Patent ID: 6026176
Filing Date: 2000-02-15
Classification: G01N,G06T

Abstract:
A method of inspecting an image to locate a ball grid array surface-mounted device that is characterized by an array of similar surface features the method comprising:A. inspecting the image to find said surface features and to determine their observed locations,B. comparing expected locations of the surface features with the observed locations to identify any surface features that are apparently missing, wherein the comparing step comprisesdetermining, from the observed locations of the surface features found in the inspecting step, a convex hull and its angle,determining, from the convex hull and its angle, a grid of expected locations of the surface features,C. reinspecting the image in a vicinity of an apparently missing surface feature to find that apparently missing surface feature and to determine its observed location, andD. determining, from the observed locations of the surface features found in the inspecting and reinspecting steps, any of a position and an angle of the ball grid array surface mounted device.