Embodiments relate generally to an ultrasonic detector, and methods of making the ultrasonic detector. The ultrasonic detector may comprise a piezoelectric element operable to convert the pressure of sound waves from mechanical energy into electric signal; a protective cover; a hot melt adhesive; one or more layers of solder; one or more perforated metal electrodes comprising openings filled with the solder; and one or more support elements. The ultrasonic detector may also comprise one or more casing elements operable to enclose and house the other elements of the ultrasonic detector; a printed circuit board (PCB) operable to receive ultrasonic data from the piezoelectric element and electrodes, wherein the electrodes connect to, or contact, the PCB; and an insulator located in proximity to the electrodes, and operable to prevent shorting between the metal electrodes and the metal casing elements.