MEMS (micro electro mechanical system) device and wafer-level vacuum packaging method thereof

Abstract

The invention discloses an MEMS (micro electro mechanical system) device and a wafer-level vacuum packaging method thereof, wherein the MEMS device is composed of a glass substrate (1), a silicon wafer sensitive structure layer with a sealing ring (2), and a silicon cap (9), and the MEMS device is characterized in that at least two silicon islands (11) are arranged in the silicon wafer sensitive structure layer, the bottom of each silicon island (11) is connected with the glass substrate (1) and an electrode lead (8), a press welding spot (6) is respectively arranged on the top of each silicon island (11); parts, corresponding to the silicon islands, on the silicon cap are respectively provided with a press welding spot cavity (7), so that the press welding spots (6) are arranged in the press welding spot cavities (7); and the periphery of each press welding spot cavity is provided with a press welding spot sealing ring (12) which is connected and matched with the top of each silicon island, and the periphery of each press welding spot sealing ring is provided with a press welding spot isolation channel (5). The MEMS device and the wafer-level vacuum packaging method thereof disclosed by the invention have the advantages that the technical problem of electrical isolation between the leakproof structure of the press welding spot and the press welding spots caused by that an electrode is led in the surface of the structural layer of the device from the substrate is avoided, so that the vacuum packaging structure of the MEMS device disclosed by the invention is reasonable in design, simple in process, long in vacuum retention time, reliable in performance and versatile, thereby reducing the cost for vacuum packaging.

Description

technical field [0001] The invention belongs to the field of micro-electromechanical technology, and relates to a MEMS device and a wafer-level vacuum packaging method for the MEMS device. Background technique [0002] MEMS (abbreviation for Micro Electro Mechanical systems, Micro Electro Mechanical Systems) devices usually contain some movable parts, these movable parts are very fragile, and are easily affected by factors such as dust and water vapor in the process of dicing and assembly, causing damage to the device Or the decline of the overall performance. At the same time, many MEMS devices need to work in a vacuum environment to reduce air damping and improve the quality factor Q value of the device. Such as MEMS accelerometers, micro gyroscopes, micro resonators, thin film pressure sensors, radio frequency MEMS components, vacuum field emitters and some optical MEMS devices, etc. The quality of vacuum packaging directly determines the performance of such devices, so ...

AI Technical Summary

Problems solved by technology

In addition, the glass-silicon bonded silicon process is used to carry out wafer-level vacuum packaging of MEMS devices. It mainly adopts the packaging structure method of punching lead through holes on the back of the substrate glass, but the process is complicated, high in cost, and short in vacuum holding time.

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