JPH11146633A - Semiconductor device - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a semiconductor device capable of easily averaging a shared current of a unit circuit by utilizing the property of mutual inductance. A circuit for connecting at least two semiconductor elements in parallel by a connection conductor and connecting the parallel connection conductor and a power supply or a load by a connection conductor, wherein an insulating material is provided on a part of the connection conductor. Connection conductors that are closely connected in parallel with each other are arranged, and the inductance of connection conductors that are closely connected in parallel is smaller than the inductance of connection conductors that are not parallel or not closely connected, so that the effective inductance per length is smaller, and the shared current is averaged. Plan. According to the present invention, by averaging the shared current, the utilization efficiency of the semiconductor device is improved, which is effective in increasing the capacity, miniaturizing, and extending the life of the device. It is possible to easily carry out design for the purpose of realization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a semiconductor device for equalizing a shared current of semiconductor devices connected in parallel.

[0002]

2. Description of the Related Art FIG. 7 shows a configuration of a so-called three-level serial multiplex power converter in which four main circuit elements conventionally used are connected in series.

In FIG. 7, Q1 to Q4 are semiconductor elements,
1A to 1C denote unit circuits constituting one phase of the main circuit,
C and N are electrodes, and U, V and W are converter outputs.

[0004] In a power converter, when a large current flows, a single semiconductor element is used by connecting semiconductor elements in parallel because the current capacity is limited. When the semiconductor elements are connected in parallel, the parallel connection can be easily performed by using 1A to 1C surrounded by a dotted line in FIG. 7 as one unit circuit. Further, a unit circuit in which a plurality of semiconductor elements are connected in parallel is used. The unit circuit is shown in FIG.

In order to use the semiconductor elements connected in parallel efficiently, it is necessary to average the shared current. In order to average the shared current, it is necessary to equalize the characteristics of the semiconductor elements and to equalize the inductance of the connection conductor.

When parallel connection of unit circuits is considered, a configuration as shown in FIG. 9 is generally used to equalize inductance. FIG. 9 shows only the connection conductor of the electrode P in order to avoid complication of the drawing.

[0007]

In the above prior art, based on the idea of making the distances equal, the shared current of each unit circuit is averaged by the positions of the two branch points shown in FIG. However, it is difficult to equalize the inductance of the connection conductor of each unit circuit due to the influence of mutual inductance. This will be described using an equivalent circuit shown in FIG. FIG. 10 is an equivalent circuit of a conductor connected to the electrodes P and U in order to avoid complication of the drawing. Actually, a connection conductor having a similar configuration is connected to the electrodes C and N. In the inductance shown in FIG. 10, mutual inductance acts on the connection conductors arranged in parallel.

In this conventional method, the mutual inductance between the unit circuits must be equalized depending on the positions of the two branch points of each electrode. In an actual configuration, the mutual inductance between the electrode C and the electrode N must also be taken into consideration, and moving the branch point of one electrode affects the overall inductance, and causes a complex mutual inductance. Relationships matter. For this reason, in the conventional method using two branch points, it is difficult to average the shared current of the unit circuits when considering the operation modes of all the inverters.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor device which can easily average a shared current of a unit circuit by utilizing the property of mutual inductance in order to solve the above-mentioned drawbacks.

[0010]

According to the present invention, a semiconductor device according to the present invention comprises connecting at least two or more semiconductor elements, each having an anode terminal or a cathode terminal connected in parallel with a connection conductor, and connecting the parallel connection conductor to a power supply. Alternatively, in a semiconductor device which is connected to a load by a connection conductor, a part of the connection conductor is provided with a connection conductor closely in parallel via an insulating material. For this reason, the inductance of the connection conductors closely connected in parallel has a smaller effective inductance per length than the inductance of the connection conductors that are not parallel or not closely connected.
By utilizing this effect, the inductance of the connection conductors that are parallel and closely connected is compensated for by the inductance of the connection conductors that are not parallel or not closely connected, thereby averaging the inductance in the connection conductor portion and sharing the semiconductor element. The current can be equalized.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. FIG. 1 shows an embodiment of the present invention. 1 to 3 in FIG.
2 is a connection conductor, 2A to 2C are unit circuits, and Z1 to Z9 are insulating materials. Next, the reason why such a configuration of the connection conductor can achieve the averaging of the shared current of the unit circuits will be described with reference to an equivalent circuit diagram.

In the configuration shown in FIG. 1, the inductance of the connection conductor can be set in the equivalent circuit shown in FIG. FIG.
In FIG. 1, the inductance of the connection conductors 1 and 2 in FIG.
1, L2 and the inductance of the connection conductors 5, 6 are L5, L
6. The inductance of the connection conductors 9, 10 is L9, L1.
0, the inductance of the connection conductors 13, 14 is L13, L
14. The inductance of the connection conductors 17, 18 is L17,
L18, the inductance of the connection conductors 21 and 22 is L2
1, L22, the inductance of the connection conductor 25 is L25
1, L252, the inductance of the connection conductor 26 is L26
1, L262, the inductance of the connection conductor 29 is L29
1 to L293, the inductance of the connection conductor 30 is L30
1 to L303. Here, L302 = L262, L
292 = L252, L301 = L261 = L22, L2
91 = L251 = L21. However, the electrodes C and N have the same configuration as the electrodes P and U, but are omitted to prevent the drawing from becoming complicated. Hereinafter, a case where a current flows between the electrodes PU will be described as an example. In the present embodiment, description will be made with the influence of mutual inductance between unit circuits being excluded because it is small.

Here, in the connection conductors 1 to 12 in FIG. 1, the conductors connected to the same electrode have the same configuration.
That is, the inductances have the same magnitude, such as L1 = L5 = L9 and L2 = L6 = L10.

When the longitudinal inductances of the unit circuits 2A and 2B are compared, L303 on the electrode P side has a difference in inductance. However, in the present invention, L303 and L293
Has a parallel / close structure and is a three-level converter. Therefore, a reciprocating current flows through L303 and L293, and the mutual inductance acts to reduce the effective component of the inductance of L313 and L293. When comparing the inductance between the vertical electrodes using parallel closely connected conductors and the inductance of non-parallel or non-close horizontal connection conductors, the inductance per length is the This means that the inductance between the electrodes of the connection conductor is smaller. By utilizing this effect, the inductances of the unit circuits 2A and 2B can be equalized by the short horizontal connection conductors L13 and L14 which are not parallel or not close to each other than the parallel connection conductors in the vertical direction. . That is, in the unit circuit 2B, L13 and L14 are changed to L303 and L2.
It is possible to make it equal to the effective inductance of 93. Similarly, regarding the unit circuit 2C, the unit circuit 2C
L17, L18 so as to be equal to the inductance of A
Thereby, it is possible to absorb the difference between the inductances in the vertical direction, which are closely contacted in parallel.

As described above, by utilizing the inductance ratio per length of the parallel and closely connected connection conductors and the non-parallel or non-closely connected connection conductors, the difference in inductance between the parallel and closely connected connection conductors can be reduced. Alternatively, it is possible to compensate for the inductance of the connection conductor that is not closely connected, and to average the shared current of each unit circuit. According to the present invention, since the mutual inductance between the unit circuits is small, the inductance can be easily equalized. The connection conductor of the unit circuit A is designed first, and then the unit circuits B and C are connected.
By making the non-parallel or not closely connected horizontal connecting conductors equal to the inductance of the connecting conductors of the unit circuit A in total, there is an advantage that the shared current of the unit circuits can be easily averaged.

Next, the embodiment shown in FIG. 3 will be described. In FIG. 3, reference numerals 33 to 48 denote connection conductors, and Z10 to Z12.
Is an insulating material. FIG. 3 shows a configuration in which when connecting conductors are raised from the electrodes to each unit circuit, the vertical connecting conductors divided for each unit circuit in FIG. 1 are combined into one. FIG. 5 shows an electrical equivalent circuit at this time. In FIG. 5, the inductances of the connection conductors 33 and 34 are L33 and L34, the inductances of the connection conductors 37 and 38 are L37 and L38,
The inductance of the connection conductors 41, 42 is L41, L4
2. The inductance of the connection conductors 45 and 46 is L451-
L453, L461 to L463.

In order for the inductance between the electrodes PU in the unit circuit 2B to be equal to the inductance of the unit circuit 2A, an inductance corresponding to L13 and L14 shown in the above embodiment is required. This is shown in FIG.
372, L382 and L412, L422.

In order to equalize the inductance, the connection conductors in the non-parallel or non-close direction are arranged as shown in FIG. 4, and the inductance is increased by increasing the distance, and the parallel connection conductors are arranged in the vertical direction. Make up for the difference in inductance of the connection conductors.

The configuration shown in FIG. 6 can also average the shared current of the unit circuit by the same effect as in FIG. The difference between FIG. 3 and FIG. 6 is that, in order to equalize the inductance, the distance between the unit circuits A, B, and C differs in the vertical direction depending on the arrangement of the unit circuits. The equivalent circuit can be represented in the same way as in FIG. 5, and the shared current can be averaged by arranging the unit circuits with equal inductance.

The effects of the embodiment described above are not limited to the three-level power converter. It can be widely applied to multi-level power converters other than three levels. In addition, although the unit circuit has been described, this configuration method can be applied to a circuit / element using a connection conductor through which a reciprocating current flows. For example, it is also effective for parallel connection of semiconductor elements and parallel connection of capacitors in a unit circuit.

Further, in the present embodiment, the description has been made by taking three parallel connections as an example, but the present invention can be widely extended to two or more parallel connections.

[0022]

According to the semiconductor device of the present invention, anode terminals or cathode terminals of at least two or more semiconductor elements are connected in parallel by connecting conductors, respectively, and the parallel connecting conductor is connected to a power supply or a load. In a semiconductor device in which the connection conductors are connected by a connection conductor, a part of the connection conductor is provided with a parallel and closely connected connection conductor via an insulating material. For this reason, the inductance of the connection conductors closely connected in parallel has a smaller effective inductance per length than the inductance of the connection conductors that are not parallel or not closely connected. By utilizing this effect, the inductance of the connection conductors that are parallel and closely connected is compensated for by the inductance of the connection conductors that are not parallel or not closely connected, thereby averaging the inductance in the connection conductor portion and sharing the semiconductor element. Since the current is equalized and the utilization efficiency of the parallel semiconductor devices is improved, the capacity can be increased.
Effective for miniaturization.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of FIG.

FIG. 3 is a configuration diagram showing one embodiment of the present invention.

FIG. 4 is a diagram showing one configuration of a connection conductor.

FIG. 5 is an equivalent circuit diagram of FIGS. 3 and 6;

FIG. 6 is a configuration diagram showing one embodiment of the present invention.

FIG. 7 is a configuration diagram of a general three-level serial multiplex power converter.

FIG. 8 is a schematic diagram of a unit circuit.

FIG. 9 is a configuration diagram showing a configuration of a conventional example.

FIG. 10 is an equivalent circuit diagram of FIG. 9;

[Explanation of symbols]

Q1 to Q4: semiconductor elements, 1A to 1C, 2A to 2C: unit circuits, P, C, N: electrodes, U, V, W: converter outputs,
1 to 75: connection conductor, Z1 to Z15: insulating material, L1, L
2, L5, L6, L9, L10, L13, L14, L1
7, L18, L21, L22, L33, L34, L25
1, L252, L261, L262, L291-L29
3, L301 to L303, L371, L372, L38
1, L382, L411, L412, L421, L42
2, L451-L453, L461-L463, L66
1, L662, L671, L672, L681, L68
2, L691, L692, L701, L702, L71
1, L712, L721, L722, L731, L73
2, L741, L742, L751, L752 ... self-inductance.

Claims (1)

[Claims] An anode terminal or a cathode terminal of at least two or more semiconductor elements are connected in parallel by connecting conductors, respectively, and the parallel connecting conductor and a power supply or a load are connected by connecting conductors. In the semiconductor device, a part of the connection conductor has a connection conductor closely in parallel with an insulating material interposed therebetween.