A Fracture Mechanics Analysis of Underfill Delamination in Flip Chip Packages

2005 ◽  
Author(s):  
Saketh Mahalingam ◽  
Sandeep Tonapi ◽  
Suresh K. Sitaraman
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Flip Chip ◽  
Monotonic Loading ◽  
Bending Test ◽  
Organic Substrates ◽  
Loading Conditions ◽  
Underfill Material ◽  
Delamination Propagation

Flip chip technology offers a number of advantages over conventional packaging techniques such as smaller size and efficient high-speed signal transmission. However, when assembled on organic substrates, the flip chip needs to be underfilled with a suitable adhesive to enhance the thermo-mechanical reliability of its solder bumps. When such flip chip assemblies are subjected to thermal excursions, the underfill material may delaminate resulting in premature solder bump fatigue failure. Available open literature has extensively focused on underfill delamination propagation due to monotonic loading conditions. However, the information on underfill fatigue delamination propagation is limited. This paper presents an experimental and modeling study on the underfill delamination under monotonic as well as fatigue loading conditions. In this work, the fracture toughness of the passivation-underfill interface has been characterized using the single leg bending test. In addition, a fatigue delamination propagation experiment has been done, and a Paris law type model for delamination propagation has been developed. In parallel, numerical models have been developed to determine the available energy release rate under monotonic loading conditions as well as the range of energy release rate range under thermal cycling conditions. The mode mixity calculations have been carried out using Crack Surface Displacement (CSD) method. Using the models and the experimental data, guidelines against the delamination of the underfill material are developed.

Interfacial Delamination Propagation in Multi-Layered High-Density Wiring Electronic Packaging Structures

2000 ◽  
Author(s):  
Hurang Hu ◽  
Weidong Xie ◽  
Suresh Sitaraman
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Analytical Model ◽  
Elastic Material ◽  
Release Rate ◽  
Material Properties ◽  
Electronic Packaging ◽  
Base Layer ◽  
Interfacial Delamination ◽  
Delamination Propagation

Abstract One of the most common failure modes in multi-layered electronic packaging structures is interfacial delamination. The objective of this research is to examine the possibilities of interfacial delamination in a next-generation electronic packaging structure under thermal loading. A sophisticated analytical model has been developed to determine energy release rate and stress intensity factor for delamination propagation. The model takes into consideration the temperature-dependent material properties as well as direction-dependent material properties. Although delamination between two adjacent layers is studied, the model takes into consideration the effect of all dielectric, metallization, and substrate layers in the multi-layered structure. Assuming that an initial delamination exists between the base layer and the Copper metallization layer, the present work studies the propagation of delamination. In the analytical model, the base layer is modeled as an orthotropic thermo-elastic material. Copper and the polymer dielectric materials are modeled as isotropic thermo-elastic material. For the Copper/base layer interface, the variation of bimaterial constant (ε) with temperature is obtained through the analytical model. The effect of some key parameters, such as materials Young’s modulus, coefficient of thermal expansion, and the base layer thickness on energy release rate is presented. Design recommendations for improved thermo-mechanical reliability are proposed.

Interfacial Property between Graphite/Epoxy Laminate and MWNTs/Polymer Nanocomposites

2010 ◽  
Vol 123-125 ◽  
pp. 133-136
Author(s):  
Meng Kao Yeh ◽  
Yun Yu Lai
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Polymer Nanocomposites ◽  
Release Rate ◽  
Strain Energy ◽  
Critical Strain ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Bending Test ◽  
Interfacial Property

The interfacial property between graphite/epoxy laminate and multi-walled carbon nanotubes (MWNTs)/polymer nanocomposites was investigated. For the graphite/epoxy laminate, the fiber orientations were varied. For the MWNTs/polymer nanocomposites, the epoxy resins were used as the matrix material and the MWNTs were used as the reinforcement. The weight percentage of MWNTs in the MWNTs/polymer nanocomposites beam specimen was varied. The graphite/epoxy laminate and the MWNTs/polymer nanocomposite beam were glued together by epoxy to make the test specimens. To determine the interfacial property, the end notch flexure (ENF) method was used, and the specimen was placed in a three-point bending test to evaluate the critical strain energy release rate Gc. In analysis, the finite element method was used to obtain the numerical values of the critical strain energy release rate Gc and compared with the experimental ones.

Fracture Analysis of Magnetoelectroelastic Composite Materials

2007 ◽  
Vol 348-349 ◽  
pp. 69-72 ◽  
Author(s):  
R. Rojas-Díaz ◽  
Felipe García-Sánchez ◽  
Andrés Sáez ◽  
Chuan Zeng Zhang
Keyword(s):  
Intensity Factor ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Electric Displacement ◽  
External Boundary ◽  
Loading Conditions ◽  
Magnetoelectroelastic Materials ◽  
Electric Displacement Intensity Factor ◽  
Total Energy Release Rate

This paper presents a crack analysis of linear magnetoelectroelastic materials subjected to static loading conditions. To this end, an efficient boundary element method (BEM) is developed. Unlike many previous investigations published in literature, two-dimensional (2-D) linear magnetoelectroelastic materials possessing fully coupled piezoelectric, piezomagnetic and magnetoelectric effects are considered in this paper. A combination of the displacement BEM and the traction BEM is used in the present formulation. The displacement BEM is applied for the external boundary of the cracked solid, while the traction BEM is used for the crack-faces. A regularization technique is implemented to compute the strongly singular and hypersingular boundary integrals in the BEM. The electric displacement intensity factor (EDIF), the magnetic induction intensity factor (MIIF), the stress intensity factors (SIF), the mechanical strain energy release rate (MSERR) and the total energy release rate (TERR) are evaluated directly from the computed nodal values at discontinuous quarter point elements placed next to the crack tip. The accuracy of the BEM is verified by analytical solutions known in literature. Results are presented for a branched crack in a bending specimen subjected to combined magnetic-electric-mechanical loading conditions.

Calculating Energy Release Rate as a Function of Crack Length Using a Multiple-Step Crack Closure Technique in Tire Finite Element Models

2018 ◽  
Vol 46 (3) ◽  
pp. 130-152
Author(s):  
Dennis S. Kelliher
Keyword(s):  
Finite Element ◽  
Energy Release Rate ◽  
Crack Length ◽  
Energy Release ◽  
Crack Closure ◽  
Release Rate ◽  
Fatigue Behavior ◽  
Three Dimensions ◽  
Quantitative Prediction ◽  
Closure Technique

ABSTRACT When performing predictive durability analyses on tires using finite element methods, it is generally recognized that energy release rate (ERR) is the best measure by which to characterize the fatigue behavior of rubber. By addressing actual cracks in a simulation geometry, ERR provides a more appropriate durability criterion than the strain energy density (SED) of geometries without cracks. If determined as a function of crack length and loading history, and augmented with material crack growth properties, ERR allows for a quantitative prediction of fatigue life. Complications arise, however, from extra steps required to implement the calculation of ERR within the analysis process. This article presents an overview and some details of a method to perform such analyses. The method involves a preprocessing step that automates the creation of a ribbon crack within an axisymmetric-geometry finite element model at a predetermined location. After inflating and expanding to three dimensions to fully load the tire against a surface, full ribbon sections of the crack are then incrementally closed through multiple solution steps, finally achieving complete closure. A postprocessing step is developed to determine ERR as a function of crack length from this enforced crack closure technique. This includes an innovative approach to calculating ERR as the crack length approaches zero.

scholarly journals Effect of the Characteristic Size and Content of Graphene on the Crack Propagation Path of Alumina/Graphene Composite Ceramics

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 611
Author(s):  
Benshuai Chen ◽  
Guangchun Xiao ◽  
Mingdong Yi ◽  
Jingjie Zhang ◽  
Tingting Zhou ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Volume Content ◽  
Phase Interface ◽  
Average Energy ◽  
Characteristic Size ◽  
Composite Ceramics ◽  
Graphene Composite

In this paper, the Voronoimosaic model and the cohesive element method were used to simulate crack propagation in the microstructure of alumina/graphene composite ceramic tool materials. The effects of graphene characteristic size and volume content on the crack propagation behavior of microstructure model of alumina/graphene composite ceramics under different interfacial bonding strength were studied. When the phase interface is weak, the average energy release rate is the highest as the short diameter of graphene is 10–50 nm and the long diameter is 1600–2000 nm. When the phase interface is strong, the average energy release rate is the highest as the short diameter of graphene is 50–100 nm and the long diameter is 800–1200 nm. When the volume content of graphene is 0.50 vol.%, the average energy release rate reaches the maximum. When the velocity load is 0.005 m s−1, the simulation result is convergent. It is proven that the simulation results are in good agreement with the experimental phenomena.

Sign in / Sign up

Export Citation Format

Share Document