Without wasting much time, let’s jump right into it and figure out how to create insanely accurate PCB’s with toner transfer method. There are a ton of videos out there explaining the process but watching them and struggling with my PCB’s I realised they all talk about the process, but none of them really detailing how the process actually works and where things could go wrong, hence this post detailing the process and suggestions on things that could drastically improve the outcome based on my own learning / realisations
I assume, the reader would have the PCB Scheme ready for a print and would follow commonsense precautions for his own safety.
- Copper Cald Board
- Toner Transfer Medium / Paper
- Access to Laser Printer
- Cleaning Agent
- Ironbox or Laminator
- Etching Agent
- Other safety equipment ( Rubber Gloves, Protective glasses Ferric Chloride is a moderately strong and corrosive Lewis acid and will work with your body in ways, I am sure you will not enjoy.)
Act – 1
Get your stuff together and clean up.
Cut the required size of the Copper Clad and file away any rough uneven edges / corners that don’t lineup with the surface of the copper. Clean copper clad gives best results and in most cases your kitchen dish washing gel or bar and Rough Kitchen scrub are good enough to shine it up sufficiently, also in my experience if you have sweaty / oily hands that leave prints on the copper, it might negatively affect toner transfer, so wash up. 🙂 . Do not touch the copper surface after the cleaning process and dry it up using a clean rag / cloth (insider tip : Also it helps the toner reflow and stick well to the copper clad if you mildly score the copper surface, I personally not for it and avoid it as much as possible but it helps. Use metal wool / Metal kitchen scrub).
Act – 2
Print the mirrored artwork / PCB Scheme.
I would like to say, the choices you make here will have significant bearing on the results. I have tried different paper materials and can vouch for the effectiveness of Heat Toner Transfer Paper . I recently bought some and these are the best results, I have ever gotten. There are other sellers on ebay and online but I have not tried them yet, will look out for cheaper solutions and will update this page after I have tested them. The other cheap and alternative is to use the backing paper of stickers, I often get FedEx packages with A5 sized packing stickers intact and they work pretty well. I have not been able to source them cheaply enough.
The above mentioned paper is laminated (smooth) only on one surface and that is the surface you would want to print on. so when you put it under some water the paper just peels off without effort leaving the toner on the copper clad. The other medium people recommend is the Photographic paper but the problem with that is that it is laminated on both the sides and is a little too thick. This makes the heating process a little messy as the top lamination melts and sticks to your ironbox and also during the peeling off of the paper, it is quite hard to not damage the toner and they are expensive anyways.
The Magic happens here
Now cut out the art work to the required size and heat up your laminator to 180 – 200 Celsius or if you are using an Ironbox, put it on Cotton. Now aligh the copper clad and the toner transfer paper and on top of it put a cotton cloth, just to make sure you dont move / misalign the setup before it sticks to the board. The toner transfer paper would ideally stick to the copper clad and now it is just a matter of uniformingly heating the PCB and holding it there for 8 -10 mins for the IronBox and if you are using a Laminator a couple of passes should suffice. I usually let the board cool off, after this and soak it in some water for a minute and gently pull the edges off to reveal your close to perfect Toner Transferred Copper Clad.
There is not much in here, just follow standard etching process, get some Ferric Chloride and mix it with a reasonable quantity of water and etch the board. Here too, using too strong of an etching agent can corrode off the undersides of the toner and damage the tracks, specifically for thin lines so it is rather better using a lower concentration etching solution and let it etch for longer.
Here is my finished PCB 🙂 . Will also have to figure out solder mask, also it has over etched at places as it was done overnight, still pretty neat traces.
Compared to my earlier attempts
That’s how far I have gotten so for, please do let me know if you this blog has helped you or if you use any other process and if that is any better way of doing this in the comments below.
Disclaimer : I am not associated with any of the links mentioned in the blog or benefit from these links, I just am documenting my experience and wanted to share most the relevant details.
I am the founder of Apeiron Mobility, an eMobility startup working towards creating and deploying insanely sensible eBikes for India and other southeast Asian markets. I also used to be a tinkerer and as much as I love tinkering, I don’t get to do it as much and that’s the Irony of startups, you startup because you love doing something, but then if you are among the founders there are so many things that are not really exciting but do them, you must. That shall be the topic of another blog post.