How to get a visibly thick PCB trace? - Page 1
Forum section: electronics / projects

author: rea5245
author_rank: Frequent Contributor
timestamp: August 01, 2022, 03:47:49 pm
content: One of my hobbies is re-creating Robert Tinney's BYTE covers as photographs. I want to make a PCB to recreate the image, below. I figure I should get an ENIG finish, and make sure the solder mask doesn't cover the traces.But can anyone offer advice on the copper weight and gold thickness? JLCPCB offers 2oz copper and 2 U" (microinches??) gold thickness. Will that be visibly thick? Should I go with another company that offers even heavier copper? Is it worth paying for the extra gold thickness?Thank you.

author: wraper
author_rank: Unknown
timestamp: August 01, 2022, 03:57:27 pm
content: Ordering this from a PCB fab is realistic but will be very expensive.

author: rea5245
author_rank: Frequent Contributor
timestamp: August 01, 2022, 04:00:35 pm
content: Quote from: wraper on August 01, 2022, 03:57:27 pmHow so? JLCPCB, with 2 oz copper and 2 U" gold would be about $50. Or are you saying I need more than that?

author: wraper
author_rank: Unknown
timestamp: August 01, 2022, 04:01:15 pm
content: Here is a 20 oz example. 2 oz is what you see on most of consumer PC motherboards.

author: wraper
author_rank: Unknown
timestamp: August 01, 2022, 04:12:17 pm
content: Quote from: karpouzi9 on August 01, 2022, 03:53:25 pmThe problem is etching 0.5mm of copper anywhere decently is not realistic. You can mill it though.

author: langwadt
author_rank: Super Contributor
timestamp: August 01, 2022, 06:42:00 pm
content: Quote from: wraper on August 01, 2022, 04:12:17 pmshields like these made by etching before bending,https://techetch.com/wp-content/uploads/2020/11/Board_Level_Shielding.jpganyway, here's pic of a 20oz board, I believe it cost $2000https://usercontent.irccloud-cdn.com/file/gHochdce/irccloudcapture-1320676838.jpg

author: wraper
author_rank: Unknown
timestamp: August 01, 2022, 07:14:38 pm
content: Quote from: langwadt on August 01, 2022, 06:42:00 pmThey are much thinner than 0.5mm and are etched from both sides simultaneously. Nor they are made from copper, dunno how much it matters. I just have to say that DIY etching 2 oz copper nicely is already a challenge for DIY, not like thinner copper is easy to make in good quality without experience and right tools.

author: tszaboo
author_rank: Super Contributor
timestamp: August 01, 2022, 07:33:57 pm
content: Quote from: langwadt on August 01, 2022, 06:42:00 pmBut why would someone make a PCB like that? Is it just bad engineering or did they actually have a reason?

author: langwadt
author_rank: Super Contributor
timestamp: August 01, 2022, 11:02:37 pm
content: Quote from: tszaboo on August 01, 2022, 07:33:57 pmI got it from some reddit thread the poster said it was for a formula E car, making 13.8V@150A from +/-450Vhere's the other sidehttps://usercontent.irccloud-cdn.com/file/ZjnBND2U/irccloudcapture-236812244.jpg

author: Someone
author_rank: Super Contributor
timestamp: August 02, 2022, 02:02:11 am
content: Quote from: wraper on August 01, 2022, 04:12:17 pmThere is also deposition on a negative mask:https://www.lintek.com.au/

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 02, 2022, 02:10:07 am
content: Quote from: Someone on August 02, 2022, 02:02:11 amThis also came to mind!Yeah, the problem isn't even so much the aspect ratio, though it is a concern -- the sidewall geometry is the hard part.Tim

author: wraper
author_rank: Unknown
timestamp: August 02, 2022, 06:55:04 am
content: Quote from: Someone on August 02, 2022, 02:02:11 amBut you certainly won't do it yourself.

author: langwadt
author_rank: Super Contributor
timestamp: August 02, 2022, 07:26:59 am
content: Quote from: wraper on August 01, 2022, 07:14:38 pmthe can be thicker than 0.5mm, usually made from nickel silver which is mostly copper but more corrossion resistant, but can be done in copper for things like busbarshttps://ace-uk.net/processes/copper-etching/https://www.ksunrise.com/chemical-etching-pcb-shielding-cans/

author: Someone
author_rank: Super Contributor
timestamp: August 02, 2022, 07:29:26 am
content: Quote from: wraper on August 02, 2022, 06:55:04 amSo?OP asked about sending out a design for fab. Want to be a dick about it?Perhaps show us some micrographs of DIY milling on 0.5mm copper if you're so set on it as the solution?That sounds equally difficult to DIY, I'd guess easier access to water jet or laser cutting at those feature sizes and finishes (as T3sl4co1l points out, its all about the "wall" finish/geometry). Also it so happens I've easier access to lasers and deposition than precision mechanical milling, hence they come to mind.

author: wraper
author_rank: Unknown
timestamp: August 02, 2022, 08:22:18 am
content: Quote from: Someone on August 02, 2022, 07:29:26 amSo actually read to what you reply. I said it can be made by a fab in my first post in this thread (reply #2). Particular discussion was about making it yourself.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 02, 2022, 11:40:21 am
content: Quote from: wraper on August 02, 2022, 08:22:18 amI don't... what even?OP wants to do a thing:We all want to help OP do the thing*.OP suggests fab would be fine.Comment suggests more hand-made solution.Following comment chain ponders a bit more about hand-made solution.Comment chainconnects hand-made solution back to a possible fab solution.Comment chain gets upset it's no longer a purely hand-made solution.Like... is it somehow a travesty that someone might save labor doing a better job with a more optimal fab solution, versus doing it by hand? It's not like anyone has anything invested in things they've put forward here*. Talk is cheap, everything is just ideas so far. No need to all get excited about anything (well, hopefully aside from OP's eventual creation).Accidental misread of tone of voice? Internet communication is hard; it happens, no need to assume the worst. Unfortunate that we are so often conditioned to do so, sometimes we need reminders, to check again, give that benefit of a doubt. If in doubt, ask for clarification, it takes two to communicate and all.*Assumption.Anyway.......Waterjet is a good idea; or laser, preferably not with copper though (or are short-wave lasers common and powerful enough to offer that now, I forget?), but aluminum and steel certainly could. Or, hell, what's material really matter anyway, build it out of painted cardstock or what have you?!What scale is this on, anyway? -- I had assumed since OP was asking about fairly ordinary fabs, it would be at quite some magnification. You will indeed see 2oz copper in relief with a reasonable macro lens, let alone higher magnification -- but the traces will be quite small, and I think people are making assumptions about what the background is, and whether it's to be all one, or can be composited (which hasn't been mentioned, but is worth asking!).If real PGA and DIP parts will be used, yeah, scale is definitely on the order of 20 mil / 0.5mm stock, and waterjet/laser would be economical means to handle that. These are still pretty small parts, so they may have some trouble getting them clean (particularly with waterjet, but laser should be quite capable). Hand finishing the edges wouldn't be the end of the world, at least.The other thing suggesting flat stock, of course, the pronounced line of shadow under the pieces. Clearly the artist exaggerated the look, well away from how PCB looks. If OP wishes to reproduce that aspect, then flat stock, loosely glued in place, would seem to fit nicely.On the other hand, if something truer to industry is desired, perhaps recreating the pattern in real fabbed material is best. The background clearly won't be to scale with such, if the height aspect shall be preserved; and maybe that can be composited in, or a scaled equivalent found and used, or the height aspect simply flattened to stay truer to the materials/objects implied in the original piece.As far as verbatim imitation versus artistic license versus realism, I think I'd say OP takes a mix of all three. For reference:https://www.galacticstudios.org/byte-magazine-cover/So, any of the above methods and resulting styles, feels plausible and worthy of mention.What ever it is, I look forward to the result.Tim

author: rea5245
author_rank: Frequent Contributor
timestamp: August 02, 2022, 12:05:03 pm
content: Quote from: evb149 on August 02, 2022, 03:38:46 amNope! My rule is that it has to be photograph(s) of real-life objects.Here's my previous pics:

author: wraper
author_rank: Unknown
timestamp: August 02, 2022, 12:28:58 pm
content: Quote from: T3sl4co1l on August 02, 2022, 11:40:21 amNot really. I got quoted talking about DIY solution with suggesting a fab-only solution. If Someone didn't want me saying it's a fab-only, he shouldn't have been quoting me talking about DIY, because as minimum it is not relevant. And quoting me in that post basically implies DIY. IMHO he's the "dick" here for calling me being a dick because I wasn't impolite when simply saying it's not suitable for DIY. Nowhere I said OP shouldn't use a fab, only said that it's certainly possible but will be expensive. I actually did not even suggest doing it DIY and said that etching PCB with 0.5mm copper will not work.

author: Nominal Animal
author_rank: Super Contributor
timestamp: August 02, 2022, 01:14:32 pm
content: Quote from: rea5245 on August 01, 2022, 03:47:49 pmThere are online services that will laser-cut brass; 0.06" or 1.5mm thick sheet seem to be available at services like Ponoko. I would use those, with the traces connected to an outer rectangular frame just outside the picture area. You can use 400 or higher grit wet-or-dry sandpaper with e.g. WD40 as a lubricant to round the edges slightly, so you get the same effect as in the picture. If you put a sheet of 400-1200 grit on top of a mirror, you can then flatten the brass, and finally use Brasso or similar polish to get a really nice golden-brass finish.If you're not happy with that color, you can use electroplating to plate the brass with some other metal, or use gold leaf to gold-plate it.For the substrate, I'd look into polystyrene and foam PVC sheets available in hobby stores (that modellers use), and using diluted acrylic or watercolor paints to color it, with the intent of letting some light pass through from below to make it have that not-completely-opaque PCB feel to it; maybe even add shadows on the bottom for added detail?

author: tszaboo
author_rank: Super Contributor
timestamp: August 02, 2022, 09:26:38 pm
content: Quote from: T3sl4co1l on August 02, 2022, 11:40:21 amTim, you have way too much time to type walls of texts.Quote from: langwadt on August 01, 2022, 11:02:37 pmOk, looking at the other side it is starting to make sense. With those tiny tracks, empty space and huge copper thickness I was starting to get the wrong idea.

author: Someone
author_rank: Super Contributor
timestamp: August 02, 2022, 11:32:58 pm
content: Quote from: wraper on August 02, 2022, 12:28:58 pmLol, DIY or not the point remains mechanical milling (although often more accessible to DIY) is unlikely to get the surface finish. Or can you show some examples of such?You added the DIY requirement and dimissed on topic discussion as it didnt meet your newly added/invented requirement. We're calling you out on that. Also....The issue that this thread is discussing, what processes could acheive that "look". Which I'll continue to contend, mechanical milling wouldn't do it.

author: Someone
author_rank: Super Contributor
timestamp: August 02, 2022, 11:51:43 pm
content: Quote from: T3sl4co1l on August 02, 2022, 11:40:21 amTo round out the possibilities, EDM wire cut can have similar edge quality to a waterjet except super square with no taper/focus that you have in water/laser cuts.Lasers, typical commercial models are still pretty slow needing multipass paths to cut:a better look at the sort of edge finishes achievable without any special effort:

author: wraper
author_rank: Unknown
timestamp: August 03, 2022, 05:30:04 am
content: Quote from: Someone on August 02, 2022, 11:32:58 pmI did not add any requirements, as if you are blind and cannot possibly read what I actually wrote. You literally quoted me replying to karpouzi9 talking about DIY method with a link to fab only (which should imply it's about DIY), and got offended by my remark that it's not suitable for DIY. As of milling, you can do it with a $150 CNC milling machine and get quite acceptable results. Heck you don't even need a thick copper, you could simply mill deeper into FR-4 to get a look that traces are thick. If you want gold finish, it's not that hard to do it DIY either.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 03, 2022, 05:32:28 am
content: Quote from: tszaboo on August 02, 2022, 09:26:38 pmIf you're only just noticing this, I must be doing something wrong!Tim

author: Someone
author_rank: Super Contributor
timestamp: August 03, 2022, 06:27:29 am
content: Quote from: wraper on August 03, 2022, 05:30:04 amLets pick this apart since you have decided on "dick"....Quote from: wraper on August 03, 2022, 05:30:04 amWe can all see what was written, I'll quote it again below.Quote from: wraper on August 03, 2022, 05:30:04 amO'rly? Lets check those quotes!@Quote from: Someone on August 02, 2022, 02:02:11 amSo that's a link with/in addition to mentioning a possible manufacturing method the OP may not be aware of, that site has quite extensive detail on their implementation.Quote from: wraper on August 03, 2022, 05:30:04 amYou seemed to get tetchy first by shutting down discussion of non DIY when no-one but you is saying that's an important criteria. Lets recap:Quote from: wraper on August 02, 2022, 06:55:04 amTechnical discussion about challenge of etching (zero mention of DIY or not), point about milling overcoming that issue (still no mention of DIY or not), counterpoint about deposition being an alternative solution (nothing about DIY). This discussion is pretty valid regardless of DIY or not, but you're arguing off to infinity that you can decide DIY is the important thing, despite never being mentioned in the comment branch/thread you are taking so much issue with.Quote from: wraper on August 03, 2022, 05:30:04 amposting an unreferenced promotional photo of milling from a $4,000 machine is somehow related to that?Look through the thread, you are theonlyone talking about DIY at all. This is becoming comedic how self centred you are in trying to take over the thread and decide what should/shouldn't be discussed, against what is clearly mentioned by the other posters and OP. The OP literally asked for suggestions of manufacturers!Quote from: rea5245 on August 01, 2022, 03:47:49 pmBut somehow you're still making some issue about posting a link to a.... manufacturer who offers radically different PCB fabrication capabilities.

author: wraper
author_rank: Unknown
timestamp: August 03, 2022, 07:36:55 am
content: Quote from: Someone on August 03, 2022, 06:27:29 amIt's you who decided to be one, since you started calling names on a slightest "offense" which wasn't even offending in any way.QuoteYou sure are a master of fighting straw man. I shut down nothing, just said that particular method is not suitable for DIY because you quoted my comment about DIY. BTW if it's not obvious to you, my comment about etching 0.5mm was about DIY. Since it was a reply about DIY, I thought it was obvious enough. It would be pretty strange if I first said it can be done by PCB fab, and then say exactly opposite.QuoteThat's a photo of how it looks if you mill too deep (with a desired effect to the OP). If it's a promotional photo of $4000 machine, then it's a rather crappy promotion since it's not how it should be done properly.Here is PCB milling on $150 machine:

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 03, 2022, 08:47:37 am
content: How about DIY electroplating to thicken it up?

author: eugene
author_rank: Frequent Contributor
timestamp: August 03, 2022, 02:40:05 pm
content: Quote from: rea5245 on August 01, 2022, 03:47:49 pmSince it's not going to be part of an actual electronic circuit, does it really need to be conductive? Can you just cut it out of a sheet of plastic or cardboard and paint it? If you don't want to use scissors then contract someone with a laser cutter. They need a vector pdf drawing.Or how about using a common FDM 3D printer?