3-8 micro inches is quite manageable for electrolytic gold plate over electroytic nickel on pads that have to be soldered. A even beter variation of this is to put 3-8 microinches of electrolytic palladium between the gold and nickel. The palladium greatly improves solderability if the board is subject to long storage, heat sink bonding operations at higher temperatures or high humnidty atmosphere during storage or assemble prep. This process is used frequently for boards that must experience near 200 dg, C. operation temperatures. It is desireable to keep the palladium thickness below 20 microinches as it subject to solder joint embrittlement similar to the problem with gold when the gold is over 10 micrincbes thick. Phil Hiinton Hinton PWB Engineering . --------------------------------------------------- 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 -----------------------------------------------------