Dry Film Photoresist

Okay - I've got my etching solution all working great now on aluminium - thanks everyone who responded to my previous posts, the Copper Sulphate solution works a treat!

As background this is for through and partial etching of thin aluminium plates (.5mm to 1.5mm) where quality and detail are fairly important but exact results are not critical. They will generally be bead blasted and anodised afterwards so a couple imprefections can easily be hidden.

I would also like to, on the partial-through etching, know if there is an easy way to imprint ink in the etched surface. Is it a matter of pinting ink on top of it before removing the mask? Are inks resistant to basic solutions that would be used (sodium hydroxide?) to remove the mask?

My current issues now are around getting a good mask. To date I've been using standard photoresist spray from a can (bought from Maplins in the uk) but I tend to get some bubbles, specs, weak areas, etc. regardless of how carefull I spray it.

I am thinking of using dry film and a laminator but wanted to get any feedback to what was best, cheapest and available in the UK.

I've dealt with mega before

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and they have some equipment there but a roll of laminate is 80£ and if I can find a more economical source that I would preferr that.

Other then that is there any other photoresist system out there I should be looking at?

Thanks :)

Reply to
James Varga
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I have heard that Kodak is discontinuing the product, but for many years I coated printed circuit boards with Kodak Photo Resist by suspending the blank laminate on edge in a narrow tank filled with KPR and using a small stepper motor to slowly reel the board up out of the KPR liquid. The thickness of the coating is controlled by varying the speed of the motor. Eventually I changed over to dry film coated blanks with an improvement in quality and speed. Dry film coating is pretty much the standard today. Maybe you don't need to buy the gear at all if you can find a local PCB shop which will coat your blanks for you. Be careful using NaOH to strip the resist as this will also attack the aluminium. Try using a screen printing squeegy to push screen printing pigment into the partial etchings before stripping the resist. This works fine for narrow etchings like lettering, for large areas of colour you will need a screen. Dilute NaOH will not affect dry waterproof ink .

Reply to
Roger_Nickel

My wife, the artist, has been pondering Imagon for a while but hasn't tried it yet. Here's some info that may tell you if it's for you.

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Brian, in Cedar

Reply to
Brian Barnson

See

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They offer a photoresist that you can dip, sp>>

Reply to
Don Foreman

A recent edition of Model Engineer's Workshop (Aug/Sep 2004) had an article about using laser printed patterns ironed onto PCB.

Use your home CPU, and do away with all that wet photo claptrap!

Reply to
Airy R. Bean

I've tried ImagOn for etching, laminating it on one side at a time on the sheets to be etched (I used brass and nickel silver) and it works great. A hot roller laminator should work best. I only had a hot plate laminator so I had problems with the ImagOn wrinkling in humid weather. Note that the metal surfaces have to be absolutely clean and dry.

I bought my ImagOn at THE PRINTMAKERS' EXPERIMENTARIUM in Copenhagen

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but I don't know where in the UK it is to be had.

You may find some useful hints and tips on

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where Randy Gordon-Gilmore tells about his experiences with laminating and etching.

Reply to
Erik Olsen

There are a number of these used in the Printed Circuit board industry (PCB) Dupont & 3M make some films IIRC but from my bookmarks, one site stands out but you can find a lot of info here

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Browse around the rest of the site - lots of good info too

Good luck

Tom

Reply to
surftom

How about making a silkscreen mask by photolithography and then just silkscreening on paint as your etch resist? Would sure make the metal masking step much faster if you didn't have to do an exposure each time :-). The silkscreening supplies are readily available at hobby shops.

-- Regards, Carl Ijames carl.ijames at verizon.net

Reply to
Carl Ijames

I was thinking about that but hadn't had time to look into it yet - I have all the supplies here and have 10 screens just waiting to be stripped and used but hadn't gotten there yet.

What sort of ink is resistant to Ferric Chloride?

Reply to
James Varga

When I had a home business making circuit boards, I used an ink, NEPCO brand, I think that was oil based. I think any oil base paint or ink would work.

Most of my circuit boards were silk screened, but I did a few with KPR.

Earle Rich Mont Vernon, NH

Reply to
ERich10983

The main reason is cost. the laser printed stuff your talking about is way more expensive then a roll of photoresist.

Reply to
James Varga

Try calling MasterEtch. They are a father and son company that make Etching Machines, Lamintaor, and Light sources, etc.

Liam Dullaghan Masteretch Services Unit 10 Pywell Court, Pywell Road, Corby, Northants, NN17 5WA England Tel: 44 1536 266288 Fax 44 1536 266370

Glenn G. Houston, Tx

Reply to
m5bmw

Yeah - but you print off your first attempts off on cheaper paper to prove that you've got it correct.

You don't need UV lamp nor developer chemicals.

Reply to
Airy R. Bean

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