Photo resist for double sided photo etching?

[Chuckt5]

I'm wanting to give a try at making my own photo etched parts. I think I understand the process (for the most part) but one thing that I'm having a tough time with is finding positive photo resist spray to apply to the metal.

Does anyone out there use the photo resist film or paint and if so, what's your feedback on it?

I want to be able to do part etching with double sided parts, so I need something that will give me good resolution. Any ideas?

Thanks as always (and happy new year)
chuck.

[uncletony]

I've only used the micromark system where the emulsion is applied with a lamination machine. Results can be pretty decent and usable but are totally outclassed by pro PE output from bureaus.

[Chuckt5]

That's what I thought. From what I've read, it seems the best resuts are acheived by:

-applying CAD pattern for the part to a clear film
-using a spray on positive photo resist applied to the metal
-transferring the pattern to the metal with a UV light and developing the pattern
-then using the direct etch method to etch away the unwanted metal

Professional outfits use etchant applied via spray as the part is rotated, but making a spray set up for home application gets pretty complicated and pricey. I haven't tired the direct etch method yet, but from all reports, it's much better than a tank with bubbler or rocking the part in a tray to make your parts.

Thanks for the feedback, C.

[uncletony]

Yes. From my experience, by far the sketchiest part of the process in the micromark kitchen sink kit is the actual etching in the tank to get uniform results with a bubbler and rotating the workpiece every ?? seconds/ minutes. I think the rest of the system is pretty solid for a home setup -- printing the neg on clear film, applying emulsion to the metal, exposure, developing, etc.

[Chuckt5]

That's good to hear.

Have you read about the direct etch method of using a sponge and small amount of Feric Chloride to remove the unwanted metal? It seems to overcome the shortcomings of the bubble tank with all it's waiting and inconsistent etch results.

Glad to hear the other parts of the micro mark system work well though. Using a film photo resist applied with a laminator is my plan B if I can't source any spray on resist.

[uncletony]

Have you read about the direct etch method of using a sponge and small amount of Feric Chloride to remove the unwanted metal? It seems to overcome the shortcomings of the bubble tank with all it's waiting and inconsistent etch results.

I haven't -- but yikes. The stuff is nasty enough when handled at arms length...

[Chuckt5]

I agree, but using this method allows you to etch with only an ounce or so of ferric versus a trays worth and clean up is much easier. Just throw the sponge and gloves in a bag and your done!

Looks like I need to find some positive photo resist film instead of the spray I was hoping to use after all. I found one place in Germany that was willing to ship two regular sized spray cans of resist to Canada for only 300 Euro's! I guess it being a hazardous material drives up the shipping costs. 

So the film offered by Micro Mark has been good to you?

[ALBATROS1234]

let us know your results

[Chuckt5]

Will do.

I need to do the artwork first, then I'll get back to you all.

[Alexis]

For the spray you are looking for . You can always try shops that cater to guy's who make their own circuit boards ?




Terri

[Chuckt5]

I've tried that but for some reason photo resist spray is almost impossible to get in North America. I'm going to try and source photo resist film which seems easier to get.

[uncletony]

I've tried that but for some reason photo resist spray is almost impossible to get in North America. I'm going to try and source photo resist film which seems easier to get.

Awhile back you asked about whether the film (micromark) has been good to me -- the answer is yes, as long as you are dealing with small areas it works fine; I think other aspects of the job are much trickier (getting perfect registration, exposing properly, developing, and of course the actual etch which is by far the trickiest step.)

[Chuckt5]

Thanks Bo for the heads up.

I just need to find time between work, taking the kids to sports, helping out with boy Scouts and the constant jobs around the house to get the artwork done!

[steveb]

I've made a few 1/25 automotive carburetor linkage parts by making 2 sided artwork & printing it on Press-n-Peel Blue film. http://www.techniks.com/how_to.htm

Print the artwork onto the film using a laser printer, & then iron the artwork onto the brass sheet. Registration can be a pain, & too much pressure on the iron can make the resist lines wider than scale, but it's a relatively cheap experiment if you have access to a CAD or vector program & a laser printer. I poured Ferric Chloride into a film canister & submerged the brass. While the results were not as clean as commercial etchers, I still came out with some one off, usable pieces.




Steve

[Chuckt5]

Looks good to me!

Thanks for the info.