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Nano Phase Fabrication of Copper Glass Ceramic Composite in Cordierite Substrates

IP.com Disclosure Number: IPCOM000105699D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Brady, MJ: AUTHOR [+4]

Abstract

Cordierite is a compound in the magnesia-alumina system that has the composition Mg sub 2 Al sub 4 Si sub 5 O sub 18 . It is refractory and requires temperatures greater than 1400ºC to sinter. Glass Ceramics (GCs) made from cordierite-like compositions with oxide fluxes can be fired to high density at temperatures less than 1000ºC and can be cofired with a high conductivity metallic conductor such as copper, thus cordierite-type glass ceramics with copper metallurgy are useful in electronic packaging applications. Key to the improvement of the performance properties (electrical conductivity & CTE) of the materials in the composite is fine-scale microstructural control during the early stages of fabrication.

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Nano Phase Fabrication of Copper Glass Ceramic Composite in Cordierite Substrates

Cordierite is a compound in the magnesia-alumina system that has the
composition  Mg sub 2 Al sub 4 Si sub 5 O sub 18 .  It is refractory
and requires temperatures greater than 1400ºC to sinter.  Glass
Ceramics (GCs) made from cordierite-like compositions with oxide
fluxes can be fired to high density at temperatures less than
1000ºC and can be cofired with a high conductivity metallic
conductor such as copper, thus cordierite-type glass ceramics with
copper metallurgy are useful in electronic packaging applications.
Key to the improvement of the performance properties (electrical
conductivity & CTE) of the materials in the composite is fine-scale
microstructural control during the early stages of fabrication.  A
limitation in the conventional approach to fabrication of the glass
ceramic module is the particle size of the metal (Cu) mixed with the
glass in the composite  material matrix.  This limitation impacts the
sintering behavior, since sintering is critically dependent on the
size, packing and distribution of the particles in the green
(unfired) matrix.  An ideal microstructure would consist of metal
particles filling the interstitial voids between larger glass
particles in a close-packed array like atoms in a crystal.  If such
structures could be produced, their sintering behavior would be
highly controlled and predictable.  In practice, the procedure for
packing particles in ordered arrays is still a problem.

           Disclosed is a method for improving the optimization of
the electrical conductivity and CTE of the composite in a glass
ceramic substrate by decreasing the particle size of the conductor
(copper), thus allowing higher glass loadings and better thermal
matching (lo...