you need true hard gold. electrolytic Ni over Cu 1st... either Ni  
harden or Co harden gold (bath chemistry... not just what ever  
diffuse from substrate).  old mil std has all the hard gold spec. and  
gold purity % requirement...  your 5 microinch doesn't cut it... gold  
price is not that high compare to how much you use... find a good  
vendor who does a decent job is priceless.
On Nov 1, 2016, at 11:27 AM, <[log in to unmask]>  
<[log in to unmask]> wrote:

> This is true on a PWB gold finger.   How about a connector contact  
> pin/button?   The contact has no edges per say.
>
> Victor,
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Mattix, Dwight
> Sent: Tuesday, November 01, 2016 10:03 AM
> To: [log in to unmask]
> Subject: Re: [TN] Hard Au vs ENIG detection (was [TN] Test)
>
> X-section will tell very quickly whether it's hard Au or ENIG.   
> Hard gold will have an overhang that extends out beyond the  
> underlying etched copper.
>
>
> Hard gold is indeed an electrolytic process. As such, except in a  
> few very specialized pwb fabs, it is applied before the outer layer  
> is etched. The unetched, solid copper outerlayer serves as the buss  
> for the electrolytic plating.  A photoresist is applied to the  
> outerlayer first so that the NiAu is plated on as the outerlayer  
> circuit pattern. Then the photoresist is removed to expose the  
> underlying copper. The panel is then etched and the NiAu pattern  
> serves as the etch resist for the outerlayer circuit image.  As  
> that copper is etched down to the outer layer of laminate, it also  
> etches horizontally back under the NiAu. The result is an  
> overhanging "cornice" of NiAu along all the etched circuit edges.
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Giamis, Andy
> Sent: Tuesday, November 01, 2016 7:45 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
>>>
>>