Finite element modelling of influence of bonding material distribution in precision piezoresistive MEMS pressure-sensors

A MEMS pressure-sensor, including its vacuum reference cavity, is modelled with focus on resulting stress from a glass frit bonding process. Based on CT-scans of bonded samples, a parametric model for FEM analysis of observed variations in bonding material distribution has been developed. Simulations show a high influence of amount and distribution of excess glass frit material on the zero-point as well as a good correlation with manufacturing data. Simulated variations of glass frit material distribution shows a variation of the zero-point of -1.5 % full scale (FS) to -7.2 %FS, depending on configuration.