Wiring board and semiconductor device

Abstract

A wiring board comprising: a first base material containing ceramic as a material; a second base material containing an organic material as a material and joined to the first base material; a recessed part positioned astride the second base material and the first base material and penetrating at least the second base material; and wiring positioned inside the second base material, wherein the second base material has a covering part positioned further toward the inside of the recessed part than a side surface of the first base material constituting the inner surface of the recessed part and covering a part of the side surface.

Description

Wiring board and semiconductor device

[0001] The present disclosure relates to a wiring substrate and a semiconductor device.

[0002] 2. Description of the Related Art Conventionally, a wiring board made of ceramic and having an opening in the center has been known (see, for example, Japanese Patent Application Laid-Open No. 2003-144998).

[0003] Special Publication No. 2012-522638

[0004] The wiring board of the present disclosure comprises a first substrate containing ceramic as a material, a second substrate containing an organic material as a material and bonded to the first substrate, a recess positioned across the second substrate and the first substrate and penetrating at least the second substrate, and wiring positioned inside the second substrate, wherein the second substrate is positioned inward of the recess relative to the side surface of the first substrate that constitutes the inner surface of the recess and has a covering portion that covers a portion of the side surface.

[0005] FIG. 1 is a perspective view showing an example of the configuration of a wiring board according to an embodiment. FIG. 2 is a cross-sectional view of one end as viewed from the arrow A-A shown in FIG. 1. FIG. 3 is a cross-sectional view of the other end as viewed from the arrow A-A shown in FIG. 1. FIG. 4 is an explanatory diagram (part 1) of a covering portion of a wiring board according to an embodiment. FIG. 5 is an explanatory diagram (part 2) of a covering portion of a wiring board according to an embodiment. FIG. 6 is a partial cross-sectional view showing an example of an inter-substrate wiring layer. FIG. 7 is a perspective view showing an example of the configuration of a semiconductor device according to an embodiment.

[0006] Hereinafter, embodiments for carrying out a wiring board and a semiconductor device according to the present disclosure (hereinafter referred to as "embodiments") will be described in detail with reference to the drawings. Note that the present disclosure is not limited to these embodiments. Furthermore, the embodiments can be appropriately combined as long as the processing content is not contradictory. Furthermore, the same components in the following embodiments will be assigned the same reference numerals, and redundant explanations will be omitted.

[0007] In addition, in the drawings referred to below, to make the explanation easier to understand, an orthogonal coordinate system may be shown in which the X-axis direction, Y-axis direction, and Z-axis direction, which are perpendicular to each other, are defined, and the Z-axis direction is the thickness direction of the wiring board.

[0008] <Embodiment> FIG. 1 is a perspective view showing an example of the configuration of a wiring board according to an embodiment. As shown in FIG. 1, the wiring board 100 according to the embodiment includes a first substrate 10, a second substrate 20, a recess 110, a first wiring 30 (see FIG. 2), a second wiring 40 (see FIG. 2), and a connecting conductor 50 (see FIG. 2). The wiring board 100 is a laminate of the first substrate 10 and the second substrate 20. The first substrate 10 contains an inorganic material as a material. The inorganic material may be ceramic. The second substrate 20 contains an organic material as a material. The organic material may be an organic resin. The detailed configurations of the first substrate 10 and the second substrate 20 will be described later using FIGS. 2 to 5.

[0009] The wiring substrate 100 may have a rectangular shape in a plan view, for example, when viewed from the second base material 20 side in the thickness direction (Z-axis direction) of the wiring substrate 100. The wiring substrate 100 may also have a recess 110 in the center in a plan view. The recess 110 may have a rectangular shape in a plan view. The recess 110 may have a bottom (a bottomed recess), or may not have a bottom, i.e., may be a through-hole that penetrates through the wiring substrate 100 in the thickness direction. The wiring substrate 100 may also have a configuration without the recess 110.

[0010] Ceramics have higher rigidity than organic materials. Therefore, the wiring substrate 100 composed of the first substrate 10 containing ceramic as a material and the second substrate 20 containing organic material as a material can have improved rigidity compared to a wiring substrate composed only of organic materials. This makes it easy to ensure the rigidity of the wiring substrate 100, even if the wiring substrate 100 is made thin, without adding reinforcing members or the like.

[0011] Furthermore, the wiring substrate 100 can be made smaller (thinner) than when the recess 110 is provided only in the second base material 20, i.e., only in an organic material. Furthermore, the wiring substrate 100 can be made lighter because the volumes of the first base material 10 and the second base material 20 can be reduced by the amount of the recess 110.

[0012] Furthermore, in the wiring substrate 100, the inner surface 101 of the first base material 10 and the inner surface 201 of the second base material 20, which form the inner surface 111 of the recess 110, may both be aligned parallel to the thickness direction of the wiring substrate 100. This makes it easier to control the direction of reflection when light emitted from the semiconductor element 310 (see FIG. 7 ) is reflected by the inner surface 101 or the inner surface 201, for example, when the semiconductor element 310 (see FIG. 7 ) mounted on the wiring substrate 100 is a light-emitting element.

[0013] Furthermore, in the wiring substrate 100, the inner surface 101 of the first base material 10 and the inner surface 201 of the second base material 20 may be flush with each other. This allows the inner surface 101 and the inner surface 201 to form an integrated flat surface, so that, for example, when the semiconductor element 310 mounted on the wiring substrate 100 is a light-emitting element, it becomes easier to control the direction of reflection of light emitted from the semiconductor element 310.

[0014] FIG. 2 is a cross-sectional view of one end portion as viewed from the arrow A-A shown in FIG. 1. Note that FIG. 2 shows an end portion on the inner edge side of the wiring board according to the embodiment. FIG. 3 is a cross-sectional view of the other end portion as viewed from the arrow A-A shown in FIG. 1. Note that FIG. 3 shows an end portion on the outer edge side of the wiring board according to the embodiment. FIGS. 4 and 5 are explanatory diagrams of the covering portion of the wiring board according to the embodiment. Note that FIG. 4 shows a perspective view showing the covering portion. Also, FIG. 5 shows a plan view showing the covering portion. In FIG. 5, the covering portion is highlighted by adding dots.

[0015] <First Substrate> The first substrate 10 is made of ceramic. Examples of ceramic that can be used include ceramics made of at least one material selected from the group consisting of aluminum oxide, silicon oxide, zirconium oxide, silicon carbide, silicon nitride, and aluminum nitride, and ceramics made of composite oxides such as mullite, zircon, steatite, enstatite, glass ceramics, and glass. The first substrate 10 contains a glass component in addition to the ceramic.

[0016] As shown in Fig. 2 , the first substrate 10 has a first surface 11 and a second surface 12 located opposite the first surface 11. The first substrate 10 may be a plate-like body having the first surface 11 and the second surface 12 as main surfaces. Furthermore, as shown in Fig. 3 , the first substrate 10 has a first side surface 13 connecting the first surface 11 and the second surface 12. The first side surface 13 forms the outer surface of the first substrate 10.

[0017] The first substrate 10 may also have a plurality of ceramic layers 14. In this case, the plurality of ceramic layers 14 may be stacked along the thickness direction (Z-axis direction) of the first substrate 10. By configuring the first substrate 10 using a plurality of ceramic layers 14 in this manner, it is possible to obtain a first substrate 10 having a wiring layer 32 (described later) therein.

[0018] The wiring board 100 having such a first base material 10 has a high degree of freedom in design. Furthermore, by configuring the first base material 10 using a plurality of ceramic layers 14, it is possible to manufacture the first base material 10 while checking for each layer whether the first wiring 30, which will be described later, is properly formed. This allows the yield of the first base material 10 to be improved.

[0019] In the example shown in Fig. 2, the first substrate 10 has two ceramic layers 14, but the number of ceramic layers 14 is not limited to two. The number of ceramic layers 14 may be three or more. Furthermore, the first substrate 10 does not necessarily have to have a multi-layer structure. In other words, the first substrate 10 may be a single layer.

[0020] As shown in Fig. 3, in the first substrate 10, the second surface 12 has a central portion 15 and an inclined portion 16. The central portion 15 is a region excluding the outer edge side of the second surface 12 in a plan view. The central portion 15 is a flat surface. The inclined portion 16 is located closer to the outer edge than the central portion 15. The inclined portion 16 is an inclined surface that inclines toward the first surface 11 as it approaches the outer edge of the second surface 12.

[0021] By providing such an inclined portion 16, the first substrate 10 does not have any sharp edges on the second surface 12, thereby reducing the possibility of damage due to collision with other components.

[0022] When the first substrate 10 is rectangular, the inclined portions 16 may be located on each of the four sides 17 (see FIG. 5 ) of the first substrate 10 in a plan view. In this way, the inclined portions 16 of the second surface 12 extend around the entire periphery of the first substrate 10, further reducing the possibility of breakage due to collision with other components, etc.

[0023] Furthermore, a portion of the first side surface 13 of the first substrate 10 is exposed from the second substrate 20. This exposes the ceramic layer 14, which has high thermal conductivity, and is advantageous in terms of heat dissipation. Note that half or more of the area of ​​the first side surface 13 of the first substrate 10 may be exposed from the second substrate 20.

[0024] <Second Base Material> As described above, the second base material 20 includes an organic material. The organic material may be an organic resin. The organic resin may be, for example, an epoxy resin, an acrylic resin, a polycarbonate resin, a polyimide resin, an olefin resin, or a polyphenylene resin. The second base material 20 may also include multiple types of organic resins.

[0025] The organic resin may be, for example, polytetrafluoroethylene (PTFE) or other fluororesins or polyphenylene ether resins. The second substrate 20 may contain components other than the organic resin. Examples of components other than the organic resin contained in the second substrate 20 include inorganic materials such as silica and rubber materials. The content of the inorganic material such as silica in the second substrate 20, in terms of mass %, may be lower than the content of the organic resin in the second substrate 20. More specifically, the content of the inorganic material such as silica in the second substrate 20 may be 50 mass % or more of the second substrate 20, and the content of the organic resin in the second substrate 20 may be 50 mass % or less of the second substrate 20.

[0026] As shown in Fig. 2 , the second substrate 20 has a third surface 21 and a fourth surface 22 located opposite the third surface 21. The second substrate 20 may be a plate-like body having the third surface 21 and the fourth surface 22 as main surfaces. Furthermore, as shown in Fig. 3 , the second substrate 20 has a second side surface 23 connecting the third surface 21 and the fourth surface 22. The second side surface 23 forms the outer surface of the second substrate 20.

[0027] The second substrate 20 is overlaid on the first surface 11 of the first substrate 10. The third surface 21 of the second substrate 20 is bonded to the first surface 11 of the first substrate 10. In other words, the second substrate 20 is directly bonded to the first substrate 10 without an adhesive layer therebetween.

[0028] In this way, since there is no adhesive layer for joining the first base material 10 and the second base material 20, the thickness of the wiring board 100 is reduced, and miniaturization is possible.

[0029] The second base material 20 has a plurality of organic resin layers 24. The plurality of organic resin layers 24 are stacked along the thickness direction (Z-axis direction) of the second base material 20. By configuring the second base material 20 using the plurality of organic resin layers 24, it is possible to obtain a second base material 20 having a wiring layer 42 therein, which will be described later. A wiring board 100 having such a second base material 20 has a high degree of freedom in design.

[0030] 2, the second base material 20 has three organic resin layers 24, but the number of organic resin layers 24 is not limited to three. The number of organic resin layers 24 may be two, or may be four or more.

[0031] The second substrate 20 containing an organic material is easier to form a fine wiring pattern on than a substrate containing an inorganic material. On the other hand, the first substrate 10 containing a ceramic material has higher rigidity than the second substrate 20. Furthermore, the first substrate 10 containing a ceramic material has a lower density than the second substrate 20.

[0032] The wiring board 100 can increase rigidity while achieving finer wiring and narrower pitches by combining the first substrate 10 and the second substrate 20. Since warping of the board becomes more pronounced as the board becomes larger, the configuration of the wiring board 100 in which the first substrate 10 compensates for the low rigidity of the second substrate 20 is particularly useful for increasing the size of the board.

[0033] Specifically, the organic resin layer 24 of the second substrate 20 may contain an epoxy resin as a material. The ceramic layer 14 of the first substrate 10 may contain a ceramic containing hydroxyl groups as a material. In this case, the second substrate 20 may be chemically bonded to the first substrate 10 via the hydroxyl groups. This allows the first substrate 10 and the second substrate 20 to be hydrogen bonded via the hydroxyl groups.

[0034] As shown in Fig. 2, the second substrate 20 has a covering portion 25. The covering portion 25 is composed of an organic resin layer 24. The covering portion 25 is located more inward of the recess 110 than the side surface (inner surface 101) of the first substrate 10 that constitutes the inner surface 111 of the recess 110 (see Fig. 1), and covers part of the inner surface 101, as shown in Figs. 2 and 4. The covering portion 25 covers one end portion 102 on the second substrate 20 side, which is part of the inner surface 101.

[0035] A substrate containing an organic material is lighter than a substrate containing a ceramic material, and therefore, the wiring board 100 according to the present disclosure, which includes the first substrate 10 containing a ceramic material and the second substrate 20 containing an organic material, can be made lighter than a wiring board made only of a substrate containing a ceramic material.

[0036] Furthermore, the covering portion 25, which is a part of the second substrate 20, covers the inner surface 101 of the first substrate 10 that constitutes the inner surface 111 of the recess 110, thereby ensuring a wider bonding area between the first substrate 10 and the second substrate 20 compared to when the second substrate 20 does not have the covering portion 25. This improves bonding reliability.

[0037] 5, the covering portion 25 is positioned around the entire periphery of the recess 110. This ensures a wider bonding area between the first substrate 10 and the second substrate 20. This further improves bonding reliability.

[0038] The second base material 20 may also contain a black organic material. In this case, carbon or other pigments may be added to the organic material. This has the advantage of suppressing light reflection when an image sensor is mounted as the semiconductor element 310 (see FIG. 7 ) and hiding discoloration of the second base material 20 over time.

[0039] 2 , the recess 110 is located across the second substrate 20 and the first substrate 10. The recess 110 penetrates at least the second substrate 20. Therefore, the recess 110 may have a bottom or may not have a bottom, that is, may include a through hole that penetrates the second substrate 20 and the first substrate 10 in the thickness direction of the wiring substrate 100. As a result, the reduction in substrate strength due to the recess 110 being a through hole can be reduced by including the first substrate 10 formed of the ceramic layer 14.

[0040] 2 , the first wiring 30 is located inside the first substrate 10 and extends from one of the first surface 11 and the second surface 12 to the other. Note that "extending" here does not necessarily mean extending the shortest distance. For example, the first wiring 30 may have a portion (wiring layer 32) that extends along the first surface 11.

[0041] The first wiring 30 may have a plurality of vias 31 and one or more wiring layers 32. The vias 31 penetrate one or more ceramic layers 14. The wiring layers 32 are located between adjacent ceramic layers 14 and electrically connect the plurality of vias 31 together.

[0042] In this way, the wiring board 100 has the first wiring 30 on the first base material 10, and therefore has a higher degree of freedom in wiring design compared to conventional wiring boards that have wiring only on an organic resin substrate. On the other hand, when a configuration is adopted in which wiring (first wiring 30 and second wiring 40) is provided on both the first base material 10 and the second base material 20, it is desirable to make the bond between the first base material 10 and the second base material 20 stronger so as to prevent misalignment between the first wiring 30 and the second wiring 40.

[0043] 2 shows an example in which the first wiring 30 has the wiring layer 32, but the first wiring 30 does not necessarily have to have the wiring layer 32. Furthermore, the first wiring 30 may have a wiring layer located on the surface (first surface 11 or second surface 12) of the first base material 10.

[0044] The second wiring 40 is located inside the second base material 20 and extends from one of the third surface 21 and the fourth surface 22 to the other. Note that "extending" here does not necessarily mean extending the shortest distance. The second wiring 40 may be electrically connected to the first wiring 30 at the interface, which is the bonding surface between the first base material 10 and the second base material 20.

[0045] The second wiring 40 may have a plurality of vias 41 and one or more wiring layers 42. The vias 41 penetrate one or more organic resin layers 24. The wiring layers 42 are located between adjacent organic resin layers 24 and electrically connect the plurality of vias 41 to one another. The second wiring 40 may also have a wiring layer (land) located on the fourth surface 22 of the second substrate 20.

[0046] The first wiring 30 and the second wiring 40 may be, for example, metal conductors made of copper or silver. For example, both the first wiring 30 and the second wiring 40 may be metal conductors made of copper. Also, both the first wiring 30 and the second wiring 40 may be metal conductors made of silver. Also, one of the first wiring 30 and the second wiring 40 may be a metal conductor made of copper, and the other may be a metal conductor made of silver.

[0047] By making all of the first wiring 30 and the second wiring 40 metal conductors made of copper or silver, it is possible to obtain higher electrical characteristics than when, for example, one of the first wiring 30 and the second wiring 40 is made of a metal conductor other than copper or silver.

[0048] Of the first wiring 30 and the second wiring 40, only the first wiring 30 may contain a glass component. In this case, the first wiring 30 is firmly bonded to the first substrate 10, which also contains a glass component, via the glass component. Specifically, the glass component contained in the first wiring 30 is integrated with the glass component contained in the first substrate by firing. This integrated glass component hardens while entering the gaps between the multiple metal particles that make up the first wiring 30, thereby generating an anchor effect. The first wiring 30 is firmly bonded to the first substrate 10 due to this anchor effect. This can increase the rigidity of the first substrate 10.

[0049] Furthermore, when the first wiring 30 contains a glass component, the shrinkage rates of the first base material 10 and the first wiring 30 can be made uniform to some extent in the firing step during the manufacture of the wiring substrate 100. This makes it possible to make the positional deviation of the first wiring 30 less likely to occur.

[0050] The first wiring 30 may be formed, for example, by printing a conductive paste containing copper and glass components on a green sheet, which is the raw material for the ceramic layer 14, and then firing the green sheet simultaneously. Specifically, the conductive paste may contain, for example, copper powder, borosilicate glass powder, and silica particles. The first wiring 30 may be a metal conductor made of, for example, tungsten or molybdenum. As an example, the via 31 may be a metal conductor made of tungsten, and the wiring layer 32 may be a metal conductor made of molybdenum. Alternatively, the via 31 may be a metal conductor made of molybdenum, and the wiring layer 32 may be a metal conductor made of tungsten. Alternatively, both the via 31 and the wiring layer 32 may be metal conductors made of tungsten, or both the via 31 and the wiring layer 32 may be metal conductors made of molybdenum. The first wiring 30 may be a metal conductor made of, for example, copper or gold as a main component, and containing tungsten or molybdenum.

[0051] On the other hand, the second wiring 40 may be formed by copper plating, which allows the first wiring 30 and the second wiring 40 to have a configuration in which only the first wiring 30 contains a glass component.

[0052] 2 , in each of the organic resin layers 24 of the second substrate 20, the portion of the interface with the adjacent organic resin layer 24 that is located between the opening edge 112 of the recess 110 and the first substrate 10 is convexly curved in cross section. Also, in the wiring layer 42 of the second substrate 20, the portion that is located between the opening edge 112 of the recess 110 and the first substrate 10 is convexly curved in cross section. In this way, by rounding the corners of the second substrate 20, it is possible to reduce the possibility of damage due to collision with other components, etc.

[0053] 2 , the second wiring 40 is located in a region of the second substrate 20 in a plan view other than the region AR1 that overlaps with the inclined portion 16, which is defined by the dashed line in the figure. For example, if the first wiring 30 and the second wiring 40 were located in the region AR1 that overlaps with the inclined portion 16, there is a risk of interference with the first wiring 30 and the second wiring 40 when processing the first substrate 10 to provide the inclined portion 16. However, by locating the first wiring 30 and the second wiring 40 in a region other than the region AR1, interference with the first wiring 30 and the second wiring 40 can be structurally suppressed.

[0054] 2, the connecting conductor 50, which is an inter-substrate wiring layer, may be a conductor containing a glass component. The connecting conductor 50 is located between the first substrate 10 and the second substrate 20, and is joined to the first wiring 30 and the second wiring 40, electrically connecting the first wiring 30 and the second wiring 40. The wiring board 100 having such a connecting conductor 50 has a high degree of freedom in design.

[0055] The connection conductor 50 may be a conductor containing a glass component. The connection conductor 50 is located between the first substrate 10 and the second substrate 20, and electrically connects the first wiring 30 and the second wiring 40. The wiring board 100 having such a connection conductor 50 has a high degree of freedom in design.

[0056] 6 is a partial cross-sectional view showing an example of an inter-substrate wiring layer (connection conductor). As shown in FIG. 6, the connection conductor 50 may include a first metal layer 51 and a second metal layer 52. The metal constituting the first metal layer 51 may be a metal other than the metal constituting the second wiring 40. For example, the first metal layer 51 may be made of a first metal other than copper or silver. As an example, the first metal may be tungsten.

[0057] The metal constituting the second metal layer 52 may be the same as the metal constituting the second wiring 40. For example, the second metal layer 52 may be made of copper or silver. The second metal layer 52 is located between the first metal layer 51 and the second wiring 40. In this way, by including the second metal layer 52 in the connecting conductor 50, the bonding strength between the second wiring 40 and the connecting conductor 50 can be increased. In other words, the second wiring 40 and the second metal layer 52, which contain the same metal, are firmly bonded together by, for example, melting and integrating the metal material through heat treatment during the manufacturing process.

[0058] Furthermore, as will be described later, when the first metal layer 51 contains a glass component, the surface of the first metal layer 51 containing the glass component is relatively rough (uneven), and therefore the second metal layer 52 located on the first metal layer 51 is firmly bonded due to an anchor effect caused by the unevenness of the surface of the first metal layer 51. In this way, the second wiring 40 and the second metal layer 52 are firmly bonded, and the first metal layer 51 and the second metal layer 52 are firmly bonded, thereby increasing the bonding strength between the second wiring 40 and the connecting conductor 50.

[0059] The first metal layer 51 may also contain a glass component. Therefore, the connecting conductor 50 may be bonded to the first surface 11 of the first substrate 10 via the glass component. This glass component is contained in the connecting conductor 50 and the first substrate 10. This allows the connecting conductor 50 to be firmly bonded to the first substrate 10, which also contains a glass component, via the glass component, thereby increasing the bonding strength with the first substrate 10.

[0060] Of the first wiring 30 and the second wiring 40, only the first wiring 30 contains a glass component, so that the first wiring 30 is firmly bonded to the connection conductor 50, which also contains a glass component, via the glass component, thereby stabilizing the physical connection between the first wiring 30 and the connection conductor 50.

[0061] The connecting conductor 50 may have a shape that is wider in the direction along the first surface 11 than the via 41 of the second wiring 40 that is in direct contact with the connecting conductor 50. This makes it easier to align the connecting conductor 50 with the via 41 of the second wiring 40, thereby improving the yield of the wiring substrate 100.

[0062] <Semiconductor Device> Fig. 7 is a perspective view showing an example of the configuration of a semiconductor device according to an embodiment. As shown in Fig. 7, the semiconductor device 300 includes a wiring substrate 100 and a semiconductor element 310. The semiconductor element 310 is mounted on the wiring substrate 100. In the example shown in Fig. 7, the semiconductor element 310 is mounted on the second surface 12 of the first base material 10 in the wiring substrate 100. The semiconductor element 310 is positioned so as to face the open end of the recess 110, which is a through-hole.

[0063] In the semiconductor device 300, the wiring substrate 100 can be made lighter than a wiring substrate made only of a ceramic substrate. Furthermore, the covering portion 25, which is a part of the second substrate 20, covers one end 102 of the inner surface 101 of the first substrate 10, which constitutes the inner surface 111 of the recess 110 (see FIG. 1 ). This ensures a wider bonding area between the first substrate 10 and the second substrate 20 than when the second substrate 20 does not have the covering portion 25. This improves bonding reliability.

[0064] The present disclosure has been described in detail above, but the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible within the scope that does not deviate from the gist of the present disclosure.

[0065] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0066] The present technology can also be configured as follows. (1) A wiring board comprising: a first base material including a ceramic; a second base material including an organic material and bonded to the first base material; a recess positioned across the second base material and penetrating at least the second base material; and wiring positioned inside the second base material, wherein the second base material is positioned more inward of the recess than a side surface of the first base material that forms an inner surface of the recess, and has a covering portion that covers a portion of the side surface. (2) The wiring board according to (1), wherein the covering portion is positioned around the entire periphery of the recess. (3) The wiring board according to (1) or (2), wherein the first base material has a first surface and a second surface opposite the first surface, the second base material has a third surface bonded to the first surface and a fourth surface opposite the third surface, and a portion of the fourth surface that is located at an edge of an opening of the recess is convexly curved in a cross-sectional view. (4) The wiring board according to (3), wherein the second substrate has a plurality of organic resin layers, the wiring has a plurality of vias penetrating one or more of the organic resin layers, and a wiring layer electrically connecting the plurality of vias and located between adjacent organic resin layers, wherein a portion of the interface between each of the plurality of organic resin layers and an adjacent organic resin layer that is located between an edge of the opening of the recess and the first substrate is convexly curved in a cross-sectional view, and a portion of the wiring layer that is located between an edge of the opening of the recess and the first substrate is convexly curved in a cross-sectional view. (5) The wiring board according to any one of (1) to (4), wherein the recess is a through hole that penetrates the second substrate and the first substrate. (6) The wiring board according to any one of (1) to (5), wherein the first substrate includes a ceramic containing a hydroxyl group as a material, the second substrate includes an epoxy-based resin as a material, and the first substrate and the second substrate are chemically bonded by the hydroxyl group. (7) The wiring board according to any one of (1) to (6), wherein a part of the outer peripheral surface of the first base material is exposed from the second base material.(8) The wiring board according to any one of (1) to (7), which has an inter-substrate wiring layer located between the first substrate and the second substrate, and the wiring is bonded to the inter-substrate wiring layer. (9) The wiring board according to (8), wherein the inter-substrate wiring layer includes: a first metal layer made of a first metal that is a metal other than a metal that constitutes the wiring; and a second metal layer located between the first metal layer and the wiring and made of a second metal that is a metal that constitutes the wiring. (10) The wiring board according to (9), wherein the first metal layer contains a glass component. (11) The wiring board according to any one of (1) to (10), wherein the first base material has a first surface to be bonded to the second base material and a second surface located opposite the first surface, the first surface having a central portion and an inclined portion located on an outer edge side of the central portion and inclined toward the second surface as it approaches the outer edge, and the wiring is located in a region of the second base material other than a region overlapping with the inclined portion in a plan view. (12) The wiring board according to any one of (1) to (11), wherein the second base material contains a black-based organic material as a material. (13) A semiconductor device comprising: the wiring board according to any one of (1) to (12); and a semiconductor element mounted on the wiring board.

[0067] REFERENCE SIGNS LIST 10 First substrate 11 First surface 12 Second surface 13 First side surface 15 Central portion 16 Inclined portion 17 Side 20 Second substrate 21 Third surface 22 Fourth surface 23 Second side surface 25 Covering portion 30 First wiring 40 Second wiring 50 Inter-substrate wiring layer 100 Wiring substrate 110 Recess 111 Inner surface 112 Opening edge portion 300 Semiconductor device 310 Semiconductor element

Claims

1. A wiring board comprising: a first base material containing a ceramic; a second base material containing an organic material and bonded to the first base material; a recess located across the second base material and the first base material and penetrating at least the second base material; and wiring located inside the second base material, wherein the second base material is located further inward from the recess than a side surface of the first base material that constitutes the inner surface of the recess, and has a covering portion covering a part of the side surface.

2. The wiring board according to claim 1, wherein the covering portion is positioned around the entire periphery of the recess.

3. The wiring board according to claim 1, wherein the first substrate has a first surface and a second surface located opposite the first surface, the second substrate has a third surface joined to the first surface and a fourth surface located opposite the third surface, and a portion of the fourth surface located at the edge of the opening of the recess is convexly curved in a cross-sectional view.

4. The wiring board according to claim 3, wherein the second substrate has a plurality of organic resin layers, the wiring has a plurality of vias penetrating one or more of the organic resin layers, and a wiring layer electrically connecting the plurality of vias and located between adjacent organic resin layers, and in each of the plurality of organic resin layers, a portion of the interface with the adjacent organic resin layer that is located between the edge of the opening of the recess and the first substrate is convexly curved in cross section, and a portion of the wiring layer that is located between the edge of the opening of the recess and the first substrate is convexly curved in cross section.

5. The wiring board according to claim 1, wherein the recess is a through hole penetrating the second base material and the first base material.

6. The wiring board according to claim 1, wherein the first base material includes a ceramic material containing hydroxyl groups, the second base material includes an epoxy resin material, and the first base material and the second base material are chemically bonded together by hydroxyl groups.

7. The wiring board according to claim 1, wherein a portion of the outer peripheral surface of the first base material is exposed from the second base material.

8. The wiring board according to claim 1, further comprising an inter-substrate wiring layer located between the first substrate and the second substrate, and the wiring is bonded to the inter-substrate wiring layer.

9. The wiring board according to claim 8, wherein the inter-substrate wiring layer includes: a first metal layer made of a first metal other than the metal constituting the wiring; and a second metal layer located between the first metal layer and the wiring and made of a second metal other than the metal constituting the wiring.

10. The wiring board according to claim 9, wherein the first metal layer contains a glass component.

11. The wiring board described in claim 1, wherein the first substrate has a first surface to be joined to the second substrate and a second surface located opposite the first surface, the first surface has a central portion and an inclined portion located toward the outer edge from the central portion and inclined toward the second surface as it approaches the outer edge, and the wiring is located in an area of ​​the second substrate other than the area that overlaps with the inclined portion in a planar view.

12. The wiring board according to claim 1, wherein the second base material contains a black-based organic material as a material.

13. A semiconductor device comprising: a wiring board according to any one of claims 1 to 12; and a semiconductor element mounted on the wiring board.

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