JPH03132066A - Transistor module for power conversion device - Google Patents

Abstract

PURPOSE:To enable load to be applied on each element to be connected in parallel uniformly by performing wiring so that the length of a connection conductor, between each semiconductor element which is connected in parallel and an external terminal, is nearly constant. CONSTITUTION:Connection conductors 31A-34A and 31B-34B are fixed onto a container bottom part 11 through an insulation printed-circuit board 2. The electrode of each semiconductor chip is connected to each connection conductor. Namely, one of the conductors connecting the emitter terminal 61 to respective transistors Tr41A-41D is connected to a terminal 61 from the middle point between the points at which the emitters of both Tr41A and 41B are connected with the conductor 31A, while the other is connected to the terminal 61 from the middle point between points at which the emitters of transistors 41C, 41D are connected with the conductor 31B. In this case, these connection conductors should be of the same length. Thus, inductance from the terminal 61 to each transistor due to the connection conductor is nearly equal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transistor module used in a power conversion device, which is composed of transistors and a snubber circuit consisting of an asymmetric element and a capacitor for protecting the transistors. .

[Conventional technology]

Transistor modules used in power conversion devices are
Only transistor or in parallel with transistor or 1
It consists of a diode that is connected in a column and allows current to flow in the opposite direction or the same direction as the transistor, and these transistors and diodes are fixed on the same substrate and are housed in one container, and a An external terminal and a terminal for driving the transistor were provided on the outer periphery of the container. Furthermore, in order to prevent the device from being damaged due to the surge voltage generated by the stray inductance of the circuit being applied to the device when turning off the transistor or reverse recovery of the diode, Japanese Patent Application No. 1-8311
From No. 1, a method has been proposed in which an asymmetric element with a small forward voltage drop and a large reverse voltage drop between the terminals of a transistor, such as a snubber circuit consisting of a series circuit of a constant voltage diode and a capacitor, is connected in parallel. . FIG. 9 shows this circuit. In such a transistor module,
The collector of the transistor 21 and the anode of the constant voltage diode n were connected with a conductor, and a capacitor was connected between the cathode of the constant voltage diode n and the emitter of the transistor 21. However, such a configuration has the following problems.

1) The constant voltage diode generates heat, so it must be dissipated. However, since snubber circuits are generally attached to the wiring conductor provided on the top of the transistor device, heat cannot be dissipated sufficiently, and a large prong is required. Requires constant voltage diode confectionery of size.

(2) In order to solve the above problem, when constant voltage diode elements are scattered on the same cooling body as the transistor confectionery, the distance between the terminals of the transistor elements becomes longer, and another wiring conductor is required for connection. Is required. Furthermore, the wiring between the capacitor and the terminal of the transistor becomes long, and the inductance of these wirings reduces the surge voltage absorption effect of the snubber circuit.

In contrast, transistor modules shown in FIGS. 6 to 8 have been proposed in Application No. 1-161339. FIG. 6 is a layout diagram of each element and component in the above proposal.
33 and 34 are fixed. On the connecting conductor pad, the transistor chip 41 is fixed by the collector electrode on the lower surface, the diode chip 142 is fixed by the cathode electrode on the lower surface, and the constant voltage diode chip core is fixed by the anode electrode on the lower surface.

The emitter electrode on the top surface of the transistor candy 41 is connected to the connection conductor 31, the pace electrode is connected to the connection conductor, the anode electrode on the top surface of the diode chip "42 is connected to the connection conductor 31, and the can base on the top surface of the constant voltage diode chip 43 is connected to the connection conductor 31. The U-domain electrodes are connected to the connecting conductors by metal wires 5. FIG. 7 shows the external appearance of a transistor module container in which the side wall 12 and the top cover 13 are assembled on the bottom plate 11 shown in FIG. 6. , external terminals, that is, an emitter (E) terminal 61 and a collector (C) terminal 62 are provided on the upper lid 13.
．． A pace (B) terminal 63 and a cathode (K) terminal are provided. The emitter terminal 61 is connected to the connecting conductor 31 and the collector terminal 62 is connected to the connected conductor through a not-shown upstream portion. The base terminal port is connected to the connecting conductor, and the cathode terminal port is connected to the connecting conductor. A snubber capacitor 7 is connected between the emitter terminal 61 and the cathode terminal -. FIG. 8 shows its equivalent circuit. The circuit is the same as the above-mentioned FIG. 9.

The output of this transistor module is determined by the capacitance of the semiconductor elements used, but since there is a limit to the capacitance of these semiconductor elements, these semiconductor elements are required to increase the output of the transistor module (Ila
Connect l number of devices in parallel.

[Problem to be solved by the invention]

In the transistor module for the power converter device mentioned above, the required number of semiconductor elements are connected in parallel to increase the output. In this case, each semiconductor element connected in parallel and the transistor are connected in parallel. Because the positional relationship with the external terminals of the module is different, the inductance of the wiring between them is different, and for this reason, in the case of transistors, there is a difference in the ON and OFF times between elements connected in parallel, and the rated capacity of that element There is a problem that it cannot be used fully. Voltage regulating diodes also have the same problem of not being able to be used up to their rated capacity because the load is not applied evenly due to this inductance shift.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transistor module in which the inductances of wirings between semiconductor elements and external terminals connected in parallel are equal.

[Means to solve the problem]

In order to solve the above-mentioned problems, a transistor element substrate and an asymmetric element substrate with forward/reverse current/voltage characteristics housed in one container according to the present invention are arranged on one surface of each element substrate on one connecting conductor on the bottom plate of the container. The electrodes on the side are fixed with the electrodes facing down, and the electrodes on the other side are each connected to different connection conductors via the metal a-rim, and are also connected to the different connection conductors here and each connected to the outside of the container through the top lid of the container. In a transistor module for a power conversion device in which external terminals are connected to each other via connecting conductive wires, the transistor element substrates and the asymmetric element substrates are each connected in parallel, and the different connections The connecting wires between the conductor and the external terminal should each have approximately the same length.

[Effect]

The inductance of a wire is basically proportional to the length of the wire. In the transistor module of the present invention, the lengths of the connecting wires between the semiconductor elements connected in parallel and the external terminals are approximately equal to each other, so that the inductances thereof are approximately equal. In addition, since the positional relationship between each semiconductor element and the external terminal connected in parallel is different, the connecting conductor may become loose in some cases, but in this case, it should be fixed with the fastener shown in Figure i3. So no problem will occur.

〔Example〕

FIG. 1 is a wiring diagram of each semiconductor element and external terminal connected in parallel in one embodiment of the present invention, and FIG. 2 is a plan view showing the arrangement of each semiconductor element and parts in the embodiment of FIG. 1. be. In this example, there are 4 transistors and 4 diodes.
This shows the case where two constant voltage diodes are connected in parallel.

In FIG. 2, connecting conductors 31A and 3 made of copper are placed on the bottom part 11 of the container made of steel, for example, through an insulating substrate 2.
2A, 33A, 34A and 31B, 32B
, 33B, and 34B are fixed. On the connection conductor 32A are transistor chips 41A and 41B.
are fixed by the collector electrodes on the bottom surface, the diode chips 42A and 42B are fixed by the cathode electrodes on the bottom surface, and the constant voltage diode chip 43A is fixed by the anode electrode on the bottom surface. Although detailed illustrations are omitted for clarity, the emitter and rear electrodes on the upper surfaces of the transistor tips 41A and 41B are connected to the connecting conductor 31A, the base electrodes are connected to the connecting conductor 33A, and the upper surfaces of the diode chips 428 and 42B are connected to the connecting conductor 31A. The anode electrode is connected to the connecting conductor 31A, and the cathode electrode on the upper surface of the constant voltage diode chip 43A is connected to the connecting conductor 34A by thin metal wires 5, respectively. Furthermore, on the connecting conductor 32B, transistor chips 41C and 41D are connected to the constant voltage diode chip 4 by means of collector electrodes on the lower surface, and diode chips 42C and 42D are connected to the constant voltage diode chip 4 through the cathode electrodes on the lower surface, respectively.
3B is fixed by the anode electrode on the lower surface. Similar to the above, for the sake of clarity, detailed illustrations have been omitted for clarity, but the emitter electrodes on the top surfaces of the transistor chips 41C and 41D are connected to the connection conductor 31B, the space electrodes are connected to the connection conductor 33B, and the top surfaces of the diode tips 42C and 42D. The anode electrode of the constant voltage diode chip 43B is connected to the connecting conductor 31B, and the cathode electrode on the upper surface of the constant voltage diode chip 43B is connected to the connecting conductor 34B.
and are connected by gold wires 51, respectively.

Figure 1 is a wiring diagram of the connecting conductors and external terminals shown in Figure 1g2.
That is, an emitter (E) terminal, a collector (C) terminal, a base (B) terminal, a cathode (K) terminal, and an emitter (E) terminal are attached to the upper lid of the transistor module at the positions shown.

The thick dotted lines are the connection conductors 8 between the external terminals and each connection conductor.
It is. The '1 pole of each semiconductor chip is connected to each connection conductor. That is, among the connecting conductors that connect the emitter terminal 61 and each of the transistors 41A, 41B, 41C, and 41D, one is connected to the connecting conductor 31A to which the emitters of the transistors 41A and 41B are connected. The emitter terminal 61 is connected from approximately the middle of the connected points, and the other one is the transistor 41c.

The connecting conductor 31B to which the emitter of the transistor 41D is connected is connected to the emitter terminal 61 from approximately the middle of the point where the emitters of both transistors are connected to each other. In this case, these connecting conductors are of equal length. In this way, the inductances due to the connecting wires from the emitter terminal 61 to each transistor become approximately equal. In a similar manner, the collector terminal 62 is connected between the connecting conductors 32A and 32B connected to the collector, the base terminal is connected between the connecting conductors 33A and 33B connected to the base, and the cathode terminal -
is the connection 4 body 34 to which the cathode of the asymmetric element is connected.
Connecting wires 8 of equal length between A and 34B
It is connected with collector terminal 62, base terminal 63,
As can be seen in the connecting conductor of the cathode terminal, due to the positional relationship between the terminal and each connecting conductor, if the lengths of the two connecting conductors are made equal, in some cases they may become loose in the middle. In this case, as shown in Figure 1. Hold the connecting conductor as shown in the P section. Details of the P portion are shown in FIG. 3, and the connecting conductor is held by a fastener 8 as shown in the figure.

In addition, in this example, the base CB),
A control emitter (E) terminal 67 is provided adjacent to the terminal 63 and is tied within the container. This makes wiring the control strings outside the transistor module easier.

FIG. 4 is a plan view of a transistor module in which a side wall and an upper case are assembled on the container bottom plate 11 shown in FIG. 62, base CB) terminal 63% cathode (IO terminal 64, control emitter (E) terminal 67 positions correspond to those in FIG. 1. Snubber circuit capacitor 7 has cathode terminal - and emitter terminal 61 Make a connection between.

FIG. 5 is a circuit diagram of the transistor module thus obtained.

〔Effect of the invention〕

According to the present invention, in the power converter module,
When connecting each semiconductor element in parallel, the length of the connecting wire between the external terminal and each semiconductor element is made equal, and the inductance of this wiring is made equal, so that each element connected in parallel can be connected in parallel. The load is now applied evenly, and each element can now be fully used up to its rated capacity. This results in a reduction of 5 to 8% compared to conventional transistor modules.
Output increased.

[Brief explanation of the drawing]

1 is a wiring diagram of semiconductor elements and external terminals connected in parallel in an embodiment of the present invention, FIG. 2 is a plan view showing the arrangement of semiconductor elements and components in the embodiment of FIG. 1, Figure 3 is an enlarged detailed view of section P in Figure 1, and Figure 4 is a detailed view of section P in Figure 1.
FIG. 5 is a plan view of the transistor module for a power converter according to the present invention assembled on the bottom plate of the container shown in FIG. Figure 6 is a perspective view showing the arrangement of elements and parts on the bottom plate of a container in a conventional transistor module for power conversion equipment, and Figure 7 is a diagram of the conventional transistor module for power conversion equipment assembled on the bottom plate of the container shown in Figure @6. A perspective view of a transistor module, FIG. 8 is a conventional power conversion f shown in FIG.
c. Equivalent circuit diagram of a medical transistor module. FIG. 9 is a circuit diagram of a snubber circuit shown in Japanese Patent Application No. 1-8311. 41A, 41B, 41C, 41D... Transistor, 43A, 43B, 43C, 43D... Constant voltage diode, 61... Emitter (E) 4 children (external terminal), 62... Collector CC) terminal ( External terminal ω...Base CB) 12ia child (external terminal),
-...Cathode (K) terminal (external terminal), χ Figure 5, i Figure 5 1 Figure M

Claims (1)

[Claims] 1) A transistor element substrate and an asymmetric element substrate with forward/reverse current/voltage characteristics housed in one container are fixed onto one connecting conductor on the bottom plate of the container with the electrode on one side of each element substrate facing down, and the other The electrodes on the surface side are each connected to different connection conductors via thin metal wires, and further connected to these different connection conductors,
In a transistor module for a power conversion device, the transistor element substrate and the asymmetric element substrate are each connected in parallel to each other in a transistor module for a power conversion device, in which external terminals each drawn out from the container through a top lid of the container are connected via a connecting conductor. A transistor module for a power conversion device, characterized in that the connecting conductors between the different connecting conductors and the external terminals have substantially the same length.