Nihon Dempa Kogyo Co., Ltd.

Masahiro Yoshimatsu

Kozo Ono

Takehiro Takahashi

Hiroki Iwai

Shingo Kawanishi

Motoo Takada

Takahiro Inoue

Hideryo Matsudo

Kenichi Kikuchi

Tamotsu Kurosawa

Nobuo Hiruma

Takuji Yamamoto

An optical filter is provided having an optical plate which has a chamfered section formed on an outer peripheral edge section of one principle surface of the optical plate and has isotropy with respect to wet-etching. The chamfered section is of an arc shape which is cross-sectionally concave in an inward direction of the optical plate.

Optical filter

Methods are provided for manufacturing piezoelectric devices. In an exemplary method, a base wafer is prepared that defines an array of multiple bases. Between each base on the wafer is a through-hole defined in respective parts by the respective edge surfaces of adjacent bases. A piezoelectric wafer is prepared that defines an array of multiple piezoelectric frames each having a piezoelectric vibrating piece and a surrounding frame portion. The vibrating piece includes an excitation electrode and extraction electrode. The extraction electrode extends to the through-hole. An adhesive is applied to a surface of the frame portion including a surface of the extraction electrode. The adhesive bonds the piezoelectric wafer to the base wafer. Excess adhesive is removed from the through-hole to expose a portion of the extraction electrode in the through-hole. An external electrode is formed on the outer surface of the base and extends to the through-hole in which the external electrode covers the edge surface of the through-hole, an edge surface of the adhesive, and the exposed portion of the extraction electrode.

Methods for manufacturing piezoelectric devices

Piezoelectric vibrating pieces are disclosed made of a piezoelectric material to be mounted in a package. A representative piece includes a base formed of a piezoelectric material, having first and second ends, extending between the ends in a length direction, and having a designated width. The piece includes at least a pair of vibrating arms extending in the length direction from one end of the base, and a pair of supporting arms extending partially in a width direction from between the first and second ends of the base. The supporting arms further extend in the length direction outboard of the base and vibrating arms, and include an adhesive region at the tips of the supporting arms. The adhesive regions are used for mounting the piece to a package. Whereas the tips of the supporting arms do not extend beyond the tips of the vibrating arms, the axial length of supporting arms is greater than the length of the vibrating arms.

Piezoelectric vibrating piece with extended supporting arms

Piezoelectric vibrating pieces are disclosed that have a base and a pair of vibrating arms extending from one end of the base in a designated direction. A respective groove is defined in each of the upper and lower surfaces of each vibrating arm. The grooves extend in the designated direction and have a first width. Each groove includes a respective rib feature having a second width that is narrower than the first width. A piezoelectric frame includes the piezoelectric device and an outer frame surrounding the device. A piezoelectric device includes the piezoelectric vibrating piece or piezoelectric frame, a lid, and a base.

Piezoelectric vibrating pieces, frames, and devices

A stacked crystal unit includes: a first crystal plate in which a vibration member links to an outer circumferential frame portion, and a pair of extending electrode extends to the frame portion from excitation electrodes; and a second and third crystal plates which have a concave portion in an area opposite to the vibration member and whose open end surfaces are joined by direct bonding to both principal surfaces of the frame portion in the first crystal plate. The extending electrodes are electrically extended to an outer surface of at least one of the second and third crystal plates via electrode through-holes provided in the frame portion. The electrode through-hole includes: a first electrode through-hole penetrating through the frame portion from the principal surface of the frame portion where the extending electrode extends; and a second electrode through-hole provided in the second or third crystal plate.

Crystal unit having stacked structure

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.

Growing community of inventors

Saitama, Japan

Masahiro Yoshimatsu