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The interrelationships that exist in Surface Mount Technology (SMT) assembly process are complex and varied. One aspect of the complex SMT relationship is the selection and dispensing of adhesives for the wave soldering of Surface Mount Components (SMC). The quantitative and repeatable dispensing of adhesive dots is critical to providing adequate process control for attaching components including chip resistors, capacitors, and Small Outline (SO) type transistors. Variables that should be considered include the facility temperature and humidity, the size and types of components used on the Printed Circuit Board (PCB), adhesive properties, type of dispenser used to dispense the adhesive, curing requirements, and the soldering time and temperature.

A knowledge based approach, which considers these relationships for the selection and dispensing of adhesives is described. The knowledge based system is developed using PDC PROLOG, and is designed to run as a stand alone system. It is capable of guiding the user in the selection of the proper adhesive for an application, and providing dispenser related information, taking into account the restrictions imposed by the user either as a result of the user's facility temperature, material property requirements, productivity measures including yield, or the process used to dispense the adhesive. It also functions as a database for adhesive related properties and as an on-line installation and maintenance manual for the adhesive dispenser. Twenty one commercially available adhesives and two types of dispensers (air over and positive displacement types) have been considered in this thesis.


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