TY - JOUR
T1 - The effect of electrical parameters of eddy current sensor on metal film thickness measurement performance and the optimization method
AU - Li, Hongkai
AU - Wang, Jinlong
AU - Zhang, Tong
AU - Li, Zihan
N1 - Publisher Copyright:
© 2023 Author(s).
PY - 2023/10/1
Y1 - 2023/10/1
N2 - Eddy current sensors have been widely used in the field of micro- and nano-measurements. The detection circuit is a key part of eddy current sensors. In particular, the electrical parameters in the signal conversion circuit have an important effect on the measurement performance. It is necessary to study the effect of the electrical parameters on the measurement performance and propose an optimization method. In this study, a simulation model of the eddy current sensor is established by coupling a magnetic field and a circuit field. The circuits include the LC parallel resonance, the AC bridge, and three combination circuits of the LC resonant and AC bridge. The output voltage variation with the thickness of copper film is calculated, and the effect of the electrical parameters on sensitivity Ki is obtained. In the LC parallel resonant circuit, it’ is revealed that K1 is maximum when the parallel capacitance CP is equal to the resonant capacitance C0. An optimization method of adjusting resistance RS in different thickness intervals is proposed. In the AC bridge circuit, it’ is revealed that there exists an optimal RS, which makes K2 maximum. In three combination circuits, K3, K4, and K5 are the maximum when the capacitances (C1, C2, and C3) reach the resonant capacitance C0. In addition, the sensitivity of each combination circuit is improved compared with that of the AC bridge. The relevant analysis results are further verified by a series of experiments. According to the calculation results and the experimental analysis, the optimization method for electrical parameters is further proposed.
AB - Eddy current sensors have been widely used in the field of micro- and nano-measurements. The detection circuit is a key part of eddy current sensors. In particular, the electrical parameters in the signal conversion circuit have an important effect on the measurement performance. It is necessary to study the effect of the electrical parameters on the measurement performance and propose an optimization method. In this study, a simulation model of the eddy current sensor is established by coupling a magnetic field and a circuit field. The circuits include the LC parallel resonance, the AC bridge, and three combination circuits of the LC resonant and AC bridge. The output voltage variation with the thickness of copper film is calculated, and the effect of the electrical parameters on sensitivity Ki is obtained. In the LC parallel resonant circuit, it’ is revealed that K1 is maximum when the parallel capacitance CP is equal to the resonant capacitance C0. An optimization method of adjusting resistance RS in different thickness intervals is proposed. In the AC bridge circuit, it’ is revealed that there exists an optimal RS, which makes K2 maximum. In three combination circuits, K3, K4, and K5 are the maximum when the capacitances (C1, C2, and C3) reach the resonant capacitance C0. In addition, the sensitivity of each combination circuit is improved compared with that of the AC bridge. The relevant analysis results are further verified by a series of experiments. According to the calculation results and the experimental analysis, the optimization method for electrical parameters is further proposed.
UR - http://www.scopus.com/inward/record.url?scp=85174242674&partnerID=8YFLogxK
U2 - 10.1063/5.0154824
DO - 10.1063/5.0154824
M3 - Article
C2 - 37791861
AN - SCOPUS:85174242674
SN - 0034-6748
VL - 94
JO - Review of Scientific Instruments
JF - Review of Scientific Instruments
IS - 10
M1 - 105001
ER -