Fraunhofer Institute for Electronic Nano Systems
Micromachined ultrasound transducers, including CMUT, are usually fragile and sensitive to external loading conditions. Exposure to mechanical stress could result in the variation of the operating range or damage to the transducer. The design of the package as well as the selection and integration of the encapsulation material for transducers such as CMUT are crucial for the packaging of the ultrasonic transducers. Fraunhofer ENAS has developed packaging and encapsulation solutions suitable for different applications. The transducers have been developed with a planar polymer encapsulation suitable for non-destructive testing, imaging and other sensing applications. Encapsulant material and dimensions are chosen to minimize the impact on acoustic performance. In addition, transducer packaging with a suitable acoustic window has been developed at Fraunhofer ENAS for extreme operation conditions such as elevated temperatures (e.g., 200 °C).