Enhanced polymeric encapsulation for MEMS based multi sensors for fisheries research

This paper presents the challenges of a packaged MEMS-based multi sensor system that allow for direct exposure of the sensing part to sea water. The system is part of a data storage tag used on fish to provide the researcher with information on fish behaviour and migration. The sensor measures light intensity, temperature, pressure and conductivity. For precise and fast measurements a direct exposure of the sensor to the water is desirable. A potted tube encapsulation concept has shown to be promising for accurate and fast measurements in harsh environment, provided a tight sealing of the electronics can be made. In this paper we investigate the interfacial delamination of an epoxy encapsulated chip. Differently prepared silicon chips are investigated and it is found that silicon dioxide surfaces functionalised with (3-aminopropyl) triethoxysilane will improve this encapsulation approach compared to low pressure chemical vapor deposited (LPCVD) silicon nitride and untreated silicon dioxide.