Hello,
        Below is a question sent to me. Does anyone have any suggestions?
Thanks
Rich

I do have a question that you might be able to help me with.  We have a
customer that is building something like an electronic hotel room key
(double sided board) which will be stored for up to 5 years prior to use...
and then the key will be used only once.  We are trying to figure out what
type of surface finish to tell them to use.  There is a single surface
mount IC mounted to the board... otherwise, there are contacts on one edge
that will be used to connect the key to the "lock" when it is used.  In
your experience of talking to the Tech Net people, have you come across a
solution to this type of requirement?  My first inclination is to use Ni /
Au plating with a thick (20+ microinches) deposition of Au.  Being a cheap
double sided board, they are really price conscious, so they want to keep
it as cheap as possible.  I don't know if HASL will provide a good contact
after that long on a shelf...

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################