Importance of molding compound chemical shrinkage in the stress and warpage analysis of PQFPs

Author

Kelly, Gerard ; Lyden, Colin ; Lawton, William ; Barrett, John ; Saboui, Alireza ; Pape, Heinz ; Peters, Henk J B

Author_Institution

Nat. Microelectron. Res. Centre, Univ. Coll. Cork, Ireland

Volume

19

Issue

2

fYear

1996

fDate

5/1/1996 12:00:00 AM

Firstpage

296

Lastpage

300

Abstract

This paper addresses the use of finite element (FE) techniques to predict residual warpage in plastic quad flat packs (PQFPs) after encapsulation. Experimental measurements of package warpage are used to validate FE models of the packages. Failure to incorporate mold compound chemical shrinkage into the FE analysis leads to erroneous predictions of package warpage. The warpage sensitivity of different packages to changes in downset is presented. The validated FE package models predict stress levels in packages which are 70% greater than those with temperature coefficient of expansion (TCE) shrinkage alone and questions the accuracy of previous simulations which do not include molding compound chemical shrinkage

Keywords

encapsulation; finite element analysis; integrated circuit packaging; plastic packaging; shrinkage; thermal expansion; PQFP; chemical shrinkage; downset; encapsulation; finite element techniques; molding compound; plastic quad flat packs; residual warpage; stress levels; temperature coefficient of expansion; warpage analysis; warpage sensitivity; Chemical analysis; Chemical compounds; Electronics packaging; Encapsulation; Failure analysis; Finite element methods; Plastics; Predictive models; Residual stresses; Temperature sensors;

fLanguage

English

Journal_Title

Components, Packaging, and Manufacturing Technology, Part B: Advanced Packaging, IEEE Transactions on

Publisher

ieee

ISSN

1070-9894

Type

jour

DOI

10.1109/96.496032

Filename

496032