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Feeling pleased with myself...

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throbscottle

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My toner transfer technique has improved a lot since my "squashed caterpillar" as tvtech called it. I just made this set of little adapter boards, 8 and 16 pin soic to dil (admittedly 0.4" pitch) and ssop to dil. The tracks on the 16pin one and the ssop one are 0.015" or 0.381mm, the spacing between them is 0.01" or 0.254mm. I reckon I could get down to under 0.01" wide with no problem, at least for short segments anyway. Couple of shorts on this board, no opens, so minimal adjustment required.

I'm now using cheap yellow toner transfer paper from China - it seems to be like label backing paper but with a polymer on the shiny side rather than wax. Lowering the heat of the iron helped too. The challenge, I reckon, is getting just the right temperature, to be able to improve it further. A couple of tracks seemed to get squished out a bit (you can see on the photo where I trimmed them back) so I might try lowering the printer resolution.

The pins come from an old header plug pulled from a board. I put the thing on the breadboard and put the pins through to hold them whilst soldering. Worked pretty well and I didn't melt the breadboard!
 

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The Toner xfer method starts to get challenging with SMD parts and larger boards, say > 4" per dimension. What happens is the board can warp a bit during localized heating and 'curve' thus making the ironing process tricky due to loss of flatness. This means u need to use the edges of the iron and press harder, which sometimes causes traces & pads to become blurred and require touch up before etching. Vias can 'lose' their centre holes when this happens.
I mostly have this problem when routing a 12 mil trace under a 0805 part, or when spacing between parallel traces is < 16mils.

The alternative is to not press as hard and risk improper toner transfer, which then needs more touch up with nail polish and a toothpick. That can be quite a headache.

One day I hope to see a Xerox wax printer made for heavy card stock with a straight thru media path!
For now I am looking at this as my next PCB fabbing upgrade:
https://www.instructables.com/id/Double-sided-PCBs-with-a-laser-cutter/?ALLSTEPS
 
^ That happens to me when I make Big boards, even smaller 2x2 boards can be challenging. I use staples brand photo paper, but these days Ive reverted to using OSHpark. I do occasionally still use the toner method, but PCBs from a fab house are so much nicer.

BUT DIY'ing it comes with the sort of self satisfaction that nothing else can give you, especially when you peel off the paper and you see beautiful traces come out before you. Its that feeling you get when you peel off the plastic from a brand new screen.
 
Overclocked, I have to disagree, the feeling is not remotely similar! Entirely "YES" with added *wow*, whereas peeling plastic off a new screen results in *gooeyness* and *ooohh*.

I'll be able to see how this goes on a larger board soon when I've finished testing on breadboard (hence the adapters)... That little ssop is a digital potentiometer, I want to check it works as expected!
 
There are several people on ebay selling A4 size toner transfer paper for about 16 cents a sheet. It was suggested to me by another member on chat. I have some but have yet to try it. Curious about how it compares to pulsarProFx paper. Like others here I mostly send my boards out to OSHPark.
 
Purely from what I've read (I can't afford the pulsar paper) this is way inferior by comparison. Still getting imperfections, also with too much heat some toner gets absorbed into the paper rather than stuck to the board. Still a vast improvement on anything else I've tried (except a lucky shot with dextrin coating)). I don't know what else to compare it to, having never actually tried label backing. Definite some sort of coating of plastic-ey stuff on this paper though - it looks kind of stringy. I should look at it through the Very Strong Magnifying Glass.
 
Throbs:

Your boards look pretty good. www.proto-advantage.com, sells LOTS of adapters (assembled, unassembled and with Digi-Key components. Their assembly technique is a blank PCB with holes to hold the pins.

The last time I did a board, I used the DOS Easytrax program and photo etching. I had access to an IC photolithography lab. So, making resist coated boards was easy as long as they were small. Resist was spin-coated. Exposure was done with a Karl Zeiss Mask-Aligner. Probably something like a 3" x 3" max exposure, but the board could be moved.
I found some translucent Polyester paper lying around and it was superb. I printed a strange output from Easytrax which included the traces in an outline form and the component placement and glued that to the top of the board. I was really pleased. I pulled off double-sided.

The time before that I used the "tape method" and the sun for exposure. I did send some taped boards for fab.
 
What can I say? "budgetary constraints"...
Aeons ago, I used to trace my design onto the board using carbon paper, then use that rather bad impression as a guide to fix dry transfers. Took a long, long time for anything complex. Never been able to afford to do photo etching...
 
You did well.
I do photo etching on a budget, evrything is self made.
They did make a printer with a flat bed apparently, it was meant for printing on cd's, but I've never seen one.
 
I have an Epson Artesan 800 which will print on CD's. They said my idea for a minor change to their scanning software was a good one, but it never materialized.
I'd like to have a prefix+digits+suffix. So I could do Page001a and Page001b etc, so it would be easy to scan each side and combine so I could easily scan double sided originals. I even talked to someone, In one ear and out the other.
 
I can recall, in my country , in my teens, when USD couldn't be bought and was illegal to own unless you were a gov't approved company (3rd world country) . I couldn't hope to get materials to do PCBs and all my parts came from scrapping transistorized stereos, radios and TVs.
One day, a family member visiting the country gave me a hand cranked PCB drill from radio shack. I turned that into an electric unit using parts from a toy electric car. RPM was equal to the speed of the car's wheels but had good torque.
For resist, I wrapped transformer wire (#3o awg or so) around a cleaned out Zinc battery can (size C). This heated & melted vaseline (12V power) which was applied as resist using a dipping ink nib, also heated by transformer wire @ 12V supply.
For copper clad, I made a 6" x 4" lead plate from a melted car battery and used it to electroplate copper obtained from copper 5 cent pieces (local currency). The plating had to be kinda thick to allow me to peel it off the lead plate.
Then using laminate material (brand name Arborite) I glued the copper sheet with Evo stick glue as a single layer backing. 1/16" HSS bits were the smallest I could buy locally so that had to work. Etchant was mainly nitric acid.

I made quite a few projects like that and I kept a few as mementos. The drill still works! It reminds me how far I have come since then.
 
Excellent, surprising what you can do when you dont have the readies, when I had no cash I just put together circuits point to point.
 
Ok, I broke down and ordered this:
https://www.amazon.com/Apache-AL13P...8&qid=1372796999&sr=8-1&keywords=apache+AL13P

The hot iron process causes too much heartache. I just made a small 2" x 1" smd PCB...and I still had to touch up AND the erratic trace thickness caused some parts to over etch...etc. I still used it...and it cost me 4 hours debugging due to board faults I could not see.

I based the purchase on this advice:
https://www.pcbfx.com/main_site/pages/start_here/laminator_info.html

Hopefully my double sided boards will be of a higher quality. I still will use the magazine paper (parts express), but I'll tweak the laminator's temperature and pressure to get the best results.
 
That was a most interesting read. I've used a combination of iron + cheap laminator, so the iron gives heat and the laminator gives pressure, but the exit slot in the laminator is a bit small and the carrier tends to sort of grind along the plastic. Plus I'm a bit worried with small boards it will bend the rollers - and I only seem to make small boards...
 
No, got loads left thanks mate :) I don't do many and they tend to be very small.
 
No, got loads left thanks mate :) I don't do many.
 
Well, it's looking like I may have to do a tutorial after I get the laminator properly setup for the interested parties.
 
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