Homebrew PCBs

Everything old is new again.... ;')

Check out this thread:
http://tech.groups.yahoo.com/group/Homebrew_PCBs/message/259

Metal layout fluid and specifically Dykem mentioned here:
http://tech.groups.yahoo.com/group/Homebrew_PCBs/message/261

I did some testing with a different brand of layout spray and found
that if the layout fluid is not fully dry, it tears. A day or two to
dry or short bake and it makes nice lines, not as nice as photoetching
but what is?

Scratch N Etch in Files:
<http://tech.groups.yahoo.com/group/Homebrew_PCBs/files/Scratch_And_Etch/>

I emptied out an HP plotter pen. Put a carbide tipped scratch tip in
it, filled the top with lead shot and glued it in for weight. Played
with it in a small HP plotter.

Someone tested the etched width of a line. I don't recall any
parameters of the test other than it being an HP plotter with a
carbide tipped head and Dykem marking fluid. I think it was 0.006"
from one pass, 0.011" from two passes (no offset).

Steve Greenfield

--- In Homebrew_PCBs@yahoogroups.com, "lcdpublishing"
<lcdpublishing@...> wrote:
>
> 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.