Experimental and statistical study in adhesion features of bonded interfaces of IC packages

The existence of defects in the corresponding interfaces can gradually degrade the interfacial adhesion when the flip chip package is exposed to the high temperature and humidity. This study used the fuzzy controller to stabilize both the moisture weight gain and adhesion strength together for the button shear test specimen. Parameters design, although based on the Taguchi method, can optimize the performance characteristic through the setting of process parameters and can reduce the sensitivity of the system performance to sources of variation. However, most published Taguchi applications to date have been concerned with the optimization of a single performance characteristic only. For example, it is only concerned a single performance characteristic with the optimization of the adhesion strength or the moisture gain weight individually. In this study, the control rules of the fuzzy controller were formed using the authors’ experience and knowledge of the IC packaging process. The control parameters to be tuned were the membership functions. Therefore, the controller’s performance depended on the membership functions. The fuzzy controller combined Taguchi parameter design, which makes the control performance insensitive to the operating condition changes and noise was used to determine the membership functions.