Heat exchange substrate and semiconductor device

Abstract

A heat exchange substrate (1) is formed by integrally molding a substrate portion (2) in which an electronic component is mounted on a first surface (21), and a plurality of fins (3) protruding from a second surface (22) on the side of the substrate portion (2) opposite from the first surface (21). The plurality of fins (3) are arranged in two directions that extend along the second surface (22) and intersect each other. Each fin (3) has, on a portion of the outer surface thereof, an undercut surface (31) having, as a normal vector, a vector including a vector component that faces the substrate-portion (2) side.

Description

Heat exchange substrate and semiconductor device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-086930, filed on May 29, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a heat exchange substrate and a semiconductor device.

[0003] For example, a heat exchange substrate for cooling electronic components such as semiconductors is described in Patent Document 1. The heat exchange substrate described in this document is formed by integrally molding a substrate portion on which the electronic components are mounted and fin portions protruding from the substrate portion.

[0004] JP 2011-222624 A

[0005] The heat exchange substrate disclosed in Patent Document 1 has room for improvement in the shape of the fin portion from the viewpoint of cooling efficiency.

[0006] The present disclosure provides a heat exchange substrate and a semiconductor device that can easily improve cooling efficiency.

[0007] One aspect of the present disclosure is a heat exchange substrate in which a substrate portion on which electronic components are mounted on a first surface and a plurality of fin portions protruding from a second surface of the substrate portion opposite the first surface are integrally molded, wherein the plurality of fin portions are arranged along the second surface and in two directions that intersect with each other, and the fin portions have an undercut surface on a part of their outer surface that has a vector as a normal vector that includes a vector component pointing toward the substrate portion.

[0008] Another aspect of the present disclosure is a semiconductor device including the heat exchange substrate described above and a semiconductor element mounted on the first surface of the heat exchange substrate.

[0009] In the heat exchanger substrate, the fins are arranged along the second surface and in two intersecting directions. This increases the contact area of ​​the heat exchanger substrate with the refrigerant. The fins also have undercuts on parts of their outer surfaces. This allows the refrigerant to flow between the undercuts of the fins and the second surface of the substrate. This improves the cooling efficiency of electronic components mounted on the heat exchanger substrate.

[0010] As described above, according to the above aspect, it is possible to provide a heat exchange substrate and a semiconductor device that can easily improve cooling efficiency.

[0011] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a perspective view of a heat exchange substrate according to a first embodiment, Fig. 2 is a cross-sectional view of a fin portion according to the first embodiment, Fig. 3 is a cross-sectional view of a semiconductor device according to the first embodiment, Fig. 4 is a cross-sectional view of a fin portion according to a second embodiment, Fig. 5 is a cross-sectional view of a fin portion according to a modified embodiment of the second embodiment, Fig. 6 is a cross-sectional view of a fin portion according to a third embodiment, Fig. 7 is a perspective view of a fin portion according to the third embodiment, Fig. 8 is a cross-sectional view of a fin portion according to a fourth embodiment, Fig. 9 is a cross-sectional view of a fin portion according to a modified embodiment of the fourth embodiment, Fig. 10 is a cross-sectional view of a fin portion according to a fifth embodiment, Fig. 11 is a perspective view of a fin portion according to the fifth embodiment, Fig. 12 is a cross-sectional view of a fin portion according to a modified embodiment of the fifth embodiment, and Fig. 13 is a cross-sectional view of a fin portion according to a fifth embodiment. FIG. 16 is a cross-sectional explanatory diagram of the fin portion in a modified form of embodiment 5, FIG. 14 is a cross-sectional explanatory diagram of the fin portion in embodiment 6, FIG. 15 is a side view of the fin portion in embodiment 7, FIG. 16 is a cross-sectional explanatory diagram taken along line XVI-XVI of FIG. 15, FIG. 17 is a cross-sectional explanatory diagram of the fin portion in embodiment 8, FIG. 18 is a cross-sectional explanatory diagram of the fin portion in a modified form of embodiment 8, FIG. 19 is a cross-sectional explanatory diagram of the heat exchanger substrate in embodiment 9, FIG. 20 is a plan view of the heat exchanger substrate in embodiment 9 as seen from the protruding side of the fin portion, FIG. 21 is a cross-sectional explanatory diagram of the heat exchanger substrate in reference form 1, FIG. 22 is a cross-sectional explanatory diagram taken along line XXI-XXI of FIG. 21, FIG. 23 is a cross-sectional explanatory diagram of the heat exchanger substrate in reference form 2, and FIG. 24 is a cross-sectional explanatory diagram taken along line XXIII-XXIII of FIG. 23.

[0012] (Embodiment 1) An embodiment of a heat exchanger substrate and a semiconductor device will be described with reference to Figures 1 to 3. The heat exchanger substrate 1 of this embodiment is a heat exchanger substrate in which a substrate portion 2 and a plurality of fin portions 3 are integrally molded. The substrate portion 2 has an electronic component 5 mounted on a first surface 21. The plurality of fin portions 3 protrude from a second surface 22 of the substrate portion 2, which is opposite the first surface 21.

[0013] The multiple fin portions 3 are arranged along the second surface 22 and in two directions that intersect with each other. In this embodiment, multiple fin portions 3 are arranged in both the X direction and the Y direction shown in FIG. 1 . The X direction and the Y direction are parallel to the substrate portion 2, and the X direction and the Y direction are perpendicular to each other. The normal direction of the substrate portion 2 is appropriately referred to as the Z direction, and the Z direction is perpendicular to the X direction and the Y direction. The direction along the refrigerant flow direction F, which will be described later, is defined as the Y direction.

[0014] 2, the fin portion 3 has an undercut surface 31 on a part of its outer surface. The undercut surface 31 has a normal vector NU that includes a vector component NUz pointing toward the substrate portion 2.

[0015] The cross-sectional area of ​​the fin portion 3 taken along a plane parallel to the substrate portion 2 varies depending on the distance from the substrate portion 2. At least a portion of the large cross-sectional area portion 322, which has a larger cross-sectional area than the minimum cross-sectional area portion 321 having the smallest cross-sectional area, is provided closer to the tip than the minimum cross-sectional area portion 321. In this embodiment, when referring to the cross-sectional area of ​​the fin portion 3, this refers to the cross-sectional area of ​​the cross-section taken along a plane parallel to the substrate portion 2, unless otherwise specified.

[0016] In this embodiment, the fin portion 3 has a cylindrical portion and a trapezoidal rotor portion formed at the tip side of the cylindrical portion. The cylindrical portion is the minimum cross-sectional area portion 321. The trapezoidal rotor portion has a tapered shape such that the outer diameter gradually increases from the tip of the minimum cross-sectional area portion 321 toward the tip side. The tapered surface that is the outer peripheral surface of the trapezoidal rotor portion is the undercut surface 31.

[0017] The undercut surface 31 is formed continuously over the entire width of the fin portion 3 in one direction parallel to the substrate portion 2. In this embodiment, the undercut surface 31 is formed continuously over the entire periphery of the fin portion 3. Accordingly, the undercut surface 31 is formed continuously over the entire width of the fin portion 3 in both the X direction and the Y direction.

[0018] Furthermore, the volume of the tip side region 302 of the fin portion 3, which extends from half the protrusion height h to the tip, is larger than the volume of the base side region 301, which extends from the second surface 22 of the substrate portion 2 to half the protrusion height h.

[0019] The fin portion 3 has a maximum cross-sectional area portion 323, where the cross-sectional area is maximum, provided in the tip side region 302. In this embodiment, the maximum cross-sectional area portion 323 is the tip portion of the fin portion 3.

[0020] In this embodiment, the heat exchanger substrate 1 is made of a ceramic material, particularly at least one of aluminum nitride, silicon nitride, aluminum oxide, silicon oxide, zirconia, and boron nitride.

[0021] The heat exchanger substrate 1 of this embodiment can be manufactured using, for example, a 3D printer. By using a 3D printer, the heat exchanger substrate 1 in which the plurality of fin portions 3 having undercut surfaces 31 and the substrate portion 2 are integrated can be easily manufactured.

[0022] Conductor wiring (not shown) is formed on the first surface 21 of the substrate portion 2. As shown in Fig. 3, the electronic components 5 mounted on the first surface 21 are electrically connected to part of the conductor wiring. At least one of the electronic components 5 mounted on the heat exchanger substrate 1 of this embodiment may be a semiconductor element 51. This forms a semiconductor device 10 including the heat exchanger substrate 1 and the semiconductor element 51 mounted on the first surface 21 of the heat exchanger substrate 1.

[0023] In the semiconductor device 10, the second surface 22 of the substrate 2 faces the coolant flow path 11. That is, the multiple fins 3 protrude toward the coolant flow path 11. The tips of the fins 3 are close to a wall surface 41 of the coolant flow path 11 on the opposite side from the substrate 2. The gap between the tips of the fins 3 and the wall surface 41 can be, for example, 0.2 mm or less. The tips of the fins 3 can also abut against the wall surface of the coolant flow path 11 on the opposite side from the substrate 2.

[0024] The refrigerant flow path 11 can be used to pass liquid refrigerants such as natural refrigerants such as water or ammonia, water mixed with ethylene glycol-based antifreeze, fluorocarbon-based refrigerants such as Fluorinert, fluorocarbon-based refrigerants such as HCFC123 or HFC134a, alcohol-based refrigerants such as methanol or alcohol, and ketone-based refrigerants such as acetone.

[0025] 3 shows an example in which two semiconductor elements 51 are mounted on the first surface 21 of the substrate portion 2, but electronic components 5 other than the semiconductor elements 51 can also be mounted on the first surface 21. The arrow F shown in the figure indicates the flow of the coolant. The same applies to the arrows F in the other figures. Note that this coolant flow direction F refers to the overall flow direction of the coolant.

[0026] Next, the effects of this embodiment will be described. In the heat exchanger substrate 1, the fins 3 are arranged along the second surface 22 and in two directions that intersect each other. This makes it easy to increase the contact area of ​​the heat exchanger substrate 1 with the refrigerant. In addition, the fins 3 have undercut surfaces 31 on part of their outer surfaces. This allows the refrigerant to flow between the undercut surfaces 31 of the fins 3 and the second surface 22 of the substrate 2. This makes it easy to improve the cooling efficiency of the electronic components 5 mounted on the heat exchanger substrate 1.

[0027] Furthermore, at least a portion of the large cross-sectional area portion 322 of the fin portion 3 is located closer to the tip than the minimum cross-sectional area portion 321. Therefore, the coolant flow path 11 formed between the multiple fin portions 3 is likely to be narrower near the tip of the fin portion 3 than near the base of the fin portion 3. As a result, the pressure loss at positions farther from the second surface 22 is likely to be greater than at positions closer to the second surface 22. This makes it easier to increase the flow rate and flow velocity of the coolant near the second surface 22. As a result, the cooling efficiency of the electronic components 5 is likely to be improved.

[0028] Furthermore, the volume of the tip side region 302 of the fin portion 3 is larger than the volume of the base side region 301. With this configuration, as described above, the pressure loss at positions farther from the second surface 22 tends to be larger than that at positions closer to the second surface 22. This makes it easier to increase the flow rate and flow velocity of the refrigerant at positions closer to the second surface 22.

[0029] Furthermore, the fin portion 3 has the maximum cross-sectional area portion 323 provided in the tip side region 302. This configuration also makes it easier to increase the flow rate and flow velocity of the coolant in the vicinity of the second surface 22.

[0030] Moreover, the undercut surface 31 is formed continuously over the entire width in the Y direction of the fin portion 3. Therefore, the pressure loss of the refrigerant can be reduced and the refrigerant can be efficiently brought into contact with the outer peripheral surface of the fin portion 3.

[0031] The heat exchange substrate 1 is made of a ceramic material, which makes it easy to mount the electronic components 5 on the substrate portion 2 without the need for an insulating layer.

[0032] In particular, the heat exchanger substrate 1 is made of at least one ceramic material selected from the group consisting of aluminum nitride, silicon nitride, aluminum oxide, silicon oxide, zirconia, and boron nitride, thereby further improving the cooling efficiency of the electronic components 5. Among these, using aluminum nitride as the material for the heat exchanger substrate 1 is particularly preferable in terms of thermal conductivity, insulation, and the like.

[0033] Furthermore, the semiconductor device 10 in which the semiconductor element 51 is mounted on the first surface 21 as the electronic component 5 can be made to have excellent cooling efficiency for the semiconductor element 51 .

[0034] As described above, according to this embodiment, it is possible to provide a heat exchange substrate and a semiconductor device that can easily improve cooling efficiency.

[0035] (Embodiment 2) In this embodiment, as shown in Fig. 4, the fin portion 3 has a generally T-shaped cross section. That is, the fin portion 3 is composed of a small-diameter cylindrical portion 331 and a large-diameter cylindrical portion 332 formed at the tip side of the small-diameter cylindrical portion 331. The small-diameter cylindrical portion 331 is a cylindrical portion with a relatively small outer diameter that stands upright from the base portion 2. The large-diameter cylindrical portion 332 has a larger outer diameter than the small-diameter cylindrical portion 331.

[0036] In this embodiment, the small-diameter cylindrical portion 331 corresponds to the above-mentioned minimum cross-sectional area portion 321. The large-diameter cylindrical portion 332 corresponds to the above-mentioned large cross-sectional area portion 322 and also to the maximum cross-sectional area portion 323. An undercut surface 31 is formed in the portion of the large-diameter cylindrical portion 332 that protrudes outward from the small-diameter cylindrical portion 331. In this embodiment, the undercut surface 31 faces the second surface 22 and is substantially parallel to it.

[0037] Other aspects are the same as those of embodiment 1. Note that, of the symbols used in embodiment 2 and onward, the same symbols as those used in the previous embodiments represent the same components as those in the previous embodiments, unless otherwise specified. This embodiment also has the same effects as embodiment 1.

[0038] 5, a modification of this embodiment may be made in which a spherical portion 333 having a substantially spherical shape is provided at the tip of the fin portion 3 instead of the large-diameter cylindrical portion 332. In this case, a part of the surface of the spherical portion 333 becomes the undercut surface 31.

[0039] Third Embodiment In this embodiment, as shown in FIGS. 6 and 7, the fin portion 3 has a minimum cross-sectional area portion 321 at the center in the protruding direction.

[0040] The fin portion 3 has a generally conical shape with opposite directions on the base side and tip side of the minimum cross-sectional area portion 321. That is, the fin portion 3 has a tapered shape in which the outer diameter gradually increases from the minimum cross-sectional area portion 321 toward the base side, and also gradually increases from the minimum cross-sectional area portion 321 toward the tip side. The tapered surface from the minimum cross-sectional area portion 321 to the tip portion becomes the undercut surface 31.

[0041] In this embodiment, at least a portion of the large cross-sectional area portion 322 is provided closer to the tip than the minimum cross-sectional area portion 321. In this embodiment, the maximum cross-sectional area portion 323 is provided at the tip and base of the fin portion 32. Therefore, the maximum cross-sectional area portion 323 is provided in the tip region 302 (see FIG. 2).

[0042] Other aspects are the same as those of the first embodiment. This embodiment also has the same effects as those of the first embodiment.

[0043] 8 and 9 , in this embodiment, the fin portion 3 has a trunk portion 341 extending from the base portion 2 and a plurality of branch portions 342 branching off from the trunk portion 341. A portion of the surface of the branch portion 342 forms the undercut surface 31.

[0044] The fin portion 3 shown in Fig. 8 has a configuration in which two branch portions 342 branch off from a trunk portion 341. The fin portion 3 shown in Fig. 9 has a configuration in which the branch portions 342 further branch off. Note that these figures are shown as schematic cross-sectional views, but the branch portions 342 may protrude three-dimensionally in various directions. That is, the branch portions 342 may protrude in a direction intersecting the plane of the paper in Figs. 8 and 9.

[0045] Other aspects are the same as those of the first embodiment. This embodiment also has the same effects as those of the first embodiment.

[0046] 10 to 13, in this embodiment, the fin portion 3 has a plurality of leg portions 351 protruding from the substrate portion 2 and connecting portions 352 connecting the plurality of leg portions 351. A through space 350 is formed between the plurality of leg portions 351.

[0047] 10 and 11 , two legs 351 protrude in the Z direction relative to the substrate 2. The tips of the legs 351 are connected to each other by a connecting portion 352. A through space 350 is formed between the two legs 351, the connecting portion 352, and the substrate 2. The surface of the connecting portion 352 facing the substrate 2 forms an undercut surface 31.

[0048] The fin portion 3 shown in Figures 12 and 13 has two legs 351 that are inclined with respect to the Z direction. The two legs 351 are inclined in opposite directions with respect to the Z direction, and their tips are connected to each other. The fin portion 3 extends further from this connecting portion 352 toward the tip in the Z direction. A through space 350 is formed between the two legs 351 and the substrate portion 2. In addition, the surfaces of the two legs 351 that face the through space 350 form undercut surfaces 31.

[0049] In this embodiment, the through space 350 penetrates in the Y direction, that is, in the direction in which the coolant flows in the coolant flow channel 11. The rest is the same as in the first embodiment.

[0050] In this embodiment, the cooling efficiency of the substrate 2 can be improved by circulating the refrigerant through the through space 350. As a result, the electronic components 5 mounted on the substrate 2 can be efficiently cooled. In addition, the same effects as those of the first embodiment are achieved.

[0051] Sixth Embodiment In this embodiment, as shown in Fig. 14, the fin portion 3 has a straight rod shape inclined with respect to the Z direction. The inclination angle of the fin portion 3 with respect to the Z direction can be, for example, 45° or less. The inclination directions or inclination angles of the multiple fin portions 3 can be different from one another. The inclination directions and inclination angles of the multiple fin portions 3 can also be the same.

[0052] In this embodiment, an undercut surface 31 is also formed on a part of the surface of the fin portion 3. The rest is the same as in the first embodiment, and the same effects are obtained.

[0053] 15 and 16 , in this embodiment, a plurality of grooves 36 are formed on the side surfaces of the fin portion 3. In this embodiment, the grooves 36 are formed around the entire periphery of the fin portion 3 on a plane parallel to the substrate portion 2. Therefore, the grooves 36 are formed continuously across the entire width of the fin portion 3 in the Y direction. This also means that the grooves 36 are formed continuously across the entire width of the fin portion 3 in the X direction.

[0054] A part of the inner surface of the groove portion 36 becomes the undercut surface 31. Therefore, in this embodiment, the undercut surface 31 is also formed over the entire circumference of the fin portion 3. Therefore, the undercut surface 31 is formed continuously over the entire width of the fin portion 3 in the Y direction. The undercut surface 31 is also formed continuously over the entire width of the fin portion 3 in the X direction. The rest is the same as in the first embodiment.

[0055] In this embodiment, the pressure loss of the refrigerant can be reduced, and the refrigerant can be efficiently brought into contact with the outer peripheral surface of the fin portion 3. In addition, the same effects as those of the first embodiment are obtained.

[0056] 17 and 18 , in this embodiment, an uneven shape is provided on the side surface of the fin portion 3. In this embodiment, the uneven shape is formed by a plurality of independent recesses 371 or protrusions 372. Undercut surfaces 31 are formed on parts of the inner surfaces of the recesses 371 and the protrusions 372.

[0057] 17 shows the fin section 3 provided with the convex portion 372, and Fig. 18 shows the fin section 3 provided with the concave portion 371, but it is also possible to have the fin section 3 provided with both the concave portion 371 and the convex portion 372. The rest is the same as in the first embodiment.

[0058] Ninth Embodiment In this embodiment, as shown in FIGS. 19 and 20, the heat exchanger substrate 1 has a plurality of fin portions 3 having a plurality of different shapes.

[0059] That is, the shapes of the multiple fin portions 3 in the heat exchanger substrate 1 are different from one another. Specifically, for example, in the example shown in Figures 19 and 20, the heat exchanger substrate 1 has fin portions 3A and 3B of two different shapes. Here, the shapes of the fin portions 3A and 3B are generally similar to the shapes of the fin portion 3 shown in embodiment 1 (see Figures 1 and 2). However, the outer shape of the tip of the fin portion 3B is formed larger than that of the fin portion 3A. Accordingly, the volume of the tip side region 302 of the fin portion 3B is larger than the volume of the tip side region 302 of the fin portion 3A.

[0060] In this embodiment, the fin portion 3A is arranged on the upstream side of the refrigerant flow path 11, and the fin portion 3B is arranged on the downstream side.

[0061] In this embodiment, it is possible to change the heat exchange efficiency between the refrigerant and the heat exchange substrate 1 depending on the position of the substrate portion 2. As described above, by arranging the fin portion 3A on the upstream side of the refrigerant flow path 11 and the fin portion 3B on the downstream side, it is possible to increase the flow rate or flow speed of the refrigerant near the substrate portion 2 in the downstream region where the refrigerant temperature is relatively high. This is thought to suppress variations in cooling performance between the upstream and downstream sides of the refrigerant. Other effects are similar to those of the first embodiment.

[0062] In addition to the above, there are various other ways to arrange the fin portions 3 with different shapes. For example, it is possible to arrange fin portions 3 with different shapes at both ends and the center in the width direction of the refrigerant flow path 11, i.e., in the Y direction. Furthermore, the heat exchanger substrate 1 can be provided with fin portions 3 with three or more shapes.

[0063] (Reference Embodiment 1) In this embodiment, as shown in Figs. 21 and 22, the opposing wall portion 4 on the opposite side of the substrate portion 2 across the refrigerant flow path 11 is also integrally molded as part of the heat exchange substrate 8.

[0064] 21 and 22, some of the fins 3 are connected to the opposing wall 4. In addition to the fins 3 that stand directly on the second surface 22 of the substrate 2, the heat exchanger substrate 8 also has a plurality of opposing fins 43 that protrude from the opposing wall 4 toward the substrate 2.

[0065] 23 and 24 , this embodiment is also a form of a heat exchanger substrate 8 in which the opposing wall portion 4 is also integrally molded as part of the heat exchanger substrate 8. A plurality of fin portions 3 are connected to the opposing wall portion 4. A refrigerant flow path 11 is formed between adjacent fin portions 3, the substrate portion 2, and the opposing wall portion 4.

[0066] The present disclosure is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the spirit of the present disclosure.

[0067] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0068] The features of the present disclosure are as follows: [1] A heat exchanger substrate (1) integrally formed with a substrate portion (2) on which electronic components (5) are mounted on a first surface (21) and a plurality of fin portions (3) protruding from a second surface (22) of the substrate portion opposite the first surface, wherein the plurality of fin portions (3) are arranged along the second surface and in two directions intersecting each other, and the fin portion has an undercut surface (31) on a part of its outer surface, the undercut surface having a normal vector that includes a vector component pointing toward the substrate portion. [2] The heat exchanger substrate according to [1], wherein the cross-sectional area of ​​the fin portion taken along a plane parallel to the substrate portion varies depending on the distance from the substrate portion, and at least a part of a large cross-sectional area portion (322) having a cross-sectional area larger than a minimum cross-sectional area portion (321) at which the cross-sectional area is smallest is provided closer to the tip than the minimum cross-sectional area portion. [3] The heat exchanger substrate according to [1] or [2], wherein the cross-sectional area of ​​the fin portion taken along a plane parallel to the substrate portion varies depending on the distance from the substrate portion, and the volume of the tip-side region (302) from half the protrusion height (h) to the tip is larger than the volume of the base-side region (301) from the second surface to half the protrusion height (h). [4] The heat exchanger substrate according to any of [1] to [3], wherein the cross-sectional area of ​​the fin portion taken along a plane parallel to the substrate portion varies depending on the distance from the substrate portion, and a maximum cross-sectional area portion (323) where the cross-sectional area is largest is provided in the tip-side region (302) from half the protrusion height (h) to the tip. [5] The heat exchanger substrate according to any of [1] to [4], wherein the fin portion has a plurality of legs (351) protruding from the substrate portion and connecting portions (352) connecting the plurality of legs, and a through space (350) is formed between the plurality of legs. [6] The heat exchanger substrate according to any one of [1] to [5], wherein the fin portions have a plurality of different shapes. [7] The heat exchanger substrate according to any one of [1] to [6], which is made of a ceramic material. [8] The heat exchanger substrate according to [7], which is made of at least one ceramic material selected from the group consisting of aluminum nitride, silicon nitride, aluminum oxide, silicon oxide, zirconia, and boron nitride.[9] The heat exchanger substrate according to any one of [1] to [8], wherein the undercut surface is continuously formed across the entire width of the fin portion along one direction parallel to the substrate portion.

[10] A semiconductor device (10) comprising the heat exchanger substrate according to any one of [1] to [9], and a semiconductor element (51) mounted on the first surface of the heat exchanger substrate.

Claims

1. A heat exchange substrate (1) in which a substrate portion (2) on which electronic components (5) are mounted on a first surface (21) and a plurality of fin portions (3) protruding from a second surface (22) of the substrate portion opposite the first surface are integrally molded, wherein the plurality of fin portions (3) are arranged along the second surface and in two directions that intersect with each other, and the fin portions have an undercut surface (31) on a part of their outer surface, the normal vector of which is a vector that includes a vector component pointing toward the substrate portion.

2. A heat exchange substrate as described in claim 1, wherein the cross-sectional area of ​​the fin portion taken along a plane parallel to the substrate portion varies depending on the distance from the substrate portion, and at least a portion of the large cross-sectional area portion (322) having a larger cross-sectional area than the minimum cross-sectional area portion (321) where the cross-sectional area is smallest is located closer to the tip than the minimum cross-sectional area portion.

3. A heat exchange substrate as described in claim 1 or 2, wherein the cross-sectional area of ​​the fin portion taken along a plane parallel to the base portion varies depending on the distance from the base portion, and the volume of the tip side region (302) from half the protrusion height (h) to the tip is greater than the volume of the base side region (301) from the second surface to half the protrusion height (h).

4. A heat exchange substrate as described in claim 1 or 2, wherein the cross-sectional area of ​​the fin portion in a plane parallel to the base portion varies depending on the distance from the base portion, and the maximum cross-sectional area portion (323) where the cross-sectional area is the largest is provided in the tip side region (302) from a position halfway through the protrusion height (h) to the tip portion.

5. A heat exchange substrate as described in claim 1 or 2, wherein the fin portion has a plurality of leg portions (351) protruding from the base portion and connecting portions (352) connecting the plurality of leg portions, and a through space (350) is formed between the plurality of leg portions.

6. The heat exchanger substrate according to claim 1 or 2, wherein the plurality of fin portions have a plurality of different shapes.

7. The heat exchange substrate according to claim 1 or 2, which is made of a ceramic material.

8. The heat exchange substrate according to claim 7, which is made of at least one ceramic material selected from the group consisting of aluminum nitride, silicon nitride, aluminum oxide, silicon oxide, zirconia, and boron nitride.

9. A heat exchanger substrate according to claim 1 or 2, wherein the undercut surface is formed continuously across the entire width of the fin portion in one direction parallel to the substrate portion.

10. A semiconductor device (10) comprising the heat exchange substrate according to claim 1 or 2, and a semiconductor element (51) mounted on the first surface of the heat exchange substrate.

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