64 results about "Membrane stress" patented technology

An MEMS transducer is constituted of a diaphragm, a plate, a support structure for supporting the diaphragm and the plate with a gap layer surrounded by an interior wall, an electrode film (e.g. a pad conductive film) for covering a contact hole formed in the support structure, and a protective film (e.g. a pad protective film) which is formed on the support structure externally of the interior wall so as to cover the side surface of the electrode film having low chemical stability. The protective film is formed in the limited area including a part of the surface of the electrode film except for its center portion and the surrounding area of the electrode film. This allows the protective film to use materials having high membrane stress such as silicon nitride or silicon nitride oxide.

The invention provides a system and method for determining nonlinear membrane stress. According to the invention, a membrane material is taken as a multilayer board shell structure to perform mechanic modeling so as to define the deflexion, cross section corner, middle plane internal displacement or curvature variation on the middle plane of the multilayer board shell structure as well as nonlinear geometric relationship to describe the deformation of the membrane material. Shape measuring equipment is adopted to measure the deformation of the membrane material caused by membrane stress, and the deformation is represented as the deflexion, cross section slope, middle plane internal displacement or curvature variation of the thin-film material. The finite elements of the multilayer board shell structure are adopted to discrete the geometrical model of a detected object, the measured values of degree of freedom of all or part of finite element nodes are given in a direct measurement or indirect interpolation manner, the least square fitting condition between the deformation generated by membrane stress at the nodes and the measured deformation is created, and the membrane stress is reversely solved through nonlinear iterative computations. As for membrane temperature mismatching stress belonging to part of the membrane stress, the nonlinear temperature mismatching stress of the membrane material with a deformed base body is calculated and considered at the same time under the condition of given temperature variation.

The invention discloses a method used for online measuring the stress gradient of MEMS film, comprising the steps as follows: a round film with center fixed is prepared on a structure layer film; after the round film is released, the round film generates deformation under the stress gradient inside the round film; the displacement of the edge of the round film in the vertical direction is measured by a non-contact phase-shifting typed Mirau interferometer, thus calculating the curvature radius of the round film; and the stress gradient of the film can be calculated by the young modulus and Poisson ratio of the film and the curvature radius of the round film. The measurement method is characterized in that a centrosymmetric round film with the center fixed is used as a testing structure and a choring area is fixedly clamped closely to an ideal state, thus improving the precision of the model; the non-contact optical interference method is used for measurement, thus not affecting testing structure and having good repeatability; the method is suitable for measuring the stress gradient of conductive material and non-conductive material simultaneously; and furthermore, the measurement method has the advantages of simple and convenient operation, high measurement precision, small chip occupying area and the like.

The invention discloses a method for determining a membrane stress value of a periphery clamped circular membrane under the effect of concentrated force. The method is characterized in that the periphery of a circular membrane with a radius a, thickness h, elastic Young's modulus E and Poisson ratio v is fixed and clamped, a cylinder with a zero-friction flat bottom and a radius b is used as a loading shaft, a transverse load F is applied to the center of the circular membrane, the cylinder and the circular membrane are kept on the same axis during loading, alpha=b/a is recorded, and the membrane stress value sigma r at a place r can be accurately determined by using a load measured value F based on the static balance analysis of the axial symmetry circular membrane problem.

The present invention discloses a method for analyzing a crushing property of a composite material coated twelve-rectangular-cross-section thin-walled beam and aims to solve the problem that crushing property analysis of the thin-walled beam cannot be performed by using a finite element method or an experimental method due to a shortage of a geometrical model with a detailed structure in a conceptual design stage of crashworthiness of a car body. The method comprises the steps: 1, deducing an average crushing counter force analytic expression of a non composite material coated hollow twelve-rectangular thin-walled beam; 2, simplifying a stress-strain curve of a fiber reinforced composite material, i.e. in the stretching process, a stress-strain relationship is shown as linearity until the fiber reinforced composite material is broken, and in the compressing process, the stress is kept at a certain level without a change after yielding; 3, calculating a plastic limit bending moment and a limit yielding membrane stress of the fiber reinforced composite material coated twelve-rectangular-cross-section thin-walled beam; 4, correcting an effective crushing distance and a final folding angle of the fiber reinforced composite material coated twelve-rectangular-cross-section thin-walled beam; and 5, deducing the average crushing counter force analytic expression of the fiber reinforced composite material coated twelve-rectangular-cross-section thin-walled beam.

The invention relates to a simplified assessment method for defects of a welding joint area at a piping safety end of a pressure vessel of an AP1000 nuclear reactor. The method comprises the following steps of: characterizing the detected dimension of a circumferential inner surface defect, and determining a defect depth a and a defect length l; calculating primary membrane stress sigma m which is vertical to a defect surface at the position of the circumferential inner surface defect in absence of the defect under an assessment working condition; calculating the relation of primary bending stress sigma b which is vertical to the defect surface at the position of the circumferential inner surface defect in absence of the defect and an extra bending moment M which is borne by the safety end through three-dimensional finite element analysis; determining the primary bending stress sigma b which corresponds to a resultant bending moment Mt according to the resultant bending moment Mt under the assessment working condition; calculating the rheological stress sigma f of a material in the welding joint area, and calculating a stress ratio SR which is equal to (sigma m+ sigma b)/ sigma f; calculating the relation of the stress ratio, a nominal defect length and a nominal permitted defect depth according to a three-dimensional finite element model; and judging whether the defect depth a is less than or equal to the permitted defect depth a or not.

The invention relates to an MEMS (micro electro mechanical systems) testing technique, in particular to a membrane stress testing device and method. The device comprises at least two fixing terminals in symmetrical design; each fixing terminal is connected with a fixing beam; the other free end of each fixing beam is connected with one end of a cantilever beam through a fixing beam connecting neck at an included angle; a pointer beam is clamped between the other ends of the cantilever beams through two cantilever beam connecting necks; the pointer beam is close to one cantilever beam and far away from the other cantilever beam; the pointer beam points to a scale; the scale comprises a sacrificial layer formed on a substrate and a membrane to be tested, formed on the sacrificial layer and is provided with a comb-tooth structure used with the pointer beam to read a swing value of the pointer beam. The method is applied to the device; small displacement of the fixing beams is secondarily amplified into swing displacement of the pointer beam through the cantilever beams, a rotating arm and the pointer beam, the swing displacement is acquired directly through the scale, and residual stress of the membrane is solved through a linear-elastic theory equation.

The invention supplies a real-time measurement device and method of high-accuracy membrane stress that comprises the He-Ne laser, reflector, light-sensitive detector, A/D data acquisition card and computer. The whole device can be mounted on any coater conveniently, the He-Ne laser, reflector, light-sensitive detector, A/D data acquisition card and computer are out of the coater, and the laser beam enters the coated room via observation window of the coater and irradiated to substrate by adjusting of the reflector, the reflected beam is adjusted by the reflector and out from the observation window, the light-sensitive detector detects the deflection shift of the reflected beam, the data acquisition card collects the analog signal of the light-sensitive detector and transfers the analog signal to digital signal which is sent to computer. The stress variation of film can be real-time monitored by the process of signal. The invention characterized in that the structure is simple, the accuracy is high, data processing is easy, and the compatibility with coater is strong.

The invention discloses a light beam array membrane stress measuring device, which comprises a multi-light-beam pattern generator and a light bema position detector. The multi-light-beam pattern generator comprises a laser device, an inverted telescopic collimation optical system, a beam splitter and a collimation lens. The beam splitter can generate a light beam array, and the light beam array consists of a plurality of mutually parallel single parallel light beams which are arrayed. Accordingly, the light beam array membrane stress measuring device can measure stress distribution of a micro-domain membrane, eliminates stress measurement errors caused by environmental vibration interferences, and improves membrane stress measurement precision.

The invention belongs to the field of Micro-Electro-Mechanical System (MEMS), more specifically, the invention relates to a cantilever beam type membrane stress power generation structure, which comprises a frame type substrate, wherein a silicon cantilever beam suspended in the frame type substrate is positioned on a beam facing an opening of the frame type substrate, the free end of the silicon cantilever beam is fixedly provided with a mass block, a silicon dioxide insulation layer is also positioned above the beam facing the opening of the frame type substrate, a bottom electrode layer is positioned on the silicon dioxide insulation layer, a strip bottom electrode layer positioned above the silicon cantilever beam extends on the bottom electrode layer in the direction towards the opening of the frame type substrate, a PZT piezoelectric layer is positioned on the mass block, a strip PZT piezoelectric layer positioned above the strip bottom electrode layer extends on the PZT piezoelectric layer in the direction towards the silicon dioxide insulation layer, and a top electrode layer is positioned above the strip PZT piezoelectric layer. When the system is in a vibration environment, the vibration in the external environment can be transferred to the system, vibration and bending deformation of the silicon cantilever beam are caused, mechanical energy is stored in the silicon cantilever beam, thereby, the piezoelectric layer is stretched and contracted and an electrical signal is generated, and the conversion of mechanical energy to electrical energy is realized.

The invention relates to a measuring method and measuring device for membrane stress and belongs to the technical field of measurement. In the measuring method and the measuring device for membrane stress, at least two laser beams are projected to a membrane to be measured by a laser transmitter, so that after a detector receives reflection light reflected by the membrane, the membrane stress can be corrected according to difference values delta alpha of reflection angles of multiple reflection light, so that an error in measurement can be lowered greatly; besides, the measuring device also includes a revolving mirror group which can project over-ranging reflection light to a laser receiving unit, thereby enlarging the measuring range, and further improving the precision of a measuring result; the measuring device for the membrane stress provided by the invention is simple in structure, low in cost,simple and convenient in application manner of the measuring method and wider in application range.

A vent assisted single-ply roof system including an augmented design that incorporates mechanical fasteners, insulation bonding adhesives and membrane bonding adhesives in the turbulent wind vortex areas along the perimeter of the deck as determined by ASCE 7 calculations. Coupled with roof vents for equalizing the pressure under a loose laid membrane in the field-of-roof area outside the turbulent wind vortex areas to reduce membrane stress and resist wind uplift pressures during high wind events.

Provided is a semiconductor resistor circuit with high accuracy. An insulating film is formed to cover a plurality of resistor groups having upper portions covered with a plurality of metal wirings. The insulating film has a membrane stress that is higher than that of the metal wirings, and is formed between the metal wirings and the resistor groups.

The invention relates to a testing system for identifying limp of dairy cattle early. The testing system comprises a 3D membrane stress plate and a ramp which are arranged in sequence, wherein guide bars are respectively arranged on two sides of the 3D membrane stress plate and the ramp, and photoelectric sensors are arranged on the guide bars. The testing system further comprises a counter connected with the photoelectric sensors. An anti-slip antiseptic rubber blanket is laid on the 3D membrane stress plate, and the counter and the 3D membrane stress plate are connected with a data acquisition and record device. The testing system has the advantages that the 3D membrane stress plate serves as a test sensor to pick up acting force of dairy cattle to the ground, the dairy cattle can pass through a testing channel without interference during testing, and the testing system is simple, convenient and feasible. A test method has no special requirements for environments and light. A large amount of data information can be acquired by the membrane stress plate, real conditions of the acting force of dairy cattle to the ground during walking can be reflected accurately, and therefore, operators can identify whether dairy cattle limp or which legs of dairy cattle limp early through the data analysis result.

The invention discloses a thin film transistor, a fabrication method thereof, a display substrate and a display device. The thin film transistor comprises a substrate, an active layer, a grid, a grid insulation layer, an interlayer insulation layer, a source and a drain, wherein the active layer is arranged on the substrate, the grid insulation layer is arranged between the grid and the active layer, the projection of the grid on the active layer is overlapped with at least one part of a channel region of the active layer, the interlayer insulation layer is arranged at one side, far away from the substrate, of the active layer and comprises an organic transparent material, and the source and the drain are arranged at one side, far away the grid insulation layer, of the interlayer insulation layer and are connected with the active layer through a via hole. The thin film transistor has at least one of the following advantages that the membrane stress of the interlayer insulation layer can be reduced, a glass warping phenomenon is improved, the capacitance coupling effect between the source-drain and the grid is reduced, and the light transmittance is effectively improved.

The invention relates to a method for preparing a target for a copper conductor of a thin film transistor (TFT)-liquid crystal display (LCD) array substrate, and the target. The method for preparing the target for the copper conductor for the TFT-LCD array substrate comprises the following steps of: providing copper powder, and a discharge plasma activated sintering device; and 2, adding the copper powder into the discharge plasma activated sintering device and sintering to prepare the target for the copper conductor of the TFT-LCD array substrate. According to the method for preparing the target for the copper conductor of the TFT-LCD array substrate, the copper powder is sintered into the target by the discharge plasma activated sintering device; the method is simple in process and high efficiency; and the crystal orientation of the target can be effectively controlled, and the performance of the target is improved, so that the copper conductor which is prepared by using the target is low in electrical resistivity, membrane stress and surface roughness.

The invention relates to a landfill impermeable membrane stress relief structure using rubber airbags, and belongs to the technical field of environmental protection. A liner is arranged on a slope ofa refuse landfill; the liner specifically consists of an impermeable membrane in middle, and geofabrics on two sides of the impermeable membrane; anchoring areas for fixing the liner are arranged atthe top end of the slope and the upper part of each slope section; the anchoring areas comprise anchoring grooves and groove outer side platforms; the liner is overturned in the anchoring grooves; concrete anchoring blocks are cast above the liner in the anchoring grooves; volume adjusting objects are arranged between the groove outer side platforms and the liner or between the concrete anchoringblocks and the liner; and the volume adjusting objects are carbon dioxide cylindrical airbags.

This sintered body, which contains zinc (Zn), tin (Sn) and/or indium (In), magnesium (Mg), and oxygen (O), is an oxide sintered body characterized by having a total content of Sn and/or In in terms of SnO2 and/or In2O3 of 10-90 mol%, having an Mg content in terms of MgF2 of 15-50 mol% when the ratio of the number of Sn and/or In atoms to the number of Zn atoms is no greater than 1, and having an Mg content in terms of MgF2 of 1-40 mol% when the ratio of the number of Sn and/or In atoms to the number of Zn atoms is at least 1. The sintered body can form an amorphous film by means of a sputtering method or an ion plating method, and so has a superior effect in being able to suppress the occurrence of cracking or peeling of the film resulting from membrane stress. The thin film of the present invention is particularly useful as an optical thin film forming a protective layer for an optical information recording medium, an organic EL television thin film, and a transparent electrode thin film.