KR102627308B1 - Insulation checking device and insulation checking method - Google Patents

Abstract

[Project] Provide an insulation inspection device and an insulation inspection method that can reduce the risk of increased damage to the board due to discharge.
[Solution] The insulation inspection device 1 includes probes Pr1 to Pr4 for contacting the conductor patterns P1 to P4 on the substrate P to be inspected, and probes Pr1 to Pr4. , a power supply unit 2 that outputs a voltage between any first pattern among the conductor patterns P1 to P4 and any second pattern other than the first pattern, and sparks and parts between the first pattern and the second pattern. It is provided with a discharge detection unit (6) that detects the occurrence of at least one of the discharges and stops or reduces the voltage output by the power supply unit (2) when the occurrence of at least one of the discharges is detected.

Description

Insulation test device and insulation test method {INSULATION CHECKING DEVICE AND INSULATION CHECKING METHOD}

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

Conventionally, a direct current voltage is supplied from the power supply between a pair of conductor patterns, the insulation resistance value is calculated from the voltage and current values obtained between the conductor patterns, and when the calculation of the resistance value is completed, the power supply is controlled to determine the applied voltage value. A technique for lowering is known (for example, see Patent Document 1). Patent Document 1 states that, when a detection signal is output from the discharge detection unit from immediately after the start of output of direct current voltage by the power supply unit until the determination of the insulation state based on the resistance value is completed, there is a gap between a pair of conductor patterns. It is described that detecting that a spark has occurred is described.

Japanese Patent Publication No. 2015-10880 (paragraphs 0043, 0044)

However, when sparks occur between conductor patterns, the resistance value between conductor patterns may decrease due to carbonization or contamination of the substrate between conductor patterns. Additionally, there are cases where sparks cause defects in the conductor pattern. Additionally, if a defect occurs in the conductor pattern, there is a risk that sparks may become more likely to be generated at the edge of the missing portion, or the resistance value between the conductor patterns may decrease, making it more likely that sparks will be generated.

In this way, if discharges such as sparks continue for a long time or discharges such as sparks are repeated, there is a problem that damage to the substrate increases.

The purpose of the present invention is to provide an insulation inspection device and an insulation inspection method that can reduce the risk of increased damage to the substrate due to discharge.

An insulation inspection device according to the present invention includes a plurality of probes for contacting the plurality of conductor patterns in a substrate to be inspected on which a plurality of conductor patterns are formed, and a plurality of probes for contacting the plurality of conductor patterns among the plurality of conductor patterns. , a power supply unit that outputs a voltage between a first pattern and a second pattern other than the first pattern, and a device that detects the occurrence of at least one of a spark and a partial discharge between the first pattern and the second pattern. It is provided with a discharge detection unit and a power control unit that stops or reduces voltage output from the power supply unit when the occurrence of at least one of the above is detected by the discharge detection unit.

In addition, the insulation inspection method according to the present invention is a test object substrate on which a plurality of conductor patterns are formed, between any first pattern among the plurality of conductor patterns and any second pattern other than the first pattern. a power output process for outputting a voltage; a discharge detection process for detecting the occurrence of at least one of a spark and a partial discharge between the first pattern and the second pattern; and when the occurrence of at least one of the sparks and partial discharges is detected, the power supply It includes a power control process that stops or reduces the voltage output by the output process.

According to these configurations, if the occurrence of at least one of sparks and partial discharges between the first pattern and the second pattern is detected, and at least one of the sparks and partial discharges occurs between the first and second patterns that are subject to insulation inspection, The occurrence of at least one of the above is detected, and the voltage output between the first pattern and the second pattern is stopped or lowered for insulation inspection. As a result, the risk that discharges such as sparks will continue for a long time or that discharges will be repeated can be reduced, thereby reducing the risk that damage to the substrate due to discharge will increase.

In addition, it is preferable to further include a forced discharge unit that causes the first pattern and the second pattern to conduct when the at least one occurrence 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 capacitance of the first pattern and the second pattern is discharged, and the potentials of the first pattern and the second pattern become equal. Therefore, the risk that discharges such as sparks will continue for a long time or that discharges will be repeated can be reduced, thereby reducing the risk that damage to the substrate due to discharge will increase.

In addition, in order to output the voltage, a switch is provided to open and close the conductive path from the power supply unit to at least one of the first pattern and the second pattern at a position different from the conductive path conducted by the forced discharge unit. Preferably, the power control unit stops voltage output by the power supply unit by opening the switch when the at least one occurrence is detected by the discharge detection unit.

According to this configuration, when at least one of a spark and a 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 voltage output of the power supply unit between the first and second patterns is rapid. It stops. This prevents sparks or partial discharges from continuing for a long time or repeating sparks or partial discharges, thereby reducing the risk of increased damage to the substrate due to discharges such as sparks or partial discharges. In addition, the switch opens and closes the conductive path from the power supply unit to the first or second pattern to be inspected at a position different from the conductive path that serves as the discharge path by the forced discharge unit, so even if the switch is open, the first and second patterns are connected to each other. Discharge of the charge charged in the second pattern is not hindered.

The discharge detection unit is preferably configured using an FPGA, ASIC, or a microcomputer that uses a real-time OS or no OS.

According to this configuration, it is possible to determine whether a spark has occurred at a higher speed compared to the case where the judgment is made on a computer using an information system OS such as a personal computer, thereby reducing the risk of increased damage to the board due to sparks. It is easy to do.

In addition, it is preferable to further include a determination unit that determines insulation between the first pattern and the second pattern 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 insulation inspection method configured as described above can reduce the risk of increased damage to the substrate due to discharge.

1 is a schematic configuration diagram of an insulation inspection device using an insulation inspection method according to an embodiment of the present invention.
FIG. 2 is a block diagram showing an example of the configuration of the discharge detection unit shown in FIG. 1.
FIG. 3 is a flowchart showing an example of the operation of the insulation inspection device shown in FIG. 1.
4 is an explanatory diagram for explaining the circuit operation of the power control process.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment concerning this invention will be described based on the drawings. In addition, in each drawing, components assigned the same reference numerals indicate the same configuration and their description is omitted. 1 is a schematic configuration diagram of an insulation inspection device 1 using an insulation inspection method according to an embodiment of the present invention. FIG. 1 shows a state in which a substrate P to be inspected is connected to an insulation inspection device 1 for insulation inspection.

In addition, 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, and a touch board. Various substrates may be used, such as transparent conductive plates for panels, package substrates for semiconductor packages, film carriers, semiconductor wafers, semiconductor chips, and CSP (Chip Size Package).

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, and Pr4, a power supply unit 2, a current detection unit 3, a voltage detection unit 4, a switching circuit unit 5, and a discharge detection unit ( 6) (power control unit), a switching element (SW1) (forced discharge unit), a switching element (SW2) (switch), and a control unit (7).

The probes Pr1, Pr2, Pr3, and Pr4 are contactors that contact the conductor patterns P1, P2, P3, and P4 of the substrate P, respectively. Additionally, the number of conductor patterns and probes may be plural, and is not limited to four. The switching elements SW1 and SW2 are configured using, for example, semiconductor switching elements such as transistors or relay switches.

The power supply unit 2 is a power circuit that outputs a voltage for insulation testing between conductor patterns of an inspection target. The power supply unit 2 is a direct current constant voltage power supply circuit configured using, for example, a switching power supply circuit. The positive side output terminal of the power supply section 2 is connected to the switching circuit section 5 via the switching element SW2, the discharge detection section 6, and the positive side wiring Lp. The negative side output terminal of the power supply section 2 is connected to the switching circuit section 5 via the current detection section 3 and the negative side wiring Lm. Additionally, the minus side output terminal of the power supply unit 2 is connected to the circuit ground, and the minus side wiring Lm is connected to the circuit ground via the current detection unit 3.

Additionally, the power supply unit 2 is not necessarily limited to a constant voltage power supply circuit. The power supply unit may be a variable voltage source, and, for example, as described in Japanese Patent Application Laid-Open No. 2015-45542, it includes a constant current source and a limiter circuit that limits the output voltage of the constant current source so that it does not exceed a predetermined upper limit voltage. You can combine them to create a power supply. As the power supply unit 2, for example, a boost-type switching power supply circuit described in Japanese Patent Application Laid-Open No. 2001-178137 can be used.

The current detection unit 3 is constructed using, for example, a shunt resistor, a Hall element, an analog/digital converter, etc. The current detection unit 3 detects the current I flowing through the minus side wiring Lm and outputs a signal representing the detected current I to the control unit 7.

The voltage detection unit 4 is configured using, for example, a voltage dividing resistor or an analog/digital converter. The voltage detection unit 4 detects the voltage V between the positive side wiring Lp and the circuit ground, and outputs a signal representing the detected voltage V to the control unit 7. Since the circuit ground is connected to the minus side wiring Lm via the current detection section 3, the voltage detection section 4 determines the voltage (V) between the plus side wiring Lp and the minus side wiring Lm, In other words, the voltage (V) between the conductor patterns of the inspection target is detected.

The switching circuit section 5 is configured using, for example, a plurality of switching elements that are turned on and off in accordance with a control signal from the control section 7. The switching circuit section 5 determines the connection relationship between the plus side wiring Lp and the probes Pr1, Pr2, Pr3, and Pr4 and the connection relationship between the minus side wiring Lm and the probe Pr1 by combining the on and off states of each switching element. , Pr2, Pr3, Pr4) connection relationships can be switched.

Accordingly, for example, when performing an insulation test 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, Connect the probe (Pr2) and the minus side wire (Lm). 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 conductor patterns P1 and P2 are detected by the current detection unit 3. The voltage between P2) is detected by the voltage detection unit 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.

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

Hereinafter, to simplify the explanation, an insulation test between the conductor patterns P1 and P2 is exemplified, and the probe Pr1 and the plus side wiring Lp are connected by the switching circuit portion 5, and the probe Pr2 is connected to the positive side wiring Lp. ) and the minus side wiring (Lm) are connected (Figure 1).

For example, one end of the switching element SW1 is connected to the power supply unit 2 via the switching element SW2 and to the plus 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 in accordance with 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), is connected to the circuit ground, the current detection unit (3), the switching circuit unit (5), and the probe (Pr1, It conducts through Pr2). As a result, the conductor patterns (P1, P2) immediately become approximately the same potential.

The switching element SW1 corresponds to an example of a forced discharge unit. Additionally, the forced discharge unit is not limited to the example comprised of the switching element SW1 alone. For example, the forced discharge unit may be formed 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 conductor patterns to be inspected, for example, between conductor patterns P1 and P2. When the discharge detection unit 6 detects the occurrence of a 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 C60664-1 (IEC60664-1).

In addition, when the discharge detection unit 6 detects the occurrence of a spark or partial discharge, it outputs a discharge detection signal to the power supply unit 2, thereby stopping the switching operation of the power supply unit 2 and reducing the voltage output of the power supply unit 2. Stop it. In addition, when the discharge detection unit 6 detects the occurrence of a spark or partial discharge, it outputs a discharge detection signal to the switching element SW2, thereby separating the power supply unit 2 from the conductor pattern P1 and separating the power supply unit 2 from the conductor pattern P1. stops the voltage output. 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 a spark or partial discharge is detected.

Additionally, when the discharge detection unit 6 detects the occurrence of a 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 the 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. 1. 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 sends a voltage signal according to the current value to the high-speed AD converter 63. ) is output. 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 (V) between the circuit ground and the positive wiring (Lp), that is, the voltage (V) between the conductor patterns (P1, P2), and converts a voltage signal according to the voltage value to a high-speed AD converter ( 63). As the voltage detection circuit 62, for example, a voltage dividing resistor can be used, or a wiring that connects the positive side wiring (Lp) directly to the high-speed AD converter 63 may be used.

The high-speed AD converter 63 is a so-called analog/digital converter, and converts the voltage signals output from the current detection circuit 61 and the voltage detection circuit 62 into digital values and outputs them to the FPGA 64. The higher the conversion speed of the high-speed AD converter 63, the more desirable it is.

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. For example, the FPGA 64 may determine that a spark has occurred when the current I detected by the current detection circuit 61 increases instantaneously. Alternatively, the FPGA 64 may determine that a spark has occurred, for example, when the voltage V detected by the voltage detection circuit 62 drops momentarily.

Alternatively, in the FPGA 64, for example, after the power supply unit 2 starts supplying current to the conductor pattern to be inspected, the current I measured by the current detection circuit 61 falls below a preset threshold. If the time taken to do so exceeds a preset regulation time, it may be determined that a spark or partial discharge has occurred.

When the occurrence of sparks and partial discharges is determined by the FPGA 64, for example, a personal computer using an information system OS (Operating System) such as the control unit 7 described later determines the occurrence of sparks and partial discharges. Compared to , it becomes possible to determine the occurrence of sparks and partial discharges in a short time. In addition, the discharge detection unit 6 uses an application specific integrated circuit (ASIC), a real-time operating system (OS) instead of the FPGA 64, or a microcomputer that does not use an OS to detect sparks and partial discharges. You can judge the occurrence.

In addition, the discharge detection unit 6 does not include the current detection circuit 61 and the voltage detection circuit 62, and instead, the current (I) detected by the current detection unit 3 and the voltage detection unit 4 , the occurrence of sparks and partial discharges may be determined based on the voltage (V).

Additionally, the discharge detection unit just needs to be able to 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 an FPGA, and various detection methods can be used. The discharge detection unit is a method for detecting the occurrence of sparks, for example, Japanese Patent No. 3546046, Japanese Patent No. 3953087, Japanese Patent No. 4369949, Japanese Patent No. 4918339, and Japanese Patent No. 5866943. , the spark may be detected using the spark detection method described in Japanese Patent Laid-Open No. 2015-10880 and Japanese Patent Laid-Open No. 2015-45542.

The discharge detection unit may detect the occurrence of partial discharge based on the temporal change in the current I measured by the current detection circuit 61, as described in, for example, Japanese Patent Application Laid-Open No. 2015-45542. . In addition, 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 detecting electromagnetic waves generated when a partial discharge occurs, thereby determining the occurrence of the partial discharge. Occurrence may be detected. Alternatively, the discharge detection unit may detect partial discharge based on a method described in standards such as JIS C60664-1 (IEC60664-1).

In addition, the discharge detection unit is not limited to the example of detecting the occurrence of sparks and partial discharges, and may be configured to detect only either sparks or partial discharges.

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 nonvolatile memory unit that stores a predetermined control program, and these. It is composed of peripheral circuits, etc. The control unit 7 is configured using, for example, a personal computer using an information OS (Operating System). The control unit 7 functions as the inspection control unit 71 and the judgment 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 among the plurality of conductor patterns formed on the substrate P, and switches the positive side wiring Lp by the switching circuit unit 5. is connected to the first pattern, the minus side wiring Lm is connected to the second pattern, and the power supply unit 2 outputs a voltage V between the first pattern and the second pattern.

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. judge. Specifically, the determination unit 72 calculates the insulation resistance (R) between the first pattern and the second pattern from the current (I) and voltage (V) based on the following equation (1).

Insulation resistance (R)=V/I... (One)

Then, the determination unit 72 compares the preset reference resistance (Rref) and the insulation resistance (R), and determines that the insulation condition is good if the insulation resistance (R) is more than the reference resistance (Rref), and the insulation resistance ( If R) does not reach the reference resistance (Rref), it is judged to be an insulation defect.

In addition, the insulation inspection device 1 does not need to be provided with 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. 1. First, in the initial state, the switching element SW1 is off, the switching element SW2 is 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 plus side wiring Lp and connects the second pattern and the minus side wiring Lm by the switching circuit section 5. 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 output process).

When voltage V is applied between the first pattern and the second pattern, the stray capacitance of the first pattern and the second pattern is charged, and the voltage between the first pattern and the second pattern increases. Therefore, the test control unit 71 detects discharge from the discharge detection unit 6, for example, until a preset waiting time elapses after the voltage is applied, or until the detection voltage of the voltage detection unit 4 becomes stable. Monitor whether a detection signal is detected (step S4).

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

Next, the determination unit 72 compares the reference resistance (Rref) and the insulation resistance (R) (step S6: judgment process), and if the insulation resistance (R) does not reach the reference resistance (Rref) (step S6: " "No"), the substrate P is determined to have poor insulation (step S9), and the process ends.

On the other hand, if the insulation resistance (R) is equal to or greater 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 the inspection target It is determined whether the insulation test has been completed for the entire conductor pattern (step S7). When the insulation test for the entire conductor pattern is completed (YES in step S7), the judgment unit 72 determines that the substrate P is a good product (step S10) and ends the process.

On the other hand, if there remain conductor patterns for which the insulation test has not yet been completed in step S7 (“No” in step S7), the test control unit 71 selects a new first pattern from among the conductor patterns for which the insulation test has not yet been completed. Then, the second pattern is selected from the conductor patterns other than the first pattern (step S8), and the processing from step S3 is performed again.

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

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

Figure 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 switched on to the switching element (SW1). ), the conductor pattern P1 and the conductor pattern P2 are quickly brought to the same potential (forced discharge process). This prevents sparks or partial discharges from continuing for a long time or repeating sparks or partial discharges, thereby reducing the risk of increased damage to the substrate due to discharges such as sparks or partial discharges.

Additionally, when the switching element SW2 is turned off, the power supply unit 2 is separated from the conductor pattern P1, and thus the voltage output of the power supply unit 2 between the conductor patterns P1 and P2 is stopped (power control process). . This prevents sparks or partial discharges from continuing for a long time or repeating sparks or partial discharges, thereby reducing the risk of increased damage to the substrate due to discharges such as sparks or partial discharges.

Additionally, 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 decreased. The switching power supply circuit used in the power supply unit 2, as described in, for example, Japanese Patent Application Laid-Open No. 2001-178137, consists of a rectifier circuit that rectifies the commercial AC power supply voltage and a condenser that smoothes the rectified voltage. It is equipped with a conversion circuit that converts alternating current voltage into direct current voltage, and a step-up chopper circuit that chops the converted direct current voltage through the switching operation of a switching element, boosts it with a choke coil, and outputs it after smoothing it with a power smoothing condenser.

Therefore, even if the switching operation of the power source unit 2 stops, the voltage is maintained by the charged charge of the power supply smoothing capacitor, so it takes time for the output voltage of the power source unit 2 to decrease. In addition, even if the power supply circuit is of a different type from the switching power supply circuit described above, a smoothing capacitor is usually installed at the output terminal of the power supply circuit, so even if the operation of the power supply circuit is stopped, it takes time for the output voltage to decrease. It takes.

In addition, in the switching power supply circuit including the conversion circuit and the step-up chopper circuit as described above, when the switching operation is stopped, the boosting by the step-up chopper circuit is stopped, and the output voltage decreases. However, even if the switching operation is stopped, direct current conversion by the conversion circuit continues, and the output of the converted direct current voltage may continue.

Even in this case, when the occurrence of a 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 is supplied by the power supply unit 2. By stopping immediately, the risk of sparks or partial discharges continuing for a long time or sparks or partial discharges being repeated can be reduced, thereby reducing the risk of damage to the substrate expanding due to discharges such as sparks or partial discharges.

In addition, 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 different position from the conductive path L1 conducted by the switching element SW1, Even if the switching element SW2 is turned off (open), the discharge of the charges charged in the first and second patterns by the switching element SW1 is not impaired.

Additionally, in step S4, it is not necessarily necessary to detect both spark and partial discharge. The discharge detection unit 6 performs only spark detection, and if a spark is detected (“Yes” in step S4), the process proceeds to step S11. If a spark is not detected (“No” in step S4), the process proceeds to step S5. You may fulfill it. Alternatively, the discharge detection unit 6 performs only detection of partial discharge, and if partial discharge is detected (“Yes” in step S4), the process proceeds to step S11, and if no partial discharge is detected (“No” in step S4) ) You may proceed to step S5.

In addition, the power supply unit 2 is not necessarily limited to a 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 lowered by blocking the supply of the primary power supply voltage to the power supply unit 2.

Additionally, it is not necessary to necessarily include a switching element (SW2). When the switching element SW2 is not provided, the charge stored in the smoothing capacitor at the output stage of the power supply unit 2 is discharged from the switching element SW1, causing the voltage to quickly drop. As a result, the risk that sparks or partial discharges will continue for a long time or that sparks or partial discharges will repeat can be reduced, thereby reducing the risk that damage to the substrate will increase due to discharges such as sparks or partial discharges.

Additionally, it is not necessary to necessarily include a switching element (SW1). Even if the switching element SW1 is not provided, when the occurrence of a spark or partial discharge is detected in step S4, the supply of the power supply voltage is stopped by turning off the switching element SW2, or the output voltage from the power supply unit 2 is stopped. As a result of stopping or lowering, the supply of new power from the power supply unit 2 is reduced, thereby reducing the risk that sparks or partial discharges will continue for a long time or that sparks or partial discharges will be repeated, thereby reducing the risk of sparks or partial discharges etc. This can reduce the risk of increased damage to the substrate.

1: Insulation inspection device
2: Power section
3: Current detection unit
4: Voltage detection unit
5: Switching circuit part
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: Challenge Path
Lm: Minus side wiring
Lp: plus side wiring
P: substrate
P1: Conductor pattern
P1, P2, P3, P4: Conductor pattern
Pr1, Pr2, Pr3, Pr4: Probes
R: insulation resistance
Rref: reference resistance
SW1: Switching element (forced discharge part)
SW2: switching element (switch)

Claims (6)

In a substrate to be inspected on which a plurality of conductor patterns are formed, a plurality of probes for contacting the plurality of conductor patterns;
a power supply unit that outputs a voltage between a first pattern among the plurality of conductor patterns and a second pattern other than the first pattern through 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 voltage output from the power supply unit when the at least one occurrence is detected by the discharge detection unit;
An insulation inspection device comprising a forced discharge unit that causes the first pattern and the second pattern to conduct when the at least one occurrence is detected by the discharge detection unit. delete The method of claim 1, wherein in order to output the voltage, a conductive path from the power supply unit to at least one of the first pattern and the second pattern is opened and closed at a different position from a conductive path conducted by the forced discharge unit. Provided with more switches,
The insulation inspection device wherein the power control unit stops voltage output by the power supply unit by opening the switch when the at least one occurrence is detected by the discharge detection unit. The insulation inspection device according to claim 1 or 3, wherein the discharge detection unit is configured using an FPGA, ASIC, or a microcomputer that uses a real-time OS or does not use an OS. The insulation inspection device according to claim 1 or 3, further comprising a determination unit that determines insulation between the first pattern and the second pattern based on the voltage and current between the first pattern and the second pattern. A power output process for outputting a voltage between a first pattern among the plurality of conductor patterns and a second pattern other than the first pattern in a substrate to be inspected on which a plurality of conductor patterns are formed;
A discharge detection process for detecting 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 process that stops or reduces voltage output by the power supply output process when the at least one occurrence is detected by the discharge detection process;
An insulation inspection method comprising a forced discharge step of bringing the first pattern and the second pattern into conduction when the at least one occurrence is detected by the discharge detection step.