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. 21, 2014
Filed:
Sep. 14, 2011
Danielle A. Thomas, Dallas, TX (US);
Danielle A. Thomas, Dallas, TX (US);
STMicroelectronics, Inc., Coppell, TX (US);
Abstract
In capacitive sensor circuits where physical contact is required and excess pressure may be inadvertently applied to the sensor surface, aluminum is not sufficiently hard to provide 'scratch' protection and may delaminate, causing circuit failure, even if passivation integrity remains intact. Because hard passivation layers alone provide insufficient scratch resistance, at least the capacitive electrodes and preferably all metallization levels within the sensor circuit in the region of the capacitive electrodes between the surface and the active regions of the substrate are formed of a conductive material having a hardness greater than that of aluminum, and at least as great as the lowest hardness for any interlevel dielectric or passivation material employed.