Hi all, What would you recommend as a minimum thickness for Nickel plating on a flex circuit? We have specified 150 uin followed by 30 uin gold on top and sides of conductors to prevent copper electrochemical migration. This has worked. However, we may have to reduce this requirement to meet a supplier's capability. I looked up the specification information in IPC-6013 and got min 40 uin (Class 1), 50 uin (Class 2 and 3). Same thing in IPC-2221 except there's a statement in para 4.4.5 that says "...It is an effective barrier layer (when its thickness exceeds 2.5 um) which prevents the diffusion of copper into gold." I calculate the 2.5 um to be approx. 100 uin, which is what many have said in searching the archives. My thoughts are along the line if copper can migrate into the gold, than it can reach the surface and have the potential of creating the dendritic short. So, now I'm stuck. Would you say 100 uin Ni is O.K.? What about 70, or 50? Thanks for your help. Glenn P.S. I don't have IPC-2223. Would somebody mind checking the numbers there for me? ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################