Ask the Experts
June 8, 2009
How to eliminate micro solder balls?
We see significant numbers of micro solder balls after the solder wave process, especially on the SO14 and SOT23 SMD components.
We use a water soluble flux and SNC100 solder alloy. Where should we look for solutions to reduce this solder ball problem?
Expert Panel Responses
Check the solder resist cure as this will be the most significant factors.
Take a ball under at least 60x magnification and carefully turn it over. If it is flat on the side sticking to the resist then it is due to poor cure OR insufficient hardener when the resist was applied.
Technical Sales Manager
BLT Circuit Services Ltd
Greg York has over thirty two years of service in Electronics industry. York has installed over 600 Lead Free Lines in Europe with Solder and flux systems as well as Technical Support on SMT lines and trouble shooting.
Try a different flux.
We have seen similar effects on such mundane things as barcode labels on the board surface.
Jim Willimas is a PhD Chemist in Polymers and Materials Science. He specialize in printing, cleaning, inks, and coatings used in electronics manufacturng operations. Williams has more than 30 years experience.