Electrothermal self-latching MEMS switch and method
AssigneeCoventor, Inc.
InventorShawn Jay Cunningham
Life of this patent
Estimating the term…
Abstract
Electrothermal Self-Latching MEMS Switch and Method. According to one embodiment, a microscale switch having a movable microcomponent is provided and includes a substrate having a stationary contact. The switch can also include a structural layer having a movable contact positioned for contacting the stationary contact when the structural layer moves toward the substrate. An electrothermal latch attached to the structural layer and having electrical communication with the movable contact to provide current flow between the electrothermal latch and the stationary contact when the movable contact contacts the stationary contact for maintaining the movable contact in contact with the stationary contact.
Claims28
A self-latching microscale switch having a movable microcomponent, the switch comprising:
- (a) a substrate including a stationary contact;
- (b) a structural layer having a movable contact positioned for contacting the stationary contact when the structural layer moves toward the substrate;
- and
- (c) an electrothermal latch attached to the structural layer and having electrical communication with the movable contact to provide current flow between the electrothermal latch and the stationary contact when the movable contact contacts the stationary contact for maintaining the movable contact in contact with the stationary contact.
A method for maintaining a microscale switch in a closed position, the method comprising:
- (a) providing a stationary contact formed on a substrate;
- (b) providing a movable microcomponent suspended above the substrate, the microcomponent comprising:
- (i) a structural layer having a movable contact positioned for contacting the stationary contact when the structural layer is moved towards the substrate;
- and
- (ii) an electrothermal latch attached to the structural layer and having electrical communication with the movable contact;
- (c) moving the structural layer towards the substrate whereby the movable contact moves into contact with the stationary contact;
- (d) providing current flow between the electrothermal latch and the stationary contact to maintain the movable contact in contact with the stationary contact.
A method for fabricating a self-latching microscale switch, the method comprising:
- (a) depositing a first conductive layer on a substrate;
- (b) forming a stationary contact by removing a portion of the first conductive layer;
- (c) depositing a sacrificial layer on the stationary contact and the first conductive layer;
- (d) depositing a second conductive layer on the sacrificial layer;
- (e) forming a movable contact by removing a portion of the second conductive layer;
- (f) depositing a structural layer on the movable contact and the sacrificial layer;
- (g) forming a via through the structural layer to the movable contact;
- (h) depositing a third conductive layer on the structural layer and in the via;
- (i) removing a portion of the third conductive layer to form an electrothermal latch, wherein the electrothermal latch electrically communicates with the movable contact through the via;
- and
- (j) removing a sufficient amount of the sacrificial layer so as to define a first gap between the stationary contact and the movable contact.
A method for maintaining a microscale switch in a closed position, the method comprising:
- (a) moving a structural layer having a movable contact towards a substrate having a stationary contact whereby the movable contact moves into contact with the stationary contact;
- and
- (b) applying a current through the movable contact, the stationary contact, and an electrothermal latch attached to the structural layer and in electrical communication with the movable contact, whereby the electrothermal latch maintains the movable contact in contact with the stationary contact.
Dependencies are inferred from the claim text.