Color laser printer suitable for PCB transfer under $500 - Page 1
Forum section: electronics / general

author: Bendba
author_rank: Regular Contributor
timestamp: May 27, 2017, 05:48:38 am
content: Hi,Would anyone have recommandations about printers?I am looking at buying a multifunction color laser printer with the following specs that would be suitable for PCB transfers.- Minimum true 600x600dpi- Duplex (double sided) automatic- WiFi direct enabled, to print directly from android, mainly pdf's- True 1200x1200 dpi scanner- With a decent interface where you can actually set the density of the tonerBig plus would be ability to print A3. I'm hoping to stay under $500~$600 but any recommandation would be welcome.Also, is the any brand that is known to have better/finer toner quality?Thanks

author: Bendba
author_rank: Regular Contributor
timestamp: May 27, 2017, 11:01:16 am
content: Hi,The idea is to replace our two printers (one color inkjet and a monochrome laser) by only one machine.The inkjet cost a fortune in ink as every time you turn it on, it cleans the heads. We are lucky when we get 100 prints out of a $45 ink cartridge. So I would be happy to pay $125+ for a toner that can print over 4000 pages. Plus my wife wants to do some color wood transfers, which work much better with laser ink.For the moment, I have a monochrome Brother MCF-7440N which give excellent results with transfers. The only issue I have is to source some good paper to print onto. Unfortunately, my wife doesn't want to keep the monochrome printer when we buy a new one.Note that the 1200x1200 dpi I'm after is only for scanning, not printing. I only want 600x600 for printing.

author: KL27x
author_rank: Super Contributor
timestamp: May 28, 2017, 08:36:16 pm
content: QuotePulsar. Available at Mouser, Digikey, Newark, and other component suppliers.QuoteThis is too bad. Tried and true good printer... which you can keep filled with transfer paper ready to go... which isn't going to get the wear and tear of all the day to day high volume printing leading to poor transfers... this is money in the bank.Good on finding someone using color laser printer for toner transfer.

author: Bendba
author_rank: Regular Contributor
timestamp: May 28, 2017, 10:00:29 pm
content: Well, the problem solved itself.We found a pretty good color laser printer at a store sale, a Canon LBP7780Cx, which "unfortunately" isn't multifunction. It does a pretty good job with pictures (it want to for $700, even though it was supposed to be a $2500 printer but they were desperate to get rid of it)To bad, well "have to" keep the monochrome one.Now I can make PCB's with color silk screen.And I've got a new organ donor on the operation table.I'll have a try with the new one, to see if it does any good for PCB transfer and let you know, in case someone else is interested to know.I've got another quick question to avoid starting a new subject.Are those photosensitive films you can buy online any good for homemade PCB's? Can you make finer traces than with laser transfer? (I can get reliable transfers down to 10 mils traces and 20 mils apart with toner transfer when I find the right paper)I know you can buy pre-coated PCB's but they are quite expensive.

author: KL27x
author_rank: Super Contributor
timestamp: May 28, 2017, 10:16:38 pm
content: With good technique you can do down to 8/8 with toner, easy. And I would say possible to get down to 6/6 if desperate and willing to make lots of extra and do a lot of inspection/testing.Photoresist can get down to 4/4.. again, with good technique. It is not automatic. Even the pcb manufacturers have losses/discards at 12/12, remember.

author: Bendba
author_rank: Regular Contributor
timestamp: May 28, 2017, 10:23:34 pm
content: Thanks,I'll have a go at that Pulsar paper then. I'd like to get down to 8/10 so by the sound of it, I better stick to toner transfer for the moment.

author: KL27x
author_rank: Super Contributor
timestamp: May 28, 2017, 10:28:51 pm
content: When you do it regularly and use consistent methodology, 8/8 is easy mode. Eyes closed. Will know it works. Biggest problem with toner transfer is smudging/fattening traces. If you use too much heat, you can bridge even 12/12. If you do board pre-etch, this greatly improves margin for error. The texture on the board helps absorb toner and make the transfer stick securely at a lower temp. Also, I have found that the precipitate streaking left on the board after pre-etch is actually possibly the most beneficial part of the process. I have pre-etched boards in advance and found that wiping all the dust off the board (that is left, very loose, after it thoroughly dries) makes the process much more touchy, as if pre etch wasn't done. The toner has smaller margin btn not sticking and fattening.. even separating into two halves... one on the paper and one on the board. The precipitate helps to act as a filler, I think. To absorb toner and keep it where it supposed to be, and in one piece.So I don't pre etch in advance, anymore. Once it dries all the way, it's a dusty mess.

author: cdev
author_rank: Super Contributor
timestamp: May 28, 2017, 10:39:33 pm
content: I would keep the old printer you know works. Ive never used a color printer to print toner transfer. I think a cheap black printer works best.You know what paper works the best for me for toner transfer? The glossy, cheap flyers that come as junk mail, or similar pages cut out of glossy ad-heavy newsprint magazines.In other words, already printed on paper. Cut square with my paper cutter and printed on. Also, it helps a lot if right before you iron it, if you scour the PCB that is about to get the toner pressed into it with steel wool or a wire brush and then wash it with IPA. Then I affix the printed paper with toner on it, with blue painters masking tape and iron it pressing hard. I use a piece of flat wooden board to iron on.Quote from: KL27x onTodayat 14:36:16

author: KL27x
author_rank: Super Contributor
timestamp: May 28, 2017, 10:46:09 pm
content: And lest anyone think I mean to pre etch and then put the acid and grunge through your laminator, no. I mean after thoroughly rinsing in water and drying the board with a heat gun, a fine layer of dust is left on the surface of the board. This dust (and/or perhaps very fragile surface structures which may be smoothed/damaged by wiping?) is important part of the process IME, if you want fine, accurate traces. So don't wipe it off.

author: Bendba
author_rank: Regular Contributor
timestamp: May 29, 2017, 12:11:50 am
content: I just did a very quick try with the new color laser, it works but I'll stick with the old monochrome.The toner of the new one is a lot more sensitive to the heat and a bit light.The fine traces are 10/10 in the middle and 10/20 (ended up being more like 15/5 and 15/15)The thicker traces are 100/10 , 90/20, 80/30,...Lots of smudging but I guess with some more trials, I could work out the ideal temperature and pressure needed. But as said, I'll just stick with the old printer that I know works well.That's more for the sake of putting the information out there.Note that that board wasn't prepared, I only just washed it.The procedure I normally use is the following:- Filing the rough edges where the board has been cut-Giving it a thorough wash with dish soap and a scouring sponge.-Thoroughly rinsing it and wipe it with isopropyl alcohol.-Giving it a very quick etch (I use ammonium persulfate)That does indeed help the toner sticking-Thoroughly rising it without touching the copper. (With demineralised water)-Drying in the oven (90°C) while I go print the transfer and have a snack, and wash my hands again (I found that using gloves doesn't make much of a difference when handling the board with care)-I usually try to find thick glossy paper like wine catalogues or magazines, whatever I can get hand on. I tried proper transfer paper from the store, didn't make any difference except for the price. Print and straight to the board.-I put 3 or 4 layers of paper towel under the board, the transfer on top, one more layer of paper towel (the cheapest I can find, with no indentations in it) and press with the cloth iron.-Giving it a cold water bath with a bit of dish soap to help the water soaking in the paper. I usually don't really care how long it stays in the water, I just go do something else, some stayed a couple of hours in the water.Doing that way, I barely have any fail with 10/20 traces. I did a couple 10/10 but had to do a couple of touch up's before etching.

author: KL27x
author_rank: Super Contributor
timestamp: May 29, 2017, 04:39:14 am
content: QuoteThis is where the pre etch helps tremendously, IMO.When I tried to increase the efficiency of my process by pre-etching a lot of boards in advance, this is where I wiped some of them off with a damp cloth to reduce on the dust. And I got a reminder of why I made the pre etch part of my process. I took some boards out of the etch tank from these transfers that had perfect double width traces all over, like they were designed that way. Luckily, it worked fine with this particular layout, but the difference was striking, like night and day. With the undisturbed pre etch, I have never gotten anything close to that level of thickness increase, and it was just a hint of distortion in specific hotspots. Even heating the boards to the point they start to delaminate and bubble, there is basically no issue.QuoteI'd got it down to where I don't even look at it until it's done etching, anymore. I got a little surprise from this deviation from my normal routine, though.Your process is pretty similar to my own, aside from my etchant is cupric and I use the laminator and heat gun combo. The heat gun will dry a 9x6" board is about 30 seconds, FYI. No need to use the oven. And the cost of the paper is trivial at this level of labor, IMO. I precut the Pulsar into 4.25x3.5" rectangles and and keep the printer loaded.I have tried a couple of glossy photo papers. Other than the PnP and Pulsar, the best thing I ever used was magazine paper. But I am pretty sure I got higher levels of distortion when using magazine paper. Like the paper would shrink from the heat, perhaps. Double-sided boards never lined up the same from one end to the other.