Finite Elements for Electromigration Analysis

Implementation of General Coupling Model of Electromigration in ANSYS

“…Although this example provides a complete process in modeling electromigration in solder, three errors pointed previously in Example 1 are also presented in this example. [27] The developers at ANSYS published a paper [27] for electromigration modeling, which provides additional information of the theory and the implementation in ANSYS using R18.1. For electromigration, the total vacancy flux is written as follows,…”

“…To illustrate the ANSYS's capabilities for modeling the distributions and evolutions of vacancy concentration and stress, a 1-D model of electromigration in pure metal line was performed in this paper. As shown in the paper [27], the coefficient of diffusion strain is set as β=-0.05 to obtain a "reasonable" hydrostatic stress value at steady state (~350 MPa), but this value of β is given without any reference and basis. Furthermore, by using the vacancy diffusivity Dv=3×10 -16 m 2 /s, the predicted time to reach steady state is "comparable" with the experimental results.…”