Hermetic seals for large optical packages and the like

Abstract

A MEMS product, particularly an optical MEMS product, and seal therefor. A housing member forms a cavity; a MEMS device is disposed in the cavity; a cap member (which may be an optical window) is dimensioned and configured to substantially cover the cavity; and a sealing member is sealingly attached to and between the housing member and the cap member. The sealing member may have a first attachment portion operatively attached by a first hermetic seal to the housing member and a second attachment portion operatively attached to the cap member by a second hermetic seal and the sealing member is impermeable to gas flow, whereby the cavity is hermetically sealed from ambient atmosphere external to the product. The sealing member is sufficiently resilient to allow motion due to differential thermal expansion between the housing member and the cap member without breaking either sealing attachment and further allowing the cap member to move in response to changes in barometric pressure, preferably with minimal tilting. The sealing member may comprise a ring element or member between the cavity housing and the window, and may take the form of a bellows formed of, e.g., nickel alloy, with a flexible portion intermediate two end attachment portions.

Dependencies are inferred from the claim text.