Surface accumulation rate of diffusing species on thin gold electroplates

Author

Revay, L.

Author_Institution

Ericcson Telecom, Stockholm, Sweden

fYear

1991

fDate

6-9 Oct. 1991

Firstpage

193

Lastpage

198

Abstract

An analysis of the accumulated species on the surface of Co-hardened gold electroplates has been carried out. The samples were aged in a common basement air environment at 85, 125, and 150 degrees C for periods of 1 to 12 months. Different gold coating thicknesses were used: 0.3 and 1.0 mu m on phosphor bronze substrate with or without 5 mu m nickel underplates. The accumulation rates of surface films were evaluated using contact resistance probing. Auger electron spectroscopy was employed to characterize the surface species. The values of contact resistance (CR) recorded are consistent with parabolic growth kinetics and have been utilized to extrapolate estimated lifetimes based on the failure criteria of increases in CR to 20, 50, and 100 m Omega levels.<>

Keywords

ageing; cobalt alloys; contact resistance; copper alloys; electrical contacts; environmental testing; gold alloys; life testing; nickel; phosphorus alloys; reliability; substrates; tin alloys; 0.083 to 1.0 y; 0.3 to 1 micron; 20 to 100 mohm; 85 to 150 C; Au-CuSnP; Au-Ni-CuSnP; AuCo electroplates; Auger electron spectroscopy; accumulated species; basement air environment; coating thicknesses; contact materials; contact resistance; contact resistance probing; diffusing species; estimated lifetimes; failure criteria; lifetime extrapolation; parabolic growth kinetics; surface films accumulation rates; surface species; thermal ageing; thin Au electroplates; Aging; Chromium; Coatings; Contact resistance; Electrons; Gold; Nickel; Phosphors; Spectroscopy; Surface resistance;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical Contacts, 1991. Proceedings of the Thirty-Seventh IEEE Holm Conference on

Conference_Location

Chicago, IL, USA

Print_ISBN

0-7803-0231-1

Type

conf

DOI

10.1109/HOLM.1991.170824

Filename

170824