Advanced Thin-Film Ignitor Resistors Hasten Airbag Deployment

A series of advanced thin film resistors has been designed for the latest generation of "intelligent ignitors" in vehicle airbag and seat-belt pre-tensioning systems. With the new surface-mount resistor chips, automotive system design engineers have a precise and reliable electronic means of triggering airbag ignition within 100 µs. The resistor chips combine the stability of self-passivating TaNFilm tantalum nitride thin film technology with the precision of the fine-line photolithography techniques to provide this ultra-fast inflation. The process creates an extremely small resistor "bridge," placing the source of ignition in intimate contact with the pyrotechnic material used to initiate inflation. Ignition occurs ten times faster and with less input energy than conventional wire ignitors. The ignitor chip achieves ignition temperature using less than 100 microjoules of energy supplied by an on-board capacitor and exhibits superior performance in Bruceton testing. The ignitor resistors have resistance values from 2 ohms to 10 ohms and are available in two standard sizes, 0603 and 0805, on high-grade alumina ceramic substrates with wrap-around gold-plated solder terminations. Silicon die designed for high-reliability wire terminations is also available.