AN ANALYTICAL APPROACH
TO BGA COMPONENTS IN
RANDOM VIBRATION
ENVIRONMENTS
Milan J Lucic, MANE 6980 Engineering Project
Project Overview
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BGA components are integral to the design of
advanced electronic systems like your cell phone, or
computer
Aerospace electronic controllers use BGA
components for processors or programmable gate
arrays
Reliability of these components greatly reduced by
mechanical vibration environments in Aircraft
Green Compliance (ROHS) driving electronic
components to use lead free solder and components
Problem Statement
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Goal is to study the stress and high cycle fatigue of
BGA components on card rack style circuit boards
 Random
vibration from RTCA DO-160F for fixed wing
aircraft
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Taking in account of several variables:
 BGA
position on board
 Lead vs. Lead-free solder (also lead free components)
 Random vibration level
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Component will be modeled after the ACTEL 484
PBGA commonly used in the aerospace industry
Methodology and Approach
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Accurately model the ACTEL 484 PBGA with 3-D hex
elements (balls and solder joint), and 2-D Shell elements
(PCB and component body)
Using NX7.5 Advanced simulation for Pre-Processing
and MSC PATRAN/MD NASTRAN as the post processor
and solver
PATRAN Random utility to solve for frequency response
(Mode Shapes), displacements, and RMS stresses
Using hand calculations, solve for the Miner’s Damage
Index of electrical components and the high cycle
fatigue of the BGA components.
Expected Outcomes
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To develop a better understanding of lead vs. lead
free BGA components used in common Aerospace
environments
Correlate data with actual industry test data to
refine future models
 Greatly
reduce risks early in the design phase
 Eliminate the need for development testing of BGA
components (expensive and time consuming)
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Generate plots of high cycle fatigue life for lead
vs. lead-free BGA components
Project Progress-FEA Model
Pin Grid
Snapshot
BGA Model
ACTEL 484 PGA
Solder Ball and
Solder Joint FEM
Project Progress-FEA Model
Lower Left Corner
Center Left Side
Center Position
Project Schedule
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Week 1: Develop Project Definition
Week 2: Preliminary Project Proposal
Week 3: Project Proposal
Week 4: FEA Model Development/Research
Week 5: Random Analysis/Model Refinement
Week 6: Random Analysis/Model Optimization
Week 7: Random Analysis/Model Optimization, First Progress Report
Week 8: MDI Calculations/Random Analysis
Week 9: Business Trip, out of the country.
Week 10: Post Processing, Second Progress Report
Week 11: Post Processing (extra time for model refinement)
Week 12: Final Report Draft
Week 13: Final Report Draft
Week 14: Final Report