Yes, at a previous company we commonly used Rogers 4350 between layers 1 and
2 for high speed impedance controlled signals (1.9GHz) and the rest was FR4,
and in higher quantity will save you a LOT of money on material.

One warning though, you almost have to use the Rogers as double clad
material on the top two layers so the dielectric thickness will be
controlled (and tack on as many single-clad layers of FR4 to the bottom as
you want) but this results in an unbalanced construction no matter how you
do it.
So, make sure you discuss board WARPING with the fabrication vendor in
advance.

Good luck,    Jack

        -----Original Message-----
        From:   Mitch Morey [SMTP:[log in to unmask]]

        I have a "similar" question which hopefully someone can answer. I've
        been asked by our engineering group if FR4 material, is compatible
with
        the Rogers 3000 and 4000 materials? We'd like to make a board using
the
        Rogers material for some circuitry and FR4 material with the other
        circuitry.



################################################################
DesignerCouncil 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 DesignerCouncil <your full name>
To unsubscribe:   SIGNOFF DesignerCouncil 
################################################################
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
################################################################