FEM Analysis of Moisture Distribution in Stacked Die Package

Stacked Die Packaging technology is the key technique to meet the requirements of higher density, smaller size of electronic products. Moisture has big influence on the reliability of packaging, in which the major failures are corrosion, delamination and crack. In stacked die packages, the main risks of the moisture also exist. The focus of this paper is to investigate the hygroscopic characteristic of stacked die using commercial FEA software. In this study, according to the JEDEC standard, the moisture diffusion characteristic under different conditions is investigated. Results show that the substrate and bottom adhesive absorb rapidly in moisture diffusion simulation. This reduces the mechanical properties of the stacked die and the result may give a proper answer to those failure observed in industry. More tests are needed in order to get a more precise investigation.