Hi Ryan! If the QFPs do have a palladium finish then what may be happening is the flux activators from your solder paste are not effective in promoting wetting (you may not have a temperature issue at all). I have experienced some problems with Pd finishes - some flux formulations do not seem to be compatible in promoting wetting as well as other flux formulations. You may need to alter the flux formulation in your solder paste to achieve successful results. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] Ryan Jennens <[log in to unmask]> on 02/17/2000 01:41:09 PM Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to Ryan Jennens <[log in to unmask]> To: [log in to unmask] cc: Subject: [TN] Tin/Silver Paste and Palladium Hey Everybody- We are using 96.5/3.5 tin/silver solder paste on our top side and I have been noticing that on some QFPs the paste forms a heel fillet, a negligible toe fillet, and does not wick over the top of the lead "foot". I am checking to see of the components have a palladium finish (I am pretty sure they do). If it turns out they do, is there an issue with tin/silver paste and palladium coated leads? We are peaking at 230-235 C (ten zone convection Conceptronics) so the boards are getting plenty hot. Why does the paste seem to bulge up at the toe fillet, but not wick onto the lead surface? -Ryan Jennens TelGen Corporation