Coating device for gettering of n-type crystalline silicon wafers

Abstract

The utility model provides a kind of coating device for N type crystalline silicon wafer gettering, it includes support, first roller, second roller and third roller that are sequentially arranged horizontally from top to bottom, drop liquid module, the first roller, second roller and third roller are respectively rotatably arranged on the support, the drop liquid module is located above the first roller, and it can be moved along the length direction of the first roller, to drop liquid medicine to the first roller surface, the drop liquid range of the drop liquid module covers the length of the first roller in length direction, and it is less than the diameter of the first roller in width direction;The outer diameter of the first roller and the second roller is tangent, the second roller and the third roller have gap adapted to the thickness of silicon wafer, and the first roller and the second roller are respectively or each installed on the support by first lifting drive component.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic module manufacturing technology, and in particular to a coating device for gettering N-type crystalline silicon wafers. Background Technology

[0002] In the field of solar cells, with the continuous development of photovoltaic technology, especially crystalline silicon technology, the quality requirements for N-type monocrystalline cells are becoming increasingly stringent. Improving silicon wafer quality and reducing the impurity content within the wafer to enhance product performance has become crucial. Currently, impurity removal treatment before texturing N-type crystalline silicon wafers can effectively improve wafer quality, and for wafers with higher impurity content, the conversion efficiency can also be significantly improved. However, existing coating equipment has a significant drawback: its spray head and rollers are fixed. This prevents flexible adjustments when dealing with silicon wafers of different sizes, resulting in poorer coating effects and difficulty in meeting high-quality coating requirements, thus limiting the effectiveness of silicon wafer getter removal treatment and further improvements in product quality.

[0003] Therefore, it is necessary to design a coating device for gettering N-type silicon wafers to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a coating device for gettering N-type silicon wafers that provides uniform coating and is compatible with silicon wafers of various sizes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a coating device for gettering N-type silicon wafers, comprising a support, a first roller, a second roller, and a third roller arranged horizontally from top to bottom, and a dripping module. The first roller, the second roller, and the third roller are rotatably mounted on the support. The dripping module is located above the first roller and can move along the length direction of the first roller to drip the liquid onto the surface of the first roller. The dripping range of the dripping module covers the length of the first roller in the length direction and is smaller than the diameter of the first roller in the width direction. The outer diameters of the first roller and the second roller are tangent, and there is a gap between the second roller and the third roller adapted to the thickness of the silicon wafer. The first roller and the second roller are respectively or individually mounted on the support via a first lifting drive assembly.

[0006] As a further improvement of the present invention, the dripping module is mounted on the bracket via a horizontal driving component, and the horizontal driving component and the first lifting driving component are electromagnetic sliders.

[0007] As a further improvement of the present invention, the dripping module includes a main infusion pipe, branch pipes and a dripping head connected below each branch pipe. Each branch pipe is equipped with an electronic liquid control valve. The dripping head is lotus-shaped or inverted funnel-shaped, and its end is evenly distributed with multiple dripping holes. The diameter of the dripping holes is 0.1-0.5 mm.

[0008] As a further improvement of the present invention, both the first roller and the second roller include a support roller and a pile surface disposed on the surface of the support roller. The pile length of the pile surface is 0.3-1.5mm and the pile density is 500-2000 piles / cm².

[0009] As a further improvement of this utility model, the suede material is one or more of polyester fiber, nylon fiber and carbon fiber.

[0010] As a further improvement of this utility model, the outer diameter of the first roller is greater than or equal to the outer diameter of the second roller.

[0011] As a further improvement of this utility model, the third roller is mounted on the bracket via a second lifting drive assembly, which is an electromagnetic slider.

[0012] As a further improvement of this utility model, in the horizontal direction, the front and rear sides of the third roller are provided with conveying wheel sets, and the top cut surface of the third roller is flush with the conveying plane of the conveying wheel set.

[0013] As can be seen from the above technical solutions, the coating device for gettering N-type silicon wafers of this utility model has the following advantages: Significantly improves the uniformity of drug coating: The droplet module first drops the drug onto the surface of the first roller, and then utilizes the tangential contact between the first and second rollers to achieve automatic homogenization of the drug between the two rollers. Compared with the traditional single-roller coating method, this design avoids the problem of uneven coating caused by concentrated drop points and insufficient fluidity of the drug. It allows the drug to form a uniform liquid film on the surface of the second roller, thereby ensuring the uniformity of the drug coating on the silicon wafer surface and effectively improving the consistency of gettering effect.

[0014] Enhancing coating stability and reliability: The coordinated operation of the first, second, and third rollers and the conveyor roller assembly forms a stable path for chemical transfer and coating. The gap between the second and third rollers can be adapted to the silicon wafer thickness. The third roller and the conveyor roller assembly ensure smooth transport of the silicon wafer during coating, avoiding chemical deviation or coating amount fluctuations caused by shaking. This results in high repeatability of the coating process, reduces the defect rate, and ensures the stable operation of the gettering process for N-type silicon wafers.

[0015] Simplified equipment maintenance and management: The modular dripping module and independently adjustable roller design facilitate daily maintenance and troubleshooting. When it is necessary to change to a different type of liquid or adjust the coating process, only the dripping module or related rollers need to be disassembled and adjusted, without the need for large-scale modification of the entire unit, effectively reducing maintenance costs and downtime, and improving production efficiency. Attached Figure Description

[0016] Figure 1 This is a front view schematic diagram of a coating apparatus for gettering N-type silicon wafers according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram showing the positions of the conveyor assembly and the three rollers.

[0018] Figure 3 This is a schematic diagram of the dripping module. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Please refer to Figure 1 As shown, this utility model provides a coating device for gettering N-type silicon wafers, which includes a support 10, a first roller 20, a second roller 30, and a third roller 40 arranged horizontally from top to bottom, a dropper module 70, and a control system. The support 10 includes a crossbeam and vertical rods located below both ends of the crossbeam. The first roller 20, the second roller 30, and the third roller 40 are rotatably disposed between two vertical rods.

[0021] Please participate together Figure 2 As shown, the outer diameters of the first roller 20 and the second roller 30 are tangent, meaning that the outer sides of the first roller 20 and the second roller 30 are in contact and have a certain coefficient of friction. When the second roller 30 rotates, it can drive the first roller 20 to rotate. There is a gap between the second roller 30 and the third roller 40 that is adapted to the thickness of the silicon wafer 100.

[0022] The first roller 20 and the second roller 30 are mounted on the bracket 10 via the first lifting drive assembly 50. The first roller 20 and the second roller 30 move synchronously up and down along the vertical rod under the drive of the first lifting drive assembly 50. The first roller 20, the second roller 30, and the third roller 40 each include a support roller and a pile surface on the surface of the support roller. The pile length of the pile surface is 0.3-1.5 mm, and the pile density is 500-2000 fibers / cm². The pile surface material is one or more of polyester fiber, nylon fiber, and carbon fiber.

[0023] The third roller 40 is mounted on the bracket 10 via the second lifting drive assembly 60 and moves up and down along the vertical rod under the drive of the second lifting drive assembly 60. The first lifting drive assembly 50 and the second lifting drive assembly 60 are preferably electromagnetic sliders. The electromagnetic slider is an existing structure, specifically including an electromagnetic coil, an iron core, a slider, and a guide rail. The electromagnetic coil is wound around the iron core and fixed to the bracket 10; the slider is connected to the roller and nested within the guide rail, allowing it to move linearly along the guide rail. The bracket 10 is also equipped with a position sensor matched to the electromagnetic slider to monitor the slider's position.

[0024] The dripping module 70 is located above the first roller 20, specifically mounted on a crossbeam via a horizontal drive assembly 80, which is an electromagnetic slider. Driven by the electromagnetic slider, the dripping module 70 can move along the length of the first roller 20 to drip the medicine onto its surface. The dripping range of the dripping module 70 covers the length of the first roller 20 in the length direction and is smaller than the diameter of the first roller 20 in the width direction.

[0025] Please refer to Figure 3 As shown, the dispensing module 70 includes a main infusion pipe (not shown), branch pipes 71, and dispensing heads 72 connected to the bottom of each branch pipe 71. Each branch pipe 71 is equipped with an electronic liquid control valve 73 to achieve precise control of the liquid flow rate, improving the accuracy and stability of liquid supply during the coating process. The dispensing head 72 is lotus-shaped or inverted funnel-shaped, with multiple dispensing holes evenly distributed at its end. The diameter of the dispensing holes is 0.1-0.5 mm, and the spacing between the dispensing holes is 0.5-1 mm. This design ensures more uniform liquid flow and guarantees the uniformity of coating on the silicon wafer surface.

[0026] In this embodiment, the outer diameter of the first roller 20 is greater than or equal to the outer diameter of the second roller 30. This arrangement prevents liquid in the dropper assembly 70 from dripping directly onto the second roller 30 without passing through the first roller 20.

[0027] Please refer to Figure 2 As shown, in the horizontal direction, conveyor wheel sets 80 are provided on both the front and rear sides of the third roller 40, and the top cross-section of the third roller 40 is flush with the conveying plane of the conveyor wheel set 80. The third roller 40 moves up and down along the vertical rod under the drive of the second lifting drive assembly 60, and can be matched with conveyor wheel sets 80 of different height specifications.

[0028] The working process of the coating device of this utility model is as follows: Parameter preset and equipment calibration: The thickness of the N-type silicon wafer to be processed is input into the control system, and the target heights of the first, second, and third rollers are preset (adjusted via an electromagnetic slider drive component). Simultaneously, parameters such as the dripping flow rate and horizontal movement speed of the dripping module are set. Position sensors provide real-time feedback on the roller positions, and the control system automatically calibrates to the preset heights. The dripping head's flow rate is calibrated via an electronic liquid control valve to ensure uniform liquid distribution from the dripping orifice. Drug delivery and homogenization: The dripping module moves along the length of the first roller, and the drug solution is evenly dripped onto the surface of the first roller through the dripping head. When the second roller rotates, it drives the first roller to rotate synchronously. The drug solution is initially homogenized in the contact area between the two rollers through compression and capillary action of the carpet surface, forming a liquid film of uniform thickness. Silicon wafer coating and transport: The silicon wafer is horizontally transported by the front and rear transport roller sets, passing through the gap between the second and third rollers. The homogenizing solution on the surface of the second roller is uniformly transferred upon contact with the silicon wafer, forming a getter film of the target thickness. The top cut surface of the third roller is flush with the plane of the transport roller set, ensuring a smooth transition of the silicon wafer and avoiding scratching or uneven coating of the solution due to height differences. When processing silicon wafers of different thicknesses: the first and second rollers move up and down synchronously via electromagnetic sliders to quickly match the height of the upper surface of the silicon wafer; the third roller moves up and down independently to adjust the gap with the second roller, and the position sensor provides real-time feedback and correction. Dynamic drip compensation: When the drip module moves along the length of the first roller, the control system calculates the silicon wafer transmission speed and drip frequency in real time, and dynamically adjusts the opening of the electronic liquid control valve to ensure that the liquid flow rate matches the coating speed and avoids liquid accumulation or missing at the edges.

[0029] Compared to traditional coating equipment with a single upper roller, the coating device of this application improves the coating uniformity of silicon wafers by about 18%, while saving 30% of the chemical solution.

[0030] The terms used herein, such as “upper,” “lower,” “front,” and “back,” indicating relative spatial positions, are for illustrative purposes to describe the relationship of one feature relative to another, as shown in the accompanying drawings. It is understood that, depending on the product's placement, these terms may be intended to include different orientations besides those shown in the figures, and should not be construed as limiting the claims.

[0031] Furthermore, the above embodiments are only used to illustrate the present utility model and are not intended to limit the technical solutions described in the present utility model. The understanding of this specification should be based on those skilled in the art. Although the present utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications or equivalent substitutions to the present utility model. All technical solutions and improvements that do not depart from the spirit and scope of the present utility model should be covered within the scope of the claims of the present utility model.

Claims

1. A coating device for gettering of N-type crystalline silicon wafers, characterized in that: The device includes a support, a first roller, a second roller, and a third roller arranged horizontally from top to bottom, and a dripping module. The first roller, the second roller, and the third roller are rotatably mounted on the support. The dripping module is located above the first roller and can move along the length of the first roller to drip the medicine onto the surface of the first roller. The dripping range of the dripping module covers the length of the first roller in the length direction and is smaller than the diameter of the first roller in the width direction. The outer diameters of the first roller and the second roller are tangent to each other, and there is a gap between the second roller and the third roller that is adapted to the thickness of the silicon wafer. The first roller and the second roller are respectively or individually mounted on the support via a first lifting drive assembly.

2. The coating device for N-type crystalline silicon wafer gettering according to claim 1, characterized in that: The dripping module is mounted on the bracket via a horizontal drive assembly, and the horizontal drive assembly and the first lifting drive assembly are electromagnetic sliders.

3. The coating device for N-type crystalline silicon wafer gettering according to claim 1, characterized in that: The drip module includes a main infusion tube, branch tubes, and drip heads connected to the bottom of each branch tube. Each branch tube is equipped with an electronic liquid control valve. The drip head is lotus-shaped or inverted funnel-shaped, with multiple drip holes evenly distributed at its end. The diameter of the drip holes is 0.1-0.5 mm.

4. The coating device for N-type crystalline silicon wafer gettering according to claim 1, wherein: Both the first roller and the second roller include a support roller and a pile surface disposed on the surface of the support roller. The pile length of the pile surface is 0.3-1.5mm and the pile density is 500-2000 piles / cm².

5. The coating apparatus for gettering N-type silicon wafers as described in claim 1, characterized in that: The outer diameter of the first roller is greater than or equal to the outer diameter of the second roller.

6. The coating device for N-type crystalline silicon wafer gettering according to claim 1, wherein: The third roller is mounted on the bracket via a second lifting drive assembly, which is an electromagnetic slider.

7. The coating device for N-type crystalline silicon wafer gettering according to claim 1, wherein: In the horizontal direction, the third roller is provided with conveyor wheel sets on both the front and rear sides, and the top cross-section of the third roller is flush with the conveying plane of the conveyor wheel set.

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