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Bridged Interstitial Harcon Contact Design for TCM Board Improvements of Double Cable I/O Density And Noise Reduction

IP.com Disclosure Number: IPCOM000100803D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 88K

Publishing Venue

IBM

Related People

Washo, BD: AUTHOR

Abstract

A significant improvement (2x) in both I/O density and noise reduction occurs if a new double-density printed circuit (PC) card (cable connector) featuring 1/1 signal/ground ratio and a signal/ground pitch of 1.25 mm can be utilized in an overall connector package system. The latter use requires compatibility of the mating board counterpart. Standard cable PC card technology uses a 2.5 mm pitch between I/O of ratio of 3 signal/ground. The mating board counterpart here is Harcon contacts on a square 2.5 mm grid with the same signal/ground ratio. This current design is not compatible with the new double-density connector.

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Bridged Interstitial Harcon Contact Design for TCM Board Improvements of Double Cable I/O Density And Noise Reduction

       A significant improvement (2x) in both I/O density and
noise reduction occurs if a new double-density printed circuit (PC)
card (cable connector) featuring 1/1 signal/ground ratio and a
signal/ground pitch of 1.25 mm can be utilized in an overall
connector package system.  The latter use requires compatibility of
the mating board counterpart. Standard cable PC card technology uses
a 2.5 mm pitch between I/O of ratio of 3 signal/ground.  The mating
board counterpart here is Harcon contacts on a square 2.5 mm grid
with the same signal/ground ratio.  This current design is not
compatible with the new double-density connector.

      This invention solves this compatibility problem by creating
two different kinds of Harcon (cable) contacts for the board.  These
new contacts then allow the use of the double-density card connector
technology.  The contact scheme also employs standard thermal
conduction module (TCM) board I/O layout, namely, the staggered 2.5
mm grid instead of the square 2.5 mm grid.

      GROUND INTERSTITIAL HARCON CONTACT This design utilizes the
concept of contacts bridged by a commoning ground shield or rail.
The rail bridges the superstructure for the signal contact (really
the outside coaxial shield of the signal contact design and a
pedestal or foot that eventually is bonded to a ground land which, in
turn, is connected to a board ground via) and an interstitial ground
Harcon contact.  The latter sits on a post which, in turn, rests on
the board surface for mechanical support.  The post is not connected
or bonded to the board.  This design comes off a carrier strip (from
a progressive dye stamping manufacturing fabrication) which allows a
row to be filled with alternating interstitial ground Harcons and
signal shield superstructures (coaxial shield) on a 1.25 mm pitch.
(The coaxial shield superstructure also contains a low dielectric
cylinder insert of TEFLON* or polyolefin polymer which allows
eventual completion of the coaxial design when the signal Harcon pins
are inserted...