Wireless LTCC-based capacitive pressure sensor for harsh environment

• A new square capacitive cavity structure is designed.
• The sacrifice paste is firstly introduced into the LTCC-based MEMS (micro electromechanical system) structure.
• More favorable flatness of the sensor's sensitive membrane is realized.
• Comparing with its predecessors, greater sensitivity of the sensor is presented.

This paper presents a wireless capacitive pressure sensor based on LTCC (low temperature co-fired ceramic) technology, where the design, fabrication, and measurement of the sensor is demonstrated and discussed. Differ from traditional LTCC process flow, a unique process of screen-printing sacrifice layer has been introduced to avoid deformation of the capacitive embedded cavity during lamination or sintering, which leads to a better performance of the sensor. A greater sensitivity of the sensor, comparing with its predecessors, is showed during measurement. Finally ways for future optimization are proposed.