Patent ID: 7716807

Claim:
A manufacturing method of a tuning fork type crystal component for an angular velocity sensor comprising: a tuning fork shaped crystal element having a pair of tuning fork arms extending from a tuning fork base portion where an X axis of a crystal axis (XYZ) is a widthwise direction, a Y axis is a lengthwise direction and a Z axis is a depthwise direction; and mutually electrically separated first and second sensor electrodes for angular velocity detection formed on at least one face among side faces of said tuning fork arms; wherein said manufacturing method comprises the steps of: an outline processing for forming on a single crystal wafer by a photo-etching technique, a number of said tuning fork shaped crystal elements having protrusion ridge line sections that have remained in the lengthwise direction of +X faces of the crystal, caused by etching anisotropy; an electrode material formation for forming a metallic film on each side face including both principal planes and said +X face of said tuning fork shaped crystal element of said single crystal wafer; and an electrode dividing for dividing the metallic film of said +X face along said protrusion ridge line section, and forming said first and second sensor electrodes, wherein said electrode dividing step is performed with a photoetching technique, and comprises: forming a positive or negative type photo-resist film on the metallic film of said +X face; removing the photo-resist film on said protrusion ridge line section by selective exposure and development appropriate to the positive type or negative type resist, thereby exposing said metallic film portion; and wet etching said metallic film portion to divide said metallic film and form said first and second sensor electrodes.