Ten Years of Power Aging of the Same Group of Submarine Cable Semiconductor Devices

The active devices in the first Bell System transistorized submarine cable system (sf) are unpassivated, diffused-base, germanium transistors and oxide-passivated, silicon diodes. At the date of this writing these devices have accumulated over 550 million device hours of powered operation in service and on the aging rack without failure or impaired device performance for a demonstrated failure rate of less than 0.00045 percent per thousand hours (4.5 fits) with 90-percent confidence. This paper reports details of the behavior of 500 of these devices that have reached ten years of controlled power aging. The overall results indicate that initial reliability objectives are being achieved and that the semiconductor devices should not be expected to limit the desired life span of sf submarine cables.