Light emitting device, light emitting module, method for producing light emitting device, and method for producing light emitting module

Abstract

Disclosed is a light emitting device which is provided with a base material (70), a semiconductor laser element (10) that is bonded to the base material (70), and a first bonding layer (30) that bonds the base material (70) and the semiconductor laser element (10) to each other, wherein: the first bonding layer (30) comprises an element bonding layer (43) that is formed of a single metal element, a metal film (50) that is disposed between the element bonding layer (43) and the base material (70) and is formed of a sintered body of a single metal element, and a base material bonding layer (62) that is disposed between the metal film (50) and the base material (70) and is formed of a single metal element; the metal film (50) is formed of Au, Ag, Cu or Al; and the total thickness of the element bonding layer (43), the metal film (50) and the base material bonding layer (62) is 80% or more of the thickness of the first bonding layer (30).

Description

Light-emitting device, light-emitting module, method for manufacturing light-emitting device, and method for manufacturing light-emitting module

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

[0002] Conventionally, a light-emitting device called a CoS (Chip on Submount) has been known, in which a semiconductor laser element is mounted on a substrate such as a submount (see, for example, Patent Document 1). The light-emitting element is bonded to the substrate in a predetermined position and orientation. Solder, for example, is used to bond the semiconductor laser element to the substrate. Such a light-emitting device is used by being mounted on a mounting base, such as a heat sink.

[0003] International Publication No. 2021 / 230294

[0004] A light-emitting device such as that described in Patent Document 1 is bonded to a mounting base using, for example, solder. At this time, the solder arranged between the base of the light-emitting device and the mounting base must be heated to melt the solder. As a result, the light-emitting device is also heated, which can melt the solder arranged between the base of the light-emitting device and the semiconductor laser element. This can cause the relative position and orientation of the semiconductor laser element with respect to the base to change. Consequently, the optical axis of the semiconductor laser element can deviate from its predetermined position.

[0005] Furthermore, if the solder connecting the semiconductor laser element and the base remelts, gaps or voids will form between the semiconductor laser element and the base, which can result in a decrease in the heat dissipation performance of the light-emitting device compared to the initial state, making it impossible to achieve the designed laser characteristics.

[0006] Therefore, an object of the present disclosure is to provide a structure and a manufacturing method for a light-emitting device including a semiconductor laser element and a substrate, which can suppress changes in the basic characteristics even after the device has been mounted on a heat sink or the like.

[0007] In order to achieve the above object, a light-emitting device according to one aspect of the present disclosure includes a base, a semiconductor laser element bonded to the base, and a first bonding layer bonding the base and the semiconductor laser element, the first bonding layer including an element bonding layer made of a single metal element, a metal film of a sintered body made of a single metal element disposed between the element bonding layer and the base, and a base bonding layer made of a single metal element disposed between the metal film and the base, the metal film being made of Au, Ag, Cu, or Al, and the total thickness of the element bonding layer, the metal film, and the base bonding layer is 80% or more of the thickness of the first bonding layer.

[0008] To achieve the above object, another aspect of the present disclosure provides a light-emitting module comprising the light-emitting device, a heat sink to which the base of the light-emitting device is joined, and a second bonding layer that bonds the base and the heat sink, wherein the melting point of the second bonding layer is lower than the melting point of the first bonding layer.

[0009] In order to achieve the above-mentioned object, in a method for manufacturing a light-emitting device according to another aspect of the present disclosure, the light-emitting device includes a base, a semiconductor laser element bonded to the base, and a first bonding layer bonding the base and the semiconductor laser element, the first bonding layer including an element bonding layer made of a single metal element, a metal film of a sintered body made of a single metal element disposed between the element bonding layer and the base, and a base bonding layer made of a single metal element disposed between the metal film and the base, and the method for manufacturing the light-emitting device includes an element bonding layer forming step of forming the element bonding layer on the semiconductor laser element, a base bonding layer forming step of forming the base bonding layer on the base, a coating step of applying a paste in which metal fine particles are dispersed in a solvent onto the base bonding layer, a disposing step of disposing the element bonding layer on the paste, and a sintering step of heating the paste to turn the paste into the metal film.

[0010] In order to achieve the above object, a method for manufacturing a light-emitting module according to another aspect of the present disclosure includes the method for manufacturing the light-emitting device described above, wherein the light-emitting module comprises the light-emitting device and a heat sink to which the base of the light-emitting device is joined, and the method for manufacturing the light-emitting module further includes a second bonding layer arrangement step of arranging a second bonding layer on the heat sink, a base arrangement step of arranging the base on the second bonding layer, and a bonding step of joining the base to the heat sink by heating the second bonding layer.

[0011] According to the present disclosure, in a light-emitting device including a semiconductor laser element and a base, changes in the relative position and orientation of the semiconductor laser element with respect to the base can be suppressed when the semiconductor laser element is mounted on a heat sink or the like.

[0012] 1 is a schematic cross-sectional view showing an overall configuration of a light-emitting device according to embodiment 1. FIG. 2 is a schematic cross-sectional view showing an overall configuration of a light-emitting module according to embodiment 1. FIG. 3 is a schematic cross-sectional view showing a first step of a method for manufacturing a light-emitting device according to embodiment 1. FIG. 4 is a schematic cross-sectional view showing a second step of the method for manufacturing a light-emitting device according to embodiment 1. FIG. 5 is a schematic cross-sectional view showing a third step of the method for manufacturing a light-emitting device according to embodiment 1. FIG. 6 is a schematic cross-sectional view showing a fourth step of the method for manufacturing a light-emitting device according to embodiment 1. FIG. 7 is a schematic cross-sectional view showing a fifth step of the method for manufacturing a light-emitting device according to embodiment 1. FIG. 8 is a schematic cross-sectional view showing a sixth step of the method for manufacturing a light-emitting device according to embodiment 1. FIG. 9 is a schematic cross-sectional view showing a seventh step of the method for manufacturing a light-emitting device according to embodiment 1. FIG. 10 is a schematic perspective view showing a ninth step of the method for manufacturing a light-emitting device according to embodiment 1. FIG. 11 is a schematic cross-sectional view showing a tenth step of the method for manufacturing a light-emitting device according to embodiment 1. FIG. 12 is a schematic cross-sectional view showing a first step of the method for manufacturing a light-emitting module according to embodiment 1. FIG. 13 is a schematic cross-sectional view showing a second step of the method for manufacturing a light-emitting module according to embodiment 1. 1 is a schematic cross-sectional view showing a third step of the method for manufacturing a light-emitting module according to embodiment 1. FIG. 2 is a schematic perspective view showing the overall configuration of a light-emitting module according to embodiment 2. FIG. 3 is a schematic perspective view showing a first step of the method for manufacturing a light-emitting module according to embodiment 2. FIG. 4 is a schematic perspective view showing a second step of the method for manufacturing a light-emitting module according to embodiment 2. FIG. 5 is a schematic perspective view showing a third step of the method for manufacturing a light-emitting module according to embodiment 2. FIG. 6 is a schematic perspective view showing a fourth step of the method for manufacturing a light-emitting module according to embodiment 2. FIG. 7 is a schematic perspective view showing a fifth step of the method for manufacturing a light-emitting module according to embodiment 2. FIG. 8 is a schematic perspective view showing the overall configuration of a light-emitting module according to embodiment 3. FIG. 9 is a schematic perspective view showing a first step of the method for manufacturing a light-emitting module according to embodiment 3. FIG. 10 is a schematic perspective view showing a second step of the method for manufacturing a light-emitting module according to embodiment 3.Fig. 10 is a schematic cross-sectional view showing the overall configuration of a light-emitting module according to a modified example of embodiment 3. Fig. 11 is a schematic cross-sectional view showing the overall configuration of a light-emitting module according to embodiment 4. Fig. 12 is a schematic cross-sectional view showing the overall configuration of a light-emitting module according to embodiment 5. Fig. 13 is a schematic cross-sectional view showing the overall configuration of a light-emitting module according to a modified example of embodiment 5. Fig. 14 is a schematic cross-sectional view showing the overall configuration of a light-emitting module according to embodiment 6.

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, arrangement and connection of the components, steps, order of steps, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0014] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales of the figures do not necessarily match. Furthermore, in each figure, substantially the same components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0015] Furthermore, in this specification, terms indicating the relationship between elements, such as "equal," terms indicating the shape of elements, such as "flat," "parallel," "vertical," "plate-shaped," and "curved," as well as numerical ranges, are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0016] In this specification, the terms "above" and "below" do not refer to vertically above and below in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in a stacked configuration. The terms "above" and "below" are used not only when two components are arranged with a gap between them and another component is present between them, but also when two components are arranged closely together and are in contact with each other.

[0017] First Embodiment A light emitting device and a light emitting module according to a first embodiment, as well as a method for manufacturing the same, will be described.

[0018] [1-1. Overall Configuration of Light-Emitting Device] The overall configuration of a light-emitting device according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic cross-sectional view showing the overall configuration of a light-emitting device 1 according to this embodiment. FIG. 1 shows a cross section perpendicular to the propagation direction of light emitted by the light-emitting device 1. As shown in FIG. 1, the light-emitting device 1 includes a semiconductor laser element 10, a base 70, and a first bonding layer 30. In this embodiment, the light-emitting device 1 further includes a first electrode 20.

[0019] The semiconductor laser element 10 is an edge-emitting semiconductor light-emitting element that emits laser light from the side surface (edge) of the element. In this embodiment, the semiconductor laser element 10 includes a semiconductor laminate 10S. The configuration and dimensions of the semiconductor laser element 10 are not particularly limited. The semiconductor laser element 10 may emit, for example, infrared light, visible light, or ultraviolet light. In this embodiment, the semiconductor laser element 10 emits blue laser light. The length (in the resonance direction) of the semiconductor laser element 10 may be approximately 1.2 mm, the width may be approximately 150 μm, and the thickness may be approximately 80 μm. The semiconductor laser element 10 according to this embodiment includes a substrate 11, a semiconductor laminate 10S, and an insulating film 15. The semiconductor laser element 10 is junction-down mounted on a base 70. That is, the semiconductor laminate 10S of the semiconductor laser element 10 is bonded to the base 70 via a first bonding layer 30 or the like. Since a part of the semiconductor laminate 10S generates heat during operation of the semiconductor laser element 10, bonding the surface on which this semiconductor laminate 10S is formed to the base 70 can achieve higher heat dissipation than bonding the substrate 11 to the base 70. In other words, the light-emitting device 1 in which the semiconductor laser element 10 is junction-down mounted as in this embodiment can enhance the effect of improving heat dissipation.

[0020] The substrate 11 is a plate-like member that serves as a base for the semiconductor laser device 10 .

[0021] The semiconductor stack 10S is a stack including multiple semiconductor layers stacked on a substrate 11, and includes a pn junction. In this embodiment, the semiconductor stack 10S has a first semiconductor layer 12 including a semiconductor of a first conductivity type, an active layer 13 that generates light, and a second semiconductor layer 14 including a semiconductor of a second conductivity type different from the first conductivity type. For example, the first conductivity type and the second conductivity type are n-type and p-type, respectively.

[0022] The semiconductor laminate 10S has a facing surface 10Sa facing the substrate 11, a back surface 10Sb on the back side of the facing surface 10Sa, and a side surface 10Sc connected to the facing surface 10Sa and extending along the resonance direction of the semiconductor laser element 10.

[0023] In this embodiment, the semiconductor laminate 10S has a ridge stripe 14R, two grooves 14T, two raised portions 14W, and two laminate recesses 10T.

[0024] The two grooves 14T are recesses formed on the back surface 10Sb of the semiconductor laminate 10S and extending parallel to the resonance direction of laser light in the semiconductor laser device 10. The two grooves 14T are formed in the second semiconductor layer .

[0025] The ridge stripe 14R is disposed on the back surface 10Sb behind the facing surface 10Sa of the semiconductor laminate 10S that faces the substrate 11, and is a convex portion extending parallel to the resonance direction of laser light in the semiconductor laser element 10. The ridge stripe 14R protrudes in a direction away from the substrate 11 (upward in FIG. 1). The ridge stripe 14R is a structure for confining the current supplied to the active layer 13 to the central portion in the lateral direction in FIG. 1, and also functions as an optical waveguide. The longitudinal direction of the ridge stripe 14R is the resonance direction of the laser light.

[0026] In this embodiment, the width of the ridge stripe 14R (the horizontal dimension in FIG. 1 ) is 45 μm. The width of the ridge stripe 14R is designed based on the expected operating optical output. Generally, to achieve high operating optical output in the semiconductor laser device 10, the width of the ridge stripe 14R needs to be large. This is to reduce the optical density at the laser light output facet and avoid the occurrence of a destructive phenomenon known as COD (catastrophic optical damage). However, increasing the width of the ridge stripe 14R increases the current required for laser oscillation, i.e., the oscillation threshold current, and increases the temperature of the semiconductor laser device 10. Therefore, the designer determines an appropriate width of the ridge stripe 14R, taking into account the expected optical output, the laser characteristics of the semiconductor laser device, the thermal resistance of the entire light-emitting device 1, and the like. At the current technological level, the width of the ridge stripe 14R is often designed to be approximately 1 μm or more and 100 μm or less.

[0027] Each of the two raised portions 14W is a region between the groove 14T and the side surface 10Sc of the semiconductor laminate 10S, and is a convex portion that protrudes from the bottom of the groove 14T in a direction away from the substrate 11. In other words, the groove 14T is disposed between each of the two raised portions 14W and the ridge stripe 14R.

[0028] The two stack recesses 10T are located between the back surface 10Sb and the side surface 10Sc of the semiconductor stack 10S and are recessed relative to the back surface 10Sb and the side surface 10Sc. Here, the side surface 10Sc is the end face of the semiconductor stack 10S in the lateral direction (perpendicular to the stacking direction of the semiconductor stack 10S and the resonance direction of the laser light) shown in FIG. 1 . In other words, the side surface 10Sc is a surface of the semiconductor stack 10S that is connected to the opposing surface 10Sa and extends along the resonance direction of the laser light of the semiconductor laser element 10. The depth of the stack recess 10T from the back surface 10Sb toward the substrate 11 is deeper than the depth from the back surface 10Sb to the pn junction and reaches halfway through the first semiconductor layer 12. The stack recess 10T may be part of an isolation groove formed when the semiconductor laser element 10 is singulated. The stack recess 10T is also covered with an insulating film 15. That is, the insulating film 15 covers the first semiconductor layer 12 in the stacked body recess 10T.

[0029] The insulating film 15 covers a portion of the semiconductor laminate 10S. The insulating film 15 is disposed on the back surface 10Sb of the semiconductor laminate 10S. In this embodiment, the insulating film 15 covers all but the top surface of the ridge stripe 14R. That is, the insulating film 15 continuously covers from one laminate recess 10T to one side surface of the ridge stripe 14R, and also continuously covers from the other laminate recess 10T to the other side surface of the ridge stripe 14R. The insulating film 15 is disposed between the semiconductor laminate 10S and the adhesion layer 42. The material of the insulating film 15 is not particularly limited as long as it is electrically insulating. In this embodiment, the insulating film 15 is a silicon oxide film having a thickness of 300 nm.

[0030] The first electrode 20 is a conductive member disposed on the substrate 11. The first electrode 20 is disposed on the principal surface of the substrate 11, the principal surface being opposite to the principal surface on which the semiconductor stacked body 10S is stacked. In the present embodiment, the first electrode 20 has an ohmic electrode layer 21 and a pad electrode layer 22.

[0031] The ohmic electrode layer 21 is an electrode in contact with the substrate 11. An ohmic contact is formed electrically at the interface between the ohmic electrode layer 21 and the substrate 11. The ohmic electrode layer 21 may have a function of increasing the adhesion between the substrate 11 and the pad electrode layer 22. The ohmic electrode layer 21 may be a single layer film or a multilayer film made of at least one of Ti, Al, Cr, Ag, Ni, Pd, and Pt, for example.

[0032] The pad electrode layer 22 is a conductive layer for supplying power to the semiconductor laser device 10. For example, a wire (described later) is connected to the pad electrode layer 22. The pad electrode layer 22 may be, for example, a single-layer film made of Au. In this embodiment, the pad electrode layer 22 is an Au film having a thickness of 0.3 μm or less.

[0033] The first bonding layer 30 is a conductive layer that bonds the base 70 and the semiconductor laser element 10. The first bonding layer 30 has a second electrode 40, a metal film 50, and a base electrode 60, which are arranged in this order from the semiconductor laser element 10 toward the base 70.

[0034] The second electrode 40 is a conductive member disposed on the semiconductor stack 10S. The second electrode 40 is disposed on the back surface 10Sb of the semiconductor stack 10S. The second electrode 40 has an element bonding layer 43. In the present embodiment, the second electrode 40 further has an ohmic electrode layer 41 and an adhesion layer 42.

[0035] The ohmic electrode layer 41 is an electrode in contact with the semiconductor laser device 10. The ohmic electrode layer 41 makes ohmic contact with the second semiconductor layer 14 of the semiconductor stack 10S. In this embodiment, the ohmic electrode layer 41 is disposed on the upper surface of the ridge stripe 14R (i.e., the surface of the ridge stripe 14R that is located farthest from the substrate 11). The ohmic electrode layer 41 may be, for example, a single-layer film or a multilayer film made of at least one of Pd, Ni, Pt, Au, Ag, W, Ti, and Al. Metal oxides such as ITO and ZnO may also form ohmic contact. However, these materials have low thermal conductivity and are disadvantageous in terms of heat dissipation. In this embodiment, the ohmic electrode layer 41 is a Pd film having a thickness of 0.1 μm or less.

[0036] The adhesion layer 42 is a conductive layer disposed between the ohmic electrode layer 41 and the device bonding layer 43. The adhesion layer 42 may have the function of increasing the adhesion between the semiconductor laser device 10 and the device bonding layer 43. The adhesion layer 42 may cover the ohmic electrode layer 41. In this embodiment, the adhesion layer 42 may be, for example, a single layer film made of Ti, Cr, or Ni. These materials, which have the function of increasing adhesion, have low thermal conductivity and are disadvantageous in terms of heat dissipation. Therefore, the thickness thereof may be as thin as possible. In this embodiment, the adhesion layer 42 is a Ti film having a thickness of 0.1 μm or less.

[0037] The element bonding layer 43 is a metal layer disposed between the semiconductor laser element 10 and the metal film 50. The element bonding layer 43 is a conductive layer bonded to a conductor for supplying power to the semiconductor laser element 10. The element bonding layer 43 also plays a role in efficiently conducting heat generated in the semiconductor laser element 10 to the substrate 70. Therefore, the element bonding layer 43 is composed of a single metal element. In a layer composed of a single metal element, alloy scattering of electrons and phonons does not occur, so the electrical resistance and thermal resistance of the element bonding layer 43 can be reduced. The element bonding layer 43 may be selected from Au, Ag, Cu, or Al. All of these metals have a thermal conductivity of 200 W·m －１ ・K －１ These metals have values ​​above 100. Among metallic materials, these metals are characterized by their particularly high thermal conductivity.

[0038] Furthermore, a part or all of the element bonding layer 43 contacts the metal film 50, which is a sintered body, to form a continuum. For this reason, a part or all of the element bonding layer 43 may be composed of the same metal element as the metal film 50. This increases the bonding strength between the element bonding layer 43 and the metal film 50. However, since a sintered body of Ag, for example, also forms a continuum with metals other than Ag, the element bonding layer 43 does not necessarily have to be made of the same metal as the metal film 50.

[0039] Furthermore, in this embodiment, the first bonding layer 30 has a single element bonding layer 43, but may have multiple element bonding layers. For example, the first bonding layer 30 may have an element bonding layer made of Cu in addition to the element bonding layer 43 made of Au. The multiple element bonding layers do not need to be adjacent. Depending on the purpose, another layer, such as an adhesive layer, may be inserted between the two element bonding layers. However, layers made of metal elements other than Au, Ag, Cu, and Al have low thermal conductivity and therefore may hinder heat dissipation. Therefore, the layers made of metal elements other than Au, Ag, Cu, and Al may be formed as thin as possible.

[0040] The metal film 50 is disposed between the element bonding layer 43 and the substrate 70 and is a conductive film made of a single metal element. The metal film 50 is in contact with the element bonding layer 43. The metal film 50 may be a sintered body of metal particles formed by, for example, heating a paste in which metal particles are dispersed in a solvent (organic solvent) to remove the solvent and sinter the metal particles. The metal particles are made of, for example, Au, Ag, Cu, or Al. The average particle size of the metal particles measured with a scanning electron microscope is 1 μm or less. Here, the average particle size is a value determined by the intercept method on a cross-sectional image taken with a scanning electron microscope. The metal particles melt when heated at a relatively low temperature of approximately 250°C, and the metal particles bond together (in other words, are sintered). The paste contains metal particles and a solvent, and may also contain a surfactant to improve the dispersibility of the metal particles. The solvent used in the paste is, for example, ester alcohol (2,2,4-trimethyl-3-hydroxypentaisobutyrate: C １２ H ２４ O ３ ), terpineol, pine oil, butyl carbitol acetate, butyl carbitol, carbitol, and other organic solvents. The surfactants are, for example, alkylamines (CH ３ (CH ２ ) ｎ NH ２ ), alkylamine carboxylates, carboxylic acid amides, ester amines, organic titanium compounds, sodium sulfocarboxylates, etc.

[0041] The boiling point of the solvent may be 250° C. or lower, or may be 150° C. or higher and 230° C. or lower. When the boiling point of the solvent is in the range of 150° C. or higher and 230° C. or lower, the solvent can be prevented from being trapped between the sintered metal fine particles when the solvent is removed by heating.

[0042] The metal film 50, which is a sintered body formed in this manner, may be a porous film having voids. When observed in cross section, the porosity of the metal film 50 in terms of area ratio is, for example, less than 30%. The average cross-sectional area of ​​each void is less than 1 μm ２ or less. This makes it possible to suppress a decrease in thermal conductivity in the metal film 50 due to voids. Therefore, the heat dissipation of the semiconductor laser element 10 can be improved compared to when solder made of AuSn is used as the metal film 50. The porosity in terms of area ratio in the cross section of the metal film 50 can be calculated, for example, as follows. In an electron microscope photograph using reflected electrons of the cross section of the metal film 50, the void portions are observed to have low brightness because there are fewer reflected electrons. Therefore, in the electron microscope photograph, areas where the brightness is below a certain value can be determined to be voids. Specifically, a histogram of the brightness of pixels in the measurement area can be calculated, and the proportion of areas below a certain value can be determined to be the void ratio.

[0043] The porosity of the metal film 50 depends on the pressure applied to the metal film 50 during sintering. For example, in FIG. 1 , the highly packed portion 50a of the metal film 50, which is sandwiched between the semiconductor laser element 10 and the base 70, is compressed vertically between the semiconductor laser element 10 and the base 70 during the sintering process due to heating. Therefore, the metal particles in the highly packed portion 50a press against each other and become crushed. As a result, the voids between the metal particles are filled, and the highly packed portion 50a with a low porosity is easily formed.

[0044] On the other hand, the low filling portion 50b of the metal film located outside the high filling portion 50a is not subjected to direct pressure from the semiconductor laser element 10 and the substrate 70. Therefore, the metal particles in the low filling portion 50b form a sintered body without pressing against each other. As a result, the voids that existed between the metal particles are preserved, and the low filling portion 50b is likely to have a higher void ratio than the high filling portion 50a.

[0045] The voids in the metal film 50 function to locally block the heat dissipation path. Therefore, in order to improve heat dissipation, the porosity of the metal film 50 may be low. Considering the heat dissipation path of the heat generated in the semiconductor laser element 10, the high-filling portion 50a of the metal film 50 constitutes the main part of the heat dissipation path. Therefore, the sintering process may be performed by applying pressure from above and below to the high-filling portion 50a so that the porosity is as low as possible. As a result, the porosity of the high-filling portion 50a is lower than that of the low-filling portion 50b. Furthermore, the average cross-sectional area of ​​the individual voids in the low-filling portion 50b is larger than the average cross-sectional area of ​​the individual voids in the high-filling portion 50a.

[0046] The metal film 50 is made of a single metal element. This prevents alloy scattering of electrons and phonons in the metal film 50, thereby reducing the electrical resistance and thermal resistance of the metal film 50. The metal film 50 is made of Au, Ag, Cu, or Al. All of these metals have a thermal conductivity of 200 W·m －１ ・K －１ or higher. In other words, these metals are characterized by having particularly high thermal conductivity among metallic materials. In this embodiment, the metal film 50 is made of Au. The thickness of the metal film 50 is, for example, 3 μm or more. The melting point of the Au metal film 50 formed as a sintered body in this manner is close to the melting point of 1064°C of general bulk Au material. Therefore, when the light-emitting device 1 is bonded to a mounting base such as a heat sink using solder, the metal film 50 does not melt even if heated to approximately 300°C to melt the solder. Therefore, in the light-emitting device 1, changes in the relative position and orientation of the semiconductor laser element 10 with respect to the base 70 can be suppressed when the light-emitting device 1 is mounted on the mounting base.

[0047] The thickness of the metal film 50 may be 10 μm or less, which can reduce the thermal resistance of the metal film 50 and improve the heat dissipation of the light-emitting device 1 .

[0048] The metal film 50, the pad electrode layer 22, and the base bonding layer 62 (described later) may be made of the same metal element, thereby increasing the bonding strength between the metal film 50 and the pad electrode layer 22 and the base bonding layer 62.

[0049] In this embodiment, the metal film 50 has an extension 50e that extends outward from the side surface of the semiconductor laser element 10 (i.e., the side surface 10Sc of the semiconductor laminate 10S) in the horizontal direction in a cross-sectional view perpendicular to the resonance direction (i.e., in the left-right direction in FIG. 1 ). By extending the metal film 50 to the outside of the side surface of the semiconductor laser element 10 in this manner, it becomes possible to cover almost the entire surface of the semiconductor laser element 10 that faces the base 70 with the metal film 50. Therefore, the thermal resistance between the semiconductor laser element 10 and the base 70 can be reduced, and the heat dissipation properties of the semiconductor laser element 10 can be improved.

[0050] The surface of the extension 50e has a convex shape. That is, the surface of the extension 50e protrudes outward. This increases the number of heat dissipation paths that diffuse outward from the end of the surface of the semiconductor laser element 10 that faces the base 70, thereby improving the heat dissipation performance of the semiconductor laser element 10.

[0051] 1 , the maximum height h1 of the extension 50e from the base 70 may be greater than the minimum distance d1 from the base 70 to the device bonding layer 43. In other words, the maximum thickness of the extension 50e of the metal film 50 may be greater than the minimum thickness of the portion of the metal film 50 that contacts the second electrode 40 and the base electrode 60. This allows the extension 50e to block part of the leaked light (spontaneous emission light) from the side surface 10Sc of the semiconductor laminate 10S.

[0052] In this embodiment, the metal film 50 is in contact with the insulating film 15 on the stack recess 10T, but it does not have to be in contact with the insulating film 15. This makes it possible to prevent the metal film 50 from contacting the pn junction exposed in the stack recess 10T.

[0053] The metal film 50 may be disposed in the groove 14T of the semiconductor stack 10S. In other words, a portion of the metal film 50 may be disposed at a position facing a side surface of the ridge stripe 14R extending along the resonance direction.

[0054] The base electrode 60 is a conductive member disposed between the metal film 50 and the base 70. The base electrode 60 is disposed on the first main surface 70a of the base 70. The base electrode 60 has a base bonding layer 62. In this embodiment, the base electrode 60 further has a base adhesion layer 61.

[0055] The base adhesion layer 61 is a conductive layer disposed between the base 70 and the base bonding layer 62. In this embodiment, the base adhesion layer 61 contacts the first main surface 70a of the base 70. The base adhesion layer 61 may have the function of increasing the adhesion between the first main surface 70a of the base 70 and the base bonding layer 62. The base adhesion layer 61 may be, for example, a single layer film made of Ti, Cr, or Ni. These materials that have the function of increasing adhesion have low thermal conductivity and are disadvantageous in terms of heat dissipation. Therefore, the thickness may be as thin as possible. In this embodiment, the base adhesion layer 61 is a Ti film having a thickness of 0.1 μm or less.

[0056] The substrate bonding layer 62 is disposed between the metal film 50 and the substrate 70 and is a conductive layer made of a single metal element. As described above in the description of the element bonding layer 43, the substrate bonding layer 62 may be selected from Au, Ag, Cu, or Al. All of these metals have a thermal conductivity of 200 W·m －１ ・K －１ These metals have values ​​above 100. Among metallic materials, these metals are characterized by their particularly high thermal conductivity.

[0057] Furthermore, a part or all of the base bonding layer 62 contacts the metal film 50, which is a sintered body, to form a continuum. For this reason, the base bonding layer 62 may be composed of the same metal element as the metal film 50. This increases the bonding strength between the base bonding layer 62 and the metal film 50. However, since a sintered body of Ag, for example, also forms a continuum with metals other than Ag, the base bonding layer 62 does not necessarily have to be made of the same metal as the metal film 50.

[0058] Furthermore, in this embodiment, the first bonding layer 30 includes a single base bonding layer 62, but may include multiple base bonding layers. For example, the first bonding layer 30 may include a base bonding layer 62 made of Au as well as a base bonding layer made of Cu. The multiple base bonding layers do not need to be adjacent. Depending on the purpose, other layers, such as an adhesive layer, may be inserted between the two base bonding layers. However, metal layers other than Au, Ag, Cu, and Al have low thermal conductivity and therefore hinder heat dissipation. Therefore, the metal layers other than Au, Ag, Cu, and Al may be formed as thin as possible. In this embodiment, the base bonding layer 62 is an Au film with a thickness of 0.3 μm or less.

[0059] The total thickness of the element bonding layer 43, the metal film 50, and the base bonding layer 62 included in the first bonding layer 30 is 80% or more of the thickness of the first bonding layer 30. In this way, by increasing the thickness ratio of the portion of the first bonding layer 30 that is made of a single metal element, the electrical resistance of the first bonding layer 30 can be reduced. Therefore, the ohmic loss and the amount of heat generated in the light-emitting device 1 can be reduced.

[0060] The base 70 is a base to which the semiconductor laser element 10 is bonded. The base 70 has a first main surface 70a to which the semiconductor laser element 10 is bonded and a second main surface 70b located on the back side of the first main surface 70a. In this embodiment, the base 70 has a rectangular parallelepiped shape. The light-emitting device 1 according to this embodiment is often used in a state in which it is electrically connected to one or more other light-emitting devices 1. For example, multiple light-emitting devices 1 are mounted on a metal heat sink and electrically connected to each other in series or in parallel. When the series or parallel connection of multiple light-emitting devices 1 can be simply achieved by connecting wires, the base 70 of each of the multiple light-emitting devices 1 may be made of an electrically insulating material. The semiconductor laser element 10 used in this embodiment is a GaN-based semiconductor laser element mainly made of GaN. The thermal expansion coefficient of GaN is 3×10 －６ K －１ On the other hand, the thermal expansion coefficients of Cu and Al, which are often used for heat sinks, are about 17 × 10 －６ K －１, and 23 × 10 －６ K －１ , which is much larger than that of GaN. If the semiconductor laser element 10 is directly mounted on such a metal material, a large thermal strain will occur in the semiconductor laser element 10. Therefore, the thermal strain can be alleviated by connecting the semiconductor laser element 10 to a heat sink via a base 70 made of SiC ceramic, AlN ceramic, or the like. The thermal expansion coefficient of these materials is 4×10 －６ K －１ This is because the thickness is about the same as that of GaN.

[0061] Alternatively, the base 70 can be made of tungsten (W), an alloy of copper and tungsten (CuW), molybdenum (Mo), or an alloy of copper and molybdenum (CuMo), which has a small thermal expansion coefficient. However, since these materials are conductive, connecting multiple light-emitting devices 1 in series or parallel requires some ingenuity, such as inserting an insulator between the light-emitting device 1 and the heat sink.

[0062] When a laser array element called a laser bar is used as the semiconductor laser element, the semiconductor laser element may be directly bonded to a heat sink made of Cu, but thermal distortion still remains an issue.

[0063] From the viewpoint of heat dissipation, the thermal conductivity is 1000 W·m －１ ・K －１ Synthetic diamond having the above values ​​can also be used for the substrate 70. Furthermore, single crystal SiC can also be used if it has a sufficiently high electrical resistance. These materials do not have a high thermal expansion coefficient like metals, and are therefore useful as materials for the substrate 70. In this embodiment, the substrate 70 is made of SiC ceramic.

[0064] As described above, when a GaN-based semiconductor laser element is used as the semiconductor laser element 10, the operating voltage is higher and the WPE (Wall-Plug Efficiency) is lower than, for example, a GaAs-based semiconductor laser element, etc. Accordingly, the amount of heat generated by the semiconductor laser element 10 increases, and the effect of reducing the thermal resistance of the first bonding layer 30 of the light-emitting device 1 described above becomes greater.

[0065] [1-2. Overall Configuration of Light-Emitting Module] The light-emitting module according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a schematic cross-sectional view showing the overall configuration of a light-emitting module 5 according to this embodiment. Fig. 2 shows a cross section perpendicular to the propagation direction of light emitted by the light-emitting module 5.

[0066] As shown in FIG. 2 , the light emitting module 5 according to this embodiment includes the light emitting device 1 , a heat sink 90 , and a second bonding layer 80 .

[0067] The light emitting device 1 shown in FIG. 2 includes a relay electrode 71 and a back surface metal layer 76 in addition to the components of the light emitting device 1 shown in FIG.

[0068] The relay electrode 71 is an electrode disposed on the base 70. The relay electrode 71 is electrically insulated from the base electrode 60. In the present embodiment, the relay electrode 71 is disposed on the first main surface 70a of the base 70. The relay electrode 71 may be used to relay a power supply path for supplying power to the first electrode 20. For example, as shown in FIG. 2 , a wire W connected to a power supply (not shown) and a wire W connected to the first electrode 20 may be bonded to the relay electrode 71. In the example shown in FIG. 2 , the wire W connected to the power supply is connected to the base electrode 60. These wires W are an example of power supply conductors for supplying power to the semiconductor laser device 10.

[0069] In this embodiment, the relay electrode 71 has a base adhesion layer 72 and a pad electrode layer 73. The relay electrode 71 may have the same layer structure as the base electrode 60. The relay electrode 71 may also be formed simultaneously with the base electrode 60 in the same process. The light-emitting device 1 does not necessarily have to include the relay electrode 71. In this case, for example, a wire W may be bonded directly from a power source to the first electrode 20.

[0070] The back surface metal layer 76 is a metal layer disposed on the second main surface 70b of the base 70. The back surface metal layer 76 may have a function of increasing the adhesion between the base 70 and the heat sink 90. ​​In the present embodiment, the back surface metal layer 76 has a back surface adhesion layer 77 and a back surface bonding layer 78.

[0071] The back surface adhesion layer 77 is a metal layer disposed between the base 70 and the back surface bonding layer 78. In the present embodiment, the back surface adhesion layer 77 contacts the second main surface 70b of the base 70. The back surface adhesion layer 77 may have a function of increasing adhesion between the second main surface 70b of the base 70 and the back surface bonding layer 78. The back surface adhesion layer 77 may be a single layer film made of, for example, Ti, Cr, or Ni. In the present embodiment, the back surface adhesion layer 77 is a Ti film having a thickness of 0.1 μm or less.

[0072] The back surface bonding layer 78 is a conductive layer disposed between the base 70 and the second bonding layer 80. In the present embodiment, the back surface bonding layer 78 is a layer made of a single metal element. The back surface bonding layer 78 may be, for example, a single-layer film made of Au. In the present embodiment, the back surface bonding layer 78 is an Au film having a thickness of 0.3 μm or less.

[0073] The heat sink 90 is a member for dissipating heat generated by the light-emitting device 1. The heat sink 90 also functions as a mounting base on which the light-emitting device 1 is mounted. The base 70 of the light-emitting device 1 is bonded to the heat sink 90. ​​The heat sink 90 has, for example, a plate shape and is made of a material with high thermal conductivity such as Cu or Al. In addition, the heat sink 90 may have a surface treatment layer made of, for example, Ni, Cr, or Au, which has good adhesion to the second bonding layer 80, formed on the surface facing the second bonding layer 80.

[0074] The second bonding layer 80 is a bonding member that bonds the base 70 and the heat sink 90. ​​In this embodiment, the second bonding layer 80 is disposed between the heat sink 90 and the back metal layer 76. The heat sink 90 is bonded to the second main surface 70b of the base 70 via the back metal layer 76. The melting point of the second bonding layer 80 must be lower than that of the first bonding layer 30. In this embodiment, a sintered body with a high melting point is used for the metal film 50 of the first bonding layer 30. Therefore, a material with a relatively high melting point can be selected for the second bonding layer 80. The second bonding layer 80 is made of, for example, AuSn, SnAgCu, or the like, and can firmly bond the base 70 and the heat sink 90. ​​Using these materials requires heating to nearly 300°C, but the heat treatment can be performed without melting the first bonding layer 30. In this embodiment, the second bonding layer 80 is an AuSn film with a thickness of 5 μm or less.

[0075] [1-3. Manufacturing Method of Light-Emitting Device and Light-Emitting Module] First, a manufacturing method of the light-emitting device 1 according to the present embodiment will be described with reference to Fig. 3 to Fig. 13. Fig. 3 to Fig. 11 and Fig. 13 are schematic cross-sectional views showing each step of the manufacturing method of the light-emitting device 1 according to the present embodiment. Fig. 12 is a schematic perspective view showing a ninth step of the manufacturing method of the light-emitting device 1 according to the present embodiment.

[0076] 3, a semiconductor stack 10S is formed above a substrate 11. The semiconductor stack 10S can be formed by, for example, MOCVD (Metal Organic Chemical Vapor Deposition) or the like.

[0077] Next, as shown in FIG. 4 , a stack recess 10T, a protrusion 14W, a groove 14T, and a ridge stripe 14R are formed in the semiconductor stack 10S. Specifically, the stack recess 10T and the groove 14T are formed in the semiconductor stack 10S using photolithography, etching, and the like. The stack recess 10T is formed on both side surfaces of the semiconductor stack 10S. Two grooves 14T are also formed. As a result, a protrusion 14W is formed between the stack recess 10T and the groove 14T, and a ridge stripe 14R is formed between the two grooves 14T. The stack recess 10T may be part of an isolation groove formed when the semiconductor laser device 10 is singulated. If the stack recess 10T is an isolation groove, the depth of the groove is deeper than the depth from the back surface 10Sb of the semiconductor stack 10S to the pn junction. Therefore, the pn junction is less likely to be altered by processing during device separation by dicing or the like.

[0078] Subsequently, as shown in Fig. 5, an insulating film 15 is formed. In this embodiment, by using a chemical vapor deposition (CVD) method and etching, the insulating film 15 is disposed on the entire upper surface of the semiconductor stack 10S shown in Fig. 5 except for the upper surface of the ridge stripe 14R.

[0079] 6, an element bonding layer 43 is formed on the semiconductor laser element 10 (element bonding layer forming step). In this embodiment, a second electrode 40 including the element bonding layer 43 is formed above the semiconductor stack 10S. Specifically, each layer of the second electrode 40 is formed by photolithography, vapor deposition, or the like.

[0080] 7, a first electrode 20 is formed on the rear surface of the substrate 11 (i.e., one of the two main surfaces of the substrate 11, the main surface on the rear side of the main surface on which the semiconductor stack 10S is disposed). Specifically, each layer of the first electrode 20 is formed by photolithography, vapor deposition, or the like.

[0081] 8, a base bonding layer 62 is formed on the base 70 (base bonding layer forming step). In this embodiment, a base electrode 60 including the base bonding layer 62 and a relay electrode 71 are formed on the first main surface 70a of the base 70. Specifically, the base electrode 60 and the relay electrode 71 are formed by photolithography, vapor deposition, or the like. Note that the base electrode 60 and the relay electrode 71 may be formed simultaneously in the same step.

[0082] 9, a rear surface metal layer 76 is formed on the second main surface 70b of the base 70. Specifically, the rear surface metal layer 76 is formed by photolithography, vapor deposition, or the like.

[0083] 10, a paste 50P in which metal particles are dispersed in a solvent is applied onto the base bonding layer 62 (application step). In this embodiment, the paste 50P is patterned when it is applied in the application step. This reduces the amount of paste 50P used and the time required to manufacture the light-emitting device 1 compared to, for example, applying the paste 50P to the entire first main surface 70a and then patterning it. The application step may be performed using any method, including, for example, a transfer pin, silk screen printing, a dispenser method, and inkjet printing.

[0084] The viscosity of the paste 50P may be, for example, 10 Pa·s or more. This reduces the amount of solvent contained in the paste 50P, thereby suppressing deformation of the paste 50P due to volume reduction during heating. Furthermore, the heating time required for sintering the paste 50P can be reduced.

[0085] 11 and 12 , the element bonding layer 43 formed on the semiconductor laser element 10 is placed on the paste 50P (placement step). In this embodiment, as shown in Fig. 12 , the semiconductor laser element 10 is placed so that the light emission surface 10E protrudes from the edge 70E of the first main surface of the base 70. This makes it possible to prevent the base 70 from blocking the emitted light of the semiconductor laser element 10.

[0086] Furthermore, the entire surface of the laminate recess 10T is covered with the insulating film 15. That is, the insulating film 15 covers the first semiconductor layer 12 in the laminate recess 10T. This prevents a short circuit from occurring between the pn layers of the semiconductor laminate even if the paste 50P containing metal fine particles that protrudes toward the side surfaces of the semiconductor laminate 10S in the placement step extends into the laminate recess 10T.

[0087] 13, the paste 50P is heated and sintered to form the metal film 50 (sintering process). Specifically, the base 70 is heated in a baking oven or the like at 200°C for about 30 minutes, and then cooled. This forms the metal film 50, which is a sintered body of metal microparticles, and the metal film 50 bonds the element bonding layer 43 and the base bonding layer 62. In other words, the base 70 and the semiconductor laser element 10 can be bonded. By using such a metal film 50, bonding can be performed at a relatively low temperature, as described above. Therefore, damage to the semiconductor laser element 10 due to heating can be reduced.

[0088] The manufacturing method of the light-emitting device 1 may include a removal step of removing the solvent by heating the paste 50P between the application step and the placement step. This stabilizes the amount of solvent contained in the paste 50P in the placement step, thereby suppressing variations in the characteristics of the light-emitting device 1 due to the shape of the paste 50P, which is affected by fluctuations in the waiting time before the placement step.

[0089] By the manufacturing method described above, the light emitting device 1 shown in FIG. 2 can be formed.

[0090] Next, a method for manufacturing a light-emitting module 5 including the light-emitting device 1 will be described with reference to Figures 14 to 16. Figures 14 to 16 are schematic cross-sectional views showing the steps of the method for manufacturing a light-emitting module 5 according to this embodiment.

[0091] First, as shown in FIG. 14, the second bonding layer 80 is disposed on the heat sink 90 (second bonding layer disposing step).

[0092] 15 , the base 70 of the light-emitting device 1 is placed on the second bonding layer 80 (base placement step). Specifically, the light-emitting device 1 is placed on the second bonding layer 80 so that the second main surface 70b of the base 70 faces the second bonding layer 80. Here, the base 70 may be pressed against the heat sink 90. ​​This can improve adhesion between the back surface metal layer 76, which is placed on the second main surface 70b of the base 70, and the second bonding layer 80.

[0093] 16 , the second bonding layer 80 is heated to melt the second bonding layer 80. This bonds the base 70 to the heat sink 90 (bonding process). Specifically, the heat sink 90 is heated to 300° C. in a baking oven or the like for about 1 minute, and then cooled. This allows the heat sink 90 and the back surface metal layer 76 to be bonded together by the second bonding layer 80. In other words, the base 70 and the heat sink 90 can be bonded together.

[0094] The light-emitting module 5 shown in FIG. 2 can be manufactured through the above process. In the light-emitting device 1 according to this embodiment, a high-melting-point sintered metal film 50 is used for the first bonding layer 30. This greatly expands the material options for the second bonding layer 80 that bonds the light-emitting device 1 to the heat sink 90. ​​In this embodiment, the use of AuSn solder, which has a relatively high melting point, allows the light-emitting device 1 to be firmly bonded to the heat sink 90. ​​In the light-emitting device 1, the first bonding layer 30 connecting the semiconductor laser element 10 to the base 70 does not remelt. This prevents changes in the relative position and orientation of the semiconductor laser element 10 with respect to the base 70. Since changes in the bonding state between the semiconductor laser element 10 and the base 70 can be suppressed, the manufacturing process for the light-emitting module 5 can be completed while suppressing changes in the initial heat dissipation performance. In other words, changes in the basic characteristics of the semiconductor laser element 10 can be suppressed even after the mounting process on the heat sink 90.

[0095] Heat generated in the semiconductor laser element 10 is locally concentrated in the strip-shaped area corresponding to the position of the ridge stripe 14R. This is because the current required to drive the laser is concentrated in the area of ​​the ridge stripe 14R. Furthermore, since the guided light is also confined in the region corresponding to this area, heat generated by scattering and absorption is also concentrated in this area. This is significantly different from general electronic devices and light-emitting diodes, in which heat sources are widely distributed within the element surface.

[0096] To achieve high heat dissipation performance using a semiconductor laser element 10 having such a localized heat source, the thermal resistance of the portion adjacent to the semiconductor laser element 10, i.e., the first bonding layer 30 in this embodiment, is extremely important. The ability to rapidly expand the heat dissipation path from the strip-shaped heat source laterally significantly affects the thermal resistance of the entire heat dissipation path of the light-emitting module 5. If the heat dissipation path cannot be rapidly expanded laterally, only a portion of the area of ​​the base 70 functions as a heat dissipation path, making it impossible to reduce the thermal resistance of the entire system. This problem is more pronounced the narrower the width of the ridge stripe 14R, and is particularly pronounced when the width of the ridge stripe 14R is 100 μm or less. The same is true when a metal material is used for the base 70; reducing the thermal resistance of the first bonding layer 30, including the base bonding layer 62 formed on the surface of the base 70, is important.

[0097] In this embodiment, by using a single element layer of Au, which has high thermal conductivity, for element bonding layer 43, sintered body metal film 50, and base bonding layer 62, a configuration is adopted in which the total thickness of the layers of first bonding layer 30 made of a single metal element of any of Au, Ag, Cu, and Al is 80% or more of the entire thickness of first bonding layer 30. This effectively reduces the thermal resistance of first bonding layer 30, thereby expanding the heat dissipation path in the lateral direction. This allows the thermal resistance of the entire light-emitting device 1 to be lowered.

[0098] Furthermore, the heating temperature in the sintering step may be lower than the heating temperature in the bonding step, thereby reducing damage to the semiconductor laser element 10 due to heating in the sintering step.

[0099] (Embodiment 2) A light-emitting module according to embodiment 2 and a method for manufacturing the same will be described. The light-emitting module according to this embodiment differs from the light-emitting module 5 according to embodiment 1 mainly in that it combines and outputs multiple laser beams from multiple light-emitting devices 1 and that the light-emitting devices 1 are hermetically sealed. Furthermore, since multiple light-emitting devices 1 are mounted, the volume of the components corresponding to the heat sink (the multi-stage base 190 and module substrate 112, described below) inevitably increases. As the volume of the components increases, their thermal capacity also increases, making rapid heating and cooling difficult. Heating and cooling when mounting the light-emitting devices 1 requires more time. In this case, the effect of connecting the semiconductor laser element 10 and the base 70 with the metal film 50 of a sintered body with a high melting point becomes more pronounced. A light-emitting module according to this embodiment and a method for manufacturing the same will be described below.

[0100] [2-1. Overall Configuration of Light-Emitting Module] The overall configuration of the light-emitting module according to this embodiment will be described with reference to Fig. 17. Fig. 17 is a schematic perspective view showing the overall configuration of light-emitting module 106 according to this embodiment.

[0101] As shown in Figure 17, the light-emitting module 106 includes a module substrate 112, a frame body 113, a multi-stage base 190, six light-emitting devices 1, six fast-axis collimator lenses 120, six slow-axis collimator lenses 121, six reflecting mirrors 122, a condenser lens 123, an optical fiber 124, and two current input terminals 140.

[0102] The module substrate 112 is a plate-like member that serves as a base for the light-emitting module 106. The module substrate 112 is made of, for example, Cu or Al. The module substrate 112 is used by being fixed to, for example, a temperature control stage using a Peltier element, a cooling stage equipped with a water-cooling mechanism, or the like (not shown).

[0103] The frame 113 is an annular side wall that is erected on the module substrate 112. In this embodiment, the frame 113 has a rectangular annular shape. In Fig. 17, a portion of the frame 113 is cut away to show the internal configuration of the frame 113 of the light-emitting module 106. The frame 113 is made of an Fe-based material such as Fe, an FeNi alloy, or stainless steel.

[0104] Although not shown in Fig. 17 , the light-emitting module 106 is disposed on a frame 113 and includes a plate-shaped lid that covers the opening of the frame 113 (see the lid 114 shown in Fig. 22 , which will be described later). The lid is made of an Fe-based material, such as Fe, an FeNi alloy, or stainless steel. The module substrate 112, the frame 113, and the lid form a housing. The light-emitting device 1 and other components are disposed inside the housing.

[0105] The current introduction terminals 140 are terminals for introducing current from the outside of the frame body 113 to the inside of the frame body 113. One end of each of the two current introduction terminals 140 is disposed outside the frame body 113, and the other end is disposed inside the frame body 113. In the present embodiment, the current introduction terminals 140 are disposed in the frame body 113 and penetrate the frame body 113. If the frame body 113 is formed of a conductive material, an insulating member is disposed between the current introduction terminals 140 and the frame body 113.

[0106] The multi-stage base 190 and the module substrate 112 correspond to the heat sink in the first embodiment. The multi-stage base 190 is a member having a plurality of laser mounting surfaces 191 and a plurality of optical element mounting surfaces 192. In the present embodiment, the multi-stage base 190 has six flat, rectangular laser mounting surfaces 191 and six flat, rectangular optical element mounting surfaces 192. The multi-stage base 190 has six staircase-like steps. The six laser mounting surfaces 191 correspond to step surfaces (surfaces parallel to the main surface of the module substrate 112) of the plurality of staircase-like steps. The six laser mounting surfaces 191 are at different heights from the module substrate 112. The six optical element mounting surfaces 192 correspond to step surfaces of the plurality of staircase-like steps. The six laser mounting surfaces 191 are at different heights from the module substrate 112. Each of the six laser mounting surfaces 191 is adjacent to each of the six optical element mounting surfaces 192. In this embodiment, the six laser mounting surfaces 191 and the six optical element mounting surfaces 192 are at different heights from the module substrate 112, but they may also be at the same height. The multi-stage base 190 is made of, for example, Cu, Al, or the like. In this embodiment, the six laser mounting surfaces 191 and the six optical element mounting surfaces 192 of the multi-stage base 190 are plated with Au. This makes it easier to join the laser mounting surfaces 191 and the optical element mounting surfaces 192 with solder such as AuSn.

[0107] Each of the six light-emitting devices 1 has the same configuration as the light-emitting device 1 according to the first embodiment. The six light-emitting devices 1 are respectively arranged on six laser mounting surfaces 191 of a multi-stage base 190. Each of the six light-emitting devices 1 emits laser light above an adjacent optical element mounting surface 192 in parallel to the optical element mounting surface 192. The optical axes of the six laser lights emitted from the six light-emitting devices 1 are parallel to one another.

[0108] Power is supplied to each of the six light-emitting devices 1 from the current input terminals 140. The six light-emitting devices 1 are connected in series between two of the current input terminals 140. This reduces the output current of the power supply for supplying power. The six light-emitting devices 1 may also be connected in parallel.

[0109] A wire (not shown), for example, can be used as a power supply conductor connecting the current introduction terminal 140 and the light emitting device 1, and connecting two light emitting devices 1. The wire is bonded to the current introduction terminal 140 and the light emitting device 1 inside the frame body 113.

[0110] Each of the six fast-axis collimator lenses 120 is a lens that collimates the laser light emitted from the light-emitting device 1 in the fast-axis direction (in the present embodiment, a direction perpendicular to the laser installation surface 191). The six fast-axis collimator lenses 120 are disposed near the light-emitting surfaces of the six light-emitting devices 1, respectively. Each of the six fast-axis collimator lenses 120 may be disposed on the base 70 of the light-emitting device 1 or on the laser installation surface 191.

[0111] Each of the six slow-axis collimator lenses 121 is a lens that collimates the laser light emitted from the fast-axis collimator lens 120 in the slow-axis direction (a direction perpendicular to the fast-axis direction and the propagation direction of the laser light). The six slow-axis collimator lenses 121 are arranged on the six optical element mounting surfaces 192, respectively. Each of the six slow-axis collimator lenses 121 collimates the laser light (laser light emitted from the fast-axis collimator lens 120) from the light-emitting device 1 arranged on the laser mounting surface 191 adjacent to the optical element mounting surface 192 on which the six slow-axis collimator lenses 121 are arranged.

[0112] Each of the six reflecting mirrors 122 has the role of changing the traveling direction of the laser light emitted from the slow-axis collimator lens 121. The six reflecting mirrors 122 are arranged on six optical element mounting surfaces 192, respectively. In this embodiment, each of the six reflecting mirrors 122 bends the traveling direction of the laser light by 90 degrees. As a result, the laser light emitted from each of the six reflecting mirrors 122 enters the condenser lens 123. Note that the optical axes of the six laser light beams emitted from the six reflecting mirrors 122, respectively, are parallel to one another.

[0113] The six reflecting mirrors 122 are arranged on six optical element mounting surfaces 192 at different heights from the module substrate 112, and the optical axes of the six laser beams incident on the six reflecting mirrors 122 are also at different heights from the module substrate 112. Therefore, the optical axes of the six laser beams output from the six reflecting mirrors 122 are at different heights from the module substrate 112. Therefore, the six laser beams output from the six reflecting mirrors 122 can enter the condenser lens 123 without interfering with the six reflecting mirrors 122.

[0114] The condenser lens 123 is a lens that condenses the six laser beams reflected by the six reflecting mirrors 122. In this embodiment, the condenser lens 123 condenses the six laser beams so that most of the six laser beams are incident on the end face of the optical fiber 124 and can propagate through the optical fiber 124. In other words, the six laser beams are spatially multiplexed. As the condenser lens 123, for example, an aspherical lens can be used.

[0115] The optical fiber 124 is a member that guides the laser light from the inside to the outside of the frame body 113. As described above, the six laser light beams emitted from the condenser lens 123 are incident on the end face of the optical fiber 124 that is arranged inside the frame body 113.

[0116] The light-emitting module 106 having such a configuration can realize a high-power laser light source. In the example shown in Fig. 17, the number of light-emitting devices 1 is six, but the number of light-emitting devices 1 is not limited to six and may be two or more.

[0117] 2-2. Manufacturing Method of Light-Emitting Module A manufacturing method of light-emitting module 106 according to this embodiment will be described with reference to Fig. 18 to Fig. 22. Fig. 18 to Fig. 22 are schematic perspective views showing each step of the manufacturing method of light-emitting module 106 according to this embodiment.

[0118] 18 , a multistage base 190 and a frame 113 on which a current introducing terminal 140 is disposed are mounted on a module substrate 112. A second bonding layer 80 is disposed on each of six laser mounting surfaces 191 of the multistage base 190. Six light-emitting devices 1 are disposed on the second bonding layer 80 disposed on each of the six laser mounting surfaces 191.

[0119] Next, as shown in FIG. 19 , six light-emitting devices 1 are placed on six laser mounting surfaces 191, respectively, and heated while each light-emitting device 1 is pressed against the corresponding laser mounting surface 191. In this embodiment, the second bonding layer 80 is melted by heating at a temperature of 300°C or higher and 350°C or lower for approximately 1 minute to 60 minutes. The heating temperature and heating time are set appropriately depending on the volume of the module substrate 112 and the multistage base 190, which correspond to the heat sink. As mentioned above, as the volume of the heat sink increases, the thermal capacity also increases, making rapid heating and cooling difficult. Therefore, the heating conditions must be higher temperature and longer time. In conventional light-emitting devices in which the semiconductor laser element and the base are connected by solder, it is difficult to set appropriate heating conditions due to the risk of the solder remelting. However, the light-emitting device 1 according to this embodiment uses a sintered metal film 50 instead of solder. Because there is no risk of remelting, heating conditions can be set at higher temperatures and for longer periods.

[0120] Subsequently, by cooling the multi-stage base 190 and the like, each light-emitting device 1 can be bonded to each laser installation surface 191 by the second bonding layer 80. In the present embodiment, the second bonding layer 80 is made of solder made of AuSn.

[0121] Although not shown, following this step, the six light-emitting devices 1 are connected in series by wire bonding, and the light-emitting devices 1 at both ends of the series connection are connected to the two current input terminals 140 by wire bonding, respectively.

[0122] 20 , the optical fiber 124 is connected to a predetermined position on the frame 113. Furthermore, the condenser lens 123 is fixed to a predetermined position on the module substrate 112, and the reflecting mirror 122 is fixed to a predetermined position on each optical element mounting surface 192. For example, solder made of SnAgCu is used for the fixing, and the solder is heated at 250° C. for 1 minute to 60 minutes, followed by cooling. The SnAgCu solder has a lower melting point than the AuSn solder used for the second bonding layer 80. Therefore, the second bonding layer 80 made of AuSn does not remelt when heated at this temperature.

[0123] Next, the fast-axis collimator lens 120 is temporarily placed on each light-emitting device 1, and the slow-axis collimator lens 121 is temporarily placed at a predetermined position on each optical element mounting surface 192. In this state, active alignment is performed for each fast-axis collimator lens 120 and each slow-axis collimator lens 121. That is, laser light is emitted from each light-emitting device 1, and the position and attitude of each fast-axis collimator lens 120 and each slow-axis collimator lens 121 are adjusted while monitoring the amount of laser light output from the light-emitting end of the optical fiber 124.

[0124] After the active alignment is completed, the fast-axis collimator lenses 120 and the slow-axis collimator lenses 121 are fixed. For example, solder made of In or InSn is used to fix these lenses, and they are heated at 170°C for 1 minute to 60 minutes, followed by cooling. In or InSb solder has a lower melting point than the AuSn solder used for the second bonding layer 80 and the AnAgCu solder used to fix the reflecting mirror 122. Therefore, when heated at this temperature, the second bonding layer 80 made of AuSn and the solder made of SnAgCu do not remelt.

[0125] 21 , the module substrate 112 to which the light-emitting device 1 and the like are bonded and the lid 114 are placed in an ozone atmosphere for a predetermined time, thereby removing organic matter adhering to the surfaces of the module substrate 112 and the components bonded to the module substrate 112.

[0126] Immediately after removing the organic matter, the inside of the frame 113 is hermetically sealed. Specifically, for example, the module substrate 112 to which the light-emitting device 1 and the like are joined and the lid 114 are placed in a clean, dry air atmosphere. Next, the lid 114 and the upper surface of the frame 113 are joined by seam welding.

[0127] 22 can be manufactured. In the light-emitting module 106, components such as the light-emitting device 1 are sealed in the internal space of the light-emitting module 106, which is filled with clean, dry air. This allows the components inside the light-emitting module 106 to be kept clean.

[0128] In the light-emitting module according to the present embodiment, the light-emitting device 1 is hermetically sealed. This prevents foreign matter, such as organic matter, from adsorbing near the light-emitting portion of the semiconductor laser element 10 due to the optical tweezers effect while the light-emitting device 1 is emitting light. This allows for a highly reliable light-emitting module 106. Furthermore, in the light-emitting module 106, components such as the light-emitting device 1 are fixed with a bonding material made of an inorganic material, such as a sintered metal film or solder, and then hermetically sealed. Therefore, compared to when a bonding material made of an organic material, such as an ultraviolet-curing resin, is used, it is possible to further prevent foreign matter from adsorbing near the light-emitting portion of the semiconductor laser element 10. Furthermore, the light-emitting device 1 is fixed to a heat sink made up of the multi-stage base 190 and the module substrate 112. This allows Joule heat generated in the hermetically sealed light-emitting device 1 to be dissipated to the outside of the light-emitting module 106 through the heat sink. Furthermore, the semiconductor laser element 10 and the base 70 are connected by a first bonding layer 30 with high thermal conductivity. Therefore, the Joule heat generated in the semiconductor laser element 10 can be efficiently dissipated to the outside of the light emitting module 106 through the heat sink.

[0129] (Embodiment 3) A light-emitting module according to embodiment 3 and a method for manufacturing the same will be described. The light-emitting module according to this embodiment differs from the light-emitting module 106 according to embodiment 2 in that only one light-emitting device 1 is hermetically sealed. The light-emitting module according to this embodiment and a method for manufacturing the same will be described below.

[0130] [3-1. Overall Configuration of Light-Emitting Module] The overall configuration of the light-emitting module according to this embodiment will be described with reference to Fig. 23. Fig. 23 is a schematic perspective view showing the overall configuration of a light-emitting module 206 according to this embodiment.

[0131] 23 , the light-emitting module 206 includes a module substrate 290, a frame 213, a light-transmitting window 215, the light-emitting device 1, and two current input terminals 240. The light-emitting device 1 according to the present embodiment also includes a semiconductor laser element 10, a base 70, and a first bonding layer 30, similar to the first embodiment.

[0132] The module substrate 290 is a plate-like member that serves as a base for the light-emitting module 206. The module substrate 290 is made of a material with high thermal conductivity, such as Cu or Al. The module substrate 290 corresponds to the heat sink of the first embodiment.

[0133] The frame body 213 is an annular side wall that is erected on the module substrate 290. A through-hole (not shown) is formed in the frame body 213, penetrating a portion of the frame body 213 in a direction along the upper surface of the module substrate 290. This through-hole is a through-hole for extracting laser light emitted from the light-emitting device 1 arranged inside the frame body 213 to the outside of the frame body 213. The through-hole is covered with a light-transmitting window 215. The frame body 213 is made of an Fe-based material, such as Fe, an FeNi alloy, or stainless steel.

[0134] Although not shown in Figure 23, the light-emitting module 206 is disposed on a frame 213 and includes a plate-shaped lid that covers the opening of the frame 213 (see the lid 214 shown in Figure 25 described later). The lid is made of an Fe-based material such as Fe, an FeNi alloy, or stainless steel. The module substrate 290, the frame 213, and the lid form a housing. The light-emitting device 1 is disposed inside the housing.

[0135] The light-transmitting window 215 is a window for allowing the laser light emitted from the light-emitting device 1 to exit the frame 213. The light-transmitting window 215 is a plate-shaped member made of, for example, glass.

[0136] The current introduction terminals 240 are terminals for introducing current from the outside of the frame body 213 to the inside of the frame body 213. One end of each of the two current introduction terminals 240 is disposed outside the frame body 213, and the other end is disposed inside the frame body 213. In the present embodiment, the current introduction terminals 240 are disposed on the frame body 213 and penetrate the frame body 213. If the frame body 213 is formed of a conductive material, an insulating member is disposed between the current introduction terminals 240 and the frame body 213. The current introduction terminals 240 and the light-emitting device 1 are electrically connected by a metal wire (not shown).

[0137] 3-2. Manufacturing Method of Light-Emitting Module A manufacturing method of light-emitting module 206 according to this embodiment will be described with reference to Fig. 24 and Fig. 25. Fig. 24 and Fig. 25 are schematic perspective views showing each step of the manufacturing method of light-emitting module 206 according to this embodiment.

[0138] 24 , a frame 213 on which a current introducing terminal 240 is arranged is placed on a module substrate 290. The through-hole of the frame 213 is covered with a light-transmitting window 215. The module substrate 290 also has a flat laser mounting surface 291, and the second bonding layer 80 is placed on the laser mounting surface 291. The light-emitting device 1 is placed on the second bonding layer 80.

[0139] Next, the light-emitting device 1 is placed on the laser mounting surface 291, and the module substrate 290 is heated while the light-emitting device 1 is pressed against the laser mounting surface 291. In this embodiment, the second bonding layer 80 is melted by heating at 300° C. for about 1 minute.

[0140] Subsequently, by cooling the module substrate 290 and the like, the light emitting device 1 can be bonded to the laser installation surface 291 by the second bonding layer 80. In this embodiment, the second bonding layer 80 is made of solder made of AuSn.

[0141] Although not shown, following this step, the light emitting device 1 and the two current input terminals 140 are connected by wire bonding.

[0142] 25, the module substrate 290 to which the light-emitting device 1 and the like are bonded and the lid 214 are placed in an ozone atmosphere for a predetermined time, thereby removing organic matter adhering to the surfaces of the module substrate 290 and each component bonded to the module substrate 290.

[0143] Immediately after removing the organic matter, the inside of the frame 213 is hermetically sealed. Specifically, for example, the module substrate 290 to which the light emitting device 1 and the like are joined and the lid 214 are placed in a clean, dry air atmosphere. Next, the lid 214 and the upper surface of the frame 213 are joined by seam welding.

[0144] This allows the light-emitting module 206 according to the present embodiment to be manufactured. In the light-emitting module 206, components such as the light-emitting device 1 are sealed in an internal space of the light-emitting module 206 filled with clean, dry air. This allows the light-emitting device 1 in the light-emitting module 206 and the surface facing the through-hole of the light-transmitting window 215 to be kept clean.

[0145] In the light-emitting module 206 according to this embodiment, the light-emitting device 1 is hermetically sealed, which prevents foreign matter such as organic matter from being adsorbed near the light-emitting portion of the semiconductor laser element 10 due to the optical tweezers effect while the light-emitting device 1 is emitting light. This allows for a highly reliable light-emitting module 206. Furthermore, the light-emitting device 1 is fixed to a heat sink made of a module substrate 290. This allows Joule heat generated in the hermetically sealed light-emitting device 1 to be dissipated to the outside of the light-emitting module 206 through the heat sink. Furthermore, the semiconductor laser element 10 and the base 70 are connected by a first bonding layer 30 with high thermal conductivity. Therefore, Joule heat generated in the semiconductor laser element 10 can be efficiently dissipated to the outside of the light-emitting module 206 through the heat sink.

[0146] [3-3. Modification] A light-emitting module according to a modification of the present embodiment will be described. The light-emitting module according to this modification differs from light-emitting module 206 according to the present embodiment described above mainly in the direction in which the laser light is emitted. The light-emitting module according to this modification will be described below, focusing on the differences from light-emitting module 206 according to the present embodiment.

[0147] [3-3-1. Overall Configuration] The overall configuration of the light-emitting module according to this modification will be described with reference to Fig. 26. Fig. 26 is a schematic cross-sectional view showing the overall configuration of light-emitting module 506 according to this modification. Fig. 26 shows a cross section parallel to the optical axis of laser light emitted by light-emitting module 506.

[0148] 26 , a light-emitting module 506 according to this modification includes a module substrate 590, a frame 513, a lid 514, a light-transmitting window 515, a light-emitting device 1, a second bonding layer 80, a reflecting mirror 522, an optical element bonding layer 581, and a current input terminal 540. Similar to the first embodiment, the light-emitting device 1 according to this embodiment also includes a semiconductor laser element 10, a base 70, and a first bonding layer 30.

[0149] The module substrate 590 is a plate-like member that serves as a base for the light-emitting module 506. The module substrate 590 is made of a material with high thermal conductivity, such as Cu or Al. The module substrate 590 corresponds to the heat sink of the first embodiment.

[0150] The frame 513 is an annular side wall that stands on the module substrate 590. The frame 513 is made of an Fe-based material such as Fe, an FeNi alloy, or stainless steel.

[0151] The lid 514 is a plate-like member that covers the opening of the frame 513. The lid 514 is made of an Fe-based material, such as Fe, an FeNi alloy, or stainless steel. A through-hole is formed in the lid 514. This through-hole is a through-hole that allows laser light emitted from the light-emitting device 1 arranged in the area surrounded by the lid 514, the frame 513, and the module substrate 590 to escape to the outside of the area. The through-hole is covered by a light-transmitting window 515.

[0152] The second bonding layer 80 bonds the base 70 of the light-emitting device 1 to the heat sink, similar to the second bonding layer 80 according to embodiment 1. In this modification, the second bonding layer 80 bonds the base 70 to the module substrate 590.

[0153] The reflecting mirror 522 is an optical element that changes the traveling direction of laser light emitted from the semiconductor laser element 10 of the light-emitting device 1. In this modification, the reflecting mirror 522 has a reflecting surface that is inclined at 45 degrees with respect to the main surface of the module substrate 590. The reflecting mirror 522 reflects the laser light traveling parallel to the main surface of the module substrate 590, thereby bending the traveling direction of the laser light by 90 degrees to a direction perpendicular to the main surface of the module substrate 590. The laser light reflected upward in FIG. 26 by the reflecting mirror 522 passes through a light-transmitting window 515 arranged in a through-hole in the lid 514, and is output to the outside of the light-emitting module 506.

[0154] The optical element bonding layer 581 is a bonding member that bonds the module substrate 590 and the reflecting mirror 522. In this modification, the optical element bonding layer 581 is disposed between the module substrate 590 and the reflecting mirror 522. A material with a relatively high melting point can be selected for the optical element bonding layer 581, similar to the second bonding layer 80. For example, AuSn, SnAgCu, or the like can be used for the optical element bonding layer 581, which can firmly bond the reflecting mirror 522 and the module substrate 590.

[0155] The current introduction terminal 540 is a terminal for introducing current from the outside of the frame body 513 to the inside of the frame body 513. The light-emitting module 506 may include two current introduction terminals 540. One end of each of the current introduction terminals 540 is disposed outside the frame body 513, and the other end is disposed inside the frame body 513. In this modification, the current introduction terminals 540 are disposed on the frame body 513 and penetrate the frame body 513. If the frame body 513 is formed of a conductive material, an insulating member is disposed between the current introduction terminal 540 and the frame body 513. The current introduction terminals 540 and the semiconductor laser element 10 of the light-emitting device 1 are connected by wires W.

[0156] According to the light-emitting module 506 of this modified example, the light-emitting device 1 can be mounted on the module substrate 590 so that the resonance direction of the semiconductor laser element 10 is parallel to the main surface of the module substrate 590, and laser light can be emitted in a direction perpendicular to the main surface of the module substrate 590.

[0157] [3-3-2. Manufacturing Method of Light-Emitting Module] A method for manufacturing light-emitting module 506 according to this modification will be described. The manufacturing method of light-emitting module 506 according to this modification differs from the manufacturing method of light-emitting module 206 according to embodiment 3 in that it includes a step of bonding reflective mirror 522 to module substrate 590.

[0158] When the optical element bonding layer 581 is made of the same material as the second bonding layer 80, the reflecting mirror 522 may be bonded to the module substrate 590 in the step of bonding the light emitting device 1 to the module substrate 590. That is, the light emitting device 1 and the reflecting mirror 522 may be bonded to the main surface of the module substrate 590 as follows. First, the second bonding layer 80 and the optical element bonding layer 581 are disposed on the main surface of the module substrate 590. Next, the light emitting device 1 is disposed on the second bonding layer 80, and the reflecting mirror 522 is disposed on the optical element bonding layer 581. Next, the module substrate 590 is heated while the light emitting device 1 and the reflecting mirror 522 are pressed against the module substrate 590. In this modification, the second bonding layer 80 and the optical element bonding layer 581 are melted by heating at 300° C. for about one minute. Subsequently, by cooling the module substrate 590 and the like, the light emitting device 1 and the reflective mirror 522 can be bonded to the module substrate 590 by the second bonding layer 80 and the optical element bonding layer 581 .

[0159] If the optical element bonding layer 581 is made of a different material from the second bonding layer 80, the reflecting mirror 522 is bonded to the module substrate 590 in a separate process from the process of bonding the light-emitting device 1 to the module substrate 590. For example, if the reflecting mirror 522 is bonded to the module substrate 590 after the process of bonding the light-emitting device 1 to the module substrate 590, a material having a lower melting point than the second bonding layer 80 is selected for the optical element bonding layer 581. For example, if AuSn solder is used for the second bonding layer 80, SnAgCu solder or the like can be used for the optical element bonding layer 581. In this way, by bonding the reflecting mirror 522 to the module substrate 590 after bonding the light-emitting device 1 to the module substrate 590, the reflecting mirror 522 can be precisely aligned with respect to the light-emitting device 1. It is also possible to align the reflecting mirror 522 while emitting laser light from the light-emitting device 1.

[0160] As described above, the light emitting module 506 according to this modification can be manufactured.

[0161] In the light-emitting module 506 according to the present embodiment, the light-emitting device 1 and the reflective mirror 522 are fixed with an inorganic material and then hermetically sealed, thereby realizing a highly reliable light-emitting module 506.

[0162] (Embodiment 4) A light emitting device and a light emitting module according to embodiment 4 will be described. The light emitting device according to this embodiment differs from the light emitting device 1 according to embodiment 1 mainly in the configuration of the metal film. The light emitting device and the light emitting module according to this embodiment will be described below with reference to FIG. 27 , focusing on the differences from the light emitting device 1 and the light emitting module 5 according to embodiment 1.

[0163] Fig. 27 is a schematic cross-sectional view showing the overall configuration of a light-emitting module 305 according to this embodiment. Fig. 27 shows a cross section perpendicular to the propagation direction of light emitted by the light-emitting module 305.

[0164] As shown in FIG. 27, a light emitting module 305 according to this embodiment includes a light emitting device 301, a heat sink 90, a second bonding layer 80, and a wire W.

[0165] The light emitting device 301 according to this embodiment differs from the light emitting device 1 according to the first embodiment shown in FIG. 2 in the configuration of the metal film 350, but is the same in other respects.

[0166] The metal film 350 according to this embodiment has an extending portion 350e that extends outward from the side surface of the semiconductor laser element 10 (i.e., the side surface 10Sc of the semiconductor stack 10S) in a direction perpendicular to the resonance direction of the semiconductor laser element 10 and the stacking direction of the first bonding layer 30. The detailed configuration of the extending portion 350e will be described later.

[0167] The wire W is an example of a power supply conductor for supplying power to the semiconductor laser element 10 included in the light-emitting device 301 .

[0168] In this embodiment, a wire W, which is an example of a power supply conductor for supplying power to the semiconductor laser device 10, is directly bonded to the extension 350e. That is, the extension 350e and the power supply conductor are bonded without any other conductive member included in the light-emitting module 305 being interposed between them. In this embodiment, the wire W is directly bonded to the extension 350e. As a result, compared to, for example, a case in which the wire W is bonded to the base electrode 60, in this embodiment, power can be supplied directly to the metal film 350 without passing through the base electrode 60, thereby reducing the electrical resistance of the light-emitting module 305. Therefore, ohmic loss and heat generation in the base electrode 60 can be reduced. This configuration is particularly effective when a large current is supplied to the semiconductor laser device 10.

[0169] The thickness of the metal film 350 may be 3 μm or more, which can further reduce the electrical resistance of the light-emitting module 305.

[0170] The width of the extension 350e (the horizontal dimension in FIG. 27) may be 50 μm or more, which makes it easier to join the power supply conductor to the extension 350e.

[0171] Furthermore, the extending portion 350e may have at least a part of the surface on the back side of the surface facing the base 70 flat, which makes it easier to join the power supply conductor to the extending portion 350e.

[0172] (Embodiment 5) A light emitting device and a light emitting module according to embodiment 5 will be described. The light emitting device according to this embodiment differs from the light emitting device 1 according to embodiment 1 mainly in the configuration of the base bonding layer. The light emitting device and the light emitting module according to this embodiment will be described below with reference to FIG. 28 , focusing on the differences from the light emitting device 1 and the light emitting module 5 according to embodiment 1.

[0173] Fig. 28 is a schematic cross-sectional view showing the overall configuration of a light-emitting module 405 according to this embodiment. Fig. 28 shows a cross section perpendicular to the propagation direction of light emitted by light-emitting module 405.

[0174] As shown in FIG. 28, a light-emitting module 405 according to this embodiment includes a light-emitting device 401, a heat sink 90, a second bonding layer 80, and a wire W.

[0175] The light emitting device 401 according to this embodiment differs from the light emitting device 1 according to the first embodiment shown in FIG. 2 in the configurations of the base electrode 460 and the relay electrode 471, but is the same in other respects.

[0176] The base electrode 460 according to the present embodiment has a base adhesion layer 61 and a base bonding layer 462. The base bonding layer 462 according to the present embodiment differs from the base bonding layer 62 according to the first embodiment in that the thickness of the base bonding layer 462 is 0.3 μm or more, but is the same in other respects.

[0177] The relay electrode 471 according to the present embodiment has a base adhesion layer 72 and a pad electrode layer 473. The pad electrode layer 473 according to the present embodiment differs from the pad electrode layer 73 according to the first embodiment in that the thickness of the pad electrode layer 473 according to the present embodiment is 0.3 μm or more, but is the same in other respects.

[0178] In the light emitting module 405 of this embodiment, a wire W, which is an example of a power supply conductor for supplying power to the semiconductor laser element 10 , is directly bonded to the base bonding layer 462 .

[0179] In this embodiment, by setting the thickness of the base bonding layer 462 to 0.3 μm or more, the electrical resistance in the direction perpendicular to the thickness direction of the base bonding layer 462 can be reduced. Therefore, by directly bonding the wire W to the base bonding layer 462, the electrical resistance in the current path from the wire W to the metal film 50 can be reduced. This reduces ohmic loss and heat generation in the base bonding layer 462. This configuration is particularly effective when a large current is supplied to the semiconductor laser device 10.

[0180] The thickness of the base bonding layer 462 may be 3 μm or more, which further reduces the electrical resistance in the direction perpendicular to the thickness direction of the base bonding layer 462.

[0181] Furthermore, since the thickness of the pad electrode layer 473 of the relay electrode 471 is 0.3 μm or more, it is possible to reduce the electrical resistance in a direction perpendicular to the thickness direction of the pad electrode layer 473. Therefore, for example, as shown in FIG. 28 , when a plurality of wires W are joined to the pad electrode layer 473 to relay a current path, it is possible to reduce the electrical resistance in the pad electrode layer 473. This makes it possible to reduce ohmic loss and heat generation in the pad electrode layer 473.

[0182] The thickness of the pad electrode layer 473 may be 3 μm or more, which can further reduce the electrical resistance in the direction perpendicular to the thickness direction of the pad electrode layer 473.

[0183] (Embodiment 6) A light-emitting module according to embodiment 6 will be described. The light-emitting module according to this embodiment differs from light-emitting module 5 according to embodiment 1 mainly in the configurations of the base electrode and the back surface metal layer. The light-emitting module according to this embodiment will be described below with reference to FIG. 29, focusing on the differences from embodiment 1. FIG. 29 is a schematic cross-sectional view showing the overall configuration of a light-emitting module 505 according to this embodiment.

[0184] As shown in FIG. 29, a light emitting module 505 according to this embodiment includes a light emitting device 501, a heat sink 90, and a second bonding layer 80.

[0185] The light-emitting device 501 according to this embodiment includes a semiconductor laser element 10 , a first electrode 20 , a base 570 , a first bonding layer 530 , a relay electrode 571 , and a back surface metal layer 576 .

[0186] The base 570 is a base to which the semiconductor laser device 10 is bonded. The base 570 has a first main surface 570a to which the semiconductor laser device 10 is bonded and a second main surface 570b located on the back side of the first main surface 570a. In this embodiment, the base 570 is made of an electrically insulating material. More specifically, the base 570 is an AlN ceramic substrate with a thickness of 350 μm.

[0187] The first bonding layer 530 includes a second electrode 40 , a metal film 50 , and a base electrode 560 , which are arranged in this order from the semiconductor laser device 10 toward the base 570 .

[0188] The base electrode 560 is a conductive member disposed between the metal film 50 and the base 570. The base electrode 560 is disposed on a first main surface 570a of the base 570. In the present embodiment, the base electrode 560 has a base bonding layer 562a, a base adhesion layer 561b, a base bonding layer 562b, and a base adhesion layer 561a, which are disposed in this order from the semiconductor laser element 10 toward the base 570.

[0189] The base adhesion layer 561a is a conductive layer disposed between the base 570 and the base bonding layer 562b. In this embodiment, the base adhesion layer 561a contacts the first main surface 570a of the base 570. The base adhesion layer 561a may have the function of increasing the adhesion between the first main surface 570a of the base 570 and the base bonding layer 562b. The base adhesion layer 561a may be, for example, a single layer film made of Ti, Cr, or Ni. In this embodiment, the base adhesion layer 561a is a Ti film with a thickness of 0.1 μm.

[0190] The base bonding layer 562b is disposed between the metal film 50 and the base 570 and is a conductive layer composed of a single metal element. In this embodiment, the base bonding layer 562b is disposed between the base adhesion layer 561a and the base adhesion layer 561b. The base bonding layer 562b may be selected from Au, Ag, Cu, or Al. The thickness of the base bonding layer 562b may be, for example, 10 μm or more, 30 μm or more, or 50 μm or more. Increasing the thickness of the base bonding layer 562b in this manner reduces the electrical resistance of the base bonding layer 562b in the direction along the first main surface 570a of the base 570. In this embodiment, the base bonding layer 562b is a Cu film with a thickness of 75 μm. Increasing the thickness of the base bonding layer 562b in this manner may result in significant warping of the base 570 due to the difference in thermal expansion coefficients between the base bonding layer 562b and the base 570. In order to reduce such warpage, a film having the same configuration as the base bonding layer 562b may be formed on the second main surface 570b of the base 570, or a back surface metal layer 576 having the same layer configuration as the base electrode 560 may be disposed on the second main surface 570b of the base 570. The base bonding layer 562b may be formed by plating, for example, an electrolytic plating process.

[0191] The base adhesion layer 561b is a conductive layer disposed between the base 570 and the base bonding layer 562a. In this embodiment, the base adhesion layer 561b is disposed between the base bonding layer 562a and the base bonding layer 562b. The base adhesion layer 561b may have the function of increasing the adhesion between the base bonding layer 562a and the base bonding layer 562b. The base adhesion layer 561b may be a single layer film made of, for example, Ti, Cr, or Ni. In this embodiment, the base adhesion layer 561b is a Ni film having a thickness of 1 μm.

[0192] The base bonding layer 562a is disposed between the metal film 50 and the base 570 and is a conductive layer made of a single metal element. In this embodiment, the base bonding layer 562a is disposed between the base adhesion layer 561b and the metal film 50. The base bonding layer 562a may be selected from Au, Ag, Cu, or Al. In this embodiment, the base bonding layer 562a is an Au film with a thickness of 1 μm.

[0193] The relay electrode 571 is a conductive member disposed on the base 570. The relay electrode 571 is electrically insulated from the base electrode 560. In the present embodiment, the relay electrode 571 is disposed on the first main surface 570a of the base 570. The relay electrode 571 may be used to relay a power supply path for supplying power to the first electrode 20. For example, as shown in FIG. 29 , a wire W connected to a power source (not shown) and a wire W connected to the first electrode 20 may be bonded to the relay electrode 571.

[0194] The relay electrode 571 has a base adhesion layer 572a arranged on the first main surface 570a of the base 570, a pad electrode layer 573b arranged above the base adhesion layer 572a, a base adhesion layer 572b arranged above the pad electrode layer 573b, and a pad electrode layer 573a arranged above the base adhesion layer 572b. The base adhesion layer 572a is arranged between the base 570 and the pad electrode layer 573b. The pad electrode layer 573b is arranged between the base adhesion layer 572a and the base adhesion layer 572b. The base adhesion layer 572b is arranged between the pad electrode layer 573b and the pad electrode layer 573a. The pad electrode layer 573a is arranged above the base adhesion layer 572b.

[0195] The relay electrode 571 may have the same layer structure as the base electrode 560. Furthermore, the relay electrode 571 may be formed simultaneously with the base electrode 560 in the same process.

[0196] The back surface metal layer 576 is a metal layer disposed on the second main surface 570b of the base 570. The back surface metal layer 576 may have the function of increasing the adhesion between the base 570 and the heat sink 90. ​​In the present embodiment, the back surface metal layer 576 has a back surface adhesion layer 577a, a back surface bonding layer 578b, a back surface adhesion layer 577b, and a back surface bonding layer 578a. As described above, in order to reduce warping of the base 570, the back surface metal layer 576 may have the same layer configuration as the base electrode 560.

[0197] The back surface adhesion layer 577a is a metal layer disposed between the base 570 and the back surface bonding layer 578b. In this embodiment, the back surface adhesion layer 577a contacts the second main surface 570b of the base 570. The back surface adhesion layer 577a may have a function of increasing adhesion between the second main surface 570b of the base 570 and the back surface bonding layer 578b. The back surface adhesion layer 577a may be a single layer film made of, for example, Ti, Cr, or Ni. In this embodiment, the back surface adhesion layer 577a is a Ti film having a thickness of 0.1 μm.

[0198] The back surface bonding layer 578b is a conductive layer disposed between the base 570 and the second bonding layer 80. In the present embodiment, the back surface bonding layer 578b is disposed between the back surface adhesive layer 577a and the back surface adhesive layer 577b. The back surface bonding layer 578b is a layer made of a single metal element. The back surface bonding layer 578b may be a single layer film made of Au, Ag, Cu, or Al. In the present embodiment, the back surface bonding layer 578b is a single layer film made of Cu. In the present embodiment, the back surface bonding layer 578b is a Cu film with a thickness of 75 μm. The back surface bonding layer 578b may be formed by plating, for example.

[0199] The back surface adhesion layer 577b is a metal layer disposed between the base 570 and the back surface bonding layer 578a. In this embodiment, the back surface adhesion layer 577b is disposed between the back surface bonding layer 578b and the back surface bonding layer 578a. The back surface adhesion layer 577b may have a function of increasing the adhesion between the back surface bonding layer 578b and the back surface bonding layer 578a. The back surface adhesion layer 577b may be a single layer film made of, for example, Ti, Cr, or Ni. In this embodiment, the back surface adhesion layer 577b is a Ni film having a thickness of 1 μm.

[0200] The back surface bonding layer 578a is a conductive layer disposed between the base 570 and the second bonding layer 80. In the present embodiment, the back surface bonding layer 578a is disposed between the back surface adhesive layer 577b and the second bonding layer 80. The back surface bonding layer 578a is a layer made of a single metal element. The back surface bonding layer 578a may be a single layer film made of Au, Ag, Cu, or Al. In the present embodiment, the back surface bonding layer 578a is a single layer film made of Au. In the present embodiment, the back surface bonding layer 578a is an Au film with a thickness of 1 μm.

[0201] The light-emitting module 505 having the above configuration also achieves the same effects as the light-emitting module 5 according to embodiment 1. Furthermore, in this embodiment, the thick base bonding layer 562b is made of Au, Ag, Cu, or Al, which has high thermal conductivity, and therefore the heat dissipation properties of the base electrode 560 in the direction along the first main surface 570a of the base 570 can be improved. Furthermore, the electrical resistance in the direction along the first main surface 570a of the base electrode 560 can be reduced.

[0202] Seventh Embodiment A light-emitting module according to a seventh embodiment will be described. The light-emitting module according to this embodiment differs from the light-emitting module 5 according to the first embodiment mainly in that it includes a functional element. The light-emitting module according to this embodiment will be described below with reference to FIG. 30, focusing on the differences from the light-emitting module 5 according to the first embodiment. FIG. 30 is a schematic cross-sectional view showing the overall configuration of a light-emitting module 605 according to this embodiment.

[0203] As shown in FIG. 30, a light emitting module 605 according to this embodiment includes a light emitting device 601, a second bonding layer 80, and a heat sink 90.

[0204] The light-emitting device 601 includes a semiconductor laser element 10 , a first electrode 20 , a base 70 , a first bonding layer 30 , a Zener diode 699 , a functional element bonding layer 651 , and a back surface metal layer 76 .

[0205] The Zener diode 699 is an example of a functional element having a different function from the semiconductor laser element 10. The Zener diode 699 is connected in anti-parallel to the semiconductor laser element 10, for example. That is, a cathode electrode 699a of the Zener diode 699 is connected to the anode of the semiconductor laser element 10, and an anode electrode 699b of the Zener diode 699 is connected to the cathode of the semiconductor laser element 10. In this case, a Zener diode 699 having a breakdown voltage slightly higher than the operating voltage of the semiconductor laser element 10 is used. As a result, when a voltage less than the breakdown voltage of the Zener diode 699 is applied to the semiconductor laser element 10, a current flows only through the semiconductor laser element 10. On the other hand, when a voltage equal to or greater than the breakdown voltage of the Zener diode 699 is applied to the semiconductor laser element 10 due to a surge or the like, the Zener diode 699 has a lower resistance than the semiconductor laser element 10, and therefore a current flows only through the Zener diode 699. Furthermore, when a reverse voltage is applied to the semiconductor laser element 10, a forward voltage is applied to the Zener diode 699, and therefore, a current flows only through the Zener diode 699. As described above, the Zener diode 699 has the function of protecting the semiconductor laser element 10 when an abnormal voltage is applied to the semiconductor laser element 10.

[0206] In the present embodiment, the Zener diode 699 is disposed on the first main surface 70a of the base 70. A cathode electrode 699a of the Zener diode 699 is bonded to the base electrode 60 by the functional element bonding layer 651. In this manner, the Zener diode 699 is disposed on the first main surface 70a of the base 70 via the base electrode 60 and the functional element bonding layer 651. Note that, because precise alignment of the Zener diode 699 with respect to the semiconductor laser element 10 is not required, the Zener diode 699 may be bonded to the semiconductor laser element 10 at the same time by the functional element bonding layer 651 having a configuration similar to that of the metal film 50.

[0207] The functional element bonding layer 651 is a member that bonds the base body 70 and the functional element. In this embodiment, the functional element bonding layer 651 has the same configuration as the metal film 50.

[0208] The light emitting module 605 having the above configuration also achieves the same effects as the light emitting module 5 according to embodiment 1. Furthermore, in this embodiment, the light emitting module 605 includes a functional element, and therefore functions can be added to the light emitting module 5. The light emitting module 605 according to this embodiment includes the Zener diode 699 as the functional element, and therefore can protect the semiconductor laser element 10 when an abnormal voltage is applied to the semiconductor laser element 10.

[0209] (Other Embodiments) While the present disclosure has been described above based on the embodiments and modifications, the present disclosure is not limited to these embodiments and modifications. As long as they do not deviate from the gist of the present disclosure, various modifications that a person skilled in the art could conceive of to the embodiments and other forms constructed by combining some of the components of the embodiments and modifications are also included in the scope of the present disclosure.

[0210] For example, in each of the first embodiments, the paste 50P is patterned when it is applied, but it may be patterned after it is applied.

[0211] Although the fourth and fifth embodiments illustrate examples in which wire W is used as the power supply conductor, the configuration of the power supply conductor is not limited to this. For example, a plate-shaped, rod-shaped, or sheet-shaped conductor may be used as the power supply conductor, or a conductive film disposed on a wiring board may be used.

[0212] Furthermore, it is also possible to combine the fourth embodiment with the fifth embodiment. That is, a power supply conductor may be directly bonded to the extending portion of the metal film, and another power supply conductor may be directly bonded to the base bonding layer.

[0213] Furthermore, the above-described embodiments can be modified, substituted, added, omitted, and the like in various ways within the scope of the claims or their equivalents.

[0214] The light-emitting device according to the present disclosure is particularly useful as a high-brightness, high-power laser light source, such as a laser light source for processing, a laser light source for displays, or a laser light source for medical use.

[0215] 1, 301, 401, 501, 601 Light-emitting device 5, 106, 206, 305, 405, 505, 506, 605 Light-emitting module 10 Semiconductor laser element 10S Semiconductor laminate 10Sa Opposing surface 10Sb Back surface 10Sc Side surface 10T Laminate recess 11 Substrate 12 First semiconductor layer 13 Active layer 14 Second semiconductor layer 14R Ridge stripe 14T Groove 14W Raised portion 15 Insulating film 20 First electrode 21 Ohmic electrode layer 22 Pad electrode layer 30, 530 First bonding layer 40 Second electrode 41 Ohmic electrode layer 42 Adhesion layer 43 Element bonding layer 50, 350 Metal film 50a High filling portion 50b Low filling portion 50e, 350e Extension portion 50P Paste 60, 460, 560 Base electrode 61, 72, 561a, 561b, 572a, 572b Base adhesion layer 62, 462, 562a, 562b Base bonding layer 70, 570 Base 70a, 570a First main surface 70b, 570b Second main surface 71, 471, 571 Relay electrode 73, 473, 573a, 573b Pad electrode layer 76, 576 Back surface metal layer 77, 577a, 577b Back surface adhesion layer 78, 578a, 578b Back surface bonding layer 80 Second bonding layer 90 Heat sink 112, 290, 590 Module substrate 113, 213, 513 Frame 114, 214, 514 Lid 120 FAST axis collimator lens 121 SLOW axis collimator lens 122, 522 Reflecting mirror 123 Condenser lens 124 Optical fiber 140, 240, 540 Current input terminal 190 Multi-stage base 191, 291 Laser mounting surface 192 Optical element mounting surface 215, 515 Light-transmitting window 581 Optical element bonding layer 651 Functional element bonding layer 699 Zener diode 699a Cathode electrode 699b Anode electrode W Wire

Claims

1. a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; the metal film is made of Au, Ag, Cu, or Al; a total thickness of the element bonding layer, the metal film, and the base bonding layer is 80% or more of a thickness of the first bonding layer; The metal film is porous. Light-emitting device.

2. a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; the metal film is made of Au, Ag, Cu, or Al; a total thickness of the layers of the first bonding layer made of a single metal element selected from Au, Ag, Cu, and Al is 80% or more of a thickness of the first bonding layer; The metal film is porous. Light-emitting device.

3. a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; the metal film is made of Au, Ag, Cu, or Al; a total thickness of the element bonding layer, the metal film, and the base bonding layer is 80% or more of a thickness of the first bonding layer; the semiconductor laser element has a ridge stripe extending along a resonance direction of the semiconductor laser element, A part of the metal film is disposed at a position facing a side surface of the ridge stripe extending along the resonance direction. Light-emitting device.

4. a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; the metal film is made of Au, Ag, Cu, or Al; a total thickness of the layers of the first bonding layer made of a single metal element selected from Au, Ag, Cu, and Al is 80% or more of a thickness of the first bonding layer; the semiconductor laser element has a ridge stripe extending along a resonance direction of the semiconductor laser element, A part of the metal film is disposed at a position facing a side surface of the ridge stripe extending along the resonance direction. Light-emitting device.

5. a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; the metal film is made of Au, Ag, Cu, or Al; a total thickness of the element bonding layer, the metal film, and the base bonding layer is 80% or more of a thickness of the first bonding layer; The metal film has an extension portion that extends outward from a side surface of the semiconductor laser element in a cross section perpendicular to the resonance direction of the semiconductor laser element. Light-emitting device.

6. a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; the metal film is made of Au, Ag, Cu, or Al; a total thickness of the layers of the first bonding layer made of a single metal element selected from Au, Ag, Cu, and Al is 80% or more of a thickness of the first bonding layer; The metal film has an extension portion that extends outward from a side surface of the semiconductor laser element in a cross section perpendicular to the resonance direction of the semiconductor laser element. Light-emitting device.

7. the element bonding layer is made of Au, Ag, Cu, or Al; The substrate bonding layer is made of Au, Ag, Cu, or Al. The light-emitting device according to any one of claims 1 to 6.

8. The semiconductor laser element is a GaN-based semiconductor laser element. The light-emitting device according to any one of claims 1 to 6.

9. the semiconductor laser element has a ridge stripe extending along a resonance direction of the semiconductor laser element, The width of the ridge stripe is 100 μm or less. The light-emitting device according to any one of claims 1 to 6.

10. The first bonding layer is an ohmic electrode layer in contact with the semiconductor laser element; The device further includes an adhesion layer disposed between the ohmic electrode layer and the device junction layer. The light-emitting device according to any one of claims 1 to 6.

11. The substrate is made of an electrically insulating material. The light-emitting device according to any one of claims 1 to 6.

12. the metal film is made of Au, The thickness of the metal film is 10 μm or less.

3. A light-emitting device according to claim 1 or 2.

13. The porosity of the metal film in terms of area ratio is less than 30%. The light-emitting device according to any one of claims 1 to 6.

14. The element bonding layer, the metal film, and the base bonding layer are made of the same metal element. The light-emitting device according to any one of claims 1 to 6.

15. The adhesive layer is made of Ti, Cr, or Ni.

11. The light emitting device of claim 10.

16. The semiconductor laser element is A substrate; a semiconductor laminate stacked on the substrate and including a pn junction; an insulating film covering a part of the semiconductor laminate; the semiconductor laminate has a back surface on the back side of an opposing surface opposing the substrate, and a side surface connected to the opposing surface and extending along a resonance direction of the semiconductor laser element, the semiconductor stack has a stack recess located between the back surface and the side surface and recessed relative to the back surface and the side surface, a depth of the stack recess from the back surface toward the substrate is greater than a depth from the back surface to the pn junction; The insulating film covers the laminated body recess. The light-emitting device according to any one of claims 1 to 6.

17. The maximum height of the extension from the base is greater than the minimum distance from the base to the device bonding layer.

7. A light-emitting device according to claim 5 or 6.

18. The surface of the extension has a convex shape.

7. A light-emitting device according to claim 5 or 6.

19. A light-emitting device according to any one of claims 1 to 6; a heat sink to which the base of the light emitting device is bonded; a second bonding layer that bonds the base and the heat sink together, The melting point of the second bonding layer is lower than the melting point of the first bonding layer. Light-emitting module.

20. A light emitting module comprising a light emitting device, The light emitting device comprises: a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; the metal film is made of Au, Ag, Cu, or Al; a total thickness of the element bonding layer, the metal film, and the base bonding layer is 80% or more of a thickness of the first bonding layer; The light emitting module includes: a heat sink to which the base of the light emitting device is bonded; a second bonding layer that bonds the base and the heat sink, the melting point of the second bonding layer is lower than the melting point of the first bonding layer; the light-emitting module has a power supply conductor for supplying power to the semiconductor laser element; the metal film has an extension portion that extends outward from a side surface of the semiconductor laser element in a cross section perpendicular to a resonance direction of the semiconductor laser element, The power supply conductor is directly joined to the extension. Light-emitting module.

21. A light emitting module comprising a light emitting device, The light emitting device comprises: a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; the metal film is made of Au, Ag, Cu, or Al; a total thickness of the layers of the first bonding layer made of a single metal element selected from Au, Ag, Cu, and Al is 80% or more of a thickness of the first bonding layer; The light emitting module includes: a heat sink to which the base of the light emitting device is bonded; a second bonding layer that bonds the base and the heat sink, the melting point of the second bonding layer is lower than the melting point of the first bonding layer; the light-emitting module has a power supply conductor for supplying power to the semiconductor laser element; the metal film has an extension portion that extends outward from a side surface of the semiconductor laser element in a cross section perpendicular to a resonance direction of the semiconductor laser element, The power supply conductor is directly joined to the extension. Light-emitting module.

22. A light emitting module comprising a light emitting device, The light emitting device comprises: a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; the metal film is made of Au, Ag, Cu, or Al; a total thickness of the element bonding layer, the metal film, and the base bonding layer is 80% or more of a thickness of the first bonding layer; The light emitting module includes: a heat sink to which the base of the light emitting device is bonded; a second bonding layer that bonds the base and the heat sink, the melting point of the second bonding layer is lower than the melting point of the first bonding layer; the light-emitting module has a power supply conductor for supplying power to the semiconductor laser element; the power supply conductor is directly bonded to the base bonding layer; The thickness of the substrate bonding layer is 0.3 μm or more. Light-emitting module.

23. A light emitting module comprising a light emitting device, The light emitting device comprises: a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; the metal film is made of Au, Ag, Cu, or Al; a total thickness of the layers of the first bonding layer made of a single metal element selected from Au, Ag, Cu, and Al is 80% or more of a thickness of the first bonding layer; The light emitting module includes: a heat sink to which the base of the light emitting device is bonded; a second bonding layer that bonds the base and the heat sink, the melting point of the second bonding layer is lower than the melting point of the first bonding layer; the light-emitting module has a power supply conductor for supplying power to the semiconductor laser element; the power supply conductor is directly bonded to the base bonding layer; The thickness of the substrate bonding layer is 0.3 μm or more. Light-emitting module.

24. The light emitting device is hermetically sealed.

20. The light emitting module according to claim 19.

25. The second bonding layer is made of AuSn or SnAgCu.

20. The light emitting module according to claim 19.

26. 1. A method for manufacturing a light emitting device, comprising: The light emitting device comprises: a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; The method for manufacturing the light-emitting device includes: an element bonding layer forming step of forming the element bonding layer on the semiconductor laser element; a base bonding layer forming step of forming the base bonding layer on the base; a coating step of coating a paste in which metal fine particles are dispersed in a solvent onto the base bonding layer; a placement step of placing the element bonding layer on the paste; a sintering step of heating the paste to sinter it, thereby converting the paste into the metal film. A method for manufacturing a light-emitting device.

27. Between the applying step and the disposing step, a removing step of removing the solvent by heating the paste is included.

27. A method for manufacturing the light emitting device of claim 26.

28. The viscosity of the paste is 10 Pa·s or more. A method for manufacturing a light-emitting device according to claim 26 or 27.

29. A method for manufacturing a light-emitting device, comprising: The light emitting device comprises: a substrate; a semiconductor laser element bonded to the base; a first bonding layer that bonds the base and the semiconductor laser element, The first bonding layer is an element junction layer made of a single metal element; a metal film of a sintered body made of a single metal element, the metal film being disposed between the element bonding layer and the base; a substrate bonding layer disposed between the metal film and the substrate and made of a single metal element; The method for manufacturing the light-emitting device includes: A sintering step is included in which the metal fine particles are heated to form the sintered body. A method for manufacturing a light-emitting device.

30. A method for manufacturing a light emitting module, comprising: A method for manufacturing a light-emitting device according to any one of claims 26, 27 and 29, The light emitting module includes: the light emitting device; a heat sink to which the base of the light-emitting device is bonded; The method for manufacturing the light emitting module includes: a second bonding layer disposing step of disposing a second bonding layer on the heat sink; a base placement step of placing the base on the second bonding layer; and a bonding step of bonding the base to the heat sink by heating the second bonding layer. A method for manufacturing a light-emitting module.

31. The heating temperature in the sintering step is lower than the heating temperature in the joining step. A method for manufacturing the light-emitting module according to claim 30.