Electroless nickel on aluminum bodies
Q. My company is trying to solder gold plated feedthrus into an aluminum body that is plated with low phosphorous electroless nickel. We are having trouble getting the braze material to attach and flow on the electroless nickel regardless of our furnace temperature and belt speed. We clean the part to remove any oxide prior to putting the part through the furnace. Is this a problem with the phosphor content? Should we be using a different phosphor content? Or should we be trying electrolytic nickel?Bill Finnegan
- Chartley, Massachusetts
A. Might be phos level; ask how your plater is checking it? All platers like to speed up an EN bath by changing pH, temp, etc. and this can have a definite impact on the P%. My experience is that any P in EN can spell trouble for soldering. Electroless nickel boron is better than EN-P but not widely available. Pure electroplated nickel works well if not overly brightened; sulfamate formulations work best from my experience.
Syracuse, New York