A new type of piezostack-driven jetting dispenser for semiconductor electronic packaging: modeling and control

This paper presents a new type of piezostack-driven jetting dispenser which can be applicable for semiconductor packaging processes. After describing the structural components of the dispensing mechanism and the operating principle, the dynamic modeling is undertaken by considering the behavior of the piezostack, hydraulic magnification, dispensing needle and adhesive fluid. In the modeling, fluid models for the adhesive fluid and hydraulic magnification are derived using a mechanical model which is analogous to the corresponding lumped parameter model. The governing equation of motion is then established by integrating the fluid models with the structural model. Subsequently, the dynamic behavior of the dispenser and its dispensing amount are investigated through both computer simulation and experiment by applying a sinusoidal driving voltage input. In addition, a control system is designed and experimentally realized to control the dispensing flow rate (dispensed amount) of the dispenser.