Nihon Dempa Kogyo Co., Ltd.

Jeol Ltd.

Ryoichi Ichikawa

Mitoshi Umeki

Yoshiaki Amano

Hiroki Iwai

Mitsuaki Koyama

Takeru Mutoh

Takefumi Saito

Kenji Kamezawa

Hiroshi Kawahara

Shuichi Mizusawa

Yuji Hasegawa

Shingo Kawanishi

Takahiro Inoue

Kenichi Kikuchi

Yu Iwai

Naohito Inoue

Kazutomo Shimizu

Noritsugu Matsukura

Akihiko Haraguchi

A device is provided for a detecting external force applied to piezoelectric piece. A crystal piece is cantilever-supported in a container. Excitation electrodes are formed on an upper face and lower face, respectively. A movable electrode, connected via a lead-out electrode to the excitation electrode, is formed on the lower face side at a front end of the crystal piece. A fixed electrode is provided on a bottom portion of the container to face this movable electrode. The excitation electrode on the upper face side and the fixed electrode are connected to an oscillation circuit. When the crystal piece bends in response to an applied external force, capacitance between the movable electrode and fixed electrode, changes. This capacitance change results in a corresponding change in oscillation frequency of the crystal piece.

External force detecting device and external force detecting sensor

An acceleration measuring apparatus that can easily detect acceleration with high accuracy is provided. In the apparatus, positional displacement of a swingable pendulum member is detected, feedback control is performed to maintain the pendulum member in a stationary state using an actuator, and acceleration is measured by measuring the output of the actuator at this time. A movable electrode is provided to the pendulum member, and a loop is formed in which a fixed electrode provided to oppose the movable electrode, and an oscillating circuit, a crystal unit, and the movable electrode are electrically connected in series. By measuring an oscillating frequency of the oscillating circuit at this time, a change in the size of a variable capacitance formed between the movable electrode and the fixed electrode is detected, and thereby the positional displacement of the pendulum member is detected.

Acceleration measuring apparatus

In an external force detection apparatus, a crystal plate is cantilevered within a container. Excitation electrodes are formed on the top surface and the bottom surface of the crystal plate. A movable electrode is formed on a distal end on the bottom surface of the crystal plate and is connected to the excitation electrode on the bottom surface via an extraction electrode. A fixed electrode is provided on the bottom of the container to oppose the movable electrode. The excitation electrode on the top surface and the fixed electrode are connected to an oscillating circuit. When an external force acts on the crystal plate to bend it, the capacitance between the movable electrode and the fixed electrode changes, and this capacitance change is captured as a change in the oscillating frequency of the crystal plate.

External force detection apparatus and external force detection sensor

Piezoelectric vibrating devices are disclosed that lack base through-holes and that can be manufactured on a wafer scale. Also disclosed are methods for making same. An exemplary piezoelectric device has a package base having first and second opposing main surfaces. On the second (outer) first main surface is formed a pair of external electrodes. The first (inner) main surface defines a first recess and a peripheral first bonding surface. A pair of connecting electrodes are provided for connecting to the respective external electrodes via respective edge surfaces of the package base that extend between the first and second main surfaces. A piezoelectric vibrating piece is mounted in and contained within the package base. The vibrating piece includes a pair of excitation electrodes electrically connected to respective connecting electrodes. A package lid comprises first and second main surfaces, of which the second (inner) main surface defines a second recess that is larger than the first recess. The second main surface also defines a second bonding surface that peripherally surrounds the second recess. A sealing material is applied, over the width of the second bonding surface, circumferentially between the first bonding surface and the second bonding surface.

Piezoelectric vibrating devices including respective packages in which castellations include respective connecting electrodes

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

To provide a piezoelectric device prevented from overflowing of sealing materials. The piezoelectric device () stores a piezoelectric vibrating piece () having a pair of excitation electrodes. The piezoelectric device comprises: a package lid (), including a first bonding surface (M) formed in periphery of the package lid in a circumferential pattern and a lid recess (); a package base (), including a second bonding surface (M), a base recess surrounded by a second bonding surface that is higher than the second bonding surface, and a pair of seats that is protruding from the base recess, situated for mounting the piezoelectric piece; a piezoelectric piece mounted onto the pair of seats; and a non electric conductive sealing material () disposed peripherally in relative to the first bonding surface and the second bonding surface in a circumferential pattern, thus the adhesive bonding the first bonding surface and the second bonding surface. Furthermore, height of the second bonding surface and the pair of seats are same height.

Method of manufacturing the piezoelectric device and the same

A tuning-fork type piezoelectric vibrating piece () is comprised of a base portion () comprising a piezoelectric material, a pair of vibrating arms () extends parallel from the base portion with a first thickness, a excitation electrode film () formed on the vibrating arms, a pair of tuning portions () formed at the distal ends of the vibrating arms () with a second thickness which is less than the first thickness; and a metal film () formed on at least one surface of the tuning portion.

Tuning-fork type piezoelectric vibrating piece with enhanced frequency adjustment and piezoelectric device incorporating same

Methods are provided for manufacturing piezoelectric vibrating devices that do not contain any unwanted gas or water vapor inside the devices. In an exemplary method, a base wafer is prepared including multiple package bases each having a first main surface and a second main surface. The base wafer also includes a pair of through-holes disposed between adjacent package bases of the base wafer. A piezoelectric vibrating piece is placed on each package base. A lid wafer is prepared that includes multiple package lids. A sealing material is applied to the base wafer or lid wafer in peripheral bands used for bonding the bases and lids together and defines respective interior cavities. The band of sealing material includes a communicating groove that communicates from the inner cavity to the first through-hole. The base wafer and lid wafer are subject to heat and compression to effect bonding. Meanwhile, the cavities are allowed to ventilate through the communicating grooves and through-holes to ensure that the cavities have a desired vacuum level or inert gas contents before completion of sealing.

Methods for manufacturing piezoelectric devices

Piezoelectric devices are disclosed that are mountable on the surface of a printed circuit board or the like. An exemplary device comprises a piezoelectric vibrating piece enclosed and sealed within a package including at least a cover and a base-substrate formed of glass or piezoelectric material. The package includes frame-shaped metallic films formed in peripheral regions of inner main surfaces of the cover and/or the base substrate. The frame-shaped metallic films are used for sealing the package using a eutectic material (e.g., solder). At least one mounting terminal is provided on the outer (bottom) main surface of the base-substrate. At least one of the frame-shaped metallic films and mounting terminals includes a chromium foundation layer formed on the surface of the glass or piezoelectric material, a middle layer of NiW alloy formed on the surface of the chromium layer, and a gold layer formed on the surface of the middle layer.

Surface-mountable piezoelectric devices including eutectic-bonded packages

In an exemplary method a piezoelectric wafer is prepared on which multiple piezoelectric frames are formed. Each frame has a piezoelectric vibrating piece including excitation electrodes, and a frame portion surrounds the vibrating piece. A lid wafer is prepared on which multiple respective lids are formed, each sized substantially similarly to the respective frames. A base wafer is prepared on which multiple of bases are formed, each sized substantially similarly to the respective frames. Each base has through-holes. Stripes of a first bonding film are formed on both major surfaces of the piezoelectric wafer around the periphery of each frame. Stripes of a second bonding film are formed on the inner major surface of the lid wafer, corresponding to respective stripes of the first bonding film. Stripes of a third bonding film are formed on the inner major surface of the base wafer, corresponding to respective stripes of the first bonding film. A bonding material is placed between the stripes of first bonding film and respective stripes of second bonding film, and between stripes of first bonding film and respective stripes of third bonding film, by which the three wafers are bonded together after being aligned with each other in a sandwich manner.

Methods for manufacturing piezoelectric vibrating pieces

Piezoelectric devices are disclosed that include a chip plate sandwiched between a lid plate and a base plate. The chip plate includes a tuning-fork type piezoelectric vibrating piece surrounded by an outer frame. The lid plate includes a concavity on its inner major surface, and the base plate includes a concavity on its inner major surface. The lid plate, chip plate, and base plate are bonded together to form a package containing the piezoelectric vibrating piece. The tuning-fork type piezoelectric vibrating piece includes a base having an X-direction width and at least pair of vibrating arms extending from the base in a Y-direction. The tuning-fork type piezoelectric vibrating piece is coupled to the outer frame by supporting arms extending in the Y-direction outboard of the vibrating arms. The concavity of the lid plate includes at least one base-movement 'buffer' extending in the X-direction at a location corresponding to the base of the vibrating piece. The concavity of the base plate includes at least one base-movement buffer extending in the X-direction at a location corresponding to the base.

Impact-resistant piezoelectric devices

Methods are disclosed for manufacturing piezoelectric devices. In an exemplary method a base substrate is prepared that defines multiple device bases. Multiple cutting grooves are defined on a surface of the base substrate in a grid pattern to define therebetween the size of the devices. A frame substrate is also prepared from a piezoelectric material. The frame substrate defines multiple frames surrounding respective vibrating pieces and being alignable with respective bases in the base substrate. Also prepared is a lid substrate defining multiple lids being alignable with respective frames and bases. The three substrates are aligned and bonded together such that the frame substrate is between the lid and base substrates and the surface defining the cutting grooves faces outward. The base substrate is mounted on a dicing sheet such that cutting grooves face the dicing sheet. Cutting is performed, using a dicing blade, through the sandwich from the lid substrate to the cutting grooves.

Piezoelectric devices and methods for manufacturing same

A piezoelectric frame () is comprised of a tuning-fork type piezoelectric vibrating piece () having a pair of vibrating arms () extending from a base portion () wherein excitation electrodes are formed on the vibrating arms, an outer frame () surrounding the tuning-fork type piezoelectric vibrating piece, a pair of supporting arms () extending from the base portion to the outer frame portion and supporting the tuning-fork type piezoelectric vibrating piece; and an acute angle portion () formed on a side surface between the outer frame and the tuning-fork type piezoelectric vibrating piece and having an acute angle seen from Z-direction.

Piezoelectric frame and piezoelectric device incorporating same

Methods are disclosed for manufacturing piezoelectric devices. An exemplary method comprises the step of bonding a lid wafer, a piezoelectric frame wafer (having a vibrating piece and a outer frame surrounding the vibrating piece), and a base wafer (having at least one wiring through-hole) together. A surface of a unit (typically ball-shaped) of eutectic metal is cleaned and then arranged on the through-hole. The unit of eutectic metal is then melted in a vacuum or inert gas environment to allow the eutectic metal to enter the through-hole.

Manufacturing methods of piezoelectric devices

An object is to provide a crystal device that uses a mesa-structure crystal piece in which frequency adjustment is possible. A configuration is such that in a crystal device having: a crystal piece having a thick portion and a thin portion, with an excitation electrode formed on both main faces of the thick portion, and a lead out electrode electrically connected to the excitation electrode, formed on an end portion; a container main body having a concavity for accommodating the crystal piece; and a cover that is connected to an open end face of the container main body and hermetically seals the crystal piece, a frequency adjustment metal film which is electrically isolated from the excitation electrode and made independent, is formed on the thin portion of the crystal piece.

Growing community of inventors

Saitama, Japan

Ryoichi Ichikawa