|
|
Article: Still good bang for the buck: OI' faithful FR-4 shows no signs of fading into that good night.(No Myths Allowed)
- Article from:
- Printed Circuit Design & Manufacture
- Article date:
- February 1, 2005
- Author:
CopyrightCOPYRIGHT 2005 UP Media Group, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
I often hear the questions: When will copper reach its limits? When will it be necessary to switch to optical interconnects? Actually, we should be asking when FR-4 will reach its limits, and what will we do about it? The answer is, pretty." soon. Fortunately a new generation of materials with an attractive price/performance ratio is ready to give FR-4 a "mid-life kick."
The limitations of FR-4 are most noticeable in high-speed serial links with data rates in excess of 2.5 Gbps and in backplane traces longer than 12 inches. As a signal propagates down a transmission line built with FR-4 laminate, the higher-frequency components will be attenuated more than the ...