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muratic acid to etch PCBs anyone tried it? — Parallax Forums

muratic acid to etch PCBs anyone tried it?

codevipercodeviper Posts: 208
edited 2012-04-15 10:27 in General Discussion
I saw on youtube some one etching PCBs with hydrogen peroxide and muratic acid( i think that is what its called)
have any one of you tried this?
does it work well?

Comments

  • Wa_MoWa_Mo Posts: 17
    edited 2012-04-13 16:58
    Recently I started making my own printed wiring boards again. I had watched several videos on youtube and other sites, when I stumbled across this one
    http://quinndunki.com/blondihacks/?p=835

    I did use the vinegar and hydrogen peroxide method, but under not so ideal conditions. I used about 5 or 6 liquid ounces in total for a 3x4 inch board. The bowl was just big enough. As pointed out in the video, at first some tiny bubbles formed on the copper, then a thick layer of greenish guck which I removed constantly. I used an old but clean paintbrush for that. It took quite a while for the board to be etched. Didn't turn out too bad though. The etchant eventually turned a nice blue colour and wouldn't etch another board.

    I will try it again when my setup is in a better state. It is certainly cheaper than using ferric chloride.
  • Erik FriesenErik Friesen Posts: 1,071
    edited 2012-04-13 17:07
    I have done it. I don't like it, and here is why -

    You have to be extremely careful, plus the liability of having keeping and moving acid around. If you insist, keep PLENTY of baking soda handy.

    Its kind of touchy, it doesn't always work like you would think.

    If you don't do it right it will remove your etch resist.

    If you microwave ferric chloride it doesn't do too bad. Both types need correct agitation to work properly.

    I prefer having my boards made. If someone is paying you to make boards, its much cheaper to buy them.
  • LeonLeon Posts: 7,620
    edited 2012-04-13 17:09
    I tried it, and it works very well. I prefer ferric chloride, though.
  • idbruceidbruce Posts: 6,197
    edited 2012-04-13 18:17
    @codeviper

    I have not tried it yet, but I have had all the chemicals around for quite some time. After I get finished with all my other experiments, then I intend to experiment with this etching solution.

    Bruce
  • pik33pik33 Posts: 2,402
    edited 2012-04-13 21:59
    I tried hydrogen peroxide with salt and vinegar. It worked. It were early 198x years in Poland, so called martial law, when it was hard to buy anything here, but vinegar and salt was still available. (ferric chloride was unavailable). I lose one board because of too big concentration of these "chemicals"; after putting a board in it, it boiled and all copper was gone.

    When I got a real ferric chloride, I stopped these experiments. It was always risk losing all copper. This mixture was too strong, or, if more water added, didn't work at all.
  • Martin HodgeMartin Hodge Posts: 1,246
    edited 2012-04-13 22:25
    Leon, do you buy your FeCl in liquid form or anhydrous?
  • LeonLeon Posts: 7,620
    edited 2012-04-14 03:06
    I buy the anhydrous form. I get it here:

    http://www.rapidonline.com/Tools-Equipment/Copper-etchant-72531

    It's expensive, but when made up it lasts a very long time.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2012-04-15 09:46
    There are a lot of recipes for etching copper. Historically, copper etching primarily was used with intaglio printing (for centuries before the printed circuit board) and if you look to the fine art community you will find all sorts of formulas. Artist have long looked for getting fine detail.

    Muratic acid and hydrogen peroxide have been used. The real question is whether the muratic acid is too agressive and will result in jagged edges with undercutting. Ferric Chloride has long been a standard as it is NOT agressive. I have even seen some 'enhanced formulas' that claim that the addition of lemon juice in an acid will smooth edges and make the etchant last longer.

    Hydrochoric acid, Nitric acid, Sufuric acid, and so on are all possiblities.

    Face the simple fact - nearly any acid will etch copper. But it is smooth lines and a lack of undercut that you want. If you are satisfied with what you are using, that's the best.
  • codevipercodeviper Posts: 208
    edited 2012-04-15 10:27
    I have never etched my own board, and in my area the supplies to do so are not sold anywhere.
    I like the vinegar ideal. I have some old boards and I plan to test it.
    I am sick of having so many wires due to using strip boards.
    I actually made a 6502 SBC on a RS perf board...... :lol: i don't even know where it is right now.
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