Differential pressure sensors have two process connections. They determine the pressure difference between the connections, which are separated by a membrane. These sensors are preferably used for volume flow measurement.
In classic silicon-based pressure sensors for process technology, the silicon element is protected from the process media by oil in front of a separating membrane. If the separating membrane breaks, the oil can contaminate the food. At very low temperatures and in the food industry, this application is risky. However, without this oil layer, safe passivation of the silicon element on all sides, including the electrical contacts, is not possible.
A solution is therefore being sought that allows wet-wet media contact on both sides and guarantees long-term stability of the measurement signal. The basis for this are silicon strain sensors (Si-DMS), which are completely and electrically contacted and embedded in a media-resistant lead-free ceramic.
The aim of the new “DMS in ceramics” project is to develop a process for a differential pressure sensor with a media-resistant ceramic bending plate and integrated Si strain gauge. By fully integrating the Si strain gauge during the lamination of the Low Temperature Co-fired Ceramics (LTCC), it is hermetically sealed and protected against mechanical manipulation.
The research and development work described was funded by the Federal Ministry of Economic Affairs and Climate Action (BMWK) as part of the “DMS in ceramics” research project.
Funding code: 49MF 230066
