Our multilayer SMT design utilizes SMOBC, the only surface pads are
terminations and test points, and yes, it's for military avionics.  The vias
are filled with epoxy resin and then either coated with solder mask or plated
over on top with copper and then solder coated (via in pad) for test points.
For QFPs, usually the area under the component is an exposed solid metal
surface (solder coated) for heat dissipation.  A film of thermally conductive
tape is used between the bottom of the component and the metal surface.

If you have any other questions, please call.

Jim Marsico
AIL Systems Inc.
(516) 595-5879
[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'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
################################################################