Resonator element, resonator, resonator device, oscillator, electronic device, and mobile object

A resonator element comprising:

• a quartz crystal substrate having:
• an X-axis as an axis of rotation, the X-axis being of an orthogonal coordinate system constituted by the X-axis as an electrical axis, a Y-axis as a mechanical axis, and a Z-axis as an optical axis which are crystal axes of a quartz crystal,
• a Z′ axis obtained by inclining the Z-axis so that a +Z side rotates in a −Y direction of the Y-axis,
• a Y′ axis obtained by inclining the Y-axis so that a +Y side rotates in a +Z direction of the Z-axis,
• a main surface along a plane including the X-axis and the Z′-axis, and
• a thickness in a direction along the Y′-axis,
• wherein the quartz crystal substrate includes:
• a vibrating portion including a side along the X-axis and a side along the Z′-axis, and
• a peripheral portion provided along an outer edge of the vibrating portion, the peripheral portion having a thickness that is smaller than that of the vibrating portion,
• wherein the vibrating portion includes:
• a first portion,
• a second portion provided on at least an outer edge on a +X side of the X-axis and an outer edge on a −X side of the X-axis, among outer edges of the first portion, the second portion having a thickness that is smaller than that of the first portion, and
• a convex portion protruding in a +Y′ direction of the Y′-axis further than the peripheral portion,
• wherein Z is a length of the quartz crystal substrate along the Z′-axis, t is a thickness of the first portion, and 11<Z/t≦53,
• wherein the convex portion includes one lateral side including a surface which intersects the Z′-axis and is inclined with respect to a plane including the X-axis and the Z′-axis, the other lateral side including a surface which intersects the Z′-axis and is perpendicular to the plane including the X-axis and the Z′-axis, and a planar portion which is interposed between the one lateral side and the other lateral side, and
• wherein when seen in a plan view, Sz is a length of the one lateral side along the Z′-axis, Mz is a length of the planar portion along the Z′-axis, and 0≦Sz/Mz≦0.05.