Patent ID: 6278797
Filing Date: 2001-08-21
Classification: G01N,G01R

Abstract:
An apparatus for inspecting a circuit board with a plurality of lands disposed on one side of a circuit board substrate two-dimensionally, which side has at a place other than a place provided with the lands, an exposed portion constituting a background surface which is different in reflectance from a surface of each of the lands, the apparatus comprising a measurement system including:a beam source for supplying an inspection beam obliquely onto an inspection surface of the circuit board, said inspection surface including a surface region where the lands are disposed;a beam receiving section for receiving a reflected beam resulting from the inspection beam and reflected from the inspection surface, and producing a detection output which varies according to a reflected beam brightness and a reflected beam received position at said beam receiving section;beam scanning means for scanning the beam within the inspection surface two-dimensionally;height level information preparing means for preparing height level information which is information on height level at respective positions within the inspection surface, on the basis of the detection output indicative of the reflected beam received position at said beam receiving section; andreflected beam brightness information preparing means for preparing reflected beam brightness information which is information on reflected beam brightness at respective positions on the inspection surface on the basis of the detection output of said beam receiving section;the apparatus further comprising:land existing region fixing means for fixing, within the inspection surface, land existing regions where the respective lands exist, on the basis of the difference in the reflected beam brightness represented by the reflected beam brightness information, between the background surface and the surface of each of the lands;inspection information preparing means for preparing inspection information including land height level information which is information relating to surface height levels of the respective lands, on the basis of the height level information at respective positions within the land existing regions fixed by the land existing region fixing means; andinspection information output means for outputting the inspection information prepared by said inspection information preparing means;wherein said inspection information preparing means comprises land center calculating means for calculating a center of each of the land existing regions and determining the calculated center as a center of a corresponding one of the lands, and land arranging interval calculating means for calculating a land arranging interval on the basis of a distance between the centers of the lands calculated by said land center calculating means.