Homebrew PCBs

I discovered about 15 years ago a technique which has worked 
flawlessly for me and etches in about 5 min.:  Float the board, 
copperside down, on the etchant.  The surface tension of the FeCL3 
easily supports the board.  As the copper disolves into the FeCL3 
the Fe, which is heavier, drops to the bottom of the container.  
This leaves fresh etchant on the surface of the board all the time.  
Best of all, NO AGITATION is required!  On FR4, you can see the 
progress just fine through the board.  Heating (luke warm) the FeCL3 
first does help, but we all know that.  Just drop the board on to 
the etchant, walk away for 5 minutes, and the board is done.  Give 
it a try next time.

Jim 

--- In Homebrew_PCBs@yahoogroups.com, Kamal Shankar 
<kbshankar2000@...> wrote:
>
> Guys
> 
> I have been facing a problem in getting 15x10 sq.cm
> single side boards etched under 5 mins. I use
> commercial grade FeCl3 and heat up the water to
> boiling point. Then add it in a plastic tray having
> FeCl3 and after mixing thoroughly, drop the boards.
> 
> I keep enough solution in the tray to just have the
> board below the surface at an uniform 4mm.
> 
> But I have to heating mechanism due to which the
> solution cools down after 2 mins. I also constantly,
> manually rock the tray a little to remove "dust"
> formed on the boards.
> 
> Currently this is taking me more than 20 mins for the
> etching to complete !
> 
> I think I am wasting too much time behind an
> ineffective/inefficient etching process - the
> equipments I am using ssem to be far from optimal..
> 
> Any tips on ultrafast (sub 10 mins) etching ?
> 
> KamalS
> 
> 
> 
>        
> 
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