Papers by Author: Yong Cao

Abstract: To reveal the jetting of fine drops, model of 2-phase flow between gas and liquid is offered based on volume of fluid method. Numerical simulation is launched for the droplet generation through narrow nozzle, and key factors are discussed. Aiming at the ink marking of defective dies in IC production, a jetting inker driven by piezoceramic stacks is developed. The actuation properties are derived; waveform of induced pressure at nozzle entrance is estimated, which coincides the numerical results. Performance of ink dot jetting is evaluated and simulation results are verified.

Abstract: Ink marking is a key process for die sorting of IC wafer manufacturing. Intensive production of wafer is urging the inkers for more rapid and more stable ink marking performance on surface of defective wafer dies safely. In this paper, a non-contact jetting dispenser is introduced to the wafer die marking. After presenting the mathematical description of dynamic fluid for 2-phase flow, numerical simulations are launched to reveal the characteristics of droplet generation and key factors are discussed. A jetting dispenser is developed and experimental results are analyzed. According to the simulative results and the dotting performance shown in experiments, the non-contact jetting dispenser is capable for wafer die marking in dotting efficiency and stability.