PCBs with powder coat

pcb

The toner transfer method of PCB production should be a staple in every maker’s bag of tricks. That being said, it’s a far from ideal solution with a lot of things that can go wrong, ruining hours of work. [Ryan] thinks he has a better solution up his sleeve, still using heat activated toner, but replacing the laser printer with a powder coating gun and a laser engraver.

[Ryan] is using a powder coating gun he picked up from Amazon for about $100. The theory behind it is simple: particles of toner coming out of the gun are statically charged, and bonded to the grounded copper clad board. In real powder coat shops, this coating is baked, resulting in a perfectly hard, mirror-like finish. [Ryan] skipped the baking step and instead through the powder coated board into a laser engraver where the PCB design is melted onto the copper. After that, wash the board off, etch it, and Bob’s your uncle.

What’s really interesting about this method of PCB production is that it doesn’t require a very high power laser. [Ryan] was actually having a problem with the toner burning with his laser engraver, so it might be possible to fab PCBs with a high power handheld laser, or even a Blu Ray laser diode.

48 thoughts on “PCBs with powder coat

  1. Spraying actual toner around and then pointing a bright laser at the powder-coated piece of shiny metal?This sounds like a great way to get both lung cancer AND blind. :)

    Seems a bit involved, but then, so does etching boards at all. Which is a shame.

    1. He’s not spraying toner around, he’s spraying the powder-coating material. the lasre takes place of the oven and bakes the material on, so more than likely it’s not goign to reflect off the copper

      1. That reminds me of Dayton Hamvention a few years ago. A lot of vendors will abandon stuff that doesn’t sell because they don’t want to haul it home. They like to break things before they leave them, I guess they think that if they leave them in working order people will learn not to buy anything and just show up after the show to collect the freebies.

        Anyway, a few years ago there were some vendors with old laser printers. At the end of the show they ripped the toner out of the ones that didn’t sell and started smashing them on the asphalt parking lot. They were color printers so there were huge clouds of various bright colors. I watched at a good distance. I wasn’t going to breathe that stuff in! I wish I got some pictures.

        I wonder what their lungs look like?

  2. I’ve done the same thing about 5 years ago.
    But i used simple spray paint instead of powder.
    The laser was a Trumpf laser engraver in my company that was normally used to etch labels into IC’s.
    The results are very good, but i don’t have access to a laser cutter/engraver anymore :(

    1. if it can be done with some type of spray paint then it would suddenly become quite available,
      CNC gantries are becoming cheaper and easier to use all the time, if a high power Blu Ray diode could be used then this would suddenly become a fairly cheap pcb fab tool.

      1. making pcbs with black spray paint and laser engraver was already on HAD few years ago
        problem was not everyone has 50W laser engraver/cutter

        1. Bah, people whining again. I’m sure there is a laser engraver at some hackerspace, maker shop, etc… within a reasonable drive. (Reasonable is within an hour, or so, not within a block. Don’t be so spoiled!) I drive about 45 minutes to get access to one and I am thankful it is there!

          1. You’re sure are you? The closest hacker space to me is over 2 and a half hours distance one way. I hear people used to be sure the Earth was flat too. So much for what folks are so sure about I guess.

      1. Because it takes a shitload of power to ablate away the copper. It takes even more power plus some painstaking feed rate tuning to do so without charring the substrate.

        1. How about doing it the other way then… Make a copper clad board, then cover it with a more easily removable substrate more or less what this guy is doing. Then laser away the top layer of substrate and expose the copper clad. I know that’s what this guy is doing, but why is there no commercial options? Especially ones not involving acid.

          1. What is the big deal with acid? Ferric Chloride is relatively harmless, if you don’t mind being orange. Of course few know how to use the stuff right. But it is not really all that hard to heat a bath up, and bubble it.

          2. It’s not just the acid, it’s also the toner transfer process. If you have a laser blast the top away you could do away with the toner transfer too :)

      2. it takes a lot of power and it requires a lot of thermal management, am a copper is very thermal conductive. keeping this in mind it is possible. lpkf makes a system that does this.

  3. This looks like a great idea to me, and I bet it could be done safely if you took reasonable precautions.

  4. I think this hack just begs to be combined with the DIY glove box. Although some type of a pass-through May be needed (visions of a cloud of toner puffing up when the box was opened). Have the lid on the top?
    Would you even need the powder coat gun if you had a static generator connected to the PCB? If you used a static generator you wouldn’t need a copper clad to attract the toner and you could use this for labels.

  5. Could you just dust the copper with the toner and use the laser to melt it onto the PCB and then use the toner as resist? You could then re-use the stuff that didn’t get melted. Not sure how powder responds to being melted with lasers — would it spit and dance around? Or even burst into flames?!

  6. Makes me wonder, could you somehow get into the laserprinter and make it use the raw PCB as ‘paper’ you think? or would the conductivity of the copper mess that up immediately? Or could you perhaps do something to the copper or transfer-roller to make it work anyway?
    Because in the classical transfer method you basically do what the laserprinter did ta second time, and you have to wonder if that’s really necessary.

    1. Turns out the copper dissipates the static charge and the toner doesn’t stick. Someone tried putting sheets of copper-clad kapton film (a.k.a. DuPont Pyralux) through a laser printer, and found that out.

      They ended up having to put it through a Xerox Phaser solid ink printer instead, which works by melting wax-like solid toner that comes in the form of blocks. Direct resist printing! Too bad as far as I know there isn’t a Phaser with a straight-through paper path for thick media, I’d be all over that no matter the price.

      1. I still wonder if you could not prep the copper first btw, some layer that helps keep the charge but maybe melts away when the heating is done, but you’d need to be a materials engineer or chemist to figure that one out. Or have a test setup and lots of samples.

  7. Wow, now that’s an idea! This has a lot more potential than the whole laser-ablated spraypaint resist method, since it doesn’t require much of a laser, and the laser is only setting the image not burning off the whole negative image. I’ll have to try this, but with powder coating media and not toner, because I like having lungs. ;)

    I actually picked up a Craftsman powder coating system (Plugs right into the wall, the gun has its own simple blower built in.) on Amazon for $25…It was on clearance, the MSRP is like $199 or something. It works very well. It’s a shame Craftsman seems to have discontinued it.

    The powder should hold up just fine as resist, the whole thing with cure times and temperatures is to ensure a ‘durable, long-lasting finish’ and whatnot.

    1. Hey John,

      I was thinking that I should’ve grabbed the Craftsman one, but here at the space we have a nice little air compressor perfect for this kind of thing. Let me know how it works out though, since I was wondering how well that one would’ve worked.

      As for the toner vs. powder coat deal, if you breathe either you’re in for a bad time. Which is why I’ve set it up to be done in that small nicely (*coughs*) made paint booth. I don’t have any issue with breathing toner dust with this set up, and the benefit of not having to use aircraft paint stripper (to strip the powder coat after etching) in an enclosed space is a huge plus.

      Thanks!

  8. I speculated years ago that a low power laser would be capable of properly fusing powder coat, but I lacked the resources to try it personally. So I dropped the idea numerous places. Everyone said it wouldn’t work for various reasons.

    Congrats to [Ryan] for showing it works. At least with toner, which is a very close relative of powder coat. Real powder coat is available in a myriad of colors and materials, at least some should work, and some might work better.

    Now who’s going to take it to the next level, and 3D print with powder coat? There’s already some DIY printers out there using water to fuse plaster, cement, or sugar. Mount a 2W diode laser on it, load it with powder coat, and give it a go. The results could put fused deposition to shame. And last time I checked, the price of a pound of powder coat was about the same or a bit cheaper than filament.

  9. I wonder if you could skip the electrostatic powder coating step entirely and just screed the toner with a straight edge using a mylar transparency or a couple strips of tape as a spacer to set the thickness.

  10. A Sharpie pen masks copper clad for etching so I’m wondering why no one has come up with the obvious solution and just used a pen and a plotter?

    1. Y’know, we’ve done that with our old CNC machine (which is currently being rebuilt) and it turns out to be a bit more complicated than that, since the end point of a sharpie is pretty malleable and easily misshapen. On top of that, you don’t get the same fine lines for traces as you would here.

      The bigger question I have is why no one’s been able to get sharpie ink into a inkjet printer yet. If someone could do that, it’d be something to see.

      1. Ever seen drafting pens? Probably not :) Anyhow you should look into them. Maybe don’t attach your pens so tightly to your machine too? BTW there is ink available that resists etching solutions for ink jet printers. Although I hear it has its own host of issues.

    2. Sharpie is better than nothing in a pinch but it really isn’t a very good etch resist. It will start to wash off before your etch is done and you will get pitted traces.

      1. I’ve etched PCBs with Sharpie marker resist. All I can say is that it works here. I can add that most folks don’t know how to etch though. Basically if it takes more than 3 minutes you’re doing it wrong.

  11. This is kinda what I thought when I was working with the TTS. I never could get it work well enough to give it any more time. But from what I DID see was, it would seem to be great if you could just run the copper clad board through the LASER printer and get the toner on that way.

    I never got quite that far, but sort of close and it did look like it would work great. But I didn’t want to take my printer apart and modify it etc…..

    1. Hey! This is a site about hacks, not about recipees! Take your feline derived spices over to the life hacks page!

      1. My apologies, but the headline wasn’t *entirely* inconceivable. Most RF-boards are constructed with varying amounts of black magic, mojo, juju and/or woodoo. This site has an applaudable history of hackers replacing esoteric components and ingredients with common household items, and I do believe cats are pretty common in households! Replacing all or some of the black magic with ground up bits of pet would be a big step forward for hackerdom!

        (Although I suppose it hinges on which BITS of cat would need to be powdered.. Fur could be non-destructibly harvested with a brush, and I think that would be preferable for the casual hobbyist)

  12. Why hasn’t anyone started a kickstarter to make an opensource inkjet pcb printer? I can’t because I don’t live in the USA, but someone should do it. You could also print front panels for your projects. There has to be a cheap source of inkjet heads somewere.

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