You could try baking the board before it is wave soldered. Put the board through the wave solder process while it is still hot. You could increase your flux content in the plated through hole (barrels) by increasing the pitch or the pump pressure for the sprays. If you are using a no-clean/low-residue, even though the base alcohol or water has dried, the flux solids should still be on the surface. What speed are you running through the machine? Pre-baking this CCA may help the most. Around 200 degrees "F" long enough to heat up the CCA. Careful not to bake to long and degrade your solderability. ______________________________ Reply Separator _________________________________ Subject: ASSM: Top fillet formation Author: [log in to unmask] at INTERNET Date: 12/20/96 6:58 AM Hello Technetters, I need some advises. I have a 6- layers board. I try to wave solder it, the solder at the ground point is not able to flow up to the top side of the board, in fact, it doesn't flow above 75%. We have tried using a solder-iron and set to temperature to 450 deg. cel. and hopefully able to force the solder through the PTH. Too bad, it didn't work anyway and it in fact has caused some lifted pads. We use full blow Nitrogeneous wave-solder machine, and the flux we use is only 1.2% solid content. And if the preheat temperature set to high, the flux gets degraded before it even reaches the wave.. I would like to know if anyone could advise me how wave-solder such a board with a great heavy thermal mass. Thanks in Advance.. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-==-=-=-=-=-=-=-=-=-=-==-=-=-=-=. / Kong Hui Poh / / Techgate / / - The Technological Gateway - / / Email Add: [log in to unmask] / / / / Fax Number: (65) 842 0318 / / ............................................................................ ................................../ /_________________________________________________________________/ *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************