I've recently come across a 3-pole momentary switch (like a car's
ignition) for a PC application. Because of the requirement of 20,000+
cycles of life, both suppliers are using thick electrolytic gold and use
a lubricant. They go as far as requiring No Aqueous rinsing allowed
since this step could remove the lubricant. I suppose it goes back to
what everyone has been saying, application testing is needed. However,
if the part needs to last, nothing beats a thick gold with lubricant.
Don't even bother doing porosity testing on 3-5 microinches of gold. It
will fail. 

Paul Terranova
Analytical and Environmental Test Services Lab
Worldwide Module Components Group
              
 Digital Equipment Corp
 200 Forest Street
 Mail Stop: MRO3-1/D2
 Marlboro,  MA  01752-3085

'    Phone: (508)467-3109
* Fax: (508)467-6796
* Email: [log in to unmask]


        -----Original Message-----
        From:   Paul Gould [SMTP:[log in to unmask]]
        Sent:   Monday, March 23, 1998 1:14 PM
        To:     [log in to unmask]
        Subject:        [TN] FAB: Electroless Nickel/Immersion Gold for
rotary contacts

        Has anyone any experience of using electroless nickle/immersion
gold finish on rotating wiper contact areas of the pwb. Is there a spec
which permits this. I have made circuits for wahing machines with
immersion gold on copper and that worked with a life of about 10 years,
but that was more than 20 years ago. The problem is the cost of hard
plating selected areas.
         
        Any thoughts on this would be appreciated.
         
        Paul Gould
         
         

################################################################
TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################