IEEE Transactions on Components and Packaging Technology, Vol. 22, No. 2, pp. 266-269, June 1999

New Findings in the Occurrence of False-Healing in Plastic Encapsulated Microcircuits using Scanning Acoustic Microscopy

Dr. Michael G. Pecht
CALCE Electronic Products and Systems Center
University of Maryland, College Park, MD 20742

Yogendra Ranade
LSI Logic Corporation
Milpitas, CA 95035.

T. M. Moore
Texas Instruments, Inc.,
Dallas, TX 75243 USA.


"False-healing" refers to the occasionally observed reduction of delamination in plastic encapsulated microcircuits. In previous studies, "false-healing" was reported only at the leadframe-plastic interface. It was thought that the chemical contaminants present in the ux enter the package and form corrosive products which fill up the internal air gaps. This paper reports on some new findings in the occurrence of false-healing in plastic packages using scanning acoustic microscopy. This study found that false-healing also occurs in instances where there was no exposure to corrosive media. Additionally, false healing was observed at the die-plastic interface, where chemical contaminants could not reach. Alternate explanations for this phenomenon are suggested and its impact on damage assessment of plastic encapsulated microcircuits is discussed.

Index Terms - Acoustic imaging, delamination, failure analysis, plastic packaging, soldering.

Complete article is available to CALCE Consortium Members.

© IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

[Home Page][Articles Page]