Is there any corrrelation with the gritty sodler joints and dip connections to either the power or ground planes? At 09:10 PM 5/14/96 +0800, Poh Kong Hui wrote: >Dear Technet, > >Whenever, I'm running a 100% through-hole board, that is densely populated >with mainly DIP components, and a only few capacitors and resistors., 20 to >30% of the solder joints are gritty. > >It had never happened to board of mixed technology. >I have sent the solder for lab. analysis, and the result is within the >recommended specification. > >The Board is :- >10 x 10 sq.inch >4 layers > >The wave-solder Machine used :- >The wave-solder machine used is SEHO 2000 - a full-blown nitrogenous tunnel. >The solder pot temperature is set at 245 deg.cel or 473 deg.F. >The top side temperature is measured at about 194 deg.F / 90 deg.C. >Conveyor speed is set 0.90 metre/minute. >The solid content of the flux is 1%. > >Could anybody advise me why this is happening, and how to solve it. Our >rework operators are touching every gritty joint. > > >Poh Kong Hui >Nera Electronics > > Regards, Gary Ferrari Chairman IPC-D-275 Tech Circuits (203)269-3311 [log in to unmask]