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
> >
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