Toner Transfer, does this sound feasible? - Page 1
Forum section: electronics / projects

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: November 22, 2015, 09:02:14 pm
content: I scrapped a microwave the other day to build a 220 step up transformer... in this microwave I found 3 different ceramic type heating elements. If I were to attach a flat piece of metal to the top of one of the heaters and wire a light dimmer to it to control the tempature, would it be feasible to use this as a toner transfer to copper clad. I would imagine if you could apply the right pressure pushing down on the board without it moving you could get a toner transfer dead on first time every time? I know about 175c is how much heat you want to give it but how much pressure and what length of time?Ive tried this with an iron twice and gave up it was such a waste of time and never worked right, but im sure that is a heat and pressure problem. I know OSHPark is cheap but if I could pick up a clad board at RS print a design and wait 5 minutes then etch it would be well worth it for prototyping.

author: janoc
author_rank: Super Contributor
timestamp: November 22, 2015, 09:24:17 pm
content: Just get a $10-15 laminator and be done with it. The results will be much better than anything you will get from this contraption (or a clothing iron)and it will not kill you in the process.

author: KL27x
author_rank: Super Contributor
timestamp: November 22, 2015, 09:54:52 pm
content: The reason a laminator works well is because it has spring loaded rollers that only have to apply heat and pressure to one line on the board at a time.For your press to work, you would have to apply a ton of pressure on a larger board, using maybe a hard rubber for the other surface to make sure it applies pressure, evenly. And once your press was finally up to temp, it would be silly inefficent, unless you wanted to "stamp out" dozens of boards. By that point, it might be cheaper to buy them from china.QuoteMake sure your toner is compatible. Some toner (Brother, for instance) has a much higher melting point and is completely impractical for toner transfer. If your toner isn't working, try another printer.FYI, I have used regular paper, photo paper, magazine paper, and the hundreds of sheets of PnP blue before this dextrin paper was commercially available. And it's so much better it's a steal. Give it a try. The time it takes to pop out a board is the biggest investment in the process. So even though it's "expensive," the cost per square inch is still neglible for a pcb, and this cost shouldn't even register on your radar. (I never tried the laser printer backing, though. That might be pretty good, if you want to try it.) Once I tried the dextrin, I didn't look back. I still have maybe 30 sheets of abandoned PnP blue sitting in a closet, somewhere.Super important is the pre-etch. A lot of tutorials call this optional. It is, if you want to waste your time. Pre-etching not only gives the pcb a better surface for the toner to stick, it also gives it micro nooks and crannies for the toner to run into, rather than fattening out and widening traces. If you are making only a square inch board or less, or huge traces, yes you will get a decent yield without it. If you are making a large board, you are shooting yourself in the foot to skip the pretch. In the course of making hundreds of boards, I have tried to skimp on any and every part of the process as possible. This is not something worth skipping. Dip board for 5 seconds, rinse, and take 30 second to dry it with a heat gun.My GBC Creative laminator cost around $30.00 back in the day. I forced several 0.062" boards through it. Many of them needed to be pushed through to avoid being stuck, before I finally egged out the holes holding the roller, to allow for more thickness. The plastic gears are still not complaining. And the laminator still works 100% on 0.007" thick boards. The cover is removed (so I can shoot the boards with a heat gun while they go through), and all the wiring is exposed. It sits outside where it is exposed to humidity after it rains, and to corrosive fumes from my etch tank. I run many pre-etched boards through the laminator before they were completely dry (don't do this barefoot standing on wet ground or concrete!), while shooting it with the heat gun to dry and preheat the board; so it has been exposed to trace corrosive salts from the pre-etch/rinse.I bought a backup, because it seems like it should have died a long time ago. It's been doing the job for many years with no end in sight.QuoteIf you buy manufacturer waste/cut-offs from Ebay, you can get copper clad for dirty cheap. There is a broker selling all kinds of sizes. Any size and thickness you would ever need.

author: KL27x
author_rank: Super Contributor
timestamp: November 22, 2015, 11:10:23 pm
content: QuoteI have a Brother laser printer. My third one. The toner in my Brother laser printer is definitely different. Or the fuser does something to it to MAKE it different after it's on the paper.QuoteI didn't do any scientific testing, other than the Brother prints did not stick to the copper or smear, at all. My unscientific observation is that Brother printers and toners are great for what they're designed to do. Brother probably uses more than one type of toner in their lineup of machines, or maybe you were using a non-Brother replacement cartridge. Another non-scientific observation is that my Brother printers draw a huge amount of amps to heat up before printing a doc. I assume the toner melts at a higher temp, but something else may be making the difference.Before I bought an HP, I found I could use my Brother if I dumped the toner and replaced it with a generic refill (which was specifically stated to be compatible with this model Brother printer). Night and day, clear difference. (Call that an unsubstantiated anecdote from a dubious source, if you want. But if you want to get the MythBusters involved, pass along my info, and I'll donate my printer.) But within several months, my printing went to pot and wouldn't work for documents, let alone toner transfer. I don't know if it was because of the replacement toner or because of the clay coated magazine paper I was running through it.I have spent over $50.00 on various photo papers and haven't found any that work. Most of them worse than regular paper. I don't think photo paper is an urban myth.QuoteThis would be completely dependent on how flat your iron is and how large your board. If the surface of your iron had any raised surface on it or your board is small, then the pressure you are putting might not need to be much, at all. But as the board size increases and if you are planning to press a plate down without moving around any pressure point, I would imagine the pressure would increase proportionally to the size of the pcb. If you can transfer a board the size of the iron, without moving the iron around, then I would think you have proved something. I don't think it should require a lot of pressure, technically speaking. But the efficiency of heat transfer is going to be related to the pressure in this application. And you will need a minimum amount of pressure that will fuse the melted toner into the copper over the entire surface, allowing for non-perfect surfaces. If you press a 6"x6" plate on a 6"x6" pcb with 50 lbs of pressure, some of those spots are getting much less, and some spots are getting much more. Without moving the plate around or using a compressible backing, it may prove challenging. The other thing the laminator does is ROLL. Sliding an iron around might increase lateral smearing.QuoteThat sounds about right. And maybe that's a better way of looking at it. A laminator allows a more controlled heating by focusing the temperature at a tiny spot on the pcb at a time. The thickness of the board matters. The width, not as much. And the surface area is taken completely out of the equation. I have solved the problem of multiple passes by shooting the back* of the board with a 1200W heat gun while it's going through, to get the pcb hotter at the point where it's going through the roller. My tried and true process is run through once to stick the transfer, and then run through one more time with the heat gun. And it's kind of like cooking a pizza. Depending on the width of the board and the thickness of the board and copper pour, I give it more or less "cooking" with the heat gun to avoid smearing the toner.* For doublesided boards, I shoot the front on the second side. It doesn't seem to make a difference. But I always shoot the back on a SS board.

author: Aodhan145
author_rank: Frequent Contributor
timestamp: November 23, 2015, 12:54:10 am
content: Quote from: blueskull on November 23, 2015, 12:47:11 amI love actually the process of making the PCB it is quite interesting and I like watching it developing and etching away the copper. I like making my own because with most boards I can design them one day and make the board the next no waiting 2 weeks! I make PCBs instead of using stripboard or perfboard for my prototypes, its really fast and easy.Try doing the UV exposure method sometime. Ferric Chloride only costs £4 then the developer costs another couple of pounds. The actual clad is cheap if you look for it. Then all you need is a UV lightbulb or an ordinary CFL one. It is worthwhile to experiment with, It costs nothing.

author: hendorog
author_rank: Super Contributor
timestamp: November 23, 2015, 01:11:42 am
content: Quote from: KL27x on November 22, 2015, 11:10:23 pmMy cheapo brother laser printer worked well. It did take quite a bit of trial and error.I've only used a brother printer, so can't offer a comparison. My suspicion is that it just behaves differently but can be made to work.Cleaning with a green plastic pot scrub and pre-heating the board helped. I used thin, weak glossy paper from advertising pamphlets that fill our mailbox constantly.If you can't get enough heat for your toner, then maybe try this:http://www.instructables.com/id/Toner-transfer-for-PCB-Flamethrower-Style/?ALLSTEPS

author: Unknown
author_rank: Unknown
timestamp: November 23, 2015, 01:20:40 am
content: Quote from: KL27x on November 22, 2015, 11:10:23 pmThis. Specifically, the toner used in the Brother & OEM carts for HL-2270 & similar printers (TN-2250) is a different composition to most others. I posted a link previously to the MSDS that backs this up; it lists an unstated proprietary component where other toners have all named ingredients.That said, my partner bought a carton of cheap white-box 'compatible' toner carts for our 2270. Theydomostly work, but the only time I've tried them was with some 2oz board that took a lot of preheating and more transfer time/pressure than usual, and ended up with a fair bit of spreading. The downside is that the compatible carts don't work nearly as well for printing tracing paper transparencies for UV (not as dark & more pinholes).

author: KL27x
author_rank: Super Contributor
timestamp: November 23, 2015, 01:33:58 am
content: QuoteDo your pcb providers charge per piece, as well as by area? (Very tiny boards may be expensive?)Some of the boards I will make with toner transfer are tiny pcb's just to alter boards I already ordered. If you make a board that is 0.007" thick, you can solder it directly over pads on another pcb. Like a jumper that can carry components on it, to reduce the number of wires needed. Most manufacturers seem to charge more for 0.02" boards, and that's often the thinnest they go. And the min charge for flex seems to be around $90-$100.Sometimes I have even designed boards with a spot where a 0.007" board will be installed, to carry some components/switches, or whatnot, in an area that spans some existing traces. A poor man's multilayer board.But even in general, I do a lot of my simple SMD boards with minimal holes using toner transfer, particularly if I'm not going to be making scores of them, because it's rather easy. Takes 30-40 minutes or so to get the board into the tank. No double/triple checking Gerbers/schematics. No sweating the details. Make it, and if you have an oops, no problem.

author: KL27x
author_rank: Super Contributor
timestamp: November 23, 2015, 01:46:33 am
content: I'll check them out. Most of my orders are for high production, and I'm using a couple places in China.A lot of the cheap low volume places are putting a max of 1 circuit per panel. So making a tiny pcb and putting several on a single "pcb" would be breaking the rules.I don't need a manufacturer to make me 5 of a tiny pcb when I can make 100 of them in 30 minutes.