ELECTRICALLY CONDUCTING POWDER FILLED POLYIMIDESILOXANE

Electrically conducting powders (nickel, silver and graphite) were used as fillers in polyimidesiloxane to form polymer-matrix composites with low electrical resistivity and low thermal expansion. Nickel particles of size 1-5-mu-m provided composites of electrical resistivity almost as low as that provided by silver particles. Furthermore, nickel-filled composites had superior electromagnetic interference shielding effectiveness, lower thermal expansion and superior mechanical properties, which were attained at 40 weight % Ni. Nickel particles of size 78-127-mu-m were far less effective than those of size 1-5-mu-m. These composites may be used in electronic packaging.