Light-emitting device

Abstract

To provide a light-emitting device in which luminance unevenness is reduced.SOLUTION: A light-emitting device includes a light-emitting element including a semiconductor multilayer body having an upper surface, a lower surface on the opposite side of the upper surface, and side surfaces between the upper surface and the lower surface, and a pair of electrodes disposed on the lower surface, a light-transmitting member that covers the upper surface of the semiconductor multilayer body, and a covering member that continuously covers the lower surface of the semiconductor multilayer body and a lower surface of the light-transmitting member and exposes a part of the pair of electrodes. The covering member includes a first covering member with a light reflecting property in contact with the semiconductor multilayer body and the light-transmitting member, and a second covering member with a light absorbing property disposed at a position overlapping with the semiconductor multilayer body through the first covering member in a plan view.SELECTED DRAWING: Figure 1C

Description

[Technical field]

[0001] The present disclosure relates to a light emitting device. [Background technology]

[0002] A structure is known that reduces the amount of light emitted directly above a light emitting device, thereby preventing the area directly above the light emitting device from becoming too bright (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-173849 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of an embodiment of the present disclosure is to provide a light emitting device with reduced luminance unevenness. [Means for solving the problem]

[0005] Embodiments of the present disclosure include the following configurations. a light emitting element including a semiconductor laminate including an upper surface, a lower surface opposite to the upper surface, and a side surface between the upper surface and the lower surface, and a pair of electrodes disposed on the lower surface; a light-transmitting member covering the upper surface of the semiconductor laminate; a covering member that continuously covers a lower surface of the semiconductor laminate and a lower surface of the light-transmitting member and exposes a portion of the pair of electrodes; Equipped with The light emitting device, wherein the covering member comprises a light reflective first covering member in contact with the semiconductor laminate and the light-transmitting member, and a light absorbing second covering member arranged via the first covering member in a position overlapping the semiconductor laminate in a planar view. Effect of the Invention

[0006] According to the embodiment of the present disclosure, it is possible to provide a light emitting device with reduced luminance unevenness. [Brief description of the drawings]

[0007] [Figure 1A] FIG. 1 is a schematic perspective view of a light emitting device according to an embodiment of the present disclosure. [Figure 1B] FIG. 2 is a schematic bottom view of the light emitting device according to the embodiment of the present disclosure. [Figure 1C] 1C is a schematic cross-sectional view taken along line IC-IC shown in FIG. 1B. [Diagram 2] 10 is a schematic cross-sectional view of a modified example of the light emitting device according to the embodiment of the present disclosure. [Figure 3A] 5A to 5C are schematic cross-sectional views of a method for manufacturing a light-emitting device according to an embodiment of the present disclosure. [Figure 3B] 5A to 5C are schematic cross-sectional views of a method for manufacturing a light-emitting device according to an embodiment of the present disclosure. [Figure 4A] 10 is a schematic cross-sectional view of a modified example of the light emitting device according to the embodiment of the present disclosure. [Figure 4B] 10 is a schematic cross-sectional view of a modified example of the light emitting device according to the embodiment of the present disclosure. [Figure 5A] 5A to 5C are schematic cross-sectional views of a method for manufacturing a light-emitting device according to an embodiment of the present disclosure. [Figure 5B] 5A to 5C are schematic cross-sectional views of a method for manufacturing a light-emitting device according to an embodiment of the present disclosure. [Figure 6A] FIG. 13 is a schematic bottom view of a modified example of the light emitting device according to the embodiment of the present disclosure. [Figure 6B] FIG. 6B is a schematic cross-sectional view taken along line VIB-VIB shown in FIG. 6A. [Figure 7A] FIG. 2 is a schematic top view of a light emitting device according to an embodiment of the present disclosure. [Figure 7B] FIG. 7B is a schematic cross-sectional view taken along line VIIB-VIIB shown in FIG. 7A. [Figure 7C] FIG. 2 is a schematic bottom view of the light emitting device according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. In the following description, terms indicating specific directions or positions (for example, "up", "down", "right", "left" and other terms including these terms) will be used as necessary. The use of these terms is for the purpose of facilitating understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of these terms. In addition, a plan view refers to a view from the top or bottom. In addition, parts with the same reference numerals appearing in multiple drawings indicate the same parts or members. In addition, resin members such as coating members will be described using the same name regardless of whether they are molded, solidified, cured, or divided into individual pieces. In other words, members whose state changes depending on the process stage, such as when they are liquid before molding, become solid after molding, and further when the solid after molding is divided into small solid pieces with a changed shape, will be described using the same name.

[0009] The light emitting device of the embodiment comprises a light emitting element comprising a semiconductor laminate having an upper surface, a lower surface opposite the upper surface, and a side surface between the upper surface and the lower surface, a pair of electrodes arranged on the lower surface, a translucent member covering the upper surface of the semiconductor laminate, and a covering member continuously covering the lower surface of the semiconductor laminate and the lower surface of the translucent member and exposing portions of the pair of electrodes, the covering member comprising a light reflective first covering member in contact with the semiconductor laminate and the translucent member, and a light absorbing second covering member arranged via the first covering member in a position overlapping the semiconductor laminate in a planar view.

[0010] (Embodiment 1) <Light emitting device> 1A to 1C are schematic diagrams showing a light emitting device 100 according to the first embodiment. The light emitting device 100 includes a light emitting element 110, a light-transmitting member 120, and a covering member 130. The light emitting element 110 includes a semiconductor laminate 111 and a pair of positive and negative electrodes 112. The semiconductor laminate 111 includes an upper surface 111U, a lower surface 111D opposite to the upper surface 111U, and a side surface 111S between the upper surface 111U and the lower surface 111D. The pair of electrodes 112 are disposed on the lower surface 111D of the semiconductor laminate 111. The light-transmitting member 120 covers the upper surface 111U and the side surface 111S of the semiconductor laminate 111. The covering member 130 continuously covers the lower surface 111D of the semiconductor laminate 111 and the lower surface of the light-transmitting member 120. The lower surfaces of the pair of electrodes 112 are exposed from the covering member 130. The covering member 130 includes a light-reflective first covering member 131 that contacts the semiconductor laminate 111 and the light-transmitting member 120, and a light-absorbing second covering member 132 that is arranged via the first covering member 131 at a position that overlaps the semiconductor laminate 111 in a planar view.

[0011] The covering member 130 has the light-absorbing second covering member 132, and thus the light emitted from the light-emitting element 110 can be absorbed by the second covering member 132. This prevents the area directly above the light-emitting element 110 from becoming too bright, and reduces luminance unevenness. Each component will be described in detail below.

[0012] (Light emitting element) The light emitting device 100 includes at least one light emitting element 110. For example, a semiconductor light emitting element such as a light emitting diode can be used as the light emitting element 110. The light emitting element 110 includes a semiconductor laminate 111 and a pair of positive and negative electrodes 112. The semiconductor laminate 111 includes, for example, an element substrate such as sapphire and a semiconductor layer formed thereon. Alternatively, the semiconductor laminate 111 can be formed of only a semiconductor layer without an element substrate. The shape of the light emitting element 110 in plan view can be a polygon such as a triangle, a rectangle, or a hexagon. The size of the light emitting element 110 can be, for example, 100 μm or more and 3000 μm or less in plan view. Specifically, the light emitting element 110 can be a square with one side of about 600 μm, about 1400 μm, or about 1700 μm. The light emitting element 110 may also be a rectangle having long and short sides in plan view. For example, the size can be 1100 μm×200 μm.

[0013] The semiconductor laminate 111 includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting layer sandwiched between them. x Al y Ga 1-x-y N (0≦x, 0≦y, x+y≦1).

[0014] The semiconductor laminate 111 may have a structure including one or more light emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or may have a structure in which a structure including an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer in order is repeated multiple times. When the semiconductor laminate 111 includes multiple light emitting layers, the semiconductor laminate 111 may include light emitting layers having different emission peak wavelengths, or light emitting layers having the same emission peak wavelength. The same emission peak wavelength includes a case where the emission peak wavelength varies by about several nm. The combination of emission peak wavelengths between the multiple light emitting layers can be appropriately selected. For example, when the semiconductor laminate includes two light emitting layers, the light emitting layers can be selected from combinations such as blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light, or green light and red light.

[0015] The light emitting element 110 includes a pair of positive and negative electrodes 112 on the lower surface 111D of the semiconductor laminate 111. The electrodes 112 may be made of a good electrical conductor, for example, gold, silver, tin, platinum, rhodium, titanium, aluminum, tungsten, palladium, nickel, or an alloy thereof. The electrodes 112 may include an ohmic electrode in contact with the lower surface 111D of the semiconductor laminate 111, and a pad electrode connected to the ohmic electrode and connected to the outside. The thickness of the electrodes may be, for example, 10 μm or more and 50 μm or less.

[0016] (Translucent member) The light-transmitting member 120 is a light-transmitting member arranged to cover the upper surface 111U and the side surface 111S of the semiconductor laminate 111 of the light-emitting element 110. Light from the light-emitting element 110 is emitted to the outside through the light-transmitting member 120. In the light-emitting device 100 shown in FIG. 1A and the like, light is emitted to the outside from the upper surface and the side surface of the light-transmitting member 120. The light-transmitting member 120 can be made of a light-transmitting resin, glass, or the like. In particular, a light-transmitting resin is preferable, and a thermosetting resin such as a silicone resin, a silicone-modified resin, an epoxy resin, or a phenolic resin, or a thermoplastic resin such as a polycarbonate resin, an acrylic resin, a methylpentene resin, or a polynorbornene resin can be used. In particular, a silicone resin having excellent light resistance and heat resistance is preferable. The light-transmitting member 120 may be only such a light-transmitting member, or may be made of such a light-transmitting member as a base material, and may contain a phosphor that is excited by light from the light-emitting element and converted into light of a different wavelength, a light scattering agent, or the like.

[0017] Examples of phosphors that can be used include yttrium-aluminum-garnet phosphors, lutetium-aluminum-garnet phosphors, terbium-aluminum-garnet phosphors, CCA phosphors, SAE phosphors, chlorosilicate phosphors, silicate phosphors, oxynitride phosphors such as β-sialon phosphors and α-sialon phosphors, nitride phosphors such as LSN phosphors, BSESN phosphors, SLA phosphors, CASN phosphors and SCASN phosphors, fluoride phosphors such as KSF phosphors, KSAF phosphors and MGF phosphors, quantum dots having a perovskite structure, II-VI group quantum dots, III-V group quantum dots, and quantum dots having a chalcopyrite structure.

[0018] Examples of light scattering agents that can be used include particles of titanium oxide, silicon oxide, aluminum oxide, zinc oxide, magnesium oxide, zirconium oxide, yttrium oxide, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, or glass.

[0019] (Covering material) The covering member 130 is a member that continuously covers the lower surface 111D of the semiconductor laminate 111 of the light emitting element 110 and the lower surface of the light-transmitting member 120. The covering member 130 also covers the side surface of the electrode 112. The covering member 130 includes a light-reflective first covering member 131 and a light-absorbing second covering member 132. The first covering member 131 is disposed at a position where it contacts the semiconductor laminate 111 and the light-transmitting member 120 of the light emitting element 110. The second covering member 132 is disposed at a position where it overlaps with the semiconductor laminate 111 of the light emitting element 110 in a plan view, via the first covering member 131. In other words, the covering member 130 located below the lower surface 111D of the semiconductor laminate 111 has a structure in which the first covering member 131 and the second covering member 132 are laminated.

[0020] First coating member 131 and second coating member 132 are originally the same member. A part of the member that has been irradiated with laser light and altered is second coating member 132, and a part that has not been irradiated with laser light and has not been altered is first coating member 131.

[0021] The covering member 130 includes a base material and particles contained in the base material. The above-mentioned "alteration" includes altering the particles. For example, it includes altering the first particles to become the second particles. An example of a method of alteration is a method of irradiating the first particles with a laser beam (first laser beam described later). This allows the body color of the first particles, which are visually recognized as white, to be altered to the second particles, which are visually recognized as black or gray. In other words, the first covering member 131 includes only the first particles, and the second covering member 132 includes only the second particles or the second particles and the first particles.

[0022] Thermosetting resins such as silicone resin, silicone modified resin, epoxy resin, and phenol resin, and thermoplastic resins such as polycarbonate resin, acrylic resin, methylpentene resin, and polynorbornene resin can be used as the base material of the covering member 130. In particular, silicone resin, which has excellent light resistance and heat resistance, is preferable.

[0023] Examples of the first particles include titanium oxide, zinc oxide, etc. The second particles are those which have been altered, such as altered titanium oxide or altered zinc oxide.

[0024] Furthermore, when the covering member contains resin or glass as the base material, the above-mentioned "alteration" may include alteration of the base material. For example, it includes altering a first base material to form a second base material. An example of a method for alteration is a method of irradiating the first base material with a laser. This can alter the color of the first base material, which is visually perceived as translucent, to the second base material, which is visually perceived as black.

[0025] As described above, by altering the body color, the characteristics of the light emitted from the light emitting element change. Specifically, the altered portion is more likely to absorb light than before the alteration. By disposing the altered member directly below the semiconductor laminate 111 of the light emitting element 110, the light emitted from the light emitting element 110 is absorbed, preventing the area directly above the light emitting element 110 from becoming too bright, and reducing brightness unevenness.

[0026] The covering member 130 that has been irradiated with a laser and has been altered mainly changes its body color as described above, and its surface roughness becomes somewhat larger. In other words, it is considered that a part of the covering member 130 has been removed by irradiating the laser light. However, even if the laser light is irradiated in a line shape, a line-shaped groove is not formed, and fine irregularities are formed over the entire irradiated area. For example, the surface roughness Sa of the first covering member 131 can be, for example, 0.1 μm or more and 0.2 μm or less. The surface roughness Sa of the second covering member 132 can be, for example, 0.1 μm or more and 0.7 μm or less.

[0027] The first covering member 131 has a reflectance of 70% or more for light at the emission peak wavelength of light emitted from the light emitting element 110. The second covering member 132 has a reflectance of 30% or less for light at the emission peak wavelength of light emitted from the light emitting element 110.

[0028] The thickness of the covering member 130 is, for example, 10 μm or more and 60 μm or less. In the region where the first covering member 131 and the second covering member 132 overlap, the thickness of the second covering member 132 is preferably 50% or less of the thickness of the covering member 130. The thickness of the second covering member 132 can be, for example, 3 μm or more and 10 μm or less, and preferably 4 μm or more and 6 μm or less.

[0029] The thickness of the second covering member 132 may be the same throughout, or may have parts of different thicknesses. In addition, the second covering member 132 may be thickest at the center in a plan view, and may become thinner toward the periphery. This allows the change in the light absorption rate of the second covering member 132 to be gradually changed. The parts with different light absorption rates can be obtained by controlling the ratio of the first particles to the second particles by controlling the irradiation conditions of the first laser light B1. Note that if the output of the first laser light B1 is too high, the covering member 130 will be ablated. Therefore, if it is desired to increase the light absorption rate, that is, to increase the ratio of the second particles, it is preferable to increase the number of times the first laser light B1 is irradiated within the output range described below.

[0030] The second covering member 132 may have an area of ​​1% to 50% of the area of ​​the portion overlapping with the semiconductor laminate 111 in a plan view, i.e., the area of ​​the semiconductor laminate 111 minus the area of ​​the pair of electrodes 12). Furthermore, the second covering member 132 is preferably disposed in a portion overlapping with the semiconductor laminate 111 located between the pair of electrodes 112 in a plan view. For example, the second covering member 132 may have an area of ​​30% to 100% of the area of ​​the portion overlapping with the semiconductor laminate 111 located between the pair of electrodes 112. By disposing the second covering member 132 at a position directly below the semiconductor laminate 111 where the light from the light emitting element 110 is most likely to be irradiated, the light can be efficiently absorbed.

[0031] It is preferable that the second covering member 132 is not disposed at a position where it does not overlap with the light emitting element 110 in a plan view. This can reduce the inhibition of the light propagating in the light-transmitting member 120 from being reflected by the first covering member 131. Therefore, it is possible to reduce the decrease in brightness in the vicinity directly above the light emitting element 110. In particular, when the width of the light-transmitting member 120 positioned to the side of the light emitting element 110 is wide, that is, when the distance from the light emitting element 110 to the side surface (outer surface) of the light-transmitting member 120 is long, the first covering member 131 can efficiently reflect the light, making it easier for the light to propagate to the outer surface.

[0032] The shape of the second covering member 132 in a plan view can be, for example, a polygon such as a triangle, a rectangle, or a pentagon, or a shape with rounded corners thereof, or a circle or an ellipse.

[0033] The light emitting device may include a light adjusting member above the light emitting element. In the light emitting device 200 shown in FIG. 2, the light adjusting member 150 is disposed on the upper surface of the light-transmitting member 120 that covers the light emitting element 110. The light adjusting member 150 can adjust the amount and the direction of light emitted from the upper surface of the light-transmitting member 120. The light adjusting member 150 has reflectivity and translucency with respect to the light emitted from the light emitting element 110. A part of the light emitted from the upper surface of the light-transmitting member 120 is reflected by the light adjusting member 150, and the other part is transmitted through the light adjusting member 150. The transmittance of the light adjusting member 150 with respect to the light emitted from the light emitting element 110 is preferably, for example, 1% or more and 50% or less, and more preferably 3% or more and 30% or less. The light adjusting member 150 may be made of the same material as the covering member 130. By providing such a light adjusting member 150, the light emitted from the light emitting element 110 is reflected toward the light emitting element 110, and is thereby more easily absorbed by the second covering member 132.

[0034] <Method of manufacturing the light emitting device> The light emitting device 100 shown in FIG. 1A etc. can be obtained by a manufacturing method including a first step of preparing a light emitting device intermediate 100A having a covering member 130, and a second step of irradiating the covering member 130 of the light emitting device intermediate 100A with a first laser light B1 to cause alteration.

[0035] In detail, the method for manufacturing the light emitting device includes a first step of preparing a light emitting device intermediate including a semiconductor laminate having an upper surface, a lower surface opposite the upper surface, and a side surface between the upper surface and the lower surface, a light emitting element having a pair of electrodes arranged on the lower surface, a light-transmitting member covering the upper surface of the semiconductor laminate, and a light-reflective covering member that continuously covers the lower surface of the semiconductor laminate and the lower surface of the light-transmitting member and exposes portions of the pair of electrodes, and a second step of irradiating laser light to the covering member located between the pair of electrodes to modify it.

[0036] As shown in FIG. 3A, the light emitting device intermediate 100A has a light emitting element 110, a light-transmitting member 120, and a covering member 130. In the light emitting device intermediate 100A, the covering member 130 is composed of a first covering member 131, and does not include a second covering member 132. FIG. 3A illustrates a light emitting device intermediate 100A including a portion that will become a plurality of light emitting devices 100. When using such a light emitting device intermediate 100A, a step of cutting along a cutting line C shown in FIG. 3B before or after irradiation with the first laser light B1 may be included. However, the present invention is not limited to this, and a light emitting device intermediate 100A that will become one light emitting device 100 may be used.

[0037] The light emitting device intermediate 100A is arranged so that the covering member 130 faces upward as shown in FIG. 3A. The first laser light source L1 is arranged above the light emitting device intermediate 100A. This is not a limitation, and the covering member 130 and the first laser light source L1 may be arranged in a position facing each other. The first laser light source L1 moves laterally at a constant distance from the surface facing the upper side of the light emitting device intermediate 100A. Alternatively, the first laser light source L1 may be fixed and the light emitting device intermediate 100A may be moved laterally. The same applies to the second laser light source L2 and the third laser light source L3 described later.

[0038] The first laser light B1 is emitted under conditions capable of altering the properties of the covering member 130 at the portion irradiated with the first laser light B1. The main wavelength, output (intensity), diameter of the irradiation spot, and moving speed of the irradiation spot of the first laser light B1 can be set in consideration of the amount of light to be absorbed by the second covering member 132 according to the material of the covering member 130 and the intensity of the light emitted from the light emitting element 110.

[0039] For example, the case where the covering member 130 is made of a resin material containing titanium oxide and a silicone base material is taken as an example. In this case, it is preferable to use a first laser light source L1 capable of emitting a green laser light having a main wavelength of 532 nm as the first laser light B1. The output of the first laser light source L1 is preferably 0.5 W or more and 0.9 W or less, and is preferably about 0.7 W. The first laser light B1 is emitted by continuous oscillation or pulse oscillation. For example, in the case of pulse oscillation, the heat amount per pulse of the first laser light B1 can be 17 μJ or more and 19 μJ or less. The irradiation spot diameter of the first laser light B1 can be, for example, 15 μm or more and 30 μm or less. The moving speed of the irradiation spot can be, for example, 100 mm / s or more and 1500 mm / s or less. Examples of the first laser light source L1 capable of emitting such a first laser light B1 include second harmonics such as a YAG laser and a YVO4 laser.

[0040] A measuring step of measuring the light emission characteristics of the light emitting device intermediate 100A before irradiating the first laser light B1 can be provided, which allows the conditions of the first laser light B1 to be set according to the light emission characteristics of each light emitting device intermediate 100A.

[0041] (Modification) 4A and 4B, the light emitting device 300 can include a metal film 140 electrically connected to the electrode 112 of the light emitting element 110. The light emitting device 310 shown in Fig. 4A includes a metal film 140 that covers only the lower surface of the electrode 112 exposed from the covering member 130. The light emitting device 320 shown in Fig. 4B continuously covers the lower surface of the electrode 112 exposed from the covering member 130 and a part of the lower surface of the covering member 130.

[0042] The metal film 140 can mainly function as a protective film for reducing corrosion and oxidation of the electrode 112. A material having better corrosion resistance and oxidation resistance than the electrode 112 is selected as the material for the metal film 140. For example, the outermost layer of the metal film 140 is preferably a platinum group metal such as gold or platinum. In addition, when the light emitting device 200 is soldered to a wiring board or the like, it is preferable to use gold, which has good solderability, for the outermost surface of the metal film 140.

[0043] The metal film 140 may be composed of only one layer of a single material, or may be composed of layers of different materials stacked together. Examples of the metal film 140 having a stacked structure are preferably a structure in which gold is arranged on the outermost surface, such as nickel / ruthenium / gold and titanium / platinum / gold. Alternatively, the outermost surface is gold, and ruthenium or the like arranged underneath functions as a diffusion prevention layer that prevents the material that constitutes the electrode from diffusing into the gold, and the thickness of such a diffusion prevention layer is preferably 10 Å or more and 1000 Å or less.

[0044] The thickness of the metal film 140 is preferably, for example, 1 μm or less, and more preferably 1000 Å or less. Moreover, the thickness capable of reducing corrosion of the electrode 112 is preferably, for example, 5 nm or more. Here, the thickness of the metal film refers to the total thickness of the layers when the metal film is configured by stacking multiple layers.

[0045] Moreover, a light emitting device including both the metal film 140 and the light adjusting member 150 described above can be provided.

[0046] In the case of a light emitting device having a metal film 140, the light emitting device intermediate prepared in the above-mentioned second step is a light emitting device intermediate 300A having a metal film 140 continuously covering the electrode 112 of the light emitting element 110 and the covering member 130. Thereafter, before the above-mentioned second step, a step of irradiating the entire surface or a part of the metal film 140 with a second laser light B2 to remove all or a part of the metal film 140 covering the covering member 130 by ablation is provided.

[0047] 5A, a metal film 140 is formed to continuously cover the covering member 130 and the electrode 112. A light emitting device intermediate 300A is prepared. The metal film 140 can be formed by sputtering, vapor deposition, an atomic layer deposition (ALD) method, a metal organic chemical vapor deposition (MOCVD) method, a plasma-enhanced chemical vapor deposition (PECVD) method, an atmospheric pressure plasma deposition method, plating, or the like.

[0048] The second laser light B2 is emitted under conditions that allow the metal film 140 overlapping the covering member 130 to be removed by ablation. The main wavelength, output (intensity), diameter of the irradiation spot, and moving speed of the irradiation spot of the second laser light B2 can be set in consideration of the material of the covering member 130 and the material of the electrode 112. The second laser light B2 can be irradiated to both the portion overlapping with the electrode 112 and the portion overlapping with the covering member 130. The metal film 140 overlapping with the covering member 130 is ablated and removed by the second laser light B2. The metal film 140 overlapping with the electrode 112 remains without being removed even when irradiated with the second laser light B2.

[0049] The covering member 130 is partially removed in the region irradiated with the second laser light B2. For example, when the second laser light B2 is irradiated in a plurality of lines on the entire surface of the metal film 140, a plurality of linear grooves are formed. The width of the groove is about 10 μm to 100 μm, and the depth of the groove is about 0.1 μm to 3 μm. It is considered that such grooves are formed because the covering member 130 is also removed when the metal film 140 is ablated. The covering member 130 having such grooves formed thereon is not altered as in the case of irradiation with the first laser light B1. In the case where the covering member is made of a resin material containing titanium oxide and has silicone as a base material, the covering member 130 before irradiation with the second laser light B2 appears white, and the covering member 130 after irradiation with the second laser light B2 also appears white.

[0050] For example, the case where the covering member 130 is made of a resin material containing titanium oxide and a silicone base material is taken as an example. In this case, it is preferable to use a second laser light source L2 capable of emitting a green laser light having a main wavelength of 532 nm as the second laser light B2. The output of the second laser light source L2 is preferably 1.3 W or more and 1.5 W or less, and more preferably 1.3 W or more and 1.4 W or less. The second laser light B2 is emitted by continuous oscillation or pulse oscillation. For example, in the case of pulse oscillation, the heat amount per pulse of the second laser light B2 can be 16 μJ or more and 18 μJ or less. The irradiation spot diameter of the second laser light B2 can be the second harmonic of the like.

[0051] In this way, by forming the metal film 140 for protecting the electrode 112 in advance, it is possible to reduce deterioration of the electrode 112 when measuring the light emission characteristics.

[0052] Furthermore, as an optional step, the first step or the second step can include a step of irradiating the coated member with a third laser light to form a mark for identification.

[0053] The third laser light is irradiated onto the covering member 130 under conditions that allow removal of a portion of the covering member 130 and formation of a recognizable mark. For example, a mark can be formed by appropriately setting the dominant wavelength, output (intensity), diameter of the irradiation spot, moving speed of the irradiation spot, etc. of the third laser light. Examples of marks include lot marks (lot numbers) that indicate a group of products manufactured at the same time, serial numbers for identifying individual products, and bad marks that indicate products determined to be defective by inspection.

[0054] In the region of the covering member 130 irradiated with the third laser light B3, not only does the covering member 130 change in quality in the same way as the region of the covering member 130 irradiated with the first laser light B1, but also the covering member 130 is removed to a depth of about 6 μm or more to form a recess. For example, in a recognition device used in the recognition process, there are cases where a difference in color or minute unevenness is easily misrecognized. Therefore, by removing the covering member 130 to a certain depth, the covering member 130 can be correctly recognized. Therefore, in the light-emitting device 100 having the structure shown in FIG. 1A, etc., if the third laser light B3 is irradiated to a portion overlapping the light-emitting element 110, the light-emitting element 110 may be affected. Therefore, it is preferable to irradiate the third laser light B3 to a position that does not overlap the light-emitting element 110 in a plan view. The bad mark indicating a defective product can be formed in a large and conspicuous position so that the light-emitting device to which the bad mark is applied is not released. The irradiation of the third laser light B3 can be performed either before or after the irradiation of the first laser light B1.

[0055] For example, the case where the covering member 130 is made of a resin material containing titanium oxide and silicone as a base material is taken as an example. In this case, a green laser light having a main wavelength of 532 nm can be used as the third laser light. The output of the third laser light is preferably 1 W or more and 4 W or less, and preferably, a laser light having an output of about 2 W is irradiated. The third laser light may be a continuous wave or a pulsed wave. For example, in the case of pulsed wave, the heat amount per pulse of the third laser light B3 can be 30 μJ or more and 35 μJ or less. The irradiation spot diameter of the third laser light can be, for example, 15 μm or more and 30 μm or less. The moving speed of the irradiation spot can be, for example, 100 mm / s or more and 1000 mm / s or less. Examples of laser light sources capable of emitting such third laser light include second harmonics such as YAG laser and YVO4 laser.

[0056] As described above, when irradiating three types of laser light with different conditions, the irradiation can be performed in the following four orders. (1) Irradiate the second laser light, the first laser light, and the third laser light in that order. (2) Irradiate the second laser light, the third laser light, and the first laser light in that order. (3) Irradiate the third laser light, the first laser light, and the second laser light in that order. (4) Irradiate the third laser light, the second laser light, and the first laser light in that order.

[0057] When irradiating in the order of (1), first, the light emitting device intermediate is placed in a laser irradiation device and irradiated with the second laser light to form a metal film. After that, the light emitting device intermediate is taken out from the laser irradiation device to measure the light emitting characteristics, the light emitting characteristics are measured in an inspection device, and the conditions of the first laser light according to the light emitting characteristics are determined. Next, the light emitting device intermediate is placed again in the laser irradiation device, and the first laser light is irradiated to a necessary portion to form a second coating member. Then, the third laser light is irradiated in the same laser irradiation device to form a lot mark or a serial number. Since the conditions of the third laser light can be set not limited to the light emitting characteristics, the third laser light can be irradiated without taking out the laser irradiation device after irradiating the first laser light. Therefore, the light emitting device can be efficiently manufactured. Alternatively, after irradiating with the first laser light, the light emitting device intermediate can be taken out from the laser irradiation device, and the light emitting characteristics can be measured again in an inspection device. This allows the light emitting characteristics to be measured in a state in which the second coating member is formed. After that, the light emitting device intermediate is placed in the laser irradiation device again, and the third laser light is irradiated as necessary to form a bad mark.

[0058] When irradiating in the order of (2), the order of irradiation of the first laser light and the third laser light is reversed in the case of irradiating in the order of (1), and it is the same as (1) in that the irradiation of the first laser light and the irradiation of the third laser light can be performed without removing it from the laser irradiation device. Here, before irradiating the first laser light, the light emitting characteristics of the intermediate light emitting device are measured in an inspection device, and the third laser light is irradiated to form a serial number or a bad mark. At this time, a deep recess is formed, so debris is formed on the surface of the coating member. There are cases where there is no problem if the debris is left as it is, but when irradiating the first laser light thereafter, it is also possible to form a second coating member and remove the debris.

[0059] When irradiating in the order of (3), first, the light emitting characteristics of the intermediate light emitting device are measured in an inspection device, and then the third laser light is irradiated to form a lot mark or serial number. At this time, debris is formed on the surface of the coating member as described above. Next, the first laser light according to the light emitting characteristics is irradiated to form a second coating member.

[0060] The irradiation in the order of (4) is the same as (3) in that the emission characteristics of the intermediate light-emitting device are measured in an inspection device, and then the third laser light is irradiated to form a mark and debris. The debris can then be removed when the metal film is formed by irradiating the second laser light.

[0061] In the above (1) to (4), the first laser light may be irradiated without inspecting the light emission characteristics. For example, a case is taken as an example where the thickness of the covering member of the light emitting device intermediate in the lot is found to be thicker than expected as a result of measuring the external shape. In this case, even if the light emission characteristics of the light emitting device intermediate are not measured, it is assumed that all of the light emitting device intermediates in the lot are brighter than expected due to the thick covering member. Furthermore, if it is known from past performance how much the brightness changes due to the difference in thickness, it is also assumed how bright it is. In such a case, the first laser light can be irradiated under the same conditions for all of the light emitting device intermediates in the lot without inspecting the light emission characteristics.

[0062] (Embodiment 2) 7A to 7C are schematic diagrams showing a light emitting device 500 according to embodiment 2. The light emitting device 500 differs from embodiment 1 in that a covering member 530 is disposed on the side surface of the semiconductor laminate of the light emitting element 110. Furthermore, the light emitting device 500 differs from embodiment 1 in that the side surface of the light-transmitting member 520 is also covered with the covering member 530. The other configurations are the same as those of embodiment 1.

[0063] Further, here, a light emitting device 500 including a plurality of light emitting elements 110 is illustrated, specifically, nine light emitting elements 110 arranged in a matrix of three rows and three columns. A light transmissive member 520 is arranged on each light emitting element 110. A part or all of the plurality of light emitting elements 110 can be simultaneously lit. The light emitting element 110 and the light transmissive member 520 arranged thereon are collectively referred to as one light emitting section. That is, the light emitting device 500 shown in FIG. 7A includes nine light emitting sections. The number of light emitting sections is not limited to this and can be selected arbitrarily. Moreover, the materials of the covering member 530 and the light transmissive member 520 are the same as those of the first embodiment.

[0064] In this embodiment, the light-transmitting member 520 is disposed on the upper surface of the light-emitting element 110. The light-transmitting member 520 has an area larger than the area of ​​the upper surface of the light-emitting element 110 in a plan view, and preferably covers the entire upper surface of the light-emitting element 110. The side surface of the light-transmitting member 520 is covered with a covering member 530. In addition, a part of the lower surface of the light-transmitting member 520 is also covered with the covering member 530. A light-transmitting joining member may be provided between the light-transmitting member 520 and the light-emitting element 110.

[0065] The covering member 530 covers the side surface of the semiconductor laminate of the light emitting element 110. A light-transmitting bonding member may be provided between the side surface of the semiconductor laminate of the light emitting element and the covering member 530. The covering member 530 covers the side surface of the light-transmitting member 520. The covering member 530 integrally holds a plurality of light emitting units (light emitting elements 110 and light-transmitting members 520).

[0066] Here, a case where it is desired to make the light emitting device 500 such that all nine light emitting parts have the same brightness will be taken as an example. As a result of measuring the light emitting characteristics of each light emitting part in an inspection device, there may be a variation in brightness, such as light emitting part A being slightly brighter than the other light emitting parts and light emitting part B being even brighter than light emitting part A. In such a case, as shown in FIG. 7C, the first laser light is irradiated to the covering members 530 located at the light emitting parts A and B, respectively, to form the second covering member 532. In the light emitting part A, the second covering member 532 is arranged only in the region between the metal films 140 that cover the electrodes of the light emitting element 110. In the light emitting part B, the second covering member 532 is arranged not only between the metal films 140 but also in the region located outside the metal films 140. In this way, by arranging the appropriate second covering member 532 according to the light emitting characteristics, it is possible to reduce the situation where only some light emitting parts become too bright, and reduce the variation between the light emitting parts.

[0067] For example, aspects of the present invention are as follows.

[0068] (Appendix 1) a light emitting element including a semiconductor laminate including an upper surface, a lower surface opposite to the upper surface, and a side surface between the upper surface and the lower surface, and a pair of electrodes disposed on the lower surface; a light-transmitting member covering the upper surface of the semiconductor laminate; a covering member that continuously covers a lower surface of the semiconductor laminate and a lower surface of the light-transmitting member and exposes a portion of the pair of electrodes; Equipped with The light emitting device, wherein the covering member comprises a light reflective first covering member in contact with the semiconductor laminate and the light-transmitting member, and a light absorbing second covering member arranged via the first covering member in a position overlapping the semiconductor laminate in a planar view. (Appendix 2) 2. The light emitting device according to claim 1, wherein the light-transmitting member covers a side surface of the semiconductor laminate. (Appendix 3) 2. The light emitting device according to claim 1, wherein the covering member covers a side surface of the semiconductor laminate. (Appendix 4) 4. The light emitting device according to claim 1, wherein the second covering member is disposed only in a region located between the pair of electrodes in a plan view. (Appendix 5) 5. The light emitting device according to claim 1, wherein the second covering member is not disposed at a position where it does not overlap with the light emitting element in a plan view. (Appendix 6) 6. The light emitting device according to claim 1, wherein the second covering member has a thickness of 3 μm or more and 10 μm or less. (Appendix 7) 7. The light emitting device according to claim 1, wherein the coating member contains titanium oxide or zinc oxide. (Appendix 8) a light emitting element including a semiconductor laminate including an upper surface, a lower surface opposite to the upper surface, and a side surface between the upper surface and the lower surface, and a pair of electrodes disposed on the lower surface; a light-transmitting member covering the upper surface of the semiconductor laminate; a light-reflective covering member that continuously covers a lower surface of the semiconductor laminate and a lower surface of the light-transmitting member and exposes a portion of the pair of electrodes; A first step of preparing an intermediate light emitting device comprising: a second step of irradiating the covering member located between the pair of electrodes with laser light to cause a change in the properties of the covering member. [Explanation of symbols]

[0069] 100, 200, 300, 500...Light emitting device 100A, 300A...Light emitting device intermediate 110...Light emitting element 111...Semiconductor laminate 111U…Top surface 111D…Bottom surface 111S…Side 112...Electrode 120, 520...Translucent member 130, 530...Covering member 131, 531...first covering member 132, 532...Second covering member 140...Metal film 150...Light adjustment material M…Mark L1…First laser light source (first laser light B1) L2: Second laser light source (second laser light B2) L3: Third laser light source (third laser light B3)

Claims

1. a light emitting element including a semiconductor laminate including an upper surface, a lower surface opposite to the upper surface, and a side surface between the upper surface and the lower surface, and a pair of electrodes disposed on the lower surface; a light-transmitting member covering the upper surface of the semiconductor laminate; a covering member that continuously covers a lower surface of the semiconductor laminate and a lower surface of the light-transmitting member and exposes a portion of the pair of electrodes; Equipped with A light emitting device, wherein the covering member comprises: a light reflective first covering member that contacts the semiconductor laminate and the light-transmitting member; and a light absorbing second covering member that is arranged via the first covering member in a position that overlaps the semiconductor laminate in a planar view.

2. The light emitting device according to claim 1 , wherein the light-transmitting member covers a side surface of the semiconductor laminate.

3. The light emitting device according to claim 1 , wherein the covering member covers a side surface of the semiconductor laminate.

4. The light emitting device according to claim 2 , wherein the second covering member is disposed only in a region located between the pair of electrodes in a plan view.

5. The light emitting device according to claim 1 , wherein the second covering member is not disposed at a position where it does not overlap the light emitting element in a plan view.

6. The light emitting device according to claim 2 , wherein the second covering member has a thickness of not less than 3 μm and not more than 10 μm.

7. The light emitting device according to claim 2 , wherein the coating member contains titanium oxide or zinc oxide.

8. a light emitting element including a semiconductor laminate including an upper surface, a lower surface opposite to the upper surface, and a side surface between the upper surface and the lower surface, and a pair of electrodes disposed on the lower surface; a light-transmitting member covering the upper surface of the semiconductor laminate; a light-reflective covering member that continuously covers a lower surface of the semiconductor laminate and a lower surface of the light-transmitting member and exposes a portion of the pair of electrodes; A first step of preparing an intermediate light emitting device comprising: a second step of irradiating the covering member located between the pair of electrodes with laser light to cause a change in the properties of the covering member.

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