JPH0743409B2 - Method for measuring junction temperature of insulated gate bipolar transistor - Google Patents

Description

The present invention relates to a junction temperature measuring method for an insulated gate bipolar transistor in which a bipolar transistor and a MOSFET for driving the bipolar transistor are integrated together.

[Conventional technology]

When determining the rated current of the semiconductor element, it is necessary to know the characteristics such as the conduction resistance and thermal resistance inside the semiconductor element body.
To evaluate the thermal resistance, it is necessary to measure the junction temperature in the semiconductor body. In the case of a diode, the junction temperature of the semiconductor device is measured by utilizing the temperature dependence of the forward voltage drop between the cathode and the anode. For bipolar transistors, the forward voltage drop at the PN junction between the base and emitter is used for measurement. 2 (a), (b), (c)
Shows the measurement procedure. A power supply 22 is connected between the base and collector of a bipolar transistor 21, and a measurement current power supply 24 is connected to the emitter via a resistor 23.
A forward measurement voltage V _BE1 between the base and emitter at room temperature is measured by applying a measurement current to 21 so that the temperature does not rise (Fig. A). Then, the power supply 25 is connected between the base and the emitter to flow a predetermined current to raise the junction temperature (Fig. B), and then the forward voltage drop V _BE2 between the base and the emitter is again made in the same manner as in Fig. A. Measure (Figure C). Since the difference ΔV _BE between V _BE1 and V _BE2 thus obtained depends on the junction temperature after the rise, the junction temperature can be measured from it. This makes it possible to know the rise in the junction temperature when a predetermined power is applied to the element. In the case of a field effect transistor, the junction temperature is measured by utilizing the temperature dependence of the forward voltage drop of the parasitic diode generated between the source and the drain.

[Problems to be solved by the invention]

The insulated gate bipolar transistor has the structure shown in FIG. In this device, the N-type silicon substrate 31
P ⁺ layer 32 is provided on one side, and P layer 33 is included in the remaining N ₋ layer 31.
However, a deeper P ⁺ layer 34 is further provided in the center thereof to form a PNP bipolar transistor. Also,
Two N ⁺ layers 35 formed on the surface layer of the P layer 33, an N ⁻ layer 31 surrounding the P layer 33, and a multi-layered structure provided on the surface of the P layer 33 between them with an oxide film 36 interposed therebetween. The gate 37 of crystalline silicon constitutes the NOSFET. The gate 37 has a gate terminal 41 drawn out through an insulating film 38 covering it, the P ⁺ layer 32 has an emitter terminal 42 via a contact metal electrode 39, and the P ⁺ layer 34 and the N ⁺ layer 35 have a contact metal electrode. Collector terminal 43 through 40
Are connected. However, since this device has no base terminal of the bipolar transistor and no drain terminal of the MOSFET, it is necessary to measure the junction temperature using the temperature dependence of the forward voltage drop of the diode like the bipolar transistor or FET described above. I can't.

An object of the present invention is to provide a method for measuring the junction temperature of an insulated gate bipolar transistor by solving the above problems.

[Means for solving problems]

In order to achieve the above-mentioned object, a method for measuring an insulated gate bipolar transistor according to the present invention is to connect a power supply between a gate terminal and an emitter terminal of an insulated gate bipolar transistor to apply a voltage to the gate and a collector terminal.・ A variable current connected between the gate terminals is used to flow a measured current adjusted to the extent that the temperature of the device is not increased between the collector and emitter terminals to reduce the voltage drop V _CE1 between the collector and emitter terminals at room temperature. A first means for measuring; a second means for connecting a voltage source and a current source between a collector terminal and an emitter terminal to set an applied voltage and an output current to the device to raise the junction temperature of the device; After performing the second means, the first means is again performed to measure the voltage drop V _CE2 between the collector terminal and the emitter terminal. From the third means, the first means and the third means, ΔV _CE = V _CE1 −V _CE2 is obtained, and the junction temperature when power is applied is determined from the relationship between V _CE and the junction temperature measured in advance.

[Action]

If the relationship between the voltage drop and the junction temperature when the current is applied between both current terminals of the insulated gate bipolar transistor is obtained in advance, the junction temperature can be known easily by measuring the voltage drop.

〔Example〕

FIGS. 1 (a) to 1 (c) show the measurement procedure of one embodiment of the present invention. First, the power supply 2 is connected to the gate terminal 11 and the emitter terminal 12 of the insulated gate bipolar transistor to apply a voltage to the gate, and to the extent that the temperature of the element adjusted by the variable resistor 3 connected to the collector terminal 13 is not raised. Adjusted measured current is applied to collector terminal 13 and emitter terminal 1
_Flow between two terminals and measure the voltage drop V _CE1 between both terminals at room temperature (Fig. A). Next, the voltage source 4 and the current source 5 are connected between the collector terminal 13 and the emitter terminal 12 to set the voltage applied to the device 1 and the output current (FIG. B). After increasing the junction temperature by this, the measurement current is made to flow again by the power supply 2 as in the case of Fig. A, and the voltage drop V between the collector terminal 13 and the emitter terminal 12
Measure _CE2 (Fig. C). Here, ΔV _CE = V _CE1 −V _CE2 is obtained, and the junction temperature at the time of applying power is obtained from the previously measured relationship between V _CE and the junction temperature.

〔The invention's effect〕

According to the present invention, the junction temperature is easily measured from the temperature dependence of the voltage drop between the emitter terminal and the collector terminal of the insulated gate bipolar transistor having no base terminal. It can be effectively applied to the determination of rated power.

[Brief description of drawings]

1 (a) to 1 (c) are circuit diagrams showing the measurement procedure of one embodiment of the present invention, and FIGS. 2 (a) to 2 (c) are circuit diagrams showing the junction temperature measurement procedure of the bipolar transistor, and FIG. The figure is a cross-sectional view of an insulated gate bipolar transistor. 1: Insulated gate bipolar transistor, 12: Emitter terminal, 13: Collector terminal.

Claims (1)

[Claims] 1. An insulated gate bipolar transistor is connected to a power supply between a gate terminal and an emitter terminal to apply a voltage to the gate, and a variable resistor connected between the collector terminal and the gate terminal raises the temperature of an element to be heated. The first means to measure the voltage drop V _CE1 between the collector terminal and the emitter terminal at room temperature by flowing the measured current adjusted to the extent that it is not allowed to flow between the collector terminal and the emitter terminal. A second means for connecting a power source to set an applied voltage and an output current to the device to raise the junction temperature of the device; and after performing the second means, again performing the first means to collect collector and emitter terminals. third means for measuring the voltage drop V _CE2 between, seeking ΔV _CE = V _CE1 -V _CE2 from the first means and third means, when power is applied from the relationship between the junction temperature and the V _CE which is previously measured Junction temperature measuring method of the insulated gate bipolar transistor, characterized in that to obtain a slip temperature.