Browse Prior Art Database

Direct Chip Attach Interconnection System Using Composite Materials

IP.com Disclosure Number: IPCOM000107153D
Original Publication Date: 1992-Jan-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 79K

Publishing Venue

IBM

Related People

Berard, AM: AUTHOR

Abstract

One of the hopes in electronic packaging is to directly mount semiconductor devices to an interconnection system of a computer system without the use of intermediate devices. Currently, these devices are first placed on a ceramic substrate which is individually hermetically sealed and then mounted on to a computer card. If the chips are directly attached to an interconnection system analogous to the card, either by wire bonding, tape automated bonding or C4 attach methods, the final assembly would be greatly reduced in volume and weight.

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This is the abbreviated version, containing approximately 52% of the total text.

Direct Chip Attach Interconnection System Using Composite Materials

       One of the hopes in electronic packaging is to directly
mount semiconductor devices to an interconnection system of a
computer system without the use of intermediate devices. Currently,
these devices are first placed on a ceramic substrate which is
individually hermetically sealed and then mounted on to a computer
card.  If the chips are directly attached to an interconnection
system analogous to the card, either by wire bonding, tape automated
bonding or C4 attach methods, the final assembly would be greatly
reduced in volume and weight.

      There are several requirements which must be met to succeed
with direct chip attachment.  The interconnection system should be
used as the thermal path to cool these devices, and thus must have
high thermal conductivity.  The interconnection system must also have
a coefficient of thermal expansion (CTE) close to that of the silicon
devices.  This property is most important when the C4 attachment is
used as the solder balls will otherwise fail due to thermal
mechanical fatigue.  The interconnection system must also be flat and
mechanically ridged.  Any distortion will cause poor solder joints or
potential breakage of the silicon devices.

      A means of achieving direct chip attachment with such an
interconnection system, is described in this disclosure. Referring to
the figure, the interconnection system is composed of a tailorable
composite material to which dielectric and metalize circuitry is
added on a top surface using thin film techniques.  The
semiconductors devices can then be mounted directly to the surface...