Power converter

Abstract

To provide a power conversion device to improve cooling performance by cooling both sides of a power module and suppress warps that occur when a sealing resin is cured at room temperature.SOLUTION: A power conversion device (100) includes: a plurality of power modules (201) that convert DC power to AC power; a DC wiring (22) that transmits DC power to the plurality of power modules (201); a circuit board (30) on which the plurality of power modules (201) are arranged and the DC wiring (22) is mounted; and a mold resin (23) that covers and seals the plurality of power modules (201) and the circuit board (30). The mold resin (23) has sealing surface portions (231, 232) around the plurality of power modules (201) and the thicknesses of the sealing surface portions (231, 232) are thinner than the thickness of a region sealing the plurality of power modules (201).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a power conversion device, and more particularly to a power conversion device that supplies an alternating current to a drive motor of a hybrid vehicle or an electric vehicle.

Background Art

[0002] In recent years, in power conversion devices, while an increase in output is required, an improvement in manufacturability is also demanded. When the power module of a power conversion device has one upper arm circuit or one lower arm circuit for one phase as one module and three phases are provided, six modules need to be provided. Therefore, improving the manufacturability of power modules becomes important.

[0003] On the other hand, improving cooling performance along with improving manufacturability is also an important issue. When the cooling performance is low, it will hinder the increase in the output of the power conversion device. In-vehicle power conversion devices are used in an environment with large temperature changes compared to industrial applications. Therefore, a power conversion device that can maintain high reliability while being placed in a high-temperature environment is required.

[0004] The power conversion device described in Patent Document 1 includes a metal base, an insulating substrate disposed in a region excluding the peripheral portion on the upper surface of the metal base, a semiconductor element mounted on the upper surface of the insulating substrate, a resin case adhered to the peripheral portion on the upper surface of the metal base by an adhesive and surrounding the side surface of the semiconductor element, and a sealing resin filled in the resin case to seal the semiconductor element. A groove portion for filling an adhesive is formed in the peripheral portion on the upper surface of the metal base. According to such a configuration, even when the thickness of the resin case is thin, leakage of the sealing resin and occurrence of insulation failure can be suppressed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] In the power module (semiconductor device) described in Patent Document 1, the sealing resin that encases the semiconductor element is covered by a metal base and a resin case, and the rigidity of these components suppresses warping that occurs when the sealing resin hardens at room temperature. However, this structure employs single-sided cooling, using the bottom surface of the power module as the cooling surface, which results in lower cooling performance compared to double-sided cooling, which cools both the top and bottom surfaces of the power module.

[0007] The objective of the present invention is to improve cooling performance by cooling both sides of the power module and to suppress warping that occurs during room-temperature curing of the sealing resin. [Means for solving the problem]

[0008] This invention First The power conversion device according to this embodiment comprises: a plurality of power modules that convert DC power to AC power; DC wiring that transmits DC power to the plurality of power modules; a circuit board on which the plurality of power modules are arranged and the DC wiring is mounted; and a molded resin that covers and seals the plurality of power modules and the circuit board, wherein the molded resin has a sealing surface around the plurality of power modules, and the thickness of the sealing surface is thinner than the thickness of the area that seals the plurality of power modules. The circuit board is provided with a flow channel forming body above and below it, which forms a flow channel between itself and the circuit board, and the upper and lower parts of each of the multiple power modules are cooled by a refrigerant, and the peripheral edge of the sealing surface part has a flow channel forming body clamping part which holds the flow channel forming body in place. A power conversion device according to a second aspect of the present invention comprises: a plurality of power modules that convert DC power to AC power; DC wiring that transmits DC power to the plurality of power modules; a circuit board on which the plurality of power modules are arranged and the DC wiring is mounted; and a molded resin that covers and seals the plurality of power modules and the circuit board, wherein the molded resin has a sealing surface around the plurality of power modules, the thickness of the sealing surface is thinner than the thickness of the area that seals the plurality of power modules, the sealing surface of the molded resin is a glossy surface, and the surface of the molded resin other than the sealing surface is a matte surface. A power conversion device according to a third aspect of the present invention comprises: a plurality of power modules that convert DC power to AC power; DC wiring that transmits DC power to the plurality of power modules; a circuit board on which the plurality of power modules are arranged and the DC wiring is mounted; and a molded resin that covers and seals the plurality of power modules and the circuit board, wherein the molded resin has a sealing surface around the plurality of power modules, the thickness of the sealing surface is thinner than the thickness of the area that seals the plurality of power modules, the plurality of power modules have three phases of one-phase circuits, each consisting of a first power module constituting an upper arm circuit and a second power module constituting a lower arm circuit, the plurality of power modules are arranged in parallel when viewed from the direction in which the DC wiring extends, and the sealing surface protrudes from the circuit board on both sides in the direction in which the plurality of power modules are arranged in parallel. [Effects of the Invention]

[0009] According to the power conversion device of the present invention, cooling performance can be improved by cooling both sides of the power module, and warping that occurs when the sealing resin is cured at room temperature can be suppressed. [Brief explanation of the drawing]

[0010] [Figure 1]This is a schematic plan view showing a power conversion device according to a first embodiment of the present invention, in which the flow path forming body is omitted. [Figure 2] This is a schematic cross-sectional view of a power conversion device according to the first embodiment of the present invention, taken from line AA in Figure 1. [Figure 3] This is a schematic plan view showing a power conversion device according to a first embodiment of the present invention, in which the mold resin is omitted. [Figure 4] This is a schematic top view showing a first power module according to a first embodiment of the present invention. [Figure 5] This is a schematic perspective view showing a first power module according to a first embodiment of the present invention. [Figure 6] This is a schematic cross-sectional view showing a first power module according to a first embodiment of the present invention. [Figure 7] This is a schematic top view showing a second power module according to the first embodiment of the present invention. [Figure 8] This is a schematic perspective view showing a second power module according to the first embodiment of the present invention. [Figure 9] This is a schematic cross-sectional view showing a second power module according to the first embodiment of the present invention. [Figure 10] This is a schematic plan view showing a power conversion device according to a second embodiment of the present invention, in which the flow path forming body is omitted. [Figure 11] This is a schematic cross-sectional view of a power conversion device according to the third embodiment of the present invention, taken from line AA in Figure 1. [Figure 12] This is a schematic cross-sectional view of a power conversion device according to the fourth embodiment of the present invention, taken from line AA in Figure 1. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not construed as being limited to the following embodiments, and the technical idea of the present invention may be realized by combining other known components. In each figure, the same reference numerals are used for the same elements, and duplicate explanations are omitted. Also, in each figure, the U direction is the upward direction, the D direction is the downward direction, the F direction is the front direction, the B direction is the rear direction, the R direction is the right direction, and the L direction is the left direction.

[0012] <First Embodiment> FIG. 1 is a schematic plan view showing a power conversion device 100 according to this embodiment. In FIG. 1, the illustration of the flow path forming body 25 (see FIG. 2) is omitted. FIG. 2 is a schematic cross-sectional view showing the power conversion device 100 according to this embodiment taken along the line A-A in FIG. 1. FIG. 3 is a schematic plan view showing the power conversion device 100 according to this embodiment. In FIG. 3, the illustration of the mold resin 23 (see FIG. 2) is omitted.

[0013] The power conversion device 100 converts DC power from a battery or the like into AC power to supply to an electric motor. The power conversion device 100 includes upper arm circuits and lower arm circuits for three phases. The power conversion device 100 has circuits for three phases each constituted by a first power module 201 constituting the upper arm circuit and a second power module 202 constituting the lower arm circuit.

[0014] The power conversion device 100 includes a DC wiring 22 that transmits DC power to the first power module 201 and the second power module 202, an AC output terminal conductor 33, a capacitor 40 that smoothes the voltage applied to the power conversion device 100, a control circuit 50 that transmits control signals, and a circuit board 30 such as a printed circuit board on which all of these are mounted.

[0015] The power converter 100 seals the first power module 201 and the second power module 202 and the circuit board 30 by covering them with molding resin 23. In other words, the molding resin 23 seals the first power module 201 and the second power module 202 and the circuit board 30 by covering the circuit board 30 from above and below. This eliminates the need for complexly shaped busbars, improving productivity.

[0016] All six first power modules 201 and the second power modules 202 are arranged in parallel when viewed from the direction extending to the left (L) and right (R) of the DC wiring 22 in Figure 3.

[0017] The DC wiring 22 has a positive power terminal conductor 31 through which current flows into a one-phase circuit composed of the first power module 201 and the second power module 202, and a negative power terminal conductor 32 through which current flows out of a one-phase circuit composed of the first power module 201 and the second power module 202. The positive power terminal conductor 31 and the negative power terminal conductor 32 are stacked from the upper direction U to the lower direction D.

[0018] The first power module 201 is connected to a positive power terminal conductor 31 having a positive power terminal 311 and an AC output terminal conductor 33 having an AC output terminal 331. On the other hand, the second power module 202 is connected to a negative power terminal conductor 32 having a negative power terminal 321 and an AC output terminal conductor 33.

[0019] As a result, the electrical energy required to drive the electric motor from the battery is supplied to the first power module 201 and the second power module 202, which control the AC power output from the AC output terminal 331 provided on the AC output terminal conductor 33. The first power module 201 and the second power module 202 form a single-phase circuit, and three such sets are mounted on the circuit board 30. This eliminates the need for complexly shaped busbars, improving productivity.

[0020] The circuit board 30 comprises multiple conductor layers made of copper or the like, with other parts made of insulating material such as glass epoxy resin. When the conductor layers of the circuit board 30 are configured in a four-layer structure, the positive power terminal conductor 31, on which the positive power terminal 311 is provided, has the top surface of the circuit board 30 and the third inner layer as its main current path, and is connected to the first power module 201 connected to the top surface of the circuit board 30.

[0021] On the other hand, the negative power terminal conductor 32, on which the negative power terminal 321 is provided, has the second inner layer and bottom surface of the circuit board 30 as its main current path. However, near the connection point with the second power module 202 connected to the top surface of the circuit board 30, it is connected to the second power module 202 via via 301.

[0022] In this manner, the laminated structure of the positive power terminal conductor 31 and the negative power terminal conductor 32 allows the currents flowing through each conductor to face each other, and the inductance can be reduced by the magnetic flux cancellation effect.

[0023] The AC output terminal conductor 33 is formed in each layer via vias (not shown) and has AC output terminals 331 that output AC power to the motor. This increases the cross-sectional area of ​​the conductor and reduces the inductance.

[0024] A capacitor 40 having a positive terminal 401 and a negative terminal 402 is mounted on the DC wiring 22 outside the flow path forming body 25. The positive terminal 401 and the negative terminal 402 are arranged in parallel when viewed from the first power module 201 and the second power module 202. The capacitor 40 is made of a film capacitor or the like and is mounted between the first power module 201 and the second power module 202 and the positive power supply terminal 311 and the negative power supply terminal 321.

[0025] This makes the current path from capacitor 40 to the first power module 201 and the current path from the second power module 202 to capacitor 40 uniform, thereby reducing inductance.

[0026] The control circuit 50 is connected to a control signal generation circuit (not shown), and is connected to the first power module 201 and the second power module 202 via control signal wiring 51 such as wire bonding and in-board control signal wiring 52, and is arranged adjacent to each other.

[0027] This reduces the inductance of the control signal wiring 51, preventing a decrease in element driving performance and thus preventing an increase in losses.

[0028] The first power module 201 and the second power module 202 are incorporated into power module mounting holes 302 within the circuit board 30 and sealed with molded resin 23.

[0029] The power converter 100 is equipped with flow path forming bodies 25 above and below the circuit board 30, which form flow paths between the circuit board 30 and the flow path forming bodies 25, and cools the top and bottom of the first power module 201 and the second power module 202 with a coolant.

[0030] The first power module 201 and the second power module 202 have a first heat dissipation surface 233 on their upper surfaces and a second heat dissipation surface 234 on their lower surfaces. The first heat dissipation surface 233 is the surface in contact with the refrigerant and is composed of a molded resin 23 and the upper surface of a conductive plate. The second heat dissipation surface 234 is the surface in contact with the refrigerant and is composed of a molded resin 23 and the lower surface of a conductive plate. Heat dissipation fins 24 are arranged on the first heat dissipation surface 233 and the second heat dissipation surface 234. The upper flow channel forming body 25 is positioned to cover the first heat dissipation surface 233. The lower flow channel forming body 25 is positioned to cover the second heat dissipation surface 234.

[0031] <First Power Module 201> Figure 4 is a schematic top view showing the first power module 201 according to this embodiment. Figure 5 is a schematic perspective view showing the first power module 201 according to this embodiment. Figure 6 is a schematic cross-sectional view showing the first power module 201 according to this embodiment.

[0032] The first power module 201 constitutes a one-phase upper arm circuit in a power converter 100 that converts DC power to AC power. The first power module 201 consists of an IGBT 10, a diode 11, a first collector conductor plate 211 located below the IGBT 10 and the diode 11, and a first emitter conductor plate 221 located above the IGBT 10 and the diode 11.

[0033] The first collector conductor plate 211 and the first emitter conductor plate 221 are provided with one or fewer bent portions 230. The first collector conductor plate 211 and the first emitter conductor plate 221 are connected to the DC wiring 22 on the upper part of the circuit board 30. More specifically, the first collector conductor plate 211 extends linearly without any bends from the portion of the first collector conductor plate 211 that protrudes onto the upper part of the circuit board 30 and is connected to the DC wiring 22 on the upper part of the circuit board 30. The first emitter conductor plate 221 extends to the left L from the portion of the first emitter conductor plate 221 that protrudes onto the upper part of the circuit board 30, and then bends downward D via one bent portion 230 and is connected to the DC wiring 22 on the upper part of the circuit board 30.

[0034] The IGBT 10 is plate-shaped and has a main electrode 101 and a control electrode 102 that controls the main current flowing through the main electrode 101. The IGBT 10 and the diode 11 are sandwiched on both sides by a first collector conductor plate 211 and a first emitter conductor plate 221, respectively. The IGBT 10 and the diode 11 are connected to the first collector conductor plate 211 and the first emitter conductor plate 221 via a metal bonding material 12 such as solder. The first collector conductor plate 211 and the first emitter conductor plate 221 are made of copper.

[0035] <Second Power Module 202> Figure 7 is a schematic top view showing the second power module 202 according to this embodiment. Figure 8 is a schematic perspective view showing the second power module 202 according to this embodiment. Figure 9 is a schematic cross-sectional view showing the second power module 202 according to this embodiment.

[0036] The second power module 202 constitutes a single-phase lower arm circuit in the power converter 100 that converts DC power to AC power. The second power module 202 consists of an IGBT 10, a diode 11, a second collector conductor plate 212 located below the IGBT 10 and the diode 11, and a second emitter conductor plate 222 located above the IGBT 10 and the diode 11.

[0037] The second collector conductor plate 212 and the second emitter conductor plate 222 are provided with one or fewer bends 230. The second collector conductor plate 212 and the second emitter conductor plate 222 are connected to the DC wiring 22 on the upper part of the circuit board 30. More specifically, the second collector conductor plate 212 extends linearly without any bends from the portion of the second collector conductor plate 212 that protrudes onto the upper part of the circuit board 30 and is connected to the DC wiring 22 on the upper part of the circuit board 30. The second emitter conductor plate 222 extends in the rear direction B from the portion of the second emitter conductor plate 222 that protrudes onto the upper part of the circuit board 30, and then bends downward D via one bend 230 and is connected to the DC wiring 22 on the upper part of the circuit board 30.

[0038] The IGBT 10 and diode 11 are sandwiched on both sides by the second collector conductor plate 212 and the second emitter conductor plate 222, respectively. The IGBT 10 and diode 11 are connected to the second collector conductor plate 212 and the second emitter conductor plate 222 via a metal bonding material 12 such as solder. The second collector conductor plate 212 and the second emitter conductor plate 222 are made of copper. The second emitter conductor plate 222 extends horizontally from a portion of the second emitter conductor plate 222 that protrudes from the upper part of the circuit board 30, and then bent downward D through a single bend to connect to the DC wiring 22 on the upper part of the circuit board 30.

[0039] <Features of Mold Resin 23> Returning to Figures 1 to 3, the molded resin 23 has a first sealing surface portion 231 formed on the upper side of the circuit board 30 to surround all three first power modules 201 and three second power modules 202, and a second sealing surface portion 232 formed on the lower side of the circuit board 30 to surround all three first power modules 201 and three second power modules 202.

[0040] The sealing surface of the upper flow path forming body 25 abuts against the first sealing surface portion 231 formed around the multiple power modules 201 and 202. The sealing surface of the lower flow path forming body 25 abuts against the second sealing surface portion 232 formed around the multiple power modules 201 and 202. A sealing groove is formed in the sealing surface portion of the upper flow path forming body 25, and an O-ring 26, which is a sealing member that seals the space between the upper flow path forming body 25 and the first sealing surface portion 231, is placed in this sealing groove. Similarly, a sealing groove is formed in the sealing surface portion of the lower flow path forming body 25, and an O-ring 26, which is a sealing member that seals the space between the lower flow path forming body 25 and the second sealing surface portion 232, is placed in this sealing groove.

[0041] The thickness of the first sealing surface portion 231 and the second sealing surface portion 232 of the molded resin is thinner than the thickness of the area of ​​the molded resin 23 that seals the first power module 201 and the second power module 202. Furthermore, the thickness of the first sealing surface portion 231 is thinner than the area in the molded resin 23 where the first heat dissipation surface 233 is formed. The thickness of the second sealing surface portion 232 is approximately equal to the thickness of the area in the molded resin 23 where the second heat dissipation surface 234 is formed.

[0042] The first sealing surface portion 231 is formed on the upper part of the circuit board 30. The second sealing surface portion 232 is formed on the opposite side of the circuit board 30 from the first sealing surface portion 231. The thickness H1 of the first sealing surface portion 231 and the thickness H2 of the second sealing surface portion 232 are formed to be the same thickness (H1=H2) relative to the circuit board 30.

[0043] The first sealing surface portion 231 and the second sealing surface portion 232 are formed in the same shape, overlapping with the circuit board 30 in the thickness direction. Therefore, since the first sealing surface portion 231 and the second sealing surface portion 232 have the same thickness with respect to the circuit board 30, the first sealing surface portion 231 and the second sealing surface portion 232 are formed with the same volume.

[0044] The first sealing surface portion 231 and the second sealing surface portion 232 protrude from the circuit board 30 on both sides (left direction L and right direction R in Figure 1) of the direction in which all six first power modules 201 and second power modules 202 are arranged in parallel.

[0045] This makes it possible to make the volume of the molded resin 23 uniform in the first sealing surface portion 231 and the second sealing surface portion 232 at the periphery of the molded resin 23 where the first power module 201 and the second power module 202 are not placed. As a result, the amount of shrinkage of the molded resin 23 during room temperature curing is made uniform, and warping is suppressed. Consequently, the polishing process of the first sealing surface portion 231 and the second sealing surface portion 232 is reduced, improving manufacturability.

[0046] The first sealing surface portion 231 and the second sealing surface portion 232 have a channel forming body clamping portion 235 at their peripheral edges. The molded resin 23 is sandwiched between two channel forming bodies 25 so as to surround the first power module 201 and the second power module 202. The control signal wiring 51 is also configured inside the channel forming body 25. Here, the capacitor 40 and the control circuit 50 are not included inside the channel forming body 25.

[0047] Two channel forming bodies 25, each having an O-ring 26, are fastened to the upper and lower parts of the circuit board 30 by clamping components such as screws used in the channel forming body clamping portion 235. This makes it possible to miniaturize the channel forming bodies 25 compared to when the fastening portion is provided on the circuit board 30. Furthermore, it is possible to construct a highly airtight channel that is not affected by the steps caused by the conductor layer of the circuit board 30.

[0048] The first sealing surface portion 231 and the second sealing surface portion 232 of the molded resin 23 are formed with a glossy surface. This increases the adhesion between the first sealing surface portion 231 and the second sealing surface portion 232 and the O-ring 26, thereby improving airtightness.

[0049] The surface of the molded resin 23, excluding the sealing surface, is formed with a textured finish. This makes it easier to remove the molded resin 23 from the molding die during the molding process.

[0050] In the circuit board 30, no conductor layer is placed on the bonding surface with the molded resin 23, and conductors are connected to the peripheral edge of the molded resin 23 via internal wiring. This prevents resin leakage during the formation of the molded resin 23 and improves manufacturability.

[0051] Heat dissipation fins 24 are formed on the upper and lower surfaces of the first power module 201 and the second power module 202. This allows a heat dissipation path to be formed from the semiconductor elements of the first power module 201 and the second power module 202 to the heat dissipation fins 24 without the need for insulating materials. Furthermore, since the heat dissipation fins 24 are directly cooled by a coolant such as oil from the semiconductor elements of the first power module 201 and the second power module 202, an increase in thermal resistance is suppressed, making it possible to increase the output of the power converter.

[0052] Since the capacitor 40 and the control circuit 50 are not contained within the flow path forming body 25, corrosion of electronic components due to contact with the refrigerant can be prevented. On the other hand, the first power module 201 and the second power module 202 and the control signal wiring 51 are configured inside the flow path forming body 25. However, the first power module 201 and the second power module 202 and the control signal wiring 51 are not electrically affected by contact with the refrigerant due to the molding resin 23. The control signal wiring 51 is connected to the control circuit 50 via in-board control signal wiring 52 provided on the circuit board 30.

[0053] <Effects of this embodiment> As described above, in this embodiment, the volume of the molded resin 23 above and below the circuit board 30 is made uniform at the first sealing surface portion 231 and the second sealing surface portion 232 of the periphery of the molded resin 23. This makes the shrinkage amount of the molded resin 23 during room temperature curing uniform and suppresses warping. As a result, the polishing process of the first sealing surface portion 231 and the second sealing surface portion 232 can be reduced, improving the manufacturability of the power converter 100. Furthermore, the first power module 201 and the second power module 202 have heat dissipation fins 24 on their upper and lower surfaces, and the heat dissipation fins 24 are directly cooled from the semiconductor elements of the first power module 201 and the second power module 202 by a coolant such as oil, improving cooling performance.

[0054] <Second Embodiment> In this embodiment, the same reference numerals are used for elements identical to those in the above embodiment, and redundant explanations are omitted.

[0055] Figure 10 is a schematic plan view showing the power converter 100 according to this embodiment. Note that the flow channel forming body 25 is not shown in Figure 10. Between each power module 201 and 202, slits 236 are formed in the first heat dissipation surface 233 and the second heat dissipation surface 234 of the mold resin 23. This enhances the effect of suppressing warping of the mold resin 23 during room temperature curing, and improves the manufacturability of the power converter 100.

[0056] <Third Embodiment> In this embodiment, the same reference numerals are used for elements identical to those in the above embodiment, and redundant explanations are omitted.

[0057] Figure 11 is a schematic cross-sectional view of the power converter 100 according to this embodiment, taken from the line AA in Figure 1. The thickness of the molded resin 23 from the circuit board 30 to the first heat dissipation surface 233 and the second heat dissipation surface 234 is the same. Therefore, in this embodiment, the height of the first collector conductor plate 211 of the first power module 201 is higher than in the first embodiment. This enhances the effect of suppressing warping during room-temperature curing of the molded resin 23, and improves the manufacturability of the power converter 100.

[0058] <Fourth Embodiment> In this embodiment, the same reference numerals are used for elements identical to those in the above embodiment, and redundant explanations are omitted.

[0059] Figure 12 is a schematic cross-sectional view of the power converter 100 according to this embodiment, taken from the line AA in Figure 1. The thickness of the mold resin 23 from the IGBT 10 and diode 11 to the first heat dissipation surface 233 and the second heat dissipation surface 234 is uniformly formed. This enhances the effect of suppressing warping of the mold resin 23 during room temperature curing, improving the manufacturability of the power converter 100.

[0060] <<Effects of the differences>> (A) The power converter 100 includes a first power module 201 and a second power module 202 that convert DC power to AC power. The power converter 100 includes DC wiring 22 that transmits DC power to the first power module 201 and the second power module 202. The power converter 100 includes a circuit board 30 on which the first power module 201 and the second power module 202 are arranged and on which the DC wiring 22 is mounted. The power converter 100 includes a molded resin 23 that covers and seals the first power module 201, the second power module 202 and the circuit board 30. The molded resin 23 has a first sealing surface portion 231 and a second sealing surface portion 232 around the first power module 201 and the second power module 202. The thickness of the first sealing surface portion 231 and the second sealing surface portion 232 is thinner than the thickness of the area that seals the first power module 201 and the second power module 202.

[0061] In this configuration, the volume of the molded resin 23 is made uniform above and below the circuit board 30 at the first sealing surface portion 231 and the second sealing surface portion 232 around the periphery of the molded resin 23 where the first power module 201 and the second power module 202 are not placed. This makes the shrinkage amount of the molded resin 23 during room-temperature curing uniform and suppresses warping. As a result, the polishing process of the first sealing surface portion 231 and the second sealing surface portion 232 is reduced, improving manufacturability. Furthermore, since the circuit board 30 is covered by the molded resin 23 above and below, the first power module 201 and the second power module 202 can be made into a structure that allows for double-sided cooling. Therefore, double-sided cooling of the first power module 201 and the second power module 202 improves cooling performance and suppresses warping that occurs during room-temperature curing of the sealing resin.

[0062] (B) The sealing surfaces 231 and 232 include a first sealing surface 231 formed on the upper part of the circuit board 30, and a second sealing surface 232 formed on the opposite side of the circuit board 30 from the first sealing surface 231. The first sealing surface 231 and the second sealing surface 232 are formed with the same thickness relative to the circuit board 30.

[0063] In this configuration, by making the volume of the mold resin 23 uniform at the first sealing surface portion 231 and the second sealing surface portion 232 at the periphery of the mold resin 23 where the first power module 201 and the second power module 202 are not placed, the amount of shrinkage of the mold resin 23 at the first sealing surface portion 231 and the second sealing surface portion 232 during room temperature curing can be made uniform, thereby suppressing warping.

[0064] (C) Each of the multiple power modules 201 and 202 has three phases of one-phase circuits, each consisting of a first power module 201 that constitutes the upper arm circuit and a second power module 202 that constitutes the lower arm circuit. The multiple power modules 201 and 202 are arranged in parallel when viewed from the direction in which the DC wiring 22 extends.

[0065] In this configuration, six power modules 201 and 202 can be aligned, and the sealing surfaces 231 and 232 of the molded resin 23 can be configured in a simple shape.

[0066] (D) Between each power module 201 and 202, slits 236 are formed in the first heat dissipation surface 233 and the second heat dissipation surface 234 of the molded resin 23.

[0067] In this configuration, six power modules 201 and 202 can be aligned, and a non-contact state can be maintained between each power module 201 and 202.

[0068] The power converter 100 is equipped with flow path forming bodies 25 above and below the circuit board 30, which form flow paths between the circuit board 30 and the flow path forming bodies, and cools the above and below of the multiple power modules 201 and 202 with a coolant.

[0069] In this configuration, since the circuit board 30 covered with molded resin 23 is provided with flow channel forming bodies 25 on both the top and bottom, all power modules 201 and 202 can be cooled on both sides.

[0070] (E) The power converter 100 has a flow path forming body clamping portion 235 that clamps a flow path forming body 25 at the periphery of the sealing surface portions 231 and 232.

[0071] In this configuration, the channel forming body 25 can be made smaller compared to the case where fastening parts for fastening the channel forming body 25 are provided on the circuit board 30.

[0072] (F) The sealing surfaces 231 and 232 of the molded resin 23 are glossy surfaces. The surfaces of the molded resin 23 other than the sealing surfaces 231 and 232 are matte surfaces.

[0073] In this configuration, the glossy surfaces of the sealing surfaces 231 and 232 increase the adhesion between the first sealing surface 231 and the second sealing surface 232 and sealing members such as the O-ring 26, thereby improving airtightness. The matte surfaces of the surfaces other than the sealing surfaces 231 and 232 make it easier to remove the molded resin 23 from the mold during formation.

[0074] (G) The DC wiring 22 has a positive power terminal conductor 31 through which current flows into a one-phase circuit composed of two power modules 201 and 202, and a negative power terminal conductor 32 through which current flows out of a one-phase circuit composed of two power modules 201 and 202. The positive power terminal conductor 31 and the negative power terminal conductor 32 are stacked.

[0075] In this configuration, the positive power terminal conductor 31 and the negative power terminal conductor 32 have a laminated structure, and the currents flowing through each conductor layer face each other, exhibiting a magnetic flux cancellation effect, thereby reducing the inductance.

[0076] (H) The DC wiring 22 is equipped with a capacitor 40 having a positive terminal 401 and a negative terminal 402 outside the flow path forming body 25. The positive terminal 401 and the negative terminal 402 are arranged in parallel when viewed from multiple power modules 201 and 202.

[0077] In this configuration, the current path flowing from the capacitor 40 to one power module 201 and the current path flowing from the other power module 202 to the capacitor 40 can be made uniform, thereby reducing inductance.

[0078] (I) The mold resin 23 covers and seals the multiple power modules 201, 202 and the circuit board 30 by covering the circuit board 30 from above and below.

[0079] In this configuration, flow channel forming bodies 25 can be positioned above and below the circuit board 30 covered with mold resin 23, improving cooling performance through double-sided cooling of each power module 201 and 202. Furthermore, since the top and bottom of the circuit board 30 are covered with mold resin 23, warping that occurs during the room-temperature curing of the sealing resin can be suppressed.

[0080] (J) The first sealing surface portion 231 and the second sealing surface portion 232 are formed in the same shape so as to overlap with the circuit board 30 in the thickness direction.

[0081] In this configuration, the shape and thickness of the molded resin 23 can be made the same at the first sealing surface portion 231 and the second sealing surface portion 232 at the periphery of the molded resin 23 where the power modules 201 and 202 are not located, thereby making the volume uniform.

[0082] (K) The first sealing surface portion 231 and the second sealing surface portion 232 are formed with the same volume.

[0083] In this configuration, since the first sealing surface portion 231 and the second sealing surface portion 232 have the same volume, the amount of shrinkage of the mold resin 23 of the first sealing surface portion 231 and the second sealing surface portion 232 during room temperature curing can be made uniform, thereby suppressing warping.

[0084] (L) The sealing surfaces 231 and 232 protrude from the circuit board 30 on both sides in the direction in which the multiple power modules 201 and 202 are arranged in parallel.

[0085] In this configuration, the molded resin 23 that protrudes from the circuit board 30 is connected above and below the circuit board 30, allowing the molded resin 23 to be integrated into a single unit.

[0086] (M) Each of the multiple power modules 201 and 202 consists of an IGBT 10, a diode 11, collector conductor plates 211 and 212 positioned below the IGBT 10 and diode 11, and emitter conductor plates 221 and 222 positioned above the IGBT 10 and diode 11. The collector conductor plates 211 and 212 and the emitter conductor plates 221 and 222 are provided with a bend of 1 or less 230. The collector conductor plates 211 and 212 and the emitter conductor plates 221 and 222 are connected to the DC wiring 22 on the upper part of the circuit board 30.

[0087] In this configuration, the number of bent portions 230 in the collector conductor plates 211, 212 and the emitter conductor plates 221, 222 is reduced, improving manufacturability.

[0088] (N) The collector conductor plates 211 and 212 extend in a straight line without any bends from the portion of the collector conductor plates 211 and 212 that protrudes from the upper part of the circuit board 30 and are connected to the DC wiring 22 on the upper part of the circuit board 30.

[0089] In this configuration, there are no bends in the collector conductor plates 211 and 212, improving manufacturability. [Explanation of Symbols]

[0090] 10…IGBT, 11…Diode, 12…Metal bonding material, 22…DC wiring, 23…Molding resin, 24…Heat sink fin, 25…Flow channel forming body, 26…O-ring, 30…Circuit board, 31…Positive power terminal conductor, 32…Negative power terminal conductor, 33…AC output terminal conductor, 40…Capacitor, 50…Control circuit, 51…Control signal wiring, 52…In-board control signal wiring, 100…Power converter, 101…Main electrode, 102…Control electrode, 201…First power module, 202…Second power module Joule, 211...First collector conductor plate, 212...Second collector conductor plate, 221...First emitter conductor plate, 222...Second emitter conductor plate, 230...Bend, 231...First sealing surface, 232...Second sealing surface, 233...First heat dissipation surface, 234...Second heat dissipation surface, 235...Flow channel forming body clamping part, 236...Slit, 301...Via, 302...Power module mounting hole, 311...Positive power terminal, 321...Negative power terminal, 331...AC output terminal, 401...Positive terminal, 402...Negative terminal.

Claims

1. Multiple power modules that convert DC power to AC power, DC wiring for transmitting DC power to multiple power modules, A circuit board on which multiple power modules are arranged and the DC wiring is mounted, A molded resin that covers and seals multiple power modules and the circuit board, Equipped with, The molded resin has sealing surfaces around the multiple power modules. The thickness of the sealing surface is thinner than the thickness of the area that seals the multiple power modules. The circuit board is provided with a channel forming body above and below it, which forms a channel between itself and the circuit board, and the upper and lower parts of each of the multiple power modules are cooled by a coolant. The sealing surface portion has a channel forming body clamping portion that holds the channel forming body in place at its peripheral edge. Power converter.

2. A plurality of power modules that convert DC power to AC power, DC wiring for transmitting DC power to multiple power modules, A circuit board on which multiple power modules are arranged and the DC wiring is mounted, A molded resin that covers and seals multiple power modules and the circuit board, Equipped with, The molded resin has sealing surfaces around the multiple power modules. The thickness of the sealing surface is thinner than the thickness of the area that seals the multiple power modules. The sealing surface portion of the mold resin is a glossy surface. The surface of the mold resin other than the sealing surface is a textured surface. Power converter.

3. Multiple power modules that convert DC power to AC power, DC wiring for transmitting DC power to multiple power modules, A circuit board on which multiple power modules are arranged and the DC wiring is mounted, A molded resin that covers and seals multiple power modules and the circuit board, Equipped with, The molded resin has sealing surfaces around the multiple power modules. The thickness of the sealing surface is thinner than the thickness of the area that seals the multiple power modules. Each of the aforementioned power modules has three phases of one-phase circuits, each consisting of a first power module constituting an upper arm circuit and a second power module constituting a lower arm circuit. The multiple power modules are arranged in parallel when viewed from the direction in which the DC wiring extends. The sealing surface portion protrudes from the circuit board on both sides in the direction in which the multiple power modules are arranged in parallel. Power converter.

4. A power conversion device according to any one of claims 1 to 3, The sealing surface portion includes a first sealing surface portion formed on the upper part of the circuit board and a second sealing surface portion formed on the side opposite to the circuit board from the first sealing surface portion. The first sealing surface and the second sealing surface are formed to the same thickness as the circuit board. Power converter.

5. A power conversion device according to claim 1 or claim 2, Each of the aforementioned power modules has three phases of one-phase circuits, each consisting of a first power module constituting an upper arm circuit and a second power module constituting a lower arm circuit. The multiple power modules are arranged in parallel when viewed from the direction in which the DC wiring extends. Power converter.

6. A power conversion device according to claim 5, Slits are formed in the molded resin between each power module. Power converter.

7. A power conversion device according to claim 2 or claim 3, The circuit board is provided with a channel forming body above and below it, which forms a channel between itself and the circuit board, and the upper and lower parts of each of the multiple power modules are cooled by a refrigerant. Power converter.

8. A power conversion device according to claim 7, The sealing surface portion has a channel forming body clamping portion that holds the channel forming body in place at its peripheral edge. Power converter.

9. A power conversion device according to claim 3, The sealing surface portion of the mold resin is a glossy surface. The surface of the mold resin other than the sealing surface is a textured surface. Power converter.

10. A power conversion device according to any one of claims 1 to 3, The DC wiring has a positive power terminal conductor through which current flows into a one-phase circuit composed of the two power modules, and a negative power terminal conductor through which current flows out of the one-phase circuit composed of the two power modules. The positive power terminal conductor and the negative power terminal conductor are stacked. Power converter.

11. A power conversion device according to claim 7, The DC wiring is equipped with a capacitor having a positive terminal and a negative terminal on the outside of the flow path forming body. The positive and negative terminals are arranged in parallel when viewed from multiple power modules. Power converter.

12. A power conversion device according to any one of claims 1 to 3, The molding resin seals the multiple power modules and the circuit board by covering them from above and below the circuit board. Power converter.

13. A power conversion device according to claim 4, The first sealing surface and the second sealing surface are formed to overlap with the circuit board in the thickness direction and have the same shape. Power converter.

14. A power conversion device according to claim 13, The first sealing surface and the second sealing surface are formed with the same volume. Power converter.

15. A power conversion device according to claim 5, The sealing surface portion protrudes from the circuit board on both sides in the direction in which the multiple power modules are arranged in parallel. Power converter.

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