Low stress dielectric layers for wafer level packages to reduce wafer warpage and improve board-level temperature-cycle reliability

This paper presents a negative-tone photoimageable spinon dielectric material that is based on a unique molecule for wafer level packaging application. The molecule is an extended polyimide having photoactive maleimide end groups. It is an ideal alternative to conventional dielectric materials for solving both the wafer warpage and temperature cycle RDL crack issues.