Finite element analysis on the quartz plate due to the placement of quartz crystal microbalance on printed circuit board

Abstract

Quartz Crystal Microbalance (QCM) is a high sensitivity piezoelectric sensor that enables it to detect loads in the nanogram order. QCM usually consists of a thin quartz plate with an AT-cut orientation. The sensor resonance frequency and its stability are affected by the sensor parameter and its placement in the reaction cell. Previous studies have shown that the physical parameters and geometric shapes of the QCM sensor greatly affected the sensitivity and stability of the sensor. As the sensor is thin, only in the order of hundredths micrometer, pressure, or force on top of the sensor surface also affects the sensor resonance frequency. In this study, we conducted a deformation analysis due to the placement of QCM on the Printed Circuit Board (PCB). The simulation is done by Finite Element Method using ANSYS 19.2. Variations in the shape of the electrodes on the PCB and O-ring elastic modulus that used in the QCM system has been investigated O-rings that have a smaller elastic modulus that will cause greater deformation. From the two types of PCB electrodes, electrodes in the form of ¾ circular arcs give smaller deformations than electrodes in the form of ½ circular arcs. The deformation occurs in the order of 10−6 m.