MEMS switch structure and preparation method thereof

Abstract

The invention relates to the technical field of micro electro mechanical systems, and discloses an MEMS switch structure and a preparation method thereof. The switch structure comprises a base, a device layer and an electrode layer, the device layer comprises a supporting structure and a main body structure, one end of the supporting structure is fixed on the base, and the other end of the supporting structure is fixedly suspended on the main body structure on the surface of the base; the main body structure comprises a beam body structure, a switch contact and a mass block, the beam body structure is folded, one end is connected with the supporting structure, and the other end is provided with the switch contact; the mass block is arranged on one side, relatively close to the switch contact, of the beam body structure; the electrode layer is arranged on the surface of the base and comprises an input electrode and an output electrode which are arranged at an interval; and when the beam body structure is in a deformation state, the switch contact is communicated with the input electrode and the output electrode. The beam body structure of the MEMS switch structure is a folding beam with a small transverse size, so that the closed load of the MEMS switch structure is effectively reduced, the reliability of the beam body structure is improved, and the service life of the switch structure is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-electromechanical systems, and in particular to a MEMS switch structure and a preparation method thereof. Background Art

[0002] A micro-electro-mechanical system (MEMS) switch is a miniature mechanical switch manufactured using micromachining technology. It has the advantages of small size, light weight, easy integration, and low control energy. It has been widely used in communications, sensors, medical equipment and other fields and has broad development prospects in the future.

[0003] The closing load of a MEMS switch is a key performance indicator. A larger closing load increases the difficulty of controlling the switch and limits its application environments. A commonly used method to reduce the closing load in related technologies is to increase the length of the cantilever beam that bears external impact or to reduce its thickness. This allows the cantilever beam to deform and connect with the electrode under a smaller closing load, thus forming a conductive circuit. However, increasing the cantilever beam's length increases the lateral dimensions of the switch device. A very long cantilever beam is difficult to guarantee reliability after long-term use. Reducing the cantilever beam's thickness also reduces its reliability. Summary of the Invention

[0004] In view of this, the present invention provides a MEMS switch structure and a preparation method thereof to solve the problem that the existing MEMS switch cannot take into account both reducing the closing load and ensuring the reliability of use.

[0005] In the first aspect, the present invention provides a MEMS switch structure, comprising: a base, a device layer and an electrode layer, the device layer comprising a support structure and a main body structure, one end of the support structure is fixed to the base, and the other end is fixed to the main body structure so that the main body structure is suspended above the surface of the base; the main body structure comprises a beam structure, a switch contact and a mass block, the beam structure is folded and one end is connected to the support structure, the switch contact is arranged at the other end of the beam structure away from the support structure; the mass block is arranged on a side of the beam structure relatively close to the switch contact; the electrode layer is arranged on the surface of the base, comprising an input electrode and an output electrode arranged at intervals; when the beam structure is in a deformed state, the switch contact connects the input electrode and the output electrode.

[0006] Beneficial effects: The folded beam structure and the mass block of the present invention together constitute a sensitive structure of the switch structure that bears external loads. When the beam structure is subjected to an external impact from top to bottom, it will bend and deform under its stiffness and strength, causing the switch contacts to shift toward the electrode layer and contact the input electrode and the output electrode at the same time, thereby connecting the input electrode and the output electrode to form a conductive loop, and the MEMS switch is closed; when the external impact disappears, the beam structure is reset, the switch contacts are away from the input electrode and the output electrode, the conductive loop is disconnected, and the MEMS switch is disconnected. Compared with the traditional MEMS switch structure with a single-beam cantilever beam, the beam structure of the MEMS switch structure of the present invention is configured as a folded beam to ensure that the lateral size of the beam structure is small; the folded beam structure and the mass block together constitute the sensitive structure of the switch structure, effectively reducing the external load that needs to be applied, while effectively reducing the closing load of the MEMS switch structure, improving the reliability of the beam structure and the service life of the switch structure.

[0007] In an optional embodiment, the beam structure includes:

[0008] a first beam, wherein a switch contact is provided at a first end of the first beam;

[0009] a second beam, the second beam being parallel to the first beam;

[0010] a third beam, the third beam being disposed at the second end of the first beam and connecting the first beam and the second beam;

[0011] A fourth beam, one end of the fourth beam is fixed to an end of the second beam away from the third beam, and the other end of the fourth beam is connected to the supporting structure; a preset angle is formed between the fourth beam and the second beam.

[0012] Beneficial effects: The folded beam structure of the present invention includes a first beam and a second beam that are arranged parallel to each other, and one end of the first beam and the second beam on the same side is connected by a third beam, and the entire beam structure is connected to the support structure by a fourth beam. Without increasing the lateral dimensions, the length of the beam structure that bears the closing load is the superposition of the length of the first beam and the length of the second beam, thereby effectively reducing the closing load. At the same time, the provision of a third beam connecting the first beam and the second beam helps to form an overall structure with balanced force. The overall stability of the beam structure is high, which improves the opening and closing efficiency and service life of the switch structure. In addition, when the second beam is bent downward by the impact force transmitted by the first beam, the fourth beam will twist relative to the support structure, further reducing the closing load required for the beam structure to form a conductive loop with the input electrode and the output electrode.

[0013] In an optional embodiment, the support structure includes a first support portion and a second support portion, and is respectively located on both sides of the beam structure;

[0014] The first beam comprises a cantilever beam, a first end of the cantilever beam being connected to the switch contact;

[0015] The second beam includes a first side beam and a second side beam, wherein the first side beam and the second side beam are respectively located on both sides of the cantilever beam and are parallel to the cantilever beam;

[0016] The third beam includes a connecting beam connected to the second end of the cantilever beam and connecting an end of the first side beam away from the first support portion and an end of the second side beam away from the second support portion;

[0017] The fourth beam includes a first torsion beam and a second torsion beam. One end of the first torsion beam is connected to the first side beam, and the other end is connected to the first support portion. One end of the second torsion beam is connected to the second side beam, and the other end is connected to the second support portion.

[0018] Beneficial effect: In the beam structure of the present invention, the first beam directly bears external impact, the first side beam and the second side beam are respectively arranged on both sides of the first beam and connected to the first support part and the second support part, and the first beam is supported by the third beam. Therefore, when the first beam is subjected to external impact, the third beam and the first side beam and the second side beam on both sides also serve as load-bearing beams, and the length of the load-bearing beam is also the superimposed length of the first beam and the second beam. In addition, the first torsion beam and the second torsion beam further enhance the bending deformation of the beam structure when subjected to external loads. The provision of side beams on both sides of the first beam helps to balance the force. Under the premise that the lateral size of the beam structure is not increased, the force balance of the beam structure is enhanced. Under the premise of ensuring a smaller closing load, the reliability of the switch structure is greatly improved.

[0019] In an optional embodiment, the width of the cantilever beam is L1, and the widths of the first side beam and the second side beam are both L2. Then the relationship between the width of the cantilever beam and the widths of the first side beam and the second side beam is: L1 / 6<L2<L1.

[0020] Beneficial effect: On the premise that the first side beam and the second side beam are respectively provided on both sides of the first beam, the maximum value of the width of the first side beam and the second side beam is set to be smaller than the width of the first beam, so as to ensure that the first beam can generate sufficient overall downward displacement when subjected to external impact, so that the switch contacts can quickly and reliably contact the input electrode and the output electrode. At the same time, the minimum value of the width of the first side beam and the second side beam is set to be greater than 1 / 6 of the width of the first beam, so as to avoid insufficient support of the first beam by the first side beam and the second side beam, resulting in deformation of the first side beam and the second side beam when the switch device is subjected to an error impact such as a collision, thereby driving the switch contacts on the first beam to contact the input electrode and the output electrode, forming unnecessary switch closure, and reducing the reliability of the switch structure.

[0021] In an optional embodiment, the main structure further includes: a counterweight block, which is arranged on a side of the beam structure relatively far away from the switch contacts.

[0022] Beneficial effects: The device layer of the present invention includes a beam structure, a switch contact arranged at one end of the beam structure, a mass block arranged at a position on the beam structure close to the switch contact, and a counterweight block arranged on the side of the beam structure away from the switch contact. The counterweight block is arranged to reduce the gap between the suspended device layer and the base surface as a whole, thereby reducing the external load that needs to be applied, quickly achieving contact between the switch contact and the input electrode and the output electrode, thereby completing the closure of the MEMS switch structure.

[0023] In an optional embodiment, it further includes: a plurality of conductive structures disposed through the base, the conductive structures being suitable for connecting the electrode layer with an external power source.

[0024] Beneficial effects: A conductive structure is formed in the base, vertical electrical interconnection through the base is achieved, and the integration of the MEMS switch structure is improved.

[0025] In an optional embodiment, the electrode layer further comprises:

[0026] a first electrode, at least a portion of the first electrode being located between the mass and the base;

[0027] a second electrode, at least a portion of the second electrode being located between the counterweight and the base;

[0028] The third electrode is connected to the support structure and is suitable for electrically connecting to the device layer.

[0029] Beneficial effects: The present invention sets a first electrode on the base surface below the mass block, sets a second electrode on the base surface below the counterweight block, and sets a third electrode connected to the support structure on the side of the support structure, so that a capacitance control structure is formed between the mutually spaced device layers and electrode layers, which assists in adjusting the distance between the main structure and the base surface and reduces the required closing load. Specifically, by controlling the electrostatic force between the mass block and the first electrode and the electrostatic force between the counterweight block and the second electrode, the main structure as a whole can be lowered by deforming the second beam in the beam structure under the action of the electrostatic force, while reducing the bending deformation of the first beam in the beam structure under external impact, so that when the switch structure is closed under external impact, the switch contacts can better contact with the input electrode and the output electrode, the contact area is increased, and the connection reliability is enhanced.

[0030] In an optional embodiment, the system further includes: a cover plate, which is fixedly disposed on the base, and a groove is provided on a side of the cover plate close to the base to accommodate the device layer and the electrode layer.

[0031] Beneficial effect: A cover plate with a groove is provided on one side of the upper surface of the base, which together with the base encloses the device layer and the electrode layer, thereby achieving effective protection for the device layer and the electrode layer, thereby improving the reliability and service life of the MEMS switch structure.

[0032] In the second aspect, the present invention also provides a method for preparing a MEMS switch structure, comprising: providing a base; forming an electrode layer on one side surface of the base, the electrode layer comprising an input electrode and an output electrode arranged at intervals; forming a device layer on one side surface of the base, the device layer comprising a support structure and a main body structure, one end of the support structure is fixed on the base, and the other end is fixed to the main body structure so that the main body structure is suspended on the surface of the base, the main body structure comprising a beam structure, a switch contact and a mass block, the beam structure is folded and one end is connected to the support structure, the switch contact is arranged at the other end of the beam structure away from the support structure, and the mass block is arranged on a side of the beam structure relatively close to the switch contact; when the beam structure is in a deformed state, the switch contact connects the input electrode and the output electrode.

[0033] Beneficial effects: The above-mentioned preparation process obtains a device layer having a folded beam structure and a mass block, and the beam structure and the mass block together constitute a sensitive structure of a switch structure that bears external loads; when the beam structure is subjected to an external impact from top to bottom, it will bend and deform under its stiffness and strength, so that the switch contact is offset toward the electrode layer, while contacting the input electrode and the output electrode, thereby connecting the input electrode and the output electrode to form a conductive loop, and the MEMS switch is closed; when the external impact disappears, the beam structure is reset, the switch contact is away from the input electrode and the output electrode, the conductive loop is disconnected, and the MEMS switch is disconnected. Compared with the traditional MEMS switch structure with a single cantilever beam, in the MEMS switch structure of this embodiment, the beam structure is configured as a folded beam, ensuring that the lateral size of the beam structure is small; the folded beam structure and the mass block together constitute the sensitive structure of the switch structure, effectively reducing the external load that needs to be applied, while effectively reducing the closing load of the MEMS switch structure, improving the reliability of the beam structure and the service life of the switch structure.

[0034] In an optional embodiment, after providing the base and before forming the electrode layer on one side surface of the base, the method further includes: forming a plurality of through holes penetrating the base; filling the plurality of through holes with a conductive material to form a plurality of conductive structures, the conductive structures being suitable for connecting the electrode layer with an external power source;

[0035] Forming an electrode layer on a side surface of the base includes: forming a first mask layer having a hollow area on the surface of the base; depositing an electrode material on the first mask layer, so that part of the electrode material is formed on the surface of the base through the hollow area; removing the first mask layer to form an electrode layer including an input electrode, an output electrode, a first electrode, a second electrode, and a third electrode on the surface of the base exposed in the hollow area;

[0036] Forming a device layer on a side surface of the base includes: providing an initial device layer, the initial device layer including a first surface and a second surface arranged opposite to each other, the first surface including a first region and a second region outside the first region; etching the first region of the initial device layer to form a support structure protruding from the first region in the second region; fixing the initial device layer with the support structure on the base, with the first surface of the initial device layer facing the base, and the support structure connected to the third electrode; etching one side of the second surface of the initial device layer to form a main structure, the main structure including a beam structure, a switch contact, a mass block and a counterweight block, the mass block corresponding to at least a portion of the first electrode, and the counterweight block corresponding to at least a portion of the second electrode;

[0037] After forming the device layer on one side surface of the base, the method further includes: arranging a cover plate on the base, and forming a groove on a side of the cover plate close to the base to accommodate the device layer and the electrode layer.

[0038] Beneficial effects: A conductive structure is formed inside the base to achieve vertical electrical interconnection through the base, thereby improving the integration of the MEMS switch structure. By forming a device layer on the surface of the base together with the first mask layer, the electrodes formed are relatively isolated from each other, ensuring insulation between the electrodes. First, a support structure is formed on the initial device layer, and then the initial device layer with the support structure is fixed on the base to form a main structure, which helps to improve processing efficiency and reduce alignment errors. A cover plate with a groove is provided on one side of the upper surface of the base, and the cover plate and the base together enclose the device layer and the electrode layer, thereby achieving effective protection of the device layer and the electrode layer, thereby improving the reliability and service life of the MEMS switch structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 is a schematic diagram of the internal structure of a MEMS switch structure according to an embodiment of the present invention;

[0041] Figure 2 is a cross-sectional schematic diagram of a MEMS switch structure according to an embodiment of the present invention;

[0042] Figure 3 is a structural schematic diagram of a device layer in a MEMS switch structure according to an embodiment of the present invention;

[0043] Figure 4 is a schematic top view of a device layer in a MEMS switch structure according to an embodiment of the present invention;

[0044] Figure 5 is a structural schematic diagram of an electrode layer in a MEMS switch structure according to an embodiment of the present invention;

[0045] Figure 6 is a schematic top view of the external structure of a MEMS switch according to an embodiment of the present invention;

[0046] Figure 7 is a schematic bottom view of the external structure of a MEMS switch according to an embodiment of the present invention;

[0047] Figure 8 is a schematic structural diagram of a base according to an embodiment of the present invention;

[0048] Figure 9 is a structural schematic diagram of a base and a conductive structure according to an embodiment of the present invention;

[0049] Figure 10 is a schematic structural diagram of an embodiment of the present invention after a first mask layer and an electrode material are provided on a base;

[0050] Figure 11 is a schematic structural diagram of an embodiment of the present invention after an electrode layer is formed on a base;

[0051] Figure 12 is a schematic structural diagram of an initial device layer according to an embodiment of the present invention;

[0052] Figure 13 is a schematic structural diagram of an embodiment of the present invention after a second mask layer is provided on the initial device layer;

[0053] Figure 14 is a schematic structural diagram of an embodiment of the present invention after a support structure is formed on an initial device layer;

[0054] Figure 15 This is a schematic structural diagram of an embodiment of the present invention after an initial device layer with a support structure is disposed on a base;

[0055] Figure 16 is a schematic structural diagram of the second surface of the initial device layer after thinning according to an embodiment of the present invention;

[0056] Figure 17is a schematic structural diagram of an embodiment of the present invention after a third mask layer is provided on the second surface of the initial device layer;

[0057] Figure 18 is a schematic structural diagram of an initial cover plate according to an embodiment of the present invention;

[0058] Figure 19 is a schematic structural diagram of an embodiment of the present invention after a fourth mask layer is provided on an initial cover plate;

[0059] Figure 20 2 is a schematic structural diagram of a cover plate according to an embodiment of the present invention.

[0060] Description of reference numerals:

[0061] 1. Base; 11. Conductive structure;

[0062] 2. Device layer; 21. Support structure; 21a. First support portion; 21b. Second support portion; 22. Main structure; 221. Beam structure; 2211. First beam; 2212. Second beam; 2212a. First side beam; 2212b. Second side beam; 2213. Third beam; 2214. Fourth beam; 2214a. First torsion beam; 2214b. Second torsion beam; 222. Switch contact; 223. Mass block; 224. Counterweight;

[0063] 3. Electrode layer; 31. Input electrode; 32. Output electrode; 33. First electrode; 34. Second electrode; 35. Third electrode;

[0064] 4. Cover plate; 41. Groove;

[0065] 100, first mask layer; 200, initial device layer; 201, first surface; 202, second surface; 300, electrode material; 400, initial cover plate; 500, second mask layer; 600, third mask layer; 700, fourth mask layer. DETAILED DESCRIPTION

[0066] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are intended only to illustrate the present invention and are not intended to limit it. It should also be noted that, for ease of description, the drawings only illustrate some, but not all, structures relevant to the present invention. In the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion about the present invention. The accompanying drawings illustrate various schematic diagrams of structures according to embodiments of the present invention. These figures are not drawn to scale; certain details may be exaggerated or omitted for clarity. The shapes, relative sizes, and positional relationships of various regions and layers shown in the figures are merely illustrative and may vary in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions based on actual needs. In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or an intervening layer / element may exist between them. In addition, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element would be "below" the other layer / element.

[0067] The closing load of a MEMS switch is an important parameter. A larger closing load will increase the difficulty of controlling the switch and limit its application environment. Therefore, it is necessary to ensure that the MEMS switch can achieve connection with the electrode layer 3 when subjected to a smaller closing load. In other words, the device layer 2 needs to be deformed under a smaller external impact, and the deflection distance caused by this deformation should be small, so that it can quickly achieve contact with the electrode layer 3 and form a conductive loop. However, due to the limitations of the processing technology and in order to ensure its own opening and closing function, the distance between the device layer 2 and the electrode layer 3 cannot be reduced indefinitely. Otherwise, the MEMS switch may be closed even with a slight error collision and fail to perform the opening and closing function. The commonly used method to reduce the closing load in the related art is to increase the length of the cantilever beam that bears the external impact or to reduce the thickness of the cantilever beam so that the cantilever beam can undergo a larger deformation under a smaller external impact and achieve contact with the electrode layer 3 to form a conductive loop. However, increasing the length of the cantilever beam will increase the lateral size of the switch device, which is not conducive to miniaturization and integration, and will reduce the reliability of use. Similarly, the reliability of the cantilever beam with a reduced thickness is difficult to guarantee, which reduces the service life of the device. Therefore, how to make the MEMS switch structure have both smaller closing load and higher reliability is the technical problem to be solved by this solution.

[0068] Based on this, reference Figures 1 to 7This embodiment provides a MEMS switch structure, including: a base 1, a device layer 2 and an electrode layer 3. The device layer 2 includes a support structure 21 and a main structure 22. One end of the support structure 21 is fixed on the base 1, and the other end is fixed to the main structure 22, so that the main structure 22 is suspended on the surface of the base 1; the main structure 22 includes a beam structure 221, a switch contact 222 and a mass block 223. The beam structure 221 is folded and one end is connected to the support structure 21. The switch contact 222 is arranged at the other end of the beam structure 221 away from the support structure 21; the electrode layer 3 is arranged on the surface of the base 1, and includes an input electrode 31 and an output electrode 32 arranged at intervals; when the beam structure 221 is in a deformed state, the switch contact 222 connects the input electrode 31 and the output electrode 32.

[0069] Exemplarily, the above-mentioned base 1 is made of silica glass, one side of its upper surface is used to form other structures; the device layer 2 including the support structure 21 and the main structure 22 is made of silicon wafers and has a certain strength and rigidity, wherein the support structure 21 is vertically arranged, with its lower end fixed to the upper surface of the base 1, and the upper end is fixed with the main structure 22; the main structure 22 extends horizontally and is suspended above the base 1, wherein one end of the beam structure 221 folded in the same horizontal plane is fixed to the support structure 21, and the other end is provided with a switch contact 222; the mass block 223 is arranged on the side of the beam structure 221 relatively close to the switch contact 222, and is suitable for directly bearing external loads, and the mass block The width and mass of 223 can be set to be larger than the original beam part. For example, the mass block 223 and the beam structure 221 are integrally formed, and silicon material is also used. The mass block 223 increases the mass of the beam structure 221 where the external load is applied; the electrode layer 3 is arranged on the upper surface of the base 1, and an input electrode 31 and an output electrode 32 that are not connected to each other are formed below the switch contact 222. The input electrode 31 and the output electrode 32 are used to connect to an external power supply, and the external power supply supplies power to them. For example, the electrode layer 3 in this embodiment uses the metal material gold. When gold is electrically connected to other materials, the contact resistance is low, which can achieve efficient electrical connection and improve the performance of the device.

[0070] In this embodiment, the folded beam structure 221 and the mass 223 together constitute the sensitive structure of the switch structure that bears external loads. When subjected to an external impact from above, the beam structure 221 bends and deforms due to its stiffness and strength, causing the switch contact 222 to deflect toward the electrode layer 3, contacting the input electrode 31 and the output electrode 32, thereby connecting the input electrode 31 and the output electrode 32 to form a conductive loop, and the MEMS switch closes. When the external impact disappears, the beam structure 221 resets, the switch contact 222 moves away from the input electrode 31 and the output electrode 32, the conductive loop is disconnected, and the MEMS switch opens. Compared to a conventional MEMS switch structure having a single cantilever beam, in the MEMS switch structure of this embodiment, the beam structure 221 is configured as a folded beam, ensuring that the lateral dimensions of the beam structure 221 are smaller. The folded beam structure 221 and the mass 223 together constitute the sensitive structure of the switch structure, effectively reducing the external load required. While effectively reducing the closing load of the MEMS switch structure, it also improves the reliability of the beam structure 221 and the service life of the switch structure.

[0071] In one embodiment, Figure 1 、 Figure 2 and Figure 4 As shown, the beam structure 221 includes: a first beam 2211, a second beam 2212, a third beam 2213 and a fourth beam 2214, and a switch contact 222 is set at the first end of the first beam 2211; the second beam 2212 is parallel to the first beam 2211; the third beam 2213 is set at the second end of the first beam 2211, and connects the first beam 2211 and the second beam 2212; one end of the fourth beam 2214 is fixed to the end of the second beam 2212 away from the third beam 2213, and the other end is connected to the support structure 21; there is a preset angle between the fourth beam 2214 and the second beam 2212.

[0072] The folded beam structure 221 includes a first beam 2211 and a second beam 2212 arranged parallel to each other. The ends of the first beam 2211 and the second beam 2212 on the same side are connected by a third beam 2213. A switch contact 222 is provided at the other end of the first beam 2211 away from the third beam 2213, and the other end of the second beam 2212 away from the third beam 2213 is connected to the support structure 21 via a fourth beam 2214. That is, the right side of the entire beam structure 221 is the first end of the first beam 2211, and the left side of the entire beam structure 221 is the second end of the first beam 2211. The third beam 2213 connects the first beam 2211 and the second beam 2212 on the left side thereof, and the third beam 2213 strengthens the connection strength between the first beam 2211 and the second beam 2212. The fourth beam 2214 connects the entire beam structure 221 to the support structure 21 on the right side of the second beam 2212. Figure 3 and Figure 4 As shown, in this embodiment, the end of the second beam 2212 is not fixed to the support structure 21 directly and rigidly, but rather by disposing a fourth beam 2214 on the side of the support structure 21 near the second beam 2212. The fourth beam 2214 extends into the interior of the support structure 21, but the support structure 21 is only connected to the support structure 21 at the front end, with a gap between the side ends and the support structure 21. That is, in this embodiment, the folded beam structure 221 includes a first beam 2211 and a second beam 2212 arranged parallel to each other, and the ends of the first beam 2211 and the second beam 2212 on the same side are connected by a third beam 2213. The entire beam structure 221 is connected to the support structure 21 via the fourth beam 2214. Without increasing its lateral dimensions, the beam structure 221 can withstand a closing load equal to the sum of the lengths of the first beam 2211 and the second beam 2212, effectively reducing the closing load. Furthermore, the provision of the third beam 2213 connecting the first beam 2211 and the second beam 2212 facilitates a balanced overall structure. This provides high overall stability for the beam structure 221, improving the switching efficiency and service life of the switch structure. Furthermore, when the second beam 2212 bends downward due to the impact force transmitted by the first beam 2211, the fourth beam 2214 twists relative to the support structure 21, further reducing the closing load required for the beam structure 221 to form a conductive loop with the input electrode 31 and the output electrode 32.

[0073] In this embodiment, the first beam 2211 and the second beam 2212 are set parallel to each other, the third beam 2213 is set perpendicular to the first beam 2211 and the second beam 2212, and the fourth beam 2214 is also set perpendicular to the first beam 2211 and the second beam 2212. That is, in this embodiment, the preset angle between the fourth beam 2214 and the second beam 2212 is 90°. Similarly, the fourth beam 2214 extends vertically into the support structure 21, which helps to balance the force, improve reliability, and facilitate batch processing and molding.

[0074] like Figure 1 、 Figure 2 and Figure 4 As shown, in this embodiment, the length of the first beam 2211 is greater than the length of the second beam 2212, and the portion of the first beam 2211 where the switch contact 222 is set is partially hollowed out, so that when the first beam 2211 is deformed, the contact surface between the switch contact 222 and the input electrode 31 and the output electrode 32 is larger, the contact is more complete, and the stability is higher, thereby achieving reliable closure of the switch.

[0075] As a preferred embodiment, the support structure 21 of the MEMS switch structure in this embodiment includes a first support portion 21a and a second support portion 21b, which are respectively located on both sides of the beam structure 221; the first beam 2211 includes a cantilever beam, and the first end of the cantilever beam is connected to the switch contact; the second beam includes a first side beam 2212a and a second side beam 2212b, which are respectively located on both sides of the cantilever beam and parallel to the cantilever beam; the third beam 2213 includes a connecting beam, The connecting beam is connected to the second end of the cantilever beam, and connects one end of the first side beam 2212a away from the first support part 21a and one end of the second side beam 2212b away from the second support part 21b; the fourth beam 2214 includes a first torsion beam 2214a and a second torsion beam 2214b, one end of the first torsion beam 2214a is connected to the first side beam 2212a, and the other end is connected to the first support part 21a; one end of the second torsion beam 2214b is connected to the second side beam 2212b, and the other end is connected to the second support part 21b.

[0076] That is, the beam structure 221 appears in the shape of a "mountain" after being rotated 90° on the horizontal plane, specifically including: a first beam 2211 as a cantilever beam arranged horizontally in the middle area, a first side beam 2212a and a second side beam 2212b arranged on the front and rear sides of the first beam 2211 respectively, a third beam 2213 arranged on the left side of the first beam 2211, the first side beam 2212a and the second side beam 2212b to connect the three, and a first torsion beam 2214a arranged on the right side of the first side beam 2212a and a second torsion beam 2214b arranged on the right side of the second side beam 2212b. In the beam structure 221 of this embodiment, the first beam 2211 disposed in the center directly bears external impacts. The first side beam 2212a and the second side beam 2212b are disposed on either side of the first beam 2211, respectively, and connected to the first support portion 21a and the second support portion 21b. The third beam 2213 supports the first beam 2211. Therefore, when the first beam 2211 is subjected to an external impact, the third beam 2213 and the first and second side beams 2212a, 2212b on either side also serve as load-bearing beams, each bearing a load equal to the combined length of the first and second beams 2211, 2212. Furthermore, the first and second torsion beams 2214a, 2214b further enhance the bending deformation of the beam structure 221 when subjected to external loads. The provision of side beams on both sides of the first beam 2211 helps balance the load. Without increasing the lateral dimensions of the beam structure 221, the beam structure 221 is subjected to enhanced force balance. This significantly improves the reliability of the switch structure while maintaining a low closing load.

[0077] When side beams are provided on both sides of the first beam 2211, the width of the first beam 2211 is L1, and the widths of the first side beam 2212a and the second side beam 2212b are both L2. Then, the relationship between the width of the first beam 2211 and the widths of the first side beam 2212a and the second side beam 2212b is: L1 / 6<L2<L1.

[0078] That is, under the premise of respectively setting the first side beam 2212a and the second side beam 2212b on both sides of the first beam 2211, the maximum width of the first side beam 2212a and the second side beam 2212b is set to be smaller than the width of the first beam 2211, so as to ensure that the first beam 2211 can generate sufficient overall downward displacement when subjected to external impact, so that the switch contact 222 can quickly and reliably contact the input electrode 31 and the output electrode 32. The minimum width must be greater than 1 / 6 of the width of the first beam 2211. If it is less than the minimum value, the first side beam 2212a and the second side beam 2212b have a very poor supporting effect on the first beam 2211. The first side beam 2212a and the second side beam 2212b are very likely to be deformed when the switch device is subjected to an error impact such as a collision, thereby causing the switch contact 222 on the first beam 2211 to contact the input electrode 31 and the output electrode 32, forming an unnecessary switch closure, and reducing the reliability of the switch structure.

[0079] It can be known that when a side beam is provided on one side of the first beam 2211 , the width of the side beam is the same as that of the first beam 2211 .

[0080] In addition, the main structure 22 of the above-mentioned MEMS switch structure also includes: a counterweight block 224, which is arranged on a side of the beam structure 221 relatively far away from the switch contact 222. Specifically in this embodiment, the counterweight block 224 is connected to the third beam 2213.

[0081] That is, the device layer 2 of this embodiment includes a beam structure 221, a switch contact 222 arranged at one end of the beam structure 221, a mass block 223 arranged on the beam structure 221 at a position close to the switch contact 222, and a counterweight block 224 arranged on the side of the beam structure 221 away from the switch contact 222. The counterweight block 224 is arranged to reduce the gap between the suspended device layer 2 and the surface of the base 1 as a whole, thereby reducing the external load that needs to be applied, quickly realizing the contact between the switch contact 222 and the input electrode 31 and the output electrode 32, thereby completing the closure of the MEMS switch structure.

[0082] In this embodiment, the silicon wafer is first etched to reduce the thickness of the first region of the silicon wafer, and a support structure 21 having a thickness greater than that of the first region is formed in a second region outside the first region of the silicon wafer; the support structure 21 is then bonded and fixed to the upper surface of the base 1 through a silicon-glass bonding process, so that the first region of the silicon wafer is suspended above the surface of the base 1; the first region of the silicon wafer is then etched through a bulk silicon process to complete the preparation of the device layer 2 including the beam structure 221, the switch contact 222, the mass block 223 and the counterweight block 224.

[0083] In one embodiment, the above-mentioned MEMS switch structure further includes: a plurality of conductive structures 11 disposed through the base 1 , and the conductive structures 11 are suitable for connecting the electrode layer 3 with an external power source.

[0084] For example, after providing a base 1 made of silicon dioxide, a through-glass via (TGV) technique is used to form a through-hole in the base 1, which is then filled with highly conductive copper metal to form a conductive structure 11. This allows vertical electrical interconnection through the base 1, thereby improving the integration of the MEMS switch structure. In this embodiment, a conductive structure 11 is provided under both the input electrode 31 and the output electrode 32, respectively, to achieve electrical conduction with the input electrode 31 and the output electrode 32.

[0085] like Figure 1 、 Figure 2 and Figure 5 As shown, the electrode layer 3 in this embodiment also includes: a first electrode 33, a second electrode 34 and a third electrode 35, at least part of the first electrode 33 is located between the mass block 223 and the base 1; at least part of the second electrode 34 is located between the counterweight block 224 and the base 1; the third electrode 35 is connected to the support structure 21, and the third electrode 35 is suitable for electrically connecting the device layer 2.

[0086] In this embodiment, a first electrode 33 is provided on the surface of the base 1 below the mass block 223, a second electrode 34 is provided on the surface of the base 1 below the counterweight block 224, and a third electrode 35 connected to the support structure 21 is provided beside the support structure 21. A conductive structure 11 is provided below the first electrode 33, the second electrode 34 and the third electrode 35, so that power is supplied to the conductive structure 11 in the base 1 by an external power supply, forming a conductive path from the external power supply, the conductive structure 11 under the third electrode 35, the third electrode 35, the support structure 21 to the suspended main structure 22, thereby forming a conductive layer in the main structure 22. In addition, the conductive structure 11 below the first electrode 33 and the second electrode 34 supplies power to the first electrode 33 and the second electrode 34, so that another conductive layer is formed on the plane where the first electrode 33 and the second electrode 34 are located, and finally the two conductive layers spaced apart from each other form a capacitance control structure, which assists in adjusting the distance between the main structure 22 and the surface of the base 1 and reduces the required closing load. Specifically, by controlling the electrostatic force between the mass block 223 and the first electrode 33 and the electrostatic force between the counterweight block 224 and the second electrode 34, the main structure 22 can be lowered as a whole through the deformation of the second beam 2212 in the beam structure 221 under the action of the electrostatic force, while reducing the bending deformation of the first beam 2211 in the beam structure 221 under external impact, so that when the switch structure is closed under external impact, the switch contact 222 can better contact with the input electrode 31 and the output electrode 32, the contact area is increased, and the connection reliability is enhanced.

[0087] Compared with using an external power supply to directly electrically connect the electrodes of the electrode layer 3 outside the base 1, in this embodiment, the conductive structure 11 is set inside the base 1, which improves the integration while also forming a reliable and stable electrical connection.

[0088] refer to Figure 2 、 Figure 6 and Figure 7 The MEMS switch structure of this embodiment further includes: a cover plate 4 fixedly disposed on the base 1 , and a groove 41 is provided on a side of the cover plate 4 close to the base 1 to accommodate the device layer 2 and the electrode layer 3 .

[0089] Specifically, the cover plate 4 is made of silicon material, and a groove 41 is formed by an etching process, and then it is bonded and fixed to the base 1 through a silicon-glass bonding process. A cover plate 4 with a groove 41 is provided on one side of the upper surface of the base 1, and together with the base 1, the device layer 2 and the electrode layer 3 are enclosed, thereby achieving effective protection for the device layer 2 and the electrode layer 3, thereby improving the reliability and service life of the MEMS switch structure.

[0090] In summary, the MEMS switch structure of this embodiment has two operating modes:

[0091] The first method applies voltage only to the input electrode 31 and the output electrode 32. The MEMS switch structure acts as a mechanical switch. When subjected to an acceleration greater than the switch closing threshold, the switch contact 222 is connected to the input electrode 31 and the output electrode 32 to form a conductive loop, and the switch is closed.

[0092] In the second method, in addition to applying voltage to the input electrode 31 and the output electrode 32, voltage is also applied to the first electrode 33, the second electrode 34 and the third electrode 35, so that a voltage difference is formed between the mass block 223 and the first electrode 33, and a voltage difference is formed between the counterweight block 224 and the second electrode 34. By changing the voltage difference, the distance between the device layer 2 and the upper surface of the base 1 can be adjusted, thereby changing the load required to close the MEMS switch device, so that the MEMS switch structure can be closed under a lower load.

[0093] In a second aspect, this embodiment further provides a method for preparing a MEMS switch structure, comprising:

[0094] Step S100: providing a base 1.

[0095] refer to Figure 8 , the base 1 is exemplarily set to be silica glass, and one side of its upper surface is used to form other structural layers.

[0096] In step S200 , an electrode layer 3 is formed on one side surface of the base 1 . The electrode layer 3 includes an input electrode 31 and an output electrode 32 that are spaced apart.

[0097] For example, the electrode layer 3 of this embodiment is made of the precious metal gold. Gold has low contact resistance when electrically connected to other materials, which can achieve efficient electrical connection and improve device performance.

[0098] In step S300, a device layer 2 is formed on one side surface of the base 1. The device layer 2 includes a support structure 21 and a main structure 22. One end of the support structure 21 is fixed on the base 1, and the other end is fixed to the main structure 22 so that the main structure 22 is suspended on the surface of the base 1. The main structure 22 includes a beam structure 221, a switch contact 222 and a mass block 223. The beam structure 221 is folded and one end is connected to the support structure 21. The switch contact 222 is arranged at the other end of the beam structure 221 away from the support structure 21. The mass block 223 is arranged on a side of the beam structure 221 relatively close to the switch contact 222; when the beam structure 221 is in a deformed state, the switch contact 222 connects the input electrode 31 and the output electrode 32.

[0099] Exemplarily, the device layer 2 is made of a silicon wafer and has a certain strength and rigidity, including an integrally formed beam structure 221, a switch contact 222 and a mass block 223, wherein the support structure 21 is vertically arranged relative to the surface of the base 1, with its lower end fixed to the upper surface of the base 1 and the upper end connected to the main structure 22; the main structure 22 extends horizontally and is suspended above the base 1, wherein one end of the beam structure 221 folded in the same horizontal plane is fixed to the support structure 21, and the switch contact 222 is arranged at the other end; the mass block 223 is arranged on a side of the beam structure 221 relatively close to the switch contact 222, and the mass block 223 increases the mass of the beam structure 221 where the external load is applied, and is suitable for directly bearing the external load.

[0100] In this embodiment, a silicon-glass bonding process can be used to fix the device layer 2 on the base 1. Silicon-glass bonding is achieved by utilizing the chemical reaction and physical mechanical force between the silicon wafer and the glass. During the bonding process, the surface of the base to be bonded and the surface of the device layer 2 are first cleaned, and an oxide layer is formed on the surface. Then, the device layer 2 is placed on the base 1, and a certain pressure and temperature are applied. At high temperatures, the oxide layer on the surface of the device layer 2 and the oxide layer on the surface of the base 1 will react chemically to form a bond. The silicon-glass bonding technology can achieve micron-level precision, which is suitable for manufacturing high-precision micro-nano devices.

[0101] In this embodiment, a device layer 2 having a folded beam structure 221 and a mass block 223 is obtained through the above-mentioned preparation process. The beam structure 221 and the mass block 223 together constitute a sensitive structure of a switch structure that bears external loads. When the beam structure 221 is subjected to an external impact from top to bottom, it will bend and deform under its stiffness and strength, so that the switch contact 222 is offset toward the electrode layer 3, and at the same time contacts the input electrode 31 and the output electrode 32, thereby connecting the input electrode 31 and the output electrode 32 to form a conductive loop, and the MEMS switch is closed. When the external impact disappears, the beam structure 221 is reset, the switch contact 222 moves away from the input electrode 31 and the output electrode 32, the conductive loop is disconnected, and the MEMS switch is disconnected. Compared with the traditional MEMS switch structure with a single cantilever beam, in the MEMS switch structure of this embodiment, the beam structure 221 is configured as a folded beam to ensure that the lateral dimension of the beam structure 221 is small; the folded beam structure 221 and the mass block 223 together constitute the sensitive structure of the switch structure, effectively reducing the external load that needs to be applied. While effectively reducing the closing load of the MEMS switch structure, it also improves the reliability of the beam structure 221 and the service life of the switch structure.

[0102] In one embodiment, after the step S100 of providing the base 1 and before the step S200 of forming the electrode layer 3 on one side surface of the base 1 , the method further includes:

[0103] A plurality of through holes are formed through the base 1 ; and a conductive material is filled in the plurality of through holes to form a plurality of conductive structures 11 , which are suitable for connecting the electrode layer 3 with an external power source.

[0104] For example, the base 1 is photoetched based on a patterned mask using TGV (Through Glass Via) technology, to form a plurality of through holes. After the through holes are formed on the base 1, highly conductive metal copper is filled to form a through hole. Figure 9 The conductive structure 11 shown achieves vertical electrical interconnection through the base 1, improving the integration of the MEMS switch structure. In this embodiment, a conductive structure 11 is provided under each of the input electrode 31 and the output electrode 32 to achieve electrical conduction between the input electrode 31 and the output electrode 32, respectively.

[0105] The above step S200, forming the electrode layer 3 on one side surface of the base 1, includes: Figure 10 As shown, a first mask layer 100 having a hollow area is formed on the surface of the base 1; an electrode material 300 is deposited on the first mask layer 100, and part of the electrode material 300 is formed on the surface of the base 1 through the hollow area; Figure 11 As shown, the first mask layer 100 is removed to form an electrode layer 3 including an input electrode 31 , an output electrode 32 , a first electrode 33 , a second electrode 34 and a third electrode 35 on the surface of the base 1 exposed in the hollowed-out area.

[0106] In this embodiment, the electrode layer 3 is bonded and fixed to the base 1 through a silicon-glass bonding process. A patterned first mask layer 100 is formed, and the area where the electrode needs to be formed is hollowed out. Then, the electrode material 300 is deposited on the upper side of the first mask layer 100, and the electrode layer 3 including the input electrode 31, the output electrode 32, the first electrode 33, the second electrode 34 and the third electrode 35 is formed through the hollowed area. In this way, the formed electrodes are relatively isolated from each other, ensuring the insulation between the electrodes.

[0107] The above step S300, forming the device layer 2 on one side surface of the base 1, includes:

[0108] Step S301 : providing an initial device layer 200 . The initial device layer 200 includes a first surface 201 and a second surface 202 that are opposite to each other. The first surface 201 includes a first region and a second region outside the first region.

[0109] For example, the initial device layer 200 may be a silicon wafer, which is easy to obtain and has low cost. Figure 12 As shown, the initial device layer 200 includes a first surface 201 and a second surface 202 that are opposite to each other. The edge portions of the first surface 201 on opposite sides are second regions, and the other regions are first regions.

[0110] Step S1302 , etching the first region of the initial device layer 200 to form a support structure 21 in the second region that protrudes from the first region.

[0111] like Figure 13 As shown, by covering the second region with a second mask layer 500, the initial device layer 200 in the first region is etched to a certain depth so that the support structure 21 formed in the second region protrudes from the first region, as shown in FIG. Figure 14 shown.

[0112] In step S303 , the initial device layer 200 with the support structure 21 is fixed on the base 1 , with the first surface 201 of the initial device layer 200 facing the base 1 , and the support structure 21 is connected to the third electrode 35 .

[0113] like Figure 15 As shown, the initial device layer 200 with the support structure 21 is flipped so that the first surface 201 faces the surface of the base 1, and the support structure 21 and the surface of the base 1 are fixed using a silicon-glass bonding process so that the first area of ​​the initial device layer 200 is suspended on the surface of the base 1.

[0114] It is known that after flipping and fixing, the second surface 202 of the initial device layer 200 should be thinned to obtain the corresponding thickness of the device layer 2, such as Figure 16 shown.

[0115] In step S304, etching is performed on one side of the second surface 202 of the initial device layer 200 to form a main structure 22, the main structure including a beam structure 221, a switch contact 222, a mass block 223 and a counterweight block 224, the mass block 223 corresponds to at least part of the first electrode 33, and the counterweight block 224 corresponds to at least part of the second electrode 34.

[0116] like Figure 17 As shown, etching is performed based on the patterned third mask layer 600 in the first area corresponding to the second surface of the initial device layer 200 through the bulk silicon process, thereby forming a main structure 22 including various structures such as a beam structure 221, a switch contact 222, a mass block 223 and a counterweight block 224, and finally forming a device layer 2 including a support structure 21 and a main structure 22.

[0117] The bulk silicon process refers to the use of single crystal silicon as the material to be processed. The surface of the material to be processed will be processed into various structures, and the required electronic components will be formed through steps such as deposition and masking. It is simple to process, has a wide range of applications, and can meet a wide range of application needs.

[0118] In this embodiment, before securing the initial device layer 200 to the base 1, the initial device layer 200 is first etched to form a support structure 21. The initial device layer 200 with the support structure 21 is then flipped over and secured to the base 1. Subsequently, a bulk silicon process is used to form beam structures 221 of varying shapes, switch contacts 222, mass blocks 223, and counterweights 224, ultimately forming a complete device layer 2. Prior to securing the initial device layer 200 to the base 1, the support structure 21 is first formed on the initial device layer 200, followed by the main structure 22 of the device layer 2 formed on the base 1. This simplifies the process, improves processing efficiency, and reduces alignment errors.

[0119] After forming the device layer 2 on one side surface of the base 1 in the above step S300, the following steps are further included:

[0120] In step S400 , a cover plate 4 is disposed on the base 1 . A groove 41 is formed on a side of the cover plate 4 close to the base 1 to accommodate the device layer 2 and the electrode layer 3 .

[0121] Specifically, the cover plate 4 is made of silicon material, see Figure 18 、 Figure 19 and Figure 20 , one side surface of the initial cover plate 400 is etched through the patterned fourth mask layer 700 to form a cover plate 4 with a groove 41, and then the flipped cover plate 4 is bonded and fixed to the base 1 through a silicon-glass bonding process to form a Figure 2 The MEMS switch structure shown in FIG. A cover plate 4 having a groove 41 is provided on one side of the upper surface of the base 1, and together with the base 1, encloses the device layer 2 and the electrode layer 3, thereby effectively protecting the device layer 2 and the electrode layer 3 and improving the reliability and service life of the MEMS switch structure.

[0122] The further functional description of each of the above modules is the same as that of the above corresponding embodiments and will not be repeated here.

[0123] While the above description does not provide detailed technical details regarding patterning and etching of each layer, those skilled in the art will appreciate that various technical means can be employed to form layers, regions, and the like in desired shapes. Furthermore, those skilled in the art may devise methods that differ from those described above to form the same structure. Furthermore, while each embodiment has been described separately, this does not mean that the measures in each embodiment cannot be advantageously combined.

[0124] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A MEMS switch structure, characterized in that: include: Pedestal; The device layer comprises a support structure and a main structure, wherein one end of the support structure is fixed to the base, and the other end is fixed to the main structure, and the main structure is suspended on the surface of the base; the main structure comprises a beam structure, a switch contact and a mass block, the beam structure is folded and one end is connected to the support structure; the switch contact is arranged at the other end of the beam structure away from the support structure; the mass block is arranged on a side of the beam structure relatively close to the switch contact; The electrode layer is arranged on the surface of the base, and includes input electrodes and output electrodes arranged at intervals; when the beam structure is in a deformed state, the switch contact connects the input electrode and the output electrode.

2. The MEMS switch structure according to claim 1, characterized in that: The beam structure comprises: a first beam, wherein the switch contact is disposed at a first end of the first beam; a second beam, the second beam being parallel to the first beam; a third beam, the third beam being disposed at the second end of the first beam and connecting the first beam and the second beam; A fourth beam, one end of the fourth beam is fixed to an end of the second beam away from the third beam, and the other end of the fourth beam is connected to the supporting structure; a preset angle is formed between the fourth beam and the second beam.

3. The MEMS switch structure according to claim 2, characterized in that: The support structure comprises a first support portion and a second support portion, and is respectively located on two sides of the beam structure; The first beam comprises a cantilever beam, a first end of the cantilever beam being connected to the switch contact; The second beam comprises a first side beam and a second side beam, wherein the first side beam and the second side beam are respectively located at two sides of the cantilever beam and are parallel to the cantilever beam; The third beam comprises a connecting beam, the connecting beam is connected to the second end of the cantilever beam, and connects an end of the first side beam away from the first supporting portion and an end of the second side beam away from the second supporting portion; The fourth beam includes a first torsion beam and a second torsion beam, wherein one end of the first torsion beam is connected to the first side beam, and the other end is connected to the first support portion; one end of the second torsion beam is connected to the second side beam, and the other end is connected to the second support portion.

4. The MEMS switch structure according to claim 3, characterized in that: The width of the cantilever beam is L1, and the widths of the first side beam and the second side beam are both L2. Then, the relationship between the width of the cantilever beam and the widths of the first side beam and the second side beam is: L1 / 6<L2<L1.

5. The MEMS switch structure according to any one of claims 1 to 4, characterized in that: The main structure also includes: A counterweight block is arranged on a side of the beam structure relatively far away from the switch contact.

6. The MEMS switch structure according to claim 5, characterized in that: Also includes: A plurality of conductive structures are arranged through the base, and the conductive structures are suitable for connecting the electrode layer with an external power source.

7. The MEMS switch structure according to claim 6, characterized in that: The electrode layer further comprises: a first electrode, at least a portion of which is located between the mass block and the base; a second electrode, at least a portion of which is located between the counterweight and the base; A third electrode is connected to the support structure, and the third electrode is suitable for electrically connecting to the device layer.

8. The MEMS switch structure according to claim 7, characterized in that: Also includes: The cover plate is fixedly arranged on the base, and a groove is arranged on a side of the cover plate close to the base to accommodate the device layer and the electrode layer.

9. A method for preparing a MEMS switch structure, used for preparing the MEMS switch structure according to any one of claims 1 to 8, characterized in that: include: Provide a base; An electrode layer is formed on a surface of one side of the base, wherein the electrode layer includes an input electrode and an output electrode arranged at intervals; A device layer is formed on one side surface of the base, the device layer includes a support structure and a main structure, one end of the support structure is fixed on the base, and the other end is fixed to the main structure, so that the main structure is suspended on the surface of the base; the main structure includes a beam structure, a switch contact and a mass block, the beam structure is folded and one end is connected to the support structure; the switch contact is arranged at the other end of the beam structure away from the support structure; the mass block is arranged on a side of the beam structure relatively close to the switch contact; when the beam structure is in a deformed state, the switch contact connects the input electrode and the output electrode.

10. The method for preparing a MEMS switch structure according to claim 9, characterized in that: After providing the base and before forming the electrode layer on one side surface of the base, the method further includes: forming a plurality of through holes penetrating the base; filling the plurality of through holes with a conductive material to form a plurality of conductive structures, wherein the conductive structures are suitable for connecting the electrode layer with an external power source; Forming an electrode layer on one side surface of the base includes: forming a first mask layer having a hollow area on the surface of the base; depositing an electrode material on the first mask layer, so that part of the electrode material is formed on the surface of the base through the hollow area; removing the first mask layer to form the electrode layer including the input electrode, the output electrode, the first electrode, the second electrode and the third electrode on the surface of the base exposed in the hollow area; Forming a device layer on a side surface of the base includes: providing an initial device layer, the initial device layer including a first surface and a second surface arranged opposite to each other, the first surface including a first area and a second area outside the first area; etching the first area of ​​the initial device layer to form a support structure protruding from the first area in the second area; fixing the initial device layer formed with the support structure on the base, the first surface of the initial device layer is arranged toward the base, and the support structure is connected to the third electrode; etching on one side of the second surface of the initial device layer to form the main structure, the main structure including the beam structure, the switch contact, the mass block and the counterweight block, the mass block corresponds to at least part of the first electrode, and the counterweight block corresponds to at least part of the second electrode; After forming the device layer on one side surface of the base, the method further includes: arranging a cover plate on the base, wherein a groove is formed on a side of the cover plate close to the base to accommodate the device layer and the electrode layer.

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