Critical Soldering Interconnect Technology in SMT

this paper introduced the important soldering interconnect technology in SMT. In electric product manufacturing process, sometime we must place components in through-hole ways , then we use wave soldering. Wave soldering is used for both through-hole printed circuit assemblies, and surface mount. As technology changing very soon, the through-hole components have been largely replaced by surface mount components, this time ,Reflow soldering is the most common method of attaching surface mount components to a circuit board,but not wave soldering also reflowing, we must focus on wetting , It quantifies the wettability of a solid surface by a liquid .wetting angle is a the important quantity (also called contact angle).it can judge the quality of solder joints.