Strain based approach for predicting the solder joint fatigue life with the addition of intermetallic compound using finite element modeling

2004 ◽  
Author(s):  
M.M. Hossain ◽  
D. Agonafer ◽  
P. Viswanadham ◽  
T. Reinikainen
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Intermetallic Compound ◽  
Solder Joint ◽  
Finite Element Modeling ◽  
Element Modeling ◽  
Solder Joint Fatigue

The Effect of Intermetallic Compound in Solder Joint Fatigue Life Prediction Using Finite Element Modeling

2003 ◽  
Author(s):  
Mohammad Masum Hossain ◽  
Dereje Agonafer ◽  
Puligandla Viswanadham ◽  
Tommi Reinikainen
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Intermetallic Compound ◽  
Solder Joint ◽  
Finite Element Modeling ◽  
Life Prediction ◽  
Temperature Cycling ◽  
Fatigue Life Prediction ◽  
Element Modeling ◽  
Solder Joint Fatigue

The life-prediction modeling of an electronic package requires a sequence of critical assumptions concerning the finite element models. The solder structures accommodate the bulk of the plastic strain that is generated during accelerated temperature cycling due to the thermal expansion mismatch between the various materials that constitute the package. Finite element analysis is extensively used for simulating the effect of accelerated temperature cycling on electronic packages. There are a number of issues that need to be addressed to improve the current FEM models. One of the limitations inherent to the presently available models is the accuracy in property values of eutectic 63Sn/37Pb solder or other solder materials (i.e. 62Sn/36Pb/2Ag). Life prediction methodologies for high temperature solders (90Pb/10Sn, 95Pb/5Sn, etc.) or lead-free based inter-connects materials, are almost non-existent due to their low volume use or relative infancy. [1] Another major limitation for the models presently available is excluding the effect of intermetallic compound (Cu6Sn5, Cu3Sn) formation and growth between solder joint and Cu pad due to the reflow processes, rework and during the thermal aging. The mechanical reliability of these intermetallic compounds clearly influences the mechanical integrity of the interconnection. The brittle failures of solder balls have been identified with the growth of a number of intermetallic compounds both at the interfaces between metallic layers and in the bulk solder balls. In this paper, the effect of intermetallic compound in fatigue life prediction using finite element modeling is described. A Chip Scale Package 3D Quarter model is chosen to do the FE analysis. Accelerated temperature cycling is performed to obtain the plastic work due to thermal expansion mismatch between the various materials. Solder joint fatigue life prediction methodologies were incorporated so that finite element simulation results were translated into estimated cycles to failure. The results are compared with conventional models that do not include intermetallic effects. Conventionally available material properties are assumed for the eutectic 63Sn/37Pb solder and the intermetallic material properties. The importance of including intermetallic effect in finite element modeling will be discussed.

Gull-Wing Solder Joint Fatigue Life Sensitivity Evaluation

1997 ◽  
Vol 119 (3) ◽  
pp. 171-176 ◽  
Author(s):  
T. E. Wong ◽  
L. A. Kachatorian ◽  
B. D. Tierney
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Solder Joint ◽  
Sensitivity Evaluation ◽  
Minimum Number ◽  
Parametric Studies ◽  
Solder Joint Fatigue ◽  
The Impact ◽  
Joint Assembly

A Taguchi design of experiment approach was applied to thermostructural analyses of a gull-wing solder joint assembly. This approach uses a minimum number of finite element analyses to evaluate the impact of solder joint assembly parameters on fatigue life of the assembly. To avoid costly complex modeling efforts for each parametric case study, a commercially available program, MSC/PATRAN’s PATRAN Command Language, was used to automatically create finite element models of a two-dimensional gull-wing solder joint assembly based on nine parameters. Modeling time was dramatically reduced from days to a few minutes for each detailed lead/solder model. Two sets of parametric studies were conducted to evaluate the impact of variation of the six parameters. The analysis results indicate that lead ankle radius is the most critical parameter affecting solder joint total fatigue life, and lead and minimum solder thicknesses are the next most critical ones. Therefore, to effectively improve the solder joint fatigue life margin, it is recommended to: (1) increase the minimum solder thickness; (2) use thinner lead; and (3) use a larger lead ankle radius, even though this may require reducing lead shin length. By implementing only the last recommendation to modify the current solder joint assembly, the fatigue life margin in this design could, in general, be improved by 27 percent or more.

Application of Artificial Neural Network for Fatigue Life Prediction

2005 ◽  
Vol 297-300 ◽  
pp. 96-101
Author(s):  
Ishak Abdul Azid ◽  
Lee Kor Oon ◽  
Ong Kang Eu ◽  
K.N. Seetharamu ◽  
Ghulam Abdul Quadir
Keyword(s):  
Neural Network ◽  
Finite Element ◽  
Fatigue Life ◽  
Solder Joint ◽  
Finite Element Simulation ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Element Simulation ◽  
Parametric Studies ◽  
Solder Joint Fatigue

An extensively published and correlated solder joint fatigue life prediction methodology is incorporated by which finite element simulation results are translated into estimated cycles to failure. This study discusses the analysis methodologies as implemented in the ANSYSTM finite element simulation software tool. Finite element models are used to study the effect of temperature cycles on the solder joints of a flip chip ball grid array package. Through finite element simulation, the plastic work or the strain-energy density of the solder joints are determined. Using an established methodology, the plastic work obtained through simulation is translated into solder joint fatigue life [1]. The corresponding results for the solder joint fatigue life are used for parametric studies. Artificial Neural Network (ANN) has been used to consolidate the parametric studies.

Modeling of Underfilled PBGA Assemblies Using Both Viscoelastic and Elastic Material Properties

2019 ◽  
Author(s):  
Promod R. Chowdhury ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Solder Joint ◽  
Viscoelastic Properties ◽  
Computational Cost ◽  
Viscoelastic Behavior ◽  
Polymer Materials ◽  
Temperature Dependent ◽  
Solder Joint Fatigue ◽  
Underfill Material

Abstract In microelectronics packaging industry, polymer based materials are used extensively. These polymer materials show viscoelastic behavior when subject to time dependent loads or deformations. The viscoelastic behavior highly depends on both temperature and time. In many cases, these viscoelastic properties are often neglected due to saving computational cost or unavailability of full characterization of the viscoelastic properties. To make accurate predictions of packaging mechanical behavior and reliability, it is important to accurately characterize the viscoelastic behavior of mold compounds, underfill encapsulants, adhesives and other polymers used in electronic assemblies. After characterization, these parameters can be used as input material property data for finite element analysis (FEA) simulations. In this study, both frequency dependent dynamic mechanical analysis (DMA) measurements, and strain and temperature dependent stress relaxation experiments were performed on a typical underfill material in order to characterize its linear viscoelastic behavior. In both cases, a master curve was determined using the assumption of time-temperature equivalence, and Prony series expansions were utilized to model the underfill material relaxation behavior. After that, these viscoelastic underfill material parameters were used in finite element models of underfilled ball grid array packages (Ultra CSP) subjected to thermal cycling from −40 to 125 °C. Separate simulations were also performed using temperature dependent elastic properties for the underfill material. In both cases, the solder joint fatigue life was estimated, and the effects of using viscoelastic properties for the underfill in solder joint fatigue life simulation were investigated.

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