SPC and setup analysis for screen printed thick films

The authors describe some of the key process variables that affect the repeatability of the screen printing process for thick-film circuits and hence the quality of the final product. The discussion of major screen printing problem areas provides insight into the complexity of the overall process and the interrelationship of the process variables. The interrelationships of the key variables and their relative importance to process quality and performance are analyzed using a statistical process control technique, namely statistical design of experiments. The fractional factorial design is used as an example. The setting up of a screen printer is a manual operation. Some simple steps necessary to improve the learning process and record keeping are described based on S. Shingo´s setup time analysis approach (1985)