Thermal failure of the LM117 regulator under harsh space thermal environments

In the past decades, the dramatic increase on the reliability importance of electronic systems for space applications has led to greater scrutiny of these devices for these applications, especially as reliability relates to temperature. Component failure is strongly dependent on the temperature at which the device operates. This also applies to components, electronic parts, such as diodes, resistors and capacitors. These components when used in space applications must endure the harsh thermal loads caused by space thermal environments. These thermal loads cause electronic systems to fail through such mechanisms as crack propagation of solder joints, the fracturing of mechanical joints or electric malfunction. s study, a thermal failure of a transponder unit in the Korea LEO (Low-Earth Orbit) Earth Observation satellite will be discussed. This thermal failure occurred in an LM117 regulator used as a microcircuit of the transponder unit during a space thermal environment test. The thermal design, analysis and test are discussed in regards to the thermal failure of the LM117 regulator.