MEMS vibration reduction structure and preparation method thereof

Abstract

The present invention relates to the field of vibration reduction equipment technology, and provides a MEMS vibration reduction structure and a preparation method thereof, wherein the MEMS vibration reduction structure comprises: a base, the base is suitable for being fixedly connected to a chip; at least two pairs of vibration arms, one end of the vibration arms is connected to the base, each pair of the vibration arms is disposed on two opposite side walls of the base and is symmetrically arranged with the center of gravity of the base; and a plurality of fixing parts, each of the fixing parts is fixed one-to-one with each of the vibration arms, and the fixing parts of the vibration arms are suitable for being fixedly connected to the substrate of a MEMS miniaturized device. The MEMS vibration reduction structure in the embodiment of the present invention meets the vibration reduction requirements of miniaturized devices, isolates strong vibrations and impacts from the carrier, and has the advantages of simple structure, easy production, good vibration reduction effect, and safe use.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace components, and in particular to a MEMS vibration reduction structure and a preparation method thereof. Background Art

[0002] The working mechanical environment of aerospace components is very harsh, with large vibration acceleration, wide frequency range, and long excitation time, which seriously affect the accuracy and performance of components. Therefore, a high-performance vibration reduction system must be designed to isolate the strong vibration and impact from the carrier, provide a good working environment for the measurement combination, and ensure its reliable and stable operation. To ensure the performance of the device, the common method now is to add a rubber vibration reduction bracket to the outside of the device, and then seal the vibration reduction bracket into a customized shell to form a vibration reduction system to isolate the strong vibration and impact from the carrier, ensuring its reliable and stable operation.

[0003] The existing vibration reduction system is large in size, complex in assembly, and high in cost, and cannot meet the needs of miniaturization. In addition, miniaturized devices are usually fixed by glue dispensing, where the chip is directly glued to the metal or ceramic base. Due to the mismatch of thermal expansion coefficients, the performance of the device varies greatly with temperature, and the temperature performance is poor. Summary of the invention

[0004] The embodiment of the present invention provides a MEMS vibration reduction structure and a preparation method thereof, which are used to solve the problems of large vibration reduction system and poor temperature performance of miniaturized devices in the prior art.

[0005] An embodiment of the present invention provides a MEMS vibration reduction structure, including:

[0006] A base, wherein the base is suitable for being fixedly connected to the chip;

[0007] At least two pairs of vibration arms, one end of each vibration arm is connected to the base, each pair of vibration arms is disposed on two opposite side walls of the base and are arranged symmetrically about the center of gravity of the base; and

[0008] A plurality of fixing parts are fixed to each of the vibration arms in a one-to-one correspondence, and the fixing parts of the vibration arms are suitable for being fixedly connected to the substrate of the MEMS miniaturized device.

[0009] According to a MEMS vibration reduction structure of one embodiment of the present invention, at least two pairs of vibration arms are provided, wherein the vibration arms are bent beams extending from one side of the base in a direction perpendicular to the side wall of the base to which they are connected and being bent at least once in the middle, and the ends of the two vibration arms located on the same side wall of the base connected to the fixed portion are oriented in opposite directions.

[0010] According to the MEMS vibration reduction structure of one embodiment of the present invention, the vibration arm is a straight rod extending from one side of the base in a direction perpendicular to the side wall of the base to which it is connected.

[0011] According to the MEMS vibration reduction structure of one embodiment of the present invention, the total length L of the vibration arm satisfies: 0.02 mm≤L≤20 mm, and the width W of the vibration arm satisfies: 0.005 mm≤W≤2 mm.

[0012] According to the MEMS vibration reduction structure of one embodiment of the present invention, the base, the vibration arm and the fixing part are integrally formed.

[0013] According to the MEMS vibration reduction structure of one embodiment of the present invention, the base, the vibration arm and the fixed part are made of one of quartz, silicon, AlN, ZnO, LiNbO3, LiTaO3, metal, ceramic, glass or organic materials.

[0014] According to a MEMS vibration reduction structure of an embodiment of the present invention, the MEMS vibration reduction structure further comprises a metal film, the metal film covers the surfaces of the base, the vibration arm and the fixed part, and the metal film is used for leading out the chip electrodes on the base.

[0015] According to the MEMS vibration reduction structure of one embodiment of the present invention, the metal film is a single-layer film formed by any one of Au, Cr, Ag, Al, Ti, Ni or W films, or a multi-layer film formed by any combination of two or more of them.

[0016] According to a MEMS vibration reduction structure of an embodiment of the present invention, the assembly area S of the base j The chip assembly area S a Satisfaction: S j ≥0.8S a .

[0017] An embodiment of the present invention further provides a method for preparing the MEMS vibration reduction structure as described in any one of the above items, comprising the following steps:

[0018] Select a material with a smooth surface as the base layer, and clean and dry it;

[0019] at least one mask layer on the base layer;

[0020] The metal film electrode pattern is obtained by photolithography, and then the pattern of the MEMS vibration reduction structure is obtained by photoresist with opposite polarity;

[0021] Wet etching the mask layer to obtain the shape of the MEMS vibration reduction structure on the mask layer;

[0022] Etching to obtain the base, vibration arm and fixed part structures;

[0023] The metal film electrode pattern is obtained by etching.

[0024] The MEMS vibration reduction structure and preparation method provided by the embodiment of the present invention can isolate the chip on the base from strong vibration and impact from the carrier after the chip is connected to the base through the base and the fixing part is connected to the substrate. There are multiple vibration arms, which are symmetrical about the center of gravity of the base, and can provide all-round vibration reduction protection for the chip on the base.

[0025] The surface of the MEMS vibration reduction structure is covered with a metal film, which can be used to lead out the chip electrodes on the base without the need for additional electrode lead-out circuits, thus meeting miniaturization requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 is a schematic structural diagram of a MEMS vibration reduction structure in one embodiment of the present invention;

[0028] Figure 2 is a structural schematic diagram of a MEMS vibration reduction structure in another embodiment of the present invention;

[0029] Figure 3 It is a structural schematic diagram of a MEMS vibration reduction structure in another embodiment of the present invention.

[0030] Reference numerals:

[0031] 1. Base; 2a-2n, vibration arm; 3. fixed part. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Combine the following Figure 1-Figure 2 A MEMS vibration reduction structure according to an embodiment of the present invention is described. Figure 1 MEMS vibration reduction structure and Figure 2The main difference between the MEMS vibration reduction structures in FIG. 1 and FIG. 2 is the number and structure of the vibration arms 2a - 2n.

[0034] The MEMS vibration reduction structure comprises a base 1, vibration arms 2a-2n and a fixing part 3. The base 1 is a plate-like structure with a flat surface, and the chip can be fixed on one side of the base 1.

[0035] One end of the vibration arm 2 a - 2 n is fixedly connected to the side wall of the base 1 , and the other end is connected to the fixing part 3 .

[0036] At least two pairs of vibration arms 2a - 2n are arranged in the circumferential direction of the base 1 , which can simultaneously play a vibration reduction role in all directions of the base 1 .

[0037] like Figure 1 As shown, in one embodiment of the present invention, the vibration arms 2a-2d are L-shaped structures. The vibration arms 2a-2d are disposed on two opposite sides of the base 1, and the vibration arms 2a-2d extend from the side wall of the base in a direction perpendicular to the side wall of the base to which they are connected, bend once in the middle and extend in a direction parallel to the side wall of the base 1 to which they are connected. The vibration arm 2a and the vibration arm 2d are a pair, and the vibration arm 2a and the vibration arm 2d are symmetrical about the center of gravity of the base 1; the vibration arm 2a and the vibration arm 2d are a pair, and the vibration arm 2b and the vibration arm 2c are symmetrical about the center of gravity of the base 1. The direction of the end of the vibration arm 2a connected to the fixed part 3 is opposite to the direction of the end of the vibration arm 2d connected to the fixed part 3. The direction of the end of the vibration arm 2b connected to the fixed part 3 is opposite to the direction of the end of the vibration arm 2c connected to the fixed part 3.

[0038] like Figure 2 As shown, in one embodiment of the present invention, the vibration arms 2k-2n are disposed on two opposite sides of the base 1, and the vibration arms 2k-2n extend from the side wall of the base in a direction perpendicular to the connected side wall of the base, make a first bend in the middle and extend in a direction parallel to the connected side wall of the base 1, and then make a second bend and extend in a direction perpendicular to the connecting portion. The vibration arm 2k and the vibration arm 2m are a pair, and the vibration arm 2k and the vibration arm 2m are symmetrical about the center of gravity of the base 1; the vibration arm 2l and the vibration arm 2n are a pair, and the vibration arm 2l and the vibration arm 2n are symmetrical about the center of gravity of the base 1. The direction of the end of the vibration arm 2k connected to the fixed part 3 is opposite to the direction of the end of the vibration arm 2n connected to the fixed part 3. The direction of the end of the vibration arm 2l connected to the fixed part 3 is opposite to the direction of the end of the vibration arm 2m connected to the fixed part 3.

[0039] like Figure 3As shown, in one embodiment of the present invention, the vibration arms 2e-2j are straight rods extending from one side of the base 1 in a direction perpendicular to the side wall of the connected base 1. 2e and 2h, 2f and 2i, and 2g and 2j are a pair, and each pair is symmetrical about the center of gravity of the base 1. Although three pairs are given as an example in this embodiment, it can be understood that according to actual needs, it can be set to any number of two pairs or more.

[0040] Although the above three embodiments respectively provide three fixed forms in which the vibration arms 2a-2d include one bend in the middle, the vibration arms 2k-2n include two bends in the middle, and the vibration arms 2e-2j do not include a bending portion, it is understandable that the vibration arms 2a-2n can also use a bent beam structure with any number of bends and any angles more than three times according to actual usage requirements.

[0041] Optionally, the base 1, the vibration arms 2a-2n and the fixing part 3 are integrally formed, which can not only reduce the production difficulty and production cost, but also make the MEMS vibration reduction structure have better stability and is not easy to be damaged during long-term use.

[0042] Optionally, the base 1, the vibration arms 2a-2n and the fixed part 3 are made of any functional material of MEMS process, such as quartz, silicon, ALN, ZnO, LiNbO3, LiTaO3, metal, ceramic, glass or organic material, and have the characteristics of micro-machining. And the functional material of MEMS process can make the MEMS vibration reduction structure have the same thermal expansion coefficient as other components after being applied to the MEMS miniaturized device.

[0043] In one embodiment of the present invention, the MEMS vibration reduction structure also includes a metal film (not shown in the figure), which covers the surface of the base 1, the vibration arms 2a-2n and the fixed part 3. The metal film is used to lead out the chip electrodes on the base 1, and no additional circuits are required, thereby meeting the miniaturization requirements.

[0044] Furthermore, the metal film is a single-layer film formed by any one of Au, Cr, Ag, Al, Ti, Ni or W films, or a multi-layer film formed by any combination of two or more of them, to ensure strong conductivity.

[0045] In one embodiment of the present invention, the total length L of the vibration arms 2a-2n satisfies: 0.02mm≤L≤20mm, and the width W of the vibration arms 2a-2n satisfies: 0.005mm≤W≤2mm. The frequency of the MEMS vibration reduction structure can be adjusted by adjusting the size of the vibration arms 2a-2n. When the vibration arms 2a-2n are designed to have the above size, the MEMS vibration reduction structure can be prevented from being damaged by resonance caused by external excitation during use, which may cause damage to the MEMS vibration reduction structure and the miniaturized device used therein.

[0046] In the embodiment of the present invention, the assembly area S of the base 1 is j The chip assembly area S a Satisfaction: S j ≥0.8S a , so that the base 1 can form a stable connection structure with the chip, ensuring its good safety in use and long service life.

[0047] The MEMS vibration reduction structure in the embodiment of the present invention meets the vibration reduction requirements of miniaturized devices and has the advantages of simple structure, easy production, good vibration reduction effect and safe use.

[0048] In one embodiment of the present invention, a method for preparing a MEMS vibration reduction structure is provided, comprising the following steps:

[0049] S1. Select a material with a flat surface as the base layer, and clean and dry it. The base layer can be a quartz wafer with a size of 1.6mm*0.8mm. During the cleaning and drying process, it is necessary to perform alcohol washing, alkali washing, and acid washing for 20 minutes each, then ultrasonically clean in deionized water for 10 minutes, rinse with deionized water for 3 minutes, spin dry, and dry.

[0050] S2. Form at least one mask layer on the base layer. Specifically, a quartz wafer to be coated is coated and deposited by a sputtering coating machine, and the deposition thickness is 380 nm.

[0051] S3, photolithography to obtain a metal film electrode pattern, and then obtain a MEMS vibration reduction structure pattern through a photoresist with opposite polarity;

[0052] S4, wet-etching the mask layer to obtain the shape of the MEMS vibration reduction structure on the mask layer. When wet-etching the mask layer, a special etching solution for the metal mask layer should be used.

[0053] S5, etching to obtain the structure of the base 1, the vibration arms 2a-2n and the fixing part 3;

[0054] S6. Etching to obtain a metal film electrode pattern.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A MEMS vibration reduction structure, characterized in that: include: A base, wherein the base is suitable for being fixedly connected to the chip; At least two pairs of vibration arms, one end of each vibration arm is connected to the base, and each pair of vibration arms is disposed on two opposite side walls of the base and arranged symmetrically about the center of gravity of the base; as well as A plurality of fixing parts, each of the fixing parts is fixed to each of the vibration arms in a one-to-one correspondence, and the fixing parts are suitable for being fixedly connected to a substrate of a MEMS miniaturized device; The MEMS vibration reduction structure further includes a metal film, which covers the surfaces of the base, the vibration arm and the fixed part, and is used for leading out the chip electrodes on the base; The total length L of the vibration arm satisfies: 0.02 mm ≤ L ≤ 20 mm, and the width W of the vibration arm satisfies: 0.005 mm ≤ W ≤ 2 mm; The mounting area of ​​the base Chip assembly area satisfy: .

2. The MEMS vibration reduction structure according to claim 1, characterized in that: The vibration arms shown are provided with at least two pairs, wherein the vibration arms are bent beams extending from one side of the base in a direction perpendicular to the side wall of the base to which they are connected and being bent at least once in the middle, and the ends of the two vibration arms located on the same side wall of the base connected to the fixed part are oriented in opposite directions.

3. The MEMS vibration reduction structure according to claim 1, characterized in that: The vibration arm is a straight rod extending from one side of the base in a direction perpendicular to the connected side wall of the base.

4. The MEMS vibration reduction structure according to claim 1, characterized in that: The base, the vibration arm and the fixing part are integrally formed.

5. The MEMS vibration reduction structure according to claim 1, characterized in that: The base, the vibration arm and the fixing part are made of one of quartz, silicon, AlN, ZnO, LiNbO3, LiTaO3, metal, ceramic, glass or organic materials.

6. The MEMS vibration reduction structure according to claim 1, characterized in that: The metal film is a single-layer film formed by any one of Au, Cr, Ag, Al, Ti, Ni or W films, or a multi-layer film formed by any combination of two or more of them.

7. A method for preparing a MEMS vibration reduction structure according to any one of claims 1 to 6, characterized in that: The following steps are involved: Select a material with a smooth surface as the base layer, and clean and dry it; at least one mask layer on the base layer; The metal film electrode pattern is obtained by photolithography, and then the pattern of the MEMS vibration reduction structure is obtained by photoresist with opposite polarity; Wet etching the mask layer to obtain the shape of the MEMS vibration reduction structure on the mask layer; Etching to obtain the base, vibration arm and fixed part structures; The metal film electrode pattern is obtained by etching.

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