Overview:
Review of a water-soluble printer-compatible paper for use in
toner transfer based PCB creation
Product:
WashAway Foundation Paper
Manufacturer/Distributor:
W.H. Collins, Inc - www.dritz.com
Bought Online From:
http://store01.prostores.com/servlet/fivesistersquiltshop/Detail?no=563Price:
USD $8.95 for pack of 10 letter-size sheets
Review:
After seeing mention of this paper product on this mailing list,
I decided to give it a try.
My online order to www.fivesistersquiltshop.com was processed
very quickly, and the product arrived promptly - especially
considering it was shipped from the USA to New Zealand.
I printed out a small (45mm x 30mm) PCB artwork onto a pilot
sheet, then cut a strip of the WashAway paper, placing it on top
of the artwork on the pilot sheet with sticky tape on the
leading edge - the same technique used by myself and some others
when using glossy inkjet card.
The artwork printed faultlessly onto the WashAway paper using my
HP Color Laserjet 2550L.
After four passes through the laminator, the toner adhered very
firmly to the copper on the board. (In retrospect, I should have
given it 6-8 passes - see below).
With previous boards at this point, I had needed to soak the
board+card, peel off gently, then rub with fingers, worrying
about damaging fine traces. This step, which took up to 15
minutes, was always a risky and unenjoyable point of the
procedure.
But this time, with the WashAway paper, I just put the board
under running water, and the paper disappeared completely within
5 seconds. No need to rub, and no need to risk damaging toner
deposits. All that remained was jet black toner, with good
quality artwork reproduction.
Following this, I etched the board in FeCl as normal, and ended
up with a near-faultless board. The only fault was a small break
in one trace, which proved quick and easy to solder-bridge. I
would like to try more boards, with more passes through the
laminator - 6-8 instead of 4, and suspect this will give me a
zero-defect board.
Verdict:
On the positive side, the price is way less than press-n-peel,
and comparable with gloss card stock. This paper saves up to 15
minutes in the board creation process, and eliminates a
significant source of defects.
On the negative side, there was minor distortion in the artwork
on the finished board, comparable to that which happens when
using thin glossy 'time magazine' paper (which is why I've
tended to use gloss card stock).
It's possible that if I put a sheet of thin gloss card over the
WashAway paper when feeding into the laminator, this distortion
could be reduced or eliminated. I'm using PDIP and other
through-hole components - the minor distortion was no major
problem, but if I'd been using fine SMD traces, it could have
given me much trouble and forced me to revert to glossy inkjet
card.
However, I'm happy with the overall result, and grateful for the
time and labour it saves. I'll be leaning towards use of this
paper from now on, especially for simpler boards, and hope the
retailer keeps up their stock.
Conclusion:
I give this product 4 out of 5 stars.
Definitely worth a try, and well worth having in one's home PCB
manufacture toolkit.
For myself, I'll experiment with the thermal transfer stage and
see if I can reduce artwork distortion. Maybe others on this
list might like to do similar and share their results.
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Cheers
David