WARNING: this is a very unexciting question...

My software does some basic signal integrity analysis,
and I just noticed it defaults the dielectric constant for
regular FR4 to 4.7

I was under the impression that most FR4 is at 4.2-4.3
these days (more resin? thinner cores? can't remember...)

Even a brief response will be appreciated!
                                                                Jack

################################################################
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
################################################################