Semiconductor device and fault detecting method

Patent metadata

Field	Value
Publication number	US-2017003337-A1
Application number	US-201615098052-A
Country	US
Kind code	A1
Filing date	Apr 13, 2016
Priority date	Jun 30, 2015
Publication date	Jan 5, 2017
Grant date	—

Abstract

An obtained margin is smaller than a margin to be kept for a fault period predicted by life prediction based on a power cycle test, extending a maintenance cycle for replacement and so on. A method of detecting a fault of a semiconductor device including a power device mounted on a metal base and a drive circuit for driving the power device, the method detecting a fault of the semiconductor device beforehand based on an increase in thermal resistance between the metal base and the power device. A state of the power device is measured immediately before and after the power device is driven by the drive circuit. A temperature difference of the power device before and after driving is calculated according to the result of measurement. An increase in thermal resistance between the metal base and the power device is detected based on the temperature difference and an amount of electricity inputted to the power device in the driving period, and a fault of the semiconductor device is detected beforehand according to the increase.

First claim

What is claimed is:

1 . A semiconductor device comprising:
a power device mounted on a metal base; a drive circuit for driving the power device; a measuring circuit that measures a state of the power device immediately before and after a driving period in which the drive circuit drives the power device; and a control circuit that detects, according to a result of the measurement by the measuring circuit, an increase in thermal resistance between the metal base and the power device based on a temperature difference before and after the driving of the power device and input power to the power device in the driving period.

2 . The semiconductor device according to claim 1 ,
wherein the control circuit causes the drive circuit to perform the driving on a condition that the input power is set at a predetermined value.

3 . The semiconductor device according to claim 2 ,
wherein the drive circuit drives the power device in response to a driving signal with pulse width modulation, the condition is specified by a parameter including a duty ratio of the pulse width modulation, and the input power is calculated based on a power supply voltage applied to the power device, an amplitude and a frequency of the driving signal, and the duty ratio.

4 . The semiconductor device according to claim 1 ,
wherein the measuring circuit measures a voltage applied to the power device and a current passing through the power device in the driving period, and supplies a measurement result to the control circuit, and the control circuit calculates the input power from the measurement result.

5 . The semiconductor device according to claim 4 ,
wherein the current is an on current when the power device is turned on, and the voltage includes an on voltage and an off voltage of the power device.

6 . The semiconductor device according to claim 1 ,
wherein the measuring circuit includes a temperature sensor that is provided in or next to the power device, and the temperature difference is calculated from a value measured by the temperature sensor.

7 . The semiconductor device according to claim 2 ,
wherein the predetermined value is a first predetermined value, wherein the measurement of the state of the power device by the measuring circuit immediately before and after the driving period involves additional driving of the power device by the drive circuit on a condition that the input power is set at a second predetermined value smaller than the first predetermined value, and wherein the control circuit calculates the temperature difference based on a measurement result of the state of the power device by the measuring circuit immediately before and after the driving period.

8 . The semiconductor device according to claim 1 ,
wherein the power device is an insulated gate bipolar transistor.

9 . The semiconductor device according to claim 1 ,
wherein the control circuit detects that the increase in thermal resistance has reached at least a predetermined value, and then the control circuit reduces capability of driving the power device by means of the drive circuit.

10 . The semiconductor device according to claim 9 ,
wherein the power device is an insulated gate bipolar transistor, the drive circuit drives, for the power device, a gate electrode of the insulated gate bipolar transistor in response to a driving signal with pulse width modulation, and wherein the control circuit detects that the increase in thermal resistance has reached at least the predetermined value, and then the control circuit reduces at least one of a duty ratio of the pulse width modulation, a frequency, and an amplitude of the driving signal so as to reduce the capability of driving the power device by means of the drive circuit.

11 . A method of detecting a fault of a semiconductor device comprising a power device mounted on a metal base and a drive circuit for driving the power device,
the method comprising the steps of: measuring a state of the power device immediately before and after a driving period in which the drive circuit drives the power device; detecting, according to a result of the measurement, an increase in thermal resistance between the metal base and the power device based on a temperature difference before and after the driving of the power device and input power to the power device in the driving period; and detecting the fault of the semiconductor device beforehand based on the increase in thermal resistance between the metal base and the power device.

12 . The method of detecting a fault according to claim 11 ,
wherein the driving is performed on a condition that the input power is set at a predetermined value, and wherein the increase in thermal resistance is detected based on the temperature difference and the predetermined value.

13 . The method of detecting a fault according to claim 12 ,
wherein the drive circuit drives the power device in response to a driving signal with pulse width modulation, the condition is specified by a parameter including a duty ratio of the pulse width modulation, and the amount of electricity is calculated based on a power supply voltage applied to the power device, an amplitude and a frequency of the driving signal, and the duty ratio.

14 . The method of detecting a fault according to claim 11 ,
wherein a voltage applied to the power device and a current passing through the power device are measured in the driving period, and the input power is calculated from a result of the measurement.

15 . The method of detecting a fault according to claim 14 ,
wherein the current is an on current when the power device is turned on, and the voltage includes an on voltage and an off voltage of the power device.

16 . The method of detecting a fault according to claim 11 ,
wherein the semiconductor device includes a temperature sensor that is provided in or next to the power device, and the temperature difference is calculated from a value measured by the temperature sensor.

17 . The method of detecting a fault according to claim 12 ,
wherein the predetermined value is a first predetermined value, Wherein the measurement of the state of the power device by the measuring circuit immediately before and after the driving period involves additional driving of the power device by the drive circuit on a condition that the input power is set at a second predetermined value smaller than the first predetermined value, and wherein the temperature difference is calculated based on a measurement result of the state of the power device immediately before and after the driving period.

18 . The method of detecting a fault according to claim 11 ,
wherein the power device is an insulated gate bipolar transistor.

Assignees

• Renesas Electronics Corp

Inventors

• Bito Katsutoshi
• Iijima Daisuke
• Takehara Yuji

Classifications

• H10W90/754

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W90/734

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W90/724

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W72/352

  comprising metals or metalloids, e.g. solders · CPC title