JP4804304B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device, and more particularly to a semiconductor device that performs overtemperature protection.

In order to prevent thermal destruction of a semiconductor device, a semiconductor device that detects temperature using temperature characteristics of a diode or the like has been developed (for example, see Patent Documents 1 to 8).
Japanese Patent Laid-Open No. 06-117942 Japanese Patent Laid-Open No. 08-236709 JP 08-316471 A JP 09-229778 A JP-A-10-116987 JP 2002-368222 A Japanese Patent Laid-Open No. 06-342876 JP 2003-204028 A

  For example, in a conventional semiconductor device including a switch element such as an IGBT (Insulated Gate Bipolar Transistor) for driving a motor, the switch element is repeatedly switched between an on state and an off state to drive the motor. Here, the loss that occurs when switching the switching element becomes thermal stress, which may cause solder cracks, wire peeling, and the like in a circuit that detects temperature. In such a case, temperature detection cannot be performed normally, and the semiconductor device is thermally destroyed.

  Therefore, an object of the present invention is to provide a semiconductor device capable of appropriately performing overtemperature protection.

  In order to solve the above-described problem, a semiconductor device according to an aspect of the present invention detects a switch element, a drive circuit that supplies a voltage to the switch element, an ambient temperature, and the detected ambient temperature is higher than a reference temperature. Includes an overtemperature protection circuit that controls the voltage supply to the switch element by the drive circuit to turn off the switch element, and a failure detection circuit that includes a wire and lowers the reference temperature when the wire peels off .

  According to the present invention, overtemperature protection can be performed appropriately.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<First Embodiment>
[Configuration and basic operation]
FIG. 1 is a diagram showing a configuration of a semiconductor device according to the first embodiment of the present invention.

  Referring to FIG. 1, a semiconductor device 100 includes an overtemperature protection circuit 1, a failure detection circuit 2, a drive circuit 3, a short circuit / overcurrent protection circuit 4, a logic gate 5, and a switch element that is, for example, an IGBT. SW1. The overtemperature protection circuit 1 includes a diode D1, a comparator G1, and a power supply PS2. Failure detection circuit 2 includes wires W1 to W3, resistors R1 and R2, and a power supply PS1.

  One end of the wire W2 is connected to one end of the resistor R1 and one end of the resistor R2, and the other end of the wire W2 is connected to one end of the wire W1 and the anode of the diode D1.

  The other end of the wire W1 is connected to the other end of the resistor R2 and the inverting input terminal (first input terminal) of the comparator. The non-inverting input terminal (second input terminal) of the comparator is connected to the output of the power source PS2.

  The other end of the resistor R1 is connected to the output of the power source PS1, that is, the first voltage V1 is supplied to the other end of the resistor R1.

  One end of the wire W3 is connected to the cathode of the diode D1, and the other end of the wire W3 is connected to the ground potential. That is, the ground voltage (second voltage V2) is supplied to the cathode of the diode D1.

FIG. 2 is a diagram illustrating a positional relationship between the semiconductor chip and the wire.
Referring to FIG. 2, semiconductor device 100 includes semiconductor chips CP1 and CP2. In the semiconductor chip CP1, one or a plurality of switch elements SW1 and a diode D1 in the overtemperature protection circuit 1 are formed. In the semiconductor chip CP2, the comparator G1 and the power source PS2, the failure detection circuit 2, the drive circuit 3, the short circuit / overcurrent protection circuit 4, and the logic gate 5 in the overtemperature protection circuit 1 are formed.

  Pads PD1 to PD5 are arranged in the semiconductor chip CP1, and wires W1 to W5 are joined to each other. Semiconductor chips CP1 and CP2 are connected via wires W1 to W5. A bonding portion (pad PD2) of the wire W2 is disposed at a substantially central portion of the semiconductor chip CP1. Wires W1-W5 are, for example, aluminum wires.

Referring to FIG. 1 again, drive circuit 3 supplies a voltage to the gate of switch element SW1.
The switch element SW1 switches between an on state and an off state based on the voltage supplied from the drive circuit 3.

  The short circuit / overcurrent protection circuit 4 monitors the amount of current in the switch element SW1, and controls the voltage supply to the switch element SW1 by the drive circuit 3 when a short circuit or overcurrent in the switch element SW1 is detected. Then, the switch element SW1 is turned off. More specifically, the short circuit / overcurrent protection circuit 4 outputs an H level signal to the logic gate 5 when a short circuit or overcurrent is detected in the switch element SW1. Here, logic gate 5 is, for example, an OR gate, and outputs an H level signal to terminal S of drive circuit 3 when it receives an H level signal from temperature protection circuit 1 or short circuit / overcurrent protection circuit 4. The drive circuit 3 receives the H level signal from the logic gate 5 and turns off the switch element SW1.

  The overtemperature protection circuit 1 detects the ambient temperature, and when the detected ambient temperature is higher than the reference temperature, controls the voltage supply to the switch element SW1 by the drive circuit 3 to turn off the switch element SW1. The reference temperature is, for example, 145 ° C. when the switch element SW1 is an IGBT. More specifically, the diode D1 has a temperature coefficient with a negative forward voltage. For this reason, when the ambient temperature of the diode D1 rises, the voltage applied to the inverting input terminal of the comparator G1 decreases. When the voltage applied to the inverting input terminal of the comparator G1 becomes smaller than the voltage applied to the non-inverting input terminal of the comparator G1, the comparator G1 sends an H level signal via the logic gate 5 to the terminal S of the drive circuit 3. Output to. When the signal received from the comparator G1 becomes H level, the drive circuit 3 turns off the switch element SW1.

  The failure detection circuit 2 lowers the reference temperature used by the overtemperature protection circuit 1 when the wire W2 is peeled off.

  FIG. 3 is a diagram illustrating the relationship between the voltage applied to the diode D1 and the current flowing through the diode D1. For reference, the characteristics of the diode D1 at high and low temperatures are also shown in FIG.

  Referring to FIG. 3, point A shows a state where wire W2 is peeled off, and point B shows a state where wire W2 is not peeled off.

  When the wire W2 is not peeled off, a circuit is formed in which the resistor R1 and the diode D1 are connected in series between the first voltage V1 and the second voltage V2 (ground voltage). On the other hand, when the wire W2 is peeled off, a circuit is formed in which the resistor R1, the resistor R2, and the diode D1 are connected in series between the first voltage V1 and the second voltage V2.

  For this reason, when the wire W2 is peeled, the voltage applied to the diode D1 is smaller than when the wire W2 is not peeled, and the current flowing through the diode D1 is small. As a result, the voltage applied to the inverting input terminal of the comparator G1 decreases, and the reference temperature used by the overtemperature protection circuit 1 decreases. That is, when the wire W2 is peeled off, the voltage applied to the inverting input terminal of the comparator G1 under the same temperature condition is smaller than that when the wire W2 is not peeled off. The comparator G1 outputs an H level signal at a lower temperature than when the wire W2 is not peeled.

FIG. 4 is a circuit diagram showing the configuration of the drive circuit.
Referring to FIG. 4, drive circuit 3 includes power supplies PS11 and PS12, photocoupler FC1, amplifier G11, transistors TR1 and TR2, and resistor R11. The semiconductor device 100 includes an IGBT as the switch element SW1. The gate of the IGBT is connected to the resistor R11. The emitter of the IGBT is connected to a connection point between the power supply PS11 and the power supply PS12 connected in series.

  During normal operation, the amplifier G11 outputs an H level or L level signal in accordance with the input signal IN. In addition, when the signal received from the comparator G1 or the short circuit / overcurrent protection circuit 4 in the overtemperature protection circuit 1 is at the H level, the amplifier G11 outputs an L level signal regardless of the input signal IN.

  When the output signal of the amplifier G11 in the drive circuit 3 becomes H level, the transistor TR1 is turned on and the transistor TR2 is turned off. Then, a positive voltage is applied between the gate and emitter of the IGBT to turn on the IGBT, and a current flows between the collector and emitter of the IGBT. On the other hand, when the output signal of the amplifier G11 becomes L level, the transistor TR1 is turned off and the transistor TR2 is turned on. Then, a negative voltage is applied between the gate and emitter of the IGBT, the IGBT is turned off, and no current flows between the collector and emitter of the IGBT.

  FIG. 5 is a circuit diagram showing a configuration of a modified example of the drive circuit. Referring to FIG. 5, semiconductor device 100 includes a bipolar transistor as switch element SW1. The base of the bipolar transistor is connected to the resistor R11. The emitter of the bipolar transistor is connected to a connection point between the power supply PS11 and the power supply PS12 connected in series. The drive circuit 3 controls the output current by changing the potential between the base and the emitter of the bipolar transistor.

  Since the bipolar chip manufacturing process is cheaper than the IGBT chip manufacturing process, the manufacturing cost of the semiconductor device can be reduced.

  FIG. 6 is a circuit diagram showing a configuration of a modified example of the drive circuit. Referring to FIG. 6, semiconductor device 100 includes RC (Reverse Conducting) -IGBT as switch element SW1. The RC-IGBT includes a switch element and a diode. The gate of the RC-IGBT is connected to the resistor R11. The RC-IGBT emitter is connected to a connection point between the power supply PS11 and the power supply PS12 connected in series. The drive circuit 3 controls the output current by changing the potential between the gate and the emitter of the RC-IGBT.

  Here, when the IGBT drives the motor, since it is an inductive (L) load, a reverse breakdown voltage is applied when the IGBT changes from the on state to the off state, and a regenerative current flows. The IGBT is weak against reverse withstand voltage and easily broken. For this reason, it is necessary to arrange a diode for flowing current from the emitter side to the collector side of the IGBT. Therefore, the manufacturing cost of the semiconductor device can be reduced by using the RC-IGBT that can make the IGBT chip and the diode chip into one chip.

  FIG. 7 is a circuit diagram showing a configuration of a modified example of the drive circuit. Referring to FIG. 7, the semiconductor device 100 includes a MOS (Metal Oxide Semiconductor) -FET (Field Effect Transistor) as the switch element SW1. The gate of the MOS-FET is connected to the resistor R11. The source of the MOS-FET is connected to a connection point between the power supply PS11 and the power supply PS12 connected in series. The drive circuit 3 controls the output current by changing the potential between the gate and the source of the MOS-FET.

  Here, since the drain-source voltage in the on-state of the MOS-FET is smaller than the collector-emitter voltage in the on-state of the IGBT, the loss generated when switching between the on-state and the off-state is small. The device is less likely to be thermally destroyed.

  FIG. 8 is a circuit diagram showing a configuration of a modified example of the drive circuit. Referring to FIG. 8, semiconductor device 100 includes a thyristor as switch element SW1. The gate of the thyristor is connected to the resistor R11. The anode of the thyristor is connected to a connection point between the power supply PS11 and the power supply PS12 connected in series. The drive circuit 3 controls the output current by changing the potential between the gate and the cathode of the thyristor. The thyristor is easier to switch than the IGBT.

  FIG. 9 is a circuit diagram showing a configuration of a modified example of the drive circuit. Referring to FIG. 9, semiconductor device 100 includes a triac as switch element SW1. The triac gate is connected to resistor R11. The triac terminal T2 is connected to a connection point between the power supply PS11 and the power supply PS12 connected in series. The drive circuit 3 controls the output current by changing the potential between the gate and the terminal T1 of the triac.

  Although the thyristor shown in FIG. 8 can flow current only in one direction between the cathode and the anode, the current can flow in both directions between the terminal T1 and the terminal T2 by the configuration using the triac.

  FIG. 10 is a circuit diagram showing a configuration of a modified example of the drive circuit. Referring to FIG. 10, semiconductor device 100 includes a GTO (Gate Turn-Off Thyristor) as switch element SW1. The gate of GTO is connected to resistor R11. The anode of the GTO is connected to a connection point between the power supply PS11 and the power supply PS12 connected in series. The drive circuit 3 controls the output current by changing the potential between the gate and the cathode of the GTO.

  By using the GTO as the switch element, the semiconductor device can be speeded up, that is, the switching operation of the switch element can be speeded up.

  In addition to the above, for example, a diode used as a freewheeling diode may be a switching element SW1. In this case, the drive circuit having the configuration shown in FIGS. 4 to 10 is not necessary.

  The semiconductor device 100 includes an IGBT chip in which one or a plurality of IGBTs are formed as the switch element SW1, and a diode chip in which one or a plurality of diodes are formed as the switch element SW1, The diode chip may be configured as a module.

  By the way, in a conventional semiconductor device having a switching element such as an IGBT for driving a motor, for example, a loss generated when switching the switching element becomes a thermal stress, and a solder crack and a wire peeling in a circuit for detecting temperature, etc. May occur. In such a case, temperature detection cannot be performed normally, and the semiconductor device is thermally destroyed.

  However, in the semiconductor device according to the first embodiment of the present invention, the overtemperature protection circuit 1 detects the ambient temperature, and when the detected ambient temperature is higher than the reference temperature, the switch circuit SW1 is driven by the drive circuit 3. Is controlled to turn off the switch element SW1. The failure detection circuit 2 lowers the reference temperature used by the overtemperature protection circuit 1 when the wire W2 is peeled off. With such a configuration, it is possible to stop the switching operation of the switch element SW1 at least when the wire W2 is peeled off by heat to prevent the semiconductor device from being thermally destroyed. Therefore, overtemperature protection can be appropriately performed in the semiconductor device according to the first embodiment of the present invention.

  Further, in the semiconductor device according to the first embodiment of the present invention, the bonding portion (pad PD2) of the wire W2 is arranged at the substantially central portion of the semiconductor chip CP1. Here, in general, in a semiconductor chip, the temperature is most likely to rise at the center. Therefore, by arranging the bonding portion of the wire W2 at the substantially central portion of the semiconductor chip CP1, it is possible to quickly detect a temperature abnormality and to reliably prevent thermal destruction of the circuit other than the central portion of the semiconductor chip CP1. The overtemperature protection of the device can be performed appropriately.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Second Embodiment>
The present embodiment relates to a semiconductor device configured to drive an external device such as a motor with respect to the semiconductor device according to the first embodiment.

FIG. 11 is a diagram showing a configuration of a semiconductor device according to the second embodiment of the present invention.
Referring to FIG. 11, a semiconductor device 101 includes an overtemperature protection circuit 61, a failure detection circuit 62, a converter unit 51, a brake unit 52, an inverter unit 53, a CPU (Central Processing Unit) 64, and a capacitor. C1. The inverter unit 53 includes switch elements SWA to SWF, diodes DA to DF, drive circuits 3A to 3F, and the brake unit 52 includes a resistor R21, a switch element SWG, a diode DG, and a drive circuit 3G. Converter unit 51 includes diodes D11 to D16.

  Converter unit 51 converts an AC voltage received from AC power supply PS21, which is a commercial power supply, into a DC voltage.

  The inverter unit 53 drives the motor 18 using a PWM (Pulse Width Modulation) system based on the control of the CPU 64. That is, the CPU 64 controls the rotation speed of the motor 18 by changing the duty ratio of the pulse of the current flowing through the motor 18 by controlling the switching timing of each of the switch elements SWA to SWF between the on state and the off state.

  The brake unit 52 consumes surplus energy from the motor 18 by controlling the switching timing of the ON state and the OFF state of the switch element SWG.

  The overtemperature protection circuit 61 detects the ambient temperature, and when the detected ambient temperature is higher than the reference temperature, controls the voltage supply to the switch elements SWA to SWG by the drive circuits 3A to 3G to switch the switch elements SWA to SWG. Turn off. The failure detection circuit 62 lowers the reference temperature used by the overtemperature protection circuit 61 when the wire W2 is peeled off.

  Here, the reference temperature of the overtemperature protection circuit 61 is a preset ambient temperature at which the converter unit 51, the brake unit 52, and the inverter unit 53 should perform normal operations (the ambient temperature of the diode D1 in the overtemperature protection circuit 61). Set to a temperature greater than the maximum value.

  With such a configuration, the operation of the converter unit 51, the brake unit 52, and the inverter unit 53 in the semiconductor device 101 is continued to the maximum, and the thermal destruction of the converter unit 51, the brake unit 52, and the inverter unit 53 in the semiconductor device 101 is prevented. be able to.

  Since other configurations and operations are the same as those of the semiconductor device according to the first embodiment of the present invention, detailed description thereof will not be repeated here.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Third Embodiment>
The present embodiment relates to a semiconductor device configured to drive an external device such as a motor with respect to the semiconductor device according to the first embodiment. The contents other than those described below are the same as those of the semiconductor device according to the first embodiment.

FIG. 12 is a diagram showing a configuration of a semiconductor device according to the third embodiment of the present invention.
12, semiconductor device 102 includes control semiconductor integrated circuits IC1 and IC2, converter 51, switch elements SWA and SWB, diodes DA and DB, resistors R31 and R32, capacitor C1, Photocoupler FC2, CPU64, and control power supply PS31 are provided. The control semiconductor integrated circuit IC1 includes a drive circuit 3A, a gate (error output circuit) G21A, a short circuit / overcurrent protection circuit 4A, and a control power supply voltage drop protection circuit 63A. The control semiconductor integrated circuit IC2 includes a drive circuit 3A, a gate (error output circuit) G21B, a short circuit / overcurrent protection circuit 4B, a control power supply voltage drop protection circuit 63B, an overtemperature protection circuit 61, and a failure detection circuit. 62.

  Control power supply voltage drop protection circuits 63A and 63B monitor the output voltage of control power supply PS31, and when the output voltage drop of control power supply PS31 is detected, voltage supply to switch elements SWA and SWB by drive circuits 3A and 3B Respectively.

  Gates G21A and G21B send an error signal via photocoupler FC2 when an abnormality is detected in control power supply voltage drop protection circuits 63A and 63B, short circuit / overcurrent protection circuits 4A and 4B, and overtemperature protection circuit 61. It outputs to CPU64.

  Thus, by incorporating the overtemperature protection circuit 61 and the like in the control semiconductor integrated circuit IC, the number of electronic components of the semiconductor device 102 can be reduced, and the initial failure of the electronic component itself can be reduced. The defect rate in the manufacturing process can be reduced, and the manufacturing time can be shortened.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a diagram showing a configuration of a semiconductor device according to a first embodiment of the present invention. It is a figure which shows the positional relationship of a semiconductor chip and a wire. It is a figure which shows the relationship between the voltage applied to the diode D1, and the electric current which flows into the diode D1. It is a circuit diagram which shows the structure of a drive circuit. It is a circuit diagram which shows the structure of the modification of a drive circuit. It is a circuit diagram which shows the structure of the modification of a drive circuit. It is a circuit diagram which shows the structure of the modification of a drive circuit. It is a circuit diagram which shows the structure of the modification of a drive circuit. It is a circuit diagram which shows the structure of the modification of a drive circuit. It is a circuit diagram which shows the structure of the modification of a drive circuit. It is a figure which shows the structure of the semiconductor device which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the semiconductor device which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

  1, 61 Over temperature protection circuit, 2, 62 Fault detection circuit, 3, 3A to 3G drive circuit, 4, 4A, 4B Short circuit / over current protection circuit, 5 Logic gate, 51 Converter part, 52 Brake part, 53 Inverter part 63A, 63B Control power supply voltage drop protection circuit, 64 CPU, 101-102 semiconductor device, SW1, SWA-SWG switch element, D1, D11-D16, DA-DG diode, FC1, FC2 photocoupler, G1 comparator, G11 amplifier , G21A, G21B gate (error output circuit), IC1, IC2 control semiconductor integrated circuit, TR1, TR2 transistor, PS1, PS2, PS11, PS12 power supply, R1, R2, R11, R21 resistors.

Claims (14)

A switch element;
A drive circuit for supplying a voltage to the switch element;
An overtemperature protection circuit that detects an ambient temperature, and controls the voltage supply to the switch element by the drive circuit when the detected ambient temperature is higher than a reference temperature, and turns off the switch element;
A failure detection circuit that includes a wire and lowers the reference temperature when the wire peels off ,
The overtemperature protection circuit includes a first diode and a comparator,
The failure detection circuit includes the wire, a first resistor, and a second resistor,
One end of the wire is electrically connected to one end of the first resistor and one end of the second resistor, and the other end is connected to the other end of the second resistor and one end of the first diode. And electrically connected to the first input terminal of the comparator,
A semiconductor device , wherein a first voltage is supplied to the other end of the first resistor, and a second voltage is supplied to the other end of the first diode . The semiconductor device further includes a semiconductor chip on which one or a plurality of the switch elements are formed,
The semiconductor device according to claim 1, wherein a bonding portion of the wire is disposed at a substantially central portion of the semiconductor chip. The semiconductor device further includes:
An inverter unit including a plurality of the switch elements for driving an external device;
The semiconductor device according to claim 1, wherein the reference temperature is set to a temperature that is higher than a maximum value of the ambient temperature at which the inverter unit that is set in advance performs normal operation. The overtemperature protection circuit detects an ambient temperature, and when the detected ambient temperature is higher than the reference temperature, controls the voltage supply to the switch element by the drive circuit to turn off the switch element, 4. The semiconductor device according to claim 3 , wherein an error signal is output.   The semiconductor device according to claim 1, wherein the switch element is an IGBT.   The semiconductor device according to claim 1, wherein the switch element is a bipolar transistor.   The semiconductor device according to claim 1, wherein the switch element is an RC-IGBT.   The semiconductor device according to claim 1, wherein the switch element is a MOS-FET.   The semiconductor device according to claim 1, wherein the switch element is a thyristor.   The semiconductor device according to claim 1, wherein the switch element is a triac.   The semiconductor device according to claim 1, wherein the switch element is a GTO. The semiconductor device according to claim 1, wherein the switch element is a second diode. The semiconductor device includes:
An IGBT chip in which one or a plurality of IGBTs are formed as the switch elements;
A diode chip in which one or a plurality of second diodes are formed as the switch elements,
The semiconductor device according to claim 1, wherein the IGBT chip and the diode chip are modularized. The semiconductor device includes a semiconductor integrated circuit,
The semiconductors integrated circuit, said drive circuit, said the over-temperature protection circuit, a semiconductor device of claim 1 further comprising a said fault detection circuit.

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