Homebrew PCBs

I would like to know which of the PCB programs allow you to print a 
solder mask. I am using Eagle and it only shows you the area that will 
not get any resist. I want it to show the resist as it will be applied 
so I will be able to print it on the board. I think I saw pictures of 
one somewhere (Stephan?) (Volkan?). The silk screen is no problem as 
the programs shows it as it will be printed. If I can get the solder 
mask on it will make soldering so much easier.

On Sat, 03 Feb 2007 05:40:36 +0100, wnnelson0 <wnnelson@...>  
wrote:

> I would like to know which of the PCB programs allow you to print a
> solder mask. I am using Eagle and it only shows you the area that will
> not get any resist. I want it to show the resist as it will be applied
> so I will be able to print it on the board. I think I saw pictures of
> one somewhere (Stephan?) (Volkan?). The silk screen is no problem as
> the programs shows it as it will be printed. If I can get the solder
> mask on it will make soldering so much easier.


You simply need to make a negative of the image you see.

ST

OK I kinda figured that, but I don't know how to do that in Eagle. I have tried but I can't see
the way through the transistors. In the Eagle forum it was suggested to output a cam file and then
use that but that escaped me also. I will try again. I don't want to use another software program
to reverse it and then go through resize and alignment problems.

Bill

"wnnelson0" <wnnelson@...> writes:
> I would like to know which of the PCB programs allow you to print a 
> solder mask.

With PCB, just check the "ps-invert" option, if you're printing to
"paper".  It's designed to support positive- and negative-sensitive
photomasks, but should work for you also.

First of all congratulations, your results are really
excellent and thanks for sharing. I have faced  a
similar negative image generation problem. What I do
is, 
1)generating negative image by using qms-ps 2200
Postcript printer driver on windows  (there is an
option for negative image) and as an output port,
`file output` is selected. Using Ghostview, convert it
to BMP and then open it by Paintbrush to remove
unnecessary black image outside of the solder mask.
The image is ready to print.
2)To align the image tray,  cover pcb with a sheet of
OHP transparency and make a dummy print on it. Try to
align pcb to the image on transparency sheet. After
alignment, print image on PCB, you need to do it
several times to get thicker solder mask. 
Another option is to add a center line marker (like a
big cross). Always align your pcb images to the cross
markers. 
I have prepared a tray template for this purpose and
before printing I am pasting pcb image on this tray
template and then start  printing.

Volkan
--- William Nelson <wnnelson@...> wrote:

> OK I kinda figured that, but I don't know how to do
> that in Eagle. I have tried but I can't see
> the way through the transistors. In the Eagle forum
> it was suggested to output a cam file and then
> use that but that escaped me also. I will try again.
> I don't want to use another software program
> to reverse it and then go through resize and
> alignment problems.
> 
> Bill 
> 
>

I beleive I may have stumbled onto a way to use Eagle for the mask. I finally found out how to do
copper pours for the ground plane (this will save a lot of etching but use more ink). I use this
same feature but only have the pads showing before the pour. I can isolate each pad at whatever
distance I want. I can show that layer as black and then do a print and it should align perfectly.
I have not done it yet but the theroy is there.

Bill

>In the Eagle forum it was suggested to output a
>cam file and then use that but that escaped me also

You need to create Gerber .stc/.sts files then use a Gerber viewer to 
print.

st(c)=solder stop mask (c)omponent side
st(s)=solder stop mask (s)older side

--- In Homebrew_PCBs@yahoogroups.com, William Nelson <wnnelson@...> 
wrote:
>

Yep I did that but I think that I figured it out using Eagle alone. Thanks