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Method to Control Expansion and Contraction of an Integrated Circuit Package

IP.com Disclosure Number: IPCOM000118845D
Original Publication Date: 1997-Aug-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 1 page(s) / 26K

Publishing Venue

IBM

Related People

Kresge, JS: AUTHOR [+4]

Abstract

A package containing a silicon Integrated Circuit (IC) is subjected to extreme mechanical stresses during temperature cycling. The large differences in thermal expansion coefficients between the silicon IC and the package substrate results in severe deformation and stress when these two materials are firmly coupled together and subjected to extreme temperature variations. The stresses can be large enough to fracture the silicon IC.

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Method to Control Expansion and Contraction of an Integrated Circuit
Package

      A package containing a silicon Integrated Circuit (IC) is
subjected to extreme mechanical stresses during temperature cycling.
The large differences in thermal expansion coefficients between the
silicon IC and the package substrate results in severe deformation
and stress when these two materials are firmly coupled together and
subjected to extreme temperature variations.  The stresses can be
large enough to fracture the silicon IC.

      A method to avoid the deformation is to include a heater and
cooler in the package that will minimize the temperature variations
within the package.  An example of this is shown in the Figure; a
ThermoElectric Cooler (TEC) is attached directly to the back side of
the silicon IC.  Appropriate sensors are also mounted in the package.
When ambient temperatures vary widely, the TEC will either cool the
package or heat the package and prevent the extreme temperature
variations that  cause deformation and fracture.