Power conversion device

Abstract

To reduce component cost of a power module.SOLUTION: On one face of a printed circuit board (10), a power module (20) is mounted by a plurality of connection terminals (211a, 211b, 212 and 213). On the other face of the printed circuit board (10), a surge suppression circuit (40) is disposed in such a manner that at least a part of the surge suppression circuit (40) is overlapped with at least one of an inner region of a polygon (P), which connects connection positions (CP) of the plurality of connection terminals (211a, 211b, 212 and 213) in the printed circuit board (10) by the shortest passage, and a package (210) in a thickness direction of the printed circuit board (10).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a power conversion device including a package having at least one leg composed of switch elements of an upper arm and a lower arm, and a plurality of connection terminals.

Background Art

[0002] Patent Document 1 discloses a semiconductor device including a package incorporating a MOSFET and a power module having a bus bar connected to the MOSFET. In this semiconductor device, a surge suppression circuit is disposed on the package. Further, a through hole is formed in the package, the bus bar is passed through the through hole, and is electrically connected to the surge suppression circuit. In Patent Document 1, with such a configuration, the path between the power module and the surge suppression circuit is shortened, and the inductance of the path is reduced.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, since it is necessary to adopt a special configuration in which the bus bar is passed through the through hole of the package, the component cost of the power module increases.

[0005] An object of the present disclosure is to reduce the component cost of a power module.

Means for Solving the Problems

[0006] A first aspect of the present disclosure provides a power conversion device including a package (210) incorporating at least one leg (24) composed of switch elements (22) of an upper arm and a lower arm, and a plurality of connection terminals (211a, 211b, 212, 213), wherein on one surface, there is a printed circuit board (10) on which the power module (20) is mounted by the plurality of connection terminals (211a, 211b, 212, 213), and on the other surface of the printed circuit board (10), there is further provided a surge suppression circuit (40) for suppressing a surge voltage applied to the switch element (22), and at least a part of the surge suppression circuit (40) overlaps in the thickness direction of the printed circuit board (10) with at least one of an inner region of a polygon (P) that shortest-connects connection points (CP) of the plurality of connection terminals (211a, 211b, 212, 213) on the printed circuit board (10) and the package (210).

[0007] In the first aspect, since at least a part of the surge suppression circuit (40) is provided so as to overlap in the thickness direction of the printed circuit board (10) with at least one of an inner region of a polygon (P) that shortest-connects connection points (CP) of the plurality of connection terminals (211a, 211b, 212, 213) on the printed circuit board (10) and the package (210), the path between the power module (20) and the surge suppression circuit (40) can be shortened, and the inductance of the path can be reduced.

[0008] Also, since the power module (20) is mounted on one surface of the printed circuit board (10) and the surge suppression circuit (40) is disposed on the other surface of the printed circuit board (10), it is not necessary to adopt a special configuration in which a bus bar penetrates through a through hole of the package as in Patent Document 1, so that the component cost of the power module (20) can be reduced.

[0009] A second aspect of the present disclosure is characterized in that, in the first aspect, the surge suppression circuit (40) includes a capacitor (41) disposed on the printed circuit board (10) by surface mounting.

[0010] In the second aspect, compared with the case where the capacitor (41) is disposed on the printed circuit board (10) by through-hole mounting, the parasitic inductance of the capacitor (41) can be reduced. Therefore, the surge voltage applied to each switching element (22) at the time of turn-off can be suppressed.

[0011] A third aspect of the present disclosure is that, in the first or second aspect, the package (210) further incorporates a control unit (23) for controlling the on / off of the switching element (22), and the plurality of connection terminals (211a, 211b, 212, 213) include high-potential-side and low-potential-side connection terminals (211a, 211b) connected to both ends of the leg (24), and a plurality of control connection terminals (212) connected to the control unit (23). A first line segment (L1) that shortest connects the connection points (CP) of the plurality of control connection terminals (212) and a second line segment (L2) that shortest connects the connection points (CP) of the high-potential-side and low-potential-side connection terminals (211a, 211b) do not intersect, and the surge suppression circuit (40) is arranged closer to the second line segment (L2) than the first line segment (L1).

[0012] In the third aspect, compared with the case where the surge suppression circuit (40) is arranged closer to the first line segment (L1), the path between the leg (24) and the surge suppression circuit (40) can be shortened, and the wiring inductance of the path can be reduced. Therefore, the surge voltage applied to each switching element (22) at the time of turn-off can be suppressed.

[0013] According to a fourth aspect of the present disclosure, in any one of the first to third aspects, the plurality of connection terminals (211a, 211b, 212, 213) include connection terminals (211a, 211b) on the high potential side and the low potential side connected to both ends of the leg (24). On one or the other surface of the printed circuit board (10), a shunt resistor (50) electrically connected to the low potential side connection terminal (211b) is disposed near the connection point (CP) of the low potential side connection terminal (211b). The surge suppression circuit (40) is disposed closer to the connection point (CP) of the high potential side connection terminal (211a) than to the connection point (CP) of the low potential side connection terminal (211b).

[0014] In the fourth aspect, compared with the case where the surge suppression circuit (40) is disposed closer to the connection point (CP) of the low potential side connection terminal (211b), the influence of the heat of the shunt resistor (50) on the surge suppression circuit (40) can be suppressed.

[0015] According to a fifth aspect of the present disclosure, in any one of the first to fourth aspects, the at least one switching element (22) is characterized by being composed of a wide bandgap semiconductor.

[0016] In the fifth aspect, the switching frequency of the switching element (22) can be increased. When increasing the switching frequency, since it is necessary to increase the switching speed of each switching element (22), the surge voltage applied to each switching element (22) at turn-off increases. However, as described above, the path between the power module (20) and the surge suppression circuit (40) can be shortened and the inductance of the path can be reduced, so that the surge voltage can be suppressed.

[0017] According to a sixth aspect of the present disclosure, in any one of the first to fifth aspects, at least the leg (24) is built in the package (210) of the power module (20) in a state of being sealed with resin (R).

[0018] In the sixth aspect, the leg (24) can be protected from dust, water, and scratches.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses.

[0021] (Embodiment) FIGS. 1 and 2 show a power conversion device (1) according to an embodiment of the present disclosure. This power conversion device (1) includes a printed circuit board (10), a power module (20), a surge suppression circuit (40), a shunt resistor (50), and a heat sink (60).

[0022] The printed circuit board (10) is made of resin.

[0023] The power module (20) has a resin package (210) and a plurality of connection terminals (211a, 211b, 212, 213). The power module (20) is mounted on one surface of the printed circuit board (10) by the plurality of connection terminals (211a, 211b, 212, 213). These plurality of connection terminals (211a, 211b, 212, 213) are lead terminals and are connected to the printed circuit board (10) by being inserted into the insertion holes (11) of the printed circuit board (10) and soldered.

[0024] The package (210) is rectangular in plan view. In the package (210), six switching elements (22) and two ICs (Integrated Circuits) (231, 232) that constitute a control unit (23) for controlling the on / off of the six switching elements (22) are built in a state of being sealed with resin (R). The resin (R) is formed throughout in the package (210) in a direction along the board surface of the printed circuit board (10).

[0025] The six switching elements (22) constitute the inverter circuit (21) shown in FIG. 3. The inverter circuit (21) constitutes an active filter circuit. The six switching elements (22) are composed of wide bandgap semiconductors. Note that, among the six switching elements (22), only some of the switching elements (22) may be composed of wide bandgap semiconductors. The six switching elements (22) constitute three legs (24) composed of upper arm and lower arm switching elements (22). The connection points of the upper arm and lower arm switching elements (22) in the three legs (24) are connected to a three-phase AC power supply (2). A filter (3) and an AC reactor (4) are connected in order from the three-phase AC power supply (2) side between the three-phase AC power supply (2) and the connection points of the upper arm and lower arm switching elements (22) in the three legs (24). The filter (3) has a filter reactor (3a) connected in series with the AC reactor (4) and a capacitor (3b) connected between the filter reactor (3a) and the AC reactor (4) and provided between each phase.

[0026] The control unit (23) is a microcomputer.

[0027] The plurality of connection terminals (211a, 211b, 212, 213) are provided at intervals along the mutually opposing long sides of the package (210). The plurality of connection terminals (211a, 211b, 212, 213) include a high-potential-side connection terminal (211a) and a low-potential-side connection terminal (211b) connected to both ends of the three legs (24), a plurality of control connection terminals (212) connected to the control unit (23), and other connection terminals (213). The high-potential-side connection terminal (211a), the low-potential-side connection terminal (211b), and the other connection terminals (213) are provided along one long side of the package (210), and the control connection terminals (212) are provided along the other long side of the package (210). Therefore, a first line segment (L1) that shortest-connects the connection points (CP) of the plurality of control connection terminals (212) and a second line segment (L2) that shortest-connects the connection points (CP) of the high-potential-side and low-potential-side connection terminals (211a, 211b) do not intersect. In the present embodiment, the connection points (CP) of the connection terminals (211a, 211b, 212, 213) are the positions of the insertion holes (11) into which the connection terminals (211a, 211b, 212, 213) are inserted.

[0028] The surge suppression circuit (40) is disposed on the other surface of the printed circuit board (10) (the surface opposite to the power module (20)). The entire surge suppression circuit (40) overlaps at least one of the inner region of the polygon (P) that shortest-connects the connection points (CP) of the plurality of connection terminals (211a, 211b, 212, 213) on the printed circuit board (10) and the package (210) in the thickness direction of the printed circuit board (10). The polygon (P) that shortest-connects the connection points (CP) of the plurality of connection terminals (211a, 211b, 212, 213) is substantially trapezoidal. The surge suppression circuit (40) is disposed closer to the second line segment (L2) than the first line segment (L1). Also, the surge suppression circuit (40) is disposed closer to the connection point (CP) of the high-potential-side connection terminal (211a) than the connection point (CP) of the low-potential-side connection terminal (211b) on the printed circuit board (10). The surge suppression circuit (40) is composed of the surge suppression capacitor (41) shown in FIG. 3 disposed on the printed circuit board (10) by surface mounting. One end of the surge suppression capacitor (41) is connected to one end of the three legs (24) (the high-potential-side connection terminal (211a)). Also, a smoothing capacitor (70) which is an electrolytic capacitor is connected between both ends of the surge suppression capacitor (41). Also, a discharge resistor (80) is connected between both ends of this smoothing capacitor (70). The surge suppression circuit (40) suppresses the surge voltage applied to the six switching elements (22).

[0029] The shunt resistor (50) is disposed near the connection point (CP) of the low-potential-side connection terminal (211b) on one surface of the printed circuit board (10) (the surface on the power module (20) side). The shunt resistor (50) is disposed near the low-potential-side connection terminal (211b) to such an extent that the wiring inductance between the shunt resistor (50) and the connection point (CP) of the low-potential-side connection terminal (211b) on the printed circuit board (10) becomes 3 nH or less. As shown in FIG. 3, one end of the shunt resistor (50) is electrically connected to the other end of the three legs (24) (the low-potential-side connection terminal (211b)). The other end of the shunt resistor (50) is electrically connected to the other end of the surge suppression capacitor (41).

[0030] The heat sink (60) is in contact with the package of the power module (20) from the opposite side of the printed circuit board (10).

[0031] Therefore, according to the present embodiment, at least a part of the surge suppression circuit (40) is provided so as to overlap at least one of the inner region of the polygon (P) that connects the connection points (CP) of the plurality of connection terminals (211a, 211b, 212, 213) on the printed circuit board (10) in the shortest way and the package (210) in the thickness direction of the printed circuit board (10). Thus, the path between the power module (20) and the surge suppression circuit (40) can be shortened, and the inductance of the path can be reduced. Therefore, the surge voltage applied to each switching element (22) of the power module (20) at the time of turn-off can be suppressed.

[0032] Also, since the power module (20) is mounted on one surface of the printed circuit board (10) and the surge suppression circuit (40) is disposed on the other surface of the printed circuit board (10), it is not necessary to adopt a special configuration in which a bus bar penetrates through the through holes of the package as in Patent Document 1 for the power module (20). Therefore, an off-the-shelf product can be used as the power module (20) instead of a custom-made product, and the component cost of the power module (20) can be reduced.

[0033] Also, since the surge suppression circuit (40) is disposed in the region surrounded by the connection points (CP) of the plurality of connection terminals (211a, 211b, 212, 213) of the power module (20) on the printed circuit board (10), the adverse effects of the distortion and vibration of the printed circuit board (10) on the surge suppression circuit (40) can be suppressed. Therefore, the reliability of the surge suppression circuit (40) can be enhanced.

[0034] In addition, since the surge suppression capacitor (41) of the surge suppression circuit (40) is disposed on the printed circuit board (10) by surface mounting, the parasitic inductance of the surge suppression capacitor (41) can be made smaller than in the case of disposing it by through-hole mounting. Therefore, the surge voltage applied to each switching element (22) at turn-off can be suppressed.

[0035] In addition, since the surge suppression circuit (40) is disposed closer to the second line segment (L2) that shortest-connects the connection points (CP) of the high-potential-side and low-potential-side connection terminals (211a, 211b) than to the first line segment (L1) that shortest-connects the connection points (CP) of the plurality of control connection terminals (212), the path between the three legs (24) and the surge suppression circuit (40) can be shortened compared to the case of disposing it closer to the first line segment (L1), and the wiring inductance of the path can be made smaller. Therefore, the surge voltage applied to each switching element (22) at turn-off can be suppressed.

[0036] In addition, since the surge suppression circuit (40) is disposed closer to the connection point (CP) of the high-potential-side connection terminal (211a) than to the connection point (CP) of the low-potential-side connection terminal (211b), the influence of the heat of the shunt resistor (50) on the surge suppression circuit (40) can be suppressed compared to the case of disposing it closer to the connection point (CP) of the low-potential-side connection terminal (211b) near the shunt resistor (50).

[0037] In addition, since the six switching elements (22) are composed of wide-bandgap semiconductors, the switching frequency of the switching elements (22) can be increased. When increasing the switching frequency, since it is necessary to increase the switching speed of each switching element (22), the surge voltage applied to each switching element (22) at turn-off becomes high. However, as described above, the path between the power module (20) and the surge suppression circuit (40) can be shortened and the inductance of the path can be made smaller, so that the surge voltage can be suppressed.

[0038] In addition, in the package (210) of the power module (20), six switching elements (22), that is, three legs (24), are built in a state of being sealed with resin (R), so that the three legs (24) can be protected from dust, water, and damage.

[0039] (Modification Example 1 of the Embodiment) In the power conversion device (1) according to Modification Example 1 of the embodiment of the present disclosure, as shown in FIG. 4, capacitors (42) and resistors (43) for surge countermeasures are connected in parallel to each of the four switching elements (22). Four sets of capacitors (42) and resistors (43) for surge countermeasures constitute a surge suppression circuit (40). Each set of capacitors (42) and resistors (43) for surge countermeasures are connected in series with each other in order from the side of the high-potential connection terminal (211a). In FIG. 4, the illustration of two sets of capacitors (42) and resistors (43) for surge countermeasures is omitted.

[0040] Other configurations are the same as those in the above embodiment, so the same reference numerals are given to the same configurations and the detailed description thereof is omitted.

[0041] (Modification Example 2 of the Embodiment) In the power conversion device (1) according to Modification Example 2 of the embodiment of the present disclosure, as shown in FIG. 5, each set of capacitors (42) and resistors (43) for surge countermeasures connected in parallel with the switching elements (22) of the lower arm are connected in order from the side of the low-potential connection terminal (211b). In addition, a diode (44) is connected in parallel to each resistor (43) for surge countermeasures with its cathode facing the low-potential connection terminal (211b) side. The diode (44) is connected in series with the capacitor (42) for surge countermeasures. In FIG. 5, the illustration of two sets of capacitors (42) and resistors (43) and diodes (44) for surge countermeasures is omitted.

[0042] Other configurations are the same as those in Modification Example 1 of the above embodiment, so the same reference numerals are given to the same configurations and the detailed description thereof is omitted.

[0043] (Modification Example 3 of the Embodiment) In the power conversion device (1) according to Modification 3 of the embodiment of the present disclosure, as shown in FIG. 6, a surge countermeasure resistor (43) on the upper arm side is connected between the connection point of the surge countermeasure capacitor (42) and the diode (44) on the upper arm side and the low-potential side connection terminal (211b). Further, a surge countermeasure resistor (43) on the lower arm side is connected between the connection point of the surge countermeasure capacitor (42) and the diode (44) on the lower arm side and the high-potential side connection terminal (211a).

[0044] Since other configurations are the same as those in Modification 2 of the above embodiment, the same reference numerals are given to the same configurations and the detailed description thereof is omitted.

[0045] In the above embodiment and Modifications 1 to 3 thereof, an inverter circuit (21) having three legs (24) is incorporated in the package (210) of the power module (20). Instead, a full-bridge circuit having only two legs (24) or a totem-pole circuit having only one leg (24) may be incorporated.

[0046] Also, in the above embodiment and Modifications 1 to 3 thereof, the entire surge suppression circuit (40) is overlapped with at least one of the inner region of the polygon (P) and the package (210) in the thickness direction of the printed circuit board (10). However, only a part of the surge suppression circuit (40) may be overlapped with at least one of the inner region of the polygon (P) and the package (210) in the thickness direction of the printed circuit board (10).

[0047] Also, in the above embodiment and Modifications 1 to 3 thereof, a plurality of connection terminals (211a, 211b, 212, 213) are used as lead terminals, but they may be surface-mounting terminals or press-fit terminals connected to the printed circuit board (10) without using solder.

[0048] Further, in the above-described embodiment and its modification examples 1 to 3, the shunt resistor (50) is disposed near the connection point (CP) of the low-potential side connection terminal (211b) on one surface of the printed circuit board (10) (the surface on the power module (20) side), but it may be disposed near the connection point (CP) of the low-potential side connection terminal (211b) on the other surface of the printed circuit board (10) (the surface opposite to the power module (20)).

[0049] Further, in the above-described embodiment and its modification examples 1 to 3, the six switch elements (22) are constituted by wide bandgap semiconductors, but they may be constituted by silicon semiconductors.

[0050] Further, in the above-described embodiment and its modification examples 1 to 3, the present invention is applied when the polygon (P) that connects the connection points (CP) of the plurality of connection terminals (211a, 211b, 212, 213) of the power module (20) in the shortest way is substantially trapezoidal, but the present invention can also be applied when the polygon (P) has a shape other than a quadrilateral, such as the shape shown in FIG. 7.

[0051] As described above, the embodiments have been described, but it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Further, the above embodiments and modification examples may be appropriately combined or replaced as long as the functions of the object of the present disclosure are not impaired.

Industrial Applicability

[0052] The present disclosure is useful as a power conversion device including a package having at least one leg constituted by switch elements of an upper arm and a lower arm, and a plurality of connection terminals.

Explanation of Reference Numerals

[0053] 1 Power conversion device 10 Printed circuit board 20 Power module 22 Switch element 24 Leg 40 Surge suppression circuit 41 Surge suppression capacitor 50 Shunt resistor 210 Package 211a, 211b, 212, 213 Connection terminals CP Connection point L1 First line segment L2 Second line segment P Polygon R Resin

Claims

1. A power conversion device comprising a package (210) incorporating at least one leg (24) composed of switch elements (22) of an upper arm and a lower arm, and a plurality of connection terminals (211a, 211b, 212, 213), wherein on one surface, there is a printed circuit board (10) on which the power module (20) is mounted by the plurality of connection terminals (211a, 211b, 212, 213), and it further includes a plurality of capacitors (42) connected in parallel to each of the switch elements (22) of the upper arm and the lower arm, mounted on the other surface of the printed circuit board (10), and a surge suppression circuit (40) for suppressing a surge voltage applied to the switch elements (22), and at least a part of the surge suppression circuit (40) overlaps in the thickness direction of the printed circuit board (10) with the inner region of a polygon (P) that shortest-connects connection points (CP) of the plurality of connection terminals (211a, 211b, 212, 213) on the printed circuit board (10), the plurality of connection terminals (211a, 211b, 212, 213) are connected to the printed circuit board (10) by being inserted into insertion holes (11) of the printed circuit board (10) and soldered, and is characterized by the power conversion device.

2. In the power conversion device according to Claim 1, the plurality of connection terminals (211a, 211b, 212, 213) include a plurality of connection terminals (211a, 211b, 213) provided at intervals along one side of the package (210), and a plurality of connection terminals (212) provided at intervals along a side of the package (210) facing the one side, and is characterized by the power conversion device.

3. In the power conversion device according to Claim 1, the entire surge suppression circuit (40) overlaps in the thickness direction of the printed circuit board (10) with at least one of the inner region of a polygon (P) that shortest-connects connection points (CP) of the plurality of connection terminals (211a, 211b, 212, 213) on the printed circuit board (10) and the package (210), and is characterized by the power conversion device.

4. In the power conversion device according to Claim 1, the package (210) further incorporates a control unit (23) for controlling on / off of the switch element (22). The plurality of connection terminals (211a, 211b, 212, 213) include a high-potential-side and a low-potential-side connection terminal (211a, 211b) connected to both ends of the leg (24), and a plurality of control connection terminals (212) connected to the control unit (23). A first line segment (L1) that shortest-connects the connection points (CP) of the plurality of control connection terminals (212) and a second line segment (L2) that shortest-connects the connection points (CP) of the high-potential-side and low-potential-side connection terminals (211a, 211b) do not intersect, and The surge suppression circuit (40) is arranged closer to the second line segment (L2) than the first line segment (L1). A power conversion device characterized by this.

5. In the power conversion device according to claim 1, The plurality of connection terminals (211a, 211b, 212, 213) include a high-potential-side and a low-potential-side connection terminal (211a, 211b) connected to both ends of the leg (24). On one or the other surface of the printed circuit board (10), a shunt resistor (50) electrically connected to the low-potential-side connection terminal (211b) is disposed near the connection point (CP) of the low-potential-side connection terminal (211b). The surge suppression circuit (40) is arranged closer to the connection point (CP) of the high-potential-side connection terminal (211a) than the connection point (CP) of the low-potential-side connection terminal (211b). A power conversion device characterized by this.

6. In the power conversion device according to claim 1, The at least one switch element (22) is composed of a wide-bandgap semiconductor. A power conversion device characterized by this.

7. In the power conversion device according to claim 1, In the package (210) of the power module (20), at least the leg (24) is built in a state of being sealed with resin (R). A power conversion device characterized by this.

8. In the power conversion device according to claim 1, A resistor (43) is connected in parallel to each switch element (22) and in series with the capacitor (42). A power conversion device characterized by this.

9. In the power conversion device according to claim 1, A power conversion device, characterized in that a resistor (43) is connected between a capacitor (42) connected in parallel with a switch element (22) of the upper arm and the connection terminal (211b) on the low potential side, and between a capacitor (42) connected in parallel with a switch element (22) of the lower arm and the connection terminal (211a) on the high potential side.

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