[This e-mail is confidential and may also be privileged. If you are not the intended recipient, please delete it and notify us immediately; you should not copy or use it for any purpose, nor disclose its contents to any other person. Thank you.] We used to spec 4.5 microinches gold over 150 microinches Nickel for our ENIG boards, but after too much late night reading of ENIG Blyton Horror Stories and some soothing remedies, I have specified 5 micoinches immersion gold over 235 microinches electroless nickel with a 1 micron min surface finish for the copper and nickel layers prior to the next metalisation. I have also tried to ensure that the nickel plating bath phosphor levels aren't too high by requiring that it be between 6% and 8% at time of plating. The gold thickness is a compromise between protection of the nickel plating underneath and minimising gold embrittlement of solder joints. The increased nickel thickness is to give a thicker barrier to copper migration. The surface finish spec is to minimise undesirable metallic interaction, and the phospohor level requirement is to try and ensure we don't suffer from the dreaded Black Pad and/or reduced solder joint strength. Hope this helps for your data collection Pete Duncan Rick Thompson <rthompson@VENTURAELECTR To: [log in to unmask] ONICS.COM> cc: (bcc: DUNCAN Peter/Asst Prin Engr/ST Aero/ST Group) Sent by: TechNet Subject: [TN] Solder vs Gold Pads on SMT <[log in to unmask]> 08/22/01 01:52 AM Please respond to "TechNet E-Mail Forum." With all the discussion of ENIG, I was wondering if there are any 'standards' as to the thickness of the immersion gold and nickel? Anyone care to share what information you spec to your PCB vendor to ensure you get the finish you want? Thanks in advance, Rick Thompson Ventura Electronics Assembly 2655 Park Center Dr. Simi Valley, CA 93065 +1 (805) 584-9858 x-304 voice +1 (805) 584-1529 fax [log in to unmask] --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------