A Transistor Wire-Bonding System Utilizing Multiple Local Pattern Matching Techniques

Abstract

A fully automatic transistor wire-bonding system utilizing image-processing techniques is described. The system is composed of a minicomputer, image processors, and a maximum of 50 wire-bonding machines. Each machine has a TV camera installed to pick up, through a microscope, the image of transistor chips fed into the machine. In this system, one image processor services several machines in a group and analyzes the image signals in a time-sharing mode to determine the chip position at each machine. From the detected coordinates, an XY servomechanism in each machine is activated to bond and stretch wires between the electrodes on the chip and the outer leads. The recognition of electrode positions is accomplished by the multiple local pattern matching method in which redundancy is used in achieving a high recognition rate. An analysis of the system and basic features of the position recognition algorithm are also described. This method opens the possibility of economical automation of processes possible only by the human eye to date.