EP4 – DIY PCB – Laser Etching Experiments

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.

[ForOurGood]

This episode seems popular for YouTube 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. when you finish watching this episode, consider giving a look at those episodes.. Obviously I also recommend checking all episodes in the series too!

[ShopperPlug]

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.

[stephenhumble]

I wonder if you could coat the boards evenly by using an orbital shaker to shake the board and spread the resin out. ?

[enkidu]

nice bit of experimenting there. I've just bought a laser and am experimenting masking and etching a circuit board. I have used the laser printed toner transfer with an iron to very good effect and it's pretty quick as well so i might keep using that method for the mask. Although i haven't done it yet when adding the resin for the solder mask i was thinking i could print the solder pads onto the acetate layer before exposing to UV and if alignment can be kept pretty accurate then I can use IPA to wash away the uncured resin leaving the exposed pads. as you are going through that process already, might that be easier?

[Gippetos]

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.

[charuzusan]

I wanted to ask what you used to measure the accuracy of the lines at 1:27? Did you just print it using transparent paper and a template? If so, do you still have the template on hand? I would like to try using your method. Thank you.

[psialt]

Great findings, thank you! What are the parameters of your laser? Power, speed etc?

[annaoaulinovna]

we should find a coating with a perfect laser burn and resistive against acid etch.

[enkidu]

or maybe we could create the solder mask with stove enamel?

[ArcAiN]

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

[ianbertenshaw]

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 .

[johngreene]

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! 🤷‍♂️

[kapalselam]

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

[murraymadness]

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?

[ShopperPlug]

I hope you don’t breath in the fiber glass pcb dusts. Causes permanent lung damage.