POWER CONVERSION DEVICE

Abstract

A power conversion device comprises: a plurality of semiconductor modules; and a printed circuit board connected to the semiconductor module by a through-hole, wherein the semiconductor element includes a plurality of signal terminals and a plurality of main terminals, the plurality of signal terminals and the plurality of main terminals projecting outwards from the semiconductor module in opposite directions, and each of the plurality of signal terminals having a bent section at a position between the semiconductor module and the printed circuit board.

Description

Technical field

[0001] The present invention relates to a power conversion device. State of the art

[0002] In addition to the requirement for size and height reduction, the power conversion device must be designed for ease of manufacture. In this respect, adopting a configuration where main circuit wiring is integrated on a printed circuit board eliminates a connection section, thus improving size, height, and productivity. Accordingly, the reliability of a connection section or similar component is essential when configuring the power conversion device.

[0003] As an example of a configuration to improve the reliability of a power conversion device, PTL 1 discloses a configuration in which, in order to suppress excessive heat conduction from a semiconductor package to a control board, the semiconductor package includes a control signal input line having a shape that is bent in one direction away from the semiconductor package, a control board is mounted at one end of the control signal input line, and an air layer is provided between the semiconductor package and the control board. Citation list of patent literature

[0004] PTL 1: JP 2013 - 157 485 A Summary of the invention: Technical problem

[0005] In an inverter configuration where the main circuit wiring is integrated with the printed circuit board (PCB), and which is further required to be smaller and lower in size and higher in productivity compared to conventional configurations, the PCB stiffness is reduced due to the through-hole created for the semiconductor package. When the semiconductor package, which includes a sealing element with a coefficient of linear expansion greater than that of the PCB, is inserted into the through-hole and connected to the PCB, a problem arises: warping occurs on the PCB side due to the difference in their coefficients of linear expansion.Furthermore, if the circuit board is mounted to a water channel, the problem arises that excessive tensile stress is generated in a solder joint section, and the reliability during the connection process is reduced.

[0006] In this respect, it is an object of the present invention to provide a power conversion device that suppresses distortion of a plate during the joining of a semiconductor module and a printed circuit board, reduces the voltage on the solder joint section during water channel assembly, and avoids an increase in the main circuit inductance. Solution to the problem

[0007] A power conversion device comprises: a plurality of semiconductor modules in which a semiconductor element that converts direct current power into alternating current power is sealed with a sealing element;and a printed circuit board having a through-hole and being connected to the semiconductor module through the through-hole, the semiconductor element comprising a plurality of signal terminals and a plurality of main terminals, the printed circuit board comprising signal wiring connected to the signal terminal and main circuit wiring connected to the main terminal, the semiconductor module performing switching control of the line between the main terminals based on a control signal input via the signal terminal, the plurality of signal terminals and the plurality of main terminals projecting outwards from the semiconductor module in opposite directions, and each of the plurality of signal terminals having a bent section at a position between the semiconductor module and the printed circuit board. Advantageous effects of the invention

[0008] It is possible to provide the power conversion device that suppresses distortion of a plate during joining, reduces the voltage on a connecting section during water channel assembly, and avoids an increase in the main circuit inductance. Brief description of the drawings Fig. Figure 1 shows an electrical circuit diagram according to a power conversion device of the present invention. Fig. Figure 2 shows a perspective view and a top view of the power conversion device according to an embodiment of the present invention. Fig. Figure 3 shows a top view and a cross-sectional view along line AA' of the power conversion device for one phase according to an embodiment of the present invention. Fig. Figure 4 shows an explanatory view and a perspective view of a configuration of a semiconductor module according to an embodiment of the present invention. Fig. Figure 5 shows a first modification. Fig. Figure 6 shows a second modification. Fig. Figure 7 shows a third modification. Fig. Figure 8 shows an exterior view of Fig. 7.

[0009] The following describes embodiments of the present invention with reference to the drawings. The following description and the drawings are examples used to describe the present invention and have been omitted or simplified where necessary for clarity. The present invention can be implemented in various other forms. Unless otherwise specified, each component can be present singly or in multiples.

[0010] The position, size, shape, area, and the like of each component shown in the drawings may not represent the actual position, size, shape, area, and the like, for the sake of clarity and to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, areas, and the like disclosed in the drawings. (An embodiment and overall configuration of the present invention) (FIG. 1)

[0011] A power conversion device 1 comprises a plurality of semiconductor devices that perform power conversion over three phases: a U-phase, a V-phase, and a W-phase. Each semiconductor device includes an upper-branch semiconductor element 4a and a lower-branch semiconductor element 4b. Examples of semiconductor elements used for the upper-branch semiconductor element 4a and the lower-branch semiconductor element 4b include an insulated-gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), or the like.

[0012] Each of the semiconductor element 4a of the upper branch and the semiconductor element 4b of the lower branch is provided with three terminals, including a main circuit high-voltage side terminal (a collector terminal for IGBT, a drain terminal for MOSFET), a main circuit low-voltage side terminal (an emitter terminal for IGBT, a source terminal for MOSFET), and a signal terminal (such as a gate terminal).

[0013] A plurality of semiconductor elements 4a of the upper branch and a plurality of semiconductor elements 4b of the lower branch are formed and connected in parallel, thereby increasing the output current of the power conversion device 1. In the power conversion circuit for any phase of the U-phase, V-phase, and W-phase, the semiconductor element 4a of the upper branch and the semiconductor element 4b of the lower branch, connected in series, are paired with a capacitor 8. The capacitor 8 is, for example, a film capacitor or an electrolytic capacitor with a large electrostatic capacitance. By arranging such a capacitor 8 near the semiconductor element 4a of the upper branch and the semiconductor element 4b of the lower branch, the wiring inductance of a positive electrode wiring 2 and a negative electrode wiring 3 is reduced.Additionally, a small ceramic capacitor 7 is connected in parallel for each phase unit.

[0014] An output wiring 6 of each phase is connected to a load such as a motor (not shown). Additionally, the output wiring 6 connects a plurality of the semiconductor elements 4a of the upper branch and a plurality of the semiconductor elements 4b of the lower branch. The positive electrode wiring 2 is connected to a positive electrode terminal of a DC power supply such as a battery (not shown), and the negative electrode wiring 3 is connected to a negative electrode terminal of the DC power supply such as a battery. Accordingly, a DC voltage is applied to the semiconductor device (power conversion circuit) of each phase.

[0015] The positive electrode terminals of the ceramic capacitor 7 and the film capacitor 8 are connected via the positive electrode wiring 2 to the main circuit high-voltage side terminal of the semiconductor element 4a of the upper branch. Additionally, the negative electrode terminals of the ceramic capacitor 7 and the film capacitor 8 are connected via the negative electrode wiring 3 to the main circuit low-voltage side terminal of the semiconductor element 4b of the lower branch.

[0016] The main circuit low-voltage terminal of semiconductor element 4a of the upper branch is connected via the output wiring 6 of each phase to the main circuit high-voltage terminal of semiconductor element 4b of the lower branch. The positive electrode wiring 2 is connected to the positive electrode terminal of capacitor 7 of another phase and to the main circuit high-voltage terminal of semiconductor element 4a of the upper branch of another phase. The negative electrode wiring 3 is connected to the negative electrode terminal of capacitor 7 of another phase and to the main circuit low-voltage terminal of semiconductor element 4b of the lower branch of another phase. In this way, a circuit with multiple phases can be constructed.

[0017] The capacitor 8 is, for example, the film capacitor 8 with a large electrostatic capacitance, the small ceramic capacitor 7 or the like, and by arranging the capacitor 8 near the semiconductor element 4a of the upper branch and the semiconductor element 4b of the lower branch, the wiring inductance of the positive electrode wiring 2 and the negative electrode wiring 3 can be reduced.

[0018] In the semiconductor element 4a of the upper branch and the semiconductor element 4b of the lower branch, a signal terminal such as a gate terminal is connected to a control circuit (not shown) and is switched on or off based on a signal input from a higher-level control device such as a microcomputer, thereby outputting an alternating voltage to a load such as a motor. (FIG. 2)

[0019] Fig. Figure 2(a) shows a perspective overall view of the power conversion device 1, and Fig. Figure 2(b) shows a general plan view of the power conversion device 1. Each of the plurality of capacitors 8 is connected to the positive electrode wiring 2 and the negative electrode wiring 3, which are provided on a printed circuit board 18, which is a control board. The positive electrode wiring 2 and the negative electrode wiring 3 include a DC input terminal 22 and conduct DC power, supplied by a battery or the like, to the semiconductor module 20, 21.

[0020] In the case of a type with a large electrostatic capacitance such as the film capacitor 8, the plurality of capacitors 8 are arranged side by side on the side of the circuit board 18 along a direction in which the semiconductor devices with three phases of the U-phase, the V-phase and the W-phase are arranged, so that it is easy to attach the power conversion device 1 to a housing (not shown), and thus the vibration resistance can be improved.

[0021] The semiconductor modules 20 of the upper branch, in which the semiconductor device including the semiconductor element 4a of the upper branch described above is formed and sealed, and the semiconductor modules 21 of the lower branch, in which the semiconductor device including the semiconductor element 4b of the lower branch described above is formed and sealed, each extend in a line from the capacitor 8 towards an output terminal 6a, thus shortening the lengths of the positive electrode wiring 2, the negative electrode wiring 3, and the output wiring 6. This facilitates a reduction in the size of the power conversion device 1. Additionally, this contributes to a reduction in the size of an externally mounted heatsink and simplifies its installation. (FIG. 3)

[0022] Fig. 3(a) shows a top view representing a state of the power conversion device 1 for one phase in which a plurality of semiconductor modules are connected via a circuit board wiring, and Fig. 3(b) shows a cross-sectional view along line AA' of Fig. Figure 3(a) is a configuration example of the semiconductor module 20 of the upper branch. In each of the plurality of semiconductor modules 20, 21, the semiconductor element 4a, 4b described above, which converts DC power into AC power, is sealed by a sealing element 17.

[0023] The printed circuit board 18 has a through-hole 23 and is connected to the semiconductor module 20, 21 through the through-hole 23. The printed circuit board 18 includes a signal wiring 15, which is connected via a connection section 14, such as solder, to a control terminal (signal terminal) 11, and an output wiring 6, which is a main circuit wiring, which is connected via the connection section 14, such as solder, to a main terminal 9, 10 of the semiconductor element of the upper branch and a main terminal 12, 13 of the semiconductor element of the lower branch. In the printed circuit board 18, the signal wiring 15 and the output wiring 6, which are connected via the terminals to the semiconductor element 4a of the upper branch and the semiconductor element 4b of the lower branch, form a first layer of the board.

[0024] The semiconductor element 4a, 4b has a plurality of signal terminals 11 and a plurality of main terminals. The semiconductor module 20 performs switching control of the line between the main terminals based on a control signal input via the signal terminal 11.

[0025] The positive electrode wiring 2, the negative electrode wiring 3, and the output wiring 6, formed in the first layer of the printed circuit board 18, are electrically connected to another layer by an interlayer connection section 5, which is formed by a through-hole or the like. By providing a large number of interlayer connection sections 5 on the printed circuit board 18, the cross-sectional area of ​​the current flowing in one cross-sectional direction of the printed circuit board 18 can be increased, thus reducing the electrical resistance and consequently the heat generation in the wiring. Furthermore, since the thermal conductivity in the cross-sectional direction of the printed circuit board 18 is improved by the interlayer connection section 5, an increase in the wiring temperature can be suppressed. (FIG. 4)

[0026] Fig. Figure 4(a) shows a top view to illustrate a condition in which the signal terminal and the main terminal of the semiconductor module 20, 21 protrude outwards in the semiconductor module 20, 21. Fig. 4(b) shows a perspective view of Fig. 4(a). The terminal projecting from the semiconductor module is described below based on the semiconductor module 20 of the upper branch. In the semiconductor module 20, a plurality of signal terminals 11 and a plurality of main terminals 9, 10 project from the semiconductor module 20 in opposite directions. Additionally, each of the plurality of signal terminals 11 has a curved section 11b at a position between the semiconductor module 20 and the printed circuit board 18.

[0027] In the semiconductor module 20, the bent section 11b has a projection 11c, and the projection 11c of the bent section 11b of one signal terminal 11 and the projection 11c of the bent section 11b of another signal terminal 11 are formed such that they face each other. In other words, in the semiconductor module 20, the bent sections 11b are bent in directions that approach each other.

[0028] The reason for adopting this configuration is that the stiffness of the printed circuit board 18 is reduced by providing the through-hole 23 in the board 18. That is, since the semiconductor module 20 and the printed circuit board 18 to be connected have different coefficients of linear expansion, a problem arises in that the shrinkage of the semiconductor module 20 becomes greater than that of the printed circuit board 18 when the two are soldered together, and the semiconductor module is pulled towards the center of the through-hole 23. A difference in the shrinkage between the semiconductor module 20 and the printed circuit board 18 is mitigated by a slight displacement of the bent section 11b of the signal connector 11. Accordingly, distortion of the printed circuit board 18 during the connection of the semiconductor module 20 can be reduced.

[0029] The curved section 11b is not bent vertically, but rather in the direction in which the signal terminals 11 are arranged. Accordingly, when connecting the semiconductor module 20 and the printed circuit board 18, it is possible to solve a problem where the curved section 11b obstructs the lamination due to the arrangement of a heat dissipation element 16 or the like, as described later. This contributes to reducing the height and size of the power conversion device 1. Furthermore, since the curved sections 11b are bent in directions that approach each other, a creepage distance of a connection root in the signal terminal 11 can be ensured, and the insulation performance can be improved.

[0030] Additionally, by placing the curved section 11b not at the main terminal 9, 10, but only on the side of the signal terminal 11, through which no large current flows, it is possible to avoid the increase in inductance and heat generation that would occur if the curved section were located on the side of the main terminal 9, 10, through which a large current flows. This improves the reliability of the connection section. Furthermore, since the signal terminal 11 is easier to modify than the main terminal 9, 10, which is affected by a current increase, this facilitates design changes. Moreover, because the signal terminal 11 and the main terminal 9, 10 are located on the top side of the semiconductor module 20, the connection to the printed circuit board 18 is simplified, thus reducing costs.It should be noted that the signal terminal 11 may be designed so that its length is within a range that does not impair performance, or the main terminal 9, 10 may be shortened accordingly.

[0031] By positioning the signal terminal 11 and the main terminal 9, 10 on opposite sides of the semiconductor module 20, magnetic coupling during the switching process can be minimized. Additionally, the influence of magnetism is minimized by providing the curved section 11b on the side of the signal terminal 11.

[0032] It should be noted that, from the point of view of improving productivity, the length of the projection 11c, which extends beyond the width of the signal terminal 11, is preferably greater than the width of the signal terminal 11. Additionally, the bent sections 11b can be bent in the same direction relative to each other or bent outwards relative to each other, as long as an isolation distance can be ensured. (First modification) (FIG. 5)

[0033] Fig. Figure 5(a) shows an explanatory view of a configuration of a semiconductor module, which shows a first modification of an embodiment of the present invention, and Fig. 5(b) shows a perspective overall view of Fig. 5(a). Features of the first modification are described based on the semiconductor module 20 of the upper branch.

[0034] The curved section 11b is bent in one thickness direction of the printed circuit board 18. In the above with reference to the Fig. In the embodiment described in sections 1 to 4, it was necessary to follow a method in which the bent section 11b is produced and then the bent section is fitted into a mold. In particular, in the case of the bent section 11b with a bent mold in a plane direction of the printed circuit board 18, which is described with reference to Fig. As described in section 4, it is necessary to form the curved shape during the looping of the signal connection 11, and the curved shape may interfere with the shape of the sealing element 17.

[0035] With the shape of the curved section 11b of the first modification, the curved section 11b can still be formed in the signal terminal 11 even after the semiconductor module 20 has been shaped and sealed by the sealing element 17. Accordingly, it is possible to improve the manufacturability of the power conversion device 1. However, a design that takes into account the installation of the heat dissipation element 16 is necessary to prevent contact between the heat dissipation element 16 and the semiconductor module 20, which will be described later. (Second modification) (FIG. 6)

[0036] Fig. Figure 6(a) shows an explanatory view of a configuration of a semiconductor module, which shows a second modification of an embodiment of the present invention, and Fig. 6(b) shows a perspective overall view of Fig. 6(a). Features of the second modification are described based on the semiconductor module 20 of the upper branch. In the semiconductor module 20, each bent section 11b has an L-shape in the same direction and falls within a region the size of the semiconductor module 20 in a planar direction. In this way, productivity is improved by giving the bent section 11b an L-shaped bend with a simpler form compared to that in the Fig. 4 and Fig. The U-shaped curved form described in section 5 is formed. Additionally, it is also possible to solve the problem of reducing the height and size by taking into account the installation of the heat dissipation element 16. (Third modification) (FIG. 7)

[0037] Features of the third modification are described based on the semiconductor module 20 of the upper branch. The heat dissipation elements 16 are provided on both surfaces of the semiconductor module 20 in the thickness direction and are in contact with the semiconductor module 20. For example, the heat dissipation element 16, which has a water channel therein, also exerts stress on the connection section during assembly onto the semiconductor module 20. However, if the configuration of the present invention is adopted, in which the signal terminal 11 is provided with the curved section 11b, double-sided cooling of the semiconductor module 20 can be achieved while maintaining the reliability of the connection section. It should be noted that, although the double-sided cooling configuration has been shown by way of example, single-sided cooling can also be used. (FIG. 8)

[0038] Fig. Figure 8(a) shows a perspective overall view in which the heat dissipation elements 16 on both surfaces of the above are shown with reference to Fig. 7 described power conversion device 1 are installed, and Fig. 8(b) shows an overall top view of Fig. 8(a). The heat dissipation elements 16 are arranged above and below the printed circuit board 18. This enables double-sided cooling of a plurality of semiconductor modules 20, 21 arranged on the printed circuit board 18, thereby improving the heat dissipation performance.

[0039] According to the embodiment of the present invention described above, the following operational effects are shown. (1) A power conversion device 1 comprises: a plurality of semiconductor modules 20, 21 in which a semiconductor element converting direct current power into alternating current power is sealed by a sealing element 17; and a printed circuit board 18 having a through-hole 23 and connected to the semiconductor module 20, 21 through the through-hole 23, wherein the semiconductor element 4a, 4b includes a plurality of signal terminals 11 and a plurality of main terminals, the printed circuit board 18 includes signal wiring connected to the signal terminal 11 and main circuit wiring connected to the main terminal, and the semiconductor module 20, 21 performs switching control of the line between the main terminals based on a control signal input via the signal terminal 11.The multiple signal terminals 11 and the multiple main terminals project outwards from the semiconductor module 20 in opposite directions, and each of the multiple signal terminals 11 has a curved section 11b at a position between the semiconductor module 20 and the printed circuit board 18. With this configuration, it is possible to provide the power conversion device 1, which suppresses distortion of the printed circuit board 18 during connection, reduces the stress on the connection section during assembly of the water channel 16, and avoids an increase in the main circuit inductance. (2) In the semiconductor module 20, 21, the curved section 11b has a projection 11c, and the projection 11c of the curved section 11b of one of the signal terminals 11 and the projection 11c of the curved section 11b of another of the signal terminals 11 are formed such that they face each other. With this configuration, it is possible to reduce the distortion of the printed circuit board 18 during the connection of the semiconductor module 20. (3) In the semiconductor module 20, 21, the bent sections 11b are bent in directions that approach each other. With such a configuration, the creepage distance of the root of the terminal in the signal terminal 11 can be ensured, and the insulation performance can be improved. (4) The curved section 11b is bent in one thickness direction of the printed circuit board 18. With this configuration it is possible to improve the manufacturability of the power conversion device 1. (5) In the semiconductor module 20, 21, each of the curved sections 11b has an L-shape in the same direction and falls within a region of the size of the semiconductor module 20, 21 in a planar direction. This configuration improves productivity. Additionally, it also solves the problem of reducing height and size by taking into account the installation of the heat dissipation element 16. (6) Heat dissipation elements 16 are provided on both surfaces of the semiconductor module 20, 21 in one thickness direction of the semiconductor module 20, 21. This configuration improves the heat dissipation performance.

[0040] It should be noted that the present invention is not limited to the embodiments described above and that various modifications and other configurations can be combined without departing from the essence of the present invention. Furthermore, the present invention is not limited to an embodiment that includes all the configurations described above and includes one in which part of the configuration is omitted. Reference symbol list 1 Power conversion device 2 Positive electrode wiring 3 Negative electrode wiring 4 Semiconductor element 4a Upper branch semiconductor element 4b Lower branch semiconductor element 5 Interlayer connection section 6 Output wiring 6a Output connection 7 Ceramic capacitor 8 Capacitor 9. Main circuit - low-voltage side connection of the semiconductor element of the upper branch 10 Main circuit - high-voltage side connection of the semiconductor element of the upper branch 11 Control connection (signal connection) 11b curved section 11c lead 12. Main circuit - low-voltage side connection of the semiconductor element of the lower branch 13 Main circuit - high-voltage side connection of the semiconductor element of the lower branch 14 Connection section 15 Signal wiring 16 Heat dissipation element 16a Heat dissipation surface 17 Sealing element 18 circuit boards 20 Upper branch semiconductor module 21 Lower branch semiconductor module 22 DC input terminal 23 Through hole QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2013 - 157 485 A

[0004]

Claims

[1] Power conversion device comprising: a variety of semiconductor modules in which a semiconductor element that converts direct current power into alternating current power is sealed with a sealing element; and a printed circuit board having a through hole and connected to the semiconductor module through the through hole, wherein The semiconductor element includes a variety of signal connections and a variety of main connections. The circuit board includes signal wiring connected to the signal terminal and main circuit wiring connected to the main terminal. the semiconductor module performs switching control of the line between the main terminals based on a control signal input via the signal terminal, the multitude of signal connections and the multitude of main connections protrude outwards from the semiconductor module in opposite directions, and Each of the numerous signal connections has a curved section at a position between the semiconductor module and the printed circuit board. [2] Power conversion device according to claim 1, wherein in the semiconductor module the curved section has a projection, and the projection of the curved section of one of the signal terminals and the projection of the curved section of another of the signal terminals are formed such that they face each other. [3] Power conversion device according to claim 2, wherein in the semiconductor module the bent sections are bent in directions that approach each other. [4] Power conversion device according to claim 1, wherein the bent section is bent in a thickness direction of the printed circuit board. [5] Power conversion device according to claim 1, wherein in the semiconductor module each of the bent sections has an L-shape in the same direction and falls into a region of a size of the semiconductor module in a planar direction. [6] Power conversion device according to claim 1, wherein heat dissipation elements are provided on both surfaces of the semiconductor module in one thickness direction of the semiconductor module.

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