Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

For anyone interested, there is absolutely no reason that laser
printers cannot directly deposit toner on pcb boards. The practical
problems are the fuser and the paper path. As a proof of concept, I
took a Brother HL2140 laser printer that has a manual feed for
thicker media and fed a sheet of thin (8 mil) laminate through the
printer. Nothing printed.

I then removed the fuser, using appropriate resistors to simulate the
correct fuser temperature and thereby fool the printer controller
into thinking the fuser was still there. I ran the same test, and
sure enough, it printed perfectly! Of course, the toner was only held
to the board by electrostatic attraction, but I then put the board
into my trusty toaster oven and "fused" it.

There are other practical problems, but these can be overcome with a
little bit of work. A small mcu will be needed to simulate some of
the feed sensors and the paper path will have to be changed, but my
experiments show that these are (relatively) easily done.

I have used a datalogger to check the function of the three main
sensors - paper feed, start print (rear register) and eject - and can
simulate all of these and I have actually run the printer using an
mcu instead of the sensors. However, the real problem is that the
machine is not rugged enough to handle a lot of manipulation - the
connectors break down easily and you end up with error lights that
you have no idea how to fix, a tiny slip that causes a momentary
short will sometimes blow a board, etc.

If anyone is interested in more details, I am happy to share.

Mark