silver etching PCB? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: July 13, 2019, 02:45:24 am
content: So since a PCB is pretty thin, and you can make em yourself with epoxy and dielectric or ceramic board, the only question is, is there a etching method?the obvious solution is to use silver power/ground planes and put a copper top plane and make alot of layers, but what if you wanted a silver top?

author: KaneTW
author_rank: Frequent Contributor
timestamp: July 13, 2019, 06:30:10 am
content: Nitric acid.

author: coppercone2
author_rank: Super Contributor
timestamp: July 13, 2019, 08:46:17 am
content: concentration? temperature? additives?

author: MagicSmoker
author_rank: Super Contributor
timestamp: July 13, 2019, 11:04:34 am
content: Quote from: coppercone2 on July 13, 2019, 08:46:17 amIs your google machine broken? I Am Not A Chemist, but a basic search turns up HCl + HNO3 (isn't this "aqua regia"?), 50-70% HNO3 (stronger is not better otherwise the HNO3 will just passivate the surface with an oxide layer) and even concentrated HCl with removal of precipitated AgCl via filtration to drive the reaction to the right.Noxious to hazardous fumes produced in all cases.

author: coppercone2
author_rank: Super Contributor
timestamp: July 13, 2019, 02:19:48 pm
content: its not really defined well for things like under cutting traces and making planer structures against a backer plate as the PCB industry is.yea and google keeps redirecting me to some kind of adult website, can you help me with that??

author: rhodges
author_rank: Frequent Contributor
timestamp: July 13, 2019, 05:15:21 pm
content: I think this is a good forum for chemistry discussions:http://www.sciencemadness.org/talk/You may find an answer by searching. If not, I suggest using "Beginnings" sub-forum.

author: ChristofferB
author_rank: Frequent Contributor
timestamp: July 13, 2019, 07:32:43 pm
content: I'm not sure what you're asking - do you want to make a pcb that's purely silver on ceramic/epoxyresin substrate? or do you want a copper traced pcb that's silver plated? The first one is probably more costly or difficult to do yourself than finding an actual manufacturer.--Chris

author: coppercone2
author_rank: Super Contributor
timestamp: July 13, 2019, 08:16:44 pm
content: yes, I want solid pure silver tracessame process as making a regular PCB, get substrate, press and glue on the silver sheet, mask it, do photo exposureHNO3 will be aggressive to the resists and substrate IMO.http://gossdesignstudio.com/sandranoblegoss/etchingster.htmlFerric nitrate may work.

author: branadic
author_rank: Super Contributor
timestamp: July 13, 2019, 09:29:37 pm
content: Not sure what's the purpose of your task, but silver traces on ceramic are made by thickfilm technology (silk screen printing and backing at about 800°C). Keep im mind, that silver dissolves during soldering, that is why they use thickfilms.-branadic-

author: DaJMasta
author_rank: Super Contributor
timestamp: July 14, 2019, 02:33:35 am
content: If you're looking for a silver top, why not make a regular copper board and plate however much silver you want onto it?

author: IconicPCB
author_rank: Super Contributor
timestamp: July 14, 2019, 04:12:36 am
content: Silver plating calls for some potentially nasty chemicals ( cyanide?)Silver on ceramic substrate is possible as mentioned above... silver ink + stencil + reflow oven

author: coppercone2
author_rank: Super Contributor
timestamp: July 14, 2019, 05:07:56 am
content: so you guys think ferric nitrate etch on a bonded silver sheet to substrate with standard mask won't work?

author: coppercone2
author_rank: Super Contributor
timestamp: July 14, 2019, 05:11:15 am
content: i guess you would need to test minimum solderable silver sheet thickness to see what will survive a solder cycle

author: magic
author_rank: Super Contributor
timestamp: July 14, 2019, 07:28:24 am
content: Is this for some audiophile thing?Quote from: coppercone2 on July 14, 2019, 05:07:56 amInternet says it may work. But why bother if printing and baking works too?

author: vk6zgo
author_rank: Super Contributor
timestamp: July 14, 2019, 07:43:07 am
content: It is possible to silverplate non conductors.I've lost the book that had instructions on how to do it, but I think they used graphite on the non conductor.Too long ago to remember, though!Commercial silver plating materials are not ideal for electronics, as they have impurites added to increase surface gloss, wear resistance, etc.The downside of such additives is that they increase the resistivity to greater than copper.

author: coppercone2
author_rank: Super Contributor
timestamp: July 14, 2019, 03:24:37 pm
content: Quote from: magic on July 14, 2019, 07:28:24 amits a minimum thermal and electrical impedance in given area thing

author: Kleinstein
author_rank: Super Contributor
timestamp: July 14, 2019, 04:20:50 pm
content: There are ways to do silver deposition relatively simple from nitrate - e.g. the way old silver mirrors where made. This would allow a DIY PCB on a glass substrate. However I don't know how good the silver will adhere - this could be a problem and deal breaker. The conductivity of silver is not that much better than with copper, so I doubt it is worth it from this perspective. So it may be possible to use a thin chemical silver layer as a start and than add galvanic copper on top for the main conductor.The etching would than be mainly normal copper. I would expect the normal copper etching solutions to also attack silver, though slower. Possibly still good enough for some 0.1 µm of silver. Alternatively also selective deposition with a negative mask on the silver could be used. So etching would be only through some 0.1 µm of silver (the tricky part here could be finding a suitable protective layer (e.g. tin, gold, NiP?) to protect the copper).

author: coppercone2
author_rank: Super Contributor
timestamp: July 14, 2019, 04:55:53 pm
content: you get thermal and electrical benefitsI don't see why PCB nuts can't be a thingaluminum nitride with silver on topI guess for best performance you would need to flame deposit silver on it or something