JPH05232176A - Continuity testing device - Google Patents

Abstract

PURPOSE:To determine a continuity failure of a contact or an ohmic contact failure of a test terminal easily by comparing a voltage for judgement which is output from a voltage generation circuit for judgement with a reference voltage for judging the contact of the test terminal. CONSTITUTION:A reference voltage generation circuit 7 generates a reference voltage for judging the continuity of a contact and a reference voltage generation circuit 8 generates a reference voltage for judging the contact of a test terminal. Then, a voltage V1 for judgment which is generated by a voltage generation circuit 1 for judgment is compared with a reference voltage for judging the continuity of the contact which is generated by the circuit 7 and then a comparator C1 judges the continuity of a contact 9 to be tested. Also, at the time of judgment of continuity failure of the contact, a comparator 2 compares the voltage V1 with a reference voltage for judging contact of the test terminal which is generated by the circuit 8 for determining whether the cause for judging continuity failure is a failure judgment caused by contact failure of the test terminal or not, thus judging ohmic contact between the contact and the test terminal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuity test apparatus, and more particularly to a continuity test apparatus capable of eliminating an error in a pass / fail judgment due to a poor contact of a test terminal with an object to be tested.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a continuity test apparatus of this type has test terminals T5, T connected to contact terminals 13, 14 when conducting a continuity test of a contact 10 of a device under test 11.
At both ends of 6, the continuity signal determiner C3 and the ground GND are provided. If the contact 10 does not have continuity, it becomes defective, the contact continuity signal 14 is not output to the output of the continuity signal determiner C3, and if it is a non-defective product, the contact continuity signal is output. However, in this determination, when a defect is determined, it is determined as a conduction defect without distinguishing whether the contact 10 is a conduction defect or a test terminal contact defect.

[0003]

The above-described conventional continuity testing apparatus has a drawback in that, in addition to the poor continuity of the contact, which is the original failure when determining the poor continuity, the poor contact of the test terminal in the test state is included. was there.

[0004]

A continuity test apparatus according to the present invention comprises a test terminal connected to both ends of a contact terminal of a device under test having a contact, and a judgment voltage for judging a test result by the test terminal. Voltage generation circuit, a first reference voltage generation circuit for generating a contact continuity determination reference voltage serving as a determination reference of the continuity test result, a determination voltage output from the determination voltage generation circuit, and the contact conduction determination A contact continuity determination comparator for determining whether the contact is conductive or not, and a test terminal contact determination reference voltage for determining contact failure of the test terminal when the contact is defective.
Of the reference voltage generation circuit, the judgment voltage output from the judgment voltage generation circuit and the test terminal contact judgment reference voltage are compared to determine whether the cause of continuity failure is a failure due to contact failure of the test terminal. And a comparator for determining the contact of the test terminal.

[0005]

The present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of an embodiment of the present invention. FIG. 1 is composed of a judgment voltage generation circuit 1 and a pass / fail judgment circuit 2. The determination voltage generation circuit 1 includes test terminals T1 to T4 connected to both ends of the contact terminals 3 and 4 of the device under test 10 and a determination voltage generation resistor r1 connected to the test terminals to generate a determination voltage V1. ~ R4. Pass / fail judgment circuit 2
Is a reference voltage generation circuit 7 for generating a reference voltage for contact continuity determination, a reference voltage generation circuit 8 for generating a test terminal contact determination reference voltage, a determination voltage V1, and a contact generated by the reference voltage generation circuit 7. A comparator C1 that determines the continuity of the contact 9 under test by comparing it with a reference voltage for continuity determination, and whether or not the cause of the continuity defect determination is the defect determination due to the contact defect of the test terminal when determining the continuity defect of the contact. In order to make a judgment, the judgment voltage V1 is compared with a test terminal contact judgment reference voltage generated by the reference voltage generation circuit 8 to form a comparator C2 for judging the contact between the contact and the test terminal.

Next, the operation and determination method of this embodiment will be described with reference to FIGS. 1 and 2. First, regarding the determination condition, the comparator C1 determines that the contact conduction is good when the determination voltage V1 is smaller than the contact conduction determination reference voltage. Further, the comparator C2 determines that the test terminal has a contact failure when the determination voltage V1 is higher than the test terminal contact determination reference voltage. The conditions for determining the continuity of the contact under test are
Check that all the test terminals are in contact with the contact terminals of the DUT,
Alternatively, either the test terminal T1 or the test terminal T2 is in contact with the contact terminal of the DUT, and the test terminal T3 or the test terminal T4 is in contact with the contact terminal of the DUT, In both cases, the current supplied from the power supply Vcc flows through the resistance r1, the test contact, and the resistance r2 and the resistance r4 depending on the contact state of the test terminal.

Next, the conditions for determining the conduction failure of the contact under test are as follows:
All of the test terminals T1 to T4 come into contact with the contact terminals of the device under test, and the current supplied from the power supply Vcc flows from the resistor r1.
This is the case when it flows through the resistance r3. Further, the contact failure determination condition of the test terminal is that both the test terminals T1 and T2 are not in contact with the contact terminals of the DUT, or the test terminals T3 and T2.
If both 4 are not in contact with the contact terminal of the DUT,
Alternatively, either of the three test terminals T1 to T4 is not in contact with the contact terminal of the DUT,
The current supplied from the power source Vcc does not flow through the contact under test, and the resistance r3 depends on the contact state of the test terminal.
2, when the resistance r4 flows. That is, the determination voltage V1 input to the comparator C1 and the comparator C2 is determined by the ratio of the resistance r1 and the resistance r2 to the resistance r4 depending on the path of the flowing current.

FIG. 2 shows a calculation formula of the judgment voltage for each contact failure test terminal and the judgment voltage when the values are substituted into the resistors r1 to r4. The contact conduction good determination condition is that the resistance r3 is not included in the determination voltage calculation formula, and the contact conduction defect determination condition is that only the resistance r3 is included in the determination voltage calculation formula. The contact failure of the test terminal is caused by the resistance r3 and the resistance r2 or the resistance r
4 or the resistors r2, r3 and r4 are included.

Therefore, if the judgment voltage is good continuity <defective contact continuity <defective test terminal contact, then (r2 + r4) <r3
You can set it to.

Based on the calculation formula of FIG. 2 in the item of judgment voltage of FIG. 2, power supply Vcc = 5 v, resistance r1 = 10 Ω, resistance r
The calculation value of the judgment voltage obtained by substituting 2 = 2Ω, resistance r3 = 10Ω, and resistance r4 = 4Ω is shown. Considering the contact resistance between the test terminals T1 and T2 and the contact terminal 3 and the contact resistance between the test terminals T3 and T4 and the contact terminal 4 in the calculated voltage for judgment, the voltage for making the determination is as follows. It is performed under the conditions (1), (2) and (3).

Contact Continuity Good Condition Judgment Voltage <2.5v (1) Contact Continuity Poor Condition 2.5v ≦ Judgment Voltage <2.73v (2) Test Terminal Contact Poor Condition 2.73v ≦ Judgment Voltage (3) Furthermore, when the detailed content of the contact failure of the test terminal is required, it can be determined by the following conditions (4), (5) and (6).

Contact failure condition for terminals 1 and 2 2.73v ≤ judgment voltage <2.92v (4) Contact failure condition for terminals 3 and 4 2.92v ≤ judgment voltage <3.08v (5) Both-sided test terminal Contact failure condition 3.08 v ≤ judgment voltage (6) Therefore, the contact continuity judgment reference voltage of the contact continuity judgment reference voltage generation circuit 7 is set to 2.5 v, and the test terminal contact judgment reference voltage generation circuit 8 If the test terminal contact judgment reference voltage is set to 2.73v, the comparator C1 compares the judgment voltage with the contact continuity judgment reference voltage and outputs the contact conduction signal 5 when the continuity test judges that the contact continuity is good. Output. Comparator C
2 compares the judgment voltage V1 with the test terminal contact judgment reference voltage, and outputs the test terminal conduction signal 6.

When the continuity judgment is the contact continuity failure judgment, the comparator C1 compares the judgment voltage V1 with the reference voltage for contact continuity judgment and does not output the contact continuity signal 5. The comparator C2 is
The judgment voltage V1 is compared with the test terminal contact judgment reference voltage, and the test terminal conduction signal 6 is output.

When the continuity is judged to be the contact failure of the test terminal, the contact continuity judgment comparator C1 compares the judgment voltage V1 with the reference standard for contact continuity judgment, and does not output the contact continuity signal 5. The test terminal contact determination comparator C2 compares the determination voltage V1 with the test terminal contact determination reference voltage, and does not output the test terminal conduction signal 6.

As described above, the contact conduction signal 5 can be used to determine the contact conduction, and if the contact conduction determination is defective, the test terminal conduction signal 6 can be used to determine the contact failure of the test terminal.

[0016]

As described above, according to the present invention, the judgment voltage generating circuit and the pass / fail judgment circuit are provided, so that it is possible to easily judge whether the contact is defective or the test terminal is defective. .. Further, by adding the reference voltage generating circuit and the test terminal contact judgment comparator, it is possible to easily judge the defective terminal.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of the present embodiment.

FIG. 3 is a circuit diagram of a conventional continuity test device.

[Explanation of symbols]

 1 Judgment voltage generation circuit 2 Pass / fail judgment circuit 3,4 Contact terminal 5 Contact conduction signal 6 Test terminal conduction signal 7,8 Reference voltage generation circuit 9 Contact under test 10 Test object 11 Test object C1, C2 Comparator T1 T6 test terminal r1 to r4 resistance Vcc power supply V1 determination voltage

Claims (2)

[Claims] 1. A test terminal connected to both ends of a contact terminal of a device under test having a contact, and a judgment voltage generation circuit for generating a judgment voltage for judging a test result by the test terminal.
A first reference voltage generation circuit that generates a contact continuity judgment reference voltage that serves as a judgment reference of the continuity test result, and a judgment voltage output from the judgment voltage generation circuit and the contact continuity judgment reference voltage are compared. And a second reference voltage generation circuit for generating a reference voltage for test terminal contact determination for determining contact failure of a test terminal when determining contact failure of the contact, Test terminal contact determination for determining whether the determination voltage output from the determination voltage generation circuit is compared with the test terminal contact determination reference voltage to determine whether the conduction failure determination cause is due to the contact failure of the test terminal Continuity test device, comprising: 2. A resistor r2 connected in parallel between two test terminals connected to one terminal of both terminals of the DUT having the contact, and the other terminal of both terminals of the DUT. Resistance r connected in parallel between two test terminals connected to
4 and a resistor r connecting the resistor r2 and the resistor r4.
3. The continuity test apparatus according to claim 1, wherein the resistance tester has a resistance value of (r2 + r4) <r3.