Application of Design of Experiments in Metal Coating Process Improvement

RIE Coatings was experiencing an average of 8% fallout in the recess area coating quality of parts. Coating in the recess area used to peel off, crack and was resulting in customer complaints. The objective of this project was to reduce the coating defect in the recess area of different parts and thereby set up an experimentation process to bring down the defect rate from 8% to 4% of the batch. Different factors responsible for quality of the recess coating quality were identified. Factors such as load and spin time were tested at different levels. Two -way analysis of variance (ANOVA) was done to find out the effect of both the factors. It was found that 1 0Olbs load and spin time of 20 seconds resulted in 2% defects which was acceptable. This project was very critical to RIE because the existing defect rate was endangering customer satisfaction. This was also the first attempt by the organization to carry out such experiments for process improvement. Adding more to this, as per current industry standard the recess fill fall-out is 10-15% which is way higher than what RIE was aiming. The extremely low defect rate achieved from this project will provide RIE with an opportunity to dominate the coatings market in the future.