The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 02, 1990
Filed:
Feb. 01, 1989
Clarence A Holden, Jr, Morris Township, Morris County, NJ (US);
Henry H Law, Berkeley Heights, NJ (US);
American Telephone and Telegraph Company, AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
An electrical device is provided which has contacts having regions with a conductive matte-finish metal surface. The matte-finish surface is characterized by having a Knoop hardness number of at least 300, a diffuse reflectance of less than about 20 percent, and a specular reflectance of less than about 2 percent. These contacts have a contact resistance of less than about 50 milliohms, under a 50-gram load, even after exposure to 50.degree. C. and 95% relative humidity for a period of 20 days. Reflection electron microscopy shows that particularly advantageous matte-finish surfaces have sharply peaked asperities with average peak angles of less than about 90 degrees. In one embodiment, the surface is formed of hardened nickel electroplated from an electrolytic bath with a pH above about 7.0.