MEMS device, method of manufacturing the same, and electronic device

Abstract

The application provides a MEMS device and a manufacturing method thereof and an electronic device, the MEMS device comprising: a substrate; an electrode layer arranged on one side of the substrate and comprising a first signal line, a driving electrode and a second signal line arranged in sequence with intervals; a cantilever beam located on the side of the electrode layer away from the substrate and arranged with intervals from the driving electrode, one end of the cantilever beam being electrically connected with the second signal line, the other end being arranged with intervals from the first signal line, and the orthographic projection of the cantilever beam on the substrate partially overlapping the orthographic projection of the first signal line on the substrate; and a contact point arranged on one end of the first signal line close to the cantilever beam and / or arranged on one end of the cantilever beam close to the first signal line, used for connecting or disconnecting the cantilever beam and the first signal line under the control of the driving electrode, and at least one contact point being a flexible contact point. The MEMS device and the manufacturing method thereof and the electronic device provided by the application have simple structure, are convenient to manufacture, can effectively improve the stability of the device, avoid poor contact and have long service life.

Description

Technical Field

[0001] This application relates to the field of electronic device technology, and in particular to a MEMS device and its fabrication method, and an electronic device. Background Technology

[0002] RF MEMS (Radio Frequency Micro Electro Mechanical System) refers to micro-mechanical electronic systems used for radio frequency signal transmission and processing, widely applied in various base station communications, satellite communications, and mobile signal transmission. MEMS switching devices are micro-mechanical switches operating at frequencies from DC to millimeter waves, achieving on / off control through mechanical switch movement. Compared to traditional ferrite, FET (Field Effect Transistor), and PIN diode switches, MEMS switches offer advantages such as small size, low power consumption, low insertion loss, and good linearity, making them a consistently hot research topic in RF switching devices.

[0003] Depending on their operating principles, MEMS switches can be categorized into different types, such as parallel contact, parallel capacitor, and series contact. Switch performance evaluation primarily considers insertion loss, isolation, lifespan, drive voltage, and response time. Existing contact-type MEMS switches frequently experience high contact resistance and device damage during use; therefore, a more stable MEMS device is urgently needed. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a MEMS device and its fabrication method, as well as an electronic device.

[0005] A first aspect of this application provides a MEMS device, comprising: a substrate; an electrode layer disposed on one side of the substrate, including a first signal line, a driving electrode, and a second signal line disposed sequentially at intervals; a cantilever beam located on the side of the electrode layer away from the substrate and spaced apart from the driving electrode, one end of the cantilever beam being electrically connected to the second signal line, and the other end being spaced apart from the first signal line, wherein the orthographic projection of the cantilever beam on the substrate overlaps with the orthographic projection of the first signal line on the substrate; and a contact disposed at one end of the first signal line near the cantilever beam, and / or at one end of the cantilever beam near the first signal line, for connecting or disconnecting the cantilever beam and the first signal line under the control of the driving electrode, wherein at least one of the contacts is a flexible contact.

[0006] In some embodiments, an insulating layer is provided on the side of the electrode layer away from the substrate, the insulating layer covering the driving electrode and partially covering the first signal line and the second signal line.

[0007] In some embodiments, the cantilever beam has a first contact point on the side near the first signal line, and the orthographic projection of the first contact point on the substrate is a first projection, which at least partially overlaps with the orthographic projection of the first signal line on the substrate.

[0008] In some embodiments, a connecting beam connects the first contact and the cantilever beam, and the first projection covers the orthographic projection of the connecting beam onto the substrate.

[0009] In some embodiments, the connecting beam includes a first connecting portion, a U-shaped connecting portion, and a second connecting portion connected in sequence. One end of the first connecting portion is perpendicularly connected to the cantilever beam; the U-shaped connecting portion is parallel to the substrate; and one end of the second connecting portion is perpendicularly connected to the first contact point.

[0010] In some embodiments, the first signal line has a second contact on the side near the cantilever beam, and the orthographic projection of the second contact on the substrate is a second projection, which at least partially overlaps with the orthographic projection of the cantilever beam on the substrate.

[0011] In some implementations, the first projection coincides with the second projection; or, the first projection covers the second projection; or, the second projection covers the first projection.

[0012] In some embodiments, the second contact is disposed against the insulating layer located on the first signal line, and the thickness of the second contact is greater than or equal to the thickness of the insulating layer.

[0013] In some embodiments, the second projection overlaps with the orthographic projection of the insulating layer onto the substrate.

[0014] In some embodiments, the material of the first contact and / or the second contact includes a matrix adhesive and a liquid metal dispersed in the matrix adhesive, wherein the liquid metal includes one or more of gallium, indium, and tin, and the matrix adhesive includes one or more of polydimethylsiloxane adhesive, photoresist, polyimide adhesive, and UV-curable adhesive.

[0015] A second aspect of this application provides a method for fabricating a MEMS device as described in the first aspect above, comprising: forming an electrode layer on one side of a substrate, forming a contact on the side of the electrode layer away from the substrate, forming a cantilever beam on the side of the contact away from the substrate, wherein the cantilever beam is electrically connected to the electrode layer.

[0016] A third aspect of this application provides an electronic device including the MEMS device described in the first aspect above.

[0017] As can be seen from the above description, this application provides a MEMS device and its fabrication method, and an electronic device. The MEMS device includes: a substrate; an electrode layer disposed on one side of the substrate, including a first signal line, a driving electrode, and a second signal line arranged sequentially at intervals; a cantilever beam located on the side of the electrode layer away from the substrate and spaced apart from the driving electrode, one end of the cantilever beam being electrically connected to the second signal line, and the other end being spaced apart from the first signal line, the orthographic projection of the cantilever beam on the substrate overlapping the orthographic projection of the first signal line on the substrate; and a contact point disposed at one end of the first signal line near the cantilever beam, and / or at one end of the cantilever beam near the first signal line, for connecting or disconnecting the cantilever beam and the first signal line under the control of the driving electrode, wherein at least one contact point is a flexible contact point. By incorporating flexible contacts, damage to the contact surface caused by contact collisions can be effectively avoided, extending device lifespan. Furthermore, contact flexibility can prevent poor contact caused by the reaction force from a cantilever beam pulling down, ensuring device stability. Most importantly, contact flexibility not only guarantees effective contact between the lower surface of the contact and the signal line, but also allows for slight increases in contact area through voltage regulation, improving the device's RF performance. This MEMS device, its fabrication method, and electronic equipment feature a simple structure, are easy to manufacture, and effectively improve device stability, prevent poor contact, and extend service life. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the cross-sectional structure of the first type of MEMS device in the embodiments of this application;

[0020] Figure 2 for Figure 1 Flowchart of the first step in the fabrication of MEMS devices;

[0021] Figure 3 for Figure 1 Flowchart of the second step in the fabrication of MEMS devices;

[0022] Figure 4 for Figure 1 Flowchart of the third step in the fabrication of MEMS devices;

[0023] Figure 5 for Figure 1 Flowchart of the fourth step in the fabrication of MEMS devices;

[0024] Figure 6 for Figure 1 Flowchart of the fifth step in the fabrication of MEMS devices;

[0025] Figure 7 This is a schematic diagram of the cross-sectional structure of the second type of MEMS device in the embodiments of this application;

[0026] Figure 8 This is a schematic diagram of the cross-sectional structure of a connecting beam;

[0027] Figure 9 for Figure 8 Top view of the connecting beam;

[0028] Figure 10 This is a schematic diagram of the cross-sectional structure of a MEMS device in related technologies;

[0029] Figure 11 This is a schematic diagram of the cross-sectional structure of the third type of MEMS device in the embodiments of this application;

[0030] Figure 12 This is a schematic diagram of a structure in which a first contact and a second contact mate.

[0031] Figure 13 This is a schematic diagram of another structure in which the first contact and the second contact work together.

[0032] Reference numerals: 1. Substrate; 2-1. First signal line; 2-2. Driving electrode; 2-3. Second signal line; 3. Cantilever beam; 4. Contact; 4-1. First contact; 4-2. Second contact; 5. Insulating layer; 6. Connecting beam; 6-1. First connecting part; 6-2. U-shaped connecting part; 6-3. Second connecting part; 7. Sacrificial layer; 7-1. First groove; 7-2. Second groove. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0034] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] RF MEMS (Radio Frequency Micro Electro Mechanical System) refers to micro-mechanical electronic systems used for radio frequency signal transmission and processing, widely applied in various base station communications, satellite communications, and mobile signal transmission. MEMS switching devices are micro-mechanical switches operating at frequencies from DC to millimeter waves, achieving on / off control through mechanical switch movement. Compared to traditional ferrite, FET (Field Effect Transistor), and PIN diode switches, MEMS switches offer advantages such as small size, low power consumption, low insertion loss, and good linearity, making them a consistently hot research topic in RF switching devices.

[0036] Depending on their operating principles, MEMS switches can be categorized into different types, such as parallel contact, parallel capacitor, and series contact. Switch performance evaluation primarily considers insertion loss, isolation, lifespan, drive voltage, and response time. Existing contact-type MEMS switches frequently experience high contact resistance and device damage during use; therefore, a more stable MEMS device is urgently needed.

[0037] Contact-type MEMS switches typically consist of three parts: two signal transmission lines, a switching diaphragm bridge, and a driving electrode. The driving electrode controls the diaphragm bridge to pull down, connecting the two signal transmission lines. At this point, the contact resistance between the diaphragm bridge and the signal lines significantly affects the switch's insertion loss performance. Taking a series contact MEMS switch as an example, the signal transmission line is divided into two segments, AA and BB. One end of the switching diaphragm bridge is fixed to segment BB by an anchor point, while the other end has a contact on its lower surface, suspended above segment AA of the signal line. To reduce coupling between the diaphragm bridge and segment AA, the leading edge of the signal line is usually comb-shaped, with the center of the contact on the lower surface of the diaphragm bridge facing the comb-shaped structure. A driving electrode is also designed below the switching diaphragm bridge to control the switch's driving state. During normal operation, there is no electrostatic force from the voltage difference between the switching diaphragm bridge and the driving electrode, and the cantilever beam remains raised. Because segment AA and segment BB of the signal line are disconnected, the radio frequency signal is interrupted and cannot be transmitted. When a voltage difference exists between the switching diaphragm bridge and the driving electrode, the electrostatic force of the plate will pull the upper switching diaphragm bridge down until the cantilever beam contact makes contact with segment AA of the signal line. The switching diaphragm bridge then conducts between segments AA and BB, allowing the radio frequency signal to be transmitted. Currently, this type of switch requires hard contact between the contact and the signal line to achieve electrical connection, such as using rigid contacts made of metal. This leads to several problems: 1) contact damage due to collision with the signal line; 2) thermoelectric effects during contact causing micro-welding, micro-melting, and micro-corrosion; 3) poor contact morphology during design and fabrication resulting in a small contact area, leading to high contact resistance and high insertion loss. Therefore, MEMS devices exhibit poor stability and are prone to high contact resistance and device damage.

[0038] The following describes specific embodiments in conjunction with... Figures 1 to 13 The technical solution of this application will be described in detail below.

[0039] Some embodiments of this application provide a MEMS device, such as... Figure 1 As shown, it includes: a substrate 1; an electrode layer disposed on one side of the substrate 1, including a first signal line 2-1, a driving electrode 2-2, and a second signal line 2-3 arranged sequentially at intervals; a cantilever beam 3 located on the side of the electrode layer away from the substrate 1 and spaced apart from the driving electrode 2-2, one end of the cantilever beam 3 being electrically connected to the second signal line 2-3, and the other end being spaced apart from the first signal line 2-1, the orthographic projection of the cantilever beam 3 on the substrate 1 overlapping the orthographic projection of the first signal line 2-1 on the substrate 1; and a contact 4 disposed at one end of the first signal line 2-1 near the cantilever beam 3, and / or at one end of the cantilever beam 3 near the first signal line 2-1, for connecting or disconnecting the cantilever beam 3 and the first signal line 2-1 under the control of the driving electrode 2-2, at least one of the contact points 4 being a flexible contact.

[0040] like Figure 1 As shown, the MEMS device includes a substrate 1. An electrode layer is provided on one side of the substrate 1. The electrode layer includes a first signal line 2-1 and a second signal line 2-3 spaced apart. When the first signal line 2-1 and the second signal line 2-3 are turned on, they can transmit radio frequency signals. A driving electrode 2-2 is provided between the first signal line 2-1 and the second signal line 2-3, and is spaced apart from the first signal line 2-1 and the second signal line 2-3. The driving electrode 2-2 is used to control the movement of the subsequent cantilever beam 3. A cantilever beam 3 is provided on the top surface of the driving electrode 2-2, spaced apart from the driving electrode 2-2. The cantilever beam 3 is made of conductive material. One end is connected to the second signal line 2-3, and the other end is spaced apart from the first signal line 2-1. The end of the cantilever beam 3 overlaps with the first signal line 2-1 in the projection, so that under the electrostatic pressure of the driving electrode 2-2, the cantilever beam 3 moves downward to contact the first signal line 2-1, realizing the connection between the first signal line 2-1 and the second signal line 2-3. A contact 4 is provided at one end of the first signal line 2-1 near the cantilever beam 3, and / or at one end of the cantilever beam 3 near the first signal line 2-1. For example, the contact 4 is provided only on the upper surface of the end of the first signal line 2-1 near the cantilever beam 3, or only on the lower surface of the end of the cantilever beam 3 near the first signal line 2-1, or the contact 4 is provided at both of these locations. The contact 4 can reduce the distance between the cantilever beam 3 and the first signal line 2-1, and is made of conductive material, which facilitates the drive electrode 2-2 to control the connection or disconnection of the first signal line 2-1 and the second signal line 2-3.

[0041] In the aforementioned contact 4, at least one contact 4 is a flexible contact. For example, the material of contact 4 can be changed, such as using liquid metal dispersed in a matrix adhesive to make contact 4, which ensures electrical connection while avoiding rigid contact. Alternatively, the structure of contact 4 can be changed, such as adding a smaller connecting beam 6 between contact 4 and cantilever beam 3 or the first signal line 2-1, giving contact 4 a certain degree of displacement freedom for buffering. By setting flexible contacts, the problem of contact surface damage caused by collisions can be effectively avoided, extending the device life. In addition, the flexibility of contact 4 can also effectively prevent the cantilever beam 3 from bouncing away due to the reaction force of the collision after being pulled down, resulting in poor contact state, thus ensuring the stability of device operation. Most importantly, the flexibility of contact 4 not only ensures an effective contact surface between the lower surface of contact 4 and the signal line, but also allows for a slight increase in the contact surface area through voltage regulation, improving the RF performance of the device.

[0042] This MEMS device has a simple structure, is easy to manufacture, can effectively improve device stability, avoid poor contact, and has a long service life.

[0043] In some embodiments, such as Figure 1As shown, an insulating layer 5 is provided on the side of the electrode layer away from the substrate 1. The insulating layer 5 covers the driving electrode 2-2 and partially covers the first signal line 2-1 and the second signal line 2-3.

[0044] like Figure 1 As shown, an insulating layer 5 is provided in the upper part of the first signal line 2-1 and the second signal line 2-3 to avoid incorrect connection of the lines. The surface of the driving electrode 2-2 is covered with an insulating layer 5 to prevent the cantilever beam 3 from directly contacting the driving electrode 2-2 and causing a short circuit.

[0045] In some embodiments, such as Figure 7 As shown, the cantilever beam 3 has a first contact 4-1 on the side near the first signal line 2-1. The orthographic projection of the first contact 4-1 on the substrate 1 is the first projection, and the first projection at least partially overlaps with the orthographic projection of the first signal line 2-1 on the substrate 1.

[0046] like Figure 7 As shown, a first contact 4-1 is connected to the lower surface of the cantilever beam 3. The cross-sectional shape of the first contact 4-1 is, for example, rectangular, circular or elliptical, etc., and is not specifically limited. The first contact 4-1 overlaps with the projected portion of the first signal line 2-1, which facilitates the drive electrode 2-2 to control the connection or disconnection of the first signal line 2-1 and the second signal line 2-3. The first contact 4-1 can be set as a flexible contact to avoid rigid contact.

[0047] In some embodiments, such as Figure 7 As shown, a connecting beam 6 connects the first contact 4-1 and the cantilever beam 3, and the first projection covers the orthographic projection of the connecting beam 6 on the substrate 1.

[0048] like Figure 7 As shown, a connecting beam 6 is added between the first contact 4-1 and the lower surface of the cantilever beam 3. The material of the connecting beam 6 can be the same as that of the first contact 4-1. This method can further achieve flexible contact of the contact 4. In the initial state, the first contact 4-1 is suspended above the first signal line 2-1. When a driving voltage is applied, the cantilever beam 3 is pulled down under the action of electrostatic force, and the first contact 4-1 contacts the first signal line 2-1 and can slide freely a small distance. This can effectively reduce the damage to the first contact 4-1 caused by excessive contact force and extend the device life. The size of the connecting beam 6 will change the flexibility of the first contact 4-1. The longer the connecting beam 6, the greater the displacement of the first contact 4-1 in the horizontal plane. The thicker the connecting beam 6, the smaller the displacement of the first contact 4-1. The length of the connecting beam 6 can be set to be less than 10 micrometers, and the cross-sectional area of ​​the connecting beam 6 can be less than 1 / 4 of the cross-sectional area of ​​the first contact 4-1. The specific dimensions are not limited.

[0049] In some embodiments, such as Figure 8 and Figure 9 As shown, the connecting beam 6 includes a first connecting part 6-1, a U-shaped connecting part 6-2, and a second connecting part 6-3 connected in sequence. One end of the first connecting part 6-1 is perpendicularly connected to the cantilever beam 3; the U-shaped connecting part 6-2 is parallel to the substrate 1; and one end of the second connecting part 6-3 is perpendicularly connected to the first contact point 4-1.

[0050] The connecting beam 6 can be a simple column or other complex shapes. The greater the elastic modulus of the connecting beam 6, the greater the movable displacement of the first contact point 4-1. For example... Figure 8 As shown, the connecting beam 6 includes a first connecting part 6-1, a loop-shaped connecting part 6-2, and a second connecting part 6-3 connected sequentially. The specific shape of the loop-shaped connecting part 6-2 can be as follows: Figure 9 As shown, it can also be a simple spiral structure. One end of the first connecting part 6-1 is vertically connected to the cantilever beam 3, the loop-shaped connecting part 6-2 is parallel to the substrate 1, and one end of the second connecting part 6-3 is vertically connected to the first contact 4-1. At this time, the first contact 4-1 has degrees of freedom in both the horizontal and vertical directions. When the cantilever beam 3 is driven down, the first contact 4-1 falls on the first signal line 2-1. When the electrostatic force is too large, the front end of the cantilever beam 3 continues to move downward, while the first contact 4-1 is fixed and cannot move. At this time, the loop-shaped connecting part 6-2 deforms to bear the excess contact force, avoiding damage to the first contact 4-1 due to excessive contact force, thereby extending the device life.

[0051] In some embodiments, such as Figure 11 As shown, the first signal line 2-1 has a second contact 4-2 on the side near the cantilever beam 3. The orthographic projection of the second contact 4-2 on the substrate 1 is a second projection, and the second projection at least partially overlaps with the orthographic projection of the cantilever beam 3 on the substrate 1.

[0052] like Figure 11 As shown, a second contact 4-2 is connected to the upper surface of the first signal line 2-1. The cross-sectional shape of the second contact 4-2 is, for example, rectangular, circular or elliptical, etc., and is not specifically limited. The second contact 4-2 overlaps with the projected portion of the cantilever beam 3, which facilitates the drive electrode 2-2 to control the connection or disconnection of the first signal line 2-1 and the second signal line 2-3. The second contact 4-2 can be set as a flexible contact to avoid rigid contact.

[0053] In some embodiments, the aforementioned connecting beam 6 structure can also be provided between the second contact 4-2 and the first signal line 2-1 to further achieve a flexible contact effect.

[0054] In some embodiments, the first projection coincides with the second projection; or, the first projection covers the second projection; or, the second projection covers the first projection.

[0055] A first contact 4-1 and a second contact 4-2 can be simultaneously set between the first signal line 2-1 and the cantilever beam 3. The dimensions of the first contact 4-1 and the second contact 4-2 can be the same. At this time, the first projection and the second projection coincide. At least one of the first contact 4-1 and the second contact 4-2 is a flexible contact.

[0056] like Figure 12 As shown, when the first contact 4-1 is a flexible contact and the second contact 4-2 is a rigid contact, the first contact 4-1 and the second contact 4-2 are initially facing each other and have the same planar dimensions. When the cantilever beam 3 moves downward under the action of electrostatic force, the two contacts 4 make flexible contact. As a result, the longitudinal dimension of the first contact 4-1 decreases while its lateral dimension increases, becoming larger than the dimension of the second contact 4-2 below. It becomes flat and slightly covers the second contact 4-2, which can effectively avoid the problem of high contact resistance caused by poor contact morphology and collision damage.

[0057] like Figure 13 As shown, when both the first contact 4-1 and the second contact 4-2 are flexible contacts, in the initial state, the first contact 4-1 and the second contact 4-2 face each other and have the same planar dimensions. When the cantilever beam 3 is pulled down, the two contacts 4 make flexible contact. When the cantilever beam 3 is pulled down further, the longitudinal dimension of both contacts 4 will decrease to a certain extent, and the lateral dimension will increase. The contact area will increase to a certain extent, and the tighter contact can better achieve low-resistance connection, further reduce contact resistance, and optimize switching differential performance.

[0058] When the first projection covers the second projection, or the second projection covers the first projection, that is, when the cross-sectional dimensions of the first contact 4-1 and the second contact 4-2 are different, the larger contact 4 will undergo greater elastic deformation. The deformed larger contact 4 can partially cover the smaller contact 4. At this time, the contact area will be further increased than the design value, and a certain amount of misaligned contact redundancy space can be provided to ensure the contact area of ​​the first contact 4-1 and the second contact 4-2, thereby ensuring the device connection effect.

[0059] In some embodiments, such as Figure 11 As shown, the second contact 4-2 is disposed against the insulating layer 5 located on the first signal line 2-1, and the thickness of the second contact 4-2 is greater than or equal to the thickness of the insulating layer 5.

[0060] like Figure 10As shown, due to the step-like undulations in the deposition of insulating layer 5 and the fabrication of contact 4, the step height is mainly caused by the thickness of insulating layer 5, the thickness of the second contact 4-2, and the roughness. The step height ranges from 100nm to 500nm, and the undulations are easily affected by the photolithography alignment accuracy and etching process accuracy. When the upper cantilever beam 3 is pulled down, the contact surface of the lower second contact 4-2 may become uneven, thereby increasing the contact resistance and causing a large switching differential loss. By setting the second contact 4-2 higher than the insulating layer 5, the upper surface of the second contact 4-2 becomes relatively flat, compensating for the height difference caused by the step.

[0061] In some embodiments, such as Figure 11 As shown, the second projection overlaps with the orthographic projection of the insulating layer 5 on the substrate 1.

[0062] When the second contact 4-2 is designed as a flexible contact, its flow characteristics allow its upper surface to be relatively flat. The planar dimensions of the second contact 4-2 simultaneously cover the insulating layer 5 step and the lower portion of the first signal line 2-1. The upper surface of the second contact 4-2 can compensate for the height difference caused by the lower step. Furthermore, the second contact 4-2 is partially covered by the insulating layer 5. Under the action of electrostatic force, the upper cantilever beam 3 shifts downwards and contacts the lower second contact 4-2. The second contact 4-2 can cover the entire first contact 4-1, and its deformable characteristics allow it to conform to the rough and uneven parts of the first contact 4-1, increasing the effective contact area, reducing contact resistance, optimizing switching differential performance, and further ensuring the flatness of the upper surface of the second contact 4-2, thus ensuring the device connection effect.

[0063] In some embodiments, the material of the first contact 4-1 and / or the second contact 4-2 includes a matrix adhesive and liquid metal dispersed in the matrix adhesive, wherein the liquid metal includes one or more of gallium, indium and tin, and the matrix adhesive includes one or more of polydimethylsiloxane adhesive, photoresist, polyimide adhesive and UV-curable adhesive.

[0064] Flexible contacts can be manufactured by adjusting the materials. For example, the material may include a matrix adhesive and liquid metal dispersed in the matrix adhesive. The liquid metal may include one or more metal particles selected from gallium, indium, and tin. The matrix adhesive may include one or more of polydimethylsiloxane adhesive, photoresist, polyimide adhesive, and UV-curable adhesive. Uniformly dispersed metal particles enable electrical connection at contact 4, with a resistance value similar to that of a metal. After curing, the matrix adhesive effectively seals the liquid metal, preventing leakage and contamination, while also allowing contact 4 to be flexible and deformable.

[0065] The flexible contact can be fabricated in the first groove 7-1 by means of a mold after the first groove 7-1 is formed in the sacrificial layer 7.

[0066] When photoresist is selected as the material for flexible contacts, flexible contacts can be fabricated through photolithography, achieving more precise control over pattern dimensions. This eliminates the need for additional steps such as mask fabrication, structure etching, and mask removal, effectively simplifying the process. For example, after fabricating the first groove 7-1 above the sacrificial layer 7, a layer of photoresist dispersed with liquid metal particles is laid flat, and patterning is achieved through photolithography.

[0067] Furthermore, for special application environments requiring flexibility, micro-extension, and micro-deformation, 3D printing can be used to fabricate flexible contacts and cantilever beams 3. Specifically, a flexible conductive colloid is prepared using various synthesis methods, maintaining its flowability at room temperature. This colloid is injected into the printer syringe, and contacts 4 are drawn using 3D printing and then photocured (or thermocured) into a flexible conductor. A second printing process is then performed to draw the cantilever beam 3, adjusting the curing conditions to enhance the curing strength. The final result is a contact switch that is electrically conductive overall, with the contacts 4 remaining flexible while the cantilever beam 3 maintains high rigidity.

[0068] Some embodiments of this application provide an electronic device, including the MEMS device described in any of the above embodiments, which has a stable structure and a long service life.

[0069] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0070] In the embodiments of this application, "film" and "layer" can be interchanged. For example, sometimes "conductive layer" can be replaced with "conductive film". Similarly, sometimes "insulating film" can be replaced with "insulating layer". The scale of the drawings in the embodiments of this application can be used as a reference in actual processes, but is not limited thereto. For example, the aspect ratio of the channel, the thickness and spacing of each film layer can be adjusted according to actual needs. The number of pixels in the array substrate and the number of sub-pixels in each pixel are not limited to the quantities shown in the figures. The drawings described in the embodiments of this application are only structural schematic diagrams, and one method in the embodiments of this application is not limited to the shapes or values ​​shown in the drawings.

[0071] In the embodiments of this application, triangles, rectangles, trapezoids, pentagons, or hexagons are not strictly defined, but can be approximate triangles, rectangles, trapezoids, pentagons, or hexagons, etc., and may have some small deformations due to tolerances, and may have chamfers, curved edges, and other deformations.

[0072] Furthermore, given that details have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that embodiments of this application may be practiced without these details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0073] In some embodiments of this application, a method for fabricating a MEMS device is provided, comprising: forming an electrode layer on one side of a substrate 1, forming a contact 4 on the side of the electrode layer away from the substrate 1, forming a cantilever beam 3 on the side of the contact 4 away from the substrate 1, wherein the cantilever beam 3 is electrically connected to the electrode layer.

[0074] For example Figure 1 The fabrication of the MEMS device shown mainly includes several parts: signal line fabrication, driving electrode 2-2 fabrication, sacrificial layer 7 fabrication, cantilever beam 3 fabrication, and release of sacrificial layer 7. Specifically, it includes the following steps:

[0075] First step, such as Figure 2 As shown, metal is deposited on the clean glass substrate 1 and patterned through photolithography, etching and other steps to prepare the first signal line 2-1, the second signal line 2-3, the driving electrode 2-2, and other ground lines and other connecting lines.

[0076] The second step, as Figure 3 As shown, silicon nitride and other materials are deposited to form an insulating layer 5, and windows are opened at corresponding positions through photolithography and etching processes.

[0077] The third step, as Figure 4 As shown, the deposited contact material is patterned on the first signal line 2-1 to form the second contact 4-2.

[0078] Step four, as Figure 5 As shown, a sacrificial layer 7 is deposited, and the thickness of the sacrificial layer 7 is the gap between the lower surface of the cantilever beam 3 and the upper surface of the first signal line 2-1. The flatness of the sacrificial layer 7 not only directly affects the flatness of the upper cantilever beam 3, but also affects the stress distribution of the cantilever beam 3.

[0079] Step 5: As Figure 5 As shown, a first groove 7-1 and a second groove 7-2 can be formed on the upper surface of the sacrificial layer 7 at a specific position by photolithography, etching and other steps. The first groove 7-1 corresponds to the subsequent first contact 4-1, and the second groove 7-2 corresponds to the subsequent cantilever beam 3.

[0080] Step 6, as Figure 6As shown, for example, a contact material of appropriate thickness is deposited by electroplating, magnetron sputtering or other methods, and patterned to form the first contact 4-1. Then, a cantilever beam material of appropriate thickness is deposited and patterned to form the cantilever beam 3.

[0081] Step 7, as Figure 1 As shown, this step involves removing the sacrificial layer 7 to allow the cantilever beam 3 to be suspended above the first signal line 2-1, thus forming the final switch structure.

[0082] The "patterning process" described in this application includes, for metallic, inorganic, or transparent conductive materials, processes such as photoresist coating, mask exposure, development, etching, and photoresist stripping; for organic materials, it includes processes such as organic material coating, mask exposure, and development. Deposition can be performed using any one or more of sputtering, evaporation, and chemical vapor deposition; coating can be performed using any one or more of spraying, spin coating, and inkjet printing; and etching can be performed using any one or more of dry and wet etching, without limitation.

[0083] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0084] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, well-known power / ground connections to other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be illustrated in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that the embodiments of this application may be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0085] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. The embodiments of this application are intended to cover all such substitutions, modifications, and variations falling within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A MEMS device, characterized in that, include: Substrate; An electrode layer is disposed on one side of the substrate and includes a first signal line, a driving electrode, and a second signal line arranged sequentially at intervals. A cantilever beam is located on the side of the electrode layer away from the substrate and is spaced apart from the driving electrode. One end of the cantilever beam is electrically connected to the second signal line, and the other end is spaced apart from the first signal line. The orthographic projection of the cantilever beam on the substrate overlaps with the orthographic projection of the first signal line on the substrate. A contact is provided at one end of the first signal line near the cantilever beam, and / or at one end of the cantilever beam near the first signal line, for connecting or disconnecting the cantilever beam and the first signal line under the control of the driving electrode, and at least one of the contacts is a flexible contact.

2. The MEMS device according to claim 1, characterized in that, An insulating layer is provided on the side of the electrode layer away from the substrate. The insulating layer covers the driving electrode and partially covers the first signal line and the second signal line.

3. The MEMS device according to claim 2, characterized in that, The cantilever beam has a first contact point on the side near the first signal line. The orthographic projection of the first contact point on the substrate is a first projection, and the first projection at least partially overlaps with the orthographic projection of the first signal line on the substrate.

4. The MEMS device according to claim 3, characterized in that, A connecting beam connects the first contact point and the cantilever beam, and the first projection covers the orthogonal projection of the connecting beam on the substrate.

5. The MEMS device according to claim 4, characterized in that, The connecting beam includes a first connecting part, a U-shaped connecting part, and a second connecting part connected in sequence. One end of the first connecting part is perpendicularly connected to the cantilever beam; the U-shaped connecting part is parallel to the substrate; and one end of the second connecting part is perpendicularly connected to the first contact point.

6. The MEMS device according to claim 3, characterized in that, The first signal line has a second contact on the side near the cantilever beam. The orthographic projection of the second contact on the substrate is a second projection, and the second projection at least partially overlaps with the orthographic projection of the cantilever beam on the substrate.

7. The MEMS device according to claim 6, characterized in that, The first projection coincides with the second projection; or the first projection covers the second projection; or the second projection covers the first projection.

8. The MEMS device according to claim 6, characterized in that, The second contact is disposed against the insulating layer located on the first signal line, and the thickness of the second contact is greater than or equal to the thickness of the insulating layer.

9. The MEMS device according to claim 8, characterized in that, The second projection overlaps with the orthographic projection of the insulating layer on the substrate.

10. The MEMS device according to claim 6, characterized in that, The material of the first contact and / or the second contact includes a matrix adhesive and a liquid metal dispersed in the matrix adhesive, wherein the liquid metal includes one or more of gallium, indium and tin, and the matrix adhesive includes one or more of polydimethylsiloxane adhesive, photoresist, polyimide adhesive and UV-curable adhesive.

11. A method for fabricating a MEMS device as described in any one of claims 1-10, characterized in that, include: An electrode layer is formed on one side of a substrate, a contact is formed on the side of the electrode layer away from the substrate, and a cantilever beam is formed on the side of the contact away from the substrate, the cantilever beam being electrically connected to the electrode layer.

12. An electronic device, characterized in that, Includes the MEMS device described in any one of claims 1-10.

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