Help : Toner transfer on big copper clad 300x200 - Page 1
Forum section: electronics / general

author: XpsikotiX
author_rank: Regular Contributor
timestamp: February 10, 2014, 01:30:13 pm
content: Hello,Can someone give me some tips how to transfer a A4 sheet on a 300x200 board? I tried with a laminator, in kitchen oven with a heavy weight on it , iron .... i just can't do it. So please if someone did something similar and found a way tell me.I cant do the photoresist method, i don't have the materials.Thank you in advance.

author: kizzap
author_rank: Unknown
timestamp: February 18, 2014, 12:54:52 pm
content: What is the issue you are having?If I am correct, I am going to assume that you have tried the iron with the highest temperature.I guess things to check:- The board is clean. Quite a simple one to miss, but will cause 100% of your issues. Personally I will generally use some really fine steel-wool to clean the surface, then wipe it down is isopropyl alcohol, and then try iron on the transfer. Generally I find doing this solves any issues.- second. Try turning up the density of the Toner on the printer: more toner = better transfer (up to a certain point though)- if both of those don't work, try printing on glossy paper, it will help with transfer too as the toner doesn't stick as well.

author: con-f-use
author_rank: Unknown
timestamp: February 18, 2014, 02:14:45 pm
content: General tips:- If you're using ferric chloride to etch, you can make the toner stick to the board way better.Put the board in the Fe-(III)-Cl bath for about 3 min prior to transfer.That will make the surface rougher without dissolving too much of the copper. Afterwards the toner will stick better but is harder to clean off. (For some reason HCl+Peroxide as etchant didn't work like Fe-(III)-Cl in this regard. Haven't tried sodium persulfate.)-Try a different toner.Some toners just don't stick. My original HP worked but stopped after a refill with presumably cheap toner.- Make sure that theboard is fat free(clean it with acetone)and that it is dry(put it in the oven at 100 deg C for 4 min) prior to attempting the transfer.- Run itthrough the laminator 8 times or moreand put it in cold water right after that.- If all else failsuse "Press-n-Peel blue" or "Green TRF" to transferand seal the toner. Makes it more robust and transfer perfectly but is expensive. You can preheat the foils to 50 degC to be sure they're dry and relaxed in its expansion. You can divide the GreenTRF in smaller chunks before applying it to relief stress.For more specifics we'd need your exact process and materials.

author: Psi
author_rank: Super Contributor
timestamp: February 18, 2014, 02:25:08 pm
content: If the temp gets too hot you will notice the paper/pressnpeel/greentrf will expand a little and smudge the image. This is especially an issue with big pcbs.Its usually pretty obvious as you see the smudge expanding outwards from an area that looks goodIt would help us to know exactly what results your getting and in what way is your transfer not working.

author: poorchava
author_rank: Super Contributor
timestamp: February 18, 2014, 03:03:54 pm
content: With board this large I'd say you need to preheat it almost to transfer temperature in an oven or something like that. Then apply paper with the toner and pass MANY times through a laminator or iron at highest temperature.Toner transfer really sucks for making large boards because of thermal capacity of the laminate. Photolitography is much better in this regard (save for the problems with even exposure of large surface)

author: con-f-use
author_rank: Unknown
timestamp: February 18, 2014, 03:22:06 pm
content: Quote from: poorchava on February 18, 2014, 03:03:54 pm

author: ahnuts72
author_rank: Regular Contributor
timestamp: February 19, 2014, 08:14:44 am
content: My first question would be what kind of paper are you trying to use?

author: poorchava
author_rank: Super Contributor
timestamp: February 19, 2014, 08:46:48 am
content: Best paper for toner transfer is glossy paper. You can later remove it very easily using vinegar or lemon juice (vinegar is better).

author: temmink
author_rank: Newbie
timestamp: February 22, 2014, 04:34:57 pm
content: I had difficulties also with the toner transfer on big copper.But in the end, I was able to do so, with the following steps:Use photo glossy paper, instead of ordinary paper. Andfirmlypress the heat source to the paper and the copper for at least 5 minutes (paper starts almost to burn).remove the heat source. Put it in a basket with cold water and let is soak for at least 15 minutes.Then you can gently rub the paper of the copper board.

author: Refrigerator
author_rank: Super Contributor
timestamp: February 27, 2014, 08:52:57 pm
content: I've done toner transfer too, what i know for sure is:Use glossy paper.Print at your printer's highest resolution.Put your iron on it's max heat .Then while applying constant, firm pressure on your iron, rub the paper with a circular motion.And don't forget to clean and dry your copper clad before doing anything.Good luck .

author: chris_leyson
author_rank: Super Contributor
timestamp: July 02, 2016, 12:53:20 pm
content: Thanks con-f-use, just got some Press-n-Peel blue but I like you tip about giving the PCB a light etch to roughen the surface, I will have a go and let know, but at the end of the day from what I've read elsewhere it's all down to the toner.

author: wilhelm
author_rank: Contributor
timestamp: July 02, 2016, 03:15:22 pm
content: Maybe actone transfer. Never tryed it my selfhttps://youtu.be/HBIxvwZ_0oghttp://www.instructables.com/id/Heatless-cold-Toner-Transfer-for-PCB-Making/

author: KL27x
author_rank: Super Contributor
timestamp: July 10, 2016, 09:20:01 pm
content: QuoteCon-f-use gave some good advice. But here's another 2 cents.I have "progressed" through every single thing con-f-use has suggested, myself. It's not a bad place. But1. Don't need to clean the board with acetone. A drop of Dawn dish soap and a wetted stainless steel wool is EZ mode and removes all sorts of gunk. Heck it removes the entire top layer of the copper. It is easy to see what parts of the board are done, and where you have to apply a little more elbow grease. And the soap prevents any residue from readhering to the newly exposed surface. Just rinse, after.2. I agree pre etch is essential. But it only 10 seconds, not 3 minutes.3. PnP takes higher heat than Pulsar dextrin paper. If PnP doesn't work try some pulsar. I have a stack of 30-40 PnP left from my second 100 pack. And it will never be used.4. Multiple passes: A large board is a large heatsink. It is a lot faster and works a lot better to shoot the larger board with a heat gun while it's going through the laminator. I have done the multiple passes thing, and it generally tops out at a point where the preheating is no longer helping. Especially on a larger board where the end is cooling off by the time you can put it in for repeat passes. Once you have (slowly) reached the max temp you're going to get, more passes isn't going to do much. Try heat gun and say goodbye to multiple passes.QuoteIf nothing transfers, at all, you probably have a toner incompatibility issue.

author: KL27x
author_rank: Super Contributor
timestamp: July 11, 2016, 03:52:18 am
content: Theoretically necessary, maybe not. For any board, it can't hurt. For a 300x200cm board, I would probably call it a practical necessity.Pre-etching is not to clean the board. You have to clean it, or it won't pre etch, correctly. The pre etch texturizes the surface, just lightly. After you pre etch, the board becomes completely non-reflective. If you lightly scratch it with a fingernail, you will scratch this away and create a clean, shiny streak.The textured surface holds toner to make it stick better. Dramatically better. And if you apply too much heat/pressure, it gives the surface extra capacity to hold that toner without fattening the trace. Pre etch gives a huge improvement in yield, IME. And as the size of the board goes up, the % yield decreases dramatically.You might as well not bother, at all, if you can't be bothered to do the 10 second pre etch on a board this size... you're shooting yourself in the foot.