Patent Document ID: 5402505
Application ID: 08138791
Patent Status: 1

Claim One:
1. A method, using an imaging system, for automatically measuring the coplanarity of lead ends of a surface-mounted semiconductor device; said device having at least two sides and a plurality of leads along each of said device sides; and said method comprising the steps of: providing a rotatable platform having a planar top surface and at least two sides; said platform sides respectively corresponding to said device at least two sides; and each platform side having a face with features respectively defining x- and y-axis directions; providing a reference member fixed in spaced position relative to said platform; said member having a feature defining a straight line which is parallel to said plane of said platform top surface, and having at least a feature of known y-axis direction linear dimensional extent; providing an imaging system, including a camera having a field of view simultaneously encompassing said rotatable platform and said reference member; mounting said device on said top surface of said platform; rotating said platform to successively present each side of said mounted device toward said camera so that, for each device side presented, said camera field of view simultaneously encompasses said presented device side, said platform side corresponding to said presented device side, and said reference member; for each presented device side, grabbing an image of said camera field of view in pixel image form; for each grabbed image, locating positions of said lead ends relative to positioning of said straight line; from a pixel form image of said reference member known linear dimensional extent feature, identifying a scale factor relating pixels to linear dimensional measurement units; and using said position locations and said scale factor for the grabbed images, determining the coplanarity of said lead ends of said sides.