Method for Making Solder-top Enhanced Semiconductor Device of Low Parasitic Packaging Impedance

摘要

A solder-top enhanced semiconductor device is proposed for packaging. The solder-top device includes a device die with a top metal layer patterned into contact zones and contact enhancement zones. At least one contact zone is electrically connected to at least one contact enhancement zone. Atop each contact enhancement zone is a solder layer for an increased composite thickness thus lowered parasitic impedance. Where the top metal material can not form a uniform good electrical bond with the solder material, the device die further includes an intermediary layer sandwiched between and forming a uniform electrical bond with the top metal layer and the solder layer. A method for making the solder-top device includes lithographically patterning the top metal layer into the contact zones and the contact enhancement zones; then forming a solder layer atop each of the contact enhancement zones using a stencil process for an increased composite thickness.