Coolers, semiconductor devices, and vehicles

Abstract

In the present invention, the cooling performance of a cooler applied to a semiconductor device is improved. A cooler (2) comprises: a top plate on a first surface of which a heat-dissipating surface is formed; a bottom plate that is disposed facing the top plate and that has a greater thickness than that of the top plate; a plurality of fins (210) connected to at least the top plate; and a peripheral wall part formed, between the top plate and the bottom plate, so as to surround the outer periphery of the plurality of fins. A refrigerant flow path (260) surrounded by the top plate, the bottom plate, and the peripheral wall part is formed, the refrigerant flow path having a refrigerant inflow port (251) provided toward one end in a first direction of the refrigerant flow path and a refrigerant outflow port (252) provided toward the other end thereof in the first direction. The plurality of fins each include an inclined portion that, in a first plan view when viewed from a second direction perpendicular to the first direction, extends in a direction of displacement toward the refrigerant inflow port as the distance from the first surface of the top plate increases and that, in a second plan view when viewed from the first direction, extends in a direction of displacement in the second direction as the distance from the first surface of the top plate increases.

Description

Technical Field

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[0001] The present invention relates to a cooler, a semiconductor device, and a vehicle.

Background Art

[0002] Some semiconductor devices used in power conversion devices such as inverter devices include a cooler that circulates a refrigerant for dissipating heat generated by semiconductor elements. This type of cooler has a plurality of fins provided in a flow path for circulating the refrigerant (for example, Patent Documents 1 to 5).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described semiconductor device, improvement of the cooling performance of the cooler is desired.

[0005] The present invention has been made in view of such points, and one object thereof is to improve the cooling performance of a cooler applied to a semiconductor device.

Means for Solving the Problems

[0006] A cooler according to one aspect of the present invention comprises a top plate having a heat dissipation surface formed on its first surface, a bottom plate positioned opposite the top plate and having a greater thickness than the top plate, a plurality of fins connected to at least the top plate, and a peripheral wall portion formed between the top plate and the bottom plate so as to surround the outer circumference of the plurality of fins, wherein a coolant flow path is formed by the space enclosed by the top plate, the bottom plate, the plurality of fins, and the peripheral wall portion, and provided on the top plate, the bottom plate, or the peripheral wall portion at one end of the coolant flow path in the first direction The refrigerant inlet, the refrigerant outlet provided on the top plate, bottom plate, or peripheral wall at the other end of the first direction, and each of the plurality of fins include an inclined portion that, in a first plan view when viewed from a second direction perpendicular to the first direction, extends in a direction that displaces toward the refrigerant inlet as it moves away from the first surface of the top plate, and in a second plan view when viewed from the first direction, extends in a direction that displaces toward the second direction as it moves away from the first surface of the top plate. [Effects of the Invention]

[0007] According to the present invention, the cooling performance of a cooler applied to a semiconductor device can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a top view showing an example of the configuration of a semiconductor device according to one embodiment. [Figure 2] Figure 1 is an enlarged top view showing the configuration of one circuit formation section in the semiconductor device. [Figure 3] This is a cross-sectional side view showing an example of the configuration of a semiconductor device cut along the line A-A' in Figure 1. [Figure 4] This is a cross-sectional side view showing an example of the configuration of a semiconductor device cut along the line B-B' in Figure 1. [Figure 5] This figure shows an example of a circuit configuration for an inverter device using the semiconductor device shown in Figure 1. [Figure 6] This is a bottom view illustrating a specific example of fins in a cooler according to one embodiment. [Figure 7]It is a diagram for explaining the first characteristic of the refrigerant flow in the cooler according to an embodiment. [Figure 8] It is a diagram for explaining the second characteristic of the refrigerant flow in the cooler according to an embodiment. [Figure 9] It is a graph diagram exemplifying the relationship between the angle in the extending direction of the fins, the thermal resistance value, and the pressure loss. [Figure 10] It is a diagram for supplementing the angle and arrangement in the extending direction of the fins. [Figure 11] It is a cross-sectional side view for explaining the first modification example of the configuration of the cooler. [Figure 12] It is a cross-sectional side view for explaining the first modification example of the fin arrangement. [Figure 13] It is a cross-sectional side view for explaining the second modification example of the fin arrangement. [Figure 14] It is a cross-sectional side view for explaining the third modification example of the fin arrangement. [Figure 15] It is a cross-sectional side view showing the second modification example of the configuration of the cooler. [Figure 16] It is a cross-sectional side view showing the third modification example of the configuration of the cooler. [Figure 17] It is a cross-sectional side view showing the fourth modification example of the configuration of the cooler. [Figure 18] It is a diagram for explaining the fifth modification example of the configuration of the cooler. [Figure 19] It is a diagram for explaining the sixth modification example of the configuration of the cooler. [Figure 20] It is a bottom view for explaining a modification example of the positional relationship between the refrigerant inlet and outlet in the cooler. [Figure 21] It is a cross-sectional side view showing the first modification example of the configuration of the cooler and the positional relationship between the refrigerant inlet and outlet. [Figure 22] It is a cross-sectional side view showing the second modification example of the configuration of the cooler and the positional relationship between the refrigerant inlet and outlet. [Figure 23] It is a cross-sectional side view showing the third modification example of the configuration of the cooler and the positional relationship between the refrigerant inlet and outlet. [Figure 24]This is a schematic plan view showing an example of a vehicle to which the semiconductor device according to the present invention is applied. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described in detail below with reference to the drawings. The X, Y, and Z axes in the referenced drawings are shown for the purpose of defining planes and directions in the example semiconductor devices, coolers, etc. The X, Y, and Z axes are orthogonal to each other and form a right-handed system. In the following description, the direction parallel to the X axis will be called the X direction, the direction parallel to the Y axis will be called the Y direction, and the direction parallel to the Z axis will be called the Z direction. Furthermore, when relating the X, Y, and Z directions to the directions of the arrows (positive and negative) on the X, Y, and Z axes shown in the drawings, they will be labeled as "positive side" or "negative side."

[0010] In this specification, the Z direction may be referred to as the up and down direction. In this specification, "up" or "above" means the positive Z direction relative to a reference surface, member, position, etc., and "down" or "below" means the negative Z direction relative to a reference surface, member, position, etc. For example, when it is stated that "member B is placed on member A," member B is placed on the positive Z direction relative to member A. Also, when it is stated that "the top surface of member A," that surface is located at the positive Z end of member A and faces the positive Z direction. In this specification, "top view" means a plan view of the article in question (e.g., semiconductor device, cooler, etc.) when viewed from the positive Z direction, and "bottom view" means a plan view of the article in question when viewed from the negative Z direction. In this specification, "front view" means a plan view of the article in question when viewed from the negative Y direction. In this specification, "side view" refers to a plan view of the article in question when viewed from the negative or positive X-direction. A plan view from the negative X-direction is sometimes called a "left side view," and a plan view from the positive X-direction is sometimes called a "right side view." These directions and surfaces are terms used for convenience of explanation, and their correspondence with the X, Y, and Z axes may change depending on the mounting orientation of the semiconductor device. For example, the surface on which the wiring board and semiconductor elements are arranged in a cooler is referred to as the top surface of the cooler in this specification, but it may also be called the bottom surface, side, etc. Furthermore, the aspect ratios and relative sizes of the components in each figure are represented schematically and do not necessarily correspond to the relationships in semiconductor devices and coolers that are actually manufactured. For convenience of explanation, it is possible that the relative sizes of the components may be exaggerated.

[0011] Furthermore, the semiconductor devices exemplified in the following description may be applied to power conversion devices such as inverter devices for industrial or electrical applications (e.g., automotive motors). For this reason, detailed descriptions of configurations, functions, operations, manufacturing methods, etc., that are identical or similar to those of known semiconductor devices will be omitted in the following description.

[0012] Figure 1 is a top view showing an example of the configuration of a semiconductor device according to one embodiment. Figure 2 is an enlarged top view of the configuration of one circuit formation section in the semiconductor device of Figure 1. Figure 3 is a cross-sectional side view showing an example of the configuration of a semiconductor device cut along the line A-A' in Figure 1. Figure 4 is a cross-sectional side view showing an example of the configuration of a semiconductor device cut along the line B-B' in Figure 1. The cross-sectional side view of Figure 3 shows a right side view of the portion to the left of the line A-A' in the semiconductor device cut along the line A-A' in Figure 1. The cross-sectional side view of Figure 4 shows a front view of the portion above the line B-B' in the semiconductor device cut along the line B-B' in Figure 1. Note that in Figures 2 and 3, the sealing material used to enclose semiconductor elements is omitted, and in Figure 4, the leads, case, sealing material, etc., are omitted.

[0013] The semiconductor device 1 illustrated in Figures 1 to 4 includes a cooler 2, a wiring board 3, semiconductor elements 4A and 4B, a case 5, wiring components 6A to 6F, and a sealing material 7.

[0014] The cooler 2 has a coolant flow path 260 for dissipating the heat generated by the semiconductor elements 4A and 4B of the semiconductor device 1, and is connected to a circulation circuit for circulating the coolant. The coolant flow path 260 in the cooler 2 is defined by a top plate 200, a bottom plate 230, and a peripheral wall portion 240. The top plate 200 has a roughly rectangular shape when viewed from above, and a plurality of fins 210 are arranged on its lower surface (heat dissipation surface) 202, extending downward from the lower surface 202. The peripheral wall portion 240 has a rectangular ring shape when viewed from above, surrounding the outer circumference of the plurality of fins 210, and is positioned below the top plate 200 so that its upper open end is covered by the top plate 200. The bottom plate 230 is positioned below the peripheral wall portion 240 so as to cover the lower open end of the peripheral wall portion 240. In the cooler 2, the relationship between the thickness T1 of the top plate 200 and the thickness T2 of the bottom plate 230, which is positioned opposite the top plate 200, may be T2 > T1, as illustrated in Figures 3 and 4. Also, the thickness T3 of the peripheral wall portion 240 may be T3 > T2.

[0015] The top plate 200, the peripheral wall portion 240, and the bottom plate 230 illustrated in Figures 3 and 4 are integrated such that the upper surface of the peripheral wall portion 240 is in close contact with the lower surface 202 of the top plate 200, and the lower surface of the peripheral wall portion 240 is in close contact with the upper surface 231 of the bottom plate 230. The method of integrating the top plate 200, the peripheral wall portion 240, and the bottom plate 230 is not limited to a specific method. In addition, in the cooler 2 illustrated in Figures 3 and 4, the peripheral wall portion 240 has an inlet 251 for introducing refrigerant into the refrigerant flow path 260 and an outlet 252 for discharging refrigerant from the refrigerant flow path 260. The outlet 252 may also be called an outlet for discharging refrigerant. A detailed explanation of the configuration of the cooler 2 will be given later.

[0016] The semiconductor device 1 illustrated in Figure 1 has three wiring boards 3 arranged on the top plate 200 of the cooler 2. The three wiring boards 3 have substantially the same configuration and include an insulating substrate 300, conductor patterns 301 to 303 provided on the upper surface of the insulating substrate 300, and a conductor pattern 304 provided on the lower surface of the insulating substrate 300. The wiring boards 3 may be, for example, DCB (Direct Copper Bonding) substrates or AMB (Active Metal Brazing) substrates. The wiring boards 3 may also be called laminated substrates, insulating circuit boards, etc.

[0017] The insulating substrate 300 is not limited to a specific substrate. The insulating substrate 300 may be a ceramic substrate formed from a ceramic material such as aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), or a composite material of aluminum oxide (Al2O3) and zirconium oxide (ZrO2). The insulating substrate 300 may also be, for example, a substrate molded from an insulating resin such as epoxy resin, a substrate impregnated with an insulating resin onto a base material such as glass fiber, or a substrate whose surface is coated with an insulating resin on a flat metal core.

[0018] The conductor pattern 304 provided on the lower surface of the insulating substrate 300 functions as a heat conductive member that conducts the heat generated by the semiconductor elements 4A and 4B to the cooler 2, and is formed of, for example, a metal plate or metal foil such as copper or aluminum. The conductor pattern 304 is joined to the upper surface 204 of the top plate 200 of the cooler 2 by a bonding material such as solder (not shown). The conductor pattern 304 may also be called a heat dissipation layer or heat dissipation pattern. The wiring board 3 may be arranged such that, for example, the conductor pattern 304 is joined to a base plate separate from the top plate 200, and heat is conducted to the top plate 200 via the base plate.

[0019] The conductor patterns 301 to 303 provided on the upper surface of the insulating substrate 300 function as wiring components and are formed from, for example, metal plates or metal foils such as copper or aluminum. The conductor patterns 301 to 303 provided on the upper surface of the insulating substrate 300 may also be called conductor layers, conductor plates, conductive layers, wiring patterns, etc. In the following description, when distinguishing between the conductor patterns 301 to 303, they will be referred to as the first conductor pattern 301, the second conductor pattern 302, and the third conductor pattern 303, respectively.

[0020] A semiconductor element 4A is positioned on the upper surface of the first conductor pattern 301. The first conductor pattern 301 is joined to the semiconductor element 4A by a first main electrode (not shown) provided on the lower surface of the semiconductor element 4A and a bonding material (not shown). The bonding material is a well-known bonding material such as solder. A semiconductor element 4B is positioned on the upper surface of the second conductor pattern 302. The second conductor pattern 302 is joined to the semiconductor element 4B by a first main electrode (not shown) provided on the lower surface of the semiconductor element 4B and a bonding material (not shown).

[0021] Each of the semiconductor elements 4A and 4B is composed of an RC (Reverse Conducting)-IGBT element, which integrates the functions of an IGBT (Insulated Gate Bipolar Transistor) element, which is a switching element, and a diode element such as an FWD (Free Wheeling Diode) element connected in antiparallel to the switching element. Each of these semiconductor elements 4A and 4B has a first main electrode on its lower surface and a second main electrode and a control electrode (gate electrode) on its upper surface. When the switching element of semiconductor elements 4A and 4B is an IGBT element, the first main electrode on the lower surface may be called the collector electrode, and the second main electrode on the upper surface may be called the emitter electrode.

[0022] The first main electrode provided on the lower surface of the semiconductor element 4A is electrically connected to the first main terminal 501 provided on the case 5 via the first conductor pattern 301. The first conductor pattern 301 and the first main terminal 501 are electrically connected by a well-known method. For example, the first conductor pattern 301 and the first main terminal 501 are electrically connected via a columnar or block-shaped wiring component (not shown) extending upward from the upper surface of the first conductor pattern 301. The second main electrode 401 provided on the upper surface of the semiconductor element 4A is electrically connected to the third main terminal 503 provided on the case 5 via a wiring component 6A and the second conductor pattern 302. The wiring component 6A is formed by bending a conductor plate such as a copper plate, and is called a lead, lead frame, etc. The wiring component 6A is joined to the second main electrode 401 and the second conductor pattern 302 of the semiconductor element 4A by a bonding material (not shown). In the example shown in Figure 2, the second conductor pattern 302 and the third main terminal 503 are electrically connected via a columnar conductive member (wiring component 6B) extending upward from the upper surface of the second conductor pattern 302. The second conductor pattern 302 and the third main terminal 503 may be electrically connected by another well-known method. The control electrode 402 provided on the upper surface of the semiconductor element 4A is electrically connected to the control terminal 504 provided on the case 5 by a bonding wire (wiring component 6E).

[0023] The first main electrode, located on the lower surface of the semiconductor element 4B, is electrically connected to the third main terminal 503 located on the case 5 via the second conductor pattern 302 and the wiring component 6B. The second main electrode 401, located on the upper surface of the semiconductor element 4B, is electrically connected to the second main terminal 502 located on the case 5 via the wiring component 6C and the third conductor pattern 303. The wiring component 6C is formed by bending a conductor plate such as a copper plate and is called a lead or lead frame. The wiring component 6C is joined to the second main electrode 401 and the third conductor pattern 303 of the semiconductor element 4B by a bonding material (not shown). In the example of Figure 2, the third conductor pattern 303 and the second main terminal 502 are electrically connected via a columnar conductive member (wiring component 6D) extending upward from the upper surface of the third conductor pattern 303. The control electrode 402, located on the upper surface of the semiconductor element 4B, is electrically connected to the control terminal 505 located on the case 5 by a bonding wire (wiring component 6F).

[0024] Case 5 includes an insulating member 500 having an open upper and lower end and a hollow portion 510 capable of accommodating the wiring board 3, semiconductor elements 4A and 4B, and wiring components 6A to 6F, etc., and the first main terminal 501, second main terminal 502, third main terminal 503, control terminal 504, and control terminal 505 described above. One end of each of the terminals of the first main terminal 501, second main terminal 502, third main terminal 503, control terminal 504, and control terminal 505 is exposed within the hollow portion 510 of the insulating member 500, and the other end protrudes from the upper surface of the insulating member 500. The portions of the first main terminal 501, second main terminal 502, and third main terminal 503 that protrude from the upper surface of the insulating member 500 are bent to conform to the upper surface of the insulating member 500. Recesses for fitting nuts 9 are formed in the areas overlapping with the first main terminal 501, the second main terminal 502, and the third main terminal 503 on the upper surface of the insulating member 500. The first main terminal 501, the second main terminal 502, and the third main terminal 503 each have through holes 521, 522, and 523, respectively, which correspond to the screw holes of the nuts 9 fitted into the recesses formed on the upper surface of the insulating member 500. The nuts 9 are used to screw bolts onto the first main terminal 501, the second main terminal 502, and the third main terminal 503, for example, to terminals of power supply cables such as wire harnesses, or to power supply components such as busbars.

[0025] The hollow portion 510 of case 5 is filled with a sealing material 7 that seals the wiring board 3, semiconductor elements 4A and 4B, and wiring components 6A to 6F, etc. The sealing material 7 is, for example, epoxy resin or silicone gel. The hollow portion 510 of case 5 may be formed as a single hollow portion without being divided for each wiring board 3 (i.e., not as three separate hollow portions), as illustrated in Figure 1.

[0026] Case 5 has through holes 511 formed at corners in a top view, as shown in Figure 2, for example. Case 5 is attached to the top plate 200 of the cooler 2 by, for example, inserting bolts 8 through the through holes 511 and screwing them into threaded holes formed in the top plate 200 of the cooler 2. The location and number of through holes 511 for attaching Case 5 to the top plate 200 are not limited to the locations and number exemplified in Figure 2. Furthermore, the method of attaching Case 5 to the top plate 200 is not limited to a specific method.

[0027] The semiconductor device 1 illustrated in Figure 1 includes three single-phase inverter circuits and can, for example, constitute a three-phase inverter device.

[0028] Figure 5 shows an example of a circuit configuration for an inverter device using the semiconductor device shown in Figure 1.

[0029] Figure 5 shows an example of a circuit configuration in a voltage-type three-phase inverter device as an example of an inverter device 11. The inverter device 11 includes three single-phase inverter circuits 1101(U), 1101(V), and 1101(W), a smoothing capacitor 1102, and a control circuit 1103. One single-phase inverter circuit includes one wiring board 3 and two semiconductor elements 4A and 4B. The single-phase inverter circuit 1101(U) converts DC to AC and outputs it as U-phase AC. The single-phase inverter circuit 1101(V) converts DC to AC and outputs it as V-phase AC. The single-phase inverter circuit 1101(W) converts DC to AC and outputs it as W-phase AC. In this specification, the three phases in three-phase AC are referred to as U-phase, V-phase, and W-phase, but other names may be used.

[0030] The inverter device 11 has three single-phase inverter circuits 1101(U), 1101(V), and 1101(W) connected in parallel with a smoothing capacitor 1102. The circuit configurations of the three single-phase inverter circuits 1101(U), 1101(V), and 1101(W), illustrated in the equivalent circuit in Figure 5, correspond to the circuits formed by one wiring board 3 and two semiconductor elements 4A and 4B in the semiconductor device 1, as described above with reference to Figures 2 and 3.

[0031] The inverter device 11 has a first input terminal IN(P) to which the positive terminal of the DC power supply 12 is connected, a second input terminal IN(N) to which the negative terminal of the DC power supply 12 is connected, and output terminals OUT(U), OUT(V), and OUT(W) to which three-phase AC is output.

[0032] Each of the single-phase inverter circuits 1101(U), 1101(V), and 1101(W) illustrated in Figure 5 is a half-bridge inverter circuit. In the single-phase inverter circuit 1101(U), the collector electrode of the switching element 410 (e.g., an IGBT element) in the semiconductor element 4A, which is connected between the first input terminal IN(P) and the output terminal OUT(U), sometimes called the upper arm, is connected to the first input terminal IN(P) via the first main terminal 501. In the single-phase inverter circuit 1101(U), the emitter electrode of the switching element 412 in the semiconductor element 4B, which is connected between the second input terminal IN(N) and the output terminal OUT(U), sometimes called the lower arm, is connected to the second input terminal IN(N) via the second main terminal 502. In the single-phase inverter circuit 1101(U), the emitter electrode of the upper arm switching element 410 and the collector electrode of the lower arm switching element 412 are connected via the third main terminal 503 to the output terminal OUT(U) which outputs the U-phase AC in the three-phase AC. Furthermore, a diode element 411 is connected in antiparallel to the upper arm switching element 410, and a diode element 413 is connected in antiparallel to the lower arm switching element 412. The other two single-phase inverter circuits 1101(V) and 1101( W ) respectively refers to the output terminal OUT(U) in the single-phase inverter circuit 1101(U) described above as output terminal OUT(V) and OUT( W This is a configuration that replaces the original structure with the following:

[0033] The alternating current output from each single-phase inverter circuit 1101(U), 1101(V), and 1101(W) is controlled so that its phase is shifted by 120 degrees from each other by control signals applied from the control circuit 1103 to the gate of the upper arm switching element 410 (control electrode 402 of semiconductor element 4A) via control terminal 504, and to the gate of the lower arm switching element 412 (control electrode 402 of semiconductor element 4B) via control terminal 505. An alternating current-operated load (for example, an AC motor) 13 is connected to the output terminals OUT(U), OUT(V), and OUT(W) of the inverter device 11.

[0034] The circuit configuration of the inverter device 11 including the semiconductor device 1 in this embodiment is not limited to the circuit configuration illustrated in Figure 5. Furthermore, the operation of the inverter device 11 including the semiconductor device 1 in this embodiment is not limited to a specific operation. For example, the inverter device 11 including the semiconductor device 1 may consist of three single-phase full-bridge inverter circuits connected in parallel.

[0035] Furthermore, referring to Figure 5, the inverter device 11 described above is merely an example of a device to which the semiconductor device 1 according to this embodiment is applied.

[0036] The switching elements 410 and 412 of semiconductor elements 4A and 4B are not limited to the IGBT elements described above, but may also be composed of, for example, power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), BJTs (Bipolar Junction Transistors), etc. When the switching elements are MOSFET elements, the main electrodes on the lower surface of semiconductor elements 4A and 4B may be called drain electrodes, and the main electrodes on the upper surface may be called source electrodes. Furthermore, the diode elements 411 and 413 may be composed of, for example, SBDs (Schottky Barrier Diodes), JBS (Junction Barrier Schottky) diodes, MPS (Merged PN Schottky) diodes, PN diodes, etc. In addition, the control electrodes 402 provided on the upper surface of semiconductor elements 4A and 4B may include gate electrodes and auxiliary electrodes. For example, the auxiliary electrodes may be auxiliary emitter electrodes or auxiliary source electrodes that are electrically connected to the main electrodes on the upper surface and serve as a reference potential for the gate potential. Furthermore, the auxiliary electrodes may be temperature-sensing electrodes that are electrically connected to a temperature-sensing unit, which may be included in the inverter device 11, etc., and measure the temperatures of the semiconductor elements 4A and 4B. These electrodes formed on the upper surfaces of the semiconductor elements 4A and 4B (the second main electrode 401, and the control electrode 402 including the gate electrode and auxiliary electrode) may collectively be called upper surface electrodes. In addition, the substrates on which the switching elements 410 and 412 and the diode elements 411 and 413 are formed are not limited to silicon substrates, but may be, for example, SiC (silicon carbide) substrates, GaN (gallium nitride) substrates, etc.

[0037] Furthermore, the switching element and diode element described as being included in a single semiconductor element in the single-phase inverter circuit described above with reference to Figure 5 may be provided by separate semiconductor elements. For example, the switching element 410 and diode element 411 of the upper arm may be provided by a semiconductor element on which the switching element 410 is formed and a semiconductor element on which the diode element 411 is formed. The shape, number, and placement of the semiconductor elements can be changed as appropriate. The layout of the conductor pattern as wiring components provided on the upper surface of the wiring board 3 can be changed according to the type, shape, number, and placement of the semiconductor elements.

[0038] The cooler 2 in the semiconductor device 1 according to this embodiment may have, for example, a top plate 200 with a plurality of fins 210 arranged on its lower surface 202, a bottom plate 230, and a peripheral wall portion 240, as described above with reference to Figures 3 and 4. In the cooler 2 illustrated in this embodiment, a refrigerant inlet 251 is provided on the left side in a top view (Figure 1) and a front view (Figure 4), and a refrigerant outlet 252 is provided on the right side. In other words, the refrigerant flow path 260 of the cooler 2, defined by the top plate 200, the bottom plate 230, and the peripheral wall portion 240, has its upstream end on the left side and its downstream end on the right side. The number of single-phase inverter circuits (sets of a wiring board 3 and semiconductor elements 4A and 4B) arranged on the top plate 200 of one cooler 2 is not limited to three. In addition, the top plate 200 may have the single-phase inverter circuits described above as well as circuits different from the single-phase inverter circuits.

[0039] Each of the multiple fins 210 is a columnar fin, sometimes called a pin fin, as will be described later with reference to Figure 6, and is arranged in a two-dimensional grid on the lower surface 202 of the top plate 200. The top plate 200 on which the multiple fins 210 are arranged is a component that dissipates heat conducted from the semiconductor elements 4A and 4B through the wiring board 3, and is formed of, for example, an aluminum alloy. In the cooler 2 of this embodiment, the extension direction of the fins 210 is non-parallel to the normal direction (Z direction) of the lower surface 202, both in a front view (Figure 4) and a side view (Figure 3). More specifically, each of the multiple fins 210 extends such that, in a front view (Figure 4), it is displaced upstream of the refrigerant flow path 260 as it moves away from the lower surface 202 of the top plate 200, and in a side view (Figure 3), it is displaced towards the horizontal end face of the refrigerant flow path 260 as it moves away from the lower surface 202 of the top plate 200 (in other words, the distance from the peripheral wall portion 240 changes). The acute angle θ1 in the extension direction of the fin 210 in a front view (hereinafter simply referred to as "angle θ1") and the acute angle θ2 in the extension direction of the fin 210 in a side view (hereinafter simply referred to as "angle θ2") may be the same value or may be different values.

[0040] Figure 6 is a bottom view illustrating a specific example of fins in a cooler according to one embodiment.

[0041] Each of the multiple fins 210 in the cooler 2 according to this embodiment has an inclined columnar shape, as shown in Figure 6, for example, and is arranged in a two-dimensional grid where the spacing between adjacent fins 210 at a 45-degree angle to the extension direction (X direction and Y direction) of the edges on the lower surface 202 of the top plate 200 is D1. In this specification, "inclined columnar shape" refers to a columnar shape in which the center P1 of the end face (first bottom surface) on the lower surface 202 side of the top plate 200 in the extension direction of the fin 210 and the center P2 of the end face (second bottom surface) furthest from the bottom surface 202 do not coincide in a plan view (bottom view).

[0042] Each of the multiple fins 210 illustrated in Figure 6 has a square first base (and second base), and is positioned such that the direction of extension of the edges on the first base is at a 45-degree angle to the direction of extension of the edges on the lower surface 202 of the top plate 200. In other words, the fins 210 are positioned such that the direction of extension of the edges on the first base is at a 45-degree angle to the direction (X-axis direction) from the refrigerant inlet 251 (upstream) to the refrigerant outlet 252 (downstream).

[0043] A top plate 200 having multiple fins 210, each inclined columnar, arranged in a two-dimensional grid, as illustrated in Figure 6, can be manufactured by applying well-known methods. For example, a top plate 200 having multiple fins 210, each inclined columnar, can be manufactured by cutting the surface of a metal material using multiple blades simultaneously. Alternatively, a top plate 200 having multiple fins 210, each inclined columnar, can be manufactured using a molding method called metal injection molding (MIM). Furthermore, a top plate 200 having multiple fins 210, each inclined columnar, can be manufactured using a 3D printer, for example. Note that the manufacturing method for a top plate 200 having multiple fins 210, each inclined columnar, is not limited to the methods described above.

[0044] The effects and benefits of applying the cooler 2 according to this embodiment will be explained with reference to Figures 7 to 10.

[0045] Figure 7 illustrates the first characteristic of the refrigerant flow in a cooler according to one embodiment. Figure 8 illustrates the second characteristic of the refrigerant flow in a cooler according to one embodiment. Figure 9 is a graph illustrating the relationship between the angle in the extension direction of the fins, the thermal resistance value, and the pressure loss. Figure 10 is a diagram to provide supplementary information regarding the angle and arrangement of the fins in the extension direction.

[0046] In the cooler 2 according to this embodiment, as shown in Figure 7, each of the multiple fins 210 extending downward from the lower surface 202 of the top plate 200 has an inclined columnar shape in which the part further away from the top plate 200 is displaced upstream of the refrigerant flow path 260. When the semiconductor device 1 according to this embodiment is operated, some of the heat generated by the semiconductor elements 4A and 4B placed on the top plate 200 is conducted to the top plate 200 of the cooler 2 via the wiring board 3, and is dissipated by heat exchange between the fins 210 and the refrigerant flowing through the flow path 260. Since the heat exchange between the fins 210 and the refrigerant is more active at positions closer to the heat source (heat-generating element), the temperature of the refrigerant flowing through the flow path 260 defined within the cooler 2 tends to be higher in the upper part closer to the heat source (heat-generating element) semiconductor elements 4A and 4B than in the lower part. When the temperature of the refrigerant in the upper part of the flow path 260 becomes high, the efficiency of heat exchange between the fins 210 and the refrigerant decreases, and the cooling performance deteriorates.

[0047] In contrast, each of the multiple fins 210 in the cooler 2 according to this embodiment has an inclined columnar shape, as described above, where the part further from the top plate 200 is displaced upstream. In other words, each of the multiple fins 210 has an inclined side surface, where the part closer to the lower surface 202 of the top plate 200 is displaced downstream. Therefore, as illustrated in Figure 7, a portion of the refrigerant flowing from upstream to downstream in the flow path 260 of the cooler 2 is guided to the upper part of the flow path 260 along the inclined side surface of the fin 210. Furthermore, each of the multiple fins 210 in the cooler 2 according to this embodiment has an inclined columnar shape, as illustrated in Figure 3, where, even in a side view, the extension direction of the fin 210 is tilted in a direction that is not parallel to the normal direction of the lower surface 202 of the top plate 200. Therefore, the refrigerant flowing from upstream to downstream in the flow path 260 of the cooler 2, specifically the portion near both ends in the horizontal direction in a side view (the left and right ends in the flow path 260 in Figure 3), can be guided to the central portion in the horizontal direction along the inclined side surface of the fins 210. This allows for mixing of the relatively low-temperature refrigerant flowing in the lower portion of the flow path 260 and the ends where heat conduction from the wiring board 3 is less likely, with the relatively high-temperature refrigerant in the upper portion of the flow path 260, thereby suppressing the rise in the temperature of the refrigerant in the upper portion of the flow path 260. As a result, the decrease in the efficiency of heat exchange between the fins 210 and the refrigerant in the upper portion of the flow path 260 can be effectively suppressed, improving cooling performance. Furthermore, the improved cooling performance makes it possible to reduce the contact area (dimension L1) between the wiring board 3 and the top plate 20 for conducting a predetermined amount of heat from the wiring board 3 to the cooler 2, enabling miniaturization of the wiring board 3 and the semiconductor device 1.

[0048] Furthermore, as shown in Figure 8, if the first bottom surface of the fin 210 is square and the direction of extension of the sides on the first bottom surface is inclined at 45 degrees with respect to the direction from upstream to downstream in the refrigerant flow path, the refrigerant flowing from upstream to downstream will repeatedly branch and merge along the inclined side surface of the fin 210, for example, as indicated by the arrows in Figure 8. This branching and merging of the refrigerant in a plan view (bottom view), along with the refrigerant stirring described above with reference to Figure 7, occurs in the refrigerant flowing through the flow path 260 of the cooler 2. For example, refrigerant stagnation along the downstream-facing side surface of the fin 210 is reduced, and the refrigerant whose temperature has risen due to heat exchange can be smoothly guided to the downstream outlet 252. In other words, the cooler 2 according to this embodiment can also reduce pressure loss by suppressing refrigerant stagnation.

[0049] An example of the effect of the cooler 2 according to this embodiment on cooling performance and pressure loss is shown in the graph in Figure 9. In the graph in Figure 9, the horizontal axis is the angle θ1 (in degrees) of the extension direction of the fin 210 in the ZX plane (front view). In the graph in Figure 9, the left vertical axis is the thermal resistance value (in arbitrary units) associated with cooling performance, and the right vertical axis is the pressure loss (in arbitrary units).

[0050] The graph in Figure 9 shows the thermal resistance and pressure loss when the angle θ1 in the extension direction of the fin 210 is set to 90 degrees, as one of the conventional examples. The thermal resistance and pressure loss in the graph in Figure 9 when the angle θ1 is set to 85 degrees, 75 degrees, and 60 degrees are examples of measurements taken when the arrangement spacing S, gap G, and height H (see Figure 10) of the fin 210 are the same as those of the fin with an angle θ1 of 90 degrees, and only the angle θ1 is changed.

[0051] As can be seen from the graph in Figure 9, by making the angle θ1 of the extension direction of the fins 210 with respect to the upstream direction (-X direction) of the flow path 260 in a front view less than 90 degrees, the thermal resistance and pressure loss are reduced compared to the conventional example. Although not shown in the graph in Figure 9, if the angle θ1 is less than 45 degrees, the inclination of the extension direction of the fins 210 with respect to the flow path 260 of the refrigerant increases, and for example, the effect of guiding the refrigerant from the lower part of the flow path 260 to the upper part is weakened. Also, if the angle θ1 is less than 45 degrees, the amount of displacement of the center P2 of the second bottom surface with respect to the center P1 of the first bottom surface, as described above (refer to Figure 6), increases, and for example, if the number of fins 210 remains the same as in the conventional example, the flow path 260 for accommodating the fins 210 becomes larger (i.e., the cooler 2 becomes larger). On the other hand, if the dimensions of the flow path 260 remain the same as in the conventional example, the efficiency of heat exchange decreases due to the reduction in the number of fins 210. Therefore, it is preferable that the angle θ1 of the extension direction of the fin 210 with respect to the direction toward the upstream of the flow path 260 in a front view be 45 degrees or more and less than 90 degrees. In particular, from the graph in Figure 9, it can be inferred that it is more preferable for the angle θ1 to be 60 degrees or more and 75 degrees or less.

[0052] Furthermore, as illustrated in Figure 10, if the spacing S and bottom dimensions are the same for the conventional fin (dotted line) with an angle θ1 of 90 degrees and the fin 210 (solid line) with an angle θ1 of less than 90 degrees, then the gap GT between the sides of the fins 210 with an angle θ1 of less than 90 degrees in the direction perpendicular to the sides will be shorter than the gap G in the direction parallel to the bottom surface 202 of the top plate 200. G (>GT). Therefore, by keeping the spacing S of the fins 210 and the dimensions of the bottom surface the same as in the conventional example where the angle θ1 is 90 degrees, and making the angle θ1 less than 90 degrees, the flow velocity of the refrigerant flowing from the lower part to the upper part of the flow path 260 along the inclined side surface of the fins 210 becomes faster, and the refrigerant in the lower part and the refrigerant in the upper part can be effectively mixed.

[0053] Furthermore, if the height H and bottom dimensions of a fin 210 with an angle θ1 of less than 90 degrees are the same as those of a conventional fin with an angle θ1 of 90 degrees, the side surface area will be larger when the angle θ1 is less than 90 degrees. Therefore, by keeping the height H and bottom dimensions of the fin 210 the same as those of the conventional fin with an angle θ1 of 90 degrees and setting the angle θ1 to less than 90 degrees, the heat exchange efficiency of a single fin 210 can be improved. Consequently, for example, if the spacing (number) of fins 210 is the same as in the conventional fin with an angle θ1 of 90 degrees, the cooling performance will improve. On the other hand, since the number of fins 210 required to achieve the same level of cooling performance as the conventional fin with an angle θ1 of 90 degrees can be reduced, it becomes easier to manufacture, for example, a top plate 200 with multiple fins 210 arranged on it. Furthermore, when manufacturing a top plate 200 with multiple fins 210 arranged on it using the metal powder injection molding method or 3D printer described above, reducing the number of fins 210 allows for a reduction in the amount of material required to manufacture the top plate 200, which is advantageous in reducing manufacturing costs.

[0054] Furthermore, the shape of the fins 210 in the cooler 2 according to the above-described embodiment is not limited to the inclined columnar shape with square first and second bottom surfaces as described above, as shown in Figures 6 and 8, but may be other shapes. For example, the first and second bottom surfaces of the fins 210 may be, for example, rhombic, other polygonal, circular, or oblong (elliptical). Also, the fins 210 may have an external shape in which the first and second bottom surfaces have different shapes, for example, the first bottom surface being circular and the second bottom surface being square. The fins 210 may also have an external shape in which the first and second bottom surfaces have the same shape but at least one of their orientation or dimensions is different. Specifically, the fin 210 may have an outer shape in which, for example, the first and second bottom surfaces are square and become thicker or thinner as it moves away from the bottom surface 202 of the top plate 200, or it may have an outer shape that is twisted around an axis passing through the center P1 of the first bottom surface and the center P2 of the second bottom surface. Furthermore, the fin 210 may have a portion that extends in the direction normal to the bottom surface 202 between the bottom surface 202 of the top plate 200 and the portion having the inclined columnar outer shape described above (inclined portion).

[0055] Figure 11 is a cross-sectional side view illustrating a first modified configuration of the cooler. Figure 11 shows a right-side view of the portion of the semiconductor device 1 to the left of line A-A' in Figure 1, which is cut along line A-A'. In the cooler 2 of the semiconductor device 1 illustrated in Figure 11, suppression members 271 and 272 are positioned at the corners of the refrigerant flow path 260, which is defined by the top plate 200, bottom plate 230, and peripheral wall portion 240, where stirring of the refrigerant by the fins 210 is less likely to occur in a side view, thereby suppressing the flow of refrigerant from upstream to downstream and promoting refrigerant stirring. In the refrigerant flow path 260 illustrated in Figure 11, the distance to the side of the fins 210 increases as it goes downwards, and if the suppression member 271 is not positioned, it is difficult for the refrigerant that has moved to the lower end along the left end to return to the central portion in the horizontal direction. Furthermore, in the refrigerant flow path 260 illustrated in Figure 11, the distance from the right end surface to the side surface of the fin 210 decreases as it goes downwards. If the suppression member 272 is not placed, the refrigerant flowing along the upper right corner of the flow path 260 will have difficulty moving downwards. Thus, if there are areas in the refrigerant flow path 260 where refrigerant stirring is difficult depending on the extension direction and arrangement of the fin 210 in a side view, the refrigerant stirring can be promoted by placing the suppression members 271 and 272. For example, the suppression member 271 placed at the lower left corner of the refrigerant flow path 260 illustrated in Figure 11 provides an inclined surface that displaces to the horizontal central part as it goes downwards, and can guide the refrigerant that has moved to the lower end along the left side surface to the horizontal central part. Furthermore, the suppression member 272 positioned at the upper right corner of the refrigerant flow path 260, as illustrated in Figure 11, provides an inclined surface that contacts the lower surface 202 of the top plate 200 at an obtuse angle. This suppresses the accumulation of refrigerant in the upper right corner as it moves along the lower surface 202 towards the right end surface, thereby guiding the refrigerant to the lower end of the flow path.

[0056] Furthermore, the angles θ3 and θ4 of the inclined surfaces of the suppression members 271 and 272, as seen from the side, are not limited to specific angles. The angles θ3 and θ4 of the inclined surfaces of the suppression members 271 and 272 may differ from the angle θ2 in the extension direction of the fin 210, as illustrated in Figure 11. Also, the cross-sectional shape of the suppression members 271 and 272 as seen from the side is not limited to the triangle illustrated in Figure 11. Moreover, other suppression members besides the suppression members 271 and 272 illustrated in Figure 11 may be arranged in the refrigerant flow path 260. Instead of arranging the suppression members 271 and 272, for example, the shape of any of the top plate 200, bottom plate 230, and peripheral wall portion 240 to define the refrigerant flow path 260 may be made to have an inclined surface corresponding to the inclined surface provided by the suppression members 271 and 272.

[0057] Figure 12 is a cross-sectional side view illustrating a first modified example of the fin arrangement. Figure 13 is a cross-sectional side view illustrating a second modified example of the fin arrangement. Figure 14 is a cross-sectional side view illustrating a third modified example of the fin arrangement. Note that Figures 12 to 14 omit some of the illustrations of the components placed on the top plate 200, and the hatching indicating cross-sections of the components has also been omitted.

[0058] In the cooler 2 according to the above-described embodiment, the multiple fins 210 may all be of the same single shape, or they may include two or more different shapes. For example, Figure 12 shows an example in which two types of fins 210 with different dimensions of the first bottom surface (and second bottom surface) are arranged on the lower surface 202 of the top plate 200. In the four fins 210 illustrated in Figure 12, the first bottom surface is square, and the dimension D1 of the two fins 210 arranged at both ends in the horizontal direction is larger than the dimension D2 of the two fins 210 arranged in the central part in the horizontal direction. In this way, by increasing the dimensions (thickening) of the fins 210 arranged on both sides in the horizontal direction in a side view, the area of ​​the inclined side surface is increased, making it easier to guide the refrigerant flowing near the horizontal end in the refrigerant flow path 260 in a side view to the central part in the horizontal direction.

[0059] Furthermore, as shown in Figure 13, for example, there may be two directions in which the fins 210 extend when viewed from the side. Of the four fins 210 illustrated in Figure 13, the two fins 210 to the left of the horizontal center extend at an angle θ2 in a direction that approaches the left end face of the flow path 260 as they go downwards, and the two fins 210 to the right of the horizontal center extend at an angle θ2 in a direction that approaches the right end face of the flow path 260 as they go downwards. By arranging the fins 210 so that they taper from the lower part to the upper part of the refrigerant flow path 260 when viewed from the side, the refrigerant flowing at the horizontal end of the lower part of the refrigerant flow path 260 can be evenly guided to the upper part when viewed from the side. This makes it possible to suppress the uneven distribution of the refrigerant temperature when viewed from the side. Furthermore, when arranging the fins 210 as described above with reference to Figure 13, for example, a suppression member 273, separate from the fins 210, may be placed on the upper surface 231 of the bottom plate 230 to suppress the flow of refrigerant downstream and guide the refrigerant to the upper layer.

[0060] Furthermore, as shown in Figure 14, for example, there may be two or more directions of extension for the fins 210 in a front view. Of the six fins 210 illustrated in Figure 14, the extension angle θ11 of the three upstream fins 210 is smaller than the extension angle θ12 of the three downstream fins 210. As described above with reference to Figure 9, the thermal resistance and pressure loss change depending on the extension angle of the fins 210. Based on the graph in Figure 9, for example, if the extension angle θ11 of the three upstream fins 210 in a front view is 75 degrees and the extension angle θ12 of the three downstream fins 210 is 85 degrees, the thermal resistance and pressure loss on the upstream side will be smaller than those on the downstream side. For this reason, in the cooler 2 illustrated in Figure 14, for example, the refrigerant is more likely to flow from upstream to downstream on the upstream side of the flow path 260 than on the downstream side. Therefore, for example, the temperature rise of the refrigerant due to heat exchange between the fins 210 and the refrigerant upstream of the flow path 260 can be kept low, and the decrease in cooling efficiency downstream can be suppressed.

[0061] The cooler 2 according to this embodiment is not limited to the configuration described above, and for example, the peripheral wall portion 240 may be integrated with either the top plate 200 or the bottom plate 230.

[0062] Figure 15 is a cross-sectional side view illustrating a second modified example of the cooler configuration. Figure 16 is a cross-sectional side view illustrating a third modified example of the cooler configuration. Figure 17 is a cross-sectional side view illustrating a fourth modified example of the cooler configuration. All of these correspond to Figure 4.

[0063] As shown in Figure 15, the periphery wall portion 240 of the cooler 2 may be formed integrally with the bottom plate 230, or as shown in Figure 16, the periphery wall portion 240 may be formed integrally with the top plate 200. Although not shown, the cooler 2 may also have a periphery wall portion 240 in which a portion is formed integrally with the bottom plate 230, and the remaining portion of the periphery wall portion 240 is formed integrally with the top plate 200. Furthermore, as shown in Figure 17, the cooler 2 may have a top plate 200, bottom plate 230, and periphery wall portion 240 as an integral unit, and the cavity formed by these may serve as a coolant flow path 260. Such a cooler 2 can be manufactured, for example, using a 3D printer.

[0064] In the cooler 2 according to this embodiment, the multiple fins 210 may have their upper ends connected to the lower surface 202 of the top plate 200 and their lower ends connected to the upper surface of the bottom plate 230.

[0065] Figure 18 illustrates a fifth modified configuration of the cooler. Figure 19 illustrates a sixth modified configuration of the cooler. Figures 18 and 19 correspond to a portion of the cooler 2 illustrated in Figure 4, including the left end. In Figures 18 and 19, the underlined reference numeral 210 is intended to refer to the entire fin.

[0066] In the cooler 2 shown in Figure 18, the height H of the fins 210 extending downward from the lower surface 202 of the top plate 200 is approximately equal to the thickness T3 of the peripheral wall portion 240. Therefore, when the top plate 200, the peripheral wall portion 240, and the bottom plate 230 are integrated, the lower surface 211 of the fins 210 contacts the upper surface 231 of the bottom plate 230. In the cooler 2 shown in Figure 19, the multiple fins 210 extend upward from the upper surface 231 of the bottom plate 230, rather than from the lower surface 202 of the top plate 200. When multiple fins 210 are formed on the upper surface 231 of the bottom plate 230, the fins 210 are formed so that, in a front view, the parts of the fins 210 that are further from the upper surface 231 of the bottom plate 230 are displaced downstream. The height from the upper surface 231 of the bottom plate 230 to the upper surface 212 of the fins 210 is approximately equal to the thickness T3 of the peripheral wall portion 240. In Figure 19, the position of the upper surface 212 of the fin 210 in the Z direction is lower than the position of the upper surface 241 of the peripheral wall portion 240 in the Z direction. In such a cooler 2, for example, when integrating the top plate 200, the peripheral wall portion 240, and the bottom plate 230 on which the fins 210 are formed, the upper surface 212 of the fin 210 and the lower surface 202 of the top plate 200 are connected via a member 280 with high thermal conductivity.

[0067] Note: Finn 2 10 The configuration of the cooler 2, in which the upper end is connected to the lower surface 202 of the top plate 200 and the lower end is connected to the upper surface 231 of the bottom plate 230, is not limited to the configuration illustrated in Figures 18 and 19. For example, the lower surface 211 of the fin 210 extending downward from the lower surface 202 of the top plate 200 and the upper surface 231 of the bottom plate 230 may be connected via a member 280 with high thermal conductivity. Alternatively, for example, the upper surface 212 of the fin 210 extending upward from the upper surface 231 of the bottom plate 230 and the lower surface 202 of the top plate 200 may be in direct contact without the member 280.

[0068] Figure 20 is a bottom view illustrating a modified example of the positional relationship between the refrigerant inlet and outlet in a cooler.

[0069] The cooler 2 illustrated in Figures 4 and 14-19 has a refrigerant inlet 251 on its left end face in a front view and a refrigerant outlet 252 on its right end face. However, the positions of the refrigerant inlet 251 and outlet 252 in the cooler 2 according to the present invention are not limited to such positions. For example, as shown in Figure 20, the cooler 2 may have the refrigerant inlet 251 and outlet 252 positioned diagonally opposite each other in a plan view (bottom view) of the region where the refrigerant flow path 260 is defined, with a region 213 on either side of where multiple fins 210 are arranged.

[0070] Similarly, the inlet 251 and outlet 252 may be located on the side, bottom, or top, regardless of the configuration of the top plate 200, bottom plate 230, and peripheral wall portion 240, and one may be on the side and the other on either the top or bottom, or one may be on the top and the other on the bottom.

[0071] Figure 21 is a cross-sectional side view showing a first modified example of the cooler configuration and the positional relationship between the refrigerant inlet and outlet. Figure 22 is a cross-sectional side view showing a second modified example of the cooler configuration and the positional relationship between the refrigerant inlet and outlet. Figure 23 is a cross-sectional side view showing a third modified example of the cooler configuration and the positional relationship between the refrigerant inlet and outlet. All of these correspond to Figure 4.

[0072] In the cooler 2 shown in Figure 21, the peripheral wall portion 240 is integrated with the bottom plate 230, and the inlet 251 and outlet 252 are formed in the top plate 200 as through holes that penetrate from the upper surface 204 to the lower surface 202 of the top plate 200. In the cooler 2 shown in Figure 22, the peripheral wall portion 240 is integrated with the top plate 200, and the inlet 251 and outlet 252 are formed in the bottom plate 230 as through holes that penetrate from the upper surface 231 to the lower surface 232 of the bottom plate 230. In the cooler 2 shown in Figure 23, the peripheral wall portion 240 is integrated with the top plate 200, and the inlet 251 and outlet 252 are formed in the top plate 200 as through holes that penetrate from the upper surface 204 to the lower surface 202 of the top plate 200. As mentioned above, the positional relationship between the inlet 251 and the outlet 252 may be in other positions. For example, the cooler 2 may have an inlet 251 formed in the top plate 200 and an outlet 252 formed in the bottom plate 230 or the peripheral wall portion 240.

[0073] The semiconductor device 1 of the above-described embodiment is not limited to a specific application, but is particularly suitable for use in high-temperature environments. For example, the semiconductor device 1 of the above-described embodiment can be applied to power conversion devices such as inverter devices for in-vehicle motors. A vehicle to which the semiconductor device 1 according to the present invention is applied will be described with reference to Figure 24.

[0074] Figure 24 is a schematic plan view showing an example of a vehicle to which the semiconductor device according to the present invention is applied. The vehicle 1001 shown in Figure 24 is composed of, for example, four wheels 1002. The vehicle 1001 may be, for example, an electric vehicle that drives the wheels with a motor or the like, or a hybrid vehicle that uses the power of an internal combustion engine in addition to a motor. Furthermore, the vehicle to which the semiconductor device 1 is applied is not limited to a four-wheeled vehicle, but may also be a two-wheeled vehicle, a railway vehicle, or the like.

[0075] The vehicle 1001 includes a drive unit 1003 that provides power to the wheels 1002, and a control device 1004 that controls the drive unit 1003. The drive unit 1003 may consist of, for example, at least one of an engine, a motor, or a hybrid of an engine and a motor.

[0076] The control device 1004 performs control (e.g., power control) of the drive unit 1003. The control device 1004 includes a semiconductor device 1 which includes the cooler 2 of the embodiment described above. The semiconductor device 1 may be configured to perform power control to the drive unit 1003.

[0077] The embodiments of the cooler 2 and semiconductor device 1 according to the present invention are not limited to the embodiments described above, and may be modified, substituted, or transformed in various ways without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way by advances in the art or by other derived technologies, it may be implemented by that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical idea.

[0078] The following summarizes the key features of the embodiment described above.

[0079] The cooler according to the above-described embodiment comprises a top plate having a heat dissipation surface formed on its first surface, a bottom plate positioned opposite the top plate and having a greater thickness than the top plate, a plurality of fins connected to at least the top plate, and a peripheral wall portion formed between the top plate and the bottom plate so as to surround the outer circumference of the plurality of fins, wherein a refrigerant flow path is formed by the space enclosed by the top plate, the bottom plate, the plurality of fins, and the peripheral wall portion, and provided on the top plate, the bottom plate, or the peripheral wall portion at one end of the refrigerant flow path in the first direction The apparatus has a refrigerant inlet and a refrigerant outlet provided on the top plate, bottom plate, or peripheral wall at the other end of the first direction, and each of the plurality of fins includes an inclined portion that, in a first plan view when viewed from a second direction perpendicular to the first direction, extends in a direction that displaces toward the refrigerant inlet as it moves away from the first surface of the top plate, and in a second plan view when viewed from the first direction, extends in a direction that displaces toward the second direction as it moves away from the first surface of the top plate.

[0080] In the cooler according to the above embodiment, the angle of the inclined portion of the fin in the extension direction with respect to the first surface of the top plate in the first plan view is 45 degrees or more and less than 90 degrees, and the angle of the angle of the top plate in the extension direction with respect to the first surface in the second plan view is 45 degrees or more and less than 90 degrees.

[0081] In the cooler according to the above embodiment, the flow path of the refrigerant is configured to suppress the flow of the refrigerant in the first direction and promote the stirring of the refrigerant.

[0082] The cooler according to the above embodiment further comprises a suppression member, which is arranged in the flow path of the refrigerant and suppresses the flow of the refrigerant in the first direction, apart from the plurality of fins.

[0083] In the cooler according to the above embodiment, each of the plurality of fins is arranged such that the shape of the bottom surface in a plan view of the first surface of the top plate is square, and the direction in which the sides of the square extend is at a 45-degree angle with respect to the first direction.

[0084] In the cooler according to the above embodiment, the plurality of fins include a plurality of types of fins with different dimensions of the bottom surface in a plan view of the first surface of the top plate.

[0085] In the cooler according to the above embodiment, the dimensions of the fins located at the ends in the second direction are larger than the dimensions of the fins located in the central portion in the second direction.

[0086] In the cooler according to the above embodiment, the plurality of fins include a plurality of types of fins in which the combination of the extension direction of the inclined portion in the first plan view and the extension direction of the inclined portion in the second plan view is different.

[0087] In the cooler according to the above embodiment, the plurality of fins include, in the second plan view, fins that are displaced to one end in the second direction as the inclined portion moves away from the top plate, and fins that are displaced to the other end in the second direction.

[0088] In the cooler according to the above embodiment, the extension direction of the inclined portion of the plurality of fins changes depending on the distance from the upstream side of the refrigerant in the first plan view.

[0089] The semiconductor device according to the above-described embodiment comprises the cooler, and a wiring board and semiconductor elements arranged on the side of the top plate opposite to the first surface.

[0090] The vehicle according to the above-described embodiment is equipped with the above-described semiconductor device. [Industrial applicability]

[0091] As described above, the present invention has the effect of improving the cooling performance of coolers applied to semiconductor devices, and is particularly useful for industrial or electrical semiconductor devices and vehicles.

[0092] This application is based on Japanese Patent Application No. 2023-100938, filed on June 20, 2023. All of its contents are included here.

Claims

1. A top plate having a heat dissipation surface formed on the first surface, The system comprises a bottom plate positioned opposite the top plate and having a greater thickness than the top plate, a plurality of fins connected to at least the top plate, and a peripheral wall formed between the top plate and the bottom plate so as to surround the outer circumference of the plurality of fins, A refrigerant flow path is formed in the space enclosed by the top plate, the bottom plate, the plurality of fins, and the peripheral wall portion. The refrigerant flow path has a refrigerant inlet provided on the top plate, bottom plate, or peripheral wall at one end in the first direction, and a refrigerant outlet provided on the top plate, bottom plate, or peripheral wall at the other end in the first direction, Each of the plurality of fins includes an inclined portion that, in a first plan view when viewed from a second direction perpendicular to the first direction, extends in a direction that displaces toward the refrigerant inlet as it moves away from the first surface of the top plate, and in a second plan view when viewed from the first direction, extends in a direction that displaces toward the second direction as it moves away from the first surface of the top plate. cooler.

2. The cooler according to claim 1, wherein the angle of the inclined portion of the fin in the extension direction with respect to the first surface of the top plate in the first plan view is 45 degrees or more and less than 90 degrees, and the angle of the extension direction with respect to the first surface of the top plate in the second plan view is 45 degrees or more and less than 90 degrees.

3. The cooler according to claim 1, wherein the flow path for the refrigerant is configured to suppress the flow of the refrigerant in the first direction and promote the stirring of the refrigerant.

4. The cooler according to claim 3, further comprising a suppressing member, which is arranged in the flow path of the refrigerant and suppresses the flow of the refrigerant in a first direction, apart from the plurality of fins.

5. The cooler according to claim 1, wherein each of the plurality of fins is arranged such that the shape of the bottom surface of the first surface of the top plate in a plan view is square, and the direction in which the sides of the square extend is at a 45-degree angle with respect to the first direction.

6. The cooler according to claim 1, wherein the plurality of fins include a plurality of types of fins with different dimensions of the bottom surface in a plan view of the first surface of the top plate.

7. The cooler according to claim 6, wherein the dimensions of the fins located at the end in the second direction are greater than the dimensions of the fins located in the central portion in the second direction.

8. The cooler according to claim 1, wherein the plurality of fins include a plurality of types of fins with different combinations of the extension direction of the inclined portion in the first plan view and the extension direction of the inclined portion in the second plan view.

9. The cooler according to claim 1, wherein the plurality of fins include, in the second plan view, fins that are displaced to one end in the second direction as the inclined portion moves away from the top plate, and fins that are displaced to the other end in the second direction.

10. The cooler according to claim 1, wherein the extension direction of the inclined portion of the plurality of fins changes in the first plan view according to the distance from the upstream side of the refrigerant.

11. A semiconductor device comprising a cooler according to any one of claims 1 to 10, and a wiring board and a semiconductor element disposed on the side of the top plate opposite to the first surface.

12. A vehicle comprising the semiconductor device described in claim 11.

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