--- In
Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
>
> two things,
>
> first, the component legend is easily freed from paper residue by
abrasive
> pad (meant for cleaning copper tubing to solder), which i use for
cleaning
> the copper too. then use a paper towel (use shop-grade recycled
material
> which is pretty abrasive) and polish it to a shine with a few rubs.
> (could use polishing wheel too.)
> Gives a perfect shiny component legend, similar looking to black
> silkscreen (actually much better ;-) )
> (Note: previously i used abrasive kitchen cleaner and a lot more
effort to
> polish it and remove the residue).
I do a hot peel - just pull the paper off when its still hot. Works
quite well and its a lot faster. It doesn't leave quite as much toner
but its very legible and no cleaning is needed.
>
> second, alignment of double sided boards or copper artwork bottom /
> component legend top in one go:
> I realised the problem with aligning double-sided things was that the
> paper shifted when fed into the
> fuser no matter how hard i tried to glue/tape it etc.
> I needed a glue to stick the paper directly to the PCB. The obvious
is to
> use toner!
> i just make a 5mm broad strip of solid toner above the artwork, and
stick
> it on with a clothes iron.
> Works great. only iron the strip to prevent any bad effects on the
other
> artwork. Maybe the artwork
> itself could be used to stick it with the iron, and the laminator
only to
> ensure a uniform adhesion.
> The 5mm strip is not a problem for me because i use it to clamp the
board
> during etch.
I've not had any problem with tacking the artwork (vs a special toner
strip) before feeding through the laminator. But, I don't bother
with that anymore - I use a carrier for the board/paper assembly. I
fold a sheet of children's "construction paper", put the assembly
inside and and feed it through the laminator. I've had good to great
alignment on about 30 boards I've done (yeah, i really should have
sent them out...). Its my guess that the paper to paper contact slips
more easily than paper to copper does. Prior to using a carrier or
tacking I was getting 5-10 mils of mis-registration. Now I think I'm
getting around 2-3 mils or less which is better than the accuracy of
my drilling.