Tdk Corporation

Eiju Komuro

Roger William Whatmore

Masaaki Imura

Hisatoshi Saitou

Paul B Kirby

Qingxin Su

Katsuhiko Gunji

Takao Noguchi

Taku Takeishi

Tohru Kineri

Kenji Inoue

Tsutomu Yasui

Yasunobu Oikawa

Osamu Shinoura

Hidenori Abe

Yoshinari Yamashita

Akira Shibue

Kouji Tanabe

Toshiyuki Nagatsuka

Yumiko Ozaki

Joseph Edward Albert Southin

A thin film capacitor and a method of manufacturing the same are provided. The thin film capacitor includes a metal foil, dielectric layers and internal electrode layers alternately disposed on the metal foil, and a top electrode layer on the topmost layer among the two or more dielectric layers. These layers have peripheries that define an outer profile flaring toward the metal foil as viewed from the stacking direction of the thin film capacitor, and at least one dielectric layer of two or more dielectric layers satisfies a relationship B&#x3e;A&#x3e;0 wherein A is a gap of the periphery of the internal electrode layer directly below the dielectric layer protruding from the periphery of the dielectric layer, and B is a gap of the periphery of the dielectric layer protruding from the periphery of the internal electrode layer or the top electrode layer directly above the dielectric layer. The thin film capacitor has a structure free from short-circuiting and reducing debris of broken dielectric material.

Method of manufacturing a thin film capacitor having separated dielectric films

A method of manufacturing a thin-film electronic device comprising providing a dielectric layer on a base, providing a first electrically conductive layer having a first opening and covering at least part of the dielectric layer; and forming a first through-hole extending through the base and communicating with the first opening. A second electrically conductive layer may be provided on the base, and a dielectric layer may be provided so as to cover at least part of this second conductive layer.

Method of manufacturing thin-film electronic device having a through-hole extending through the base and in communicative connection with an opening in the electrically conductive layer

A method of manufacturing a piezoelectric thin film resonator forms, after forming a piezoelectric film on a substrate so as to cover a lower electrode formed on the substrate, an electrode material layer for forming an upper electrode above the piezoelectric film, forms a mask of a predetermined form on the electrode material layer, and then etches the electrode material layer to form the upper electrode. Before a step of forming the electrode material layer, a protective layer for protecting the piezoelectric film during etching of the electrode material layer is formed so as to cover at least a part of the piezoelectric film where the upper electrode is not formed, and the electrode material layer is then formed so as to cover the protective layer.

Method of manufacturing a piezoelectric thin film resonator, manufacturing apparatus for a piezoelectric thin film resonator, piezoelectric thin film resonator, and electronic component

A ladder-type film bulk acoustic resonator (FBAR) filter comprises two series FBARs and two parallel FBARs. Each FBAR has a top electrode, a bottom electrode, and a piezoelectric layer sandwiched between the top and bottom electrodes. The top electrodes of the two series FBARs form part of a signal line of a coplanar waveguide transmission line. The top electrodes of the two series FBARs are connected to associated circuitry. The two series FBARs have a common bottom electrode.

Film bulk acoustic resonator filter

Multiple thin film bulk acoustic resonators () configured in series () and parallel () within a coplanar waveguide line structure provides a compact ladder filter. The resonators () are formed over an opening () in a substrate () and connected to associated circuitry by one or more transmission lines formed on the substrate (). The arrangement of the resonators () between the ground and signal lines of a coplanar line structure provides a means of minimising the area of the filter. Embedding a ladder filter within the coplanar transmission line structure eliminates the need for wire bonds, thus simplifying fabrication. Embodiments for 2&#xd7;2, and hither order filters are described.

Film bulk acoustic resonator filters with a coplanar waveguide

An electric filter according to an embodiment of the present invention is an electric filter having a piezoelectric resonatorto obtain a signal of a predetermined resonance frequency from a bulk wave propagating inside a piezoelectric filmThis electric filter is configured to satisfy k&#x3e;(BP/0.6f), where kis the square of an effective electromechanical coupling coefficient of the piezoelectric resonatorBP a pass bandwidth of the electric filter, and f a center frequency of a target pass band of the electric filter.

Electric filter, and duplexer using the same

A method of manufacturing a piezoelectric thin film resonator forms, after forming a piezoelectric film on a substrate so as to cover a lower electrode formed on the substrate, a resist layer so as to cover the piezoelectric film, forms a mask composed of the resist layer on the piezoelectric film by forming, in the resist layer, an exposure hole for exposing a formation part of an upper electrode on the piezoelectric film, forms an electrode material layer for forming the upper electrode on the piezoelectric film exposed via the exposure hole and on the mask, and then forms the upper electrode by removing the electrode material layer on the mask by removing the mask.

Method of manufacturing a piezoelectric thin film resonator

A thin-film bulk acoustic oscillator comprises: a base; a barrier layer disposed on the base; a lower electrode disposed on the barrier layer; a piezoelectric thin film disposed on the lower electrode; and an upper electrode disposed on the piezoelectric thin film. The piezoelectric thin film includes a columnar crystal that extends in the direction intersecting the film surface. The top surface of the piezoelectric thin film is flattened by polishing so as to have a root mean square roughness of 2 nm or smaller.

Thin-film bulk acoustic oscillator and method of manufacturing same

A duplexer () comprises a chip () including a transmission filter () for passing a transmission signal therethrough and interrupting a reception signal and a reception filter () for passing a reception signal therethrough and interrupting a transmission signal. Each of the transmission filter () and the reception filter () includes thin-film piezoelectric resonators (and) each of which has a piezoelectric thin film that exhibits a piezoelectric property and two excitation electrodes that are disposed on both surfaces of the piezoelectric thin film and apply an excitation voltage to the piezoelectric thin film. All of the thin-film piezoelectric resonators (and) that the transmission filter () and the reception filter () include are disposed on a single base.

Duplexer and method of manufacturing same

An electric filter comprises a plurality of thin film bulk acoustic resonants () arranged in series and in parallel which have electrodes () of different working area (L) and optionally a piezoelectric layer () of different thickness (T).

Electric filter comprising a plurality of thin film bulk acoustic resonators

A method for manufacturing a piezo-resonator including: a first step of forming an upper electrode layeron the piezoelectric film, a second step of coating the upper electrode layerwith a resistand of performing patterning on the resist so as to have a shape of the upper electrode, a third step of masking the patterned resistand removing the upper electrode layerother than masked portions and forming two or more first upper electrodes, a fourth step of removing the resist, a fifth step of coating the first upper electrodeswith a resist and performing patterning on the resist so that the first upper electrodesare partially exposed, a sixth step of etching each of the exposed first upper electrodesby a specified thickness to form a second upper electrode, and a seventh step of removing the resist

Method for manufacturing piezo-resonator

A piezoelectric resonant filter includes a group of series resonators and a group of parallel resonators for forming a ladder-type filter circuit. Each of the resonators has a piezoelectric thin film having piezoelectric characteristic, and lower and upper electrodes disposed on opposite surfaces of the piezoelectric thin film for applying an excitation voltage to the piezoelectric thin film. The group of the parallel resonators exhibits a low frequency side attenuation extremum in the filter whereas the group of the series resonators exhibits a high frequency side attenuation extremum in the filter. At least one of the group of the series resonators and the group of the parallel resonators has a temperature compensating layer for bringing the temperature coefficient of the resonant frequency close to zero.

Piezoelectric resonant filter and duplexer

A thin-film piezoelectric resonator including a piezoelectric thin film having piezoelectric characteristic, and an upper electrode and a lower electrode arranged on opposite surfaces of the piezoelectric thin film for applying an excitation voltage to the piezoelectric thin film, wherein: each of the upper electrode and the lower electrode includes a resonant portion, and a lead-out portion; and the electrode thickness of at least one part of the lead-out portion in at least one of the upper electrode and the lower electrode is larger than the electrode thickness of the resonant portion formed to be continued from the lead-out portion.

Thin-film piezoelectric resonator and method for fabricating the same

In an electronic component having a piezo-electric resonatorformed on an element substrateand obtaining a signal having a predetermined resonant frequency by a bulk wave propagating within a piezo-electric film, a mounting substrateon which the piezo-electric resonatoris mounted by face-down bonding through N bumps, when a maximum diameter of said N bumpsis defined as D &#x3bc;m, die shear strength of said N bumpsis not smaller than ND/6 (g), preferably, not smaller than ND/3.6 (g).

Electronic component including piezo-electric resonator mounted by face-down bonding with a required die shear strength

A piezoelectric resonant filter comprises a chip having a plurality of thin-film piezoelectric resonators, and a mounting substrate on which the chip is mounted. The chip is mounted on the mounting substrate by flip chip bonding. A plurality of bumps provided on the chip are bonded to a plurality of conductors on the mounting substrate by interdiffusion between atoms, in a solid phase, of the respective metals of which the bumps and the conductors are made, without involving melting of the respective metals of which the bumps and the conductors are made. The chip has a series resonator and a parallel resonator each formed of a thin-film piezoelectric resonator. These resonators constitute a ladder filter circuit.

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Tokyo, Japan

Eiju Komuro