An idea for etching circuit boards and enclosures.

[NakedApe]

I've always struggled with ironing toner onto my circuit boards to etch them, it just seems that no matter how hard I try there is always going to be a bit of smudging, harming ther resolution.  Now that I want to try etching an enclosure, It would be nice to have a way of doing it without ironing toner on. 

I know there are boards for sale that are coated with a photosensitive layer that can be developed after being exposed through an acetate positive.  I also know that t-shirt silk screening uses a kind of photosensitive emulsion to prepare their screens, and they can get a great amount of detail with this method. 

My idea is to try coating the board or enclosure with the emulsion, then exposing a design directly on the board or enclosure.  The result would be a positive stencil that will hopefully be resistant to the ferric chloride, since it seems to be some kind of plastic.

I'm going searching for a place to buy the emulsion, and hopefully I will report back with some tests as soon as I can. 
In yhe meantime, has anyone tried this? If so, is there a good reason why not to do it?

Happy etching.

[duck_arse]

years ago, this process used to be called "Riston". a full range of chemicals, pre-coated boards and acetate sheets were available, and you could expose to the sun or a uv tube/bulb. keep searching.

[Beo]

I think getting the enclosure truly sanded flat is the main challenge. Ironing works much better and consistent then. It takes a lot of elbow grease and can eat up sandpaper to get a box truly flat. Has anyone priced local metalshops to see how much it would cost to have them sand/grind flat tops onto enclosures? I'm thinking if you went in with a batch of 10 or 20 enclosures, it might not be too expensive.

[~arph]

Erm, you have electrical sanders.. I use one all the time for enclosure sanding, not much elbow grease needed 

[NakedApe]

I can usually get a mirror finish on the metal before I iron, and even then it gives me problems... in any case, I just picked up some photo emulsion from a local silk screening shop and I´m going to star experimenting tonight with some pcbs and a piece of aluminum I have lying around. Ill post some results when i have some

[Tony Forestiere]

I had not heard of this method, so I did a bit of research.

Are you planning on using a modification of this method? Looks feasible for our purposes. Good luck, and let us know how it goes.

*edit* darned "s"   I do miss the preview option.

[NakedApe]

I had not heard of this method, so I did a bit of research.

Are you planning on using a modification of this method? Looks feasible for our purposes. Good luck, and let us know how it goes.

*edit* darned "s"   I do miss the preview option.

Yes, except I have coated the emulsion directly onto a piece of copper clad board and a couple of pieces of aluminum, I´m going to try burning the designs into them as soon as they are dry!

[NakedApe]

So far, my results show that this is not going to work. As soon as I put the developed piece into the etchant it just dissolved away.   Oh well, i guess I´ll have to make some shirts or something.

[Tony Forestiere]

Bummer. I thought there was potential to that idea. Thanks for the update and taking the leap.