Ta-SiC Thin Film Resistors for Highly Reliable Thermal Printing Heads

A Ta-SiC thin film resistor has been newly developed for highly reliable thermal printing heads. The Ta-SiC film, which is formed by a sputtering technique, has a stable amorphous structure containing microcrystalline Tac. The film crystallization hardly develops, even at temperatures up to 800°C. In addition to this structural stability, it has chemical stability and oxidation resistance. A thermal printing element test piece has been fabricated composed of a 17 at% Ta-SiC heating resistor, Al conductor, and a sputtered SiC surface protective layer on a g!azed alumina substrate. High temperature resistor annealing and alkaline metal- and lead-free glaze substrate adoption are effective for stability improvement. As a result, highly reliable high speed thermal printing elements were realized, Which could generate more than 5 x 10⁸heatpulses at above 500°C peak temperature with 0.5-2.0 ms short electric current pulses.