Creep Behavior of a Flip-Chip Package by Both FEM Modeling and Real Time Moire´ Interferometry

1998 ◽  
Vol 120 (2) ◽  
pp. 179-185 ◽  
Author(s):  
J. Wang ◽  
Z. Qian ◽  
D. Zou ◽  
S. Liu
Keyword(s):  
Finite Element ◽  
Creep Behavior ◽  
Thermal Load ◽  
Flip Chip ◽  
Moiré Interferometry ◽  
Moire Interferometry ◽  
Initial State ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Solder Balls

In this paper, the creep behavior of a flip-chip package under a thermal load was investigated by using nonlinear finite element technique coupled with high density laser moire´ interferometry. The real-time moire´ interferometry technique was used to monitor and measure the time-dependent deformation of flip-chip packages during the test, while the finite element method was adapted to analyze the variation of stresses at edges and corners of interfaces with time by considering the viscoelastic properties of the underfill and the viscoplastic behavior of the solder balls. The results show that the creep behavior of the underfill and the solder balls does not have significant effect on the warpage of the flip-chip under the considered thermal load due to their constrained small volume. The variation of the time-dependent deformation in the flip-chip package caused by the creep behavior of the underfill and the solder balls is in the submicro scale. The maximum steady-state U-displacement is only reduced by up to 6.7 percent compared with the maximum initial state U-displacement. Likewise, the maximum steady-state V-displacement is merely reduced by up to 10 percent compared with the maximum initial state V-displacement. The creep behavior slightly weakens the warpage situation of the flip-chip package. However, the modeling results show that the localized stresses at corners and edges of interfaces greatly decrease due to the consideration of viscoelastic properties of the underfill and the viscoplastic properties of the solder balls, and, thereby, effectively preventing interfaces from cracking. In addition, the predicted deformation values of the flip-chip package obtained from the finite element analysis were compared with the test data obtained from the laser moire´ interferometry technique. It is shown that the deformation values of the flip-chip package predicted from the finite element analysis are in a fair agreement with those obtained from the test.

In‐Situ Mapping and Modeling Verification of Thermomechanical Deformation in Underfilled Flip‐Chip Packaging Using Moiré Interferometry

1996 ◽  
Vol 445 ◽  
Author(s):  
Xiang Dai ◽  
Connie Kim ◽  
Ralf Willecke ◽  
Paul S. Ho
Keyword(s):  
Flip Chip ◽  
Thermal Loading ◽  
Deformation Monitoring ◽  
Moiré Interferometry ◽  
Moire Interferometry ◽  
Fringe Analysis ◽  
Element Analysis ◽  
Solder Bumps ◽  
Thermomechanical Deformation

AbstractAn experimental technique of environmental moiré interferometry has been developed for in‐situ monitoring and analysis of thermomechanical deformation of microelectronics packages subjected to thermal loading under a controlled atmosphere. Coupled with fractional fringe analysis and digital image processing, the environmental moiré interferometry technique achieves accurate and realistic deformation monitoring with high sensitivity and excellent spatial resolution. It has been applied to investigate the thermomechanical deformations induced by thermal loading in an underfilled flip‐chip‐on‐board packaging. The effects of temperature change in the range of 102 °C to 22 °C are analyzed for underfill and solder bumps. In addition, shear deformation and shear strains across the solder bumps are determined as a function of temperature. The experimental results are compared with the results of a finite element analysis for modeling verification. Good agreement between the modeling results and experimental measurements has been found in the overall displacement fields. Through this study, the role of underfill in the thermomechanical deformation of the underfilled flip‐chip package is determined.

Process Induced Stresses of a Flip-Chip Packaging by Sequential Processing Modeling Technique

1998 ◽  
Vol 120 (3) ◽  
pp. 309-313 ◽  
Author(s):  
J. Wang ◽  
Z. Qian ◽  
S. Liu
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Field ◽  
Flip Chip ◽  
Residual Stress Field ◽  
Element Analysis ◽  
Sequential Processing ◽  
The Finite Element Analysis ◽  
Flip Chip Packaging ◽  
The Given

In this paper, a nonlinear finite element framework was established for processing mechanics modeling of flip-chip packaging assemblies and relevant layered manufacturing. In particular, topological change was considered in order to model the sequential steps during the flip-chip assembly. Geometric and material nonlinearity, which includes the viscoelastic properties of underfill and the viscoplastic properties of solder alloys, were considered. Different stress-free temperatures for different elements in the same model were used to simulate practical manufacturing process-induced thermal residual stress field in the chip assembly. As comparison, two FEM models (processing model and nonprocessing model) of the flip-chip package considered, associated with different processing schemes, were analyzed. From the finite element analysis, it is found that the stresses and deflections obtained from nonprocessing model are generally smaller than those obtained from the processing model due to the negligence of the bonding process-induced residual stresses and warpage. The stress values at the given point obtained from the processing model are about 20 percent higher than those obtained from the nonprocessing model. The deflection values at the given points obtained from the processing model are usually 25 percent higher than those obtained from the nonprocessing model. Therefore, a bigger error may be caused by using nonprocessing model in the analysis of process-induced residual stress field and warpage in the packaging assemblies.

Measurement of Creep and Relaxation Behaviors of Wafer-Level CSP Assembly Using Moire´ Interferometry

2003 ◽  
Vol 125 (2) ◽  
pp. 282-288 ◽  
Author(s):  
Suk-Jin Ham ◽  
Soon-Bok Lee
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Real Time ◽  
Room Temperature ◽  
Moiré Interferometry ◽  
Moire Interferometry ◽  
Wafer Level ◽  
Element Analysis ◽  
The Real ◽  
Thermal Chamber

In this paper, the creep and relaxation behaviors of a wafer-level CSP assembly under two types of thermal loading conditions were investigated using high sensitivity moire´ interferometry. One is a thermal load from 100°C to room temperature and the other is from room temperature to 100°C. In the second case, the real-time technique was used to monitor and measure the shear deformations of solder joints and the warpage of the assembly during the test. For the real-time measurements of thermal deformations, a small-sized thermal chamber having an optical window was developed. In addition, the test results obtained from the moire´ interferometry measurements were compared with the predicted values obtained from finite element analysis. It is shown that the deformation values predicted from finite element analysis have a good agreement with those obtained from the tests.

Finite Element Analysis of a Proposed New Express Car Wheel Design

2002 ◽  
Author(s):  
Gregory Gagarin ◽  
Cameron Lonsdale ◽  
James Pilch ◽  
Steven Dedmon
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Computer Simulations ◽  
Thermal Load ◽  
Thermal Loading ◽  
Development Work ◽  
Element Analysis ◽  
Braking System ◽  
The Finite Element Analysis ◽  
Future Work

This paper describes the engineering development work associated with a new wheel design intended for use under a proposed new, 256,000 pounds gross rail load (GRL) express car to be run at speeds up to 110 mph. Initial project assumptions are reviewed, and the new car’s proposed combination disc/tread braking system is described. Several assumed braking scenarios, based upon different thermal loading scenarios including a grade braking sequence to be experienced by the proposed new car in service, were used to determine the braking (thermal) load inputs for the finite element analysis (FEA) work. Wheel stress and temperature results from the various FEA computer simulations are reviewed and discussed in the context of wheel suitability and safety. Recommendations for future work are also discussed.

Interactive Graphics for the Analysis of Tires

1985 ◽  
Vol 13 (3) ◽  
pp. 127-146 ◽  
Author(s):  
R. Prabhakaran
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Approximate Solutions ◽  
Interactive Graphics ◽  
Element Analysis ◽  
Analysis Process ◽  
Physical Problems ◽  
The Finite Element Analysis ◽  
Analysis Computer ◽  
Discretization Technique

Abstract The finite element method, which is a numerical discretization technique for obtaining approximate solutions to complex physical problems, is accepted in many industries as the primary tool for structural analysis. Computer graphics is an essential ingredient of the finite element analysis process. The use of interactive graphics techniques for analysis of tires is discussed in this presentation. The features and capabilities of the program used for pre- and post-processing for finite element analysis at GenCorp are included.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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