Packaging structure design for metal oxide gas sensors

For gas-sensing mechanism of metal oxide, metal oxide gas sensor chip needs to work in a hot environment from 150°C to 400°C and must open to detected gases. These different characteristics, compared with integrated circuit (IC), lead significant challenges for metal oxide gas sensor packaging design. In this paper, to get best packaging design, we discuss the influence of the sensor chip conductivity(A), shell conductivity(B), metal wire conductivity(C), glass insulation conductivity(D), sensor chip size(E), source power(F) and shell thickness(G) on the gas sensor package thermal performance by modeling and finite element analysis(FEA) method, and then verify the FEA method though an experiment. The results show that the influence to the mean temperature of the shell top center decreases in the order: F>B>C>E>D>A>G according to the R values, while the influence to the sensor chip temperature decreases in the following order: C>D>B>E>F>A>G.