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Al Williams' book on PCBs

Discussion in 'Misc Electronics' started by Allan Adler, Oct 8, 2004.

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  1. Allan Adler

    Allan Adler Guest

    I was looking through Al Williams' TAB book on making your own printed
    circuit boards this evening in a bookstore. One of its features is
    a CD containing some free CAD software from SoftCad, which allegedly
    runs under Windows and Linux. I don't know whether it would run on
    my particular machine which has RedHat 7.1. I went to www.softcad.com
    and tried to find a downloadable version of the software to look it over
    and wasn't successful. There does seem to be a demo for download but, if
    I understand the page correctly, it only works for one month. So now I'm
    wondering whether the stuff on the CD is just the demo and will expire if
    you don't purchase the real version.

    Another thing I noticed in the book was the way Williams advises one to use
    a laser printer. He says that you can print onto paper, as usual, or onto
    transparency (possibly better), and then use an iron to transfer the
    artwork to the copper clad board. According to Williams, the toner is
    just a kind of plastic and it will melt if you apply an iron to it
    and thereby transfer the artwork. He says one has to experiment to
    get it right, since paper and printers and irons vary, and he advises
    against using steam irons, even if the steam feature is turned off.

    Has anyone here actually done this?
     
  2. Are you *sure* it was 'SoftCAD' and not 'CADSoft' ?

    http://www.cadsoftusa.com/

    They produce the 'EAGLE' PCB CAD software which is free for 100mm x 80mm
    PCB size, 2 layers and one page of schematics.

    I've run EAGLE on Windows (ME; XP SP1 and SP2) and Linux (Red Hat 9 and
    Fedora Core 2) and it runs very stable; I can recommend it.


    Chris
     
  3. Hi,

    I can attest to the fact that CadSoft Eagle is very stable,
    and all in all a great program. You'll really like it,
    they're very dedicated people. If you're gonna use it I can
    advise you to also immediately join their forum.

    As to the making of PCB's, I just print (using an old
    inkjet printer) on a transparent overhead projector sheet.

    Since my old deskjet isn't very consistent in the ink
    disposal, and the ink tends to be a bit too transparent in
    places, I always print twice and tape the two prints
    together. Try to be very precice when doing this, a good
    magnifier (I use a lens from a junked photo enlarger)
    is indispensable -- you'll also need it to inspect the final
    product, your pcb. If there still are places that are too
    light, I often even manually touch up one of the prints
    with a fine ink drawing pen (0.13mm), using said magnifier
    and a backlight.

    To transfer the print to the photo-pcb board, I use an old
    UV face tanner (4x16Watt I think). Some ballpark figures:
    UV at ca. 10cm above print/pcb, 120s exposure, developing
    (in FeCl) at room temp. some 15-20s; etching ... depends --
    I never bring the etchant to temperature (which should be
    about 50 Celsius I think), so etch at room temperature. I
    just leave it in for about 45 minutes, then go back to it
    and with a tweezer stir it which will result in a clean
    pcb in about 10-15min. The deveoper and etchant you can in
    any good electronics store, at least over here in Holland.
    For the etcher I think you could also use plain sink deblocker
    (caustic soda) in some dillution, but I've never tried it.

    I always drill my 0.8mm holes by hand, using a common home
    drill (actually it's quite a heavy type too). Microtools
    are for whimps ;-)

    I've designed (with Eagle, on Linux btw.), printed, echted
    and soldered complete small pcb's in one day ;-)
    One caveat: this can become addictive!

    Good luck.

    bjd
    bjdouma AT xs4all DOT nl
     
  4. Allan Adler

    Allan Adler Guest

    I've downloaded it.
    I know that is the usual way to do it. The point of my question is
    whether anyone has tried what Al Williams said, i.e. to transfer
    directly from paper or transparency to the copper clad board by
    ironing the paper or transparency on the copper clad board. That
    apparently causes the toner, which serves as a resist, to melt enough
    to attach to the copper clad board instead of to the paper or transparency.
    For this, he insists on using a laser printer.
     
  5. Uwe Bonnes

    Uwe Bonnes Guest

    : I was looking through Al Williams' TAB book on making your own printed
    : circuit boards this evening in a bookstore. One of its features is
    : a CD containing some free CAD software from SoftCad, which allegedly
    : runs under Windows and Linux. I don't know whether it would run on
    : my particular machine which has RedHat 7.1. I went to www.softcad.com

    Try www.cadsoft.de
     

  6. I think I've seen this method discussed on one of the Dutch
    electronics forums. I have no personal experience with it,
    though I'd say it might work. If I were you I'd just try
    it, I mean I'd experiment with fake laser-prints and some
    materials that might resemble the pcb sensitive layer, just
    to see if the transfer occurs at all, and if so, at what
    temperature. Then just try it on a small real pcb.
    That's why I would do.

    Another method is to print the pcb layout directly onto the
    pcb using a flatbed plotter. I obtained two old Mural 8000
    plotters (A0!, slight overkill for the pcb's I make...)
    recently to exactly that end, but haven't given it a try yet
    -- no pens to be found in this vicinity (meaning I'll have
    to construct my own from a fine ink drawing pen, something
    which I haven't come around to yet).

    How do you like Eagle?

    bjd
     
  7. Al Williams

    Al Williams Guest

    The software with the book is the "freeware" version of CadSoft's
    Eagle CAD. It is fully free for personal use and works with boards up
    to a half Eurocard in size and two sides. The software has a great
    library and a pretty strong autorouter along with schematic capture.
    If you want more than 2 sides or bigger boards, you do have to
    upgrade, but the software is well worth the expense and many people
    get along fine with the freeware version.

    The PCB toner method works very well once you find the right
    combination of paper, laser printer, and iron that works for you. One
    thing to note is that you don't iron the pattern onto photoresist. You
    actually put it on the bare copper and the toner IS the resist.

    As someone else said earlier, get a blank copper board and an iron and
    experiment. When it doesn't work, you can always strip the board back
    down with acetone and try again.

    The book covers this method in detail along with photo methods. It
    also covers how to use Eagle (including things like building custom
    components and sending CAM files out for production).


    Regards,

    Al Williams
    http://www.awce.com
     
  8. Allan Adler

    Allan Adler Guest

    I've walked around in wrinkled clothes my entire adult life because
    I don't own an iron. I have a Canon BC02 Bubble Jet printer and no
    laser printer. So it will involve some commitment of resources to
    simply try it. Before doing that, I just wanted to know whether anyone
    else had any experiences to report, other than the author. (Thanks to
    Al Williams for adding his helpful comments to this discussion. I don't
    doubt what he says, I just wanted other points of view.).

    Anyway, I guess there is no alternative to trying it. I can try to get
    an (non-steam) iron, take scrap paper from someone else's laser printer
    and see if I can do any transfers.

    I have very little discretionary capital, so I like to check things out
    carefully before I commit any resources. For example, that is why I merely
    looked through Al Williams' book in the bookstore instead of buying it,
    even though it looked interesting and even though, as books go, it is
    pretty reasonably priced. I know how badly wrong one can go by throwing
    money at a problem instead of investing thought in it.

    Regarding Eagle, although I downloaded it, I haven't had time to experiment
    with it. I've been giving priority to my unfunded mathematical activities
    and they have been fairly intense lately.
     
  9. Allan Adler

    Allan Adler Guest

    Who are "they"? Is the blue sheet different from ordinary transparency?
     
  10. Allan Adler

    Allan Adler Guest

    I did a google search for heat-press and came up with machines for transferring
    designs to t-shirts. They don't look cheap, but I didn't see any prices. I
    looked at the pulsar website and now I understand what a laminator is. They
    don't seem to sell them directly, as nearly as I can tell, but say that they
    usually go for $140, sometimes only $99, at places like Staples. That's good
    to know if one can't get the iron to work. Thanks for the info on this
    and the transfer paper.
     
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