Author Topic: EEVblog #1197 - DIY PCB Etching With Water (Read 12354 times)

EEVblog · « **on:** March 31, 2019, 10:02:16 am »

Experimenting with etching your own PCB's by concentrating existing ferric chloride levels in tap water. How well does it work?

rs20 · « **Reply #1 on:** March 31, 2019, 10:46:07 am »

Unbelievably good results! Do you think there might be applications in producing more eco-friendly PCBs?

EEVblog · « **Reply #2 on:** March 31, 2019, 10:50:09 am »

Quote from: rs20 on March 31, 2019, 10:46:07 am

Unbelievably good results! Do you think there might be applications in producing more eco-friendly PCBs?

Someone on Youtube mentioned a new RoHS standard that includes this?

Hootch · « **Reply #3 on:** March 31, 2019, 11:07:40 am »

Amazing idea!
Although I was a little bit sceptic, I tried it, and it actually works quite good. I even was able to get a better result with four magntes arranged in a x-shape. Put the glas on the cross of magnets and do as Dave did it. It also helps to say and repeat the following little prayer until the copper is completely removed:

Almighty God
Please help to
Remove the copper
In order to make a
Lowcost PCB.

For thou hast the power
Of increasing the concentration
Of Iron and chlorine in this
Liquid for ever and ever. Amen.

Dave, I know your opinion about religion, and I also didn't believe it first. But this works really better than your procedure.

Greetings!

ludzinc · « **Reply #4 on:** March 31, 2019, 11:22:44 am »

I’ll have to try this tomorrow!

Cnoob · « **Reply #5 on:** March 31, 2019, 11:34:23 am »

Here is another tit- bit of information on Iron dissolved in water, the forming of "bog iron",https://en.wikipedia.org/wiki/Bog_iron.

JackJones · « **Reply #6 on:** March 31, 2019, 11:36:49 am »

I tried it with photoresist, works a treat!

Although it did take me closer to 1.5 hours to etch. There must be pretty large differences between local water supplies.

Whales · « **Reply #7 on:** March 31, 2019, 11:52:18 am »

Negative result here. My tracks ended up solder plated instead of etched.

I might try running the tap into the sink for a while first, get rid of local plumbing contaminants.

wilfred · « **Reply #8 on:** March 31, 2019, 11:58:00 am »

What sort of magnet was it that you used. I'll have to try this. I once left an old magnet next to a copper water pipe in my laundry for years and it eventually leaked. I thought I was being clever because it was meant to attract the rust particles that caused problems in my film developing days. I've replaced all of the galvanised steel pipes now of course but I'm a bit concerned.

ZeTeX · « **Reply #9 on:** March 31, 2019, 12:25:21 pm »

I've tried it and it worked great! I had to leave it for a few hours actually, but hi, it is definitely worth it! save the mess of using ferric chloride, and save some money!
I recommend using the magnets you get from a hard drive, they are strong and work great.

EEVblog · « **Reply #10 on:** March 31, 2019, 12:39:47 pm »

Quote from: wilfred on March 31, 2019, 11:58:00 am

What sort of magnet was it that you used.

Fluke meter hanger magnet. Couldn't find my huge block one after the move.

nixfu · « **Reply #11 on:** March 31, 2019, 01:38:53 pm »

>with four magntes arranged in a x-shape.

I got even better results with the magnets arranged in a pentagram, but this only works for PCB's to be used in "evil" applications such as nuclear weapons, and sex bots.

Rolo · « **Reply #12 on:** March 31, 2019, 01:46:53 pm »

Here in my country the water is best in april so I will try it tomorrow.

tggzzz · « **Reply #13 on:** March 31, 2019, 01:48:12 pm »

Quote from: EEVblog on March 31, 2019, 10:02:16 am

How well does it work?

Since this isn't "obvious to someone skilled in the art", you could have patented it.

But you can't because you disclosed it. The bright side is that now it has been disclosed, nobody else can patent it and stop you using your invention.

So go ahead and see if you can make all your boards like this

golden_labels · « **Reply #14 on:** March 31, 2019, 01:50:33 pm »

I had no glass big enough, so I’ve used my grandma’s copper bowl. The PCB was untouched until I placed a strong magnet under the bowl to ensure automatic stirring of the solution. I think this is the key: it etched the PCB in just 12 minutes. Now I need advise… where can I quickly buy a new, good quality copper bowl?

SilverSolder · « **Reply #15 on:** March 31, 2019, 02:01:16 pm »

Bud · « **Reply #16 on:** March 31, 2019, 02:45:00 pm »

It is just begging to run a competition how small track/spacing width you can get.

jim_griff · « **Reply #17 on:** March 31, 2019, 03:17:39 pm »

It may not be the appropriate time to post this video (depending on where you live on the planet) but here's my experiment and video response:

https://youtu.be/dzL3hDtHzTI

German_EE · « **Reply #18 on:** March 31, 2019, 04:38:08 pm »

I was with you up to the point where it started working, then I thought of the copper water pipes in our bathroom, then I looked at the date.

Nice one, well done

P.S. Water containing Ferric Chloride isn't magnetic but blood which contains iron IS. Look around and you'll find some interesting experiments.

free_electron · « **Reply #19 on:** March 31, 2019, 04:54:53 pm »

I tried it with my home-delivered bottled water. After 8 hours : nothing. so that proves my water is very clean and does not contain Fe3Cl ! Good.
Then I tried it with tap water here in silicon valley. Etched pretty fast ( a good 25 minutes faster than Daves results) . That probably is because we had so many chemicals form all the old waferfabs leaking into the groundwater.

I found out that i could speed up the process even more if i added a bit of Ammoniumpersulfate or sodiumpersulfate to the water. Side-effect is that it does turn the water a beautiful shade of blue.

GigaJoe · « **Reply #20 on:** March 31, 2019, 05:13:13 pm »

3% Hydrogen Peroxide + citric acid (white crystals) + kitchen salt
use a plastic bag, warm in hot water ...

UPD, riaiaiaight ... I'm in 31 Match time belt, still

firewalker · « **Reply #21 on:** March 31, 2019, 05:17:42 pm »

I used the lab centrifuge and the result was better than using a strong magnet. I used tap water.

Alexander.

GigaJoe · « **Reply #22 on:** March 31, 2019, 05:22:07 pm »

i have a few centrifuges that i use to use to enrich uranium, so I wonder if I will using it, with sequence of helium cooled magnet, wonder if possible to reach close to 100% ferrite concentration?

SparkyFX · « **Reply #23 on:** March 31, 2019, 05:24:25 pm »

Damn internet, now you´re not even safe half a day before. :-)

toby_muc · « **Reply #24 on:** March 31, 2019, 05:29:23 pm »

Damn, doesn't work in southern Germany, bloody mountain-spring-water ...

Urs42 · « **Reply #25 on:** March 31, 2019, 06:23:35 pm »

You need chinese tap water, it has more ferric chloride:

scuzzyTerminator · « **Reply #26 on:** March 31, 2019, 07:30:08 pm »

Might be simpler and better to Blu-Tack® neodymium magnets to the back of the board. That will attract the little ferrus buggers to concentrate around the board.

Nusa · « **Reply #27 on:** March 31, 2019, 08:53:39 pm »

Makes you wonder why copper water pipes last so long. Especially the hot-water ones.

jesuscf · « **Reply #28 on:** March 31, 2019, 08:57:49 pm »

I said it before, I say it again: most of the world have no idea about this April tradition that is carried out in some English speaking countries.

ataradov · « **Reply #29 on:** March 31, 2019, 09:59:42 pm »

This one I actually disliked. This was a huge and malicious waste of my time.

TK · « **Reply #30 on:** March 31, 2019, 10:05:25 pm »

Holy smokes, I tried it and ended up with gold plated traces! Next project is to recover the gold using the reverse process.

grumpydoc · « **Reply #31 on:** March 31, 2019, 10:07:44 pm »

Still the 31st here but excellent "Poisson d'avril"

DC1MC · « **Reply #32 on:** March 31, 2019, 10:13:18 pm »

Quote from: toby_muc on March 31, 2019, 05:29:23 pm

Damn, doesn't work in southern Germany, bloody mountain-spring-water ...

That mostly works with water available around old copper mines or other non-ferrous metals, like they are plenty in Oz, in Southern Germany one needs to add a tea-spoon or two of Bärlauchsalz depending on PCB surface and use 12V AC.

Cheers,
DC1MC

M4trix · « **Reply #33 on:** March 31, 2019, 10:19:53 pm »

I was... WTF ?

...then a I looked at the calendar !

darik · « **Reply #34 on:** March 31, 2019, 11:27:26 pm »

It was when you brought up the magnet that I realized you're a day ahead of me.

coppercone2 · « **Reply #35 on:** March 31, 2019, 11:28:23 pm »

i am going to start a PCB etching bushiness in australia. this reduces cost of manufacture significantly!

M4trix · « **Reply #36 on:** March 31, 2019, 11:32:53 pm »

Quote from: coppercone2 on March 31, 2019, 11:28:23 pm

i am going to start a PCB etching bushiness in australia. this reduces cost of manufacture significantly!

That's a big nope ! You'll have to waste a lot of water to collect a decent amount of Ferric Chloride !

GigaJoe · « **Reply #37 on:** April 01, 2019, 04:32:22 am »

no waste water at all: bottled water "EE-IONS" brand. and ship it to China.

o! post# 222 ...

ahakman · « **Reply #38 on:** April 01, 2019, 06:14:23 am »

WTF, I posted in this thread last night (though I didn't have time to build it to scale, OR paint it), and now it's deleted?? Huh?

artag · « **Reply #39 on:** April 01, 2019, 09:22:31 am »

Shouldn't you dilute that concentrated water before you pour it down the drain ?

bitwelder · « **Reply #40 on:** April 01, 2019, 09:31:21 am »

Hmm... I'll steal the idea and go prepare an Indiegogo campaign for a special magnet that makes PCB etching at home so much quicker.

BRB!

Psi · « **Reply #41 on:** April 01, 2019, 09:37:24 am »

Back to reality though. I do wonder if you actually left a tap dripping on a PCB for an entire year, would it dissolve any copper?
I'm not sure, but if it did i wouldn't be all that surprised.
There's bound to be something in tap water that will slowly eat copper over a long enough time frame

a59d1 · « **Reply #42 on:** April 01, 2019, 09:47:13 am »

Quote from: ataradov on March 31, 2019, 09:59:42 pm

This one I actually disliked. This was a huge and malicious waste of my time.

How could you do this to us, Dave?

BU508A · « **Reply #43 on:** April 01, 2019, 09:48:42 am »

Quote from: ataradov on March 31, 2019, 09:59:42 pm

This one I actually disliked. This was a huge and malicious waste of my time.

Here, this one's for you.

MT · « **Reply #44 on:** April 01, 2019, 01:58:19 pm »

Quote from: Cnoob on March 31, 2019, 11:34:23 am

Here is another tit- bit of information on Iron dissolved in water, the forming of "bog iron",https://en.wikipedia.org/wiki/Bog_iron.

And as usually wikipedia is full of errors as if it was made outoff 1 April's all year around.

simpson · « **Reply #45 on:** April 01, 2019, 02:21:45 pm »

The Apollo 13 astronauts used this trick to repair their damaged navigation computer which allowed them to safely land in a New Jersey Sears & Roebuck parking lot.

Tom45 · « **Reply #46 on:** April 01, 2019, 02:46:21 pm »

Quote from: SparkyFX on March 31, 2019, 05:24:25 pm

Damn internet, now you´re not even safe half a day before. :-)

Actually, it's damn international date line.

simpson · « **Reply #47 on:** April 01, 2019, 03:02:07 pm »

I have a limiited supply of special PCB etchant magnets which I will part with for $10 each. I also have for sale a supply of dehydrated toxin-rich Los Angeles tap water @ $5 per gallon.

free_electron · « **Reply #48 on:** April 01, 2019, 03:53:28 pm »

Quote from: ataradov on March 31, 2019, 09:59:42 pm

This one I actually disliked. This was a huge and malicious waste of my time.

time well wasted.

coppercone2 · « **Reply #49 on:** April 01, 2019, 04:45:46 pm »

Quote from: M4trix on March 31, 2019, 11:32:53 pm

Quote from: coppercone2 on March 31, 2019, 11:28:23 pm
i am going to start a PCB etching bushiness in australia. this reduces cost of manufacture significantly!

That's a big nope ! You'll have to waste a lot of water to collect a decent amount of Ferric Chloride !

you sell it as spring water after you get the chloride out

asgard · « **Reply #50 on:** April 01, 2019, 05:15:59 pm »

Okay, better way to concentrate ferrous solutes from tap water:

1. use a conic separation funnel with a good stopcock ($30.45 USD at Amazon).
2. Fill with your tap water and mount at least one good neodymium magnet near the bottom .
3. Leave the stopcock closed and let the water evaporate out the top.
4. Refill as desired until complete, and again at the very last time of the period.
5. You will get higher concentrations of all dissolved salts that occur at the outflow of your water treatment plant. I do not know the ambient water hardness figures in Sydney, but it surely cannot be worse than the waters here in the far upper Sacramento River valley area (Redding).

I think you will get reagent contamination primarily from Mg and Cu salts. The copper is most concerning as that will affect the reaction rates of the FeCl3 + Cl case.

Brumby · « **Reply #51 on:** April 02, 2019, 01:07:06 am »

I like the evaporative method myself, but it is rather slow.

Quote from: asgard on April 01, 2019, 05:15:59 pm

I do not know the ambient water hardness figures in Sydney, but it surely cannot be worse than the waters here in the far upper Sacramento River valley area (Redding).

Sydney's water hardness is pretty good.

If you want hard water, go to Adelaide. Their water is so hard they only mix sand and aggregate with it when making concrete.

Mike Warren · « **Reply #52 on:** April 02, 2019, 01:38:59 am »

I thought everyone knew this technique.

Homeopathic PCB etching.

kosine · « **Reply #53 on:** April 02, 2019, 11:19:23 am »

Seems that in principle the idea isn't that crazy.

I tried a very dilute ferric chloride solution last night (maybe around 2-3%), and the copper had all been etched away when I checked this morning. (Water was cold, not heated.)

Might be an interesting follow-up experiment to see just how dilute you can go. <1% might even work since the total amount of copper being removed is tiny. A comparable amount of FeCl3 might be all it takes.

I'm trying it again with just a few drops.

orion242 · « **Reply #54 on:** April 02, 2019, 03:03:19 pm »

Found adding a few grams of graphene per ounce of water dramatically sped up etching. Still nothing to write home about over the standard methods.

coppercone2 · « **Reply #55 on:** April 02, 2019, 04:24:39 pm »

Quote from: kosine on April 02, 2019, 11:19:23 am

Seems that in principle the idea isn't that crazy.

I tried a very dilute ferric chloride solution last night (maybe around 2-3%), and the copper had all been etched away when I checked this morning. (Water was cold, not heated.)

Might be an interesting follow-up experiment to see just how dilute you can go. <1% might even work since the total amount of copper being removed is tiny. A comparable amount of FeCl3 might be all it takes.

I'm trying it again with just a few drops.

i think you get more undercutting if its slow?

kosine · « **Reply #56 on:** April 02, 2019, 05:06:35 pm »

Quote

i think you get more undercutting if its slow?

That did cross my mind. I haven't tried masking off anything yet, just curious about the minimum concentration. Probably not going to be a great technique for tiny traces, but maybe try that experiment next.

Current few-drops test is actually looking promising. Only been a few hours but the copper has turned quite brown already, so something is happening. Will see what happens over night.

AlfBaz · « **Reply #57 on:** April 02, 2019, 05:30:17 pm »

I take iron supplements and do laps every day in a chlorinated swimming pool so I decided to try it with my urine.
Turns out I don't even need magnets

wilfred · « **Reply #58 on:** April 02, 2019, 11:16:10 pm »

Quote from: AlfBaz on April 02, 2019, 05:30:17 pm

I take iron supplements and do laps every day in a chlorinated swimming pool so I decided to try it with my urine.
Turns out I don't even need magnets

OK, now I know you're just taking the piss.

Brumby · « **Reply #59 on:** April 03, 2019, 01:15:18 am »

(Gotta pay that one

)

kosine · « **Reply #60 on:** April 07, 2019, 11:05:11 am »

Took nearly a week but amazingly it worked!

A little over 50g of water with under 0.5g of etchant solution at around 10C. Bottle doesn't state the concentration, but probably about 30% ferric chloride. So roughly we're down to around 0.25% or 2500ppm.

Psi · « **Reply #61 on:** April 09, 2019, 07:16:24 am »

Sometimes if you see a house with copper spouting/guttering and there's a spot where water is leaking out and then down the side of the house you will notice that area is cleaner and free from any mold spots.
I'm pretty sure the rainwater is getting some tiny amount of copper salts dissolved into it as it comes into contact with the copper. Then this is acting as a fungicide as it runs down the side of the house.

Even at super low concentrations chemical reactions still occur, they just take super long


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Author Topic: EEVblog #1197 - DIY PCB Etching With Water (Read 12354 times)

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