JP5114967B2 - Cooling device and semiconductor power conversion device - Google Patents

Description

  The present invention relates to a cooling device and a semiconductor power conversion device, and is particularly suitable when applied to a cooling body that cools a heating element by forcibly flowing a refrigerant.

In a semiconductor power conversion device such as an inverter, in order to efficiently cool the semiconductor elements constituting the semiconductor power conversion device, a coolant is forced to flow through a cooling body to which the semiconductor elements are attached. Yes.
Further, for example, in Patent Document 1, in a boiling cooling type semiconductor device, a refrigerant is boiled on the surface of a cooling body, heat generated from a heat generating component is transferred as vaporization heat, and bubbles of refrigerant vapor are buoyant. A method of dissipating and dissipating heat is disclosed. And in invention disclosed by patent document 1, by forming a dentition hole in a cooling body, the effective heat-transfer area between a cooling body and a refrigerant | coolant is increased, and a heat-transfer surface is carried out by the refrigerant | coolant flow which flows upward. It is possible to improve the effect of boiling cooling by improving the bubble breakage of the bubbles.

Further, for example, Patent Document 2 discloses a method of regularly arranging protrusions having a predetermined cross-sectional shape whose cross-sectional sides are inclined on the heat transfer surface of the cooling fin by alternately meandering left and right.
Japanese Patent No. 2562180 JP 2006-1000029 A

However, in the method disclosed in Patent Document 1, since the heat-generating component and the cooling body are immersed in the refrigerant sealed in the pressure vessel, the power converter is increased in size and the cooling body is provided in the power converter. There is a problem that the refrigerant flow path formed in the above must be arranged in the vertical direction.
Further, in the method disclosed in Patent Document 2, since a sealing material such as an O-ring, an adhesive, and a gasket is used to attach the power module to the cooling fin, assembly when the power module and the cooling fin are attached is complicated. There is a problem in that maintenance of the sealing material is necessary because the cost is increased and the refrigerant leaks.
Then, the objective of this invention is providing the cooling device and semiconductor power converter device which can improve the cooling efficiency by a cooling body, suppressing the enlargement of a power converter.

In order to solve the above-described problem, according to the cooling device according to claim 1, the cooling body that dissipates heat generated from the heating element by heat conduction and the internal threading of the cooling body so that they are parallel to each other. and arranged plurality of female screw holes which are formed by the intermediate flow path connecting an end portion of the female screw hole adjacent a refrigerant passage for flowing forced through a coolant, forced circulation of the coolant before Symbol coolant channel And a radiator that radiates heat received by the refrigerant from the heating element.

The cooling device according to claim 2 is characterized in that the plurality of cooling bodies are connected in series or in parallel to the pump.
In the cooling device according to claim 3, the intermediate flow path is formed from the outside of the cooling body, and an open end of the intermediate flow path is sealed with a sealing material. .

According to the semiconductor power conversion device of claim 4 , the semiconductor element, the cooling element that disposes the semiconductor element on the surface, dissipates heat generated from the semiconductor element by heat conduction, and the cooling element. a plurality of female screw holes are tapping arranged so as to be parallel with each other, formed by the intermediate flow path connecting an end portion of the female screw hole adjacent a refrigerant passage for flowing forced through the coolant, before Symbol A pump that forcibly circulates the refrigerant in the refrigerant flow path, and a radiator that radiates heat received from the semiconductor element by the refrigerant are provided.

  As described above, according to the present invention, the dentition structure is formed on the inner wall surface of the refrigerant flow path for forcibly flowing the refrigerant in the cooling body, so that the refrigerant flow path is arranged in the vertical direction. Turbulent flow can be formed in the vicinity of the flow path surface, preventing laminar flow from forming on the inner wall surface of the flow path, and smoothing the heat flow from the cooling body to the main flow. In addition, in order to transfer the heat generated from the heating element to the refrigerant, it is not necessary to immerse the heating element and the cooling element in the refrigerant. It becomes possible to improve cooling efficiency.

Hereinafter, a cooling device according to an embodiment of the present invention will be described with reference to the drawings.
1A is a cross-sectional view showing a schematic configuration of the cooling device according to the first embodiment of the present invention, FIG. 1B is a front view showing the schematic configuration of the cooling device of FIG. 1 (c) is an enlarged cross-sectional view showing a refrigerant flow path of the cooling device of FIG. 1 (a), and FIG. 2 is a perspective view showing a schematic configuration of the sealing material of FIG.

In FIG. 1, refrigerant flow paths 2 a, 2 b, and 3 for forcibly flowing a refrigerant are provided in a cooling body 1. Here, the refrigerant flow paths 2a and 2b are arranged so as to be parallel to each other, and the refrigerant flow path 3 is arranged at an end of the refrigerant flow paths 2a and 2b so as to be orthogonal to the refrigerant flow paths 2a and 2b. .
The refrigerant channel 2a is connected to the refrigerant inlet, the refrigerant channel 2b is connected to the refrigerant outlet, and the ends of the refrigerant channels 2a and 2b are connected to the refrigerant channel 3 serving as an intermediate channel. Yes. The open end of the refrigerant flow path 3 is sealed with a sealing material 4. In addition, as a material of the cooling body 1, high heat conductive materials, such as copper and aluminum, can be used, for example.

  Here, the dentition structure 5 that generates turbulent flow is formed on the inner wall surfaces of the refrigerant flow paths 2a, 2b, and 3 on the inner wall surfaces of the refrigerant flow paths 2a, 2b, and 3. 2b and 3 can be arranged along the flow direction of the refrigerant flowing therethrough. In addition, as the dentition structure 5, the internal thread hole formed along the flow direction of a refrigerant | coolant may be sufficient, and the dentition of an internal gear may be sufficient as it, for example. In addition, as the refrigerant flowing through the refrigerant flow paths 2a, 2b, and 3, water or a refrigerant other than water, for example, chlorofluorocarbon or fluorocarbon can be used.

Moreover, as a material of the sealing material 4, high heat conductive materials, such as copper and aluminum, can be used, for example. And as shown in FIG. 2, you may make it form a dentition structure in the contact surface of the sealing material 4 and a refrigerant | coolant, in order to promote the production | generation of a turbulent flow.
A heating element such as a semiconductor switching element can be attached to the surface of the cooling body 1. In addition, as a semiconductor switching element, you may make it use power MOSFET, a bipolar transistor, etc. other than IGBT (Insulated Gate Bipolar Transistor: Insulated Gate Bipolar Transistor), for example.

  Then, the refrigerant introduced into the cooling body 1 via the refrigerant flow path 2a is guided to the refrigerant flow path 2b via the refrigerant flow path 3 and discharged out of the cooling body 1 via the refrigerant flow path 2b. . In addition, as a method of forcibly flowing the refrigerant through the refrigerant flow paths 2a, 2b, and 3, for example, a pump for circulating the refrigerant can be used. Here, the heat generated from the heating element attached to the surface of the cooling body 1 is transmitted to the refrigerant flowing through the refrigerant flow paths 2 a, 2 b and 3 via the cooling body 1. The heat transfer to the refrigerant is performed by heat conduction between the inner wall surfaces of the refrigerant flow paths 2a, 2b, and 3 and the refrigerant and heat transfer by convection in the refrigerant.

  Here, the amount of heat Q transferred by forced convection can be expressed by Q = A × hm × (Tf−Tw). However, A is the area where the cooling body 1 and the refrigerant are in contact, hm is the average heat transfer coefficient between the cooling body 1 and the refrigerant, Tf is the temperature of the cooling body 1, and Tw is the temperature of the refrigerant. Since the temperature Tf of the cooling body 1 can be expressed by Tf = Tw + (Q / (A × hm)), in order to lower the temperature Tf of the cooling body 1, that is, to improve the cooling performance, the cooling body 1 What is necessary is just to enlarge the area which 1 and a refrigerant | coolant contact, or to enlarge the average heat transfer coefficient hm between the cooling body 1 and a refrigerant | coolant.

  On the other hand, there are laminar flow and turbulent flow in the refrigerant flow state. When the surface of the flow path is smooth, a main flow that flows through the center of the flow path is formed, and a smooth and undisturbed laminar flow is formed along the inner wall surface of the flow path due to the viscosity of the refrigerant. It is formed. When a laminar flow is formed along the inner wall surface of the flow path, the heat flow from the cooling body 1 to the main flow is hindered, and the heat transfer performance of the cooling body 1 is deteriorated.

  Here, the dentition structure 5 is formed on the inner wall surfaces of the refrigerant flow paths 2a, 2b, and 3, and the refrigerant is forced to flow through the refrigerant flow paths 2a, 2b, and 3 so that the refrigerant flow paths 2a, 2b, 3 A turbulent flow can be generated on the inner wall surface, and the formation of a laminar flow along the inner wall surfaces of the refrigerant flow paths 2a, 2b, 3 can be inhibited. For this reason, the refrigerant whose temperature has risen due to heat transfer from the inner wall surfaces of the refrigerant flow paths 2a, 2b, and 3 is quickly mixed with the main flow by the turbulent flow generated in the vicinity of the inner wall surfaces of the refrigerant flow paths 2a, 2b, and 3. Since the movement of heat from the inner wall surfaces of the refrigerant flow paths 2a, 2b, and 3 to the refrigerant is promoted, the cooling body 1 can be compared with the case where the inner wall surfaces of the refrigerant flow paths 2a, 2b, and 3 are flat. Heat transfer performance can be improved.

Further, by forming the dentition structure 5 on the inner wall surfaces of the refrigerant flow paths 2a, 2b, and 3, the contact area with the refrigerant is expanded as compared with the case where the inner wall surfaces of the refrigerant flow paths 2a, 2b, and 3 are flat. Since the heat transfer area can be increased, the cooling performance of the cooling body 1 can be improved.
Further, the cooling body 1 is arranged so that the refrigerant flow paths 2a, 2b, 3 are oriented in the vertical direction by forcibly flowing the refrigerant into the refrigerant flow paths 2a, 2b, 3 in which the dentition structure 5 is formed. There is no need, and restrictions on the arrangement of the cooling body 1 can be reduced. Further, the refrigerant flow paths 2a, 2b, and 3 need not be linear.

  Further, in a power converter such as an inverter, a heating element such as a semiconductor module on which a semiconductor switching element is mounted can be attached to the cooling body 1 without requiring a special member or process, thereby simplifying assembly. And the size of the apparatus can be reduced. Further, the processing parts other than the refrigerant inlet and the refrigerant outlet can completely seal the cooling body 1 without using an O-ring and the like, and there is no risk of refrigerant leakage, so that maintenance of the sealing material is unnecessary. can do.

  In addition, as a method of manufacturing the cooling body 1 of FIG. 1, for example, a female screw hole that becomes the refrigerant flow path 2a is formed in the copper plate by a female screw process. And the female screw hole used as the refrigerant flow path 2b arrange | positioned in parallel with the refrigerant flow path 2a is formed in a copper plate by internal thread processing. Further, an internal thread hole to be the coolant path 3 is formed in the copper plate by an internal thread process so as to be in contact with the ends of the coolant paths 2a and 2b. Then, the opening end of the refrigerant flow path 3 is sealed with a sealing material 4. In addition, as a method of attaching the sealing material 4 to the cooling body 1, brazing can be used, for example.

FIG. 3A is a cross-sectional view showing a schematic configuration of the cooling device according to the second embodiment of the present invention, FIG. 3B is a front view showing the schematic configuration of the cooling device of FIG. 3 (c) is a back view showing a schematic configuration of the cooling device of FIG. 3 (a), and FIG. 3 (d) is a cross-sectional view showing an enlarged refrigerant flow path of the cooling device of FIG. 3 (a). .
In FIG. 3, refrigerant flow paths 12 a to 12 d and 13 a to 13 c that forcibly flow the refrigerant are provided in the cooling body 11. Here, the refrigerant flow paths 12a to 12d are arranged so as to be parallel to each other, and the refrigerant flow path 13a is arranged so as to be orthogonal to the refrigerant flow paths 12a and 12b at the ends of the refrigerant flow paths 12a and 12b. The flow path 13b is disposed so as to be orthogonal to the refrigerant flow paths 12ba and 12c at the ends of the refrigerant flow paths 12c and 12c, and the refrigerant flow path 13c is arranged at the ends of the refrigerant flow paths 12c and 12d. It is arranged so as to be orthogonal to 12d.

  The refrigerant channel 12a is connected to the refrigerant inlet, the refrigerant channel 12d is connected to the refrigerant outlet, and the ends of the refrigerant channels 12a and 12b are connected to the refrigerant channel 13a serving as an intermediate channel, The ends of the refrigerant channels 12b and 12c are connected by a refrigerant channel 13b serving as an intermediate channel, and the ends of the refrigerant channels 12c and 12d are connected by a refrigerant channel 13c serving as an intermediate channel. The open end of the refrigerant flow path 13a is sealed with a sealing material 14a, the open end of the refrigerant flow path 13b is sealed with a sealing material 14b, and the open end of the refrigerant flow path 13c is sealed with a sealing material 14c. It is sealed with.

In addition, as a material of sealing material 14a-14c, high heat conductive materials, such as copper and aluminum, can be used, for example. And as shown in FIG. 2, you may make it form a dentition structure in the contact surface of sealing material 14a-14c and a refrigerant | coolant, in order to promote the production | generation of a turbulent flow.
Here, a dentition structure 15 that generates turbulent flow on the inner wall surfaces of the refrigerant flow paths 12a to 12d is formed on the inner wall surfaces of the refrigerant flow paths 12a to 12d, and the dentition passes through the refrigerant flow paths 12a to 12d. It can arrange along the flow direction of the flowing refrigerant.

A heating element such as a semiconductor switching element can be attached to the surface of the cooling body 11. Then, the refrigerant introduced into the cooling body 11 via the refrigerant flow path 12a is guided to the refrigerant flow path 12b via the refrigerant flow path 13a, and further flows through the refrigerant flow path 12b and then passes through the refrigerant flow path 13b. To the refrigerant flow path 12c, and further passed through the refrigerant flow path 12c, then led to the refrigerant flow path 12d via the refrigerant flow path 13c, and further passed through the refrigerant flow path 12d and then to the outside of the cooling body 11 Discharged. The heat generated from the heating element attached to the surface of the cooling body 11 is transmitted to the refrigerant flowing through the refrigerant flow paths 12 a to 12 d via the cooling body 11.
Here, by providing the refrigerant flow paths 12a to 12d in the cooling body 11, the heat transfer area can be doubled compared to the cooling body 11 of FIG. 1, so the cooling performance is doubled. Can be improved.

FIG. 4 is a plan view showing a schematic configuration of a semiconductor power conversion device according to the third embodiment of the present invention.
In FIG. 4, the power converter 21 is provided with a semiconductor module 23 on which a semiconductor element is mounted, and the semiconductor module 23 is mounted on a cooling body 22. The power converter 21 includes a gate control circuit and a snubber circuit for controlling the pulse width input to the gate of the semiconductor element, but these are omitted in the example of FIG.
Here, as the cooling body 22, the structure of FIG. 1 or FIG. 3 can be used, for example. The cooling body 22 is connected to the pump 24 and the radiator 25 via the refrigerant circulation pipe 26.

  Then, the refrigerant sent out to the refrigerant circulation pipe 26 by the pump 24 enters the cooling body 22 from the refrigerant inlet of the cooling body 22. The heat generated from the semiconductor module 23 attached to the surface of the cooling body 22 is transmitted to the refrigerant flowing through the cooling body 22, and the temperature of the refrigerant rises. Then, the refrigerant whose temperature rises in the cooling body 22 is discharged from the refrigerant outlet of the cooling body 22 to the refrigerant circulation pipe 26 and sent to the radiator 25. The refrigerant sent to the radiator 25 is cooled by the radiator 25 and sent out again into the cooling body 22 through the refrigerant circulation pipe 26.

Thereby, while allowing the pump 24 and the radiator 25 to be installed outside the power converter 21, the refrigerant can be forced to flow in the refrigerant flow path in which the dentition structure is formed. The semiconductor module 23 can be efficiently cooled while downsizing 21.
FIG. 5 is a plan view showing a schematic configuration of a semiconductor power conversion device according to the fourth embodiment of the present invention.

  In FIG. 5, the power converters 31a and 31b are provided with semiconductor modules 33a and 33b on which semiconductor elements are mounted, respectively, and the semiconductor modules 33a and 33b are mounted on the cooling bodies 32a and 32b, respectively. The power converters 31a and 31b include a gate control circuit and a snubber circuit for controlling the pulse width input to the gate of the semiconductor element, but these are omitted in the example of FIG. .

Here, as the cooling bodies 32a and 32b, for example, the configuration of FIG. 1 or FIG. 3 can be used, respectively. The cooling bodies 32a and 32b are connected in series to the pump 34 and the radiator 35 via the refrigerant circulation pipes 36a and 36b.
That is, the refrigerant outlet of the cooling body 32a is connected to the refrigerant inlet of the radiator 35 via the refrigerant circulation pipe 36a, and the refrigerant inlet of the cooling body 32b is connected to the refrigerant outlet of the pump 34 via the refrigerant circulation pipe 36a. The refrigerant inlet of the body 32a and the refrigerant outlet of the cooling body 32b are connected to each other via a refrigerant circulation pipe 36b.

The refrigerant sent out to the refrigerant circulation pipe 36a by the pump 34 enters the cooling body 32b from the refrigerant inlet of the cooling body 32b. The heat generated from the semiconductor module 33b attached to the surface of the cooling body 32b is transmitted to the refrigerant flowing through the cooling body 32b, and the temperature of the refrigerant rises. The refrigerant whose temperature has risen in the cooling body 32b is discharged from the refrigerant outlet of the cooling body 32b to the refrigerant circulation pipe 36b and enters the cooling body 32a from the refrigerant inlet of the cooling body 32a. The heat generated from the semiconductor module 33a attached to the surface of the cooling body 32a is transmitted to the refrigerant flowing through the cooling body 32a, and the temperature of the refrigerant further increases. The refrigerant whose temperature has further increased in the cooling body 32 a is discharged from the refrigerant outlet of the cooling body 32 a to the refrigerant circulation pipe 36 a and sent to the radiator 35. Then, the refrigerant sent to the radiator 35 is cooled by the radiator 35 and sent out again into the cooling body 32b through the refrigerant circulation pipe 36a.
Thereby, by using one pump 34 and one radiator 35, it becomes possible to cool the plurality of power converters 31a and 31b while preventing the temperature of the semiconductor modules 33a and 33b from exceeding an allowable value. Therefore, it is possible to reduce the size of the semiconductor power conversion device.

FIG. 6 is a plan view showing a schematic configuration of a semiconductor power conversion device according to the fifth embodiment of the present invention.
In FIG. 6, power converters 41a and 41b are provided with semiconductor modules 43a and 43b on which semiconductor elements are mounted, and the semiconductor modules 43a and 43b are respectively mounted on the cooling bodies 42a and 42b. The power converters 41a and 41b each include a gate control circuit and a snubber circuit for controlling the pulse width input to the gate of the semiconductor element, but these are omitted in the example of FIG. .

Here, as the cooling bodies 42a and 42b, for example, the configuration of FIG. 1 or FIG. 3 can be used, respectively. The cooling bodies 42a and 42b are connected in parallel to the pump 44 and the radiator 45 through the refrigerant circulation pipes 46a to 46c.
That is, the refrigerant outlets of the cooling bodies 42a and 42b are connected to the refrigerant inlet of the radiator 45 via the refrigerant circulation pipes 46a and 46b, respectively, and the refrigerant inlets of the cooling bodies 42a and 42b are respectively connected via the refrigerant circulation pipes 46c and 46a. The refrigerant outlet of the pump 44 is connected.

  The refrigerant sent out to the refrigerant circulation pipes 46a and 46c by the pump 34 enters the cooling bodies 42b and 42a from the refrigerant inlets of the cooling bodies 42b and 42a, respectively. The heat generated from the semiconductor modules 43a and 43b attached to the surfaces of the cooling bodies 42b and 42a is transferred to the refrigerant flowing through the cooling bodies 42b and 42a, respectively, and the temperature of the refrigerant rises. The refrigerant whose temperature has risen in the cooling bodies 42b and 42a is discharged from the refrigerant outlets of the cooling bodies 42b and 42a to the refrigerant circulation pipes 46a and 46b, respectively, and sent to the radiator 45. The refrigerant sent to the radiator 45 is cooled by the radiator 45 and sent out again into the cooling bodies 42b and 42a via the refrigerant circulation pipes 46a and 46c, respectively.

  Thereby, by using one pump 44 and one radiator 45, it becomes possible to cool the plurality of power converters 41a and 41b while preventing the temperature of the semiconductor modules 43a and 43b from exceeding an allowable value. Thus, it is possible to reduce the size of the semiconductor power conversion device, and it is possible to facilitate the management of the amount of refrigerant circulated in the cooling bodies 42a and 42b.

1A is a cross-sectional view showing a schematic configuration of the cooling device according to the first embodiment of the present invention, FIG. 1B is a front view showing the schematic configuration of the cooling device of FIG. 1 (c) is an enlarged cross-sectional view showing a refrigerant flow path of the cooling device of FIG. It is a perspective view which shows schematic structure of the sealing material of FIG. FIG. 3A is a cross-sectional view showing a schematic configuration of the cooling device according to the second embodiment of the present invention, FIG. 3B is a front view showing the schematic configuration of the cooling device of FIG. 3 (c) is a back view showing a schematic configuration of the cooling device of FIG. 3 (a), and FIG. 3 (d) is a cross-sectional view showing an enlarged refrigerant flow path of the cooling device of FIG. 3 (a). . It is a top view which shows schematic structure of the semiconductor power converter device which concerns on 3rd Embodiment of this invention. It is a top view which shows schematic structure of the semiconductor power converter device which concerns on 4th Embodiment of this invention. It is a top view which shows schematic structure of the semiconductor power converter device which concerns on 5th Embodiment of this invention.

Explanation of symbols

1, 11, 22, 32a, 32b, 42a, 42b Cooling bodies 2a, 2b, 3, 12a-12d, 13a-13c Refrigerant flow path 4, 14a-14c Sealing material 5, 15 Teeth structure 21, 31a, 31b , 41a, 41b Power converter 23, 33a, 33b, 43a, 43b Semiconductor module 24, 34, 44 Pump 25, 35, 45 Radiator 26, 36a, 36b, 46a-46c Refrigerant circulation piping

Claims (4)

A cooling body that dissipates heat generated by the heating element by heat conduction;
Refrigerant flow path formed by a plurality of female screw holes that are internally threaded and arranged in parallel with each other in the cooling body, and an intermediate flow path that connects the ends of the adjacent female screw holes , for forcibly flowing the refrigerant When,
A pump for forcibly circulating the refrigerant in the refrigerant flow path;
A cooling device comprising: a radiator that radiates heat received by the refrigerant from the heating element.   The cooling device according to claim 1, wherein a plurality of the cooling bodies are connected in series or in parallel to the pump. The cooling apparatus according to claim 1 or 2, wherein the intermediate flow path is formed from the outside of the cooling body, and an open end of the intermediate flow path is sealed with a sealing material . A semiconductor element;
A cooling body in which the semiconductor element is disposed on a surface and dissipates heat generated from the semiconductor element by heat conduction;
Refrigerant flow path formed by a plurality of female screw holes that are internally threaded and arranged in parallel with each other in the cooling body, and an intermediate flow path that connects the ends of the adjacent female screw holes , for forcibly flowing the refrigerant When,
A pump for forcibly circulating the refrigerant in the refrigerant flow path;
A semiconductor power conversion device comprising: a radiator that radiates heat received from the semiconductor element by the refrigerant.

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