Homebrew PCBs

AFAICS, main problem is hole metalisation.

Couldn't this be achieved by pure force- by running excessive current 
through thin copper wire, which would vaporize and spurt and resolidify 
on the via/pad walls ?

Al it would be needed is CNC with special head- wire feeder ( like the 
one on MIG welder ) that would push the wire through each hole into 
copper plate on the other side...

Branko




Na 20. 07. 2010 01:33, ae5ew je pisal:
>
> Thanks. Charles AE5EW
>
> --- In Homebrew_PCBs@yahoogroups.com 
> <mailto:Homebrew_PCBs%40yahoogroups.com>, Hugh Weinrich <hughaw@...> 
> wrote:
> >
> > As a designer and user PCB's in the 16-20 layer area,
> > I would advise that once you leave the 2-layer design, and move 
> to a 4-layer design;
> > the complications of layer alignment & plated through holes 
> justifies paying the 'professionals' their due.
> > Â
> > Four layer PCB's can be aquired for as little as 100$ for four 
> 3.8in x 2.5in boards.
> > see  http://www.expresspcb.com/ExpressPCBHtm/Specs.htm
> >
> >   As for How is a PCB Made ? see: 
> Â www.instct.org/secure/downloads/HowIsAPCBMadeICT_V5.pdf
> > slides 1-31 give a detailed explaniton of how this is done 
> professionally
> > Â
> > Â
> > Â HughAW
> >
> > --- On Mon, 7/19/10, ae5ew <ae5ew.us@...> wrote:
> >
> >
> > From: ae5ew <ae5ew.us@...>
> > Subject: [Homebrew_PCBs] Re: Multi-Layer PCBs
> > To: Homebrew_PCBs@yahoogroups.com 
> <mailto:Homebrew_PCBs%40yahoogroups.com>
> > Date: Monday, July 19, 2010, 5:17 AM
> >
> >
> > Â
> >
> >
> >
> > I'm not considering doing such a thing. Curious to understand how a 
> reliable connection is assured in such a PCB. My experience as a 
> technician has exposed me to some through-hole contacts on 2-layer 
> PCBs can sometimes be a problem. Some soldering can usually correct 
> that. Vias must be reliable for the PCB to be of use. Charles AE5EW
> >
> > --- In Homebrew_PCBs@yahoogroups.com 
> <mailto:Homebrew_PCBs%40yahoogroups.com>, Dylan Smith <dyls@> wrote:
> > >
> > > On Mon, Jul 19, 2010 at 11:56:48AM -0000, ae5ew wrote:
> > > > Ok. I admit I'm ignorant when it comes to this subject. How is 
> an IC
> > > > lead connected to say layer 8 on a 16 layer PCB.
> > >
> > > Via a via :-)
> > >
> > > I presume you're talking about through hole components, in which case
> > > the via that forms the hole the IC pin goes through. For SMD, a 
> via must
> > > be drilled.
> > >
> > > On a commercially made board this via is through plated and makes
> > > contact with the tracks in the inner layer that you have connected to
> > > it. Some brave souls homebrew 4 layer boards, there are various
> > > strategies for making contact to inner layers in absence of 
> through hole
> > > plating (I presume the hole on the top layer is a little larger so 
> that
> > > a wire can be soldered to both the inner layer and outer layer to 
> make
> > > the connection).
> > >
> > > For me a multi layer board normally means fine pitch SMD (already
> > > increases the difficulty level in home making a PCB) as well as multi
> > > layers, so I just use a commercial board house since two lots of
> > > difficult tasks goes from being a fun challenge to frustration! 
> (If push
> > > came to shove, I'd consider a 4 layer board where the inner layers 
> were
> > > power and ground planes).
> > >
> >
> >
> >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
> 



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