M
Michael (Micksa) Slade
Guest
I've been looking into how to properly finish or repair PCB edge contacts
for use in cartridge slots, PCI slots etc.
This is what I've learned/guessed so far (correct me if I'm wrong):
- gold is the best contact plating metal.
- gold can't be plated on copper or tin, as it reacts with each and
dissolves, or something. the surface first needs to be plated with
some other metal, usually silver or nickel.
- using a tin contact with a gold contact is bad news - most current PCB
edge sockets use gold plated contacts
- the wear of old cartridges and slots is a combination of contact
oxidation and mechanical wear, and in the case of the PCB tracks also
possibly due to the tracks simply being scratched away.
- iso propyl alcohol does a pretty good job of cleaning old oxidised
contacts.
Questions
- is electroplating (for small areas like these) worth trying at home?
- anybody seen/tried the stuff at http://www.palloys.com.au/ ?
It all looks neat but I'm wondering if it can't all be done a bit cheaper.
- I've heard a rumor that there is some sort of package you can get for
AUD $60 or so that will silver and gold plate stuff. Possibly
electroless. Anybody hear of this? In Australia?
- Some older PCB edge sockets (e.g. original nintendo, C64) are silver
coloured, so I guess they use something besides gold. What material would
it be? On the units I'm looking at the contacts look rather rusty.
- is it possible to re-plate the contacts on old sockets/cards somehow?
- I understand that when you're electroplating the item to be plated needs
to be electrically conducting, ie connected to one end of your current
supply. How does this happen for plating of through-hole vias? Are they
done before etching or is every track somehow connected up before plating?
Apologies for any questions that have been asked before
Mick.
--
My email address is "micksa@", not "micksa-news@".
VOTE [1] CAPITAL PUNISHMENT FOR SPAMMERS
for use in cartridge slots, PCI slots etc.
This is what I've learned/guessed so far (correct me if I'm wrong):
- gold is the best contact plating metal.
- gold can't be plated on copper or tin, as it reacts with each and
dissolves, or something. the surface first needs to be plated with
some other metal, usually silver or nickel.
- using a tin contact with a gold contact is bad news - most current PCB
edge sockets use gold plated contacts
- the wear of old cartridges and slots is a combination of contact
oxidation and mechanical wear, and in the case of the PCB tracks also
possibly due to the tracks simply being scratched away.
- iso propyl alcohol does a pretty good job of cleaning old oxidised
contacts.
Questions
- is electroplating (for small areas like these) worth trying at home?
- anybody seen/tried the stuff at http://www.palloys.com.au/ ?
It all looks neat but I'm wondering if it can't all be done a bit cheaper.
- I've heard a rumor that there is some sort of package you can get for
AUD $60 or so that will silver and gold plate stuff. Possibly
electroless. Anybody hear of this? In Australia?
- Some older PCB edge sockets (e.g. original nintendo, C64) are silver
coloured, so I guess they use something besides gold. What material would
it be? On the units I'm looking at the contacts look rather rusty.
- is it possible to re-plate the contacts on old sockets/cards somehow?
- I understand that when you're electroplating the item to be plated needs
to be electrically conducting, ie connected to one end of your current
supply. How does this happen for plating of through-hole vias? Are they
done before etching or is every track somehow connected up before plating?
Apologies for any questions that have been asked before
Mick.
--
My email address is "micksa@", not "micksa-news@".
VOTE [1] CAPITAL PUNISHMENT FOR SPAMMERS