Effects of Current Stressing and Isothermal Aging on the Tensile Strength of Microscale Lead-Free Solder Joints with Different Joint Volumes

2013 ◽  
Vol 634-638 ◽  
pp. 2800-2803 ◽  
Author(s):  
Li Meng Yin ◽  
Yan Fei Geng ◽  
Zhang Liang Xu ◽  
Song Wei

Adopting an accurate micro-tensile method based on dynamic mechanical analyzer (DMA) instrument, the tensile strength of three kinds of copper-wire/solder/copper-wire sandwich structured microscale lead-free solder joints that underwent current stressing with a direct current density of 1.0×104 A/cm2 and loading time of 48 hours were investigated, and compared with those solder joints isothermal aged at 100 0C for 48 hours and as-reflowed condition. These three kinds of microscale columnar solder joints have different volumes, i.e., a same diameter of 300 μm but different heights of 100 μm, 200 μm and 300 μm. Experimental results show that both current stressing and isothermal aging degrades the tensile strength of microscale solder joints, and the solder joint with smaller volume obtains higher tensile strength under same test condition. In addition, current stressing induces obvious electromigration (EM) issue under high current density of 1.0×104 A/cm2, resulting in the decreasing of tensile strength and different fracture position, mode and surface morphology of microscale solder joints. The degree of strength degradation increases with the increasing of joint height when keep joint diameter constant, this is mainly due to that electromigration leads to voids form and grow at the interface of cathode, and solder joints with larger volume may contains more soldering defects as well.

2018 ◽  
Vol 30 (2) ◽  
pp. 74-80 ◽  
Author(s):  
Attila Geczy ◽  
Daniel Straubinger ◽  
Andras Kovacs ◽  
Oliver Krammer ◽  
Pavel Mach ◽  
...  

2007 ◽  
Vol 345-346 ◽  
pp. 1403-1410
Author(s):  
Cemal Basaran

In this paper, Moiré interferometry technique is used to measure the in-situ displacement evolution of lead-free solder joints under high density (104A/cm2). An electromigration constitutive model is developed to simulate deformation of lead-free solder joint under current stressing. The simulation predicts Moiré interferometry measurements in both spatial distribution and time history evolution, which indicates that the model is reasonably good for predicting the mechanical behavior of lead-free solder joints under electric current stressing.


Author(s):  
Abdullah Fahim ◽  
Sudan Ahmed ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall

Exposure of lead free solder joints to high temperature isothermal aging conditions leads to microstructure evolution, which mainly includes coarsening of the intermetallic (IMC) phases. In our previous work, it was found that the coarsening of IMCs led to degradation of the overall mechanical properties of the SAC solder composite consisting of β-Sn matrix and IMC particles. However, it is not known whether the isothermal aging changes properties of the individual β-Sn and IMC phases, which could also be affecting to the overall degradation of properties. In this study, the aging induced variations of the mechanical properties of the β-Sn phase, and of Sn-Cu IMC particles in SAC solder joints have been explored using nanoindentation. SAC solder joints extracted from SuperBGA (SBGA) packages were aged for different time intervals (0, 1, 5, 10 days) at T = 125 °C. Nanoindentation test samples were prepared by cross sectioning the solder joints, and then molding them in epoxy and polishing them to prepare the joint surfaces for nanoindentation. Multiple β-Sn grains were identified in joints using optical polarized microscopy and IMCs were also observed. Individual β-Sn grains and IMC particles were then indented at room temperature to measure their mechanical properties (elastic modulus and hardness) and time dependent creep deformations. Properties measured at different aging time were then compared to explore aging induced degradations of the individual phases. The properties of the individual phases did not show significant degradation. Thus, IMC coarsening is the primary reason for the degradation of bulk solder joint properties, and changes of the properties of the individual phases making up the lead free solder material are negligible.


2021 ◽  
pp. 114201 ◽  
Author(s):  
Pierre Roumanille ◽  
Emna Ben Romdhane ◽  
Samuel Pin ◽  
Patrick Nguyen ◽  
Jean-Yves Delétage ◽  
...  

Author(s):  
Hongtao Ma ◽  
Tae-Kyu Lee ◽  
Dong Hyun Kim ◽  
H G Park ◽  
Sang Ha Kim ◽  
...  

2010 ◽  
Vol 650 ◽  
pp. 91-96 ◽  
Author(s):  
Ke Ke Zhang ◽  
Yao Li Wang ◽  
Yan Li Fan ◽  
Guo Ji Zhao ◽  
Yan Fu Yan ◽  
...  

The effects of Ni on the properties of the Sn-2.5Ag-0.7Cu-0.1Re solder alloy and its creep properties of solder joints are researched. The results show that with adding 0.05wt% Ni in the Sn-2.5Ag-0.7Cu-0.1Re solder alloy, the elongation can be sharply improved without decreasing its tensile strength and it is 1.4 times higher than that of the commercial Sn-3.8Ag-0.7Cu solder alloy. Accordingly the creep rupture life of Sn-2.5Ag-0.7Cu-0.1Re-0.05Ni solder joints is the longest, which is 13.3 times longer than that of Sn-2.5Ag-0.7Cu-0.1Re and is also longer than that of the commercial Sn-3.8Ag-0.7Cu solder alloy. In the same environmental conditions, the creep rupture life of Sn-2.5Ag-0.7Cu-0.1Re-0.05Ni solder joints can sharply decrease with increasing the temperature and stress.


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