Reusing Ferric Chloride for PCB Etching at Home

I feel PCB etching is one of the most required skill for a DIY electronic Hobbyist. During the etching procedure, you might have obviously heard of a useful chemical known as Ferric Chloride. You might have even tried etching a custom PCB by sponge rubbing method. People normally use the chemical just once and dispose it off. But in this instructable, I will teach you how to "REUSE" this Ferric Chloride solution and save your precious making "COSTS" right from your home with very less apparatus.

Most of the methods other than the method I used are relatively slower processes. So my method also saves 90% of your valuable "TIME".

Step 1: Materials Required

Please don't feel bad if I make your Kitchen a temporary Chemistry Lab ;-)

Materials Required:

>>A Metal Plate

>>Some Water

>>A Good Quality thick Plastic Container (Usually a grade 5 plastic and the one which in which your PCB board fits)

>>A Gas Stove for Fire

>>Reusable Ferric Chloride Solution

Step 2: To Start With

Fill a metal container (Plate) with water and start boiling it.

Place the plastic container with ferric chloride on the boiling water .

Reduce the flame so that its job is to just heat the chemical indirectly.

Step 3: Immersion

Immerse the PCB board that you have created using a Toner Transfer method into the ferric Chloride solution.

Since the rate of this reaction gets damn faster as the solution gets heated, you could expect the etching process completed within 5 to 10 minutes!

Its quite faster than any other method online that uses a PCB etching process using ferric chloride at home.

Step 4: Final Step

Since we are using a plastic container to keep the chemical, we can easily hold it with bare hands and stir it after every minute so that the copper precipitate that is accumulated over the board spreads out.

Repeat this procedure until the Board is free from any copper that is naked.

Store the ferric chloride in the same plastic container until next use.

Step 5: Tips

>>You can even choose the plastic container according to the shape and size of your PCB.

>>Solder the pads (and paths) with a layer of lead so that the tip of the driller stays well within the hole.

>>If possible, try to separate the copper precipitate from the ferric chloride solution before reusing it next time. You can do this easily by pouring the top layers of the solution into an another container and disposing the bottom most copper precipitate layer.

>>I have used a Unique Method of Recycling Ferric Chloride at home by turning your kitchen into a temporary laboratory. ;-)

Happy Etching

Comments

[pfred2]

If you want to make your etching even faster bubble the acid bath.
Bubbling the bath etches take about 2 minutes. Stirring, and shaking is
for the birds.

[TryxCorp]

Have I ever mentioned a word about stirring or shaking in my instructable?

Just observe from the below picture and please conclude that even bubbling the bath isn't necessary, the self vibration acquired by the plastic container is enough to do the job that u meant. Also note that this is only one of the best and cheapest alternative to a chem lab at home....

[borgsteam]

Something I am not seeing a lot of posts about etching, mention, is the use of peroxide, I wonder why that is, as my original investigation years ago for etching brass and copper panels from one side all the way through (like .01" thick though usually only .005" thick) mentioned this trick, as it along with heating helps speed the process up greatly, Additionally, the bubbling trick is as much for the birds as circulation by vibrating or stirring lol, get a heater using kanthal wire, wrapped around a container some what small, and two graphite plates on either side to pump this solution through, with voltage (positive on one side negative on the other) and you can push it all uphill to a system that sprays it over your items to be etched, or use a pump that can handle the actual solution, with all plastic and rubber bits inside, so you can put pressure on it going into your sealed heated tank, so that it sprays both up and down on the bottom and top of your boards, with resist on both sides, to get both extremely fast and clean results far better than any of the ones like you guys are mentioning, and it definitely can double for other tasks, since etching a bunch of plates then stacking them (with holes to bolt it all together) allows for an alternative to 3D printing with metal :)

as for drilling I am about to embark on a whole new way, using lasers to etch the resist, acid etch these boards, exposing both board under the outsides of my traces and inside the holes a bit, so I can then use the same laser to drill the board inside, as well as use kapton tape on thin copper sheet to make flexible units that can be then stacked on top of each other with solder points going through to make 2, 3, or even higher amounts of layered boards,

just thought I would share a third perspective on this, though a sonic bath modified to use for this (ie, coat the inside with spray on plastic or heat up a plastic polyethylene sheet like you get for paint tarps and such, to stick on and coat the inside) then pour in your solution, turn on the heater, and sonication unit to really get aggressive with that copper :)

I should also mention, you should not be throwing away this copper compound, as it is a good starting point for copper nano particles, instead sort it and hang onto that copper, so you can reuse it.

and you can use a couple tricks to get a salt bridge electrolysis cell to give you ferric chloride on the chlorine side of your bridge, and leave you with sodium hydroxide on the other, to use for neutralizing things. or chemistry to make your compounds you need for making the copper nano particles, that will fuse together with elbow grease to make pure copper sheet, or even strong flashes from strobe lights to make copper plating right on a board of choice. :)

[kavish laxkar]

what is the name f the software where i can design pcb.? and after dat etching process takes place.? plz rply.:)

[TryxCorp]

I used "diptace" software for PCB designing and I didn't get what your second question of your comment meant

[silentbogo]

Same thing works for Sodium Persulfate. Normally I etch at ~40°C, but at ~50-60° you can still get a bit more out of presumably used up solution.

Etching speed is definitely lower, but if it works - it works!

=)

[rwhite19]

great tutorial thanks
is it necessary to solder the pads and paths?

[TryxCorp]

the advantage of soldering the pads is that when you drill through the pads, the drill bit won't divert away from the hole

[TryxCorp]

sorry, replace **paths with pads in d above comment ! :-p