Prediction of gap in QFP with unattached heat spreader

Author

Lai, Yi-Shao ; Lin, Yi-Hsien ; Wu, Jenq-Dah

Author_Institution

Stress-Reliability Lab., Adv. Semicond. Eng. Inc., Kaohsiung, Taiwan

Volume

28

Issue

1

fYear

2005

fDate

3/1/2005 12:00:00 AM

Firstpage

136

Lastpage

141

Abstract

Due to cost and process considerations, sometimes the heat spreader of a quad flat package (QFP) is not attached to the die pad. Consequently, due to mismatch of thermal expansions of the components, gapping is inevitable on the unattached interface during temperature change. Presence of the gap would potentially decrease the reliability and thermal performance of QFP. In this paper, contact methodologies were incorporated into finite element models to calculate the distribution of gap on the unattached interface. Both plane two-dimensional and general three-dimensional models were built up and compared for a multi-chip module QFP with a drop-in heat spreader.

Keywords

finite element analysis; integrated circuit packaging; multichip modules; reliability; QFP reliability; contact methodologies; finite element models; gap distribution; multi-chip module; quad flat package; thermal expansions; unattached heat spreader; unattached interface; Capacitors; Costs; Electronic packaging thermal management; Electronics packaging; Fabrication; Finite element methods; Integrated circuit packaging; Temperature; Thermal expansion; Thermal management; Multi-chip module (MCM); quad flat package (QFP);

fLanguage

English

Journal_Title

Components and Packaging Technologies, IEEE Transactions on

Publisher

ieee

ISSN

1521-3331

Type

jour

DOI

10.1109/TCAPT.2004.843170

Filename

1402623