JP6672659B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device including a power semiconductor module for power conversion, a control circuit board on which circuit components for driving the power semiconductor module are mounted, and a housing for housing these components.

As this type of power converter, a power converter described in Patent Literature 1 is known.
In this power conversion device, a power module, a capacitor module, a metal holding plate, and a control circuit board are housed in a metal housing. Here, the holding plate is fixed inside the housing by a screw member, and the capacitor module and the control circuit board are fixed to the holding plate.

JP 2007-282370A

In the power conversion device of Patent Document 1, since the circuit components mounted on the control circuit board generate heat, it is desired that the heat generated in the control circuit board be transmitted to the housing from the holding plate and radiated to the outside air. . However, the contact thermal resistance of the joint between the holding plate fixed to the screw member and the housing is large, and the heat generated in the control circuit board is not easily transmitted from the holding plate to the housing.
Therefore, the power conversion device of Patent Document 1 cannot efficiently radiate the heat generated in the control circuit board.
SUMMARY OF THE INVENTION The present invention has been made in view of the unsolved problems of the conventional example, and has as its object to provide a power conversion device capable of efficiently radiating heat of circuit components mounted on a control circuit board. The purpose is.

In order to achieve the above object, a power conversion device according to one embodiment of the present invention includes a power semiconductor module for power conversion, a control circuit board on which circuit components for driving the power semiconductor module are mounted, a power semiconductor module, and a control device. A metal housing provided with a storage space for storing the circuit board, and a cooler in which a cooling medium circulates, and an opening communicating with the storage space is formed in the housing . the opening communicating with the outside and the storage space of the housing is formed, in Kikatamitai, the position of the receiving space opposite the opening, provided with a plurality of retaining projections on the side for fixing the control circuit board holding portion is formed integrally, by detachably securing the cooler bonding the power semiconductor module from outside the housing to the periphery of the opening, the holding portion is disposed along the power semiconductor module, control Road board is fixed to the top of the plurality of retaining projections in a state in which a gap is provided between the opposing surfaces of the holding portion.

  According to the power conversion device of the present invention, since the holding portion that supports the control circuit board inside the housing is formed integrally with the housing, the holding portion and the housing that do not have a joint are provided between the holding portion and the housing. No contact thermal resistance is generated, and heat generated in the circuit components of the control circuit board is easily transmitted from the holding unit to the housing. Therefore, the heat of the circuit components mounted on the control circuit board can be efficiently radiated.

It is a perspective view showing the power converter of a 1st embodiment concerning the present invention. FIG. 2 is a cross-sectional view of the power converter according to the first embodiment along a plane A in FIG. 1. FIG. 2 is a cross-sectional view of the power converter according to the first embodiment along a plane B orthogonal to a plane A in FIG. 1. FIG. 2 is an exploded perspective view illustrating components of the power converter according to the first embodiment. It is a figure showing the structure of the circumference of the opening of the case where the cooler is detachably fixed in the power converter of a 1st embodiment. It is a figure showing the structure of the case which holds the control circuit board in the power converter of a 1st embodiment. It is a perspective view showing the structure of the cooler used in the power converter of a 1st embodiment. FIG. 2 is a perspective view illustrating a power semiconductor module used in the power converter according to the first embodiment. It is a figure showing the state where a cooler was fixed to a part of case in the power converter of a 1st embodiment, and a holding part integrated with a case is shown by a two-dot chain line. 2 is an equivalent circuit of a power semiconductor module used in the power converter according to the first embodiment. It is a figure showing the structure of the case which holds the control circuit board in the power converter of a 2nd embodiment concerning the present invention. It is a figure showing the structure of the case which holds the control circuit board in the power converter of a 3rd embodiment concerning the present invention.

Next, first to third embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the plane dimension, the ratio of the thickness of each layer, and the like are different from actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. In addition, it goes without saying that parts having different dimensional relationships and ratios are included between the drawings.
The first to third embodiments described below exemplify an apparatus and a method for embodying the technical idea of the present invention. The shape, structure, arrangement, etc. are not specified as follows. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

[Power Converter of First Embodiment]
Hereinafter, a power converter according to a first embodiment of the present invention will be described with reference to the drawings as appropriate.
As shown in FIG. 1, a power converter 1 according to a first embodiment of the present invention includes a housing 2 and a cooler 3 detachably fixed to a bottom surface of the housing 2.
As shown in FIGS. 2 and 3, three insulated gate bipolar transistor (IGBT) modules 10 U, 10 V, and 10 W joined to the cooler 3, and these IGBT modules 10 U, 10 V, and 10 W A control circuit board 11 on which a drive circuit or the like for driving the IC is mounted, a smoothing capacitor 12, a DC input connector 13, and an AC output connector 14 are housed.

[Housing]
The housing 2 includes a case 4, a cover 5, and a gasket 6.
Case 4 is formed of aluminum or an aluminum alloy. Note that the case 4 may be formed of copper or a copper alloy.
As shown in FIG. 4, the case 4 includes a bottom 4a and a side wall 4b rising from the entire circumference of the bottom 4a. A polygonal upper opening 4c is opened at an upper end of the side wall 4b, and a pair of opposing sides is provided. The holding portion 32 is formed integrally with the case 4 so as to extend between the side wall portions 4b.
The case 4 is a member that is elongated in the left-right direction in FIG. 4. When the upper opening 4 c is closed by the cover 5 via the gasket 6, a storage space S <b> 1 having a rectangular shape in plan view is formed at the center in the elongated direction. Storage spaces S2 and S3 smaller than the storage space S1 are formed at both ends in the longitudinal direction.
A mounting flange portion 7 is formed on the entire periphery of the upper end of the side wall portion 4b of the case 4 so as to protrude outward, and a screw hole 7a is formed at a predetermined position of the mounting flange portion 7.

A rectangular IGBT module opening 8 that opens in the storage space S <b> 1 is formed in the bottom 4 a of the case 4. The long direction of the IGBT module opening 8 is formed to extend in the short direction of the bottom 4a (the oblique vertical direction in FIG. 4), and both ends of the IGBT module opening 8 in the long direction are side walls. It opens to the lower end of the part 4b.
In addition, a plurality of first female threads 25 are formed at predetermined intervals on the bottom 4a along one long side edge of the IGBT module opening 8, and the other length of the other IGBT module opening 8 is formed. A plurality of second female screw portions 26 and third female screw portions 27 are formed at a predetermined interval on the bottom 4a along the side edge.

As shown in FIG. 5A, the first male screw portion 25 is a cap-nut-shaped member that protrudes inside the case 4 and has a female screw 25a that opens downward.
As shown in FIG. 5B, the second male screw portion 26 is a cap nut-shaped member that protrudes inside the case 4 and has a female screw 26a that opens downward. The third female screw portion 27 protrudes from the outer periphery of the second male screw portion 26 toward the IGBT module opening 8, and has a female screw 27 a communicating with the inside and outside of the case 4.

  As shown in FIGS. 3 and 4, the holding portion 32 is integrally formed between a pair of side wall portions 4b, 4b facing each other, and has a rectangular shape in a plan view positioned above the IGBT module opening 8. It is a member of. A plurality of holding projections 40a to 40e are formed on the surface of the holding portion 32 so as to protrude, and a plurality of lead frame insertion slits 41 communicating with the front and back directions are formed.

  FIG. 6 shows specific formation positions of the holding protrusions 40a to 40e of the holding portion 32. Four holding protrusions 40a to 40d are formed on four corner surfaces of the holding portion 32 in plan view. One holding projection 40e is located at a position where a diagonal line T1 connecting the two holding projections 40a and 40c at the diagonal positions and a diagonal line T2 connecting the two holding projections 40b and 40d at the other diagonal positions intersect. Is formed. Female threads (not shown) are formed at the tops of the five holding projections 40a to 40e.

As shown in FIG. 4, the cover 5 is a plate-shaped member made of aluminum or an aluminum alloy and formed in the same shape as the outer peripheral shape of the mounting flange 7 of the case 4. A screw insertion hole 5a is formed in the cover 5 at a position corresponding to the screw hole 7a of the mounting flange portion 7 of the case 4 of the case 4. Note that the cover 5 may also be formed using copper or a copper alloy as a material.
As shown in FIG. 4, the gasket 6 is formed in the same shape as the mounting flange 7, and has a screw insertion hole 6 a at a position corresponding to the screw hole 7 a of the mounting flange 7.

[Cooler]
The cooler 3 is a member formed using aluminum or an aluminum alloy as a material. As shown in FIG. 7, the cooler 3 includes a cooling water supply port 15a and a cooling water discharge port 15b, in which cooling water circulates, and a flat surface is formed. , A block-shaped cooler body 15 provided with a rectangular joining surface 15c, and a pair of plate-shaped fixing portions projecting outward from a pair of long sides of the joining surface 15c and provided with screw insertion holes 16a at predetermined intervals. 16. Note that the cooler 3 may be formed using copper or a copper alloy as a material.

[IGBT module]
The IGBT module 10U shown in FIG. 8 has a rectangular parallelepiped resin package 17 and an upper arm semiconductor chip, an upper arm wiring pattern section, an upper arm wiring conductor plate, a lower arm semiconductor chip, and a lower arm wiring pattern (not shown). Portion, a conductor plate for lower arm wiring, a wiring pattern portion for grounding, and the like are embedded.
On the first side face 17a of the resin package 17, a positive electrode side connection terminal 18 connected to the collector of the upper arm semiconductor chip via the upper arm wiring pattern portion, a grounding wiring pattern portion and a lower arm wiring conductor plate are provided. A negative-side connection terminal 19 connected to the emitter of the lower arm semiconductor chip via the lower side protrudes outward, and a lower arm wiring pattern portion and an upper arm are provided on the second side surface 17b on the back surface with respect to the first side surface 17a. An output terminal 20 connected to the emitter of the upper arm semiconductor chip and the collector of the lower arm semiconductor chip via the wiring conductor plate protrudes outward.

Further, on the upper surface of the resin package 17, a plurality of upper arm lead frames 21 connected to a plurality of upper arm control electrodes (gate electrodes, emitter current sense electrodes, temperature detecting electrodes, etc., which will be described later), A plurality of lower arm lead frames 22 connected to the plurality of arm control electrodes are provided to protrude upward.
The other two IGBT modules 10V and 10W also have the same configuration as the IGBT module 10U shown in FIG.

  FIG. 10 shows an equivalent circuit of three IGBT modules 10U, 10V, and 10W. A reverse conducting IGBT module QU constituting an upper arm is provided between a positive connection terminal 18 and a negative connection terminal 19; A reverse conducting IGBT module QL constituting a lower arm is connected in series, and an output terminal 20 is provided between the reverse conducting IGBT module QL and the reverse conducting IGBT module QL. Here, reference numeral 21g is a gate electrode of the reverse conducting IGBT module QU, reference numeral 21es is an emitter current sense electrode of the reverse conducting IGBT module QU, reference numeral 22g is a gate electrode of the reverse conducting IGBT module QU, and reference numeral 22es is It is an emitter current sense electrode of the reverse conducting IGBT module QL.

[Assembly of Power Conversion Device of First Embodiment]
Next, an assembling procedure of the power conversion device 1 according to the first embodiment will be described.
The three IGBT modules 10U, 10V, and 10W are sintered at the positions indicated by the two-dot chain lines in the joining surface 15c of the cooler 3 shown in FIG. 7 (positions spaced at predetermined intervals in the longitudinal direction of the joining surface 15c). It is joined by a sintered metal or solder by the processing (see FIG. 4).
As shown in FIG. 9, the three IGBT modules 10U, 10V, and 10W integrated with the cooler 3 have an opening for the IGBT module of the case 4 as shown in FIG. 8 is inserted from the bottom 4 a side, and is disposed in the storage space S <b> 1 of the case 4.

At this time, the upper arm lead frame 21 and the lower arm lead frame 22 protruding from the upper surfaces of the IGBT modules 10U, 10V, and 10W pass through the plurality of lead frame insertion slits 41 of the holding section 32, and Protrude upward.
Then, the fixing portion 16 of the cooler 3 is brought into contact with the bottom portion 4a along the pair of long side edges of the opening 8 for the IGBT module, and the first female screw portion 25 and the second female screw portion 26 of the bottom portion 4a are provided with the cooler. The screw member 30 that has passed through the screw insertion hole 16a is screwed to the first female screw portion 25 and the second female screw portion 26, with the screw insertion holes 16a of the three fixed portions 16 corresponding to each other.
Thus, the cooler 3 is detachably attached to the bottom 4a of the case 4 with the IGBT modules 10U, 10V, and 10W arranged in the storage space S1 of the case 4.

As shown in FIG. 6, the control circuit board 11 is a rectangular member slightly smaller than the holding portion 32 of the case 4, and has a circuit component 43 for driving the IGBT modules 10U, 10V, and 10W mounted thereon. ing.
The control circuit board 11 has screws at positions corresponding to the five holding projections 40a to 40e of the holding part 32, that is, at the four corner positions in plan view and the center part in plan view where two diagonals of these four corners intersect. An insertion hole (not shown) is formed.
The control circuit board 11 is placed on the holding projections 40a to 40e of the holding section 32. The screw member 44 inserted into the screw insertion hole of the holding protrusions 40a to 40e is screwed into a female screw formed on the top of the holding protrusions 40a to 40e, so that the control circuit board 11 is held by the holding portion 32. Is done.

  Here, as shown in FIG. 3, the upper arm lead frame 21 and the lower arm lead frame 22 projecting from the upper surfaces of the three IGBT modules 10U, 10V, and 10W and passing through the lead frame insertion slits 41 of the holding portion 32 are Is inserted through a through hole (not shown) having a land of the control circuit board 11, and the space between the upper arm lead frame 21, the lower arm lead frame 22 and the through hole is soldered.

As shown in FIG. 2, a smoothing capacitor 12 is disposed adjacent to the three IGBT modules 10U, 10V, and 10W in the storage space S1 of the case 4, and the three IGBT modules 10U, 10V, and 10W are connected to the positive electrode side. The terminal 18 and the negative electrode side connection terminal 19 are connected to the positive and negative electrodes of the smoothing capacitor 12.
Further, an AC output connector 14 is arranged in the storage space S2 of the case 4, and the output terminals 20 of the three IGBT modules 10U, 10V, and 10W are connected to the AC output connector 14 via busbars 33. The bus bar 33 is supported by AC output terminal blocks 29 and 31 arranged in the storage space S1 of the case 4.

Further, a DC input terminal block 28 and a DC input connector 13 are arranged in the storage space S3 of the case 4, and the DC input connector 13 and the smoothing capacitor 12 are connected via a bus bar 34. The bus bar 34 is supported above the DC input terminal block 28.
Then, as shown in FIGS. 2 and 3, the gasket 6 is placed on the mounting flange 7 of the case 4, the outer peripheral edge of the cover 5 is placed on the gasket 6, and the screw insertion hole 5 a of the cover 5 and the screw of the gasket 6 are screwed. By screwing the screw member 35 inserted into the insertion hole 6a into the screw hole 7a of the mounting flange 7, the upper opening of the case 4 is closed. As a result, the IGBT modules 10U, 10V, 10W, the control circuit board 11, the smoothing capacitor 12, the DC input connector 13, and the AC output connector 14 housed in the housing 2 are liquid-tightly sealed from the outside air. .

[Operation of Power Converter of First Embodiment]
In this state, DC power is supplied from an external converter (not shown) via the DC input connector 13, and a gate signal including, for example, a pulse width modulation signal is supplied from the control circuit board 11 to the IGBT modules 10U, 10V, and 10W. I do. That is, the three IGBT modules 10U, 10V, and 10W are turned on / off by gate signals shifted by 120 degrees from each other, so that three-phase alternating currents of the U, V, and W phases are loaded through the AC output connector 14. Is output to

In the control circuit board 11, the circuit components 43 that operate the IGBT modules 10U, 10V, and 10W are in a heating state. Here, the holding portion 32 that supports the control circuit board 11 inside the housing 2 is a portion formed integrally with the case 4 that forms the housing 2, and the holding portion 32 having no joint portion and No contact thermal resistance occurs between the cases 4.
For this reason, the heat generated in the circuit components 43 of the control circuit board 11 is easily transmitted to the case 4 from the holding portion 32 where no contact thermal resistance is generated.
Here, the power semiconductor module according to the present invention corresponds to the IGBT modules 10U, 10V, and 10W, the housing according to the present invention corresponds to the case 4 and the cover 5, and the circuit component according to the present invention corresponds to the circuit component 43. doing.

[Effects of Power Converter of First Embodiment]
Next, effects of the power conversion device 1 according to the first embodiment will be described.
The holding portion 32 supporting the control circuit board 11 inside the housing 2 is a portion formed integrally with the case 4 constituting the housing 2, and the holding portion 32 and the case 4 having no joint portion are provided. Since no contact thermal resistance is generated between them, and the heat generated in the circuit components 43 of the control circuit board 11 is easily transmitted from the holding portion 32 to the case 4, the heat of the circuit components 43 mounted on the control circuit board 11 is reduced. Heat can be efficiently dissipated.

In addition, since the assembly of the case 4 and the holding unit 32 is not required, the number of components and the number of assembling steps can be reduced, so that the manufacturing cost of the power conversion device 1 can be reduced.
Further, since the case 4 and the holding portion 32 are made of a metal having a high thermal conductivity (aluminum, an aluminum alloy, copper, or a copper alloy), heat generated in the circuit component 43 of the control circuit board 11 is It is easy to be transmitted to the case 4 and the cooling efficiency of the circuit component 43 can be increased.

Further, since the control circuit board 11 is supported on the holding projections 40 a to 40 e provided on the holding section 32, an air layer can be provided around the control circuit board 11 and housed in the housing 2. Therefore, the effect of the electromagnetic shield can be enhanced.
Further, since the four corners and the center of the control circuit board 11 are fixed via the holding projections 40a to 40e of the holding section 32, the vibration of the control circuit board 11 is suppressed even when an external force is transmitted from the housing 2. Thus, the control circuit board 11 can be prevented from being deteriorated due to vibration.
Further, since the cooler 3 joined to the case 4 is formed of a metal having a high thermal conductivity (aluminum, aluminum alloy, copper, or copper alloy), the cooler 3 is generated in the circuit component 43 of the control circuit board 11. Heat is further easily transmitted from the holding portion 32 to the case 4, and the cooling efficiency of the circuit component 43 can be further improved.

[Power Converter of Second Embodiment]
Next, a power converter according to a second embodiment of the present invention will be described with reference to FIG. Note that the same components as those of the power converter 1 of the first embodiment shown in FIGS. 1 to 10 are denoted by the same reference numerals, and description thereof is omitted.
Four holding protrusions 40a to 40d are formed on four corners of the surface of the holding portion 32 of the power conversion device according to the second embodiment, and a center portion (specifically, two holding protrusions 40a) in plan view is formed. , 40c, and a diagonal line connecting the two holding projections 40b, 40d) is formed at a position where the diagonal line intersects the diagonal line connecting the two holding projections 40b, 40d), and around the circuit component 43 mounted on the control circuit board 11. Four holding projections 40f to 40i are formed so as to be located.

The control circuit board 11 is placed on the holding protrusions 40a to 40i of the holding portion 32, and the screw members 44 inserted into the screw insertion holes of the holding protrusions 40a to 40i are provided on the tops of the holding protrusions 40a to 40e. The control circuit board 11 is held by the holding portion 32 by being screwed into the formed female screw portion.
According to the power converter of the second embodiment, the four holding projections 40f to 40i located around the circuit component 43 mounted on the control circuit board 11 and the control circuit board 11 are held by the screw member 44. Thus, the heat generated in the circuit component 43 is transmitted to the holding portion 32 from the four holding protrusions 40f to 40i located on the periphery, and the heat is generated by the five holding protrusions 40a to 40e shown in the first embodiment. The heat transfer can be efficiently performed by the holding portion 32 provided.

Therefore, in the power converter according to the second embodiment, the heat generated in the circuit components 43 of the control circuit board 11 is more easily transmitted from the holding unit 32 to the case 4, and the cooling efficiency of the circuit components 43 can be further improved. it can.
In the power converter of the second embodiment, the holding projections 40 a to 40 i of the holding section 32 are fixed at the four corners, the center, and the periphery of the circuit component 43 of the control circuit board 11, so that Even if an external force is transmitted, the vibration of the control circuit board 11 is suppressed, and the deterioration of the control circuit board 11 due to the vibration can be prevented.

[Power Converter of Third Embodiment]
Next, a power converter according to a third embodiment of the present invention will be described with reference to FIG.
Four holding projections 40a to 40d are formed on four corners of the surface of the holding unit 32 of the power conversion device according to the third embodiment, and a holding projection 40e is formed at the center in plan view. A holding projection 40j is formed at an intermediate position on a straight line connecting the holding projections 40a and 40b, a holding projection 40k is formed at an intermediate position on a straight line connecting the holding projections 40b and 40c, and the holding projections 40c and 40d are formed. The holding projection 40l is formed at a middle position on a straight line connecting the holding projections 40a and 40d, and the holding projection 40m is formed at a middle position on a straight line connecting the holding projections 40a and 40d.

The control circuit board 11 is placed on the holding protrusions 40a to 40e, 40j to 40m of the holding unit 32, and the screw members 44 inserted into the screw insertion holes of the control circuit board are held by the holding protrusions 40a to 40e, 40j. The control circuit board 11 is held by the holding section 32 by being screwed into a female screw section formed at the top of about 40 m.
According to the power converter of the third embodiment, since the holding projections 40a to 40e and 40j to 40m are dispersedly arranged in the plane area of the control circuit board 11, the heat generated in the control circuit board 11 is The heat is immediately transmitted to the holding unit 32 via the holding protrusions 40a to 40e and 40j to 40m, and the heat is more efficiently generated than the holding unit 32 including the five holding protrusions 40a to 40e shown in the first embodiment. Communication can take place.

Therefore, in the power converter of the third embodiment, the heat generated in the control circuit board 11 is efficiently transmitted from the holding unit 32 to the case 4, and the cooling efficiency of the control circuit board 11 can be improved.
Further, the power converter of the third embodiment is fixed at 40a to 40d and 40j to 40m of the control circuit board 11, so that the vibration of the control circuit board 11 is suppressed even when an external force is transmitted from the housing 2. Thus, it is possible to prevent deterioration of the control circuit board 11 due to vibration.

Reference Signs List 1 power conversion device 2 housing 3 cooler 4 case 4a bottom 4b side wall 4c top opening 5, 43 cover 5a screw insertion hole 6 gasket 6a screw insertion hole 7 mounting flange 7a screw hole 8 IGBT module opening 10U 10 V, 10 W IGBT module 11 Control circuit board 12 Smoothing capacitor 13 DC input connector 14 AC output connector 15 Cooler body 15a, 46a Cooling water supply port 15b, 46b Cooling water outlet 15c Joining surface 16 Fixed portion 16a Screw insertion hole 17 Resin Package 17a First side surface 17b Second side surface 18 Positive side connection terminal 19 Negative side connection terminal 20 Output terminal 21 Lead frame 21g for upper arm 21g Gate electrode 21es of reverse conducting IGBT module QU Emitter current sense electrode of reverse conducting IGBT module QU 22 For lower arm Over lead frame 22
22g Gate electrode 22es of reverse conducting IGBT module KU Emitter current sense electrode 25 of reverse conducting IGBT module QL First female thread 25a Female thread 26 Second female thread 26a Female thread 27 Third female thread 27a Female thread 28 DC input terminal block 29, 31 AC Output terminal blocks 30, 35, 44 Screw member 32 Holding portions 33, 34 Bus bars S1, S2, S3 Storage spaces 40a to 40e Holding protrusions 40f to 40i Holding protrusions 40j to 40m Holding protrusions 41 Lead frame insertion slits 43 Circuit components QL Reverse conducting IGBT module QL Reverse conducting IGBT module

Claims (7)

A power semiconductor module for power conversion;
A control circuit board mounted with circuit components for driving the power semiconductor module,
A metal housing provided with a storage space for storing the power semiconductor module and the control circuit board,
A cooling medium in which a cooling medium circulates,
An opening communicating the outside of the housing and the storage space is formed in the housing,
In the housing, at a position of the storage space facing the opening, a holding portion provided with a plurality of holding protrusions on a side for fixing the control circuit board is integrally formed,
By fixing the cooler joined with the power semiconductor module to the periphery of the opening from the outside of the housing in a detachable manner, the holding portion is arranged along the power semiconductor module,
The power conversion device, wherein the control circuit board is fixed to the tops of the plurality of holding protrusions in a state where a gap is provided between the control circuit board and an opposing surface of the holding unit. The power converter according to claim 1, wherein the control circuit board and the plurality of holding protrusions are fixed by screw fastening means . Said plurality of retaining projections, power converter according to claim 1 or 2, characterized in that it is fixed to the center portion of the rectangular plate of the control circuit board at four corners and a plan view of the control circuit board . It said plurality of retaining projections, power conversion according to any one of claims 1 to 3, characterized in that it is fixed to the control circuit board so as to be positioned around the circuit component in a plan view apparatus. The power converter according to claim 3 , wherein the three or more holding protrusions are fixed at predetermined intervals on each of four sides of the control circuit board having a square plate shape . The power converter according to any one of claims 1 to 5, wherein the housing is formed of any one material of aluminum, an aluminum alloy, copper, and a copper alloy . The power converter according to any one of claims 1 to 6, wherein the cooler is formed of any one material of aluminum, an aluminum alloy, copper, and a copper alloy .

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