I could use some thoughts from those of you involved on the assembly side. We have a customer who appears to have solderability issues with a particular board we have built. We have supplied this product over the last several months using three different surface finishes; white tin, HASL and ENIG. His issue is the same regardless of the surface finish. His first side produces acceptable solderability however the second side exhibits non-wetting and partial wetting. I have one of the ENIG boards after assembly and it shows absolute absence of solder on multiple areas of the secondary side, while adjacent areas are excellent. I have little specific information regarding assembly, except as follows: Screen solderpaste on backside Inspect Pick and place components IR reflow Aqueous clean Screen topside with solderpaste Inspect Pick & place components IR reflow Aqueous clean. I'm told the customer bakes his boards prior to paste screening, however, I have no profile specifics etc. The product in question has no unusual attributes. It's an .062 ten layer board, no thru-hole, SMT two sides, s single BGA and QFP and the typical other passives. Process sequence is typical SMOBC with no via plugging etc. Mike Bailey Director of Engineering TTM Technologies 2630 S. Harbor Blvd. Santa Ana, CA 92704 Phone(714) 241-0303 FAX (714) 241-0708 [log in to unmask] --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------