Andy N1YEW wrote:
>
> why would my traces get erased on a home etched board?  i use fecl3 the radioshack stuff.


Bad etch pens, bad PCB preperation, warming the etchant too much, too
long in the solution, too much sloshing around, too many air bubbles,
etchant too strong....

This is a simple outline of what I do.


Create a mirror image of the PCB design.
Cut the PCB to size.
Polish it with "Brasso" and wipe with turpentine.
Tape the design on the PCB and use it as a drill guide.
Wash the PCB in detergent untill the water does not "bead" on the
surface.
Draw the artwork using the predrilled holes as a guide.
I use a Dalo pen for traces. I have two pens. One with a dull edge that
I use to 'dab' pads onto holes and draw thick traces, and one with a
sharp edge that I keep specially for thin traces.

I use Ferric Chloride for the etchant because it is cheap and has a
l-o-n-g shelf life. My old etchant has nice bright green copper crystals
growing out the sludge on the tank bottom. It's been there for years and
still works fine even on cold days. (12'C and the like)

I don't use bubble etchers, heaters and the like. I place insulated
telephone wire standoffs on each PCB corner and place the PCB track side
down in the etchant. Gavity does the work, the etch process is quick,
the traces have a sharp edge and the etchant stays clean. Just go off
and have a cup of coffee, beer or whatever, and when you come back the
board will be ready.

The board is then rinsed under cold water and the etch pen removed with
turpentine. To protect the bright finish, and if I want to use the board
for a long time, I spray it with Electrolube clear laquer.

http://www.bubblesoftonline.com/projects/pcb.html

--
Best regards

Tony

mICros
http://www.bubblesoftonline.com
mailto:sales@bubblesoftonline.com

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