• [VE7SL] e-Bay PCB Thermal Transfer Paper

    From VE7SL via rec.radio.amateur.moderat@21:1/5 to All on Tue Sep 28 15:20:03 2021
    XPost: rec.radio.amateur.moderated

    VE7SL - Steve - Amateur Radio Blog

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    e-Bay PCB Thermal Transfer Paper

    Posted: 27 Sep 2021 05:02 PM PDT http://ve7sl.blogspot.com/2014/08/e-bay-pcb-thermal-transfer-paper.html

    This past weekend I had the first opportunity to try my e-Bay purchased
    thermal transfer paper. It was to be used in my iron-on PCB work as a
    hopeful improvement over what I had been using...just ordinary printer
    paper. Supposedly the shiny photo quality papers were proving to be good performers but are expensive. Some have reported good results with glossy magazine paper but my one experience with that was not a pleasant one. Unknowingly, when I had removed the magazine page, a small amount of the sticky adhesive used in the binding process was still on the sheet.
    Running it through the printer caused it to melt and smear some of the
    laser cartridge's toner and for the next several weeks, any printing I did
    had a slight black streak along one edge...doh!

    My new paper from China (free shipping!) was pretty inexpensive and if it offered even a slight improvement, would be well worthwhile. This first
    use of the paper would be a circuit board for my earlier test-bed GW3UEP
    630m transmitter. I had finished designing a PC pattern for it, using MS Paint, and was anxious to see the results.

    
    Courtesy: http://www.gw3uep.ukfsn.org/I decided to use a small separate
    board for the crystal oscillator-divider so at a later time I could more easily swap it out for a DDS driver. Using a separate board would allow
    me to do that without disturbing the rest of the transmitter.



    I know that a lot of folks turn up their noses at MS Paint but I have
    always found it to be a very versatile piece of software and have used it
    for making PC layouts for many years. I also use it for drawing all of the schematics appearing on my website.

    After printing the pattern (printer set for maximum resolution and darkest print) and ironing-on the pattern , I allowed the board to cool for
    several minutes before immersing it, along with the now firmly attached
    yellow paper, into cold water. The first thing I noticed was how easily
    the paper came away from the board. It actually 'un-peeled', much like a
    good quality price tag sticker...you know.... the ones that don't take
    forever and come off in tiny bits and pieces. It peeled off smoothly with
    no paper residue left on the board. This was a huge improvement already.
    There were just a few traces of toner left on the paper as almost all had
    been transferred to the board.

    Once dried, a close examination revealed that I had pressed a little too
    hard with the iron and there was some evidence of 'squeeze-out' along the edges of some lines. I also found one or two very small thinner areas that probably required going over with a permanent-ink black marker pen just
    to make sure that those spots did not get etched. Over all I was extremely pleased with the paper and will be using it from now on.

    Another recent change in my PC etching regime has been a switch from the
    old Ferric Chloride standby to a combination of Hydrogen Peroxide and
    Muriatic acid. Not only does it seem to etch more cleanly (no
    undercutting) but it also etches very quickly and without any solution
    warming needed. This board was completely etched in just over 4 minutes.


    The chemicals used in this method are inexpensive and are readily
    available at the drugstore and at the hardware store. There are numerous web-descriptions of this particular etching process but this site seems to cover the basics nicely.


    The completed board turned out as shown here:


    The CD4060 not only functions as a crystal oscillator but also as a
    versatile frequency divider. As well as fundamental frequency output, ten different 'divide-by' functions are available depending in which output
    pin is chosen. These range from divide-by 16,384 to divide-by 16. This circuit uses the latter, dividing the 7.6 MHz crystal down to 475 kHz at
    pin 7.


    In summary, I can highly recommend the e-Bay yellow thermal transfer paper
    when used for this method of making PCB's and is much cheaper than buying photo-quality printing paper.

    --- SoupGate-Win32 v1.05
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