Knowledge-based control of adhesive dispensing for surface mount device assembly

Results of a major project using knowledge-based control techniques to resolve the problems encountered in the dispensing of the very viscous adhesives used to secure surface mounted components to mixed technology circuit boards before wave soldering are reported. The study has two major thrusts: the accommodation of process variability with a rule-based system that controls a manufacturing cell, and the accommodation of material variability with a real-time rule-based process control system. Dispensing problems are caused by variations in the material and system properties with, for example, batch, temperature, and time. A dispensing cell that is able to use a rule-based object-oriented control system to resolve these problems has been integrated