Dry-film photoresist is the solution you need. It comes in thin blue film that you can iron on copper-cladded board (not the solder mask paste). The exposed photoresist turns darker and hardens while unexposed part dissolves in alkaline solution (sodium carbonate). It's much cheaper than presensitized UV PCB, and can be removed & reapplied if something goes wrong during exposure.

I imagine that for prototyping and small scale fabrication, this is kind of a game changer.

OMFG.... I've been looking for a way to do this for months and the solution was in front of my face, on my desk this whole time! Thank you so much for this!!!!!!

This takes me back 50 years when I was a teenager making pcbs in the bathroom by exposing boards with a sun tanning lamp. In hindsight I had lots of failures mostly because I was spraying the Kodak liquid resist. The resulting coating thickness was not uniform enough requiring different exposure times across the board, basically clean off the resist and try again. As I recall the Kodak literature recommended spinning the board to produce a uniform film thickness. The copper surface also needed to be insanely clean before attempting resist coating. If the resin printer UV light source is columnated consider spin coating before placing the coated board on the printer. This way the flatness of the board will not be a factor. Cheers-Peter

First saw this method on Huygens Optics channel and was shocked that this wasn't more common! Such a clever use of MSLA printers!

This is so underrated. Compared to any other DIY process, this is clean and relatively easy. Just WOW!

Such a simple concept with awesome results! Most of these machines are capable of displaying their logos during LCD testing so I wonder how you could just get images into it like that vs having to make a negative STL. Would greatly speed up the process, but unlikely to see with chitubox systems :(

I saw the thumbnail and the title and it hit me... that is brilliant. I always used toner transfer method which isn't very precise and no matter how often you do it, always remains a hit or miss.

This is a great idea! I've done many PCBs with the toner transfer method, but it does struggle a bit on smaller features. One suggestion - when using a small etch batch, you get a faster and better etch by removing less copper. Just use flood fills on most/all of the board. You can also make your fill a ground plane, which can help simplify routing and improve signal integrity or thermal performance in some cases as well.

I strongly recommend using ground planes on your PCB designs. It's way easier to design a board with a ground plane. It also means you remove less copper, which in turn makes the chemical last longer.

What a nice accomplishment! Thank you for the tip, now the resin 3D printer sales will increase ❤️

That result is actually pretty nice. I've been doing prototype PCBs for our company for a long time, but we cleaned out that pcb-prototype-lab a few years ago. It just was no longer really useful compared to a professionally made PCB with plated vias/holes, multilayer, solder mask, micro detail, reliability and quality, surface finish (ENIG) and all the other benefits. Waiting a week for a pcb is really not an issue, if you plan your project accordingly, and doing proper simulation and reviews of a design to have fewer errors or failures is worth more than trying to crank out 3 hardware-iterations in a week before you get a working design. I guess this technique here is still useful for some, and probably quite cost effective when you compare it to getting a good resolution 2D printer that can print highly opaque films and an UV lamp for pcb exposure with a vacuum pump.

I feel like I've just unlocked a new skill! Very smart idea. A lot easier than printing on acetate and using a UV lamp!

I've been wanting something to cheaply prototype boards for a while. Very cool!

Omg this is brilliant!!! So happy someone tried this and that it actually worked

3D print a drill guide as well so the holes will go easier. Great video!

I literally thought about doing this yesterday, what is life

I was going to go through the process of ordering PCB's for a thing at work that I wanted to play with, but this is much more in line with trying stuff out, perfectly timed video!

I never saw the need for a resin printer personally, but this is awesome

Many thanks for this. As an old hat at doing the stencil PCB Maker style boards it's refreshing to find a new way that removes some of the steps

Did this half a year ago, it's so easy and quick. also works for etching logos on different other metals or even mobile phone back covers

In the past, when I was still dealing with single-sided PCBs, this would have been a great technique. I then used sheets of overhead paper and a good laser printer to make transparencies and lay them over my PCB boards so that I could expose them. Meanwhile, with the current CPUs that we use, even double-sided PCBs are often not good enough anymore, and I use multilayer PCBs. For this, you cannot go with hobby equipment (unfortunately) and you have to go to PCB factories that can usually make a PCB within 2 days. But for anyone who needs a single-sided print, this is a great solution. Thank you for showing.

Thanks for this! I had the same idea, but had no idea what exposure time should be. I'll still do some tests to dial in the perfect time for my specific printer and film, but this gave me a much-needed point of reference to start from!

Thanks for this! this is really brilliant, another way to help when drilling the holes is creating a jig using the negative plate as a guide

I would love to see a follow-up video where you used a jig or fixture to align the PCB as well as made a 2 sided board.

I've seen this done before, but I can see someone making a device that would be two LCDs that would sandwich the board to make 2 layer boards easy to make.

This brings back memories of university and using a Lazer printer and trasparencies for making masks and a UV tube with a glass bed to expose them. I remember fixing mistakes with a black marker on the transparency or a sharp knife to scratch off the printing. This is a cool method.

I made my firsts PCBs 30 years ago drawing them with a sharpee whishing for something better. The time have come. This video is a great out the the box idea that will keep me thinking for some time. GREAT, GREAT, GREAT!!!!

This may be the coolest and most practical UKposts video I have ever seen.

This is one of those "why didn't I think of that" revelations. Great job!

Beautiful and simple. Looking forward to trying this myself at some point.

Wow! Never think about this way of use lcd printer. Thank you, this is very useful!

Oh man, that's a great implementation of a resin printer. I wish I'd thought of that for one of my clients.

That's brilliant. Seems to provide nicer results than other transfer methods. Happy holidays, Thomas

This is a nice idea. I use positive 20 because it's cheaper than than pre-coated boards (just needs a bit of spray-painting skill). To make big boards you would need a big resin printer, though. But it's real quick. I currently start with a PDF of my tracks that I have printed on tracing paper. Then I sandwich the paper between the coated PCB and a thick piece of perspex. That goes in the sun (after a couple of test exposures to get the time right as sunlight is always changing). I get pretty good results. Suitable for prototyping.

I love your ideas Tom. That why I started to watch your channel way way back long time ago.

FINALLY! I told people 2 years ago to use their resin printer with photoresist film. Great demo! I've made small silkscreen masks this way too! You can make the circuitboard and some artwork for the enclosure onthe same machine. That in itself is a boon for any small maker/tinker. I've been expecting someone to put a Chitu board in a flatbed scanner body tbh.

I'm glad that somebody did this! I think that is one of the best methods to do pcb etching. I'd like to build a device that does the same thing, without the 3d printer stuff.

Today is one of the days that I thought, thank God that I subbed to your channel! This is just brilliant!!

Aw man, that little wheelchair figure is awesome! As a chair user myself I geeked out a little.. Wish I had a 3D printer to try this out with. Awesome video!

Interesting technique. Last time I etched a board at home, I used the toner transfer method and etched in a muratic acid/hydrogen peroxide solution. It worked pretty well. Used the same solution to etch some brass sheets to make custom playing cards for a steampunk Gambit cosplay too.

One tip on sodium hydroxide: I would generally suggest sourcing food-grade sodium hydroxide/lye rather than lab grade sodium hydroxide. Food-grade NaOH is pelletized to minimize dust, because breathing in NaOH is very bad (people can debate the need and efficacy of respirators for acrylate fumes, but no one debates that breathing in lye dust is bad). The larger granule pellets make it relatively safe to handle for kitchen uses, like making pretzels because the bigger pellet size makes it much harder to dissolve if you accidentally touch it (lye isn't caustic until it is mixed with water) and has minimal caustic dust if you handle it gently. Lab-grade NaOH might come in a different granule sizes which might not be apparent on the labelling and may be potentially more hazardous to handle, especially with respect to eye and breathing protection. The NaOH shown in the video has large grains like food-grade NaOH. No need to be super scared of this stuff, as it is commonly used in cooking for things like pretzels or noodles. Just exercise some caution.

Brilliant Thomas. I have the Mars 2 Pro, and an older i3 Wanhao clone that I also setup with multiple toolheads (FDM, CNC Drill to 1.5mm, CNC Engrave - sharpened 8mm stainless rod drag style). I have a bag of single sided 0.8mm PCB blanks. Was going to try a simple project like making a multi-layered Arduino or something to prove the 3D printers can do multilayer PCB's. I think the key will be layer alignment, and this can be done with first using the dremel and those small drill bits like 0.6mm. FlatCAM was made for making PCB's, has many options like drill depths for CNC drilling gcode a 3D printer with Marlin can understand.

Had an idea about doing this with my original Anycubic resin printer some years back and never quite got round to testing it. Thanks for putting the hard work in, and getting this out there :) Its evidently way easier & more reliable than the pain of Toner transfer from laser printed gloss paper ;)

I'm thrilled to see this! Thank you for this Thomas!

I'm still fiddling about in FDM land but I've been wondering about this ever since a few friends got the Mars 1 & none of them have been willing to try it yet. Nice to know it actually does work! I figured there'd be no real reason why it wouldn't.

I have no need for making PCBs but I did found it interesting. It's great to find other uses for stuff you already have.

You could use photoresist film and apply it to the plane copper. Would be a great way for model makers to make brass etching for models or dioramas.

Brilliant in it's simplicity - got to give it a go and make some etched metal parts for my models...

This is absolutely phenomenal.

That is a quite genius method. Getting good quality films is always a bit of a hassle, even when using a laser printer. Think I finally found an excuse to buy a resin printer.

We need a series please!!!

This is so cool! I haven't made any PCBs before as it seemed to me like making the masks and the chemical process seemed quite complicated, but this method with pre-coated photoresist boards looks like a really great way to do it; I'm looking forward to trying it out! Thanks for sharing this Tom! 💜💙

What a great video. I love your experiments

Thank you for this very great idea. Why didn’t I think of this before, it is so obvious

this was a genius idea. I love it. Thanks. This plus a small CNC mill and you could make some great detailed DIY pcbs.

Nice! Very promising. So much better than what I had to do in high school in the 80's.

For smt prototyping of single sided boards that looks good👍🏻 And great to have a multipurpose machine!

Always add "copper pour" to your boards that you are making with this method because it dramatically reduces the amount of copper needed to remove during etching (and with it the amount of chemicals used and fumes released). It is very easy to do, and can also serve as a ground plane so it makes board design easier.

This is amazing! This is something ive wanted for so long

Nice idea that has real possibilities, even for double-sided boards. Great for those of us that are at the end of the world (NZ :) ) and waiting for JLCPCB / PcbWay takes over a week at the best of times.

Back in the 90s we were taught how to make PCBs at school. You draw the traces on the computer (Acorn Archimedes!) And then print them on the laser printer. You put this and the special photo resist PCB blank into the tiny little UV PCB sunbed and expose. Then you put the PCB blank into the etch bath with its hot vibrating acid. Wash it off, buff it with wire wool and drill the pads with the 1mm bit in the drill press. Good Times.

Final video of the year sounds like a big one!

This is great, going to give it a go, just bought the Saturn

You got me super excited because I have a ton of negative resist boards. Where UV light hardens the resist, your method would be perfect as I no longer have to make exposure masks. I like negative resists because I can use sodium carbonate to develop the boards a less caustic solution.

Interesting approach. The results were quite good.

Thanks a million. This answers my questions about all I wanted to try. You just saved me a bunch of money! THANKSKSKKSKSKSKK!!!

This is a really slick idea. I see lots of comments on toner transfer being better. For large or medium boards, if you already have a laser printer, that's probably true. But for little tiny boards, for small surface mount projects? This looks great. I'm betting the resolution of this direct process is high, and it would work great for 2 or 3 cm boards, that would just be cumbersome toner transfer. Thanks!

Was thinking about this long time ago. Would love to see more attempts on the wet method.

Really great project!

Such a great idea. Thanks Tom

No PCB from JLCPCB was harmed during the making of this video!

Top notch info Tom Thanks for making this video ! stay safe !

Very interesting. I will have to try it sometime. Thank you for the video.

If you want to try the 3d goo as a resist you could try diluting and thinning with a compatible solvent and spin coating it on a plain pcb. It looks like it's a 10x - 100x too thick. Also if the lye is too finicky with timing sensitivity maybe try sodium metasilicate pentahydrate it may be more controllable. Also pretty sure you can get positive or negative uv resists to avoid a step for the image.

I stopped trying to make my own PCBs at home a while back but this was interesting anyway. It makes me wonder if I could try again some day.

Oooo, imagine the artistic uses of just using the lcd screen... So much more potential

Oh my word. I saw the thumbnail and immediately understood. Amazing.

Thanx for this very useful trick : for iterative design, that's can be incredible !!

I don't do 3D printing... but you've got me interested in the idea of making board masks using an LCD... that sounds really interesting.

Wow, fantastic idea! Even an entry-level resin printer would be adequate for a lot of hobby-level boards, and a mid-sized one would be plenty big enough for most anything a typical maker would need to do on a quick-turn basis. (I also second the tip below about using iron-on photoresist film.) Another thought: A 3D-printed jig could help you align the boards accurately enough to do double-sides ones repeatably.

This is very clever, especially the resin on copper pcb. I bet someone comes out with some safe purpose built resins for diy pcb’ing soon.

OMG! the usual thing that has been done for 30 years done with UV lamps! INCREDIBLE

really nice, always wanted to try this. Maybe a good use for my now obsolete photon

That's very interesting! To what level of detail could you get? Do you think this process is applicable for small SMD parts, i.e. 0402 and smaller?

Cool! Laser print on paper still works really well though, once tuned. I don't use film anymore. A "toy" cnc can handle the drilling.

This is so good! Thanks so much for putting this out! A F360 question, @10:55, how did you do the subtract? I extruded the rectangle and then one by one my copper pieces (so a lot), extruded those and then did a number of subtracts and it worked but Im hoping someone can point me a tutorial or how they do that without so much fiddling. I couldnt/cant figure out how to group the copper into one piece to be the cutting tool...???

Very interesting. The results are impressive. Better than laser printing the traces on foil and using a SON-T lamp or the ironing method. Thanks a lot!

just love your content and how you bring always new methods, richtig innovativ!! LG

really usefull, specially when having to do smaller pcbs.

The best description for this method is 'rapid prototyping'. It lets you get your design down perfectly before you send it off to a board fab for bulk manufacture.

So obvious yet so genius. I've mostly gone to getting them made and just waiting now and was using the laser printing before since the photo etching is a bit of a PITA but good to know about. I wonder how this would do for making screens for screen-printing.

This was nostalgic for me. I used to develop photographs in a darkroom and would expose test strips the same way

This is genius! why didn't I think of this before!?!

Awesome video, would love to see more homemade PCBs!

If I’m not mistaken, I think you can also use UVTools to import/replace a layer with an image. So potentially you could turn the tracks into an image with the same pixel dimensions of the printers LCD and drop that into an existing sliced file (and tweak the exposure times)?

BTW you can just draw the circuits with a permanent maker on a transparent film and use that as mask for the pcbs if you have nothing else. My cousin used to do exactly this in the late 80's he started using a sharpie to draw the pcbs, and when he could afford it, he bought an XT PC ( no mouse, no HDD for the first year) and an EPSON dot matrix printer (this was the first PC I ever handled btw) and with a DOS software to draw PCBs ( they looked identical to the ones you show in the vid), he would print the PCB layouts in normal paper, then he would take the prints to a place they photocopied the prints into a Transparent film, and since it was toner ink on the photocopier it was super opaque, and then used these film prints for the photo etching of the pcbs. Eventually he bought an HDD and a genius mouse, At that time he used to build the electronics and antennas for FM radio stations, and he was a 24 year old college dropout xD.

You beat me to trying this ha! Glad they turned out so well! I'm wondering how small of trace width you can push it.

This is incredible.

Using the printer LCD as mask is so smart!