Homebrew PCBs

On Wed, 10 Jan 2007 17:50:01 +0100, DB Express <dbxprss@...> wrote:

> I just etched my PS board this morning.  Not too bad for a first try:
> http://members.lsol.net/gop4evr/unlinked/psboard.jpg

Not bad at all! I wish my first try would have had any traces on it ;-)

> I used homebrew etchant (2:1 hydrogen peroxide/muriatic acid).  At  
> $2.69/gallon for the muriatic acid and 69 cents/quart for hydrogen  
> peroxide, this sure beats paying $6/pint for the FeCl.  It works well,  
> but has some odor.  I used it outside just as an extra precaution.

Now you should look into care and feeding of this etchant as CuCl. You can  
use it forever only replenishing small amounts of HCl and regenerating  
with H2O2. You will want to get H2O2 in high concentration (above 20%), or  
you'll add too much water.
How to maintain CuCl can be found in the links section, although many  
guides make it way too complicated.
If your etchant was fuming or bubbling you probably had a much too high  
concentration of one or both of the chemicals. CuCl will not cause any  
smell, or cause any rust to nearby parts, if the concentrations are within  
reason and it is covered when not in use.

> Those who were following this project on E101 will notice that I rotated  
> the regs 90 degrees (to make room for the heat sinks and give better  
> airflow).  It was suggested that I add some filled areas for heat  
> dissipation, and I probably went overboard.  I figured that since I had  
> the room to work with, the wider traces couldn't hurt anything and would  
> also give me some fudge room in case of etching voids.  I am pleased  
> with the result, which was made possible by the information I gleaned  
> from this group and related web sites.  Thanks guys.
> Nels

Also, by using a larger copper area you saved etchant.

ST