Parameters affecting the sensitivity of LTCC pressure sensors

Abstract

Purpose - The purpose of this paper is to demonstrate the influence of material properties and fabrication technique on the performance of an embedded pressure sensor. Based on conducted theoretical analysis a suitable material and technological technique that gave the best behavior of designed sensor was chosen for its fabrication. This is verified on the example of a resonant pressure sensor, designed for operation in the MHz range. Design/methodology/ approach - A sensor module is fabricated using the low temperature co-fired ceramics (LTCC) technology and sputtering technique for electrodes deposition. Themodule comprises an inductor connected with a variable capacitor formed by the sensor membranes in a parallel LC circuit. An extensive parallel analysis of sensors performance for sensors with thick film (screen-printed) and thin film (sputtered) electrodes is demonstrated. Mechanical and electrical parameters (Young's modulus and permittivity) of different tape materials that are considered for sensor fabrication are determined at room temperature. Findings - Implementation of the sputtering technique for deposition of the thin film electrodes and usage of tapes with higher elasticity significantly contribute to the increase of the sensor performance (improved sensitivity) compared to designs found in available literature. Experimentally attained results are compared with the ones obtained by analytical calculationsachieving good agreement of obtained results. Originality/value - Theimprovement of sensor sensitivity by means of evaluation of differenttape material and electrode thickness reduction is demonstrated for the first time. The presented results of the sensor equivalent model and the sensor-antenna system are in good compliance with experimentaldata determined through measurement. © Emerald Group Publishing Limited.