The basic force and bonding energy in wafer bonding have been revealed in this study. The basic cause for bonding contributes to the interatomic attractive forces between surfaces or the reduction of surface energies....The basic force and bonding energy in wafer bonding have been revealed in this study. The basic cause for bonding contributes to the interatomic attractive forces between surfaces or the reduction of surface energies. The amplitude of roughness component can not exceed the criterion if wafer pair is bondable. The bonding behavior and challenge during annealing have been investigated.展开更多
An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great ...An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great potential for air-coupled applications,mainly because of their low acoustic impedance.In this study,an air-coupled CMUT array is designed as an air parametric array.A hexagonal array is proposed to improve the directivity of the sound generated.A finite element model of the CMUT is established in COMSOL software to facilitate the choice of appropriate structural parameters of the CMUT cell.The CMUT array is then fabricated by a wafer bonding process with high consistency.The performances of the CMUT are tested to verify the accuracy of the finite element analysis.By optimizing the component parameters of the bias-T circuit used for driving the CMUT,DC and AC voltages can be effectively applied to the top and bottom electrodes of the CMUT to provide efficient ultrasound transmission.Finally,the prepared hexagonal array is successfully used to conduct preliminary experiments on its application as an air parametric array.展开更多
文摘The basic force and bonding energy in wafer bonding have been revealed in this study. The basic cause for bonding contributes to the interatomic attractive forces between surfaces or the reduction of surface energies. The amplitude of roughness component can not exceed the criterion if wafer pair is bondable. The bonding behavior and challenge during annealing have been investigated.
基金the National Key R&D Program of China(Nos.2017YFA0205103 and 2018YFE020505)the National Natural Science Foundation of China(Nos.81571766 and 61771337)+1 种基金the Natural Science Foundation of Tianjin,China(No.17JCYBJC24400)the“111”Project of China(No.B07014).
文摘An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great potential for air-coupled applications,mainly because of their low acoustic impedance.In this study,an air-coupled CMUT array is designed as an air parametric array.A hexagonal array is proposed to improve the directivity of the sound generated.A finite element model of the CMUT is established in COMSOL software to facilitate the choice of appropriate structural parameters of the CMUT cell.The CMUT array is then fabricated by a wafer bonding process with high consistency.The performances of the CMUT are tested to verify the accuracy of the finite element analysis.By optimizing the component parameters of the bias-T circuit used for driving the CMUT,DC and AC voltages can be effectively applied to the top and bottom electrodes of the CMUT to provide efficient ultrasound transmission.Finally,the prepared hexagonal array is successfully used to conduct preliminary experiments on its application as an air parametric array.
