0
Launch Dynamics

Assessment of Need for Solder in Modeling Potted Electronics During Gun-Shot

[+] Author and Article Information
L. E. Reinhardt

e-mail: Lyonel.reinhardt@us.army.mil

J. D. Metz

RDAR-MEF-E,
Analysis and Evaluation Technology Division,
U.S. Army Armament Research Development and Engineering Center,
Picatinny Arsenal, NJ 07806

Manuscript received July 31, 2012; final manuscript received November 9, 2012; accepted manuscript posted January 9, 2013; published online April 19, 2013. Assoc. Editor: Bo S. G. Janzon.

J. Appl. Mech 80(3), 031502 (Apr 19, 2013) (7 pages) Paper No: JAM-12-1360; doi: 10.1115/1.4023336 History: Received July 31, 2012; Revised November 09, 2012; Accepted January 09, 2013

Smart projectiles use electronic components such as circuit boards with integrated circuits to control guidance and fusing operations. During gun-launch, the electronics are subjected to 3-dimensional g-forces as high as 15,000 G. The U.S. Army uses finite element analysis to simulate electronics with high-g, dynamic loads. Electronics are difficult to model due to the large variation in size, from large circuit boards, to very small solder joints and solder pads. This means that to accurately model such small features would require very large models that are computationally expensive to analyze; often beyond the capability of resources available. Therefore, small features such as solder joints are often not included in the finite element models to make the models computationally tractable. The question is: what is the effect on model accuracy without these small features in the model? The purpose of this paper is to evaluate the effect that solder joints and solder pads have on the accuracy of the structural analysis of electronic components mounted on circuit boards during gun shot. Finite element models of simplified circuit boards, chips, and potting were created to do the evaluation. Modal analysis and dynamic structural analysis using typical gun loads were done. Both potting at high temperature (soft) and potting at low temperature (stiff) were used in the dynamic analysis. In the modal analysis there was no potting. All of these models were run with and without solder. In all cases, the results differed between the models with solder and those without. In the models with potting, there was a difference in magnitude and stress distribution between the models with and without solder. This indicates that there is a significant reduction in accuracy when solder is not included in the model.

FIGURES IN THIS ARTICLE
<>
Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.

References

“Excalibur XM982 Precision Engagement Projectiles,” 2009, http://www.dote.osd.mil/pub/reports/FY2009/pdf/army/2009excalibur.pdf
Fan, X., Pei, M., and Bhatti, P. K., 2006, “Effect of Finite Element Modeling Techniques on Solder Joint Fatigue Life Prediction of Flip-Chip BGA Packages,” 56th Proceedings of theIEEE, Electronic Components and Technology Conference, San Diego, CA, May 30–June 2. [CrossRef]
Hong, B. Z., and Burrell, L. G., 1997, “Modeling Thermally Induced Viscoplastic Deformation and Low Cycle Fatigue of CBGA Solder Joints in a Surface Mount Package,” IEEE Trans. Compon., Packag., Manuf. Technol., Part A, 20(3), pp. 280–285. [CrossRef]
ABAQUS User Manual V6.11.1,” Dassault Systems, 2004–2011.
Lall, P., Gupte, S., Choudhary, P., and Suhling, J., 2007, “Solder Joint Reliability in Electronics Under Shock and Vibration Using Explicitly Finite-Element Submodeling,” IEEE Trans. Electron. Packag. Manuf., 30(1), pp. 74–83. [CrossRef]
Jianfei, L., 2010, “Dynamic Mechanical and Failure Properties of Solder Joints,” Ph.D. thesis, Department of Mechanical Engineering, National University of Singapore, Singapore.
Zhang, L., Sitaraman, R., Patwardhan, V., Nguyen, L., and Kelkar, N., 2003, “Solder Joint Reliability Model With Modified Darveaux's Equations for the Micro SMD Wafer Level-Chip Scale Package Family,” 53rd Proceedings of the Electronic Components and Technology Conference, New Orleans, LA, May 27–30, pp. 572–577.
Lin, Y. C., Chen, X., Liu, X., and Lu, G.-Q., 2005, “Effect of Substrate Flexibility on Solder Joint Reliability—Part II: Finite Element Modeling,” Microelectron. Reliab., 45, pp. 143–154. [CrossRef]
Duffek, D., 2004, “Effects of Combined Thermal and Mechanical Loading on the Fatigue of Solder Joints,” M.S. thesis, University of Notre Dame, Notre Dame, IN.
Adolf, D., Spangler, S., and Austin, K., 2011, “Packaging Strategies for Printed Circuit Board Components. Volume I: Materials and Thermal Stresses,” Sandia National Laboratories, Alburquerque, NM, Sandia Report No. SAND2011-4751.
Warner, M., Parry, J., Bailey, C., and Lu, H., 2004, “Solder Life Prediction in a Thermal Analysis Software Environment,” Proceedings of the 2004 International Society Conference on Thermal Phenomena, Itherm, Nevada, pp. 391–396.
Fan, X., Pei, M., and Pardeep, K. B., 2006, “Effect of Finite Element Modeling Techniques on Solder Joint Fatigue Life Prediction of Flip-Chip BGA Packages,” 2006 Electronic Components and Technology Conference, IEEE, San Diego, CA, May 30–June 2. [CrossRef]
Gupte, S., 2007, “Solder Joint Reliability in Electronics Under Shock and Vibration Using Explicit Finite-Element Sub-Modeling,” M.S. thesis, Auburn University, Auburn, AL.
Blattau, N., Gormally, P., Iannaccone, V., Harvilchuck, L., and Hillman, C., 2006, “Robustness of Surface Mount Multilayer Ceramic Capacitors Assembled With Pb-Free Solder,” CARTS 2006, 26th Capacitor and Resistor Technology Symposium, Orlando, FL, April 3–6, pp. 25–41.
Blattau, N., Barker, D., and Hillman, C., 2004, “Lead Free Solder and Flex Cracking Failure in Ceramic Capacitors,” 2004 Proceedings of the 24th Capacitor and Resistor Technology Symposium, San Antonio, TX, March 29–April 1.
Haynes, A., and Cordes, J. A., 2011, “Characterization of a Potting Material for Gun Launch,” 26th International Symposium on Ballistics, Miami, FL, September 12–16, Paper No. 12062, http://www.dtic.mil/ndia/2011ballistics/2011ballistics.html
Haynes, A. S. J., Cordes, J. A., and Krug, J., 2012, “Thermomechanical Impact of Polyurethane Potting on Gun Launched Electronics,” J. Eng., (in press).
Jeerfferie, A. R., Yuhazri, M. Y., Nooririnah, O., Haidir, M. M., Sihombing, H., Mohd Salleh, M. A., and Ibrahim, N. A., 2010, “Thermomechanical and Morphological Interelationship of Polypropylene-Mulitwalled Carbon Nanotubes (PP/MWCNTs) Nanocomposites,” Int. J. Basic Appl. Sci. IJBAS IJENS., 10(4), pp. 29–35.
Baylakoglu, I., Hillman, C., and Pecht, M., 2003, “Characterization of Some Commercial Thermally-Cured Potting Materials,” Proceedings of the International IEEE Conference on the Business of Electronic Product Reliability and Liability, Hong Kong.
Chao, N. H., Carlucci, D., Cordes, J. A., DeAngelis, M. E., and Lee, J., 2011, “The Use of Potting Materials for Electronic-Package Survivability in Smart Munitions,” ASME J. Electron. Packag., 133(4), p. 041003. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Model cross section

Grahic Jump Location
Fig. 2

Circuit board details

Grahic Jump Location
Fig. 3

Circuit board without solder

Grahic Jump Location
Fig. 4

Circuit board with solder

Grahic Jump Location
Fig. 5

Load location: loads are applied in three directions to the can bottom

Grahic Jump Location
Fig. 6

Load curves in three directions

Grahic Jump Location
Fig. 9

Von Mises stress of chips with and without solder; 233 K

Grahic Jump Location
Fig. 10

Displacement of chips and circuit board; 233 K

Grahic Jump Location
Fig. 11

Displacement of potting; 233 K

Grahic Jump Location
Fig. 12

Von Mises stress, case 3, 333 K, softer potting

Grahic Jump Location
Fig. 13

Von Mises stress of circuit board and chips, 333 K, softer potting

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In