CN113497536B

CN113497536B - Actuator, forming method thereof, driving method thereof, electronic device and imaging module

Info

Publication number: CN113497536B
Application number: CN202010249634.6A
Authority: CN
Inventors: 黄河
Original assignee: Ningbo Semiconductor International Corp
Current assignee: Ningbo Semiconductor International Corp
Priority date: 2020-04-01
Filing date: 2020-04-01
Publication date: 2022-10-18
Anticipated expiration: 2040-04-01
Also published as: CN113497536A

Abstract

An actuator, a forming method, a driving method, an electronic device and an imaging module thereof, the actuator comprising: a first conductive post; the coil structure, link to each other with first leading electrical pillar, include: the bottom conducting layers are arranged at intervals, the first bottom conducting layer and the second bottom conducting layer are respectively arranged at the most edges along the arrangement direction, the third bottom conducting layer is arranged between the first bottom conducting layer and the second bottom conducting layer, one end of the first bottom conducting layer is connected with the first conducting column, and the upper surface and the lower surface of the bottom conducting layer are planes; the second conductive column is vertically positioned on the bottom conductive layer and is respectively connected with two ends of the third bottom conductive layer, one end of the first bottom conductive layer, which is far away from the first conductive column, and at least one end of the second bottom conductive layer; the two ends of each top conductive layer are connected with the different ends of the adjacent bottom conductive layers in sequence through the second conductive columns, and at least the lower surface of each top conductive layer is a plane. The invention reduces the manufacturing difficulty, the structure complexity and the use complexity of the actuator and improves the performance.

Description

Actuator, forming method thereof, driving method thereof, electronic device and imaging module

Technical Field

The embodiment of the invention relates to the field of semiconductor manufacturing, in particular to an actuator, a forming method, a driving method, electronic equipment and an imaging module of the actuator.

Background

With the rapid development of electronic terminals such as digital cameras or smart phones, the shooting function has become an indispensable part of the electronic terminals, and with the improvement of the quality of life of people, the requirements of people on the shooting effect are higher and higher. In some electronic terminals, it is often necessary to translate or stretch some of the components in order to perform some special functions, such as: optical Image Stabilization (OIS) is achieved.

The optical anti-shake is realized by using a special lens or a special photosensitive element to reduce the image instability caused by shaking or object movement during the use process of an operator to the maximum extent. At present, an optical anti-shake technique is to detect a small movement by a gyroscope in a lens, transmit a signal to a microprocessor to immediately calculate a displacement amount to be compensated, and then compensate the movement amount according to a shake direction through a compensation lens set, thereby effectively overcoming image blur caused by vibration of a camera. In some electronic terminals such as cameras and mobile phones having a lens module, a movable lens is displaced in an optical axis direction to focus or zoom by a driving mechanism such as a VCM Motor, or displaced in a direction perpendicular to the optical axis direction to prevent optical shake.

Disclosure of Invention

Embodiments of the present invention provide an actuator, a method for forming the same, a method for driving the actuator, an electronic device, and an imaging module, which improve performance of the actuator while reducing manufacturing difficulty, structural complexity, and use complexity of the actuator.

To solve the above problems, an embodiment of the present invention provides an actuator for moving or stretching a device to be driven, including: a first conductive pillar; a coil structure, with the first conductive pillar links to each other, the coil structure includes: the bottom conducting layers at the extreme edges are respectively a first bottom conducting layer and a second bottom conducting layer along the arrangement direction of the bottom conducting layers, the rest bottom conducting layers between the first bottom conducting layer and the second bottom conducting layer are third bottom conducting layers, one end of the first bottom conducting layer is connected with the first conducting column, and the upper surface and the lower surface of the bottom conducting layer are planes; the second conductive columns are vertically positioned on the bottom conducting layer, and are in one-to-one correspondence with and connected with two ends of the third bottom conducting layer, one end of the first bottom conducting layer, which is far away from the first conductive columns, and at least one end of the second bottom conducting layer; the top conducting layers are arranged at intervals and suspended on the bottom conducting layers, two ends of each top conducting layer sequentially connect different ends of the adjacent bottom conducting layers through the second conducting columns, and at least the lower surfaces of the top conducting layers are planes; and the second bottom conducting layer is used for being connected with the device to be driven.

Correspondingly, the embodiment of the invention also provides a forming method of the actuator, which comprises the following steps: providing a substrate; forming a first sacrificial layer covering the substrate; forming a first conductive pillar through the first sacrificial layer; forming a plurality of bottom conductive layers arranged at intervals on the first sacrificial layer, wherein the bottom conductive layers at the outermost edges are a first bottom conductive layer and a second bottom conductive layer respectively along the arrangement direction of the bottom conductive layers, the rest bottom conductive layers between the first bottom conductive layer and the second bottom conductive layer are third bottom conductive layers, and one end of the first bottom conductive layer is connected with the first conductive column; forming a second sacrificial layer covering the first sacrificial layer and the bottom conductive layer, and a plurality of second conductive pillars penetrating through the second sacrificial layer, wherein the second conductive pillars are in one-to-one correspondence with and connected to two ends of the third bottom conductive layer, one end of the first bottom conductive layer, which is far away from the first conductive pillars, and at least one end of the second bottom conductive layer; forming a plurality of top conductive layers arranged at intervals on the second sacrificial layer, wherein two ends of each top conductive layer sequentially connect different ends of the adjacent bottom conductive layers through the second conductive posts, and the bottom conductive layers, the second conductive posts and the top conductive layers are used for forming a coil structure; and after the top conductive layer is formed, removing the second sacrificial layer and the first sacrificial layer.

Correspondingly, an embodiment of the present invention further provides a driving method of the actuator, including: performing displacement processing, and loading a driving current to the coil structure to form an electromagnetic field around the U-shaped coil structure, wherein the electromagnetic field is used for enabling the coil structure to contract along the arrangement direction of the bottom conducting layer; and executing displacement recovery processing, and stopping loading the driving current to the coil structure to eliminate the electromagnetic field around the coil structure so as to recover the coil structure.

Correspondingly, an embodiment of the present invention further provides an electronic device, including: a device to be driven; at least one actuator as described above, wherein the second bottom conductive layer is connected to the device to be driven.

Correspondingly, an embodiment of the present invention further provides an imaging module, including: an image sensor; a lens assembly corresponding to the image sensor, the lens assembly comprising: the device to be driven is a flexible lens and corresponds to the image sensor; and a plurality of the above actuators arranged around the device to be driven at equal angles along the circumferential direction, wherein in each of the actuators, the second bottom conductive layer is connected to the device to be driven.

Correspondingly, an embodiment of the present invention further provides an imaging module, including: a device to be driven, the device to be driven being an image sensor; one or more of the above-mentioned actuators, each of said actuators being connected to the same end of said device to be driven, in each of said actuators said second bottom conductive layer being connected to said device to be driven; a lens assembly corresponding to the image sensor.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following advantages:

the embodiment of the invention provides an actuator, which is used for moving or stretching a to-be-driven device, and comprises a coil structure connected with a first conductive column, wherein the coil structure comprises a plurality of bottom conductive layers which are arranged at intervals, the bottom conductive layers at the extreme edges are respectively a first bottom conductive layer and a second bottom conductive layer along the arrangement direction of the bottom conductive layers, the rest bottom conductive layers between the first bottom conductive layers and the second bottom conductive layers are third bottom conductive layers, one end of the first bottom conductive layers is connected with the first conductive columns, the coil structure further comprises a plurality of top conductive layers which are arranged at intervals, the two ends of each top conductive layer are connected with the different ends of the adjacent bottom conductive layers in sequence through the second conductive columns, the second bottom conductive layers are connected with the to-be-driven device, therefore, the first bottom conductive layers are used as fixed ends in the coil structure, the second bottom conductive layers are used as movable ends in the coil structure, so that the different ends of the adjacent bottom conductive layers are connected through the second conductive columns in sequence, the second bottom conductive layers are used for being connected with the to-be-driven device, the coil structure, and the movable ends can generate a corresponding current when the coil structure moves, and the coil structure contracts, so that the coil structure can generate a displacement of the electromagnetic field, and the coil structure can be driven device can be driven by the electromagnetic field, and the coil structure, so that the coil structure can be driven device can be driven by the electromagnetic field, and the coil structure, and the displacement of the coil structure can be contracted, and the coil structure can be contracted, so that the displacement of the coil structure can be controlled; in the coil structure, the second bottom conductive layer is used for connecting with a device to be driven, and the displacement or the stretching of the device to be driven is correspondingly controlled by controlling the shrinkage of the coil structure, so that the function of the actuator is realized, therefore, the coil structure is utilized to form the actuator, the structural complexity and the use complexity of the actuator are reduced, the actuator is formed by adopting a semiconductor process, the compatibility of a Complementary Metal Oxide Semiconductor (CMOS) is higher, the manufacturing difficulty of the actuator is correspondingly reduced, in addition, the weight of the actuator formed by utilizing the semiconductor process is lighter, the reaction rate of the actuator is favorably improved, and the performance of the actuator is correspondingly improved; in summary, the actuator provided by the embodiment of the invention improves the performance of the actuator while reducing the manufacturing difficulty, the structural complexity and the use complexity of the actuator.

Drawings

FIG. 1 is a top view of one embodiment of an actuator of the present invention;

FIG. 2 is a cross-sectional view of FIG. 1 taken along line B1B 2;

FIG. 3 is a top view of another embodiment of the actuator of the present invention;

FIGS. 4-18 are schematic views of one embodiment of a method of forming an actuator of the present invention;

FIGS. 19 to 20 are schematic views of an embodiment of a driving method of the actuator of the present invention;

FIG. 21 is a diagram of an electronic device according to an embodiment of the invention.

Detailed Description

Taking the imaging module as an example, the voice coil motor is installed on the base, the lens is installed on the voice coil motor, and the voice coil motor can drive the lens to move in the frame of the imaging module to focus. The conventional voice coil motor cannot be formed by using a semiconductor process, so that the manufacturing difficulty and the structural complexity are high, and the driving method of the voice coil motor is complex. In addition, the voice coil motor has a certain weight, which causes the influence of gravity during focusing, and thus the focusing time is long, and therefore, the performance of the current voice coil motor is not good.

In order to solve the technical problem, in the embodiment of the invention, the coil structure is used for forming the actuator, and in the working process of the actuator, after the coil structure is loaded with the driving current, an electromagnetic field can be generated around the coil in the coil structure, so that the coil structure generates a displacement amount, and the displacement amount or the stretching amount of the device to be driven is correspondingly controlled, so that the function of the actuator is realized.

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

Referring to fig. 1 and 2 in combination, fig. 1 is a top view of an embodiment of the actuator of the present invention, and fig. 2 is a cross-sectional view of fig. 1 taken along line B1B 2.

In this embodiment, the actuator is used to move or stretch the device to be driven. The actuator includes: a first conductive post 130; a coil structure 200 connected to the first conductive pillar 130, the coil structure 200 comprising: the bottom conductive layers 140 are arranged at intervals, along the arrangement direction of the bottom conductive layers 140, the bottom conductive layer 140 at the outermost edge is a first bottom conductive layer 141 and a second bottom conductive layer 143, the remaining bottom conductive layer 140 between the first bottom conductive layer 141 and the second bottom conductive layer 143 is a third bottom conductive layer 142, one end of the first bottom conductive layer 141 is connected with the first conductive post 130, and the upper surface and the lower surface of the bottom conductive layer 140 are both planar; a plurality of second conductive pillars 160 vertically disposed on the bottom conductive layer 140, wherein the second conductive pillars 160 are in one-to-one correspondence with and connected to two ends of the third bottom conductive layer 142, one end of the first bottom conductive layer 141 far away from the first conductive pillars 130, and at least one end of the second bottom conductive layer 143; the top conductive layers 170 arranged at intervals are suspended on the bottom conductive layers 140, two ends of each top conductive layer 170 sequentially connect different ends of the adjacent bottom conductive layers 140 through the second conductive posts 160, and at least the lower surface of the top conductive layer 170 is a plane.

In the actuator of the embodiment, the second bottom conductive layer 143 is used to connect to a device to be driven, the coil structure 200 is a spiral tube, the first bottom conductive layer 141 is used as a fixed end in the coil structure 200, and the second bottom conductive layer 143 is used as a movable end in the coil structure 200, so that the coil structure 200 has a telescopic performance along the arrangement direction of the bottom conductive layers 140. After the driving current is applied to the coil structure 200, an electromagnetic field is generated around the coils in the coil structure 200, and under the action of the electromagnetic field, the coils attract each other, so that the movable end in the coil structure 200 moves towards the fixed end along the arrangement direction of the bottom conductive layer 140, that is, the coil structure 200 contracts, and the contraction amount of the coil structure 200 is controlled by controlling the magnitude of the driving current, so as to correspondingly control the displacement amount or the stretching amount of the device to be driven, thereby realizing the action of the actuator, therefore, the structure complexity and the use complexity of the actuator are reduced by using the coil structure 200 to form the actuator, and the actuator is formed by adopting a semiconductor process, so that the actuator has higher CMOS compatibility, which correspondingly reduces the manufacturing difficulty of the actuator, and in addition, the weight of the actuator formed by using the semiconductor process is lighter, which is beneficial to improving the reaction rate of the actuator and correspondingly improving the performance of the actuator; in summary, the present embodiment improves the performance of the actuator while reducing the manufacturing difficulty, the structural complexity, and the usage complexity of the actuator.

The actuator is manufactured by adopting semiconductor processes such as deposition, photoetching and etching, and the semiconductor processes can improve the bonding strength among all the components in the actuator, and the position accuracy and the size accuracy of all the components, so that the performance of the actuator is guaranteed; and the actuator is formed by using a semiconductor process, which is correspondingly beneficial to reducing the volume of the actuator, thereby meeting the requirement of miniaturization of electronic equipment.

As shown in fig. 2, the actuator further comprises a substrate 100. The substrate 100 is used to provide a process platform for forming the coil structure 200, and also serves as a support and fixing function for the coil structure 200 to improve the mechanical strength of the coil structure 200. In this embodiment, the substrate 100 is a semiconductor substrate to improve CMOS compatibility of the actuator formation process. Specifically, the substrate 100 is a silicon substrate. In other embodiments, the material may also be other materials such as germanium, silicon carbide, gallium arsenide, or indium gallium arsenide, and may also be other types of substrates such as a silicon-on-insulator substrate or a germanium-on-insulator substrate. In other embodiments, the substrate may be other materials that can be patterned by a semiconductor etching process, such as a silicon oxide substrate.

The substrate 100 includes at least one unit area 100S (shown in fig. 2), and each unit area 100S has a coil structure 200. In the present embodiment, only one unit area 100S is illustrated. In other embodiments, the number of the unit regions may also be multiple, that is, multiple coil structures are formed on the same substrate.

The first conductive pillar 130 is located on the substrate 100. The first conductive pillar 130 is used for fixing and supporting the coil structure 200. One end of the first bottom conductive layer 141 is connected to the first conductive pillar 130, so that the first bottom conductive layer 141 is used as a fixed end in the coil structure 200, thereby providing scalability to the coil structure 200, and the first conductive pillar 130 is used to load a driving current to the coil structure 200.

In this embodiment, the coil structure 200 is U-shaped, and the U-shaped coil structure 200 has two fixing ends, so that the number of the first conductive pillars 130 is two, and the two first conductive pillars are used for being connected to the fixing ends of the U-shaped coil structure 200 respectively; accordingly, the coil structure 200 is loaded with a driving current through the first conductive pillar 130, so that a closed loop is formed in the coil structure 200.

In this embodiment, the coil structure 200 is located above the first conductive pillar 130, the top surface of the first conductive pillar 130 is connected to the first bottom conductive layer 141, and the first conductive pillar 130 is used to raise the coil structure 200, so that the coil structure 200 achieves the telescopic function. Specifically, the coil structure 200 is suspended above the substrate 100 by the first conductive pillar 130, which is also beneficial to increase the vertical distance from the coil structure 200 to the substrate 100, and is convenient for the coil structure 200 to realize the telescopic function. In other embodiments, the first conductive pillars may extend along the arrangement direction of the bottom conductive layer, and in the arrangement direction of the bottom conductive layer, the end portions of the first conductive pillars are in contact with the sidewalls of the first bottom conductive layer.

The material of the first conductive pillar 130 includes conductive materials such as aluminum, tungsten, copper, arsenic germanide, or polysilicon. As an example, the material of the first conductive pillar 130 is copper. The resistance of copper is small, which is beneficial to improving the effect of loading the driving current to the coil structure 200, thereby improving the performance of the actuator. In the present embodiment, in a direction perpendicular to the height direction of the first conductive pillar 130, the cross section of the first conductive pillar 130 is circular or square, and the upper surface of the first conductive pillar 130 is a plane.

The actuator further comprises: an electrode layer 110 on the substrate 100; the first conductive pillar 130 is located on the electrode layer 120 and connected to the electrode layer 120. The electrode layer 110 serves as an electrode, and when the actuator is operated, the coil structure 200 is applied with a driving current through the electrode layer 110. Accordingly, when the coil structure 200 is U-shaped, the number of the electrode layers 110 is two. Specifically, the first conductive pillars 130 extend along the arrangement direction of the bottom conductive layer 140, and one side of the first conductive pillars 130 away from the coil structure 200 exposes the electrode layer 110, so as to load a driving current to the electrode layer 110. In other embodiments, the electrode layer may also be located in the substrate, and the substrate exposes a top surface of the electrode layer. In other embodiments, the actuator may not include an electrode layer. For example, when other electrodes are provided in the substrate, the first conductive pillar is directly connected to the electrodes in the substrate.

The material of the electrode layer 110 includes aluminum, tungsten, copper, arsenic germanide, or polysilicon. In this embodiment, the material of the electrode layer 110 is copper. The electrode layer 110 and the first conductive pillar 130 are made of the same material, which is beneficial to improving the bonding strength between the electrode layer 110 and the first conductive pillar 130. For a detailed description of the material of the electrode layer 110, reference may be made to the corresponding description of the first conductive pillar 130, which is not repeated herein.

In this embodiment, the coil structure 200 is U-shaped. Therefore, the bottom conductive layer 140 is U-shaped, and the projections of the first bottom conductive layer 141 and the third bottom conductive layer 142 on the sidewall of the second bottom conductive layer 143 are located in the same second bottom conductive layer 143; the second conductive pillars 160 correspond to and are connected to two ends of the second bottom conductive layer 143. In which, the coil structure 200 is U-shaped, which is beneficial to improving the mechanical strength of the coil structure 200. In the U-shaped coil structure 200, the number of the first bottom conductive layers 141 is two, the number of the second bottom conductive layers 143 is one, and the length of the second bottom conductive layers 143 is longest. Specifically, the lengths of the first and third bottom

conductive layers

141 and 142 are equal.

Accordingly, different ends of the two first bottom conductive layers 141 are in one-to-one correspondence with and connected to the first conductive pillars 130. Specifically, in the extending direction of the bottom conductive layer 140, the bottom conductive layer 140 includes a first end 140a and a second end 140b opposite to the first end 140a, the first end 140a of one first bottom conductive layer 141 is connected to one first conductive pillar 130, and the second end 140b of another first bottom conductive layer 141 is connected to another first conductive pillar 130.

In this embodiment, a certain interval is provided between the adjacent bottom conductive layers 140, so that the coil structure 200 has a telescopic function. Specifically, the plurality of bottom conductive layers 140 are arranged in parallel, thereby improving the stretching stability of the coil structure 200; the plurality of top conductive layers 170 are also correspondingly arranged in parallel. For example, the plurality of bottom conductive layers 140 extend along a first direction (shown as Y direction in fig. 1) and are arranged at intervals along a second direction (shown as X direction in fig. 1), and the first direction and the second direction are perpendicular.

In this embodiment, the bottom conductive layer 140 is formed by a semiconductor process, and thus, the upper surface and the lower surface of the bottom conductive layer are both planar. And the upper surface and the lower surface of the bottom conductive layer are both planar, which is beneficial to improving the bonding strength of the first bottom conductive layer 141 and the first conductive pillar 130, and the bonding strength of the bottom conductive layer 140 and the second conductive pillar 160. The bottom surface of the bottom conductive layer is a surface facing the first conductive pillar 130, and the top surface is a surface facing away from the first conductive pillar 130.

The second conductive pillar 160 is used to connect the bottom conductive layer 140 and the top conductive layer 170. In this embodiment, the second conductive pillars 160 are vertically located on the bottom conductive layer 140, which is beneficial to improving the bonding strength between the second conductive pillars 160 and the bottom conductive layer 140 and the mechanical strength of the second conductive pillars 160 themselves.

In this embodiment, at least the lower surface of the top conductive layer 170 is a plane, so as to improve the bonding strength between the top conductive layer 170 and the second conductive pillar 160. The lower surface of the top conductive layer 170 faces the bottom conductive layer 140. In other embodiments, the top surface of the top conductive layer may also be a plane, wherein the top surface of the top conductive layer is a surface facing away from the bottom conductive layer.

The material of any of the bottom conductive layer 140, the second conductive pillar 160, and the top conductive layer 170 includes aluminum, tungsten, copper, arsenic germanide, or polysilicon. As an example, the bottom conductive layer 140, the second conductive pillar 160, and the top conductive layer 170 are made of copper, which is beneficial to improve the bonding strength between the components. For a detailed description of the materials of the bottom conductive layer 140, the second conductive pillar 160, and the top conductive layer 170, reference may be made to the corresponding description of the first conductive pillar 130, which is not repeated herein.

In this embodiment, the second conductive pillar 160 includes one or more stacked sub-conductive pillars (not labeled) along the height direction of the second conductive pillar 160. Each metal layer or via (via) structure has a maximum height value acceptable for the process, and the height of the coil structure 200 can be adjusted by setting the number of the sub-conductive pillars. For example, the second conductive pillar 160 includes a plurality of sub-conductive pillars, which are metal layers or via structures.

In this embodiment, the substrate 100 has an opening 105 penetrating the substrate 100, and the opening 105 exposes the coil structure 200. By providing an opening 105 in the substrate 100, the actuator can be used in an imaging module. Specifically, the second bottom conductive layer 143 is used for connecting with a device to be driven, and the imaging module generally includes an image sensor and a lens assembly located above the image sensor, and the lens assembly includes a lens, and when the image sensor or the flexible lens is used as the device to be driven, through the opening 105, the optical signal can penetrate through the flexible lens and be received by the image sensor, so that the normal use performance of the imaging module is ensured. In other embodiments, the substrate may not have openings therein, depending on the context in which the actuator is used. In other embodiments, the actuator may be provided without a substrate to reduce the thickness of the actuator.

Correspondingly, the invention also provides another actuator. Figure 3 is a top view of another embodiment of the actuator of the present invention. The same parts of the embodiments of the present invention as those of the previous embodiments are not described herein again, and the differences between the embodiments of the present invention and the previous embodiments are: the coil structure 300 is linear. Accordingly, in the coil structure 300, the bottom conductive layers are arranged in a straight line. In this embodiment, the second bottom conductive layer 310 is used to connect to a device to be driven. When the actuator is operated, the first conductive pillar (not labeled) and the end connected to the device to be driven (i.e., the second bottom conductive layer 310) may be respectively applied with driving signals, so as to form a closed loop in the coil structure 300.

Correspondingly, the invention further provides a forming method of the actuator. Fig. 4 to 18 are schematic views illustrating an embodiment of a method for forming an actuator according to the present invention.

Referring to fig. 4, a substrate 100 is provided.

The substrate 100 is used to provide a process platform for the formation of the coil structure. In this embodiment, the substrate 100 is a semiconductor substrate, which is advantageous for improving CMOS compatibility of the formation process. For the description of the substrate 100, reference may be made to the corresponding description in the foregoing embodiments, and the description is omitted here.

In this embodiment, the substrate 100 includes at least one unit region 100S, and each unit region 100S is used to form a coil structure. The present embodiment illustrates only one cell region 100S. In other embodiments, the number of the unit regions may be multiple, so that multiple coil structures are formed on the substrate. The individual actuators can subsequently be obtained by cutting the substrate.

In this embodiment, the formation process has high CMOS compatibility, which improves the manufacturing efficiency of the actuator, for example, a plurality of coil structures may be formed on the same substrate 100.

Referring to fig. 5, a first sacrificial layer 120 is formed overlying the substrate 100.

The first sacrificial layer 120 is used to provide a process platform for the formation of the subsequent first conductive pillar, and the subsequent process further includes forming a coil structure on the first sacrificial layer 120, so that the coil structure can be formed by a semiconductor process by forming the first sacrificial layer 120.

The material of the first sacrificial layer 120 is a material that is easy to remove, so that the difficulty of the subsequent process for removing the first sacrificial layer 120 is reduced, and the damage of the process for removing the first sacrificial layer 120 to the coil structure is reduced. The material of the first sacrificial layer 120 includes silicon oxide, polycrystalline carbon, amorphous carbon, or germanium. In this embodiment, the material of the first sacrificial layer 120 is silicon oxide. The thickness of the first sacrificial layer 120 depends on the height of the first conductive pillar.

Referring to fig. 6 and 7 in combination, fig. 6 is a top view, and fig. 7 is a cross-sectional view taken along a cut line A1A2 in fig. 6, and a first conductive pillar 130 is formed to penetrate through the first sacrificial layer 120.

The first conductive pillar 130 is used to fix and support the coil structure. The coil structure has a fixed end, and the fixed end of the coil structure is connected with the first conductive column 130, so that the coil structure has a telescopic performance. Moreover, through first conductive pillar 130, make the coil structure be the unsettled state to in the time of actuator work, the coil structure can realize flexible, and in addition, first conductive pillar 130 has the electric conductivity, and in the time of actuator work, loads drive current to the coil structure through first conductive pillar 130.

In this embodiment, the subsequently formed coil structure is U-shaped, and the U-shaped coil structure has two fixed ends, so that in each unit area 100S, the number of the first conductive pillars 130 is two, and the first conductive pillars are respectively and correspondingly connected to the two fixed ends in the coil structure; accordingly, when the coil structure is loaded with the driving current through the first conductive pillar 130, a closed loop can be formed in the coil structure. In other embodiments, when the formed coil structure is linear, the number of the first conductive pillars is one in each cell region.

The material of the first conductive pillar 130 includes aluminum, tungsten, copper, arsenic germanide, or polysilicon. In the present embodiment, the first conductive pillars 130 are formed by a back end process, and the material of the first conductive pillars 130 is copper. Specifically, the step of forming the first conductive pillar 130 includes: forming a first conductive via (not shown) through the first sacrificial layer 120; the first conductive via is filled to form a first conductive pillar 130 located in the first conductive via.

In this embodiment, the first sacrificial layer 120 is etched by using an anisotropic dry etching process to form the first conductive via. The shape of the first conductive via is a regular shape. Specifically, the cross-sectional shape of the first conductive via is circular or square, and the cross-sectional shape of the first conductive pillar 130 is correspondingly circular or square.

In this embodiment, the process of forming the first conductive pillar 130 in the first conductive via includes a step of filling the first conductive via with a conductive material and a step of polishing the conductive material. Accordingly, along the height direction of the first conductive pillar 130, the upper surface and the lower surface of the first conductive pillar 130 are both planar.

Referring to fig. 4 in combination, it should be noted that before forming the first sacrificial layer 120 (shown in fig. 5) covering the substrate 100, the forming method further includes: an electrode layer 110 is formed on the substrate 100. Accordingly, in the step of forming the first sacrificial layer 120, the first sacrificial layer 120 also covers the electrode layer 110.

The material of the electrode layer 110 includes aluminum, tungsten, copper, arsenic germanide, or polysilicon. As an example, the material of the electrode layer 110 is copper. The electrode layer 110 and the first conductive pillar 130 are made of the same material, which is beneficial to improving the bonding strength between the electrode layer 110 and the first conductive pillar 130. In this embodiment, the electrode layer 110 is formed by a deposition process and an etching process which are sequentially performed. Specifically, the deposition process may be a chemical vapor deposition process, an evaporation process, a sputtering process, or an electroplating process, depending on the material of the electrode layer 110; the etching process is an anisotropic dry etching process.

As shown in fig. 7, the step of forming the first conductive pillar 130 penetrating the first sacrificial layer 120 includes: a first conductive pillar 130 is formed in the first sacrificial layer 120 above the electrode layer 110, and the first conductive pillar 130 is connected to the electrode layer 110.

In this embodiment, the first conductive pillar 130 exposes the electrode layer 110, so as to apply a driving current to the electrode layer 110. In other embodiments, an electrode layer may also be formed in a substrate, the substrate exposing a top surface of the electrode layer; for example, etching the substrate to form a recess in the substrate; and filling the groove to form an electrode layer in the groove. In other embodiments, the electrode layer may not be formed. For example, when other electrodes are provided in the substrate, the first conductive pillar is directly connected to the electrodes in the substrate.

Referring to fig. 8 and 9 in combination, fig. 8 is a top view, fig. 9 is a cross-sectional view taken along a line A1A2 in fig. 8, a plurality of bottom conductive layers 140 arranged at intervals are formed on the first sacrificial layer 120, along the arrangement direction of the bottom conductive layers 140, the bottom conductive layers 140 at the extreme edges are respectively a first bottom conductive layer 141 and a second bottom conductive layer 143, the remaining bottom conductive layers 140 located between the first bottom conductive layer 141 and the second bottom conductive layer 143 are third bottom conductive layers 142, and one end of the first bottom conductive layer 141 is correspondingly connected to the first conductive pillar 130.

The length of the bottom conductive layer 140 is used to determine the dimension of the coil structure in a direction parallel to the surface of the substrate 100. The material of the bottom conductive layer 140 includes aluminum, tungsten, copper, arsenic germanide, or polysilicon. As an example, the material of the bottom conductive layer 140 is copper. Specifically, the bottom conductive layer 140 is formed using a deposition process and an etching process, which are sequentially performed. The specific description of the deposition process and the etching process may be combined with the corresponding description in the formation of the electrode layer 110, and will not be described herein again.

In this embodiment, in each unit area 100S, the plurality of bottom conductive layers 140 are distributed in a U shape. Therefore, the projections of the first bottom conductive layer 141 and the third bottom conductive layer 142 on the sidewalls of the second bottom conductive layer 143 are located in the same second bottom conductive layer 143. Accordingly, the number of the first bottom conductive layers 141 is two, the number of the second bottom conductive layers 143 is one, and the length of the second bottom conductive layer 143 is longest among the plurality of bottom conductive layers 140. As an example, the lengths of the first and third bottom

conductive layers

141 and 142 are equal.

In this embodiment, one end of the first bottom conductive layer 141 corresponds to and is connected to the first conductive pillar 130 one by one, so that the driving current is applied to the U-shaped coil structure through the first conductive pillar 130, and a closed loop is formed in the U-shaped coil structure. Specifically, to form the U-shaped coil structure, different ends of the two first bottom conductive layers 141 are in one-to-one correspondence with and connected to the first conductive pillars 130. Specifically, in the extending direction of the bottom conductive layer 140, the bottom conductive layer 140 includes a first end 140a and a second end 140b opposite to the first end 140a, the first end 140a of one first bottom conductive layer 141 is connected to one first conductive pillar 130, and the second end 140b of another first bottom conductive layer 141 is connected to another first conductive pillar 130.

In this embodiment, the adjacent bottom conductive layers 140 have a certain interval, so that the coil structure has a telescopic function. Specifically, the plurality of bottom conductive layers 140 are arranged in parallel, thereby improving the stretching stability of the coil structure. Accordingly, the bottom conductive layers 140 extend in a first direction (as indicated by Y direction in fig. 8) and are spaced apart in a second direction (as indicated by X direction in fig. 8), the first direction and the second direction being perpendicular to each other.

It should be noted that, in other embodiments, the plurality of bottom conductive layers may also be distributed in a linear shape.

With combined reference to fig. 10 to 12, fig. 10 is a cross-sectional view based on fig. 9, fig. 11 is a top view based on fig. 10, fig. 12 is a cross-sectional view taken along line C1C2 of fig. 11, a second sacrificial layer 150 covering the first sacrificial layer 120 and the bottom conductive layer 140, and a plurality of second conductive pillars 160 penetrating the second sacrificial layer 150 are formed, and the second conductive pillars 160 are in one-to-one correspondence with and connected to both ends of the third bottom conductive layer 142, one end of the first bottom conductive layer 141 away from the first conductive pillars 130, and at least one end of the second bottom conductive layer 143. In fig. 10, a dashed box is used to indicate the outline of the bottom conductive layer 140.

The second conductive pillar 160 is also used as a part of the coil structure, and the height of the second conductive pillar 160 is used to determine the height of the coil structure. The second sacrificial layer 150 is used to provide a process platform for the formation of the second conductive pillars 160, so that the coil structure can be formed using a semiconductor process.

The material of the second sacrificial layer 150 includes silicon oxide, polycrystalline carbon, amorphous carbon, or germanium. In this embodiment, the material of the second sacrificial layer 150 is silicon oxide. The material of the second sacrificial layer 150 and the first sacrificial layer 120 is the same, which facilitates subsequent removal of the second sacrificial layer 150 and the first sacrificial layer 120 in the same step. For a detailed description of the second sacrificial layer 150, reference may be made to the above description of the first sacrificial layer 120.

The second conductive pillars 160 penetrate the second sacrificial layer 150, and thus, the thickness of the second sacrificial layer 150 depends on the height of the second conductive pillars 160. In this embodiment, one or more interconnect structure forming processes are performed to form the second sacrificial layer 150 and the second conductive pillars 160. Specifically, the process for forming the interconnection structure comprises the following steps: forming a sub-sacrificial layer (not labeled) covering the first sacrificial layer 120 and the bottom conductive layer 140; forming second conductive vias (not labeled) penetrating through the sub-sacrificial layer, where the second conductive vias correspond to positions of two ends of the third bottom conductive layer 142, one end of the first bottom conductive layer 141 far away from the first conductive pillar 130, and at least one end of the second bottom conductive layer 143 one to one; and filling the second conductive through hole to form the sub-conductive column positioned in the second conductive through hole. The sub-sacrificial layer is used to form the second sacrificial layer 150, and the sub-conductive posts are used to form the second conductive posts 160. That is, when the second sacrificial layer 150 and the second conductive pillars 160 are formed by a multi-interconnect structure forming process, the second sacrificial layer 150 and the second conductive pillars 160 are both a stacked structure. In the latter process, each metal layer or via (via) structure has a maximum height value acceptable by the process, and thus, the height of the coil structure can be adjusted by setting the number of times of the interconnection structure forming process. For example, a plurality of interconnect structure formation processes are performed to form the second conductive pillar 160 formed by stacking a plurality of sub-conductive pillars. Wherein each interconnect structure formation process is used to form a metal layer or via structure. In this embodiment, for convenience of illustration, a case of forming an interconnect structure once is illustrated. For a detailed description of the formation processes of the sub-sacrificial layer and the sub-conductive pillar, reference may be made to the related description of the first sacrificial layer 120 and the first conductive pillar 130, and details are not repeated herein.

In this embodiment, the plurality of bottom conductive layers 140 are distributed in a U shape, projections of the first bottom conductive layer 141 and the third bottom conductive layer 142 on the sidewall of the second bottom conductive layer 143 are located in the same second bottom conductive layer 143, and the second conductive pillars 160 are in one-to-one correspondence with and connected to two ends of the second bottom conductive layer 143.

Referring to fig. 13 and 14, fig. 13 is a top view, fig. 14 is a cross-sectional view taken along line B1B2 of fig. 13, a plurality of top conductive layers 170 arranged at intervals are formed on the second sacrificial layer 150, two ends of each top conductive layer 170 are sequentially connected to different ends of the adjacent bottom conductive layer 140 through the second conductive pillars 160, and the bottom conductive layer 140, the second conductive pillars 160, and the top conductive layer 170 are used for forming the coil structure 200.

One end of the first bottom conductive layer 141 is connected to the first conductive pillar 130, so that the first bottom conductive layer 141 is used as a fixed end in the coil structure 200, and the second bottom conductive layer 143 is used as a movable end in the coil structure 200, so that the coil structure 200 has a telescopic performance.

The material of the top conductive layer 170 includes aluminum, tungsten, copper, arsenic germanide, or polysilicon. In this embodiment, the top conductive layer 170 is made of copper. Specifically, the top conductive layer 170 is formed using a deposition process and an etching process, which are sequentially performed. The detailed description of the top conductive layer 170 and the formation process thereof can be combined with the corresponding description of the bottom conductive layer 140, and will not be described herein again.

Referring collectively to fig. 15, after forming the top conductive layer 170, the forming method further includes: a third sacrificial layer 180 is formed overlying the second sacrificial layer 150 and the top conductive layer 170.

The subsequent process further includes performing an etching process on the substrate 100, and during the etching process, the third sacrificial layer 180 is used to protect the coil structure 200, so as to reduce the probability that the coil structure 200 is damaged. The material of the third sacrificial layer 180 includes silicon oxide, polycrystalline carbon, amorphous carbon, or germanium. In this embodiment, the material of the third sacrificial layer 180 is silicon oxide. The detailed description of the third sacrificial layer 180 can be combined with the related description of the second sacrificial layer 150, and is not repeated herein.

Referring to fig. 16, the substrate 100 is etched from a side of the substrate 100 opposite to the coil structure 200, and an opening 105 penetrating the substrate 100 and exposing the coil structure 200 is formed in the substrate 100.

By forming the opening 105, the actuator can be applied to an imaging module. Specifically, the second bottom conductive layer 143 is used for connecting to a device to be driven, and the imaging module generally includes an image sensor and a lens assembly located above the image sensor, and the lens assembly includes a lens, and when the image sensor or the flexible lens is used as the device to be driven, through the opening 105, the optical signal can penetrate through the flexible lens and be received by the image sensor, so as to ensure the normal use performance of the imaging module. In the present embodiment, the openings 105 correspond to the coil structures 200, that is, each opening 105 corresponds to a cell region 100S.

In this embodiment, the substrate 100 is etched using a dry etching process (e.g., an anisotropic dry etching process). It should be noted that, during the etching process, the first sacrificial layer 120, the second sacrificial layer 150, and the third sacrificial layer 180 play a role of protecting the coil structure 200. Accordingly, after the opening 105 is formed, the opening 105 exposes the first sacrificial layer 120. In other embodiments, the substrate may also be etched after the second sacrificial layer and the first sacrificial layer are removed; in this case, the third sacrificial layer does not need to be formed. In still other embodiments, depending on the use scenario of the actuator, the opening may not be formed; alternatively, the substrate may be removed during the etching process to reduce the thickness of the stopper. In other embodiments, when the number of the cell regions is plural, after forming an opening in the substrate and removing the third sacrificial layer, the second sacrificial layer, and the first sacrificial layer, the method further includes: the substrate is cut to obtain individual actuators.

Referring to fig. 17 and 18 in combination, fig. 17 is a top view, and fig. 18 is a cross-sectional view of fig. 17 taken along a cut line B1B2, and the third sacrificial layer 180, the second sacrificial layer 150 and the first sacrificial layer 120 are removed.

By removing the third sacrificial layer 180, the second sacrificial layer 150 and the first sacrificial layer 120, the coil structure 200 can be expanded and contracted after being electrified, so that the normal use function of the actuator is realized.

In this embodiment, in order to prevent plasma damage to the coil structure 200 and to completely remove the third sacrificial layer 180, the second sacrificial layer 150, and the first sacrificial layer 120, a wet etching process is used to remove the third sacrificial layer 180, the second sacrificial layer 150, and the first sacrificial layer 120. Specifically, the etching solution is a hydrofluoric acid solution. In other embodiments, when the material of any one of the third sacrificial layer, the second sacrificial layer and the first sacrificial layer is amorphous carbon, the corresponding sacrificial layer is removed by an ashing process.

In the embodiment, by forming the coil structure 200, the structural complexity and the use complexity of the actuator are reduced, and the forming process of the actuator has higher CMOS compatibility, which reduces the manufacturing difficulty of the actuator, and in addition, the weight of the actuator formed by using a semiconductor process is lighter, which is beneficial to improving the reaction rate of the actuator and correspondingly improving the performance of the actuator; in summary, the forming method of the embodiment can improve the performance of the actuator while reducing the manufacturing difficulty, the structural complexity and the use complexity of the actuator.

Accordingly, the present invention also provides a driving method of the actuator of the foregoing embodiment.

Fig. 19 to 20 are schematic views illustrating a driving method of an actuator according to an embodiment of the present invention. Fig. 19 shows a state of the coil structure when the drive current is not applied to the coil structure, and fig. 20 shows a state of the coil structure when the drive current is applied to the coil structure.

The driving method provided by the embodiment of the invention is used for driving the actuator provided by the previous embodiment, so that the coil structure 200 in the actuator is stretched and contracted, and further, the movement or stretching of the device to be driven is realized.

By the driving method, the coils in the coil structure 200 can attract each other, so that the coil structure 200 contracts, that is, generates a displacement amount, and the contraction amount of the coil structure 200 can be controlled by controlling the magnitude of the driving current, wherein in the coil structure 200, the second bottom conductive layer is used for being connected with a device to be driven, and the displacement amount or the stretching amount of the device to be driven is correspondingly controlled by controlling the contraction of the coil structure 200, in conclusion, the coil structure 200 is used for forming the actuator, thereby reducing the use complexity of the actuator.

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

Referring to fig. 19 and 20 in combination, the driving method includes: a displacement process is performed, and a driving current is applied to the coil structure 200 through the first conductive pillar 130 (as shown in fig. 1), so that an electromagnetic field is formed around the coil structure 200, for enabling the coil structure 200 to contract along the arrangement direction of the bottom conductive layer.

Specifically, as shown in fig. 20, the coil structure 200 is a spiral tube, when the coil structure 200 is loaded with a driving current, the coil structure 200 can be regarded as an energized solenoid, and when the coil passes through the driving current, an electromagnetic field is generated around the coil, so that the coils attract each other, and the coil structure 200 contracts.

In this embodiment, in the coil structure 200, the plurality of bottom conductive layers 140 (shown in fig. 1) are arranged in parallel, the plurality of bottom conductive layers 140 extend along a first direction (shown as Y direction in fig. 1) and are arranged at intervals along a second direction (shown as X direction in fig. 1), and the first direction and the second direction are perpendicular to each other, so that the electromagnetic field is used to shrink the coil structure 200 along the second direction.

In the actuator, the second bottom conductive layer 143 (shown in fig. 1) is used for connecting to the device to be driven, so that when the actuator is connected to the same end of the device to be driven, the coil structure 200 contracts, and horizontal movement of the device to be driven can be achieved; or, when the plurality of actuators are arranged around the to-be-driven device at equal angles along the circumferential direction, the coil structure 200 contracts, so that the to-be-driven device can be stretched in the horizontal plane direction, and the shape of the to-be-driven device is changed. Correspondingly, the displacement or stretching amount of the device to be driven is correspondingly controlled by controlling the magnitude of the driving current. During the displacement process, the driving current can be adjusted until the shrinkage of the coil structure 200 meets the actual requirement.

As an example, the actuator further comprises: an electrode layer 110 on the substrate 100; the first conductive pillar 130 is located on the electrode layer 110, and the first conductive pillar 130 is connected to the electrode layer 110. A driving current is applied to the coil structure 200 through the electrode layer 110, that is, the electrode layer 110 is applied with a driving current, so that the current is transmitted to the coil structure 200 through the first conductive pillar 130.

Therefore, in this embodiment, after the displacement processing is completed, the driving method further includes: the displacement recovery process is performed to stop the drive current from being applied to the coil structure 200, and the electromagnetic field around the coil structure 200 is eliminated to recover the coil structure 200.

The device to be driven is restored to the original position or to the original shape by restoring the coil structure 200 to the original state. Wherein, coil structure 200 is the spiral pipe, and coil structure 200 can be regarded as having elasticity, and after stopping to coil structure 200 loading drive current, the electromagnetic field around coil structure 200 disappears, and under the effect of elastic force, coil structure 200 reconversion.

In this embodiment, the actuator can realize its expansion and contraction function by loading the driving current, thereby reducing the use complexity of the actuator. Moreover, the actuator is formed by using a semiconductor process, and the weight of the actuator formed by using the semiconductor process is light, which is beneficial to improving the reaction rate of the actuator.

Correspondingly, the embodiment of the invention also provides the electronic equipment. FIG. 21 is a diagram of an electronic device according to an embodiment of the invention.

The electronic device 700 of the embodiment of the present invention includes: a device to be driven; at least one of the foregoing embodiments provides an actuator in which the second bottom conductive layer is connected to a device to be driven. The device to be driven comprises an image sensor, a radio frequency generator, a lens, a prism, a grating or a waveguide.

The material of the device to be driven is flexible. Therefore, under the condition that the actuators are arranged around the to-be-driven device at equal angles along the circumferential direction, the coil structure contracts, so that the to-be-driven device can be stretched in the horizontal plane direction, and the appearance of the to-be-driven device is changed. The actuators are arranged around the device to be driven at equal angles along the circumferential direction, so that the stress uniformity of the device to be driven is improved.

The device to be driven is moved or stretched by the actuator, and the contraction quantity of the coil structure is controlled by controlling the magnitude of the driving current, so that the use complexity of the actuator is correspondingly reduced, in addition, the precision of the contraction quantity of the coil structure is higher, the displacement quantity or stretching quantity of the device to be driven can be accurately controlled, the weight of the actuator is lighter, and therefore the reaction rate of the actuator is favorably improved. The electronic device 700 may be an intermediate component, such as: imaging modules, lens assemblies, and the like. The electronic device 700 may also be a terminal device, such as: the electronic device 700 may be various devices having a photographing function, such as a mobile phone, a tablet computer, a camera, and a video camera.

As an example, in the actuator, the second bottom conductive layer may be connected to the device to be driven through an adhesive layer. Specifically, the device to be driven may be fixed to a side wall of the second bottom conductive layer on a side facing away from the third bottom conductive layer, or fixed to an upper surface of the second bottom conductive layer, or fixed to a lower surface of the second bottom conductive layer.

In some embodiments, in the electronic device 700, the number of the actuators is one or more, and one or more actuators are connected to the same end of the device to be driven, so that when the coil structure contracts, the device to be driven can be horizontally moved. In other embodiments, the number of the actuators is multiple, the multiple actuators are arranged around the to-be-driven device at equal angles along the circumferential direction, and when the coil structure contracts, the to-be-driven device can be stretched in the horizontal plane direction, so that the appearance of the to-be-driven device is changed.

As an example, the electronic device 700 is an imaging module, the actuator is integrated in a lens assembly in the imaging module, and the device to be driven is a flexible lens. The number of the actuators is multiple, the actuators are arranged around the device to be driven at equal angles along the circumferential direction, and in each actuator, the second bottom conducting layer is connected with the device to be driven. The corresponding displacement of each actuator is controlled, so that the flexible lens is stretched, and focusing is realized. The amount of contraction of the coil structure can be accurately controlled by controlling the magnitude of the driving current, so that the focusing efficiency and accuracy of the electronic device 700 are improved, and the imaging quality is correspondingly improved.

In other embodiments, when the electronic device is a terminal device with a shooting function, the actuator according to the embodiments of the present invention can also improve the focusing efficiency and accuracy of the imaging module, and accordingly improve the imaging quality, for example: the imaging definition is improved, so that the shooting quality of the electronic equipment is improved, and the use experience of a user is improved.

Correspondingly, an embodiment of the present invention further provides an imaging module, including: an image sensor; a lens assembly corresponding to an image sensor, the lens assembly comprising: the device to be driven is a flexible lens and corresponds to the image sensor; the actuators provided by the embodiment of the invention are arranged around the device to be driven at equal angles along the circumferential direction, and in each actuator, the second bottom conductive layer is connected with the device to be driven. Specifically, the image sensor includes a CMOS image sensor or a CCD image sensor.

In this embodiment, the flexible lens is stretched by controlling the displacement amount corresponding to each actuator, so as to achieve focusing. The shrinkage of the coil structure can be accurately controlled by controlling the magnitude of the driving current, so that the focusing efficiency and accuracy of the imaging module are improved, and the imaging quality is correspondingly improved.

In some embodiments, when the actuator further comprises a substrate, in each actuator there is an opening in the substrate through the substrate, the opening exposing the coil structure. The lens subassembly is located the image sensor top, through set up the opening that exposes the coil structure in the substrate for light signal can see through flexible lens and is received by image sensor, thereby has ensured imaging module's normal performance.

Correspondingly, an embodiment of the present invention further provides an imaging module, including: the device to be driven is an image sensor; one or more actuators provided by embodiments of the present invention, each actuator connected to the same end of the device to be driven, in each actuator, the second bottom conductive layer connected to the device to be driven; a lens assembly corresponding to the image sensor. Specifically, the image sensor includes a CMOS image sensor or a CCD image sensor.

The image sensor is translated by controlling the displacement corresponding to each actuator, the lens assembly corresponds to the image sensor and is positioned above the image sensor so as to adjust a light path and clearly image; therefore, the image sensor is moved through the actuator, so that the image sensor compensates displacement of an imaging point, optical anti-shaking is achieved, the size of the image sensor is small, the weight of the image sensor is low, the optical anti-shaking is achieved through the movement of the image sensor, cost is saved, and convenience and stability of the optical anti-shaking are improved. Wherein, through the size of control drive current, can accurate control coil structure's shrinkage to the realization is to image sensor's accurate translation, and then improves the validity and the accuracy nature that the formation of image module is used for optics anti-shake correspondingly improve image quality.

In some embodiments, when the actuator further comprises a substrate, in each actuator there is an opening through the substrate in the substrate, the opening exposing the coil structure. The lens subassembly is located image sensor top for light signal can see through flexible lens and is received by image sensor through set up the opening that exposes the coil structure in the substrate, thereby has ensured imaging module's normal performance.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An actuator for moving or stretching a device to be driven, comprising:

a first conductive pillar;

a coil structure, connected to the first conductive pillar, the coil structure including:

the bottom conducting layers at the outermost edges are respectively a first bottom conducting layer and a second bottom conducting layer along the arrangement direction of the bottom conducting layers, the rest bottom conducting layers between the first bottom conducting layer and the second bottom conducting layer are third bottom conducting layers, one end of the first bottom conducting layer is connected with the first conducting column, and the upper surface and the lower surface of the bottom conducting layer are planes;

the second conductive columns are vertically positioned on the bottom conducting layer, and are in one-to-one correspondence with and connected with two ends of the third bottom conducting layer, one end of the first bottom conducting layer, which is far away from the first conductive columns, and at least one end of the second bottom conducting layer;

the top conducting layers are arranged at intervals and suspended on the bottom conducting layers, two ends of each top conducting layer sequentially connect different ends of the adjacent bottom conducting layers through the second conducting posts, and at least the lower surfaces of the top conducting layers are planes;

the second bottom conducting layer is used for being connected with the device to be driven;

the actuator is configured to perform a displacement process and a displacement recovery process, the displacement process including: loading a driving current to the coil structure through the first conductive column, so that an electromagnetic field is formed around the coil structure, wherein the electromagnetic field is used for enabling the coil structure to contract along the arrangement direction of the bottom conductive layer, and the displacement recovery processing comprises the following steps: and stopping loading the driving current to the coil structure, so that the electromagnetic field around the coil structure disappears, and the coil structure is restored.

2. The actuator of claim 1, wherein the coil structure is U-shaped;

the bottom conducting layers are distributed in a U shape, and the projections of the first bottom conducting layer and the third bottom conducting layer on the side wall of the second bottom conducting layer are positioned in the same second bottom conducting layer;

the second conductive columns correspond to and are connected with two ends of the second bottom conductive layer one by one.

3. The actuator of claim 1, wherein a plurality of said bottom conductive layers are arranged in parallel.

4. The actuator of claim 1, further comprising: a substrate;

the first conductive column is positioned on the substrate;

the coil structure is suspended on the substrate.

5. The actuator of claim 4, further comprising: an electrode layer on the substrate; or the electrode layer is positioned in the substrate, and the top surface of the electrode layer is exposed out of the substrate;

the first conductive column is located on the electrode layer, and the first conductive column is connected with the electrode layer.

6. The actuator of claim 1, wherein the second conductive post comprises one or more stacked sub-conductive posts along a height direction of the second conductive post.

7. The actuator of claim 1, wherein the coil structure is positioned over the first conductive post and is connected to a top surface of the first conductive post.

8. The actuator of claim 1, wherein the material of any of the first conductive post, the bottom conductive layer, the second conductive post, and the top conductive layer comprises aluminum, tungsten, copper, arsenic germanide, or polysilicon.

9. The actuator of claim 4, wherein the substrate has an opening therethrough;

wherein the opening exposes the coil structure.

10. A method of forming an actuator, comprising:

providing a substrate;

forming a first sacrificial layer overlying the substrate;

forming a first conductive pillar through the first sacrificial layer;

forming a plurality of bottom conductive layers arranged at intervals on the first sacrificial layer, wherein the bottom conductive layers at the outermost edges are a first bottom conductive layer and a second bottom conductive layer respectively along the arrangement direction of the bottom conductive layers, the rest bottom conductive layers between the first bottom conductive layer and the second bottom conductive layer are third bottom conductive layers, and one end of the first bottom conductive layer is connected with the first conductive column;

forming a second sacrificial layer covering the first sacrificial layer and the bottom conductive layer, and a plurality of second conductive pillars penetrating through the second sacrificial layer, wherein the second conductive pillars are in one-to-one correspondence with and connected to two ends of the third bottom conductive layer, one end of the first bottom conductive layer, which is far away from the first conductive pillars, and at least one end of the second bottom conductive layer;

forming a plurality of top conductive layers arranged at intervals on the second sacrificial layer, wherein two ends of each top conductive layer sequentially connect different ends of the adjacent bottom conductive layers through the second conductive posts, and the bottom conductive layers, the second conductive posts and the top conductive layers are used for forming a coil structure;

and after the top conductive layer is formed, removing the second sacrificial layer and the first sacrificial layer.

11. The method according to claim 10, wherein in the step of forming a plurality of spaced bottom conductive layers on the first sacrificial layer, the plurality of bottom conductive layers are distributed in a U shape, and projections of the first bottom conductive layer and the third bottom conductive layer on sidewalls of the second bottom conductive layer are located in the same second bottom conductive layer;

in the step of forming a second sacrificial layer covering the first sacrificial layer and the bottom conductive layer, and a plurality of second conductive pillars penetrating through the second sacrificial layer, the second conductive pillars correspond to and are connected to two ends of the second bottom conductive layer one to one.

12. The method of forming of claim 10, wherein prior to forming the first sacrificial layer overlying the substrate, the method of forming further comprises: forming an electrode layer on or in the substrate, wherein the top surface of the electrode layer is exposed from the substrate;

the step of forming a first conductive pillar through the first sacrificial layer comprises: and forming a first conductive pillar in the first sacrificial layer above the electrode layer, wherein the first conductive pillar is connected with the electrode layer.

13. The method of forming of claim 10, wherein after forming the top conductive layer, the method of forming the actuator further comprises: etching the substrate from one side of the substrate, which is back to the coil structure, and forming an opening which penetrates through the substrate and exposes the coil structure in the substrate, wherein the opening corresponds to the coil structure;

or,

and etching the substrate from one side of the substrate, which is back to the coil structure, and removing the substrate.

14. The forming method according to claim 13, wherein after removing the second sacrificial layer and the first sacrificial layer, the substrate is subjected to etching treatment from a side of the substrate facing away from the coil structure;

or,

and removing the second sacrificial layer and the first sacrificial layer after etching the substrate from the side of the substrate, which faces away from the coil structure.

15. The forming method according to claim 13, wherein after the etching process is performed on the substrate from a side of the substrate facing away from the coil structure, the second sacrificial layer and the first sacrificial layer are removed;

after forming the plurality of top conductive layers arranged at intervals on the second sacrificial layer and before etching the substrate from a side of the substrate facing away from the coil structure, the method for forming the actuator further includes: forming a third sacrificial layer covering the second sacrificial layer and the top conductive layer;

after the etching process is performed on the substrate from the side of the substrate facing away from the coil structure, the method for forming the actuator further includes: and removing the third sacrificial layer.

16. The method of forming of claim 10, wherein forming a first conductive pillar through the first sacrificial layer comprises: forming a first conductive via through the first sacrificial layer; and filling the first conductive through hole to form a first conductive column positioned in the first conductive through hole.

17. The method of forming of claim 10, wherein one or more interconnect structure forming processes are performed to form a second sacrificial layer covering the first sacrificial layer and bottom conductive layer, and a plurality of second conductive pillars penetrating the second sacrificial layer;

the forming process of the interconnection structure comprises the following steps: forming a sub-sacrificial layer covering the first sacrificial layer and the bottom conductive layer; forming second conductive through holes penetrating through the sub-sacrificial layer, wherein the second conductive through holes correspond to the two ends of the third bottom conductive layer, one end of the first bottom conductive layer far away from the first conductive column and at least one end of the second bottom conductive layer in a one-to-one mode; filling the second conductive through hole to form a sub-conductive column positioned in the second conductive through hole;

wherein the sub-sacrificial layer is used for constituting the second sacrificial layer, and the sub-conductive pillars are used for constituting the second conductive pillars.

18. The method of claim 10, wherein in the step of forming a plurality of spaced apart bottom conductive layers on the first sacrificial layer, the plurality of bottom conductive layers are arranged in parallel.

19. The forming method of claim 10, wherein the second sacrificial layer and the first sacrificial layer are removed using a wet etching process or an ashing process.

20. The formation method of claim 15, wherein the third sacrificial layer is removed using a wet etching process or an ashing process.

21. The forming method of claim 10, wherein a material of any one of the first sacrificial layer and the second sacrificial layer comprises silicon oxide, polycrystalline carbon, amorphous carbon, or germanium.

22. The method of claim 15, wherein a material of the third sacrificial layer comprises silicon oxide, polycrystalline carbon, amorphous carbon, or germanium.

23. A driving method of the actuator according to any one of claims 1 to 9, comprising:

performing displacement processing, namely loading a driving current to the coil structure through the first conductive column to form an electromagnetic field around the coil structure, wherein the electromagnetic field is used for enabling the coil structure to contract along the arrangement direction of the bottom conductive layer;

and executing displacement recovery processing, and stopping loading the driving current to the coil structure to eliminate the electromagnetic field around the coil structure so as to recover the coil structure.

24. An electronic device, comprising:

a device to be driven;

at least one actuator according to any of claims 1 to 9, in which the second bottom conductive layer is connected to the device to be driven.

25. The electronic device of claim 24, wherein the number of the actuators is one or more, and the one or more actuators are connected to the same end of the device to be driven;

or,

the number of the actuators is multiple, and the multiple actuators are arranged around the device to be driven at equal angles along the circumferential direction.

26. The electronic device of claim 24, wherein the device to be driven comprises an image sensor, a radio frequency generator, a mirror, a prism, a grating, or a waveguide.

27. An imaging module, comprising:

an image sensor;

a lens assembly corresponding to the image sensor, the lens assembly comprising: the device to be driven is a flexible lens and corresponds to the image sensor; a plurality of actuators according to any one of claims 1 to 9, arranged at equal angles around the device to be driven in the circumferential direction, wherein in each of the actuators, the second bottom conductive layer is connected to the device to be driven.

28. An imaging module, comprising:

a device to be driven, the device to be driven being an image sensor;

one or more actuators as claimed in any one of claims 1 to 9, each of said actuators being connected to the same end of said device to be driven, in each of said actuators said second bottom conductive layer being connected to said device to be driven;

a lens assembly corresponding to the image sensor.