Quality improvement for Image Printing Process in Automobile Flexible Printed Circuit Manufacturing

Abstract

The objective of the thesis is to determine the optimum condition for controlling the image printing defects in image printing process of Automobile Flexible Printed Circuit Manufacturing. This thesis research starts from using cause and effect diagram to explore all the potential influence factors. Commencing from brainstorming session and knowledge from various relevant documents, all selected factors should be adjustable and controllable without investing additional procuction cost strongly. These factors are consisted of squeegee hardness, wqueegee angle, squeegee cut angle, emulsion thiskness, printing pressure, and printing speed. Due to methodology for thoroughly studying the fators, which affect the process, it will take a long time to research and large cost. So the influence factors were analysed with orthogonal array method L18 (21 x 36) amount 18 runs with 2 replicates and 3 factor levels. The experiment shows that only three factors which were of significant influence. These are emulsion thickness, printing pressure, and printing speed. In additional, the optimum condition for controllomg the image printing defects in image printing process will be determined using one-factor-at-a-time (OFAT) experiment with 21 different runs. The experiment reveals that the appropriate condition as a function of three factors can be set at printing speed 4 m/s, printing pressure 28 Kgf/cm2, and emulsion thickness 2 microns. Finally, confirmation experiment is performed to confirm the result of the experiment between original condition and after improvement condition. As a result, the average ink thickness after improvement is thinner than the average ink thickness before improvement 0.3 microns from 11.1 microns to be 10.8 microns or 2.70%. Therefore, it can implement for controlling the image printing defects in image printing process.