Step 3: Iron it on

Picture of Iron it on
With the two paper sheets taped together, turn on your iron to the highest setting. Also make sure there is no water in it if you have a steam type iron. Now, take your sheet of copper board and slide it carefully between the two sheets. See pic below. Position the copper clad board as desired, and once the iron is hot, place the iron on the paper and press hard. It takes some practice to get the hang of ironing on the toner, but just press hard and wiggle the iron over the whole board while taking care not to move the paper relative to the board. Once one side is ironed to your satisfaction, then carefully flip the whole thing over and iron the bottom layer. One thing to remember is to clean the board carefully with a cotton ball or old sock soaked in isopropanol (rubbing alcohol) before ironing to remove any finger prints or grease.

Once you are done ironing, cut the paper around the board if desired, and drop the paper and board into a container of water to soak the paper. Let this soak for about 10 minutes. With the cheap glossy laser paper from Kinko's the time is much shorter than the high quality inkjet photo paper. Once the paper is soaked, peel the paper off both sides. This should leave the toner and a thin layer of the paper along with the glossy stuff on the copper board. Using your thumbs or an old toothbrush, carefully rub off the extra paper pulp and junk on the board. See pic, below showing a board with half of the pulp rubbed off.

Once the paper pulp is rubbed off, carefully inspect the traces and features on the board for small imperfections and stuff that will cause problems later. Key areas to pay attention to are closely spaced traces and pads where it is easy for paper or glossy coating to bridge and keep the copper from etching. Also, you can achieve very fine pads for doing TSSOP, QFP, and other fine pitch packages using the toner method if you carefully scrape between pads using an Xacto knife or similar prior to etching. During ironing, the toner tends to smear slightly, so very fine pitch pads tend to mush together. Using the knife, you can scrape between the pads or traces to make sure the copper will etch between. If you are careful, there is no reason you can't get 800 micron or even 500 micron pitch pads.
lee3219872 years ago
Just a tip...
I have successfully used an ultra fine point Sharpie to draw traces that were scrubbed off or didn't stick.
I don't recall, but i may have applied more than one layer of sharpie ink.
(my etchant was was muriatic acid)
See the images.
You can get good result easy.
Just use FAIRY (dishes cleaner) and a kitchen sponge with a abrazive green part
to clean well the copper board. after that just dry well with paper towels and
put your pice of paper from the printer. use the iron, mine is PHILIPS AZURE 2400W(cheap one, normal one).Press with iron for 5 to 10 minutes(moving and pressing), after that pull the paper, soak in water for 10 min or so.
start rubbing with your finger and with toothbrush until traces clean withouth paper.
then use feric cloride to etch.
that's it.
sory my bad english.
want to know more just send private message.
or also leave here a message.
I made a board for STM32F103C8T6 ARM CORTEX-M3
48 pins, TQFP.
Just post comment if you want to know what paper and iron to use.
I get good boards like this in half hour.

Just check the fingerprint for that microcontroler, to see how small shoult be.
Always get good result.
I can't let the mail here because I will receive a lot spam in it.
So just leave message here.
I don't need money or anything!
See the photos for what I use.
The iron is PHILIPS AZURE 2400 WATT( normal one).

also get the board for the STM(NOT THE ONE I USE, AN OLD DESIGN ONE BUT GOOD), just for testing.
OK. Now you have it all!

but the most important is cleaning the surface of the board.
with FAIRY(yes dishes cleaning for kitchen and a sponge with a green abrasive face. use the green abrasive face)
I use the Paint from windows to draw!

OK. if some of you think I should put a tutorial just send me messages.
rayshobby3 years ago
Consider using a laminator instead of a hot iron. I've used hot iron before and it's a pain. As soon as I tried laminator, I never want to use a hot iron again. For example, a GBC pouch laminator from amazon works just fine.
jmengel (author)  rayshobby3 years ago
Good tip. Thanks.
You know, I did a few of these PCB boards, one or two sided, and I was never happy when compared with the “professional” ones. The latest one I’ve tried to do (better) was using the “hot iron” technique. So, I had this glossy paper (I’ve even used those transparent plastic sheets made special for this purpose), I’ve printed my design on and, with a hot iron (as recommended) I pressed.
Well, if not hold enough, the ink will not melt and nothing will be achieved. If hold too long, then the ink melts but the strait, clean lines become smudged. And as each board is different in size and number of lines, it is almost impossible to extrapolate a “good” timing for all the other ones. And you cannot experiment with 20 for only one.
Any suggestion?
jmengel (author)  dan mihalciuc4 years ago
Certainly these methods do not match professionally made boards. They are useful for one-off type quick and dirty boards though. If you need more than one, and want them to look good, I would suggest using the bare-bones service at www.4pcb.com. It is cheap and quick, and will get you a double sided PCB with tin plating, no silkscreen, no solder mask. Works great for me, both on the hotplate and hand soldered.

shimniok5 years ago
Thanks for the fantastic instructable!!  I guess ironing correctly is the real trick... I have the hardest time figuring out when to stop ironing. Too much and the traces and pads smudge.  I can't seem to get the resolution you are getting... :(  I can do through hole, but until I get the ironing figured out SMT is a lost cause. :(  Any tips welcome.  Meanwhile, being able to do 2-sided would be awesome.
jmengel (author)  shimniok5 years ago
Fine pitch SMT can be a challenge.  The key is to clean the board well, using a scotchbrite and some solvent or similar.  Getting good iron pressure without smearing is also important.  I find that using the smooth "magazine" type paper is critical for fine pitch SMT while regular printer paper is adequate for through-hole.  Even so, when scrubbing off the paper, you need to be careful not to scrub too hard.  Leaving some of the smooth paper residue behind is OK on the bigger features, and on the fine SMT pads and traces I will scrape between the pads with an X-acto knife to ensure that they will not short after the etch.  This can be a pain if you have a lot of high pin count SMT ICs, but if that is the case you should be using a commercial solution like "4PCB.com".  Their bare-bones 2-sided board service works great and is pretty cheap.

For toner two-sided, the key is to have the paper sheets larger than the PCB and to tape them together in alignment outside the edge of the PCB so that the iron doesn't have any bumps to go over or will melt the tape.  Holding the two sheets up to a window will allow you to align them, but don't expect super tight tolerances for your vias.  I'd say make your vias pretty big (at least 1mm) since you will have to drill them yourself and small via pads tear off the board pretty easily during drilling.  Also, be sure and DO NOT fill the vias in Eagle or similar since the drill bit will skitter off the copper via or pad when drilling if there isn't a center mark from the etch process.
Good luck.