Homebrew PCBs

As an addendum, it will also print on a sheet of thin aluminum. I 
just ran a piece of  10 mil aluminum flashing through the printer - 
it printed, but the lines were a bit wavy, probably due to the coarse 
surface of this aluminum.
Mark

At 08:30 AM 3/14/2009, you wrote:
>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
>
>
>
>------------------------------------
>
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