Patent ID: 8149276

Claim:
A pressure-bonded ball diameter detecting apparatus, comprising: a camera for capturing: an image of each of rectangle-shaped pads of each of a first pad group and a second pad group that are provided on a surface of a semiconductor chip, the first pad group including the rectangle-shaped pads arranged along a short side direction of the pads and wires each extending from a pressure-bonded ball that is bonded to each rectangle-shaped pad and across a short side of the corresponding rectangle-shaped pad, the second pad group facing toward the first pad group in a long side direction of the rectangle-shaped pads and including the rectangle-shaped pads arranged along the short side direction of the pads and wires each extending from a pressure-bonded ball that is bonded to each rectangle-shaped pad toward a direction opposite of a direction to which each wire of the first pad group extends; and an image of each pressure-bonded ball bonded to each rectangle-shaped pad of the semiconductor chip by a bonding apparatus; and an image processing unit connected to the bonding apparatus and for processing the images captured with the camera, the image processing unit being configured to include: outline acquiring means for acquiring, from each image captured with the camera, an outline of each pressure-bonded ball and an outline of a short side of each pad, the side being opposite of a direction to which each wire extends from the corresponding pressure-bonded ball; bonding-control-center position acquiring means for acquiring, from the bonding apparatus, a bonding-control-center position of each pressure-bonded ball; and pressure-bonded ball diameter calculating means for calculating a diameter of the pressure-bonded balls by calculating first tentative radii and second tentative radii and averaging the first tentative radii and the second tentative radii of the same number, each first tentative radius being obtained by subtracting a distance in a longitudinal direction of the pads between the outline of the short side of one of the pads included in the first pad group and the outline of the corresponding pressure-bonded ball from a distance in the longitudinal direction of the pads between the outline of the short side of the pad included in the first pad group and the bonding-control-center position of the corresponding pressure-bonded ball, each second tentative radius being obtained by subtracting a distance in the longitudinal direction of the pads between the outline of the short side of one of the pads included in the second pad group and the outline of the corresponding pressure-bonded ball from a distance in the longitudinal direction of the pads between the outline of the short side of the pad included in the second pad group and the bonding-control-center position of the corresponding pressure-bonded ball.