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

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.

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.

Void Formation and Their Effect on Reliability of Lead-Free Solder Joints on MID and PCB Substrates

2017 ◽  
Vol 66 (4) ◽  
pp. 1229-1237 ◽  
Author(s):  
P. Wild ◽  
T. Grozinger ◽  
D. Lorenz ◽  
A. Zimmermann
Keyword(s):  
Solder Joints ◽  
Void Formation ◽  
Lead Free ◽  
Lead Free Solder ◽  
Free Solder

Quantitative Evaluation of Voids in Lead Free Solder Joints

2015 ◽  
Vol 772 ◽  
pp. 284-289 ◽  
Author(s):  
Sabuj Mallik ◽  
Jude Njoku ◽  
Gabriel Takyi
Keyword(s):  
Solder Bump ◽  
Solder Joints ◽  
Void Formation ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Paste ◽  
X Ray ◽  
Size And Shape ◽  
Solder Bumps ◽  
Free Solder

Voiding in solder joints poses a serious reliability concern for electronic products. The aim of this research was to quantify the void formation in lead-free solder joints through X-ray inspections. Experiments were designed to investigate how void formation is affected by solder bump size and shape, differences in reflow time and temperature, and differences in solder paste formulation. Four different lead-free solder paste samples were used to produce solder bumps on a number of test boards, using surface mount reflow soldering process. Using an advanced X-ray inspection system void percentages were measured for three different size and shape solder bumps. Results indicate that the voiding in solder joint is strongly influenced by solder bump size and shape, with voids found to have increased when bump size decreased. A longer soaking period during reflow stage has negatively affectedsolder voids. Voiding was also accelerated with smaller solder particles in solder paste.

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