Solderability testing is a
destructive test that of SMDs to determine if their leads will be perfectly
wetted by solder. Passed components help ensure that the SMD batch will form
electrical and mechanical reliable solder joins during an assembly process. SAC305 is the leading standard for
lead free solder. This is a constraint we can’t change.
When Celestica approached us with
their problem, they revealed that they had many surface mount devices were
failing the solderability test. However, these were false failures.
Solderability testing involves a testing substrate as a medium to simulate a circuit
board on an SMT assembly line. What Celestica found out was that their
substrate of 3.175 mm thick glass was not industry standard and determined SAC
has poor wettability on glass, which restricts solder from wetting SMD leads.