Integrated modelling of a time-pressure fluid dispensing system for electronics manufacturing

Abstract

In electronics manufacturing the time-pressure dispensing system has been widely used to squeeze adhesive fluid in a syringe onto boards or substrates with pressurised air. For accurate control of the fluid volume, it is vital to have a thorough understanding of the whole process. However, the complexity of the process, which includes air-fluid coupling and their nonlinear uncertainties, makes it difficult to obtain an accurate process model. Using the spectral method, an approximate fluid flow model for both the Newtonian and non-Newtonian fluid can be developed. By taking into account nonlinear flow passing through the valve, attenuation and time delay in the pneumatic lines, syringe chamber dynamics and fluid flow dynamics, a simple but effective model is derived to describe the whole dispensing system with reasonable accuracy. Experiments performed thereafter validate the model.

Performance characteristics of a high frequency jetting dispenser featuring piezoelectric actuator

“…Till now, several dispensing approaches have been developed and successfully implemented in the semiconductor applications. Essentially, these approaches are classified by the driving mechanism as follows; time-pressure, rotary-screw, positive-displacement and jetting types [4][5][6]. Among these the first three approaches belong to the contact-based dispensing technique in which the dispenser nozzle is required to contact with a substrate or printed circuit board (PCB) via dispensed adhesive during dispensing process.…”

“…In recent years, dispensing systems have been widely used in many industrial applications such as electronics assembly [1][2][3], micro-electro-mechanical systems (MEMS) assembly [4,5], fabrication of soft tissues engineering scaffolds [6] to deliver fluid material in a precisely controlled manner. Especially, in the semiconductor industry, the dispensing system has played an essential role in integrated circuit (IC) encapsulation and surface mount technology in order to protect an IC chip from external environment and prevent its break away.…”

Design and Experiment of a Jetting Dispenser Driven by Piezostack Actuator

“…t d is the fall time of the ball-needle. u max (t) is the velocity at the center of the nozzle, obtained from [10] as…”

Microdroplet generation in gaseous and liquid environments

“…In addition to the geometric and surface properties, the magnitude(s) and length(s) over which pressure is applied influence the final droplet size (Zhao et al 2005).…”