JPH03101146A - Ic inspection apparatus - Google Patents

Abstract

PURPOSE:To correct, at an actual measurement, an error included in an ON resistance value of a changeover device and to enhance the measuring accuracy by a method wherein, when a plurality of measuring probes are brought into contact simultaneously and a measurement is executed by changing over them one after another, the error is measured and stored in advance. CONSTITUTION:An object 5 to be measured such as an IC, an IC-mounted circuit or the like is measured by using a plurality of measuring probes 7. They are previously brought into contact with a short circuit board 6 as a dummy; a constant current from a constant-current source 1 is set to ON via a changeover device 4; an impressed voltage is measured by using a voltmeter 2; an ON resistance value of the changeover device 4 can be found from a voltage value/a current value by using a computer 3. A characteristic value which has integrated conditions of individual terminals and the changeover device is stored in the computer 3; then, a product of said ON resistance value and a constant current value is substracted from a voltage value measured when a voltage is applied to the object 5 to be measured. Thereby, it is possible to find a true voltage value applied.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC inspection device for checking open and short circuits in bonding and soldering of ICs.

[Summary of the invention]

The present invention provides an IC inspection device that checks the open and short states of IC bonding and soldering using a stylus, and sets the value of the ON resistance of the switch of the IC inspection device to a reference value by connecting it in advance with a short plate. By measuring and storing it in the computer,
In actual measurements, measurement accuracy is improved by correction.

[Conventional technology]

Conventionally, as shown in the block diagram of FIG.
When checking the bonding etc. of the mounted circuit under test 5, the constant current from the constant current source 1 is applied at that time by sequentially switching the plurality of terminals of the IC or the circuit 5 on which the IC is mounted using the switching device 4. The voltage was measured with voltmeter 2, and the computer 3 checked for open and short circuits.

(Problem to be Solved by the Invention) However, the conventional IC testing device uses a switching device 4 made of a semiconductor analog switch, and measures the voltage including its ON resistance, so the measurement accuracy of the voltage for each terminal is low. It was rough.

Therefore, in order to solve these conventional drawbacks, the present invention aims to eliminate the influence of the ON resistance of the switching device and improve measurement accuracy.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides an I method that simultaneously probes a plurality of measuring needles and sequentially switches the measuring needles for measurement.
In the C test device, before measuring the device to be measured, a short plate is provided which is touched under the same conditions as the device to be measured, the ON resistance value of the short circuit is memorized by the short plate, and the memorized resistance value is used to measure the device to be measured. The problem is solved by correcting each measurement condition of the measurement element.

[Effect]

By measuring and storing the error included in the ON resistance value of the switching device 4 of the IC inspection machine configured as above in advance, it is possible to perform measurements that are not affected by the ON resistance of the switching device 4. .

〔Example〕

Embodiments of the present invention will be described below based on the drawings. In the block diagram of FIG. 1, a plurality of measurement needles 7 measure an object 5 such as an IC or a circuit equipped with an IC. At this time, a short plate 6 is provided as a dummy for making contact under the same conditions as the previous stylus condition, and the connection is made. Then, the constant current generated from the constant current source 1 is turned on via the switch 4.
Have them pour it in.

The voltage thus applied is measured by the voltmeter 2, and the computer 5 turns on the switch 4 based on the voltage value divided by the current value.
Resistance values can be determined, which are switched for all terminals by a switch 4, and a characteristic value that combines the conditions of each terminal and switch is stored in a computer 5. Next, in order to measure the object to be measured, connect the IC or the circuit 5 equipped with the IC with a probe, turn on the switch 4 by operating the switch 4 in the same way as above, and measure the generated voltage with the voltmeter 2. Then, it is corrected by subtracting the result of multiplying the ON resistance value and the constant current value from the voltage value measured by the computer 5.
It becomes possible to obtain the true voltage value applied to the circuit 5 equipped with a C or an IC.

(Effects of the Invention) As described above, the present invention has the effect of dramatically improving measurement accuracy because measurement can be performed without being affected by the ON resistance of the switching device 4.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an IC testing device according to the present invention, and FIG. 2 is a block diagram of a conventional IC testing device. 1... Constant current source 2... Voltmeter 3... Computer 4... Switcher 5... IC or circuit equipped with IC (object to be measured) 6...
・Short plate 7...Measuring needle or more

Claims (1)

[Claims] In an IC testing device that stylis multiple measuring needles at the same time and sequentially switches the measuring needles for measurement, before measuring the device to be measured, a short plate is provided to stylus the stylus under the same conditions as the device to be measured. An IC inspection apparatus characterized in that an ON resistance value caused by a short circuit is stored, and each measurement condition of the device under test is corrected using the stored resistance value.