Toner Transfer Method – Reference Document

Hey, thank you for your afford. It is nice to see another PCB aficionado here. Personally I made myself such a list almost 2 years ago, and I also write a task list/tutorial, but only in czech for the czech diy electronics comunity. 

Yet after two years I am still improving the process, since there is always room for improvement, right? Currently I am searching for the best paper. As to your printer question: The best for me so far works a Lexmark T650. It is an older model, but still a high volume office printer capable of dispensing a lot of toner and (!) with a very high temperature fuser. Unfortunately none of the recommended paper mentioned in Mr. C’s videos is optainable here in czech republic, so I have to do my own research. 

As to other methods, I think I tried them all. 😀 I milled my PCBs on a CNC, drawed them with permanent marker (on CNC as well), used the photo PCB method (with UV, developer and presensitized PCBs), I even tried making them with a laser engraver (to evaporate a black paint layer from the surface of the copper)… But the toner transfer still works best for me (I also invested the most time into exploring it). 

If I can give you any more tips into your list – I can tell you, that the Xerox Phaser 3020 does not work for toner transfer very well. It is too shy on toner and also too cold. 

I hope the list will grow and that you will be able to finally find the printer of your (PCB making) dreams. 🙂

My experience with printers: my own printer that I’ve used with very pleasing results for years now  is a small form factor HP LaserJet P1102W.  I’ve purchased it from a local second hand! store and only ever used the original HP toner cartridge with it. It worked beautify from day 1 with a nice deep level of black  and it still works the same to this day !. No issues whatsoever. Having said that, before having my HP I’ve tried a number of Brother printers but in my case, they all failed miserably. I was simply unable to get the black to be truly black (with those) and the toner wouldn’t stick properly to the paper even thought I was using the exact same paper that MCL has recommended to us (on Patreon channel) in the past. Looking at the printout with a basic magnifier I could always see like a mesh of holes all over the print. The toner used was always the original Brother Toner but unfortunately no amount of printer settings could fix that. The etched PCB always had holes all over. So I’ve started to search online on various forum sites and found out that, lots of other people had reported the same issue and stopped using them for good. So I’ve decided to switch brands as well and to my big surprise…..the minute I’ve switched to my (current) HP and using the same paper ! the difference was like….wow!…day and night. Nice deep blacks with great consistency every time.  Now, please note that this was quite a number of years ago and the printing technology such as toner composition, drum temperature etc might have changed (at Brother Manufacturer) because ironically and contrary to my reports above, I see that MCL and other people actually use some (most likely) current models or perhaps more advanced models of Brother printers and report good results using it, so….what I say might not entirely hold true today if you buy a newer “more current”  Brother printer model. I really don’t exactly know what the exact answer would be. 🤔 

Hello Everyone,

I spent 40 years as an EE designing electronics for several companies: a major instrument cluster company, SCADA products for the paper industry and various one off projects as a consultant in the automotive and other industrial concerns. I, like many of you, have tried many methods for making PCB’s for the one off things that you need for fixtures or prototypes.

I do have a surplus LPKF CNC PCB machine that I use on occasion but it is just too fiddly at times, not to mention the dust!

I do also have a CNC3040 chinese machine that I set up to do single sided boards using LinuxCNC in conjunction with SprintLayout6.0 and the free third party tool called SL2M3 which works well but I’m always looking for an easier way.

I still use SprintLayout6.0 as my PCB tool as it is easy to learn and use, has lot’s of nice features and has been virtually bug free in the 15 years or so that I have used the Abacom product. I have designed over 1000 boards with it. They also have a great tool called FrontDesigner3.0 for doing front panels too.

For making PCB’s I am currently using the Toner transfer method.

I bought a surplus Kyocera P2040dw 1200dpi capable printer for this purpose. It will really lay down the toner if you set the darkness from the front panel to “5”. For some reason this setting does not appear on the web interface for the printer and I don’t know why. I need to ask them about that.

I am using the Yellow special coated transfer paper you can get on eBay or Amazon (Amazon has stock in the USA so it shows up in a few days) I think 100 sheets were under $20.00. This paper works like a champ and it does not require any water to remove the backing, it just peels off easily. Much better than the dozens of standard papers I have tried. The resolution of this paper is amazing.

I have a TruLam 320P laminator and I modified it using a design I found on Hackaday that cycles the rollers in and out moving the board through the rollers in 1/8″ increments to ensure an even heating. I run it between 350F and 370F. 10 mil traces are no problem.  I use TRF (Toner Reactive Foil) to seal the toner before etching. You can find the Gold Leaf brand of TRF with a Google search buying a roll of 10 meters for about $5.00. This is the same film brand that PCB-Fab-in-A-Box used.

I use the same process to put silkscreen on the board after drilling to properly locate the silkscreen. I could follow that with any color TRF if I wanted to.

I am using a manual drilling process where I drill all of the holes with #70 (0.028″) drill first and follow that with a larger size where needed. My current drilling rig is a Proxxon TBM115 drill press running at 4700 RPM. I formerly used a Dremel tool, but it is very noisy and has a limited throat depth and the runnout after many years of use is not as good as the Proxxon. The Proxxon runs a little under $220.00USD. I have not tried any double sided boards this way yet, but plan too soon. Additionally, I want to press the LPKF 91S into doing the drilling as that is by far the most time consuming part of the operation.

My current etching method is 50/50 mix of Citric Acid and Hydrogen Peroxide and a dash of NaCL (table salt). Warming the mixture aids etching add salt as needed to reactivate. Sometimes it needs a dash more of the Citric acid or Hydogen Peroxide. Maybe someone who is better at chemistry than I am tell me the perfect ratios of the Citric acid powder and H2O2 and salt. The spent solution can be diluted and flushed down the drain. I want also to try Ferric Chloride using the dauber sponge method as it would be quicker, but disposal is a bigger issue but according to Adam his has lasted for years. I also have a surplus lab hotplate with the stirrer that I want to try as well. So many ideas, so little time.

I did discover a coating for the silk screen side of single sided boards that would also work well for decals for panel labels that are printed on a laser printer.

I found at my local Michael’s store Krylon #7120 Low Odor Matte Clear coating that does not disolve the toner as it contains no Acetone. I place the boards to be coated on wax paper and start with a mist coat and let that dry for 15-20 minutes and then apply one or two more mist coats allowing 15-20 minutes between coats.

I use light coats to avoid having the coating travel into the drilled holes. You end up with an excellent finish that is non glare which really aids in the assembly process. I can use 6 to 8 mil lines with text as small as 1.3mm (about 50mils high) and still get excellent results. I tend to use the Narrow text option in Sprint which works very well for the silkscreen as well as in copper when needed I can also place text (like revision info, dates, etc.) as cutout in copper pours.

One nice feature regarding printouts from Sprint: the print output can be calibrated in both the X and Y direction in 0.1 mil increments to get the printout exactly 1:1. Laser printers are usually very close, but not exact, and many printer drivers only let you change in 1% increments which can be an issue for fine pitch alignment. In addition you can directly import 274-X gerber files and drill or scanned copy input to create a PCB. I typically do this to make the board layout more process friendly and I end up with a totally editable board I can store away as a file to change as I wish. This feature alone was well worth the cost of addmission so to speak. IIRC the cost for a never expiring off line license is about what dinner for four at McDonalds costs these days!

Speaking of copper pours I use them all the time for prototypes as the Sprint software has an auto plane feature you can turn on or off (on the top or bottom layer or both) with a single button click. You can also edit the pour as needed either as a rectangle or any polygon you wish. You can also tie the plane to any pad you wish and also make thermal reliefs for connection that are editable for either board side.

Quite handy if you want a power plane on one side and a ground plane on the other. By default the planes are just floating copper and you can set any global or single clearance you want.

One of the main reason to use the copper fill as it greatly reduces the time to etch the board and it requires less etchant. I generally use 15 mils clearance between the pours and component traces and pads.

One other thing I try to avoid are right angle traces as the corners can become acid traps and that can be an etching issue as well as an EMI issue for faster clock speed boards. 45 degree or angled traces are better. Any place I think I where I need a right angle trace I add a trace at the vertex to cut the corners. Adding teardrops to pads also helps if you happen to slightly mis-register your drill when drilling.

I try to do the same when I am sending boards out as well to keep the yield high. Keeps your board house happy too. I have seen too many boards where tons of 10 mil traces are run where it makes more sense to widen them, especially for DIY prototypes.

One more tip. Whether you are making the board yourself or sending it out copper cost you virually nothing. So if you put in your layout many options for connections for now, or for the future, or for trying out new circuits, just place a patch of pads on 100mil spacing. It’s easy to do this and you’re are paying for the board area anyway as the copper you don’t use gets etched away.

I saved a company I worked for $100K on a project because I anticipated what the customer might need for a future design for an interface circuit. All my company had to do was to populate a couple of parts, re-flash the microcontroller and the current stock of a few thousand PCB assemblies could be used for future production.

Well I think that covers it for now!

All the best to all an 73!

Sam

W3OHM 

@sreaves Thank you Sam….73

@larry_n7luf 

Hi Larry. Thanks.

One more point on board prep. I clean the PCB with a Scotchbrite(TM) pad and Bar Keepers Friend(TM) (AKA BKF) powdered cleaner and scour both X and Y directions. I have never known any kitchen cleaner that does any better on copper than BKF. It is dirt cheap and also works miracles on stainless steel. Great stuff way better than Comet. You can get a can at Walmart for about $2.00. As a bonus your wife will love it if you have copper clad pots and pans like our 50+ year old Revere Ware(TM).

After cleaning with BKF and rinsing throughly dry with a microfiber cloth and then use another microfiber cloth to clean the board with Acetone. Then off to the laminator. Works every time.

All the best!

Sam

W3OHM

Thanks Honza, Ovi & Sam for your replies and advice. 

Exactly what I was looking for – and a whole lot more. So many valuable insights. In the future I may look to adding a “tips and tricks” tab.

It’s interesting to me that after trialling the other methods (CNC, UV resist etc), the toner transfer method is still the preferred method for 2 of you.

Indicates to me it’d be wise to try and sort out the toner transfer method before embarking down another rabbit hole or 3. 

The Kyocera looks like a winner, especially as it appears to be current production, easily available in my region (AU) and has drivers for all current win OS’s/mac/linux…

Thanks again,

I am looking for timing from the printer to the laminator.
Mr. Carlson said in one of his video was around 15 minutes from the printing to the laminator.

Also how much time from the laminator to the etching?
I know MCL is in a hurry, but this old guy has plenty of time, or maybe not.

Just like in the water, can you leave it to long in the water?

Be nice to have guide line to follow.

@honzam 

I do know the issue with Brother and other printers is why PulsarFX decided to go out of business. However you can still find some of their documents on line. I have one of their kits I am holding in reserve in case at some point my process goes south.

A note to Adam Carlson:

Adam:

I have a bunch of files (documents and code) and links that would be useful for people doing toner transfer. Am I allowed to post such things?

Sam

W3OHM

@sreaves ou could post links to where and what they are.

P.S. If someone could archive these files somewhere I could free up my Google drive space.

https://drive.google.com/drive/folders/12-H78abmkvhTr2zz0AmuCGAOfmo1avTn?usp=drive_link

For some reason some of my pasted links appear twice. The Google drive link only shows up once as it should. Anyone know the reason and how to fix it? I only see it once when I go to the edit mode.

@sreaves I have seen the edit problem also.

I have been able to edit after I made a post, but I believe if it has been seen, you can not go back and edit.
Not sure where the edit options stops.

It looks like they still work. At some point I am planning to regurgitate all of my post and add it to the files section (along with the files in the Google Drive Link) to my groups.io SprintLayout group. That way if I get hit by a beer truck the files will be available for all. I make a post when I do that.