Piezoresistive Stress Sensors for In-Situ Monitoring of Wafer Bumping

IME researchers have developed novel piezoresistive sensors for real-time in-situ monitoring of the stress-induced defects during wafer bumping process. A data acquisition system for in-situ monitoring of test chip sensor resistance data during drop impact test has also been developed. The stress data acquired by the piezoresistive stress sensor technique provided fundamental insights for process selection, device reliability and fabrication yield, particularly during wafer bumping handling to meet the needs of reliable packaging.
Xiaowu Zhang et. al., “Application of Piezoresistive Stress Sensor in Wafer Bumping and Drop Impact Test of Embedded Ultra Thin Device," IEEE Transactions on Components, Packaging and Manufacturing Technology, Vol. 2, Iss 6, Pg 935 - 943, Jun 2012