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.

There are provided an excitation electrode, a quartz crystal vibrator element, a quartz crystal vibrator, a sensor, an oscillator, and a method of manufacturing a quartz crystal vibrator element which are not affected by heat in a process or a use environment to surely prevent a frequency fluctuation from occurring, reduction in size of which can be achieved, and which are low in cost and excellent in productivity. The excitation electrodes are disposed on an outer surface of a quartz crystal plate, apply an electrical field for exciting the quartz crystal plate to the quartz crystal plate, have a single layer structure formed of a two-dimensional layered substance, and are used when arranged as a pair so as to be opposed to each other via the quartz crystal plate.

A method for manufacturing a vibrator element includes a first protective film forming step of forming a first protective film on a first substrate surface of a quartz crystal substrate, a first dry etching step of dry etching the quartz crystal substrate from a first substrate surface side to form a first groove and outer shapes of a first and second vibration arms, 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 from a second substrate surface side to form a second groove and outer shapes of the first and second vibration arms. In the first dry etching step, the outer shapes of the first and second vibration arms are formed to be closer to the second substrate surface than is a position where a bottom surface of the second groove is formed.

To improve durability against impact, a quartz crystal resonator element includes a recess in a plan view. The quartz crystal resonator element further includes a first principal surface and a second principal surface that are front and rear surfaces facing away from each other and a side surface disposed between the first principal surface and the second principal surface, and the side surface is formed of flat surfaces and curved surfaces formed by dry etching and alternately arranged. The quartz crystal resonator element preferably has a base and at least one resonating arm extending from the base.

A vibrator (electronic device) includes: a vibrator element including vibrating arms; a base portion supporting the vibrator element and having a rectangular shape in a plan view; and a lid provided on the side of the vibrator element opposite to the base portion 3. Extending directions of long and short sides of the base portion and an extending direction of the vibrating arms cross each other. When an angle formed by the vibrating arms and a Y-axis direction is θ, the angle θ is more than 0° and less than 90°.

A crystal vibrator includes an AT-cut crystal substrate with a vibration portion having a principal surface and a peripheral portion surrounding and thinner than the vibration portion. An excitation electrode is formed on the principal surface and an extension electrode is electrically connected to the excitation electrode. The vibration portion has a first short-edge side lateral surface that abuts the peripheral portion at an acute angle and a tapered lateral surface adjacent to the first short-edge side lateral surface and inclined with respect to the X axis in the XZ′ plane. The tapered lateral surface abuts the peripheral portion at an angle that is greater than the angle defined by the first short-edge side lateral surface. The extension electrode extends from the excitation electrode through the tapered lateral surface to a first short-edge side in a longitudinal direction parallel to the Z′ axis.

Provided is a method for bonding wafers, which can bond the wafers to each other with high reliability while reducing the influence on the wafers. The method for bonding wafers includes the steps of: preparing a first wafer that has, on the surface thereof, a first metal layer with a first rigidity modulus, and a second wafer that has, on the surface thereof, a second metal layer with a second rigidity modulus higher than the first rigidity modulus; removing an oxide film at the surface of the second metal layer while an oxide film at the surface of the first metal layer is not removed; and bonding the surface of the first wafer to the surface of the second wafer.

A method of manufacturing a piezoelectric resonator unit that includes preparing a piezoelectric resonator having a piezoelectric element, a pair of excitation electrodes respectively disposed on a first main surface and a second main surface of the piezoelectric element so as to face each other with the piezoelectric element therebetween, and a pair of connection electrodes that are respectively electrically connected to the pair of excitation electrodes; electrically connecting the pair of connection electrodes to a pair of electrode pads on a third main surface of a base member using an electroconductive holding member so as to excitably hold the piezoelectric resonator on the third main surface of the base member; and attaching an electroconductive material, which is scattered from an electroconductive member, to a surface of the electroconductive holding member.

A manufacturing method for an electronic component that includes a providing a base member on a first main surface of a first board, sandwiching the base member and a joining member paste between the first main surface of the first board and a transfer main surface of a transfer board, forming a joining member joined with the base member while the joining member paste is sandwiched by the first board and the transfer board, and peeling off the transfer board from the joining member joined with the base member.

A method for manufacturing a vibration element including first and second vibrating arms each having a first surface and a second surface that are front and rear sides with respect to each other and a bottomed groove that opens via the first surface, the method 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 grooves and the outer shapes of the first and second vibrating arms, a second protective film formation step of forming a second protective film in the grooves, and a second dry etching step of performing dry etching via the second protective film to form the first surface and the outer shapes of the first and second vibrating arms.