JPH05164812A - Direct current testing device for ic tester - Google Patents

Abstract

PURPOSE:To provide a direct current testing device for an IC tester capable of performing a direct current characteristics test of IC at high speed and steadily. CONSTITUTION:A direct current testing device comprises a power supply current measurement means 1 connected to power supply a power supply connecting means 11 for connecting said power supply current measurement means 1 to an IC 15, to be measured, an IC earth means 21 for connecting the IC 15 to be measured to an earth means 2, a plural number of switching means 3 for conecting respective output terminals of the IC 15 to be measured to corresponding direct current measurement means 4, allowable maximum current preset means 5 for the IC 15 to be measured a measurement condition setting means 6. Furthermore it comprises a measured IC output terminal simultaneous connection means 7 for switching on all the switching means 3 simultaneously, an output terminal number determination means 8 for determining the number of output terminals of the IC 15 to be measured by an approximate method within such a range as the current flowing in the IC 15 to be measured doesn't exceed the allowable maximum current, means 9 for switching on the same number of the switching means as the prescribed number of output terminals, and a direct current test repeat carrying means 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an IC tester (hereinafter referred to as IC
Called a tester. ) For improving DC test equipment. In particular, the present invention relates to an improvement for the purpose of providing a DC test device for an IC tester capable of performing a DC characteristic test of an IC at high speed and stably.

[0002]

2. Description of the Related Art In order to test the function of an IC, it is necessary to measure various characteristics of the IC using an IC tester. I
Among the C tests, the DC characteristic test, which is performed to confirm the input / output voltage and current values of the IC, is the test with the largest number of measurements. To reduce the total test time of the IC, this DC It is necessary to perform the characteristic test quickly and stably.

Below, a description will be given of a test device for an IC tester which has been conventionally used for a direct current characteristic test of an IC and a test method performed by using this test device. FIG. 2 is a block diagram of an IC tester test apparatus according to the prior art.

In FIG. 2, reference numeral 3 is a switching means connected to each of a plurality of output terminals of the IC 15 to be measured, and reference numeral 4 is a direct current measuring means connected to each of the switching means 3. The DC measuring means 4 includes a voltage measuring means, a current measuring means, a first selecting means for selecting one of the voltage measuring means and the current measuring means, a constant voltage power source, a constant current power source, and these constant voltage power source / constant current power source. The second to choose one of
And selecting means. 12 is the above DC measuring means 4
Execution of the measurement conditions (selection in the first and second selection means, voltage values of the constant voltage power supply and constant current power supply)
This is a control means for setting a current value) and supplying a power supply voltage to the DC measuring means 4.

Next, a test method using the above test apparatus will be described. In the output voltage measurement, which is one of the measurements in the DC characteristic test, a predetermined load current is supplied from each of the plurality of output terminals of the IC 15 to be measured, or a predetermined current is supplied to each of the plurality of output terminals. First, the output voltage is measured to check whether or not a predetermined criterion is satisfied. In the prior art, all of the switching means 3 of the above-described test device are turned on at the same time during measurement, and a plurality of output terminals are simultaneously measured.

As a result, the test time is greatly shortened as compared with the case of the DC test apparatus which was previously used, in which one or two DC measuring means were sequentially connected to the output terminal of the IC to be measured. It was

[0007]

However, when the DC test apparatus according to the prior art is used, when the number of terminals to be measured is large, the total amount of load current flowing through the IC to be measured increases, and the voltage due to this load current increases. There is a drawback that the drop of the power supply voltage and the rise of the ground level due to the drop exceed the allowable limit, and as a result, it becomes impossible to accurately measure the output voltage.

If all the measurement terminals are divided into a plurality of groups and the measurement is carried out several times, the load current in one measurement is reduced, so that the decrease of the power supply voltage and the increase of the ground level should be suppressed within the limit. However, it takes a lot of time for trial and error until a reasonable number of divisions is found, and it becomes difficult to shorten the test time.

An object of the present invention is to eliminate the above-mentioned drawbacks, and to provide a DC test apparatus for an IC tester, which can carry out a DC characteristic test of an IC at high speed and stably.

[0010]

The above object is to provide a power source current measuring means (1) connected to a power source, and a power source connecting means for connecting the power source current measuring means (1) and the IC to be measured (15). (11), the IC to be measured (15) and the grounding means (2)
IC grounding means (21) for connecting to and the IC to be measured
A plurality of switching means (3) connecting each of the output terminals of (15) to the corresponding DC measuring means (4), and an allowable maximum current setting means for setting an allowable maximum current of the IC to be measured (15). (5), measurement condition setting means (6) for setting measurement conditions, IC output terminal simultaneous connection means (7) for simultaneously turning on all of the plurality of switching means (3), and the above-mentioned Measured IC output terminal number determining means (8) for determining the number of output terminals of the measured IC (15) within a range in which the current flowing in the measured IC (15) does not exceed the set allowable maximum current. ) And a means (9) for turning on the switching means (3) by the determined number of IC output terminals to be measured.

[0011]

In the DC tester for IC tester according to the present invention, each of the output terminals of the IC to be measured is connected to the DC measuring means through the switching means, and the power supply current is measured when measuring the DC characteristics. While comparing this power supply current value with the set maximum allowable current value of the IC to be measured, the above switching means is turned on or off based on the approximation method, and the above power supply current changes the maximum allowable current of the IC to be measured. The maximum number of output terminals within the range that does not exceed is automatically determined, and simultaneous measurement is performed on these determined terminals, so the optimum number of simultaneous measurement terminals is automatically determined and measured easily. Is executed. Therefore, if the DC test apparatus according to the present invention is used, the test time can be greatly shortened.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A direct current test apparatus for an IC tester according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a DC test apparatus for an IC tester according to this embodiment. Referring to FIG. 1, reference numeral 1 is a power supply current measuring means, and 11 is a power supply connecting means for connecting the power supply current measuring means 1 and the IC 15 to be measured. 2 is a grounding means and 21 is the IC to be measured
IC grounding means for connecting 15 and the grounding means 2. Reference numeral 22 is a ground current measuring means provided between the ground means 2 and the IC ground means 21. Reference numeral 3 is a switching means for connecting each output terminal of the IC to be measured to the corresponding DC measuring means 4. The DC measuring means 4 is a voltage measuring means, a current measuring means, a first selecting means for selecting one of these voltage measuring means / current measuring means, a constant voltage power source, a constant current power source, and these constant voltage power source / constant current. And a second selection means for selecting one of the power supplies. Reference numeral 5 is a maximum allowable current setting means for setting the maximum allowable current of the IC 15 to be measured. Reference numeral 6 is a measurement condition setting means for setting measurement conditions (selection by the first and second selection means, setting of voltage values / current values of the constant voltage power supply / constant current power supply, etc.). Reference numeral 7 designates IC output terminal simultaneous connection means for measuring all the switching means 3 which are turned on at the same time.
8 is input with the measured power supply current / ground current and the set allowable maximum current, and the current actually flowing in the IC 15 to be measured is set using the approximation method. It is means for determining the number of output terminals of the IC to be measured 15 for determining the number of output terminals of the IC 15 to be measured within a range not exceeding the maximum allowable current. Reference numeral 9 is a means for turning on the switching means 3 based on the output of the measured IC output terminal number determining means 8. 10 supplies the power supply voltage to the above DC measuring means 4,
Further, in response to the output of the measuring condition setting means 6, the selection by the first and second selecting means of the DC measuring means 4 and the setting of the voltage value / current value of the constant voltage power source / constant current power source are executed, Repeat the above DC test of IC15 to be measured,
This is a means for repeatedly executing a DC test that outputs the measurement result.

Next, the operation of the DC test apparatus according to this embodiment will be described. First, after connecting a DC test device to each terminal of the IC 15 to be measured as shown in FIG. 1, all the switching means 3 are turned on by using the IC output terminal simultaneous connection means 7 to perform a no-load test. Run. Next, in the load test, first, half of the total number of switching means 3 are turned on, and these switching means 3 are turned on.
The corresponding DC measuring means 4 is connected to the IC 15 to be measured. A predetermined load current is applied to each of the output terminals of the IC 15 to be measured to which the DC measuring means 4 is connected. At this time, the power supply current measured by the power supply current measuring means 1 or the ground current measured by the ground current measuring means 22 or the ground current measured by the ground current measuring means 22 must exceed the maximum allowable current of the IC 15 to be measured. For example, half of the remaining switching means are additionally turned on. If it is exceeded, half of the switching means 3 which have been turned on are turned off. After that, the same procedure as described above is repeated to obtain the convergent solution (the maximum number of output terminals within the range in which the power supply current or the ground current does not exceed the maximum allowable current of the IC 15 to be measured). This converged solution is stored and used for the next measurement. Further, the DC characteristic measurement is executed for each number of output terminals of the converged solution obtained as described above.
Since all the above-mentioned operations are automatically executed, the DC characteristic test can be performed quickly and stably.

The above method for determining the optimum number of terminals is only an example, and the optimum number of terminals may be determined by using another approximate calculation method.

[0016]

As described above, the IC according to the present invention
In the DC tester for a tester, a DC measuring means is connected to each of the output terminals of the IC to be measured through a switching means, and at the time of measuring the DC characteristics, the approximation method is used to actually flow to the IC to be measured. The number of output terminals of the IC to be measured within the range in which the current does not exceed the maximum allowable current set by the maximum allowable current setting means is determined by the IC output terminal number determining means, and the determined output of the IC to be measured is determined. The above switching means is turned on for the number of terminals, the measurement conditions are set based on the output of the measurement condition setting means, and the DC characteristic test is repeatedly executed. It is possible to determine and measure in a short time.

Therefore, the present invention can provide a DC test device for an IC tester, which can perform a DC characteristic test of an IC at high speed and stably.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a DC test device for an IC tester according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a DC test device for an IC tester according to a conventional technique.

[Explanation of reference numerals] 1 power supply current measuring means 2 grounding means 3 switching means 4 direct current measuring means 5 allowable maximum current setting means 6 measuring condition setting means 7 measured IC output terminals simultaneous connection means 8 measured IC output terminal number determining means 9 Means for turning on the switching means 10 Means for repeatedly executing DC test 11 Means for connecting power supply 12 Control means 15 IC to be measured 21 IC grounding means 22 Ground current measuring means

Claims (1)

[Claims] 1. A power supply current measuring means (1) connected to a power supply, the power supply current measuring means (1) and an IC to be measured (1)
5) a power source connecting means (11) for connecting to
IC grounding means (21) for connecting C (15) to the grounding means (2) and a plurality of switching circuits for connecting the output terminals of the IC under test (15) to the corresponding DC measuring means (4). Means (3), maximum allowable current setting means (5) for setting the maximum allowable current of the IC to be measured (15), measurement condition setting means (6) for setting measurement conditions, and the plurality of switching means ( IC output terminal simultaneous connection means (7) for simultaneously turning on all of 3), and the IC to be measured.
A measured IC output terminal number determining means (8) for determining the number of output terminals of the measured IC (15) within a range in which the current flowing in (15) does not exceed the set maximum allowable current; A DC test device for an IC tester, comprising: means (9) for turning on the switching means (3) by the determined number of IC output terminals to be measured.