阅读说明：本技术 等离子设备 (Plasma equipment ) 是由 吕尚亿 梁冠雄 丁雪苗 赵芝强 赵公魄 于 2021-10-20 设计创作，主要内容包括：本发明涉及一种等离子设备,等离子设备包括等离子发生组件、气流引导结构及进气组件,等离子发生组件包括两个等离子电极。两个间隔设置的等离子电极形成等离子腔,以使等离子腔能够形成等离子场。当进气组件通过进气口进气至等离子腔内,实现气体在等离子腔内的电离,形成等离子气体。由于气流引导结构设置于进气口处,气流引导结构上的分流孔与等离子腔连通,进而进气组件通过气流引导结构进气至等离子腔内时,需要经过分流孔的引流。利用气流引导结构上的分流孔,实现对进气组件喷出的气流的引导引流作用,进而便于使得气流通过分流孔后能够更加均匀地分布于等离子腔内,提高等离子体的产生效率,进而提高等离子体处理的效率。(The invention relates to plasma equipment which comprises a plasma generation assembly, an air flow guide structure and an air inlet assembly, wherein the plasma generation assembly comprises two plasma electrodes. Two spaced apart plasma electrodes form a plasma chamber to enable the plasma chamber to form a plasma field. When the air inlet assembly is used for introducing air into the plasma cavity through the air inlet, ionization of the air in the plasma cavity is realized, and plasma air is formed. Because the air current guide structure sets up in inlet port department, the last reposition of redundant personnel hole of air current guide structure and plasma chamber intercommunication, and then when the subassembly of admitting air admits air to the plasma chamber through the air current guide structure, need pass through the drainage of reposition of redundant personnel hole. Utilize the reposition of redundant personnel hole on the air current guide structure, realize the guide drainage effect to the subassembly spun air current that admits air, and then be convenient for make the air current can distribute in the plasma intracavity more evenly after passing through the reposition of redundant personnel hole, improve plasma's production efficiency, and then improve plasma processing's efficiency.)

1. A plasma apparatus, characterized in that the plasma apparatus comprises:

the plasma generating assembly comprises two plasma electrodes which are arranged at intervals, a space between the two plasma electrodes is formed into a plasma cavity, and an air inlet communicated with the plasma cavity is formed at the interval between one side edges of the two plasma electrodes;

the gas flow guiding structure is provided with at least two shunting holes, the shunting holes are arranged at intervals, and the gas flow guiding structure is arranged at the gas inlet so as to enable the shunting holes to be communicated with the plasma cavity; and

the air inlet assembly is arranged on one side, back to the plasma cavity, of the air flow guide structure, and the air inlet assembly can enter air into the plasma cavity through the flow dividing holes.

2. The plasma apparatus of claim 1, wherein the gas flow guide structure is disposed between two of the plasma electrodes with a spacing between a side of the gas flow guide structure facing the plasma electrodes.

3. The plasma apparatus of claim 2, wherein the gas inlet assembly comprises at least two gas inlet conduits disposed on a side of the gas flow guide structure facing away from the plasma chamber, and wherein at least one pair of gas inlet conduits is located in a gap between the gas flow guide structure and one of the plasma electrodes and at least another pair of gas inlet conduits is located in a gap between the gas flow guide structure and another of the plasma electrodes.

4. The plasma apparatus of claim 1, wherein the number of the branch holes is plural, the plural branch holes are arranged at intervals, and the arrangement direction of the plural branch holes intersects with a direction of one of the plasma electrodes toward the other of the plasma electrodes.

5. The plasma apparatus of claim 4, wherein the size of the splitter orifice is inversely related to the gas flow rate at the location of the splitter orifice.

6. The plasma apparatus of claim 4, wherein the distribution density of each of the splitter holes on the gas flow guide structure is inversely related to the gas flow rate at the position of the splitter hole.

7. The plasma apparatus of any of claims 1-6, wherein a surface of the gas flow directing structure facing the gas inlet assembly is a smooth flat surface or a smooth curved surface.

8. The plasma apparatus according to any one of claims 1 to 6, further comprising a material placement frame, wherein the material placement frame is disposed in the plasma chamber and spaced from the plasma electrode, a material placement slot is formed in the material placement frame, the material placement slot penetrates through one side of the material placement frame facing the air inlet to form a communication port, and the airflow guiding structure is disposed on the communication port of the material placement frame and covers the communication port, so that the diversion hole is communicated with the material placement slot.

9. The plasma apparatus of claim 8, wherein the communication port has a size larger than the size of the diversion hole.

10. The plasma apparatus of any of claims 1-6, further comprising a plasma chamber, wherein the plasma electrode is disposed within the plasma chamber, wherein the gas inlet is formed in a top wall of the plasma chamber, and wherein the gas inlet assembly is disposed on the top wall of the plasma chamber.

Technical Field

The invention relates to the technical field of plasma, in particular to plasma equipment.

Background

The plasma processing equipment is widely applied to occasions such as plasma cleaning, etching, plasma plating, plasma coating, plasma ashing, surface activation, modification and the like. However, in the conventional plasma processing apparatus, the gas enters the plasma space formed between the two electrodes, and the gas flow is not uniformly distributed between the two electrodes, so that the plasma distribution between the two electrodes is not uniform, and the gas is only partially ionized between the electrodes, so that the efficiency of generating plasma is low, and the efficiency of performing plasma processing is reduced.

Disclosure of Invention

In order to solve the problems, the invention provides a plasma device which can improve the uniformity of gas distribution and further improve the plasma processing efficiency.

A plasma device comprises a plasma generation assembly, an air flow guide structure and an air inlet assembly, wherein the plasma generation assembly comprises two plasma electrodes which are arranged at intervals, a space between the two plasma electrodes is formed into a plasma cavity, and an air inlet communicated with the plasma cavity is formed at the interval between one side edges of the two plasma electrodes; the gas flow guiding structure is provided with at least two shunting holes, the shunting holes are arranged at intervals, and the gas flow guiding structure is arranged at the gas inlet so as to enable the shunting holes to be communicated with the plasma cavity; the air inlet assembly is arranged on one side of the air flow guide structure, which is back to the plasma cavity, and the air inlet assembly can be used for introducing air into the plasma cavity through the flow dividing hole.

In one embodiment, the gas flow guiding structure is disposed between two of the plasma electrodes, and a side of the gas flow guiding structure facing the plasma electrodes is spaced apart from the plasma electrodes.

In one embodiment, the gas inlet assembly includes at least two gas inlet pipes, at least two gas inlet pipes are disposed on a side of the gas flow guiding structure facing away from the plasma chamber, and at least one pair of the gas inlet pipes is located in a gap between the gas flow guiding structure and one of the plasma electrodes, and at least another pair of the gas inlet pipes is located in a gap between the gas flow guiding structure and another of the plasma electrodes.

In one embodiment, the number of the shunting holes is multiple, the plurality of shunting holes are arranged at intervals, and the arrangement direction of the plurality of shunting holes intersects with the direction of one plasma electrode facing to the other plasma electrode.

In one embodiment, the size of the splitter orifice is inversely related to the flow rate of the gas stream at the location of the splitter orifice.

In one embodiment, the distribution density of each of the splitter holes on the airflow guiding structure is in a negative correlation with the airflow speed at the position of the splitter hole.

In one embodiment, the surface of the airflow guiding structure facing the air intake component is a smooth plane or a smooth cambered surface.

In one embodiment, the plasma device further includes a material placing frame, the material placing frame is disposed in the plasma cavity and spaced from the plasma electrode, a material placing slot is formed in the material placing frame, the material placing slot penetrates through one side of the material placing frame, which faces the air inlet, to form a communicating opening, and the airflow guiding structure is disposed on the communicating opening of the material placing frame and covers the communicating opening, so that the diversion hole is communicated with the material placing slot.

In one embodiment, the communication port is larger in size than the diversion hole.

In one embodiment, the plasma apparatus further includes a plasma chamber, the plasma electrode is disposed in the plasma chamber, the gas inlet is formed on a top wall of the plasma chamber, and the gas inlet assembly is disposed on the top wall of the plasma chamber.

In the plasma equipment, the two plasma electrodes arranged at intervals form a plasma cavity so that the plasma cavity can form a plasma field. When the air inlet assembly is used for introducing air into the plasma cavity through the air inlet, ionization of the air in the plasma cavity is realized, and plasma air is formed. Because the air current guide structure sets up in inlet port department, the last reposition of redundant personnel hole of air current guide structure and plasma chamber intercommunication, and then when the subassembly of admitting air admits air to the plasma chamber through the air current guide structure, need pass through the drainage of reposition of redundant personnel hole. Utilize the reposition of redundant personnel hole on the air current guide structure, realize the guide drainage effect to the subassembly spun air current that admits air, and then be convenient for make the air current can distribute in the plasma intracavity more evenly after passing through the reposition of redundant personnel hole, improve plasma's production efficiency, and then improve plasma processing's efficiency.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention.

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Furthermore, the drawings are not to scale of 1:1, and the relative dimensions of the various elements in the drawings are drawn only by way of example and not necessarily to true scale. In the drawings:

FIG. 1 is a top view of a plasma apparatus in one embodiment;

FIG. 2 is a schematic view of a partial structure of the plasma apparatus shown in FIG. 1;

FIG. 3 is a side view of the airflow directing structure of FIG. 2;

FIG. 4 is a top view of the airflow directing structure shown in FIG. 3;

FIG. 5 is an enlarged view taken at A in FIG. 3;

fig. 6 is an enlarged view at B in fig. 1.

Description of reference numerals:

10. a plasma device; 100. a plasma generating assembly; 110. a plasma electrode; 120. a plasma chamber; 130. an air inlet; 200. an airflow directing structure; 210. a shunt hole; 220. an installation part; 222. mounting holes; 230. an abutting portion; 300. an air intake assembly; 310. an air intake duct; 400. a material placing frame; 410. a material placing slot; 500. a plasma chamber.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Referring to fig. 1 to 3, a plasma apparatus 10 according to an embodiment of the present invention is used to perform plasma processing. Specifically, the plasma apparatus 10 includes a plasma generation assembly 100, a gas flow guide structure 200, and a gas inlet assembly 300. The plasma generating assembly 100 comprises two plasma electrodes 110, the two plasma electrodes 110 are arranged at intervals, a space between the two plasma electrodes 110 is formed into a plasma cavity 120, and an air inlet 130 communicated with the plasma cavity 120 is formed at an interval between one side edges of the two plasma electrodes 110; the gas flow guiding structure 200 is provided with at least two branch flow holes 210, the branch flow holes 210 are arranged at intervals, and the gas flow guiding structure 200 is arranged at the gas inlet 130 so as to communicate the branch flow holes 210 with the plasma chamber 120; the gas inlet assembly 300 is disposed at a side of the gas flow guiding structure 200 facing away from the plasma chamber 120, and the gas inlet assembly 300 can inlet gas into the plasma chamber 120 through the flow dividing hole 210.

When the gas inlet assembly 300 is used for introducing gas into the plasma chamber 120 through the gas inlet 130, the gas is ionized in the plasma chamber 120 to form plasma gas. Because the airflow guiding structure 200 is disposed at the air inlet 130, the diversion holes 210 on the airflow guiding structure 200 are communicated with the plasma chamber 120, and when the air inlet assembly 300 enters the plasma chamber 120 through the airflow guiding structure 200, the air needs to be guided through the diversion holes 210. By utilizing the diversion holes 210 on the airflow guiding structure 200, the guiding and drainage effects on the airflow ejected by the air intake assembly 300 are realized, so that the airflow can be more uniformly distributed in the plasma cavity 120 after passing through the diversion holes 210, the generation efficiency of the plasma is improved, and the plasma processing efficiency is further improved.

Referring to fig. 2 and 3, in an embodiment, the gas flow guiding structure 200 is disposed between two plasma electrodes 110, and a side of the gas flow guiding structure 200 facing the plasma electrodes 110 is spaced apart from the plasma electrodes 110. Specifically, two opposite sidewalls of the gas flow guiding structure 200 are spaced apart from the plasma electrode 110 opposite thereto. When the gas inlet assembly 300 is introduced through the side of the gas flow guide structure 200 facing away from the plasma chamber 120, a portion of the gas flow is allowed to enter the plasma chamber 120 through the diverging holes 210 of the gas flow guide structure 200, and the other portion may enter the plasma chamber 120 through the gap between the gas flow guide structure 200 and the plasma electrode 110.

In the present embodiment, the plasma electrode 110 has a plate-like structure, and the plate surfaces of the two plasma electrodes 110 are spaced from each other, thereby forming the flat box-like plasma chamber 120. The gas inlet 130 is formed at one side of the two plasma electrodes 110. The gas flow guiding structure 200 is a strip structure, and the long side of the gas flow guiding structure 200 is opposite to the plasma electrode 110, so that the gas flow guiding structure 200 is conveniently spaced from the plasma electrode 110. When the gas flow reaches the side of the gas flow guiding structure 200 opposite to the plasma chamber 120, the gas flow can be divided into three parts, wherein the two parts of the gas flow enter the plasma chamber 120 through the gap between the gas flow guiding structure 200 and the two sides of the plasma electrode 110, and the workpiece to be processed is disposed in the plasma chamber 120, so that the two parts of the gas flow are distributed on the two opposite sides of the workpiece to be processed. And the other part enters the plasma chamber 120 through the diversion holes 210, which can be understood as entering the plasma chamber 120 from the top wall side of the workpiece to be processed, and the part of the gas flow can be uniformly diffused to the two opposite surfaces of the workpiece to be processed, so as to further uniform the uniformity of the gas flow on the two opposite surfaces of the workpiece to be processed.

In other embodiments, there may also be no space between the gas flow directing structure 200 and the plasma electrode 110, and the gas flow enters the plasma chamber 120 through the splitter holes 210 of the gas flow directing structure 200.

In this embodiment, the gas inlet assembly 300 includes at least two gas inlet pipes 310, at least two gas inlet pipes 310 are disposed on a side of the gas flow guiding structure 200 facing away from the plasma chamber 120, and at least one of the gas inlet pipes 310 is aligned with a gap between the gas flow guiding structure 200 and one of the plasma electrodes 110, and at least another gas inlet pipe 310 is aligned with a gap between the gas flow guiding structure 200 and another of the plasma electrodes 110. By providing at least two air inlet ducts 310 respectively facing the gaps between the air flow guiding structure 200 and the two plasma electrodes 110, the air inlet efficiency and the uniformity of air inlet can be further improved.

In other embodiments, the gas inlet duct 310 may also be aligned with the gas flow directing structure 200 such that gas ejected from the gas inlet duct 310 is directed at the gas flow directing structure 200 to facilitate gas flow through the splitter holes 210 into the plasma chamber 120.

In this embodiment, the number of the diversion holes 210 is multiple, the plurality of diversion holes 210 are arranged at intervals, and the arrangement direction of the plurality of diversion holes 210 intersects with the direction of one plasma electrode 110 facing the other plasma electrode 110. Because the plasma cavity 120 is formed between the two plasma electrodes 110, the plurality of the diversion holes 210 are arranged, so that the gas flow is more uniformly diverted to different positions of the plasma cavity 120, and the uniformity of the gas flow entering the plasma cavity 120 is further improved.

Specifically, the airflow guiding structure 200 is a strip-shaped structure, and the plurality of branch flow holes 210 are arranged at intervals along the length direction of the airflow guiding structure 200. In this embodiment, since the plasma chamber 120 is a flat box-shaped chamber, the plurality of diverging holes 210 are arranged at intervals along the length direction of the plasma chamber 120, which facilitates uniform airflow in the length direction and improves uniformity of the airflow in the plasma chamber 120.

In other embodiments, portions of the shunt holes 210 may also be aligned along one plasma electrode 110 toward another plasma electrode 110. Specifically, portions of the diverging apertures 210 may also be aligned along the width direction of the plasma chamber 120.

In one embodiment, the size of the diversion hole 210 is inversely related to the airflow rate at the position of the diversion hole 210. When the gas flow velocity is larger, the size of the splitter hole 210 at the position is reduced, so that the gas flow entering the plasma chamber 120 through the splitter hole 210 at the position is reduced; and when the gas flow rate is small, the size of the center flow hole 210 is increased to allow more gas flow to enter the plasma chamber 120 through the flow distribution hole 210. By reducing the size of the splitter holes 210 at locations where the gas flow rate is high and reducing the size of the splitter holes 210 at locations where the gas flow rate is low, the gas flow through each splitter hole 210 into the plasma chamber 120 is balanced.

Specifically, the airflow guiding structure 200 is divided into at least two different portions according to the airflow velocity at different positions corresponding to the airflow guiding structure 200, and the size of the diversion hole 210 on each portion corresponds to the average airflow velocity corresponding to the portion. For example, the airflow directing structure 200 is divided into three sections along its length, and the size of the splitter holes 210 in each section corresponds to the average airflow velocity corresponding to that section. By dividing the airflow directing structure 200 into different sections, the difficulty of machining the diverter holes 210 is facilitated to be reduced. As shown in fig. 3, at a position where the airflow velocity is high, the number of the corresponding diversion holes 210 is multiple, the multiple diversion holes 210 are arranged at intervals, the diversion holes 210 may be circular holes, and the diameter of a single diversion hole 210 is 1mm to 24.5 mm; at the position where the airflow velocity is high, the number of the diversion holes 210 may be one, two, or the like, and the diversion holes 210 may be strip-shaped holes, and different diversion holes 210 are arranged at intervals along the length direction thereof, wherein the length of a single diversion hole 210 may be 10mm to 1320.8mm, and the width of a single diversion hole 210 may be 1mm to 24.5 mm. Of course, in other embodiments, the size of the diversion holes 210 may also be set according to the gas flow rate and the size between the plasma electrodes 110.

In other embodiments, the airflow guiding structure 200 may not be divided into regions, and the sizes of the diversion holes 210 at different positions are directly related to the airflow velocity at the corresponding positions. In this embodiment, the distance between the diversion holes 210 may be uniform. In other embodiments, the spacing between the diverter holes 210 may also be non-uniform.

In another embodiment, the distribution density of the distribution holes 210 on the airflow guiding structure 200 is inversely related to the airflow velocity at the positions of the distribution holes 210. When the gas flow rate is large, the distribution density of the distribution holes 210 is reduced so as to reduce the amount of gas flow that enters the plasma chamber 120 through the distribution holes 210. When the flow velocity of the gas flow is small, the distribution density of the splitter holes 210 is increased, so that the amount of the gas flow entering the plasma chamber 120 through the splitter holes 210 is increased, and the purpose of homogenizing the gas flow in the plasma chamber 120 is achieved. In this embodiment, the size of each diverter hole 210 may be uniform. In other embodiments, the size of each diverter hole 210 may also be non-uniform.

In one embodiment, the surface of the airflow directing structure 200 facing the air intake assembly 300 is a smooth plane. Since the air intake assembly 300 injects air onto the air flow guiding structure 200, the surface of the air flow guiding structure 200 facing the air intake assembly 300 is set to be a smooth plane, so that the interference of the surface of the air flow guiding structure 200 facing the air intake assembly 300 on the air flow is avoided.

Optionally, the airflow directing structure 200 faces a smooth arc surface of the air intake assembly 300. Alternatively, the surface of the airflow guiding structure 200 facing the air intake assembly 300 may also be a smooth curved surface, and the smooth curved surface is concave towards the direction of the diversion hole 210, so as to guide the airflow to enter the diversion hole 210.

In the present embodiment, the airflow guiding structure 200 is a metal member. For example, the airflow directing structure 200 may be an aluminum alloy piece. In other embodiments, the airflow directing structure 200 may also be an injection molded piece or other structural member.

Referring to fig. 1 and 2, in an embodiment, the plasma apparatus 10 further includes a material placing frame 400, the material placing frame 400 is disposed in the plasma chamber 120 and spaced apart from the plasma electrode 110, and a material placing slot 410 is formed in the material placing frame 400. When in use, the workpiece to be processed can be disposed in the material placing slot 410, so as to realize the stable disposition of the workpiece to be processed in the plasma chamber 120.

In this embodiment, the material placing frame 400 is open to the side of the plasma electrode 110, so that the gas flow between the material placing frame 400 and the plasma electrode is distributed on the workpiece to be processed.

Specifically, the material placing slot 410 penetrates through the material placing frame 400 to form a communication opening towards one side of the air inlet 130, and the airflow guiding structure 200 is disposed on the communication opening of the material placing frame 400 and covers the communication opening, so that the diversion hole 210 is communicated with the material placing slot 410. By arranging the airflow guiding structure 200 on the material placing frame 400, the material placing frame 400 can provide support for the airflow guiding structure 200, and airflow can enter the material placing slot 410 through the shunting hole 210 and the communication port, so that the airflow is distributed on a workpiece to be processed.

In this embodiment, the size of the communication opening is larger than the size of the diversion hole 210. Because the airflow enters the plasma chamber 120 through the communication opening from the diversion hole 210, the communication opening is prevented from influencing the airflow guiding effect of the diversion hole 210 by being larger than the diversion hole 210.

The material placing frame 400 of the conventional plasma device 10 is not provided with a communication port, nor is the gas flow guiding structure 200 provided, so that the gas flow can only enter the plasma chamber 120 through the gap between the material placing frame 400 and the plasma electrode 110, and further when the gas flow passes through the gas inlet 130 of the plasma chamber 120, the gas flow can encounter the blockage of the side edge of the material placing frame 400, which not only affects the uniformity of the gas flow, but also causes the low efficiency of the gas flow entering the plasma chamber 120. Through setting up above-mentioned air current guide structure 200 for in the air current can get into plasma chamber 120 through diffluence hole 210, improve the efficiency that the air current got into plasma chamber 120, utilize the reposition of redundant personnel effect of diffluence hole 210 simultaneously, improve the homogeneity of air current, so that produce even plasma gas, increase the plasma treatment homogeneity of pending work piece, improve the treatment effeciency.

Referring to fig. 2, 5 and 6, in the present embodiment, the airflow guiding structure 200 is a strip-shaped structure, mounting portions 220 are formed at two ends of the strip-shaped airflow guiding structure 200, the mounting portions 220 are mounted on the material placing frame 400, the diversion hole 210 is located between the two mounting portions 220, and the communication port is located between the two mounting portions 220. Specifically, mounting hole 222 is opened on mounting portion 220, and the mating holes are opened on material placing frame 400, and mounting hole 222 can communicate with the mating holes. The connection screws are inserted into the mounting holes 222 and the matching holes, so that the airflow guiding structure 200 is mounted on the material placing frame 400.

In other embodiments, the airflow guiding structure 200 may be integrally formed on the material placing frame 400.

Referring to fig. 1 and 2, in an embodiment, the plasma apparatus 10 further includes a plasma chamber 500, the plasma electrode 110 is disposed in the plasma chamber 500, the gas inlet 130 is formed on a top wall of the plasma chamber 120, and the gas inlet assembly 300 is disposed on the top wall of the plasma chamber 500. The plasma chamber 500 is provided to accommodate the plasma electrode 110 and the gas flow guiding structure 200, and to facilitate the installation of the gas inlet assembly 300, thereby providing a stable environment for processing the workpiece to be processed.

In the present embodiment, there are a plurality of plasma generating assemblies 100, a plurality of plasma generating assemblies 100 are arranged in parallel and spaced apart, and each plasma generating assembly 100 is correspondingly provided with an airflow guiding structure 200.

Referring to fig. 2, 5 and 6, specifically, an abutting portion 230 is formed at an end of one mounting portion 220 of the airflow guiding structure 200, which is opposite to the other mounting portion 220, and the abutting portion 230 can abut against an inner wall of the plasma chamber 500, so as to limit a position of the airflow guiding structure 200 in the plasma chamber 500 and ensure stability of guiding the airflow. Further, an engaging portion may be formed on an inner wall of the plasma chamber 500, and the abutting portion 230 may be engaged with the engaging portion in a limited manner. In other embodiments, the abutment 230 may also be omitted.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.