Method Of Manufacturing Vibration Element

A method of manufacturing a vibration element, the method comprising:

• manufacturing, by wet etching, a piezoelectric substrate including a vibration element, a frame portion, and a coupling portion that couples the frame portion and the vibration element;
• and
• folding the vibration element at the coupling portion and separating the vibration element from the frame portion, wherein
• in the manufacturing of the piezoelectric substrate by the wet etching,
• the coupling portion is formed with a first groove portion, and a first protruding portion and a second protruding portion at one surface of a first surface and a second surface which is in a front and rear relationship with the first surface, the first protruding portion and the second protruding portion being disposed at positions sandwiching the first groove portion and protruding from an outer shape side of the vibration element to which the coupling portion is coupled when viewed from a direction perpendicular to the one surface,
• when viewed from the direction perpendicular to the one surface, the first protruding portion has a first outer shape side that defines an outer shape of the coupling portion and a second outer shape side that defines a boundary between the first protruding portion and the first groove portion, and is formed in a shape in which a distance between the first outer shape side and the second outer shape side decreases as a distance from the outer shape side of the vibration element to which the coupling portion is coupled increases, and the first outer shape side and the second outer shape side are formed to be inclined with respect to the outer shape side of the vibration element to which the coupling portion is coupled, and
• when viewed from the direction perpendicular to the one surface, the second protruding portion has a third outer shape side that defines the outer shape of the coupling portion and a fourth outer shape side that defines a boundary between the second protruding portion and the first groove portion, and is formed in a shape in which a distance between the third outer shape side and the fourth outer shape side decreases as a distance from the outer shape side of the vibration element to which the coupling portion is coupled increases, and the third outer shape side and the fourth outer shape side are formed to be inclined with respect to the outer shape side of the vibration element to which the coupling portion is coupled.