Angular velocity sensor and method of fabrication thereof

Abstract

The present invention provides an angular velocity sensor and a method of fabrication thereof that facilitates the work of affixing a tuning-fork-type crystal element and adjusting the same, preventing waste caused by scrapping defective products and also encouraging miniaturization of components. The angular velocity sensor comprises: a tuning-fork-type crystal element which is provided with a drive electrode for exciting the vibration of the tuning fork and a sensor electrode for detecting an electrical charge that is generated in response to an angular velocity that is being detected; an independent pedestal to which a main surface of a tuning-fork base portion of the tuning-fork-type crystal element is previously affixed to form an integrated unit; a main package for surface mounting, in which the tuning-fork-type crystal element is hermetically sealed and which has a cavity with an inner base surface to which the pedestal integrated with the tuning-fork-type crystal element is affixed; and an IC having an oscillation circuit for driving the tuning-fork-type crystal element and a signal processing circuit for creating a signal in correspondence to the angular velocity corresponding to the electrical charge, and which is also disposed either inside or outside the package. The pedestal has a weight and/or shape that ensures that the center of gravity of the tuning-fork-type crystal element that is integrated therewith moves towards the tuning-fork base portion side, maintaining the horizontal alignment of the tuning-fork-type crystal element.