A method for manufacturing a vibration element that includes a base portion, a first vibration arm and a second vibration arm that extend from the base portion along a first direction and are arranged along a second direction intersecting the first direction, and bottomed grooves on both main surfaces of the first vibration arm and both main surfaces of the second vibration arm includes: a preparing step of preparing a crystal substrate; a protective film forming step of forming a protective film on the crystal substrate except for groove regions that are regions in which the grooves are formed; and a dry etching step of dry etching the crystal substrate through the protective film to form the grooves. The grooves provided in at least one of the first vibration arm and the second vibration arm include a first groove and a second groove arranged along the second direction.

A method for manufacturing a vibration element that includes a base portion, a first vibration arm and a second vibration arm that extend from the base portion along a first direction and are arranged along a second direction intersecting the first direction, and bottomed grooves on both main surfaces of the first vibration arm and both main surfaces of the second vibration arm includes: a preparing step of preparing a crystal substrate; a protective film forming step of forming a protective film on the crystal substrate except for groove regions that are regions in which the grooves are formed; and a dry etching step of dry etching the crystal substrate through the protective film to form the grooves. The grooves provided in at least one of the first vibration arm and the second vibration arm include a first groove and a second groove arranged along the second direction.

A method for manufacturing a vibration element includes: a first dry etching step of dry etching the quartz crystal substrate from a first surface and forming first grooves and contours of a first vibrating arm and a second vibrating arm on the first surface; and a second dry etching step of dry etching the quartz crystal substrate from a second surface side and forming second grooves and contours of the first vibrating arm and the second vibrating arm on the second surface, in which Wa/Aa<1 in at least one of the first and second dry etching steps, Wa is a depth of the first and second grooves formed in the first and second dry etching steps, and Aa is a depth of the contours formed in the first and second dry etching steps.

A method for manufacturing a vibration element includes: a preparing step of preparing a quartz crystal substrate having a first surface and a second surface; a protective film forming step of forming a protective film on the first surface of the quartz crystal substrate, excluding groove forming regions where grooves are formed and an inter-arm region located between a first vibrating arm forming region where a first vibrating arm is formed and a second vibrating arm forming region where a second vibrating arm is formed; and a dry etching step of dry etching the quartz crystal substrate from a first surface side via the protective film and forming the grooves and contours of the first vibrating arm and the second vibrating arm. Wa/Aa<1, wherein Wa indicates a depth of the grooves formed in the dry etching step, and Aa indicates a depth of the contours.

The disclosed technology generally relates to quartz crystal devices and more particularly to quartz crystal devices configured to vibrate in torsional mode. In one aspect, a quartz crystal device configured for temperature sensing comprises a fork-shaped quartz crystal comprising a pair of elongate tines laterally extending from a base region in a horizontal lengthwise direction of the fork-shaped quartz crystal. Each of the tines has formed on one or both of opposing sides thereof a vertically protruding line structure laterally elongated in the horizontal lengthwise direction. The quartz crystal device further comprises a first electrode and a second electrode formed on the one or both of the opposing sides of each of the tines and configured such that, when an electrical bias is applied between the first and second electrodes, the fork-shaped quartz crystal vibrates in a torsional mode in which each of the tines twists about a respective axis extending in the horizontal lengthwise direction.

The disclosed technology generally relates to quartz crystal devices and more particularly to quartz crystal devices configured to vibrate in torsional mode. In one aspect, a quartz crystal device configured for temperature sensing comprises a fork-shaped quartz crystal comprising a pair of elongate tines laterally extending from a base region in a horizontal lengthwise direction of the fork-shaped quartz crystal. Each of the tines has formed on one or both of opposing sides thereof a vertically protruding line structure laterally elongated in the horizontal lengthwise direction. The quartz crystal device further comprises a first electrode and a second electrode formed on the one or both of the opposing sides of each of the tines and configured such that, when an electrical bias is applied between the first and second electrodes, the fork-shaped quartz crystal vibrates in a torsional mode in which each of the tines twists about a respective axis extending in the horizontal lengthwise direction.

Main surface electrodes formed on main surfaces on front and back sides of vibrating arms are electrically coupled via through electrodes formed in a stem portion so as to penetrate through front and back surfaces thereof. One of the main surface electrodes of the vibrating arm is electrically coupled to side surface electrodes through a routing wiring formed by way of a crotch part between roots of the vibrating arms, and the one of the main surface electrodes is further electrically coupled to the other one of the main surface electrodes through the side surface electrodes.

Main surface electrodes formed on main surfaces on front and back sides of vibrating arms are electrically coupled via through electrodes formed in a stem portion so as to penetrate through front and back surfaces thereof. One of the main surface electrodes of the vibrating arm is electrically coupled to side surface electrodes through a routing wiring formed by way of a crotch part between roots of the vibrating arms, and the one of the main surface electrodes is further electrically coupled to the other one of the main surface electrodes through the side surface electrodes.

The disclosed technology generally relates to quartz crystal devices and more particularly to quartz crystal devices configured to vibrate in torsional mode. In one aspect, a quartz crystal device configured for temperature sensing comprises a fork-shaped quartz crystal comprising a pair of elongate tines laterally extending from a base region in a horizontal lengthwise direction of the fork-shaped quartz crystal, wherein each of the tines has formed on one or both of opposing sides thereof a pair of vertically recessed groove structures laterally elongated in the horizontal lengthwise direction, wherein the pair of groove structures are separated in a horizontal widthwise direction by a line structure. The quartz crystal device further comprises a first electrode and a second electrode formed on the one or both of the opposing sides of each of the tines and configured such that, when an electrical bias is applied between the first and second electrodes, the fork-shaped quartz crystal vibrates in a torsional mode in which each of the tines twists about a respective axis extending in the horizontal lengthwise direction.

The disclosed technology generally relates to quartz crystal devices and more particularly to quartz crystal devices configured to vibrate in torsional mode. In one aspect, a quartz crystal device configured for temperature sensing comprises a fork-shaped quartz crystal comprising a pair of elongate tines laterally extending from a base region in a horizontal lengthwise direction of the fork-shaped quartz crystal, wherein each of the tines has formed on one or both of opposing sides thereof a pair of vertically recessed groove structures laterally elongated in the horizontal lengthwise direction, wherein the pair of groove structures are separated in a horizontal widthwise direction by a line structure. The quartz crystal device further comprises a first electrode and a second electrode formed on the one or both of the opposing sides of each of the tines and configured such that, when an electrical bias is applied between the first and second electrodes, the fork-shaped quartz crystal vibrates in a torsional mode in which each of the tines twists about a respective axis extending in the horizontal lengthwise direction.