Apparatus and method for testing coplanarity of semiconductor components

摘要

A method and apparatus for measuring the alignment of leads along the perimeter of an integrated circuit surface mount device (SMD). The device is placed so that a first lead is within the path of a beam of light emitted from a light source. The light source is moved around the perimeter of the device so that the beam of light contacts all of the leads of the device. The angle of reflection of the beam of light off of each of the leads is detected. From this angle, the alignment of the leads is determined by first calculating a seating plane and then calculating the variation of each lead from the seating plane.