ya know, every time I think I know enough about a particular subject,
something comes along to make me realize there is more to it....

I need to order some boards using a fabrication drawing that hasn't been
updated in over fifteen years.
We need Hard Gold Electroplating for a rotary switch contacts.
One of the notes calls for gold knoop hardness 200-300, thickness 130-230
uin. 93.7% purity
 The last FAI report showed gold thickness of 160 uin. All other historical
records are lost in the shifting sands of time

Our vendor has knoop hardness 150, 99.7% purity and says gold requirement is
too thick.

IPC says knoop 150, gold minimum 31.5 uin. for edge connector fingers, which
I assume is the same for contacts (doesn't seem to be addressed)

Printed Circuits Handbook says knoop 150,  thickness 25-50 uin for
non-military, 99.8% gold purity

Has gold plating changed that much since then?
Is there a danger of wear-out if I get 50uin. gold plating when our old
boards were 160 uin.?

surfin' the learnin' curve,
Jack


______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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 847-615-7100 ext.2815
-----------------------------------------------------