Optical element mounting package and light-emitting device

Abstract

An optical element mounting package according to the present invention comprises a base, a heat transfer body, and a via conductor and a wiring layer that are wiring conductors. The base has a first surface on which a cover body can be mounted and a through hole that passes through the first surface. The heat transfer body has a base part that is passed through the through hole to protrude from the first surface, and an optical element can be mounted on the base part. The wiring conductors extend from the inside to the outside of a mounting area for the cover body. A connection electrode and an external electrode that are at respective ends are both positioned on the surface of the base. The first surface of the base or the base part includes a fixing surface to which a focusing lens can be fixed. A continuous annular first joining material is positioned between the base and the heat transfer body and joins the base and the heat transfer body airtight.

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] As the required amount of light increases, there are light-emitting devices that converge and output light emitted by multiple optical elements. In light-emitting devices that use optical elements such as laser diodes, the optical elements are sealed in a package that reduces deterioration of the optical elements and a decrease in the amount of light emitted, and are isolated from the air. In addition, Japanese Patent Application Laid-Open No. 2022-163475 discloses a technology in which a condenser lens that condenses the emitted light is also incorporated into the package to quickly reduce the diffusion of light.

[0003] [1] An optical element mounting package comprising: a base having a first surface on which a lid body can be mounted and a through hole penetrating between the first surface and a surface opposite the first surface; a heat transfer body having a thermal conductivity higher than that of the base and having a platform portion protruding from the first surface through the through hole, on which an optical element can be mounted on the platform; and a wiring conductor extending across an area inside and outside the mounting area of ​​the lid body, with both ends of the wiring conductor located on a surface of the base, wherein the first surface of the base or the platform portion includes a fixing surface on which at least one focusing lens can be fixed, and a ring-shaped first bonding material is continuously located between the base and the heat transfer body, and the base and the heat transfer body are hermetically bonded by the first bonding material. [2] The optical element mounting package of [1], wherein the first bonding material is a brazing material. [3] The optical element package according to [1] or [2], wherein the wiring conductor passes through the inside of the base, connecting the inside and outside of the mounting area of ​​the lid. [4] The optical element package according to any one of [1] to [3], wherein the wiring conductor and the base each contain inorganic particles of the same component different from the main component of the base. [5] The optical element package according to any one of [1] to [4], wherein a ring-shaped first connector is located at a portion of the first surface that is bonded to the lid. [6] The optical element package according to [5], wherein the first bonding material, the first connector, and the base each contain inorganic particles of the same component different from the main component of the base. [7] The optical element package according to [5] or [6], wherein a second connector to which the condenser lens is fixed is located between the platform portion and the first connector on the first surface in a plan view seen from above the first surface. [8] The package for mounting an optical element according to any one of [1] to [7], wherein the heat transfer body includes a portion located outside the range of the through hole in a plan view seen from above the first surface. [9] The package for mounting an optical element according to any one of [1] to [8], comprising a lid that seals a space on the first surface including an area occupied by the condenser lens and the optical element connected to the first surface or the base.

[10] A light-emitting device comprising the package for mounting an optical element according to [9], an optical element, and at least one condenser lens.

[0004] 1 is a general perspective view showing the appearance of a light emitting device according to a first embodiment; FIG. 1 is a perspective view of a light emitting device with a lid removed; FIG. 2 is a perspective view showing a base and a heat conductor separated from each other; FIG. 3 is a cross-sectional view of a light emitting device with a lid removed; FIG. 4 is a cross-sectional view of a light emitting device with a lid removed; FIG. 5 is a cross-sectional view of a light emitting device with a lid removed; FIG. 6 is a perspective view of an example of a light emitting module equipped with a plurality of light emitting devices; FIG. 7 is a perspective view of a light emitting device according to a second embodiment with a lid removed; FIG. 8 is a perspective view showing a package base and a heat conductor separated from each other; FIG. 9 is a cross-sectional view of a light emitting device with a lid removed; FIG. 10 is a cross-sectional view of a light emitting device with a lid removed; FIG. 11 is a cross-sectional view of a light emitting device with a lid removed; FIG. 12 is a cross-sectional view of a light emitting device with a lid removed; FIG. 13 is a cross-sectional view of a light emitting device with a lid removed; FIG. 14 is a cross-sectional view of a light emitting device with a lid removed; FIG. 15 is a cross-sectional view of a light emitting device with a lid removed; FIG. 16 is a cross-sectional view of a light emitting device with a lid removed; FIG. 17 is a cross-sectional view of a light emitting device with a lid removed;

[0005] Hereinafter, embodiments will be described with reference to the drawings. [First Embodiment] Fig. 1 is an overall perspective view showing the appearance of a light emitting device 1 of the first embodiment. The light emitting device 1 has a package 10 and a lid 30. The internal space covered by the package 10 and the lid 30 is sealed. The internal space includes an area occupied by a condenser lens 50 and a light emitting unit 40 fixed to the package 10. The surface of the package 10 on which the condenser lens 50 and the light emitting unit 40 are mounted is referred to as the upper surface.

[0006] The package 10, which is a package for mounting an optical element according to this embodiment, is a combination of a base 11 and a heat conductor 12. An external electrode 115 is located outside the area where the lid 30 is mounted and sealed on the first surface 11u, which is the top surface of the base 11, near the edge on the -X side in this case. The base 11 is an insulating material and may be a ceramic member. The base 11 may be, for example, aluminum oxide (alumina). The heat conductor 12 is a member with a higher thermal conductivity than the base 11. The heat conductor 12 may be a metal, and when the base 11 is alumina, it may be, for example, copper, aluminum, nickel, iron, molybdenum, manganese, silver, gold, or the like. Furthermore, the heat conductor 12 is less likely to distort when heated if its coefficient of thermal expansion is closer to that of the base 11. Therefore, when the base 11 is alumina, it may be made of copper or iron, particularly oxygen-free copper, among the above materials.

[0007] The lid 30 has a recessed shape with an open -Z side surface that contacts the package 10. When the lid 30 is bonded to the package 10, the recessed portion is sealed as an internal space. The +X side surface of the lid 30 is covered with a light-transmitting member 31, forming a window through which light emitted from the internal space is emitted to the outside of the internal space. That is, here, the X axis is defined along the light emission direction in a plane parallel to the first surface 11u. The X axis direction may also coincide with the longitudinal direction of the package 10 when viewed from above. The -Z side end surface of the side surface of the lid 30 is a bonding surface 32 that opens outward, ensuring a bonding area with the package 10. This reduces sealing leakage in the internal space surrounded by the package 10 and the lid 30. The annular area surrounded by the portion of the first surface 11u where the lid 30 is bonded is the mounting area on the package 10 where an optical element 41 and a condenser lens 50, described below, are mounted.

[0008] 2 is a perspective view of the internal space of the light-emitting device 1 with the lid 30 removed. A ring-shaped first connector 112, to which the lid 30 is joined, is located on the +Z side surface of the package 10. The base 121 of the heat transfer body 12 and the connection electrode 111 are located in the area surrounded by the first connector 112. The base 121 has two stepped surfaces at different positions in the Z direction, and the light-emitting unit 40 is mounted on the upper step. A condenser lens 50 is fixed in the area overlapping with the lower step in a plan view from the +Z side. The first connector 112 is a sealing member suitable for joining with the lid 30 and may be made of metal.

[0009] The light-emitting unit 40 may be a chip-on-submount (CoS) type having an optical element 41 and a submount 42 that supports the optical element 41. The optical element 41 may be a laser diode. The optical element 41 emits light parallel to the upper surface of the base 121 toward the light-transmitting member 31 in the +X direction. The submount 42 is fixed to the upper surface of the base 121.

[0010] The condenser lens 50 is located on the ray of light emitted from the optical element 41. The condenser lens 50 may be bonded to the +X side surface of the upper stage of the base 121 and located away from the upper surface of the lower stage. The condenser lens 50 may be a fast-axis collimator (FAC) lens that condenses light in the fast axis direction. At least one condenser lens 50 is located and fixed within the mounting range of the first surface 11u. That is, all of the condenser lenses that condense light emitted from a certain optical element 41 may be located within the mounting range, or some of the condenser lenses may be located outside the mounting range.

[0011] The optical element 41 is connected to the connection electrode 111 by a bonding wire W. The connection electrode 111 is connected to an external electrode 115 as described below, and the optical element 41 emits light when power is supplied from the external electrode. The connection electrode 111 and the external electrode 115 only need to have high and stable electrical conductivity. For example, the connection electrode 111 and the external electrode 115 may be gold-plated on the surface of a nickel underlayer.

[0012] FIG. 3 is a perspective view showing the base 11 and the heat transfer body 12 separated from each other. The base 11 has a through-hole 11t penetrating between the first surface 11u and the surface opposite the first surface 11u. The direction along the through-hole 11t, i.e., the direction perpendicular to the first surface 11u, is defined as the Z-direction. The direction perpendicular to the X-axis and Z-axis and forming a left-handed system is defined as the Y-axis direction. The base portion 121 of the heat transfer body 12 penetrates the through-hole 11t and protrudes from the first surface 11u of the base 11 toward the +Z side. The base 11 and the heat transfer body 12 are hermetically bonded together with a bonding material. Therefore, no air flows through the gap between the base 11 and the heat transfer body 12 and the first surface 11u of the base 11, i.e., the internal space sealed by the lid 30.

[0013] 4A to 4C are cross-sectional views taken along the cross-sectional line ii in FIG. 2 and diagrams illustrating other embodiments of this cross section. As described above, in the present embodiment shown in FIG. 4A , a columnar pedestal 121 penetrates the through-hole 11t. The bottom surface of the base 11 on the -Z side and the top surface of the heat transfer body 12 on the +Z side are bonded together by a first bonding material 60. The first bonding material 60 is positioned continuously around the periphery of the pedestal 121 in a circular shape in a plan view, thereby hermetically bonding the base 11 and the heat transfer body 12 together. The width of the first bonding material 60 may be determined appropriately taking into consideration ensuring airtightness, cost, and effort. The first bonding material 60 may be a brazing material that does not remelt during subsequent heat treatment, such as a brazing material containing AuGe.

[0014] As such, the light-emitting unit 40 is located directly on the heat conductor 12. Therefore, heat generated by the light emission of the laser diode, which is the optical element 41, is rapidly transferred to the bottom surface of the package 10 via the heat conductor 12 and dissipated. In particular, in this embodiment, the heat conductor 12 extends beyond the planar view of the through-hole 11t on the -Z side of the base 11, allowing for efficient heat dissipation. This reduces the possibility of deterioration or failure of the optical element 41, package 10, etc. due to high temperatures. Furthermore, when the temperature of the package 10 rises during light emission of the optical element 41, distortion occurs depending on the difference in thermal expansion coefficients between the heat conductor 12 and the base 11. If such distortion is significant, it may also impose a load on the package 10, potentially affecting stable, long-term use. By minimizing the difference in thermal conductivity between the heat conductor 12 and the base 11 as much as possible within the range that satisfies conditions such as airtightness, bonding stability, and heat dissipation, distortion can be reduced without the need for additional measures. This reduces load-induced degradation of the package 10, making it easier to use it stably for long periods of time.

[0015] The base 11 may have a wiring layer 114 near the center in the Z direction, i.e., the thickness direction, inside the substrate member 110, which is an insulator such as ceramic, as described above. At least a portion of the wiring layer 114 extends across an area surrounded by the first connector 112 in a plan view, i.e., across the inside and outside of the mounting area of ​​the lid 30. The connection electrode 111 and the external electrode 115 are electrodes at both ends electrically connected by wiring conductors including the via conductors 113 and the wiring layer 114 that extend across the inside and outside areas separated by the lid 30. The width of the wiring layer 114 in the Y direction, which is perpendicular to the extending direction, may be determined as appropriate. Furthermore, the wiring layer 114 may include a conductor surface that is not connected to other conductive members or is connected to a ground plane, in addition to the path connecting the connection electrode 111 and the external electrode 115.

[0016] The condensing lens 50 may be fixed near the upper end of the side surface 121s located on the +X side of the base 121 by a third bonding material 62. That is, the side surface 121s may be the fixing surface for the condensing lens 50. Alternatively, the upper surface of the lower step of the base 121 may be used as the fixing surface, and the condensing lens 50 may be fixable to this fixing surface. The condensing lens 50 is fixed in alignment with the optical element 41 after the light-emitting unit 40 is fixed. Therefore, the third bonding material 62 has a lower melting point than the second bonding material 61, e.g., AuSn solder, which fixes the light-emitting unit 40. For example, the third bonding material 62 may be SAC solder containing tin, silver, and copper. Because light emitted from the optical element 41 is incident on the condensing lens 50 before it diverges significantly, the condensing lens 50 is not significantly larger than the optical element 41.

[0017] 4B, the area of ​​the heat transfer body 12a in contact with the bottom surface of the base 11 is smaller than that of the first embodiment. The size of the bottom surface of the heat transfer body 12a may be within a required range depending on the area of ​​contact between the heat transfer body 12a and a heat dissipation member such as a heat dissipation fin.

[0018] In another embodiment shown in FIG. 4C , the through hole 11tb has a two-step shape in which areas of different planar areas overlap. The heat transfer body 12b has a two-step shape that fits into the two-step shape of the through hole 11tb. The heat transfer body 12b and the substrate member 110b are hermetically bonded at the stepped portion by the first bonding material 60. In this embodiment, the heat transfer body 12b does not protrude from the bottom surface of the substrate member 110b, making it easier to reduce the thickness of the package 10. Furthermore, even if pressure is applied from above when fixing the bonding wires W, the force is applied substantially uniformly to the bottom surface of the package 10, making it less likely to break the package 10 without taking any other measures. This reduces the effort required for manufacturing and assembly, and also makes it easier to reduce yield reductions.

[0019] After the light-emitting unit 40 and the condenser lens 50 are bonded to the package 10 as described above, the bonding surface 32 of the lid 30 and the first connector 112 of the package 10 are bonded with a bonding material. This seals the internal space containing the light-emitting unit 40. Bonding may be performed using a material with a lower melting point than the first bonding material 60, the second bonding material 61, and the third bonding material 62, such as tin-bismuth solder. Furthermore, the first bonding material 60, the second bonding material 62, the third bonding material 62, and the first connector 112 may contain, as a filler, the same component as the inorganic particles other than the main component contained in the base 11. When the base 11, the first bonding material 60, the second bonding material 61, the third bonding material 62, and the first connector 112 contain the same inorganic particles, they bond together during bonding, improving bonding strength. The inorganic particles may be inorganic metal or silicon dioxide (silica).

[0020] 5 is a perspective view showing an example of a light emitting module 100 equipped with a plurality of light emitting devices 1. The light emitting module 100 has, for example, four light emitting devices 1. The path of light emitted from each light emitting device 1 is indicated by a dotted line.

[0021] The plurality of light emitting devices 1 arranged in parallel are positioned next to each other on a base 5. Light emitted from each light emitting device 1 after passing through a light transmitting member 31 is collected by a respective collecting lens 2. The collecting lens 2 collects light in an axial direction different from that of the collecting lens 50. In other words, when the collecting lens 50 is an FAC lens, the collecting lens 2 is a SAC (Slow-Axis Collimator) lens that collects light in the slow axis direction.

[0022] Each light passing through the condenser lens 2 is converted by the mirror 3 into parallel light narrower than the spacing between the light-emitting devices 1. These lights are further condensed and combined by the condenser lens 4 and output. In this way, in the light-emitting module 100 that combines and outputs light from multiple optical elements 41, by individually sealing as few optical elements 41 as possible, a decrease in yield is reduced. Furthermore, particularly as the sealed volume increases and more substances are contained in the internal space, impurities are more likely to volatilize, elute, and be mixed into the internal space. Therefore, by reducing the sealed volume, unintended mixing of impurities is reduced, and adverse effects on the performance of the optical elements 41 are reduced. Furthermore, the number of individually sealed light-emitting devices 1 can be easily changed by replacing the base 5.

[0023] Second Embodiment Figure 6 is a perspective view showing a light emitting device 1c according to a second embodiment with the lid 30 removed. The light emitting device 1c includes a package 10c, a lid 30, a light emitting unit 40, and a condenser lens 50c. The lid 30 is the same as the lid 30 of the light emitting device 1, and therefore a description thereof will be omitted. The package 10c includes a base 11c and a heat transfer body 12c. The size of the heat transfer body 12c in a plan view may be smaller than the rightmost portion of the base 11c in a plan view.

[0024] The base 11c has a second connector 116 on the first surface 11u. A condenser lens 50c is fixed to the second connector 116. The condenser lens 50c may be an integrated lens that condenses light in both the fast axis direction and the slow axis direction. Alternatively, the condenser lens 50c may be an FAC lens, similar to the condenser lens 50 described above. The second connector 116 is a member suitable for fixing the condenser lens 50c with the third bonding material 62, and may be made of the same material and have the same structure as the connection electrode 111 and the external electrode 115, for example.

[0025] The base 121c of the heat transfer body 12c has a columnar shape, and the light emitting unit 40 is fixed to the upper end surface. Other components, such as the external electrode 115, the connection electrode 111, and the first connector 112, are identical in configuration. The positional relationship between these components may be different from that of the light emitting device 1 of the first embodiment.

[0026] FIG. 7 is a perspective view showing the base 11c and heat transfer body 12c of the package 10c separated from each other. As described above, the base portion 121c of the heat transfer body 12c passes through the through-hole 11tc of the base 11c. The base portion 121c may have a rectangular columnar cross section with rounded corners. Here, an example is shown in which the through-hole 11tc is closer to the -X side than the light-emitting device 1, depending on the size of the second connector 116. However, the size of the second connector 116 and the position of the through-hole 11tc may be adjusted depending on the size of the condenser lens 50c.

[0027] An upper surface 121t of the base portion 121c defines a mounting position for the light emitting unit 40. The package 10c may or may not have a marking or the like at the mounting position.

[0028] 8A to 8C are cross-sectional views taken along the cross-sectional line vi in ​​FIG. 6 and diagrams illustrating other embodiments of this cross section. In the cross-sectional view of this embodiment shown in FIG. 8A, the base portion 121c of the heat transfer body 12c penetrates the through-hole 11tc of the base 11c upward from the bottom side of the base 11c toward the +Z side and protrudes from the first surface 11u of the base 11c. Around the periphery of the base portion 121c, the heat transfer body 12c is hermetically bonded to the base 11c with a first bonding material 60. The submount 42 of the light-emitting unit 40 is bonded to the receiving surface of the base portion 121c with a second bonding material 61. The condenser lens 50c is bonded to the second connector 116 with a third bonding material 62. As in the first embodiment, the first bonding material 60, the second bonding material 61, and the third bonding material 62 are made of materials whose melting points decrease in the order of bonding.

[0029] 8B, the heat transfer body 12d has a small portion facing the bottom surface of the base 11c. The heat transfer body 12d may have an appropriate shape depending on the heat dissipation area from the heat transfer body 12d and the shape of the base on which the light emitting device 1d is mounted.

[0030] In another embodiment shown in Figure 8C, the bottom surface of the heat transfer body 12e may be located in approximately the same plane as the bottom surface of the base 11. The base 11e has a through hole 11te corresponding to the shape of the heat transfer body 12e. This allows pressure applied when connecting the light-emitting unit 40 and the connection electrode 111 with bonding wires W to be distributed to the bottom surface of the package, reducing damage to the package without taking special measures. This reduces the effort required in the manufacturing and assembly processes of the light-emitting device 1 and reduces the decrease in manufacturing yield.

[0031] 9A to 9C are diagrams illustrating other embodiments of the cross section taken along the cross-sectional line vi in ​​FIG. 6. In FIG. 9A, in the cross-sectional view of FIG. 8A, the package 10f has a protrusion 117 in a portion of the base 11f along the −X side of the pedestal 121c that is one step higher than the rest of the first surface 11u. In FIG. 9B, in the cross-sectional view of FIG. 8B, the package 10g has a protrusion 117 in a portion of the base 11f along the −X side of the pedestal 121c of the heat transfer body 12d that is one step higher than the rest of the first surface 11u. In FIG. 9C, in the cross-sectional view of FIG. 8C, the package 10h has a protrusion 117 in a portion of the base 11h along the −X side of the pedestal 121e that is one step higher than the rest of the first surface 11u.

[0032] The connection electrode 111 is located on the upper surface of the protrusion 117, and is close to the position of the connection electrode 111 in the Z direction of the light-emitting unit 40. The connection electrode 111 may be connected to the wiring layer 114 by multiple stages of via conductors 113. In this structure, the bonding wire W between the light-emitting unit 40 and the connection electrode 111 is short, and the connection positions are close at approximately the same height. Therefore, breaks and short circuits in the bonding wire W are reduced, enabling more stable light-emitting operation.

[0033] 10A to 10C are diagrams showing other embodiments of the cross section taken along the cross-sectional line ii in FIG. 2. In FIG. 10A, in the cross section of FIG. 4A, the package 10i has the connection electrodes 111 and the external electrodes 115 connected by wiring 114i extending on the first surface 11u of the base 11i. In FIG. 10B, in the cross section of FIG. 4B, the package 10j has the connection electrodes 111 and the external electrodes 115 connected by wiring 114i extending on the first surface 11u of the base 11i. In FIG. 10C, in the cross section of FIG. 4C, the package 10k has the connection electrodes 111 and the external electrodes 115 connected by wiring 114i extending on the first surface 11u of the base 11k.

[0034] In these packages 10i to 10k, the wiring 114i and the first connector 112 intersect on the bases 11i and 11k. Therefore, an insulating layer 118 is located between the wiring 114i and the first connector 112 at the intersection. Accordingly, the bases 11i and 11k may not have via conductors 113 and wiring layers 114. This simplifies the structure of the packages 10i to 10k. The insulating layer 118 does not adversely affect the sealing of the internal space formed by bonding the packages 10i to 10k to the lid 30. Therefore, the insulating layer 118 may be made of ceramic, such as alumina. In other words, the insulating layer 118 may be made of the same material as the bases 11i and 11k.

[0035] 11A and 11B are diagrams illustrating another embodiment of a cross section taken along the cross-sectional line ii in FIG. 2. As shown in FIG. 11A , the wiring conductor does not need to connect the connection electrode 111 on the first surface 11u to the external electrode 115. In one embodiment, the external electrode 115 may be located on the bottom surface of the base 11l in the package 10l. The wiring conductor includes a via conductor 113 that connects the wiring layer 114 to the first surface 11u and a via conductor 113 that connects the wiring layer 114 to the bottom surface of the base 11l. Even with this structure, the wiring conductor can properly electrically connect electrodes located on surfaces inside and outside the mounting area of ​​the base 11.

[0036] As shown in FIG. 11B , the heat transfer body 12m of the package 10m may have the -X side of the base 121m inclined relative to the first surface 11u. If the planar size of the top surface of the base 121m is larger than the planar size of the light-emitting unit 40, the bonding wire connecting the light-emitting unit 40 and the connection electrode 111 is likely to come into contact with the corner of the base 121m. By rounding off the corner of the base 121m that overlaps with the bonding wire in planar view, the possibility of contact with the base 121m is reduced even if the bonding wire is short. Note that the inclined surface of the base 121m does not have to be a flat surface with a constant inclination angle. The inclined surface may also be a curved surface with a variable inclination angle.

[0037] 12A and 12B are perspective views of another example of the light emitting device 1 with the cover removed. In the light emitting device 1 shown in Fig. 12A, two optical elements 41 are mounted on a submount 42. In the light emitting device 1 shown in Fig. 12B, an optical element 41 is mounted on each of two submounts 42 arranged side by side on a base 121. The number of optical elements 41 per light emitting device 1 does not have to be one, as long as a common condenser lens 50 is used for the number of optical elements 41.

[0038] As described above, the packages 10 to 10k, which are packages for mounting optical elements according to this embodiment, include a base 11, a heat transfer body 12, and via conductors 113 and a wiring layer 114 as wiring conductors. The base 11 has a first surface 11u on which a lid 30 can be mounted, and a through-hole 11t that penetrates between the first surface 11u and the surface opposite the first surface 11u. The heat transfer body 12 has a higher thermal conductivity than the base 11 and has a base portion 121 that penetrates the through-hole 11t and protrudes from the first surface 11u. One optical element 41 can be mounted on the base portion 121. The wiring conductor extends across the inside and outside of the mounting area of ​​the lid 30, and the connection electrodes 111 and external electrodes 115 at both ends are located on the first surface 11u. The first surface 11u or the base portion 121 of the base 11 includes a fixing surface on which at least one condenser lens 50 can be fixed. A ring-shaped first bonding material 60 is continuously positioned between the base 11 and the heat conductor 12, and the base 11 and the heat conductor 12 are hermetically bonded by the first bonding material 60. The packages 10-10k can reliably seal the optical element 41. Furthermore, heat generated by the optical element 41 during light emission can be quickly dissipated from the heat conductor 12, reducing deterioration of the optical element 41 due to high temperatures. Furthermore, because each light-emitting unit 40 is individually sealed within the package 10-10k, even if a problem such as a failure occurs in one of the optical elements 41 during or after sealing, the impact is minimal. In particular, problems during inspection or aging after sealing do not affect the entire light-emitting module 100, reducing a decrease in yield during manufacturing and inspection. Furthermore, because the laser diode is sealed together with at least one focusing lens 50, light is quickly focused and emitted with little diffusion. Furthermore, in a structure in which a signal connection pin is prepared separately from the base 11 and penetrates the base 11, after a through-hole is formed in the base 11, it is necessary to refill it to maintain airtightness. Therefore, this structure requires a lot of work to maintain airtightness. In addition, the refilling material is likely to hinder heat dissipation. In other words, the present disclosure can appropriately maintain stable operation and heat dissipation according to airtightness.

[0039] The first bonding material 60 may also be a brazing material. The base 11 and the heat transfer body 12 of each package 10 to 10k are bonded together first, and then the light-emitting unit 40, the condenser lens 50, and the lid 30 are bonded together. Therefore, by using a brazing material with a high melting point temperature for the first bonding material 60, it is possible to reduce the occurrence of problems such as the first bonding material 60 melting during subsequent heating, causing a break in airtightness or a shift in relative position.

[0040] The wiring conductor may have a wiring layer 114 that passes through the inside of the base 11 and connects the inside and outside of the mounting area of ​​the lid 30. By passing the wiring through the inside of the base 11, the joint between the base 11 and the lid 30 is not affected, and appropriate airtightness can be obtained more easily.

[0041] Furthermore, the wiring conductor and the base 11 may each contain inorganic particles of the same component that is different from the main component of the base 11. When the base 11 is in contact with and bonded to the wiring conductor, these inorganic particles bond together, thereby achieving higher bonding strength. Therefore, the packages 10 to 10k can maintain appropriate airtightness.

[0042] Furthermore, a ring-shaped first connector 112 may be located at the portion of the first surface 11u that is joined to the lid 30. When direct joining is difficult due to differences in the materials between the base 11 and the lid 30, a stronger joining may be achieved via the first connector 112.

[0043] Furthermore, the first bonding material 60, the first connector 112, and the base 11 may each contain inorganic particles of the same component as the main component of the base 11. This increases the bonding strength between the base 11 and the first connector 112 and improves the airtightness of the internal space.

[0044] Furthermore, in the packages 10c to 10h, in a plan view seen from above the first surface 11u, the second connector 116 to which the condenser lens 50c is fixed may be located between the base 121 of the first surface 11u and the first connector 112. The condenser lens 50c does not have to be directly fixed to the base 121. It is sufficient that an appropriate fixing range is ensured. Furthermore, if the condenser lens 50c is larger than the base 121c, the condenser lens 50c may be fixed more stably by fixing the underside of the condenser lens 50c to the first surface 11u rather than fixing the side of the condenser lens 50c to the side of the base 121c.

[0045] Furthermore, the heat transfer body 12 may include a portion located outside the range of the through-hole 11t in a plan view seen from above the first surface 11u. When the heat transfer body 12 extends beyond the range of the through-hole 11t, the heat received from the optical element 41 can be dissipated more efficiently.

[0046] Furthermore, the packages 10 to 10k may be provided with lids 30 that seal the space above the first surface 11u, including the area occupied by the condenser lenses 50, 50c and optical element 41 connected to the first surface 11u or the base 121. By handling the lids 30 corresponding to the packages 10 to 10k as a set, it becomes possible to more appropriately seal the internal spaces.

[0047] The light-emitting device 1 of this embodiment includes the above-described packages 10 to 10k, an optical element 41, and at least one condenser lens 50, 50c. This light-emitting device can properly seal each optical element 41, reducing its deterioration. Furthermore, because there are fewer components that are discarded due to a malfunction of the optical element 41, etc., a decrease in yield can be reduced.

[0048] The above embodiment is merely an example, and various modifications are possible. For example, although the light-emitting unit 40 is described as being a CoS in the above, this is not limiting. The optical element 41 may be directly fixed to the base 121.

[0049] The above-described combination of the first bonding material 60, the second bonding material 61, and the third bonding material 62 is an example. Other combinations of bonding materials may be used as long as the temperature relationship of the melting points is appropriate.

[0050] The lid 30 may also be bonded directly to the base 11 with a bonding material without using the first connector 112 .

[0051] In the above description, the first bonding material 60 and the first connecting body 112 contain inorganic particles of the same composition as the base 11, but they do not necessarily need to contain inorganic particles of the same composition.

[0052] The shape of the heat transfer body 12 is not limited to the above. The shape of the base portion 121, the degree of expansion of the bottom surface, and the fitting shape with the through-hole 11t may be determined as appropriate.

[0053] Furthermore, in the above description, the light-emitting module 100 has been described in which the collecting lens 50, which is an FAC lens, or the collecting lens 50c, which is an FAC / SAC lens, is located within the mounting range, and in the former case, the collecting lens 2, which is an SAC lens, is located outside the light-emitting device 1, but this is not limiting. Both the collecting lens 50 and the collecting lens 2 may be located within the mounting range. Alternatively, the SAC lens may be located within the mounting range, and the FAC lens may be located outside the mounting range.

[0054] Furthermore, the light-emitting unit 40 does not have to be located on the top surface of the base 121. Depending on the shape of the base 121, the light-emitting unit 40 may be fixed to the side surface of the base 121 or to the middle step of a staircase structure.

[0055] The lid 30 may also be included in the package as a dedicated item for the packages 10 to 10k.

[0056] Furthermore, the positional relationships among the plurality of light emitting devices 1, the condenser lens 2, the mirror 3, etc. in the light emitting module 100 may be determined as appropriate. In this case, the wavelengths of the light emitted by the plurality of light emitting devices 1 do not have to be the same. The light emitting module 100 may output light of a color that is a mixture of light of multiple wavelengths.

[0057] Although the optical element 41 has been described above as a light-emitting element, it is not limited to this and may be any other optical element such as a light-receiving element as long as it requires a condenser lens.

[0058] Furthermore, the packages 10-10m may be used in devices other than the light-emitting device 1, such as optical transceivers, which are devices that transmit and receive data using optical signals. More specifically, they may be used in transmitter modules, which are components of optical transceivers. In this case, the optical element 41 may be an InP laser element. In the packages 10-10m, the optical element 41 is located in a sealed space. Therefore, even if an InP laser element, which is susceptible to oxidation, is used as the optical element 41, deterioration or shortening of the InP laser's lifespan can be reduced. Furthermore, the specific details of the structure, configuration, materials, size, and the like shown in the above embodiments may be modified as appropriate without departing from the spirit of this disclosure. The scope of the present invention includes the scope of the invention set forth in the claims and their equivalents.

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

[0060] REFERENCE SIGNS LIST 1, 1c, 1d Light emitting device 2 Collecting lens 3 Mirror 4 Collecting lens 5 Base 10 to 10m Package 11, 11c, 11e, 11f, 11h, 11i, 11k, 11l Base 11t, 11tb, 11tc, 11te Through hole 11u First surface 110, 110b Substrate member 111 Connection electrode 112 First connector 113 Via conductor 114 Wiring layer 114i Wiring 115 External electrode 116 Second connector 117 Protrusion 118 Insulating layer 12, 12a to 12e, 12m Heat conductor 121, 121c, 121e, 121m Base 121s Side surface 121t Top surface 30 Lid 31 Light-transmitting member 32 Bonding surface 40 Light-emitting unit 41 Optical element 42 Submount 50, 50c Condenser lens 60 First bonding material 61 Second bonding material 62 Third bonding material 100 Light-emitting module W Bonding wire

Claims

1. An optical element mounting package comprising: a base having a first surface on which a lid can be mounted and a through-hole penetrating between the first surface and the surface opposite the first surface; a heat transfer body having a thermal conductivity higher than that of the base and having a platform portion that passes through the through-hole and protrudes from the first surface, on which an optical element can be mounted; and a wiring conductor extending across the inside and outside of the mounting area of ​​the lid, with both ends of the electrodes located on the surface of the base; wherein the first surface or the platform portion of the base includes a fixing surface on which at least one focusing lens can be fixed; and a ring-shaped first bonding material is continuously located between the base and the heat transfer body, and the base and the heat transfer body are hermetically bonded by the first bonding material.

2. The optical element package according to claim 1, wherein the first bonding material is a brazing material.

3. The optical element package according to claim 1 or 2, wherein the wiring conductor passes through the inside of the base and connects the inside and outside of the mounting area of ​​the lid.

4. An optical element package according to any one of claims 1 to 3, wherein the wiring conductor and the base each contain inorganic particles of the same component different from the main component of the base.

5. An optical element package according to any one of claims 1 to 4, wherein a ring-shaped first connector is located at the portion of the first surface that is joined to the lid.

6. An optical element mounting package according to claim 5, wherein the first bonding material, the first connecting body and the base each contain inorganic particles of the same component but different from the main component of the base.

7. A package for mounting an optical element as described in claim 5 or 6, wherein, in a plan view from above the first surface, a second connector to which the focusing lens is fixed is located between the base portion of the first surface and the first connector.

8. A package for mounting an optical element as described in any one of claims 1 to 7, wherein the heat transfer body includes a portion located outside the range of the through hole when viewed in a plan view from above the first surface.

9. A package for mounting an optical element according to any one of claims 1 to 8, comprising a lid that seals the space on the first surface, including the area occupied by the focusing lens and the optical element connected to the first surface or the base.

10. A light emitting device comprising: the package for mounting an optical element according to claim 9; an optical element; and at least one condenser lens.

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