Bill, You should be able to get away with 30 microinches of gold. I have gone anywhere from 150-350 microinches of electroless, or electrolytic nickel (subject to board layout constraints) with good success. Word of caution - IMHO, if the board will sees multiple thermal excursions (reflows - not to mention adhesive cure/s), and long WIP times (weeks) before it gets to you, I would opt for heavy nickel, and going heavier on the gold. The reason for this is: With each thermal excusion the base copper tries to find pores/holes in the nickel to diffuse through/into. If successful, the gold is next. Thermosonic gold bonding to corrupted gold is problematic. Thickness just delays the inevitable. Nitrogen storage (at least dry air) is assumed. Steve Creswick - Gentex Corp -----Original Message----- From: Bill Christoffel [mailto:[log in to unmask]] Sent: Wednesday, August 22, 2001 10:04 AM To: [log in to unmask] Subject: [TN] Ni/Au Plating Question Ok all you plating guru's.......I am currently specifying a gold (Thermosonic) wire bondable electrolytic gold for a new board design. This in my mind was the easy part (Mil G-45204, Type III, Grade A, 40-50 microinches thick). Now for the Nickel, Currently we spec. a Electrolytic Ni, 4-9% Phos., 150-200 microinches thick. Questions: Since my bonding is to the gold, is there a concern if the Ni plating is Electroless or Electrolytic. Which is easier to control ? Which is a less expensive process ? Any other concerns I should be aware of ? Thanks, Bill C. ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------