Abstract
Compliant leads, introduced in surface-mounted circuit card systems, help reduce stress arising in the interconnecting elements due to thermal mismatch between the module and card. The peripheral SMT joints, however, are also subject to mechanical stress owing to handling, vibration, and shock. The flexural and torsional deformations (called “flexing” of the card in general) lead to a maximum tie force at the module corners; this force has a predominant component in the z-direction, as discussed in Chapter 3. While the axial lead stretch is contributed overwhelmingly by bending action along its curved length, a simplified modeling of leads as axial springs with a spring constant K may account for this flexural deformation; K values have also been measured for various leads (see Table 3.5).
Chapter PDF
References
Engel, P.A., Caletka, D.V., and Palmer, M.R. (1991), “Stiffness and Fatigue Study for Surface Mounted Module/Lead/Card Systems,” ASME J. Elec. Packag. 113(2), 129–137.
Suhir, E. (1988), “On a Paradoxical Phenomenon Related to Beams on Elastic Foundation,” J. Appl. Mech., 55(4), 818–821.
Engel, P.A. (1990), “Structural Analysis for Circuit Card Systems Subjected to Bending,” ASME J. Elec. Packag. 112(1), 2–10.
Chang, T.S., and Magrab, E.B. (1991), “An Improved Procedure for the Determination of the Elastic Constants of Component-Lead-Board Assemblies,” ASME J. Elec. Packag. 113(4), 427–430.
Author information
Authors and Affiliations
Rights and permissions
Copyright information
© 1993 Springer Science+Business Media New York
About this chapter
Cite this chapter
Engel, P.A. (1993). Compliant Leaded Systems: The Local Assembly. In: Structural Analysis of Printed Circuit Board Systems. Mechanical Engineering Series. Springer, New York, NY. https://doi.org/10.1007/978-1-4612-0915-7_7
Download citation
DOI: https://doi.org/10.1007/978-1-4612-0915-7_7
Publisher Name: Springer, New York, NY
Print ISBN: 978-1-4612-6945-8
Online ISBN: 978-1-4612-0915-7
eBook Packages: Springer Book Archive