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 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 Modeling of a square-shape ZnO, ZnS and AlN membrane for mems capacitive pressure-sensor applications

2020 ◽  
Vol 11 ◽  
pp. 14
Author(s):  
Ahmad Dagamseh ◽  
Qais Al-Bataineh ◽  
Zaid Al-Bataineh ◽  
Nermeen S. Daoud ◽  
Ahmad Alsaad ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Pressure Sensor ◽  
Membrane Structure ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Membrane Thickness ◽  
Capacitive Pressure Sensor ◽  
The Finite Element Method ◽  
Sensor Applications ◽  
Opposite Behavior

In this paper, mathematical modeling and simulation of a MEMS-based clamped square-shape membrane for capacitive pressure sensors have been performed. Three types of membrane materials were investigated (i.e. Zinc Oxide (ZnO), Zinc Sulfide (ZnS) and Aluminum Nitride (AlN)). Various performance parameters such as capacitance changes, deflection, nonlinearity, the sensitivity of the membrane structure for different materials and film-thicknesses have been considered using the Finite Element Method (FEM) and analytically determined using the FORTRAN environment. The simulation model outperforms in terms of the effective capacitance value. The results show that the membrane deflection is linearly related to the applied pressure. The ZnS membrane provides a capacitance of 0.023 pico-Farad at 25 kPa with a 42.5% relative capacitance changes to reference capacitance. Additionally, the results show that for ZnO and AlN membranes the deflection with no thermal stress is higher than that with thermal stress. However, an opposite behavior for the ZnS membrane structure has been observed. The mechanical and capacitance sensitivities are affected by the membrane thickness as the capacitance changes are inversely proportional to the membrane thickness. Such results open possibilities to utilize various materials for pressure sensor applications by means of the capacitance-based detection technique.

Thin Film Polymer Stress Measurement Using Piezoresistive Anisotropically Etched Pressure Sensors

1996 ◽  
Vol 436 ◽  
Author(s):  
G. Bitko ◽  
R. Harries ◽  
J. Matldn ◽  
A. C. McNeil ◽  
D. J. Monk ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Stress ◽  
High Temperature ◽  
Material Properties ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Offset Voltage ◽  
High Temperature Storage ◽  
Linear Expression ◽  
Temperature Storage

AbstractSilicon bulk micromachined piezoresistive pressure sensors are very sensitive to applied stresses: that is, applied pressure and/or packaging-related stresses. Device encapsulation has been observed to affect the electrical output of the pressure sensor significantly. The magnitude of the zero applied pressure output voltage (i.e., the offset voltage) that can be attributed to a thin film encapsulant is proportional to the magnitude of the roomtemperature thermal stress of that film. Parylene C coatings have been used as encapsulants in this work. Finite element and analytical modeling techniques were used to evaluate the effect of material property variation on the offset of a pressure sensor. A simple, linear expression of offset as a function of a material property parametric group, that includes: parylene thickness, parylene biaxial modulus, parylene CTE, silicon thickness, and annealing temperature; has been established. Experimental analysis of parylene coated pressure sensors and parylene coated silicon and gallium arsenide wafers was performed to confirm the resulting model. Known variations in parylene material properties caused by processing (i.e., uncontrolled deposition, annealing, and high temperature storage) have been used as an experimental vehicle for this purpose. An empirical relationship between offset voltage on parylene coated devices and room-temperature thermal stress on parylene coated wafers that have been exposed to the same processing is a linear expression with a similar slope to the modeling results. Furthermore, stress measurements from parylene coated silicon wafers and parylene coated gallium arsenide wafers have been used to estimate the parylene biaxial modulus (approximately 5000 MPa) and the parylene CTE (approximately 50 ppm/°C) independently. These material properties were observed to shift following parylene annealing and high temperature storage exposure experiments in a manner that is consistent with the established model.

Thermal Stress and Failure Location Analysis for Through Silicon via in 3D Integration

2015 ◽  
Vol 32 (1) ◽  
pp. 47-53 ◽  
Author(s):  
H.-Y. Tsai ◽  
C.-W. Kuo
Keyword(s):  
Thermal Expansion ◽  
Thermal Stress ◽  
High Temperature ◽  
Stress Distribution ◽  
Surface Area ◽  
Dielectric Material ◽  
Three Dimensional ◽  
3D Integration ◽  
Element Analysis ◽  
Through Silicon Via

AbstractThrough silicon via (TSV) is the critical structure for three dimensional (3D) integration, which provides vertical interconnection between stacking dies. In TSV structure, large coefficient differences of thermal expansion exist between silicon substrate, dielectric material, and filled metal. Due to the large thermal mismatch, the high thermal stress occurring at the interface of different materials would result in delamination. Therefore, thermal-mechanical reliability is a key issue for 3D integration. In this study, we investigated the thermal-mechanical stress distribution of TSV under the condition of the accelerated thermal cycling loading by finite element analysis based on a 3D model of TSV structure. Due to the thermal expansion, that the TSV structure squeezed the surface area between TSVs at a high temperature resulted in compressive stresses at the surface area between TSVs. Therefore, a proper distance between the stress-sensitive device and the TSV should be kept. The stress analysis shows that the maximum thermal stress occurs in the outside region of TSV interface and in the annular region of TSV at a high temperature and at a low temperature, respectively. This study helps to obtain a clear thermal stress distribution of TSV and possible failure regions can be determined.

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.

Development of Biocompatible MEMS Wireless Capacitive Pressure Sensor

2005 ◽  
Vol 2 (4) ◽  
pp. 287-296
Author(s):  
Shankaran Janardhanan ◽  
Joan. Z. Delalic ◽  
Jeffrey Catchmark ◽  
Dharanipal Saini
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Resonant Frequency ◽  
Pressure Sensor ◽  
Impedance Matching ◽  
Pressure Sensors ◽  
Important Variable ◽  
Bladder Pressure ◽  
Capacitive Pressure Sensor ◽  
Element Analysis

The objective of this research was to develop a wireless pressure sensor useful for monitoring bladder pressure. The wireless sensor consists of an active capacitive element and an inductor coil. The changes in pressure are related to the changes in the resonant frequency of the internal sensor. The existing pressure sensors have inductors formed on both sides of the substrate. The changes in internal capacitance of these sensors are related to the changes in pressure by impedance matching of the internal LC circuit. The deviation in bladder pressure is an important variable in evaluating the diseased state of the bladder. The inductor designed for this application is a spirally wound inductor fabricated adjacent to the capacitor. The external sensing uses equivalent changes in internal LC. The resonant frequency of the internal sensor is defined by the deformation of the plate, causing the plate to touch the dielectric on the fixed capacitive plate, which is reflected as changes in capacitance(C). The deformation of the plate has been modeled using Finite Element Analysis. The finite element analysis optimizes the dimensions of the design. Remote sensing is achieved through inductive coupling and the changes in pressure are determined. The device is tested for pressures ranging from 0–150 mmHg, bladder pressure. The RF Telemetry system has been modeled using Sonnet. The frequency range is between 100–670 MHz which is in compliance to that specified by Federal Communications Commission (FCC) regulations.

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.

scholarly journals Ultra-Sensitive Flexible Pressure Sensor Based on Microstructured Electrode

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 371 ◽  
Author(s):  
Mengmeng Li ◽  
Jiaming Liang ◽  
Xudong Wang ◽  
Min Zhang
Keyword(s):  
Pressure Sensor ◽  
Dielectric Layer ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Capacitive Sensor ◽  
Duty Ratio ◽  
Capacitive Pressure Sensor ◽  
Element Analysis ◽  
Sequential Coupling ◽  
Flexible Pressure Sensors

Flexible pressure sensors with a high sensitivity in the lower zone of a subtle-pressure regime has shown great potential in the fields of electronic skin, human–computer interaction, wearable devices, intelligent prosthesis, and medical health. Adding microstructures on the dielectric layer on a capacitive pressure sensor has become a common and effective approach to enhance the performance of flexible pressure sensors. Here, we propose a method to further dramatically increase the sensitivity by adding elastic pyramidal microstructures on one side of the electrode and using a thin layer of a dielectric in a capacitive sensor. The sensitivity of the proposed device has been improved from 3.1 to 70.6 kPa−1 compared to capacitive sensors having pyramidal microstructures in the same dimension on the dielectric layer. Moreover, a detection limit of 1 Pa was achieved. The finite element analysis performed based on electromechanical sequential coupling simulation for hyperelastic materials indicates that the microstructures on electrode are critical to achieve high sensitivity. The influence of the duty ratio of the micro-pyramids on the sensitivity of the sensor is analyzed by both simulation and experiment. The durability and robustness of the device was also demonstrated by pressure testing for 2000 cycles.

Sign in / Sign up

Export Citation Format

Share Document