AVR-Chat

> 
> --- "Chuck Hackett" <egroupscdh@W...> wrote:
> > Does anyone know of any layout tools available on the net that
> > might be suitable.
> 

Another one is CirCad.  It's at http://www.holophase.com/

The free program demo won't produce Gerber or Postscript files but it will 
allow you to print your pattern.  I've used a screen capture program to 
take the pattern displayed on the screen and convert it to a graphics file 
which I can turn into a negative with a graphics program.

By the way, I've described this on several ham radio groups I'm on, but I 
have a routine for making pc boards that has been successful for me for 
years.  I started out making negative pc board patterns with Kodalith in 
the darkroom, but lately I've been designing the patterns with Coreldraw 
or making a negative from an image file and printing on a transparency 
sheet on a laser printer.  Depending on the printer and the transparency 
film used, you may have to touch up the dark areas with a marker. I 
prepare a board for coating with Datak ER-71 photoresist (this is a 
negative-acting resist similar if not identical to the old Kodak KPR) and 
coat it according to the instructions. I let it dry at least overnight.  
Then I put the negative over the pc board in a contact printer and expose 
to bright sunlight for about 2 - 2 1/2 minutes.  I develop in Datak ER-8 
developer for about a minute and inspect the board.  Sometimes a bit of 
touch-up needs to be done on the photoresisit with a fine-tipped marker. I 
then etch the board.

If you have a very detailed pc board pattern with fine lines, make the 
transparency "flipped" so it is correct when the side that actually has 
toner is in contact with the pc board when you expose it.  I've been 
making boards for microwave circuits up to 10 GHz with this method with 
excellent results.  I'm about to try it with some 24 GHz circuits.

Zack