A microelectromechanical system device

Abstract

This invention provides a microelectromechanical system (MEMS) device, comprising: at least two oppositely arranged movable structures, the movable structures moving in a first direction; a first mating part disposed on the movable structures; and a folding beam disposed between the two movable structures. The folding beam has a second mating part for mating with the first mating part, and the second mating part has a first stop member disposed in the first direction, the first stop member abutting against the first mating part. This invention solves the problem that adhesion can still occur between the interdigitated fingers under severe movement or overload conditions, even causing the folding beam to break, seriously affecting the reliability of the device.

Description

Technical Field

[0001] This utility model relates to the field of microelectromechanical systems (MEMS) technology, and more specifically, to a MEMS device. Background Technology

[0002] In microelectromechanical systems (MEMS), interdigital structures are the core units for electrostatic actuation and sensing, and their working principle relies on the precise maintenance of a micrometer-level gap between the movable structure and the stationary component. However, under impact or overload conditions, electrostatic instability can lead to uncontrolled displacement of the movable structure. Although the folded beam supporting the movable structure can mitigate the instability of finite elasticity and electrostatic actuation, there is still a risk that the interdigital electrodes may overextend and adhere.

[0003] To solve the above problems, related technologies typically set protrusions on adjacent interdigitated fingers. When the movable structure drives the interdigitated fingers to move, the protrusions on the interdigitated fingers will collide first, thereby preventing the interdigitated fingers from sticking together and realizing the limiting function.

[0004] However, under conditions of violent movement or overload, adhesion can still occur between the interdigitated fingers, which may even cause the folded beam to break, seriously affecting the reliability of the device. Utility Model Content

[0005] The problem solved by this invention is that adhesion can still occur between the interdigitated fingers under conditions of violent movement or overload, which can even cause the folding beam to break, seriously affecting the reliability of the device.

[0006] To address the aforementioned problems, this utility model provides a microelectromechanical system (MEMS) device, comprising: at least two movable structures arranged opposite each other, the movable structures moving in a first direction; a first mating portion disposed on one side opposite to the other movable structure; and a folding beam disposed between the two movable structures; wherein the folding beam has a second mating portion for mating with the first mating portion, the second mating portion having a first stop member in the first direction, the first stop member abutting against the first mating portion.

[0007] The technical effect achieved by adopting this solution is as follows: When any movable structure moves relative to or in the opposite direction along a first direction, the folding beam will bend and deform. By setting a first mating part on the movable structure and a second mating part on the folding beam, with a first stop on the second mating part, the folding beam and the movable structure will collide preferentially through the first stop when the movable structure moves. This effectively limits the range of motion of the movable structure and prevents excessive deformation of the folding beam, which could lead to breakage.

[0008] Furthermore, the folding beam has a bent portion and a body portion, the body portions are stacked along the first direction, and the bent portion connects to any end of an adjacent body portion; wherein, the second mating portion is located on the side of the bent portion away from the body portion.

[0009] The technical effects achieved by adopting this technical solution are as follows: the folding beam achieves elastic expansion and contraction in the first direction through the bending part and the main body; the bending part has higher strength, and when the second mating part is impacted by the first mating part, the bending part is not easily damaged or broken, thus better protecting the structure of the folding beam; furthermore, the bending part is limited within the first mating part through the second mating part, the deformation of the bending part in the first direction is limited, and the ends of the main body that are not connected by the bending part will not come into contact with each other and cause collision damage.

[0010] Furthermore, the first mating part is a mating groove, and at least a portion of the second mating part is located within the mating groove.

[0011] The technical effects achieved by adopting this technical solution are as follows: the sidewall of the mating groove can limit the second mating part, thereby limiting the displacement of the bending part of the folded beam in the first direction. At the same time, the strength of the bending part is higher than that of the main body. The limited displacement of the bending part will further limit the deformation of the main body, avoiding excessive deformation or even breakage of the main body under strong impact in the first direction, which would lead to device failure.

[0012] Furthermore, in the first direction, the size of the mating groove is larger than the size of the second mating part.

[0013] The technical effects achieved by adopting this technical solution are as follows: the second mating part has a certain amount of space for movement in the mating groove, that is, the movable structure on either side can move relative to the folding beam, thereby pushing the fork finger, and the mating grooves of the movable structures on both sides can limit the folding beam to prevent the folding beam from breaking.

[0014] Furthermore, a second stop is provided at the end of the second mating part away from the folding beam, and the second stop is used to abut against the mating groove in an orthogonal direction to the first direction.

[0015] The technical effect achieved by adopting this technical solution is that the second mating part is flexible in the orthogonal direction of the first direction. When the movable structure moves along the first direction, if the position of the folding beam is offset, the movable structure can limit the folding beam in the orthogonal direction of the first direction to provide an elastic buffering effect.

[0016] Furthermore, the second stop is a circular arc protrusion structure.

[0017] The technical effects achieved by adopting this technical solution are as follows: the arc surface design significantly reduces the contact area between the second stop and the inner wall of the mating groove, further reducing the risk of adhesion between the first stop and the inner wall of the mating groove in the first direction orthogonal direction, while improving the uniformity of stress distribution at the contact point and enhancing durability.

[0018] Furthermore, the first stop member is connected to the opposite sides of the second mating part.

[0019] The technical effect achieved by adopting this technical solution is that when the movable structure moves back and forth along the first direction, both the front and rear sides of the second mating part can contact a corresponding first stop, thus realizing the front and rear limit of the folding beam in the first direction.

[0020] Furthermore, the first stop member has an arc-shaped protrusion structure.

[0021] The technical effects achieved by adopting this technical solution are as follows: the arc surface design significantly reduces the contact area between the first stop and the inner wall of the mating groove, further reducing the risk of adhesion between the first stop and the inner wall of the mating groove in the first direction, while improving the uniformity of stress distribution at the contact point and enhancing durability.

[0022] Furthermore, the folding beam and the second mating part are an integral structure.

[0023] The technical effects achieved by adopting this solution are as follows: the folding beam and the second mating part can be integrally formed, for example, through the same deposition process and the same etching process, thus resulting in higher processing efficiency. Simultaneously, their integration is enhanced, making the folding beam and the second mating part less prone to breakage when the second mating part contacts the first stop.

[0024] In summary, the above-mentioned technical solutions of this application can have one or more of the following advantages or beneficial effects: i) A first stop and a second stop are provided in the direction of movement of the folding beam. The folding beam and the movable structure can collide preferentially through the first stop and the second stop, effectively limiting the movement range of the movable structure and avoiding excessive deformation of the folding beam, which could lead to breakage. Furthermore, the first stop and the second stop can reduce the contact area between the folding beam and the movable structure, reducing the risk of adhesion. ii) The sidewall of the mating groove can limit the second mating part, restricting the displacement of the second mating part in the first direction, and preventing excessive deformation of the folding beam under strong impact in the first direction, which could lead to breakage and sensor failure. iii) The arc surface design significantly reduces the contact area between the first stop and the inner wall of the mating groove, as well as the contact area between the second stop and the inner wall of the mating groove, reducing the risk of adhesion between the second mating part and the inner wall surface of the mating groove in the first direction and in the orthogonal direction of the first direction. At the same time, it improves the uniformity of stress distribution at the contact point and enhances durability. Attached Figure Description

[0025] Figure 1 A schematic diagram of the structure of a microelectromechanical system device provided in an embodiment of this utility model; Figure 2 for Figure 1 A magnified view of a portion of region A in the middle.

[0026] Explanation of reference numerals in the attached figures: 100 - Microelectromechanical system device; 110 - Movable structure; 120 - First mating part; 130 - Folding beam; 131 - Bending part; 132 - Body part; 140 - Second mating part; 141 - First stop; 142 - Second stop. Detailed Implementation

[0027] The purpose of this invention is to provide a microelectromechanical system device for limiting the movement between the folding beam and the movable structure, thereby preventing excessive deformation of the folding beam, which could lead to adhesion of the interdigitated fingers and breakage of the folding beam.

[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0029] See Figures 1-2 This utility model provides a microelectromechanical system (MEMS) device 100, which includes: at least two movable structures 110 arranged opposite each other, the movable structures 110 moving in a first direction; a first mating part 120 disposed on one side opposite to the other movable structure 110; and a folding beam 130 disposed between the two movable structures 110. The folding beam 130 is provided with a second mating part 140 for mating with the first mating part 120, and the second mating part 140 is provided with a first stop 141 in the first direction, the first stop 141 abutting against the first mating part 120.

[0030] In this embodiment, the movable structure 110 can be a mass block. When any movable structure 110 moves along the first direction, the folding beam 130 will bend and deform. By providing a first stop 141 and a second stop 142 in the direction of movement of the folding beam 130, the folding beam 130 and the movable structure 110 can collide preferentially through the first stop 141 and the second stop 142, effectively limiting the range of movement of the movable structure 110 and preventing excessive deformation of the folding beam 130, which could lead to breakage.

[0031] In one specific embodiment, the folding beam 130 has a bending portion 131 and a body portion 132, the body portions 132 are stacked along a first direction, and the bending portion 131 connects to any end of an adjacent body portion 132; wherein, the second mating portion 140 is provided on the side of the bending portion 131 away from the body portion 132.

[0032] It should be noted that the folding beam 130 achieves elastic expansion and contraction in the first direction through the bending deformation of the main body 132; the bending part 131 has higher strength, and when the second mating part 140 is impacted by the first mating part 120, the bending part 131 is not easily damaged or broken, thus better protecting the structure of the folding beam 130; and the bending part 131 is limited within the first mating part 120 by the second mating part 140, so the deformation of the bending part 131 in the first direction is limited, and the ends of the main body 132 not connected by the bending part 131 will not come into contact with each other and cause collision damage.

[0033] The folding beam 130 is bent multiple times to form a plurality of body parts 132 and a plurality of bent parts 131 connected in sequence. For each movable structure 110, there is at least one bent part 131 corresponding to the movable structure 110, and in each side of the bent part 131, there is at least one bent part 131 provided with a second mating part 140.

[0034] Preferably, the folding beam 130, the second mating part 140, and the first mating part 120 are all centrally symmetrical about the same center point, that is, the number of second mating parts 140 on both sides of the folding beam 130 is the same, and the number of first mating parts 120 on both sides of the folding beam 130 is the same, so that the two sides of the folding beam 130 achieve force balance through the abutment of the second mating parts 140 and the first mating parts 120 respectively, and are not prone to deflection relative to the first direction.

[0035] In one specific embodiment, the first mating part 120 is a mating groove, and at least a portion of the second mating part 140 is located within the mating groove.

[0036] It should be noted that the sidewall of the mating groove can limit the second mating part 140, thereby limiting the displacement of the bending part 131 of the folding beam 130 in the first direction. At the same time, the strength of the bending part 131 is higher than that of the main body part 132. The limited displacement of the bending part 131 will further limit the deformation of the main body part 132, so as to avoid excessive deformation of the main body part 132 of the folding beam 130 under strong impact in the first direction, which would lead to device failure.

[0037] Preferably, the second mating part 140 is a strip structure extending in an orthogonal direction along the first direction.

[0038] In one specific embodiment, the first stop 141 is connected to the opposite sides of the second mating portion 140. Specifically, when the second mating portion 140 is a strip structure, the first stop 141 is located on the two opposite long sides of the strip structure.

[0039] It should be noted that when the movable structure 110 moves back and forth along the first direction, the front and rear sides of the second mating part 140 can contact the movable structure 110 with a corresponding first stop 141, thereby achieving the front and rear limit of the folding beam 130 in the first direction and preventing the movable structure 110 from causing excessive movement of the interdigitated fingers, which would lead to the interdigitated fingers sticking together.

[0040] In one specific embodiment, the first stop 141 is an arc-shaped protrusion structure.

[0041] It should be noted that the arc surface design significantly reduces the contact area between the first stop 141 and the inner wall of the mating groove, further reducing the risk of adhesion between the first stop 141 and the inner wall of the mating groove in the first direction, while improving the uniformity of stress distribution at the contact point and enhancing durability.

[0042] Preferably, the arc protrusion structure of the first stop 141 is a small curvature arc surface, with the radius of curvature ranging, for example, from 0.5 micrometers to 5 micrometers.

[0043] Among them, at least one of the first stop 141 and the second stop 142 adopts a small curvature arc surface, which can achieve point contact and effectively reduce the adhesion force. This ensures that after the overload is eliminated, the elastic force from the folding beam 130 can easily overcome the adhesion force between the first stop 141, the second stop 142 and the first mating part 120, so that the movable structure 110 can be reset.

[0044] In one specific embodiment, in the first direction, the size of the mating groove is larger than the size of the second mating portion 140, that is, the size of the mating groove is larger than the width of the second mating portion 140 of the strip structure.

[0045] It should be noted that the second mating part 140 has a certain amount of space for movement within the mating groove, that is, the movable structure 110 on either side can move relative to the folding beam 130, thereby pushing the fork finger, and the mating grooves of the movable structures 110 on both sides can limit the folding beam 130 to prevent the folding beam 130 from breaking.

[0046] In one specific embodiment, a second stop 142 is provided at the end of the second mating part 140 away from the folding beam 130. The second stop 142 is used to abut against the mating groove in the orthogonal direction of the first direction.

[0047] It should be noted that the second mating part 140 is flexible in the orthogonal direction of the first direction. When the movable structure 110 moves along the first direction, if the position of the folding beam 130 is offset, the movable structure 110 can limit the folding beam 130 in the orthogonal direction of the first direction to provide an elastic buffering effect.

[0048] In one specific embodiment, the second stop 142 is an arc-shaped protrusion structure.

[0049] Preferably, the arc protrusion structure of the second stop 142 is a small curvature arc surface, with a curvature radius ranging, for example, from 0.5 micrometers to 5 micrometers.

[0050] It should be noted that the arc surface design significantly reduces the contact area between the second stop 142 and the inner wall of the mating groove, further reducing the risk of adhesion between the first stop 141 and the inner wall of the mating groove in the first direction orthogonal direction, while improving the uniformity of stress distribution at the contact point and enhancing durability.

[0051] In one specific embodiment, the folding beam 130 and the second mating part 140 are an integral structure.

[0052] It should be noted that the folding beam 130 and the second mating part 140 can be integrally formed, for example, through the same deposition process and the same etching process, thus resulting in higher processing efficiency. At the same time, the two have higher integration, and the folding beam 130 and the second mating part 140 are less likely to break when the first mating part 120 contacts the first stop member 141.

[0053] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A microelectromechanical system (MEMS) device, characterized in that, The microelectromechanical system (MEMS) device includes: At least two movable structures (110) arranged opposite each other, wherein the direction of movement of the movable structures (110) is a first direction; The first mating part (120) is disposed on the side of the movable structure (110) opposite to the other movable structure (110); A folding beam (130) is disposed between the two movable structures (110); The folding beam (130) is provided with a second mating part (140) for cooperating with the first mating part (120). The second mating part (140) is provided with a first stop (141) in the first direction. The first stop (141) is used to abut against the first mating part (120).

2. The microelectromechanical system device according to claim 1, characterized in that, The folding beam (130) has a bent portion (131) and a body portion (132), the body portion (132) being stacked along the first direction, and the bent portion (131) being connected to either end of an adjacent body portion (132); The second mating part (140) is located on the side of the bent part (131) away from the main body part (132).

3. The microelectromechanical system device according to claim 1, characterized in that, The first mating part (120) is a mating groove, and at least a portion of the second mating part (140) is located within the mating groove.

4. The microelectromechanical system device according to claim 3, characterized in that, In the first direction, the size of the mating groove is larger than the size of the second mating part (140).

5. The microelectromechanical system device according to claim 3, characterized in that, The second mating part (140) is provided with a second stop (142) at one end away from the folding beam (130), and the second stop (142) is used to abut against the mating groove in an orthogonal direction along the first direction.

6. The microelectromechanical system device according to claim 5, characterized in that, The second stop (142) is a circular arc protrusion structure.

7. The microelectromechanical system device according to claim 1, characterized in that, The first stop (141) is connected to the opposite sides of the second mating part (140).

8. The microelectromechanical system device according to claim 1, characterized in that, The first stop (141) is a circular arc protrusion structure.

9. The microelectromechanical system device according to claim 1, characterized in that, The folding beam (130) and the second mating part (140) are an integral structure.

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