66% or better

Printed circuit board etching

pcb

This isn’t meant to be the definitive PCB etching post. I don’t have any experience etching boards and was hoping readers could contribute their best/favorite methods for etching boards in the comments.

We’re linking to Tom Gootee’s page on toner transfer etching. The first step is to print the design on glossy paper using a laser printer. An iron is then used to transfer the toner to a prepped copper board. The board is then soaked in etchant to remove the exposed copper. The printer toner is mostly plastic and resists the etchant. Once the board  is etched, Acetone is used to remove the toner. Tom has been keeping his site up to date and as his research progresses.

Comments

  1. Don says:

    I’ve been trying to find some information on building a PCB spray etcher. Although transfers and board preparation are important i’ve found that that only way to get really sharp clean lines is to use a spray etcher. Unfortunately commercial units start at $1k and go much higher than that. Anyone know of any good resources?

  2. Oh man i had looked for these instructions once and never found them. thats crazy. Thanks for the post. He talks about the show “Strange Days”. I happened across that episode for no particular reason but on that they used aluminum foil as the etch and copier toner to transfer the pattern (i think).

    This is perfect for the budding builder in us all that cant afford the cost or the equiptment for commercial boards.

    BTW. Rss: Broken. Again. Stuck two back.

    Hal

  3. Jared says:

    Same here, rss feed not working again.

    And, wow! I had never really considered etching PCBs at all, but if I were going to, I would use this guy’s instructions!

  4. Itay says:

    I’ve used this method successfuly. It’s cheap and pretty easy. Just have patience and it’ll come out great.

  5. Thomas says:

    I’ve used Gootee’s site for making PCBs.

    The process works great. I’ve made several boards using this process. Even the first board I hade with it worked.

    Beware of the double-sided copper clad board Radio Shack sells. I tried one of these, and it didn’t stand up to the heat of ironing. Something under the copper vaprized, which bubbled and popped the copper layer open.

    I used the recommended Staples paper with good results. However, a recent update to the site says the Staples paper might be different now.

    I bought a Dremel drill press (requires a Dremel tool) for drilling holes. It works great. Drilling the holes without a drill press is nearly impossible. I bought my drill bits at a hobby shop.

  6. pretorious says:

    after making a few, the hardest part is still drilling the holes. I would definitly recomend the above mentioned dremel press. be sure that whatever you are using to do the designing leaves a center hole in each copper pad- it makes the drilling process go much faster.

  7. Philippe says:

    I did some pcb recently (with surface mounted stuff) using photographic method. I’ve never had any success with toner-transfer.

  8. jc says:

    #5, that’s the glue that bonds the copper to the fiberglass. Apparently, whoever sources the material for RS uses a glue with a really low melting point (or your iron temperature is *way* too hot).

    However, I’d suspect the material, since *everything* Radio Shack sells now is complete garbage.

  9. tns says:

    i’ve used this method countless times, and the only problem that i’ve found with it is trying to make two-sided boards. the pattern transfers perfectly to the first side, and then the pattern will transfer perfectly to the second side as well. the problem is that when you iron the second side on, you melt the toner on side one and totally screw it up.

    i experimented with trying to pattern both sides at once by using an iron on a stove, and ended up cooking the copper right off the board. it was a simple mistake of having the oven on too high, but it was costly… burning copper/fiberglass smells like cat piss… i later measured the temperature of my iron and stove with my multimeter, and the iron was around 400f if i remember correctly, but my thermocouple melted and disappeared at around 900 (and climbing) on the stove…

  10. Rob says:

    I have been doing my own PCBs for some time now.
    I have found the photo-etching technique to be the most reliable and yields excellent results (even though it can be slightly more expensive).
    This involves printing the PCB pattern on a transparency. This transparency used to tranfer the image to the board using UV light (I use a fluro light).
    For drilling I first use a small centre punch to make an indent in the board. Then I use a small arlec drill I have to do all the holes, this seems to be the most reliable method I have found short of having a proper drill press.

  11. acceptable Risk says:

    I’ve used a similar method in the past. My method differs in a few ways.

    -I’ve used an inkjet printer with no problems despite what Mr. Gootee claims.

    -I tend to just use glossy magazine/catalog paper to print my patterns onto. Way cheaper than photo paper.

    -I wrap my PCB in a very SLIGHTLY damp towel when I iron the transfer on. The moisture helps keep the heat even and almost completely prevents burning. Also I’ve never had a need to use hot water to peel the paper off, maybe it’s because I use the damp towel.

    -I usually just float the board on top of the ferric chloride, copper side down. Put a little piece of tape on the back to use as a handle and use a light touch and the surface tension of the solution should hold it up. It probably takes longer than bubbling/manually agitating the solution, but I’ve never had any problems.

    Really the way I’ve done it isn’t so different from his, but his directions seem overly complicated/specific. There’s probably some reason for it. He probably gets better results than I do, but I’ve done plenty of SMT work on boards done my way so it’s good enough for me.

  12. foobario says:

    I find photographic transfer to be less work and higher quality than toner, but you use what works for you. In my experience the toner process can give uneven results with very small pads/traces… undercutting gets to be a problem.

    To make drilling easier, change the shape of your through-hole pads from circles to donuts… with the metal already etched away from the center of the hole, the drill-bit is self-centering.

  13. jc says:

    I’m curious about you folks doing this. Considering the cost of having PCBs made professionally ($65 for 5 pieces, 2 layers, up to 100 square inches, http://www.pcbfabexpress.com), why would you mess with making your own?

    I’ve made my own PCBs by hand (in the old days, before inkjet printers and the internet), and given the materials cost, the somewhat unpredictable results, hassles of drilling, lack of good silk screen, and the over/under etching for very small pads, why do this?

    This is a serious question, not a troll. Given that you’ll spend nearly as much in money, and far longer in time, why go this route?

  14. Saf says:

    Well jc you do make a good point, if we wanted professional pcb for our projects it would be make sense to have it made for us at a cost.

    But do you really think thats fun?, also i rekon it would be cheaper for mass production pcb making to buy the materials and make them yourself, i mean to make a few hundred pcb or go and pay $65 per 5 pcb’s, which do you think is cost effective?.

    Annywhoo, back in school days, i did electronics for a g.c.s.e and the only method we were taught was the u.v light method, was simple and quick for double sided pcb’s, they had this special made uv box, was basically a sandwich maker with the insides taken out, then 4 uv bulbs were placed into it (2 on the top half, and 2 bottom), then perspex was cut to size to make a nice flat surface on both sides. Then all that had to be done was track printed out using a laser printer or inkjet (the school had nice hp laser jets, and were far more crisp and precise than inkjet prints)
    Line the pcb and track up then lay it into the uv box, close and switch on for a minute or so, and hey presto nice precise pcb in a matter of minutes.

  15. mc says:

    I’ve done this before, it works well but it does take some practice to get a perfect board every time. for drilling the holes, i bought a few dozen high-quality new pcb drills from a guy in sweden who got them at auction from a pcb house. i have a dremel mounted in a homemade cnc machine, export the drill locations and get everything centered, then let ‘er rip. for double-sided board you need to have something to wick the heat away a little from the already-transferred side. i’ve also tried building up a sandwich with toner-transfer on both sides, ironing a little and flipping until everything’s stuck on. the toner method also doesn’t address through-hole plating, a process that is doable at home but requires a large amount of chemicals and time. i find it much easier to use component leads as vias when possible, and for additonal vias you just strip a foot or so of wire and loop through all the holes, solder both sides then snip off the excess. lacing the wire through the holes keeps it in place so you can solder a bunch of vias in one shot.

    you also have to consider professionally-made boards, especially when doing really fine-pitch smd and important projects. i have used, with great results, http://www.olimex.com double-sided solder-masked through-plated silk-screened and free cutting 6.3″x3.9″ for $33. they will panelize it into as many boards as you can fit, plus they will combine multiple files onto one boards and cut them apart, free. they are in bulgaria and it can be hard to get your credit information to them, but very good results.

  16. Xaph says:

    acceptable risk: can you elaborate? I too, am plagued by the lack of a laser printer. Your post is the first time I’ve heard of anyone transferring to PCBs using an inkjet.

    Any special settings you use? How good is the quality of the result? Does it work with ammonium/sodium perchlorate etchants? By “wrapping in a towel”, you mean you place the paper with the pattern on top of the PCB, then wrap the whole thing in a towel, then iron through the towel? If anyone else has heard of this, please advise, since I’d really like to try this out.

  17. thomas says:

    #12,

    your point is well taken.

    i use it because it is cheaper and faster for me. not including whatever my time is worth, i can make a board with this method for a couple of bucks. i can make one of these boards in a few minutes as opposed to waiting a few days for a board to arrive by mail. also, quality usually isn’t an issue, and i usually only want one board.

    if i wanted more than one copy of a board and/or excellent quality, ordering them makes infinitely more sense. the toner transfer method is really just for quick prototyping and tinkering as far as i’m concerned…which is about all i do. ;-)

  18. monster says:

    don’t photocopiers use laser printing? i thought i could print on a standard piece of photo paper and then put it on a transparency with a xerox machine. (i would use the UV method, since my photo class has a darkroom and lights that are connected to timers, giving me precision control over the exposure time.)

    it’s a lot like traditional film printing, although it’s more like a contact sheet (click on my name ^^^ for a definition) than an enlargment

  19. kyle says:

    i’ve only used this method once, and it was the first time i made a pcb myself. i found that if you’re careful and patient it can work pretty well. i dont have a laser printer either, but i just printed it out at home on regular paper and photocopied it onto photo paper at staples using their machines. it worked, but i dont recommend photocopying it if you need high precision. i also found that his muriatic acid/hydrogen peroxide mix worked pretty well. using this method i was able to make a small pcb for about $4 out of pocket (although i had some of the stuff before i started).

  20. §ean says:
  21. Dingo_aus says:

    What do you do to protect the copper traces? Do you need to go over them with sodler to tin them or is there a better, less intensive method of protection?

  22. foobario says:

    #12: “Given that you’ll spend nearly as much in money, and far longer in time, why go this route?”

    It’s not a given. You’ll spend nowhere near as much money, but you will spend much more time. Some of us have more time than money, so this arrangement works out very well.

    My initial setup cost about the same as getting some boards made professionally. (Tank with bubbler, heater, and thermometer, light box for photo method, chemicals.) Since then it’s just been the cost of materials: I’m making 2-sided boards for around $2US each.

    I’ve had some boards made professionally, but making them myself feels good, saves me money, and gives me something constructive to do with my time.

    Plus, what sounds better: “I made this” or “I bought this”?

  23. Ryan says:

    I’ve used this method to make several PCBs over the past several months. I use it because I have more time than money (yay college life) and because I can do it in my apartment without needing to carry around any bulky equipment (etching tanks, etc) that I wouldn’t need already.

    To etch double-sided, here’s my strategy: Do the toner transfer on one side. Then take it to the drill-press and drill out several of the holes. Then I take the other side’s pattern and poke through the equivilant holes with a sewing pin, and hold the board and not-yet-transferred page up to the light, sliding it around until I get it positioned just right so I see light through all the holes I drilled. Then I iron that side on and etch. Works like a charm.

    Does anyone have a source for the Dremel drill press? It would be nice to use my Dremel rather than relying on being able to get time in the scenery shop in the theater department here. ;) I’ve googled around from time to time but the drillpress attachment seems to be discontinued (unless we’re talking about some inventive use of the tile cutter attachment?)

    Also, what do you guys use to cut your boards? I’ve been using a bandsaw, but that’s probably not good for the boards or the bandsaw..

  24. jc says:

    #20, I’m surprised your cost per board is that low, given what I see double-sided copper clad going for around here.

    As far as ‘Plus, what sounds better: “I made this” or “I bought this”?’, my primary enjoyment is in the design and CAD work, and the finished product. The time consuming tedious parts (purchasing components, making PCBs, and to some extent, assembling them), just don’t do much for me.

    After all, when you say “I made this”, did that include fabbing your own ICs dies and packaging them? :)

  25. Rich says:

    I photodocumented my first attempt at the toner-transfer method. It worked great. I haven’t added notes yet, but it’s pretty self-explanatory.

    http://www.shatterscape.com/gallery/My-First-Etching

  26. reboots says:

    I’ve tried Mr. Gootee’s technique with several different photo papers. The best I’ve found is also the cheapest Fry’s/outpost.com sells: GQ Glossy Photo Paper #2687282. Fry’s often has this paper on sale for $.99 for 20 sheets. It does not require tedious scrubbing to remove (in fact, contact with water should be avoided entirely); just iron it thoroughly with a backing sheet, allow to cool, and peel off. I have had good results with such high-resolution applications as RF stripline and TSSOP pads.

    Double-sided boards can be made as well. I etch one side while protecting the other with contact paper, drill a couple of guide holes and transfer the second side, then etch again with the first side protected. Labor-intensive but it beats a board house for same-day results.

  27. tns says:

    ryan: how do you iron the toner onto the second side without screwing up the first? I’ve tried it many times with many different approaches, and I haven’t gotten it to work. I’ve tried gluing the paper to the first side and leaving it on while ironing side two on. I’ve tried the same method but with a cold, wet towel under the first side. I’ve tried ironing both at once using a cookie sheet, stove, and iron. I’ve never been able to make a two-sided-board because I always melt the toner off the first side while ironing on the second side.

  28. acceptable Risk says:

    xaph:

    I print my transfers from a cheap lexmark inkjet printer. Perhaps it’s the combination of the cheap glossy magazine paper I use that makes it work, I don’t know. It’s worked in the past for me.

    By wrap in a towel, I mean: After you scrub the board with steel wool/nylon scrubber, Line up your your pattern on the board and fold both in a damp towel then apply heat through the towel. Use high heat and press straight down for thirty or forty seconds to make sure it gets stuck (provided your board is smaller than the sole of your iron), then move the iron in slow spirals to ensure that every place is well heated. Better to heat it for a little too long than not long enough.

    The comments system removes all capital letters so my post lost the emphasis on “hot” when I said I didn’t need hot water. When done ironing just toss the whole board into a pan of water. Let it sit for a few minutes and carefully peel the paper away. Sometimes you need to rub a little with your fingers, but be careful not to rub off a trace. Usually if it doesn’t just slide right off, you should probably just let it soak a little longer.

    I’ve only ever used ferric chloride as an etchant, so I can’t advise otherwise. I also reuse my etchant many many times before I replace it. I’m not sure what you’re _supposed_ to do with it.

    When it’s done etching, just clean the board with some acetone or nail polish remover and drill.

    The results are pretty good. Easily distinguishable from a professionally printed board, but enough to get the job done for me. Ocassionally, I’ve needed to use a Sharpie marker or a correction pen to fix the smallest of traces, depending on whether I catch them before or after I etch. I’ve used them for moderately large surface mount work with no particular problems.

    I suppose I should also note that I’ve really only done single sided boards with this method. Though, I don’t know why it wouldn’t work for double sided.

  29. foobario says:

    #22: our local surplus shop sells copperclad scraps for $1/pound, regardless of size and number of copper sides. Most of my cost in making a board is in the photoetch chemicals.

  30. foobario says:

    #21:
    our Fred Meyer’s has had the Dremel drill press for $38.

    Harbor Freight has a small benchtop 5-speed drill press that goes on sale for $35-$40 a few times a year. It’s precise enough for this work and leaves your Dremel free for other carnage.

  31. n00bmaster says:

    have been doing this for years at my school. We use a t-shirt press instead of an iron. It works really good.

  32. A few things to note here.

    I had an old laser printer which wasnt working anymore, but the fuser unit still worked great on it. I took the entire printer apart and removed the fuser unit and now I use that for ironing my designs onto the copper clad board. It is only heated from one side, but I would imagine you could get both sides of the toner to transfer in one pass through the transfer unit (since it squishes it quite tightly as it goes through the unit!)

    #2, in the new year I will be getting a dremel drill press. In Canada, Canadian tire sells 2 versions (Dremel brand and a knockoff), for about $50 and $40 CAD respectively. I dont know if they ship internationally, but I think you can buy online at http://www.canadiantire.ca. Ebay has a bunch of them too.’

    Great comments here!

  33. xaph says:

    acceptable risk:
    Thanks for that! My next crazy idea will definitely involve an attempt at your technique :) If you maybe have a photo of results or any itermediate steps, I’d like to see them, but I think I have the jist of the idea.

  34. Chris says:

    I’ve used the methods detailed here before to various levels of success.

    The Staples paper he mentions does work well, it is very thick and leaves nice lines. Although if you are etching thin traces I find its less of a headache to get the board done by a pro.

    I’ve been using these guys: http://www.custompcb.com/

    They’re really fast at getting your board back to you, and the cost is much less than all the money I’ve put into ethcing fluid, heaters, paper, toner, trace pens, etc.

  35. Boreger says:

    Well, this technology remembers me, for the the press&peel T-shirt printing.

    If I making a PCB, usually i using two technology.

    First is the inking. It’s fast, effective for the small, dirty jobs, even the small digital circuits.
    Usually i cleans the cuted boards with the common household scouring powder. For the drying, is use a hairdryer.
    After that, I lays and scitch tape the printed, board layout to the PCB, and punch the center of the drilling holes, and the corners of the smd pads. If I use SO packages or 0603 size component I punch only the center of the pads. I use a light hammer, and a tapered 3 mm drill, for this job.
    When I done it, I grab my Staedler 0.5mm or 0.25mm technical pen and draws the layout. The ink could be anykind of unwashable, carmin red, ink. Never use black or different color. Somehow, the acid resistance not depend on the maker of the ink, it’s depends on the color. (Maybe some chemists knows the answer.)
    When the ink dryed, the PCB goes to the ferric acid bath.

    Second is the common photo-printing:
    I use this method for the small board series, and the difficult digital circuits.
    The cleaning process is same as the inking. After that I spray Positive20 or other photo sensitive paint to the cleaned boards, and dry them in dark, warm place. I print the layout to acril sheet with laser printer, or transparent technical paper by bubble-jet printer (not recommended for the fine lines). I fix the layout to the dryed boards and put under the UV light for 30 min.
    After that i soak the boards to the developer fluid (TN 140 for example) for 1 or 2 minutes. I wash the developed boards and etching in the ferric acid.

    Happy hacking!

  36. Angstrom says:

    I have recently made a few with the most simple method, and good for those without a laser printer: drawing etch resist directly onto the board. I suppose its not so great for making very complex boards.
    get a printout of the circuit tracks, sticky tape it to the copperclad. Get a fine nail and hammer, tap each drill hole marked on the schematic. peel off printout and draw connecting tracks in etch resist marker. Etch.

    it works for me & is really cheap & quick.

  37. rafael vuijk says:

    I tried toner-transfer once and the paper didn’t want to come off :(
    Also tried that special blue print ‘n peel sheet but it came useless out of the laserprinter all crumped up.
    The chemical garbage is much a bigger problem than the optic tranfer imho.

  38. Steve says:

    regarding the longevity of ferric chloride etchants: generally speaking, you can reuse the same liquid for as long as it remains a) effective b) its original color. saying it should remain the ‘original color’ is a simplistic way of saying that its useable as long as the solution isnt contaminated by the products of the etching reaction.

    note the particulate matter that precipitates out of solution. you should of course be applying mild heat and agitating the liquid during the etching. (check the bottle for the ideal temp, as it varies by concentration/pcb material/manufacturer). after the board has been removed from the bath, let the solution settle, and then decant the liquid that remains. the concentration usually increases slightly from evaporation, so a well used etchant sample will often do the job more quickly.

  39. justin says:

    Regarding #13 and #14.

    Another reason to do it yourself is the quickness. Sure getting 5 boards for 65 bux sounds ok, but are you willing to wait a week for them, and then maybe find out that you missed a pad or two? This way makes it easy to make a couple in one afternoon, and see any mistakes youve made over the way.

  40. kyle says:

    i totally agree, im so impatient that i often find myself browsing radioshack’s sorry ass selection because i dont want to wait a week to get my parts. i like this method because its fast.

  41. Gordonwong says:

    I spent many years trying various things:

    litho film, photoresist, toner transfer via label backing paper, ferric chloride, ammonium persulfate etc.

    Here’s what really works every time. It took took me 25 years to find this out:

    Print image reversed on plain paper with a laser printer. Iron candle wax into it to make it translucent. Expose onto a photoresist coated board. I use two UV flouresents in a twin-tube desk lamp at 4″ for 5 minutes under picture frame glass.

    Etch with 3/4 12% hydrogen peroxide (hairdressing supply) and 1/4 muriatic acid (hardware store). Keep it moving. And do it outside. The solution makes its own heat (no heaters, no sprayers or bubblers) and the etch is done in 3.2 minutes flat! You can SEE the progress unlike ferric chloride. Neutralize afterwards with baking soda.

    You could use drugstore 3% peroxide but it’s a six minute etch instead of three minutes.

    Cost: 1 litre 12% peroxide was $5, 1 litre muriatic acid was $4. Good for dozens of etches – make a new batch every time.

    If you do this quite often, better not to dump the resultant copper chloride into the environment. Save in a plastic bottle after neutralizing, label it and drop it to the hazdardous waste facility in your area.

  42. Rolan yang says:

    A solution of cupric chloride and muriatic acid can be used to etch boards. The best part about using this method is that bubbling air through the solution (and adding more water when necessary) regenerates its ablity to etch. No more pouring used etchant down the toilet!

    Search the web for articles on the chemical reaction.

    Here are some pics on my site:

    http://photo.omnistep.com/cucl2/

    ~Rolan

  43. Davy says:

    I use the Press n’ Peel transfer paper never tried inkjet paper. I hit on an idea the other day whilst orinting a CD on the Canon ip5000 — the ol’ marbles started ratlin’ what if I thought, if I replaced the CD with a PCB, when I get round to it I’ll give it a try.

    Ok, Ok we all don’t want a round PCB including me, just a slight alteration to the software, mechansim maybe and then we’ll worry about the ink standing up to a bath..

  44. mishgan says:
  45. luteragzfer says:

    Mike Mossberg, I know you reading this forum, please contact me, because I can’t find your contact details.

  46. Whenserce says:

    chi conosce msn discovery?Ho come antivirus Avast home versione 4.8.1292,credo di essermi registrato verso Settembre 2007,poi siccome ho dovuto riformattare il Pc 2 volte ho reinstallato sempre lo stesso Antivirus e sempre l’ho registrato con la stessa chiave di licenza.Ora mi domando ma la licenza vale 14 mesi da quando ne ho fatto richiesta la 1 volta oppure ogni volta che ho reinserito la chiave si ?? come dire rinnovato il periodo di validit??’? poi quando scade ti avvisano loro o devo richiedere io la nuova chiave di licenza? ‘C?? un modo per sapere la scadenza precisa della licenza oppure no? Perch?? se clicco sulla pallina di Avast e clicco sulla voce Riguardo avast mi dice solo Scadenza aggiornamenti lunedi 1 Dicembre 2008 0.00.00,grazie per l’aiuto.Ho provato anche a richiedere il numero della licenza,ma mi hanno spedito solo la chiave senza data di registrazione e scadenza.

    [img]http://www.chatt-gratis.net/javachat/immagini/content.gif[/img]

  47. james says:

    hey davy (above),

    Right idea, wrong kind of printer. Epson is the only consumer grade (possibly only) printer that uses an electro-static um uhh… here’s a web site.

  48. MelvinXH says:

    Hi just off subject . just wanna ask anyone know what is the best company provide good identity theft protection out there ?

  49. kookimebux says:

    Hello. And Bye. :)

  50. Similar post I found some other places . Here I want to talking about some bubbler. Some quality bubbler just placing my link with this

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