JP5492638B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device that cools a semiconductor module using a refrigerant.

  For example, as a power conversion device that performs power conversion between DC power and AC power, as shown in FIG. 10, a semiconductor module 94 in which a semiconductor element 95 constituting a power conversion circuit is sealed, and the semiconductor module 94 is cooled. The thing provided with the cooling case 91 through which the refrigerant | coolant 96 which flows is known (refer the following patent document 1). In this power conversion device 90, the cooling case 91 has an opening 99 that opens upward, and a metal upper wall plate 97 and a semiconductor module 94 are attached so as to close the opening 99.

  The cooling case 91 is provided with a refrigerant introduction pipe 92 and a refrigerant outlet pipe 93. A refrigerant 96 is introduced into the cooling case 91 from the refrigerant introduction pipe 92 and led out from the refrigerant outlet pipe 93. Thereby, the refrigerant 96 is caused to flow in the cooling case 91 to cool the semiconductor module 94.

JP 2006-166604 A

  However, the bubbles 98 may flow into the cooling case 91 together with the refrigerant 96, and the conventional power converter 90 has a problem that the bubbles 98 are likely to accumulate in the cooling case 91. That is, in the conventional power converter 90, the upper wall plate 97 exists above the inlet 920 and outlet 930 of the refrigerant 96, so that the bubbles 98 that have entered the cooling case 91 together with the refrigerant 96 from the inlet 920. It floats and accumulates below the upper wall plate 97. Since air has a lower thermal conductivity than the refrigerant 96 such as water, heat exchange between the refrigerant 96 and the upper wall plate 97 is less likely to occur when the bubbles 98 accumulate below the upper wall plate 97, and the semiconductor module. The cooling efficiency of 94 tends to decrease.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a power conversion device in which bubbles contained in a refrigerant are less likely to accumulate in a cooling case.

The present invention includes a cooling case including a bottom wall, a side wall standing upward from a peripheral edge of the bottom wall, and a metal upper wall plate attached to the upper end of the side wall.
A semiconductor module comprising a power conversion circuit and a sealing portion that seals the semiconductor element, and is disposed on the upper surface of the upper wall plate; and
A refrigerant inlet pipe and a refrigerant outlet pipe provided on the side wall,
The refrigerant is introduced from the refrigerant introduction pipe into the space in the case surrounded by the bottom wall, the side wall, and the upper wall board, and the refrigerant is led out from the refrigerant outlet pipe to be arranged on the upper wall board. The semiconductor module is configured to be cooled with the refrigerant,
The outlet opening end of the refrigerant outlet pipe, which is the end opened to the space in the case, has an upper end edge located above the lower surface of the upper wall plate ,
In the power conversion device , an air escape groove recessed upward is formed in the lower surface of the upper wall plate .

The function and effect of the present invention will be described. In the present invention, the upper end edge of the lead-out opening end is located above the lower surface of the upper wall plate.
This makes it difficult for bubbles to accumulate in the cooling case. That is, when air bubbles are included in the refrigerant introduced into the cooling case from the refrigerant introduction pipe, the air bubbles are lighter than the refrigerant, so that the air bubbles rise and come into contact with the lower surface of the upper wall plate. As the refrigerant flows, the bubbles move downstream along the lower surface of the upper wall plate and reach the vicinity of the outlet opening end. In the present invention, since the upper end edge of the outlet side opening end is positioned above the lower surface of the upper wall plate, the bubbles can enter the refrigerant outlet pipe while floating as they are.
If the upper end edge of the lead-out opening end is positioned below the lower surface of the upper wall plate, the bubbles cannot be easily discharged because the bubbles cannot move downward. Therefore, it becomes easy for bubbles to collect on the lower surface of the upper wall plate. On the other hand, in the present invention, since the upper end edge of the outlet opening end is located above the lower surface of the upper wall plate, bubbles can easily enter the refrigerant outlet tube. Therefore, it is difficult for bubbles to accumulate in the cooling case. Thereby, the fall of the cooling efficiency of a semiconductor module can be suppressed.

  As described above, according to the present invention, it is possible to provide a power conversion device in which bubbles contained in the refrigerant are less likely to accumulate in the cooling case.

The disassembled perspective view of the cooling case in Reference Example 1. It is AA sectional drawing of FIG. 1, Comprising: The thing drawn with the semiconductor module and the cooling fin. FIG. 2 is a cross-sectional view taken along the line B-B in FIG. 1 together with a semiconductor module and cooling fins. The disassembled sectional view of the power converter in Reference Example 1. The disassembled perspective view of the cooling case in Reference Example 2. It is CC sectional drawing of FIG. 5, Comprising: The thing drawn with the semiconductor module and the cooling fin. Sectional drawing of the power converter device in Example 1. FIG. DD sectional drawing of FIG. Sectional drawing of the power converter device in the reference example 3. FIG. Sectional drawing of the power converter device in a prior art example.

A preferred embodiment of the present invention described above will be described.
In the present invention, the above lower surface of the upper wall plate, the air escape groove recessed upwardly that have been formed.
Therefore , the effect of this invention that the bubble contained in a refrigerant | coolant cannot collect easily in a cooling case can be exhibited effectively. That is, by forming the air escape groove around the cooling fin, it is possible to guide the bubbles that have entered the case together with the refrigerant from the refrigerant introduction pipe to the air escape groove. Therefore, for example, when a cooling fin exists, it becomes difficult for bubbles to adhere to the gap between the cooling fin and the upper wall plate, and it is possible to suppress a decrease in the cooling efficiency of the semiconductor module. Further, since the air bubbles entering the air escape groove move downstream with the flow of the refrigerant, they can be easily discharged out of the case from the refrigerant outlet pipe.

Moreover, it is preferable that the said semiconductor module and the said upper wall board are comprised integrally by the said sealing part being closely_contact | adhered with the said upper wall board (Claim 2 ).
If it does in this way, since a semiconductor module and an upper wall board can be united, the number of parts can be reduced and it becomes possible to reduce the manufacturing cost of a power converter.

Moreover, it is preferable that the upper end edge of the inlet side opening end portion, which is the end portion opened to the space in the case, of the refrigerant introduction pipe is located above the lower surface of the upper wall plate (claim). Item 3 ).
In this case, even if the refrigerant introduced from the refrigerant introduction pipe contains bubbles, the lower surface of the upper wall plate is positioned below the upper end edge of the inlet side opening end, so that the bubbles are in the case. It becomes difficult to enter the interior space. Thereby, it becomes easy to prevent air bubbles from accumulating in the cooling case.

In addition, an air inflow prevention portion for preventing air bubbles from flowing into the space in the case is provided at an upper end portion of the side wall to which the refrigerant introduction pipe is attached, and the air inflow prevention portion is provided from the upper end portion of the side wall. While extending obliquely downward toward the inner space of the case, the lower end thereof is positioned below the upper end edge of the inlet side opening end that is the end of the refrigerant introduction pipe that opens into the inner space of the case. (Claim 4 ).
If it does in this way, since a bubble accumulates between the opening end part of an introduction side, and the lower end of an air inflow prevention part, it can prevent that a bubble enters into the downstream rather than an air inflow prevention part. This makes it easier to prevent bubbles from accumulating in the cooling case.

( Reference Example 1)
A power converter according to a reference example of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 to 3, the power conversion apparatus 1 of this example includes a cooling case 2, a semiconductor module 3, a refrigerant introduction pipe 4, and a refrigerant outlet pipe 5.
The cooling case 2 includes a bottom wall 20, a side wall 21 erected upward from the peripheral edge of the bottom wall 20, and a metal upper wall plate 22 attached to the upper end of the side wall 21. The side wall 21 is provided with a refrigerant introduction pipe 4 and a refrigerant outlet pipe 5.
As shown in FIGS. 2 and 3, the semiconductor module 3 includes a semiconductor element 30 constituting a power conversion circuit and a sealing portion 31 that seals the semiconductor element 30, and the upper surface of the upper wall plate 22. 221 is arranged.

As shown in FIG. 3, the power conversion device 1 introduces the refrigerant 10 from the refrigerant introduction pipe 4 into the space S in the case surrounded by the bottom wall 20, the side wall 21, and the upper wall plate 22, and the refrigerant from the refrigerant outlet pipe 5. By deriving 10, the semiconductor module 3 disposed on the upper wall plate 22 is cooled by the refrigerant 10.
The outlet side opening end 50, which is the end of the refrigerant outlet pipe 5 that opens into the case internal space S, has an upper end edge 51 positioned above the lower surface 220 of the upper wall plate 22.
The details will be described below.

  As shown in FIG. 1, the bottom wall 20 is formed in a quadrilateral plate shape, and four side walls 21 are erected from the peripheral edge portion. The side wall 21 includes a first side wall 21a provided with the refrigerant introduction pipe 4, a second side wall 21b provided with the refrigerant outlet pipe 5, and a third side wall having a height lower than those of the first side wall 21a and the second side wall 21b. 21c and a fourth side wall 21d. The upper wall plate 22 is placed on the upper end surface 210 of the third side wall 21c and the fourth side wall 21d. Further, a bolt insertion hole 222 is formed in the upper wall plate 22, and a fastening hole 223 for screwing the bolt 12 (see FIG. 2) is formed in the third side wall 21c and the fourth side wall 21d. While the bolt 12 is inserted into the bolt insertion hole 222 and the bolt 12 is screwed into the fastening hole 223, the upper wall plate 22 is fixed to the third side wall 21c and the fourth side wall 21d. Seal members 11 for preventing leakage of the refrigerant 10 are attached between the upper wall plate 22 and the first side wall 21a and between the upper wall plate 22 and the second side wall 21b. Further, as shown in FIG. 3, the upper end surfaces 211 of the first side wall 21a and the second side wall 21b and the upper surface 221 of the upper wall plate 22 are substantially flush with each other.

As shown in FIG. 2, the semiconductor module 3 includes a signal terminal 33, power terminals 34 and 35, a metal heat radiating plate 32, and an insulating member 37 connected to the semiconductor element 30. The power terminal 34 is connected to the semiconductor element 30 via the solder 36a. Further, the power terminal 35 is connected to the semiconductor element 30 through the heat sink 32 and the solder 36b. The signal terminal 33 is connected to a control circuit board (not shown). The control circuit board controls the operation of the semiconductor element 30 to control the amount and timing of the current flowing between the power terminals 34 and 35.
Further, although the heat radiating plate 32 is connected to the power terminal 35, since the insulating member 37 is interposed between the heat radiating plate 32 and the upper wall plate 22, the upper wall plate 22 is insulated from the power terminal 35.

As shown in FIG. 4, the semiconductor module 3 seals the heat radiating plate 32, the signal terminal 33, the power terminals 34 and 35, and the insulating member 37 with a part of the signal terminal 33 and the power terminals 34 and 35 protruding. It is sealed by the part 31. In this example, the semiconductor module 3 and the upper wall plate 22 are integrated by bringing the main surface of the insulating member 37 into surface contact with the upper wall plate 22 and bringing the sealing portion 31 into close contact with the upper wall plate 22. ing.
A wave-shaped cooling fin 6 is attached to the lower surface 220 of the upper wall plate 22. The upper end portion 60 of the cooling fin 6 is welded to the lower surface 220 of the upper wall plate 22. As shown in FIG. 3, the end 6a on the side where the refrigerant 10 is introduced into the cooling fin 6 faces the refrigerant introduction pipe 4 side, and the end 6b on the side where the refrigerant 10 is led out from the cooling fin 6 is on the refrigerant outlet pipe 5 side. The cooling fins 6 are arranged in the cooling case 2 so as to face.

  On the other hand, as shown in FIG. 3, the inlet side opening end 40, which is the end of the refrigerant introduction pipe 4 that opens into the space S in the case, has an upper edge 41 that is higher than the lower surface 220 of the upper wall plate 22. positioned.

The effect of this example will be described. As shown in FIG. 3, in this example, the upper end edge 51 of the lead-out opening end 50 is located above the lower surface 220 of the upper wall plate 22.
If it does in this way, it will become difficult for the bubble 8 to accumulate in the cooling case 2. That is, when the bubbles 10 are contained in the refrigerant 10 introduced into the cooling case 2 from the refrigerant introduction pipe 4, the bubbles 8 are lighter than the refrigerant 10, so that they rise and come into contact with the lower surface 220 of the upper wall plate 22. As the refrigerant 10 flows, the bubbles 8 move downstream along the lower surface 220 of the upper wall plate 22 and reach the vicinity of the outlet-side opening end 50. In this example, since the upper end edge 51 of the outlet side opening end portion 50 is located above the lower surface 220 of the upper wall plate 22, the bubbles 8 can enter the refrigerant outlet tube 5 while floating as they are.
Here, as shown in FIG. 10, if the upper end edge 931 of the outlet-side opening end 930 is positioned below the lower surface 970 of the upper wall plate 97, the bubble 98 cannot easily move downward. 98 cannot be discharged. Therefore, the bubbles 98 are likely to accumulate on the lower surface 970 of the upper wall plate 97. On the other hand, in this example, as shown in FIG. 3, the upper end edge 51 of the outlet-side opening end 50 is positioned above the lower surface 220 of the upper wall plate 22, so that the bubbles 8 enter the refrigerant outlet pipe 5. You can enter easily. For this reason, the bubbles 8 are less likely to accumulate in the cooling case 2. Thereby, the fall of the cooling efficiency of the semiconductor module 3 can be suppressed.

Further, as shown in FIG. 3, the inlet side opening end portion 40 that is the end portion of the refrigerant introduction pipe 4 that opens to the case internal space S has an upper end edge 41 that is higher than the lower surface 220 of the upper wall plate 22. positioned.
In this way, even if the bubbles 10 are included in the refrigerant 10 introduced from the refrigerant introduction pipe 4, the lower surface 220 of the upper wall plate 22 is positioned below the upper end edge 41 of the introduction side opening end 40. Therefore, the bubbles 8 are less likely to enter the space S in the case. This makes it easier to prevent bubbles 8 from accumulating in the cooling case 2.

As shown in FIG. 4, in this example, the sealing module 31 is in close contact with the upper wall plate 22, so that the semiconductor module 3 and the upper wall plate 22 are integrated.
If it does in this way, since the semiconductor module 3 and the upper wall board 22 can be united, a number of parts can be reduced and it becomes possible to reduce the manufacturing cost of the power converter device 1. FIG.

  As described above, according to this example, it is possible to provide the power conversion device 1 in which the bubbles 8 included in the refrigerant 10 are less likely to accumulate in the cooling case 2.

( Reference Example 2)
In this example, the shape of the cooling case 2 is changed. As shown in FIGS. 5 and 6, the power conversion device 1 of the present example includes an air inflow prevention unit that prevents the bubbles 8 from flowing into the case inner space S at the upper end of the side wall 21 a to which the refrigerant introduction pipe 4 is attached. 7 is provided. The air inflow prevention portion 7 extends obliquely downward from the upper end portion of the side wall 21 toward the case inner space S, and its lower end 70 is an end portion of the refrigerant introduction pipe 4 that is open to the case inner space S. It is located below the upper edge 41 of the side opening end 40.

As shown in FIG. 5, the air inflow prevention part 7 is formed over the entire longitudinal direction X of the side wall 21a. Further, as shown in FIG. 6, the air inflow prevention portion 7 includes a tapered portion 72 extending obliquely downward from the upper end portion of the side wall 21a toward the case internal space S, and a horizontal portion extending from the tapered portion 72 toward the side wall 21b. 73. On the horizontal portion 73, the upper wall plate 22 is placed.
In addition, the same configuration as the reference example 1 is provided.

The effect of this example will be described. With the above configuration, the bubbles 8 accumulate between the introduction side opening end portion 40 and the lower end 70 of the air inflow prevention portion 7, so that the bubbles 8 can be prevented from entering downstream from the air inflow prevention portion 7. This makes it easier to prevent the bubbles 8 from accumulating in the cooling case 2.
In addition, the same effects as those of Reference Example 1 are provided.

(Example 1 )
In this example, the shape of the upper wall plate 22 is changed. As shown in FIG. 7, in this example, an air escape groove 25 that is recessed upward is formed on the lower surface 220 of the upper wall plate 22.
That is, as shown in FIG. 7, the upper wall plate 22 includes a central portion 23 having a lower surface 220 projecting downward, and a thin peripheral portion 24 formed around the central portion 23. A gap surrounded by the portion 24 and the side wall 21 serves as an air escape groove 25.
In addition, as shown in FIGS. 7 and 8, the cooling fin 6 is connected to the lower surface 220 of the central portion 23. The air escape groove 25 is formed so as to surround the four sides of the central portion 23.
In addition, the same configuration as the reference example 1 is provided.

The effect of this example will be described.
With the above configuration, the effect of the present invention that the bubbles 8 contained in the refrigerant 10 are less likely to accumulate in the cooling case 2 can be effectively exhibited. That is, by forming the air escape groove 25, as shown in FIG. 8, the bubbles 8 that have entered the case together with the refrigerant 10 from the refrigerant introduction pipe 4 can be guided to the air escape groove 25. Therefore, when the cooling fin 6 exists, it becomes difficult for the bubble 8 to adhere to the clearance gap between the cooling fin 6 and the upper wall board 22, and it can suppress that the cooling efficiency of the semiconductor module 3 falls. Further, since the bubbles 8 entering the air escape groove 25 move downstream with the flow of the refrigerant 10, they can be easily discharged out of the case from the refrigerant outlet pipe 5.
In addition, the same effects as those of Reference Example 1 are provided.

( Reference Example 3 )
In this example, the structure of the cooling case 2 is changed. As shown in FIG. 9, in this example, the cooling fins 6 are not provided in the cooling case 2.
In addition, the same configuration as the reference example 1 is provided.

In the case of this example, since the cooling fin 6 does not exist in the cooling case 2, the problem that the cooling efficiency of the semiconductor module 3 is lowered due to the bubbles 8 adhering to the gap between the cooling fin 6 and the upper wall plate 22 is solved. it can. Further, even when the bubbles 8 come into contact with the lower surface 220 of the upper wall plate 22, the lower surface 220 is flat without any irregularities, so that the bubbles 8 easily move downstream with the flow of the refrigerant 10. Therefore, the bubbles 8 can be easily discharged out of the case.
In addition, the same effects as those of Reference Example 1 are provided.

DESCRIPTION OF SYMBOLS 1 Power converter 10 Refrigerant 20 Bottom wall 21 Side wall 22 Upper wall board 3 Semiconductor module 4 Refrigerant inlet pipe 5 Refrigerant outlet pipe 50 Outlet opening end 51 (upper outlet opening end) upper edge S Case inner space

Claims (4)

A cooling case comprising a bottom wall, a side wall erected upward from the peripheral edge of the bottom wall, and a metal upper wall plate attached to the upper end of the side wall;
A semiconductor module comprising a power conversion circuit and a sealing portion that seals the semiconductor element, and is disposed on the upper surface of the upper wall plate; and
A refrigerant inlet pipe and a refrigerant outlet pipe provided on the side wall,
The refrigerant is introduced from the refrigerant introduction pipe into the space in the case surrounded by the bottom wall, the side wall, and the upper wall board, and the refrigerant is led out from the refrigerant outlet pipe to be arranged on the upper wall board. The semiconductor module is configured to be cooled with the refrigerant,
The outlet opening end of the refrigerant outlet pipe, which is the end opened to the space in the case, has an upper end edge located above the lower surface of the upper wall plate ,
A power conversion device, wherein an air escape groove recessed upward is formed in the lower surface of the upper wall plate. Oite to claim 1, by which the sealing portion is in close contact with the upper wall panel, the power converter in which the semiconductor module and the upper wall plate and is characterized in that it is integral. 3. The introduction side opening end of the refrigerant introduction pipe, which is the end of the refrigerant introduction pipe that opens into the space in the case, has an upper end edge positioned above the lower surface of the upper wall plate. A power conversion device characterized by that. In any one of Claims 1-3 , the air inflow prevention part which prevents that a bubble flows in into the space in the said case is provided in the upper end part of the said side wall which attached the said refrigerant | coolant inlet tube, The air inflow prevention portion extends obliquely downward from the upper end portion of the side wall toward the case inner space, and the lower end of the air inflow prevention portion is an introduction side opening end that is an end portion of the refrigerant introduction pipe that opens into the case inner space. The power converter device is located below the upper end edge of the unit.

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