Fatigue properties of lead-free solder joints in electronic packaging assembly investigated by isothermal cyclic shear fatigue

2014 ◽  
Author(s):  
Huili Xu ◽  
Tae-Kyu Lee ◽  
Choong-Un Kim
Keyword(s):  
Electronic Packaging ◽  
Solder Joints ◽  
Lead Free ◽  
Fatigue Properties ◽  
Lead Free Solder ◽  
Cyclic Shear ◽  
Shear Fatigue ◽  
Free Solder

Effect of Voids on Thermal Fatigue Reliability of Lead-Free Solder Joints

2002 ◽  
Author(s):  
Qiang Yu ◽  
Do-Seop Kim ◽  
Tadahiro Shibutani ◽  
Toshiaki Inoue ◽  
Nobuyuki Sadakata
Keyword(s):  
Fatigue Strength ◽  
Fatigue Test ◽  
Fatigue Fracture ◽  
Fracture Mode ◽  
Solder Joints ◽  
Equivalent Plastic Strain ◽  
Lead Free ◽  
Lead Free Solder ◽  
Shear Fatigue ◽  
Free Solder

There have been serious debates about whether Pb should be removed from solder joints, in view of environmental problems. These debates have now developed to the extent that a remarkable movement to establish regulations for the removal of Pb has emerged, especially in European countries and Japan. Therefore, many studies are aggressively being undertaken to develop technologies for replacing Sn-Pb solder with a lead-free alternative. From the results obtained so far, it has been proven that the fatigue strength in lead-free solder joints is almost equivalent to the fatigue strength of Sn-Pb eutectic solder joints. However, the other problem is that voids are easily formed in lead-free solder joints during the reflow process, and the effects of void formation on the fatigue strength of solder joints has attracted attention. In this study, the relationship between formation of voids and fatigue fracture mode and fatigue strength of solder joints was examined using FEM (finite element method) analysis and mechanical shear fatigue test. From the results of FEM analysis, it has been found that the equivalent plastic strain and shear strain of solder joints with voids are not always larger than those of solder joints without voids and the magnitude of the strains relate to the position and size of voids in solder joints. However, the difference of the strains is not so great as to affect the fatigue strength of solder joints. It has also been proven from the mechanical shear fatigue test that the fatigue fracture mode of solder joints with voids is similar to that of solder joints without voids and fatigue strength in both cases is also almost equivalent.

Effects of Shear Cycling on the Mechanical Properties of SAC and SAC+X Lead Free Solder Joints

2019 ◽  
Author(s):  
Mohd Aminul Hoque ◽  
Md Mahmudur Chowdhury ◽  
Sa’d Hamasha ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Mechanical Properties ◽  
Solder Joints ◽  
Coefficient Of Thermal Expansion ◽  
Real Life ◽  
Material Behavior ◽  
Lead Free ◽  
Lead Free Solder ◽  
Cyclic Shear ◽  
Mechanical Cycling ◽  
Free Solder

Abstract Solder joint reliability is a chief concern in electronic assemblies. Electronic packages consist of various materials, each having their own Coefficient of Thermal Expansion (CTE). When assembled packages experience high temperature gradients and thermal cycles, a mismatch in the CTE values brings about cyclic shear strains in the solder joints, which can ultimately lead to failure. Thus, it is important to understand the effects of shear cycling on the damage accumulated in solder joints. Previous studies conducted on the effect of mechanical cycling on the material behavior of lead free solders have been performed on bulk samples subjected to tension and compression. Our goal in this study was to determine the evolution of the mechanical properties of doped lead free solder joints when subjected to mechanical shear cycling. Experiments conducted on actual solder joints would help us gain a better understanding on the real life effects of shear cycling. The test specimens consisted of a 3 × 3 array of nine solder joints of approximately 0.75 mm diameter. With the aid of specially designed test fixtures, the specimens were gripped and then subjected to mechanical cycling in the shear using an Instron Micromechanical tester. Testing was performed on both SAC305 and SACX (SAC+Bi) solder joints. The joints were cycled for certain durations, and a nanoindentation system was used to measure the evolution of the mechanical properties (elastic modulus, hardness, creep rate) as a function of the number of shear cycles.

Effect of Voids on Thermal Fatigue Reliability of Lead Free Solder Joint

2005 ◽  
Author(s):  
Doseop Kim ◽  
Qiang Yu ◽  
Yusuke Kobayashi ◽  
Tadahiro Shibutani
Keyword(s):  
Fatigue Strength ◽  
Fatigue Test ◽  
Solder Joints ◽  
Fatigue Crack Initiation ◽  
Lead Free ◽  
Lead Free Solder ◽  
Fatigue Reliability ◽  
Shear Fatigue ◽  
Free Solder ◽  
The Relationship

There have been serious debates about whether Pb should be removed from solder joints, in view of environmental problems. These debates have now developed to the extent that a remarkable movement to establish regulations for the removal of Pb has emerged, especially in European countries and Japan. Therefore, Many studies have been aggressively undertaken to develop technologies for replacing Sn-Pb solder with lead-free alternative. From the results obtained so far, it has been proven that the fatigue strength in lead-free solder joints is almost equivalent to the fatigue strength of Sn-Pb eutectic solder joints. However, a new problem is that voids are very easily formed in lead-free solder joints during the reflow process, and the effect of the voids on the fatigue strength of solder joints has attracted attention. In this study, the relationship between the voids and fatigue strength of solder joints was examined using mechanical shear fatigue test and FEM (finite element method) analysis. Using the mechanical shear fatigue test, the effect of the position and size of voids on fatigue crack initiation and crack propagation has been investigated. And quantitative evaluation of fatigue life of solder joints with the voids has been enabled by Manson-Coffin’s law and Miner’ rule.

Isothermal shear fatigue mechanism of lead free solder joints

2012 ◽  
Author(s):  
Huili Xu ◽  
Woong Ho Bang ◽  
Hong-Tao Ma ◽  
Tae-Kyu Lee ◽  
Kuo-Chuan Liu ◽  
...  
Keyword(s):  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
Shear Fatigue ◽  
Free Solder ◽  
Fatigue Mechanism

Microstructures and Properties of SnZn Lead-Free Solder Joints Bearing La for Electronic Packaging

2012 ◽  
Vol 59 (12) ◽  
pp. 3269-3272 ◽  
Author(s):  
Liang Zhang ◽  
Ji-Guang Han ◽  
Yong-Huan Guo ◽  
Cheng-Wen He
Keyword(s):  
Electronic Packaging ◽  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
Free Solder
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