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.     

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.     

应力对SnPb基复合钎料钎焊接头蠕变性能的影响

采用搭接面积为1mm^2的单搭接钎焊接头，研究了恒定温度下，应力对纳米颗粒增强的SnPb基复合钎料钎焊接头的蠕变寿命的影响。结果表明，纳米颗粒增强的SnPb基复合钎料的蠕变抗力优于传统SnPb钎料。同时钎焊接头的蠕变寿命随应力增加而降低，且应力对复合钎料钎焊接头蠕变寿命的影响较传统63Sn37Pb钎料明显。     

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.     

Sn-9Zn无铅钎料合金的压蠕变行为研究

试验研究了Sn-9Zn合金钎料在温度为40～100℃和压力为9．3～18．6MPa范围内的压蠕变行为。结果表明：随温度和应力的升高，合金的压蠕变量增大，稳态蠕变速率的对数分别与应力对数和温度呈较好的线性关系，稳态蠕变速率符合半经验公式。在不同的温度下，应力指数n相近，平均值为5．74；不同的应力下，表观激活能Qa相差不大，平均值为51．95kJ／mol，材料结构常数为0．03，压蠕变变形是位错滑移和位错攀移共同作用的结果，控制稳态蠕变速率的主要因素为位错管道扩散过程控制下的位错攀移。     

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     

基于小冲杆试验的固体氧化物燃料电池钎焊密封接头蠕变损伤演化规律

如何获得钎焊接头三明治微结构的蠕变力学性能一直以来是一个难题. 文中基于Wen-Tu蠕变延性耗竭模型开发了钎焊接头蠕变损伤子程序,利用ABAQUS有限元软件建立了与SOFC密封接头相类似的钎焊接头小冲杆模型;采用试验与有限元相结合的方法研究了以304不锈钢为母材的SOFC钎焊接头蠕变损伤特性,得到了不同载荷下钎焊接头试样中心蠕变挠度变化率和蠕变应变变化率之间关系,阐明了钎焊接头在小冲杆蠕变试验条件下的蠕变损伤及裂纹扩展规律. 结果表明,适当的增加钎料的厚度有利于提高钎焊接头的抗蠕变变形能力,延长高温蠕变断裂寿命,且钎焊接头在多轴应力作用下主要断裂方式为脆性断裂. 初始裂纹最早在母材下表面萌生,距试样中心0.85 mm处,随后向上扩展至钎料层下表面,然后在钎料层上表面出现裂纹逐渐向母材上表面与钎料层下表面扩展,直至断裂.     

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。     

6061铝合金与可伐合金钎焊接头残余应力分析

为探究钎焊接头中残余应力分布问题,选用Au80Sn20/Sn63Pb37两种共晶钎料分别钎焊6061铝合金/4J34可伐合金基板,形成钎焊接头进行试验。选取不同的钎焊工艺参数(钎焊温度、钎焊时间等),以研究钎焊工艺对钎缝残余应力分布的影响规律,并进一步对残余应力进行数值模拟和研究。结果表明,残余应力均为拉应力,且靠近可伐合金侧钎缝的残余应力更高,钎焊接头在可伐合金侧钎缝更容易出现断裂;对于Au80Sn20钎料,在相同钎焊温度下,随着钎焊时间的增加,铝合金侧钎缝处的残余应力会略有增大;对于Sn63Pb37钎料,不同的钎焊温度和钎焊时间对数值结果影响不大。X射线残余应力实测结果与计算值的一致性良好,证明了模拟计算结果的正确性,为研究电子产品中轻质合金钎焊接头的可靠性提供了一种有效方法。     

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.     

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.     

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…     

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.     

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.     

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.     

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。