Submount and light-emitting device

Abstract

To provide a light-emitting device capable of reducing a package size.SOLUTION: A light-emitting device comprises at least one semiconductor laser element having an emission side surface from which laser light is emitted, a submount having an upper surface on which the at least one semiconductor laser element is disposed, and a base having a mounting surface on which the submount is fixed. The submount has: a first side surface located on a side of the emission side surface of the at least one semiconductor laser element, intersecting the upper surface, and positioned above and away from the mounting surface; a lower surface joined to the mounting surface of the base, the lower surface being recessed inward of the submount relative to an edge where the upper surface and the first side surface intersect, in a top view from a normal direction to the upper surface; and a second side surface located on the same side as the first side surface and intersecting the lower surface. A bonding layer formed of the bonding material is formed between the mounting surface of the base and the lower surface of the submount, and a portion of the bonding material protrudes from the lower surface and extends outward beyond an edge where the lower surface and the second side surface intersect.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a light emitting device and a method for manufacturing a light emitting device. [Background technology]

[0002] Conventionally, there are light-emitting devices in which multiple components are mounted within a package. Examples of the multiple components include one or more light-emitting elements, a submount, and a substrate. For example, Patent Document 1 discloses a semiconductor laser module including one semiconductor laser element, a submount, a conductive part, and a substrate. The substrate has a groove recessed downward from the edge of the area where the submount is located. This groove is said to prevent solder from creeping up beyond the area where the submount is located, making it less likely to cause dielectric breakdown. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-165119 Summary of the Invention [Problem to be solved by the invention]

[0004] This allows the light emitting device to be made smaller. [Means for solving the problem]

[0005] In an exemplary, non-limiting embodiment, the light emitting device of the present disclosure comprises at least one semiconductor laser element having an emission side that emits laser light, a submount having an upper surface on which the at least one semiconductor laser element is disposed, and a base having a mounting surface for fixing the submount, wherein the submount has: a first side that is located on the side of the emission side of the at least one semiconductor laser element, intersects with the upper surface, and is spaced upward from the mounting surface; a lower side that is joined to the mounting surface of the base, the lower side being recessed inward of the submount from an edge where the upper surface and the first side intersect, in a top view seen from a direction normal to the upper surface; and a second side that is located on the same side as the first side and intersects with the lower surface; and a bonding layer made of a bonding material is formed between the mounting surface of the base and the lower surface of the submount, and a portion of the bonding material protrudes from the lower surface and reaches outside the edge where the lower surface and the second side intersect.

[0006] In an exemplary, non-limiting embodiment, a method for manufacturing a light-emitting device according to the present disclosure is a method for manufacturing a light-emitting device comprising a submount having an upper surface on which at least one semiconductor laser element is disposed, and a base having a mounting surface to fix the submount, the method including: forming one or more recesses around the periphery of the upper surface of the submount; forming a first wiring region on the upper surface of the submount; forming a second wiring region on the mounting surface of the base; applying a paste material to the mounting surface of the base and / or the lower surface of the submount; sintering the paste material to form a bonding layer between the mounting surface of the base and the lower surface of the submount, thereby bonding the submount to the mounting surface of the base; and sintering a conductive paste material to form one or more conductive members in contact with the one or more recesses formed around the periphery of the upper surface of the submount, thereby electrically connecting the first wiring region formed on the upper surface of the submount and the second wiring region formed on the mounting surface of the base. [Effects of the Invention]

[0007] According to the embodiments of the present disclosure, a small-sized light emitting device can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a light emitting device according to each embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view of the light emitting device according to the first embodiment of the present disclosure with the package cap removed. [Figure 3] FIG. 3 is a rear view of the light emitting device according to the first embodiment of the present disclosure as viewed from the positive direction of the X axis in the drawing. [Figure 4] FIG. 4 is a side view of the light emitting device according to the first embodiment of the present disclosure when viewed from the negative direction of the Z axis in the drawing. [Figure 5] FIG. 5 is a top view of the light emitting device according to the first embodiment of the present disclosure with the package cap removed. [Figure 6] FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. [Figure 7] FIG. 7 is a perspective view of a base according to the first embodiment of the present disclosure. [Figure 8] FIG. 8 is a perspective view of a submount according to the first embodiment of the present disclosure. [Figure 9A] FIG. 9A is a rear view of the submount according to the first embodiment of the present disclosure as viewed from the positive direction of the X axis in the drawing. [Figure 9B] FIG. 9B is a side view of the submount according to the first embodiment of the present disclosure when viewed from the negative direction of the Z axis in the drawing. [Figure 10] FIG. 10 is an exploded perspective view of the submount according to the first embodiment of the present disclosure. [Figure 11] FIG. 11 is an enlarged view of a portion X1 in the side view of FIG. [Figure 12A] FIG. 12A is a side view illustrating a variation of the submount according to the first embodiment of the present disclosure. [Figure 12B]FIG. 12B is a side view illustrating a variation of the submount according to the first embodiment of the present disclosure. [Figure 13] FIG. 13 is a perspective view of the light emitting device according to the second embodiment of the present disclosure with the package cap removed. [Figure 14] FIG. 14 is a rear view of the light emitting device according to the second embodiment of the present disclosure as viewed from the positive direction of the X axis in the drawing. [Figure 15] FIG. 15 is a side view of the light emitting device according to the second embodiment of the present disclosure when viewed from the negative direction of the Z axis in the drawing. [Figure 16] FIG. 16 is a top view of the light emitting device according to the second embodiment of the present disclosure with the package cap removed. [Figure 17] FIG. 17 is a perspective view of a base according to a second embodiment of the present disclosure. [Figure 18] FIG. 18 is a perspective view of a submount according to the second embodiment of the present disclosure. [Figure 19A] FIG. 19A is a rear view of a submount according to a second embodiment of the present disclosure as viewed from the positive direction of the X axis in the drawing. [Figure 19B] FIG. 19B is a side view of the submount according to the second embodiment of the present disclosure as viewed from the negative direction of the Z axis in the drawing. [Figure 20] FIG. 20 is an exploded perspective view of a submount according to the second embodiment of the present disclosure. [Figure 21] FIG. 21 is an enlarged view of a portion X2 in the side view of FIG. [Figure 22] FIG. 22 is a perspective view of a light emitting device according to the third embodiment of the present disclosure with the package cap removed. DETAILED DESCRIPTION OF THE INVENTION

[0009] In this specification and claims, polygons such as triangles and quadrilaterals are not limited to polygons in the strict mathematical sense, but also include shapes in which the corners of the polygon have been processed, such as rounded, chamfered, corner-cut, or rounded. Furthermore, shapes in which processing has been applied not only to the corners (edges) of polygons, but also to the middle portions of the edges are also referred to as polygons. In other words, shapes in which partial processing has been applied while retaining the polygonal base are included in the "polygon" described in this specification and claims.

[0010] This is not limited to polygons, but also applies to words that describe specific shapes such as trapezoids, circles, and irregularities. The same applies when dealing with the sides that form the shape. In other words, even if the corners or middle part of a side are processed, the processed part is included in the "side." When distinguishing a "polygon" or "side" that has no processing from a processed shape, the word "strict" is added, for example, "strict quadrilateral."

[0011] In this specification or claims, when there are multiple elements identified by a certain name and each element needs to be distinguished, an ordinal number such as "first" or "second" may be added to the beginning of each element. For example, if a claim states that "light-emitting elements are arranged on a substrate," the specification may state that "first and second light-emitting elements are arranged on a substrate." The ordinal numbers "first" and "second" are used simply to distinguish between two light-emitting elements. The order of these ordinal numbers has no particular meaning. Element names with the same ordinal number attached may not refer to the same element between the specification and the claims. For example, if elements identified with the terms "first light-emitting element," "second light-emitting element," and "third light-emitting element" are described in the specification, the "first light-emitting element" and "second light-emitting element" in the claims may correspond to the "first light-emitting element" and "third light-emitting element" in the specification. Furthermore, if the term "first light-emitting element" is used but the term "second light-emitting element" is not used in claim 1 described in the claims, the invention according to claim 1 may be provided with one light-emitting element, and the light-emitting element is not limited to the "first light-emitting element" in the specification, but may be the "second light-emitting element" or the "third light-emitting element."

[0012] In this specification or claims, terms indicating specific directions or positions (e.g., "upper," "lower," "right," "left," "front," "rear," and other terms including these terms) may be used. These terms are used merely to facilitate understanding of relative directions or positions in the referenced drawings. As long as the relationship of relative directions or positions indicated by terms such as "upper" and "lower" in the referenced drawings is the same, drawings other than those of this disclosure, actual products, manufacturing equipment, etc. may not be arranged in the same manner as in the referenced drawings.

[0013] The dimensions, dimensional ratios, shapes, spacing, etc. of elements or components shown in the drawings may be exaggerated for clarity, and some elements may be omitted to avoid overly complicated drawings.

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments embody the technical concept of the present invention, but do not limit the present invention. The numerical values, shapes, materials, order of processing steps, etc. shown in the description of the embodiments are merely examples, and various modifications are possible as long as no technical contradiction occurs. In the following description, elements identified by the same names and symbols are the same or similar elements, and redundant descriptions of these elements may be omitted.

[0015] (First embodiment) A light emitting device 100 according to this embodiment will be described with reference to FIGS.

[0016] FIG. 1 is a perspective view of a light-emitting device 100 according to this embodiment. For ease of explanation, the accompanying drawings show mutually orthogonal X, Y, and Z axes. The perspective view of the exterior of a light-emitting device 101 according to a second embodiment and a light-emitting device 102 according to a third embodiment, which will be described later, is also shown in FIG. 1, but the internal configurations differ between the embodiments. FIG. 2 is a perspective view of the light-emitting device 100 with the cap 16 of the package 10 removed. FIG. 3 is a rear view of the light-emitting device 100 as viewed from the positive direction of the X axis in the figure. FIG. 4 is a side view of the light-emitting device 100 as viewed from the negative direction of the Z axis in the figure. In FIGS. 3 and 4, a portion of the side surface of the cap 16 is shown in a see-through manner so that the light-emitting element 20 inside the package 10 can be seen. FIG. 5 is a top view of the light-emitting device 100 with the cap 16 of the package 10 removed. FIG. 6 is a cross-sectional view taken along the VI-VI line in FIG. 1. In Figures 5 and 6, dashed lines indicate representative light rays contained in the main portion of the laser light LB emitted from the light-emitting element 20. In Figure 6, dashed arrows also indicate light traveling along the optical axis of the laser light LB emitted from the light-emitting element 20. Note that, for ease of viewing, the wiring 70 is omitted from Figure 6. Figure 7 is a perspective view of the base 11. Figure 8 is a perspective view of the submount 30. Figure 9A is a rear view of the submount 30 as viewed from the positive direction of the X axis in Figure 8. Figure 9B is a side view of the submount 30 as viewed from the negative direction of the Z axis in Figure 8. For ease of explanation, in Figures 9A and 9B, a plane including the bottom surface 30d of the submount 30 is indicated by a dashed line. Figure 10 is an exploded perspective view of the submount 30.

[0017] The light emitting device 100 according to this embodiment includes a plurality of components including a package 10, one or more light emitting elements 20, a submount 30, and one or more wirings 70. In the illustrated example of the light emitting device 100, three light emitting elements 20, a submount 30, and multiple wirings 70 are arranged in the space inside the package 10. Furthermore, divergent light emitted from the three light emitting elements 20 is each emitted laterally from the package 10 to the outside.

[0018] First, each component will be described.

[0019] (Package 10) The package 10 has a base 11 including a mounting surface 11M and sidewalls 12 surrounding the mounting surface 11M. The mounting surface 11M of the base 11 is an area on which other components are arranged. The package 10 also has a substrate 15 and a cap 16 fixed to the substrate 15. The substrate 15 has the base 11, and the cap 16 has the sidewalls 12.

[0020] In the illustrated example, the cap 16 has an upper portion and a side wall portion 12. The base portion 11 includes the bottom surface of the package 10, the side wall portion 12 includes one or more side surfaces of the package 10, and the upper portion includes the top surface of the package 10. Note that the side wall portion 12 does not have to be configured as part of the cap 16. For example, the package 10 can be replaced with a package configured with a single member in which the base portion 11 and the side wall portion 12 are integrated, and another member (a lid member) having an upper portion.

[0021] When viewed from above in the normal direction of the mounting surface 11M of the base 11, the outer shapes of the base 11 and the cap 16 are both rectangular. This rectangle has short sides and long sides. However, these outer shapes do not necessarily have to be rectangular, and may be polygonal shapes other than quadrangles, or shapes that include curves, bends, or irregularities in part or in whole.

[0022] The base 11 has one or more upper surfaces. The one or more upper surfaces of the base 11 include a mounting surface 11M. The base 11 has a peripheral region 11P that surrounds one or more components arranged on the mounting surface 11M. The one or more upper surfaces of the base 11 include an upper surface having the peripheral region 11P. In the example of the light emitting device 100 shown in the figures, the mounting surface 11M and the upper surface having the peripheral region 11P are the same. Note that the mounting surface 11M and the peripheral region 11P do not have to be on the same plane; for example, the mounting surface 11M and the peripheral region 11P may be provided on different upper surfaces having a difference in height.

[0023] The peripheral region 11P is a region to which the cap 16 is bonded. In a top view, the peripheral region 11P is provided between the outer edge of the base 11 and an arrangement region on the mounting surface 11M for arranging multiple components. In the example of the light emitting device 100 shown in the figure, the arrangement region on the mounting surface 11M is approximately rectangular in a top view, and the peripheral region 11P is provided in a rectangular ring shape surrounding the arrangement region. The lower surface of the side wall portion 12 is bonded to the upper surface of the peripheral region 11P. A metal film for bonding to the side wall portion 12 may be provided in the peripheral region 11P.

[0024] As illustrated in Fig. 6, the package 10 has a light-transmitting region 13, which is a region that transmits light. The package 10 also has an exit surface 10a that includes the light-transmitting region 13. The exit surface 10a is included in one of one or more outer surfaces of the side wall portion 12 of the package 10. The side wall portion 12 has the light-transmitting region 13 and includes an entrance surface and an exit surface 10a. Note that having light-transmitting properties means that the transmittance of the main light incident thereon is 80% or more.

[0025] The package 10 may have light-transmitting properties in one or more outer surfaces in areas other than the light-transmitting area 13. The package 10 may also have a non-light-transmitting area (an area that does not have light-transmitting properties) in part. The entire side wall 12 of the package 10 does not need to be light-transmitting. In the example shown in the figure, the package 10 has four rectangular outer surfaces, and all four surfaces are light-transmitting, but only one surface is the light-emitting surface 10a.

[0026] The entire cap 16 may be made of a light-transmitting material, or only the side wall portion 12 may be made of a light-transmitting material. A portion including the light-emitting surface 10a may be made of a first light-transmitting material, and the other portion may be made of a second light-transmitting material or a non-light-transmitting material.

[0027] The cap 16 may be formed by integrally forming the top and sidewalls 12. For example, the cap 16 may be fabricated from a translucent material such as glass, plastic, or quartz using processing techniques such as molding or etching to form a desired shape, such as a box-like shape. The cap 16 may also be formed by joining a top surface (lid portion) and a side surface (frame portion) formed separately from different materials. For example, the top surface may be primarily made of monocrystalline or polycrystalline silicon, while the side surface may be primarily made of glass. The cap 16 may have, for example, a height of 0.6 mm to 2.5 mm, and a rectangular outer side of 1.2 mm to 8 mm in top view. Alternatively, the cap 16 may have, for example, a height of 2 mm or less, and a rectangular outer side of 4 mm or less in top view.

[0028] In the illustrated example of light-emitting device 100, light-emitting surface 10a is perpendicular to the direction in which mounting surface 11M extends. Note that "perpendicular" here includes a difference of ±5 degrees or less. Furthermore, light-emitting surface 10a does not need to be perpendicular to the direction in which mounting surface 11M of base 11 extends, and may be inclined.

[0029] A plurality of wiring regions 14 are provided on the mounting surface 11M. The plurality of wiring regions 14 may be electrically connected to a wiring region provided on the underside of the base 11 through via holes passing through the inside of the base 11. The plurality of wiring regions 14 may be formed from a conductor such as a metal and may be a patterned film or layer. Each wiring region 14 may be a single-layer film or a multi-layer film made of, for example, Au, Ti, Ni, Cr, or Pt.

[0030] The mounting surface 11M is provided with a bonding region 14a. The bonding region 14a may be provided with a patterned film or layer made of a conductor such as a metal. The metal provided in the bonding region 14a may be the same as the metal used to form the wiring region 14. By using the same material, a metal film or metal layer can be formed in the wiring region 14 and the bonding region 14a together.

[0031] 7, the multiple wiring regions 14 are formed symmetrically in top view. Each wiring region 14 can be electrically connected to one or more components and is used to receive power from outside the package 10.

[0032] In the illustrated example, the multiple wiring regions 14 include multiple pairs of wiring regions 14 arranged around the bonding region 14a. In a top view, the bonding region 14a has a larger area than each of the multiple pairs of wiring regions 14. The multiple pairs of wiring regions 14 include a pair of wiring regions 14b located away from the bonding region 14a in the positive direction of the Z axis, a pair of wiring regions 14c located away from the bonding region 14a in the negative direction of the Z axis, and a pair of wiring regions 14d located away from the bonding region 14a in the positive direction of the X axis. The positions at which the pair of wiring regions 14d are located are not far from the bonding region 14a in the Z axis direction. The short side direction of the base 11 is the same as the X axis, and the long side direction of the base 11 is the same as the Z axis. The positive and negative directions are opposite to each other.

[0033] Substrate 15 can be formed primarily from ceramic. Examples of ceramics used for substrate 15 include aluminum nitride, silicon nitride, aluminum oxide, silicon carbide, etc. In this embodiment, substrate 15 can be formed, for example, from a ceramic substrate having a plurality of metal vias therein.

[0034] (Light emitting element 20) An example of the light-emitting element 20 is a semiconductor laser element. The light-emitting element 20 may have a rectangular outer shape when viewed from above. When the light-emitting element 20 is an edge-emitting semiconductor laser element, the side surface intersecting one of the two short sides of this rectangle is the light-emitting side surface 20e. In this example, the upper and lower surfaces of the light-emitting element 20 have a larger area than the light-emitting side surface 20e. The light-emitting element 20 is not limited to an edge-emitting semiconductor laser element, and may be a surface-emitting semiconductor laser element, a light-emitting diode (LED), or the like.

[0035] In this embodiment, the light-emitting element 20 has one or more emitters. The light-emitting element 20 may be a single-emitter element having one emitter, or a multi-emitter element having two or more emitters. For convenience, in FIG. 5, light LB emitted from one emitter is shown for each light-emitting element 20.

[0036] When the light emitting element 20 is a semiconductor laser element, the light (laser light) emitted from the light-emitting side surface 20e of the semiconductor laser element is divergent light having a spread. The laser light forms an elliptical far-field pattern (hereinafter referred to as "FFP") on a plane parallel to the light-emitting side surface 20e. The FFP refers to the shape and light intensity distribution of the emitted light at a position away from the light-emitting surface.

[0037] The light passing through the center of the elliptical shape of the FFP, in other words, the light with peak intensity in the light intensity distribution of the FFP, is called the light traveling along the optical axis. Also, the optical path of the light traveling along the optical axis is called the optical axis of that light. Also, in the light intensity distribution of the FFP, the light with a peak intensity of 1 / e 2 Light having an intensity equal to or greater than this will be referred to as the "main portion" of light.

[0038] In the elliptical shape of the FFP of light emitted from the light emitting element 20, which is a semiconductor laser element, the minor axis direction of the ellipse is called the slow axis direction, and the major axis direction is called the fast axis direction. Multiple layers, including an active layer, that make up the semiconductor laser element can be stacked in the fast axis direction.

[0039] Based on the light intensity distribution of FFP, 1 / e 2 The angle corresponding to the above is defined as the divergence angle of the light from the semiconductor laser element. The divergence angle of the light in the fast axis direction is defined as the divergence angle of the fast axis direction, and the divergence angle of the light in the slow axis direction is defined as the divergence angle of the slow axis direction.

[0040] For example, a semiconductor laser element that emits blue light, a semiconductor laser element that emits green light, or a semiconductor laser element that emits red light can be used as the light emitting element 20. Also, a semiconductor laser element that emits light other than these may be used.

[0041] Here, blue light refers to light whose peak emission wavelength is in the range of 420 nm to 494 nm, green light refers to light whose peak emission wavelength is in the range of 495 nm to 570 nm, and red light refers to light whose peak emission wavelength is in the range of 605 nm to 750 nm.

[0042] Examples of semiconductor laser elements that emit blue light or green light include semiconductor laser elements that contain nitride semiconductors. Examples of nitride semiconductors that can be used include GaN, InGaN, and AlGaN. Examples of semiconductor laser elements that emit red light include those that contain InAlGaP-based, GaInP-based, GaAs-based, and AlGaAs-based semiconductors.

[0043] (Submount 30) An example of the structure of the submount 30 in this embodiment will be described with reference to FIGS.

[0044] The submount 30 has an upper surface 30c, a lower surface 30d, a first side surface 30a, and a second side surface 30b. The submount 30 also has a lower surface 30f. Hereinafter, the lower surfaces 30d and 30f will be referred to as the first lower surface 30d and the second lower surface 30f, respectively, to distinguish them from one another.

[0045] The second side surface 30b is located on the same side as the first side surface 30a. The submount 30 has multiple upper side surfaces 30x including the first side surface 30a and multiple lower side surfaces 30y including the second side surface 30b. The multiple upper side surfaces 30x intersect with the top surface 30c. The multiple lower side surfaces 30y intersect with the first lower surface 30d. The second lower surface 30f intersects with the upper side surfaces 30x and the lower side surfaces 30y. The top surface 30c functions as a mounting surface on which other components are placed. The first lower surface 30d functions as a bonding surface with other components when the submount 30 is placed on the other components.

[0046] In the illustrated example, the multiple upper side surfaces 30x are spaced upward from a plane including the first lower surface 30d. In top view, the first lower surface 30d is recessed toward the inside of the submount 30 from the edge 30e where the top surface 30c and the first side surface 30a intersect. In top view, the second side surface 30b is located more toward the inside of the submount 30 than the first side surface 30a. The second side surface 30b does not intersect with the first side surface 30a.

[0047] The angle α formed between the second side surface 30b and the first lower surface 30d can be, for example, greater than 90° and less than or equal to 100°. In the example shown, the angle α is 90°±5°. The area of the upper surface 30c is larger than the area of the lower surface 30d, and the first lower surface 30d is contained inside the upper surface 30c when viewed from above.

[0048] The distance (first distance) from the first side surface 30a to the second side surface 30b is shorter than the distance (second distance) from the upper side surface 30x opposite the first side surface 30a to the lower side surface 30y opposite the second side surface 30b. The first distance can be 100 μm or more and 200 μm or less. The second distance can be 1.5 times or more and 3.0 times or less the first distance.

[0049] One or more wiring regions 34, which are patterned films or layers made of a conductive material such as metal, may be formed on the upper surface 30c of the submount 30. The one or more wiring regions 34 may be electrically connected to other components. Each wiring region 34 may be a single-layer or multi-layer film made of, for example, Au, Ti, Ni, Cr, or Pt.

[0050] The submount 30 in this embodiment includes a first portion 31 and a second portion 32. The first portion 31 constitutes the top surface 30c and multiple upper side surfaces 30x of the submount 30. The second portion 32 constitutes the multiple lower side surfaces 30y and the bottom surface 30d of the submount 30. The first portion 31 and the second portion 32 may each be separate members. The submount 30 may be formed by bonding the first portion 31 and the second portion 32 together. The submount 30 may also be a single member formed by integrating the first portion and the second portion. Hereinafter, the first portion 31 will be referred to as the first submount 31, and the second portion 32 will be referred to as the second submount 32.

[0051] In the illustrated example, the first submount 31 and the second submount 32 are each configured in a rectangular parallelepiped shape. Using first submount 31 and second submount 32 with such shapes makes it easier to manufacture the submount 30. The shape of each component does not have to be limited to a rectangular parallelepiped. In top view, the area of the first submount 31 is larger than the area of the second submount 32. In top view, the second submount 32 is contained within the first submount 31. The area of the bottom surface 30f of the first submount 31 that is exposed from the second submount 32 becomes the bottom surface 30f of the submount 30.

[0052] In this embodiment, the first submount 31 and the second submount 32 are made of the same main material. However, the main material of the first submount 31 may be different from the main material of the second submount 32. From the viewpoint of forming a wiring region on the top surface 30c of the first submount 31, it is preferable that at least the first submount 31 is made of an insulating material. Examples of the main material that is an insulating material include aluminum nitride or silicon carbide.

[0053] The bonding temperature of metal paste is lower than that of solder, for example. By using metal paste instead of solder as the bonding material, it becomes possible to bond the first submount 31 and the second submount 32 at a relatively low temperature. Although this depends on the manufacturing process for manufacturing the light emitting device 100, it can contribute to reducing damage to the light emitting element 20 bonded to the upper surface 30c of the first submount 31 or the effect on the temperature characteristics.

[0054] (Wiring 70) The wiring 70 is made of a conductor having a linear shape. The wiring 70 is bonded to other components at both ends of the linear portion. The wiring 70 is, for example, a metal wire. Examples of metals include gold, aluminum, silver, and copper.

[0055] (Light emitting device 100) Next, the light emitting device 100 will be described.

[0056] In the example of the light emitting device 100 described below, each of the one or more light emitting elements 20 is an edge-emitting semiconductor laser element (laser diode).

[0057] In the light emitting device 100, one or more light emitting elements 20 are arranged inside the package 10. The one or more light emitting elements 20 are arranged on the mounting surface 11M of the base 11 and are surrounded by the side wall portion 12 of the package 10. Each light emitting element 20 is arranged on the mounting surface 11M via a submount 30. Each light emitting element 20 is disposed on the upper surface 30c of the submount 30. Laser light emitted from at least one light emitting element 20 passes through the side wall portion 12 and is emitted to the outside of the cap 16.

[0058] In the illustrated example of the light emitting device 100, the light emitting device 100 includes a plurality of light emitting elements 20. The light emitting elements 20 are arranged so that their light emitting side surfaces 20e face the light emitting surface 10a of the package 10. The light emitting points of the light emitting elements 20 are aligned in the Z-axis direction. The optical axis of the light emitted from each light emitting element 20 is parallel to the X-axis direction in the drawing. Here, the parallelism includes an error of ±5 degrees or less.

[0059] The light emitting device 100 can include a plurality of light emitting elements 20 including a first light emitting element 20 that emits first light having an emission peak at a first wavelength, a second light emitting element 20 that emits second light having an emission peak at a second wavelength different from the first wavelength, and a third light emitting element 20 that emits third light having an emission peak at a third wavelength different from the first wavelength and the second wavelength.

[0060] In the illustrated example of the light emitting device 100, the light emitting device 100 includes three light emitting elements 20. The three light emitting elements 20 emit light of different colors selected from red light, green light, and blue light, respectively. Note that the colors of light emitted by the light emitting elements 20 are not limited to these, and are not limited to visible light.

[0061] In this specification, the three light-emitting elements 20 may be referred to as a first light-emitting element, a second light-emitting element, and a third light-emitting element, respectively. Furthermore, the light emitted from each light-emitting element 20 may be referred to as a first light, a second light, and a third light.

[0062] The submount 30 is fixed to the bonding region 14a. The submount 30 and the base 11 are bonded to the bonding region 14a with a bonding material such as gold paste. A bonding layer 39 made of the bonding material is formed between the lower surface 30d of the submount 30 and the bonding region 14a (see FIG. 6). A portion of the bonding material protrudes from the lower surface 30d to form a bonding member 35.

[0063] The bonding material preferably has a high melting point and a low bonding temperature. For example, a bonding material containing metal nanoparticles or metal submicron particles and an organic solvent can be used. Furthermore, for example, a paste containing gold metal particles (hereinafter referred to as metal paste) is preferably used. Metal paste containing metal particles such as silver or copper can also be used. The viscosity of the metal paste ranges, for example, from 50 to 150 Pa·s. When a bonding material containing an organic solvent is used as the bonding material, the organic solvent volatilizes during the curing process of the bonding material. Therefore, the bonding layer 39 and bonding member 35 formed by the bonding material can be primarily made of metal.

[0064] The bonding member 35 is formed along one or more lower side surfaces 30y of the submount 30. The bonding member 35 has a first bonding portion 35a and a second bonding portion 35b. The first bonding portion 35a is formed along one or two of the pair of lower side surfaces 30y extending in the X-axis direction. The second bonding portion 35b is formed along one or two of the pair of lower side surfaces 30y extending in the Z-axis direction. The second bonding portion 35b is formed along the second side surfaces 30b. The first bonding portion 35a and the second bonding portion 35b each form a raised shape.

[0065] The first side surface 30a of the submount 30 is located on the side of the light-emitting side surface 20e of the light-emitting element 20, intersects with the upper surface 30c of the submount 30, and is spaced upward from the mounting surface 11M of the base 11. In the example shown, part of the bonding material protrudes from the lower surface 30d of the submount 30 in the positive and negative directions of the X axis and the positive and negative directions of the Z axis to form a bonding member 35.

[0066] The bonding member 35 extends beyond the edge 30e where the bottom surface 30d and the second side surface 30b of the submount 30 intersect. Furthermore, as illustrated in FIG. 5, in top view, the bonding member 35 extends beyond the top surface 30c of the submount 30. In top view, the second bonding portion 35b extends beyond the top surface 30c of the submount 30. The second bonding portion 35b contacts the second side surface 30b and forms a shape that is higher than the bonding layer 39. This can increase the bonding strength of the submount 30.

[0067] The bonding material 35 extends beyond the edge where the lower surface 30d of the submount 30 intersects with the lower side surface 30y opposite the second side surface 30b. Furthermore, in top view, the bonding material 35 does not extend beyond the upper side surface 30x opposite the first side surface 30a. Note that the submount 30 may be bonded without the bonding material extending beyond the lower surface 30d.

[0068] 6, an imaginary plane P1 that passes through the edge where the lower surface 30d of the submount 30 intersects with the second side surface 30b and is perpendicular to the mounting surface 11M of the base 11, and an imaginary plane P2 that passes through the edge where the upper surface 30c of the submount 30 intersects with the first side surface 30a and is perpendicular to the mounting surface 11M of the base 11, are respectively indicated by dashed dotted lines. In the illustrated example, the light-emitting side surface 20e of the light-emitting element 20 is located between the planes P1 and P2. Here, "between the planes P1 and P2" includes the planes P1 and P2. Note that the light-emitting side surface 20e of the light-emitting element 20 may protrude beyond the upper surface 30c of the submount 30.

[0069] 11 is an enlarged view of portion X1 in the side view of FIG. 4. In this embodiment, the thickness w1 in the X-axis direction of the side wall portion 12 of the package 10 may be 350 μm or more and 450 μm or less. The distance w2 in the X-axis direction between the first side surface 30a and the second side surface 30b of the submount 30 may be 100 μm or more and 200 μm or less. The distance w3 in the X-axis direction between the side wall portion 12 of the package 10 and the first side surface 30a of the submount 30 may be 50 μm or more and 100 μm or less. The width w4 in the X-axis direction of the second bonding portion 35b may be 100 μm or more and 300 μm or less. The thickness t1 in the Y-axis direction of the second submount 32 may be 100 μm or more and 400 μm or less.

[0070] The closer the second side surface 30b is to the light-emitting side surface 20e of the light-emitting element 20, the more effective the heat dissipation effect of the submount 30 becomes. On the other hand, if it is too close, the bonding material is more likely to protrude outside the submount 30, and the distance from the light-emitting side surface 20e to the side wall portion 12 becomes longer. For mounting accuracy, it is desirable to have a small gap between the light-emitting side surface 20e and the cap 16, and it can be said that keeping the protruding bonding material within this gap is preferable for miniaturizing the light-emitting device 100.

[0071] In the light emitting device 100, one or more wires 70 are bonded to the wiring region 14 of the package 10 and the semiconductor laser element 20.

[0072] As shown in FIG. 5, the wiring 70 electrically connected to the first light emitting element 20 located in the center among the three light emitting elements 20 is joined to the wiring region 14d.

[0073] Of the three light emitting elements 20, the wiring 70 electrically connected to the second light emitting element 20 located in the negative direction of the Z axis from the first light emitting element 20 is joined to the wiring region 14c.

[0074] Of the three light emitting elements 20, the wiring 70 electrically connected to the third light emitting element 20 located in the positive direction of the Z axis from the first light emitting element 20 is joined to the wiring region 14b.

[0075] In this embodiment, the submount 30 is not limited to the above-described shape and may have various other shapes.

[0076] 12A, the step structure does not have to be formed along the entire periphery of the side surface like the submount 30. The submount 30_1 has a step structure below the first side surface 30a.

[0077] As shown in Fig. 12B, a slope may be provided instead of the step structure. In this example, there is no surface corresponding to the lower surface 30f of the submount 30, and the second side surface 30b connects to the first side surface 30a and the lower surface 30d. The second side surface 30b forms an inclined surface that is inclined at a predetermined angle with respect to the lower surface 30d.

[0078] Even with these submounts, it is possible to ensure space for escape of some of the bonding material that bonds the base 11 and the submount 30. Note that, rather than the first side surface 30a and the second side surface 30b intersecting as in Fig. 12B, the overflowing bonding material is less likely to spill out from the first side surface 30a when the first side surface 30a and the second side surface 30b do not intersect as in Fig. 9B and Fig. 12A.

[0079] In the light emitting device 100, the plurality of light emitting elements 20 emit light laterally. The light emitted from the light emitting side surface 20e travels along an optical axis parallel to the mounting surface 11M. The light emitted from the light emitting elements 20 passes through the side wall 12 of the package 10 and is emitted laterally from the light-transmitting region 13.

[0080] In the light emitting device 100, a sealed closed space is created inside the package 10. Furthermore, by bonding the substrate 15 and the cap 16 under a predetermined atmosphere, a hermetically sealed closed space is created inside the package 10. In the case of a light emitting element 20 such as a semiconductor laser element, quality degradation due to dust collection can be suppressed by hermetically sealing the space in which the light emitting element 20 is disposed.

[0081] The central axis of the light extracted from the exit surface 10a is perpendicular to the exit surface 10a. Here, perpendicular includes a difference of ±5 degrees. The central axis of the light does not necessarily have to be perpendicular to the exit surface 10a.

[0082] According to the light emitting device 100 of this embodiment, a space for allowing some of the bonding material to escape can be secured between the submount 30 and the mounting surface 11M of the base 11. This allows the submount 30 to be closer to the side wall 12 of the cap 16, and the light emitting device 100 can be made smaller.

[0083] (Second embodiment) The light emitting device 101 according to the second embodiment differs from the light emitting device 100 according to the first embodiment in that a recess is formed on the side surface of the submount. The following mainly describes the differences from the light emitting device 100 according to the first embodiment.

[0084] A light emitting device 101 according to this embodiment will be described with reference to FIGS.

[0085] FIG. 13 is a perspective view of the light-emitting device 101 with the cap 16 of the package 10 removed. FIG. 14 is a rear view of the light-emitting device 101 as viewed from the positive direction of the X-axis in FIG. 13. FIG. 15 is a side view of the light-emitting device 101 as viewed from the negative direction of the Z-axis in FIG. 13. In FIGS. 14 and 15, a portion of the side surface of the cap 16 is shown in a see-through manner so that the semiconductor laser element 20 inside the package 10 can be seen. FIG. 16 is a top view of the light-emitting device 101 with the cap 16 of the package 10 removed. In FIG. 16, a representative light ray included in the main portion of the laser light LB emitted from the semiconductor laser element 20 is indicated by a dashed line. FIG. 17 is a perspective view of the base 11. FIG. 18 is a perspective view of the submount 30_4. FIG. 19A is a rear view of the submount 30_4 as viewed from the positive direction of the X-axis in FIG. 18. Fig. 19B is a side view of the submount 30_4 as viewed from the negative direction of the Z axis in Fig. 18. Fig. 20 is an exploded perspective view of the submount 30_4. Fig. 21 is an enlarged view of a portion X2 in the side view of Fig. 15. Note that a perspective view of the light-emitting device 101 is shown in Fig. 1.

[0086] (Base 11_4) The shape of the wiring region 14b of the base 11_4 is different from that of the wiring region 14b of the base 11. The wiring region 14 of the base 11_4 includes the wiring region 14b and the wiring region 14c having convex regions that protrude toward the bonding region 14a.

[0087] (Submount 30_4) The submount 30_4 is provided with one or more recesses 30s. The recesses 30s define a recess extending from the upper side surface 30x toward the inside of the submount 30_4. The recess defined by the recesses 30s penetrates the submount 30_4 in a top view. The first submount 31 has one or more recesses 30s. The second submount 32 does not have any recesses 30s.

[0088] The one or more recesses 30s form a recessed shape on the outer periphery of the upper surface 30c of the submount 30_4 in a top view. The one or more recesses 30s include one or more recesses 30s provided on each of two upper side surfaces 30x that intersect with the first side surface 30a of the submount 30_4. The one or more recesses 30s include one or more recesses 30s provided on each of the upper side surfaces 30x opposite the first side surface 30a. The one or more recesses 30s do not intersect with the first side surface 30a. In the submount 30_4, no recessed shape extending from the first side surface 30a toward the inside of the submount 30_4 is formed.

[0089] In the illustrated example, among the multiple upper side surfaces 30x of the submount 30_4, the first side surface 30a is referred to as the first surface, the side opposite the first side surface 30a and which is flat is referred to as the second surface, the side perpendicular to the first side surface 30a in a top view and which is flat is referred to as the third surface, and the side perpendicular to the first side surface 30a in a top view and which is flat but not coplanar with the third surface is referred to as the fourth surface. The light-emitting device 101 has one first surface, three second surfaces, two third surfaces, and two fourth surfaces. The multiple upper side surfaces 30x also include side surfaces of one or more recesses 30s.

[0090] In the illustrated example, the submount 30_4 is provided with a plurality of recesses 30s. The plurality of recesses 30s includes recesses 30s that intersect with two second surfaces. These recesses 30s can be considered as recesses 30s that connect the two second surfaces. The plurality of recesses 30s includes recesses 30s that intersect with two third surfaces. These recesses 30s can be considered as recesses 30s that connect the two third surfaces. The plurality of recesses 30s includes recesses 30s that intersect with two fourth surfaces. These recesses 30s can be considered as recesses 30s that connect the two third surfaces. The plurality of recesses 30s includes recesses 30s that intersect with the second surface and the third surface. These recesses 30s can be considered as recesses 30s provided at the corners of the submount 30_4. The plurality of recesses 30s includes recesses 30s that intersect with the second surface and the fourth surface. This recess 30s can be said to be a recess 30s provided in a corner of the submount 30_4.

[0091] The recess 30s is preferably formed in a tapered shape so as to taper downward from the upper surface 30c of the first submount 31. By forming the recess 30s in a tapered shape, it becomes easier to form a metal film in the recess 30s, as will be described later. The recess 30s can be formed in the side surface of the submount 30_4 by, for example, blasting or laser processing.

[0092] Comparing the submount 30 and the submount 30_4, recesses 30s are provided in the submount 30_4 so as to hollow out a part of the wiring region 34 formed in the submount 30. In the submount 30_4, one or more recesses 30s intersect with the wiring region 34.

[0093] A conductive region 30t is provided on the side surface of the recess 30s. The conductive region 30t can be formed by providing a metal film such as Au. The conductive region 30t in the recess 30s is connected to the wiring region 34. Therefore, the conductive region 30t and the wiring region 34 are electrically connected.

[0094] (Conductive member 75) The conductive member 75 is formed using a conductive paste material having electrical conductivity. As the conductive paste material, it is preferable to use a metal paste such as Au, Ag, or Cu, which has a high melting point and a low bonding temperature. The conductive member 75 can be formed by sintering such a conductive paste material at a relatively low temperature (e.g., 200°C). For example, by using a gold paste as the conductive paste material, damage to the semiconductor laser element 20 or its influence on the temperature characteristics can be reduced.

[0095] (Light emitting device 101) In the light emitting device 101, the bonding between the base 11_4 and the submount 30_4, the mounting of the light emitting element 20 on the submount, and the bonding of the cap 16 to the base 11_4 are the same as those described for the light emitting device 100. The light emitting device 101 differs from the light emitting device 100 mainly in the method of wiring connection that realizes the electrical connection of the light emitting element 20.

[0096] In the light emitting device 101, the wiring region 14 of the base 11_4 and the wiring region 34 of the submount 30_4 are electrically connected by using the conductive member 75. This electrical connection is achieved by adhering the conductive member 75 arranged on the wiring region 14 to the conductive region 30t provided in the recess 30s of the submount 30_4.

[0097] The light emitting device 101 has one or more conductive members 75. The one or more conductive members 75 are arranged on the wiring region 14. The conductive member 75 contacts the wiring region 14 and also contacts the conductive region 30t of the submount 30_4. The conductive member 75 contacts the side surface of the recess 30s of the submount 30_4. The conductive member 75 contacts the lower surface 30f of the submount 30_4 and the side surface of the recess 30s. The conductive member 75 does not contact the lower side surface 30y of the submount 30_4. The conductive member 75 does not contact the bonding member 35.

[0098] Conductive members 75 are arranged corresponding to the light emitting device 101 or each of the plurality of recesses 30s. The conductive members 75 have a shape larger than the hollow shape formed by the recesses 30s in a top view. This makes it easier to bring the conductive members 75 into contact with the conductive regions 30t of the submount 30_4.

[0099] In this way, by electrically connecting the base 11_4 and the light-emitting element 20 using the conductive member 75, the area in which the wiring region 14 of the base 11_4 extends beyond the submount 30_4 when viewed from above can be reduced, which can contribute to the miniaturization of the light-emitting device 101.

[0100] The conductive member 75 can also function as a joining member that joins the base 11_4 and the submount 30_4 to fix the submount 30_4 to the mounting surface 11M of the base 11_4. The conductive member 75 can improve the bonding strength between the base 11_4 and the submount 30_4.

[0101] As illustrated in FIG. 21 , in the light emitting device 101 according to this embodiment, the thickness w1 in the X-axis direction of the sidewall 12 of the package 10 may be 350 μm or more and 450 μm or less. The distance w2 in the X-axis direction between the first side surface 30a and the second side surface 30b of the submount 30_4 may be 100 μm or more and 200 μm or less. The distance w3 in the X-axis direction between the sidewall 12 of the package 10 and the first side surface 30a of the submount 30 may be 50 μm or more and 100 μm or less. The size W4 in the X-axis direction of the conductive member 75 may be 200 μm or more and 450 μm or less. The insulating gap w5 in the X-axis direction between the conductive member 75 and the bonding member 35 may be 50 μm or more and 200 μm or less. The size W6 in the X-axis direction of the opening of the recess 30s may be 150 μm or more and 400 μm or less. The thickness t1 in the Y-axis direction of the second submount 32 included in the submount 30_4 may be 100 μm or more and 400 μm or less. The height t2 in the Y-axis direction of the conductive member 75 may be approximately 150 μm or more and 450 μm or less.

[0102] An example of a method for manufacturing the light emitting device 101 according to this embodiment will now be described.

[0103] An example of a manufacturing method of the light emitting device 101 includes forming one or more recesses 30s on the outer periphery of the upper surface of the submount 30_4 (step 1), forming a wiring region 34 on the upper surface 30c of the submount 30_4 (step 2), forming a wiring region 14 on the mounting surface 11M of the base 11 (step 3), applying a paste material to the mounting surface 11M of the base 11 and / or the lower surface 30d of the submount 30_4 (step 4), and sintering the paste material to form a wiring region 14 on the mounting surface 11M of the base 11 and / or the lower surface 30d of the submount 30_4. The method includes joining the submount 30_4 to the mounting surface 11M of the base 11 by forming a bonding layer between the lower surface 30d of the submount 30_4 and the lower surface 30d of the submount 30_4 (step 5); and electrically connecting the wiring region 34 formed on the upper surface 30c of the submount 30_4 and the wiring region 14 formed on the mounting surface 11M of the base 11 by sintering the conductive paste material to form one or more conductive members 75 that contact one or more recesses 30s formed on the outer periphery of the upper surface 30c of the submount 30_4 (step 6).

[0104] In the above step 4, a metal paste such as gold paste can be used as the paste material. In the above step 5, an example of the sintering temperature range is 200°C or higher but lower than 300°C. For example, by sintering the metal particles contained in the paste material within this temperature range for about 30 minutes, a bonding layer can be formed between the mounting surface 11M of the base 11 and the lower surface 30d of the submount 30_4. In the above step 6, an example of the sintering temperature range is 200°C or higher but lower than 300°C. For example, by sintering the metal particles contained in the conductive paste material within this temperature range for about 30 minutes, one or more conductive members 75 can be formed. Note that the materials for the bonding material and the conductive members 75 should be selected to have an appropriate bonding temperature so as not to destroy the bonds already formed in the previous step.

[0105] (Third embodiment) The light emitting device 102 according to the third embodiment differs from the light emitting device 100 or 101 according to the first or second embodiment in that a recess is provided on the side surface of the submount 30_5, which does not have a step structure. The following mainly describes the differences from the light emitting device 100 or 101 according to the first or second embodiment.

[0106] 22 is a perspective view of the light emitting device 102 with the cap 16 of the package 10 removed. The perspective view of the light emitting device 102 is shown in FIG.

[0107] The light emitting device 102 includes at least one light emitting element 20, a submount 30_5 having an upper surface 30c on which the light emitting element 20 is disposed, a base 11 having a mounting surface 11M to which the submount 30_5 is fixed, and one or more conductive members 75 that electrically connect the submount 30_5 and the base 11. The submount 30_5 has one or more recesses 30s. The conductive members 75 are in contact with the mounting surface 11M of the base 11 and the recesses 30s of the submount 30_5, respectively. The one or more recesses 30s form depressions on the outer periphery of the upper surface 30c of the submount 30_5 in a top view.

[0108] The submount 30_5 does not have a structure having an upper side surface 30x and a lower side surface 30y, as in the submounts described so far. The shape of the submount 30_5 is the same as that of the first submount 31 of the second embodiment, except for the difference in thickness. Therefore, among the descriptions of the submount 30_4 of the second embodiment, the contents that can be identified as descriptions of the first submount 31 also apply to the submount 30_5. However, since the submount 30_5 does not have a portion corresponding to the second submount 32, the descriptions of the first submount 31 related to the second submount 32 do not apply.

[0109] In the submount 30_5, the bonding material that bonds the submount 30_5 to the base 11 protrudes from the first surface but does not protrude from the third and fourth surfaces. For example, the base 11 can be prevented from protruding from the third and fourth surfaces by providing grooves on the upper surface of the base 11 in the regions between the bonding region 14a and the third surface and between the bonding region 14a and the third surface. A conductive member 75 is bonded to one or more recesses 30s of the submount 30_5, and the conductive member 75 does not contact the bonding member 35. Similar to the light emitting devices 100 and 101 described above, the light emitting device 102 can also realize a small-sized light emitting device.

[0110] Although several embodiments of the present invention have been described above, the light-emitting device according to the present invention is not strictly limited to the light-emitting device of each embodiment. In other words, the present invention can be realized without being limited to the external shape and structure of the light-emitting device disclosed in each embodiment. Furthermore, the present invention may be applied without necessarily including all necessary and sufficient components. For example, if the claims do not recite some of the components of the light-emitting device disclosed in the embodiments, the claims allow for the design freedom of those components by those skilled in the art, such as substitution, omission, modification of shape, and change of material, and specify that the invention described in the claims applies. [Industrial Applicability]

[0111] The light emitting device according to the embodiment can be used in head-mounted displays, projectors, lighting, displays, and the like. [Explanation of symbols]

[0112] 10: Package 10a: Output surface 11, 11_4: Base 11M: Mounting surface 11P: Peripheral area 12: Side wall 13: Translucent area 14:Wiring area 15: Circuit board 16: Cap 20: Light emitting element (semiconductor laser element) 20e: Exit side 30, 30_4, 30_5: Submount 30a: 1st side 30b: 2nd side 30c, 30g:Top surface 30d, 30f: Bottom surface 30e, 30h: Edge 30s: recess 30t: Conductive area 30x: Upper side 30y: Lower side 31: First submount (first part) 32: Second submount (second part) 34:Wiring area 35: Joint material 39: Bonding layer 70: Wiring 75: Conductive material 100, 101, 102: Light-emitting device LB: Laser light

Claims

1. The top surface and The underside and a first side surface that intersects with the upper surface and does not intersect with the lower surface; a second side surface located on the same side as the first side surface, intersecting with the lower surface and not intersecting with the upper surface; a third side surface that is a side surface opposite to the first side surface and intersects with the upper surface but does not intersect with the lower surface; a fourth side surface located on the same side as the third side surface, intersecting with the lower surface and not intersecting with the upper surface; and A submount, wherein a first distance from a position where the upper surface and the first side intersect to a position where the lower surface and the second side intersect is shorter than a second distance from a position where the upper surface and the third side intersect to a position where the lower surface and the fourth side intersect.

2. a fifth side and a sixth side that intersect with the first side and the third side, respectively; a seventh side and an eighth side that intersect with the second side and the fourth side, respectively; and 2. The submount of claim 1, wherein a ratio of a fourth distance from a position where the upper surface intersects with the seventh side surface to a position where the lower surface intersects with the eighth side surface to a third distance from a position where the upper surface intersects with the fifth side surface to a position where the lower surface intersects with the sixth side surface is smaller than a ratio of the second distance to the first distance.

3. one or more recesses defining an inward recess from the third side; The submount according to claim 1 , wherein the one or more recesses are provided between an imaginary plane including the third side surface and an imaginary plane including the fourth side surface.

4. The submount of claim 3 , wherein the first side is free of any recess that defines a recess inwardly from the first side.

5. The submount according to claim 1 , wherein the first distance is not less than 100 μm and not more than 200 μm.

6. The submount according to claim 1 , wherein the second distance is 1.5 times or more and 3.0 times or less the first distance.

7. A submount according to any one of claims 1 to 6; one or more light emitting devices disposed on the submount; a base having a mounting surface to which the submount is fixed; Equipped with a bonding layer made of a bonding material is formed between the mounting surface of the base and the lower surface of the submount; a part of the bonding material protrudes from the lower surface and reaches outside an edge where the lower surface and the second side surface intersect.

8. the one or more light-emitting elements have an emission side surface from which light is emitted, The light emitting device according to claim 7 , wherein the first side surface is located on the side of the light emitting side surface of the one or more light emitting elements.

9. The light emitting device according to claim 7 , wherein a portion of the bonding material protrudes from the lower surface and reaches outside an edge where the lower surface intersects with the fourth side surface.

10. a portion of the bonding material protruding from the lower surface of the submount in the top view reaches outside an edge where the upper surface of the submount intersects with the first side surface, 10. The light-emitting device according to claim 7, wherein, in the top view, a portion of the bonding material that protrudes from the lower surface of the submount does not reach outside the edge where the upper surface of the submount intersects with the third side surface.

Images