Light emitting device manufacturing method and light emitting device
The light emitting device efficiently attaches a lens by using a bonding material and laser heating, addressing the issue of misalignment and enhancing the device's reliability and performance.
Patent Information
- Application Number
- JP2021068421
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-04-14
- Publication Date
- 2025-04-03
- Estimated Expiration
- 2041-04-14
AI Technical Summary
There is a need for a light emitting device capable of efficiently attaching a lens, as slight misalignments between the semiconductor light emitting element and the lens can significantly shift the direction of the optical axis of light emitted from the device.
The method involves preparing a substrate with a semiconductor light emitting element and a lens support portion, connecting the lens to the lens support portion via a bonding material, and bonding them by incident laser light on the lens support portion to heat the bonding material.
This approach allows for efficient mounting of the lens, preventing shifts and ensuring accurate alignment of the optical axis, thereby enhancing the reliability and performance of the light emitting device.
Smart Images

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Abstract
Description
[Technical field]
[0001] The present disclosure relates to a method for manufacturing a light emitting device, and to a light emitting device. [Background technology]
[0002] Light-emitting devices including semiconductor light-emitting elements are used for various purposes such as processing, projectors, and lighting equipment. A typical example of such a light-emitting device includes a semiconductor light-emitting element, a submount that supports the semiconductor light-emitting element, and a collimating lens that reduces the spread angle of light emitted from the semiconductor light-emitting element (for example, Patent Document 1). Since a slight misalignment between the semiconductor light-emitting element and the lens can cause a large misalignment of the optical axis of the light emitted to the outside from the light-emitting device, it is necessary to attach the lens efficiently in a short time so as not to misalign the lens. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] JP 2000-98190 A Summary of the Invention [Problem to be solved by the invention]
[0004] There is a need for a lighting device that can efficiently mount a lens. [Means for solving the problem]
[0005] In one embodiment, a manufacturing method for a light emitting device disclosed herein includes the steps of preparing a substrate supporting a semiconductor light emitting element and a lens support portion, and a lens, connecting the lens and the lens support portion via a bonding material, and bonding the lens and the lens support portion by applying laser light to the lens support portion to heat the bonding material.
[0006] The light emitting device of the present disclosure comprises a substrate having an upper surface, a semiconductor light emitting element provided directly or indirectly on the upper surface and having an emission surface, one or more lens support parts formed from a light-transmitting material and located near the emission surface and having an end surface, and a lens bonded to the end surface via a bonding material, wherein the lens support part has a wide portion that becomes wider toward the semiconductor light emitting element as it approaches the end surface, and the wide portion has an inner surface located on the side of the semiconductor light emitting element, a reflective member provided on the inner surface, an outer surface located on the opposite side to the semiconductor light emitting element, and a light diffusing part provided on the outer surface or the inner surface.
[0007] The light emitting device of the present disclosure also comprises a substrate having an upper surface, a semiconductor light emitting element provided directly or indirectly on the upper surface and having an emission surface, one or more lens support parts provided on the upper surface, positioned in the vicinity of the emission surface and having an end surface, and a lens bonded to the end surface via a bonding material, wherein the lens support part has a recess, and a light absorbing member is provided in the recess or between the end surface and the lens. Effect of the Invention
[0008] According to the present disclosure, it is possible to realize a light emitting device to which a lens can be efficiently attached. [Brief description of the drawings]
[0009] [Figure 1A] FIG. 1A is a perspective view illustrating a schematic configuration of a light emitting device according to a first exemplary embodiment of the present disclosure. [Figure 1B] FIG. 1B is a diagram showing a schematic planar configuration of the inside of the light emitting device of FIG. 1A. [Figure 2A] FIG. 2A is an exploded perspective view showing in more detail the configuration of the light emitting device of FIG. 1A with the package, lead terminals, and wires omitted. [Figure 2B] FIG. 2B is a top view that illustrates a schematic configuration of the light emitting device of FIG. 1A with the package, lead terminals, and wires omitted. [Figure 2C]FIG. 2C is a cross-sectional view of the configuration of FIG. 2B taken along line IIC-IIC parallel to the YZ plane. [Figure 3A] FIG. 3A is a diagram for explaining an example of a step in the manufacturing method of embodiment 1. FIG. [Figure 3B] FIG. 3B is a view for explaining an example of a step in the manufacturing method of embodiment 1. [Figure 3C] FIG. 3C is a view for explaining an example of a step in the manufacturing method according to the first embodiment. [Figure 3D] FIG. 3D is a view for explaining an example of a step in the manufacturing method according to the first embodiment. [Figure 3E] FIG. 3E is a view for explaining an example of a step in the manufacturing method according to the first embodiment. [Figure 3F] FIG. 3F is a view for explaining an example of a step in the manufacturing method of embodiment 1. [Figure 3G] FIG. 3G is a view for explaining an example of a step in the manufacturing method of embodiment 1. [Figure 3H] FIG. 3H is a view for explaining an example of a step in the manufacturing method according to the first embodiment. [Figure 3I] FIG. 3I is a view for explaining an example of a step in the manufacturing method of the first embodiment. [Figure 4A] FIG. 4A is an exploded perspective view illustrating a configuration of a second exemplary embodiment of the present disclosure. FIG. [Figure 4B] FIG. 4B is a top view diagrammatically illustrating a configuration of the second exemplary embodiment of the present disclosure. [Figure 4C] FIG. 4C is a cross-sectional view of the configuration of FIG. 4B taken along line IVC-IVC parallel to the YZ plane. [Diagram 5] FIG. 5 is a diagram for explaining an example of steps in the manufacturing method according to the second embodiment. [Figure 6A] FIG. 6A is an exploded perspective view illustrating a schematic configuration of a first modified example of the second embodiment. FIG. [Figure 6B] FIG. 6B is an exploded perspective view illustrating a schematic configuration of Modification 2 of Embodiment 2. As shown in FIG. [Figure 6C]FIG. 6C is an exploded perspective view illustrating a schematic configuration of Modification 3 of Embodiment 2. As shown in FIG. [Figure 7A] FIG. 7A is an exploded perspective view illustrating a configuration of a third exemplary embodiment of the present disclosure. FIG. [Figure 7B] FIG. 7B is a top view diagrammatically illustrating the configuration of the third exemplary embodiment of the present disclosure. [Figure 7C] FIG. 7C is a cross-sectional view of the configuration of FIG. 7B taken along line VIIC-VIIC parallel to the YZ plane. [Figure 8A] FIG. 8A is a diagram for explaining an example of a step in the manufacturing method according to the third embodiment. [Figure 8B] FIG. 8B is a view for explaining another example of a step in the manufacturing method according to the third embodiment. [Figure 9A] FIG. 9A is an exploded perspective view showing a schematic configuration of a modified example of the third embodiment. [Figure 9B] FIG. 9B is a top view illustrating a schematic configuration of a modified example of the third embodiment. [Figure 10A] FIG. 10A is an exploded perspective view illustrating a configuration of the fourth exemplary embodiment of the present disclosure. FIG. [Figure 10B] FIG. 10B is a top view diagrammatically illustrating the configuration of the fourth embodiment. [Figure 10C] FIG. 10C is a cross-sectional view of the configuration of FIG. 10B taken along line XC-XC parallel to the YZ plane. [Figure 11] FIG. 11 is a diagram for explaining an example of steps in the manufacturing method according to the fourth embodiment. [Figure 12] FIG. 12 is an exploded perspective view illustrating a configuration of a light emitting device according to the fifth exemplary embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] Hereinafter, a method for manufacturing a light emitting device and a light emitting device according to an embodiment of the present disclosure will be described with reference to the drawings. Parts that appear in multiple drawings with the same reference numerals indicate the same or equivalent parts.
[0011] Furthermore, the following are examples to embody the technical ideas of the present invention, and the present invention is not limited to the following. Furthermore, the description of the dimensions, materials, shapes, relative positions, etc. of the components is intended to be illustrative, and not to limit the scope of the present invention. The sizes and positional relationships of the components shown in each drawing may be exaggerated to make it easier to understand.
[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 polygon have been rounded, chamfered, corner-removed, rounded, etc. Moreover, shapes in which processing has been applied not only to the corners (edges of the sides) but also to the middle parts of the sides are also referred to as polygons. In other words, shapes in which partial processing has been applied while leaving the polygon as the base are included in the interpretation of "polygon" described in this specification and claims.
[0013] In addition, in this specification or claims, when there are multiple elements that correspond to a certain element and each element needs to be expressed separately, the elements may be distinguished by adding "first" or "second" to the beginning of the element. If the objects or viewpoints distinguished between this specification and the claims are different, the same addition may not refer to the same object between this specification and the claims.
[0014] (Embodiment 1) First, an example of a light emitting device according to a first embodiment of the present disclosure will be described with reference to Figures 1A to 2C. A manufacturing method of the light emitting device will be described later.
[0015] Fig. 1A is a perspective view showing a schematic configuration of a light emitting device 100 according to a first exemplary embodiment of the present disclosure. The light emitting device 100 shown in Fig. 1A includes an edge-emitting laser diode that is not visible from the outside, elements or components such as a lens, a package 50 that houses them, and a lead terminal 60 that passes through the package 50 and supplies power to the laser diode. The package 50 includes a lid 50L, a base 50b, and a light-transmitting window 50w.
[0016] FIG. 1B is a diagram showing a schematic planar configuration of the inside of the light emitting device 100 of FIG. 1A. In FIG. 1B, the lid 50L is omitted. As shown in FIG. 1B, the light emitting device 100 includes a substrate 10, a laser diode 20, a submount 22, a lens support 30, a lens 40, and a wire 60w housed in a base 50b. The base 50b includes a bottom plate portion including an inner bottom surface 50bt, and a member 50m provided on the inner bottom surface 50bt. The member 50m supports the substrate 10. The light emitted from the laser diode 20 and passing through the lens 40 is taken out from the light transmitting window 50w.
[0017] In the drawings, for reference, mutually orthogonal X-axis, Y-axis, and Z-axis are shown diagrammatically. The direction of the arrow of each axis is referred to as the + direction, and the opposite direction is referred to as the - direction. For ease of explanation, in this disclosure, the +Y direction is also expressed as "upward", the -Y direction as "downward", the +Z direction as "forward", and the -Z direction as "rearward". This does not limit the orientation of the light emitting device 100 during use, and the orientation of the light emitting device 100 is arbitrary.
[0018] FIG. 2A is an exploded perspective view showing a more detailed configuration of the light emitting device 100 of FIG. 1A with the package 50, the lead terminal 60, and the wire 60w omitted. The light emitting device 100A shown in FIG. 2A includes a substrate 10, a laser diode 20, a submount 22, a lens support 30, and a lens 40. In FIG. 2A, the lens support 30 and the lens 40 are shown in a separated state, but in reality, they are joined together. FIG. 2B is a top view showing the light emitting device 100A of FIG. 2A. FIG. 2C is a cross-sectional view of the configuration of FIG. 2B taken along line IIC-IIC parallel to the YZ plane.
[0019] Each component will be described below, with details of the material and size of each component being described later.
[0020] As shown in FIG. 2A, the substrate 10 has a top surface 10s that is parallel to the XZ plane. The normal direction of the top surface 10s is the +Y direction. In this specification, the view from the normal direction of the top surface 10s is referred to as "top view". The laser diode 20 is indirectly provided on the top surface 10s of the substrate 10 via a submount 22. The laser diode 20 may be directly provided on the top surface 10s of the substrate 10. In the example shown in FIG. 2A, the laser diode 20 is a rectangular parallelepiped extending in the Z direction. The laser diode 20 has an emission surface 20e on a part of the front end surface of two end surfaces that intersect with the Z direction. The laser diode 20 emits laser light from the emission surface 20e toward the +Z direction. The laser light spreads at different speeds in the YZ plane and the XZ plane as it travels in the +Z direction. The laser light spreads relatively quickly in the YZ plane and relatively slowly in the XZ plane. When the laser light spot is not collimated, it has an elliptical shape in the far field with the major axis in the Y direction and the minor axis in the X direction in the XY plane. Note that a light emitting diode that emits incoherent light may be used instead of the laser diode 20. In this specification, a light emitting element formed from a semiconductor material such as a laser diode or a light emitting diode is referred to as a "semiconductor light emitting element."
[0021] As shown in FIG. 2A, the lens support 30 is provided on the upper surface 10s of the substrate 10. The lens support 30 supports the lens 40 by means of two rectangular end surfaces 30s. In the X direction, the lens support 30 is located on both sides of the laser diode 20. In the Y direction, the lower surface of the laser diode 20 is higher than or at the same position as the lower surface of the lens support 30, and the upper surface of the laser diode 20 is lower than the upper surface of the lens support 30. When viewed from the Z direction, the emission surface 20e of the laser diode 20 is higher than the lower side of the end surface 30s of the lens support 30 and lower than the upper side in the Y direction.
[0022] As shown in FIG. 2A and FIG. 2B, the lens support part 30 has a straight part 30L and a wide part 30w located in front of the straight part 30L. The straight part 30L is a rectangular parallelepiped extending along the Z direction. The wide part 30w includes an end face 30s, and the width of the wide part 30w in the X direction becomes wider toward the laser diode 20 as it approaches the end face 30s. As shown in FIG. 2B, the wide part 30w has an inner side surface 30ws1 located on the side of the laser diode 20 and an outer side surface 30ws2 located on the opposite side to the laser diode 20. A reflecting member 30r is provided on the inner side surface 30ws1, and a light diffusing part 30d is provided on the outer side surface 30ws2. The reflecting member 30r and the light diffusing part 30d provided on the wide part 30w function when the end face 30s of the lens support part 30 and the lens 40 are joined together during the manufacture of the light emitting device 100A.
[0023] The lens support section 30 may have only a portion located near the emission surface 20e of the laser diode 20. Near means located within a spherical range having a radius of 5 mm or less from the center of the emission surface 20e of the laser diode 20. As shown in FIG. 2A, a plurality of lens support sections 30 may support the lens 40, or a single lens support section may support the lens 40.
[0024] As shown in FIG. 2A, the lens 40 includes a convex lens portion 40a and a flat plate portion 40b. The convex lens portion 40a collimates the laser light emitted from the laser diode 20. The flat plate portion 40b extends along the X direction and supports the convex lens portion 40a. The convex lens portion 40a and the flat plate portion 40b may be integrally formed. Alternatively, the lens 40 may be formed by bonding the convex lens portion 40a and the flat plate portion 40b that are formed separately. In this specification, "collimating" includes not only making the laser light parallel, but also reducing the spread angle of the laser light. As shown in FIG. 2C, the optical axis (broken line) of the laser light emitted from the laser diode 20 coincides with the optical axis of the convex lens portion 40a.
[0025] The convex lens portion 40a has different curvatures in the YZ plane and the XZ plane. The curvature in the YZ plane is relatively large, and the curvature in the XZ plane is relatively small. The convex lens portion 40a having such a curvature can collimate a portion of the laser light that spreads relatively quickly in the YZ plane and a portion that spreads relatively slowly in the XZ plane as it travels. The lens 40 has a focal point on the optical axis behind it. The light emitted from the focal point and incident on the lens 40 is collimated and emitted forward. The center of the emission surface 20e of the laser diode 20 almost coincides with the focal point of the lens 40. In the first embodiment, since the distance between the emission surface 20e of the laser diode 20 and the surface of the lens 40 facing the emission surface 20e is short, the lens 40 can reduce the spread of the laser light emitted from the laser diode 20 before it spreads widely. As a result, a small-sized light-emitting device 100A can be realized.
[0026] Alternatively, the lens 40 may be a cylindrical lens having a curvature in the YZ plane and extending uniformly along the X direction. The cylindrical lens can collimate a portion of the laser light emitted from the laser diode 20 that spreads relatively quickly in the YZ plane. The cylindrical lens is called a FAC (Fast Axis Collimator) lens. Another cylindrical lens having a curvature in the XZ plane and extending uniformly along the Y direction may be provided at a position outside the package 50 and on the optical axis of the laser light. The other cylindrical lens can collimate a portion of the laser light that spreads relatively slowly in the XZ plane. The other cylindrical lens is called a SAC (Slow Axis Collimator) lens.
[0027] Depending on the application, the lens 40 may focus the laser light emitted from the laser diode 20 .
[0028] The end face 30s of the lens support part 30 and the lens 40 are bonded via a bonding material 32. A first metal film 30m may be provided on the end face 30s of the lens support part 30. Similarly, a second metal film 40m may be provided on the surface 40s of the flat plate part 40b of the lens 40 that faces the end face 30s of the lens support part 30. In the Z direction, the first metal film 30m, the bonding material 32, and the second metal film 40m are arranged in this order and are located between the end face 30s of the lens support part 30 and the lens 40. The first metal film 30m and the second metal film 40m can improve the bonding strength between the end face 30s of the lens support part 30 and the lens 40 in the bonding between them via the bonding material 32. Furthermore, in the first embodiment in which the lens support part 30 has the wide portion 30w, the area of the bonding surface between the end face 30s of the lens support part 30 and the lens 40 can be increased compared to a configuration without the wide portion 30w. As a result, the bonding strength between them can be improved.
[0029] The center of gravity of the lens 40 is located between the end faces 30s of the pair of lens support parts 30 in the X direction when viewed from the Z direction. Specifically, the center of gravity of the lens 40 is located higher than the lower side and lower than the upper side of the upper and lower sides of the end faces 30s of the lens support part 30 in the Y direction when viewed from the Z direction. By positioning the center of gravity of the lens 40 in this way, the lens 40 can be stably provided on the end faces 30s of the lens support part 30.
[0030] The lens support 30 and the lens 40 may be formed, for example, from the same light-transmitting material. The light-transmitting material is transmissive to the laser light that heats the bonding material 32 during the manufacture of the light-emitting device 100A. The light transmittance of the light-transmitting material may be, for example, 60% or more, preferably 70% or more, and more preferably 80% or more, for the laser light used for heating. When the lens support 30 and the lens 40 are formed from the same light-transmitting material, they have the same thermal expansion coefficient. Therefore, the heat generated by the laser diode 20 during the operation of the light-emitting device 100A causes the two to thermally expand to the same extent, and it is possible to prevent the bonding between the two from coming apart due to the thermal expansion.
[0031] As shown in FIG. 1B, the base 50b of the package 50 houses the substrate 10, the laser diode 20, the submount 22, the lens support 30, and the lens 40. The package 50 may hermetically seal these components. When the laser diode 20 emits a laser beam of, for example, 350 nm or more and 570 nm or less, organic gas components contained in the atmosphere may be decomposed by the laser beam, and the decomposed products may adhere to the emission surface 20e of the laser diode 20. Furthermore, if the emission surface 20e of the laser diode 20 is exposed to the outside air, the emission surface may deteriorate during operation due to dust collection, for example. These factors may reduce the optical output of the laser diode 20. In order to increase the reliability of the laser diode 20 and extend its life, it is desirable that the package 50 hermetically seals the laser diode 20. The hermetic sealing by the package 50 may be performed regardless of the wavelength of the laser beam emitted from the laser diode 20.
[0032] 1B, the lead terminal 60 is electrically connected to the laser diode 20 via a wire 60w and the submount 22. A current is injected into the laser diode 20 by the lead terminal 60. The lead terminal 60 is electrically connected to an external circuit that adjusts the emission timing and output of the laser light emitted from the laser diode 20.
[0033] A method for manufacturing the light emitting device 100 according to embodiment 1 will be described below with reference to Figures 3A to 3I. Figures 3A to 3I are views for explaining an example of steps in the method for manufacturing the light emitting device 100 according to embodiment 1. Figures 3A to 3D and 3I are perspective views of components, and Figures 3E to 3H are top views of the components.
[0034] In a first step, as shown in FIG. 3A, a substrate 10 having a top surface 10s is prepared. The substrate 10 may be, for example, a rectangular parallelepiped. A part or the whole of the substrate 10 may be formed of, for example, a ceramic including at least one selected from the group consisting of AlN, SiC, and alumina, or an alloy such as CuW. The thermal conductivity of the ceramic may be, for example, 10 [W / m·K] or more and 500 [W / m·K] or less. Such thermal conductivity allows the substrate 10 to efficiently transfer heat generated from the laser diode 20 to the package 50 during operation. The thermal expansion coefficient of the ceramic may be, for example, 2×10 -6 [1 / K] or more 1×10 -5 [1 / K] or less. Such a coefficient of thermal expansion can suppress deformation of the substrate 10 due to heat applied when bonding the submount 22 onto the substrate 10. The dimension of the substrate 10 in the X direction is, for example, 1 mm or more and 3 mm or less, the dimension in the Y direction is, for example, 0.1 mm or more and 0.5 mm or less, and the dimension in the Z direction is, for example, 1 mm or more and 6 mm or less.
[0035] In the next step, as shown in Fig. 3B, the lens support 30 is disposed on the upper surface 10s of the substrate 10. The lens support 30 may be formed from at least one light-transmitting material selected from the group consisting of, for example, glass, silicon, quartz, synthetic quartz, sapphire, transparent ceramic, and plastic.
[0036] Of the lens support part 30, the dimension of the straight part 30L in the X direction is, for example, 0.05 mm or more and 1 mm or less, the dimension in the Y direction is, for example, 0.1 mm or more and 3 mm or less, and the dimension in the Z direction is, for example, 0.1 mm or more and 6 mm or less. Of the lens support part 30, the maximum dimension of the wide part 30w in the X direction is, for example, 0.06 mm or more and 1 mm or less, the dimension in the Y direction is, for example, 0.1 mm or more and 1 mm or less, and the dimension in the Z direction is, for example, 0.1 mm or more and 1 mm or less. The dimension in the Z direction of the lens support part 30 including the straight part 30L and the wide part 30w may be approximately equal to the dimension in the Z direction of the substrate 10, or may be smaller than the dimension in the Z direction of the substrate 10.
[0037] The angle between the inner surface 30ws1 of the wide portion 30w and the end surface 30s may be, for example, 30° or more and 60° or less. The first metal film 30m is formed on the end surface 30s of the lens support unit 30 by, for example, plating. The first metal film 30m may be provided as a single layer or multiple layers. A layer of, for example, Cr or Au may be provided on the outermost surface of the first metal film 30m. When the first metal film 30m is formed as multiple layers, a layer of Cr, Ti, Ni, or the like may be provided as a base layer, and a layer of Pt, Pd, Rt, or the like may be provided as an intermediate layer. The wide portion 30w of the lens support unit 30 includes a reflecting member 30r provided on the inner surface 30ws1 and a light diffusing portion 30d provided on the outer surface 30ws2. The reflecting member 30r may be formed of a metal such as Ag or Al, or a dielectric multilayer film such as Ta2O5 / SiO2, TiO2 / SiO2, or Nb2O5 / SiO2. When a metal such as Ag or Al is used for the reflecting member 30r, a base layer such as Cr, Ti, or Ni may be provided between the lens support unit 30 and the reflecting member 30r. The light diffusing unit 30d may be, for example, a part of the outer surface of the lens support unit 30 that is roughened. The rough surface may be formed by sandblasting, for example, or by pressing a metal mold having irregularities against the lens support unit 30. The entire outer surface of the lens support unit 30 may be roughened, rather than being a part of it. When the lens support unit 30 is prepared by dicing, the entire outer surface of the lens support unit 30 may be roughened. The grain size of the abrasive grains of the dicing blade used in dicing is preferably 200 to 800 grit because it is easy to form a rough surface. The roles of the reflecting member 30r and the light diffusing unit 30d will be described later.
[0038] In the next step, as shown in FIG. 3C, the laser diode 20 is disposed on the upper surface 10s of the substrate 10 via the submount 22. The emission surface 20e of the laser diode 20 and the front end surface 22fs of the submount 22 are located on the same plane parallel to the XY plane. The front end surface 22fs of the submount 22 is located behind the front end surface 10fs of the substrate 10. As a result, the laser diode 20 provided on the submount 22 is located at a predetermined distance from the wide portion 30w. As the predetermined distance, the shortest distance between the laser diode 20 and the wide portion 30w in the top view can be, for example, 0.05 mm or more and 1 mm or less. With this configuration, it is possible to suppress the heat applied to the bonding material 32 in a step described later from being transmitted to the laser diode 20 via the wide portion 30w. As a result, it is possible to suppress the laser diode 20 from being damaged or its operating characteristics from being deteriorated due to heating.
[0039] A metal film is formed by, for example, plating on the upper surface of the laser diode 20 and the upper surface of the submount 22. The metal film provided on both upper surfaces is formed to electrically connect the lead terminal 60 and the laser diode 20 via the wire 60w in a process to be described later.
[0040] The submount 22 may be, for example, a rectangular parallelepiped. If the thermal conductivity of the submount 22 is higher than that of the substrate 10, the heat generated from the laser diode 20 during operation can be efficiently transferred to the substrate 10. The submount 22 may be formed of at least one selected from the group consisting of Cu, Al, Ag, Fe, Ni, Mo, Cu, W, CuW, CuMo, AlN, SiC, and Al2O3. The dimension of the submount 22 in the X direction may be, for example, 0.3 mm or more and 4 mm or less, the dimension in the Y direction may be, for example, 0.1 mm or more and 0.5 mm or less, and the dimension in the Z direction may be, for example, 0.3 mm or more and 5 mm or less.
[0041] The laser diode 20 may be, for example, a rectangular parallelepiped. The dimension of the laser diode 20 in the X direction may be, for example, 50 μm to 500 μm, the dimension in the Y direction may be, for example, 20 μm to 150 μm, and the dimension in the Z direction may be, for example, 50 μm to 4 mm.
[0042] The laser diode 20 may emit violet, blue, green or red laser light in the visible region, or infrared or ultraviolet laser light in the invisible region. The emission peak wavelength of the violet light is preferably in the range of 350 nm to 419 nm, more preferably in the range of 400 nm to 415 nm. The emission peak wavelength of the blue light is preferably in the range of 420 nm to 494 nm, more preferably in the range of 440 nm to 475 nm. Examples of laser diodes that emit violet or blue laser light include laser diodes containing nitride semiconductor materials. Examples of nitride semiconductor materials that can be used include GaN, InGaN, and AlGaN. The emission peak wavelength of the green light is preferably in the range of 495 nm to 570 nm, more preferably in the range of 510 nm to 550 nm. Examples of laser diodes that emit green laser light include laser diodes containing nitride semiconductor materials. Examples of nitride semiconductor materials that can be used include GaN, InGaN, and AlGaN. The emission peak wavelength of the red light is preferably in the range of 605 nm to 750 nm, more preferably in the range of 610 nm to 700 nm. Examples of laser diodes that emit red laser light include laser diodes containing InAlGaP, GaInP, GaAs, and AlGaAs semiconductor materials. Laser diodes with two or more waveguide regions can be used as red laser diodes. Laser diodes containing these semiconductor materials are more susceptible to output reduction due to heat than laser diodes containing nitride semiconductors. By increasing the area of the waveguide region, heat can be dispersed to reduce the output reduction of the laser diode.
[0043] The laser diode 20 includes a semiconductor laminated structure in which an n-type substrate, an n-type cladding layer, an emission layer, and a p-type cladding layer are laminated in this order along the +Y direction or the -Y direction. The n-type and p-type may be reversed. Of the two end faces of the emission layer that intersect in the Z direction, the front end face, i.e., the emission face 20e, emits laser light. The emission face 20e has a rectangular shape extending along the X direction. The laser diode 20 may be mounted in a so-called face-up state in which the substrate is closer to the submount 22 than the emission layer in the semiconductor laminated structure. Alternatively, the laser diode 20 may be mounted in a so-called face-down state in which the emission layer is closer to the submount 22 than the substrate in the semiconductor laminated structure. In the face-down mounting, heat generated by the emission layer during operation can be efficiently transferred to the submount 22. On the other hand, in the face-down mounting, the bonding material used to bond the laser diode 20 to the submount 22 may creep up to the emission face 20e and block the emission face 20e. In face-down mounting, by making the emission surface 20e of the laser diode 20 protrude beyond the front end surface 22fs of the submount 22, it is possible to prevent the bonding material from creeping up onto the emission surface 20e.
[0044] An electrode is provided on each of the upper and lower surfaces of the laser diode 20. The electrode electrically connected to the p-type cladding layer of the laser diode 20 is called the "p-side electrode", and the electrode electrically connected to the n-type substrate is called the "n-side electrode". By applying a voltage to the p-side electrode and the n-side electrode to pass a current equal to or greater than a threshold value, the laser diode 20 emits laser light from the emission surface 20e. The laser light has a spreading property, and forms an elliptical far-field pattern (hereinafter referred to as "FFP") on a plane parallel to the emission surface 20e. The FFP refers to the shape and light intensity distribution of the emitted light at a position away from the emission surface 20e. In this light intensity distribution, the 1 / e 2 Light having an intensity equal to or greater than this is considered to be the main part of the light. e is the base of the natural logarithm.
[0045] The shape of the FFP of the laser light emitted from the laser diode 20 is elliptical. In the elliptical shape, the long axis is parallel to the stacking direction of the semiconductor stacked structure, and the short axis is parallel to the extending direction of the emission surface 20e. The extending direction of the emission surface 20e is the horizontal direction of the FFP, and the stacking direction is the vertical direction of the FFP.
[0046] Based on the light intensity distribution of the FFP, the angle equivalent to the full width at half maximum of the light intensity distribution is defined as the spread angle of the laser light emitted from the laser diode 20. In the FFP, the vertical and horizontal axes are called the fast axis and the slow axis, respectively.
[0047] In the next step, a lens 40 is prepared as shown in Fig. 3D. The material of the lens 40 may be the same as the material of the lens support part 30. A second metal film 40m is formed on the surface 40s of the lens 40 that faces the end face 30s of the lens support part 30, for example, by plating. The material of the second metal film 40m may be the same as the material of the first metal film 30m, for example.
[0048] The dimension of the flat plate portion 40b in the X direction of the lens 40 may be equal to the dimension of the substrate 10 in the X direction, or may be larger or smaller than the dimension of the substrate 10 in the X direction. However, the dimension of the flat plate portion 40b in the X direction is greater than twice the distance in the X direction between the center of the end face 30s and the center of the exit face 20e. The dimension of the flat plate portion 40b in the Y direction may be equal to the dimension of the lens support portion 30 in the Y direction, or may be larger or smaller than the dimension of the lens support portion 30 in the Y direction. The dimension of the flat plate portion 40b in the Z direction may be, for example, 0.05 mm or more and 1 mm or less. In a configuration in which the dimension of the flat plate portion 40b in the Y direction is equal to or larger than the dimension of the lens support portion 30 in the Y direction, the area of the bonding surface between the end face 30s of the lens support portion 30 and the lens 40 can be increased compared to a configuration in which the dimension is not equal to or larger than the dimension of the lens support portion 30 in the Y direction. As a result, the bonding strength between the two can be improved.
[0049] As described above, the substrate 10, the laser diode 20, the lens support 30, and the lens 40 are prepared.
[0050] In the next step, as shown in FIG. 3E, the end face 30s of the lens support 30 and the lens 40 are connected via a bonding material 32. In this connection, the end face 30s of the lens support 30 and the face 40s of the lens 40 facing the end face 30s are substantially parallel. The angle between these faces can be, for example, 0° or more and 10° or less. The bonding material 32 can be formed, for example, from a material that can be soldered. In soldering, the members are joined together by melting the solder by increasing the temperature and solidifying it by decreasing the temperature. Alternatively, the bonding material 32 can be formed, for example, from a material that can be sintered. In sintering, the members are joined together by heating a metal paste containing metal particles or a metal powder at a temperature lower than the melting point of the metal and baking it.
[0051] In the case of soldering, the bonding material 32 may be formed from at least one alloy selected from the group consisting of AuSn, SnCu, SnAg, and SnAgCu. When the alloy has an AuSn-based eutectic composition (Au1:Sn9), its melting point is low, 217°C. When the alloy has an AuSn-based eutectic composition (Au78:Sn22), its melting point is high, 278°C. When the alloy has an SnCu-based or SnAg-based composition, its melting point is low, 210°C to 230°C. The melting point of the alloy corresponds to the bonding temperature of the bonding material 32. Note that the bonding can be performed if the surface of the bonding material 32 melts, so the actual bonding temperature may be lower than the melting point of the alloy. In addition to the above alloys, the bonding material 32 may be formed from an alloy paste containing the above alloys and an organic binder. The organic binder is vaporized when heated.
[0052] In the case of sintering, the bonding material 32 may be formed from a metal paste containing at least one type of particles selected from the group consisting of Ag particles, Cu particles, and Au particles. The sintering temperature is lower than the melting point of the metal constituting the particles, and may be, for example, 120° C. or higher and 300° C. or lower. The sintering temperature corresponds to the bonding temperature of the bonding material 32.
[0053] If the bonding material 32 is too thin, sufficient bonding strength cannot be obtained between the end surface 30s of the lens support part 30 and the lens 40. If the bonding material 32 is too thick, it takes a long time to heat it. From the viewpoint of bonding strength and heating time, the thickness of the bonding material 32 can be, for example, 1 μm or more and 30 μm or less.
[0054] In the next step, as shown in Fig. 3F, a laser beam for heating is incident from the side of the lens support part 30 toward the light diffusion part 30d of the wide part 30w. By incidenting the laser beam from the side of the lens support part 30, the distance that the laser beam travels inside the lens support part 30 is shorter than when the laser beam is incident from the rear of the lens support part 30, so that the laser beam can be incident efficiently. The power density of the laser beam is, for example, 10 kW / cm 2 More than 10000kW / cm 2The irradiation time of the laser light may be, for example, 1 ms or more and 50 ms or less. The white arrows shown in FIG. 3F show a schematic representation of the progression of the laser light. The bent parts of the arrows show the refraction of the laser light. The same applies to the white arrows shown in the following figures. The lens support unit 30 including the wide portion 30w is made of a light-transmitting material, so that the laser light can progress through the inside of the lens support unit 30. The laser light diffused by the light diffusion unit 30d passes through the inside of the wide portion 30w and is incident on the inner surface 30ws1, more specifically, on the reflecting member 30r provided thereon. The widening part of the arrow shows the diffusion of the laser light. Even if the power density of the laser light is high, the laser light can be prevented from concentrating on a part of the reflecting member 30r and damaging the reflecting member 30r by diffusing the laser light by the light diffusion unit 30d. The reflecting member 30r reflects the incident laser light toward the end surface 30s. The end surface 30s of the lens support unit 30 is irradiated with the laser light reflected by the reflecting member 30r. As a result, the bonding material 32 can be heated to bond the end surface 30s of the lens support portion 30 and the lens 40. As described above, the bonding material 32 is heated by irradiating the end surface 30s with the laser light by making the laser light incident on the front portion of the lens support portion 30. The end surface 30s of the lens support portion 30 and the lens 40 can be bonded through the bonding material 32 heated in this manner. The first metal film 30m located between the end surface 30s of the lens support portion 30 and the lens 40 also functions as a light absorbing member. The first metal film 30m absorbs the incident laser light and converts it into heat. This heat also contributes to heating the bonding material 32. When a YAG laser light source is used as a light source that emits laser light for heating, the laser light has a near-infrared wavelength. When a laser light source other than a YAG laser light source is used, the laser light for heating may have a wavelength of visible light such as blue or green, or a wavelength of invisible light such as ultraviolet light.
[0055] During heating, the lens 40 is loaded in a direction perpendicular to the end face 30s, as indicated by the bold arrow in FIG. 3F. Since the surface of the flat plate portion 40b of the lens 40 to be loaded is flat, it is easy to load the lens 40 in a direction perpendicular to the end face 30s. The lens 40 shifts in the direction of the load, for example, by 2 μm or more and 3 μm or less. The lens 40 may be loaded while the laser diode 20 is emitting laser light. The position of the lens 40 can be finely adjusted by the shift caused by the load, and the lens 40 can be attached at a position where the laser light can be accurately collimated.
[0056] In the first embodiment, even if there is variation in the thickness of the bonding material 32, positional deviation in the Y direction between the laser diode 20 and the lens 40 is unlikely to occur, and the optical axis of the laser light emitted to the outside from the light emitting device 100 can be directed in the designed direction. Even if there is some variation in the thickness of the bonding material 32, the position of the lens 40 only changes slightly along the optical axis of the laser light, and therefore the effect of this variation on the direction of the optical axis of the laser light is small.
[0057] In addition, instead of the outer surface 30ws2 of the wide portion 30w as shown in FIG. 3E, the inner surface 30ws1 may be roughened to form the light diffusion portion 30d, and the reflecting member 30r may be provided thereon. Even with such a configuration, the laser light can be diffused and made incident on the reflecting member 30r. If the power density of the laser light for heating is low and there is no risk of damaging the reflecting member 30r, it is not necessary to provide the light diffusion portion 30d. Furthermore, if the incident angle of the laser light incident on the inner surface 30ws1 of the wide portion 30w is greater than the critical angle (for example, 40° or more and 45° or less), the laser light is totally reflected by the inner surface 30ws1 of the wide portion 30w. Therefore, it is not necessary to provide the reflecting member 30r.
[0058] In the next step, as shown in FIG. 3G, the configuration shown in FIG. 3F is provided on a member 50m located on the inside of the base 50b. The member 50m provided on the inside bottom surface 50bt of the base 50b can align the height of the emission surface 20e of the laser diode 20 and the light-transmitting window 50w. The member 50m can be formed from the same material as the bottom plate portion including the inside bottom surface 50bt of the base 50b. Alternatively, the member 50m can be a protruding portion of at least a part of the inside bottom surface 50bt of the base 50b. The bottom plate portion including the inside bottom surface 50bt of the base 50b can be formed from a metal including at least one selected from the group consisting of Cu, Al, Ag, Fe, Ni, Mo, Cu, W, and CuMo, for example. The metal has high thermal conductivity, and the bottom plate portion formed from such a metal can efficiently transfer heat generated from the laser diode 20 to the outside when it is driven. The sidewall portion of the base body 50b surrounds the substrate 10, the laser diode 20, the submount 22, the lens support 30, and the lens 40. The sidewall portion may be made of, for example, kovar. Kovar is an alloy of iron, which is the main component, with nickel and cobalt added.
[0059] In the next step, as shown in FIG. 3H, the lead terminal 60 and the laser diode 20 are electrically connected via the wires 60w and the submount 22. Specifically, one of the lead terminals 60 is electrically connected via three wires 60w to a metal film formed on the upper surface of the laser diode 20, and the other is electrically connected via three wires 60w to a metal film formed on the upper surface of the submount 22. The number of wires 60w does not need to be three, and may be one or two, or may be four or more. The lead terminal 60 may be formed of a conductive material such as an Fe-Ni alloy or a Cu alloy. The wires 60w may be formed of at least one metal selected from the group consisting of Au, Ag, Cu, and Al.
[0060] In the next step, as shown in FIG. 3I, the inside of the base body 50b is hermetically sealed by the lid body 50L. The lid body 50L may be made of the same material as the base body 50b, or may be made of a different material. The light-transmitting window 50w is attached to the base body 50b and transmits the laser light emitted from the laser diode 20 and passed through the lens 40. The material of the light-transmitting window 50w in the package 50 may be the same as the material of the lens 40, for example.
[0061] Through the steps described above with reference to FIGS. 3A to 3I, the light emitting device 100 according to the first embodiment can be manufactured.
[0062] (Embodiment 2) According to the second embodiment, even if the lens support 30 does not have the wide portion 30w, the end surface 30s of the lens support 30 can be irradiated with the heating laser light. An example of a light emitting device according to the second embodiment of the present disclosure will be described below with reference to Figs. 4A to 4C, focusing on the differences between the second embodiment and the first embodiment. Fig. 4A is an exploded perspective view showing a schematic configuration of a light emitting device 100B according to the second exemplary embodiment of the present disclosure. Fig. 4B is a top view showing the light emitting device 100B of Fig. 4A. Fig. 4C is a cross-sectional view of the configuration of Fig. 4B taken along the line IVC-IVC parallel to the YZ plane.
[0063] The light emitting device 100B shown in FIG. 4A differs from the light emitting device 100A shown in FIG. 2A in the configuration of the lens support 30 and the position of the submount 22 on the upper surface 10s of the substrate 10. The lens support 30 has a recess 30c on the outer surface. The lens support 30 has a columnar shape with a part of the outer surface cut out. The part is a cube. As shown in FIG. 4B, the recess 30c has a first surface 30cs1 located on the opposite side of the end surface 30s, a second surface 30cs2 perpendicular to the first surface 30cs1, and a third surface 30cs3 perpendicular to the second surface 30cs2 and facing the first surface 30cs1. The second surface 30cs2 and the third surface 30cs3 are located farther from the end surface 30s than the first surface 30cs1. The first surface 30cs1 or the third surface 30cs3 is approximately parallel to the end surface 30s. The angle between the first surface 30cs1 or the third surface 30cs3 and the end surface 30s may be, for example, 0° or more and 10° or less. The second surface 30cs2 does not necessarily have to be perpendicular to the first surface 30cs1 and the third surface 30cs3. The angle between the second surface 30cs2 and the first surface 30cs1 or the third surface 30cs3 may be, for example, 80° or more and 100° or less. The first surface 30cs1 is located between the end surface 30s and the third surface 30cs3. The dimension of the side of the first surface 30cs1 or the third surface 30cs3 that is parallel to the upper surface 10s may be, for example, 0.5 times or more and 0.8 times or less than the dimension of the end surface 30s in the X direction. The recess 30c functions when the end surface 30s of the lens support part 30 is joined to the lens 40 during the manufacture of the light emitting device 100B. As previously described, the lens haptics 30 and the lens 40 may be formed, for example, from the same optically transparent material.
[0064] As shown in FIG. 4A, the front end surface 22fs of the submount 22 and the front end surface 10fs of the substrate 10 may be located on the same plane parallel to the XY plane. The lens support part 30 in the second embodiment does not have the wide portion 30w in the first embodiment. Therefore, as shown in FIG. 4C, even if the distance between the emission surface 20e of the laser diode 20 and the surface of the lens 40 facing the emission surface 20e is made shorter than that in the first embodiment, the distance between the laser diode 20 and the lens support part 30 does not become shorter. As a result, it is possible to suppress the heat applied to the bonding material 32 during manufacturing from being transferred to the laser diode 20 via the lens support part 30.
[0065] In the second embodiment, compared to the first embodiment, the laser light emitted from the laser diode 20 can be collimated by the lens 40 at an earlier stage, and the divergence of the laser light emitted from the laser diode 20 can be further suppressed. Since the divergence of the laser light incident on the lens 40 is small, the convex lens portion 40a in the second embodiment can be made smaller than the convex lens portion 40a in the first embodiment.
[0066] Hereinafter, a method for manufacturing the light emitting device 100B according to the second embodiment will be described with reference to FIG. 5. FIG. 5 is a diagram for explaining an example of a process in the method for manufacturing the light emitting device 100B according to the second embodiment. The process of preparing the substrate 10, the laser diode 20, the lens support 30, and the lens 40, and the process of connecting the end face 30s of the lens support 30 and the lens 40 via the bonding material 32 have been described with reference to FIGS. 3A to 3E. In the next process after connecting the two, as shown in FIG. 5, a laser beam for heating is incident from the side toward the first surface 30cs1 of the recess 30c. The first surface 30cs1 refracts the incident laser beam toward the end face 30s. The end face 30s of the lens support 30 is irradiated with the laser beam refracted by the first surface 30cs1. As a result, the bonding material 32 is heated, and the end face 30s of the lens support 30 and the lens 40 can be bonded to each other. The first metal film 30m located between the end face 30s of the lens support part 30 and the lens 40 functions as a light absorbing member and applies a load to the lens 40, as described with reference to FIG. 3F.
[0067] Next, with reference to Fig. 6A to Fig. 6C, Modifications 1 to 3 of the light emitting device 100B according to the second embodiment will be described, respectively. Fig. 6A is an exploded perspective view that shows a schematic configuration of a light emitting device 110B according to Modification 1 of the second embodiment. The light emitting device 110B shown in Fig. 6A differs from the light emitting device 100B shown in Fig. 4A in that the lens support part 30 has a recess 30c shown in Fig. 4A on its upper surface. The lens support part 30 has a columnar shape with a part of its upper surface cut out. The part is cubic.
[0068] The manufacturing method of the light emitting device 110B according to the modification of the second embodiment is the same as that of the light emitting device 100B according to the second embodiment, except that the heating laser is incident on the recess 30c from above, not from the side. In the light emitting device 110B according to the modification 1 of the second embodiment, the end face 30s of the lens support part 30 and the lens 40 can also be bonded via the bonding material 32.
[0069] FIG. 6B is an exploded perspective view showing a schematic configuration of a light emitting device 120B according to Modification 2 of the second embodiment. The light emitting device 120B shown in FIG. 6B differs from the light emitting device 100B shown in FIG. 4A in that the recess 31c provided on the outer surface of the lens support 30 is located away from the upper and lower surfaces. The recess 31c shown in FIG. 6B is a depression on the outer surface of the lens support 30. FIG. 6C is an exploded perspective view showing a schematic configuration of a light emitting device 130B according to Modification 3 of the second embodiment. The light emitting device 130B shown in FIG. 6C differs from the light emitting device 120B shown in FIG. 6B in that the recess 31c is provided on the upper surface of the lens support 30, and the recess 31c is located away from the inner and outer surfaces. The recess 31c shown in FIG. 6C is a depression on the upper surface of the lens support 30. The recess 31c shown in FIGS. 6B and 6C has a first surface 30cs1 to a third surface 30cs3, similar to the recess 30c shown in FIG. 4B.
[0070] The manufacturing method of the light emitting device 120B according to the second modification of the second embodiment is the same as the manufacturing method of the light emitting device 100B according to the second embodiment. The manufacturing method of the light emitting device 130B according to the third modification of the second embodiment is the same as the manufacturing method of the light emitting device 100B according to the second embodiment, except that the heating laser is incident on the recess 31c from above, not from the side. In the light emitting devices 120B and 130B as well, the end face 30s of the lens support portion 30 and the lens 40 can be bonded via the bonding material 32.
[0071] (Embodiment 3) According to the third embodiment, even if the recess provided in the lens support 30 has a curved surface, the end surface 30s of the lens support 30 can be irradiated with the heating laser light. An example of a light emitting device according to the third embodiment of the present disclosure will be described below with reference to Figs. 7A to 7C, focusing on the differences between the third embodiment and the first and second embodiments. Fig. 7A is an exploded perspective view that shows a schematic configuration of a light emitting device 100C according to the exemplary third embodiment of the present disclosure. Fig. 7B is a top view that shows a schematic configuration of the light emitting device 100C of Fig. 7A. Fig. 7C is a cross-sectional view of the configuration of Fig. 7B taken along line VIIC-VIIC parallel to the YZ plane.
[0072] The light emitting device 100C shown in FIG. 7A is different from the light emitting device 100B shown in FIG. 4A in that the lens support 30 has a recess 30cc having a different shape from the recess 30c. The lens support 30 has a columnar shape with a part of the outer surface cut away. The part has a semi-cylindrical shape. The recess 30cc has a curved surface, and the curved surface has a semi-circular arc shape in a top view as shown in FIG. 7B. The curved surface includes a fourth surface 30cs4 having a 1 / 4 arc shape close to the end surface 30s in a top view, and a fifth surface 30cs5 having a 1 / 4 arc shape away from the end surface 30s in a top view. The fifth surface 30cs5 is located farther from the end surface 30s than the fourth surface 30cs4. The fourth surface 30cs4 is located on the opposite side of the end surface 30s and is located between the end surface 30s and the fifth surface 30cs5, and the fifth surface 30cs5 faces the fourth surface 30cs4. The depth of the recess 30cc in the X direction may be, for example, 0.5 to 0.8 times the dimension of the end surface 30s in the X direction. The curved surface of the recess 30cc does not need to have a semicircular arc shape when viewed from above. The curved surface may have, for example, a part of a semicircular arc shape when viewed from above, or a semielliptical arc shape or a part of a semielliptical arc shape.
[0073] In the third embodiment, as compared with the first embodiment, the distance between the emission surface 20e of the laser diode 20 and the surface of the lens 40 facing the emission surface 20e may be made shorter as shown in Fig. 7C. The effect obtained by making the distance shorter is as described in the second embodiment.
[0074] Hereinafter, a method for manufacturing the light emitting device 100C according to the third embodiment will be described with reference to FIG. 8A and FIG. 8B. FIG. 8A is a diagram for explaining an example of a process in the method for manufacturing the light emitting device 100B according to the third embodiment. The method for manufacturing the light emitting device 100C according to the third embodiment is the same as the method for manufacturing the light emitting device 100B according to the second embodiment, except that the fourth surface 30cs4 of the recess 30cc into which the laser light for heating is incident is a curved surface rather than a flat surface. When the fourth surface 30cs4 is a curved surface, it is easier to manufacture the lens support part 30 than when the fourth surface 30cs4 is a flat surface. Even when the fourth surface 30cs4 has a curved surface, the incident laser light can be refracted toward the end surface 30s. The end surface 30s of the lens support part 30 is irradiated by the laser light refracted by the fourth surface 30cs4. As a result, the joining material 32 is heated, and the end surface 30s of the lens support part 30 and the lens 40 can be joined together. The function of the first metal film 30m as a light absorbing member and the loading of the lens 40 are as described with reference to FIG. 3F.
[0075] FIG. 8B is a diagram for explaining another example of a process in the manufacturing method of the light emitting device 100C according to the third embodiment. A reflecting member 30r is provided on the fifth surface 30cs5 of the recess 30cc shown in FIG. 8B. As shown in FIG. 8B, a laser beam for heating is incident from the side toward the fifth surface 30cs5, more specifically, toward the reflecting member 30r provided thereon. The reflecting member 30r reflects the incident laser beam toward the fourth surface 30cs4, and the fourth surface 30cs4 refracts the incident laser beam toward the end surface 30s. The end surface 30s of the lens support portion 30 is irradiated with the laser beam reflected by the reflecting member 30r and refracted by the fourth surface 30cs4. As a result, the end surface 30s of the lens support portion 30 and the lens 40 can be bonded by heating the bonding material 32. The first metal film 30m functions as a light absorbing member and the lens 40 is loaded as described with reference to FIG. 3F.
[0076] Next, a modified example of the light emitting device 100C according to the third embodiment will be described with reference to Figs. 9A and 9B. Fig. 9A is an exploded perspective view showing a configuration of a light emitting device 110C according to a modified example of the third embodiment. Fig. 9B is a top view showing the light emitting device of Fig. 9A. The light emitting device 110C shown in Fig. 9A differs from the light emitting device 100C shown in Fig. 7A in that the lens support part 30 has a recess 31cc having a different shape from the recess 30cc. The lens support part 30 has a columnar shape with a part of the outer surface cut out. The part is a triangular prism. As shown in Fig. 9B, the recess 31cc has a sixth surface 30cs6 located on the opposite side of the end surface 30s and a seventh surface 30cs7 that forms an acute angle with the sixth surface 30cs6. The seventh surface 30cs7 is located farther from the end surface 30s than the sixth surface 30cs6. The sixth surface 30cs6 and the end surface 30s are approximately parallel to each other. The angle between the sixth surface 30cs6 and the end face 30s may be, for example, 0° or more and 10° or less. The angle between the sixth surface 30cs6 and the seventh surface 30cs7 may be, for example, 30° or more and 60° or less. The normal direction of the seventh surface 30cs7 is parallel to the top face 10s. The sixth surface 30cs6 is located between the end face 30s and the seventh surface 30cs7. The dimension of the side of the sixth surface 30cs6 parallel to the top face 10s may be, for example, 0.5 times or more and 0.8 times or less than the dimension of the end face 30s in the X direction.
[0077] The manufacturing method of the light emitting device 110C according to the modification of the third embodiment is the same as that of the light emitting device 100C according to the third embodiment. That is, as in the example shown in FIG. 8A, the laser light for heating may be incident on the sixth surface 30cs6 of the recess 31cc from the side. Alternatively, as in the example shown in FIG. 8B, a reflecting member 30r may be provided on the seventh surface 30cs7 of the recess 31cc, and the laser light for heating may be incident on the reflecting member 30r from the side. In the light emitting device 110C according to the modification of the third embodiment, the end surface 30s of the lens support portion 30 and the lens 40 can be bonded via the bonding material 32.
[0078] 7A or the recess 31cc shown in FIG. 9A may be provided on the upper surface of the lens support portion 30 instead of on the outer surface thereof.
[0079] (Embodiment 4) According to the fourth embodiment, the end surface 30s of the lens support 30 and the lens 40 can be bonded by heating the bonding material 32 without irradiating the end surface 30s of the lens support 30 with a heating laser beam. An example of a light emitting device according to the fourth embodiment of the present disclosure will be described below with reference to Figs. 10A to 10C, focusing on the differences between the fourth embodiment and the first to third embodiments. Fig. 10A is an exploded perspective view showing a schematic configuration of a light emitting device 100D according to an exemplary fourth embodiment of the present disclosure. Fig. 10B is a top view showing the light emitting device 100D of Fig. 10A. Fig. 10C is a cross-sectional view of the configuration of Fig. 10B taken along line XC-XC parallel to the YZ plane.
[0080] The light emitting device 100D shown in FIG. 10A is different from the light emitting device 100B shown in FIG. 4A in that the lens support part 30 has a light absorbing member 30a in the recess 30c. As shown in FIG. 10B, the first surface 30cs1 to the third surface 30cs3 of the recess 30c are provided with the light absorbing member 30a. The light absorbing member 30a may be formed of at least one metal selected from the group consisting of Ti, Ni, and Cr. The light absorbing member 30a may be provided not only on the first surface 30cs1 to the third surface 30cs3 of the recess 30c, but also so as to fill the recess 30c. The light absorbing member 30a provided in the recess 30c functions when the end surface 30s of the lens support part 30 and the lens 40 are joined during the manufacture of the light emitting device 100C. The lens support part 30 in the fourth embodiment does not necessarily need to be formed of a light-transmitting material for reasons to be described later.
[0081] In the fourth embodiment, as compared with the first embodiment, the distance between the emission surface 20e of the laser diode 20 and the surface of the lens 40 facing the emission surface 20e may be made shorter as shown in Fig. 10C. The effect obtained by making the distance shorter is as described in the second embodiment.
[0082] Hereinafter, a method for manufacturing the light emitting device 100D according to the fourth embodiment will be described with reference to FIG. 11. FIG. 11 is a diagram for explaining an example of a process in the method for manufacturing the light emitting device 100D according to the fourth embodiment. The process of preparing the substrate 10, the laser diode 20, the lens support 30, and the lens 40, and the process of connecting the end face 30s of the lens support 30 and the lens 40 via the bonding material 32 have been described with reference to FIGS. 3A to 3E. In the next process after connecting the two, as shown in FIG. 11, a laser beam for heating is incident from the side toward a portion of the light absorbing member 30a provided on the first surface 30cs1 of the recess 30c. The portion absorbs the laser beam and converts it into heat. The heat generated in this way is transferred to the end face 30s through a portion of the lens support 30 between the first surface 30cs1 and the end face 30s. As a result, the bonding material 32 is heated, and the end face 30s of the lens support 30 and the lens 40 can be bonded to each other. As described above, the light absorbing member 30a is provided in the front portion of the lens support part 30, laser light is incident on the light absorbing member 30a, and heat generated in the light absorbing member 30a is transferred to the end face 30s, thereby heating the bonding material 32. The end face 30s of the lens support part 30 and the lens 40 can be bonded via the bonding material 32 heated in this way. The load of the lens 40 is as described with reference to FIG. 3F.
[0083] When the lens support part 30 is made of a light-transmitting material, the portions of the light absorbing member 30a provided on the second surface 30cs2 and the third surface 30cs3 of the recess 30c can prevent the heating laser light from passing through the lens support part 30 and reaching the laser diode 20. As a result, it is possible to prevent the laser diode 20 from being damaged or its operating characteristics from being deteriorated due to heating.
[0084] In the fourth embodiment, the lens support section 30 only needs to have a function of transmitting heat generated in the light absorbing member 30a to the end surface 30s. Therefore, the lens support section 30 does not necessarily need to be made of a light-transmitting material that transmits the heating laser light. The material of the lens support section 30 preferably has a thermal conductivity of 1 W / m·K or more and 500 W / m·K or less, in order to efficiently transmit heat. For example, the lens support section 30 may be made of the same material as the substrate 10.
[0085] The recess in which the light absorbing member 30a is provided may not be the recess 30c shown in Fig. 10A, but may be any of the other recesses described above. In the example shown in Fig. 8B, the light absorbing member may be provided on the fourth surface 30cs4. Furthermore, the recess in which the light absorbing member 30a is provided may be provided on the upper surface of the lens support part 30, rather than on the outer surface thereof.
[0086] (Embodiment 5) According to the fifth embodiment, even if the lens support part 30 has a configuration in which it straddles the laser diode 20, it is possible to heat the bonding material 32 to bond the end face 30s of the lens support part 30 to the lens 40. An example of a light emitting device according to the fifth embodiment of the present disclosure will be described below with reference to Fig. 12, focusing on the differences between the fifth embodiment and the first to fourth embodiments. Fig. 12 is an exploded perspective view that typically illustrates the configuration of a light emitting device 100E according to the fifth exemplary embodiment of the present disclosure.
[0087] The light emitting device 100E shown in FIG. 12 differs from the light emitting device 100B shown in FIG. 4A in the structure of the lens support 30. The lens support 30 shown in FIG. 12 does not have a rear portion, but has both side portions 30о located on both sides of the laser diode 20, and a connecting portion 30LK located above the laser diode 20 and connecting the both side portions 30о. The lens support 30 may be provided on the upper surface 10s of the substrate 10 so as to straddle the laser diode 20, and may be provided with a connecting portion 30LK so as to straddle the laser diode 20 in addition to the lens support 30 of the first to fourth embodiments. The lens support 30 is U-shaped and does not prevent the laser light emitted from the laser diode 20 from entering the lens 40. The end surface 30s of the lens support 30 includes the end surfaces of the both side portions 30о and the end surface of the connecting portion 30LK. A first metal film 30m is provided on a part of the end surface of the both side portions 30о. The lens support 30 has recesses 33c on the outer surfaces of both side portions 30о. The shape of the recesses 33c may be the same as in the second or third embodiment.
[0088] The manufacturing method of the light emitting device 100E according to the embodiment 5 is the same as the manufacturing method of the light emitting device 100B according to the embodiment 2. In the light emitting device 100E, the end face 30s of the lens support part 30 and the lens 40 can be bonded via the bonding material 32.
[0089] The lens support part 30 may have both side parts including wide parts 30w as shown in FIG. 2A instead of both side parts 30о shown in FIG. 12. The material, manufacturing method, and effects of the light emitting device including such a lens support part 30 are as described in the first embodiment. Alternatively, the lens support part 30 may further have a light absorbing member 30a as shown in FIG. 10A in the recess 33c of the both side parts 30о shown in FIG. 12. The material, manufacturing method, and effects of the light emitting device including such a lens support part 30 are as described in the fourth embodiment. [Industrial Applicability]
[0090] The method for manufacturing a semiconductor device according to the present disclosure can be applied to light emitting devices used in, for example, manufacturing, projectors, and lighting fixtures. [Explanation of symbols]
[0091] 10 Substrate Front end of 10fs substrate 10s top 20 Laser Diode 20e exit surface 22 Submount 22fs Submount front end 30 Lens support 30a Light absorbing material 30c, 30cc recess 30cs1 1st surface 30cs2 2nd surface 30cs3 3rd surface 30cs4 4th surface 30cs5 5th surface 30cs6 6th surface 30cs7 7th surface 30d Light diffusion section 30L straight section 30LK connection part 30m 1st metal film 30о Both sides 30r Reflective material 30s end face 30w wide part 31c, 31cc recess 32 Bonding material 33c Recess 40 Lenses 40a Convex lens part 40b Flat plate part 40m 2nd metal film 40s Surface facing the end face of the lens support part 50 packages 50b base 50bt Inner bottom surface of base 50m material 50L lid body 50w transparent window 60 Lead terminal 60w Wire 100 Light emitting device 100A Light Emitting Device 100B, 110B, 120B, 130B Light emitting device 100C, 110C Light-emitting device 100D Light Emitting Device 100E Light Emitting Device
Claims
1. preparing a substrate supporting a semiconductor light emitting element and a lens support portion, and a lens; a step of connecting the lens and the lens support portion via a bonding material; a step of bonding the lens and the lens support part by applying a laser beam to the lens support part to heat a bonding material; Including, The lens support portion is formed from a light-transmitting material, the lens support portion has an end surface to which the lens is bonded and a wide portion that becomes wider toward the semiconductor light emitting element as it approaches the end surface, the wide portion has an inner surface located on the semiconductor light emitting element side, A method for manufacturing a light emitting device, comprising: directing the laser light through the inside of the wide portion to be incident on the inner surface, and reflecting the laser light toward the end surface, thereby irradiating the end surface with the laser light and heating the bonding material.
2. The wide portion has a reflective member on the inner surface, The method for manufacturing a light emitting device according to claim 1 , wherein the end face is irradiated with the laser light by reflecting the laser light toward the end face by the reflecting member.
3. the wide portion has an outer surface located on the opposite side to the semiconductor light emitting element, and a light diffusing portion provided on the outer surface or the inner surface, The method for manufacturing a light emitting device according to claim 1 , wherein the end surface is irradiated with the laser light by diffusing the laser light in the light diffusing portion.
4. A step of preparing a substrate supporting a semiconductor light emitting element and a lens support portion, and a lens; a step of connecting the lens and the lens support portion via a bonding material; a step of bonding the lens and the lens support part by applying a laser beam to the lens support part to heat a bonding material; Including, the lens support portion is formed from a light-transmitting material and has an end surface and a recess; a first recess for incident laser light onto the end face, the first recess being a first region for refracting the laser light toward the end face, or a second recess for incident laser light onto the end face, the first recess being a first region for refracting the laser light toward the end face, and a third recess for reflecting the laser light toward the end face.
5. 5. The method for manufacturing a light emitting device according to claim 4, wherein the lens support portion includes a light absorbing member in the recess or between the end face and the lens, the laser light is incident on the light absorbing member, and heat generated in the light absorbing member is transferred to the end face.
6. A reflecting member is provided in a part of the recess, 6. The method for manufacturing a light emitting device according to claim 4, further comprising the steps of: making the laser light incident on the reflecting member and reflecting the laser light toward the end face by the reflecting member, thereby irradiating the end face with the laser light.
7. A step of preparing a substrate supporting a semiconductor light emitting element and a lens support portion, and a lens; a step of connecting the lens and the lens support portion via a bonding material; a step of bonding the lens and the lens support part by applying a laser beam to the lens support part to heat a bonding material; Including, the lens support portion has an end surface and a recess; A method for manufacturing a light emitting device, comprising providing a light absorbing member in the recess or between the end face and the lens, causing the laser light to be incident on the light absorbing member, and transferring heat generated in the light absorbing member to the end face.
8. The method for manufacturing a light emitting device according to claim 1 , wherein the lens support portion and the lens are made of glass.
9. The method for manufacturing a light emitting device according to claim 1 , wherein the semiconductor light emitting element is provided on the upper surface of the substrate via a submount.
10. a substrate having a top surface; a semiconductor light emitting element provided directly or indirectly on the upper surface and having an emission surface; one or more lens support parts provided on the upper surface, located in the vicinity of the light exit surface, having an end surface, and made of a light-transmitting material, the vicinity meaning a spherical range within a radius of 5 mm from the center of the light exit surface; and a lens bonded to the end surface via a bonding material; Equipped with the lens support portion has a wide portion that becomes wider toward the semiconductor light emitting element as it approaches the end surface, A light emitting device, wherein the wide portion has an inner surface located on the side of the semiconductor light emitting element, a reflective member provided on the inner surface, an outer surface located on the opposite side to the semiconductor light emitting element, and a light diffusing portion provided on the outer surface or the inner surface.
11. The light emitting device according to claim 10 , wherein the light diffusing portion is a portion of the outer surface or the inner surface that is roughened.
12. a substrate having a top surface; a semiconductor light emitting element provided directly or indirectly on the upper surface and having an emission surface; one or more lens support parts provided on the upper surface, located near the exit surface, and having an end surface, the vicinity meaning a spherical range within a radius of 5 mm from the center of the exit surface; a lens bonded to the end surface via a bonding material; Equipped with The lens support portion has a recess, A light emitting device comprising a light absorbing member in the recess or between the end face and the lens.
13. The light emitting device according to claim 12 , wherein the lens support is made of a light-transmitting material.
Citation Information
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