Patent ID: 7964542

Claim:
A liquid composition for use as a heat transfer interface in electronic testing such as burn-in testing and microelectronic assembly, having an enhanced thermo-oxidative stability for extended periods at elevated temperatures consisting essentially of: a liquid comprising polyalphaolefin oil; a stability enhancing combination of about 0.16-0.4% by weight of a hindered phenol of [1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene] in combination with about 0.1-0.25% by weight of an aromatic phosphite antioxidant of tris(2,4-di-tert-butyl phenyl)phosphite, wherein a ratio of phenol:phosphite in weight % ranges from about 1:1 to about 2:1; and an aminic antioxidant present in an amount of about 0.05-0.15% by weight in the polyalphaolefin oil.