Exterior view inspecting apparatus for circuit board

摘要

The exterior view inspecting apparatus for circuit board of the invention including a sensor unit for emitting a laser beam to an object to be inspected, and detecting the displacement of the object by focusing the reflected light on a photoelectric transducer by using a receiving lens; an optical path converter unit for refracting the optical path of the laser beam; a sensor head unit incorporating the sensor unit and optical path converter unit; a control unit for moving the sensor head unit along a specified scanning route; a correction unit for correcting the displacement data of the object to be inspected as detected by the sensor unit, and a judging unit for judging the existence and position of an electronic component on a circuit board from the corrected displacement data. The optical path converter unit includes a flat sheet glass inclined relative to the optical path of the laser beam, rotating about the axial center parallel to the optical path. By this optical path converter unit, the optical path of the laser beam is refracted so that the laser beam scans the circuit board drawing a small circular trace. As the trace draws a small circle, the trace detects the end portion of the electronic component on the circuit board multiple times. Consequently, the existence and position of the electronic component on the circuit board can be detected accurately.