Re: Prototyping PCBs and Ipso Facto / ACE 1802 PCBs... #Serial #IpsoFacto #Electronics

Lee Hart

ajparent1/kb1gmx wrote:

Hi Allison,

Thanks for some extra tips for the art of PCB artwork. Lots of ways! Gee, I wonder what Leonardo DaVinci would have used? :-)

There are several photo transfer. The one I used required a special very
yellow looking florescent tube
I never ran across that one. I used a resist that needed a UV light. I applied it with a little spray gun. It was tricky to apply because it was clear; you couldn't see how well the PCB was coated.

For front panels that wanted a distinctive look resist on aluminum then
etch it. There are several materials that work, ferric chloride was good.
Interesting. I never tried ferric chloride on aluminum. I used lye instead, usually with a reverse plating current to etch deeper.

The copier/toner was terrible but it helped me once to get something
however poor.
Yeah, they looked bad. Fuzzy edges from the leftover fibers.

There's a newer toner method I haven't tried; but it sounds promising. Use a toner that disolves in acetone. Mix 8 parts denatured alcohol with 3 parts acetone. This softens the toner to make it sticky, but does not quite disolve it off the paper. Wet the cleaned PCB with the mix. Place the paper+toner on top, so it is adhered just by the liquid. Give it 5-10 seconds to disolve the toner, then apply pressure to squeeze out the mix. Then place in water, and after a few minutes, peel the paper off the PCB+toner. The toner should have all transferred to the PCB; none on the paper. Now you can etch the board!

Good to know wider copper tape is available. I only found it up to 2" at "tape jungle" online. The narrower stuff is easy to get; it's used for security systems (on windows), making "flat" wiring, and various RF shielding purposes.

Here's yet another novel technique. CMOS has essentially zero input current. That means the interconnecting wires can have many K ohms of resistance and still work (at least at lower frequencies). So you can draw the traces on paper with a #2 or HB pencil, and they will conduct well enough to work! Lay the paper on a piece of nonconducting foam, punch the ICs through the paper+traces. Connect power, inputs, outputs and your other parts with paper clips. :-)


ICEs have the same problem as lightbulbs. Why innovate and make
better ones when the current ones burn out often enough to keep
you in business? -- Hunter Cressall
Lee Hart, 814 8th Ave N, Sartell MN 56377,

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