Design and experimental study on droplet-on-demand jetting system for multi-materials

To satisfy the increasing demand for multi-material dispensing in microelectronics industry, this paper presents a multi-dispensing-module droplet-on-demand printing machine. The dispensing- module consist a pneumatic diaphragm droplet generator for molten metal, a piezoelectric piston droplet generator for low viscosity fluid and a mechanical valve droplet generator for high viscosity fluid. Image acquisition system with digital and analog camera for the visual guiding and droplet producing process image collection are established. A three dimensional stage and a rotary stage with motion card and PC (personal computer) forms the positioning system to realize the accurate position of droplet jetting. This data-driven nature of proposed structure greatly improves the system flexibility with which the user can dynamically configure the desired materials for microelectronics manufacturing and assembling. Experimental study on the printing machine for molten metal, mixture of DI water and glycerin solution, and epoxy resin was carried out. The result of the present work implied that the developed multi-dispensing-module droplet-on-demand system can achieve a flexible and friendly user interface, while dispensing a wide range of functional materials using various types of droplet generators.