Packaged pressure sensor device and corresponding method for detecting the presence of foreign material

A method, comprising:

• detecting foreign material with a pressure sensor device, the pressure sensor device including:
• a first die including:
• a pressure detection structure;
• and
• a piezoelectric transduction structure of an ultrasonic type;
• a package contains the first die, the package including a base structure and a body structure on the base structure, the package having an access opening in fluid communication with an external environment and internally defining a housing cavity in which the first die is arranged and in which the first die is covered with a coating material,
• wherein detecting the foreign material with the pressure sensor device includes:
• determining the presence of the foreign material over the coating material and within the package, determining the presence of the foreign material over the coating material and within the package including:
• generating ultrasounds detection acoustic waves with the piezoelectric transduction structure;
• and
• processing an electrical signal detected through the piezoelectric transduction structure due to an echo associated with a reflection of the detection acoustic waves.

A device, comprising:

• a base structure including a surface;
• a body structure coupled on the surface of the base structure, the body structure includes an access opening;
• a housing cavity defined by the base structure and the body structure;
• a first die within the housing cavity and on the surface of the base structure;
• a second die within the housing cavity and stacked on the second die, the second die including:
• a piezoelectric detection structure;
• and
• a piezoelectric transduction structure;
• a coating material in the housing cavity covers the first die and covers the second die, the coating material including a surface exposed by the access opening.