Browse Prior Art Database

Anisotropic Wiring Cross-Section

IP.com Disclosure Number: IPCOM000120541D
Original Publication Date: 1991-May-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 3 page(s) / 77K

Publishing Venue

IBM

Related People

Bartley, GK: AUTHOR [+3]

Abstract

Described is a method for tailoring x and y wiring density capability to application requirements.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 61% of the total text.

Anisotropic Wiring Cross-Section

      Described is a method for tailoring x and y wiring
density capability to application requirements.

      This invention is a method for providing an unbalanced wiring
capacity more suited for bus structured applications, such as system
backplanes.  By placing wiring planes at specific distances from each
other and the power planes (see Fig. 1), the electrical
characteristics of the signal planes can be tailored to allow
additional wiring capacity in either the "x" or the "y" axis.

      The sequence of wiring and voltage layers in this cross section
(see Fig. 1) are signal (S1), voltage (V1), voltage (V2), signal
(S2), signal (S3), voltage (V3), voltage (V4), signal (S4).  The
separation between signal and voltage planes is determined by the
desired characteristic impedance of the signal lines.  The separation
between planes S2 and S3 is made large enough to make coupling
between wires on S2 and S3 small compared with the coupling between
wires in the same wiring channel.  Adjacent voltage plane pairs
(V1,V2) and (V3,V4) are assigned to power/ground pairs.  The
capacitance between the adjacent voltage planes provides effective
high frequency decoupling of power plane transients.

      The wirability of this cross section can be further enhanced by
the addition of "y" layers paired with the outer two signal layers.
With sufficient spacing between the two interior signal planes, it is
possible to use both layers f...