Warpage of Flip Chip BGA Package

2006 ◽  
Author(s):  
Milena Vujosevic
Keyword(s):  
Flip Chip ◽  
Plate Theory ◽  
Contour Plot ◽  
Thermally Induced ◽  
Ball Grid Arrays ◽  
Fundamental Understanding ◽  
Out Of Plane ◽  
Bga Package ◽  
Plane Displacement ◽  
Analytical Expressions

The work focuses on the thermally induced out of plane displacement of Flip Chip Ball Grid Arrays (FCBGA). Analytical expressions for substrate displacements are derived based on the Plate Theory and Suhir's solution for stresses in tri-material assembly. The validity of the model is established by comparing the analytical solution to the finite element results as well as to the experimental data. The benefits of the model are twofold: 1) it provides a tool for fundamental understanding of the parameters that influence warpage, and 2) has a predictive capability. With respect to 1) an analysis is presented on the nature and degree of influence that different geometric and material parameters have on the FCBGA warpage. With respect to 2) the "Warpage Contour Plot" is proposed as a tool for warpage prediction that can be easily utilized in the early stages of the design process.

scholarly journals Thermally induced deformations in die-substrate assembly

2008 ◽  
Vol 35 (1-3) ◽  
pp. 305-322 ◽  
Author(s):  
Milena Vujosevic
Keyword(s):  
Flip Chip ◽  
Plate Theory ◽  
Contour Plot ◽  
Predictive Capability ◽  
Thermally Induced ◽  
Ball Grid Arrays ◽  
Proposed Model ◽  
Fundamental Understanding ◽  
Numerical Finite Element ◽  
Analytical Expressions

The work focuses on the thermally induced deformations caused by the processing of Flip Chip Ball Grid Arrays (FCBGA). Analytical expressions for substrate displacements are derived based on the Plate Theory and Suhir's solution for stresses in tri-material assembly. The validity of the model is established by comparing the analytical solution to the numerical finite element results as well as to the experimental data. The benefits of the proposed model are twofold: 1) it provides a tool for fundamental understanding of the deformation process of interest, and 2) has a predictive capability. More specifically, an analysis is presented on the nature and degree of influence that different geometric and material parameters have on the substrate deflections, as well as a "Warpage Contour Plot", proposed as a tool for warpage prediction that can be easily utilized in the early stages of the design process.

Thermoelastic Actuation: Solution for Circular Composite Plates With Application in MEMS

2002 ◽  
Author(s):  
Venkataraman Chandrasekaran ◽  
Mark Sheplak ◽  
Louis N. Cattafesta ◽  
Bhavani V. Sankar
Keyword(s):  
Heat Conduction ◽  
Joule Heating ◽  
Plate Theory ◽  
Composite Plates ◽  
Mechanical Analysis ◽  
Conduction Model ◽  
Time Harmonic ◽  
Out Of Plane ◽  
Fourier Heat Conduction ◽  
Analytical Expressions

This paper presents the dynamic analysis of a thermoelastically actuated circular composite diaphragm, for MEMS applications. The diaphragm is used as an acoustic transmitter, actuated at ultrasonic frequencies via a diffused surface heater at its center. The principle of operation of the thermal actuator is the generation of an oscillating temperature gradient across the diaphragm cross-section due to Joule heating of the diffused heater, creating a thermal moment that results in out-of-plane bending of the diaphragm. The mechanical analysis of the diaphragm, modeled as a composite plate, is based on the classical laminated plate theory. The time harmonic heat conduction resulting from the Joule heating of the diffused surface heater, modeled as a surface heat flux input, is analyzed using the Fourier heat conduction model. Analytical expressions have been obtained for the temperature distribution, and the resulting thermal moment, and plate deflection.

Buckling Analysis of Mindlin Plates Under the Green–Lagrange Strain Hypothesis

2015 ◽  
Vol 15 (06) ◽  
pp. 1450079 ◽  
Author(s):  
Eugenio Ruocco ◽  
Vincenzo Minutolo
Keyword(s):  
Solution Method ◽  
Plate Theory ◽  
Mode Shapes ◽  
Governing Equations ◽  
Nonlinear Strain ◽  
Out Of Plane ◽  
Plates And Shells ◽  
Moderately Thick Plates ◽  
Lagrange Strain ◽  
Plane Displacement

In the present paper, the influence of Green–Lagrange nonlinear strain-displacement terms, usually considered negligible under the von Kármán hypothesis, on the buckling of isotropic, moderately thick plates and shells, is investigated. The first order shear deformation plate theory is applied and the governing equations, containing nonlinear terms related to both in-plane displacement and out-of-plane rotations usually ignored in the literature, are derived using the principle of minimum of the strain energy. The general Levy type solution method is employed, and exact buckling loads and mode shapes are derived. To verify the accuracy of the solution obtained, comparisons with existing data are first made. Then, through graphics and tables, the effect of the nonlinear strain-displacement terms for a range of boundary and load conditions, variations of aspect ratio, thickness ratio and changes in geometry is presented. The results obtained show that the von Kármán's model can sensibly overestimate the critical load for structures characterized by the modes involving comparable in-plane and out-of-plane displacements.

Thermo-Mechanical Deformation and Stress Analysis of a Flip-Chip BGA

2003 ◽  
Author(s):  
J. D. Wu ◽  
Y. S. Lai ◽  
Y. L. Kuo ◽  
S. C. Hung ◽  
M.-H. R. Jen
Keyword(s):  
Flip Chip ◽  
Thermal Loading ◽  
Mechanical Deformation ◽  
Substrate Thickness ◽  
Inelastic Material ◽  
Out Of Plane ◽  
Cte Mismatch ◽  
Constitutive Response ◽  
Chip Carrier ◽  
Plane Displacement

This paper investigates thermo-mechanical deformation and stresses of a flip-chip package (FCBGA) with and without underfill materials. Chip carrier is a 2-2-2 build-up substrate with 40 × 40 mm2 dimension; while bump material employs Sn/37Pb eutectic solder. Temperature-dependent warpage (out-of-plane displacement) of a FCBGA is characterized via shadow moire´ technique. Results of warpage measurement reveal that packages do not follow the same path during thermal loading/unloading cycle (20-220-20 °C) for both FCBGA with and without underfills. This implies that both solder and underfill exhibit inelastic material response. Therefore, it is a necessity to consider nonlinear constitutive response of packaging materials when designing flip-chip packages. It is observed that FCBGA with underfill exhibit more warpage than packages without underfill due to higher CTE mismatch between underfills and silicon dies. Aspect of package geometry such as die-to-substrate thickness ratio is found to play important role in reducing package stresses. Especially, thinner die provides more direct impact to die stresses reduction than thinner substrate does.

Vibration Induced Fatigue Life Estimation of Corner Leads of Peripheral Leaded Components

1996 ◽  
Vol 118 (4) ◽  
pp. 244-249 ◽  
Author(s):  
Sidharth ◽  
D. B. Barker
Keyword(s):  
Fatigue Life ◽  
Integrated Circuits ◽  
Analytical Techniques ◽  
Electronic Packages ◽  
Element Analysis ◽  
Thermally Induced ◽  
Operating Environments ◽  
Fatigue Life Estimation ◽  
Out Of Plane ◽  
Plane Displacement

The rapid advancement of integrated circuits and associated electronic technologies have placed increasing demands on electronic packaging and its material structures in terms of the reliability requirements. In addition to the thermally induced stresses, electronic packages often experience dynamic external loads during shipping, handling, and/or operation. This is especially important for automotive, military, and commercial avionics operating environments. These dynamic loads give rise to large dynamic stresses in the leads causing fatigue failures. For peripheral leaded packages the corner leads are the most highly stressed leads. This paper addresses the determination of the out-of-plane displacement of the corner leads of peripheral leaded components when the local peripheral leaded component/board assembly is subjected to bending moments in two directions. The solution is achieved by using a combination of Finite Element Analysis (FEA), Design of Experiments (DOE), and analytical techniques. The out-of-plane displacement can then be applied as a boundary condition on a local lead model to determine the stresses which in turn can be used to estimate the fatigue life.

Quality Inspection of Flip Chip Solder Bumps Using Integrated Analytical, Numerical, and Experimental Modal Analyses

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Jin Yang ◽  
I. Charles Ume
Keyword(s):  
Modal Analysis ◽  
Manufacturing Industry ◽  
Flip Chip ◽  
Solder Bump ◽  
Dynamic Responses ◽  
Mode Shapes ◽  
Inspection System ◽  
Solder Bumps ◽  
Out Of Plane ◽  
Plane Displacement

Solder bump inspection of surface mount packages has been a crucial process in the electronics manufacturing industry. A solder bump inspection system has been developed using laser ultrasound and interferometric techniques. In this research, modal analysis is important to correlate the defects with dynamic responses of packaged electronic devices under pulsed laser loading. The effect of solder bump defects on the mode frequencies and mode shapes is reported in this paper. The objective is to develop a modal analysis approach, which integrates analytical, numerical, and experimental methods. In particular, this paper discusses the analytical modeling, numerical modeling, and transient out-of-plane displacement measurements for a 6.35×6.35×0.6mm3 PB18 flip chip mounted on a FR4 board.

scholarly journals Moment and Stress Analysis Solutions of Clamped Rectangular Thick Plate

2020 ◽  
Vol 5 (4) ◽  
pp. 531-534 ◽  
Author(s):  
O. M. Ibearugbulem ◽  
Festus Chukwudi Onyeka
Keyword(s):  
Thick Plate ◽  
Plate Theory ◽  
Analytic Solutions ◽  
Numerical Comparison ◽  
Theory Analysis ◽  
Third Order ◽  
Total Potential ◽  
Out Of Plane ◽  
Plane Displacement

The bending solutions of rectangular thick plate with all four edges clamped (CCCC) were investigated in this study. The basic governing equations used for analysis are based on third-order shear deformation plate theory analysis under uniformly distributed load. Using a formulated total potential energy equation, the three coupled general governing differential equations for the determination of the out of plane displacement and shear deformations rotation along the direction of x and y coordinates were obtained. These equations as obtained are solved simultaneously after minimization to determine the coefficients of displacements of the plate and other the mentioned functions. By solving these equations, the analytic solutions of rectangular thick plate with all four edges clamped were derived. From the formulated expression, the formula for calculation of the maximum deflection, moment, stress and in-plane displacements were deduced. The proposed method obviates the need of shear correction factors, which is associated with Mindlin’s theory (FSDT) for the solution to the problem. Moreover, numerical comparison shows the correctness and accuracy of the results.

scholarly journals Sensor Integrated Load-Bearing Structures: Measuring Axis Extension with DIC-Based Transducers

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4104
Author(s):  
Nassr Al-Baradoni ◽  
Peter Groche
Keyword(s):  
Cost Effective ◽  
Image Correlation ◽  
Maximum Deviation ◽  
Single Image ◽  
Eccentric Load ◽  
Load Bearing ◽  
Out Of Plane ◽  
Axis Extension ◽  
Plane Displacement ◽  
Imaging Sensor

In this paper we present a novel, cost-effective camera-based multi-axis force/torque sensor concept for integration into metallic load-bearing structures. A two-part pattern consisting of a directly incident and mirrored light beam is projected onto the imaging sensor surface. This allows the capturing of 3D displacements, occurring due to structure deformation under load in a single image. The displacement of defined features in size and position can be accurately analyzed and determined through digital image correlation (DIC). Validation on a prototype shows good accuracy of the measurement and a unique identification of all in- and out-of-plane displacement components under multiaxial load. Measurements show a maximum deviation related to the maximum measured values between 2.5% and 4.8% for uniaxial loads ( and between 2.5% and 10.43% for combined bending, torsion and axial load. In the course of the investigations, the measurement inaccuracy was partly attributed to the joint used between the sensor parts and the structure as well as to eccentric load.

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