A vibration element includes a base and a vibrating arm extending from the base. The vibrating arm includes an arm positioned between the base and a weight. A weight film is disposed on the weight. The weight has a first principal surface and a second principal surface in a front and back relationship with respect to a center plane of the arm. A center of gravity of the weight is located between the first principal surface and the center plane of the arm. A center of gravity of the weight film is located between the second principal surface and the center plane of the arm.

A method for manufacturing a vibration element including a first protective film formation step of forming a first protective film, a first dry etching step of performing dry etching via the first protective film to form first grooves and the outer shapes of vibrating arms, a second protective film formation step of forming a second protective film in the first grooves, a second dry etching step of performing dry etching via the second protective film, a third protective film formation step of forming a third protective film, a third dry etching step of performing dry etching via the third protective film to form second grooves and the outer shapes of the vibrating arms, a fourth protective film formation step of forming a fourth protective film in the second grooves, and a fourth dry etching step of performing dry etching via the fourth protective film.

A method for manufacturing a vibration element includes, a base film forming step of forming a first base film at a first substrate surface of a quartz crystal substrate in first and second vibrating arm forming regions, a protective film forming step of forming a first protective film in a bank portion forming region of the first base film, and a dry-etching step of dry-etching the quartz crystal substrate through the first base film and the first protective film.

Provided is a method for manufacturing a vibrator element including a first vibration arm and a second vibration arm that each have a first surface and a second surface. The manufacturing method includes a preparation step of preparing a quartz crystal substrate, a first protective film forming step of forming a first protective film on a first substrate surface of the quartz crystal substrate, a first dry etching step of dry etching the quartz crystal substrate via the first protective film, a second protective film forming step of forming a second protective film on a second substrate surface of the quartz crystal substrate, and a second dry etching step of dry etching the quartz crystal substrate via the second protective film. Outer shapes of the first vibration arm and the second vibration arm are formed from the first surface to the second surface in the first dry etching step, and the outer shapes of the first vibration arm and the second vibration arm are not formed in the second dry etching step.

A vibration element manufacturing method includes a first dry etching step of dry-etching a quartz crystal substrate from the first surface side to form first grooves and the outer shapes of first and second vibrating arms, a second dry etching step of dry-etching the quartz crystal substrate from the second surface side to form second grooves and the outer shapes, and a wet etching step of wet-etching the side surfaces of the first and second vibrating arms, the first grooves, and the second grooves to form inclining surfaces that couple bottom surfaces to in-groove side surfaces of the first and second grooves, and the first and second grooves satisfy the relationship of D1/D 0.80, where D represents the depth of each of the first and second grooves, and D1 represents the result of subtraction of the length of the inclining surfaces in a direction Z from the depth in each of the first and second grooves.

A method for manufacturing a vibration element includes, a first base film forming step of forming a first base film at a first substrate surface of a quartz crystal substrate in first and second vibrating arm forming regions, a first protective film forming step of forming a first protective film in a first bank portion forming region of the first base film, a first dry-etching step of dry-etching the quartz crystal substrate through the first base film and the first protective film, a second base film forming step of forming a second base film at a second substrate surface of the quartz crystal substrate in the first and second vibrating arm forming regions, a second protective film forming step of forming a second protective film in a second bank portion forming region of the second base film, and a second dry-etching step of dry-etching the quartz crystal substrate through the second base film and the second protective film.

A vibrating arm of a vibrator element has a first surface, a second surface at an opposite side to the first surface in a Z direction, a first side surface and a second side surface as side surfaces, and a third side surface as a tip surface. At least one of the first side surface, the second side surface, and the third side surface includes a first side surface part tilted with respect to a Z direction, and a second side surface part tilted toward the first surface or the second surface with respect to the first side surface part. The first weight is arranged so that an outer edge of the first weight is located at inner side of innermost parts in the first side surface part and the second side surface part, or at the same position as the innermost parts when viewed from the Z direction.