In order to improve the reliability of down-hole electronics, Quartzdyne Electronics has invested millions of device test hours in life testing circuits in both powered and un-powered modes. In addition to time at temperature, these tests include thermal cycling and high impact drop testing. Resistors drift has become a significant wear-out mechanism in these tests. Prior testing has shown that resistor material, substrate material, resistance range and trim method each play a significant role in resistor stability at elevated temperatures. Some resistance ranges tested had no acceptable performers.
The purpose of this study is to expand the range of values, materials and package sizes in hopes of identifying reliable resistors for high temperature applications. This study will focus on a broad range of NiCr-on-silicon resistors, including larger package sizes than were previously tested. Additionally, we will be testing several precision foil-type resistors. Resistors will be mounted in hermetic packages and aged at 285°C for 1000 hours. The packages will be removed from the oven periodically and the resistance of the devices will be measured at ambient temperature. This study is being done in cooperation with resistor vendors who have supplied some of the devices for this test.
Reliability life-testing and failure-analysis of GaAs monolithic Ku-band driver amplifiers