Etching circuit boards

[Faber]

Hello all!  I've been building stompboxes for about a year now (only have 3 builds done... lack of pots, switches, money) and am already sick of perfboard.

If I can find a cheap etching set, should I get it?  How complicated is the process?

I just don't really want to perfboard stuff like the Tubescreamer and Big Muff...

[niggez]

This is the cheapest method. It works for me. Always.

1 pack of Ferric Chloride (Cost me around 2 Euros, lasted for 8 pcbs so far, but still some left)         2 Euro
1 Edding marker (Select one with a small tip, so you can draw small lines with it                             1 Euro
1 blank pcb (Copper on one side, nothing on the other...you know what i mean)                              1 Euro
1 Small plastic box, tupperware proved ideal for me                                                                     
1 Something to move / insert / take out stuff from the box (for example tweezers, pliers)
1 Something to remove the edding once youre done etching. Acetone is perfect. (I got 100ml)          2 Euro

All this stuff lasts for a lot of uses!
So this is all you need for the basic method. You start by getting a layout of the pcb, which you then draw on the copper pcb with the edding marker. After a bit of practice, it can be done quite fast. I have done all my projects like this so far, larger pcbs require a bit of time, and you have to be careful.
I recommend taking the layout and pinning holes through the places where holes need to be, then place it on the pcb blank and with the edding, transfer the holes. That way you now just need to check where lines go, and "connect the dots" properly!
After youre done, mix some Ferric Chloride with water in the small box, place the pcb inside. Now wait. If you have a lamp, put it close over it, heat speeds up the process. If you dont, it doesnt matter, it will only take longer. Dont get impatient, the edding holds up like a champ and i have never had problems with any of it coming off. It helps to move around the pcb inside the etchant, every now and then.
Once the copper has cleared, take out the pcb and rinse it in water.
Collect the used etchant in some sort of etch-proof container and take it to your local waste disposal! Its harmful to the environment.
Then you take a small tissue, dip it in acetone, and remove the edding.
You now have your pcb! Just drill the holes and youre done.

If you have any questions, if i can i will answer them!

[Morocotopo]

Hi Faber, Smallbear (see links above) sells, I think, an etching set. Or you can gather all the materials on your own, not difficult to find them. Some places have tutorials on etching (Tonepad is the one that comes to mind now), again see links above. Google etching tutorial or something like that.
It´s not complicated, just several steps to follow. You´ll need to learn the process, only experience will tell you what matters and what doesn´t. Eventually you´ll develop your own little method. Be ready to have some failures as you learn, it will happen... don´t get discouraged. Be stubborn. Yes, you´ll waste some material, but you´ll learn eventually. Once you populate an etched PCB, you´ll never go back to perf, at least for more complicated schems.

Morocotopo

[Morocotopo]

hmmmm, niggez, the flushing down the toilet part is not a very good idea, for your plumbing and for the environment...

Morocotopo

[bkanber]

I recently started etching PCB as well.. there are a couple of ways to do it, so here's the one I do:

Print the PCB layout onto high-gloss photo paper with a Laser printer (wax printers work too, but inkjet wont).
Iron the layout onto the copper board. I usually put a lot of pressure on it for 10 minutes or so.. you might need less, I haven't experimented much with that....
Alternatively, you can get some press-n-peel blue from a site like pedalpartsplus.com. Supposed to be better than the photo paper.. i haven't tried it yet, but will be using it for my next project.
Gently wash the paper off of the board (soak it in soap and warm water).. don't want the ink to lift off.
Fill in any breaks in the ink with a sharpie
Etch with etchant! The industry standard is ferric chloride. I'm going to be experimenting with cupric chloride (it's easy to make, reusable, and faster than ferric chloride)

I prefer the photo paper/press-n-peel because I just really dont have enough patience to draw the whole layout on the board. I also have a really small drill bit (1/32") that I use to drill the holes. You'll probably have to mail order for that, I wasn't able to find it in any hardware stores...

Hope that helps,
  Burak

[niggez]

I wasnt sure about it either, but i read small amounts of it dont do any harm. As long as you dont pour it in the sink. The concentration must be extremely low with the water i mix it with after im done, plus the water from flushing, plus flushing again...
I just looked it up and found its not supposed to go down the drain. Sorry for that info i guess i was wrong. Thanks for pointing it out though, i must have had a bad source before!

[plankspank]

Here's a good tip that I found on this forum: drill a small hole on the PCB and attach some plastic fishing line to it. You can then dunk & agitate at the same time. I use a plain old glass jar to hold the Fe Cl. When done etching, just dunk it into a bucket of water to stop the etching... a lot less messier than a tank & tweezers...You can also reuse the etchant several times.

[plankspank]

hmmmm, niggez, the flushing down the toilet part is not a very good idea, for your plumbing and for the environment...

Especially if your House waste stack is copper!

[Electron Tornado]

If you need an inexpensive way to get started in PCB etching you can try Radio Shack. I think they still sell a kit that comes with a plastic box, sharpie marker, bottle of etching solution, a bottle of "resist marker reover" (i.e. isopropyl alcohol), and an abrasive pad. It may come with a couple of boards as well, I don't recall.

The plastic box is really cheap so I use half of it for etching boards. Radio Shack also has bottles of ferric chloride for etching. Not everyone may stock it, but they can order it, so see how their price compares with other places.

Some folks turn their noses up at Radio Shack, but their stuff has worked for me for PCBs. Heck, I just bought a new soldering iron from there after the previous one I also got from there stopped working. I had that soldering iron for almost 30 years.

[zachomega]

So where does everybody in the US order these supplies from then? 

-Zach

[Faber]

Thanks you guys!!!  I'm just gonna forget the kit and buy the stuff separately (more in the DIY spirit )

Just one more thing, what's the best way to punch a hole in the board?

[Hamfist]

Good luck finding etching solution at Radio Shack anymore.  I'm in Kentucky, and the store I went to managed to find two bottles in Florida.  This was after they told me over the phone they had some in stock and I drove all the way across town to find they didn't have any.  *AND* there was not a spot on the shelf for it.  The warehouse didn't have any.  Just two bottles in Florida. 

The reason I turn my nose up at Radio Shack is because they ran me across town to buy something they actually didn't have (and didn't know what I was talking about once I got there)... after they assured me that they had some.  And yes, I'm positive I went to the right store.  After I confronted the person I talked to on the phone, she disappeared to the back.  Then when the guy was requesting the store in Florida to transfer the two bottles to here, he said "They must be using this stuff to make crack".  THEN in a really condescending, patronizing tone he assured me that he would be holding the bottles in his hand when he calls to let me know they're in.  AND THEN they never called me.  That's why I have no use for Radio Shack, even though I do like their LED bezels.

Now I etch with muriatic acid and hydrogen peroxide.  It's faster, easier, cheaper, and I can buy everything I need within two blocks of my apartment.  Plus the guys at the hardware store down the street are hilarious.       

If you need an inexpensive way to get started in PCB etching you can try Radio Shack. I think they still sell a kit that comes with a plastic box, sharpie marker, bottle of etching solution, a bottle of "resist marker reover" (i.e. isopropyl alcohol), and an abrasive pad. It may come with a couple of boards as well, I don't recall.

The plastic box is really cheap so I use half of it for etching boards. Radio Shack also has bottles of ferric chloride for etching. Not everyone may stock it, but they can order it, so see how their price compares with other places.

Some folks turn their noses up at Radio Shack, but their stuff has worked for me for PCBs. Heck, I just bought a new soldering iron from there after the previous one I also got from there stopped working. I had that soldering iron for almost 30 years.

[bkanber]

Just one more thing, what's the best way to punch a hole in the board?

I'm going to stick by my prior statement and say that picking up a 1/32" drill bit is the best way to go for making all those tiny holes...

Now I etch with muriatic acid and hydrogen peroxide.

Yeap! That's the cupric chloride I was talking about earlier! After your first etch or so, the HCl turns into CuCl, and a redox reaction takes over

[boogietube]

I use these photoessays at Tonepad. Works every time.

http://www.tonepad.com/photoessays.asp

They're near the bottom of the page.

[Zben3129]

"You have questions (or etchant), We have batteries!" -RatShack

Anyways, +1 for Muriatic and Hydrogen Peroxide. Its faster, cleaner, and just overall better than FeCl. Clear so you can see what is going on to. And it makes hydrogen bubbles aswell  (Don't worry, not enough to do anything, unless you are etching like 200 boards at once with the whole thing heated).

gallon of muriatic is around 5 bucks here, and hydrogen peroxide is cheaper still. Go 2:1 perox:muriatic. As a bonus, the copper salts make the solution more potent every time you use it (culpric chloride) to a point.


Zach

[FrankB]

Radio shack has an awesome kit. Blank copper boards, a sharpie, all the things ou need to make fun stuff. For $15.00