AVS 46th International Symposium
    Applied Surface Science Division Thursday Sessions
       Session AS-ThM

Paper AS-ThM9
A Study of the Surface Chemistry and Physical Properties Related to Adhesion of the Polyimide Passivation Layer by XPS, FTIR, and Contact Angle Measurements

Thursday, October 28, 1999, 11:00 am, Room 6A

Session: Real World Surface Analysis
Presenter: T. Jiang, Micron Technology Inc.
Authors: T. Jiang, Micron Technology Inc.
C.A, Bradbury, Micron Technology Inc.
M. Canavan, Micron Technology Inc
Correspondent: Click to Email
Adequate die-to-leadframe adhesion is necessary for lead on chip (LOC) package integrity during and after the manufacturing process. Poor adhesion may result in a variety of defects such as die adhesion failure, marginal wire bond, broken wire, and bent leads ultimately leading to electrical failure. Adhesion between the LOC tape and the polyimide passivation is affected by the surface properties of both materials. Understanding the relationships between these properties is important for the elimination of adhesion failures at die attach and for the continuous improvement of the manufacturing process. To this end, die which fail at attach are analyzed and compared with die which exhibit good adhesion characteristics. This study focuses on the surface chemistry and physical properties of the passivation layer using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and surface energy. Molecular concentrations and orientations are investigated and related to adhesion failures at die attach.