Making Excellent Printed Circuit Boards

Emil Andersson
October 21, 2007

Before I made Stefan’s BatmanII described here on his website I reserached hobby methods for printing circuit boards. I find some sites describing how to transfer the artwork with a laser printer/copy machine on paper to the board. I think that this http://www.fullnet.com/~tomg/gooteepc.htm write up is the best I came across. I used the Staple paper suggested and the transfer came out GREAT!

Emil

raymond borowiak
October 13, 2008

I remember using photo resist coated PCB’s. It was the best PCB’s I had ever made. I exposed the pcb in several places at several exposure rates to find the right one for the bulb I was using to expose with. Developed it then that told me the exposure time to use. It was a snap all I needed was a positive printed on mylar film out of the laser jet printer, I used a 250watt reflector bulb to heat the ferric chloride and a magnetic stirrer which just spins a plastic propeller in the solution. I never did plated thru holes. Photo resist pcb’s can be really professional looking.

Ersin Ayra
March 13, 2009

It gives very good result to apply in thinner solved resin on the copper side. It protects the oxidation and helps to better soldering.

Regards,

Joshua S
July 01, 2009

Instead of Ferric Chloride, which you have to dispose of once you use, you can use a solution of Muriatic acid and Hydrogen Peroxide. A detailed guide on this can be found on instructables (http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!–A-better-etc/) but the basic idea is 1 part Muriatic Acid, 2 parts Hydrogen Peroxide (Low concentration of Hydrogen Peroxide) and then you can use this indefinitely by bubbling in oxygen from the atmosphere (Use a cheap air pump from a fish store) Muriatic acid isn’t too hard to get, just find a pool store and they usually sell it, Hydrogen Peroxide can be found at most drug stores, and often even dollar stores.

mallikarjuna
December 31, 2009

I was read the theory but there was no detailed found, so please send brief details of the circuitary.

Cameron Lett
October 01, 2010

And here I was going to go buy a laser printer! Down to the stationary shop I go! Thanks alot for this page.

Michael Schwager
February 10, 2011

…Oh, just Google it to find Groove Juice. I believe it’s available at Guitar Center in the Chicago area. And there are other products like it. I imagine it’s some sort of weak acid.

Mickey Malone
May 24, 2011

Great article!

The Sharpie comment from a reader was just what I was looking for. MG Chemical advertises that their marker (Sharpie look-a-like) will not hold up to ammonium persulfate. I was looking for an alternative and this article confirms my suspicion that a real Sharpie will hold up just fine. Thanks!

joribo
June 09, 2013

…just a detail for the hobbyist. How to clean the PCB board so that the marker pen paint will stick. I tried acetone first but it was not optimum. Then I used my toothbrush and a rather agressive sort of toothpaste (once per week whitening), which they sell as DENIVIT here in Finland. Rinsing with hot tap water and final rinse with destilled water gave excellent results. I asked a chemist why the acetone left greasy stains and he replied that this might be an addition of certain substances to prevent sniffing it as a drug (causing bad feeling).

George T.
September 12, 2013

Ferric Chloride may be kinda hazardous and/or difficult to get a hold of so do like I did. You can mix Vinegar, Hydrogen Peroxide and Table salt to form a Copper etchant. Takes a little bit longer to etch than ferric chloride, but an extremely cheap and easy option…just use 1 part vinegar, 1 part peroxide and a lot of salt, more salt=stronger reaction. I also hear Muriatic Acid (found at local hardware store) works wonders and faster, but it’s a lot more acidic than vinegar so be EXTREMELY careful when using.

tzader
October 25, 2013

Clean your board with a nylon green scouring pad and Ajax (or equivalent)cleanser. Rinse in water. Tip board off horizontal and look for a “water break free surface” ie. looks like entire surface of board has a coating of liquid. The way a surface was prepared for epoxy bonding, or etching in the old aerospace days.

pradeep
July 08, 2015

thanks

Eric
May 09, 2016

After much trial and error of different methods, I get the best and most consistent results using a vinyl cutter/plotter to lay out the design on the PCB using either an ultra fine point or regular fine point Sharpie and then etching with muriatic acid/hydrogen peroxide. For best results with the ultra fine point Sharpie, I trace the design over itself three times. Then I let it set up for at least 5 or 6 hours before etching. I also find that it is helpful to use a little less than the recommended 1 part acid to two parts HP. This of course slightly slows the etch but it still goes pretty fast regardless. I also keep my etching container in a larger container of hot water to keep the solution warm, and I use an aquarium pump with a bubble wand to aerate the etching solution. I also attach a couple of pieces of styrofoam to the back surface of the PCB with electrical tape or even elastics to keep it floating face down in the solution. The action of the bubbles seems to scrub the surface gently without abrading it at all; a typical 2″ by 6″ card will easily etch in two or three minutes, and I find that I can usually do up to four PCBs in succession before the solution significantly slows. From what I have read about this method, it appears that the additional oxygen provided by the aeration helps a lot. If I have still more PCBs to do, I add a small amount of acid after the fourth PCB. I do not store the spent etchant; as I only do PCB making on occasion and I usually try to plan to have several to do in one etching session. Anyhow, I find this to be the most consistently repeatable method that gives very good results with traces down to one mm. Previously I tried ironing photo paper with the circuit printed on a laser printer, but the results were very inconsistent and it was very difficult to get small traces. I would always have to go back over it numerous times with a Sharpie anyhow, not to mention dirtying my wife’s clothes iron.

Vinyl cutters are used by sign makers, and there are many different models available for under $300.00. You can use a number of different CAD programs to make your circuit design and the particular vinyl cutter I use requires the final design to be in the PNG format. So far, I have not found an easier or better way. Results are consistent, very good, finely detailed and actually kind of fun to do as well. Perhaps the most important thing is tracing the ultra fine point Sharpie three times and then giving it 5 to 6 hours to set up, and likewise a little less acid, probably more like 7:2 for peroxide and muriatic rather than 2:1. One thing I did find, however is that the new “green” muriatic that fumes less and doesn’t smell as strongly seems to have ingredients that will degrade the Sharpie ink a lot faster. The standard type is definitely preferable.

Needless to say, keep safety always in mind; take your time, plan each step carefully, wear goggles, chemical resistant gloves, do it outdoors, don’t breathe the fumes and be ever mindful that this activity does involve dangerous chemicals. Keep kids and pets away!

The muriatic/peroxide mix will degrade Sharpie ink in time; the thing to keep in mind is that if this is going well, the etch will be completed well before the Sharpie ink has degraded enough to fail. I did try the vinegar/peroxide/salt method also, but by the time the copper has etched, most of the Sharpie ink will have degraded as well, so in my opinion, that method is not satisfactory. Perhaps with a different resist it can work, but if you are using a standard Sharpie, it is too slow to be beneficial. If I were doing this frequently, I’d send my designs off to a PCB fabber, but I only do this a few times a year and thus the above method is perfectly satisfactory for my needs.

sfinktah
January 02, 2020

When using peroxide and acid, chlorine gas is released when the ratio of peroxide exceeds that of the muriatic acid.

Add the peroxide to the acid, not the other way around, and aim to have slightly less peroxide.

I use 6% peroxide instead of the usual 3%, so the recipe is equal parts peroxide and acid. No need to measure, just ensure the volume of the peroxide is of the same (slightly less) volume.

And rinse the measuring container, else residue of acid + peroxide will convert the acid residue directly into chlorine gas.

I used to etch indoors, but gave it up because the acid smell spreads.

I have also used Uni-Ball Signo pens (white) as a resist pen. They come in sub-mm sizes, though they seem to wash off eventually (though I have had them work perfect). Sometimes I draw with a sharpie then go over it with a white Signo to give it a bit more protection.

It’s also useful for writing or masking after you’ve etched.

If you have on of the rare Epson printers that can print on PVC card (like Visa cards and such), you. can buy a tray for the purpose. Either print PCBs the size of cards, or you could sand down the divide (the carrier holds two cards) to make a far bigger area. Epson Artisan 1430 (A3) and Epson Stylus Photo T50 are two that I can confirm work for printing on custom card carriers and are compatible with the modified drivers requires. You can get the carriers on amazon or whatever.

Notes: I’ve never tried using them for PCB work, but I have confirmed that the thin PCBs appear to be the same height as PVC cards.