3-D Modeling and Characterization for Die Attach Process

• Published in: IEEE transactions on components, packaging, and manufacturing technology (2011) Vol. 6; no. 10; pp. 1567 - 1575
• Main Authors: Bu, Lin, Ching, Wai Leong, Ling, Ho Siow, Rhee, Min Woo, Fen, Yong Puay
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01-10-2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bond line thickness (BLT); Bonding; bonding force; Bonding forces; Computational modeling; die attach (DA) process; Force; Mathematical model; Stress; Stress analysis; Viscosity
• ISSN: 2156-3950; 2156-3985
• DOI: 10.1109/TCPMT.2016.2606112

A new 3-D model for the die attach (DA) process is established and validated in this paper. With this model, the fluid flow characteristics of the DA process can be predicted accurately. Dynamic mesh and interface tracking method were adopted in the modeling to study the compression motion and the front of DA. A force driven model was conducted for the parametric studies of different bonding forces. The model for the DA process was validated by the four materials, AP1, CA1, CA4, and DM60 in the optimized condition. Bond line thickness can be predicted by the simulation with ~20% accuracy. The simulation results show that the viscosity is one of the key properties, which has a significant effect on the required bonding force, bonding time, and DA contamination on the die top. Complete filling and DA contamination on the die top are two important standards to evaluate the good bonding force range in fluid dynamic analysis. Stress analysis illuminates that a fillet area is very critical and experiences highest stress during the reflow process.