Circuit boards and products

Abstract

A substrate 1 according to the present invention comprises: a composite substrate 10 that includes a resin portion 30 and a plurality of ceramic portions 20 provided in the resin portion 30; and a metal layer 50 that is provided on one side of the composite substrate 10. The surface of the metal layer 50 toward the other side is in contact with the ceramic portions 20.

Description

Technical Field

[0001] The present invention relates to a substrate and a product having a metal layer.

Background Art

[0002] Conventionally, a laminate having a ceramic substrate and a metal layer made of copper foil or the like provided on the ceramic substrate via an adhesive has been provided. For example, in Japanese Unexamined Patent Application Publication No. 2017-035805, a metal-ceramic bonded substrate is provided in which a conductor layer made of copper or a copper alloy is laminated on at least one surface side of a silicon nitride substrate. In this metal-ceramic bonded substrate, a bonding layer is interposed between the silicon nitride substrate and the conductor layer, and a metal-ceramic bonded substrate in which the silicon nitride substrate and the conductor layer are bonded with the bonding layer interposed therebetween is provided.

Summary of the Invention

Problems to be Solved by the Invention

[0003] However, when an adhesive layer such as an adhesive is provided between the ceramic substrate and the metal layer, the thermal conductivity realized by the ceramic substrate is significantly impaired. In addition, since the difference in linear expansion between the ceramic substrate and the metal layer is large, cracks may occur.

[0004] The present invention provides a substrate or the like that can achieve high thermal conductivity and reduce the possibility of cracks occurring.

Means for Solving the Problems

[0005] In one aspect of the present invention, the substrate includes a composite substrate having a resin part and a plurality of ceramic parts provided in the resin part, a metal layer provided on one side or both sides of the composite substrate, and the surface on the other side or one side of the metal layer may contact the ceramic part.

[0006] According to the present invention, it is possible to provide a substrate or the like that can achieve high thermal conductivity and reduce the possibility of crack formation. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a lateral cross-sectional view of a substrate according to an embodiment of the present invention. [Figure 2] Figure 2 is a plan view of a composite substrate in an example of an embodiment of the present invention. [Figure 3] Figure 3 is a plan view of a composite substrate in another example of an embodiment of the present invention. [Figure 4] Figure 4 is a plan view of a composite substrate in yet another example of an embodiment of the present invention. [Figure 5] Figure 5 is a lateral cross-sectional view of a substrate according to a modified embodiment of the present invention. [Figure 6] Figure 6 is a lateral cross-sectional view of a substrate having an adhesive layer and a heat dissipation section. [Figure 7] Figure 7 is a lateral cross-sectional view of a substrate having a heat dissipation section in an embodiment of the present invention. [Figure 8] Figure 8 is a lateral cross-sectional view showing an embodiment of the present invention in which a filler is incorporated into the resin portion. [Figure 9] Figure 9 is a side cross-sectional view showing an embodiment of the present invention in which a fastening portion is provided. [Figure 10] Figure 10 is a lateral cross-sectional view showing an embodiment of the present invention in which the ceramic portion is not exposed on the back surface from the resin portion. [Figure 11] Figure 11 is a side cross-sectional view showing an embodiment of the present invention in which metal layers are provided on one side and the other side of a composite substrate. [Figure 12] Figure 12 is a lateral cross-sectional view showing an embodiment of Figure 11 in which an adhesive layer is provided. [Figure 13] Figure 13 is a lateral cross-sectional view showing an embodiment of the present invention in which the ceramic portion is provided on both sides of the metal layer. [Figure 14]Figure 14 is a side cross-sectional view showing an embodiment of the present invention in which a cooling body is provided on the back surface of the composite substrate. [Figure 15] Figure 15 is a lateral cross-sectional view showing an embodiment of the present invention in which a ceramic portion and a resin portion are provided on both sides of the metal layer. [Modes for carrying out the invention]

[0008] The substrate 1 in this embodiment is a laminate, and multiple layers are stacked on top of each other. As shown in Figure 1, the substrate 1 in this embodiment may have a composite substrate 10 having a resin portion 30 and a plurality of ceramic portions 20 scattered within the resin portion 30, and a metal layer 50 provided on one side surface (front surface) of the composite substrate 10. Alternatively, the metal layer 50 may be provided on the other side surface (back surface) of the metal layer 50, or, as shown in Figure 11, the composite substrate 10 may be provided on both the one side surface and the other side surface of the metal layer 50.

[0009] In Figure 1, the upper side is one side, and the lower side is the other side. The vertical direction in Figure 1 is the first direction, the horizontal direction is the second direction, and the front-to-back direction of the paper is the third direction. In this embodiment, the plane including the second and third directions is called the in-plane plane.

[0010] The other side (back surface) of the metal layer 50 may be in contact with one side of the ceramic part 20, and an adhesive layer or the like may not be provided between the other side of the metal layer 50 and one side of the ceramic part 20. In this case, the resin part 30 having adhesive function is generally bonded to the other side of the metal layer 50, thereby fixing the ceramic part 20 to the metal layer 50. However, the configuration is not limited to this, and as shown in Figure 6, an adhesive layer 40 with low thermal conductivity (e.g., 1 W / m K or higher) may be provided between the other side of the metal layer 50 and one side of the ceramic part 20. Alternatively, as shown in Figure 12, an adhesive layer 40 with low thermal conductivity (e.g., 1 W / m K or higher) may be provided on both sides of the metal layer 50, and the composite substrate 10 may be provided via the adhesive layer 40. The resin part 30 may be made of insulating material. Furthermore, the ceramic portion 20 or the metal layer 50 may be provided on one or both sides of the metal layer 50. For example, the ceramic portion 20 may be provided on one or both sides of the metal layer 50 (see Figure 13), or the resin portion 30 may be provided on one or both sides of the metal layer 50. The term "contact" in this embodiment may of course include contacts formed by plating. In addition, the composite substrate 10 may be provided on one or both sides of the metal layer 50. If the composite substrate 10 is provided on both sides of the metal layer 50, the metal layer 50 may be partially or completely embedded within the composite substrate 10 (see Figure 15).

[0011] As shown in Figures 6 and 7, a heat dissipation part 60, such as a heat sink made of copper or the like, may be provided on the other side (back side) of the composite substrate 10. Alternatively, a cooling body 65, such as a heat sink, may be provided on the other side (back side) of the substrate 1 (see Figure 14).

[0012] The metal layer 50 may be made of, for example, copper, or it may be made of copper foil or copper plate. Circuits may be formed on the metal layer 50 in a later process, or a metal layer 50 with circuits already formed on it may be provided to constitute a circuit layer.

[0013] When the mode in which the metal layer 50 and the ceramic part 20 are in contact is used, heat transmitted from an electronic component or the like placed on the metal layer 50 is efficiently transmitted from the metal layer 50 to the ceramic part 20, so the thermal conductivity is not impaired.

[0014] As shown in FIG. 1, the ceramic part 20 may be exposed from the resin part 30 on the other side (back surface). In this case, since the heat transmitted from the metal layer 50 to the ceramic part 20 is released from the other side, a high heat dissipation effect can be realized. However, as shown in FIG. 10, the ceramic part 20 does not have to be exposed from the resin part 30 on the other side (back surface).

[0015] Also, as shown in FIG. 5, the ceramic parts 20 may be connected on the other side and spread in the plane. In this case, the ceramic parts 20 can be provided widely in the plane, and a higher heat dissipation effect can be realized.

[0016] As shown in FIGS. 2 and 3, the ceramic part 20 may be provided in an island shape in the in-plane direction within the resin part 30. In this case, the resin part 30 can thermally expand the whole in the in-plane direction. Generally, since the linear expansion coefficients between the metal layer 50 made of copper or the like and the resin part 30 are close values, it is possible to prevent the occurrence of cracks due to the difference in linear expansion coefficients as in the prior art.

[0017] <000-0099>The ceramic part 20 may have a polygonal prism shape or a cylindrical shape. In this case, when viewed in the in-plane direction, the ceramic part 20 has a polygonal shape or a circular shape (see FIGS. 2 and 3). The polygonal shape in the present embodiment includes a substantial polygonal shape in which the corners are rounded (see FIG. 2).

[0018] The ceramic used in the ceramic part 20 may be, for example, alumina, aluminum nitride, boron nitride, silicon nitride, silicon carbide, beryllia, etc. These ceramics may be used individually or in combination of two or more types. The approximate value (estimated value) of the thermal conductivity of the composite substrate 10 can be calculated as: thermal conductivity of ceramic part 20 × area of ​​the cross-section (in-plane direction) of ceramic part 20 / total area + resin part 30 × area of ​​the cross-section (in-plane direction) of resin part 30 / total area. For example, if alumina is used as the ceramic part 20, the thermal conductivity will be about 10 to 30 w / m·k, and if aluminum nitride is used as the ceramic part 20, the thermal conductivity will be about 80 to 150 w / m·k.

[0019] The resin part 30 may be a thermoplastic resin or a thermosetting resin. For example, epoxy resin may be used as the resin material. However, it is not limited to this, and unsaturated polyester resin, vinyl ester resin, bismaleimide resin, benzoxazine resin, triazine resin, phenol resin, urea resin, melamine resin, polyimide resin, polyolefin resin, aliphatic polyamide resin, semi-aromatic polyamide resin, aromatic polyester resin, polycarbonate resin, polystyrene resin, etc. may be used as the resin material.

[0020] As shown in Figure 8, a filler 35 sealed by the resin portion 30 may be provided. This filler 35 may be in the form of particles or fibers. Conductive fillers can be used as the filler 35, and metal materials or carbon materials may also be used. As metal materials, metal particles, metal fibers, organometallic particles, organometallic complex particles, metal nanoparticles, metal nanofibers, organometallic nanoparticles, etc. may be used. As carbon materials, for example, graphite particles, carbon particles, carbon milled fibers, carbon black, carbon nanotubes, vapor-deposited carbon fibers (VGCF), etc. may be used.

[0021] Figure 4 is a plan view including the second and third directions, but the ceramic parts 20 may be arranged in a stripe pattern in the plan view. In Figure 4, the ceramic parts 20 may be in the shape of plates, and the plate-shaped ceramic parts 20 may be bonded together by the resin parts 30. In this case, the plate-shaped ceramic parts 20 will be positioned between the resin parts 30. Multiple composite substrates 10 may be stacked to form a multilayer board. In this case, multiple combinations of composite substrates 10 and metal layers 50 may be stacked in the thickness direction to form a multilayer board.

[0022] As shown in Figure 9, fastening parts 90 such as screws may be provided to fasten the resin part 30 and the metal layer 50. Each of the resin part 30 and the metal layer 50 may be fastened with the fastening parts 90, or some of the multiple resin parts 30 may be fastened with the fastening parts 90 to the metal layer 50. By using such an embodiment, the resin part 30 and the metal layer 50 can be fixed more securely.

[0023] Furthermore, an adhesive with high thermal conductivity may be provided between the metal foil and the ceramic or resin, or both. Alternatively, a metal layer made of metal foil or the like may be placed directly or with an adhesive layer in between on the composite substrate 10 made of resin and ceramic in an electroless plating bath. Alternatively, the first layer may be an electroless plated metal layer, and the second layer may be an electroplated metal layer made of metal foil or the like, and the first and second layers may be reversed in order.

[0024] The substrate 1 in the above-described embodiment may be provided with electronic components such as semiconductor elements, capacitors, and resistors. These electronic components may be sealed in a sealing portion, and electronic devices (including packages) such as IC packages and electronic devices may be provided. Such electronic devices may be incorporated into any mounting device such as automobiles, airplanes, ships, helicopters, personal computers, and home appliances. In addition, an insulated printed circuit board, a house, etc., using the substrate 1 as in this embodiment may be provided. The products of this embodiment may include anything from electronic components, devices, electrical products, communication equipment, cars, etc.

[0025] The descriptions of the embodiments, modifications, and disclosures of the drawings described above are merely examples for illustrating the invention described in the claims, and the invention described in the claims is not limited by the descriptions of the embodiments or the disclosures of the drawings described above. [Explanation of Symbols]

[0026] 1 circuit board 10 Composite substrate 20 Ceramic part 30 Resin part 50 metal layer 90 Fastening part

Claims

1. A composite substrate having a resin portion and a plurality of ceramic portions provided within the resin portion, A metal layer provided on one side of the composite substrate, Equipped with, The other side of the metal layer is in contact with the ceramic portion. A substrate having fastening portions for fastening the resin portion and the metal layer.

2. The substrate according to claim 1, wherein the ceramic portion is exposed from the resin portion on the other side.

3. The substrate according to claim 2, wherein the ceramic portion is connected on the other side.

4. The substrate according to claim 1 or 2, wherein the ceramic portion is provided in an island-like manner in the in-plane direction within the resin portion.

5. The substrate according to claim 1 or 2, wherein the ceramic portion is polygonal prism-shaped or cylindrical.

6. The substrate according to claim 1 or 2, wherein a resin portion or a ceramic portion is provided on the side of the metal layer.

7. A composite substrate having a resin portion and a plurality of ceramic portions provided within the resin portion, A metal layer provided on one side of the composite substrate, An adhesive layer provided between the metal layer and the composite substrate, Equipped with, A substrate having fastening portions for fastening the resin portion and the metal layer.

8. A product comprising the substrate described in claim 1 or 7.

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