TECHNET Archives

May 1999

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Andy Slade <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Thu, 6 May 1999 09:26:06 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (67 lines)
     Hi Simon,

     This might be a stretch, so others, feel free to beat me up...

     The formula one of our laminate suppliers uses for determining
     theortical Dk of FR-4 materials is:

     Dk=6.3*(Tglass/Td)+3.6*((Td-Tglass)/Td), where

     Tglass = thickness of glass cloth (in mils)
     Td = overall thickness of dielectric
     6.3 = Dk of glass (at 1 Mhz)
     3.6 = Dk of FR-4 epoxy resin (at 1 MHz)

     Assuming you know the Dk and thickness of each of the materials in
     question, I don't see why you couldn't apply the above formula.
     Change the 6.3 to the Dk of one of the materials, the 3.6 to the Dk of
     the other material.  Substitute the thickness of the first material
     for Tglass, and Td is equal to the combined thickness of both
     materials.

     Hope this makes sense...Andy


______________________________ Reply Separator _________________________________
Subject: [TN] Dielectric Calculation
Author:  Simon Butte <[log in to unmask]> at smtplink-hadco
Date:    05/05/99 4:04 PM


Hi Everybody,

Is anyone know how I can figure out the effective dielectric constant when 2
different
Dielectric materials are placed together. Is there any document I can find in
the web.
Any input is appreciated.

Simon Butte
Email   : [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
################################################################

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


ATOM RSS1 RSS2