Nihon Dempa Kogyo Co., Ltd.

Genwa Koki

Shigeru Obara

Masaaki Nakahara

Kouichi Hara

Takahiko Iwasaki

Mikio Saito

Mituaki Koyama

The present invention relates to a crystal oscillator that is provided with a crystal element; a main surface electrode configured of a first underlayer formed on each of two main surfaces of the crystal element and a first surface layer of Au superimposed over the first underlayer; an end surface electrode having a second underlayer formed on the crystal element to extend over the main surface electrode and a second surface layer of Au superimposed to cover the second underlayer; a supporter for holding the crystal element in the horizontal direction, bonded to the end surface electrode by a eutectic alloy comprising at least Au; and a base on which the supporter stands. An intermediate layer is provided between the second underlayer and the second surface layer of the end surface electrode; the intermediate layer protrudes further towards the center over the main surface electrode than the second surface layer; and also the intermediate layer is formed of a metal having the characteristic of increasing the adhesive strength between the underlayer and the second surface layer as well as that of the eutectic alloy. The present invention provides a crystal oscillator in which bonding is done with a eutectic alloy that has a higher bond strength, thus preventing peeling of the electrodes.

Crystal oscillator

An IT-cut quartz crystal unit has a discoidal or a rectangular quartz crystal blank which is cut from a crystal of quartz along a plane perpendicular to the Y-axis of the crystal of the quartz which is rotated over approximately 34&#xb0; about the X-axis, and further rotated from this rotated position over approximately 19&#xb0; about the Z-axis. Excitation electrodes are formed on both main surface of the crystal blank, respectively. The crystal blank is held at positions in at least one set of opposing peripheral regions selected from an angular range of 18&#xb0;&#xb1;18&#xb0; from the Z'-axis on the surface of the crystal blank, viewed from the center on the surface of the crystal blank; an angular range of 198&#xb0;&#xb1;18&#xb0; from the Z&#x2032;-axis; an angular range of 108&#xb0;&#xb1;18&#xb0; from the Z&#x2032;-axis; and an angular range of 288&#xb0;&#xb1;18&#xb0; from the Z&#x2032;-axis.

IT-cut quartz crystal unit

In a crystal unit suitable for use in a thermostat oven, a first and a second excitation electrode are disposed on a first and a second surface of a crystal blank. A first and a second connection are disposed on the second surface as connections formed by applying a fillet of a mixture of a low-melting glass and a metal filler, and melting the fillet by heating. A third connection is disposed on a peripheral edge of the crystal blank to extend over both surfaces. A lead of the first excitation electrode is directly connected to the third connection, while a lead of the second excitation electrode is connected to the first connection through a vapor-deposited metal thin film. The second and third connections are connected to each other through a vapor-deposited metal thin film. The first and second connections are secured to a pair of holding members by brazing.

Growing community of inventors

Saitama, Japan

Genwa Koki