Browse Prior Art Database

Use of Metal Column Thermal Interface for Cooling Semiconductor Devices

IP.com Disclosure Number: IPCOM000122766D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 1 page(s) / 62K

Publishing Venue

IBM

Related People

Mok, LS: AUTHOR [+2]

Abstract

Disclosed is the structure of a piece of metal-column thermal interface. A cross-sectional view of the thermal interface is shown in Figure 1a. A piece of polymer film 11 has numerous small holes 13 filled with a lead/tin alloy 14. The inner wall of the holes 13 is plated with metal. There are caps on both ends of the metal column. When the interface preform is placed between two solid surfaces, the caps are deformed to achieve intimate contact with the surfaces as shown in Fig. 1b. The deformation is achieved by applying pressure and heat. The best result is achieved by heating the assembly above the softening point of the metal under kiss pressure. Deformation of metal is the key to achieve good thermal conductance between two rough solid surfaces.

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Use of Metal Column Thermal Interface for Cooling Semiconductor Devices

      Disclosed is the structure of a piece of metal-column thermal
interface. A cross-sectional view of the thermal interface is shown
in Figure 1a. A piece of polymer film 11 has numerous small holes 13
filled with a lead/tin alloy 14. The inner wall of the holes 13 is
plated with metal. There are caps on both ends of the metal column.
When the interface preform is placed between two solid surfaces, the
caps are deformed to achieve intimate contact with the surfaces as
shown in Fig. 1b. The deformation is achieved by applying pressure
and heat. The best result is achieved by heating the assembly above
the softening point of the metal under kiss pressure. Deformation of
metal is the key to achieve good thermal conductance between two
rough solid surfaces. In the case where very little pressure can be
applied, the interface can be heated to the melting point of the
solder and let the molten solder fill the gap between the interface
and the solid surface. The metallized holes on the polymer film will
prevent the run-away of the molten solder.

      The thermal conductance will be further improved if the metal
wets the solid surface as in the case of lead/tin solder on copper.
When long and small diameter metal columns, high aspect ratio, are
employed, flexibility of the metal can provide a relief to the stress
created by the mismatch in thermal expansion of two solids by
controlling adhesion bet...