Hybrid Drying Technology for In-line Aqueous Cleaning of Lead-Free Assemblies

The use of high velocity, heated air to remove residual water has become the predominant method for drying printed circuit boards in the in-line aqueous cleaning process. As lead-free circuit boards become more complex and component spacing decreases, the effectiveness of direct blow-off drying is greatly diminished. Adding blower power or slowing process speed will improve drying performance, but increase operating cost, and may decrease throughput. 

This paper describes a new approach to drying circuit board assemblies that significantly reduces the cost of ownership of an aqueous cleaning system. Drying performance is increased through a hybrid drying process that reduces energy input, exhaust requirements and sound levels. The combination of high temperature blow-off and convection brings the flexibility to tailor drying performance to fit the product’s drying requirements.