Neal -

Most, if not all, of the parts manufacturers have done some pretty respectable
qualification testing on their parts.  In most cases this includes
determination of the levels of moisture sensitivity and, for lack of a better
term, "process durability".   I have received some really good information on
the care and feeding of various BGA packages and PQFPs.  The applications
engineers at most manufacturers are very helpful in this respect, but you may
have to go back more than once to get all of the answers you need for your
design and assembly situations.

Case in point:  I'm looking at a chart from Motorola which provides data on
preconditioning requirements for SMT devices prior to relibility testing.  It
gives a summary of "customer floor life before bake" for six different classes
of devices, ranging from a minimum of 6 hours floor life to indefinite
(probably metal or ceramic case).

Regards - Kelly

################################################################
TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################

################################################################
TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################