Title: Damage mechanics of solder joints – viscoplasticity, implementation, simulation, and verification

Authors: Zhengfang Qian

Addresses: Physical and Digital Realization Center, Motorola Labs 1303 E Algonquin Rd, Schaumburg, IL 60196, USA

Abstract: This paper presents a damage mechanics methodology and its successful implementation for the progressive damage of solder joints widely used for electronic packages, enabling robust design, virtual qualification, and predictive reliability of components and assembly processes of electronic products. A unified viscoplastic constitutive framework with damage evolution and failure criteria has been developed and implemented into a commercially available tool to model time-rate-temperature dependent nonlinear properties of solder materials. As primary failure mode of solder joints, cracks on a solder joint can be automatically initiated and propagated by damage evolution with failure criteria under various loading conditions. Dynamic failure processes of solder joints of an electronic component assembled on PCB have been demonstrated for real-world case study under mechanical and thermal cyclic loadings in three-dimensional cases. The characteristics of crack initiation and propagation have been well verified by microscopic analyses of the failed components collected from the field.

Keywords: damage mechanics; solder joints; crack initiation; crack propagation; reliability; constitutive modelling; viscoplasticity; return mapping; algorithm implementation; electronic packaging; solder joint failure; PCB assembly.

DOI: 10.1504/IJMSI.2008.018901

International Journal of Materials and Structural Integrity, 2008 Vol.2 No.1/2, pp.64 - 92

Available online: 21 Jun 2008 *

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