Phil, that is true but what about where a design is symmetrical all good practices have been complied with, and has been made for a number of years with successful flatness and suddenly multiple sources of the same board can't hold the flatness. I not talking missing by just a little bit, I am talking will not lay flat enough to even screen on solder paste. Don't you think this has some other cause? And if so what is this other cause? ---------- From: Hint pwb1 To: [log in to unmask] Subject: Re: [TN] Board Flatness