Silvering PCB's - Page 1
Forum section: electronics / general

author: DkinG
author_rank: Contributor
timestamp: April 20, 2015, 09:14:26 pm
content: Hello, I would like to know if there is a method for silvering the copper of the PCB.I have Silver Nitrate, I saw a lot of videos where many people and students makes silver from it, so i wonder if i can make any homemade silver bath for the PCB using the Silver Nitrate. I can get some chemical stuff so if anyone knows anything about this process, I'll apreciate you can share the information.Thanks and sorry if my english is not good, I'm a Chilean.Cheers!...David MixElectronics Engineer

author: c4757p
author_rank: Super Contributor
timestamp: April 20, 2015, 09:22:11 pm
content: Any particular reason it has to be silver? You can easily buy chemicals to tin-plate copper.

author: DkinG
author_rank: Contributor
timestamp: April 20, 2015, 09:26:14 pm
content: Yes, as i know, Silver is more conductive than Copper, and it doesnt rust like copper...P.D: I would like to explain a lot more about this but my english is so poor...Cheers!!...

author: PeterFW
author_rank: Frequent Contributor
timestamp: April 20, 2015, 09:37:19 pm
content: Electrolysis is a bit tricky sinve you will have a hard time electrically connecting every copper part.But you can buy the stuff to silver plate copper using a cotton swab, but...Quote from: DkinG on April 20, 2015, 09:14:26 pm...there we have a problem, because i do not know the spanish word for the stuff and never seen the chemical formula mentioned.One of the german brand names is "anreib silber" the next best english thing i could find is "Secret Instant Silver".But this stuff is a bit toxic, does it have to be silver?You can tin plate a PCB with this stuff:MG Chemicals 421 Liquid TinThis will work even better then silver...Greetings,Peter

author: nanofrog
author_rank: Super Contributor
timestamp: April 20, 2015, 09:52:52 pm
content: As others have asked, is there a specific reason it MUST be silver?I ask, as there are alternatives that are both less expensive and easier to do that will prevent the copper from oxidizing. Tin plating would be one, another would be to just use solder.

author: DkinG
author_rank: Contributor
timestamp: April 20, 2015, 09:57:57 pm
content: I don't know if there is something better than silver... I think you can give me any sugestion..Greetings...

author: Zad
author_rank: Super Contributor
timestamp: April 20, 2015, 10:02:50 pm
content: Silver does oxidise, just like copper does. If you need better conductivity, the usual way is to use thicker copper in the PCB, or to coat the PCB trace in solder (Dave has done a video on this).

author: nanofrog
author_rank: Super Contributor
timestamp: April 20, 2015, 10:30:00 pm
content: Quote from: DkinG on April 20, 2015, 09:57:57 pmBetter in what sense?If you're thinking in terms of conductivity, keep in mind that although silver is technically better than copper, you're only talking ~ a 7% increase. Cost OTOH, is much higher for silver, so it's only used for special applications when that additional conductivity is necessary.

author: sleemanj
author_rank: Super Contributor
timestamp: April 20, 2015, 10:32:25 pm
content: Cool-Amphttp://www.cool-amp.com/

author: hugo
author_rank: Regular Contributor
timestamp: April 20, 2015, 10:56:04 pm
content: Hi,Liquid Tin by MGC, although a bit expensive it's probably the most popular :- provides excellent solderability- protects against oxidationhttp://www.mgchemicals.com/products/prototyping-and-circuit-repair/prototyping/liquid-tin-421/

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 20, 2015, 10:57:08 pm
content: Silver is a poor choice, because of several reasons:- The conductivity is not much better, so you're almost always wasting your money. Unless you're extremely space-constrained, it's cheaper to simply use more copper.- When it does matter, it's usually concerning the underside, where current flow is predominant (i.e., GHz+ range RF losses), where you can't plate anyway. You'll save much more going from FR-4 to Rogers laminate in that case, too.- Over time, silver diffuses into the copper, leaving a porous, less-conductive alloy on the surface.- Silver tarnishes, so not only is its advantage lost over time, but the solderability fades quickly.If a silver surface were required, it would be best achieved with a nickel layer first, which prevents the diffusion reaction. This would be worse for RF applications, because nickel is very lossy, even if it has a modest layer of silver on top.ENIG is, literally, the gold standard in PCB fabrication. The electroless nickel (EN..) layer prevents diffusion, while the immersion gold (..IG) provides corrosion resistance and excellent solderability (boards retain solderability for... years?), and good contact (particularly for "hard gold" plating on edge connectors).Solder dip (HASL) is probably the second best, since although the tin (or alloy) layer can oxidize, the relatively thick layer of clean metal beneath the surface allows plenty of opportunity for fluxes and solder to work, even on relatively oxidized boards. It's also easy to apply to hand made PCBs, tinning with the soldering iron.Tim

author: nixfu
author_rank: Unknown
timestamp: April 21, 2015, 01:37:21 pm
content: Silver is MUCH harder to solder to than copper.