Cooling device

Abstract

To provide a cooling device capable of reducing an outer shape while maintaining close contact between a heating element and a cooler.SOLUTION: A cooling device includes two coolers arranged on both sides of a semiconductor module 100, and a pressurizing member 80 that is held by one of the two coolers and is elastically deformed by being supported by the other of the two coolers, and pressurizes the two coolers such that the two coolers approach each other.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a cooling device. [Background technology]

[0002] For example, the semiconductor unit described in Patent Document 1 includes a stacked cooler having a stack in which multiple cooling pipes are stacked with a gap between adjacent cooling pipes for arranging a semiconductor module, which is a heat generating body. The semiconductor unit is held in a state pressed in the stacking direction by an external force of a pressure member applied from the side opposite to the side in contact with the cooler support part, thereby increasing the adhesion between the cooling pipes of the stacked cooler and the semiconductor module. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-112177 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to increase the adhesion between the heat generating element placed between the stacked coolers and the coolers, if a member that presses the coolers against the heat generating element (e.g., a semiconductor module) is provided on the outside of the stacked coolers, the external dimensions of the cooling device will become larger. An object of the present invention is to provide a cooling device that can be made smaller in size while maintaining close contact between the heat generating element and the cooler. [Means for solving the problem]

[0005] The present invention, which was completed with this objective in mind, is a cooling device comprising two coolers arranged on either side of a heat generating element, and a pressure member that is held by one of the two coolers and supported by the other of the two coolers, thereby elastically deforming and applying pressure to the two coolers so that the two coolers approach each other. Here, the pressure member may be a rectangular flat plate, with a central portion in the longitudinal direction held by one of the coolers and both ends in the longitudinal direction supported by the other cooler. Furthermore, a plurality of the heat generating elements may be arranged between the two coolers in a direction in which the cooling liquid flows inside the coolers, and the pressurizing member may be provided between the plurality of the heat generating elements. Furthermore, the one cooler and the other cooler comprise a heat sink having a plate-shaped base and a plurality of fins protruding from the base, and a housing that accommodates the plurality of fins and forms a flow path for the coolant, the housing having an opening formed at the bottom or top, the base being positioned so that it closes the opening and the forming portion on which the plurality of fins are formed is exposed from the opening, the housing having an outer facing portion provided on the outer edge of the opening in the flow direction, facing the forming portion and joined to the forming portion, and a middle facing portion provided between both ends of the opening in the flow direction, facing the forming portion and joined to the forming portion, and the pressure member may be held by the middle facing portion of the one cooler and supported by the middle facing portion of the other cooler. [Effects of the Invention]

[0006] According to the present invention, the outer dimensions can be reduced while maintaining close contact between the heat generating element and the cooler. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating an example of the appearance of a cooling device according to a first embodiment. [Figure 2] FIG. 2 is an example of an exploded view of components constituting the cooling device. [Figure 3] FIG. 2 is an example of an exploded view of components constituting a first cooler. [Figure 4] FIG. 2 is a diagram showing an example of a cross section taken along line IV-IV in FIG. [Figure 5] 2 is a diagram showing an example of a cross section of the VV portion of FIG. 1. FIG. [Figure 6] 6 is a diagram showing an example of a cross section taken along the line VI-VI in FIG. 1. FIG. [Figure 7] FIG. 2 is a perspective view of a pressure member; [Figure 8] 10A to 10C are diagrams illustrating an example of a method for joining a heat sink and a cover. [Figure 9] 10A and 10B are diagrams showing an example of a method for joining the cover and the first connecting member. [Figure 10] 10 is an example of a perspective view of the second cooler before the pressurizing member is assembled to the second cooler, as viewed from below. FIG. [Figure 11] FIG. 10 is a diagram showing an example of a process for assembling a pressurizing member to a second cooler. [Figure 12] FIG. 2 is a diagram showing a state in which a semiconductor module is placed on a first cooler. [Figure 13] 1A is a diagram illustrating an example of a process for assembling a second cooler and a pressure member to a first cooler, and FIGS. 1B and 1C are diagrams illustrating an example of a process for assembling a pressure member to a first cooler. [Figure 14] 1A and 1B are diagrams illustrating the gap between a cooling device and a terminal of a semiconductor module according to a comparative example, where (a) shows a case where the size of the short side of the main body of the semiconductor module is smaller than the size of the central through-hole formed in the cover of the first cooler, and (b) shows a case where the size of the short side of the main body is larger than the size of the central through-hole formed in the cover. [Figure 15] FIG. 6 is a diagram illustrating an example of a cross section of a cooling device according to a second embodiment. [Figure 16] FIG. 10 is a diagram illustrating an example of a cross section of a cooling device according to a third embodiment. [Figure 17] FIG. 10 is a diagram illustrating an example of a cross section of a cooling device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. First Embodiment FIG. 1 is a diagram showing an example of the appearance of a cooling device 1 according to the first embodiment. FIG. 2 is an example of an exploded view of components constituting the cooling device 1. As shown in FIG. Fig. 3 is an example of an exploded view of components constituting the first cooler 10. Note that Fig. 2 and Fig. 3 show a state in which a pressurizing member 80, which will be described later, is not yet assembled to the first cooler 10. 4, 5, and 6 are diagrams showing an example of a cross section of the cooling device 1. Fig. 4 is a diagram showing an example of a cross section taken along line IV-IV in Fig. 1. Fig. 5 is a diagram showing an example of a cross section taken along line VV in Fig. 1. Fig. 6 is a diagram showing an example of a cross section taken along line VI-VI in Fig. 1.

[0009] The cooling device 1 according to the first embodiment includes a first cooler 10 and a second cooler 20, which are coolers capable of circulating a coolant therethrough. The cooling device 1 also includes a first connecting member 40 fixed to the first cooler 10 to connect the first cooler 10 and the second cooler 20, and a second connecting member 50 fixed to the second cooler 20 to connect the first cooler 10 and the second cooler 20. The cooling device 1 also includes a support member 60 that supports the first cooler 10 and the second cooler 20, and a fastening member 70, such as a bolt, that fastens the first cooler 10 and the second cooler 20 to the support member 60. The cooling device 1 also includes a pressurizing member 80 that pressurizes the first cooler 10 and the second cooler 20 so that the first cooler 10 and the second cooler 20 approach each other. Hereinafter, the direction in which the first cooler 10 and the second cooler 20 are stacked may be referred to as the "vertical direction." Furthermore, in the rectangular parallelepiped first cooler 10 and second cooler 20, the longitudinal direction of the rectangle perpendicular to the vertical direction may be referred to as the "longitudinal direction," and the lateral direction of the rectangle may be referred to as the "lateral direction."

[0010] (1st cooler 10) The first cooler 10 includes a heat sink 11 having fins 112, a case 12 that houses the fins 112 of the heat sink 11, and a cover 13 that covers the opening of the case 12. The case 12 and the cover 13 function as a housing 15 that houses the fins 112 and forms a space S1 through which the coolant flows.

[0011] The heat sink 11 has a plate-shaped base 111 and a plurality of fins 112 protruding from the base 111 in a direction perpendicular to the plate surface (vertical direction). The fins 112 may be, for example, flat, as shown in Fig. 3. If they are flat, they may be parallel to the longitudinal direction, or may be wavy with portions inclined in the longitudinal direction. Alternatively, the fins 112 may be, for example, columnar, with the direction of protrusion from the base 111 being the columnar direction. The shape of the fins 112 cut along a plane perpendicular to the protruding direction may be, for example, a quadrangle such as a square, rectangle, or rhombus, a circle, or an ellipse.

[0012] The multiple fins 112 are formed in the center of the base 111 in the lateral direction. Hereinafter, the region of the base 111 where the multiple fins 112 are formed may be referred to as the forming portion 111a, and the region outside the forming portion 111a may be referred to as the outer portion 111b. The outer portion 111b has an inclined portion 111c that is inclined with respect to the forming portion 111a. The inclined portion 111c is provided over the entire longitudinal area, and its end in the lateral direction is located on the side where the fins 112 are provided (lower) than the forming portion 111a. As a result, the surface of the base 111 opposite the direction from which the multiple fins 112 protrude has an orthogonal surface 111d that is provided in the center in the lateral direction and is perpendicular to the up-down direction, and an inclined surface 111e that is provided outside the orthogonal surface 111d and is inclined to the orthogonal surface 111d.

[0013] The heat sink 11 configured as described above can be formed by extrusion, forging, cutting, etc. The heat sink 11 is formed from at least one of copper and aluminum. The aluminum material can be, for example, A1000 series pure aluminum such as A1100, or A6000 series aluminum alloy such as A6063. The heat sink 11 has an orthogonal surface 111d of the base 111 opposed to a heat spreader (not shown) of the main body 101 of the semiconductor module 100, which will be described later, via thermally conductive grease.

[0014] Case 12 is concave and has a flat bottom 121, side portions 122 extending from the outer periphery of bottom 121 in a direction perpendicular to bottom 121, and flanges 123 protruding outward from the tips of side portions 122 in a direction parallel to bottom 121. Bottom 121 and side portions 122 form a recess, and flanges 123 are formed around this recess.

[0015] The bottom portion 121 has a first circular through-hole 125 formed at one end in the longitudinal direction, and a second circular through-hole 126 formed at the other end in the longitudinal direction. The case 12 may be made of aluminum, for example.

[0016] Cover 13 is a plate-shaped member, and has an outer peripheral portion 131 provided on the outer periphery, and a central portion 132 provided in the center and protruding beyond outer peripheral portion 131 toward the opposite side of case 12 . The outer shape of outer periphery 131 is substantially the same as the outer periphery of flange 123 of case 12. Outer periphery 131 is a portion perpendicular to the up-down direction, and has a circular first through-hole 135 formed at one end in the longitudinal direction and a circular second through-hole 136 formed at the other end in the longitudinal direction.

[0017] The central portion 132 has a top portion 141 and side portions 142 extending from the outer periphery of the top portion 141 toward the outer periphery 131 . The top portion 141 is a portion that is perpendicular to the up-down direction. The side portion 142 has short side portions 143 provided at both ends in the short direction and long side portions 144 provided at both ends in the long direction. The short side portions 143 and the long side portions 144 are inclined with respect to the top portion 141. However, the long side portions 144 may be parallel to the up-down direction, in other words, perpendicular to the top portion 141.

[0018] The central portion 132 is formed with central through-holes 145, the number of which is the same as the number of semiconductor modules 100 (three in FIG. 1). The central through-holes 145 are aligned in the longitudinal direction. The central through-hole 145 has a rectangular shape when viewed in the vertical direction, and is composed of the entire area of ​​the top 141 and portions of the short side portions 143 on both sides of the top 141 that are closer to the top 141. Edge portions 143a of the short side portions 143 that are on the edge of the central through-hole 145 are located below the orthogonal surface 111d of the heat sink 11.

[0019] Since multiple central through holes 145 are formed in the central portion 132, the top portion 141 has an outer facing portion 141a that is provided on the outer longitudinal edge of the multiple central through holes 145 and faces the forming portion 111a of the heat sink 11, and a middle facing portion 141b that is provided between adjacent central through holes 145 and faces the forming portion 111a.

[0020] The middle opposing portion 141b has two support portions 141c that support both ends in the short side direction of the pressure applying member 80. As shown in Fig. 3, the support portions 141c are parallel to the vertical direction before the pressure applying member 80 is assembled, and when the pressure applying member 80 is assembled, as shown in Fig. 6, the support portions 141c are bent so as to be perpendicular to the vertical direction, thereby suppressing movement of the pressure applying member 80.

[0021] In the first cooler 10 configured as described above, the short side portions 143 provided at both ends in the short direction of the central portion 132 of the cover 13 are joined to the outer portions 111b provided at both ends in the short direction of the base 111 of the heat sink 11. Also, the top portion 141 of the central portion 132 of the cover 13 is joined to the forming portion 111a of the base 111 of the heat sink 11. For example, the cover 13 and the heat sink 11 may be joined by laser welding. However, the cover 13 and the heat sink 11 may also be joined by brazing.

[0022] The case 12 and the cover 13 are joined together by laser welding, for example. However, the case 12 and the cover 13 may also be joined together by brazing.

[0023] (Second cooler 20) The second cooler 20 includes a heat sink 21 similar to the heat sink 11. The second cooler 20 also includes a case 22 corresponding to the case 12 and a cover 23 corresponding to the cover 13.

[0024] The heat sink 21 has a base portion 211 corresponding to the base portion 111 and the plurality of fins 112 of the heat sink 11, and a plurality of fins 212. The heat sink 21 also has a forming portion 211a and an outer portion 211b corresponding to the forming portion 111a and the outer portion 111b of the heat sink 11, respectively.

[0025] The case 22 differs from the case 12 in that the first through-hole 125 and the second through-hole 126 are not formed. The cover 23 differs from the cover 13 in that it does not have the support portion 141c but has a holding portion 241c that holds the pressure member 80. More specifically, the cover 23 has an outer periphery 231 and a central portion 232 that correspond to the outer periphery 131 and central portion 132 of the cover 13, respectively.

[0026] The outer circumferential portion 231 has a first circular through-hole 235 formed at one end in the longitudinal direction, and a second circular through-hole 236 formed at the other end in the longitudinal direction. The central portion 232 has a top portion 241 and side portions 242 that correspond to the top portion 141 and side portions 142 of the cover 13, respectively. The side portion 242 has short side portions 243 and long side portions 244 that correspond to the short side portions 143 and long side portions 144 of the cover 13, respectively.

[0027] In the central portion 232, central through-holes 245 corresponding to the central through-holes 145 of the cover 13 are formed in the same number as the number of semiconductor modules 100 (three in FIG. 1 ). The multiple central through-holes 245 are aligned in the longitudinal direction. Because the multiple central through-holes 245 are formed in the central portion 232, the top portion 241 has outer facing portions 241a that are provided on the outer edges of the multiple central through-holes 245 in the longitudinal direction and face the forming portions 211a of the heat sink 21, and middle facing portions 241b that are provided between adjacent central through-holes 245 and face the forming portions 211a.

[0028] The middle opposing portion 241b has a holding portion 241c that holds the pressure member 80. As shown in Fig. 10, the holding portion 241c is parallel to the vertical direction before the pressure member 80 is assembled, and is bent so as to be perpendicular to the vertical direction when the pressure member 80 is assembled, thereby suppressing movement of the pressure member 80. The holding portion 241c will be described in detail later.

[0029] The case 22 and the cover 23 function as a housing 25 that houses the fins 212 of the heat sink 21 and forms a space S2 through which the coolant flows. The second cooler 20 is disposed symmetrically to the first cooler 10 with respect to a plane perpendicular to the up-down direction. In the example shown in FIGS. 1 and 4, the cover 23 is on the lower side and the case 22 is on the upper side, and the cover 23 is disposed at the bottom of the housing 25 and the case 22 is disposed at the top of the housing 25.

[0030] (First connecting member 40) The first connecting member 40 is an elliptical cylindrical member whose minor axis corresponds to the longitudinal direction of the first cooler 10 and whose major axis corresponds to the lateral direction of the first cooler 10. A circular first through-hole 41 is formed in the center of the first connecting member 40. The first through-hole 41 has the same shape as the first through-hole 135 and the second through-hole 136 of the cover 13 of the first cooler 10. A groove 42 into which an O-ring 45 is fitted is formed around the first through-hole 41 on the upper surface of the first connecting member 40. The first connecting member 40 has cylindrical protrusions 43 protruding from one surface on both sides of the groove 42 in the major axis direction. A cylindrical second through-hole 44 is formed in the center of the protrusion 43. The material of the first connecting member 40 can be, for example, aluminum.

[0031] (Second connecting member 50) The second connecting member 50 is an elliptical cylindrical member whose minor axis direction is the longitudinal direction of the second cooler 20 and whose major axis direction is the lateral direction of the second cooler 20. A circular first through hole 54 is formed in the center of the second connecting member 50. The first through hole 54 has the same shape as the first through hole 135 and the second through hole 136 of the cover 13 of the first cooler 10. In addition, the second connecting member 50 has second through holes 55 formed on both sides of the first through hole 54 in the major axis direction. The material of the second connecting member 50 can be, for example, aluminum.

[0032] (support member 60) The support member 60 has a first space 61 recessed from the top surface at one end in the longitudinal direction and a second space 62 recessed from the top surface at the other end in the longitudinal direction. An opening 61a on the top surface of the first space 61 has the same shape as the first through hole 41 of the first connecting member 40. An opening 62a on the top surface of the second space 62 has the same shape as the first through hole 41 of the first connecting member 40. A groove 61b into which an O-ring 65 is fitted is formed around the opening 61a of the support member 60. A groove 62b into which an O-ring 66 is fitted is formed around the opening 62a of the support member 60. Furthermore, the support member 60 has female threads 61c formed on both outer sides of the groove 61b in the longitudinal direction. Furthermore, the support member 60 has female threads 62c formed on both outer sides of the groove 62b in the longitudinal direction.

[0033] A communication hole is formed in the support member 60, connecting the first space 61 with the outside in a direction perpendicular to the up-down direction (the short direction in FIG. 1), and a first joint 63 is fitted into this communication hole. Further, a communication hole is formed in the support member 60, connecting the second space 62 with the outside in a direction perpendicular to the up-down direction, and a second joint 64 is fitted into this communication hole. The material of the support member 60 can be, for example, aluminum.

[0034] With the first connecting member 40 and the second connecting member 50 stacked in the vertical direction, the first cooler 10 and the second cooler 20 are fastened to the support member 60 by fastening members 70 such as bolts. A semiconductor module 100 having a power semiconductor element is sandwiched between the first cooler 10 and the second cooler 20. In this embodiment, three semiconductor modules 100 are sandwiched. Heat conduction from the semiconductor module 100 to the heat sink 11 and the heat sink 21 is promoted by interposing thermally conductive grease between the semiconductor module 100, which is an example of a heat generating body, and the heat sink 11, and between the semiconductor module 100 and the heat sink 21.

[0035] The semiconductor module 100 has a main body 101 having a power semiconductor element, a plurality of terminals 102 (three in FIG. 1) to which bus bars, which are conductors for conducting current to be supplied to a motor, are connected, and a plurality of control terminals 103 provided for controlling the power semiconductor element, etc.

[0036] FIG. 7 is an example of a perspective view of the pressure member 80. As shown in FIG. The pressure applying member 80 is a rectangular, flat member before being assembled to the first cooler 10 and the second cooler 20, and is arranged so that when viewed from the top to bottom, the long side is the long direction of the first cooler 10 and the short side is the long side. The pressurizing member 80 has a central portion in the short side direction held by the holding portion 241c of the cover 23 of the second cooler 20, and both end portions in the short side direction supported by the support portions 141c of the cover 13 of the first cooler 10. With both end portions in the short side supported by the support portions 141c of the cover 13 of the first cooler 10, the pressurizing member 80 is elastically deformed into a convex shape with the central portion in the short side facing the second cooler 20 (upper side) and both end portions in the short side facing the first cooler 10 (lower side). As a result, due to elastic forces generated at both end portions in the short side direction of the pressurizing member 80, the first cooler 10 is subjected to a force that moves it toward the second cooler 20, and the second cooler 20 is subjected to a force that moves it toward the first cooler 10. In other words, the first cooler 10 and the second cooler 20 are subjected to forces that move them toward each other. In other words, the first cooler 10 and the second cooler 20 receive a force from the pressure member 80 pressing against the main body 101 of the semiconductor module 100. This increases the adhesion between the first cooler 10 and the second cooler 20 and the main body 101 of the semiconductor module 100. As a result, heat conduction from the main body 101 of the semiconductor module 100 to the heat sink 11 and the heat sink 21 is promoted.

[0037] It should be noted that the shape of the pressure applying member 80 is not limited to a flat plate. For example, both ends of the pressure applying member 80 in the short side direction may be bent relative to the center so as to be perpendicular to the up-down direction in a state where the pressure applying member 80 is assembled to the first cooler 10 and the second cooler 20, in other words, in a state where the pressure applying member 80 is elastically deformed in a convex shape.

[0038] (Manufacturing method of cooling device 1) The cooling device 1 configured as above is manufactured as follows. FIG. 8 is a diagram showing an example of a method for joining the heat sink 11 and the cover 13. As shown in FIG. The heat sink 11 and the cover 13 are joined by laser welding. When laser welding, the cover 13 is placed on the base 111 of the heat sink 11. More specifically, the short side portions 143 of the central portion 132 of the cover 13 are placed on the inclined surface 111e of the outer portion 111b of the heat sink 11, and the top portion 141 of the central portion 132 of the cover 13 is placed on the orthogonal surface 111d of the heat sink 11. Then, laser light L is irradiated from the laser head 151 of the laser device 150 toward the cover 13 at the overlapping portion of the heat sink 11 and the cover 13. The laser head 151 is moved along the shape of the short side portions 143 of the side portions 142 of the central portion 132 of the cover 13, so that the laser light L is continuously irradiated onto the short side portions 143 of the cover 13. Furthermore, the laser head 151 irradiates the laser beam L toward the outer facing portion 141a at one end in the longitudinal direction of the top portion 141 of the central portion 132 of the cover 13, and the laser head 151 is moved in the lateral direction to continuously irradiate the outer facing portion 141a with the laser beam L. Similarly, the laser head 151 irradiates the outer facing portion 141a at the other end in the longitudinal direction of the top portion 141 of the cover 13 with the laser beam L. The laser head 151 irradiates the laser beam L toward the middle facing portion 141b between adjacent central through-holes 145 of the top portion 141 of the central portion 132 of the cover 13, and the laser head 151 is moved in the lateral direction to continuously irradiate the middle facing portion 141b with the laser beam L. In this case, the irradiation positions in the longitudinal direction are on both sides of the support portion 141c.

[0039] FIG. 9 is a diagram showing an example of a method for joining the cover 13 and the first connecting member 40. As shown in FIG. The cover 13 and the first connecting member 40 provided at one end in the longitudinal direction are joined by laser welding. More specifically, the cover 13 is placed on the first connecting member 40 so that the first through hole 135 of the cover 13 and the first through hole 41 of the first connecting member 40 face each other. Then, laser light L is irradiated from the laser head 151 of the laser device 150 toward the cover 13 at the overlapping portion of the cover 13 and the first connecting member 40, and the laser head 151 is moved along the shape of the periphery of the first through hole 135, thereby continuously irradiating the periphery of the first through hole 135 with the laser light L. In a similar manner, the cover 13 and the first connecting member 40 provided at the other end in the longitudinal direction are joined by laser welding.

[0040] Thereafter, the case 12 is joined to the integrated assembly of the heat sink 11, the cover 13, and the first connecting member 40. An example of the joining method is laser welding. That is, the outer periphery 131 of the cover 13 and the flange 123 of the case 12 are joined by laser welding. When joining by laser welding, the case 12 is placed on the cover 13, and laser light L is irradiated from the laser head 151 of the laser device 150 toward the case 12 at the overlapping portion of the cover 13 and the case 12. The laser head 151 is then moved along the shape of the flange 123 of the case 12 to continuously irradiate the laser light L. Note that the method of joining the case 12 to the integrated assembly of the heat sink 11, the cover 13, and the first connecting member 40 may also be brazing. In this manner, the first cooler 10 is manufactured.

[0041] Before the pressure member 80 is attached to the first cooler 10, the support portion 141c of the cover 13 is provided to extend in a direction intersecting the forming portion 111a of the heat sink 11. For example, as shown in Fig. 3, the support portion 141c is provided to extend parallel to the vertical direction.

[0042] The second cooler 20 is manufactured in the same manner as the first cooler 10 described above. More specifically, the heat sink 21 and the cover 23 are joined by laser welding. The method for joining the heat sink 21 and the cover 23 is the same as the method for joining the heat sink 11 and the cover 13. However, when the laser head 151 irradiates the middle facing portion 241b between adjacent central through-holes 245 in the top portion 241 of the central portion 232 of the cover 23 with laser light L, in the region outside the holding portion 241c in the short direction, both ends in the longitudinal direction of the middle facing portion 241b are irradiated, and in the region where the holding portion 241c is formed, the inside of the holding portion 241c is irradiated (see FIG. 10). Furthermore, the laser head 151 is moved in the longitudinal direction from the irradiation position of the end portion in the longitudinal direction of the middle facing portion 241b so as to connect the irradiation position of the end portion in the longitudinal direction of the middle facing portion 241b and the irradiation position inside the holding portion 241c, and the laser light L is continuously irradiated (see FIG. 10).

[0043] Furthermore, the cover 23 and the second connecting member 50 are joined together using a method similar to the method used to join the cover 13 and the first connecting member 40 together. Thereafter, the case 22 is joined to the integrated assembly of the heat sink 21, the cover 23, and the second connecting member 50. The joining method is the same as the method for joining the case 12 to the integrated assembly of the heat sink 11, the cover 13, and the first connecting member 40.

[0044] FIG. 10 is an example of a perspective view of the second cooler 20 seen from below before the pressurizing member 80 is assembled to the second cooler 20. As shown in FIG. Before the pressure member 80 is attached to the second cooler 20, the holding portions 241c of the cover 23 are provided so as to extend in a direction intersecting the forming portion 211a of the heat sink 21. For example, as shown in Fig. 10, the holding portions 241c are provided so as to extend parallel to the vertical direction and the short-side direction. In the example shown in Fig. 10, two holding portions 241c are provided at each end of the middle opposing portion 241b in the longitudinal direction.

[0045] FIG. 11 is a diagram showing an example of a process for assembling the pressurizing member 80 to the second cooler 20. As shown in FIG. After manufacturing the second cooler 20, the pressure member 80 is assembled to the second cooler 20. First, as shown in FIG. 11(a), the pressure member 80 is disposed between the two holding portions 241c of the cover 23 so as to face the middle facing portion 241b. Then, as shown in FIG. 11(b), a jig 600 is used to bend and plastically deform the two holding portions 241c to a position where the holding portions 241c and the pressure member 80 overlap in the vertical direction. For example, each of the two holding portions 241c is bent 90 degrees toward the pressure member 80. As a result, the pressure member 80 is held by the two holding portions 241c. In addition, instead of assembling the pressure member 80 after manufacturing the second cooler 20, the pressure member 80 may be assembled to an integrated unit of the heat sink 21, the cover 23, and the second connecting member 50, and then the case 22 may be joined.

[0046] FIG. 12 is a diagram showing a state in which the semiconductor module 100 is placed on the first cooler 10. As shown in FIG. 12, an integrated unit of the first cooler 10 and the first connecting member 40 is placed on the support member 60, and the semiconductor modules 100 are placed on the first cooler 10. When placing the semiconductor modules 100 on the first cooler 10, the main bodies 101 of the three semiconductor modules 100 are placed on the orthogonal surfaces 111d of the heat sink 11 exposed from the central through-hole 145 formed in the cover 13 of the first cooler 10. When placing the main bodies 101, thermally conductive grease is applied to the orthogonal surfaces 111d of the heat sink 11 of the first cooler 10 or to the surface of the main bodies 101, and then the main bodies 101 are placed on the orthogonal surfaces 111d.

[0047] FIG. 13(a) is a diagram showing an example of a process for assembling the second cooler 20 and the pressurizing member 80 to the first cooler 10. As shown in FIG. After placing the semiconductor module 100 on the first cooler 10, the second connecting member 50 fixed to the second cooler 20 is placed on the first connecting member 40 fixed to the first cooler 10 in order to assemble the second cooler 20 and the pressure member 80 to the first cooler 10. When placing the second connecting member 50 on the first connecting member 40, the second cooler 20 is placed on the main body 101 of the semiconductor module 100, as shown in FIG. 13(a). When placing the second cooler 20 on the semiconductor module 100, thermally conductive grease is applied to the surface of the heat sink 21 of the second cooler 20 or the main body 101 of the semiconductor module 100.

[0048] 13(b) and 13(c) are diagrams showing an example of a process for assembling the pressurizing member 80 to the first cooler 10. FIG. When placing the second cooler 20 on the semiconductor module 100, or after placing the second cooler 20 on the semiconductor module 100, as shown in Figure 13(b), one end of the pressure member 80 in the short direction, which is fixed to the second cooler 20, is bent toward the first cooler 10 using a first jig 610 to elastically deform it, and the other end of the pressure member 80 in the short direction is bent toward the first cooler 10 using a second jig 620 to elastically deform it. 13(c), the support portion 141c of the first cooler 10 at one end in the short side direction is bent and plastically deformed using a third jig 630 to a position where the support portion 141c and the pressing member 80 overlap in the vertical direction, and the support portion 141c of the first cooler 10 at the other end in the short side direction is bent and plastically deformed using a fourth jig 640 to a position where the support portion 141c and the pressing member 80 overlap in the vertical direction. The end of the pressing member 80 is supported by the support portion 141c of the first cooler 10, and the pressing member 80 is prevented from returning to its original state after elastic deformation. In this way, the pressing member 80 held by the second cooler 20 is assembled to the first cooler 10.

[0049] The first jig 610 and the third jig 630 may be integrally configured. Similarly, the second jig 620 and the fourth jig 640 may be integrally configured. The step of assembling one end of the pressure member 80 in the short side direction to the first cooler 10 and the step of assembling the other end of the pressure member 80 in the short side direction to the first cooler 10 may be performed simultaneously or separately. For example, the step of assembling one end of the pressure member 80 in the short side direction to the first cooler 10 may be performed after the step of assembling the other end of the pressure member 80 in the short side direction to the first cooler 10. In such a case, the first jig 610 and the third jig 630 may be the same as the second jig 620 and the fourth jig 640, respectively.

[0050] Thereafter, the first cooler 10 and the second cooler 20 are fixed to the support member 60. More specifically, the male screw of the fastening member 70, whose shank is passed through the second through-hole 55 of the second connecting member 50 arranged at one end in the longitudinal direction and the second through-hole 44 of the first connecting member 40, is fastened to the female screw 61c of the support member 60, and the male screw of the fastening member 70, whose shank is passed through the second through-hole 55 of the second connecting member 50 arranged at the other end in the longitudinal direction and the second through-hole 44 of the first connecting member 40, is fastened to the female screw 62c of the support member 60.

[0051] (Function of cooling device 1) In the cooling device 1 manufactured as described above, the coolant that has flowed into the first space 61 from the first joint 63 of the support member 60 passes through the opening 61a and the first through-hole 125 formed at one end in the longitudinal direction of the case 12 of the first cooler 10, and then flows into the space S1 formed inside the first cooler 10. The coolant that has flowed into the inside of the first cooler 10 then advances in the longitudinal direction through flow paths formed between the multiple fins 112 of the heat sink 11 and between the fins 112 and the side portion 122 of the case 12, and flows out of the first cooler 10 through the second through-hole 126 formed at the other end in the longitudinal direction of the case 12. In the first cooler 10, the coolant flows from the first through-hole 125 to the second through-hole 126, so the longitudinal direction is the flow direction of the coolant.

[0052] A part of the coolant that has flowed into the first cooler 10 through the first through-hole 125 flows out of the first cooler 10 through the first through-hole 135 of the cover 13, and then flows into the space S2 formed inside the second cooler 20 through the inside of the first connecting member 40 and the second connecting member 50 and the first through-hole 235 formed at one end in the longitudinal direction of the cover 23 of the second cooler 20. The coolant that has flowed into the second cooler 20 then advances in the longitudinal direction through flow paths formed between the multiple fins 212 of the heat sink 21 and between the fins 212 and the side of the case 22, and flows out of the second cooler 20 through the second through-hole 236 formed at the other end in the longitudinal direction of the cover 23. Note that in the second cooler 20 as well, the longitudinal direction is the flow direction of the coolant.

[0053] The cooling liquid that flows out of the second cooler 20 flows into the inside of the first cooler 10 through the inside of the first connecting member 40 and the second connecting member 50 and the second through hole 136 of the cover 13 of the first cooler 10, and flows out of the first cooler 10 through the second through hole 126 formed at the other longitudinal end of the case 12. The coolant that has flowed out of the first cooler 10 enters the second space 62 through the opening 62 a formed in the support member 60 and flows out from the second joint 64 .

[0054] In this way, while the coolant flows through the inside of the first cooler 10 and the inside of the second cooler 20, the semiconductor module 100 arranged between the first cooler 10 and the second cooler 20 is cooled.

[0055] Here, the cooling device 1 includes a heat sink 11 having a plate-shaped base 111 and a plurality of fins 112 protruding from the base 111, and a housing 15 that houses the plurality of fins 112 and forms a flow path for the coolant. The housing 15 has a central through-hole 145 as an example of an opening in a cover 13. The base 111 of the heat sink 11 closes the central through-hole 145 and is disposed so that a forming portion 111a on which the plurality of fins 112 are formed is exposed from the central through-hole 145, and the forming portion 111a protrudes in the opposite direction to the flow path beyond an outer portion 111b that is located outside the forming portion 111a.

[0056] In the cooling device 1 configured as described above, the forming portion 111a of the heat sink 11 is arranged so as to be exposed from the central through-hole 145, and the forming portion 111a protrudes further in the opposite direction from the flow path than the outer portion 111b. Therefore, by placing the main body 101 of the semiconductor module 100 on the orthogonal surface 111d of this forming portion 111a, the semiconductor module 100 can also protrude in the opposite direction from the flow path. In other words, the vertical position of the forming portion 111a of the heat sink 11 can be made to protrude toward the second cooler 20 with respect to the outer periphery 131 of the cover 13 of the first cooler 10. This makes it possible to increase the vertical gap G (see FIG. 4) between the terminals 102 of the semiconductor module 100 and the outer periphery 131 of the cover 13 of the first cooler 10.

[0057] 14A and 14B are diagrams showing the gap Gc between the cooling device 5 according to the comparative example and the terminal 102 of the semiconductor module 100. Fig. 14A shows a case where the size in the short side direction of the main body 101 of the semiconductor module 100 is smaller than the size of the central through-hole 545 formed in the cover 53 of the first cooler 510, and Fig. 14B shows a case where the size in the short side direction of the main body 101 is larger than the size of the central through-hole 545 formed in the cover 53. 14(a), consider a cooling device 5 according to Comparative Example 1, in which the base 511 of the heat sink 51 is flat and the central through-hole 545 formed in the cover 53 is blocked. When the semiconductor module 100 is placed opposite the base 511 of the heat sink 51 of the cooling device 5 according to Comparative Example with thermally conductive grease interposed therebetween, the gap Gc between the cover 53 and the terminals 102 of the semiconductor module 100 becomes smaller than the gap G in the cooling device 1 shown in FIG. 4. In other words, according to the cooling device 1, the gap G between the terminals 102 of the semiconductor module 100 and the outer periphery 131 of the cover 13 can be made larger than the gap Gc between the cover 53 and the terminals 102 of the semiconductor module 100 in the cooling device 5 according to Comparative Example.

[0058] 14(b), in the cooling device 5 according to Comparative Example 2, if the outer shape of the main body 101 of the semiconductor module 100 is larger than the shape of the central through-hole 545 formed in the cover 53, the main body 101 of the semiconductor module 100 cannot be placed in the central through-hole 545, and the main body 101 of the semiconductor module 100 and the cover 53 come into contact with each other. Therefore, the distance between the main body 101 of the semiconductor module 100 and the heat sink 51 is greater by the thickness of the cover 53 than the distance shown in FIG. 4. As a result, more thermally conductive grease is required to maintain heat conduction from the semiconductor module 100 to the heat sink 51.

[0059] In contrast, in the cooling device 1 according to this embodiment, the orthogonal surface 111d of the heat sink 11 protrudes in the direction opposite to the flow path beyond the edge 143a of the central through-hole 145 in the short side portion 143, so that even if the outer shape of the main body 101 of the semiconductor module 100 is larger than the shape of the orthogonal surface 111d, it is possible to reduce the distance between the main body 101 of the semiconductor module 100 and the orthogonal surface 111d of the heat sink 11. As a result, even with less thermally conductive grease than in the cooling device 5 according to Comparative Example 2, heat can be conducted from the semiconductor module 100 to the heat sink 11.

[0060] The base 111 of the heat sink 11 has an inclined portion 111c that is provided outside the forming portion 111a and inclined toward the side where the multiple fins 112 are provided, and the cover 13 has a short side portion 143 as an example of an inclined opposing portion that faces the inclined portion 111c and is joined to the inclined portion 111c outside the central through-hole 145. As a result, the heat sink 11 is joined at a portion close to the multiple fins 112, so the size in the short direction can be reduced.

[0061] The inclined portion 111c of the heat sink 11 is formed parallel to the flow direction of the coolant, and the cover 13 has an outer facing portion 141a that faces the forming portion 111a of the heat sink 11 and is joined to the forming portion 111a at the outer edge of the central through-hole 145 in the flow direction. This makes it easy to position the heat sink 11 in the first cooler 10.

[0062] Furthermore, the cover 13 has a plurality of (for example, three) central through holes 145 formed in the flow direction, and has middle opposing portions 141b that are opposed to and joined to the forming portions 111a between the plurality of central through holes 145. This makes it easy to position the heat sink 11 in the first cooler 10.

[0063] The cooling device 1 also includes a first cooler 10 and a second cooler 20 as examples of two coolers arranged on both sides of the semiconductor module 100, and a pressure member 80 held by the second cooler 20 as an example of one of the first cooler 10 and the second cooler 20 and supported by the first cooler 10 as an example of the other cooler. The pressure member 80 is held by the second cooler 20 and supported by the first cooler 10, causing it to elastically deform and pressurize the first cooler 10 and the second cooler 20 so that the first cooler 10 and the second cooler 20 approach each other. This improves the adhesion between the semiconductor module 100 and the first cooler 10, and also improves the adhesion between the semiconductor module 100 and the second cooler 20. The pressure member 80 is arranged between the first cooler 10 and the second cooler 20, and is not provided outside the first cooler 10 or the second cooler 20. As a result, the cooling device 1 has a smaller outer shape compared to a configuration in which, for example, a member is provided on the outside of the first cooler 10 and the second cooler 20 to pressurize the first cooler 10 and the second cooler 20 to increase adhesion with the semiconductor module 100.

[0064] The pressure member 80 is rectangular and flat, and its central portion in the short side direction (longitudinal direction of the pressure member 80) is held by the second cooler 20, and both ends in the short side direction are supported by the first cooler 10. This allows the first cooler 10 to be pressurized evenly in the short side direction, and the adhesion between the first cooler 10 and the second cooler 20 and the semiconductor module 100 can be improved evenly in the short side direction.

[0065] A plurality of (three in this embodiment) semiconductor modules 100 are arranged between the first cooler 10 and the second cooler 20 in the direction of flow of the coolant, and the pressure member 80 is provided between the plurality of semiconductor modules 100. This makes it possible to improve the adhesion between the first cooler 10 and the second cooler 20 and all of the semiconductor modules 100, even in the case of the cooling device 1 having the long first cooler 10 and the second cooler 20 in which the plurality of semiconductor modules 100 are arranged between the first cooler 10 and the second cooler 20.

[0066] In the above-described embodiment, the cooling device 1 may be provided with a pressure applying member 80 that is held on the inner opposing portion 241b of the cover 23 of the second cooler 20 and supported on the inner opposing portion 141b of the cover 13 of the first cooler 10, as well as a pressure applying member 80 that is held on the outer opposing portion 241a of the cover 23 of the second cooler 20 and supported on the outer opposing portion 141a of the cover 13 of the first cooler 10.

[0067] In the above-described embodiment, the central portion of the pressure applying member 80 in the short side direction (longitudinal direction of the pressure applying member 80) is held by the second cooler 20, and both ends in the short side direction are supported by the first cooler 10. However, this is not particularly limited to such an embodiment. For example, the pressure applying member 80 may be configured so that the central portion in the short side direction is held by the first cooler 10, and both ends in the short side direction are supported by the second cooler 20.

[0068] Furthermore, in the cooling device 1, the pressurizing member 80, which is held by the second cooler 20 and supported by the first cooler 10, is arranged so that the forming portion 111a of the heat sink 11 is exposed from the central through-hole 145, and the forming portion 111a protrudes further in the opposite direction from the flow path than the outer portion 111b, but this is not particularly limited to this configuration. For example, the pressurizing member 80 may be applied to a device in which the base portion 511 of the heat sink 51 is flat and blocks the central through-hole 545 formed in the cover 53, as in the cooling device 5 according to the comparative example. Furthermore, the pressurizing member 80 may be applied to a device in which no opening (e.g., the central through-hole 145) is formed in the housing (e.g., the housing 15) and the heat sink (e.g., the heat sink 11) is not exposed from the opening formed in the housing (e.g., the housing 15).

[0069] Second Embodiment FIG. 15 is a diagram showing an example of a cross section of the cooling device 2 according to the second embodiment. The cooling device 2 according to the second embodiment differs from the cooling device 1 according to the first embodiment in that it has a cover 213 corresponding to the cover 13 of the first cooler 10 and a cover 223 corresponding to the cover 23 of the second cooler 20. The following describes the differences from the first embodiment. The same components in the first and second embodiments are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0070] In the cover 213, an edge 243a at the edge of the central through-hole 145 in a short side portion 243 corresponding to the short side portion 143 is positioned closer to the semiconductor module 100 than the orthogonal surface 111d of the heat sink 11. The cover 223 of the second cooler 20 has the same shape as the cover 213.

[0071] In the cooling device 2 configured as described above, when the widthwise dimension of the main body 101 of the semiconductor module 100 is larger than the widthwise dimension of the central through-hole 145, the main body 101 comes into contact with the edge portion 243a of the cover 213. The gap thus created is filled with thermally conductive grease. The thermally conductive grease interposed between the main body 101 of the semiconductor module 100 and the orthogonal surface 111d of the heat sink 11 is prevented from moving in the widthwise direction by the short-side side portion 243 of the cover 213. Furthermore, the thermally conductive grease is prevented from moving in the longitudinal direction by the central opposing portion 141b of the cover 213. As a result, a decrease in heat dissipation performance is prevented, which would otherwise occur if the thermally conductive grease migrated from between the main body 101 of the semiconductor module 100 and the orthogonal surface 111d of the heat sink 11 to the outside of the main body 101, creating a gap between the main body 101 and the orthogonal surface 111d.

[0072] Third Embodiment FIG. 16 is a diagram showing an example of a cross section of the cooling device 3 according to the third embodiment. The cooling device 3 according to the third embodiment differs from the cooling device 1 according to the first embodiment in that it has a cover 313 corresponding to the cover 13 of the first cooler 10 and a cover 323 corresponding to the cover 23 of the second cooler 20. The following describes the differences from the first embodiment. The same components in the first and third embodiments are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0073] The cover 313 is different from the cover 13 in the longitudinal size of the central through-holes 145. In other words, the longitudinal size of the central through-holes 345 formed in the cover 313, the number of which is the same as the number of semiconductor modules 100, is the same as the longitudinal size of the main body 101 of the semiconductor module 100. Therefore, with the semiconductor module 100 placed on the heat sink 11, the longitudinal end face of the main body 101 comes into contact with the longitudinal end faces of the outer facing portion 341a and the middle facing portion 341b of the cover 313, as shown in FIG.

[0074] In the cooling device 3 configured as described above, the thermally conductive grease interposed between the main body 101 of the semiconductor module 100 and the orthogonal surface 111d of the heat sink 11 is prevented from moving in the longitudinal direction by the outer facing portion 341a and the middle facing portion 341b of the cover 313. As a result, a decrease in heat dissipation performance is prevented, which would otherwise occur if the thermally conductive grease moves from between the main body 101 of the semiconductor module 100 and the orthogonal surface 111d of the heat sink 11 to the outside of the main body 101, creating a gap between the main body 101 and the orthogonal surface 111d. The cover 323 of the second cooler 20 may also have the same shape as the cover 313 of the first cooler 10.

[0075] Furthermore, the cooling device 2 according to the second embodiment may also be configured so that the longitudinal end faces of the main body 101 of the semiconductor module 100 come into contact with the longitudinal end faces of the outer facing portion 141a and the middle facing portion 141b of the top portion 141. This prevents a decrease in heat dissipation performance.

[0076] <Fourth embodiment> FIG. 17 is a diagram showing an example of a cross section of the cooling device 4 according to the fourth embodiment. The cooling device 4 according to the fourth embodiment differs from the cooling device 1 according to the first embodiment in that it has a heat sink 411 corresponding to the heat sink 11 of the first cooler 10, a cover 413 corresponding to the cover 13, a heat sink 421 corresponding to the heat sink 21 of the second cooler 20, and a cover 423 corresponding to the cover 23. The following describes the differences from the first embodiment. The same reference numerals are used for the same components in the first and fourth embodiments, and detailed descriptions thereof will be omitted.

[0077] The heat sink 411 differs from the heat sink 11 in that the outer portion 440, which corresponds to the outer portion 111b located outside the forming portion 111a, has an inclined portion 441 inclined relative to the forming portion 111a and a parallel portion 442 extending from the end of the inclined portion 441 in a direction perpendicular to the vertical direction, in other words, parallel to the forming portion 111a. Cover 413 differs in that a central through hole 445 corresponding to central through hole 145 is formed throughout the entire top 141 (see Figure 3) and the entire short side portions 143 (see Figure 3) on both sides of top 141.

[0078] Therefore, the cooling device 4 has an inclined portion 441 that is provided outside the forming portion 111a and inclined toward the side where the multiple fins 112 are provided, and a parallel portion 442 that protrudes outward from the end of the inclined portion 441 parallel to the forming portion 111a, and the cover 413 has an outer peripheral portion 131 as an example of a parallel opposing portion that faces the parallel portion 442 outside the central through hole 445.

[0079] The heat sink 411 and the cover 413 are joined by laser welding by irradiating the outer periphery 131 of the cover 413 with laser light L at the overlapping portion of the parallel portion 442 of the heat sink 411 and the outer periphery 131 of the cover 413. That is, when manufacturing the cooling device 4, the laser light L is irradiated onto the outer peripheral portion 131 of the overlapping portion between the parallel portion 442 of the heat sink 411 and the outer peripheral portion 131 of the cover 413, which is a portion perpendicular to the up-down direction. Therefore, the overlapping portions between the parallel portion 442 of the heat sink 411 and the outer peripheral portion 131 of the cover 413, which are on both outer sides in the short direction of the central through-hole 445, can be irradiated with the laser light L from the same direction (for example, the up-down direction). [Explanation of symbols]

[0080] 1, 2, 3, 4, 5... cooling device, 10... first cooler, 11, 21, 411, 421... heat sink, 12, 22... case, 13, 23, 213, 223, 313, 323, 413, 423... cover, 20... second cooler, 40... first connecting member, 50... second connecting member, 60... support member, 80... pressure member, 100... semiconductor module, 101... main body, 102... terminal, 111... Base, 111a...Formation part, 111b,440...Outside part, 111c,441...Slope part, 112...Fin, 141,241...Top part, 141a,241a,341a...Outward facing part, 141b,2 41b, 341b...Middle opposing part, 141c...Support part, 143a, 243a...Edge, 145,345,445...Central through hole, 150...Laser device, 151...Laser head, 241c...Holding part

Claims

1. Two coolers arranged on either side of the heating element; a pressurizing member that is held by one of the two coolers and supported by the other of the two coolers, thereby elastically deforming and applying pressure to the two coolers so that the two coolers approach each other; Equipped with the pressing member is rectangular and flat, and a central portion in a longitudinal direction is held by the one cooler, and both ends in a longitudinal direction are supported by the other cooler; Cooling device.

2. a plurality of the heat generating elements are arranged between the two coolers in a direction in which the cooling liquid flows inside the coolers; The pressure member is provided between the plurality of heat generating elements. The cooling device of claim 1 .

3. The one cooler and the other cooler each include a heat sink having a plate-like base and a plurality of fins protruding from the base, and a housing that accommodates the plurality of fins and forms a flow path for a coolant, the housing having an opening formed at the bottom or top, the base being disposed so as to close the opening and such that a forming portion on which the plurality of fins are formed is exposed from the opening, and the housing has an outer opposing portion that is provided at the outer edge of the opening in the flow direction, and is opposed to and joined to the forming portion, and a middle opposing portion that is provided between both end portions of the opening in the flow direction, and is opposed to and joined to the forming portion, the pressurizing member is held by the middle opposing portion of the one cooler and supported by the middle opposing portion of the other cooler; The cooling device according to claim 2 .

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