Power conversion device

Abstract

To obtain a power conversion device with a smaller size and a lower cost, while securing vibration resistance.SOLUTION: A power conversion device comprises: a plurality of rectangular parallelepiped power modules that each have a semiconductor chip, are arranged side by side, and each have a first face, a second face on the side opposite to the first face, and four faces surrounding the first face and the second face; a base plate that is arranged at a distance from the second faces of the plurality of power modules, and is electrically connected to a module terminal of each of the plurality of power modules; and a base plate holding member that is arranged in an interval between the base plate and the plurality of power modules, holds the base plate, and is made of a resin member having insulation quality. The plurality of power modules are arranged in a direction parallel with third faces. The module terminal protrudes from at least one face of the second face of the power module, the third face of the power module, and a fourth face on the side opposite to the third face, and then extends in a direction of the base plate. A portion of the module terminal extending in the direction of the base plate penetrates a through hole of the base plate holding member.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present application relates to a power conversion device. [Background technology]

[0002] Electrified vehicles such as hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs, PHEVs), electric vehicles (EVs), and fuel cell vehicles (FCVs) are equipped with power conversion devices, which are components for electrification. Examples of power conversion devices include inverters that convert DC power from a battery into AC power for a motor and supply the AC power to the drive motor, and converters that boost the battery voltage. In recent years, there has been a demand for cost reduction in power conversion devices.

[0003] In addition, in HVs, PHVs, and PHEVs, in addition to the engine, a power conversion device is installed in the engine room. Therefore, there is a tendency for a small power conversion device to be required. In addition, even in EVs, a drive motor and an inverter may be installed on the rear side, so there is a tendency for a small power conversion device to be required in order to secure the trunk room and living space for the passengers.

[0004] In recent years, in order to shorten the connection harness of each power conversion device, the number of cases of each power conversion device is reduced, and in order to reduce costs and size, power conversion devices such as inverters are increasingly directly rigidly connected to the cases of motors, engines, transmissions, etc. Therefore, the internal parts of the power conversion device are required to withstand strict vibration specifications. The structure of a general power conversion device that can withstand strict vibration specifications has been disclosed (see, for example, Patent Document 1). In the structure disclosed in Patent Document 1, a board is directly fixed to a base member, which is a heat dissipation member, by a support member. Therefore, the vibration resistance of the board and the parts mounted on the board is ensured. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6369355 Summary of the Invention [Problem to be solved by the invention]

[0006] There are various possible layouts for the power conversion device of an electric vehicle, for example, an inverter. In one layout, the power modules of the UVW phases are arranged on a cooler, a board is provided vertically above the power modules, and terminals for controlling the power modules extend from the power modules to the board. In order to minimize the mounting area of ​​the power modules on the cooler, it is not possible to provide a sufficient gap between two adjacent power modules. Since the boss fixing portion for fixing the board described in the above Patent Document 1 cannot be provided on the cooler, there is a problem that it is difficult for the board and the components mounted on the board to withstand the vibration specifications.

[0007] In the above Patent Document 1, since the board is fixed to the base member, the board and the components mounted on the board can withstand strict vibration specifications. However, since the board is directly fixed to the base member, space is required to fix the board to the part of the base member facing the board, and the base member becomes large, which makes it difficult to reduce the size and cost of the power conversion device.

[0008] Therefore, an object of the present application is to provide a power conversion device that is compact and low-cost while ensuring vibration resistance. [Means for solving the problem]

[0009] The power conversion device disclosed in the present application comprises: a plurality of rectangular parallelepiped power modules each having a semiconductor chip and arranged side by side, the power modules having a first surface, a second surface opposite the first surface, and four surfaces surrounding the first surface and the second surface, the third surface, a fourth surface, a fifth surface, and a sixth surface; a substrate arranged at intervals on the second surface of the plurality of power modules and electrically connected to module terminals of each of the plurality of power modules; and a substrate holding member arranged at intervals between the substrate and the plurality of power modules, the substrate holding member being made of an insulating resin member and holding the substrate; the plurality of power modules are arranged in a direction parallel to the third surface, and the module terminals protrude from at least one of the second surface of the power modules, the third surface of the power modules, and the fourth surface opposite the third surface, and then extend toward the substrate, and the portions of the module terminals extending toward the substrate pass through through holes in the substrate holding member. Effect of the Invention

[0010] According to the power conversion device disclosed in the present application, the power conversion device includes a plurality of rectangular parallelepiped power modules having a semiconductor chip and arranged side by side, the plurality of power modules having a first surface, a second surface opposite to the first surface, and four surfaces surrounding the first surface and the second surface, a substrate arranged at intervals on the second surface of the plurality of power modules and electrically connected to module terminals of each of the plurality of power modules, and a substrate holding member arranged at intervals between the substrate and the plurality of power modules and made of an insulating resin member, the plurality of power modules are arranged in a direction parallel to the third surface, the module terminals protrude from at least one of the second surface of the power module, the third surface of the power module, and a fourth surface opposite to the third surface, and then extend toward the substrate, and the portion of the module terminal extending toward the substrate passes through a through hole of the substrate holding member, so that the substrate is held by the substrate holding member arranged at the intervals between the substrate and the plurality of power modules, and therefore the vibration resistance of the substrate and the components mounted on the substrate can be ensured. Since there is no need to hold the substrate with a gap between the power modules arranged side by side, the power conversion device can be made smaller and less expensive. Since the module terminals pass through the through holes of the board holding member and are connected to the board, the module terminals can be shortened, and therefore the power conversion device can be made smaller and less expensive. [Brief description of the drawings]

[0011] [Figure 1] 1 is an exploded perspective view showing an outline of a power conversion device according to a first embodiment. [Diagram 2] 1 is a perspective view showing an outline of a power conversion device according to a first embodiment. [Diagram 3] 3 is a cross-sectional view of the power converter taken along the line AA in FIG. 2. [Figure 4] 3 is a cross-sectional view of the power conversion device taken along the line BB in FIG. 2. [Diagram 5] 1 is a perspective view showing a power module of a power conversion device according to a first embodiment. [Figure 6] 2 is a perspective view showing a drive circuit board for the power conversion device according to the first embodiment. FIG. [Figure 7] 2 is a perspective view showing a control circuit board of the power converter according to the first embodiment. FIG. [Figure 8] 1 is a diagram illustrating an example of an installation state of a power conversion device according to a first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a power conversion device according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding members and parts are denoted by the same reference numerals.

[0013] Embodiment 1 FIG. 1 is an exploded perspective view showing an outline of a power converter 1 according to a first embodiment, FIG. 2 is a perspective view showing an outline of the power converter 1, FIG. 3 is a cross-sectional view of the power converter 1 cut at the AA cross section position in FIG. 2, FIG. 4 is a cross-sectional view of the power converter 1 cut at the BB cross section position in FIG. 2, FIG. 5 is a perspective view showing a power module 2 of the power converter 1, FIG. 6 is a perspective view showing a drive circuit board 3b of the power converter 1, FIG. 7 is a perspective view showing a control circuit board 3a of the power converter 1, and FIG. 8 is a diagram showing an example of an installation state of the power converter 1. The power converter 1 is a device that converts an input current from DC to AC, AC to DC, or converts an input voltage into a different voltage. In this embodiment, the power converter 1 will be described as an inverter that converts DC power into power using a power module 2 to output a three-phase AC. The configuration of the power converter 1 is not limited to this.

[0014] <Power conversion device 1> As shown in FIG. 1, the power converter 1 includes a plurality of power modules 2, a substrate 3, and a substrate holding member 4. The power modules 2 have semiconductor chips 10 (not shown in FIG. 1) and are arranged side by side. As shown in FIG. 5, each of the power modules 2 is a rectangular parallelepiped having a first surface 2a, a second surface 2b opposite to the first surface 2a, and four surfaces surrounding the first surface 2a and the second surface 2b, that is, a third surface 2c, a fourth surface 2d, a fifth surface 2e, and a sixth surface 2f. As shown in FIG. 1, the substrate 3 is arranged on the second surfaces 2b of the plurality of power modules 2 at intervals, and is electrically connected to a module terminal 2g of each of the plurality of power modules 2. The substrate holding member 4 is arranged in the interval between the substrate 3 and the plurality of power modules 2, and holds the substrate 3. The substrate holding member 4 is made of an insulating resin member.

[0015] The number of the substrates 3 is not limited to one, and in this embodiment, the power converter 1 has two substrates 3. The two substrates 3 are a substrate 3a for a control circuit and a substrate 3b for a drive circuit. The power modules 2 are arranged in a direction parallel to the third surface 2c. In the figure, the direction parallel to the third surface 2c is the X direction. The module terminals 2g protrude from at least one of the second surface 2b of the power module 2, the third surface 2c of the power module 2, and the fourth surface 2d opposite to the third surface 2c, and then extend toward the substrate 3. The part of the module terminals 2g extending toward the substrate 3 penetrates the through hole 4a of the substrate holding member 4 as shown in FIG. 4. In this embodiment, one module terminal 2g is provided on each of the third surface 2c and the fourth surface 2d of the power module 2, and is connected to the substrate 3b for a drive circuit. The arrangement surface of the power module 2 on which the module terminals 2g are arranged, the number of the module terminals 2g, and the substrate 3 to which the module terminals 2g are connected are not limited to those mentioned above. In this embodiment, the substrate 3 is held by a connection terminal 4c provided on the substrate holding member 4. The connection terminal 4c for holding the substrate 3 will be described in detail later.

[0016] With this configuration, the substrate 3 is held by the substrate holding member 4 arranged in the space between the substrate 3 and the plurality of power modules 2, so that it is possible to ensure the vibration resistance of the substrate 3 and the components mounted on the substrate 3. Since it is not necessary to hold the substrate 3 with a gap between the power modules 2 arranged side by side, it is possible to reduce the size and cost of the power conversion device 1. Since the module terminal 2g passes through the through hole 4a of the substrate holding member 4 and is connected to the substrate 3, it is possible to shorten the module terminal 2g, so that it is possible to reduce the size and cost of the power conversion device 1. Furthermore, since the module terminal 2g is shortened, it is possible to shorten the distance between the power module 2 and the drive circuit, so that it is possible to improve the controllability of the power module 2.

[0017] The module terminal 2g is connected to the drive circuit board 3b through a through hole 3g provided in the drive circuit board 3b. In this embodiment, the through hole 4a is a funnel shape in which the opening on the side of the multiple power modules 2 is larger than the opening on the side of the drive circuit board 3b. With this configuration, an additional guide part for guiding the module terminal 2g to the through hole 3g, which is required when connecting the module terminal 2g to the through hole 3g, is not required, so that the distance between the power module 2 and the drive circuit board 3b can be shortened. Since the distance between the power module 2 and the drive circuit board 3b is shortened, the distance between the power module 2 and the drive circuit can be shortened, so that the controllability of the power module 2 can be improved. In addition, since the height of the power conversion device 1 is reduced, the power conversion device 1 can be made smaller in size.

[0018] <Cooler 9, housing 6, film capacitor 5> As shown in FIG. 1, the power converter 1 further includes a cooler 9, a housing 6, and a film capacitor 5. The cooler 9 has a cooling surface 9a to which the first surfaces 2a of the power modules 2 are thermally connected. As shown in FIG. 3, the cooler 9 has a flow path portion 9b through which a coolant flows. The cooling surface 9a is formed in a lid portion 9c that covers the flow path portion 9b. For example, water or ethylene glycol liquid is used as the coolant. As shown in FIG. 1, the housing 6 has the cooler 9 and has an arrangement surface 6a on the same side as the side on which the cooling surface 9a is provided. In this embodiment, the cooling surface 9a and the arrangement surface 6a are provided on the same plane. The housing 6 is made of a metal such as aluminum by die casting. The lid portion 9c is, for example, a forged aluminum alloy. The film capacitor 5 is electrically connected to the power modules 2 via a bus bar 7. The film capacitor 5 is adjacent to the power modules 2 and thermally connected to the arrangement surface 6a of the housing 6. The multiple power modules 2 and the film capacitor 5 are cooled by a cooler 9. The bus bar 7 is connected to the power terminals 2h of the power modules 2 by, for example, welding.

[0019] The arrangement surface 6a has a boss fixing portion 6b to which the fixing boss 4b of the substrate holding member 4 is fixed. The boss fixing portion 6b is provided on a portion of the arrangement surface 6a excluding the cooling surface 9a and the projection portion of the arrangement surface 6a where the film capacitor 5 and the busbar 7 are projected onto the arrangement surface 6a. The fixing boss 4b and the boss fixing portion 6b are fixed, for example, by screwing. With this configuration, the substrate holding member 4 holding the substrate 3 is fixed to a portion of the arrangement surface 6a excluding the cooling surface 9a and the projection portion of the arrangement surface 6a where the film capacitor 5 and the busbar 7 are projected onto the arrangement surface 6a. Therefore, it is not necessary to provide the boss fixing portion 6b between the power modules 2 arranged side by side, between the cooling surface 9a on which the flow path portion 9b is provided, and between the power module 2 and the film capacitor 5. Since it is not necessary to provide the boss fixing portion 6b between the power modules 2 arranged side by side, between the cooling surface 9a, and between the power module 2 and the film capacitor 5, it is possible to reduce the size and cost of the power conversion device 1. Since the board 3 is held by the board holding member 4, the vibration resistance of the board 3 and the components mounted on the board 3 can be ensured.

[0020] Furthermore, since the substrate 3 is installed at a position that does not overlap with the film capacitor 5, which is a tall component, when viewed in a direction perpendicular to the second surface 2b of the multiple power modules 2, there is no wasted space, and the height of the power conversion device 1 can be reduced. The fixing location of the substrate holding member 4 is not limited to the arrangement surface 6a of the housing 6. For example, when the power module 2 is configured such that the semiconductor chip 10 is housed in a case and the inside of the case is filled with gel, a boss fixing portion may be provided on the inside of the case, on the substrate holding member 4 side.

[0021] <Power module 2> The power module 2 will be described. In FIG. 5, one semiconductor chip 10 is indicated by a broken line. The number of semiconductor chips 10 included in one power module 2 is not limited to one, and the power module 2 may include a plurality of semiconductor chips 10. The power module 2 converts DC power to output three-phase AC. In this embodiment, as shown in FIG. 1, the power conversion device 1 includes three power modules 2 corresponding to the respective phases. The number of power modules 2 included in the power conversion device 1 is not limited to this. The number of power modules 2 may be two, or may be four or more. The first surface 2a of the power module 2 is thermally connected to the cooling surface 9a via a bonding member (not shown). The bonding member is, for example, solder.

[0022] The multiple power modules 2 are arranged in the same direction in the X direction, which is a direction parallel to the third surface 2c. With this configuration, the multiple power modules 2 are aligned in the same direction, so that the power conversion device 1 can be made smaller. When further multiple power modules 2 are provided, the power modules 2 may be aligned in two rows.

[0023] The module terminal 2g and the power terminal 2h are made of, for example, copper having low electrical resistivity and excellent conductivity. The module terminal 2g is a terminal related to driving the power module 2. The power terminal 2h is a terminal related to input / output of the power module 2. For example, one power terminal 2h is connected to a DC power source, and the other power terminal 2h is connected to a motor, which is a load. In this embodiment, one power terminal 2h is connected to a film capacitor 5 via a bus bar 7, and is connected to a DC power source (not shown) via the film capacitor 5. The film capacitor 5 smoothes the power input to the power module 2.

[0024] The power module 2 is molded by transfer molding. Therefore, the semiconductor chip 10 is covered with a molded resin. By configuring in this manner, the semiconductor chip 10 can be easily protected from the outside. In addition, it is difficult to hold the substrate 3 in the power module 2 molded by transfer molding. However, in the present application, since a substrate holding member 4 for holding the substrate 3 is provided, the vibration resistance of the substrate 3 can be improved even if the substrate 3 is not held in the power module 2. Note that the power module 2 is not limited to a configuration molded by transfer molding, and may be a configuration in which the semiconductor chip 10 is housed in a case and the inside of the case is filled with gel. Even if the semiconductor chip 10 is sealed with gel, the vibration resistance of the substrate 3 can be improved.

[0025] <Substrate holding member 4> The structure of the substrate holding member 4 for holding the substrate 3 will be described with reference to FIG. 4. The substrate holding member 4 has a connection terminal 4c mechanically connected to the substrate 3. The connection terminal 4c has an embedded portion 4c1 embedded in the substrate holding member 4 and an extension portion 4c2 extending toward the substrate 3 and connected to the substrate 3. The substrate 3 is held by the substrate holding member 4 through the connection terminal 4c. The connection terminal 4c is made of, for example, metal. In this embodiment, both the control circuit substrate 3a and the drive circuit substrate 3b are connected to a plurality of connection terminals 4c and held by the substrate holding member 4. In this embodiment, the connection terminal 4c is formed in a U-shape, with the bottom of the U being the embedded portion 4c1, and the extension portion 4c2 being formed at one end and the other end of the connection terminal 4c. The control circuit substrate 3a is connected to one end of the connection terminal 4c at a portion where the control circuit substrate 3a overlaps the substrate holding member 4 when viewed in a direction perpendicular to the second surface 2b of the plurality of power modules 2. The drive circuit board 3b is connected to the other end of the connection terminal 4c at a portion where the drive circuit board 3b overlaps the board holding member 4 when viewed in a direction perpendicular to the second surface 2b of the multiple power modules 2. The board 3 and the connection terminal 4c are connected by, for example, solder. The connection terminal 4c is provided on the board holding member 4 when, for example, the board holding member 4 is molded from resin.

[0026] With this configuration, the connection terminals 4c can be used as structural members for fixing the board 3 to the board holding member 4 without using fastening members such as bolts. When the board 3 is fixed by the connection terminals 4c, the board 3 can be fixed in a smaller area than when it is fixed by bolts, and therefore the power conversion device 1 can be made smaller. Furthermore, when the board 3 is fixed by the connection terminals 4c, the board 3 can be fixed in a shorter time in terms of manufacturing than when it is fixed by bolts, and therefore the assembly man-hours during manufacturing and assembly and the investment amount for assembly facilities can be reduced, and the productivity of the power conversion device 1 can be improved.

[0027] The effect of the above-mentioned configuration will be further explained. To improve the vibration resistance of the substrate 3, it is desirable to ensure the rigidity of the substrate 3. To ensure the rigidity of the substrate alone, it is necessary to increase the geometrical moment of inertia shown in formula (1). Specifically, it is necessary to increase the geometrical moment of inertia of the substrate 3 about the X direction, which is the longitudinal direction of the substrate 3. The calculation formula for the geometrical moment of inertia I of the rectangular cross section of the substrate 3 is shown in formula (1). I = b × h 3 / 12 ···(1) In formula (1), the width and height of the rectangle are b and h, respectively. In a structure with a rectangular cross section, the geometric moment of inertia can be increased by increasing the width b and height h. One method for increasing the geometric moment of inertia is to increase the thickness of the substrate 3, but making the substrate 3 thicker than is commonly available would result in an increase in the cost of the substrate 3.

[0028] Moreover, it is necessary to suppress the deflection of the substrate 3 in order to ensure the rigidity of the substrate 3. The calculation formula for the deflection δ at the center of the substrate 3 is shown in formula (2). δ = w × l 4 / (384×E×I) ···(2) In equation (2), w denotes the uniformly distributed load (the weight of substrate 3), l the length of the beam (the length of the longitudinal portion of substrate 3), E the Young's modulus, and I the second moment of area.

[0029] Since the length l of the beam depends on the size of the electrical components and the size of the circuit mounted on the substrate 3, it is difficult to reduce the length l of the beam. As described above, it is difficult to increase the second moment of area I. Therefore, the length l of the beam and the second moment of area I in formula (2) are limited in the configuration of the present application.

[0030] Other than increasing the thickness of the substrate 3, a method of increasing the geometrical moment of inertia can be considered, in which the substrate 3 is fixed to the substrate holding member 4 with bolts at many points, and the substrate 3 and the substrate holding member 4 are made into a single rigid member. However, increasing the number of fixing parts with bolts leads to an increase in the size of the power conversion device 1, an increase in the number of assembly steps during manufacturing and assembly, and an increase in the investment amount for assembly facilities.

[0031] In the configuration of the present application, the connection terminals 4c are provided on the board holding member 4 molded from resin, and the board 3 is fixed by the connection terminals 4c, so that the bending of the board 3 can be suppressed by the connection terminals 4c, which are structural members. In this embodiment, the board holding member 4 has a plurality of connection terminals 4c, and the plurality of connection terminals 4c are arranged in the longitudinal direction of the board 3, so that the bending of the board 3 can be further suppressed. Since the bending of the board 3 is suppressed, the vibration resistance of the board 3 and the components mounted on the board 3 can be improved.

[0032] In this embodiment, the connection terminal 4c is a wiring for an electric circuit. The connection terminal 4c is made of, for example, copper having excellent electrical conductivity. The connection terminal 4c and the substrate 3 are connected by, for example, solder, and the connection terminal 4c is used as wiring for the electric circuit of the power conversion device 1. Since the connection terminal 4c can be used as wiring for the electric circuit, the wiring pattern on the substrate 3 is reduced, and the power conversion device 1 can be made smaller.

[0033] In this embodiment, the power conversion device 1 has a plurality of substrates 3, the connection terminal 4c is mechanically connected to the plurality of substrates 3, and the portion of the connection terminal 4c is wiring for an electric circuit. When the power conversion device 1 is an inverter, the substrate used for the inverter is roughly divided into two functions, a control circuit section and a drive circuit section. When a substrate for the control circuit and a substrate for the drive circuit are prepared and each substrate is connected with a connector and a harness, the cost of the connector and the harness is added. In order to reduce the cost of the connector and the harness, the control circuit section and the drive circuit section can be provided on one substrate without dividing the substrate for the control circuit and the substrate for the drive circuit. When the control circuit section and the drive circuit section are provided on one substrate, the size of the substrate becomes large, so that the substrate is arranged on a component with a high component height so that the substrate does not interfere with a high electric component (for example, the film capacitor 5). In that case, a wasted space is generated between the substrate and a component with a low component height (for example, the power module 2).

[0034] In this embodiment, the power converter 1 has a control circuit board 3a and a drive circuit board 3b as the multiple boards 3. The number of the multiple boards 3 is not limited to two. Both the control circuit board 3a and the drive circuit board 3b are mechanically and electrically connected by the connection terminals 4c provided on the board holding member 4, so that the boards are not placed on top of the tall electric components, and both the control circuit board 3a and the drive circuit board 3b can be placed in the area of ​​the low electric components around the tall electric components. Since both the control circuit board 3a and the drive circuit board 3b are placed around the tall electric components, it is possible to eliminate the wasted space around the tall electric components, and therefore the power converter 1 can be made smaller. In addition, since a connector and a harness for connecting the boards to connect the two boards are not required, the power converter 1 can be made smaller and less expensive.

[0035] In this embodiment, the multiple boards 3 are arranged so that at least a portion of them overlap when viewed in a direction perpendicular to the second surfaces 2b of the multiple power modules 2. As shown in FIG. 1, the power conversion device 1 has a control circuit board 3a and a drive circuit board 3b as the multiple boards 3. The control circuit board 3a and the drive circuit board 3b overlap except for a portion of the control circuit board 3a that is connected to the connection terminal 4c. The overlapping area of ​​the control circuit board 3a and the drive circuit board 3b is not limited to this.

[0036] With this configuration, the area occupied by the board 3 in the power conversion device 1 can be reduced when viewed in a direction perpendicular to the second surface 2b of the multiple power modules 2, and the power conversion device 1 can be made smaller. Note that in the present application, an example in which the power conversion device 1 includes multiple boards 3 has been shown, but the number of boards 3 may be one as long as the increase in size of the power conversion device 1 is suppressed. Also, in the present application, an example in which the power conversion device 1 includes multiple boards 3 and the multiple boards 3 are arranged in an overlapping manner has been shown, but the multiple boards 3 may be arranged side by side without overlapping when viewed in a direction perpendicular to the second surface 2b of the multiple power modules 2 as long as the increase in size of the power conversion device 1 is suppressed.

[0037] In this embodiment, an additional board holding member 11 is provided between the overlapping boards 3, and the additional board holding member 11 holds at least one board 3. When the power conversion device 1 has a plurality of boards 3, as shown in FIG. 1, the power conversion device 1 may have an additional board holding member 11 between the overlapping control circuit board 3a and drive circuit board 3b. The additional board holding member 11 is made of an insulating resin member. The additional board holding member 11 has a board fixing portion 11a, and the fixing portion 3h of the control circuit board 3a is fixed to the board fixing portion 11a. In this embodiment, the board holding member 4 has a board fixing portion 4e, and the fixing portion 3h of the drive circuit board 3b is fixed to the board fixing portion 4e. These parts may be fixed together, and the fixing method is, for example, screwing.

[0038] With this configuration, an insulating additional board holding member 11 is provided between the control circuit board 3a and the drive circuit board 3b, so that the insulation between the control circuit board 3a and the drive circuit board 3b can be improved. The control circuit board 3a is held by the board fixing portion 11a of the additional board holding member 11 in addition to the connection terminal 4c, so that the vibration resistance of the control circuit board 3a and the components mounted on the control circuit board 3a can be further improved. In this embodiment, the additional board holding member 11 has a fixing boss 11c, and the fixing boss 11c is fixed to the boss fixing portion 6b together with the fixing boss 4b via the fixing auxiliary portion 3i of the drive circuit board 3b. The fixing method is, for example, screwing.

[0039] In this embodiment, the power conversion device 1 includes an AC bus bar 8a and an AC terminal 8 electrically connected to a plurality of power modules 2 via the AC bus bar 8a. The AC terminal 8 is arranged on the arrangement surface 6a opposite to the side of the film capacitor 5 of the plurality of power modules 2. The AC bus bar 8a is connected to the power terminal 2h of the power module 2, for example, by welding. An end of the AC bus bar 8a opposite to the side of the power terminal 2h is connected to, for example, a motor (not shown). As shown in FIG. 4, a board holding member 4 is provided at least partially between the drive circuit board 3b, which is the board 3, and the bus bar 7 and AC bus bar 8a. The bus bar 7 and AC bus bar 8a are high-voltage members.

[0040] With this configuration, insulating board holding member 4 is provided between drive circuit board 3b and the high-voltage portions of bus bar 7 and AC bus bar 8a, so that insulation between bus bar 7 and AC bus bar 8a and drive circuit board 3b can be ensured by board holding member 4. Since insulation between bus bar 7 and AC bus bar 8a and drive circuit board 3b is ensured, the distance between bus bar 7 and AC bus bar 8a and drive circuit board 3b can be shortened. Since the distance between bus bar 7 and AC bus bar 8a and drive circuit board 3b can be shortened, power conversion device 1 can be made smaller.

[0041] At least one of a transformer, an aluminum electrolytic capacitor, and a backup transformer, which are mounted components and electrically connected to the power module 2, is provided on the substrate 3. In this embodiment, as shown in Fig. 6, a transformer 3c and an aluminum electrolytic capacitor 3d are provided on the drive circuit substrate 3b. As shown in Fig. 7, a backup transformer 3e is provided on the control circuit substrate 3a. The transformer 3c and the aluminum electrolytic capacitor 3d are provided on the side of the drive circuit substrate 3b opposite to the side of the power module 2, and the backup transformer 3e is provided on the side of the power module 2 of the control circuit substrate 3a.

[0042] The portion of the mounted components facing the board holding member is bonded to the board holding member via adhesive 3f. In this embodiment, as shown in Fig. 3, the portion of the transformer 3c and the aluminum electrolytic capacitor 3d facing the additional board holding member 11 is bonded to the additional board holding member 11 via adhesive 3f. As shown in Fig. 4, the portion of the backup transformer 3e facing the additional board holding member 11 is bonded to the additional board holding member 11 via adhesive 3f.

[0043] With this configuration, the transformer 3c, the aluminum electrolytic capacitor 3d, and the backup transformer 3e are fixed to the additional board holding member 11, which is a board holding member, so that the vibration resistance of the board 3 and the electrical components mounted on the board 3 can be further ensured. Since the vibration resistance of the board 3 and the electrical components mounted on the board 3 is further ensured, the power conversion device 1 disclosed in the present application can be used in a power conversion device that is rigidly connected to an automobile motor, which has strict vibration resistance requirements. A rigid connection means that two members are mechanically connected without a vibration absorbing material, and is a connection that does not bend at the part where the two members are connected.

[0044] In this embodiment, as shown in Fig. 3, a recess 11b is provided in a portion of the additional substrate holding member 11 facing the transformer 3c and the aluminum electrolytic capacitor 3d, and the transformer 3c and the aluminum electrolytic capacitor 3d are bonded to the bottom of the recess 11b via an adhesive 3f. As shown in Fig. 4, a recess 11b is provided in a portion of the additional substrate holding member 11 facing the backup transformer 3e, and the backup transformer 3e is bonded to the bottom of the recess 11b via an adhesive 3f. With this configuration, the distance between the control circuit board 3a and the drive circuit board 3b can be shortened, and the power conversion device 1 can be made smaller.

[0045] As shown in FIG. 4, the substrate holding member 4 has a plate 4d made of metal inside. The plate 4d is provided on the substrate holding member 4, for example, when the substrate holding member 4 is molded from resin. The fixed boss 4b of the substrate holding member 4 and the housing 6 are made of metal, and the plate 4d, the fixed boss 4b, and the ground of the drive circuit board 3b, which is the substrate 3, are electrically connected. The potential of the housing 6 is the ground, and the potential of the plate 4d, the fixed boss 4b, and the ground of the drive circuit board 3b are the same as the potential of the housing 6. The plate 4d, the fixed boss 4b, and the ground of the substrate 3 are electrically connected using, for example, a connection terminal 4c. The plate 4d and the fixed boss 4b may be connected to each other by providing a connection wire 4f when the substrate holding member 4 is molded from resin.

[0046] By configuring in this way, it is possible to easily provide a ground pattern required for the transformer 3c connected to the drive circuit of the drive circuit board 3b. In addition, since the plate 4d is provided between the semiconductor chip 10 of the power module 2 and the drive circuit board 3b and is connected to the ground, the plate 4d can function as a noise shield that blocks noise generated when the semiconductor chip 10 is switched. Since the plate 4d functions as a noise shield, there is no need to add a new noise shield, and the productivity of the power conversion device 1 can be improved. In addition, since the plate 4d has a higher Young's modulus than the resin material of the board holding member 4, the rigidity of the board holding member 4 can be improved. In addition, since the rigidity of the board holding member 4 is improved, the vibration resistance of the board 3 fixed to the board holding member 4 and the electrical components mounted on the board 3 can be improved.

[0047] <Installation example of power conversion device 1> The power conversion device 1 is, for example, a device mounted on a vehicle 12. The vehicle 12 has a vibration source 13 such as an engine, a transmission, a motor, or an e-axle. As shown in FIG. 8, the housing 6 is rigidly connected to at least one of the engine, the transmission, the motor, and the e-axle, which are the vibration source 13 in the vehicle 12. In FIG. 8, the housing 6 is a portion indicated by a broken line. With the power conversion device 1 having the above-mentioned configuration, the vibration resistance of the power conversion device 1 can be ensured even if the housing 6 of the power conversion device 1 is rigidly connected to the vibration source 13 of the vehicle 12, which has strict vibration resistance requirements. In addition, the power module 2 can ensure the vibration resistance of the power conversion device 1 in a state in which the housing 6 of the power conversion device 1 is rigidly connected to the vibration source 13 of the vehicle 12, which has strict vibration resistance requirements, whether the power module 2 is configured by transfer molding or sealed with gel.

[0048] As described above, in the power conversion device 1 according to the first embodiment, the power modules 2 each having a semiconductor chip 10 and arranged side by side are rectangular parallelepiped-shaped and each having a first surface 2a, a second surface 2b opposite to the first surface 2a, and four surfaces surrounding the first surface 2a and the second surface 2b; a substrate 3 arranged at intervals on the second surfaces 2b of the power modules 2 and electrically connected to module terminals 2g of each of the power modules 2; and a substrate 3 arranged at an interval between the substrate 3 and the power modules 2, which holds the substrate 3 and is made of an insulating resin member. The power converter 1 includes a plate holding member 4, and the power modules 2 are arranged in a direction parallel to the third surface 2c. The module terminals 2g extend toward the substrate 3 after protruding from at least one of the second surface 2b, the third surface 2c, and the fourth surface 2d opposite to the third surface 2c. The module terminals 2g extend toward the substrate 3 through the through holes 4a provided in the substrate holding member 4. The substrate 3 is held by the substrate holding member 4 arranged in the space between the substrate 3 and the power modules 2. This ensures the vibration resistance of the substrate 3 and the components mounted on the substrate 3. Since it is not necessary to hold the substrate 3 with gaps provided between the power modules 2 arranged side by side, the power converter 1 can be made smaller and less expensive. The module terminals 2g are connected to the substrate 3 by penetrating the through holes 4a provided in the substrate holding member 4, and therefore the module terminals 2g can be shortened. The power converter 1 can be made smaller and less expensive.

[0049] When the arrangement surface 6a has a boss fixing portion 6b to which the fixing boss 4b of the substrate holding member 4 is fixed, and the boss fixing portion 6b is provided on the arrangement surface 6a excluding the cooling surface 9a and the projected portion of the arrangement surface 6a where the film capacitor 5 and the busbar 7 are projected onto the arrangement surface 6a, the substrate holding member 4 holding the substrate 3 is fixed to the arrangement surface 6a excluding the cooling surface 9a and the projected portion of the arrangement surface 6a where the film capacitor 5 and the busbar 7 are projected onto the arrangement surface 6a, so that it is not necessary to provide the boss fixing portion 6b between the power modules 2 arranged side by side, between the cooling surface 9a on which the flow path portion 9b is provided inside, and between the power module 2 and the film capacitor 5. Since it is not necessary to provide the boss fixing portion 6b between the power modules 2 arranged side by side, between the cooling surface 9a, and between the power module 2 and the film capacitor 5, it is possible to reduce the size and cost of the power converter 1. Since the substrate 3 is held by the substrate holding member 4, it is possible to ensure the vibration resistance of the substrate 3 and the components mounted on the substrate 3.

[0050] When the through-hole 4a is funnel-shaped with an opening on the side of the multiple power modules 2 larger than the opening on the side of the drive circuit board 3b, an additional guide part for guiding the module terminal 2g to the through-hole 3g is not required, so the distance between the power module 2 and the drive circuit board 3b can be shortened. Since the distance between the power module 2 and the drive circuit board 3b is shortened, the distance between the power module 2 and the drive circuit can be shortened, so the controllability of the power module 2 can be improved. In addition, since the height of the power conversion device 1 is reduced, the power conversion device 1 can be made smaller.

[0051] When the board 3 is held on the board holding member 4 by the connection terminals 4c, the connection terminals 4c can be used as a structural member for fixing the board 3 to the board holding member 4 without using fastening members such as bolts. When the board 3 is fixed by the connection terminals 4c, the board 3 can be fixed in a smaller area than when using bolts, and therefore the power conversion device 1 can be made smaller. Furthermore, when the board 3 is fixed by the connection terminals 4c, the board 3 can be fixed in a shorter time in terms of manufacturing than when using bolts, and therefore the assembly man-hours during manufacturing and assembly and the investment amount for assembly facilities can be reduced, and the productivity of the power conversion device 1 can be improved.

[0052] When the connection terminal 4c is a wiring for an electric circuit, the connection terminal 4c can be used as the wiring for the electric circuit, and therefore the wiring pattern on the substrate 3 can be reduced, so that the power conversion device 1 can be made smaller.

[0053] When the power conversion device 1 has multiple boards 3, the connection terminal 4c is mechanically connected to the multiple boards 3, and the portion of the connection terminal 4c is wiring for an electric circuit, the multiple boards 3 can be arranged in an area of ​​low-height electric components around the tall electric components without placing a board on top of the tall electric components. Since the multiple boards 3 are placed around the tall electric components, it is possible to eliminate wasted space around the tall electric components, and thus the power conversion device 1 can be made smaller. In addition, since connectors and harnesses for connecting the boards to connect the multiple boards 3 are no longer necessary, the power conversion device 1 can be made smaller and less expensive.

[0054] When the multiple substrates 3 are arranged so that at least a portion of them overlap when viewed in a direction perpendicular to the second surfaces 2b of the multiple power modules 2, the area occupied by the substrates 3 in the power conversion device 1 can be reduced when viewed in a direction perpendicular to the second surfaces 2b of the multiple power modules 2, thereby making the power conversion device 1 more compact.

[0055] When an additional board holding member 11 is provided in a portion between the overlapping multiple boards 3 and the additional board holding member 11 holds at least one board 3, it is possible to improve the insulation between the overlapping multiple boards 3. Since the at least one board 3 is held by the additional board holding member 11 in addition to the connection terminal 4c of the board holding member 4, it is possible to further improve the vibration resistance of the at least one board 3 and the components mounted on the board 3.

[0056] When the board holding member 4 is provided at least partially between the drive circuit board 3b and the busbar 7 and AC busbar 8a, the board holding member 4 having insulation properties is provided between the high voltage portions of the busbar 7 and AC busbar 8a and the drive circuit board 3b, so that insulation between the portions of the busbar 7 and AC busbar 8a and the drive circuit board 3b can be ensured by the board holding member 4. Since insulation between the portions of the busbar 7 and AC busbar 8a and the drive circuit board 3b is ensured, the distance between the portions of the busbar 7 and AC busbar 8a and the drive circuit board 3b can be shortened. Since the distance between the portions of the busbar 7 and AC busbar 8a and the drive circuit board 3b can be shortened, the power conversion device 1 can be made smaller.

[0057] When the portion of the mounted components facing the board holding member and the board holding member are bonded via adhesive 3f, the mounted components are fixed to the board holding member, which further ensures vibration resistance of the board 3 and the mounted components mounted on the board 3. Since the vibration resistance of the board 3 and the mounted components mounted on the board 3 is further ensured, the power conversion device 1 disclosed in the present application can be used in a power conversion device that is rigidly connected to an automobile motor, which has strict vibration resistance requirements.

[0058] When the fixed boss 4b of the board holding member 4 and the housing 6 are made of metal, and the plate 4d, the fixed boss 4b, and the ground of the board 3 are electrically connected, the plate 4d, the fixed boss 4b, and the ground of the board 3 become the same as the ground, which is the potential of the housing 6, so that the necessary ground pattern can be easily provided for the transformer 3c connected to the drive circuit of the board 3. In addition, since the plate 4d is provided between the semiconductor chip 10 of the power module 2 and the board 3 and is connected to the ground, the plate 4d can function as a noise shield that blocks noise generated when the semiconductor chip 10 is switched. Since the plate 4d functions as a noise shield, there is no need to add a new noise shield, so the productivity of the power conversion device 1 can be improved. In addition, since the Young's modulus of the plate 4d is higher than that of the resin material of the board holding member 4, the rigidity of the board holding member 4 can be improved. In addition, since the rigidity of the board holding member 4 is improved, the vibration resistance of the board 3 fixed to the board holding member 4 and the electrical components mounted on the board 3 can be improved.

[0059] When the housing 6 is rigidly connected to at least one of the vibration sources 13 in the vehicle 12, namely the engine, transmission, motor, and e-axle, the vibration resistance of the power conversion device 1 can be ensured even if the housing 6 of the power conversion device 1 is rigidly connected to the vibration source 13 of the vehicle 12, which has strict vibration resistance requirements.

[0060] Although the present application describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless modifications not exemplified are assumed within the scope of the technology disclosed in the present specification, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component and combining it with a component of another embodiment.

[0061] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) a plurality of rectangular parallelepiped power modules each having a semiconductor chip and arranged side by side, the power modules each having a first surface, a second surface opposite to the first surface, and four surfaces surrounding the first surface and the second surface, the third surface, a fourth surface, a fifth surface, and a sixth surface; a substrate disposed on the second surface of the plurality of power modules at intervals and electrically connected to a module terminal of each of the plurality of power modules; a substrate holding member that is disposed in the space between the substrate and the plurality of power modules, holds the substrate, and is made of an insulating resin member; The plurality of power modules are arranged in a direction parallel to the third surface, the module terminal protrudes from at least one of the second surface of the power module, the third surface of the power module, and the fourth surface opposite to the third surface, and then extends toward the substrate; A power conversion device in which the portion of the module terminal extending toward the board passes through a through hole of the board holding member. (Appendix 2) a cooler having a cooling surface thermally connected to the first surfaces of the plurality of power modules; a housing having the cooler and having an arrangement surface on the same side as the cooling surface; a film capacitor electrically connected to the plurality of power modules via a bus bar, adjacent to the plurality of power modules, and thermally connected to the arrangement surface of the housing, the placement surface has a boss fixing portion to which a fixing boss of the board holding member is fixed, 2. The power conversion device according to claim 1, wherein the boss fixing portion is provided on a portion of the arrangement surface excluding the cooling surface and a projected portion of the arrangement surface on which the film capacitor and the bus bar are projected onto the arrangement surface. (Appendix 3) 3. The power conversion device according to claim 1, wherein the through hole is funnel-shaped with an opening on a side of the plurality of power modules being larger than an opening on a side of the substrate. (Appendix 4) the substrate holding member has a connection terminal mechanically connected to the substrate, the connection terminal has an embedded portion embedded in the board holding member and an extending portion extending toward the board and connected to the board, 4. The power conversion device according to claim 1, wherein the substrate is held by the substrate holding member by the connection terminal. (Appendix 5) 5. The power conversion device according to claim 4, wherein the connection terminal is a wiring for an electric circuit. (Appendix 6) A plurality of the substrates are provided, the connection terminals are mechanically connected to the plurality of substrates; 5. The power conversion device according to claim 4, wherein the connection terminal is a wiring for an electric circuit. (Appendix 7) 7. The power conversion device according to claim 6, wherein the plurality of substrates are arranged to overlap at least partially when viewed in a direction perpendicular to the second surfaces of the plurality of power modules. (Appendix 8) an additional substrate holding member is provided between the overlapping substrates; 8. The power conversion apparatus of claim 7, wherein the additional substrate holding member holds at least one of the substrates. (Appendix 9) an AC terminal having an AC bus bar and electrically connected to the plurality of power modules via the AC bus bar; The power conversion device according to any one of appendixes 2 to 8, wherein the substrate holding member is provided at least partially between the substrate and the bus bar and between the substrate and the AC bus bar. (Appendix 10) At least one of a transformer, an aluminum electrolytic capacitor, and a backup transformer is mounted on the board and is electrically connected to the power module; 10. The power conversion device according to claim 1, wherein a portion of the mounted components facing the board holding member and the board holding member are bonded to each other via an adhesive. (Appendix 11) the substrate holding member has a metal plate therein, the fixing boss of the substrate holding member and the housing are made of metal, 11. The power conversion device according to any one of claims 2 to 10, wherein the plate, the fixing boss, and the ground of the substrate are electrically connected to each other. (Appendix 12) The power conversion device according to any one of appendixes 2, 9, and 11, wherein the housing is rigidly connected to at least one of an engine, a transmission, a motor, and an e-axle, which are vibration generating sources in a vehicle. [Explanation of symbols]

[0062] 1 power conversion device, 2 power module, 2a first surface, 2b second surface, 2c third surface, 2d fourth surface, 2e fifth surface, 2f sixth surface, 2g module terminal, 2h power terminal, 3 board, 3a control circuit board, 3b drive circuit board, 3c transformer, 3d aluminum electrolytic capacitor, 3e backup transformer, 3f adhesive, 3g through hole, 3h fixing portion, 3i fixing auxiliary portion, 4 board holding member, 4a through hole, 4b fixing boss, 4c connection terminal, 4c1 buried portion, 4c2 extension portion, 4d plate, 4e board fixing portion, 4f connection wiring, 5 film capacitor, 6 housing, 6a arrangement surface, 6b boss fixing portion, 7 bus bar, 8 AC terminal, 8a AC bus bar, 9 cooler, 9a cooling surface, 9b flow path portion, 9c cover portion, 10 semiconductor chip, 11 Additional board holding member, 11a board fixing portion, 11b recess, 11c fixing boss, 12 vehicle, 13 vibration source

Claims

1. a plurality of rectangular parallelepiped power modules each having a semiconductor chip and arranged side by side, the power modules each having a first surface, a second surface opposite to the first surface, and four surfaces surrounding the first surface and the second surface, the third surface, a fourth surface, a fifth surface, and a sixth surface; a substrate disposed on the second surface of the plurality of power modules at intervals and electrically connected to a module terminal of each of the plurality of power modules; a substrate holding member that is disposed in the space between the substrate and the plurality of power modules, holds the substrate, and is made of an insulating resin member; The plurality of power modules are arranged in a direction parallel to the third surface, the module terminal protrudes from at least one of the second surface of the power module, the third surface of the power module, and the fourth surface opposite to the third surface, and then extends toward the substrate; A power conversion device in which the portion of the module terminal extending toward the board passes through a through hole of the board holding member.

2. a cooler having a cooling surface thermally connected to the first surfaces of the plurality of power modules; a housing having the cooler and having an arrangement surface on the same side as the cooling surface; a film capacitor electrically connected to the plurality of power modules via a bus bar, adjacent to the plurality of power modules, and thermally connected to the arrangement surface of the housing, the placement surface has a boss fixing portion to which a fixing boss of the board holding member is fixed, The power conversion device according to claim 1 , wherein the boss fixing portion is provided on a portion of the arrangement surface excluding the cooling surface and a projected portion of the arrangement surface on which the film capacitor and the bus bar are projected onto the arrangement surface.

3. 3 . The power conversion device according to claim 1 , wherein the through hole is funnel-shaped with an opening on the side of the plurality of power modules being larger than an opening on the side of the substrate.

4. the substrate holding member has a connection terminal mechanically connected to the substrate, the connection terminal has an embedded portion embedded in the board holding member and an extending portion extending toward the board and connected to the board, The power conversion device according to claim 1 or 2, wherein the board is held by the board holding member through the connection terminals.

5. The power conversion device according to claim 4 , wherein the connection terminal portion is a wiring for an electric circuit.

6. A plurality of the substrates are provided, the connection terminals are mechanically connected to the plurality of substrates; The power conversion device according to claim 4 , wherein the connection terminal portion is a wiring for an electric circuit.

7. The power conversion device according to claim 6 , wherein the plurality of substrates are arranged to overlap at least partially when viewed in a direction perpendicular to the second surfaces of the plurality of power modules.

8. an additional substrate holding member is provided between the overlapping substrates; The power conversion apparatus according to claim 7 , wherein the additional substrate holding member holds at least one of the substrates.

9. an AC terminal having an AC bus bar and electrically connected to the plurality of power modules via the AC bus bar; The power conversion device according to claim 2 , wherein the board holding member is provided at least partially between the board and the bus bar and between the board and the AC bus bar.

10. At least one of a transformer, an aluminum electrolytic capacitor, and a backup transformer is mounted on the board and is electrically connected to the power module; 3. The power converter according to claim 1, wherein a portion of the mounted components facing the board holding member and the board holding member are bonded to each other with an adhesive.

11. the substrate holding member has a metal plate therein, the fixing boss of the substrate holding member and the housing are made of metal, The power conversion device according to claim 2 , wherein the plate, the fixing boss, and the ground of the substrate are electrically connected to each other.

12. The power conversion device according to any one of claims 2, 9 and 11, wherein the housing is rigidly connected to at least one of an engine, a transmission, a motor and an e-axle, which are vibration generating sources in a vehicle.

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