Package for mounting optical element, and light-emitting device

Abstract

This package for mounting an optical element has a body provided with an insulating frame body, a base body which is positioned to close a lower end of the frame body and has a thermal conductivity higher than that of the frame body, and a protruding part that protrudes from an upper surface of the base body relative to a recessed part surrounded by the frame body and the base body. The frame body has, on the upper surface side opposite to the lower end, a mounting surface to which a lid body having a translucent flat plate can be joined. The protruding part has a mounting surface that intersects the upper surface and on which an edge-emitting optical element can be mounted. The protruding part may be structured integrally with at least a part of a heat transfer body, and the integral structure portion may penetrate the heat transfer body.

Description

Package for mounting optical element and light emitting device

[0001] The present disclosure relates to a package for mounting an optical element and a light emitting device.

[0002] There is a package that houses a laser light source and emits light emitted by the laser light source. International Publication No. 2020 / 175303 discloses a technology in which light emitted from the light source in a direction along the bottom surface of the package is reflected upward by a mirror and emitted.

[0003] One aspect of the present disclosure is an optical element mounting package comprising: [1] an insulating frame body; a heat transfer body positioned to cover a first end of the frame body and having a higher thermal conductivity than the frame body; and a protrusion protruding from a first surface of the heat transfer body into a space surrounded by the frame body and the heat transfer body, the frame body having a first mounting surface on a second end side opposite the first end to which a lid body having a light-transmitting portion can be joined, the protrusion intersecting the first surface and having a second mounting surface on which an edge-emitting optical element can be mounted. [2] The optical element mounting package of [1], wherein the protrusion is integral with at least a portion of the heat transfer body, and the at least a portion penetrates the heat transfer body. [3] The optical element mounting package of [1] or [2], wherein the second mounting surface intersects with the first surface at an angle between 45 degrees and 90 degrees. [4] The optical element mounting package of any one of [1] to [3], wherein a plurality of optical elements can be mounted on the second mounting surface. [5] The optical element mounting package according to any one of [1] to [4], wherein the frame has a wiring conductor connecting the optical element to the outside. [6] The optical element mounting package according to [5], wherein the frame has exposed electrodes electrically connected to the wiring conductor, and the surface including the electrodes is oriented along the second mounting surface. [7] The optical element mounting package according to [6], wherein the second mounting surface and the electrodes are simultaneously visible when viewed from the side directly facing the second mounting surface, and the height from the first surface of the frame on the side opposite the electrode-containing side of the protrusion is lower than the height from the first surface of the protrusion. [8] The optical element mounting package according to any one of [1] to [7], wherein the heat conductor is aluminum, copper, or an alloy containing at least one of them. [9] The optical element mounting package according to any one of [1] to [8], wherein the frame is ceramic.

[10] The optical element mounting package according to [9], wherein the ceramic is alumina.

[11] The package for mounting an optical element according to any one of [1] to [9], which has a light-transmitting portion through which light emitted from the optical element passes and is provided with a lid body that can be joined to the first mounting surface.

[12] The package for mounting an optical element according to

[11] , wherein the light-transmitting portion has a lens structure.

[13] A light emitting device comprising: an optical element mounting package according to any one of [1] to

[10] ; an optical element mounted on the second mounting surface; and a lid body having a translucent portion through which light emitted by the optical element passes and bondable to the first mounting surface, wherein the optical element is mounted on the second mounting surface in a direction such that light is emitted to the outside of the optical element mounting package through the translucent portion.

[0004] FIG. 1 is an overall perspective view of a light emitting device of a first embodiment. FIG. 2 is an exploded perspective view of the main body and lid of the light emitting device. FIG. 3 is a cross-sectional view of the main body. FIG. 4 is a perspective view of the main body of a second embodiment. FIG. 5 is a cross-sectional view of the main body of the second embodiment. FIG. 6 is a perspective view of a light emitting device of a third embodiment. FIG. 7 is an exploded perspective view of the main body and lid of the light emitting device of the third embodiment separated. FIG. 8 is a perspective view of a light emitting device of a fourth embodiment. FIG. 9 is a perspective view of a light emitting device of a fifth embodiment. FIG. 10 is a perspective view of the main body of a sixth embodiment. FIG. 11 is a cross-sectional view of the main body of the sixth embodiment. FIG. 12 is a cross-sectional view of the main body of a seventh embodiment. FIG. 13 is a diagram showing an example in which a plurality of light emitting devices are arranged on a circuit board.

[0005] Hereinafter, embodiments will be described with reference to the drawings. [First Embodiment] Fig. 1 is an overall perspective view of a light emitting device 1 according to a first embodiment. Fig. 2 is an exploded perspective view of a main body 10 and a lid 30 of the light emitting device 1. The light emitting device 1 includes the main body 10, the lid 30, an optical element 50, and the like.

[0006] The main body 10 is a housing of the optical element mounting package that houses the optical element 50 inside. The lid 30 seals the optical element 50 inside the main body 10. The lid 30 has a light-transmitting flat plate 32 located on the upper surface of a frame 31, and light can be emitted from the optical element 50 inside the main body 10 through the flat plate 32. The lid 30 may be included in the optical element mounting package. Alternatively, the lid 30 may be distributed independently of the optical element mounting package that includes only the main body 10.

[0007] The main body 10 includes a frame 11 and a base 12. The frame 11 has an annular shape with open top and bottom. The base 12 is located inside the frame 11 and closes the lower end, which is the first end, of the frame 11. The base 12 is a heat conductor and has a higher thermal conductivity than the frame 11. For example, the base 12 may be a metal member such as copper or aluminum, or an alloy containing at least one of these. Alternatively, the base 12 may be a ceramic material. A single-crystalline inorganic material may also be suitably used for the base 12. Furthermore, the base 12 may be a composite of an inorganic material and a metal and have a high thermal conductivity. In other words, the base 12 may or may not be electrically conductive.

[0008] The frame body 11 has insulating properties. The frame body 11 may be made of, for example, alumina, aluminum nitride, silicon nitride, zirconia, or resin. Therefore, when ceramic, particularly alumina, is used as the main component of the frame body 11, the airtightness of the frame body 11 is higher than when a material other than ceramic is used. Furthermore, when ceramic is used as the main component of the frame body 11, the difference in thermal expansion coefficient between the frame body 11 and the base body 12 can be made smaller than when a material other than ceramic is used. The frame body 11 may have a structure in which multiple layers are stacked. Via conductors 118 that penetrate the frame body 11 in the thickness direction are located in each layer and connect the layers to each other.

[0009] The frame 11 has an annular protrusion 111 extending inward from its inner surface. The protrusion 111 is integral with and made of the same material as the frame 11. The peripheral edge of the upper surface 12a of the base 12 is joined to the lower surface side of the protrusion 111.

[0010] A recess 10a is located, which is a space surrounded by the inner surface of the frame 11 and the upper surface 12a of the base 12. In one embodiment, the upper surface 12a is the first surface. A protrusion 121 protrudes from the upper surface 12a of the base 12 toward the recess 10a. The protrusion 121 may be, for example, rectangular prism-shaped. The height of the protrusion 121 from the upper surface 12a is greater than the height from the upper surface 12a to the upper end of the frame 11. The protrusion 121 is integral with the base 12 and is made of the same material. The periphery of the protrusion 121 is stepped by the upper surface and the protrusion 111.

[0011] One of the side surfaces of the protrusion 121 that intersects with the top surface 12a (here, perpendicular to the top surface 12a) is a mounting surface 121a, which is a second mounting surface for the optical element 50. The mounting surface 121a is the surface of the protrusion 121 facing the center of the recess 10a. One or more optical elements 50 can be adhered and mounted on the mounting surface 121a. For example, three optical elements 50 may be positioned on the mounting surface 121a. The optical element 50 is an edge-emitting laser diode (LD). The optical element 50 is in contact with the protrusion 121 along its long side. This allows the optical element 50 to emit light outward through the lid 30 during operation, and the generated heat is quickly transferred to the base 12 via the protrusion 121, which serves as a heat conductor.

[0012] Here, the optical element 50 is positioned so as to emit light perpendicularly upward with respect to the upper surface 12a, i.e., in the direction opposite to the upper surface 12a, but this is not limiting. The optical element 50 may also emit light in an oblique direction with respect to the upper surface 12a.

[0013] The three optical elements 50 may be connected in series, with both ends connected to the electrodes 115a, 115b. Bonding wires are used to connect the optical elements 50 together and between the optical elements 50 and the electrodes 115a, 115b. For example, four sets of bonding wires may be connected in parallel to connect the electrodes 115a, the optical elements 50, and the electrodes 115b. By connecting with multiple sets of bonding wires, even if one set is broken, the other sets of bonding wires can still cause the optical elements 50 to emit light.

[0014] The electrodes 115a, 115b may be exposed on a side surface of the support base 112 located on the protrusion 111. The support base 112 may be located between the surface of the protrusion 121 opposite the mounting surface 121a and the inner surface of the frame body 11. The support base 112 may be separate from the frame body 11. That is, the support base 112 may be bonded to the frame body 11. The bonding may be performed using a sintering paste or the like. The support base 112 has a wiring structure therein that is connected to the electrodes 115a, 115b, respectively. The portions of the support base 112 other than the wiring structure are made of an insulating material and may be the same as those of the frame body 11, for example.

[0015] In this case, the electrodes 115a and 115b are positioned so that they can be seen simultaneously with the mounting surface 121a and the optical element 50 in a plan view from the side directly opposite the mounting surface 121a. In particular, the surface including the electrodes 115a and 115b may be oriented along the mounting surface 121a. "Along" means that the surfaces are parallel to each other or within a range slightly deviated from the parallel direction. Specifically, the angle between the two surfaces is ±30 degrees or less, more preferably ±20 degrees or less, and even more preferably ±10 degrees or less. The wiring structure is connected to the wiring structure of the frame body 11 as described below, and is electrically connected to an external electrode located on the underside of the frame body 11.

[0016] The top surface 11a, which is the second end of the frame 11, serves as a first mounting surface to which the lid 30 can be bonded. The separate main body 10 and lid 30 are bonded after the optical element 50 is mounted on the mounting surface 121a and the optical element 50 is connected to the electrodes 115a, 115b by bonding wires W. This seals the recess 10a containing the optical element 50. At this time, dry air or an inert gas may be filled inside the recess 10a.

[0017] As described above, the lid 30 includes a frame 31 and a flat plate 32. The frame 31 may be made of the same material as the frame 11 of the main body 10, i.e., alumina, for example. The outer peripheral shape of the frame 31 is the same as that of the frame 11. The inner peripheral shape of the frame 31 does not have to be the same as that of the frame 11. The height of the frame 31 is determined so that the widths of the upper surface of the protrusion 121 and the light-emitting end of the optical element 50 do not come into contact with the lower surface of the flat plate 32 when the recess 10a is sealed with the lid 30, but are small enough to prevent these from coming into contact. As a result, the light emitted by the optical element 50 has an optical path length that corresponds to the thickness of the lid 30. The short optical path length, especially the optical path length inside the recess 10a, reduces the diffusion of the emitted light. Accordingly, interference between the emitted beams is less likely to occur than in the case where the protrusion 121 is not present and the optical path length inside the recess 10a of the light emitted from near the top surface 12a is longer than the optical path length in this embodiment. Therefore, the intervals between the multiple optical elements 50 mounted on the mounting surface 121a can be narrowed. The planar size of the optical element mounting package can also be reduced depending on the intervals between the optical elements 50.

[0018] The flat plate 32 is an airtight, light-transmitting member included in the light-transmitting portion. The flat plate 32 may be made of, for example, borosilicate glass or sapphire glass. The surface of the flat plate 32 may be anti-reflective coated (AR coated). The flat plate 32 may be joined to the frame 31 using, for example, frit glass.

[0019] The main body 10 and the lid 30 can be joined via a joining member 40. The joining member 40 may be made of, for example, gold tin. For gold tin, for example, an annular preform having a width narrower than each of the frame bodies 11, 31 can be used as a seal ring.

[0020] Alternatively, frit glass or the like may be used for bonding. In this case, the frit glass has a lower melting point than the frit glass of the lid body 30 so that the bonding surface between the frame body 31 and the flat plate 32 in the lid body 30 does not remelt during bonding. The low-melting-point frit glass may contain a mixture of metals such as tellurium, bismuth, and vanadium.

[0021] 3 is a cross-sectional view of the main body 10 taken along the line AA. In this cross-sectional view, which includes the electrode 115a, a wiring member is connected between the electrode 115a and an external connection electrode 117 located on the bottom surface of the frame body 11.

[0022] Specifically, a plurality of via conductors 118 are stacked within the frame body 11 and connected to connection wiring 119 located on the upper surface of the protrusion 111. The electrode 115a is connected to a wiring member 116, which is a wiring conductor extending inside the support base 112. The wiring member 116 is exposed from the lower end of the support base 112 and connected to the connection wiring 119. In other words, the wiring conductor including the wiring member 116, the external connection electrode 117, the via conductor 118, and the connection wiring 119 connects the optical element 50, which is connected to the electrode 115a by the bonding wire W, to the outside.

[0023] As described above, the heat dissipation path from the optical element 50 is mainly the base 12, while the electrical path to the optical element 50 is the frame 11. In other words, the heat dissipation path and the electrical path are separated. As a result, the electrical path is less likely to experience large temperature changes, and accordingly, changes in the resistance value of the electrical path are reduced. On the other hand, as described above, the heat dissipation path is wide and has high thermal conductivity. Therefore, heat is quickly dissipated from the optical element 50.

[0024] Second Embodiment Fig. 4A is a perspective view showing the main body 101 of the second embodiment. Fig. 4B is a cross-sectional view taken along the line AA. The main body 101 may not have the support base 112. The main body 101 may have pillars 115c and 115d, which are independently standing upright electrode columns, instead of the electrodes 115a and 115b. The contact portions of the pillars 115c and 115d with the protrusion 111 may be thicker for stability. The shapes of the pillars 115c and 115d are arbitrary. However, the bonding portion of the bonding wire W being partially flat and substantially parallel to the mounting surface 121a facilitates wire bonding.

[0025] The pillars 115c and 115d may be fixed in a state in which they are electrically connected to the connection wiring 119 using a brazing material such as silver solder, for example.

[0026] Third Embodiment Fig. 5A is a perspective view showing a light emitting device 1b according to a third embodiment, and Fig. 5B is an exploded perspective view showing a cover 302 and a main body 102 of the light emitting device 1b separated from each other.

[0027] This light-emitting device 1b may have a housing 312 with a cap-shaped lid 302 and a flat plate 322 that seals an opening on the top surface of the housing 312. The flat plate 322 may be bonded to the outside of the opening as shown, or may be bonded to the inside of the opening. Alternatively, the flat plate 322 may be fitted along the edge of the opening. The size of the opening may be within a range that allows the emitted light from the optical element 50 to be emitted without being obstructed. The housing 312 having such a three-dimensional shape may be obtained, for example, by molding a metal member using drawing.

[0028] The main body 102 may be identical to the main body 10 of the first embodiment, except that an annular metal frame material 13 is located on the upper end surface of the frame body 11. The same components are denoted by the same reference numerals, and detailed description thereof will be omitted. The metal frame material 13 may be, for example, Kovar (registered trademark), which has low electrical resistance. The metal frame material 13 may overlap the position where the lower end of the housing 312 contacts the main body 102 in a plan view, i.e., the lower end of the housing 312 and the metal frame material 13 may be joined. Because both the housing 312 and the metal frame material 13 are low-resistance metals, they may be joined by seam welding.

[0029] [Fourth and Fifth Embodiments] Fig. 6A is a perspective view showing a light-emitting device 1c of a fourth embodiment. Fig. 6B is a perspective view showing a light-emitting device 1d of a fifth embodiment. Note that the configuration inside the recess 10a of the light-emitting device 1c is not shown here. In the light-emitting device 1c of the fourth embodiment shown in Fig. 6A, the lens structure 33 may be located on the flat plate 32 of the lid body 30 in the light-emitting device 1 of the first embodiment. In the light-emitting device 1d of the fifth embodiment shown in Fig. 6B, the lens structure 33d may be located on top of the flat plate 322 of the lid body 302 in the light-emitting device 1b of the third embodiment.

[0030] The lens structures 33 and 33d have collimating lens structures that reduce the diffusion of light emitted from the optical element 50 and further collimate or converge the light. The lens structure 33 may be bonded to the flat plate 32. Alternatively, the lens structure 33 and the flat plate 32 may be integrally formed. In one embodiment, the lens structure 33 and the flat plate 32 may be light-transmitting portions. The lens structure 33d may be integrally formed with the flat plate 322. Alternatively, the lens structure 33d may be bonded to the flat plate 322. In one embodiment, the lens structure 33d and the flat plate 322 may be light-transmitting portions. The convergence rate of the lens structures 33 and 33d may be different in a certain axial direction and in an axial direction perpendicular to the certain axial direction. Here, the lens structures 33 and 33d mainly converge the emitted light in the long side direction of the light-emitting devices 1c and 1d, but this is not limited thereto.

[0031] Sixth Embodiment Fig. 7A is a perspective view showing a main body 103 of a sixth embodiment. Fig. 7B is a cross-sectional view taken along the line BB in Fig. 7A. Fig. 7B also shows a cross-section of a circuit board 7 on which the light-emitting device 1 is mounted. As shown in Fig. 7A, one end of the optical element 50 may be directly electrically connected to the protrusion 121 without a bonding wire. As described above, the base 12 including the protrusion 121 may be made of copper or the like and have electrical conductivity.

[0032] As shown in FIG. 7B , an external electrode 124 may be located on the underside of the base 12. The external electrode 124 may be connected to a conductor layer 71, such as an electrode pad or ground plane, of the circuit board 7. The conductor layer 71 may be, for example, copper. The circuit board 7 may be, for example, a metal-core printed circuit board (MCPCB). The conductor layer 71 of the MCPCB has a protrusion that contacts the underside of the base 12. A plating layer serving as an anti-oxidation film may be located on the upper surface of this protrusion. The plating may be, for example, Ni plating or Au plating. The conductor layer 71 of the MCPCB may be separated vertically by an insulator 72. The insulator 72 may be, for example, an organic adhesive containing an insulating filler with high thermal conductivity. Therefore, heat can flow further downward through the insulator 72. The lower conductor layer 71 serves as a heat sink. On the other hand, current flowing along the conductor layer 71 is limited to the conductor layer 71 on the upper surface of the circuit board 7. That is, the upper conductor layer 71 is a wiring layer. The pattern edges of the wiring may be covered with solder resist. The wiring conductors on the circuit board 7 that connect to the external connection electrodes 117 outside the cross section of FIG. 7B are separated from the conductor layer 71 by insulators 73.

[0033] As in the main body 103 of the sixth embodiment, the heat dissipation path from the light emitting device 1 and one of the electrical paths may be partially common.

[0034] 8 is a cross-sectional view showing a main body 104 of a seventh embodiment. This cross section is the same as the cross-sectional line AA in FIG.

[0035] In the main body 104, the base 12 in the main body 10 of the first embodiment may have a protrusion 1211 instead of the protrusion 121. The other configurations and structures are the same. In the protrusion 1211, the mounting surface 121a for the optical element 50 may be inclined with respect to the upper surface 12a. The inclination angle may be within a range in which the optical path of the light emitted from the optical element 50 until it reaches the outside of the lid 30 is not significantly extended, and may be, for example, between 45 degrees and 90 degrees. The inclination angle here may be the smaller of the two angles that the mounting surface 121a forms with respect to the upper surface 12a.

[0036] 9 is a diagram showing an example in which a plurality of light-emitting devices 1c are arranged on a circuit board 7. As described above, the light-emitting device 1c itself can be made smaller than conventional devices, and therefore the size of the circuit board 7 can be made smaller compared to the overall required amount of light emission, i.e., the number of light-emitting devices 1c. Furthermore, a plurality of light-emitting devices 1c can be densely arranged on the circuit board 7.

[0037] As described above, the main body 10 of the optical element mounting package according to one embodiment of the present disclosure includes an insulating frame 11, a base 12 that is positioned to cover the lower end of the frame 11 and has a higher thermal conductivity than the frame 11, and a protrusion 121 that protrudes from the upper surface 12a of the base 12 toward a recess 10a surrounded by the frame 11 and the base 12. The frame 11 has an upper surface 11a on the upper end opposite the lower end to which a lid 30 having a translucent portion can be joined. The protrusion 121 intersects with the upper surface 12a and has a mounting surface 121a on which an edge-emitting optical element 50 can be mounted. In this manner, the main body 10 of the optical element mounting package can mount an edge-emitting optical element 50, which has higher light emission efficiency and light emission intensity compared to top-emitting types, etc., so that the edge-emitting optical element 50 faces directly toward the lid 30, thereby preventing diffusion of emitted light immediately after it is emitted outside the package. Therefore, compared to when light emitted from the optical element 50 is reflected toward the lid 30 by a mirror surface and then emitted to the outside, degradation of the light-emitting characteristics of the light-emitting device 1 using this optical element mounting package is reduced. In particular, interference between the emitted light from multiple light-emitting devices 1 is reduced, allowing multiple optical element mounting packages to be placed closer together than before. Furthermore, since the optical element 50 oriented in this manner is positioned in contact with the mounting surface 121a, which is the side surface of the protrusion 121, the optical element 50 is stably supported. Furthermore, since the protrusion 121 increases the contact area between the optical element 50 and the mounting surface 121a, the main body 10 can quickly dissipate heat generated by the optical element 50 to the protrusion 121. Therefore, the main body 10 can reduce deterioration and failure of the optical element 50 due to overheating.

[0038] Furthermore, the protrusion 121 has an integral structure with at least a part of the base 12, and this integral structure portion may penetrate from the top to the bottom surfaces of the base 12. This allows the main body 10 of the package for mounting an optical element to quickly release heat generated by the optical element 50 from the bottom surface side of the base 12 via the base 12 including the protrusion 121.

[0039] Furthermore, the mounting surface 121a may intersect with the upper surface 12a at an angle between 45 degrees and 90 degrees. In other words, the optical element 50 is not limited to emitting light in the normal direction of the upper surface 12a, i.e., directly upward. This allows the main body 10 to emit light in a flexible direction depending on the application. On the other hand, by preventing the inclination angle from becoming too small, the optical path length of the light emitted from the edge surface of the optical element 50 passing through the lid body 30 is kept within a range that does not significantly increase. Therefore, this main body 10 reduces deterioration of the light-emitting characteristics of the light-emitting device 1.

[0040] Furthermore, a plurality of optical elements 50 may be mountable on the mounting surface 121a. The short optical path length of the emitted light from the optical elements 50 before passing through the cover body 30 prevents the emitted light from diffusing and interfering with each other. Therefore, in this main body 10, the intervals between the mounting positions of the optical elements 50 can be made smaller than in the past. In other words, the main body 10 can be made smaller in size compared to the number of optical elements 50 that can be mounted.

[0041] Furthermore, the frame 11 may have wiring members 116, external connection electrodes 117, via conductors 118, and connection wiring 119 as wiring conductors connecting the optical element 50 to the outside. That is, electrical signals and power are supplied from the outside through the frame 11. Therefore, the path of the heat flow that mainly travels through the base 12 including the protrusion 121 is separated, and the electrical signals are less likely to be directly affected by heat.

[0042] Furthermore, the electrodes 115a and 115b electrically connected to the wiring conductors may be exposed on the frame 11. The surface including the electrodes 115a and 115b may be oriented along the mounting surface 121a. In this way, the electrodes 115a and 115b connected by the bonding wires W and the terminals of the optical element 50 on the mounting surface 121a face in approximately the same direction, so that the capillary only needs to move two-dimensionally during wire bonding. This facilitates wire bonding and reduces the effort and cost.

[0043] In particular, when viewed from the side directly facing the mounting surface 121a, the mounting surface 121a and the electrodes 115a, 115b are simultaneously visible, and the height from the upper surface 12a of the upper surface 11a of the frame 11 opposite the side where the electrodes 115a, 115b are located with respect to the protrusion 121 may be lower than the height from the upper surface 12a of the protrusion 121. This allows the movement of the capillary from the outside to the inside of the main body 10 to be limited to two-dimensional movement during wire bonding. Therefore, this main body 10 can be obtained at low cost through easier wire bonding.

[0044] The base 12 may also be made of aluminum, copper, or an alloy containing at least one of these. That is, the base 12 preferably has high thermal conductivity and is low cost. This allows the main body 10 to quickly dissipate heat generated by the optical element 50 to the outside.

[0045] The frame 11 may also be made of ceramic. The frame 11 is preferably made of an insulating material and a highly airtight material. Therefore, by using ceramic for the frame 11, high airtightness can be obtained.

[0046] Furthermore, the ceramic may be alumina. A base 12 with a high thermal conductivity often also has a high thermal expansion coefficient. If the difference in the thermal expansion coefficient of the frame 11 is large compared to this thermal expansion coefficient, large distortion is likely to occur between the frame 11 and the base 12, accelerating deterioration of the main body 10. Therefore, by using alumina, which is an inexpensive ceramic with a relatively high thermal expansion coefficient, for the frame 11, deterioration of the main body 10 can be reduced.

[0047] The package for mounting an optical element may have a flat plate 32 that is a light-transmitting portion through which light emitted by the optical element 50 passes, and may also include a lid 30 that can be joined to the top surface 11 a. By distributing the main body 10 and the lid 30 as a set as a package for mounting an optical element, the optical element 50 can be sealed by a suitable combination of lid 30 after mounting the optical element 50 on the main body 10.

[0048] Alternatively, a lens structure may be located on the flat plate 32, or a light-transmitting member having a lens structure may be used instead of the flat plate 32. By having a lens structure that converts the light emitted from the optical element mounting package into parallel light or the like from the beginning, it is not necessary to select and obtain a lens for the emitted light, or to adjust the optical axis during installation. Therefore, this optical element mounting package improves user convenience.

[0049] Furthermore, the light-emitting device 1 according to an embodiment of the present disclosure includes a main body 10 serving as the optical element mounting package described above, an optical element 50 mounted on the mounting surface 121a, and a lid 30 having a flat plate 32 through which light emitted from the optical element 50 passes and bondable to the upper surface 11a. The optical element 50 is mounted on the mounting surface 121a in a direction that allows light to be emitted out of the optical element mounting package via the flat plate 32. In this manner, the light-emitting device 1 according to an embodiment of the present disclosure can allow the edge-emitting optical element 50 to emit light directly upward. This shortens the optical path length from when the light emitted by the optical element 50 is emitted out of the lid 30. As a result, the light-emitting device 1 reduces degradation of optical characteristics.

[0050] The above embodiment is merely an example, and various modifications are possible. For example, the protrusion 121 does not necessarily have to be an integral structure with the base 12. If they are separate bodies, they can be joined together with a brazing material, solder, sintering material, or the like, which has high thermal conductivity. In this case, the protrusion 121 does not have to be mounted on the base 12. For example, the protrusion 121 may be half-buried in a hole located on the upper surface 12a of the base 12. This hole may penetrate the base 12.

[0051] In this case, the protrusions 121 may be made of a material different from that of the base 12. Even in this case, it is sufficient that heat is transferred between the protrusions 121 and the base 12 with high thermal conductivity.

[0052] In the above description, the positions and shapes of the electrodes 115a, 115b and the pillars 115c, 115d are determined in consideration of two-dimensional wire bonding. However, if the wire bonding is not limited to two-dimensional wire bonding, the positions and shapes of the electrodes 115a, 115b and the pillars 115c, 115d are not limited to those described above.

[0053] In the above description, four bonding wires W are connected in parallel, but this is not limiting. Any other number of bonding wires W may be used. Alternatively, instead of wires, a strip-shaped, particularly ribbon-shaped, conductor may be bonded to connect the electrodes and terminals.

[0054] In the sixth embodiment, only one signal path passes through the conductive base 12, but this is not limiting. Two signal paths may pass through the insulating base 12, no bonding wire W may be used, and the frame 11 may not have a wiring path. In this case, conversely, the frame 11 may be made of an electrically conductive material.

[0055] In addition to or instead of the via conductor 118, a castellation, a side electrode, or the like may be used.

[0056] Furthermore, the shapes of the mounting surface 121a of the protrusion 121 and the surface of the support base 112 including the electrodes 115a and 115b are not limited to those shown in the above embodiment, and may have other shapes.

[0057] Furthermore, the optical elements 50 mounted in a certain optical element mounting package may include optical elements that emit light of different wavelengths. For example, a red-emitting LD and a blue-emitting LD may be mounted in the same optical element mounting package.

[0058] Furthermore, in the optical element mounting packages of the third and fifth embodiments, the flat plate 322 of the lid 30 is positioned approximately in the center of the housing 312, but this is not limited to this. It may be positioned offset depending on the mounting position of the optical element 50. In addition, specific details such as the configuration, structure, positional relationship, and materials shown in the above embodiments can be modified as appropriate without departing from the spirit of the present disclosure. The scope of the present invention includes the scope of the invention described in the claims and their equivalents.

[0059] The present disclosure can be used in packages for mounting optical elements and light-emitting devices.

[0060] REFERENCE SIGNS LIST 1, 1b to 1d Light emitting device 10, 101 to 104 Main body 10a Recess 11 Frame body 11a Top surface 111 Protrusion 112 Support base 115a, 115b Electrode 115c, 115d Pillar 116 Wiring member 117 External connection electrode 118 Via conductor 119 Connection wiring 12 Base body 12a Top surface 121, 1211 Protrusion 121a Mounting surface 124 External electrode 13 Metal frame material 30, 302 Lid body 31 Frame body 312 Housing 32, 322 Flat plate 33, 33d Lens structure 40 Bonding member 50 Optical element 7 Circuit board 71 Conductor layer 72, 73 Insulator W Bonding wire

Claims

1. A package for mounting an optical element comprising: an insulating frame body; a heat transfer body having a higher thermal conductivity than the frame body and positioned to cover a first end of the frame body; and a protrusion protruding from a first surface of the heat transfer body into a space surrounded by the frame body and the heat transfer body, wherein the frame body has a first mounting surface on a second end side opposite the first end to which a lid body having a light-transmitting portion can be joined, and the protrusion has a second mounting surface intersecting the first surface and on which an edge-emitting optical element can be mounted.

2. The package for mounting an optical element according to claim 1, wherein said protrusion is integral with at least a portion of said heat conductor, said at least a portion penetrating said heat conductor.

3. An optical element mounting package according to claim 1 or 2, wherein the second mounting surface intersects with the first surface at an angle in the range of 45 degrees to 90 degrees.

4. An optical element mounting package according to any one of claims 1 to 3, wherein a plurality of optical elements can be mounted on the second mounting surface.

5. An optical element package according to any one of claims 1 to 4, wherein the frame has wiring conductors that connect the optical element to the outside.

6. A package for mounting an optical element as described in claim 5, wherein the frame has exposed electrodes electrically connected to the wiring conductor, and the surface including the electrodes is oriented along the second mounting surface.

7. A package for mounting optical elements as described in claim 6, wherein when viewed from the side directly opposite the second mounting surface, the second mounting surface and the electrode are simultaneously visible, and the height from the first surface of the side of the frame opposite the side on which the electrode is located relative to the protrusion is lower than the height from the first surface of the protrusion.

8. A package for mounting an optical element as described in any one of claims 1 to 7, wherein the heat conductor is aluminum, copper, or an alloy containing at least one of them.

9. The package for mounting an optical element according to any one of claims 1 to 8, wherein the frame is made of ceramic.

10. The package for mounting an optical element according to claim 9, wherein said ceramic is alumina.

11. A package for mounting an optical element as described in any one of claims 1 to 9, comprising a light-transmitting portion through which light emitted by the optical element passes, and a lid that can be joined to the first mounting surface.

12. The package for mounting an optical element according to claim 11, wherein said light-transmitting portion has a lens structure.

13. A light emitting device comprising: a package for mounting an optical element according to any one of claims 1 to 10; an optical element mounted on the second mounting surface; and a lid having a translucent portion through which light emitted by the optical element passes and capable of being joined to the first mounting surface, wherein the optical element is mounted on the second mounting surface in an orientation such that light is emitted outside the package for mounting an optical element via the translucent portion.

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