JPS6310779B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a circuit pattern defect inspection device for printed wiring boards.

Normally, defect inspection devices for circuit patterns, etc., except for devices with micropatterns such as photomasks, use markings to clearly identify defective locations in the pattern.

These general marking devices include spray markers, laser markings, ink jets, and the like, and because they can perform marking without contact, they are convenient for devices that inspect patterns while scanning a stage.

Some of these devices are very expensive and can be dangerous due to the use of high voltage power supplies. In particular, because there are holes such as through holes on the pattern of printed wiring boards, those that use ink such as conventional ink jets and spray markers
There were negative effects such as ink entering the through holes and staining the stage.

The purpose of the present invention is to eliminate the drawbacks of the above-mentioned prior art, to provide a printing machine equipped with a marking device that is inexpensive, takes safety into account, and can accurately mark defective positions without adversely affecting the surroundings. The present invention provides a circuit pattern defect inspection device for wiring boards.

That is, in order to achieve the above object, the present invention provides an apparatus for inspecting defects in a circuit pattern formed on a printed wiring board. An inspection device is provided that inspects defects in the circuit pattern formed on the printed wiring board by scanning the printed wiring board with an inspection head equipped with an imaging device that captures an image formed by the system, and A stamping rubber that is freely supported, contains ink, and can identify whether there is a defect; a drive device that presses the stamping rubber against a defective part on a printed circuit board; A marking device equipped with a release spring member is installed in the inspection head of the inspection device, the inspection device memorizes the position where a defect is detected, and the detection head detects a scanning line adjacent to the memorized defect position. A circuit pattern defect inspection apparatus for a printed wiring board is characterized in that it is provided with a control means for activating the drive device when the drive device reaches the position.

The present invention will be explained below based on embodiments shown in the drawings.

First, an embodiment of the circuit pattern defect inspection apparatus for printed wiring boards according to the present invention will be described in detail based on FIGS. 1 to 4.

In each figure, reference numeral 1 denotes a rotary roller around which a marking drive mechanism 7 is movable, and is rotatable by a bearing 6. 2 is an engraving head with an engraving rubber 3 attached to its tip, and an ink reservoir 14 is provided at the shaft center to hold the ink 1.
3, and a large number of rollers are installed at predetermined intervals along the circumferential direction of the hollow cylindrical rotating roller 1. Numeral 4 is a compression spring which always presses the stamping head 2 toward the center of the hollow cylinder so that the stamping rubber 3 does not come into contact with the printed wiring board 5 except during stamping. Reference numeral 8 is an electromagnetic solenoid, and by pushing the marking drive mechanism 7, the stamping rubber 3 is projected onto the outer periphery of the rotating roller 1, and as the rotating roller 1 rotates, it comes into contact with the printed wiring board 5 and is stamped. This is what I did. Reference numeral 9 denotes a rotating disk located on the rotating shaft of the hollow cylinder and provided with a large number of slits in synchronization with the marking head. 10
is a limit sensor for checking passage through a slit provided in the rotating disk 9. Reference numeral 11 denotes an air cylinder bored in the side of the detector body 12, and an inspection device (not shown) consisting of a pattern recognition device including an imaging device 16, which detects defects in the printed wiring board 5 using the detector body 12. ) (including when the stage scans in the thrust direction 32), the rotating roller 1 is inspected by the printed wiring board 5.
It is designed to move further away.

Next, the operation of this embodiment will be explained. First, the printed wiring board 5 is set on the stage 15, and then the marking device body is lowered by the air cylinder 11 so that the printed wiring board 5 and the rotating roller 1 come into contact with each other.
Next, the light source 20, the lens 19, the half mirror 18,
The stage 15 is scanned with respect to the detector body 12 equipped with an imaging device 16 formed from an imaging lens 17 and a TV camera, a linear image sensor, etc., and a reference detector body configured similarly to the detector body 12 described above. A stage (not shown) on which a reference conductor pattern is mounted is scanned with respect to a reference conductor pattern (not shown), and a video signal obtained from the imaging device 16 of the detector main body 12 is converted into a binary picture element. An inspection device (not shown) comprising a pattern recognition device converts the image signal and the video signal obtained from the imaging device of the reference detector main body into binary picture elements, and converts the binary picture element signal into an inspection device (not shown).
By doing so, pattern matching is performed by comparing with alignment errors and quantization errors removed, and it is inspected whether or not there is a defect in the conductor pattern of the printed wiring board 5.

The stage 15 is in the thrust direction 3 of the rotating roller 1.
2, the main body of the marking device is lifted upward by the operation of the air cylinder 11, so that the rotating roller 1 and the printed wiring board 5 do not come into contact with each other. As shown in FIG. 4, when the printed wiring board 5 is scanned in the scanning line direction 31 and a defect is found by the inspection device at point A in the figure, the location is memorized in that direction and the detector body When 12 reaches B in the figure, at least the rotating roller 1 is present at A in the figure, so marking is performed at this time. The marking is performed by the marking drive mechanism 7 by the electromagnetic solenoid 8.
As a result, the stamping heads 2, which are provided in a large number in the circumferential direction of the hollow cylinder, are all pushed out from the inside of the hollow cylinder to the outside, and the stamping rubber is pushed out from the outer periphery of the rotary roller 1, which is a hollow cylinder. sticks out. At this time, the marking rubber 3 that happens to rotate and comes into contact with the printed wiring board 5 marks the defective part. To release the marking, the limit sensor 10 detects the slit on the rotary disk 9 provided in synchronization with the marking head 2. At the same time, the electromagnetic solenoid 8 is turned off and the pressure from the inside by the marking drive mechanism 7 is eliminated, so that the marking head 2 is returned to the inside of the hollow cylinder by the compression spring 4, and the marking rubber 3 is pulled in from the outer periphery of the rotating roller 1. Furthermore, the slit provided in the rotating disk 9 is inserted into the limit sensor 10 after marking is completed. The timing at which the marking head comes onto the printed wiring board 5 is delayed slightly from that of the marking head 2 so that it can be detected. Furthermore, if the defective part is located on the pitch of the marking heads 2 arranged at equal intervals when the rotating roller 1 is unfolded, marking will be performed exactly on the defective part. If it is not on the pitch, it will be marked around the defect.
By narrowing the mounting interval of the marking heads 2, the positional error from the defective part to the marking part can be reduced.

Next, another embodiment of the printed wiring board circuit pattern defect inspection apparatus of the present invention will be described in detail with reference to FIGS. 5 and 6.

25 is a marking head, and the rotary roller 22 is supported by a shaft 24 and a bearing 23. The rotating roller 22 has an ink pad 21 and a pad holder 34.
Consists of. The marking head 25 is an electromagnetic solenoid 2.
8 and operates an electromagnetic solenoid 28 to slide on the inner surface of the guide 27.

Further, the guide 27 is provided with a notch so that a pin 26 for preventing rotation of the marking head 25 can be slid therein. Further, the tension spring 29 is a counterbalance for the marking head 25, and the adjustment screw 30
By turning , the strength of the tension spring 29 can be adjusted.

Next, the operation of this embodiment will be explained. First, after setting the printed wiring board 5 on the stage 15, the ink pad 21 is brought into contact with the printed wiring board 5 while the electromagnetic solenoid 28 is activated, and the marking head 25 is made vertical when the electromagnetic solenoid 28 is not activated. Adjust the strength of the tension spring 29 by turning the adjustment screw 30 upward. Next, the stage 15 is scanned to capture the image pickup device 1 of the detector body 12.
6 images the conductor pattern of the printed wiring board 5, and the video signal obtained from the imaging device 16 is taken by 2.
An inspection device (not shown) formed by a pattern recognition device performs value pixel processing and compares it with a binary pixelized signal of the reference conductor pattern to determine whether or not there is a defect in the conductive pattern. Inspect whether Since the ink pad 21 attached to the rotating roller 22 is impregnated with ink, the ink pad 21 and the printed wiring board 5 are normally in a non-contact state while the stage 15 is scanning. As shown in FIG. 4, when a defect is found at point A in the figure, the location is memorized in that direction, and when the detector main body 12 reaches point B in the figure, at least the rotating roller 22 is moved to point A in the figure.
Marking is done at this time. In reality, it is necessary to match the timing of the marking command to mark the defective part in accordance with the scanning speed of the stage. Marking is performed by activating the marking head 25 by the electromagnetic solenoid 28 and bringing the ink pad 21 attached to the rotating roller 22 into contact with the printed wiring board 5. During marking, as the printed wiring board 5 is scanned, the rotating roller 22 also rotates, so there is no fear of damaging the printed wiring board.

Further, by changing the supply time of the current given to the electromagnetic solenoid 28, the marking time can also be varied.

As explained above, according to the present invention, defective parts inspected by an inspection device can be displayed, that is, marked, on a printed circuit board having a large number of holes such as through holes, without ink entering the holes. , the effect can be achieved by a simple mechanism.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the circuit pattern defect inspection device for printed wiring boards of the present invention, FIG. 2 is a cross-sectional view showing a rotating roller of the marking device shown in FIG. 1, and FIG. FIG. 4 is an enlarged view showing the marking head of the marking device shown in the figure, FIG. 4 is a view showing the scanning path of the detector main body shown in FIG. 1, and FIG. FIG. 6 is a side sectional view of the marking device shown in FIG. 5. Explanation of symbols, 1... Rotating roller, 2... Engraving head, 3... Engraving rubber, 4... Compression spring, 5...
Printed wiring board, 6...bearing, 7...engraving drive mechanism, 8...electromagnetic solenoid, 9...rotating disk, 1
0...Limit sensor, 11...Air cylinder,
12...Detector body, 13...Ink, 14...
Ink reservoir, 15...scanning stage.

Claims (1)

[Claims] 1. In an apparatus for inspecting defects in a circuit pattern formed on a printed wiring board, an imaging optical system forms an image of the circuit pattern, and an image formed by the imaging optical system is imaged. An inspection device is provided for inspecting defects in a circuit pattern formed on a printed wiring board by scanning an inspection head equipped with an imaging device over a printed wiring board, the inspection device is rotatably supported, contains ink, and detects defects. The above-mentioned inspection of the stamping device includes a stamping rubber that can identify whether or not the stamping rubber is defective, a drive device that presses the stamping rubber against a defective part on a printed wiring board, and a spring member that releases the stamping rubber when the drive device is not operated. A control installed in an inspection head of the device, which stores a position where the inspection device detects a defect, and operates the drive device when the detection head reaches a position on a scanning line adjacent to the memorized defect position. 1. A circuit pattern defect inspection device for a printed wiring board, characterized in that a circuit pattern defect inspection device is provided.