Semiconductor device

Abstract

The invention relates to a semiconductor device. A heat dissipation substrate can be positioned with high precision with respect to a cooling case without requiring a complicated structure. A semiconductor device (1) is provided with an insulating substrate (14), semiconductor elements (12, 13) mounted on the insulating substrate, and a cooler (20) for cooling the semiconductor elements. The cooler is provided with: a heat dissipation substrate (21) joined to the insulating substrate; a plurality of fins (22) provided on the heat dissipation surface of the heat dissipation substrate, said heat dissipation surface being on the opposite side from the joining surface of the heat dissipation substrate and the insulating substrate; and a cooling case (23) having a recess (24) for accommodating the fins. The heat dissipation surface is provided with a plurality of positioning engagement pieces (221, 222) that engage with a part of the inner wall surface of the recess of the cooling case.

Description

[0001] This application is a divisional application of an application with an international application date of September 9, 2019 (date of entry into the Chinese national phase: September 30, 2020), an international application number of PCT / JP2019 / 035398 (national application number: 201980024342.8), and an invention name of “Semiconductor Device”. Technical Field

[0002] The present invention relates to a semiconductor device including a cooler for cooling a semiconductor element. Background Art

[0003] In hybrid vehicles and electric vehicles, a power conversion device is used to variably drive a motor. In the power conversion device, a semiconductor module (power semiconductor module) having a plurality of power semiconductor elements is used. Generally, a power semiconductor element generates heat when controlling a large current, and as the power conversion device is miniaturized and has a higher output, the heat generated increases.

[0004] In the past, a semiconductor device with a refrigerant type cooler has been proposed to cool a power semiconductor module. For example, such a refrigerant type cooler includes: a metal heat dissipation substrate that is bonded to a surface of an insulating substrate on which a power semiconductor element is mounted that is opposite to the semiconductor module; fins for heat dissipation that are formed integrally with the heat dissipation substrate; and a box-shaped cooling housing that accommodates the fins and is liquid-tightly mounted on the heat dissipation substrate. By allowing a cooling medium pressurized by an external pump to flow through a flow path in the cooling housing, the heat energy of the power semiconductor element is dissipated to the cooling medium via the fins.

[0005] In a semiconductor device having such a cooler, it is required to install a heat dissipation substrate at an appropriate position relative to the cooling housing. In the past, a semiconductor device has been proposed in which a recess is provided in a part of the cooling housing where a refrigerant flow path is formed, a protrusion that fits into the recess is provided in a part of a cooling fin base constituting the heat dissipation substrate, and the cooling fin base is installed at an appropriate position relative to the cooling housing (for example, see Patent Document 1).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2016-92209 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] However, in the semiconductor device described in Patent Document 1, it is necessary to provide a positioning structure in both the cooling case and the cooling fin base, which causes a problem that the components constituting the semiconductor device become complicated.

[0011] The present invention has been made in view of the above problem, and one object of the present invention is to provide a semiconductor device capable of positioning a heat dissipating substrate with respect to a cooling case with high accuracy without requiring a complicated structure.

[0012] Solutions for solving problems

[0013] The semiconductor device of this embodiment includes: an insulating substrate having a first surface and a second surface on the side opposite to the first surface; a semiconductor element mounted on the first surface of the insulating substrate; and a cooler for cooling the semiconductor element. The semiconductor device is characterized in that the cooler includes: a heat dissipation substrate having a bonding surface and a heat dissipation surface on the side opposite to the bonding surface, the bonding surface being bonded to the second surface of the insulating substrate; a plurality of fins provided on the heat dissipation surface of the heat dissipation substrate; and a cooling shell having a recess for accommodating the plurality of fins, and a plurality of positioning engaging pieces provided on the heat dissipation surface for partially engaging with the inner wall surface of the recess of the cooling shell.

[0014] Effects of the Invention

[0015] According to the present invention, the heat dissipation substrate can be positioned with respect to the cooling case with high accuracy without requiring a complicated structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a perspective view of a semiconductor device according to this embodiment.

[0017] Figure 2 The diagram is a perspective view and a plan view of a cooling case included in the semiconductor device according to the present embodiment.

[0018] Figure 3 It is an explanatory diagram of fins provided on a heat dissipation substrate of the semiconductor device according to the present embodiment.

[0019] Figure 4 It is an explanatory diagram of the flow of the cooling medium in the semiconductor device according to the present embodiment.

[0020] Figure 5 is along Figure 4 The cross-sectional view is taken along the line AA shown.

[0021] Figure 6 This is a perspective view of a state where a resin case is mounted on the semiconductor device according to the present embodiment. DETAILED DESCRIPTION

[0022] Hereinafter, a structure of a semiconductor device according to this embodiment will be described with reference to the drawings. Figure 1 It is a perspective view of a semiconductor device according to this embodiment. Figure 2 1 is a perspective view and a top view of a cooling housing included in the semiconductor device according to the present embodiment. Figure 1 In A, a heat dissipation substrate 21 included in the semiconductor device 1 according to the present embodiment is shown. Figure 1 In B, a cooling housing 23 to which the heat dissipation substrate 21 is mounted is shown. Figure 2 A means to make Figure 1 B shows a diagram of the cooling housing 23 after rotation. Figure 2 In B, the cooling housing 23 is shown from above. Figure 1 The vertical direction, horizontal direction, and front-back direction shown are explained as the vertical direction, horizontal direction, and front-back direction of the semiconductor device. In this specification, a top view refers to a state where the upper surface of the semiconductor device is viewed from above.

[0023] like Figure 1 As shown, the semiconductor device 1 according to the present embodiment is configured to include a semiconductor module 10 and a cooler 20 for cooling the semiconductor module 10. The semiconductor module 10 has a plurality of circuit element portions 11A, 11B, and 11C arranged on a heat dissipation substrate 21 of the cooler 20 described later. For example, the semiconductor module 10 uses these circuit element portions 11A, 11B, and 11C to form a three-phase inverter circuit. For example, the circuit element portions 11A, 11B, and 11C respectively form a W-phase circuit, a V-phase circuit, and a U-phase circuit for forming a three-phase inverter circuit.

[0024] like Figure 1 As shown in FIG. 1A , the circuit element section 11A constituting the W-phase circuit includes an IGBT element 12 constituting an upper arm as a semiconductor element and a flyback diode 13 connected in anti-parallel to the IGBT element 12, and an IGBT element 12 constituting a lower arm and a flyback diode 13 connected in anti-parallel to the IGBT element 12. The IGBT element 12 and the flyback diode 13 are mounted on an insulating substrate 14 bonded to a heat dissipation substrate 21.

[0025] The circuit element portion 11B constituting the V-phase circuit and the circuit element portion 11C constituting the U-phase circuit also have the same structure as the circuit element portion 11A. A circuit pattern for constituting the above-mentioned circuits is formed on the insulating substrate 14. In addition, here, the case where the semiconductor module 10 constitutes a three-phase inverter circuit is described. However, the semiconductor module 10 involved in the present invention is not limited to the case of constituting a three-phase inverter circuit, and can be appropriately changed.

[0026] The cooler 20 is composed of Figure 1 The heat dissipation substrate 21 shown in A and the plurality of fins 22 provided on the heat dissipation substrate 21 (see Figure 3 ), Figure 1 B shows a cooling case 23. As will be described in detail later, the fins 22 are provided on the surface (heat dissipation surface) of the heat dissipation substrate 21 opposite to the surface (bonding surface) bonded to the insulating substrate 14. The heat dissipation substrate 21 is mounted on the upper portion of the cooling case 23. The plurality of fins 22 provided on the lower surface (heat dissipation surface) of the heat dissipation substrate 21 are accommodated in a recess 24 formed in the cooling case 23. In addition, the cooling case 23 is sometimes referred to as a refrigerant jacket or a water jacket.

[0027] like Figure 1 As shown in A, the heat dissipation substrate 21 is composed of a metal plate having a substantially rectangular shape. For example, the heat dissipation substrate 21 is composed of a metal material such as aluminum, copper, and iron. For the heat dissipation substrate 21, its length direction extends along the left-right direction of the semiconductor device 1, and its width direction extends along the front-back direction of the semiconductor device 1. The semiconductor module 10 is arranged in the central area of ​​the upper surface of the heat dissipation substrate 21. In the present embodiment, the circuit element parts 11A, 11B, and 11C constituting the semiconductor module 10 are arranged in the left-right direction in the central area of ​​the heat dissipation substrate 21. In addition, threaded holes 211 are formed through the four corners of the heat dissipation substrate 21. Screws (fastening members) for fixing the heat dissipation substrate 21 to the cooling housing 23 are inserted through the threaded holes 211.

[0028] like Figure 1 B and Figure 2 As shown, the cooling shell 23 has a generally rectangular shape, and has a rectangular shape when viewed from above. The outer shape of the cooling shell 23 when viewed from above has substantially the same shape as the outer shape of the heat dissipation substrate 21. The cooling shell 23 has a bottom wall 231 and a side wall 232 provided on the periphery of the bottom wall 231, and has a box-like shape with an upper opening. In other words, a recess 24 is formed on the upper surface of the cooling shell 23. The recess 24 is defined by the upper surface of the bottom wall 231, the inner wall surface of the side wall 232, the upper surface (inclined surface) of the diffusion wall 237 described later, and the upper surface (inclined surface) of the converging wall 238 described later. The recess 24 has a rectangular shape with its length direction arranged in the left-right direction of the semiconductor device 1 when viewed from above (refer to Figure 2 B).

[0029] The cooling housing 23 is provided with an inlet 233 for introducing a cooling medium into the cooling housing 23 and an outlet 234 for discharging the cooling medium from the cooling housing 23. The inlet 233 and the outlet 234 are respectively provided at a portion of the first side wall 232a and the second side wall 232b extending in the longitudinal direction. The inlet 233 is arranged at one end portion ( Figure 1The outlet 234 is located near the right side end portion shown in FIG. 2 and is connected to the recess 24. The outlet 234 is located at the other end portion ( Figure 1 The inlet 233 and the outlet 234 are arranged at positions offset in opposite directions from the center line CL1 in the longitudinal direction of the recess 24. The inlet 233 is connected to an inlet pipe 233a, and the outlet 234 is connected to an outlet pipe 234a.

[0030] An O-ring 235 is installed on the upper surface of the side wall 232. The O-ring 235 is arranged at a position close to the recess 24 of the side wall 232 and is arranged in a manner to surround the recess 24. The O-ring 235 plays a role in preventing liquid from leaking out of the cooling housing 23 when the heat dissipation substrate 21 is installed relative to the cooling housing 23 and the cooling medium flows through the cooling housing 23. In addition, the structure for preventing liquid from leaking out is not limited to the O-ring 235, and it can also be a metal seal or a liquid gasket.

[0031] Screw holes 236 are formed near the four corners of the cooling housing 23 (side wall 232). The screw holes 236 are arranged at positions corresponding to the screw holes 211 of the heat dissipation substrate 21 when the heat dissipation substrate 21 is overlapped on the cooling housing 23. When the heat dissipation substrate 21 is overlapped on the cooling housing 23, screws (fastening members) are inserted into the screw holes 236 through the screw holes 211 and fastened, so that the heat dissipation substrate 21 is mounted on the cooling housing 23.

[0032] In the recess 24 of the cooling housing 23, a diffusion wall 237 is provided between the bottom wall 231 and the first side wall 232a. In addition, in the recess 24, a convergence wall 238 is provided between the bottom wall 231 and the second side wall 232b. The diffusion wall 237 is arranged on the front side of the bottom wall 231 and connected to the front edge of the bottom wall 231. The convergence wall 238 is arranged on the rear side of the bottom wall 231 and connected to the rear edge of the bottom wall 231. The diffusion wall 237 and the convergence wall 238 extend along the longitudinal direction of the semiconductor device 1. The diffusion wall 237 is composed of an inclined surface, and plays a role in diffusing the cooling medium introduced from the inlet 233 along the first side wall 232a. The convergence wall 238 is composed of an inclined surface, and plays a role in converging the cooling medium in the cooling housing 23 to the discharge port 234 along the second side wall 232b.

[0033] Here, refer to Figure 3 The structure of the fins 22 provided on the lower surface of the heat dissipation substrate 21 will be described. Figure 3 FIG. 2 is an explanatory diagram of the fins 22 provided on the heat dissipation substrate 21 of the semiconductor device 1 according to the present embodiment. Figure 3 A is a perspective view showing a state where the lower surface of the heat dissipation substrate 21 is directed upward. Figure 3 B shows a bottom view of the heat dissipation substrate 21 as viewed from below. Figure 3 In B, for convenience of explanation, the outer shape of the recessed portion 24 when attached to the cooling case 23 is indicated by a dotted line 241 .

[0034] The fins 22 are integrally provided on the lower surface of the heat dissipation substrate 21. The fins 22 may be made of the same metal material as the heat dissipation substrate 21. The fins 22 are used as a heat sink. For example, Figure 3 As shown in FIG. 1 , a pin-shaped fin formed by arranging a plurality of prism-shaped pins (square pins) at a predetermined interval can be used. The structure of the fin 22 provided on the heat dissipation substrate 21 is not limited to this, and can be appropriately changed. For example, it can also be set to replace Figure 3 The structure is a structure in which a cylindrical pin is provided in the prismatic shape shown, and a plurality of blade-shaped fins extending in the front-rear direction are arranged in parallel with each other.

[0035] The shape and size of the fin 22 are preferably appropriately set in consideration of the introduction conditions of the cooling medium into the cooler 20 (i.e., pump performance, etc.), the type and properties of the cooling medium (especially viscosity, etc.), the target heat removal, etc. In addition, the fin 22 is formed to have a certain height (see FIG. 1 ) so that there is a certain gap between the top end of the fin 22 and the bottom wall 231 of the cooling case 23 when the fin 22 is accommodated in the cooling case 23 (more specifically, the recessed portion 24 of the cooling case 23). Figure 5 ).

[0036] In the heat dissipation substrate 21, the region where the fins 22 are provided preferably includes a region on the side (back side) opposite to the mounting region of the semiconductor elements (IGBT element 12, freewheeling diode 13) on the insulating substrate 14 when the insulating substrate 14 and the heat dissipation substrate 21 are bonded. In other words, the region where the fins 22 are integrally provided on the heat dissipation substrate 21 preferably includes a region directly below the IGBT element 12 and the freewheeling diode 13.

[0037] In the present embodiment, a collection 22a of fins 22 formed by arranging a plurality of fins 22 having a prism shape is provided on the lower surface (heat dissipation surface) of the heat dissipation substrate 21. The outer shape of the collection 22a of fins 22 is roughly a rectangular parallelepiped shape. More preferably, the outer shape of the collection 22a of fins 22 is a rectangular parallelepiped shape, but it is not limited to this, and may also be a chamfered or deformed shape. The length direction of the collection 22a of fins 22 is consistent with the length direction of the cooling shell 23 (recess 24). Figure 3, the longitudinal center line CL2 of the assembly 22a of the fins 22 having a substantially rectangular parallelepiped shape is shown. When the heat dissipation substrate 21 is mounted on the cooling housing 23, the center line CL2 is aligned with the longitudinal center line CL1 of the recess 24 (see Figure 2 B) consistent.

[0038] In addition, on the lower surface (heat dissipation surface) of the heat dissipation substrate 21, there are provided snap-fitting pieces 221 and 222 for positioning near the assembly 22a of the fins 22. These snap-fitting pieces 221 and 222 are integrally provided on the lower surface of the heat dissipation substrate 21. The snap-fitting pieces 221 and 222 can be made of the same metal material as the heat dissipation substrate 21. The snap-fitting piece 221 is arranged at a position corresponding to the corner on the left front side of the assembly 22a of the fins 22, and the snap-fitting piece 222 is arranged at a position corresponding to the corner on the right rear side of the assembly 22a of the fins 22. These snap-fitting pieces 221 and 222 are respectively formed by arranging a plurality of (three in the present embodiment) prism-shaped pins (square pins).

[0039] like Figure 3 As shown in FIG. 2B , the engaging piece 221 includes a reference engaging piece 221a disposed corresponding to the corner of the left front side of the heat dissipation substrate 21, and a pair of auxiliary engaging pieces 221b and 221c disposed on the right side and rear side of the reference engaging piece 221a. The reference engaging piece 221a and the auxiliary engaging pieces 221b and 221c may have the same shape. The engaging piece 221 has a structure in which both sides of adjacent prism-shaped pins face the front side and the left side of the semiconductor device 1 when viewed from above.

[0040] In addition, the engaging piece 222 has a reference engaging piece 222a arranged corresponding to the corner of the right rear side of the heat dissipation substrate 21, and a pair of auxiliary engaging pieces 222b and 222c arranged on the front side and left side of the reference engaging piece 222a, similarly to the engaging piece 221. The reference engaging piece 222a and the auxiliary engaging pieces 222b and 222c may have the same shape. The engaging piece 222 has a structure in which both sides of the adjacent prism-shaped pins face the right side and the rear side of the semiconductor device 1 when viewed from above. In addition, the reference engaging piece 222a and the auxiliary engaging pieces 222b and 222c may have the same shape as the reference engaging piece 221a and the auxiliary engaging pieces 221b and 221c.

[0041] These engaging pieces 221 and 222 are used for positioning when the heat dissipation substrate 21 is mounted relative to the cooling housing 23. These engaging pieces 221 and 222 engage with a part of the inner wall surface of the recessed portion 24 of the cooling housing 23 when the heat dissipation substrate 21 is mounted relative to the cooling housing 23, and play a role in determining the position of the heat dissipation substrate 21 relative to the cooling housing 23. The engaging pieces 221 and 222 engage with the inner wall surfaces of the corners 242 and 243 arranged diagonally in the recessed portion 24, respectively. More specifically, the engaging piece 221 engages with the inner wall surface of the corner 242 on the left front side of the recessed portion 24, and the engaging piece 222 engages with the inner wall surface of the corner 243 on the right rear side of the recessed portion 24.

[0042] The reference engaging pieces 221a and 222a constitute a pair of engaging pieces, and each has an outer shape corresponding to the shape of the corners 242 and 243 of the recessed portion 24. The reference engaging pieces 221a and 222a have a square cross-sectional shape, and their right-angled portions respectively engage with the corners 242 and 243 of the recessed portion 24. The auxiliary engaging pieces 221b and 221c and the auxiliary engaging pieces 222b and 222c respectively constitute auxiliary engaging pieces arranged around the reference engaging piece 221a and the reference engaging piece 222a, and engage with a part of the inner wall surface of the recessed portion 24.

[0043] On the lower surface (heat dissipation surface) of the heat dissipation substrate 21, the interval between the reference snap-fit ​​piece 221a and the auxiliary snap-fit ​​pieces 221b and 221c is set to be narrower than the interval between the fins 22 constituting the collection 22a of the fins 22. As will be described in detail later, this is to prevent the cooling medium introduced into the cooling housing 23 from easily entering the gap between the reference snap-fit ​​piece 221a and the auxiliary snap-fit ​​pieces 221b and 221c. The same is true for the interval between the reference snap-fit ​​piece 222a and the auxiliary snap-fit ​​pieces 222b and 222c. In addition, from the viewpoint of suppressing the degradation of thermal resistance and pressure loss, it is preferred to eliminate the gap between the reference snap-fit ​​piece 221a (222a) and the auxiliary snap-fit ​​pieces 221b and 221c (222b, 222c).

[0044] In addition, the size of the engaging pieces 221 and 222 is preferably appropriately set in consideration of the introduction conditions (i.e., pump performance, etc.) of the cooling medium into the cooling housing 23, the type and properties (especially viscosity, etc.) of the cooling medium, and the like. For example, the size of each engaging piece constituting the engaging pieces 221 and 222 is set to a length of 5 mm on one side and a height of 3 mm to 5 mm. By setting the length of one side to 5 mm, it is possible to appropriately contact a part of the inner wall surface of the recess 24. In addition, by setting the height to 3 mm to 5 mm, a gap can be formed between the lower surface of the recess 24, which can facilitate the flow of the cooling medium.

[0045] Figure 4 In the Figure 1The heat dissipation substrate 21 shown in A is mounted on Figure 1 B is a top view of the cooling housing 23. Figure 5 The middle represents the Figure 4 A-A line cut-off view. In addition, Figure 4 and Figure 5 In order to facilitate understanding of the present invention, the structural elements on the heat dissipation substrate 21 are omitted. Figure 4 In FIG. 2 , for convenience of explanation, the fin 22 and the engaging pieces 221 and 222 provided on the lower surface of the heat dissipation substrate 21 are shown, and the flow of the cooling medium in the recess 24 is shown by arrows.

[0046] When the heat dissipation substrate 21 is mounted on the cooling housing 23, as shown in FIG. Figure 4 As shown, the engaging pieces 221 and 222 are engaged with the inner wall surface of the recess 24. More specifically, the engaging piece 221 is engaged with the inner wall surface of the corner 242 of the recess 24, and the engaging piece 222 is engaged with the inner wall surface of the corner 243 of the recess 24. Thus, the heat dissipation substrate 21 is positioned relative to the cooling housing 23. In this state, the screws (not shown) are inserted through the threaded holes 211 of the heat dissipation substrate 21 into the threaded holes 236 of the cooling housing 23, thereby fastening the heat dissipation substrate 21 to the upper surface of the cooling housing 23. In this way, when the heat dissipation substrate 21 is installed in the cooling housing 23, the cooling medium is introduced into the cooling housing 23.

[0047] like Figure 5 As shown, the diffusion wall 237 is composed of an ascending inclined surface formed from the bottom edge of the first side wall 232a toward the bottom wall 231. In addition, the converging wall 238 is composed of a descending inclined surface formed from the bottom wall 231 toward the bottom edge of the second side wall 232b. By forming the diffusion wall 237 and the converging wall 238 with inclined surfaces, eddy currents that may be generated when the diffusion wall 237 and the converging wall 238 are arranged perpendicularly to the inlet 233 and the outlet 234 are suppressed.

[0048] Since the diffusion wall 237 is provided in the cooling shell 23, the cooling medium introduced from the inlet 233 collides with the diffusion wall 237 and flows along the diffusion wall 237 in the longitudinal direction (more specifically, Figure 4 Then, the cooling medium diffuses in the width direction of the cooling housing 23 (more specifically, Figure 4 The cooling medium then flows along the converging wall 238 and converges, and is discharged from the discharge port 234 to the outside of the cooling housing 23.

[0049] Thus, in the semiconductor device 1, a plurality of engagement pieces 221 and 222 for positioning that engage with a part of the inner wall surface of the recess 24 of the cooling case 23 are provided on the lower surface (heat dissipation surface) of the heat dissipation substrate 21. Therefore, the heat dissipation substrate 21 can be positioned relative to the cooling case 23 by utilizing a part of the recess 24 that accommodates the fins 22. Thus, the heat dissipation substrate 21 can be positioned with high precision relative to the cooling case 23 without requiring a complicated structure.

[0050] In particular, the engaging pieces 221, 222 include a pair of reference engaging pieces 221a, 222a, which engage with corners 242, 243 arranged diagonally in the recess 24. Thus, the heat dissipation substrate 21 can be positioned relative to the cooling housing 23 by the corners 242, 243 arranged diagonally in the recess 24, and thus, the positional deviation of the heat dissipation substrate 21 relative to the cooling housing 23 can be effectively prevented.

[0051] In addition, the reference engaging pieces 221a and 222a are configured to engage with corners 242 and 243 of the corners continuous with the first side wall 232a and the second side wall 232b, respectively, which are arranged at a position away from the inlet 233 or the outlet 234 (see Figure 4 Thus, the heat dissipation substrate 21 can be positioned relative to the cooling case 23 without reducing the flow rate of the cooling medium introduced from the introduction port 233 or discharged from the discharge port 234 .

[0052] Moreover, the reference engaging pieces 221a and 222a have an outer shape corresponding to the shape of the corners 242 and 243 continuous with the first side wall 232a and the second side wall 232b. Thus, the shape of the corners 242 and 243 of the recessed portion 24 can be used to effectively position the heat dissipation substrate 21 relative to the cooling housing 23. More specifically, the reference engaging pieces 221a and 222a are configured to have a square cross-sectional shape, and the right-angled portions are engaged with the corners 242 and 243. Since the right-angled portions of the reference engaging pieces 221a and 222a are engaged with the corners 242 and 243, the heat dissipation substrate 21 can be reliably positioned relative to the cooling housing 23.

[0053] Auxiliary engaging pieces 221b, 221c and auxiliary engaging pieces 222b, 222c are respectively provided around the reference engaging piece 221a and the reference engaging piece 222a to engage with a part of the inner wall surface of the recess 24. Thus, not only the reference engaging pieces 221a, 222a but also a plurality of engaging pieces can be used to engage with the inner wall surface of the recess 24, so that the heat dissipation substrate 21 can be positioned relative to the cooling housing 23 while ensuring strength.

[0054] In addition, the interval between the reference engaging piece 221a (222a) and the auxiliary engaging pieces 221b, 221c (222b, 222c) is set to be narrower than the interval between the fins 22 constituting the assembly 22a of the fins 22. As a result, it is possible to prevent the cooling medium introduced into the cooling housing 23 from easily entering the gap between the reference engaging piece 221a (222a) and the auxiliary engaging pieces 221b, 221c (222b, 222c). As a result, when the engaging piece 221 (222) is provided, the influence of the engaging piece 221 (222) on the flow rate of the cooling medium introduced into the cooling housing 23 can also be reduced.

[0055] In addition, the engaging pieces 221 and 222 can be made of the same metal material as the heat dissipation substrate 21. Thus, the engaging pieces 221 and 222 can be manufactured by the manufacturing process of the heat dissipation substrate 21, and therefore, there is no need to add a special process to form the engaging pieces 221 and 222. Therefore, the engaging pieces 221 and 222 can be formed on the heat dissipation substrate 21 by using the existing manufacturing process without adding a special manufacturing process.

[0056] Furthermore, in the semiconductor device 1, the heat dissipation substrate 21 is fastened to the cooling housing 23 by screws (fastening members) in a state where the engaging pieces 221 and 222 are partially engaged with the inner wall surface of the recess 24. Thus, the heat dissipation substrate 21 can be fixed in a state where the heat dissipation substrate 21 is positioned in the cooling housing 23, and degradation of the cooling performance of the cooler 20 and poor fastening caused by positional deviation of the heat dissipation substrate 21 can be prevented.

[0057] Here, Figure 6 1 is a perspective view showing a semiconductor device 1 in which a resin case 15 housing a semiconductor module 10 is attached to the peripheral edge of a heat dissipation substrate 21 constituting a cooler 20. Figure 6 When the resin case 15 is mounted on the heat dissipation substrate 21, the length and width of the resin case 15 when viewed from above are substantially the same as those of the cooler 20 (cooling case 23).

[0058] The P terminal and N terminal 16, U terminal, V terminal and W terminal 17 connected to the circuit of the semiconductor module 10 protrude from the upper surface of the resin case 15. The P terminal and N terminal 16, U terminal, V terminal and W terminal 17 are respectively arranged along the length direction of the cooling case 23. It is also possible to arrange at least one of these terminals 16 and 17 along the width direction of the cooling case 23. However, if Figure 1As shown, when a plurality of IGBT elements 12 and freewheeling diodes 13 are arranged in parallel as circuit element parts 11A, 11B, and 11C along the length direction of the heat dissipation substrate 21, by arranging the terminals 16 and 17 along the length direction of the cooling housing 23, the inductance between these terminals 16 and 17 and the IGBT elements 12 and freewheeling diodes 13 can be reduced compared to the case where they are arranged along the width direction. In addition, by arranging the terminals 16 and 17 along the length direction of the cooling housing 23, the plurality of circuit element parts 11A, 11B, and 11C having a plurality of IGBT elements 12 connected to these terminals can be arranged close to each other. Thus, the fins 22 for dissipating heat from the circuit element parts 11A, 11B, and 11C can be formed into a single assembly, so that the fins 22 are easy to manufacture, and the manufacturing cost of the fins 22 can be reduced.

[0059] In addition, the present invention is not limited to the above-mentioned embodiment, and various changes can be made to implement. In the above-mentioned embodiment, the size, shape, function, etc. of the structural elements illustrated in the drawings are not limited thereto, and can be appropriately changed within the scope of the effect of the present invention. In addition, as long as it does not depart from the scope of the purpose of the present invention, it can be appropriately changed to implement.

[0060] For example, in the above embodiment, the recess 24 provided in the cooling housing 23 has a substantially rectangular shape. However, the shape of the recess 24 is not limited thereto and can be changed appropriately. For example, the recess 24 can also be changed to a rectangular shape such as a square.

[0061] In addition, in the above-mentioned embodiment, the case where the engaging pieces 221 and 222 provided on the heat dissipation substrate 21 are respectively engaged with the corners 242 and 243 arranged diagonally in the recess 24 is described. However, the structure of the engaging piece engaged with the inner wall surface of the recess 24 is not limited to this, and can be appropriately changed. For example, it is also possible to have an engaging piece engaged with a corner other than the corners 242 and 243. However, in this case, it is necessary to appropriately change the position of the inlet 233 or the outlet 234. In addition, the engaging pieces 221 and 222 can also be provided with a structure that engages with a portion other than the corners 242 and 243 on the premise of partial engagement with the inner wall surface of the recess 24.

[0062] Furthermore, in the above-mentioned embodiment, the engaging pieces 221 and 222 provided on the lower surface (heat dissipation surface) of the heat dissipation substrate 21 are illustrated as being composed of a plurality of engaging pieces. However, the structure of the engaging pieces 221 and 222 is not limited thereto, and can be appropriately changed. For example, the engaging pieces 221 and 222 can also be composed of a single engaging piece having a square or right-angled triangle cross-sectional shape, respectively.

[0063] When a single engaging piece having a right triangle cross-sectional shape is applied, it is preferred that the right-angled shape portion engages with the corners 242 and 243 of the recess 24. In this case, the contact area between the engaging piece and the cooling medium introduced into the cooling housing 23 can be reduced. Thus, the influence of the engaging piece on the flow rate of the cooling medium introduced into the cooling housing 23 can be further reduced.

[0064] The characteristic points of the above-mentioned embodiments are summarized below.

[0065] The semiconductor device involved in the above embodiment includes: an insulating substrate having a first surface and a second surface on the side opposite to the first surface; a semiconductor element mounted on the first surface of the insulating substrate; and a cooler for cooling the semiconductor element, and the semiconductor device is characterized in that the cooler includes: a heat dissipation substrate having a bonding surface and a heat dissipation surface on the side opposite to the bonding surface, the bonding surface being bonded to the second surface of the insulating substrate; a plurality of fins provided on the heat dissipation surface of the heat dissipation substrate; and a cooling housing having a recess for accommodating the plurality of fins, and a plurality of positioning engaging pieces that are partially engaged with the inner wall surface of the recess of the cooling housing are provided on the heat dissipation surface. According to this structure, since the positioning engaging pieces that are partially engaged with the inner wall surface of the recess of the cooling housing are provided on the heat dissipation surface of the heat dissipation substrate, the positioning of the heat dissipation substrate relative to the cooling housing can be performed by utilizing the part of the recess for accommodating the fins. As a result, the heat dissipation substrate can be positioned with high precision relative to the cooling housing without a complicated structure.

[0066] In the semiconductor device according to the above embodiment, the plurality of fins are provided in a substantially rectangular region of the heat dissipation surface in a plan view, the recess of the cooling housing has a substantially rectangular shape, and the plurality of engaging pieces include a pair of engaging pieces engaged with corners arranged diagonally in the recess. According to this structure, since the plurality of engaging pieces include a pair of engaging pieces engaged with corners arranged diagonally in the recess, the heat dissipation substrate can be positioned relative to the cooling housing by the corners arranged diagonally in the recess, and thus, the positional deviation of the heat dissipation substrate relative to the cooling housing can be effectively prevented.

[0067] In the semiconductor device according to the above embodiment, the cooling housing includes a plurality of side walls defining the recess, and a pair of first and second side walls provided along the longitudinal direction of the assembly of the fins among the plurality of side walls are provided with an inlet and an outlet for a cooling medium, the inlet and the outlet for the cooling medium being provided at positions offset in opposite directions from a center line in the longitudinal direction of the recess, and the pair of engaging pieces are respectively engaged with corners of the recess that are continuous with the first and second side walls and are arranged at positions away from the inlet or the outlet. According to this structure, since the pair of engaging pieces are respectively engaged with corners of the recess that are continuous with the first and second side walls and are arranged at positions away from the inlet or the outlet, the heat dissipation substrate can be positioned relative to the cooling housing without reducing the flow rate of the cooling medium introduced from the inlet or discharged from the outlet.

[0068] In the semiconductor device involved in the above-mentioned embodiment, the pair of engaging pieces have an outer shape corresponding to the shape of the corners arranged diagonally in the recess. According to this structure, since positioning is performed using the pair of engaging pieces whose cross-sectional shapes correspond to the shape of the corners arranged diagonally in the recess, the heat dissipation substrate can be reliably positioned relative to the cooling housing using the shape of the corners of the recess.

[0069] In the semiconductor device involved in the above-mentioned embodiment, the pair of engaging pieces have a square or right-angled triangle cross-sectional shape, and the right-angled portion engages with the corner portion continuous with the first side wall and the second side wall. According to this structure, since the right-angled portion of the pair of engaging pieces engages with the corner portion continuous with the first side wall and the second side wall, the heat dissipation substrate can be reliably positioned relative to the cooling housing.

[0070] In the semiconductor device involved in the above-mentioned embodiment, auxiliary engaging pieces that engage with a part of the inner wall surface of the recess are provided around the pair of engaging pieces. According to this structure, since auxiliary engaging pieces that engage with a part of the inner wall surface of the recess are provided around the pair of engaging pieces, not only a pair of engaging pieces but also a plurality of engaging pieces can be used to engage with the inner wall surface of the recess, so that the heat dissipation substrate can be positioned relative to the cooling housing while ensuring strength.

[0071] In the semiconductor device involved in the above-mentioned embodiment, the interval between the pair of engaging pieces and the auxiliary engaging piece is set to be narrower than the interval between the fins constituting the assembly of the fins. According to this structure, since the interval between the pair of engaging pieces and the auxiliary engaging piece is set to be narrower than the interval between the fins constituting the assembly of the fins, it is difficult for the cooling medium to enter the gap between the pair of engaging pieces and the auxiliary engaging piece, so that the influence of the pair of engaging pieces and the like on the flow rate of the cooling medium can be reduced.

[0072] In the semiconductor device involved in the above-mentioned embodiment, the plurality of engaging pieces are made of the same metal material as the heat dissipation substrate. According to this structure, since the plurality of engaging pieces are made of the same metal material as the heat dissipation substrate, the engaging pieces can be manufactured by the manufacturing process of the heat dissipation substrate, and therefore, there is no need to add a special process to form the engaging pieces. Therefore, there is no need to add a special manufacturing process, but the plurality of engaging pieces can be formed on the heat dissipation substrate by the existing manufacturing process.

[0073] In the semiconductor device involved in the above-mentioned embodiment, the heat dissipation substrate is fastened to the cooling housing by a fastening member in a state where the plurality of engaging pieces are partially engaged with the inner wall surface of the recess. According to this structure, since the heat dissipation substrate is fastened to the cooling housing in a state where the plurality of engaging pieces are partially engaged with the inner wall surface of the recess, the heat dissipation substrate can be fixed in a state where the heat dissipation substrate is positioned in the cooling housing, and deterioration of the cooling performance of the cooler and poor fastening caused by positional deviation of the heat dissipation substrate can be prevented.

[0074] Industrial Applicability

[0075] The semiconductor device of the present invention has the effect of being able to position the heat dissipation substrate with respect to the cooling case with high accuracy without requiring a complicated structure, and is suitable for semiconductor devices such as vehicle-mounted motor drive control inverters that require miniaturization and high output.

[0076] This application is based on Japanese Patent Application No. 2018-188532 filed on October 3, 2018. The entire contents are incorporated herein by reference.

Claims

1. A semiconductor device, comprising: a semiconductor element (12, 13) and a cooler (20) for cooling the semiconductor element; The cooler has: A cooling shell (23), comprising a pair of first side walls, a second side wall, a pair of third side walls, a fourth side wall, an inlet (233) provided on the first side wall, and an outlet (234) provided on the second side wall; A heat dissipation substrate (21) disposed between the semiconductor element and the cooling housing; as well as Metal protrusions (22, 221, 222) are provided on the lower surface of the heat dissipation substrate. The recess (24) as the portion for the cooling medium to flow from the inlet to the outlet and the metal protrusion received in the recess are both constructed to be substantially point-symmetrical and asymmetrical with respect to the center line (CL1, CL2) between the third side wall and the fourth side wall.

2. The semiconductor device according to claim 1, wherein The metal protrusion comprises: A plurality of first metal protrusions (22) serving as fins; and A plurality of second metal protrusions (221, 222) are provided at an outer side than the first metal protrusions and have an outer shape corresponding to at least a portion of the first side wall, the second side wall, the third side wall and the fourth side wall.

3. The semiconductor device according to claim 2, wherein: The plurality of second metal protrusions are arranged substantially point-symmetrically and asymmetrically with respect to a center line ( CL1 , CL2 ) between the third side wall and the fourth side wall.

4. The semiconductor device according to claim 2, wherein: The plurality of second metal protrusions have an outer shape corresponding to the third side wall or the fourth side wall.

5. The semiconductor device according to claim 2, wherein: The plurality of second metal protrusions are pins.

6. The semiconductor device according to claim 2, wherein: The first metal protrusion is a prismatic or cylindrical pin, or is in the shape of a blade.

7. The semiconductor device according to claim 2, wherein: The first metal protrusion and the second metal protrusion are made of the same metal material as the heat dissipation substrate.

8. The semiconductor device according to claim 2, wherein: The plurality of second metal protrusions are engaging pieces (221, 222) for positioning.

9. The semiconductor device according to claim 1, wherein: The semiconductor device includes a liquid leakage prevention member (235) mounted on the upper side of the cooling housing so as to surround the recessed portion when viewed from above.

10. The semiconductor device according to claim 1, wherein The semiconductor device includes a fastening member that fastens the heat dissipation substrate to an upper side of the cooling case.

11. The semiconductor device according to claim 3, wherein: The plurality of second metal protrusions are adjacently housed at opposite corners of the recess.

12. The semiconductor device according to claim 11, wherein The plurality of second metal protrusions include a reference engaging piece that contacts both the first side wall and the third side wall constituting the diagonal corner, or contacts both the second side wall and the fourth side wall constituting the diagonal corner.

13. The semiconductor device according to claim 2, wherein: The introduction port and the discharge port are provided at positions offset from the center line in opposite directions to each other.

14. The semiconductor device according to claim 2, wherein: The plurality of second metal protrusions are in contact with the first side wall, the second side wall, the third side wall, and the fourth side wall.

15. The semiconductor device according to claim 2, wherein: The cooling shell includes a bottom wall (231) and inclined surfaces (237, 238) arranged in front of the inlet or behind the outlet and continuous with the bottom wall (231).

16. The semiconductor device according to claim 15, wherein: The second metal protrusion overlaps with the inclined surface in a plan view.

17. The semiconductor device according to claim 15, wherein: The gaps between the plurality of second metal protrusions adjacent to each other in the front-rear direction, into which the cooling medium can flow, are narrower than the intervals between the first metal protrusions.

18. A semiconductor device, comprising: a semiconductor device (1) comprising semiconductor elements (12, 13) and a cooler (20) for cooling the semiconductor elements; The cooler has: A cooling shell (23), comprising a pair of first side walls, a second side wall and a pair of third side walls, a fourth side wall, an inlet (233) provided on the first side wall, an outlet (234) provided on the second side wall, a bottom wall (231), and inclined surfaces (237, 238) arranged in front of the inlet or behind the outlet and continuous with the bottom wall (231); a heat dissipation substrate (21) disposed between the semiconductor element and the cooling housing; and Metal protrusions (22, 221, 222) are provided on the lower surface of the heat dissipation substrate. The metal protrusion overlaps with the inclined surface in a plan view.

19. The semiconductor device according to claim 18, wherein: The metal protrusions include a plurality of first metal protrusions (22) serving as fins and a plurality of second metal protrusions disposed at outer sides of the first metal protrusions. The gaps between the plurality of second metal protrusions adjacent to each other in the front-rear direction, into which the cooling medium can flow, are narrower than the intervals between the first metal protrusions.

20. A semiconductor device, comprising: a semiconductor device (1) comprising semiconductor elements (12, 13) and a cooler (20) for cooling the semiconductor elements; The cooler has: A cooling shell (23), comprising a pair of first side walls, a second side wall, a pair of third side walls, a fourth side wall, an inlet (233) provided on the first side wall, and an outlet (234) provided on the second side wall; A heat dissipation substrate (21) disposed between the semiconductor element and the cooling housing; as well as Metal protrusions (22, 221, 222) are provided on the lower surface of the heat dissipation substrate. The metal protrusion comprises: A plurality of first metal protrusions (22) serving as fins; and A plurality of second metal protrusions are provided at an outer side than the first metal protrusions and have an outer shape corresponding to at least a portion of the first side wall, the second side wall, the third side wall, and the fourth side wall.

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