Semiconductor light-emitting device

Abstract

To provide a light-emitting device for performing wavelength conversion of emission light by a phosphor-containing resin layer, which reduces angle dependence of chromaticity of the emission light.SOLUTION: A frame body is provided so as to surround a light-emitting element mounted on the upper surface of a substrate, and covers the upper surface of the light-emitting element, and a space from the side face 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. Light emitted from the light-emitting element and fluorescent light emitted from phosphor particles are mixed and the mixed light is emitted from the surface of the phosphor-containing sealing member. Differences ΔCx and ΔCy between chromaticity Cx and chromaticity Cy of the light emitted in an oblique direction from the surface of the phosphor-containing sealing member and chromaticity Cx and chromaticity Cy of light emitted in a normal direction are 0.006 or less, provided that Cx and Cy are coordinate values of a horizontal axis and a vertical axis of a chromaticity diagram (CIE1931).SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] In a light-emitting device in which the upper surface of a light-emitting element provided on a substrate is sealed with a resin, there is a chromaticity shift between the light emitted in the front direction and the light emitted in the oblique direction, and this chromaticity shift causes illumination unevenness, as disclosed in Patent Document 1. In the invention of Patent Document 1, by mixing a diffusing material into the resin disposed on the upper surface of the light-emitting element, the difference between the maximum value and the minimum value of the chromaticity y in the range of -60 degrees or more and 60 degrees or less of the measurement angle is suppressed to a predetermined value or less.

[0003] Further, 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 inside the frame-shaped resin portion to seal the upper surface and side surfaces of the light-emitting element with the resin.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The technique of Patent Document 1 is effective in suppressing the difference between the maximum value and the minimum value of the chromaticity y in a light-emitting device that emits monochromatic light only from the upper surface of the light-emitting element. However, in the case of a light-emitting device that emits white light by dispersing a phosphor in the resin and uses the light emitted from the upper surface 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 that emits light from the upper surface and the side surface of a light-emitting element, the optical path length of the light emitted from the upper surface of the light-emitting element and traveling directly upward through the phosphor-containing resin layer is different from the optical path length of the light emitted from the side surface of the light-emitting element and traveling toward the upper surface of the phosphor-containing resin layer through the resin layer. The longer the optical path length through the phosphor-containing resin layer, the higher the ratio of fluorescence to excitation light. Therefore, the light emitted from the side surface of the light-emitting element has an increased ratio of fluorescence to excitation light, causing color unevenness.

[0007] Also, as shown in FIGS. 8(a) and 8(b), while the emission directivity of the light emitted from the light-emitting element is Lambertian emission, fluorescence is emitted omnidirectionally from each phosphor particle. For this reason, even if a light diffusing material is added to the phosphor-containing resin, it is difficult to make the emission directivity of the additive mixture light emitted from the upper surface of the phosphor-containing resin layer match that of the fluorescence and the excitation light, which causes color unevenness.

[0008] An object of the present invention is to reduce the angular dependence of the chromaticity of the additive mixture emission light in a light-emitting device having a structure in which the light emitted from the upper surface and the side surface of a light-emitting element is wavelength-converted by a phosphor-containing resin layer.

Means for Solving the Problems

[0009] To achieve the above object, a semiconductor light-emitting device of the present invention includes a substrate, a light-emitting element mounted on the upper surface of the substrate, a frame provided so as to surround 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 surface 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, and the chromaticity Cx, Cy of the light emitted obliquely from the surface of the phosphor-containing sealing member satisfies that the differences ΔCx, ΔCy from the chromaticity Cx, Cy of the light emitted in the perpendicular direction from the surface of the phosphor-containing sealing member are each 0.006 or less. Here, Cx and Cy are the coordinate values on the horizontal axis and the vertical axis of the chromaticity diagram (CIE1931), respectively.

Advantages of the Invention

[0010] According to the present invention, in a light-emitting device having a structure in which light emitted from the upper surface and the side surface of a light-emitting element is wavelength-converted by a phosphor-containing resin layer, it is possible to reduce the angular dependence of the chromaticity of the emitted light.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0012] One 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 the present embodiment will be described with reference to FIGS. 1 and 2. FIGS. 1(a) to (c) are a top view, a long-side side view, and a short-side side view of the semiconductor light-emitting device 1, respectively, (d) and (e) are cross-sectional views taken along line A-A and line B-B, and (f) is a top view of the state excluding the encapsulating resin. FIGS. 2(a) to (d) are a top view, a long-side side view, a short-side side view, and a cross-sectional view taken along line A-A of the lead electrodes 10 and 20 and the frame body 40.

[0014] The semiconductor light-emitting device 1 includes a pair of flat lead electrodes 10 and 20, a frame body 40, a light-emitting element 50, a light-reflective encapsulating member 70, and a phosphor-containing encapsulating member 80. The frame body 40 is in a bank shape that surrounds the periphery while embedding the gap 30 between the lead electrodes 10 and 20. The light-emitting element 50 is adhered via an adhesive member 60 to the upper surface of one of the lead electrodes 20 on the concave side defined by the inner side surface of the frame body 40 and the upper surfaces of the lead electrodes 10 and 20. The light-reflective encapsulating member 70 embeds from around the light-emitting element 50 to the inner side surface of the frame body 40. The phosphor-containing encapsulating member 80 covers the light-emitting element 50 and the reflective encapsulating member and embeds the above concave portion. Further, bonding wires 90 and 91 for connecting a pair of upper surface electrodes (not shown) of the light-emitting element 50 to each of the lead electrodes 10 and 20 are provided. Further, the semiconductor light-emitting element 1 includes a protective element 51 adhered via a conductive adhesive on the lead electrode 10 on the side where the light-emitting element 50 is not adhered, and a bonding wire 93 for connecting the upper electrode of the protective element 51 and the lead electrode.

[0015] The frame body 40 is rectangular, mounted on the lead electrodes 10 and 20, and covers the long-side side surfaces of the lead electrodes 10 and 20 in the long-side direction. The frame body 40 prevents peeling between the lead electrodes 10 and 20 and the frame body 40 by filling a step 40a (see FIG. 1(e)) provided on the long-side side surfaces of the lead electrodes 10 and 20. Further, the resin constituting the frame body 40 fills the gap 30 provided between the lead electrodes 10 and 20.

[0016] A part of the upper surfaces of the pair of lead electrodes 10 and 20 between the inner side surface of the frame body 40 and the light-emitting element 50 is covered by the light-reflective encapsulating member 70.

[0017] Also, the space from the side surface of the light-emitting element 50 to the inner surface of the frame body 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 its surface is substantially flat. The height of the surface of the phosphor-containing sealing member 80 is the same as the height of the frame body 40 (the upper end of the frame body 40 in FIG. 1(d)).

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

[0019] The light-reflective sealing member 70 is not in contact with the side surface of the light-emitting element 50. The thickness of the light-reflective sealing member 70 is formed to increase as it moves away 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 the light emitted from the side surface 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 emitted from the light-emitting element 50 (for example, blue light) and the fluorescence emitted from the phosphor particles PP (for example, yellow light) are additively mixed and diffused, and then emitted from the surface of the phosphor-containing sealing member 80. That is, the semiconductor light-emitting device 1 is a light-emitting device that emits mixed light (for example, white light) containing two or more colors of light with different hues.

[0021] The light diffusing material PD is yttrium phosphate particles with a particle size mainly for geometric optical scattering. The specific particle size of the light diffusing material PD is preferably 1 μm or more in the visible light band where geometric optical scattering characteristics are dominant. Also, the particle size of the light diffusing material PD is smaller than that of the phosphor particles PP, and scatters the light emitted from the phosphor particles PP to reduce color unevenness. Further, the particle size (median size) of the phosphor particles PP excited by blue light (about 445 nm) as excitation light is preferably about 5 μm to 50 μm for good absorption efficiency of 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 the present embodiment, the light emitted from the surface of the phosphor-containing sealing member 80 is a white mixed light (additive mixed light) in which the blue light emitted from the light emitting element 50 and the broad half-value width yellow light (fluorescence) emitted from the phosphor particles PP are mixed.

[0023] The emission angle dependence of the chromaticity of the mixed light emitted from the surface of the phosphor-containing sealing member 80 of the semiconductor light emitting device 1 of the present embodiment is shown in Fig. 3(a). Also, the emission angle dependence of the chromaticity of the mixed light emitted from the surface of the phosphor-containing sealing member 80 of the semiconductor light emitting devices of Comparative Examples 1 and 2 is shown in Figs. 3(b) and (c).

[0024] The horizontal axis of the graphs in Figs. 3(a) to (c) is the angle θ (emission azimuth angle) formed by the light emitted from the surface of the phosphor-containing sealing member 80 with 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 shows the differences ΔCx and ΔCy from the reference values of the chromaticity Cx and Cy of the light emitted at the emission azimuth angle of 0° of the phosphor-containing sealing member 80 of the semiconductor light emitting device 1, with the chromaticity Cx and Cy of the light emitted at each emission azimuth angle as the reference values (i.e., 0). The chromaticity Cx and Cy are the coordinate values (Cx) on the horizontal axis and the coordinate values (Cy) on the vertical axis of the chromaticity diagram (CIE1931) defined by the CIE (International Commission on Illumination).

[0025] The chromaticity values Cx and Cy of the emitted light in the direction perpendicular to the exposed surface of the phosphor-containing sealing member 80 of the semiconductor light-emitting device 1 (emission azimuth angle 0°) are generally Cx = 0.33 and Cy = 0.33. That is, it is white formed by additive mixing of two lights with different hues. Therefore, the smaller the differences ΔCx and ΔCy between the values of chromaticity Cx and Cy at each emission azimuth angle and the values of chromaticity Cx and Cy at the emission azimuth angle 0°, the more preferable it is because the chromaticity shift is small whether the semiconductor light-emitting device 1 is viewed from the front (emission azimuth angle 0°) or from an oblique direction.

[0026] Furthermore, in the chromaticity diagram, in the vicinity of Cx = 0.33 and Cy = 0.33, when the values of Cx deviate from 0.33 but the values of Cx and Cy are equal, it is white, and when the values of Cx and Cy are not equal, it becomes a mixed-color light with a different tint (for example, light shifted in the green direction or the red direction). Therefore, it is also preferable that the difference between the values of ΔCx and ΔCy is small.

[0027] In the semiconductor light-emitting device 1 of the present embodiment, the differences ΔCx and ΔCy between the values of chromaticity Cx and Cy at each emission azimuth angle and the values of chromaticity Cx and Cy at the emission azimuth angle 0° can be made small respectively. Also, the difference between the values of ΔCx and ΔCy can be made small.

[0028] Specifically described below. The semiconductor light-emitting device 1 manufactured in the example described later is an example in which yttrium phosphate (YPO4) particles with a particle size of 2 μm in terms of geometric optical scattering size are used as the light diffusing material PD. As shown in Fig. 3(a), the measurement range of the emission azimuth angle is the range (±70°) where the measuring device can be measured without being affected by the frame body 40. In the semiconductor light-emitting device of the example, with respect to the values of chromaticity Cx and Cy (reference values) at the emission azimuth angle 0°, the emission azimuth angle at which the differences ΔCx and ΔCy between the values of chromaticity Cx and Cy at each emission azimuth angle within the measurement range become the maximum values is +70° as shown in Fig. 3(a), ΔCx is 0.003, and ΔCy is 0.005. Therefore, the differences ΔCx and ΔCy between the chromaticity Cx and Cy at each emission azimuth angle and the chromaticity Cx and Cy at the emission azimuth angle 0° are suppressed to be small.

[0029] In addition, at each emission azimuth angle of the semiconductor light-emitting device 1 of the embodiment, the maximum value of the magnitude |ΔCx−ΔCy| of the difference between chromaticity Cx and Cy representing the deviation from white is 0.002 at the emission azimuth angle of +70°, and the deviation of chromaticity from white is also suppressed to be small.

[0030] On the other hand, the semiconductor light-emitting device manufactured in Comparative Example 1 described later is an example in which alumina (Al2O3) particles having a particle size of 1.5 μm in geometric optical scattering size are used as the light diffusing material PD. Within the measurement range of the emission light azimuth angle of the semiconductor light-emitting device of Comparative Example 1, with respect to the values (reference values) of chromaticity Cx and Cy at the emission azimuth angle of 0°, the differences ΔCx and ΔCy in the values of chromaticity Cx and Cy at each emission azimuth angle are the maximum values, respectively. As shown in FIG. 3(b), for Cx, the emission azimuth angle is +70°, and ΔCx = 0.006. On the other hand, for Cy, ΔCy reached 0.01 at the emission azimuth angle of +60°, and values above that could not be measured. Therefore, the maximum values of ΔCx and ΔCy were larger than those of the example.

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

[0032] In addition, 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] Note that, in the semiconductor light-emitting device of Comparative Example 1, when the light diffusing material PD was replaced with titanium oxide (TiO2) particles having a particle size of 1.5 μm in geometric optical scattering size instead of alumina (Al2O3) particles, the directivity characteristics and light output were the same as those when alumina (Al2O3) particles were used.

[0034] Furthermore, the semiconductor light-emitting device manufactured in Comparative Example 2 described below is an example in which titanium oxide (TiO2) particles with a particle size of 0.25 μm, which is a particle size that causes Mie scattering, are used as the light diffusing material PD. In the semiconductor light-emitting device of Comparative Example 2, with respect to the values (reference values) of chromaticity Cx and Cy at an emission azimuth angle of 0°, the emission azimuth angle at which the magnitudes of the differences ΔCx and ΔCy between the values of chromaticity Cx and Cy at each emission azimuth angle within the measurement range reach the maximum value is, as shown in FIG. 3(b), -70° for ΔCx, and the magnitude of ΔCx at that time is about 0.001. On the other hand, for ΔCy, the magnitude is maximum at an emission azimuth angle of -60°, and at that time, the magnitude of ΔCy is about 0.001. Therefore, the maximum values of the differences ΔCx and ΔCy between the chromaticities Cx and Cy at each emission azimuth angle with respect to the chromaticities Cx and Cy at an emission azimuth angle of 0° are both suppressed to be as small as about 0.001, which is equal to or less than that of the example.

[0035] Also, at each emission azimuth angle of the semiconductor light-emitting device 1 of Comparative Example 2, the maximum value of the magnitude of the difference |ΔCx - ΔCy| between chromaticity Cx and Cy representing the deviation from white is about 0.001 at an emission azimuth angle of -70°, and the chromaticity deviation from white is also suppressed to be 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] Thus, by using yttrium phosphate particles with a geometric optical scattering size as the light diffusing material PD, the semiconductor light-emitting device 1 of the present embodiment can suppress the differences ΔCx and ΔCy between the chromaticities Cx and Cy at each emission azimuth angle with respect to the chromaticities Cx and Cy at an emission azimuth angle of 0° without attenuating the light output, and can suppress the chromaticity deviation of the emitted light due to the emission azimuth angle. Also, with respect to the magnitude of the difference |ΔCx - ΔCy| between chromaticity Cx and Cy representing the deviation from white, the semiconductor light-emitting device 1 of the present embodiment can be suppressed to be small at each emission azimuth angle, and can emit white light.

[0038] On the other hand, in a semiconductor light-emitting device using alumina particles (or titanium oxide particles) having a particle size that causes geometric optical scattering as the light diffusing material PD as in Comparative Example 1, although the attenuation of the light output is slight, the differences ΔCx and ΔCy in chromaticity Cx and Cy at each emission azimuth angle with respect to the chromaticity Cx and Cy at the emission azimuth angle of 0° are large, and the yellowish color becomes stronger in the oblique view. Further, the magnitude |ΔCx−ΔCy| of the difference in chromaticity Cx and Cy representing the deviation from white increases as the emission angle increases in the semiconductor light-emitting device of Comparative Example 1, and there is a large chromaticity deviation from white light when viewed obliquely.

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

[0040] In the semiconductor light-emitting device 1 of the present embodiment, at each emission azimuth angle, it is preferable that the maximum value of the magnitudes of the differences ΔCx and ΔCy in chromaticity Cx and Cy of the emitted light at each emission azimuth angle with respect to the chromaticity Cx and Cy of the emitted light at the emission azimuth angle of 0° is within 0.006, and particularly preferably within 0.003. Further, since the emitted light of the semiconductor light-emitting device 1 has a Lambertian distribution, the angular range of 120° between the emission azimuth angles of -60° and +60°, which is the angle (half-value angle) at which the light intensity due to the emission azimuth angle becomes half of the light intensity at the emission azimuth angle of 0°, it is preferable that the maximum value of the magnitudes of ΔCx and ΔCy is within 0.005, and particularly preferably within 0.003.

[0041] Further, in the semiconductor light-emitting device 1 of the present embodiment, it is preferable that the magnitude |ΔCx−ΔCy| of the difference in chromaticity Cx and Cy representing the deviation from white is 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 as a material exhibits abnormal partial dispersion. Also, it has a high transmittance in the visible light band and excellent forward scattering characteristics. 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, it is also possible to use these phosphates instead of yttrium phosphate.

[0043] Hereinafter, the materials of each part will be described more specifically.

[0044] <Lead electrodes 10, 20> For the lead electrodes 10 and 20, a Cu / Ni / Au material obtained by plating nickel (Ni) and gold (Au) in this order on a main material of copper (Cu) was used. Note that Cu / Ni / silver (Ag), Cu / titanium (Ti) / Au, Cu / Ti / Ag, etc. can also be used. As the main material, an iron alloy (Fe-Ni-Co) may be used.

[0045] <Frame 40> The frame 40 is preferably made of a material that reflects light. As the resin medium, it can be formed of any one of PCT (polysicyclohexylene 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 a thermoplastic resin may also be used. Also, reinforcing fillers such as glass fibers may be included.

[0046] Also, in order to form the light-reflective frame 40, one or more of titanium oxide (TiO2) particles, aluminum oxide (Al2O3) particles, and zirconium oxide (ZrO2) particles having a particle size that causes Mie scattering can be added to the resin medium as added fine particles.

[0047] For example, when using titanium dioxide (TiO2) particles, those with a particle size of 200 to 300 nm are used, and the addition amount is about 6 wt% to 54 wt%.

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

[0049] <Adhesive member 60 of the light-emitting element 50> As the adhesive member 60, a die attach material is used. The die attach material is a material in which particles having heat dissipation properties and light reflectivity (for example, titanium dioxide, particle size: 1 to 500 nm) are dispersed in a translucent resin (for example, silsesquioxane (SQ) resin).

[0050] <Protective element 51> The protective element 51 uses a Zener diode. Further, the protective element 51 is provided so as to be connected in reverse polarity to the polarity of the light-emitting element 50. As the protective element 51, a varistor, a capacitor, etc. can also be used.

[0051] <Conductive adhesive of the protective element 51> As the conductive adhesive of the protective element 51, a silver paste (for example, a material in which silver (Ag) particles are dispersed in an epoxy resin) is used.

[0052] <Material of the light-reflective sealing member 70> As the light-reflective sealing member 70, for example, a material in which light-reflective particles (for example, titanium dioxide, particle size: 1 to 500 nm) are dispersed in a translucent silsesquioxane (SQ) resin is used. The light-reflective sealing member 70 is preferably a resin having a higher hardness than the frame body 40. Thereby, peeling of the bottom surface of the phosphor-containing sealing member 80 can be suppressed and a decrease in light output can be prevented.

[0053] <Light diffusing material PD of the phosphor-containing sealing member 80> As described above, yttrium phosphate (YPO4) particles are used as the light diffusing material PD. It is desirable that the particle size of the yttrium phosphate particles is smaller than the median particle size of the phosphor particles PP. Specifically, it is desirable that the particle size of the yttrium phosphate particles is 1 μm or more and 5 μm or less.

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

[0055] Also, hydrates such as YPO4 or YPO4·2H2O can be used as the yttrium phosphate particles.

[0056] <Phosphor particles PP of the phosphor-containing sealing member 80> As the phosphor particles PP, those that are excited by the blue light emitted by the light emitting element 50 and emit yellow fluorescence are used. It is desirable that the particle size of the phosphor particles PP is 5 μm or more and 50 μm or less. As the phosphor, for example, a YAG:Ce phosphor in which a cerium (Ce) activator is added to a base material of yttrium aluminum garnet (YAG), an LSN:Ce (La3Si6N 11 :Ce) phosphor can be used. Note that one or more phosphors can be selected and used from among β-sialon phosphors as green phosphors, silicon nitride-based phosphors (CASN, SCASN) and silicon fluoride-based phosphors (KFS) in the red color system.

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

Example

[0058] The manufacturing method of the semiconductor light-emitting device 1 of the embodiment will be described with reference to the steps of the flow in FIG. 5 and FIGS. 6 and 7.

[0059] <Step 200> Prepare metal plates (for example, copper (Cu) plates) to be the lead electrodes 10 and 20.

[0060] <Step 201> Punch out the metal plate prepared in Step 200 using a mold to form a lead frame 100 (FIG. 6(a)). The lead frame 100 has a structure in which a plurality of sets of lead electrodes 10 and 20 are connected by an edge portion.

[0061] In addition to the punching method, as another method, a resist mask can be formed and die-cut by etching.

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

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

[0064] <Step 204> Apply a die-attach material to be the adhesive member 60 to the region of the lead electrode 20 of the lead frame 100, and mount the light-emitting element 50 on the die-attach material with a mounter.

[0065] Also, apply silver paste as a conductive adhesive to the region of the lead electrode 10 of the lead frame 100, and mount the protection element 51 on the silver paste with a mounter.

[0066] Heat at about 180°C for 30 minutes to cure the adhesive member 60 and the conductive adhesive, and mount (adhere) the light-emitting element 50 and the protection element 51.

[0067] Wire-bond the gold wires as bonding wires 90, 91, 93 to the respective predetermined lead electrodes 10, 20 on the upper surface electrodes of the light-emitting element 50 and the protective element 51.

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

[0069] After the resin that becomes the light-reflective sealing member 70 has flowed and taken a predetermined shape, heat it at 180 °C for 10 minutes to form a semi-cured light-reflective sealing member 70.

[0070] <Step 206> Fill the inside of the frame 40 with a translucent silicone resin in which phosphor particles PP and yttrium phosphate particles as the light diffusing material PD are dispersed as the phosphor-containing sealing member 80. The yttrium phosphate (YPO4) particles as the light diffusing material PD have a particle size (median particle size) of 2 μm and a refractive index of 1.85. Also, the addition amount of the YPO4 particles was set to 15 wt%. Further, the cerium-activated lanthanum·silicon·nitride phosphor (LSN:Ce) particles as the phosphor particles PP have a particle size (median particle size) of 15 μm. Also, the addition amount of the LSN:Ce was set to 12 wt%.

[0071] After the surface (upper surface) of the resin that becomes the phosphor-containing sealing member 80 has become substantially flat, heat it at 150 °C for 3 hours to cure the resin and form the phosphor-containing sealing member 80. Note that in this step, the light-reflective sealing member 70 is also fully cured.

[0072] <Step 207> Cut the edges of the lead frame 100 by a dicing saw and singulate the semiconductor light-emitting device 1 into individual pieces. Thereby, the semiconductor light-emitting device 1 of the example 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 was alumina (Al2O3) particles. The other configurations and manufacturing processes are the same as those of the semiconductor light-emitting device 1 of the Example. Hereinafter, only the differences will be described.

[0074] As the light diffusing material PD contained in the phosphor-containing sealing member 80, alumina (Al2O3) particles having a particle size (median particle size) of 2 μm and a refractive index of 1.77 were used. Also, the addition amount was 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 titanium oxide (TiO2) particles. The other configurations and manufacturing processes are the same as those of the semiconductor light-emitting device 1 of the Example. Hereinafter, only the differences will be described.

[0076] As the light diffusing material PD contained in the phosphor-containing sealing member 80, rutile-type titanium oxide (TiO2) particles having a particle size (median particle size) of 0.25 μm, which causes Mie scattering, and a refractive index of 2.71 were used. Also, the addition amount was 5 wt%.

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

[0078] That is, according to the present invention, in a light-emitting device having a structure in which the light emitted from the upper surface and the side surface of the light-emitting element is wavelength-converted by a phosphor-containing resin layer, it is possible to reduce the angular dependence of the chromaticity of the additive-color mixed emitted light.

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

Explanation of Reference Numerals

[0080] 1 Semiconductor light-emitting device 10 Lead electrode 20 Lead electrode 30 Gap 40 Frame 40a Step 50 Light-emitting element 51 Protection element 60 Adhesive member 70 Light-reflective sealing member 80 Phosphor-containing sealing member 90 Bonding wire 91 Bonding wire 93 Bonding wire

Claims

1. A substrate, a light-emitting element placed on the upper surface of the substrate, a frame provided so as to surround the light-emitting element, a phosphor-containing sealing member that contains phosphor particles, covers the upper surface of the light-emitting element, and fills the space from the side surface of the light-emitting element to the frame, and comprising, in the phosphor-containing sealing member, a light diffusing material is dispersed, and the light emitted from the light-emitting element and the fluorescence emitted from the phosphor particles are mixed and emitted from the surface of the phosphor-containing sealing member, the chromaticity Cx, Cy of the light emitted obliquely from the surface of the phosphor-containing sealing member satisfies that the differences ΔCx, ΔCy with respect to the chromaticity Cx, Cy of the light emitted in the perpendicular direction from the surface of the phosphor-containing sealing member are each 0.006 or less, provided that the Cx and the Cy are the coordinate values of the horizontal axis and the vertical axis of the chromaticity diagram (CIE1931), respectively. A semiconductor light-emitting device characterized by this.

2. The semiconductor light-emitting device according to claim 1, wherein the light diffusing material is particles that are a salt of a rare earth transition metal and phosphoric acid. A semiconductor light-emitting device characterized by this.

3. The 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. A semiconductor light-emitting device characterized by this.

4. The semiconductor light-emitting device according to claim 3, wherein the particle size of the yttrium phosphate particles is 1 μm or more and 5 μm or less. A semiconductor light-emitting device characterized by this.

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

6. The semiconductor light-emitting device according to claim 1, wherein the hue of the light emitted from the light-emitting element is different from the hue of the fluorescence emitted from the phosphor particles, and it is a mixed color light of the lights having different hues. A semiconductor light-emitting device characterized by this.

7. The semiconductor light-emitting device according to claim 6, wherein the light-emitting element emits blue light, the phosphor particles emit yellow fluorescence, and the mixed color light of the blue light and the yellow light is white light. A semiconductor light-emitting device characterized by this.

8. The semiconductor light-emitting device according to claim 1, the substrate is a pair of plate-shaped and spaced-apart lead electrodes, the light-emitting element is placed on the upper surface of one of the pair of lead electrodes, a part 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 encapsulating member has light reflectivity 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 encapsulating member increases as it is farther from the light-emitting element, and the upper surface of the light-reflective encapsulating member is inclined. The phosphor-containing encapsulating member covers the upper surface of the light-reflective encapsulating member. A semiconductor light-emitting device characterized by the above.

9. The semiconductor light-emitting device according to claim 1, wherein the magnitude of the difference between the chromaticity Cx and Cy of the light emitted obliquely from the surface of the phosphor-containing encapsulating member is within 0.

003. A semiconductor light-emitting device characterized by this.

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