Browse Prior Art Database

Retention of Chip Carrier Substrates

IP.com Disclosure Number: IPCOM000119280D
Original Publication Date: 1991-Jan-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Related People

Bickford, H: AUTHOR [+3]

Abstract

High-Speed packaging of Josephson circuit chips is known where several chips are joined to carrier substrates, using mercury for the electrical contacts. Several carriers are made to communicate with one another by connecting them around the periphery, with bridging modules carrying mercury contacts. This arrangement of carrier substrates on a base plate allows for attachment of I/O cables and other hardware. The forces arising from the surface tension of the mercury during coalescence of mating arrays of contacts affords a self-aligning feature. Since the carriers are at liberty to seek stress-free equilibrium positions, the retention locations of the substrates are not fixed on the base plate.

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Retention of Chip Carrier Substrates

      High-Speed packaging of Josephson circuit chips is known
where several chips are joined to carrier substrates, using mercury
for the electrical contacts.  Several carriers are made to
communicate with one another by connecting them around the periphery,
with bridging modules carrying mercury contacts.  This arrangement of
carrier substrates on a base plate allows for attachment of I/O
cables and other hardware.  The forces arising from the surface
tension of the mercury during coalescence of mating arrays of
contacts affords a self-aligning feature.  Since the carriers are at
liberty to seek stress-free equilibrium positions, the retention
locations of the substrates are not fixed on the base plate.  In
order to provide a retention scheme for holding the chip carrier
substrates to the base plate, mating of perpendicular arrays of
linear mercury contacts on the carrier substrate and base plate is
used.

      In the figure, a base plate 10 has an array of
mercury-supporting contacts 12 elongated across the active area in
the Y-direction.  The backside of the carrier substrate 14 is also
provided with an array of identical contacts 16 which, however, are
elongated in the X-direction.

      To assemble the carrier substrates on the base plate, the
contacts 12 and 16 are mercurized and then carrier substrate 14 is
placed on the base plate 10 in its approximate position.  A second
carrier substrate is then placed adj...