 or more when the emission azimuth angle is +60° or more, as shown in Figure 3(b).

[0032] The light output of the semiconductor light emitting device of Comparative Example 1 was 97% of the light output of the semiconductor light emitting device of the Example.

[0033] In the semiconductor light emitting device of Comparative Example 1, the light diffusing material PD was alumina (Al ２ O ３ Instead of the titanium dioxide (TiO) particles, the particle size was 1.5 μm, which is the geometrical optical scattering size. ２ Even when alumina (Al) particles are used, ２ O ３ The directional characteristics and light output were similar to those of the case using ) particles.

[0034] Furthermore, the semiconductor light-emitting device manufactured in Comparative Example 2 described later contained titanium oxide (TiO ) with a particle size of 0.25 μm, which is the particle size that causes Mie scattering, as the light diffusing material PD. ２ ) particles. In the semiconductor light-emitting device of Comparative Example 2, the output azimuth angle at which the magnitude of the difference ΔCx, ΔCy in the chromaticity Cx and Cy values ​​at each output azimuth angle within the measurement range becomes maximum relative to the values ​​(reference values) of the chromaticity Cx and Cy at an output azimuth angle of 0° is, as shown in FIG. 3(b), when the output azimuth angle for ΔCx is -70°, and the magnitude of ΔCx at this time is approximately 0.001. On the other hand, the magnitude of ΔCy at an output azimuth angle is maximum at -60°, and the magnitude of ΔCy at this time is approximately 0.001. Therefore, the maximum values ​​of the differences ΔCx, ΔCy in the chromaticity Cx and Cy at each output azimuth angle relative to the chromaticity Cx and Cy at an output azimuth angle of 0° are both approximately 0.001, which is suppressed to a value equal to or smaller than that of the Examples.

[0035] Furthermore, at each emission azimuth angle of the semiconductor light-emitting device 1 of Comparative Example 2, the maximum value of the difference between the chromaticity Cx and Cy, which represents the deviation from white, |ΔCx−ΔCy|, is approximately 0.001 at an emission azimuth angle of −70°, and the deviation of the chromaticity from white is also kept small.

[0036] However, the light output of the semiconductor light emitting device of Comparative Example 2 was significantly attenuated to 25% of the light output of the semiconductor light emitting device of the Example.

[0037] In this way, by using yttrium phosphate particles of geometric optical scattering size as the light diffusing material PD, the semiconductor light emitting device 1 of this embodiment can reduce the differences ΔCx and ΔCy in chromaticity Cx and Cy at each output azimuth angle relative to the chromaticity Cx and Cy at an output azimuth angle of 0° without attenuating the light output, thereby reducing the chromaticity deviation of the output light due to the output azimuth angle. Furthermore, the semiconductor light emitting device 1 of this embodiment can reduce the magnitude |ΔCx−ΔCy| of the difference between chromaticity Cx and Cy, which represents the deviation from white, at each output azimuth angle, allowing it to emit white light.

[0038] In contrast, a semiconductor light-emitting device using alumina particles (or titanium oxide particles) with a particle size that causes geometrical optical scattering as the light diffusing material PD as in Comparative Example 1 shows only a slight attenuation of light output, but the differences ΔCx and ΔCy between the chromaticities Cx and Cy at each emission azimuth angle relative to the chromaticities Cx and Cy at an emission azimuth angle of 0° are large, resulting in a stronger yellowish tint when viewed obliquely. Furthermore, the magnitude of the difference between the chromaticities Cx and Cy, |ΔCx−ΔCy|, which represents the deviation from white, increases as the emission angle increases in the semiconductor light-emitting device of Comparative Example 1, and the chromaticity deviation from white light is large when viewed obliquely.

[0039] On the other hand, in the semiconductor light-emitting device using titanium oxide particles with a particle size that causes Mie scattering as the light diffusing material PD as in Comparative Example 2, the angle dependency of chromaticity can be suppressed, but the light output of the semiconductor light-emitting device is significantly attenuated.

[0040] In the semiconductor light-emitting device 1 of this embodiment, at each emission azimuth angle, the maximum value of the magnitude of the difference ΔCx and ΔCy between the chromaticity Cx and Cy of the emitted light at each emission azimuth angle relative to the chromaticity Cx and Cy of the emitted light at an emission azimuth angle of 0° is preferably within 0.006, and particularly preferably within 0.003. Furthermore, because the emitted light from the semiconductor light-emitting device 1 has a Lambertian light distribution, the maximum value of the magnitude of ΔCx and ΔCy is preferably within 0.005, and particularly preferably within 0.003, at the angle (half-value angle) at which the light intensity at each emission azimuth angle is half of the light intensity at an emission azimuth angle of 0°, i.e., in the angle range of 120° between emission azimuth angles of -60° and +60°.

[0041] In addition, in the semiconductor light emitting device 1 of this embodiment, the magnitude of the difference between the chromaticity Cx and Cy, which indicates the deviation from white, |ΔCx−ΔCy|, is preferably 0.003 or less.

[0042] Yttrium phosphate is a phosphate composed of a rare earth transition metal and phosphoric acid. Optical glass containing this phosphate exhibits anomalous partial dispersion. It also has high transmittance for visible light and excellent forward scattering characteristics. Examples of such materials include phosphates in which yttrium (Y) is substituted with one or more of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), and gadolinium (Gd). Therefore, these phosphates can also be used in place of yttrium phosphate.

[0043] The materials of each part will be described in more detail below.

[0044] <Lead electrodes 10, 20> The lead electrodes 10, 20 are made of a Cu / Ni / Au material, which is made by plating nickel (Ni) and gold (Au) in this order on a copper (Cu) base material. Cu / Ni / silver (Ag), Cu / titanium (Ti) / Au, Cu / Ti / Ag, etc. may also be used. Iron alloys (Fe—Ni—Co) may also be used as the base material.

[0045] <Frame 40> The frame 40 is preferably made of a light-reflecting material, and the resin medium may be any of PCT (polycyclohexylene dimethylene terephthalate) resin, PA6T (polyamide 6T) resin, PA9T (polyamide 9T) resin, epoxy resin, and silicone resin. The frame 40 resin is preferably a thermosetting resin from the viewpoint of adhesion to the lead electrodes 10 and 20, but may also be a thermoplastic resin. It may also contain a reinforcing filler such as glass fiber.

[0046] In order to form the light-reflective frame 40, titanium oxide (TiO ) having a particle size that causes Mie scattering is added to the resin medium as added fine particles. ２ ) particles, aluminum oxide (Al ２ O ３ ) particles, and zirconium oxide (ZrO ２ ) particles can be added.

[0047] For example, titanium oxide (TiO ２ When particles are used, those with a particle size of 200 to 300 nm are used, and the amount added is about 6 wt % to 54 wt %.

[0048] <Light-emitting element 50> The light-emitting element 50 may have any wavelength, but since the semiconductor light-emitting device 1 is configured as a device that emits white light, a light-emitting element 50 that emits blue light (peak wavelength 440 nm to 460 nm) is used here.

[0049] <Adhesive Member 60 of Light Emitting Element 50> A die attachment material is used as the adhesive member 60. The die attachment material is a light-transmitting resin (for example, silsesquioxane (SQ) resin) in which particles having heat dissipation and light reflectivity (for example, titanium oxide, particle size 1 to 500 nm) are dispersed.

[0050] <Protection Element 51> A Zener diode is used as the protection element 51. The protection element 51 is provided so as to be connected with a polarity opposite to that of the light emitting element 50. The protection element 51 may also be a varistor, a capacitor, or the like.

[0051] <Conductive Adhesive for Protective Element 51> As the conductive adhesive for the protective element 51, silver paste (for example, silver (Ag) particles dispersed in epoxy resin) is used.

[0052] <Material of Light-Reflective Sealing Member 70> For example, a transparent silsesquioxane (SQ) resin in which light-reflective particles (for example, titanium oxide, particle size 1 to 500 nm) are dispersed is used as the light-reflective sealing member 70. The light-reflective sealing member 70 should preferably be made of a resin with a higher hardness than the frame 40. This can prevent peeling of the bottom surface of the phosphor-containing sealing member 80 and prevent a decrease in light output.

[0053] <Light Diffusing Material PD of Phosphor-Containing Sealing Member 80> As described above, yttrium phosphate (YPO ４ The particle size of the yttrium phosphate particles is preferably smaller than the median particle size of the phosphor particles PP. Specifically, the particle size of the yttrium phosphate particles is preferably 1 μm or more and 5 μm or less.

[0054] The refractive index of yttrium phosphate is 1.85 to 1.9.

[0055] In addition, YPO 4 is used as yttrium phosphate particles. ４ or YPO ４ ・2H ２ Polyhydrates such as 0 can also be used.

[0056] <Phosphor Particles PP of Phosphor-Containing Sealing Member 80> The phosphor particles PP are excited by the blue light emitted by the light-emitting element 50 and emit yellow fluorescence. The particle size of the phosphor particles PP is preferably 5 μm or more and 50 μm or less. Examples of phosphors include YAG:Ce phosphors in which a cerium (Ce) activator is added to a base material of yttrium aluminum garnet (YAG), and LSN:Ce (La ３ Si ６ N １１It is also possible to use one or more phosphors selected from a green phosphor β-sialon phosphor, a red silicon nitride phosphor (CASN, SCASN) and a silicon fluoride phosphor (KSF).

[0057] <Resin of Phosphor-Containing Sealing Member 80> In the phosphor-containing sealing member 80, a resin that does not absorb the light emitted by the light-emitting element 50 or the fluorescence emitted by the phosphor particles PP is used as the resin in which the phosphor particles PP and the light diffusing material PD are dispersed. For example, a transparent resin such as a silicone resin (specifically, a dialkyl silicone resin (e.g., dimethyl silicone)), an epoxy resin, or an acrylic resin can be used.

[0058] The method for manufacturing the semiconductor light emitting device 1 of the embodiment will be described with reference to the steps in the flow chart of FIG. 5, as well as FIGS.

[0059] <Step 200> A metal plate (for example, a copper (Cu) plate) that will become the lead electrodes 10, 20 is prepared.

[0060] <Step 201> The metal plate prepared in step 200 is punched with a die to form the lead frame 100 (FIG. 6A). The lead frame 100 has a structure in which multiple sets of lead electrodes 10, 20 are connected by their edges.

[0061] In addition to the punching method, another method is to form a resist mask and then cut out the pattern by etching.

[0062] <Step 202> Nickel (Ni) and gold (Au) are layered in this order on the surface of the copper lead frame 100 by electrolytic plating.

[0063] <Step 203> Next, a white frame 40 is molded on the lead frame 100 using a thermoplastic resin or a thermosetting resin by insert molding (see FIG. 6B).

[0064] <Step 204> A die attachment material that will become the adhesive member 60 is applied to the area of ​​the lead frame 100 that will become the lead electrodes 20, and the light emitting element 50 is mounted on the die attachment material using a mounter.

[0065] Furthermore, silver paste is applied as a conductive adhesive to the area of ​​the lead frame 100 that will become the lead electrode 10, and the protective element 51 is mounted on the silver paste with a mounter.

[0066] The adhesive member 60 and the conductive adhesive are hardened by heating at approximately 180° C. for 30 minutes, and the light emitting element 50 and the protective element 51 are mounted (bonded).

[0067] The upper electrodes of the light emitting element 50 and the protective element 51 are wire-bonded to predetermined lead electrodes 10 and 20 using gold wires as bonding wires 90, 91, and 93, respectively.

[0068] <Step 205 > A white silsesquioxane (SQ) silicone resin is applied as the light-reflective sealing member 70 to the upper surface regions of the lead electrodes 10 and 20 .

[0069] After the resin that will become the light-reflective sealing member 70 flows and takes on a predetermined shape, it is heated at 180° C. for 10 minutes to form a semi-cured light-reflective sealing member 70 .

[0070] <Step 206> A translucent silicone resin in which phosphor particles PP and yttrium phosphate particles as the light diffusing material PD are dispersed is filled into the frame 40 as the phosphor-containing sealing member 80. ４ The YPO particles have a particle diameter (median particle diameter) of 2 μm and a refractive index of 1.85. ４ The particle addition amount was 15 wt %. The cerium-activated lanthanum silicon nitride phosphor (LSN:Ce) particles used as the phosphor particles PP had a particle diameter (median particle diameter) of 15 μm. The LSN:Ce addition amount was 12 wt %.

[0071] After the surface (top surface) of the resin that will become the phosphor-containing sealing member 80 has become approximately flat, the resin is hardened by heating at 150° C. for 3 hours to form the phosphor-containing sealing member 80. Note that the light-reflective sealing member 70 is also fully hardened in this process.

[0072] <Step 207> The edge of the lead frame 100 is tie-bar cut to separate the lead frame 100 into individual semiconductor light emitting devices 1. In this way, the semiconductor light emitting devices 1 of the embodiment can be manufactured.

[0073] Comparative Example 1 In the semiconductor light emitting device of Comparative Example 1, the light diffusing material PD contained in the phosphor-containing sealing member 80 is alumina (Al ２ O ３ The other configurations and manufacturing processes are the same as those of the semiconductor light emitting device 1 of the example. Only the changes will be described below.

[0074] The light diffusing material PD contained in the phosphor-containing sealing member 80 is alumina (Al ２ O ３ ) particles were used, and the amount added was set to 15 wt %.

[0075] Comparative Example 2 In the semiconductor light emitting device of Comparative Example 2, the light diffusing material PD contained in the phosphor-containing sealing member 80 was replaced with titanium oxide (TiO ２ The other configurations and manufacturing processes are the same as those of the semiconductor light emitting device 1 of the example. Only the changes will be described below.

[0076] The light diffusing material PD contained in the phosphor-containing sealing member 80 is rutile-type titanium oxide (TiO ) having a particle size (median particle size) of 0.25 μm, which is within the particle size range that causes Mie scattering, and a refractive index of 2.71. ２ ) particles were used, and the amount added was 5 wt %.

[0077] As described above, in the examples, it was confirmed that by using yttrium phosphate particles with a particle size of 1 μm to 5 μm as the light diffusing material PD of the phosphor-containing sealing member 80, the chromaticity difference between the light emitted in the vertical direction and the light emitted in the oblique direction of the semiconductor light-emitting device is extremely small.

[0078] In other words, according to the present invention, in a light-emitting device having a structure in which light emitted from the top and side surfaces of a light-emitting element is wavelength-converted using a phosphor-containing resin layer, it is possible to reduce the angular dependency of the chromaticity of the additively mixed emitted light.

[0079] Furthermore, according to the present invention, even in a semiconductor light-emitting device that emits white light by mixing light of two or more hues, it is possible to reduce the angular dependency of chromaticity without attenuation of light output.

[0080] REFERENCE SIGNS LIST 1 semiconductor light emitting device 10 lead electrode 20 lead electrode 30 gap 40 frame body 40a step 50 light emitting element 51 protective element 60 adhesive member 70 light reflective sealing member 80 phosphor-containing sealing member 90 bonding wire 91 bonding wire 93 bonding wire

Claims

a light-emitting element mounted on an upper surface of the substrate; a frame surrounding the light-emitting element; and a phosphor-containing sealing member containing phosphor particles, covering an upper surface of the light-emitting element and filling a space from a side surface of the light-emitting element to the frame, wherein a light diffusing material is dispersed in the phosphor-containing sealing member, and light emitted from the light-emitting element and fluorescence emitted from the phosphor particles are mixed and emitted from a surface of the phosphor-containing sealing member, and the differences ΔCx and ΔCy of the chromaticities Cx and Cy of the light emitted in an oblique direction from the surface of the phosphor-containing sealing member relative to the chromaticity Cx and Cy of the light emitted in a perpendicular direction from the surface of the phosphor-containing sealing member are 0.006 or less, respectively, and wherein Cx and Cy are the coordinate values ​​on the horizontal and vertical axes of a chromaticity diagram (CIE 1931), 2. A semiconductor light emitting device according to claim 1, wherein said light diffusing material is particles of a salt of a rare earth transition metal and a phosphoric acid.

3. A semiconductor light-emitting device according to claim 2, wherein the light diffusing material is yttrium phosphate particles, and the particle size of the yttrium phosphate particles is smaller than the median particle size of the phosphor particles.

4. A semiconductor light emitting device according to claim 3, wherein the particle diameter of said yttrium phosphate particles is 1 μm or more and 5 μm or less.

5. A semiconductor light emitting device according to claim 3, wherein the particle size of said phosphor particles is 5 μm or more and 50 μm or less.

6. A semiconductor light-emitting device as claimed in claim 1, characterized in that the light emitted from said light-emitting element and the fluorescence emitted from said phosphor particles have different hues, and are a mixture of light of different hues.

7. A semiconductor light-emitting device as described in claim 6, wherein the light-emitting element emits blue light, the phosphor particles emit yellow fluorescence, and the mixture of the blue light and the yellow light is white light.

8. A semiconductor light-emitting device as described in claim 1, wherein the substrate is a pair of plate-shaped, spaced-apart lead electrodes, the light-emitting element is placed on the upper surface of one of the pair of lead electrodes, a portion of the upper surface of the pair of lead electrodes between the inner surface of the frame and the light-emitting element is covered with a light-reflective sealing member, the light-reflective sealing member has light-reflective properties with respect to the light emitted from the light-emitting element and the fluorescence emitted from the phosphor particles, the thickness of the light-reflective sealing member increases with increasing distance from the light-emitting element, the upper surface of the light-reflective sealing member is inclined, and the phosphor-containing sealing member covers the upper surface of the light-reflective sealing member.

9. A semiconductor light emitting device according to claim 1, wherein the difference between the chromaticities Cx and Cy of the light emitted obliquely from the surface of the phosphor-containing sealing member is within 0.003.

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