Cart (Loading....) | Create Account
Close category search window
 

The effect of underfill epoxy on warpage in flip-chip assemblies

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

6 Author(s)
Wenge Zhang ; Dept. of Mech. Eng., Colorado Univ., Boulder, CO, USA ; Wu, D. ; Bingzhi Su ; Hareb, S.A.
more authors

The thermally-induced warpage of both a real flip-chip thermosonically bonded assembly and a simulated tri-layered assembly was investigated. It revealed the warpage of the assemblies was dominated by the forces applied by the underfill epoxy rather than the solder joints. The roles the underfill epoxy and solder joints played in causing warpage did not change even when the assembly had 196 solder joints under a 5.8 mm×5.8 mm chip. Mechanical properties of epoxy depend on the curing and the glass transition temperatures, and these characteristic temperatures clearly divide the warpage levels into two distinctive regions. When the maximum temperature the assembly was exposed to was less than the glass transition temperature (Tg), the warpage of the assembly was characterized by the curing temperature. When the maximum temperature the assembly was exposed to was higher than Tg, the warpage was characterized by Tg regardless of how high the temperature was. The distinctive deformation curves with sub-micron repeatability are reported for the first time. Depending upon the different characteristic temperatures of an assembly, e.g., 80°C for curing and 130°C for Tg, the warpage and the Von Misses stress each could increase by as much as a factor of two. Such an increase could affect device reliability for RF packages and alignment for optoelectronic packages

Published in:

Components, Packaging, and Manufacturing Technology, Part A, IEEE Transactions on  (Volume:21 ,  Issue: 2 )

Date of Publication:

Jun 1998

Need Help?


IEEE Advancing Technology for Humanity About IEEE Xplore | Contact | Help | Terms of Use | Nondiscrimination Policy | Site Map | Privacy & Opting Out of Cookies

A not-for-profit organization, IEEE is the world's largest professional association for the advancement of technology.
© Copyright 2014 IEEE - All rights reserved. Use of this web site signifies your agreement to the terms and conditions.