Statistical Optimization of Process Variables In A Continuous Inkjet Process - A case study

This paper investigates a statistical approach to optimizing the process variables in a Continuous Inkjet Process. In a continuous inkjet (CIJ) process miniaturized fluid droplets are deposited onto substrates for microfabrication. A critical aspect of this fabrication process is the precise generation of droplets based on various input parameters. In this research ultra high speed photography was employed to observe the effect of input parameters such as fluid pressure, frequency, and voltage of a piezoelectric disc on the droplet volume. In order to identify the most significant parameters a factor screening test was performed based on a full factorial design. Based on the ANOVA results, it was revealed that fluid pressure, piezoelectric disc frequency and their interaction were the significant factors that affected the droplet volume. A response surface optimization was conducted to determine the variation on droplet volume based the significant factors. A secondorder response surface is established that captures the droplet volume variation over the ranges of the input parameters. The results of this study are vital in determining optimal values of the significant input parameters for microfabrication of electronic devices and micro-electromechanical systems (MEMS) components using direct write technology. © INTERNATIONAL JOURNAL OF INDUSTRIAL ENGINEERING.