Part 2: Printing Glass Circuit Boards

Part 1: • Part 1: How I work wit...
Part 3: • Part 3: Getting glass ...
Here I am showing how I actually make my glass circuit boards. The process is very similar to making regular circuit boards, but there is some extra care taken in a few steps. I will add links and notes here as people comment on the video.
If you like videos like this feel free to support me on patreon: / cnlohr

[@DougWoodrow]

That warning at 10:15 is so right! I wish you were around when I was young and making crude circuit boards by drawing freehand with an etch resist pen on copper-clad boards. I remember those yellow ferric chloride balls vividly; I was lucky enough to have a washbasin in my bedroom and it was all going so well until the u-bend under the washbasin dissolved...

[@CNLohr]

That sounds horrifying

[@zachwiej89]

A pro-tip for tok - use a piece of regular scotch tape to peal the protective layer from dry film photoresist :)

[@CNLohr]

THAT IS A REALLY GOOD IDEA

[@SemlerPDX]

Grow Lights are specifically designed to emit very little in the UV spectrum, focusing more on the 3500-7000 Kelvin ranges, and this is because ultraviolet light is quite harmful to most all living things but particularly plants. Either your light was not a grow light, or it was in the 12,000-20,000 Kelvin range and was mislabeled as a grow light. Either way, it looks like you used a high intensity discharge lamp, but if UV light is required for that process, you should say so. Nice concept, too!

[@JehVolta12]

I don't mean to be nosy but, do you do this for a living or is it just for fun? I don't mean to be rude but to be honest, your YT channel is one of the most amazing channels I have ever seen. Greetings from Mexico City!

[@CNLohr]

I make youtube videos just for fun, all my vids are about my hobby. I do have a day job.

[@urdnal]

I've read some people have had success printing directly onto aluminum foil with laser printers. In that case, you could probably laser print right onto the copper foil and etch that, skipping a few steps. Might make gluing to the glass more challenging, since it'd be after the print.

[@CNLohr]

I have tried the direct-to-copper stuff, but it came out just awfully at least with the laser printer I tested with. Perhaps if I could have found a way to make it go much much slower it would have worked. It just couldn't get to fusing temperatures with the thick 1.4mil stuff I was using.

[@urdnal]

Ah ok. Dang, it'd be an easy process if it worked

[@youigta]

Do you have some details about aluminium foil circuit boards cause i really wanna attempt that

[@urdnal]

I actually can't find it now, but I don't think it was for a circuit. I know that I came about it researching printing directly on pyralux and it might've been on hackaday, or linked from hackaday. If I find it again in the future, I'll post a link here.

[@Megabobster]

Born in '96 and representing :) although I did grow up with MS-DOS/Win3.1/95/98 despite them being thoroughly outdated

[@CNLohr]

That is rather sad. Man. DOS and BASIC stunted my growth so bad. C. C is where it is at. I wish I had C earlier.

[@Megabobster]

CNLohr Meh, I didn't really get into programming until recently. I was always in it for the games lol

[@CNLohr]

aah, gotcha. I don't know, programming has always been magic to me.

[@shodanxx]

have you tried muriatic acid/hydrochloric acid with 30% hydrogen peroxide ? Like less than 10$ for a gallon and less of an hazmat problem. I tried it, worked great and very fast but it will make everything around it rust if you leave it in an open container for a few weeks.

[@CNLohr]

Stuff is SO FOUL. Can't use it anywhere near the house. Ferric Chloride offgasses very little while working.

[@macgyver5108]

I wonder... instead of the Loctite, trying clear nail polish? For starters it's WAY cheaper but even better yet it's _really_ heat resistant. I've been using that on my rifles for eons now as a thread locker instead of Loctite because it holds _SO_ much better on parts that get really hot so I bet it might work as good or better?! Comes off with Acetone too though if you soak it long enough.

[@CNLohr]

Depends, are there nail polishes that can cure entirely with UV without access to air?

[@macgyver5108]

@@CNLohr well, when used as thread locker it dries no problem even in the microcasim of a gap between the finest of small screw threads and pretty much all the air gap in the threads is displaced with the polish, so the solvent that keeps it liquid still manages to evaporate out of such a small area. I suppose if you wanted to speed up the cure time you could use a hair dryer, heat gun or put it in front of a heat vent too.

[@onderdincel]

have you ever tried copper tape and attached directly on the glass? by the way why didnt you directly transfer the design on the copper with an iron?

[@CNLohr]

I have but the adhesive on the back of copper tape makes it not nearly as tough as UV glass glue

[@akkudakkupl]

Why glass PCB's? Just the looks?

[@CNLohr]

yep!

[@BurkenProductions]

Why not??

[@thierrygenon7444]

At the price of LOCTITE 3301 and other similar adhesives, I don't see much point in this method. There are neoprene based adhesives for hot press bonding that give identical results but for much less money! At the price of these adhesives, if you make a lot of PCBs, use the CNC engraving method!

[@CNLohr]

How in the world would you use CNC engraving on glass?

[@tsusec]

FeCl is too slow, thats why i dont use it. H2O2(35%) + HCl + H2O mixed in ratio 1:3:5 works the best for me.

[@BurkenProductions]

seems like a hassle with that gel, why not just spray with positive photoresist like one usually does? seems easier.

[@netdudeuk]

Thanks for the video. Why not just use normal copper clad board though ?

[@CNLohr]

Glass PCBs are pretty :-D

[@GalgoczkiAdam]

Nice video! Have you ever try to put the copper foil into the printer, before the gluing?

[@CNLohr]

No. What would that accomplish?

[@GalgoczkiAdam]

​@@CNLohr You know, like the tone transfer method. Print the negative to photo paper with laser printer, then put it on the pcb and transfer the ink with hot iron. So if you could print the layout directly onto the copper that would be super easy and fast.

[@Tedlasman]

Have you ever tried using sodium silicate (water glass) as the adhesive?

[@CNLohr]

No, in fact I've never even heard of that. Googling it I really don't have a clear idea if it would work well or not. I'm sadly not a chemist and really focus more on the firmware/software side of things.

[@Tedlasman]

@@CNLohr you have any of the glue left over?

[@CNLohr]

@@Tedlasman Maybe but it's almost certainly all bad by now. You could try reaching out and seeing if you can get any www.etch-o-matic.com/price_sheets/uv_bonding_unit.php

[@Tedlasman]

@@CNLohr Thank you!

[@Mr_ToR]

awesome thnx a lot

[@isfiyiywafibc6qaiiiiiiiiii570]

I have a quick question: I looked up the pantum and it does sound great but like all cheap printers it seems to have silly expensive replacement toner cartridges (PA-210 from what I can tell). Do you buy these somewhere for cheap or do you refill them yourself, or are they actually worth £55 ($57.1 without UK VAT)

[@CNLohr]

That sounds about right.

[@isfiyiywafibc6qaiiiiiiiiii570]

CNLohr So do you buy them or refill them? (It looks like you didn't click "Read More" on the comment :P)

[@1sonyzz]

Had exactly same printer which after 2 months of use died on me, power supply board just smoked :( was really nice printer tho, had mirroring function in printer settings, i still have it cant figure out what happened because no exploded parts or fuses, board like new

[@CNLohr]

Mine is still going strong!

[@1sonyzz]

CNLohr made me jelous now, i bought it on sale was 20gbp or 25 us dollars, original price was 45gbp or about 50-55 us dollars, and thanks for the tutorials :)

[@alzathoth]

could this process work on acrylic sheet instead of glass?

[@UpcycleElectronics]

alzathoth I doubt it. First, acrylic probably can't handle the heat from the laminator without deforming. Secondly, the acrylic surface will create all kinds of problems because of the different thermal properties of the plastic and copper. Basically the adhesive must be able to stick while getting pulled in multiple directions at once in a microscopic scale. The types of adhesive (I am aware of) that can accomplish this kind of flexibility are generally more chemically reactive and won't handle this kind of process. It might be possible but it would be a big project to figure out. Just wire your project point to point with solid core wire and embed the whole thing in clear casting resin ;)

[@shubhamadtp]

Which software is used in the video for making the board and export

[@CNLohr]

I use Gimp for taking the .ps files and exporting as .png

[@farbenformenlicht]

Did you try some other adhesives beside UV-ones? Could it work with glass clear epoxy?

[@CNLohr]

I tried epoxies but never got them to work well. You could totally try!

[@farbenformenlicht]

which problems did you have? Did the copper come off? I try to get the materials here in germany, but it isn´t easy to find the right stuff...

[@CNLohr]

I couldn't get the epoxy coplanar. Like it was really lumpy :(

[@feynthefallen]

Don't use steel wool. Use mineral wool. You're leaving miniscule amounts of steel or there, creating an electric element, which will corrode the copper eventually.

[@CNLohr]

There's a lot more ferrous material in the ferric chloride, but that's why we acetone the boards when done.

[@lamle4364]

how to buy copper plate?

[@CNLohr]

eBay or nimrod-hall copper

[@dominikehlen2418]

What kind of tape are you using to fix the circuit layout on the copper?

[@CNLohr]

I usually don't tape it down. I just squeegy out the oil and the transparency just stays put.

[@dominikehlen2418]

I mean the double-sided tape(?) at 4:00 . Is it any special tape? My boards was done by an manufacturer before so I don't know the procedure for usual homemade boards like you said there :/ And google just showed up other methodes without any kind of such an "Tape to plastic when exposed to UV" thing.

[@CNLohr]

That is not tape? It's Riston.

[@dominikehlen2418]

Ahhhhh okay. Now i got it. Thank you! :)

[@NurchOK]

Actually, Na2CO3 is sodium bicarbonate, the baking soda is sodium hydrocarbonate (NaHCO3) [or sodium hydrogen carbonate]

[@CNLohr]

You are right about the chemical composition, but, it is odd the english name really is "Sodium Bicarbonate." Until today, I was unaware the IUPAC name was really sodium hydrogen carbonate

[@NurchOK]

I don't think that problem is only in English. In Russian, for instance, baking soda is also called Sodium Bicarbonate (натрий двууглекислый, бикарбонат натрия) and also Sodium Hydrocarbonate (гидрокарбонат натрия) interchangeably. The actual Na2CO3 is called calceinated soda (кальцинированная сода) although, there is no Calcium in it. I think this is due to historical reasons, perhaps before people knew the difference, both behaved similar when performing some task (most likely cleaning), so both were called the same. Then as science developed, peeps realised that these have different compositions and that one is safe to ingest and the other - no so much :). But the names stuck... That was just MHO.

[@leocurious9919]

NaHCO3 is sodium bicarbonate (=baking soda) In any language where it sound even remotely like that. Na2CO3 is sodium carbonate.

[@CNLohr]

I've switched to washing soda now, anyway :-p. Just has to be hot water when you use it!

[@NurchOK]

Then what does "bi-" mean??? In my understanding bi-something is two-something. Proper chemical name is sodium hydrocarbonate, IUPAC recommended name is sodium hydrogen carbonate; however, the historical name is sodium bicarbonate. Bicarbonate formula is HCO3- (sub 3, super -), but IUPAC recommended nomenclature is hydrogen carbonate. Sorry to disappoint you :)

[@mogiet]

Hi, what software did you use to draw the board :-D

[@CNLohr]

I believe I used KiCad for this, if not, it would have been ExpressPCB, but I strongly recommend KiCad now.

[@victortitov1740]

@@CNLohr your board looks almost as if you've designed it with help from TopoR.

[@afonsusmuralha]

what is the thickness of the copper sheet?

[@CNLohr]

typically 1 or 1.4 mil

[@afonsusmuralha]

CNLohr thanks, I'm really curious about this technique and I would really like to try it :) btw is that loctite the best glue for the job, I'm having a hard time finding it at a reasonable price... you know any alternatives/equivalents that might work?

[@CNLohr]

martronics uv glass glue is really good too, just a little tricky in the last two steps.

[@MrTiger-jt4xm]

How i get uv sorce

[@CNLohr]

UV Bulb or you can use a UV LED.

[@krishna34674]

ever tried heated sodium persulphate ?

[@CNLohr]

Nope. At this point, I am pretty set, but if you have any videos that make it shine over ferric chloride, I would certainly watch and reconsider.

[@mrlazda]

For home use "best" solution is using ammonium peroxydisulfate, is a clean and "safe" method. Chemical reaction of ammonium peroxydisulfate and copper creates dissolved copper sulfate from which you can extract copper by electrolysis, or use it as herbicide if you have grapes plantation (bluestone). Only downside of it is that process is slow at room temperature (it speed up if you heat it to 35-45 degrees Celcius, but even then is slow comparing to let say HCL and H2O2).

[@CNLohr]

Sadly, speed is everything for me.

[@mrlazda]

CNLohr Then for you is HCL and H2O2, it is 3-5 times faster than ferric chloride, but you use "dangerous" chemicals, and it is "reusable" (that industry say, I never managed to use it multiple times, it have extremely short shelf life but considering how cheap it is that hardly matters).

[@CNLohr]

*sigh* sooner or later. I do have the ingredients.

[@brainndamage]

How do you like kicad?

[@CNLohr]

quite well! It just steadily gets better.

[@matthewavilez318]

7:24 dab

[@AlexkWright]

That pitch.

[@CNLohr]

pitch?

[@AlexkWright]

The center to center spacing. I know it wouldn't considered particularly detailed if this was a professional board fab.. but copper sheet hand squeegeed to a glass slide with Locktight, and exposed with a transparency printed on a ~$50 laser printer. That's some impressive detail.

[@CNLohr]

Ah! Yes. Every time I've been able to make a jump to the next smaller pitch I had a lot of excitement! It is a ton of fun!

[@CNLohr]

Can you take a high fidelity picture of your transparency held up to a blue or cloud-covered sky? But! But! I must say. I have tried SEVERAL pre-coated boards and ALWAYS had trouble. Riston is SO forgiving.

[@CNLohr]

Brand name. I didn't know there was generic.

[@SinanAkkoyun]

Good thing glass does not absorb UV light...

[@CNLohr]

you are right. Later on I ended up using a UV LED. Exposure happened in about six seconds!!!

[@genkidama7385]

i dont see any good reason to do this unless impressing people with transparent circuitry.

[@CNLohr]

It just looks so cool

[@txm100]

Why print a .png out of an office program? There are so much better workflows.

[@CNLohr]

export to PNG, drop PNG into office program. Print from office program.

[@txm100]

Yeah. But you have beautiful crisp vectors and then you are printing from a raster image.

[@BHBalast]

Why not, if dpi is enought.

[@CNLohr]

Well, #1: Printer's only 1200 dpi. #2: How would you organize your designs on something to print with page guides? I've tried inkscape and it's just not geared for it.

[@tohopes]

when I want to layout things geometrically for printing, I spin up a little html page with some css.

[@ACTlVISION]

jfc that loctite costs $80 lol

[@CNLohr]

You can also use Martronics UV Glass Glue

[@tusmoommegaaga2791]

kkkkkkk okay

[@lepketheslime4792]

me barley knows how to think, guy there making circuit boards at home :O

[@BurkenProductions]

what?? even regular is just as easy

[@HazeAnderson]

Vector format not useful 😂

[@mistermodding]

DON'T WASTE WATER! PLEASE... THANK YOU

[@CNLohr]

I live in Maryland. Water comes freely from the sky, in rivers and out of the ground. We literally have more fresh water than we know what to do with, year-round. Perhaps you should move here.

[@mistermodding]

When they were filled, he said unto his disciples, Gather up the fragments that remain, that nothing be lost (John 6:12)

[@wpenrose]

They were making PCBs in the Bible?

[@wpenrose]

Don't come to Arizona. We buy our water from boutique shops in little one ounce bottles in velvet lined boxes.