Evaluation of Package Stress during Temperature Cycling using Metal Deformation Measurement and FEM Simulation

2006 ◽  
Author(s):  
J. Höglauer
Keyword(s):  
Fem Simulation ◽  
Temperature Cycling ◽  
Deformation Measurement ◽  
Metal Deformation

Package-to-Board Attach Reliability — Methodology and Case Study on OMPAC Package

1998 ◽  
Vol 120 (3) ◽  
pp. 290-295 ◽  
Author(s):  
B. Nagaraj ◽  
M. Mahalingam
Keyword(s):  
Failure Criterion ◽  
Fem Simulation ◽  
Strain Range ◽  
Temperature Cycling ◽  
Experimental Results ◽  
Temperature Cycle ◽  
Temperature Cycles ◽  
Permanent Strain ◽  
Plastic Ball ◽  
Plastic Creep

Over molded pad array carrier (OMPAC), also called plastic Ball Grid Array (pBGA) package family offers increased I/O density at the board level; further, package size and thickness are reduced in comparison to other competing package types leading to many product applications. The OMPAC package is investigated for solder pad interconnect reliability. Elastic and inelastic finite element method (FEM) simulations are employed with experimental temperature cycling data. Linear elastic analyses are performed for various package parameters that influence the stress distribution in the solder pad interconnect for temperature loading. The package parameters considered are (a) ratio of thickness of die to substrate (tdie/tsub.), (b) ratio of width of die to substrate (wdie/wsub.), and (c) ratio of height to diameter of the solder pad interconnect ((h/d)pad). The results are evaluated based on the maximum Tresca (maximum shear stress) failure criterion. The key parameter is (h/d)pad ratio. As this ratio increases, the maximum Tresca failure criterion decreases. The performance of the solder pads are evaluated based on the maximum total permanent strain (plastic + creep) range per temperature cycle. FEM simulation was performed up to eight consecutive temperature cycles. The permanent strain (plastic + creep) range were calculated for each temperature cycle and observed that after a few temperature cycles the strain ranges stabilize. The maximum stabilized total permanent strain range is in the inner solder pad and is equal to 0.005. This maximum total strain range in the solder pad per temperature cycle loading can be used to estimate the life time of the solder pads. The FEM simulation results are correlated with the experimental data. Both the simulation and the experimental results are indicate that the outer pads are not as critical as the inner or the middle pads. The experimental results indicate that there is slightly larger probability for the middle pads to fail before the inner pads. However, the simulation data indicate that the inner pads are more critical than the middle pads. We believe that this small discrepancy in simulation result is due to the actual temperature variation on the package not being included in the present analysis.

scholarly journals Capabilities of Using Fem in Sheet-Metal Forming

2016 ◽  
Vol 61 (2) ◽  
pp. 947-951
Author(s):  
S. Korga ◽  
A. Duda ◽  
Z. Ciekanowski
Keyword(s):  
Research Methods ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Fem Simulation ◽  
Fem Analysis ◽  
Operating Conditions ◽  
Deformation Analysis ◽  
Plastic Processing ◽  
Metal Deformation

Abstract The aim of this study was to determine and select boundary conditions of modeling and FEM simulation for plastic processing on the example of sheet-metal forming. For sheet-metal deformation analysis, Deform 3D has been used. The study presents research methods for real and virtual conditions. There are also described common features and these differentiating obtained results. Research of conducted process of sheet-metal forming allows to determine the effectiveness of computer research methods. The finite-element method can be used as an effective tool for the study of plastic processing phenomena considering various operating conditions of individual elements provided the appropriate tools for FEM analysis.

Numerical Simulation on Performance Characteristic of Novel Fomichev Plug Used in Cone-Roll Piercer

2010 ◽  
Vol 154-155 ◽  
pp. 91-96
Author(s):  
Sheng Zhi Li ◽  
Lan Wei Hu ◽  
Wen Hua Meng ◽  
Bo Ding ◽  
Jian Min Zheng ◽  
...  
Keyword(s):  
Performance Characteristic ◽  
Fem Simulation ◽  
The Novel ◽  
High Alloy ◽  
Tube Billet ◽  
Cone Type ◽  
Feed Angle ◽  
Metal Deformation ◽  
Toe Angle ◽  
Unit Reduction

The Fomichev plug is of characteristic producing equal unit-reduction of wall thickness along its perforation section during seamless tube piercing. This paper introduces the design of a novel Fomichev plug based upon the analysis of roll opening, taking into account for both feed angle and toe angle of a cone type piercer, then presents a 3-D coupled thermo-mechanical simulation of the novel Fomichev Plug’s performance characteristic during cone-roll piercing process, with the aid of FE code MSC.SuperForm. In comparison with conventional plugs, as FEM simulation result shows that the new plug makes the metal deformation distribute uniformly along its perforation section, which brings about well-distributed plug wear. The novel Fomichev plug is able to decrease the slip between the roll and workpiece and avoid rolling block owing to its smaller plug force, which can increase piercing efficiency so, moreover, analyzing stress distribution, it’s more suitable for metal deformation with fewer defects in tube piercing, makes resistance to metal elongation smaller, reduces wedge cleaving to tube billet, and prevents lamination defects during piercing high-alloy billet.

Simulation of vibration piercing of pipe blank at press

2020 ◽  
Vol 76 (11) ◽  
pp. 1128-1138
Author(s):  
S. R. Rakhmanov
Keyword(s):  
High Frequency ◽  
Deformation Zone ◽  
Pipe Blank ◽  
Equipment Operation ◽  
Metal Deformation ◽  
Technological Tool ◽  
High Frequency Vibrations ◽  
Pipe Blanks ◽  
Wave Phenomena

In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.

Free-surface deformation measurement

1997 ◽  
Author(s):  
H. Stahl ◽  
Kevin Stultz ◽  
H. Stahl ◽  
Kevin Stultz
Keyword(s):  
Free Surface ◽  
Surface Deformation ◽  
Deformation Measurement ◽  
Free Surface Deformation

An Advanced Reliability Improvement and Failure Analysis Approach to Thermal Stress Issues in IC Packages

2009 ◽  
Author(s):  
Michael Hertl ◽  
Diane Weidmann ◽  
Alex Ngai
Keyword(s):  
Thermal Stress ◽  
Failure Analysis ◽  
Deformation Measurement ◽  
Stress Conditions ◽  
Analysis Approach ◽  
New Approach ◽  
Reliability Improvement

Abstract A new approach to reliability improvement and failure analysis on ICs is introduced, involving a specifically developed tool for Topography and Deformation Measurement (TDM) under thermal stress conditions. Applications are presented including delamination risk or bad solderability assessment on BGAs during JEDEC type reflow cycles.

Intermittent Failures in High Pin Count Packaging

2006 ◽  
Author(s):  
Ramesh Varma ◽  
Richard Brooks ◽  
Ronald Twist ◽  
James Arnold ◽  
Cleston Messick
Keyword(s):  
Failure Analysis ◽  
Shape Analysis ◽  
State Of The Art ◽  
Process Variation ◽  
High Reliability ◽  
Temperature Cycling ◽  
Assembly Process ◽  
System Failures ◽  
Industrial Grade ◽  
Corrective Actions

Abstract In a prequalification effort to evaluate the assembly process for the industrial grade high pin count devices for use in a high reliability application, one device exhibited characteristics that, without corrective actions and/or extensive screening, may lead to intermittent system failures and unacceptable reliability. Five methodologies confirmed this conclusion: (1) low post-decapsulation wire pull results; (2) bond shape analysis showed process variation; (3) Failure Analysis (FA) using state of the art equipment determined the root causes and verified the low wire pull results; (4) temperature cycling parts while monitoring, showed intermittent failures, and (5) parts tested from other vendors using the same techniques passed all limits.

THREE DIMENSIONAL FEM SIMULATION OF TITANIUM HOLLOW MONOLITHIC STRUCTURE PROCESS BASED ON VISCO--PLASTIC CONSTITUTIVE

2010 ◽  
Vol 46 (4) ◽  
pp. 396-403
Author(s):  
Bing ZHAO ◽  
Zhiqiang LI ◽  
Xiuquan HAN ◽  
Jinhua LIAO ◽  
Hongliang HOU ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Fem Simulation ◽  
Monolithic Structure
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