Flow modeling of die attach process and the optimization of process parameters in advance packaging

This paper presents a new numerical model to characterize the die attach process in the advance packaging. With its successful application on a 5 mm by 5 mm with 70um thickness die attached to the substrate, final fillet shape of the die attach material is predicted for various process conditions. Focuses have been given on the die attach material over flow on the die top surface. The contamination on the die top surface may cause failures in the subsequent processes. The simulation results were compared with the experiment. Good match was obtained. Moreover, process window for a given amount die attach material was established through the simulation and the corresponding bonding force that will not cause die attach material over flow was predicted. Key advantage of this numerical study is to give the insights into process parameters and provide initial process window to prevent die attach over flow.