Etching Your Own PCBs At Home

Etching your own PCBs from copper clad board is nothing new, but the ability to make your own circuit boards at home is so useful it should be part of every maker’s repertoire of skills. The folks over at Hub City Labs in Moncton, NB, Canada put together a workshop covering the basics of home PCB manufacturing, allowing any maker to put a circuit board in their hands in under an hour.

The process starts just like any PCB design – laying out traces, parts, and vias in a PCB designer such as Eagle. When making your own boards, it’s a good idea to make the traces and pads extra large; the folks at Hub City Labs follow the 50-50 rule: 50 mil wide traces with 50 mils of seperation.

The PCB design is printed out with a laser printer (in mirror mode) onto a piece of paper from a glossy magazine or inkjet photo paper. After the copper board is scrubbed to remove any oxidation or oils present, the design is laid face down on the copper and heated with a clothes iron or sent through a laminator.

After the laser printer toner is transferred to the copper, the recipe calls for etching the board with a solution consisting of a half cup of 3% Hydrogen Peroxide and a quarter cup of muriatic acid.

The folks at Hub City Labs put together a great tutorial for one of the most useful skills the home electronics wizard can have, but etching your own PCBs is an art unto itself. There’s a lot of ways this process can be improved, from using Kapton tape to secure the printed art to the copper board, to getting high-strength peroxide from a beauty supply store.

If you’ve got any tips on making your own PCBs at home, drop a line in the comments below.

EDIT: Good job killing Hub City Lab’s web server, everybody. They’re working on getting something up.

79 thoughts on “Etching Your Own PCBs At Home

  1. I’ve even had success with regular printer paper! This is useful knowledge for poor uni students who can only use the university’s printers (i.e. they cannot load their own paper types).

    However, I find that “press ‘n peel” is the fastest, since you can peel it off straight after ironing/laminating, and if it hasn’t transferred yet, you can just keep ironing :).

  2. I prefer scotchbrite pads to wire wool. It’s much less messy and the dust doesn’t rust and stain the kitchen sink. A wipe over with IPA or better still acetone will get the last traces of finger grease off the copper. Toner hates grease and won’t stick to it at all no matter how hot you get it.

    I tend to chuck the hot board straight into the water so it sizzles briefly. Magazine paper disintegrates with less effort that way and the toner is more likely to stay intact.

    Giving the toner cart a shake before doing the print helps even out the toner thickness, especially if you’ve been doing lots of PCBs recently. Thin traces splurge into their neighbours less by setting the printer darkness to normal or slightly dark rather than maximum darkness. Not rubbing the clothes iron about too much and buffering the back of the magazine paper with a piece of brown paper helps with this too.

    Having said all that, I find making PCBs at home a real PITA and I wish I had a better way to do it.

    1. I haven’t found time to do it yet. But I have access to a Mantis: http://makeyourbot.org/mantis9-1
      Only with a Dremel instead of a motor.

      I have done some reading on it, and I think it will be less messy then working with chemicals. The real tip came when I read that you need to put some oil on your PCB, this catches almost all the dirt.

      1. Thanks for the link. Interesting read. Milling PCBs is not for me though. There’s not a chance that would be able to handle a 0.4mm pitch footprint. Even if the frame were stiff enough, a cutter going much less than 100k RPM would tend to tear fine copper traces off the board.

      2. Totally incorrect on both accounts. While I can’t speak to this particular mill, 15mil trace width is no particular challenge, and 100K RPM is almost unheard of.

        Many sub-$10KUSD professional PCB mills run at ~30K RPM spindle speed and have sub-1mil resolution.

        I suspect that an appropriately outfitted Makerbot-class CNC could do this without much difficulty at all.

        Getting the PCB to lay flat and true is probably the biggest challenge, because that’s what gates your tool life — ripping up as little FR4 when milling as possible.

        1. If milling was the way to go then that is how industry would do it. The industry uses chemical etching though which should be in and of itself telling. Many folks look for “easy” solutions that doesn’t mean all offerings made to them are good solutions.

          If milling is going to be feature competitive with etching then some machine specs need to be improved over minimums or limitations are going to outweigh benefits.

          Increased spindle RPMs is a reasonable place to start. 30K RPM would get you to maybe 30 mils with the size bits you could effectively run.

          The smaller diameter bit you want to run the higher RPM you have to run it at. This is the basic relationship of tool surface speed to tool rotation. (PI X DIA. X RPM) / 12 = SFPM (Surface Feet per Minute)

          (3.14 X 0.03125 X 30000) / 12 = 245.45 SFPM

          By rights milling copper you want 300-700 SFPM but I’ll give the benefit of the doubt and say that at a slow feed 246 SFPM will cut the mustard so to speak.

          At 100K RPM spindle speed the math gets a lot better. So nes is right on with their estimation even if they use the lame metric system. 0.03125 is of course 1/32 of an inch expressed in Imperial decimal metric.

          for laughs I’ll figure out what RPM they need to go to get the pitch they’re after. 72,765.786 RPM to get 300 SFPM @ 0.015748 of an inch diameter or 0.4mm which is about 1/64th of an inch BTW for all of you metric weenies who may want to reform to a man’s scale so call it 73K RPM

          Isn’t math fun? Tangible numbers beat unsubstantiated opinions any day.

      3. I suspect that an appropriately outfitted Makerbot-class CNC could do this without much difficulty at all.

        Please feel free to post any links to back that up, I’d love to be proved wrong. A 0.4mm pitch footprint requires ideally track width and isolation between tracks of about 7.5 mils. I think repeatability, stiffness, spindle run-out and required cutting speed puts that well outside home brewed and hobbyist-grade machinery, but it can just about be done with a 1200dpi toner print transfer.

    1. I taught myself before I was in high school. Although I’ve gotten a bit better since then. None of that is to say that there is not still some room for improvement for me yet.

    1. Bubbling is the way to go. People against bubbling just have never tried it. It is worth the $9 it takes to buy a crummy 12V compressor to rig one up. Instead of a stone I use the top off an old spray can. It seems to make nice bubbles to me. Although the acid bath did eat out the white atomizer center in the head. It just makes slightly larger bubbles now. For a bit I kept on changing them out for new cap heads, but then I was like the heck with it. It’s fine. I think I may even prefer it making bigger, nastier, more aggressive bubbles with the missing center.

    2. Agreed! And oxygenating the acid (if you’re using the above solution of hydrogen peroxide + HCL) will help maintain its etching power since it uses up oxygen to etch. When my solution turns from bright green toward brown I just pop the aquarium pump in the bottle for a couple of hours and it brightens back up, ready to etch. Used the same bottle of etchant for years.

      Warming the acid helps speed things along as well. It doesn’t have to be a lot, a hot water bath for your etching tank or just shining a light bulb on it.

      (Wear your safety goggles when working with hot bubbling acid.)

  3. Now I’m going to sound like a complete ass but really, how many more tutorials do we need on the same subject? There are TONS of tutorials saying the exact same thing in both written and video form. If the different tutorials at least added something it would be fine but they’re just regurgitating the same info over and over. Enough already.

    Also, 50mil traces minimum? Jeebus, that’s gargantuan, you can and should aim for better results than that.

      1. I know, but my comment still stands :) Really, it’s not that difficult to get well below that, you just have to take your time and do it proper. I’ve done traces down to 10mil without much fuss with the toner transfer method.
        Here’s an example:
        http://i.imgur.com/wuDmI.jpg

        That said, it’s so inexpensive to have boards professionally made these days that I don’t bother unless I need the board NOW.

      2. Nice straight edges there, sneakypoo. Mine always come out more raggedy than that and .4mm/15mil pitch or .25mm/10mil trace width is right on the limit of what I can do at home with magazine paper and a clothes iron. So, go on… how are you doing that? :-)

        http://imgur.com/YxIcO

        I always need my PCBs right now. Otherwise things never get done. ;)

      3. This reply is for nes but it seems I can’t reply to his comment… weird.

        I don’t really do anything special. I do use some fairly expensive paper made specially for toner transfer (that I’ve forgotten the name of right now) but it works just fine with normal glossy catalog paper as well. The only difference is that the special paper comes off clean and normal paper may need a bit of clean up (so laziness was the driving force there). I use a laminator these days but I used an iron in the past with no trouble other than it’s a bit more fiddly.

        I use sodium persulfate as the etchant. I never measure anything, I just pour up by feel. I use two plastic containers for the etch, one just holds water (boiling hot), the other is placed inside the first and has just enough water and powder to cover the PCB. Then I use a pair of tweezers to hold the board and slosh it around a bit in the solution. It goes pretty quick so you need to keep a close eye on it so you don’t over etch.

        So yeah, just your basic toner transfer etch stuff, nothing special.

      4. @sneakypoo
        > That said, it’s so inexpensive to have boards
        > professionally made these days that I don’t
        > bother unless I need the board NOW.

        Really? I find that the set-up and artwork costs for a 1 off board is still prohibitive, for example, a 100 x 50mm single sided board without solder mask and without silk screening would be around $25 – you have found somewhere that’s substantially cheaper than that?

    1. Also the next part: “Fatten up those pads. 50 mils drill holes, and 75 mils diameter.” What?! (32 mils would be a more reasonable hole size, and you really want the etched hole smaller than that to help guide the drill.)

  4. I’ve been using Iteadstudio’s service for a while now, and I’m very positive about their price / quality standard. I recently even ordered with DHL shipping which meant I ordered PCB’s for $15 and added $25 shipping; had the PCB’s within 10 days; double sided, with soldermask, silkscreen, smallest drill 0.3mm and 0.8mm PCB thickness.
    I ain’t etching no more…..

  5. I’m JF from HubCityLabs, super happy that we’ve been featured on Hack-A-Day, but the unexpected attention killed our web server. We’re trying to get something back up ASAP so you can all view the post.

  6. I’ve etched a few boards starting with the rub off transfers I got from Radio Shack many years ago. Then I tried the toner transfer method using a product called P&P Blue. I ruined 2 toner cartridges using that stuff so I cannot recommend it.

    So far all I’ve used is Ferric Chloride as my etching fluid. I’ve found if the fluid is fresh and I heat it up and agitate it with air I’ve gotten excellent results. Of course if all of that is not happening results can be less than satisfactory.

    Right now I do not have a working etching setup, I broke my heating pan when I moved and still haven’t replaced it yet. Plus I have not come up with a new way to mask art onto copper clad board either. I’m done with the toner transfer method. Even under the best case scenario that method is too limiting.

    I’ve plans to work up a better system for making my own printed circuit boards one of these days. But I won’t use any of my old methods, transferring toner, or using FeCl either.

    BTW you only have to reverse a mask you put on the top side of a printed circuit board. The process of transferring the toner reverses the pattern all by itself.

    One tip I have is for an air agitator. Initially I used my large air compressor with a regulator but in the course of moving I’d moved it so I had to come up with something else. What I came up with is in fact better than using a big compressor.

    I had this old 12 volt compressor lying around so I pressed it into service as my air bubbler and it worked great! It put out just the right volume at just the right pressure and the fact that it put out air so unevenly in a pulsing fashion was even a plus.

    I used an old tire stem with a piece of hose jambed into it and the cap off a spray can on top so I didn’t even have to mess up the 12V compressor. I guess I could have just cut the tire chuck off it though.

    In any event if you haven’t tried air bubbling while etching you should give it a shot. It way beats rocking the pan. By beats I mean etches come out cleaner, and faster (like 10 times faster 2 minute FeCl etches are average), let alone saving you from the hassle of manually rocking the pan.

    Trust me once you start bubbling you’ll never go back to rocking.

    1. The method I use for agitating is to use an old fish-tank water pump. I cut the filter part of it off and it sits nicely in my etch tray gently circulating the liquid. It works really well.

      1. I wouldn’t think a pump not designed for it would work too well for acid. Or does the “water” pump not actually pump fluid through it? In any event 12V tire compressors are cheaper and easier to get.

      2. A tip that I’ve just discovered… put the freshly pressed board in the freeze once it’s cools a little from the iron… it seems to help the toner stick to the copper before peeling the paper off.

  7. Nice tutorial. I too have no issues doing 10mil traces at home with the Pulsar Pro FX (http://www.pcbfx.com). It’s cake. Their blue transfer paper is superior in MANY ways to magazines or even photo paper. Itypically do a single prototype board this way, then if all is good I’ll get a batch made from iTead Studio. $25 for 10 professional boards is a steal.

  8. what you use for etchant doesnt seem to be as critical as your transfer medium and technique. i found the peroxide-vinnegar-salt solution to work best for me. its cheap and you can get 2/3 the ingredients with food stamps.

    good transfer paper is hard to come by i think, ive tried photo paper and special toner transfer paper and nothing works very well without being extremely thorough with ironing.

    my two tips are to print as dark as your printer will let you. moar toner == better transfer. and my second tip is to iron thoroughly and with good heat distribution and pressure.

    also i decided to dive straight into dual sided boards, and i have to say that there arent a whole lot of tutorials about alignment techniques and making vias on the cheep. i ended up just connecting vias with bare copper wire soldered at both sides. and my alignment is good enough for through hole work, but im sure there are techniques that are superior to what im using. i definitely need to improve my techniques before attempting any smd work.

      1. I’ve had some success by printing both sides out onto photo paper, then using a very bright light source to align them by hand.

        Then it’s simply a matter of keeping them aligned while you slip the copper board in between each side.

      2. I print the two sides aligned on one edge with about an inch gap between them. Then simply fold the paper over, hold it up to a light to check alignment before creasing it. Slip the PCB inside, iron on and you get perfect alignment every time.

      3. i drilled some alignment holes in corners of the board and printed a little crosshair on each layer. they were rotated 45 degrees between the layers. i built a jig out of legos with bright leds lined up with the holes. i taped the bottom layer first and then aligned the top layer, using a magnifier i lined it up so the lines converge into a single point. it took a lot of tweaking and was about a millimeter off, but its good enough for through hole work.

    1. To align double-sided boards:
      Add two small pads or vias your board, one on the upper left, the other on the lower right. Don’t connect them to anything.*

      Tape the top mask to the cladding and drill those two holes. Put pins through the holes and use them to align the back-side mask with the same holes. Tape in place, remove the pins, and apply your mask to the cladding. Should be able to get around 10 mil accuracy this way.

      *You can also use vias near the edge of the board. Most pad holes are too big and lead to sloppy alignment.

    1. ^– This method achieves 10mil traces no problem, and even a first-timer can do 24mil. I’m a bit surprised more people don’t do UV exposure. If you have access to a laser printer anyway, it’s just as easy to print to a transparency, and you just plunk the presensitized board under your desk lamp for a few minutes and you’re done. Sure seems easier (and more precise) to me than messing with wet magazine paper and clothes irons. To each their own, I guess!

      1. + 1

        I too don’t understand why people don’t use the photo resist method. I have found it to be fast and reliable.

        However, I do have access to a vacuum table to expose the board (this makes certain the transparency is tight to the board).

        For repeat-ability and reliability I don’t think it can be beat.

      2. I sandwich the acetate and the PCB in an old picture frame. Works great!

        Maybe people just don’t realize how easy using presensitized boards is, and they do the toner transfer thing because it seems to be what everyone else is doing? I dunno, I’m baffled by it. In my opinion, UV exposure is quicker, more precise, and about the same cost.

      3. Presensitized boards FTW!

        I built a deep wooden box with a piece of glass on top. In the bottom I put an array of UV leds. This way I’ve eliminated all the variables and can use a timer for further consistency. I develop boards in 2 min 30 seconds.

        It also works to develop screen printing screens for making t-shirts and front panel graphics. Same exact method – printing transparencies from a laser printer.

        You can buy large panels of presensitized boards and cut them down. The best tool I’ve found for this is a cheap diamond blade tile saw. The water keeps dust down and the diamond blade won’t dull.

      4. It’s simply the cost of the pre-sensitized boards that makes this undesirable for many people, and I have to agree. The process itself seems to clearly be a win, if you can stomach the ~4x cost of the boards.

      5. @ericwertz

        “It’s simply the cost of the pre-sensitized boards that makes this undesirable for many people, and I have to agree.”

        Even if it is just a hobby, do you not put value in your time? I do, always.

        Do you factor in the cost of failed boards? Replacement PCB, toner, etchant, electricity [for the iron] (If you value your time and factor in all the costs for toner transfer then photoresist boards are ten times cheaper than a ‘half baked’ (pun intended) solution.

        Using photo resist you make one transparency, and from that you can make 1 board or 1000, they are all EXACTLY the same, there are no failed transfers….

        To each his own I guess.

      6. You are kidding right? Whilst I agree photoresist is a superior method it’s cost is prohibitive for home use. For instance a Riston PCB – 152 x 152mm board costs $25. Add developer, etchant, etc. and you are well over $30 – it’s cheaper to get it made.

      7. The cost of those materials (developer, chemicals) will make hundreds of boards. They are all almost infinitely reusable. And as per my Jameco links, presensitized boards are only 2$ more expensive, with no effort to shop around. My etching chemicals are vinegar and drugstore disinfectant- pennies per board. The developer basically lasts forever. I’ve been using the same batch for years.

        There of lots reasons to choose various PCB methods, but low cost is a primary reason I chose UV. YMMV.

      8. my reasoning is mostly cost. most of this is brought about by the fact that i live in a small town on an island in alaska. and shipping companies dont like to ship anything other than ground. compound that with the fact that we dont have a single chemical shop anywhere withing a 100 mile radius. its quite sad.

        i kinda want to do photo-resist, but im under the impression that you need more chemicals that i cant get. its bad enough i buy my etching supplies at the grocery store (with food stamps).

        another technique i like is the spraypaint+laser cutter method. i want to get one but its that or a 3d printer. and that is if i can swing one at all.

    2. Possibly, but if you are NOT making hundreds of boards you have to amortise the cost over the amount you are doing – the quantities available for purchase are fixed. But again the major cost is the pre-sensitised board: http://www.jaycar.com.au/productView.asp?ID=HG9970

      If you are making hundreds of boards you are probably doing it as a money making concern in which case all bets are off, it’s a completely different scenario and the purchase of professional equipment becomes viable especially because you can write the capital cost off to tax.

      For occasional home hobby use I maintain they are economically unviable.

      1. The stuff doesn’t go bad, though. I’ve bought one set of supplies for making me PCBs, and have been making boards for a couple bucks a piece ever since. Over the years, it’s surprising how many boards I find myself making. I haven’t found a fab house that can make a board for less than $25, and it takes weeks.

  9. Umm… They recommend buying acetone for board cleaning, while you are buying your hydrogen peroxid and hydrochloric acid.

    Not a good idea to buy them all at the same time, or they may think that you plan to be the next “underpants bomber”. The DIY explosive popular with terrorists is made from exactly those same three ingredients (but usually a stronger H2O2 for bleaching hair).

    The people who “protect” us are watching for those things purchased together. Better to buy these ingredients separately if you do not want to draw attention to yourself.

    1. Right, because we all know that they can’t track what you purchase over time.

      Better not by pc board, or wire, or timers, or …

      Whatever.

      I dare “The people who ‘protect'” to come to my door, my attorneys will have a field day with that.

  10. I have recently optimised my toner transfer process. I have found temperature measurement is key. I heat a cast iron pan bottom side up on the stove to 175 oC, measured with the thermocouple on my multimeter, and apply pressure with a rolling pin. This works well for HP laser printer toner at 600 dpi. Pretty much any kind of glossy paper seems to work OK to print on. I clean the board using cream bleach then rubbing alcohol, not steel wool.

  11. where’s the best place to order the board in the U.S. I used to get scraps from my school for free but now have been shopping around for a good supply. Also what thickness of copper works best for this process?

  12. We really need a PCB milling machine that has decent trace resolution for 2-sided copper clad boards but also a new thin multi-layer thin sheet layer able to be laminated or glued together and then drilled through holes and then solder connect each layer on the through holes connecting the circuit boards all in one. I envision a paper thin layer each having a high dielectric film coating on one side and a copper foil layer on the other side for end milling out traces and pads. Then we stack them up and apply glue or some heat to make single piece with multiple circuit layers to be connected by through holes that are able to be soldered together as jumpers. We are so handicapped without fine trace and multiple layer capability.
    Any ideas?

    Another BIG idea, what we need is a spiral winding coil winding machine that twists the wire as it is being wound onto transformer bobbin core for use with any length of wire – twisted pair that twists as it comes off the spool and before it winds onto the core.

    1. Personally I value acknowledgement over visions. I accept limitations and work within them to achieve goals.

      I’ve had the PCB milling argument so many times I’ve boiled it down to this, if PCB milling was any good the industry would use the process. But for good reasons they don’t, so neither do I.

      If you want pro results it is wise to try to copy the pros as best as you can. I’m not saying what you suggest is impossible, merely that it is impractical.

      1. I value your input because it addresses observed limits by someone who has experience. So, following your lead, do you think it is possible to copy the pros in a DIY scaled down pcb processing plant in a way that is able to become affordable for joe sixpack and sally housewife?

        1. One must often accept a tradeoff between cost, and ease. The most costly method is to send your boards out to have them done, but nothing could be easier. Results are often excellent too. I’ve hand masked PCBs and etched them too. Depending on the design of the board art that might be challenging to do though. But it is very low overhead to get into.

          For a while I was using the toner transfer method but results were too erratic for me to continue doing that. I’ve seen some folks that have mastered the techniques but I’m afraid I’ll never be one of those.

          The last bunch of boards I made I point to point wired, and skipped etching entirely. That experience has rekindled my interest in etching.

          Now I want to do photo-resist. I’ve heard it is worth the effort. Done well one can achieve state of the art results with the process. So I figure that has to be worth striving for.

      2. Just to clarify, the ‘industry’ doesn’t use etching to make PCB’s. They plate. The cost of recovering all that copper would make etching insanely expensive.

        board milling is great for rapid prototyping or one offs. It can save a few turns with the PCB house, which at a week a turn can mean the difference between making a deadline and not.

        On that note, I’m still looking for a good way to make plated through holes at home. It can be done, but it is really painful.

        When doing RF work, many plated through holes are needed in small areas, often with a component mounted on one side or another, so feed through wires are difficult at best.

        1. Thank you Komrade. I was remaining optimistic for your point of view. You state the problem and solution in context with the average DIY joe who just wants to put the model before the theory like we used to in the old days.

          This may sound extravagant. The idea being plasma ark deposition. Imagine a common hot plastic extruder used in the 3D printers like makerbot. Are we able to replace the heat extruder and ABS plastic spool with a HV spark from a 20kHz flyback transformer and a spool of thin copper wire that is controlled by a robot arm or a 2-axis plasma ark extruder arm? What type of substrate could we use for the PCB that is non-metallic or non-conductive at lower voltages?? and yet remains impervious to humidity, static and such? Maybe there is a way to make this as yet undetermined substrate a thin-film that is able to be sandwiched into multiple layers with glue unto hardened PCB able to be drilled and soldered.

          I hope I am not too far from reality with my wishes. Ken Shoulders is an expert on these plasma ark interactions if I’ve generated an interest. So, hv anode and cathode fixed distance with room for a thin film substrate in between the plasma electrodes depositioning copper ions into the target substrate from very thin, i.e., #36awg, copper wire spool. Next glue these thin films together for multi-layer pcb.

          Michael

        2. I’m going to have to call you out for a citation on your claim that, “the ‘industry’ doesn’t use etching to make PCB’s. They plate.”

          The industry does indeed plate through holes, and tin onto copper traces, but I’ve never heard of plating being used to apply traces to substrate.

          The profits are so insanely rich no one is worried about recovering any copper. Not that it is so difficult to do. But it isn’t stopping anyone from cashing in either.

          Board milling is never great. At best it can be called adequate in limited circumstances. I’ll admit I haven’t machined a whole lot of copper in my life but I’ve cut enough of the stuff to gain some appreciation of just how differently the material cuts. Even drilling copper presents special challenges. Anyone that has ripped a pad off a board knows that!

          Copper has a tendency to grab, and stick unless special tool geometries are used. Maybe all of the board millers have some secret cooling lubricant they use? But if they do it isn’t apparent based on reading I’ve done on the topic. Things like warnings to check boards for shorts because of copper’s tendency to string during cutting. Messy stuff …

          I’m glad you brought up RF work because RF is one place where you really don’t want to run boards with jagged trace edges. But you just keep on beating the drum for PCB milling komrade.

          “can mean the difference between making a deadline and not.”

          Article headline, “Etching your own PCBs at home”.

          I don’t know about you Bob, but I don’t have a clock on my wall here I’m punching. That must be a communist thing… Past that I’ve successfully etched PCBs in 2 minutes. Milling is not faster than that for all but the most simple designs. Certainly not for the kinds of boards I make.

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