Is it the bond failing, or is the pad being levered off the board? Does your CM do any kind of pre-placement solder paste inspection to ensure that sufficient deposits of paste are being left? Is it always the same pad, or does it vary? Can you increase the pad size? Mike H On Thu, May 19, 2011 at 9:58 AM, wrote: > > When these boards go through our production testing, which includes > > several cycles of hot (85C) and cold (-40C) temperatures, we find > > that the solder bond between the PCB pad and the connector pin fails, > > which in turn causes the unit under test to fail. > > My first question would be what sort of strain relief is there in the lea= d. > It sounds to me like it is not the solder joint at fault, more that when = the > metal lead shrinks as it cools it pulls the lead off the pad. If there is= no > loop in the lead to give it some expansion/contraction ability the fault = you > are seeing is exactly what I would expect. > > For space qualified assembly work all leads like you mention should have > some form of Z strain relief in them. The sort of temperature range you a= re > testing to is the non-operating survival temp range we would use. > > > -- > Scanned by iCritical. > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .