Nihon Dempa Kogyo Co., Ltd.

Shinobu Yoshida

Hirokazu Iwata

Tetsuya Watanabe

Koji Toshikawa

Takehiro Takahashi

Kenji Shimao

Kazuhiro Hirota

Hiroyuki Sasaki

Manabu Ishikawa

Yoshiharu Sato

Yoshiro Teshima

A crystal unit includes an AT-cut crystal element that has a planar shape in a rectangular shape and a part as a thick portion. The crystal element includes a first end portion, a depressed portion, the thick portion, and a second end portion in this order from a side of one short side in viewing a cross section taken along a longitudinal direction near a center of the short side. The depressed portion is a depressed portion disposed from the thick portion toward the first end portion side, depressed with a predetermined angle &#x3b8;a and subsequently bulged, and connected to the first end portion.

Crystal unit and manufacturing method thereof

A crystal unit includes an AT-cut crystal element that has a planar shape in a rectangular shape and a part as a thick portion. The crystal element includes a first end portion, a first depressed portion, the thick portion, a second depressed portion, and a second end portion in an order from a side of one short side in viewing a cross section taken along a longitudinal direction near a center of the short side. The first depressed portion is a depressed portion disposed from the thick portion toward the first end portion side, depressed with a predetermined angle &#x3b8;a and subsequently bulged, and connected to the first end portion. The second depressed portion is a depressed portion disposed from the thick portion toward the second end portion side, depressed with a predetermined angle &#x3b8;b and subsequently bulged, and connected to the second end portion.

A crystal unit includes an AT-cut crystal element that has a planar shape in a rectangular shape and a part as a thick portion. The crystal element includes a first end portion, a first depressed portion, the thick portion, a second depressed portion, and a second end portion in this order from a side of one short side, in viewing a cross section taken along a longitudinal direction near a center of the short side. The first depressed portion is a depressed portion disposed from the thick portion toward the first end portion side, depressed with a predetermined angle &#x3b8;a and subsequently bulged, and connected to the first end portion. The second depressed portion is a depressed portion disposed from the thick portion toward the second end portion side, depressed with a predetermined angle &#x3b8;b and subsequently bulged, and connected to the second end portion.

Crystal unit

Quartz-crystal devices are disclosed, of which the CI value is reduced by adjusting the shortest distance between an edge of electrically conductive adhesive and an edge of the excitation electrode. The device has a quartz-crystal plate having long-edges and short-edges. Excitation electrodes are on first and second surfaces of the plate. Conductive pads are electrically connected to respective excitation electrodes and extend to the short-edge of the quartz-crystal plate. A package having a pair of external mounting terminals and respective connecting electrodes are situated on opposing sides of the mounting terminals for making electrical connections to the mounting terminals. An electrically conductive adhesive bonds the connecting terminals and respective conductive pads together, and the quartz-crystal plate onto the package. The shortest distance between an edge of the adhesive and an edge of the excitation electrode is 10%-15% the length of the quartz-crystal plate in the long-edge direction.

Growing community of inventors

Saitama, Japan

Shinobu Yoshida