Abstract: An inspection method of determining the bonded status of a wire ball bonded to a pad of a semiconductor chip is provided. An image of the bonding position between the pad and the ball is taken by an image-taking unit for detection of an in focus height of the pad, in focus height of an upper surface of the bonded ball, an external diameter of the bonded ball, and a ball bonded point respectively while switching a color of a coaxial illuminating light depending on the specific position for the inspection. Blue light can be used in the detection of the pad and an external diameter of the bonded ball while red or yellow light is used for detecting an upper surface of the bonded ball and the ball bonded point.

Abstract: A method of measuring a thickness of a ball bonded to a pad is disclosed. The method includes: taking an image of the pad and the ball at each step position through an image taking means being shifted in a vertical direction at predetermined step intervals; obtaining luminance variations at an edge portion of the pad in each taken image to determine an in-focus height of the pad based on an image taking height position at which the taken image has the largest luminance variation at the edge portion of the pad; obtaining luminance variations on an upper surface of the ball in each taken image to determine an in-focus height of the upper surface of the ball based on an image taking height position at which the taken image has the largest luminance variation on the upper surface of the ball; and calculating the thickness of the ball by finding a difference between the obtained in-focus heights of the pad and the upper surface of the ball.

Abstract: An inspection method of a bonded status of a ball bonded to a pad of a semiconductor chip in wire bonding which attains wiring between the pad of the semiconductor chip and an external electrode is disclosed, wherein an image of a bonding portion between the pad and the ball is taken by an image taking means to detect the bonded status of the ball through image processing of a plane image taken by the image taking means. In the method, coaxial light parallel to an optical axis of a lens of the image taking means is utilized as illumination light illuminating the bonding portion between the pad and the ball, and the color of the coaxial light is switched depending on the details of the inspection.

Abstract: A method of measuring a thickness of a ball bonded to a pad is disclosed. The method includes: taking an image of the pad and the ball at each step position through an image taking means being shifted in a vertical direction at predetermined step intervals; obtaining luminance variations at an edge portion of the pad in each taken image to determine an in-focus height of the pad based on an image taking height position at which the taken image has the largest luminance variation at the edge portion of the pad; obtaining luminance variations on an upper surface of the ball in each taken image to determine an in-focus height of the upper surface of the ball based on an image taking height position at which the taken image has the largest luminance variation on the upper surface of the ball; and calculating the thickness of the ball by finding a difference between the obtained in-focus heights of the pad and the upper surface of the ball.