Abstract: A three dimensional inspection apparatus for ball array devices, where the ball array device is positioned in a fixed optical system. An illumination apparatus is positioned for illuminating the ball array device. A first camera is disposed in a fixed focus position relative to the ball array device for taking a first image of the ball array device to obtain a characteristic circular doughnut shape image from a ball. A second camera is disposed in a fixed focus position relative to the ball array device for taking a second image of the ball array device to obtain a top surface image of the ball. A processor applies triangulation calculations on related measurements of the first image and the second image to calculate a three dimensional position of the ball with reference to a pre-calculated calibration plane.

Abstract: A three dimensional inspection process for ball array devices. The ball array device is positioned in a fixed optical system. The ball array device is illuminated and a first image of the ball array device is taken 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 a ball. A second image of the ball array device is taken with a second camera disposed in a fixed focus position relative to the ball array device to obtain a top surface image of the ball. The first image and the second image are processed using a triangulation method to calculate a three dimensional position of the ball with reference to a pre-calculated calibration plane.

Abstract: A method for part placement of a semiconductor chip for inspection where the semiconductor chip has a plurality of leads defining a seating plane and a body having a top. The method includes the steps of placing the body on a platform in an up position where the plurality of leads are suspended and probing the top of the body. Next measuring the position of the top of the body with reference to a predetermined coordinate system is done. Then the part is moved until the part is suspended on the plurality of leads on a reference plane. The top of the body is then probed for a second time, and the second position of the top of the body is measured with reference to the predetermined coordinate system. The thickness of the part is then determined as the distance between the top of the part and its seating plane.