Hi Steve, Interesting discussion you have brought to the fore and you have gotten some excellent advice on cleaning. It was not stated but I am assuming gold wire bonding based on the thickness and as well assuming that the gold is not selectively plated on the wire bonding pads. My experience from past lives was that 1 micron was normally enough, however, there were not two extra press cycles (with attendant volatilization and deposition of organic materials and a reflow operation that preceded wire bonding). I have worked with folks wherein millions of devices were wire bonded post reflow assembly using aluminum wedge bonding. The gold for such was about 1/5 micron Brian has suggested and it has been seconded that porosity might be in the mix. I am left with a few questions whose answers that might lead me to ask better questions. Is the soldering leadfree? (higher temperatures? volatilized organics? ) Have you looked at the positity/diffusion issue? (i.e. Is Ni really there?) Or is the offending layer organic by analysis? Last (for the moment anyway... ;-) what thickness of gold would be considered pore free? 1.5 microns?, 2.0? 2.1? (I know that there are plating related issues that mitigate any answer) and would that work for all steps in the process? (embrittlement has already been cited as a concern but where is the wall for this process combination?) Gold is expensive but not so expensive as the board. I have had customers in the past that specified 1.5 microns and never had a problem (make that never reported back a problem) We all like a good problem but the real objective is to find a way to make them never show their faces in production. It's pretty boring but very cost effective :-) Good luck, Joe --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------