Large-deflection cantilever beam structure

Abstract

A large-deflection cantilever beam structure disclosed by the present invention comprises a cantilever beam plate, the two ends of the cantilever beam plate are respectively a fixed end and a free end, and the part between the fixed end and the free end is the effective length of the cantilever beam plate. At least one groove is formed in at least one of the upper surface and the lower surface of the cantilever beam plate in the length direction, the rest part of the side edge of the groove is a ridge part, and the cantilever beam plate is connected with a driving part through the fixed end. The groove structure is additionally arranged on the cantilever beam plate, so that the deflection and the inclination angle of the free end of the cantilever beam plate can be increased on the premise of not increasing the length of the cantilever beam plate, the cantilever beam plate does not need to be designed into a complex structure, and the design difficulty is reduced.

Description

Technical Field

[0001] The present invention relates to the field of MEMS devices, and in particular to a large-deflection cantilever beam structure. Background Art

[0002] The basic structural units commonly used in MEMS devices include microcantilever beams, squares, plates, disks, films, and comb teeth. Among them, the microcantilever beam structure has the advantages of small size, fast response, high sensitivity, simple process, and flexible structure, making it the most widely used and most promising basic structure in the MEMS field.

[0003] Microcantilever structures are a widely used basic structural unit in MEMS devices, with scales ranging from nanometers to micrometers. Microcantilever structures include rectangular, T-shaped, U-shaped, triangular, and tuning fork shapes, with the rectangular beam structure being the most commonly used.

[0004] When a MEMS cantilever beam structure is used as an actuator, the change in deflection at its free end is usually one of the important indicators for measuring its actuation capability. Under the same driving conditions, the greater the deflection and inclination angle of the cantilever beam's free end, the stronger the actuation capability. The free end deflection is proportional to the length of the cantilever beam and inversely proportional to its thickness. Considering the overall size of the MEMS device, the length of the cantilever arm cannot be extended indefinitely, and considering the MEMS manufacturing process, the thickness of the cantilever arm cannot be reduced indefinitely. There are already a variety of special-shaped cantilever beam designs, such as triangular and trapezoidal cantilever beam structures, to increase the deflection of the cantilever beam's free end, but the effect is poor and the design is difficult, requiring simulation to implement. In addition, there are many variables, which increases the design difficulty and makes it difficult to model and standardize. Summary of the Invention

[0005] In order to solve all or part of the problems in the above-mentioned prior art, the present invention provides a large-deflection cantilever beam structure.

[0006] To achieve the above objectives, the present invention provides a large-deflection cantilever beam structure, comprising a cantilever beam plate, wherein the cantilever beam plate has a fixed end and a free end at each end, the portion between the fixed end and the free end being the effective length of the cantilever beam plate, at least one of the upper and lower surfaces of the cantilever beam plate in the longitudinal direction being provided with at least one groove, the remaining portion of the side edge of the groove being a ridge, and the cantilever beam plate being connected to a driving member via the fixed end. It is known that the deflection of the free end of a cantilever beam plate is proportional to the length of the cantilever beam plate. When the deflection of the free end needs to be increased, the length of the cantilever beam plate is generally increased directly. However, the length of the cantilever beam plate cannot be extended indefinitely due to the overall size of the MEMS device, or the cantilever beam plate is designed into a complex structure, which increases the design difficulty and makes modeling and standardization difficult. The present invention, by adding a groove structure to the cantilever beam plate, can increase the deflection of the free end of the cantilever beam plate without increasing the length of the cantilever beam plate, and does not require the cantilever beam plate to be designed into a complex structure, thereby reducing the design difficulty.

[0007] The number of the groove is one, and the ridge is close to the fixed end and / or the free end.

[0008] The lower surface of the cantilever beam plate in the length direction is provided with a plurality of grooves at intervals. When there are a plurality of grooves, the ridge portion includes not only a portion close to the fixed end and / or the free end but also a portion between two adjacent grooves.

[0009] The opening widths of the grooves are the same. When there are multiple grooves, the opening widths of each groove are the same.

[0010] The opening widths of the grooves are different. When there are multiple grooves, the opening widths of each groove are different.

[0011] The depths of the grooves are the same. When there are multiple grooves, the depth of each groove is the same.

[0012] The depths of the grooves are different. When there are multiple grooves, the depths of the grooves are different.

[0013] The widths of the ridges are the same. When there are multiple grooves, the widths of the grooves are the same.

[0014] The widths of the ridges are different. When there are multiple grooves, the widths of the grooves are different.

[0015] The cantilever beam plate is a folded multi-stage structure, and the sum of the effective lengths of the multi-stage structure is equal to the effective length of the cantilever beam plate before folding. By folding the cantilever beam plate, the overall length of the cantilever beam plate can be reduced, thereby meeting the overall size miniaturization requirements of the MEMS device.

[0016] The multi-level structure is any one of a Z-shaped structure, a circle structure or a square-circle structure.

[0017] The cantilever beam plate is any one of a rectangular plate or a special-shaped plate. The groove structure is not only applicable to rectangular cantilever beam plates, but also to special-shaped cantilever beam plates such as triangles and trapezoids. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a schematic diagram of a large deflection cantilever beam structure provided by Example 1 of the present invention, wherein the ridge is provided near the free end;

[0020] Figure 2 This is a schematic diagram of a large deflection cantilever beam structure provided by Example 1 of the present invention, wherein the ridge is arranged close to the fixed end;

[0021] Figure 3 This is a schematic diagram of a large deflection cantilever beam structure provided by Example 1 of the present invention, wherein the ridge is provided near the fixed end and the free end;

[0022] Figure 4 This is a schematic diagram of a large deflection cantilever beam structure provided by Example 2 of the present invention;

[0023] Figure 5 This is a schematic diagram of a large deflection cantilever beam structure provided by Example 6 of the present invention;

[0024] Figure 6-8 This is a schematic diagram of a large deflection cantilever beam structure provided in Example 13 of the present invention.

[0025] Reference numerals:

[0026] 1. Cantilever beam plate; 2. Fixed end; 3. Free end; 4. Groove; 5. Driving member; 6. Ridge; 61. Ridge on the side close to the fixed end; a represents the groove opening width; b represents the ridge width; h represents the groove depth; A represents the width of the ridge 61. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the present invention more apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the present invention shown in and described with reference to the accompanying drawings are merely exemplary, and the present invention is not limited to these embodiments.

[0028] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, the accompanying drawings only show structures and / or processing steps closely related to the solutions according to the present invention, while other details that are not closely related to the present invention are omitted.

[0029] Furthermore, in the description of the present invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" indicate positions or relationships based on those shown in the accompanying drawings. These terms are used solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] Example 1

[0031] The present invention provides a large-deflection cantilever beam structure, comprising a cantilever beam plate 1 having a fixed end 2 and a free end 3 at each end. The portion between the fixed end 2 and the free end 3 represents the effective length of the cantilever beam plate 1. A groove 4 is provided on the lower surface of the cantilever beam plate 1 in the longitudinal direction. The remaining portion of the side of the groove 4 is a ridge 6. The fixed end 2 of the cantilever beam plate 1 is connected to a driving member 5. The ridge 6 can be located near the free end 3, near the fixed end 2, or near one end 3 and the other end 2.

[0032] Specifically, such as Figure 1 As shown, the cantilever beam structure has only one ridge 6, and the ridge 6 is arranged close to the free end 3. Figure 2 As shown, the cantilever beam structure has only one ridge 6, and the ridge 6 is arranged close to the fixed end 2. Figure 3 As shown, the cantilever beam structure has two ridges 6 , one near the free end 3 and the other near the fixed end 2 .

[0033] In this embodiment, the groove 4 is provided on the lower surface of the cantilever beam plate in the length direction. In other embodiments, the groove 4 may be provided on the upper surface of the cantilever beam plate in the length direction, or grooves 4 may be provided on both the upper and lower surfaces.

[0034] Example 2

[0035] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 1, except that there are multiple grooves, and the number of grooves in this embodiment is 3, and the ridge 6 is located between two adjacent grooves 4 and on one side of the free end 3.

[0036] Specifically, such as Figure 4 As shown, the cantilever beam plate 1 has a length of 40 mm and a thickness of 40 μm. The width a of the opening of the groove 4 is 0.125 mm, the depth h is 20 μm, and the width b of the ridge 6 is 20 μm. In this embodiment, the cantilever beam plate 1 is a rectangular plate, and the cross-sectional shape of the groove 4 is rectangular. In other embodiments, the cantilever beam plate 1 can be designed as a triangle, trapezoid, or other special-shaped shape, and the cross-sectional shape of the groove 4 can be a triangle, trapezoid, circular arc, or other irregular shape. In this embodiment, the grooves 4 are evenly arranged on the cantilever beam plate 1, and the opening size and depth of each groove 4 are the same, and the width of each ridge 6 is also the same. In other embodiments, the opening size, depth, and width of each groove 4 and the ridge 6 can be set to different situations.

[0037] Example 3

[0038] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 2, except that the width of the opening of the groove 4 is different. In this embodiment, the opening width a of the groove 4 is 0.25 mm.

[0039] Example 4

[0040] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 2, except that the width of the opening of the groove 4 is different. In this embodiment, the opening width a of the groove 4 is 0.5 mm.

[0041] Example 5

[0042] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 2, except that the width of the opening of the groove 4 is different. In this embodiment, the opening width a of the groove 4 is 1 mm.

[0043] The cantilever beam structures in Examples 2-5 were tested respectively, and the obtained free end inclination angle, characteristic frequency and free end deflection data are shown in Table 1:

[0044] Table 1

[0045]

[0046] It is known that the free end inclination angle of the cantilever beam with a top silicon of 40 mm is 1.45762838°, the characteristic frequency is 499 Hz, and the free end deflection is 98 μm. Combined with the data in Table 1, it can be seen that the free end deflection of the cantilever beam of Examples 2-5 is greatly improved compared with the cantilever beam with a top silicon of 40 mm, indicating that the purpose of increasing the free end deflection of the cantilever beam plate can be achieved by adding a groove structure to the cantilever beam plate without increasing the length of the cantilever beam plate.

[0047] Example 6

[0048] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 2, except that there is a ridge 6 on the side of the fixed end 2 close to the cantilever beam plate 1. To distinguish it from other ridges, the ridge here is recorded as ridge 61.

[0049] Specifically, such as Figure 5 As shown, in this embodiment, the width A of the ridge 61 is 1.5 mm, the width a of the opening of the groove 4 is 5 mm, the depth h is 20 μm, and the width b of the ridge 6 is 20 μm. In this embodiment, the surface of the ridge 61 is flat. In other embodiments, its surface can also be designed as a curved surface or other shapes according to process requirements.

[0050] Example 7

[0051] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 5, except that the width A of the ridge 61 is different. In this embodiment, the width A of the ridge 61 is 3.5 mm.

[0052] Example 8

[0053] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 5, except that the width A of the ridge 61 is different. In this embodiment, the width A of the ridge 61 is 5 mm.

[0054] The cantilever beam structures in Examples 6-8 were tested respectively, and the obtained free end inclination angle, characteristic frequency and free end deflection data are shown in Table 2:

[0055] Table 2

[0056]

[0057] From Table 2, it can be seen that when the width A of the ridge 61 is 1.5 mm (Example 6) and 3.5 mm (Example 7), the deflection of the free end of the cantilever beam is greatly improved compared with the cantilever beam with top silicon of 40 mm, but the difference between the characteristic frequency and the characteristic frequency of the cantilever beam with top silicon of 40 mm is too large. In Example 8, when the width A of the ridge 61 is 5 mm, the characteristic frequency of the cantilever beam is 490 Hz, which is very close to the characteristic frequency of the cantilever beam with top silicon of 40 mm, but the deflection of its free end is significantly improved. This shows that on the basis of setting a groove structure on the cantilever beam plate, by designing the width of the ridge 61, it is possible to ensure that the characteristic frequency of the cantilever beam plate meets the use requirements while improving the deflection of the free end of the cantilever beam plate.

[0058] Example 9

[0059] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 8, except that the opening width a of the groove 4 is different. In Example 8, the opening width a of the groove 4 is 5 mm, and in this embodiment, the opening width a of the groove 4 is 20 μm.

[0060] Example 10

[0061] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 9, except that the opening width a of the groove 4 is different. In this embodiment, the opening width a of the groove 4 is 40 μm.

[0062] Example 11

[0063] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 9, except that the opening width a of the groove 4 is different. In this embodiment, the opening width a of the groove 4 is 60 μm.

[0064] Example 12

[0065] This embodiment provides a large deflection cantilever beam structure, which is basically the same as the large deflection cantilever beam structure described in Example 9, except that the opening width a of the groove 4 is different. In this embodiment, the opening width a of the groove 4 is 80 μm.

[0066] The cantilever beam structures in Examples 9-12 were tested respectively, and the obtained free end inclination angle, characteristic frequency and free end deflection data are shown in Table 3:

[0067] Table 3

[0068]

[0069] Examples 9 to 12 represent the situation where groove structures with different opening widths a are set on the cantilever beam plate when the width of the limiting portion is 5 mm. Combined with Table 3, it can be seen that the characteristic frequencies of Examples 9 to 12 are very close to the characteristic frequencies of the cantilever beam with a top silicon of 40 mm, and the free end deflection is greatly improved compared to 98 μm, achieving the technical effect of ensuring the characteristic frequency of the cantilever beam plate while improving the deflection of the free end of the cantilever beam plate.

[0070] Example 13

[0071] This embodiment provides a large deflection cantilever beam structure, wherein the large deflection cantilever beam described in any one of embodiments 1 to 12 is folded, and the sum of the effective lengths of the folded multi-stage structure is equal to the effective length of the cantilever beam plate before folding. This embodiment designs the cantilever beam into a multi-stage structure, which can reduce the overall length of the cantilever beam while ensuring the deflection requirements of the cantilever beam structure, thereby meeting the overall size miniaturization requirements of the MEMS device. The multi-stage structure can be formed by folding the same cantilever beam structure as a whole, or by splicing multiple cantilever beam structures. As long as the effective length of the multi-stage structure formed after folding is equal to the effective length of the cantilever beam plate before folding, it is possible to improve the deflection of the cantilever beam structure while reducing the overall length of the cantilever beam, thereby meeting the overall size miniaturization requirements of the MEMS device.

[0072] Specifically, in this embodiment, Figure 6 As shown, the multi-level structure can be in a Z-shape. Figure 6 The gray part in the figure represents the effective length of the multi-level structure, which can also be a circle structure ( Figure 7 ) or square circle structure ( Figure 8 ), Figure 6-8 In the figure, the number of stages of the multi-stage structure is only for illustration, and the specific number can be flexibly adjusted as needed.

[0073] In addition, it should be noted that, in this specification, "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0074] It should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A large deflection cantilever beam structure, characterized in that: It includes a cantilever beam plate, wherein the two ends of the cantilever beam plate are a fixed end and a free end respectively, the portion between the fixed end and the free end is the effective length of the cantilever beam plate, at least one of the upper surface and the lower surface in the length direction of the cantilever beam plate is provided with at least one groove, the remaining part of the side of the groove is a ridge, and the cantilever beam plate is connected to the driving member through the fixed end.

2. The large deflection cantilever beam structure according to claim 1, characterized in that: The number of the groove is one, and the ridge is close to the fixed end and / or the free end.

3. The large deflection cantilever beam structure according to claim 1, characterized in that: A plurality of grooves are arranged at intervals on the lower surface of the cantilever beam plate in the length direction.

4. The large deflection cantilever beam structure according to claim 3, characterized in that: The opening widths of the grooves are the same.

5. The large deflection cantilever beam structure according to claim 3, characterized in that: The opening widths of the grooves are different.

6. The large deflection cantilever beam structure according to claim 3, characterized in that: The grooves have the same depth.

7. The large deflection cantilever beam structure according to claim 3, characterized in that: The grooves have different depths.

8. The large deflection cantilever beam structure according to claim 3, characterized in that: The ridges have the same width.

9. The large deflection cantilever beam structure according to claim 3, characterized in that: The ridges have different widths.

10. A large deflection cantilever beam structure according to any one of claims 1 to 9, characterized in that: The cantilever beam plate is a folded multi-stage structure, and the sum of the effective lengths of the multi-stage structure is equal to the effective length of the cantilever beam plate before folding.

11. The large deflection cantilever beam structure according to claim 11, characterized in that: The multi-level structure is any one of a Z-shaped structure, a circle structure or a square-circle structure.

12. The large deflection cantilever beam structure according to claim 1, characterized in that: The cantilever beam plate is any one of a rectangular plate and a special-shaped plate.

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