SU842645A1 - Device for semiconductor device rejection - Google Patents

Description

one

This invention relates to cont. Lee-iameri ± ednoy technology and can be used in the control of radio electronic elements, such as semiconductor devices.

A device for grading semiconductor devices is known that contains a power supply unit, a pulse generator, a measuring resistance and a capacitor. An electronic key is connected in parallel with the resistance measuring devices and its input is connected to an ictulse generator, a threshold memory device whose output is connected to a capacitor Ll3.

A disadvantage of the known device is the low verification accuracy due to the fact that its results are significantly higher than the ambient temperature.

The closest in technical essence to the present invention is a device for screening semiconductor devices, containing a test device master jpiirHana, the first and Bxopd lt proe aerators (in which are connected to the corresponding outputs of the controlled and

reference semiconductor devices G2.

The disadvantage of this device is also low reliability of screening, which is due to the fact that the measured parameter of a semiconductor device depends on the ambient temperature, as a result of which errors may be made during the screening.

0

The purpose of the invention is to increase the reliability of the screening.

The goal is achieved by the fact that the screening device

S plukoprovodnikovyh devices, containing the unit of the test signal, connected to the outputs with the corresponding inputs of the monitored and the HALF of the semiconductor devices,

0 outputs of which are connected to the corresponding inputs of the first and second converters, a meter connected by an output to the input of a control unit connected by a first output through a feed and discharge unit to a second input of a controlled loop device, a dividing unit is inserted connected to the input of the corresponding outputs of the first and

0 second converters and second

control unit output and output. sokhody meter.

The drawing shows a block diagram of the device.

The device for grading semiconductor devices contains a monitored semiconductor device 1, the first parameter converter 2, dividing unit 3 and control 4, the supply and unloading unit 5, test signal setter b, reference, semiconductor device 7, meter 8, clamps 9 and 10 for mechanical connection semiconductor device 1, the second Converter 11 parameter.

The device for screening semiconductor devices operates as follows.

In the initial state, the setting device 6 of the test signal generates electrical signals, which are fed to the reference device 7 and to the terminal 9 for connecting the device under test 1. At the output of the parameter converter 11, there is no signal. At the output of the converter 2, a signal acts, the value of which is proportional to the parameter of the reference instrument 7. At the outputs of the 3-dividing unit and the meter 8, there are no signals. By connecting the monitored device 1 to the terminals 9 and 10 by the transducer 11, the parameter of the monitored device is converted into an electrical signal, which is fed to the dividing unit 3. On a command coming from the control block 4, the block 3 7 division implements the mathematical division operation. The voltage at the output of block 3 is equal to

eeeh - to-,

where u / ca has output voltages of converters 11 and 2;

K is a constant coefficient of proportionality.

The output voltage from block 3 is fed to the input of the meter 8, which is, for example, a comparison circuit with a predetermined reference value. From the output of the meter 8, the signal of the result of grading is fed to the input of the block 4, which generates the appropriate command for the block 5 of supply and load, which unloads the monitored slot 1.

Under production conditions, ambient temperature fluctuations occur. At the same time, the output voltages of converters 2 and 11

temperature dependent as follows

OA - K

, 2.)

(lt)

and K.

.

n / ll

where K „and K

-constant coefficients of proportionality;

- ambient temperature;

-increment;

/ and f

-temperature functions of the reference 7 and controlled 1 devices.

In case f (& r) 4 (), which is typical for devices of the same type 1 and 7 and takes place, for example, for semiconductor diodes, the output voltage of dividing unit 3 does not depend on the ambient temperature and is determined from the expression

As

to

-gch

14

Thus, due to the introduction of the division unit 3, the dependence of the voltage supplied to the meter 8 is reduced, at an ambient temperature that significantly increases the reliability of the screening.

Claims (2)

1. Author's certificate of the USSR W 438948, cl. G 01 R 31/26, 1975. 2. Authors certificate of the USSR 687419, cl. G 01 R 31/26, 1979 (prototype),