Investigation of the reliability of Cu and Co UBM layers in thermal-cycling tests

Author

Labie, R. ; Beyne, Eric ; Mertens, Robert ; Ratchev, Petar ; Van Humbeeck, Jan

Author_Institution

IMEC, Leuven, Belgium

fYear

2003

fDate

10-12 Dec. 2003

Firstpage

584

Lastpage

588

Abstract

Despite the approaching ban on Pb in electronics, possibilities for replacing small pitch SnPb bumps are still limited. Electroplating, which is the most important process for small pitch bumping, complicates the alloy formation. In this paper, pure Sn bumps are investigated on their reliability behavior during thermal-cycling tests. Both electroplated Cu and Co are tested as UBM material. A Cu-SnPb sample is used as reference. The system lifetime of this reference sample could not be achieved with pure Sn. However, it is believed that by modifying some process conditions, the CoSn lifetime could be improved.

Keywords

cobalt; copper; electroplating; fine-pitch technology; flip-chip devices; integrated circuit metallisation; integrated circuit reliability; lead alloys; microassembling; solders; thermal stresses; tin; tin alloys; Co-Sn; Cu-Sn; Cu-SnPb; UBM layer reliability; alloy formation; electroplated UBM; electroplating process; fine pitch flip chip assembly; small pitch bumping; small pitch bumps; thermal-cycling tests; Alloying; Assembly; Flip chip; Geometry; Intermetallic; Materials testing; Packaging; Scanning electron microscopy; Temperature; Tin;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronics Packaging Technology, 2003 5th Conference (EPTC 2003)

Print_ISBN

0-7803-8205-6

Type

conf

DOI

10.1109/EPTC.2003.1271588

Filename

1271588