SOLIDIFICATION AND MICROSEGREGATION BEHAVIORS OF NICKEL-BASE SINGLE CRYSTAL SUPERALLOY SOLIDIFIED AT MEDIUM COOLING RATE

ＳＯＬＩＤＩＦＩＣＡＴＩＯＮＡＮＤＭＩＣＲＯＳＥＧＲＥＧＡＴＩＯＮＢＥＨＡＶＩＯＲＳＯＦＮＩＣＫＥＬＢＡＳＥＳＩＮＧＬＥＣＲＹＳＴＡＬＳＵＰＥＲＡＬＬＯＹＳＯＬＩＤＩＦＩＥＤＡＴＭＥＤＩＵＭＣＯＯＬＩＮＧＲＡＴＥ①ＤｕＷｅｉ,ＬｉＪｉａｎｇｕｏａｎ...     

A FUZZY NEURAL NETWORK DECISION MODEL ON THE OPERATION PROCESS OF ELECTRIC FURNACE FOR CLEANING SLAG AND ITS APPLICATION

ＡＦＵＺＺＹＮＥＵＲＡＬＮＥＴＷＯＲＫＤＥＣＩＳＩＯＮＭＯＤＥＬＯＮＴＨＥＯＰＥＲＡＴＩＯＮＰＲＯＣＥＳＳＯＦＥＬＥＣＴＲＩＣＦＵＲＮＡＣＥＦＯＲＣＬＥＡＮＩＮＧＳＬＡＧＡＮＤＩＴＳＡＰＰＬＩＣＡＴＩＯＮ￥Ｐｅｎｇ，Ｘｉａｏｑｉ；Ｍｅｉ，Ｃｈｉ；Ｚｈ...     

MECHANICAL ANALYSIS AND NUMERICAL CALCULATION OF BONDING STRENGTH MEASUREMENT BY INTERFACIAL INDENTATION METHOD

ＭＥＣＨＡＮＩＣＡＬＡＮＡＬＹＳＩＳＡＮＤＮＵＭＥＲＩＣＡＬＣＡＬＣＵＬＡＴＩＯＮＯＦＢＯＮＤＩＮＧＳＴＲＥＮＧＴＨＭＥＡＳＵＲＥＭＥＮＴＢＹＩＮＴＥＲＦＡＣＩＡＬＩＮＤＥＮＴＡＴＩＯＮＭＥＴＨＯＤ①ＹｉＭａｏｚｈｏｎｇ１,ＨｕａｎｇＢａｉｙｕｎ１,...     

INTERACTION OF PARTICLES WITH A SOLIDIFIED INTERFACE DURING SOLIDIFICATION OF METAL MATRIX COMPOSITE REINFORCED WITH PARTICLES

ＩＮＴＥＲＡＣＴＩＯＮＯＦＰＡＲＴＩＣＬＥＳＷＩＴＨＡＳＯＬＩＤＩＦＩＥＤＩＮＴＥＲＦＡＣＥＤＵＲＩＮＧＳＯＬＩＤＩＦＩＣＡＴＩＯＮＯＦＭＥＴＡＬＭＡＴＲＩＸＣＯＭＰＯＳＩＴＥＲＥＩＮＦＯＲＣＥＤＷＩＴＨＰＡＲＴＩＣＬＥＳＣＨＵＳｈｕａｎｇｊｉｅ;Ｗ...     

THEORETICAL ANALYSIS AND DESIGN／CALCULATION FORMULAE FOR HYDRAULIC IMPACT MECHANISM

ＴＨＥＯＲＥＴＩＣＡＬＡＮＡＬＹＳＩＳＡＮＤＤＥＳＩＧＮ／ＣＡＬＣＵＬＡＴＩＯＮ　ＦＯＲＭＵＬＡＥＦＯＲ　ＨＹＤＲＡＵＬＩＣＩＭＰＡＣＴＭＥＣＨＡＮＩＳＭＨｅ；Ｑｉｎｇｈｕａ（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｃｈａｎｉｃａｌＥｎｇｉｎｅｅｒｉｎｇ，Ｃｅｎ...     

EFFECT OF P，S AND Si ON THE SOLIDIFICATION，SEGREGATION，MICROSTRUCTURE AND MECHANICAL PROPERTIES IN Fe－Ni BASE SUPERALLOYS

ＥＦＦＥＣＴＯＦＰ,ＳＡＮＤＳｉＯＮＴＨＥＳＯＬＩＤＩＦＩＣＡＴＩＯＮ,ＳＥＧＲＥＧＡＴＩＯＮ,ＭＩＣＲＯＳＴＲＵＣＴＵＲＥＡＮＤＭＥＣＨＡＮＩＣＡＬＰＲＯＰＥＲＴＩＥＳＩＮＦｅ－ＮｉＢＡＳＥＳＵＰＥＲＡＬＬＯＹＳＺ．Ｑ．Ｈｕ;Ｗ．Ｒ．ＳｕｎａｎｄＳ...     

SOLIDIFICATION OF Zn－Pb ALLOY UNDER SIMULANT MICROGRAVITY CONDITION OF ORTHOGONAL ELECTRIC AND MAGNETIC FIELDS

ＳＯＬＩＤＩＦＩＣＡＴＩＯＮＯＦＺｎ－ＰｂＡＬＬＯＹＵＮＤＥＲＳＩＭＵＬＡＮＴＭＩＣＲＯＧＲＡＶＩＴＹＣＯＮＤＩＴＩＯＮＯＦＯＲＴＨＯＧＯＮＡＬＥＬＥＣＴＲＩＣＡＮＤＭＡＧＮＥＴＩＣＦＩＥＬＤＳ￥Ｚｈａｏ，Ｊｉｕｚｈｏｕ；Ｇｕｏ，Ｊｉｎｇｊｉｅ；Ｊｉ...     

MOLECULAR STATIC SIMULATION OF ENERGY FEATURESOF INTERACTION BETWEEN GRAIN BOUNDARYAND DISLOCATIONS IN Ni＿3Al ALLOY

ＭＯＬＥＣＵＬＡＲＳＴＡＴＩＣＳＩＭＵＬＡＴＩＯＮＯＦＥＮＥＲＧＹＦＥＡＴＵＲＥＳＯＦＩＮＴＥＲＡＣＴＩＯＮＢＥＴＷＥＥＮＧＲＡＩＮＢＯＵＮＤＡＲＹＡＮＤＤＩＳＬＯＣＡＴＩＯＮＳＩＮＮｉ＿３ＡｌＡＬＬＯＹＣｈｅｎ，Ｄａ；Ｌｕ，Ｍｉｎ；Ｌｉｎ，Ｄｏｎｇ...     

THERMODYNAMIC AND STRUCTURAL CHEMISTRY DISCUSSIONS FOR OXIDATIVE LEACHING OF Cu－Ni SULPHIDE ORE UNDER ATMOSPHERIC PRESSURE

ＴＨＥＲＭＯＤＹＮＡＭＩＣＡＮＤＳＴＲＵＣＴＵＲＡＬＣＨＥＭＩＳＴＲＹＤＩＳＣＵＳＳＩＯＮＳＦＯＲＯＸＩＤＡＴＩＶＥＬＥＡＣＨＩＮＧＯＦＣｕ－ＮｉＳＵＬＰＨＩＤＥＯＲＥＵＮＤＥＲＡＴＭＯＳＰＨＥＲＩＣＰＲＥＳＳＵＲＥ￥Ｗｕ，Ｗｅｎｊｉａｎ（Ｄｅｐａｒ...     

MOLTEN SALT PHASE DIAGRAMS CALCULATION USING ARTIFICIAL NEURAL NETWORK OR PATTERN RECOGNITION-BOND PARAMETERS

ＭＯＬＴＥＮＳＡＬＴＰＨＡＳＥＤＩＡＧＲＡＭＳＣＡＬＣＵＬＡＴＩＯＮＵＳＩＮＧＡＲＴＩＦＩＣＩＡＬＮＥＵＲＡＬＮＥＴＷＯＲＫＯＲＰＡＴＴＥＲＮＲＥＣＯＧＮＩＴＩＯＮＢＯＮＤＰＡＲＡＭＥＴＥＲＳ①Ｐａｒｔ１．Ｔｈｅｐｒｅｄｉｃｔｉｏｎｏｆｔｈｅｐｈａ...     

航天电子产品中SMT焊点形态对其疲劳寿命的影响

深入分析了航天电子产品中表面组装技术(surface mount technology,简称SMT)焊点可靠性影响因素及失效机理,研究了温度循环下SMT焊点弹塑性应力应变规律及其寿命预测方法,并在此基础上探索了元件与焊盘间隙、钎料量、外轮廓等形态对焊点热疲劳寿命的影响,揭示焊点形态与应力应变和疲劳寿命之间的对应关系,以寻求具有较为理想力学性能及热循环寿命的焊点形态. 结果表明,上述理论方法为实际焊接过程中的PCB上焊盘尺寸的合理设计提供了理论支撑.     

Influences of fine pitch solder joint shape parameters on fatigue life under thermal cycle

1 INTRODUCTION The electronicer industry is driven mainly by the demand for“smaller ,faster ,higher complexi- ty ,lower power consumption and cheaper”[1]. To meet these needs , the demand for smaller size , higher density and higher heat dissipationintegrat- ed circuit (IC) chips is on the rise . With the requirements of high performance and small pack- age size ,the design of IC chips is headed toward higher pin count ,smaller pad size and fine pitch; consequently ,the fine pitch tech…     

3D封装微尺度CSP焊点随机振动应力应变分析

基于ANSYS软件建立了3D芯片尺寸封装有限元模型,对模型中微尺度CSP焊点在随机振动载荷条件下进行有限元分析,获得了CSP焊点应力应变分布情况;分析了不同焊点材料、焊盘直径和焊点体积对应力应变的影响;并以焊点体积、焊点高度、焊盘直径为设计参数,以随机振动条件下CSP焊点应力值作为目标值,设计17组试验仿真计算,采用响应曲面法对17组应力值与微尺度CSP焊点形态参数间关系进行拟合,结合遗传算法对拟合函数进行优化.结果表明,随机振动环境下应力值最小的CSP焊点组合参数为焊点最大径向尺寸0.093 mm、焊点高度0.077 mm、焊盘半径0.068 mm,并对最优组合参数仿真验证,最优组合仿真结果优于17组试验仿真结果,实现了随机振动环境下微尺度CSP焊点的结构优化.     

Ag—Pb和Ni对元铅钎料焊点形状、微结构及剪切强度的影响

研究了器件端头两种不同的金属化层（Ag-Pd和Ni/Ag-Pd）对Sn-Sb钎料表面粘装焊点的形状、微结构及剪切强度的影响,并与常用的Sn-Pb-Ag钎料焊点进行了比较,结果表明：Sn-Sb/Ag-Pd焊点由于Sn-Sb钎料与Ag-Pd／陶瓷界面;Sn-Sb/Ni/Ag-Pd焊点中Ni有效地阻止了Ag-Pd在钎料中的溶解,焊点形状理想,强度很高;而对于Sn-Pb-Ag钎料、器件金属化层对焊点形状和强度影响不大,剪切测试后,断裂发生在钎料内部。     

面向完整传输路径的BGA焊点信号完整性分析及优化

建立了基于BGA(ball grid array)焊点的完整传输路径的HFSS(high frequency simulator structure)电磁仿真模型,基于该模型对完整传输路径在高频条件下的信号完整性问题进行了分析,得到了其回波损耗仿真结果,以及焊点最大径向尺寸、焊点高度尺寸、焊盘直径尺寸对回波损耗的影响. 并以焊点最大径向尺寸、焊点高度尺寸、焊盘直径尺寸为设计参数,以完整传输路径6 GHz下的回波损耗作为目标值,设计17组试验仿真计算,采用响应曲面法对仿真计算所得的17组完整传输路径回波损耗与BGA焊点形态参数间关系进行拟合,结合遗传算法对拟合函数进行优化,得到完整传输路径回波损耗最小的BGA焊点组合参数为焊点最大径向尺寸1.05 mm,焊点高度0.75 mm,焊盘直径0.65 mm,并对最优组合参数仿真验证,最优组合仿真结果优于17组试验仿真结果,实现了完整传输路径中BGA焊点的结构优化.     

基于焊点形态预测与塑性应变计算的工艺参数对QFP焊点可靠性影响分析

选取焊盘长度、焊盘宽度、钢网厚度和间隙高度4个工艺参数作为关键因素,采用水平正交表L25(56)设计了25种不同参数组合的208脚、0.5mm引脚间距四方扁平封装(Quad Flat Package:QFP)器件焊点;建立了这25种焊点的三维形态预测模型和三维有限元分析模型;对热循环加载条件下QFP焊点进行了非线性有限元分析,基于塑性应变采用Coffin-Manson方程计算了25种不同焊点形态的QFP焊点热疲劳寿命;针对热疲劳寿命计算结果,进行了极差分析与方差分析。结果表明,最优的工艺参数组合为焊盘长度1.25mm,焊盘宽度0.30mm,钢网厚度0.125mm,间隙高度0.05mm;在置信度为90%的情况下,焊盘长度对QFP焊点可靠性具有显著影响而焊盘宽度、钢网厚度、间隙高度对可靠性无显著影响。     

基于正交设计的WLCSP柔性无铅焊点随机激励应力应变分析

对晶圆级芯片尺寸封装(wafer level chip scale package, WLCSP)柔性无铅焊点进行了随机振动应力应变有限元分析. 以1号柔性层厚度、2号柔性层厚度、上焊盘直径和下焊盘直径四个结构参数作为关键因素,采用正交表设计了16种不同结构参数组合的柔性焊点,获取了16组应力数据并进行了方差分析. 结果表明:焊点内最大应力应变随1号柔性层厚度和2号柔性层厚度的增加而减小;在置信度99%时,下焊盘直径和上焊盘直径对应力具有高度显著影响,在置信度95%时1号柔性层厚度和2号柔性层厚度对应力具有显著影响;各因素对应力影响排序为:下焊盘直径影响最大,其次是上焊盘直径,再次是1号柔性层厚度,最后是2号柔性层厚度.     

SMT焊点间隙和贴片误差自调整作用分析

采用表面组装ＳｎＰｂ焊点形态的势能控制方程,对片式元件ＲＣ３２１６的三维焊点形态了数值模拟。基于焊点体系的势能数据,分析了片式元件的焊点间隙和贴片误差的自调整作用。结果表明,焊点间隙随焊点钎料量的增加而近似线性增加;焊点间隙和粘点钎料量的增加有助于贴片误差的自调整作用,并提出了焊点间隙的一种回归模型。     

矩形片状元件无铅焊点断裂机制

采用微焊点强度测试仪测试了Sn-Ag-Cu钎料和Sn-Pb钎料钎焊的矩形片状元件钎焊接头的抗剪强度,并对焊点断口进行了扫描电镜分析.结果表明,Sn-Ag-Cu无铅钎料焊点的抗剪力明显大于Sn-Pb钎料焊点的抗剪力,但是两种焊点的剪切力变化曲线相似,表明焊点在剪切失效前都有明显的塑性应变过程.断口SEM分析发现,两种焊点的断裂位置都位于钎料与元件底面焊盘的界面处和钎料与元件侧面焊盘的界面处,且Sn-Ag-Cu钎料焊点的性能都比Sn-Pb钎料焊点的性能优异,说明Sn-Ag-Cu钎料完全可以替代Sn-Pb钎料钎焊矩形片状元件.     

Study on solder joint reliability of ceramic ball grid array component based on design of experiment method

Four process parameters, pad diameter, stencil thickness, ball diameter and stand-off were chosen as four control factors. By using an L25 （5^6 ） orthogonal array the ceramic ball grid array （ CBGA ） solder joints which have 25 different combinations of process parameters were designed. The numerical models of all the 25 CBGA solder joints were developed using the Sugrace Evolver. Utilizing the sugrace coordinate exported from the 25 CBGA solder joints numerical models, the finite element analysis models were set up and the nonlinear finite element analysis of the CBGA solder joints under thermal cycles were pegrormed by ANSYS. The thermal fatigue life of CBGA solder joint was calculated using Coffin-Manson equation. Based on the calculated thermal fatigue life results, the range analysis and the variance analysis were pegrormed. The results show that the fatigue life of CBGA solder joint is affected by the pad diameter, the stencil thickness, the ball diameter and the stand-off in a descending order, the best combination of process parameters results in the longest fatigue life is 0.07 mm stand-off, 0.125 mm stencil thickness of, 0.85 mm ball diameter and 0. 89 mm pad diameter. With 95% confidence the pad diameter has a significant effect on the reliability of CBGA solder joints whereas the stand-off, the stencil thickness and the ball diameter have little effect on the reliability of CBGA solder joints.