Analysis of the Packaging Stresses in Monolithic Multi-Sensor

A monolithic multi-sensor for absolute pressure, temperature and humidity is packaged by the packaging structure of chip on board (COB). To investigate the packaging effect of the multi-sensor, the finite element method (FEM) is adopted for analyzing the packaging stress in the multi-sensor chip introduced by the mismatch of the thermal expansion coefficients (TCE) in the different materials. The simulation result shows that the packaging effect of the absolute pressure sensor can be reduced by increasing the thickness of adhesive layer, the fillet height of the adhesive and decreasing the Young´s modulus of the adhesive, but the effect of the package-induced thermal stress can be neglected in the temperature sensor and humidity sensor. The experiment of the packaged monolithic multi-sensor confirms the result of FEM simulation.