Light emitting device

Abstract

To provide a light-emitting device excellent in heat dissipation.SOLUTION: A light emitting device includes a semiconductor laser element, and a base portion to which a bottom portion made of a metal as a main material and a frame portion made of a ceramic as a main material are bonded, wherein the base portion includes an arrangement surface on which the semiconductor laser element is arranged, a frame surrounding a periphery of the arranged semiconductor laser element, and first and second electrode layers for electrically connecting the semiconductor laser element, the frame portion includes a bonding surface bonded to the placement surface, an inner surface intersecting with the bonding surface and forming a frame larger than the placement surface, and an inner surface intersecting with the bonding surface and forming a frame smaller than the placement surface, and the second electrode layer is provided on a plane intersecting with at least a part of the inner surface forming the frame smaller than the placement surface and different from the bonding surface in the frame portion.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Conventionally, light-emitting element packages have been known in which a light-emitting element such as an LED element or a semiconductor laser element is disposed on the bottom surface of a base having a frame and a bottom surface. Furthermore, several materials can be used for the base, which serves as the package body, one of which is ceramic. Patent Document 1 discloses a light-emitting element package in which a light-emitting element is disposed on a package body whose surface is formed of a ceramic layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2014-68013 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, since light-emitting elements such as semiconductor laser elements generate heat, heat dissipation must also be taken into consideration when creating a package. The light-emitting element package in Patent Document 1 discloses a structure in which the light-emitting element is placed on ceramic, but there is room for improvement in terms of heat dissipation. [Means for solving the problem]

[0005] A light emitting device according to the present invention includes a semiconductor laser element, a bottom portion made mainly of metal, a frame portion made mainly of ceramic to which the bottom portion is joined, and a base portion having a first electrode layer and a second electrode layer electrically connected to the first electrode layer, wherein the bottom portion has an arrangement surface on which the semiconductor laser element is arranged, and the frame portion has an upper surface, a lower surface, a joining surface that is provided below the upper surface and above the lower surface and joins with a part of the arrangement surface, a first inner surface that intersects with the joining surface and extends downward from the joining surface, forming a rectangular first frame that is larger than the arrangement surface, and a second inner surface that intersects with the joining surface. the semiconductor laser element has a second inner side surface that divides the first frame and extends upward from the bonding surface, forming a rectangular second frame that is smaller than the first frame, and a plane that intersects with at least a part of the second inner side surface above the bonding surface, the frame portion has openings that extend from the top surface to the bottom surface of the frame portion, including an opening defined by the first frame and an opening defined by the second frame, the second electrode layer is provided on the plane of the frame portion, the first electrode layer and the second electrode layer are electrically connected to the semiconductor laser element, and the semiconductor laser element is surrounded by the second frame in a top view.

[0006] Furthermore, a light emitting device according to the present invention includes a semiconductor laser element, a bottom portion having an arrangement surface on which the semiconductor laser element is arranged, a frame portion to which the bottom portion is bonded, a first electrode layer, and a second electrode layer electrically connected to the first electrode layer, wherein the bottom portion has a higher thermal conductivity than the frame portion, and the frame portion has an upper surface, a lower surface, a bonding surface that is provided below the upper surface and above the lower surface and bonds to a part of the arrangement surface, a first inner surface that intersects with the bonding surface and extends downward from the bonding surface, forming a rectangular first frame that is larger than the arrangement surface, and a second inner surface that intersects with the bonding surface and extends downward from the bonding surface the semiconductor laser element has a second inner side surface that divides the first frame and extends upward from the bonding surface, forming a rectangular second frame that is smaller than the first frame, and a plane that intersects with at least a part of the second inner side surface above the bonding surface, the frame portion has openings that extend from the top surface to the bottom surface of the frame portion, including an opening defined by the first frame and an opening defined by the second frame, the second electrode layer is provided on the plane of the frame portion, the first electrode layer and the second electrode layer are electrically connected to the semiconductor laser element, and the semiconductor laser element is surrounded by the second frame in a top view.

[0007] Furthermore, a base according to the present invention includes a bottom made mainly of metal, a frame made mainly of ceramic to which the bottom is joined, a first electrode layer, and a second electrode layer electrically connected to the first electrode layer, wherein the bottom has an arrangement surface on which a semiconductor laser element is arranged, and the frame has an upper surface, a lower surface, a joining surface that is provided below the upper surface and above the lower surface and joins with a part of the arrangement surface, a first inner surface that intersects with the joining surface and extends downward from the joining surface, forming a rectangular first frame that is larger than the arrangement surface, and a second .... The frame portion has a second inner surface that intersects with the mating surface and extends upward from the joining surface, forming a rectangular second frame that is smaller than the first frame, and a plane that intersects with at least a part of the second inner surface above the joining surface, and the frame portion has openings that extend from the upper surface to the lower surface of the frame portion, including an opening defined by the first frame and an opening defined by the second frame, the second electrode layer is provided on the plane of the frame portion, and the bottom portion covers the opening of the frame portion defined by the second frame from the lower surface side.

[0008] Furthermore, a base according to the present invention includes a bottom having a mounting surface on which a semiconductor laser element is disposed, a frame to which the bottom is bonded, a first electrode layer, and a second electrode layer electrically connected to the first electrode layer, the bottom having a higher thermal conductivity than the frame, the frame having an upper surface, a lower surface, a bonding surface that is located below the upper surface and above the lower surface and bonds to a part of the mounting surface, a first inner surface that intersects with the bonding surface and extends downward from the bonding surface, forming a rectangular first frame that is larger than the mounting surface, and a second inner surface that intersects with the bonding surface and extends downward from the bonding surface, the first inner surface being larger than the mounting surface. and a plane that intersects with at least a part of the second inner side surface above the bonding surface and extends upward from the bonding surface to form a rectangular second frame that is smaller than the first frame, and the frame portion has openings that extend from the upper surface to the lower surface of the frame portion, including an opening defined by the first frame and an opening defined by the second frame, the second electrode layer is provided on the plane of the frame portion, and the bottom portion covers the opening of the frame portion defined by the second frame from the lower surface side.

[0009] Moreover, the light-emitting device according to the embodiment includes a semiconductor laser element, a base having a bottom made primarily of metal and a frame made primarily of ceramic joined together, the base having an arrangement surface on which the semiconductor laser element is arranged, a frame surrounding the arranged semiconductor laser element, and first and second electrode layers for electrically connecting the semiconductor laser element, the bottom having the arrangement surface, the frame having a bonding surface that bonds with the arrangement surface, an inner side surface that intersects with the bonding surface and forms a frame that is larger than the arrangement surface, and an inner side surface that intersects with the bonding surface and forms a frame that is smaller than the arrangement surface, and the second electrode layer is provided on a plane that intersects with at least a part of the inner side surface that forms the frame that is smaller than the arrangement surface, and is different from the bonding surface. [Effects of the Invention]

[0010] According to the present invention, a light emitting device with excellent heat dissipation properties can be provided. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic perspective view of a light emitting device according to the first embodiment. [Figure 2] FIG. 2 is a top view illustrating the internal structure of the light emitting device according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the light emitting device taken along the line connecting lines III-III in FIG. [Figure 4A] FIG. 4A is a schematic perspective view for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 4B] FIG. 4B is a cross-sectional view taken along a line connecting BI-BI, illustrating the method for manufacturing the light emitting device according to the first embodiment. [Figure 4C] FIG. 4C is a cross-sectional view taken along a line connecting BII-BII for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 4D] FIG. 4D is a schematic perspective view of the bottom of the light emitting device according to the first embodiment. [Figure 4E] FIG. 4E is a top view of the frame of the light emitting device according to the first embodiment. [Figure 4F] FIG. 4F is a bottom view of the frame portion of the light emitting device according to the first embodiment. [Figure 5A] FIG. 5A is a schematic perspective view for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 5B] FIG. 5B is a cross-sectional view taken along a line connecting BI-BI, illustrating the method for manufacturing the light emitting device according to the first embodiment. [Figure 5C] FIG. 5C is a cross-sectional view taken along a line connecting BII-BII for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 6A] FIG. 6A is a schematic perspective view for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 6B] FIG. 6B is a cross-sectional view taken along a line connecting BI-BI, illustrating the method for manufacturing the light emitting device according to the first embodiment. [Figure 6C] FIG. 6C is a cross-sectional view taken along a line connecting BII-BII for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 7A] FIG. 7A is a schematic perspective view for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 7B] FIG. 7B is a cross-sectional view taken along a line connecting BI-BI, illustrating the method for manufacturing the light emitting device according to the first embodiment. [Figure 7C] FIG. 7C is a cross-sectional view taken along a line connecting BII-BII for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 8A] FIG. 8A is a schematic perspective view for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 8B] FIG. 8B is a cross-sectional view taken along a line connecting BI-BI, illustrating the method for manufacturing the light emitting device according to the first embodiment. [Figure 8C] FIG. 8C is a cross-sectional view taken along a line connecting BII-BII for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 9A]FIG. 9A is a schematic perspective view for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 9B] FIG. 9B is a cross-sectional view taken along a line connecting BI-BI, illustrating the method for manufacturing the light emitting device according to the first embodiment. [Figure 9C] FIG. 9C is a cross-sectional view taken along a line connecting BII-BII for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 9D] FIG. 9D is a top view of the substrate of the light emitting device according to the first embodiment. [Figure 10A] FIG. 10A is a schematic view illustrating a method for manufacturing the light emitting device according to the first embodiment. [Figure 10B] FIG. 10B is a cross-sectional view taken along a line connecting BI-BI for explaining the manufacturing method of the light emitting device according to the first embodiment. [Figure 10C] FIG. 10C is a cross-sectional view taken along a line connecting BII-BII for explaining the method for manufacturing the light emitting device according to the first embodiment. [Figure 11] FIG. 11 is a cross-sectional view of the light emitting device according to the second embodiment. [Figure 12A] FIG. 12A is a schematic perspective view of the bottom of the light emitting device according to the second embodiment. [Figure 12B] FIG. 12B is a schematic perspective view of the bottom of the light emitting device according to the second embodiment. [Figure 13] FIG. 13 is a top view of the substrate of the light emitting device according to the second embodiment. [Figure 14] FIG. 14 is a cross-sectional view of a light emitting device according to a first modification. [Figure 15] FIG. 15 is a cross-sectional view of a light emitting device according to a second modification. [Figure 16] FIG. 16 is a schematic perspective view of the bottom of a light emitting device according to a second modification. DETAILED DESCRIPTION OF THE INVENTION

[0012] Modes for carrying out the present invention will be described below with reference to the drawings. However, the modes described below are intended to embody the technical concept of the present invention and are not intended to limit the present invention. Furthermore, in the following description, the same names and symbols indicate the same or similar components, and detailed description will be omitted as appropriate. Note that the size and positional relationship of components shown in each drawing may be exaggerated for clarity of explanation.

[0013] First Embodiment Fig. 1 is a schematic diagram of a light-emitting device 1 according to a first embodiment, Fig. 2 is a top view illustrating the internal structure of the base of the light-emitting device 1, and Fig. 3 is a cross-sectional view taken along the line connecting III-III in Fig. 1. In Fig. 2, in order to illustrate the internal structure, the lid portion 120, adhesive portion 130, and lens member 140 are indicated by dashed lines, and the portions visible when viewed through these members are indicated by solid lines. In addition, to avoid cluttering the drawing, the wire 180 shown in Fig. 3 is omitted in Fig. 2.

[0014] The light emitting device 1 is a device in which light emitted from a plurality of semiconductor laser elements 170 is reflected by the light reflecting surface of the light reflecting member 150, passes through the lens member 140, and is emitted to the outside. As shown in FIG. 2 , three submounts 160 are arranged with semiconductor laser elements 170 disposed thereon, and light reflecting members 150 are disposed corresponding to each semiconductor laser element 170. Each semiconductor laser element 170 emits light toward the corresponding light reflecting member 150, and the light reflecting member 150 reflects the light from the semiconductor laser element 170 toward the lens member 140. The light emitting device 1 also has a package that emits light and a mounting substrate on which the package is mounted. Note that the light emitting device 1 may also be defined as just the package.

[0015] The light emitting device 1 has a substrate 100 as a mounting substrate, and a base 110, a lid 120, an adhesive 130, a lens member 140, a light reflecting member 150, a submount 160, a semiconductor laser element 170, and a wire 180 as components that make up a package. In addition, a plurality of light reflecting members 150 and submounts 160, each of which has a semiconductor laser element 170 arranged thereon, are arranged in a closed space formed by joining the base 110 and the lid 120. Furthermore, wires 180 are stretched to electrically connect the semiconductor laser elements 170 arranged on the base 110. In addition, as shown in FIG. 3 , the base 110 has a frame 111 and a bottom 118.

[0016] Substrate 100 is bonded to at least either frame portion 111 or bottom portion 118. Frame portion 111 is bonded to lid portion 120 on the side opposite to the bonding surface with substrate 100. Lid portion 120 and lens member 140 are bonded via an adhesive, and a gap is created between lid portion 120 and lens member 140 by adhesive portion 130 formed when the adhesive hardens. Light emitting device 1 will be described below while explaining the manufacturing process of light emitting device 1.

[0017] 4A to 10A are schematic diagrams illustrating each step in the manufacture of the light-emitting device 1. Also, FIGS. 4B to 10B and 4C to 10C are cross-sectional views corresponding to each step in FIGS. 4A to 10A. FIGS. 4B to 10B are cross-sectional views corresponding to the line connecting BI-BI in FIG. 4A. FIGS. 4C to 10C are cross-sectional views corresponding to the line connecting BII-BI in FIG. 4A. The dotted lines S1 and S2 are auxiliary lines used to indicate the orientation of the light-emitting device 2 between the drawings and are not components of the light-emitting device 2. The auxiliary lines in the cross-sectional views represent cross-sectional views viewed from the front, with the side on which the auxiliary lines are drawn in the schematic diagrams of FIGS. 4A to 10A. For example, the cross-sectional view of the base 110, marked with line S1 in FIG. 5B, can be considered as a cross-sectional view of the base 110 of FIG. 5A, taken along a line corresponding to the line connecting BI-BI in FIG. 4A, with S1 facing forward.

[0018] 4A and 4D, the frame 111 and bottom 118 that constitute the base 110 are prepared. The bottom 118 can be made of a metal such as Cu or Al, and the frame 111 can be made of a ceramic such as alumina (Al2O3) or AlN. While the materials are not limited to these, at least the bottom 118 has better heat dissipation properties than the frame 111, and the bottom 118 has a higher thermal conductivity than the frame 111.

[0019] The bottom 118 has a rectangular shape with rounded corners at the bonding surface that bonds to the substrate 100 and at the placement surface on which the light reflecting member 150, the submount 160, and the semiconductor laser element 170 are placed. The thickness from the bonding surface to the placement surface is uniform. In the present invention, a rectangular shape in which the corners have been rounded, chamfered, rounded, or otherwise processed is also referred to as a rectangle. Similarly, a polygonal shape in which one or more corners have been rounded or otherwise processed is also referred to as a polygon. Furthermore, when corners of each side of a rectangle or polygon are processed, the processed portions are also considered to be sides. The bonding surface that bonds to the substrate 100 is considered to be the bottom surface. The shapes of the bottom surface and placement surface are not limited to these.

[0020] The frame 111 has a first electrode layer 112 on its bottom surface, which is the surface that bonds to the substrate 100. The first electrode layer 112 is made of, for example, a metal layer, and is bonded to the metal film 103 of the substrate 100. Power is supplied to the semiconductor laser element 170 via the metal film 103. The frame 111 also has a step on the inside of the frame, and the flat surface on the bottom side of this step is the bonding surface 113 with the bottom 118. For convenience, the side of the two opposing flat surfaces that is closer to the substrate 100 will be referred to as the bottom surface, and the opposite side will be referred to as the top surface. Alternatively, the side that is closer to the lens member 140 will be referred to as the top surface, and the opposite side will be referred to as the bottom surface. The frame 111 in FIG. 4A is arranged with its top and bottom surfaces upside down.

[0021] FIG. 4E is a top view of the frame 111, and FIG. 4F is a bottom view of the frame 111. The frame 111 has a bonding surface 113 on the stepped portion plane when viewed from the bottom, and a second electrode layer 114 for electrically connecting to the semiconductor laser element 170 is provided on the stepped portion plane when viewed from the top. The second electrode layer 114 is electrically connected to the first electrode layer 112, for example, via a via hole. The second electrode layer 114 is formed, for example, of a metal layer and disposed on a ceramic layer, and is not exposed on the bottom surface of the stepped portion. Furthermore, while the stepped portion forms all four sides of the frame when viewed from the bottom, the stepped portion is provided only on three sides of the frame when viewed from the top, and is not provided on the remaining side except for the end portion that overlaps with the two opposite sides. In other words, the area having the stepped portion is different when viewed from the top and the bottom. Since the bonding surface 113 in the step portion is bonded to the bottom portion 118, the step portion as viewed from the bottom is provided along the entire periphery. On the other hand, the plane of the step portion as viewed from the top does not necessarily have to be provided along the entire periphery as long as an area for providing the second electrode layer is secured.

[0022] Furthermore, the width of the bonding surface 113 of the edge opposite the edge where the second electrode layer 114 is not provided is larger than that of the other edges. Meanwhile, the width of the bonding surface of the frame 111 that bonds to the substrate 100 is designed to be the same for the edge where the second electrode layer 114 is not provided and the edge opposite that edge. In other words, the shortest distance between the two side surfaces of the frame 111 that intersect with the bonding surface of the substrate 100 is equal at corresponding positions on the opposing edges. Note that "equal" refers to a relationship in which the difference between two or more values ​​being compared is within the tolerance range due to design tolerance. This allows for a balance of the force applied to the base 110 when bonding to the substrate 100 by soldering. Note that the corresponding positions of opposing edges refer to the position of one edge and the position of the other edge that is the shortest distance from that position when the two opposing edges are parallel.

[0023] Next, as shown in FIG. 5A, the joining surface 113 of the frame 111 and the bottom 118 are joined together. For example, a silver solder containing Ag as a main component and Cu can be used for the joining, but other metal solders can also be used. As shown in FIG. 4A, the frame 111 is placed with the bottom surface that will be joined to the substrate 100 facing up, and silver solder is applied to the joining surface. After the silver solder is melted by heating, the bottom 118 is fitted into the frame of the frame 111. The silver solder is then cooled to join the frame 111 and the bottom 118, thereby forming the base 110. The joining area between the frame 111 and the bottom 118 is plated with Ni before the silver solder is applied.

[0024] 5B and 5C, the size of the bonding surface of bottom portion 118 that bonds with frame portion 111 is smaller than, and is encompassed by, the frame formed by inner side surface 115 that intersects with the bottom surface of frame portion 111. Furthermore, the shapes of inner side surface 115 of frame portion 111 and side surface 119 of bottom 118 are designed so that the placement surface of bottom portion 118 bonds with bonding surface 113 at the step portion of frame portion 111. In light emitting device 1 according to the first embodiment, the length from the bottom surface of frame portion 111 to bonding surface 113 and the height of bottom portion 118 are designed to be the same, and bottom portion 118 is fitted into the frame formed by inner side surface 115 that intersects with bonding surface 113.

[0025] Furthermore, a gap is generated between the inner surface 115 and the side surface 119. As mentioned above, the frame 111 can be formed from ceramic, but the degree of sintering during manufacturing is not always the same. This may result in differences in the shape and size of the manufactured frame portions 111. In manufacturing the light-emitting device 1, the shapes of the frame 111 and the bottom 118 are designed to allow for a gap of approximately 0.1 mm between them, taking into account design tolerances. Note that the design may provide a gap of 0.1 mm or more, or a gap of 0.1 mm or less. Preferably, the gap is set between 0.1 mm and 0.5 mm. This allows the bottom 118 to be properly bonded to the bonding surface of the frame 111 and improves the heat dissipation properties of the bottom 118, resulting in a base 110 with excellent heat dissipation properties.

[0026] The size of the plane of bottom 118 that joins with joining surface 113 is larger than the outer frame of the space formed by the step portion. Specifically, the size of the plane of bottom 118 that joins with joining surface 113 of frame portion 111 is larger than the frame formed by inner side surface 116 at the inner end of joining surface 113, and bottom 118 covers this frame.

[0027] Furthermore, the relationship between the frame formed by inner surface 115 at the inner end of the bottom surface of frame portion 111 and the frame formed by inner surface 117 at the inner end of the top surface of frame portion 111 is such that inner surface 115 is larger than inner surface 117 when viewed in the S1 direction, and inner surfaces 115 and 117 are equal in size when viewed in the S2 direction. In the S1 direction, there is a side that does not have a step portion for the second electrode layer when viewed from above, and the bottom surface is larger than the top surface because a bonding surface is formed on this side. In the S2 direction, both sides have a step portion for the second electrode layer, so the bonding surface can be formed using this step portion, and therefore the bottom surface does not need to be larger.

[0028] When viewed from the S2 direction, the frame portion 111 has a first electrode layer on its bottom surface on both sides. From the perspective of heat dissipation, a larger bottom portion 118 is desirable, but if the width of the bottom portion is narrow, there is a risk that the solder may come into contact with or electrically connect both the first electrode layer and the bottom portion 118 during soldering. Although the inner surfaces 115 and 117 do not need to be aligned when viewed from the S2 direction, the size of the inner surface 115 is such that it is located at a predetermined distance from the first electrode layer. Preferably, the position of the inner edge on the bottom surface is determined so that a gap of approximately 0.3 mm is provided between the first electrode layer, which has a width of approximately 0.5 mm. The first electrode layer 112 and the second electrode layer 114 are electrically connected via a conductive portion provided inside the frame portion 111.

[0029] Here, we will provide additional information regarding the determination of the structure of the frame 111 and the bottom 118. From the viewpoint of heat dissipation, it is desirable for the bottom 118 to be made of a material with good heat dissipation properties so that heat can be diffused from the position where the semiconductor laser element 170, which is the main heat source, is disposed, and therefore a metal such as Cu is preferable to ceramic. It is also preferable that the bottom 118 has a certain size, and the exposed portion as the mounting surface is preferably made of metal. Furthermore, in order to bond to the substrate 100 and efficiently dissipate heat from there to the substrate 100, it is preferable not to sandwich a material with poor heat dissipation properties between the mounting surface and the bonding surface with the substrate 100.

[0030] Furthermore, from the viewpoints of strength and shape stability when using the light emitting device 1, it is preferable to use ceramic for the outer frame of the base. Furthermore, a step must be provided in part of the ceramic frame to provide a metal layer for electrically connecting the semiconductor laser element. For this reason, the base 110 of the light emitting device 1 must at least include a frame that surrounds the periphery, a bottom portion on which the semiconductor laser is disposed, and a step for providing the metal layer.

[0031] The step does not need to be provided along the entire circumference of the frame, and the area where the step is provided can be adjusted as appropriate depending on the number of semiconductor laser elements 170 arranged in the light emitting device 1, the combination when arranging multiple semiconductor laser elements 170, etc. For example, it may be sufficient to provide the step along one or two sides of the frame, or it may be necessary to provide the step along the entire circumference. When arranging multiple semiconductor laser elements 170, the combination may be, for example, whether multiple semiconductor laser elements of the same color and performance are arranged, or whether semiconductor laser elements of different colors are arranged.

[0032] Taking these factors into consideration, the frame 111 and bottom 118 of the light emitting device 1 are formed of ceramic while the bottom 118 is made of metal, and a separation between the frame and bottom is determined to improve heat dissipation. Furthermore, a gap is provided in consideration of the design tolerance of the ceramic. Therefore, it is possible to provide a base 110 with better heat dissipation properties than one in which the mounting surface of the base 110 on which the semiconductor laser element 170 is mounted is made of ceramic.

[0033] 6A, the light reflecting member 150 and the submount 160 on which the semiconductor laser element 170 is disposed are bonded to the placement surface of the formed base 110. The positions at which the light reflecting member 150 and the submount 160 are disposed are determined based on the positions based on the frame 111, not the positions based on the bottom 118. In other words, the light reflecting member 150 and the submount 160 are disposed so that the distance and coordinates from a specific position on the frame 111 match, rather than the distance and coordinates from a specific position on the bottom 118.

[0034] As described above, a gap is generated between the frame 111 and the bottom 118, and therefore the bottom 118 is not fixed by the frame formed by the frame 111. Therefore, there is a possibility that the bottom 118 may move when joined by brazing. For example, in the light emitting device 1, the shape of the frame of the frame 111 and the shape of the joining surface of the bottom 118 are similar to each other, but as a result of joining, their respective center points may not coincide, or the distances from the frame 111 to the bottom 118 may not be uniform. Therefore, even if the bottom 118 is misaligned, it is preferable to adjust the position of the bottom 118 so that it is aligned with the frame 111, so that the light emitting devices 1 to be manufactured can be easily aligned. Note that the smaller the gap between the frame 111 and the bottom 118 described above, the smaller the misalignment due to movement.

[0035] The light-reflecting member 150 has a light-reflecting surface on at least one side. Since the light-reflecting member 150 receives the light emitted from the semiconductor laser elements 170, it is desirable to use a heat-resistant material as the main material and a highly reflective material for the light-reflecting surface. The main material may be glass, such as quartz or BK7 (borosilicate glass), metal, such as aluminum, or Si, and the light-reflecting surface may be made of metal or a dielectric multilayer film. The light-emitting device 1 may have a light-reflecting member 150 with multiple light-reflecting surfaces as needed, or may include other light-reflecting members in addition to the light-reflecting member 150. While one light-reflecting member 150 is provided for each semiconductor laser element 170, one light-reflecting member 150 may be provided for three semiconductor laser elements 170, or one light-reflecting member may be provided for multiple semiconductor laser elements.

[0036] Aluminum nitride or silicon carbide can be used for the submount 160. A metal film is provided on the submount 160, and the semiconductor laser element 170 is fixed to the submount 160 by a conductive layer such as Au—Sn.

[0037] The semiconductor laser element 170 is bonded to the submount 160 at its bottom surface, and emits light from the side surface closer to the light reflecting member 150. The laser light emitted from the semiconductor laser element 170 has an elliptical far-field pattern (hereinafter referred to as "FFP") in a plane parallel to the light emitting end surface, in which the length in the stacking direction of multiple semiconductor layers including the active layer is longer than the length in the direction perpendicular to the stacking direction. The FFP here is a measurement of the light intensity distribution of the emitted light in a plane that is some distance from the light emitting end surface of the semiconductor laser element and parallel to the light emitting end surface. The shape of the FFP is specified as the shape of the main part of the light. Here, the main part of the light from the laser element is defined as the shape that is 1 / e from the peak intensity value of the laser light. 2 This refers to the portion of the intensity range up to where it drops to any intensity such as

[0038] The light emitting device 1 has one or more semiconductor laser elements 170, and as shown in Figures 6A to 6C, three semiconductor laser elements 170 are arranged. The number of arranged semiconductor laser elements 170 is not limited to this and may be one or more. Furthermore, the light emitted by these semiconductor laser elements 170 may be the same color or different colors. For example, the three semiconductor laser elements 170 included in the light emitting device 1 may each be composed of a first semiconductor laser element that emits red light, a second semiconductor laser element that emits green light, and a third semiconductor laser element that emits blue light.

[0039] The emission peak wavelength of red light is, for example, in the range of 605 nm to 750 nm. Examples of red-emitting semiconductor laser elements include those containing InAlGaP-based, GaInP-based, GaAs-based, and AlGaAs-based semiconductors. The emission peak wavelength of green light is, for example, in the range of 495 nm to 570 nm. Examples of semiconductor laser elements that emit green laser light include semiconductor laser elements containing nitride semiconductors. The emission peak wavelength of blue light is, for example, in the range of 420 nm to 494 nm. Examples of semiconductor laser elements that emit blue laser light include semiconductor laser elements containing nitride semiconductors. Examples of nitride semiconductors that can be used are GaN, InGaN, and AlGaN.

[0040] 7A, a wire is bonded to the second electrode layer 114 of the frame portion 111 and the semiconductor laser element 170, thereby electrically connecting the second electrode layer 114 and the semiconductor laser element 170. For example, a wire bonding device is used to bond one end of an Au wire to the semiconductor laser element 170 and the other end to the second electrode layer 114. If a protection element such as a Zener diode is disposed on the submount 160, the protection element is also electrically connected by the wire 180.

[0041] As shown in FIGS. 6A and 6B , a step for providing the second electrode layer 114 is provided along three sides in a top view, with one side being absent except for the overlapping portion with the other side. This side is the side where the light reflecting member 150 is present between the semiconductor laser element 170 or the submount 160 and the semiconductor laser element 170, sandwiching the light reflecting member 150 between the side and the semiconductor laser element 170. Light emitted from the semiconductor laser element 170 is reflected by the light reflecting member 150 and travels upward. As is clear from FIGS. 7A and 7B , if a step were provided on that side to electrically connect the second electrode layer 114 on that side to the semiconductor laser element 170 with a wire, the wire would be in the light's traveling direction, blocking the light. Therefore, by not providing a step for the second electrode layer 114 on the side facing the light reflecting member 150, the second electrode layer 114 can be appropriately positioned, contributing to a reduction in the size of the light-emitting device 1.

[0042] 8A, the frame 111 of the base 110 and the lid 120 are joined together, and the space in which the semiconductor laser element 170 is disposed is hermetically sealed. For example, a metal film is provided on the underside of the lid 120 in an area that is joined to the base 110, and the base 110 and the lid 120 are joined and fixed together via AuSn or the like. Since the semiconductor laser element 170 is disposed in this closed space, it is possible to prevent organic matter and the like from collecting on the light-emitting end face of the semiconductor laser element 170.

[0043] The lid 120 can be made of, for example, glass with a metal film or sapphire with a metal film, with sapphire with a metal film being preferred. When light spreads, the size of the lens portion that passes the light increases, but sapphire has a relatively high refractive index and can suppress the spread of light, making it possible to reduce the size of the lens portion of the lens member 140. Furthermore, since sapphire is relatively strong and therefore less likely to break, it is possible to ensure reliable airtightness of the closed space.

[0044] In FIG. 9A, the base 110 is mounted on the substrate 100. The substrate 100 is bonded to the frame 111 of the base 110 and the bottom surface of the bottom 118. The bonding can be performed by soldering. As shown in FIGS. 9B and 9C, the substrate 100 has a heat dissipation portion 101, an insulating portion 102, and a metal film 103. The heat dissipation portion 101 is formed of a metal such as Cu, the insulating portion 102 is formed of an insulating material, and the metal film 103 is formed of a metal such as Cu, just like the heat dissipation portion 101.

[0045] The heat dissipation portion 101 is bonded to the bottom 118 of the base 110, and the metal film 103 or the insulating portion 102 is bonded to the frame 111. Therefore, the substrate 100 is designed so that the metal film 103 and the heat dissipation portion 101 are provided on the same plane. Specifically, the heat dissipation portion 101 has a convex structure that protrudes toward the base 110 in a cross-sectional or side view, and is shaped so as to be exposed in the region where it is bonded to the bottom 118 of the base 110. On the other hand, the heat dissipation portion 101 does not protrude in the region where the substrate 100 is bonded to the frame 111, and the insulating portion 102 is disposed on top of the heat dissipation portion 101. Furthermore, in the bonding region of the substrate 100 corresponding to the side of the frame 111 where the first electrode layer 112 is provided, the metal film 103 is provided on top of the insulating portion 102. Furthermore, the heat dissipation portion 101 and the metal film 103 do not contact each other and are spaced a predetermined distance apart to prevent electrical connection. A part of this region with a predetermined gap therebetween overlaps with a part of the gap between frame portion 111 and bottom portion 118 .

[0046] 9D is a top view of the bonding surface of substrate 100 that bonds with base portion 110. As shown in FIG. 9D, substrate 100 has, on the bonding surface, insulating portion 102, metal film 103, and exposed portion 106 where heat dissipation portion 101 is exposed. Metal film 103 also has metal region 104 and insulating region 105. Exposed portion 106 bonds with bottom portion 118, and metal region 104 bonds with the bottom surface of frame portion 111.

[0047] The shape of exposed portion 106 represents the area where heat dissipation portion 101 protrudes. This shape is designed to match the shape of the bottom surface of bottom portion 118 and to be slightly larger. If they were the same size, the solder would not be able to escape to the outside of the bonding surface during soldering, resulting in an extra thickness between substrate 100 and base portion 110. Furthermore, the side of metal region 104 that is closer to the center of substrate 100, with insulating region 105 in between, is bonded to frame portion 111. This bonding electrically connects metal region 104 and first electrode layer 112.

[0048] In this way, by aligning the height of the metal film 103, which is provided across the insulating portion 102, and the exposed portion 106 of the heat dissipation portion 101, it is possible to reduce the floating that may occur between the frame portion 111 or the bottom portion 118 when bonding to the base portion 110. If the floating becomes large, the bonding strength will weaken or partial unbonded areas will be created, increasing the possibility that the package will come off the mounting substrate. Furthermore, by bonding the entire bottom surface of the bottom portion 118 to the exposed portion 106 of the heat dissipation portion 101, heat can be efficiently released to the substrate 100.

[0049] In FIG. 10A , the lens member 140 is bonded to the lid member 120 using an adhesive. This bonding process forms an adhesive portion 130 between the lid member 120 and the lens member 140, thereby producing the light-emitting device 1 shown in FIGS. 1 to 3 . The adhesive portion 130 is not formed over the entire upper surface of the lid member 120 or the entire lower surface of the lens member 140, but is provided in a position that does not interfere with the path of light emitted from the semiconductor laser element 170. Specifically, in the light-emitting device 1, the majority of the light emitted by the semiconductor laser element 170 enters and exits the lens-shaped region of the lens member 140. Therefore, it is preferable that the adhesive portion 130 is not formed on the lower surface of the lens member 140 corresponding to the lens-shaped region, but is formed in the outer edge region of the lens member 140. A UV-curable resin is preferably used as the adhesive for forming the adhesive portion 130. UV-curable resin can be cured in a relatively short time without heating, making it easy to fix the lens member 140 in the desired position.

[0050] 10B and 10C, the lens member 140 has a lens shape in which multiple lens portions are connected together. Each lens portion corresponds to one semiconductor laser element, and each lens portion is designed to pass a major portion of the light emitted from a different semiconductor laser element. The lens member 140 can be made of glass such as BK7 or B270.

[0051] In this manner, the light emitting device 1 according to the first embodiment is manufactured. Note that the process for manufacturing the light emitting device 1 is not limited to the process described with reference to FIGS.

[0052] Second Embodiment FIG. 11 shows a cross-sectional view of a light emitting device 2 according to the second embodiment. The schematic diagram of the exterior of the light emitting device 2 is the same as that shown in FIG. 1, and the internal structure as viewed from above is also the same as that shown in FIG. 2. The light emitting device 2 according to the second embodiment differs from the light emitting device 1 according to the first embodiment in the structure of the bottom that constitutes the base. In particular, the bonding surface of the bottom that bonds to the substrate is different from that of the first embodiment, and as long as the shapes of the insulating portion and exposed portion on the bonding surface of the substrate are adapted to this, the structure, materials, etc. described in the first embodiment can be adopted in other respects.

[0053] As explained in the process of FIG. 5A for the light-emitting device 1 of the first embodiment, when the frame portion 111 and the bottom portion 118 are joined, it is desirable that the bottom portion 118 be positioned so that the distance from the frame portion 111 is uniform everywhere. However, it is conceivable that the bottom portion 118 may be misaligned during the joining process. If the misalignment becomes significant, a portion of the bottom portion 118 will come into contact with the frame portion 111. Furthermore, if the distance between the bottom portion 118 and the frame portion 111 becomes narrower than the designed distance, and the distance between the first electrode layer 112 and the bottom portion 118 at that portion becomes shorter, the first electrode layer 112 and the bottom portion 118 may be electrically connected when the frame portion 111 and the bottom portion 118 are joined to the substrate 100 by soldering, which may result in a defect in the light-emitting device.

[0054] Therefore, in the light emitting device 2 according to the second embodiment, a recess 214 is provided at least on the outer edge of the bonding surface 215 of the bottom 213 with the substrate 200. By doing so, the distance between the frame 211 and the bottom 213 at the bottom surface of the base 210, which is the bonding surface 215 with the substrate 200, is made wider than the distance between the frame 211 and the bottom 213 at the bonding surface 212 with the frame 211.

[0055] 12A and 12B show examples of a bottom 213 having a recessed portion 214. As an example, the recess can be formed by making the bottom 213 convex. The protruding region of the convex shape becomes the bonding surface 215 with the substrate 200, and its shape can be a scaled-down shape similar to the shape of the outer frame of the bottom 213 as shown in FIG. 12A, or a circular shape as shown in FIG. 12B. FIG. 13 is a schematic diagram showing the bonding surface of the substrate 200 when the protruding region is circular. As shown in FIG. 13, the exposed portion 201 also has a circular shape to match the bonding surface 215 of the base 210.

[0056] The recesses 214 need only be spaced and tall enough to prevent the above-described defects from occurring during the soldering process with the substrate 200. For example, the light-emitting device 1 of the first embodiment is designed to have a gap of approximately 0.1 mm. If a minimum gap of approximately 0.1 mm is required, the width of the recesses can be designed to be approximately 0.1 mm. In this way, even if the frame 211 and the bottom 213 are in contact with each other at the joint surface 212 with the frame 211, the gap between the frame 211 and the bottom 213 at the joint surface with the substrate 200 can be maintained at approximately 0.1 mm. Furthermore, for example, the light-emitting device 1 of the first embodiment is designed so that the distance from the side surface 119 of the bottom 118 to the first electrode layer 112 is 0.3 mm or more. Similarly, the width of the recesses may be designed taking into account the design of the frame so that the distance to the first electrode layer 112 is maintained at approximately 0.3 mm. The 0.3 mm spacing is an example of the design of the light emitting device 1, and the predetermined spacing to be provided may be determined appropriately depending on the shape, material, etc. of the light emitting device.

[0057] Therefore, it is preferable to provide recess 214 so that it has a width approximately equal to the gap that would be secured if bottom 213 did not have recess 214 and there were no misalignments relative to frame 211. Note that recess 214 may be wider than this, or may have a shape in which a portion of the protruding region is wider than this, such as bottom 213 with a circular protrusion as shown in FIG. 12. However, since a wider recess also reduces the bonding area with substrate 200, it is desirable not to make the width of the recess wider than necessary to secure sufficient bonding, and a width of 0.1 mm to 0.5 mm is desirable. For example, when a circular bonding surface as shown in FIG. 12 is provided, it is conceivable to design the recess so that the narrowest position has a width approximately equal to the gap that would be secured.

[0058] The height ensured by recess 214 should be high enough so that the solder that overflows from bonding surface 215 of bottom 213 with substrate 200 can rise along the side surface that intersects with bonding surface 215 with substrate 200 and remain within the recess. The desired height to ensure varies depending on the material and amount of solder used for bonding, but for example, a height of about 0.2 mm is ensured in light emitting device 2.

[0059] In addition, when the bonding surface with the substrate has a shape like a rectangle or a square with the four corners processed, such as bottom 118 described in light-emitting device 1 or bottom 213 shown as an example in Figure 12, the exposed part on the substrate side is also shaped to match this, which allows self-alignment to occur when the bottom is bonded to the substrate.

[0060] 12 as an example, if the bonding surface with the substrate 200 is circular, exposed portion 201 on the substrate side is also provided in a circular shape to match this, so that the bonding surface of bottom portion 213 fits within exposed portion 201, but even when substrate 200 and bottom portion 213 are in contact with each other via solder, there is still movement in the direction of rotation of the circle until the solder hardens. As described above, if there is a misalignment between frame portion 211 and bottom portion 213, the rotation direction can be adjusted by making bonding surface 215 with substrate 200 circular, and the misalignment of frame portion 211 with respect to substrate 200 can be corrected.

[0061] <First Modification> The light emitting device 3 of the first variant is realized in a way different from the light emitting device 2 shown in the second embodiment, in that the distance between the frame and the bottom at the joint surface with the substrate is wider than the distance between the frame and the bottom at the joint surface with the frame.

[0062] Fig. 14 shows a cross-sectional view of a light emitting device 3 according to a first modification. As shown in Fig. 14, the light emitting device 3 has a recess 312 in a frame 311, so that the distance between the frame 311 and the bottom 313 at the bonding surface with the substrate 300 is wider than the distance between the frame 311 and the bottom 313 at the bonding surface with the substrate 300. In this way, this may be achieved by processing the shape of the frame 311, and unlike the light emitting device 2, the light emitting device 3 can use the substrate 100 of the first embodiment as is.

[0063] <<Second Modification>> FIG. 15 shows a cross-sectional view of a light emitting device 4 according to a second modified example. FIG. 16 shows a schematic diagram of a bottom according to the second modified example. As shown in FIG. 15, in the light emitting device 4, the bonding surface with the substrate 400 at the bottom 412 is smaller than the bonding surface with the frame 411, and the side surface 413 is inclined. By providing an inclination to the side surface 413 in this manner, the distance between the frame 411 and the bottom 412 at the bonding surface with the substrate 400 can be made wider than the distance between the frame 411 and the bottom 412 at the bonding surface with the frame 411. Note that, as in the first modified example, instead of providing an inclination to the bottom 412, an inclination may be provided to the frame 411.

[0064] The light-emitting device according to the present invention has been described above based on various embodiments and modifications, but light-emitting devices that realize the technical concept of the present invention are not limited to these. For example, while a light-emitting device in which three semiconductor laser elements are arranged has been described, a light-emitting device in which one or more semiconductor laser elements are arranged may also be used. Furthermore, a light-emitting device may not have a light-reflecting member 150, and light emitted from the semiconductor laser elements may travel in the direction of the lens member 140.

[0065] Furthermore, light-emitting devices having the technical features disclosed by the present invention are not limited to the structures of light-emitting devices 1 to 4. For example, the present invention can be applied to light-emitting devices having components not disclosed in any of the light-emitting devices, and differences from the disclosed light-emitting devices do not constitute grounds for saying that the present invention cannot be applied.

[0066] On the other hand, the present invention can be applied even if it is not essential to have all the necessary and sufficient components of the light-emitting device disclosed in each embodiment and modification. For example, if some components of the light-emitting device disclosed in the first embodiment are not recited in the claims, the invention described in the claims is claimed to be applicable, with the freedom of design by those skilled in the art to include, but not limited to, those components disclosed in this embodiment, such as substitution, omission, modification of shape, and change of material. [Industrial Applicability]

[0067] The light emitting device according to each embodiment can be used in projectors, vehicle headlights, lighting, display backlights, and the like. [Explanation of symbols]

[0068] 1...Light emitting device 100...Substrate 101...Heat radiation part 102...insulation part 103...Metal film 104…Metal area 105...Isolation area 106...Exposed part 110...Base 111...Frame 112...First electrode layer 113...Joint surface 114…Second electrode layer 115...Inner surface 116...Inner surface 117...Inner surface 118…Bottom 119...side 120...Lid part 130...Adhesive part 140...Lens component 150...Light reflecting member 160...Submount 170...Semiconductor laser element 180...wire 2...Light-emitting device 200...Substrate 201...Exposed part 210...Base 211...frame section 212...Joint surface 213…Bottom 214...Depression 215…Joint surface 3...Light-emitting device 300...Substrate 310...Base 311...frame 312...recess 313…Bottom 4...Light-emitting device 400...Substrate 410...Base 411...frame section 412…Bottom 413...Side

Claims

1. one or more light emitting elements; a base having a bottom portion made primarily of metal and having a first upper surface, and a frame portion made primarily of ceramic and having a joining surface joined to the first upper surface and a second upper surface located above the first upper surface; a lid portion made primarily of glass or sapphire and having a lower surface bonded to the second upper surface; Equipped with The frame and the bottom are Ni-plated and joined with a metal brazing material, the frame and the lid are joined with AuSn, The one or more light-emitting elements are disposed in a closed space formed by joining the bottom, the frame, and the lid.

2. The light emitting device according to claim 1 , wherein a metal film is provided on the lower surface of the lid in an area bonded to the base.

3. 3. The light-emitting device according to claim 1, wherein the metal that is the main material of the bottom portion is Cu or Al.

4. The ceramic that is the main material of the frame is Al ２ O ３ The light-emitting device according to claim 1 , wherein the material is selected from the group consisting of silicon nitride and aluminum nitride, and the material is AlN.

5. The light emitting device according to claim 1 , wherein the closed space is a hermetically sealed space.

6. The light emitting device according to claim 1 , further comprising a substrate on which the base is mounted.

7. The light emitting device according to claim 6 , wherein the substrate is soldered to the bottom and the frame.

8. the substrate has a heat dissipation portion and a metal film electrically connected to the one or more light emitting elements, the heat dissipation portion is joined to the bottom, The light-emitting device according to claim 6 or 7, wherein the metal film is not bonded to the bottom.

9. The light emitting device according to claim 1 , further comprising a lens member bonded to the lid portion by an adhesive.

10. The light emitting device according to claim 1 , wherein the one or more light emitting elements are semiconductor laser elements.

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