Wiring board and semiconductor device

Abstract

To increase the degree of freedom of wiring.SOLUTION: A wiring board has: a first base material that has a first surface and a second surface located on the opposite side of the first surface, and that uses a ceramic composite material including a glass component; a second base material that has a third surface and a fourth surface located on the opposite side of the third surface, and that contains an organic component as a main component; first wiring that is located inside the first base material and extends from the first surface to the second surface; second wiring that is located inside the second base material and extends from the third surface to the fourth surface; and a plurality of convex bodies that project from the first surface and penetrate into the second base material. The third surface of the second base material is joined to the first surface of the first base material. The coefficient of thermal expansion of the second base material in a direction along the first surface is higher than that of the first base material. The first wiring and the second wiring are electrically connected to each other on a joint surface of the first base material and the second base material. The convex bodies include a glass component and are joined to the first base material with the glass component.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] 2. Description of the Related Art There has been proposed a wiring board in which an organic resin substrate on which wiring is formed is laminated on a ceramic substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-207977 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, since the wiring is formed only on the organic resin substrate, there is still room for improvement in terms of increasing the degree of freedom in designing the wiring.

[0005] The present disclosure provides a technique that can increase the degree of freedom in wiring design. [Means for solving the problem]

[0006] A wiring board according to an embodiment of the present disclosure includes a first substrate, a second substrate, a first wiring, a second wiring, and a plurality of convex bodies. The first substrate has a first surface and a second surface located opposite to the first surface, and is a substrate using a ceramic composite material containing a glass component. The second substrate has a third surface and a fourth surface located opposite to the third surface, and is a substrate mainly composed of an organic component. The first wiring is located inside the first substrate and extends from the first surface to the second surface. The second wiring is located inside the second substrate and extends from the third surface to the fourth surface. The plurality of convex bodies protrude from the first surface and enter the inside of the second substrate. The third surface of the second substrate is bonded to the first surface of the first substrate. The second substrate has a higher coefficient of thermal expansion in a direction along the first surface than the first substrate. The first wiring and the second wiring are electrically connected at a bonding surface between the first substrate and the second substrate. The convex body includes a glass component and is bonded to the first base material by the glass component. Effect of the Invention

[0007] According to the present disclosure, it is possible to increase the degree of freedom in wiring design. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the configuration of a wiring board according to the first embodiment. [Diagram 2] FIG. 2 is an enlarged cross-sectional view showing an example of the configuration of the H1 portion shown in FIG. [Diagram 3] FIG. 3 is an enlarged cross-sectional view showing an example of the configuration of the H2 portion shown in FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view showing another example of the convex body. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing another example of the convex body. [Figure 6] FIG. 6 is a schematic cross-sectional view showing another example of the convex body. [Figure 7] FIG. 7 is an enlarged cross-sectional view showing another example of the configuration of the H1 portion shown in FIG. [Figure 8] FIG. 8 is a schematic enlarged view showing another example of a recess. [Figure 9] FIG. 9 is a schematic vertical cross-sectional view of a via according to the first embodiment. [Figure 10] FIG. 10 is a schematic cross-sectional view of a via according to the first embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing an example of the configuration of the semiconductor device according to the first embodiment. [Figure 12] FIG. 12 is a cross-sectional view showing an example of the configuration of a wiring board according to the second embodiment. [Figure 13] FIG. 13 is a cross-sectional view showing an example of the configuration of a wiring board according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a detailed description will be given of a form for carrying out a wiring board and a semiconductor device according to the present disclosure (hereinafter, referred to as an "embodiment") with reference to the drawings. Note that the present disclosure is not limited to the embodiment. In addition, each embodiment can be appropriately combined within a range that does not cause a contradiction in the processing contents. In addition, the same parts in each of the following embodiments are given the same reference numerals, and duplicated explanations will be omitted.

[0010] In addition, in the embodiments described below, expressions such as "orthogonal" or "vertical" may be used, but these expressions do not necessarily mean "orthogonal" or "vertical" strictly. In other words, the above expressions allow for deviations due to, for example, manufacturing precision, installation precision, etc.

[0011] In addition, in order to make the explanation easier to understand, each of the drawings referred to below may show an orthogonal coordinate system that defines mutually perpendicular X-axis, Y-axis, and Z-axis directions and defines the thickness direction of the wiring board as the Z-axis direction.

[0012] First Embodiment Fig. 1 is a cross-sectional view showing an example of the configuration of a wiring board according to the first embodiment. As shown in Fig. 1, wiring board 100 according to the first embodiment includes a first substrate 1 and a second substrate 2. Wiring board 100 is a laminate of first substrate 1 and second substrate 2. Wiring board 100 also includes a first wiring 3 and a second wiring 4.

[0013] <First base material> The first substrate 1 may be formed using a ceramic composite material containing a glass component, so-called glass ceramic. The glass ceramic may be any of the following: a composite of a glass phase and ceramic particles, a composite of a glass phase and a crystalline phase formed by crystallizing a part of the glass phase, a form in which ceramic particles exist in a glass phase, and a form in which a glass phase exists at the grain boundaries between ceramic particles.

[0014] For example, the first base material 1 may be made of LTCC (Low Temperature Co-fired Ceramics). When LTCC is used as the first base material 1, a low melting point metal such as copper or silver, which has a relatively low electrical resistance, can be used as wiring.

[0015] The first base material 1 may contain a ceramic filler as ceramic particles. For example, alumina (aluminum oxide), calcium titanate, magnesium titanate, or the like can be used as the ceramic filler. In particular, the first base material 1 containing alumina has high rigidity.

[0016] The first substrate 1 has a first surface 101 and a second surface 102 located opposite to the first surface 101. The first substrate 1 may be a plate-like body having the first surface 101 and the second surface 102 as main surfaces.

[0017] In the first embodiment, the first base material 1 has a plurality of ceramic layers 10. The plurality of ceramic layers 10 are laminated along the thickness direction (here, the Z-axis direction) of the first base material 1. By forming the first base material 1 using the plurality of ceramic layers 10 in this manner, it is possible to obtain a first base material 1 having a wiring layer 32 therein.

[0018] There is a high degree of freedom in designing the wiring board 100 having such a first base material 1. In addition, by forming the first base material 1 using a plurality of ceramic layers 10, it is possible to manufacture the first base material 1 while checking whether the first wiring 3 is properly formed for each layer, and therefore it is possible to improve the yield of the first base material 1.

[0019] In the example shown in Fig. 1, the first substrate 1 has three ceramic layers 10, but the number of ceramic layers 10 is not limited to three. The number of ceramic layers 10 may be two or four or more. In addition, the first substrate 1 does not necessarily have to have a multi-layer structure. An example in which the first substrate 1 is a single layer will be described later.

[0020] <Second base material> The second substrate 2 is a substrate mainly composed of an organic component. The organic component 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.

[0021] The organic resin may be, for example, polytetrafluoroethylene (PTFE) or other fluororesins or polyphenylene ether resins. The second base material 2 may contain components other than the organic resin. In the present disclosure, the main component is, for example, a material that occupies 50% by mass or more of the material.

[0022] The second base material 2 has a third surface 103 and a fourth surface 104 located opposite the third surface 103. The second base material 2 may be a plate-like body having the third surface 103 and the fourth surface 104 as main surfaces.

[0023] The second base material 2 has a third surface 103 bonded to the first surface 101 of the first base material 1. On a fourth surface 104 of the second base material 2, a semiconductor element 9 (see FIG. 11) is placed.

[0024] The second base material 2 has a plurality of organic resin layers 20. The plurality of organic resin layers 20 are laminated along the thickness direction (here, the Z-axis direction) of the second base material 2. By configuring the second base material 2 using the plurality of organic resin layers 20, it is possible to obtain a second base material 2 having a wiring layer 42 therein. A wiring board 100 having such a second base material 2 has a high degree of freedom in design.

[0025] 1, the second base material 2 has three organic resin layers 20, but the number of the organic resin layers 20 is not limited to three. The number of the organic resin layers 20 may be two, or four or more.

[0026] 1, the second base material 2 is bonded to one main surface (here, the first surface 101) of the first base material 1, but the wiring board 100 may have the second base material 2 on both main surfaces (the first surface 101 and the second surface 102) of the first base material 1. An example of this configuration will be described later.

[0027] The second substrate 2, which is mainly composed of an organic component, is easier to form a fine wiring pattern on than an inorganic substrate. On the other hand, the first substrate 1, which is made of ceramic, is more rigid than the second substrate 2. In addition, the second substrate 2, which is mainly composed of an organic component, is less dense than the first substrate 1.

[0028] The wiring board 100 according to the first embodiment can increase rigidity while realizing finer wiring and narrower pitch by combining the first base material 1 and the second base material 2. Since the larger the board, the more likely it is that the board will warp, the configuration of the wiring board 100 in which the first base material 1 compensates for the low rigidity of the second base material 2 is particularly useful for increasing the size of the board.

[0029] Furthermore, wiring board 100 according to the first embodiment can be made lighter than a wiring board made only of an inorganic substrate because it includes second base material 2, which has a lower density than an inorganic substrate.

[0030] <First wiring and second wiring> The first wiring 3 is located inside the first base material 1, and extends from one of the first surface 101 and the second surface 102 to the other. Note that "extending" here does not necessarily mean extending the shortest distance. For example, the first wiring 3 may have a portion (wiring layer 32) that extends along the first surface 101.

[0031] The first wiring 3 has a plurality of vias 31 and one or more wiring layers 32. The vias 31 penetrate one or more ceramic layers 10. The wiring layers 32 are located between adjacent ceramic layers 10 and electrically connect the plurality of vias 31 to each other.

[0032] In this way, since the wiring board 100 has the first wiring 3 on the first base material 1, the degree of freedom in wiring design is high 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 (the first wiring 3 and the second wiring 4) is provided on both the first base material 1 and the second base material 2, it is desirable to make the bond between the first base material 1 and the second base material 2 stronger so that misalignment between the first wiring 3 and the second wiring 4 does not occur.

[0033] 1 shows an example in which the first wiring 3 has the wiring layer 32, but the first wiring 3 does not necessarily have to have the wiring layer 32. In addition, the first wiring 3 may have a wiring layer located on the surface (first surface 101 or second surface 102) of the first base material 1.

[0034] The second wiring 4 is located inside the second base material 2, and extends from one of the third surface 103 and the fourth surface 104 to the other. Note that "extending" here does not necessarily mean extending the shortest distance. The second wiring 4 may be electrically connected to the first wiring 3 at the joint surface between the first base material 1 and the second base material 2.

[0035] The second wiring 4 has a plurality of vias 41 and one or more wiring layers 42. The vias 41 penetrate one or more organic resin layers 20. The wiring layers 42 are located between adjacent organic resin layers 20, and electrically connect the plurality of vias 41 to each other. The second wiring 4 may have a wiring layer (land) located on the fourth surface 104 of the second base material 2.

[0036] The first wiring 3 and the second wiring 4 may be, for example, a metal conductor mainly composed of copper or silver. For example, both the first wiring 3 and the second wiring 4 may be a metal conductor mainly composed of copper. Also, both the first wiring 3 and the second wiring 4 may be a metal conductor mainly composed of silver. Also, one of the first wiring 3 and the second wiring 4 may be a metal conductor mainly composed of copper, and the other may be a metal conductor mainly composed of silver.

[0037] By making all of the first wiring 3 and the second wiring 4 out of metal conductors whose main component is copper or silver, it is possible to obtain higher electrical characteristics than, for example, when one of the first wiring 3 and the second wiring 4 is out of a metal conductor other than copper or silver.

[0038] Of the first wiring 3 and the second wiring 4, only the first wiring 3 may contain a glass component. In this case, the first wiring 3 is firmly bonded to the first base material 1, which also contains a glass component, via the glass component. This makes it possible to increase the rigidity of the first base material 1.

[0039] Furthermore, in the firing step when manufacturing wiring board 100, the shrinkage rates of first base material 1 and first wiring 3 can be made uniform to a certain extent, so that positional deviation of first wiring 3 can be made less likely to occur.

[0040] The first wiring 3 may be formed, for example, by printing a conductive paste containing copper and glass components on a green sheet that is the raw material of the ceramic layer 10, and firing the green sheet simultaneously with the green sheet. Specifically, the conductive paste may contain, for example, copper powder, borosilicate glass powder, and silica particles.

[0041] On the other hand, the second wiring 4 may be formed by a copper plating process. This allows a configuration in which, of the first wiring 3 and the second wiring 4, only the first wiring 3 contains a glass component.

[0042] The second wiring 4 may be electrically and thermally connected to the semiconductor element 9 placed on the fourth surface 104 of the second base material 2. By thermally connecting the second wiring 4, which is mainly composed of copper or silver having a relatively high thermal conductivity, to the semiconductor element 9 serving as a heat source, the heat generated from the semiconductor element 9 can be efficiently dissipated via the second wiring 4 and the first wiring 3.

[0043] <Physical properties of the first and second substrates> The thermal expansion coefficient of the first base material 1 in a direction along the first surface 101 (here, the X-axis direction) may be smaller than the thermal expansion coefficient of the second base material 2 in the direction along the first surface 101. Since the second base material 2 is bonded to the first base material 1, with the above configuration, when the second base material 2 attempts to thermally deform due to a temperature change, the first base material 1 restrains the second base material 2, thereby making it possible to reduce the thermal deformation of the second base material 2.

[0044] As an example, the thermal expansion coefficient of the first base material 1 in the direction along the first surface 101 is 3.4×10 -6 / ℃ or more and 12.3×10 -6 / °C or less. The thermal expansion coefficient of the second base material 2 in the direction along the first surface 101 may be 20×10 -6 / ℃ or more and 60×10 -6 / °C or less.

[0045] The thermal expansion coefficient of the first base material 1 is 3.4×10 -6 / ℃ or more and 8.2×10 -6 / °C or less. In this case, it is possible to more suitably reduce the thermal deformation of second base material 2. Furthermore, since the thermal expansion coefficient in this case is relatively close to the thermal expansion coefficient of a general semiconductor element, it is possible to make the degree of thermal deformation of the semiconductor element and wiring board 100 uniform to some extent during operation of the semiconductor element.

[0046] Therefore, during operation of semiconductor element 9 mounted on wiring board 100, the occurrence of cracks or the like in wiring board 100 due to the difference in the amount of thermal deformation between semiconductor element 9 and wiring board 100 can be reduced.

[0047] The thermal expansion coefficient of the first base material 1 is 10.4×10 -6 / ℃ or more and 12.3×10 -6 / °C or less. In this case, the thermal expansion coefficient is the thermal expansion coefficient of a general motherboard (15 to 18 × 10 -6 / ℃), it is possible to improve the reliability of mounting on the motherboard.

[0048] The thermal conductivity of the first base material 1 may be higher than the thermal conductivity of the second base material 2. For example, the thermal conductivity of the first base material 1 may be 1.9 W / mK or more and 4.3 W / mK or less. Furthermore, the thermal conductivity of the second base material 2 may be 0.1 W / mK or more and 1.5 W / mK or less.

[0049] The Young's modulus of the first base material 1 may be higher than that of the second base material 2. In this configuration, the first base material 1 is more likely to bend than when a conventional insulating layer having a high Young's modulus (400 to 1000 GPa) such as alumina is applied. Therefore, for example, when a force is applied to the semiconductor element 9 mounted on the wiring board 100, the first base material 1 bends, thereby reducing the load on the semiconductor element 9.

[0050] For example, the Young's modulus of the first substrate 1 may be 74 GPa or more and 178 GPa or less, and the Young's modulus of the second substrate 2 may be 3.5 GPa or more and 9.0 GPa or less.

[0051] The Young's modulus of the first base material 1 may be not less than 103 GPa and not more than 178 GPa. With this configuration, the second base material 2 and the semiconductor element 9 are less susceptible to the effects of deformation of the motherboard on which the wiring substrate 100 is mounted.

[0052] The Young's modulus of the first base material 1 may be 74 GPa or more and 95 GPa or less. With this configuration, when the semiconductor element 9 itself is prone to bending, for example, when the semiconductor element 9 is thin or has a large area, the wiring board 100 can easily follow the bending of the semiconductor element 9.

[0053] The glass transition point of the first base material 1 may be 600° C. or higher. In such a configuration, the glass transition point of the first base material 1 is several hundred degrees higher than that of the second base material 2, so that the heat resistance of the entire wiring board 100 can be improved.

[0054] The second substrate 2 may have a relative dielectric constant of 3.3 or more and 3.45 or less. The first substrate 1 may have a relative dielectric constant of 5.2 or more and 7.7 or less. By using a substrate having a relative dielectric constant close to that of the second substrate 2 as the first substrate 1, it is possible to obtain a wiring board 100 having excellent impedance matching in the wiring in the stacking direction.

[0055] The dielectric tangent of the second substrate 2 may be 0.012 or more and 0.0058 or less. The dielectric tangent of the first substrate 1 may be 0.0005 or more and 0.0036 or less. In this configuration, the transmission characteristics of the entire wiring substrate 100 can be improved compared to when an organic resin substrate is used as the core layer instead of the first substrate 1.

[0056] <Joint conductor> 1, the wiring board 100 may include a bonding conductor 5. The bonding conductor 5 may be a conductor containing a glass component. The bonding conductor 5 is located between the first substrate 1 and the second substrate 2, and electrically connects the first wiring 3 and the second wiring 4. The wiring board 100 having such a bonding conductor 5 has a high degree of freedom in design.

[0057] The joining conductor 5 may be wider than the via 41 of the second wiring 4 that is in direct contact with the joining conductor 5 in the direction along the first surface 101. This makes it easier to align the joining conductor 5 with the via 41 of the second wiring 4, thereby improving the yield of the wiring board 100.

[0058] The joining conductor 5 may be joined to the first surface 101 of the first base material 1 by a glass component. Such a glass component is contained in the joining conductor 5 and the first base material 1. In this way, the joining conductor 5 is firmly joined to the first base material 1, which also contains a glass component, via the glass component.

[0059] <Convex body> Fig. 2 is an enlarged cross-sectional view showing an example of the configuration of portion H1 shown in Fig. 1. As shown in Fig. 2, wiring substrate 100 (see Fig. 1) has a plurality of convex bodies 6. The plurality of convex bodies 6 protrude from first surface 101 of first substrate 1 toward second substrate 2, and penetrate into second substrate 2.

[0060] Thus, according to the wiring board 100, the anchor effect caused by the multiple convex bodies 6 penetrating into the second base material 2 can increase the bonding strength between the first base material 1 and the second base material 2.

[0061] By firmly bonding the second substrate 2 to the first substrate 1, the second substrate 2 is restrained by the first substrate 1, and thermal deformation of the second substrate 2 is reduced. This makes it possible to prevent misalignment between the first wiring 3 and the second wiring 4. Furthermore, by bonding the first substrate 1 and the second substrate 2 using a plurality of convex bodies 6, the need to bond the first substrate 1 and the second substrate 2 using, for example, a bonding material or the like is reduced.

[0062] The convex body 6 contains a glass component and is bonded to the first substrate 1 by the glass component.

[0063] In this way, the multiple convex bodies 6 are firmly bonded to the first base material 1 containing a glass component. This makes the bond between the first base material 1 and the second base material 2 stronger, making it more difficult for the first base material 1 and the second base material 2 to become misaligned. This stabilizes the physical connection between the first wiring 3 and the second wiring 4.

[0064] Furthermore, the convex body 6 firmly bonded to the first base material 1 is unlikely to come off the first base material 1 even if it is repeatedly subjected to a load caused by deformation of the second base material 2. Therefore, according to the wiring board 100, the first base material 1 and the second base material 2 can be maintained in a firmly bonded state for a long period of time.

[0065] Fig. 3 is an enlarged cross-sectional view showing an example of the configuration of portion H2 shown in Fig. 2. As shown in Fig. 3, the convex body 6 includes a base portion 61 mainly composed of a glass component, and a plurality of ceramic particles 62.

[0066] The base 61 may have a tapered shape. Specifically, in a cross section perpendicular to the first surface 101 of the first substrate 1, the width of the tip 61a of the base 61 may be narrower than the width of the base end 61b of the base 61. As described later, a plurality of ceramic particles 62 are located on the surface of the base 61, but if the base 61 has a tapered shape, the convex body 6 also has a tapered shape when viewed as a whole.

[0067] The convex body 6 having a tapered shape is likely to penetrate into the second substrate 2, and therefore is likely to produce an anchor effect. In addition, if the convex body 6 has a tapered shape, the convex body 6 may not penetrate into the second substrate 2, and a space may be generated between the first substrate 1 and the second substrate 2. Such a space may deteriorate the bonding between the first substrate 1 and the second substrate 2.

[0068] In contrast, in wiring board 100 having tapered convex bodies 6, convex bodies 6 easily enter inside second base material 2, so that a space is unlikely to be generated between first base material 1 and second base material 2.

[0069] In a cross section perpendicular to the first surface 101, the side surface 61c connecting the tip end 61a and the base end 61b of the convex body 6 may be curved in a concave shape. The convex body 6 having such a configuration is more likely to penetrate into the second base material 2 than, for example, a convex body having a convex side surface.

[0070] The tip 61a of the convex body 6 may be sharp. The convex body 6 with the sharp tip 61a easily penetrates into the second substrate 2. When the convex body 6 is observed with an optical microscope or an electron microscope at a magnification of 5000 times, if no flat surface is confirmed at the tip 61a, the tip 61a of the convex body 6 is sharp.

[0071] The height of the convex body 6 (the length in the Z-axis direction) may be, for example, not less than 0.0001 mm and not more than 0.001 mm.

[0072] The content of the glass component in the convex body 6 may be higher than the content of the glass component in the first substrate 1. With this configuration, the workability of the convex body 6 is improved compared to when the convex body 6 is made of other materials, such as ceramics, and it is therefore easier to make the convex body 6 in a desired shape (for example, a tapered shape).

[0073] The plurality of ceramic particles 62 are located on the surface of the base 61. In this case, fine irregularities are formed on the surface of the base 61 by the ceramic particles 62. The second base material 2 penetrates into the fine irregularities formed by the ceramic particles 62, making it more difficult for the convex body 6 to come off the second base material 2. Therefore, the convex body 6 having the plurality of ceramic particles 62 has an even higher anchor effect.

[0074] Some of the ceramic particles 62 may be located inside the base 61. In this case, the ceramic particles 62 may be located more on the surface of the base 61 than inside the base 61. With this configuration, the anchor effect can be enhanced while maintaining the strength of the base 61, which is mainly composed of a glass component.

[0075] In addition, the term "ceramic particles 62 located on the surface of the base 61" refers to ceramic particles 62 at least a portion of which is exposed from the base 61 in a cross-sectional view. Therefore, for example, ceramic particles 62 a portion of which is embedded inside the base 61 also falls under the category of "ceramic particles 62 located on the surface of the base 61."

[0076] Furthermore, the phrase "multiple ceramic particles 62 are located more on the surface of base 61 than inside base 61" may mean, for example, that in cross-sectional view, the number of ceramic particles 62 located on the surface of base 61 is greater than the number of ceramic particles 62 located inside base 61.

[0077] The particle size of the ceramic particles 62 may be, for example, not less than 0.05 μm and not more than 1.00 μm.

[0078] When the first substrate 1 contains a ceramic filler, the ceramic particles 62 of the convex body 6 may be the same component as the filler contained in the first substrate 1. That is, the ceramic particles 62 of the convex body 6 may be filler that is incorporated into the glass component of the base 61 and is thereby positioned in the convex body 6. This makes it possible to easily provide the convex body 6 with an uneven shape.

[0079] The convex body 6 can be formed, for example, by sparsely applying a paste containing glass powder and ceramic particles to the first surface 101 of the first substrate 1, drying it, and then performing a heat treatment. In this case, the shape or size of the base 61 can be controlled by the way in which the paste is applied.

[0080] In addition, the convex body 6 may be formed by applying a paste containing, for example, glass powder and ceramic particles to the entire surface of the first surface 101 of the first substrate 1, drying it, heat treating it, and then removing the glassy layer formed on the first surface 101 while leaving behind the portion that will become the convex body 6.

[0081] Alternatively, the convex body 6 may be formed by applying a paste of glass powder onto a ceramic green sheet that serves as the first substrate 1, drying it, heat treating it, and then removing the glassy layer formed on the first surface 101 while leaving behind the portion that will become the convex body 6.

[0082] 4 to 6 are schematic cross-sectional views showing another example of the convex body 6. In the example of Fig. 3 described above, the base 61 of the convex body 6 extends in a direction perpendicular to the first surface 101 (here, the Z-axis direction).

[0083] 4, the base 61 may extend obliquely with respect to the direction perpendicular to the first surface 101. With this configuration, even if a force perpendicular to the first surface 101 is applied to the second substrate 2, the second substrate 2 is unlikely to come off from the first substrate 1.

[0084] 4, the tip portions 61a of the multiple protrusions 6 may extend in different directions. With this configuration, the anchor effect can be generated in various directions, making it more difficult for the second substrate 2 to come off from the first substrate 1.

[0085] 5, in the present disclosure, a plurality of (here, two) convex bodies 6 may be connected to each other at the base end portion 61b. In such a configuration, the strength of the convex body 6 can be further increased.

[0086] Also, as shown in FIG. 6, in the present disclosure, the base portion 61 may have a flat surface at the tip portion 61a.

[0087] Fig. 7 is an enlarged cross-sectional view showing another example of the configuration of portion H1 shown in Fig. 1. As shown in Fig. 7, the first substrate 1 may have a plurality of recesses 111 on the first surface 101. In this case, the second substrate 2 may be recessed into the recesses 111. In such a configuration, the second substrate 2 recessed into the recesses 111 provides an anchor effect, and the first substrate 1 and the second substrate 2 can be bonded more firmly.

[0088] Fig. 8 is a schematic enlarged view showing another example of the recess 111. As shown in Fig. 8, the recess 111 may be formed so as to be continuous with the side surfaces 61c of two adjacent convex bodies 6 in a cross-sectional view. In such a configuration, the second substrate 2 enters one deep recess including the side surfaces 61c of the two convex bodies 6, and therefore the anchor effect is further enhanced.

[0089] Fig. 9 is a schematic vertical cross-sectional view of the via 31 according to the first embodiment. Fig. 10 is a schematic horizontal cross-sectional view of the via 31 according to the first embodiment.

[0090] 9 and 10, the wiring board 100 may have a diffusion layer 7 containing a metal component of the first wiring 3 between the via 31 of the first wiring 3 and the first base material 1. In such a configuration, the first wiring 3 and the first base material 1 are firmly connected through the diffusion layer 7 containing a metal component, so that the rigidity of the first base material 1 can be increased.

[0091] Furthermore, in the firing step when manufacturing wiring board 100, the shrinkage rates of first base material 1 and first wiring 3 can be made uniform to a certain extent, so that positional deviation of first wiring 3 can be made less likely to occur.

[0092] Furthermore, since the adhesion between the first substrate 1 and the first wiring 3 is increased, gaps that impede heat conduction are unlikely to occur between the first substrate 1 and the first wiring 3. In other words, gaps that impede heat conduction are unlikely to occur on the heat transfer path that runs through the fourth surface 104 (the surface on which the semiconductor element 9 is mounted) of the second substrate 2, the second wiring 4, the first wiring 3, and the first substrate 1 in this order. This allows the heat generated in the semiconductor element 9 to be efficiently released to the outside.

[0093] The diffusion layer 7 may be located only on the first base material 1 out of the first base material 1 and the second base material 2. In other words, the wiring board 100 may not have the diffusion layer 7 between the second base material 2 and the second wiring 4.

[0094] In this case, the effect of thermal deformation of second base material 2 is less likely to be transmitted to second wiring 4, making it possible to provide wiring board 100 that is resistant to temperature changes. Note that the present disclosure is not limited to this, and wiring board 100 may have a diffusion layer containing a metal component of second wiring 4 between second base material 2 and second wiring 4.

[0095] Furthermore, the second wiring 4 may have a smoother surface than the first wiring 3. In other words, the surface roughness of the second wiring 4 may be smaller than the surface roughness of the first wiring 3. With this configuration, the effect of thermal deformation of the second base material 2 is less likely to be transmitted to the second wiring 4, making it possible to provide a wiring board 100 that is more resistant to temperature changes.

[0096] The diffusion layer 7 may be located so as to cover the entire cylindrical via 31. That is, as shown in Fig. 10, the diffusion layer 7 may have an annular shape covering the periphery of the cylindrical via 31 in a cross-sectional view. The length of the diffusion layer 7 in the thickness direction of the first base material 1 (here, the Z-axis direction) may be the same as the length of the via 31 in the thickness direction of the first base material 1.

[0097] In this way, by positioning the diffusion layer 7 along the thickness direction of the first substrate 1 within the via 31, through which current flows along the thickness direction of the first substrate 1 (here, the Z-axis direction), a good conductive path can be formed by the diffusion layer 7 near the interface between the via 31 and the first substrate 1.

[0098] Therefore, this configuration can increase the interface conductivity of the via 31. In addition, the length of the diffusion layer 7 in the thickness direction of the first base material 1 is the same as the length of the via 31 in the thickness direction of the first base material 1, so that the interface conductivity of the via 31 can be increased.

[0099] Here, an example is shown in which the diffusion layer 7 is located around the via 31, but if the first wiring 3 has a wiring layer 32, the diffusion layer 7 may be located around the wiring layer 32.

[0100] <Semiconductor devices> Fig. 11 is a cross-sectional view showing an example of the configuration of a semiconductor device 300 according to the first embodiment. As shown in Fig. 11, the semiconductor device 300 has a wiring substrate 100 and a semiconductor element 9. The semiconductor element 9 is mounted on a fourth surface 104 of a second base material 2 of the wiring substrate 100.

[0101] The thermal expansion coefficient of the semiconductor element 9 may be lower than that of the second base material 2. In other words, the thermal expansion coefficient of the second base material 2 may be higher than that of the semiconductor element 9. In this case, when a temperature change occurs in the semiconductor device 300, the semiconductor element 9 may be damaged due to the difference in the amount of thermal deformation between the second base material 2 and the semiconductor element 9.

[0102] In contrast, in the wiring board 100, the second base material 2 is firmly bonded to the first base material 1, which has a lower coefficient of thermal expansion than the second base material 2, by the multiple convex bodies 6. As a result, the thermal deformation of the second base material 2 is reduced by the first base material 1, and the difference in the amount of thermal deformation between the second base material 2 and the semiconductor element 9 becomes smaller, so that the semiconductor element 9 is less susceptible to damage.

[0103] The thermal expansion coefficient here refers to the thermal expansion coefficient in a direction along first surface 101 of first base material 1, for example.

[0104] <Second embodiment> In the first embodiment described above, an example has been described in which the second base material 2 is located on only one of the main surfaces (first surface 101 and second surface 102) of the first base material 1 in the wiring board 100. However, the present invention is not limited to this, and the wiring board 100 may have a configuration in which the second base material 2 is located on both main surfaces of the first base material 1.

[0105] 12 is a cross-sectional view showing an example of the configuration of a wiring board 100 according to the second embodiment. As shown in FIG. 12, the wiring board 100 has a second base material 2 located on a second surface 102 of the first base material 1 in addition to a second base material 2 located on a first surface 101 of the first base material 1.

[0106] The second base material 2 located on the second surface 102 has, for example, a third surface 103 bonded to the second surface 102 of the first base material 1. Note that the second base material 2 may have a fourth surface 104 bonded to the second surface 102 of the first base material 1.

[0107] The wiring board 100 according to the second embodiment may have a plurality of convex bodies 6 (see FIG. 2) located not only on the first surface 101 but also on the second surface 102. The plurality of convex bodies 6 located on the second surface 102 protrude from the second surface 102 of the first substrate 1 and enter the inside of the second substrate 2. This allows the second substrate 2 located on the second surface 102 to be firmly bonded to the first substrate 1 by the anchor effect of the plurality of convex bodies 6.

[0108] <Third embodiment> In the above-described first and second embodiments, examples have been described in which the first substrate 1 has a multilayer structure in which multiple ceramic layers 10 are stacked, but the first substrate 1 does not necessarily have to have a multilayer structure.

[0109] Fig. 13 is a cross-sectional view showing an example of the configuration of a wiring board 100 according to the third embodiment. As shown in Fig. 13, the first base material 1 may have, for example, one ceramic layer 10. In this case, the first base material 1 may have only vias 31 as the first wiring 3, in other words, may not have a wiring layer 32.

[0110] Although the present disclosure has been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible without departing from the gist of the present disclosure.

[0111] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. In addition, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0112] The present technology can be configured as follows. (1) A first substrate having a first surface and a second surface opposite to the first surface, the first substrate being made of a ceramic composite material containing a glass component; a second substrate having a third surface and a fourth surface opposite to the third surface, the second substrate being mainly composed of an organic component; a first wiring located inside the first base material and extending from the first surface to the second surface; a second wiring located inside the second base material and extending from the third surface to the fourth surface; a plurality of protruding bodies protruding from the first surface and extending into the second base material; having the third surface of the second base material is bonded to the first surface of the first base material; a coefficient of thermal expansion in a direction along the first surface of the second base material is higher than that of the first base material; the first wiring and the second wiring are electrically connected at a bonding surface between the first base material and the second base material, The convex body includes a glass component and is bonded to the first base material by the glass component. Wiring board. (2) In a cross section perpendicular to the first surface, the width of the tip end of the convex body is narrower than the width of the base end of the convex body. The wiring board according to (1) above. (3) In a cross section perpendicular to the first surface, a side surface connecting the tip end and the base end of the convex body is curved in a concave shape. The wiring board according to (2) above. (4) The content of the glass component in the convex body is higher than the content of the glass component in the first base material. The wiring board according to any one of (1) to (3) above. (5) The convex body includes a base mainly composed of a glass component and a plurality of ceramic particles, The ceramic particles are more abundant on the surface of the base than in the interior of the base. The wiring board according to any one of (1) to (4) above. (6) the first substrate includes a ceramic filler; The ceramic particles of the convex body are of the same composition as the filler. The wiring board according to (5) above. (7) the first substrate has a plurality of recesses on the first surface; The second substrate is recessed into the recess. The wiring board according to any one of (1) to (6). (8) The first wiring is mainly composed of copper or silver, The second wiring is made of copper or silver as a main component. The wiring board according to any one of (1) to (7). (9) the second wiring is electrically and thermally connected to a semiconductor element mounted on the fourth surface, The first base material has a higher thermal conductivity than the second base material. The wiring board according to (8) above. (10) Of the first wiring and the second wiring, only the first wiring contains a glass component. The wiring board according to any one of (1) to (9). (11) A diffusion layer containing a metal component of the first wiring is provided between the first wiring and the first base material. The wiring board according to any one of (1) to (10) above. (12) The second base material has a plurality of organic resin layers, The second wiring has a plurality of vias penetrating one or a plurality of the organic resin layers, and a wiring layer electrically connecting the plurality of vias and positioned between adjacent ones of the organic resin layers. The wiring board according to any one of (1) to (11) above. (13) The first substrate has a plurality of ceramic layers. The wiring board according to any one of (1) to (12) above. (14) The first substrate has a higher rigidity than the second substrate. The wiring board according to any one of (1) to (13) above. (15) The first substrate contains alumina. The wiring board according to any one of (1) to (14) above. (16) A diffusion layer containing a metal component of the first wiring is provided between the first wiring and the first base material. The wiring board according to (15) above. (17) The wiring board according to any one of (1) to (16), A semiconductor element mounted on the fourth surface; having The second base has a higher thermal expansion coefficient than the semiconductor element and the first base. Semiconductor device. [Explanation of symbols]

[0113] 1 First base material 2 Second base material 3 1st wiring 4 2nd wiring 6 Convex body 7 Diffusion Layer 9. Semiconductor elements 10 Ceramic layer 20 Organic resin layer 31 Via 32 wiring layer 41 Via 42 Wiring layer 61 Base 61a Tip 61b Proximal end 61c Side 62 Ceramic particles 100 Wiring board 101 Page 1 102 Side 2 103 3rd page 104 Page 4 111 Recess 300 Semiconductor Devices

Claims

1. A first substrate having a first surface and a second surface opposite to the first surface, the first substrate being made of a ceramic composite material containing a glass component; a second substrate having a third surface and a fourth surface located opposite to the third surface, the second substrate being mainly composed of an organic component; a first wiring located inside the first base material and extending from the first surface to the second surface; a second wiring located inside the second base material and extending from the third surface to the fourth surface; A plurality of convex bodies protruding from the first surface and extending into the second base material; having the third surface of the second base material is joined to the first surface of the first base material; a coefficient of thermal expansion in a direction along the first surface of the second base material is higher than that of the first base material; the first wiring and the second wiring are electrically connected to each other at a bonding surface between the first base material and the second base material, The convex body includes a glass component and is bonded to the first base material by the glass component. Wiring board.

2. In a cross section perpendicular to the first surface, the width of the tip end of the convex body is narrower than the width of the base end of the convex body. The wiring board according to claim 1 .

3. In a cross section perpendicular to the first surface, a side surface connecting the tip end and the base end of the convex body is curved in a concave shape. The wiring board according to claim 2 .

4. The content of the glass component in the convex body is higher than the content of the glass component in the first base material. The wiring board according to any one of claims 1 to 3.

5. The convex body includes a base mainly composed of a glass component and a plurality of ceramic particles, The ceramic particles are more abundant on the surface of the base than in the interior of the base. The wiring board according to any one of claims 1 to 3.

6. the first substrate includes a ceramic filler; The ceramic particles of the convex body are of the same composition as the filler. The wiring board according to claim 5 .

7. the first substrate has a plurality of recesses on the first surface; The second substrate is embedded in the recess. The wiring board according to any one of claims 1 to 3.

8. The first wiring is mainly composed of copper or silver, The second wiring is made of copper or silver as a main component. The wiring board according to any one of claims 1 to 3.

9. the second wiring is electrically and thermally connected to a semiconductor element mounted on the fourth surface; The first base material has a higher thermal conductivity than the second base material. The wiring board according to claim 8 .

10. Of the first wiring and the second wiring, only the first wiring contains a glass component. The wiring board according to any one of claims 1 to 3.

11. A diffusion layer containing a metal component of the first wiring is provided between the first wiring and the first base material. The wiring board according to any one of claims 1 to 3.

12. The second base material has a plurality of organic resin layers, The second wiring has a plurality of vias penetrating one or a plurality of the organic resin layers, and a wiring layer electrically connecting the plurality of vias and positioned between adjacent ones of the organic resin layers. The wiring board according to any one of claims 1 to 3.

13. The first substrate has a plurality of ceramic layers. The wiring board according to any one of claims 1 to 3.

14. The first substrate has a higher rigidity than the second substrate. The wiring board according to any one of claims 1 to 3.

15. The first substrate contains alumina. The wiring board according to any one of claims 1 to 3.

16. A diffusion layer containing a metal component of the first wiring is provided between the first wiring and the first base material. The wiring board according to claim 15 .

17. A wiring board according to any one of claims 1 to 3, a semiconductor element mounted on the fourth surface; having The second base has a higher thermal expansion coefficient than the semiconductor element and the first base. Semiconductor device.

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