Cooling device and power converter

Abstract

In a cooling system, pressure loss is suppressed while improving the cooling performance on the downstream side. [Solution] The device comprises an inlet 10, an outlet 11, and a flow path through which the refrigerant flows. It is formed in a substantially rectangular parallelepiped shape by a top surface 6, a bottom surface 7, first and second side surfaces 2 and 3 formed parallel to the direction of refrigerant flow, and third and fourth side surfaces 4 and 5 formed perpendicular to the direction of flow. The top surface 6 and two or more heating elements 9 arranged in the direction of flow and two or more in the direction perpendicular to the direction of flow are cooled by the refrigerant. The flow path comprises a main flow path 14 formed between two heating elements 9 arranged perpendicular to the direction of flow, a first sub-flow path 15 formed between the heating element 9 and the first side surface 2, and a second sub-flow path 16 formed between the heating element 9 and the second side surface 3. A first fin region 17 is formed between the main flow path 14 and the first sub-flow path 15, and a second fin region 18 is formed between the main flow path 14 and the second sub-flow path 16.

Description

TECHNICAL FIELD

[0001] The present invention relates to a cooling device that cools a heating element with a refrigerant, and a power conversion apparatus including the cooling device.

BACKGROUND ART

[0002] Power conversion apparatuses provided with a cooling device have been conventionally known. Further, Patent Documents 1 to 3 are disclosed as power conversion apparatuses equipped with a cooling device.

[0003] A feature of Patent Document 1 is that, in a cooling device for a power module including a semiconductor chip, cooling fins and a loss adding portion are provided in a refrigerant flow portion formed between a top plate and a bottom plate. The loss adding portion is disposed between the cooling fins and an opening, and has a structure that intentionally generates pressure loss in the refrigerant passing therethrough.

[0004] Specifically, the loss adding portion is provided with mesh-shaped openings over the entire cross section of the refrigerant flow portion, and sets the pressure loss of the refrigerant to 5 kPa or more, thereby making the flow velocity distribution of the refrigerant in the refrigerant flow portion uniform. As a result, uniform cooling performance can be obtained over the entire cooling fins regardless of the arrangement of the openings, and the cooling efficiency of the semiconductor chip can be improved.

[0005] A feature of Patent Document 2 is that, in a liquid cooling device for cooling a heating element, the liquid cooling device includes a main flow path thermally connected to the heating element, and a sub flow path provided at a position separated from the main flow path, and a communication flow path that allows the refrigerant to flow therethrough is provided between the two flow paths.

[0006] With this configuration, a temperature rise can be suppressed even on the downstream side of the main flow path by supplying the refrigerant from the sub flow path, and the refrigerant is jetted from the sub flow path toward the heat transfer surface, so that the temperature boundary layer can be thinned to improve the heat transfer coefficient. As a result, the heating element can be uniformly cooled, the electrical characteristics and mechanical reliability of the heating element are improved, and high cooling characteristics can be obtained with a small refrigerant flow rate, so that the energy consumed for cooling can be reduced.

[0007] The features of Patent Document 3 are that, in a liquid cooling device for cooling multiple heat-generating elements, a main first flow path and a second flow path that branches off from and rejoins the first flow path are provided within a housing having a refrigerant inlet and outlet. The first flow path passes through a region in direct contact with the heat-generating elements, and the second flow path merges with the first flow path at a position downstream of the first heat-generating element and upstream of the second heat-generating element. The second flow path is also provided with a guide section that efficiently guides the refrigerant into the first flow path.

[0008] This configuration allows a cooler refrigerant, heated by the upstream heating element, to merge with a cooler refrigerant from the second channel. This prevents a decrease in cooling performance at the downstream heating element and suppresses variations in cooling temperature among multiple heating elements. Furthermore, by branching a third channel from the second channel, a similar effect can be obtained for heating elements further downstream. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2019-195031 [Patent Document 2] Japanese Patent Publication No. 2005-79337 [Patent Document 3] International release 2023 / 248989A1 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] In particular, inverters and DC / DC converters used in electric vehicle powertrains are designed for miniaturization, with multiple converters grouped together in one location and cooled intensively.

[0011] In this case, the pump that circulates the refrigerant also needs to be miniaturized, and pressure loss must be minimized as much as possible. Furthermore, if there are variations in the temperature of the semiconductor chips, unexpected current imbalances may occur, accelerating the degradation of the semiconductor chips and increasing unnecessary losses. Therefore, it is considered best to cool the entire power module uniformly.

[0012] For example, as described in Patent Document 1, it is conceivable to equalize the flow velocity at the inlet. However, in reality, the cooling effect decreases downstream as the refrigerant temperature rises, so in the case of a three-phase power module, it is not possible to cool the upper arm and lower arm, or the U phase and W phase, uniformly regardless of the flow direction (vertical or horizontal).

[0013] As a result, the junction temperature of the semiconductor chip located downstream becomes the highest, causing current imbalance, thus requiring a structure that prioritizes cooling efficiency downstream.

[0014] For the reasons described above, the challenge in cooling systems is to suppress pressure loss while improving the cooling performance on the downstream side. [Means for solving the problem]

[0015] The present invention was devised in view of the above-mentioned conventional problems, and one aspect thereof is a cooling device for cooling heating elements, which are arranged outside the top surface and two or more in the direction of travel and two or more in the direction of travel orthogonal to the direction of travel, with the refrigerant, and comprising an inlet for which a refrigerant flows in, an outlet for which the refrigerant flows out, and a flow path through which the refrigerant flows, and formed in a substantially rectangular parallelepiped shape by a top surface, a bottom surface, first and second sides formed parallel to the direction of travel of the refrigerant, and third and fourth sides formed perpendicular to the direction of travel, and wherein the flow path comprises a main flow path formed between two of the heating elements arranged perpendicular to the direction of travel, a first sub-flow path formed between the heating element and the first side, and a second sub-flow path formed between the heating element and the second side, and characterized in that a first fin region is formed between the main flow path and the first sub-flow path, and a second fin region is formed between the main flow path and the second sub-flow path.

[0016] Furthermore, in one embodiment, the inlet is provided on the third side of the first side surface, the outlet is provided on the fourth side of the second side surface, and the inlet is provided at the branching point of the inflow channel extending from the inlet and the first sub-channel, and guides the refrigerant into the first sub-channel, and a first acute-angled fin is provided at the branching point of the inflow channel and the main channel, and guides the refrigerant into the main channel, and a second acute-angled fin is provided at the branching point of the inflow channel and the main channel, and guides the refrigerant into the main channel, and a vertically elongated fin is provided along the third side surface of the inflow channel, and a first horizontally elongated fin is provided between the main channel and the first fin region, and a communication hole or notch is formed in the first horizontally elongated fin to connect the main channel and the first fin region, and a second horizontally elongated fin is provided between the main channel and the second fin region, and a communication hole or notch is formed in the second horizontally elongated fin to connect the main channel and the second fin region, wherein the length of the second horizontally elongated fin in the direction of travel is shorter than the length of the first horizontally elongated fin in the direction of travel.

[0017] Furthermore, in one embodiment, the inlet is provided on the third side surface, the outlet is provided on the fourth side surface, and the device is characterized by comprising a third acute-angled fin provided between the inlet and the first fin region for guiding the refrigerant to the first sub-flow channel, and a fourth acute-angled fin provided between the inlet and the second fin region for guiding the refrigerant to the second sub-flow channel.

[0018] Furthermore, in one embodiment, the main channel, the first sub-channel, and the second sub-channel are formed from the position where the third acute-angled fin and the fourth acute-angled fin are formed in the direction of travel to a predetermined position, and the third fin region is formed on the fourth side side from the predetermined position over the entire length between the first side and the second side.

[0019] Moreover, as one aspect, the inflow port is provided on the third side surface side of the bottom surface, the outflow port is provided on the fourth side surface side of the bottom surface, the cooling device comprises a third acute-angle fin disposed between the inflow port and the first fin region and configured to guide the refrigerant to the first sub-flow path, and a fourth acute-angle fin disposed between the inflow port and the second fin region and configured to guide the refrigerant to the second sub-flow path. Effects of the Invention

[0020] According to the present invention, in a cooling device, it is possible to suppress pressure loss and improve downstream cooling performance. Brief Description of the Drawings

[0021] [Figure 1] A top view showing the cooling device of Example 1. [Figure 2] A cross-sectional view of the cooling device of Example 1 taken along the directions of the first and second side surfaces. [Figure 3] A top view showing the cooling device of Example 2. [Figure 4] A cross-sectional view of the cooling device of Example 2 taken along the directions of the first and second side surfaces. [Figure 5] A top view showing the cooling device of Example 3. [Figure 6] A cross-sectional view of the cooling device of Example 3 taken along the directions of the first and second side surfaces. [Figure 7] A cross-sectional view of the cooling device of Example 3 taken along the directions of the third and fourth side surfaces. [Figure 8] A top view showing a cooling device according to a modification of Example 2. [Figure 9] A cross-sectional view of the cooling device according to the modification of Example 2 taken along the directions of the first and second side surfaces. Modes for Carrying Out the Invention

[0022] The following embodiments 1 to 3 are characterized by having a main flow path formed between two heating elements arranged perpendicular to the direction of refrigerant flow, a first sub-flow path formed between a heating element and a first side surface, and a second sub-flow path formed between a heating element and a second side surface. By having the three flow paths pass through while avoiding the semiconductor chip that generates a lot of heat, a cooler refrigerant can be supplied to the downstream side, thereby enhancing the cooling effect downstream.

[0023] Examples 1 to 3 of the cooling device according to the present invention will be described in detail below with reference to Figures 1 to 9.

[0024] [Example 1] The cooling device of Example 1 is shown in Figures 1 and 2. Figure 1 is a top view of the rectangular cooling device, and Figure 2 is a cross-sectional view in the side direction.

[0025] As shown in Figures 1 and 2, the cooling device 1 is formed in a rectangular parallelepiped shape with first and second sides 2 and 3 formed parallel to the direction of refrigerant flow, third and fourth sides 4 and 5 formed parallel to the direction perpendicular to the direction of refrigerant flow, a top surface 6, and a bottom surface 7. The space enclosed by the first side 2, second side 3, third side 4, fourth side 5, top surface 6, and bottom surface 7 serves as the flow path for the refrigerant. Hereinafter, the direction parallel to the first side 2 and second side 3 will be referred to as the direction of flow, the direction parallel to the third side 4 and fourth side 5 will be referred to as the direction perpendicular to the direction of flow, and the direction of the diagonal of the rectangle when the roughly rectangular cooling device is viewed in plan will be referred to as the diagonal direction.

[0026] Furthermore, the top surface 6 may be a heat sink for cooling the power module. As shown in Figure 2, a base plate 8 is attached to the outside (upper side) of the top surface 6. The semiconductor chip 9 of the power module is placed on top of the base plate 8. In reality, there are layers of thermal conductive grease, insulating plate, solder, copper foil, etc., but these are omitted here. This semiconductor chip 9 is a heat-generating element that is cooled by a coolant.

[0027] Furthermore, the first, second, third, and fourth sides 2, 3, 4, and 5, the top surface 6, and the bottom surface 7 may be integrally molded, forming a single heat sink.

[0028] The semiconductor chips 9 are arranged in groups of two or more in the direction of the refrigerant's movement and in groups of two or more in directions perpendicular to the direction of movement. In this embodiment 1, the semiconductor chips 9 are arranged in a total of six positions, as shown by the dashed lines in Figure 1, with three in the direction of movement and two in directions perpendicular to the direction of movement.

[0029] As shown in Figure 1, an inlet 10 for refrigerant to flow into is formed on the third side 4 side of the first side 2, and an outlet 11 for refrigerant to flow out is formed on the fourth side 5 side of the second side 3. In other words, the inlet 10 and outlet 11 are located near the diagonal of a rectangle when the rectangular parallelepiped is viewed from above. Furthermore, an inlet channel 12 extends from the inlet 10 toward the second side 3, and an outlet channel 13 extends from the outlet 11 toward the first side 2. The second side 3 side of the inlet channel 12 narrows as it approaches the second side 3.

[0030] Between two semiconductor chips 9 aligned in a direction perpendicular to the direction of travel, a main channel 14 is formed connecting an inflow channel 12 and an outflow channel 13. In addition, between the semiconductor chip 9 and the first side surface 2, a first sub-channel 15 is formed along the first side surface 2, connecting the inflow channel 12 and the outflow channel 13, and between the semiconductor chip 9 and the second side surface 3, a second sub-channel 16 is formed along the second side surface 3, connecting the inflow channel 12 and the outflow channel 13.

[0031] A first fin region 17 is formed between the main channel 14 and the first sub-channel 15, and a second fin region 18 is formed between the main channel 14 and the second sub-channel 16. Numerous small fins, not shown, exist in the first fin region 17 and the second fin region 18.

[0032] The inflow channel 12 is provided with elongated fins 19 along the third side surface 4. The elongated fins 19 are elongated in a direction perpendicular to the direction of travel, with one end of the elongated fins 19 located where the first sub-channel 15 is formed and the other end located where the main channel 14 is formed.

[0033] A triangular prism-shaped first acute-angled fin 20 is provided at the branching point between the inflow channel 12 and the first sub-channel 15. The first acute-angled fin 20 has a slope that inclines toward the fourth side 5 as it moves toward the second side 3, and this slope guides the refrigerant from the inflow channel 12 to the first sub-channel 15.

[0034] Furthermore, a triangular prism-shaped second acute-angled fin 21 is provided at the branching point between the inflow channel 12 and the main channel 14. The second acute-angled fin 21 has a slope that inclines toward the fourth side surface 5 as it moves toward the second side surface 3, and this slope guides the refrigerant from the inflow channel 12 to the main channel 14. In this embodiment, two semiconductor chips 9 are arranged in a direction perpendicular to the direction of travel, but if there were three arranged in a direction perpendicular to the direction of travel, an acute-angled fin would be added between each of them.

[0035] A first transverse fin 22 is formed between the main channel 14 and the first fin region 17. The first transverse fin 22 is elongated in the direction of travel and extends over the entire area between the inflow channel 12 and the outflow channel 13. A communication hole (or notch) 23 is formed in this first transverse fin 22, connecting the first fin region 17 and the main channel 14.

[0036] Furthermore, a second transverse fin 24 is formed between the main channel 14 and the second fin region 18. The length of the second transverse fin 24 in the direction of travel is shorter than the length of the first transverse fin 22 in the direction of travel. The second transverse fin 24 is elongated in the direction of travel, with one end formed from the inflow channel 12 and the other end located in the middle of the main channel 14, that is, on the inflow channel 12 side of the outflow channel 13 (its length is less than half). A communication hole (or notch) 25 is also formed in the second transverse fin 24, connecting the second fin region 18 and the main channel 14. The vertical fin 19, the first acute-angled fin 20, the second acute-angled fin 21, the first transverse fin 22, and the second transverse fin 24 are joined to the top surface 6 side, but they may also be joined to the bottom surface 7 side.

[0037] The following explains the flow of the refrigerant. The direction of refrigerant flow is indicated by arrows in the diagram.

[0038] As shown in Figure 1, in Embodiment 1, the flow of refrigerant is divided into three main directions by the elongated fins 19, the first acute-angled fin 20, and the second acute-angled fin 21 located near the inlet 10. The first flow is the first sub-channel 15, which changes direction by 90 degrees at the first acute-angled fin 20 and flows linearly along the first side surface 2 in the direction of travel. The second flow is the main channel 14, which flows along the elongated fin 19 in a direction perpendicular to the direction of travel, then changes direction by 90 degrees at the second acute-angled fin 21 and flows linearly between the two semiconductor chips 9 in the direction of travel. The third flow is the second sub-channel 16, which flows along the third side surface 4 in a direction perpendicular to the direction of travel to the second side surface 3 in the inlet channel 12, then changes direction by 90 degrees at the second side surface 3 and flows linearly along the second side surface 3 in the direction of travel.

[0039] Refrigerant enters the first fin region 17 from the inflow channel 12 and the first sub-channel 15, and on the third side surface 4 of the first fin region 17, the refrigerant flows diagonally toward the main channel 14. At this time, the refrigerant flows from the first fin region 17 to the main channel 14 through the communication hole 23. On the fourth side surface 5 of the first fin region 17, the refrigerant flows in the direction of travel toward the outflow channel 13.

[0040] Refrigerant enters the second fin region 18 from the inflow channel 12 and the second sub-channel 16, and on the third side surface 4 of the second fin region 18, the refrigerant flows diagonally toward the main channel 14. At this time, the refrigerant flows from the second fin region 18 to the main channel 14 through the communication hole 25. On the fourth side surface 5 of the second fin region 18, the refrigerant flows in the direction of travel toward the outflow channel 13.

[0041] The refrigerant that has been flowing through the first sub-channel 15, the first fin region 17, the main channel 14, the second fin region 18, and the second sub-channel 16 then flows into the outlet channel 13 and is discharged from the outlet 11.

[0042] With the cooling device configured in this way, the heat generated by the semiconductor chip 9 is dissipated to the cooling device 1 via the base plate 8.

[0043] As shown above, according to this embodiment 1, since the flow velocity is not made uniform, pressure loss can be suppressed.

[0044] By having the main channel 14, the first sub-channel 15, and the second sub-channel 16 pass through while avoiding the heat-generating semiconductor chip 9, a cooler with a lower temperature can be supplied to the downstream side, thereby enhancing the cooling effect on the downstream side.

[0045] Furthermore, the refrigerant flowing through the first sub-channel 15 first has its flow velocity increased as the channel narrows due to the first sharp-angled fins 20 and the elongated fins 19. It then flows through the first sub-channel 15, which is wider and lacks fins, and is slightly away from the heat-generating section, before flowing into the first fin region 17. Similarly, the refrigerant flowing through the second sub-channel 16 has its flow velocity increased as the inflow channel 12 narrows towards the second side surface 3, and flows through the second sub-channel 16 into the second fin region 18. As a result, the coldest refrigerant can be sent downstream. This makes it possible to improve the cooling performance on the downstream side.

[0046] [Example 2] Figures 3 and 4 show the cooling device 1 of this embodiment 2. As with embodiment 1, Figure 3 is a top view of the cooling device 1, and Figure 4 is a cross-sectional view of the cooling device 1 in the direction of the first and second sides 2 and 3. Parts that are the same as in embodiment 1 are denoted by the same reference numerals and their descriptions are omitted. In embodiment 1, the inlet 10 was located on the third side 4 side of the first side 2, but in embodiment 2, it is located in the center of the third side 4. Also, in embodiment 1, the outlet 11 was located on the fourth side 5 side of the second side 3, but in embodiment 2, it is located in the center of the fourth side 5.

[0047] A third acute-angled fin 26 is provided between the inlet 10 and the first fin region 17. The third acute-angled fin 26 is formed in a triangular prism shape and has a slope that inclines toward the first side surface 2 as it moves in the direction of travel. The space between the slope of the third acute-angled fin 26 and the third side surface 4 becomes the first inflow channel 12a. The slope of the third acute-angled fin 26 guides the refrigerant from the inlet 10 to the first inflow channel 12a and the first sub-channel 15.

[0048] Furthermore, a fourth acute-angled fin 27 is provided between the inlet 10 and the second fin region 18. The fourth acute-angled fin 27 is formed in a triangular prism shape and has a slope that inclines toward the second side surface 3 as it moves in the direction of travel. The space between the slope of the fourth acute-angled fin 27 and the third side surface 4 becomes the second inflow channel 12b. The slope of the fourth acute-angled fin 27 guides the refrigerant from the inlet 10 to the second inflow channel 12b and the second sub-channel 16. The third and fourth acute-angled fins 26 and 27 are joined to the top surface 6.

[0049] Furthermore, the space between the first fin region 17 and the fourth side surface 5 becomes the first outflow channel 13a, and the space between the second fin region 18 and the fourth side surface 5 becomes the second outflow channel 13b.

[0050] In this embodiment 2, the first horizontal fin 22 and the second horizontal fin 24 of embodiment 1 are not provided.

[0051] As shown in Figure 3, in this embodiment 2, similar to embodiment 1, the refrigerant flow branches into three main directions. The first flow is the main flow path 14 that proceeds straight from the inlet 10. The second flow is the first sub-flow path 15 that branches off to the first side surface 2 side by the slope of the third acute-angled fin 26. The third flow is the second sub-flow path 16 that branches off to the second side surface 3 side by the slope of the fourth acute-angled fin 27.

[0052] In this embodiment 2, since the first horizontal fin 22 and second horizontal fin 24 of embodiment 1 are not provided, the refrigerant flows from the first sub-flow channel 15 and the main flow channel 14 to the first fin region 17, and then flows from the first fin region 17 back to the first sub-flow channel 15 and the main flow channel 14 while continuing to flow in the direction of travel. Similarly, the refrigerant flows from the second sub-flow channel 16 and the main flow channel 14 to the second fin region 18, and then flows from the second fin region 18 back to the second sub-flow channel 16 and the main flow channel 14 while continuing to flow in the direction of travel.

[0053] Then, the refrigerant flowing through the first sub-channel 15 and the first fin region 17 flows into the first outlet channel 13a, and the refrigerant flowing through the second sub-channel 16 and the second fin region 18 flows into the second outlet channel 13b. The refrigerant flowing through the first outlet channel 13a and the second outlet channel 13b merge with the main channel 14 and are discharged from the outlet 11.

[0054] As described above, this embodiment 2 provides the same effects as embodiment 1. Furthermore, since the third acute-angled fin 26 and the fourth acute-angled fin 27 themselves have slopes, the surface area is increased and the flow velocity is increased, which enhances the cooling effect and increases the amount of heat exchanged.

[0055] [Example 3] The cooling device of this embodiment 3 is shown in Figures 5, 6, and 7. Figure 5 is a top view of the cooling device 1, Figure 6 is a cross-sectional view of the cooling device 1 in the first and second side directions, and Figure 7 is a cross-sectional view of the cooling device 1 in the third and fourth side directions. Parts the same as in embodiment 2 are denoted by the same reference numerals and their descriptions are omitted. In embodiment 2, the inlet 10 was provided on the third side 4 and the outlet 11 was provided on the fourth side 5, but in embodiment 3, the inlet 10 is provided on the third side 4 side of the bottom surface 7 and the outlet 11 is provided on the fourth side 5 side of the bottom surface 7.

[0056] In Embodiment 2, the third acute-angled fin 26 and the fourth acute-angled fin 27 were formed in a triangular prism shape, but in Embodiment 3, the third acute-angled fin 26 and the fourth acute-angled fin 27 are formed in a triangular pyramidal shape. That is, the inclined surface of the third acute-angled fin 26 is inclined toward the first side surface 2 as it moves in the direction of travel, and is also inclined toward the top surface 6 as it moves in the direction of travel. Similarly, the inclined surface of the fourth acute-angled fin 27 is inclined toward the second side surface 3 as it moves in the direction of travel, and is also inclined toward the top surface 6 as it moves in the direction of travel. The third acute-angled fin 26 and the fourth acute-angled fin 27 are joined to the top surface 6.

[0057] Similar to Example 2, in this Example 3 the refrigerant flow is branched into three channels: the main channel 14, the first sub-channel 15, and the second sub-channel 16. However, in this Example 3, the refrigerant is pushed upward towards the top surface 6 by the third acute-angled fin 26 and the fourth acute-angled fin 27 as it flows into the first sub-channel 15 and the second sub-channel 16.

[0058] The subsequent flow of the refrigerant is the same as in Example 2, but in Example 3, since the outlet 11 is formed on the bottom surface 7, the refrigerant is discharged from the outlet 11 on the bottom surface 7.

[0059] Therefore, this embodiment 3 produces the same effects as embodiments 1 and 2.

[0060] [Differentiation] Examples 1 to 3 described the case where there is one inlet 10 and one outlet 11, but there may be multiple inlets 10 and outlets 11. Also, the cross-sectional shape of the inlet 10 and outlet 11 may be circular or rectangular.

[0061] In all three embodiments, the shapes of the first fin region 17 and the second fin region 18 can be various, such as pins, blades, or gyroid structures. Their length can be a columnar shape from the top surface 6 to the bottom surface 7, or it can be shorter. Furthermore, the length of the fins may change, for example, becoming shorter as you move downstream. In addition, although Figures 1, 3, and 5 show the respective flow paths and fin regions not overlapping, they may overlap if a straight flow path can be secured in a tunnel-like shape, for example, by having holes in the fins.

[0062] As shown in Figure 1, the first acute-angled fin 20, the second acute-angled fin 21, the vertically elongated fin 19, the first horizontally elongated fin 22, and the second horizontally elongated fin 24 of Example 1 are shown as being formed separately, but they may also be integrally formed.

[0063] Furthermore, as shown in Figure 1, the communication holes 23 and 25 of the first transverse fin 22 and the second transverse fin 24 of Embodiment 1 have one inlet and one outlet, but the ends of the communication holes 23 and 25 may be divided, such as having multiple outlets for one inlet, or one outlet for multiple inlets.

[0064] Although Examples 2 and 3 do not have elongated fins, they may be provided between the main flow path 14 and the first fin region 17 and the second fin region 18, similar to Example 1. Here, the elongated fins may be provided over the entire area between the first and second inflow flow paths 12a and 12b and the first and second outflow flow paths 13a and 13b, as with the first elongated fin 22 in Example 1, or they may be provided only on the side of the first and second inflow flow paths 12a and 12b, as with the second elongated fin 24.

[0065] Furthermore, the first acute-angled fin 20 and the second acute-angled fin 21 in Example 1 may be shaped to increase their surface area, similar to the third acute-angled fin 26 and the fourth acute-angled fin 27 in Examples 2 and 3.

[0066] The main channel 14, the first sub-channel 15, and the second sub-channel 16 do not need to be formed along the entire length between the inflow channels 12a, 12b and the outflow channels 13a, 13b. They may be formed from the inflow channels 12a, 12b to a predetermined position, with the area beyond the predetermined position designated as a fin region. This predetermined position is preferably about 1 / 2 to 2 / 3 of the total length from the inflow channels 12a, 12b to the outflow channels 13a, 13b. This range is effective for efficiently controlling the flow of refrigerant and optimizing the cooling effect on the downstream side. A modified example of Embodiment 2 applying this is shown in Figures 8 and 9. In the modified example, as shown in Figures 8 and 9, the main channel 14, the first sub-channel 15, and the second sub-channel 16 are formed from the position where the third acute-angled fin 26 and the fourth acute-angled fin 27 are formed to a predetermined position. On the fourth side 5 side from the predetermined position, the third fin region 28 of the fin region is formed along the entire length between the first side 2 and the second side 3.

[0067] As shown in Figure 9, the main channel 14, the first sub-channel 15, and the second sub-channel 16 may have a fourth fin region 29 that is lower in height than the first fin region 17 and the second fin region 18. The shape of the third acute-angled fin 26 and the fourth acute-angled fin 27 may be a triangular pyramidal shape, similar to that of the main channel 14, the first sub-channel 15, and the second sub-channel 16, as in the case of main channel 14, the first sub-channel 15, and the second sub-channel 16.

[0068] In addition, when the flow path is formed up to a predetermined position as in this modified example, the depth position of the formed flow path is shown as being on the bottom surface 7 side in Figure 9, but it may also be on the top surface 6 side or in the center. If the main flow path 14, the first sub-flow path 15, and the second sub-flow path 16 are on the bottom surface 7 side, the top surface 6 side may be designated as the fourth fin region 29, and the flow path may be secured by shortening the fins. Figure 8 shows the case of Example 2, but in the case of Example 1 and Example 3 as well, the main flow path 14, the first sub-flow path 15, and the second sub-flow path 16 may be formed up to a predetermined position, and the area beyond the predetermined position may be designated as the fin region.

[0069] Although the present invention has been described in detail only with respect to the specific examples described above, it will be obvious to those skilled in the art that a wide variety of modifications and alterations are possible within the scope of the technical concept of the present invention, and it is natural that such modifications and alterations fall within the scope of the claims. [Explanation of Symbols]

[0070] 1...Cooling device, 2...First side, 3...Second side, 4...Third side, 5...Fourth side, 6...Top surface, 7...Bottom surface, 8...Base plate, 9...Semiconductor chip (power module, heat source), 10...Inlet, 11...Outlet, 12...Inflow path, 13...Outflow path, 14...Main flow path, 15...First secondary flow path, 16...Second secondary flow path, 17...First fin area, 18...Second fin area, 19...Long-span fin, 20...First acute-angle fin, 21...Second acute-angle fin, 22...First horizontal fin, 23...Communication hole (notch), 24...Second horizontal fin, 25...Communication hole (notch), 26...Third acute-angle fin, 27...Fourth acute-angle fin, 28...Third fin area

Claims

1. A cooling device comprising an inlet for refrigerant to flow in, an outlet for refrigerant to flow out, and a flow path through which the refrigerant flows, formed in a substantially rectangular parallelepiped shape by a top surface, a bottom surface, first and second side surfaces formed parallel to the direction of refrigerant's flow, and third and fourth side surfaces formed perpendicular to the direction of refrigerant's flow, and cooling heating elements arranged outside the top surface, two or more in the direction of refrigerant's flow, and two or more perpendicular to the direction of refrigerant's flow, wherein the heating elements are cooled by the refrigerant, The aforementioned flow path is A main flow path is formed between the two heating elements, which are arranged in a direction perpendicular to the direction of travel, A first sub-channel formed between the heating element and the first side surface, A second sub-channel formed between the heating element and the second side surface, And, equipped with, A first fin region is formed between the main channel and the first subchannel. A cooling device characterized in that a second fin region is formed between the main flow channel and the second sub-flow channel.

2. The inlet is provided on the third side of the first side, and the outlet is provided on the fourth side of the second side. A first acute-angled fin is provided at the branching point between the inflow channel extending from the inlet and the first sub-channel, and guides the refrigerant into the first sub-channel. A second acute-angled fin is provided at the branching point of the inflow channel and the main channel, and guides the refrigerant into the main channel. The inflow channel is provided with a vertically elongated fin along the third side surface, A first transversely elongated fin is provided between the main flow channel and the first fin region, A communication hole or notch formed in the first transverse fin connects the main flow channel and the first fin region, A second transversely elongated fin is provided between the main flow channel and the second fin region, A communication hole or notch formed in the second elongated fin connects the main flow channel and the second fin region, Equipped with, The cooling device according to claim 1, characterized in that the length of the second transverse fin in the direction of travel is shorter than the length of the first transverse fin in the direction of travel.

3. The inlet is provided on the third side surface, and the outlet is provided on the fourth side surface, A third acute-angled fin is provided between the inlet and the first fin region, and guides the refrigerant to the first sub-flow channel. The cooling device according to claim 1, further comprising a fourth acute-angled fin provided between the inlet and the second fin region for guiding the refrigerant to the second sub-flow channel.

4. The cooling device according to claim 3, characterized in that the main flow path, the first sub-flow path, and the second sub-flow path are formed from the position where the third acute-angled fin and the fourth acute-angled fin are formed in the direction of travel to a predetermined position, and the third fin region is formed on the fourth side side from the predetermined position over the entire length between the first side and the second side.

5. The inlet is provided on the third side of the bottom surface, and the outlet is provided on the fourth side of the bottom surface. A third acute-angled fin is provided between the inlet and the first fin region, and guides the refrigerant into the first sub-flow channel. A fourth acute-angled fin is provided between the inlet and the second fin region, which guides the refrigerant to the second sub-flow channel, The cooling device according to claim 1, characterized by comprising:

6. A power conversion device comprising a cooling device described in any one of claims 1 to 5, and a power module cooled by the cooling device.

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