52

Poor Wetting
Incomplete wetting or poor solder rise in a plated through hole will show up due to poor fluxing or pre heat temperature. If both are satisfactory it will be the surface coating of the board. The trend in the industry is to copper surface finishes but care must be taken over their selection. Special assembly conditions should also apply to storage, washing boards, cure and reflow temperature. A special video on the use of alternative solder finishes is available from EPS.