Making PCBs with the toner transfer method has been around since you could buy your traces at Radio Shack. There are a million techniques for removing copper from sheets of fiberglass, from milling to using resist pens, to the ubiquitous laser printer toner transfer. Here’s a technique we haven’t seen before. [Darko Volk] is calling this ‘chemotransfer’. It’s mostly a laser printer toner transfer process, but the toner is transferred from paper to copper with the help of a special mix of solvents.
This chemotransfer process is almost identical to the usual process of making a toner transfer PCB. First, the design is printed in reverse on dextrin-coated paper, the paper is placed down on polished copper, the entire assembly is sent through a laminator, and finally the board is etched with the chemical of your choice. The key difference here is a solvent applied to the copper just before the design is laid down. [Darko Volk] made a mixture of 25% “cleaning petrol” (benzene, naphtha, or gasoline, or some sort of light hydrocarbon, apparently), 5% linseed oil, and 70% isopropanol. This apparently aids in releasing the toner from the paper and sticking it down to the copper.
From there, the process is effectively a standard toner transfer process. [Darko Volk] is using a solution of sodium persulphate for the etch, and rigged a camera up to a CNC machine for the drilling.
This process can be expanded to two-layer boards very easily using a light table to align the layers of paper before placing them down on the copper. You can check out a video of the fabrication of a single side and double sided board below.
Thanks [Andrej] for the tip.
54 thoughts on “Chemotransfer For DIY PCBs”
So it is basically just like the “Cold Transfer” featured here before but with a slightly more complex setup of chemicals/solvents? https://hackaday.com/2016/01/12/even-easier-toner-transfer-pcbs/
Looks like it and thanks for that link which I apparently missed it when it was originally posted. I have no issues with my toner transfer process, but am limited to thinner PCB material because of the need to pass it through the laminator. The cold transfer method will allow thicker PCB material to be used. Hurrah!
BTW, in the Hackaday article it simply says “alcohol” which led me to wonder what TYPE of alcohol to use. In the linked Instructables it says ethanol (grain alcohol – booze), but the guy apparently bought what I suspect is pure stuff from a drug store instead of using the vastly easier to obtain denatured alcohol which is typically 90- 95% ethanol with stuff in it to make it undrinkable (because the government wants to tax the drinkable version).
ANYWAY, it appears that the essential part of getting that process to work best is to read ALL of the comments below the associated Instructable guide.
I guess the person in the video doesn’t really need the pure alcohol, after seeing the excess alcohol poured back into the bottle, mixed with some of the other ingredient…
I only skipped through the above video once I went to the Instructables link for the simpler method with fewer and better defined solvent components and with especially useful user comments describing actual experiences using it. In the method described in the column above, “cleaning petrol’ (benzene, naphtha, or gasoline, or some sort of light hydrocarbon, apparently)” is an inadequately defined ingredient IMO.
NH4OH works well for prepping the copper too. Just rub it with ammonia solution until the cotton gets blue before sending to the laminator.
More information about this method can be found here: https://www.s5tech.net/viewforum.php?f=95
The acetone and isopropyl alcohol works just as good and doesn’t need heating from a laminator but the pressure of the rollers would help.
I use Toner Transfer from a color laser printer to transfer decals to instrument faces. The best thing about using acetone and isopropyl alcohol is that you can transfer to surfaces that wouldn’t handle the heat of a laminator.
Coldtransfering color laser for front panels sounds intriguing. Do you have any pictures of the end results?
I’d love to see that too
Yes and no lol
Pictures yes but of hot transfer
Cold transfer es but pictures lol
I tried all this, but it does not work so well.
Did you paint the surface white first.
Color laser uses CYMK (cyan yellow magenta black) which are the subtractive primary colors that need to placed on a white background unlike the additive primary colors red green blue that are placed on a black background.
Given the toner is disolved by the chemicals, how much does the image bleed from being squished by high pressure? When trying the iron toner transfer method, if I press too hard the image becomes *very* blurry and doesn’t etch well.
My laminator is very tight. Sometimes I have a hard time getting boards to fit through without tearing up the transfer paper. Sometimes it takes a couple of tries. When I do manage to get it through though I do not notice any blurriness from squeezing. I only see that if it is not tight enough and the paper is allowed to slide a little.
I use this cleaning gas: http://www.chemcolor.si/eng/benzine-for-cleaning.html
It looks like you’re using benzine which apparently is a translation of the word gasoline? The article says benzene…not sure you would want to be using that
Yes, gasoline, petrol, but without all the octane boosting additives, so that won’t leave a residue.
As a lab solvent, petroleum “ether” https://en.wikipedia.org/wiki/Petroleum_ether the lightest liquid hydrocarbons distilate, high aliphatic and low aromatic. Also white gasoline or just https://en.wikipedia.org/wiki/Coleman_fuel for americans.
We also have a similar product “Cleaned Gasoline”, it’s just a mixture of hydrocarbons sold for stain removal.
It could be the same product they sell (under commercial names and at inflated prices of course) to remove stickers safely, the correct name should be “adjusted gasoline” though I’m not sure if it’s the same product.
Gasoline without the additives needed for combustion engines…
Yeah I’m wondering if white gas or coleman fuel isn’t the closest thing here.
Motor fuel gasolines, among other problems have metal deactivators in, so it is likely to passivate the surface of the PCB and not let some etchtants work…. though I’m fairly sure ferric chloride would burn through it.
Wrong ! Even the ferric chloride does not damage this protection. Tested.
I do not recommend this chemical because it is aggressive and leaves brown stains that can not be removed.
I use 8 parts Isopropyl alcohol to with 3 parts actone – much more human friendly than benzine if benzine is a hydrocarbon?
Acetone is a ketone which isn’t the best for humans either but it’s probably better than a hydrocarbon and when mixed with a higher volume of Isopropyl alcohol it’s impact is reduced further.
The closest thing to benzine that I have used is “throttle body cleaner” for cleaning car intake throttle bodies and I avoid that as much as possible but if I can’t avoid using it then I use a mask with organic filters and of course protective clothing and eye protection. Though I do use a MAP replacement flame which may possibly have some benzine in it but I assume it to be safe as a product retails for that specific purpose.
Also I noticed in the video that you have to scrub the paper away from the toner. The article says you are using dextrin coated paper. I use pulsar (brand) dextrin sheets and drop them in water and they just peal off the PCB completely by themselves in 5 to 10 minutes. I just gently rub water over the PCB to remove any still undissolved dextrin.
“I use 8 parts Isopropyl alcohol to 3 parts acetone – much more human friendly than gasoline if petrol is a hydrocarbon?”
Also tested, but the results are not so good.
Yes, OK, but what form of toner transfer media are you using?
The process in the video was not made in one day. It is the result of many tests.
Check out the tables here: https://www.s5tech.net/viewtopic.php?f=95&t=4545
And of course here: https://www.s5tech.net/viewtopic.php?f=95&t=4464
Thank for that. I will go look.
There also seems to be some confusion here between benzine and benzene unless there actually the same and I am the one that is confused.
Yes, benzine is a known human carcinogen. It’s the primary contaminant from the “Love Canal” incident! If they don’t sell it for cleaning purposes in your part of the world… there is probably a good reason for that.
I just put Elmer’s glue stick on the paper before printing. After ironing the paper to the board, soak it in water to dissolve the glue and the paper just floats off leaving the traces on the board.
Interesting method. It doesn’t ruin the printer?
Here’s an instructable on the Elmer’s White Glue method:
Great share and beautiful walkthrough of the process.
Thank you for sharing!
I loved seeing that you used a Wolven wheel to clean the board (I would love to have one!????). But a serious question is “do you dress the wheel with anything or just use it dry?
VM&P naphtha, petroleum ether, ligroin, white gas, Coleman fuel, or Shellite as we would call it in Australia. A vaguely defined non polar, water insoluble mixture of mainly C5-C8 aliphatics with no residue on evaporation and no additives.
Ah, now I know what Shellite is!
Isn’t Coleman fuel just Kerosene?
“Coleman fuel is a mixture of cyclohexane, nonane, octane, heptane, and pentane.”
I guess I should have looked it up. =/
I believe you’re making the white gas, white spirit, false cognate error.
Thanks for finding this HAD. It’s a good one, but not a bell ringer.
The music is annoying and the video is best watched with audio muted – there is no valuable audio.
The neat solder tinning is nice to watch, and the camera system that manually spots all the holes, generates G-code and drills them is impressively nice. The use of a proper guillotine for chopping the board neatly, without hacksawing, is also nice.
By the way, no mention of Kerosene (UK Paraffin) ??? that I thought was the default for toner transfer assist?
Technical Data Sheet for cleaning gas:
My meaning was that hasn’t kerosene been used in the past, rather than asking if kerosene was used here.
Interesting. At first I thought why add even more messy chemicals to this already caustic process. He even uses a laminator and a laminator would transfer the toner all by itself. It seems very unecessary. But.. he did achieve a very clean transfer. I’m not sure a laminator by itself could do so good a job so hey… good work!
But… something important seems to be missing. Don’t try this one at home kiddies without this one more ingredient… http://alturl.com/2s6y7
Actually… considering the solvents involved this might not be a bad idea as well… http://alturl.com/i2ad2 Although.. I would probably look for a safer substitute first rather than go the full protection route.
This article is about the use of benzine and not benzene. They are completely different.
without the use of gloves you will not have fungi :)
as a chemist I might give you guys a little insight into the health hazards of the solvents which are used in this process.
All are flammable, keep them away from hot surfaces e.g. reflow / soldering stations. The person in the video uses quite a lot of solvent mixture, work in well ventilated areas. Do not inhale the fumes :)
Aceton: Degreases the skin, is often used in nail-polish remover. Breaks through typicall Nitrile / Latex gloves. Overall: not the most unhealthy / dangerous chemical. Girls use it ‘all the time’ :)
Isopropanol: flammable, properly the most non-threatening chemical here
Cleaning petrol: The stuff you can buy OTC is mainly a mixture from lower, branched alkanes. The branches ones are not as unhealthy as the linear ones, especially n-Hexane. These compounds should not be mistaken with the petrol / gas you guys use in your car. Mixtures of these alkanes are uses as lighter fluid for Zippo lighters and as acetone the mixture will degrease your skin upon contact. Overall: Can easily be handled by anyone with the usual precautions.
Regarding the “degreasing” of your skin: Simply to not pour the solvent mixture on your skin and try to avoid contact. Even if you come in contact with it hardly anything will happen. The degreased skin looks “white” and dry, use a lotion or a similar product for regeneration.
A potential hazard if you’re particularly daft, dip a whole arm in it and attempt to blow dry is that you could induce frostbite.
Not really, sure the arm / skin get cold but you would not get any frostbite.
Please be kind and respectful to help make the comments section excellent. (Comment Policy)