Toner Transfer - My First Shield

P18F4550

Very nice, could you post more details and maybe some pictures of the process you used to make the board.

Thanks

oo, nicely done :sunglasses:

I made a few PCBs using toner transfer, but never managed good results, the odd track mask would always lift...

I just noticed: Did you accidentally graze that button with a soldering iron? The top looks all melty ;D!

no, the button was too long so i cut it down, messy yeah

Oh, alright :).

Ok so as requested this is not a How To but a How I Did

Design the circuit, i use PCB Wizard

After printing the design to the photo paper carefully cut out the transfers, i print them on a laser printer with settings of paper type = transparency and density = 9 (highest)

Cut the copper board to about the right size leaving a bit extra to account for burring of the edges

Clean off the burred edges with a file and then i clean the board with Cif cream and a pan scourer, this is the important bit so take time to be sure the board is clean, when you rinse the cream off if the water runs straight off the board then it's not clean, if the water remains then it's clean

Dry the board and put it between a folded piece of paper and pre-heat the board, this ensures that any remaining water is evaporated

Next i use acetone (AKA Nail Polish Remover) to clean and remove and residue of Cif cream and grease

Drill two 0.6mm holes in the paper transfer, anywhere but be sure to drill the same two hole in both top and botom transfers

Lay the transfer on the board and with 0.6mm drill mark the board by drilling through the holes in the transfer, this is also a critical stage, be sure that the holes in the board are as vertical as posible or the pads won't line up on the bottom side,then using a couple of pieces of 0.6mm solid core wire to line up the transfer with the alignment holes in the board.

With the hot clothes iron tack down the top transfer then turn the board over an line up the bottom transfer the same as the top by using the two pieces of wire and tack this side down with thiron too

Slip the board between the peice of paper and apply heavy preasure with the iron set to hottest setting and no steam, hold the iron there for greater than 30 seconds, take the board out, carefull it's hot, turn the board over and apply the same preasure to that side, the metal plate is not nessisary but i use it as a heat sink, not to disperse the heat but to hold the heat and hopefully keep both sides of the board at an even temperature

Use the tip of the iron and work your way over the whole surface of the board until the traces under the paper start to show through, be very thorough here and make sure to iron every part of the transfer, turn the board over and do the same on that side

All traces show through, i think it's ready

Drop the board into some warm water, leave for 5 minutes for the paper to soak

Gently rub the paper with your thumb and the paper will seperate, the white substance left behind is the glossy coating of the paper, this will also rub off

When all traces of material have washed off it's ready for etching, notice there are a couple of bad spots in the toner, this might be because i rushed these pictures and didn't clean the board enough, or wasn't thorough enough with the ironing process, either way they can be touched up with fine tipped permenent marker pen

I hope this post will be of some use, this time i took more time over the alignment and the pads lined up perfect, so i guess time and patience is the answer.
A silkscreen can be applied with the same transfer method one the board has been etched.

You can get the toner transfer sheets cheaper on Ebay, I usually get 10 for £5 from China and they work ok.

Alternatively, I`ve read that pages from colour magazines with the glossy paper or some catalogues works really well. Haven't tried this out yet, but read a number of reports saying it works in various places.

Nice little guide, and I love the pictures!

I've always heard the toner transfer sheets aren't worth it, that glossy photo paper works just as well if not better than them.

I guess I wasn't too far off the mark with the "slop" remark...hmm.

:wink:

I still want to try my glass-panel process for UV positive exposure PCB making; maybe this summer...?

I admit this method is quick n dirty Cr0sh but the results work, this method would be useful for batch processing, i had though about the UV exposure method but there is the argument over whether UV Leds give out as much UV radiation as a black light tube, im looking to attach a drill head to my Roland plotter and get it to pre drill the holes before the heat transfer process making alignment much easier and effective, there are improvements to be made. Thinking on i could make an A4 Sized UV Led board and give your oven idea a go.

I was actually thinking for the UV exposure part using double-ended metal-halide bulbs, rather than LEDs. It would run hotter, so I would probably need fans, but there would be plenty of UV generated, and it would be easier to build than using an array of UV LEDs.

My method for transfer of the toner to the glass, if it works (it should, based on everything I've seen), would just allow the glass to be reused, whereas with using transparency "paper", it can get expensive; plus by being a hard material, if you set things up right with the glass, you could get nearly perfect alignment. The downside on the whole process is that it is much slower; it would not be something that would scale at all.

Now I am getting visions of how to homebrew a PCB resist plotter and I must stop...

:smiley:

I used to use the plotter to draw circuits straight on the board but it had issues, like the pen scratching the tracks and also the plotter was set for certain pen widths so it didn't draw pads very well, i've even tried spraying the boards matt black and using a laser fitted to plotter to burn off the paint, this actually worked but the beam was so narrow at the focal point it would take a week to make any sort of decent layout, for now im sticking to the paper, it's perfect for single sided boards, even smd layouts, just takes a bit of care when doing double sided

I prefer the UV method (print onto a transparent sheet, line it up, slide a sensitized board inbetween, expose, develop), but the toner transfer method is also a popular way of creating PCBs

I prefer the UV method (print onto a transparent sheet, line it up, slide a sensitized board inbetween, expose, develop), but the toner transfer method is also a popular way of creating PCBs

The problem with transparency sheets is that they cost so much; if you make a mistake printing one out, you may not catch it until you've wasted some expensive plastic.

I've heard that parchment paper used in baking is a UV transparent and cheaper alternative; my wife uses it for baking all the time, so I know that it is inexpensive by the roll, but I am not sure what sizes you can get it in sheets (probably standard commericial baking pan sizes, I would presume), but you would probably have to trim it to fit it into a laser printer.

Which is why I thought up the possibility of using pieces of glass, and transferring the PCB pattern onto the glass using an oven; this is something already done by people who etch glass - they transfer their pattern to the glass using an oven, then etch the glass with their chemicals, then remove the toner resist afterward.

Using glass as the UV masks would allow reusability while being inexpensive (not too mention you could easily make "standard" sizes with alignment holes for the PCB for perfect front/back alignments), the only problem is that it introduces an extra step in the process. If there were a way to easily get the pattern printed directly on the glass, it would be ideal.

Which led to me thinking about plotting/ink-jetting industrial sharpie ink onto the glass directly...

:slight_smile:

If there were a way to easily get the pattern printed directly on the glass, it would be ideal.

well if you can print on glass it would probably be more ideal to print direct on the pcb, which yes you can do with some model printers and inks

I tried Ink jetting straight onto a board, the HP DJ 400 draws paper straight through the printer so no bending is involved, as stock it will only take .8mm boards and needs modding to take 1.6mm boards, the obsticle i came across is that the ink is water based and as the print head boils the water to get the droplets it didn't work with endorsing ink which is permenent but not water based

There is a guy who has a copper product that is a very thin sheet of copper with adhesive backed. He has a special coating to coat the copper with allowing a standard lazer printer to print direct to copper. The copper is then glued to a blank FR4 board before etching. You have to be careful about soldering temperatures or the adhesive tends to lift.

Darn if I can remember the place now - If anyone is interested I'll try to find it. I like toner transfer method best now. Photo method I'm told works really good, but the coated copper PCB stuff was too expensive for me.

Ken H>

Photo method I'm told works really good, but the coated copper PCB stuff was too expensive for me.

If you go with the pre-coated PCB material, then yes, it is pretty expensive. What you can do, though, is get the positive resist material in powered form and mix it up with water, which is enough to coat many boards (regular PCB material), and it isn't really expensive.

Just a hint, you can print to PDF with "dopdf" and then import it to photoshop or something with 1200 DPI, then when you print there are no jaggies (and you can edit the board some more with nicer text, and smoothing or what you like.)

here is one done with pulsar pro toner transfer/ hp laserjet and laminator
(http://4.bp.blogspot.com/_cmcUouqPLaA/S3m45iMqWLI/AAAAAAAAAFU/1n5XkrPR62U/s1600/board.jpg)

well done on the double sided as well, now i think i will have to give it a try on my next board, i spend way too long trying to be clever and getting single sided to work with minimum bridges :slight_smile:

I still think someone should make laser sensitive CD shaped blank PCBs you could have a coating that gets burned by lightscribe, then you could make small (or larger with a hole in them :D) or round PCBs right in your rarely used CD/DVD burner!

Hi Defax,
The Jaggies are a result as you mentioned of low DPI, How do you scale pdf's, the last board I printed from pdf was out of scale, it was too small.

If I up the dpi at print time will that affect the scale or just make the layout smoother?
Your board looks smooth, no jaggies, and well designed, my first prefrence is for single sided, there is occations that call for double