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Wed, 14 Apr 2010 16:14:24 -0500 |
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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
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