Homebrew PCBs

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=563

Price:

        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.

--------------

Cheers
David