Design and Implementation of a Flexible Intelligent Electronics Remanufacturing System

Abstract

Electronic manufacturing of circuit boards has undergone major changes in the last decade as new technologies have emerged and are perfected to replace older ones. A result of the increased board layout densities and higher levels of integration at the chip level is a dramatic increase in the value of circuit boards. The benefit is much more functionality in smaller boards, but the disadvantage is significant losses when a defective board must be scrapped. The same technology that has increased the density of the board functionality has made manual rework to correct manufacturing defects almost impossible. Higher levels of circuit integration in moving from VLSI to ULSI (Ultra Large Scale Integration) have required more pin-outs on the packages which in turn has resulted in finer lead pitches and a change from through-hole mounting to surface mounting technology (SMT). These two changes, with the decreased interchip spacing, have necessitated the use of automation to perform reliable component replacement on defective boards. This paper discusses the complexities of integrating several automation technologies into a single robotic electronic remanufacturing workcell. Involved are vision guidance, control software development, and multiple special end-effector designs for the several required steps, including defective component removal, board cleaning, solder paste dispensing, component placement, and laser soldering [1].