Run by Run Control of Time-pressure Dispensing for Electronics Encapsulation

To alleviate the influence of gas compressibility on the process performance of time-pressure dispensing for electronics encapsulation, a predictive model is developed based on power-law fluid to estimate the encapsulant amount dispensed. Based on the simple and effective model, a run by run (RbR) supervisory control scheme is delivered to compensate the variation resulting from gas volume change in the syringe. Both simulation and experiment have shown that the dispensing consistency has been greatly improved with the model-based RbR control strategy developed in this paper.