Experimental and modeling study on viscosity of encapsulant for electronic packaging

In electronics packaging manufacturing, the adhesive materials are delivered on the microelectronic products using the dispensing technology. In the dispensing process, the dispensed volume of adhesive will be affected by its viscosity. The adhesive viscosity will be affected by many factors, such as shear rate, temperature and curing. In order to have good dispensing consistency, the adhesive viscosity should be studied and modeled. In this paper, a viscosity model is constructed to characterize the effects of shear rate, temperature and curing. The experiments verify that this model can well estimate the viscosity variation, and the droplet consistency can be improved significantly when the jetting temperature is set using this model.