Life characteristics of some typical semi-conductor devices

Evidence from life tests of transistors is presented as an indication to equipment designers of the changes in electrical characteristics which may occur during the use of these devices. The effects of physical tests such as those for storage at high and low temperatures, high humidity, vibration and shock are also reviewed, and an indication is given of the incidence of inoperative failures. Operational reports of some equipments using large numbers of semi-conductor devices are compared with laboratory life test evidence.