Irradiation test and preselection of maverick diodes for the project symphonie satellite

Abstract As a result of the general irradiation test for the electronic components of the Project Symphonie satellite one out of ten specimens of the high voltage diode USR-12 suffered catastrophic failure. As a consequence a preselection irradiation procedure with subsequent heat treatment was performed in order to reveal maverick behaviour of individual specimens within the qualification lot. A pretest proved 105 radSi (60Co) as preselection dose and 1 hr at 110°C as heat treatment condition convenient to carry out the preselection procedure and to decide on anormal reverse current behaviour. By means of statistical considerations four specimens were ruled out of the qualification lot of 78 devices. For application means an order of precedence could be established.