Thermomechanical behavior of micron scale solder joints under dynamic loads
نویسندگان
چکیده
Recent trends in reliability and fatigue life analysis of electronic devices have involved developing structural integrity models for predicting the operating lifetime under vibratory and thermal environmental exposure. Solder joint reliability is the most critical issue for the structural integrity of surface mounted electronics. Extensive research has been done on thermal behavior of solder joints, however, dynamic loading eects to solder joint fatigue life have not been thoroughly investigated. The physics of solder joint failure under vibration is still not very clear. This paper presents a test program which was performed to study inelastic behavior of solder joints of BGA packages. A concurrent loading unit is used which consists of a thermal environmental chamber and an electrodynamic shaker. Laser Moir e Interferometry was used to measure the whole deformation ®eld of the prepared specimen surface. The corresponding inelastic strain ®eld is then calculated. It is found that at elevated temperature, vibration and shock can cause the accumulation of inelastic strains and damage in solder joints. In this paper, contrary to the popular belief that all vibration-induced strains are elastic, it is shown that vibration can cause signi®cant inelastic strains. Ó 2000 Elsevier Science Ltd. All rights reserved.
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