JP7009814B2 - Insulation inspection equipment and insulation inspection method - Google Patents

Description

The present invention relates to an insulation inspection device and an insulation inspection method for inspecting the insulation of a substrate on which a plurality of conductor patterns are formed.

Conventionally, a DC voltage is supplied from the power supply unit between a pair of conductor patterns, an insulation resistance value is calculated from the voltage value and the current value obtained between the conductor patterns, and when the calculation of the resistance value is completed, the power supply unit is used. There is known a technique for reducing the applied voltage value by controlling the voltage (see, for example, Patent Document 1). Patent Document 1 describes between a pair of conductor patterns when a detection signal is output from the discharge detection unit from immediately after the start of DC voltage output by the power supply unit to the completion of determination of the insulation state based on the resistance value. It is described that it detects that a spark has occurred.

JP-A-2015-10880 (paragraphs 0043, 0044)

By the way, when sparks occur between the conductor patterns, the substrate between the conductor patterns may be carbonized or soiled, and the resistance value between the conductor patterns may decrease. In addition, the conductor pattern may be chipped due to sparks. Further, when a chip is generated in the conductor pattern, sparks may be more likely to occur at the edge of the missing portion, or sparks may be more likely to occur due to a decrease in the resistance value between the conductor patterns.

As described above, if the discharge of sparks or the like continues for a long time or the discharge of sparks or the like is repeated, there is a disadvantage that the damage to the substrate is expanded.

An object of the present invention is to provide an insulation inspection device and an insulation inspection method capable of reducing the possibility that damage to a substrate due to electric discharge will spread.

The insulation inspection device according to the present invention comprises a plurality of probes for contacting the plurality of conductor patterns on a substrate to be inspected on which a plurality of conductor patterns are formed, and the plurality of conductors via the plurality of probes. A power supply unit that outputs a voltage between the first pattern, which is one of the patterns, and the second pattern, which is any other than the first pattern, and the first pattern and the second pattern. A discharge detection unit that detects the occurrence of at least one of sparks and partial discharges between them, and a power supply control that stops or reduces the voltage output by the power supply unit when the discharge detection unit detects the occurrence of at least one of them. It has a part.

Further, the insulation inspection method according to the present invention is a first pattern which is one of the plurality of conductor patterns and any other than the first pattern on the substrate to be inspected in which a plurality of conductor patterns are formed. A power supply output step that outputs a voltage between the first pattern and the second pattern, and a discharge detection step that detects the occurrence of at least one of a spark and a partial discharge between the first pattern and the second pattern. When at least one of the occurrences is detected, the power supply control step of stopping or lowering the voltage output by the power supply output step is included.

According to these configurations, the occurrence of at least one of sparks and partial discharges between the first pattern and the second pattern is detected, and between the first pattern and the second pattern to be inspected for insulation. When at least one of them occurs, the occurrence of at least one of them is detected, and the voltage output output between the first pattern and the second pattern for the insulation inspection is stopped or reduced. As a result, the possibility that the discharge of sparks or the like continues for a long time or the discharge is repeated can be reduced, and the possibility that the damage to the substrate due to the discharge spreads can be reduced.

Further, it is preferable to further include a forced discharge unit that conducts the first pattern and the second pattern when at least one of the occurrences is detected by the discharge detection unit.

According to this configuration, when the occurrence of at least one of the above is detected, the first pattern and the second pattern are conducted, the stray capacitances of the first pattern and the second pattern are discharged, and the first pattern and the second pattern are discharged. Since the potential is made the same as that of the pattern, the possibility that the discharge such as sparks continues for a long time or the discharge is repeated can be reduced, and the possibility that the damage to the substrate due to the discharge spreads can be reduced.

Further, a switch that opens and closes a conductive path from the power supply section to at least one of the first pattern and the second pattern at a position different from the conduction path conducted by the forced discharge section in order to output the voltage. It is preferable that the power supply control unit stops the voltage output by the power supply unit by opening the switch when at least one of the occurrences is detected by the discharge detection unit.

According to this configuration, when at least one of the spark and the partial discharge occurs, the switch is opened and the power supply unit is separated from at least one of the first pattern and the second pattern, so that the first and second patterns can be separated. The voltage output of the power supply unit is stopped immediately. As a result, it is possible to prevent the spark or partial discharge from continuing for a long time or the spark or partial discharge from being repeated, so that the possibility that the damage to the substrate due to the discharge such as the spark or partial discharge spreads is reduced. Further, the switch opens and closes the conductive path from the power supply section to the first or second pattern to be inspected at a position different from the conduction path that is the path of discharge by the forced discharge section, so that even if the switch is opened, the switch can be used. The discharge of the charge charged in the first and second patterns is not hindered.

The discharge detection unit is preferably configured using an FPGA, an ASIC, or a microcomputer that uses or does not use a real-time OS.

According to this configuration, it is possible to judge whether or not a spark has occurred at a higher speed than when judging by a computer using an information system OS such as a personal computer, so that the damage to the board due to the spark may increase. Is easy to reduce.

Further, it is preferable to further include a determination unit for determining the insulation between the patterns based on the voltage and current between the first pattern and the second pattern.

According to this configuration, the insulation between the first pattern and the second pattern can be determined.

The insulation inspection device and the insulation inspection method having such a configuration can reduce the possibility that the damage to the substrate due to the discharge spreads.

It is a schematic block diagram of the insulation inspection apparatus which uses the insulation inspection method which concerns on one Embodiment of this invention. It is a block diagram which shows an example of the structure of the discharge detection part shown in FIG. It is a flowchart which shows an example of the operation of the insulation inspection apparatus shown in FIG. It is explanatory drawing for demonstrating the circuit operation of a power-source control process.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. It should be noted that the configurations with the same reference numerals in the respective figures indicate that they are the same configurations, and the description thereof will be omitted. FIG. 1 is a schematic configuration diagram of an insulation inspection device 1 using the insulation inspection method according to the embodiment of the present invention. FIG. 1 shows a state in which the substrate P to be inspected is connected to the insulation inspection device 1 for the insulation inspection.

The substrate P to be inspected is, for example, a printed wiring board, a glass epoxy board, a flexible board, a ceramic multilayer wiring board, an electrode plate for a display such as a liquid crystal display or an EL (Electro-Luminescence) display, a touch panel, or the like. Various substrates such as a transparent conductive plate, a package substrate or film carrier for a semiconductor package, a semiconductor wafer, a semiconductor chip, or a semiconductor substrate such as a CSP (Chip Size Package) may be used.

FIG. 1 shows an example in which four conductor patterns P1, P2, P3, and P4 (conductor patterns) are formed on the surface of the substrate P.

The insulation inspection device 1 shown in FIG. 1 includes probes Pr1, Pr2, Pr3, Pr4, a power supply unit 2, a current detection unit 3, a voltage detection unit 4, a switching circuit unit 5, a discharge detection unit 6 (power supply control unit), and a switching element. It includes SW1 (forced discharge unit), switching element SW2 (switch), and control unit 7.

The probes Pr1, Pr2, Pr3, Pr4 are contacts that are in contact with the conductor patterns P1, P2, P3, P4 of the substrate P, respectively. The number of conductor patterns and probes may be plural, and is not limited to four. The switching elements SW1 and SW2 are configured by using, for example, a semiconductor switching element such as a transistor, a relay switch, or the like.

The power supply unit 2 is a power supply circuit that outputs a voltage for insulation inspection between conductor patterns to be inspected. The power supply unit 2 is a DC constant voltage power supply circuit configured by using, for example, a switching power supply circuit or the like. The positive side output terminal of the power supply unit 2 is connected to the switching circuit unit 5 via the switching element SW2, the discharge detection unit 6, and the positive side wiring Lp. The negative side output terminal of the power supply unit 2 is connected to the switching circuit unit 5 via the current detection unit 3 and the negative side wiring Lm. Further, the negative side output terminal of the power supply unit 2 is connected to the circuit ground, and the negative side wiring Lm is connected to the circuit ground via the current detection unit 3.

The power supply unit 2 is not necessarily limited to the constant voltage power supply circuit. The power supply unit may be a variable voltage source, for example, as described in Japanese Patent Application Laid-Open No. 2015-45542, so that the output voltage of the constant current source and the constant current source does not exceed a predetermined upper limit voltage. It may be used as a power supply unit in combination with a limiter circuit that limits the voltage. As the power supply unit 2, for example, the step-up switching power supply circuit described in Japanese Patent Application Laid-Open No. 2001-178137 can be used.

The current detection unit 3 is configured by using, for example, a shunt resistor, a Hall element, an analog-digital converter, or the like. The current detection unit 3 detects the current I flowing through the minus side wiring Lm, and outputs a signal indicating the detected current I to the control unit 7.

The voltage detection unit 4 is configured by using, for example, a voltage dividing resistor, an analog-digital converter, or the like. The voltage detection unit 4 detects the voltage V between the positive side wiring Lp and the circuit ground, and outputs a signal indicating the detected voltage V to the control unit 7. Since the circuit ground is connected to the negative side wiring Lm via the current detection unit 3, the voltage detection unit 4 has the voltage V between the positive side wiring Lp and the negative side wiring Lm, that is, the conductor pattern to be inspected. The voltage V between them will be detected.

The switching circuit unit 5 is configured by using, for example, a plurality of switching elements that are turned on and off according to a control signal from the control unit 7. The switching circuit unit 5 has a connection relationship between the positive side wiring Lp and the probes Pr1, Pr2, Pr3, Pr4, and the negative side wiring Lm and the probes Pr1, Pr2, Pr3, Pr4, depending on the combination of on and off of each switching element. It is possible to switch the connection relationship of.

Thereby, for example, when performing an insulation inspection between the conductor patterns P1 and P2, the control unit 7 connects the probe Pr1 and the positive side wiring Lp by the switching circuit unit 5, and connects the probe Pr2 and the negative side wiring Lm. Connect. As a result, the output voltage from the power supply unit 2 is applied between the conductor patterns P1 and P2, the current flowing between the conductor patterns P1 and P2 is detected by the current detection unit 3, and the voltage between the conductor patterns P1 and P2 is voltage detected. It is detected in part 4. In this case, the conductor pattern P1 corresponds to an example of the first pattern, and the conductor pattern P2 corresponds to an example of the second pattern.

The control unit 7 may perform an insulation inspection between one of the plurality of conductor patterns and the remaining wiring patterns. In this case, the control unit 7 may connect the probe Pr1 and the positive side wiring Lp by the switching circuit unit 5, and connect the probes Pr2, Pr3, Pr4 and the negative side wiring Lm. In this case, the conductor pattern P1 corresponds to an example of the first pattern, and the conductor patterns P2, P3, P4 correspond to an example of the second pattern.

Hereinafter, in order to simplify the explanation, an insulation inspection between the conductor patterns P1 and P2 is illustrated, the probe Pr1 and the positive side wiring Lp are connected by the switching circuit unit 5, and the probe Pr2 and the negative side wiring Lm are connected. A case where the wiring is performed will be described (FIG. 1).

For example, one end of the switching element SW1 is connected to the power supply unit 2 via the switching element SW2 and is connected to the positive side wiring Lp via the discharge detection unit 6. The other end of the switching element SW1 is connected to the circuit ground. The switching element SW1 is turned on and off according to a control signal from the control unit 7. The switching element SW1 is normally turned off.

When the switching element SW1 is turned on, the conductor pattern to be inspected, for example, the conductor pattern P1 and the conductor pattern P2, conduct with each other via the circuit ground, the current detection unit 3, the switching circuit unit 5, and the probes Pr1 and Pr2. As a result, the conductor patterns P1 and P2 are immediately set to substantially the same potential.

The switching element SW1 corresponds to an example of a forced discharge unit. The forced discharge unit is not limited to the example in which the switching element SW1 is composed of a single unit. For example, the forced discharge unit may be configured by a series circuit of a switching element and a resistor.

The discharge detection unit 6 detects the occurrence of sparks and partial discharges between the conductor patterns to be inspected, for example, between the conductor patterns P1 and P2. When the discharge detection unit 6 detects the occurrence of spark or partial discharge, it outputs a discharge detection signal to the switching element SW1 and turns on the switching element SW1. Partial discharge is an electrical discharge that partially bridges the insulation, as described, for example, in the definition of terms in JIS C 60664-1 (IEC60664-1).

Further, when the discharge detection unit 6 detects the occurrence of spark or partial discharge, the discharge detection signal is output to the power supply unit 2 to stop the switching operation of the power supply unit 2 and stop the voltage output of the power supply unit 2. .. Further, when the discharge detection unit 6 detects the occurrence of spark or partial discharge, the discharge detection signal is output to the switching element SW2 to disconnect the power supply unit 2 from the conductor pattern P1 and stop the voltage output of the power supply unit 2. Let me. The discharge detection unit 6 shown in FIG. 1 also serves as a power supply control unit that stops the voltage output by the power supply unit 2 when the occurrence of spark or partial discharge is detected.

Further, when the discharge detection unit 6 detects the occurrence of spark or partial discharge, it outputs a discharge detection signal to the control unit 7 and notifies the control unit 7 of the occurrence of spark or partial discharge.

FIG. 2 is a block diagram showing an example of the configuration of the discharge detection unit 6 shown in FIG. The discharge detection unit 6 shown in FIG. 2 includes a current detection circuit 61, a voltage detection circuit 62, a high-speed AD converter 63, and an FPGA (Field Programmable Gate Array) 64.

The current detection circuit 61 detects the current flowing in the positive side wiring Lp, that is, the current I flowing between the conductor patterns P1 and P2, and outputs a voltage signal corresponding to the current value to the high-speed AD converter 63. As the current detection circuit 61, for example, a shunt resistor or a Hall element can be used.

The voltage detection circuit 62 detects the voltage between the circuit ground and the positive side wiring Lp, that is, the voltage V between the conductor patterns P1 and P2, and outputs a voltage signal corresponding to the voltage value to the high-speed AD converter 63. As the voltage detection circuit 62, for example, a voltage dividing resistor can be used, or wiring that directly connects the positive side wiring Lp to the high-speed AD converter 63 may be used.

The high-speed AD converter 63 is a so-called analog-digital converter, which converts the voltage signal output from the current detection circuit 61 and the voltage detection circuit 62 into a digital value and outputs the voltage signal to the FPGA 64. The high-speed AD converter 63 preferably has a high conversion speed.

A preset logic operation circuit is programmed in the FPGA 64. The FPGA 64 determines the occurrence of sparks and partial discharges based on the voltage signal output from the current detection circuit 61 or the voltage detection circuit 62. The FPGA 64 can determine, for example, that a spark has occurred when the current I detected by the current detection circuit 61 increases instantaneously. Alternatively, the FPGA 64 can determine, for example, that a spark has occurred when the voltage V detected by the voltage detection circuit 62 drops instantaneously.

Alternatively, the FPGA 64 takes, for example, the time required for the current I measured by the current detection circuit 61 to fall below a preset threshold value after the current supply to the conductor pattern to be inspected by the power supply unit 2 is started. , It may be determined that a spark or a partial discharge has occurred when the preset predetermined time is exceeded.

By determining the occurrence of sparks and partial discharges with FPGA64, compared to the case of determining the occurrence of sparks and partial discharges with a personal computer using an information system OS (Operating System) such as the control unit 7 described later, for example. And it becomes possible to judge the occurrence of partial discharge in a short time. The discharge detection unit 6 determines the occurrence of sparks and partial discharges by using an ASIC (application specific integrated circuit) or a microcomputer that uses a real-time OS (Operating System) or does not use an OS instead of FPGA64. May be good.

Further, the discharge detection unit 6 does not include the current detection circuit 61 and the voltage detection circuit 62, but instead sparks and partially discharges based on the current I and voltage V detected by the current detection unit 3 and the voltage detection unit 4. May be determined.

The discharge detection unit may detect the occurrence of sparks and partial discharges, and is not limited to the example of determining the occurrence of sparks and partial discharges using FPGA, and various detection methods can be used. As a method for detecting the occurrence of sparks, the discharge detection unit may use, for example, Japanese Patent No. 3546046, Japanese Patent No. 3953087, Japanese Patent No. 4369949, Japanese Patent No. 4918339, Japanese Patent No. 5866943, Japanese Patent Application Laid-Open No. 2015- Spark may be detected by using the spark detection method described in Japanese Patent Application Laid-Open No. 10880, Japanese Patent Application Laid-Open No. 2015-45542, and the like.

The discharge detection unit may detect the occurrence of a partial discharge based on the temporal change of the current I measured by the current detection circuit 61, for example, as described in Japanese Patent Application Laid-Open No. 2015-45542. Further, for example, as described in Japanese Patent Application Laid-Open No. 2010-32457, the discharge detection unit determines that a partial discharge has occurred when it detects an electromagnetic wave generated when the partial discharge occurs, thereby causing the partial discharge. May be detected. Alternatively, the discharge detection unit may detect a partial discharge based on the method described in a standard such as JIS C 60664-1 (IEC60664-1).

Further, the discharge detection unit is not limited to the example of detecting the occurrence of spark and partial discharge, and may be configured to detect only one of spark and partial discharge.

The control unit 7 includes, for example, a CPU (Central Processing Unit) that executes a predetermined logical operation, a RAM (Random Access Memory) that temporarily stores data, a non-volatile storage unit that stores a predetermined control program, and a non-volatile storage unit thereof. It is configured with peripheral circuits and the like. The control unit 7 is configured by using, for example, a personal computer using an information system OS (Operating System). The control unit 7 functions as an inspection control unit 71 and a determination unit 72 by executing a control program.

The inspection control unit 71 sequentially selects the first pattern and the second pattern to be inspected from the plurality of conductor patterns formed on the substrate P, and the switching circuit unit 5 first sets the positive side wiring Lp. It is made conductive with the pattern, the negative side wiring Lm is made conductive with the second pattern, and the voltage V is output between the first pattern and the second pattern by the power supply unit 2.

The determination unit 72 determines the insulation between the first pattern and the second pattern based on the current I detected by the current detection unit 3 and the voltage V detected by the voltage detection unit 4. Specifically, the determination unit 72 calculates the insulation resistance R between the first pattern and the second pattern from the current I and the voltage V based on the following equation (1).
Insulation resistance R = V / I ... (1)

Then, the determination unit 72 compares the preset reference resistance Rref with the insulation resistance R, determines that the insulation state is good if the insulation resistance R is equal to or higher than the reference resistance Rref, and sets the insulation resistance R to the reference resistance Rref. If it does not meet the requirements, it is judged that the insulation is poor.

The insulation inspection device 1 may not include the voltage detection unit 4, and the determination unit 72 may determine the insulation state based on the voltage V preset as the output voltage of the power supply unit 2.

Next, the operation of the insulation inspection device 1 configured as described above will be described. FIG. 3 is a flowchart showing an example of the operation of the insulation inspection device 1 shown in FIG. First, in the initial state, the switching element SW1 is turned off, the switching element SW2 is turned on, and the power supply unit 2 performs a switching operation to output the voltage V (step S1).

Next, the inspection control unit 71 selects the first and second patterns to be inspected from the conductor patterns P1, P2, P3, and P4 (step S2). Next, the inspection control unit 71 connects the first pattern and the positive side wiring Lp by the switching circuit unit 5, and connects the second pattern and the negative side wiring Lm. As a result, the voltage V from the power supply unit 2 is output between the first pattern and the second pattern (step S3: power supply output step).

When a voltage V is applied between the first pattern and the second pattern, the stray capacitances of the first pattern and the second pattern are charged, and the voltage between the first pattern and the second pattern rises. Therefore, the inspection control unit 71 receives a discharge detection signal from the discharge detection unit 6 until, for example, a preset standby time elapses after the voltage is applied, or until the detection voltage of the voltage detection unit 4 stabilizes. Is not detected (step S4).

If neither spark nor partial discharge is detected by the discharge detection unit 6 (NO in step S4), the determination unit 72 determines the current I detected by the current detection unit 3 and the voltage detected by the voltage detection unit 4. Based on V, the insulation resistance R is calculated by the above equation (1) (step S5).

Next, the determination unit 72 compares the reference resistance Rref with the insulation resistance R (step S6: determination step), and if the insulation resistance R does not meet the reference resistance Rref (NO in step S6), the substrate P has an insulation defect. (Step S9), and the process is terminated.

On the other hand, if the insulation resistance R is equal to or higher than the reference resistance Rref (YES in step S6), the determination unit 72 determines that the insulation state between the first pattern and the second pattern is good, and all conductor patterns to be inspected. It is determined whether or not the insulation inspection has been completed (step S7). If the insulation inspection is completed for all conductor patterns (YES in step S7), the determination unit 72 determines that the substrate P is a non-defective product (step S10) and ends the process.

On the other hand, if there is a conductor pattern for which the insulation inspection has not been completed in step S7 (NO in step S7), the inspection control unit 71 is the first of the conductor patterns for which the insulation inspection has not been completed. A pattern is selected, a second pattern is selected from conductor patterns other than the first pattern (step S8), and the processes after step S3 are executed again.

On the other hand, when the occurrence of spark or partial discharge is detected by the discharge detection unit 6 in step S4 (YES in step S4), the discharge detection unit 6 outputs a discharge detection signal indicating that spark or partial discharge has occurred. It is output to the switching elements SW1 and SW2, the power supply unit 2, and the control unit 7.

As a result, the switching element SW1 is turned on (forced discharge step), the switching element SW2 is turned off, the power supply unit 2 stops switching, and the output of the voltage V is stopped or lowered (power supply control step) (step S11). The control unit 7 is notified of the occurrence of a spark or a partial discharge, and the determination unit 72 determines that the substrate P has an insulation defect (step S9), and ends the process.

FIG. 4 is an explanatory diagram for explaining the circuit operation of the forced discharge process and the power supply control process in step S11. When the switching element SW1 is turned on, the probe Pr1 connected to the conductor pattern P1 (first pattern) and the probe Pr2 connected to the conductor pattern P2 (second pattern) are conducted by the conductive path L1 via the switching element SW1. , The conductor pattern P1 and the conductor pattern P2 are quickly set to the same potential (forced discharge step). As a result, it is possible to prevent the spark or partial discharge from continuing for a long time or the spark or partial discharge from being repeated, so that the possibility that the damage to the substrate due to the discharge such as the spark or partial discharge spreads is reduced.

Further, when the switching element SW2 is turned off, the power supply unit 2 is separated from the conductor pattern P1, so that the voltage output of the power supply unit 2 between the conductor patterns P1 and P2 is stopped (power supply control step). As a result, it is possible to prevent the spark or partial discharge from continuing for a long time or the spark or partial discharge from being repeated, so that the possibility that the damage to the substrate due to the discharge such as the spark or partial discharge spreads is reduced.

Further, when the switching operation of the power supply unit 2 is stopped, the voltage output of the power supply unit 2 between the conductor patterns P1 and P2 is stopped or reduced. As described in Japanese Patent Application Laid-Open No. 2001-178137, for example, the switching power supply circuit used in the power supply unit 2 uses a rectifying circuit for rectifying a commercial AC power supply voltage and a capacitor for smoothing the rectified voltage to obtain an AC voltage. It is equipped with a conversion circuit that converts the converted DC voltage into a DC voltage, and a boost chopper circuit that chops the converted DC voltage by the switching operation of the switching element, boosts it with a choke coil, smoothes it with a power supply smoothing capacitor, and outputs it.

Therefore, even if the switching operation of the power supply unit 2 is stopped, the voltage is maintained by the charge charge of the power supply smoothing capacitor, so that it takes time for the output voltage of the power supply unit 2 to decrease. Further, even if the power supply circuit has a method different from that of the switching power supply circuit as described above, since a smoothing capacitor is usually provided in the output stage of the power supply circuit, even if the operation of the power supply circuit is stopped, the operation of the power supply circuit may be stopped. It takes time for the output voltage to drop.

Further, in the switching power supply circuit provided with the conversion circuit and the step-up chopper circuit as described above, the step-up by the step-up chopper circuit is stopped by stopping the switching operation, and the output voltage is lowered. However, even if the switching operation is stopped, the DC conversion by the conversion circuit may continue, and the output of the DC-converted voltage may continue.

Even in such a case, when the occurrence of spark or partial discharge is detected in step S4, the switching element SW2 is turned off and the power supply unit 2 is disconnected from the positive side wiring Lp, so that the power supply voltage by the power supply unit 2 Immediately stop the supply, reduce the risk of spark or partial discharge continuing for a long time, repeated spark or partial discharge, and reduce the risk of spreading damage to the substrate due to discharge such as spark or partial discharge. be able to.

Further, since the switching element SW2 opens and closes the conductive path from the power supply unit 2 to the first or second pattern to be inspected at a position different from the conductive path L1 conducted by the switching element SW1, the switching element SW2 is turned off. Even if it is (open), the discharge of the charges charged in the first and second patterns by the switching element SW1 is not hindered.

In step S4, it is not always necessary to detect both the spark and the partial discharge. The discharge detection unit 6 executes only the detection of the spark, and if the spark is detected (YES in step S4), the process proceeds to step S11, and if the spark is not detected (NO in step S4), the process proceeds to step S5. good. Alternatively, the discharge detection unit 6 executes only the detection of the partial discharge, and if the partial discharge is detected (YES in step S4), the process proceeds to step S11, and if the partial discharge is not detected (NO in step S4), the process proceeds to step S5. You may migrate.

Further, the power supply unit 2 is not necessarily limited to the switching power supply circuit, and the method of stopping or lowering the voltage output of the power supply unit 2 is not limited to stopping the switching operation. For example, the voltage output of the power supply unit 2 may be stopped or reduced by cutting off the supply of the primary side power supply voltage to the power supply unit 2.

Further, it is not always necessary to include the switching element SW2. When the switching element SW2 is not provided, the electric charge stored in the smoothing capacitor of the output stage of the power supply unit 2 is discharged by the switching element SW1, and the voltage drops rapidly. As a result, it is possible to reduce the risk that the spark or partial discharge continues for a long time or the spark or partial discharge is repeated, and it is possible to reduce the risk that the damage to the substrate due to the discharge such as the spark or partial discharge spreads.

Further, it is not always necessary to include the switching element SW1. Even if the switching element SW1 is not provided, if the occurrence of spark or partial discharge is detected in step S4, the power supply voltage supply is stopped by turning off the switching element SW2, or the output voltage is stopped or lowered by the power supply unit 2. As a result of reducing the new power supply from the power supply unit 2, the risk of spark or partial discharge continuing for a long time or repeated spark or partial discharge is reduced, and spark or partial discharge, etc. It is possible to reduce the risk of spreading damage to the substrate due to the discharge of.

1 Insulation inspection device 2 Power supply unit 3 Current detection unit 4 Voltage detection unit 5 Switching circuit unit 6 Discharge detection unit 7 Control unit 61 Current detection circuit 62 Voltage detection circuit 63 High-speed AD converter 71 Inspection control unit 72 Judgment unit L1 Conductive path Lm Minus Side wiring Lp Plus side wiring P Board P1 Conductor pattern P1, P2, P3, P4 Conductor pattern Pr1, Pr2, Pr3, Pr4 Probe R Insulation resistance Rref Reference resistance SW1 Switching element (forced discharge part)
SW2 switching element (switch)

Claims (5)

A plurality of probes for contacting the plurality of conductor patterns on the substrate to be inspected in which a plurality of conductor patterns are formed, and a plurality of probes.
A power supply unit that outputs a voltage between the first pattern, which is one of the plurality of conductor patterns, and the second pattern, which is any one other than the first pattern, via the plurality of probes. ,
A discharge detection unit that detects the occurrence of at least one of a spark and a partial discharge between the first pattern and the second pattern.
A power supply control unit that stops or reduces the voltage output of the power supply unit when at least one of the occurrences is detected by the discharge detection unit .
An insulation inspection device including a forced discharge unit that conducts the first pattern and the second pattern when at least one of the occurrences is detected by the discharge detection unit. A switch that opens and closes the conductive path from the power supply section to at least one of the first pattern and the second pattern at a position different from the conduction path conducted by the forced discharge section in order to output the voltage. Prepare,
The insulation inspection device according to claim 1 , wherein the power supply control unit stops the voltage output by the power supply unit by opening the switch when at least one of the occurrences is detected by the discharge detection unit. The insulation inspection device according to claim 1 or 2 , wherein the discharge detection unit is configured by using an FPGA, an ASIC, or a microcomputer that uses or does not use a real-time OS. The insulation inspection according to any one of claims 1 to 3 , further comprising a determination unit for determining the insulation between the patterns based on the voltage and current between the first pattern and the second pattern. Device. A voltage between the first pattern, which is one of the plurality of conductor patterns, and the second pattern, which is any other than the first pattern, on the substrate to be inspected in which a plurality of conductor patterns are formed. Power output process to output
A discharge detection step of detecting the occurrence of at least one of a spark and a partial discharge between the first pattern and the second pattern,
When the occurrence of at least one of the above is detected, the power supply control step of stopping or lowering the voltage output by the power supply output step and the power supply control step.
An insulation inspection method including a forced discharge step of conducting the first pattern and the second pattern when at least one of the occurrences is detected by the discharge detection step .

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