Light-emitting device

Abstract

To achieve a package that suppresses cracking, breakage, and delamination on a light-emitting device.SOLUTION: A light-emitting device has a base part and a frame part. The base part has a light-emitting element, a first surface on which the light-emitting element is arranged, and a convex part formed on a side of the first surface outside of an area on which the light-emitting element is arranged. The frame part is made of a material as a main material having a coefficient of thermal expansion different from that of the main material used on the base part. The frame part has a bonding surface to be bonded to a protruding upper surface of the convex part of the base part and surrounds the light-emitting element arranged on the first surface.SELECTED DRAWING: Figure 9

Description

[Technical field]

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

[0002] Conventionally, light-emitting devices have been known in which a light-emitting element such as an LED element or a semiconductor laser element is arranged in a package having a frame and a bottom surface. For example, Patent Document 1 discloses a package for housing a semiconductor element, which is configured to have a ceramic laminate and a heat dissipation member made of a metal material. In addition, a lid is joined to the package for housing a semiconductor element with the semiconductor element arranged on the heat dissipation member, thereby manufacturing a semiconductor device housing the semiconductor element.

[0003] As described in Patent Document 1, when a semiconductor element operates, heat is generated. The heat also affects the package for housing the semiconductor element that constitutes the semiconductor device. Generally, ceramics and metals have different thermal expansion coefficients and material strengths. In addition, the material properties such as resistance to cracking and bending are also different. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2014 / 017273 Summary of the Invention [Problem to be solved by the invention]

[0005] As exemplified in Patent Document 1, when forming a package by joining components made of different materials, it is necessary to take into consideration the size of the package and the shape of each component, etc., to prevent the occurrence of cracks, breakage, peeling, etc. [Means for solving the problem]

[0006] The light emitting device disclosed in the present application comprises a base having a light emitting element, a first surface on which the light emitting element is arranged, and a convex portion formed on the side of the first surface outside the area in which the light emitting element is arranged, and a frame portion made mainly of a material having a thermal expansion coefficient different from that of a main material used for the base, having a bonding surface that bonds with the protruding upper surface of the convex portion of the base, and surrounding the light emitting element arranged on the first surface.

[0007] The package disclosed in the present application has a cavity surrounding a light-emitting element, and includes a base having a first surface on which the light-emitting element is arranged and a convex portion formed outside the area in which the light-emitting element is arranged on the side of the first surface, and a frame having an outer surface, a first upper surface and a first lower surface intersecting the outer surface, and a second lower surface formed between the first upper surface and the first lower surface, wherein the main materials forming the base and the frame have different thermal expansion coefficients, and the protruding upper surface of the convex portion is joined to the second lower surface of the frame.

[0008] The base disclosed in the present application is a base that is joined to a frame having an outer surface, a first upper surface and a first lower surface intersecting the outer surface, and a second lower surface formed between the first upper surface and the first lower surface, and forms a cavity surrounding a light-emitting element, the base having a first surface on which the light-emitting element is arranged, and a convex portion formed outside the area in which the light-emitting element is arranged on the side of the first surface, and made mainly of a material having a thermal expansion coefficient different from that of a main material used for the frame, and the protruding upper surface of the convex portion is joined to the second lower surface of the frame. Effect of the Invention

[0009] According to the present invention, it is possible to provide a light emitting device that is mounted using a package formed by bonding different materials and in which the occurrence of cracking, breakage, peeling, and the like is suppressed.

[0010] Furthermore, according to the present invention, it is possible to provide a package in which the occurrence of cracking, breakage, peeling, etc. is suppressed, or a base suitable for forming such a package. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a light emitting device including a mounting substrate according to the first embodiment. [Diagram 2] FIG. 2 is a perspective view of the light emitting device according to the first embodiment. [Diagram 3] FIG. 3 is a perspective view of the light emitting device according to the first embodiment, with a part of the configuration removed, seen from the same direction as FIG. [Figure 4] FIG. 4 is a top view of the light emitting device according to the first embodiment, corresponding to FIG. [Diagram 5] FIG. 5 is a perspective view of the frame of the light emitting device according to the first embodiment, seen from above. [Figure 6] FIG. 6 is a perspective view of the frame of the light emitting device according to the first embodiment, viewed from the bottom side. [Figure 7] FIG. 7 is a perspective view of the base of the light emitting device according to the first embodiment, as viewed from above. [Figure 8] FIG. 8 is a top view of the light emitting device according to the first embodiment, showing a state in which the base and the frame are joined together. [Figure 9] FIG. 9 is a cross-sectional view of the base and frame joined together along a line connecting IX-IX in FIG. [Figure 10] FIG. 10 is a cross-sectional view of the base and frame joined together along the line connecting XX in FIG. [Figure 11] FIG. 11 is a cross-sectional view of the light emitting device according to the second embodiment in a state where the base and the frame are joined together. [Figure 12] FIG. 12 is a cross-sectional view of the light emitting device according to the third embodiment in a state where the base and the frame are joined together. [Figure 13] FIG. 13 is a cross-sectional view of the light emitting device according to the fourth embodiment in a state where the base and the frame are joined together. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In this specification and claims, polygons such as triangles and quadrangles are referred to as polygons, including shapes in which the corners of the polygons have been processed, such as by rounding, chamfering, removing the corners, or rounding off the edges. In addition, shapes in which processing has been applied to the middle parts of the sides, not just the corners (edges), are also referred to as polygons. In other words, shapes that have been processed based on a polygon are included in the interpretation of "polygon" described in this specification and claims.

[0013] This is not limited to polygons, but also applies to words expressing specific shapes such as trapezoids, circles, and irregular shapes. The same is true when dealing with each side that forms the shape. In other words, even if the corners or middle part of a side have been processed, the interpretation of "side" includes the processed part. Note that when distinguishing "polygons" or "sides" that have not been intentionally processed from processed shapes, the word "strict" is added, for example, "strict quadrangle."

[0014] Hereinafter, a description will be given of an embodiment of the present invention with reference to the drawings. However, the embodiment shown is an embodiment of the technical idea of ​​the present invention, but does not limit the present invention. In the following description, the same names and symbols indicate the same or similar components, and duplicated descriptions may be omitted as appropriate. The sizes and positional relationships of the components shown in each drawing may be exaggerated to clarify the description.

[0015] First Embodiment FIG. 1 is a perspective view of a state in which a light emitting device 1 and a substrate 2 according to the first embodiment are joined together. FIG. 2 is a perspective view of the light emitting device 1. FIG. 3 is a perspective view for explaining the internal structure of the light emitting device 1. FIG. 4 is a top view for explaining the internal structure of the light emitting device 1. FIG. 5 is a perspective view of the upper surface side of a frame portion 20 in the light emitting device 1. FIG. 6 is a perspective view of the lower surface side of the frame portion 20 in the light emitting device 1. FIG. 7 is a perspective view of the upper surface side of the bottom of the light emitting device 1. FIG. 8 is a top view of a base portion 10 and a frame portion 20 in the light emitting device 1. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. FIG. 10 is a cross-sectional view taken along line XX in FIG. 8.

[0016] The light emitting device 1 has, as its components, a base 10, a frame 20, three semiconductor laser elements 30, three submounts 40, three light reflecting members 50, a protective element 70, and a lid member 80. The light emitting device 1 is bonded to a substrate 2.

[0017] As shown in Fig. 7, the base 10 has a shape in which a convex portion 104 is provided near the outer periphery of the flat upper surface. The base 10 also has a first surface 101 corresponding to the upper surface, a second surface 102 corresponding to the lower surface, an outer surface 103, and the convex portion 104. The first surface 101 is located on the opposite side of the second surface 102 and is in a position that is not directly visible from the top view of Fig. 7. The outer surface 103 intersects with the first surface 101 and the second surface 102. The convex portion 104 is provided on the first surface 101 side near the periphery where the first surface 101 and the outer surface 103 intersect.

[0018] The protruding portion of the protruding portion 104 has a convex outer side surface 106 which is an outer side surface forming the protruding portion, a convex inner side surface 107 which is an inner side surface forming the protruding portion, and a convex upper surface 105 which is an upper surface forming the protruding upper surface of the protruding portion and intersecting with the convex outer side surface 106 and the convex inner side surface 107. The protruding portion 104 protrudes upward on the first surface 101 side at a position spaced from the position where it intersects with the outer side surface 103, and the convex upper surface 105 is formed from the protruding position toward the inside. In other words, the convex outer side surface 106 is formed inside the outer side surface 103 of the base 10.

[0019] The height of the convex portion 104, in other words, the height from the first surface 101 of the base 10 to the convex upper surface 105, is smaller than the thickness from the second surface 102 to the first surface 101 of the base 10. For example, the thickness from the second surface 102 to the first surface 101 of the base 10 is formed in the range of 0.2 mm to 1.0 mm, and the height of the convex portion 104 is formed in the range of 0.2 mm to 0.5 mm. Preferably, the thickness from the second surface 102 to the first surface 101 of the base 10 is formed to be 0.5 mm or more, and the height of the convex portion 104 is formed to be less than 0.5 mm. In this way, stable bonding can be achieved, and the size of the light emitting device 1 can be reduced.

[0020] The overall shape of the base 10 is a rectangular parallelepiped shape having a protrusion 104 near the outer edge of one face. Such a base 10 can be made of, for example, metal. Here, being made of metal includes a case where the base is made of only metal and a case where the base is made of metal as the main material. Specifically, the base 10 is made of copper. In addition, as metals other than copper, copper, aluminum, iron, and composites such as copper molybdenum, copper-diamond, and copper tungsten can also be used.

[0021] The frame portion 20 forms a frame. It also has a first upper surface 201, a second upper surface 202, a first lower surface 203, a second lower surface 204, an outer surface 205, a first inner surface 206, a second inner surface 207, and a third inner surface 208. The first upper surface 201 and the first lower surface 203 intersect with the outer surface 205. Both the second upper surface 202 and the second lower surface 204 are formed between the first upper surface 201 and the first lower surface 203. The second upper surface 202 is formed between the first upper surface 201 and the second lower surface 204. The second lower surface 204 is formed between the second upper surface 202 and the first lower surface 203.

[0022] On the side opposite the outer side 205, the first upper surface 201 intersects with the first inner side surface 206. On the side opposite the outer side surface 205, the first lower surface 203 intersects with the second inner side surface 207. On the side opposite the first upper surface 201, a part of the first inner side surface 206 intersects with the second lower surface 204, and another part intersects with the second upper surface 202. In other words, a part of the first inner side surface 206 continues to the second lower surface 204, and the remainder intersects with the second upper surface 202 above the second lower surface 204. Also, the second upper surface 202 is partially provided in the frame portion 20.

[0023] On the side opposite the first inner side surface 206, the second upper surface 202 intersects with the third inner side surface 208. On the side opposite the second upper surface 202, the third inner side surface 208 intersects with the second lower surface 204. Therefore, in the region having the second upper surface 202, a step is formed inward from the first inner side surface 206 based on the second upper surface 202 and the third inner side surface 208.

[0024] With respect to the entire inner surface of the frame portion 20, when viewed in a direction perpendicular to the first lower surface 203, there are a region having the first inner surface 206 and the third inner surface 208, and a region having the first inner surface 206 and not the third inner surface 208. In the former region, the second inner surface 207 is closer to the outer surface 205 than the first inner surface 206 and the third inner surface 208. In the latter region, the second inner surface 207 is closer to the outer surface 205 than the first inner surface 206. Note that in the former region, the second inner surface 207 may be at the same position as the first inner surface 206, or may be closer to the third inner surface 208 than the first inner surface 206.

[0025] The frame 20 can be formed mainly from ceramic. Specifically, the frame 20 is formed mainly from aluminum oxide (alumina) as ceramic. Furthermore, aluminum nitride, silicon nitride, silicon carbide, etc. can also be used as ceramics mainly made from materials other than aluminum oxide. A metal film 209 is provided on the second upper surface 202 and the first lower surface 203 of the frame 20. Furthermore, the metal film 209 on the second upper surface 202 and the metal film 209 on the first lower surface 203 can be electrically connected by a metal passing through the inside of the base 10.

[0026] The semiconductor laser element 30 has a bottom surface, a top surface, and a side surface, and emits laser light from one of the side surfaces. For the three semiconductor laser elements 30, for example, a semiconductor laser element 30 emitting blue light can be adopted. Note that the color is not limited to blue, and for example, a semiconductor laser element 30 emitting light of another color such as red or green may be adopted. In addition, all the semiconductor laser elements 30 mounted on the light emitting device 1 do not have to be semiconductor laser elements 30 emitting light of the same color. For example, the three semiconductor laser elements 30 may be configured by adopting one each of blue, green, and red semiconductor laser elements 30.

[0027] Here, blue light refers to light whose emission peak wavelength is in the range of 420 nm to 494 nm. An example of the semiconductor laser element 30 that emits blue light is a semiconductor laser element 30 that includes a nitride semiconductor. Examples of the nitride semiconductor that can be used include GaN, InGaN, and AlGaN.

[0028] Red light refers to light whose emission peak wavelength is in the range of 605 nm to 750 nm. Examples of the semiconductor laser element 30 that emits red light include those that include InAlGaP-based, GaInP-based, GaAs-based, and AlGaAs-based semiconductors.

[0029] The green light refers to light whose emission peak wavelength is in the range of 495 nm to 570 nm. An example of the semiconductor laser element 30 that emits green light is a semiconductor laser element 30 that includes a nitride semiconductor. Examples of the nitride semiconductor that can be used include GaN, InGaN, and AlGaN.

[0030] The submount 40 has a bottom surface, a top surface, and side surfaces, and is configured in a rectangular parallelepiped shape. However, the shape is not limited to a rectangular parallelepiped. The submount 40 can be formed using, for example, silicon nitride, aluminum nitride, or silicon carbide. However, it is not limited to these, and other materials can also be used. In addition, a metal film is provided on the top surface of the submount 40.

[0031] The light reflecting member 50 has a lower surface, an upper surface, a side surface, and a light reflecting surface. The side surface intersects with the lower surface, and also intersects with the upper surface and the light reflecting surface on the side opposite the lower surface. The light reflecting surface is a flat surface that intersects with the upper surface, is inclined from the upper surface to the lower surface, and intersects with the side surface at the lower surface side. Therefore, the light reflecting surface is provided with a height from the lower surface that is equal to the height of the side surface that intersects with the lower surface side. The light reflecting surface is designed to form an angle of 45 degrees with the lower surface. This angle does not have to be limited to 45 degrees, and the light reflecting surface may be a curved surface instead of a flat surface.

[0032] The light reflecting member 50 can be formed, for example, by forming its outer shape from a main material and forming a light reflecting film on the surface of the formed outer shape that is to be provided with a light reflecting surface. The main material is preferably a heat-resistant material, and for example, glass such as quartz or BK7 (borosilicate glass), metal such as aluminum, or Si can be used. The light reflecting film is preferably a material with high light reflectance, and for example, metal such as Ag or Al, or dielectric multilayer film such as Ta2O5 / SiO2, TiO2 / SiO2, or Nb2O5 / SiO2 can be used.

[0033] In addition, when the outer shape is formed mainly using a material with high light reflectance such as metal, the formation of the light reflecting film may be omitted. The light reflecting surface can have a light reflectance of 99% or more for the peak wavelength of the laser light to be reflected. These light reflectances can be 100% or less or less than 100%. The protective element 70 is, for example, a Zener diode.

[0034] The cover member 80 has a bottom surface, a top surface, and a side surface, is configured in a rectangular parallelepiped shape, and is translucent as a whole. Note that it may have a non-translucent region in part. Also, the shape is not limited to a rectangular parallelepiped. The cover member 80 may be formed using sapphire as the main material. Also, a metal film is provided in a part of the region. Sapphire is a material that has a relatively high refractive index and is also relatively strong. Note that, in addition to sapphire, for example, glass or the like may be used as the main material.

[0035] The substrate 2 has a bottom surface, side surfaces, and a top surface. The top surface of the substrate 2 has a region where a metal film and an insulating film are provided. The substrate 2 is mainly made of a metal, and aluminum or copper, for example, may be used. The substrate 2 may be made of multiple metals or multiple metal layers.

[0036] Next, the light emitting device 1 manufactured using these components will be described. First, the base 10 and the frame 20 are joined together to form a package in which the semiconductor laser element is disposed. The base 10 and the frame 20 are joined together at the convex upper surface 105 of the base 10 and the second lower surface 204 of the frame 20, respectively. For example, joining to the second lower surface 204 of the frame 20 can be performed using Ag brazing, Au brazing, AuSn, or the like.

[0037] Compared with the outer diameters of the first surface 101 and the second surface 102 of the base 10, the opening by the first lower surface 203 of the frame 20 is larger than this, and the opening by the second lower surface 204 of the frame 20 is smaller than this. Therefore, the structural relationship between the base 10 and the frame 20 is such that the base 10 can enter the frame from the first lower surface 203 side of the frame 20, and further entry is stopped at the stage where the convex upper surface 105 of the base 10 comes into contact with the second lower surface 204 of the frame 20.

[0038] When the base 10 and the frame 20 are joined together, the convex upper surface 105 is not exposed in a top view. Since the entire convex upper surface 105 is joined to the second lower surface 204, the second lower surface 204 has a shape and area that can include the convex upper surface 105. Therefore, the area of ​​the second lower surface 204 is larger than the area of ​​the convex upper surface 105. In addition, the width of the second lower surface 204, in other words, the distance between the second inner surface 207 and the third inner surface 208 or the distance between the second inner surface 207 and the first inner surface 206, is larger than the width of the convex upper surface 105, in other words, the distance between the convex outer surface 106 and the convex inner surface 107.

[0039] In addition, in a planar direction parallel to the first surface 101, the width of the convex surface 105 is smaller than the distance from the outer surface 103 of the base 10 to the third inner surface 208 of the frame 20. In an area of ​​the inner surface of the frame 20 that does not have the third inner surface 208, the width of the convex surface 105 is smaller than the distance from the outer surface 103 of the base 10 to the first inner surface 206 of the frame 20.

[0040] By having such convex parts 104 in the base 10, the joining stress between the frame and the base 10 is concentrated in the convex parts 104, and the convex parts 104 can deform and absorb the stress. This makes it possible to suppress cracks and deformations due to stress when joining the base 10 and the frame 20, which are made mainly of materials with different thermal expansion coefficients.

[0041] The thermal expansion coefficient here refers particularly to the linear expansion coefficient. The thermal expansion coefficient of the metal constituting the base 10 is in the range of 5.0 to 18.0. The thermal expansion coefficient of the ceramic constituting the frame 20 is in the range of 2.0 to 8.0. The difference in the thermal expansion coefficient between the base 10 and the frame 20 is in the range of 1.0 to 12.0.

[0042] It should be noted that materials having thermal expansion coefficients outside the numerical ranges listed here may be used as the metal constituting the base 10 and the ceramic constituting the frame 20. Therefore, members having different thermal expansion coefficients can be, for example, members whose thermal expansion coefficients differ from each other in a range of 0.5 to 15.0. Furthermore, members whose thermal expansion coefficients differ from each other in a range of 0.5 to 15.0 in a temperature range of -40°C to 150°C can be said to be members whose thermal expansion coefficients differ from each other in a range of 0.5 to 15.0 in a temperature range of -40°C to 150°C.

[0043] In addition, frame portion 20 made primarily of alumina has a smaller difference in thermal expansion coefficient with base portion 10 made primarily of copper than frame portion 20 made primarily of aluminum or other materials, and is therefore effective in preventing cracks, deformation, and the like.

[0044] Furthermore, by having the protruding portion 104 of the base 10 protrude at a position spaced apart from the outer surface of the base 10, even if the second inner surface 207 of the frame 20 and the outer surface 103 of the base 10 come into partial contact with each other due to misalignment during mounting, it is possible to avoid contact with the convex outer surface 106. If the convex outer surface 106 comes into contact with the second inner surface 207, it will suppress deformation of the protruding portion 104 due to stress, reducing the stress absorption effect, but if they are spaced apart, this effect will be eliminated.

[0045] The joining region, which is the region where the convex upper surface 105 of the base 10 and the second lower surface 204 of the frame 20 are joined, includes the center of the width of the second lower surface 204. This makes it possible to balance the external force that the base 10 applies to the second lower surface 204 of the frame 20 due to temperature changes.

[0046] The convex inner side surface 107 of the base 10 is closer to the outer side surface 103 than the third inner side surface 208 of the frame 20, or the first inner side surface 206 in a region not having the third inner side surface 208. That is, in the second lower surface 204, an end of the convex inner side surface 107 is joined to the second lower surface 204 at a position away from an end portion that intersects with the third inner side surface 208 or the first inner side surface 206 in a region not having the third inner side surface 208. This makes it possible to balance the external force that the base 10 applies to the second lower surface 204 of the frame 20 due to temperature changes.

[0047] The second surface 102 of the base 10 and the first lower surface 203 of the frame 20 are arranged on the same plane. Note that errors resulting from implementation based on a design in which they are arranged on the same plane are included in the interpretation of "on the same plane." In the light emitting device 1, if the distance between the plane having the second surface 102 of the base 10 and the plane having the first lower surface 203 of the frame 20 is 0.1 mm or less, this can be included in the interpretation of "on the same plane."

[0048] The three semiconductor laser elements 30 are disposed on the first surface 101 of the base 10 via the submount 40. A separate submount 40 is provided for each semiconductor laser element 30. A plurality of semiconductor laser elements 30 may be disposed on the upper surface of one submount 40. The base 10, which is mainly made of copper, has excellent thermal conductivity and can act as a heat dissipation member that effectively dissipates heat generated by the semiconductor laser elements 30.

[0049] The semiconductor laser element 30 disposed on the base 10 is surrounded by the frame 20. Moreover, the semiconductor laser element 30 disposed on the base 10 is located lower than the first upper surface 201 of the frame 20. That is, the semiconductor laser element 30 is disposed inside the cavity formed by the base 10 and the frame 20. In other words, it can be said that the cavity of the package in which the base 10 and the frame 20 are joined surrounds the semiconductor laser element 30.

[0050] The submount 40 is bonded at its bottom surface to the first surface 101 of the base 10, and at its top surface to the semiconductor laser element 30. The semiconductor laser element 30 is disposed so that the emission end surface of the semiconductor laser element 30 is aligned with or protrudes from the side surface of the submount 40. By using the submount 40, the height from the first surface 101 to the light emission position of the semiconductor laser element 30 can be increased. In addition, a protection element 70 is disposed on the top surface of the submount 40.

[0051] The submount 40 is designed so that the height from the first surface 101 is the same among the three semiconductor laser elements 30. The emission end faces of the semiconductor laser elements 30 are designed to be arranged on the same virtual plane. Even if the designs are the same, errors will occur due to material tolerances and mounting tolerances at the mounting stage. When it is said that the height, length, position, relative positional relationship, etc. of the light emitting device 1 are the same, it is assumed that such errors are within the allowable range.

[0052] It is not necessary to make the height of the submount 40 the same among the three semiconductor laser elements 30. For example, when the light emitting points of the three semiconductor laser elements 30 are different due to differences in mounting orientation, etc., it is possible to adopt submounts 40 of different heights in order to make the heights from the first surface 101 to the light emitting points the same by using the submounts 40. It is also possible that the emission end faces are arranged not on the same plane but on different parallel planes.

[0053] The light reflecting member 50 is disposed on the first surface 101 of the base 10. A separate light reflecting member 50 is disposed corresponding to each semiconductor laser element 30. Moreover, the three semiconductor laser elements 30 are designed so that the distance between the emission end surface of each semiconductor laser element 30 and the corresponding light reflecting member 50 is the same. Note that one light reflecting member 50 may be disposed corresponding to a plurality of semiconductor laser elements 30.

[0054] Since the light emitted from the semiconductor laser element 30 has an elliptical FFP (far-field pattern), by raising the emission position via the submount 40, more of the light emitted from the semiconductor laser element 30 can be irradiated onto the light reflecting surface of the light reflecting member 50.

[0055] One end of each of a plurality of wires is joined to the metal film 209 provided on the second upper surface 202 of the frame portion 20. The other ends of each of the plurality of wires are joined to the metal film 209 provided on the upper surface of the semiconductor laser element 30, the protection element 70, or the submount 40, respectively. As a result, the semiconductor laser element 30 and the protection element 70 are electrically connected to each other via the metal film 209 provided on the first lower surface 203 of the frame portion 20.

[0056] With regard to the inner surface of the frame 20, the third inner surface 208 is not provided in a region that faces the side surface opposite the light reflecting surface and intersects with the upper surface of the light reflecting member 50, and is closest to the side surface. Therefore, the second upper surface 202 is not provided in this region either. This is because if the second upper surface 202 is provided in this region and a wire is stretched, the wire will cross the light reflecting member 50 and become an obstacle in the optical path of the reflected light. Also, by not providing the third inner surface 208 around the entire circumference of the inner surface, the size of the light emitting device 1 can be reduced.

[0057] The lower surface of the lid member 80 is bonded to the first upper surface 201 of the frame portion 20. A metal film is provided in the bonded area of ​​the lid member 80 and the frame portion 20, and the lid member 80 and the frame portion 20 are fixed via Au-Sn or the like. Furthermore, a closed space is formed by bonding the frame portion 20 and the lid member 80. This closed space is a hermetically sealed space.

[0058] Such airtight sealing can prevent organic matter and the like from collecting on the light emitting end face of the semiconductor laser element 30. In addition, since there is a small difference in thermal expansion coefficient between the frame 20 made mainly of alumina and the lid member 80 made mainly of sapphire, this is effective in preventing cracks, deformation, and the like.

[0059] The light reflected by the light reflecting surface of the light reflecting member 50 enters the cover member 80. The cover member 80 is designed so that at least the region where the reflected light of the main part of the light enters and leaves is translucent. Here, translucency means that the light transmittance is 80% or more.

[0060] In the light emitting device 1, the metal film 209 provided on the first lower surface 203 of the frame portion 20 and the second surface 102 of the base portion 10 are joined to the substrate 2. Furthermore, by joining the metal film 209 provided on the first lower surface 203 of the frame portion 20 to the metal film of the substrate 2, electrical connection can be achieved via the metal film of the substrate 2. The joining of the light emitting device 1 and the substrate 2 can be performed by soldering.

[0061] According to the light emitting device 1 of the first embodiment, the protrusions 104 provided on the base 10 absorb stress, thereby making it possible to suppress the occurrence of cracks, breakage, peeling, etc. Also, in a package in which at least the base 10 and the frame 20 are joined and in which a light emitting element such as the semiconductor laser element 30 is mounted, the occurrence of cracks, breakage, peeling, etc. can be suppressed.

[0062] The following describes a base 10 having a different shape from the base 10 employed in the light emitting device 1 of the first embodiment. Even the base 10 as described below can be joined to the frame 20 to form a package.

[0063] <Second embodiment> 11 is a cross-sectional view for explaining the shapes of the base 10 and the frame 20 of the light emitting device according to the second embodiment. The position of the cross section is the same as that of line IX-IX in FIG. 8. The light emitting device according to the second embodiment differs from the light emitting device according to the first embodiment in the shape of the base. Specifically, the base 10A in FIG. 11 differs from the base 10 of the first embodiment in that it has a recessed portion 108 between the second surface 102 and the outer surface 103 on the second surface 102 side of the base 10.

[0064] The recessed portion 108 of the base 10A is provided to make the distance between the second surface 102 of the base 10A and the second inner surface 207 of the frame 20 larger than the distance between the second surface 102 of the base 10A and the outer surface 103 of the base 10A. Therefore, the recessed portion 108 is recessed from the second surface 102 of the base 10 toward the first surface 101 side. Even if the second inner surface 207 and the outer surface 103 come into contact as a result of a deviation from the designed positional relationship occurring in the joining of the base 10A and the frame 20, the provision of the recessed portion 108 makes it possible to prevent the second surface 102 of the base 10A from being electrically connected to the metal film of the substrate 2.

[0065] <Third embodiment> Fig. 12 is a cross-sectional view for explaining the shapes of the base 10 and frame 20 of the light emitting device according to the third embodiment. The position of the cross section is the same as that of line IX-IX in Fig. 8. The light emitting device according to the third embodiment differs from the light emitting device according to the first embodiment in the shape of the base. Specifically, the base 10B in Fig. 12 differs from the base 10 of the first embodiment in the position where the convex portion 104 is provided on the side of the first surface 101 of the base 10.

[0066] In the base 10B according to the third embodiment, the convex portion 104 is provided without being spaced apart from the outer surface 103. In other words, the convex outer surface 106 of the convex portion 104 and the outer surface 103 of the base 10B are formed by a single side surface, and the outer surface 103 of the base 10B also serves as the convex outer surface 106 of the convex portion 104. Even with this shape, like the base 10 of the first embodiment, the convex portion 104 provided on the base 10 can absorb stress.

[0067] <Fourth embodiment> FIG. 13 is a cross-sectional view for explaining the shapes of the base 10 and the frame 20 of the light-emitting device according to the fourth embodiment. The position of the cross section is the same as that of the line IX-IX in FIG. 8. The light-emitting device according to the fourth embodiment differs from the light-emitting device according to the first embodiment in the shape of the base. Specifically, the base 10C in FIG. 14 has a shape that combines the differences between the base 10 of the first embodiment and the second embodiment and the third embodiment. That is, the base 10C has a recess 108 on the second surface 102 side, and a protrusion 104 is provided on the first surface 101 side without being spaced from the outer surface 103.

[0068] Although the present invention has been described above based on each embodiment, the configuration of the light emitting device to which the present invention is applied is not limited to that of the embodiment. For example, the light emitting device in which three semiconductor laser elements are arranged has been described, but the light emitting device may be a light emitting device in which one or more semiconductor laser elements are arranged. In addition, the light emitting device may not have a light reflecting member, and the light emitted from the semiconductor laser element may pass through a cover member.

[0069] In other words, the light emitting device to which the present invention is applied may have, for example, components that are not disclosed in the light emitting device of the embodiment. Conversely, it may not have some of the components that are disclosed in the light emitting device of the embodiment. The mere existence of a difference from the light emitting device of the embodiment is not a reason for not being able to apply the present invention.

[0070] For example, if some components of the light-emitting device disclosed in the first embodiment are not described in the claims, the freedom of design by a person skilled in the art to substitute, omit, modify the shape, change the material, etc. of those components in relation to the disclosure of the first embodiment is recognized, and the invention described in the claims is claimed to apply. [Industrial Applicability]

[0071] The light emitting device according to each embodiment can be used in projectors, vehicle headlights, lighting, displays, and the like. [Explanation of symbols]

[0072] 1 Light emitting device 10, 10A, 10B, 10C base 101 Page 1 102 Side 2 103 External surface 104 Convex 105 Convex top surface 106 Convex outer surface 107 Convex inner surface 108 Recess 20 Frame 201 1st top surface 202 2nd top surface 203 1st bottom surface 204 2nd bottom surface 205 External surface 206 1st inner surface 207 Second inner surface 208 Third inner surface 209 Metal Film 30 Semiconductor laser element 40 Submount 50 Light reflecting material 70 Protection elements 80 Lid member 2. Board

Claims

1. A first semiconductor laser element; a light reflecting member having a light reflecting surface that reflects light emitted from the first semiconductor laser element; a base having a first surface on which the first semiconductor laser element and the light reflecting member are disposed, and a convex portion formed on the first surface side outside an area in which the first semiconductor laser element and the light reflecting member are disposed; a frame portion made of a material having a thermal expansion coefficient different from that of a main material used for the base, the frame portion having a bonding surface bonded to a protruding upper surface of the convex portion of the base, the frame portion surrounding the first semiconductor laser element and the light reflecting member disposed on the first surface; having the frame portion has a first upper surface and a second upper surface located below the first upper surface, and a thickness of the first upper surface in a vertical direction is greater than a thickness of the second upper surface in a vertical direction; At least a part of a protruding upper surface of the convex portion of the base is joined to the joining surface at a position overlapping the second upper surface in a top view, The first semiconductor laser element and the light reflecting member are disposed in a hermetically sealed space.

2. A light-emitting device as described in claim 1, wherein at least a portion of the protruding upper surface of the convex portion of the base that does not overlap with the second upper surface in a top view is joined to the joining surface at a position that overlaps with the first upper surface in a top view.

3. The frame portion has an outer surface and a first lower surface intersecting the outer surface, the first upper surface intersects with the outer surface; The light emitting device according to claim 1 , wherein the bonding surface of the frame portion is a second lower surface formed between the first upper surface and the first lower surface.

4. the frame portion has a first inner side surface on the first upper surface side of the frame portion, and a second inner side surface on the first lower surface side of the frame portion and at least a portion of the second inner side surface on the outer surface side of the first inner side surface, The light emitting device according to claim 3 , wherein a bonding surface of the frame portion is the second lower surface that extends at least in part from the second inner surface side to the first inner surface side.

5. the frame portion has a third inner side surface formed between the first upper surface and the first lower surface of the frame portion and between the second upper surface and the second lower surface, and more inward than the first inner side surface, a metal film electrically connecting the first semiconductor laser element to at least a part of the second upper surface of the frame portion; The light emitting device according to claim 4 , wherein the second upper surface extends inwardly from at least a portion of the first inner surface.

6. The light-emitting device according to any one of claims 1 to 5, wherein the base has a convex portion on the side of the first surface, protruding at a position spaced from the position where the base intersects with the outer surface of the base, and the protruding upper surface is formed inward from the protruding position.

7. The light emitting device according to claim 1 , wherein the protruding upper surface of the convex portion intersects with an outer surface of the base on the side of the first surface.

8. The light emitting device according to claim 1 , wherein an area of ​​the protruding upper surface of the base is smaller than an area of ​​a bonding surface of the frame.

9. 9. The light emitting device according to claim 1, wherein the base has, on the side opposite the first surface, a second surface and a recess portion that intersects with the second surface and an outer surface of the base and is recessed from the second surface toward the first surface.

10. 10. The light emitting device according to claim 1, wherein the base is mainly made of a metal, and the frame is mainly made of a ceramic.

11. The light emitting device according to claim 1 , further comprising a second semiconductor laser element disposed on the first surface.

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