Thick film resistive heater compositions comprising Ag and RuO2, and methods of making same

Abstract

Thick film resistor paste compositions, and methods for making the thick film compositions are disclosed. The compositions include a resistor composition dispersed in an organic vehicle. The resistor composition has 3 to 60% by weight RuO2 conductive material, 5 to 75% by weight Ag conductive material, 15 to 60% by weight glass frit and optionally up to 10% by weight copper oxide or precursor thereof, and up to 20% by weight bismuth oxide or precursor thereof. The resistor composition when printed to a dry thickness and fired at a temperature between 750° C. and 950° C. achieves a sheet resistivity between 10 and 10,000 milliohms/square and a hot temperature coefficient of resistivity of 1000 ppm/C or higher. The fired resistor composition may achieve a resistance thickness ratio (Rtr) value between 0.75 and 1.50.

Dependencies are inferred from the claim text.