Xingping Wang

US Patent:

20110097597, Apr 28, 2011

Filed:

Oct 28, 2009

Appl. No.:

12/607375

Inventors:

Yung-Herng Yau - Allentown PA, US
Xingping Wang - Frederick MD, US
Cai Wang - Milford CT, US
Robert Farrell - Lyme CT, US
Pingping Ye - Bethany CT, US
Karl F. Wengenroth - Stratford CT, US
Joseph A. Abys - Guilford CT, US

Assignee:

ENTHONE INC. - West Haven CT

International Classification:

B32B 15/01
B05D 1/18

US Classification:

428647, 427436

Abstract:

A method is provided for depositing a whisker resistant tin-based coating layer on a surface of a copper substrate. The method is useful for preparing an article comprising a copper substrate having a surface; and a tin-based coating layer on the surface of the substrate, wherein the tin-based coating layer has a thickness between 0.5 micrometers and 1.5 micrometers and has a resistance to formation of copper-tin intermetallics, wherein said resistance to formation of copper-tin intermetallics is characterized in that, upon exposure of the article to at least seven heating and cooling cycles in which each cycle comprises subjecting the article to a temperature of at least 217 C. followed by cooling to a temperature between about 20 C. and about 28 C., there remains a region of the tin coating layer that is free of copper that is at least 0.25 micrometers thick.