Capacitive Micromachined Ultrasonic Transducers Leak Detection By Dye Penetrant Test

Dye penetrant test has been used to detect non hermetic capacitive micromachined ultrasonic transducers (CMUTs). The method has proven its ability to highlight faulty CMUTs membranes among more than hundreds of CMUTs membranes. The fluorescence microscopy image highlights the defective CMUTs with a strong contrast and respecting the shape of the CMUTs, which makes it possible to design robust faulty CMUT automatic identification algorithms. Scanning electron microscopy has been performed in order to check the reliability the detection of the non-hermetic CMUTs. Observations confirmed the reliability of the method.