ALPHA® WS-852 is a SnBiAg low temperature, water soluble solder paste designed for a broad range of SMT processes where aqueous post reflow cleaning is required. The low temperature, lead-free alloy enables lower temperature processing of surface mount technology. The SnBiAg alloy reflows between (160-190)oC.
The carefully selected Sn/Bi/Ag alloy in ALPHA® WS-852 was selected to give the lowest melting point, lowest pasty range during melting and re-solidification, along with a very fine grain structure, offering maximum resistance to thermal cycle fatigue. The alloy also yields very low voiding BGA solder joints, even when traditional SAC alloy spheres are used.
All components used with ALPHA® WS-852 must be lead free to eliminate the formation of a tin/lead/bismuth intermetallic which has a melting point under 100oC.