Abstract: A mesa-shaped piezoelectric resonator element including a resonator section having a thicker thickness than a peripheral section on the board surface of a piezoelectric substrate formed in a rectangular shape, wherein, when the length of the long side of the piezoelectric substrate is x and the board thickness of the resonator section is t, etching depth y of a level-difference section is set to fulfill a relationship in the following equation, based on the board thickness t. y = - 1.

Abstract: A mesa-shaped piezoelectric resonator element including a resonator section having a thicker thickness than a peripheral section on the board surface of a piezoelectric substrate formed in a rectangular shape, wherein, when the length of the long side of the piezoelectric substrate is x and the board thickness of the resonator section is t, etching depth y of a level-difference section is set to fulfill a relationship in the following equation, based on the board thickness t. y = - 1.

Abstract: A mesa-shaped piezoelectric resonator element including a resonator section having a thicker thickness than a peripheral section on the board surface of a piezoelectric substrate formed in a rectangular shape, wherein, when the length of the long side of the piezoelectric substrate is x and the board thickness of the resonator section is t, etching depth y of a level-difference section is set to fulfill a relationship in the following equation, based on the board thickness t. y = - 1.

Abstract: An AT cut quartz crystal resonator element includes a quartz crystal element piece having an exciting part formed from an AT cut quartz crystal plate in a rectangular shape having an X-axis direction of a quartz crystal set to a long side, and an exciting electrode formed on each of front and back main surfaces of the exciting part, in which each side surface in the longitudinal direction of the exciting part is composed of two faces, an m-face of a quartz crystal and a crystal face other than the m-face.

Abstract: An AT cut quartz crystal resonator element includes a quartz crystal element piece having an exciting part formed from an AT cut quartz crystal plate in a rectangular shape having an X-axis direction of a quartz crystal set to a long side, and an exciting electrode formed on each of front and back main surfaces of the exciting part, in which each side surface in the longitudinal direction of the exciting part is composed of two faces, an m-face of a quartz crystal and a crystal face other than the m-face.

Abstract: An AT cut quartz crystal resonator element includes a quartz crystal element piece having an exciting part formed from an AT cut quartz crystal plate in a rectangular shape having an X-axis direction of a quartz crystal set to a long side, and an exciting electrode formed on each of front and back main surfaces of the exciting part, in which each side surface in the longitudinal direction of the exciting part is composed of two faces, an m-face of a quartz crystal and a crystal face other than the m-face.

Abstract: An AT cut quartz crystal resonator element includes a quartz crystal element piece having an exciting part formed from an AT cut quartz crystal plate in a rectangular shape having an X-axis direction of a quartz crystal set to a long side, and an exciting electrode formed on each of front and back main surfaces of the exciting part, in which each side surface in the longitudinal direction of the exciting part is composed of two faces, an m-face of a quartz crystal and a crystal face other than the m-face.

Abstract: An AT cut quartz crystal resonator element includes a quartz crystal element piece having an exciting part formed from an AT cut quartz crystal plate in a rectangular shape having an X-axis direction of a quartz crystal set to a long side, and an exciting electrode formed on each of front and back main surfaces of the exciting part, in which each side surface in the longitudinal direction of the exciting part is composed of two faces, an m-face of a quartz crystal and a crystal face other than the m-face.

Abstract: An AT cut quartz crystal resonator element includes a quartz crystal element piece having an exciting part formed from an AT cut quartz crystal plate in a rectangular shape having an X-axis direction of a quartz crystal set to a long side, and an exciting electrode formed on each of front and back main surfaces of the exciting part, in which each side surface in the longitudinal direction of the exciting part is composed of two faces, an m-face of a quartz crystal and a crystal face other than the m-face.

Abstract: A mesa-shaped piezoelectric resonator element including a resonator section having a thicker thickness than a peripheral section on the board surface of a piezoelectric substrate formed in a rectangular shape, wherein, when the length of the long side of the piezoelectric substrate is x and the board thickness of the resonator section is t, etching depth y of a level-difference section is set to fulfill a relationship in the following equation, based on the board thickness t. y = - 1.

Abstract: A two-layered metal oxide film resistor having a ceramic substrate which has on its surface a first thin (0.1-5 .mu.m) metal oxide film that is based on tin oxide and which has a minor proportion of at least one auxiliary component selected from iron, indium, nickel, phosphorus, zinc, cadmium and antimony, and a second thin (0.003-1 .mu.m) metal oxide film superposed on the first film that is also based on tin oxide but which contains a minor proportion of at least one auxiliary component selected from antimony, nickel, chromium, fluorine, phosphorus, arsenic, iron, manganese, barium, bismuth, cobalt, zinc, copper, boron, cadmium and vanadium.