CN108693619B

CN108693619B - Electromagnetic drive mechanism

Info

Publication number: CN108693619B
Application number: CN201810188767.XA
Authority: CN
Inventors: 高国峻; 许乃文; 黄诗婷; 聂奕心; 林孟廷
Original assignee: TDK Taiwan Corp
Current assignee: TDK Taiwan Corp
Priority date: 2017-03-29
Filing date: 2018-03-07
Publication date: 2022-10-21
Anticipated expiration: 2038-03-07
Also published as: CN108693621B; CN208297803U; CN108693619A; CN108693621A; CN108693620A; CN108693620B; CN207882548U; CN207882549U

Abstract

An electromagnetic driving mechanism comprises a shell, a circuit unit, an electromagnetic driving assembly and a sensing assembly. The circuit unit is connected with the shell and is provided with a plastic material and a circuit component, wherein the plastic material is coated on the outer side of the circuit component in an in-mold forming mode. The electromagnetic driving component is arranged in the shell and used for driving the optical component to move relative to the circuit unit. The sensing assembly is arranged on the circuit unit and electrically connected with the circuit assembly for sensing the displacement of the optical assembly relative to the circuit unit.

Description

Electromagnetic drive mechanism

Technical Field

The present invention relates to an electromagnetic drive mechanism, and more particularly to an electromagnetic drive mechanism that is miniaturized by in-mold molding.

Background

The demand of electronic products for volume is becoming more and more severe, and if the volume is to be reduced, the internal electronic components need to be integrated into a single component as much as possible. In addition, if an Integrated Circuit (IC) is required to be disposed on a Printed Circuit Board (PCB), the IC protrudes out of the PCB and occupies a space above the PCB, so that miniaturization is not easy and assembly of other components is easily affected.

Disclosure of Invention

It is an object of the present invention to provide an electromagnetic drive mechanism that solves at least one of the problems set forth above.

An embodiment of the present invention provides an electromagnetic driving mechanism, which includes a housing, a circuit unit, an electromagnetic driving component, and a sensing component. The circuit unit is connected with the shell and is provided with a plastic material and a circuit component, wherein the plastic material is coated on the outer side of the circuit component in an in-mold forming mode. The electromagnetic driving component is arranged in the shell and used for driving the optical component to move relative to the circuit unit. The sensing assembly is arranged on the circuit unit and electrically connected with the circuit assembly for sensing the displacement of the optical assembly relative to the circuit unit.

In one embodiment, the sensing element protrudes from the top surface of the circuit unit.

In one embodiment, the sensing element is aligned with the top surface of the circuit unit.

In one embodiment, the sensing element is lower than the top surface of the circuit unit.

In one embodiment, the circuit unit forms a groove, and the sensing element is disposed in the groove.

In an embodiment, the electromagnetic driving mechanism further includes a protective material disposed in the groove for protecting the sensing element.

In one embodiment, the protective material covers a top surface of the sensing device.

In an embodiment, the plastic material forms an opening, the circuit element is exposed at the opening, and the opening and the sensing element are located at opposite sides of the circuit element.

In one embodiment, the position of the opening corresponds to the sensing element.

In an embodiment, the electromagnetic driving mechanism further includes a filling material disposed in the opening.

In one embodiment, the circuit assembly has a plate-like structure embedded in the plastic material.

In one embodiment, the first central axis of the plate-shaped structure is offset from the second central axis of the circuit unit.

In an embodiment, the electromagnetic driving mechanism further includes a circuit board disposed above the circuit unit and shielding the sensing element.

In an embodiment, the electromagnetic driving mechanism further includes a coil disposed in the circuit board, and the coil and the groove at least partially overlap when viewed from the optical axis direction of the optical assembly.

In one embodiment, the sensing element is electrically connected to the circuit element before the plastic material is coated outside the circuit element by in-mold molding.

An embodiment of the present invention provides an electromagnetic driving mechanism, which includes a housing, a circuit unit, an electromagnetic driving component, and a sensing component. The circuit unit is connected with the shell and is provided with a plastic material and a circuit component, wherein the plastic material is coated on the outer side of the circuit component in an in-mold forming mode. The electromagnetic driving component is arranged in the shell and used for driving the optical component to move relative to the circuit unit. The sensing component is partially arranged in the recess or the through hole of the circuit unit and used for sensing the displacement of the optical component relative to the circuit unit, wherein the sensing component is partially overlapped with the circuit component when being observed from the direction vertical to the optical axis of the optical component.

In one embodiment, the surface of the sensing element facing the optical element and the surface of a circuit board of the circuit unit contacting the electromagnetic driving element are on the same plane.

In one embodiment, the circuit board contacts the circuit unit and the sensing element simultaneously.

In one embodiment, the circuit board and the circuit assembly are electrically connected by soldering or welding.

In one embodiment, the circuit device has a first segment extending in a direction not parallel to the optical axis of the optical device, and the sensing device overlaps the first segment when viewed perpendicular to the optical axis of the optical device.

In one embodiment, the circuit element has a second section extending in a direction parallel to the optical axis of the optical element, and the sensing element partially overlaps the second section when viewed in a direction perpendicular to the optical axis of the optical element.

The electromagnetic driving mechanism has the advantages that the sensing assembly is partially embedded in the circuit unit, so that the space for arranging the sensing assembly can be saved, and the miniaturization of the electromagnetic driving mechanism is realized.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a perspective view of an electromagnetic driving mechanism according to an embodiment of the present invention.

Fig. 2 shows an exploded view of the electromagnetic drive mechanism of fig. 1.

Fig. 3 showsbase:Sub>A cross-sectional view taken along linebase:Sub>A-base:Sub>A' in fig. 1.

FIG. 4 is a perspective view of the circuit unit and the sensing device of FIG. 2.

Fig. 5 shows a cross-sectional view taken along the line B-B' in fig. 4.

Fig. 6A shows a cross-sectional view of a circuit unit according to another embodiment of the invention.

Fig. 6B is an enlarged view of the region a in fig. 6A.

Fig. 7 shows a cross-sectional view of a circuit unit according to another embodiment of the invention.

Fig. 8 shows a cross-sectional view of a circuit unit according to another embodiment of the present invention.

Fig. 9 shows a cross-sectional view of a circuit unit according to another embodiment of the present invention.

Fig. 10A is a schematic diagram illustrating a relative position relationship between a circuit unit and a circuit board according to an embodiment of the invention.

FIG. 10B is a schematic diagram illustrating a relative position relationship between a circuit unit and a coil according to an embodiment of the invention.

Fig. 11 is a partial schematic view illustrating a structural configuration of an opening of a circuit unit according to an embodiment of the invention.

The reference numbers are as follows:

1-an electromagnetic driving mechanism;

10-shell;

10A-the top wall of the shell;

10B-side wall of the shell;

11-opening a hole on the shell;

20 circuit units;

20S-the top surface of the circuit unit;

201-an electric contact;

21-opening a hole in the circuit unit;

22-plastic material;

24-circuit components;

241 to a first section;

242 to a second section;

24F-a flat plate structure of the circuit assembly;

26-protective material;

28-groove cutting;

28A-side wall of the groove;

29-opening;

30-a bearing seat;

31-a through hole;

40. 84-coil;

50-frame;

50A-concave hole;

51-opening a hole on the frame;

60-magnet;

70-reed feeding;

72-lower reed;

74-suspension wire;

80-a circuit board;

82-a sensing assembly;

c1 to a first central shaft;

c2 to a second central shaft;

EM-electromagnetic drive components;

o-optical axis.

Detailed Description

The electromagnetic drive mechanism according to the embodiment of the present invention is explained below. It should be appreciated, however, that the present embodiments provide many suitable inventive concepts that can be embodied in a wide variety of specific contexts. The particular embodiments disclosed are illustrative only of the use of the invention in a particular manner and are not intended to limit the scope of the invention.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Referring to fig. 1 to fig. 3, in which fig. 1 showsbase:Sub>A perspective view of an electromagnetic driving mechanism 1 according to an embodiment of the invention, fig. 2 shows an exploded view of the electromagnetic driving mechanism 1 in fig. 1, and fig. 3 showsbase:Sub>A cross-sectional view alongbase:Sub>A linebase:Sub>A-base:Sub>A' in fig. 1. In the present embodiment, the electromagnetic driving mechanism 1 may be disposed in an electronic device having a camera function, and may have auto-focusing (AF) and Optical Image Stabilization (OIS) functions.

As can be seen from fig. 1 to 3, the electromagnetic driving mechanism mainly includes a housing 10, a circuit unit 20, a carrier 30, a coil 40, a frame 50, four magnets 60, an upper spring 70, a lower spring 72, four suspension wires 74, a circuit board 80, and two sensing elements 82.

The housing 10 has a hollow structure having a top wall 10A and four side walls 10B, and is connected to the circuit unit 20. It should be understood that the housing 10 and the circuit unit 20 are respectively formed with

openings

11, 21, the center of the opening 11 corresponds to an optical axis O of an optical component (not shown), and the opening 21 corresponds to an image sensing component (not shown) disposed outside the electromagnetic driving mechanism 1; accordingly, the optical element disposed in the electromagnetic driving mechanism 1 can focus on the image sensing element in the direction of the optical axis O, wherein the optical element may include a lens unit, or any other suitable optical element.

The circuit unit 20 includes a circuit component 24, and in the present embodiment, the circuit component 24 is electrically connected to a driving unit (not shown) disposed outside the electromagnetic driving mechanism 1 for performing functions such as Auto Focus (AF) and optical hand shock prevention (OIS).

The circuit unit 20 further includes a plastic material 22, wherein the plastic material 22 is coated outside the circuit component 24 by insert molding (insert molding).

The frame 50 has an opening 51 and four recesses 50A, wherein the recesses 50A correspond to the four sidewalls 10B of the housing 10, respectively. Four magnets 60 may be secured within the four recesses 50A. In some embodiments, four magnets 60 may be fixed at four corners of the frame 50, and the magnets 60 have a long bar shape.

The carrier 30 has a hollow structure and a through hole 31, wherein the optical module is locked in the through hole 31, and the coil 40 is wound around the outer peripheral surface of the carrier 30.

In the present embodiment, the four magnets 60, the coil 40 and the circuit board 80 constitute an electromagnetic driving assembly EM. It should be noted that in some embodiments, the positions of the magnets and the coils can be interchanged, that is, in some embodiments, one or more coils can be fixed on the frame 50, and the magnets corresponding to the coils are correspondingly disposed on the outer peripheral surface of the carrier 30.

As shown in fig. 2 and 3, the carrier 30 and the optical components therein are movably (movably) disposed in the frame 50. More specifically, the carriage 30 can be suspended from the center of the frame 50 by the upper spring 70 and the lower spring 72 made of metal. When a current is applied to the coil 40, an electromagnetic driving force (electromagnetic force) can be generated by the coil 40 and the magnet 60 to drive the carriage 30 and the optical assembly to move along the Z-axis direction relative to the frame 50.

The outer peripheral portions of the upper and

lower springs

70 and 72 are connected to the upper and lower sides of the frame 50, respectively, and the inner peripheral portions thereof are connected to the upper and lower sides of the carriage 30, respectively, so that the carriage 30 can be suspended in the frame 50.

The circuit board 80 is, for example, a printed circuit board, and four coils 84 (shown in fig. 10B) are provided therein, respectively corresponding to the positions of the four magnets 60.

The four suspension wires 74 are connected to the circuit unit 20 at one end and connected to the upper spring 70 at the other end, so as to suspend the frame 50, the carrier 30 and the optical component disposed therein, in the housing 10, wherein the suspension wires 74 may be made of metal, for example.

It should be understood that the circuit assembly 24 can transmit electrical signals to the coil 40 and the coil 84 in the circuit board 80, and the circuit assembly 24 can also transmit electrical signals to the coil 40 through the suspension wires 74 and the upper spring 70, so as to control the movement of the carriage 30 in the X, Y and Z directions.

As shown in fig. 2, sensing elements 82, such as Hall sensors (Hall effect sensors), magneto-resistive sensors (MR sensors) or magnetic flux sensors (flux sensors), are respectively mounted on different sides of the circuit unit 20 and electrically connected to the circuit element 24, so as to sense the magnet 60 on the frame 50 and obtain the position offset of the frame 50 and the carrier 30 relative to the circuit unit 20 in the X-axis direction and the Y-axis direction. For example, the sensing element 82 may be electrically connected (e.g., soldered) to the circuit element 24 after the plastic material 22 is molded onto the circuit element 24; in one embodiment, the sensing element 82 may be electrically connected (e.g., soldered) to the circuit element 24 before the plastic material 22 is molded onto the circuit element 24.

It should be noted that the circuit assembly 24 can generate and provide an electrical signal to the coil 84 in the circuit board 80, and the electromagnetic driving force generated between the coil 84 and the magnet 60 on the frame 50 can drive the frame 50 to move along the direction perpendicular to the optical axis O (parallel to the XY plane) to compensate the position deviation, thereby achieving the optical hand-shake (OIS) protection function.

Referring to fig. 4 to 5, fig. 4 is a perspective view of the circuit unit 20 in fig. 2, and fig. 5 is a cross-sectional view taken along line B-B' in fig. 4. In the present embodiment, the welding position of the sensing element 82 and the circuit element 24 is substantially aligned with the top surface 20S of the circuit unit 20, wherein the sensing element 82 protrudes from the top surface 20S of the circuit unit 20, thereby facilitating the welding operation, and the position of the sensing element 82 corresponds to an opening 29 on the bottom side of the circuit unit 20. In addition, the circuit assembly 24 has a plate-like structure 24F extending in a horizontal direction perpendicular to the optical axis O (Z-axis direction) of the optical assembly. As shown in fig. 5, the flat plate-like structure 24F is embedded in the plastic material 22 and has a first central axis C1 perpendicular to the optical axis O. In addition, the flat circuit unit 20 also has a second central axis C2 perpendicular to the optical axis O, wherein the first central axis C1 is higher than the second central axis C2, i.e. the first central axis C1 is located between the sensing element 82 and the second central axis C2.

Referring to fig. 6A and 6B, fig. 6A is a cross-sectional view of a circuit unit according to another embodiment of the invention, and fig. 6B is an enlarged view of a region a in fig. 6A. In the embodiment, the circuit unit 20 is formed with a groove 28, and the sensing element 82 is disposed in the groove 28, so that the position of the sensing element 82 is lowered, thereby not only reducing the overall thickness of the circuit unit 20, but also improving the flatness of the circuit element 24 to improve the assembly accuracy of the mechanism. In the present embodiment, the sensing element 82 is protected by the sidewall 28A, so that the sensing element 82 is not easy to collide with surrounding parts, wherein the distance between the sidewall 28A and the sensing element 82 may range from 0 to 2mm, and in addition, a protective material (e.g., resin) may be filled between the sidewall 28A and the sensing element 82 to improve the mechanical strength.

In another embodiment, the sensing element 82 may also be partially disposed in a recess or a through hole formed in the circuit unit 20, such that the sensing element 82 partially overlaps the circuit element 24 when viewed from a direction perpendicular to the optical axis O of the optical element. In other words, the sensing element 82 may be found to partially overlap the circuit element 24 as viewed in the direction of the XY plane. In the present embodiment, the sensing element 82 is partially embedded in the circuit unit 20, so that the space for disposing the sensing element 82 can be saved, and the miniaturization of the electromagnetic driving mechanism can be achieved.

Referring to fig. 7 again, in another embodiment, the surface of the sensing element 82 facing the optical element and the surface of the circuit board 80 (see fig. 2 and 10A) of the circuit unit 20 contacting the electromagnetic driving element EM may also be on the same plane. In other words, the top surface of the sensing element 82 is flush with the top surface 20S of the circuit unit 20, and the protective material 26 covers the side surface of the sensing element 82, so that the circuit board 80 located above the circuit unit 20 can directly contact the circuit unit 20 and the sensing element 82 at the same time, and thus the sensing element 82 is less prone to be damaged, the overall structural strength is improved, and the electromagnetic driving mechanism can be further miniaturized.

Referring to fig. 8, in another embodiment, the top surface of the sensing element 82 may be lower than the top surface 20S of the circuit unit 20, and the top surface and the side surfaces of the sensing element 82 are covered with the protective material 26 to prevent the sensing element 82 from being damaged by the collision of a foreign object. In addition, different materials may be doped into the protection material 26 as required to change its characteristics, such as doping an elastic material or a shielding material, so as to have a better shock-absorbing effect or an electromagnetic wave blocking effect.

Referring to fig. 9, in another embodiment, the sensing element 82 may be embedded in the plastic material 22 by in-mold molding, so as to achieve the effect of miniaturization of the electromagnetic driving mechanism, and simplify the manufacturing process, thereby reducing the time and cost required by the process.

It should be noted that in the embodiment shown in fig. 7 to 9, the circuit component 24 has a first segment 241 and a second segment 242, wherein the first segment 241 extends along a direction (e.g., XY plane) which is not parallel to the optical axis O of the optical component, and the second segment 242 extends along a direction which is parallel to the optical axis O of the optical component. The sensing element 82 partially overlaps the first segment 241 and the second segment 242, respectively, as viewed in a direction perpendicular to the optical axis O of the optical element. The above structure is different from a printed circuit board conventionally used in that: the conventional printed circuit board is disposed at the side of the electromagnetic driving mechanism, the internal circuit thereof extends along the optical axis O, and the circuit assembly 24 has a circuit extending along the direction perpendicular to the optical axis O, which helps to reduce the size of the electromagnetic driving mechanism in the horizontal direction.

Referring to fig. 10A and fig. 10B together, fig. 10A is a schematic diagram illustrating a relative position relationship between the circuit unit 20 and the circuit board 80 according to an embodiment of the invention, and fig. 10B is a schematic diagram illustrating a relative position relationship between the circuit unit 20 and the coil 84 according to an embodiment of the invention. As shown in fig. 10A, the circuit board 80 is disposed above the circuit unit 20 and shields the sensing element 82 (see fig. 10B). In the present embodiment, the circuit board 80 and the circuit assembly 24 are electrically connected by soldering or welding. As shown in fig. 10B, the circuit board 80 and the circuit assembly 24 are electrically connected by the electrical contacts 201 disposed on the inner edge of the circuit unit 20. In the present embodiment, the four electrical contacts 201 are arranged in a point-symmetric manner with the optical axis O as the center.

It should be noted that, for convenience of understanding, the circuit board 80 is not shown in fig. 10B, and only the coil 84 embedded in the circuit board 80 is shown. In some embodiments of the present invention, the sensing element 82 is disposed in the groove 28 of the circuit unit 20, or is completely embedded in the circuit unit 20, so that the space available for the coil 84 above the circuit unit 20 is increased, i.e., the size of the coil 84 can be increased to increase the electromagnetic driving force. As is clear from fig. 10B, the coil 84 at least partially overlaps the groove 28 as viewed in the optical axis O direction (Z-axis direction) of the optical component.

In addition, as shown in fig. 11, openings 29 are formed on the bottom sides of the circuit units 20 in the foregoing embodiments, and a filling material (not shown) may be disposed in the openings 29. The purpose of the opening 29 is to improve the heat dissipation efficiency, so as to facilitate the soldering or welding between the circuit unit 20 and the circuit element 24, after the mold forming, the circuit element 24 is exposed at the opening 29, and then the filling material is applied to the opening 29 to protect the circuit element 24, so that the foreign matters generated when the circuit unit 20 and the circuit element 24 are connected are less likely to move to other parts, and the stability of the mechanism is improved. The opening 29 and the sensing element 82 are respectively located at the upper and lower sides of the circuit element 24, and the position of the opening 29 corresponds to the sensing element 82.

In other embodiments of the present invention, the circuit module 24 may also be embedded in any of the above-mentioned components capable of embedding metal lines, for example, the circuit module 24 is embedded in the housing 10, the frame 50 or the carrying seat 30 shown in fig. 2, so as to achieve the effect of miniaturization of the driving mechanism.

Although embodiments of the present invention and their advantages have been disclosed, it should be understood that various changes, substitutions and alterations can be made herein by those skilled in the art without departing from the spirit and scope of the invention. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification, but it is to be understood that any process, machine, manufacture, composition of matter, means, method and steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present application. Accordingly, the scope of the present application includes the processes, machines, manufacture, compositions of matter, means, methods, and steps described in the specification. In addition, each claim constitutes a separate embodiment, and the scope of protection of the present invention also includes combinations of the various claims and embodiments.

Although the present invention has been described with reference to the preferred embodiments, it is to be understood that the invention is not limited thereto. Those skilled in the art to which the invention relates will readily appreciate that numerous changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should be determined only by the following claims. Furthermore, each claim constitutes a separate embodiment, and combinations of various claims and embodiments are within the scope of the invention.

Claims

1. An electromagnetic drive mechanism comprising:

a housing;

the circuit unit is connected with the shell and is provided with a plastic material and a circuit component, wherein the plastic material is coated on the outer side of the circuit component in an in-mold forming mode;

an electromagnetic driving component arranged in the shell and used for driving an optical component to move relative to the circuit unit; and

the sensing assembly is arranged on the circuit unit, is electrically connected with the circuit assembly and is used for sensing the displacement of the optical assembly relative to the circuit unit;

wherein the circuit component has a first section extending in a direction not parallel to the optical axis of the optical component, and the sensing component is partially overlapped with the first section when viewed from a direction perpendicular to the optical axis of the optical component;

the circuit unit forms a groove, the sensing component is arranged in the groove, the plastic material forms an opening, the circuit component is exposed at the opening, and the opening and the sensing component are positioned on the opposite sides of the circuit component.

2. The electromagnetic driving mechanism of claim 1, wherein the sensing element protrudes from a top surface of the circuit unit.

3. The electromagnetic drive mechanism of claim 1, wherein the sensing element is aligned with a top surface of the circuit unit.

4. The electromagnetic driving mechanism of claim 1, wherein the sensing element is lower than a top surface of the circuit unit.

5. The electromagnetic driving mechanism of claim 1, wherein the electromagnetic driving mechanism further comprises a protective material disposed in the recess for protecting the sensing element.

6. The electromagnetic drive mechanism of claim 5 wherein the protective material covers a top surface of the sensing element.

7. The electromagnetic drive mechanism of claim 1, wherein the opening is located in correspondence with the sensing element.

8. The electromagnetic drive mechanism of claim 1, wherein the electromagnetic drive mechanism further comprises a filler material disposed in the opening.

9. The electromagnetic drive mechanism of claim 1 wherein the circuit assembly has a planar structure embedded within the plastic material.

10. The electromagnetic drive mechanism of claim 9, wherein a first central axis of the plate-like structure is offset from a second central axis of the circuit unit.

11. The electromagnetic driving mechanism of claim 1 further comprising a circuit board disposed above the circuit unit and covering the sensing device.

12. The electromagnetic drive mechanism of claim 11 further comprising a coil disposed within the circuit board and at least partially overlapping the recess when viewed from an optical axis of the optical assembly.

13. The electromagnetic driving mechanism as claimed in claim 1, wherein the sensing element is electrically connected to the circuit element before the plastic material is coated outside the circuit element by in-mold molding.

14. An electromagnetic drive mechanism comprising:

a housing;

a sensing component for sensing the displacement of the optical component relative to the circuit unit, wherein the sensing component is partially overlapped with the circuit component when being observed from the direction vertical to the optical axis of the optical component;

15. The electromagnetic driving mechanism according to claim 14, wherein the surface of the sensing element facing the optical element is coplanar with the surface of a circuit board of the circuit unit contacting the electromagnetic driving element.

16. The electromagnetic drive mechanism of claim 15, wherein the circuit board directly contacts both the circuit unit and the sensing element.

17. The electromagnetic driving mechanism according to claim 16, wherein the circuit board is electrically connected to the circuit assembly by soldering or welding.

18. The electromagnetic driving mechanism according to claim 14, wherein the circuit element has a second segment portion extending in a direction parallel to the optical axis of the optical element, and the sensing element partially overlaps the second segment portion as viewed from a direction perpendicular to the optical axis of the optical element.