EP4 - DIY PCB - Laser Etching Experiments
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- เผยแพร่เมื่อ 10 มิ.ย. 2024
- Lots of experimenting in this episode, as I switch things up, and look using a etch based solution, with the CNC’s laser being used to create the etch resist pattern.
My current plan is to try use the CNC’s laser where ever possible, as I believe this will provide the most accurate and consistent result.
This is the fourth episode in a series where I am challenging myself to make the best possible DIY PCB’s using commonly available low cost CNC technologies. - วิทยาศาสตร์และเทคโนโลยี
This episode seems popular for TH-cam search (good thumbnail?). Anyway, if you are interested in making PCB's, then it is Episode 5 & 7 where we start see some cool results of this all this experimentation. So..... when you finish watching this episode, consider giving a look at those episodes.. Obviously I also recommend checking all episodes in the series too!
Did you just spend 52 minutes for 10 x 10 cm area, really?
@@ihzanursyahbana7773 Yep, something like that, you either love it, or you hate it, everyone has thier own perspective. Personally I really love this process, but that's me! Check a couple of the later videos, if your interest has been tweaked.
@@ForOurGood ohh, no. it was so useful for me, since i need it for another project on my the first plan, i wanna buy it for massive production. unfortunately it took a lot of time for a small engrave area. glad to find this video first before buy it
You need to use 25-50mW UV laser around 350-400nm wavelength. Then use photoresist ink or film and adhere it to the PCB. This will give the best sensitizing etch results. I truly admire your effort in achieving perfection. Great video. Thanks.
Thanks for your support!. I continue to hammer away at improving the process and am have some success, as well as a few stumbles here an there. If you haven't already, check out some of the other videos to see how I am progressing.
we should find a coating with a perfect laser burn and resistive against acid etch.
Your best solution for cutting PCB's on those machines and minimize waste, is to use a v-bit, and score both sides of the PCB, that way, once you've completed all the other operations you have, you can simply snap them apart
Funnily enough, my current solution is to use the laser to score both sides deeply, and then snap the PCB out. It works okay, and you don't need to deal with the dust.. of course you still need to deal with the fumes. Thanks for the comment!
A year late to the party, but for what it's worth...I have been using semi gloss black spray paint as the resist layer. 80% and 600mm/min on a 5w laser to clear the traces, ferric chloride etch has been taking ~12min at room temp, then rinse/wash with glass cleaner and tooth brush. Another layer of the paint and burn pads @ 40%@ 600mm/min.
Interesting to hear someone got the paint to work. What type of feature size are you able to achieve using the paint?
@@ForOurGood Trace size? Something like .25mm near as I can measure. Was shooting for .5mm but had laser kerf setting wrong in Lightburn. Adding kerf offset gets trace and pad size correct but burns the holes too large...had to put the holes on a separate layer in Lightburn. Etching the holes allows the drill bits to self center better. Using Tremclad semigloss black rust paint...dries in 15minutes. Can send a pic or two, but nothing new to you.
@@Gippetos Interesting you point out the extra pass for the holes for self centering when drilling.. I have been struggling to get that to work with my KiCad setup.. some problem with getting KiCad to output the file with the holes or something, I don't remember.. maybe I will take a look at that again and try to solve it. BTW, I have found the UV resin coating reliably gives me 0.1mm, you will see that in later videos. Still, if I could do that with paint, it might be easier. Thanks for taking the time to comment and letting us all know about your experiences.
@@ForOurGood I struggled with getting the holes as a usable dxf. What I am currently doing (right or wrong) is to plot the traces with "small holes" and the edge cut. Make a copy of that dxf and use a cad program (Qcad) to remove all the trace lines...leaving just the holes and the edge cut. I use the edge cut to line things up in Lightburn, then ungroup and delete the edge cut. Output the two layers and save the gcode. As a separate layer, I can change the kerf offset for the holes back to zero. If you try out the program, there's also a setting called flood fill that will save you some time. Paint has some down sides as well. The second coat can lift the base layer on smaller traces making it ugly. Etching is already done, so not an issue besides "ugly".
@@Gippetos Relieved to hear it wasn't just me struggling with the holes.. will use this as a reference when I revisit it. As I mentioned in the videos, the upside of using UV resin is that it is super durable, and also allows for pretty tiny feature sizes, definitely worth a try if you have the kit to do it. Obviously the upside of the paint is simplicity. Maybe you can remove the first layer with solvent before applying the second layer, that would fix your ugly issue... Maybe even use UV resin for the second layer.. don't feel great about having paint as the finishing layer myself.. but that's just me. You should put up a video on your process, I am sure people would be interested to see it.
Great findings, thank you! What are the parameters of your laser? Power, speed etc?
Hi there, and thanks for your question. Take a look in the description of episode 7 of this series, the most recent version of the settings are in there. Be aware that this is a work in progress and I will likely update them once I get everything working even better.
Did I miss where you say why you don’t use photoresist spray since you have a UV exposure/curing capability already? Back in the day (1995?) I used to make all our prototype PCBs this way. Print on a laser printer transparency, spay PCB with photo resist, expose, etch, perfect every time! 🤷♂️
Hi John, thanks for your comment. Check my first episode in this series where I touch on this topic on my experience. Back in the day, I probably made about 100 PCB's using the method you describe, including some small serial production. It works pretty good, originally were using a plotter then photo copying to transparencies. Later I even bought my own mini laser printer which gave a much better result.. But, it definitely wasn't all roses, and I always felt dissatisfied with the process. Maybe reliable feature size 0.8mm was about the limit, and as for trying to get a perfect alignment on a double sided board.. well I didn't even bother touching that snake. And obviously you need the special coated boards, special chemicals and a reliable way to generate then expose the transparencies.. So.. My idea here is to try and shoot for a feature size 0.1~0.2mm (resolution of 0.02mm), and have a multi-processing operations on either sides of the board while maintaining an alignment within 0.05mm. Even though it will not be perfect, I also want to have the board finished to a level pretty close to a professionally manufactured board. So far using the cheap CNC is giving surprisingly promising results, but it’s a work in process, so let’s see where it goes.😎
@@ForOurGood I’ll check out your first episode. I came in at the end here. I always used the spray photoresist which comes in a rattle can like spray paint. Easier to use than the UV cure resin you are using here. Two sided PCBs with .2mm traces was easy. Registration wasn’t an issue that I ever ran into. I have a small photo essay I made back in 1999 on Facebook if you are interested. It was a quick and dirty prototype so nothing fancy I was just trying to document the process back in a time before TH-cam and Facebook! I have a desktop CNC that I also do PCBs with but I am finding the process isn’t as good.
@@johngreene3633 Hey, at least you made it here at all, so thanks! I think I cover many of the things you raised in the first couple of episodes. I also have come up with a much easier way to lay the UV resin which also gives superior results. Will show that in the next episode.. maybe a week or so from now.
I recall watching a video where they used flat black enamel paint sprayed onto the copper as a resist and burned it off with a laser .
I think maybe I remember seeing r something similar too, and suspect more experimentation would likely flush out a couple more candidates. So far the experimentation seems to show that hardiness and consistency of the applied surface are more important factors than first came to mind. I really like the mask resin result, and it's a process I am already using, so less to deal with. Maybe I will look for an easier way to apply the resin in the future, and possibly try a few different colours too. Thanks for the comment!
@@ForOurGood
Thomas sanladerer also used a resin printer to make a mask for a circuit board - he used a resist that was activated by UV and the lcd panel on the resin printer id used as a mask.
@@ianbertenshaw4350 Had a similar comment about that in the last episode. Actually I remember seeing something like that before, and did consider it, but basically I wanted to stick to the 3018 CNC as the primary tool for this challenge. Might give it a go in the future though!
Hi sir.... currently I'm using laser 500mw....& Try to engrave PCB board....but it didn't work or burn the pcb ...is it because of the watt value or setting the speed on lasergbrl software....your response is highly appreciated sir
500mw... sounds pretty low power for making PCB's even using my method. However, it still might be possible to at least clear the UV resin etching mask, but you will need to do some testing to find the correct speed. I expect you would need to run at full power, so only the speed, or possibly the number of times you run the same job, seem like the only variables you control. You said "it didn't work to burn the PCB".. but can you be specific about what exactly you tried to burn on the PCB? Which specific process. Thanks for the question!
@@ForOurGood what I mean with "burn" is....my laser didn't work on PCB even I setting up the speed many time....& I am Also setting the dot size of laser make it tiny...also didn't work....it only work for other materials such as wood....can u advice me which type of laser & the watt size that can work on PCB
@@kapalselam8162 Sorry, I dtill dont understand. That small laser cannot burn the copper on the PCB, only super powerful lasers can do that. If you are trying to burn the UV resin coating on the PCB for chemical etching (same as I demonstrate in this video series), then that might be possible (if it burns wood I expect it will burn a thin layer of resin). Is that what you are trying to do?
@@ForOurGood yes.... currently I'm try to apply your method on my PCB....but it's not working....as per I mentioned that my laser is 500mw & then u said that watt size is pretty low ....so what is the watt size of laser that will working to apply method as Ur video shows
@@kapalselam8162 OK, now I understand. You can find the most current information about my hardware setup and the software settings I used located in the description of episode 7 of this series please, check it out. If you are using the exact same UV resin, then I am a little surprised you are not able to burn it with the 500mW laser, but possibly that is just the way it is. Either way, I definitely recommend a more powerful laser, at least as powerful as the one I used in this series. Good Luck!
I know this is a year ago..but it seems like you are doing this backasswards. Using uv mask, exposing all of it, and then try to laser it off? Paint the mask and then laser WHAT YOU WANT TO KEEP! then you wash the rest away. That is how you do it manually. What I want to see someone try is to use a 3d printer/plotter to paint the mask only where you need it and then uv expose it, so there is no wasted mask. And then do the same for the solder mask and silkscreen after etching. Isnt that how production is done?
I fully agree, it's a total disaster. Pretty sure there are other channels out there with much better ideas. Keep searching, you will find what you're looking for! Thanks for the comment 👍
I hope you don’t breath in the fiber glass pcb dusts. Causes permanent lung damage.
Thanks for your comment and concern. Actually by using the laser to cut out the PCB I greatly reduce the dangerous dust. I also use a filtered fume extraction just to be safe! Actually using the laser to burn the UV resin also creates some dangerous fumes, so safety first!