I just ordered the sodium persulfate crystal junk from webtronics. It'll be here tomorrow along with my new soldering iron, 4000 resistors, heatshrink tubing, and some other things. I cant wait.

I dont know if the dry stuff works any better than the liquid. Also, I think the shipping might be different if it were a liquid chemical. but I dont really know.

I'd recommend the sodium persulfate because that's what everyone recommended to me, and it's clear so you can acutally see the etching taking place.

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Jeff
To the optimist, the glass is half full.
To the pessimist, the glass is half empty.
To the engineer, the glass is twice as big as it needs to be.

 

the sodium persulphate is just great because for 17 bucks you get 1 Kg, or 2.2 pounds. that's a lot... and you mix it with water so all told you get 4 liters of solution... and the being clear thing is great. plus it turns blue like windex as you etch so you can tell when it's time to mix some fresh solution.

if you really want to spend the money on press-n-peel go for it... but the staples picture paper works wonderfully and i paid 10 bucks for 30 sheets i believe...

also you may have trouble getting things done at kinkos. a lot of photo papers won't run through copiers. I know this because they tried it at my local copy place and totally jammed both their machines, had to call in an outside tech to come fix them. not good. I imagine the press-n-peel might not feed great either... at least with a laser printer you can easily fix jams and keep trying till it feeds right... at a store they'll probably get fed up and tell you they can't do it.

 

I just bought the Staples picture paper, and that stuff is great. Better than any of the other stuff I've tried.

One thing I can recommend is learn how to pour copper, or create ground planes in whatever designer you are using. I go threw ALOT less etchant now that I don't have to remove so much copper with each board.

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Mark Higgins

 

I agree. and it also helps the toner transfer because around large open areas with no traces, you tend to peel up sections of traces around the edge when you remove the paper, whereas if you have a copper pour there you don't have that problem. it's very easy to add a pour if you use eagle.

 

so go w/ the liquid eh?

what kind of paper is everyone talking about gettin @ office depot n places like that??

I guess i still don't totally understand this process. How does applying toner to the paper make it "peelable"?

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I'm no electronics god, i just talk too much.

 

It's just paper that you would use if you were printing photographs. It's pretty glossy so the toner will stick to it fairly well, but when you iron it to your copper board, it will still transfer.

when you iron the paper on the copper board, it makes the toner stick to the copper and not the paper. Thus leaving the toner on the board.

Hope this helps.

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Jeff
To the optimist, the glass is half full.
To the pessimist, the glass is half empty.
To the engineer, the glass is twice as big as it needs to be.

 

oooooooooooooooooooooooooooooooooooooooooooooooooo oooooooooooooooooooooooooooooooooooooooooooooooooo ooooooooooooooooooooohhhhhhhhhhhhhhhhhhhhhhhhhhhhh hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!!!!!!!

NOW it makes sense :lol: thank you very much jrz. the best that i could come up with was that the paper was sensitive to the laser and the laser somehow perforated the paper, and then u peel it off. :roll:

and its so much cheaper. just ordered some copper clad boards among other things, cant wait :lol:

What is meant then by saying to remove the "fills" and the "donuts" if all that happens is toner transfers to the board?

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I'm no electronics god, i just talk too much.

 

the paper coating is usually something made with clay... the coating tends to stick to the board along with the toner, just luckily for you the coating is a lot easier to get rid of than the toner... with the staples picture paper you can soak the board in water and peel of layer by layer, and then eventually scrub the coating off the board with a toothbrush... leaving just the toner.

 

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Mark Higgins

 

that site is exactly what i follow. good info.

 

oh, ok :lol:

one last and final question (hopefully), how do you get the toner off? Scrubbing it w/ brillo pads?

__________________
I'm no electronics god, i just talk too much.

 

On the subject of etchants, I used to be able to get ammonium persulphate. It is incredibly soluble, and if you add more persulphate to the solution when it gets a bit slow, you can restore its speed. After doing this a couple of times, it will be found that crystals appear when the solution cools after etching. These are copper sulphate and ammonium sulphate. Discard these, heat up the solution, add a couple of spoonfuls of persulphate crystals, and away you go again. No waste!
The solution will keep a LOT longer in the fridge. DO NOT keep it in a sealed container, as it will give off oxygen and build up pressure.
I don't think the sodium salt is sufficiently soluble to do this recycling thing.

 

I use a spray can of car part cleaner I have in the garage. It cleans everything off of the board after it's etched, then I scrub it a bit with some scotchbrite and wash it.

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Mark Higgins

 

lacquer thinner will take the toner right off. you can get a pretty big can of it at any hardware store for less than 10 bucks.

 

alrighty than. thanx everybody very much. This whole process has finally become clear to me.

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I'm no electronics god, i just talk too much.