New high reliability IC bonding film and its development

The die-attach adhesive used in CSP (Chip Size Package) is a crucial component that determines the reliability of CSP. This paper will describe a die-attach adhesive film with high reliability that has been developed using ePTFE (expanded polytetrafluoroethylene). Two structures have been made: tri-layered and mono-layered adhesive films and their characteristics and differences are studied. Also, thermal residual stress and warp deformation behavior of BOC (Board On Chip) and the /spl mu/BGA/sup /spl reg// package are analyzed with a viscoelasticity simulation. It is determined from this simulation that a BOC package using thin mono-layered adhesive film has nearly the same reliability as /spl mu/BGA/sup /spl reg//.