JP2017011923A - Power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that can use a smaller insulating plate than a metal plate, and enhance the sealing performance between the opening of a cooling unit and the metal plate without inducing flexure of the metal plate.SOLUTION: A conductive heat radiation plate is exposed to a surface facing a cooling unit of a semiconductor module. Each cooling unit has a main body, a gasket and a metal plate. The main body has an opening on a side surface thereof which faces the semiconductor module. The gasket is arranged so as to surround the opening. One surface of the metal plate closes the opening through the gasket. Sealing between the opening and the metal plate is secured by the pressing force of the elastic member. An insulating plate for insulating the heat radiation plate and the metal plate is sandwiched between the metal plate and the semiconductor module. Ridges extending along the edge of the insulating plate are provided on both sides of the insulating plate on the other side of the metal plate. When viewed from the lamination direction, the gasket overlaps the semiconductor module, and the ridges overlap a part of the gasket. The top surfaces of the ridges are in contact with the semiconductor module.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power conversion device including a power unit in which a plurality of card-type semiconductor modules containing semiconductor elements and a plurality of coolers are alternately stacked one by one.

  For example, a power conversion device that supplies power to a large-capacity motor includes a plurality of semiconductor elements that generate a large amount of heat. As one of structures for efficiently cooling a plurality of semiconductor elements, a power conversion apparatus may include a power unit in which a card-type semiconductor module that houses semiconductor elements is sandwiched between a pair of coolers. Furthermore, in order to efficiently cool a plurality of semiconductor modules, a power converter including a power unit in which a plurality of semiconductor modules and a plurality of coolers are alternately stacked one by one is known (for example, Patent Documents 1 and 2). . Since the power unit cools the card-type semiconductor module from both sides, the cooling efficiency is high. The power conversion device of Patent Document 2 includes an elastic member that pressurizes the power unit in the stacking direction of the semiconductor module and the cooler in order to increase the adhesion between the semiconductor module and the cooler to further increase the cooling efficiency.

JP2013-121236A JP 2012-231591 A

  The applicant of the present application has proposed to adopt a cooler composed of a main body having an opening and a metal plate that closes the opening for the power unit (Japanese Patent Application No. 2014-083469, filed on April 15, 2014, Not disclosed at the time of filing this application). The cooler can be made of a resin body, has excellent mass productivity, and is lightweight. The cooler has the following structure. The cooler includes a main body, a metal plate, and a gasket. The main body is provided with a flow path through which a coolant flows, and an opening communicating with the flow path is provided on a side surface facing the semiconductor module. The gasket is arranged on the side surface around the opening so as to surround the opening when viewed from the stacking direction of the semiconductor module and the cooler. One side of the metal plate closes the opening with a gasket interposed therebetween, and the other side faces the semiconductor module. That is, one surface of the metal plate faces the flow path, and the other surface faces the semiconductor module. In addition, the conductive heat sink which is electrically connected to the semiconductor element is exposed on the surface of the semiconductor module facing the cooler. Therefore, an insulating plate that electrically insulates the heat radiating plate and the metal plate is sandwiched between the metal plate and the semiconductor module. The power converter includes a power unit in which the above-described cooler and semiconductor module are stacked, and an elastic member that pressurizes the power unit in the stacking direction. In the cooler described above, sealing between the opening and the metal plate is ensured by the pressure applied by the elastic member. Even if the main body of the cooler is made of, for example, a resin having low thermal conductivity, the heat of the semiconductor module is efficiently absorbed by the refrigerant in the cooler through the metal plate.

  From the viewpoint of cooling efficiency, it is preferable that the opening, which is a range in which the metal plate and the refrigerant are in direct contact with each other, be large. However, if the opening is enlarged, a metal plate having a larger surface area is required for sealing the opening. On the other hand, it is sufficient for the insulating plate sandwiched between the metal plate and the semiconductor module to ensure a size (surface area) that can insulate the heat radiating plate and the metal plate. However, if an insulating plate having a surface area smaller than that of the metal plate is sandwiched between the metal plate and the semiconductor module, a gap is generated on both sides of the insulating plate. A portion of the metal plate that faces the gap is not supported by the semiconductor module. For this reason, when viewed from the stacking direction, a part of the gasket may overlap the gap. Since the portion of the metal plate that faces the gap is not supported by the semiconductor module, the metal plate may be bent by the reaction force of the gasket. As a result, the sealing between the opening and the metal plate may be weakened.

  The present specification provides a technique that can use an insulating plate smaller than the metal plate and can improve the sealing property (watertightness) between the opening of the cooler and the metal plate without the metal plate being bent. .

  The power converter disclosed in this specification includes the above-described power unit and an elastic member. Attention is now paid to a pair of coolers adjacent to each other with one semiconductor module interposed therebetween. In the power conversion device disclosed in the present specification, protrusions extending along the edge of the insulating plate are provided on both sides of the insulating plate on the surface of the metal plate facing the semiconductor module (that is, the other surface). ing. When viewed from the stacking direction, the gasket overlaps the semiconductor module, and the protrusions overlap a part of the gasket. Further, the top surface of the ridge is in contact with the semiconductor module. Here, “the top surface of the ridge is in contact with the semiconductor module” means that the top surface of the ridge and the semiconductor module are in direct contact with each other, and is in contact with the elastic cushioning material in between. Including both.

  In said power converter device, the protruding item | line extended along the edge of an insulating board is provided in the both sides of the insulating board. In other words, the insulating plate may be of a size (surface area) that fits between the ridges. Therefore, in said power converter device, an insulating board with a smaller surface area than a metal plate can be used. Further, in the above power conversion device, when viewed from the stacking direction, the ridge overlaps a part of the gasket, but the top surface of the ridge contacts the semiconductor module. Therefore, even when an insulating plate having a smaller surface area than that of the metal plate is used, all portions of the metal plate that receive the reaction force of the gasket are supported by the semiconductor module. Therefore, the metal plate does not bend due to the reaction force of the gasket, and the sealing performance between the opening and the metal plate can be improved. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a top view of the power converter device (inverter) of the 1st example. It is a perspective view of the power unit of 1st Example. It is a partial exploded perspective view of the power unit of 1st Example. It is a disassembled perspective view of the semiconductor module of 1st Example, an insulating plate, and a metal plate. It is a schematic diagram which shows the positional relationship of a metal plate, a gasket, and a semiconductor module when it sees from a lamination direction. It is the figure which cut the laminated body of a semiconductor module pinched | interposed between a pair of cooler and them in the cross section equivalent to the VI-VI line of FIG. It is the figure which cut the laminated body of a semiconductor module pinched | interposed between a pair of cooler and them in the cross section corresponded to the VII-VII line of FIG. It is a disassembled perspective view which shows the semiconductor module of 2nd Example, an insulating plate, and a metal plate.

(First embodiment)
The power conversion apparatus according to the present embodiment will be described with reference to the drawings. The power conversion device of this embodiment is an inverter 100 that is mounted on an electric vehicle, converts DC power of a battery into AC power, and supplies the AC power to a traveling motor. Inverter 100 includes a booster circuit that boosts the DC power of the battery and an inverter circuit that converts DC to AC. Since the booster circuit and the inverter circuit are well known, description of the circuit configuration is omitted.

  FIG. 1 shows a plan view of the inverter 100. FIG. 1 is a plan view of the inverter 100 with the upper cover removed, and shows a component layout inside the housing 53.

  The inverter 100 houses a power unit 10, a reactor 55, two capacitors 56, and a control board (not shown) in a housing 53. The reactor 55 is a component of the booster circuit. The two capacitors 56 are connected in parallel to the input side and the output side of the booster circuit, respectively, and smooth the current. A control board (not shown) is disposed on the power unit 10.

  The power unit 10 is a unit in which a plurality of coolers 2a-2d and a plurality of semiconductor modules 3a-3d are alternately stacked one by one. Each of the semiconductor modules 3a to 3d accommodates a power transistor that is a semiconductor element. Although a detailed description of the structure is omitted, two power transistors are accommodated in one semiconductor module. The power unit 10 includes four semiconductor modules 3a to 3d, and a total of eight power transistors are included in the power unit 10. A plurality of power transistors are main components of power conversion, that is, main components of the above-described booster circuit and inverter circuit. A control board not shown in FIG. 1 controls on / off of each power transistor.

  Hereinafter, in order to simplify the description, when any one of the plurality of semiconductor modules 3a to 3d is shown without distinction, it is referred to as a semiconductor module 3. Similarly, when any one of the plurality of coolers 2a-2e is shown without distinction, it is denoted as cooler 2. Although the shapes of the coolers 2d and 2e located at the end in the stacking direction (X direction) are different from those of the other coolers 2a to 2c, the coolers 2a to 2e are collectively referred to as the cooler 2. Differences between the coolers 2d and 2e and the other coolers 2a to 2c will be described later.

  The coordinate system in the figure will be described. The X direction corresponds to the stacking direction of the plurality of coolers 2 and the plurality of semiconductor modules 3. The cooler 2 is long when viewed from the stacking direction (X direction), and the Y direction corresponds to the longitudinal direction of the cooler. For convenience of explanation, the Z direction is the vertical direction.

  The power unit 10 is disposed between the side wall 53b of the housing 53 and the support column 53a. One end of the power unit 10 in the stacking direction is in contact with the side wall 53b, and a leaf spring 54 is inserted between the other end and the column 53a. The leaf spring 54 applies pressure in the stacking direction (X direction in the figure) to the power unit 10. As will be described in detail later, the main body of the cooler 2 has an opening on the side surface facing the semiconductor module 3, and the opening is sealed by a metal plate. Sealing between the opening and the metal plate is ensured by the pressure of the leaf spring 54.

  FIG. 2 is a perspective view of the power unit 10. The semiconductor module 3 includes three power terminals 59a, 59b, and 59c on the upper surface. Inside the semiconductor module 3, two power transistors are connected in series, and the three power terminals 59a, 59b, 59c are respectively a high potential side terminal, a middle point terminal, and a low potential of the power transistors connected in series. Corresponds to the side terminal. Although not shown in the drawing, a gate terminal connected to the gate of the power transistor is provided on the lower surface of the semiconductor module 3. In other words, the semiconductor module 3 has a terminal group (power terminals 59a, 59b, 59c, and a gate terminal) extending in the Y direction.

  The cooler 2d located at one end in the stacking direction (X direction) is provided with a supply pipe 51 that supplies a refrigerant to each cooler 2 and a discharge pipe 52 that discharges the refrigerant that has passed through each cooler 2. . As shown in FIG. 1, the supply pipe 51 and the discharge pipe 52 extend out of the housing 53, and a refrigerant circulator (not shown) is connected to these pipes. The refrigerant used by the power unit 10 is a liquid, typically water or antifreeze. The structure of the cooler 2 and the refrigerant flow will be described later.

  The semiconductor module 3 is a card type, and a pair of coolers 2 are sandwiched between the semiconductor modules 3. In other words, the card-type semiconductor module 3 is sandwiched between a pair of adjacent coolers 2. Although not shown, all the semiconductor modules 3 are provided with power terminals 59a-59c.

  FIG. 3 shows a partially exploded perspective view of the power unit 10. FIG. 3 shows an exploded view of a pair of adjacent coolers 2a and 2b in the power unit 10, and a semiconductor module 3b sandwiched between them. In addition, although illustration is abbreviate | omitted, the semiconductor module 3c and the cooler 2c are arrange | positioned behind the cooler 2b (negative direction of an X-axis). The structural relationship between the adjacent coolers 2b and 2c and the semiconductor module 3c sandwiched between them is the same as the structural relationship between the coolers 2a and 2b and the semiconductor module 3b. Although not shown, a semiconductor module 3a and a cooler 2d are disposed in front of the cooler 2a (in the positive direction of the X axis). The structural relationship between the adjacent coolers 2d and 2a and the semiconductor module 3a sandwiched between them is the same as the structural relationship between the coolers 2a and 2b and the semiconductor module 3b. The cooler 2d located at one end of the power unit 10 is different from the other coolers in the structure opposite to the semiconductor module 3a, but the structure facing the semiconductor module 3a is the cooler 2a, 2b. The same. Similarly, the cooler 2e located at the other end of the power unit 10 is different from the other coolers in the structure on the side opposite to the semiconductor module 3d, but the structure on the side facing the semiconductor module 3d is the cooler 2a, Same as 2b. On the opposite side of the cooler 2d from the semiconductor module 3a, no opening is provided, and a supply pipe 51 and a discharge pipe 52 are connected. No opening is provided on the opposite side of the cooler 2e from the semiconductor module 3d.

  Below, the structure by the side of the semiconductor module 3b of the coolers 2a and 2b is demonstrated. It should be noted that the structure on the semiconductor module 3a side of the cooler 2a and the structure on the semiconductor module 3c side of the cooler 2b are the same.

  The cooler 2 b includes a main body 20, a metal plate 252, and a gasket 241. The main body 20 is made by injection molding of resin, and a flow path 201 through which a coolant passes is provided. An opening 211 is provided on a side surface 231 of the main body 20 facing the semiconductor module 3b. The opening 211 communicates with the internal flow path 201.

  The metal plate 252 has one surface facing the main body 20, the other surface facing the semiconductor module 3b, and being fixed to the semiconductor module 3b. A number of pin fins 26 are provided on a surface of the metal plate 252 facing the main body 20 (hereinafter, sometimes referred to as “surface on the main body 20 side”). On the other hand, the surface facing the semiconductor module 3b (hereinafter, sometimes referred to as “surface on the semiconductor module 3b side”) is fixed to the semiconductor module 3b with the insulating plate 19 interposed therebetween. As shown in FIG. 4, in this embodiment, the surface of the semiconductor module 3b on the metal plate 252 side is electrically conductive with two power transistors (see symbols 58a and 58b in FIGS. 5 and 6). The heat sink 57b is exposed. The insulating plate 19 insulates the heat radiating plate 57b from the metal plate 252. As shown in FIG. 4, the surface area of the insulating plate 19 sandwiched between the semiconductor module 3 b and the surface of the metal plate 252 on the semiconductor module 3 b side is smaller than the surface area of the metal plate 252. Specifically, the length of the insulating plate 19 in the Z direction is substantially the same as the length of the metal plate 252 in the Z direction, but the length of the insulating plate 19 in the Y direction is shorter than the length of the metal plate 252 in the Y direction. . Of the surface on the semiconductor module 3 b side of the metal plate 252, ridges 252 a extending along the edge of the insulating plate 19 are formed on both sides of the insulating plate 19 in the Y direction. The ridge 252a protrudes toward the semiconductor module 3b. Thereby, the recessed part 262 of the shape which can accommodate the insulating board 19 is formed between a pair of protruding item | line 252a.

  Before the metal plate 252 is fixed to the semiconductor module 3b, the insulating plate 19 is accommodated between the pair of protrusions 252a (that is, in the recess 262). In FIG. 4, the insulating plate 19 is drawn at a position away from the metal plate 252, and the insulating plate 19 accommodated between the pair of ridges 252a is drawn with phantom lines. In a state where the insulating plate 19 is accommodated between the pair of ridges 252a, the surface of the insulating plate 19 (that is, the surface facing the semiconductor module 3b) and the top surface of the pair of ridges 252a (that is, the semiconductor) The surface facing the module 3b is substantially flush with the module 3b. As described above, in this embodiment, the insulating plate 19 may have a size that fits between the pair of ridges 252a (that is, in the concave portion 262). Therefore, the insulating plate 19 having a smaller surface area than the metal plate 252 is used. can do.

  The metal plate 252 is fixed to the semiconductor module 3b in a state where the insulating plate 19 is accommodated between the pair of ridges 252a of the metal plate 252. At this time, both the surface of the insulating plate 19 and the top surface of the ridge 252a are in contact with the surface of the semiconductor module 3b. At this time, the heat radiating plate 57 b exposed on the surface of the semiconductor module 3 b comes into contact with the surface of the insulating plate 19. Thereby, the heat sink 57b and the metal plate 252 are electrically insulated. Further, when the metal plate 252 and the semiconductor module 3b are fixed, the buffer material 272 is sandwiched between the top surface of the ridge 252a and the semiconductor module 3b. That is, the top surface of the ridge 252a is brought into contact with the semiconductor module 3b via the buffer material 272. The buffer material 272 is, for example, a resin-made sheet material having elasticity.

  As shown in FIG. 3, after the surface of the metal plate 252 on the semiconductor module 3 b side is fixed to the semiconductor module 3 b, the opposite surface of the metal plate 252 (that is, the surface on the main body 20 side) is interposed via the gasket 241. Attached to the opening 211. The gasket 241 has a ring shape and is disposed on the side surface 231 of the main body 20 so as to surround the opening 211. The opening 211 is closed with a metal plate 252 through a gasket 241. In other words, one surface of the metal plate 252 (that is, the surface facing the opening 211) is attached to the opening 211 with the gasket 241 interposed therebetween. In other words, one surface of the metal plate 252 closes the opening 211 with the gasket 241 interposed therebetween, and the other surface faces the semiconductor module 3b.

  Before describing the structure of the cooler 2b opposite to the semiconductor module 3b, the structural relationship between the cooler 2a and the semiconductor module 3b will be described. Similarly to the cooler 2b, the cooler 2a also includes a main body 20, a metal plate 251, and a gasket 241. The main body of the cooler 2a also includes a flow path 201 therein, and an opening 212 is provided on a side surface 232 facing the semiconductor module 3b. The opening 212 communicates with the flow path 201. The opening 212 is sealed with a metal plate 251 with the gasket 242 interposed therebetween. The metal plate 251 has the same configuration as the metal plate 252. That is, one surface of the metal plate 251 closes the opening 212 with the gasket 242 interposed therebetween, and the other surface faces the semiconductor module 3b with the insulating plate 19 interposed therebetween.

  As shown in FIG. 4, the surface of the metal plate 251 on the semiconductor module 3 b side is fixed to the semiconductor module 3 b with the insulating plate 19 interposed therebetween. Note that conductive heat radiation plates 57a and 57c that are electrically connected to the power transistor (see reference numerals 58a and 58b in FIGS. 5 and 6) are also exposed on the surface of the semiconductor module 3b on the metal plate 251 side. The insulating plate 19 electrically insulates the heat radiating plates 57 a and 57 c from the metal plate 251. As shown in FIG. 4, the surface area of the insulating plate 19 sandwiched between the semiconductor module 3 b and the surface of the metal plate 251 on the semiconductor module 3 b side is also smaller than the surface area of the metal plate 251. That is, the length of the insulating plate 19 in the Z direction is substantially the same as the length of the metal plate 252 in the Z direction, but the length of the insulating plate 19 in the Y direction is shorter than the length of the metal plate 252 in the Y direction. Of the surface of the metal plate 251 on the semiconductor module 3b side, on both sides of the insulating plate 19 in the Y direction, ridges 251a extending along the edges of the insulating plate 19 are formed. Thereby, the recessed part 261 of the shape which can accommodate the insulating board 19 is formed between a pair of protruding item | line 251a.

  The surface of the metal plate 251 facing the semiconductor module 3b is fixed to the semiconductor module 3b after the insulating plate 19 is accommodated between the pair of protrusions 251a (that is, in the recess 261). At this time, both the surface of the insulating plate 19 and the top surface of the ridge 251a are in contact with the surface of the semiconductor module 3b. At this time, the heat radiating plates 57 a and 57 c exposed on the surface of the semiconductor module 3 b come into contact with the surface of the insulating plate 19. Thereby, the heat sinks 57a and 57c and the metal plate 251 are electrically insulated. Further, when the metal plate 251 and the semiconductor module 3b are fixed, the buffer material 271 is sandwiched between the top surface of the ridge 251a and the semiconductor module 3b. That is, the top surface of the ridge 251a is brought into contact with the semiconductor module 3b through the buffer material 271.

  The structure of the cooler 2b opposite to the semiconductor module 3b is the same as the structure of the cooler 2a on the semiconductor module 3b side. The structure of the cooler 2a opposite to the semiconductor module 3b is the same as the structure of the cooler 2b on the semiconductor module 3b side. That is, the opening 212 of the cooler 2b is also sealed with another metal plate with a gasket interposed therebetween. The opening 211 of the cooler 2a is also sealed with another metal plate with a gasket interposed therebetween. The coolers 2a and 2b are provided with openings 211 and 212 on both sides in the stacking direction, and these openings are sealed with a metal plate with a gasket interposed therebetween.

  The metal plates 251 and 252 are not fixed to the main body 20 with screws or the like. As described with reference to FIG. 1, the leaf spring 54 pressurizes the power unit 10 in the stacking direction, and the sealing between the opening 211 (212) and the metal plate 252 (251) is applied by the pressure of the leaf spring 54. Stop (watertightness) is secured. This structure is the same for any cooler. However, openings are not provided on both end surfaces of the power unit 10 in the stacking direction (one side surface of the cooler 2e and one side surface of the cooler 2d).

  On both sides in the Y direction of the main body 20 of the cooler 2b, cylindrical portions 22 protruding in the stacking direction (X direction) are formed. The cylindrical part 22 is connected to the cylindrical part 22 of the adjacent cooler 2a with the ring-shaped gasket 25 interposed therebetween. That is, the adjacent coolers are connected by the cylindrical portion 22. A through hole 221 a (221 b) that penetrates the main body 20 in the stacking direction (X direction) is provided inside the cylindrical portion 22, and the through hole 221 a (221 b) is connected to the flow path 201 inside the main body 20. Communicate. A cooler 2c is disposed behind the cooler 2b, and the connection structure between the cooler 2b and the cooler 2c is the same as the connection structure between the cooler 2a and the cooler 2b. In the power unit 10, adjacent coolers 2 communicate with each other through two through holes 221a and 221b. And the refrigerant | coolant supplied from the supply pipe | tube 51 (refer FIG. 1, FIG. 2) is distributed to each cooler 2 through one through-hole 221a, and flows through the flow path 201 to a Y direction. As described above, the main body 20 of the cooler 2b is long in the Y direction, and the refrigerant flows through the inside of the main body 20 in the long direction.

  The refrigerant absorbs the heat of the adjacent semiconductor module 3 through the metal plates 251 and 252 while passing through the flow path 201. The refrigerant that has absorbed the heat of the semiconductor module 3 is discharged from the discharge pipe 52 (see FIGS. 1 and 2) through the other through-hole 221b. As described above, a refrigerant circulator (not shown) is connected to the power unit 10, and the refrigerant discharged from the discharge pipe 52 is cooled by a radiator or the like and sent to the power unit 10 again.

  The metal plate 251 (252) faces the flow path 201 through the opening 212 (211). In addition, a large number of pin fins 26 provided on the surface of the metal plate 251 on the main body 20 side also protrude into the flow path 201 through the openings 212 (211). Therefore, the metal plate 251 (252) and the pin fin 26 are in direct contact with the refrigerant passing through the flow path 201. Therefore, the heat of the semiconductor module 3b is efficiently absorbed by the refrigerant passing through the flow path 201 via the metal plate 251 (252) and the pin fins 26.

  The other semiconductor modules 3a, 3c, and 3d are also card type like the semiconductor module 3b, and are sandwiched between the pair of coolers 2 from both sides. The semiconductor modules 3a, 3c, and 3d are also effectively cooled by the coolers 2 on both sides. On the upper part of the main body 20 of the cooler 2, a groove 204 (thickening groove) for lightening is provided.

  The positional relationship between the semiconductor module 3b, the metal plate 251, and the gasket 242 sandwiched between them will be described. FIG. 5 is a schematic diagram showing a positional relationship among the semiconductor module 3b, the metal plate 251, and the gasket 242 when viewed from the stacking direction (X direction). In FIG. 5, the metal plate 251 and the insulating plate 19 are indicated by broken lines, and the cooler 2a is indicated by an imaginary line. Moreover, the opening 212 provided in the main body of the cooler 2a is also indicated by a virtual line. Further, for easy understanding, a region excluding a region overlapping with the opening 212 of the cooler 2 among the region occupied by the semiconductor module 3b when viewed from the stacking direction is indicated by hatching. In other words, the hatched area is an area where the semiconductor module 3b faces the side surface excluding the opening 212 of the main body 20 of the cooler 2a.

  As described above, reference numerals 57a and 57c in FIG. 5 are heat radiation plates exposed on the surface of the semiconductor module 3b. The heat sink 57a is continuous with the power terminal 59a inside the semiconductor module 3b. The heat sink 57a is connected to the drain electrode of the power transistor 58a inside the semiconductor module 3b. The heat sink 57c is continuous with the power terminal 59c inside the semiconductor module 3b. The heat sink 57c is connected to the source electrode of the power transistor 58b inside the semiconductor module 3b. As described above, the heat radiating plates 57 a and 57 c are in contact with the insulating plate 19 and are electrically insulated from the metal plate 251 by the insulating plate 19. In addition, the heat sinks 57b and 57d are exposed on the back surface of the semiconductor module 3b (see FIGS. 4, 6, and 7). The heat sink 57b is continuous with the power terminal 59b inside the semiconductor module 3b. The heat sink 57b is connected to the source electrode of the power transistor 58a and the drain electrode of the power transistor 58b through the conductive spacer 62 (see FIGS. 6 and 7) inside the semiconductor module 3b. . That is, the heat sink 57b connects the two power transistors 58a and 58b in series. As described above, the heat radiating plate 57 b is in contact with the insulating plate 19 and is insulated from the metal plate 252 by the insulating plate 19. FIG. 5 also shows a gate terminal 61 extending from the lower surface of the semiconductor module 3b.

  Since the heat sinks 57a and 57c in FIG. 5 are connected to the electrodes of the internal power transistors 58a and 58b, the heatsinks 57a and 58b conduct heat well. As shown in FIG. 5, the opening 212 of the cooler 2 is provided so as to overlap the entire region of the heat sinks 57 a and 57 c when viewed from the stacking direction. That is, the metal plate 251 is opposed to the heat radiating plates 57a and 57c via the insulating plate 19 on one surface, and the other surface is in direct contact with the refrigerant. A number of pin fins 26 are provided on the other surface of the metal plate 251 as described above. The heat of the power transistors 58a and 58b is well transferred to the refrigerant through the heat radiating plates 57a and 57c and the metal plate 251. The same applies to the surface of the semiconductor module 3b opposite to the surface shown in FIG.

  The gasket 242 is disposed on the side surface of the main body 20 around the opening 212 so as to surround the opening 212 when viewed from the stacking direction (X direction). In order to cool the semiconductor module 3b efficiently, the opening 212 is provided large. As shown in FIG. 5, when viewed from the stacking direction (X direction), the ring-shaped gasket 242 surrounding the opening 212 overlaps the semiconductor module 3b on the entire circumference. At the same time, a part of the gasket 242 overlaps the ridge 251a. Further, the other part overlaps the insulating plate 19. That is, it can be said that the gasket 242 overlaps with either the protrusion 251a of the metal plate 251 or the insulating plate 19 on the entire circumference.

  As described above, the metal plate 251 is pressed against the gasket 242 by the plate spring 54 (see FIG. 1), and the metal plate 251 receives a reaction force from the gasket 242. As described above, in this embodiment, both the insulating plate 19 and the top of the ridge 251a are in contact with the semiconductor module 3b. That is, as well shown in FIG. 5, the metal plate 251 can be said to be supported by the semiconductor module 3 b on the opposite side (that is, the semiconductor module 3 b side) over the entire circumference of the gasket 242. Therefore, even if the metal plate 251 receives a reaction force from the gasket 242, it does not bend. As described above, in this embodiment, even when the insulating plate 19 having a surface area smaller than that of the metal plate 251 is used, the portion of the metal plate 251 that receives the reaction force of the gasket 242 is all supported by the semiconductor module 3b. The Therefore, the metal plate 251 does not bend due to the reaction force of the gasket 242, and the sealing performance between the opening 212 and the metal plate 252 can be improved.

  FIG. 6 is a view in which a stacked body of a pair of adjacent coolers 2a and 2b and a semiconductor module 3b sandwiched between them is cut along a cross-section corresponding to the VI-VI line in FIG. However, the lower half of the laminate is not shown in FIG. In the cross section of FIG. 6, the gasket 241 (242), the insulating plate 19, and the semiconductor module 3b overlap each other when viewed from the stacking direction (X direction). As described above, the power unit 10 is pressurized in the stacking direction (X direction) by the leaf spring 54 (see FIG. 1), and the opening 212 (211) and the metal plate 251 (252) are applied by the applied pressure. Sealing is ensured. The metal plate 251 (252) receives a reaction force (reaction force against the pressure force of the leaf spring 54) from the gasket 242 (241). On the other hand, the insulating plate 19 is in contact with the heat radiating plates 57a, 57b, 57c of the semiconductor module 3b. That is, the surface opposite to the gasket 242 (241) of the metal plate 251 (252) (that is, the surface on the semiconductor module 3b side) is supported by the semiconductor module 3b via the insulating plate 19. Therefore, even if the metal plate 251 (252) receives a reaction force from the gasket 242 (241), it does not bend.

  As described above, the semiconductor module 3 b is a device in which the power transistors 58 a and 58 b are sealed with resin, and the body is made of the resin mold 31. The same applies to the other semiconductor modules 3a, 3c, 3d. In FIG. 5, the code | symbol 26 has shown the pin fin provided in the metal plate 251 (252). Reference numeral 204 indicates a groove (thickening groove) for reducing the weight of the main body 20 as described above. Reference numeral 205 denotes a groove for accommodating the gasket 241 (242).

  FIG. 7 is a view in which a stacked body of a pair of adjacent coolers 2a and 2b and a semiconductor module 3b sandwiched between them is cut along a cross-section corresponding to the line VII-VII in FIG. However, a part of the Y direction is omitted. Also in the cross section of FIG. 7, the gasket 242 (241) and the semiconductor module 3b overlap each other when viewed from the stacking direction (X direction). Furthermore, the gasket 242 (241) and the convex strip 251a (252a) also overlap. The part shown in FIG. 7 and the part opposite to the Y direction have the same structure. Therefore, as shown in FIGS. 4 to 7, when viewed from the stacking direction, the gaskets 241 and 242 overlap with the semiconductor module 3 b over the entire circumference of the ring-shaped gaskets 241 and 242. At the same time, a part of the gasket 242 overlaps the ridge 251a. Further, the other part overlaps the insulating plate 19.

  A groove 205 is provided around the openings 212 and 211 of the main body 20, and gaskets 241 and 242 are disposed in the groove 205. The groove 205 is not shown in FIGS. Moreover, the groove | channel 207 is provided in the end surface of the cylinder part 22 of the coolers 2a and 2b so that the through-hole 221a (221b) may be enclosed, and the gasket 25 is arrange | positioned in the groove | channel 207. In FIG. 1 to FIG. 5, the illustration of the groove 207 is omitted.

(Operational effect of this embodiment)
The structure of the inverter 100 according to the present embodiment has been described above. As described above, in the present embodiment, the insulating plate 19 only needs to be large enough to fit between the pair of ridges 251a (252a) (that is, in the recesses 261 and 262), so that the insulating plate 19 is larger than the metal plate 251 (252). An insulating plate 19 having a small surface area can be used. Furthermore, in this embodiment, when viewed from the stacking direction (X direction), the protrusion 251a (252a) overlaps with a part of the gasket 242 (241), but the top surface of each protrusion 251a (252a) is a semiconductor module. It is in contact with 3b. Therefore, even when the insulating plate 19 having a smaller surface area than that of the metal plate 251 (252) is used, the portion of the metal plate 251 (252) that receives the reaction force of the gasket 242 (241) is entirely the semiconductor module 3b. Can be supported. Therefore, the metal plate 251 (252) does not bend due to the reaction force of the gasket 242 (241), and the sealing performance between the opening 212 (211) and the metal plate 251 (252) can be improved.

(Correspondence)
The correspondence between this embodiment and the claims will be described. The leaf spring 54 of this embodiment is an example of an “elastic member”. The surface on the main body 20 side of the metal plate 251 (252) is an example of “one surface”, and the surface on the semiconductor module 3b side of the metal plate 251 (252) is an example of “the other surface”. .

(Second embodiment)
A description will be given centering on differences from the first embodiment. As shown in FIG. 8, in this embodiment, the length of the insulating plate 19 in the Y direction is shorter than the length of the metal plate 252 in the Y direction, and the length of the insulating plate 19 in the Z direction is also the Z direction of the metal plate 252. This is different from the first embodiment in that it is shorter than the first length. Therefore, in this embodiment, the protrusions 252a are formed on both sides of the insulating plate 19 in the Y direction on the surface of the metal plate 252 on the semiconductor module 3b side, and also on both sides of the insulating plate 19 in the Z direction. A protruding line 252b is formed. That is, the recessed part 262 of the shape which can accommodate said insulating board 19 is formed between a pair of protruding item | line 252a and between a pair of protruding item | line 252b. Also in this embodiment, in a state where the insulating plate 19 is accommodated between the ridge 252a and the ridge 252b (that is, in the recess 262), the surface of the insulating plate 19, the top of the ridge 252a, and the head of the ridge 252b. The top is formed substantially flush with the top.

  The metal plate 252 is fixed to the semiconductor module 3b in a state where the insulating plate 19 is accommodated between the protrusions 252a and 252b (that is, in the recess 262) of the metal plate 252. At this time, the surface of the insulating plate 19, the top surface of the ridge 252a, and the top surface of the ridge 252b are all in contact with the surface of the semiconductor module 3b. The insulating plate 19 abuts on the heat radiating plate 57b and electrically insulates the heat radiating plate 57b and the metal plate 252 from each other. In addition, a buffer material 272 is sandwiched between the top surface of the ridge 252a and the semiconductor module 3b during fixing. That is, the top surface of the ridge 252a is in contact with the semiconductor module 3b with the buffer material 272 interposed therebetween. Although not shown, a cushioning material may be sandwiched between the top surface of the ridge 252b and the semiconductor module 3b as well.

  The metal plate 251 fixed to the opposite side of the semiconductor module 3b also has the same configuration as the metal plate 252. That is, the protrusions 251a are formed on both sides of the insulating plate 19 in the Y direction on the surface of the metal plate 251 on the semiconductor module 3b side, and the protrusions 251b are also formed on both sides of the insulating plate 19 in the Z direction. ing. That is, the recessed part 261 of the shape which can accommodate the insulating board 19 is formed between a pair of protruding item | line 251a and between a pair of protruding item | line 251b. In FIG. 8, the opening edge of the recess 261 is indicated by a broken line for easy understanding. In a state where the insulating plate 19 is accommodated between the ridge 251a and the ridge 251b (that is, in the recess 261), the surface of the insulating plate 19, the top of the ridge 251a, and the top of the ridge 251b are approximately It is formed flush.

  The metal plate 251 is fixed to the semiconductor module 3b in a state where the insulating plate 19 is accommodated between the protrusions 251a and 251b of the metal plate 251. At this time, the surface of the insulating plate 19, the top surface of the ridge 251a, and the top surface of the ridge 251b are all in contact with the surface of the semiconductor module 3b. The insulating plate 19 is in contact with the heat radiating plates 57 a and 57 c and electrically insulates the heat radiating plates 57 a and 57 c from the metal plate 251. In addition, a buffer material 271 is sandwiched between the top surface of the ridge 251a and the semiconductor module 3b during fixing. That is, the top surface of the ridge 251a is in contact with the semiconductor module 3b with the buffer material 271 interposed therebetween. Although not shown, a cushioning material may also be sandwiched between the top surface of the ridge 251b and the semiconductor module 3b.

  Even when the structure of this embodiment is employed, the entire circumference of the gasket 242 (241) overlaps the semiconductor module 3b as viewed from the stacking direction. At the same time, part of the gasket 242 (241) overlaps with the ridge 251a (252a), and the other part overlaps with the ridge 251b (252b). That is, it can be said that the gasket 242 (241) overlaps with the ridges 251a (252a) or the ridges 251b (252b) on the entire circumference.

(Operational effect of this embodiment)
Also in the present embodiment, the insulating plate 19 only needs to be large enough to fit between the ridges 251a (252a) and between the ridges 251b (252b) (that is, in the recesses 261 and 262). The insulating plate 19 having a smaller surface area than (252) can be used. Furthermore, in this embodiment, when viewed from the stacking direction (X direction), the ridges 251a (252a) and the ridges 251b (252b) both overlap the gasket 242 (241), but the ridges 251a (252a) ), The top surface of the ridge 251b (252b) is in contact with the semiconductor module 3b. Therefore, even when the insulating plate 19 having a smaller surface area than that of the metal plate 251 (252) is used, the portion of the metal plate 251 (252) that receives the reaction force of the gasket 242 (241) is entirely the semiconductor module 3b. Supported. Therefore, the metal plate 251 (252) does not bend due to the reaction force of the gasket 242 (241), and the sealing performance between the opening 212 (211) and the metal plate 251 (252) can be improved.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. For example, the following modifications may be adopted.

(Modification 1) The power conversion device of each of the above embodiments is the inverter 100 that converts the DC power of the battery into AC power. The technology disclosed in this specification is also preferably applied to a power conversion device other than an inverter. In addition, the technology disclosed in this specification includes not only a power unit in which one semiconductor module is sandwiched between a pair of coolers, but also includes a plurality of coolers and a plurality of semiconductor modules. The present invention can also be applied to a power conversion device including a power unit in which a semiconductor module is inserted.

(Modification 2) In each of the above-described embodiments, as shown in FIGS. 4 and 8, the protrusions 251a (252a) of the metal plate 251 (252) are connected to the semiconductor module 3b via the buffer material 271 (272). Abut. However, the protrusion 251a (252a) may be in direct contact with the semiconductor module 3b without using the buffer material 271 (272).

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2, 2a-2d: coolers 3, 3a-3d, 103b: semiconductor module 10: power unit 19: insulating plate 20: main body 22: cylinder part 25: gasket 26: pin fin 51: supply pipe 52: discharge pipe 53: housing 54 : Plate spring 55: Reactor 56: Capacitor 58: Power transistors 59 a, 59 b, 59 c: Power terminal 100: Inverter 201: Channel 211, 212: Opening 241, 242: Gasket 251, 252: Metal plate 251 a, 252 a: Projection 251b, 252b: ridges 261, 262: recesses 271, 272: cushioning material

Claims (1)

A stacked power unit comprising a card-type semiconductor module containing a semiconductor element and a pair of coolers sandwiching the semiconductor module;
An elastic member that pressurizes the power unit in the stacking direction of the semiconductor module and the cooler;
With
A conductive heat sink that is electrically connected to the semiconductor element is exposed on a surface of the semiconductor module that faces the cooler,
Each of the pair of coolers
A flow path through which a coolant flows is provided inside, and a main body provided with an opening communicating with the flow path on a side surface facing the semiconductor module;
A gasket disposed on the side surface so as to surround the opening when viewed from the stacking direction;
A metal plate whose one surface closes the opening across the gasket and whose other surface faces the semiconductor module;
With
The sealing between the opening and the metal plate is ensured by the pressure of the elastic member,
Between the metal plate and the semiconductor module, an insulating plate that electrically insulates the heat radiating plate and the metal plate is sandwiched,
Convex ridges extending along edges of the insulating plate are provided on both sides of the insulating plate on the other surface of the metal plate,
When viewed from the stacking direction, the gasket overlaps with the semiconductor module, and the ridge overlaps with a part of the gasket,
The top surface of the ridge is in contact with the semiconductor module;
The power converter characterized by the above-mentioned.

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