DIY PCB - Photo vs TTF

John R.

Fellow Parallaxians;

I'm going to be setting up to do some home made PCBs.· In looking at the viable options for getting the boards ready to etch, two choices seem predominant, TTF (Tonor Transfer Film) and photo sensitised boards with UV exposure.· Is it just me, or does the photo etch system seem just as easy (or easier) than the TTF systems?· About the only drawback to the photo systems I can see is the requirement for an exposure unit.

Is there something I'm missing?· Does anyone have an explanation as to why TTF seems more common in the DIY area?

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John R.
Click here to see my Nomad Build Log

Leon

Photo-etch works much better than TT for me. My home-made UV exposure unit is very simple and cheap:

www.leonheller.com/Pics/UV%20box.jpg

Some people use UV LEDs. They work well, but cost more than a couple of UV tubes.

You should join the Homebrew-PCB Yahoo group, there are lots of us loonies there.

Leon

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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle

Post Edited (Leon) : 6/2/2009 1:06:26 PM GMT

pwillard

As a counterpoint, I've had excellent results with Toner Transfer using cheap glossy photopaper as a toner transfer medium (GOOTEE method). The toner transfer is done using a heat laminating machine... made a big difference. Once you do it a few times... it's a breeze.

Print-laminate-soak-peel-etch-drill-done

www.fullnet.com/~tomg/gooteepc.htm

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There's nothing like a new idea and a warm soldering iron.

John R.

I don't doubt that TTF works, I'm just trying to figure out how it's "easier" than doing the photo etch thing. Enharently, photo etch seems to offer more options, and the ability to do finer traces and spacing.

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John R.
Click here to see my Nomad Build Log

Erik Friesen

I have pulled my hair out using the ttf, and personally think the results from photo etch is far superior. Plus, you can do double sided photo etch MUCH easier than double TTF.

LoopyByteloose

I have avoided the Toner Transfer Method for a few reasons - I don't own an iron and I have had previous trouble with transfer products that were rub on.

I don't use a special UV light, just a desk lamp for exposure.

And yet, I now find that I don't have the right printer to make a good transparency as my HP Inkjet died and I mistakenly replaced it with a Canon. The Canon ink beads up on a transparency.

I next went to a Fuji-Xerox Laser printer and was thinking I could do the transparencies on that. But they are not dark enough for the exposure to light sensitive emulsion.

And so, I either must by an HP inkjet to go back to what did work OR buy an iron to try the TTM with my Fuji-Xerox printer. Maybe, I should be really using UV with what I can print.

The main point here is that people go with what they find it easy to have success with. The printer you own may actually decide which process works, if any. Some toners don't transfer well.

Pulsar produces a system that seems to work very well with TTM, but I have never used it. Others love to be cheap and use the glossy covers of magazines without trouble. One should do some test runs and expect to learn by trial and error. Writers have a way of saying their process is mindlessly easy when there are details yet to consider.

I personally like the photographic transparency for crispness. That may be necessary with finer pitch surface mounted chips and not easily achieved with the TTM. If I were not in Taiwan, I could have a blueprint shop make a transparency from a laser printed copy. I cannot find a local shop to do so.

But also, others are using a milled CNC process that avoids both these etch processes and the chemicals for small runs. That has the advantage that the small milling machine can make small robotic parts when not being used for boards.

BTW, I use Eagle software and am very satisfied with it for my own boards and for boards I have sent out.

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Ain't gadgetry a wonderful thing?

aka G. Herzog [noparse][[/noparse] 黃鶴 ] in Taiwan

Post Edited (Loopy Byteloose) : 6/5/2009 12:02:17 PM GMT

Leon

Try Jetstar film, sold by Mega Electronics (UK). I use Jetstar Premium film with my cheap HP printer. Both are stocked by Farnell.

Leon

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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle

Erik Friesen

I use an HP inkjet with inkjet transparency, which is basically a roughed up transparency to allow the ink to dry. For ground planes or super fine stuff I like to double print and line up, for a total of four for two sided boards. Otherwise I get pinholes in my ground planes.