Cooler and semiconductor module

Abstract

To make the temperature of a heating element uniform along a flowing direction of a refrigerant.SOLUTION: A cooler (1) includes: a top plate portion (2) having a first surface (201) facing a flow path (100) of a refrigerant and having a heating element (5) disposed on a back surface of the first surface; a bottom plate portion (300) having a second surface (301) facing the first surface of the top plate portion; a plurality of fins (410) arranged between the first surface of the top plate portion and the second surface of the bottom plate portion; and a frame portion (320) provided between the top plate portion and the bottom plate portion and having a wall surface surrounding the plurality of fins. The plurality of fins are arranged between the first surface of the top plate portion and the second surface of the bottom plate portion such that an arrangement density of fins in a first section (101A) of the flow path of the refrigerant is equal to an arrangement density of fins in second sections (101B, 101C) downstream of the first section, and a contact area between the fins and the top plate portion in the first section is smaller than a contact area between the fins and the top plate portion in the second sections.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a cooler and a semiconductor module. [Background technology]

[0002] Some coolers for cooling electronic components such as semiconductor devices have a plurality of fins arranged in a coolant flow path through which a coolant flows. In some coolers of this type, the density of the fins gradually increases from the inlet to the outlet in order to prevent a decrease in cooling efficiency from occurring as the coolant flows from the inlet to the outlet in the coolant flow path (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-153785 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned cooler, the temperature of the refrigerant gradually increases as it moves from the inlet to the outlet, making it difficult to equalize the temperature of the heating element near the inlet and the temperature of the heating element near the outlet.

[0005] The present invention has been made in view of the above points, and has as its object to make the temperature of the heating element uniform along the direction of flow of the refrigerant. [Means for solving the problem]

[0006] A cooler according to one aspect of the present invention includes a top plate having a first surface facing a refrigerant flow path and a heat generating element disposed on a backside of the first surface, a bottom plate having a second surface opposite the first surface of the top plate, a plurality of fins disposed between the first surface of the top plate and the second surface of the bottom plate, and a frame provided between the top plate and the bottom plate and having a wall surface surrounding the plurality of fins. The plurality of fins are disposed between the first surface of the top plate and the second surface of the bottom plate such that the arrangement density of the fins in a first section of the refrigerant flow path is the same as the arrangement density of the fins in a second section downstream of the first section, and the contact area between the fins and the top plate in the first section is smaller than the contact area between the fins and the top plate in the second section. [Effects of the Invention]

[0007] According to the present invention, the temperature of the heating element can be made uniform along the direction of flow of the coolant. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view of a cooler according to a first embodiment. [Figure 2] FIG. 2 is a plan view illustrating a flow path of a coolant. [Figure 3] 3A and 3B are a perspective view and a cross-sectional view, respectively, illustrating an example of the configuration of a corrugated fin. [Figure 4] 1 is a circuit diagram illustrating an example of a circuit configuration of a semiconductor module including a heating element. [Figure 5] FIG. 4 is a cross-sectional view illustrating an example of the wave shape of the corrugated fins in the first heat exchange section in the upstream portion. [Figure 6] FIG. 4 is a cross-sectional view illustrating the wave shape of the corrugated fins in the second heat exchange section in the midstream portion. [Figure 7] FIG. 10 is a cross-sectional view illustrating the wave shape of the corrugated fins in the downstream third heat exchange section. [Figure 8]10 is a side cross-sectional view illustrating a first contact state between the lower surface of the top plate and the upward bent portion of the corrugated fin. FIG. [Figure 9] 10 is a side cross-sectional view illustrating a second contact state between the lower surface of the top plate and the upward bent portion of the corrugated fin. FIG. [Figure 10] 10 is a side cross-sectional view illustrating a third contact state between the lower surface of the top plate and the upward bent portion of the corrugated fin. FIG. [Figure 11] 10 is a graph illustrating an example of the relationship between the shape of the corrugated fin and the temperature of the semiconductor element. [Figure 12] 10 is a graph illustrating the relationship between the presence or absence of a heat blocking region and the temperature of a semiconductor element. [Figure 13] FIG. 10 is a plan view of a cooler according to a second embodiment. [Figure 14] 10A and 10B are side cross-sectional views illustrating examples of the wave shape of the corrugated fin and the shape of the lower surface of the top plate. [Figure 15] 10 is a side cross-sectional view illustrating a second contact state between the lower surface of the top plate and the upward bent portion of the corrugated fin. FIG. [Figure 16] 10A and 10B are side cross-sectional views illustrating examples of the wave shape of the corrugated fins and the shape of the lower surface of the top plate in a cooler according to a third embodiment. [Figure 17] 10 is a side cross-sectional view illustrating a second contact state between the lower surface of the top plate and the upward bent portion of the corrugated fin. FIG. [Figure 18] 10 is a side cross-sectional view illustrating an example of the wave shape of the corrugated fins and the shape of the lower surface of the top plate in a cooler according to a fourth embodiment. FIG. [Figure 19] 19A and 19B are side cross-sectional views illustrating contact states between the lower surface of the top plate and the upper folded portions of the corrugated fins in the first heat exchange section in the upstream portion. [Figure 20] 10 is a side cross-sectional view illustrating a contact state between the lower surface of the top plate and the upper folded portion of the corrugated fin in the second heat exchange section in the midstream portion. FIG. [Figure 21] 10 is a cross-sectional side view illustrating a state in which the lower surface of the top plate and the upper folded portions of the corrugated fins are in contact with each other in the third heat exchange section in the downstream portion. FIG. [Figure 22] 22A to 22C are cross-sectional views illustrating fins of a cooler according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the X-axis, Y-axis, and Z-axis in each of the referenced figures are shown for the purpose of defining planes and directions in the illustrated coolers, etc. The X-axis, Y-axis, and Z-axis are orthogonal to each other and form a right-handed system. In the following description, the direction parallel to the X-axis will be referred to as the X-direction, the direction parallel to the Y-axis will be referred to as the Y-direction, and the direction parallel to the Z-axis will be referred to as the Z-direction. Furthermore, when relating the X-direction, Y-direction, and Z-direction to the directions of the arrows (positive and negative) of the X-axis, Y-axis, and Z-axis shown in the drawings, the "positive side" and "negative side" will be added.

[0010] In this specification, the Z direction is sometimes referred to as the up-down direction. In this specification, "up" and "above" refer to the positive side of the Z direction relative to a reference surface, component, position, etc., and "down" and "below" refer to the negative side of the Z direction relative to a reference surface, component, position, etc. For example, when describing "component B being placed on component A," component B is placed on the positive side of component A in the Z direction. Furthermore, when describing "the top surface of component A," this surface is the end of component A on the positive side of the Z direction, facing the positive side of the Z direction. These directions and surfaces are used for convenience of explanation, and their correspondence with the X-axis, Y-axis, and Z-axis directions may change depending on the installation posture of the cooler, etc. For example, the surface of a cooler on which a wiring board and semiconductor elements are placed is referred to as the top surface of the cooler in this specification, but may also be referred to as the bottom surface, side surface, etc. of the cooler. Furthermore, when the illustration on the printed page is an actual object rotated 90 degrees counterclockwise (such as Figure 5), the up-down and left-right directions are the directions obtained by rotating the up-down and left-right directions on the printed page by 90 degrees counterclockwise. For example, the "left side of the illustration" and the "right side of the illustration" in Figure 5 refer to the "bottom of the illustration" and the "top of the illustration" on the printed page, respectively.

[0011] The aspect ratios and relative sizes of components in each figure are merely schematic and do not necessarily correspond to the relationships in an actual cooler or other device. For convenience of explanation, the relative sizes of components may be exaggerated. Underlined symbols in the figures indicate symbols that refer to the entire component when a separate symbol is used to refer to a component. The letters in symbols represented by numbers and their following letters are intended solely to distinguish between the multiple components identified by the numbers. In the following description, the letters are omitted when multiple components are not distinguished by the letters following the numbers. For example, when referring to a specific heating element among the three heating elements 5A-5C, the symbol will be followed by the letter; otherwise, it will simply be referred to as "heating element 5." Furthermore, terms such as "first" and "second" in the following description are intended solely to distinguish between multiple components with the same name.

[0012] In the following description, detailed descriptions of the configuration, function, operation, manufacturing method, etc. of the illustrated cooler that are the same as or similar to those of known coolers will be omitted.

[0013] [First embodiment] FIG. 1 is a plan view of a cooler according to a first embodiment. FIG. 2 is a plan view illustrating a refrigerant flow path. FIG. 3 is a perspective view (FIG. 3A) and a cross-sectional view (FIG. 3B) illustrating an example of the configuration of a corrugated fin. FIG. 2 may be a view of the cooler 1 of FIG. 1 without the top plate 2 on which the heat generating element 5 is arranged. The cross-sectional view of FIG. 3B may be a cross-sectional view parallel to the YZ plane at a position x3 in the X direction illustrated in FIG. 2.

[0014] The cooler 1 illustrated in FIGS. 1 to 3 includes a top plate 2, a water jacket 3, and corrugated fins 4. The top plate 2 and the water jacket 3 are made of a metal or alloy with high thermal conductivity, such as aluminum or copper, and are manufactured by well-known methods such as casting, press processing, or a method using a 3D printer. The corrugated fins 4 are made by bending a metal plate, such as aluminum, copper, or stainless steel, into a corrugated shape, and are disposed within a refrigerant flow path 100 defined by the top plate 2 and the water jacket 3. The top plate 2 may also be referred to as a top plate portion.

[0015] The heating element 5 is disposed on the top surface 200 of the top plate 2, which is the outer surface (which may also be referred to as the outer surface) of the cooler 1. The illustrated top plate 2 is a rectangular plate-like member when viewed in a plan view (XY plan view) of the top surface 200, and three heating elements 5A to 5C are disposed along the longitudinal direction (X direction). The heating element 5 may be, for example, a circuit component including a wiring board 500 and a semiconductor element (semiconductor chip) 501 disposed on the top surface of the wiring board 500. The wiring board 500 may be a laminated substrate in which conductive plates (which may also be referred to as conductive patterns, conductive layers, conductor layers, etc.) made of copper or the like are disposed on the top and bottom surfaces of an insulating substrate made of ceramic, insulating resin, or the like, and the conductive plate disposed on the bottom surface of the insulating substrate is joined to the top surface 200 of the top plate 2 via a bonding material such as solder. The number of heating elements 5 disposed on the top surface 200 of the top plate 2 is not limited to three. The heating element 5 is not limited to the two semiconductor elements 501A and 501B arranged along the longitudinal direction of the upper surface 200 of the top plate 2 as illustrated in FIG. 1 . A plurality of heating elements 5 having different configurations may be arranged on the upper surface 200 of the top plate 2 via a bonding material such as solder. A case 6 having a frame-shaped portion surrounding the heating element 5 in a planar view may be arranged on the upper surface 200 of the top plate 2. The case 6 may include an insulating resin portion having a frame-shaped portion surrounding the heating element 5 in a planar view, and terminals electrically connected to the wiring (conductive plate) of the wiring board 500 of the heating element 5 or the electrodes of the semiconductor element 501. The heating element 5 and other components within the space surrounded by the case 6 may be sealed with epoxy resin or the like. The heating element 5 may be part of a resin-sealed semiconductor device (semiconductor package) such as a DIP (Dual Inline Package) type. In this specification, the assembly of one wiring board 500 and semiconductor elements 501 arranged on that wiring board 500 is referred to as heating element 5, but individual semiconductor elements 501 may also be referred to as heating elements.

[0016] The water jacket 3 is a component attached to the underside 201 of the top plate 2 to form the refrigerant flow path 100, and includes a bottom plate 300 and a frame 320 (see FIG. 8 for a specific configuration). In the illustrated water jacket 3, the bottom plate 300 is a rectangular plate-like portion in a plan view (XY plane view) of the top surface 301 facing the underside 201 of the top plate 2. The frame 320 is a quadrangular annular portion in an XY plane view located above the bottom plate 300. The frame 320 may be formed integrally with the bottom plate 300 or separately from the bottom plate 300. The separately formed bottom plate 300 and frame 320 may be joined by a bonding material, laser welding, ultrasonic welding, or fastened with bolts or the like. While FIG. 1 illustrates a cooler 1 in which the contours of the top plate 2 and the water jacket 3 coincide with each other, the contours of the top plate 2 and the water jacket 3 do not necessarily have to coincide with each other. The top plate 2 may have any shape as long as it can close (cover) the opening at the upper end of the frame portion 320 of the water jacket 3. The frame portion 320 of the cooler 1 may be formed integrally with the top plate 2.

[0017] Refrigerant flow path 100 of cooler 1 may be a substantially rectangular parallelepiped space defined by upper surface 301 of bottom plate 300, lower surface 201 of top plate 2, and inner circumferential wall surfaces 321A to 321D of frame 320 connecting upper surface 301 of bottom plate 300 and lower surface 201 of top plate 2. Refrigerant flow path 100 communicates with the outside of cooler 1 via first through-hole 110 formed in frame 320 so as to have one open end on first inner circumferential wall surface 321A located at one end in the longitudinal direction, and second through-hole 111 formed in frame 320 so as to have one open end on second inner circumferential wall surface 321C located at the other end in the longitudinal direction (see FIG. 2, etc.). In this specification, the first through hole 110 is used as a refrigerant inlet into the refrigerant flow path 100, and the second through hole 111 is used as a refrigerant outlet from the refrigerant flow path 100. That is, the illustrated cooler 1 is connected to a cooling circuit that circulates a refrigerant so that the refrigerant in the refrigerant flow path 100 flows toward the positive side in the X direction. In the following description, the first through hole 110 will be referred to as the refrigerant inlet 110, and the second through hole 111 will be referred to as the refrigerant outlet 111. In addition, in the following description, the X direction, Y direction, and Z direction in the refrigerant flow path 100 will be referred to as the refrigerant flow direction, flow path width direction, and flow path height direction, respectively.

[0018] As described above, a corrugated fin 4 formed by bending a metal plate into a corrugated shape is disposed within the refrigerant flow path 100 defined by the top plate 2 and the water jacket 3. The corrugated fin 4 is disposed within the refrigerant flow path 100 with the progression direction of the corrugation aligned with the width direction of the flow path (Y direction) and the amplitude direction of the corrugation aligned with the height direction of the flow path (Z direction). As illustrated in FIGS. 3A and 3B , the corrugated fin 4 disposed within the refrigerant flow path 100 has a plurality of plate-like portions 410 aligned in the width direction of the flow path, and a plurality of upward bent portions 420 and a plurality of downward bent portions 430 connecting adjacent plate-like portions 410 in the width direction of the flow path. The upward bent portions 420 are bent portions connecting adjacent plate-like portions 410 between the plate-like portions 410 and the top plate 2, and the downward bent portions 430 are bent portions connecting adjacent plate-like portions 410 between the plate-like portions 410 and the bottom plate 300. Adjacent plate-like portions 410 are connected by either an upward bent portion 420 or a downward bent portion 430 .

[0019] End faces 411, 412 of the plate-shaped portion 410 in the direction of the plate thickness D1 (hereinafter referred to as the "plate thickness direction") are used for heat exchange with the refrigerant. In the following description, the end faces 411, 412 of the plate-shaped portion 410 in the plate thickness direction are referred to as heat exchange surfaces 411, 412. Each plate-shaped portion 410 of the corrugated fin 4 is arranged parallel to the refrigerant flow direction (X direction) and extends in the refrigerant flow direction so that one end of the heat exchange surfaces 411, 412 in the refrigerant flow direction is located upstream of the first heat exchange section 101A (on the refrigerant inlet 110 side) and the other end is located downstream of the third heat exchange section 101C (on the refrigerant outlet 111 side). The term "heat exchange section" refers to a section within the refrigerant flow path 100 identified by its position in the refrigerant flow direction. It refers to the section from the upstream end of the area overlapping with the heating element 5 to the downstream end of the area in the XY plane view of FIGS. 1 and 2 . The first heat exchange section 101A may be a section in which heat exchange is performed to cool the first heating element 5A, which is located most upstream, and the third heat exchange section 101C may be a section in which heat exchange is performed to cool the third heating element 5C, which is located most downstream. Between the first heat exchange section 101A and the third heat exchange section 101C is a second heat exchange section 101B in which heat exchange is performed to cool the second heating element 5B. In the following description, when referring to the ends of the heat exchange surfaces 411, 412 and other corrugated fins 4 in the refrigerant flow direction, the end upstream of the first heat exchange section 101A is referred to as the "upstream end," and the end downstream of the third heat exchange section 101C is referred to as the "downstream end."

[0020] The dimensions of the shape of the corrugated fin 4, such as the thickness D1 of the plate-shaped portion 410 and the gap G1 (the distance between the opposing heat exchange surfaces) between adjacent plate-shaped portions 410, are not limited to specific dimensions. Furthermore, the thickness direction D1 of each plate-shaped portion 410 is not limited to a direction parallel to the flow path width direction (Y direction) as illustrated in FIG. 3B . For example, the corrugated fin 4 may be bent so that the gap G1 between two plate-shaped portions 410 connected to one bent portion increases with increasing distance from the bent portion. Furthermore, the shapes of the upper bent portion 420 and the lower bent portion 430 are not limited to specific shapes. The upper bent portion 420 and the lower bent portion 430 are not limited to the bent shape having a U-shaped cross section illustrated in FIG. 3B , but may also be bent to have a U-shaped cross section, for example. The dimensions of the corrugated fin 4, such as the plate thickness D1 and the gap G1, as well as the bending shape, can be set according to, for example, the size of the refrigerant flow path 100, the cooling performance required of the cooler 1, and the like.

[0021] The upper bent portions 420 and the lower bent portions 430 are each connected to the plate-shaped portion 410 over the entire section from the upstream end to the downstream end of the plate-shaped portion 410. The corrugated fin 4 may be fixed in the refrigerant flow path 100 with the lower bent portions 430 in contact with the upper surface 301 of the bottom plate portion 300 and joined to the upper surface 301 of the bottom plate portion 300 with a bonding material, laser welding, or ultrasonic welding. Furthermore, in at least the third heat exchange section 101C in the downstream portion of the refrigerant flow path 100 in the cooler 1 of this embodiment, as illustrated in FIG. 3B , all of the upper bent portions 420 of the corrugated fin 4 are in contact with the lower surface 201 of the top plate 2. Details of the contact state between the top plate 2 and the upper bent portions 420 of the corrugated fin 4 in the cooler 1 of this embodiment will be described later with reference to FIGS. 5 to 10 .

[0022] 4 is a circuit diagram illustrating an example of the circuit configuration of a semiconductor module including a heat generating element. The heat generating element 5 to be cooled by the cooler 1 may be a circuit component having a semiconductor element 501 arranged on the upper surface of a wiring board 500, as described above. The heat generating element 5 may be a circuit component having a half-bridge inverter circuit provided within a semiconductor module 7, as illustrated in FIG. 4. The heat generating element 5 may include a first switching element 711A and a second switching element 711B connected in series, and a first diode element 712A and a second diode element 712B connected in anti-parallel to the first switching element 711A and the second switching element 711B, respectively.

[0023] The wiring board 500 of the heating element 5 may be, for example, a direct copper bonding (DCB) substrate or an active metal brazing (AMB) substrate. The materials and forming methods of the insulating substrate and conductive plate in the wiring board 500 are not limited to specific materials and forming methods. The semiconductor element 501 may include one of two switching elements 711 connected in series and a diode element 712 connected in anti-parallel to the switching element 711. The switching element 711 may be, for example, an insulated gate bipolar transistor (IGBT), a power metal oxide semiconductor field effect transistor (MOSFET), or a bipolar junction transistor (BJT). The diode element 712 may be, for example, a free wheeling diode (FWD), a Schottky barrier diode (SBD), a junction barrier Schottky diode (JBS), a merged PN Schottky diode (MPS), or a PN diode. The number, type, and layout of semiconductor elements 501 arranged on wiring board 500 are not limited to a specific number, type, and layout. For example, semiconductor elements 501 may include a semiconductor element in which switching element 711 is formed and a semiconductor element in which diode element 712 is formed. Also, for example, a switching element shown as one element in FIG. 4 (e.g., first switching element 711A) may be formed by connecting switching elements formed on multiple semiconductor elements 501 in parallel.

[0024] When a half-bridge inverter circuit using an IGBT element as the switching element 711 is provided in the semiconductor module 7, the collector of the first switching element 711A is electrically connected to the first main terminal 701, and the emitter of the second switching element 711B is electrically connected to the second main terminal 702. The first main terminal 701 and the second main terminal 702 may be, for example, a P terminal connected to the positive electrode of a DC power supply and an N terminal connected to the negative electrode. The emitter of the first switching element 711A and the collector of the second switching element 711B are electrically connected to a third main terminal 703. The third main terminal 703 is connected, for example, to a load that consumes the AC output from the half-bridge inverter circuit. The gate of the first switching element 711A and the gate of the second switching element 711B are electrically connected to a first control terminal 704A and a second control terminal 704B, respectively. In the semiconductor module 7 including the case 6, the first main terminal 701, the second main terminal 702, the third main terminal 703, the first control terminal 704A, and the second control terminal 704B are, for example, conductive plates called leads, and are integrally formed in the insulating resin portion of the case 6. The case 6 may be provided with an additional control terminal in addition to the control terminal 704. The additional control terminal may be, for example, a control terminal called an auxiliary emitter terminal, an emitter sense terminal, or the like, electrically connected to the emitter of the switching element 711. The auxiliary emitter terminal is connected to a gate drive circuit that generates a control signal to be applied to the gate of the switching element 711. The additional control terminal may include, for example, a temperature sense terminal electrically connected to a temperature sensor unit that may be included in the semiconductor module 7 and that measures the temperature of the semiconductor element. When a power MOSFET is used as the switching element 711, the collector and emitter of the IGBT element described above are replaced with the drain and source. The circuit formed in the semiconductor module 7 is not limited to the half-bridge inverter circuit described above with reference to Fig. 4, but may be another circuit, or may be a circuit including an inverter circuit and another circuit. The case 6 may be omitted from the semiconductor module 7.

[0025] The cooler 1 of this embodiment cools the heat-generating element 5 by transferring heat generated by the heat-generating element 5 to the top plate 2 and the corrugated fins 4 and dissipating the heat through heat exchange between the top plate 2 and the corrugated fins 4 and the refrigerant. Therefore, the temperature of the refrigerant flowing through the refrigerant flow path 100 gradually increases from the inlet 110 to the outlet 111. Therefore, for example, if multiple semiconductor elements 501 arranged along the refrigerant flow direction (X direction) are made to perform substantially the same operation while being cooled by the cooler 1, the efficiency of heat exchange near the outlet 111 will be lower than the efficiency of heat exchange near the inlet 110. As a result, the temperature of the semiconductor elements 501 near the outlet 111 will be higher than the temperature of the semiconductor elements 501 near the inlet 110, which may cause variations in the operation of the semiconductor elements 501. 1, the temperature difference between the first heating element 5A near the inlet 110 and the third heating element 5C near the outlet 120 is likely to become large, which will tend to increase the variation in operation of each heating element 5. In the cooler 1 of this embodiment, the top plate 2 and the corrugated fins 4 are configured as described below with reference to FIGS. 5 to 10, thereby making it possible to equalize the temperatures of the multiple heating elements 5 arranged along the direction of refrigerant flow.

[0026] Fig. 5 is a cross-sectional view illustrating the wave shape of the corrugated fin in the first heat exchange section in the upstream portion. Fig. 6 is a cross-sectional view illustrating the wave shape of the corrugated fin in the second heat exchange section in the midstream portion. Fig. 7 is a cross-sectional view illustrating the wave shape of the corrugated fin in the third heat exchange section in the downstream portion. Fig. 8 is a side cross-sectional view illustrating a first contact state between the underside of the top plate and the upper bent portion of the corrugated fin. Fig. 9 is a side cross-sectional view illustrating a second contact state between the underside of the top plate and the upper bent portion of the corrugated fin. Fig. 10 is a side cross-sectional view illustrating a third contact state between the underside of the top plate and the upper bent portion of the corrugated fin.

[0027] The cross-sectional view of FIG. 5 may be an enlarged view of a portion of the cross-sectional view of the cooler 1 taken along the YZ plane at position x1 in the X direction shown in FIG. 2. The cross-sectional view of FIG. 6 may be an enlarged view of a portion of the cooler 1 taken along the YZ plane at position x2 in the X direction shown in FIG. 2. FIG. 7 may be an enlarged view of a portion of the cooler 1 taken along the YZ plane at position x3 in the X direction shown in FIG. 2. The side cross-sectional view of FIG. 8 is a view of a portion of the cooler 1 taken along the ZX plane including line A-A' in FIGS. 5 to 7, to the left of line A-A' in FIG. 5 (positive side in the Y direction), as viewed from the negative side in the Y direction. The side cross-sectional view of FIG. 9 is a view of a portion of the cooler 1 taken along the ZX plane including line B-B' in FIG. 5, to the left of line B-B' in FIG. 5 (positive side in the Y direction), as viewed from the negative side in the Y direction. The side cross-sectional view in Fig. 10 is a view of a portion of the cooler 1 cut along the ZX plane including the line CC' in Fig. 5 to Fig. 7, the portion being to the left of the line CC' in Fig. 5 (the positive side in the Y direction), as viewed from the negative side in the Y direction. Also, the dashed lines in the corrugated fins 4 in Figs. 8 to 10 indicate the surface of the top of the upward bent portion 420 (the portion in contact with the top plate 2) facing the upper surface 301 of the bottom plate portion 300. Furthermore, position x4 in Fig. 9 and position x5 in Fig. 10 correspond to positions x4 and x5 in the X direction, respectively, illustrated in Fig. 2.

[0028] In the cooler 1 of this embodiment, the contact state between the underside 201 of the top plate 2 and the upward bent portions 420 of the corrugated fins 4 can be roughly divided into three contact states. The first contact state is a state in which the entire section from the upstream end to the downstream end is in contact with the underside 201 of the top plate 2, as in the first upward bent portion 420A illustrated in FIGS. 5 to 7 and 8. The second contact state is a state in which the section from the upstream end to position x4 between the first heat exchange section 101A and the second heat exchange section 101B is separated from the underside 201 of the top plate 2, as in the second upward bent portion 420B illustrated in FIGS. 5 to 7 and 9. The third contact state is a state in which the section from the upstream end to position x5 between the second heat exchange section 101B and the third heat exchange section 101C is separated from the underside 201 of the top plate 2, and the section from position x5 to the downstream end is in contact with the underside 201 of the top plate 2, as in the third upward bending portion 420C illustrated in Figures 5 to 7 and 10.

[0029] 9 and 10, the lower surface 201 of the top plate 2 is parallel to the upper surface 301 (XY plane) of the bottom plate 300. Therefore, as shown in FIG. 9, the shape of the second upward bent portion 420B of the corrugated fin 4 is adjusted by adjusting the length of the plate-like portion 410 (the dimension in the flow path height direction (Z direction)). The height (fin length) from the lower end of the downward bent portion 430 to the upper end of the second upward bent portion 420B gradually increases from the upstream end toward position x4, and the height is constant in the section from position x4 to the downstream end. As a result, when the section of the second upward bent portion 420B from position x4 to the downstream end is brought into contact with the lower surface 201 of the top plate 2, the section from the upstream end of the second upward bent portion 420B to position x4 is separated from the lower surface 201 of the top plate 2. The distance (gap) G2 from the upstream end of the second upward bent portion 420B to the underside 201 of the top plate 2 may be, for example, 1 μm to 2 μm, but is not limited to a specific distance. The distance G2 may be, for example, about 1% to 2% of the dimension in the height direction of the refrigerant flow path 100 (or the height of the fin from the position x4 to the downstream end).

[0030] 10, the third upward bent portion 420C of the corrugated fin 4 is shaped such that the length of the plate-like portion 410 is adjusted so that the height from the lower end of the downward bent portion 430 to the upper end of the third upward bent portion 420C gradually increases from the upstream end toward position x5, and the height is constant in the section from position x5 to the downstream end. As a result, when the section of the third upward bent portion 420C from position x5 to the downstream end is brought into contact with the underside 201 of the top plate 2, the section of the third upward bent portion 420C from the upstream end to position x5 is spaced apart from the underside 201 of the top plate 2. The distance (gap) G3 between the upstream end of the third upward bent portion 420C and the underside 201 of the top plate 2 can be, for example, 1 μm to 2 μm, but is not limited to a specific distance.

[0031] The distances G2 and G3 may be the same or different. For example, the angle of inclination of the second upward bent portion 420B relative to the lower surface 201 of the table top 2 at a distance from the lower surface 201 may be the same as the angle of inclination of the third upward bent portion 420C relative to the lower surface 201 of the table top 2 at a distance from the lower surface 201 of the table top 2. Furthermore, the number and arrangement order of the first upward bent portions 420A, second upward bent portions 420B, and third upward bent portions 420C in the corrugated fin 4 are not limited to a specific number and order. When roughly divided into the three contact states described above, for example, the percentage of the upward bent portions 420 that contact the underside 201 of the top plate 2 in the first heat exchange section 101A can be 5% to 10%, the percentage of the upward bent portions 420 that contact the underside 201 of the top plate 2 in the second heat exchange section 101B can be 30% to 60%, and the percentage of the upward bent portions 420 that contact the underside 201 of the top plate 2 in the third heat exchange section 101C can be 100%. Also, for example, the second upward bent portions 420B and the third upward bent portions 420C may be arranged only within a range of the corrugated fin 4 in the flow path width direction (Y direction) that overlaps with the region where the heating element 5 is arranged in the XY plane view of FIGS. 5 and 6, the upper bent portions 420 of the corrugated fin 4 are not in uniform contact with the lower surface 201 of the top plate 2 depending on the position in the flow path width direction (Y direction), and have a fin structure in which some of the upper bent portions 420 are in contact with the lower surface 201 (420A) and others are separated from the lower surface 201 (420C). However, the corrugated fin 4 is not limited to such a structure, and for example, the corrugated fin 4 may be formed only with fins in which the tops of the upper bent portions 420 are separated from the lower surface 201 in the upstream portion.

[0032] The corrugated fin 4 according to this embodiment can be easily formed, for example, by changing the shape of a mold used to produce the corrugated fin 4 by press working to a shape that allows for the formation of the second upward bent portion 420B and the third upward bent portion 420C. Note that the method for forming the corrugated fin 4 is not limited to a specific method.

[0033] Direct heat transfer from the top plate 2 to the upward bent portion 420 of the corrugated fin 4 occurs within the region of the upward bent portion 420 that is in contact with the top plate 2 (thermal contact region 421). When viewed in the refrigerant flow direction (X direction), the entire region of the first upward bent portion 420A from the upstream end to the downstream end is the thermal contact region 421. In contrast, when viewed in the refrigerant flow direction, the second upward bent portion 420B and the third upward bent portion 420C have a heat blocking region 422 upstream of the thermal contact region 421, where the direct heat transfer from the top plate 2 is blocked by the refrigerant flowing between the upper surface of the upward bent portion 420 and the underside 201 of the top plate 2. That is, in the cooler 1 of this embodiment, the number (area) of the thermal contact regions 421 when viewed in the flow path width direction (Y direction) increases from upstream to downstream. In other words, in the cooler 1 of this embodiment, the fins (plate-shaped portions 410) are arranged at the same interval G1 (see Figure 3B) from upstream to downstream, and the area of ​​the thermal contact region 421 in a planar view of the underside 201 of the top plate 2 increases gradually from upstream to downstream.

[0034] The heat transferred from the top panel 2 to the upwardly bent portion 420 further transfers (heat transfers) to the plate-shaped portion 410 connected to the upwardly bent portion 420, and is dissipated into the refrigerant through heat exchange between the heat exchange surfaces 411, 412 of the plate-shaped portion 410 and the refrigerant. Since heat transfer from the first upwardly bent portion 420A occurs over the entire plate-shaped portion 410A connected to the first upwardly bent portion 420A from its upstream end to its downstream end, the entire region from its upstream end to its downstream end can be considered as the heat contact region 421. On the other hand, for the plate-shaped portion 410B connected to the second upwardly bent portion 420B, the region from its upstream end to position x4 can be considered as the heat blocking region 422, and the region from position x4 to its downstream end can be considered as the heat contact region 421. Similarly, the plate-shaped portion 410C connected to the third upward bending portion 420C can be considered to have a heat blocking area 422 from the upstream end to position x5, and a heat contact area 421 from position x5 to the downstream end.

[0035] 5, in the first heat exchange section 101A at the upstream portion of the refrigerant flow path 100, only the first upward bent portion 420A is in contact with the underside 201 of the top plate 2, and the second upward bent portion 420B and the third upward bent portion 420C are spaced apart from the underside 201 of the top plate 2. In other words, in the first heat exchange section 101A, heat exchange effective for cooling the heat-generating element 5 occurs only between the plate-shaped portion 410A connected to the first upward bent portion 420A and the refrigerant, and substantially no heat exchange occurs between the other plate-shaped portions 410B, 410C and the refrigerant. Therefore, of the refrigerant that flows within the first heat exchange section 101A, the refrigerant that flows between adjacent plate-shaped portions 410B connected to the second upward bending portion 420B and the refrigerant that flows between adjacent plate-shaped portions 410C connected to the third upward bending portion 420C flow into the second heat exchange section 101B at a lower temperature than the refrigerant that flows along the heat exchange surfaces 411, 412 of the plate-shaped portion 410A connected to the first upward bending portion 420A.

[0036] 6, in the second heat exchange section 101B, the first upward bent portion 420A and the second upward bent portion 420B are in contact with the underside 201 of the top plate 2, and the third upward bent portion 420C is spaced apart from the underside 201 of the top plate 2. That is, in the second heat exchange section 101B, heat exchange effective for cooling the heat-generating element 5 occurs between the plate-shaped portion 410A connected to the first upward bent portion 420A and the refrigerant, and between the plate-shaped portion 410B connected to the second upward bent portion 420B and the refrigerant, but heat exchange does not substantially occur between the plate-shaped portion 410C connected to the third upward bent portion 420C and the refrigerant. As described above, the temperature of the refrigerant exchanging heat with the plate-shaped portion 410A connected to the first upward bent portion 420A is increased by heat exchange in the first heat exchange section 101A, while the temperature of the refrigerant exchanging heat with the plate-shaped portion 410B connected to the second upward bent portion 420B remains relatively low. Therefore, the efficiency of heat exchange between the plate-shaped portion 410B and the refrigerant is higher than the efficiency of heat exchange between the plate-shaped portion 410A and the refrigerant. This reduces the difference in temperature between the semiconductor element 501 of the second heating element 5B, which is cooled by heat exchange in the second heat exchange section 101B, and the semiconductor element 501 of the first heating element 5A, which is cooled by heat exchange in the first heat exchange section 101A. Furthermore, of the refrigerant that flows within the second heat exchange section 101B, the refrigerant that flows between adjacent plate-shaped portions 410C connected to the third upward bending portion 420C flows into the third heat exchange section 101C at a lower temperature than the refrigerant that flows along the heat exchange surfaces 411, 412 of the plate-shaped portion 410A connected to the first upward bending portion 420A and the refrigerant that flows along the heat exchange surfaces 411, 412 of the plate-shaped portion 410B connected to the second upward bending portion 420B.

[0037] 7, in the third heat exchange section 101C, the first upward bent portion 420A, the second upward bent portion 420B, and the third upward bent portion 420C are all in contact with the underside 201 of the top plate 2. That is, in the third heat exchange section 101C, heat exchange effective for cooling the heat-generating element 5 occurs between the plate-shaped portion 410A connected to the first upward bent portion 420A and the refrigerant, between the plate-shaped portion 410B connected to the second upward bent portion 420B and the refrigerant, and between the plate-shaped portion 410B connected to the third upward bent portion 420C and the refrigerant. At this time, the efficiency of heat exchange between the plate-shaped portion 410C and the refrigerant is higher than the efficiency of heat exchange between the plate-shaped portion 410A and the refrigerant and the efficiency of heat exchange between the plate-shaped portion 410B and the refrigerant. Therefore, the difference between the temperature of the semiconductor element 501 of the third heating element 5C, which is cooled by heat exchange within the third heat exchange section 101C, and the temperature of the semiconductor element 501 of the second heating element 5B, which is cooled by heat exchange within the second heat exchange section 101B, can be reduced.

[0038] In the cooler 1 of this embodiment, the upward bent portions 420 of the corrugated fins 4 are divided into upward bent portion 420A that contacts the underside 201 of the top plate 2 from the upstream end to the downstream end, and upward bent portions 420B and 420C that slope upstream of the section that contacts the underside 201 of the top plate 2, gradually increasing the distance from the underside 201 toward the upstream side. This provides a heat shielding area 422 in the first heat exchange section 101A at the upstream side and the second heat exchange section 101B at the midstream side of the three heat exchange sections 101A to 101C aligned in the refrigerant flow direction. Therefore, in the cooler 1 of this embodiment, the fins (plate-shaped portions 410) are arranged at the same interval G1 (see FIG. 3B ) from upstream to downstream, and the area of ​​the heat contact area 421 in a plan view of the underside 201 of the top plate 2 can be increased stepwise from upstream to downstream. That is, the cooler 1 of this embodiment can gradually increase the area of ​​the thermal contact region 421 from upstream to downstream without changing the arrangement density of the fins (plate-shaped portions 410) in the refrigerant flow direction (X direction). Therefore, compared to the semiconductor cooling device illustrated in Cited Document 1, in which the fin arrangement density increases from upstream to downstream, the temperature difference of the heat-generating body 5 can be reduced while suppressing an increase in pressure loss in the downstream portion. Note that the fin arrangement density refers to the number of fins per unit length in the flow path width direction (Y direction) in the cross section of the cooler viewed from the refrigerant flow direction (X direction). Furthermore, the cooler 1 of this embodiment has a heat shielding region 422, which reduces the number of fins (plate-shaped portions 410) that contribute to heat exchange with the refrigerant in the heat exchange section in the upstream portion compared to the number in the downstream portion, thereby suppressing the temperature rise due to heat exchange of the refrigerant flowing between the fins. Therefore, compared to the semiconductor cooling device illustrated in cited document 1 in which the clearance between the fins protruding from the underside of the metal base and the flow path cover becomes smaller going from upstream to downstream, it is possible to suppress, for example, an increase in the dimension in the flow path height direction (Z direction), thereby suppressing a reduction in the freedom of installation location of the semiconductor module equipped with the cooler 1, and an increase in the weight of the equipment in which the semiconductor module equipped with the cooler 1 is installed.

[0039] Fig. 11 is a graph illustrating the relationship between the shape of the corrugated fin and the temperature of the semiconductor element. Fig. 12 is a graph illustrating the relationship between the presence or absence of a heat blocking area and the temperature of the semiconductor element.

[0040] The shape of the corrugated fin 4 used in the cooler 1 of this embodiment is not limited to a specific shape as described above. For example, the corrugated fin 4 may have unevenness on the heat exchange surfaces 411, 412 of the plate-shaped portion 410. The unevenness on the heat exchange surfaces 411, 412 may be created by, for example, forming dimples or grooves on the heat exchange surfaces 411, 412 by press processing, etching, or the like, or by bending (bending) the plate-shaped portion 410. When the corrugated fin 4 having unevenness on the heat exchange surfaces 411, 412 is arranged in the refrigerant flow path 100, the unevenness on the heat exchange surfaces 411, 412 causes turbulence in the refrigerant flowing along the heat exchange surfaces 411, 412. For example, a relatively high-temperature refrigerant flowing near the top plate 2 and a relatively low-temperature refrigerant flowing near the bottom plate 300 are mixed. Therefore, the temperature of the refrigerant exchanging heat with the portion of the plate-shaped portion 410 close to the top plate 2, which becomes relatively hot, can be lowered, and the heat exchange efficiency can be improved compared to the plate-shaped portion 410 having flat heat exchange surfaces 411, 412 illustrated in FIGS. 3A and 3B. The graph in FIG. 11 shows a comparison example between the cooling efficiency of the cooler 1 in which corrugated fins 4 having flat heat exchange surfaces 411, 412 are arranged and the cooling efficiency of the cooler 1 in which corrugated fins 4 having uneven heat exchange surfaces 411, 412 are arranged. In the graph in FIG. 11, the horizontal axis represents the distance from the upstream end of the corrugated fin 4, and the vertical axis represents the temperature of the semiconductor element 501. x1 to x5 on the upper horizontal axis represent positions x1 to x5 in the X direction illustrated in FIG. 2. The diamonds in the graph illustrate the relationship between the position and temperature of the semiconductor element 501 when a corrugated fin 4 having flat heat exchange surfaces 411, 412 is arranged, and the circles illustrate the relationship between the position and temperature of the semiconductor element 501 when a corrugated fin 4 having uneven heat exchange surfaces 411, 412 is arranged. The position of the semiconductor element 501 can be the distance from the upstream end of the corrugated fin to the center of the semiconductor element 501 when six semiconductor elements 501 are arranged in the flow direction of the refrigerant (X direction) as illustrated in FIG.Regardless of the type of corrugated fin used, the temperature of the semiconductor element 501 increases with distance from the upstream end. However, the temperature of each semiconductor element 501 when corrugated fins 4 having irregularities on the heat exchange surfaces 411, 412 are used is generally lower than the temperature of each semiconductor element 501 when corrugated fins 4 having flat heat exchange surfaces 411, 412 are used. Note that the graph in Figure 11 merely shows an example of the temperature difference between the case where the heat exchange surfaces 411, 412 have irregularities and the case where they are flat. The extent to which the temperature of the semiconductor element 501 can be lowered depends on the type of semiconductor element 501, the type of irregularities provided on the heat exchange surfaces 411, 412, and other factors.

[0041] Furthermore, the graph in FIG. 12 shows a comparison of the cooling efficiency when the corrugated fin 4 does not have the heat blocking region 422 and when the heat blocking region 422 is provided. In the graph in FIG. 12, the horizontal axis represents the distance from the upstream end of the corrugated fin 4, and the vertical axis represents the temperature difference from the average temperature of the semiconductor elements 501. The average temperature of the semiconductor elements 501 can be the average value of the temperatures of six semiconductor elements 501 arranged in the refrigerant flow direction (X direction). The circles in the graph indicate the relationship between the position and temperature of the semiconductor elements 501 when the heat blocking region 422 is not provided, and the squares indicate the relationship between the position and temperature of the semiconductor elements 501 when the heat blocking region 422 is provided. When the heat blocking region 422 is provided, the semiconductor elements 501 in the third heat exchange section 101C can be cooled by the refrigerant that has passed through the first heat exchange section 101A and the second heat exchange section 101B while remaining at a relatively low temperature. For this reason, when heat blocking area 422 is provided, it is possible to reduce the temperature variation among six semiconductor elements 501 compared to when heat blocking area 422 is not provided, in other words, to uniformize the temperature of multiple semiconductor elements 501. Whether heat exchange surfaces 411, 412 have irregularities or are flat, it is possible to expect uniformity of the temperature of semiconductor elements 501 equivalent to the graph in FIG.

[0042] In the cooler 1 of the present embodiment described above, in order to increase the contact area between the upward bent portions 420 of the corrugated fin 4 and the underside 201 of the top plate 2 from upstream to downstream, some of the plate portions 410 of the corrugated fin 4 are shaped to have heat-blocking regions 422 that block direct heat transfer from the top plate 2, located upstream of the heat contact regions 421 through which direct heat transfer from the top plate 2 occurs. Specifically, the upward bent portions 420 of the corrugated fin 4 located between the plate portions 410 and the top plate 2 are inclined with respect to the underside 201 of the top plate 2 to provide the heat-blocking regions 422 spaced apart from the underside 201, so that the number of heat contact regions 421 at each position in the refrigerant flow direction (X direction) increases from upstream to downstream. This allows the temperature of multiple semiconductor elements 501 arranged along the refrigerant flow direction to be uniform without changing the arrangement density of the fins (plate portions 410) between the upstream and downstream portions. Furthermore, the corrugated fins 4, each having a heat-shielding region 422 corresponding to the number and layout of the heat-generating elements 5 to be arranged on the upper surface 200 of the top plate 2, can be arranged in the refrigerant flow path 100, thereby providing high versatility for the top plate 2 and the water jacket 3. Therefore, compared to the cooler disclosed in Patent Document 1, in which the heat dissipation fins are integrally formed with the top plate so that the density increases from upstream to downstream of the refrigerant flow path, the cooler 1 of this embodiment can easily and inexpensively manufacture a cooler 1 capable of uniforming the temperature of multiple semiconductor elements 501. Furthermore, while the pressure loss of the cooler disclosed in Patent Document 1 changes with the density of the heat dissipation fins, the cooler 1 of this embodiment has a constant arrangement density (arrangement spacing) of the plate-like portions 410 of the corrugated fins 4 in the refrigerant flow direction from the upstream end to the downstream end, resulting in no substantial change in the pressure loss of the refrigerant flowing along the plate-like portions 410. Therefore, the cooler 1 of this embodiment can suppress a decrease in cooling performance due to changes in pressure loss.

[0043] [Second embodiment] FIG. 13 is a plan view of a cooler according to a second embodiment. FIG. 14 is a side cross-sectional view illustrating the wave shape of the corrugated fin and the shape of the underside of the top plate. FIG. 15 is a side cross-sectional view illustrating a second contact state between the underside of the top plate and the upward bent portion of the corrugated fin. The side cross-sectional view of FIG. 14 may be an enlarged view of a portion of the cooler 1 cut along the YZ plane at position x1 in the first heat exchange section 101A of the upstream portion illustrated in FIG. 13. The side cross-sectional view of FIG. 15 is a view of a portion of the cooler 1 cut along the ZX plane including line D-D' in FIG. 14, to the left of line D-D' in FIG. 14 (positive side in the Y direction), as viewed from the negative side in the Y direction. The dashed line in the corrugated fin 4 in FIG. 15 indicates the surface of the apex of the downward bent portion 430 (the portion in contact with the upper surface 301 of the bottom plate portion 300) facing the underside 201 of the top plate 2.

[0044] In the cooler 1 of this embodiment, grooves 202A and 202B are formed in the underside 201 of the top plate 2 to separate the upper bent portions 420 of the corrugated fin 4 from the underside 201, so that the contact area between the upper bent portions 420 of the corrugated fin 4 and the underside 201 of the top plate 2 increases from upstream to downstream, as illustrated in FIGS. 13 to 15 . The grooves 202 are formed in areas that overlap with the upper bent portions 420 of the corrugated fin 4 and the heat blocking areas 422 provided on the plate-like portions 410 in a plan view of the underside 201 of the top plate 2. That is, in the cooler 1 of this embodiment, too, the number of heat contact areas 421 at each position in the refrigerant flow direction (X direction) can be increased from upstream to downstream without changing the arrangement density of the fins (plate-like portions 410) between the upstream and downstream portions. In the corrugated fin 4 according to this embodiment, the heights of the second and third upward bent portions 420B and 420C described in the first embodiment from the upper surface 301 of the bottom plate portion 300 may be constant from the upstream end to the downstream end in the refrigerant flow direction (X direction), similar to the first upward bent portion 420A. That is, the second and third upward bent portions 420B and 420C in the corrugated fin 4 according to this embodiment do not have to have an inclined shape (see FIGS. 9 and 10 ) to provide the heat blocking region 422. Furthermore, the plate portion 410 of the corrugated fin 4 according to this embodiment may have flat heat exchange surfaces 411 and 412 or may have irregularities.

[0045] As described in the first embodiment, the first upward bent portion 420A makes the entire area from the upstream end to the downstream end in the refrigerant flow direction into the thermal contact area 421. For this reason, no groove separating the top plate 2 from the first upward bent portion 420A is formed in the area of ​​the underside 201 of the top plate 2 that overlaps with the first upward bent portion 420A in a plan view of the underside 201.

[0046] As described in the first embodiment, the second upward bent portion 420B defines a heat blocking region 422 from its upstream end in the refrigerant flow direction to a position x4 between the first heat exchange section 101A and the second heat exchange section 101B, and a heat contact region 421 from the position x4 to its downstream end. Therefore, a first groove 202A extending from the upstream end of the second upward bent portion 420B in the refrigerant flow direction to position x4 is formed in a region of the underside 201 of the top plate 2 that overlaps with the second upward bent portion 420B in a plan view. Furthermore, as described in the first embodiment, the third upward bent portion 420C defines a heat blocking region 422 from its upstream end in the refrigerant flow direction to a position x5 between the second heat exchange section 101B and the third heat exchange section 101C, and a heat contact region 421 from the position x5 to its downstream end. For this reason, a second groove 202B extending from the upstream end of the third upward bent portion 420C in the refrigerant flow direction to position x5 is formed in an area of ​​the underside 201 of the top plate 2 that overlaps with the third upward bent portion 420C in a plan view. The first groove 202A and the second groove 202B may have their upstream ends in the refrigerant flow direction positioned upstream (on the negative side in the X direction) of the upstream ends of the second upward bent portion 420B and the third upward bent portion 402C, as in the first groove 202A illustrated in FIG.

[0047] The groove 202 may have a depth (Z-direction dimension) G4 and a width (Y-direction dimension) W1 such that the heat shielding regions 422 of the second upward bent portion 420B and the third upward bent portion 420C do not come into contact with the top plate 2. The depth G4 of the groove 202 formed in the underside 201 of the top plate 2 may be, for example, 1 μm to 2 μm, but is not limited to a specific depth. The width W1 of the groove 202 may be, for example, 0.1 to 1.0 mm, but is not limited to a specific width. The groove 202 can be easily formed, for example, by a cutting process such as a well-known milling process or a routing process, or by a press process. The number and arrangement order of the first grooves 202A and the second grooves 202B formed in the underside 201 of the top plate 2 are not limited to a specific number and arrangement order. The groove 202 is not limited to a shape having a flat bottom surface, and may be, for example, a shape having a concave curved surface corresponding to the upper surface (convex curved surface) of the upward bent portion 420. Furthermore, groove 202 may be formed, for example, so that depth G4 becomes shallower and / or width W1 becomes narrower from upstream to downstream. Furthermore, grooves may be formed on underside 201 of top plate 2, for example, having a concave shape corresponding to the convex shape of thermal contact area 421 of upward bent portion 420 to ensure a contact area with thermal contact area 421, and grooves 202 may be formed upstream of the grooves to separate upward bent portion 420 from top plate 2. In addition, grooves 202 in cooler 1 according to this embodiment may be provided at locations corresponding to all upward bent portions 420 of corrugated fin 4 in a cross section perpendicular to the refrigerant flow direction (X direction).

[0048] In the cooler 1 of this embodiment, the number, formation positions, dimensions, etc. of the grooves 202 on the lower surface 201 can be changed depending on the number and layout of the heat generating elements 5 to be arranged on the upper surface 200 of the top plate 2, and the water jacket 3 and the corrugated fins 4 are highly versatile. Therefore, compared to a cooler in which heat dissipation fins are formed integrally with the top plate and arranged so that the density increases from upstream to downstream in the refrigerant flow path, as in Patent Document 1, for example, the cooler 1 capable of uniforming the temperature of multiple semiconductor elements 501 can be manufactured simply and inexpensively.

[0049] [Third embodiment] FIG. 16 is a side cross-sectional view illustrating the wave shape of the corrugated fins and the shape of the underside of the top plate in a cooler according to the third embodiment. FIG. 17 is a side cross-sectional view illustrating a second contact state between the underside of the top plate and the upward bent portion of the corrugated fin. The side cross-sectional view in FIG. 16 may be an enlarged view of a portion of the cooler 1 cut along the YZ plane at position x1 in the first heat exchange section 101A in the upstream portion illustrated in FIG. 2. The side cross-sectional view in FIG. 17 is a view of the cooler 1 cut along the ZX plane including line E-E' in FIG. 16, showing a portion of the cooler 1 to the left of line E-E' in FIG. 16 (positive side in the Y direction) and viewed from the negative side in the Y direction. The dashed line in the corrugated fin 4 in FIG. 17 indicates the surface of the apex of the downward bent portion 430 (the portion in contact with the upper surface 301 of the bottom plate portion 300) facing the underside 201 of the top plate 2.

[0050] 16 and 17 , in order to increase the contact area between the upward bent portions 420 of the corrugated fins 4 and the underside 201 of the top plate 2 from upstream to downstream, the tops of the regions to be heat-blocking regions 422 in some of the upward bent portions 420 of the corrugated fins 4 are flattened by cutting or polishing to separate them from the underside 201 of the top plate 2. That is, in the cooler 1 of this embodiment, the number (area) of the heat contact regions 421 at each position in the refrigerant flow direction (X direction) can also be increased from upstream to downstream without changing the arrangement density of the fins (plate-like portions 410) between the upstream and downstream portions. The corrugated fin 4 according to this embodiment may be formed by forming all of the upward bent portions 420 so that the height (fin length) from the upper surface 301 of the bottom plate portion 300 is constant from the upstream end to the downstream end, and then forming flat surfaces 423B and 423C by cutting, grinding, or the like in the heat-blocking regions of the second upward bent portion 420B and the third upward bent portion 420C. The flat surface 423B of the second upward bent portion 420B is formed, for example, from the upstream end in the refrigerant flow direction (X direction) to a position x4 between the first heat exchange section 101A and the second heat exchange section 101B. The flat surface 423C of the third upward bent portion 420C is formed, for example, from the upstream end in the refrigerant flow direction to a position x5 between the second heat exchange section 101B and the third heat exchange section 101C. In the cooler 1 of this embodiment, the underside 201 of the top plate 2 can be a flat surface parallel to the upper surface of the bottom plate portion 300, similar to the cooler 1 of the first embodiment. Therefore, in the corrugated fin 4 of this embodiment, the length of the fin in the heat blocking region 422 is shorter than that of the heat contact region 421, and a gap is formed between the tips of the second upward bent portion 420B and the third upward bent portion 420C that form the heat blocking region 422 and the underside 201 of the top plate 2.

[0051] The flat surface 423 can be formed, for example, so that the step occurring at the boundary between the heat blocking region 422 and the heat contact region 421 (in other words, the distance G5 from the flat surface 423 in the heat blocking region 422 to the underside 201 of the top plate 2 illustrated in FIG. 17 ) is 1 μm to 2 μm. The flat surface 423 can be easily formed, for example, by well-known milling or routing. Alternatively, for example, the shape of a mold used in the step of forming the corrugated fin 4 by press working may be modified to include a portion that flattens and compresses the portion of the upward bent portion 420 that will become the heat blocking region 422, and the flat surface 423 may be formed by press working. Furthermore, the heat exchange surfaces 411 and 412 of the plate-like portion 410 of the corrugated fin 4 according to this embodiment may be flat or may have irregularities.

[0052] The number and arrangement order of the first upward bent portion 420A, the second upward bent portion 420B, and the third upward bent portion 420C in the corrugated fin 4 according to this embodiment are not limited to a specific number and order. In addition, the flat surface 423 may be formed such that the distance G5 from the lower surface 201 of the top plate 2 decreases from the upstream side to the downstream side, for example.

[0053] [Fourth embodiment] Fig. 18 is a side cross-sectional view illustrating the wave shape of the corrugated fins and the shape of the underside of the top plate in a cooler according to a fourth embodiment. Figs. 19A and 19B are side cross-sectional views illustrating the contact state between the underside of the top plate and the upper bent portions of the corrugated fins in the first heat exchange section in the upstream portion. Fig. 20 is a side cross-sectional view illustrating the contact state between the underside of the top plate and the upper bent portions of the corrugated fins in the second heat exchange section in the midstream portion. Fig. 21 is a side cross-sectional view illustrating the contact state between the underside of the top plate and the upper bent portions of the corrugated fins in the third heat exchange section in the downstream portion.

[0054] The side cross-sectional view of FIG. 18 may be, for example, an enlarged view of a portion of the cooler 1 cut along the ZX plane at the same position in the flow path width direction (Y direction) as line A-A' in FIG. 5. The side cross-sectional view of FIG. 19A may be a view of the cooler 1 cut along the YZ plane including line F-F' in FIG. 18, showing a portion to the right of line F-F' in FIG. 18 (positive side in the X direction) and viewed from the negative side in the X direction. The side cross-sectional view of FIG. 19B may be a view of the cooler 1 cut along the YZ plane including line G-G' in FIG. 18, showing a portion to the right of line G-G' in FIG. 18 (positive side in the X direction) and viewed from the negative side in the X direction. The side cross-sectional view of FIG. 20 may be a view of the cooler 1 cut along the ZX plane including line H-H' in FIG. 18, showing a portion to the right of line H-H' in FIG. 18 (positive side in the X direction) and viewed from the negative side in the X direction. The side cross-sectional view in Fig. 21 may be a view of the cooler 1 cut along the YZ plane including line J-J' in Fig. 18, at a portion to the right of line J-J' in Fig. 18 (positive side in the X direction), as viewed from the negative side in the X direction. The dashed lines in the corrugated fin 4 in Fig. 19 indicate the surface facing the upper surface 301 of the bottom plate portion 300 at the top of the upward bent portion 420. Hatching indicating cross sections of the top plate 2, the plate-like portion 410 of the corrugated fin 4, the upward bent portion 420, etc. is omitted in Figs. 19A, 19B, 20, and 21.

[0055] In the cooler 1 of this embodiment, in order to increase the contact area between the upward bent portions 420 of the corrugated fin 4 and the underside 201 of the top plate 2 from upstream to downstream, the underside 201 of the top plate 2 is inclined so that the distance to the upper surface 301 of the bottom plate portion 300 (not shown) decreases from upstream to downstream, as illustrated in Fig. 18. The corrugated fin 4 used in the cooler 1 of this embodiment may be formed so that the height from the lower end of the downward bent portion 430 to the upper end of the upward bent portion 420 (fin length) is constant from the upstream end to the downstream end at all of the upward bent portions 420. In the cooler 1 of this embodiment, during the assembly process of the cooler 1, the underside 201 of the top plate 2 is pressed against the upward bent portions 420 of the corrugated fins 4, and the upward bent portions 420 are deformed so that the contact area per unit length between each of the upward bent portions 420 and the underside 201 of the top plate 2 in the flow direction (X direction) of the refrigerant increases from upstream to downstream. The term "contact area per unit length" refers to the contact area between the upward bent portion 420 and the underside 201 of the top plate 2 within a section of a unit length (e.g., 1 mm) in the flow direction of the refrigerant.

[0056] 19A, where the upper bent portion 420 is spaced apart from the underside 201 of the top plate 2, and a heat contact region 421, where the contact area per unit length between the upper bent portion 420 and the underside 201 of the top plate 2 is small, where the upper bent portion 420 is spaced apart from the underside 201 of the top plate 2, as shown in Fig. 19B. At a position close to the upstream end of the first heat exchange section 101A, the thickness H0 of the top plate 2 is thin, as shown in Fig. 19A, and the underside 201 of the top plate 2 is spaced apart from the upper bent portion 420 by a gap G6 (>0), thereby blocking direct transfer of heat from the top plate 2 to the corrugated fins 4 (upper bent portion 420). 19A in the first heat exchange section 101A, the top plate 2 has a thickness H1 (>H0) and the underside 201 of the top plate 2 comes into contact with the upward bent portion 420, as shown in FIG. 19B. The boundary between the heat shielding region 422 and the heat contact region 421 in the first heat exchange section 101A is not limited to a specific position, but it is preferable to position it so that at least a portion of the active region located most upstream in the first heat exchange section 101A (for example, the region overlapping with the semiconductor element 501 in a plan view) is included in the heat contact region 421. The active region may be the region of the heat-generating element 5 arranged in the heat exchange section 101 that overlaps with the heat source in a plan view and has the highest temperature.

[0057] 19B in the refrigerant flow direction (X direction), the top plate 2 has a thickness H2 (>H1) as shown in Fig. 20, the upward bent portion 420 is deformed by the pressure load from the underside 201 of the top plate 2, and the contact area between the underside 201 of the top plate 2 and the upward bent portion 420 increases to a width W2. In the third heat exchange section 101C, which is further downstream in the refrigerant flow direction (X direction) than the position shown in Fig. 20, the top plate 2 has a thickness H3 (>H2) as shown in Fig. 21, the amount of deformation of the upward bent portion 420 due to the pressure load from the underside 201 of the top plate 2 increases, and the contact area between the underside 201 of the top plate 2 and the upward bent portion 420 increases to a width W3 (>W2).

[0058] As described above, in the cooler 1 of this embodiment, the contact area per unit length between the underside 201 of the top plate 2 and the upward bent portion 420 increases from upstream to downstream. Therefore, even if the arrangement density of the fins (plate-like portions 410) is the same between the upstream and downstream portions, the amount of heat transferred from the top plate 2 to the upward bent portion 420 increases from upstream to downstream. In other words, by reducing the amount of heat transferred from the top plate 2 to the upward bent portion 420 in the first heat exchange section 101A in the upstream portion, the degree of increase in the temperature of the refrigerant due to heat exchange in the first heat exchange section 101A is reduced. This allows the temperature of the refrigerant flowing into the second heat exchange section 101B in the midstream portion and the temperature of the refrigerant flowing into the third heat exchange section 101C in the downstream portion to be kept relatively low, thereby making it possible to uniformize the temperature of the multiple semiconductor elements 501 arranged along the refrigerant flow direction. Furthermore, in the cooler 1 of this embodiment, the inclination angle of the lower surface 201 can be changed depending on the number and layout of the heating elements 5 to be placed on the upper surface 200 of the top plate 2, so the water jacket 3 and corrugated fins 4 are highly versatile.

[0059] The lower surface 201 of the top plate 2 in the cooler 1 of this embodiment is not limited to the inclined surface in which the thickness of the top plate 2 continuously increases from upstream to downstream as illustrated in FIG. 18 . The lower surface 201 of the top plate 2 may be, for example, a stepped surface in which the thickness changes stepwise for each heat exchange section. Furthermore, the cooler 1 of this embodiment may have the lower surface 201 of the top plate 2 parallel to the upper surface 301 of the bottom plate 300, and the corrugated fins 4 disposed in the refrigerant flow path 100 may be formed such that the height from the lower end of the downward bent portion 430 to the upper end of the upward bent portion 420 (fin length) increases from the upstream end to the downstream end. In this example, the corrugated fins 4 are formed so that the length of the fins is slightly shorter than the distance from the lower surface of the bottom plate 300 to the lower surface 201 of the top plate 2 (flow path height) at the upstream end, and becomes longer than the flow path height toward the downstream end, with the difference from the flow path height becoming larger. After placing such corrugated fins 4 on the upper surface 301 of the bottom plate portion 300 of the water jacket 3, when a top plate 2 whose lower surface 201 is parallel to the upper surface 301 of the bottom plate portion 300 is attached to the water jacket 3, the contact area of ​​each upward bent portion 420 with the top plate 2 gradually increases from upstream to downstream. In a cooler 1 in which the lower surface 201 of the top plate 2 and the upper surface 301 of the bottom plate portion 300 are parallel, the height of the refrigerant flow path 100 is substantially constant from upstream to downstream, which can prevent uneven cooling performance due to, for example, different refrigerant flow rates between the upstream and downstream portions. Note that the upper bent portions 420 of the corrugated fins 4 and the lower surface 201 of the top plate 2 in the cooler 1 of this embodiment do not necessarily need to have a section where the upper bent portions 420 are separated from the lower surface 201, as shown in FIG. 19A .

[0060] [Fifth embodiment] 22A to 22C are cross-sectional views illustrating fins of a cooler according to a fifth embodiment. The cross-sectional view of FIG. 22A may be an enlarged view of a portion of the cooler 1 cut along the YZ plane at a position x1 (see FIG. 2) in the first heat exchange section 101A in the upstream portion. The cross-sectional view of FIG. 22B may be an enlarged view of a portion of the cooler 1 cut along the YZ plane at a position x2 (see FIG. 2) in the second heat exchange section 101B in the midstream portion. The cross-sectional view of FIG. 22C may be an enlarged view of a portion of the cooler 1 cut along the YZ plane at a position x3 (see FIG. 2) in the third heat exchange section 101C in the downstream portion.

[0061] As illustrated in FIGS. 22A to 22C, the cooler 1 of this embodiment has a plurality of plate-shaped fins 310 arranged in the refrigerant flow path 100 in the flow path width direction (Y direction) and integrally formed with the bottom plate portion 300. The plate-shaped fins 310 may include the plate-shaped portion 410 and the upwardly bent portion 420 of the corrugated fin 4 illustrated in the first to fourth embodiments, and each plate-shaped fin 310 is arranged parallel to the refrigerant flow direction (X direction). The water jacket 3 integrally formed with the plate-shaped fins 310 can be manufactured by, for example, casting or a method using a 3D printer. Note that a structure in which a plate-shaped fin member in which the plate-shaped fins 310 are joined to another bottom plate may be arranged on the bottom plate portion 300.

[0062] The first plate-like fins 310A in the first connection state are in thermal contact with the underside 201 of the top plate 2 over the entire area from the upstream end to the downstream end in the refrigerant flow direction (X direction). Therefore, heat exchange between the first plate-like fins 310A and the refrigerant occurs in all sections of the first heat exchange section 101A, the second heat exchange section 101B, and the third heat exchange section 101C.

[0063] The second plate-shaped fin 310B in the second contact state has a heat blocking region extending from its upstream end in the refrigerant flow direction to a position x4 (see FIG. 2) between the first heat exchange section 101A and the second heat exchange section 101B, and a heat contact region extending from the position x4 to the downstream end. The third plate-shaped fin 310C in the third contact state has a heat blocking region extending from its upstream end in the refrigerant flow direction to a position x5 (see FIG. 2) between the second heat exchange section 101B and the third heat exchange section 101C, and a heat contact region extending from the position x5 to the downstream end. The second plate-shaped fin 310B and the third plate-shaped fin 310C may have, for example, an inclined shape in which the upper surface of the heat blocking region is closer to the upstream end than the lower surface 201 of the top plate 2 (see the first embodiment), or may have a stepped shape in which the length of the fin changes at the boundary between the heat blocking region and the heat contact region (see the third embodiment). In the first heat exchange section 101A, heat exchange between the second plate fins 310B and the refrigerant and between the third plate fins 310C and the refrigerant does not substantially occur. Therefore, the refrigerant that flows along the heat exchange surfaces of the second plate fins 310B and the third plate fins 310C in the first heat exchange section 101A flows into the second heat exchange section 101B at a lower temperature than the refrigerant that flows along the heat exchange surfaces of the first plate fins 310A.

[0064] In the second heat exchange section 101B, heat exchange occurs between the first plate fins 310A and the refrigerant, and between the second plate fins 310B and the refrigerant. Because the temperature of the refrigerant flowing along the heat exchange surfaces of the second plate fins 310B is lower than that of the refrigerant flowing along the heat exchange surfaces of the first plate fins 310A, the temperature difference between the temperature of the heating element 5 in the first heat exchange section 101A and the temperature of the heating element 5 in the second heat exchange section 101B can be reduced, as described above. Similarly, in the third heat exchange section 101C, heat exchange occurs between the third plate fins 310 and a relatively low-temperature refrigerant flowing along the heat exchange surfaces of the third plate fins 310C. This reduces the temperature difference between the temperature of the heating element 5 in the second heat exchange section 101B and the temperature of the heating element 5 in the third heat exchange section 101C.

[0065] In the cooler 1 of this embodiment, all of the plate fins 310 may have a constant dimension (fin length) in the channel height direction (Z direction), and grooves 202 may be formed on the lower surface 201 of the top plate 2 at positions corresponding to the heat blocking regions of the second plate fin 310B and the third plate fin 310C (see the second embodiment). As described in the fourth embodiment, the lower surface 201 of the top plate 2 may be inclined, or the length of the plate fins 310 may be increased from upstream to downstream, so that the contact area per unit length in the refrigerant flow direction (X direction) increases from upstream to downstream. The plate fins 310 in the cooler 1 of this embodiment are not limited to having a flat heat exchange surface, and may have an uneven shape that generates turbulence in the refrigerant flowing along the heat exchange surface.

[0066] Furthermore, in the cooler 1 of this embodiment, multiple pin-shaped fins may be arranged in the refrigerant flow path 100 instead of the plate-shaped fins 310. When multiple pin-shaped fins are arranged, for example, a set of pin-shaped fins aligned in the refrigerant flow direction (X direction) is regarded as the plate-shaped fins 310, and by adjusting the number of pin-shaped fins in contact with the underside 201 of the top plate 2 for each set of pin-shaped fins, the contact area between the pin-shaped fins and the top plate 2 at each position in the refrigerant flow direction can be increased from upstream to downstream without changing the arrangement density of the pin-shaped fins between the upstream and downstream portions.

[0067] The cooler 1 according to the above-described embodiment is merely an example of the cooler 1 according to the present invention. The number of heat-generating elements 5 arranged on the top plate 2 of the cooler 1, the configuration of the heat-generating elements 5, and the like are not limited to those described above. Furthermore, the boundary between the heat-blocking region 422 and the heat-contact region 421 may be, for example, between adjacent semiconductor elements 501 in the refrigerant flow direction in one heat exchange section 101 (heat-generating elements 5). Specifically, the corrugated fins 4 in the cooler 1 illustrated in FIGS. 1 and 2 may have one or more of the following connection states in addition to the three connection states described above: a connection state in which the boundary between the heat-blocking region 422 and the heat-contact region 421 is at position x1; a connection state in which the boundary between the heat-blocking region 422 and the heat-contact region 421 is at position x2; and a connection state in which the boundary between the heat-blocking region 422 and the heat-contact region 421 is at position x3. The coolant inlet 110 and outlet 111 in the cooler 1 may be formed in, for example, the bottom plate 300 or the top plate 2. Furthermore, the coolant inlet 110 and outlet 111 may be formed at the ends of the frame 320 in the short side direction.

[0068] The use of the cooler 1 according to the above-described embodiment is not limited to a specific application, but is particularly suitable for cooling semiconductor modules that operate in high-temperature environments. A semiconductor module equipped with the cooler 1 according to the embodiment may be applied to a power conversion device such as an inverter device that drives a motor of a vehicle such as a four-wheeled automobile or a two-wheeled automobile, or a railway vehicle. A semiconductor module equipped with the cooler 1 according to the embodiment may also be applied to an industrial power conversion device such as an inverter device that drives a motor of an elevator, an escalator, or an air conditioning system for a building. The semiconductor module is not limited to an inverter device, and may also provide other functions.

[0069] The embodiments of the cooler and semiconductor module according to the present invention are not limited to the above-described embodiments, and may be variously changed, substituted, or modified without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way due to technological advances or other derived technologies, it may be implemented using that method. Therefore, the claims cover all embodiments that may fall within the scope of the technical idea.

[0070] The features of the above-described embodiment will be summarized below. The cooler of the above-mentioned embodiment comprises a top plate portion having a first surface facing the refrigerant flow path and a heat generating element disposed on the reverse side of the first surface, a bottom plate portion having a second surface opposite the first surface of the top plate portion, a plurality of fins disposed between the first surface of the top plate portion and the second surface of the bottom plate portion, and a frame portion provided between the top plate portion and the bottom plate portion and having a wall surface surrounding the plurality of fins, wherein the arrangement density of the fins in a first section of the refrigerant flow path is the same as the arrangement density of the fins in a second section downstream of the first section, and the contact area between the fins and the top plate portion in the first section is smaller than the contact area between the fins and the top plate portion in the second section.

[0071] In the cooler according to the above embodiment, the fins have a plurality of plate-shaped portions arranged in a direction perpendicular to the flow direction of the refrigerant in the refrigerant flow path, and each of the plurality of plate-shaped portions extends in the flow direction of the refrigerant, and some of the plurality of plate-shaped portions are spaced apart from the first surface of the top plate portion within the first section on the inlet side of a predetermined position between the upstream end on the inlet side of the refrigerant in the refrigerant flow path and the downstream end on the outlet side, and are connected to the first surface of the top plate portion within the second section downstream of the predetermined position.

[0072] In the cooler according to the above embodiment, the plurality of plate-shaped portions include a first plate-shaped portion whose entire area from the upstream end to the downstream end is connected to the first surface of the top plate portion, and a second plate-shaped portion that is spaced apart from the first surface of the top plate portion within the first section.

[0073] In the cooler according to the above embodiment, the second plate-shaped portion includes a plurality of plate-shaped portions having different lengths of regions spaced apart from the first surface of the top plate portion in the flow direction of the refrigerant.

[0074] In the cooler according to the above embodiment, the multiple fins are multiple plate-shaped portions of a corrugated fin formed by bending a plate-shaped heat conduction material into a wave shape, and the contact area between the fins and the top plate portion is the contact area between the bent portion connecting adjacent plate-shaped portions and the top plate portion.

[0075] In the cooler according to the above embodiment, the bending portion in contact with the top plate portion includes a first bending portion in contact with the top plate portion within the first section, and a second bending portion spaced apart from the top plate portion within the first section.

[0076] In the cooler according to the above embodiment, the distance of the second bent portion from the first surface of the top plate portion increases toward the upstream side within the first section.

[0077] In the cooler according to the above embodiment, the second bent portion has a step between the portion in the first section and the portion in the second section.

[0078] In the cooler according to the above embodiment, the second bending portion has a portion within the second section that is a convex curved surface facing the first surface of the top plate portion, and a portion within the first section that is a flat surface spaced apart from the first surface of the top plate portion.

[0079] In the cooler according to the above embodiment, the second bending portion has the same height from the second surface of the bottom plate portion from the upstream end to the downstream end, and a groove is formed on the first surface of the top plate portion that separates the top plate portion from the second bending portion within the first section.

[0080] In the cooler according to the above embodiment, the contact area of ​​the bent portion with the first surface of the top plate portion per unit length in the flow direction of the refrigerant increases from upstream to downstream.

[0081] In the cooler according to the above embodiment, the flow direction of the refrigerant is the longitudinal direction of the flow path of the refrigerant in a plan view of the first surface of the top plate portion.

[0082] The semiconductor module according to the above-described embodiment comprises a cooler according to the above-described embodiment and a heat generating element arranged on the reverse side of the first surface of the top plate portion of the cooler, and the heat generating element comprises a wiring board and a semiconductor element. [Industrial Applicability]

[0083] As described above, the present invention has the effect of making it possible to equalize the temperature of a heat-generating element along the direction of refrigerant flow in a cooler applied to a semiconductor module or the like, and is particularly useful for application to semiconductor modules that generate a large amount of heat during operation, such as those for industrial or electrical equipment use. [Explanation of symbols]

[0084] REFRIGERATION SUMMARY OF THE INVENTION 1...cooler, 100...refrigerant flow path, 101, 101A to 101C...heat exchange section, 110...inlet, 111...outlet, 2...top plate, 201...lower surface, 202, 202A, 202B...groove, 3...water jacket, 300...bottom plate portion, 301...upper surface, 310, 310A to 310C...plate-shaped fin, 320...frame portion, 4...corrugated fin, 410, 410A to 410C...plate-shaped portion, 411, 412...heat exchange surface, 420, 420A to 420C...upward bent portion, 421...heat contact area, 422...heat blocking area, 423, 423B, 423C...flat surface, 5, 5A to 5C...heat generating element, 500...wiring board, 501, 501A, 501B...semiconductor element, 7...semiconductor module

Claims

1. a top plate portion having a first surface facing a flow path of the refrigerant and a heating element disposed on a back surface of the first surface; a bottom plate portion having a second surface opposite to the first surface of the top plate portion; a plurality of fins disposed between the first surface of the top plate portion and the second surface of the bottom plate portion; a frame portion provided between the top plate portion and the bottom plate portion and having a wall surface surrounding the plurality of fins, The plurality of fins are the arrangement density of the fins in a first section of the coolant flow path is the same as the arrangement density of the fins in a second section downstream of the first section, the fins are disposed between the first surface of the top plate portion and the second surface of the bottom plate portion such that a contact area between the fins and the top plate portion in the first section is smaller than a contact area between the fins and the top plate portion in the second section. cooler.

2. the plurality of fins have a plurality of plate-like portions arranged in a direction perpendicular to a flow direction of the coolant in the coolant flow path, Each of the plurality of plate-shaped portions extends in a direction in which the refrigerant flows, some of the plurality of plate-shaped portions are spaced apart from the first surface of the top plate portion within the first section on the inlet side of a predetermined position between an upstream end of the inlet side of the refrigerant in the flow path of the refrigerant and a downstream end of the outlet side of the refrigerant, and are connected to the first surface of the top plate portion within the second section downstream of the predetermined position; The cooler of claim 1 .

3. 3. The cooler of claim 2, wherein the plurality of plate-shaped portions include a first plate-shaped portion whose entire area from the upstream end to the downstream end is connected to the first surface of the top plate portion, and a second plate-shaped portion that is spaced apart from the first surface of the top plate portion within the first section.

4. The cooler according to claim 3 , wherein the second plate-shaped portion includes a plurality of plate-shaped portions having different lengths of regions spaced from the first surface of the top plate portion in the flow direction of the refrigerant.

5. 2. The cooler of claim 1, wherein the plurality of fins are a plurality of plate-shaped portions of a corrugated fin formed by bending a plate-shaped heat conduction material into a wave shape, and the contact area between the fins and the top plate portion is the contact area between the bent portion connecting adjacent plate-shaped portions and the top plate portion.

6. The cooler of claim 5, wherein the bent portion in contact with the top plate portion includes a first bent portion in contact with the top plate portion within the first section and a second bent portion spaced apart from the top plate portion within the first section.

7. The cooler according to claim 6 , wherein the distance of the second bent portion from the first surface of the top plate portion increases toward the upstream side within the first section.

8. The cooler according to claim 6 , wherein the second bent portion has a step between a portion in the first section and a portion in the second section.

9. 9. The cooler according to claim 8, wherein the second bent portion has a portion within the second section that is a convex curved surface toward the first surface of the top plate portion, and a portion within the first section that is a flat surface spaced apart from the first surface of the top plate portion.

10. the second bent portion has a constant height from the second surface of the bottom plate portion from the upstream end to the downstream end, The cooler according to claim 6 , wherein a groove is formed in the first surface of the top plate portion, the groove separating the top plate portion from the second bent portion within the first section.

11. The cooler according to claim 5 , wherein the bent portion has a contact area with the first surface of the top plate portion per unit length in the flow direction of the refrigerant that increases from upstream to downstream.

12. The cooler according to claim 1 , wherein the flow direction of the refrigerant is a longitudinal direction of a flow path of the refrigerant in a plan view of the first surface of the top plate portion.

13. A cooler according to any one of claims 1 to 12; a heat generating element disposed on a back surface of the first surface of the top plate portion of the cooler, The heat generating element includes a wiring board and a semiconductor element.

Images