Hi Charles,
The possible problems with larger chip components are two-fold:
(1) Being ceramic these components have a large celta-CTE with FR-4 PCBs.
Thus, in temperature cyclic operational environments they may have inadequate
fatigue life. For a well designed assembly, these components typically are the
ones with the largest reliability threat in telecommunications outside plant
environment (or more severe).
(2) Large chip capacitor are more prone to cracking. This can be helped by
limiting  the size of the solder fillet (or eliminating it alltogether), and
reducing the size of the attachment pads.

Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL  32174  USA
Phone: 904-437-8747, Fax: 904-437-8737
E-mail: [log in to unmask]

################################################################
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 web site (http://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################