Browse Prior Art Database

Flip-Chip Attachment Heatsink with Decoupling Capacitor

IP.com Disclosure Number: IPCOM000112636D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Iguchi, Y: AUTHOR [+2]

Abstract

Disclosed is a heatsink with a decoupling capacitor for Flip-Chip Attachment (FCA). The adhesive used to attach the heatsink to the FCA chip has a high dielectric constant with narrow gap. The narrow gap between the top surface of the silicon chip and the bottom surface of the heatsink makes a capacitor. This structure operates as a decoupling capacitor.

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This is the abbreviated version, containing approximately 100% of the total text.

Flip-Chip Attachment Heatsink with Decoupling Capacitor

      Disclosed is a heatsink with a decoupling capacitor for
Flip-Chip Attachment (FCA).  The adhesive used to attach the heatsink
to the FCA chip has a high dielectric constant with narrow gap.  The
narrow gap between the top surface of the silicon chip and the bottom
surface of the heatsink makes a capacitor.  This structure operates
as a decoupling capacitor.

      The Figure shows a configuration of the heatsink with a
decoupling capacitor.  The silicon chip 10 is attached on a circuit
board 20 by direct chip attachment and the heatsink 30 is attached to
the chip 10 with a narrow gap by a high dielectric constant adhesive
40.  The The heatsink is connected electrically to the card power
plane.  The bottom surface of the heatsink operates as one of the
electrodes of the capacitor.  The other electrode of the capacitor is
the top surface of the chip.  Generally, the silicon bulk of the chip
can act as a common ground for FET devices on the chip circuit, and
this can be used for the other electrode of the capacitor.  This
capacitor operates as a decoupling capacitor for a power-ground line
of the circuit.