JP2013015356A - Capacitor inspection device and inspection method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable contact check, charging check, and insulation resistance check to be positively conducted, even with an extremely simple structure.SOLUTION: After charging a capacitor C at a specified voltage at a charging step, in an inspection step, with a predetermined DC voltage applied to the capacitor C by a DC power source E via a pair of probes P, the current value (leak current) of the current running through the capacitor C is measured using an ammeter 11 to inspect whether the capacitor is good or bad. In this inspection, a voltmeter 12 is connected between the pair of probes P and a switch 13 is provided on the DC power source E, and then by turning the switch 13 off, contact check and charging check are conducted via the voltage measurement value measured by the voltmeter 12. If both checks produce good results, insulation resistance check is conducted by turning on the switch 13.

Description

  The present invention relates to a capacitor inspection apparatus and an inspection method thereof, and more particularly to a capacitor inspection technique that can perform a contact check or the like when measuring the insulation resistance of a capacitor.

  As shown in the equivalent circuit of FIG. 3, a general capacitor (capacitor) C includes a main capacitance Cx, an insulation resistance Rx, and a dielectric absorption factor D connected in parallel. .

  The insulation resistance Rx exists in a package in a chip element such as an electrolyte or a ceramic capacitor. The dielectric absorption factor D is due to dielectric polarization formed by an electric field generated when a voltage is applied to the capacitor C, and is represented by a series circuit of an internal resistance r and a dielectric polarization capacitance Co.

  With the capacitor C as the sample DUT to be measured, the measurement of the insulation resistance Rx is basically the same as the measurement of the insulation resistance. A DC voltage is applied between both terminals of the sample DUT to be measured, and the current flowing in the sample DUT at that time This is done by measuring (leakage current) with an ammeter.

  By the way, when a voltage is applied to the sample DUT to be measured, the dielectric polarization capacitor Co is initially charged through the internal resistance r, so that the insulation resistance Rx is measured after the dielectric polarization is stabilized. There is a need to do. The current that flows through the sample DUT after the dielectric polarization is stabilized is mainly a leakage current that flows through the insulation resistance Rx.

  Therefore, as shown in the image diagram of FIG. 4, a charging step and an inspection step are provided, and in the charging step, the sample DUT to be measured is preferably set to a voltage defined over multiple stages so that the dielectric polarization becomes stable. Charge (for example, refer to Patent Document 1).

  Then, in a subsequent inspection step, a predetermined DC voltage V is applied from the DC power source E to the sample DUT to be measured through the pair of probes P and P using the insulation resistance meter shown in FIG. The current I flowing through the sample DUT is measured by the DC ammeter A1. The insulation resistance Rx is obtained by V / I, and when the value is larger than a predetermined threshold value, it is determined as a non-defective product, and when the value is smaller than the threshold value, it is determined as a defective product.

  However, since the current I flowing through the measured sample (capacitor) DUT is very small, the probe contact failure, for example, when the probe P is disconnected from the terminal of the measured sample DUT, If there is an insulator, no voltage is applied to the sample DUT to be measured. As a result, the current flowing through the sample DUT to be measured is zero, and the insulation resistance value is determined to be larger than the threshold value. It can be done.

  Therefore, in order to perform a contact check as to whether or not the probe P is in electrical contact with the terminal of the sample DUT to be measured, an AC power source AC and an AC current are included in the insulation resistance meter as shown by a two-dot chain line in FIG. A contact check circuit 1 including a total A2 is provided (see, for example, Patent Document 2).

JP-A-10-115651 JP 2004-12330 A

  According to the contact check circuit 1 described above, an AC signal flows through a capacitor which is the DUT to be measured. Therefore, if a predetermined AC current is measured by the AC ammeter A2, contact (contact OK) and a predetermined AC current are detected. If is not measured, it can be determined as non-contact (contact NG).

  However, as a problem, the contact check circuit 1 described above requires an AC power supply AC, an AC voltmeter A2, a determination circuit as an auxiliary circuit thereof, a switch circuit for injecting an AC signal into the insulation resistance meter, and the like. Therefore, the configuration is complicated and expensive.

  In addition, it is not known whether or not the charging stage performed prior to the inspection stage is charged with the voltage defined for the sample DUT to be measured.

  Therefore, the problem of the present invention is that the structure can be contacted in the inspection stage with a simple structure and can be charged with the voltage specified for the sample to be measured (capacitor) in the previous charging stage. It is to be able to determine whether or not it has been done.

  In order to solve the above-described problems, the present invention provides a DC power source and a pair of probes that are connected to the DC power source and are capable of contacting both terminals of a capacitor to be inspected. An ampere meter connected between the DC power source and the one probe, and applying a predetermined DC voltage between both terminals of the capacitor from the DC power source through the probes, In a capacitor inspection apparatus that inspects the quality of the capacitor based on a current value measured by an ammeter, a voltmeter connected between the pair of probes and an output voltage of the DC power source applied to the capacitor And a switch for turning on and off.

  According to a preferred aspect of the present invention, as described in claim 2, the voltmeter is connected in parallel to a series circuit including the ammeter and the pair of probes, and the switch includes the voltage It is connected between one voltage detection terminal of the meter and the DC power supply.

  Further, the present invention includes a charging step and an inspection step as described in claim 3, wherein a predetermined DC voltage is applied to a capacitor to be inspected by a charging power source in the charging step. After charging, in the inspection step, the DC power supply is connected between the DC power supply and the one probe with a predetermined DC voltage applied between both terminals of the capacitor via a pair of probes. In a method for inspecting a capacitor in which the current value flowing through the capacitor is measured by an ammeter, and the quality of the capacitor is inspected, a switch for turning on and off the output voltage of the DC power source applied to the capacitor, and the pair of probes are provided. The voltmeter connected between the two terminals of the capacitor via the switch and the switch are controlled, and the ammeter and the voltmeter A control unit that performs a predetermined determination based on the value, and in the inspection step, the control unit turns off the switch, and when the measured value of the voltmeter at that time is 0 V, the probe Is determined to be non-contact with the terminal of the capacitor, and if the measured value of the voltmeter does not reach the voltage value applied in the charging step, it is determined that the charging is defective, and the measured value of the voltmeter is When the voltage value is substantially equal to the voltage applied in the charging step, the switch is turned on, and a predetermined DC voltage is applied between both terminals of the capacitor via the pair of probes from the DC power source. A capacitor inspection method is also included in which the quality of the capacitor is determined based on a current value measured by an ammeter.

  According to the present invention, a voltmeter is connected between a pair of probes that are in contact with both terminals of a capacitor to be inspected, and the DC power supply is provided with a switch for turning on and off its output voltage. When the switch is turned off and the measured value of the voltmeter at that time is 0 V, the probe can be determined to be non-contact with the capacitor terminal, and the measured value of the voltmeter reaches the voltage value applied in the charging step. If not, it can be determined that the charging is defective, and if the measured value of the voltmeter is approximately equal to the voltage value applied in the charging step, the switch is turned on and a capacitor is connected from the DC power source through a pair of probes. A predetermined DC voltage is applied between the two terminals, and the quality of the capacitor can be determined based on the current value measured by the ammeter at that time.

1 is a schematic circuit diagram showing a capacitor inspection device according to an embodiment of the present invention. In the contact check by a voltmeter, (a) A schematic diagram showing a circuit state where the probe is connected to the sample to be measured, (b) A schematic diagram showing a circuit state when the probe is not connected to the sample to be measured. The equivalent circuit diagram which shows the internal structure of a general capacitor | condenser. The image figure which shows the charge stage and test | inspection stage of a capacitor | condenser. The typical circuit diagram which shows the conventional insulation resistance meter (capacitor test | inspection apparatus) provided with the contact check circuit.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2, but the present invention is not limited to this. The present invention is preferably applied to a capacitor inspection system including the charging stage and the inspection stage described with reference to FIG.

  As shown in FIG. 1, the capacitor inspection apparatus according to this embodiment has a DC power source E that outputs a predetermined DC voltage and a DC power source as a basic configuration, similar to the conventional example described in FIG. A pair of probes P (P1, P2) that are connected to E and are capable of contacting both terminals of the DUT (capacitor C) to be measured; a DC power source E and one probe P; in this embodiment, a probe P1 on the high potential side; And an ammeter (DC ammeter) 11 connected between the two.

  Note that the pair of probes P are simply referred to as probes P when it is not necessary to distinguish between the high potential side and the low potential side. For the internal structure of the capacitor C that is the DUT to be measured, refer to the equivalent circuit diagram of FIG.

  In addition to the basic configuration described above, the capacitor inspection apparatus of the present invention includes a voltmeter (DC voltmeter) 12, a switch 13 for turning on and off an output (DC voltage) applied from the DC power source E to the sample DUT to be measured, The control unit 20 is provided.

  In this embodiment, the voltmeter 12 is connected in parallel to the series circuit including the ammeter 11 and the probes P1 and P2. However, as another aspect, the voltmeter 12 is connected between the probe P1 and the probe P2. Also good.

  Further, in this embodiment, the switch 13 is provided on the positive electrode side of the DC power supply E, but the arrangement location may be other than the voltage detection circuit of the voltmeter 12. As the switch 13, an optical semiconductor switch such as a relay, a semiconductor switch, or a photo moss relay can be used.

  The control unit 20 controls on / off of the switch 13, and based on the measured values of the ammeter 11 and the voltmeter 12, the probe P contact check, suitability for charging the measured sample DUT, and the insulation resistance of the measured sample DUT The quality of the product is judged. For the control unit 20, a CPU (Central Processing Unit), a microcomputer, or the like may be used.

  Next, the operation of this capacitor inspection apparatus will be described with reference to FIGS. 2 (a) and 2 (b). The sample DUT to be measured is charged to a specified voltage at the charging stage described in FIG. In this description, it is assumed that the charging voltage is 100V, for example. The probes P1 and P2 are assumed to be brought into contact with the terminal of the sample DUT to be measured by an automatic machine (not shown) (for example, an arm that can move in the XYZ directions).

  When the sample DUT to be measured charged in the charging stage is transferred to the inspection stage and set on a predetermined workpiece mounting table, the control unit 20 turns off the switch 13 as shown in FIG. The probes P1 and P2 are brought into contact with each terminal of the sample DUT to be measured, and the voltage measurement value V (voltage value of the sample DUT to be measured) by the voltmeter 12 is observed.

  If the voltage measurement value V is 0 V, the control unit 20 has one or both of the probes P1 and P2 electrically in contact with the terminal of the sample DUT to be measured, as shown in FIG. It is determined that there is no contact (contact check). If the contact is defective, probing is performed again, or the sample DUT to be measured is excluded from the product line.

  Further, when the voltage measurement value V is 70 V, for example, and has not reached 100 V, it is determined that the charging is defective (charging check). In the case of contact failure or charge failure, the sample DUT to be measured is excluded from the product line, or probing is performed again and charging is performed again.

  On the other hand, when the voltage measurement value is approximately 100 V, it is determined that the contacts of the probes P1 and P2 are good and the charging is good, the switch 13 is turned on, and the current measurement value I by the ammeter 11 is measured. (Leakage current of sample DUT to be measured) is observed (insulation resistance check).

  When the current measurement value I is smaller than a preset reference value, it is determined that the insulation resistance is good. When the current measurement value I is larger than the reference value, the sample to be measured is regarded as an insulation resistance defect. Exclude the DUT from the product line.

  As described above, according to the present invention, the three functions of contact check, charge check, and insulation resistance check are the same inspection by a simple circuit configuration in which a voltmeter and a switch are added to the conventional capacitor insulation resistance inspection circuit. Since a series of processes can be performed on the stage, the capacitor can be inspected with high reliability.

  In the above-described embodiment, the charging stage and the inspection stage are separated from each other. However, depending on the capacity of the sample DUT to be measured, the charge DUT and the inspection stage are not separated, and the sample DUT is measured in the inspection stage. It is also possible to charge the battery and then perform a contact check, a charge check and an insulation resistance check.

11 Ammeter 12 Voltmeter 13 Switch 20 Controller E DC power supply P (P1, P2) Probe DUT Sample to be measured (capacitor)

Claims (3)

Including a DC power supply, a pair of probes that are connected to the DC power supply and capable of contacting both terminals of the capacitor to be inspected, and an ammeter connected between the DC power supply and the one probe, Capacitor inspection device for applying a predetermined DC voltage between both terminals of the capacitor from the DC power source via the probes and inspecting the quality of the capacitor based on a current value measured by the ammeter at that time In
A capacitor inspection apparatus comprising: a voltmeter connected between the pair of probes; and a switch for turning on and off an output voltage of the DC power supply applied to the capacitor.   The voltmeter is connected in parallel to a series circuit including the ammeter and the pair of probes, and the switch is connected between one voltage detection terminal of the voltmeter and the DC power supply. The capacitor inspection apparatus according to claim 1. A charging step and an inspection step. In the charging step, a predetermined DC voltage is applied to the capacitor to be inspected by a charging power source and charged in the charging step. With a predetermined DC voltage applied between both terminals of the capacitor, the current value flowing through the capacitor is measured with an ammeter connected between the DC power source and the one probe. In the capacitor inspection method for inspecting pass / fail,
A switch for turning on and off the output voltage of the DC power supply applied to the capacitor, a voltmeter connected between both terminals of the capacitor via the pair of probes, and controlling the switch, the ammeter and the A control unit that performs a predetermined determination based on the measured value of the voltmeter,
In the inspection step, the control unit turns off the switch, and when the measured value of the voltmeter at that time is 0 V, the probe determines that the probe is not in contact with the terminal of the capacitor, and the voltmeter If the measured value does not reach the voltage value applied in the charging step, it is determined that the charging is defective,
When the measured value of the voltmeter is substantially equal to the voltage value applied in the charging step, the switch is turned on and a predetermined direct current is connected between both terminals of the capacitor from the direct current power source through the pair of probes. A method for inspecting a capacitor, wherein a voltage is applied and the quality of the capacitor is determined based on a current value measured by the ammeter at that time.

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