PWB Warpage Analysis and Verification using an AP210 Standards-Based Engineering Framework and Shadow Moiré

1. AkroMetrix EuroSimE 2004 www.eurosime.com  Brussels, Belgium  May 10-12, 2004 PWB Warpage Analysis and Verification using an AP210 Standards-Based Engineering Framework and Shadow Moiré Dirk Zwemer1, Manas Bajaj2, Russell Peak2, Thomas Thurman3, Kevin Brady4, Sean McCarron1, Alex Spradling1, Michael Dickerson5, Lothar Klein6, Giedrius Liutkis6, and John Messina4 1. AkroMetrix LLC 2. Georgia Institute of Technology 3. Rockwell Collins, Inc. 4. National Institute of Standards and Technology 5. InterCAX, LLC 6. LKSoftWare Gmbh. Web version from http://eislab.gatech.edu/pubs/conferences/2004-eurosime-zwemer/ as of 2004-10-14 © All Rights Reserved. Permission to reproduce and distribute without changes for non-commercial purposes (including internal corporate usage) is hereby granted provided this notice and a proper citation are included.

2. Warpage – Impact and Trends Impact • Low Manufacturing Yield • High Rework of Interconnects • Low Reliability • More Severe with Higher Temperatures, Finer Pitch Trends OEMs Enforcing New Warpage Specifications on Suppliers. • Temperature-Dependent Warpage • Local and Global Warpage

3. Contents • Design-Analysis Interface within a Multi-Representation Engineering Framework • Experimental Verification using Temperature-Dependent Shadow Moiré • Initial Results and Future Development

4. Tree Structure of Multi-Representation Engineering Framework MPM Bare PWB Manufacturing Product Model APM Electrical APM Mechanical APM Manufacturability Analyzable Product Model Context-Based Analysis Model CBAM Warpage CBAM PTH Fatigue ABB Layered Shell Effective Materials Properties Analysis Building Blocks Solution Method Model SMM Finite Element

5. AP210 Standards-based Engineering Framework for Warpage Simulation Solder Component T body Joint Component 0 1 body body Solder Joint 4 3 body PWB 2 Printed Wiring Board (PWB) Manufacturing Product Model (STEP AP210-based) Analyzable Product Model Context-Based Analysis Model APM Analysis Building Block Printed Wiring Assembly (PWA) Solution Method Model CBAM ABB SMM F APM ABB Y ABB SMM Solution Tools (ANSYS, …)

6. Manufacturing Product Model (MPM) in anAP210 Standards-Based Engineering Framework Electrical CAD Tools Systems Engineering Tools Eagle Doors Traditional Tools - Eurostep AP233 Demonstrator - XaiTools AP233 MentorGraphics Slate AP210 interface • Manufacturing Product Model • Components • STEP AP210 XaiToolsPWA-B LKSoft, … STEP-Book AP210, SDAI-Edit, STI AP210 Viewer, ... XaiToolsPWA-B pgpdm LKSoft, … Gap-Filling Tools PWB Stackup Tool, … Core PDM Tool Instance Browser/Editor

7. AP210-based Manufacturing Product Model (MPM)cable_db example 2D PCB view and 3D Assembly view As viewed in LKSoft AP210 STEP-Book

8. Analyzable Product Model (APM)Warpage Analyzable View of PWB Footprint occurrence This comprises of four lands, in this case. The component sits atop the lands. Mechanical (Tooling / Drilling) Hole M150P2P11184 via Complete trace curve not shown M150P1P21184 Circuit Traces land PCB outline Comprised of straight lines and arcs (primitive level) plated through hole • 2D geometric structure • Orientation of each layer and associated features • Layer thickness and material properties 1 Oz. Cu 3 x 1080 2 Oz. Cu 1 Oz. Cu 2 x 2116 1 Oz. Cu 2 Oz. Cu 3 x 1080 1 Oz. Cu

9. Setting up context for warpage analysisAPM and ABB Creation … thickness length Side view of the PCB with “effective” grid elements across the stratums width CBAM ABB Model MPM / APM Single Layer View … Top view of “effective” grid elements in top layer of the PCB Effective Material Property Computation • Given: • Thermal loading profile • Boundary Conditions (mostly displacement) • Idealize PWB stackup as a layered shell Grid (Sieve) Size • CBAM attributes • Thermal loading profile • Boundary Conditions (mostly displacement) • Idealize PWB stackup as a layered shell

10. Stage 1: Chopping the bare PWBCreating the ABB model In this scenario, the plated through holes and vias are neglected (for simplicity). Only the mechanical tooling holes are accounted for. Case 3 Case 1 M rows … … … Case 2 N columns Case 1 Board Edge Scenario 1 At the end of stage 1, an M X N grid of shapes (comprised of arcs and lines at the primitive level) would be available. Operation during this stage is common across all stratums (as it deals with board outlines and tooling holes only – vias are disregarded) Board Edge Scenario 2 Case 2 Tooling Hole Scenario 1 Case 3

11. Stage 2: Computing metallization ratio Creating the ABB Model … thickness Side view of the PWB with “effective” grid elements across the stratums Consider a snapshot of metallization (traces and lands on stratum K) 1 <= I <= M 1 <= J <= N 1 <= K <= P … Cell IJ on stratum K has effective material properties IJK I … … … J Percentage metallization in the IJth cell of stratum K is of interest. Let this percentage be  Effective material property IJK for cell IJ on stratum K is then computed as: (1) IJK = ( / 100 ) * metal + ( 1 -  / 100) * airfor copper layers (2) IJK = dielectricfor dielectric layers air and hence the second term can be neglected in (1) above For the case of warpage,  is: -- Co-efficient of thermal expansion -- Young’s modulus of elasticity At the end of Stage 2, we have the effective material properties for each cell (MN cells) in each stratum (P stratums)

12. View of Analysis Building Block systemChopped (e.g. 4X4 grid) PWB Material properties

13. View of Analysis Building Block systemPWB Stackup Material properties

14. View of Solution Method ModelLayered shell mesh Geometric constraints Currently this model is tool-specific (ANSYS). Future possibility of AP209-based implementation exists. all 6 degrees of freedom locked at midpoint – boundary condition

15. Contents • Design-Analysis Interface within a Multi-Representation Engineering Framework • Experimental Verification using Temperature-Dependent Shadow Moiré • Initial Results and Future Development >>

16. Principles of Shadow Moiré Video Camera White Light In Diffusely Scattered Light Out Grating Shadow Grating Sample Example Fringe Intensity Images

17. Shadow Moiré Verification - TherMoiré® • Specifications • Sample Size: up to 400 x 400 mm • Vertical Resolution: ± 1 µm • Lateral Resolution: 640 x 480 pixels • Temperature Range: -55 C to 300 C (continuous), 350 C peak • Time per Measurement: 1 second (data acquisition), 2-10 seconds total Specifications · · · · · · · · ·

18. Shadow Moiré Data Design 1 High Resolution Shadow Moiré Phase Image Design 1 Video Image

19. 25 C Absolute Coplanarity = 261 mils 150 C Absolute Coplanarity = 234 mils Coplanarity = 25.4 mils 150 C relative to 25 C Coplanarity = 7.4 mils

20. -50 C

21. -25 C

22. 0 C

23. 25 C

24. 50 C

25. 75 C

26. 100 C

27. 125 C

28. 150 C

29. Future Developments Current Status • Generated Warpage Analysis Model from PWB Design Data using AP210-based Engineering Framework • Compared Results with Temperature-Dependent Shadow Moiré Experiments Future Developments (Analysis) • Level of Idealization – Grid Dimensions, Vias,… • Controlled Meshing (non-tool specific) • Display Options Future Developments (Validation) • Initial Conditions and Panelization • Boundary Conditions and Reference Plane • Temperature Uniformity and Sample Variation

30. Acknowledgements • PDES Inc.Electromechanical Pilot team • Greg Smith (Boeing) • Craig Lanning (Northrup Grumman) • Steve Waterbury (NASA) • Georgia Institute of Technology • Robert Fulton • Injoong Kim • Miyako Wilson • LKSoftWare Gmbh • Viktoras Kovaliovas • Kasparus Rudokas • Tomas Baltramaitas • Rockwell Collins, Inc. • Michael J. Benda • David D. Sullivan • William W. Bauer • Mark H. Carlson • Floyd D. Fischer * Certain commercial equipment, instruments, or materials are identified in this paper in order to specify the experimental procedure adequatelySuch identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the materials or equipment identified are necessarily the best available for the purpose.