Hi, some time ago, Mike Bailey brought up a situation of random non-wetting on the secondary side. Well, I run into a somewhat similar problem right now. After wave soldering, I see SMT passives that are on the solder side exhibiting either non-wetting at all, or one side soldered while the other one looks just like before the wave, no sign of wetting. Even on the pads without components, the situation is the same, some pads have absolutely no trace of solder, while the adjacent ones collect solder without any problem. Not related to shading, since bad spots are even far from any component. Not related to glue contamination either, since I have trouble even with pads without components. To make it even more complicated, there is no problem to hand solder the non-wetted pads, after the wave. I refreshed the flux, ran the assemblies on two totally different machines (different preheating, fluxing), with the same poor result. The process is: glue & insertion + reflow at 120C for the bottom side, only passives populated paste & insertion, reflow for the top wave with no-clean X33 flux from Multicore and regular eutectic solder board is HASL I know this is a mild flux, but it does a great job for us on much more demanding assemblies. I will try a stronger one, but cleanliness is a big issue. Now, I would like to know if Mike found something and if he could fix anything. Besides that, any hint that Technet could give would be largely appreciated. Thank you, Ioan --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------