Dynamic Filling Characteristics of a Capillary Driven Underfill Process in Flip-Chip Packaging
- Authors
- Lee, Seong Hyuk; Lee, Hyung Jun; Kim, Jong-Min; Shin, Young Eui
- Issue Date
- Oct-2011
- Publisher
- JAPAN INST METALS
- Keywords
- underfill; flip-chip packaging; volume of fluid (VOF); computational fluid dynamics (CFD); encapsulation; filling time
- Citation
- MATERIALS TRANSACTIONS, v.52, no.10, pp 1998 - 2003
- Pages
- 6
- Journal Title
- MATERIALS TRANSACTIONS
- Volume
- 52
- Number
- 10
- Start Page
- 1998
- End Page
- 2003
- URI
- https://scholarworks.bwise.kr/cau/handle/2019.sw.cau/21238
- DOI
- 10.2320/matertrans.M2011151
- ISSN
- 1345-9678
1347-5320
- Abstract
- This study investigates the dynamic flow characteristics of capillary-driven underfill flows in a flip chip package. In the present study, we used two different bump arrays using Sn-2.5Ag solder balls with 80 mu m and 100 mu m diameters on commercially available flip chips, which have different pitches of 150 mu m and 180 mu m. First, we measured surface tension and viscosity with a rheometer and a tensiometer, respectively, and conducted an experimental visualization of the dynamic filling behavior of the underfill flows. From the captured images, we estimated the filling times, which can be affected by two important factors: bump arrangements and resin viscosities. In addition, we conducted a FVM (finite volume method)-based numerical simulation using commercial CFD code (Fluent v. 6.3.26), and compared its numerical results to both the experimental data and the analytical solutions given by the previous model described by Wan et al. (2005). The numerical predictions and analytical solutions estimating filling time were in good agreement with the experimental data, and the increase in spatial density of solder bumps allowed the flow to fill more slowly due to the increase in flow resistance. We conclude that the non-Newtonian characteristics and bump arrangement are very important factors in the design of flip-chip packaging. [doi:10.2320/matertrans.M2011151]
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - College of Engineering > School of Mechanical Engineering > 1. Journal Articles
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.