Open AccessFinite Volume Method Study on Contact Line Jump Phenomena and Dynamic Contact Angle of Underfill Flow in Flip-Chip of Various Bump Pitches
Author(s) -
Fei Chong Ng,
Aizat Abas,
M. Z. Abdullah
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/530/1/012012
Subject(s) - flip chip , materials science , void (composites) , jump , finite volume method , contact angle , mechanics , composite material , physics , adhesive , layer (electronics) , quantum mechanics
Three distinct flip-chip underfill cases were considered in this work, with each possess a bump pitch of 0.8 mm, 1.0 mm and 1.2 mm. Contact line jump (CLJ) phenomenon during the underfill flow were successfully visualized with the aided of finite volume method (FVM) based simulation. The current simulated underfill flow fronts were qualitatively validated with the existing experimental data. Generally, the attachment process occurs much faster than the detachment process, by a factor of 14. Within the investigated pitches range, shorter bump pitch would yield a slower underfill flow but a faster-completion underfill process. The voiding mechanism during the underfill process were presented. Furthermore, the dynamic contact angle of underfill meniscus were analytically computed from the numerical data. The contact angle is found to be varies sinusoidally with the filling time, while the impact of bump pitch is minimal. Lastly, it is found that the bump pitch of flip-chip does affect the void formation and propagation.