A hybrid model for computationally efficient fatigue fracture simulations at microelectronic assembly interfaces

Towashiraporn, P.; Subbarayan, Ganesh; Desai, C. S.

doi:10.1016/j.ijsolstr.2004.12.012

Cited by 59 publications

(37 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Towashiraporn et al [73] simulated crack growth in a BGA joint using a homogeneous isotropic solder model and cohesive elements at the copper-solder interface. It was found that the simulated crack growth corresponds well with the experimentally determined crack growth.…”

Section: Motivationmentioning

confidence: 99%

A robust preconditioning technique for the extended finite element method

Menk

Bordas

2010

Numerical Meth Engineering

140

View full text Add to dashboard Cite

In electronic devices solder joints form a mechanical as well as an electrical connection between the circuit board and the component (e.g. a chip or a resistor). Temperature variations occurring during field use cause crack initiation and crack growth inside the joints. Accurate prediction of the lifetime requires a method to simulate the damage process based on microstructural properties.Numerical simulation of developing cracks and microstructural entities such as grain boundaries and grain junctions gives rise to several problems. The solution contains strong and weak discontinuities as well as weak singularities. To obtain reasonable solutions with the finite element method (FEM) the element edges have to align with the cracks and the grain boundaries, which imposes geometrical restrictions on the mesh choice. Additionally, a large number of elements has to be used in the vicinity of the singularities which increases the computational effort. Both problems can be circumvented with the extended finite element method (X-FEM) by using appropriate enrichment functions.In this thesis the X-FEM will be developed for the simulation of complex microstructural geometries. Due to the anisotropy of the different grains forming a joint and the variety of different microstructural configurations it is not always possible to write the enrichment functions in a closed form. A procedure to determine enrichment functions numerically is explained and tested. As a result, a very simple meshing scheme, which will be introduced here, can be used to simulate developing cracks in solder joint microstructures. Due to the simplicity of the meshing algorithm the simulation can be automated completely. A large number of enrichment functions must be used to realize this. Well-conditioned equation systems, however, cannot be guaranteed for such an approach. To improve the condition number of the X-FEM stiffness matrix and thus the robustness of the solution process a preconditioning technique is derived and applied.This approach makes it possible to develop a new and fully automated procedure for addressing the reliability of solder joints numerically. The procedure relies on the random generation of microstructures. Performing crack growth calculations for a series of these structures makes it possible to address the influence of varying microstructures on the damage process. Material parameters describing the microstructure are determined in an inverse procedure. It will be shown that the numerical results correspond well with experimental observations.

show abstract

Section: Motivationmentioning

confidence: 99%

A robust preconditioning technique for the extended finite element method

Menk

Bordas

2010

Numerical Meth Engineering

140

View full text Add to dashboard Cite

show abstract

“…The microstructure of the solder is changed by the temperature and thermal strain by the difference of thermal expansion 5) .…”

Section: ) High Temperature Storage Testmentioning

confidence: 99%

Effects of Microstructural Changes of the Solder Joint Under Thermal Loading on the Life Under Vibrational Loading

Matsushima

Matsuo

Fukumoto

et al. 2014

Journal of Smart Processing

View full text Add to dashboard Cite

The microstructure changes of solder joint caused by heat cycle load influence on the life against the thermal cycle loading. The creep characteristic changes were more influential than other parameters such as Young s modulus or yield stress. The thermal cycle loading consists of the heat and repeated mechanical strain. In this study, the effects of the material parameter changes caused by the microstructure change with thermal loading on the life against vibration load are estimated by FEM analysis focusing on the BGA solder joint as an example. The crack initiation caused by the mechanical load depends on the strain at the concentrated point of the solder joint. It has already been reported that the creep strain does not appear in the high strain rate loading such as vibration. The microstructure and material property changes caused by the high-temperature environment are measured. And the effect of the yield stress change on the strain under the vibration load is investigated with FEM analysis. The vibration test of the BGA mounted board with and without pre-thermal loading represented the deteriorated life of the solder joint caused by the thermal loading.

show abstract

“…Fatigue life predictions for BGA or flip-chip sol- der balls are generally conducted using Coffin-Manson, J-integral, power law or creep models (Tchankov et al 2008;Desai et al 1998;Li and Wang 2007;Tee et al 2003;Zhang et al 2008). In Towashiraporn et al (2005), the fatigue crack trajectory and fatigue life of a solder joint is predicted through a coupled numericalexperimental approach. A review on solder joint fatigue models with respect to their applicability to chip-scale packages is given in Lee et al (2000).…”

Section: Introductionmentioning

confidence: 99%

Fatigue fracture of SnAgCu solder joints by microstructural modeling

et al. 2008

View full text Add to dashboard Cite

The ongoing miniaturization trend in the microelectronic industry enforces component sizes to approach the micron, or even the nano scale. At these scales, the underlying microstructural sizes and the geometrical dimensions are comparable. The increasing influence of microscopic entities on the overall mechanical properties makes conventional continuum material models more and more questionable. In this study, the thermomechanical reliability of lead-free BGA solder balls is investigated by microstructural modeling. Microstructural input is provided by orientation imaging microscopy (OIM), converted into a finite element framework. Blowholes in BGA solder balls are examined by optical microscopy and a statistical analysis on their size, position and frequency is conducted. Combining the microstructural data with the appropriate material models, three dimensional local models are created. The fatigue life of the package is determined through a critical solder ball. The thermomechanical reliability of the local models are predicted using cohesive zone based fatigue damage models. The simulation results are validated by statistical analyses provided by the industry.

show abstract

A hybrid model for computationally efficient fatigue fracture simulations at microelectronic assembly interfaces

Cited by 59 publications

References 18 publications

A robust preconditioning technique for the extended finite element method

A robust preconditioning technique for the extended finite element method

Effects of Microstructural Changes of the Solder Joint Under Thermal Loading on the Life Under Vibrational Loading

Fatigue fracture of SnAgCu solder joints by microstructural modeling

Contact Info

Product

Resources

About