Test Temperature Calibration Using Inertial MEMS Voltage-Temperature Characteristics for ATE Setup

Abstract

In the chip-scale package final test, temperature is one of the main components as this is also indicated on once specification on electrical parameters that are temperature sensitive especially for inertial Micro-Electro- Mechanical Systems (MEMS) accelerometers. The voltagetemperature relationship of an accelerometer has been presented and used to calibrate test temperature on Automated Test Equipment (ATE) setup. Bench reference data of a set of units were gathered to correlate with the Device under Test (DUT) temperature with the raw ATE handler test temperature using linear regression. Offset test temperature or the temperature error was calculated across all sites to adjust the new ATE handler test temperature. After which, the correlation between the bench reference data and the gathered ATE data of the 20 golden units from two test flows with 2.3 seconds and 200 milliseconds respectively both with 4-site enabled testing was validated that all DUT temperature is within acceptable temperature window of +/- 3°C, also less standard deviation for longer test time by only 0.0011 and all 20 golden units passed for both test flows. Lastly, the comparison of the newly calibrated test handler using the voltage-temperature relationship which had 0.0011, 0.0011, and 0.0012 SD of data, and the static calibrated test handlers which had 0.0057, 0.0078, and 0.010 SD of data for each lot 1, 2, and 3 respectively show up to 8x improvement in SD of the DUT temperature in ATE.