JP2002315303A - Power module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of the increase of manufacturing processes and of receiving restriction on electrical performance, when a protective sensing part is provided on a power device in a power module comprising the power device and a control IC that controls the device. SOLUTION: On the power device, sensing parts for protection against overcurrent and temperature and a protective circuit that discriminates abnormality from detection signals from the sensing parts and that breaks the gate voltage of the power device are provided. On the control IC, a circuit is provided for detecting the protected state of the power device by the gate voltage or the output current of the power device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power module provided with an overcurrent and temperature protection circuit.

[0002]

2. Description of the Related Art Power devices (IGBT, MOS-F) mounted on a power module constituting an inverter circuit
ET), overcurrent protection (short-circuit protection, RT
C), temperature protection is required. In the conventional power module, using the current sense and temperature sense of the IGBT,
The state of the IGBT is detected, and the detected value is compared with a determination value by a control IC mounted on the power module to protect the IGBT.

FIG. 1 shows an IGBT provided with temperature sensing and current sensing functions. In addition to a collector C, an emitter E and a gate G of the IGBT, a current sensing terminal S and an anode terminal A of temperature sensing Di are required. Become.

[0004]

For this reason, four new wire pads of the IGBT chip are required, which is an ill effect of miniaturization for power modules that are being miniaturized. In addition, the area of the wire pad of the emitter is reduced by increasing the number of current sensing and temperature sensing terminals. There is a problem that the limit of the current that can be flowed is reduced by reducing the number of wires that can be hit.

Since the control IC needs a temperature protection device and an overcurrent protection circuit as described later, the control IC
C circuit became complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a power module capable of simplifying a circuit configuration and reducing manufacturing costs.

[0007]

A power module comprising a power device according to the present invention and a control IC for controlling the power device is provided with a sense section for overcurrent protection and temperature protection, and a sense section for these sense sections. The control circuit includes a protection circuit that determines an abnormality based on the detection signal and shuts off a gate voltage of the power device, and a control IC includes a circuit that detects a protection state by the gate voltage.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 2 shows an IGBT_1 with a protection function in a power module (corresponding to claim 1) of the present invention. As shown, the protection circuit 10 is mounted on an IGBT chip. This protection circuit 10 incorporates the temperature protection device shown in FIG. 3 and the overcurrent protection circuit shown in FIG.
Temperature abnormality is detected from the voltage detected between Q4 and
An overcurrent state is detected from the voltage detected between 3-Q4. If any abnormality is detected, the terminal Q1 becomes low level, thereby lowering the gate voltage and shutting off the gate, thereby protecting the IGBT_1.
Note that R1 in FIG. 4 is a resistor for detecting an output current flowing through the IGBT.

FIG. 5 shows a control IC_20 in the power module. As shown, a function capable of detecting the voltage of the gate terminal G of the IGBT_1 is added.
That is, the gate voltage is compared with the reference voltage Vref by the comparator COM, and when the voltage falls below Vref, an error signal indicating an abnormal state can be output to the outside. This control IC_20 does not include the protection circuit as shown in FIGS.

In order to perform self-protection on the IGBT chip side,
Temperature sensing and current sensing terminals (wire pads) are not required, and miniaturized mounting is possible. Further, since the control IC detects an abnormal state of the IGBT as a decrease in the gate voltage, the circuit of the control IC does not become complicated. The same effects can be obtained in each of the embodiments described below.

Embodiment 2 IGBT_1 with protection circuit in FIG. 2 and control IC_ in FIG. 5
By converting the power module 20 into a power module with a transfer mold structure and eliminating external components, a compact power module can be realized.

Embodiment 3 FIG. 6 shows an IGBT_2 with protection function (corresponding to claim 3) in the power module of the present invention. IGBT_ of FIG.
As can be seen from the elimination of the terminal Q3 and the resistor R1 at 1, the protection circuit 11 performs only temperature protection.

Embodiment 4 IGBT_1 with protection circuit in FIG. 6 and control IC_ in FIG. 5
By converting the power module 20 into a power module with a transfer mold structure and eliminating external components, a compact power module can be realized.

Embodiment 5 FIG. 7 shows an IGBT_3 with a protection function in a power module according to the present invention (corresponding to claim 5). IGBT_ of FIG.
In this embodiment, the detection of the occurrence of the abnormality in the first embodiment is performed by using the output current of the IGBT instead of the detection of the occurrence of the abnormality in the gate voltage. Sent instead of voltage. In this case as well, the same effect can be obtained as when the occurrence of an abnormality is detected by the gate voltage.

The IGBT_3 with the protection circuit in FIG. 7 and the control IC_20 in FIG. 5 are made into a power module with a transfer molding structure, and a small power module can be realized by eliminating external parts.

Embodiment 6 FIG. 8 shows an IGBT_4 with a protection function in a power module according to the present invention (corresponding to claim 6). This device replaces the detection of the gate voltage in FIG. 6 with the detection of the output current.

Embodiment 7 FIG. 9 shows an IGBT_5 with protection function (corresponding to claim 7) in the power module of the present invention. This IGBT_5
Is the protection circuit 1 instead of the protection circuit 10 of the IGBT_3.
2 is provided. When the gate voltage does not decrease even after a predetermined time has elapsed since the protection circuit 12 detects an overcurrent or abnormal temperature in this circuit, it is determined that the protection function is not normal. The predetermined time is a time sufficiently longer than a time lag from the detection of an abnormality such as an overcurrent to the actual operation of protection.

This protection circuit 12 can be mounted on each of the IGBTs shown in FIGS. 2, 6, 7 and 8. By providing such a determination means, it is possible to know whether the protection function of the protection circuit 12 is normal.

Embodiment 8 A control IC in a power module according to the present invention (claim 8)
In the case of operation with the capacitor voltage of the bootstrap circuit, when the IGBT chip performs the protection operation, the gate drive current of the IGBT chip increases, thereby decreasing the voltage of the bootstrap capacitor. By detecting the voltage drop on the control IC side, IGB
An abnormal state of T is detected.

Embodiment 9 FIG. 10 shows an IGBT_6 with overvoltage protection function (corresponding to claim 9). An IC circuit including an IGBT chip having the built-in temperature protection, overcurrent protection, and overvoltage protection, and a control IC capable of detecting an abnormal state of the IGBT based on the gate voltage of the IGBT can be realized.

Embodiment 10 FIG. 11 shows an IGBT_7 with an overvoltage protection function (corresponding to claim 10). An IGBT chip having built-in temperature protection, overcurrent protection and overvoltage protection, and the IGBT
An IC circuit comprising a control IC capable of detecting an abnormal state of the IGBT by the output current of the IGBT can be realized.

[0022]

As described above, according to the present invention, the power device is provided with a sense section for overcurrent protection and temperature protection, and an abnormality is determined from detection signals from these sense sections to determine whether the power device is abnormal. Since a protection circuit for shutting off the gate voltage is provided and self-protection is performed on the power device side, terminals for temperature sensing and current sensing for extraction are not required. For this reason, miniaturized mounting is possible, and a small-sized power module in one package can be realized, and the current limit as described above does not occur.

When an abnormality is detected and the protection functions, the gate voltage is reduced. However, the gate voltage is reduced or the output current changes due to the reduced gate voltage to a predetermined value even after a predetermined time has elapsed. Since the control IC is provided with a circuit for detecting that it does not return, it can be determined whether the protection function of the protection circuit is normal, and higher reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is an IGBT with a sense function

FIG. 2 is a circuit diagram of an IGBT according to the present invention.

FIG. 3 is a circuit diagram of a temperature protection unit in the protection circuit of FIG. 2;

FIG. 4 is a circuit diagram of an overcurrent protection unit in the protection circuit of FIG. 2;

FIG. 5 is a circuit diagram of a control IC according to the present invention.

FIG. 6 is a circuit diagram of another IGBT according to the present invention.

FIG. 7 is a circuit diagram of another IGBT according to the present invention.

FIG. 8 is a circuit diagram of another IGBT according to the present invention.

FIG. 9 is a circuit diagram of another IGBT according to the present invention.

FIG. 10 is a circuit diagram of another IGBT according to the present invention.

FIG. 11 is a circuit diagram of another IGBT according to the present invention.

[Explanation of symbols]

1,2,3,4,5 IGBT, 10,11,12 protection circuit, 20 control IC

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/62 H01L 23/56 A 27/04 D H03K 17/08 C 17/56 H03K 17/56 Z ( 72) Inventor Masanori Fukunaga 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Mitsubishi Electric Corporation (reference) 2G035 AA15 AB01 AC08 AD10 5F038 BH02 BH04 BH11 BH16 DF01 DT12 EZ20 5H740 AA00 AA10 BA11 BC01 BC02 JB01KK01 MM01 MM08 MM11 PP02 5J055 AX15 AX32 AX44 AX64 BX16 CX07 DX06 DX09 DX52 EX02 EX07 EY01 EY03 EY10 EY12 EY13 EY21 EZ10 EZ25 EZ32 FX05 FX13 FX32 GX01

Claims (10)

[Claims] In a power module including a power device and a control IC for controlling the power device, an abnormality is determined in the power device from a sense unit for overcurrent protection and temperature protection, and a detection signal from the sense unit. A protection circuit for shutting off a gate voltage of the power device, and a control IC including a circuit for detecting a protection state by the gate voltage. 2. The power module according to claim 1, wherein no external parts are provided and only the power device and the control IC are used. 3. A power module comprising a power device and a control IC for controlling the power device, wherein the power device is provided with a sense section for temperature protection, and an abnormality is determined from a detection signal from the sense section to determine whether the power device is abnormal. A power module comprising: a protection circuit for cutting off a gate voltage; and a control IC including a circuit for detecting a protection state by a gate voltage. 4. The power module according to claim 3, wherein external components are eliminated and the power module is formed only by the power device and the control IC. 5. The power module according to claim 1, wherein the control IC includes a circuit for detecting a protection state by an output current of the power device. 6. The power module according to claim 3, wherein the control IC includes a circuit for detecting a protection state by an output current of the power device. 7. The power module according to claim 3, wherein a circuit for detecting that a change in the gate voltage or the output current does not return to a predetermined value even after a predetermined time has elapsed is provided in the control IC. 8. The power module according to claim 1, wherein the control IC includes a circuit that detects a voltage change of a bootstrap capacitor and detects an abnormal state of the power device. 9. A power module comprising a power device and a control IC for controlling the power device, wherein the power device is provided with a sense section for overcurrent protection, temperature protection, and overvoltage protection, and an abnormality based on a detection signal from the sense section. A power module, comprising: a protection circuit for determining a gate voltage of the power device and determining a protection state by the gate voltage in the control IC. 10. A power module comprising a power device and a control IC for controlling the power device, wherein the power device is provided with a sense unit for overcurrent protection, temperature protection, and overvoltage protection, and an abnormality based on a detection signal from the sense unit. A power module, comprising: a protection circuit for determining the protection voltage and determining a protection state by an output current of the power device.