This is a really simple way to etch...
Jan 10, 2010 at 8:11 AM Thread Starter Post #1 of 11

Fred_fred2004

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I found this and while messing about with a little project thought I'd give it a shot

Sponge + Ferric Chloride Method -- Etch PCBs in One Minute!

You won't believe how quick and easy it is for a small prototype board or quick experiment,

CIMG6388Medium.jpg


that took about 3 minutes to do

Anyway it may be old news but I thought I'd pass it along

cheers
FRED
 
Jan 10, 2010 at 2:36 PM Post #3 of 11
this is really awesome!! I have been playing with the idea of etching my own board for the transformer coupled and diamond buffered output for an upcoming dac project. the traces will be chunky so a good place to start a first project. this looks great, have you got an recommendations for where to get supplies for the PCB and copper material?
 
Jan 10, 2010 at 7:28 PM Post #5 of 11
I hate the idea of throwing this stuff out.

The more I look into different etching baths, the more sense it makes to use an old fashioned sulfuric acid bath. It's very easy to precipitate the copper, so there's no real environmental issue. The only downside is you have to keep careful control of temperature. A couple degrees off and it'll go exothermic and explode. (j/k) No problem with a good thermometer and some ice made from distilled water.
 
Jan 10, 2010 at 10:19 PM Post #6 of 11
Quote:

Originally Posted by qusp /img/forum/go_quote.gif
this is really awesome!! I have been playing with the idea of etching my own board for the transformer coupled and diamond buffered output for an upcoming dac project. the traces will be chunky so a good place to start a first project. this looks great, have you got an recommendations for where to get supplies for the PCB and copper material?


Hi
In Australia so I've found Altronics best for Ferric Chloride and they also have the PCB, it has to go by road mail because of the chemicals. The method is so easy you won't believe it
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Jan 10, 2010 at 11:19 PM Post #7 of 11
Quote:

Originally Posted by SiBurning /img/forum/go_quote.gif
The more I look into different etching baths, the more sense it makes to use an old fashioned sulfuric acid bath. It's very easy to precipitate the copper, so there's no real environmental issue. The only downside is you have to keep careful control of temperature. A couple degrees off and it'll go exothermic and explode. (j/k) No problem with a good thermometer and some ice made from distilled water.


What molarity are you thinking of trying this with? The other downside of course, is burning a hole through your hand or other body part - and then having to toothbrush scrub the wound with baking soda to stop the acid from eating through more organic material (horror stories from University). Might not be worth the PCB
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But I'd be willing to try it in a lab where I could control all the variables.
 
Jan 11, 2010 at 2:14 AM Post #8 of 11
Quote:

Originally Posted by pixeljedi /img/forum/go_quote.gif
What molarity are you thinking of trying this with? The other downside of course, is burning a hole through your hand or other body part - and then having to toothbrush scrub the wound with baking soda to stop the acid from eating through more organic material (horror stories from University). Might not be worth the PCB
wink.gif
But I'd be willing to try it in a lab where I could control all the variables.



1-6? Also needs nitric acid and potassium chloride. Definitely not thinking about trying it. It's easier to get all the excess copper out, so it can be more environmentally friendly, but there's more fumes than with the other methods, and the fumes are a lot more dangerous. (Mutters something about needing a gas mask.) It's just that I've been reading about all the methods and how to use them safely over the long term, including storage and disposal. The second to last thing I want to do (next to die a quick but painful death) is dump copper down the drain.

Been looking around since seeing this thread. There's plenty of stuff on the web about regenerating cupric chloride (CuCl). I haven't looked in enough detail, but it looks like you can regenerate FeCl easier and safer than CuCl, and without having excess poisonous etchant grow over time. The FeCl bath would grow, but iron's not nearly the problem to get rid of.

You can recover the copper from FeCl through electro-whatever the word is. It might even be possible without electricity, just a steel spoon. The iron displaces copper in solution and you get a coating of copper on the spoon. The same thing that makes it hard to precipitate the copper makes the iron displace the copper. Aluminum would work, too, but you don't want to make the bath too complicated.

If you try to do something like this in a CuCl solution, you'd give off chlorine gas, which you'd have to replenish with hydrochloric acid (HCl) and just end up diluting the solution or making more of it.

You can also reduce the sludge by using acid and by bubbling with air. Look up Edinburgh Etch. It uses citric acid--vitamin C. Most any acid would probably do, but I'd probably only substitute HCl for safety.

The main reason I don't like FeCl is that you're forced to dispose of copper into the environment. Neutralizing it with baking soda or lime and then bricking it in concrete isn't safe at all. It's a lot more complicated than that. If you could really neutralize the copper, you could precipitate it or something, and dispose of it properly, but it's more difficult to do this in FeCl than almost any other etchant.

Maybe there's hope here. Will keep looking into it. I'm sure there's something missing or people would be doing it.
 
Jan 11, 2010 at 11:27 AM Post #10 of 11
Quote:

Originally Posted by fordgtlover /img/forum/go_quote.gif
Fred, what do you use to transfer the layout?


Hi, just the good old toner transfer :)
 
Jan 11, 2010 at 11:33 AM Post #11 of 11
The look incredibly interesting - and the website linked makes it sound like fun... so interesting that I may get brave enough to try it on a couple of things I'd like to make.

Thanks for sharing it!!!
 

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