WO2002086520A1

WO2002086520A1 - Inspection apparatus and inspection method

Info

Publication number: WO2002086520A1
Application number: PCT/JP2002/003877
Authority: WO
Inventors: Shuji Yamaoka; Shogo Ishioka
Original assignee: Oht Inc.
Priority date: 2001-04-19
Filing date: 2002-04-18
Publication date: 2002-10-31
Also published as: TWI266885B

Abstract

An inspection apparatus and inspection method capable of high-speed inspection of every kind of circuit wiring. An inspection apparatus (1) supplies an inspection signal from probes (21a to e) to one end of circuit wiring (101a to e) and reads a voltage change of the other end of the circuit wiring (101a to e) by sensors (22a to e), so that signals from the sensors (22) are amplified by amplifiers (23a to e) and peak hold circuits (24a to e) extract and hold the maximum signal values amplified. After this, the peak value (maximum value) for each of the circuit wiring held by the peak hold circuits (24a to e) is selected via a selector (25) and sent to an A/D conversion circuit (26), so that it is converted into a corresponding digital value which is fetched by a computer (27). The computer (27) detects malfunction of the circuit wiring (101a to e) in accordance with the output value from the A/D conversion circuit (26).

Description

Description ^: Inspection device and inspection method

The present invention relates to an inspection device and an inspection method for inspecting circuit wiring. Background art

In the manufacture of circuit boards, it is necessary to test whether or not the circuit wiring is broken after providing circuit wiring on the board. As one of the board inspection methods, a method of inspecting a circuit wiring by applying an electric signal to one end of the circuit wiring and measuring an electrical change of the other end has been conventionally known. Kaihei 10—2 393 771, JP-A-10—23939 272). The conventional inspection method has been performed by an inspection apparatus having a configuration as shown in FIG. In FIG. 6, the inspection apparatus selects a probe 61 that contacts one end of the circuit wiring 101 on the circuit board 100 and a probe to which a voltage is applied from a plurality of probes 61. A switching circuit 62, a sensor 63 for detecting a voltage applied from the other end of the circuit wiring 101, an amplifier 64 for amplifying an electric signal from the sensor 63, and an amplifier 64 A peak hold circuit 65 that extracts the maximum value of the electric signal, and a computer 66 that detects a fault in the circuit wiring based on the extracted maximum value are provided.The computer 6 also controls the switching circuit 62 to Apply voltage to probe 61 in sequence. The voltage change on the circuit wiring 101 caused by the voltage supplied to the circuit wiring 101 from the probe 6 1 After detection by 3 and amplification by the amplifier 64, the maximum value is extracted by the peak hold circuit 65 and input to the computer 66. The computer 66 detects which circuit wiring has a problem from the voltage waveform input from the peak hold circuit 65.

However, in the above-described conventional method, only one circuit wiring can be inspected by one voltage application, so that the more circuit wirings, the longer the inspection time.

In addition, since the sensor, amplifier, and peak hold circuit are single, it was not possible to detect which branch had a problem in circuit wiring that branches off in the middle.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an inspection apparatus and an inspection method capable of performing high-speed inspection on any circuit wiring. Disclosure of the invention

In order to achieve the above object, an apparatus according to the present invention has, for example, the following configuration. That is, an inspection device for inspecting a circuit wiring, comprising: a supply unit capable of supplying an inspection signal from near one end of the circuit wiring to be inspected; and a supply unit from near the other end of the inspection target circuit wiring. Detecting means for detecting the detected test signal, and test result determining means for determining a test result from the test signal detected by the detecting means, wherein the test result determining means is detected by the detecting means. A maximum value extraction unit for extracting a maximum value of the inspection signal, wherein the maximum value extracted by the maximum value extraction unit is used as an inspection result. , Wherein the detecting means and the maximum value extracting means are provided.

Then, for example, the detection unit performs the inspection without contacting the vicinity of the other end. It is characterized in that a signal can be detected.

Further, for example, the maximum value extracting means is a peak hold circuit, and holds a peak value extracted until the inspection signal supplied by the supplying means is read out.

Further, for example, when there are a plurality of the one end and the other end, the supply means can apply a test signal to a plurality of the one ends at the same time, and the detection means detects a plurality of the other ends. It is characterized in that inspection signals can be simultaneously detected from each.

In addition, there is provided an inspection apparatus for inspecting a circuit wiring, comprising: a supply unit capable of supplying a pulse signal as an inspection signal near one end of the inspection target circuit wiring; A detection means capable of detecting a signal; comparing the detection result of the detection means before the supply of the test signal with the detection result of the detection means after the supply of the test signal; and comparing the comparison result with a normal circuit wiring. Determining means for comparing the detection result with the circuit wiring to be inspected for quality.

Further, for example, the apparatus further comprises an inspection result determination unit that collects the inspection signal from the detection unit a plurality of times and uses the average of the collected signals as a detection result, wherein the determination unit detects the detection result by the inspection result determination unit. It is characterized by processing as a means detection result.

In addition, there is provided an inspection device for inspecting a circuit wiring, comprising: a supply unit capable of supplying an inspection signal near one end of the circuit wiring to be inspected; and detecting the inspection signal from near the other end of the circuit wiring to be inspected. A possible detection means, and an inspection result determination means for collecting the inspection signals from the detection means a plurality of times and using the average of the collected signals as a detection result.

Then, for example, the inspection result determination means removes the maximum value and the minimum value of the plurality of inspection signals detected by the detection means and obtains the average value of the remaining detection results to perform the inspection. It is characterized by the inspection method as a result.

Also, for example, the inspection result determination unit includes an A / D conversion unit that converts a detection result of the detection unit into a corresponding digital signal, and calculates an average of digital values converted by the A / D conversion unit as a detection result. The A / D conversion unit can hold a plurality of A / D-converted detection values of the detection unit when the detection signal is detected by the detection unit, and hold the detection values after the detection process is completed. And outputting the converted result.

A method for inspecting a circuit wiring, the method comprising: supplying a pulse signal as an inspection signal near one end of the circuit wiring to be inspected; and supplying a pulse signal as an inspection signal near the other end of the circuit wiring to be inspected. A detection step of detecting the test signal supplied in the supply step; a detection result in the detection step before the supply of the test signal; and a detection result in the detection step after the supply of the test signal. And an inspection result determining step of determining whether the inspection target circuit wiring is good or not by comparing the detection result with the detection result in the case of a normal circuit wiring.

For example, in the inspection result determination step, the inspection method is characterized in that an inspection signal is detected a plurality of times in the detection step, and an average of the plurality of detection results is used as the detection result.

Further, there is provided an inspection method in an inspection device for inspecting a circuit wiring, comprising: a supply step of supplying an inspection signal near one end of the inspection target circuit wiring; A test step of detecting the test signal supplied in the step, and a test result determining step of causing the test signal to be detected a plurality of times in the detection step, and using an average of the detection results of the plurality of times as a detection result. The method is characterized by:

Then, for example, the inspection result determination step removes the maximum value and the minimum value of the plurality of inspection signals detected in the detection step, obtains the average value of the remaining detection results, and performs the inspection. It is characterized by the result. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing a schematic configuration of an inspection device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a circuit board to be inspected according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a schematic hardware configuration of a computer of the inspection apparatus according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a state in which an inspection device according to the first embodiment of the present invention inspects a circuit wiring having a branch.

FIG. 5 is a diagram showing a schematic configuration of an inspection device according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram of a conventional inspection device.

FIG. 7 is a block diagram for explaining a configuration of an inspection apparatus according to a third embodiment of the present invention. .

FIG. 8 is a diagram for explaining a configuration of an inspection apparatus according to a fourth embodiment of the present invention.

FIG. 9 is a timing chart for explaining sensor detection control according to the fifth embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be illustratively described in detail with reference to the drawings. However, the relative arrangements, numerical values, and the like of the components described in the embodiments are not intended to limit the scope of the present invention thereto unless otherwise specified. (First Embodiment)

As a first embodiment of the present invention, as shown in FIG. 2, an inspection apparatus for inspecting unbranched circuit wirings 101 a to e printed on a circuit board 100 will be described.

FIG. 1 is a schematic diagram of an inspection device 20 for inspecting circuit wirings 101 a to e on a circuit board 100.

The inspection device 1 includes a probe 21 a to e for supplying an inspection signal to one end of the circuit wiring 101 a to e, and a sensor 2 for reading a voltage change at the other end of the circuit wiring 101 a to e. 2a to e, amplifiers 23a to e for amplifying the signal output from the sensor 22, and peak hold circuits 24a to e for extracting the maximum value of the signal amplified by the amplifiers 23a to e And a peak hold circuit 24, a selector 25 for selecting an output value from the a-e, an A / D conversion circuit 26 for converting the output value selected from the selector 25 to a digital value, and an A / D conversion. And a computer 27 for detecting a defect in the circuit wiring 101 a to e based on an output value from the circuit 26.

The computer 27 may be a specially designed computer or a general-purpose personal computer, and may include an amplifier 23, a peak hold circuit 24, a selector 25, and an A / D conversion circuit 2. 6 may be incorporated into computer 27.

The computer 27 supplies the probe 21 with an electric signal to be applied to the circuit wiring 101. Further, a selection signal for selecting a peak hold circuit for extracting a signal is supplied to the selector 25.

The applied electric signal may be a current or a voltage, and may have any waveform such as a sine wave, a rectangular wave, and a pulse wave. Here, a voltage pulse is used. Because the signal polarity can be limited, the circuit can be designed with the current direction in the sensor limited to one direction, which simplifies the circuit design. You.

Probes 21 a to e have their tips in contact with one end of circuit wiring 101 a to e on circuit board 100, respectively. Supply voltage at the same time.

As a result, the voltages on the circuit wires 101 a to e change, and the changes are read by the sensors 22 a to e. The sensors 22 a to e are metal plates connected to the circuit wirings 101 a to e of the circuit board 100, and detect the voltage on the circuit wiring 101.

The voltage applied to the circuit wiring 101 a to e is very small as in actual operation, and the voltage generated in the sensors 22 a to e is also very small. Amplify by ~ e and hold the maximum value by peak hold circuit 24a ~ e.

The selector 25 selects a peak hold circuit to be connected to the A / D conversion circuit 26 among the peak hold circuits 24 a to e. The selection is performed based on the control signal supplied from the computer 27 so that the maximum value is sequentially taken out one by one from the plurality of peak hold circuits 24a to 24e.

The maximum value output from the peak hold circuit is converted into a corresponding digital signal by the A / D conversion circuit 26 and input to the computer 27. The computer 27 checks whether the input digital signal has a normal value. For example, comparing with a predetermined threshold value, if the value is larger than the threshold value, it is determined that there is no disconnection in the circuit wiring, and if the value is smaller than the threshold value, it is determined that there is a disconnection in the corresponding circuit wiring. to decide.

Note that the sensor 22 may be arranged in a non-contact manner at a position facing the circuit wiring 101. In this case, the distance between the sensor 22 and the circuit wiring 101 is desirably 0.05 mm or less. Further, the insulating material may be closely attached with a dielectric insulating material interposed therebetween. With this configuration, the circuit wiring 101 and the electrostatic coupling And the pulse-like voltage change of the circuit wiring 101 can be detected from the sensor.

In addition, in the circuit board 100 of FIG. 2, it is assumed that the circuit wiring 101 is provided only on one side, but a circuit board having the circuit wiring 101 provided on both sides is assumed. Can be inspected. In this case, it is only necessary to arrange the circuit board in a sandwich manner using two sets of the sensors 22 in the upper and lower directions.

Next, a detailed configuration example of the computer 27 will be described with reference to FIG. FIG. 3 is a block diagram showing a schematic hardware configuration of the computer 27.

In FIG. 3, reference numeral 211 denotes an arithmetic and control CPU for controlling the entire computer 27, and reference numeral 212 denotes a ROM for storing programs executed by the CPU 211, fixed values, and the like.

Reference numeral 214 denotes a RAM for temporary storage, which includes a program load area for storing a program to be loaded, a storage area for a digital signal received from the A / D conversion circuit 26, and the like.

Reference numeral 215 denotes a hard disk as an external storage device. Reference numeral 2166 denotes a CD-ROM drive as a removable storage medium reading device.

Reference numeral 217 denotes an input / output interface, which is a keypad as an input device, a mouse 219, a probe 21, a probe 21, a selector 25, an A through the input / output interface 217. It controls the interface with the / D conversion circuit 26 and exchanges various signals.

An inspection control execution program including a selector control program is stored in the HD 215, and is executed by, for example, being slid into a program storable area of the RAM 224. Also, image data (CAD data) indicating the shape of the circuit wiring in the design is stored in the HD215. The selector control program and the image data showing the shape of the circuit wiring in the design can be installed by reading the CD-ROM with the CD-ROM drive 216, but not for other devices such as FD and DVD. May be read from a medium such as the Internet, or downloaded via a network.

As described above, according to the present embodiment, a peak hold circuit is provided for each circuit wiring, so that simultaneous measurement of sensors in the same circuit group can be performed. Can be achieved.

Also, as shown in Fig. 4, the circuit wiring branched in the middle, for example, by providing sensors 22a to e, amplifiers 23a to e, and peak hold circuits 24a to e for each branch. It is possible to detect which branch has a defect.

In the present embodiment described above, the voltage of the circuit wiring is detected. However, the amount and shape of the electromagnetic wave radiated from the circuit wiring may be detected. In this case, if the predetermined amount and shape of the electromagnetic wave can be detected, it is determined that the circuit wiring is normally continued. If an amount smaller than the predetermined amount and the shape of the electromagnetic wave and a different shape are detected, it is determined that the middle of the circuit wiring is distant or missing.

Furthermore, in the present embodiment described above, the probe is brought into contact with the vicinity of the end of the circuit wiring. However, the inspection signal may be supplied from the starting point of the circuit wiring using a non-contact terminal.

(Second embodiment)

Next, an inspection apparatus as a second embodiment of the present invention will be described with reference to FIG.

The inspection apparatus of the second embodiment differs from the first embodiment in that A / D conversion circuits 26 a to 26 e are provided for each of the peak hold circuits 24 a to e. different. In the case of the configuration of the second embodiment, a plurality of data Since digital signals can be input to the computer 27 in parallel, the selector 25 is not required.

The other components are the same as those in the first embodiment, and thus the same components are denoted by the same reference numerals and description thereof will be omitted.

In the drawing, the wiring between the A / D conversion circuits 26a to 26e and the computer 27 is shown by one line, but in actuality, each A / D conversion circuit 26a to The book wiring is connected to the computer 27.

According to the second embodiment, since the selector can be eliminated, control such as signal switching as in the first embodiment is not required, and productivity can be improved.

(Third Embodiment)

In the above explanation, the detection signal from the sensor is sent to the peak hold circuit, where the peak value is held, and the hold value is A / D converted by the A / D converter 26 and sent to the computer 27. I was However, the present invention is not limited to the above example. If there is sufficient processing capacity on the computer side, the detection signal from the sensor is directly A / D converted by the A / D converter 26, and A / D conversion is performed. The digital signal from the / D converter 26 may be directly input to a computer and the state of the circuit wiring may be inspected by signal processing. That is, in the above-described embodiment, if a noise component is superimposed from the sensor and sent to the peak hold circuit, the noise component may be detected as an applied voltage. Therefore, in the third embodiment, in order to eliminate the influence even when the noise component is superimposed and to be able to reliably detect the applied voltage from the circuit wiring, for example, a diagram explained below. It has 7 configurations. FIG. 7 is a block diagram for explaining the configuration of the inspection device according to the third embodiment of the present invention. 7, the same components as those in FIG. 1 are denoted by the same reference numerals, and different components will be described. In the third embodiment shown in FIG. 5, the peak hold circuit is omitted as compared with the first embodiment shown in FIG. 1, and the A / D converter 26 and the computer 27 are used instead. Monitor the detection level from the circuit wiring.

In the third embodiment, the 8/0 converter 26 holds the A / D conversion result by a predetermined amount, and converts the digital conversion value into a time series according to the readout control from the computer 27. Output to

The inspection control program is stored in the computer 27, the program is executed, the voltage application process described below is sequentially executed for each wiring pattern, and the A / D converter 26 holds the inspection result.

First, an operation enable signal for the A / D converter 26 is output, and the 8/0 converter 26 is energized. Thus, every time a conversion instruction signal is input thereafter, the input analog signal at that time can be converted into a corresponding digital signal and held.

Time when the operation of the A / D converter 26 stabilizes, for example, after a lapse of 30 s, the detection results from all wiring patterns before applying the test voltage to the probes 21 a to e Is supplied to the A / D converter 26, and the A / D converter 26 performs A / D conversion a predetermined number of times, for example, several times (for example, 5 times) at intervals of 2 / is. The detection result from e is collected multiple times and the digital value corresponding to the analog voltage output value (low level value) from each sensor 22a to e is held.

In this process, the A / D converter 2 is switched by switching the selector 25 for each circuit wiring.

The signal from the sensor for each circuit wiring is supplied to A / D conversion 6, and the conversion result is recorded in chronological order.

After the A / D conversion processing before the application of the inspection voltage is completed, the inspection voltage is applied to the probes 21a to 21e. When the test voltage is applied to the circuit wiring, a test voltage signal is detected by, for example, the sensors 22a to e after a predetermined delay time has elapsed. For this reason, the A / D converter 26 performs the A / D conversion a predetermined number of times, for example, several times after the time when the detection signals from the sensors 22 a to e stabilize, and the inspection signal for each circuit wiring. The converted digital value corresponding to the detection result is held.

The above control is performed for each circuit wiring pattern. When the application of the inspection signal to all the circuit wiring, the conversion of the sensor 22 a to e detection signals into digital signals by the A / D converter 26 and the storage of the converted values are completed, the A / D converter 26 Read the converted digital value for each wiring pattern from 6, extract the difference between the sensor detection value before voltage application and the sensor detection value after voltage application, and determine whether the applied voltage is detected by the sensor unit I do. ,

Specifically, in order to eliminate the effects of noise components even when they are superimposed, and to ensure that the applied voltage from the circuit wiring can be detected, the stored multiple inspection results are averaged to obtain a sensor. This is the detection result.

In order to further reduce the effect of noise, the largest value and the smallest value were removed from the converted values of several times, and the average value of the remaining converted values was calculated and calculated. The average value may be used as the sensor detection value at the timing. This can further reduce the influence of noise and the like. Then, the computer 27 detects a detection value before application of the inspection voltage and a detection value after application of the inspection voltage for each circuit wiring. Then, the two detected values are compared with the values detected from the reference work (standard wiring pattern). If the error is within a predetermined range, the circuit is judged to be normal circuit wiring. Judge as a broken wire.

In addition, when the test voltage is applied at a separate timing for each circuit wiring, and when the conversion value can be detected from the circuit wiring next to the test voltage application circuit wiring, the test voltage is applied adjacent to the circuit wiring. If a large conversion value is also detected from the sensor of the circuit wiring, it can be determined that the circuit wiring to which the test voltage has been applied is short-circuited to the adjacent circuit wiring that detected the high conversion value. As described above, according to the third embodiment, by actively using the computer 27, it is not necessary to use a peak hold circuit for detecting a high level value, and a plurality of high level values can be detected. The average value can be calculated by detecting the level value, and even if noise is superimposed on the circuit wiring, the effect can be minimized. Thus, a more reliable circuit wiring inspection is realized.

(Example of the fourth embodiment)

The control by the computer 27 described above is not limited to the example shown in FIG. 5, but can be similarly applied to the configuration shown in FIG. 5 of the above-described second embodiment. With reference to FIG. 8, a description will be given below, with reference to FIG. 8, of a configuration of an inspection apparatus in which the computer 27 is configured to be able to detect a high level value and a low level value in the configuration shown in FIG. 5, similarly to the third embodiment. FIG. 8 is a view for explaining the configuration of the inspection apparatus according to the fourth embodiment of the present invention.

In the fourth embodiment, the detected analog signals from the sensors 22 a to e are amplified by the respective amplifiers 23 a to e and sent to the A / D converters 26 a to e. Here, for example, first, an operation permission signal is output to each of the A / D converters 26a to 26e or only to a desired A / D converter, and the A / D converter is energized. As a result, the A / D converter to which the operation permission signal has been supplied thereafter can convert the input analog signal into a corresponding digital signal and hold it.

After the time when the operation of the A / D converter 26 stabilizes, for example, 30 / s, the detection result from the corresponding wiring pattern is applied before the test voltage is applied to the probes 21 a to e. A / D converter 26 A / D conversion by A to D and hold. As in the third embodiment, the A / D converters 26a to 26e perform A / D conversion a predetermined number of times, for example, several times (for example, five times) at intervals of 2S. 2 Corresponds to the analog voltage output value (low level value) from a to e Retain digital values.

After the A / D conversion processing before the application of the inspection voltage is completed, the inspection voltage is applied to the probes 21a to 21e. When the test voltage is applied to the circuit wiring, the test voltage signals are detected by, for example, the sensors 22 a to e after a predetermined delay time has elapsed.

Therefore, after a lapse of time when the detection signals from the sensors 22 a to e elapse, the A / D converters 26 a to 26 e perform A / D conversion a predetermined number of times, for example, several times. The converted digital value corresponding to the test signal detection result is held.

After that, when the conversion of the sensor 22 a to e detection signals into digital signals in the A / D converters 26 a to e and the storage of the converted values are completed, wiring from the A / D converters 26 a to e is completed. The conversion digital value for each pattern is read, and the difference between the sensor detection value before voltage application and the sensor detection value after voltage application is extracted, and it is determined whether or not the applied voltage is detected by the sensor unit. Of course, the expenditure method of the detection result can adopt the same method as in the third embodiment described above.

As described above, according to the fourth embodiment, the reading control from the A / D converters 26a to 26e can be further facilitated, and the A / D converters 26a to It is possible to take out the detection results of the sensors 22a to 22e of each circuit wiring only by reading them out in order.

(Fifth Embodiment)

In the above description, the case where a plurality of circuit wirings are inspected at the same time has been described as an example. However, the sensor output values when no inspection signal is applied and the sensor output values when the inspection signal is applied in the third and fourth embodiments are described. Value determination control can reduce the effects of noise components, and can provide highly reliable inspection results. The control for determining the sensor output value is shown in Figs. 1 to 5 or Figs. 7 and 8. The present invention is not limited to the case where the present invention is applied to an inspection apparatus, and also includes a case where the sensor is electrically connected to the circuit wiring and a case where the sensor and the circuit wiring are configured in a non-contact manner by electrostatic coupling. It can be applied to the control of determining the output value from a sensor that is electrostatically coupled to multiple circuit wirings. In this case as well, the effect of noise is reduced and a highly reliable inspection result is obtained. Obtainable.

In this case, for example, a pulse signal may be used as the inspection signal. A fifth embodiment according to the present invention in which a sensor and a circuit wiring are formed by non-contact electrostatic coupling will be described below also with reference to FIG. FIG. 9 is a timing chart for explaining the sensor 22 a to e detection control according to the fifth embodiment. Note that the configuration of the above-described embodiment can be applied to the configuration of another inspection apparatus. Hereinafter, portions different from the above-described embodiment will be described.

Also in the fifth embodiment, the inspection control program is stored in the computer 27 and the program is executed. In the case of the configuration shown in FIG. 7, the selector 25 is switched for each circuit wiring, and the A / A The conversion result for each circuit wiring is recorded in chronological order in the D converter 26, and after the control for all the circuit wirings is completed, the following read control is performed.

First, the operation permission signal of the A / D converter 26 shown in (A) of FIG. 9 is output, and the A / D converter 26 is energized to be controlled to an operable state. Thus, each time a conversion instruction signal is input thereafter, the input analog signal at that time can be converted into a corresponding digital signal and held.

After output of the A / D converter 26 operation enable signal After the time when the operation of the A / D converter 26 is stable and the level of the sensor detection signal is stable (for example, 30 s time) ( (After the LOW time range has elapsed.) The A / D converter 26 performs A / D conversion a predetermined number of times, for example, several times (for example, five times) at intervals of 2 / s, and holds each converted digital value. This LOW time is, for example, The inspection result from the wiring should be checked, and it should be decided in consideration of the inspection result.

The analog signals detected by the sensors 22a to 22e have waveforms shown in (C), and the A / D conversion timing (averaging range) is shown by an ellipse in FIG.

After the A / D conversion processing is completed, the inspection pulse signals are applied to the probes 21a to 21e at the timing shown in (B). When the inspection pulse signal is applied to the circuit wiring, the waveform shown in (C) is detected by, for example, the sensors 22a to e after a predetermined delay time has elapsed.

For this reason, after the time when the rate of change of the detection signal waveform from the sensors 22 a to e stabilizes after application of the inspection pal visual signal (for example, 100 ^ s), (after the High time range has elapsed) ) Have the A / D converter 26 perform A / D conversion a predetermined number of times, for example, several times, and hold each converted digital value. The averaging range is also indicated by an ellipse.

This High time range is examined, for example, by examining inspection results from multiple reference circuit wirings, inspecting a time zone in which the rate of change in sensor output is small, and changing while the detected waveform value of the inspection signal is at or above a certain level. It is sufficient to determine the time period when the rate is low.

Note that the low time range or the high time range is not fixedly determined as described above, but may be changed by the operator for each examination. In this case, it is desirable to perform an inspection on the reference circuit wiring and determine a threshold value for determining pass / fail.

As described above, a more reliable inspection result can be obtained by applying the inspection result determination processing to the detection result from the sensor that is not in contact with the circuit wiring.

(Another embodiment example)

The above explanation describes an example in which sensors are arranged at each circuit wiring end. As described above, the control for calculating the low-level value and the high-level value in the third and fourth embodiments can suppress the influence of noise and the like even if it is used independently for another inspection apparatus. High test results can be obtained.

Therefore, for example, it is necessary to determine the sensor detection value by performing the calculation control of the low level value and the high level value of the third and fourth embodiments on the sensor output of the inspection apparatus having the configuration shown in FIG. As a result, highly reliable inspection results can be obtained. In this way, a predetermined amount of conversion value is held in the A / D converter, and after the control of the application of the inspection voltage to the circuit wiring is completed, the conversion result can be read out at once, and can be used for computer processing. Since the inspection results can be calculated when there is enough time, the performance of the computer can be kept low and an inexpensive inspection device can be provided. Industrial applicability

As described above, according to the present invention, it is possible to provide an inspection apparatus and an inspection method which are highly reliable for all circuit wirings and are capable of high-speed inspection.

Claims

The scope of the claims

1. An inspection device for inspecting circuit wiring,

Supply means for supplying an inspection signal from near one end of the circuit wiring to be inspected;

Detecting means for detecting the test signal supplied by the supply means from near the other end of the circuit wiring to be tested;

Inspection result determination means for determining an inspection result from the inspection signal detected by the detection means,

Has,

The inspection result determination means includes maximum value extraction means for extracting a maximum value of the inspection signal detected by the detection means, and the maximum value extracted by the maximum value extraction means is used as an inspection result,

When there is a plurality of the other end,

An inspection apparatus, wherein the detection means and the maximum value extracting means are provided for each of the other ends.

2. The inspection apparatus according to claim 1, wherein the detection means is capable of detecting the inspection signal without contacting the vicinity of the other end.

3. Amplifying means for amplifying the test signal detected between the detecting means and the maximum value extracting means,

3. The detection device according to claim 1, wherein the amplification unit is provided for each of the detection units.

4. The maximum value extracting means is a peak hold circuit, and holds a peak value extracted until the inspection signal supplied by the supplying means is read out. The inspection device according to item 1.

5. Simultaneously input electric signals output from the plurality of maximum value extracting means 5. The inspection apparatus according to claim 1, further comprising an inspection unit that inspects the circuit wiring from the electric signal.

6. When there are a plurality of the one end and the other end, the supply means can apply a test signal to the plurality of the one ends at the same time, and the detecting means is provided for each of the plurality of the other ends. 6. The inspection apparatus according to claim 1, wherein an inspection signal can be simultaneously detected from the inspection signal.

7. An inspection method for inspecting circuit wiring on a circuit board,

A supply step of supplying an inspection signal near one end of the circuit wiring to be inspected, and a detection step of detecting an inspection signal supplied in the supply step from near the other end of the circuit wiring to be inspected;

An inspection result determination step of extracting the maximum value of the inspection signal detected in the detection step and obtaining an inspection result;

Has,

An inspection method characterized in that when there are a plurality of the other ends, the detection step and the inspection result determination step are performed simultaneously for each of the other ends.

8. An inspection device for inspecting circuit wiring,

Supply means capable of supplying a pulse signal as an inspection signal near one end of the circuit wiring to be inspected;

Detecting means capable of detecting the inspection signal from near the other end of the inspection target circuit wiring;

The detection result of the detection means before the supply of the inspection signal is compared with the detection result of the detection means after the supply of the inspection signal, and the comparison result is compared with the detection result in the case of a normal circuit wiring to determine whether the circuit wiring to be inspected is good An inspection apparatus characterized by having a judgment means for judging the condition.

9. Further, there is provided an inspection result determination unit that collects the inspection signal from the detection unit a plurality of times and sets an average of the collected signals as a detection result,

9. The inspection apparatus according to claim 8, wherein the determination unit processes a detection result by the inspection result determination unit as a detection result of the detection unit.

10. An inspection device for inspecting circuit wiring,

Supply means capable of supplying an inspection signal near one end of the circuit wiring to be inspected; detection means capable of detecting the inspection signal from near the other end of the circuit wiring to be inspected;

An inspection apparatus comprising: an inspection result determination unit that collects inspection signals from the detection unit a plurality of times and uses the average of the collected signals as a detection result.

11. The inspection result determining means removes a maximum value and a minimum value of a plurality of inspection signals detected by the detection means and obtains an average value of the remaining detection results to obtain a detection result. Or the inspection device according to claim 10.

12. The inspection result determination unit includes an A / D conversion unit that converts a detection result of the detection unit into a corresponding digital signal, and calculates an average of digital values converted by the A / D conversion unit as a detection result. To do

The A / D conversion unit can hold a plurality of detection values of the detection unit that have been A / D converted in the detection processing of the inspection signal by the detection unit, and can store the conversion result held after the detection processing. The inspection device according to any one of claims 9 to 11, wherein the inspection device outputs.

13. An inspection method in an inspection apparatus for inspecting circuit wiring, comprising: a supply step of supplying a pulse signal as an inspection signal to a vicinity of one end of a circuit wiring to be inspected;

A detection step of detecting an inspection signal supplied in the supply step from near the other end of the inspection target circuit wiring; The detection result in the detection step before the supply of the inspection signal is compared with the detection result in the detection step after the supply of the inspection signal, and the comparison result is compared with the detection result in the case of a normal circuit wiring for inspection. An inspection result determining step of determining the quality of the target circuit wiring.

14. The inspection according to claim 13, wherein in the inspection result determination step, detection of an inspection signal is performed a plurality of times by the detection step, and an average of the detection results of the plurality of times is used as a detection result. Method.

15. An inspection method in an inspection device for inspecting circuit wiring, comprising: a supply step of supplying an inspection signal near one end of the circuit wiring to be inspected; and a supply step from near the other end of the circuit wiring to be inspected. A detection step of detecting the test signal supplied at

An inspection result determination step of causing an inspection signal to be detected a plurality of times in the detection step, and determining an average of the plurality of detection results as a detection result.

16. The inspection result determination step removes the maximum value and the minimum value of the plurality of inspection signals detected in the detection step, obtains an average value of the remaining detection results, and sets the average as a detection result. The inspection method according to claim 4 or claim 15.

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