Hi Gunter - epoxy works quite well for preserving a gold plated layer as a
hard overcoat. You need to be very careful and have a strict
grinding/polishing procedure but does work so we'll have to agree to
disagree on that point. I do wish I had a FIB for such work!

Dave

On Tue, Oct 18, 2016 at 10:44 AM, Grossmann, Günter <
[log in to unmask]> wrote:

> Seeing the gold in ENIG in microsections with optical microscopy is in my
> experience quite difficult because the wavelength of the visible light is
> 400- 700 nm. Also the epoxy cannot inhibit the smearing of the Gold in
> mechanical polishing. We usually measure the thickness of the gold with a
> FIB preparation (Well, might not be an instrument that stands in all labs,
> thus not really cost effective).
>
>
> Best regards
>
> Günter
>
>
>
>
> > -----Ursprüngliche Nachricht-----
> > Von: TechNet [mailto:[log in to unmask]] Im Auftrag von David Hillman
> > Gesendet: Dienstag, 18. Oktober 2016 17:16
> > An: [log in to unmask]
> > Betreff: Re: [TN] Measuring Gold Thickness
> >
> > Hi folks - another option that can be used instead of overplating is a
> good
> > epoxy material. Just make sure it provides good edge retention. I have
> been
> > using a couple of the nonreworkable epoxy underfill materials very
> > successfully.
> >
> > Dave
> >
> > On Tue, Oct 18, 2016 at 9:59 AM, Stadem, Richard D. < Richard.Stadem@gd-
> > ms.com> wrote:
> >
> > > I believe Hunter still provides that option. Works quite well, I
> > > recently plated a number of PWBs with it and the XrF looked great.
> > > http://www.hunterproducts.com/plating_pens.html
> > >
> > >
> > > -----Original Message-----
> > > From: TechNet [mailto:[log in to unmask]] On Behalf Of Vladimir
> > > Sent: Tuesday, October 18, 2016 9:31 AM
> > > To: [log in to unmask]
> > > Subject: Re: [TN] Measuring Gold Thickness
> > >
> > > Overplating is a must. Unfortunately Buehler stopped selling thier
> > > E-Ni kit at least couple years ago.
> > >
> > >
> > > Vladimir
> > >
> > > SENTEC
> > >
> > > Sent from my BlackBerry 10 smartphone on the Rogers network.
> > >   Original Message
> > > From: Bev Christian
> > > Sent: Tuesday, October 18, 2016 10:25
> > > To: [log in to unmask]
> > > Reply To: TechNet E-Mail Forum
> > > Subject: Re: [TN] Measuring Gold Thickness
> > >
> > > Bob,
> > > Please excuse my previous short answer, but my wife and I were out
> > > walking the dog.
> > >
> > > "Cost effective". "Single use". Find a friend with an XRF.
> > >
> > > Here are some suggestions.
> > > 1) Use a Fischer, CMI, Oxford, Shimadzu or other known brand. I would
> > > NOT use a handheld, even if they say you can do thickness measurements
> > > (Not sure if they are able/touting this ability).
> > > 2) Make sure it is calibrated with a set of standards (also
> > > calibrated!) similar to your sample (ENIG standard set for ENIG,
> > > electroless gold over copper for same sort of sample)
> > > 4) Use as large an aperture as possible
> > > 5) Make measurement on a flat sample surface
> > > 6) Make sure there are no obstructions between the incoming beam and
> > > the sample surface and the sample surface and the detector
> > > 7) Don't skimp on the time for the measurement. Use 30 seconds to 2
> > > minutes.
> > > 8) Measure in more than one spot!
> > >
> > > Typically for ENIG you will get +/- 5% for the gold and +/- 10% for
> > > the nickel.
> > >
> > > I agree with George with regards to cross-sectioning. If you are going
> > > to do it, you should probably over plate with nickel first.
> > >
> > > Regards,
> > > Bev
> > >
> > > -----Original Message-----
> > > From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Wettermann
> > > Sent: Tuesday, October 18, 2016 10:01 AM
> > > To: [log in to unmask]
> > > Subject: Re: [TN] Measuring Gold Thickness
> > >
> > > Gents/Ladies:
> > >
> > > This would be confirming gold plating thickness after repair using a
> > > brush plating technique. Repair thickness is a function of many
> variables....
> > >
> > > I was looking for an instrument to verify that would be cost effective
> > > as it is for this single use.
> > >
> > >
> > > Bob/BEST
> > >
> > > On Tue, Oct 18, 2016 at 8:37 AM, Bev Christian
> > > <[log in to unmask]
> > > >
> > > wrote:
> > >
> > > > XRF
> > > >
> > > > Bev
> > > >
> > > > Sent from my BlackBerry 10 smartphone on the Bell network.
> > > > Original Message
> > > > From: Bob Wettermann
> > > > Sent: Tuesday, October 18, 2016 9:28 AM
> > > > To: [log in to unmask]
> > > > Reply To: TechNet E-Mail Forum
> > > > Subject: [TN] Measuring Gold Thickness
> > > >
> > > > Outside of x-sectional measurements for QA. can someone please share
> > > > their favorite method/instrument for measuring gold thicknesses on
> > PCBs?
> > > >
> > > > Thanks
> > > >
> > > > Bob/BEST
> > > >
> > >
> > >
> > >
> > > --
> > > Bob Wettermann
> > > BEST Inc
> > > [log in to unmask]
> > > Cell: 847-767-5745
> > >
>