US Patent 7309902 - Anti-stiction bump for MEMS

http://www.freepatentsonline.com/7309902.html

Stiction is a significant problem for micromechanical devices which can hinder operation rendering a microsensor or microactuator inoperable. Two common solutions are the use of an anti-stiction coating and the use of spacer elements to prevent contact between the movable member and a susbstrate. This patent from HP teaches a hybrid solution which uses an anti-stiction coating patterned exclusively on a spacer bump which allows for stiction prevention without interference with electrical contact portions that could occur if the anti-stiction coating was coated indiscriminately. Claim 1 reads:

1. A microelectronic device, comprising: a movable plate including a lower surface; a bump positioned on said lower surface; and an anti-stiction coating positioned only on said bump.