A Capacitive Pressure Sensor Based on LTCC/PDMS Bonding Technology

Due to good chemical, electrical and mechanical properties, Low Temperature Co-Fired Ceramic (LTCC) and Polydimethylsiloxane (PDMS) has shown great potential in microelectronic applications. One of the most promising directions of LTCC technology development are integrating and packing sensors. In this paper, a wireless passive capacitive pressure sensor operating in the MHz range based on LTCC/PDMS materials with bonding technology are proposed, and the design and simulation of the sensor is demonstrated and discussed with the aid of Finite element methods (FEM). It consists of a circular spiral inductor and a capacitor of two electrodes separated by a PDMS media. Furthermore, a unique bonding process of LTCC/PDMS materials to avoid deformation of the capacitive embedded cavity during lamination or sintering is introduced. The FEM simulation result shows that this novel sensor has high sensitivity of 6.88 kHz/kPa and measured range of 0 to 800 kPa.