Nihon Dempa Kogyo Co., Ltd.

Kenichi Kikuchi

Mitoshi Umeki

Hiroyuki Sasaki

Ryoichi Ichikawa

Toshimasa Tsuda

Kenji Shimao

Yoshiaki Amano

Manabu Ishikawa

Tomotaka Kuroda

Masahiro Yoshimatsu

Makoto Hatano

Takahiro Inoue

Hideryo Matsudo

Daisuke Nishiyama

Keisuke Hirano

Kenji Kamezawa

Hiroya Ishikawa

Noritsugu Matsukura

A solder material includes an alloy of at least five elements including Sn, Cu, Sb, and In, and 20 mass % or less of Ag. The solidus temperature of the solder material is higher than 290&#xb0; C., the liquidus temperature of the solder material is 379&#xb0; C. or less and is higher than the solidus temperature, and the temperature difference between the liquidus temperature and the solidus temperature is 70&#xb0; C. or less.

Solder material and electronic component

An exemplary piezoelectric vibrating device includes a piezoelectric vibrating piece that vibrates when electrically energized. A first package plate has a main recess in which the piezoelectric vibrating piece is placed, and a peripheral surface surrounding the recess. A second package plate is bonded to the peripheral surface of the first package plate in airtight manner. A band of adhesive bonds the first package plate to the second package plate. The adhesive band surrounds the peripheral surface. Between the adhesive and the main recess is a band of metal film. The band of metal film prevents gas, generated from the adhesive, from flowing into the recess. The band of metal film surrounds the peripheral surface and is disposed inboard of the band of adhesive.

Piezoelectric vibrating devices and methods for manufacturing same

Piezoelectric vibrating pieces are disclosed having selectively roughened surfaces. An exemplary piece is made of a piezoelectric material configured as a piezoelectric substrate. The piece also includes at least one excitation electrode and at least one extraction electrode. The substrate has opposing main surfaces initially having low surface roughness. At least one main surface is formed in a mesa or reverse mesa manner, wherein the central region has a different thickness than the peripheral region. The central region has relatively low surface roughness (irregular unevenness), while the peripheral region has relatively high surface roughness. The excitation electrode is formed on the central region (mesa or reverse mesa) while the extraction electrode (connected to the excitation electrode) is formed on the peripheral region.

Piezoelectric vibrating pieces and devices, and methods for manufacturing same

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.

Angular velocity sensor and method of fabrication thereof

A crystal unit comprises an AT-cut crystal blank, and an excitation electrode formed on each of opposing main surfaces of the crystal blank in an oscillation region of the crystal blank. The ratio b/a is 0.014 or less, and preferably 0.012 or less where a represents the thickness of the crystal blank in the oscillation region and b represents the thickness of the excitation electrode. The thickness a is typically 5 &#x3bc;m or less.

Crystal unit

Growing community of inventors

Saitama, Japan

Kenichi Kikuchi