Questions about PCB making the etching way

Using Arduino General Electronics
#1

hello everyone,
i need please some help with making a PCB using the etching and ferric chloride way
I bought a bottle of ferric chloride 500g powder, so i tried to print the PCB layout on a copper board, i used glossy A4 but it did not print well :confused: then i added some lines and traces with anti acid pen, then i put about 1 small spoon of powder in water and put the board in it, but seems it did not work, so what i need to know is :

1-how much powder small plastic spoons is needed to put in water

2- which paper is considered best for this application ? is the Transparent good? (i checked many tutorials videos and sites, they suggest the glossy but it did not work well with me :/)

3- After finishing from the solution where should i get rid of it ? for this time i throw it in the toilet after it got very poor, is this good to be done or bad ?

#2

Ferric chloride is acidic and poisonous, typically you would netralize it with a mild base such as
washing soda. It is typically banned from waste water systems as an industrial pollutant.

Etchant solution needs to be warm and fully dissolved before adding the board. Constant agitation
is needed. The solution should be fairly strong or it won't work. Always add the solid to the liquid
when preparing caustic solutions, wear eye protection and gloves (and a mask if in powdered form).

Don't use kitchenware for this, separate utensils for chemical use only.

#3

MarkT:
Ferric chloride is acidic and poisonous, typically you would netralize it with a mild base such as
washing soda. It is typically banned from waste water systems as an industrial pollutant.

so we must neutralize it before throwing it in the toilet ? and which soda you mean the one we put in the washing machine to wash the clothes ?

MarkT:
Etchant solution needs to be warm and fully dissolved before adding the board. Constant agitation
is needed. The solution should be fairly strong or it won't work. Always add the solid to the liquid
when preparing caustic solutions, wear eye protection and gloves (and a mask if in powdered form).

Don't use kitchenware for this, separate utensils for chemical use only.

alright good advices thank you

#4

I havenā€™t used ferric chloride etchant - I did the HCl/CuCl2 method, regenerating with a tiny bit of 30% hydrogen peroxide (drugstore peroxide isnā€™t strong enough, itā€™s only 3%, so the etchant gets diluted, but some quack wrote a book called ā€œone minute cureā€ promoting hydrogen peroxide as a cureall, so you can buy food grade hydrogen peroxide easily online now. Hurray for sham medicine! Note that 30% peroxide burns skin - worse and faster than HCl or concentrated lye - and bleaches clothes). That way you donā€™t have to dump copper salts down the drain, and itā€™s cheaper.

Cheap glossy paper is best. Not photo paper, photo paper and high end gloss has like plasticy stuff on it, which sticks very tightly to the toner. I think I had good results with Hammermill Color Laser Gloss.

I think most people just wash etchant down the drainā€¦

#5

DrAzzy:
I haven't used ferric chloride etchant - I did the HCl/CuCl2 method, regenerating with a tiny bit of 30% hydrogen peroxide (drugstore peroxide isn't strong enough, it's only 3%, so the etchant gets diluted, but some quack wrote a book called "one minute cure" promoting hydrogen peroxide as a cureall, so you can buy food grade hydrogen peroxide easily online now. Hurray for sham medicine! Note that 30% peroxide burns skin - worse and faster than HCl or concentrated lye - and bleaches clothes). That way you don't have to dump copper salts down the drain, and it's cheaper.

Cheap glossy paper is best. Not photo paper, photo paper and high end gloss has like plasticy stuff on it, which sticks very tightly to the toner. I think I had good results with Hammermill Color Laser Gloss.

I think most people just wash etchant down the drain....

well the thing is that the ferric chloride is what's available :confused:

so about the soda it's the washing machine chemicals ?
i tried to put Persil washing powder well i saw a strange behavior the ferric water became dense with some strange color with bubbles i don't know if that is what should happen before throwing it in the toilet

about the paper i tried the cheap glossy paper A4 didn't work well at all :confused:

#6

firashelou:
well the thing is that the ferric chloride is what's available :confused:

so about the soda it's the washing machine chemicals ?
i tried to put Persil washing powder well i saw a strange behavior the ferric water became dense with some strange color with bubbles i don't know if that is what should happen before throwing it in the toilet

about the paper i tried the cheap glossy paper A4 didn't work well at all :confused:

I do not know where your toilet water goes, but I would offer that the copper in the fluid is poisonous.
do not dump into a home cesspool.
any concrete will yield the base you need to counteract the acid.
if you want, you can pour on concrete. then allow it to evaporate.
the acid will etch your porcelain in your toilet and the copper will stain it dark red.
you could put it into a plastic container with rocks and put into the garbage.

#7

As a rough guide 500g of ferric chloride should be dissolved in 1 litre of water..

For disposal 500 g ferric requires approx 1.5 kg of sodium carbonate to neutralise it all.

Sodium persulphate is a cleaner to use etchant but has a shelf life of about 6 weeks once mixed.

The effluent is acidic copper sulphate but most sewage plants can cope with small quantities.

Ferric chloride keeps indefinatley until exausted.

When correctly neutralised , copper carbonate is relativley insoluble, copper salts are the more poisonous of the effluents.

FWIW ferric chloride is used as a flocculating agent in small concentrations for the preperaation of potable water.

The presence of copper however would be somewhat undesirable in soluble form.

#8

You could try salt water etching also:

#9

firashelou:
well the thing is that the ferric chloride is what's available :confused:

so about the soda it's the washing machine chemicals ?
i tried to put Persil washing

Persil is a very poor chouce, totally the wrong stuff.

You need washing soda, sodium carbonate , pure, 3 x by weight of the ferric chloride.

Add slowly as it will fizz like crazy.

Continue to add until the fizzing stops.

Better, use litmus paper until neutral.

#10

CrossRoads:
You could try salt water etching also:
Google

There are some alternativ recipies out there, although the ingredients may appear benign the effluent is often acidic copper which is not , its soluble in the water table.

#11

firashelou:
hello everyone,
i need please some help with making a PCB using the etching and ferric chloride way
I bought a bottle of ferric chloride 500g powder, so i tried to print the PCB layout on a copper board, i used glossy A4 but it did not print well :confused: then i added some lines and traces with anti acid pen, then i put about 1 small spoon of powder in water and put the board in it, but seems it did not work, so what i need to know is :

1-how much powder small plastic spoons is needed to put in water

Did you try google? This page recommends 40% by weight, about half-way down.
I use the solid stuff, which might be a different strength than the powder, and mix at 33% by weight.

2- which paper is considered best for this application ? is the Transparent good? (i checked many tutorials videos and sites, they suggest the glossy but it did not work well with me :/)

For best results you should use a matt finish transparency film, not paper.
I use GCC Laser Printer Film, (Code: 90 MY A4).
You can print the PCB pattern onto the film with a laser printer. Much better than hand-drawing it.

3- After finishing from the solution where should i get rid of it ? for this time i throw it in the toilet after it got very poor, is this good to be done or bad ?

Kitchen baking soda is what I use to neutralise it, (bicarbonate soda).

As MarkT says, warm the mixture before using it. I keep my mixture in a plastic jug and re-use it over and over for several years. I place the jug in a bucket about 10 minutes before use and pour a couple of jugs of boiling water into the bucket, to warm the solution.

If you can get your hands on an etching tank and fishtank air pump, youā€™ll get the best and fastest results. (Pic attached.) The tank in the pic holds about 1.5 litres, but 1 litre is adequate.
Edit: The fishtank air pump blows air into a channel, and there are a series of small holes across the bottom of the tank that the air bubbles up from. This agitates the mixture well, so no shaking is needed.

PCB Etching Tank.JPG
PCB Etching Tank.JPG645Ɨ673 117 KB

#12

OldSteve:
anhydrous-ferric-chloride-powder.35840/]This page[/url] recommends 40% by weight, about half-way down.
I
Kitchen baking soda is what I use to neutralise it, (bicarbonate soda).

Quick an dirty method , keep dissolving until nothing more dissolves, this will give a saturated solution of about 42 baume..
Good for stainless steel but for copper remove the liquid and dilute with 1/3 water.

Bicarbonate to neutralise ???

You will spend a fortune that way, a lot is needed.

#13

Boardburner2:
Bicarbonate to neutralise ???

You will spend a fortune that way, a lot is needed.

Bicarb is cheap - I just throw a box in, give it a good stir, wait until it settles, then flush. :smiley:
(This only happens once every 5-10 years. I just keep re-using and re-using my mix, topping up with water as some evaporates.)

#14

Over here its a few quid ror 250 g but i can get washing soda for 1 per kg.

I emptied my tank a few years back ( 5 litres) and it took best part of 10 kg sack until it was neutral.

#15

Boardburner2:
Over here its a few quid ror 250 g but i can get washing soda for 1 per kg.

I emptied my tank a few years back ( 5 litres) and it took best part of 10 kg sack until it was neutral.

I don't worry about getting it right up to neutral. I just aim to take the edge off it, to avoid damaging my pipes. Once it gets into the general sewerage system, my (1 litre), is too dilute to seriously affect the overall acidity of the sewerage. And a ferric chloride mix isn't comparable to many acids. Spill it on your skin and it won't burn a hole, it'll just stain your skin yellow.
And I don't know about over there, but here in Australia the sewerage treatment plants are more than capable of handling 1 litre of slightly acidic liquid in God only knows how many megalitres of sewerage. Not a problem, as I see it.
I don't plan to drink the water afterwards. :smiley:

I think that there are large amounts of far worse things including heavy metals going into the sewerage systems anyway. No need to be overly-cautious.

#16

OldSteve:
I donā€™t worry about getting it right up to neutral. I just aim to take the edge off it, to avoid damaging my pipes.

Adequate dilution should be just as good (1 in 20 at least; thatā€™s two or three minutes of running water). All recent pipework is PVC which wonā€™t care at all anyway. Itā€™s more of being a good citizen. And you can take it down to the council depot and let them figure it out along with all the paint thinners.

Mind you, I havenā€™t thrown any out to start with that I recall. My bottle of ferric chloride (not to be confused with the steel wool, hydrochloric acid and H2O2 stuff) hidden somewhere started out as crystals, but has turned to liquid over the 20 years or so I havenā€™t used it. Frankly, I donā€™t propose to do so as the Chinese fabs - albeit slow - make it not worth any of the trouble.

If you must, a fish tank pump and air stone in hot solution is the way.

#17

dave-in-nj:
I do not know where your toilet water goes, but I would offer that the copper in the fluid is poisonous.
do not dump into a home cesspool.
any concrete will yield the base you need to counteract the acid.
if you want, you can pour on concrete. then allow it to evaporate.
the acid will etch your porcelain in your toilet and the copper will stain it dark red.
you could put it into a plastic container with rocks and put into the garbage.

aha well yes that's what happened when i washed the container after i dumped it, the porcelain and the steel became red so i had to wash it

what do you mean concrete ?

about your last option it seems interesting, but why rocks ? and simply take the fluid after i took of the pcb neutralize it with bycarbobate of soda and do throw in trash ?

#18

thanks everyone for all the advices and guidance i really appreciate it, well it seems not easy as i though so maybe i am gonna stop making my own PCB and take it to a manufacturer is better lol

it cost me 30$ for a 15cm x 12cm etching way, do you think it's good price ?

yesterday i had to use lots of ferric chloride powder spoons to make the copper dissolved from the board i don't know if these materials have any expiry date or i was doing it the wrong way ?

OldSteve you were talking about boiling before use, did you meant boiling the ferric chloride with water before putting the board ?

#19

It should take no more than 1/2 hr to etch provided its warm 40 deg best and the correct strength.

Concentration is important , just adding a few spoons to a bit of water will not do.

firashelou:
what do you mean concrete ?

about your last option it seems interesting, but why rocks ? and simply take the fluid after i took of the pcb neutralize it with bycarbobate of soda and do throw in trash ?

Cement is alkalii as is limestone rock.

Herdened concrete is of little use.

#20

For tray development i find full strength 42 baume is best as it readily allows the board to float upside down on the surface, agitation is not needed that way.

For air agitation it needs diluting with 1/3 water as the concentrate foams badly.