Metallurgy of Ti–W/Au/Cu system for TAB assembly

1 May 1985

journal article
Published by American Vacuum Society in Journal of Vacuum Science & Technology A

Vol. 3 (3) , 772-776
https://doi.org/10.1116/1.573303

Abstract

Tape automated bonding or TAB has been an I/C assembly method for over 15 years, but only recently has it gained such wide attention. One reason is that technology and equipment exist today to reliably and economically passivate I/C chips and electroplate bumps on chip bonding pads. Both are a prerequisite for TAB. One very successful metallization system for obtaining bumped wafers is that of Ti–W/Au. By using a load lock magnetron sputtering system for deposition of a Ti–W barrier layer, it is possible to both passivate the entire chip by sealing the pad and prevent interaction of the aluminum bonding pad with the gold bump which is required for automatically attaching the chip to a beamed tape. This barrier capability was tested by submitting 64 pin TAB bonded circuits to 1000 h bake at 200 °C in nitrogen. No degradation of the bump to pad interface was observed.

Keywords

This publication has 0 references indexed in Scilit: