Patent ID: 7508974

Claim:
A method of manufacturing a ball array device, the method comprising: making a three dimensional inspection of a lead on the ball array device with the ball array device being positioned in a fixed optical system; and selecting the ball array device as a produced ball array device based upon the results of the three dimensional inspection; wherein the three dimensional inspection comprises: illuminating the ball array device; taking a first image of the ball array device with a first camera disposed in a fixed focus position relative to the ball array device to obtain a characteristic circular doughnut shape image from at least one ball; taking a second image of the ball array device with a second camera disposed in a fixed focus position relative to the ball array device to obtain a side view image of the at least one ball; and processing the first image and the second image using a triangulation method to calculate a three dimensional position of the at least one ball with reference to a pre-calculated calibration plane.