JPH1075564A - Semiconductor power converter - Google Patents

Abstract

[PROBLEMS] To reduce the size of a semiconductor power conversion device,
Increase snubber effect. A stack includes a flywheel diode having a flat shape, a self-extinguishing semiconductor element, a snubber capacitor, and a cooling fin.
Are stacked in series, and these are integrated and pressurized by the pressurizing device 6. [Effect] It is possible to reduce the size of the stack.
Further, the inductance of the snubber circuit can be minimized, and the breaking capacity of the self-extinguishing element can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor power conversion device, and more particularly to a semiconductor power conversion device in which the cutoff performance is improved by devising a mounting structure of a flat self-extinguishing semiconductor snubber capacitor.

[0002]

2. Description of the Related Art In a power converter using a self-extinguishing type semiconductor element, a snubber is provided in parallel with the semiconductor element in order to reduce electric stress applied at the time of switching of the semiconductor element in addition to the semiconductor element for conversion. The capacitor and the snubber diode are connected. This circuit prevents a sharp change in the circuit current when the self-extinguishing type semiconductor element is extinguished, and this current change causes an excessive voltage to be generated in this element due to the action of the inductance distributed in the circuit. It is provided to control. To this end, it is important to minimize the inductance of the current path around the self-extinguishing element, snubber capacitor and snubber diode as much as possible. As a mounting structure to achieve this object,
Japanese Patent Application Laid-Open No. 3-82150 discloses a method of mounting a snubber diode and a snubber capacitor having a press-contact structure in parallel with an anode cooling fin and a cathode cooling fin of a flat self-extinguishing element.

[0003]

However, in the above-mentioned prior art, as the breaking capacity of the self-extinguishing type semiconductor element increases, the structure for pressing the snubber diode and the snubber capacitor having a large capacity becomes large, and mounting is difficult. There was a problem.

[0004] It is an object of the present invention to reduce the size of a semiconductor power conversion device and enhance the snubber effect.

[0005]

In order to solve the above-mentioned problems, the present invention provides a flat type snubber capacitor and a snubber diode each having a flat plate shape similar to a flat type semiconductor element and having upper and lower electrodes formed of metal flat plates. A unit having a structure and using the same stack as the self-extinguishing semiconductor device and the flywheel diode was used.

A snubber diode and a snubber capacitor are formed in the same shape as a flat element, and the snubber capacitor and the snubber diode are pressed and held by being mounted in the same stack as the self-extinguishing semiconductor element and the flywheel diode. Since the mechanism can be omitted, the stack can be made compact. In addition, since the self-extinguishing element, snubber capacitor, and snubber diode can be connected without intervening any intervening element other than the cooling fin, the inductance of the snubber circuit can be minimized, and the self-extinguishing element can be used. It is possible to increase the breaking capacity.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a structural diagram of a stack showing a first embodiment of the present invention. FIG. 2 is a circuit diagram of this stack.

In FIG. 1, a flywheel diode 2, a self-extinguishing type semiconductor element 1, a snubber capacitor 4 and a snubber diode 3 having a flat shape are stacked in series with a cooling fin 5 interposed therebetween. And pressurized by the pressurizing device 6. Thus, the flywheel diode 2 and the self-extinguishing type semiconductor device 1
Therefore, there is no need to separately prepare a press-contact and holding mechanism for the snubber capacitor 4 and the snubber diode 3 other than the press-contact and holding mechanism for the stack, and the stack can be made compact. Each semiconductor element and the arrangement of the snubber capacitors need to be stacked in the order in which they appear on a line drawn with a single stroke so as to pass through each element once in FIG. Also,
In order to minimize the inductance of the snubber circuit, the flywheel diode 2 must not be arranged between the self-extinguishing type semiconductor element 1, the snubber capacitor 4, and the snubber diode 3. As a result, the inductance of the snubber circuit can be minimized, and the breaking capacity of the self-extinguishing element can be increased. A bar 9 is a conductor for forming a loop of the snubber circuit, and a bar 8 is a conductor for forming an anti-parallel of the self-extinguishing semiconductor element 1 and the flywheel diode 2. Terminals 71 and 72 are connected to an external main circuit, and terminal 73 is connected to an energy recovery circuit of a snubber capacitor and the like.

[Embodiment 2] FIG. 3 is a structural view of a stack showing a second embodiment of the present invention. FIG. 4 is a circuit diagram of this stack.

In FIG. 3, a flywheel diode 2, a self-extinguishing type semiconductor element 1, a snubber capacitor 4, a snubber diode 3, and a snubber resistor 10 are arranged in series with a cooling fin 5 in a stack. They are stacked and pressurized by the pressurizing device 6 integrally. Each semiconductor element and the arrangement of snubber capacitors and snubber resistors need to be stacked in the order in which they appear on a line drawn with one stroke so as to pass through each element once in FIG. Further, in order to minimize the inductance of the snubber circuit, the flywheel diode 2 and the snubber resistor 10 must not be arranged between the self-extinguishing type semiconductor element 1, the snubber capacitor 4, and the snubber diode 3. A bar 9 is a conductor for forming a loop of the snubber circuit, and a bar 8 is a conductor for forming an anti-parallel of the self-extinguishing semiconductor element 1 and the flywheel diode 2. The bar 11 is a conductor for discharging the energy of the snubber capacitor 4 through the snubber resistor 10 when the self-extinguishing element 1 is fired. Terminals 71 and 72 are connected to an external main circuit.

[Embodiment 3] FIG. 5 is a structural view of a stack showing a third embodiment of the present invention. The circuit diagram of this stack is FIG. 4 as in the second embodiment.

In FIG. 5, the snubber resistor 10 in the second embodiment of FIG. 3 and the cooling fins 5 on both sides thereof are replaced by snubber resistors having a built-in cooling mechanism. If the cooling mechanism of the snubber resistor has sufficient performance to also cool adjacent elements, the water cooling fins on both sides or on one side can thus be omitted.

[0013]

According to the present invention, the snubber diode and the snubber capacitor are formed in the same shape as the flat element, and the snubber capacitor and the snubber capacitor are assembled in the same stack as the self-arc-extinguishing type semiconductor element and the flywheel diode to be pressed. Since the mechanism for pressing and holding the diodes can be omitted, the stack can be made compact. Also self-extinguishing element, snubber capacitor,
In addition, since the snubber diode can be connected without any intervening object other than the cooling fin, the inductance of the snubber circuit can be minimized, and the breaking capacity of the self-extinguishing element can be increased. .

[Brief description of the drawings]

FIG. 1 is a structural view of a stack showing a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a first embodiment of the present invention.

FIG. 3 is a structural view of a stack showing a second embodiment of the present invention.

FIG. 4 is a circuit diagram showing second and third embodiments of the present invention.

FIG. 5 is a structural view of a stack showing a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Self-extinguishing semiconductor element, 2 ... Flywheel diode, 3 ... Snubber diode, 4 ... Snubber capacitor,
5 ... cooling fins, 6 ... pressurizing device, 8, 9, 11 ... bar,
10: snubber resistor, 71, 72: main circuit terminal, 73:
Regenerative circuit terminal.

Claims (3)

[Claims] 1. A semiconductor power converter having a self-extinguishing type semiconductor element, a flywheel diode, a snubber diode, a snubber capacitor, a cooling fin, and other peripheral circuits, wherein the self-extinguishing type semiconductor element, flywheel diode, Each semiconductor element of the snubber diode has a flat shape and has a shape called a flat shape having electrodes made of a metal flat plate on its upper and lower surfaces, and the snubber capacitor has the same flat shape as the semiconductor device and has metal on its upper and lower surfaces. A semiconductor power conversion device having an electrode formed of a flat plate, wherein the semiconductor element and the snubber capacitor are stacked in series with each other via a cooling fin, and are pressure-welded to form an integrated stack. 2. A semiconductor power conversion device having a self-extinguishing type semiconductor element, a flywheel diode, a snubber diode, a snubber capacitor, a snubber resistor, a cooling fin, and other peripheral circuits. Each semiconductor element of a flywheel diode and a snubber diode has a flat plate shape, and has a flat shape having electrodes formed of metal flat plates on upper and lower surfaces thereof. The snubber capacitor has a flat plate shape similar to the semiconductor element. The upper and lower surfaces have electrodes made of a metal flat plate, and the snubber resistor has an electrode made of a metal flat plate on its upper and lower surfaces in a flat plate shape similar to a semiconductor element. The snubber capacitor and the snubber resistor are stacked in series with each other with cooling fins interposed therebetween and pressed into contact with each other. A semiconductor power conversion device characterized by comprising a stacked stack. 3. A semiconductor power converter having a self-extinguishing semiconductor device, a flywheel diode, a snubber diode, a snubber capacitor, a snubber resistor, a cooling fin, and other peripheral circuits. Each semiconductor element of a flywheel diode and a snubber diode has a flat plate shape, and has a flat shape having electrodes formed of metal flat plates on upper and lower surfaces thereof. The snubber capacitor has a flat plate shape similar to the semiconductor element. The upper and lower surfaces have electrodes made of a metal flat plate, and the snubber resistor has a flat plate shape similar to that of a semiconductor element and includes the function of a cooling fin, and the upper and lower surfaces have electrodes made of a metal flat plate. The semiconductor element, the snubber capacitor, and the snubber resistor are directly connected to each other via cooling fins. A semiconductor power conversion device characterized by comprising an integrated stack which is stacked in rows and pressed into contact.