Title :
Surface contamination of bonding pads incapable of Au wire bonding
Author :
Watanabe, M. ; Tabuse, K.
Author_Institution :
Advantest Analysis Lab. Ltd., Japan
Abstract :
The spatial distribution of contamination in micro-areas of bonding pads in ICs and hybrid ICs is evaluated and graphically visualized by a micro-reflectometer of polarized light. Distributions of surface roughness, surface dielectric constant and the thickness of contaminant layers are calculated by nonclassical polarized light reflectance theory. It is shown that the reflectance ratio Rs/Rp of s- and p-light is an excellent indicator of surface contamination, and its variation is proportional to weakening of the bond strength. It is concluded that this system can be used in microdevice production lines to monitor accidental or inevitable pollution of micro-components such as bonding pads because of its speed, cleanliness, compactness, and low cost
Keywords :
hybrid integrated circuits; integrated circuit bonding; integrated circuit measurement; integrated circuit packaging; lead bonding; light polarisation; permittivity; reflectivity; reflectometry; surface contamination; surface topography; Au wire bonding; IC bonding pad micro-area contamination; bond strength; bonding pads; contaminant layer thickness; contamination spatial distribution; hybrid ICs; micro-components; microdevice production lines; nonclassical polarized light reflectance theory; polarized light; polarized light micro-reflectometer; reflectance ratio; surface contamination; surface dielectric constant; surface roughness; Bonding; Dielectric constant; Gold; Optical polarization; Reflectivity; Rough surfaces; Surface contamination; Surface roughness; Visualization; Wire;
Conference_Titel :
Electronics Manufacturing Technology Symposium, 1998. Twenty-Third IEEE/CPMT
Conference_Location :
Austin, TX
Print_ISBN :
0-7803-4523-1
DOI :
10.1109/IEMT.1998.731074
