ENIG is the less evil for soldered pads.  Immersion gold is self-limiting and thin (2-9 uinches) and the less Au in a solder joint the better to prevent fatigue in duty cycle.  Electrolytic Au has a controlled deposit but difficult in ranges less than a 20 uninch window and also need to be thicker than 10 uinches due to the nature of the plating initiation on the Ni surface.  A range of 20-50 uinches should be achievable by most fab houses with 20-40 also manageable with balanced geometries.     



Jeffrey Bush
Director, Quality Assurance and Technical Support

                          76 Technology Drive - POB 1890
                             Brattleboro, Vermont 05302-1890
                                Tel. 802.257.4571.21 Fax. 802.257.0011
                                    [log in to unmask]
                              http://www.vtcircuits.com	



-----Original Message-----
From: "Janoch Jirí, Ing." [mailto:[log in to unmask]] 
Sent: Monday, September 13, 2004 8:06 AM
To: [log in to unmask]
Subject: [TN] FW: soldering on gold pads


Dear Techneters,
could  you tell me, please,  what  does IPC 6012 write  about gold plated pads  which are soldered ? How thick Au ( microinches) on Ni is good for proper solder joint ? What thickness of Au on pads do you recommend ? Are there any materials on this problem available ?

Many thanks

J.Janoch , TSE
 Czech  Republic

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To unsubscribe, send a message to [log in to unmask] with following text in
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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
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