--- In
Homebrew_PCBs@yahoogroups.com, Kim Lux <lux@d...> wrote:
>
> I am about to make some printed circuit boards using a laser
printer,
> the Pulsar transfer film and an H200 laminator. Do I need to use
toner
> reactive film or will the toner itself resist the etchant ?
>
> Thanks
>
>
>
>
> --
> Kim Lux (Mr.) Diesel Research Inc
The toner Reactive file merely puts a harder surface in the top of
the toner image. It does not fill in holes in the toner nor does it
fill any "jaggies" in trace lines or pads.
Its main purpose is to provide a harder, more impervious cover for
the toner. This is important if you are using Pulsar's
recommended "direct rub" method of FeCl etching (which I use).
The "direct rub" method relies on use of a soft sponge or brush to
wipe the etchant across the board. Small amounts of etchant are used
at room temp and wiped across the board. This speeds the etching
process by constantly resupplying fresh FeCl to the copper surface
while removing the copper-saturated etchant. Without the TRF
overcoat, some of the toner will be rubbed off, exposing copper that
you do not want removed.
If you are not using the "direct rub" method but are using an etching
tank, I do not believe that the TRF is needed, but may enhance
quality of the board.
I also use the aluminum colored TRF to do the legend side of the
board. I have no problems getting a good component legend with the
toner transfer and finishing it with the aluminum TRF. I do
encounter some minor problems when transferring a legend when a
legend item is too close to a track or pad on a double-side board.
The difference in the height of the copper and the board will cause a
small skip in the toner due to this surface irregularity.
The TRF coated legend is surprisingly scratch resistant. I transfer
the legend prior to drilling. The legend side is face down on my
drill press and after all of the positioning, sliding and drilling,
the legend appears unaffected.
I use these techniques to make single/double sided boards from 3"x5"
to 9"x6". I do all thru-hole boards, so I make no representations
regarding the efficacy of these techniques for SMD work.
Hope this helps.
Regards,
Rusty Turley