SU494628A1 - Method for determining temperature of electron transition - Google Patents

Description

This invention relates to electrical methods for measuring non-electrically magnitudes, in particular temperature.

The known method of determining the temperature of the p - "- junction of devices with avalanche characteristics, consisting in applying a current to the junction in the opposite direction, measured, and voltage, and determining the temperature by calculation. One; according to this method, temperature measurement is possible only if it is sufficiently long (pulses) (m 100 s). Due to the fact that the voltage measurement is performed after the completion of transient processes, it is possible to measure the temperature not earlier than 200-300 µs after the end of the reverse current pulse. In addition, an auxiliary yarn source is required.

The temperature of the proposed method is determined by the temperature-sensitive parameter, namely the voltage of the avalanche formation, the lipipeo, it is from its temperature over the entire range of operating temperatures. The p-j junction temperature is determined at the end of the reverse current pulse, more precisely, at the time of the current droop when exposed to pulses of almost any duration, including shorter than 100 MP s, did not resort to the use of auxiliary current. Thus, the measurement is made at the moment when

the transition temperature is practically “not different from the maximum reached as a result of the action of a power pulse.

FIG. Figure 1 shows the electrical measurement scheme.

The circuit contains a generator of a reverse current, an oscillator / im., A diode limiter 2, a two-beam oscilloscope L and a device under study 4.

FIG. 2 is the form of voltage and current pulses recorded with a dual-beam oscilloscope, where:

and - im.pulse voltage;

(b) the upper part of the voltage pulse, corresponding to the section of the avalanche growth of the current, isolated by means of a diode limiter;

in - current pulse.

The temperature is determined as follows.

With the help of short-circuit current pulses of a certain amplitude / 1, the temperature coefficient of an 11 avalanche formation (TKN) is determined.

and ,, - and,

  , -,

(1 l

where and

avalanche stress

/ 1 at temperature / s

L, 3 - 1fat avalanche formation

At temperature / 2, the device under test, p a reverse current pulse, after which it is necessary to determine the temperature of the junction, is recorded using a two-beam oscilloscope simultaneously a current pulse (Fig. 2, b) and a pulse on. yarn (fit. 2, a), or rather, the upper part of the pulse (Fig. 2.6), selected with the help of a diode limiter.

The shape of the selected voltage pulse (Fig. 2, b) is determined by the shape of the current pulse, the heating of the structure under the influence of the MO. Pulse of the current and the value of the TKN. As a result, the same level of tol / 1 corresponds to two different values of lamination: L / i at the beginning and t / 2 at the end of the pulse (Fig. 2, b, 2, e). The difference between these voltages Af / / 2-f / i is directly proportional to the TKN and the temperature difference B "at the beginning and at the end of the current pulse.

The current level / i is chosen, depending on the shape and duration of the power pulse so that during TI from the beginning of the current pulse to the level /; The heating structure of the transition could be neglected (usually, the value of / i does not exceed 10–20% of the amplitude of the reverse current pulse). Then the temperature of the structure at the beginning of the current pulse (at the time of TI) can be considered equal to the temperature of the instrument housing .or.

Thus, the temperature of the p - «- junction (Gam) at the end of the current pulse is determined from the ratio

T

 trp RKN

The method can be used with any form of a power pulse, and the temperature is determined directly in the working circuit.

Subject invention

C. A method for determining the temperature of an electrically-hole transition of an instrument with avalanche characteristics and for switching on the p-junction current in the reverse direction and measuring the voltage over which the temperature is measured, in that In order to increase the accuracy of measurements, the p-l-l transition serves as a pulse, and the voltage value is determined at the time of its maximum value by the shape of the extracted voltage pulses and the applied -pulses of the current.