Experimental investigation and interpretation of the real time, in situ stress measurement during transfer molding using the piezoresistive stress chips

This paper describes a method used for experimental real-time monitoring of thermo-mechanical stress build-up during integrated circuit encapsulation. To detect the stress variations during molding, special stress measuring chips were employed. The working principle of the stress chip is based on the piezoresistive sensors embedded on the surface in a 6 by 6 matrix distribution. [1