Light-emitting device and base

Abstract

To provide a light emitting device that is excellent in heat dissipation properties.SOLUTION: A light emitting device comprises: a semiconductor laser element; and a base in which a bottom part including metal as a chief material and a frame part including ceramics as a chief material are joined to each other. The base has an arrangement surface on which the semiconductor laser element is arranged, a frame that surrounds the periphery of the arranged semiconductor laser element, and first and second electrode layers for electrically connecting the semiconductor laser element. The bottom part has the arrangement surface. The frame part has a joint surface that is joined to the arrangement surface, an inside surface that intersects the joint surface and forms a frame larger than the arrangement surface, and an inside surface that intersects the joint surface and forms a frame smaller than the arrangement surface. The second electrode layer is provided on a plane that intersects at least part of the inside surface of the frame part forming the frame smaller than the arrangement surface, and that is different from the joint surface.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a light-emitting device and a base.

Background Art

[0002] Conventionally, a light-emitting element package in which a light-emitting element such as an LED element or a semiconductor laser element is arranged on the bottom surface of a base having a frame and a bottom surface has been known. Further, several materials can be adopted for the base serving as the package body, and for example, one of them is ceramic. Patent Document 1 discloses a light-emitting element package in which a light-emitting element is arranged on a package body whose surface is formed of a ceramic layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, since a light-emitting element such as a semiconductor laser element generates heat, it is necessary to consider heat dissipation when manufacturing the package. The light-emitting element package of Patent Document 1 discloses a structure in which the light-emitting element is arranged on the ceramic, but there is room for improvement in terms of heat dissipation.

Means for Solving the Problems

[0005] The light-emitting device according to the present invention includes a semiconductor laser element, a bottom portion mainly made of metal, a frame portion mainly made of ceramic to which the bottom portion is joined, a first electrode layer, and a second electrode layer electrically connected to the first electrode layer, and includes a base portion having the second electrode layer provided on the plane of the frame portion, and the first electrode layer and the second electrode layer are electrically connected to the semiconductor laser element. In a top view, the semiconductor laser element is surrounded by the second frame. The bottom portion has an arrangement surface on which the semiconductor laser element is disposed. The frame portion has an upper surface, a lower surface, a joining surface provided below the upper surface and above the lower surface and joined to a part of the arrangement surface, a first inner surface that intersects the joining surface and extends downward from the joining surface and forms a first frame that is a rectangle larger than the arrangement surface, a second inner surface that intersects the joining surface and extends upward from the joining surface and forms a second frame that is a rectangle smaller than the first frame, and a plane that intersects at least a part of the second inner surface above the joining surface. An opening extending 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, is formed in the frame portion. The second electrode layer is provided on the plane of the frame portion, and the first electrode layer and the second electrode layer are electrically connected to the semiconductor laser element. In a top view, the semiconductor laser element is surrounded by the second frame.

[0006] In addition, the 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 disposed, a frame portion to which the bottom portion is joined, a first electrode layer, and a second electrode layer electrically connected to the first electrode layer, and includes a base portion. The bottom portion has a higher thermal conductivity than the frame portion. The frame portion has an upper surface, a lower surface, a joining surface provided below the upper surface and above the lower surface and joined to a part of the arrangement surface, a first inner surface that intersects the joining surface and extends downward from the joining surface and forms a first frame that is a rectangle larger than the arrangement surface, a second inner surface that intersects the joining surface and extends upward from the joining surface and forms a second frame that is a rectangle smaller than the first frame, and a plane that intersects at least a part of the second inner surface above the joining surface. An opening extending 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, is formed in the frame portion. 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. In a top view, the semiconductor laser element is surrounded by the second frame.

[0007] Further, the base according to the present invention includes a bottom portion mainly made of metal, a frame portion mainly made of ceramic to which the bottom portion is joined, a first electrode layer, and a second electrode layer electrically connected to the first electrode layer. The bottom portion has an arrangement surface on which a semiconductor laser element is disposed. The frame portion has an upper surface, a lower surface, a joining surface provided below the upper surface and above the lower surface and joined to a part of the arrangement surface, a first inner surface that intersects the joining surface and extends downward from the joining surface to form a first frame that is a rectangle larger than the arrangement surface, a second inner surface that intersects the joining surface and extends upward from the joining surface to form a second frame that is a rectangle smaller than the first frame, and a plane that intersects at least a part of the second inner surface above the joining surface. An opening extending 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, is formed in the frame portion. The second electrode layer is provided on the plane of the frame portion. The bottom portion covers the opening of the frame portion defined by the second frame from the lower surface side.

[0008] Further, the base according to the present invention includes a bottom portion having an arrangement surface on which a semiconductor laser element is disposed, a frame portion to which the bottom portion is joined, a first electrode layer, and a second electrode layer electrically connected to the first electrode layer. The bottom portion has a higher thermal conductivity than the frame portion. The frame portion has an upper surface, a lower surface, a joining surface provided below the upper surface and above the lower surface and joined to a part of the arrangement surface, a first inner surface that intersects the joining surface and extends downward from the joining surface to form a first frame that is a rectangle larger than the arrangement surface, a second inner surface that intersects the joining surface and extends upward from the joining surface to form a second frame that is a rectangle smaller than the first frame, and a plane that intersects at least a part of the second inner surface above the joining surface. An opening extending 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, is formed in the frame portion. The second electrode layer is provided on the plane of the frame portion. The bottom portion covers the opening of the frame portion defined by the second frame from the lower surface side.

[0009] In addition, the light-emitting device according to the embodiment includes a semiconductor laser element, a base portion in which a bottom portion mainly made of metal and a frame portion mainly made of ceramic are joined, the base portion 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 portion having an arrangement surface, the frame portion having a joining surface that joins with the arrangement surface, an inner surface that intersects with the joining surface and forms a frame larger than the arrangement surface, and an inner surface that intersects with the joining surface and forms a frame smaller than the arrangement surface, and the second electrode layer is provided on a plane that intersects at least a part of the inner surface forming a frame smaller than the arrangement surface in the frame portion and is different from the joining surface.

Effect of the Invention

[0010] According to the present invention, a light-emitting device excellent in heat dissipation can be provided.

Brief Description of the Drawings

[0011]

Figure 1

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Figure 3

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Figure 8A

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Figure 16

DETAILED DESCRIPTION OF THE INVENTION

[0012] Embodiments for carrying out the present invention will be described below with reference to the drawings. However, the embodiments shown below are for embodying the technical idea of the present invention and do not limit the present invention. Further, in the following description, the same names and reference numerals indicate the same or equivalent members, and detailed descriptions will be omitted as appropriate. Note that the sizes and positional relationships of the members 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 the first embodiment, FIG. 2 is a top view for explaining the internal structure of the base of the light emitting device 1, and FIG. 3 shows a cross-sectional view in the direction of the arrow along the straight line connecting III-III of FIG. 1. In FIG. 2, for showing the internal structure, the lid portion 120, the adhesive portion 130, and the lens member 140 are shown by broken lines, and the portions seen when passing through these members are shown by solid lines. Also, to avoid complication of 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 through 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 the semiconductor laser elements 170 respectively, and the light reflecting member 150 is arranged corresponding to each semiconductor laser element 170. Each semiconductor laser element 170 emits light to the corresponding light reflecting member 150, and the light reflecting member 150 reflects the light from the semiconductor laser element 170 in the direction of the lens member 140. Further, the light emitting device 1 has a package that emits light and a mounting substrate on which the package is mounted. Note that only the package may be regarded as the light emitting device 1.

[0015] The light-emitting device 1 includes a substrate 100 as a mounting substrate, a base 110, a lid 120, an adhesive portion 130, a lens member 140, a light reflection member 150, a submount 160, a semiconductor laser element 170, and a wire 180 as components constituting the package. Further, in a closed space formed by joining the base 110 and the lid 120, a plurality of light reflection members 150 and submounts 160 each having a semiconductor laser element 170 disposed thereon are arranged. Furthermore, a wire 180 for electrically connecting the semiconductor laser element 170 disposed on the base 110 is stretched. Also, as shown in FIG. 3, the base 110 has a frame portion 111 and a bottom portion 118.

[0016] The substrate 100 is joined to at least one of the frame portion 111 or the bottom portion 118. Also, on the side opposite to the joining surface with the substrate 100, the frame portion 111 is joined to the lid 120. The lid 120 and the lens member 140 are joined via an adhesive, and a gap is formed between the lid 120 and the lens member 140 by the adhesive portion 130 formed by the curing of the adhesive. Hereinafter, the light-emitting device 1 will be described while explaining the manufacturing process of the light-emitting device 1.

[0017] FIGS. 4A to 10A are schematic diagrams for explaining each step until the light-emitting device 1 is manufactured. Also, FIGS. 4B to 10B and FIGS. 4C to 10C respectively show cross-sectional views in each step corresponding to FIGS. 4A to 10A. FIGS. 4B to 10B are cross-sectional views corresponding to the straight line connecting BI-BI shown in FIG. 4A. FIGS. 4C to 10C are cross-sectional views corresponding to the straight line connecting BII-BII shown in FIG. 4A. The dotted lines S1 and S2 are auxiliary lines for showing the correspondence of the orientation of the light-emitting device 2 between the drawings and are not components of the light-emitting device 2. Also, the auxiliary lines in the cross-sectional views represent that they are cross-sectional views when looking at the side where the auxiliary lines are drawn in the schematic diagrams of FIGS. 4A to 10A as the front. For example, the cross-sectional view of the base 110 where the S1 line is drawn in FIG. 5B can be said to be a cross-sectional view of a straight line corresponding to the straight line connecting BI-BI in FIG. 4A of the base 110 as seen with S1 as the front.

[0018] First, as shown in FIGS. 4A and 4D, a frame portion 111 and a bottom portion 118 that constitute the base portion 110 are prepared respectively. As the bottom portion 118, metals such as Cu or Al can be used, and as the frame portion 111, ceramics such as alumina (Al2O3) or AlN can be used. The materials are not limited to these, but at least the bottom portion 118 has better heat dissipation than the frame portion 111, and the bottom portion 118 has a higher thermal conductivity than the frame portion 111.

[0019] The bottom portion 118 has a shape in which the four corners of a rectangle are rounded on the joint surface that joins with the substrate 100 and on the placement surface where the light reflecting member 150, the submount 160, and the semiconductor laser element 170 are arranged. Also, the thickness from the joint surface to the placement surface is uniform. In the present invention, a shape in which processing such as rounding, chamfering, corner rounding, or rounding is performed at the corners of a rectangle is also referred to as a rectangle. Similarly, for example, a shape in which processing such as corner rounding is performed on one or more corners of a polygon is also referred to as a polygon. Also, for each side of a rectangle or polygon, when the corner is processed, the processed portion is also regarded as a side. Note that the joint surface that joins with the substrate 100 is regarded as the bottom surface. The shapes of the bottom surface and the placement surface are not limited to this.

[0020] The frame portion 111 has a first electrode layer 112 on the bottom surface which is the surface that joins with the substrate 100. The first electrode layer 112 is composed of, for example, a metal layer and joins with the metal film 103 of the substrate 100. Electric power is supplied to the semiconductor laser element 170 via the metal film 103. Also, the frame portion 111 has a stepped portion inside the frame, and the plane on the bottom surface side of this stepped portion becomes the joint surface 113 with the bottom portion 118. For the sake of convenience, regarding two opposing planes, the side closer to the substrate 100 is called the lower surface, and the opposite side is called the upper surface. Alternatively, the side closer to the lens member 140 is called the upper surface, and the opposite side is called the lower surface. The frame portion 111 in FIG. 4A is arranged with the upper surface and the lower surface turned over.

[0021] FIG. 4E is a top view of the frame portion 111, and FIG. 4F is a bottom view of the frame portion 111. The frame portion 111 has a joint surface 113 on the stepped portion plane as 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 as viewed from the top. The second electrode layer 114 is electrically connected to the first electrode layer 112 via, for example, a via hole. The second electrode layer 114 is composed of, for example, a metal layer and is disposed on the ceramic layer, so it is not exposed on the lower surface of the stepped portion. Also, in the bottom view, the stepped portion forms all four sides of the frame, while in the top view, the stepped portion is provided only along three sides of the frame, and for the remaining one side, it is not provided except for the end portions that overlap with the two sides at both ends. That is, the region having the stepped portion is different when viewed from the top and when viewed from the bottom. The joint surface 113 in the stepped portion joins with the bottom portion 118, so the stepped portion as viewed from the bottom is provided over the entire circumference. On the other hand, since it is only necessary to secure a region for providing the second electrode layer on the stepped portion plane as viewed from the top, it does not necessarily have to be provided over the entire circumference.

[0022] Also, for the side opposite to the side where the second electrode layer 114 is not provided, the width of the joint surface 113 is larger than that of the other sides. On the other hand, the width of the joint surface of the frame portion 111 that joins with the substrate 100 is designed to be the same for the side where the second electrode layer 114 is not provided and the side opposite to that side. In other words, the shortest distance between the two side surfaces that intersect with the joint surface of the frame portion 111 and the substrate 100 is made equal for the corresponding positions on the opposite sides. Note that "equal" means a relationship in which, for two or more values to be compared, the difference between those values falls within the range of error due to design intersection. By doing so, it is possible to balance the force applied to the base portion 110 when joining with the substrate 100 by soldering. Note that the corresponding positions on the opposite sides refer to, in the case where the two opposite sides are in a parallel relationship, a certain position on one side and the position on the other side that is the shortest distance from that position.

[0023] Next, as shown in FIG. 5A, the joint surface 113 of the frame portion 111 and the bottom portion 118 are joined. For the joining, for example, a silver solder mainly composed of Ag and containing Cu can be used, but other metal solders can also be utilized. As shown in FIG. 4A, with the bottom surface of the frame portion 111 that joins to the substrate 100 facing upward, silver solder is applied to the joint surface. In a state where the silver solder has melted due to heating, the bottom portion 118 is fitted into the frame of the frame portion 111. Then, the silver solder is cooled to join the frame portion 111 and the bottom portion 118, thereby forming the base portion 110. Note that silver solder is applied in a state where Ni plating is applied to the joint region between the frame portion 111 and the bottom portion 118.

[0024] Therefore, as shown in FIGS. 5B and 5C, the size of the joint surface of the bottom portion 118 that joins to the frame portion 111 is smaller than the frame formed by the inner surface 115 that intersects the bottom surface of the frame portion 111 and is in an enclosed form. Furthermore, the shapes of the inner surface 115 of the frame portion 111 and the side surface 119 of the bottom portion 118 are designed such that the placement surface of the bottom portion 118 joins to the joint surface 113 at the step portion of the frame portion 111. In the light-emitting device 1 according to the first embodiment, the length from the bottom surface of the frame portion 111 to the joint surface 113 and the height of the bottom portion 118 are designed to be aligned, and the bottom portion 118 is sized to fit within the frame formed by the inner surface 115 that intersects the joint surface 113.

[0025] In addition, a gap is formed between the inner surface 115 and the side surface 119. As described above, the frame portion 111 can be formed of ceramic, but the degree of sintering during manufacturing is not always the same. For this reason, differences may occur in the shape and size between the manufactured frame portions 111. In the manufacture of the light-emitting device 1, considering the design intersection, the shapes of the frame portion 111 and the bottom portion 118 are designed so that a gap of about 0.1 mm can be formed between the frame portion 111 and the bottom portion 118. Note that it may be designed to provide a gap of 0.1 mm or more, or it may be designed to provide a gap of 0.1 mm or less. Preferably, the gap is set to be from 0.1 mm to 0.5 mm. Thereby, the bottom portion 118 can be appropriately joined to the joint surface of the frame portion 111, and the heat dissipation property of the bottom portion 118 can be improved, so that the base portion 110 having excellent heat dissipation property can be formed.

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

[0027] In addition, regarding the relationship between the frame formed by the inner surface 115 at the inner end of the bottom surface of the frame portion 111 and the frame formed by the inner surface 117 at the inner end of the upper surface of the frame portion 111, when viewed in the S1 direction, the inner surface 115 is larger than the inner surface 117, and when viewed in the S2 direction, the sizes of the inner surfaces 115 and 117 are equal. The S1 direction is a side that does not have a stepped portion for the second electrode layer in the top view, and the lower surface is larger than the upper surface to form a joint surface with respect to this side. In the S2 direction, since both sides have stepped portions for the second electrode layer, a joint surface can be formed using these stepped portions, so it is not necessary to enlarge the lower surface side.

[0028] On both sides of the frame portion 111 when viewed from the S2 direction, the first electrode layer is provided on the bottom surface thereof. From the perspective of heat dissipation, it can be said that a larger bottom portion 118 is desirable. However, if the width of the bottom surface becomes narrow, there is a concern that when soldering, the solder may come into contact with both the first electrode layer and the bottom portion 118, or may be electrically connected. When viewed in the S2 direction, the inner surfaces 115 and 117 do not have to be aligned, but the size of the inner surface 115 is provided at a position ensuring a predetermined distance from the first electrode layer. Preferably, with respect to the first electrode layer having a width of about 0.5 mm, a space of about 0.3 mm is provided, and the position of the inner end on the bottom surface is preferably determined. The first electrode layer 112 and the second electrode layer 114 are electrically connected through a conduction portion provided inside the frame portion 111.

[0029] Here, a supplement is made regarding the determination of the structure of the frame portion 111 and the bottom portion 118. From the perspective of heat dissipation, since heat is desired to diffuse from the position where the semiconductor laser element 170, which is the main heat source, is arranged, a material with good heat dissipation is desired for the bottom portion 118. Therefore, a metal such as Cu is preferable to ceramic. Also, it is better to have a certain size, and the portion exposed as the placement surface is preferably metal. Furthermore, in order to bond with the substrate 100 and efficiently release heat from there to the substrate 100, it is preferable that no material with poor heat dissipation is sandwiched between the placement surface and the bonding surface with the substrate 100.

[0030] Also, from the perspective of the strength aspect and the shape stability when the light-emitting device 1 is used, the outer frame of the base is preferably ceramic. Furthermore, in order to provide a metal layer for electrically connecting the semiconductor laser element, it is necessary to provide a step on a part of the ceramic frame. Therefore, the base 110 in the light-emitting device 1 needs to include at least a frame surrounding the periphery, a bottom portion for arranging the semiconductor laser, and a step for providing a metal layer.

[0031] Note that the step does not need to be provided around the entire circumference of the frame. Depending on the number of semiconductor laser elements 170 arranged in the light-emitting device 1, the combination when arranging a plurality of semiconductor laser elements 170, etc., the area where the stepped portion is provided can be adjusted as appropriate. For example, it may be sufficient to provide it along one side or two sides of the frame, or it may be necessary to provide it around the entire circumference. Note that the combination when arranging a plurality of semiconductor laser elements 170 means, for example, whether to arrange a plurality of semiconductor laser elements of the same color and the same performance, or to arrange semiconductor laser elements of different colors, etc.

[0032] In consideration of these, the frame portion 111 and the bottom portion 118 in the light-emitting device 1 are such that the frame portion 111 is formed of ceramic while the bottom portion 118 employs metal, and the boundary between the frame portion and the bottom portion is defined to improve heat dissipation. Furthermore, a gap is provided in consideration of the design intersection by ceramic. Therefore, a base portion 110 with better heat dissipation can be provided than when the arrangement surface of the base portion 110 where the semiconductor laser element 170 is arranged is formed of ceramic.

[0033] In FIG. 6A, a light reflection member 150 and a submount 160 on which the semiconductor laser element 170 is arranged are joined to the formed arrangement surface of the base portion 110. Note that the positions where the light reflection member 150 and the submount 160 are arranged are determined based on the frame portion 111, not the position based on the bottom portion 118. That is, the light reflection member 150 and the submount 160 are arranged such that the distances and coordinates from a specific position of the frame portion 111 match, rather than the distances and coordinates from a specific position of the bottom portion 118.

[0034] As described above, since a gap is formed between the frame portion 111 and the bottom portion 118, the bottom portion 118 is not fixed by the frame formed by the frame portion 111. Therefore, the bottom portion 118 may move when joining by soldering. For example, in the light-emitting device 1, the shape of the frame of the frame portion 111 and the shape of the joint surface of the bottom portion 118 are in a similar relationship, but as a result of joining, the center points of each may not coincide, or the distances from the frame portion 111 to the bottom portion 118 may not be uniform. Therefore, even when the bottom portion 118 is displaced, it is preferable to adjust the arrangement position so that the positions with respect to the frame portion 111 are aligned so that alignment between the manufactured light-emitting devices 1 is easy. Note that the smaller the gap between the frame portion 111 and the bottom portion 118 described above, the smaller the displacement due to movement.

[0035] The light reflecting member 150 has a light reflecting surface on at least one surface. Since the light reflecting member 150 receives the emitted light from the semiconductor laser element 170, it is desirable to use a material that is resistant to heat as the main material and a material with a high reflectance for the light reflecting surface. As the main material, glass such as quartz or BK7 (borosilicate glass), a metal such as aluminum, or Si or the like can be adopted, and a metal or a dielectric multilayer film or the like can be adopted as the light reflecting surface. Note that the light-emitting device 1 may be a light reflecting member 150 having a plurality of light reflecting surfaces as necessary, or may have a light reflecting member other than the light reflecting member 150. In addition, although one light reflecting member 150 is provided according to each semiconductor laser element 170, one light reflecting member 150 may be arranged for three semiconductor laser elements 170, or one light reflecting member may be provided for a plurality of semiconductor laser elements.

[0036] As the submount 160, aluminum nitride or silicon carbide can be used. In addition, 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 joined 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 face, where the length of the stacked direction of the plurality of semiconductor layers including the active layer is longer than the length in the direction perpendicular thereto. The FFP here refers to the measurement of the light intensity distribution of the emitted light in a plane that is at a certain distance from the light emitting end face of the semiconductor laser element and parallel to the light emitting end face. The shape of the FFP is specified as the shape by the main part of the light. Here, the main part of the light by the laser element refers to the part in the intensity range from the peak intensity value of the laser light to the point where it drops to an arbitrary intensity such as 1 / e 2 and so on.

[0038] The light emitting device 1 has one or more semiconductor laser elements 170, and as shown in FIGS. 6A to 6C, three semiconductor laser elements 170 are arranged. The number of semiconductor laser elements 170 to be arranged is not limited to this and may be one or more. Also, the light emitted from these semiconductor laser elements 170 may be of the same color or different colors. For example, the three semiconductor laser elements 170 included in the light emitting device 1 can 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, respectively.

[0039] The emission peak wavelength of red light is, for example, in the range of 605 nm to 750 nm. Examples of semiconductor laser elements that emit red light include those containing semiconductors such as 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. As the nitride semiconductor, for example, GaN, InGaN, and AlGaN can be used.

[0040] In FIG. 7A, the wire is joined 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, using a wire bonding apparatus, one end of an Au wire is joined to the semiconductor laser element 170 and the other end is joined to the second electrode layer 114. When a protective element such as a Zener diode is arranged on the submount 160, the protective element is also electrically connected by the wire 180.

[0041] As shown in FIGS. 6A and 6B, the stepped portion for providing the second electrode layer 114 is provided across three sides in a top view, and is not provided on one side except for the overlapping portion with the other side. That one side is the side where the light reflecting member 150 exists between the semiconductor laser element 170 or the submount 160 and that side, and is the side located on the opposite side of the semiconductor laser element 170 with the light reflecting member 150 interposed therebetween. The light emitted from the semiconductor laser element 170 is reflected through the light reflecting member 150 and travels upward. As is also apparent from FIGS. 7A and 7B, if a stepped portion is provided on that one side to electrically connect the second electrode layer 114 on that side and the semiconductor laser element 170 with a wire, the wire will exist in the traveling direction of the light and block the light. Therefore, for the side on the light reflecting member 150 side, by not providing the stepped portion for the second electrode layer 114, the second electrode layer 114 can be appropriately arranged, contributing to the miniaturization of the size of the light emitting device 1.

[0042] In FIG. 8A, the frame portion 111 of the base portion 110 and the lid portion 120 are joined, and the space where the semiconductor laser element 170 is arranged is hermetically sealed. For example, on the lower surface of the lid portion 120, a metal film is provided in the region joined to the base portion 110, and the base portion 110 and the lid portion 120 are joined and fixed via AuSn or the like. Since the semiconductor laser element 170 is arranged in this closed space, it is possible to suppress dust collection of organic substances or the like on the light emitting end face of the semiconductor laser element 170.

[0043] As the lid portion 120, for example, a glass provided with a metal film or a sapphire provided with a metal film can be used, and among them, it is preferable to use a sapphire provided with a metal film. When light spreads, the shape of the lens portion that allows the light to pass through becomes larger. However, since sapphire has a relatively high refractive index and can suppress the spread of light, the size of the lens portion of the lens member 140 can be suppressed. In addition, since it has relatively high strength and is difficult to break, the airtight reliability of the closed space can be ensured.

[0044] In FIG. 9A, the base portion 110 is mounted on the substrate 100. The substrate 100 is joined to the bottom surfaces of the frame portion 111 and the bottom portion 118 of the base portion 110. The joining 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 in the same manner as the heat dissipation portion 101.

[0045] The heat dissipation portion 101 is joined to the bottom portion 118 of the base portion 110, and the metal film 103 or the insulating portion 102 is joined to the frame portion 111. Therefore, the substrate 100 is designed so that the metal film 103 and the heat dissipation portion 101 are provided in the same plane. Specifically, the heat dissipation portion 101 has a convex structure protruding to the side of the base portion 110 in a cross-sectional view or a side view, and is shaped so as to be exposed in a region joined to the bottom portion 118 of the base portion 110. On the other hand, in the region where the substrate 100 is joined to the frame portion 111, the heat dissipation portion 101 does not protrude, and the insulating portion 102 is disposed on the heat dissipation portion 101. In addition, in the joining region of the substrate 100 corresponding to the side having the first electrode layer 112 of the frame portion 111, the metal film 103 is provided on the insulating portion 102. Further, the heat dissipation portion 101 and the metal film 103 do not contact each other, and a predetermined interval is provided so as not to be electrically connected. A part of the region where this predetermined interval is provided overlaps with a part of the gap between the frame portion 111 and the bottom portion 118.

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

[0047] The shape of the exposed portion 106 represents the region where the heat dissipation portion 101 protrudes. Also, this shape is matched to the shape of the bottom surface of the bottom portion 118 and is designed to be slightly larger. If they are the same size, during soldering, the solder cannot escape outside the bonding surface, and an extra thickness will be formed between the substrate 100 and the base portion 110. Also, the side of the metal region 104 closer to the center of the substrate 100 across the insulating region 105 joins with the frame portion 111. By this joining, the metal region 104 and the first electrode layer 112 are electrically connected.

[0048] In this way, by making the heights of the metal film 103 provided with the insulating portion 102 therebetween and the exposed portion 106 of the heat dissipation portion 101 uniform, it is possible to reduce the floating that may occur between the frame portion 111 or the bottom portion 118 during bonding to the base portion 110. If the floating becomes large, the bonding force becomes weak, or a region that is not joined partially is formed, so the possibility that the package comes off the mounting substrate becomes high. Also, by joining the entire bottom surface of the bottom portion 118 with the exposed portion 106 of the heat dissipation portion 101, heat can be efficiently dissipated to the substrate 100.

[0049] In FIG. 10A, the lens member 140 is adhered to the lid portion 120 using an adhesive. Through this adhesion process, an adhesive portion 130 is formed between the lid portion 120 and the lens member 140, and the light-emitting device 1 shown in FIGS. 1 to 3 is manufactured. The adhesive portion 130 is not formed over the entire upper surface of the lid portion 120 or the entire lower surface of the lens member 140, and is provided at a position that does not obstruct the path of light emitted from the semiconductor laser element 170. Specifically, in the light-emitting device 1, the main portion of the light emitted by the semiconductor laser element 170 enters and exits from a region having the lens shape of the lens member 140. Therefore, it is desirable that the adhesive portion 130 is not formed on the lower surface of the lens member 140 corresponding to the region having the lens shape, but is formed in the outer edge region of the lens member 140. As the adhesive for forming the adhesive portion 130, it is preferable to use an ultraviolet-curable resin. Since the ultraviolet-curable resin can be cured in a relatively short time without heating, it is easy to fix the lens member 140 at a desired position.

[0050] As shown in FIGS. 10B and 10C, the lens member 140 has a lens shape in which a plurality of lens portions are connected. Also, one lens portion corresponds to one semiconductor laser element, and each lens portion is designed to allow the main portion of the light emitted from a different semiconductor laser element to pass through. For the lens member 140, for example, glass such as BK7 or B270 can be used.

[0051] In the above manner, the light-emitting device 1 according to the first embodiment is manufactured. Note that the process of manufacturing the light-emitting device 1 is not limited to the processes described with reference to FIGS. 4A to 10A.

[0052] <Second Embodiment> FIG. 11 shows a cross-sectional view of the light-emitting device 2 according to the second embodiment. Note that the schematic diagram of the appearance of the light-emitting device 2 is the same as that of FIG. 1, and the internal structure in a top view is also the same as that of FIG. 2. The light-emitting device 2 according to the second embodiment has a different structure of the bottom portion that constitutes the base portion as compared with the light-emitting device 1 according to the first embodiment. In particular, the bonding surface of the bottom portion that is bonded to the substrate is different from that of the first embodiment. If the shapes of the insulating portion and the exposed portion on the bonding surface of the substrate are made to correspond to this, for other points, the structures, materials, etc. described in the first embodiment can be adopted.

[0053] Although it was described in the process according to FIG. 5A of the light-emitting device 1 of the first embodiment, when joining the frame portion 111 and the bottom portion 118, it is desirable that the bottom portion 118 be arranged so that the distances from the frame portion 111 are all uniform. However, it is conceivable that it may shift during the joining process. At this time, if the shift becomes large, a part of the bottom portion 118 comes into contact with the frame portion 111. In addition, 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. When the frame portion 111, the bottom portion 118, and the substrate 100 are joined by soldering and the first electrode layer 112 and the bottom portion 118 are electrically connected, it leads to a defect in the light-emitting device.

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

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

[0056] The recessed portion 214 only needs to ensure a sufficient interval and height so that the above-described defects do not occur in the soldering process with the substrate 200. For example, the light-emitting device 1 of the first embodiment is designed with an interval of about 0.1 mm, but if it is only necessary to provide an interval of at least about 0.1 mm, the width of the recess can be designed to be about 0.1 mm. In this way, even if the frame portion 211 and the bottom portion 213 are in contact with each other at the bonding surface 212 with the frame portion 211, the interval between the frame portion 211 and the bottom portion 213 at the bonding surface with the substrate 200 can be maintained at about 0.1 mm. Also, for example, the light-emitting device 1 of the first embodiment is designed such that the distance from the side surface 119 of the bottom portion 118 to the first electrode layer 112 is 0.3 mm or more. When designing the width of the recess, similarly, it may be determined in consideration of the design of the frame portion so that the distance to the first electrode layer 112 is maintained at about 0.3 mm. Note that the interval of 0.3 mm shows an example of the design in the light-emitting device 1, and the predetermined interval to be provided may be appropriately determined from the shape and material of the light-emitting device.

[0057] Therefore, it is preferable to provide the recessed portion 214 so as to have a width approximately the same as the gap to be ensured when the bottom portion 213 has no recessed portion 214 and there is no displacement with respect to the frame portion 211. Note that the recessed portion 214 may have a width greater than this, or the protruding region described in FIG. 12 may have a shape in which a part thereof has a width greater than that of the circular bottom portion 213. However, since an increase in the width of the recess also means a decrease in the bonding area with the substrate 200, it is desirable not to increase the width of the recessed portion more than necessary to obtain sufficient bonding, and the width is preferably from 0.1 mm to 0.5 mm. For example, when providing a circular bonding surface as shown in FIG. 12, it is conceivable to design it so as to have a width approximately the same as the gap to be ensured at the position where the width of the recess is the narrowest.

[0058] Regarding the height ensured by the recessed portion 214, it is sufficient that the solder protruding from the bonding surface 215 of the bottom portion 213 with the substrate 200 rises along the side surface intersecting the bonding surface 215 with the substrate 200 and is ensured to have a height that stays within the recess. The desirable height to be ensured varies depending on the material and amount of the solder used for bonding. For example, in the light-emitting device 2, a height of about 0.2 mm is ensured.

[0059] In addition, when the bonding surface with the substrate has a shape such as the four corners of a rectangle or a square being processed, like the bottom portion 118 described in the light-emitting device 1 or the bottom portion 213 described as an example in FIG. 12, the exposed portion on the substrate side is also provided in a shape corresponding to this, and self-alignment works when bonding the bottom portion to the substrate.

[0060] On the other hand, when the joint surface with the substrate 200 is circular as in the bottom portion 213 described as an example in FIG. 12, the exposed portion 201 on the substrate side is also provided in a circular shape accordingly. Thus, the joint surface of the bottom portion 213 fits within the exposed portion 201. Even when the substrate 200 and the bottom portion 213 are in contact via solder, they have mobility in the direction of rotating the circle until the solder solidifies. As described above, when a deviation occurs in the arrangement of the frame portion 211 and the bottom portion 213, by making the joint surface 215 with the substrate 200 circular, adjustment in the rotational direction can be achieved, and the deviation of the frame portion 211 with respect to the substrate 200 can be corrected.

[0061] ≪First Modified Example≫ The light-emitting device 3 of the first modified example realizes a light-emitting device in which the distance between the frame portion and the bottom portion on the joint surface with the substrate is wider than the distance between the frame portion and the bottom portion on the joint surface with the frame portion, by a method different from the light-emitting device 2 shown in the second embodiment.

[0062] FIG. 14 shows a cross-sectional view of the light-emitting device 3 according to the first modified example. As shown in FIG. 14, the light-emitting device 3 has a recessed portion 312 in the frame portion 311, thereby making the distance between the frame portion 311 and the bottom portion 313 on the joint surface with the substrate 300 wider than the distance between the frame portion 311 and the bottom portion 313 on the joint surface with the frame portion 311. In this way, it may be realized by a method of processing the shape of the frame portion 311. In the light-emitting device 3, unlike the light-emitting device 2, the substrate 100 of the first embodiment can be adopted as it is.

[0063] ≪Second Modified Example≫ FIG. 15 shows a cross-sectional view of the light-emitting device 4 according to the second modified example. FIG. 16 shows a schematic view of the bottom portion according to the second modified example. As shown in FIG. 15, in the light-emitting device 4, at the bottom portion 412, the joint surface with the substrate 400 is smaller than the joint surface with the frame portion 411, and the side surface 413 has an inclination. By providing such an inclination on the side surface 413, the distance between the frame portion 411 and the bottom portion 412 on the joint surface with the substrate 400 can be made wider than the distance between the frame portion 411 and the bottom portion 412 on the joint surface with the frame portion 411. Note that, similar to the first modified example, instead of providing an inclination on the bottom portion 412, it may be provided on the frame portion 411.

[0064] As described above, the light-emitting device according to the present invention has been described based on each embodiment and modification example. However, the light-emitting device that realizes the technical idea of the present invention is not limited thereto. For example, although a light-emitting device in which three semiconductor laser elements are arranged has been described, a light-emitting device in which one or a plurality of semiconductor laser elements are arranged may be used. Further, a light-emitting device that does not have the light reflection member 150 and in which the light emitted from the semiconductor laser element travels in the direction of the lens member 140 may be used.

[0065] Further, the light-emitting device having the technical features disclosed by the present invention is not necessarily limited to the structures of the light-emitting devices 1 to 4. For example, the present invention can be applied to a light-emitting device having components not disclosed in any of the light-emitting devices, and the fact that there are differences from the disclosed light-emitting devices is not a basis for not being able to apply the present invention.

[0066] On the other hand, the present invention can be applied even if it is not essential to sufficiently provide all the components of the light-emitting device disclosed by each embodiment and modification example. For example, when some components of the light-emitting device disclosed by the first embodiment are not described in the claims, for those components, it is not limited to those disclosed in the present embodiment, and the design freedom of those skilled in the art such as substitution, omission, shape modification, material change, etc. is recognized, and it is claimed that the invention described in the claims is applicable thereon.

Industrial Applicability

[0067] The light-emitting device described in each embodiment can be used for projectors, in-vehicle headlights, lighting, backlights for displays, etc.

Explanation of Reference Numerals

[0068] 1... Light-emitting device 100... Substrate 101... Heat dissipation part 102... Insulating part 103... Metal film 104... Metal region 105... Insulating region 106…Exposed part 110…Base part 111…Frame part 112…First electrode layer 113…Bonding surface 114…Second electrode layer 115…Inner surface 116…Inner surface 117…Inner surface 118…Bottom part 119…Side surface 120…Cover part 130…Adhesive part 140…Lens member 150…Light reflection member 160…Submount 170…Semiconductor laser element 180…Wire 2…Light emitting device 200…Substrate 201…Exposed part 210…Base part 211…Frame part 212…Bonding surface 213…Bottom part 214…Depressed part 215…Bonding surface 3…Light emitting device 300…Substrate 310…Base part 311…Frame part 312…Depressed part 313…Bottom part 4…Light emitting device 400…Substrate 410…Base part 411…Frame part 412…Bottom part 413…Side surface

Claims

1. A semiconductor laser element, a base having a bottom made mainly of metal and a frame portion having an upper surface located above the bottom, a first electrode layer provided on the frame portion, and a second electrode layer provided on the frame portion and electrically connected to the first electrode layer, a light reflecting member, a plurality of wires electrically connected to the semiconductor laser element, comprising: wherein the semiconductor laser element and the light reflecting member are arranged side by side in a first direction within a space surrounded by the bottom and the frame portion; the second electrode layer is provided so as to be exposed from the frame portion within the space; the plurality of wires are joined to the second electrode layer; when a virtual straight line extending in a direction intersecting the first direction in a top view divides the space between the semiconductor laser element and the light reflecting member, if the space containing the semiconductor laser element is defined as a first region and the space containing the light reflecting member is defined as a second region, the joining points where the plurality of wires are joined to the second electrode layer are located side by side within the first region, a light emitting device.

2. The light emitting device according to claim 1, wherein only one semiconductor laser element is arranged within the space.

3. The light emitting device according to claim 1, wherein a plurality of semiconductor laser elements are arranged within the space.

4. the frame portion has a first inner surface forming a frame in which the bottom is received and a second inner surface forming a frame covered by the bottom; the frame portion and the bottom are arranged such that in a bottom view, the bottom is received within the first inner surface and in a top view, the bottom covers the frame formed by the second inner surface, the light emitting device according to any one of claims 1 to 3.

5. The second electrode layer is provided on a stepped surface of the frame portion, and the frame portion is joined to the bottom directly below the region where the second electrode layer is arranged, the light emitting device according to any one of claims 1 to 4.

6. The first electrode layer is provided on the lower surface of the frame portion, the light emitting device according to any one of claims 1 to 5.

7. The light emitting device according to any one of claims 1 to 6, further comprising a substrate on which the base is mounted.

8. a base having a bottom made mainly of metal and a frame portion having an upper surface located above the bottom, a first electrode layer provided on the frame portion, and a second electrode layer provided on the frame portion and electrically connected to the first electrode layer, comprising: In a space surrounded by the bottom portion and the frame portion, there is a region where a semiconductor laser element and a light reflecting member are arranged side by side in a first direction. The second electrode layer is provided so as to be exposed from the frame portion within the space. In the second electrode layer, a region is secured to which a plurality of wires electrically connected to the semiconductor laser element are joined. When the space is divided in a top view by a virtual straight line extending in a direction intersecting the first direction into a region where the semiconductor laser element is arranged and a region where the light reflecting member is arranged, if the region where the semiconductor laser element is arranged is defined as a first region and the region where the light reflecting member is arranged is defined as a second region, the joining points where the plurality of wires are joined to the second electrode layer are located within the first region side by side in the first direction. Base.

9. The base according to claim 8, wherein only one semiconductor laser element is arranged in the space.

10. The base according to claim 8, wherein a plurality of the semiconductor laser elements are arranged in the space.

11. The frame portion has a first inner surface forming a frame in which the bottom portion fits, and a second inner surface forming a frame covered by the bottom portion. The base according to any one of claims 8 to 10, wherein the frame portion and the bottom portion are arranged such that the bottom portion fits into the first inner surface in a bottom view and the bottom portion covers the frame formed by the second inner surface in a top view.

12. The base according to any one of claims 8 to 11, wherein the second electrode layer is provided on a stepped surface of the frame portion, and the frame portion is joined to the bottom portion directly below the region where the second electrode layer is arranged.

13. The base according to any one of claims 8 to 12, wherein the first electrode layer is provided on the lower surface of the frame portion.

14. The base according to any one of claims 8 to 13, wherein the second electrode layer is located in a direction perpendicular to the first direction passing through the region where the semiconductor laser element is arranged in a top view.

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