At 09:17 AM 8/27/2006, Marcel Duchamp wrote: >If you read the data sheets for resistors and capacitors you will find >they recommend against *ever* touching the component directly with a >soldering iron. The reason is thermal stresses cause micro-cracks in >the component that lead to subsequent failure. The actual failure rate >is low; boards I stuffed with an iron years ago still work - mostly. >But we had one experience where many of the parts did fail. They were >.1uf - hundreds of them. Those used as bypass caps were not noticed; >those used as filters in RC networks were disasters. We solder a fair number of smt parts by hand without much problem. However, we bake any moisture-susceptible parts first. These include any ceramic capacitors and most epoxy-encapsulated parts (ICs, transistors). We had one board run with an enormous failure rate (shorted or leaky 100n mono caps) - sure enough, parts not baked first. Oops. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 22 years of Engineering Innovation (1984 - 2006) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist