Ultrasonic sensing apparatus

An ultrasonic sensing apparatus, comprising:

• an accommodating shell, comprising a base and a convex portion connected to the base, wherein a side of the base has a first detection opening toward a first direction, and a side of the convex portion has a second detection opening toward a second direction;
• and
• at least one detection device, wherein each of the at least one detection device is disposed in the base or the convex portion of the accommodating shell and comprises:
• a board, disposed in the accommodating shell and covering the first detection opening or the second detection opening;
• a piezoelectric assembly, comprising an encapsulating body and a piezoelectric sheet, wherein at least a portion of the piezoelectric sheet is enclosed by the encapsulating body, the encapsulating body is disposed on the board, and the piezoelectric sheet has a sensing surface exposed to the encapsulating body and away from the board;
• a housing, comprising a top wall, a bottom wall and a surrounding side wall connected between the top wall and the bottom wall and surrounding the encapsulating body, wherein the top wall has an opening formed at the position where the top wall is connected with the surrounding side wall and opposite to the bottom wall, and the top wall is disposed on the board, so that at least the bottom wall of the housing is exposed to the first detection opening or the second detection opening;
• and
• a plurality of fixing members, configured to fix the board on the top wall of the housing to press the board to the encapsulating body of the piezoelectric assembly, thereby pressing the sensing surface of the piezoelectric sheet to the bottom wall.