Session: 10-01 Interactive Presentations

Paper Number: 99299

99299 - Evolution of High Strain Rate Mechanical Properties of SAC+Bi Solders After 120 Days of 50°c Isothermal Aging 

Various electronic devices may be subjected to continuous operation at high and low surrounding temperatures, as well as high strain-rate loads, in aerospace, military, and automotive applications. Prior to deployment, these parts can also be housed in non-climate-controlled enclosures. Previous studies have demonstrated that after a lengthy period of storage, the material characteristics of undoped SAC alloys change, even at mild temperatures. To decrease the aging effects, a number of dopants have been added to SAC alloy compositions. Two doped SAC solders, QSAC10 and QSAC20, were subjected to high strain rate testing in this investigation after being stored at 50°C for 120 days. The samples ranged from those that had not been aged to those that had been aged for 120 days and had been subjected to uniaxial tensile testing. The experiment's high and low operating temperatures ranged from -65°C to 200°C. The constants for the Anand Visco-Plasticity model were then computed using the experimental material data, and the model predictions for the uniaxial tensile test were compared to the experimental data. To simulate the drop events, the material constitutive behavior was implemented in a finite element framework using the Anand constitutive model. The plastic work per shock event, which is a measure of the damage progression in the solder interconnects, has also been determined. Finally, the constitutive model was applied to simulate a ball-grid array package shock event on a printed circuit board assembly. 

Presenting Author: Mrinmoy Saha Auburn University