JP5485099B2 - Circuit board inspection apparatus and circuit board inspection method - Google Patents

Description

  The present invention relates to a circuit board inspection apparatus and a circuit board inspection method for inspecting the quality of a circuit board under predetermined inspection conditions based on a physical quantity when an inspection signal is supplied to a conductor pattern of the circuit board. is there.

  As this type of circuit board inspection apparatus, an insulation inspection apparatus disclosed in Japanese Patent Application Laid-Open No. 2003-172757 is known. This insulation inspection device is composed of a variable voltage source, a voltmeter, a control unit, a spark detection circuit, etc., and determines whether the insulation state between the wiring patterns on the circuit board is good or not, and there is a wiring pattern with a poor insulation state. When it is determined that the circuit board is defective. In addition, the insulation inspection apparatus detects a spark generated between the wiring patterns during the insulation inspection, and determines that the circuit board is defective even when the spark detection circuit detects the spark. Specifically, when a spark occurs due to the application of a DC voltage output from a variable voltage source, the output voltage of the variable voltage source suddenly fluctuates (rapidly decreases), and the spark detection circuit detects this output voltage fluctuation. Output a spark generation signal. Further, the control unit determines that the circuit board is defective when a spark generation signal is output from the spark detection circuit.

JP 2003-172757 A (page 4-5, FIG. 1)

  However, the circuit board inspection apparatus has the following problems. That is, in this circuit board inspection apparatus, when determining the quality of a plurality of circuit boards, a DC voltage of a predetermined level is applied to the wiring pattern to be inspected for a predetermined time, and an insulation state or a spark is determined. The process for determining the presence or absence of occurrence is performed on all circuit boards. That is, the pass / fail judgment for all circuit boards is performed under one predetermined inspection condition. On the other hand, since a physical phenomenon such as a spark is unstable, a spark can be generated by slightly increasing the DC voltage application time or voltage level, or even if a spark does not occur in one inspection, Sparks may occur during inspection. For this reason, some circuit boards that have been determined to be good by this circuit board inspection apparatus are determined to be defective by slightly raising the criteria of the inspection conditions such as the DC voltage application time, voltage level, and number of inspections. There is a possibility that such a circuit board (a circuit board having a potential failure factor) exists, and there is a problem that it is difficult to improve the inspection accuracy. In this case, for example, a circuit having a potential cause of failure by performing a plurality of inspections on one wiring pattern or increasing the application time of a DC voltage applied to the wiring pattern to increase the inspection condition standard. The substrate can be prevented from being determined to be good. However, when the standard of the inspection condition is uniformly increased in this way, it takes a lot of time to inspect one wiring pattern. Therefore, the inspection time for inspecting a large number of circuit boards is prolonged, and the inspection efficiency is increased. This causes the problem of lowering.

  The present invention has been made in view of such problems, and a main object of the present invention is to provide a circuit board inspection apparatus and a circuit board inspection method capable of improving inspection accuracy while suppressing a decrease in inspection efficiency.

  In order to achieve the above object, the circuit board inspection apparatus according to claim 1 measures a physical quantity that accompanies the supply of the inspection signal to the conductor pattern of the circuit board and inspects the quality of the circuit board based on the measured value. A circuit board inspection apparatus including an inspection unit that performs a pass / fail inspection to be performed under a predetermined first inspection condition, wherein the inspection unit performs the pass / fail inspection on a plurality of the same type of circuit boards. When the defect rate of the circuit board at the intermediate time point when the pass / fail inspection for some circuit boards of the plurality of circuit boards is over a first reference rate defined in advance, A first process for changing the inspection condition in the pass / fail inspection to a second inspection condition having a higher standard than the first inspection condition, and a defect rate of the circuit board at the intermediate time point is lower than the first reference rate At least one of the second processes for changing the inspection condition in the pass / fail inspection after the intermediate time point to a third inspection condition having a reference lower than the first inspection condition when the value is equal to or less than a second reference rate defined in advance. Do.

  The circuit board inspection apparatus according to claim 2 is the circuit board inspection apparatus according to claim 1, wherein the first inspection condition, the second inspection condition, and the third inspection condition are supplied to the conductor pattern. The supply time of the inspection signal is defined, the supply time in the second inspection condition is defined to be longer than the supply time in the first inspection condition, and the supply time in the third inspection condition is It is specified to be shorter than the supply time in the first inspection condition.

  The circuit board inspection apparatus according to claim 3 is the circuit board inspection apparatus according to claim 1 or 2, wherein the first inspection condition, the second inspection condition, and the third inspection condition are applied to the conductor pattern. A signal level of the inspection signal to be supplied is defined, the signal level in the second inspection condition is defined to be higher than the signal level in the first inspection condition, and the signal level in the third inspection condition Is defined at a level lower than the signal level in the first inspection condition.

  The circuit board inspection apparatus according to claim 4 is the circuit board inspection apparatus according to any one of claims 1 to 3, wherein the first inspection condition, the second inspection condition, and the third inspection condition are The number of times that the process of supplying the inspection signal and measuring the physical quantity is performed per conductor pattern is defined, and the number of times in the second inspection condition is larger than the number of times in the first inspection condition. The number of times in the third inspection condition is specified to be smaller than the number of times in the first inspection condition.

  The circuit board inspection apparatus according to claim 5 is the circuit board inspection apparatus according to any one of claims 1 to 4, wherein the inspection unit sets the changed inspection condition as the new first inspection condition. Then, at least one of the first process and the second process is performed.

  According to a sixth aspect of the present invention, the circuit board inspection method performs a pass / fail test for measuring a physical quantity that accompanies the supply of the test signal to the conductor pattern of the circuit board and checking the pass / fail of the circuit board based on the measured value. A circuit board inspection method executed under a predetermined first inspection condition, wherein when performing the pass / fail inspection on a plurality of the same type of circuit boards, a part of the plurality of circuit boards When the defect rate of the circuit board at an intermediate time point when the pass / fail inspection for the circuit board is finished is equal to or higher than a first reference rate defined in advance, the inspection condition in the pass / fail inspection after the intermediate time point is higher than the first inspection condition. A first process for changing to a second inspection condition having a high reference, and a defect rate of the circuit board at the intermediate time point is equal to or lower than a second reference rate that is defined in advance to a value lower than the first reference rate The test conditions in the quality inspection of the intermediate time points after performing at least one of a second process of changing to the third inspection condition criteria is lower than the first inspection condition.

  The circuit board inspection apparatus according to claim 1 and the circuit board inspection method according to claim 6, wherein the defect rate of the circuit board at the intermediate time point when the pass / fail inspection for a part of the plurality of circuit boards of the same type is completed is the first reference. The first processing for changing the inspection condition in the pass / fail inspection after the intermediate time point to the second inspection condition whose reference is higher than the first inspection condition when the ratio is equal to or higher than the rate, and the defect rate of the circuit board at the intermediate time point is higher than the first reference rate. At least one of the second processes for changing the inspection condition in the pass / fail inspection after the intermediate time point to the third inspection condition having a lower reference than the first inspection condition when the second reference rate is lower than the second reference rate. Therefore, according to the circuit board inspection apparatus and the circuit board inspection method, when the first process is executed, a circuit having a potential failure factor in the circuit board determined to be good in the quality inspection after the intermediate time point As a result of suppressing the possibility that the substrate is included, inspection accuracy (inspection reliability) can be sufficiently improved accordingly. In addition, according to the circuit board inspection apparatus and the circuit board inspection method, by setting, as the first inspection condition, an inspection condition necessary and sufficient to determine that a circuit board having a potential failure factor is defective. Compared with a configuration in which a pass / fail inspection is performed on a circuit board under an inspection condition having a higher standard than necessary, a decrease in inspection efficiency can be suppressed sufficiently low. Further, according to the circuit board inspection apparatus and the circuit board inspection method, when the second process is executed, the time required for the quality inspection for one circuit board in the quality inspection after the intermediate time point can be shortened. Inspection efficiency can be improved sufficiently.

  According to the circuit board inspection apparatus of the second aspect, the supply time of the inspection signal supplied to the conductor pattern is defined as the first inspection condition, and the supply time of the inspection signal is set as the second inspection condition. By defining the time longer than the supply time in the first inspection condition, and as the third inspection condition, the supply time of the inspection signal is shorter than the supply time in the first inspection condition. The second inspection condition when performing the pass / fail inspection on the circuit board based on the physical quantity generated when the inspection signal is supplied can be reliably and easily set as a higher reference than the first inspection condition. Accordingly, the third inspection condition when performing the pass / fail inspection for the circuit board can be reliably and easily set as a reference lower than the first inspection condition.

  According to the circuit board inspection apparatus of the third aspect, the signal level of the inspection signal supplied to the conductor pattern is defined as the first inspection condition, and the signal level of the inspection signal is defined as the second inspection condition. By defining the signal level higher than the signal level in one inspection condition and defining the signal level of the inspection signal as a third inspection condition lower than the signal level in the first inspection condition, The second inspection condition when performing the pass / fail inspection on the circuit board based on the physical quantity generated when the inspection signal is supplied can be more reliably and easily set as a reference higher than the first inspection condition. The third inspection condition when performing the pass / fail inspection on the circuit board based on the physical quantity can be more reliably and easily set as a reference lower than the first inspection condition.

  According to the circuit board inspection apparatus of the fourth aspect, the number of times that the processing for supplying the inspection signal and measuring the physical quantity as the first inspection condition is performed per conductor pattern is defined. By defining this number of times as the number of times larger than the number of times in the first inspection condition as the inspection condition, and defining this number of times as the number of times smaller than the number of times in the first inspection condition as the third inspection condition. On the other hand, the second inspection condition when performing the pass / fail inspection on the circuit board based on the physical quantity generated when the inspection signal is supplied can be more reliably and easily set as a higher reference than the first inspection condition. Based on this physical quantity, the third inspection condition when performing the pass / fail inspection on the circuit board can be more reliably and easily set as a reference lower than the first inspection condition.

  According to the circuit board inspection apparatus of the fifth aspect, by performing at least one of the first process and the second process using the changed inspection condition as a new first inspection condition, the inspection condition is set at an intermediate time point. When the defect rate of the circuit board changes after the change, the inspection conditions can be changed again according to the change in the failure rate, so that the inspection accuracy can be further improved while further reducing the inspection efficiency. Can do.

1 is a configuration diagram showing a configuration of a circuit board inspection device 1. FIG. 5 is a flowchart of an inspection process 70. It is the 1st explanatory view for explaining the selection method of conductor pattern 81 as inspection conditions. It is the 2nd explanatory view for explaining the selection method of conductor pattern 81 as inspection conditions. It is the 3rd explanatory view for explaining the selection method of conductor pattern 81 as inspection conditions.

  Hereinafter, an embodiment of a circuit board inspection apparatus and a circuit board inspection method will be described with reference to the accompanying drawings.

  First, the configuration of the circuit board inspection apparatus 1 will be described. The circuit board inspection apparatus 1 shown in FIG. 1 has, for example, predetermined inspection conditions (first inspection conditions) for inspecting the quality of the circuit board (bare board) 80 on which the electronic component shown in FIG. 1 is not mounted. It is configured to be executable. Specifically, the circuit board inspection apparatus 1 includes, as an example, a signal generation unit 2, a voltage detection unit 3, a current detection unit 4, a discharge detection unit 5, a substrate holding unit 6, and a carry-in / carry-out mechanism as shown in FIG. 7, a storage unit 8 and a control unit 9 are provided. In this case, the voltage detection unit 3, the current detection unit 4, the discharge detection unit 5, and the control unit 9 constitute an inspection unit.

  The signal generation unit 2 generates and outputs an inspection signal (for example, a direct-current voltage signal) Ve defined within a voltage range of about 50V to 200V under the control of the control unit 9.

  As shown in FIG. 1, the voltage detection unit 3 includes a voltage detection circuit 31 and an A / D converter 32. The voltage detection circuit 31 includes a low-pass filter and a range circuit. The voltage detection circuit 31 is a low frequency voltage between the conductor patterns 81 as a physical quantity generated when the inspection signal Ve is supplied to the conductor pattern 81 of the circuit board 80. Detect (measure) the component. The A / D converter 32 outputs the sampling data Ds1 of the low frequency component of the voltage detected by the voltage detection circuit 31.

  As shown in FIG. 1, the current detection unit 4 includes a current detection circuit 41 and an A / D converter 42. The current detection circuit 41 is configured to include a low-pass filter and a range circuit, and a low current flowing between the conductor patterns 81 as a physical quantity generated when the inspection signal Ve is supplied to the conductor pattern 81 of the circuit board 80. Detect (measure) frequency components. The A / D converter 42 outputs the sampling data Ds2 of the low frequency component of the current detected by the current detection circuit 41.

  The discharge detector 5 detects the occurrence of discharge accompanying the supply of the inspection signal Ve. Specifically, the discharge detector 5 includes a voltage detection circuit 51 and a comparator 52 as shown in FIG. The voltage detection circuit 51 includes a high-pass filter and a range circuit, and a high frequency component of a voltage between the conductor patterns 81 as a physical quantity generated when the inspection signal Ve is supplied to the conductor pattern 81 of the circuit board 80. Is detected (measured). The comparator 52 outputs the detection signal Sd when the value of the high frequency component of the voltage detected by the voltage detection circuit 51 is equal to or higher than the reference value.

  The board holding unit 6 is configured to hold the circuit board 80. The carry-in / carry-out mechanism 7 carries the circuit board 80 to be inspected into the board holder 6 and carries out the circuit board 80 that has been inspected from the board holder 6 under the control of the control unit 9.

  The storage unit 8 stores inspection condition data Dc indicating a first inspection condition, a second inspection condition, and a third inspection condition that are determined in advance as inspection conditions for executing the pass / fail inspection for the circuit board 80. In the circuit board inspection apparatus 1, as a first inspection condition, for example, the supply time of the inspection signal Ve supplied to the conductor pattern 81 is defined as 0.1 second, and the inspection signal Ve at that time is The signal level (voltage value in this example) is defined as 100V. In addition, as the second inspection condition, for example, the supply time of the inspection signal Ve is defined as 0.2 seconds, and the signal level of the inspection signal Ve at that time is defined as 150 V. As the third inspection condition, For example, the supply time of the inspection signal Ve is defined as 0.08 seconds, and the signal level of the inspection signal Ve at that time is defined as 80V. That is, the second inspection condition is defined to have a higher standard than the first inspection condition (in other words, a higher standard for determining good products), and the third inspection condition is lower than the first inspection condition (in other words, , Standards for determining good products are low). In addition, the storage unit 8 stores data indicating whether the insulation state between the conductor patterns 81 is good or not and whether the discharge is generated due to the supply of the inspection signal Ve in accordance with the control of the control unit 9.

  The control unit 9 determines the quality of the insulation state between the conductor patterns 81 on the circuit board 80 based on each physical quantity described above by performing the inspection process 70 shown in FIG. It is determined whether or not a discharge accompanying the supply of Ve has occurred, and further, a quality test for determining the quality of the circuit board 80 is performed based on these determination results.

  In addition, when the control unit 9 performs the inspection process 70 and performs the quality inspection on the plurality of circuit boards 80 of the same type, the control unit 9 performs the quality inspection under the first inspection condition at the beginning of the inspection process 70. When the number of circuit boards 80 that have passed the pass / fail inspection reaches a predetermined number (for example, the number corresponding to 5% of the number of circuit boards 80 to be inspected) (hereinafter, this point is referred to as “intermediate”). When the defect rate of the circuit board 80 is equal to or higher than the first reference rate R1 at the time point), the inspection condition in the pass / fail inspection after the intermediate time point (the pass / fail inspection for the remaining circuit boards 80) is higher than the first inspection condition. Change to a high second inspection condition. Further, when the defect rate of the circuit board 80 is equal to or less than the second reference rate R2 at the intermediate time point, the inspection condition in the pass / fail inspection after the intermediate time point is changed to the third inspection condition whose reference is lower than the first inspection condition. The process for changing the inspection condition in the quality inspection after the intermediate time point from the first inspection condition to the second inspection condition corresponds to the first process, and the inspection condition in the quality inspection after the intermediate time point is changed from the first inspection condition to the third inspection condition. The process for changing to the inspection condition corresponds to the second process.

  Next, referring to the drawings, for example, a circuit board inspection method for inspecting 10000 sheets of the same type of circuit boards 80 using the circuit board inspection apparatus 1 and the operation of the circuit board inspection apparatus 1 at that time To explain. The specified number is defined as 1000 sheets corresponding to 10% of the 10,000 circuit boards 80 to be inspected, the first reference rate R1 is defined as 1%, and the second number described above. It is assumed that the reference rate R2 is defined as 0.1%.

  In this circuit board inspection apparatus 1, when an operation for starting inspection is performed, the control unit 9 starts processing according to the inspection process 70 shown in FIG. In the inspection process 70, the control unit 9 first reads the inspection condition data Dc from the storage unit 8, and specifies the first inspection condition indicated by the inspection condition data Dc (step 71).

  Next, the controller 9 performs a pass / fail inspection for the first circuit board 80 (step 72). Specifically, the control unit 9 controls the loading / unloading mechanism 7 to load the first circuit board 80 into the substrate holding unit 6, and then the control unit 9 controls the probing mechanism (not shown). Then, the probes 21 and 21 are brought into contact with the pair of conductor patterns 81 on the circuit board 80. Next, the control unit 9 controls the signal generation unit 2 to output the inspection signal Ve. In this case, the control unit 9 specifies the supply time of the inspection signal Ve to 0.1 seconds defined in the first inspection condition, and the signal level of the inspection signal Ve is defined in the first inspection condition. Specify 100V. As a result, the detection signal Sd is supplied to each conductor pattern 81 via the probes 21 and 21.

  On the other hand, in the voltage detection unit 3, the voltage detection circuit 31 detects a voltage between the conductor patterns 81, and the A / D converter 32 outputs sampling data Ds 1 of the voltage detected by the voltage detection circuit 31. Further, the current detection circuit 41 of the current detection unit 4 detects a current flowing between the conductor patterns 81, and the A / D converter 42 outputs sampling data Ds 2 of the current detected by the current detection circuit 41. Subsequently, the control unit 9 determines the resistance between the conductor patterns 81 based on the voltage specified from the sampling data Ds1 output by the voltage detection unit 3 and the current specified from the sampling data Ds2 output by the current detection unit 4. Calculate the value. Next, the control unit 9 determines whether or not the calculated resistance value is equal to or greater than the reference value. When the calculated resistance value is equal to or greater than the reference value, the control unit 9 determines that the insulation state between the conductor patterns 81 is good and is less than the reference value. In some cases, it is determined that the insulation state is defective.

  Further, the control unit 9 determines whether or not a discharge has occurred based on the presence or absence of the output of the detection signal Sd from the discharge detection unit 5. Here, when there is no defect in the conductor pattern 81 and no discharge occurs due to the supply of the inspection signal Ve, the voltage between the conductor patterns 81 does not change rapidly, and the detection signal Sd from the discharge detector 5 is detected. Therefore, the control unit 9 determines that no discharge occurs. On the other hand, when a defect such as a short circuit or proximity exists in the conductor pattern 81 and a discharge occurs due to the supply of the inspection signal Ve, and the voltage between the conductor patterns 81 rapidly decreases accordingly, the discharge detector 5 is detected by the voltage detection circuit 51. In this case, when the voltage fluctuation amount is equal to or greater than the reference value, the comparator 52 outputs the detection signal Sd. At this time, the control unit 9 determines the output of the detection signal Sd from the discharge detection unit 5 and determines that a discharge has occurred.

  Subsequently, the control unit 9 changes the combination of the pair of conductor patterns 81, supplies the inspection signal Ve and measures each physical quantity, and determines whether the insulation state between the conductor patterns 81 is good or bad. The presence or absence of occurrence of discharge is determined. Next, the control unit 9 determines the quality of the circuit board 80 when determining the quality of the insulation state and the presence or absence of occurrence of discharge for all the combinations of the pair of conductor patterns 81. In this case, when the control unit 9 determines that any one of the conductor patterns 81 has an insulation state or occurrence of discharge, the control unit 9 determines that the circuit board 80 is defective, and notifies that effect. The data shown is stored in the storage unit 8. Subsequently, the control unit 9 controls the carry-in / carry-out mechanism 7 to carry out the circuit board 80 from the board holding unit 6. Thus, the quality inspection (step 72) for the first circuit board 80 is completed.

  Next, the control unit 9 determines whether or not the number of circuit boards 80 for which the pass / fail inspection has been completed (inspected) has reached a specified number (1000) (step 73). In this case, at this point in time, the quality test for only one circuit board 80 has been completed, so the control unit 9 performs a quality test for the next circuit board 80 (step 72). Thereafter, the control unit 9 repeatedly executes steps 72 and 73 until the number of inspected circuit boards 80 reaches a specified number.

  On the other hand, when it is determined in step 73 that the number of circuit boards 80 that have been inspected has reached the specified number, the control unit 9 determines the time based on the data indicating the result of the pass / fail inspection stored in the storage unit 8. It is determined whether or not the defect rate of the circuit board 80 at (intermediate time) is equal to or higher than the first reference rate R1 (1%) (step 74). At this time, the control unit 9 has a defect rate of the circuit board 80 at the intermediate time point equal to or higher than the first reference rate R1, that is, 10 or more of the 1000 circuit boards 80 that have passed the pass / fail inspection by the intermediate time point. Is determined to be defective, the second inspection condition is specified based on the inspection condition data Dc, and the inspection condition in the pass / fail inspection after the intermediate time is changed from the first inspection condition to the second inspection condition (step 75). .

  Subsequently, the control unit 9 performs a pass / fail test for the remaining circuit boards 80 (the circuit boards 80 for which the pass / fail test has not been completed) (step 76). In this case, the control unit 9 specifies the supply time of the inspection signal Ve output from the signal generation unit 2 to 0.2 seconds defined in the second inspection condition, and sets the signal level of the inspection signal Ve. Specify 150V specified in the second inspection condition.

  Further, the control unit 9 determines whether or not the pass / fail inspection for all the circuit boards 80 is completed every time the pass / fail inspection for one circuit board 80 is completed (the number of circuit boards 80 that have passed the pass / fail inspection is 10,000). (Step 77). In this case, when it is determined that the quality inspection for all the circuit boards 80 has not been completed, the control unit 9 repeatedly executes steps 76 and 77 to determine that the quality inspection for all the circuit boards 80 has been completed. Sometimes, the inspection process 70 ends.

  Here, in general, the higher the defect rate, the higher the defect rate, the circuit board 80 having a potential defect factor among the circuit boards 80 determined to be good. There is a high possibility that the circuit board 80) to be determined exists. In this case, in the configuration in which the pass / fail inspection for all the circuit boards 80 is performed under one inspection condition as in the conventional circuit board inspection apparatus, even if the defect rate at the intermediate time point is high, the pass / fail inspection is performed under the same inspection condition after the intermediate time point. As a result of the inspection, there is a high possibility that many circuit boards 80 having potential failure factors are included in the circuit boards 80 determined to be good, and the inspection accuracy (reliability of inspection) is reduced. There is a risk. On the other hand, in the circuit board inspection apparatus 1, as described above, when the defect rate of the circuit board 80 at the intermediate point is equal to or higher than the first reference rate R1, that is, when the defect rate is relatively high, the quality after the intermediate point is determined. The inspection condition in the inspection is changed to a second inspection condition having a higher standard than the first inspection condition. For this reason, according to the circuit board inspection apparatus 1, the possibility that the circuit board 80 having a potential failure factor is included in the circuit boards 80 determined to be good in the quality inspection after the intermediate time point is suppressed to a low level. As a result, the inspection accuracy can be improved accordingly. Further, according to the circuit board inspection apparatus 1, by setting the inspection conditions necessary and sufficient to determine that the circuit board 80 having a potential failure factor is defective as the first inspection conditions, Compared with a configuration in which pass / fail inspection is performed under inspection conditions with a higher standard than necessary from the start, it is possible to suppress a decrease in inspection efficiency.

  Further, when the control unit 9 determines in step 74 that the defect rate of the circuit board 80 at the intermediate time point is not equal to or higher than the first reference rate R1 (less than the first reference rate R1), the circuit board 80 at the intermediate time point. It is determined whether or not the defective rate is less than or equal to the second reference rate R2 (0.1%) (step 78). At this time, the control unit 9 has a defect rate of the circuit board 80 at the intermediate time point equal to or less than the second reference rate R2, that is, out of 1000 circuit boards 80 for which the pass / fail inspection has been completed by the intermediate time point. When it is determined that the number of samples is one or less, the third inspection condition is specified based on the inspection condition data Dc, and the inspection condition in the pass / fail inspection after the intermediate time is changed from the first inspection condition to the third inspection condition. (Step 79).

  Next, the control unit 9 executes Steps 76 and 77. In this case, the control unit 9 outputs the inspection signal Ve to be output from the signal generation unit 2 when executing the quality test (step 76) for the remaining circuit boards 80 (the circuit board 80 for which the quality test has not been completed). The supply time is specified to 0.08 seconds defined in the third inspection condition, and the signal level of the inspection signal Ve is specified to 80 V defined in the second inspection condition. Subsequently, when the control unit 9 determines in step 77 that the quality inspection for all the circuit boards 80 has been completed, the control process 9 is terminated.

  Here, in the configuration in which the quality inspection for all the circuit boards 80 is uniformly performed under a single predetermined inspection condition as in the conventional circuit board inspection apparatus, when the criterion of the inspection condition is high, the defect at the intermediate time point Even if the rate is low, the pass / fail inspection is performed under a high standard inspection condition after the intermediate time point. As a result, the time required for the pass / fail inspection for one circuit board 80 becomes longer, and the inspection efficiency decreases. On the other hand, in this circuit board inspection apparatus 1, as described above, when the defect rate of the circuit board 80 at the intermediate point is less than or equal to the second reference rate R2, that is, when the defect rate is sufficiently low, the quality after the intermediate point is determined. The inspection condition in the inspection is changed to a third inspection condition whose standard is lower than that of the first inspection condition. For this reason, according to this circuit board inspection apparatus 1, as a result of reducing the time required for the quality inspection for one circuit board 80 in the quality inspection after the intermediate time point, it is possible to sufficiently improve the inspection efficiency. ing.

  In step 74, the control unit 9 determines that the defect rate of the circuit board 80 at the intermediate time point is not equal to or higher than the first reference rate R1 (less than the first reference rate R1). When it is determined that the defect rate of the circuit board 80 is not less than or equal to the second reference rate R2 (exceeds the second reference rate R2), the inspection conditions in the pass / fail inspection after the intermediate time point are not changed (first inspection). Under the conditions, a pass / fail inspection (step 76) for the circuit board 80 is executed. Next, when it is determined that the pass / fail inspection for all the circuit boards 80 has been completed, the control unit 9 ends the inspection process 70.

  As described above, in the circuit board inspection apparatus 1 and the circuit board inspection method, the circuit at the intermediate point in time when the pass / fail inspection for some of the circuit boards 80 is completed when the pass / fail inspection is performed on the plurality of circuit boards 80 of the same type. When the defect rate of the substrate 80 is equal to or higher than the first reference rate R1, the inspection condition in the pass / fail inspection after the intermediate time point is changed to the second inspection condition whose reference is higher than the first inspection condition. Therefore, according to the circuit board inspection apparatus 1 and the circuit board inspection method, the circuit board 80 having a potential failure factor may be included in the circuit boards 80 determined to be good in the quality inspection after the intermediate time point. As a result, the inspection accuracy (inspection reliability) can be sufficiently improved. In addition, according to the circuit board inspection apparatus 1 and the circuit board inspection method, it is possible to set, as the first inspection condition, an inspection condition necessary and sufficient to determine that the circuit board 80 having a potential failure factor is defective. Compared with the configuration in which the pass / fail inspection is performed under an inspection condition having a higher standard than necessary from the start of the inspection step 70, the decrease in inspection efficiency can be suppressed sufficiently low. Further, in the circuit board inspection apparatus 1 and the circuit board inspection method, when the defect rate of the circuit board 80 at the intermediate time point is less than or equal to the second reference rate R2, the inspection condition in the pass / fail inspection after the intermediate time point is higher than the first inspection condition. Change to the third inspection condition with a low standard. For this reason, according to the circuit board inspection apparatus 1 and the circuit board inspection method, it is possible to shorten the time required for the quality inspection of one circuit board 80 in the quality inspection after the intermediate time point, and as a result, the inspection efficiency is sufficiently increased. Can be improved.

  Further, according to the circuit board inspection apparatus 1 and the circuit board inspection method, the supply time of the inspection signal Ve supplied to the conductor pattern 81 is defined as the first inspection condition, and the inspection signal Ve is used as the second inspection condition. Is defined as a time longer than the supply time in the first inspection condition, and as the third inspection condition, the supply time of the inspection signal Ve is defined as a time shorter than the supply time in the first inspection condition. Physical quantities generated when the inspection signal Ve is supplied to the conductor pattern 81 of the substrate 80 (low frequency component of voltage between the conductor patterns 81, low frequency component of current flowing between the conductor patterns 81, and conductor pattern 81) Based on the high-frequency component of the voltage between the second inspection condition and the second inspection condition when performing the pass / fail inspection on the circuit board 80 reliably and easily higher than the first inspection condition. It is possible to be a third test condition reliably and easily lower reference than the first inspection condition in performing the quality inspection of the circuit board 80 on the basis of the physical quantity of the.

  Further, according to the circuit board inspection apparatus 1 and the circuit board inspection method, the signal level of the inspection signal Ve supplied to the conductor pattern 81 is defined as the first inspection condition, and the inspection signal Ve is used as the second inspection condition. Is defined as a level higher than the signal level in the first inspection condition, and as the third inspection condition, the signal level of the inspection signal Ve is defined as a level lower than the signal level in the first inspection condition. The second inspection condition when executing the pass / fail inspection for the circuit board 80 based on the physical quantity generated when the inspection signal Ve is supplied to the conductor pattern 81 of the substrate 80 is more reliably and easily made than the first inspection condition. Whether the third inspection condition can be set to a high standard and the third inspection condition for executing the quality inspection for the circuit board 80 based on the physical quantity is more reliable. It is possible to easily lower reference than the first inspection condition.

  The circuit board inspection apparatus 1 and the circuit board inspection method described above are merely examples, and can be changed as appropriate. In the above example, both the supply time of the inspection signal Ve and the signal level of the inspection signal Ve are defined as the inspection conditions in the pass / fail inspection. However, the configuration and method of defining only one of these as the inspection conditions is described. It can also be adopted.

  Further, the inspection condition is not limited to the supply time of the inspection signal Ve and the signal level of the inspection signal Ve. For example, the number of times that the process of supplying each of the physical quantities by supplying the inspection signal Ve is performed for each conductor pattern 81 (hereinafter, also referred to as “the number of processes per conductor pattern 81”) is inspected. It is defined as a condition, and this number of times can be made different in the first inspection condition, the second inspection condition and the third inspection condition. As a first specific example of this configuration and method, as the first inspection condition, the number of times that the process of supplying each of the physical quantities by supplying the inspection signal Ve is performed per pair of conductor patterns 81 is defined as two times. Then, as the second inspection condition, this number of times is defined as three times (the number of times greater than the number of times in the first inspection condition), and as the third inspection condition, this number of times is one time (less than the number of times in the first inspection condition) The configuration and the method specified in the number of times) can be adopted. Also in such a configuration and method, the second inspection condition for performing the pass / fail inspection for the circuit board 80 based on the physical quantity generated when the inspection signal Ve is supplied to the conductor pattern 81 of the circuit board 80 is further set. It is possible to make the reference higher than the first inspection condition reliably and easily, and the third inspection condition when performing the pass / fail inspection for the circuit board 80 based on the physical quantity is more reliably and easily performed. Can be a lower standard.

  In addition, as a second specific example of the configuration and method in which the number of processes per one conductor pattern 81 is made different in the first inspection condition, the second inspection condition, and the third inspection condition, the following configuration and method are as follows. Can be adopted. In this configuration and method, the method of supplying the inspection signal Ve and selecting the conductor pattern 81 to be measured for each physical quantity is defined as the inspection condition, and the first inspection condition, the second inspection condition, and the third inspection condition By making the selection methods different from each other, the number of processes per conductor pattern 81 under each inspection condition is made different. More specifically, as shown in FIGS. 3 to 5, a part of each conductor pattern 81 in a circuit board 80 having M conductor patterns 81 (10 in the example of FIGS. 3 to 5) is used. The first group is selected and part or all of the other conductor patterns 81 excluding the first group of conductor patterns 81 are selected as the second group, and the first group of conductor patterns 81 are set to the same potential and the first group. A measurement process for measuring each physical quantity by supplying an inspection signal Ve between the first group of conductor patterns 81 and the second group of conductor patterns 81 while keeping the two groups of conductor patterns 81 at the same potential. In the case of executing (M-1) times while changing the combination of the conductor patterns 81 set as the second group, the first conductor pattern 81 in the first measurement process. The other conductor pattern 81 excluding the conductor pattern 81 as the first group is the second group, and belongs to the second group in the immediately preceding measurement process in the second to Nth measurement processes (N is an integer less than M). One of the conductor patterns 81 is excluded from the second group and added to the first group. In the (N + 1) th to (M−1) th measurement processes, the first group is the earliest in the immediately preceding measurement process. Is excluded from the first and second groups, and one of the conductor patterns 81 belonging to the second group in the immediately preceding measurement process is added to the first group. In this case, the value of N corresponds to the number of processes per conductor pattern 81 (the number of “●” shown in FIGS. 3 to 5). Therefore, for example, as shown in FIG. 3, N is defined as 2 in the first inspection condition, and as shown in FIG. 4, N is defined as 3 in the second inspection condition, as shown in FIG. In the third inspection condition, N is defined as 1. Also in such a configuration and method, the second inspection condition for performing the pass / fail inspection for the circuit board 80 based on the physical quantity generated when the inspection signal Ve is supplied to the conductor pattern 81 of the circuit board 80 is further set. It is possible to make the reference higher than the first inspection condition reliably and easily, and the third inspection condition when performing the pass / fail inspection for the circuit board 80 based on the physical quantity is more reliably and easily performed. Can be a lower standard.

  In addition, when the defect rate of the circuit board 80 at the intermediate time is equal to or higher than the first reference rate R1, the first process for changing the inspection condition in the pass / fail inspection after the intermediate time to the second inspection condition, and the circuit board 80 at the intermediate time The configuration and method for executing both the second process of changing the inspection condition in the pass / fail inspection after the intermediate time point to the third inspection condition when the defect rate is equal to or less than the second reference rate R2 have been described above. A configuration and a method for executing only one of the two processes may be employed.

  Further, when the changed inspection condition (second inspection condition or third inspection condition) changed at the intermediate time point is set as a new first inspection condition, the pass / fail inspection for a part of the circuit boards 80 is thereafter completed (new intermediate condition). It is also possible to employ a configuration and method in which at least one of the first process and the second process is performed again at the time. According to this configuration and method, when the defect rate of the circuit board 80 changes after changing the inspection condition at the first intermediate point, the inspection condition can be changed again according to the change in the defect rate. The inspection accuracy can be further improved while further suppressing the decrease in inspection efficiency.

  Further, the configuration example in which the two probes 21 and 21 are brought into contact with the pair of conductor patterns 81 on the circuit board 80 has been described above. However, a configuration and method using a probe unit that includes a plurality of probes 21 and is configured in a jig shape. It can also be adopted.

DESCRIPTION OF SYMBOLS 1 Circuit board inspection apparatus 3 Voltage detection part 4 Current detection part 5 Discharge detection part 9 Control part 80 Circuit board 81 Conductor pattern R1 1st reference rate R2 2nd reference rate Ve Inspection signal

Claims (6)

An inspection unit that measures a physical quantity that accompanies the supply of an inspection signal to a conductor pattern on a circuit board and performs a quality test that inspects the quality of the circuit board based on the measured value under a predetermined first inspection condition. A circuit board inspection apparatus comprising:
The inspection unit performs the pass / fail inspection on the plurality of circuit boards of the same type, and the circuit at an intermediate point in time when the pass / fail inspection on some of the circuit boards is completed. A first process of changing an inspection condition in the pass / fail inspection after the intermediate time point to a second inspection condition having a higher standard than the first inspection condition when a substrate defect rate is equal to or higher than a first reference rate defined in advance; And when the defect rate of the circuit board at the intermediate time is equal to or lower than a second reference rate defined in advance to a value lower than the first reference rate, the inspection condition in the pass / fail inspection after the intermediate time is set to the first inspection. A circuit board inspection apparatus that performs at least one of a second process for changing to a third inspection condition whose standard is lower than the condition. As the first inspection condition, the second inspection condition, and the third inspection condition, a supply time of the inspection signal supplied to the conductor pattern is defined,
The supply time in the second inspection condition is defined as a time longer than the supply time in the first inspection condition, and the supply time in the third inspection condition is shorter than the supply time in the first inspection condition The circuit board inspection apparatus according to claim 1, as defined in claim 1. As the first inspection condition, the second inspection condition, and the third inspection condition, a signal level of the inspection signal supplied to the conductor pattern is defined,
The signal level in the second inspection condition is defined to be higher than the signal level in the first inspection condition, and the signal level in the third inspection condition is lower than the signal level in the first inspection condition The circuit board inspection apparatus according to claim 1 or 2, as defined in claim 1. As the first inspection condition, the second inspection condition, and the third inspection condition, the number of times that the process of supplying the inspection signal and measuring the physical quantity is executed per one conductor pattern is defined,
The number of times in the second inspection condition is defined to be greater than the number of times in the first inspection condition, and the number of times in the third inspection condition is defined to be less than the number of times in the first inspection condition. The circuit board inspection apparatus according to claim 1.   5. The circuit board inspection apparatus according to claim 1, wherein the inspection unit performs at least one of the first process and the second process using the changed inspection condition as the new first inspection condition. 6. . A circuit board that measures a physical quantity that accompanies the supply of an inspection signal to a conductor pattern of a circuit board and performs a quality test for inspecting the quality of the circuit board based on the measured value under a predetermined first inspection condition An inspection method,
When performing the pass / fail inspection on a plurality of the circuit boards of the same type, a defect rate of the circuit board at an intermediate point in time when the pass / fail inspection on a part of the circuit boards is completed. A first process for changing an inspection condition in the pass / fail inspection after the intermediate time point to a second inspection condition having a higher standard than the first inspection condition when the first reference rate is equal to or higher than a first reference rate defined in advance; When the defect rate of the circuit board is equal to or lower than a second reference rate defined in advance to a value lower than the first reference rate, the inspection condition in the pass / fail inspection after the intermediate time point is set to be higher than the first inspection condition. A circuit board inspection method for performing at least one of a second process for changing to a low third inspection condition.

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