using ohp acetate to transfer pcb mask

Started by scaesic, August 23, 2006, 01:16:39 PM

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scaesic

i've done this quite a lot but i find it really difficult to get consistent results.

the tracks come off but half of it stays on the acetate, and in some places all of it.

Anyone perfected a method for using ohp prints?
higher higher heat?

i tried applying a lot of pressure while ironing but i found it just smudged the image.

Mark Hammer

I have a bunch of those left over from the pre-Powerpoint days and was wondering how well they might work.  Apparently not all that well (which is, I suppose the rationale for the development of PnP as a different type of acetate coating).

The question to ask is "How thick do you get the toner layer?".  Do you set the printer to its darkest or near-darkest setting, or is this difficulty experienced using default printer settings?

scaesic

i actually get someone i know who works in an office to print these off for me. No matter how much i ask them for "extra toner" or "dark contrast" setting, i still think it's just being printed using default settings. One day i'll buy a laser printer, then i can do what i like.

stm

Once I made a PCB using this method.  I had an inkjet print on white paper, went to a photocopy center and asked for a laser transparency of my print.  After ironing and peeling the acetate film carefully it transferred pretty decent to the very clean and polished copper surface.

What I've always fantasized about this method in order to ease toner separation from the film is to purposedly grease the film before printing.  How to do this rationally?  I guess using a piece of cotton with a light touch of WD-40 or maybe even a drop or two of olive oil might do the trick.  I don't think this will be enough to present a risk to the printer, but of course you try it at your own risk.  The principle behind is simple: surfaces with finger grease don't have good adherence for toner transfer or painting, thus the idea is to use this in your favour.

Cheers.

scaesic

thats a good idea.

at uni you can take your own transparencies in and have the print it on that. As long as it wasnt overly obvious that you'd "greased" it i reckon you could get away with it.

R.G.

The release sheet from pages of print-and-peel labels work wonderfully well.

I could never get overhead projector sheets to be reliable, even when I had a semi-infinite supply.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

brett

Hi
I've found that lightly oiling the copper surface of the PCB works really well.  Try a mist of WD-40, maybe combined with RG's label backing.
cheers
Brett Robinson
Let a hundred flowers bloom, let a hundred schools of thought contend. (Mao Zedong)

Paul Perry (Frostwave)

Didn't people once use the backing paper that adhesive labels came on? (I seem to remember the words Avery Labels, not that I ever saw any in Australia). I guess that paper backing would be designed to be "non-sticky" so that the adhesive labels peel off.
Yep, http://www.wd5gnr.com/pcb.htm thanks Google.

Gringo

I do all my pcbs using acetate, with more than acceptable/repeatable results.

I've posted my "technique" before, so a search should bring it up easily if you're interested; it relies heavily in a well polished copper surface, wiped with a cloth with some mineral spirit to remove any remaining stuff, a hot iron, careful ironing and a sudden temperature drop (from iron to cold water). All this learned from Mark's posts on the subject, of course.

Took me a couple of tries to master it ( mostly due to iron temperature/ironing technique/ironing time), so i always have spare transfers just in case, but it has served me well, and more important, it has served me cheap :icon_mrgreen:
Cut it large, and smash it into place with a hammer.
http://gringo.webhop.net

scaesic

i might try the wd40 idea, im guessing it just raises the temperature?