simple but yet effective! you just saved my ass man. my medical officer and our janitor to include my commanding officer said how the hell did i etch the circuit without the procured solution?! thanks....

 

There must be more to this story than you are telling us, sounds interesting, please fill us in.

 

When diluting acid, the rule is "do as ya outa, add acid to water". An even simpler way to remember is to think how hard it would be to add swimming pool water to 5 liters of acid. BTW, this doesn't really matter with HCl but with H2SO4 it's a different matter, add water to conc sulphuric = steam explosion and you get to wear the acid.

Also, if the CuCl method works then the first time you use HCl + H2O2 the end product is CuCl. Isn't it?

Mike.

 

After thinking about it, I'm very dubious about the copper chloride method. If the method worked then the HCl + H2O2 method would keep working as the spent solution contains CuCl2 which should get consumed to produce CuCl which is insoluble (1.5g/Ltr). People who have tried this report a green spent liquid which suggests CuCl2 does not react any further.

Mike.

 

http://members.optusnet.com.au/~esey...uCl/index.html

That site has about all the information I think you'd need on the process. I also came across a PDF file that was some sort of information sheet about this process which is used in industry. I'm not an expert on the subject, but he does mention other factors in the process that would affect the etching ability of the Cupric chloride etchant, perhaps there's something else going on that's keeping it from working.

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It appears that the copper chloride method does indeed work. People that know a lot more about chemistry than I do discuss it Here.

Mike.

 

I use laser mailing labels to stick my toner transfer sheet to a larger sheet of paper.

 

I have always used clear (scotch) tape for that, and it's never been an issue.

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Originally Posted by bobledoux
I use laser mailing labels to stick my toner transfer sheet to a larger sheet of paper.

My tape is leaving some sticky residue on my PnP which in not an issue unless I am saving it for later use. I forget it is there and the sheets stick to other sheets. Will try bobledoux suggestion and use laser printing labels the next time. I guess this proves that all tapes are not created equal.

 

if anyone has any interest i did some molar calculating with this cemical reaction: http://rellermaa.pri.ee/HCl+Cu/HCl+Cu.html
(takes some time to load all the eqasions)
dodn't want to convert all of that to latex either...

i was trying to get the amunt of copper i can ech with 1kg of HCl. maybe in some time i'll make this amount in kg into amound in m^2.

PS the mw file ontop of the page is a maple worksheet if someone has maple

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If that doesn\'t help you, ask me... I might know better.

 

Usually I apply the tape at an angle so it is only covering the very corners of the press-n-peel piece (which is also beneficial in that I only need to cut my PnP piece slightly larger than the pattern, often 1/8" border or so), and then instead of trying to tear the tape off after printing, I simply use a razor knife and just cut off the corners of the PnP sheet that are covered by the tape. fast, easy, and no residue.

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There was a guy on eBay awhile back selling like 10 lb and up bottles of solid Ferric Chloride lumps.

Easy enough to turn that into etchant. At first I thought a pound of that stuff would make a lot of etchant. However, I did some calculations and saw that the ferric chloride is actually a very substantial part of the etchant's weight. It was still significantly less $ than buying etchant, but not a miniscule fraction of the cost.

One of the transfer sheet companies has been advocating dumping the etchant tank entirely in favor of applying the ferric chloride etchant with a sponge (while wearing gloves), literally rubbing it on. They say this etches a board far, far faster and in the end uses less etchant.

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.

 

The solubility of ferric chloride is about 92g/100ml according to wikipedia. That's just a hair over 2 pounds per liter, and if you do the conversion that means that 10 pounds of solid ferric chloride only makes about 1.3 gallons of etchant, which isn't as much as I would have expected! that guy must be selling that stuff for a pretty good price, because 4 liters of pre-mixed ferric chloride solution is about $22 from web-tronics.com for example, and 1.3 gallons is only 5 liters, so he'd have to beat $27.50 for 10 pounds... best price I see on there right now is $11 a pound, but that's 97% pure and might be fancier than the cheap hobbyist-grade stuff.

I will attest to the sponge method. A friend of mine etched a board at work with ferric chloride (I don't use it much myself, in favor of ammonium persulfate) and used a wadded up paper towel as a sponge, and the board did etch quickly and evenly, since you can see the progress and focus on areas that are etching more slowly. And of course, it doesn't require much etchant, which is very convenient if you prefer to just mix/pour out a batch of etchant, use it once, and then dispose of it, (instead of having a large tank of etchant that you keep filled constantly) since you will only be going through a small amount at a time that way. According to the CuCl etching page mentioned previously:
which would explain why the sponge method works so well for ferric chloride, but is not really helpful for persulfate etchants.

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Bobledeux:
I have a question about the pulsar etching system. Does it work that great? I have some of the paper, and I can't get the toner to transfer for crap! I've tried a dozen different copiers, and I've tried a clothes iron, and two differents heat laminators. Suggestions?

 

A good way to remember this is use the alphabet...A to W not W to A...
The explanation is simple..if you have a high concetration Acid (let's say sulphuric acid 10 mole) which would eat through any type of metal, if you would slowly dump the acid into water, the reaction can be controlled by the pouring of the acid into the water.

Let's say you dump the water into acid, then you would have a little bit of water reacting with a large amount of acid as the pouring process starts.
This is very dangerous because of the large amount of concentration of acid is going to react with every molecule of the water, giving off much heat.

I am no scientist but this was 8th grade bio-chem, which is basic reaction control.


Use this rule for adding acid into pretty much anything, espcially water.
-Jim