I am really not very sure why but here is what I found.
Before doing the board I tested first on a sheet of paper (just did a 3 inch long trace) to see if indeed it is conductive. And yes .. it is conductive. Not when is wet but after it dries is pretty good (obviously I did it after the thing was melted again - so my tinner was in it)
I checked again the board under microscope, the thing is either scratched of the hole walls, either it dried out "bumpy" instead of nice smooth. This is very inconsistent anyways - some holes were a nice coat some not (like 50/50) - but then the thing was not adhering to the coper layer for others. Probably that's what I messed up using "standard" tinner - surface adhesion - or it was too thick to flow and dry in a smooth coat.
Not giving up just yet. I will do one more try. This time I will dilute a tad more and agitate the nickel as much as I can. To me looks like it was not fluid and homogeneous enough to be smooth like an ink.
One thing is sure - "Nickel Print != conductive ink" :)) .
C
--- In Homebrew_PCBs@yahoogroups.com, Donald H Locker <dhlocker@...> wrote:
>
> Sorry to hear of your lack of success.
>
> It might have been the thinner, though. MG Chemicals says "If thinning is required use M.G. Thinner (Cat. No. 435-55ML)." I looked that up and its MSDS sheet lists ingredients as
>
> CAS 67-64-1 2-propanone 85 - 95%
> CAS 108-65-6 1-methoxy-2-propanol acetate 5 - 15%
>
> This formula is pretty simple but definitely not paint thinner. Many paint thinners cure (oxidise and polymerise) rather than evaporate. MG's thinner is definitely designed to evaporate and leave the metal flake behind. I suspect all the nickel bits are being coated by the paint thinner residue, so the body of the material is non-conductive.
>
> Donald.
> --
> "Plain Text" email -- it's an accessibility issue
> () no proprietary attachments; no html mail
> /\ ascii ribbon campaign - <www.asciiribbon.org>
>
> ----- Original Message -----
>
> > From: "morarcalin" <morarcalin@...>
> > To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
> > Sent: Tuesday, August 17, 2010 1:44:02 AM
> > Subject: [Homebrew_PCBs] Re: Nickel and Silver Print from MG for through hole plating
> >
> > Here is the update regarding Nickel Print - NO SUCCESS
> >
> > So I went ahead and bought a jar of "Nickel print" - 13$ - all good
> > till I open the jar - completely dried out. So I use some paint tinner
> > and leave the thing to melt for about 3 days. I guess was just plain
> > bad luck I got this really old evaporated stuff.
> >
> > After 3 days I finally got something that resembled nail polish - hmm
> > not bad!!! So I etch one my ARM breakout boards. I use Stellaris
> > LM3S308 MCU - which is a 48 LQFP package with 0.5 pitch (yes I solder
> > these by hand :)). The board has about 15 vias that are pretty big -
> > 50mils pad and 10mil holes.
> >
> > First I drilled the holes (carbide at 35K RPM)... then I scotch taped
> > the board both sides (it is a double sided board) and deburred all
> > holes (same drill at only 5K RPM). This has left me with all 15 via
> > holes punched thorough the scotch tape and very clean.I checked each
> > one a microscope so I can say all were very clean.
> >
> > Then smudged a blob of nickel print and squeegeed the stuff around the
> > board till was dripping on the other side. While I was doing this the
> > nickel has started to dry already (nothing abnormal yet but this does
> > dry very fast).
> >
> > Vacuum the board on the other side.
> >
> > Then "baked" at around 90C for 30min.
> >
> > Took the board out.. and did some continuity testing. Surprise ..
> > ABSOLUTE FAILURE !!! from 15 holes only 2 were conductive.
> >
> > Now, either I am doing something wrong either the Nikel Print is a
> > advertising hype "by MG Chemichals" :)) . Or my Nikel was bad ... I
> > mean too old.
> >
> > Do you guys have any other idea? I have nickel left so I can try some
> > other technique.
> >
> > C
> >
> >
> > --- In Homebrew_PCBs@yahoogroups.com, Athar Kaludi <ceo_premium@>
> > wrote:
> > >
> > > Calin
> > > Go ahead with Nickel print as trial if you can afford.
> > > Conductive paints work as the word specify. Your purpose will solve,
> > but only for prototyping purpose
> > > What i mean by saying this is that the time required in conducting
> > each hole takes your hours of effort, but you learn a lot more for
> > future.
> > > I am sure that you have that much energy which drives you to ready
> > your prototype. That's the result you are waiting for. Good Luck
> > >
> > > Athar Kaludi
> > > Premium PCB Manufacturing
> > > Pakistan
> > >
> > >
> > > --- On Fri, 7/30/10, morarcalin <morarcalin@> wrote:
> > >
> > > From: morarcalin <morarcalin@>
> > > Subject: [Homebrew_PCBs] Nickel and Silver Print from MG for through
> > hole plating
> > > To: Homebrew_PCBs@yahoogroups.com
> > > Date: Friday, July 30, 2010, 11:41 AM
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > ÃâÃÂ
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > MG Chemicals has two conductive prints that they claim can be
> > used for hole plating. Like I said "they claim" :)) ... so no idea if
> > they really work. That's why I am asking first.
> > >
> > >
> > >
> > > One of them is Nickel Print (around 11$ for 3/4oz) and second is
> > Silver Print (around 35$ for 3/4oz). The difference is in the
> > conductivity, obviously the nickel one being less conductive. MG is
> > saying that they can be used for hole plating.
> > >
> > >
> > >
> > > I am curious if anyone has tried any these two? If it really works
> > for sure will make life a lot easier for DYI-ers like us.
> > >
> > >
> > >
> > > I think using first the nickel one to "pre-plate" and then
> > electroplate or just thin plate with liquid tin to make the soldering
> > work better may do the trick ..... I am not talking doing production
> > work, just to get prototyping easier.
> > >
> > >
> > >
> > > Calin
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
> > ------------------------------------
> >
> > Be sure to visit the group home and check for new Links, Files, and
> > Photos:
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> >
> >
> >
>