Development of a mechanical stress-analysing-tool to characterize packaging processes

This paper reports on the development of a measurement system to detect mechanical stress caused by packaging processes. A piezoresistive silicon test chip is used to convert the inducted mechanical stress into a resistance change, measured by a developed resistance analyser. The sensor interface is capable to measure a high number of resistors with a high measurement rate. Thus, also rapid proceeding packaging processes can be characterized. Furthermore, the developed software calculates the stress distribution along the whole die, which includes a compensation of the systematic errors e.g. the temperature dependence of the piezoresistive coefficients.