工学博士学位论文基于钎料润湿力的光纤自对准原理及.pdf

国内图书分类号 TG 409 国际图书分类号 621 791 工学博士学位论文 基于钎料润湿力的光纤自对准原理及 激光软钎焊界面反应 博 士 研 究 生 张威 导 师 王春青教授 申 请 学 位 工学博士 学 科 专 业 材料加工工程 所 在 单 位 材料科学与工程学院 答 辩 日 期 2008 年 8 月 授予学位单位 哈尔滨工业大学 Classified Index TG 409 U D C 621 791 Dissertation for the Doctoral Degree in Engineering PRINCIPLE OF FIBER SELF ALIGNMENT USING WETTING FORCE OF SOLDER AND INTERFACIAL REACTIONS IN LASER SOLDERING Candidate Zhang Wei Supervisor Prof Wang Chunqing Academic Degree Applied for Doctor of Engineering Specialty Material Processing Engineering Affiliation Department of Materials Sci The flower like Au Ni 3Sn2 formed near the interface of AuSn Au Ni Cu as well as AuSn Au Ni began to dissolve into the ambient phase and disappear during aging at the same time 哈尔滨工业大学工学博士学位论文 IV the content of Ni in phase increased Based on the reasonable hypothesis the mathematical model of three dimensional 3 D shape of solder joint in fiber attachment soldering was established the energy the volume and the boundary condition of solder joint shape was described in reason 3 D shape of solder joint was calculated by employing finite element method FEM and the influence of material and structure factors on 3 D shape of solder joint was analyzed The results showed that the extent of solder wetting on fiber increased with the increase of solder volume and the decrease of pad size With the increase of aspect ratio of pad the bending extent of curve at cross section increased The 3 D shape of solder joint was measured by laser scanning confocal Microscope LSCM and the results were compared with those of calculated the results showed that the measured results of 3 D shape of solder joint were in accordance with the calculated results and the method of calculating and measuring of 3 D shape of solder joint was reasonable and credible The formulation of self alignment driving force was deduced theoretically by analyzing the force acting on fiber Base on the formula the restoring force and normal reaction force could be calculated which mainly depended on the wetting force acting on fiber by solder and the hydrostatic pressure could be ignored The theoretical equilibrium positions of pad with different shape were calculated by FEM and the influences of material and structure factors on self alignment restoring force and restoring torque were analyzed The results showed that the self alignment restoring force changed linearly with horizontal offset and the restoring torque changed linearly with yaw angle Bigger solder volume within limits bigger aspect ratio of pad bigger surface tension of solder and smaller solder pad contact angle were propitious to the self alignment for horizontal offset while smaller solder volume within limits bigger aspect ratio of pad bigger surface tension of solder and smaller solder fiber contact angle were propitious to the self alignment for yaw angle Calculation results on stand off height SOH between fiber and pad showed that the SOH existed when the solder volume exceeded the critical volume SOH increased with the decrease of pad size the decrease of aspect ratio and the increase of solder fiber contact angle SOH was measured by LSCM and the Abstract V measured results were in accordance with the calculated results Keywords optoelectronic packaging fiber attachment soldering intermetallic compound 3 D shape of solder joint self alignment 哈尔滨工业大学工学博士学位论文 VI 目录 摘要 Abstract 第 1 章 绪论 1 1 1 课题背景及选题意义 1 1 2 有源对准技术的研究现状 2 1 3 无源对准技术的研究现状 7 1 4 新方法的设想 10 1 5 AuSn 钎料 焊盘界面反应的研究现状 11 1 6 自对准技术的研究现状 13 1 7 课题来源及研究内容 16 第 2章 光纤定位激光软钎焊工艺 17 2 1 试验研究过程 17 2 2 试验材料 17 2 3 试验方法及设备 19 2 3 1 激光软钎焊 19 2 3 2 老化试验 20 2 3 3 焊点形态观察与测量 20 2 3 4 SEM 及 EDX 界面组织分析 22 2 3 5 理论平衡位置测量 22 2 4 激光软钎焊工艺试验及界面反应分析 24 2 4 1 激光软钎焊工艺参数 24 2 4 2 激光软钎焊界面反应分析 25 2 5 老化后 Au Ni AuSn Au Ti 焊点界面微观组织 28 2 5 1 老化后 AuSn Au Ti 界面微观组织 28 2 5 2 老化后 AuSn Au Ni 界面微观组织 29 2 6 老化后 Au Ni AuSn Au Ni Cu 焊点界面微观组织 31 2 6 1 老化后 AuSn Au Ni Cu 界面微观组织 31 2 6 2 老化后 AuSn Au Ni 界面微观组织 34 2 7 本章小结 36 目 录 VII 第 3 章 光纤定位钎焊熔融钎料液面三维形态计算 37 3 1 焊点三维形态模型及其数学描述 37 3 1 1 基本假设 37 3 1 2 焊点三维形态的能量控制方程 38 3 2 有限元程序 40 3 3 焊点三维形态计算输入参数 40 3 3 1 AuSn 钎料的密度 40 3 3 2 AuSn 钎料在镀金层上的接触角 41 3 3 3 AuSn 钎料的表面张力系数 41 3 4 焊点形态计算结果与分析 43 3 4 1 焊点三维形态初始单元划分 43 3 4 2 能量与体积描述 44 3 4 3 计算结果与分析 46 3 4 4 尺寸放大对焊点三维形态的影响 55 3 5 试验验证结果与分析 59 3 6 本章小结 61 第 4 章 光纤自对准原理及焊盘结构设计 63 4 1 光纤的受力分析 63 4 1 1 光纤二维受力分析 63 4 1 2 光纤三维受力分析 69 4 2 光纤自对准原理 71 4 3 焊盘结构设计 72 4 3 1 理论平衡位置的计算 72 4 3 2 理论平衡位置的试验验证 76 4 3 3 焊盘设计准则 79 4 4 回复转矩的影响因素 79 4 5 回复力的影响因素 83 4 6 本章小结 85 第5章 光纤与焊盘间隙高度计算结果与分析 87 5 1 间隙高度计算方法 87 5 2 间隙高度计算结果与分析 88 5 2 1 相关因素对间隙高度的影响 88 5 2 2 间隙高度回归模型 90 哈尔滨工业大学工学博士学位论文 VIII 5 3 间隙高度计算结果试验验证 91 5 4 本章小结 93 结论 94 参考文献 96 附录 106 攻读学位期间发表的学术论文 117 哈尔滨工业大学博士学位论文原创性声明 118 哈尔滨工业大学博士学位论文使用授权书 118 致谢 119 个人简历 120 Contents IX Contents Abstract in Chinese Abstract in English Chapter 1 Introduction 1 1 1 Background and Significance of Research 1 1 2 Research Status on Active Alignment Technology 2 1 3 Research Status on Passive Alignment Technology 7 1 4 New Method Tentative Plan 10 1 5 Interfacial Reactions between AuSn Solder Alloy and Pad 11 1 6 Research Status on Self Alignment Technology 13 1 7 Origin of Research and Contents of the Dissertation 16 Chapter 2 Laser Soldering Process for Fiber Attachment 17 2 1 Experimental Research Process 17 2 2 Experimental Materials 17 2 3 Experimental Method and Devices 19 2 3 1 Laser Soldering 19 2 3 2 Aging Process 20 2 3 3 Observation and Measurement of Solder Joint 20 2 3 4 Analysis of Interfacial Microstructure by SEM and EDX 22 2 3 5 Measurement of Theoretical Equilibrium Position 22 2 4 Laser Soldering Process and Analysis of Interfacial Reactions 24 2 4 1 Processing Parameters of Laser Soldering 24 2 4 2 Analysis of Interfacial Reactions by Laser Soldering 25 2 5 Interfacial Microstructure of Au Ni AuSn Au Ti Solder Joint after Aging 28 2 5 1 Microstructure at AuSn Au Ti Interface after Aging 28 2 5 2 Microstructure at AuSn Au Ni Interface after Aging 29 2 6 Interfacial Microstructure of Au Ni AuSn Au Ni Cu Solder Joint after Aging 31 2 6 1 Microstructure at AuSn Au Ni Cu Interface after Aging 31 哈尔滨工业大学工学博士学位论文 X 2 6 2 Microstructure at AuSn Au Ni Interface after Aging 34 2 7 Summary 36 Chapter 3 3 D Calculation of Molten Solder Surface in Fiber Attachment Soldering 37 3 1 3 D Model and Mathematic Description of Solder Joint 37 3 1 1 Basic Hypothesis 37 3 1 2 Energy Control Equation of 3 D Solder Joint Shape 38 3 2 FEM Program 40 3 3 Input Parameters for 3 D Solder Joint Shape Calculation 40 3 3 1 Mass Density of AuSn Solder 40 3 3 2 Contact Angle of AuSn Solder on Au Layer 41 3 3 3 Surface Tension Coefficient of AuSn Solder 41 3 4 Results and Analysis of 3 D Solder Joint Shape Calculaton 43 3 4 1 Initial Element Mesh of 3 D Solder Joint Shape 43 3 4 2 Energy and Volume Description 44 3 4 3 Results and Analysis of Calculation 46 3 4 4 Effects of Size Magnification on 3 D Solder Joint Shape 55 3 5 Results and Analysis of Experimental Validation 59 3 6 Summary 61 Chapter 4 Principle of Fiber Self Alignment and Design of Pad Structure 63 4 1 Analysis of Force Acting on Fiber 63 4 1 1 2 D Analysis of Force Acting on Fiber 63 4 1 2 3 D Analysis of Force Acting on Fiber 69 4 2 Principle o