Computational modeling and validation of the encapsulation of plastic packages by transfer molding

This paper presents, discusses, and compares results from experimental and computational studies of the plastic encapsulation process for a 144-lead T QFP package. The experimental results were obtained using an instrumented m olding press, while the computational predictions were obtained using a new ly-developed software for modeling transfer molding processes. Validation o f the software is emphasized, and this was done mainly by comparing the com putational results with the corresponding experimental measurements for pre ssure, temperature, and flow front advancement in the cavities and runners. The experimental and computational results were found to be in good agreem ent, especially for the flow-front shapes and locations.