铝/铜复合界面金属间化合物

冷轧复合板轧制后要进行一定的热处理以加强界面的结合强度,但同时也带来一定的问题如在界面形成不利于界面结合的化合物.本文对冷轧制备的铝/铜层状双金属片进行了研究,得到了不同退火温度和退火时间下扩散热处理后界面金属间化合物相的生长规律,初步建立了金属间化合物形成的动力学模型.     

Sn-Ag-xCu-Bi-Ni/Cu焊点界面IMC演变

为了研究低银无铅焊点界面金属间化合物(IMC)的形成与演变,以低银无铅焊点Sn-Ag-xCu-Bi-Ni/Cu为研究对象,研究了钎料中Cu质量分数对界面IMC厚度、形貌和成分的影响.实验结果表明,随着钎料中Cu质量分数的增加,回流焊后焊点IMC层厚度变薄,IMC晶粒尺寸增大,IMC晶粒形貌由颗粒状转变为棱柱状以及鹅卵石状,同时界面IMC成分发生由(Cu,Ni)6Sn5向Cu6Sn5的转变.高温时效后,界面IMC层厚度增长.当钎料中Cu质量分数超过1%时,时效后生成较厚的Cu3Sn化合物层,对焊点可靠性不利.钎料中Cu质量分数应控制在1%以下.     

铝/钢异种金属焊接接头界面Al-Fe金属间化合物生成及其热力学分析

对铝/钢异种金属焊接接头界面进行了XRD和EDS分析,结果表明:在Al-Fe界面上主要生成Fe2Al5和FeAl3两种金属间化合物,以热力学基本定律为基础,建立了基于相图的Al-Fe金属间化合物形成的吉布斯自由能计算模型,利用该模型分别计算了各Al-Fe金属间化合物形成的吉布斯自由能随温度变化的关系。结果表明,生成Fe2Al5的吉布斯标准自由能比生成FeAl3的低,所以在铝/镀锌钢板的焊接过程中,Fe2Al5要比FeAl3优先生成。     

金属间化合物/陶瓷复合材料的制备技术

简要介绍了金属间化合物／陶瓷复合材料的制备方法、基本原理以及发展现状，并对其未来的发展方向作了展望。     

NiAl金属间化合物改性研究

采用自反应高温合成技术及粉末冶金工艺制备了ＮｉＡｌ金属间化合物及其合金。通过三点弯曲和常温压缩实验法研究了ＮｉＡｌ金属间化合物及其改性后材料的常温性能。结果表明：合金元素硼明显提高了ＮｉＡｌ材料的常温强度但塑性改善不大；合金元素铁使ＮｉＡｌ材料的常温变形能力有一定的改善。采用自洽物离散文分Ｘα方法对合金化前后材料的键性进行计算，并由此来说明化学键的变化对材料性能的影响。     

金属间化合物NiAl的研究进展

介绍在NiAl金属间化合物方面取得的研究成果。主要成果有：NiAl合金超塑性及其机理研究；NiAl合金韧脆转变及其机理；纳米晶NiAl合金及其复合材料；内生颗粒增强NiAl基复合材料及强韧化机制；合金元素的作用以及JJ-3合金的发展。     

NiAl金属间化合物改性研究

采用自反应高温合成技术及粉末冶金工艺制备了ＮｉＡｌ金属间化合物及其合金。通过三点弯曲和常温压缩实验法研究了ＮｉＡｌ金属间化合物及其改性后材料的常温性能。结果表明：合金元素硼明显提高了ＮｉＡｌ材料的常温强度但塑性改善不大；合金元素铁使ＮｉＡｌ材料的常温变形能力有一定的改善。采用自洽物离散变分Ｘａ方法对合金化前后材料的键性进行计算，并由此来说明化学键的变化对材料性能的影响。     

Ni-Al系金属/金属间化合物层状复合材料的扩散制备研究

根据层状材料结构的仿生设计,利用层间原位反应扩散的方法,将两种不同金属箔片交替叠层到一起,在真空高温条件下保温,反应生成原位层状金属间化合物和残存的金属,制备出金属/金属间化合物层状复合材料．试验研究表明,通过控制反应扩散的温度和时间,可以制备出不同组分及体积分数的层状复合材料．经过对材料的显微结构、力学性能、断裂方式的检测和分析表明,利用扩散反应法可以制备出具有较高强度和韧性的层状复合材料．     

铝/镀锌钢焊接接头金属间化合物热力学分析

针对Al/镀Zn钢板Pulsed DE-GMAW焊接接头界面区金属间化合物相的确定性研究,在热力学基本定律的基础上,建立铝/镀锌钢板异种金属焊接接头界面Fe-Al-Zn相形成的吉布斯自由能变化的计算模型,得到Al/镀Zn钢板异种金属焊接接头Fe_2Al_5Zn_(0.4)金属间化合物相形成的标准吉布斯自由能与温度的变化关系,分析界面Fe_2Al_5Zn_(0.4)金属间化合物存在的可能性,并与焊接试验结果进行对比分析。模拟结果表明:所建立的热力学模型是合理的,在界面上形成Fe_2Al_5Zn_(0.4)金属间化合物,与试验结果基本一致,并推论了Fe_2Al_5Zn_(0.4)是在Fe_2Al_5与FeAl_3形成后,由于Zn扩散进入Fe_2Al_5的晶体空位所得到的。     

NiAl金属间化合物的制备技术

综述了NiAl金属间化合物的制备技术，包括熔模铸造、单晶制备、定向凝固、热压和热等静压、热挤压、扩散结合、机械合金化和燃烧合成等，并分析了这些制备技术的研究现状、优缺点、存在的问题及可能的解决方法。     

Significant Inhibition of IMCs Growth between an Electroless Ni-W-P Metallization and SAC305 Solder During Soldering and Aging

The formation and growth behavior of intermetallic compound(IMC) layers after introducing an electroless Ni-W-P metallization into the Sn-3.0Ag-0.5Cu(SAC305) solder joint during soldering and aging were investigated. The soldering was performed at 250 ℃ for 10 min, followed by air cooling and aging treatment at 150 ℃ up to 15 days. The results show that the scallop-like Cu_6Sn_5 IMC layer and planar-like Cu_3Sn formed between solder and Cu substrate during soldering and aging. The Ni_3P and(Ni,Cu)_3Sn_4 compounds were formed between electroless Ni-W-P layer and solder, and Cu substrate was not damaged and kept a smooth interface. When the isothermal aging treatment was applied, the total thickness of IMCs which formed at the SAC305/Cu and SAC305/Ni-W-P/Cu interface increased with increasing aging time. Kirkendall voids emerged at the Cu_3Sn and the Ni_3P layers, but the voids emerged at the Ni_3P layer in the form of crack. The amount of Kirkendall voids increased and the crack elongated with increasing aging time. The Cu_6Sn_5 and(Ni,Cu)_3Sn_4grains grew by merging adjacent grains. In the process of growth, the growing interfacial compounds filled the free space, and new columnar dendrite grain of(Ni,Cu)_3Sn_4 constantly generated during aging treatment. After 15 days aging, the Ni-W-P barrier layer was still remained, which indicated that the Ni-W-P layer can be a good barrier layer between the solder alloys and Cu substrate.     

Interfacial IMC Growth and Nanomechanical Characterizations of Solder in Sn-16Sb/Cu Joints during Solid-state Aging

The effects of aging time and temperature on the formation and growth behavior of interfacial intermetallic compound(IMC) of Sn-16 Sb/Cu(wt%) solder joints prepared by using dip soldering were investigated. The results show that the major IMCs between Sn-16 Sb solder and Cu substrate after thermal aging are Cu3 Sn and Cu6 Sn5. The thickness of the interfacial IMC in Sn-16 Sb/Cu is linearly against the square root of aging time, which indicates that the growth of IMC is mainly controlled by diffusion between Cu and Sn atoms. By using linear regression method, the growth rate constants of interfacial IMC layers are 1.254×10~(-18), 8.821×10~(-18) and 1.22×10~(-17) m~2 s~(-1) for Sn-16 Sb/Cu joints aged at 120, 150 and 170 ℃, respectively. Besides, the activation energy of the interfacial IMC growth was also calculated to be 68.27 kJ/mol. The IMC grain diameters after aging treatment increase with the increasing aging time, with i e, d = 0.492 t~(0.106), d = 0.543 t~(0.143) and d = 0.290 t~(0.263) for aging temperatures of 120, 150 and 170 ℃, respectively. Besides, by using nanoindentation, the softening of Sn-16 Sb solder was found during aging treatment. Moreover, the U-shape evolution of the values in hardness and Young's moduli was found in this work.     

微电子封装中焊锡接点的界面应力奇异性

采用界面力学理论计算了不同形状的含铅/无铅焊锡接点界面应力奇异性指数,建立了焊锡接点的有限元模型,计算了线弹性、弹塑性和Johnson-cook材料模型的界面应力分布.结果表明:随着焊锡接点接触角的增加,界面应力奇异性增强;Sn37Pb/Cu界面比Sn3.5Ag/Cu和Sn3.0Ag0.5Cu/Cu界面的应力奇异性明显;弹塑性变形和应变率效应降低界面应力.     

CSP焊点焊后残余应力分析与预测

该文建立了芯片尺寸封装(CSP)焊点有限元分析模型并对其进行了再流焊焊后残余应力应变分析.以焊点直径、焊点高度、焊盘直径和焊点间距为输入参数,焊后残余应力为输出参数进行了灵敏度分析.选取灵敏度分析结果中对残余应力影响显著的因子作为输入,建立了带动量项神经网络预测模型,对CSP焊点焊后残余应力进行了预测.结果表明,置信度...     

不同Cu/Sn比与IMC-Cu复合微焊点形成速度的相关性

为了研究不同Cu/Sn比对复合微焊点IMC-Cu界面生长行为的影响,采用瞬态液相连接技术与热压焊相结合的方法,以泡沫铜、纯Sn和Cu基板为原料,制备IMC-Cu复合微焊点研究不同Cu/Sn比对复合微焊点IMC生长行为影响.结果表明:Cu/Sn比对复合焊点中IMC生长行为影响显著.随着焊点中Sn含量的减少,IMC的生长速...     

Influence of Bi Addition on Pure Sn Solder Joints: Interfacial Reaction,Growth Behavior and Thermal Behavior

The effects of different Bi contents on the properties of Sn solders were studied. The interfacial reaction and growth behavior of intermetallic compounds(IMCs) layer(η-Cu_6 Sn_5 + e-Cu_3 Sn) for various soldering time and the influence of Bi addition on the thermal behavior of Sn-x Bi solder alloys were investigated. The Cu_6 Sn_5 IMC could be observed as long as the molten solder contacted with the Cu substrate. However, with the longer welding time such as 60 and 300 s, the Cu_3 Sn IMC was formed at the interface between Cu_6 Sn_5 and Cu substrate. With the increase of soldering time, the thickness of total IMCs increased, meanwhile, the grain size of Cu_6 Sn_5 also increased. An appropriate amount of Bi element was beneficial for the growth of total IMCs,but excessive Bi(≥ 5 wt%) inhibited the growth of Cu_6 Sn_5 and Cu_3 Sn IMC in Sn-x Bi/Cu microelectronic interconnects. Furthermore, with the Bi contents increasing(Sn-10 Bi solder in this present investigation), some Bi particles accumulated at the interface between Cu_6 Sn_5 layer and the solder.     

板级电子封装跌落／冲击中焊点应力分析

建立了板级BGA封装跌落/冲击问题的三维有限元模型,采用Input-G方法对PCB板的变形及焊锡接点应力等动力学响应进行了分析,探讨了约束条件对计算结果的影响,对焊点剥离应力产生的机理进行了讨论,提出了快速估算焊点应力的等效静力学模型并分析了误差.结果表明,模型中PCB板固定螺栓处的约束条件处理对结果有较大影响,合理的处理方法是在PCB板4个螺栓作用区的上下表面均施加水平方向位移约束.焊点应力最大值出现在冲击后0.4 ms,最大剥离应力发生在角部焊点与PCB板一侧的铜垫交界处.焊点应力与PCB板的弯曲变形密切相关,应力峰值和PCB板的变形峰值在时间上具有同步性.挠度等效静力学模型得到的焊点应力比动力学模型高23%左右.     

电子封装中的无铅Sn-3.8Ag-0.5Cu/Cu界面研究

针对钎料与焊盘间形成IMC层的厚度是影响可靠性的一个关键因素．对无铅钎料Sn-3．8Ag-0．5Cu与Cu盘进行了重熔,采用Olympus（光学金相显微镜）,SEM（扫描电镜）和EDX（能谱X射线）界面分析手段,研究了合金Sn-3．8Ag-0．5Cu与Cu焊盘接头的钎焊性和在焊接过程中IMC的形成与长大机理,探讨了IMC厚度与保温时间的变化规律．研究结果表明,无铅钎料合金Sn-3．8Ag-0．5Cu在钎焊务件下与Cu焊盘能够实现良好的连接,其连接层为Cu6Sn5金属间化合物,重熔时的IMC层生长基本上符合抛物线规律．     

微电子封装中焊点的电迁移现象分析与研究

综述了当前对微电子封装中焊点的电迁移现象及其影响因素的研究现状,分析了电流密度、温度和合金成分对电迁移失效过程的影响,以及电迁移对焊点力学性能、疲劳强度和焊点断裂机制的影响.研究发现,电迁移显著降低焊点的力学性能,对微焊点平均拉伸强度的影响存在尺寸效应,明显地降低了微焊点的振动疲劳寿命,且电迁移使微焊点的断裂机制由塑性断裂转向脆性断裂.