Electrical component

Abstract

This electrical component includes a plurality of semiconductors arranged in a planar direction, and a cooler that cools the plurality of semiconductors by means of a refrigerant flowing through a refrigerant flow path. A heat transfer member that transports, via a working fluid, heat generated in the semiconductors thermally connects surfaces of the adjacent semiconductors at least on one side in the thickness direction.

Description

Electrical component

[0001] The present invention relates to an electrical component.

[0002] For example, in an electrical component composed of a plurality of semiconductors such as an inverter used for driving a motor of an electric vehicle, the maximum current is determined in consideration of variations in characteristics between semiconductors and variations in temperature. Therefore, the maximum current has to be set to a size that matches the worst conditions within the range of variations, and it cannot be said that the performance of the semiconductors is fully exhibited.

[0003] JP2012 - 43915A discloses a semiconductor module for realizing sufficient heat dissipation performance without increasing the size of the module itself. This semiconductor module includes heat pipes arranged on the front and back surfaces of the semiconductor and cooling fins sandwiched between these heat pipes.

[0004] The semiconductor module described in the above document can realize sufficient heat dissipation performance, but does not consider the temperature variation between semiconductor modules when using a plurality of semiconductor modules, for example, when used as the above inverter. That is, when used as an inverter, the maximum current is restricted to a size that takes into account the temperature variation between semiconductor modules, so the performance of the semiconductors cannot be fully exhibited.

[0005] Therefore, an object of the present invention is to provide an electrical component related to an electrical component including a plurality of semiconductors and capable of setting a larger maximum current.

[0006] According to an aspect of the present invention, there is provided an electrical component including a plurality of semiconductors arranged in a planar direction and a cooler that cools the plurality of semiconductors with a refrigerant flowing through a refrigerant flow path. In this electrical component, a heat transfer member that transports heat generated by the semiconductors through a working fluid thermally connects at least one surface in the thickness direction of adjacent semiconductors to each other.

[0007] Figure 1 is a plan view showing the schematic configuration of an electrical component according to the first embodiment. Figure 2 is a cross-sectional view along the line II-II in Figure 1. Figure 3 is a cross-sectional view along the line III-III in Figure 1. Figure 4 is a diagram showing an example of a structure for fixing a heat transfer member. Figure 5 is a plan view showing the schematic configuration of an electrical component according to the second embodiment. Figure 6 is a cross-sectional view along the line VI-VI in Figure 5. Figure 7 is a plan view showing the schematic configuration of an electrical component according to the third embodiment. Figure 8 is a cross-sectional view along the line VIII-VIII in Figure 7. Figure 9 is a plan view showing the schematic configuration of an electrical component according to the first modified example. Figure 10 is a cross-sectional view along the line X-X in Figure 9. Figure 11 is a plan view showing the schematic configuration of an electrical component according to the second modified example. Figure 12 is a plan view showing the schematic configuration of an electrical component according to the fourth modified example.

[0008] Embodiments of the present invention will be described below with reference to the drawings.

[0009] [First Embodiment] Figure 1 is a plan view showing the schematic configuration of the electrical component 1. The thick arrows in the figure indicate the flow of refrigerant in the cooler 3. Figure 2 is a cross-sectional view along the line II-II in Figure 1. Figure 3 is a cross-sectional view along the line III-III in Figure 1.

[0010] The electrical component 1 according to this embodiment includes an inverter 2 that drives a three-phase AC electric motor (not shown) which is the drive source of an electric vehicle, a cooler 3 for cooling the inverter 2, and a heat transfer member 4 that mitigates temperature variations among a plurality of semiconductors (hereinafter also referred to as arms 5) that constitute the inverter 2. The electric vehicle referred to here is, for example, an electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), etc. It should be noted that this can also be applied to mobile bodies other than automobiles, such as drones and other flying objects, ships, and agricultural machinery, as long as they use an electric motor as a drive source.

[0011] The inverter 2 is switched-controlled by a control circuit (not shown) to perform bidirectional power conversion between a DC power supply (not shown) and a three-phase AC electric motor. Specifically, it converts the DC voltage supplied from the DC power supply into a three-phase AC voltage and outputs it to the electric motor. During regenerative braking of the vehicle, it also converts the three-phase AC voltage generated by the electric motor due to the rotational force from the wheels into a DC voltage and outputs it to the DC power supply.

[0012] The inverter 2 is equipped with three arms 5 for the U-phase, V-phase, and W-phase. Each arm 5 is equipped with a semiconductor element 10, such as an IGBT, and electrodes 11 arranged on both sides thereof. It is desirable that the electrodes 11 also have a heat dissipation function. The semiconductor element 10 may be a discrete component or a specially designed component. In this embodiment, if it is necessary to distinguish between multiple arms 5, they are designated as the U-phase upper arm 5UH, the U-phase lower arm 5UL, the V-phase upper arm 5VH, the V-phase lower arm 5VL, the W-phase upper arm 5WH, and the W-phase lower arm 5WL.

[0013] Multiple arms 5 are arranged in a 2x3 matrix in the planar direction. The upper row consists of the U-phase upper arm 5UH, the V-phase upper arm 5VH, and the W-phase upper arm 5WH, while the lower row consists of the U-phase lower arm 5UL, the V-phase lower arm 5VL, and the W-phase lower arm 5WL. The upper and lower rows are arranged so that the upper and lower arms of the U-phase, V-phase, and W-phase face each other in the column direction. The P-pole, which is the electrode on the high-potential side, is connected to the U-phase upper arm 5UH, and the N-pole, which is the electrode on the low-potential side, is connected to the U-phase lower arm 5UL.

[0014] The cooler 3 has the function of absorbing heat generated by the inverter 2 using a refrigerant such as a coolant or air. The refrigerant, whose temperature has risen after absorbing heat, is cooled using a radiator (not shown) or the like. The cooler 3 includes a refrigerant flow path 12 and fins 13 positioned facing the refrigerant flow path 12.

[0015] The refrigerant flow path 12 is a series of flow paths consisting of an upper row-direction flow path along the row in which the upper arms 5 are lined up, a lower row-direction flow path along the row in which the lower arms 5 are lined up, and a column-direction flow path connecting the W-phase ends of the upper and lower row-direction flow paths. A refrigerant inlet is provided at the U-phase end of the upper row-direction flow path, and a refrigerant outlet is provided at the U-phase end of the lower row-direction flow path.

[0016] The fins 13 protrude from the surface of the cooler housing 3 that contacts the arms 5 into the refrigerant flow path 12. As a result, the heat generated in each arm 5 is transferred to the refrigerant flowing through the refrigerant flow path 12 via the fins 13.

[0017] The heat transfer member 4 has the function of transporting heat through a working fluid sealed inside the housing and uses a so-called heat pipe, which comprises a wick (not shown) that forms a capillary channel through which a liquid-phase working fluid flows, and a vapor channel (not shown) through which a gas-phase working fluid flows. Note that the heat transfer member 4 is not limited to a heat pipe, but can be any device that has the function of transporting heat through a working fluid.

[0018] The heat transfer member 4 includes an upper row-direction heat transfer member 4RH positioned across the U-phase upper arm 5UH, V-phase upper arm 5VH, and W-phase upper arm 5WH, which are arranged in the row direction, and a lower row-direction heat transfer member 4RL positioned across the U-phase lower arm 5UL, V-phase lower arm 5VL, and W-phase lower arm 5WL. When there is no need to distinguish between them, they are referred to as row-direction heat transfer member 4R. The method for fixing the heat transfer member 4 will be described later.

[0019] In the row of the upper arms 5, the refrigerant flow of the cooler 3 is upstream of the U-phase upper arm 5UH and downstream of the W-phase upper arm 5WH. At the downstream W-phase upper arm 5WH, the refrigerant temperature is higher than at the upstream U-phase upper arm 5UH. Therefore, the W-phase upper arm 5WH tends to be hotter than the U-phase upper arm 5UH. In other words, temperature variations are likely to occur among the three arms 5 arranged in the row direction. In this embodiment, this temperature variation can be mitigated by arranging the upper row-direction heat transfer member 4RH. Specifically, the working fluid boils on the side of the W-phase upper arm 5WH, which is hotter, and the vapor moves to the U-phase upper arm 5UH side, which is cooler, due to the pressure difference. There, it condenses and liquefies, and the liquefied working fluid returns to the W-phase upper arm 5WH side through the wick by capillary action. This movement of the working fluid mitigates the temperature variations among the three upper arms 5. In addition, due to factors such as the characteristics of the semiconductor element 10 and the spacing between adjacent arms 5, the central V-phase upper arm 5VH may reach the highest temperature. However, even in this case, the temperature variation can be mitigated by the behavior of the working fluid described above. The same applies to the lower row of arms 5; the temperature variation of the W-phase lower arm 5WL, V-phase lower arm 5VL, and U-phase lower arm 5UL, which are arranged in order from upstream to downstream of the refrigerant flow, can be mitigated.

[0020] Furthermore, since the refrigerant flow path of the cooler 3 is a series of flow paths, the lower arm 5, which is downstream, tends to become hotter than the upper arm 5, which is upstream. Therefore, the heat transport rate of the lower-row heat transfer member 4RL may be made larger than the heat transport rate of the upper-row heat transfer member 4RH. To increase the heat transport rate, for example, at least one of the following can be done: increase the cross-sectional area of ​​the flow path through which the liquid-phase working fluid flows, or configure the wick to further promote capillary action.

[0021] Conventionally, the maximum current of a module equipped with multiple semiconductor elements 10 was set based on the worst-case scenario, taking into account variations in characteristics and temperature between the semiconductor elements 10. As a result, the performance of the semiconductor elements 10 could not be fully utilized. However, in this embodiment, by providing a heat transfer member 4, temperature variations between each arm 5 can be mitigated, and heat concentration in a specific arm 5 can be suppressed, allowing a larger maximum current to be set.

[0022] Here, the method for fixing the heat transfer member 4 will be explained with reference to Figure 4. Figure 4 shows an example of a structure for fixing the heat transfer member 4, which was omitted in Figures 1 to 3.

[0023] The heat transfer member 4 is fixed in place against the arm 5 by a holding member 20 having a recess corresponding to the shape of the heat transfer member 4. The holding member 20 is fixed to the housing of the cooler 3 by bolts 21. During assembly, the heat transfer member 4 is placed in the recess of the holding member 20, and the holding member 20 is then assembled to the cooler 3. This makes it easy to position the heat transfer member 4 relative to the arm 5.

[0024] In this embodiment, an electrical component 1 is provided, comprising a plurality of arms 5 arranged in a planar direction, and a cooler 3 that cools the plurality of arms 5 with a coolant flowing through a coolant channel 12. In this electrical component 1, a heat transfer member 4 that transports heat generated in the arms 5 via a working fluid thermally connects at least one surface of adjacent arms 5 in the thickness direction. As a result, the heat transfer member 4 transports heat from a high-temperature arm 5 to a low-temperature arm 5, thereby mitigating temperature variations between the arms 5. Consequently, it becomes possible to set a larger maximum current.

[0025] [Second Embodiment] The second embodiment will be described with reference to Figures 5 and 6.

[0026] Figure 5 is a plan view showing the schematic configuration of the electrical component 1 according to this embodiment. The thick arrows in the figure indicate the flow of refrigerant in the cooler 3. Figure 6 is a cross-sectional view along the line V-V in Figure 5.

[0027] The difference from the first embodiment is the inclusion of a column-direction heat transfer member 4C that spans across adjacent arms 5 in the column direction. The column-direction heat transfer member 4C is a heat pipe, similar to the row-direction heat transfer member 4R. When it is necessary to distinguish between the column-direction heat transfer members 4C, the U-phase column-direction heat transfer member 4C is designated as the U-phase heat transfer member 4CU, the V-phase column-direction heat transfer member 4C is designated as the V-phase heat transfer member 4CV, and the W-phase column-direction heat transfer member 4CC is designated as the W-phase heat transfer member 4CW.

[0028] This reduces temperature variations between the upper row arm 5 and the lower row arm 5, thereby reducing temperature variations within the inverter 2.

[0029] From the standpoint of refrigerant temperature, the lower arm 5UL of the U-phase is at the highest temperature, followed by the lower arm 5VL of the V-phase, the lower arm 5WL of the W-phase, the upper arm 5WH of the W-phase, the upper arm 5VH of the V-phase, and the upper arm 5UH of the U-phase, in that order of decreasing temperature. Therefore, the temperature difference between the upper and lower arms 5 is U-phase > V-phase > W-phase. Accordingly, the amount of heat transported by the column-direction heat transfer member 4C may be increased for those connected to semiconductor elements 10 (i.e., arms 5) located closer to the refrigerant outlet of the refrigerant flow path 12. In other words, the amount of heat transported may be U-phase heat transfer member 4CU > V-phase heat transfer member 4CV > W-phase heat transfer member 4CW.

[0030] The electrical component 1 according to this embodiment includes a plurality of arms 5 arranged in a matrix consisting of a plurality of rows and a plurality of columns, a plurality of row-direction heat transfer members 4R that thermally connect the plurality of arms 5 arranged in the row direction, and a plurality of column-direction heat transfer members 4C that thermally connect the plurality of arms 5 arranged in the column direction. By further including the column-direction heat transfer members 4C in addition to the configuration of the first embodiment, temperature variations between each arm 5 can be further suppressed.

[0031] In this embodiment, the refrigerant flow path 12 of the cooler 3 is a series of flow paths formed by a row-direction flow path provided for each row of arms 5, extending from one end in the row direction to the other, and a column-direction flow path connecting one end of adjacent row-direction flow paths. The heat transfer member 4 comprises a wick that forms a capillary flow path through which liquid-phase working fluid flows, and a vapor flow path through which gas-phase working fluid flows. The row-direction heat transfer member 4R has a greater heat transfer capacity the further downstream it is located in the refrigerant flow path 12, and the column-direction heat transfer member 4C has a greater heat transfer capacity the closer it is connected to the arm 5 located near the refrigerant outlet of the refrigerant flow path 12. As a result, heat transfer by the heat transfer member 4 is promoted in areas where the temperature of the refrigerant flowing in the refrigerant flow path 12 is high, thereby efficiently mitigating temperature variations between each arm 5.

[0032] [Third Embodiment] The third embodiment will be described with reference to Figures 7 and 8.

[0033] Figure 7 is a plan view showing the schematic configuration of the electrical component 1 according to this embodiment. Figure 8 is a cross-sectional view along the line VIII-VIII in Figure 7.

[0034] The difference from the first embodiment lies in the orientation of the electrical component 1 in its installed state (hereinafter also referred to as the installation orientation). In the first embodiment, the installation orientation of the electrical component 1 is not limited, but in this embodiment, the installation orientation of the electrical component 1 is limited to an orientation inclined with respect to the horizontal direction. For example, while the electrical component 1 in the first embodiment is configured to be installed horizontally on the upper surface of the motor housing, the electrical component 1 in this embodiment is configured to be installed on the side of the motor housing. Another difference is the configuration of the refrigerant flow path 12 in the cooler 3.

[0035] As shown in Figure 7, the plane in which the six arms 5 are arranged in a matrix is ​​inclined with respect to the horizontal direction, similar to the first embodiment. Specifically, the inverter 2 shown in Figure 1 is in a position where the U phase is on the bottom and the W phase is on the top. In this position, the row direction and column direction would normally be reversed compared to Figure 1, but to avoid confusion, in the following explanation, the direction in which the upper arms 5 are lined up will be referred to as the row direction, and the direction in which the upper arms 5 and lower arms 5 of each phase are lined up will be referred to as the column direction, similar to the first embodiment.

[0036] Similar to the first embodiment, the heat transfer member 4 includes an upper-row heat transfer member 4RH positioned across the U-phase upper arm 5UH, V-phase upper arm 5VH, and W-phase upper arm 5WH, and a lower-row heat transfer member 4RL positioned across the U-phase lower arm 5UL, V-phase lower arm 5VL, and W-phase lower arm 5WL. In other words, both the upper-row heat transfer member 4RH and the lower-row heat transfer member 4RL in this embodiment thermally connect adjacent arms 5 in the direction of plane inclination.

[0037] The cooler 3 is equipped with two refrigerant flow paths 12: an upper row-direction flow path along the row in which the upper arms 5 are lined up, and a lower row-direction flow path along the row in which the lower arms 5 are lined up. Both flow paths are equipped with a refrigerant inlet at the upper end in the direction of gravity and a refrigerant outlet at the lower end.

[0038] In other words, the U-phase upper arm 5UH and U-phase lower arm 5UL, which are aligned at the lower end in the plane, are located on the downstream end side of the refrigerant flow path 12.

[0039] In the configuration described above, the refrigerant cools the arms 5 in the order of W phase, V phase, and U phase, so the U phase arm 5 tends to become hotter than the W phase arm 5. The working fluid of the heat transfer member 4 becomes a gas due to the heat of the U phase arm 5 located on the lower side in the direction of gravity, moves upward in the direction of gravity, condenses into a liquid phase, and returns to the lower side in the direction of gravity through the wick. In this way, with the condensation part of the heat transfer member 4 on the upper side in the direction of gravity and the evaporation part on the lower side in the direction of gravity, the gas phase working fluid moves easily to the condensation part, and the liquid phase working fluid moves easily to the evaporation part due to gravity in addition to capillary action. As a result, the heat transport efficiency of the heat transfer member 4 is improved, and it becomes possible to more efficiently mitigate temperature variations among the multiple arms 5.

[0040] In this embodiment, the case where the plane is perpendicular to the horizontal direction has been described, but the angle of inclination of the plane is not limited to this.

[0041] In this embodiment, a plurality of arms 5 are arranged in a matrix consisting of a plurality of rows and a plurality of columns. The plane in which the plurality of arms 5 are arranged is inclined with respect to the horizontal direction. At least one of the arms 5 arranged at the lower end in the plane is located on the downstream end side of the refrigerant flow path 12, and the heat transfer member 4 thermally connects the arms 5 adjacent to each other in the inclination direction. As a result, the arms 5 located more downward in the gravitational direction are more likely to become higher in temperature. Therefore, the working fluid becomes vapor phase on the lower side and rises, and becomes liquid phase on the upper side and descends. When descending, in addition to the capillary phenomenon, gravity acts, improving the efficiency of heat transport. Thus, temperature variations can be more efficiently alleviated.

[0042] Next, a modified example of the third embodiment will be described. Any of the following modified examples belongs to the technical scope of the present invention in the same manner as the third embodiment.

[0043] (First Modified Example) The first modified example of the third embodiment will be described with reference to FIGS. 9 and 10.

[0044] FIG. 9 is a plan view showing a schematic configuration of the electrical component 1 according to this embodiment. FIG. 10 is a cross-sectional view taken along the line X-X of FIG. 9.

[0045] The difference between this modified example and the third embodiment is the refrigerant flow path 12 of the cooler 3. The refrigerant flow path 12 of this modified example is the same as that of the first embodiment, and includes an upper row direction flow path along the row in which the upper arms 5 are arranged, a lower row direction flow path along the row in which the lower arms 5 are arranged, and a column direction flow path connecting the W-phase side ends of the upper and lower row direction flow paths, forming a series of flow paths. A refrigerant inlet is provided at the U-phase side end of the upper row direction flow path, and a refrigerant outlet is provided at the U-phase side end of the lower row direction flow path.

[0046] Regarding the row in which the upper arms 5 are arranged, since the temperature of the refrigerant in the cooler 3 is lower toward the lower side in the gravitational direction, it is not possible to expect an improvement in the heat transport efficiency by utilizing the action of gravity as described above for the upper row direction heat transfer member 4RH. However, since the row in which the upper arms 5 are arranged is the upstream side of the refrigerant flow and the temperature of the refrigerant is low, the temperature of each arm 5 is difficult to rise. Therefore, temperature variations can be sufficiently alleviated without improving the heat transport efficiency.

[0047] On the other hand, since the row in which the lower arm 5 is arranged is the downstream side of the refrigerant flow, it is effective to improve the heat transport efficiency by setting the downstream side of the refrigerant flow downward in the gravitational direction as in the third embodiment.

[0048] (Second Variant Example) The second variant example of the third embodiment will be described with reference to FIG. 11.

[0049] FIG. 11 is a plan view showing a schematic configuration of the electrical component 1 according to this variant example.

[0050] In the electrical component 1 of this variant example, the plane in which a plurality of arms 5 are arranged in a matrix direction is perpendicular to the horizontal direction, and in the plane, the row in which the upper arms 5 are arranged is on the upper side in the gravitational direction, and the row in which the lower arms 5 are arranged is on the lower side in the gravitational direction.

[0051] Three heat transfer members 4, namely, a U-phase heat transfer member 4CU, a V-phase heat transfer member 4CV, and a W-phase heat transfer member 4CW, are arranged.

[0052] The refrigerant flow path 12 is the same as that in the first embodiment, and is a series of flow paths composed of an upper row direction flow path along the row in which the upper arms 5 are arranged, a lower row direction flow path along the row in which the lower arms 5 are arranged, and a column direction flow path connecting the ends on the W-phase side of the upper and lower row direction flow paths. A refrigerant inlet is provided at the end on the U-phase side of the upper row direction flow path, and a refrigerant outlet is provided at the end on the U-phase side of the lower row direction flow path.

[0053] In the configuration of this variant example, in each of the U-phase, V-phase, and W-phase, the upper arm 5 is the upstream side of the refrigerant flow, the lower arm 5 is the downstream side of the refrigerant flow, and the upper and lower arms 5 are thermally connected by the column direction heat transfer member 4C. Thus, similar to the third embodiment, the effect of improving the heat transport efficiency using gravity can be obtained by each column direction heat transfer member 4C.

[0054] [Fourth Embodiment] The fourth embodiment will be described with reference to FIG. 12.

[0055] FIG. 12 is a plan view showing a schematic configuration of the electrical component 1 according to this embodiment.

[0056] The difference between this embodiment and the first embodiment is that a vapor chamber 22 is used as the heat transfer member 4 instead of a heat pipe.

[0057] The vapor chamber 22 is positioned to cover the upper surfaces of multiple arms 5 arranged in a matrix.

[0058] Even with the above configuration, temperature variations between each arm 5 can be mitigated, similar to the first embodiment.

[0059] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Claims

1. An electrical component comprising: a plurality of semiconductors arranged in a planar direction; and a cooler that cools the plurality of semiconductors with a coolant flowing through a coolant channel, wherein a heat transfer member that transports the heat generated in the semiconductors via a working fluid thermally connects at least one surface of adjacent semiconductors in the thickness direction.

2. An electrical component according to claim 1, wherein a plurality of semiconductors are arranged in a matrix consisting of a plurality of rows and a plurality of columns, and the plurality of row-direction heat transfer members thermally connect the plurality of semiconductors arranged in the row direction, and a plurality of column-direction heat transfer members thermally connect the plurality of semiconductors arranged in the column direction.

3. An electrical component according to claim 2, wherein the coolant flow path of the cooler is a series of flow paths formed by a row-direction flow path provided for each row of semiconductors and extending from one end in the row direction to the other end, and a column-direction flow path connecting one end of adjacent row-direction flow paths, the heat transfer member comprises a wick that forms a capillary flow path through which the liquid phase working fluid flows, and a vapor flow path through which the gas phase working fluid flows, the heat transfer capacity of the row-direction heat transfer member is greater the further downstream it is located in the coolant flow path, and the heat transfer capacity of the column-direction heat transfer member is greater the further it is connected to the semiconductor located closer to the coolant outlet of the coolant flow path.

4. An electrical component according to claim 1, wherein a plurality of semiconductors are arranged in a matrix consisting of a plurality of rows and a plurality of columns, the plane on which the plurality of semiconductors are arranged is inclined with respect to the horizontal direction, at least one of the semiconductors arranged at the lower end of the plane is located on the downstream end side of the refrigerant flow path, and the heat transfer member thermally connects adjacent semiconductors in the direction of inclination.

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