CN214011635U - MEMS-based non-equidistant comb tooth structure - Google Patents

Abstract

The utility model discloses a non-equidistant comb tooth structure based on MEMS, relating to the technical field of micro electro mechanical systems, comprising an upper comb tooth structure rotating around a rotating shaft and a lower comb tooth structure positioned below the upper comb tooth structure, wherein the upper comb tooth structure comprises a plurality of movable comb teeth arranged at intervals, the gap between the comb teeth which are farther away from the rotating shaft and the movable comb teeth is gradually increased, the lower comb tooth structure comprises a plurality of fixed comb teeth which are arranged at equal intervals, the movable comb teeth and the fixed comb teeth are arranged in a staggered way along the arrangement direction of the comb teeth and are not contacted with each other, the lower edges of the movable comb teeth are flush with the upper edges of the fixed comb teeth, the horizontal distance between each movable comb tooth and the adjacent right fixed comb tooth is unequal, according to the set value of the horizontal distance, when voltage is applied to the non-equidistant comb tooth structure, the movable comb teeth move to the gaps between the corresponding adjacent fixed comb teeth, and the central point of each movable comb tooth is kept on the central axis of the gap between the corresponding adjacent fixed comb teeth. Therefore, abnormal suction cannot occur, and the reliability of the MEMS device is ensured.

Description

MEMS-based non-equidistant comb tooth structure

Technical Field

The utility model belongs to the technical field of the micro-electromechanical system technique and specifically relates to non-equidistant broach structure based on MEMS.

Background

Micro-Electro-Mechanical systems (MEMS), also called Micro-Electro-Mechanical systems, microsystems, micromachines, etc., refer to high-tech devices having dimensions of a few millimeters or even smaller. MEMS are micro devices or systems that integrate micro sensors, micro actuators, micro mechanical structures, micro power sources, micro energy sources, signal processing and control circuits, high performance electronic integrated devices, interfaces, and communications. MEMS is a revolutionary new technology, and is widely applied to high and new technology industries.

Comb structures are widely used in MEMS devices, such as various capacitive sensors including accelerometers, gyroscopes, and various microactuators. The general MEMS comb tooth structure is flat, namely, the moving tooth and the fixed tooth of the comb tooth are in the same plane, and the comb tooth can only generate in-plane motion when being driven. When out-of-plane motion needs to be generated, high-low comb teeth, or vertical comb teeth, are needed, namely the moving teeth and the fixed teeth are not in the same plane. The high-low comb tooth structure can be used for manufacturing a scanning micro-mirror and is also an indispensable structure for realizing a three-axis accelerometer or a three-axis MEMS capacitive gyroscope.

In the prior art, the high and low comb teeth of a Variable Optical Attenuator (VOA) or an Optical switch chip are designed at equal intervals, as shown in fig. 1, the upper and lower comb teeth are all designed at equal intervals, that is, the parallel intervals of the upper and lower comb teeth are all d. When a voltage is applied to the chip, as shown in fig. 2, the upper comb teeth (i.e., the moving teeth) are excited to move to the gap position of the lower comb teeth (i.e., the fixed teeth), the angle is deflected to θ, and the deflection angle is kept constant at the current voltage. The distance between the upper comb teeth and the lower comb teeth is reduced due to the angular deflection, so that the electrostatic force between the comb teeth is overlarge, and the abnormal suction short circuit can be caused.

SUMMERY OF THE UTILITY MODEL

The present inventors have proposed MEMS-based non-equidistant comb tooth structures in view of the above-mentioned problems and technical needs. The technical scheme of the utility model as follows:

the utility model provides a non-equidistant broach structure based on MEMS micro-mirror, include around the rotatory last broach structure of pivot and be located the lower broach structure of broach structure below, it includes the movable broach that a plurality of interval set up to go up the broach structure, and the broach clearance of keeping away from the movable broach of pivot more increases gradually, lower broach structure includes the fixed broach that a plurality of interval set up, movable broach and fixed broach are crisscross along the broach arrangement direction and are set up, each other does not contact, and the lower limb of movable broach flushes with the top edge of fixed broach, the horizontal interval of every movable broach and the fixed broach on its adjacent right side is inequality, set for the horizontal interval:

wherein x is the horizontal distance between the rotating shaft and the central point of the fixed comb teeth closest to the rotating shaft, y is the horizontal distance between the central points of the adjacent fixed comb teeth, theta is the deflection angle of the upper comb tooth structure, and n is the number of the movable comb teeth;

when voltage is applied to the non-equidistant comb tooth structure, the movable comb teeth move to the gaps between the corresponding adjacent fixed comb teeth, and the central point of each movable comb tooth is kept on the central axis of the gap between the corresponding adjacent fixed comb teeth.

The utility model has the beneficial technical effects that:

under the condition that the total length of the upper/lower comb tooth structures is kept unchanged, the gap between movable comb teeth in the upper comb tooth structure is gradually increased, the gap between fixed comb teeth in the lower comb tooth structure is unchanged, and when voltage is applied to the non-equidistant comb tooth structure and the movable comb teeth move to the gaps between the adjacent fixed comb teeth, the central position of each movable comb tooth is kept on the central axis of the corresponding gap between the adjacent fixed comb teeth according to the horizontal distance set value of the movable comb tooth and the fixed comb tooth on the adjacent right side of the movable comb tooth, so that the problem of abnormal actuation of the upper/lower comb tooth structures in the prior art is solved.

Drawings

Fig. 1 is a conventional comb structure when not powered.

Fig. 2 is a schematic diagram of the movement of the conventional comb structure after power-up.

Fig. 3 is a non-equidistant comb structure provided by the present application when not powered.

FIG. 4 is a schematic diagram of the movement of the non-equidistant comb tooth structure after power-up provided by the present application.

FIG. 5 is a schematic combination diagram of a non-equidistant comb tooth structure provided by the present application.

Detailed Description

The following describes the embodiments of the present invention with reference to the accompanying drawings.

The application discloses non-equidistant broach structure based on MEMS, its schematic structure is shown in figure 3, including around the rotatory last broach structure 2 of pivot 1 and be located the lower broach structure 3 of last broach structure 2 below. Go up broach structure 2 and include the movable broach 21 that a plurality of interval set up, and keep away from 1 movable broach 21's of pivot broach clearance crescent more, also the central point of movable broach 21 deviates from to the right gradually along the axis in its adjacent fixed broach clearance that corresponds. Lower comb tooth structure 3 includes the fixed broach 31 that a plurality of equidistant y set up, and movable broach 21 sets up, each other does not contact along the broach arrangement direction with fixed broach 31 is crisscross, and the lower limb of movable broach 21 flushes with the upper edge of fixed broach 31, and every movable broach 21 is inequality rather than the horizontal interval of the fixed broach 31 on adjacent right side, also promptly d₁≠d₂≠d₃…≠d_nThe horizontal pitch is set to:

wherein, x is the horizontal distance between the rotating shaft and the center point of the fixed comb teeth closest to the rotating shaft, y is the horizontal distance between the center points of the adjacent fixed comb teeth, theta is the deflection angle of the upper comb tooth structure 2, and n is the number of the movable comb teeth and is a natural number.

Referring to fig. 4 and 5, when the voltage is applied to the non-equidistant comb tooth structure and the movable comb tooth 21 moves to the gap between the corresponding adjacent fixed comb teeth, the central point of each movable comb tooth 21 is ensured to be kept on the central axis 4 of the gap between the corresponding adjacent fixed comb teeth due to the set horizontal distance.

Compared with the prior art, the comb tooth structure with unequal intervals solves the problem of abnormal suction of the upper/lower comb tooth structure in the prior art under the condition of keeping the total length D of the upper/lower comb tooth structure unchanged. And because the number of the comb teeth of the upper/lower comb tooth structure remains unchanged, the non-equidistant comb tooth structure of the application can not change the electrostatic acting force.

What has been described above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiments. It is to be understood that other modifications and variations directly derivable or suggested by those skilled in the art without departing from the spirit and scope of the present invention are to be considered as included within the scope of the present invention.

Claims (1)

1. The utility model provides a non-equidistant broach structure based on MEMS, its characterized in that includes around the rotatory last broach structure of pivot and is located go up the lower broach structure of broach structure below, it includes the movable broach that a plurality of interval set up to go up the broach structure, and keeps away from the pivot more the broach clearance of movable broach increases gradually, lower broach structure includes the fixed broach that a plurality of interval set up, movable broach with fixed broach sets up, each other contactless along the broach arrangement direction, just the lower limb of movable broach with the upper edge of fixed broach flushes, every movable broach is rather than adjacent right side the horizontal interval of fixed broach is inequality, will horizontal interval sets for:

wherein x is the horizontal distance between the rotating shaft and the central point of the fixed comb teeth closest to the rotating shaft, y is the horizontal distance between the central points of the adjacent fixed comb teeth, theta is the deflection angle of the upper comb tooth structure, and n is the number of the movable comb teeth;

when voltage is applied to the non-equidistant comb tooth structure, the movable comb teeth move to the gaps between the corresponding adjacent fixed comb teeth, and the central point of each movable comb tooth is kept on the central axis of the gap between the corresponding adjacent fixed comb teeth.

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