Heat dissipation member

Abstract

This heat dissipation member has a ceramic substrate, a heat dissipating body, and a metallized member. The ceramic substrate has a first surface and a second surface positioned facing the first surface. The heat dissipating body is made of metal and is in contact with the first surface. The metallized member is positioned on the first surface. The heat dissipating body has a third surface in contact with the first surface, a fourth surface positioned facing the third surface, and a fifth surface connected to the third surface and the fourth surface. The metallized member is connected to at least a part of the fifth surface.

Description

Heat dissipation material

[0001] The disclosed embodiments relate to a heat dissipation member.

[0002] 2. Description of the Related Art Conventionally, heat dissipation members such as circuit boards in which a metal plate is bonded onto a ceramic substrate are known.

[0003] Japanese Patent Application Laid-Open No. 2001-332854

[0004] A heat dissipation member according to one aspect of the embodiment includes a ceramic substrate, a heat sink, and a metallization member. The ceramic substrate has a first surface and a second surface opposite the first surface. The heat sink is made of metal and is in contact with the first surface. The metallization member is located on the first surface. The heat sink has a third surface in contact with the first surface, a fourth surface opposite the third surface, and a fifth surface connected to the third and fourth surfaces. The metallization member is connected to at least a portion of the fifth surface.

[0005] FIG. 1 is a side view showing an example of the configuration of a heat dissipation member according to an embodiment. FIG. 2 is a plan view showing an example of the configuration of a heat dissipation member according to an embodiment. FIG. 3 is a side view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 1. FIG. 4 is a plan view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 1. FIG. 5 is a side view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 2. FIG. 6 is a plan view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 2. FIG. 7 is a side view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 3. FIG. 8 is a plan view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 3. FIG. 9 is a side view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 4. FIG. 10 is a plan view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 4. FIG. 11 is a side view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 5. FIG. 12 is a plan view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 5. FIG. 13 is a side view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 6. FIG. 14 is a plan view showing an example of the configuration of a heat dissipation member according to Alternative Embodiment 6. Fig. 15 is a side view showing an example of the configuration of a heat dissipation member according to another embodiment 7. Fig. 16 is a side view showing an example of the configuration of a heat dissipation member according to another embodiment 8.

[0006] Hereinafter, embodiments of the heat dissipation member disclosed in the present application will be described with reference to the accompanying drawings. Note that the present disclosure is not limited to the embodiments described below. Furthermore, each embodiment can be appropriately combined within a range that does not cause contradictions in the processing content. Furthermore, the same components in each of the following embodiments will be assigned the same reference numerals, and duplicated explanations will be omitted.

[0007] Conventionally, heat dissipation components such as circuit boards in which a metal plate is bonded onto a ceramic substrate have been known. In some cases, a metallized member is disposed on the ceramic substrate in order to increase the heat dissipation area of ​​the ceramic substrate, and the metal plate and the ceramic substrate are bonded via the metallized member.

[0008] However, in a structure in which a metallized member is interposed between a metal plate and a ceramic substrate, the transfer of heat from the ceramic substrate to the metal plate is hindered by the metallized member, which could reduce the heat dissipation performance of the heat dissipation member.

[0009] Therefore, there is a need for a technology that can improve the heat dissipation performance of heat dissipation members.

[0010] <Configuration of Heat Dissipation Member> First, the configuration of the heat dissipation member 1 according to the embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a side view showing an example of the configuration of the heat dissipation member 1 according to the embodiment. Fig. 2 is a plan view showing an example of the configuration of the heat dissipation member 1 according to the embodiment.

[0011] As shown in FIGS. 1 and 2, a heat dissipation member 1 according to the embodiment includes a ceramic substrate 2, a heat dissipation body 3, and a metallized member 4.

[0012] The ceramic substrate 2 has a flat plate shape. The ceramic substrate 2 has a first surface 2a and a second surface 2b located opposite the first surface 2a. The first surface 2a is used as a mounting surface for, for example, the heat sink 3, the metallized member 4, and electronic components (not shown) that are heat-generating bodies. The second surface 2b is used as a heat dissipation surface that dissipates heat generated by the electronic components.

[0013] The ceramic substrate 2 is made of ceramics. Examples of the ceramics that make up the ceramic substrate 2 include aluminum nitride (AlN) and aluminum oxide (Al ２ O ３ , alumina), silicon carbide (SiC), silicon nitride (Si ３ N ４ ) or the like as a main component can be used.

[0014] The heat sink 3 is a metal member having a higher thermal conductivity than the ceramic substrate 2, and may have, for example, a substantially rectangular parallelepiped shape. The heat sink 3 dissipates heat generated from electronic components (not shown) provided on the heat sink 3. The metal constituting the heat sink 3 may be, for example, copper or a copper alloy. The heat sink 3 may also be a metal plate.

[0015] The heat sink 3 may be bonded to the ceramic substrate 2 by a bonding material 5. In other words, the heat sink 3 may be in contact with the first surface 2a of the ceramic substrate 2 via the bonding material 5. As the bonding material 5, for example, a brazing filler metal containing at least one active metal selected from Ti, Zr, Nb, and Hf is used. The brazing filler metal may be, for example, a silver-copper based brazing filler metal or a copper based brazing filler metal. A silver-copper based brazing filler metal is a brazing filler metal containing a total of 95% by mass or more of silver and copper. A copper based brazing filler metal is a brazing filler metal containing 50% by mass or more of copper. Alternatively, the heat sink 3 may be in direct contact with the first surface 2a of the ceramic substrate 2.

[0016] The heat sink 3 has a third surface 3a in contact with the first surface 2a of the ceramic substrate 2, a fourth surface 3b opposite the third surface 3a, and a fifth surface 3c connected to the third surface 3a and the fourth surface 3b. The heat sink 3 has a quadrangular shape in a plan view seen from a direction perpendicular to the third surface 3a or the fourth surface 3b. The fifth surface 3c is one of the four side surfaces of the heat sink 3.

[0017] The metallized member 4 is a sintered body made of metal with a higher thermal conductivity than the ceramic substrate 2. A sintered body made of metal is formed by applying heat to a molded body containing a plurality of metal particles. The metallized member 4 may form wiring connected to an electronic component (not shown) provided on the heat sink 3. The metallized member 4 may also be connected to other wiring connected to a power supply, a motor, other electronic components, etc. The metallized member 4 may be made of, for example, copper or a copper alloy.

[0018] The metallized member 4 may be bonded to the ceramic substrate 2 by the bonding material 5. In other words, the metallized member 4 may be located on the first surface 2a of the ceramic substrate 2 via the bonding material 5. The metallized member 4 may be formed, for example, by printing a metal paste and then heating it.

[0019] Here, in the embodiment, the metallized member 4 is connected to at least a portion of the fifth surface 3c of the heat sink 3. That is, the connection between the metallized member 4 and the heat sink 3 is realized on the fifth surface 3c, which is a side surface of the heat sink, and the metallized member 4 is not interposed between the heat sink 3 and the ceramic substrate 2. With this configuration, the impediment to the transfer of heat from the ceramic substrate 2 to the heat sink 3 can be reduced compared to when a metallized member is interposed between the heat sink 3 and the ceramic substrate 2. Therefore, according to the embodiment, the transfer of heat from the ceramic substrate 2 to the heat sink 3 can be smoothed, thereby improving the heat dissipation performance of the heat sink 1.

[0020] Furthermore, since there is no metallized member 4 between the heat sink 3 and the ceramic substrate 2, the heat sink 1 can be made thinner than when there is a metallized member between the heat sink 3 and the ceramic substrate 2.

[0021] In addition, in the embodiment, the metallized member 4 may extend linearly from the heat sink 3. This allows the surface area of ​​the heat sink 3 to be substantially increased by an amount corresponding to the surface area of ​​the metallized member 4, thereby further improving the heat dissipation performance of the heat sink 1.

[0022] In addition, in the embodiment, the thickness of the metallized member 4 may be thinner than the thickness of the heat sink 3. This improves the workability of the metallized member 4 compared to when the thickness of the metallized member 4 is thicker than the thickness of the heat sink 3, and therefore makes it possible to easily form a fine wiring pattern on the metallized member 4.

[0023] In the embodiment, the heat sink 3 may be in contact with the first surface 2 a of the ceramic substrate 2 via a bonding material 5 containing at least one active metal selected from Ti, Zr, Nb, and Hf. This promotes diffusion of the active metal from the bonding material 5 to the heat sink 3, thereby firmly fixing the heat sink 3 and the ceramic substrate 2 together and improving the reliability of the connection between the heat sink 3 and the ceramic substrate 2.

[0024] In addition, in the embodiment, the metallized member 4 may be in contact with the first surface 2 a of the ceramic substrate 2 via a bonding material 5 containing at least one active metal selected from Ti, Zr, Nb, and Hf. This can promote diffusion of the active metal from the bonding material 5 to the metallized member 4, thereby firmly fixing the metallized member 4 and the ceramic substrate 2 together and improving the connection reliability between the metallized member 4 and the ceramic substrate 2.

[0025] In the embodiment, the metallized member 4 may be made of a plurality of metal particles, with voids between the metal particles. With this configuration, the elastic modulus of the metallized member 4 can be made smaller than that of the heat sink 3, thereby reducing the occurrence of warping of the heat sink 3. Furthermore, if the metallized member 4 has open pores that are connected to voids, the heat dissipation area of ​​the metallized member 4 can be increased, thereby improving heat dissipation performance.

[0026] <Another embodiment 1> Next, various types of embodiments of the heat dissipation member 1 according to the embodiment will be described. Fig. 3 is a side view showing an example of the configuration of the heat dissipation member 1 according to another embodiment 1. Fig. 4 is a plan view showing an example of the configuration of the heat dissipation member 1 according to another embodiment 1. In the various other embodiments below, the same components as those in the embodiment are designated by the same reference numerals, and redundant description will be omitted.

[0027] 3 and 4 , in the heat dissipation member 1 according to another embodiment 1, the fifth surface 3 c of the heat sink 3 may have an inclined portion 3 cc. In another embodiment 1, the metallized member 4 may be connected to the inclined portion 3 cc. This increases the contact area between the metallized member 4 and the heat sink 3, thereby improving the connection reliability between the metallized member 4 and the heat sink 3.

[0028] In another embodiment 1, the inclined portion 3 cc may be curved, which can increase the contact area between the metallized member 4 and the heat sink 3, thereby further improving the connection reliability between the metallized member 4 and the heat sink 3.

[0029] 3 , in another embodiment 1, the inclined portion 3cc may be connected to the third surface 3a of the heat sink 3. The angle α formed between the inclined portion 3cc and the first surface 2a of the ceramic substrate 2 at the position where the inclined portion 3cc and the third surface 3a are connected may be an obtuse angle. This increases the contact area between the ceramic substrate 2 and the heat sink 3, thereby improving the connection reliability between the ceramic substrate 2 and the heat sink 3.

[0030] <Another embodiment 2> Fig. 5 is a side view showing an example of the configuration of a heat dissipation member 1 according to another embodiment 2. Fig. 6 is a plan view showing an example of the configuration of a heat dissipation member 1 according to another embodiment 2. As shown in Figs. 5 and 6, in the heat dissipation member 1 according to another embodiment 2, the structure of the inclined portion 3cc of the heat dissipation body 3 differs from that of the above-described another embodiment 1.

[0031] 5 , in another embodiment 2, the angle α formed between the inclined portion 3cc and the first surface 2a of the ceramic substrate 2 at the position where the inclined portion 3cc and the third surface 3a are connected may be an acute angle. This allows a part of the metallized member 4 to be sandwiched between the inclined portion 3cc and the ceramic substrate 2, thereby improving the connection reliability between the ceramic substrate 2 and the metallized member 4.

[0032] <Another embodiment 3> Fig. 7 is a side view showing an example of the configuration of a heat dissipation member 1 according to another embodiment 3. Fig. 8 is a plan view showing an example of the configuration of a heat dissipation member 1 according to another embodiment 3. As shown in Figs. 7 and 8, in the heat dissipation member 1 according to another embodiment 3, the structure of the fifth surface 3c of the heat sink 3 differs from that of the above-described another embodiment 1.

[0033] Specifically, in another embodiment 3, the fifth surface 3c may have an inclined portion 3c1 connected to the fourth surface 3b of the heat sink 3, and a non-inclined portion 3c2 connected to both the inclined portion 3c1 and the third surface 3a of the heat sink 3. The non-inclined portion 3c2 is a surface that is inclined less than the inclined portion 3c1 with respect to a direction perpendicular to the first surface 2a of the ceramic substrate 2. In another embodiment 3, the metallized member 4 may be connected to the non-inclined portion 3c2. With this configuration, the connection between the metallized member 4 and the heat sink 3 can be easily achieved by, for example, printing, compared to when the metallized member 4 is connected to the inclined portion 3cc (see FIG. 3 ), thereby improving the efficiency of the manufacturing process of the heat sink 1.

[0034] <Alternative Embodiment 4> Fig. 9 is a side view showing an example of the configuration of a heat dissipation member 1 according to Alternative Embodiment 4. Fig. 10 is a plan view showing an example of the configuration of a heat dissipation member 1 according to Alternative Embodiment 4. As shown in Figs. 9 and 10, the heat dissipation member 1 according to Alternative Embodiment 4 differs from the above-described Alternative Embodiment 3 in the arrangement of the metallized members 4.

[0035] Specifically, in another embodiment 4, the metallized member 4 may be positioned so as to cover a part of the inclined portion 3c1 including the position P where the inclined portion 3c1 and the non-inclined portion 3c2 of the heat sink 3 are connected. This allows the thermal stress acting on the heat sink 3 from the ceramic substrate 2 to be dispersed to the metallized member 4 side at the position P where the inclined portion 3c1 and the non-inclined portion 3c2 are connected, even if a difference in thermal expansion occurs between the heat sink 3 and the ceramic substrate 2 due to a temperature difference.

[0036] <Another embodiment 5> Fig. 11 is a side view showing an example of the configuration of a heat dissipation member 1 according to another embodiment 5. Fig. 12 is a plan view showing an example of the configuration of a heat dissipation member 1 according to another embodiment 5.

[0037] 11 and 12 , a heat dissipation member 1 according to another embodiment 5 differs from the above-described embodiments in that a plurality of protrusions 3d are provided on the fifth surface 3c of the heat dissipation body 3. The plurality of protrusions 3d may be arranged in a lattice pattern with gaps between them in a plan view seen from a direction perpendicular to the fifth surface 3c. The plurality of protrusions 3d dissipate heat conducted from the fifth surface 3c to the external atmosphere.

[0038] In this way, by providing multiple protrusions 3d on the fifth surface 3c of the heat sink 3, heat dissipation from the heat sink 3 to the external atmosphere can be promoted, thereby improving the heat dissipation properties of the heat sink member 1.

[0039] 13 is a side view showing an example of the configuration of a heat dissipation member 1 according to another embodiment 6. FIG. 14 is a plan view showing an example of the configuration of a heat dissipation member 1 according to another embodiment 6.

[0040] 13 and 14 , the heat dissipation member 1 according to another embodiment 6 differs from the above-described embodiments in that a lead terminal 3 e is provided on the fifth surface 3 c of the heat dissipation body 3. The lead terminal 3 e may be located on the fifth surface 3 c above the position where the metallized member 4 is connected.

[0041] In this way, by providing the lead terminal 3e on the fifth surface 3c of the heat sink 3, the metallized member 4 and the lead terminal 3e can be stacked vertically and arranged three-dimensionally, thereby making it possible to reduce the size of the heat sink 1 in the planar direction.

[0042] Seventh Alternative Embodiment FIG. 15 is a side view showing an example of the configuration of a heat dissipation member 1 according to a seventh alternative embodiment.

[0043] 15 , a heat dissipation member 1 according to another embodiment 7 differs from the above-described embodiments in that a reinforcing member 6 is provided. The reinforcing member 6 may have a flat plate shape. Examples of the metal that can be used to form the reinforcing member 6 include copper and copper alloys.

[0044] The reinforcing member 6 may be bonded to the ceramic substrate 2 by a bonding material 7. The reinforcing member 6 is located on the second surface 2b of the ceramic substrate 2 via the bonding material 7. The reinforcing member 6 can be formed by, for example, attaching a metal foil or printing a metal.

[0045] In this way, by positioning the reinforcing member 6 on the second surface 2 b of the ceramic substrate 2, it is possible to reduce warpage of the ceramic substrate 2 caused by the stress difference between the first surface 2 a and the second surface 2 b. Therefore, according to another embodiment 7, it is possible to improve the reliability of the heat dissipation member 1.

[0046] Eighth Alternative Embodiment FIG. 16 is a side view showing an example of the configuration of a heat dissipation member 1 according to an eighth alternative embodiment.

[0047] 16 , a heat dissipation member 1 according to another embodiment 8 differs from the above-described embodiments in that a heat sink 8 is provided. The heat sink 8 is made of, for example, a metal material having a higher thermal conductivity than the ceramic substrate 2. The metal that can be used to make the heat sink 8 is, for example, copper or a copper alloy.

[0048] The heat sink 8 may be bonded to the ceramic substrate 2 by a bonding material 9. The heat sink 8 is located on the second surface 2b of the ceramic substrate 2 via the bonding material 9.

[0049] In this way, the heat sink 8 is positioned on the second surface 2 b of the ceramic substrate 2, which promotes heat dissipation from the second surface 2 b, which is the heat dissipation surface, to the external atmosphere. Therefore, according to another embodiment 8, the heat dissipation performance of the heat dissipation member 1 can be further improved.

[0050] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

[0051] Further advantages and alternative embodiments may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0052] REFERENCE SIGNS LIST 1 heat dissipation member 2 ceramic substrate 3 heat dissipation body 3c1 inclined portion 3c2 non-inclined portion 3cc inclined portion 3d protrusion 3e lead terminal 4 metallized member 5, 7, 9 bonding material 6 reinforcing member 8 heat sink

Claims

1. A heat dissipation member comprising: a ceramic substrate having a first surface and a second surface opposite the first surface; a metallic heat sink in contact with the first surface; and a metallized member located on the first surface, wherein the heat sink has a third surface in contact with the first surface, a fourth surface opposite the third surface, and a fifth surface connected to the third surface and the fourth surface, and the metallized member is connected to at least a portion of the fifth surface.

2. The heat dissipation member according to claim 1, wherein the fifth surface has an inclined portion, and the metallization member is connected to the inclined portion.

3. A heat dissipation member as described in claim 2, wherein the inclined portion is connected to the third surface, and the angle formed between the inclined portion and the first surface at the position where the inclined portion and the third surface are connected is an obtuse angle or an acute angle.

4. The heat dissipation member according to claim 1, wherein the thickness of said metallization member is thinner than the thickness of said heat dissipation body.

5. The heat dissipation member according to claim 1, wherein the metallization member extends linearly from the heat dissipation body.

6. The heat dissipation member according to claim 1, wherein said heat sink has a plurality of protrusions on said fifth surface.

7. The heat dissipation member according to claim 1, wherein the heat sink is in contact with the first surface via a bonding material containing at least one active metal selected from the group consisting of Ti, Zr, Nb and Hf.

8. The heat dissipation member according to claim 1, wherein the metallized member is in contact with the first surface via a bonding material containing at least one active metal selected from the group consisting of Ti, Zr, Nb and Hf.

9. The heat dissipation member according to claim 1, wherein the metallized member is made of a plurality of metal particles and has voids between the metal particles.

10. The heat dissipation member of claim 1, further comprising a reinforcing member located on said second surface.

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