Increasing copper/silver layer on PCBs - chemicals advice appreciated.

[irpheus]

Hello All,

I hope this is the right forum to post this question ... Otherwise please feel welcome to move the thread.

As it is I have a need for increasing the copper layer on electronic PCBs and would like to know how to do this. I know it can be done by adding a DC voltage to a "bath" of some kind - where the PCB copper is one of the electrodes and there's another electrode as well. However, since this is not my normal field of work, I'd appreciate if one/more of you can help by clarifying which chemicals are needed - and possibly how this process works. I'd be grateful if there may even be a link(s) to a practical setup for how this can be made to work.

Also, I may have a need to add a layer of silver onto the copper as well. For this task I've previously had very fine help from a Gold Smith I know, however, the "bath" he uses somehow does not allow for the silver to adhere very well onto the copper. It peels off when scraped ... Might there be a way to do this in a way where the silver remains fixed onto the copper (and without any intermediate materials like e.g. nickel)?

Cheers & thanks for any help

Jesper

 

[IRstuff]

Are you planning on doing this as a business? The toxic chemicals involved require a significant amount of infrastructure and paperwork for handling and disposal. It would be better to subcontract this to your current PCB supplier.

TTFN
faq731-376
Need help writing a question or understanding a reply? forum1529


Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com:

http://www.engineering.com/AskForum/aff/32.aspx

 

[irpheus]

Hi ... Thanks for your question - & no I'm not planning on doing this as a business. I'm just frustrated with the PCB manufacturer I'm in contact with and am also thinking that it would be an option to do this myself as it would allow for some flexibility as to how & when to do things. So I'd like to know how it's done - and then if I conclude that it is not feasible in my context (I live in Denmark where the chemicals handling is quite well attended to) I'll have to find other solutions.

Best regards,

Jesper

 

[IRstuff]

Hmm, surprised at that. I would have thought EU would have had very strict controls on chemicals and chemical processing in the workplace.

As for the copper, you probably should be looking for an electroless copper plating. You could, and should, consult with companies like MacDermid, who would supply the chemicals involved:

http://electronics.macdermid.com/do...d Copper Plating for Metallization of PCB.PDF

TTFN
faq731-376
Need help writing a question or understanding a reply? forum1529


Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com:

http://www.engineering.com/AskForum/aff/32.aspx

 

[irpheus]

Hi again - thanks for the link. It looks very relevant & interesting. I'll take a look at it and hopefully I'll get an idea about what it takes to do quality copper plating.

Hmm, surprised at that. I would have thought EU would have had very strict controls on chemicals and chemical processing in the workplace.

I have no doubt that we do - & also the disposal process is being very tightly observed and regulated. However, in this context I'm a private person and so (I assume) there's no official processes or guidelines that I have to adhere to - so less paperwork etc. That said, should I decide to continue with this, I at least will follow official guidelines as to handling & disposal of any chemicals etc. Nature is precious ...

Thanks again,

Jesper

 

[IRstuff]

Well, the copper part should still come from the supplier. You should be able to simply specify 2-oz copper instead of 1-oz (1-oz/ft^2), or perhaps some standard increment in copper thickness of 2.8 mil vs. 1.4 mil.

http://baltimorehackerspace.com/2012/08/pcb-copper-weight-thickness-chart/

http://www.omnicircuitboards.com/blog/bid/324888/How-Copper-Weight-Impacts-PCB-Board-Manufacturing.

That's a pretty routine kind of specification, although I would guess it's in some sort of SI unit in your case

TTFN
faq731-376
Need help writing a question or understanding a reply? forum1529


Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com:

http://www.engineering.com/AskForum/aff/32.aspx

 

[zappedagain]

Clearance requirements increase with copper thickness when etching the PCB surface so watch out for increased potential for shorted copper. Plating may have the same issues.

Why do you believe you need more copper? How thick do you want to go?

Z

 

[irpheus]

Hi IRstuff & zappadagain ...

Thank you both for considering & replying. However, I'm somewhat trying to push the boundaries of what is normally done and also do it in a way that is economically feasible. To that end I've already searched various PCB prototyping manufacturers and the solution I'm looking for will (from my perspective) cost quite some. So I'm looking for other solutions ... and I might just have found one yesterday.

Clearance requirements increase with copper thickness when etching the PCB surface so watch out for increased potential for shorted copper. Plating may have the same issues.

Thanks for noticing this but I'm aware of it.

As I mentioned above I may now have a solution - so for now no need to reply further. Thanks again

Jesper