Chapter 1 Investigation on micro contact in Cu-Cu wire bonding process 001 1.1 Introduction 001 1.2 Molecular dynamics modeling of Cu-Cu wire bonding 003 1.3 Results and discussions 005 1.3.1 Formation and breakage processes of Cu-Cu weld 005 1.3.2 Analysis of Cu-Cu indentation morphology 007 1.3.3 Analysis of Cu-Cu atomic stress distribution 008 1.4 Conclusions 011 References 011 Chapter 2 Investigation on wire bonding performance with six typical material pairs 014 2.1 Introduction 015 2.2 Molecular dynamics modeling of six material pairs 016 2.3 Results and discussions 018 2.3.1 Analysis of bonding forces and system energy 018 2.3.2 Analysis of atomic morphology for six material pairs 022 2.3.3 Analysis of atomic stress distribution for six material pairs 023 2.3.4 Four critical displacement points of six material pairs 025 2.4 Conclusions 028 References 028 ? Chapter 3 Investigation on residual stress on chip of automobile pressure sensor in potting process 032 3.1 Introduction 032 3.2 Thermal experiment of MEMS pressure sensor 034 3.3 Analytic analysis of thermal stress on sensitive structure 036 3.4 Modeling and Simulation 038 3.4.1 Geometric model of MEMS pressure sensor 039 3.4.2 Finite element model of MEMS pressure sensor 039 3.4.3 Finite element simulation of residual stress 040 3.5 Conclusions 044 References 045 Chapter 4 Investigation on thermal cycle failure of wire bonding weld in automobile pressure sensor 047 4.1 Introduction 048 4.2 Thermal cycling experiments of the MEMS pressure sensor 049 4.2.1 A sample of thermal cycling test 049 4.2.2 Experimental methods of the thermal fatigue test 050 4.2.3 Experimental results and analysis under thermal cycles 052 4.3 Numerical simulation 053 4.3.1 Theoretical model of thermal fatigue 053 4.3.2 Geometric model of the MEMS pressure sensor 055 4.3.3 Simulation model of thermal fatigue of solder joint 056 4.3.4 Simulation results of solder joint failures 058 4.4 Conclusions 062 References 063 Chapter 5 Investigation on acoustic injection on automobile MEMS accelerometer 066 5.1 Introduction 066 5.2 Experimental investigation of acoustic injection 068 5.3 Modeling and simulation 070 5.3.1 Disassembly of inertial measurement unit (IMU) MPU6050 070 5.3.2 Geometric model of accelerometer unit 070 5.3.3 Finite element model of accelerometer sensitive structure 072 5.3.4 Simulation results and discussion of acoustic injection 074 5.4 Conclusions 080 References 081 Chapter 6 Investigation on wetting behavior of Sn droplet on FPCB substrate surfaces 083 6.1 Introduction 083 6.2 Models and methods of different surfaces 085 6.2.1 Modified embed atom method (MEAM) potential 086 6.2.2 Simulation models of different surfaces 087 6.2.3 Experimental procedures of wetting behavior on different surfaces 090 6.3 Results and discussion 090 6.3.1 Effect of temperature on wetting behavior 090 6.3.2 Effect of roughness on wetting behavior 094 6.3.3 Effect of Sn surface on wetting behavior 097 6.3.4 Contact angle measurement on different substrate surfaces 101 6.4 Conclusions 103 References 103 Chapter 7 Investigation on etchant spraying characteristics in FPCB etching process 107 7.1 Introduction 108 7.2 Equipment of the FPCB etching process 110 7.3 Numerical simulation of multi-nozzle spraying system 111 7.3.1 Governing equations of fluid dynamics 111 7.3.2 Simulation model of spraying equipment 112 7.4 Results and discussions 114 7.5 Conclusions 122 References 123 ? Chapter 8 Investigation of etchant concentration distribution and fluid characteristics in FPCB etching cavity 126 8.1 Introduction 126 8.2 Model formulation and method of etching process 129 8.2.1 Governing equations of fluid dynamics and mass flux 129 8.2.2 Simulation model of the FPCB etching cavity 130 8.3 Results and discussions 133 8.4 Conclusions 140 References 140 Chapter 9 Investigation of etching cavity evolution in FPCB etching process 143 9.1 Introduction 143 9.2 Equipment of the FPCB etching process 144 9.3 Numerical simulat