On the flow rate dynamics in time-pressure dispensing processes

Abstract

Time-pressure dispensing has been widely employed in electronics packaging manufacturing, where the fluid (such as encapsulant, epoxy, adhesive, etc.) in a syringe is driven by pressurized air and delivered onto boards or substrates. In such a process, the flow rate dynamics is critical in controlling the amount of fluid dispensed, yet extremely difficult to represent due to its complex behavior. This paper presents the development of a model of the flow rate dynamics in time-pressure dispensing, taking into account both air compressibility and fluid inertia. Experiments have been conducted to verify the effectiveness of the model developed.