>
> A simpler/cheaper alternative to electroless prepping of the holes, that seems to work quite well, is to use graphite laden india ink. Add about 10 grams of graphite to a one ounce bottle of india ink and mix well. Then, spread the ink thoroughly on one side of the board. Use a shop-vac to suck excess ink out from the bottom side. Then, flip the board and repeat. Wipe away the excess ink from the board with a paper towel dampened with acetone. Allow to air dry, or use a heat gun, hair dryer, or oven to thoroughly dry the board. The idea is that the electroplated copper will adhere to the graphite coating the hole. This method works pretty well.
>
> Think and Tinker carries sells a special ink for this process as well. Or, if you happen to have some of the circuit writer silver ink, it works, as well. I just happen to have a 4 oz. bottle of it from an earlier experiment to see if I could do thru-hole plating without electroplating. Turns out that it doesn't work reliably.
>
>
>
> --- In Homebrew_PCBs@yahoogroups.com, Donald H Locker <dhlocker@> wrote:
> >
> > Took me a while to find it, so I'm posting a link to the directory it's in.
> > <http://tech.groups.yahoo.com/group/Homebrew_PCBs/files/through%20hole%20plating/>
> >
> > Thanks, Dave.
> > Donald.
> > --
> > *Plain Text* email -- it's an accessibility issue
> > () no proprietary attachments; no html mail
> > /\ ascii ribbon campaign - <www.asciiribbon.org>
> >
> > ----- Original Message -----
> > > From: "Dave M" <dgminala@>
> > > To: "Yahoo Homebrew_PCB" <Homebrew_PCBs@yahoogroups.com>
> > > Sent: Saturday, February 25, 2012 11:56:09 AM
> > > Subject: [Homebrew_PCBs] PTH Process
> > > I recently ran across a booklet that I had bought (online) a number of
> > > years
> > > ago that describes, in pretty good detail, a process for making PCBs
> > > with
> > > plated through holes. The process it describes uses an electroless
> > > copper
> > > plating process to get copper onto the walls of the holes, then
> > > electroplating copper to deposit the final layer of copper, and
> > > finally, the
> > > photoresist application, developing and etching The photoresist and
> > > developing chemicals that the author specifies in the booklet are
> > > rather
> > > expensive.
> > > I have looked high and low on the web for any reference to this
> > > booklet,
> > > without success. The booklet contains no copyright info, not even the
> > > author's name. I've scanned the document and am willing to make it
> > > available to the group. I'd like to get set up to try this process if
> > > someone could recommend some alternative photo chemicals (much less
> > > expensive) to use in the process. I can see that this process could
> > > indeed
> > > produce some high quality multilayer boards, but for a hobbyist, the
> > > expense
> > > is just too high using the photo chemicals suggested in the document.
> > > The original document specified Kepro chemicals, but I found that
> > > Kepro was
> > > transformed into D&L Products, Inc (Dalpro). I updated the text to
> > > reflect
> > > current contact info.
> > >
> > > I'll post the document to the files area, and would love to hear
> > > comments
> > > (pro and con). The document is titled "The PTH Process For
> > > Homebrewers",
> > > and is a PDF document.
> > >
> > > Dave M
> > > A woman has the last word in any argument. Anything a man says after
> > > that is
> > > the beginning of a new argument.
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > Be sure to visit the group home and check for new Links, Files, and
> > > Photos:
> > > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
> > >
> > >
> > >
> >
>