Browse Prior Art Database

Area Array Elastomeric Interconnect Fabricated with Flex

IP.com Disclosure Number: IPCOM000104176D
Original Publication Date: 1993-Mar-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 82K

Publishing Venue

IBM

Related People

Lanzetta, AP: AUTHOR [+2]

Abstract

Anisotropically conductive elastomeric interconnects consist of a conductive material embedded in an insulating elastomeric matrix. Interconnects for high density cards require the placement of many fine conductors within the matrix, especially if redundancy is also required. In prior art [1], wirebonds have been used to form the conductors in area array interconnects. However, since these are individually bonded, the fabrication cost is high and scales with the size of the connector.

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Area Array Elastomeric Interconnect Fabricated with Flex

      Anisotropically conductive elastomeric interconnects consist of
a conductive material embedded in an insulating elastomeric matrix.
Interconnects for high density cards require the placement of many
fine conductors within the matrix, especially if redundancy is also
required.  In prior art [1], wirebonds have been used to form the
conductors in area array interconnects.  However, since these are
individually bonded, the fabrication cost is high and scales with the
size of the connector.

      In the present invention, flexible circuitry is used to form
the conductors in an area array elastomeric interconnect.  The flex
is patterned to the required design - one embodiment would be a
pattern of long, parallel conductors with the supporting Kapton
etched to suspend the conductors across a series of windows (Fig. 1).
In order to obtain the desired array of conductors, the flex is
folded into a suitable configuration.  This is most easily done using
a mold (Fig. 2).  The mold is opened and the flex is wrapped around
it, then it is closed to make a dam for the elastomeric potting
compound.  Silicone  encapsulant is poured into the mold around the
flex.  Once the silicone has cured, the loops where the flex was
folded are sheared off, and the connector released from the mold
(Fig. 3).  The final product is an array of conductors encapsulated
in silicone.

      If the walls of the mold are made relatively thick, small pads
on each conductor could be held within the wall during cure, and then
folded flat onto the connector surface after shearing to form contact
pads.  Alternatively, the ends of the ...