Recycling!

I've been using the laser toner method for a while to make my PCBs. It seems to work well for me, I print out the PCBs using a  Samsung ML2010 laser printer, tape them to a cleaned copper board, then run them through a laminator twice. The heat fuses the toner to the board, and as long as your paper isn't too sticky, you can peel it straight off and etch.

I've been using this successfully, even for larger boards like my Arduino mega shield. The key variable seems to be the paper. I have the best results by cutting a square of sticker backing paper, using the stickers to stick it to the centre of a normal sheet of paper, then printing the PCB from Eagle. This works well, but I do need a sheet of stickers (like the A4 laser printing stickers) every time.

Other people have reported success with tracing paper, or magazine paper. I grabbed some tracing paper (two types, Goldline 63gsm and Goldline 112gsm) paper and gave it a try. It printed well, but didn't stick too well - you need to soak the paper to remove it, and most of my toner came off with the paper. Maybe my laminator wasn't hot enough :-(.

So, I'd run out of labels, my tracing paper experiments weren't working well - and then my eye fell on a discarded Farnell packing bill on my table. The Farnell packing receipts are printed on some sort of fan-fold sticker paper so that the address labels can be removed and stuck to the box. The whole bill is basically one big sticker! I cut a square, stuck it to a sheet of paper using the sticker I'd just removed, and ran it through the printer.


Perfect result, first time!  The toner transferred very well to the board:




The finished board (a SMT version of the tiny thermistor circuit) looks great and from the detail (on the lettering) this would work with much finer traces!

I'll start saving up all my old shipping receipts instead of buying printer labels now....



P.S. top tip - after the stickers have been 'laminated' and cooled, if you gently rub the back of the sticker with your thumb, a small 'bubble' forms that gently lifts the sticker backing away from the toner bit by bit. I get almost 100% adhesion with this technique.

Useful PCB notes

http://www.electricstuff.co.uk/pcbs.html

Nice clear semi-pro PCB instructions :-)

Useful suggestions for PCB-making services

Mendel home-made stepper boards

A productive weekend: I used the laserprinter technique to make four more single-sided stepper drivers.
I experimented with plain paper, baking paper, greaseproof paper, oiled paper, but the best transfers were with my cheap label backing paper.
To economise on the amount of label paper, I cut a section roughly a bit larger than the PCB, and stuck it to a clean A4 sheet with some of the discarded stickers. This then goes through the laserprinter.

From StepperPCBs

I then took off this section, bent it over the PCB and taped it down, then ran it through my laminator a couple of times. This transferred the toner to the PCB.

From StepperPCBs

After etching, I had four new stepper boards to build

From StepperPCBs

Schoolboy Error

In my last two boards, I made a schoolboy error:
Both boards (due to different reasons) ended up being reversed left-to-right.
Now, during the transfer from paper to the board, it does mirror/reverse the image. I had 'overcompensated' and flipped the board twice, i.e. the wrong way.

Also, the stepper driver experiment was for the brand new 3.0 version, not the tried and tested 2.3 version (as noticed in the comments).

I've knocked together a version of a single sided board for the stepper driver v2.3 here - you want the v2 for the 2.3 board (eagle and .brd files provided). I dropped the ethernet connections (too many holes) and reverted back to the RepRap 3-pin connectors for the max/min endstops.

Here's a couple of etched boards, using the laserprinter/laminator/dab etching method:

From PCB

From PCB

I had to tidy a couple of edge tracks with a CD pen, but they came out well.

Here's my temperature controller (0-100 degrees C, controlling a relay) for another project:

From PCB

I bought some more copper board today from Maplins, so I should be able to make them a bit larger next time and avoid the issues with the transfer at the edge of the board.
Now to drilling several hundred holes with my new dremmel...

Ah! That's the way to do it!

Last night, I got round to making a couple of PCBs with the LaserPrinter method, using a couple of tips scavenged off the comments and interweb.

From PCB

I printed onto some sticker backing paper from some laserprinter address labels I had around. The first sheet, which was completely sticker-free, was a bit thin and bendy and got jammed up in the rollers and didn't print properly. After retrieving the sheet (and extracting a cat toy from the inside of my LaserPrinter), I removed a few stickers from the centre of a new sheet of stickers, so it was thicker and stiffer.
This printed perfectly.

I then taped on my cleaned copper board (Cif and green scourer again) and put it through a cheap home laminator machine.

This worked really really well. The toner transferred perfectly to the copper, and the sticker paper was left completely clean. It seems to have bonded well to the copper, so I will have a go at etching the boards soon.

From PCB

I re-printed my temperature controller PCB board. Since I only had a PDF of the circuit diagram, I had to mirror it before printing. Last time, I used a command-line utility and a converter - but this converted the tracks into a low-res jpg, which worked but was certainly not the best quality.
This time, I printed out the PDF version and measured the printed PCB (49mm). I then zoomed in, so the tracks were filling the whole screen (in the PDF reader) and took a screenshot. This screenshot can be cropped to the edge marks, and flipped in GIMP, and GIMP offers specific print options to print out at exact sizes - i.e. the size measured earlier. This worked well (apart from a minature mouse pointer appearing on my PCB tracks!)

Single Sided Makerbot Stepper Driver board

From PCB

I've been trying to get hold of the Stepper driver board for a little while, but while waiting I thought I'd try and make a single-sided version of the PCB that was easier to etch at home.
First task was getting to grips with Eagle, and downloading the .brd files from the RepRap repository. The biggest problem with the mix of through hole and surface mount components is that the pads end up on both sides of the board - the through hole pads are on the bottom, and surface mount on the top.
I loaded up Eagle and mirrored the through hole components onto the other side of the board. The plugs are now pointing downwards (not ideal) but at least the pads are now on the top side. Rotating the connectors by 180 degrees helped match the tracks to the existing routes.
This left lots of messy tracks on the board, but a bit of work tidied them up. I then went to work moving via's (that would now have to be wire links) and moving the via points so they are not underneath the surface mount components, as I'd have to through-hole solder them. I'm no circuit board designer, so I went with moving the components as little as possible, and re-routed the tracks to avoid or shorten the vias where I could. Straightening the vias helped avoid crossing wires, and some of the connectors could be connected directly.

I printed off the PCB and transferred it to the copper. If it etches well, and I can drill some holes without ripping all of the tiny tracks off the board, it might be worth getting some components to build up a version.

[Edit - here are the eagle board files for anyone who's interested. Probably there will be later versions that might actually work.]

Home-made (bodged) PCBs!

For a little while now, I've been interested in trying to make my own PCBs using the laserprinter method discussed on MAKE. I finally got around to trying the method today, and I'm really impressed with the results! For my first attempt, it worked well.

I needed a temperature controlled waterbath for a separate project, and I found a suitable circuit on the internet, courtesy of a Make article.
Instructions and comments below:

It had a PCB diagram, so I didn't need to mess about with designing my own.
Print out the PCB diagram, at the correct size, mirrored, then use it to cut a copper PCB to the right size. For my first attempt, I made a couple.Make it as dark (as much toner) as you can.

From PCB

Clean the surface of the copper as well as you can. Any grease stops the toner sticking. I used a green scourer and some 'Cif'.

From PCB

Take your dark laserprinted PCBs, and tape the copper side of the PCBs to the stencil.

From PCB

I then ironed the back of paper (setting on 3 dots), letting the heat soak into the copper. The heat causes the toner to melt and to stick to the copper. Spraying water on the back of the paper, you can see the toner stuck to the copper:

From PCB

Using water and rubbing, most of the paper can be removed, leaving the toner on the PCB. It seemed to be pretty well stuck on, and only a couple of little gaps.

From PCB

When you've got the paper off you can see the layout on the copper board. Any gaps or tidying up can be done with a sharpie marker - apparently they are also etch-resistant, like the toner.

From PCB

Now, it's time for the etching. I got a standard bottle of etching solution from Maplins. Note that this can be messy and this stuff is nasty chemicals - treat with care. It will stain pretty much anything it comes into contact with (including stainless steel sinks!). Wear rubber gloves and take care.
I poured some into an old plastic container, and used a soaked tissue to dab and rub it onto the board. The toner works pretty well as a stencil, resisting the etching - and dabbing it by hand allows you to pay extra attention to the edges or places where it needs more.
No pictures, I'm afraid, as my hands were all dirty.
After a few minutes, it's fairly obvious when the copper is etched away. I was able to rub over a few areas that weren't quite done yet to finish it off, then I dunked them in a big bucket of water to clean them up.
The black toner can then be scrubbed off using a green scourer, leaving a completed board:

From PCB

This left a pretty good result. It still needs drilling (a chance to use my new Dremmel! Yay!) and a little repair where the toner didn't stick, but I'm pleased with the first attempt.

This technique looks suitable for the few 'one-off' boards for specific projects now and again.

The final result:

From PCB