Reply to Doug Jeffery at Electrotek, Inc.


______________________________ Forward Header __________________________________
Subject: About TDR coupons
Author:  Bob Traut at Rogers-R&D
Date:    9/6/95 1:53 PM


Doug:

Andy Magee of Rogers Circuit Materials Division forwarded to me
your 95Sep02 e-mail about TDR coupons, and also a 95Sep05 reply
from Dave Hoover, Hadco Printed circuits, [log in to unmask]

The TDR method in the January 1995 IPC-D-317A Design Guide section
6.0 for high-speed packaging seems to leave a lot of latitude for
designing a coupon and offers a simple TDR test scheme.  Several
years ago IPC Subcommittee D-24 on test methods for high-
frequency/high speed interconnections prepared a 15 page test method
IPC-TM-650 number 2.5.5.7 "Characteristic Impedance and Time Delay
of Lines on Printed Boards by TDR" November 1992.  You may want to
order a copy of that also.  2.5.5.7 should have been a refernce in
317A.  Prior to that I am not aware of any published documentation
of TDR methods or coupons.

G. Robert Traut
Corporate Research Fellow
Advanced Materials Group
Lurie Research & Development Center
ROGERS CORPORATION, P.O.Box 157, ROGERS, CT 06263-0157
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