Effects of Strain Rate and Amplitude Variations on Solder Joint Fatigue Life in Isothermal Cycling

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Sa'd Hamasha ◽  
Peter Borgesen
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Strain Rate ◽  
Solder Joints ◽  
Constitutive Relations ◽  
Snagcu Solder ◽  
Shear Fatigue ◽  
Deformation Properties ◽  
Service Conditions ◽  
Solder Joint Fatigue

The behavior of lead-free solder alloys under realistic service conditions is still not well understood. Life prediction of solder joints relies on conducting accelerated tests and extrapolating results to service conditions. This can be very misleading without proper constitutive relations and without understanding the effects of cycling parameter variations common under realistic service conditions. It has been shown that the fatigue life depends on the inelastic work accumulation, independently of cycling-induced material property variations, which explains the breakdown of damage accumulation rules and allows the development of a modified Miner's rule. This paper discusses the interacting effects of strain rate and amplitude variations on solder joint fatigue life. Individual SnAgCu solder joints with two different Ag contents (SAC305 and SAC105) were tested in low cycling shear fatigue under single and varying amplitudes with different strain rates. Such a shear fatigue experiment allows the measurement of work accumulation and the evolution of solder deformation properties during cycling. The results showed that cycling with a lower strain rate at fixed amplitude causes more damage per cycle. Alternating between mild amplitude at a high strain rate and harsh amplitude at a low strain rate leads to ongoing increases in the rate of damage at the mild amplitude and thus relatively rapid failure. In comparing SAC305 with SAC105, the effect of strain rate on both alloys is almost the same, and SAC305 is still more fatigue resistant than SAC105 in varying amplitude cycling with any strain rate.

scholarly journals Effect of Cycling Amplitude Variations on SnAgCu Solder Joint Fatigue Life

2018 ◽  
Vol 8 (11) ◽  
pp. 1896-1904 ◽  
Author(s):  
Sa'd Hamasha ◽  
Francy Akkara ◽  
Sinan Su ◽  
Haneen Ali ◽  
Peter Borgesen
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Snagcu Solder ◽  
Solder Joint Fatigue

Assessment of Solder Joint Fatigue Life Under Realistic Service Conditions

2014 ◽  
Vol 43 (12) ◽  
pp. 4472-4484 ◽  
Author(s):  
Sa’d Hamasha ◽  
Younis Jaradat ◽  
Awni Qasaimeh ◽  
Mazin Obaidat ◽  
Peter Borgesen
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Service Conditions ◽  
Solder Joint Fatigue

Design for Solder Joint Fatigue Life of BGA Package Subject to Mechanical Environment

2013 ◽  
Vol 2013 (1) ◽  
pp. 000250-000259
Author(s):  
Jia-Shen Lan ◽  
Mei-Ling Wu
Keyword(s):  
Fatigue Life ◽  
Analytical Solution ◽  
Solder Joint ◽  
Solder Joints ◽  
Assessment Model ◽  
Personal Digital Assistants ◽  
Pcb Assembly ◽  
Bga Package ◽  
Mechanical Bending ◽  
Solder Joint Fatigue

There has been a dramatic proliferation of research concerned with thermal stress in electronic package for the last three decades. Moreover, reviewing the mechanical bending during printed circuit board (PCB) assembly has become important in the reliability assessment of modern electronic systems. The primary research demonstrates that the assessment approach can be applied successfully to the design model of a ball grid array (BGA) package with a more complete and accurate assessment model for solder joint fatigue life under mechanical bending. Previous research has focused mostly on the thermal analysis in electronic packages; however, most modern portable electronic products used in mobile devices, personal digital assistants, and aircraft have to endure extreme environments that involve not only thermal but also mechanical bending conditions. Initially, mechanical bending tests were conducted to demonstrate the reliability of the electronic packaging during the manufacturing and shipping process. Currently, the microelectronic packaging faces mechanical bending when everyone uses his or her Smartphones. The mechanical bending occurs when the user touches the screen on the Smartphone. Therefore, interest in the mechanical bending of BGA packaging has increased with the uptake in mobile device use. In this research, the analytical solution and finite element analysis (FEA) are both presented to investigate the solder joint fatigue life. The analytical solution is presented for a PCB assembly subjected to mechanical bending by taking the axial stress, shear stress, and moment of the solder joints with discontinuity function into account. A FEM is proposed to analyze the solder joint fatigue life and to investigate the reliability of solder joints in BGA packaging subjected to mechanical bending.

Assembly Stiffness and Failure Criterion Considerations in Solder Joint Fatigue

1990 ◽  
Vol 112 (2) ◽  
pp. 115-122 ◽  
Author(s):  
J. R. Wilcox ◽  
R. Subrahmanyan ◽  
Che-Yu Li
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Failure Criterion ◽  
Damage Accumulation ◽  
Damage Parameter ◽  
Time Profile ◽  
Joint Area ◽  
Fatigue Damage Accumulation ◽  
Deformation Properties ◽  
Solder Joint Fatigue

The ramifications of the definition of failure on solder joint fatigue life are discussed in terms of two considerations: (1) the dependence of the measured damage parameter (load drop or resistance increase) on the solder joint area and (2) the time profile of solder joint area. The latter is influenced by the applied displacement profile, the assembly stiffness, the deformation properties of the solder joint, and the dependence of rate of fatigue damage accumulation on its driving force. Experimental data are presented to illustrate the influence of these considerations on failure criterion. An integral methodology is used for the description of damage accumulation. Representative simulations are performed that demonstrate failure criterion effects on apparent fatigue life. Isothermal mechanical displacement controlled cyclic loading is emphasized. The principles presented may also be applied to thermal cycling of solder interconnects.

scholarly journals Prediction of mechanical properties and fatigue life of nano silver paste in chip interconnection

2020 ◽  
Author(s):  
Hui YANG ◽  
Jihui Wu
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Solder Joints ◽  
Stress And Strain ◽  
Nano Silver ◽  
Finite Element Software ◽  
Flip Chips ◽  
Empirical Correction ◽  
Prediction Of Mechanical Properties

Abstract The simulation of nano-silver solder joints in flip-chips is performed by the finite element software ANSYS, and the stress-strain distribution results of the solder joints are displayed. In this simulation, the solder joints use Anand viscoplastic constitutive model, which can reasonably simulate the stress and strain of solder joints under thermal cycling load. At the same time this model has been embedded in ANSYS software, so it is more convenient to use. The final simulation results show that the areas where the maximum stresses and strains occur at the solder joints are mostly distributed in the contact areas between the solder joints and the copper pillars and at the solder joints. During the entire thermal cycling load process, the area where the maximum change in stress and strain occurs is always at the solder joint, and when the temperature changes, the temperature at the solder joint changes significantly. Based on comprehensive analysis, the relevant empirical correction calculation equation is used to calculate and predict the thermal fatigue life of nano-silver solder joints. The analysis results provide a reference for the application of nano-silver solder in the electronic packaging industry.

Reliability of SAC 105 and SAC1205N under Drop Tests

2016 ◽  
Vol 2016 (1) ◽  
pp. 000106-000110
Author(s):  
Jia-Shen Lan ◽  
Stuwart Fan ◽  
Louie Huang ◽  
Mei-Ling Wu
Keyword(s):  
Fatigue Life ◽  
Solder Joint ◽  
Simulation Model ◽  
Drop Test ◽  
Test Execution ◽  
Fine Pitch ◽  
Mechanical Shocks ◽  
Drop Tests ◽  
Solder Joint Fatigue ◽  
Package Reliability

Abstract In this paper, the solder joint failure and the solder joint fatigue life in the Thin-profile Fine-pitch Ball Grid Array (TFBGA) Package was investigated by performing the drop test, and implementing a simulation model. Owing to the need to meet the increasing demands for functionality, microelectronic package reliability can be compromised and has become the key issue when executing drop tests. During impact in drop test, the deformation of PCB due to bending and mechanical shocks can cause solder joint crack. While this is a well-known issue, observing the solder joint responses during the test execution can be a challenge. Therefore, in this work, a simulation model approach has been developed to investigate the stress and strain of the solder joint during the drop test. In this research, the JEDEC Condition B drop test was simulated, characterized by 1500G peak acceleration and 0.5 ms duration. The drop test simulation model was successful in predicting the solder joint fatigue life with different solder joint materials, such as SAC105 and SAC1205N, while also facilitating result comparison to identify the most optimal structure.

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