Laser paint pcb method - Page 1
Forum section: electronics / projects

author: pickle9000
author_rank: Super Contributor
timestamp: September 12, 2014, 05:32:45 pm
content: I just ran across this, thought the laser and black spray paint method was interesting. I guess resolution would be an issue but still interesting. I don't know about the high speed copper removal, I'm not sure I do that without a respirator and face shield. I don't do my own pcb's any more and have no inclination to.

author: con-f-use
author_rank: Unknown
timestamp: September 13, 2014, 08:21:36 am
content: The clue train doesn't seem to stop by these guys.

author: Asim
author_rank: Regular Contributor
timestamp: September 13, 2014, 09:02:27 am
content: Very safe !

author: M4trix
author_rank: Frequent Contributor
timestamp: September 13, 2014, 10:29:54 am
content: The topic should be.... How to not etch PCB's! Speaking of which, my recipe for 1L etching solution is, 770ml destilled water, 200ml of 33% HCL and 30ml 30% Hydrogen Peroxide. All that heated up to about 45-50°C in a air bubbler. Etching time is under 10 minutes.

author: rs20
author_rank: Super Contributor
timestamp: September 13, 2014, 11:19:37 am
content: Quote from: pickle9000 on September 12, 2014, 05:32:45 pmThat was one fun video to watch! The laser cutting idea seems brilliant, for those of us that have laser cutters. The etching is probably a bit over the top, but I don'tnecessarilysee any problems with it (perhaps a fume hood would be adviseable...) And, as they mention, when 5 seconds is 10% of your etching time, getting (shall we say) "even process control" might be challengingAlso, sorry, but I have to bite -- I understand that their use of safety gear is dangerously non-existent, but I'm nevertheless a bit puzzled by these replies that make this out to be complete insanity -- perhaps you don't have Chemistry professor parentage like I do :-) Hydrogen peroxide foams, that's what makes it fun! It's not the devil. Staying 100m away from hydrochloric acid (who calls it muriatic acid in 2014, seriously) is one perfectly valid survival strategy, but when I see y'all acting like this is so obviously deadly I kinda feel like it's a fear of the unknown more than anything else. In just the same way that many of you would probably cringe if you hear someone exclaiming "don't stick that multimeter in the wall socket! It'll kill you!" Same thing; those people should be welcome to enjoy a vastly overly conservative view of the dangers of electricity, but when they start thinking that anyone else who oversteps their conservative boundaries is "sure to come to harm", that's when it becomes plain wrong.

author: M4trix
author_rank: Frequent Contributor
timestamp: September 13, 2014, 11:46:55 am
content: rs20,it's not about foaming, it's about etching away the copper traces!Yes, he etched it in couple of seconds but made the board unusable. The undercutting is too fast and the whole center of PCB was etched away. He added too much hydrogen peroxide.

author: rs20
author_rank: Super Contributor
timestamp: September 13, 2014, 12:03:20 pm
content: Quote from: M4trix on September 13, 2014, 11:46:55 amBah, who needs copper traces when you're having that much fun!But yes, I think the OP was more interested in the laser-cutting part, and I am too.

author: pickle9000
author_rank: Super Contributor
timestamp: September 13, 2014, 03:47:02 pm
content: Yes, the laser cutting part is what I found interesting.I'm not familiar with laser cutters. I guess what would be interesting to see is a set of tracks at continually smaller widths and spacing. It certainly looks like you could get dips on board but I can't see any possibility of surface mount. Even so I like the idea.Too bad there wasn't a flatbed inkjet (with ink that worked as resist). You could do your layout, etch and then label the board after.

author: con-f-use
author_rank: Unknown
timestamp: September 13, 2014, 03:52:25 pm
content: What is there to be interested in? The laser engraving part works with pretty much any engraver over 1W. Two passes are a good idea as there will be paint residue.You know it's an old trick, when evenat it.

author: janoc
author_rank: Super Contributor
timestamp: September 13, 2014, 04:06:27 pm
content: Why to rely on expensive (and SLOW) laser cutter to remove the resist when you can use the photoresist instead? Honestly, I don't get it.Moreover, that sort of board could have been done easily using toner transfer too, if you really don't want to bother with photo-lithography.And the etching itself, jeeeze!!!That's waaay too concentrated, apart from etching away the traces, it is dangerous (ever had a pin-sized hole in the glove or the acid splash up?!)! Not to mention that the very corrosive fumes will likely attack and over time destroy whatever metallic he has in that room.Please, kids, if you want to etch your own boards, do it as the sane people do, with ferric chloride, vinegar/salt or ammonium persulphate, using proper safety equipment, not like these two clowns! I certainly prefer having to wait a few minutes more for the board to etch than losing gear to corrosion or an eye to a splash of acid! I have used acid + peroxide once and never more. Just not worth it.

author: rs20
author_rank: Super Contributor
timestamp: September 13, 2014, 10:19:55 pm
content: Quote from: janoc on September 13, 2014, 04:06:27 pmIf you already have a laser cutter, how expensive it is is irrelevant. It may be slow, but all of that time is free time for you - go to the park, have a snooze, get the etchant solution ready, do whatever you want. It seems like a very repeatable process as well. The toner transfer and photolithographic methods are both much more fiddly and require more actual prep time. Laser cutter is just chuck-it-in-and-forget.

author: Legit-Design
author_rank: Frequent Contributor
timestamp: September 13, 2014, 10:39:32 pm
content: Quote from: janoc on September 13, 2014, 04:06:27 pmIs that an acid trip? They start coughing and laughing uncontrollably.

author: pickle9000
author_rank: Super Contributor
timestamp: September 14, 2014, 02:35:42 am
content: This one is pretty cool. Copper removal using a laser.At 1:07 there is a cleanup operation using an "air knife", another term I'm not familiar with.

author: janoc
author_rank: Super Contributor
timestamp: September 15, 2014, 08:51:17 pm
content: Quote from: rs20 on September 13, 2014, 10:19:55 pmI do wonder what sort of resolution can you get from that cutter, as it is not designed to cut really thin traces. Also, you need to cover the board in resist (spray paint it?) first. That's about the same as with photo-lithography, unless you use a pre-sensitized board or the dry iron-on resist films, where you don't have to bother with it. The only extra step is developing the board, which takes a few minutes tops. You could likely have it done in half the time (including etching) that the cutter would spend removing paint, especially on a larger board and with better resolution to boot. I am not sure what is more fiddly here.Tone transfer, yes, that's a PITA. But doesn't require putting hours on a few kilobuck laser cutter (the laser tube has limited lifetime and is rather costly!) nor much fiddling with chemistry (beyond the etching).