JP3421544B2 - Semiconductor module - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates <br/> the semiconductor module in which a semiconductor element for a plurality of power are connected in parallel internally.

[0002]

2. Description of the Related Art A large-capacity power semiconductor module has a plurality of power semiconductor elements connected in parallel in the module. Regarding the IGBT as an example of the semiconductor element,
2000V500A High Power IGBT Module, A.Tanaka et.a
The description can be seen in l, ISPSD'95 Hitachi, etc.

FIG. 7 shows a power conversion device using an IGBT module. An example is shown in which four IGBTs are arranged in parallel in the module. In the figure, 1 is a DC voltage source, 2
Is an IGBT module, 3 is a load, 4 is a gate drive circuit, 5 is a gate resistance, 6A to 6D are IGBTs, 7 is a collector terminal, 8 is an emitter terminal, 9 is a gate terminal, 10
Is a signal emitter terminal.

Although not shown, each IGBT has a G
An input capacitance exists between the terminal and the E terminal. Each of the IGBTs 6A to 6D can increase or decrease the current IC that can flow in the collector by the voltage VGE between the G terminal and the E terminal. This IC-VGE characteristic is shown in an IGBT data book (for example, Toshiba IGBT data book 1996). Here, VGE for a specific IC is called a threshold value. FIG. 7 operates as follows.

When the gate drive circuit 4 outputs -15V, the gate terminal 9 and the signal emitter terminal 10 are provided.
During this period, −15V is applied and the IGBT is turned off. When the IGBT is turned on from the off state, the output of the gate drive circuit is set to + 15V. At this time, a current flows through the gate resistance, and G of the IGBTs 6A to 6D not shown is
Charge the input capacitance between the E terminals. As a result, each IGBT
The voltage between the GE terminals of 6A to 6D gradually increases. Then, when the voltage between the GE terminals of each IGBT exceeds the threshold value, the IGBT is turned on.

When the IGBT is turned off from the on state,
The output of the gate drive circuit is set to -15V. At this time, similarly, a current flows through the gate resistance, and the IGBTs 6A to 6A are
The voltage between the GE terminals of D gradually drops, and when this voltage falls below the threshold value, the IGBT is turned off.

FIG. 8 shows the structure of a pressure contact type IGBT module incorporating a plurality of IGBT chips. For the pressure contact type IGBT, for example, 2.5kV / 1kA Po
wer Pack (Flat Reverse Conducting IGBT), Yoshikawa et al. In the figure, 101 is an emitter post, 102 is a collector post, 103 is an IGBT chip, 104 is a Mo substrate,
Reference numeral 105 is a contact terminal, and 106 is a positioning guide. Although each IGBT chip 103 has a gate terminal, it is omitted in the figure. In this case, if the emitter post 101 also serves as an emitter terminal and a signal emitter terminal and the collector post 102 is replaced with a collector terminal, the operation is the same as that of the IGBT module 2 of FIG.

[0008]

[SUMMARY OF THE INVENTION However, in the conventional semiconductor module, when there are variations in the threshold of the semiconductor elements connected in parallel, a problem that variations in the collector current of each semiconductor element Occurs. For example, in the configuration of FIG. 7, when the threshold of a semiconductor element is lower than the other, GE voltage at turn-on is in the raised,
This semiconductor element is turned on first, and the entire current flows through this semiconductor element. Further, even at turn-off, there occurs a problem that elements other than this semiconductor element are turned off first while the voltage between GEs is decreasing.
As described above, if the thresholds vary, the load on the semiconductor element having a low threshold increases, and the reliability decreases.

In view of the above-mentioned problems, the present invention, therefore, provides a parallel connection of semiconductor elements having different thresholds.
And an object thereof is to <br/> provide a semiconductor module capable of improving the current balance at the time of transition.

[0010]

In order to achieve the above object, the invention according to claim 1 provides a plurality of semiconductors connected in parallel.
Body element and the emitter side of the semiconductor element connected in series
First inductor means and the first inductor
A plurality of first inductance means among
Second inductance connected in series to the parallel connection point of the stage
Means and said parallel connection of said second inductance means
A signal emitter terminal connected to the opposite side of the point;
Opposite side of the parallel connection point of the second inductance means
The emitter terminal connected to the
And a collector terminal connected to the side of each of the semiconductor elements
Gate terminal connected to the gate side of the
Output terminal, the emitter terminal, the collector terminal and the front
The gate terminal is held, and the semiconductor element and the first and second
And a storage means for storing the second inductance means.
It is characterized by being equipped.

[0011]

[0012]

According to a second aspect of the present invention, in a pressure contact type semiconductor module in which a plurality of power semiconductor elements are connected in parallel, and a common collector post electrode body and a common emitter post electrode body are in pressure contact with each other, the emitter post is provided. The electrode body also serves as an emitter terminal and a signal emitter terminal, and an inductance means is sandwiched between the emitter side of the semiconductor element and the emitter post electrode body to form the collector side of the semiconductor element and the collector post electrode body. It is characterized in that a contact terminal is sandwiched between the two and pressed together with the semiconductor element.

[0014]

As described above, the fact that the emitter terminals of the semiconductor elements connected in parallel fluctuate due to the voltage drop generated in the inductance conductor is utilized to lower the voltage between the gate and the emitter of the element having a large current. Since the voltage between the gate and the emitter of a device having a small current can be increased, the current balance of each semiconductor device can be obtained.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, 11A
11D is a reactor, 12 is a common emitter terminal, and other elements correspond to the same numbers in FIG. FIG. 1 shows the structure of a semiconductor module.

For example, consider a case where the threshold value of the IGBT 6A is lower than that of other IGBTs. When the output of the gate drive circuit is changed from -15V to + 15V, the potential of the gate terminal 9 rises. Gate terminal potential is IGBT6A
When the threshold value is exceeded, the current I6A flows through the IGBT6A. At this time, the following voltage VL is applied to the reactor 11A.
(= L * derivative (I6A)) occurs. However, L is the inductance value of the reactor 11A.

This VL is applied in the direction of lowering the GE voltage of the IGBT 6A with respect to the gate terminal-emitter terminal voltage. Therefore, only in the IGBT 6A having a low threshold value, the voltage between the GEs becomes low, the turn-on is delayed, and the current imbalance is prevented from becoming large. This VL is I
The larger the current is concentrated in the GBT 6A, the larger the value.

On the contrary, in the turn-off, the IG having a high threshold value is used.
The BTs 6B to 6C try to enter the OFF operation first, but if the current is concentrated in the IGBT 6A at this time, the voltage between the G and E of the IGBT 6A is different from that of the other IGs as in the case of the turn-on.
Since it is lower than BT, the current is equalized and simultaneously turned off.

That is, the E potential of each IGBT is
By varying according to the current change rate applied to the reactor, a difference occurs between the GE voltages of the IGBTs. As a result, the current balance between the IGBTs during turn-on and turn-off is improved.

As described above, the GE voltage of the IGBT which has been turned on or off before is controlled, so that the current balance during the transition can be improved. The reactors 11A to 11D are several tens of n.
Since a sufficient effect can be obtained at about H, it is possible to configure the reactor with a conductor having a length of several cm.

Further, even if a resistor is connected in series to the G terminal of each IGBT, the same effect can be obtained. Furthermore, as shown in Fig. 2, a 2in1 type module
It is also possible to apply to

A second embodiment of the present invention will be described with reference to FIG. The present embodiment is different from the first embodiment in that two IGBTs are put together. Reactor 11E balances reactors 11A and 11B, and reactor 11F reacts to reactors 11C and 1B.
It has a 1D balance.

By combining several IGBTs in this way, the number of parallel IGBTs does not become complicated even when the number of parallels increases,
The current balance can be improved. A third embodiment of the present invention will be described with reference to FIG.

The present embodiment is characterized in that the Zener diode 13 is added to the constituent elements. As a result of providing the Zener diode, the overvoltage is not applied between the GEs.
As described above, by inserting the Zener diode between the GEs of the IGBT, it is possible to prevent the overvoltage generated due to the resonance of the input capacitance of the IGBT and the reactor.

A fourth embodiment of the present invention will be described with reference to FIG. The present embodiment shows a case where the present invention is applied to a pressure contact type module. In FIG. 5, 107
Is a dielectric block, and the other constituent elements correspond to the same numbers as in FIG. The upper surface of the IGBT 103 is an emitter. The circuit configuration is the same as in FIG. The dielectric block is formed, for example, by stacking a conductor and an insulator. As described above, by inserting the dielectric block, the emitter potential of each IGBT is changed when a current variation occurs, and a difference is generated in the GE voltage. Improve the current balance of.

A fifth embodiment of the present invention will be described with reference to FIG. This embodiment is the same as any one of the first to fourth embodiments, except that the DC voltage source 1 and the IGBT 6 are gated.
A gate drive circuit 4 for supplying a control signal is added to the power converter. Thus, the first
The semiconductor module according to any one of the fourth to fourth embodiments is configured as a power conversion device, and
Damage to T is less likely to occur, and the reliability of the power conversion device is improved.

[0028]

As described above, according to the present invention, when the emitter potentials of the IGBTs connected in parallel in the module are changed, when the currents between the IGBTs become unbalanced, respectively. It is possible to suppress the current imbalance by acting in the direction in which the GE voltage of the IGBT is balanced.

[0029]

[Brief description of drawings]

FIG. 1 is a circuit diagram of a semiconductor module according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a semiconductor module according to the first embodiment of the present invention.

FIG. 3 is a circuit diagram of a semiconductor module according to a second embodiment of the present invention.

FIG. 4 is a circuit diagram of a semiconductor module according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a pressure contact type semiconductor module according to a fourth embodiment of the present invention.

FIG. 6 is a circuit diagram of a power conversion device according to a fifth embodiment of the present invention.

FIG. 7 is a circuit diagram of a conventional power converter.

FIG. 8 is a configuration diagram of a conventional pressure contact type semiconductor module.

[Explanation of symbols]

1 DC voltage source 2 IGBT module 3 load 4 Gate drive circuit 5 Gate resistance 6 IGBT 7 collector terminal 8 Emitter terminal 9 Gate terminal 10 Signal emitter terminal 11 reactor 12, 14 Common emitter terminal 13 Zena diode 101 Emitter post 102 collector post 103 IGBT chip 104 Mo substrate 105 contact terminals 106 Positioning guide 107 induction pair block

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02M 1/00 H02M 1/08 341

Claims (2)

(57) [Claims] 1. A plurality of semiconductor elements connected in parallel, a first inductance means connected in series on an emitter side of the semiconductor element, and a plurality of first inductance means of the first inductance means. Second inductance means connected in series to the parallel connection point of the second inductance means, a signal emitter terminal connected to the opposite side of the parallel connection point of the second inductance means, and the parallel connection of the second inductance means. An emitter terminal connected to the side opposite to the connection point, a collector terminal connected to the collector side of each semiconductor element, a gate terminal connected to the gate side of each semiconductor element, the signal emitter terminal, Holding the emitter terminal, the collector terminal and the gate terminal, the semiconductor element and the first and second inductance means A semiconductor module comprising: a storing means for storing the. 2. A pressure-contact type semiconductor module in which a plurality of power semiconductor elements are connected in parallel and press-contact with a common collector post electrode body and a common emitter post electrode body, wherein the emitter post electrode body is an emitter terminal. Also serving as a signal emitter terminal, an inductance means is sandwiched between the emitter side of the semiconductor element and the emitter post electrode body, and between the collector side of the semiconductor element and the collector post electrode body,
A pressure-contact type semiconductor module, which sandwiches a contact terminal and press-contacts with a semiconductor element at the same time.