Browse Prior Art Database

High Conduction Thermal Interface Material

IP.com Disclosure Number: IPCOM000106356D
Original Publication Date: 1993-Oct-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 4 page(s) / 93K

Publishing Venue

IBM

Related People

Bellar, RJ: AUTHOR [+4]

Abstract

This publication is to disclose the experimentation for a reduction of thermal interface resistance without the use of thermally conductive oils or grease.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

High Conduction Thermal Interface Material

      This publication is to disclose the experimentation for a
reduction of thermal interface resistance without the use of
thermally conductive oils or grease.

      The use of direct chip attach and increased chip, power
requires new and novel techniques of cooling at the chip level.  When
using large heat sinks to cool multi-chip arrays, a number of
problems need to be addressed;

1.  Surface irregularities of the interface area will increase
    thermal contact resistance substantially.

2.  Thermal expansion coefficients of the materials in the chip,
    printed circuit card and the heat sink vary.

3.  Tolerances of the parts used must be practical in the
    manufacturing process.

4.  Thermal performance of the assembly must not deteriorate over
    time thereby effecting reliability.

      Flexible devices are being introduced to overcome the above
mentioned problems associated with the chips to heat sink interface.
A common problem of these techniques is the high thermal interface
resistance between the chip, flexible device and the cold plate.
Thermal oils and grease are methods of reducing this interface
resistance.  However thermal grease and oils are not desirable from a
manufacturing stand base migration to other parts of the card such as
connectors and there is a deterioration of the interface due to
drying out and thermal cycling over time.

      The purpose of this experiment was to compare the thermal
resistance of a flexible graphite material of expanded graphite
particles with that of thermal grease between the chip and the heat
transfer device.  This material eliminates the problems associated
with the use of thermal grease and oils.

      A test...