Limits...
A Wireless Passive LC Resonant Sensor Based on LTCC under High-Temperature/Pressure Environments.

Qin L, Shen D, Wei T, Tan Q, Luo T, Zhou Z, Xiong J - Sensors (Basel) (2015)

Bottom Line: Through the theoretical analysis of the sensor structure model, it is found that the increase in the dielectric constant and the decrease in the Young's modulus of DuPont 951 ceramic are the main causes that affect the pressure signal in high-temperature measurement.Through calculations, the Young's modulus of DuPont 951 ceramic is found to decrease rapidly from 120 GPa to 65 GPa within 400 °C.Finally, a temperature compensation structure is proposed and fabricated, and the pressure response after temperature compensation illustrates that temperature drift is significantly reduced compared with that without the temperature compensation structure, which verifies the feasibility the proposed temperature compensation structure.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China. qinli@nuc.edu.cn.

ABSTRACT
In this work, a wireless passive LC resonant sensor based on DuPont 951 ceramic is proposed and tested in a developed high-temperature/pressure complex environment. The test results show that the measured resonant frequency varies approximately linearly with the applied pressure; simultaneously, high temperature causes pressure signal drift and changes the response sensitivity. Through the theoretical analysis of the sensor structure model, it is found that the increase in the dielectric constant and the decrease in the Young's modulus of DuPont 951 ceramic are the main causes that affect the pressure signal in high-temperature measurement. Through calculations, the Young's modulus of DuPont 951 ceramic is found to decrease rapidly from 120 GPa to 65 GPa within 400 °C. Therefore, the LC resonant pressure sensor needs a temperature compensation structure to eliminate the impact of temperature on pressure measurement. Finally, a temperature compensation structure is proposed and fabricated, and the pressure response after temperature compensation illustrates that temperature drift is significantly reduced compared with that without the temperature compensation structure, which verifies the feasibility the proposed temperature compensation structure.

No MeSH data available.


Main fabrication processes of the pressure sensor.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4541903&req=5

sensors-15-16729-f001: Main fabrication processes of the pressure sensor.

Mentions: Figure 1 shows the main fabrication processes of the pressure sensor, which is composed of five layers of green tape. First, the via, exhaust hole, and air cavity are formed by punching on corresponding layers, then the via is filled with metal silver, in order to connect the patterns on different layers; Second, layers 1 and 3 are screen printed with the corresponding sliver patterns; Third, a carbon membrane is added into the cavity, to protect the sensitive membrane from collapse. Fourth, all the tapes are stacked in proper order and laminated into a unit. Fifth, the whole structure is sintered in a furnace according to the time-temperature curve set in advance; during the sintering, the carbon membrane is evaporated into the air through the exhaust hole; Finally, the structure is co-fired in a furnace again, to seal the exhausting hole by glass frit. The fabricated pressure sensor is illustrated in Figure 2 and the main sensor dimensions are listed in Table 1.


A Wireless Passive LC Resonant Sensor Based on LTCC under High-Temperature/Pressure Environments.

Qin L, Shen D, Wei T, Tan Q, Luo T, Zhou Z, Xiong J - Sensors (Basel) (2015)

Main fabrication processes of the pressure sensor.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541903&req=5

sensors-15-16729-f001: Main fabrication processes of the pressure sensor.
Mentions: Figure 1 shows the main fabrication processes of the pressure sensor, which is composed of five layers of green tape. First, the via, exhaust hole, and air cavity are formed by punching on corresponding layers, then the via is filled with metal silver, in order to connect the patterns on different layers; Second, layers 1 and 3 are screen printed with the corresponding sliver patterns; Third, a carbon membrane is added into the cavity, to protect the sensitive membrane from collapse. Fourth, all the tapes are stacked in proper order and laminated into a unit. Fifth, the whole structure is sintered in a furnace according to the time-temperature curve set in advance; during the sintering, the carbon membrane is evaporated into the air through the exhaust hole; Finally, the structure is co-fired in a furnace again, to seal the exhausting hole by glass frit. The fabricated pressure sensor is illustrated in Figure 2 and the main sensor dimensions are listed in Table 1.

Bottom Line: Through the theoretical analysis of the sensor structure model, it is found that the increase in the dielectric constant and the decrease in the Young's modulus of DuPont 951 ceramic are the main causes that affect the pressure signal in high-temperature measurement.Through calculations, the Young's modulus of DuPont 951 ceramic is found to decrease rapidly from 120 GPa to 65 GPa within 400 °C.Finally, a temperature compensation structure is proposed and fabricated, and the pressure response after temperature compensation illustrates that temperature drift is significantly reduced compared with that without the temperature compensation structure, which verifies the feasibility the proposed temperature compensation structure.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China. qinli@nuc.edu.cn.

ABSTRACT
In this work, a wireless passive LC resonant sensor based on DuPont 951 ceramic is proposed and tested in a developed high-temperature/pressure complex environment. The test results show that the measured resonant frequency varies approximately linearly with the applied pressure; simultaneously, high temperature causes pressure signal drift and changes the response sensitivity. Through the theoretical analysis of the sensor structure model, it is found that the increase in the dielectric constant and the decrease in the Young's modulus of DuPont 951 ceramic are the main causes that affect the pressure signal in high-temperature measurement. Through calculations, the Young's modulus of DuPont 951 ceramic is found to decrease rapidly from 120 GPa to 65 GPa within 400 °C. Therefore, the LC resonant pressure sensor needs a temperature compensation structure to eliminate the impact of temperature on pressure measurement. Finally, a temperature compensation structure is proposed and fabricated, and the pressure response after temperature compensation illustrates that temperature drift is significantly reduced compared with that without the temperature compensation structure, which verifies the feasibility the proposed temperature compensation structure.

No MeSH data available.