纳米Ag颗粒增强复合钎料蠕变性能的研究

制备纳米Ag颗粒增强的Sn-Cu基复合钎料.研究不同温度载荷下复合钎料钎焊接头的蠕变断裂寿命,并与Sn-0.7Cu基体钎料钎焊接头进行对比.此外,确定纳米Ag颗粒增强的Sn-Cu基复合钎料钎焊接头在不同温度和应力水平下的应力指数和蠕变激活能,建立复合钎料钎焊接头的稳态蠕变本构方程.结果表明,在不同的温度和应力下,与Sn-0.7Cu钎料钎焊接头相比,纳米Ag颗粒增强的Sn-Cu基复合钎料钎焊接头的蠕变断裂寿命均有所提高,且具有更高的蠕变激活能,说明复合钎料钎焊接头具有更优的抗蠕变性能.     

纳米银颗粒增强复合钎料的研究

研究了纳米银颗粒增强锡铅基复合钎料的物理性能、工艺性能、力学性能和蠕变性能。通过在Sn-37Pb中加入不同含量的纳米银颗粒，测定比较复合钎料的性能，从而选择最佳加入量。结果表明，φ(Ag)=3％的纳米银颗粒的复合钎料综合性能最好，与Sn-37Pb共晶钎料相比，所加入的纳米银颗粒对住错起到了钉扎作用，从而提高了钎焊接头的蠕变寿命，其断裂形貌特征为延性和脆性混合断裂。     

微连接用碳基纳米颗粒增强无铅复合钎料的研究新进展

综合评述含碳纳米管、石墨烯纳米片等碳基纳米颗粒增强微连接用无铅复合钎料的研究现状,介绍了碳纳米管、石墨烯纳米片、富勒烯、金属改性碳纳米管(石墨烯纳米片)等增强相对无铅钎料和钎焊接头组织与性能的影响。简述了无铅复合钎料的制备方法、熔化特性、导电性、润湿性、力学性能和无铅复合钎料焊点可靠性等,指出了碳基纳米颗粒增强无铅复合钎料存在的问题、解决措施及发展趋势。     

钎焊及其设备

块体Mg65Cu22Ni3Y19非晶态合金的制备及在焊接中的应用;温度对Cu颗粒增强SnPb基复合钎料钎焊接头蠕变性能影响；高温钎焊搭接接头中缺陷容许度（一）；АМц合金半成品的冶金遗传性对其钎焊性的影响；液晶显示器的无熔剂钎焊；TIG电弧钎焊钎料液滴内部流场数值模拟及分析。     

63Sn37Pb钎焊接头稳态蠕变本构方程的建立

采用高温蠕变测试装置，以简化的Dorn公式为基础．对63Sn37Pb微型单搭接钎焊接头蠕变应变进行了测试．确定了应力指数、蠕变激活能以及相关常数。建立了63Snd7Pb钎焊接头稳态蠕变本构方程，描述了稳态蠕变速率与应力和温度相关性。结果表明，钎焊接头应力指数和激活能均低于钎料本身的应力指数和激活能．说明钎料本身蠕变行为并不能完全代表钎焊接头的蠕变行为。     

Ag和Ni颗粒对63Sn37Pb力学性能和润湿性能的影响

锡铅钎料在电子工业中广泛应用。锡铅共晶或近共晶钎料熔点较低，钎焊工艺性能好，但抗蠕变性能差。作者运用弥散强化原理，分别选用1μm的Ag颗粒和Ni颗粒作为增强体，以63Sn37Pb为基体，制成金属颗粒增强的锡铅基复合钎料。在再流焊条件下，弥散分布的增强体与基体冶金结合，在增强体的表层形成-薄层金属间化合物，蠕变性能大幅度提高。试验证明，在相同条件下，与基体钎料63Sn37Pb相比，铺展面积略微下降，但Ag颗粒体积百分数为5％和10％的颗粒增强的锡铅基复合钎料的蠕变寿命分别提高8倍和6倍，同时抗拉强度和剪切强度均得到提高；Ni颗粒增强的复合钎料的蠕变寿命大幅度提高，Ni颗粒体积百分数为5％和10％的颗粒增强的锡铅基复合钎料的蠕变寿命分别提高了85倍和186倍，但润湿性能、剪切强度和延伸率均明显降低。     

工艺条件对颗粒增强复合钎料组织性能的影响

选用微米级Cu、Ni颗粒作为增强相外加到Sn-3.5Ag共晶基体钎料中制成颗粒增强Sn-Ag基复合钎料。主要利用电子显微镜研究不同工艺条件下,复合钎料钎焊接头内部增强颗粒周围金属间化合物(IMCs)形貌的演变情况,并分析了增强颗粒形态变化对复合钎料钎焊接头力学性能的影响。结果表明,随着升温速率的降低,Ni增强颗粒周围金属间化合物的形态由向日葵状转变为多边形状;Cu增强颗粒周围金属间化合物的形态始终保持大瓣向日葵状。此外,降温速率对Cu、Ni颗粒周围金属间化合物的形态没有影响。从而分析了不同工艺条件下增强颗粒周围金属间化合物形态的演变规律,以及对复合钎料钎焊接头剪切强度的影响。     

SnCu钎焊接头稳态蠕变本构方程建立

以搭接面积为1 mm2微型单搭接钎焊接头为研究对象,采用新型高温蠕变测试装置,测定了Sncu钎焊接头应力指数n和蠕变激活能Q,构建了稳态蠕变本构方程,探讨了蠕变变形机制.结果表明,在低温高应力下,SnCu共晶钎料钎焊接头应力指数为8.73,激活能在59.1～63.2 kJ/mol,位错攀移运动主要受位错管道扩散机制控制;在高温低应力区,Sncu共晶钎料钎焊接头应力指数为6.45,激活能在88.4～97.5 kJ/mol,位错攀移运动主要由晶格自扩散机制控制.     

钎焊及其设备

Ag-Cu-Ti钎料钎焊金刚石的界面微观组织分析;SnCu钎焊接头稳态蠕变本构方程建立;Cu颗粒增强复合钎料钎焊接头的蠕变断裂及强化机理;Pd-Co-Ni-V钎料钎焊SiC陶瓷的接头组织及性能;SiCp／Cu复合材料的真空钎焊     

钎焊及其设备

Ag-Cu-Ti钎料钎焊金刚石的界面微观组织分析;SnCu钎焊接头稳态蠕变本构方程建立;Cu颗粒增强复合钎料钎焊接头的蠕变断裂及强化机理;Pd-Co-Ni-V钎料钎焊SiC陶瓷的接头组织及性能;SiCp／Cu复合材料的真空钎焊     

The influence of temperature on creep behavior of Cu particle enhanced SnPb based composite soldered joints

Creep property of solder alloys is one of the important factors to affect the reliability of soldered joints in SMT(surface mount technology). Particle-enhancement is a way to improve the properties of solder alloys and has caused much more attention than before. Temperatures applied to soldered joints are one of the primary factors of affecting creep properties of particle enhancement composite soldered joints. In this paper single shear lap creep specimens with a 1 mm2 cross-sectional area were fabricated using Cu particle enhancement 63Sn37Pb based composite soldered joints and 63Sn37Pb eutectic soldered joints to examine the influence of temperature on creep behavior of soldered joints. Results indicated that the creep resistance of soldered joints of Cu particle enhancement 63Sn37Pb based composite soldered joint was generally superior to that of the conventional 63Sn37Pb soldered joint. At the same time, creep rupture life of the composite soldered joint was declined with increasing temperature and drop faster than that of the conventional 63Sn37Pb eutectic soldered joint.     

Influence of stress on the creep behavior of Cu particle enhancement SnPb based composite solder joints

1. Introduction Mechanical fracture of solder joints is a major cause of failure and it decreases the reliability in electronic systems. With the increased functionality, miniaturization of electronic components, broad op-eration temperature ranges, and increased stress re-quirement, good mechanical properties are de-manded on solder joints. The eutectic tin-lead solder, which has a low melting point (183°C), plays an important role in SMT (surface mount technology). The working temperature…     

CuCGA器件焊点热疲劳行为数值模拟

基于蠕变模型构建 Sn3.9Ag0.6Cu 和 63Sn37Pb 钎料的本构方程,分析铜柱栅阵列封装(CuCGA)器件在不同温度循环载荷下焊点的应力-应变分布.结果表明,不论温度循环如何变化,距器件中心最远处焊点的等效蠕变值总是最大,且均有明显的应力集中现象,在热循环作用下,很容易在该焊点处最先产生裂纹,导致器件失效,是整个器件最脆弱的焊点.同样温度载荷下,Sn3.9Ag0.6Cu 焊点的应力应变总是小于 63Sn37Pb 焊点,而随着温度循环范围的减小,两种钎料的应力和蠕变值均有所降低.另外,预测发现同样温度循环载荷条件下 Sn3.9Ag0.6Cu 焊点具有较高的疲劳寿命.

Abstract：

The constitutive equation of Sn3. 9Ag0.6Cu and 63Sn37Pb were established based on creep law, and the stress-strain distribution of soldered joints in copper column grid array (CuCGA)devices was analyzed under the loadings of different temperature cycles. Results indicate that no matter how the change of temperature cycle range, the maximum creep strain is located in the soldered joint where the location from the device center is foremost, in which the stress concentration is found and cracks appear, therefore, the comer soldered joint is the most fragile area in the whole device.Creep strain of Sn3.9Ag0. 6Cu soldered joints is smaller than that of 63Sn37Pb soldered joints. Low er stress and creep strain are exhibited for both Sn3.9Ag0.6Cu and 63Sn37Pb when the temperature cycles range is shortened. Sn3.9Ag0.6Cu soldered joints show higher thermal fatigue life than 63Sn37Pb soldered joints under the same temperature cycle.     

不同钎料对QFP焊点可靠性影响的有限元分析

采用有限元方法研究了不同钎料钎焊QFP器件焊点的可靠性.结果表明,焊点根部、焊趾部位以及引线和焊点交界处为应变集中区域.分析探讨了Sn3.8Ag0.7Cu,Sn9Zn,Sn63Pb37三种钎料的模拟结果,焊点的应变曲线图显示,Sn63Pb37钎料焊点的等效应变最大,Sn9Zn钎料居中,Sn3.8Ag0.7Cu焊点的等效应变最小,表明Sn3.8Ag0.7Cu替代Sn63Pb37作为微元器件组装的组装材料具有更好的焊点力学性能.通过分析QFP64和QFP208两种器件焊点应力曲线图可以看出,QFP208器件焊点的应力值小于QFP64器件焊点的应力值,从而具有更高的可靠性.     

半导体激光工艺参数对Sn-Ag-Cu钎料润湿性影响分析

采用半导体激光软钎焊系统对Sn96Ag3．5Cu0．5钎料和Sn63Ph37钎料进行了润湿性对比试验研究，分析了激光输出功率对钎料润湿性的影响规律。结果表明，提高半导体激光的输出功率，在一定范围内能显著改善Sn96Ag3．5Cu0．5钎料和Sn63Ph37钎料的润湿性。根据钎料的合金成分及钎料膏中钎剂成分的不同，优化半导体激光钎焊工艺参数，可以达到最佳的钎焊效果。     

Numerical simulation of soldered joints and reliability analysis of PLCC components with J-shape leads

This paper deals with a study on SnPb and lead-free soldered joint reliability of PLCC devices with different lead counts under three kinds of temperature cycle profiles, which is based on non-linear finite element method. By analyzing the stress of soldered joints, it is found that the largest stress is at the area between the soldered joints and the leads, and analysis results indicate that the yon Mises stress at the location slightly increases with the increase of lead counts. For PLCC with 84 leads the soldered joints was modeled for three typical loading （273 -398 K, 218 -398 K and 198 -398 K） in order to study the influence of acceleration factors on the reliability of soldered joints. And the estimation of equivalent plastic strain of three different lead-free solder alloys （ Sn3.8AG0. 7Cu, Sn3.5Ag and Sn37Pb ） was also carried out.     

两种无铅钎料的抗蠕变性能与Sn60Pb40钎料的对比分析

对两种无铅钎料Sn-Ag-Cu-Bi和Sn-Ag-Sb模拟封装钎焊接头的蠕变和断裂行为进行了研究,并与传统的Sn60Pb40近共晶钎料进行了对比.结果表明,两种无铅钎料的抗蠕变能力均远优于Sn60Pb40近共晶钎料,其蠕变速率低且蠕变寿命长.钎焊接头蠕变断裂后的扫描电镜分析表明,两种无铅钎料钎焊接头的蠕变断裂呈现明显的沿晶断裂特征,而Sn60Pb40钎料钎焊接头的蠕变断裂机理则为穿晶断裂.     

片式电容Sn96.5/Ag3/Cu0.5焊点热疲劳性能比较

以0805封装片式电容器件焊点为研究对象,建立了多周期温度冲击下Sn96.5/Ag3/Cu0.5的焊点有限元分析模型,开展了多周期温度冲击条件下焊点剪切力测试工作,获得了Sn96.5/Ag3/Cu0.5和Sn63/Pb37两种焊点的周期-剪切力测试数据,并利用非线性最小二乘法得到了1 500个周期内的焊点热疲劳状态拟合曲线.结果表明,在规定试验条件下,在有限的1 500个周期内0805封装电容的Sn96.5/Ag3/Cu0.5焊点的热疲劳劣化速率略慢于Sn63/Pb37焊点.     

底充胶叠层PBGA无铅焊点随机振动应力应变分析

建立了底充胶叠层塑料球栅阵列(plastic ball grid array, PBGA)无铅焊点三维有限元分析模型,研究了PBGA结构方式、焊点材料、底充胶弹性模量和密度对叠层无铅焊点随机振动应力应变的影响. 结果表明,底充胶可有效降低焊点内的随机振动应力应变;在其它条件相同下,对于Sn95.5Ag3.8Cu0.7,Sn96.5Ag3Cu0.5,Sn-3.5Ag和Sn63Pb37这四种焊料,采用Sn-3.5Ag的底充胶叠层焊点内的随机振动最大应力应变最小,采用Sn96.5Ag3Cu0.5的焊点内的最大应力应变最大;随着底充胶弹性模量的增大,叠层无铅内的随机振动应力应变值相应减小;随着底充胶密度的增大,叠层无铅内的随机振动应力应变值相应增大.