Hardness Assurance Guidelines for Moderate Neutron Environment Effects in Bipolar Transistors and Integrated Circuits

This paper sets forth procedures which provide effective means of obtaining semiconductor devices whose neutron-induced response is within known, acceptable limits. These Hardness Assurance (HA) procedures can be applied to bipolar transistors, TTL (54/74 series) digital integrated circuits, and operational amplifiers (such as the 741). HA is implemented by imposing two control levels on the supplier and/or two quality levels on the user. The supplier controls include process controls, 100% nondegrading screens, and lot sample radiation tests. The user chooses the minimum number of HA controls necessary to obtain a population proportion of 80% or better. The reason for choosing the 80% point is based upon lot sample statistics and a sample size of 10 units. These HA procedures for the supplier and the user, together with a lot sample statistical plan based on one-sided tolerance limit factors and part selection based on a 10x radiation overtest, yield an estimate of minimum lot quality at low test cost.