Currently experienced this problem on a product which had been running satifactorily for a period of time. No process changes were made, The problem was highlighted when after ICT when the boards were loaded in to the stress chamber, after the cycles were completed we found that predominantely 0603 caps and resistors were coming off in the stress chamber. On inspection prior to the stres chamber test there is small evidence in the solder joint of small pin holes, What I would like to know is what this could have been caused by, and due I have a reliabilty issue issue with these boards?
Don�t kid yourself Sal, either: * Components were always falling off your board, but someone just noticed it ... OR * Something in your process HAS changed ... OR * Both
Voids are primarily process indicators. I won't comment on the cause of the voids, because there are too many possibilities to check.
There is no standard, IPC or otherwise, on voids -- nor should there be. There is experimental evidence that voids retard crack propagation locally around the void on a temporary basis. The reliability of your product depends on the design, manufacturing processes and controls, and end-use environment.