Years ago we used silver or gold plated wirewrap pins and silver plated wire
for boards.
The wrap wire formed a gas tight 'weld' at the junction with the pin edge.
No problems at all with these contacts.
However there were multiple contacts in this case.
Is the force on the connector contact pin enough to cause a similar weld? Is
this the intention of the design?
The connector manufacturer is probably the best person to talk to about
this.
SAMTEC have a similar type of connector to those you describe. The tech
people there are usually quite helpful.

Jim
Jim Thornhill
University of Liverpool
Department of Physics
Oliver Lodge Laboratory
Oxford Street
Liverpool
L69 7ZE
ENGLAND

email  [log in to unmask]
tel 0151 794 3402
fax 0151 794 6774
----- Original Message -----
From: "Jack Olson" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, September 14, 2006 6:04 AM
Subject: [DC] Silver Finish


> We've been using Immersion Silver instead of HASL for several years now.
>
> A new design has connector pins that are held to the surface of the board
> with springs, so there is no solder, just connector contacts touching SMT
> pads.
>
> The silver pads are starting to tarnish,
> but I have heard that silver oxide is conductive.
>
> My questions are:
> How Conductive?
> Is there going to be resistance?
> Is silver okay for switch contacts?
> Does Immersion Tin corrode the same way?
> Do I need to go back to HASL on this one?
> (or is gold not a cost adder anymore?)
> Is this too many questions?
> Should I stop now?
>
> thanks in advance?
> Jack
>
> ---------------------------------------------------------------------------------
> DesignerCouncil Mail List provided as a free service by IPC using LISTSERV
> 1.8d
> To unsubscribe, send a message to [log in to unmask] with following text in
> the BODY (NOT the subject field): SIGNOFF DesignerCouncil.
> To temporarily stop/(restart) delivery of DesignerCouncil send: SET
> DesignerCouncil NOMAIL/(MAIL)
> Search previous postings at: www.ipc.org > On-Line Resources & Databases >
> E-mail Archives
> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
> for additional information, or contact Keach Sasamori at [log in to unmask] or
> 847-615-7100 ext.2815
> ---------------------------------------------------------------------------------
>

---------------------------------------------------------------------------------
DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF DesignerCouncil.
To temporarily stop/(restart) delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL/(MAIL)
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
---------------------------------------------------------------------------------