JPH02130954A - Inverse-blocking transistor module - Google Patents

Abstract

PURPOSE:To prevent overcurrent breakdown due to ununiform current by arranging anode main terminals, emitter main terminals and base terminals symmetrically to each other on the outer surface of an insulating container. CONSTITUTION:A reverse-blocking transistor module comprises a pair of transistor-diode units connected in parallel and consisting of a transistor Tr1 and a diode FRD1 and of a transistor Tr2 and a diode FRD2, respectively. The diodes FRD1 and FRD2 are connected in series to the transistor units Tr1 and Tr2, respectively, to bear inverse dielectric strength. A pair of positive main terminals A1 and A2 and a pair of negative main terminals E1 and E2 are arranged symmetrically so that main current are extracted under the same conditions from the two internal transistor-diode units. Further, a base terminal (b) and an auxiliary emitter terminal (e) are also arranged symmetrically on the outer surface of an insulating container. Accordingly, the wiring inductance can be uniformed or decreased and the overcurrent breakdown due to ununiform current can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a reverse blocking transistor module, and particularly provides a reverse blocking transistor module suitable for constructing a high power converter.

[Conventional technology]

Conventionally, when a current capacity of several hundred amperes or more is desired as a high power converter using transistors, the current capacity is often satisfied by connecting a large number of transistors and diodes in parallel as an aggregate. For example, 100
By arranging four transistor chips and diode chips each with a current capacity of A in parallel, a current capacity of up to 400 A can be obtained.

[Problem to be solved by the invention]

However, as the number of transistor chips in parallel increases, the problem gradually becomes more apparent that chips whose distance from the position of the terminal for connection to an external circuit to the electrode on the chip surface is far are greater than those which are closer. As a result, there is a problem in that current flows more easily in a chip located at a low inductance position than in a chip located at a high inductance position, increasing the risk of current concentration leading to overcurrent damage.

In view of the above, the present invention provides a highly reliable reverse-blocking transistor module that is less likely to cause overcurrent damage due to non-uniform current flow when multiple transistor chips are connected in parallel to achieve a large current capacity. The purpose is to provide.

[Means to solve the problem]

In order to achieve such an objective, the reverse blocking transistor module of the present invention has a plurality of transistor chips and a plurality of diode chips connected in series to the collectors of these transistors, which are fixed onto a common metal substrate via an insulating plate. The diode chip has two main anode terminals, and the transistor chip has two main emitter terminals and a base terminal. In a device sealed in an insulating container together with an auxiliary emitter terminal having connection points provided and wired at equal positions on the emitter terminal board, each of the anode main terminal, each emitter main terminal and base terminal, and the auxiliary emitter terminal They are arranged symmetrically to each other on the outer surface of the insulating container.

[Effect]

When constructing a large-capacity reverse-blocking transistor module, in order to equalize the current to multiple transistors and diode units, first arrange two transistor/diode units symmetrically with each other, each consisting of the same number of transistors and diodes installed in parallel. do. To explain with the previous example,
Each transistor/diode unit has a current capacity of 400A, and the two transistor/diode units collectively have a current capacity of 800A. here,
In order to accurately match the conditions of both transistor units, main currents taken out from each transistor and diode are provided symmetrically for each transistor/diode unit. In addition, the (auxiliary) emitter terminal that pairs with the base terminal to receive and receive the base signal is not taken out from the negative main terminal (main emitter terminal) mentioned above, but taken out independently from closer to the transistor unit. Should.

Therefore, it is desirable that the wiring position of the auxiliary emitter be near each transistor unit and that the wiring length to the auxiliary emitter terminal be uniform.

In this way, the base current of each transistor becomes uniform, and variations in switching characteristics are also reduced.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail using FIGS. 1 to 3. The same reference numerals assigned in common to each drawing indicate parts having the same function.

FIG. 1 shows an outline drawing showing the arrangement of external connection terminals of the present invention, FIG. 2(a) is a top view showing the internal structure with the resin case of FIG. 1 removed, and FIG. FIG. FIG. 3 is an equivalent circuit diagram showing the internal wiring of the reverse blocking transistor module of the present invention shown in FIGS. 1 and 2. FIG.

As shown in FIG. 3, this reverse blocking transistor module includes a transistor Tr, a diode FR,
It consists of a parallel connection of two transistors/diodes, D1 and transistor T2.diode FRD2, and each transistor Tr, , as shown in FIG.
Tr, and diode FRDI.

The FRDs 2 are formed by different semiconductor chips.

Further, as shown in FIG. 3, each transistor ``r-Tr2'' is composed of a Darlington coupling having a width of three halls.
Trot to Tr23 constitute a second transistor unit Tr. Each transistor unit Tr, , Tr, has a diode FRDI.
and FRD2 are connected in series to bear the reverse withstand voltage. These transistors Tr.

As shown in FIG. 2, the Tr and the diodes FRDI and FR02 each consist of, for example, a set of four transistor chips and two diode chips (connected in parallel).

In FIGS. 1 to 3, A1 and A2 are a pair of positive main terminals, and El and E2 are negative main terminals. 1 of these
The main terminals of the pair are configured in a symmetrical shape so as to draw main current from the two internal transistor/diode units under the same conditions.

b is a base terminal, e is an auxiliary emitter terminal for signal input/output, and bl and b2 are terminals for parallel connection of modineers. In addition, wiring from the internal main emitter conductor to the auxiliary emitter terminal of the transistor module is done using copper bars or lead wires, but as shown in Figure 4, 12 wiring inductances occur.If this wiring inductance is different for each transistor, switching will occur. Since variations in characteristics become large, it is important to have the shortest wiring distance and to make the wiring uniform for each transistor. In this embodiment, the wiring inductance can be made the same by wiring each transistor unit at an even length, and the inductance per transistor can be reduced by reducing the number of wirings.

〔Effect of the invention〕

According to the present invention, in a reverse-blocking transistor module having a large current capacity, the arrangement conditions of a plurality of transistor chips or transistor units constituting this module are made symmetrical, and the wiring method to the auxiliary emitter terminal is changed to the above-mentioned transistor chips. By wiring with a uniform length, the wiring inductance can be equalized or reduced, and variations in switching characteristics of each transistor can be reduced.

Further, two of these reverse blocking transistor modules are used in parallel. Furthermore, even in the case of large-capacity power converters, 1
By attaching a snubber circuit or the like at the same location as the one, the same suppressing effect as with one can be easily obtained.

The figure is an internal equivalent circuit diagram of the present invention, and FIG. 4 is an equivalent circuit diagram showing wiring inductance.

A,,A2 ・Anode (positive) terminal, El, El
Emitter (negative) terminal, b-base terminal, e auxiliary emitter terminal, 'rrl+ 7r2. , , , , ) per transistor, FRD 1°FRD2 per diode.

Ward 1 No. figure No. figure No. figure

Claims (1)

[Claims] 1) A plurality of transistor chips and a plurality of diode chips connected in series to the collectors of these transistors are fixed on a common metal substrate via an insulating plate, and an anode main terminal is assembled into two from the diode chips;
Two main emitter terminals and a base terminal are vertically raised from the transistor chip, and connection points are provided and wired at positions on the emitter terminal board that are equally spaced from each transistor chip. and an auxiliary emitter terminal enclosed in an insulating container together with an auxiliary emitter terminal, characterized in that each of the anode main terminals, each emitter main terminal and base terminal, and the auxiliary emitter terminal are arranged symmetrically to each other on the outer surface of the insulating container. Reverse blocking transistor module.