Toner Transfer Papers

[mvs sarma]

As you are from UK,
RS Components, MAPLIN, Element14(Formerly FARNELL) catalogs are not new for you. the type of thin papers worked well for me.

i generally print a normal print on A4 paper.
Later i use the cut piece of special paper from catlogs mentioned, and stick it at the sides using 3M magic tape. now take a dark print and manage toner trander and when put in hot water
the paper from a magazine / catalog gets soaked and releases out easily.

 

[throbscottle]

I know the thread is old now, but
WHOOHOO!
After experimenting with all sorts of things (including home made dextrin coated paper) I got some transfer paper from china - the yellow stuff that's all over eBay. Cheap and works like a charm, even very fine tracks between DIL pins came out, first attempt. Just peels straight off too.
Just need to improve my technique now to get an even transfer...

 

[Mosaic]

Hey Throb...
This is for u, it works with parchment paper.....can't beat the price and availability of parchment!
https://hackaday.io/project/3363-apache-al13p-laminator-one-pass-pcb-toner-xfer

 

[throbscottle]

Cool, you've improved the write up since I looked at it when you first posted the link in the other thread. It looks like I would be hard pressed to find one of those Apache laminators in the UK though even if I could afford one, so I would have to try another make/model.

 

[Mosaic]

Just a useful update using yellow 'chinese' toner transfer paper:
**broken link removed**

Works very well. Here are some pics, sorry abt focus...macro issues.
Toner transfer: Note the porous fill. Smallest parts are 0805 with 12 mil detail traces. 1 oz copper 4" x 6" PCB.

Foil Transfer: Porosity gone. Used 'everyday' craft foiling paper

Etched: Blue 'film' flakes off during this process, no biggie. I taped off the copper that is to be cut off to save etchant. (I use HNO3)

 

[throbscottle]

Can you explain what is "craft foiling paper"?

 

[Mosaic]

This is what I use...instead of 'green' toner reactive foil from pcbfx
https://www.ebay.com/itm/Heat-Toner...ansfer-/160937797413?var=&hash=item2578a3e725

 

[throbscottle]

I might give it a try. Didn't you find that the metal in the foil reacts with the etchant?

 

[Mosaic]

Foiling is a common means to offset toner porosity when etching, I have not seen any reaction with the etchant.

 

[mvs sarma]

This is what I use...instead of 'green' toner reactive foil from pcbfx
https://www.ebay.com/itm/Heat-Toner...ansfer-/160937797413?var=&hash=item2578a3e725

But the FX green tr-foil leaves the pit holes as it is and doesn't cover them.
Does this new Chinese roll cover that>
if so we might end up in drill holes also covered by same materiel !!

 

[Mosaic]

If u look at the pics u see the foil covers the porous toner but not the drill holes etc. Works fine.
Unless you have porous pits the size of drill holes!

 

[mvs sarma]

Thanks Mosaic. But the seller has a list of restricted nations
let me try

 

[throbscottle]

I found the same kind of thing on the UK versions of eBay and Amazon - it's a widely available product.
I think you've probably made the first novel contribution to the toner-transfer knowledge base for a while, Mosaic

Bit of an update from my own usage with a clothes iron (plain toner, no foil) - less heat gets better results. This is with Konica-Minolta toner. I'm using the iron set to a bit below 100°C now. I also discovered that the cheap acetone I've been using leaves a residue, so it's no good for wiping the board down pre-transfer, but it makes it even better for afterwards because it resists corrosion!

 

[throbscottle]

whoops, hit quote instead of edit!

 

[Mosaic]

PCB prep: I sand with 220 grit and clean with 90% + Isopropyl and Bounty paper towels. I also clean my fingers with the alcohol to prevent re-contamination of the boards with finger prints.

Apply toner transfer, apply foil transfer, etch, sand again (lightly) with 220 grit to clean the copper and wipe down with acetone to remove toner remnants.

If I am doing double sided boards there are additional steps to place registration pin holes for aligning both sides of the toner transfer, but the toner transfer and foil transfer are applied to both sides simultaneously.

This project has proven invaluable in perfect (toner & foil) transfers every time:
https://hackaday.io/project/3363-apache-al13p-laminator-one-pass-pcb-toner-xfer


I also use a Full Spectrum 5th gen, 40W Hobby laser to make reusable solder stencils from stock 3 mil laminator sheets (comes with the Apache laminator). Simply export the (top or bottom) Cream layer from EAGLECAD and raster cut at 50% pwr & 50% speed.
The stencil for the board shown before took about 5 mins to make and about 5 mins to apply the solder paste. Clean the stencil with laundry detergent and a dish sponge.

Here are some more pics of the progress: This is another PCB from the same project.
Applying paste via laminate sheet stencil:


Paste results:



Assembly in progress, FR1 board so the 300°C hot air 'browns' it a bit: Only took 10 mins to solder, faster than using the solder oven.

 

[mvs sarma]

many thanks Mosaic, lovely and clear explanation and photos.
Your have reached a stage of near perfection.

 

[Mosaic]

I thought I'd summarize my process in one location for convenience and sharing. Plus it permits me to add improvements as time passes.
So here it is:
https://hackaday.io/project/7938-pcb-smt-maker-lab-home

 

[jpanhalt]

Hi Mosaic,

Very nice results for toner transfer.

All methods I have seen require a very clean board that water flows smoothly across. Several years ago (>10), I tried a different approach borrowed from a technique used in microbiology. Basically, the problem is to get bacteria in a water suspensions to stick to a glass slide for staining. Simple heat fixation doesn't always work well enough. The solution was to add something that would act like a glue for the bacteria to glass. That something was a dilute solution of albumin (1 to 2%). I think almost any protein would work, so years ago, I tried simply dipping an "as received" PCB in a very dilute solution of gelatin (egg albumin would also probably work), let it dry, then tried toner transfer to it. The coated and dried PCB looked like the uncoated side, but water wet the surface easily. While it is probably possible to have too dilute a protein solution, just be sure the solution is dilute enough. The toner seemed to stick to the treated board well. I did not take it through the etching process.

Someday when you have time to waste, you might want to try it with a piece of scrap PCB board.

Regards, John

 

[throbscottle]

That's interesting. I made some dextrin a while ago so I could try making dextrin coated paper. I wonder if an extremely dilute coat of that would work the same?
OTOH, it does dissolve very easily so could wash out from under the toner and possibly muck up the etchant.

 

[jpanhalt]

I don't think that polysaccharides (dextrin or dextran) would fix with heat quite the same way that a protein would. Nitrogen is generally a stronger Lewis base than oxygen.

John