Non-wetting of electroless nickel plating layer after reflow soldering process

Non-wetting of component with electroless nickel plating layer after reflow soldering process was analyzed. Components were observed to be skewed or dropped off from the solder pad of a board after soldering process. Failure mode was observed to be poor wetting and reaction between electroless nickel plating layer and solder pad. EDX and XPS analyses indicates that non-wetting of the components could be due to oxidation of the electroless nickel plating layer. Experiments carried shows that aging or oxidation of electroless plating layer play more significant role as compared to the thickness of electroless plating layer.