Calculate Failure Rates Research Articles

Reliability evaluation of plastic encapsulated parts

This work compares the failure rates of several families of plastic encapsulated microcircuits (PEMs) using both field and test data (test data are converted to device failure rates for field conditions using common acceleration equations) and Mil-Hdbk-217 calculations. Calculated failure rates are obtained from the Mil-Hdbk-217F for both plastic encapsulated and ceramic hermetic class-B microcircuits. Comparisons show that the results from Mil-Hdbk-217 are misleading and that the US military and Government part-selection methods should not be burdened by this -217 methodology. >

Estimated Failure Rates for Some Selected Tritium System Components

Fusion facility safety and reliability/availability analyses require accurate component failure rate information to provide meaningful results. While fission reactor operating experience data may be adequate for some types of components, there are some data needs that are fusion-specific, such as tritium fueling and handling system information. This paper summarizes the results of a failure data analysis task on several components at Los Alamos National Laboratory’s Tritium Systems Test Assembly (TSTA). We took the failure reports and component operating information from the TSTA Failure/Maintenance Data Base. Calculated failure rates are on the same order of magnitude as screening fusion failure rate data, although a few failure rates were slightly higher. These new data should be of interest to fusion safety analysts and tritium systems designers.

Reliability of Complementary MOS Integrated Circuits

This paper describes the results of tests of the stability and reliability of complementary MOS (CMOS) integrated circuits (IC). Operating life-tests at 125°C indicated excellent stability of electrical characteristics of both n-channel and p-channel transistors. Over three million device-hours of accelerated operating life-tests indicated a calculated failure rate, at a 60-percent s-confidence level, of 0.08%/1000 hours at 125°C, which corresponds to 0.01%/1000 hours at 55°C or 0.003%/1000 hours at 25°C. Field-usage reliability data on three satellites in orbit indicate a total failure rate of 0.003%/1000 hours (over thirty-four million operating hours with no failures). The observed failure rates are compared with other available data on IC reliability, and it is concluded that the reliability of CMOS ICs is equal to that of p-channel MOS circuits or of bipolar digital circuits of equal complexity, when each type is prepared by a well-controlled process, and operated at the same temperature. The operating temperature of CMOS IC chips in electronic systems is, however, generally lower since logic functions are accomplished at lower dissipation per gate.