Abstract:
A pizoelectric filter capable of improving the shielding property and increasing the heat releasing property is provided. The piezoelectric device includes a cover and piezoelectric device chips which are stacked and sealed together. The piezoelectric device also includes first external electrodes exposed at an upper surface of the cover and a grounded second external electrode exposed at the upper surface and a side surface of the cover. Electroconductive bonding materials are disposed between the cover and the piezoelectric device chips and all around an outer edge which connects the cover to the piezoelectric device chips so as to form a seal. The electroconductive bonding materials are also connected to the grounded second external electrode.
Abstract:
A micro electro-mechanical system, which can be stably formed so as to prevent sticking of a movable part and which has a narrow gap, and a method of manufacturing the same are provided. The micro electro-mechanical system includes at least one fixed electrode formed above a principal surface of a semiconductor substrate and at least one movable electrode formed on the principal surface. The at least one movable electrode includes the movable part separated from the principal surface and the at least one fixed electrode. The movable part is movable with respect to the principal surface and the at least one fixed electrode. The method of manufacturing the micro electromechanical system includes a sacrifical film formation step for forming a sacrifical film above the principal surface, an electrode layer formation step for forming an electrode layer above the principal surface so as to cover over the sacrifical film, an etching step for partially etching the electrode layer via a pattern so as to form the at least one electrode and the at least one fixed electrode, a sacrifical film removal step for removing the sacrifical film, and a conducting film formation step for forming a conducting film on surfaces of the at least one electrode and the at least one fixed electrode.
Abstract:
To provide a method for manufacturing a semiconductor device and a semiconductor device manufactured by the method. In the method, a movable portion formed on a semiconductor substrate can be released by etching an insulation layer in a shorter time and more readily controlling the etching amount in a section direction of the insulation layer.A method for manufacturing a semiconductor device 10 includes: a step of forming a structure 30 on an insulation layer 14 formed on a semiconductor substrate 14, the structure including a piezoelectric layer 22, a first electrode 20, and a second electrode 24; a step of exposing a section of the insulation layer 14 by dicing the semiconductor device 10; and a step of removing the insulation layer 14 from the exposed section so as to release a movable portion 30b of the structure 30 while a fixing portion 30a of the structure 30 is fixed on the insulation layer 14.
Abstract:
Thermally induced frequency variations in a micromechanical resonator are actively or passively mitigated by application of a compensating stiffness, or a compressive/tensile strain. Various composition materials may be selected according to their thermal expansion coefficient and used to form resonator components on a substrate. When exposed to temperature variations, the relative expansion of these composition materials creates a compensating stiffness, or a compressive/tensile strain.
Abstract:
A microelectromechanical system switch may include a relatively stiff cantilevered beam coupled, on its free end, to a more compliant or flexible extension. A contact may be positioned at the free end of the cantilevered beam. The extension reduces the actuation voltage that is needed and compensates for the relative stiffness of the cantilevered beam in closing the switch. In opening the switch, the stiffness of the cantilevered beam may advantageously enable quicker operation which may be desirable in higher frequency situations.
Abstract:
A method for the production of a planar structure is disclosed. The method comprises producing on a substrate a plurality of structures of substantially equal height, and there being a space in between the plurality of structures. The method further comprises providing a fill layer of electromagnetic radiation curable material substantially filling the space between the structures. The method further comprises illuminating a portion of the fill layer with electromagnetic radiation, hereby producing a exposed portion and an unexposed portion, the portions being separated by an interface substantially parallel with the first main surface of the substrate. The method further comprises removing the portion above the interface.
Abstract:
Apparatus for housing a micromechanical structure, and a method for producing the housing. The apparatus has a substrate having a main side on which the micromechanical structure is formed, a photo-resist material structure surrounding the micromechanical structure to form a cavity together with the substrate between the substrate and the photo-resist material structure, wherein the cavity separates the micromechanical structure and the photo-resist material structure and has an opening, and a closure for closing the opening to close the cavity.
Abstract:
A method of fabricating micro-mechanical devices. A mesa is etched in a homogeneous wafer. The wafer is bonded to a patterned substrate with the mesa defining device elements suspended above the substrate. A portion of the wafer is removed until a desired device thickness is achieved. Discrete elements of the device are then formed by performing a structural etch on the remaining wafer material.
Abstract:
A piezoelectric filter that includes a first substrate having at least one first piezoelectric resonator disposed on a main surface thereof; a second substrate having at least one second piezoelectric resonator disposed on a main surface thereof. A connection pattern extends around the first piezoelectric resonator and the second piezoelectric resonator and is disposed between the first substrate and the second substrate such that the main surface of the first substrate faces the main surface of the second substrate, and the first piezoelectric resonator is remote from the second piezoelectric resonator. A connecting layer bonds a pad disposed on the main surface of the first substrate to a pad disposed on the main surface of the second substrate, and is electrically connected to the first piezoelectric resonator and the second piezoelectric resonator.
Abstract:
A resonant structure for a micromechanical device includes a beam and at least one mass attached to the beam. The resonant structure is arranged to have a predominantly rotational excitation mode and an excitation plane in which motion of the excited resonant structure predominantly takes place, the at least one mass including a geometry such that none of the principal axes of the rotational inertia tensor of the resonant structure are normal to the excitation plane.