JP2011169914A - Withstand voltage test device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out a withstand voltage test that produces a result of determination even when the test is forcibly terminated from outside in the middle of test time set by a timer. <P>SOLUTION: A withstand voltage test device which, in carrying out a withstand voltage test by applying a test voltage to an object to be tested for the duration of test time, operates in a basic operation mode of, when a test current flowing through the object to be tested is larger than a predetermined current threshold, giving a rejection at that point of time and terminating the test, or when the test current is smaller than the current threshold, continuing the test until the test time elapses, giving an acceptance after the test time elapses, and terminating the test includes, as a specific control mode, a forcible stop mode of, upon receiving a termination signal to terminate the test from external instruction means before the test time elapses, giving an acceptance at that point of time and terminating the test without waiting for the test time to elapse. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a withstand voltage test apparatus, and more particularly, to a forced stop mode that is executed when a forced termination instruction is issued from the outside during a test.

  As a parameter for evaluating the safety and reliability of an electric / electronic device, firstly, electrical insulation can be mentioned. Insulation is an important element for preventing accidents. Therefore, the test method is defined by various safety standards such as IEC standard, UL standard, and Electrical Appliance and Material Control Law.

  The test voltage and test time are determined for each product. Basically, a predetermined test voltage (generally an AC voltage) is applied between the electrode terminals of the product (device under test) from the voltage generator. Then, the test current (leakage current) Ia flowing through the DUT is measured and compared with a preset current threshold value Ib. If Ia <Ib (or Ia ≦ Ib), a PASS (pass) determination is made. If Ia ≧ Ib (or Ia> Ib), it is determined as FAIL (failure).

  FIG. 5 shows a flowchart of a withstand voltage test that has been generally performed. First, after the “test voltage” to be applied to the device under test by the user, “current threshold value” and “test time” that are acceptance criteria are set in the control unit, the test is started. The test time is counted by a built-in timer of the control unit. During this test, a test current Ia flowing through the device under test is measured by the measurement unit, and a magnitude relationship between the test current Ia and the current threshold value Ib is determined by the control unit.

  As a result, if Ia <Ib, the test is continued until the test time elapses, and a PASS determination is issued after the test time elapses. On the other hand, if Ia ≧ Ib, the test is stopped at that point without waiting for the elapse of the test time and a FAIL judgment is issued.

  Thus, in the case of PASS determination with Ia <Ib, the test is continued until the test time elapses. In the withstand voltage test, although the test time varies depending on the test object, the test is not performed unless the test time elapses. This is because it is considered to be established.

  In other words, even if Ia <Ib, if the test is stopped before the time is up, the PASS determination is not issued. Note that the control unit of the conventional withstand voltage test apparatus is usually programmed to determine that the test time has elapsed based on the time-up signal from the built-in timer. On the other hand, in the case of FAIL determination with Ia ≧ Ib, the test object is immediately terminated because the device under test may be subject to dielectric breakdown.

  The conventional general withstand voltage test apparatus has the operation mode as described above. For example, when it is incorporated in a continuous assembly line of a product and is sequence-controlled under the control of the main control means of the line, The test time of the withstand voltage test may be set by the main control means of the line in relation to other equipment and tact time.

  In such a case, the test time setting timer provided in the main control means of the line has priority, and the test time set by the main control means is generally a timer of a withstand voltage test apparatus from the viewpoint of productivity. It will be shorter than the time that can be set with.

  Then, the withstand voltage test apparatus side regards the test end signal output from the main control means of the line as a forced end signal for terminating the test halfway, and the test ends as shown in the flowchart of FIG. 5, but Ia < Even if it is Ib, the PASS judgment is not issued.

  Therefore, since the PASS judgment is not issued on the main control means side of the line, there arises a problem that the device under test cannot be advanced to the next process. Apart from this, there is also a problem that even when the user forcibly terminates the test, the PASS judgment is not issued, so that the test must be performed again even if it is a pass product.

  Therefore, the subject of the present invention is that even in the withstand voltage test performed by applying a test voltage to the device under test for a predetermined test time, even when forced termination is applied from the outside during the test time set in the timer. The determination result is to be output.

In order to solve the above-described problems, the present invention provides a voltage generator for applying a predetermined test voltage to a device under test as described in claim 1, and flows to the device under test by applying the test voltage. A measurement unit that measures the test current, and a control unit that has at least a current threshold for determining whether the test current is acceptable and a test time, and a timer that counts the test time, and the control unit includes: When the test is started, the timer is started to apply the test voltage to the device under test from the voltage generator, and the test current measured by the measurement unit is monitored. If the test current is smaller than the threshold, the test is terminated at that time and the test is terminated. If the test current is smaller than the current threshold, the test is continued until the timer times the test time. And, in a withstand voltage test device for terminating test performed acceptance after a lapse of the test time,
In the specific control mode, when the control unit receives a forced end signal for ending the test from the external command means before the test time elapses, it makes a pass / fail judgment at that time and waits for the test time to elapse. It features a forced stop mode that ends the test.

  In the present invention, as described in claim 2, the external command means is preferably main control means for controlling the withstand voltage test apparatus in association with another test apparatus.

  Further, as described in claim 3, when the external command means is connected to the withstand voltage test device, the control unit preferably invalidates the timer.

  According to a fourth aspect of the present invention, the external command means may be a forced termination switch provided at the input section of the withstand voltage test device.

  According to the first aspect of the present invention, when the control unit receives a forced end signal for ending the test from the external command means before the test time elapses as the specific control mode, the control unit performs a pass / fail determination at that time. By providing a forced stop mode that terminates the test without waiting for the test time to elapse, a pass determination is issued even when a forced termination signal is issued during the test.

  Therefore, as described in claim 2, for example, even if it is incorporated in a continuous assembly line of a product and sequence-controlled under the control of the main control means of the line, the line can be operated without any trouble. . Further, even when the forced end switch according to claim 4 is pressed, a pass determination is issued.

  Further, as described in claim 3, when an external command means is connected to the withstand voltage test apparatus, the control unit invalidates its own timer, thereby omitting the step of determining whether the time is up or not. can do.

The schematic block diagram which shows an example of the withstand voltage test apparatus by this invention. The flowchart which shows the basic operation control mode of this invention. The flowchart which shows the 1st forced stop mode of this invention. The flowchart which shows the 2nd forced stop mode of this invention. The flowchart which shows operation | movement of the conventional withstand voltage test apparatus.

  Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic block diagram showing an example of a withstand voltage test apparatus according to the present invention, FIG. 2 is a flowchart showing a basic operation control mode of the present invention, and FIG. 3 is a first compulsory embodiment as a reference embodiment of the present invention. FIG. 4 is a flowchart showing a second forced stop mode corresponding to claim 1 of the present invention.

  As shown in FIG. 1, the withstand voltage test apparatus includes a voltage generator 11 that applies a predetermined test voltage to the device under test EUT, and a test current Ia that flows through the device under test EUT when the test voltage is applied. A connection to which a measuring unit 12, a control unit 13, an input unit 14 for giving test conditions to the control unit 13, a display unit 15 for displaying test results, and an external control means (external command means) not shown are connected. Terminal portion 16.

  The device under test EUT may be an electric / electronic device, an electronic component, an electronic material, or the like, and a test voltage is applied from the voltage generator 11 between a pair of electrode terminals (not shown). In the withstand voltage test apparatus, an AC power supply is generally used for the voltage generator 11, but a DC power supply may be used in some cases. The test voltage is determined for each EUT.

  The measurement unit 12 can be configured by a current detection resistor through which the test current Ia of the EUT to be tested flows and a voltmeter (both not shown) that measures a voltage drop generated in the current detection resistor. For the control unit 13, a CPU (Central Processing Unit), a microcomputer, or the like may be used.

  The control unit 13 is set with various test conditions such as a test voltage, a test time, and a pass / fail criterion current threshold value Ib, and the output of the voltage generator 11 is controlled based on the test voltage. The test time is measured by a timer built in the control unit 13.

  An operation panel such as a keyboard may be used for the input unit 14, and includes a forced termination switch. The display unit 15 is preferably a liquid crystal display panel or a plasma display, but a printer may be used.

  An external control means is connected to the connection terminal portion 16, and the withstand voltage test apparatus is incorporated in a continuous assembly line of a product, for example, and is sequence-controlled under the control of the main control means of the assembly line. In this case, the connection terminal portion 16 is connected to main control means (such as a personal computer) of the assembly line.

  In such a case, the test time of the withstand voltage test apparatus is set by the main control means which is an external control means. That is, the test time setting timer provided in the main control unit has priority, and from the viewpoint of assembly line productivity, the timer has a test time shorter than the time settable by the timer of the withstand voltage test device. Is set.

  Next, the operation of the present invention will be described. First, a basic operation control mode when a forced stop is not applied during the test will be described with reference to the flowchart of FIG.

  At the same time as the test is started, a predetermined test voltage is applied from the voltage generator 11 to the device under test EUT, and a built-in timer (not shown) of the control unit 13 is started. A test current Ia flowing through the EUT is measured (step ST1).

  Next, the control unit 13 determines the magnitude relationship between the test current Ia and the current threshold Ib (step ST2). As a result, if Ia <Ib (or Ia ≦ Ib), it is determined whether the test time has elapsed (step ST3).

  If the test time has not elapsed, the process returns to step ST1, and steps ST1 and ST2 are repeated until the test time elapses. Then, when the test time has elapsed (when the built-in timer expires), the PASS determination is displayed on the display unit 15 (step ST4), and the test is terminated.

  If Ia ≧ Ib (or Ia> Ib) in step ST2, the FAIL determination is displayed on the display unit 15 (step ST5), and at that time, the output of the voltage generator 11 is stopped and the test is stopped.

  In addition to the basic operation control mode, the present invention includes a first forced stop mode and / or a second forced stop mode as the specific control mode.

  In this specific control mode, an external control means (for example, the main control means of the assembly line) is connected to the connection terminal portion 16 and a test end signal is output from the external control means during the test, or input It operates when the forced termination switch on the part 14 is pressed.

  FIG. 3 is a flowchart of the first forced stop mode. In this mode, Ia <Ib (or Ia ≦ Ib), but it is determined in step ST3 that the test time has not yet passed, and step ST1. Step ST3a for determining whether to forcibly terminate when returning to step ST is added.

  That is, when a test end signal is output from the external control means or the forced end switch is pressed during the test, step ST4 is immediately executed to determine PASS, and then the test ends. In the case of FAIL determination, as in the basic operation control mode, step ST5 is executed at that time, and after the FAIL determination is made, the test is terminated.

  Next, the second forced stop mode will be described. In this mode, when a test end signal is issued from the external control means or when the forced end switch is pressed while waiting for the test time to elapse in step ST3, the interrupt process shown in FIG. 4 is executed, and Ia < If Ib (or Ia ≦ Ib), the PASS determination is made without waiting for the test time to elapse, and if Ia ≧ Ib (or Ia> Ib), the test is ended as FAIL determination.

  As described above, according to the present invention, even when the withstand voltage test is forcibly terminated in the middle of the withstand voltage test, the PASS determination and the FAIL determination are performed. For example, when applied to a product continuous assembly line or an automatic test system. Can be matched with the external control means and the test can proceed smoothly. Further, even when the operation is forcibly terminated manually, if Ia <Ib (or Ia ≦ Ib), a PASS determination is issued, so that it is possible to know that the product is non-defective even during the test.

  If the test time is set by the external control means connected to the external control means, the internal timer on the withstand voltage test device side is invalidated to determine whether the time is up or not. This can be omitted, and the burden on the control unit can be reduced.

  In addition, the withstand voltage test device of the present invention may be commercialized as a single-function device, or may be incorporated as one function of an electric measuring instrument having other measurement functions.

DESCRIPTION OF SYMBOLS 11 Voltage generation part 12 Measurement part 13 Control part 14 Input part 15 Display part 16 Connection terminal part of external control equipment

Claims (4)

A voltage generator for applying a predetermined test voltage to the device under test; a measurement unit for measuring a test current flowing through the device under test by applying the test voltage; and a current threshold value and test for determining whether or not the test current is acceptable And a control unit having a timer for measuring the test time,
The control unit starts the timer with the start of a test, applies the test voltage from the voltage generation unit to the device under test, monitors the test current measured by the measurement unit, and If the test current is larger than the current threshold, the test is terminated at that time and the test is terminated. If the test current is smaller than the current threshold, the timer counts the test time. In the withstand voltage test device that continues the test until the test time is over and the test is completed after the passage of the test time,
In the specific control mode, when the control unit receives a forced end signal for ending the test from the external command means before the test time elapses, it makes a pass / fail judgment at that time and waits for the test time to elapse. A withstand voltage test apparatus comprising a forced stop mode for terminating the test.   2. The withstand voltage test apparatus according to claim 1, wherein the external command means is main control means for controlling the withstand voltage test apparatus in association with another test apparatus.   The withstand voltage test apparatus according to claim 1 or 2, wherein when the external command means is connected to the withstand voltage test apparatus, the control unit invalidates the timer.   2. The withstand voltage test apparatus according to claim 1, wherein the external command means is a forced termination switch provided in an input section of the withstand voltage test apparatus.

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