Ferric Chloride Powder ???

[ChrisGreece52]

Hello after i saw that is not very convenient to order pcbs premade i decided to etch them with ferric chloride.
I found the ferric chloride in a powder and in a liquid form.The thing is that the powder is a lot cheaper but i dont know.
1)how to use it
2)how to desolve it
3)what i should desolve it in ...
please help THANK YOU.

[grumpydoc]

I found the ferric chloride in a powder and in a liquid form.

The powder is the yellow stuff, right? (there are two forms)

1)how to use it

Prepare PCB with resist (draw with permanent marker, toner transfer, tape, UV resist - whatever takes your fancy), pour ferric chloride solution into a plastic container, put in PCB, leave until the copper has dissolved where there is no resist, remove, rinse and dry.

It will go faster if you warm the solution to 30-40^oC and/or agitate the board.

2)how to desolve it

I think it's about 250g of ferric chloride to 1L of water

3)what i should desolve it in ...

Water. Tap is OK, deionised slightly better.

[IanB]

Before you start you should make sure you have something to store the solution in. Once you have the liquid you can keep it and use it several times before it is exhausted. You will need a plastic bottle with a plastic stopper, and a plastic funnel to help pour the liquid into the bottle. Keep the liquid far away from anything made of metal, and make sure to wear a protective apron/overalls, safety glasses and rubber gloves while handling it. The stuff is nasty and will corrode and stain anything it touches.

An important rule: always add the ferric chloride in small amounts to water. Never add water to ferric chloride! Dissolving or diluting ferric chloride produces a lot of heat and there could be steam and fizzing and splattering all over the place.

To make a ferric chloride solution for use, you will need a large plastic jug. Place about 250 ml of water into the jug. Measure out about 100 g of ferric chloride powder into a separate dry container. Add this powder slowly to the water in the jug using a plastic spoon, one spoon at a time. Stir to dissolve before adding the next spoonful. Don't leave undissolved powder sitting on the bottom of the jug.

When you have finished dissolving the powder, allow the jug to cool down and then carefully pour it into your plastic bottle using the funnel and cap the bottle.

To use it for etching, use just as much of the solution as you need to cover the circuit board in your etching tray. You don't need to use all of it at once.

[ChrisGreece52]

I found the ferric chloride in a powder and in a liquid form.

The powder is the yellow stuff, right? (there are two forms)

1)how to use it

Prepare PCB with resist (draw with permanent marker, toner transfer, tape, UV resist - whatever takes your fancy), pour ferric chloride solution into a plastic container, put in PCB, leave until the copper has dissolved where there is no resist, remove, rinse and dry.

It will go faster if you warm the solution to 30-40^oC and/or agitate the board.

2)how to desolve it

I think it's about 250g of ferric chloride to 1L of water

3)what i should desolve it in ...

Water. Tap is OK, deionised slightly better.

First thank you
the powder is the solid form of ferric chloride (little balls ) not the liquid one.
Second thanks for the info
also i have to make a few more questions
1 : shall i make small batches and then dispose it or just make a pretty large batch and then store it after every use.
2 :shall i dispose it in the sink with a lot of water (not to harm the copper pipes) or is this wrong

[4to20Milliamps]

Hello Chris,

4 to 1 distilled water to powder ratio, you should probably be aware of the safety issues associated with etching pcb's> wear proper clothes, eye protection, be extremely cautious about getting any of it on your skin and have a well made plastic container with a lid to keep it in.

You should take some time and read on the internet, there are also other ways to etch boards with different chemicals:

Cupric chloride:
http://www.instructables.com/id/PCB-Etching-Solution-Cupric-Chloride/

ferric chloride:
http://en.wikipedia.org/wiki/Iron(III)_chloride

read #2 in "preparation"

Hydrochloric acid is easy to get, but you have to be extremely cautious about handling it, it can cause severe chemical burns.

Also you can use Vinegar, salt, and hydrogen peroxide, which makes a fairly weak etchant but with air from a pump you can speed things up a bit.

http://hackedgadgets.com/2011/04/11/hydrogen-peroxide-distilled-white-vinegar-and-salt-as-a-pcb-etching-solution/

[ChrisGreece52]

Before you start you should make sure you have something to store the solution in. Once you have the liquid you can keep it and use it several times before it is exhausted. You will need a plastic bottle with a plastic stopper, and a plastic funnel to help pour the liquid into the bottle. Keep the liquid far away from anything made of metal, and make sure to wear a protective apron/overalls, safety glasses and rubber gloves while handling it. The stuff is nasty and will corrode and stain anything it touches.

An important rule: always add the ferric chloride in small amounts to water. Never add water to ferric chloride! Dissolving or diluting ferric chloride produces a lot of heat and there could be steam and fizzing and splattering all over the place.

To make a ferric chloride solution for use, you will need a large plastic jug. Place about 250 ml of water into the jug. Measure out about 100 g of ferric chloride powder into a separate dry container. Add this powder slowly to the water in the jug using a plastic spoon, one spoon at a time. Stir to dissolve before adding the next spoonful. Don't leave undissolved powder sitting on the bottom of the jug.

When you have finished dissolving the powder, allow the jug to cool down and then carefully pour it into your plastic bottle using the funnel and cap the bottle.

To use it for etching, use just as much of the solution as you need to cover the circuit board in your etching tray. You don't need to use all of it at once.

Thank you for answering my questions but the" DO NOT ADD WATER STRAIGHT TO FERRIC CHLORIDE " made me a bit nervous.Also if i disolve one spoon at a time will the container melt due to the high temperature?

[ChrisGreece52]

And while i was posting this issue another one occured.
The Greek store i found has 5 euro shipping fees and a 5 euro fee for the payment (i dont know the word but it means that when the item arrives you pay it also has bank accounts available but i will check this section out late)
and if those where not enough for you the ferric chloride balls is out of stock ....
what a bummer  where can i find ferric chloride online at a reasonable price (because ebay is a bit crazy)

[IanB]

See if you can find ammonium persulfate. It is more pleasant to handle than ferric chloride, and works just as well:



For supplies, you might check out not only electronics supply places, but also arts and crafts supply places. Copper etching is used by artists as well as by electronics makers.

[ChrisGreece52]

http://www.ebay.com/itm/New-200g-bag-Process-Reagent-Etchant-for-Copper-PCB-Environmentally-Friendly-/290815868467?pt=LH_DefaultDomain_0&hash=item43b5f9fe33
The only thing i could find ... does anyone know what is it ?

[mariush]

Farnell has all kinds of substances : http://uk.farnell.com/ferric-chloride

Also get the brand name and product code and google it, you'll find plenty of uk and eu stores that stock them.

[c4757p]

See if you can find ammonium persulfate. It is more pleasant to handle than ferric chloride, and works just as well

  Sodium persulfate is similar.

The only thing i could find ... does anyone know what is it ?

That? That is industrial sludge that somebody accidentally dropped copper into and discovered that it dissolved. Just a guess. Can't think of any other reason not to label the contents.

[grumpydoc]

Thank you for answering my questions but the" DO NOT ADD WATER STRAIGHT TO FERRIC CHLORIDE " made me a bit nervous.Also if i disolve one spoon at a time will the container melt due to the high temperature?

That's why I asked whether you had the yellow stuff.

That's the hexahydrate, it doesn't get hot when you add it to water - in fact it helps to warm the water before you try to dissolve it. Also you probably won't encounter too much unpleasantness if you add the water to the solid (though it's best to do it the other way round).

It's also possible to come across anhydrous ferric chloride (or, perhaps, order it accidentally online) - that's rather nasty stuff. Deliquesces releasing HCL mist** and gets very hot when you dissolve it in water and is generally much more dangerous to have around.

** so wikipedia says, I've no reason to doubt it but thankfully I've never tried to handle the stuff myself.

Keep the made up solution well away from anything metal but it can be stored and re-used until it doesn't etch any more - you'll notice it taking longer and longer to etc your boards. How long depends on your board design.

The used solution needs to be disposed of correctly as it is an environmental hazard.

As others have pointed out there are other etchants which have different, perhaps better, properties for home etching.

[A Hellene]

Chris, if you reside in Athens you can find ferric chloride in solid 'peas' form at the down-town industrial chemicals shops, located at Mainandrou St. and Geraniou St. (at the end of Sophocleus St., just before Piraeus Ave.).

Meanwhile, you can read what I have written on the use of ferric chloride (even though the whole thread is worth reading) in another discussions community.


-George

[mikeselectricstuff]

It's also possible to come across anhydrous ferric chloride (or, perhaps, order it accidentally online) - that's rather nasty stuff. Deliquesces releasing HCL mist** and gets very hot when you dissolve it in water and is generally much more dangerous to have around.

This is typically a dark green/brown powder. Not only is it nasty, when dissolved it won't even etch - you need to do something else to it (I don't recall what) to turn it to a form that works.

Incidentally, PCB supplier Mega in the UK have said that they can't get the hexahydrate (yellow) granules any more as the manufacturer has stopped making it, and they can only supply liquid now.
 

[ChrisGreece52]

Chris, if you reside in Athens you can find ferric chloride in solid 'peas' form at the down-town industrial chemicals shops, located at Mainandrou St. and Geraniou St. (at the end of Sophocleus St., just before Piraeus Ave.).

Meanwhile, you can read what I have written on the use of ferric chloride (even though the whole thread is worth reading) in another discussions community.


-George

Thanks George but you make a mistake here being from Greece does not mean that i live in Athens
but thanks for the advice.

[IanB]

This is typically a dark green/brown powder. Not only is it nasty, when dissolved it won't even etch - you need to do something else to it (I don't recall what) to turn it to a form that works.

I think it will etch, but you don't want to make the solution too concentrated. It needs to be a bit diluted before it will etch well.

[mikeselectricstuff]

This is typically a dark green/brown powder. Not only is it nasty, when dissolved it won't even etch - you need to do something else to it (I don't recall what) to turn it to a form that works.

I think it will etch, but you don't want to make the solution too concentrated. It needs to be a bit diluted before it will etch well.

It was many years ago when I was at school, but it definitely would not etch - I asked my chemistry teacher about it - don't recall what, but it needed something adding before it looked and acted like normal FeCl etchant.

[Psi]

I would recommend against using Ammonium Persulphate.

It only works when it's very hot and doesn't stay hot for long unless you put the container into a large bucket and surround it with boiling water.
The heat also tends to melt off thin traces when using the toner transfer method.

FeCl or HCL+peroxide work much better.


I've never tried Sodium Persulphate, so dunno about that one.

[ChrisGreece52]

I am not sure what to choose... i would go with ferric but thething its the fumes...

[mikeselectricstuff]

Normal ferric produces negligible fumes at normal working temps (say 50 deg.C) . I've not tried any of the alternatives, but IME the only downside of FeCl is that it stains anything it touches.

[IanB]

I am not sure what to choose... i would go with ferric but thething its the fumes...

Ferric chloride solution doesn't make any fumes, it's quite docile. You just have to be careful about the way it will corrode and stain anything it touches, so you must use only plastic or glass containers. And don't spill it or splash it...

[Psi]

You can microwave FeCl to warm it up as long as you're careful and do it slowly.
Don't do it in a sealed container etc..
And you shouldn't do it in a microwave used for food.

I'm not sure what temp FeCl starts to boil/fume but you really want to avoid that which is why i say to do it slowly.

I've warmed it up in a old 600W microwave many times without issue.

[ftransform]

I dissolve a 1:2 ratio of ferric chloride to water by mass and use the sponge dabbing method (double gloves, fan, outside), where you dab the PCB with a soft sponge.

Takes a bit but you only need a little bit of etchant, no tanks etc (free electrons method)

[ChrisGreece52]

Well thank you for your suggestions and sollutions all!!!
I loved the moment i read it has no fumes and then the thing that the only danger is that corrodes metals and stains everything.
Now as for the microwave thing i am not sure about it becuase i will screw things up if i attempt it.

[amyk]

http://www.ebay.com/itm/New-200g-bag-Process-Reagent-Etchant-for-Copper-PCB-Environmentally-Friendly-/290815868467?pt=LH_DefaultDomain_0&hash=item43b5f9fe33
The only thing i could find ... does anyone know what is it ?

Looks like one of the persulphates as it mentions that oxygen is evolved. Someone who knows Chinese can say more about what the label says.