A method for making a knotless screen

Abstract

The present invention belongs to the technical field of high-precision screen production, and specifically relates to a method for producing a knotless screen. The method comprises the following steps: positioning, marking and laser cutting. The technical solution provided by the present invention releases the stress of the steel wire by pre-cutting the steel wire, thereby reducing the problem of inaccurate positioning caused by the deformation of the steel wire. In addition, in each cutting area, the laser cuts from the left and right sides to the middle in sequence, further reducing the problem of steel wire deformation, and ultimately improving the yield of the product.

Description

Technical Field

[0001] The invention belongs to the technical field of high-precision screen production, and in particular relates to a method for producing a knotless screen. Background Art

[0002] Screen printing is a printing technology that uses the basic principle that the patterned mesh of the screen allows the paste to pass through, while the non-patterned mesh does not. Using screen printing technology, conductive paste containing metal (such as silver (Ag) paste and aluminum (Al) paste) can be printed on the silicon wafer through the mesh of the screen, thereby forming a good ohmic contact with the silicon wafer.

[0003] Ordinary screens are composed of meshes of different mesh sizes woven from stainless steel wire and latex coated on the mesh on the screen frame. The latex is removed at the openings of the screen pattern design, so that when the scraper brushes over the screen, the slurry applied on the screen passes through the pattern openings and is printed on the substrate. The future trend of screen design is: higher and higher mesh counts, thinner and thinner line diameters, and narrower line widths. However, due to the presence of mesh knots, the uniformity of the printed line type of conventional screens is poor, which is bound to affect the trend of ultra-fine line printing and further narrowing of the fine grid line openings. Therefore, the market demand for knotless screens has emerged.

[0004] Knotless screens simply mean that there are no knots in the fine grid opening area, and the screen angle changes from oblique to straight. The aspect ratio and line type of knotless screens after printing are significantly better than those of conventional screens. By improving the aspect ratio and optimizing the line type, the short-circuit current, opening voltage, and filling of the battery cell can be greatly improved, thereby significantly improving efficiency. At the same time, the narrowing of the line width can significantly reduce unit consumption.

[0005] The processing process of knotless screen is roughly to scan the screen, generate the screen pattern, compare the position of the steel wire and the position of the fine grid, and remove the knots at the corresponding position of the fine grid on the screen according to the distance requirements between the two. Specifically, it means using laser to interrupt the horizontal steel wire on the screen, and removing the cut steel wire will achieve knotless at the fine grid.

[0006] During operation, the laser cuts from one end to the other. Since the steel wire itself has tension, the steel wire will deform to both sides at the moment the laser cuts off. During the wire drawing process, since stainless steel is easy to deform and has low strength, yarn breakage and board bursting are likely to occur. Board bursting refers to the phenomenon that the screen is abnormally damaged during the screen printing process, causing the slurry to be printed on a large area of ​​the battery cell. Summary of the invention

[0007] The invention provides a method for manufacturing a mesh plate without mesh knots, which is used to solve the problems of yarn breakage and plate explosion during current spinning.

[0008] In order to solve the above technical problems, the technical solution of the present invention is: the method for making the knotless screen plate comprises the following steps:

[0009] 1) Positioning: According to the graphic parameters of the fine grid and the scanned screen pattern, determine the position and length of the warp wire to be cut;

[0010] 2) Marking: Divide the wire to be removed into cutting areas according to the positioning situation, and mark both ends of the cutting area;

[0011] 3) Laser cutting: The steel wire in the cutting area is cut by laser, and the cutting order of at least part of the section in the cutting area is to cut alternately from both ends and gradually move toward the center.

[0012] Optionally, in the alternating cutting areas from both ends, the laser cuts the target meridian along the same latitude each time, and after each cutting, it switches to a position close to the other end and cuts once, and this cycle repeats.

[0013] Optionally, the cutting area is divided into a shorter pre-cut area and a longer positioning cutting area, and segment marks are made between the two areas. During laser cutting, the pre-cut area is cut first, and then the positioning cutting area is cut.

[0014] Optionally, the cutting order of the steel wire in the pre-cutting area is from one end of the cutting area close to the segmentation mark to the segmentation mark.

[0015] Optionally, the first cut of the positioning cutting area starts from one end of the cutting area.

[0016] Optionally, the length of the cutting area is 3-6 mm, and the length of the pre-cut area is 1.4-1.6 mm.

[0017] Optionally, in step 3), the laser uses a camera to capture the steel wire and performs positioning cutting as planned.

[0018] Optionally, the cutting area cuts multiple rows of meridians at the same latitude at the same time according to the fine grid width.

[0019] The technical solution provided by the present invention releases the stress of the steel wire by pre-cutting the steel wire, thereby reducing the problem of inaccurate positioning caused by steel wire deformation. In addition, in each cutting area, the laser cuts from the left and right sides to the middle in sequence, which further reduces the problem of steel wire deformation and ultimately improves the product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flow chart of a method for making a knotless screen according to the present invention;

[0021] Figure 2 It is a schematic diagram of a specific implementation of the knotless mesh drawing design of the present invention;

[0022] Figure 3It is a schematic diagram of a specific implementation method of the area division of the knotless screen according to the present invention;

[0023] Figure 4 It is a schematic diagram of a specific implementation of the cutting sequence within the cutting area of ​​the present invention.

[0024] As shown in the figure:

[0025] 10-drawing area, 20-cutting area, 30-pre-cutting area, 40-positioning cutting area, 50-cutting line. DETAILED DESCRIPTION

[0026] For ease of understanding, the method for making the knotless screen is described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0027] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation and positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] like Figure 1 As shown, the method for making the knotless screen comprises the following steps:

[0030] 1) Positioning: According to the graphic parameters of the fine grid and the scanned screen pattern, determine the position and length of the warp wire to be cut. The target pattern is as follows: Figure 2 As shown, it includes a wire drawing area 10 left for three parallel fine grids;

[0031] The length of a fine grid is generally 150-180mm, and the width generally needs to occupy 2-4 units. In order to achieve the knot-free fine grid in the future, the horizontal warp in the warp and weft weaving needs to be removed. The length of the removed warp needs to be slightly longer than the fine grid, and the width should also be slightly wider than the parameters of the fine grid. Removing one warp can obtain an area with a width of two grids, removing two warps can obtain an area with a width of three grids, and so on. Figure 2 In the figure, three longitude lines are removed to leave four grid widths for fine grid use.

[0032] 2) Marking: Divide the steel wire to be removed into cutting areas according to the positioning situation, mark both ends of the cutting area, and then set a segmentation mark between the two ends. The segmentation mark divides the cutting area into a shorter pre-cutting area and a longer positioning cutting area;

[0033] The cutting area is usually set at 3-6 mm, that is, the fine grid is divided into several cutting areas, such as Figure 3 As shown, each wire drawing area includes a plurality of cutting areas 20, and a fine grid can be divided into cutting areas 20 of different lengths as needed. Figure 3 For example, the first strip can be divided into three sections with the upper and lower parallel fine grids, and the second and third strips can be divided into two sections. The second section of the first strip is shorter than the first section with the length of the second strip, and the second section of the third strip is shorter than the above two strips. In this way, the corresponding cutting area 20 can be cut first during laser cutting, and then the second section can be moved to the cutting area to improve the efficiency of laser cutting. After the cutting area 10 is divided, it is marked at both ends. The marking method is a conventional technical means in this field.

[0034] I won’t repeat it any more;

[0035] Continue to see Figure 3 , wherein the frame is the pre-cut area 30 divided, the length of the pre-cut area is set to 1.5 mm, the remaining part of the cutting area 20 is the positioning cutting area 40, and the segmentation mark between the two is a conventional technical means in the field, which will not be repeated here;

[0036] 3) Laser cutting: First, laser cut the steel wire in the pre-cut area, and then laser cut the steel wire in the positioning cutting area. The laser uses a camera to capture the steel wire and perform positioning cutting according to the plan. The specific cutting sequence is as follows: Figure 4 shown.

[0037] Continue to see Figure 4 In the pre-cut area, the wire is cut from the end of the cutting area close to the segment mark to the segment mark, that is, in the order of Roman numerals. Of course, alternating cutting can also be performed, that is, in the order of IV-II-IV-III.

[0038] Continue to see Figure 4 In the positioning cutting area, the cutting order of the steel wire is from both ends to the center, which can be carried out in the order of the Arabic numerals in the figure, or it can be reversed, starting from 2 for the first cut, and then returning to 1-4-3-6-5-8-7-10-9-12-11-14-13-15. The laser cuts the target meridian along the same latitude each time, and switches to a position close to the other end for cutting each time, and alternates back and forth in this way. Of course, it can also be done several times before changing sides, and the number of times each time can be the same or different. The overall trend is from both ends to the center, which belongs to the inventive concept of the present invention.

[0039] The cutting area cuts multiple longitudes of the same latitude at the same time, that is, Figure 4 As shown in FIG. 5 , a laser running path is a thickened cutting line 50 .

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for making a knotless screen, characterized in that: The steps include: 1) Positioning: Determine the position and length of the warp wire to be cut according to the graphic parameters of the fine grid and the scanned screen pattern; 2) Marking: Divide the wire to be removed into cutting areas according to the positioning situation and mark both ends of the cutting area; 3) Laser cutting: The steel wire in the cutting area is cut by laser, and the cutting order of at least part of the section in the cutting area is to cut alternately from both ends and gradually move toward the center.

2. The method for making a knotless screen according to claim 1, characterized in that: In the alternating cutting area from both ends, the laser cuts the target meridian along the same latitude each time, and switches to a position close to the other end for each cutting, alternating back and forth like this.

3. The method for making a knotless screen according to claim 1, characterized in that: The cutting area is divided into a shorter pre-cut area and a longer positioning cutting area, and segment marks are made between the two areas. During laser cutting, the pre-cut area is cut first, and then the positioning cutting area is cut.

4. The method for making a knotless screen according to claim 3, characterized in that: The cutting order of the steel wire in the pre-cutting area is from one end of the cutting area close to the segmentation mark to the segmentation mark.

5. The method for making a knotless screen according to claim 3, characterized in that: The first cut of the positioning cutting area starts from one end of the cutting area.

6. The method for making a knotless screen according to claim 3, characterized in that: The length of the cutting area is 3-6 mm, and the length of the pre-cut area is 1.4-1.6 mm.

7. The method for making a knotless screen according to claim 1, characterized in that: In step 3), the laser uses a camera to capture the wire and performs positioning cutting as planned.

8. The method for making a knotless screen according to claim 1, characterized in that: The cutting area cuts multiple rows of meridians at the same latitude at the same time according to the fine grid width.

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