An Overmolded Pressure Sensor Package Using an Ultrathick Photoresist Sacrificial Layer

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Lung-Tai Chen ◽  
Wood-Hi Cheng
Keyword(s):  
Pressure Sensor ◽  
Output Voltage ◽  
Sacrificial Layer ◽  
Pressure Sensors ◽  
Element Model ◽  
Silicon Membrane ◽  
Molding Process ◽  
Molding Compound ◽  
Voltage Drift ◽  
Sensor Package

This study presents a novel technique for an overmolded package of piezoresistive pressure sensors using an ultrathick photoresist sacrificial layer. A 150 μm photoresist block is placed just on the silicon membrane of the pressure sensor and removed after the molding transfer process. The removal of the photoresist block exposes and reserves a sensing channel in the overmolded pressure sensor package. Experimental observations reveal that the silicon membrane of the pressure sensor is completely free of any epoxy molding compound contamination after the transfer molding process. The effectiveness of the photoresist block in shielding the silicon membrane of the pressure sensor was confirmed. Experiment and finite element model results reveal that the packaged pressure sensor has similar sensing characteristics to those of an unpackaged pressure sensor at room temperature. However, the packaged pressure sensor exerts a thermomechanical stress on the silicon membrane of the pressure sensor, resulting in an undesired output voltage drift. Employing a proper package design can reduce the output voltage drift. The proposed packaging scheme has a small package volume and surface mount device compatible features, making it suitable for portable commercial devices.

Design and Simulation of Pressure Sensor for Ocean Depth Measurements

2013 ◽  
Vol 313-314 ◽  
pp. 666-670 ◽  
Author(s):  
K.J. Suja ◽  
Bhanu Pratap Chaudhary ◽  
Rama Komaragiri
Keyword(s):  
Pressure Sensor ◽  
Integrated Circuit ◽  
Output Voltage ◽  
Pressure Sensors ◽  
Micro Electro Mechanical System ◽  
Constant Thickness ◽  
Piezoresistive Pressure Sensor ◽  
Wide Pressure Range ◽  
Processing Techniques ◽  
Wide Pressure

MEMS (Micro Electro Mechanical System) are usually defined as highly miniaturized devices combining both electrical and mechanical components that are fabricated using integrated circuit batch processing techniques. Pressure sensors are usually manufactured using square or circular diaphragms of constant thickness in the order of few microns. In this work, a comparison between circular diaphragm and square diaphragm indicates that square diaphragm has better perspectives. A new method for designing diaphragm of the Piezoresistive pressure sensor for linearity over a wide pressure range (approximately double) is designed, simulated and compared with existing single diaphragm design with respect to diaphragm deflection and sensor output voltage.

An Innovative Technology for Measuring The Dynamic Characteristics of Pressure Sensors

2006 ◽  
Vol 505-507 ◽  
pp. 1057-1062 ◽  
Author(s):  
Ho Chang ◽  
Mu Jung Kao ◽  
Tsing Tshih Tsung ◽  
J.L. Wu
Keyword(s):  
Dynamic Characteristics ◽  
Spectrum Analysis ◽  
Pressure Sensor ◽  
High Frequency ◽  
Pressure Wave ◽  
Hydraulic System ◽  
Output Voltage ◽  
Pressure Sensors ◽  
Innovative Technology ◽  
Wave Generator

This study developed a square-like pressure wave generator as an excitation source to test dynamic characteristics of pressure sensors. The developed generator can generate a square-like pressure wave of as high as 2 kHz and can achieve high-frequency switching by utilizing the differential principle through a series of mechanical rotations between the revolving spindle and revolving ring. The square-like pressure wave generated is input into the hydraulic system while the output voltage signals given by the pressure sensor can be analyzed by spectrum analysis to obtain dynamic characteristics of the pressure sensor

scholarly journals A Highly Sensitive and Flexible Capacitive Pressure Sensor Based on a Porous Three-Dimensional PDMS/Microsphere Composite

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1412 ◽  
Author(s):  
Young Jung ◽  
Wookjin Lee ◽  
Kyungkuk Jung ◽  
Byunggeon Park ◽  
Jinhyoung Park ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Sacrificial Layer ◽  
Three Dimensional ◽  
Pressure Sensors ◽  
Capacitive Pressure Sensor ◽  
Mechanical Stimuli ◽  
Highly Sensitive ◽  
Flexible Pressure Sensors ◽  
Fast Rise ◽  
Better Than

In recent times, polymer-based flexible pressure sensors have been attracting a lot of attention because of their various applications. A highly sensitive and flexible sensor is suggested, capable of being attached to the human body, based on a three-dimensional dielectric elastomeric structure of polydimethylsiloxane (PDMS) and microsphere composite. This sensor has maximal porosity due to macropores created by sacrificial layer grains and micropores generated by microspheres pre-mixed with PDMS, allowing it to operate at a wider pressure range (~150 kPa) while maintaining a sensitivity (of 0.124 kPa−1 in a range of 0~15 kPa) better than in previous studies. The maximized pores can cause deformation in the structure, allowing for the detection of small changes in pressure. In addition to exhibiting a fast rise time (~167 ms) and fall time (~117 ms), as well as excellent reproducibility, the fabricated pressure sensor exhibits reliability in its response to repeated mechanical stimuli (2.5 kPa, 1000 cycles). As an application, we develop a wearable device for monitoring repeated tiny motions, such as the pulse on the human neck and swallowing at the Adam’s apple. This sensory device is also used to detect movements in the index finger and to monitor an insole system in real-time.

scholarly journals Scalable Pressure Sensor Based on Electrothermally Operated Resonator

2017 ◽  
Author(s):  
Amal Z. Hajjaj ◽  
Md Abdullah Al Hafiz ◽  
Nouha Alcheikh ◽  
Mohammad I. Younis
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Surface Structures ◽  
Resonant Structure ◽  
Mems Resonator ◽  
Nonlinear Finite Element Model

We experimentally demonstrate a new pressure sensor that offers the flexibility of being scalable to small sizes up to the nano regime. Unlike conventional pressure sensors that rely on large diaphragms and big-surface structures, the principle of operation here relies on convective cooling of the air surrounding an electrothermally heated resonant structure, which can be a beam or a bridge. This concept is demonstrated using an electrothermally tuned and electrostatically driven MEMS resonator, which is designed to be deliberately curved. We show that the variation of pressure can be tracked accurately by monitoring the change in the resonance frequency of the resonator at a constant electrothermal voltage. We show that the range of the sensed pressure and the sensitivity of detection are controllable by the amount of the applied electrothermal voltage. Theoretically, we verify the device concept using a multi-physics nonlinear finite element model. The proposed pressure sensor is simple in principle and design and offers the possibility of further miniaturization to the nanoscale.

SIMULATION METHODS OF PIEZORESISTIVE PRESSURE SENSORS IN ORDER TO IMPROVE CONSISTENCY

2012 ◽  
Vol 27 (02) ◽  
pp. 1350011 ◽  
Author(s):  
ZHAOHUA ZHANG ◽  
TIANLING REN ◽  
RUIRUI HAN ◽  
LI YUAN ◽  
BO PANG
Keyword(s):  
Pressure Sensor ◽  
Pressure Sensors ◽  
Simulation Method ◽  
Test Results ◽  
Silicon Membrane ◽  
Element Analysis ◽  
Piezoresistive Pressure Sensor ◽  
Consistency Results ◽  
Good Consistency ◽  
Piezoresistive Pressure Sensors

It is important to realize good consistency among different device units on a big wafer. The bad product consistency results from the processing deviation which is hard to control. A novel simulation method to control and reduce the influence of processing deviation on the sensitivity of a piezoresistive pressure sensor is provided in this paper. Based on finite element analysis (FEA) and mathematical integration, the performance of the pressure sensors is simulated. The pressure sensors are designed and fabricated according to the simulation results. The test results confirm that this simulation method can help to design the pressure sensor very precisely. From the simulation and test results, we find that properly enlarging the size of the square silicon membrane can improve the devices consistency.

scholarly journals The simulation, fabrication technology and characteristic research of micro-pressure sensor with isosceles trapezoidal beam-membrane

2020 ◽  
Vol 34 (29) ◽  
pp. 2050285
Author(s):  
Jing Wu ◽  
Xiaofeng Zhao ◽  
Yibo Liu ◽  
Dianzhong Wen
Keyword(s):  
Pressure Sensor ◽  
Supply Voltage ◽  
Pressure Sensors ◽  
Simulation Models ◽  
Micro Electro Mechanical System ◽  
Fabrication Technology ◽  
Silicon Membrane ◽  
Pressure Sensitive ◽  
Mems Technology ◽  
Sensitive Characteristics

A micro-pressure sensor with an isosceles trapezoidal beam-membrane (ITBM) is proposed in this paper, consisting of a square silicon membrane, four isosceles trapezoidal beams (ITBs) and four piezoresistors. To investigate how the elastic silicon membrane affects pressure sensitive characteristics, simulation models based on ANSYS 15.0 software were used to analyze the effect of structural dimension on the characteristics of pressure sensor. According to that, the chips of micro-pressure sensors were fabricated by micro-electro-mechanical system (MEMS) technology on a silicon wafer with [Formula: see text] orientation. The experimental results show that the proposed sensor achieves a better sensitivity of 9.64 mV/kPa and an excellent linearity of 0.09%F.S. in the range of 0–3.0 kPa at room temperature and a supply voltage of 5.0 V, with a super temperature coefficient of sensitivity (TCS) about - 2180 ppm/[Formula: see text] from −40[Formula: see text] to 85[Formula: see text] and low pressure measurement less than 3.0 kPa.

scholarly journals Array model of shock pressure sensor for shooting point detection

2022 ◽  
Vol 355 ◽  
pp. 01027
Author(s):  
Changlong Zhou ◽  
Yingjun Li ◽  
Guicong Wang ◽  
Xue Yang
Keyword(s):  
Shock Wave ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
Element Model ◽  
Calculation Model ◽  
Shock Pressure ◽  
Detection Accuracy ◽  
Point Calculation ◽  
Point Detection ◽  
To Receive

The array model of double-T shock pressure sensor is established. Shock wave is produced by a supersonic object in the air. Pressure is produced in the process of shock wave transmission. Different shock pressure sensors have different time to receive the pressure signal. In this paper, the shooting point calculation model and the finite element model of the double T-shaped array method are established. The simulation experiment is carried out. The law of shock wave propagation is verified. The model can be used to calculate the coordinates of shooting point quickly. This method is suitable for small angle oblique fire location problem, and improves the detection accuracy of shooting point.

Flexible pressure sensor with a “V-type” array microelectrode on a grating PDMS substrate

Sensor Review ◽  
2016 ◽  
Vol 36 (4) ◽  
pp. 397-404 ◽  
Author(s):  
Jianli Cui ◽  
Junping Duan ◽  
Binzhen Zhang ◽  
Xueli Nan
Keyword(s):  
Pressure Sensor ◽  
Nanoimprint Lithography ◽  
Pressure Sensors ◽  
Weight Ratio ◽  
Master Mold ◽  
Pdms Substrate ◽  
Cycle Stability ◽  
Molding Process ◽  
Content Type ◽  
Array Structure

Purpose This paper aims to provide a fabrication and measurement of a highly stretchable pressure sensor with a “V-type” array microelectrode on a grating PDMS substrate. Design/methodology/approach First, the “V-type” array structure on the silicon wafer was fabricated by the MEMS technology, and the fabrication process included ultra-violet lithography and silicon etching. The “V-type” array structure on the master mold was then replicated into polycarbonate, which served as an intermediate, negative mold, using a conventional nanoimprint lithography technique. The negative mold was subsequently used in the PDMS molding process to produce PDMS “V-type” array structures with the same structures as the master mold. An Ag film was coated on the PDMS “V-type” array structure surface by the magnetron sputtering process to obtain PDMS “V-type” array microelectrodes. Finally, a PDMS prepolymer was prepared using a Sylgard184 curing agent with a weight ratio of a 20:1 and applied to the cavity at the middle of the two-layer PDMS “V-type” array microelectrode template to complete hot-press bonding, and a pressure sensor was realized. Findings The experimental results showed that the PDMS “V-type” array microelectrode has high stretchability of 65 per cent, temperature stability of 0.0248, humidity stability of 0.000204, bending stability and cycle stability. Capacitive pressure sensors with a “V-type” array microelectrode exhibit ideal initial capacitance (111.45 pF), good pressure sensitivity of 0.1143 MPa-1 (0-0.35 Mpa), fast response and relaxation times (<200 ms), high bending stability, high temperature/humidity stability and high cycle stability. Originality/value The PDMS “V-type” array structure microelectrode can be used to fabricate pressure sensors and is highly flexible, crack-free and durable.

Development of circuit solution and design of capacitive pressure sensor array for applied robotics

2020 ◽  
Vol 8 (4) ◽  
pp. 296-307
Author(s):  
Konstantin Krestovnikov ◽  
Aleksei Erashov ◽  
Аleksandr Bykov
Keyword(s):  
Pressure Sensor ◽  
Output Signal ◽  
Sensor Array ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Fine Tuning ◽  
Capacitive Pressure Sensor ◽  
Cell Parameters ◽  
Linear Pattern ◽  
Sensor Structure

This paper presents development of pressure sensor array with capacitance-type unit sensors, with scalable number of cells. Different assemblies of unit pressure sensors and their arrays were considered, their characteristics and fabrication methods were investigated. The structure of primary pressure transducer (PPT) array was presented; its operating principle of array was illustrated, calculated reference ratios were derived. The interface circuit, allowing to transform the changes in the primary transducer capacitance into voltage level variations, was proposed. A prototype sensor was implemented; the dependency of output signal power from the applied force was empirically obtained. In the range under 30 N it exhibited a linear pattern. The sensitivity of the array cells to the applied pressure is in the range 134.56..160.35. The measured drift of the output signals from the array cells after 10,000 loading cycles was 1.39%. For developed prototype of the pressure sensor array, based on the experimental data, the average signal-to-noise ratio over the cells was calculated, and equaled 63.47 dB. The proposed prototype was fabricated of easily available materials. It is relatively inexpensive and requires no fine-tuning of each individual cell. Capacitance-type operation type, compared to piezoresistive one, ensures greater stability of the output signal. The scalability and adjustability of cell parameters are achieved with layered sensor structure. The pressure sensor array, presented in this paper, can be utilized in various robotic systems.

scholarly journals Simulation and Nonlinearity Optimization of a High-Pressure Sensor

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4419
Author(s):  
Ting Li ◽  
Haiping Shang ◽  
Weibing Wang
Keyword(s):  
High Pressure ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
Original Model ◽  
Ansys Software ◽  
Nonlinear Error ◽  
Sensor Model ◽  
Optimized Model ◽  
Simulation Results ◽  
Better Than

A pressure sensor in the range of 0–120 MPa with a square diaphragm was designed and fabricated, which was isolated by the oil-filled package. The nonlinearity of the device without circuit compensation is better than 0.4%, and the accuracy is 0.43%. This sensor model was simulated by ANSYS software. Based on this model, we simulated the output voltage and nonlinearity when piezoresistors locations change. The simulation results showed that as the stress of the longitudinal resistor (RL) was increased compared to the transverse resistor (RT), the nonlinear error of the pressure sensor would first decrease to about 0 and then increase. The theoretical calculation and mathematical fitting were given to this phenomenon. Based on this discovery, a method for optimizing the nonlinearity of high-pressure sensors while ensuring the maximum sensitivity was proposed. In the simulation, the output of the optimized model had a significant improvement over the original model, and the nonlinear error significantly decreased from 0.106% to 0.0000713%.

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