Sequential Multiple Response Optimization for Manufacturing Flexible Printed Circuit

Problem statement: Flexible Printed Circuit or FPC, one of automotive electronic parts, has been developed for lighting automotive vehicles by assembling with the LED. The quality performances or responses of lighting vehicles are relied on the circuit width of an FPC and the etched rate of acid solution. According to the current operating condition of an FPC company, the capability of the manufacturing process is under the company requirement. The standard deviation of FPC circuit widths is at higher levels and the mean is also worse than specifications. Approach: In this process improvement there was four sequential steps based on the designed experiments, steepest descent and interchangeable linear constrained response surface optimization or IC-LCRSOM. An investigation aims to determine the preferable levels of significant process variables affecting multiple responses. Results: The new settings from the IC-LCRSOM improved all performance measures in terms of both the mean and the standard deviation on all process patterns. Conclusion: From this sequential optimization the developed mathematical model has tested for adequacy using analysis of variance and other adequacy measures. In the actual investigation, the new operating conditions lead to higher levels of the etched rate and process capability including lower levels of the standard deviation of the circuit widths and etched rate when compared.