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November 2016

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Subject:
From:
Gerry Gagnon <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Gerry Gagnon <[log in to unmask]>
Date:
Wed, 2 Nov 2016 12:58:58 +0000
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Andy I'll give you a pass! More detail for history buffs.


If we are talking about a true hard gold for hi-rel connector/contact/PWB Tab applications, we are talking about a cobalt modified gold electroplated from an acid gold cyanide solution electro-plated over a low stress nickel. Solution looks like grape Kool Aid.


The test for determining the hardness of the gold is to use a Vickers diamond indenter. Be aware that to do the test, you must electroplate a thick deposit of gold from the production plating bath over the nickel. I remember using 200 micro-inches minimum gold thickness for the test. The reason for the heavy thickness is to be sure there is plenty of bulk gold below the indenter, otherwise you are testing the hardness of the nickel under-plate, copper, and laminate.


Hard gold plated to 100 micro-inches over 300 micro-inches will pass the "old" nitric acid porosity and easily pass the more modern variants using a few "wiping type" connector insertions before the nitric acid porosity test (which is worst case (compared to a LIF or ZIF.


Due to gold cost, the thickness went down to 70 micro-inches, then 50, then 30, then 15, to the point of who cares. None of this stuff will pass the original nitric acid test.




________________________________

From: TechNet <[log in to unmask]> on behalf of Giamis, Andy <[log in to unmask]>
Sent: Tuesday, November 1, 2016 10:45 AM
To: [log in to unmask]
Subject: Re: [TN] Test

Hi Victor,
The great and all-knowing Wikipedia says hard gold often contains a small amount of cobalt or nickel.
I am also not an expert, but I believe hard gold is an electrolytic process.  Although the electrolytic process can be stopped any time, typically target thicknesses are considerably thicker (30 micro-inches or more).  If you are looking at 5 micro-inches, I'd guess it is immersion gold.  The best action is to ask the supplier.  If that's not an option, try EDS looking for cobalt.  That's no guarantee, but positive results for cobalt would be informative.  5 micro-inches would be too thin to look for nickel.  Good luck.

Did I pass the test?


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of [log in to unmask]
Sent: Tuesday, November 01, 2016 7:19 AM
To: [log in to unmask]
Subject: Re: [TN] Test

Fellow TechNetters:

   I did not receive a response the FIRST time .   therefore I pose the inquiry once again.

"Is there a test or method to determine if gold plating is hard gold or ENIG?     XRF will determine thickness of gold but will not verify plating process.   I am working with a measurement of 5 micro inches of gold."

Victor,

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
Sent: Tuesday, November 01, 2016 7:14 AM
To: [log in to unmask]
Subject: Re: [TN] Test

I don't know about the rest of the folks but I received an A+ and its rumored  you received a C-

Dave

On Tue, Nov 1, 2016 at 7:09 AM, Douglas Pauls < [log in to unmask]> wrote:

> And what percentage of our grade is this test?
>
>
> Doug Pauls
> Principal Materials and Process Engineer Rockwell Collins
>
> On Mon, Oct 31, 2016 at 9:17 AM, Vadim Matveyev
> <[log in to unmask]>
> wrote:
>
> > Test
> >
>

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