JPH0954143A - Parallel-connected voltage generators in semiconductor testing apparatus and contact test method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an apparatus and a method for a contact test, which confirm that a voltage is supplied normally to a DUT power-supply pin from every voltage generator when a plurality of voltage generators which supply the voltage to the DUT power-supply pin are connected in parallel to be used. SOLUTION: Switching means 8, 9,... (n) which cut off an output end are installed individually at voltage generators. A controller 23 which controlls the switching means to be sequentially switched at the time of contact check for the contact check, is installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact tester for ensuring electrical connection when a plurality of voltage generators are connected in parallel in an IC tester.

[0002]

2. Description of the Related Art When testing the electrical characteristics of an IC device to be measured (hereinafter referred to as a DUT) with an IC tester, the current capacity of a power supply sometimes required (for example, 500).
There is a case where the device whose mA) is insufficient with only one voltage generator. In that case, multiple voltage generators should
Supply power by connecting in parallel at the power pin ends. With respect to this power supply, it is necessary to check and confirm that the voltage generators that are operated in parallel are surely supplying the DUT.

FIG. 3 shows a DUT 17 having two voltage generators VS1 and VS2, which are plural in number according to the prior art.
It is a circuit configuration that is used by connecting in parallel with. The above-mentioned circuit configuration is composed of voltage generators VS1 and VS2 each having a built-in contact check circuit 25 and 26 and connected in parallel, a controller 33 and a DUT 17, and its input / output wiring terminals. In addition, contact check circuits 25 and 26
Are switches 5 and 6 which are contact points of a reed relay or the like and A /
It is composed of D converters 27 and 28. During device testing, the switches 5 and 6 close both contacts and supply power to the DUT as an original voltage generator. On the other hand, at the time of contact check, this is opened and resistors R41 and R42 are
A minute current is applied via the
Contact check is performed by measuring the voltage at the DUT power supply pin end at 7 and 28.

In the example of FIG. 3, voltage generators VS1 and V1
There are four terminal blocks (plug-in or crimp terminal blocks) as output terminals of S2, and there are four connection points A, B, C,
There is D. These four wires are connected at the contact end of the DUT power supply pin via a relay connector on the way from this terminal to the DUT.

The controller 33 is a D / A converter 3
The output voltage is controlled by 1, 32 and the switches 5, 6 are controlled to be opened / closed, and the voltage measurement values VM20, VM21 which are feedback signals.
Is measured by the A / D converters 27 and 28, and it is checked whether or not the connection state with the DUT 17 is normal.

By the way, in the device test, D
All pin contact checks between the UT and device socket are performed. At this time, input pins other than power pins,
The I / O pins are ISVM (curr) of the DC test unit.
ent I source voltage measure) is sequentially switched to interrupt the DUT pin, and the contact check is performed by this current applied voltage measurement function. The contact check is usually performed at the beginning of a test in which the DUT is mounted, and is a function of detecting and confirming whether or not the IC socket or contactor of each pin of the DUT is electrically connected.

On the other hand, for the DUT power supply pin, this I
Some semiconductor test equipment does not have a switching circuit that interrupts the SVM. Therefore, the voltage generators VS1 and VS2
Is equipped with a contact check function to check the contact of power pins.

The operation of contact check in the case of one voltage generator VS1 will be described with reference to FIG. DUT
The TTL or CMOS device usually exhibits a diode characteristic by a PN junction, and when a negative voltage is applied to the power supply pin, it is clamped to about 0.6V. Utilizing this, the contact check of the electrical connection state from the output end of the voltage generator VS1 to the DUT power supply pin is performed. Therefore, it is checked whether it is normal including the connection state of the power supply cable.

For this reason, the switch 5 is opened and the DU
The voltage is applied to the DUT at a voltage setting of about -1 V by the D / A converter 31 via the protection resistor R41 in series with T. In this state, the A / D converter 27 measures. First, D
When the contact of the UT power supply pin is poor, it is measured as a voltage value of -1 V, and it can be seen that the contact is defective. Second
When measured as a voltage value around -0.5V,
It means that the diode characteristic of the DUT is detected.
It can be seen that the power pin is in an electrically normally connected state. Thirdly, when measured as a voltage value of about 0 to -0.2V, the output terminals 12 and 11 may not be connected properly, or the connection system such as a relay connector on the way from this output terminal to the DUT power supply pin. It can be seen that there is poor contact, disconnection, and cable breakage. In this way, the contact check can be determined.

Next, referring to FIG. 3, the voltage generator VS1,
The operation of contact check when two VS2s are connected in parallel will be described. When the two voltage generators are connected in parallel, the controller 33 may not be able to normally determine the contact check because it may not be able to detect whether the connection state of the cable or the like is normal. That is, the switch 5,
Open 6 and connect in series to the DUT a resistor R41 for protection,
The voltage is set to about -1 V by the D / A converters 31 and 32 via R42 and applied to the DUT. In this state, the A / D converters 27 and 28 similarly measure.

The following description will be made assuming a combination in which the measured values at the A / D converters 27 and 28 are respectively -1V, 0V and -0.5V. First, the measured values of the A / D converters 27 and 28 are both -1V or 0V and -1.
In the case of V, a defective contact state of the DUT power supply pin is detected. Secondly, when the measured values of the A / D converters 27 and 28 are both 0V, the contact state of the DUT power supply pin is indefinite, and a defect in the supply system of the voltage generators VS1 and VS2 is detected. Thirdly, the A / D converter 27,
28 measured value is 0V and -0.5V or both are -0.5
In the case of V, the normal contact state of the DUT power supply pin can be detected. However, although one defect of the sensing cable system can be detected, it is not clear because it cannot be specified whether both supply sides of the voltage generators VS1 and VS2 are in the connected state.

As described above, when two voltage generators are connected in parallel, the controller 33 cannot detect whether the connection state of the cable or the like is normal, so the contact check is normally judged. It causes a problem that can not be done, D
There is a case where the UT supply current is disturbed and the power supply voltage is lowered to prevent normal device testing. 2 like this
In parallel operation of more than one unit, the contact check including each voltage generator cannot be detected normally.

[0013]

As described above, when a plurality of voltage generators are connected in parallel, a contact check including whether the connection state of cables or the like is normal occurs, which causes a problem. In some cases, an erroneous power source is supplied to the DUT, which is a factor in deteriorating the measurement quality of the semiconductor test apparatus, which is a problem in use.

Therefore, the problem to be solved by the present invention is as follows.
When using multiple voltage generators connected to the DUT power supply pin in parallel, use each voltage generator
It is an object to realize a contact test device and a test method for confirming that power is normally supplied to a power pin.

[0015]

In order to solve the above-mentioned problems, in the structure of the present invention, each voltage generator is provided with opening / closing means (switches) 8 and 9 to n for disconnecting the output end thereof, which is used at the time of contact check. The controller 33 is provided with a controller 33 for sequentially checking the opening and closing of the switches to check the contacts. As a result, in a voltage generator that has the contact check circuit 4 and is connected in parallel to supply to the DUT 17, a contact test for confirming that the voltage is normally supplied from each voltage generator to the DUT power supply pin is realized. To do.

In order to solve the above-mentioned problems, in the structure of the present invention, the controller 33 is provided with opening / closing means 8 and 9 to n for disconnecting the output terminal of each voltage generator and performing contact check for each voltage generator. All of the opening / closing means are opened at the time of contact check, and then the opening / closing means are sequentially closed one by one, and the D / A converter 31 is opened.
~ 34 to supply the test voltage to the DUT, the voltage is measured by the A / D converters 27, 28 to n for sensing the voltage at the DUT end, and the DUT including the connection system of the supply cable and the sensing cable is measured according to the measured voltage value. There is a method of judging the quality of the electrical connection state with the power supply pin. Opening and closing means 8,
As 9 to n, there is a constituent means using a semiconductor switch or a reed relay for opening and closing the voltage supply output end and the sensing input end for sensing the voltage of the DUT pin.

Operation: A switch 8 which is an opening / closing means for disconnecting the output end,
Numerals 9 to n are opening / closing means for disconnecting the output end of each voltage generator, and can detect the sensing signal from the sensing cable system without being affected by other voltage generators. As a result, in addition to the conventional control, the controller 23 closes all the switches 8 to n at the time of non-contact check and switches 8 at the time of contact check.
After opening all of n through n, it is possible to perform contact check for each voltage generator independently with the DUT power supply pin by sequentially controlling opening and closing.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 (A) shows a plurality n of embodiments according to the present invention.
It is a block diagram which parallel-operates the voltage generator of a stand. The configuration is
In addition to the conventional components, switches 8 and 9 to n are added, and a controller 23 corresponding thereto is provided.

The switches 8 and 9 to n are opening / closing means for disconnecting the output terminals of the voltage generators individually, and are contacts of reed relays or semiconductor switches which can be individually controlled by the controller 23. This is an open / close switch for connecting to each other to enable independent contact check. As a result, the contact check of each voltage generator including the power supply cable system can be reliably performed.

In addition to the conventional control, the controller 23 closes all the switches 8 to n at the time of non-contact check, and switches 8 at the time of contact check.
After making all of n open, the open / close control is sequentially performed, and the contact check of each voltage generator is performed to perform the measurement.

That is, ON / OFF of the switch shown in FIG.
As in the OFF control sequence, first, only the switch 8 is turned ON, and the contact check is performed in the same manner as in the conventional case. Then, only the switch 9 is turned on, and the contact check is performed in the same manner as in the conventional case. By repeating this, only the last switch n is turned on, and the contact check is performed in the same manner as in the conventional case. Therefore, if all the contact check results are normal, it is clearly confirmed that the connection state of the supply cable system and the sensing cable system of all voltage generators connected in parallel and the contact check with the DUT power pin are normal. It will be possible.

FIG. 2 is a determination judgment chart for the voltage measurement values VM20 and VM21 of the voltage generators VS1 and VS2 showing an example of the results of the individual contact check, and Vd (-0.5V) and 0V. It is an example of voltage detection.
From this chart, the connection state of the supply cable system A point output terminal 11 and the sensing cable system B point output terminal 12 and the connection state of the supply cable system B point output terminal 13 and the sensing cable system D point output terminal 14 are individually determined. I know what I can do.

[0022]

Since the present invention is configured as described above, it has the following effects. By providing an opening / closing means for disconnecting the output terminals of the voltage generators operating in parallel, a single contact check can be performed. As a result, the sensing signal from the sensing cable system can be detected and measured without being affected by other voltage generators, and the voltage generator can be reliably detected. As a result, the contact check of each voltage generator including the power supply cable system can be reliably performed.

[Brief description of drawings]

FIG. 1A is a diagram illustrating a configuration example of a contact test device for a parallel connection voltage generator according to an embodiment of the present invention, and FIG. 1B is a diagram illustrating a switch ON / OFF control sequence.

FIG. 2 is a determination chart showing an example of an execution result of individual contact check according to the present invention.

FIG. 3 is an example of a circuit configuration in which two voltage generators are connected in parallel to a DUT to supply a voltage according to a conventional technique.

[Explanation of symbols]

 VS1, VS2, VSn Voltage generator 4, 25, 26 Contact check circuit 5, 6, 8, 9 Switch 11, 12, 13, 14 Output terminal 17 DUT VM20, VM21 Measured voltage value 23, 33 Controller 27, 28 A / D converter 31, 32 D / A converter R41, R42 Resistance

Claims (3)

[Claims] 1. A voltage generator having a contact check circuit, which is connected in parallel to a plurality of units and is supplied to a DUT, wherein each voltage generator is provided with an opening / closing means for disconnecting an output terminal, and this opening / closing means is provided at the time of contact check. A voltage generator to be connected in parallel in a semiconductor test device, which is provided with a controller for sequentially controlling opening and closing of the contacts to check contacts, and having the above. 2. In a contact check of a voltage generator which has a contact check circuit and is connected in parallel to supply to a DUT, each voltage generator is provided with an opening / closing means for disconnecting an output terminal, and each voltage generator is individually connected. A controller that performs contact check is installed in the controller. At the time of contact check, all of the opening / closing means are opened, and then the opening / closing means are closed one by one, and the D / A converter supplies the test voltage to the DUT. The voltage is measured by an A / D converter that senses, and the quality of the electrical connection with the DUT power pin including the connection system of the supply cable and the sensing cable is determined by the measured voltage value. Contact test method for parallel connection in semiconductor test equipment. 3. The switching device according to claim 1, wherein a voltage to be connected in parallel in a semiconductor test device using a semiconductor switch or a reed relay for opening and closing a voltage supply output end and a sensing input end for sensing the voltage of the DUT pin. Generator.