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

Development of the wafer level compressive-flow underfill encapsulant

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

3 Author(s)
Shi, S.H. ; Center for Packaging Res., Georgia Inst. of Technol., Atlanta, GA, USA ; Yamashita, T. ; Wong, C.P.

This paper describes a wafer-level compressive flow underfill (WLCFU) for a novel SMT transparent flip-chip technology. In this flip-chip technology, the liquid fluxable WLCFU is coated over a patterned and bumped wafer. The WLCFU layer is dried at elevated temperature to form a solid layer. The coated bumped wafer is then diced into individual chips. These chips can then be placed on a substrate such as a PWB using standard SMT equipment. At elevated temperature (100-180°C) during solder reflow, the solid WLCFU layer can be re-melted and easily fills the gaps between chip and board. After solder reflow (190-200°C), the WLCFU material can be fully cured. B-stage epoxy technology was used to develop the WLCFU. A fluxing agent was added to provide sufficient fluxing for solder interconnection. A thermo-gravimetric analyzer (TGA) was used to investigate the drying kinetics and material weight loss during reflow. Differential scanning calorimetry (DSC) was used to study the WLCFU curing kinetics. A thermo-mechanical analyzer (TMA) was used to investigate the heat flex temperature (TMA Tg) and the coefficient of thermal expansion (CTE). A dynamic-mechanical analyzer (DMA) was used to measure the storage modulus (E') and cross-linking density (ρ) of the cured material. A rheometer was used to investigate viscosity (η) change with temperature during solder reflow. Preliminary results showed the feasibility of the proposed novel flip-chip technology with the developed WLCFU material. The basic qualifications of the WLCFU material were examined. Some technical barriers related to this technology are also discussed

Published in:

Advanced Packaging Materials: Processes, Properties and Interfaces, 1999. Proceedings. International Symposium on

Date of Conference:

14-17 Mar 1999

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.