Introduction of non-linear fracture mechanics in the modelling of a flip-chip component under drop impact

Abstract

Purpose This study aims to contribute to the numerical modelling of drop impact on a flip-chip component assembled on printed circuit boards using solder micro-bumps. This contribution is based on the introduction of non-linear fracture mechanics in the numerical approach. Design/methodology/approach The integration of non-linear fracture mechanics into the numerical approach requires the proposal and validation of several simplifying assumptions. Initially, a dynamic 3D model was simplified to a dynamic 2D model. Subsequently, the dynamic 2D model is replaced with an equivalent static 2D model. The equivalent static 2D model was used to perform calculations considering the non-linear fracture mechanics. A crack was modelled in the critical bump. The J-integral was used as a comparative parameter to study the effects of crack length, crack position and chip thickness on the fracture toughness of the solder bump. Findings The different simplifying assumptions were validated by comparing the results obtained by the various models. Numerical results showed a high risk of failure at the critical solder bump in a zone close to the intermetallic layer. The obtained results were in agreement with the post-test observations using the “Dye and Pry” methods. Originality/value The originality of this study lies in the introduction of non-linear fracture mechanics to model the mechanical response of solder bumps during drop impact. This study led to some interesting conclusions, highlighting the advantage of introducing non-linear fracture mechanics into the numerical simulations of microelectronic components during a drop impact.

Simplifying finite elements analysis of four-point bending tests for flip chip microcomponents

“…Testing approaches to estimating reliability require considerable time for sample preparation, which increases costs and lengthens the time taken to obtain responses. Numerical simulations using finite elements are increasingly used to predict numerically the reliability of electronic microcomponents (Belhenini et al, 2023;Hamdani et al, 2022;Gharaibeh et al, 2019). In numerical approaches, equivalent stresses and plastic strains are commonly used as reliability criteria.…”