Substrate, package for housing element, and electronic device

Abstract

The present invention improves a heat dissipation property. This substrate comprises: an insulating substrate having a through-hole; a wiring conductor; and a metal member at least a part of which is positioned in the through-hole. The metal member has a main body portion positioned in the through-hole, and a protruding portion protruding from a first surface of the insulating substrate. The protruding portion has a first side surface that is orthogonal to the first surface and has an element mounting region on which an element is mounted.

Description

Substrate, element housing package and electronic device

[0001] The present disclosure relates to a substrate, a package for housing an element, and an electronic device.

[0002] As described in Patent Document 1, an example of a semiconductor package for optical communications is a CAN package, in which metal lead terminals are passed through openings in a metal plate, glass is used to provide airtightness and insulation, and a cap with a window is welded.

[0003] Japanese Patent Application Laid-Open No. 2008-270375

[0004] A substrate according to one aspect of the present disclosure comprises an insulating base having a first surface on which an element is arranged, a second surface opposite the first surface, and a through hole penetrating from the first surface to the second surface, a wiring conductor including a plurality of connection terminals located on the first surface and connected to the element, and a plurality of external terminals located on the outer surface of the insulating base and connected to a mounting substrate, and a metal member at least a portion of which is located within the through hole, wherein the metal member has a main body portion located within the through hole and a protrusion portion protruding from the first surface, the protrusion portion having an element mounting region for mounting the element and a first side surface perpendicular to the first surface.

[0005] A package for storing an element according to one aspect of the present disclosure includes the substrate and a lid with a window.

[0006] An electronic device according to one aspect of the present disclosure includes the above-described element housing package and an element.

[0007] FIG. 1 is a perspective view of an electronic device according to a first embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1 . FIG. 3 is a top view of a substrate according to the first embodiment of the present disclosure. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3 . FIG. 5 is a bottom view of a substrate according to the first embodiment of the present disclosure. FIG. 6 is a perspective view of a metal member according to the first embodiment of the present disclosure. FIG. 7 is a cross-sectional view taken along line VIII-VIII in FIG. 7 . FIG. 8 is a top view of a substrate according to the second embodiment of the present disclosure. FIG. 9 is a cross-sectional view taken along line X-X in FIG. 9 . FIG. 10 is a bottom view of a substrate according to the second embodiment of the present disclosure. FIG. 11 is a perspective view of a metal member and a cross-sectional view of an electronic device according to a third embodiment of the present disclosure. FIG. 12 is a perspective view of a metal member and a cross-sectional view of an electronic device according to a fourth embodiment of the present disclosure. FIG. 13 is a perspective view of a metal member and a cross-sectional view of an electronic device according to a fifth embodiment of the present disclosure. FIG. 14 is a perspective view of a metal member and a cross-sectional view of an electronic device according to a sixth embodiment of the present disclosure. FIG. 15 is a perspective view of a metal member and a cross-sectional view of an electronic device according to a seventh embodiment of the present disclosure. FIG. 16 is a perspective view of a metal member and a cross-sectional view of an electronic device according to an eighth embodiment of the present disclosure.

[0008] Optical semiconductor elements generate heat, which may reduce the reliability of electronic devices, and therefore, improvements in heat dissipation are desired.

[0009] According to one aspect of the present disclosure, it is possible to improve heat dissipation in a substrate, a package, and an electronic device on which an optical semiconductor element is mounted.

[0010] [Embodiment 1] A substrate, an element housing package, and an electronic device according to one embodiment of the present disclosure will be described in detail below with reference to the drawings. However, for the sake of convenience, the figures referenced below may show only the components necessary for explaining the embodiment in a simplified form. Therefore, the substrate, element housing package, and electronic device according to each embodiment may include any components not shown in the figures referenced. It should also be noted that the dimensions of the components in the figures do not faithfully represent the actual dimensions of the components or the dimensional ratios of each member.

[0011] The distinction between top and bottom in the following description is for convenience and does not limit the top and bottom when the substrate, element housing package, and electronic device are actually used. In this specification, the surface of the substrate and package on which the element is mounted is defined as the top surface. In the accompanying drawings, the X-Y plane is a plane parallel to the top or bottom surface of the substrate 10, and the Z axis is an axis perpendicular to the X-Y plane. The X-axis direction is defined as a direction perpendicular to the first side surface 421 of the metal member 4, which will be described later.

[0012] In this disclosure, the term "rectangular" does not necessarily mean a strict rectangular shape, but may include shapes that are visually recognizable as a rectangle overall, such as shapes with curved corners. In the drawings of this disclosure, cross-sectional areas are hatched and dots are applied to the exposed surfaces of the wiring conductors and metal films. Also, the bonding material that bonds each component is not shown.

[0013] An electronic device 900 according to a first embodiment will be described with reference to Fig. 1 to Fig. 6. Fig. 1 is a perspective view of the electronic device 900 according to the first embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a top view of a substrate 10 according to the first embodiment. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3. Fig. 5 is a bottom view of the substrate 10. Fig. 6 is a perspective view of a metal member 4 according to the first embodiment.

[0014] For ease of explanation, the outline of the metal member 4 when viewed through is shown by a dashed line in Fig. 1. The metal member 4 is omitted in Fig. 3. The metal member 4 and the wiring conductor 3 are omitted in Fig. 4. The metal member 4 is omitted in Fig. 5, but the outlines of the main body 41 (second portion 413) and the protrusion 42 are shown by dashed lines.

[0015] As shown in Figures 1 and 2, electronic device 900 includes package 100 and element 70. Package 100 is an example of an element storage package according to the present disclosure. Package 100 includes substrate 10 and lid 60. Lid 60 is an example of a windowed lid according to the present disclosure. Substrate 10 includes insulating base 2, wiring conductor 3, and metal member 4. Each part will be described in detail below.

[0016] The element 70 according to the present disclosure may be, for example, a light-emitting element such as an LED (Light Emitting Diode) or an LD (Laser Diode). More specifically, the element 70 may be an edge-emitting LD element. Alternatively, the element 70 may be a VCSEL (Vertical Cavity Surface Emitting Laser). In this case, the window of the lid 60 is provided on the sidewall, not on the top of the lid 60.

[0017] The package 100 is an element housing package for housing the element 70, and the electronic device 900 is a device in which the element 70 is mounted in the package 100. In addition to the element 70, the package 100 can also house electronic components such as a drive circuit, a capacitor, and a light receiving element.

[0018] The lid 60 has a cap shape (hat shape) and is provided at the top with a window 61 through which light from the element 70 passes. The lid 60 may be made of metal or ceramic. The opening of the window 61 is sealed with a transparent member 65 made of glass, resin, or the like that transmits light. The transparent member 65 may include an optical thin film such as an anti-reflection film.

[0019] The substrate 10 includes an insulating base 2, a wiring conductor 3, and a metal member 4. The insulating base 2 may include a base portion 20 and a frame portion 29. The base portion 20 may be a flat insulator having, for example, a rectangular shape in a plan view. The base portion 20 has a first surface 21 on the side where the element 70 is arranged, a second surface 22 located opposite the first surface 21, and a through-hole 23 that penetrates from the first surface 21 to the second surface 22.

[0020] As shown in FIG. 3 , a bonding region 212 to which the lid 60 is bonded is located on the first surface 21. The bonding region 212 may be an area that overlaps with the bonding surface of the lid 60 in a planar perspective view when the lid 60 is placed in an appropriate position. The bonding surface of the lid 60 and the bonding region 212 may be bonded using a bonding material such as brazing material, resin, or glass, thereby achieving an airtight seal. When the lid 60 and the base 20 are bonded using brazing material, a metal film for bonding may be provided in the bonding region 212. The metal film for bonding may be provided in an area slightly larger than the bonding region 212.

[0021] The frame 29 is positioned on the first surface 21 so as to surround the bonding area 212. The outer edge of the frame 29 may be shaped to overlap the outer edge of the base 20 in a plan view. The inner edge of the frame 29 may be shaped to overlap the outer edge of the bonding area 212 or may be slightly larger than the bonding area 212 in a plan view. Since the frame 29 is positioned so as to surround the bonding area 212, the lid 60 can be positioned on the substrate 10 with high positional accuracy.

[0022] 3, the frame 29 may have at least one notch 51 on the bonding region 212 side. By having the frame 29 have the notch 51 on the bonding region 212 side, in other words, on the inside, it is possible to reduce the possibility that the bonding material bonding the lid 60 and the base 20 will protrude onto the upper surface of the frame 29.

[0023] The insulating base 2 may be made of ceramics such as an aluminum oxide sintered body (alumina ceramics), an aluminum nitride sintered body, a mullite sintered body, or a glass ceramic sintered body. The insulating base 2 may include a plurality of laminated insulating layers, as shown in Fig. 4 . Alternatively, the base 20 and frame 29 of the insulating base 2 may be integrally formed. Fig. 4 shows an example in which the base 20 is made of insulating layers 201, 202, 203, and 204, and the frame 29 is made of insulating layer 209.

[0024] The wiring conductor 3 includes a plurality of connection terminals 31 located on the first surface 21 and connected to the element 70, and a plurality of external terminals 32 located on the outer surface of the insulating base 2 and connected to a mounting substrate. The wiring conductor 3 may further include an internal wiring layer and a through conductor as an internal conductor located inside the insulating base 2. The external terminals 32 located on the outer surface of the insulating base 2 enable a surface-mountable electronic device to be realized. In the substrate 10 according to the first embodiment, the external terminals 32 are located on the second surface 22. The external terminals 32 may extend from the second surface 22 to a side surface connecting the first surface 21 and the second surface 22. Specifically, the external terminals 32 may extend to the side surface by castellations. The castellations may be formed at corners between side surfaces, as shown in FIGS. 1, 3, and 5. Since the external terminals 32 extend from the second surface 22 to the side surfaces and / or corners, the bonding material used to bond the external terminals 32 to the mounting substrate can creep up along the external terminals 32 and form fillets, thereby improving the bonding strength between the substrate 10 and the mounting substrate.

[0025] The substrate 10 has a through-hole 23 that penetrates from the first surface 21 to the second surface 22, and a metal member 4 with at least a portion located within the through-hole 23. The element 70 can be attached to the side surface of the metal member 4. The element 70 may be attached directly to the metal member 4 as shown in FIG. 8, or a submount 80 may be located between the element 70 and the metal member 4 as shown in FIG. 2. The submount 80 may be made of a material with good thermal conductivity, such as aluminum nitride.

[0026] The metal member 4 is made of a material with high thermal conductivity, such as Cu, a Cu-W alloy, an Fe-Ni alloy, or an Fe-Ni-Co alloy, and dissipates heat generated by the element 70 to the mounting substrate. Cu has extremely high thermal conductivity and excellent heat dissipation properties. Cu-W alloy, Fe-Ni alloy, and Fe-Ni-Co alloy have high thermal conductivity and a small difference in thermal expansion coefficient with ceramics. When the insulating base 2 is made of ceramics, selecting these metals can reduce stress caused by the difference in thermal expansion.

[0027] The metal member 4 has a main body 41 located within the through-hole 23 and a protruding portion 42 protruding from the first surface 21. As shown in FIG. 6 , the protruding portion 42 has a first side surface 421. The first side surface 421 has an element mounting region R on which the element 70 is mounted, and is a surface perpendicular to the first surface 21. The first side surface 421 may be a surface parallel to any side surface of the insulating base 2. Since the element 70 is attached to the metal member 4 made of a series of metals, heat generated from the element 70 can be efficiently dissipated to the mounting substrate. This makes it possible to realize a substrate 10, a package 100, and an electronic device 900 with excellent heat dissipation properties.

[0028] The metal member 4 and the wall surface of the through hole 23 are joined using a joining material such as a brazing material or glass. When joining using a brazing material, a metal film for joining may be provided on the wall surface of the through hole 23.

[0029] In the metal member 4, the area of ​​the end portion of the main body 41 on the second surface 22 side may be larger than the area of ​​a cross section of the protruding portion 42 parallel to the first surface 21. More specifically, in the metal member 4, the area of ​​the end portion of the main body 41 on the second surface 22 side may be larger than the area of ​​a cross section of the element mounting region R parallel to the first surface 21. When the main body 41 of the metal member 4 has a larger cross-sectional area than the protruding portion 42, heat from the element 70 is transferred while diffusing in the lateral direction (a direction parallel to the X-Y plane) as it travels in the direction of the second surface 22, thereby improving heat dissipation.

[0030] For example, as shown in FIGS. 2 and 6 , the protrusion 42 may have a columnar portion with a substantially uniform cross-sectional area parallel to the first surface 21, and the main body 41 may have an enlarged portion whose cross-section parallel to the first surface 21 expands in the direction from the first surface 21 to the second surface 22. For example, as shown in FIGS. 2 and 6 , the entire protrusion 42 may have a columnar shape. The main body 41 may have a shape including a first portion 412 that is an extension of the protrusion 42 and a block-shaped second portion 413 with a larger cross-sectional area than the first portion 412. In this case, the transition from the first portion 412 to the second portion 413 corresponds to the enlarged portion. The metal member 4 may have a columnar shape with a stepped side surface, and the main body 41 may have an enlarged portion. The cross-sectional shape of the main body 41 and the protrusion 42 parallel to the first surface 21 may be rectangular, as shown in FIG. 1 , but is not particularly limited as long as the shape includes the first side surface 421.

[0031] Because the second surface 22 side has a block shape with a large cross-sectional area, heat from the element 70 is transferred while diffusing laterally as it travels toward the second surface 22, thereby improving heat dissipation. In the examples shown in FIGS. 2 and 6 , the thickness of the second portion 413 is smaller than the thickness of the insulating base 2, but the shape of the metal member 4 is not limited to this example, and the thickness of the second portion 413 may be equal to or greater than the thickness of the insulating base 2. In other words, the metal member 4 may have a mounting portion having an element mounting region R and a first side surface 421 perpendicular to the first surface 21, and a thermal diffusion portion whose cross-sectional area parallel to the first surface 21 is larger than that of the mounting portion. The mounting portion may be located protruding from the first surface 21, and at least a portion of the thermal diffusion portion may be located within the through-hole 23.

[0032] When the main body portion 41 has the enlarged portion described above, the insulating base 2 may have a base protrusion 24 that protrudes toward the inside of the through hole 23. The base protrusion 24 is a portion that overlaps with the main body portion 41 in a planar perspective view. The base protrusion 24 limits movement of the second portion 413 of the main body portion 41 toward the first surface, and can accurately determine the position of the metal member 4 in the Z-axis direction.

[0033] In the examples shown in FIGS. 2 and 6 , the thickness of the second portion 413 of the metal member 4 is smaller than the thickness of the insulating base 2, and the metal member 4 has a stepped columnar shape. The base protrusion 24 overlaps the second portion 413 in a planar perspective view. More specifically, as shown in FIG. 5 , the base protrusion 24 vertically overlaps the second portion 413, which protrudes from the first portion 412 in a planar view. By joining the lower surface of the base protrusion 24 and the upper surface of the second portion 413 with a joining material, the joining strength between the metal member 4 and the insulating base 2 is improved. Having an enlarged portion at the top of the main body 41 where the cross-sectional area suddenly expands, as in the case of the metal member 4, increases the cross-sectional area, thereby improving heat dissipation. Furthermore, the larger joining surface area with the lower surface of the base protrusion 24 also improves joining strength. Furthermore, by providing the base protrusion 24 , it is possible to reduce the possibility that the bonding material that bonds the metal member 4 and the insulating base 2 will creep up and protrude onto the first surface 21 .

[0034] The base protrusion 24 is located on the first surface 21 side of the insulating base 2. For example, a case where the insulating base 2 is a laminate of multiple insulating layers will be described with reference to FIG. 4 . In the example shown in FIG. 4 , the base 20 is a laminate in which insulating layer 201, insulating layer 202, insulating layer 203, and insulating layer 204 are stacked in this order from the first surface side. The insulating layers 201 and 202 each have a through hole 231 and a through hole 232 in which a first portion 412 of the metal member 4 is located. The insulating layers 203 and 204 each have a through hole 233 and a through hole 234 in which a second portion 413 of the metal member 4 is located. The through holes 231, 232, 233, and 234 overlap and communicate with each other to form the through hole 23 that penetrates the insulating base 2 from the first surface 21 to the second surface 22.

[0035] The inner dimensions of through holes 231 and 232 are both smaller than the inner dimensions of through holes 233 and 234. In planar perspective, the portions of insulating layers 201 and 202 that are located inside the outer edge of through hole 233 can be defined as base protrusions 24.

[0036] When the insulating base 2 has the base protrusion 24, the bonding metal film provided on the wall surface of the through hole 23 may be provided only on the wall surfaces of the through holes 233 and 234 and on the lower surface (lower surface of the base protrusion 24) of the insulating layer 202. This further reduces the possibility that the bonding material will creep up and protrude onto the first surface 21.

[0037] Furthermore, the inner dimension of the through hole 233 may be slightly larger than the inner dimension of the through hole 234. With this configuration, a pool of bonding material can be formed, which improves the bonding strength and further reduces the possibility of the bonding material spilling onto the first surface 21 and the second surface 22.

[0038] As shown in FIGS. 2 to 4 , the insulating base 2 may have a recess 25 in the first surface 21 that communicates with the through hole 23. The recess 25 is located on the first side surface 421 side of the metal member 4 around the through hole 23. The recess 25 is located below the element 70 when the element 70 is mounted on the substrate 10. With this configuration, even if the bonding material creeps up from the through hole 23 to the first surface 21, it spreads into the recess 25, reducing the possibility of the bonding material creeping up to the first side surface 421 of the metal member 4. This reduces the possibility of the element 70 mounted on the first side surface 421 being tilted by the bonding material. A metal film may be provided on the inner surface of the recess 25 to facilitate wetting and spreading of the bonding material.

[0039] In the substrate 10, the metal member 4 may have a bilaterally symmetrical shape in a cross section perpendicular to the first surface 21 and the first side surface 421. In this case, as shown in FIG. 5 , the distance D1 from the first side surface 421 to the outer edge of the insulating base 2 in the direction perpendicular to the first side surface 421 is greater than the distance D2 from the second side surface 422 located opposite the first side surface 421 to the outer edge of the insulating base 2. More specifically, the distance D1 from the first side surface 421 to the first outer edge located outside the first side surface 421 is greater than the distance D2 from the second side surface 422 to the second outer edge located outside the second side surface 422. The direction from the first side surface 421 toward the inside (interior) of the metal member 4 is defined as the inward direction, and the opposite direction is defined as the outward direction. The first outer edge can also be considered to be the outer edge portion of the outer edge of the insulating base 2 located outward from the first side surface 421. The direction from the second side surface 423 toward the inside (interior) of the metal member 4 is referred to as the inward direction, and the opposite direction is referred to as the outward direction. The second outer edge can also be said to be the outer edge portion of the outer edge of the insulating base 2 that is located outward from the second side surface 422. In other words, the through hole 23 and the protrusion 42 of the metal member 4 are positioned offset from the center of the substrate 10.

[0040] This configuration allows the light-emitting portion of the edge-emitting element to be positioned near the center of the substrate 10. Furthermore, because the metal member 4 has a bilaterally symmetrical shape, in other words, the protrusion 42 and the first portion 412 are located at the center of the second portion 413 in a plan view, heat from the element 70 is spread evenly in the lateral direction, thereby improving heat dissipation efficiency. Furthermore, because the through-hole 23 is located off-center, a wide area can be secured on the second surface 22, thereby improving the degree of freedom in the layout of the external terminals 32.

[0041] Furthermore, in a planar perspective view, the total area of ​​the external terminals 321 located outside a line L1 extending from a virtual line corresponding to the first side surface 421 may be larger than the total area of ​​the external terminals 322 located outside a line L2 extending from a virtual line corresponding to the second side surface 422. The external terminals 32 are bonded to the mounting substrate via a conductive bonding material or the like. Furthermore, in order to improve the bonding strength between the mounting substrate and the substrate 10, the metal member 4 may also be bonded to the mounting substrate via a bonding material. In the substrate 10, the metal member 4 may be a ground conductor. In this case, the portion of the metal member 4 exposed on the second surface 22 may serve as an external terminal of the ground potential for the substrate 10.

[0042] The total area of ​​the external terminals 32 located outside the first side surface 421 is larger than the total area of ​​the external terminals 32 located outside the second side surface 422, so that the bonding material can be arranged in a well-balanced manner. This reduces the possibility that the substrate 10 will be mounted tilted when mounted on a mounting board, and thus reduces the possibility that the optical axis will be tilted.

[0043] The wiring conductor 3, the metal film for joining the lid provided in the joining region 212, and the metal film for joining the metal member provided in the through hole 23 may be, for example, a metal powder metallization containing tungsten (W), molybdenum (Mo), manganese (Mn), silver (Ag), or copper (Cu) as its components.

[0044] The exposed surfaces of the wiring conductor 3 and the metal film may be coated with a nickel plating layer / gold plating layer as a metal plating layer by plating methods such as electrolytic plating or electroless plating. This can effectively reduce corrosion of the wiring conductor and the like. It can also improve the wettability of the bonding material, thereby improving bonding strength. The metal plating layer is not limited to a nickel plating layer / gold plating layer, but may be other metal plating layers including a nickel plating layer / palladium plating layer / gold plating layer, etc.

[0045] (Substrate Manufacturing Method) When the insulating base 2 includes multiple insulating layers, such as those made of aluminum oxide sintered bodies, as in the example shown in FIG. 4 , the insulating base 2 is manufactured as follows. A slurry is produced by adding an appropriate organic binder and solvent to raw material powders such as aluminum oxide and silicon oxide. This slurry is formed into sheets by a doctor blade method, a calendar roll method, or the like, to produce ceramic green sheets for the insulating layers. The ceramic green sheets for the insulating layers are then punched appropriately to form through-holes 23, recesses 25, frame portions 29, and base protrusions 24. A laminate is then produced by stacking multiple ceramic green sheets for the insulating layers. The laminate is then fired at a high temperature (approximately 1300 to 1600°C) to produce the insulating base 2.

[0046] When the wiring conductor 3 is, for example, a tungsten metallized layer, it can be formed as follows. Wiring layers such as the connection terminals 31, external terminals 32, and internal wiring layers of the internal conductors are formed by printing a metal paste, prepared by mixing tungsten powder with an organic solvent and an organic binder, at predetermined positions on the ceramic green sheets for the insulating layer using a method such as screen printing, and then firing the laminate. The through conductors of the internal conductors are formed by forming holes for the through conductors at predetermined positions on the ceramic green sheets for the insulating layer and filling the holes with metal paste. The metal film for bonding provided on the wall surfaces of the through holes 23 is formed by forming holes for the through holes 23 at predetermined positions on the ceramic green sheets for the insulating layer and applying metal paste to the inner surfaces of the holes. Metal films extending in the X-Y plane within the through holes, such as the base protrusions 24, can be formed in the same manner as the wiring layers described above.

[0047] [Embodiment 2] Another embodiment of the present disclosure will be described below. For convenience of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0048] An electronic device 900A according to a second embodiment will be described with reference to FIGS. 7 to 11. FIG. 7 is a perspective view of the electronic device 900A according to the second embodiment. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. FIG. 9 is a top view of a substrate 10A according to the second embodiment. FIG. 10 is a cross-sectional view taken along line XX in FIG. 9. FIG. 11 is a bottom view of the substrate 10A. The metal member 4A is omitted from FIGS. 9, 10, and 11.

[0049] The electronic device 900A includes a package 100A and an element 70. The package 100A is an example of an element storage package according to the present disclosure. The package 100A includes a substrate 10A and a lid 60. The substrate 10A includes an insulating base 2A, a wiring conductor 3A, and a metal member 4A.

[0050] In the substrate 10A according to the second embodiment, the plurality of external terminals 32A are located on one of the side surfaces connecting the first surface 21 and the second surface 22. As shown in Fig. 7, the external terminals 32A located on the side surface of the substrate 10A may be formed by castellation. Alternatively, the external terminals 32A located on the side surface of the substrate 10A may be formed by side surface printing. By having the external terminals 32A located on the side surface, the side surface of the electronic device 900A can be used as a mounting surface.

[0051] In the case of side mounting, the surface of the metal member 4A on the second surface 22A side is exposed to the outside, and heat is dissipated from the exposed surface. This allows for the realization of a substrate 10A, a package 100A, and an electronic device 900A with excellent heat dissipation properties. Furthermore, by side mounting the electronic device 900A, the radiation direction of the element 70 can be made horizontal to the substrate surface. When the metal member 4A is used as a ground conductor, it may be electrically connected to an external terminal 32A located on the side surface via a bonding material, a bonding metal film, and internal wiring (not shown).

[0052] 9 and 11, the external terminals 32A may extend from the side surfaces of the substrate 10A to the first surface 21A, or may extend to both the first surface 21A and the second surface 22A. When the insulating base 2A has a frame 29, the external terminals 32A may extend from the side surfaces of the substrate 10A to the top surface of the frame 29, or may extend to both the top surface of the frame 29 and the second surface 22A. With this configuration, as shown in FIG. 8, the bonding material B may creep up along the external terminals 32 when bonding to the mounting substrate, forming a fillet. This improves the bonding strength between the substrate 10A and the mounting substrate.

[0053] In a plan view of the metal member 4A seen from the positive direction of the Z axis, the protrusion 42 and the first portion 412 are positioned offset from the center of the second portion 413. With this configuration, when the light-emitting portion of the element 70 is positioned near the center of the substrate 10A, the second portion 413 of the metal member 4A can be positioned near the center of the substrate 10A.

[0054] 10 , insulating base 2A may be a laminated body in which insulating layer 201A, insulating layer 202A, insulating layer 203A, and insulating layer 204A are laminated in this order from the first surface side. Insulating layer 201A and insulating layer 202A have through holes 231A and 232A, respectively, which become through hole 23A and in which first portion 412 of metal member 4A is located. Insulating layer 203A and insulating layer 204A have through holes 233A and 234A, respectively, which become through hole 23A and in which second portion 413 of metal member 4A is located.

[0055] The inner dimensions of through hole 233A and through hole 234A may be one size larger than the other. Similarly, the inner dimensions of through hole 231A and through hole 232A may be one size larger than the other. By configuring the inner dimensions of adjacent insulating layers having approximately the same inner dimensions in this manner, it is possible to reduce the possibility that the inner dimensions of the through holes will become smaller even if misalignment occurs when the insulating layers are stacked.

[0056] 12 is a perspective view of a metal member 4B according to a third embodiment and a cross-sectional view of an electronic device 900B including the metal member 4B. The cross-sectional view of the electronic device 900B corresponds to FIG. 2 in the first embodiment.

[0057] The metal member 4B has a main body 41 and a protruding portion 42. The protruding portion 42 has an element mounting region R and a first side surface 421 that is perpendicular to the first surface 21. As in the example shown in FIG. 12 , the main body 41 and the protruding portion 42 of the metal member 4B may have the same cross-sectional area parallel to the first surface 21. In other words, the metal member 4B may have a columnar shape with a constant cross-sectional area from the top to the bottom. The metal member 4B and the inner wall surface of the through hole 23B can be joined using a joining material such as brazing material or glass.

[0058] The electronic device 900B has excellent heat dissipation properties because the device 70 and the external circuit board can be thermally connected directly via a metal member 4B made of highly thermally conductive material such as copper. Furthermore, because the width (length in the Y direction) of the metal member 4B is larger than that of the device 70 (or the submount 80), heat is diffused and conducted in the Y direction. Furthermore, by increasing the thickness (length in the X direction) of the metal member 4B to increase thermal diffusion in the X direction, heat dissipation can be further improved. The metal member 4B has a simple shape and is compact, which also contributes to reducing costs and weight.

[0059] Fourth Embodiment FIG. 13 is a perspective view of a metal member 4C according to a fourth embodiment and a cross-sectional view of an electronic device 900C including the metal member 4C.

[0060] 13 , the metal member 4C may have a columnar shape with a step on the side, and may have an enlarged portion where the cross-sectional area expands at the boundary between the main body portion 41 and the protruding portion 42. More specifically, the metal member 4C may have a columnar protruding portion 42 with a constant cross-sectional area and a block-shaped main body portion 41 with a constant cross-sectional area, with the cross-sectional area of ​​the main body portion 41 being larger than that of the protruding portion 42. The metal member 4C and the inner wall surface of the through hole 23C may be joined using a joining material such as brazing material or glass.

[0061] Fifth Embodiment FIG. 14 is a perspective view of a metal member 4D according to a fifth embodiment and a cross-sectional view of an electronic device 900D including the metal member 4D.

[0062] As shown in the example of FIG. 14 , the protrusion 42 may have a columnar portion having a substantially uniform cross-sectional area parallel to the first surface 21 and an enlarged portion whose cross-section parallel to the first surface 21 expands in the direction from the first surface 21 to the second surface 22. Specifically, the metal member 4D may have an enlarged portion at the bottom of the protrusion 42. The enlarged portion may have a shape having an inclined surface whose cross-sectional area continuously expands, as shown in the example of FIG. 14 , or may have a stepped shape. Since the metal member 4D has an enlarged portion and is shaped like a block with a larger cross-sectional area on the second surface 22 side, heat from the element 70 is transferred while diffusing laterally as it travels toward the second surface 22, thereby improving heat dissipation.

[0063] The metal member 4D of the electronic device 900D has an enlarged portion on the protrusion 42, i.e., the enlarged portion with an enlarged cross-sectional area is located near the element 70 (or the mounting region R), and therefore has superior heat dissipation properties. The lower end of the element mounting region R may also be formed as the enlarged portion. This makes it easier to position the element 70 (or the submount 80).

[0064] Sixth Embodiment FIG. 15 is a perspective view of a metal member 4E according to a sixth embodiment and a cross-sectional view of an electronic device 900E including the metal member 4E.

[0065] 15 , the protrusion 42 may have a columnar portion with a substantially uniform area of ​​a cross section parallel to the first surface 21, and the main body 41 may have an enlarged portion in which the cross section parallel to the first surface 21 expands in the direction from the first surface 21 toward the second surface 22. Specifically, the metal member 4E may have an enlarged portion on an upper portion of the main body 41. The enlarged portion may have a stepped shape as in the example shown in FIG. 15 , or may have a shape with a continuously expanding inclined surface.

[0066] Since the metal member 4E has an enlarged portion and the second surface 22 side is in the shape of a block with a large cross-sectional area, the heat from the element 70 is diffused laterally as it travels in the direction of the second surface 22, thereby improving heat dissipation.

[0067] Furthermore, when the main body 41 has the enlarged portion described above, the insulating base 2E may have a base protrusion 24. The bonding strength between the metal member 4E and the insulating base 2E is improved by having the main body 41 have the enlarged portion and being bonded to the base protrusion 24. Furthermore, by having the base protrusion 24, the possibility that the bonding material bonding the metal member 4E and the insulating base 2E will creep up and protrude onto the first surface 21 can be reduced.

[0068] Compared to the metal member 4 of embodiment 1 (see Figures 2 and 6), the metal member 4E has an enlarged portion closer to the element 70 (or the mounting region R), so that heat is diffused closer to the element 70 and transferred through a large heat conduction path (main body portion 41), thereby improving heat dissipation.

[0069] Seventh Embodiment FIG. 16 is a perspective view of a metal member 4F according to a seventh embodiment and a cross-sectional view of an electronic device 900F including the metal member 4F.

[0070] As shown in the example of FIG. 16 , the protrusion 42 may have a columnar portion with a substantially uniform cross-sectional area parallel to the first surface 21, and the main body 41 may have an enlarged portion whose cross-section parallel to the first surface 21 expands in the direction from the first surface 21 to the second surface 22. Specifically, the metal member 4F may have a shape in which the main body 41 gradually widens from the first surface 21 toward the second surface 22. In this case, the through hole 23 of the insulating base 2F may have a shape that widens in stages from the first surface 21 toward the second surface 22. Due to this shape, the insulating base 2F has a base protrusion 24 that overlaps with the main body 41 in a planar perspective view. The main body 41 has an enlarged portion, and is joined to the base protrusion 24, thereby improving the bonding strength between the metal member 4F and the insulating base 2F. Furthermore, by providing the base protrusion 24, the possibility that the bonding material bonding the metal member 4F and the insulating base 2F will creep up and protrude onto the first surface 21 can be reduced.

[0071] Furthermore, since the metal member 4F has an enlarged portion and is shaped like a block with a large cross-sectional area on the second surface 22 side, the heat from the element 70 is diffused laterally as it travels toward the second surface 22, thereby improving heat dissipation.

[0072] Furthermore, compared to the metal member 4 of embodiment 1 (see FIGS. 2 and 6), the metal member 4F has an enlarged portion closer to the element 70 (or the mounting region R), so that heat is diffused at a position close to the element 70 and transferred through a large heat conduction path (main body portion 41), improving heat dissipation. Also, compared to the metal member 4E of embodiment 6, the volume of the metal member 4F can be reduced without significantly reducing the heat conduction path, resulting in a reduction in weight and improved strength around the through hole 23 of the insulating base 2F.

[0073] Eighth Embodiment FIG. 17 is a perspective view of a metal member 4G according to an eighth embodiment and a cross-sectional view of an electronic device 900G including the metal member 4G.

[0074] As shown in the example of FIG. 17 , the protrusion 42 of the metal member 4G may have a columnar portion with a substantially uniform cross-sectional area parallel to the first surface 21, and the main body 41 and the protrusion 42 may have an enlarged portion in which the cross-section parallel to the first surface 21 expands in the direction from the first surface 21 toward the second surface 22. Specifically, the metal member 4G may have an enlarged portion extending from the lower portion of the protrusion 42 to the upper portion of the main body 41. In this case, the insulating base 2G may have a base protrusion 24. The enlarged portion of the main body 41 is bonded to the base protrusion 24, thereby improving the bonding strength between the metal member 4G and the insulating base 2G. Furthermore, the base protrusion 24 reduces the possibility that the bonding material bonding the metal member 4G and the insulating base 2G will creep up and protrude onto the first surface 21.

[0075] Furthermore, since the metal member 4G has an enlarged portion and the second surface 22 side is in the shape of a block with a large cross-sectional area, the heat from the element 70 is diffused laterally as it travels in the direction of the second surface 22, thereby improving heat dissipation.

[0076] Like the metal member 4D of the fifth embodiment, the metal member 4G has an enlarged portion positioned closer to the element 70, and therefore has better heat dissipation properties. In addition, because the enlarged portion is positioned directly below the element mounting region R, it is possible to improve heat dissipation by being closer to the element 70 (or the submount 80), and to facilitate positioning of the element 70 (or the submount 80).

[0077] The expanded portion from the protrusion 42 to the main body 41 may be stepped or inclined, as shown in Fig. 17. The stepped expanded portion from the protrusion 42 to the main body 41 can more easily position the element 70 (or the submount 80). Furthermore, the stepped expanded portion of the main body 41 reduces the possibility of the bonding material creeping up and spilling onto the first surface 21, improves the positioning of the element 70, and improves the bonding between the metal member 4G and the insulating base 2G.

[0078] (Summary) (1) A substrate according to aspect 1 of the present disclosure comprises an insulating base having a first surface on which an element is arranged, a second surface opposite the first surface, and a through hole penetrating from the first surface to the second surface, a wiring conductor including a plurality of connection terminals located on the first surface and connected to the element, and a plurality of external terminals located on the outer surface of the insulating base and connected to a mounting substrate, and a metal member at least a portion of which is located within the through hole, the metal member having a main body portion located within the through hole and a protrusion portion protruding from the first surface, the protrusion portion having an element mounting region on which the element is mounted and a first side surface perpendicular to the first surface.

[0079] (2) A substrate according to aspect 2 of the present disclosure is the metal member of aspect 1, wherein the area of ​​the second surface side end of the main body is larger than the area of ​​a cross section of the protrusion parallel to the first surface.

[0080] (3) A substrate according to aspect 3 of the present disclosure is such that the metal member of aspect 1 or 2 above has a columnar portion in which the cross-sectional area parallel to the first surface is approximately uniform, and the main body and / or the protrusion has an enlarged portion in which the cross-sectional area parallel to the first surface expands in the direction from the first surface toward the second surface.

[0081] (4) A substrate according to a fourth aspect of the present disclosure is the substrate of the third aspect, wherein the insulating base has a base protrusion that protrudes toward the inside of the through hole.

[0082] (5) A substrate according to aspect 5 of the present disclosure is any one of aspects 1 to 4 above, wherein the insulating base has a bonding area on the first surface to which a lid capable of accommodating the element is bonded, and a frame portion surrounding the bonding area and positioned on the first surface.

[0083] (6) A substrate according to aspect 6 of the present disclosure is the substrate of aspect 5, wherein the frame portion has at least one notch on the bonding region side.

[0084] (7) A substrate according to aspect 7 of the present disclosure is any one of aspects 1 to 6 above, wherein the insulating base has a recess on the first surface that communicates with the through hole, and the recess is located on the first side around the through hole.

[0085] (8) A substrate according to aspect 8 of the present disclosure is any one of aspects 1 to 7 above, wherein the external terminal is located on the second surface and extends from the second surface to a side surface connecting the first surface and the second surface.

[0086] (9) A substrate according to aspect 9 of the present disclosure is the substrate of any one of aspects 1 to 7 above, wherein the external terminal is located on one of the side surfaces connecting the first surface and the second surface.

[0087] (10) A substrate according to aspect 10 of the present disclosure is the substrate of aspect 9 above, wherein the external terminal extends from the side surface to the first surface, or extends to both the first surface and the second surface.

[0088] (11) A substrate according to aspect 11 of the present disclosure is any of aspects 1 to 10 above, wherein the metal member has a bilaterally symmetrical shape in a cross section perpendicular to the first surface and the first side surface, and the distance from the first side surface to the outer edge of the insulating base in a direction perpendicular to the first side surface is greater than the distance from a second side surface of the metal member located opposite the first side surface to the outer edge.

[0089] (12) A substrate according to aspect 12 of the present disclosure is the same as in aspect 11 above, except that the external terminals are located on the second surface, and in plan view, the total area of ​​the external terminals located outside the line extending from the virtual line corresponding to the first side surface is greater than the total area of ​​the external terminals located outside the line extending from the virtual line corresponding to the second side surface.

[0090] (13) A package for storing an element according to aspect 13 of the present disclosure includes the substrate according to any one of aspects 1 to 12 above and a lid with a window.

[0091] (14) An electronic device according to a fourteenth aspect of the present disclosure includes the element housing package according to the thirteenth aspect and an element.

[0092] [Additional Notes] The invention according to the present disclosure has been described above based on the drawings and examples. However, the invention according to the present disclosure is not limited to the above-described embodiments. In other words, the invention according to the present disclosure can be modified in various ways within the scope of the present disclosure, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the invention according to the present disclosure. In other words, it should be noted that a person skilled in the art could easily make various modifications or corrections based on the present disclosure. It should also be noted that these modifications or corrections are included in the scope of the present disclosure.

[0093] 10, 10A, 10B, 10C, 10D, 10E, 10F, 10G... Substrate 2, 2A, 2B, 2C, 2D, 2E, 2F, 2G... Insulating base 20... Base 21... First surface 212... Bonding region 22... Second surface 23, 23A... Through hole 24... Base protrusion 25... Recessed part 29... Frame portion 3, 3A... Wiring conductor 31, 31A... Connection terminal 32, 32A... External terminal 4, 4A, 4B, 4C, 4D, 4E, 4F, 4G... Metal member 41... Main body portion 412... First portion 413... Second portion 42... Protruding portion 421... First side surface 422... Second side surface 60... Lid body 70... Element 80...Submount 100, 100A...Package 900, 900A...Electronic device

Claims

1. A substrate comprising: an insulating base having a first surface on which an element is arranged, a second surface opposite the first surface, and a through hole penetrating from the first surface to the second surface; wiring conductors including a plurality of connection terminals located on the first surface and connected to the element, and a plurality of external terminals located on the outer surface of the insulating base and connected to a mounting substrate; and a metal member at least a portion of which is located within the through hole, wherein the metal member has a main body located within the through hole and a protruding portion protruding from the first surface, and the protruding portion has an element mounting region on which the element is mounted and has a first side surface perpendicular to the first surface.

2. The substrate according to claim 1, wherein in said metal member, the area of ​​the end of said main body portion on said second surface side is larger than the area of ​​a cross section of said protrusion portion parallel to said first surface.

3. A substrate according to claim 1 or 2, wherein the metal member has a protruding portion having a columnar portion with a substantially uniform cross-sectional area parallel to the first surface, and the main body and / or the protruding portion has an enlarged portion whose cross-section parallel to the first surface expands in the direction from the first surface toward the second surface.

4. The substrate according to claim 3, wherein the insulating base has a base protrusion that protrudes toward the inside of the through hole.

5. A substrate according to any one of claims 1 to 4, wherein the insulating base has a bonding area on the first surface to which a lid capable of accommodating the element is bonded, and a frame portion surrounding the bonding area and positioned on the first surface.

6. The substrate according to claim 5, wherein the frame portion has at least one notch on the bonding region side.

7. A substrate according to any one of claims 1 to 6, wherein the insulating base has a recess in the first surface that communicates with the through hole, and the recess is located on the first side surface side around the through hole.

8. A substrate according to any one of claims 1 to 7, wherein the external terminals are located on the second surface and extend from the second surface to a side surface connecting the first surface and the second surface.

9. A substrate according to any one of claims 1 to 7, wherein the external terminal is located on one of the side surfaces connecting the first surface and the second surface.

10. The substrate according to claim 9, wherein the external terminals extend from the side surfaces to the first surface or to both the first surface and the second surface.

11. A substrate according to any one of claims 1 to 10, wherein the metal member has a bilaterally symmetrical shape in a cross section perpendicular to the first surface and first side surface, and the distance from the first side surface to the outer edge of the insulating base in a direction perpendicular to the first side surface is greater than the distance from a second side surface of the metal member located opposite the first side surface to the outer edge.

12. The substrate according to claim 11, wherein the external terminals are located on the second surface, and in plan view, the total area of ​​the external terminals located outside a line extending from a virtual line corresponding to the first side surface is greater than the total area of ​​the external terminals located outside a line extending from a virtual line corresponding to the second side surface.

13. A package for housing an element, comprising the substrate according to any one of claims 1 to 12 and a lid with a window.

14. An electronic device comprising the package for storing an element according to claim 13 and an element.

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