Micromechanical thin film structure of MEMS device and MEMS device

Abstract

The present invention discloses a micromechanical film structure of a MEMS device and a MEMS device. The micromechanical film structure comprises: a substrate; an anchor seat, which is arranged on the substrate; and an elastic film assembly, which comprises a film component and a stress absorbing component, which is arranged on the film component to absorb the stress that causes the creep of the film component, and one of the film component and the stress absorbing component is arranged on the anchor seat. The present invention releases or evenly processes the concentrated stress on the elastic film assembly by arranging the stress absorbing component to absorb the stress that causes the creep of the film component, thereby improving the anti-creep characteristics and avoiding the performance drift of the MEMS device.

Description

Technical Field

[0001] The present invention relates to the field of parts of MEMS devices, and in particular to a micromechanical film structure of a MEMS device and a MEMS device. Background Art

[0002] Micromechanical thin film structures are typical components in MEMS (micro-electromechanical systems) devices, and are often used for structural driving, signal sensing, etc. Micromechanical thin film structures are generally made of metal materials or non-metallic materials. For these materials (especially metal materials), when they are subjected to mechanical stress during operation, due to their creep characteristics, MEMS devices will gradually produce irreversible deformations, causing the performance of MEMS devices to drift, and in severe cases even causing MEMS devices to fail.

[0003] In order to alleviate the creep deterioration of the structure, the industry generally uses high-strength new creep-resistant materials to improve performance; however, this method requires the development and evaluation of new materials, which has a long cycle and high risks, and the development results have a certain degree of unpredictability. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a micro-mechanical film structure of a MEMS device to improve the anti-creep property.

[0005] The present invention also provides a MEMS device using the micromechanical film structure to improve anti-creep properties.

[0006] A micromechanical film structure of a MEMS device according to an embodiment of the present invention includes: a substrate; an anchor seat, which is arranged on the substrate; an elastic film assembly, which includes a film part and a stress absorbing part, which is arranged on the film part to absorb the stress that causes creep of the film part, and one of the film part and the stress absorbing part is arranged on the anchor seat.

[0007] According to the micromechanical film structure of the MEMS device of the embodiment of the present invention, a stress absorber is provided to absorb the stress causing creep of the film component, so that the concentrated stress on the elastic film component is released or uniformly processed, thereby improving the anti-creep characteristics and avoiding the performance drift of the MEMS device.

[0008] In some embodiments, the stress absorber has an absorption space, and a transition fillet is provided on the circumferential wall of the absorption space. The film member can transmit force to the stress absorber to cause the absorption space of the stress absorber to deform and absorb the stress.

[0009] Furthermore, the absorption space is a closed space or an open space with an opening.

[0010] Furthermore, the open space includes one or more subspaces. When the open space includes a plurality of subspaces, the openings of any two adjacent subspaces face in opposite directions.

[0011] Specifically, the stress absorbing member includes a main body portion, on which the subspace is formed, wherein when the open space includes a plurality of the subspaces, the main body portion includes a bent portion and a connecting portion, there are a plurality of bent portions, each of which has the subspace formed thereon, an end portion of any two adjacent bent portions being arranged in the opening of the other, and the ends of any two adjacent bent portions being connected via the connecting portion.

[0012] In some embodiments, the film member is configured as a beam or a film.

[0013] Specifically, the beam body includes a plurality of split beams, and the stress absorber is provided between any two adjacent split beams, the stress absorber includes a main body portion and receiving portions provided at both ends of the main body portion, the absorption space is formed on the main body portion, and the receiving portions at both ends of the main body portion are respectively connected to the two adjacent split beams.

[0014] More specifically, at least one of the head and tail ends of the plurality of split beams is connected to the anchor seat.

[0015] In some specific embodiments, a plurality of stress absorbers are provided around the film, and the stress absorbers include a main body and receiving parts provided at both ends of the main body, the absorption space is formed on the main body, the receiving part at one end of the main body is connected to the anchor seat, and the receiving part at the other end is connected to the film.

[0016] A MEMS device according to an embodiment of the present invention includes the above-mentioned micromechanical film structure.

[0017] According to the MEMS device of the embodiment of the present invention, a stress absorber is provided to absorb the stress causing creep of the film component, so that the concentrated stress on the elastic film component is released or uniformly processed, thereby improving the anti-creep property and avoiding the performance drift of the MEMS device.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 A schematic diagram of a structure in which a micro-mechanical film structure has two split beams in an embodiment of the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the micro-mechanical film structure having three split beams in an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of the structure of a micro-mechanical film structure having two beams in an embodiment of the present invention;

[0023] Figure 4 It is a schematic structural diagram of a micro-mechanical thin film structure with a mass block in an embodiment of the present invention;

[0024] Figure 5 It is a schematic structural diagram of a stress absorbing member in a first embodiment of the present invention;

[0025] Figure 6 It is a schematic structural diagram of a stress absorbing member in a second embodiment of the present invention;

[0026] Figure 7 It is a schematic structural diagram of a stress absorbing member in a third embodiment of the present invention;

[0027] Figure 8 is a schematic structural diagram of a stress absorbing member in a fourth embodiment of the present invention;

[0028] Fig. 9 is a schematic diagram of a stress absorber applied to a beam body in a fourth embodiment of the present invention;

[0029] Fig.10 FIG. 1 is a schematic diagram of a stress absorber applied to a film in a third embodiment of the present invention.

[0030] Reference numerals:

[0031] 100. Micromechanical thin film structures;

[0032] 10. substrate; 20. anchor seat;

[0033] 30. Elastic film assembly; 311. Beam body; 3111. Split beam; 312. Film; 32. Stress absorber; 321. Absorption space; 322. Transition fillet; 323. Main body; 3231. Bending part; 3232. Connecting part; 324. Receiving part; 40. Mass block. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0036] In addition, features defined as “first” or “second” may explicitly or implicitly include one or more such features, and are used to distinguish and describe features, without any distinction in order or importance.

[0037] In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] The micromechanical thin film structure 100 according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0040] like Figure 1 As shown, a micro-mechanical film structure 100 according to an embodiment of the present invention includes: a substrate 10 , an anchor seat 20 and an elastic film assembly 30 .

[0041] The anchor seat 20 is arranged on the substrate 10. The material of the substrate 10 includes but is not limited to silicon, glass, quartz and the like.

[0042] The elastic film assembly 30 includes a film member and a stress absorbing member 32, wherein the stress absorbing member 32 is disposed on the film member to absorb the stress that causes the film member to creep, and one of the film member and the stress absorbing member 32 is disposed on the anchor seat 20. For example, the film member is disposed on the anchor seat 20; or, the stress absorbing member 32 is disposed on the anchor seat 20.

[0043] During the operation of the MEMS device, due to the influence of temperature, time and pressure, the elastic film component 30 will creep. For example, if the elastic film component 30 is a double-end clamped beam, the middle position of the double-end clamped beam will sag, thereby changing the working state of the MEMS device, affecting the performance of the MEMS device, and seriously causing the failure of the MEMS device. The present invention provides a stress absorber 32 to absorb the stress that causes creep, release or homogenize the concentrated stress on the elastic film component 30, thereby improving the anti-creep characteristics of the MEMS device.

[0044] According to the micromechanical film structure 100 of the embodiment of the present invention, the stress absorbing member 32 is provided to absorb the stress causing the creep of the film component, so that the concentrated stress on the elastic film component 30 is released or uniformly processed, thereby improving the anti-creep property and avoiding the performance drift of the MEMS device.

[0045] like Figure 5 , Figure 6 As shown, in some embodiments, the stress absorber 32 has an absorption space 321, and a transition fillet 322 is provided on the circumferential wall of the absorption space 321. The film member can transmit force to the stress absorber 32 to cause the absorption space 321 of the stress absorber 32 to deform and absorb stress. The transition fillet 322 is provided to avoid stress concentration, thereby improving the anti-creep property. The stress absorber 32 is provided on the film member and absorbs the stress that causes the creep of the film member through deformation. The deformation of the absorption space 321 on the stress absorber 32 means that the stress absorber 32 is deformed, thereby absorbing the stress. Among them, the force on the film member is transmitted to the stress absorber 32, and stress also exists on the stress absorber 32. The transition fillet 322 on the stress absorber 32 avoids the concentration of stress at the transition fillet 322, thereby improving the anti-creep property.

[0046] like Figures 5 to 8 As shown, further, the absorption space 321 is a closed space or an open space with an opening. For example, the absorption space 321 is a closed space, and the air in the closed space is used to further improve the anti-creep property; or the absorption space 321 is an open space with an opening to facilitate the transmission of force.

[0047] like Figure 5 , Figure 6 and Figure 7As shown, specifically, the stress absorber 32 has a hollow portion, and a closed space is provided on the hollow portion. It should be noted that the closed space on the hollow portion does not mean that the space is closed, but means that there are restrictions on all sides of the space. For example, the shape of the stress absorber 32 is rectangular, and the rectangular stress absorber 32 restricts a rectangular closed space. The shape of the stress absorber 32 can also be circular or elliptical. The circular stress absorber 32 restricts a circular closed space, and the elliptical stress absorber 32 restricts an elliptical closed space.

[0048] like Figure 8 As shown, further, the open space includes one or more subspaces. When the open space includes multiple subspaces, the openings of any two adjacent subspaces are oriented in opposite directions. By setting the openings of any two adjacent subspaces in opposite directions, the stress absorber 32 can be deformed in different directions when subjected to stress, thereby avoiding excessive deformation of the stress absorber 32 in the same direction to cause creep, and further improving the anti-creep property. The multiple subspaces can be two subspaces, three subspaces, or four subspaces, which are not limited here.

[0049] For example, the open space includes two subspaces, and the two subspaces are arranged left and right, with the opening of the left subspace facing rearward and the opening of the right subspace facing forward, so as to absorb the corresponding stress.

[0050] like Figure 8 As shown, specifically, the stress absorber 32 includes a main body portion 323, and a subspace is formed on the main body portion 323, wherein when the open space includes multiple subspaces, the main body portion 323 includes a bent portion 3231 and a connecting portion 3232, there are multiple bent portions 3231, and a subspace is formed on each bent portion 3231, and the end of any two adjacent bent portions 3231 is arranged in the opening of the other, and the ends of any two adjacent bent portions 3231 are connected by the connecting portion 3232, and the anti-creep characteristics are further improved by arranging the bent portions 3231 and the connecting portions 3232.

[0051] For example, Figure 8As shown, there are two subspaces, which are arranged in a staggered manner from left to right, there are two curved parts 3231, which are adjacent to each other from left to right, the subspace formed by the left curved part 3231 opens to the rear, and the subspace formed by the right curved part 3231 opens to the front, the right end of the left curved part 3231 is located at the opening of the right subspace, and the left end of the right curved part 3231 is located at the opening of the left subspace, and the right end of the right curved part 3231 is located at the opening of the left subspace, and the right end of the left curved part 3231 is connected to the left end of the right curved part 3231. The left end of the connecting part 3232 is connected to the left end of the right curved part 3231, and the right end of the connecting part 3232 is connected to the right end of the left curved part 3231, so that the main body 323 can fully absorb stress and avoid creep caused by stress concentration. Among them, the curved part 3231 can be arc-shaped, or semicircular, and of course, it can also be other curved shapes to avoid stress concentration, which will not be repeated here. Of course, there may be more subspaces, for example, three, four or more subspaces, which will not be described in detail here.

[0052] like Figures 1 to 10 As shown, in some embodiments, the thin film member is constructed as a beam 311 or a thin film 312. By constructing the thin film member as the beam 311 or the thin film 312, it is used for structural driving and signal sensing, and the effect of the micromechanical thin film structure 100 is fully exerted. For example, the thin film member is the beam 311. It can be understood that the beam 311 of the MEMS device is relatively thin and small, and can be used as a long thin film member. The thin film member can be a single double-end fixed beam, such as Figures 1 to 4 As shown, it can also be double-end fixed beams, three double-end fixed beams, or more double-end fixed beams. Of course, the film member can also be a single-end fixed beam, which will not be described here. Fig.10 As shown, the film element is a film 312, and the film 312 can be a circular film 312 for fully exerting the effect. Existing MEMS devices usually include a beam and a film 312 structure, such as RF MEMS switch devices and MEMS acoustic devices. The present invention improves versatility by constructing the film element as a beam 311 or a film 312.

[0053] like Figure 8 , Fig. 9As shown, specifically, the beam body 311 includes a plurality of split beams 3111, and a stress absorber 32 is provided between any two adjacent split beams 3111, the stress absorber 32 includes a main body 323 and receiving parts 324 provided at both ends of the main body 323, an absorption space 321 is formed on the main body 323, and the receiving parts 324 at both ends of the main body 323 are respectively connected to two adjacent split beams 3111, by arranging a plurality of split beams 3111, a stress absorber 32 is provided between two adjacent split beams 3111, and the plurality of stress absorbers 32 can fully absorb stress, avoid stress concentration, and make the stress on the micro-mechanical film structure 100 be uniformly processed.

[0054] like Figure 1 , Figure 3 As shown, for example, there are two split beams 3111, and a stress absorber 32 is disposed between the two split beams 3111, wherein the split beams 3111 can be symmetrically disposed, and the stress absorber 32 is disposed in the middle, so as to further evenly distribute the stress on the micromechanical film structure 100; or Figure 2 As shown, there are three split beams 3111, and a stress absorber 32 is provided between two adjacent split beams 3111, wherein the two stress absorbers 32 can be symmetrical about the spatial center of the split beams 3111, thereby further releasing the stress on the micromechanical film structure 100. Of course, there can be more split beams 3111, which will not be described in detail here.

[0055] More specifically, at least one of the head and tail ends of the multiple split beams 3111 is connected to the anchor seat 20. By arranging at least one of the head and tail ends of the multiple split beams 3111 to be connected to the anchor seat 20, the elastic film assembly 30 is supported to ensure stability. For example, there are three split beams 3111, and the head and tail ends of the split beams 3111 are the left end and the right end respectively. The split beam 3111 at the left end can be connected to the anchor seat 20 to form a single-end fixed beam, or the split beam 3111 at the right end can be connected to the anchor seat 20 to form a single-end fixed beam, or the split beams 3111 at both ends can be connected to the anchor seat 20 to form a double-end fixed beam. Of course, there can also be two, four, five or more split beams 3111, and the situation is the same, which will not be repeated here.

[0056] like Figure 4 As shown, the micromechanical film structure 100 further includes a mass block 40, which is disposed on the film member. The mass block 40 is provided to reduce noise, avoid interference, and improve accuracy. For example, there are three split beams 3111, which are disposed on the left, middle, and right sides, and the mass block 40 is disposed on the middle split beam 3111.

[0057] like Fig.10As shown, in some specific embodiments, a plurality of stress absorbers 32 are provided around the film 312, and the stress absorbers 32 include a main body 323 and receiving portions 324 provided at both ends of the main body 323, an absorption space 321 is formed on the main body 323, the receiving portion 324 at one end of the main body 323 is connected to the anchor seat 20, and the receiving portion 324 at the other end is connected to the film 312. By providing a plurality of stress absorbers 32 around the film 312, the stress can be fully absorbed to avoid the stress being concentrated on the film 312 to cause creep.

[0058] like Fig.10 As shown, specifically, the shape of the anchor seat 20 is frame-shaped, and the film 312 is arranged at the center of the frame-shaped anchor seat 20, so that the stress on the film 312 can be fully transferred to the anchor seat 20, thereby preventing the film 312 from creeping.

[0059] In some embodiments, the elastic membrane component 30 uses creep-resistant materials, such as Ni-based and / or cobalt (Co)-based superalloys, Ni-W alloys, Ni-Mn alloys, gold containing a small amount of Ni and / or Co, W, intermetallic compounds, materials subjected to solid solution and / or secondary phase reinforcement, and materials with a crystal structure that inhibits plastic deformation, such as a hexagonal structure or material with low stacking fault energy. Other binary alloys including any combination of Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Ag, Ta and W are also possible.

[0060] Combine the following Figure 1 and Figure 5 , describing a specific embodiment of the micromechanical thin film structure 100 of the present invention.

[0061] A micromechanical film structure 100 includes a substrate 10 , an anchor seat 20 , an elastic film assembly 30 and a mass block 40 .

[0062] The material of the substrate 10 is silicon. Anchor seats 20 are arranged on the substrate 10, and there are two anchor seats 20, which are spaced apart from each other.

[0063] The elastic film assembly 30 includes a film member and a stress absorbing member 32. The film member is a beam body 311. The beam body 311 includes two split beams 3111. The two split beams 3111 are distributed left and right. The split beam 3111 at the left end is connected to the anchor seat 20 at the left end, and the split beam 3111 at the right end is connected to the anchor seat 20 at the right end. The stress absorbing member 32 is arranged between the two split beams 3111. The stress absorbing member 32 includes a main body 323 and receiving portions 324 arranged at both ends of the main body 323. The receiving portions 324 at both ends of the main body 323 are respectively connected to the two adjacent split beams 3111. The main body 323 is rectangular, and a hollow portion is provided on the main body 323. The hollow portion has a rectangular closed space, and a transition fillet 322 is provided on the circumferential wall of the closed space.

[0064] A MEMS device according to an embodiment of the present invention includes the above-mentioned micromechanical film structure 100 .

[0065] According to the MEMS device of the embodiment of the present invention, the stress absorbing member 32 is provided to absorb the stress causing the creep of the film component, so that the concentrated stress on the elastic film component 30 is released or uniformly processed, thereby improving the anti-creep property and avoiding the performance drift of the MEMS device.

[0066] The other components and operations of the micromechanical film structure 100 according to the embodiment of the present invention are known to those of ordinary skill in the art and will not be described in detail here. In the description of this specification, the description of the reference terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0067] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A micromechanical thin film structure of a MEMS device, characterized in that: include: substrate; An anchor seat, the anchor seat is arranged on the substrate; An elastic film assembly, the elastic film assembly comprising a film member and a stress absorbing member, the stress absorbing member being arranged on the film member to absorb stress causing creep of the film member, and one of the film member and the stress absorbing member being arranged on the anchor seat; The stress absorbing member has an absorbing space, and a transition fillet is provided on the circumferential wall of the absorbing space. The film member can transmit force to the stress absorbing member to cause the absorbing space of the stress absorbing member to deform and absorb the stress. The absorption space is a closed space or an open space with an opening; The open space includes one or more subspaces. When the open space includes a plurality of subspaces, the openings of any two adjacent subspaces face opposite directions.

2. The micromechanical thin film structure of the MEMS device according to claim 1, characterized in that: The stress absorbing member comprises a main body, on which the subspace is formed, wherein: When the open space includes multiple sub-spaces, the main body includes a curved portion and a connecting portion, there are multiple curved portions, each of which is formed with the sub-space, the end of any two adjacent curved portions is arranged in the opening of the other, and the ends of any two adjacent curved portions are connected by the connecting portion.

3. The micromechanical thin film structure of the MEMS device according to claim 1, characterized in that: The film element is configured as a beam body or a film.

4. The micromechanical thin film structure of the MEMS device according to claim 3, characterized in that: The beam body includes a plurality of split beams, and the stress absorber is provided between any two adjacent split beams, the stress absorber includes a main body and receiving parts provided at both ends of the main body, the absorption space is formed on the main body, and the receiving parts at both ends of the main body are respectively connected to the two adjacent split beams.

5. The micromechanical thin film structure of a MEMS device according to claim 4, characterized in that: At least one of the head and tail ends of the plurality of split beams is connected to the anchor seat.

6. The micromechanical thin film structure of a MEMS device according to claim 3, characterized in that: A plurality of stress absorbing members are arranged around the film, and the stress absorbing members include a main body and receiving portions arranged at both ends of the main body, the main body is formed with the absorption space, the receiving portion at one end of the main body is connected to the anchor seat, and the receiving portion at the other end is connected to the film.

7. A MEMS device, characterized in that: A micromechanical thin film structure comprising the MEMS device according to any one of claims 1 to 6.

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