Study on optimization of capacitive pressure sensor using coupled mechanical-electric analysis

The object of the paper is a pressure sensor realized in thick-film technology developed at ldquoJozef Stefanrdquo Institute. This pressure sensor is also the object of a common project which has the goal to optimize the sensor design acting mainly on layout parameters. Some of the sensor parameters are determined by the LTCC process, for instance the thickness of diaphragm whose thickness is a multiple of foil thickness. The novelty in the proposed paper is the use of specific simulation tools to give an estimate of sensor output characteristics. Using this technique it is possible to optimize the layout and construction of the sensor. The finite-element simulation is used to outline the output characteristic: capacitance versus pressure. This simulation implies the coupled field analysis from mechanical deflection of sensor diaphragm to electrical field quantities, in this case the capacitance. The analysis will take into account beside geometrical parameters the temperature dependence of materials properties. This fact will give a better appreciation of real life behavior of manufactured sensors, and can suggest some specific packaging methods.