Homebrew PCBs

Hi Wayne,

It was tda7000 who first mentioned this project.  I responded with a new
subject in the hope that this would make it easier to find in the archives.

I think a closely spaced line of discrete SMD UV LEDs could be used,
with Riston or similar negative photo resist (exposure makes it
polymerize, resist development and so protect the copper).  The light
from the LED array could be focused by an old SLR camera lens or similar
into a row of points on the PCB.  Then, the whole array and lens
arrangement could be scanned X and Y by a plotter mechanism or a
purpose-built X-Y CNC table.  The more LEDs in the array the fewer scans
would be required.  There would be some finicky driving and alignment
problems to solve.

tda7000 also mentioned another project.  A single UV LED, focused on the
board, driven by a plotter as in the 6th message at:
http://4hv.org/e107_plugins/forum/forum_viewtopic.php?66471 and
http://www.youtube.com/watch?gl=DE&feature=channel_page&hl=de&v=JG5qUhn9sSM
seems to me a lot easier.  It would be relatively slow, but that should
not be a problem for must of us folks.  This is simple, since the LED is
driven by the signal which used to drive the pen solenoid.

I think some PCB programs still have a plotter driver.  I have just
bought the 500 pin limit Starter Kit of the Proteus ISIS Schematic and
ARES PCB system (USD$249, UKP150, E200):

  http://www.labcenter.com/products/pcb_overview.cfm	

The ARES PCB system has a plotter driver, but I am yet to design a
board, so I can't be sure what it does.

  - Robin


> Robin, thanks for providing the links for an outstanding Laser
> Direct Imaging project. Does anyone know of any similar projects?
> 
> Wayne