Power semiconductor module with overcurrent detection unit

Abstract

The invention relates to a power semiconductor module having a substrate arranged in a housing, a power semiconductor switch on the substrate having its load current input and an overcurrent detection circuit being arranged in the housing, the overcurrent detection circuit (9) being electrically connected to the load current input. Wherein the power semiconductor switch further has a load current output and a control input, and an activation device arranged outside the housing, with a limit monitoring unit, the activation device being electrically connected to the control input and the limit monitoring unit being electrically connected to the overcurrent detection circuit.

Description

Technical Field

[0001] The invention describes a power semiconductor module having a substrate arranged in a housing, wherein an overcurrent detection circuit and a power semiconductor switch and a load current input thereof are arranged on the substrate in the housing. Background Art

[0002] DE 10 201 4 110 768 B3 discloses a power semiconductor circuit having a power semiconductor switch, an activation device and an overcurrent detection circuit, wherein the overcurrent detection circuit has a limit monitoring unit and a first capacitor and a second capacitor. Summary of the invention

[0003] Knowing the above, the present invention is based on the object of providing a power semiconductor module having an optimized overcurrent detection circuit which has a small space requirement.

[0004] According to the present invention, the object is achieved by a power semiconductor module having a substrate arranged in a housing, wherein an overcurrent detection circuit and a power semiconductor switch and a load current input thereof are arranged on the substrate in the housing, wherein the overcurrent detection circuit is electrically connected to the load current input, the power semiconductor switch also has a load current output and a control input, and has an activation device arranged outside the housing, has a limit monitoring unit, wherein the activation device is electrically connected to the control input, and the limit monitoring unit is electrically connected to the overcurrent detection circuit.

[0005] Preferably, the limit monitoring unit is designed to generate an overcurrent detection signal if the voltage at the first input of the limit monitoring unit exceeds a reference voltage applied at the second input of the limit monitoring unit.

[0006] Furthermore, preferably, the activation device is designed to generate an activation voltage for turning off the power semiconductor switch when receiving the overcurrent detection signal.

[0007] Furthermore, preferably, the overcurrent detection circuit has a resistor, a diode, and a Zener diode.

[0008] It can also be provided that the diode is designed as a series circuit of a plurality of partial diodes.

[0009] In this case, it is advantageous if the cathode of the diode is connected to the load current input, the anode of the diode is connected to the first contact of the resistor, and the second contact of the resistor is connected to the first input of the limit monitoring unit and to the cathode of the Zener diode, and wherein the anode of the Zener diode is connected to the load current output.

[0010] It is also advantageous if the diode and the second resistor are arranged on the first conductive track and if the Zener diode is arranged on the second conductive track.

[0011] It is also advantageous if the overcurrent detection circuit is designed as an integrated circuit, in particular an unpackaged one.

[0012] Furthermore, it is advantageous if the power semiconductor switch and the overcurrent detection circuit are connected to the first electrically conductive track in a material-bonded manner. In this case, it is advantageous if the material-bonded connection is designed as an adhesive, sintering or welding connection.

[0013] Of course, features or feature groups mentioned in each case in the singular may be present multiple times in the module or power semiconductor component according to the invention, without this being explicitly or per se excluded or without contradicting the concept of the invention.

[0014] It should be understood that the various embodiments of the present invention can be implemented alone or in any desired combination to achieve improvements. In particular, the features mentioned and explained above and below can be used not only in the specified combination, but also in other combinations or alone without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Further explanations, advantageous details and features of the invention are to be found in the following description of exemplary embodiments of the invention or corresponding parts thereof, which are described in Figure 1 to Figure 2 It is schematically shown in FIG.

[0016] Figure 1 A detail of a power semiconductor circuit of a power semiconductor module according to the invention is shown.

[0017] Figure 2 An embodiment of a power semiconductor circuit of a power semiconductor module according to the invention is shown. DETAILED DESCRIPTION

[0018] Figure 1 Details of an embodiment of a power semiconductor circuit 1 of a power semiconductor module 4 according to the invention are shown.

[0019] Figure 1Detail of a power semiconductor circuit 1 of a power semiconductor module according to the invention is shown, which has a control device 3 and a housing 4. The power semiconductor circuit 1 also has an overcurrent detection circuit 5 and a power semiconductor switch T1. In this case, the overcurrent detection circuit 5 and the load current input 10 of the power semiconductor switch T1 are arranged on a substrate inside the housing 4 of the power semiconductor module and are electrically connected to each other. The power semiconductor switch T1 also has a load current output 12 and a control input 14, which are also arranged in the housing 4. The control device 3 has an activation device 2 (see Figure 2 ), a limit monitoring unit 6, a first resistor R1 and a first capacitor C1. The control device 3 is arranged outside the housing 4. In this case, a first input of the limit monitoring unit 6, a first terminal of the first capacitor C1, a first terminal of the overcurrent detection circuit 5 and a first terminal of the first resistor R1 are electrically connected via an electrical connection 7. A second terminal of the first capacitor C1 is electrically connected to a load current output 12 of the power semiconductor switch T1 and to a second terminal of the overcurrent detection circuit 5. The activation device 2 is designed for activating the power semiconductor switch T1 and is electrically connected to its control input 14. For this purpose, the activation device 2 generates an activation voltage Ua at the control input 14 of the power semiconductor switch T1 depending on the control signal 9, see Figure 2 The control signal is generated, for example, by a superior control (not shown). The power semiconductor switch T1 is turned on and off based on the level of the activation voltage Ua.

[0020] The power semiconductor switch T1 is designed here as an IGBT. This can also be formed, for example, by a plurality of IGBTs connected in parallel. The collector terminal of the respective IGBT then forms the load current input, the emitter terminal forms the load current output, and the gate terminal forms the control input. Alternatively, however, the power semiconductor switch T1 can also be designed as a MOSFET, preferably as a MOSFET with a large band gap, i.e. a SiC or GaN MOSFET, or as a parallel circuit of MOSFETs. In each case, the drain terminal then forms the load current input, the source terminal forms the load current output, and the gate terminal forms the control input.

[0021] Figure 2 An exemplary embodiment of a power semiconductor circuit 1 of a power semiconductor module according to the invention is shown in detail. Figure 2 and Figure 1The difference is that the above-mentioned activation device 2 is additionally shown here. In addition, the overcurrent detection circuit 5 here has, for example, a second resistor R2, a first fast switching diode D1 and a second fast switching diode D2 with a low junction capacitance, and a Zener diode Z1 with 15 V, purely by way of example. Here, the cathode of the second diode D2 is connected to the load current input 10, and the anode of the first diode D1 is connected to the first contact of the second resistor R2. Therefore, the first diode D1 and the second diode D2 are connected in series. The second contact of the second resistor R2 is electrically connected to the first input of the limit monitoring unit 6 and to the cathode of the Zener diode Z1. In addition, the anode of the Zener diode Z1 is electrically connected to the load current output 12 of the power semiconductor switch T1 and to the second terminal of the first capacitor C1.

[0022] Alternatively, the overcurrent detection circuit 5 may also have only one diode, or be designed as a series circuit consisting of a plurality of partial diodes (more than two). The two diodes D1, D2 and the second resistor R2 are arranged on the first conductive trace of the substrate and connected in a material-bonded manner by sintering, for example. For example, the Zener diode Z1 is also arranged on the second conductive trace of the substrate and is connected to the substrate in a material-bonded manner by welding. Optionally, the corresponding connection may also be designed as a different material-bonded connection, for example, as an adhesive connection.

[0023] If the second voltage U2 at the first input of the limit monitoring unit 6 exceeds the reference voltage Ur applied at the second input of the limit monitoring unit 6, the limit monitoring unit 6 generates an overcurrent detection signal 8. The overcurrent detection signal 8 is provided as an input signal to the activation device 2. When receiving the overcurrent detection signal 8, the activation device 2 turns off the power semiconductor switch T1 if the power semiconductor switch T1 is turned on.

[0024] In the switched-on state of the power semiconductor switch T1, for example in the case of a short circuit, if the current I1 flowing through the power semiconductor switch T1 becomes very large, the voltage U1 applied between the first and second load current inputs 10 and the load current output 12 increases strongly, which results in a short-term transient current flowing through the first capacitor C1. As a result, the first capacitor C1 is charged and the voltage U2 increases. If the voltage U2 at the first input of the limit monitoring unit 6 exceeds the reference voltage Ur applied at the second input of the limit monitoring unit 6, an overcurrent detection signal 8 is generated by the limit monitoring unit 6 and supplied as an input signal to the activation device 2. If the overcurrent detection signal 8 is received, the activation device 2 turns off the power semiconductor switch T1 and thus protects the power semiconductor switch T1 upstream of the overcurrent flowing through it.

[0025] Reference numerals

[0026] 1 Power semiconductor circuit

[0027] 2Activation device

[0028] 3. Control Device

[0029] 4 Shell

[0030] 5Overcurrent detection circuit

[0031] 6 Limit monitoring unit

[0032] 7 Connectors

[0033] 8Overcurrent detection signal

[0034] 9 Control signal

[0035] 10 Load current input

[0036] 12 load current output

[0037] 14 Control input

[0038] C1 first capacitor

[0039] D1 first diode

[0040] D2 second diode

[0041] I1 Current

[0042] R1 first resistor

[0043] R2 second resistor

[0044] T1 power semiconductor switch

[0045] U1 first voltage

[0046] U2 second voltage

[0047] UA activation voltage

[0048] Ur reference voltage.

Claims

1. A power semiconductor module, comprising a substrate arranged in a housing (4), wherein a power semiconductor switch (T1) and an overcurrent detection circuit (5) are arranged on the substrate inside the housing (4), the power semiconductor switch (T1) having its load current input (10), wherein the overcurrent detection circuit (5) is electrically connected to the load current input (10); The power semiconductor switch (T1) further has a load current output (12) and a control input (14); The invention also comprises an activation device (2) arranged outside the housing, and a limit monitoring unit (6), wherein the activation device (2) is electrically connected to the control input (14), and the limit monitoring unit (6) is electrically connected to the overcurrent detection circuit (5).

2. The power semiconductor module according to claim 1, characterized in that: The limit monitoring unit (6) is designed to generate an overcurrent detection signal (8) if the voltage at the first input of the limit monitoring unit (6) exceeds a reference voltage (Ur) applied at the second input of the limit monitoring unit (6).

3. The power semiconductor module according to claim 2, characterized in that: The activation device (2) is designed to generate an activation voltage (Ua) for turning off the power semiconductor switch (T1) when receiving an overcurrent detection signal (8).

4. The power semiconductor module according to claim 1, characterized in that: The overcurrent detection circuit (5) has a second resistor (R2), a diode (D1) and a Zener diode (Z1).

5. The power semiconductor module according to claim 4, characterized in that: The diode (D1) is designed as a series circuit of a plurality of partial diodes (D1, D2).

6. The power semiconductor module according to claim 5, characterized in that: The cathode of the diode (D1) is connected to the load current input (10), the anode of the diode is connected to the first contact of the second resistor (R2), and the second contact of the second resistor (R2) is connected to the first input of the limit monitoring unit (6) and the cathode of the Zener diode (Z1), and the anode of the Zener diode (Z1) is connected to the load current output (12).

7. The power semiconductor module according to claim 6, characterized in that: The diode and the second resistor (R2) are arranged on a first conductive trace, and the Zener diode (Z1) is arranged on a second conductive trace.

8. The power semiconductor module according to any one of claims 1 to 3, characterized in that: The overcurrent detection circuit (5) is designed as an integrated circuit.

9. The power semiconductor module according to claim 7, characterized in that: The power semiconductor switch (T1) and the overcurrent detection circuit (5) are connected to the first conductive track in a materially bonded manner.

10. The power semiconductor module according to claim 9, characterized in that: The material-bonded connection is designed as an adhesive, sintering or welding connection.

11. The power semiconductor module according to claim 8, characterized in that: The overcurrent detection circuit (5) is designed as an unpackaged integrated circuit.

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