A Novel Silicon Base Piezoresistive Pressure Sensor Using Front Side Etching Process

Author(s):  
Chih-Tang Peng ◽  
Ji-Cheng Lin ◽  
Chun-Te Lin ◽  
Kuo-Ning Chiang ◽  
Jin-Shown Shie

By applying the etching via technology, this study proposes a novel front-side etching fabrication process for a silicon based piezoresistive pressure sensor to replace the conventional backside bulk micro-machining. The distinguishing features of this novel structure are chip size reduction and fabrication costs degradation. In order to investigate the sensor performance and the sensor packaging effect of the structure proposed in this research, the finite element method was adopted for analyzing the sensor sensitivity and stability. The sensitivity and the stability of the novel sensor after packaging were studied by applying mechanical as well as thermal loading to the sensor. Furthermore, the fabrication process and the sensor performance of the novel pressure sensor were compared with the conventional back-side etching type pressure sensor for the feasibility validation of the novel sensor. The results showed that the novel pressure sensor provides better sensitivity than the conventional one, and the sensor output signal stability can be enhanced by better packaging structure designs proposed in this study. Based on the above findings, this novel structure pressure sensor shows a high potential for membrane type micro-sensor application.

Author(s):  
Chih-Tang Peng ◽  
Chang-Chun Lee ◽  
Kuo-Ning Chiang

In this study, a silicon base piezoresistive pressure sensor using flip chip and flex circuit packaging technologies is studied, designed and analyzed. A novel designed pressure sensor using flip chip packaging with spacer is employed to substitute the conventional chip on board or SOP packaging technology. Subsequently, a finite element method (FEM) is adopted for the designing of the sensor performance. Thermal and pressure loading is applied on the sensor to study the system sensitivity as well as the thermal and packaging effect. The performance of novel packaging pressure sensor is compared with that of the conventional one to demonstrate the feasibility of this novel design. The findings depict that this novel packaging design can not only maintain well sensor sensitivity but also reduce the thermal and packaging effect of the pressure sensor.


Author(s):  
Chih-Tang Peng ◽  
Ji-Cheng Lin ◽  
Chun-Te Lin ◽  
Kuo-Ning Chiang

In this study, a packaged silicon base piezoresistive pressure sensor with thermal stress buffer is designed, fabricated, and measured. A finite element method (FEM) is adopted for design and experimental validation of the sensor performance. Thermal and pressure loading on the sensor is applied to make a comparison between sensor experimental and simulation results. Furthermore, a method that transfers simulation stress data into output voltage is proposed in this study, the results indicate that the experimental result coincides with simulation data.


2020 ◽  
Vol 37 (3) ◽  
pp. 147-153
Author(s):  
Zoheir Kordrostami ◽  
Kourosh Hassanli ◽  
Amir Akbarian

Purpose The purpose of this study is to find a new design that can increase the sensitivity of the sensor without sacrificing the linearity. A novel and very efficient method for increasing the sensitivity of MEMS pressure sensor has been proposed for the first time. Rather than perforation, we propose patterned thinning of the diaphragm so that specific regions on it are thinner. This method allows the diaphragm to deflect more in response with regard to the pressure. The best excavation depth has been calculated and a pressure sensor with an optimal pattern for thinned regions has been designed. Compared to the perforated diaphragm with the same pattern, larger output voltage is achieved for the proposed sensor. Unlike the perforations that have to be near the edges of the diaphragm, it is possible for the thin regions to be placed around the center of the diaphragm. This significantly increases the sensitivity of the sensor. In our designation, we have reached a 60 per cent thinning (of the diaphragm area) while perforations larger than 40 per cent degrade the operation of the sensor. The proposed method is applicable to other MEMS sensors and actuators and improves their ultimate performance. Design/methodology/approach Instead of perforating the diaphragm, we propose a patterned thinning scheme which improves the sensor performance. Findings By using thinned regions on the diaphragm rather than perforations, the sensitivity of the sensor was improved. The simulation results show that the proposed design provides larger membrane deflections and higher output voltages compared to the pressure sensors with a normal or perforated diaphragm. Originality/value The proposed MEMS piezoelectric pressure sensor for the first time takes advantage of thinned diaphragm with optimum pattern of thinned regions, larger outputs and larger sensitivity compared with the simple or perforated diaphragm pressure sensors.


Author(s):  
Chun-Te Lin ◽  
Chih-Tang Peng ◽  
Ji-Cheng Lin ◽  
Kuo-Ning Chiang

In this study, a packaged silicon based piezoresistive pressure sensor is designed, fabricated, and studied. A finite element method (FEM) is adopted for designing and optimizing the sensor performance. Thermal as well as pressure loading on the sensor is applied to make a comparison between experimental and simulation results. Furthermore, a method that transfers the simulation stress data into output voltage is proposed in this study, and the results indicate that the experimental result coincides with the simulation data. In order to achieve better sensor performance, a parametric analysis is performed to evaluate the system output sensitivity of the pressure sensor. The design parameters of the pressure sensor include membrane size/shape and the location of piezoresistor. The findings depict that proper selection of the membrane geometry and piezoresistor location can enhance the sensor sensitivity.


2009 ◽  
Vol 60-61 ◽  
pp. 68-73 ◽  
Author(s):  
Cheng Pang ◽  
Zhan Zhao ◽  
Li Shi ◽  
Li Dong Du ◽  
Zhen Fang

An excellent pressure sensor based a simple fabrication technology is presented. Differently from the present prevailing fabrication process of silicon piezoresistive pressure sensor: platinum is used as the sensing material, with a smaller but acceptable sensitivity and much simpler processes; adhesive bonding with SU-8 is used as an alternative choice to anodic bonding, and we choose a vacuum hot plate to avoid using a bonding machine. To achieve a successful bonding, it is found that pre-bake time and pumping time are the most important factors. Bonding quality is evaluated by inspection through the glass with 95% of the area successfully bonded and the failed area in the edge of the wafers. The measured bonding strength is 17.34 MPa. The Pressure-Voltage characteristic test results display a good linearity within 0.2% and especially a good precision within 0.035% in square fitting. The temperature drifting is also tested and the TCO is 1250 ppm/(°C FSO). The long-term stability of the sensor at a constant pressure is a fluctuation within 40 Pa (0.098% FSO) in 7 days. Both the simple fabrication process and the excellent performance of the sensor suggest that this sensor is a much good choice in measuring atmospheric pressure.


2021 ◽  
Author(s):  
REKHA DEVI ◽  
Sandeep Singh Gill

Abstract In silicon-based piezoresistive pressure sensor, the accuracy of the sensor is affected mainly by thermal drift and the sensitivity of the sensor varies with the rise in temperature. Here, the temperature effects on the desired representation of the sensor are analysed .Use of smart material Carbon nanotubes ( CNT) and a few effective temperature compensation techniques are presented in this study to reduce the temperature effect on the accuracy of the sensor. Resistive compensation employed extra piezoresistors with Negative Temperature Coefficient of Resistivity (TCR) for temperature compensation. The attainment of the desired compensation techniques is highly compatible with the MEMS device fabrication. The compensated pressure sensor is supremacy for pressure measurement with temperature variations. Though various techniques have been suggested and put into actuality with successful attainment, the techniques featuring easy implementation and perfect compatibility with existing schemes are still blooming demanded to design a piezoresistive pressure sensor with perfect comprehensive performance. In this paper, CNT piezoresistive material has been employed as sensing elements for pressure sensor and compared with silicon in terms of output voltage and sensor performance degradation at higher temperature. Pressure sensors using CNT and silicon piezo resistive sensing materials were simulated on silicon (100) diaphragm by ANYSIS. Based on simulation results, silicon and CNT both pressure sensor also shows better results at near room temperature. With the increasing temperature it is observed that silicon pressure output underestimated by 23%.


2013 ◽  
Vol 694-697 ◽  
pp. 497-502
Author(s):  
Jiang Tao Gai ◽  
Shou Dao Huang ◽  
Guang Ming Zhou ◽  
Yi Yuan

In order to search after a new way of the propulsion system of tracked vehicle, a novel structure form of electro-mechanical transmission was developed in this paper, through analyzing the advantages and disadvantages of existing projects of electric drive system for tracked vehicle. It could increase the rate of power exertion obviously and synthesize the mechanical and electrical strongpoint. And based on the structure form, an electro-mechanical transmission was designed with double electromotor added planetary mechanism of steering power coupling and gearshift, considering engineering realization. And then straight-line driving and steering performances of the transmission were calculated which proved that the novel electro-mechanical transmission could meet the requirement of tracked vehicle propulsion well.


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