Positioning device for chip cutting processing

Abstract

The invention relates to a positioning device for chip cutting processing, and belongs to the technical field of semiconductor chip processing. The positioning device for chip cutting processing comprises a vacuum base, a porous ceramic plate is embedded in the top of the vacuum base, the surface of the vacuum base is fixedly connected and communicated with an air pipe, one end of the air pipe is fixedly connected and communicated with a vacuum pump, and the bottom of the vacuum base is fixedly connected with a cooling mechanism; the cooling mechanism comprises a hollowed-out mounting seat, a grating pipe and a water pump, the hollowed-out mounting seat is fixedly connected to the bottom of the vacuum base, and the horizontal section of the hollowed-out mounting seat is in an L shape; the cooling mechanism directly guides the cooling liquid to the interface key area of the wafer and the blue film through the precise communication structure of the grating pipe and the vertical pipe in the cooling mechanism, targeted efficient heat dissipation is achieved, and the problems of cutting heat accumulation, wafer heat damage and adhesive film softening caused by unsmooth interface heat dissipation are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor chip processing technology, and in particular to a positioning device for chip cutting processing. Background Technology

[0002] Current mainstream wafer dicing processes use a framework system consisting of a rigid outer ring and a flexible blue film to support the wafer. During dicing, the tray is transferred to a precision ceramic vacuum chuck, which holds the wafer in place by adsorption through the blue film. Subsequently, dicing is performed by a diamond blade or laser under water-cooled conditions.

[0003] While water spray cooling during dicing can reduce the front-side temperature, it cannot solve the heat dissipation problem at the blue film interface: the cooling water cannot reach the interface between the wafer and the blue film, and the poor thermal conductivity of the blue film severely hinders the downward conduction of heat, resulting in heat accumulation during dicing, causing thermal damage to the wafer and softening of the film, which directly affects the dicing yield. Summary of the Invention

[0004] Therefore, it is necessary to provide a positioning device for chip cutting and processing to address the thermal management problem caused by the inability of blue film insulation and water spray cooling to solve interface heat dissipation during wafer cutting, which leads to thermal damage and reduced yield.

[0005] A positioning device for chip cutting and processing includes a vacuum base, a porous ceramic disk is embedded in the top of the vacuum base, an air pipe is fixedly connected and communicated with the surface of the vacuum base, one end of the air pipe is fixedly connected and communicated with a vacuum pump, and a cooling mechanism is fixedly connected to the bottom of the vacuum base.

[0006] In one embodiment, the cooling mechanism includes a perforated mounting base, a grid tube, and a water pump. The perforated mounting base is fixedly connected to the bottom of the vacuum base, and the horizontal cross-sectional shape of the perforated mounting base is L-shaped. The grid tube is fixedly connected to the inside of the porous ceramic disc, and the opening of the grid tube passes through the porous ceramic disc and the vacuum base in sequence and extends to the outside of the vacuum base. The lower surface of the grid tube is fixedly connected to and communicates with a vertical pipe. The bottom of the vertical pipe passes through the porous ceramic disc, the vacuum base, and the perforated mounting base in sequence and is flush with the inner top wall of the perforated mounting base. The outlet end of the water pump is fixedly connected to a high-pressure resistant water pipe, and the centerline of the outlet end of the high-pressure resistant water pipe coincides with the centerline of the adjacent vertical pipe on the same vertical line.

[0007] In one embodiment, the outlet end of the high-pressure water pipe is fixedly connected to a liquid guide bucket, the top of the liquid guide bucket is in contact with the inner top wall of the hollow mounting base, and the ratio of the inner diameter of the opening of the liquid guide bucket to the length of the distance between two adjacent vertical pipes is 5 to 2.

[0008] In one embodiment, the vertical cross-sectional shape of the inner side of the liquid guiding funnel is conical, and the inner diameter of the liquid guiding funnel gradually increases from bottom to top.

[0009] In one embodiment, the high-pressure resistant water pipe is made of stainless steel and has a length of 1.5 meters.

[0010] In one embodiment, a support column is fixedly connected to the bottom of the liquid guiding hopper, and there are two support columns, which are symmetrically distributed on both sides of the high-pressure water pipe.

[0011] In one embodiment, a ball bearing is embedded in the bottom of the support column, and the center point of the ball bearing is located inside the support column.

[0012] In one embodiment, the ball is made of tungsten carbide and has a diameter of ten millimeters.

[0013] In one embodiment, the inlet end of the water pump is detachably connected to a filter element, and the inlet end of the filter element is detachably connected to a water inlet pipe.

[0014] In one embodiment, the filter element is a cartridge filter, and the interior of the filter element is filled with an activated carbon filter element.

[0015] In one embodiment, a water-blocking ring is fixedly connected to the surface of the vacuum base, the vertical cross-sectional shape of the inner side of the water-blocking ring is an isosceles trapezoid, and the opening of the grid tube is located inside the water-blocking ring.

[0016] 1. The above-mentioned positioning device for chip cutting and processing has a cooling mechanism that guides the coolant directly to the key interface area between the wafer and the blue film through the precise connection structure between its internal grid tube and vertical tube, achieving targeted and efficient heat dissipation, and effectively solving the problems of heat accumulation during cutting, wafer thermal damage and film softening caused by poor heat dissipation at the interface.

[0017] 2. Furthermore, by directly embedding the grid tube into the porous ceramic disk and forming an extremely short cooling channel with the vertical tube and the bottom liquid supply system, the transmission path and time of the coolant from the source to the wafer interface are greatly shortened. This solves the problems of cooling delay and uneven temperature and efficiency reduction when reaching the interface caused by the long cooling water path and complex process of traditional external spraying, and achieves fast and uniform interface heat dissipation.

[0018] 3. The filter element efficiently removes cutting debris and impurities from the coolant through its internal activated carbon filter element. Its detachable design simplifies maintenance and effectively solves the problems of easy blockage of coolant circulation pipes, accelerated system wear, and complicated and cumbersome subsequent maintenance. In addition, the water-blocking ring, with its isosceles trapezoidal cross-sectional structure, effectively restricts the flow path of the coolant, prevents liquid splashing during the cooling process, and solves the problems of low coolant utilization, pollution caused by splashing, and uneven interface cooling effect. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure and the cutting equipment in this invention.

[0021] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0022] Figure 3 This is a schematic diagram of a partial structure in this invention;

[0023] Figure 4 This is a cross-sectional schematic diagram of a partial structure in this invention;

[0024] Figure 5 for Figure 4 Enlarged view of point A in the middle;

[0025] Figure 6 This is a schematic diagram showing the arrangement of the grid tubes and vertical tubes in this invention;

[0026] Figure 7 This is a partial explosion diagram of the cooling mechanism in this invention.

[0027] Figure label:

[0028] 100. Vacuum base; 200. Porous ceramic disc; 300. Gas pipe; 400. Vacuum pump; 500. Cooling mechanism; 510. Hollow mounting base; 520. Grille pipe; 530. Water pump; 540. Vertical pipe; 550. High-pressure resistant water pipe; 560. Liquid guide hopper; 570. Support column; 580. Ball bearing; 590. Filter element; 5100. Water inlet pipe; 5110. Water baffle ring. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this specification are for illustrative purposes only and do not represent the only possible implementation.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0034] The following is combined Figure 1 - Figure 7 The present invention describes a positioning device for chip cutting and processing.

[0035] In one embodiment, a positioning device for chip cutting and processing includes a vacuum base 100, a porous ceramic disk 200 is embedded in the top of the vacuum base 100, an air pipe 300 is fixedly connected and communicated to the surface of the vacuum base 100, one end of the air pipe 300 is fixedly connected and communicated to a vacuum pump 400, and a cooling mechanism 500 is fixedly connected to the bottom of the vacuum base 100.

[0036] As per the instruction manual Figure 1As shown, this positioning device needs to be used with cutting equipment. The instruction manual is attached. Figure 1 To effectively demonstrate the assembly effect of the positioning device, the cutting equipment here is shown with its outer casing removed. The actual model of this cutting equipment is the SYJ-800 CNC dicing cutter. Its core framework consists of a computer control system, a spindle cutting system, a precision motion system, and a cooling and protection system. The computer system acts as the brain, responsible for executing the Windows-based operating software to direct the operation of the entire machine. The spindle system uses a high-torque motor to drive the diamond saw blade for high-speed rotational cutting. The precision motion system provides slides along the X, Y, and Z axes, driven by high-precision stepper motors to ensure accurate positioning of the cutting path. Its worktable also has a 90-degree horizontal rotation function to adapt to cutting requirements at complex angles. In addition, the entire set of equipment is equipped with an external circulating coolant interface and a waterproof cover, forming a complete cooling and safety protection system.

[0037] The working principle of the SYJ-800 CNC dicing and cutting machine is as follows: Under the unified command of the computer control system, the precision motion system drives the entire worktable and the fixed sample, generating precise relative motion between them and the high-speed rotating spindle blade. After the operator pre-programs the cutting program, the control system automatically coordinates the linear movement of the X and Y axes with the rotational movement of the worktable, enabling the diamond saw blade to cut the sample according to the set path and depth. Throughout the cutting process, the cooling system continuously sprays coolant to reduce the high temperature generated by friction at the cutting point and to flush away cutting debris, thereby ensuring the quality of the cut surface and the processing accuracy.

[0038] When using the SYJ-800 CNC dicing and cutting machine, the first step is to complete the preparation work, including securely installing the equipment, connecting the power supply and cooling water pipes, and selecting a suitable diamond saw blade to install on the spindle. Next, proceed to the clamping and positioning stage: place the sample to be cut on the ceramic vacuum chuck on the worktable, start the vacuum pump 400 to firmly suction it, and then use the control system to precisely adjust the blade tip to the starting machining position. Next, execute the cutting: call or create the cutting program on the computer, set the spindle speed, cutting speed, and other parameters, and then start the equipment. The system will automatically complete the water cooling and all cutting operations. After cutting, the coolant and spindle must be turned off sequentially, the vacuum suction released, and the workpiece removed. Finally, perform necessary cleaning and maintenance on the equipment.

[0039] In the SYJ-800 CNC dicing and dicing machine, the positioning device for chip dicing is not an external accessory that users frequently disassemble and reassemble. Instead, it is a core component of the sample worktable, precisely integrated into the system before the machine leaves the factory. It is crucial that the outlet of the high-pressure water pipe 550 is positioned directly below the workpiece, with the outlet facing upwards. The inlet of the water pipe 5100 is then connected to the water collection tank integrated into the SYJ-800 CNC dicing and dicing machine. The installation essentially involves an internal vacuum pipeline connection: the vacuum base 100 is reliably connected to the vacuum pump 400 via the built-in air pipe 300. When the vacuum pump 400 starts, it extracts air from between the suction cup and the wafer covered with a blue film, creating negative pressure for strong adsorption. Therefore, the user's daily operation focuses on pre-use cleaning and checking the pore patency to ensure adsorption efficiency, while the overall physical installation and debugging of the suction cup are completed by the manufacturer before shipment.

[0040] like Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, the cooling mechanism 500 includes a perforated mounting base 510, a grid tube 520, and a water pump 530. The perforated mounting base 510 is fixedly connected to the bottom of the vacuum base 100. The horizontal cross-sectional shape of the perforated mounting base 510 is L-shaped. This design provides a stable support structure, ensuring the tight integration of the cooling mechanism 500 and the vacuum base 100, and enhancing the overall rigidity and durability of the system. The grid tube 520 is fixedly connected to the inside of the porous ceramic disc 200. The opening of the grid tube 520 passes through the porous ceramic disc 200 and the vacuum base 100 in sequence and extends to the outside of the vacuum base 100. The lower surface of the grid tube 520 is fixedly connected to and communicates with a vertical tube 540. The bottom of the vertical tube 540 passes through the porous ceramic disc 200, the vacuum base 100, and the perforated mounting base 510 in sequence and is flush with the inner top wall of the perforated mounting base 510. This interconnected structure ensures precise guidance of the coolant to the wafer-blue film interface, achieving point-to-point cooling of the dicing area. It dynamically responds to localized temperature rises, effectively preventing wafer thermal damage and film softening, thus significantly improving dicing yield. A high-pressure water pipe 550 is fixedly connected to the outlet of the water pump 530. The centerline of the outlet of the high-pressure water pipe 550 coincides with the centerline of the adjacent vertical pipe 540 on the same vertical line. The high-pressure water pipe 550 is made of stainless steel and is 1.5 meters long. The stainless steel material provides it with excellent high-pressure resistance and corrosion resistance, ensuring stable high-pressure delivery of coolant and a long service life within its 1.5-meter length.

[0041] The circulating water pump 530 is a Ptek brushless DC magnetic drive pump. Its main structure consists of a brushless motor, a magnetic coupler, and an impeller. Its working principle is to indirectly drive the impeller rotation via a magnetic field to pressurize the coolant, and its seal-free design fundamentally prevents coolant leakage. During system initialization, coolant is drawn from the inlet pipe 5100 through the pump's inlet end, and the pressurized coolant is pumped into the high-pressure resistant water pipe 550 through the outlet end. The pump's seal-free design ensures the reliability and safety of coolant circulation, fundamentally avoiding leakage risks and equipment contamination.

[0042] A guide hopper 560 is fixedly connected to the outlet end of the high-pressure water pipe 550. The top of the guide hopper 560 contacts the inner top wall of the hollow mounting base 510. The ratio of the inner diameter of the guide hopper 560 opening to the distance between two adjacent vertical pipes 540 is 5:2. This specific ratio optimizes the flow distribution of coolant and effectively reduces splashing and pressure loss. The vertical cross-section of the inner side of the guide hopper 560 is cone-shaped, and the inner diameter of the guide hopper 560 gradually increases from bottom to top. Its cone-shaped structure allows for smooth diffusion and concentrated injection of coolant, ensuring uniformity and accuracy of delivery to the vertical pipes 540. Two support columns 570 are fixedly connected to the bottom of the guide hopper 560, and the two support columns 570 are symmetrically distributed on both sides of the high-pressure water pipe 550. This symmetrical support structure effectively prevents the cooling mechanism 500 from shaking during the cutting process, ensuring the continuity and positional accuracy of the coolant delivery. A ball bearing 580 is embedded in the bottom of the support column 570, with its center point located inside the support column 570. The ball bearing 580 is made of tungsten carbide and has a diameter of ten millimeters. The high hardness and wear resistance of tungsten carbide, combined with its ten-millimeter diameter, significantly reduces frictional resistance, allowing the entire mechanism to smoothly follow the worktable's movement and extending the service life of critical components.

[0043] A filter element 590 is detachably connected to the inlet end of the water pump 530, and an inlet pipe 5100 is detachably connected to the inlet end of the filter element 590. The filter element 590 is a cartridge filter, and its interior is filled with an activated carbon filter element. The working principle of this cartridge filter is that when the coolant flows through its interior, the activated carbon filter element can physically intercept and adsorb cutting debris and impurities in the water. The method of use is to detachably connect the inlet end of the filter element 590 to the inlet pipe 5100, and replace or clean it regularly to ensure the cleanliness and smooth circulation of the coolant. This filtration system can efficiently maintain the cleanliness of the coolant, prevent pipe blockage and system wear, and the detachable design makes regular replacement and cleaning convenient, greatly reducing maintenance difficulty and resource consumption. A water-blocking ring 5110 is fixedly connected to the surface of the vacuum base 100. The vertical cross-sectional shape of the inner side of the water-blocking ring 5110 is an isosceles trapezoidal shape, and the opening of the grid pipe 520 is located inside the water-blocking ring 5110. Its isosceles trapezoidal cross-section effectively prevents coolant from splashing outwards, ensuring that the coolant concentrates on the critical interface between the wafer and the blue film.

[0044] The complete operation process of this positioning device is as follows:

[0045] System Start-up and Fixation: Before starting the SYJ-800 CNC dicing machine, place the wafer sample with the blue film attached onto the porous ceramic disk 200 and start the vacuum pump 400. The vacuum pump 400 extracts air from the vacuum base 100 through the air pipe 300, creating a negative pressure in the porous ceramic disk 200, which firmly adsorbs the blue film on the wafer, ensuring stability during the dicing process.

[0046] Coolant circulation initialization: After the cutting equipment is started, the cooling mechanism 500 operates synchronously. The water pump 530 draws coolant from the water collection tank on the cutting machine through the inlet pipe 5100. The coolant is first filtered through the filter element 590, which is a cartridge filter filled with activated carbon filter element, which can effectively remove impurities and particles generated during cutting, ensuring the cleanliness of the coolant and preventing pipe blockage.

[0047] Coolant delivery and distribution: The filtered coolant is pressurized by water pump 530 and delivered through high-pressure resistant water pipe 550. High-pressure resistant water pipe 550 is made of stainless steel and is 1.5 meters long, ensuring the system's durability and high-pressure adaptability. The coolant is delivered to the coolant guide hopper 560, the top of which contacts the inner top wall of the perforated mounting base 510. Its inner side has a conical design, with the inner diameter gradually increasing from bottom to top; this structure allows for smooth coolant diffusion. The bottom outlet of the coolant guide hopper 560 is precisely aligned with the axis of the vertical pipe 540, ensuring accurate injection of coolant into the vertical pipe 540.

[0048] Interface cooling execution: The vertical pipe 540 guides the coolant upwards to the grid pipe 520 embedded inside the porous ceramic disk 200. The coolant penetrates evenly onto the surface of the porous ceramic disk 200 through the grid pipe 520, thereby directly contacting and cooling the blue film beneath the wafer. Since the grid pipe 520 is located directly below the cutting area, the coolant can selectively cool the high-temperature area generated at the cutting point, achieving adaptive localized cooling. The water-blocking ring 5110 surrounds the opening of the grid pipe 520, and its inner vertical cross-section is an isosceles trapezoidal shape, which effectively prevents coolant splashing and ensures that the coolant concentrates its action on the interface between the wafer and the blue film.

[0049] Motion and Support Mechanism: During the cutting process, the precision motion system moves the worktable, and the cooling mechanism 500 adjusts accordingly. The support column 570 and the ball bearings 580 embedded at its bottom provide stable support. The ball bearings 580 are made of tungsten carbide and have a diameter of 10 mm, which can effectively reduce moving friction and ensure the continuity and accuracy of coolant delivery.

[0050] Circulation and Cleaning: Used coolant is collected back into the sump and re-enters the circulation system through inlet pipe 5100. Filter 590 continuously captures cutting debris during this process; users only need to periodically replace or clean filter 590 to maintain efficient system operation, significantly reducing subsequent cleaning workload.

[0051] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0052] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A positioning device for chip cutting and processing, comprising a vacuum base (100), wherein a porous ceramic disk (200) is embedded in the top of the vacuum base (100), and an air pipe (300) is fixedly connected to and communicates with the surface of the vacuum base (100), wherein one end of the air pipe (300) is fixedly connected to and communicates with a vacuum pump (400), characterized in that, A cooling mechanism (500) is fixedly connected to the bottom of the vacuum base (100); The cooling mechanism (500) includes a perforated mounting base (510), a grid tube (520), and a water pump (530). The perforated mounting base (510) is fixedly connected to the bottom of the vacuum base (100), and the horizontal cross-sectional shape of the perforated mounting base (510) is L-shaped. The grid tube (520) is fixedly connected to the interior of the porous ceramic disc (200), and the opening of the grid tube (520) passes through the porous ceramic disc (200) and the vacuum base (100) in sequence and extends to the vacuum base (100). Outside the grid tube (520), the lower surface of the grid tube (520) is fixedly connected to and connected to a vertical tube (540). The bottom of the vertical tube (540) passes through the porous ceramic disc (200), the vacuum base (100) and the hollow mounting base (510) in sequence and is flush with the inner top wall of the hollow mounting base (510). The outlet end of the water pump (530) is fixedly connected to a high-pressure resistant water pipe (550). The center line of the outlet end of the high-pressure resistant water pipe (550) coincides with the center line of the adjacent vertical tube (540) on the same vertical line.

2. The positioning device for chip cutting and processing according to claim 1, characterized in that, The outlet end of the high-pressure water pipe (550) is fixedly connected to a liquid guide bucket (560). The top of the liquid guide bucket (560) is in contact with the inner top wall of the hollow mounting base (510). The ratio of the inner diameter of the opening of the liquid guide bucket (560) to the length of the distance between two adjacent vertical pipes (540) is 5 to 2.

3. The positioning device for chip cutting and processing according to claim 2, characterized in that, The vertical cross-sectional shape of the inner side of the liquid guiding funnel (560) is conical, and the inner diameter of the liquid guiding funnel (560) gradually increases from bottom to top.

4. The positioning device for chip cutting and processing according to claim 1, characterized in that, The high-pressure water pipe (550) is made of stainless steel and has a length of 1.5 meters.

5. The positioning device for chip cutting and processing according to claim 2, characterized in that, The bottom of the liquid guide hopper (560) is fixedly connected to a support column (570). There are two support columns (570), which are symmetrically distributed on both sides of the high-pressure water pipe (550).

6. The positioning device for chip cutting and processing according to claim 5, characterized in that, A ball bearing (580) is embedded in the bottom of the support column (570), and the center point of the ball bearing (580) is located inside the support column (570).

7. The positioning device for chip cutting and processing according to claim 6, characterized in that, The ball (580) is made of tungsten carbide material and has a diameter of ten millimeters.

8. The positioning device for chip cutting and processing according to claim 1, characterized in that, The inlet end of the water pump (530) is detachably connected to a filter element (590), and the inlet end of the filter element (590) is detachably connected to a water inlet pipe (5100).

9. The positioning device for chip cutting and processing according to claim 8, characterized in that, The filter element (590) is a cartridge filter, and the interior of the filter element (590) is filled with an activated carbon filter element.

10. The positioning device for chip cutting and processing according to claim 1, characterized in that, A water-blocking ring (5110) is fixedly connected to the surface of the vacuum base (100). The vertical cross-sectional shape of the inner side of the water-blocking ring (5110) is an isosceles trapezoidal shape. The opening of the grid tube (520) is located inside the water-blocking ring (5110).

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