微滴喷射技术是一种数字化控制微米级液滴产生和分配的技术,在微电子封装和微光学器件制造等领域具有极大的应用前景。提出一种压电驱动膜片式微滴喷射技术,阐述微喷工作原理,基于黏性流体力学进行微喷过程的理论分析并分析影响微滴喷射的关键参数。使用计算流体动力学(Computationalfluiddynamics,CFD)软件基于流体体积法(Volumeoffluid,VOF)的二维轴对称模型对微喷过程进行数值仿真,通过数值仿真分析按需喷射的机理和卫星滴产生的原因,并总结参数对微滴直径和微滴喷射速度影响的规律和经验公式。根据仿真研究结果设计压电驱动膜片式微喷装置,并构建微喷试验系统,试验结果与仿真结果吻合较好,说明提出的仿真方法是可行的。该微喷技术可实现1~150cP黏度范围流体材料的按需喷射,喷射频率可达300Hz,且微滴尺寸具有良好的一致性。
Micro-droplet jetting technology, a digital controlled micro-droplets generation and dispensing technology, is showing strong potential for application. A piezoelectric actuated diaphragm-driven micro-droplet jetting technology is presented to overcome the defects of the existing microjetting technology. The primary principle of the piezoelectric actuated diaphragm-driven microjetting technology is introduced and theoretical analysis is made to establish the mathematical model. Two-dimensional axisymmetric simulation model is built to predict the fluid interface during microjet process by CFD software and volume of fluid(VOF) method. The effect of the parameters on the droplet ejection characteristics based simulations is analyzed, such as droplet diameter and droplet ejection velocity. On the basis of the simulation results, a piezoelectric actuated diaphragm-driven microdroplet jetting experimental system is developed and made experiments using liquid material with viscosity ranging from 0 cP to 150 cP. The experiments demonstrate that this microjetting technology has a good performance on micron droplets generation and dispensing. And the experimental results agree well with the simulation results, which proves this simulation model and method is correct.