Wiring board, package, and optical module

Abstract

To provide a wiring board, a package, and an optical module which can be miniaturized and have high strength.SOLUTION: The wiring substrate includes a first layer having a first upper surface and a second insulating layer located on the first upper surface. The first upper surface has an element mounting region. The second insulating layer has a first wall surface, a second wall surface, and a second upper surface. The first wall surface faces the element mounting region in plan view. The second wall surface intersects and connects to the first wall surface and faces the element mounting region in a plan view. The second upper surface is connected to the first wall surface and the second wall surface. The first wall surface has a notched surface notched from the second upper surface to the first upper surface at a position connected to the second wall surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a wiring board, a package, and an optical module. [Background technology]

[0002] BACKGROUND ART A package for housing an element in which the inner corners of the frame are cut out is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-094701 Summary of the Invention [Problem to be solved by the invention]

[0004] While the number and size of elements mounted on wiring boards are increasing, there is a demand for miniaturization of the wiring boards themselves. Furthermore, wiring boards, and in particular the wall surfaces of the wiring boards, are also required to protect the elements mounted thereon, so they are also required to be strong.

[0005] Therefore, the present disclosure provides a wiring board, a package, and an optical module that can be miniaturized yet have high strength. [Means for solving the problem]

[0006] (1) One embodiment of a wiring board according to the present disclosure includes: a first layer having a first top surface; a second insulating layer located on the first top surface; the first upper surface has an element mounting area; the second insulating layer has a first wall surface facing the element mounting area in a plan view, a second wall surface that intersects and connects with the first wall surface and faces the element mounting area in a plan view, and a second top surface that connects with the first wall surface and the second wall surface, The first wall surface has a notched surface cut out from the second upper surface to the first upper surface at a position where the first wall surface is connected to the second wall surface.

[0007] (2) One embodiment of a wiring board according to the present disclosure is The wiring board according to (1), a metal layer covering the element mounting area; The area of ​​the first upper surface that is exposed by cutting out the first wall surface has a plated area that is covered by the metal layer extending from the element mounting area, and a non-plated area that is not covered by the metal layer.

[0008] (3) One embodiment of a wiring board according to the present disclosure is The wiring board according to (1) or (2), The cutout surface has an arc shape in a plan view.

[0009] (4) One embodiment of a wiring board according to the present disclosure is The wiring board according to (3), The cutout surface has a semicircular arc shape in a plan view.

[0010] (5) One embodiment of a wiring board according to the present disclosure is The wiring board according to (3), The cutout surface has a semi-elliptical arc shape with its major axis extending along the first wall surface in a plan view.

[0011] (6) One embodiment of a wiring board according to the present disclosure is A wiring board according to any one of (1) to (5) above, a third insulating layer located on the second top surface; the third insulating layer has a third wall surface facing the element mounting area in a plan view, and a fourth wall surface that intersects and connects to the third wall surface and faces the element mounting area in a plan view, the third wall surface has the same normal direction as the first wall surface and is located above the second upper surface with a gap between it and the first wall surface in a plan view; the fourth wall surface has the same normal direction as the second wall surface, the third wall surface has a corner surface at a position where the third wall surface is connected to the fourth wall surface, the corner surface approaching the element mounting area in a plan view as it approaches the fourth wall surface, At least a portion of the corner surface overlaps with the notch surface in the normal direction of the second wall surface.

[0012] (7) One embodiment of a wiring board according to the present disclosure is The wiring board according to (6), The corner surface is curved and has an arc shape with a central angle of 90° in a plan view.

[0013] (8) One embodiment of a wiring board according to the present disclosure is The wiring board according to (6) or (7), The dimension of the notch surface in the normal direction of the second wall surface is equal to or smaller than the dimension of the corner surface in the normal direction of the second wall surface.

[0014] (9) One embodiment of a wiring board according to the present disclosure is The wiring board according to any one of (6) to (8), The dimension of the notch surface in the normal direction of the second wall surface is equal to the dimension of the corner surface in the normal direction of the second wall surface.

[0015] (10) One embodiment of a wiring board according to the present disclosure is A wiring board according to any one of (1) to (9), The normal direction of the notched surface at the position where it connects to the second wall surface coincides with the normal direction of the second wall surface.

[0016] (11) One embodiment of a wiring board according to the present disclosure is The wiring board according to any one of (6) to (10), The normal direction of the corner face at the position where it connects to the fourth wall face coincides with the normal direction of the fourth wall face.

[0017] (12) One embodiment of a wiring board according to the present disclosure is The wiring board according to any one of (6) to (9) and (11), a normal direction of the notched surface at a position where the notched surface is connected to the second wall surface coincides with a normal direction of the second wall surface, The second wall surface and the fourth wall surface are flush with each other.

[0018] (13) One embodiment of a wiring board according to the present disclosure is The wiring board according to any one of (6) to (9), (11) and (12), In a plan view, all of the corner surfaces overlap with the second insulating layer.

[0019] (14) One embodiment of the package according to the present disclosure comprises: Any one of the wiring substrates (1) to (13) above; and a wall body that is connected and / or bonded to the wiring board.

[0020] (15) One embodiment of the optical module according to the present disclosure includes: The package (14) above, an optical element mounted on the element mounting area; and a lid joined to the package. [Effects of the Invention]

[0021] According to the present disclosure, it is possible to obtain a wiring board, a package, and an optical module that can be miniaturized yet has high strength. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a perspective view of a wiring substrate according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is an enlarged perspective view of a main part A shown in FIG. [Figure 3] FIG. 2 is an enlarged plan view of the vicinity of a main part A shown in FIG. [Figure 4] 1. FIG. 4 is an enlarged plan view showing a modified example of the vicinity of the main part A shown in FIG. [Figure 5]FIG. 2 is a rear perspective view of the wiring board according to the embodiment of the present disclosure. [Figure 6] FIG. 1 is a perspective view of a package and an optical module according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, for the sake of convenience, the figures referred to below are simplified views of the main components necessary for explaining the embodiments. Therefore, embodiments of the present disclosure may include any components not shown in the figures referred to. Furthermore, the dimensions of the components in the figures do not faithfully represent the actual dimensions, dimensional ratios, etc. of the components. For convenience, directions are defined using the Cartesian coordinate system XYZ. The positive side of the X direction is the right side, the positive side of the Y direction is the front side, and the positive side of the Z direction is the top side. In this disclosure, "planar view" refers to a view from the top side of the first upper surface (the positive side of the Z direction) and includes planar perspective view.

[0024] In the following description, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used. These expressions do not necessarily mean "constant," "orthogonal," "perpendicular," or "parallel" in their strict sense. In other words, these expressions allow for deviations due to, for example, manufacturing precision, installation precision, etc. Numerical ranges expressed using "to" include the numerical values ​​before and after it as the lower and upper limits, respectively.

[0025] [Wiring board] As shown in FIG. 1 and other figures, the wiring substrate 10 includes a first layer 11 having a first upper surface 111 and a second insulating layer 12 located on the first upper surface 111. The first upper surface 111 includes a device mounting area 112. The device mounting area 112 is an area for mounting an element such as an optical element 31 (described later). The device mounting area 112 does not necessarily have to be an area for directly mounting an element. The device mounting area 112 may be an area for mounting an element via a support or the like, or may be an area for mounting a substrate on which an element is mounted or electronic components. The second insulating layer 12 includes a first wall surface 121 facing the device mounting area 112 in a plan view, a second wall surface 122 intersecting and connecting with the first wall surface 121 and facing the device mounting area 112 in a plan view, and a second upper surface 123 connecting with the first wall surface 121 and the second wall surface 122. When a third insulating layer 13 described below overlaps the second upper surface 123, the area where the third insulating layer 13 overlaps is also referred to as the second upper surface 123. The second insulating layer 12 may be in the shape of a frame surrounding the element mounting area 112 in a plan view. The second insulating layer 12 may be formed such that a portion including the first wall surface 121 and a portion including the second wall surface 122 are integrally formed, or may be formed such that a portion including the first wall surface 121 and a portion including the second wall surface 122 are joined together and formed separately.

[0026] The first wall surface 121 has a notched surface 121a cut out from the second upper surface 123 to the first upper surface 111 at a position where it connects to the second wall surface 122. One end of the notched surface 121a is located at the intersection of the first wall surface 121 and the second wall surface 122, and is connected to one end of the second wall surface 122. The notched surface 121a is a surface formed by cutting out the first wall surface 121, that is, the notched surface 121a is not located outside the second wall surface 122 (on the opposite side of the second wall surface 122 from the element mounting area 112, on the negative side in the Y direction).

[0027] By providing cutout surface 121a at the position where first wall surface 121 intersects and connects with second wall surface 122, it becomes possible to arrange elements closer to first wall surface 121 and second wall surface 122 while alleviating stress on the connection portion between first wall surface 121 and second wall surface 122. This makes it possible to reduce the size of wiring board 10. Furthermore, by not positioning cutout surface 121a outside second wall surface 122, for example, when third insulating layer 13 is positioned on second upper surface 123 and second wall surface 122 of second insulating layer 12 and fourth wall surface 132 of third insulating layer 13 are flush with each other, there will be no portion of third insulating layer 13 that is not supported by second insulating layer 12. As a result, even if cutout surface 121a is provided, there will be no portion of third insulating layer 13 that is not supported by second insulating layer 12, and since third insulating layer 13 is supported by second insulating layer 12, the possibility of the shape of wiring board 10 being distorted and the strength of wiring board 10 being weakened as a result is reduced.

[0028] The wiring board 10 may have a metal layer 14 covering the device mounting area 112. The metal layer 14 may be a metallized layer formed by plating, for example. Covering the device mounting area 112 with the metal layer 14 makes it easier for the device to be mounted to be fixed to the wiring board 10 with a metal brazing material. The metal layer 14 may cover the entire device mounting area 112, or may cover only a portion of it.

[0029] The region of the first upper surface 111 exposed by cutting out the first wall surface 121 may have a plated region 113 covered by the metal layer 14 extending from the device mounting region 112, and a non-plated region 114 not covered by the metal layer 14. For example, if the second insulating layer 12 overlaps a portion of the metal layer 14, a portion of the region of the first upper surface 111 exposed by cutting out the first wall surface 121 becomes the plated region 113. If the second insulating layer 12 overlaps a portion of the metal layer 14, the possibility of an area not covered by the metal layer 14 occurring in the device mounting region 112 due to manufacturing errors is reduced. This reduces the possibility of device mounting defects. On the other hand, the metal brazing material is less likely to flow in the non-plated region 114. Therefore, the presence of the non-plated region 114 in the region exposed by cutting out the first wall surface 121 makes it more likely that the metal brazing material will flow in that region, making it easier to form a fillet from the metal layer 14 to the device. This makes it easier to improve the bonding strength between the wiring board 10 and the element.

[0030] The shape of cutout surface 121a is not particularly limited, but if it is arc-shaped in a plan view, stress acting on the connection portion between first wall surface 121 and second wall surface 122 is more likely to be alleviated. Specifically, cutout surface 121a may be semicircular in a plan view as shown in FIG. 3. A semicircular arc shape refers to an arc shape of a perfect circle with a central angle of 170 to 190 degrees. If cutout surface 121a is semicircular in a plan view, it is easier to both ensure an area on first upper surface 111 where wiring can be installed and alleviate stress.

[0031] Furthermore, as shown in FIG. 4, the cutout surface 121a may have a semi-elliptical arc shape with its major axis extending along the first wall surface 121 in a plan view. A semi-elliptical arc shape refers to an elliptical arc shape with a central angle of 170 to 190°. When the cutout surface 121a has a semi-elliptical arc shape with its major axis extending along the first wall surface 121 in a plan view, the plating region 113 is elongated in a direction along the first wall surface 121 in a plan view. This lengthens the fillet formed from the metal layer 14 to the element when the element is mounted near the first wall surface 121. This facilitates improving the bonding strength between the wiring substrate 10 and the element. The shape of the cutout surface 121a may also be other shapes, such as a rectangle with rounded corners in a plan view.

[0032] As shown in FIG. 1 and other figures, the wiring board 10 may further include a third insulating layer 13 located on the second upper surface 123. The third insulating layer 13 may have a third wall surface 131 facing the device mounting area 112 in a planar view, a fourth wall surface 132 that intersects and connects with the third wall surface 131 and faces the device mounting area 112 in a planar view, and a third upper surface 133 that connects with the third wall surface 131 and the fourth wall surface 132. The phrase "facing the device mounting area 112 in a planar view" includes the case where the third upper surface 133 is separated from the device mounting area 112 in a planar view. When a wall body 21 (described later) overlaps the third upper surface 133, the area where the wall body 21 overlaps is also referred to as the third upper surface 133. The third insulating layer 13 may be frame-shaped and surround the device mounting area 112 in a planar view. The third insulating layer 13 may be formed such that a portion including the third wall surface 131 and a portion including the fourth wall surface 132 are integrally formed, or may be formed such that a portion including the third wall surface 131 and a portion including the fourth wall surface 132 are joined together and formed separately.

[0033] The third wall surface 131 may have the same normal direction as the first wall surface 121 and may be located above the second upper surface 123 with a gap between it and the first wall surface 121 in a plan view. The fourth wall surface 132 may have the same normal direction as the second wall surface 122. In the drawing, the normal direction of the first wall surface 121 and the normal direction of the third wall surface 131 are the X direction. The normal direction of the second wall surface 122 and the normal direction of the fourth wall surface 132 are the Y direction.

[0034] The third wall surface 131 may have a corner surface 131a at a position where it connects with the fourth wall surface 132, the corner surface 131a approaching the element mounting region 112 in a plan view as it approaches the fourth wall surface 132. For example, the corner surface 131a may have a tapered shape. One end of the corner surface 131a may be located at the intersection of the third wall surface 131 and the fourth wall surface 132 and connected to one end of the fourth wall surface 132. At least a portion of the corner surface 131a may overlap the notched surface 121a in the normal direction (Y direction) of the second wall surface 122. By having the corner surface 131a at a position where the third wall surface 131 intersects and connects with the fourth wall surface 132, stress applied to the connection portion between the third wall surface 131 and the fourth wall surface 132 can be alleviated.

[0035] Corner surface 131a may be curved or not. If corner surface 131a is curved, it may be an arc shape with a central angle of 90° in plan view. If corner surface 131a is an arc shape with a central angle of 90° in plan view, it becomes easier to alleviate stress on third wall surface 131 and fourth wall surface 132 in an appropriate and balanced manner. Note that the "arc shape with a central angle of 90°" allows for manufacturing errors.

[0036] A dimension L1 of the cutout surface 121a in the normal direction (Y direction) of the second wall surface 122 may be equal to or smaller than a dimension L2 of the corner surface 131a in the normal direction (Y direction) of the second wall surface 122. Since the dimension L1 of the cutout surface 121a is relatively small, the area in which wiring can be installed can be made larger on the second upper surface 123, which is closer to the element mounting area 112, than on the third upper surface 133.

[0037] As shown in FIG. 3 , the dimension L1 of the cutout surface 121a in the normal direction (Y direction) of the second wall surface 122 may be equal to the dimension L2 of the corner surface 131a in the normal direction (Y direction) of the second wall surface 122. This can efficiently relieve both the stress applied to the second insulating layer 12 and the stress applied to the third insulating layer 13. Furthermore, when the wiring conductors 15 electrically connected to the elements are provided on the second upper surface 123 and the third upper surface 133 with a gap between the corner surface 131a and the cutout surface 121a, the areas on the second upper surface 123 and the third upper surface 133 where the wiring conductors 15 can be installed become closer in the Y direction. This allows the elements mounted on the element mounting area 112 to be efficiently connected to the wiring conductors 15. This is advantageous for miniaturizing the wiring board 10. The elements and the wiring conductors 15 may be connected via, for example, wire bonding, a flexible printed circuit (FPC), or the like.

[0038] In addition, for example, as shown in Figure 4, in a case where the cutout surface 121a is a semi-elliptical arc shape with its major axis direction along the first wall surface 121 in a planar view, the dimension L1 of the cutout surface 121a in the normal direction (Y direction) of the second wall surface 122 may be larger than the dimension L2 of the corner surface 131a in the normal direction (Y direction) of the second wall surface 122.

[0039] 3 and other figures, the normal direction of cutout surface 121a at the position where it connects to second wall surface 122 may coincide with the normal direction (Y direction) of second wall surface 122. In other words, cutout surface 121a may be smoothly connected to second wall surface 122. This further reduces the stress applied to the connecting portion between first wall surface 121 and second wall surface 122.

[0040] 3 and other figures, the normal direction of the corner surface 131a at the position where it connects to the fourth wall surface 132 may coincide with the normal direction (Y direction) of the fourth wall surface 132. In other words, the corner surface 131a may be smoothly connected to the fourth wall surface 132. This further reduces the stress applied to the connecting portion between the third wall surface 131 and the fourth wall surface 132.

[0041] 2 and other figures, second wall surface 122 and fourth wall surface 132 may be flush. Because notched surface 121a is not located outside second wall surface 122, if second wall surface 122 and fourth wall surface 132 are flush, a configuration can be achieved in which there is no portion of third insulating layer 13 that is not supported by second insulating layer 12. As a result, even if notched surface 121a is provided, there is no portion of third insulating layer 13 that is not supported by second insulating layer 12, and third insulating layer 13 is supported by second insulating layer 12, thereby reducing the possibility of the shape of wiring board 10 being distorted and the strength of wiring board 10 being weakened as a result.

[0042] 3 and other figures, in a plan view, all of corner surface 131a may overlap second insulating layer 12. This eliminates any portion of corner surface 131a that is not supported by second insulating layer 12, and corner surface 131a is supported by second insulating layer 12, reducing the possibility that the shape of wiring board 10 will be distorted and the strength of wiring board 10 will be weakened as a result.

[0043] As shown in FIG. 3 and other figures, when both the cutout surface 121a and the corner surface 131a are curved, the curvature of the cutout surface 121a may be smaller than the curvature of the corner surface 131a.

[0044] The material of the first layer 11 may be an insulator such as ceramic or resin, or may be a metal such as FeNiCO, CuW, or Cu. The material of the insulating layers such as the second insulating layer 12 and the third insulating layer 13 may be, for example, ceramic or resin. The first layer 11, the second insulating layer 12, and the third insulating layer 13 may be primarily composed of ceramic or resin. The first layer 11 may be primarily composed of metal. The term "primary component" refers to a component that accounts for 60% by mass or more. Examples of ceramics include aluminum oxide sintered compacts (alumina ceramics), aluminum nitride sintered compacts, silicon carbide sintered compacts, mullite sintered compacts, and glass ceramics. Examples of resins include epoxy resins, polyimides, and liquid crystal polymers. When the first layer 11, the second insulating layer 12, and the third insulating layer 13 are primarily composed of ceramic, the heat dissipation and rigidity of the wiring board 10 are improved. The materials of the first layer 11, the second insulating layer 12, and the third insulating layer 13 may be the same or different.

[0045] As shown in FIG. 1 and other figures, the wiring board 10 may have one or more wiring conductors 15. The wiring conductors 15 are located on, for example, the second upper surface 123, the third upper surface 133, etc. The wiring conductors 15 may be signal conductors, ground conductors, or power conductors. The multiple wiring conductors 15 may have different uses. The multiple wiring conductors 15 may form a GSSG structure or a GSGSG structure. The GSSG structure is a differential line structure formed by multiple wiring conductors 15 arranged in the following order: ground conductor-signal conductor-signal conductor-ground conductor. The GSGSG structure is a differential line structure formed by multiple conductors arranged in the following order: ground conductor-signal conductor-ground conductor-signal conductor-ground conductor.

[0046] 1 and other figures, the wiring conductors 15 located on the second upper surface 123 may be spaced apart from the first wall surface 121. This reduces the possibility that plating formed on the wiring conductors 15 or conductive bonding materials connecting the wiring conductors 15 to electronic components or bonding wires will extend along the edges of the second upper surface 123 and the first wall surface 121, causing a short circuit between adjacent wiring conductors 15. The distance between the wiring conductors 15 located on the second upper surface 123 and the first wall surface 121 is, for example, 10 to 100 μm.

[0047] 1 and other figures, the wiring conductors 15 located on the third upper surface 133 may be spaced apart from the third wall surface 131. This reduces the possibility that plating formed on the wiring conductors 15 or a conductive bonding material between the wiring conductors 15 and an electronic component or a bonding wire will extend along the edge between the third upper surface 133 and the third wall surface 131, causing a short circuit between adjacent wiring conductors 15. The distance between the wiring conductors 15 located on the third upper surface 133 and the third wall surface 131 is, for example, 10 to 100 μm.

[0048] As shown in FIG. 1 and other figures, the wiring substrate 10 may have a first coating portion 16 located on the second upper surface 123 and in contact with the third wall surface 131. A portion of the first coating portion 16 may be located on the wiring conductor 15. This reduces the possibility that plating formed on the wiring conductor 15 will extend along the third wall surface 131 and cause a short circuit between adjacent wiring conductors 15. Furthermore, since a portion of the first coating portion 16 is located on the wiring conductor 15, the possibility that the wiring conductor 15 will peel off from the second upper surface 123 is reduced. A portion of the first coating portion 16 may be located between the second insulating layer 12 and the third insulating layer 13. In other words, a portion of the first coating portion 16 may overlap the third insulating layer 13 in a plan view. The material of the first coating portion 16 is, for example, ceramic.

[0049] As shown in FIG. 1 and other figures, the wiring board 10 may have a second coating portion 17 located on the third upper surface 133 and in contact with a wall body 21 (described later). A portion of the second coating portion 17 may be located on the wiring conductor 15. This reduces the possibility that plating formed on the wiring conductor 15 will extend along the wall body 21 and cause a short circuit between adjacent wiring conductors 15. Furthermore, since a portion of the second coating portion 17 is located on the wiring conductor 15, the possibility that the wiring conductor 15 will peel off from the third upper surface 133 is reduced. A portion of the second coating portion 17 may be located between the third insulating layer 13 and the wall body 21. In other words, a portion of the second coating portion 17 may overlap the wall body 21 in a plan view. The material of the second coating portion 17 is, for example, ceramic.

[0050] 5, the wiring board 10 may have one or more lead terminals 18 on a first lower surface 115 located on the opposite side of the first upper surface 111 of the first layer 11. The wiring board 10 may have a PGA (pin grid allay) formed by a plurality of lead pins on the first lower surface 115. An external board such as a PCB (printed circuit board) may be connected to the first lower surface 115. The PCB may be an FPC (flexible printed circuit board).

[0051] Examples of materials for the conductive members such as the metal layer 14, the wiring conductor 15, and the lead terminal 18 include tungsten, molybdenum, manganese, copper, silver, palladium, gold, platinum, nickel, cobalt, and alloys thereof. The metals contained in the respective conductive members may be the same or different from each other.

[0052] [package] As shown in FIG. 1 and other figures, the package 20 may include a wiring board 10 and a wall 21 connected and / or bonded to the wiring board 10. Here, "connected" refers to a state in which at least one layer of the wiring board 10 and the wall 21 are integrally formed from the same material. "Bonded" refers to a state in which the wall 21, which is separate from the wiring board 10, is combined with the wiring board 10 via a bonding material or the like. The wiring board 10 and the wall 21 may have both connected and bonded portions. The material of the wall 21 is, for example, ceramic, metal, resin, or the like.

[0053] 1 and other figures, the package 20 may have a through hole 22. The through hole 22 may be provided from the wiring substrate 10 to the wall body 21. The through hole 22 can be used, for example, to exchange light between the device accommodated in the device mounting region 112 and the outside of the package 20.

[0054] 1 and other figures, the package 20 may have a frame 23 on the wall 21. The frame 23 may be, for example, a seal ring. The frame 23 may be, for example, a member in which a frame-shaped metal plate containing an Fe-Ni alloy, an Fe-Ni-Co alloy, or the like is joined to a frame formed of a conductive paste containing a high-melting-point metal such as tungsten or molybdenum with a brazing material or the like.

[0055] [Optical module] 6, the optical module 30 may include a package 20, an optical element 31 mounted in an element mounting area 112, and a lid 32 joined to the package 20. Note that Fig. 6 is an exploded perspective view in which the package 20 and the lid 32 are disassembled.

[0056] The optical element 31 is, for example, a light-receiving element that can convert light into an electrical signal, or a light-emitting element that can convert an electrical signal into light. The optical element 31 is, for example, an optical semiconductor element. The light-receiving element can also be called an optical sensor, a photodetector, or the like. Examples of the light-receiving element include a PD (photodiode) and a CMOS (complementary metal-oxide-semiconductor). Examples of the light-emitting element include an LED (light-emitting diode), an LD (laser diode), and a surface-emitting element. The optical module 30 may have a plurality of optical elements 31, or may have different types of optical elements 31, such as a light-emitting element and a light-receiving element.

[0057] The optical element 31 does not necessarily have to be directly mounted on the element mounting area 112, but may be mounted via a support or the like, or may be mounted on a substrate or electronic component mounted on the element mounting area 112. The optical element 31 may be electrically connected to the wiring conductor 15 provided on the wiring board 10 via a wire or the like.

[0058] The optical element 31 may be spaced apart from the first wall surface 121 and the second wall surface 122. This reduces the possibility that the first wall surface 121 and the second wall surface 122 will be chipped due to a collision with the optical element 31.

[0059] The lid 32 may be a metal plate, or may be a wiring board 10 that requires electrical connection, such as a PCB (printed circuit board). The lid 32 is joined onto the frame 23, for example.

[0060] The optical module 30 can be used for, for example, optical communication or LiDAR (light detection and ranging). Specifically, the optical module 30 can be used in a LiDAR for an in-vehicle component.

[0061] In addition, the details shown in the above embodiments can be modified as appropriate without departing from the spirit of the present disclosure. The scope of the present invention includes the scope of the invention described in the claims and its equivalents. Various combinations of the embodiments are not limited to the examples of the above embodiments. Furthermore, combinations of the embodiments with each other are also possible. [Explanation of symbols]

[0062] 10. Wiring board 11 1st layer 111 1st top surface 112 Element mounting area 113 Plating Area 114 Non-plated area 115 1st bottom surface 12 Second insulating layer 121 First Wall 121a Notch surface 122 Second wall 123 2nd top surface 13 Third insulating layer 131 Third wall 131a Corner 132 Fourth Wall 133 Third top surface 14 Metal layer 15 Wiring conductor 16 First Court Section 17 Second Court Section 18 Lead terminal L1: Dimension of the notch surface in the normal direction of the second wall L2: Dimension of the corner in the normal direction of the second wall 20 packages 21 Wall 22 Through hole 23 Frame 30 Optical Modules 31 Optical elements 32 Lid

Claims

1. a first layer having a first top surface; a second insulating layer overlying the first top surface; the first upper surface has an element mounting area; the second insulating layer has a first wall surface facing the element mounting area in a plan view, a second wall surface that intersects and connects with the first wall surface and faces the element mounting area in a plan view, and a second top surface that connects with the first wall surface and the second wall surface, The first wall surface has a notched surface cut out from the second upper surface to the first upper surface at a position where the first wall surface is connected to the second wall surface. Wiring board.

2. a metal layer covering the element mounting area; a region of the first upper surface exposed by cutting out the first wall surface includes a plated region covered by the metal layer extending from the element mounting region, and a non-plated region not covered by the metal layer; The wiring board according to claim 1 .

3. The cutout surface is arcuate in plan view. The wiring board according to claim 1 .

4. The cutout surface has a semicircular arc shape in a plan view. The wiring board according to claim 3 .

5. The cutout surface has a semi-elliptical arc shape with a major axis extending along the first wall surface in a plan view. The wiring board according to claim 3 .

6. a third insulating layer located on the second top surface; the third insulating layer has a third wall surface facing the element mounting area in a plan view, and a fourth wall surface that intersects and connects with the third wall surface and faces the element mounting area in a plan view, the third wall surface has the same normal direction as the first wall surface and is located above the second upper surface with a gap between it and the first wall surface in a plan view; the fourth wall surface has the same normal direction as the second wall surface, the third wall surface has a corner surface at a position where the third wall surface is connected to the fourth wall surface, the corner surface approaching the element mounting area in a plan view as it approaches the fourth wall surface, At least a portion of the corner surface overlaps with the cutout surface in a normal direction of the second wall surface. The wiring board according to claim 1 .

7. The corner surface is curved and has an arc shape with a central angle of 90° in a plan view. The wiring board according to claim 6 .

8. a dimension of the cutout surface in the normal direction of the second wall surface is equal to or smaller than a dimension of the corner surface in the normal direction of the second wall surface; The wiring board according to claim 6 .

9. a dimension of the cutout surface in a normal direction of the second wall surface is equal to a dimension of the corner surface in the normal direction of the second wall surface; The wiring board according to claim 6 .

10. a normal direction of the cutout surface at a position where the cutout surface is connected to the second wall surface coincides with a normal direction of the second wall surface; The wiring board according to claim 1 .

11. a normal direction of the corner surface at a position where the corner surface is connected to the fourth wall surface coincides with a normal direction of the fourth wall surface; The wiring board according to claim 6 .

12. a normal direction of the notched surface at a position where the notched surface is connected to the second wall surface coincides with a normal direction of the second wall surface, The second wall surface and the fourth wall surface are flush with each other. The wiring board according to claim 11 .

13. In a plan view, all of the corner surfaces are overlapped with the second insulating layer. The wiring board according to claim 6 .

14. The wiring board according to claim 1; a wall body connected and / or joined to the wiring board; package.

15. A package according to claim 14; an optical element mounted on the element mounting area; a lid joined to the package, Optical module.

Images