Often when making embedded computer systems you'll need to connect a bunch of devices such as resistors, external memory, USB plugs, analogue sources, power supplies and so forth to your microcontroller.

How you do this is up to you, however if you're like me and using advanced devices that come only in surface mount form then a PCB is the only way to go!

Designing a custom PCB is simple. However getting it made can be complicated. If you're lucky you know someone at university who can slide your project under the table when no one is watching. If you're less lucky you have to pay someone to make it and prices for one-off boards can be prohibitive.

But if you have access to a laser printer, some glossy photo paper and a domestic iron then you're in luck! Just follow my step by step guide!

Recommendations for making artwork
Oddly enough, the finer your board, the more likely it is to succeed!

Highly recommended is a polygon plane (aka a ground plane), created with 45° cross hatching, 12-15mil lines at 25-30mil spacing. Don't turn on the option to remove "dead copper". Net-to-net spacing should be 12-20mil, although I have successfully etched boards with 0.5mm track pitch.

Any text should be mirrored (if on the bottom layer) but the final pattern should be printed without mirroring or negative options enabled.

The choice of paper is important; I'm using Kodak "Picture Paper" which at 190gsm is horrible! What is important is that the paper is shiny and smells funny. This allows us later on to remove the paper while leaving the toner attached to the board.

Why is a finer pattern better?
I've found that when transferring the toner to a PCB, areas without any toner don't stick to the paper. Once the iron is removed the expanding gases and different expansion/contraction rates of the paper & board cause areas without toner to buckle and produce bubbles. The upwards pressure of these bubbles on the surrounding toner can act to lift surrounding tracks, causing annoying voids on the completed board!

By making the space between tracks very fine and using a ground plane, this can easily be avoided.

Another point is to use a cross hatched ground plane rather than a solid one, as the individual tracks in the cross hatching appear to grip better than one solid area of toner. They also seem to print better on older priters. I've found that if for any reason part of a solid ground plane should fail to stick to the copper and is lifted with the paper when removed, it will tend to take surrounding areas of the toner with it as well. By using a cross hatched ground plane I suspect this would be less likely.

Step by step guide

Part way through removing the paper.
Although quite an involved process it can all be done in a night and the result can be very good indeed! It just takes a bit of patience and some experimentation to determine the best process.

An example of what is possible — the finest tracks here are 0.25mm wide with even less space between them!

Completed SMT board


Friday Jun 3 2016, 7:08pm ksnuonOhGa says...
tesco pharmacy viagra cuanto dura el viagra en hacer efecto sveden viagra kaufen viagra para doença pulmonar where to buy viagra in kampala buy viagra online next day delivery cheap viagra online from india what happens when you take two viagra quanto dura l'effetto del viagra online herbal club viagra order viagra online free shipping tengo hipertension puedo tomar viagra buy viagra uk chemist viagra feminino em fortaleza comprar viagra en usa viagra oorspronkelijk sale of viagra in uk el viagra funciona con alcohol viagra echantillon gratuit costo del viagra in farmacia italiana female viagra buy buy sildenafil online Pittsburgh viagra available bangalore eshop prix génériques viagra viagra prof... comprar viagra requiere receta medica viagra trial sample viagra shooter recipe cheap uk viagra suppliers emedicine viagra overseas drugs viagra hace daño tomar mucha viagra viagra like over the counter viagra jelly in uk best place to buy viagra australia what are the side effects of taking viagra fonctionnement du viagra viagra uk muscle cheap viagra trial pack why does viagra give you heartburn
Tuesday Mar 27 2012, 4:44am Ernesto Pareja (from Colombia) says...
I had to modify my domain... here is my link
Friday Dec 3 2010, 12:08pm Bob says...
Just about to try this myself, great guide, defo gunna follow it fairly close!

Also going to try modifying an inkjet and baking the ink on, plus a few other things.

I agree, your test pattern looks cool would be awesome for the initial trial and error of various projects and printing techniques, please release a download... such a useful file :)

Monday May 3 2010, 10:32pm Christian says...
I am also experimenting with toner transfer.

I really like your test-pattern. Could you give us a link (pdf?) for it?

Tuesday Oct 27 2009, 8:53pm Michael Adams says...
Hi Ernesto, congratulations, the PCBs you've made look amazing! Impressive project you've got going there, definitely making some amazing progress. Thanks for the feedback on pressure, I have had similar problems but wasn't sure how to solve it. Will have to try your methods next time.

Monday Oct 26 2009, 3:32pm Ernesto Pareja (from Colombia) says...
Hello Michael, I finally made it. After 8 tries I have a TQFP 0.5mm pitch with a 10 and 8 mil lines.
To succede I had to lower the iron temperature and not to press the iron to much to the circuit. When I did that the TQFP pads melted with the adyacent so I would have a big SHORT.
I used photo paper glossy 200gr/m2
I will post some pictures in my webpage

Thank you Michael for the inspiration. If I hadn't seen your page I would have thought it was imposible to made it.

Ernesto Pareja J
Sunday Oct 25 2009, 6:04pm Ernesto Pareja (from Colombia) says...
I think the magazine I used is not that good. I've transfered the circuit twice and there are pads in short. I havent etched yet until I get a good transfer.
For how long did you iron the circuit?
Sunday Oct 25 2009, 1:55pm Ernesto Pareja (from Colombia) says...
There are some sites that says that you can use magazine paper instead of expensive glossy photo paper. I already made a circuit (not TQFP, just DIPS and wide lines) using this magazine paper. Today I printed in the magazine paper a TQFP and SSOP footprints with line width of 10 mil (0.025 mm). I hope tonight I will try to transfer it to the PCB. If this not work I will try next week the photo paper.

Thank you Michael!
Saturday Oct 24 2009, 10:19am Michael Adams says...
TQFPs can be done, it's a bit fiddly but nothing impossible. Not sure what you mean by magazine paper though; I just use glossy photo paper from the local stationery shop.
Saturday Oct 24 2009, 5:59am Ernesto Pareja (from Colombia) says...
Hello Michael,

I was looking for all over the web an exambple of toner transfer PCB limits and finally I found your blog. I'm planning to design a PIC32 board and it is a 64 pins 0.5mm pitch TQFP.
Have you tried this method with magazine paper?

Leave a comment?

Your name:
From?: (optional)
Icon: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
Your comment: