Power conversion device

Abstract

To provide a power conversion device in which warpage of a substrate at the time of bonding is suppressed, stress of a bonding unit at the time of assembling a water channel is reduced, and increase in main circuit inductance is avoided.SOLUTION: A power conversion device includes a plurality of semiconductor modules and a wiring substrate connected to the semiconductor modules via through holes. 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 protrude outward from the semiconductor module in a direction opposite to each other. Each of the plurality of signal terminals has a bent portion at a position between the semiconductor module and the wiring substrate.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] In addition to the demand for smaller size and lower profile, power conversion equipment also needs to be designed to be easier to produce. Therefore, by adopting a configuration that integrates the main circuit wiring in a printed circuit board, it is possible to omit joints, making it smaller, lower profile, and more productive. Accordingly, reliability of joints, etc. in the configuration of power conversion equipment is required.

[0003] As an example of a configuration for improving the reliability of a power conversion device, Patent Document 1 discloses a configuration in which, in order to suppress excessive heat conduction from a semiconductor package to a control board, a semiconductor package has a control signal input lead that is bent in a direction away from the semiconductor package, a control board is mounted on the tip of the control signal input lead, and an air layer is provided between the semiconductor package and the control board. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-157485 A Summary of the Invention [Problem to be solved by the invention]

[0005] Inverters that use a configuration that integrates the main circuit wiring on a printed circuit board that is smaller, thinner, and more productive than conventional configurations have a through hole for inserting a semiconductor package, which reduces the rigidity of the printed circuit board. When a semiconductor package equipped with a sealing material with a linear expansion coefficient larger than that of the printed circuit board is inserted into the through hole of the board and connected to the printed circuit board, the difference in linear expansion coefficients causes the board to warp. In addition, when the printed circuit board is attached to the water channel, excessive tensile stress is generated at the solder joint, which causes the reliability of the joint to deteriorate.

[0006] In view of this, the present invention aims to provide a power conversion device that suppresses warping of the board when a semiconductor module is joined to a printed circuit board, reduces stress at the solder joint when assembling the water channel, and avoids an increase in main circuit inductance. [Means for solving the problem]

[0007] A power conversion device comprising: a plurality of semiconductor modules in which semiconductor elements that convert DC power to AC power are sealed with a sealing member; and a wiring board having a through hole and connected to the semiconductor modules via the through hole, wherein the semiconductor elements have a plurality of signal terminals and a plurality of main terminals, the wiring board has signal wiring connected to the signal terminals and main circuit wiring connected to the main terminals, the semiconductor modules switch-control the conduction between the main terminals based on a control signal input via the signal terminals, the plurality of signal terminals and the plurality of main terminals protrude outward from the semiconductor modules in opposite directions to each other, and the plurality of signal terminals each have a bent portion at a position between the semiconductor module and the wiring board. Effect of the Invention

[0008] It is possible to provide a power conversion device that suppresses warping of the board during joining, reduces stress at the joints when assembling the water channel, and prevents an increase in main circuit inductance. [Brief description of the drawings]

[0009] [Figure 1] Electrical circuit diagram of the power conversion device of the present invention. [Diagram 2] 1A and 1B are perspective and top views of a power conversion device according to an embodiment of the present invention; [Diagram 3] 1 is a top view and an A-A′ cross-sectional view of a power conversion device for one phase according to an embodiment of the present invention. [Figure 4] 1 is an explanatory diagram and a perspective view of a configuration of a semiconductor module according to an embodiment of the present invention; [Diagram 5] First Modification [Figure 6] Second Modification [Figure 7] Third Modification [Figure 8] External view of Fig. 7

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0011] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0012] (One embodiment of the present invention and overall configuration) (Figure 1) The power conversion device 1 is composed of a plurality of semiconductor devices that perform power conversion across three phases, namely, U phase, V phase, and W phase. Each of the semiconductor devices includes an upper arm semiconductor element 4a and a lower arm semiconductor element 4b. For example, an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is used for the upper arm semiconductor element 4a and the lower arm semiconductor element 4b.

[0013] The upper arm semiconductor element 4a and the lower arm semiconductor element 4b are provided with three terminals: a high-voltage side terminal for the main circuit (a collector terminal for an IGBT, or a drain terminal for a MOSFET), a low-voltage side terminal for the main circuit (an emitter terminal for an IGBT, or a source terminal for a MOSFET), and a signal terminal (such as a gate terminal).

[0014] A plurality of upper-arm semiconductor elements 4a and lower-arm semiconductor elements 4b are formed and connected in parallel to each other, thereby increasing the output current of the power conversion device 1. In a power conversion circuit for one of the U-phase, V-phase, and W-phase, a capacitor 8 is paired with the upper-arm semiconductor element 4a and the lower-arm semiconductor element 4b that are connected in series. The capacitor 8 is, for example, a film capacitor or an electrolytic capacitor having a large capacitance. By arranging such a capacitor 8 in the vicinity of the upper-arm semiconductor element 4a and the lower-arm semiconductor element 4b, the wiring inductance of the positive electrode wiring 2 and the negative electrode wiring 3 is reduced. In addition, a small ceramic capacitor 7 is connected in parallel for each phase.

[0015] The output wiring 6 of each phase is connected to a load such as a motor (not shown). The output wiring 6 also connects the upper arm semiconductor elements 4a and the lower arm semiconductor elements 4b. The positive wiring 2 is connected to the positive terminal of a DC power supply such as a battery (not shown), and the negative wiring 3 is connected to the negative terminal of the DC power supply such as a battery. This allows a DC voltage to be supplied to the semiconductor device (power conversion circuit) of each phase.

[0016] The positive terminals of the ceramic capacitor 7 and the film capacitor 8 are connected to the main circuit high-voltage side terminal of the upper arm semiconductor element 4a by a positive wiring 2. The negative terminals of the ceramic capacitor 7 and the film capacitor 8 are connected to the main circuit low-voltage side terminal of the lower arm semiconductor element 4b by a negative wiring 3.

[0017] The main circuit low voltage side terminal of the upper arm semiconductor element 4a is connected to the main circuit high voltage side terminal of the lower arm semiconductor element 4b by output wiring 6 of each phase. The positive electrode wiring 2 is connected to the positive electrode terminal of the capacitor 7 of the other phase and the main circuit high voltage side terminal of the upper arm semiconductor element 4a of the other phase. The negative electrode wiring 3 is connected to the negative electrode terminal of the capacitor 7 of the other phase and the main circuit low voltage side terminal of the lower arm semiconductor element 4b of the other phase. In this manner, a multi-phase circuit can be constructed.

[0018] The capacitor 8 is, for example, a film capacitor 8 with a large capacitance or a small ceramic capacitor 7, and by placing it in the vicinity of the upper arm semiconductor element 4a and the lower arm semiconductor element 4b, the wiring inductance of the positive wiring 2 and the negative wiring 3 can be reduced.

[0019] In the upper arm semiconductor element 4a and the lower arm semiconductor element 4b, signal terminals such as gate terminals are connected to a control circuit not shown, and are turned on or off based on a signal input from a higher-level control device such as a microcomputer, thereby outputting an AC voltage to a load such as a motor.

[0020] (Figure 2) Fig. 2(a) is an overall perspective view of the power conversion device 1, and Fig. 2(b) is an overall top view of the power conversion device 1. The multiple capacitors 8 are each connected to a positive electrode wiring 2 and a negative electrode wiring 3 provided on a wiring board 18, which is a control board. The positive electrode wiring 2 and the negative electrode wiring 3 have a DC input terminal 22, and conduct DC power input from a battery or the like to the semiconductor modules 20, 21.

[0021] When the multiple capacitors 8 are of a type with large capacitance, such as a film capacitor 8, they are arranged in a line on the side of the wiring board 18 along the direction in which the three-phase semiconductor devices of U, V, and W phases are arranged, which makes it easier to fix them to the case (not shown) of the power conversion device 1, thereby improving vibration resistance.

[0022] The upper arm semiconductor module 20 in which a semiconductor device including the above-mentioned upper arm semiconductor element 4a is mold-sealed, and the lower arm semiconductor module 21 in which a semiconductor device including the above-mentioned lower arm semiconductor element 4b is mold-sealed extend in a line from the capacitor 8 toward the output terminal 6a, thereby shortening the lengths of the positive electrode wiring 2, the negative electrode wiring 3, and the output wiring 6. This makes it easy to miniaturize the power conversion device 1. This also contributes to miniaturizing a cooler to be attached from the outside and facilitating the installation of the cooler.

[0023] (Figure 3) Fig. 3(a) is a top view showing a power converter 1 for one phase in which a plurality of semiconductor modules are connected to board wiring, and Fig. 3(b) is a cross-sectional view taken along line A-A' of Fig. 3(a), showing a configuration example of an upper arm semiconductor module 20. In the plurality of semiconductor modules 20, 21, the aforementioned semiconductor elements 4a, 4b that convert DC power to AC power are sealed by a sealing member 17.

[0024] Wiring board 18 has through holes 23 and is connected to semiconductor modules 20, 21 via through holes 23. Wiring board 18 has signal wiring 15 connected to control terminals (signal terminals) 11 via terminal connection parts 14 such as solder, and output wiring 6 which is main circuit wiring connected to main terminals 9, 10 of the upper arm semiconductor element and main terminals 12, 13 of the lower arm semiconductor element via terminal connection parts 14 such as solder. In wiring board 18, signal wiring 15 and output wiring 6 connected to upper arm semiconductor element 4a and lower arm semiconductor element 4b via terminals are on the first layer of the board.

[0025] The semiconductor elements 4a and 4b each have a plurality of signal terminals 11 and a plurality of main terminals. The semiconductor module 20 controls switching of the electrical continuity between the main terminals based on a control signal input via the signal terminal 11.

[0026] The positive electrode wiring 2, the negative electrode wiring 3, and the output wiring 6 formed on the first layer of the wiring board 18 are electrically connected to the other layers by interlayer connectors 5 formed by through-hole vias or the like. By providing a large number of interlayer connectors 5 on the wiring board 18, the cross-sectional area of ​​the current flowing in the cross-sectional direction of the wiring board 18 can be increased, thereby reducing electrical resistance and heat generation in the wiring. Furthermore, the interlayer connectors 5 improve the heat transfer in the cross-sectional direction of the wiring board 18, making it possible to suppress an increase in the wiring temperature.

[0027] (Figure 4) Fig. 4(a) is a top view illustrating the state in which signal terminals and main terminals in the semiconductor modules 20, 21 protrude to the outside from the semiconductor modules 20, 21. Fig. 4(b) is a perspective view of Fig. 4(a). Below, the terminals protruding from the semiconductor module will be described based on the upper arm semiconductor module 20. In the semiconductor module 20, the multiple signal terminals 11 and the multiple main terminals 9, 10 protrude in opposite directions from the semiconductor module 20. Furthermore, each of the multiple signal terminals 11 has a bent portion 11b between the semiconductor module 20 and the wiring board 18.

[0028] In the semiconductor module 20, the bent portion 11b has a convex portion 11c, and the convex portion 11c of the bent portion 11b of one signal terminal 11 and the convex portion 11c of the bent portion 11b of the other signal terminal 11 are formed to face each other. In other words, in the semiconductor module 20, the respective bent portions 11b are bent in directions approaching each other.

[0029] The reason for adopting such a configuration is that the rigidity of wiring board 18 is reduced by providing through hole 23 in wiring board 18. In other words, the linear expansion coefficients of semiconductor module 20 and wiring board 18 to be connected are different, and when the two are soldered together, the amount of contraction of semiconductor module 20 becomes greater than that of wiring board 18, causing a problem that the semiconductor module 20 is pulled toward the center of through hole 23. This difference in the amount of contraction between semiconductor module 20 and wiring board 18 is mitigated by the slight displacement of bent portion 11b of signal terminal 11. This makes it possible to reduce warping of wiring board 18 when semiconductor module 20 is joined.

[0030] The bent portions 11b are not bent in the height direction, but bent in the direction in which the signal terminals 11 are arranged. This can solve the problem that the bent portions 11b interfere with stacking due to the arrangement of the heat dissipation member 16 described below when joining the semiconductor module 20 and the wiring board 18, and contributes to a low profile and small size of the power conversion device 1. In addition, by bending the bent portions 11b in directions approaching each other, the creepage distance at the base of the terminals in the signal terminals 11 can be secured, and the insulation performance can be improved.

[0031] Moreover, by providing the bent portion 11b only on the signal terminal 11 side, through which a large current does not flow, instead of on the main terminals 9, 10, it is possible to avoid the increase in inductance and heat generation that would occur if the bent portion 11b were provided on the main terminals 9, 10 side through which a large current flows, and this contributes to improving the reliability of the joint. Furthermore, the signal terminal 11 is easier to change than the main terminals 9, 10, which are affected by the large current, and this contributes to facilitating design changes. Furthermore, by arranging the signal terminal 11 and the main terminals 9, 10 on the upper surface side of the semiconductor module 20, it becomes easier to connect to the wiring board 18, which contributes to reducing costs. Note that the signal terminal 11 may be formed longer within a range that does not affect performance, and the main terminals 9, 10 may be shortened accordingly.

[0032] In the semiconductor module 20, the signal terminal 11 and the main terminals 9 and 10 protrude from opposite sides to each other, thereby minimizing magnetic coupling during switching operations. In addition, the bent portion 11b is provided on the signal terminal 11 side to minimize the influence of magnetism.

[0033] From the viewpoint of increasing productivity, it is desirable that the length of the protruding portion 11c protruding from the width of the signal terminal 11 be greater than the width of the signal terminal 11. As long as the insulation distance can be ensured, the bent portions 11b may be bent in the same direction or outwardly.

[0034] (First Modification) (Figure 5) Fig. 5(a) is an explanatory diagram of the configuration of a semiconductor module showing a first modified example of an embodiment of the present invention, and Fig. 5(b) is an overall perspective view of Fig. 5(a). Features of the first modified example will be described based on an upper arm semiconductor module 20.

[0035] 1 to 4, it was necessary to create bent portion 11b and then fit it into a mold. Specifically, in the case of bent portion 11b having a bent shape in the in-plane direction of wiring substrate 18 described in FIG. 4, the bent shape needs to be formed when signal terminal 11 is ground, and there is a risk of interference between the mold for sealing member 17 and the bent shape.

[0036] However, with the shape of the bent portion 11b in the first modified example, the bent portion 11b can be formed in the signal terminal 11 after molding and sealing with the sealing member 17 in the semiconductor module 20. This improves the manufacturability of the power conversion device 1. However, the design must take into consideration the placement of the heat dissipation member 16 so as not to come into contact with the heat dissipation member 16 that is to be brought into contact with the semiconductor module 20, which will be described later.

[0037] (Second Modification) (Figure 6) FIG. 6(a) is an explanatory diagram of the configuration of a semiconductor module showing a second modified example of an embodiment of the invention, and FIG. 6(b) is an overall perspective view of FIG. 6(a). The features of the second modified example will be described based on an upper arm semiconductor module 20. In the semiconductor module 20, each bent portion 11b is L-shaped in the same direction, and fits within the size of the semiconductor module 20 in the planar direction. In this way, the bent portion 11b is made to have a simple L-shaped bent shape compared to the U-shaped bent shape described in FIG. 4 and FIG. 5, thereby improving productivity. In addition, the problem of reducing the height and size in consideration of the installation of the heat dissipation member 16 can be solved.

[0038] (Third Modification) (Figure 7) The features of the third modified example will be described based on the upper arm semiconductor module 20. Heat dissipation members 16 are provided on both sides of the semiconductor module 20 in the thickness direction, and are in contact with the semiconductor module 20. For example, a heat dissipation member 16 having a water channel therein will apply additional stress to the joint when assembled to the semiconductor module 20, but by adopting a configuration of the present invention in which a signal terminal 11 having a bent portion 11b is provided, it is possible to achieve double-sided cooling of the semiconductor module 20 while maintaining the reliability of the joint. Note that although a double-sided cooling configuration has been exemplified, single-sided cooling may also be used.

[0039] (Figure 8) Fig. 8(a) is an overall perspective view of the power converter 1 described above in Fig. 7 with heat dissipation members 16 installed on both sides, and Fig. 8(b) is an overall top view of Fig. 8(a). Heat dissipation members 16 are arranged above and below the wiring board 18. This makes it possible to cool both sides of the multiple semiconductor modules 20, 21 arranged on the wiring board 18, improving heat dissipation performance.

[0040] According to the embodiment of the present invention described above, the following advantageous effects are obtained.

[0041] (1) A power conversion device 1 including a plurality of semiconductor modules 20, 21 in which semiconductor elements for converting DC power to AC power are sealed with a sealing member 17, and a wiring board 18 having a through hole 23 and connected to the semiconductor modules 20, 21 through the through hole 23, in which the semiconductor elements 4a, 4b have a plurality of signal terminals 11 and a plurality of main terminals, the wiring board 18 has signal wiring connected to the signal terminal 11 and main circuit wiring connected to the main terminal, the semiconductor modules 20, 21 switch-control the conduction between the main terminals based on a control signal input via the signal terminal 11, the plurality of signal terminals 11 and the plurality of main terminals protrude from the semiconductor module 20 to the outside in opposite directions, and the plurality of signal terminals 11 each have a bent portion 11b at a position between the semiconductor module 20 and the wiring board 18. In this way, a power conversion device 1 can be provided that suppresses warping of the wiring board 18 during joining, reduces stress at the joint during assembly of the water channel 16, and avoids an increase in main circuit inductance.

[0042] (2) In the semiconductor modules 20 and 21, the bent portion 11b has a protruding portion 11c, and the protruding portion 11c of the bent portion 11b of one signal terminal 11 and the protruding portion 11c of the bent portion 11b of the other signal terminal 11 are formed to face each other. This can reduce warping of the wiring board 18 when the semiconductor module 20 is joined.

[0043] (3) In the semiconductor modules 20 and 21, the bent portions 11b are bent in directions toward each other, thereby ensuring a creepage distance at the base of the signal terminal 11 and improving insulation performance.

[0044] (4) Bent portion 11b is bent in the thickness direction of wiring board 18. This can improve the manufacturability of power conversion device 1.

[0045] (5) In the semiconductor modules 20 and 21, the bent portions 11b are L-shaped in the same direction and fit within the size of the semiconductor modules 20 and 21 in the planar direction. This improves productivity. Also, the problem of reducing the height and size in consideration of the installation of the heat dissipation member 16 can be solved.

[0046] (6) In the thickness direction of the semiconductor modules 20, 21, the heat dissipation members 16 are provided on both sides of the semiconductor modules 20, 21. This improves the heat dissipation performance.

[0047] The present invention is not limited to the above-described embodiment, and various modifications and other configurations can be combined without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiment, and includes those in which some of the configurations are omitted. [Explanation of symbols]

[0048] 1 Power conversion device 2 Positive Wiring 3 Negative Wiring 4. Semiconductor elements 4a Upper arm semiconductor element 4b Lower arm semiconductor element 5 Interlayer Connections 6 Output wiring 6a Output terminal 7. Ceramic Capacitors 8 Capacitors 9 Low-voltage side terminal for main circuit of upper arm semiconductor element 10 High voltage side terminal for main circuit of upper arm semiconductor element 11 Control terminal (signal terminal) 11b Bend part 11c Convex part 12 Low-voltage side terminal for main circuit of lower arm semiconductor element 13 High voltage side terminal for main circuit of lower arm semiconductor element 14 Terminal connection 15 Signal wiring 16 Heat dissipation material 16a Heat dissipation surface 17 Sealing member 18 Wiring board 20 Upper arm semiconductor module 21 Lower arm semiconductor module 22 DC input terminal 23 Through hole

Claims

1. a plurality of semiconductor modules each having a semiconductor element that converts DC power into AC power sealed with a sealing member; A power conversion device comprising: a wiring board having a through hole and connected to the semiconductor module through the through hole, the semiconductor element has a plurality of signal terminals and a plurality of main terminals; the wiring board has signal wiring connected to the signal terminal and main circuit wiring connected to the main terminal, the semiconductor module controls switching of conduction between the main terminals based on a control signal input via the signal terminal; the signal terminals and the main terminals protrude from the semiconductor module to the outside in opposite directions to each other; Each of the signal terminals has a bent portion located between the semiconductor module and the wiring board. Power conversion equipment.

2. The power conversion device according to claim 1, In the semiconductor module, the bent portion has a convex portion, The convex portion of the bent portion of one of the signal terminals and the convex portion of the bent portion of the other of the signal terminals are formed to face each other. Power conversion equipment.

3. The power conversion device according to claim 2, In the semiconductor module, the bent portions are bent in directions approaching each other. Power conversion equipment.

4. The power conversion device according to claim 1, The bent portion is bent in a thickness direction of the wiring substrate. Power conversion equipment.

5. The power conversion device according to claim 1, In the semiconductor module, each of the bent portions is L-shaped in the same direction and fits within the range of the size of the semiconductor module in a planar direction. Power conversion equipment.

6. The power conversion device according to claim 1, A heat dissipation member is provided on both sides of the semiconductor module in the thickness direction of the semiconductor module. Power conversion equipment.

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