Accelerometer and manufacturing process thereof

Abstract

Disclosed is an accelerometer which includes a measurement body, and an upper cover plate silicon chip and a lower cover plate silicon chip, which are connected with the measurement body. The measurement body includes a framework, and movement spacing bodies, elastic beams and a mass block, which are arranged in the framework. The movement spacing bodies are far away from the framework and connected with the framework through connection arms. The mass block is connected with the movement spacing bodies through the elastic beams. Each group of elastic beam includes a vertical beam and four cross beams. Each group of two-end cross beams at the two ends of a corresponding vertical beam are connected with corresponding movement spacing bodies. Two middle-part cross beams at the middle part of a corresponding vertical beam are connected with the mass block. Cover plate silicon chips provided with electrodes are bonded on both of the upper and lower surfaces of the measurement body and capacitances are formed between the cover plate silicon chips and the measurement body. The accelerometer adopts a stress isolation design and has the characteristic of being high in measurement accuracy and in a chip packaging process, the structure of the accelerometer reduces deformation resulted from a packaging stress significantly so that the stability of the accelerometer is improved. Moreover, the geometrical shape and force-bearing vibration mode are both of a symmetrical structure so that the accelerometer has the characteristics of being high in measurement accuracy.

Description

Technical field [0001] The invention relates to the field of sensors, in particular to an accelerometer. Background technique [0002] Nowadays, accelerometers can be applied to many applications, such as measuring the intensity of earthquakes and collecting data, detecting the impact intensity of a car in a collision, and detecting the angle and direction of tilt in mobile phones and game consoles. With the continuous advancement of MEMS technology, many nano-scale small accelerometer accelerometers have been commercialized and widely used. [0003] Commonly used MEMS accelerometers are divided into piezoresistive and capacitive types. For example, the piezoresistive accelerometer has an application number of 200480003916.7 and a publication date of the Chinese invention patent application on March 15, 2006. Piezoresistive accelerometers are generally composed of a cantilever beam and a mass block, and a force sensitive resistor is arranged on the cantilever beam. The mass will ...

AI Technical Summary

Problems solved by technology

Packaging stress may cause deformation of the components of the accelerometer, making the accelerometer unable to accurately measure the acceleration, reducing the stability and reliability of the accelerometer

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