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Subject: Re: Resolution of the toner transfer method

From: "wheedal99" <wheedal@...>
Date: 2003-12-22

--- In Homebrew_PCBs@yahoogroups.com, "Deepinder Singh"
> I was thinking of switching over to the toner transfer method but
was
> curious what is the resolution that people achieve with this
method -
> i.e. is it suitable for smt. I've heard that the toner spreads a bit
> when heated but not sure how much.

I normally use 12mil trace-6mil clearance. You can do this without
even thinking twice about it and not be very careful during the whole
process. I've done 6-6 with good results too, but you do need to be
quite a bit more careful. I've had difficulty with these, not
manufacturing the board, but burning the traces off later (the glue
releases the copper under too much heat). I have noticed that the
FR4 1oz clad seems more robust than the paper phenol in this regard --
anyone else see this? <-- That may be more a function of board stock
brands. Anyway if a PCB layout needs higher densities, I've tended
to lower the clearance value rather than the trace. That said 8-6
works pretty well, although you do need to be more careful and put
some toner nearby (ground planes, other signals ) --this tends to
help keep the paper from pulling off that one lone trace.

I haven't seen too much spreading with the laminator. I keep my
printer set to normal rather than dark --if you get the right amount
of heat/pressure/paper carrier, all the toner will get tranfered.