阅读说明：本技术 用于光伏电池镀膜的立式pecvd设备 (Vertical PECVD equipment for coating film on photovoltaic cell ) 是由 李晔纯 成秋云 罗志敏 张弥涛 于 2019-10-31 设计创作，主要内容包括：本发明公开了一种用于光伏电池镀膜的立式PECVD设备,包括六轴插取片机器人和硅片过渡传输导轨,还包括三个立式镀膜反应柜,三个立式镀膜反应柜围成C形区域,硅片过渡传输导轨设于C形区域的开口处,六轴插取片机器人设于C形区域内。该用于光伏电池镀膜的立式PECVD设备布局合理、集约程度高、生产效率高以及生产成本低。(The invention discloses vertical PECVD equipment for coating a photovoltaic cell, which comprises a six-axis film inserting and taking robot, a silicon wafer transition transmission guide rail and three vertical film coating reaction cabinets, wherein the three vertical film coating reaction cabinets enclose a C-shaped area, the silicon wafer transition transmission guide rail is arranged at an opening of the C-shaped area, and the six-axis film inserting and taking robot is arranged in the C-shaped area. The vertical PECVD equipment for coating the photovoltaic cell is reasonable in layout, high in intensive degree, high in production efficiency and low in production cost.)

1. The utility model provides a vertical PECVD equipment for photovoltaic cell coating film, includes six inserts and gets piece robot (1) and silicon chip transition transmission guide rail (2), its characterized in that: the silicon wafer transition transmission device is characterized by further comprising three vertical film coating reaction cabinets (3), wherein a C-shaped area is defined by the three vertical film coating reaction cabinets (3), the silicon wafer transition transmission guide rail (2) is arranged at an opening of the C-shaped area, and the six-axis film inserting and taking robot (1) is arranged in the C-shaped area.

2. The vertical PECVD equipment for coating the photovoltaic cell as claimed in claim 1, wherein: the vertical coating reaction cabinet (3) is internally provided with a coating reaction chamber (31), a vacuum thermal reaction chamber (32) and a graphite boat lifting mechanism (33) are arranged in the coating reaction chamber (31), the graphite boat lifting mechanism (33) is provided with a graphite boat (4) which is vertically arranged, and the top of the vacuum thermal reaction chamber (32) is provided with an inlet and an outlet (321) for the graphite boat (4) to come in and go out.

3. The vertical PECVD equipment for coating the photovoltaic cell as claimed in claim 2, wherein: the graphite boat (4) comprises a plurality of layers of graphite sheets (41) arranged at intervals, and a silicon wafer supporting part (42) which protrudes upwards and is used for supporting a silicon wafer (8) is arranged on each graphite sheet (41).

4. The vertical PECVD equipment for coating the photovoltaic cell as claimed in claim 3, wherein: the movable end of the six-axis inserting and taking robot (1) is provided with a plurality of layers of inserting and taking plates (11) which are arranged at intervals, each inserting and taking plate (11) is provided with a vacuum chuck (12), and the distance between every two adjacent inserting and taking plates (11) is the same as the distance between every two adjacent graphite sheets (41).

5. The vertical PECVD equipment for coating the photovoltaic cell as claimed in claim 2, wherein: the graphite boat lifting mechanism (33) comprises a vertical movement module (331), a graphite boat loading component (332) and a sealing furnace door (333) used for sealing the entrance (321), the top end of the graphite boat loading component (332) is arranged on the vertical movement module (331), the sealing furnace door (333) is arranged at the top of the graphite boat loading component (332), and the graphite boat (4) is loaded in the graphite boat loading component (332).

6. The vertical PECVD equipment for coating the photovoltaic cell as claimed in claim 5, wherein: the vertical motion module (331) comprises a lead screw (3311), a vertical lifting frame (3312) and a servo motor (3313), the vertical lifting frame (3312) is slidably arranged in the coating reaction chamber (31), the lead screw (3311) is arranged in the coating reaction chamber (31), one end of the lead screw (3311) is connected with the servo motor (3313), the other end of the lead screw is in threaded connection with the vertical lifting frame (3312), and the graphite boat loading component (332) is hung at the top of the vertical lifting frame (3312).

7. The vertical PECVD apparatus for coating photovoltaic cells as claimed in any one of claims 1 to 6, wherein: the device also comprises a vacuumizing mechanism (5), wherein the vacuumizing mechanism (5) is connected with each vertical film coating reaction cabinet (3).

8. The vertical PECVD equipment for coating the photovoltaic cell as claimed in claim 7, wherein: the vacuum mechanism (5) comprises an evacuation vacuum pump (51) and three pressure control vacuum pumps (52), the evacuation vacuum pump (51) is connected with each vertical coating reaction cabinet (3), and the three pressure control vacuum pumps (52) are correspondingly connected with the three vertical coating reaction cabinets (3) one by one.

9. The vertical PECVD apparatus for coating photovoltaic cells as claimed in any one of claims 1 to 6, wherein: the silicon wafer transition transmission guide rail (2) comprises a feeding guide rail (21) and a discharging guide rail (22) which are arranged side by side.

10. The vertical PECVD equipment for coating the photovoltaic cell as claimed in claim 9, wherein: the feeding guide rail (21) and the discharging guide rail (22) are both two.

Technical Field

The invention relates to the technical field of photovoltaic cell coating equipment, in particular to vertical PECVD equipment for coating a photovoltaic cell.

Background

At present, a horizontal PECVD device is generally adopted for preparing the antireflection film of the photovoltaic cell, and the horizontal PECVD device comprises a purification table, a waste gas chamber, a furnace body cabinet, an air source vacuum cabinet and the like. The purification platform is provided with a boat pushing system, an automatic loading and unloading system and other mechanisms, the boat pushing system corresponds to the reaction tube and sends the graphite boat into the reaction tube, and the automatic loading and unloading system realizes the transportation of the graphite boat between the buffer storage rack and the boat pushing system; the waste gas chamber comprises a furnace door mechanism and a waste gas collecting and discharging device, the furnace door mechanism realizes the vacuum sealing of the furnace door to the process pipe, and the waste gas collecting and discharging device can discharge residual gas and hot gas after reaction in the process pipe into the equipment in time after the furnace door is opened; the furnace body cabinet is internally provided with 5 reaction chambers from bottom to top, and each reaction chamber is a vacuum thermal reaction container consisting of a heating furnace body, a quartz tube and a group of sealing flanges and is used for depositing an antireflection film on a silicon wafer; the gas source vacuum cabinet is provided with a process gas system, a vacuum system, a radio frequency power supply cabinet and the like, each reaction tube is provided with an independent gas conveying system and a vacuum system, gas is fed from the front end of the process tube, the vacuum system comprises a dry vacuum pump, an air exhaust pipeline, a vacuum butterfly valve for adjusting the pressure in the tube and the like, and the radio frequency power supply is a part for providing electric energy for forming plasma in the reaction tube. The horizontal PECVD equipment is unreasonable in layout and low in concentration degree, so that the production efficiency is low and the production cost is high. Moreover, the slide glass tool of the horizontal PECVD equipment is a horizontal graphite boat, the graphite boat 4 is formed by assembling a plurality of graphite sheets, a vertical insert sheet mode is adopted, the graphite sheets are provided with three clamping points for fixing the silicon wafers, an insert sheet robot in an automatic insert sheet machine inserts the silicon wafers into the graphite boat from the upper end of the graphite boat by attaching the graphite sheets, and the silicon wafers are easily scratched by the horizontal PECVD mode of attaching the graphite sheets closely; during the reaction, the silicon chip can not be coated with a film at the position of the clamping point, and the clamping point print is formed; meanwhile, when the silicon wafer is vertically inserted into the clamping point of the graphite boat, the silicon wafer is easy to break if the position is inaccurate.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide vertical PECVD equipment for coating the photovoltaic cell, which has the advantages of reasonable layout, high integration degree, high production efficiency and low production cost.

In order to solve the technical problems, the invention adopts the following technical scheme:

the utility model provides a vertical PECVD equipment for photovoltaic cell coating film, includes six inserts a robot and silicon chip transition transmission guide rail, still includes three vertical coating film reaction cabinet, and is three vertical coating film reaction cabinet encloses into C shape region, silicon chip transition transmission guide rail locates the regional opening part of C shape, six insert a robot and locate in the C shape region.

As a further improvement of the above technical solution:

the vertical coating reaction cabinet is internally provided with a coating reaction chamber, the coating reaction chamber is internally provided with a vacuum thermal reaction chamber and a graphite boat lifting mechanism, the graphite boat lifting mechanism is provided with a vertically arranged graphite boat, and the top of the vacuum thermal reaction chamber is provided with an inlet and an outlet for the graphite boat to enter and exit.

The graphite boat comprises a plurality of layers of graphite sheets arranged at intervals, and the graphite sheets are provided with upwards-protruding silicon wafer supporting parts for supporting silicon wafers.

The movable end of the six-axis inserting and taking robot is provided with a plurality of layers of inserting and taking plates which are arranged at intervals, each inserting and taking plate is provided with a vacuum chuck, and the distance between every two adjacent inserting and taking plates is the same as the distance between every two adjacent graphite sheets.

The graphite boat lifting mechanism comprises a vertical movement module, a graphite boat loading assembly and a sealed furnace door for sealing an entrance, the top end of the graphite boat loading assembly is arranged on the vertical movement module, the sealed furnace door is arranged at the top of the graphite boat loading assembly, and the graphite boat is loaded in the graphite boat loading assembly.

The vertical motion module comprises a screw rod, a vertical lifting frame and a servo motor, the vertical lifting frame is slidably arranged in the coating reaction chamber, the screw rod is arranged in the coating reaction chamber, one end of the screw rod is connected with the servo motor, the other end of the screw rod is in threaded connection with the vertical lifting frame, and the graphite boat loading assembly is hung at the top of the vertical lifting frame.

The device also comprises a vacuumizing mechanism, and the vacuumizing mechanism is connected with each vertical coating reaction cabinet.

The vacuum mechanism comprises a vacuum pump and three pressure control vacuum pumps, the vacuum pump is connected with each vertical coating reaction cabinet, and the three pressure control vacuum pumps are connected with the three vertical coating reaction cabinets in a one-to-one correspondence manner.

The silicon wafer transition transmission guide rail comprises a feeding guide rail and a discharging guide rail which are arranged side by side.

The feeding guide rail and the discharging guide rail are both two.

Compared with the prior art, the invention has the advantages that:

the vertical PECVD equipment for coating the photovoltaic cell comprises a six-axis film inserting and taking robot, a silicon wafer transition transmission guide rail and three vertical film coating reaction cabinets, wherein a C-shaped area is surrounded by the three vertical film coating reaction cabinets, the silicon wafer transition transmission guide rail is arranged at an opening of the C-shaped area, and the six-axis film inserting and taking robot is arranged in the C-shaped area. The vertical PECVD equipment for photovoltaic cell film coating is reasonable in layout and high in intensive degree, can be alternately served by three vertical film coating reaction cabinets through one six-axis film inserting and taking robot, increases the utilization rate of the six-axis film inserting and taking robot, improves the production efficiency and reduces the production cost.

Furthermore, because the graphite boat is vertically arranged, the silicon wafer can adopt a horizontally placed inserting piece to replace a vertical clamping groove inserting piece of a horizontal PECVD device, which is beneficial to reducing the breakage rate of the silicon wafer, eliminating the clamping point printing which is necessarily generated during the film coating of the horizontal PECVD device, reducing the plating winding phenomenon on the back of the silicon wafer and reducing the scratch defect on an antireflection film of the silicon wafer, and provides a powerful guarantee for realizing the sheet production and reducing the manufacturing cost of a battery.

Drawings

FIG. 1 is a schematic top view of a vertical PECVD apparatus for coating a photovoltaic cell.

FIG. 2 is a schematic structural diagram of a vertical PECVD apparatus for coating a photovoltaic cell.

FIG. 3 is a schematic side view of a vertical PECVD apparatus for coating a photovoltaic cell according to the present invention.

FIG. 4 is a schematic front view of the vertical coating reaction cabinet of the present invention.

FIG. 5 is a schematic side view of the vertical coating reaction chamber of the present invention.

FIG. 6 is a schematic top view of the vertical coating reaction chamber of the present invention.

FIG. 7 is a schematic view of the structure of the graphite boat of the present invention.

FIG. 8 is a schematic illustration of the insert of the graphite boat of the present invention.

FIG. 9 is a schematic view of the combination of the graphite boat and the silicon wafer of the present invention.

Fig. 10 is a schematic perspective view of the insertion plate of the present invention.

Fig. 11 is a schematic perspective view of a first management and control cabinet according to the present invention.

Fig. 12 is a schematic perspective view of a second management and control cabinet according to the present invention.

Fig. 13 is a schematic perspective view of a power distribution cabinet according to the present invention.

The reference numerals in the figures denote:

1. a six-axis film inserting and taking robot; 11. inserting and taking the plate; 12. a vacuum chuck; 2. a silicon wafer transition transmission guide rail; 21. a feeding guide rail; 22. blanking guide rails; 3. a vertical film coating reaction cabinet; 31. a film coating reaction chamber; 32. a vacuum thermal reaction chamber; 321. an entrance and an exit; 33. a graphite boat lifting mechanism; 331. a vertical motion module; 3311. a screw rod; 3312. a vertical lifting frame; 3313. a servo motor; 332. a graphite boat loading assembly; 333. sealing the oven door; 4. a graphite boat; 41. a graphite sheet; 42. a silicon wafer supporting part; 43. a gap; 5. a vacuum mechanism; 51. evacuating the vacuum pump; 52. a pressure-controlled vacuum pump; 6. a control cabinet; 61. a cooling water circulation module; 62. an air source control module; 63. a PLC control module; 64. a radio frequency power supply module; 7. a power distribution cabinet; 8. and (3) a silicon wafer.

Detailed Description

The invention will be described in further detail below with reference to the drawings and specific examples.

Fig. 1 to 13 show an embodiment of the vertical PECVD apparatus for photovoltaic cell coating, the vertical PECVD apparatus for photovoltaic cell coating includes a six-axis inserting and taking robot 1, a silicon wafer transition transmission guide rail 2, and three vertical coating reaction cabinets 3, the three vertical coating reaction cabinets 3 enclose a C-shaped area, the silicon wafer transition transmission guide rail 2 is arranged at an opening of the C-shaped area, and the six-axis inserting and taking robot 1 is arranged in the C-shaped area. The silicon wafer transition transmission guide rail 2 is used for transmitting the silicon wafer 8, namely the silicon wafer 8 which is not coated with a film can be transmitted to the six-axis inserting and taking robot 1, and the coated silicon wafer 8 can be transmitted out, namely the silicon wafer transition transmission guide rail 2 is a feeding and discharging channel of vertical PECVD equipment, firstly, the silicon wafer 8 to be coated is taken out from a basket (not shown in the figure) and is transported to the six-axis inserting and taking robot 1, and secondly, the silicon wafer 8 which is coated with a film is transported to the basket so as to be subjected to next process. The six-axis inserting and taking robot 1 is used for taking and placing the silicon wafer 8, is mainly connected with a feeding and discharging transmission line (a silicon wafer transition transmission guide rail 2) and a graphite boat 4, can absorb and convey the silicon wafer 8 which is not coated on the silicon wafer transition transmission guide rail 2 to the vertical coating reaction cabinet 3, can absorb and convey the coated silicon wafer 8 in the vertical coating reaction cabinet 3 to the silicon wafer transition transmission guide rail 2, and the vertical coating reaction cabinet 3 is used for coating the silicon wafer 8. This a vertical PECVD equipment for photovoltaic cell coating film is rationally distributed, intensive degree is high, can insert through a six axis and get piece robot 1 and serve for three vertical coating film reaction cabinet 3 in turn, has increased the utilization ratio that six axis inserted and get piece robot 1, has improved production efficiency, has reduced manufacturing cost.

In this embodiment, as shown in fig. 4 and 5, a coating reaction chamber 31 is installed in the vertical coating reaction cabinet 3, a vacuum thermal reaction chamber 32 and a graphite boat lifting mechanism 33 are installed in the coating reaction chamber 31, a graphite boat 4 vertically installed is installed on the graphite boat lifting mechanism 33, and an entrance 321 for the graphite boat 4 to enter and exit is installed at the top of the vacuum thermal reaction chamber 32. In the structure, the vertical film coating reaction cabinet 3 is vertically fixed, and the graphite boat lifting mechanism 33 can drive the graphite boat 4 to be vertically inserted into the vacuum thermal reaction chamber 32 from the inlet 321 to the outlet, so that the silicon wafers 8 on the graphite boat 4 can be kept horizontal. Specifically, each vertical coating reaction cabinet 3 is provided with two coating reaction chambers 31, and six coating reaction chambers 31 are provided. As shown in fig. 7 to 9, the graphite boat 4 includes a plurality of graphite sheets 41 arranged at intervals, the graphite sheets 41 are horizontally arranged, the graphite sheets 41 are provided with silicon wafer supporting portions 42 protruding upward for supporting the silicon wafers 8, (in another embodiment, the silicon wafer supporting portions 42 can be arranged on the graphite sheets 41 with adjustable height, the winding plating can be adjusted by adjusting the height of the silicon wafer supporting portions 42 to control the size of the gaps 43 between the graphite sheets 41 and the silicon wafers 8, the winding plating refers to a thin film formed on the back of the silicon wafers 8 after the gas enters the gaps 43 on the back of the silicon wafers 8, the width of the gaps is small, the winding plating degree is different, and the winding plating degree requirements of different products are different), as shown in fig. 10, six-axis inserting and takingThe movable end of the robot 1 is provided with a plurality of layers of insertion plates 11 arranged at intervals, the distance between adjacent insertion plates 11 is the same as the distance between adjacent graphite sheets 41, each insertion plate 11 is provided with a vacuum chuck 12, preferably ten layers of insertion plates 11, each insertion plate 11 is provided with four vacuum chucks 12, namely each layer of insertion plate 11 can absorb two 156 × 156 (mm) insertion plates 11²) The silicon wafer 8 can adsorb 20 silicon wafers 8 in total, and the vacuum chuck 12 adsorbs the silicon wafer 8 by adopting the Bernoulli vacuum principle. When transferring silicon wafers 8 to graphite sheets 41, insertion plates 11 are inserted between respective graphite sheets 41 so that insertion plates 11 and graphite sheets 41 are arranged to be staggered in the vertical direction so that silicon wafers 8 are horizontally inserted into graphite boat 4 and then horizontally placed on graphite sheets 41. It should be noted that the wafer support 42 may be configured to be height adjustable.

In this embodiment, a design mode of vertical fixing of the reaction chamber and horizontal insertion of the silicon wafer 8 is adopted. The single device mainly comprises a 6-tube film coating reaction chamber 31 and a six-axis film inserting and taking robot 1, the film loading amount reaches 450 pieces/tube, and the productivity is 4000 pieces/hour; the six-axis inserting and taking robot 1 can complete automatic inserting and taking of the sheets between the feeding and discharging transmission line and the graphite boat 4, and the automation degree is improved; the silicon wafer 8 adopts the horizontally placed insert to replace a vertical clamping groove insert of a horizontal PECVD device, which is beneficial to reducing the breakage rate of the silicon wafer 8, eliminating the clamping point print which is necessarily generated during the film coating of the horizontal PECVD, reducing the plating winding phenomenon on the back of the silicon wafer 8 and reducing the scratch defect on an antireflection film of the silicon wafer 8, and provides powerful guarantee for realizing the flake production and reducing the manufacturing cost of a battery.

In this embodiment, as shown in fig. 4 and 5, the graphite boat lifting mechanism 33 includes a vertical movement module 331, a graphite boat loading assembly 332, and a sealing door 333 for sealing the entrance 321, wherein the top end of the graphite boat loading assembly 332 is disposed on the vertical movement module 331, the sealing door 333 is disposed on the top of the graphite boat loading assembly 332, and the graphite boat 4 is loaded in the graphite boat loading assembly 332. Specifically, the vertical motion module 331 includes a screw rod 3311, a vertical lift 3312 and a servo motor 3313, the vertical lift 3312 is slidably disposed in the coating reaction chamber 31, the screw rod 3311 is disposed in the coating reaction chamber 31, and has one end connected to the servo motor 3313 and the other end connected to the vertical lift 3312 by a screw, and the graphite boat loading assembly 332 is suspended on the top of the vertical lift 3312. Further, the lead screw 3311 is a ball screw, a linear slide rail is arranged in the coating reaction chamber 31, the vertical lifting rack 3312 is slidably arranged on the linear slide rail, and the vertical movement is realized by driving the ball screw by the servo motor 3313 to push the vertical lifting rack 3312 to move up and down along the slide rail; the sealing furnace door 333 is hung on the vertical lifting frame 3312 through a vacuum corrugated pipe, so that the sealing furnace door 333 is self-adaptively attached to the water-cooling flange at the inlet 321 of the vacuum thermal reaction chamber 32 during sealing. During the process of inserting the graphite boat 4, the graphite boat 4 is firstly positioned above the vacuum thermal reaction chamber 32, the servo motor 3313 drives the screw rod 3311 to rotate, the screw thread of the screw rod 3311 drives the vertical lifting rack 3312 to descend until the graphite boat loading assembly 332 and the graphite boat 4 are inserted into the vacuum thermal reaction chamber 32 through the access 321, and the sealing furnace door 333 just blocks the access 321; otherwise, the graphite boat 4 is taken out, and the operation is convenient.

In this embodiment, as shown in fig. 1, the apparatus further includes a vacuum pumping mechanism 5, and the vacuum pumping mechanism 5 is connected to each vertical film coating reaction cabinet 3. Specifically, the vacuum pumping mechanism 5 includes an evacuation vacuum pump 51 and three pressure control vacuum pumps 52, the evacuation vacuum pump 51 is connected to each vertical coating reaction cabinet 3, and is configured to pump the interior of the vacuum thermal reaction chamber 32 in each vertical coating reaction cabinet 3 to a vacuum state, and the three pressure control vacuum pumps 52 are connected to the three vertical coating reaction cabinets 3 in a one-to-one correspondence manner, that is, each pressure control vacuum pump 52 controls the air pressure in the vacuum thermal reaction chamber 32 of one vertical coating reaction cabinet 3, so that the air pressure in the vacuum thermal reaction chamber 32 is within a range value favorable for coating. The four vacuum pumps are used, so that the full-load production of the six-tube process can be met, and the cost investment of the two vacuum pumps can be reduced.

In this embodiment, as shown in fig. 1, the silicon wafer transition transmission guide rails 2 include four feeding guide rails 21 and four discharging guide rails 22 arranged side by side, specifically, the two (or more) feeding guide rails 21 and the two or more discharging guide rails 22 are both provided, during feeding, when one feeding guide rail 21 is performing feeding work, the other one is used as a buffer station to store the silicon wafer 8 to be taken out, and during discharging, when one discharging guide rail 22 is performing discharging work, the other one is used as a buffer station to empty the silicon wafer 8 to be taken out.

In this embodiment, as shown in fig. 11 and 12, the system further includes a control cabinet 6, a cooling water circulation module 61, an air source control module 62, a PLC control module 63, and a radio frequency power supply module 64 are disposed in the control cabinet 6, and each module is correspondingly connected to each vertical coating reaction cabinet 3, wherein the air source control module 62 includes a corrosion-resistant stainless steel pipe, a diaphragm valve, a check valve, a mass flow meter, and the like, so as to control the process reaction gas, nitrogen, and compressed air; the radio frequency power supply module 64 comprises a radio frequency power supply cabinet, wherein a radio frequency power supply is arranged in the radio frequency power supply cabinet and provides plasma enhanced electric energy for the process reaction; the cooling water circulation module 61 provides cooling water for the whole equipment to ensure the normal operation of components needing cooling, such as the reaction chamber, the radio frequency power supply, the vacuum pump and the like; the PLC control module 63 is used to control the operation of each coating reaction chamber 31. Specifically, the number of the control cabinets 6 may be one, two, or more, in this embodiment, the number of the control cabinets 6 is two, one of the control cabinets is set as a first control cabinet as shown in fig. 11, and the other control cabinet is set as a second control cabinet as shown in fig. 12, two sets of cooling water circulation modules 61, air source control modules 62, PLC control modules 63, and radio frequency power supply modules 64 are arranged in the first control cabinet, and respectively control the operation of the four coating reaction chambers 31, and only one set of cooling water circulation module 61, air source control module 62, PLC control module 63, and radio frequency power supply module 64 is arranged in the second control cabinet, and is used for controlling the operation of the two coating reaction chambers 31.

In this embodiment, as shown in fig. 13, still include switch board 7, switch board 7 mainly places all kinds of control components and parts such as binding post row, distribution switch, temperature control instrument etc. for equipment provides the electric energy supply, control equipment's heating power etc..

Although the invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make numerous possible variations and modifications to the inventive arrangements, or modify equivalent embodiments, using the teachings disclosed above, without departing from the scope of the inventive arrangements. Therefore, any simple modification, equivalent change and modification of the above embodiments according to the technical spirit of the invention should fall within the protection scope of the technical scheme of the invention.