Homebrew PCBs

Neil,

This process sounds very interesting using a laser.  I had planned to 
try something similar using the machine I am building but a "Scratch 
tool" as opposed to a laser.  I always suspected that isolation 
milling would be very dependant on two things:
1) a tool that will cut good, without burrs
2) a spindle with high enough speed and zero - runout at the tool

To avoid those problems completely, I was planning on using a spring-
loaded scratch awl type tool.  Then, just run the CNC program path 
for the isolation milling to scratch away the resist.  

For the resist, I was thinking about using Dykem which is a lacquer 
based product used in machine shops as a layout colorant.  It will 
stick to all metals, drys fast, and works very good with 
the "Scratch" removal process as that is what it is designed to do. 
You can purchase it in spray cans, brush-bottles, or little 
dispensers with a pad applicator.  I figured I would use the spray 
can version as that should give the most consistant coating.

Now your idea of a laser would take away another mechanical aspect of 
this process which is appealing, but I know enough about lasers and 
myself to know that I will probably hurt myself with one ;-)

Can you tell me where I might find a laser that is suitable for 
this?  Even with the risks involved, I would like to consider it.

Chris



--- In Homebrew_PCBs@yahoogroups.com, "Neil Baylis" <neil.baylis@...> 
wrote:
>
> I don't know what this is called, but I assume there are folks 
making PCBs
> this way:
> 
> 1: Coat the copper board with a thin film of lacquer
> 2: Use a laser to selectively burn away the lacquer leaving bare 
copper
> 3: Etch
> 
> Can anyone point me to info about this technique, especially what 
kind of
> lacquer to use, and an idea of how much laser power would be 
needed. I've
> noticed that I can get dark materials to smoke with about 100mW of 
laser
> power. I guess that with the right lacquer, this technique could be 
done
> with about 1 Watt laser power, which is easy to obtain.
> 
> Obviously, the laser would have to be mounted on some kind of x/y 
plotter
> device.
> 
> 
> [Non-text portions of this message have been removed]
>