JPS6465912A - Longitudinal crystal resonator - Google Patents

Abstract

PURPOSE:To obtain a longitudinal crystal resonator with a less vibration leakage and a cut angle to give zero temperature coefficient by enclosing the resonator by a curved part, and connecting the curved part to the frame opposite to a mount side, and besides, rotating a Z plate by a specified angle around the axis of rotation of X axis, and further, installing an exciting electrode on a surface perpendicular to the X axis. CONSTITUTION:In order to excite freely the vibration in a longitudinal direction of a vibrating part 2, it is important to make the vibration in the direction of a bridge part 4 sufficiently free. For this purpose, the suppression of the vibration in the longitudinal direction is prevented by the ratio of the length L and the width W of the curved part 5 of a supporting part 3, i.e., in case of the frequency of 1 MHz, by making W/L be less than 0.16. Next, as for the vibration leakage, the vibrating part 2 and the curved part 5 are formed into one body through the bridge part 4 by an etching method, and its end part is connected to the frame 6. Accordingly, since energy can be confined in the tip of the supporting part 3, a longitudinal crystal resonator entirely free of the vibration leakage is obtained. Besides, the peak temperature Tp can be freely changed according to the cut angle theta. Then, frequency change is made small especially in the range of -10 deg.C-+60 deg.C by choosing the cut angle in the range of -2 degrees-+4 degrees.