CN117040229A - MEMS miniature voice coil motor - Google Patents

Abstract

The invention discloses a MEMS micro voice coil motor, which includes: a magnetic yoke, which has a Japanese-shaped structure, and a permanent magnet is arranged on the magnetic yoke; a micro three-dimensional MEMS coil, which has a rectangular structure, and the middle part of the micro three-dimensional MEMS coil A rectangular slot is provided, and the center beam of the magnetic yoke passes through the rectangular slot; the packaging component includes four walls arranged in a rectangular structure, and the two opposite walls are fixedly connected through a fixed component, and the magnetic yoke is arranged in the middle of the four walls. And there are elastic components and output shafts respectively arranged between the magnetic yoke and the two opposite walls on the left and right. The output shaft is arranged on the magnetic yoke, and the two ends of the output shaft respectively pass through the wall and extend out of the package components; among them, the micro three-dimensional MEMS coil The end faces are covered with conductive coating. The invention adopts a "Sun"-shaped magnetic yoke, which effectively increases the intensity of the air gap magnetic field; it simplifies the power supply method and designs a mortise and tenon structure to reduce the difficulty of assembly in tiny sizes.

Description

A MEMS micro voice coil motor

Technical field

The present invention relates to the field of microelectromechanical systems (MEMS), and in particular to a MEMS micro voice coil motor.

Background technique

The voice coil motor is a linear motor with a simple structure. Its driving principle is that the energized wire is acted upon by electromagnetic force in the magnetic field to produce movement. Voice coil motors have the advantages of small size, fast response and simple control. They have been widely used in camera lens focus adjustment, micro platform positioning and other fields. In addition, micro voice coil motors are used as driving devices in micro pumps, micro robots and micro aircraft. It also has great application potential.

Current micro voice coil motors mostly use mechanically wound coils. For example, the Chinese invention patent application with application number 202011069860.2 discloses an ultra-small volume voice coil motor with a maximum size of 3mm, which solves the problem of radial magnetization of permanent magnets. problem, but there are still some shortcomings: because the coil is wound with 0.04mm enameled wire, and adhesive is used to assemble the coil and the yoke, this will affect the repeatability of the motor, and more than 200 turns of enameled wire are passed in The heating problem when using electric current is very serious and will cause the performance of the motor to decrease.

In addition, a Chinese utility model patent with application number 202020069335. However, this solution also has problems similar to the voice coil motor proposed above.

Based on the above reasons, the present invention provides a MEMS micro voice coil motor.

Contents of the invention

The purpose of the present invention is to provide a MEMS micro voice coil motor to solve the problems existing in the existing technology.

To achieve the above objectives, the present invention provides the following solutions: The present invention provides a MEMS micro voice coil motor, including:

A magnetic yoke, the magnetic yoke has a Japanese-shaped structure, and a permanent magnet is provided on the magnetic yoke;

Micro three-dimensional MEMS coil, the micro three-dimensional MEMS coil has a rectangular structure, a rectangular slot is provided in the middle of the micro three-dimensional MEMS coil, and the center beam of the magnetic yoke passes through the rectangular slot;

Packaging component, the packaging component includes four walls arranged in a rectangular structure, two opposite walls are fixedly connected through a fixing component, the yoke is arranged in the middle of the four walls, and the yoke is connected to the left and right sides Elastic components are respectively arranged between the two oppositely arranged wall surfaces;

An output shaft is provided on the yoke, and both ends of the output shaft pass through the wall and extend out of the packaging component;

Wherein, the end surface of the micro three-dimensional MEMS coil is covered with a conductive coating.

According to the MEMS micro voice coil motor provided by the present invention, the permanent magnets include magnets that are magnetically attracted to the upper and lower beams of the yoke respectively. The magnetic poles of the two magnets are arranged oppositely. The two magnets are in contact with the micro three-dimensional MEMS coil. Corresponding settings.

According to the MEMS micro voice coil motor provided by the present invention, the wall surface includes an inner wall surface and an outer wall surface. The outer wall surface is fixed on the outside of the inner wall surface, and the inner wall surface is connected by the fixed wall surface. The components are fixedly connected, and the elastic component is provided between the yoke and the inner wall; the inner wall is made of ultraviolet light-cured resin material, and the outer wall is made of copper.

According to the MEMS micro voice coil motor provided by the present invention, the fixing component includes a plurality of positioning rods. The oppositely arranged inner wall surfaces are fixedly connected through the positioning rods. The positioning rods on adjacent inner wall surfaces are The rod space is set vertically.

According to the MEMS micro voice coil motor provided by the present invention, the elastic component includes a spring, and the springs are provided in four groups. The four groups of springs are symmetrically arranged in pairs between the inner wall surface and the yoke. The effective compression distance of the spring is greater than the stroke of the magnetic yoke.

According to the MEMS micro voice coil motor provided by the present invention, a through hole is provided at the center of the inner wall surface, and the micro three-dimensional MEMS coil contacts the outer wall surface through the through hole.

According to the MEMS micro voice coil motor provided by the present invention, the conductive coating is silver paste or copper with a thickness of 1 μm.

According to the MEMS micro voice coil motor provided by the present invention, the length of the inner wall surface is greater than the sum of the length of the yoke and the displacement distance of the yoke.

According to the MEMS micro voice coil motor provided by the present invention, the material of the magnetic yoke is DW470 silicon steel sheet.

The invention discloses the following technical effects:

When encapsulating the MEMS micro voice coil motor of the present invention, the side of the micro three-dimensional MEMS coil is covered with a conductive coating, the yoke and the coil are arranged between two opposite walls on the left and right, and an elastic component is arranged between the coil and the wall. Set up the front and rear walls, and fix the four walls through fixing components to complete the packaging of the motor.

The invention adopts a "Sun" shaped yoke, which effectively improves the strength of the air gap magnetic field; it simplifies the power supply method and designs a mortise and tenon structure to reduce the assembly difficulty in tiny sizes. The packaged motor is 4.7mm long, 2.7mm wide and 2.7mm high. 5.0mm, it can realize external output thrust and displacement on both sides.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the drawings of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a cross-sectional view of the front view of the MEMS micro voice coil motor of the present invention;

Figure 2 is an isometric view of the MEMS micro voice coil motor of the present invention;

Figure 3 is a schematic structural diagram of the packaging component of the present invention;

Figure 4 is an isometric view of Embodiment 2 of the present invention;

Figure 5 is a schematic diagram of the cooperation relationship between the magnetic yoke and the miniature three-dimensional MEMS coil in Embodiment 2 of the present invention.

Among them, 1. Magnetic yoke; 2. Micro three-dimensional MEMS coil; 3. Output shaft; 4. Inner wall; 5. Outer wall; 6. Positioning rod; 7. Spring; 8. Magnet.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Example 1:

Referring to Figures 1-3, the present invention provides a MEMS micro voice coil motor, including:

Magnetic yoke 1 has a Japanese-shaped structure and is provided with a permanent magnet;

Micro three-dimensional MEMS coil 2, micro three-dimensional MEMS coil 2 has a rectangular structure, there is a rectangular slot in the middle of the micro three-dimensional MEMS coil 2, and the center beam of the magnetic yoke 1 passes through the rectangular slot;

The packaging component includes four walls arranged in a rectangular structure. The two opposite walls are fixedly connected by fixed components. The yoke 1 is arranged in the middle of the four walls, and the yoke 1 is connected to the two opposite walls on the left and right respectively. Set up elastic components;

Output shaft 3, the output shaft 3 is arranged on the yoke 1, and both ends of the output shaft 3 pass through the wall and extend out of the package components;

Among them, the end surface of the micro three-dimensional MEMS coil 2 is covered with a conductive coating.

When encapsulating the MEMS micro voice coil motor of the present invention, the side of the micro three-dimensional MEMS coil 2 is covered with a conductive coating, the yoke 1 and the coil are arranged between two opposite walls on the left and right, and an elastic component is arranged between the coil and the wall. , then set the front and rear walls, and fix the four walls through fixing components to complete the packaging of the motor.

The "Sun"-shaped magnetic yoke 1 is different from the "E"-shaped magnetic yoke 1 used in the past. It has four closed magnetic circuits. This structure can achieve better beam magnetic effect. The magnetic field lines generated by one pole of the permanent magnet pass through the yoke 1, generate a magnetic flux perpendicular to the coil surface at the air gap, and return to the other pole of the permanent magnet along the yoke 1 to form a closed magnetic circuit. When the motor is working, the coil is energized and receives ampere force in the magnetic field to move.

In a further optimized solution, the permanent magnets include magnets 8 that are magnetically attracted to the upper and lower beams of the yoke 1 respectively. The magnetic poles of the two magnets 8 are arranged oppositely, and the two magnets 8 are arranged corresponding to the miniature three-dimensional MEMS coil 2. This motor has a compact structure and does not require additional guide rails. The permanent magnet is embedded in the yoke 1 through magnetic force. There is a yoke slot in the middle of the rectangular three-dimensional MEMS coil. When the motor is working, the middle beam of the yoke 1 is inserted into the slot to realize the connection between the coil and the yoke. 1 relative motion.

To further optimize the solution, the wall includes an inner wall 4 and an outer wall 5. The outer wall 5 is fixed on the outside of the inner wall 4. The opposite inner walls 4 are fixedly connected through fixed components. The yoke 1 and the inner wall 4 Elastic components are arranged between them; the inner wall 4 is made of ultraviolet light-cured resin material, and the outer wall 5 is made of copper.

The front and rear walls of the inner layer are slotted in the center. The size of the slot is just right so that the side of the inductor coil can extend from it and stably contact the outer copper conductive wall, thereby achieving the fixation of the coil conduction and its position. The inner wall 4 also needs to be slotted on the upper and lower sides according to the size of the motor yoke 1. For example, three cylindrical holes are designed at symmetrical positions on the upper and lower sides, and cylindrical pins of corresponding sizes are processed. Multiple motors can be fixed upper and lower during assembly. between pins. The length of the front and rear walls of the inner layer is greater than the sum of the length of the yoke 1 and the designed displacement distance to ensure that the yoke 1 can perform a complete stroke. At the same time, a micro-spring 7 with one end drawn out is selected to position the yoke 1 to ensure that it is at the center position in the initial state. The effective compression distance of the spring 7 is required to be greater than the motor stroke, and the elastic force is moderate to ensure the static position of the yoke 1. , and at the same time, the maximum elastic force is less than the motor output thrust to ensure the normal operation of the motor. Microholes are designed at corresponding positions on the left and right walls so that the leads of the springs 7 can pass through them to stably install the springs 7 . In addition, a cylindrical structure is installed in the middle of the left and right surfaces of both ends of yoke 1 for the output of thrust and displacement. It is required that the width of the cylinder does not exceed the width of yoke 1, and the length is greater than the designed effective stroke. This can be done when processing yoke 1 Mark the position of the column in advance to facilitate installation. At the same time, open holes at the corresponding positions on the left and right walls to allow the column to extend. Make sure that the length of the column extending out of the wall is greater than the designed motor stroke. The upper and lower surfaces are fixed in contact with other wall surfaces using adhesive to complete the motor packaging.

In a further optimized solution, the fixing assembly includes a plurality of positioning rods 6. Oppositely arranged inner walls 4 are fixedly connected by positioning rods 6, and the positioning rods 6 on adjacent inner walls 4 are arranged vertically in space.

In a further optimized solution, the elastic component includes four groups of springs 7. The four groups of springs 7 are arranged symmetrically between the inner wall 4 and the yoke 1. The effective compression distance of the spring 7 is greater than the stroke of the yoke 1.

In order to ensure that the yoke 1 is located at the center of the wall in the initial state, a miniature spring 7 whose stiffness coefficient and length matches the thrust and stroke of the motor can be installed between the yoke 1 and the walls on the left and right sides. In addition, a section of cylindrical needle rollers is installed at the center of the outer side of the yoke 1 in the left and right directions. The length of the cylindrical needle rollers is required to be greater than the motor stroke, so that thrust and displacement can be output to both sides.

In a further optimized solution, a through hole is provided at the center of the inner wall 4, and the micro three-dimensional MEMS coil 2 contacts the outer wall 5 through the through hole.

To further optimize the solution, the conductive coating is silver paste or copper with a thickness of 1 μm.

In a further optimization solution, the length of the inner wall 4 is greater than the sum of the length of the yoke 1 and the displacement distance of the yoke.

To further optimize the solution, DW470 silicon steel sheet is selected as the material of yoke 1. The material of yoke 1 is DW470 silicon steel sheet, and the permanent magnet material is N48 neodymium iron boron. When the effective stroke of the micro voice coil motor is 500 μm, the "Japanese" character yoke 1 is 2.6mm long, 1mm wide, and 2.75mm high. The upper and lower beams are The thickness of the middle beam and side beams are both 450μm, and the permanent magnet is 400μm thick and 1.7mm long. The coil is bonded by double-layer 500μm silicon wafers. The outer dimensions are: 1.2mm long, 2.2mm wide and 1mm thick. The dimensions of the internal yoke slot are: 1mm wide and 550μm high. The bare motor is thus processed.

Example 2:

Referring to Figures 4-5, this embodiment provides a packaging method for a moving coil MEMS micro voice coil motor, which includes the following steps:

Step 1: Make a package component and cover the side of the micro three-dimensional MEMS coil 2 with conductive material, so that the coil can be powered by energizing the inner wall 4;

Step 2: Slot the front and rear center of the inner wall 4 in a horizontal direction, and the slot width ensures that the micro three-dimensional MEMS coil 2 extends and slides inside;

Step 3: Groove the inner side of the outer wall 5, fix the outer wall 5 on the inner wall 4, the distance between the side of the micro three-dimensional MEMS coil 2 and the outer wall 5 is greater than or equal to 1 μm, and fill the gap with graphite powder to achieve conductive lubrication,

Step 4: Horizontal mounting holes are symmetrically opened on the micro three-dimensional MEMS coil 2, the output shaft 3 is installed in the mounting holes, and the front and rear walls are installed on the packaging component to complete the motor packaging.

In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientations or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or It is implied that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation and is therefore not to be construed as a limitation of the invention.

The above-described embodiments only describe the preferred modes of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, those of ordinary skill in the art can make various modifications to the technical solutions of the present invention. All deformations and improvements shall fall within the protection scope determined by the claims of the present invention.

Claims (9)

1. A MEMS micro voice coil motor, comprising:

the magnetic yoke (1), wherein the magnetic yoke (1) is of a Chinese character 'ri' shaped structure, and a permanent magnet is arranged on the magnetic yoke (1);

the miniature three-dimensional MEMS coil (2), the miniature three-dimensional MEMS coil (2) is of a rectangular structure, a rectangular groove is formed in the middle of the miniature three-dimensional MEMS coil (2), and a center beam of the magnetic yoke (1) penetrates through the rectangular groove;

the packaging assembly comprises four wall surfaces which are arranged in a rectangular structure, two opposite wall surfaces are fixedly connected through a fixing assembly, the magnetic yoke (1) is arranged in the middle of the four wall surfaces, and elastic assemblies are respectively arranged between the magnetic yoke (1) and the wall surfaces which are arranged in a left-right opposite mode;

the output shaft (3) is arranged on the magnetic yoke (1), and two ends of the output shaft (3) respectively penetrate through the wall surface and extend out of the packaging assembly;

the end face of the miniature three-dimensional MEMS coil (2) is covered with a conductive coating.

2. The MEMS micro-voice coil motor of claim 1, wherein: the permanent magnet comprises magnets (8) which are respectively magnetically attracted on the upper beam and the lower beam of the magnet yoke (1), the magnetic poles of the two magnets (8) are oppositely arranged, and the two magnets (8) are correspondingly arranged with the miniature three-dimensional MEMS coil (2).

3. The MEMS micro-voice coil motor of claim 1, wherein: the wall surface comprises an inner wall surface (4) and an outer wall surface (5), the outer wall surface (5) is fixed on the outer side of the inner wall surface (4), the inner wall surface (4) is fixedly connected through the fixing component, and the elastic component is arranged between the magnetic yoke (1) and the inner wall surface (4); the inner layer wall surface (4) is made of ultraviolet light curing resin material, and the outer layer wall surface (5) is made of copper.

4. A MEMS micro-voice coil motor as claimed in claim 3, wherein: the fixing assembly comprises a plurality of positioning rods (6), wherein the inner layer wall surfaces (4) which are oppositely arranged are fixedly connected through the positioning rods (6), and the positioning rods (6) on the adjacent inner layer wall surfaces (4) are vertically arranged in space.

5. A MEMS micro-voice coil motor as claimed in claim 3, wherein: the elastic component includes spring (7), spring (7) are provided with four groups, four groups spring (7) pairwise symmetry set up inner wall (4) with between yoke (1), the effective compression distance of spring (7) is greater than the stroke of yoke (1).

6. A MEMS micro-voice coil motor as claimed in claim 3, wherein: a through hole is formed in the center of the inner layer wall surface (4), and the miniature three-dimensional MEMS coil (2) is in contact with the outer layer wall surface (5) through the through hole.

7. The MEMS micro-voice coil motor of claim 1, wherein: the conductive coating is silver paste or copper with the thickness of 1 mu m.

8. A MEMS micro-voice coil motor as claimed in claim 3, wherein: the length of the inner layer wall surface (4) is larger than the sum of the length of the magnetic yoke (1) and the displacement distance of the magnetic yoke (1).

9. The MEMS micro-voice coil motor of claim 1, wherein: the material of the magnetic yoke (1) is DW470 silicon steel sheet.