|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Phase Stability, Phase Transformations, and Reactive Phase Formation in Electronic Materials XV
||Electrochemical Evaluation of Copper Etchant to Reduce the Galvanic Etching in Cu/Au Coupled Pads
||Jong-Chan Choi, Young-Hwan Bae, Jinuk Lee, Jae-Ho Lee
|On-Site Speaker (Planned)
In PCB industry, the copper is one of the most used metals in lines and pads. In many line/pad process the copper pads were soft etched to remove the copper oxide on the surface. Shapes and patterns of lines and pads are getting complex and some of pads are covered with Ni/Au for the better solderability. In this case copper made a galvanic couple with Au and then the etching rate of copper connected to Au pads is higher than other copper pads. Consequently the copper line/pads were getting thinner than original line/pad and then the failure can be occurred at this area. In this research, the mechanisms of copper etching at Cu/Au coupled pads were investigated. Open circuit voltages (OCV) at copper and gold surface were measured and compared. Polarization plots were compared. The effects of alcohol, acid and addtives on the etching rate were also investigated.
||Planned: A print-only volume