IC Failure Rate Estimates from Field Data

An estimate of the field failure rate for transistor-transistor-logic (TTL) integrated circuit electronic components was obtained by monitoring the field operation of a clinical chemistry diagnostic system over a period of seven years. The utility of the field data resulting from system monitoring lies in a well-defined instrument operating profile and maintenance reporting system. The array of TTL components used in the instrument represents small- and medium-scale integration complexity. The components operate in a laboratory environment. Based upon 636 million component operating hours, the TTL integrated circuit field failure rate estimate is 0.016 percent per thousand hours.