AN ANALYTICAL APPROACH TO BGA COMPONENTS IN RANDOM VIBRATION ENVIRONMENTS Milan J Lucic, MANE 6980 Engineering Project

Methodology and Approach  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  PATRAN static inertial analysis to solve for stresses of BGA’s  Greatly reduce analysis time!  Using hand calculations, solve for the Miner’s Damage Index of electrical components and the high cycle fatigue of the BGA components.

Expected Outcomes  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)  Generate plots of high cycle fatigue life for lead vs. lead-free BGA components

Project Progress-FEA Model BGA Model ACTEL 484 PGA Pin Grid Snapshot Solder Ball and Solder Joint FEM

Project Progress-FEA Model Boundary Conditions:

Finite Element Analysis-Hand Calcs Plate Stiffness Factor First Mode Natural Frequency G RMS Single Amplitude Displacement Curve C Calculated Results: f n = Hz Z RMS =.0018 inches

Finite Element Analysis-Normal Modes Mode 1: Hz Mode 2: Hz Mode 3: Hz

Finite Element Analysis-Random Input Curve Frequency Response Mode 1Mode 3 Mode 2 RMS Displacement

Finite Element Analysis-Optimization Optimized Size: 570 Elements (Quad 20)

Project Schedule  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: Inertial Analysis  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