Irving, I've have been through several fluxes so far. Your best bet is something with a small amount of rosin to give the flux enough time on the wave. Currently I have a water based no-clean flux with a small amount of rosin that is working real well on test boards. With regards to trying other surface finishes. There was a paper at SMTAI 06 that mentioned SnCuNi as a surface finish and it had similar erosion traits as SnPb you might want to look into that but you would have to weigh the issues. Best regards, CP To: <[log in to unmask]>, <[log in to unmask]> cc: Subject: RE: [TN] Copper Dissolution Corey, Thanks. It is very worth recommendation. What kind of flux type you recommend ? ENIG is not allowed by our customers, we may need to try other finishing types . Irving -----Original Message----- From: Corey A Peterson [mailto:[log in to unmask]] Sent: Thursday, November 02, 2006 11:55 PM To: TechNet E-Mail Forum; Lee, Irving (§õ©ú©ô TAO) Subject: Re: [TN] Copper Dissolution Irving , There are several options here. 1) Use an ENIG surface finish 2) Use a flux that is a bit more aggressive probably will need some rosin to give it enough legs" to last in the wave that long. Avoid using the chip wave if possibly. You are going to be hard pressed to find a flux that will last that long thru the wave solder pot. 3) Specific minimum copper thickness for the knee 4) Change solder pot to a less aggressive solder alloy 5) Use the best thermal mitigation strategies and where possibly use bigger annular rings. Corey Peterson Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to [log in to unmask] Sent by: TechNet <[log in to unmask]> To: [log in to unmask] cc: Subject: [TN] Copper Dissolution How to avoid copper dissolution during lead free wave soldering ? [1] Printed Circuit Board Size : 13"x16" , Thickness : 0.93" [2] Lead Free Solder Bar Type : SAC = Sn + 3 % Ag + 0.5 % Cu [3] Both sides Reflow prior to Wave Soldering [4] Wave time : 6 sec , Temperature : 265 degree C Irving Lee --------------------------------------------------- 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 847-615-7100 ext.2815 -----------------------------------------------------