scholarly journals Study on the Stability of the Electrical Connection of High-Temperature Pressure Sensor Based on the Piezoresistive Effect of P-Type SiC

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 216
Author(s):  
Yongwei Li ◽  
Ting Liang ◽  
Cheng Lei ◽  
Qiang Li ◽  
Zhiqiang Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
Extreme Environment ◽  
Maximum Temperature ◽  
Piezoresistive Effect ◽  
Electrical Connection ◽  
Contact Stability ◽  
The Stability ◽  
P Type

In this study, a preparation method for the high-temperature pressure sensor based on the piezoresistive effect of p-type SiC is presented. The varistor with a positive trapezoidal shape was designed and etched innovatively to improve the contact stability between the metal and SiC varistor. Additionally, the excellent ohmic contact was formed by annealing at 950 °C between Ni/Al/Ni/Au and p-type SiC with a doping concentration of 1018cm−3. The aging sensor was tested for varistors in the air of 25 °C–600 °C. The resistance value of the varistors initially decreased and then increased with the increase of temperature and reached the minimum at ~450 °C. It could be calculated that the varistors at ~100 °C exhibited the maximum temperature coefficient of resistance (TCR) of ~−0.35%/°C. The above results indicated that the sensor had a stable electrical connection in the air environment of ≤600 °C. Finally, the encapsulated sensor was subjected to pressure/depressure tests at room temperature. The test results revealed that the sensor output sensitivity was approximately 1.09 mV/V/bar, which is better than other SiC pressure sensors. This study has a great significance for the test of mechanical parameters under the extreme environment of 600 °C.

scholarly journals A Ceramic Diffusion Bonding Method for Passive LC High-Temperature Pressure Sensor

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2676
Author(s):  
Chen Li ◽  
Boshan Sun ◽  
Yanan Xue ◽  
Jijun Xiong
Keyword(s):  
High Temperature ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
Alumina Ceramic ◽  
Harsh Environments ◽  
Ceramic Substrates ◽  
Integrated Technology ◽  
All Ceramic ◽  
Test Platform ◽  
Bonding Method

Alumina ceramic is a highly promising material for fabricating high-temperature pressure sensors. In this paper, a direct bonding method for fabricating a sensitive cavity with alumina ceramic is presented. Alumina ceramic substrates were bonded together to form a sensitive cavity for high-temperature pressure environments. The device can sense pressure parameters at high temperatures. To verify the sensitivity performance of the fabrication method in high-temperature environments, an inductor and capacitor were integrated on the ceramic substrate with the fabricated sensitive cavity to form a wireless passive LC pressure sensor with thick-film integrated technology. Finally, the fabricated sensor was tested using a system test platform. The experimental results show that the sensor can realize pressure measurements above 900 °C, confirming that the fabricated sensitive cavity has excellent sealing properties. Therefore, the direct bonding method can potentially be used for developing all-ceramic high-temperature pressure sensors for application in harsh environments.

scholarly journals Hierarchical network enabled flexible textile pressure sensors with ultra-high sensitivity, ultra-wide linearity and high-temperature resistance

2021 ◽  
Author(s):  
Meiling Jia ◽  
Chenghan Yi ◽  
Yankun Han ◽  
Xin Li ◽  
Guoliang Xu ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Pressure Sensor ◽  
High Performance ◽  
Full Range ◽  
Pressure Sensors ◽  
Fiber Surface ◽  
High Sensitivity ◽  
Harsh Environments ◽  
Point To Point

Abstract Thin, lightweight, and flexible textile pressure sensors with the ability to precisely detect the full range of faint pressure (< 100 Pa), low pressure (in the range of KPa) and high pressure (in the range of MPa) are in significant demand to meet the requirements for applications in daily activities and more meaningfully in some harsh environments, such as high temperature and high pressure. However, it is still a major challenge to fulfill these requirements simultaneously in a single pressure sensor. Herein, a high-performance pressure sensor enabled by polyimide fiber fabric with functionalized carbon-nanotube (PI/FCNT) is obtained via a facile electrophoretic deposition (EPD) approach. High-density FCNT is evenly wrapped and chemically bonded to the fiber surface during the EPD process, forming a conductive hierarchical fiber/FCNT matrix. Benefiting from the abundant yet firm contacting points, point-to-point contacting mode, and high elastic modulus of both PI and CNT, the proposed PI/FCNT pressure sensor exhibits ultra-high sensitivity (3.57 MPa− 1), ultra-wide linearity (3.24 MPa), exceptionally broad sensing range (~ 45 MPa), and long-term stability (> 4000 cycles). Furthermore, under a high working temperature of 200 ºC, the proposed sensor device still shows an ultra-high sensitivity of 2.64 MPa− 1 within a wide linear range of 7.2 MPa, attributing to its intrinsic high-temperature-resistant properties of PI and CNT. Thanks to these merits, the proposed PI/FCNT(EPD) pressure sensor could serve as an E-skin device to monitor the human physiological information, precisely detect tiny and extremely high pressure, and can be integrated into an intelligent mechanical hand to detect the contact force under high-temperature (> 300 ºC), endowing it with high applicability in the fields of real-time health monitoring, intelligent robots, and harsh environments.

scholarly journals Sixty Earth-Day Test of a Prototype Pt/HTCC Alumina Package in a Simulated Venus Environment

2019 ◽  
Vol 16 (2) ◽  
pp. 78-83 ◽  
Author(s):  
Liangyu Chen ◽  
Philip G. Neudeck ◽  
Roger D. Meredith ◽  
Dorothy Lukco ◽  
David J. Spry ◽  
...  
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Extreme Environment ◽  
Electrical Performance ◽  
Harsh Environment ◽  
Three Phase ◽  
Testing Environments ◽  
Earth Day ◽  
The Stability ◽  
Surface Environment

Abstract This article presents experimental results of a prototype high-temperature cofired ceramic (HTCC) package with Au/Pt metallization in a three-phase harsh environment test that culminated with a 60-d demonstration in a simulated Venus surface environment consisting of a 465°C corrosive atmosphere at 90 bar pressure. The prototype package is based on a previously developed and reported HTCC package successfully tested with multiple analog and digital silicon carbide high-temperature semiconductor integrated circuits in 500°C Earth air ambient for more than 10,000 hours, and short-term tested at temperatures above 800°C. The three-phase harsh environment test started with 48 h in 465°C Earth air, followed by 48 h in 465°C nitrogen at 90 bar pressure and 1,400 h in a simulated Venus surface environment of 465°C corrosive atmosphere at 90 bar. In addition to in situ electrical tests in a three-phase harsh environment and posttest electrical diagnosis, initial posttest analysis of the package materials and surfaces was performed to assess the stability of the packaging materials in the testing environments, as well as the surface conditions after the test. The test in the simulated Venus environment was implemented in the NASA Glenn Extreme Environment Rig. The results of this study suggest that an effective encapsulation of areas of surface metallization and vicinities may help improve the long-term electrical performance of an HTCC alumina packaging system in a Venus environment.

Design and Fabrication of Leadless Package Structure for Pressure Sensors

2021 ◽  
Author(s):  
Junwang Tian ◽  
Zhong Jin ◽  
Xin Tang ◽  
Wenxian Peng ◽  
Junfu Liu ◽  
...  
Keyword(s):  
Thermal Stress ◽  
High Temperature ◽  
Pressure Sensor ◽  
Silicone Oil ◽  
Pressure Sensors ◽  
Gold Wire ◽  
Electrical Signal ◽  
Back Side ◽  
Element Analysis ◽  
Silver Paste

Abstract Silicon piezoresistive pressure sensors can only operate below 125°C due to the leakage current of the PN junction. However, SOI high temperature pressure sensors use SiO2 for full dielectric isolation to solve this problem. At present, SOI high temperature pressure sensors mostly use lead bonding package structure, with gold wire to lead the electrical signal and silicone oil as the protection medium, but the working temperature of silicone oil is limited to about 150?. In this paper, the leadless package structure is designed by using pressure conduction on the back side of the chip and replacing the gold wire with conductive silver paste, and the materials and dimensions of the leadless package structure are determined. The reliability of the leadless package structure was verified by finite element analysis, and the results showed that the thermal stress caused by high and low temperature cycles in the leadless package is very small and does not affect the sensitivity of the pressure-sensitive chip. The size of the leadless package structure was optimized by Taguchi orthogonal method, and the maximum thermal stress was effectively reduced. Also, the key factors affecting the thermal stress of the leadless package in the package structure were identified by the variance number analysis method. The electrical signal conduction of the pressure sensor is achieved by a silver paste sintering process, and the data show that the sensitivity of the pressure sensor is 30.82 mV/MPa with a nonlinearity of less than 0.4% FS.

scholarly journals Hermeticity Analysis on SiC Cavity Structure for All-SiC Piezoresistive Pressure Sensor

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 379
Author(s):  
Baohua Tian ◽  
Haiping Shang ◽  
Lihuan Zhao ◽  
Dahai Wang ◽  
Yang Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
Absolute Pressure ◽  
Microstructure Observation ◽  
Thermal Expansion Coefficients ◽  
Piezoresistive Pressure Sensor ◽  
Cavity Structure ◽  
Sic Wafer ◽  
Temperature Applications

The hermeticity performance of the cavity structure has an impact on the long-term stability of absolute pressure sensors for high temperature applications. In this paper, a bare silicon carbide (SiC) wafer was bonded to a patterned SiC substrate with shallow grooves based on a room temperature direct bonding process to achieve a sealed cavity structure. Then the hermeticity analysis on the SiC cavity structure was performed. The microstructure observation demonstrates that the SiC wafers are tightly bonded and the cavities remain intact. Moreover, the tensile testing indicates that the tensile strength of bonding interface is ~8.01 MPa. Moreover, the quantitative analysis on the airtightness of cavity structure through leakage detection shows a helium leak rate of ~1.3 × 10−10 Pa⋅m3/s, which satisfies the requirement of the specification in the MIL-STD-883H. The cavity structure can also avoid an undesirable deep etching process and the problem caused by the mismatch of thermal expansion coefficients, which can be potentially further developed into an all-SiC piezoresistive pressure sensor employable for high temperature applications.

A Full Printed Flexible Pressure Sensor with Improved Temperature Performance based on Optimized Curing Mechanism

2021 ◽  
Author(s):  
Jingnan Ma ◽  
Mengmeng Liang ◽  
Wei Wang
Keyword(s):  
High Temperature ◽  
Pressure Sensor ◽  
Flexible Electronics ◽  
Material Selection ◽  
Pressure Sensors ◽  
Functional Materials ◽  
Temperature Performance ◽  
Curing Mechanism ◽  
Flexible Pressure Sensor ◽  
Flexible Pressure Sensors

Printable flexible pressure sensors have many important applications in wearable systems. One major challenge of such a sensor is to maintain sensing properties in high temperature. By optimizing the curing mechanism of the flexible pressure sensor functional materials, this paper proposes a new method of achieving high temperature properties for a full printed sensor. The establishment of curing theory is mainly studied. The printing process of this kind of sensor is systematically stated and tested to check whether it can continue to function at high temperatures. Ultimately a fully-printed flexible pressure sensor with good temperature performance is achieved. The paper focuses around the technical route of “material selection—theoretical analysis —function material preparation—design and preparation of device—device performance evaluation”. Suitable materials are used in flexible pressure sensors and the curing mechanism is established. This proposed technique can be extended to the development of other printable flexible sensors, which can lead to a huge impact on future applications of the flexible electronics.

Design of 6H-SiC High Temperature Pressure Sensor Chip

2013 ◽  
Vol 562-565 ◽  
pp. 166-171
Author(s):  
Xi Min Ma ◽  
Fei Tang ◽  
Xiao Hao Wang
Keyword(s):  
High Temperature ◽  
Pressure Sensor ◽  
Radial Direction ◽  
Simple Structure ◽  
Pressure Sensors ◽  
Deep Etching ◽  
Scheme Design ◽  
Strain Coefficient ◽  
Circular Diaphragm ◽  
Pressure Resistance

Over the last decade, a relatively in-depth research on the different structures and types of the full SiC pressure sensors including the piezoresistive, the capacitive and the optical SiC pressure sensors etc. has been conducted with a view to realizing the pressure measurement in high temperature circumstances. The piezoresistive SiC pressure sensor has gradually become the focus of research due to its simple structure and convenience application. In our research, the piezoresistance strip is designed on the deep-etching sensitive circular diaphragm formed via deep etching. Firstly, the 6H-SiC strain coefficient GF value is compared on the radial direction and the transverse direction by analyzing the circular diaphragm deformation theory. It’s concluded that both in the radial direction, four resistance strips are assigned in the center of circular diaphragm and along the edge respectively, with equal number on these two locations. Better consistency and sensitivity are achieved by this solution. Secondly, the design size of the sensitive circular diaphragm and the pressure resistance strips are determined with the expected work temperature and the target measuring range being taken into consideration. The final layout scheme design of four pressure resistance strips is determined through simulation on the consideration of the thermal stress caused by the AlN packaging.

scholarly journals A Micromachined Piezoresistive Pressure Sensor with a Shield Layer

2016 ◽  
Author(s):  
Gang Cao ◽  
Xiaoping Wang ◽  
Yong Xu ◽  
Sheng Liu
Keyword(s):  
Pressure Sensor ◽  
Pressure Sensors ◽  
Temperature Drift ◽  
Electrical Field ◽  
Piezoresistive Pressure Sensor ◽  
Improved Stability ◽  
Developed Pressure ◽  
Piezoresistive Pressure Sensors ◽  
P Type ◽  
The Impact

This paper presents a piezoresistive pressure sensor with a shield layer for improved stability. Compared with the conventional piezoresistive pressure sensors, p-type piezoresistors are covered by an n-type shield layer, which is formed by ion implantation. The proposed pressure sensors have been successfully fabricated by bulk micromachining techniques. The impact of electrical field on piezoresistors is studied by simulation. The temperature drift of the pressure sensor has been investigated by both simulation and experimental measurement. Characteristics of developed pressure sensors are tested from -40 C to 125 C. A sensitivity of 0.022 mV/V/KPa and a maximum non-linearity of 0.085% FS are measured for the fabricated sensor in a pressure range of 1 MPa. The temperature coefficients of resistance of shielded piezoresistors are found to be smaller than those of un-shielded ones. It is demonstrated that the shield layer is able to reduce the drift caused by electrical field and ambient temperature variation.

scholarly journals Development and Commissioning of High Temperature FBG Solid Pressure Sensors

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Hong-Ying Guo ◽  
Zhao-Ba Wang ◽  
Hai-yang Li
Keyword(s):  
High Temperature ◽  
Pressure Sensor ◽  
Temperature Compensation ◽  
Shape Change ◽  
Pressure Sensors ◽  
Compensation Method ◽  
Fiber Grating ◽  
Design Structure ◽  
Safety Research ◽  
Depth Analysis

In this work, a new type of high temperature fiber grating diaphragm pressure sensor is described, including the physical design structure, in-depth analysis of optical response to changes in pressure, and a discussion of the temperature compensation method. Mathematical model of high-temperature compressive shape change and normal-temperature compressive shape change is built, and effective temperature compensation method is proposed, which can both contribute to solve temperature interference of pressure sensor at high temperature. In addition, the simulation computation is conducted for the external encapsulation of the sensor under the high-temperature and pressure according to the design model. Through analysis and comparison of data affecting the changing position of grating signal, the correctness of the simulation result is verified by the development of the prototype. The temperature compensation method is proposed to realize pressure measurement of sensor with a relative error below 4.6%F.S. and range to 50 MPa in the environment of 300, which meets with the safety research requirement of the cartridge system.

scholarly journals Hierarchical network enabled flexible textile pressure sensor with ultra-broad response range and high-temperature resistance

2021 ◽  
Author(s):  
Meiling Jia ◽  
Chenghan Yi ◽  
Yankun Han ◽  
Xin Li ◽  
Guoliang Xu ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Pressure Sensor ◽  
Full Range ◽  
Pressure Sensors ◽  
Fiber Surface ◽  
Harsh Environments ◽  
Temperature Resistance ◽  
High Temperature Resistance ◽  
Fiber Fabric

Abstract Thin, lightweight, and flexible textile pressure sensors with the ability to detect the full range of faint pressure (<100 Pa), low pressure (in the range of KPa) and high pressure (in the range of MPa) are in significant demand to meet the requirements for applications in daily activities and more meaningfully in some harsh environments, such as high temperature and high pressure. However, it is still a significant challenge to fulfill these requirements simultaneously in a single pressure sensor. Herein, a high-performance pressure sensor enabled by polyimide fiber fabric with functionalized carbon-nanotube (PI/FCNT) is obtained via a facile electrophoretic deposition (EPD) approach. High-density FCNT is evenly wrapped and chemically bonded to the fiber surface during the EPD process, forming a conductive hierarchical fiber/FCNT matrix. Benefiting from the large compressible region of PI fiber fabric, abundant yet firm contacting points, point-to-point contacting mode, and high elastic modulus of both PI and CNT, the proposed PI/FCNT pressure sensor can be customized and modulated to achieve both a wide linear ranges, ultra-broad sensing range, long-term stability and high-temperature resistance. Thanks to these merits, the proposed PI/FCNT(EPD) pressure sensor could monitor the human physiological information, detect tiny and extremely high pressure, can be integrated into an intelligent mechanical hand to detect the contact force under high-temperature (>300 ºC), endowing it with high applicability in the fields of real-time health monitoring, intelligent robots, and harsh environments.

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