Sharing my personal experience with homemade PCBs using toner transfer. - Page 1
Forum section: electronics / general

author: Refrigerator
author_rank: Super Contributor
timestamp: August 09, 2014, 11:46:48 am
content: Hello.I've been making my own PCBs for about two years now and i'd like to share a my experience with everyone.first off is the the toner transfer part of the board, this i one of the most critical parts.When doing toner transfer it's always very important to get the right paper, some people use sticker sheets with the sticker part removed, but i found that regular cheap photo-paper works really well.Then comes the ironing part. When ironing it's really important to know the right way to do it, not every printer is the same.For higher resolution printers you only need to press down and gently rub the iron around the board for a minute, but with older printers ( like mine is ) you need to press down much harder and really rub that iron on the board for a minute or two.For example here you can see what happens when you don't apply anough pressure on the older kind of printers.On the picture it looks much better that it really is.And then then comes the part when you remove the paper. I remember watching tutorials on the internet and all of them told to put the board into water right after the ironing, but i found a better way to do it. The problem with soaking it in water is that softens the paper and it starts to tear and you have to rub and scrape it out which can damage the toner and it takes too much time. Here's an example of the paper being stuck .( Now comes the part that requires photo-paper to be done) What i do is to just leave the board to cool off and then lift off the paper without any water or anything. It comes off relatively easy and if done correctly will give 100% perfect transfer.Here's an example of what the paper looks like after being taken off.Then comes drilling the holes. It's one of hose things you don't really pay much attention to but it does matter. In the following picture you can see a bakelite PCB with two holes drilled with very little pressure and next to it is a standard "just do it" hole.You can see that there's quite some material chipped out around the hole, I had this chipped material get stuck inside the hole making it harder to insert a component.Here's a FR2 board.The holes are much nicer but you can see that one of the holes is just a little more "fuzzy" that the other.And here's the FR4/fiberglass PCB.The holes are nice and clean, since it's fiberglass there will always be tiny little fibers around the holes.When you have your board etched and your holes drilled then comes the soldering part. Only wipe the toner off right before soldering your components on or tinning the board, because if you leave the copper exposed it will oxidise and it will be quite difficult to get a good solder joint.Anyways, i hope this helped at least someone. Good luck and have a nice day

author: miguelvp
author_rank: Super Contributor
timestamp: August 10, 2014, 02:52:38 am
content: Haven't tried it yet, but take a look at this:http://hackaday.io/project/2306-Toner-Transfer-with-Kapton

author: tautech
author_rank: Super Contributor
timestamp: August 10, 2014, 03:25:48 am
content: QuoteBakelite type board needs backing when drilled for a clean result. A thin piece of timber or plywood works well.Remove toner and spray with PCB lacquer to prevent oxidization. I use a solder through type.

author: george graves
author_rank: Super Contributor
timestamp: August 10, 2014, 04:23:14 am
content: Quote from: miguelvp on August 10, 2014, 02:52:38 amNot impressed at all.

author: rs20
author_rank: Super Contributor
timestamp: August 10, 2014, 04:27:42 am
content: Quote from: george graves on August 10, 2014, 04:23:14 amCan you be more specific?

author: miguelvp
author_rank: Super Contributor
timestamp: August 10, 2014, 05:03:22 am
content: I agree on the not impressed with the quality of what is on those pictures.Wished they had better picutres of the kapton printed, maybe it was the pressing process that resulted on the bad transfer.Also the line in the middle was for using more than one width of the kapton tape, so either wider tape or make sure there is no gap.

author: c4757p
author_rank: Super Contributor
timestamp: August 10, 2014, 05:35:04 am
content: Quote from: rs20 on August 10, 2014, 04:27:42 am"Looks like shit". Broken traces and splotchy pour.

author: miguelvp
author_rank: Super Contributor
timestamp: August 10, 2014, 06:25:46 am
content: True, but judging by the first picture (that looks unretouched) there are a lot of sections that are ok, so bad printer or bad press transfer.But might be worth it to use kapton if you printer has good coverage, the one in the project seems to not be a good printer or the toner was low.

author: Refrigerator
author_rank: Super Contributor
timestamp: August 10, 2014, 07:06:16 am
content: Quote from: c4757p on August 10, 2014, 05:35:04 amI agree, you would get the same result using just standard paper. This is how my boards look.Paper removed.Etching.Finished product.Yeah, how do you like them apples ?

author: rs20
author_rank: Super Contributor
timestamp: August 10, 2014, 08:23:44 am
content: Quote from: c4757p on August 10, 2014, 05:35:04 amI haven't used the toner transfer method for years, but I remember how annoying and fiddly it can be. Just throwing it out there; maybe some people's metric for "good" here is "functionaland easy to do", rather than purely focussing on a stunning end result? Everyone's got different paper supplies, different printers, different irons, different techniques; it's no wonder different people have such varying experiences.Refrigerator: I, for one, am stunned by the idea that you did that with plain paper. What kind of toner falls off matte paper like that? Or did you remove the paper by soaking it or something?

author: IanB
author_rank: Super Contributor
timestamp: August 10, 2014, 08:36:58 am
content: Quote from: rs20 on August 10, 2014, 08:23:44 amAs per the first post the good results are not obtained with plain paper, they are obtained with coated photo paper.

author: Refrigerator
author_rank: Super Contributor
timestamp: August 10, 2014, 12:33:21 pm
content: Quote from: rs20 on August 10, 2014, 08:23:44 amYou got me wrong, i use glossy photo-paper, I meant to say that the kapton method looks like it was done with usual paper.The secret is in the gloss ( laquer ) on the photo paper, the glossy stuff peals off with the toner.By the way i use the cheapest photo paper i could find.

author: george graves
author_rank: Super Contributor
timestamp: August 11, 2014, 01:48:17 am
content: Quote from: rs20 on August 10, 2014, 08:23:44 amIt can be. Once you have a method perfected(that work for you), you can whip out a very nice board, consistently.Every one of the online tutorials I see have one thing or the other that wouldn't work for me.

author: Mosaic
author_rank: Regular Contributor
timestamp: November 23, 2014, 03:19:54 pm
content: Hi y'all...Have a look at this!https://hackaday.io/project/3363-apache-al13p-laminator-one-pass-pcb-toner-xfer

author: steve_w
author_rank: Regular Contributor
timestamp: December 09, 2014, 01:03:45 am
content: Here is an Australian mod to achieve the same end result:http://ultrakeet.com.au/write-ups/superFuserV2I have corresponded with the author he is a really helpful guy. I made the mods suggested and they work.RegardsSteve_w

author: george graves
author_rank: Super Contributor
timestamp: December 09, 2014, 04:49:39 am
content: If you can get consistant results with that, awesome.But with out modding a laminator, they are worthless IMHO. I have the suggested laminator from "PCB fab-in-a-box" and that guy is on crack. It doesn't work. I think there was a HAD (hack-a-day) article where someone addied PID (or PI) control to get good results. So you might look into that.But again, if you find something what works - good on you!

author: poorchava
author_rank: Super Contributor
timestamp: December 09, 2014, 06:47:07 am
content: Back when I was using toner transfer, I found out that the key to successful transfer is paper removal process and layout preparation. By my experience, hatched polygons/fills work much better because toner concentrates on smaller area (while total amount of toner per area unit is still the same). Another thing is using glossy (eg photographic) paper which has thin layer of chalk pressed on the surface and using vinegar or lemon juice to remove the paper. The chalk layer peels off from the paper and then you only need to gently brush off the chalk residue. There is next to no force applied to the toner, so it's extremly unlikely to peel off.btw, dry film still FTW, and protoboard/kynar wire mockups even more FTW

author: Refrigerator
author_rank: Super Contributor
timestamp: December 09, 2014, 01:53:10 pm
content: Quote from: poorchava on December 09, 2014, 06:47:07 amInteresting.To me ironing seems like the most important thing. I've since found out that ironing for too long makes the toner peel off.

author: ampdoctor
author_rank: Frequent Contributor
timestamp: December 10, 2014, 04:57:10 am
content: I have never EVER had good results with any photo paper. The best results I have achieved were with magazine paper. Actually, it's paper in those advertising catalogs you're plagued with in the mail on a daily basis, wireless world, sharper image, woman within, etc. So you have a virtual endless supply of free paper that you would otherwise throw in the bin. The toner sticks to the sheets but just barely. Look at it wrong and it'll smudge, which is actually a good thing. It takes less heat, less pressure, and less ironing time to get a good transfer. Only down side is that if you didn't set up the printer correctly to accept light stock you can get paper jams very easily. I have never noticed the peeling issue but what I found is that if you over iron it you'll get fuzzy traces. My guess is that you actually liquify the toner.Here's how I do it and I rarely get a bad transfer...First I print the transfer out on the aforementioned paper from my eda gerber files using gerbv with the colors set to #000000 and opacity at 255. Anything else you'll get a shade of grey.Next and this I think is what makes or breaks the transfer more than anything else. Prepare the copper after washing and scrubbing with 600 or higher grit emery or sand paper.DO NOT USE STEEL WOOL!!!!!This gets absolutely everything off the copper clad. Now clean off any sanding dust or residue with IPA and standard kitchen paper towels.Now for the secret step. Pre-etch the board! Drop it in your etchant momentarily till it just barely starts to discolor and turn an off pink color. This takes about 10-15 seconds give or take a little depending on the strength of your solution. Once you've done this step the toner hangs onto the copper like grim death!At this point it's just business as usual with the iron and the transfer. With this paper as I said earlier, you'll use less heat, time, and pressure. Typically I'll set my iron to the highest setting just before you get to the steam settings. And I usually iron for about 2 minutes with slightly more pressure than you'd use if you were to iron a pair of pants.Like anything else, experiment on a piece of scrap and take good detailed notes. Once you find the parameters that work best with your setup follow it like religion. Using this procedure I can roll 10/10 boards all day long with no issues. If I get a bad board, which is rare, it can usually be traced to impatience or poor process control on my part in some way or another.

author: ozwolf
author_rank: Regular Contributor
timestamp: December 10, 2014, 05:22:23 am
content: I've tried the toner transfer with good results. Photo paper & iron, no problemsHowever, I really like the idea of "pre-etch". I'll try it on the next board.Ozwolf

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 10, 2014, 09:45:19 am
content: FWIW, if you're troubled by paper residue (typical for ordinary print paper, unusual for coated photo paper), it can be decomposed or dissolved with concentrated sulfuric acid. However, this will also tend to etch the toner itself, so use cautiously. Probably, a moderate concentration (50-80%, but not goopy 90%+) at room temperature is best. Chemistry is, cellulose is hydrolyzed and becomes weak or dissolves entirely. The effect on toner depends on composition, which I don't know about.Concentrated sulfuric acid has little effect on elemental copper, but will dissolve it if an oxidizer is present (e.g., H2O2?).Tim

author: Zero999
author_rank: Super Contributor
timestamp: December 10, 2014, 03:59:35 pm
content: Has anyone tried clay coated magazine paper? I've find it works well with the old Cannon LBP-660. I've not tried any newer printers though.It's also possible to do a silk screen but it needs to be covered conformal coating, after the paper has been removed, otherwise the toner will rub off very easily.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: December 10, 2014, 09:11:24 pm
content: After many years I reverted back to doing the toner transfer method on an old 1970's KLM radio used for ham satellite communications. This was one of the first rigs introduced to hams for this purpose. The power supply board had taken a lightning strike and blew a hole in it the size of your thumb. I few years later I found another rig for a donor but want to get the donor radio working.So I set out to reproduce the power supply board and this was the resultsThe top board is the original. I wanted to get the new one as close to stock as possible.Did not turn out too bad.

author: tautech
author_rank: Super Contributor
timestamp: December 11, 2014, 06:40:19 pm
content: Good info.Quote from: evb149 on December 11, 2014, 04:11:10 amThis was my secret ingredent for years.My wife worked in an office where they put heaps of backing sheets in the bin....home some came.Exactly as you have described, print on plain paper first, stick transfer medium/paper over that image and print again.Fine for 20 mil/thou traces with my old HP 5MP at 600 dpi, but when I started Gnd pours and 10 thou tracks there was too much porosity in the toner for a good job.My transfer process was and still is a small desktop laminator, with the transfer paper and PCB in the thin cardboard carrier folder that came with the laminator.Set it hot and 2 passes.IMO an exactly repeatable process ensures consistant results and is the reason I have stuck with a laminator.But this process smudged the toner at 1200 dpi using the adhesive label backing sheet and an Oki C5200 laser.So to find another paper, glossy....same problem, ended up using a thin semi-gloss paper that I had a heap of.With the Oki it was back to the old way, of soaking and carefully rubbing the paper off.But the transfer was black, really black and no pin holes.Etched mint.It is NOT an exact science, you must find what works for you.Probably a test etch with 10 thou tracks and a Gnd pour is all you need to check your processes.

author: con-f-use
author_rank: Unknown
timestamp: December 11, 2014, 09:52:18 pm
content: Quote from: ampdoctor on December 10, 2014, 04:57:10 amI can second that. But for me it only worked with ferric chloride and what's the greenish blue stuff (Amonium something?). HCl +Peroxide etchant gives me a very bad transfer if I pre-etch with that.

author: Refrigerator
author_rank: Super Contributor
timestamp: December 11, 2014, 11:34:39 pm
content: Quote from: con-f-use on December 11, 2014, 09:52:18 pmI used to use HCl + peroxide before i knew that it decays over time, now i use concentrated CuCl2+ HCl , which not only does not decay over time but gets stronger as it absorbs oxygen from the air, which works out very well for the occasional etching.

author: con-f-use
author_rank: Unknown
timestamp: December 12, 2014, 10:31:53 am
content: Well the one turns into the other. If you use HCl + H2O2 and don't throw the solution away, when it doesn't etch, you get a cupric chloride etchent. That is, provided you add Oxygen (either by adding H2O2 or ventilation), once the original HCl+H2O2 gets slow. So for me those two are interchangeable. I use the same solution since my last move a year ago - just with additional peroxide. Still doesn't work as pre-etchant. But might be the copper clad board is weird. I also switched brand.