Life Test and Modeling for Carbon Film Fixed Resistor Under Escalated Voltage Stress

The endurance of the electronic component under an overstress situation is important for the reliability and safety of electronic systems. Failure, and even catastrophic disaster, can occur when voltage overstress last a certain period. This article investigates the thermal and electrical change in resistors under overstressed voltage. The carbon film fixed resistor is taken as an example. Through a specifically designed test board, the current and thermal change over time are measured. A thermo-dynamic model regarding temperature and time is developed, and the life of the resistor is derived from this model. Results find that for the selected five voltage stresses, the thermo-dynamic model agrees with the experimental measurements to a high degree. The life model finds that the life of the resistor is proportional to the square of the voltage stress. Additionally, the life exhibits randomness and can be fit by a Weibull distribution. Moreover, it finds that during the burning course, the peak temperature of the resistor can be as high as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$350~^{\circ }$ </tex-math></inline-formula>C, and the resistance always decreases with time for lower overstress levels.