A Piezoelectric-driven Single-nozzle Dispenser for Liquid Droplet Jetting

This paper presents a piezoelectric-driven single-nozzle dispenser head using a multilayered piezoelectric actuator for liquid droplet jetting in the fields of semi-conductor packaging and so on. The design, fabrication, and characteristics of the piezoelectric-driven single-nozzle dispenser head are summarized. The proposed single-nozzle dispenser head consists of three major parts: a multilayered piezoelectric actuator, a piston embedded diaphragm, and a micro nozzle with a pressurized dispensing chamber. The overall size of the fabricated single-nozzle dispenser head is 25 mm x 25 mm x 46 mm. The piston embedded diaphragm, which is made of stainless steel, has a diameter of 17 mm and a thickness of 100 mu m. The micro-nozzle specifications are a 100 mu m and a 200 mu m diameter and a 500 mu m depth, and the dispensing chamber height between the diaphragm and the nozzle cover is 300 mu m. The dispensing experiments were performed with deionized water as the working fluid. The dispensing characteristics, such as the liquid droplet volume rate and the visualization of the droplet, were experimentally investigated as functions of the applied voltage and the driving frequency.