Power conversion device and manufacturing method thereof

Abstract

The present invention provides a power conversion device that suppresses size increase while also minimizing deterioration in the placement accuracy of components connected to the outside. The device comprises a power module having a semiconductor element, a heat sink thermally connected to the power module on one surface, and a connection circuit portion arranged alongside the power module on one surface of the heat sink, comprising a bus bar electrically connecting the power module to the outside and a metal terminal insulated from the bus bar. The connection circuit portion is thermally and mechanically connected to the one surface of the heat sink at a portion of the metal terminal exposed from the connection circuit portion.

Description

Technical Field

[0001] The present application relates to a power conversion device and a method for manufacturing the same. Background Art

[0002] Electric vehicles, such as electric vehicles and hybrid electric vehicles, that use electric motors as their driving source are equipped with multiple power conversion devices. A power conversion device is a device that converts input current from DC to AC, from AC to DC, or converts input voltage to a different voltage. Specifically, a charger that converts commercial AC power to DC power and charges a high-voltage battery, a DC / DC converter that converts the DC power of a high-voltage battery to the voltage of a battery for auxiliary equipment (e.g., 12V), and an inverter that converts DC power from a battery to AC power for supplying the motor can be listed.

[0003] The power conversion device installed in electric or hybrid vehicles consists of a power module with semiconductor elements; a connection circuit unit that houses a heat sink, busbars, and other components; a control substrate that controls the semiconductor elements; and a housing that supports these components. The power conversion device, consisting of these components, is assembled through the following steps. First, wiring is installed within the power module, and then the interior of the power module is sealed. Next, the power module is secured to the heat sink to form a subassembly. Next, the connection circuit unit is screwed and assembled to the subassembly or housing to secure the connection circuit unit. Next, the connection circuit unit is connected to the power terminals of the power module using TIG welding or screws. Next, the control substrate is connected to the signal terminals of the power module using welding or connectors to secure the control substrate. Finally, a cover covering these components and a control connector for external connections are assembled. In this way, the components connected to the outside are finally secured.

[0004] The manufacturing process of the power conversion device includes a plurality of assembly processes as described above, and each assembly process requires positioning. Therefore, each component is processed for nesting or pressed with a positioning pin, etc. In addition, if there are many components, the number of assembly processes will increase, and the positioning tolerance will increase accordingly as the number of assembly processes increases. Since the components are assembled based on the initially fixed power module, the tolerance will continue to accumulate on the last fixed component connected to the outside of the power conversion device. Therefore, the positional accuracy of the connection between the external device connected to the power conversion device, namely the motor and battery, and the external component of the power conversion device is deteriorated. In order to suppress the deterioration of the positional accuracy, it is necessary to provide a fastening hole larger than the screw diameter to absorb the tolerance, or it is necessary to provide a tolerance absorbing structure such as a flexible busbar and connector (for example, refer to patent document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-42026 Summary of the Invention

[0008] Technical problem to be solved by the invention

[0009] Patent Document 1, described above, utilizes a tolerance absorbing structure using a flexible busbar, thereby suppressing deterioration in the positional accuracy of connections between external equipment connected to the power conversion device and the externally connected components of the power conversion device. However, the provision of the new tolerance absorbing structure increases the number of components in the power conversion device, leading to an increase in the size of the power conversion device.

[0010] Therefore, an object of the present application is to obtain a power conversion device that suppresses increase in size while suppressing deterioration in the accuracy of arrangement of components connected to the outside.

[0011] Technical means for solving technical problems

[0012] The power conversion device disclosed in the present application includes: a power module having a semiconductor element; a heat sink having one surface thermally connected to the power module; and a connection circuit portion arranged side by side with the power module on one surface of the heat sink, comprising a busbar electrically connecting the power module to the outside, and a metal terminal insulated from the busbar, wherein the connection circuit portion is thermally and mechanically connected to one surface of the heat sink at a portion of the metal terminal exposed to the outside from the connection circuit portion.

[0013] The manufacturing method of the power conversion device disclosed in the present application includes: a component preparation step of preparing a power module having a semiconductor element, a heat sink, and a connection circuit part having a busbar and a metal terminal insulated from the busbar; a connection circuit part connection step of thermally and mechanically connecting the connection circuit part to a surface of the heat sink at a portion of the metal terminal of the connection circuit part exposed to the outside from the connection circuit part; and a power module connection step of thermally connecting the power module to a surface of the heat sink by interlocking a power module interlocking part provided on one side of the connection circuit part of the power module with a first interlocking part provided on one side of the connection circuit part of the power module.

[0014] Effects of the Invention

[0015] The power conversion device disclosed herein includes a busbar (a component electrically connecting a power module to the outside) and a metal terminal insulated from the busbar. The connection circuit portion is arranged side by side with the power module on one surface of a heat sink. The portion of the metal terminal exposed from the connection circuit portion is thermally and mechanically connected to the surface of the heat sink. Consequently, the connection circuit portion is positioned and secured to the heat sink via the metal terminal. This prevents any tolerances based on the position of the power module from being accumulated on the busbar of the connection circuit portion, which connects to the outside. This reduces the accuracy of the busbar placement. Furthermore, since no additional tolerance-absorbing structure is required, the size of the power conversion device can be minimized.

[0016] The method for manufacturing a power conversion device disclosed in the present application includes: a component preparation step of preparing a power module, a heat sink, and a connection circuit unit having a busbar (a component for electrically connecting the power module to the outside) and a metal terminal insulated from the busbar; a connection circuit unit connection step of thermally and mechanically connecting the connection circuit unit to one surface of the heat sink via the metal terminal of the connection circuit unit; and a power module connection step of thermally connecting the power module to one surface of the heat sink by engaging a power module mating portion provided on one side of the connection circuit unit with a first mating portion provided on the power module side of the connection circuit unit. Therefore, the connection circuit unit is first positioned and fixed to the heat sink using the metal terminal, and then the power module is positioned on the connection circuit unit. Therefore, tolerances based on the position of the power module are not accumulated on the busbar of the connection circuit unit that connects to the outside, thereby suppressing deterioration in busbar placement accuracy. Furthermore, since no additional tolerance absorbing structure is required, the size of the power conversion device can be suppressed, thereby improving the productivity of the power conversion device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a plan view schematically showing the power conversion device according to the first embodiment.

[0018] Figure 2 is Figure 1 A cross-sectional view of the power conversion device cut at the AA cross-sectional position.

[0019] Figure 3 It is a perspective view showing a main part of a connection circuit unit of the power conversion device according to the first embodiment.

[0020] Figure 4 It is a side view showing a main part of the connection circuit unit of the power conversion device according to the first embodiment.

[0021] Figure 5 It is a perspective view showing a main part of another connection circuit unit of the power conversion device according to the first embodiment.

[0022] Figure 6 This is a side view showing a main part of another connection circuit unit of the power conversion device according to the first embodiment.

[0023] Figure 7 It is a diagram showing a manufacturing process of the power conversion device according to the first embodiment.

[0024] Figure 8 It is a plan view schematically showing a power conversion device according to the second embodiment.

[0025] Figure 9 is Figure 8 A cross-sectional view of the power conversion device cut at the BB cross-section position.

[0026] Figure 10 It is a diagram showing a manufacturing process of the power conversion device according to the second embodiment.

[0027] Figure 11 It is a diagram showing a manufacturing process of a power conversion device according to a comparative example. DETAILED DESCRIPTION

[0028] Hereinafter, a power conversion device and a manufacturing method thereof according to an embodiment of the present application will be described with reference to the accompanying drawings. In the drawings, the same or corresponding components and parts are denoted by the same reference numerals for description.

[0029] Implementation method 1.

[0030] Figure 1 is a schematic plan view showing a power conversion device 100 according to the first embodiment. Figure 2 yes Figure 1 A cross-sectional view of the power conversion device 100 cut at the AA cross-sectional position, Figure 3 1 is a perspective view showing a main part of the connection circuit unit 50 of the power conversion device 100 according to the first embodiment. Figure 4 1 is a side view showing the main part of the connection circuit unit 50 of the power conversion device 100. Figure 5 1 is a perspective view showing a main part of another connection circuit unit 50 a of the power conversion device 100 according to the first embodiment. Figure 6 1 is a side view showing a main part of another connection circuit portion 50a, Figure 7 1 is a diagram showing a manufacturing process of the power conversion device 100 according to the first embodiment. Figure 11 It is a diagram showing a manufacturing process of a power conversion device according to a comparative example. Figure 1It is a plan view showing the control substrate 90 located in the connection circuit unit 50. The power conversion device 100 is a device that converts input current from DC to AC, from AC to DC, or converts input voltage to a different voltage.

[0031] like Figure 2 As shown, the power conversion device 100 includes: a power module 10 having a semiconductor element 11; a heat sink 80 having one surface thermally connected to the power module 10; a connection circuit unit 50 arranged side by side with the power module 10 on one surface of the heat sink 80; a control unit, namely a control substrate 90, arranged on one side of one surface of the heat sink 80 opposite to the power module 10 and the connection circuit unit 50 and controlling the semiconductor element 11; a capacitor module 30 electrically connected to the connection circuit unit 50; and a housing 70 supporting the other side of the heat sink 80. Figure 2 In FIG, the control substrate 90 is shown only by a dotted line. The power conversion device 100 shown in this embodiment is a device that transmits filtered DC power from the outside to the power module 10 via the capacitor module 30, converts power through the power module 10 to send AC power to the AC bus 51, and outputs the AC power to the outside. Figure 1 As shown, the power conversion device 100 includes three power modules 10. The power modules 10 output, for example, three-phase AC power. The power conversion device 100 can also transmit DC power to the outside through a path opposite to the above path.

[0032] Power Module 10

[0033] like Figure 2As shown, power module 10 includes a semiconductor element 11, a semiconductor element wiring member 12, power module wiring members 13a and 13b, a conductive bonding material 14, a molded resin 15, an insulating member 16, a signal terminal 17, and a signal terminal spacing-enforcing resin 18. Power module wiring members 13a and 13b and signal terminal 17 are terminals exposed to the outside of power module 10. Power module 10 generates heat when power is supplied to it. Power module wiring member 13a is electrically and thermally connected to semiconductor element 11 via conductive bonding material 14 on one surface. Power module wiring member 13a is thermally connected to insulating member 16 on the other surface. A portion of power module wiring member 13a extends from molded resin 15 to the outside and is electrically connected to AC busbar 51. Power module wiring member 13b is electrically and thermally connected to one end of semiconductor element wiring member 12 via conductive bonding material 14 on one surface. Power module wiring member 13b is thermally connected to insulating member 16 on the other surface. A portion of the power module wiring member 13b extends from the mold resin 15 to the outside and is electrically connected to the DC bus bar 53. The other end of the semiconductor element wiring member 12 is electrically and thermally connected to the semiconductor element 11 via the conductive bonding material 14.

[0034] The signal terminals 17 are connected to the control substrate 90. The control substrate 90 has a plurality of signal terminal insertion holes 91 for inserting the signal terminals 17. The signal terminal spacing enforcing resin 18 is a resin member disposed around the plurality of signal terminals 17 to ensure uniform spacing between the plurality of signal terminals 17 arranged side by side. The provision of the signal terminal spacing enforcing resin 18 facilitates insertion of the plurality of signal terminals 17 into the signal terminal insertion holes 91. The signal terminal spacing enforcing resin 18 includes a power module mating portion 18a on the side of the connection circuit portion 50. A detailed description of the power module mating portion 18a will be provided later. The components of the semiconductor module 10, such as the semiconductor element 11, are sealed with a molding resin 15. The signal terminal spacing enforcing resin 18 is molded simultaneously with the molding of the power module 10. The surface of the insulating member 16 not connected to the power module wiring members 13a and 13b is thermally connected to one surface of the heat sink 80 via solder 96. The heat sink 80 and its fins 81 are formed of a metal with high thermal conductivity, such as aluminum. The connection between the power module wiring member 13 a and the AC bus bar 51 and the connection between the power module wiring member 13 b and the DC bus bar 53 can be achieved by screw fastening, welding, or the like.

[0035] <Capacitor module 30>

[0036] The capacitor module 30 includes a filter capacitor for filtering direct current. The capacitor module 30 is fixed in a recess of the housing 70 sandwiched between the first flow path portion 82 and the second flow path portion 83 formed in the housing 70. The portion where the capacitor module 30 is fixed is covered by a capacitor cover 94 to prevent water from entering the capacitor module 30 from the outside. The capacitor wiring member 31 extends from the capacitor module 30 to the outside, and the capacitor wiring member 31 is electrically connected to the connection circuit portion 50 (the connection portion is not shown). In addition, the configuration of the capacitor module 30 is not limited to the recess of the housing 70, and the capacitor module 30 can also be configured on one side of one surface of the heat sink 80.

[0037] <Casing 70>

[0038] The housing 70 is a member that supports one side of the other side of the housing 70, on which the power module 10 and the heat sink 80 of the connection circuit unit 50 are arranged. In addition, a flow path for the flow of refrigerant is formed in the housing 70. The refrigerant flows from the first flow path portion 82 to the second flow path portion 83 through the heat sink fins 81. The refrigerant is, for example, water or ethylene glycol liquid. The housing 70 is made of, for example, aluminum by die casting. The heat sink 80 and the heat sink fins 81 are cooled by the refrigerant. The heat sink fins 81 are arranged along the direction of the refrigerant flow from the first flow path portion 82 to the second flow path portion 83. A positioning pin 71 for positioning the connection circuit unit 50 and the heat sink 80 is pressed into the housing 70. A through hole for the positioning pin 71 to pass through is formed in the heat sink 80. A hole portion that interlocks with the positioning pin 71 is formed on the surface of the connection circuit unit 50 opposite to the heat sink 80.

[0039] <Connecting Circuit Section 50>

[0040] The connection circuit unit 50 includes a bus bar that electrically connects the outside to the power module 10 , and a metal terminal 20 insulated from the bus bar. Figure 2 In FIG. 1 , the portion of the connection circuit unit 50 disposed on the left side of the power module 10 includes the AC busbar 51, the current sensor 93, and the metal terminal 20. The portion of the connection circuit unit 50 disposed on the right side of the power module 10 includes the DC busbar 53 and the metal terminal 20. Among the components of the connection circuit unit 50, at least a portion of each component is sealed with a molding resin 52. The connection circuit unit 50 is as shown in FIG. Figure 3 and Figure 4 As shown, there is at least one metal terminal 20 . Figure 3 and Figure 4This figure shows only the surrounding portion of the metal terminal 20 of the connection circuit portion 50, and the surrounding portion of the metal terminal 20 is transparent to show the appearance of the metal terminal 20. The connection circuit portion 50 is thermally and mechanically connected to one surface of the heat sink 80 via solder 96 at the portion of the metal terminal 20 exposed to the outside from the connection circuit portion 50. The connection circuit portion 50 has the metal terminal 20, so that the connection circuit portion 50 can be positioned and fixed to one surface of the heat sink 80 in a thermally and mechanically connected manner. The connection between the AC busbar 51 and the wiring member 13a for the power module, and the connection between the DC busbar 53 and the wiring member 13b for the power module are, for example, welded. In addition, these connections are not limited to welding, and a terminal block can also be provided in the connection circuit portion 50, and electrical connection can be made by tightening screws. The external output connection portion 58 of the AC busbar 51 is connected to, for example, a motor (not shown). The external output connection portion 59 of the DC busbar 53 is connected to, for example, a battery (not shown).

[0041] The metal terminal 20 is a sheet metal member plated with copper or aluminum. The AC busbar 51 is a heat generating component, so the metal terminal 20 disposed around the AC busbar 51 transfers the heat of the AC busbar 51 to the heat sink 80 via the molded resin 52. The structure of the metal terminal 20 is not limited to Figure 3 and Figure 4 The connection circuit portion 50 may include a plurality of metal terminals 20 , and a portion or all of the plurality of metal terminals 20 may be integrated within the connection circuit portion 50 . Figure 5 and Figure 6 This figure shows only the surrounding portion of the metal terminal 20 included in the connection circuit portion 50 a , and shows the appearance of the metal terminal 20 by seeing through the surrounding portion of the metal terminal 20 . Figure 5 and Figure 6 The metal terminals 20 shown in the figure have a terminal connection portion 20a within the connection circuit portion 50a, which integrates the metal terminals 20. The terminal connection portion 20a connects the metal terminals 20 arranged side by side. By integrating multiple metal terminals 20, the rigidity of the connection circuit portion 50a can be improved. The multiple metal terminals 20 arranged around the AC busbar 51 can efficiently transfer heat generated by the AC busbar 51 to the heat sink 80.

[0042] <Positioning Structure of Power Module 10>

[0043] The signal terminal spacing enforcing resin 18 of the power module 10 has a power module fitting portion 18 on the side of the connection circuit portion 50. The connection circuit portion 50 has a first fitting portion 54 on the side of the power module. The power module 10 is positioned relative to the connection circuit portion 50 on one surface of the heat sink 80 by the power module fitting portion 18a and the first fitting portion 54 fitting together. In this embodiment, the first fitting portion 54 is a hole provided on the power module 10 side of the connection circuit portion 50 in a portion opposite to the control substrate 90. In addition, in this embodiment, the power module fitting portion 18a is a protrusion that fits into the hole serving as the first fitting portion 54 on the side of the connection circuit portion 50 of the signal terminal spacing enforcing resin 18. However, the shapes of the power module fitting portion 18a and the first fitting portion 54 are not limited thereto. The power module fitting portion 18a may be a hole, and the first fitting portion 54 may be a protrusion that fits into the hole of the power module fitting portion 18a.

[0044] With this structure, the connection circuit unit 50 is positioned and fixed to the heat sink 80 via the metal terminals 20, and the power module 10 is positioned relative to the connection circuit unit 50. Therefore, tolerances based on the position of the power module 10 are not accumulated on the external output connectors 58 and 59 of the busbars (which are components of the connection circuit unit 50 that connect to the outside). This can suppress degradation in the accuracy of the placement of the external output connectors 58 and 59. Furthermore, since no additional tolerance absorbing structure is required, the size of the power conversion device 100 can be suppressed. Furthermore, no positioning member is required between the power module 10 and the heat sink 80, thereby improving the productivity of the power conversion device 100.

[0045] In addition, taking into account the tolerance accumulated on the external output connection parts 58 and 59 with the shell 70 as a reference, the connection circuit part 50 is also positioned relative to the shell 70 by the positioning pins 71 provided in the shell 70. Therefore, the tolerance accumulated on the external output connection parts 58 and 59 of the busbar provided in the connection circuit part 50 with the position of the shell 70 as a reference will not be accumulated, and the deterioration of the accuracy of the configuration of the external output connection parts 58 and 59 can be suppressed.

[0046] <Positioning Structure of Control Board 90>

[0047] The control substrate 90 has a control portion interlocking portion 92 at a portion opposite to the connection circuit portion 50. The connection circuit portion 50 has a second interlocking portion 55 at a portion opposite to the control substrate 90. The control substrate 90 is positioned relative to the connection circuit portion 50 on one side of the heat sink 80 by the mutual interlocking of the control portion interlocking portion 92 and the second interlocking portion 55. In the present embodiment, the control portion interlocking portion 92 is a hole provided in the portion of the control substrate 90 opposite to the connection circuit portion 50. In addition, in the present embodiment, the second interlocking portion 55 is a protrusion that interlocks with the hole serving as the control portion interlocking portion 92. However, the shapes of the control portion interlocking portion 92 and the second interlocking portion 55 are not limited thereto; the control portion interlocking portion 92 may be a protrusion, and the second interlocking portion 55 may be a hole that interlocks with the protrusion serving as the control portion interlocking portion 92.

[0048] With this structure, the connection circuit unit 50 is positioned and fixed to the heat sink 80 via the metal terminals 20. The power module 10 is positioned relative to the connection circuit unit 50, and the control board 90 is positioned relative to the connection circuit unit 50. Consequently, tolerances based on the position of the power module 10 are not accumulated in the signal terminal insertion holes 91 of the control board 90, thus suppressing degradation in the accuracy of the placement of the signal terminal insertion holes 91. Consequently, the signal terminals 17 of the power module 10 can be easily inserted into the signal terminal insertion holes 91. Furthermore, since no additional tolerance absorbing structure is required, the size of the power conversion device 100 can be suppressed. Furthermore, since the signal terminals 17 or the signal terminal insertion holes 91 do not need to be processed with high precision to facilitate easy insertion of the signal terminals 17, the productivity of the power conversion device 100 can be improved.

[0049] Misalignment in the assembly of the power module 10 and the connection circuit unit 50 and their placement on the heat sink 80 can cause interference between the power module fitting portion 18a and the first fitting portion 54, thereby applying a load to the signal terminals 17. Since the heat sink 80, the power module 10, and the connection circuit unit 50 are secured by soldering, when the solder 96 melts, the load on the signal terminals 17 is relieved by the positioning of the power module 10, thereby eliminating any residual stress on the signal terminals 17. Furthermore, due to the positioning effect created by the melting solder, the signal terminals 17 move to a position where they can easily enter the signal terminal insertion holes 91 of the control board 90 as the power module 10 itself slightly moves.

[0050] <Comparative Example of Method for Manufacturing Power Conversion Device>

[0051] refer to Figure 11A comparative example of a method for manufacturing a power conversion device is described. The method for manufacturing a power conversion device includes: a component preparation step (S111), a power module connection step (S112), a connection circuit portion connection step (S113), a wiring connection step (S114), and a control substrate connection step (S115). The component preparation step is a step of preparing a power module having a semiconductor element, a heat sink, and a connection circuit portion having a busbar. The power module connection step is a step of thermally connecting the power module to one surface of the heat sink by welding. The connection circuit portion connection step is a step of mechanically fixing the connection circuit portion to one surface of the heat sink with screws in parallel with the power module and based on the configuration of the power module. The wiring connection step is a step of connecting the wiring component of the power module and the busbar of the connection circuit portion by screws or welding. The control substrate connection step is a step of inserting the signal terminal of the power module into the signal terminal insertion hole of the control substrate for controlling the semiconductor element, and connecting the control substrate and the power module.

[0052] In the comparative example of a method for manufacturing a power conversion device, the connection circuit section does not include any components related to the positioning of the power modules. Instead, the power conversion device is manufactured based on the initial placement of the power modules. Consequently, assembly of components based on the initial placement of the power modules degrades the positional accuracy of the connections between the external devices connected to the power conversion device, such as the motor and battery, and the externally connected busbars of the power conversion device.

[0053] <Method of Manufacturing Power Conversion Device 100>

[0054] For the manufacturing method of the power conversion device 100, refer to Figure 7 The method for manufacturing the power conversion device 100 includes a component preparation step ( S11 ), a circuit connection step ( S12 ), a power module connection step ( S13 ), a wiring connection step ( S14 ), and a control substrate connection step ( S15 ).

[0055] The component preparation step involves preparing a power module 10 having semiconductor elements, a heat sink 80, and a connection circuit unit 50 having busbars (AC busbar 51, DC busbar 53), and metal terminals 20 insulated from the busbars. In the power module 10, when the semiconductor elements 11 and other power module components are sealed with molding resin 15, signal terminal spacing-enforcing resin 18 is applied through resin molding. The connection circuit unit connection step involves positioning the connection circuit unit 50 on one surface of the heat sink 80, where the metal terminals 20 of the connection circuit unit 50 are exposed from the connection circuit unit 50, and achieving both thermal and mechanical connection through soldering, such as brazing.

[0056] The power module connection step involves interlocking the power module interlocking portion 18a of the signal terminal pitch-enforcing resin 18 on the connection circuit portion 50 side of the power module 10 with the first interlocking portion 54 of the connection circuit portion 50 on the power module 10 side, arranging the connection circuit portion 50 and the power module 10 side by side on one surface of the heat sink 80, positioning the power module 10 relative to the connection circuit portion 50, and thermally connecting the power module 10 to one surface of the heat sink 80 by soldering or other means. The wiring connection step involves connecting the power module wiring members 13a and 13b to the busbars of the connection circuit portion 50 using screws or welding. The control board connection step involves inserting the signal terminals 17 of the power module 10 into the signal terminal insertion holes 91 of the control board 90 that controls the semiconductor element 11, thereby connecting the control board 90 and the power module 10. The control board 90 is positioned relative to the connection circuit unit 50 on one side of one surface of the heat sink 80 by the control unit fitting portion 92 and the second fitting portion 55 fitting together.

[0057] Through this manufacturing process, the connection circuit unit 50 is initially positioned and fixed to the heat sink 80 via the metal terminals 20, and then the power module 10 is positioned relative to the connection circuit unit 50. Therefore, tolerances based on the position of the power module 10 are not accumulated in the external output connections 58 and 59 of the connection circuit unit 50, which connect to the external components, such as the busbars. This can suppress degradation in the placement accuracy of the external output connections 58 and 59. Furthermore, since the connection circuit unit 50 is initially positioned and fixed to the heat sink 80 via the metal terminals 20, and then the power module 10 is positioned relative to the connection circuit unit 50, and the control board 90 is positioned relative to the connection circuit unit 50, this prevents degradation in the placement accuracy of the signal terminal insertion holes 91 of the control board 90 from accumulating. Consequently, the signal terminals 17 of the power module 10 can be easily inserted into the signal terminal insertion holes 91.

[0058] The connection method of connecting the connection circuit part 50 to the heat sink 80 and the connection method of connecting the power module 10 to the heat sink 80 are both brazing such as soldering, but these connection methods are not limited to this. These connection methods can also be connected by screws. In the case where the connection method is brazing such as soldering, the heat sink 80, the connection circuit part 50 and the power module 10 can be thermally connected more effectively. In addition, since screw holes are not required, the processing parts can be reduced, thereby improving the production efficiency of the power conversion device 100. In the case where the connection methods of the connection circuit part 50 and the power module 10 are each set to the same connection method, since multiple components are not required, the production efficiency of the power conversion device 100 can be improved.

[0059] Furthermore, the steps of connecting the circuit unit 50 to the heat sink 80 and the steps of connecting the power module 10 to the heat sink 80 can be performed simultaneously in a single connection step (S16), rather than separately. By performing these steps simultaneously in a single connection step (S16), the production process can be shortened, thereby improving the production efficiency of the power conversion device 100.

[0060] In the first embodiment, the power conversion device 100 is described as an example of a device that controls one motor, but the structure of the power conversion device 100 is not limited thereto. The same structure can also be applied to a power conversion device that controls two motors.

[0061] As described above, the power conversion device 100 of Embodiment 1 includes a busbar that electrically connects the power module 10 to the outside, and metal terminals 20 insulated from the busbar. The connection circuit unit 50, arranged side by side with the power module 10 on one surface of the heat sink 80, is thermally and mechanically connected to one surface of the heat sink 80 at the portion of the metal terminal 20 that is exposed from the connection circuit unit 50. Consequently, the connection circuit unit 50 is positioned and fixed to the heat sink 80 via the metal terminal 20. This prevents the accumulation of tolerances based on the position of the power module 10 on the externally connected busbar components of the connection circuit unit 50, thereby minimizing the deterioration in the accuracy of the placement of the external output connections 58 and 59. Furthermore, since no additional tolerance absorbing structure is required, the size of the power conversion device 100 can be minimized. The metal terminals 20 arranged around the AC busbar 51 transfer heat from the AC busbar 51 to the heat sink 80.

[0062] When the power module mating portion 18a and the first mating portion 54 are mated, and the power module 10 is positioned relative to the connection circuit portion 50 on one surface of the heat sink 80, the connection circuit portion 50 is positioned and fixed to the heat sink 80 via the metal terminals 20. The power module 10 is positioned relative to the connection circuit portion 50, and tolerances based on the position of the power module 10 are not accumulated on the external output connection portions 58 and 59 of the busbars, which are components of the connection circuit portion 50 that connect to the outside. This can suppress degradation in the accuracy of the placement of the external output connection portions 58 and 59. Furthermore, since no additional tolerance absorbing structure is required, the size of the power conversion device 100 can be suppressed. Furthermore, no positioning portion is required between the power module 10 and the heat sink 80, thereby improving the productivity of the power conversion device 100.

[0063] When the control unit fitting portion 92 and the second fitting portion 55 are mated with each other, and the control substrate 90 is positioned relative to the connection circuit portion 50 on one side of the heat sink 80, the connection circuit portion 50 is positioned and fixed to the heat sink 80 via the metal terminals 20. The power module 10 is positioned relative to the connection circuit portion 50, and the control substrate 90 is positioned relative to the connection circuit portion 50. Consequently, tolerances based on the position of the power module 10 are not accumulated in the signal terminal insertion holes 91 of the control substrate 90, thus suppressing degradation in the positioning accuracy of the signal terminal insertion holes 91. Consequently, the signal terminals 17 of the power module 10 can be easily inserted into the signal terminal insertion holes 91. Furthermore, since no additional tolerance absorbing structure is required, the size of the power conversion device 100 can be suppressed. Furthermore, since high-precision machining of the signal terminals 17 or the signal terminal insertion holes 91 is not required to facilitate insertion of the signal terminals 17 into the signal terminal insertion holes 91, the productivity of the power conversion device 100 can be improved.

[0064] When the connection circuit portion 50 includes a plurality of metal terminals 20, and a portion or all of the plurality of metal terminals 20 are integrated within the connection circuit portion 50, the integration of the plurality of metal terminals 20 can improve the rigidity of the connection circuit portion 50. The plurality of metal terminals 20 disposed around the AC busbar 51 can effectively transfer heat generated in the AC busbar 51 to the heat sink 80.

[0065] The manufacturing method of the power conversion device 100 of the embodiment 1 includes: a component preparation step of preparing a power module 10, a heat sink 80, and a connection circuit unit 50 having a bus bar and a metal terminal 20 insulated from the bus bar; a connection circuit unit connection step of thermally and mechanically connecting the connection circuit unit 50 to one surface of the heat sink 80 via the metal terminal 20 of the connection circuit unit 50; and a step of aligning a power module fitting portion 18a of the power module 10 on the connection circuit unit 50 side with a first fitting portion 54 of the connection circuit unit 50 on the power module 10 side. The power module connection process involves thermally connecting the power module 10 to one surface of the heat sink 80 by interfitting the power module 10. Initially, the connection circuit unit 50 is positioned and fixed to the heat sink 80 via the metal terminals 20. The power module 10 is then positioned relative to the connection circuit unit 50. Consequently, tolerances based on the position of the power module 10 are not accumulated on the external output connections 58 and 59 of the busbars, which are components of the connection circuit unit 50 that connect to the outside. This prevents deterioration in the accuracy of the placement of the external output connections 58 and 59. Furthermore, since no additional tolerance-absorbing structure is required, the size of the power conversion device 100 can be reduced, improving the productivity of the power conversion device.

[0066] When the connection circuit unit connection process and the power module connection process are performed simultaneously, the production process can be shortened, thereby improving the productivity of the power conversion device 100. In addition, when the connection method of the connection circuit unit 50 to the heat sink 80 and the connection method of the power module 10 to the heat sink 80 are the same, since multiple components are not required, the productivity of the power conversion device 100 can be improved. In addition, when the connection method of the connection circuit unit 50 to the heat sink 80 and the connection method of the power module 10 to the heat sink 80 are brazing, the heat sink 80, the connection circuit unit 50, and the power module 10 can be thermally connected more efficiently. In addition, since screw holes are not required, the number of processing parts can be reduced, thereby improving the productivity of the power conversion device 100.

[0067] In this embodiment, the connection circuit portion 50 is fixed to the heat sink 80 , but the location where the connection circuit portion 50 is provided is not limited to the heat sink 80 . The connection circuit portion 50 may also be fixed to the housing 70 .

[0068] Implementation method 2.

[0069] A power conversion device 100 according to Embodiment 2 and a method for manufacturing the same will be described. Figure 8 is a plan view showing an outline of a power conversion device 100 according to Embodiment 2. Figure 9 It is from Figure 1 A cross-sectional view of the power conversion device 100 cut at the BB cross-sectional position, Figure 10 It is a diagram showing a manufacturing process of the power conversion device 100 according to the second embodiment. Figure 8 1 is a plan view showing a state where the control substrate 90 positioned in the connection circuit portion 50 is removed. Figure 9 The dashed line is a cross-sectional view showing the outer shape of the control substrate 90. In the power conversion device 100 of the second embodiment, the metal terminal 20 is provided at a position different from that of the first embodiment. The power conversion device 100 of the second embodiment is manufactured using a manufacturing method different from that of the first embodiment.

[0070] The connection circuit portion 50 of the power conversion device 100 has a plurality of metal terminals 20. The plurality of metal terminals 20 are arranged along the outer periphery of the connection circuit portion 50 at positions in contact with one surface of the radiator 80. At the portion of one surface of the radiator 80 that contacts the metal terminal 20, the other surface of the radiator 80 contacts the surface of the housing 70 that supports the radiator 80. The material of the metal terminal 20 is, for example, copper, aluminum, iron, or a resin mixed with a metal material. A sealing member 95 is provided around the flow path provided on the inner side of the surface of the housing 70 that supports the radiator 80. The sealing member 95 is, for example, a gasket. By providing the sealing member 95, it is possible to suppress the refrigerant from flowing out to the outside.

[0071] For the manufacturing method of the power conversion device 100, refer to Figure 10 The manufacturing method of the power conversion device 100 includes a component preparation step ( S21 ), a power module connection step ( S22 ) for positioning the power module 10 on the connection circuit unit 50 , a connection circuit unit connection step ( S23 ), a wiring connection step ( S24 ), and a control substrate connection step ( S25 ). The wiring connection step ( S24 ) and the control substrate connection step ( S25 ) are the same as those in the first embodiment, and therefore their description is omitted.

[0072] The component preparation step is a step of preparing a power module 10 having a semiconductor element 11, a heat sink 80, a connection circuit unit 50 having busbars (AC busbar 51, DC busbar 53) and metal terminals 20 insulated from the busbars, and a housing 70 that supports the other side of the heat sink 80. In power module 10, while the components of power module 10, such as semiconductor element 11, are sealed with molding resin 15, signal terminal spacing-enforcing resin 18 is provided by resin molding.

[0073] The power module connection process is a process of interlocking the power module interlocking portion 18a of the power module 10 on the connection circuit portion 50 side and the first interlocking portion 54 of the connection circuit portion 50 on the power module 10 side, arranging the connection circuit portion 50 and the power module 10 side by side on one surface of the heat sink 80, positioning the power module 10 relative to the connection circuit portion 50, and thermally connecting the power module 10 to one surface of the heat sink 80 by brazing such as soldering.

[0074] The connecting circuit portion connecting process is a process of thermally and mechanically connecting the connecting circuit portion 50 to one surface of the heat sink 80 at the portion of the metal terminal 20 exposed to the outside from the connecting circuit portion 50, and thermally and mechanically connecting the other surface of the heat sink 80 to the housing 70. In the connecting circuit portion connecting process, the metal terminal 20 and the heat sink 80, and the heat sink 80 and the housing 70 are connected by friction stir welding or welding. The joining portion is a portion where the metal terminal 20 is arranged. The metal terminal 20 is arranged at a position that suppresses the outflow of refrigerant to the outside. The joining is performed by pushing a processing tool onto the metal terminal 20. The joining can be carried out at multiple locations simultaneously, or it can be carried out sequentially along the periphery of the connecting circuit portion 50.

[0075] As described above, the manufacturing method of the power conversion device 100 of the second embodiment includes: a component preparation step of preparing a power module 10, a heat sink 80, a connection circuit portion 50 having a bus bar and a metal terminal 20 insulated from the bus bar, and a housing 70 supporting the other side of the heat sink 80; a power module connection step of thermally connecting the power module 10 to one side of the heat sink 80 by engaging the power module fitting portion 18a of the power module 10 on the connection circuit portion 50 side with the first fitting portion 54 of the connection circuit portion 50 on the power module 10 side; and a power module connection step of thermally and mechanically connecting the connection circuit portion 50 to one side of the heat sink 80 via the metal terminal 20. At the same time, the other surface of the heat sink 80 is thermally and mechanically connected to the housing 70 in the connection circuit portion connection process. In the connection circuit portion connection process, the metal terminal 20 and the heat sink 80, as well as the heat sink 80 and the housing 70 are connected by friction stir welding or welding. Therefore, although the power module 10 is initially fixed, the power module 10 is positioned relative to the connection circuit portion 50 to be fixed next. Therefore, the external output connection portions 58 and 59 of the busbar, which are components connected to the outside of the connection circuit portion 50, will not accumulate tolerances based on the position of the power module 10, and the deterioration of the accuracy of the configuration of the external output connection portions 58 and 59 can be suppressed.

[0076] In addition, since there is no need to provide a tolerance absorption structure separately, the size of the power conversion device 100 can be suppressed. In addition, the connection method between the metal terminal 20 and the heat sink 80, and the heat sink 80 and the housing 70 is friction stir welding or welding, so the metal terminal 20 and the heat sink 80, and the heat sink 80 and the housing 70 can be firmly joined. Since the metal terminal 20 is firmly joined to the heat sink 80, the connection circuit part 50 can be effectively cooled. In addition, since the metal terminal 20 and the heat sink 80, and the heat sink 80 and the housing 70 are joined at the same time, the production process can be shortened, thereby improving the productivity of the power conversion device 100. In addition, since screw holes are not required, the processing parts can be reduced, thereby improving the productivity of the power conversion device 100.

[0077] In addition, although the present application describes various exemplary embodiments and examples, the various features, methods, and functions described in one or more embodiments are not limited to being applicable to specific embodiments, but can also be applied to the embodiments alone or in various combinations to be applied to the embodiments.

[0078] Therefore, it is considered that numerous modifications not shown in the examples are also included in the technical scope disclosed in this specification. For example, it is assumed that at least one component is modified, added, or omitted, and at least one component is extracted and combined with components of other embodiments.

[0079] Description of labels

[0080] 10 Power module, 11 Semiconductor element, 12 Wiring member for semiconductor element, 13a Wiring member for power module, 13b Wiring member for power module, 14 Conductive bonding material, 15 Molding resin, 16 Insulating member, 17 Signal terminal, 18 Signal terminal pitch-enforcing resin, 18a Power module fitting portion, 20 Metal terminal, 20a Terminal connection portion, 30 Capacitor module, 31 Wiring member for capacitor, 50 Connecting circuit portion, 50a Connecting circuit portion, 51 AC busbar, 52 Molding resin, 53 DC busbar, 54 First fitting portion, 55 Second fitting portion, 58 External output connection portion, 59 External output connection portion, 70 Case, 71 Positioning pin, 80 Heat sink, 81 Heat sink fin, 82 First flow path portion, 83 Second flow path portion, 90 Control board, 91 Signal terminal insertion hole, 92 Control unit fitting portion, 93 Current sensor, 94 Capacitor cover, 95 Sealing member, 96 Solder, 100 Power conversion device

Claims

1. A power conversion device, characterized in that: include: A power module having a semiconductor component; a heat sink thermally connected to the power module; as well as a connection circuit portion having a bus bar for electrically connecting the power module to the outside and a metal terminal insulated from the bus bar and arranged side by side with the power module on one surface of the heat sink; The connection circuit portion is thermally and mechanically connected to one surface of the heat sink at a portion of the metal terminal exposed to the outside from the connection circuit portion.

2. The power conversion device according to claim 1, wherein: The power module has a power module fitting portion on one side of the connection circuit portion. The connection circuit portion has a first fitting portion on the power module side. The power module fitting portion and the first fitting portion fit together, so that the power module is positioned relative to the connection circuit portion on one surface of the heat sink.

3. The power conversion device according to claim 2, wherein: The power conversion device includes a control unit for controlling the semiconductor element, which is arranged on one surface side of the heat sink and faces the power module and the connection circuit unit. The control unit has a control unit fitting portion at a portion facing the connection circuit unit. The connection circuit portion has a second fitting portion at a portion facing the control portion. The control unit fitting portion and the second fitting portion fit together, so that the control unit is positioned relative to the connection circuit unit on one surface side of the heat sink.

4. The power conversion device according to any one of claims 1 to 3, wherein: The connecting circuit portion has a plurality of metal terminals. A part or all of the plurality of metal terminals are integrated inside the connection circuit portion.

5. A method for manufacturing a power conversion device, characterized in that: include: a component preparation step of preparing a power module including a semiconductor element, a heat sink, and a connection circuit portion including a bus bar and a metal terminal insulated from the bus bar; a connecting circuit portion connecting step of thermally and mechanically connecting the connecting circuit portion to one surface of the heat sink at a portion of the metal terminal of the connecting circuit portion exposed to the outside; and A power module connecting step in which a power module engaging portion of the power module on the connection circuit portion side is engaged with a first engaging portion of the connection circuit portion on the power module side, thereby thermally connecting the power module to one surface of the heat sink.

6. The method for manufacturing a power conversion device according to claim 5, wherein: The connection circuit portion connecting step and the power module connecting step are performed simultaneously.

7. The method for manufacturing a power conversion device according to claim 5 or 6, wherein: A connection method of connecting the connection circuit portion to the heat sink is the same as a connection method of connecting the power module to the heat sink.

8. The method for manufacturing a power conversion device according to claim 7, wherein: The connection method is brazing.

9. A method for manufacturing a power conversion device, characterized in that: include: a component preparation step of preparing a power module having a semiconductor element, a heat sink, a connection circuit portion having a bus bar and a metal terminal insulated from the bus bar, and a housing supporting the other surface of the heat sink; a power module connecting step in which a power module engaging portion of the power module on one side of the connecting circuit portion is engaged with a first engaging portion of the connecting circuit portion on the power module side, thereby thermally connecting the power module to one surface of the heat sink; as well as a connecting circuit portion connecting step, in which the connecting circuit portion is thermally and mechanically connected to one surface of the heat sink at a portion of the metal terminal exposed to the outside from the connecting circuit portion, and the other surface of the heat sink is thermally and mechanically connected to the housing, In the circuit portion connecting step, the metal terminal and the heat sink, and the heat sink and the housing are connected by friction stir welding or welding.

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