Light-emitting device

Abstract

To provide a light-emitting device capable of reducing heat damage to a light-emitting element and further capable of fixing a first mounting component in an arbitrary direction.SOLUTION: A light-emitting device includes a substrate having an upper surface provided with one or more recesses or protrusions, and one or more first mounting components fixed to the substrate and having a lower surface provided with the other of the recess and the protrusion, and the first mounting component includes a light emitting element, the recess is fitted with the protrusion, and both the recess and the protrusion have a circular outer edge shape when viewed from above.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 describes a method for manufacturing a laser package having a submount, an edge-emitting laser element mounted on the submount, an optical member, and a substrate. In Patent Document 1, the submount and the optical member are bonded to the substrate using a bonding material containing metal nanoparticles or metal submicron particles and an organic solvent.

[0003] Patent Document 2 describes a submount with a V-groove formed on its back surface and a heat sink with protrusions formed to fit tightly into the V-groove. A solder material is used to fix the submount and heat sink in Patent Document 2. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-107319 [Patent Document 2] Japanese Patent Application Publication No. 57-007989 Summary of the Invention [Problem to be solved by the invention]

[0005] Solder and other bonding materials are used to bond components together by heating and then cooling them. If this heating process could be eliminated, thermal damage to light-emitting elements such as laser elements could be reduced. [Means for solving the problem]

[0006] A light-emitting device according to one embodiment of the present invention comprises a substrate having an upper surface on which one or more recesses or protrusions are provided, and one or more first mounting components fixed to the substrate and having a lower surface on which one of the other of the recesses or protrusions is provided, wherein the first mounting components have a light-emitting element, the recesses are fitted with the protrusions, and both the recesses and the protrusions have a circular outer edge shape when viewed from above.

[0007] Another embodiment of the light emitting device of the present invention comprises a base having an upper surface on which one or more recesses or protrusions are provided, a first mounting component fixed to the base and having a laser element that emits laser light, and one or more second mounting components fixed to the base and having a lower surface on which one of the other of the recesses or protrusions is provided, wherein the second mounting components have a light reflecting surface that reflects the laser light from the laser element, the recesses are fitted with the protrusions, and both the recesses and the protrusions have a circular outer edge shape when viewed from above. [Effects of the Invention]

[0008] According to the light emitting device described above, it is possible to reduce thermal damage to the light emitting element, and furthermore, the first mounted component or the second mounted component can be fixed in any orientation. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic perspective view of the first mounting component. [Figure 3] FIG. 3 is a schematic top view of the light emitting device. [Figure 4] FIG. 4 is a schematic top view showing the light emitting device with the lid removed. DETAILED DESCRIPTION OF THE INVENTION

[0010] Fig. 1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. Fig. 2 is a schematic perspective view of a first mounting component. Fig. 3 is a schematic top view of the light emitting device. Fig. 4 is a schematic top view of the light emitting device with a lid removed.

[0011] As shown in FIGS. 1 and 2, the light emitting device 1 has a base material 10 and one or more first mounting components 20. The base material 10 has an upper surface on which one or more recesses or protrusions are provided. The first mounting components 20 are fixed to the base material 10 and have a lower surface on which one of the other of the recesses or protrusions is provided. The first mounting components 20 have a light emitting element 21. In this embodiment, a protrusion 11 is provided on the upper surface of the base material 10, and a recess 22 is provided on the lower surface of the first mounting components 20. A recess may be provided on the upper surface of the base material 10, and a protrusion may be provided on the lower surface of the first mounting components 20. The recess 22 is fitted into the protrusion 11. The recess 22 and the protrusion 11 both have a circular outer edge shape when viewed from above.

[0012] In the light emitting device 1, the base material 10 and the first mounting component 20 can be fixed by fitting the recess 22 and the protrusion 11 together. This allows the base material 10 and the first mounting component 20 to be fixed without using an adhesive, which reduces thermal damage to the light emitting element 21 compared to when an adhesive is used for fixing. In addition, because the outer edges of the recess 22 and the protrusion 11 are circular in top view, the first mounting component 20 can be fixed in any orientation.

[0013] Each component will be described below in order.

[0014] (Light-emitting device 1) As shown in Figures 3 and 4, the light emitting device 1 may have components other than the base material 10 and the first mounting component 20. The light emitting device 1 has a frame 30, an anode terminal 41, a cathode terminal 42, and a lid 80. The light emitting device 1 has a second mounting component 50. The light emitting device 1 has a conductive wire 60. The light emitting device 1 has a relay member 70. The first mounting component 20 is disposed in a sealed space surrounded by the base material 10, the frame 30, and the lid 80. The sealed space is, for example, a hermetically sealed space.

[0015] (Base material 10) The substrate 10 is a member on which the first mounting component 20 can be mounted. The top surface of the substrate 10 has a protrusion 11 and a flat portion surrounding the protrusion 11. The bottom surface of the substrate 10 is thermally connected to a heat sink or the like and can be used as a heat dissipation surface for dissipating heat from the light emitting element 21. The top surface of the substrate 10 refers to the surface on which the first mounting component 20 is mounted, and the bottom surface refers to the surface opposite thereto.

[0016] The substrate 10 can be made of a ceramic material or a metal material. Examples of metal materials include iron, iron alloys, copper, and copper alloys. It is preferable that at least the protrusions 11 of the substrate 10 are made primarily of copper or a copper alloy, which has the advantage of making it easier to fit into the recesses of the first mounting component 20. The protrusions 11 may be made of a main portion made solely of copper or a copper alloy and a surface layer formed on the surface of the main portion. Similarly, when a recess is provided in the substrate 10, it is preferable that the portion constituting the recess be made primarily of copper or a copper alloy.

[0017] (Protrusion 11 and recess 22) A protrusion 11 is provided on the upper surface of the substrate 10, and a recess 22 is provided on the lower surface of the first mounting component 20. The recess 22 and the protrusion 11 are fitted together to fix the substrate 10 and the first mounting component 20 together.

[0018] The difference in height between the recess 22 and the protrusion 11 can be 0 μm or more, and preferably exceeds 0 μm. The height (depth) of the recess 22 is preferably greater than the height of the protrusion 11. This allows the portion of the lower surface of the first mounting component 20 surrounding the recess 22 and the portion of the upper surface of the base 10 surrounding the protrusion 11 to be in more reliable contact or proximity. The light-emitting element 21 of the first mounting component 20 generates heat when driven, and this heat can be transferred from the lower surface of the first mounting component 20 to the upper surface of the base 10 and dissipated. The difference in height between the recess 22 and the protrusion 11 can be 20 μm or less.

[0019] The recess 22 has a side and a bottom. The protrusion 11 has a side and a top. It is preferable that the side of the recess 22 and the side of the protrusion 11 are in contact with each other, and that the bottom of the recess 22 and the top of the protrusion 11 are not in contact with each other. This allows the recess 22 and the protrusion 11 to be fitted together, while more reliably bringing the surrounding area of ​​the recess 22 and the surrounding area of ​​the protrusion 11 into contact with each other or close to each other.

[0020] In an unengaged state, the inner diameter of the recess 22 may be smaller than the outer diameter of the protrusion 11. In this case, the difference between the inner diameter of the recess 22 and the outer diameter of the protrusion 11 is preferably 20 μm or less, and more preferably 10 μm or less. This allows the protrusion 11 to be more reliably engaged with the recess 22. The difference between the inner diameter of the recess 22 and the outer diameter of the protrusion 11 may be 5 μm or less. Regarding the size relationship between the inner diameter of the recess 22 and the outer diameter of the protrusion 11, it is preferable to maintain a relationship in which the inner diameter of the recess of the substrate 10 is smaller than the outer diameter of the protrusion of the first mounting component 20, even when a recess is provided on the upper surface of the substrate 10 and a protrusion is provided on the lower surface of the first mounting component 20.

[0021] The distance between the portion of the upper surface of the substrate 10 other than the portion where the protrusion 11 is provided and the portion of the lower surface of the first mounting component 20 other than the portion where the recess 22 is provided is preferably smaller than the distance between the bottom of the recess 22 and the top of the protrusion 11. This allows the recess 22 and the protrusion 11 to be fitted together, while more reliably bringing the portion around the recess 22 and the portion around the protrusion 11 into contact with each other. Even when the portion of the upper surface of the substrate 10 other than the protrusion 11 and the portion of the lower surface of the first mounting component 20 other than the recess 22 are in contact with each other, and the bottom of the recess 22 and the top of the protrusion 11 are not in contact with each other, it can be said that the above-mentioned relationship in terms of distance is satisfied.

[0022] There is no need to provide an adhesive between the base material 10 and the first mounted component 20. If a gap occurs between the base material 10 and the first mounted component 20, in order to fill the gap, thermal grease, a thermal dissipation sheet, a metal spacer, or the like may be provided between the base material 10 and the first mounted component 20. For example, if the light emitting element 21 is a laser element, a metal spacer may be used to prevent dust collection by organic matter.

[0023] The shapes of the recesses 22 and the protrusions 11 are, for example, cylindrical. The shapes of the recesses 22 and the protrusions 11 may be truncated cones or cones. The shapes of the recesses 22 and the protrusions 11 do not have to be the same. For example, the recesses 22 may be cylindrical, and the protrusions 11 may have a tapered tip, in other words, a shape that combines a cylinder and a truncated cone. This makes it easier to fit the recesses 22 and the protrusions 11 together. In this case, it is preferable that the outer diameter of the cylindrical shape of the protrusions 11 and the outer diameter of the base of the truncated cone are equal, and that the inner diameter of the recesses 22 when not fitted together is smaller than them by 20 μm or less. This allows the protrusions 11 to fit into the recesses 22 more reliably.

[0024] A recess may be provided on the upper surface of the substrate 10, and a protrusion may be provided on the lower surface of the first mounting component 20. In this case, unless otherwise specified, the protrusion 11 of the substrate 10 may be read as a recess, and the recess 22 of the first mounting component 20 may be read as a protrusion, and the configuration described above or below may be adopted.

[0025] (First mounting component 20) The first mounting component 20 has a light-emitting element 21. The bottom surface of the first mounting component 20 has a recess 22 and a flat portion surrounding the recess 22. The flat portion can be used as the main heat dissipation surface of the first mounting component 20. For this reason, it is preferable that the area of ​​the flat portion is larger than the area of ​​the recess 22 when viewed from the bottom. By bringing the flat portion of the base material 10 and the flat portion of the first mounting component 20 into contact with or close to each other, heat generated by the light-emitting element 21 can be dissipated to the base material 10.

[0026] In top view, the recess 22 is arranged at a position that includes the center of the first mounting component 20. In other words, when viewed through the recess 22 in top view, the recess 22 is arranged at a position that includes the center of the first mounting component 20. Alternatively, it can be said that the recess 22 has a similar arrangement when viewed from below. This makes it easy to control the center position. In top view, the recess 22 may be arranged at a position that does not include the center of the first mounting component 20.

[0027] The lower surface of the first mounting component 20 may be the lower surface of the light-emitting element 21, or may be the lower surface of a member different from the light-emitting element 21. For example, the first mounting component 20 may have a submount 23, and the lower surface of the submount 23 may be the lower surface of the first mounting component 20. In this case, the recess 22 can be provided in the lower surface of the submount 23, so that the recess 22 can be formed without having to process the light-emitting element 21. The light-emitting element 21 is fixed on the submount 23.

[0028] The light emitting device 1 has one or more first mounting components 20, and may have a plurality of first mounting components 20. In Fig. 4, a plurality of first mounting components 20 are arranged on the substrate 10. The plurality of first mounting components 20 can be arranged, for example, in a matrix.

[0029] (Light emitting element 21) The light-emitting element 21 is an element that emits light, such as a semiconductor light-emitting element. Because the outer edges of the recessed portion 22 and the protruding portion 11 are circular in top view, the orientation of the first mounted component 20 relative to the base 10 can be adjusted according to the distribution and direction of light emitted by the light-emitting element 21. The light-emitting element 21 is preferably a laser element, such as a semiconductor laser element. The orientation of the first mounted component 20 relative to the base 10 can be adjusted according to the emission direction of the laser light emitted by the light-emitting element 21.

[0030] The semiconductor laser element may have an active layer made of a nitride semiconductor. When using such a semiconductor laser element, it is preferable to hermetically seal it because the emitted laser light is likely to cause dust to collect. The nitride semiconductor is Al x In y Ga 1-x-y Examples of suitable semiconductor laser elements include III-V semiconductors such as N (0≦x≦1, 0≦y≦1, 0≦x+y≦1). The semiconductor laser element includes, for example, a semiconductor laminate in which an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are laminated in this order, an n-electrode electrically connected to the n-type semiconductor layer, and a p-electrode electrically connected to the p-type semiconductor layer. Each of the semiconductor laser elements emits laser light. Each laser light is extracted to the outside through the lid 80 directly or via the second mounting component 50 or the like. A phosphor-containing member may be placed on the optical path of the laser light to extract fluorescence excited by the laser light to the outside.

[0031] 4 is a schematic top view showing a state in which a light-emitting element 21 is arranged on a substrate 10. As shown in FIG. 4, the light-emitting element 21 is arranged on the upper surface side of the substrate 10. The light-emitting device 1 has one or more light-emitting elements 21, and may have a plurality of light-emitting elements 21.

[0032] The plurality of light-emitting elements 21 can be electrically connected to one another by conductive wires 60 or the like. The conductive wires 60 can be made of gold, copper, aluminum, or the like. For example, as shown in FIG. 4, the plurality of light-emitting elements 21 arranged in one direction are connected in series using the conductive wires 60. As shown in FIG. 4, a relay member 70 may be provided between the anode terminal 41 and the light-emitting element 21 and / or between the cathode terminal 42 and the light-emitting element 21.

[0033] (Submount 23) The first mounting component 20 can have a submount 23 to which the light emitting element 21 is fixed. The lower surface of the first mounting component 20 is the lower surface of the submount 23. A recess 22 is provided in the lower surface of the submount 23. The recess 22 may be provided in an area of ​​the lower surface of the submount 23 excluding the area directly below the light emitting element 21. The submount 23 can be made of a material having a thermal expansion coefficient between that of the substrate 10 and the light emitting element 21. This can reduce stress caused by temperature changes.

[0034] The submount 23 can have an insulating portion 23b and a lower surface metal layer 23a provided below the insulating portion 23b. The submount 23 may also have an upper surface metal layer 23c provided on the insulating portion 23b. As shown in FIG. 1, the bottom of the recess 22 can be formed by the insulating portion 23b, and the side surfaces of the recess 22 can be formed by the lower surface metal layer 23a. Such a recess 22 can be easily formed by patterning the lower surface metal layer 23a. If the lower surface metal layer 23a is sufficiently thick, the bottom of the recess 22 may also be formed by the lower surface metal layer 23a.

[0035] The insulating portion 23b may be made of a ceramic material such as AlN or SiC. The thickness of the insulating portion 23b may be 100 μm or more. The thickness of the insulating portion 23b may be 300 μm or less. The lower surface metal layer 23a and the upper surface metal layer 23c may contain one or more of gold, copper, titanium, aluminum, etc. The lower surface metal layer 23a and the upper surface metal layer 23c may have a single-layer structure or a multi-layer structure. The thickness of the lower surface metal layer 23a and the upper surface metal layer 23c may be 25 μm or more and may be 40 μm or more. The thickness of the lower surface metal layer 23a may be 100 μm or less and may be 70 μm or less. Because the upper surface metal layer 23c does not have a recess 22, the thickness of the upper surface metal layer 23c may be smaller than that of the lower surface metal layer 23a. Instead of the lower surface metal layer 23a and / or the upper surface metal layer 23c, a heat dissipation layer made of a material other than metal, such as diamond, may be provided.

[0036] (Frame 30) The frame 30 is bonded to the upper surface of the base material 10. The area of ​​the upper surface of the base material 10 that is surrounded by the frame 30 is the area where the first mounting component 20 is mounted. The frame 30 has a plurality of through holes, into which an anode terminal 41 and a cathode terminal 42 are inserted, respectively. The frame 30 is made of, for example, a metal material.

[0037] (anode side terminal 41, cathode side terminal 42) The anode terminal 41 and the cathode terminal 42 are members for electrically connecting the light emitting element 21 to an external power supply or the like. The anode terminal 41 and the cathode terminal 42 are fixed to the frame 30. Alternatively, a plate may be provided that is fixed to the frame 30, and the anode terminal 41 and the cathode terminal 42 may be fixed to the plate.

[0038] (Second mounting component 50) As shown in FIG. 1, the light emitting device 1 may include a second mounting component 50. The second mounting component 50 has a light reflecting surface. In FIG. 1, the light emitting element 21 is a laser element having a side surface from which laser light is emitted. The second mounting component 50 has a light reflecting surface that reflects the laser light from the light emitting element 21. Because the outer edges of the recessed portion 22 and the protruding portion 11 are circular in top view, the first mounting component 20 can be fixed to the base material 10 at a position where the laser light from the light emitting element 21 is irradiated onto the light reflecting surface of the second mounting component 50. In FIG. 1, if the light emitting element 21 is a laser element, the laser light emitted by the light emitting element 21 is indicated by a dashed line.

[0039] The light-reflecting surface may have a reflectance of 80% or more, or even 90% or more, with respect to the laser light emitted by the light-emitting element 21. The light-reflecting surface is inclined with respect to the lower surface of the second mounting component 50. The inclination angle of the light-reflecting surface with respect to the lower surface is, for example, 45 degrees. The second mounting component 50 has, for example, a base including a mounting surface and an inclined surface inclined with respect to the mounting surface, and a light-reflecting film provided on the inclined surface of the base. The surface on which the light-reflecting film is provided is the light-reflecting surface. The base of the second mounting component 50 may be made of glass, synthetic quartz, silicon, sapphire, aluminum, or the like. The light-reflecting film of the second mounting component 50 may be made of a metal film, a dielectric multilayer film, or the like. The light-reflecting surface of the second mounting component 50 is disposed so as to face the side surface of the light-emitting element 21 from which the laser light is emitted.

[0040] The second mounting component 50 and the substrate 10 are fixed to each other via an adhesive, for example. A recess may be provided on the lower surface of the second mounting component 50, and a protrusion may be provided on the upper surface of the substrate 10, with the recess and the protrusion fitting together. The second mounting component 50 may be fixed to the substrate 10 by this fitting.

[0041] The light emitting device 1 may include a substrate 10 having an upper surface on which one or more recesses or protrusions are provided, a first mounting component 20 fixed to the substrate 10 and having a laser element (light emitting element 21) that emits laser light, and one or more second mounting components 50 fixed to the substrate 10 and having a lower surface on which one of the other of the recesses or protrusions is provided. The second mounting component 50 has a light reflecting surface that reflects the laser light from the laser element. The recesses are fitted with the protrusions, and both the recesses and the protrusions have circular outer edges when viewed from above.

[0042] The second mounting component 50 may be fixed to the base material 10 by fitting the recessed portion into the protruding portion. This makes it possible to reduce thermal damage to the light emitting element 21, and furthermore, the second mounting component 50 can be fixed in any orientation.

[0043] Furthermore, when the second mounting component 50 and the substrate 10 are fixed with an adhesive, the first mounting component 20 is positioned far enough away from the second mounting component 50 that the adhesive for the second mounting component 50 does not reach the first mounting component 20 and cover the side surface of the light-emitting element 21 from which the laser light is emitted. However, since no adhesive is required to fix the second mounting component 50 to the substrate 10, the distance between the first mounting component 20 and the second mounting component 50 can be reduced, thereby shortening the optical path length of the laser light from the light-emitting element 21 to the second mounting component 50. This reduces the beam size of the laser light irradiated onto the light-reflecting surface of the second mounting component 50, thereby reducing the light-reflecting surface and enabling the second mounting component 50 to be miniaturized. Furthermore, when the light-emitting device 1 has multiple light-emitting elements 21, the distance between the light-emitting elements 21 can be reduced. This allows the light-emitting device 1 to be miniaturized.

[0044] A recess may be provided on the lower surface of the second mounting component 50, and a protrusion may be provided on the upper surface of the substrate 10. Alternatively, a protrusion may be provided on the lower surface of the second mounting component 50, and a recess may be provided on the upper surface of the substrate 10. The shapes of the recess and protrusion for fixing the second mounting component 50 may be different from the shapes of the recess and protrusion for fixing the first mounting component 20.

[0045] (lid 80) The lid 80 is connected to the frame 30. The lid 80 may be connected to the base material 10. Light from the light-emitting element 21 passes through the lid 80 and is extracted to the outside of the light-emitting device 1. The lid 80 has a light-transmitting member that transmits the light from the light-emitting element 21. The lid 80 may have a frame portion to which the light-transmitting member is fixed.

[0046] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. All forms that can be implemented by a person skilled in the art through appropriate design modifications based on the above-described embodiments of the present invention also fall within the scope of the present invention as long as they include the gist of the present invention. In addition, a person skilled in the art may come up with various modifications and alterations within the scope of the concept of the present invention, and it is understood that these modifications and alterations also fall within the scope of the present invention. [Explanation of symbols]

[0047] 1. Light-emitting device 10 Base material 11 Convex part 20 First mounting part 21 Light-emitting element 22 recess 23 Submount 23a Bottom metal layer 23b Insulation part 23c Top metal layer 30 Frame 41 Anode terminal 42 Cathode terminal 50 Second mounting part 60 Conductive Wire 70 Relay parts 80 Lid

Claims

1. A substrate having an upper surface on which one or more convex portions are provided; one or more first mounting components fixed to the base material and having a lower surface with a recess provided therein; the first mounting component has a light emitting element, The recess is fitted with the protrusion, the recess and the protrusion each have a circular outer edge when viewed from above, the first mounting component has a submount to which the light emitting element is fixed, the lower surface of the first mounting component is the lower surface of the submount, the submount has an insulating portion and a lower metal layer provided below the insulating portion; a bottom of the recess is formed by the insulating portion, a side surface of the recess portion is formed by the lower metal layer;

2. The light emitting device according to claim 1 , wherein the recess is provided in an area of ​​the lower surface of the submount excluding an area directly below the light emitting element.

3. the light-emitting element is a laser element having a side surface from which laser light is emitted, a second mounting component having a light reflecting surface that reflects the laser light from the light emitting element; The light emitting device according to claim 1 .

4. 4. The light emitting device according to claim 1, wherein the height of the recessed portion is greater than the height of the protruding portion.

5. The recess has a side and a bottom, The protrusion has a side portion and a top portion, the side of the recess and the side of the protrusion are in contact with each other, The light-emitting device according to claim 4 , wherein the bottom of the recess and the top of the protrusion are not in contact with each other.

6. 6. The light-emitting device according to claim 5, wherein the distance between the upper surface of the base material other than the portion where one of the recesses or protrusions is provided and the lower surface of the first mounting component other than the portion where the other of the recesses or protrusions is provided is smaller than the distance between the bottom of the recess and the top of the protrusion.

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