I have been using the toner methode of creating etch resist on copper PCBs for
many years. Until recently I havn't had consistant results. This is an example of
using the same toner transfer to create the "silkscreen" or assembly on the
component side. The missalignment is visable, ten to fifteen mil. This is related
to making double sided boards, getting the pads to line up within a few mil so
the via holes don't waste copper. The process uses a common toaster oven for
heating the pcb and toner printed paper. A pair of aluminium plates bolted around
the periphery keep the printed circuit paper hard against the PCB. Etching is now
done in feric cloride in a glass pan, rocked by a slow motor and cam. There are
many possible improvements in this but it works well enough for the moment.
Next step is a controlled oven for reflow as well as fusing toner to copper. This
is my first post here. The board is a signal conditioner for a hall based throttle
for a marine electric inboard motor controller. Joe was the customer.