Toner Transfer-I'm so stink'n close, but... - Page 1
Forum section: electronics / general

author: Dan Moos
author_rank: Frequent Contributor
timestamp: May 06, 2016, 03:56:21 am
content: I'm trying to find a consistent toner transfer. I'm so close! I get 80-90% perfect transfers, but can't quite get a usable one. Whats aggravating is that alot of the finer stuff (20 mil traces, 20 mil clearance) comes out great, but I'll get a 50 mill trace with missing bits, or pads that are no good. Heck, my edge cut lines which are really fine come out good. Its like my method is good, but execution is spotty.Ok, what I've tried.Photo paper. Comes out great from the printer, worst at transfering.Magazine paper. The opposite. Really good transfer, but the prints are inconsistent.I use a green scratch dishwashing pad to rough up the board. Alcohol for the final clean. I have dabbled some with alcohol on the print, but that seems to not matter.I also tried coating the board with acetone to sorto loosen things up. No help. Pre heat is no help.I have gotten some decent improvement using another copper clad board between the iron and the paper for a more consistent heat. My board is about 6x6".I'm this close to making the plunge into the photo method, because I really don't want to fight this every time.Any thoughts?

author: Bud
author_rank: Super Contributor
timestamp: May 06, 2016, 04:33:23 am
content: I used this Digikey P/N with good results (8 mil trace)http://www.digikey.ca/product-detail/en/pulsar/50-1101/182-1003-ND/3386followed by this (seals imperfections in transferred toner)http://www.digikey.ca/product-detail/en/pulsar/50-1225/182-1021-ND/653189EDIT: I also used a laminator with them, I could not get good results with just an iron.

author: Dan Moos
author_rank: Frequent Contributor
timestamp: May 06, 2016, 01:41:46 pm
content: What do I look for in a laminator? Its gotta be cheap, because otherwise I'm just gonna spend the money on building a light box and getting photo method supplies. Are the 20 dollar ones I see ok?My uniformed concerns about the laminator method are:Can an un-modified laminator take a typical thickness piece of FR4?Is double sided tricky? Do you run it through with 1 paper first to get it to "stick", and then add the other side?I'm not worried about having to send the board through many times if it allows me to buy a lesser laminator.I really don't want to modify one, but maybe its not as big a deal as I think to do so?

author: tggzzz
author_rank: Super Contributor
timestamp: May 06, 2016, 02:16:10 pm
content: I haven't tried thishttp://www.instructables.com/id/Heatless-cold-Toner-Transfer-for-PCB-Making/?ALLSTEPSyet, but it sounds interesting.

author: ion
author_rank: Regular Contributor
timestamp: May 06, 2016, 03:19:37 pm
content: The laminator I use for PCBs is a pretty cheap one, in fact I had it before I started to make my own PCBs. If you can get one that can take the board thickness you shouldn't need to modify it - passing the board through 4 or 5 times is less of a hassle and you can still use the laminator for it's original purpose.The best way I found for testing the maximum thickness a laminator can handle (without destroying it) is to send a few sheets of paper through and if they pass without problems add a few more sheets until it you reach the PCB thickness or the laminator starts to struggle. The cheap one I have goes well beyond the specs and handles PCBs without modification.That said, I was only using the toner transfer method as a stopgap while I gathered the supplies for a photolithography setup. I know there are those who swear by the toner method, but for me the success rate with the photo method is much, much higher (once the exposure settings are dialed in). The laminator is still useful though for applying the photoresist when I'm not using pre-coated boards or to apply dry film solder mask.

author: charlespax
author_rank: Regular Contributor
timestamp: May 06, 2016, 06:21:37 pm
content: Some years ago I used a small laminator for toner transfer. It worked very well. I used to pass the PCB/paper through several times to make sure the PCB heated nice and evenly. This seemed to give in the best results for me. From what I remember I used a clay coated paper from Staples.I think the biggest factor affecting my results was the thickness of the toner. I was using laser printers that I had scavenged from office park trash (e.g Apple LaserWriter). If you can use a good printer, I'm sure you can get high quality results.

author: KL27x
author_rank: Super Contributor
timestamp: May 06, 2016, 08:17:26 pm
content: I consider myself fairly accomplished in toner transfer.The laminator helps. I use a GBC laminator that cost 30ish bucks. Been doing the job for many years with no end in sight. I shoot the board with a 1200 watt heat gun while it's going through.But the two single most important things are:After cleaning the board off with dishsoap and stainless steel wool (the green scrubber you use is perfectly fine, too), you HAVE to pre etch the board. When I say, you HAVE to, it's because you can get away with not doing it on a simple board. 19 times out of 20. But the one time you screw up it will waste more time that it takes to just do it every time. On a large board like what you have, you really HAVE to do it, if your time is worth anything!The pre etch is just a dip in your etchant. Leave it for 5 or 10 seconds, is all it takes. This pre etch is also a proof of how well you cleaned the board. The color will change when you pre etch it, and it shoudl be fairly uniform. If you have grease spots, you wil see it. If all good, then rinse in sorta clean water and dry the board with a heat gun. If you get some streaks of copper salts on the board when you dry it, no problem. This does not affect the process adversely, at all.The pre etch gives the copper layer a microtexturized surface which makes the toner not only stick better, but it also reduces squeezing/fattening of traces. Even if you handle the board (moderately and with clean hands!), after, your finger oils won't be enough to ruin the transfer.The second important thing is to use Pulsar dextrin coated paper. It's a dollar fifty a sheet. Or thereabouts. Again, you can use magazine paper or what not. And it might work 19 times out of 20.... but that one time it fails is a huge waste of your time! (You know what I'm talking about. It's harder to scrub off a bad transfer than it is to clean the board in the first place, let alone the registration and other setup/rinsing/drying!)Do these two things, and there is almost no way to screw up a transfer. I have figured out every single way of screwing up a transfer, in the name of saving time/effort. These two things are not worth screwing with. Just do them! (Yeah, I've used magazine paper, I've used PnP blue, I have wasted 60.00 on various photo papers, and I have trashed a laser printer all in the name of science).The other things to watch out for is to not leave traces all alone. Bundle them together and/or use a ground place when possible. A long trace running around by itself won't etch at the same rate as the other traces.

author: tautech
author_rank: Super Contributor
timestamp: May 06, 2016, 08:57:12 pm
content: This ^^^^I might add that things change and I've been caught out changing to a higher DPI printer, the toner melting and leaving messy transfers. Paper that works with one printer might not work with another printer toner combo.Started with an old HP 6MP @ 600DPI and waxy backings from self adhesive label sheets and a laminator, gone to an OKI @1200 DPI to overcome trace and polygon pour porosity.All this leads to frustration and now I soak papers off but still using the higher DPI printer to get around porosity in traces.Good enough for the odd PCB I do now.Glad to see the OP is not yet pushing the boundaries of TTquite a bit less than 020 is easilyrepeatable with TT when you've got everything sorted.

author: Dan Moos
author_rank: Frequent Contributor
timestamp: May 06, 2016, 11:26:23 pm
content: Ok, I'm gonna try the pre etch trick for sure. Dextrin paper will have to wait until I get some.Can anyone refer a cheap thirty dollar or less laminator that will for sure take the thickness? I can't test one that's an internet purchase, do I kinda need to know before I order it.Using a heat gun in tandem with there laminator was mentioned. Do you.just hit it with the heat as it feeds into the laminator?

author: tautech
author_rank: Super Contributor
timestamp: May 07, 2016, 02:55:37 am
content: Quote from: Dan Moos on May 06, 2016, 11:26:23 pm2 passes through the laminator is what I found is simplest to overcome the heat soak of a cold PCB.But I do use a medium thickness card pouch that came with my laminator so it would be ~2 + mm before it enters the laminator.These pouches are sewn at one end, that's the end I feed first and no doubt it eases the step up on entry and provides better traction for the feed rollers than FR4 PCB.BTW mine's a Rexel LV250 that I've had ~20 yrs.

author: tggzzz
author_rank: Super Contributor
timestamp: May 07, 2016, 10:21:05 am
content: Quote from: Dan Moos on May 06, 2016, 11:26:23 pmWhy not also try the IPA+acetone technique? You probably already have those lying around, so zero cost and could try it todayIf you do, please let us know how you get on.

author: Psi
author_rank: Super Contributor
timestamp: May 07, 2016, 10:29:17 am
content: i got good results with a layer of cork sheet between the paper and the iron.I think it was 0.5-1mm thickCork is a bit soft, It squashes down under the iron to keep the sheet flat on the pcb.The cork does tend to smell a little though, when it gets hot.There is probably a better material that has better heat conduction. But cork seemed to work ok for me and it was cheep.

author: KL27x
author_rank: Super Contributor
timestamp: May 07, 2016, 10:00:14 pm
content: QuoteMy GBC Creative couldn't handle full thickness 0.064" boards, out of the box.1. Take it apart.2. The holes in the plastic that hold the top roller, just egg them out with a Dremel to give the roller more height adjustment. And then put it back in and put the spring clips back on3. Put back together.QuoteWell, I took the plastic cover off my laminator and just screwed the thing down to a plank of plywood, so I can move it around while it is hot, and it won't tip. And then after that, I just wave the heat gun around the top of the board as it's going through, right at the point it enters the laminator.To get super detailed, after the board is prepped, I make sure it is preheated before running it through the laminator. So with the board nice and warm all over, I know it's going to stick pretty well. I run that through the laminator without heat. The I do a second pass where I shoot the board with the heat gun as it's going through, waving the gun back and forth and necessary.Depending on the size and thickness of the board, you will have to make adjustments. It's totally possible to overheat a small board and make the toner run and bleed into the paper.I know when a board is done by how hot it is when it comes out the other side of the laminator. A full thickness board, anyway, should be so hot when it comes out you that I can only hold it by the edges. If I pre etched the board and the board passes this "too hot to hold" test, then it's pretty much 100% gonna be good when I dunk the board and peel off the Pulsar. If you get it way too hot, some of the toner will stick to the paper, but it will still be ok (the transfer will still be good, just slightly thinner in some spots). So it's better to overdo the heat than to under do it, with my setup.

author: DimitriP
author_rank: Super Contributor
timestamp: May 07, 2016, 10:35:14 pm
content: QuoteMy first thought is that's it's your printer's "fault".Take your PCB pattern as a PDF to officemax and ask them to print it on glossy inkjet photopaper (theirs or yours from the dollar store).Try transfering the pattern to the PCB and see if you get better results.I preheat the PCB in the toaster oven and use a paper towel between the iron and the PCB.If you dont like it or need to reuse the PCB , use acetone, the whole thing will wipe right off almost like wiping off dry erase markerYou might end up in the market for a different laser printer instead of a new transfer method

author: KL27x
author_rank: Super Contributor
timestamp: May 07, 2016, 11:30:15 pm
content: While I'm at it, OPFYI, you don't need alchohol or acetone to clean the board. Just put a drop of dish soap on your scrubber, wet the board, then scrub the board in your kitchen sink, using a cutting board. When you've scrubbed the whole surface, rinse it off. Then take it still wet to the etch tank to do the pre-etch.When the final etching is done, a lot of people will use acetone to remove the mask. I suggest you use your green scrubber or to get some stainless steel wool. The steel wool removes the mask very quickly and will also remove and shine up the pre-etched surface. Acetone will leach carbon black from the toner into your board, permanently, and you will still need to polish up the board, after, to remove the pre-etching (and the embedded salts in the etched surface).(I kinda doubt it's a printer problem, if you are getting 80-90% good transfers. That result is pretty typical for lack of attention to details. )

author: Dan Moos
author_rank: Frequent Contributor
timestamp: May 09, 2016, 02:45:58 am
content: I JB Welded the stripped out drive gears. Gotta wait for it to cure, but JB weld is good to like 500 degrees F, and its not like I'm sticking two pieces together. Just need the D shafts of the rollers to not spin inside the gears.I think this laminator will work fine now that its modded and fixed.I am using a Brother printer, which I know are said to be no good, but I'm getting like 95% or better transfers. That says to me that the printer is fine. I haven't even tried to pre-etch yet, but I plan to in the end. I want to slowly change the parameters with each attempt in order to more fully understand what is and isn't helping.

author: tautech
author_rank: Super Contributor
timestamp: May 09, 2016, 04:12:33 am
content: Quote from: Dan Moos on May 09, 2016, 02:45:58 amWise move.

author: forrestc
author_rank: Unknown
timestamp: May 09, 2016, 08:18:24 am
content: Quote from: Dan Moos on May 06, 2016, 03:56:21 amNot exactly what you're asking, but back when I was etching my own boards, I gave up on toner transfer and moved to photo resist.The boards weren't all that expensive pre-coated with the photo resist. I'd print the circuit out on a transparency (you know, like for an overhead projector), and then use that to expose the board. It wasn't all that picky about what you used to expose the boards - mainly you needed something which put out UV. Once they were exposed, you'd put the board in a developer and then after a while, rinse the board in cold water to stop the developer and get rid of the unneeded resist. At that point, you etch just like your toner transfer.Nowadays, I couldn't even start to envision messing with making my own pcbs. It's just too cheap and easy to have them made by one of the batching places. I'm glad to hear there are people still bothering with doing it themselves though.Oh, one more thing, circuit specialists has all the stuff you need to do the photo resist pcbs, including good prices on pre-sensitized boards.

author: MT
author_rank: Super Contributor
timestamp: May 09, 2016, 04:05:48 pm
content: Quote from: Dan Moos on May 09, 2016, 02:45:58 amI have been using a HL2030 for years and years for my panic.."holiday again"..pcb's, among many other printers likeHP, OKI, Canon etc and the Brother produces better results most of the time, some Hp L5/N etc was slightly better butregarding Brother's its about setting printer driver to massively dark, eco-saving off, along with intensity slider maximum.I have done repeatable 5mil tracks with the Blues Brothers but you need to tune the process, paper and laminator is part of that.Toner has higher melting point then laminating sheets so you need to modify the laminator temp regulator.make your own dextrin paper!https://paulwanamaker.wordpress.com/how-to-make-dextrin-coated-paper-for-the-toner-transfer-method-of-making-pcbs/

author: KL27x
author_rank: Super Contributor
timestamp: May 09, 2016, 06:59:56 pm
content: QuoteIf it doesn't stick, maybe there's enough room to drill and pin the gears, somewhere.QuoteI honestly can't imagine photo resist being any easier or cheaper. Unless you need a bit higher resolution, I think toner transfer is easy as it gets, and it just happens to be dirt cheap, too. There is just a lot of shoddy information out there on toner transfer. It's so much cooler when it SOUNDS easy, and when it's using FREE magazine paper and the clothes iron you already have laying around. If you want it to be efficient, it's possible, but most of the info that is out there is half-assing things. There are tutorials from accomplished folks which I would suggest, if you watch, you do absolutely nothing the way that they do it in their video.Ordering boards is easy. Toner transfer is something I use mostly for quick and dirty lab equipment/tools, prototyping boards to clarify function of certain parts of a larger circuit so I don't have to spend an entire dev cycle waiting to find out if I am doing it right, and for certain pcb's that would be expensive to order. As an example, I sometimes find it useful to make pcb's on 0.007" FR4, and you can't order that kind of board from anyone. To go that thin, you have to do flex circuits, which is not cheap in proto quantities. If the board is so complicated that it will take me several days to do the BOM and order the parts and I'm making dozens, then it doesn't matter. But if I can slap it together and start using it, today, maybe I will toner transfer. It takes about an hour or two to do a board, including the etch. If the number of holes is low, anyway. Most of that is like cooking. Just getting things ready and waiting and putting things away when done. The actual labor parts is maybe 20-30 minutes.