Fujitsu Corporation

Fujitsu Media Devices Limited

Masahiko Imai

Takeaki Shimanouchi

Satoshi Ueda

Tadashi Nakatani

Xiaoyu Mi

Anh Tuan Nguyen

Takashi Matsuda

Takashi Katsuki

Masanori Ueda

Michio Miura

Osamu Ikata

Osamu Toyoda

Yu Yonezawa

Jun Tsutsumi

Shogo Inoue

Tsutomu Miyashita

Naoyuki Mishima

Yoshio Sato

There is provided a method for fabricating a device, preferably for a micro electro electro mechanical system. The method includes forming a first electrode on a substrate, where the first electrode has a first sloped end at least at one end thereof; forming a sacrificial layer on the first electrode, where the sacrificial layer has a first sloped edge, the first sloped edge and the first sloped end are overlapped each other so that a thickness of the first sloped edge decreases as a thickness of the first sloped end increases; forming a first spacer on the first electrode, where the first spacer has contact with the first sloped edge; forming a beam electrode on the sacrificial layer and the first spacer; and removing the sacrificial layer after the forming the beam electrode.

Method for fabricating MEMS device and MEMS device

There is proved a variable capacitor that includes a substrate, a signal line disposed on a surface of the substrate for feeding a signal, a ground electrode disposed on the surface, and a movable electrode opposed the signal line and the ground electrode, the movable electrode operable to move toward and away from the signal line and the ground electrode. The movable electrode can be displaced by an electrostatic attraction between the movable electrode and the signal line and between the movable electrode and the signal line. An amount of displacement of the movable electrode varies according to an amount of the voltage which generates the electrostatic attraction.

Variable capacitor, matching circuit element, and mobile terminal apparatus

A driving method for driving an electrostatic actuator including a fixed electrode and a movable electrode opposing each other with a dielectric layer interposed therebetween, includes applying a first voltage, between the fixed electrode and the movable electrode, to bring the movable electrode into contact with the dielectric layer, and applying a second voltage, between the fixed electrode and the movable electrode, after application of the first voltage is stopped and before the movable electrode moves away from the dielectric layer. Here, the second voltage has a polarity opposite to a polarity of the first voltage and an absolute value smaller than an absolute value of the first voltage.

Electrostatic actuator and driving method thereof

A variable capacitive element includes a first fixed electrode and a second fixed electrode that are insulated from each other, a movable electrode arranged to face the first fixed electrode and the second fixed electrode, a dielectric layer provided between the movable electrode and the first fixed electrode as well as the second fixed electrode, a first wiring part for applying a first driving voltage to the first fixed electrode with reference to a potential of the movable electrode, and a second wiring part for applying a second driving voltage to the second fixed electrode with reference to the potential of the movable electrode, the second driving voltage having a polarity different from a polarity of the first driving voltage.

Variable capacitive element, variable capacitive device, and method for driving the variable capacitive element

A variable capacitance element provided with a substrate, a signal line provided on the substrate, a fixed electrode provided on the substrate, and a movable electrode. The movable electrode includes a movable portion that spans the signal line and extends to above the fixed electrode, and is movable with respect to the fixed electrode, and a fixed portion that is fixed to the fixed electrode across a dielectric layer.

Variable capacitance element

A micro-device includes a movable part, a frame and a connecting part. The movable part has a main portion, a first capacitor electrode and a first driver electrode. The capacitor electrode and the driver electrode have electrode teeth extending from the main portion. The frame includes second capacitor and driver electrodes, where the second capacitor electrode has electrode teeth extending toward the first capacitor electrode, and the second driver electrode has electrode teeth extending toward the first driver electrode. The connecting part connects the movable part to the frame. The first and second capacitor electrodes have their electrode teeth overlapped in their initial position. The movable part is rotatable for varying the extent of the overlapping between the first and second driver electrodes.

Movable micro-device

A variable capacitor is provided which is appropriate for suppressing fluctuation in driving voltage characteristic and for achieving a larger variation ratio of static capacitance. The variable capacitor includes a fixed electrode and a movable electrode. The fixed electrode includes a first opposing face, while the movable electrode includes a second opposing face that faces the first opposing face. The movable electrode further includes a curved portion that protrudes toward the fixed electrode. The variable capacitor also includes a dielectric pattern provided on the first opposing face.

Variable capacitor

In a method for drive controlling a micro machine device including two electrodes opposing each other and a dielectric layer sandwiched therebetween, a control voltage in a rectangular waveform in which positive and negative polarities are alternately inverted is applied between the two electrodes. A current passing through the micro machine device due to the application of the control voltage are detected with respect to positive and negative sides, and parameters related to a capacitance of the micro machine device are acquired with respect to the positive and negative sides on the basis of the detected current. The control voltage is controlled so that the parameters acquired with respect to the positive and negative sides accord with each other. Thus, variation of the capacitance between the positive side and the negative side can be suppressed in switching drive of a variable capacitance device.

Apparatus and method for drive controlling micro machine device

A micro movable device includes a base substrate, a fixed portion bonded to the base substrate, a movable portion having a fixed end connected to the fixed portion and extending along the base substrate, and a piezoelectric drive provided on the movable portion and the fixed portion on a side opposite to the base substrate. The piezoelectric drive has a laminate structure provided by a first electrode film contacting the movable portion and the fixed portion, a second electrode film and a piezoelectric film between the first and the second electrode films. At least one of the movable portion and the fixed portion is provided with a groove extending along the piezoelectric drive.

Micro movable device and method of making the same using wet etching

A capacitor manufacturing method provides variable capacitors whose capacitances remain stable under the influence of temperature change. Such a variable capacitor includes a fixed electrode, a movable electrode film facing the fixed electrode, and an anchor portion that provides partial connection between the fixed electrode and the movable electrode film. For making this variable capacitor, a first electrode is formed to serve as the fixed electrode. Then, an anchor portion is formed on the fixed electrode, and a sacrifice film is formed to cover the fixed electrode but partially expose the anchor portion. A second electrode is formed on the sacrifice film to serve as the movable electrode film, bonded to the anchor portion. Finally, the sacrifice film is removed.

Variable capacitor and method of making the same

A microswitching element includes a base substrate, a fixing portion attached to the base substrate, and a movable portion including a fixed end fixed to the fixing portion. The movable portion is surrounded by the fixing portion via a slit having a pair of closed ends. The movable portion includes a first surface and a second surface. The first surface faces the base substrate, and the second surface is opposite to the first surface. The microswitching element also includes a movable contact portion provided on the second surface of the movable portion, and a pair of fixed contact electrodes each including a contact surface facing the movable contact portion. The fixed contact electrodes are attached to the fixing portion.

Microswitching element

A micro-switching device includes a base substrate and a cantilever fixed to the base substrate via a spacer or anchor portion. The cantilever has an inner surface facing the substrate and an outer surface opposite to the inner surface. A conductive strip is formed on the outer surface of the cantilever. The switching device also includes a pair of stationary electrodes fixed to the base substrate. Each of the electrodes includes a downward contacting part spaced from the conductive strip on the cantilever. As the cantilever bends upward, the conductive strip is brought into contact with the contacting parts of the respective stationary electrodes.

Micro-switching device and method of manufacturing micro-switching device

A lower movable electrode, having line sectionson both ends and a capacitor sectionin the center, and an upper movable electrode, having line sectionson both ends and a capacitor sectionin the center, are placed so that the capacitor sectionsface each other, and drive electrodes of lower-movable-electrode actuatorsdriving the lower movable electrodeand upper-movable-electrode actuatorsdriving the upper movable electrodeare electrically separated from the lower movable electrodeand upper movable electrode. These actuatorstoand/ortomove the lower movable electrodeand/or upper movable electrodeto adjust the distance between both capacitor sections, and control the electrostatic capacity.

Variable capacitor and manufacturing method thereof

The first movable electrode is flat, but the second movable electrode is deformed into a convex shape. A dielectric layer is placed on the facing surface of the second movable electrode. By adjusting a voltage to be applied between the first movable electrode and the second movable electrode, an arbitrary distance is secured between the two electrodes by the electrostatic attractive force generated between the two electrodes, and a desired electrostatic capacitance is obtained. When the distance between the two electrodes is shortened, first, at the center, a part of the first movable electrode and a part of the second movable electrode come into contact with each other with the dielectric layer between them. Then, the first movable electrode and the dielectric layer (second movable electrode) come into contact with each other successively from the contact part towards the periphery side, and the contact area gradually increases.

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Kawasaki, Japan

Masahiko Imai