## Abstract

In this paper, we describe an algorithm developed to inspect bonding wires
which connect the die to the package lead frame. The wire inspection algorithm
first generates the wire candidate points using a simple one-dimensional
gradient thresholding technique before calculating the Hough arrays for each
of the candidate points. The latter operation involves the line-to-point Hough
transformation in which wires are to be represented by straight lines having
parameters (rho, theta), where rho is the distance of the line to the center
and theta is the inclination angle of the normal to the line. Apart from being
able to count the wires and hence capable of detecting wire count aberrations,
this algorithm can also detect crossing wires.