Homebrew PCBs

> > Or find an enchant that works at low temperatures (and only 
> attacks the
> > copper, of course).  It would make a change to toss 
> something in the  
> > fridge
> > rather than into a tub of warm water.
> > This would be something a Peltier module can help with.  It 
> can keep the  
> > PCB
> > cool, and be cheap and not take up much space while doing it.
> > Tony
> 
> 
> Only that usually chemical reactions speed up with increasing 
> temperature.
> Therefore i doubt such an etchant exists.


Probably.  I doubt FeCl would work in the fridge, or it'd take a week to
work.

Anyway, 'high' temperature alloys exist, like Woods metal.  It melts at
around 50C, so that would work.  Only a couple of trivial problems remain,
like is Woods metal attacked by etchant, and how does one pump molten metal
onto a PCB?

Hmm, PCB sits on a Peltier, cooled enough to avoid condensation.  Molten
metal held in a syringe, forced out by plunger, retract plunger slightly to
stop.  Same as solder paste.  If you test conductivity between the PCB & the
shrine, you can see when the track start to get laid.  How to do wider
tracks?

PCB is etched, then placed in hot water to remove Woods metal.  Metal is
reused.

Right then, "who wants to try it", he says, thus showing an idea is worth
zero unless you can show it works.

Tony