WO2023188551A1

WO2023188551A1 - Power semiconductor module and power conversion apparatus

Info

Publication number: WO2023188551A1
Application number: PCT/JP2022/044811
Authority: WO
Inventors: 独志西森; 典生中里; 宇幸串間; 康二佐々木
Original assignee: 株式会社日立パワーデバイス
Priority date: 2022-03-28
Filing date: 2022-12-06
Publication date: 2023-10-05
Also published as: JP2023144350A

Abstract

Provided is a power semiconductor module comprising two power semiconductor chips, an insulating substrate on which these power semiconductor chips are provided, and a base plate on which the insulating substrate is provided, in which first fins are provided to portions, on a cooling surface which is a reverse surface of the base plate to the surface of the side the power semiconductor chips are provided on, corresponding to the two mounting regions where the two power semiconductor chips are respectively provided, and a separation region is provided between the two mounting regions, wherein a flow path resistance of a cooling medium in a portion, on the cooling surface of the base plate, corresponding to the separation region, is larger in a direction parallel to a surface facing the two mounting regions than in a direction orthogonal to a surface facing the two mounting regions. Thereby, it is made possible to select the direction in which cooling water is made to flow in a power semiconductor module having a separation region between two mounting regions. Moreover, it is made easy to make design changes to the mounting dimensions of an electric power conversion device comprising the power semiconductor module.

Description

Power semiconductor modules and power conversion devices

The present disclosure relates to a power semiconductor module and a power conversion device.

As a control device for a drive motor of a railway vehicle, there are a device (converter) that uses power semiconductor elements to convert the contact line voltage from alternating current to direct current, or a device that converts direct current to alternating current (inverter). Since power semiconductor elements generate heat due to loss during conversion, it is necessary to appropriately cool the power semiconductor elements to suppress temperature rise. The cooling method is selected depending on the load, such as high-speed vehicle operation or commuter vehicle operation, and for high-speed vehicles with large loads, a water cooling system that can efficiently cool the vehicle may be used.

In conventional water cooling technology for power semiconductor modules in which multiple power semiconductor elements are installed, a heat sink with radiation fins is attached to the power semiconductor module via, for example, thermal conductive grease, and the radiation fins are immersed in a cooling water flow path. This is a method of dissipating heat (indirect water cooling method). However, since thermal conductivity is lower than that of metal, thermally conductive grease has a large thermal resistance, which hinders the suppression of temperature rise.

On the other hand, power semiconductor modules are known that use a method (direct water cooling method) in which heat is transferred from the power semiconductor elements to cooling water without using thermal conductive grease to ensure higher cooling capacity. . According to the direct water-cooled power semiconductor module, a power semiconductor element is installed on one surface of a base plate with an insulating layer interposed therebetween, and a heat radiation fin is provided on the other surface. The power semiconductor module is fixed to the water channel forming body using bolts, screws, etc., and the opening of the water channel forming body is covered and closed by the heat dissipating fin forming surface of the base plate, so that the heat dissipating fin forming surface is cooled. Since it is directly cooled with water, it has the advantage that the heat generated by the power semiconductor element can be efficiently dissipated.

Furthermore, in order to increase the output of high-voltage inverters for railways and other systems with high system voltages, it is important to use multiple power semiconductor modules in parallel. Using multiple power semiconductor modules in parallel has the effect of reducing the current load per power semiconductor module and suppressing the temperature rise of the power semiconductor elements.

Patent Document 1 has a heat dissipation area for cooling, and in a planar layout, a first element mounting range, a second element mounting range, a first element mounting range, and a second element mounting range. A semiconductor device having a mounting range protrusion located within two element mounting ranges and a mounting range protrusion located within the separation range, the protrusion being directly fixed to the surface of the base plate, and the mounting range protrusion located within the separation range. A spaced apart range protrusion is disclosed, and the spaced apart range protrusion is composed of only one protrusion.

Japanese Patent Application Publication No. 2016-225339

When using the configuration described in Patent Document 1, when the cooling water flows only in the short side direction of the semiconductor device, the cooling water enters from the inlet side and is divided into left and right parts to efficiently cool the elements on the left and right sides. is possible. However, in this semiconductor device, when attempting to flow cooling water in the long side direction, the flow is obstructed by the protrusions located in the spaced apart range, making it impossible to effectively cool the element.

In addition, in a power unit in which a plurality of power semiconductor modules (semiconductor devices) are arranged in parallel, two adjacent power semiconductor modules may be arranged so that their long sides face each other, or they may be arranged so that their short sides face each other. There are possible cases.

The configuration described in Patent Document 1 is applicable when the long sides are arranged to face each other, but it is difficult to apply when the short sides are arranged to face each other. If the cooling water is arranged so that the short sides face each other and the cooling water is allowed to flow in the direction of the long sides, the flow will be obstructed by the spaced range protrusion, and the power semiconductor element will not be effectively cooled. Therefore, in the semiconductor device described in Patent Document 1, since the direction in which the cooling water flows is limited, there are few options regarding the arrangement of the plurality of power semiconductor modules that constitute the power unit, and it is thought that there is room for improvement.

The present disclosure increases options for the direction in which cooling water flows in a power semiconductor module that has a separated area between two mounting areas, and facilitates design changes in the mounting dimensions of a power conversion device including the power semiconductor module. The purpose is to

One aspect of the present disclosure includes two power semiconductor chips, an insulating substrate on which these power semiconductor chips are installed, and a base plate on which the insulating substrate is installed, and the power semiconductor chips on the base plate are installed. A first fin is installed on the cooling surface, which is the back side of the side surface, and corresponds to the two mounting areas where two power semiconductor chips are installed, and a first fin is installed between the two mounting areas. In a power semiconductor module provided with a separation area, the flow resistance of the cooling medium on the cooling surface of the base plate corresponding to the separation area is equal to two in the direction parallel to the surface where the two mounting areas face each other. The two mounting areas are larger than those in the direction perpendicular to the opposing surfaces.

Another aspect of the present disclosure includes two power semiconductor chips, an insulating substrate on which these power semiconductor chips are installed, and a base plate on which the insulating substrate is installed, and the power semiconductor chips on the base plate are A first fin is installed on the cooling surface, which is the back side of the installed side, and corresponds to the two mounting areas where the two power semiconductor chips are installed. A first configuration in which a cooling medium flows in a direction parallel to a surface where two mounting regions face each other in a power semiconductor module having a spaced region therebetween, and a first configuration in which a cooling medium flows in a direction parallel to a surface where two mounting regions face each other; A second configuration in which a cooling medium flows through the cooling medium can be selected.

According to the present disclosure, in a power semiconductor module having a separation area between two mounting areas, it is possible to select the direction in which cooling water flows. This makes it easy to change the design of the mounting dimensions of the power conversion device including the power semiconductor module.

FIG. 1 is a schematic configuration diagram showing a main power converter for a railway vehicle according to a first embodiment. 2 is a circuit diagram showing a converter 4 that constitutes the main power converter 10 of FIG. 1. FIG. 2 is a circuit diagram showing an inverter 5 that constitutes the main power converter 10 of FIG. 1. FIG. FIG. 1 is a schematic configuration diagram showing a cooling device for a power semiconductor module according to a first embodiment. 1 is an external perspective view showing an example of a power unit according to a first embodiment. FIG. 6 is a circuit diagram showing main parts of the power semiconductor module 100 of FIG. 5. FIG. 6 is an external perspective view showing the power semiconductor module 100 of FIG. 5. FIG. 8 is a side view of the power semiconductor module 100 in FIG. 7 in the BB direction. FIG. 8 is a side view of the power semiconductor module 100 of FIG. 7 in the CC direction. FIG. 8B is an exploded view of the power semiconductor module 100 shown in FIG. 8B. 9A is a plan view showing the element mounting surface of the base plate 130 of FIG. 9A. FIG. 9B is a plan view showing a radiation fin forming surface of the base plate 130 of FIG. 9B. FIG. 6 is an exploded perspective view of the power unit 53 of FIG. 5. FIG. 12 is a perspective view showing the flow direction of cooling water in the water channel forming body 70 of FIG. 11. FIG. 6 is a diagram showing a part of the AA cross section in FIG. 5. FIG. FIG. 7 is a plan view showing a radiation fin forming surface of a base plate 130 of a power semiconductor module 100 according to a second embodiment. 7 is a plan view showing a radiation fin forming surface of a base plate of a power semiconductor module according to Modification 1. FIG. 7 is a plan view showing a radiation fin forming surface of a base plate of a power semiconductor module according to modification example 2. FIG. FIG. 7 is a plan view showing a radiation fin forming surface of a base plate of a power semiconductor module according to Modification 3; FIG. 7 is a plan view showing a part of a radiation fin forming surface of a base plate of a power semiconductor module according to Modification Example 4; FIG. 7 is a plan view showing a part of a radiation fin forming surface of a base plate of a power semiconductor module according to modification 5; FIG. 7 is a plan view showing a part of a radiation fin forming surface of a base plate of a power semiconductor module according to Modification Example 6;

The present disclosure relates to a structure in which power semiconductor chips are modularized.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

(First embodiment)
In this embodiment, a direct water-cooled power semiconductor module used in a power conversion device will be described as an example.

FIG. 1 is a schematic configuration diagram showing a main power converter for a railway vehicle. The main power converter is a type of power converter that includes a power semiconductor module.

As shown in this figure, the main power converter 10 includes a converter 4 that is a rectifier circuit, an inverter 5, and a smoothing capacitor 3. Converter 4 and inverter 5 are connected by

DC wiring

40p, 40n. A smoothing capacitor 3 is provided between the

DC wirings

40p and 40n. Inverter 5 is connected to AC motor 6 through three-

phase AC wiring

40u, 40v, and 40w. Converter 4, inverter 5, smoothing capacitor 3, etc. constitute a power semiconductor module. The power semiconductor module is the main component of the main power conversion device 10.

AC power is supplied to the converter 4 from the overhead contact line 1 via the transformer 2. AC power is converted to DC power by converter 4. After rectification in the converter 4, the DC power smoothed by the smoothing capacitor 3 is applied to the inverter 5, where it is reversely converted into three-phase AC power having a desired voltage and frequency. The three-phase AC power is output to the AC motor 6 through three-

phase AC wiring

40u, 40v, and 40w. The AC motor 6 is driven at a desired rotational speed by output control of the inverter 5.

FIG. 2 is a circuit diagram showing the converter 4 that constitutes the main power converter 10 of FIG. 1.

As shown in FIG. 2, converter 4 includes a leg 35 and a converter control circuit 200. The leg 35 is provided for each phase, and includes a switching element 31 and a rectifying element 33 on the upper arm, and a switching element 32 and a rectifying element 34 on the lower arm, respectively. Each of the switching

elements

31 and 32 and the rectifying

elements

33 and 34 is a power semiconductor element. Converter control circuit 200 is configured to transmit drive signal 210 to switching

elements

31 and 32. Converter 4 is connected to transformer 2 through

AC wiring

40r, 40s.

The converter 4 converts the AC power input through the AC wirings 40r and 40s into DC power, and outputs it to the

DC wirings

40p and 40n. Inside the converter 4, legs 35 rectify the AC power. The switching

elements

31 and 32 receive the drive signal 210 and are driven.

In this figure, IGBTs (Insulated Gate Bipolar Transistors) are used as the switching

elements

31 and 32, and diodes are used as the

rectifier elements

33 and 34, but it is not limited to these, and other types of elements can also be applied. It is.

FIG. 3 is a circuit diagram showing the inverter 5 that constitutes the main power converter 10 of FIG. 1.

As shown in FIG. 3, the inverter 5 includes a leg 35 and an inverter control circuit 201. The leg 35 is provided for each output phase, and includes an upper arm switching element 31 and a rectifying element 33, and a lower arm switching element 32 and a rectifying element 34, respectively. The inverter control circuit 201 is configured to transmit a drive signal 211 to the

switching elements

31 and 32. Inverter 5 is connected to

DC wiring

40p, 40n.

The inverter 5 converts the DC power smoothed by the smoothing capacitor 3 and input via the

DC wirings

40p and 40n into three-phase AC power, and outputs it to the three-phase AC wirings 40u, 40v, and 40w. The switching

elements

31 and 32 of the inverter 5 receive and drive the drive signal 211.

Since the converter 4 and inverter 5 of the power semiconductor module include switching

elements

31 and 32 and rectifying

elements

33 and 34, heat is generated during the power conversion operation, and the temperature rises. In order to suppress this temperature rise, a cooling device is attached to the power semiconductor module.

FIG. 4 is a schematic configuration diagram showing a cooling device for a power semiconductor module.

In this figure, the cooling device 20 is configured to remove heat generated in a plurality of power units 53 (power conversion devices) using a cooling medium, and includes a pump 50, a low-temperature side distribution pipe 52, a high-temperature side merging pipe 55, It has a radiator 56, a fan 57, and a tank 59. In each of the plurality of power units 53, four power semiconductor modules 100 are arranged adjacent to each other in a row. In this example, the number of power units 53 is three. Therefore, it can be seen that the power unit 53 consisting of four parallel power semiconductor modules 100 is three parallel. Note that the number of power semiconductor modules 100 in parallel or the number of power units 53 in parallel may be changed depending on the rated output. Moreover, parallel/series can be set arbitrarily.

The circulating cooling medium removes heat from the power semiconductor module 100, allowing the power converter to operate stably. Water and an aqueous ethylene glycol solution are suitable as the cooling medium, but other liquids may also be used. Furthermore, the refrigerant is not limited to liquid, and gas may be used as the refrigerant. The following description will be made assuming that water is used as the cooling medium.

The low temperature cooling water 51 (liquid refrigerant) discharged from the pump 50 is distributed and sent to each power unit 53 by the low temperature side distribution pipe 52. The low-temperature cooling water 51 removes heat from the power semiconductor module 100 provided in each power unit 53. At this time, since the water temperature rises, the water becomes high-temperature cooling water 54. After flowing out of the power unit 53 , the high temperature cooling water 54 joins together through a high temperature side merging pipe 55 and is sent to the radiator 56 . The high-temperature cooling water 54 passing through the radiator 56 is cooled by exchanging heat with the cooling air 58 introduced by the fan 57, becomes low-temperature cooling water 51, and is sent to the pump 50. Therefore, the cooling water circulates through the closed circulation path as described above.

The volume change of the cooling water due to the temperature change of the cooling water in such a circulation path is absorbed by the tank 59.

FIG. 5 is an external perspective view showing an example of the power unit.

As shown in this figure, the power unit 53 includes four parallel power semiconductor modules 100 and a water channel forming body 70. The water channel forming body 70 is provided with a low temperature side cooling water joint 71 and a high temperature side cooling water joint 72.

FIG. 6 is a circuit diagram showing the main parts of the power semiconductor module 100 of FIG. 5.

As shown in FIG. 6, the power semiconductor module 100 includes switching

elements

31 and 32 and

rectifier elements

33 and 34. These elements are mounted on an insulating substrate. These elements are connected to form legs 35 shown in FIGS. 2 and 3. Further, the switching

elements

31 and 32 are connected to a gate terminal 110g. The gate terminal 110g controls turning on and off of the switching

elements

31 and 32. In addition, the power semiconductor module 100 is connected to a positive DC terminal 110p, a negative DC terminal 110n, and an AC terminal 110ac. These terminals are installed on an insulating substrate.

FIG. 7 is an external perspective view showing the power semiconductor module 100 of FIG. 5.

As shown in FIG. 7, the outer shell of the power semiconductor module 100 is composed of a base plate 130 that radiates heat generated by the power semiconductor elements to cooling water, and a casing 113 that protects the power semiconductor elements and the insulating substrate. ing.

A positive DC terminal 110p and a negative DC terminal 110n are arranged on one side of the power semiconductor module 100, and an AC terminal 110ac is arranged on the opposite side. These are heavy electrical terminals. In addition, a gate terminal 110g and a weak electric system electrode 111 are provided near the center as weak electric system terminals.

The base plate 130 has a through hole 114 for fixing the power semiconductor module to the water channel forming body 70 (FIG. 5) and a screw hole 112 for fixing the gate drive board.

The material for the base plate 130 is preferably one having a thermal conductivity greater than 100 W/mK, such as copper, aluminum, AlSiC, MgSiC, etc. A suitable material for the housing 113 is polyphenylene sulfide resin or the like.

FIG. 8A is a side view of the power semiconductor module 100 of FIG. 7 in the BB direction.

FIG. 8B is a side view of the power semiconductor module 100 of FIG. 7 in the CC direction.

As shown in FIG. 8A, a housing 113 is installed on the top of the base plate 130. A large number (for example, about 100 or more in total) of pin fins 131 (radiating fins), which are minute cylindrical projections, protrude from a surface 135 where the base plate 130 contacts the water channel forming body 70 (FIG. 5).

Further, as shown in FIG. 8B, a flat plate fin 132 is installed between the areas of the two pin fins 131.

FIG. 9A is an exploded view of the power semiconductor module 100 shown in FIG. 8B.

FIG. 9B is a plan view showing the element mounting surface of the base plate 130 of FIG. 9A.

As shown in FIG. 9A, the insulating substrate 102 on which the power semiconductor element 101 (power semiconductor chip) is installed is bonded to a single base plate 130 via a bonding material (not shown).

Furthermore, as shown in FIG. 9B, the element mounting surface of the base plate 130 is provided with roughly two power semiconductor element mounting areas 140 (also simply referred to as "mounting areas"). The power semiconductor element 101 is mounted in the power semiconductor element mounting area 140. A plurality of power semiconductor elements 101 may be mounted in each power semiconductor element mounting area 140. Each power semiconductor element mounting area 140 has a shape having a long side in the short side direction of the base plate 130. A separation area 142 in which no power semiconductor element is mounted is provided between the two power semiconductor element mounting areas 140. The spacing region 142 also has a shape with a long side in the direction of the short side of the base plate 130.

Furthermore, a screw hole 116 for fixing the housing 113 is provided.

FIG. 10 is a plan view showing the radiation fin forming surface (back surface) of the base plate 130 of FIG. 9B.

In FIG. 10, a large number of cylindrical pin fins 131 are formed in a portion of the element mounting surface of the base plate 130 that corresponds to the back side of the power semiconductor element mounting area 140. On the other hand, a plurality of flat fins 132 are formed in a portion corresponding to the back side of the separation area 142. The plurality of flat fins 132 are arranged parallel to the long side direction of the base plate 130.

The cylindrical pin fin 131 may be formed from the base plate 130 by forging. Further, a separately manufactured pin-shaped member may be joined to the base plate 130 by brazing or the like.

The flat plate fin 132 may be formed by forging. Further, a separately manufactured flat plate may be joined to the base plate 130 by, for example, brazing.

Furthermore, when the cooling water 60 (liquid refrigerant) flows in the short side direction as shown in this figure, the flat plate fins 132 act as baffles, so the cooling water 60 flows into the area where the pin fins 131 are provided. .

In this specification, the configuration in which the cooling medium flows in a direction parallel to the surfaces where the two mounting regions face each other as shown in this figure is referred to as a "first configuration." The first configuration is a configuration in which the cooling medium is divided into both parts of the cooling surface of the base plate 130 corresponding to the two mounting areas.

Further, the pin fin 131 is an example of a "first fin." The first fin is installed on the cooling surface, which is the back side of the side of the base plate 130 on which the power semiconductor chips are installed, and in a portion corresponding to the two mounting areas where the two power semiconductor chips are installed, respectively. has been done.

The pin fin 131 has a cross-sectional shape with fourfold symmetry.

The flat fin 132 is an example of a "second fin." The second fin is installed on the cooling surface of the base plate 130 at a portion corresponding to the separation area. The second fin has a long axis in a direction perpendicular to the surface where the two mounting areas face each other.

FIG. 11 is an exploded perspective view of the power unit 53 of FIG. 5.

As shown in FIG. 11, the power unit 53 is constructed by providing a power semiconductor module 100 via an O-ring 73 so as to close an opening 75 located on the upper surface of the water channel forming body 70. Power semiconductor module 100 is fixed by passing bolts through bolt holes 76 .

In this figure, an O-ring 73 is used as the sealing member, but other sealing materials may be used. When the O-ring 73 is used, the O-ring 73 does not come off from the O-ring groove 74 from the top surface during assembly, which improves assembly efficiency.

In summary, the power unit 53 (power converter) includes a power semiconductor module 100 and a water channel forming body 70, and the power semiconductor module 100 is configured to be cooled by a cooling medium flowing through the water channel forming body 70. There is.

The power conversion device has a plurality of power semiconductor modules 100, and has a configuration in which the plurality of power semiconductor modules 100 are installed in one water channel forming body 70.

FIG. 12 is a perspective view showing the flow direction of cooling water in the water channel forming body 70 of FIG. 11.

As shown in FIG. 12, the low temperature cooling water 51 flows into the water channel forming body 70 from the low temperature side cooling water joint 71. Inside the water channel forming body 70, the cooling water 60 flows in the direction in which the openings 75 are arranged in series. The cooling water 60 then becomes the high temperature cooling water 54 and flows out from the high temperature side cooling water joint 72.

As shown in FIG. 12, the outlet of the high temperature side cooling water joint 72 has a narrow flow path. The inlet of the low temperature side cooling water joint 71 into which the low temperature cooling water 51 flows also has a narrow flow path. On the other hand, the inter-adjacent module flow path 77 that connects the adjacent openings 75 inside the waterway forming body 70 is made as wide as the long sides of the openings 75 . Once the cooling water 60 flows through the area of the pin fins 131 and spreads, it is better to let the cooling water 60 flow with the same flow path width to maintain the flow velocity of forced convection without creating unnecessary flow path resistance. This is because heat exchange efficiency becomes higher.

FIG. 13 is a diagram showing a part of the AA cross section in FIG. 5.

As shown in FIG. 13, the flow path of the cooling water 60 is connected to the adjacent module flow path 77 through the pin fin 131 area, and the adjacent module flow path 77 is formed at a lower position than the pin fin 131 area. . In other words, the inter-adjacent module flow path 77 is formed at a position lower than the pin fin 131 below the O-ring 73 and the O-ring groove 74 .

The effects of the structure explained above will be explained.

In this embodiment, the cooling water 60 is caused to flow in the short side direction of the base plate 130 of the power semiconductor module 100, as shown in FIG.

As shown in FIG. 12, the cooling water 60 flows in from the low temperature side cooling water joint 71 side, and a total of four power semiconductor modules 100 (FIG. 11) are installed, and the cooling water 60 is formed between the power semiconductor modules 100 and the opening 75. The water flows through the space where the water is cooled, and flows out from the high temperature side cooling water joint 72.

In the first power semiconductor module, there is a low-temperature side cooling water joint 71 at the inlet of the flow path, the flow path is narrow, and the outlet is wide. In the second and third power semiconductor modules, both entrances and exits are wide. In the fourth power semiconductor module, the inlet is wide, and the outlet has a narrow flow path due to the high temperature side cooling water joint 72.

The flow of the cooling water 60 under each power semiconductor module and the cooling performance associated with the flow will be explained.

The first power semiconductor module will be explained.

The cooling water entering from the narrow entrance hits the flat plate fins 132 on the front as shown in Figure 10, and the flow is divided into left and right sides. Since the cooling water 60 flows around the pin fins 131 in the left and right power semiconductor element mounting areas 140, heat from the power semiconductor elements 101 can be efficiently removed.

Furthermore, since the flow of cooling water to the separated region 142 is suppressed by the flat plate fins 132, the separated region 142, where there is no power semiconductor element 101 (FIG. 9A) and whose temperature rise is small, is not cooled more than necessary.

Although a plurality of flat plate fins 132 are provided in the separated area 142, even if the flow is divided into left and right sides at the flat plate fin 132 closest to the inlet, if there is only one flat plate fin 132 near the inlet, the cooling water will not flow through the area of the pin fins 131. During this period, a certain amount of cooling water 60 begins to flow into the separation area 142. As shown in FIG. 10, by arranging the flat plate fins 132 not only in the immediate vicinity of the inlet but also in an overlapping manner, the cooling water 60 can be made to flow mainly through the region of the pin fins 131. Thereby, the flow of the cooling water 60 is biased toward the pin fin region, and the power semiconductor element 101 in the power semiconductor element mounting area 140 (FIG. 9B) can be efficiently cooled.

At the outlet of the cooling water 60 that has passed through the region of the pin fins 131, the width of the flow path is wide and there is no obstacle to the flow, such as the pin fins 131 or flat plate fins 132, so the cooling water 60 flows through the flow path 77 between adjacent modules. During the process of flowing, the flow velocity becomes uniform.

The second and third power semiconductor modules will be explained.

In the second and third power semiconductor modules, the width of the flow path is widened on both the inlet side and the outlet side.

On the inlet side, as described above, the flow velocity of the cooling water 60 entering from the wide flow path is uniform. Since the flat plate fins 132 act as resistance for the cooling water 60 heading toward the separation region 142 , the flow is divided into left and right sides and flows into the region of the pin fins 131 . Further, the behavior of the cooling water 60 flowing into the pin fin 131 area is the same as that of the first power semiconductor module.

Since the cooling water 60 flows concentratedly in the area of the pin fins 131, the flow rate is fast, and it is possible to efficiently cool the power semiconductor element 101 in the power semiconductor element mounting area 140.

The fourth power semiconductor module will be explained.

In the fourth power semiconductor module, the channel width on the inlet side is wide and the channel width on the outlet side is narrow.

Similar to the second and third power semiconductor modules, the flow velocity of the cooling water 60 entering from the wide flow path is uniform. The behavior of the cooling water 60 that has flowed into the pin fin 131 region and the separation region 142 is similar to the first, second, and third power semiconductor modules. The cooling water 60 that has flowed toward the region of the pin fin 131 heads toward a narrow outlet where the high temperature side cooling water joint 72 is located.

In the case of the fourth power semiconductor module as well, since the cooling water 60 flows biased toward the pin fin 131 area, it is possible to efficiently cool the power semiconductor element 101 in the power semiconductor element mounting area 140.

That is, according to a configuration in which adjacent power semiconductor modules 100 are arranged so that their long sides face each other and the cooling water 60 is flowed in the direction of the short sides of the power semiconductor modules 100, as in the power unit 53 shown in FIG. In any of the power semiconductor modules 100 constituting the power unit 53, the cooling water 60 can be concentratedly flowed into the region of the pin fins 131, so that the power semiconductor elements 101 can be efficiently cooled.

(Second embodiment)
FIG. 14 is a plan view showing the radiation fin forming surface of the base plate 130 of the power semiconductor module 100 according to the second embodiment.

In this figure, the arrangement of pin fins 131 and flat plate fins 132 is the same as in FIG. 10. The difference is that the direction in which the cooling water 60 flows is changed from the short side direction of the power semiconductor module 100 to the long side direction. This is different from the direction shown in FIG. 11 in which the power semiconductor modules 100 are arranged to form a power unit, and the power semiconductor module 100 shown in FIG. They are arranged so that their short sides are adjacent. The other configurations are the same as those in FIG. 11, and their explanation will be omitted.

Next, the effects of the configuration shown in FIG. 14 will be explained.

The first power semiconductor module will be explained.

The cooling water 60 entering from the narrow entrance hits the pin fins 131 in the power semiconductor element mounting area 140 near the front as shown in FIG. The cooling water 60 flows into the area of the pin fins 131 in a substantially evenly distributed manner. Since the pin fins 131 are dense and the flow of the cooling water 60 is on the short side of the power semiconductor module, a flow velocity distribution is unlikely to occur in the flow in the long side direction. When the cooling water 60 flows in this direction, the flow is hardly obstructed by the flat plate fins 132 in the separation region 142. The cooling water 60 then flows almost uniformly even when it enters the region of the pin fins 131 on the outlet side. After flowing out from the area of the pin fins 131, the uniformity of the flow is maintained because the flow path is wide and there is nothing to obstruct the flow.

In other words, since the cooling water 60 flows almost uniformly in the area of the pin fins 131, the heat generated by the power semiconductor element 101 can be efficiently cooled. Further, in the separation region 142, there is no resistance due to the flat plate fins 132, so that the power for sending the cooling water 60 is not wasted.

The second and third power semiconductor modules will be explained.

On the inlet side, as described above, the flow velocity of the cooling water 60 entering from the wide flow path is uniform. Cooling water 60 flows into the region of pin fins 131 while maintaining a uniform flow. Then, the cooling water 60 passes through the separation region 142 and the region of the pin fins 131 on the outlet side and flows out while maintaining a uniform flow.

Therefore, since the cooling water 60 flows while maintaining a uniform flow in the area of the pin fins 131, the power semiconductor element 101 in the power semiconductor element mounting area 140 can be evenly cooled.

The fourth power semiconductor module will be explained.

In this specification, the configuration in which the cooling medium flows in a direction perpendicular to the surfaces where the two mounting areas face each other as shown in this figure is referred to as a "second configuration." In the second configuration, after the cooling medium flows through a portion of the cooling surface of the base plate 130 that corresponds to one of the two mounting areas, the cooling medium flows through a portion of the cooling surface of the base plate 130 that corresponds to one of the two mounting areas. After that, the cooling surface of the base plate 130 is configured to flow through a portion corresponding to the other of the two mounting areas.

As described above, the base plate 130 of the power semiconductor module 100 having the radiation fin forming surface shown in FIGS. 10 and 14 allows the cooling water 60 to flow in either the short side direction or the long side direction. The power semiconductor element mounting area 140 (FIG. 9B) can be uniformly cooled.

(Modification 1)
FIG. 15 is a plan view showing the radiation fin forming surface of the base plate of the power semiconductor module according to Modification Example 1.

The difference between this figure and FIG. 10 is that, instead of the flat fins 132 in FIG. 10, a plurality of fins 133 having a substantially elliptical cross-sectional shape are used per row. The other configurations are the same as those in FIG. 10, so their description will be omitted.

The effects of the configuration of this modification will be explained.

The effect regarding the flow of cooling water is the same as in the case of the flat plate fins 132, but when the fins 133 and the flat plate fins 132 have the same height, there is a gap between the approximately ellipses, so that the power semiconductor module When cooling water flows in the direction of the short side of 100, the amount of cooling water flowing through the separation area 142 increases, and the amount of cooling water flowing through the power semiconductor element mounting area 140 relatively decreases.

Therefore, although the cooling performance of the power semiconductor element mounting area 140 is reduced compared to the first embodiment, the cooling performance of the separation area 142 is improved.

In addition, when the cooling water flows in the long side direction as in the second embodiment, the flow in the power semiconductor element mounting area 140 is the same, so the cooling performance is the same, but in the separated area 142, The flow is disturbed because it has a substantially elliptical shape and the width of the flow path changes in the direction of travel. Therefore, in the separated region 142, the cooling performance is improved compared to the second embodiment.

Further, as in the case of the flat plate fins 132, the same cooling performance can be obtained whether the cooling water flows in the long side direction or the short side direction. Therefore, it is possible to provide a power semiconductor module in which the direction in which the cooling water flows can be selected between the long side direction and the short side direction, while the arrangement of the pin fins 131 remains the same.

Note that the fin 133 is an example of a second fin. The fins 133 have an elliptical cross-sectional shape, but may also have a rhombic shape. A plurality of fins 133 are arranged in a direction perpendicular to the surface where the two mounting areas face each other.

(Modification 2)
FIG. 16 is a plan view showing a radiation fin forming surface of a base plate of a power semiconductor module according to Modification 2. FIG.

The difference between this figure and FIG. 10 is that a cylindrical pin fin 131 is also provided in the separation area 142, and one flat plate fin 132 is arranged at each end of the separation area 142. The flat fin 132 is an example of a second fin. The other configurations are the same as those in FIG. 10, so their description will be omitted.

The effects of the configuration of this modification will be explained.

In FIG. 16, the fins in the spaced region 142 are composed of a pair of flat fins 132 and a plurality of cylindrical pin fins 131.

In this configuration, when cooling water flows in the short side direction of the power semiconductor module 100, the flow is divided into left and right by the nearest flat plate fin 132 on the inlet side, and the area of the pin fin 131 in the left and right power semiconductor element mounting areas 140 There is a biased inflow into the country.

The flow of cooling water gradually spreads to the left and right in the figure and flows into the separated area 142, but the flat plate fins 132 near the outlet cause the flow to flow again near the outlet of the power semiconductor element mounting area 140. It will be biased towards area 140.

Therefore, since the degree of flow bias is reduced compared to the first embodiment, the improvement in cooling performance of the power semiconductor element mounting area 140 is reduced.

On the other hand, when the cooling water flows in the long side direction of the power semiconductor module 100, the flow of the cooling water is the same as in the second embodiment, and the cooling performance of the power semiconductor element mounting area 140 is the same as in the second embodiment. is equivalent to On the other hand, in the separated region 142, since a large number of pin fins 131 are provided, the cooling performance is improved compared to the second embodiment.

(Modification 3)
FIG. 17 is a plan view showing a radiation fin forming surface of a base plate of a power semiconductor module according to Modification Example 3.

The difference between this figure and FIG. 10 is that fins 134 having a substantially square cross-sectional shape are used instead of the cylindrical pin fins 131 in FIG. The diagonal lines of the square forming the cross section of the fin 134 are in the long side direction and the short side direction of the power semiconductor module 100. The other configurations are the same as those in FIG. 10, so their description will be omitted.

Also in this modification, the same cooling effect as in the first embodiment and the second embodiment can be obtained.

Note that the fins 134 have a four-fold symmetrical cross-sectional shape.

(Modification 4)
FIG. 18 is a plan view showing a part of the radiation fin forming surface of the base plate of the power semiconductor module according to Modification Example 4.

The difference between this figure and FIG. 10 is that instead of the cylindrical pin fin 131 in FIG. It is that it is arranged. The four adjacent flat plate fins 184 are arranged radially at an angle of 45 degrees with respect to the long side direction (or short side direction) of the power semiconductor module 100. The other configurations are the same as those in FIG. 10, so their description will be omitted.

Note that the four adjacent flat plate fins 184 can be said to have a four-fold symmetrical cross-sectional shape when viewed as one body.

The base plate 130 of the power semiconductor module 100 having the radiation fin forming surface of this modification has the same flow path per unit length when the cooling water 60 is caused to flow in either the short side direction or the long side direction. Has resistance. Therefore, the power semiconductor element mounting area 140 (FIG. 9B) can be evenly cooled even when the cooling water 60 is caused to flow in either the short side direction or the long side direction. To be more precise, the heat transfer coefficients of the two power semiconductor element mounting regions 140 can be made almost equal even when the cooling water 60 is caused to flow in either the short side direction or the long side direction.

Therefore, in this modification as well, the same cooling effect as in the first embodiment and the second embodiment can be obtained.

(Modification 5)
FIG. 19 is a plan view showing a part of the radiation fin forming surface of the base plate of the power semiconductor module according to Modification Example 5.

The difference between this figure and FIG. 18 is that fins 194 having a substantially elliptical cross-sectional shape are used instead of the flat fins 184 in FIG. 18. The other configurations are the same as those in FIG. 18, so their description will be omitted.

Note that the four adjacent fins 194 can be said to have a four-fold symmetrical cross-sectional shape when viewed as a whole.

In this modification as well, the heat transfer coefficients of the two power semiconductor element mounting regions 140 can be made approximately equal regardless of whether the cooling water 60 is caused to flow in either the short side direction or the long side direction.
Therefore, the same cooling effect as in the first embodiment and the second embodiment can be obtained.

(Modification 6)
FIG. 20 is a plan view showing a part of the radiation fin forming surface of the base plate of the power semiconductor module according to Modification Example 6.

The difference between this figure and FIG. 18 is that

flat fins

204a and 204b are used instead of the flat fin 184 in FIG. In FIG. 20, the

flat plate fins

204a and 204b are arranged so that extension lines of their long sides are perpendicular to the other long side. The other configurations are the same as those in FIG. 18, so their description will be omitted.

Note that the four adjacent

flat plate fins

204a and 204b can be said to have a four-fold symmetrical cross-sectional shape when viewed as a unit.

Note that in the above embodiments and modifications, two power semiconductor element mounting areas 140 are arranged in the long side direction of the power semiconductor module 100, and a separation area 142 is provided between the two power semiconductor element mounting areas 140. Although the configuration has been described, the power semiconductor module and power conversion device of the present disclosure are not limited to such a configuration, and two power semiconductor element mounting areas are arranged in the short side direction of the power semiconductor module. It may be a configuration. Alternatively, the dimensions of the power semiconductor module in the long side direction and the short side direction may be equal, and the shape of the plan view may be a square. This is simply a matter of size. In this way, even if the dimensions are different from the above-described embodiments and modifications, the technical content of the present disclosure regarding the configuration of the fins etc. provided in the mounting area and the separation area, the configuration of the cooling medium flow path, etc. Applicable.

Although the above-described embodiments and modifications are exemplified by main power converters for railway vehicles, the technology of the present disclosure is not limited to this example, and is applicable to power converters for automobiles, trucks, etc. Power conversion devices for ships and aircraft, industrial power conversion devices used as control devices for electric motors that drive factory equipment, and domestic power conversion devices used for control devices for electric motors that drive home solar power generation systems and home appliances. It can also be applied to power converters.

The above-described embodiments and modified examples are for explaining the contents of the present disclosure in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace some of the configurations of each embodiment with other configurations.

1: Electrical line, 2: Transformer, 3: Smoothing capacitor, 4: Converter, 5: Inverter, 6: AC motor, 10: Main power converter, 31, 32: Switching element, 33, 34: Rectifying element, 35 : Leg, 50: Pump, 51: Low-temperature cooling water, 52: Low-temperature side distribution pipe, 53: Power unit, 54: High-temperature cooling water, 55: High-temperature side merging pipe, 56: Radiator, 57: Fan, 58: Cooling air, 59: Tank, 60: Cooling water, 70: Channel forming body, 71: Low temperature side cooling water joint, 72: High temperature side cooling water joint, 73: O ring, 74: O ring groove, 75: Opening, 76: Bolt hole, 77: Channel between adjacent modules, 100: Power semiconductor module, 101: Power semiconductor element, 102: Insulating substrate, 110p: Positive DC terminal, 110n: Negative DC terminal, 110ac: AC terminal, 110g: Gate terminal, 111: Weak electric system electrode, 112: Screw hole for fixing gate drive board, 113: Housing, 114: Through hole, 130: Base plate, 131: Pin fin, 132: Flat plate fin, 133, 134: Fin, 135: Surface, 140: Power semiconductor element mounting area, 142: Separation area, 200: Converter control circuit, 201: Inverter control circuit.

Claims

two power semiconductor chips,
An insulated substrate on which these power semiconductor chips are installed, and a base plate on which the insulated substrate is installed,
A cooling surface that is the back side of the side on which the power semiconductor chips are installed on the base plate, and which corresponds to the two mounting areas where the two power semiconductor chips are installed, has a first cooling surface. fins are installed,
In a power semiconductor module in which a separation area is provided between the two mounting areas,
The flow resistance of the cooling medium in the portion of the cooling surface of the base plate that corresponds to the separation area is, in the direction parallel to the surface where the two mounting areas face each other, A power semiconductor module characterized by being larger in the direction perpendicular to the plane.
two power semiconductor chips,
An insulated substrate on which these power semiconductor chips are installed, and a base plate on which the insulated substrate is installed,
A cooling surface that is the back side of the side on which the power semiconductor chips are installed on the base plate, and which corresponds to the two mounting areas where the two power semiconductor chips are installed, has a first cooling surface. fins are installed,
In a power semiconductor module in which a separation area is provided between the two mounting areas,
a first configuration in which a cooling medium flows in a direction parallel to surfaces where the two mounting areas face each other;
A power semiconductor module characterized in that a second configuration in which the cooling medium flows in a direction perpendicular to the surface where the two mounting areas face each other can be selected.
The first configuration is a configuration in which the cooling medium is divided into both parts of the cooling surface of the base plate corresponding to the two mounting areas,
In the second configuration, after the cooling medium flows through a portion of the cooling surface of the base plate that corresponds to one of the two mounting areas, the cooling medium flows through the cooling surface of the base plate. 3. The power according to claim 2, wherein the power flows through a portion corresponding to the separation area, and then flows through a portion of the cooling surface of the base plate that corresponds to the other of the two mounting areas. semiconductor module.
A second fin is installed on the portion of the cooling surface of the base plate that corresponds to the separation area,
The power semiconductor module according to claim 1 or 2, wherein the second fin has a long axis in a direction perpendicular to the surface on which the two mounting regions face each other.
The power semiconductor module according to claim 1 or 2, wherein the first fin has a cross-sectional shape with four-fold symmetry.
The power semiconductor module according to claim 1 or 2, wherein the first fin has a circular or square cross-sectional shape.
The power semiconductor module according to claim 4, wherein the second fin has an elliptical, rhombic, or rectangular cross-sectional shape.
5. The power semiconductor module according to claim 4, wherein a plurality of the second fins are arranged in a direction parallel to the surface where the two mounting regions face each other.
The power semiconductor module according to claim 4, wherein the second fins have an elliptical or rhombic cross-sectional shape, and a plurality of the second fins are arranged in a direction perpendicular to the surface where the two mounting regions face each other.
The power semiconductor module according to claim 1 or 2,
A water channel forming body;
The power converter device is configured such that the power semiconductor module is cooled by the cooling medium flowing through the water channel forming body.
having a plurality of the power semiconductor modules;
The power conversion device according to claim 10, having a configuration in which the plurality of power semiconductor modules are installed in one of the waterway forming bodies.