MEMS micro brake and manufacturing method thereof

Abstract

The present invention provides a MEMS microbrake and a manufacturing method thereof, comprising a fixed base block and a translatable base block constructed along a unidirectional axis X direction, the two being connected by at least one elastic connector having elastic force along the X-axis direction, and an elastic metal wire connected between the fixed base block and the translatable base block, generating a pulling force along the X-axis direction on the translatable base block. The MEMS microbrake provided by the present invention greatly reduces the manufacturing cost and has a higher impact resistance.

Description

Technical Field

[0001] The present application relates to the field of semiconductors, and in particular to a MEMS microbrake and a manufacturing method thereof. Background Art

[0002] High-resolution cameras have become standard equipment for various mobile electronic devices, led by smartphones, as well as security equipment, vehicle-mounted systems and other mobile devices. As applications continue to increase their requirements for imaging resolution and imaging performance, the technical requirements for camera modules are becoming increasingly higher.

[0003] With the improvement of resolution and image quality requirements, the bidirectional micro-braking function of the camera module with a translation brake carrier chip has become a must for camera anti-shake and achieving higher quality phase imaging.

[0004] Previously, the bidirectional translational braking micro-platform made of all-silicon-based wafers could meet the requirements in terms of core factors such as braking accuracy, stroke, and response speed. However, the problem was that the cost was too high, which greatly hindered the scope of its application, and its impact resistance also needed to be further improved. Summary of the invention

[0005] In order to solve the above-mentioned product performance problem, the present invention provides a MEMS micro brake and a manufacturing method thereof.

[0006] The present invention provides a MEMS micro brake, comprising a fixed base block and a translatable base block constructed along a unidirectional axis X direction, the two being connected by at least one elastic connector having elastic force along the X-axis direction, and an elastic metal wire connected between the fixed base block and the translatable base block, generating a pulling force along the X-axis direction on the translatable base block. The MEMS micro brake provided by the present invention greatly reduces the manufacturing cost and has a higher impact resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0008] Figure 1 A three-dimensional diagram of an embodiment of a MEMS microbrake of the present invention;

[0009] Figure 2 for Figure 1 The schematic cross-sectional view of the MEMS microbrake along the AB direction is shown;

[0010] Figure 3A top view of another embodiment of the MEMS microbrake of the present invention;

[0011] Figure 4a to Figure 4f For the present invention Figure 1 Schematic diagram of the manufacturing method of the MEMS micro brake shown. DETAILED DESCRIPTION

[0012] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0013] In the present invention, unless otherwise specified, the directional words used, such as "upper and lower", generally refer to the upper and lower parts of the device in normal use, and "inside and outside" refer to the outline of the device. In addition, the terms "first, second, third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first, second, third" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In the present invention, it is an electrical device, so connection and interconnection both refer to conductive interconnection. Since the accompanying drawings are descriptions of the same device, the same numbers in the drawings represent the same components.

[0014] The specific examples of the present invention are further described in detail below with reference to the accompanying drawings. Figure 1 is a three-dimensional diagram of a first embodiment of a MEMS microbrake of the present invention, Figure 2 FIG. 2 is a cross-sectional schematic diagram of an embodiment of a MEMS microbrake according to the present invention along the AB direction. Figure 1 As shown, in this embodiment, the MEMS micro brake comprises a fixed base block 100 and a translatable base block 200 constructed along the unidirectional axis X direction, and the two are connected by at least one elastic connector 300 with elastic force along the X axis direction, and an elastic metal wire 400 is connected between the surface of the fixed base block 100 and the translatable base block 200, generating a pulling force along the X axis direction for the translatable base block 200. The fixed base block 100 and the translatable base block 200 are silicon or its compound. The elastic connector 300 is metal or silicon compound.

[0015] In this embodiment, there are two elastic connectors 300 connected to the two sides of the fixed base block 100 and the translatable base block 200, and the elastic connector 300 is a folding line type, and is elastic in the folding direction, i.e., the X direction. Specifically, the elastic connector 300 is U-shaped, and the two openings of the U-shaped are respectively connected to the fixed base block 100 and the translatable base block 200, so that the translatable base block 200 can move relative to the fixed base block 100 along the X-axis direction.

[0016] The fixed base block 100 and the translatable base block 200 are provided with a plurality of circular anchor piles, and the elastic metal wire 400 is fixedly connected to the fixed base block 100 and wound around a part of the circumference of the circular anchor piles, so that the fixed base block 100 and the translatable base block 200 can move along the X-axis direction and generate a pull-back force for approaching.

[0017] The fixed base block 100 has a first circular anchor pile 110, and the corresponding translatable base block 200 has a second circular anchor pile 210 and a third circular anchor pile 220. The two ends of the elastic metal wire 400 are fixedly connected to the fixed base block 100 and are sequentially wound around the second circular anchor pile 210, the first circular anchor pile 110, and the third circular anchor pile 220, forming a broken line shape. The two ends of the elastic metal wire 400 are welded to the fixed base block 100. Figure 1 As shown, the two ends of the elastic metal wire 400 are fixedly connected to the fixed connection device 120 on the fixed base, for example, by welding. The fixed connection device, the first circular anchor pile, the second circular anchor pile, and the third circular anchor pile are silicon compounds. The material of the elastic metal wire is any one of aluminum, copper, and iron, or a combination thereof.

[0018] In this embodiment, the fixed base block 100 and the translatable base block 200 are mechanically connected by two elastic connectors 300 symmetrically arranged along the X axis. The elastic connector 300 can generate a pullback or elastic stress on the translatable base block 200 relative to the equilibrium state. The two ends of the elastic metal wire 400 are welded to the fixed connection device 120, i.e., the electrode pad, on the surface of the fixed base block, and are wrapped around the circular anchor piles on the fixed base block 100 and the translatable base block 200, which not only increases the total length of the retractable memory metal wire, but also increases the scale range of the translatable base block relative to the fixed base block.

[0019] refer to Figure 2 The structure diagram of the top cover included in the microbrake is shown, which optionally includes a fixed cover plate 510 bonded to the fixed base block 100 and a movable cover plate 520 bonded to the translatable base block, both of which are also connected by an elastic connector, and the basic configuration is similar to the combination of the fixed base block and the translatable base block, and the process manufacturing process is also similar, which can be completed on two different silicon wafers and then bonded by wafer-level bonding.

[0020] Figure 3 This is a schematic diagram of another embodiment. In this embodiment, a section of metal wire 230 is welded on the fixed base block 100, and the other end of the metal wire 230 is connected to the elastic metal conductor 400. The translatable base block 200 is provided with a plurality of circular anchor piles, and the elastic metal conductors are sequentially wound around a part of the circumference of each circular anchor pile in a zigzag shape.

[0021] The following is a further explanation of the manufacturing method of the MEMS microbrake. Figures 4a to 4f The manufacturing method of the MEMS micro actuator is shown.

[0022] The manufacturing method of the MEMS microbrake of this embodiment comprises the following steps:

[0023] First, refer to Figure 4a , providing a first substrate 10; in this embodiment, the first substrate 10 can be a silicon wafer substrate or a substrate of other materials.

[0024] Next, refer to Figure 4b , etching the first substrate 10 to form a first groove 20 , wherein the first groove 20 separates the first substrate 10 into a portion corresponding to the fixed base block 100 and a portion corresponding to the translatable base block 200 .

[0025] Next, refer to Figure 4c , a first sacrificial layer 30 is formed in the first groove 20, and the first sacrificial layer 30 corresponds to the elastic connecting member; specifically, the material of the first sacrificial layer can be a photoresist material.

[0026] Next, refer to Figure 4d Circular anchor piles are formed on the surface of the first substrate 10 corresponding to the fixed base block 100 and the translatable base block 200, and metal pads are formed on the edge area of ​​the corresponding fixed base block.

[0027] Next, refer to Figure 4e , forming a second sacrificial layer 40; specifically, the material of the second sacrificial layer may be a photoresist material.

[0028] Next, refer to Figure 4f , forming an elastic metal wire 400 on the second sacrificial layer 40; and then removing a portion of the thickness of the first substrate 10 from the back side, so that the bottom of the first sacrificial layer 30 in the first groove is exposed.

[0029] Next, refer to Figure 2 , removing the first sacrificial layer and the second sacrificial layer, so that the elastic metal wire is suspended on the first substrate. The first sacrificial layer and the second sacrificial layer can be removed by wet chemical etching or ashing.

[0030] Optionally, the following steps are also included:

[0031] A cover 500 is bonded on the first substrate 10, and the cover includes a fixed cover plate 510 and a movable cover plate 520. The elastic connector and the elastic metal wire are placed in a cavity surrounded by the cover and the first substrate.

[0032] The preferred sacrificial layer material is silicon dioxide, which is usually deposited by CVD or LPCVD. In order to maintain the mechanical stability of the device during processing, the sacrificial layer can be removed by chemical gas reaction after completing other process flows, or even after completing the capping bond.

[0033] exist Figure 2 In the illustrated embodiment, the metal wire 230 placed on the fixed base block is a metal wire without electrical drive or expansion and contraction capabilities and can be fixed on the surface of the fixed base block, while the elastic metal wire 400 is suspended on the surface of the translatable base block, so that when driven by a forward or reverse current, the elastic metal wire will undergo an extension or contraction deformation, making full use of the maximum expansion and contraction limit, thereby lengthening the length of the suspended section of the elastic metal wire to increase the expansion and contraction deformation limit.

[0034] The above method of the present invention is formed by semiconductor technology, in other words, it is formed in a semiconductor chip, so it has the characteristics of small size, low cost, high precision of the semiconductor chip, and good compatibility with semiconductor technology.

[0035] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structural or equivalent process transformations made using the contents of the specification and drawings of the present application, such as the mutual combination of technical features between the embodiments, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A MEMS microbrake, characterized in that: It comprises a fixed base block and a translatable base block constructed along the unidirectional axis X direction, and the two are connected by at least one elastic connecting member with elastic force along the X-axis direction; The elastic metal wire is connected between the fixed base block and the translatable base block, and generates a pulling force along the X-axis direction on the translatable base block; The elastic metal wire is suspended on the surface of the translatable base block, and when driven by a forward or reverse current, the elastic metal wire will undergo an extension or contraction deformation.

2. The MEMS microbrake according to claim 1, characterized in that: The fixed base block and the translatable base block are made of silicon or a compound thereof.

3. The MEMS microbrake according to claim 2, characterized in that: The elastic connecting piece is made of metal or silicon compound.

4. The MEMS microbrake according to claim 3, characterized in that: It comprises two elastic connecting members connected at two ends of two adjacent side edges of a fixed base block and a translatable base block, wherein the elastic connecting members are in a folding line shape and are elastic in the folding direction.

5. The MEMS microbrake according to claim 3, characterized in that: It includes two elastic connecting members connected at the two ends of two sides close to the fixed base block and the translatable base block. The elastic connecting member is U-shaped, and the two openings of the U-shaped are respectively connected to the fixed base block and the translatable base block, so that the translatable base block can move relative to the fixed base block along the X-axis direction.

6. The MEMS microbrake according to claim 3, characterized in that: The fixed base block and the translatable base block are provided with a plurality of circular anchor piles, and the elastic metal wire is fixedly connected to the fixed base block and wound around a part of the circumference of the circular anchor piles, so that the fixed base block and the translatable base block can move along the X-axis direction and generate a pull-back force for approaching.

7. The MEMS microbrake according to claim 1, characterized in that: The fixed base block has a first circular anchor pile, and the corresponding translatable base block has a second circular anchor pile and a third circular anchor pile. Both ends of the elastic metal wire are fixedly connected to the fixed base block and are sequentially wound around the partial circumference of the second circular anchor pile, the first circular anchor pile, and the third circular anchor pile in a zigzag shape.

8. The MEMS microbrake according to claim 7, characterized in that: Two ends of the elastic metal wire are welded on the fixed base block.

9. The MEMS microbrake according to claim 7, characterized in that: The first circular anchor pile, the second circular anchor pile and the third circular anchor pile are made of silicon compounds.

10. The MEMS micro-brake according to claim 1, characterized in that: The material of the elastic metal wire is any one of aluminum, copper, and iron, or a combination thereof.

11. The MEMS micro-brake according to claim 6, characterized in that: A section of metal wire is welded on the fixed base block, and the other end of the metal wire is connected to an elastic metal wire. The translatable base block is provided with a plurality of circular anchor piles, and the elastic metal wires are sequentially wound around a part of the circumference of each circular anchor pile in a zigzag shape.

12. The MEMS micro-brake according to claim 1, characterized in that: It also includes a cover, which is bonded to the fixed base block and the translatable base block, and forms a cavity with the fixed base block and the translatable base block. The elastic metal wire is located in the cavity.

13. The MEMS micro-brake according to claim 12, characterized in that: The cover comprises a fixed cover plate bonded to a fixed base block and a movable cover plate bonded to a translationally movable base block, and the two are connected via an elastic connecting piece.

14. A method for manufacturing a MEMS microbrake according to any one of claims 1 to 13, characterized in that: Includes steps: providing a first substrate; Etching the first substrate to form a first groove, wherein the first groove separates the first substrate into a portion corresponding to the fixed base block and a portion corresponding to the translatable base block; forming a first sacrificial layer in the first groove, the first sacrificial layer corresponding to the elastic connecting member; Forming circular anchor piles on the surfaces of the first substrate corresponding to the fixed base block and the translatable base block, and metal pads corresponding to the edge areas of the fixed base block; forming a second sacrificial layer; forming an elastic metal wire on the second sacrificial layer; Removing a portion of the thickness of the first substrate from the back side so that the bottom of the first sacrificial layer in the first groove is exposed; The first sacrificial layer and the second sacrificial layer are removed, so that the elastic metal wire is suspended on the first substrate.

15. The method for manufacturing a MEMS microbrake according to claim 14, characterized in that: Includes steps: A cover is bonded on the first substrate, and the elastic connector and the elastic metal wire are placed in a cavity surrounded by the cover and the first substrate.

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