The RoHS legislation in Europe has far reaching consequences, which necessitates a change in lead coating on component leads. Although some suppliers are using a tin finish, there is a tendency for pure tin plating to form whiskers over time which can cause failure of the circuit. To prevent the formation of whiskers different companies have designed different plating schemes and used different materials. Industry has yet to standardize on a lead finish to replace the Sn:Pb solder used in the past. This paper examines several different lead materials before and after exposure to tin whisker promoting environments to determine the effects of those environments on the soldered connection. In addition to promoting the growth of tin whiskers, these stressful environments also age the solder connections. Based on components used in the telecom industry, solder connections are examined for the presence of tin whiskers, grain structure, intermetallic formation and cracking after being temperature cycled (-40 °C to 85 °C) and soaked at 50 °C and 85% RH.
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