Membrane switch components and designs
AssigneeMemtronics Corporation
InventorDavid Forehand
Life of this patent
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Abstract
The present invention provides a method and apparatus for reducing temperature dependency within Microelectromechanical System (MEMS) switches. The two typical designs for such MEMS switches are fixed-fixed and fixed-free designs. Springs are used in the fixed-fixed design to account for dimensional changes as a result of thermal expansion. The fixed-free designs utilize a tether to prevent a cantilever arm from deforming as a result of thermal expansions, as well as reducing tight controls in the manufacture of fixed-free MEMS switches. Additionally, to prevent stiction in MEMS switches, a variegated electrode design is provided to utilize internal stresses of a suspended beam to increase the restoring force while not increasing the actuation force.
Claims17
An apparatus, wherein the apparatus is a temperature-independent microscopic switch, comprising:
- a substrate, wherein the substrate is at least configured to support the switch;
- a conductive beam, wherein the conductive beam is at least configured to be suspended from an anchor with one free end;
- means for engaging, wherein the means for engaging at least engages the conductive beam to allow signal transmission;
- and
- at least one tether, wherein the at least one tether is at least configured to be attached to a fixed location and attached to the conductive beam away from the anchor.
A MEMS device comprising
- a cantilever arm for completing an electrical path to at least a conducting surface, the cantilever arm having a portion attached to a substrate and a movable portion, which is suspended over the conducting surface;
- a tether having at least two ends, wherein a first end of the tether is at least coupled to a fixed location on the MEM device, and wherein a second end of the tether is at least coupled to the movable portion of the cantilever arm;
- and
- wherein the substrate is configured to be non-conductive.
A method of operation of a temperature-independent microscopic switch, comprising:
- moving a suspended beam portion of a fixed-free micromechanical beam used to complete an electrical path with an actuating force applied along the suspended beam portion;
- and
- limiting movement of the suspended beam portion of the fixed-free micromechanical beam with a tether attached to the fixed-free micromechanical beam at a point different than an attachment point for an anchor.
Dependencies are inferred from the claim text.