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A Thermally Enhanced Multichip Thin Film Module

IP.com Disclosure Number: IPCOM000109480D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 1 page(s) / 71K

Publishing Venue

IBM

Related People

Mok, LS: AUTHOR

Abstract

Disclosed is the structure of a thermally enhanced multichip thin-film module. The cross-sectional view of such multichip thin-film module is shown in the figure. The semiconductor chips 11 are connected to the substrate 16 by C4 joints 12. The circuitry is built in the thin-film layers 17 on the substrate 16. The thermal vias 13 which have straight metal sections in the thin-film layers 17 are placed directly under the C4 joints 12. The metal studs 14 were embedded in the substrate 16. A thin polymer layer 18 is coated on the other side of the substrate 16. The soft-metal balls 15 are placed on top of the metal studs 14. Some interface metallurgy which is not shown in the figure may be added between the soft-metal balls and the metal studs.

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A Thermally Enhanced Multichip Thin Film Module

      Disclosed is the structure of a thermally enhanced multichip
thin-film module.  The cross-sectional view of such multichip
thin-film module is shown in the figure.  The semiconductor chips 11
are connected to the substrate 16 by C4 joints 12.  The circuitry is
built in the thin-film layers 17 on the substrate 16.  The thermal
vias 13 which have straight metal sections in the thin-film layers 17
are placed directly under the C4 joints 12.  The metal studs 14 were
embedded in the substrate 16.  A thin polymer layer 18 is coated on
the other side of the substrate 16.  The soft-metal balls 15 are
placed on top of the metal studs 14.  Some interface metallurgy which
is not shown in the figure may be added between the soft-metal balls
and the metal studs.  The soft-metal balls 15 are slightly compressed
when the substrate is put inside the upper metal cap 20 during
assembly at an elevated temperature.  The elastomer-like ring 19 is
used as a guard to protect the substrate from mechanical vibrations.
The module is connected to the printed-wiring board 28 by the flex
connectors 22.  The upper and lower caps 20 and 26 are glued on the
flex connectors 22 by reworkable adhesive 21.  A spring-like thermal
interface preform 27 is inserted between the chip 11 and the lower
cap 26.  The module is supported by the feet 25 at the four corners
of the lower cap 26.  An optional heat sink can be attached to the
upper cap 2...