A piezoresistive mems acceleration sensor with composite beam structure and packaging device

Abstract

The invention discloses a piezoresistive MEMS acceleration sensor and an encapsulating device of a composite beam structure. The specific structure of the sensor is as follows: a frame is a square frame; five bonding pads are arranged on the frame; anchors are arranged on four edges of the frame. The silicon substrate is a frame substrate, the silicon substrate is a square plate structure, the size of the silicon substrate is consistent with the peripheral size of the frame, and the frame is bonded on the silicon substrate. The cross-section of the mass block is square, the four sides of the sensitive mass block are connected with anchors on the four sides of the frame through four sensitive beams, and the sensitive mass block is suspended on the silicon substrate. A varistor is arranged on each sensitive beam, the pins of the varistor are connected to the pad through metal leads, and the four varistors form a full-bridge Wheatstone bridge. The driving beam is a double-end fixed beam,two driving beams are arranged above the sensitive beam, the driving beam and the lower four-beam structure are bonded together, and the two driving beams are connected with each other through the driving mass.

Description

technical field [0001] The invention relates to the technical field of micro-electromechanical systems (MEMS), in particular to a piezoresistive MEMS acceleration sensor and a packaging device with a composite beam structure. Background technique [0002] With the rapid development of micromechanical MEMS acceleration sensors, they have been widely used in complex environments such as automobile collisions and penetrations, thanks to their small size, large bandwidth, low energy consumption, and impact resistance. Monocrystalline silicon has good mechanical properties, and its strength, hardness, and elastic modulus are close to those of steel, so it is the best material for making high-impact sensors. [0003] With the continuous improvement of micro-mechanical acceleration performance (resolution, sensitivity, bandwidth), high-g value MEMS sensors are subjected to very harsh environments, especially during the penetration process, not only the peak value will reach tens of...

AI Technical Summary

Problems solved by technology

For piezoresistive sensors of high-g value MEMS sensors, many scholars at home and abroad only use algorithms after layer penetration to identify the layer penetration information, but because the layer penetration time is very short, these algorithms are also difficult to use in actual target penetration. The center of mass of the cantilever beam and the center of mass of the cantilever beam are not on the same plane. Therefore, during high-speed collision or impact, the beam will be torsional and deformed, resulting in lateral disturbance. In order to meet higher requirements, the package of the sensor should not only consider the reliability, but also consider the impact of the package mode and damping on the signal output signal

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