Method and system for sealing a substrate
View Patent ↗A method of sealing a microelectromechanical system (MEMS) device from ambient conditions is described. The MEMS device is formed on a substrate and a substantially hermetic seal is formed as part of the MEMS device manufacturing process. The method may include forming a metal seal on the substrate proximate to a perimeter of the MEMS device using a method such as photolithography. The metal seal is formed on the substrate while the MEMS device retains a sacrificial layer between conductive members of MEMS elements, and the sacrificial layer is removed after formation of the seal and prior to attachment of a backplane.
1. An electronic device comprising a micro-electromechanical systems (MEMS) device, a metal layer, a mask, a metal seal layer, and a backplane prepared by a process comprising:
providing a MEMS device on a substrate;
depositing a metal layer on the substrate;
forming a mask with one or more perimeter cavities over the metal layer;
depositing one or more metal seal layers in the one or more perimeter cavities, thereby forming a seal proximate to the perimeter cavities of the MEMS device; and
joining a backplane to the seal.
2. The electronic device of claim 1 , wherein the MEMS device comprises an interferometric modulator.
3. The electronic device of claim 1 further prepared by a process comprising removing the mask, and the metal layer, at areas not covered by the one or more metal seal layers, thereby forming a sealant wall.
4. The electronic device of claim 3 further prepared by a process comprising removing a sacrificial layer from the MEMS device.
5. The electronic device of claim 1 further prepared by a process comprising applying a desiccant between the MEMS device and the backplane.
6. The electronic device of claim 5 , wherein the desiccant is selected from the group consisting of zeolites, molecular sieves, surface adsorbents, bulk adsorbents and chemical reactants.
7. The electronic device of claim 1 , wherein the desiccant comprises a powder.
8. The electronic device of claim 1 , wherein the seal proximate to the perimeter of the MEMS device comprises a non-hermetic seal.
9. The electronic device of claim 8 , wherein the non-hermetic seal is selected from the group consisting of conventional epoxy-based adhesive, polyisobutylene, butyl rubber, o-rings, polyurethane, thin film metal weld, liquid spin-on glass, solder, polymers and plastic.
10. The electronic device of claim 1 , wherein the seal proximate to the perimeter of the MEMS device comprises a substantially hermetic seal.
11. The electronic device of claim 10 , wherein the substantially hermetic seal comprises metal.
12. The electronic device of claim 1 further prepared by depositing an insulator layer on the substrate before depositing the metal layer.
13. The electronic device of claim 12 , wherein the depositing the insulator layer comprises depositing the insulator layer to contact the substrate.
14. The electronic device of claim 12 , wherein the depositing the insulator layer comprises depositing the insulator layer on at least one layer in contact with the substrate.
15. The electronic device of claim 14 , wherein the at least one layer comprises a conductive material.