METHOD AND DEVICE FOR CHECKING PATTERN DEFECT

摘要

PURPOSE:To check pattern defects with high accuracy and in a small rechecking frequency by securing an exclusive OR to perform the comparison between the comparison mask pattern data and the check pattern data. CONSTITUTION:The CAD data is read via a magnetic tape device 10 and stored in a bit map memory 9a. Then the center coordinates of each land L of a printed board having the low defect recognizing accuracy and the diameter corresponding to the error allowable value are inputted for the CAD data via a CRT 12. Thus the allowance data is obtained and stored in a bit map memory 9b. Then a comparison mask pattern data generating part 4c reads out the master picture data stored in both memories 9a and 9b and the error allowance data in sequence to secure an exclusive OR. Thus the comparison pattern data is obtained and stored in a bit map memory 9c. A contour data forming part 4d reads out the data in sequence out of the memory 9c for production of the contour data. This data is stored in a bit map memory 9d. Then the exclusive ORs 31 and 32 are secured between the check pattern data received from a CCD camera 3 and the data received from both memories 9c and 9d. Thus the defect data is outputted.