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Bow-Free Tri-Component Mechanically Pre-Stressed Failure-Oriented-Accelerated-Test (FOAT) Specimen
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 15, 2015 by SAE International in United States
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In some today's and future electronic and optoelectronic packaging systems (assemblies), including those intended for aerospace applications, the package (system's component containing active and passive devices and interconnects) is placed (sandwiched) between two substrates. In an approximate stress analysis these substrates could be considered, from the mechanical (physical) standpoint, identical. Such assemblies are certainly bow-free, provided that all the stresses are within the elastic range and remain elastic during testing and operation. Ability to remain bow-free is an important merit for many applications. This is particularly true in optical engineering, where there is always a need to maintain high coupling efficiency.
The level of thermal stresses in bow-free assemblies of the type in question could be, however, rather high. High thermal stresses are caused by the thermal contraction mismatch of the dissimilar materials of the assembly components and occur at low temperature conditions. These stresses include normal stresses acting in the component cross-sections and interfacial shearing and peeling stresses. The normal stresses in the component cross-sections determine the reliability of the component materials and the devices embedded into the inner component (package). The interfacial stresses affect the adhesive and cohesive strength of the assembly, i.e. its integrity.
It should be pointed out that although the assembly as a whole is bow-free, the peeling stresses in it, whether thermal or mechanical, are not necessarily low: the two outer components (substrates) might exhibit appreciable warpage with respect to the bow-free inner component (package).
While there is an incentive for using bow-free assemblies, there is also an incentive for narrowing the temperature range of the accelerated reliability testing: elevated temperature excursions might produce an undesirable shift in the modes and mechanisms of failure, i.e. lead to failures that will hardly occur in actual operation conditions. Failure oriented accelerated test (FOAT) specimens are particularly vulnerable, since the temperature range in these tests should be broad enough to lead to a failure, and, if a shift in the modes and mechanisms of failures takes place during significant temperature excursions, the physics of such failures might be quite different of those in actual operation conditions. Mechanical pre-stressing can be an effective means for narrowing the range of temperature excursions during accelerated testing and, owing to that, - for obtaining consistent and trustworthy information. If pre-stressing is considered, the ability to predict the thermo-mechanical stresses in the test specimen is certainly a must.
Accordingly, the objective of this analysis is to obtain simple, easy-to-use, physically meaningful and practically useful closed form solutions for the evaluation of stresses in a bow-free test specimen of the type in question. The emphasis is on the role of compliant attachments, if any, between the inner and the two outer components.
The developed model can be used at the design and accelerated test stages of the development of bow-free electronic and optoelectronic products. The compliant attachments, if any, could be particularly comprised of beamlike solder joint interconnections that, if properly designed, have a potential to relieve the thermal stresses to an extent that the low-cycle-fatigue state-of-stress is avoided.
CitationSuhir, E., Bensoussan, A., and Nicolics, J., "Bow-Free Tri-Component Mechanically Pre-Stressed Failure-Oriented-Accelerated-Test (FOAT) Specimen," SAE Technical Paper 2015-01-2551, 2015, https://doi.org/10.4271/2015-01-2551.
- Suhir E., “Stresses in Bi-Metal Thermostats”, ASME J. Appl. Mech.(JAM), Vol. 53, No. 3, Sept. 1986
- Suhir E., “Calculated Thermally Induced Stresses in Adhesively Bonded and Soldered Assemblies”, Int. Symp. on Hybrid Microelectronics, ISHM, Atlanta, Georgia, Oct. 1986
- Suhir E. “Die Attachment Design and Its Influence on Thermal Stresses in the Die and the Attachment”, 37th Electron. Comp. and Techn.Conf. (ECTC), 1987
- Suhir E., “An Approximate Analysis of Stresses in Multilayer Elastic Thin Films”, JAM, Vol. 55, No. 3, 1988
- Suhir E., “Interfacial Stresses in Bi-Metal Thermostats”, JAM., Vol. 56, No. 3, 1989
- Kiang B., Wittmershaus J., Kar R. and Sugai N., “Package Warpage Evaluation for Multi-Layer Molded PQFP”, 11th IEEE/CHMT Int. Electr. Manufact.Techn. Symp. (IEMT), 89, 1991
- Suhir E. and Manzione L. T., “Predicted Bow of Plastic Packages Due to the Non-uniform Through-Thickness Distribution of Temperature”, ASME J. Electr. Pack. (JEP), Vol. 114, No. 3, 1992
- Suhir E., “Predicted Bow of Plastic Packages of Integrated Circuit (IC) Devices”, J. Reinf. Plastics and Comp., vol. 12, Sept. 1993
- Nguyen L.T., Chen K.L., and Lee, P.,. “Leadframe Designs for Minimum Molding-Induced Warpage”, 44th IEEE ECTC, 1994
- Kelly G., Lyden C., Lawton W., Barrett J., Saboui A., Lamourelle F., and Exposito J., “Accurate Prediction of PQFP Warpage”, 44th IEEE ECTC, 1994
- Kelly G., Lyden C., Lawton W., Barrett J., Saboui A., Pape H. and Peters H., “The Importance of Molding Compound Chemical Shrinkage in the Stress and Warpage Analysis of PQFPs”, 45th IEEE ECTC, 1995
- Yip L. and Hamzehdoost A., “Package Warpage Evaluation for High Performance PQFP”, 45th IEEE ECTC, 1995
- Liang D., “Warpage Study of Glob Top Cavity-UP EPBGA Packages,” 46th IEEE ECTC, 1996
- Verma K., Columbus D. and Han B. “Development of Real Time/Variable Sensitivity Warpage Measurement Technique and Its Application to Plastic Ball Grid Array Package”, IEEE CPMT Trans. on Electron. Packag. Manuf., Vol. 22, No. 1, 1999
- Suhir E., “Predicted Stresses in, and the Bow of, a Circular Substrate/Thin-Film System Subjected to the Change in Temperature”, J. Appl. Physics (JAP), vol.88, No.5, 2000
- Yang S.-Y., Jiang S.-C., and Lu W.-S., “Ribbed Package Geometry for Reducing Thermal Warpage and Wire Sweep During PBGA Encapsulation”, IEEE CPMT Transactions, Vol. 23, No. 4, Dec. 2000
- Ko M., Shin D., Lim I., Park Y., “Warpage Behavior of LOCTSOP Memory Package”, Journal of Materials Science: Materials in Electronics, vol.12, issue 2, Feb. 2001
- Hai D., Powell R. E., Hanna C. R. and Ume I. C. “Warpage Measurement Comparison Using Shadow Moiré and Projection Moiré Methods”, IEEE CPMT Transactions, Vol. 25, No. 4, 2002
- Tsai M. Y., Hsu C. H. and Han C. N. “A Note on Suhir's Solution of Thermal Stresses for a Die-Substrate Assembly”, JEP, Vol. 126, No. 1, 2004
- Tsai M.Y., Wang C. T., and Hsu C. H., “The Effect of Epoxy Molding Compound on Thermal/Residual Deformations and Stresses in IC Packages During Manufacturing Process,” IEEE CPMT Transactions, Vol. 29, No. 3, Sept. 2006
- Irving K., Chien Y., Zhang J., Rector L. and Todd M., “Low Warpage Molding Compound Development for Array Packages”,. 1st Electronics System Integration Technology Conference (ESTC), 2, 2006
- Lee C. K., Loh W. K., Ong K. E. and Chin I. “Study of Dynamic Warpage of Flip Chip Packages Under Temperature Reflow”, IEMT, 2006
- Tsai M. Y.,, Wu, C. Y., Huang, C. Y., Cheng, W. C., and Yang, S. S., “Study of Some Parameters Effect on Warpage and Bump-Joint Stresses of COG Packages,” IEEE CPMT Transactions on Advanced Packaging, Vol. 29, No.3, 2006
- Tsai M.Y., Wang, C. T. and Hsu, C. H., “The Effect of Epoxy Molding Compound on Thermal/Residual Deformations and Stresses in IC Packages During Manufacturing Process,” IEEE CPMT Transactions, Vol. 29, No. 3, Sept. 2006
- Tsai M. Y., Huang, C. Y., Chiang, C. Y., Chen, W. C., and Yang, S. S. “Experimental and Numerical Studies of Warpages of ACF-bonded COG Packages Induced from Manufacturing and Thermal Cycling,” IEEE CPMT Transactions, Vol. 30, No. 4, Nov. 2007
- Tsai M. Y., Huang, C. Y., Chiang, C. Y., Chen, W. C., and Yang, S. S. “Hygro-Thermal Warpages of COG Package with Non-Conductive Paste Adhesive,” IEEE CPMT Transactions, Vol. 30, No. 3, Sept. 2007
- Tsai M. Y., Chen Y. C. and Lee S. W. Ricky “Correlation Between Measurement and Simulation of Thermal Warpage in PBGA with Consideration of Molding Compound Residual Strain”, IEEE CPMT Transactions, Vol. 31, No. 3, 2008
- Tsai, M. Y., Chen, Y. C., and Lee, S. W. Ricky, “Correlation Between Measurement and Simulation of Thermal Warpage in PBGA with Consideration of Molding Compound Residual Strain,” IEEE CPMT Transactions, Vol. 31, No. 3, Sept. 2008
- JEDEC Standard, “Package Warpage Measurement of Surface-Mount Integrated Circuits at Elevated Temperature”, JESD22-B112A, JEDEC SOLID STATE TECHNOLOGY ASSOCIATION, Revision of JESD22-B112, May 2005, Published by JEDEC Solid State Technology Association 2009
- Huang C. Y., Li T. D. and Tsai M. Y., “Warpage Measurement and Design of BGA Package Under Thermal Loading,” IMPACT 2009, Taipei, Taiwan, 2009
- Tsai M.-Y.. Chang H.Y., and Pecht M., “Warpage Analysis of Flip-Chip PBGA Packages Subject to Thermal Loading”, IEEE Transactions on Device and Materials Reliability, vol.9, issue 3, 2009
- Huang P. S., Lin Y. H., Huang, C.Y. Tsai M.Y. Huang T. C. and Liao M.C., “Warpage and Curvature Determination of PCB with DIMM Socket During Reflow Process by Strain Gage Measurement,” IMPACT 2010, Taipei, Taiwan, 2010
- Song C. G. and Choa S.-H., “Numerical Study of Warpage and Stress for the Ultra Thin Package”, J. Microelectr. Packag. Soc., (IMAPS), 17(4), 49, 2010
- Tsai M.Y., Chiang C. Y. C., Huang Y., and Yang S.S., “Residual Strain Measurement of Thin-Layer Cured Adhesives and Their Effects on Warpage in Electronic Packaging,” IEEE CPMT Transactions, Vol. 33, No. 1, Mar. 2010
- Lin W. and Na J.H., “A Novel Method for Strip Level Warpage Simulation of PoP Package During Assembly Processes”, 60th IEEE ECTC 2010
- Suhir E. and Weld J., “Electronic Package with Reduced Bending Stress”, US Patent #5,627,407, 1997
- Suhir E., “Device and Method of Controlling the Bowing of a Soldered or Adhesively Bonded Assembly,” US Patent #6,239,382, 2001
- Suhir E., “Bow Free Adhesively Bonded Assemblies: Predicted Stresses”, Electrotechnik & Informationtechnik, 120 (6), June 2003
- Suhir E., “Adhesively Bonded Assemblies with Identical Nondeformable Adherends and Inhomogeneous Adhesive Layer: Predicted Thermal Stresses in the Adhesive”, J. Reinforced Plastics and Composites, vol.17, No.14, 1998
- Suhir E., “Adhesively Bonded Assemblies with Identical Nondeformable Adherends: Predicted Thermal Stresses in the Adhesive Layer”, Composite Interfaces, vol.6, No.2, 1999
- Suhir E., “Adhesively Bonded Assemblies with Identical Nondeformable Adherends and “Piecewise Continuous” Adhesive Layer: Predicted Thermal Stresses and Displacements in the Adhesive”, Int. J. Solids and Structures, vol.37, 2000
- Suhir E., Gu C., Cao L., “Predicted Thermal Stress in a Circular Adhesively Bonded Assembly with Identical Adherends”, ASME J. Appl. Mech, vol. 79, No.1, 2011
- Suhir E., “Failure-Oriented-Accelerated-Testing (FOAT) and Its Role in Making a Viable IC Package into a Reliable Product”, Circuits Assembly, July 2013
- Suhir E., Bensoussan A., Nicolics J., Bechou L., “Highly Accelerated Life Testing (HALT), Failure Oriented Accelerated Testing (FOAT), and Their Role in Making a Viable Device into a Reliable Product”, 2014 IEEE Aerospace Conference, Big Sky, Montana, March 2014
- Suhir E., “Analysis of a Pre-Stressed Bi-Material Accelerated Life Test (ALT) Specimen”, Zeitschrift fur Angewandte Mathematik und Mechanik (ZAMM), vol.91, No.5, 2011
- Suhir E. and Nicolics J., “Analysis of a Bow-Free Pre-Stressed Test Specimen”, ASME JAM, vol.81, No.11, 2014
- Suhir E., “Analysis of a Short Beam with Application to Solder Joints: Could Larger Stand-off Heights Relieve Stress?”, European Physical Journal, Applied Physics (EPJAP), in print
- Suhir E., “Structural Analysis of Microelectronic and Fiber Optic Systems”, Van-Nostrand, New York, 1991.