Class / Patent application number | Description | Number of patent applications / Date published |
073726000 | Strain gauge | 81 |
20080202249 | Semiconductor sensor and method of manufacturing the same - A semiconductor pressure sensing apparatus includes a metallic stem having a diaphragm and a semiconductor sensor bonded to the diaphragm. The semiconductor sensor includes a gauge section and first and second bonding pads. The gauge section is configured to be deformed according to a deformation of the diaphragm. The first and second bonding pads are respectively connected to different positions of the gauge section so that an electrical resistance between the first and second bonding pads can change with a change in the deformation of the diaphragm. The gauge section is formed to a semiconductor layer of an silicon-on-insulator substrate. The semiconductor sensor is directly bonded to the diaphragm by activating contact surfaces between the semiconductor sensor and the diaphragm. | 08-28-2008 |
20080223142 | SENSOR AND MANUFACTURING METHOD OF SENSOR - The following abstract will replace all prior versions of the abstract in the application: | 09-18-2008 |
20080264172 | PRESSURE SENSOR - A pressure sensor includes: a diaphragm having a pressure-receiving portion receiving a pressure and a thick portion adjacent to the pressure-receiving portion; and a pressure sensitive element having a first and a second ends facing each other. The pressure sensitive element extends in a direction intersecting the thick portion and the first end of the pressure sensitive element is bonded to a pressure-receiving surface of the pressure-receiving portion, and a central portion of a portion at which the pressure-receiving portion and the first end are bonded is positioned at a side closer to the second end of the pressure sensitive element than a center of the pressure-receiving portion. | 10-30-2008 |
20090114030 | DIE SCALE STRAIN GAUGE - A chip with resistive, metallic strain gauges distributed on surfaces on and buried within the chip. Also, vertically arranged vias and vertical thin film resistive strain gauges are described. The resistive strain gauges can be multiplexed wherein strain can be measured across the topology of the chip in each of the top, bottom and buried layers and any vertical strain. The resistive strain gauges may be in serpentine patterns and may be arranged on via or on vertical edges of grooves that extend from an upper or lower surface of the chip to buried layers. In this fashion, the distributed strain gauges may be used to map the strain throughout the body of a chip. A Kelvin bridge may be used to measure the strain, but other such measuring techniques and devices may be used. | 05-07-2009 |
20090145235 | LOW TCR NANOCOMPOSITE STRAIN GAGES - A high temperature thin film strain gage sensor capable of functioning at temperatures above 1400° C. The sensor contains a substrate, a nanocomposite film comprised of an indium tin oxide alloy, zinc oxide doped with alumina or other oxide semiconductor and a refractory metal selected from the group consisting of Pt, Pd, Rh, Ni, W, Ir, NiCrAlY and NiCoCrAlY deposited onto the substrate to form an active strain element. The strain element being responsive to an applied force. | 06-11-2009 |
20090308171 | External Pressure Measuring Device - An external pressure measuring device having a base and a tubing system bent with various radii. Pressure inside the bent tubing causes the tubing to move in such a way that can be measured and can provide an indication of internal pressure. | 12-17-2009 |
20100031752 | PRESSURE SENSOR WITH RESISTANCE STRAIN GAGES - The invention relates to pressure sensors that are micromachined using microelectronics technologies. The sensor provided by the invention comprises a cavity (V) hermetically sealed on one side by a silicon substrate ( | 02-11-2010 |
20100186517 | METHOD AND SYSTEM FOR DETECTING AIR PRESSURE NEUTRALITY IN AIR CONTAINMENT ZONES - An airflow detecting system includes a tubular structure having an inner surface defining an interior of the tubular structure, one open end and an opposite open end. The tubular structure is configured to receive and expel air through both the one end and the opposite end. The system further includes a flap connected to the inner surface of the tubular structure by a hinge. The flap is configured to impede airflow within the interior of the tubular structure upon the application of differential pressure across the two ends of the tubular structure. The system further includes a device attached to the flap in a position in which the device spans the hinge. The device is configured to measure a parameter associated with the movement of the flap in response to airflow within the interior of the tubular structure. Other embodiments and methods are further disclosed. | 07-29-2010 |
20100319461 | MULTIPURPOSE TRANSDUCER FOR AN APPLIANCE USING WATER - A multipurpose transducer for an appliance using water, like a washing machine, a dishwasher or a hot-water tank converts physical parameters like water temperature, cleanness and pressure in said appliance into electric signals. It is provided with a temperature transducer (TT), a turbidity transducer (TurbT) and a pressure transducer (PT), all of them being fixed on an electrically insulating mounting support (MS). The pressure transducer (PT) is made as an uncompensated strain gauge in a thick film technology. The temperature transducer (TT) made as a termistor is also manufactured in the thick film technology. The multipurpose transducer (MPT) of the invention requires less work steps to be manufactured, mounted and connected in the appliance of said type than earlier transducers. | 12-23-2010 |
20140096615 | PRESSURE TRANSDUCER USING CERAMIC DIAPHRAGM - A pressure transducer using a ceramic diaphragm which is not easily damaged so that there is no risk of leakage of a target medium to be measured, having a superior mass-production capability and a reduced volume and enabling low-price by simplifying a flexible cable and a printed circuit board (PCB) to connect the transducer and a signal processing chip. The pressure transducer includes the ceramic diaphragm formed as a rectangular planar ceramic diaphragm and having a surface having formed thereon a pattern made of an electrically conductive material and strain gages; a base plate configured to face the surface of the ceramic diaphragm having formed thereon the pattern; and an adhesive layer configured to be formed along edges of a contacting surface of the ceramic diaphragm and the base plate so as to bond the ceramic diaphragm and the base plate and form a space for the strain gages. | 04-10-2014 |
20140260649 | LOW PROFILE PRESSURE SENSOR - A pressure sensor | 09-18-2014 |
20150128714 | RUGGEDIZED PRESSURE TRANSDUCER WITH INTEGRATED WIRELESS ANTENNA AND RECHARGABLE BATTERY SYSTEM - A pressure transducer for a hammer union installation includes a lower body capable of withstanding the stresses of the hammer union installation. The lower body includes a cylindrical wall, a diaphragm, and a pressure port for exposing the diaphragm to pressure. The pressure transducer also includes one or more transducer elements mounted on the diaphragm that are operable to provide a signal related to pressure. A cap is received by the cylindrical wall and is slidable along the wall. The cap includes comprising an antenna for transmitting the signal. A spring is arranged in the lower body for dampening forces applied to the cap. | 05-14-2015 |
20150323404 | PRESSURE SENSOR - A pressure sensor has a circuit arrangement supported by a sensor body and includes: a first electrical-circuit pattern, having respective tracks made of electrically conductive material deposited on a first face of an electrically insulating material, a second electrical-circuit pattern having respective tracks made of electrically conductive material deposited on a region of the second face of the material, and connection means, which electrically connect the first electrical-circuit pattern to the second electrical-circuit pattern. Tracks of the second electrical-circuit pattern have at least one first track defining a plurality of first pads and one second track defining a plurality of second pads, for connection of a first terminal and of a second terminal of the second circuit component, respectively. The first and second track are prearranged so that the first terminal and the second terminal can be connected to any one of the first pads and the second pads. | 11-12-2015 |
20150369680 | DOUBLE DIAPHRAGM TYPE PRESSURE SENSOR - A double diaphragm type pressure sensor includes a metal container having a concave portion; a pressure sensor unit mounted on a bottom of the container; a metal diaphragm airtightly bonded to an opening portion of the concave portion of the container; a pressure transmission medium filling a space formed by the metal diaphragm and the concave portion of the container; and a metal terminal penetrating the bottom of the container and being electrically insulated from the container. | 12-24-2015 |
20150377729 | PRESSURE DETECTING DEVICE - A pressure detecting device is mounted in a measurement target and instrument includes a strain inducer to which pressure of a pressure medium is applied and which generates strain in accordance with the pressure and a strain detecting element that is bonded onto a surface opposite to a pressure receiving surface of the strain inducer, in which the strain detecting element includes one or multiple central strain resistant bridges which are arranged at a central portion of the strain detecting element in a bonded surface direction, and one or multiple outer peripheral strain resistant bridges which are arranged at an outer periphery, and in which, for example, deformation of the strain detecting element caused by an external force when being screw-fixed to the measurement target instrument is obtained through the multiple strain resistant bridges. An error of detection pressure caused by the deformation in a pressure value detected through the central strain resistant bridge is corrected. | 12-31-2015 |
20160202136 | SENSOR MODULE AND METHOD FOR PRODUCING SENSOR MODULE | 07-14-2016 |
20160252418 | MICROFUSED SILICON STRAIN GAUGE (MSG) PRESSURE SENSOR PACKAGE | 09-01-2016 |
073727000 | Piezoresistive | 64 |
20080223143 | PRESSURE SENSOR HAVING A HIGH FULL-SCALE VALUE WITH PACKAGE THEREOF - A pressure sensor including a pressure-sensor element having a monolithic body of semiconductor material, and a first main face and a second main face acting on which is a stress resulting from a pressure, the value of which is to be determined; and a package enclosing the pressure-sensor element. The package has an inner chamber containing liquid material, and the pressure-sensor element is arranged within the inner chamber in such a manner that the first and second main faces are both in contact with the liquid material. In particular, the liquid material is a silicone gel. | 09-18-2008 |
20080236292 | Sensor element and sensor assembly provided with a casing - A sensor element having a sensitive sensor portion on an upper side of a substrate layer. The upper side of the substrate layer is provided with a recess on the periphery of the sensitive sensor portion. The recess provides mechanical isolation or decoupling of the sensitive sensor portion, as a result of which external forces do not cause stress in the sensitive sensor portion. In addition, a sensor assembly is described which is provided with at least one sensor element and a casing. | 10-02-2008 |
20080264173 | Sensor Unit - The invention relates to a sensor unit for measuring a measurable variable, especially in an aggressive medium. Said sensor unit comprises a sensor which is disposed in a sensor casing and is provided with a sensor zone located on a base. In order to detect the measurable variable in the sensor zone, a measuring hole which allows the medium to advance directly to the sensor zone is provided in the sensor casing. A side of the sensor zone that faces away from the measuring hole is equipped with a measuring surface which encompasses measuring electronics. An electrical feeder is provided on the sensor in order to transmit a sensor signal generated by the measuring electronics. The sensor is sealingly arranged on a sealing surface located on the sensor casing in such a way that the measuring surface is isolated from the medium. A mechanism is provided by means of a which the sensor can be disconnected from thermally and/or mechanically induced changes in the sensor casing. There also is a probe comprising a sensor unit, as well as an internal combustion engine, a hydraulic or pneumatic tool, and an air conditioner encompassing a sensor unit. | 10-30-2008 |
20090007680 | High pressure transducer having an H shaped cross-section - A high pressure transducer has an H shaped cross-section with a center arm of the H having a top and bottom surface with the top surface of the H accommodating four strain gauges. Two strain gauges are located at the center of the top portion of the center arm of the H and are positive strain gauges, while two strain gauges are located near the periphery of the center arm of the gauge. The bottom surface of the center arm of the gauge has an active area of a smaller diameter than the circular diameter of the center arm portion of the transducer. The smaller active area is surrounded by a thicker stepped area which surrounds an active area on the pressure side of the H shaped member. The surrounding stepped area enables one to position the two negative strain gauges on the opposite surface of the center arm and near the periphery to thereby cause the negative gauges to respond to a negative stresses and therefore to enable one to provide a full Wheatstone bridge which includes the two positive strain gauges located at the center of the center arm of the H and the two negative peripheral gauges. | 01-08-2009 |
20090007681 | SMALL GAUGE PRESSURE SENSOR USING WAFER BONDING AND ELECTROCHEMICAL ETCH STOPPING - A gauge pressure sensor apparatus and a method of forming the same. A constraint wafer can be partially etched to set the diaphragm size, followed by bonding to a top wafer. The thickness of the top wafer is either the desired diaphragm thickness or is thinned to the desired thickness after bonding. The bonding of top wafer and constraint wafer enables electrochemical etch stopping. This allows the media conduit to be etched through the back of the constraint wafer and an electrical signal produced when the etching reaches the diaphragm. The process prevents the diaphragm from being over-etched. The invention allows the die size to be smaller than die where the diaphragm size is set by etching from the back side. | 01-08-2009 |
20090007682 | High pressure transducer having an H shaped cross-section - A high pressure transducer has an H shaped cross-section with a center arm of the H having a top and bottom surface with the top surface of the H accommodating four strain gauges. Two strain gauges are located at the center of the top portion of the center arm of the H and are positive strain gauges, while two strain gauges are located near the periphery of the center arm of the gauge. The bottom surface of the center arm of the gauge has an active area of a smaller diameter than the circular diameter of the center arm portion of the transducer. The smaller active area is surrounded by a thicker stepped area which surrounds an active area on the pressure side of the H shaped member. The surrounding stepped area enables one to position the two negative strain gauges on the opposite surface of the center arm and near the periphery to thereby cause the negative gauges to respond to a negative stresses and therefore to enable one to provide a full Wheatstone bridge which includes the two positive strain gauges located at the center of the center arm of the H and the two negative peripheral gauges. | 01-08-2009 |
20090013793 | PRESSURE SENSOR FOR MEASURING BLOOD PRESSURE AND METHOD OF FABRICATING THE SAME - A pressure sensor includes at least one cantilever formed on an upper surface of a silicon substrate, a piezoresistor formed on a fixed end of the cantilever, and a metal wire and an electrode pad connected to both ends of the piezoresistor, wherein a stopper that limits a deformation of a free end of the cantilever is formed below the cantilever. | 01-15-2009 |
20090031818 | PRESSURE SENSOR - Various embodiments and methods relating to a pressure sensor having a flexure supported piezo resistive sensing element are disclosed | 02-05-2009 |
20090100936 | Pressure sensor - A pressure sensor is provided. The pressure sensor includes a sensing element, a case, a line element, an insect entering restriction element. The case has a space for receiving the sensing element. The case includes a pressure introduction passage, which is in communication with the space to introduce a pressure medium into the sensing element. The line element has a first portion electrically connected with the sensing element and a second portion to be electrically connected to an external element. The insect entering restriction element extends across a path on the exterior surface of the case, the path interconnecting between the second portion of the line element and the open end of pressure introduction passage. | 04-23-2009 |
20090139338 | Silicon sensing structure to detect through-plane motion in a plane of material with thermal expansion substantially different from that of silicon - A pressure transducer is provided that has a transducer body with a rim, a diaphragm that deflects in response to pressure and a sensor bonded to the diaphragm at the rim and at a center of the diaphragm. The sensor detects deflection of the metal diaphragm. The sensor and diaphragm are made of different materials. A thermal expansion difference between the sensor and the diaphragm is accommodated by flexures in the sensor that accept relative motion in a radial direction of the metal diaphragm with little effect on a sensitivity of the silicon structure to motion in an axial direction of the diaphragm. | 06-04-2009 |
20090139339 | Pressure transducer employing a micro-filter and emulating an infinite tube pressure transducer - A pressure transducer for measuring pressures in high temperature environments employs a tube which is terminated at one end by an acoustic micro-filter. The acoustic filter or micro-filter has a plurality of apertures extending from one end to the other end, each aperture is of a small diameter as compared to the diameter of the transducer and the damper operates to absorb acoustic waves impinging on it with limited or no reflection. Mounted to the tube is a pressure transducer with a diaphragm flush with the inner wall of the tube. The tube is mounted in an aperture in a casing of a gas turbine operating at a high temperature. The hot gases propagate through the tube where the pressure of the gases are measured by the transducer coupled to the tube and where the acoustic filter operates to absorb acoustic waves impinging on it with little or no reflection, therefore enabling the pressure transducer to be mainly responsive to high frequency waves associated with the gas turbine operation. | 06-04-2009 |
20090235753 | PRESSURE SENSOR MODULE - A pressure sensor module of the invention includes a pressure sensor and a laminar substrate. Electrodes are arranged in the vicinity of a diaphragm portion of the pressure sensor. In the laminar substrate, a plurality of substrates are laminated, and the laminar substrate incorporates the pressure sensor. One face of the diaphragm portion is exposed by a space portion. According to the invention, it is possible to provide a pressure sensor module which facilitates smaller and thinner sizes, and which enables high-density packaging. | 09-24-2009 |
20090314095 | PRESSURE SENSING DEVICE PACKAGE AND MANUFACTURING METHOD THEREOF - A pressure sensing device package including a circuit substrate, a pressure sensing device, a molding compound, and a flexible protection layer is provided. The circuit substrate has an opening. The pressure sensing device is flip chip bonded to the circuit substrate and has a sensing region facing toward the opening. The molding compound encapsulates the pressure sensing device but exposes the sensing region. The flexible protection layer is disposed on the sensing region and exposed by the opening of the circuit substrate. | 12-24-2009 |
20100050777 | RESISTIVE CONTACT SENSORS FOR LARGE BLADE AND AIRFOIL PRESSURE AND FLOW SEPARATION MEASUREMENTS - A fluid dynamic polymer-based contact sensor measures ambient pressure based on the resistivity changes across the sensor under different ambient pressures. The pressure sensor may applied to airfoil structures such as wind turbine blades without impacting the blade structure and fluid dynamic characteristics. The sensor may also be applied to fluid measurements. The pressure measurements are used to measure blade performance with high fidelity. The pressure measurements are transmitted to processing to determine blade characteristics and environment including flow separation, stagnation point, angle of attack, lift and drag and wind speed. Further processing of the pressure distribution may identify wind shear, up-flow and yaw error. | 03-04-2010 |
20100077863 | DIAPHRAGM STRUCTURE AND MEMS DEVICE - A diaphragm structure for a MEMS device includes a through-hole formed so as to penetrate from an upper surface to a bottom surface of a substrate; and a vibrating electrode film formed on the upper surface of the substrate so as to cover the through-hole. An opening shape of the through-hole in the upper surface of the substrate is substantially hexagonal. | 04-01-2010 |
20100107773 | METHOD AND APPARATUS FOR PREVENTING CATASTROPHIC CONTACT FAILURE IN ULTRA HIGH TEMPERATURE PIEZORESISTIVE SENSORS AND TRANSDUCERS - A piezoresistive sensor device and a method for making a piezoresistive device are disclosed. The sensor device comprises a silicon wafer having piezoresistive elements and contacts in electrical communication with the elements. The sensor device further comprises a contact glass coupled to the silicon wafer and having apertures aligned with the contacts. The sensor device also comprises a non-conductive frit for mounting the contact glass to a header glass, and a conductive non-lead glass frit disposed in the apertures and in electrical communication with the contacts. The method for making a piezoresistive sensor device, comprises bonding a contact glass to a silicon wafer such that apertures in the glass line up with contacts on the wafer, and filling the apertures with a non-lead glass frit such that the frit is in electrical communication with the contacts. The use of a lead free glass frit prevents catastrophic failure of the piezoresistive sensor and associated transducer in ultra high temperature applications. | 05-06-2010 |
20100122581 | Flexible transducer structures - A novel flexible transducer structure is suitable for attaching to curved surface such as the leading edge of an aircraft wing. The structure comprises a thin flexible sheet of an insulating material with a leadless transducer secured to the sheet. The sheet is then placed over the curved surface and assumes the curvature of the surface. The transducer secured to the sheet provides an output of pressure according the pressure exerted on the sheet. The sheet basically is fabricated from a thin material such as Kapton and is flexible so as to assume the curvature of the surface with the transducer being exposed to pressure applied to the curved surface. The sensor in conjunction with the flexible sheet allows pressure to be measured without disturbing the air flow patterns of the measuring surfaces and because of its construction, is moisture resistant over a large variety of atmospheric conditions. | 05-20-2010 |
20100154553 | PRESSURE GAUGE - A pressure/vacuum sensor and method, comprising: driving a MEMS piezoresistive resonator ( | 06-24-2010 |
20100175482 | PRESSURE TRANSDUCER EMPLOYING A MICRO-FILTER AND EMULATING AN INFINITE TUBE PRESSURE TRANSDUCER - It is an objective of the present invention to provide a pressure transducer assembly for measuring pressures in high temperature environments that employs an elongated tube which is terminated at one end by an acoustic micro-filter. The micro-filter has a plurality of apertures extending from one end to the other end, each aperture is of a small diameter as compared to the diameter of the transducer and the damper operates to absorb acoustic waves impinging on it with limited or no reflection. To improve the absorption of acoustic waves, the elongated tube may be tapered and/or mounted to a support block and further convoluted to reduce the overall size and mass of the device. A pressure transducer with a diaphragm flush may be mounted to the elongated tube and extend through to the inner wall of the tube. Hot gases propagate through the elongated tube and their corresponding pressures are measured by the transducer. The acoustic filter operates to absorb acoustic waves resultant from the hot gases, therefore enabling the pressure transducer to be mainly responsive to high frequency waves associated with the gas turbine operation. | 07-15-2010 |
20100180688 | MEDIA ISOLATED PRESSURE TRANSDUCER HAVING BOSS COMPRISING SINGLE METAL DIAPHRAGM - A pressure sensor for sensing a pressure of a fluid includes a monolithic metal including substrate having a substantially planar top side, wherein the metallic comprising substrate includes s a relatively thick boss near a center of the substrate and a thinned sensing portion that is elastically deformable and pressure-sensitive positioned radially outward from the boss. At least one dielectric layer is on the top side of the substrate. A plurality of piezoresistors are on the dielectric layer, wherein the piezoresistors are positioned over the thinned diaphragm portion. At least one overglaze layer is over the conductor layer that provides apertures for electrically contacting the plurality of piezoresistors. A sensing system includes a housing including at least a first port for coupling to a fluid for measurement of a pressure of the fluid and at least one sensor in the housing including a pressure sensor according to an embodiment of the invention. | 07-22-2010 |
20100224004 | MEDIA-COMPATIBLE ELECTRICALLY ISOLATED PRESSURE SENSOR FOR HIGH TEMPERATURE APPLICATIONS - A pressure sensor is described with sensing elements electrically and physically isolated from a pressurized medium. An absolute pressure sensor has a reference cavity, which can be at a vacuum or zero pressure, enclosing the sensing elements. The reference cavity is formed by bonding a recessed cap wafer with a gauge wafer having a micromachined diaphragm. Sensing elements are disposed on a first side of the diaphragm. The pressurized medium accesses a second side of the diaphragm opposite to the first side where the sensing elements are disposed. A spacer wafer may be used for structural support and stress relief of the gauge wafer. In one embodiment, vertical through-wafer conductive vias are used to bring out electrical connections from the sensing elements to outside the reference cavity. In an alternative embodiment, peripheral bond pads on the gauge wafer are used to bring out electrical connections from the sensing elements to outside the reference cavity. In various embodiments, a regular silicon-on-insulator wafer or a double silicon-on-insulator wafer may be used as the gauge wafer, and appropriate micromachining steps are adopted to define the diaphragm. A layer of corrosion resistant material is deposited on the surface of the diaphragm that is accessed by the pressurized medium. | 09-09-2010 |
20100242618 | SEMICONDUCTOR PRESSURE SENSOR AND METHOD OF PRODUCING THE SAME - A diaphragm made of a polysilicon film is provided above a first main surface of a silicon substrate. Four gauge resistors are provided on the top face of the diaphragm. A through hole for exposing the bottom face of the diaphragm is formed in the silicon substrate. An anchor portion for mounting the diaphragm on the silicon substrate is provided between the diaphragm and the silicon substrate in a manner surrounding circumferentially an opening end of the through hole located at the side facing the first main surface. Accordingly, a semiconductor pressure sensor having a diaphragm of reduced and less varied thickness can be obtained. | 09-30-2010 |
20100251826 | MICRO PIEZORESISTIVE PRESSURE SENSOR AND MANUFACTURING METHOD THEREOF - A micro semiconductor-type pressure sensor and a manufacturing method thereof are provided. The micro semi-conductor-type pressure sensor is implemented by etching a cavity-formation region of a substrate to form a plurality of trenches, oxidizing the plurality of trenches through a thermal oxidation process to form a cavity-formation oxide layer, forming a membrane-formation material layer on upper portions of the cavity-formation oxide layer and the substrate, forming a plurality of etching holes in the membrane-formation material layer, removing the cavity-formation oxide layer through the plurality of etching holes to form a cavity buried in the substrate, forming a membrane reinforcing layer on an upper portion of the membrane-formation material layer to form a membrane for closing the cavity, and forming sensitive films made of a piezoresisive material on an upper portion of the membrane. | 10-07-2010 |
20100257938 | Flat planner pressure transducer - There is disclosed flat planar pressure transducer which comprises a planar insulative substrate of a rectangular configuration. Disposed on the substrate is an array of conductive areas which extend from a contact terminal area of said substrate to an end of the substrate. There is a leadless sensor module positioned at said contact terminal area, with the contacts of said leadless sensor contacting contact terminals of said contact terminal area. The leadless sensor is enclosed by an enclosure which is coupled to the substrate and surrounds the sensor. The enclosure has a screen positioned on the top surface to prevent particles from entering or damaging the leadless sensor. The above-noted structure forms a very flat, compact pressure transducer which can be utilized in lieu of flex circuit type devices and provides greater mechanical stability as well as a more accurate output. | 10-14-2010 |
20110023618 | LOW PRESSURE SENSOR DEVICE WITH HIGH ACCURACY AND HIGH SENSITIVITY - Pressure non-linearity in a low pressure sensor device formed from a silicon diaphragm with an embedded piezoresistive transducer is reduced by using a shallow boss or thin stiffener on an ultra-thin diaphragm while the pressure sensitivity of the device is increased with corner trenches. | 02-03-2011 |
20110048139 | MICRO-DEFORMABLE PIEZORESISTIVE MATERIAL AND MANUFACTURING METHOD THEREOF AND PRESSURE SENSOR USING THE SAME - A micro-deformable piezoresistive material is provided, including a hard plastic body, a micro-deformable rough texture surface, and a plurality of conductive particles. The micro-deformable rough texture surface is formed on a side of the hard plastic body, wherein the maximum deformation of the rough texture surface is far less than the thickness of the hard plastic body. Additionally, the conductive particles are evenly dispersed in the plastic body. | 03-03-2011 |
20110072906 | SENSOR SYSTEM AND METHOD FOR MANUFACTURING A SENSOR SYSTEM - A sensor system, in particular a pressure sensor system, having a substrate having a main extension plane, the substrate having at least one trench on a first side, and the trench being provided to produce a diaphragm area on a second side of the substrate diametrically opposite to the first side perpendicularly to the main extension plane, and a decoupling element further being integrated in the material of the diaphragm area. | 03-31-2011 |
20110126634 | FLAT PLANAR PRESSURE TRANSDUCER - There is disclosed a flat planar pressure transducer which comprises a planar insulative substrate of a rectangular configuration. Disposed on the substrate is an array of conductive areas which extend from a contact terminal area of said substrate to an end of the substrate. There is a leadless sensor module positioned at said contact terminal area, with the contacts of said leadless sensor contacting contact terminals of said contact terminal area. The leadless sensor is enclosed by an enclosure which is coupled to the substrate and surrounds the sensor. The enclosure has a screen positioned on the top surface to prevent particles from entering or damaging the leadless sensor. The above-noted structure forms a very flat, compact pressure transducer which can be utilized in lieu of flex circuit type devices and provides greater mechanical stability as well as a more accurate output. | 06-02-2011 |
20110146411 | CMOS COMPATIBLE PRESSURE SENSOR FOR LOW PRESSURES - Pressure sensors having a topside boss and a cavity formed using deep reactive-ion etching (DRIE) or plasma etching. Since the boss is formed on the topside, the boss is aligned to other features on the topside of the pressure sensor, such as a Wheatstone bridge or other circuit elements. Also, since the boss is formed as part of the diaphragm, the boss has a reduced mass and is less susceptible to the effects of gravity and acceleration. These pressure sensors may also have a cavity formed using a DRIE or plasma etch. Use of these etches result in a cavity having edges that are substantially orthogonal to the diaphragm, such that pressure sensor die area is reduced. The use of these etches also permits the use of p-doped wafers, which are compatible with conventional CMOS technologies. | 06-23-2011 |
20110203381 | CORROSION-RESISTANT HIGH TEMPERATURE PRESSURE TRANSDUCER EMPLOYING A METAL DIAPHRAGM - A pressure transducer comprising a corrosion resistant metal diaphragm, having an active region, and capable of deflecting when a force is applied to the diaphragm; and a piezoresistive silicon-on-insulator sensor array disposed on a single substrate, the substrate secured to the diaphragm, the sensor array having a first outer sensor near an edge of the diaphragm at a first location and on the active region, a second outer sensor near an edge of the diaphragm at a second location and on the active region, and at least one center sensor substantially overlying a center of the diaphragm, the sensors connected in a bridge array to provide an output voltage proportional to the force applied to the diaphragm. The sensors are dielectrically isolated from the substrate. | 08-25-2011 |
20110209555 | Micromechanical pressure-sensor element and method for its production - A very robust sensor element for an absolute-pressure measurement is described, which is suitable for high temperatures and able to be miniaturized to a large extent. The micromechanical pressure-sensor element includes a sensor diaphragm having a rear-side pressure connection and at least one dielectrically insulated piezo resistor for signal acquisition. Furthermore, the pressure-sensor element has a front-side reference volume, which is sealed by a cap structure spanning the sensor diaphragm. The cap structure is realized as thin-film structure. | 09-01-2011 |
20110214505 | SEMICONDUCTOR PRESSURE SENSOR - There is provided a semiconductor pressure sensor which improves the sensor sensitivity and is excellent in the withstand pressure characteristic and the temperature characteristic. In the semiconductor pressure sensor in which a diaphragm is formed by a cavity provided on one of top and bottom surfaces of a silicon substrate and a plurality of piezoresistors is disposed in the diaphragm edge, a recess which has a larger area than the planar shape of the diaphragm and whose entire edge is located outward from the diaphragm edge in plan view is provided in a protective film which covers the entire surface of the silicon substrate on the diaphragm side. The protective film located on the diaphragm is preferably formed of SiO | 09-08-2011 |
20110259109 | SENSOR SYSTEM, METHOD FOR OPERATING A SENSOR SYSTEM, AND METHOD FOR MANUFACTURING A SENSOR SYSTEM - A sensor system, e.g., a pressure sensor system, includes a substrate having at least one trench on a first side. The trench is provided for forming a first diaphragm region on a second side opposite from the first side. In addition, a second diaphragm region and a cavern are integrated into the material of the first diaphragm region. | 10-27-2011 |
20110283803 | INTERNALLY SWITCHED MULTIPLE RANGE TRANSDUCERS - There is disclosed an internally switched multiple range transducer. The transducer employs a plurality of individual pressure sensors or Wheatstone bridges fabricated from semiconductor materials and utilizing piezoresistors. Each sensor is designed to accommodate accurately a given pressure range, therefore, each sensor is selected to provide an output when an applied pressure is within its accommodated range. As soon as the pressure exceeds the range, then another sensor is employed to produce an output. Each of the sensors, or each separate transducer, is coupled to a switch or other device to enable the selection of one of the plurality of sensors to operate within its given pressure range when the applied pressure is in that range. In this manner one obtains pressure measurements with a high degree of accuracy across a relatively large pressure range. | 11-24-2011 |
20110290032 | AUTOMOBILE GENERAL PRESSURE SENSOR - A general pressure sensor for an automobile comprising a sensor shell, a silicon piezoresistive sensitive core, a sensor core seat, a signal conditioning circuit, and an automobile electric device interface is disclosed. The silicon piezoresistive sensitive core, the sensor core seat and the signal conditioning circuit are disposed in the inner cavity of the sensor housing. The sensor housing is installed to the automobile electric device interface, and the silicon piezoresistive sensitive core comprises a silicon piezoresistive sensitive element and a glass ring sheet. The silicon piezoresistive sensitive element is welded and fixed to a surface of the glass ring sheet. An insulation oxidation layer is formed on one surface of the glass ring sheet and the silicon piezoresistive sensitive element. The other surface of the glass ring sheet is hermetically fixed to the ring-shape recession surface provided on the sensor core seat. The sensor core seat is hermetically and rotationally fixed to a pressure inlet on the sensor housing, after the inner lead wire on the silicon piezoresistive sensitive core is led to an interposing board provided on one end of the central hole through the other end of the central hole on the ring-shape recession surface of the sensor core seat, and then is led out by the automobile electric device interface via the signal conditioning circuit. | 12-01-2011 |
20110308324 | A SENSOR AND METHOD FOR FABRICATING THE SAME - A sensor and method for fabricating a sensor is disclosed that in one embodiment bonds an etched semiconductor substrate wafer to an etched device wafer comprising a silicon on insulator wafer to create a suspended structure, the flexure of which is determined by an embedded sensing element to measure absolute pressure. Interconnect channels embedded in the sensor facilitate streamlined packaging of the device while accommodating interconnectivity with other devices. | 12-22-2011 |
20110314923 | PRESSURE SENSOR WITH FIXED DEFORMABLE AREA - A pressure guiding bump is configured on the center of a pressure gauge to obtain a single “conductivity-pressure” curve feature which is independent from any position wherever a pressure is applied on the guiding bump. When a pressure is applied, the guiding bump guides the pressure against a fixed deformable area to be deformed, whatever the pressure is, the deformed area is nearly a same area. The pressure gauge is extraordinarily adequate to be designed in a weighing machine with parallel connection in between them. | 12-29-2011 |
20120060619 | TUNABLE PRESSURE TRANSDUCER ASSEMBLY - A tunable pressure transducer assembly that comprises a sensing element disposed within a housing, wherein the sensing element is adapted to output a signal substantially indicative of an applied pressure, and a filter assembly also disposed within the housing. The filter assembly comprises a cap and a tube, wherein the cap is spaced from the sensing element within the housing such that it encloses a set volume around the sensing element, and wherein the tube controls access of the applied pressure to the set volume. The filter assembly is operative to substantially reduce high frequency pressure ripples and allow static and quasi-static pressures to pass through to the sensing element, and may be manipulated to tune the pressure transducer assembly to achieve a desired dampening frequency. The filter assembly therefore enables one pressure transducer assembly outline to accurately measure pressure in various systems. | 03-15-2012 |
20120125115 | DEVICE FOR MEASURING PROPERTIES OF WORKING FLUIDS - There are provided embodiments of a sensing device that comprise a sensing element, a substrate, and a bonding element, each being selected for environments that utilize caustic working fluids such as automotive fuel. Material for use as the bonding element can form molecular bonds with ceramics and glass. In one embodiment, the sensing device comprises a receptacle or cavity, in which are located the sensing element and the bonding element. This configuration facilitates the formation of bonds between the bonding element and each of the sensing element and a peripheral wall of the cavity. Such bonds are configured in a tensile bonding area and a shear bonding area, the combination of which is useful to secure the sensing element in the cavity. The sensing device can further comprise a seal such as an o-ring disposed in annular relation to the substrate to seal the sensing device to a peripheral device such as a fluid fitting, which may be found in a fuel system of an automobile. | 05-24-2012 |
20120144921 | INCREASED SENSOR DIE ADHESION - Methods and devices for adhesively bonding a sensor die to a substrate are described. In some cases, a sensor assembly may include a pressure sensor die mounted to a substrate with an adhesive. The pressure sensor die may be fabricated to include a back-side having one or more adhesion features (e.g. recesses or indentations), which increase the surface area of the pressure sensor die that is in contact with the adhesive, to thereby increase the adhesion force therebetween. In some cases, the one or more adhesion features may define a non-planar interface between the pressure sensor die and the adhesive which, in some instances, may reduce the formation and/or propagation of cracks in the adhesive, which also may help increase the adhesion force therebetween. | 06-14-2012 |
20120174682 | MEDIA ISOLATED PRESSURE SENSOR - A media isolated pressure sensor is disclosed that helps improve performance and reduce cost. In one illustrative embodiment, a pressure sensor may include a carrier having one or more holes defined therein. The carrier may be coupled to a diaphragm on one side, and a pressure sensing die on the other, with the pressure sensing die in fluid communication with the hole in the carrier. The carrier, diaphragm and pressure sense die may form a transfer fluid cavity, which is filled with a pressure transfer fluid. An input pressure from a media to be sensed may be provided to the diaphragm, which transmits the pressure to the pressure sensing die via the pressure transfer fluid. The pressure sensing die remains isolated from the media to be sensed. | 07-12-2012 |
20120204653 | COMPENSATION OF STRESS EFFECTS ON PRESSURE SENSOR COMPONENTS - Pressure sensors having components with reduced variations due to stresses caused by various layers and components that are included in the manufacturing process. In one example, a first stress in a first direction causes a variation in a component. A second stress in a second direction is applied, thereby reducing the variation in the component. The first and second stresses may be caused by a polysilicon layer, while the component may be a resistor in a Wheatstone bridge. | 08-16-2012 |
20120240685 | Stepper Motor Gauge - A gauge includes a housing and a fitting having an inlet, an internal flow path, and an outlet. A sensor is in fluidic communication with the internal flow path and measures a characteristic of a fluid in the flow path. A control unit is in electrical communication with the pressure sensor, receives an output from the pressure sensor and generates a command based on the output received. A stepper motor has a rotor shaft with an indicator needle operatively connected thereto, and is in electrical communication with the control unit. A power supply is in electrical communication with the pressure sensor, the motor and the control unit for supplying power thereto. The control unit transmits the command to the stepper motor, which receives the command from the control unit and drives the rotor shaft according to the command, displaying the sensed characteristic via the needle. | 09-27-2012 |
20120247219 | PRESSURE TRANSDUCER UTILIZING NON-LEAD CONTAINING FRIT - A piezoresistive sensor device and method for making the same are disclosed. The device comprises a silicon wafer having piezoresistive elements and contacts in electrical communication with the elements. The device further comprises a contact glass coupled to the silicon wafer and having apertures aligned with the contacts. The device also comprises a non-conductive frit for mounting the contact glass to a header glass, and a conductive non-lead glass frit disposed in the apertures and in electrical communication with the contacts. The method for making the device comprises bonding a contact glass to a silicon wafer such that apertures in the glass line up with contacts on the wafer, and filling the apertures with a non-lead glass frit such that the frit is in electrical communication with the contacts. The use of a lead free glass frit prevents catastrophic failure of the device in ultra high temperature applications. | 10-04-2012 |
20120291560 | CORROSION-RESISTANT HIGH TEMPERATURE PRESSURE TRANSDUCER EMPLOYING A METAL DIAPHRAGM - A pressure transducer comprising a corrosion resistant metal diaphragm, having an active region, and capable of deflecting when a force is applied to the diaphragm; and a piezoresistive silicon-on-insulator sensor array disposed on a single substrate, the substrate secured to the diaphragm, the sensor array having a first outer sensor near an edge of the diaphragm at a first location and on the active region, a second outer sensor near an edge of the diaphragm at a second location and on the active region, and at least one center sensor substantially overlying a center of the diaphragm, the sensors connected in a bridge array to provide an output voltage proportional to the force applied to the diaphragm. The sensors are dielectrically isolated from the substrate. | 11-22-2012 |
20130042694 | FLAT COVERED LEADLESS PRESSURE SENSOR ASSEMBLIES SUITABLE FOR OPERATION IN EXTREME ENVIRONMENTS - An enclosed, flat covered leadless pressure sensor assembly suitable for extreme environment operation including dynamic, ultra-high temperature heating, light and heat flash, and high-speed, flow-related environments. The pressure sensor assembly comprises a substrate comprising a micromachined sensing diaphragm defined on a first side. A cover is attached to the first side of the substrate such that it covers at least the sensing diaphragm. The top surface of the cover is substantially flat, thereby promoting uniformity in the distribution of stress and thermal effects across a top surface of the cover. | 02-21-2013 |
20130167650 | PRESSURE SENSOR HAVING A PIEZORESISTIVE SENSOR CHIP ELEMENT - A piezoresistive sensor chip element of a pressure sensor has lower face with an outer edge, an adhesion area and a non-adhesion area. The chip has a closed chip cavity for measuring the pressure of a medium flowing around the chip. The upper face of a substrate is fastened only at the adhesion area of the chip. The non-adhesion area extends at least over a circular area arranged centrally on the lower face and covers a third of the lower face's total area and extends over at least one connection area from the circular area to the edge of the lower face. The pressure in the pressure medium can spread through the connection area into a space under the non-adhesion area on the element lower face. The substrate has a recess located centrally under the sensor chip element. | 07-04-2013 |
20130312532 | CORROSION-RESISTANT HIGH TEMPERATURE PRESSURE TRANSDUCER EMPLOYING A METAL DIAPHRAGM - A pressure transducer comprising a corrosion resistant metal diaphragm, having an active region, and capable of deflecting when a force is applied to the diaphragm; and a piezoresistive silicon-on-insulator sensor array disposed on a single substrate, the substrate secured to the diaphragm, the sensor array having a first outer sensor near an edge of the diaphragm at a first location and on the active region, a second outer sensor near an edge of the diaphragm at a second location and on the active region, and at least one center sensor substantially overlying a center of the diaphragm, the sensors connected in a bridge array to provide an output voltage proportional to the force applied to the diaphragm. The sensors are dielectrically isolated from the substrate. | 11-28-2013 |
20140090477 | INTERNALLY SWITCHED MULTIPLE RANGE TRANSDUCERS - Systems and methods for an internally switched multiple range transducer are provided. In one embodiment, a method comprises receiving, at a first sensor, a pressure, wherein the first sensor is associated with a first pressure range; measuring, at the first sensor, the pressure to generate a first pressure signal; in response to determining that the first pressure signal is not associated with the first pressure range, activating a second sensor, wherein the second sensor is associated with a second pressure range that is different from the first pressure range; and measuring, at the second sensor, the pressure to generate a second pressure signal. | 04-03-2014 |
20140123765 | Flat Covered Leadless Pressure Sensor Assemblies Suitable for Operation in Extreme Environments - This disclosure provides example methods, devices and systems associated with flat covered leadless pressure sensor assemblies suitable for operation in extreme environments. In one embodiment, a system may comprise a semiconductor substrate having a first side and a second side; a diaphragm disposed on the first side of the semiconductor substrate; a first cover coupled to the first side of the semiconductor substrate such that it overlays at least the diaphragm, wherein a pressure applied at the first cover is transferred to the diaphragm; and a sensing element disposed on the second side of the semiconductor substrate, wherein the sensing element is used to measure the pressure. | 05-08-2014 |
20140137654 | MEASURING DEVICE FOR MEASURING A PHYSICAL QUANTITY - Disclosed is a measuring device for measuring a physical quantity. The physical quantity could be a pressure and/or a force. The measuring device comprises a circular sensing structure comprising a membrane section which is deflected by force variations acting on the circular sensing structure. A first and second strain gauge are attached to the membrane section. The first strain gauge is configured to measure radial strain in a first surface area of the membrane section. The second strain gauge is configured to measure tangential strain in a second surface area of the membrane section. An increase in force acting on the sensing structure results in shrinking of the first surface area measured by the first strain gauge and stretching of the second surface area measured by the second strain gauge. | 05-22-2014 |
20140165735 | MATCHING BACK PRESSURES ON DIFFERENTIAL OIL-FILLED DIAPHRAGMS - Exemplary embodiments of the present invention provide a differential pressure transducer that comprises first and second diaphragms of different configurations, i.e., different diameters and/or thicknesses. The pressure transducer provides more versatility over prior art designs as the diaphragms can be of different configurations yet still maintain substantially similar back pressures. Therefore, the errors commonly associated with back pressures are eliminated because the back pressures from the diaphragms ultimately cancel out in the sensor's differential pressure measurement. | 06-19-2014 |
20140216163 | PRESSURE SENSOR AND METHOD FOR PRODUCING A PRESSURE SENSOR - A pressure sensor ( | 08-07-2014 |
20150059486 | RESISTIVE PRESSURE SENSOR INCLUDING PIEZO-RESISTIVE ELECTRODE - Provided is a pressure sensor including an elastic thin film including a first surface and a second surface that face each other, the elastic thin film including an elastomer material, a plurality of protruding deformable structures patterned on the first surface; a piezoresistive electrode formed along surfaces of the plurality of protruding deformable structures; and a counter electrode disposed to face the piezoresistive electrode. | 03-05-2015 |
20150068315 | MEDIA ISOLATED PRESSURE SENSOR - A pressure sensor includes a pressure sensing element and a top cap. The pressure sensing element includes a bonded wafer substrate having a buried sealed cavity. A wall of the buried sealed cavity forms a sensing diaphragm. One or more sense elements may be supported by the sensing diaphragm and one or more bond pads are supported by the upper side of the bonded wafer substrate. Each of the bond pads may be positioned adjacent to the sensing diaphragm and electrically connected to one or more of the sense elements. The top cap may be secured to the upper side of the bonded wafer substrate such that an aperture in the top cap facilitates passage of a media in a downward direction to the sensing diaphragm. The top cap may be configured to isolate the bond pads from the media. | 03-12-2015 |
20150330855 | LOWER LIMB FORCE SENSING SYSTEM - Lower limb force sensing system includes a sensory insole formed of a plurality of thin film material layers arranged in a stack to form a plurality of sensor cells in a pattern that defines a sensor array. A plurality of perforations defined in the thin film material layers extend substantially around a perimeter of each sensor cell to substantially separate each sensor cell from a remainder of the thin film material layers and form a hinge member which extends from each sensor cell to an interstitial portion of the thin film layers extending between adjacent ones of the sensor cells. The hinge member defines an axis of rotation about which the sensor cell can pivot independently relative to adjacent interstitial portions of the thin film material layers. | 11-19-2015 |
20150330856 | PRESSURE SENSOR DEVICE WITH HIGH SENSITIVITY AND HIGH ACCURACY - The voltages output from a low-pressure MEMS sensor are increased by increasing the sensitivity of the sensor. Sensitivity is increased by thinning the diaphragm of the low pressure sensor device with corner trench. Nonlinearity increased by thinning the diaphragm is reduced by simultaneously creating a cross stiffener to the bottom side of the diaphragm. A rim, anchors, and a stiffener pad can also be added to further stiffen the thinner diaphragm and further reduce pressure nonlinearity. | 11-19-2015 |
20150369681 | PHYSICAL QUANTITY SENSOR, ELECTRONIC DEVICE, ALTIMETER, ELECTRONIC APPARATUS, AND MOBILE OBJECT - A physical quantity sensor includes: a physical quantity sensor chip which detects a physical quantity and generates an electrical signal; a package which has an internal space and accommodates the physical quantity sensor chip in the internal space; and a first wire which connects the package and the physical quantity sensor chip together. The physical quantity sensor chip is moored in the internal space by the first wire. | 12-24-2015 |
20160047704 | PHYSICAL QUANTITY SENSOR, PRESSURE SENSOR, ALTIMETER, ELECTRONIC APPARATUS, AND MOVING OBJECT - A physical quantity sensor includes a substrate that has a recess that is open toward one side of the substrate, a diaphragm that has a bottom of the recess as part of the diaphragm and undergoes bending deformation under pressure, a piezoresistance device that is disposed in the diaphragm, a coating layer that faces the diaphragm via a cavity, and wiring layers that are disposed between the substrate and the coating layer, and form, along with the substrate and the coating layer, the cavity. Each of the wiring layers contains a metal, and in a plan view, a circumferential edge of the bottom of the recess is closer to the center of the diaphragm than a substrate-side end of an inner wall surface of one of the wiring layers. | 02-18-2016 |
20160138990 | Electronic Device, Physical Quantity Sensor, Pressure Sensor, Altimeter, Electronic Apparatus, And Moving Object - A physical quantity sensor includes a substrate, a piezoresistive element disposed on one surface side of the substrate, a wall portion disposed to surround the piezoresistive element, in a plan view of the substrate, on the one surface side of the substrate, and a covering layer disposed on the side opposite to the substrate with respect to the wall portion and constituting a cavity together with the wall portion. The covering layer includes a corner portion configured to include two sides adjacent to each other in the plan view, and a reinforcing portion disposed to couple the two sides. | 05-19-2016 |
20160146685 | PIEZORESISTIVE PRESSURE SENSOR DEVICE - The voltages output from a low-pressure MEMS sensor are increased by increasing the sensitivity of the sensor. Sensitivity is increased by thinning the diaphragm of the low pressure sensor device. Nonlinearity increased by thinning the diaphragm is reduced by simultaneously creating a cross stiffener on the top side of the diaphragm. An over-etch of the top side further increases sensitivity. | 05-26-2016 |
20160153857 | ELECTRONIC DEVICE, PHYSICAL QUANTITY SENSOR, PRESSURE SENSOR, VIBRATOR, ALTIMETER, ELECTRONIC APPARATUS, AND MOVING OBJECT | 06-02-2016 |
20160153858 | CASE ISOLATED OIL FILLED MEMS PRESSURE SENSOR | 06-02-2016 |
20160377496 | PRESSURE SENSOR DEVICE WITH A MEMS PIEZORESISTIVE ELEMENT ATTACHED TO AN IN-CIRCUIT CERAMIC BOARD - A pressure sensor device with a MEMS piezoresistive pressure sensing element attached to an in-circuit ceramic board comprises a monolithic ceramic circuit board formed by firing multiple layers of ceramic together. The bottom side of the circuit board has a cavity, which extends through layers of material from the ceramic circuit board is formed. A ceramic diaphragm, which is one of the layers, has a peripheral edge. The diaphragm's thickness enables the diaphragm bounded by the edge to deflect responsive to applied pressure. A MEMS piezoresistive pressure sensing element attached to the top side of the ceramic circuit board generates an output signal responsive to deflection of the ceramic diaphragm. A conduit carrying a pressurized fluid (liquid or gas) can be attached directly to the ceramic circuit board using a seal on the bottom of the ceramic circuit board, which surrounds the opening of the cavity through the bottom. | 12-29-2016 |