Piezoelectric resonator plate and piezoelectric resonator device

A piezoelectric resonator plate having a rectangular shape, comprising:

• a first excitation electrode formed on a first main surface of a substrate;
• and a second excitation electrode formed on a second main surface of the substrate, the second excitation electrode making a pair with the first excitation electrode, wherein
• the piezoelectric resonator plate further includes:
• a vibrating part having a rectangular shape;
• an external frame part surrounding an outer periphery of the vibrating part;
• at least one support part connecting a part of the vibrating part to a part of the external frame part;
• and a cutout part formed by cutting out the substrate such that the cutout part is interposed between the vibrating part and the external frame part,
• an electrode formed on the first main surface of the substrate is electrically connected to an electrode formed on the second main surface of the substrate via an internal wiring formed on an inner wall surface of the external frame part, and
• in a space of the cutout part, when a first area represents an area sandwiched between the inner wall surface of the external frame part and an outer wall surface of the vibrating part, and when, in a remaining space of the cutout part except the first area, a second area represents an area sandwiched between the inner wall surface of the external frame part and an outer wall surface of the at least one support part and furthermore a third area represents an area sandwiched between two parts of the inner wall surface of the external frame part, the internal wiring is formed on the inner wall surface of the external frame part, at a position facing at least one of the second area and the third area.