NWO defects are difficult to detect and may not manifest until after a product is in the field. When a component deforms during reflow, the solder interconnect may be compromised, resulting in non-wet opens (NWO).
Chip suppliers are particularly interested in lower reflow temperatures, as thinner components are needed to meet dimensional limitations of thinner, smaller and faster devices. The most technically significant is reduced warping of component and substrates. Several forces are driving implementation of solders with lower peak reflow temperatures than SAC 305 and its variants. LOW-TEMPERATURE SOLDERING is a subject of considerable interest and development. With no standard in sight, emerging alloys require unique fluxes and processes.