Tin in solder or some other meals can form spiky crystals when under stress. These whiskers can form short circuits if not properly insulated or not alloyed with other metals.
Tin in solder or some other meals can form spiky crystals when under stress. These whiskers can form short circuits if not properly insulated or not alloyed with other metals.
Tin whiskers have also been identified as the cause of some satellites going down too, so spacecraft definitely still using leaded solder.
https://nepp.nasa.gov/whisker/failures/index.htm
Also recommend looking at the homepage of that site. Lots of cool pictures and research papers on metal whiskering.