On-chip piezoresistive stress measurement in three directions

Abstract

Abstract A sensor design has been developed and realized in order to determine the mechanical stresses on the surface of a silicon die. The purpose of this sensor chip is to examine the stresses on the surface of the chip caused by chip encapsulation and package temperature-cycle tests. Our approach uses the piezoresistive effect. However, the piezoresistive strain gauges not only measure the in-plane stresses but also the stress perpendicular to the chip surface. In this article we give the outline for the design of our stress sensor and show how this sensor is capable of separating the different mechanical stress components.