Package for mounting optical element and light emitting device

Abstract

To provide a package for mounting an optical element and a light emitting device with reduced degradation of optical properties.SOLUTION: A body (10) of a package for mounting an optical element 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 an upper surface (12a) of the base (12) into a recess (10a) surrounded by the frame (11) and the base (12). The frame (11) has a mounting surface on the side of an upper surface (11a) opposite the lower end to which a lid (30) having a light-transmitting flat plate (32) 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.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] There is a package that houses a laser light source and emits light emitted from the laser light source. In Patent Document 1, the light emitted from the light source in a direction along the bottom surface of the package is reflected upward by a mirror and emitted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 175303 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the optical path length inside the package becomes longer due to reflection, there is a problem in that the optical characteristics deteriorate.

[0005] Accordingly, there is provided an optical element mounting package and a light emitting device in which the deterioration of optical characteristics is reduced. [Means for solving the problem]

[0006] One aspect of the present disclosure is [1] A package for mounting an optical element comprising: an insulating frame body; a heat transfer body that is positioned to cover a first end of the frame body and has a thermal conductivity higher than that of the frame body; and a protrusion that protrudes 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 that intersects with the first surface and is capable of mounting an edge-emitting optical element. [2] The package for mounting an optical element according to [1], wherein the protrusion is integral with at least a portion of the heat conductor, and the at least a portion penetrates the heat conductor. [3] The package for mounting an optical element according to [1] or [2], wherein the second mounting surface intersects with the first surface at an angle of 45 degrees or more and 90 degrees or less. [4] The optical element mounting package according to any one of [1] to [3], wherein a plurality of optical elements can be mounted on the second mounting surface. [5] The package for mounting an optical element according to any one of [1] to [4], wherein the frame has a wiring conductor for connecting the optical element to an outside. [6] The package for mounting an optical element 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 package for mounting an optical element according to [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 of the side of the frame opposite the side on which the electrode is located relative to the protrusion from the first surface is lower than the height of the protrusion from the first surface. [8] The package for mounting an optical element according to any one of [1] to [7], wherein the heat conductor is made of aluminum, copper, or an alloy containing at least one of them. [9] The package for mounting an optical element according to any one of [1] to [8], wherein the frame is made of ceramic.

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

[11] The package for mounting an optical element according to any one of [1] to [9], further comprising a light-transmitting portion through which light emitted from 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

[11] , wherein the 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 [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 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 through the translucent portion. Effect of the Invention

[0007] According to the present disclosure, it is possible to reduce degradation of optical characteristics in a light emitting device. [Brief description of the drawings]

[0008] [Figure 1] 1 is an overall perspective view of a light emitting device according to a first embodiment; [Diagram 2] FIG. 2 is an exploded perspective view of a main body and a cover of the light emitting device. [Diagram 3] FIG. [Figure 4] 13A and 13B are a perspective view and a cross-sectional view showing a main body of a second embodiment. [Diagram 5] 13A and 13B are a perspective view showing a light emitting device according to a third embodiment, and an exploded perspective view showing a cover and a main body of the light emitting device separated from each other. [Figure 6] FIG. 13 is a perspective view showing light emitting devices according to fourth and fifth embodiments. [Figure 7] 13A and 13B are a perspective view and a cross-sectional view showing a main body of a sixth embodiment. [Figure 8] FIG. 13 is a cross-sectional view showing a main body of the seventh embodiment. [Figure 9] FIG. 13 is a diagram showing an example in which a plurality of light emitting devices are arranged on a circuit board. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment 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 the first embodiment. Fig. 2 is an exploded perspective view of a main body 10 and a cover body 30 of the light emitting device 1. The light emitting device 1 includes a main body 10, a cover 30, a light element 50, and the like.

[0010] The main body 10 is a housing of an optical element mounting package that houses an optical element 50 therein. The lid 30 seals the optical element 50 inside the main body 10. The lid 30 has a light-transmitting flat plate 32 positioned 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, or may be distributed independently of the optical element mounting package that includes only the main body 10.

[0011] The main body 10 has a frame 11 and a base 12. The base 12 is located inside the frame 11, closing the lower end (first end) of the frame 11, which is open at the top and bottom. The base 12 is a heat conductor and has a higher thermal conductivity than the frame 11. For example, the base 12 is a metal member such as copper or aluminum, or an alloy containing at least one of them. Alternatively, the base 12 may be a ceramic material. A single-crystalline inorganic material may be suitably used for the base 12. Furthermore, the base 12 may be a composite of an inorganic material and a metal that can obtain a high thermal conductivity. In other words, the base 12 may or may not have electrical conductivity.

[0012] The frame 11 has insulating properties. The frame 11 is, for example, alumina, aluminum nitride, silicon nitride, zirconia, or resin. Therefore, when ceramic, particularly alumina, is used as the main component of the frame 11, the airtightness of the frame 11 is higher than when a material other than ceramic is used. Furthermore, when ceramic is used as the main component of the frame 11, the difference in thermal expansion coefficient between the frame 11 and the base 12 can be made smaller than when a material other than ceramic is used. The frame 11 may have a structure in which multiple layers are laminated. In each layer, via conductors 118 are located, which penetrate the frame 11 in the thickness direction, and are connected to each other.

[0013] The frame 11 has an annular protrusion 111 extending inward from its inner surface. The protrusion 111 is integral with the frame 11 and is made of the same material. The peripheral portion of the upper surface 12a of the base 12 is joined to the lower surface side of the protrusion 111.

[0014] A recess 10a (space) is located and is surrounded by the inner side surface of the frame 11 and the upper surface 12a (first surface) of the base 12. A protrusion 121 protrudes from the upper surface 12a of the base 12 toward the recess 10a. The protrusion 121 has, for example, a rectangular parallelepiped shape. The height of the protrusion 121 from the upper surface 12a is higher 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.

[0015] One of the side surfaces of the protruding portion 121 that intersects with the upper surface 12a, i.e., is perpendicular to the upper surface 12a, is a mounting surface 121a (second mounting surface) for the optical element 50. The mounting surface 121a is the surface of the protruding portion 121 that faces the center of the recess 10a. One or more optical elements 50 can be bonded and mounted on the mounting surface 121a. For example, three optical elements 50 are positioned on the mounting surface 121a. The optical elements 50 are edge-emitting laser diodes (LDs). The optical elements 50 are in contact with the protruding portion 121 along their long sides. As a result, the optical elements 50 emit light outward through the lid 30 during operation, and the generated heat is quickly transferred to the base 12 via the protruding portion 121, which is a heat conductor.

[0016] Here, the optical element 50 is positioned so as to emit light vertically upward (opposite to the upper surface 12a) with respect to the upper surface 12a, but is not limited thereto. The optical element 50 may emit light in a slightly oblique direction with respect to the upper surface 12a.

[0017] The three optical elements 50 are connected in series, and both ends are connected to the electrodes 115a, 115b. The optical elements 50 and the optical elements 50 and the electrodes 115a, 115b are connected by bonding wires. For example, four pairs of bonding wires are connected in parallel to connect the electrodes 115a, the optical elements 50, and the electrodes 115b. By connecting by multiple pairs of bonding wires, even if one pair is broken, the optical elements 50 can still emit light by the other pairs of bonding wires.

[0018] The electrodes 115a, 115b are exposed on a side surface of the support base 112 located on the protrusion 111. The support base 112 is 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 a separate body from the frame body 11. That is, the support base 112 is joined to the frame body 11. The joining may be performed by a sintering paste or the like. The support base 112 has a wiring structure inside that is connected to the electrodes 115a, 115b, respectively. The portion of the support base 112 other than the wiring structure is an insulating material, and may be the same as that of the frame body 11, for example.

[0019] At this time, the electrodes 115a and 115b are located at positions where 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 is preferably in a direction along the mounting surface 121a. The direction along means that they 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 later, and is electrically connected to an external electrode located on the lower surface of the frame body 11.

[0020] An upper surface 11a (second end) of the frame 11 serves as a first mounting surface to which the lid 30 can be joined. The separate main body 10 and lid 30 are joined 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, the recess 10a may be filled with dry air or an inert gas.

[0021] As described above, the cover 30 has a frame 31 and a flat plate 32. The frame 31 may be the same material as the frame 11 of the main body 10, that is, for example, alumina. 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 by the cover 30, and are sufficiently small. As a result, the light emitted by the optical element 50 has an optical path length according to the thickness of the cover 30. The optical path length, especially the optical path length inside the recess 10a, is short, thereby suppressing the diffusion of the emitted light. Accordingly, interference between the emitted lights is less likely to occur compared to a case where there is no protrusion 121 and the optical path length inside the recess 10a of the light emitted from near the upper surface 12a is longer than the optical path length of this embodiment. Therefore, the intervals between the multiple optical elements 50 mounted on the mounting surface 121a can be narrowed. The size of the package for mounting an optical element in plan view can also be reduced according to the intervals between the optical elements 50.

[0022] The flat plate 32 is an airtight, light-transmitting member (translucent portion), such as borosilicate glass or sapphire glass. The surface of the flat plate 32 may be anti-reflective coated (AR coated). The flat plate 32 is joined to the frame 31 using, for example, frit glass.

[0023] The main body 10 and the cover 30 can be joined via a joining member 40. For example, gold-tin or the like is used for the joining member 40. For gold-tin, for example, an annular preform narrower than each of the frames 11, 31 can be used as a seal ring.

[0024] Alternatively, frit glass or the like may be used for bonding. In this case, a material having a lower melting point than the frit glass of the lid body 30 is used so that the bonding surface between the frame body 31 and the flat plate 32 in the lid body 30 is not remelted during bonding. The low-melting frit glass contains, for example, a mixture of metals such as tellurium, bismuth, and vanadium.

[0025] FIG. 3 is a cross-sectional view of the body 10 taken along section line AA. In this cross-sectional view including electrode 115a, a wiring member is connected between electrode 115a and external connection electrode 117 located on the bottom surface of frame 11.

[0026] Specifically, a plurality of via conductors 118 are overlapped within the frame 11, and are connected to a connection wiring 119 located on the upper surface of the protrusion 111. The electrode 115a is connected to a wiring member 116 (wiring conductor) extending inside the support base 112. The wiring member 116 is exposed from the lower end of the support base 112 and is 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 connected to the electrode 115a by the bonding wire W to the outside.

[0027] In this way, the heat dissipation path from the optical element 50 is mainly the base body 12, while the electrical path to the optical element 50 is the frame body 11. That is, 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 therefore changes in the resistance value of the electrical path are suppressed. Meanwhile, as described above, the heat dissipation path is wide and has a remarkably high thermal conductivity. Therefore, heat is quickly dissipated from the optical element 50.

[0028] [Second embodiment] FIG. 4 is a perspective view (FIG. 4(a)) showing a main body 101 of the second embodiment, and a cross-sectional view (FIG. 4(b)) taken along the cross-sectional line AA. The main body 101 does not have a support base 112. The main body 101 has independently standing electrode pillars (pillars 115c, 115d) instead of the electrodes 115a, 115b. The contact portions of the pillars 115c, 115d with the protrusion 111 may be thicker for stability. The pillars 115c, 115d may have any shape. However, the bonding portion of the bonding wire W is partially flat and substantially parallel to the mounting surface 121a, which facilitates wire bonding work.

[0029] 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 brazing, for example.

[0030] [Third embodiment] FIG. 5 is a perspective view (FIG. 5(a)) showing a light emitting device 1b of the third embodiment, and an exploded perspective view (FIG. 5(b)) showing a cover 302 and a main body 102 of the light emitting device 1b separated from each other.

[0031] The light emitting device 1b has 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 in the figure, 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 of the optical element 50 to be emitted without being obstructed. The housing 312 having such a three-dimensional shape may be obtained by molding a metal member by drawing, for example.

[0032] The main body 102 is the same as 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 11. The same components are given the same reference numerals and detailed description is omitted. The metal frame material 13 is, for example, a low-resistance material, such as Kovar (registered trademark). The metal frame material 13 overlaps the position where the lower end of the housing 312 contacts the main body 102 in a plan view, that is, the lower end of the housing 312 and the metal frame material 13 are joined. Since both the housing 312 and the metal frame material 13 are low-resistance metals, they may be joined by seam welding.

[0033] [Fourth and fifth embodiments] 6 is a perspective view showing light emitting devices 1c and 1d according to the fourth and fifth embodiments, in which the configuration inside the recess 10a of the light emitting device 1c is omitted. In a light emitting device 1c of a fourth embodiment shown in Fig. 6(a), a lens structure 33 is located on the flat plate 32 of the lid body 30 in the light emitting device 1 of the first embodiment. In a light emitting device 1d of a fifth embodiment shown in Fig. 6(b), a lens structure 33d is located on top of the flat plate 322 of the lid body 302 in the light emitting device 1b of the third embodiment.

[0034] The lens structures 33 and 33d have a collimating lens structure that reduces the diffusion of the light emitted from each of the optical elements 50 and further collimates or converges the light. The lens structure 33 is a separate structure from the flat plate 32 (light-transmitting portion) that is bonded to the flat plate 32, but may be integrally formed with the flat plate 32. The lens structure 33d is a separate structure from the flat plate 322 that may be bonded to the flat plate 322. The convergence rate of the lens structures 33 and 33d may be different between a certain axial direction and an axial direction perpendicular thereto. 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.

[0035] [Sixth embodiment] FIG. 7 is a perspective view and a cross-sectional view showing a main body 103 of the sixth embodiment. Fig. 7(b) is a cross-sectional view taken along line BB in Fig. 7(a) Also shown in Fig. 7(b) is a cross-sectional view of a circuit board 7 on which the light emitting device 1 is attached. 7(a), one end of the optical element 50 is directly electrically connected to the protruding portion 121 without a bonding wire. As described above, the base 12 including the protruding portion 121 may be made of an electrically conductive material such as copper.

[0036] As shown in FIG. 7(b), an external electrode 124 may be located on the lower surface of the substrate 12. The external electrode 124 may be connected to a conductor layer 71, such as an electrode pad or a 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 wiring board (MCPCB). The conductor layer 71 of the MCPCB has a protrusion that contacts the lower surface of the substrate 12. A plating layer may be located on the upper surface of the protrusion as an oxidation prevention film. The plating may be, for example, Ni plating or Au plating. The conductor layer 71 of the MCPCB is vertically separated by an insulator 72. The insulator 72 may be, for example, an organic adhesive containing an insulating filler having high thermal conductivity. Therefore, heat can pass through the insulator 72 and flow further downward. The lower conductor layer 71 serves as a heat sink. On the other hand, the current along the conductor layer 71 flows only in 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 a solder resist. The wiring conductor on the circuit board 7 that connects to the external connection electrode 117 outside the cross section of FIG. 7(b) is separated from the conductor layer 71 by an insulator 73.

[0037] Like 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.

[0038] [Seventh embodiment] FIG. 8 is a cross-sectional view showing a main body 104 of the seventh embodiment. This section is identical to the section line AA in FIG.

[0039] In the main body 104, the base 12 in the main body 10 of the first embodiment has a protrusion 1211 instead of the protrusion 121. The other configurations and structures are the same. In the protrusion 1211, the mounting surface 121a of the optical element 50 is 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, 45 degrees or more and 90 degrees or less. The inclination angle here may be the smaller of two angles that the mounting surface 121a makes with respect to the upper surface 12a.

[0040] FIG. 9 is a diagram showing an example in which a plurality of light emitting devices 1c are arranged on a circuit board . As described above, the light emitting device 1c itself can be made smaller than before, so 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.

[0041] As described above, the main body 10 of the package for mounting an optical element according to this embodiment 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 protruding portion 121 that protrudes from an upper surface 12a of the base 12 into a recess 10a surrounded by the frame 11 and the base 12. The frame 11 has an upper surface 11a on the upper end side opposite to the lower end thereof to which a lid 30 having a light-transmitting portion can be joined. The protruding portion 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 way, the main body 10 of the package for mounting optical elements can mount the optical element 50 of the edge-emitting type, which has a higher light emission efficiency and light emission intensity than the top-emitting type, so that the optical element 50 faces directly to the lid 30, and the emitted light does not diffuse immediately after being emitted to the outside of the package. Therefore, the deterioration of the light emission characteristics of the light emitting device 1 using this package for mounting optical elements is suppressed compared to the case where the light emitted by the optical element 50 is reflected toward the lid 30 by a mirror surface and emitted to the outside. In particular, since the emitted light from the multiple light emitting devices 1 is less likely to interfere with each other, multiple packages for mounting optical elements can be arranged closer than before. In addition, since the optical element 50 oriented in this way 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 contact area between the optical element 50 and the mounting surface 121a is increased by the protrusion 121, the main body 10 can quickly release the 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.

[0042] Moreover, the protrusion 121 is integral with at least a part of the base 12, and this integral portion penetrates 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.

[0043] Moreover, the mounting surface 121a may intersect with the upper surface 12a at an angle between 45 degrees and 90 degrees. That is, 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 according to 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 end surface of the optical element 50 passing through the cover body 30 is kept within a range that does not become significantly long. Therefore, this main body 10 prevents the deterioration of the light emitting characteristics of the light emitting device 1.

[0044] 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 passing through the cover 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. That is, the main body 10 can be made smaller in size compared to the number of optical elements 50 that can be mounted.

[0045] Furthermore, the frame 11 has 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.

[0046] Furthermore, the electrodes 115a and 115b electrically connected to the wiring conductor are exposed on the frame 11. The surface including the electrodes 115a and 115b is oriented along the mounting surface 121a. In this manner, the electrodes 115a and 115b connected by the bonding wire W and the terminals of the optical element 50 on the mounting surface 121a face in substantially the same direction, so that the capillary only needs to move two-dimensionally during wire bonding. This makes wire bonding easier and reduces the effort and cost.

[0047] In particular, when viewed from the side directly opposite to 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 protruding portion 121 is lower than the height from the upper surface 12a of the protruding portion 121. This makes it possible to restrict the movement of the capillary from the outside to the inside of the main body 10 during wire bonding to a two-dimensional movement. Therefore, the main body 10 can be obtained at low cost by easier wire bonding.

[0048] The base 12 may be made of aluminum or copper, or an alloy containing at least one of them. In other words, the base 12 is preferably made of a material having high thermal conductivity and low cost. This allows the main body 10 to quickly dissipate heat generated by the optical element 50 to the outside.

[0049] Also, it is preferable that the frame 11 is made of ceramic. It is preferable that the frame 11 is made of an insulating material and has high airtightness. Therefore, by making the frame 11 of ceramic, high airtightness can be obtained.

[0050] Furthermore, the ceramic may be alumina. A base 12 with a high thermal conductivity often also has a high thermal expansion coefficient. If there is a large difference in the thermal expansion coefficient of the frame 11 with respect to this thermal expansion coefficient, a large distortion is likely to occur between the frame 11 and the base 12, accelerating the deterioration of the main body 10. Therefore, by using alumina, which is an inexpensive ceramic with a relatively large thermal expansion coefficient, for the frame 11, the deterioration of the main body 10 can be reduced.

[0051] The package for mounting an optical element may have a flat plate 32 which is a light-transmitting portion through which light emitted by the optical element 50 passes, and may include a lid 30 which can be joined to the upper surface 11a. 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 the lid 30 after mounting the optical element 50 on the main body 10.

[0052] Also, 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 emitted light of the package for mounting an optical element into parallel light or the like from the beginning, it becomes unnecessary to select and obtain a lens for the emitted light, and to adjust the optical axis when mounting the package. Therefore, this package for mounting an optical element improves user convenience.

[0053] The light emitting device 1 of this embodiment includes the main body 10 as the package for mounting an optical element, the optical element 50 mounted on the mounting surface 121a, and a lid 30 that has a flat plate 32 through which light emitted by the optical element 50 passes and can be joined to the upper surface 11a. The optical element 50 is mounted on the mounting surface 121a in a direction that emits light to the outside of the package for mounting an optical element via the flat plate 32. In this way, the light emitting device 1 of this embodiment can emit light directly upward from the edge-emitting optical element 50. This shortens the optical path length from when the light emitted from the optical element 50 is emitted to the outside of the lid body 30. As a result, the light emitting device 1 is prevented from deteriorating in optical properties.

[0054] The above-described 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 having high thermal conductivity. In this case, the protrusion 121 does not necessarily have to be placed on the base 12. It may be half embedded in a hole located on the upper surface 12a of the base 12. This hole may penetrate the base 12.

[0055] In this case, the protrusion 121 may be made of a material different from that of the base 12. Even in this case, it is more preferable that heat is transferred between the protrusion 121 and the base 12 with high thermal conductivity.

[0056] In the above, 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 the above.

[0057] In the above description, four bonding wires W are connected in parallel, but this is not limited to this. Any other number of wires may be used. Alternatively, a strip-shaped (ribbon-shaped) conductor may be bonded instead of the wires to connect between the electrodes and the terminals.

[0058] In the sixth embodiment, only one signal path passes through the conductive base 12, but this is not limited to the above. 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, the frame 11 may be made of an electrically conductive material.

[0059] In addition to or instead of the via conductor 118, a castellation, a side electrode, or the like may be used.

[0060] Furthermore, the shapes of the mounting surface 121a of the protruding portion 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.

[0061] Furthermore, the optical elements 50 mounted in a package for mounting an optical element may include those emitting light of different wavelengths. For example, a red-emitting LD and a blue-emitting LD may be mounted in the same package for mounting an optical element.

[0062] In the optical element packages according to the third and fifth embodiments, the flat plate 322 of the lid 30 is located approximately in the center of the housing 312, but this is not limiting. It may be located in a biased position depending on the mounting position of the optical element 50. In addition, the specific details of the configuration, structure, positional relationship, materials, etc. shown in the above embodiment can be appropriately changed 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 its equivalents. [Explanation of symbols]

[0063] 1, 1b to 1d Light emitting device 10, 101-104 Main unit 10a Recess 11 Frame 11a Top side 111 Protrusion 112 Support stand 115a, 115b electrode 115c, 115d pillar 116 Wiring materials 117 External connection electrode 118 Via conductor 119 Connection Wiring 12 Base 12a Top side 121, 1211 Protrusion 121a Mounting surface 124 External electrode 13 Metal frame material 30, 302 Lid 31 Frame 312 Case 32, 322 flat plate 33, 33d lens structure 40 Joint materials 50 Optical elements 7 Circuit Board 71 Conductor Layer 72, 73 Insulators W Bonding Wire

Claims

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

2. 2. The optical element mounting package according to claim 1, wherein the protrusion is integral with at least a portion of the heat conductor, and the at least a portion penetrates the heat conductor.

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

4. 2. The optical element mounting package according to claim 1, wherein a plurality of optical elements can be mounted on said second mounting surface.

5. 2. The optical element package according to claim 1, wherein said frame has a wiring conductor for connecting said optical element to the outside.

6. The frame has an exposed electrode electrically connected to the wiring conductor, 6. The optical element mounting package according to claim 5, wherein the surface including the electrodes is in a direction parallel to the second mounting surface.

7. 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. 2. The optical element package according to claim 1, wherein the heat conductor is made of aluminum, copper, or an alloy containing at least one of them.

9. 2. The optical element package according to claim 1, wherein said frame is made of ceramic.

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

11. 2. The optical element mounting package according to claim 1, further comprising a lid body having a light transmitting portion through which light emitted by the optical element passes and bondable to the first mounting surface.

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

13. An optical element mounting package according to any one of claims 1 to 10, an optical element mounted on the second mounting surface; a cover body having a light transmitting portion through which light emitted by the optical element passes and which can be joined to the first mounting surface; Equipped with The optical element is mounted on the second mounting surface in a direction in which light is emitted to the outside of the optical element mounting package through the light-transmitting portion. Light emitting device.

Images