Contact and connection properties of autocatalytically increased gold-deposits

Abstract

Electroless nickel gold deposits are increasingly applied on iinnovative printed circuit boards (PCBs). The layer thickness of Au deposited bly charge exchange is limited to about 0 2pm. Thus Au-wirebonding is not feasible. With the growing share of chip and wire in mounting technology the interest was focussed on a metallization of PCBs bondable with Au-wires. Thus an autocatalytic process was developed to deposit thicker Au-layers than by immersion gold. The contact and connection properties of these autocatalytically increased Au-deposits are presented. These deposits show excellent perfomance in Au-wirebonding. They can also be applied to the formation of direct connectors. The autocatalytic Au-deposits are resistant against the attack by corrosive gases.