Tin whiskers and other packaging problems

[ppppenguin]

AFAIK, the main reason for extreme cleanliness in semiconductor production is the minute detail in modern devices. A tiny speck of dust in a photolith process can ruin an entire chip. By comparison AF11x, BCxxx are huge and you'd almost need the metaphoric half brick to do much damage. Chemical contamination is another matter, I've no idea if lack of purity in reagents would be a problem.