Title :
A tin based TAB assembly process
Author :
Field, Daniel A.
Author_Institution :
Digital Equipment Corp., Andover, MA, USA
Abstract :
The feasibility of using a TinCap TAB (tape automated bonding) ILB (inner lead bond) structure to provide a strong ILB connection has been demonstrated. The project investigated placing a pad of tin on top of a gold TAB bump as part of the wafer fabrication process. The tin is then used to form a reflowed ILB joint with a gold-plated tape lead. This gold/tin bond should provide a strong joint while avoiding some of the problems associated with tin-plated TAB tape. This TAB bond is referred to as the TinCap ILB structure. The process development work included modifications to the current TAB photoresist imaging process, development of a tin plating capability, and formulation of a suitable etch chemistry for a tin/gold bump. An inner lead bonding process was developed through evaluating and testing of two separate bonding systems. A substantial reliability evaluation involving over 200 live devices was carried out to determine the suitability of this interconnect for future products
Keywords :
reliability; tape automated bonding; tin; Si-Au bonding; TAB assembly process; TinCap; TinCap ILB structure; etch chemistry; feasibility; inner lead bond; inner lead bonding process; photoresist imaging process; process development work; process evaluation; reflowed ILB joint; reliability evaluation; strong ILB connection; strong joint; tape automated bonding; wafer fabrication process; Assembly; Bonding processes; Chemistry; Etching; Fabrication; Gold; Resists; System testing; Tin; Wafer bonding;
Conference_Titel :
Electronics Manufacturing Technology Symposium, 1991., Eleventh IEEE/CHMT International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-0155-2
DOI :
10.1109/IEMT.1991.279740
