JP7769239B2 - Light-emitting device - Google Patents

Description

This disclosure relates to a light-emitting device.

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

Japanese Patent Application Laid-Open No. 2007-173849

An embodiment of the present disclosure aims to provide a light-emitting device with reduced brightness unevenness.

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
a light-emitting device, wherein the covering member comprises a light-reflective first covering member that contacts the semiconductor laminate and the translucent 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.

Embodiments of the present disclosure can provide a light-emitting device with reduced brightness unevenness.

1 is a schematic perspective view of a light emitting device according to an embodiment of the present disclosure. FIG. 2 is a schematic bottom view of the light emitting device according to the embodiment of the present disclosure. FIG. 1C is a schematic cross-sectional view taken along line IC-IC shown in FIG. 1B. FIG. 10 is a schematic cross-sectional view of a modified example of the light emitting device according to the embodiment of the present disclosure. 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. 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. FIG. 10 is a schematic cross-sectional view of a modified example of the light emitting device according to the embodiment of the present disclosure. FIG. 10 is a schematic cross-sectional view of a modified example of the light emitting device according to the embodiment of the present disclosure. 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. 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. FIG. 10 is a schematic bottom view of a modified example of the light emitting device according to the embodiment of the present disclosure. FIG. 6B is a schematic cross-sectional view taken along line VIB-VIB shown in FIG. 6A. 1 is a schematic top view of a light emitting device according to an embodiment of the present disclosure. FIG. 7B is a schematic cross-sectional view taken along line VIIB-VIIB shown in FIG. 7A. FIG. 2 is a schematic bottom view of the light emitting device according to the embodiment of the present disclosure.

The following describes in detail the embodiments of the present invention with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "up," "down," "right," "left," and other terms incorporating these terms) are used as necessary. The use of these terms is intended to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. A plan view refers to a view from the top or bottom. Parts with the same reference numerals appearing in multiple drawings indicate the same part or component. Resin components such as coatings will be described using the same name regardless of whether they are molded, solidified, cured, or singulated. In other words, components whose state changes depending on the process stage, such as when they are liquid before molding, solidify after molding, and then divided into small, shape-changing solid pieces, will be described using the same name.

The light-emitting device according to the embodiment comprises a semiconductor laminate having an upper surface, a lower surface opposite the upper surface, and side surfaces between the upper and lower surfaces; a light-emitting element having 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 comprises 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.

(Embodiment 1)
<Light-emitting device>
1A to 1C are schematic diagrams illustrating a light-emitting device 100 according to a 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 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 comprises 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.

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, thereby reducing brightness unevenness.
Each component will be described in detail below.

(Light-emitting element)
The light-emitting device 100 includes at least one light-emitting element 110. The light-emitting element 110 can be, for example, a semiconductor light-emitting element such as a light-emitting diode. 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 a planar 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 to 3000 μm in a planar view. Specifically, the size can be a square with sides of approximately 600 μm, 1400 μm, or 1700 μm. Alternatively, the light-emitting element 110 can be a rectangle having long and short sides in a planar view. For example, the size can be 1100 μm x 200 μm.

The semiconductor stack 111 includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting layer sandwiched between them. The semiconductor stack including such a light emitting layer may include, for example, In _x Al _y Ga _1-x-y N (0≦x, 0≦y, x+y≦1).

The semiconductor stack 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 that order is repeated multiple times. When the semiconductor stack 111 includes multiple light-emitting layers, the light-emitting layers may have different emission peak wavelengths, or may have light-emitting layers with the same emission peak wavelength. Note that the same emission peak wavelength includes cases where there is a variation of about several nanometers. The combination of emission peak wavelengths between the multiple light-emitting layers can be selected appropriately. For example, when the semiconductor stack 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.

The light-emitting element 110 has a pair of positive and negative electrodes 112 on the lower surface 111D of the semiconductor laminate 111. The electrodes 112 can be made of a good electrical conductor, such as gold, silver, tin, platinum, rhodium, titanium, aluminum, tungsten, palladium, nickel, or an alloy of these. The electrodes 112 can 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 externally. The thickness of the electrodes can be, for example, 10 μm or more and 50 μm or less.

(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 stack 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 other figures, 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 preferred, and thermosetting resins such as silicone resin, silicone-modified resin, epoxy resin, and phenolic resin, and thermoplastic resins such as polycarbonate resin, acrylic resin, methylpentene resin, and polynorbornene resin can be used. In particular, silicone resin, which has excellent light resistance and heat resistance, is preferred. The light-transmitting member 120 may be made of only such a light-transmitting member, or may be made of such a light-transmitting member as a base material and contain a phosphor that is excited by light from the light-emitting element and converts it into light of a different wavelength, a light scattering agent, or the like.

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 or α-sialon phosphors, nitride phosphors such as LSN phosphors, BSESN phosphors, SLA phosphors, CASN phosphors or SCASN phosphors, fluoride phosphors such as KSF phosphors, KSAF phosphors or MGF phosphors, quantum dots with a perovskite structure, II-VI quantum dots, III-V quantum dots, and quantum dots with a chalcopyrite structure.

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.

(Covering member)
The covering member 130 is a member that continuously covers the lower surface 111D of the semiconductor stack 111 of the light-emitting element 110 and the lower surface of the translucent member 120. The covering member 130 also covers the side surfaces of the electrodes 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 stack 111 of the light-emitting element 110 and the translucent member 120. The second covering member 132 is disposed at a position where it overlaps the semiconductor stack 111 of the light-emitting element 110 in a plan view, with the first covering member 131 interposed therebetween. In other words, the covering member 130 located below the lower surface 111D of the semiconductor stack 111 has a structure in which the first covering member 131 and the second covering member 132 are stacked.

The first coating member 131 and the second coating member 132 were originally the same member. The part of this member that was irradiated with laser light and altered is the second coating member 132, while the part that was not irradiated with laser light and remained unchanged is the first coating member 131.

The covering member 130 includes a base material and particles contained in the base material. The aforementioned "alteration" includes altering the particles. For example, it includes altering first particles to form second particles. One method of alteration is to irradiate the first particles with laser light (first laser light, described below). This allows the body color of the first particles, which appear white, to be altered to second particles, which appear 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 both the second particles and the first particles.

The base material for the covering member 130 can be a thermosetting resin such as silicone resin, silicone-modified resin, epoxy resin, or phenolic resin, or a thermoplastic resin such as polycarbonate resin, acrylic resin, methylpentene resin, or polynorbornene resin. Silicone resin is particularly suitable, as it has excellent light resistance and heat resistance.

Examples of the first particles include titanium oxide and zinc oxide. The second particles are altered versions of these, such as altered titanium oxide and altered zinc oxide.

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. One method of alteration is to irradiate the first base material with a laser. This can change the body color of the first base material, which appears translucent, to a second base material, which appears black.

As mentioned 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 placing such an altered member directly below the semiconductor stack 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.

When the covering member 130 is altered by laser irradiation, its color changes primarily as described above, and its surface roughness increases slightly. In other words, it is believed that a portion of the covering member 130 is removed by the laser light irradiation. However, when the laser light is irradiated in a line, no linear grooves are formed; instead, fine irregularities are formed across 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.

The first covering member 131 has a reflectance of 70% or more for light at the peak emission 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 peak emission wavelength of light emitted from the light-emitting element 110.

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.

The second covering member 132 may have the same thickness throughout, or may have portions of varying thickness. Furthermore, the second covering member 132 may be thickest at the center in a plan view, and become thinner as it approaches the periphery. This allows the light absorption rate of the second covering member 132 to be gradually varied. Such portions with different light absorption rates can be obtained, for example, by controlling the irradiation conditions of the first laser beam B1 to control the ratio at which the first particles are transformed into second particles. Note that if the output of the first laser beam B1 is too high, the covering member 130 will be ablated. Therefore, if you want to increase the light absorption rate, that is, if you want to increase the ratio of second particles, it is preferable to increase the number of times the first laser beam B1 is irradiated within the output range described below.

The second covering member 132 can have an area of 1% to 50% of the area of the portion overlapping with the semiconductor laminate 111 in a planar 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 planar view. For example, the second covering member 132 can occupy 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 directly below the semiconductor laminate 111, in a position where it is most likely to be irradiated with light from the light emitting element 110, light can be absorbed efficiently.

It is preferable that the second covering member 132 is not positioned so as to overlap the light emitting element 110 in a planar view. This reduces the interference of light propagating within the light-transmitting member 120 with reflection by the first covering member 131. This reduces the reduction in brightness in the area directly above the light emitting element 110. In particular, when the width of the light-transmitting member 120 located to the side of the light emitting element 110 is wide, i.e., when the distance from the light emitting element 110 to the side surface (outer surface) of the light-transmitting member 120 is long, efficient reflection by the first covering member 131 can facilitate light propagation to the outer surface.

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

The light-emitting device may include a light-adjusting member above the light-emitting element. The light-emitting device 200 shown in FIG. 2 has a light-adjusting member 150 disposed on the upper surface of a translucent member 120 that covers the light-emitting element 110. The light-adjusting member 150 is capable of adjusting the amount and direction of light emitted from the upper surface of the translucent member 120. The light-adjusting member 150 is reflective and translucent with respect to the light emitted from the light-emitting element 110. A portion of the light emitted from the upper surface of the translucent member 120 is reflected by the light-adjusting member 150, while another portion is transmitted through the light-adjusting member 150. The transmittance of the light-adjusting member 150 for the light emitted from the light-emitting element 110 is preferably, for example, 1% to 50%, and more preferably 3% to 30%. The light-adjusting member 150 may be made of the same material as the covering member 130. By providing such a light adjustment member 150, the light emitted from the light emitting element 110 is reflected back toward the light emitting element 110, making it more likely to be absorbed by the second covering member 132.

<Method of manufacturing a light-emitting device>
The light-emitting device 100 shown in Figure 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 it to change in quality.

In detail, the method for manufacturing a 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 disposed on the lower surface, a translucent 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 translucent member and exposes portions of the pair of electrodes, and a second step of irradiating the covering member located between the pair of electrodes with laser light to modify it.

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 that includes portions that will become multiple light-emitting devices 100. When using such a light-emitting device intermediate 100A, a step of cutting along cutting line C shown in FIG. 3B can be included before or after irradiation with the first laser light B1. However, a light-emitting device intermediate 100A that will become a single light-emitting device 100 may also be used.

As shown in FIG. 3A, the light-emitting device intermediate 100A is positioned so that the covering member 130 faces upward. The first laser light source L1 is positioned above the light-emitting device intermediate 100A. However, this is not a limitation, as long as the covering member 130 and the first laser light source L1 are positioned opposite each other. The first laser light source L1 moves laterally at a fixed distance from the surface of the light-emitting device intermediate 100A facing upward. 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 third laser light source L3 described below.

The first laser light B1 is emitted under conditions that allow for alteration of the covering member 130 in the irradiated portion. The dominant wavelength, output (intensity), diameter of the irradiation spot, and movement speed of the irradiation spot of the first laser light B1 can be set in consideration of the amount of light desired to be absorbed by the second covering member 132, depending on the material of the covering member 130 and the intensity of the light emitted from the light-emitting element 110.

For example, consider a case where the coating member 130 is made of a resin material containing silicone and titanium oxide. In this case, it is preferable to use a first laser light source L1 capable of emitting green laser light having a dominant 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 more preferably approximately 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 movement 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 first laser light B1 include second harmonics of YAG lasers, _YVO4 lasers, etc.

A measurement process can be provided in which the light-emitting characteristics of the light-emitting device intermediate 100A are measured before the first laser light B1 is irradiated. This allows the conditions for the first laser light B1 to be set according to the light-emitting characteristics of each individual light-emitting device intermediate 100A.

(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 portion of the lower surface of the covering member 130.

The metal film 140 can function primarily as a protective film to reduce corrosion and oxidation of the electrode 112. A material that is more corrosion-resistant and oxidation-resistant than the electrode 112 is selected 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. Furthermore, if the light-emitting device 200 is to be 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.

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 metal film 140 with a stacked structure include a structure in which gold is placed on the outermost surface, such as nickel/ruthenium/gold or titanium/platinum/gold. Alternatively, the outermost surface may be gold, and the ruthenium or other material placed underneath functions as a diffusion prevention layer that prevents the material that makes up the electrode from diffusing into the gold. The thickness of such a diffusion prevention layer is preferably between 10 Å and 1000 Å.

The thickness of the metal film 140 is preferably, for example, 1 μm or less, and more preferably 1000 Å or less. Furthermore, a thickness of, for example, 5 nm or more is preferable to reduce corrosion of the electrode 112. Here, the thickness of the metal film refers to the total thickness of the multiple layers when the metal film is composed of multiple stacked layers.

In addition, a light-emitting device can be provided that includes both the metal film 140 and the light adjustment member 150 described above.

In the case of a light-emitting device having a metal film 140, the light-emitting device intermediate prepared in the second step described above is a light-emitting device intermediate 300A having a metal film 140 that continuously covers the electrode 112 of the light-emitting element 110 and the covering member 130. Then, prior to the second step described above, a step is provided in which the entire surface or part of the metal film 140 is irradiated with second laser light B2 to remove all or part of the metal film 140 covering the covering member 130 by ablation.

As shown in FIG. 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, atomic layer deposition (ALD), metal organic chemical vapor deposition (MOCVD), plasma-enhanced chemical vapor deposition (PECVD), atmospheric pressure plasma deposition, plating, or the like.

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 dominant wavelength, output (intensity), diameter of the irradiation spot, and movement speed of the irradiation spot of the second laser light B2 can be set taking into consideration the material of the covering member 130 and the material of the electrode 112. The second laser light B2 can be irradiated onto 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 unremoved even when irradiated with the second laser light B2.

A portion of the covering member 130 is removed in the area irradiated with the second laser beam B2. For example, when the second laser beam B2 is irradiated in multiple lines across the entire surface of the metal film 140, multiple linear grooves are formed. The groove width is approximately 10 μm to 100 μm, and the groove depth is approximately 0.1 μm to 3 μm. It is believed that such grooves form because the covering member 130 is also removed when the metal film 140 is ablated. Furthermore, the covering member 130 with such grooves formed is not altered, as occurs when the first laser beam B1 is irradiated. If the covering member is made of a resin material containing titanium oxide and a silicone base material, the covering member 130 appears white before being irradiated with the second laser beam B2, and the covering member 130 appears white after being irradiated with the second laser beam B2.

For example, consider a case where the coating member 130 is made of a resin material containing titanium oxide and a silicone base material. In this case, it is preferable to use a second laser light source L2 capable of emitting green laser light with a dominant 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 quantity 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, for example, second harmonics.

In this way, by first forming the metal film 140 that protects the electrode 112, it is possible to reduce deterioration of the electrode 112 when measuring the luminescence characteristics.

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

The third laser light is irradiated onto the covering member 130 under conditions that remove a portion of the covering member 130 and allow for the 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, and movement speed of the irradiation spot 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 that have been determined to be defective through inspection.

In the area of the covering member 130 irradiated with the third laser beam B3, not only is the covering member 130 altered in the same manner as in the area irradiated with the first laser beam B1, but also the covering member 130 is removed to a depth of approximately 6 μm or more, forming a recess. For example, the recognition device used in the recognition process may be prone to false recognition due to color differences or minute irregularities. Therefore, removing the recess to a certain depth allows for correct recognition. Therefore, in a light-emitting device 100 having the structure shown in FIG. 1A, irradiating the portion overlapping the light-emitting element 110 with the third laser beam B3 may affect the light-emitting element 110. Therefore, it is preferable to irradiate the third laser beam B3 at a position that does not overlap the light-emitting element 110 in a planar view. A bad mark indicating a defective product can be formed in a large, conspicuous position to prevent the light-emitting device bearing the mark from being sold. The third laser beam B3 can be irradiated either before or after the first laser beam B1.

For example, consider a case where the coating member 130 is made of a resin material containing silicone and titanium oxide. In this case, a green laser beam having a dominant wavelength of 532 nm can be used as the third laser beam. The output of the third laser beam is preferably 1 W or more and 4 W or less, and preferably, a laser beam with an output of approximately 2 W is irradiated. The third laser beam may be continuous wave or pulsed. For example, in the case of pulsed oscillation, the heat amount per pulse of the third laser beam B3 can be 30 μJ or more and 35 μJ or less. The diameter of the irradiation spot of the third laser beam 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 beam include second harmonics of YAG lasers, _YVO4 lasers, etc.

As described above, when three types of laser light with different conditions are irradiated, the irradiation can be carried out in the following four orders.
(1) Irradiation of the second laser light, the first laser light, and the third laser light in this order. (2) Irradiation of the second laser light, the third laser light, and the first laser light in this order. (3) Irradiation of the third laser light, the first laser light, and the second laser light in this order. (4) Irradiation of the third laser light, the second laser light, and the first laser light in this order.

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. The light-emitting device intermediate is then removed from the laser irradiation device to measure its light-emitting characteristics. The light-emitting characteristics are measured using an inspection device, and the conditions for the first laser light are determined based on the light-emitting characteristics. Next, the light-emitting device intermediate is placed again in the laser irradiation device, and the first laser light is irradiated to the necessary portions to form a second coating member. The same laser irradiation device then irradiates the third laser light to form a lot mark or serial number. Because the conditions for the third laser light can be set independently of the light-emitting characteristics, the third laser light can be irradiated without removing the device from the laser irradiation device after irradiating the first laser light. This allows for efficient manufacturing of light-emitting devices. Alternatively, after irradiating the first laser light, the light-emitting device intermediate can be removed from the laser irradiation device and its light-emitting characteristics measured again using an inspection device. This allows for measurement of the light-emitting characteristics with the second coating member formed. The light-emitting device intermediate is then placed again in the laser irradiation device, and, if necessary, irradiated with the third laser light to form a bad mark.

When irradiating in the order (2), the order of irradiation of the first laser light and the third laser light is reversed compared to when irradiating in the order (1), and it is the same as (1) in that the first laser light and the third laser light can be irradiated without removing the device from the laser irradiation device. Here, the light-emitting characteristics of the light-emitting device intermediate are measured in an inspection device before irradiating the first laser light, and then the third laser light is irradiated to form a serial number or bad mark. At this time, deep recesses are formed, causing debris to form on the surface of the coating member. While there may be no problem if the debris is left as is, it is also possible to remove the debris while forming a second coating member when irradiating the first laser light thereafter.

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

When irradiating in the order of (4), the order of irradiation of the first laser light and the second laser light is reversed compared to when irradiating in the order of (3). This is the same as (3) in that the light-emitting characteristics of the intermediate light-emitting device are first 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 second laser light is irradiated to form a metal film.

In the above (1) to (4), the first laser light may be irradiated without inspecting the light-emitting characteristics. For example, consider a case where measurement of the external dimensions reveals that the thickness of the covering material of the light-emitting device intermediates in that lot is thicker than expected. In this case, even without measuring the light-emitting characteristics of the light-emitting device intermediates, it is assumed that all of the light-emitting device intermediates in that lot will be brighter than expected due to the thick covering material. Furthermore, if it is known from past performance how much brightness changes due to differences in thickness, the brightness level can also be estimated. In such a case, the first laser light can be irradiated under the same conditions for all of the light-emitting device intermediates in that lot without inspecting the light-emitting characteristics.

(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, it 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.

The light emitting device 500 shown here includes a plurality of light emitting elements 110, specifically nine light emitting elements 110 arranged in a matrix of three rows and three columns. A translucent member 520 is disposed above each light emitting element 110. Some or all of the plurality of light emitting elements 110 can be illuminated simultaneously. The light emitting element 110 and the translucent member 520 disposed thereon are collectively referred to as one light emitting unit. In other words, the light emitting device 500 shown in Figure 7A includes nine light emitting units. The number of light emitting units is not limited to this and can be selected arbitrarily. The materials of the covering member 530 and the translucent member 520 are the same as those in embodiment 1.

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 surfaces of the light-transmitting member 520 are covered with the covering member 530. In addition, a portion 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.

The covering member 530 covers the side surface of the semiconductor laminate of the light-emitting element 110. A translucent 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 translucent member 520. The covering member 530 integrally holds multiple light-emitting units (light-emitting elements 110 and translucent members 520).

Here, let's take an example where we want to create a light-emitting device 500 in which all nine light-emitting elements have the same brightness. Measuring the light-emitting characteristics of each light-emitting element using an inspection device may reveal variations in brightness, such as light-emitting element A being slightly brighter than the other light-emitting elements and light-emitting element B being even brighter than light-emitting element A. In such a case, as shown in Figure 7C, the first laser light is irradiated onto the covering members 530 located at light-emitting element A and light-emitting element B, respectively, to form second covering members 532. In light-emitting element A, the second covering members 532 are arranged only in the areas between the metal films 140 that cover the electrodes of the light-emitting element 110. In light-emitting element B, the second covering members 532 are arranged not only between the metal films 140 but also in areas located outside the metal films 140. In this way, by placing an appropriate second covering member 532 according to the light-emitting characteristics, it is possible to prevent some light-emitting elements from becoming too bright and reduce variations between the light-emitting elements.

Examples of the present invention are as follows:

(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
a light-emitting device, wherein the covering member comprises a light-reflective first covering member that contacts the semiconductor laminate and the translucent 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.
(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 positioned so as to overlap 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.

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 surface 112... Electrode 120, 520... Light-transmitting member 130, 530... Covering member 131, 531... First covering member 132, 532... Second covering member 140... Metal film 150... Light adjustment member 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 (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 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 translucent 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. The light-emitting device of claim 1, wherein the translucent member covers the side surfaces of the semiconductor laminate. The light-emitting device of claim 1, wherein the covering member covers the side surfaces of the semiconductor laminate. The light-emitting device described in claim 2 or claim 3, wherein the second covering member is disposed only in an area located between the pair of electrodes in a plan view. The light-emitting device described in claim 1 or claim 3, wherein the second covering member is not positioned so as to overlap the light-emitting element in a plan view. The light-emitting device described in claim 2 or claim 3, wherein the thickness of the second covering member is 3 μm or more and 10 μm or less. The light-emitting device described in claim 2 or claim 3, wherein the coating member contains titanium oxide or zinc oxide. 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.