While it is possible to design functional circuits at 900MHz in FR-4 it is
not generally recommended for circuits with frequencies exceeding 500MHz
Analog or Effective Frequencies of 1GHz.  There are a number of high
performance materials in the market that are much better suited for this
type of application.  Rick Hartley does a presentation on this subject and
the paper he wrote gives several recommendations on the material properties
to be considered in the design of high-frequency designs. His paper is
available in the PCB Design Conference Proceedings or from the IPC.
Jeffrey A. McGlaughlin
PCB Designer
Battelle Memorial Institute
Columbus Ohio
[log in to unmask]


        -----Original Message-----
        From:   Ko Adeline-FSGA2298 [SMTP:[log in to unmask]]
        Sent:   Thursday, 18 November, 1999 07:10
        To:     [log in to unmask]
        Subject:        [TN] PCB board material for high freq product

        > Hi there,
        >
        > My engineer is asking me to design a 900Mhz 4-layer brd using the
        > following information.
        > As this is my first time doing such a high freq brd.
        > I wish to know,  is this PCB material perform excellent in high
freq.
        >
        > PCB Info
        > Top layer     --> 1/2 oz copper
        > Prepreg       --> 2 X 1080
        > Layer 2               --> 1/2 oz copper
        > Prepreg               --> 2 X 7118
        > Layer 3               --> 1/2 oz copper
        > Prepreg       --> 2 X 1080
        > Bottom                --> 1/2 oz copper
        >
        > Brd finishing thickness : 0.031" +/- 0.005"
        > Material : FR4.
        > Plating : Tin / Lead  63/37 HAL
        >
        > Thanks & Best Rdgs
        > Adeline Ko

        ##############################################################
        TechNet Mail List 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://www.ipc.org/html/forum.htm) for
additional
        information.
        If you need assistance - contact Gayatri Sardeshpande at
[log in to unmask] or
        847-509-9700 ext.5365
        ##############################################################

##############################################################
TechNet Mail List 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://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################