Semiconductor light emitting device, light emitting module and lamp assembly

Abstract

A side-emitting semiconductor light-emitting device having high brightness and excellent light distribution characteristics in the lateral direction, and a light-emitting module and lamp assembly having uniform brightness distribution are provided. [Solution] The device includes a light-emitting element having a light-emitting semiconductor layer provided on one surface of a flat substrate and a pair of element driving electrodes provided on the surface of the light-emitting semiconductor layer, and a light conversion member bonded to the other surface of the flat substrate with a light-transmitting adhesive member. The light-emitting element is provided with a first light-shielding film that covers the light-emitting element except for the other surface of the flat substrate and an area where the pair of element driving electrodes are formed, and the light conversion member is provided with a second light-shielding film that covers the entire surface opposite to the adhesive surface of the light conversion member bonded with the adhesive member, and the adhesive surface of the light conversion member is larger than the other surface of the flat substrate.

Description

[Technical Field]

[0001] The present invention relates to a semiconductor light emitting device, a light emitting module and a lamp assembly, and more particularly to a side-emitting type semiconductor light emitting device, a light emitting module and a lamp assembly. [Background technology]

[0002] In recent years, development of side-emitting light-emitting devices that emit light in the lateral direction of the light-emitting element has been progressing. For example, there is a demand for light-emitting devices that can achieve uniform surface emission by arranging multiple light-emitting elements, such as daylight running lamps (DRLs) or position lamps (POSs), and that can be driven with low power consumption using fewer light-emitting elements.

[0003] For example, Patent Document 1 discloses a side-emitting chip-type semiconductor light-emitting element in which the periphery of a light-emitting element chip is covered with a translucent material, and a light-reflecting member is provided to cover at least a portion of the translucent material and to emit light from the exposed, uncovered portion of the translucent material.

[0004] Furthermore, Patent Document 2 discloses a light emitting device having a reflecting structure that at least partially surrounds the sides of a light output section made of a semiconductor diode and a phosphor.

[0005] Furthermore, Patent Document 3 discloses an optoelectronic component having a semiconductor layer sequence that emits electromagnetic radiation of a first spectrum, a wavelength conversion layer that is arranged behind the semiconductor layer sequence and converts at least part of the electromagnetic radiation of the first spectrum into electromagnetic radiation of a second spectrum, and a filter layer that reflects at least part of radiation that is incident on the optoelectronic component from the outside. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-315825 [Patent Document 2] Special Publication No. 2011-515846 [Patent Document 3] Special Publication No. 2010-505247 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in conventional semiconductor light-emitting devices, the light distribution of the light-emitting element is a Lambertian light distribution, and the brightness (light output) on the optical axis is high. Therefore, when multiple light-emitting elements are arranged below a light-transmitting member, there is a problem that each arrangement part of the light-emitting elements emits spot light, creating a brightness distribution.

[0008] The present invention has been made in consideration of the above points, and aims to provide a side-emitting semiconductor light-emitting device that is high in brightness and has excellent light distribution characteristics in the lateral direction, as well as a light-emitting module and lamp assembly that have a uniform brightness distribution. [Means for solving the problem]

[0009] A semiconductor light emitting device according to one embodiment of the present invention comprises: a light emitting element including a light emitting semiconductor layer provided on one surface of a flat substrate and a pair of element driving electrodes provided on the surface of the light emitting semiconductor layer; a light conversion member bonded to the other surface of the flat substrate with a light-transmitting adhesive member, the light-emitting element is provided with a first light-shielding film that covers the light-emitting element except for the other surface of the flat substrate and an area where the pair of element driving electrodes are formed; the light converting member is provided with a second light-shielding film that covers the entire surface of the light converting member that faces the adhesive surface bonded by the adhesive member; The adhesive surface of the light converting member has a size equal to or larger than the other surface of the flat substrate.

[0010] Another embodiment of the light emitting module of the present invention includes: At least one of the semiconductor light emitting devices; a mounting substrate having a diffusely reflective surface; The at least one semiconductor light emitting device is mounted on the surface of the mounting substrate.

[0011] In yet another embodiment of the present invention, the lamp assembly comprises: a light-emitting module in which a plurality of the semiconductor light-emitting devices are arranged at regular intervals in one direction on a mounting substrate having a diffusely reflective surface; a light guide plate arranged parallel to the arrangement direction of the plurality of semiconductor light emitting devices; and a reflector provided on the opposite side of the semiconductor light emitting devices from the light guide plate. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view schematically showing a semiconductor light emitting device according to a first embodiment of the present invention. [Figure 2A] FIG. 2 is a cross-sectional view schematically showing a cross section of the light emitting device taken along line AA shown in FIG. [Figure 2B] FIG. 2 is a cross-sectional view showing a detailed configuration of a light-emitting element of the light-emitting device. [Figure 3] FIG. 4 is a partially enlarged cross-sectional view showing an enlarged cross section of an outer edge portion including a side surface of a phosphor plate of a light conversion unit. [Figure 4] FIG. 10 is a diagram showing optical characteristics of a light-shielding film. [Figure 5] 3A to 3C are diagrams illustrating steps in a method for manufacturing a light emitting element component. [Figure 6] 5A to 5C are diagrams illustrating steps in a method for manufacturing an optical conversion unit. [Figure 7] 10A to 10C are diagrams illustrating a bonding process for a light emitting element section and a light conversion section. [Figure 8] FIG. 1 is a cross-sectional view schematically showing a light emitting device according to a first modified example of the first embodiment. [Figure 9A] FIG. 10 is a perspective view schematically showing a light-emitting module of Example 1 (EX1) of the second embodiment. [Figure 9B] FIG. 10 is a perspective view schematically showing a light-emitting module of Example 2 (EX2) of the second embodiment. [Figure 10A] FIG. 10 is a perspective view schematically showing a light-emitting module of Example 3 (EX3) of the second embodiment. [Figure 10B] FIG. 10 is a perspective view schematically showing a light-emitting module of Example 4 (EX4) of the second embodiment. [Figure 11] FIG. 10 is a perspective view schematically showing a light-emitting module of Example 5 (EX5) of the second embodiment. [Figure 12A] 4 is a diagram showing the measurement results of the light distribution characteristics of the light emitting module of Example 1. FIG. [Figure 12B] FIG. 10 is a diagram showing the measurement results of the light distribution characteristics of the light-emitting module of Example 2. [Figure 13A] FIG. 10 is a diagram showing the measurement results of the light distribution characteristics of the light emitting module of Example 3. [Figure 13B] FIG. 10 is a diagram showing the measurement results of the light distribution characteristics of the light-emitting module of Example 4. [Figure 14A] FIG. 10 is a plan view of a lamp assembly according to a third embodiment. [Figure 14B] FIG. 10 is a cross-sectional view of a lamp assembly according to a third embodiment. [Figure 15A] 10 is a graph showing the results of measuring the luminance of the light emitting surface of the light guide plate of the lamp assembly (EX-A) of the third embodiment along the arrangement direction (x direction) of the light emitting devices. [Figure 15B] 10 is a diagram showing the in-plane luminance distribution of the light-emitting surface of the lamp assembly (EX-A) of the third embodiment in comparison with the in-plane luminance distribution of the lamp assembly of the comparative example (CX-A). FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] In the following, preferred embodiments of the present invention will be described, but these may be modified and combined as appropriate. In the following description and accompanying drawings, substantially the same or equivalent parts are designated by the same reference numerals.

[0014] [First embodiment] Fig. 1 is a perspective view schematically showing a light emitting device 10, which is a semiconductor light emitting device according to a first embodiment of the present invention. Fig. 2A is a cross-sectional view schematically showing a cross section of the light emitting device 10 taken along line AA shown in Fig. 1. Fig. 2B is a cross-sectional view showing a detailed configuration of a light emitting element 21 of the light emitting device 10.

[0015] The light emitting device 10 has a light emitting element section 20 and a light conversion section 30 bonded to the light emitting element section 20 by an adhesive layer 12 (adhesive member). The adhesive layer 12 is made of a light-transmitting adhesive member, and for example, a silicone resin can be used.

[0016] The light-emitting element section 20 has a light-emitting element 21. In this embodiment, a case will be described in which the light-emitting element 21 is an LED. The light-emitting element 21 has a rectangular parallelepiped shape. The light-emitting element 21 has a light extraction surface 21E, which is one of its main surfaces, and an element electrode surface 21F (the other main surface) facing the light extraction surface 21E. The light conversion section 30 is adhered onto the light extraction surface 21E by an adhesive layer 12.

[0017] The light-emitting element 21 has a pair of element driving electrodes, a first element electrode 23A (e.g., a p-electrode) and a second element electrode 23B (e.g., an n-electrode), provided on the element electrode surface 21F and to which a voltage is applied to drive the light-emitting element 21 to emit light.

[0018] The light-emitting element 21 is covered with a light-shielding film 25 (first light-shielding film) except for the light extraction surface 21E and the area where the element electrode 23A (first element electrode) and the element electrode 23B (second element electrode) are formed. In other words, the light-shielding film 25 covers the side surfaces of the light-emitting element 21 and the area where the semiconductor layer of the element electrode surface 21F is exposed. The light-shielding film 25 is made of a dielectric multilayer film.

[0019] As shown in Figure 2B, the light-emitting element 21 comprises a flat substrate 21A such as a growth substrate or a support substrate, and a light-emitting semiconductor layer 21B formed on the substrate 21A and having an active layer 21K, and an optical conversion section 30 is bonded to the bottom surface (i.e., the light extraction surface 21E) of the substrate 21A by an adhesive layer 12.

[0020] In the light emitting element 21, the light emitting element section 20 and the light conversion section 30 are bonded together so as to be junction down.

[0021] The light emitting element 21 is, for example, a blue-emitting GaN-based semiconductor light emitting element, and a sapphire substrate is used as the substrate. However, the light emitting element 21 is not limited to this, and light emitting elements with various emission wavelengths and crystal compositions can be used.

[0022] The light conversion unit 30 has a wavelength conversion member in which wavelength conversion particles are dispersed in an inorganic medium such as a light-diffusing ceramic, such as alumina, or glass. Specifically, the light conversion unit 30 has a flat phosphor plate 31 and a light-shielding film 35. The phosphor plate 31 has a light incident surface 31F and a light-shielding surface 31E (upper surface) that faces the light incident surface 31F. The light conversion unit 30 also has a light-shielding film 35 (second light-shielding film) that covers the light-shielding surface 31E of the phosphor plate 31 over the entire surface. The light-shielding film 35 is made of a dielectric multilayer film.

[0023] The light-shielding film 25 (first light-shielding film) and the light-shielding film 35 (second light-shielding film) are dielectric multilayer films that reflect light in the visible light range, and the light-emitting device 10 emits light in the visible light range from the side surface of the phosphor plate 31 on which the light-shielding film 35 is not provided. In this embodiment, white light is emitted from the side surface of the phosphor plate 31.

[0024] More specifically, the phosphor plate 31 uses the contained phosphor to wavelength-convert part or all of the light incident from the light-emitting element 21 and emits the converted light from the light-emitting surface, which is the side surface 31S of the phosphor plate 31. In addition, light incident from the light-emitting element 21 that has not been wavelength-converted also emits from the side surface 31S (light-emitting surface). Therefore, the phosphor plate 31 emits light emitted by the light-emitting element 21 and light whose wavelength has been converted by the phosphor from the side surface 31S, which is the light-emitting surface. In this embodiment, the phosphor plate 31 emits white light that is a mixture of blue light emitted from the light-emitting element 21 and yellow light whose wavelength has been converted by the phosphor.

[0025] The phosphor plate 31 is an alumina / YAG phosphor (Ce doped) in which a YAG phosphor is dispersed in an alumina inorganic medium, but is not limited to this, and a phosphor plate 31 according to the desired emission color can be used. For example, a phosphor plate such as a glass / α-sialon phosphor that emits amber light, a glass / β-sialon phosphor that emits green light, or a glass / YAG phosphor that emits white light can be used. Note that a light diffusing material such as hollow glass microbeads, yttrium phosphate (Y3PO4), or titanium oxide (TiO2) can also be added to the phosphor plate.

[0026] In this embodiment, the light-emitting element 21 and the phosphor plate 31 have a rectangular parallelepiped shape, and the cross sections perpendicular to the light-emitting element 21 and the phosphor plate 31 have the same size (i.e., length in both vertical and horizontal directions), and are aligned and bonded together so that they form a single rectangular parallelepiped shape as a whole.

[0027] That is, it is preferable that the bonding surfaces of the light emitting element 21 and the phosphor plate 31 have the same shape and size, and are aligned and bonded so that their bonding surfaces match. In this case, no step is created between the light emitting element 21 and the phosphor plate 31 at the bonding portion, preventing unintended light leakage and stray light.

[0028] The light incident surface 31F of the phosphor plate 31 has an area equal to or greater than that of the light extraction surface 21E of the light-emitting element 21, and is bonded so that the light extraction surface 21E is encompassed by the light incident surface 31F in a top view (when viewed along the central axis CZ of the light-emitting device 10). The length of a side of the light incident surface 31F of the phosphor plate 31 does not exceed 103% of the length of the side of the light extraction surface 21E of the corresponding light-emitting element 21. This is because if the length of a side of the light incident surface 31F exceeds approximately 103% of the length of the side of the corresponding light extraction surface 21E, the lower end of the side of the phosphor plate 31 will become dark.

[0029] It is also preferable that the light incident surface 31F of the phosphor plate 31 and the light extraction surface 21E of the light emitting element 21 have similar shapes, and that the light emitting element 21 and the phosphor plate 31 are bonded together such that their axial directions are aligned in a plane (bonding surface) that is coaxial with the central axis CZ of the light emitting device 10 and perpendicular to the central axis CZ. Here, "aligning their axial directions in a plane perpendicular to the central axis CZ" means, for example, that when both bonding surfaces are rectangular, their long sides and short sides are aligned in the same direction.

[0030] Although the light emitting element 21 and the phosphor plate 31 have been described as having a rectangular flat plate shape (rectangular column shape), they may also have a disk shape (including an oval plate shape). For example, when the light emitting element 21 and the phosphor plate 31 have an oval column shape, it is sufficient that the major and minor axes of both adhesive surfaces are aligned.

[0031] (1) Structure of the light-shielding film 3 is a partially enlarged cross-sectional view showing an enlarged cross section of the outer edge portion including the side surface 31S of the phosphor plate 31 of the light conversion unit 30. Also shown are incident light La, Lb, Lcr, and Ldr onto the side surface 31S of the phosphor plate 31, and incident light Lc and Ld onto the light-shielding film 35 (arrows).

[0032] The light-shielding film 35 of the phosphor plate 31 is made of two dielectric films with different refractive indices. In this embodiment, the light-shielding film 35 has a multilayer reflective film 35A (dielectric multilayer film) in which alumina (Al2O3) films as first dielectric films 35p and titanium oxide (TiO2) films as second dielectric films 35q are alternately stacked in large numbers.

[0033] The first dielectric film 35p and the second dielectric film 35q each have a film thickness of λ / 4, where λ is the wavelength within the medium. Each of the first dielectric film 35p and the second dielectric film 35q is formed with, for example, 25 to 30 layers (n=25 to 30). The total thickness of the first dielectric film 35p and the second dielectric film 35q is approximately 5 μm.

[0034] The light-shielding film 35 also has a third dielectric film 35B as its outermost layer. The third dielectric film 35B is made of the same alumina (Al2O3) film as the first dielectric film 35p, and has a film thickness equal to or greater than one wavelength (wavelength within the medium: λ) of light at the long wavelength end of the light (fluorescence) emitted by the phosphor plate 31.

[0035] The third dielectric film 35B functions as a light reflecting film. It is preferable that the third dielectric film 35B is made of one of the first dielectric film 35p and the second dielectric film 35q, which has a refractive index with a critical angle with air of less than 60°. The third dielectric film 35B may be made of a different dielectric material from the first dielectric film 35p and the second dielectric film 35q. The third dielectric film 35B may be omitted if the required reflectance can be obtained by the multilayer reflective film 35A alone.

[0036] It should be noted that known materials can be used for the dielectric film of the light-shielding film 35. Specifically, at least two of Al2O3, TiO2, silicon oxide (SiO2), tantalum oxide (Ta2O3), niobium oxide (Nb2O3), magnesium oxide (MgO), hafnium oxide (HfO2), etc. can be appropriately selected and combined for use.

[0037] The light-shielding film 35 prevents light from leaking from the light-shielding surface 31E (upper surface) of the phosphor plate 31.

[0038] 2, the side surfaces of the light-emitting element 21 and the element electrode surface 21F excluding the element electrodes 23A and 23B are covered with a light-shielding film 25 having the same configuration as the light-shielding film 35 of the phosphor plate 31. In other words, although the element electrodes 23A and 23B are exposed from the light-shielding film 25, the surfaces other than the light extraction surface 21E are covered with the light-shielding film 25.

[0039] Although not shown in the figure, the light-shielding film 25 of the light-emitting element 21 has a dielectric multilayer film (multilayer reflective film) in which two dielectric films (a first dielectric film and a second dielectric film) with different refractive indices are alternately stacked, and a dielectric film (a third dielectric film) as the outermost layer of the light-shielding film 25 outside the dielectric multilayer film.

[0040] The light-shielding film 25 prevents light from leaking from the side and bottom surfaces of the light-emitting element 21. It also prevents stray light from the lower edge formed by the side and bottom surfaces of the light-emitting element 21 and the corner formed by the two side surfaces and bottom surface.

[0041] The light-shielding film 25 of the light-emitting element section 20 and the light-shielding film 35 of the light conversion section 30 are provided individually for the light-emitting element 21 and the phosphor plate 31. Therefore, the material, film thickness, number of pairs, total thickness, etc. of the dielectric multilayer film used for the light-shielding film 25 and the light-shielding film 35 can be appropriately set for each light-emitting element 21 and phosphor plate 31. For example, an Al2O3 / SiO2 laminated film can be used for the light-shielding film 25 of the light-emitting element 21, and an Al2O3 / TiO2 laminated film can be used for the light-shielding film 35 of the phosphor plate 31.

[0042] (2) Stray light suppression and light distribution using light-shielding film 3 and 4, the suppression of stray light by the light-shielding film 35 and the light distribution from the side surface 31S of the phosphor plate 31 will be described. Fig. 4 is a diagram showing the results of a simulation of the reflectance (%) of the light-shielding film 35 versus the incident wavelength (nm).

[0043] 4 shows the reflectance when the incident angle θin on the light-shielding film 35 is set as a parameter (θin=0°, 20°, 40°, 60°). The first dielectric film 35p and the second dielectric film 35q are made of Al2O3 films and TiO2 films, respectively, and 25 layers of each film (i.e., 25 pairs) are stacked. The third dielectric film 35B is made of an Al2O3 film with a thickness of 800 nm.

[0044] As shown in Figure 4, when the incident angle θin exceeds 60° (θin > 60°), a high reflectance of 90% or more can be obtained over the entire wavelength (in vacuum) range of 400 to 800 nm. Therefore, the effective reflection angle θrd will be described as 60°. Furthermore, the critical angle at the side surface 31S of the phosphor plate 31, i.e., the Al2O3 / air interface, is θra = 36°.

[0045] 3, incident light La having an incident angle θside to side surface 31S of phosphor plate 31 of less than 36° (0°≦θside<36°) is emitted to the outside (air) from side surface 31S. Incident light Lb having an incident angle θside to side surface 31S of phosphor plate 31 of 36° or more (36°≦θside) is reflected (total internal reflection) by side surface 31S and returns to the inside of phosphor plate 31.

[0046] Incident light (not shown) whose incident angle θin to the light-shielding film 35 is 60° or less (effective reflection angle) is reflected by the light-shielding film 35 and returns to the inside of the phosphor plate 31. Incident light Lc whose incident angle θin to the light-shielding film 35 is greater than 54° (= 90° - 36°) and is 60° or less is reflected by the light-shielding film 35 (reflected light Lcr). The reflected light Lcr becomes incident light whose incident angle θside to the side surface 31S is 30° or more and less than 36°, and is emitted to the outside from the side surface 31S.

[0047] Incident light Ld having an incident angle θin to the light-shielding film 35 of 60° or more (60°≦θin) is reflected by the multilayer reflective film 35A of the light-shielding film 35, or the light components (dashed dotted lines) not reflected by the multilayer reflective film 35A are reflected by the third dielectric film 35B, becoming incident light Ldr having an incident angle θside to the side surface 31S of 30° or less (0°≦θside≦30°), which is emitted to the outside from the side surface 31S.

[0048] The light that returns to the inside of phosphor plate 31 due to these reflections repeats internal reflections, eventually becoming light La, Lb, Lc, and Ld, which are then emitted to the outside. Therefore, the light that enters phosphor plate 31 is emitted from side surface 31S of phosphor plate 31, preventing light from leaking from light-shielding surface 31E (upper surface).

[0049] (3) Manufacturing method of light emitting device (3.1) Light-emitting element A method for manufacturing the light emitting element section 20 will be described below with reference to FIG.

[0050] (Step SE1) An element substrate 21EP on which a plurality of light emitting elements 21 are arranged is prepared.

[0051] (Step SE2) The element substrate 21EP is attached to an expandable sheet ES, and is then diced to separate it into individual pieces.

[0052] (Step SE3) The expandable sheet ES is stretched and separated into the individual light emitting elements 21.

[0053] (Step SE4) The light emitting elements 21 are aligned on the heat-resistant lower sheet LS, and then the perforated upper sheet US having holes HL is attached onto the array of light emitting elements 21.

[0054] (Step SE5) A dielectric multilayer film is formed as a light-shielding film 25 on the side surfaces and the bottom surface of the light-emitting element 21 excluding the first and second element electrodes 23A and 23B by ALD (atomic layer deposition).

[0055] (Step SE6) The heat-resistant lower sheet LS and the perforated upper sheet US are removed, and the plurality of light-emitting element units 20 are completed.

[0056] (3.2) Optical conversion unit A method for manufacturing the optical conversion section 30 will now be described with reference to FIG. (Step SP1) A parallel flat phosphor plate PP is prepared and placed on the heat-resistant lower sheet LS.

[0057] (Step SP2) A dielectric multilayer film RF is formed as a light-shielding film on the upper and side surfaces of the phosphor plate PP by the ALD method.

[0058] (Step SP3) The phosphor plate PP is divided into individual pieces by dicing.

[0059] (Step SP4) The heat-resistant lower sheet LS is stretched and separated into a plurality of light conversion parts 30. When the heat-resistant lower sheet LS is removed, a plurality of light conversion parts 30 are completed.

[0060] (3.3) Adhesion of the light-emitting element and the light-conversion element 7, (i) an adhesive (adhesive layer 12) is applied (stamped) to the back surface of the phosphor plate 31 of the light conversion unit 30. Next, (ii) the light conversion unit 30 with the adhesive layer 12 attached is attached to the upper surface of the light emitting element unit 20. Through these steps, the light emitting device 10 is completed.

[0061] As described above in detail, according to this embodiment, it is possible to provide a side-emitting semiconductor light-emitting device that prevents leakage light and stray light and has excellent light distribution characteristics in the lateral direction.

[0062] (4) Variation 1 8 is a cross-sectional view schematically showing a light emitting device 50 according to Modification 1 of the first embodiment. The light emitting device 50 according to Modification 1 differs from the light emitting device 10 according to the first embodiment in that it has an inverted convex phosphor plate 31. The other configurations are the same as those of the light emitting device 10 according to the first embodiment.

[0063] More specifically, phosphor plate 31 of light emitting device 50 is made up of rectangular flat phosphor plate 31A and rectangular flat phosphor plate 31B. Phosphor plate 31 has a light incident surface 31F and a light blocking surface 31E facing light incident surface 31F.

[0064] One surface of the phosphor plate 31A, the light incident surface 31F, has the same shape (rectangular) and size as the light extraction surface 21E of the light-emitting element 21, and is aligned and bonded so that the bonding surfaces of the light-emitting element 21 and the phosphor plate 31A coincide.

[0065] Phosphor plate 31B has a larger area (plane perpendicular to central axis CZ) than phosphor plate 31A, and is joined to phosphor plate 31A so as to be coaxial with central axis CZ. One surface of phosphor plate 31B, light-shielding surface 31E, is provided with a light-shielding film 35 that covers the entire surface of light-shielding surface 31E.

[0066] The inverted convex phosphor plate 31 may be formed by processing a phosphor such that a part of the phosphor of a parallel plate having a rectangular shape has the convex shape of the phosphor plate 31A.

[0067] The light emitting device 50 of the present modified example 1 can provide a semiconductor light emitting device having a light distribution characteristic in the lateral direction different from that of the light emitting device 10 of the first embodiment. In addition, it can provide a side-emitting semiconductor light emitting device that prevents leakage light and stray light, has high brightness, and has excellent light distribution characteristic in the lateral direction.

[0068] [Second embodiment] A light-emitting module including the light-emitting device of the first embodiment will be described in detail below with reference to the drawings.

[0069] (1) Example (1.1) Example 1 9A is a perspective view schematically illustrating a light-emitting module 60 of Example 1 (EX1) of the second embodiment. The light-emitting module 60 of Example 1 includes the light-emitting device 10 of the first embodiment and a mounting substrate 61 made of gray aluminum nitride (AlN) on which the light-emitting device 10 is mounted.

[0070] The element electrodes 23A and 23B of the light emitting element 21 are electrically connected to a pair of mounting electrodes (not shown) provided on the mounting substrate 61.

[0071] The light emitting device 10 emits white light from the side surface 31S of the phosphor plate 31. A portion of the light emitted from the phosphor plate 31 is absorbed (dimmed) and reflected on the surface of the mounting substrate 61, which determines the light distribution characteristics of the light emitting module 60. The mounting substrate 61 can be a gray ceramic substrate such as gray aluminum nitride or gray alumina, or a gray or green glass epoxy substrate.

[0072] (1.2) Example 2 9B is a perspective view schematically illustrating a light-emitting module 65 of Example 2 (EX2) of the second embodiment. The light-emitting module 65 of Example 2 uses a mounting substrate 66 with a diffusely reflective white surface instead of the mounting substrate 61 of Example 1 (EX1), and the light-emitting device 10 of the first embodiment is mounted on the mounting substrate 66 made of AlN with a white reflective film containing titanium oxide particles.

[0073] A white substrate with a diffusely reflective surface can be used for the mounting substrate 66. Note that the mounting substrate 66 can be a ceramic or glass epoxy substrate with a white reflective film containing alumina (Al2O3) or zirconia (ZrO2) particles, or a ceramic substrate made of reflective white alumina or zirconia.

[0074] The element electrodes 23A and 23B of the light emitting element 21 are electrically connected to a pair of mounting electrodes (not shown) provided on the mounting substrate 66.

[0075] In this second embodiment, the mounting substrate 66 of the light-emitting module 65 is made of a diffusely reflective white material on the surface, which improves the light output (total luminous flux) and also improves the upward directivity of the light distribution characteristics.

[0076] (1.3) Example 3 10A is a perspective view schematically illustrating a light-emitting module 70 of Example 3 (EX3) of the second embodiment. The light-emitting module 70 of Example 3 uses the light-emitting device 50 of Variation 1 of the first embodiment instead of the light-emitting device 10 of the light-emitting module 60 of Example 1.

[0077] That is, the light emitting module 70 has a gray diffusely reflective mounting substrate 61 and a light emitting device 50 mounted on the mounting substrate 61.

[0078] (1.4) Example 4 10B is a perspective view schematically illustrating a light-emitting module 75 of Example 4 (EX4) of the second embodiment. The light-emitting module 70 of Example 4 uses the light-emitting device 50 of Variation 1 of the first embodiment instead of the light-emitting device 10 of the light-emitting module 65 of Example 2.

[0079] That is, the light emitting module 75 has a mounting substrate 66 with a diffusely reflective white surface, and a light emitting device 50 mounted on the mounting substrate 66 .

[0080] (1.5) Example 5 11 is a perspective view schematically illustrating a light-emitting module 80 of Example 5 (EX5) of the second embodiment. The light-emitting module 80 of Example 5 has a mounting substrate 66 made of aluminum nitride coated with a white resin similar to that of Example 1, and has a diffusely reflective surface. A plurality of light-emitting devices 10 of the first embodiment are mounted on the mounting substrate 66.

[0081] (2) Light distribution characteristics The following describes the measurement results of the light distribution characteristics of the light-emitting modules of Example 1 (EX1) to Example 4 (EX4).

[0082] 12A and 12B are diagrams showing the measurement results of the light distribution characteristics of the light-emitting module 60 of Example 1 (EX1) and the light-emitting module 65 of Example 2 (EX2), respectively. The light-emitting element 21 of the light-emitting device 10 mounted on the mounting substrate 61 and the mounting substrate 66 had a size of 0.73 mm (width and depth) and a height of 150 μm. The phosphor plate 31 had a size of 0.74 mm (width and depth) and a height of 180 μm. As a comparative example, measurements were also performed on a light-emitting module (not shown) in which light-emitting elements were mounted on the mounting substrate 61 and the mounting substrate 66, which differed from the light-emitting device 10 only in that the light-shielding film 35 was provided on the side surface 31S rather than on the top surface (light-shielding surface 31E).

[0083] 12A, in the light-emitting module 60 of Example 1, a gull-wing lateral light distribution characteristic was obtained, in which the light flux axis had an angle θ of approximately 60° with respect to the vertical direction (the direction of the central axis CZ). Note that in the light-emitting module of the comparative example, a good light distribution characteristic of Lambertian light distribution was obtained.

[0084] 12B, in the light-emitting module 65 of Example 2, a gull-wing-shaped light distribution characteristic of lateral light distribution with an angle θ of approximately 45° with respect to the vertical direction was obtained. This is because the light emitted from the light-emitting device 10 toward the mounting substrate 66 was reflected, increasing the amount of light in the forward direction.

[0085] The luminous flux of the light-emitting module 60 of Example 1 was 178 lm, an improvement of approximately 27%, compared to 141 lm for the light-emitting module of the comparative example having a Lambertian light distribution. The luminous flux of the light-emitting module 65 of Example 2 was 183 lm, an improvement of approximately 30% compared to the light-emitting module of the comparative example. Thus, the light-emitting modules 60 and 65 of this example can achieve improved luminous flux and gull-wing-shaped lateral light distribution characteristics. To achieve such optical characteristics, the side surface ratio Rside (area ratio of the side surface 31S to the light-shielding surface 31E, which is the upper surface) of the light-emitting device 10 is preferably 0.85 to 1.15. The preferred side surface ratio Rside is 0.9 to 1.1. The preferred side surface ratio Rside is 1±0.05. The side surface ratio Rside of the light-emitting device 10 used in the light-emitting modules of Examples EX1 and EX2 was 0.97 {(0.18 × 0.74 × 4) ÷ (0.74 × 0.74)}.

[0086] 13A and 13B are diagrams showing the measurement results of the light distribution characteristics of light-emitting module 70 of Example 3 (EX3) and light-emitting module 75 of Example 4 (EX4), respectively. The light-emitting element 21 of light-emitting device 50 of Modification 1 mounted on mounting substrate 61 and mounting substrate 66 had a size of 0.73 mm (width and depth) and a height of 150 μm. Furthermore, the size of phosphor plate 31A was 0.74 mm (width and depth) and a height of 90 μm, and the size of phosphor plate 31B was 0.80 mm (width and depth) and a height of 90 μm. Therefore, the side surface ratio Rside of light-emitting device 50 is 0.87.

[0087] 13A, in the light-emitting module 70 of Example 3, a gull-wing lateral light distribution characteristic with an angle θ of approximately 65° with respect to the vertical direction was obtained. A light distribution characteristic in which the light was distributed further to the side than in the light-emitting module 60 of Example 1 (FIG. 12A) using the same mounting board 61 was obtained.

[0088] 13B, in the light-emitting module 75 of Example 4, a gull-wing lateral light distribution characteristic with an angle θ of approximately 55° with respect to the vertical direction was obtained. A light distribution characteristic in which the light was distributed further to the side than in the light-emitting module 60 of Example 2 (FIG. 12B) which used the same mounting board 66 was obtained.

[0089] The luminous flux of the light emitting module 70 of Example 3 was 148 (lm) compared to 141 (lm) of the light emitting module of the comparative example having a Lambertian light distribution, which was improved by approximately 5.4%. The luminous flux of the light emitting module 75 of Example 4 was 117 (lm), which was reduced by approximately 17% compared to the light emitting module of the comparative example.

[0090] As described above in detail, the present disclosure can provide a side-emitting semiconductor light-emitting device and light-emitting module that have high brightness and excellent light distribution characteristics in the lateral direction.

[0091] [Third embodiment] Hereinafter, a lamp assembly including a light emitting device and a light emitting module according to first and second embodiments will be described in detail with reference to the drawings.

[0092] Figures 14A and 14B are a plan view and a cross-sectional view, respectively, of a third embodiment of the lamp assembly 100. More specifically, Figure 14B schematically shows a cross section taken along line AA shown in Figure 14A, and Figure 14A shows the interior of the lamp assembly 100 as seen along line BB shown in Figure 14B.

[0093] The lamp assembly 100 includes the light emitting module 80 of Example 5 (EX5) of the second embodiment. The lamp assembly 100 also includes a reflector 101 that is a multifaceted reflector, and a light guide plate 103 that is textured.

[0094] More specifically, a plurality of (three in this embodiment) light emitting devices 10 of the first embodiment are mounted on a mounting substrate 66. The three light emitting devices 10 are mounted and arranged at a fixed interval DX along the longitudinal direction (x direction) of the rectangular mounting substrate 66, which has a white resin film formed on the surface of aluminum nitride. Furthermore, one side surface (light emitting surface) of each of the light emitting devices 10 is arranged parallel to the arrangement direction of the three light emitting devices 10.

[0095] The light guide plate 103 is provided parallel to the arrangement direction (x direction) of the three light emitting devices 10. The reflector 101 is provided facing the light guide plate 103 on the opposite side of the three light emitting devices 10 from the light guide plate 103. The light guide plate 103 is provided at a distance DY from the center of the light emitting device 10.

[0096] Light (direct light) emitted from the side surface of the light guide plate 103 of the light emitting device 10 is emitted to the outside through the light guide plate 103. Furthermore, light emitted from the side surface of the light emitting device 10 facing the reflector 101 is reflected by the reflector 101, and the reflected light is emitted to the outside through the light guide plate 103. Therefore, the direct light from the light emitting device 10 and the reflected light from the reflector 101 are emitted as emitted light LA ​​of the lamp assembly 100.

[0097] FIG. 15A shows the luminance (cd / m) of the light-emitting surface (surface) of the light guide plate 103 of the lamp assembly 100 (EX-A) of this embodiment. 2 10 is a graph showing the results of measuring the luminance / along the arrangement direction (x direction) of three light emitting devices 10. The graph also shows the luminance of a comparative example (CX-A) lamp assembly in which three light emitting devices having a Lambertian light distribution are mounted, which differs only in that the light-shielding film 35 is provided on the side surface 31S rather than on the top surface (light-shielding surface 31E).

[0098] 15B is a diagram showing the in-plane luminance distribution of the light-emitting surface of the lamp assembly 100 (EX-A) in comparison with the in-plane luminance distribution of the lamp assembly of the comparative example (CX-A). Note that the darker the gray, the higher the luminance. Furthermore, positions in the arrangement direction x>0 are indicated as R (right), and positions x<0 are indicated as L (left).

[0099] In the lamp assembly 100, the three light emitting devices 10 were arranged at a distance DX of 15 mm, and the light guide plate 103 was arranged at a distance DY of 20 mm from the light emitting devices 10. The arrangement of the light emitting devices and the light guide plate in the lamp assembly of the comparative example was also similar.

[0100] 15A and 15B, the lamp assembly of the comparative example (CX-A) has high-brightness areas resulting from the light emitted from the three light-emitting devices. In contrast, the lamp assembly 100 (EX-A) has a nearly constant brightness distribution, demonstrating that a lamp assembly with uniform surface emission has been achieved.

[0101] As described above in detail, the present disclosure can provide a side-emitting semiconductor light-emitting device that has high brightness and excellent light distribution characteristics in the lateral direction, as well as a light-emitting module and lamp assembly in which multiple semiconductor light-emitting devices are arranged and that has a uniform brightness distribution. [Explanation of symbols]

[0102] 10,50: Light-emitting device 12: Adhesive layer 20: Light emitting element 21: Light-emitting element 21A: Circuit board 21B: Light-emitting semiconductor layer 21E: Light extraction surface 21F: Element electrode surface 21K:Active layer 23A, 23B: element electrodes 25: Light shielding film 30: Optical conversion unit 31: Phosphor plate 31E: Light shielding surface 31F: Light incidence surface 31S: Side (light exit surface) 35: Light shielding film 35A: Multilayer reflective film 35B: Third dielectric film 60, 65, 70, 75, 80: Light-emitting module 61, 66: Mounting board 100: Lamp assembly 101: Reflector 103: Light guide plate CZ: Center axis DX,DY: Interval

Claims

1. a light emitting element including a light emitting semiconductor layer provided on one surface of a flat substrate and a pair of element driving electrodes provided on the surface of the light emitting semiconductor layer; a light conversion member bonded to the other surface of the flat substrate with a light-transmitting adhesive member, a first light-shielding film is provided on the light-emitting element, the first light-shielding film covering the light-emitting element except for the other surface of the flat substrate and an area where the pair of element driving electrodes are formed; the light converting member is provided with a second light-shielding film that covers the entire surface of the light converting member that faces the adhesive surface bonded by the adhesive member; the adhesive surface of the light converting member has a size equal to or larger than the size of the other surface of the flat substrate; Semiconductor light-emitting device.

2. The semiconductor light emitting device according to claim 1 , wherein the light converting member emits light in the visible light range from a side surface of the light converting member.

3. 2. The semiconductor light emitting device according to claim 1, wherein the light converting member has an aspect ratio, which is the ratio of the area of ​​the side surface to the area of ​​the top surface of the light converting member, of 0.85 to 1.

15.

4. 3. The semiconductor light emitting device according to claim 2, wherein the first light shielding film and the second light shielding film are dielectric multilayer films that reflect light in the visible light range.

5. 2. The semiconductor light emitting device according to claim 1, wherein the first light shielding film and the second light shielding film are dielectric multilayer films that reflect the light emitted by the light emitting element and the light emitted by the light converting member, respectively.

6. 6. The semiconductor light emitting device according to claim 5, wherein the thickness of the outermost layer of the second light shielding film is equal to or greater than one wavelength of light at the longest wavelength end of the light emitted by the light converting member.

7. The second light-shielding film is Al ２ O ３ , SiO ２ , HfO ２ , TiO ２ , Ta ２ O ３ and Nb ２ O ３ 6. The semiconductor light emitting device according to claim 5, wherein the semiconductor light emitting device is a combination of at least two of the above.

8. At least one semiconductor light emitting device according to any one of claims 1 to 7; a mounting substrate having a diffusely reflective surface; The at least one semiconductor light emitting device is mounted on the surface of the mounting substrate.

9. a plurality of semiconductor light emitting devices according to any one of claims 1 to 7; a mounting substrate having a diffusely reflective surface; the plurality of semiconductor light emitting devices are arranged at regular intervals in one direction and mounted on the surface of the mounting substrate.

10. The light-emitting module according to claim 8 , wherein the surface of the mounting substrate is white.

11. a light-emitting module in which a plurality of semiconductor light-emitting devices according to any one of claims 1 to 7 are arranged at regular intervals in one direction on a mounting substrate having a diffusely reflective surface; a light guide plate arranged parallel to the arrangement direction of the plurality of semiconductor light emitting devices; a reflector provided on the opposite side of the light guide plate with respect to the plurality of semiconductor light emitting devices.

12. 12. The lamp assembly of claim 11, wherein the surface of the mounting substrate is white.

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