MEMS (micro-electrochemical systems) accelerometer and production method thereof

Abstract

Disclosed are an MEMS (micro-electrochemical systems) accelerometer and a production method thereof. The MEMS accelerometer is in a tri-layer capacitive structure of glass, silicon and glass layers. The silicon layer comprises a first silicon pad and a second silicon pad. The first silicon pad is contacted with a metal electrode of a first glass layer. The second silicon pad is contacted with a metal electrode of a second glass layer. The first glass layer further comprises a first metal electrode outgoing through hole, a second metal electrode outgoing through hole and a silicone layer electrode outgoing through hole, which all form on a first glass substrate. The first metal electrode outgoing through hole corresponds to the first silicon pad in position. The second metal electrode outgoing through hole corresponds to the second silicon pad in position. Metal welding spots form on the first silicon pad and the second silicon pad respectively. A metal welding spot forms at the position on a silicon frame, which corresponds to the silicon layer electrode outgoing through hole. A metal electrode of the glass layer and a silicon layer electrode can be led out in a same plane, and the problem in packaging three electrodes which are led out in different planes is solved.

Description

technical field [0001] The invention relates to a microelectromechanical system (MEMS) device and its manufacturing technology, in particular to a MEMS high-precision accelerometer and its manufacturing method. Background technique [0002] MEMS accelerometers are an indispensable link in MEMS inertial systems and are currently used in many fields. There are two main working principles of MEMS accelerometers: capacitive and piezoresistive. Among them, piezoresistive accelerometers have disadvantages such as low precision and poor temperature characteristics, and their application fields are limited. Capacitive accelerometers mainly adopt two schemes: comb tooth type and "sandwich" type. The comb-tooth accelerometer mainly has the following problems: the mechanical strength difference between the sensitive axis and the non-sensitive axis of the sensitive structure is not large, and the sensitivity of the non-sensitive axis of the accelerometer is difficult to suppress; the d...

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Problems solved by technology

The comb-tooth accelerometer mainly has the following problems: the mechanical strength difference between the sensitive axis and the non-sensitive axis of the sensitive structure is not large, and the sensitivity of the non-sensitive axis of the accelerometer is difficult to suppress; the direction of the sensitive axis cannot provide a protective structure with sufficient mechanical strength , the impact resistance of the accelerometer is insufficient; the output value of the comb-tooth structure capacitance is small, and the sensitivity to external acceleration is low, so the comb-tooth accelerometer is mainly suitable for low-demand environments such as the consumer field

Foreign high-precision MEMS accelerometers adopt the process of cutting the accelerometer wafer into independent small chips, and packaging them in the shell in a vacuum environment. This vacuum packaging method has very strict requirements on the ability of the packaging equipment. The cost of packaging is very high, and it is almost impossible to achieve mass production in China

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