JP2021089969A - Power semiconductor device - Google Patents

Abstract

To provide a power semiconductor device with the built-in switching element and smoothing capacitor, each of which is required to be cooled via a common heat radiating plate and arranged in the same plane, thus in which the high cost is caused since an element breakdown voltage must be increased due to a long wiring path between the switching element and the smoothing capacitor, the increased inductance, and the increase surge voltage, and furthermore, which is not suitable for miniaturization since an area of a heat dissipation plate of the semiconductor device, that is, the area where the semiconductor device is installed is increased.SOLUTION: A power semiconductor device includes: a plurality of switching elements; a smoothing capacitor in which a plurality of electrolytic capacitors connected in parallel; a circuit board on which the plurality of electrolytic capacitors is mounted; a conductive member having a positive electrode and a negative electrode on which a plurality of switching elements is mounted; and a housing. The plurality of switching elements and the circuit boards are connected by the conductive member and stored inside the housing.SELECTED DRAWING: Figure 1

Description

The present application relates to a semiconductor device for electric power.

Conventionally, in a power conversion device, a power semiconductor device and a smoothing capacitor are connected outside the power semiconductor device, but a wiring path between a switching element of the power semiconductor device and a smoothing capacitor is established. Since it is long, the inductance becomes large, and the surge voltage becomes large, the withstand voltage of the device must be increased, resulting in high cost. In addition, it is necessary to increase the capacitance of the capacitor in order to suppress the ripple voltage of the DC power supply due to the increase in inductance, which causes the increase in the size of the capacitor for smoothing and the size of the power conversion device. It was.

Further, it is common to use an electrolytic capacitor such as a cylinder as a smoothing capacitor having a large capacitance, and it is difficult to effectively use the space, which hinders the miniaturization of the inverter.

In order to solve this problem, a capacitor for smoothing is housed in the housing of the power semiconductor device, the wiring inductance is reduced, the capacitor is miniaturized, and the entire power conversion device is miniaturized. Has been proposed (Patent Document 1).

In Patent Document 1, a plurality of phases having P electrodes and N electrodes of a power semiconductor device, a switching element and a diode, and a flat plate-shaped or block-shaped capacitor connected to each phase of the plurality of phases are included. A configuration is shown in which one or a plurality of the above capacitors are connected to the P electrode and the N electrode of each of the phases, which are built in one housing.

Japanese Unexamined Patent Publication No. 2001-258267

However, since the power semiconductor device shown in Patent Document 1 has a structure in which the heat generated by the switching element and the smoothing capacitor is transferred to the common heat dissipation plate and cooled, the switching element and the smoothing capacitor are placed on the same plane. Need to be placed. As a result, the wiring path between the switching element and the smoothing capacitor is long, the inductance becomes large, and the surge voltage becomes large, so the withstand voltage of the element must be increased, and the problem of high cost has not been solved. .. Further, the area of the heat radiating plate of the power semiconductor device, that is, the area where the power semiconductor device is installed becomes large, and it is not suitable for miniaturization.

The present application discloses a technique for solving the above-mentioned problems, and an object of the present application is to provide a power semiconductor device suitable for miniaturization in order to reduce heat generation of a smoothing capacitor.

The power semiconductor device disclosed in the present application includes a plurality of switching elements, a smoothing capacitor in which a plurality of electrolytic capacitors are connected in parallel, a circuit board on which the plurality of the electrolytic capacitors are mounted, and a plurality of switching elements. A conductive member having a positive electrode and a negative electrode, and a housing are provided, and the plurality of switching elements and the circuit board are connected to the conductive member and housed in the housing. Is.

According to the power semiconductor device disclosed in the present application, the volume of a capacitor having the same capacity can be reduced by using a plurality of electrolytic capacitors having a large capacity per unit volume, and one by using a plurality of electrolytic capacitors. By dispersing the ripple current and reducing self-heating, it is possible to reduce the size without the need for cooling.

It is a block diagram which shows the structure of the semiconductor device for electric power by Embodiment 1. FIG. It is a block diagram which shows the member arrangement by Embodiment 1. FIG. It is a circuit diagram of the semiconductor device for electric power according to Embodiment 1. It is a pattern diagram of the printed wiring board according to Embodiment 1. It is a block diagram which shows the structure of the semiconductor device for electric power by Embodiment 2. It is a block diagram which shows the member arrangement by Embodiment 2. FIG. It is a block diagram which shows the structure of the semiconductor device for electric power by Embodiment 3. FIG. It is a block diagram which shows the member arrangement by Embodiment 3. FIG. It is a block diagram which shows the structure of the semiconductor device for electric power by Embodiment 4. FIG. It is a block diagram which shows the member arrangement by Embodiment 4. FIG. It is a block diagram which shows the structure of the semiconductor device for electric power according to Embodiment 5. It is a block diagram which shows the member arrangement by Embodiment 5. It is a block diagram which shows the structure of the semiconductor device for electric power by Embodiment 6. It is a block diagram which shows the member arrangement by Embodiment 6.

Embodiment 1
FIG. 1 is a block diagram showing a schematic configuration of a power semiconductor device according to the first embodiment, and FIG. 1A is a plan view, a side sectional view of FIG. 1B, and a bottom sectional view of FIG. 1C.
The power semiconductor device 1 contains a conductive member 50 on which a switching element 20 is mounted, a printed wiring board 40 on which an electrolytic capacitor 30 is mounted, and an insulating heat radiating member 60 inside a housing 10. However, because of the external connection, a part of the conductive member 50 protrudes from the housing 10.

The switching element 20 is classified into an upper switching element 20a and a lower switching element 20b. Eight electrolytic capacitors 30 are connected in parallel to the printed wiring board 40 (hereinafter, an example of eight parallel connections will be described). However, this is just one example, and the number of parallels is not limited to eight. The conductive member 50 can be classified into a P terminal 50a, an N terminal 50b, and an output terminal 50c.

FIG. 2 is a configuration diagram showing a member arrangement in the power semiconductor device 1 according to the first embodiment, FIG. 2A is a plan view, FIG. 2B is a side sectional view, and FIG. 2C is a bottom sectional view.
FIG. 2 is a diagram in which the electrolytic capacitor 30 and the printed wiring board 40 are removed from FIG. The P terminal 50a and the upper switching element 20a are connected, and the N terminal 50b and the lower switching element 20b are connected. Further, the output terminal 50c is connected to both the upper switching element 20a and the lower switching element 20b. In the electrical circuit diagram, it can be represented as shown in FIG. Here, the configuration for one arm (one phase) is shown.

A resin having good insulation and heat dissipation is mainly used for the housing 10. Examples thereof include, but are not limited to, phenolic or epoxy resin materials.
The switching element 20 shown as the upper switching element 20a and the lower switching element 20b is, for example, a MOSFET (Metal-Oxide-Semiconductor-Field-Effect-) as shown in the circuit diagram of the power semiconductor device according to the first embodiment of FIG. Transistor) and so on. Similarly, there is no problem even if it is composed of a Si-based IGBT (Insulated-Gate-Bipolar-Transistor) and a diode, or a SiC-based or GaN-based switching element.

The electrolytic capacitor 30 plays the role of a smoothing capacitor. As the type, an aluminum electrolytic capacitor with a large capacity per unit volume is assumed. In addition, a hybrid electrolytic capacitor in which an electrolytic solution having a large allowable ripple current and a long life and a solid polymer are mixed may be used. By connecting multiple electrolytic capacitors with a large allowable ripple current in parallel and using them as smoothing capacitors, the ripple current caused by the ripple voltage can be dispersed, and the heat generated by each ripple current can be reduced. There is no need to actively cool the electrolytic capacitor. The total required capacitance is assumed to be, for example, several tens of μF to several thousand μF. As a mounting method on the printed wiring board 40, mounting by through holes or surface mounting can be considered, but any of them may be used if necessary. Further, the plurality of switching elements 20 and the printed wiring board 40 are connected to the conductive member 50 to form an integral structure and are housed in the housing 10. Although size restrictions are assumed when storing in the housing 10, the radial dimension and the height dimension can be adjusted even with the same capacity, so that the degree of freedom in layout design is high and the required capacity is secured. Is possible. By arranging general-purpose small aluminum electrolytic capacitors in a staggered pattern, it is possible to reduce wasted space as much as possible, and it is possible to obtain the effect of miniaturization rather than arranging them in an aligned manner.

The printed wiring board 40 is composed of a general base material such as a glass composite substrate (CEM3) or a glass cloth base material epoxy resin (FR4). The arrangement of the electrode patterns is various, such as one-sided or double-sided, and a multi-layered one having an inner layer, and any of them may be used as needed. The electrode pattern diagram of the printed wiring board 40 according to the first embodiment of FIG. 4 shows a pattern arrangement on one side. The + electrode pattern and the-electrode pattern are arranged according to the + to-electrodes of the electrolytic capacitor 30.
That is, it is a flat plate in which the positive electrode which is the + electrode pattern and the negative electrode which is the-electrode pattern are arranged in parallel, the anode terminals of a plurality of electrolytic capacitors are connected to the positive electrode, and the cathode terminal of the electrolytic capacitor is , The printed wiring board or a circuit board in place of the printed wiring board is set so as to be connected to the negative electrode across the space between the positive electrode and the negative electrode.

The width and thickness of the + electrode pattern that becomes the P terminal 50a and the − electrode pattern that becomes the N terminal 50b of the conductive member 50 can be set according to the flowing current. For example, the width is 10 mm and the thickness is 70 μm. If the cross-sectional area of the current path is small on one side (= large electrical resistance value), take measures such as increasing the required cross-sectional area by using a double-sided or multi-layer board.

The conductive member 50 is basically a copper material, but may be an aluminum material or another alloy. As the shape, a lead shape (square shape, round shape) or a flat plate shape is often used. The shape is not limited to this as long as it is conductive. A solder connection is mainly used for connecting the conductive member 50, the switching element 20, and the printed wiring board 40. In addition, welding or a conductive adhesive may be used. Other means may be used as long as they can be electrically connected.

As the heat insulating member 60, a resin having good heat insulating properties and heat dissipation is mainly used. For example, urethane type, epoxy type, acrylic type and the like can be mentioned, but the present invention is not limited to this. Appropriate materials can be selected according to the specification environment and materials used.

As shown in FIGS. 1A, 1B and 1C, the positional relationship between the printed wiring board 40 on which the electrolytic capacitor 30 is mounted and the switching element 20 is as shown in the order of the conductive member 50, the switching element 20, the printed wiring board 40, and the electrolytic capacitor 30. , The printed wiring board 40 is stacked and arranged in the upward or vertical direction with respect to the main surface of the printed wiring board 40.

As a result, the connection path length of the switching element 20, the conductive member 50, and the electrolytic capacitor, which are electrically connected inside the power semiconductor device 1, can be minimized. That is, since it is possible to suppress an increase in parasitic interactance caused by wiring, it is possible to suppress an increase in surge voltage during switching, and it is possible to prevent destruction of the switching element 20 due to surge voltage.

Since the area can be minimized without expanding the area in the plane direction other than the switching element 20 and the conductive member 50, the installation area of the power semiconductor device 1 does not become larger than necessary.
Among the existing types of capacitors, by using an electrolytic capacitor having a large capacity per unit volume, the volume can be reduced in the same capacity, so that the size can be reduced.

In addition, although electrolytic capacitors with enhanced earthquake resistance are available by manufacturers, they have the disadvantages of increased size and cost. On the other hand, since the electrolytic capacitor 30 is arranged inside the power semiconductor device 1 and the insulating heat radiating member 60 is filled, the same effect as that in which the earthquake resistance is enhanced can be expected. Naturally, the effects of miniaturization and cost reduction can also be obtained.

Embodiment 2.
The second embodiment will be described only in terms of differences from the first embodiment, and duplicated description will be omitted.
5A and 5B are block diagrams showing a schematic configuration of a power semiconductor device according to a second embodiment, FIG. 5A is a plan view, FIG. 5B is a side sectional view, and FIG. 5C is a bottom sectional view.
The positions of the P terminal 50a and the N terminal 50b protruding from the housing 10 of the power semiconductor device 1 are located in the vertical direction of FIG. The P terminal 50a protrudes to the upper part, and the N terminal 50b protrudes to the lower part. The positional relationship between the P terminal 50a, the N terminal 50b, and the switching element 20 is shown in the layout diagram of the members in the power semiconductor device 1 according to the second embodiment of FIG.

Such arrangement of the P terminal 50a and the N terminal 50b is also possible, and the degree of freedom in layout design of the product using the power semiconductor device 1 can be improved. In some cases, the connection path length of the switching element 20, the conductive member 50, and the electrolytic capacitor, which are electrically connected inside the power semiconductor device 1, can be shortened as compared with the first embodiment. That is, since it is possible to suppress an increase in parasitic interactance caused by wiring, it is possible to suppress an increase in surge voltage during switching, and it is possible to prevent destruction of the switching element 20 due to surge voltage.

The arrangement of the members in the power semiconductor device 1 according to the second embodiment is shown below. 6A and 6B are configuration views showing a member arrangement according to the third embodiment, FIG. 6A is a plan view, FIG. 6B is a side sectional view, and FIG. 6C is a bottom sectional view.
FIG. 6 is a diagram in which the electrolytic capacitor 30 and the printed wiring board 40 are removed from FIG. The P terminal 50a and the upper switching element 20a are connected, and the N terminal 50b and the lower switching element 20b are connected. Further, the output terminal 50c is connected to both the upper switching element 20a and the lower switching element 20b. In the electrical circuit diagram, it can be represented as shown in FIG. 3, and has a configuration for one arm (one phase).

Embodiment 3.
7A and 7B are block diagrams showing a schematic configuration of a power semiconductor device according to a third embodiment, FIG. 7A is a plan view, FIG. 7B is a side sectional view, and FIG. 7C is a bottom sectional view.
A printed wiring board 40 having an electrolytic capacitor 30 mounted on the switching element 20 is arranged in the upward direction. That is, the upper switching element 20a is mounted on the P terminal 50a and the output terminal 50c of the conductive member 50, and the lower switching element 20b is mounted on the N terminal 50b and the output terminal 50c of the conductive member 50. A plurality of electrolytic capacitors 30 are arranged in the upward direction with respect to the positions of the upper switching element 20a and the lower switching element 20b. The positional relationship between the P terminal 50a, the N terminal 50b, and the switching element 20 is shown in FIGS. 8A, 8B, and 8C.

Compared with the first embodiment or the second embodiment, the installation area of the power semiconductor device on the product is larger, but on the contrary, there is an advantage that the height dimension can be reduced. For example, the height dimension can be reduced by increasing the radial dimension without changing the capacitance of the electrolytic capacitor 30. Further, when the power semiconductor device 1 is installed in another product, the large area cools not only the switching element 20 but also the heat generated by the P terminal 50a, the N terminal 50b, the electrolytic capacitor 30, and the printed wiring board 40. The effect of improving the efficiency of the operation can be obtained. As shown in FIGS. 7a and 7b, when a plurality of electrolytic capacitors 30 are arranged in the upward direction with respect to the positions of the upper switching element 20a and the lower switching element 20b, they should not be spread in the lateral direction as much as possible. It is desirable to place them close together.

The arrangement of the members in the power semiconductor device 1 according to the third embodiment is shown below. 8A and 8B are configuration views showing a member arrangement according to the third embodiment, FIG. 8A is a plan view, FIG. 8B is a side sectional view, and FIG. 8C is a bottom sectional view.
8A, 8B, and 8C are views obtained by removing the electrolytic capacitor 30 and the printed wiring board 40 from FIGS. 7A, 7B, and 7C. The P terminal 50a and the upper switching element 20a are connected, and the N terminal 50b and the lower switching element 20b are connected. Further, the output terminal 50c is connected to both the upper switching element 20a and the lower switching element 20b. The electrical circuit diagram can be represented as shown in FIG. 3, and has a configuration for one arm (one phase).

Embodiment 4.
The fourth embodiment will be described only in terms of differences from the third embodiment, and duplicated description will be omitted.
9A and 9B are block diagrams showing a schematic configuration of a power semiconductor device according to a fourth embodiment, FIG. 9A is a plan view, FIG. 9B is a side sectional view, and FIG. 9C is a bottom sectional view.
The positions of the P terminal 50a and the N terminal 50b protruding from the housing 10 of the power semiconductor device 1 are located in the vertical direction of FIGS. 9A and 9C. The P terminal 50a protrudes to the upper part, and the N terminal 50b protrudes to the lower part. As shown in FIG. 9A, the upper switching element 20a and the lower switching element 20b are provided in different regions in the same surface direction as the printed wiring board 40 provided with the electrolytic capacitor 30. That is, they are arranged side by side.
The arrangement of the P terminal 50a, the N terminal 50b, the upper switching element 20a, and the lower switching element 20b in the power semiconductor device 1 according to the third embodiment is shown below. 10A and 10B are configuration views showing a member arrangement according to the fourth embodiment, FIG. 10A is a plan view, FIG. 10B is a side sectional view, and FIG. 10C is a bottom sectional view.

Such arrangement of the P terminal 50a and the N terminal 50b is possible, and the degree of freedom in layout design of the product using the power semiconductor device 1 can be improved. In some cases, the connection path length of the switching element 20, the conductive member 50, and the electrolytic capacitor, which are electrically connected inside the power semiconductor device 1, can be shortened as compared with the third embodiment. That is, since it is possible to suppress an increase in parasitic interactance caused by wiring, it is possible to suppress an increase in surge voltage during switching, and it is possible to prevent destruction of the switching element 20 due to surge voltage.

Embodiment 5.
The fifth embodiment will be described only in terms of differences from the third embodiment, and duplicated description will be omitted.
11A and 11B are block diagrams showing a schematic configuration of a power semiconductor device according to a fifth embodiment, FIG. 11A is a plan view, FIG. 11B is a side sectional view, and FIG. 11C is a bottom sectional view.
The printed wiring board 40 on which the electrolytic capacitor 30 is mounted is divided into two parts and arranged on both sides of the switching element 20. The arrangement of the P terminal 50a, the N terminal 50b, the upper switching element 20a, and the lower switching element 20b is shown below. 12A and 12B are configuration views showing the arrangement of members according to the fifth embodiment, FIG. 12A is a plan view, FIG. 12B is a side sectional view, and FIG. 12C is a bottom sectional view. As shown in FIG. 12A, the positional relationship between the upper switching element 20a and the lower switching element 20b and the printed wiring board 40 is the same as in the fourth embodiment. The electrolytic capacitor 30 is provided in a different region in the same surface direction as the printed wiring board 40 provided. That is, they are arranged side by side.

The area where the power semiconductor device 1 is installed in the product is the same as that in the third and fourth embodiments, but when the position of the electrolytic capacitor 30 is changed, it functions as an X capacitor, so that it absorbs noise due to switching and outputs. It is possible to prevent noise from being generated on the side. However, since it is limited to the range of the frequency characteristics of the electrolytic capacitor 30, it is necessary to select parts according to the frequency band of noise.

Embodiment 6.
The sixth embodiment will be described only in terms of differences from the fifth embodiment, and duplicated description will be omitted.
13 is a block diagram showing the configuration of the power semiconductor device according to the sixth embodiment, FIG. 13A is a plan view, FIG. 13B is a side sectional view, and FIG. 13C is a bottom sectional view.
As shown in FIGS. 13A and 13B, the P terminal 50a and the N terminal 50b protruding from the housing 10 of the power semiconductor device 1 are positioned so as to protrude in the vertical direction of the power semiconductor device 1. The P terminal 50a protrudes to the upper part, and the N terminal 50b protrudes to the lower part. The arrangement of the P terminal 50a, the N terminal 50b, the upper switching element 20a, and the lower switching element 20b is shown below. 14 is a configuration diagram showing a member arrangement according to the sixth embodiment, FIG. 14A is a plan view, FIG. 14B is a side sectional view, and FIG. 14C is a bottom sectional view.

Such arrangement of the P terminal 50a and the N terminal 50b is possible, and the degree of freedom in layout design of the product using the power semiconductor device 1 can be improved. In some cases, the connection path length of the switching element 20, the conductive member 50, and the electrolytic capacitor, which are electrically connected inside the power semiconductor device 1, can be shortened as compared with the fifth embodiment. That is, since it is possible to suppress an increase in parasitic interactance caused by wiring, it is possible to suppress an increase in surge voltage during switching, and it is possible to prevent destruction of the switching element 20 due to surge voltage.

Although the configurations of the electric circuit for one phase are shown in the above-described first to sixth embodiments, it is possible to treat them as multiple phases by using a plurality of them. For example, in the case of three phases (U phase, V phase, W phase), the P terminal and the N terminal may be connected in parallel using the three, and the output terminals may be assigned to the U phase, the V phase, and the W phase. ..

In the first to sixth embodiments, it is described that the printed wiring board is used as the substrate on which the electrolytic capacitor is mounted. However, the printed wiring board is an example and is not particular about it. In consideration of thermal properties, another circuit board having good conductivity may be used.

Although the present application describes various exemplary embodiments, the various features, embodiments, and functions described in one or more embodiments are limited to the application of the particular embodiment. Rather, it can be applied to embodiments alone or in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 Power semiconductor device, 10 housings, 20 switching elements, 20a upper switching elements, 20b lower switching elements, 30 electrolytic capacitors, 40 printed wiring boards, 50 conductive members, 50a P terminals, 50b N terminals, 50c output terminals, 60 Insulated heat dissipation member

Claims (4)

A plurality of switching elements, a smoothing capacitor in which a plurality of electrolytic capacitors are connected in parallel, a circuit board on which the plurality of the electrolytic capacitors are mounted, a conductive member having a positive electrode and a negative electrode on which the plurality of the switching elements are mounted, A power semiconductor device comprising the above and a housing, wherein the plurality of switching elements and the circuit board are connected to the conductive member and housed in the housing. The power semiconductor device according to claim 1, wherein the circuit board on which the electrolytic capacitor is mounted is arranged above the plurality of switching elements. The power supply according to claim 1 or 2, wherein the circuit board on which the plurality of electrolytic capacitors are mounted is arranged so as to overlap the conductive member on which the plurality of switching elements are mounted. Semiconductor device. The power semiconductor device according to any one of claims 1 to 3, wherein a part or all of the housing is filled with an insulating heat radiating member.

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