Multi-layer full-opening steel plate and preparation method thereof

Abstract

The invention belongs to the technical field of electrode printing, and discloses a multi-layer full-opening steel plate and a preparation method thereof. The multi-layer full-opening steel plate comprises a plurality of stacked shaping layers and a framework layer arranged on the uppermost shaping layer. The ink storage channel is formed by the plurality of shaping patterns on the plurality of shaping layers, so that the ink passing amount of the ink storage channel is remarkably increased compared with that of a single-layer structure adopted by a traditional full-opening steel plate, and therefore it can be ensured that during narrow line width printing, slurry pushed by a scraper can continuously infiltrate meshes and be stably transferred to a battery piece; therefore, sufficient slurry supply in the printing process is ensured, the plasticity and fullness of the grid line are ensured, and the grid breaking ratio can be reduced. Namely, the scraper moves to be matched with a multi-layer mesh structure formed by a plurality of shaping layers, direct ink extrusion of a traditional single-layer steel plate is converted into controlled-release ink of an ink storage channel, and the uniformity and reliability of slurry transfer during narrow-line-width printing are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrode printing, and particularly to a multi-layer full-opening steel plate and a preparation method thereof. Background Art

[0002] In the field of photovoltaic cell manufacturing, with the development of high-efficiency cell technologies such as TOPCon (Tunnel Oxide Passivated Contact cell) and HJT (Heterojunction Solar Cell), the narrow linewidth printing process (e.g., the fine grid line of TOPCon cell ≤ 6μm) has put forward higher requirements for the accuracy of the printing steel plate, so as to reduce the electrode resistance loss through finer grid lines and thus improve the cell conversion efficiency.

[0003] However, traditional full-opening steel plates usually adopt a single-layer structure. When applied to narrow linewidth printing, the effective ink passing volume of its single-layer mesh holes decreases significantly with the reduction of the linewidth, resulting in insufficient slurry supply during the printing process. It is difficult for the slurry to fully fill the mesh holes under the pressure of the squeegee and transfer to the surface of the cell sheet, causing the grid lines to be plastically unfilled and the proportion of broken grids to increase.

[0004] Therefore, the above problems need to be solved urgently. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-layer full-opening steel plate to ensure sufficient slurry supply during the printing process, so as to ensure the full plasticity of the grid lines and reduce the proportion of broken grids at the same time.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] A multi-layer full-opening steel plate, the multi-layer full-opening steel plate includes a plurality of stacked shaping layers and a skeleton layer arranged on the uppermost shaping layer, wherein:

[0008] A plurality of the shaping layers are each formed with a shaping pattern, and a plurality of the shaping patterns enclose an ink storage channel capable of temporarily storing slurry during printing;

[0009] The skeleton layer forms an ink permeation pattern, the ink permeation pattern corresponds to a plurality of the shaping patterns one by one, and the opening width of the ink permeation pattern is greater than the opening width of a plurality of the shaping patterns.

[0010] Preferably, the opening widths of a plurality of the shaping patterns are different, so that the side wall of the ink storage channel changes along a preset path.

[0011] Preferably, the opening widths of a plurality of the shaping patterns gradually decrease from top to bottom.

[0012] Preferably, the opening widths of a plurality of the shaping patterns gradually increase from top to bottom.

[0013] Preferably, the skeleton layer is made of a metal material.

[0014] Preferably, a plurality of the shaping layers are integrally formed on the skeleton layer.

[0015] A preparation method for preparing the above multi-layer fully open steel plate, the preparation method of the multi-layer fully open steel plate includes:

[0016] Prepare the skeleton layer, and deposit the skeleton layer by electroforming process;

[0017] Prepare the shaping layer, and grow a plurality of the shaping layers on the skeleton layer by electroplating process.

[0018] Preferably, the preparation method of the multi-layer fully open steel plate further includes:

[0019] Before preparing the shaping layer, laser engrave or lithograph an ink-permeating pattern on the skeleton layer.

[0020] Preferably, the preparation method of the multi-layer fully open steel plate further includes:

[0021] After preparing the shaping layer, detect the flatness of a plurality of the shaping layers and the skeleton layer, and detect the opening width of a plurality of the shaping patterns and the ink-permeating pattern.

[0022] Preferably, the preparation method of the multi-layer fully open steel plate further includes:

[0023] After preparing the shaping layer, perform a printing test on the multi-layer fully open steel plate, and simulate the movement of the squeegee to verify the fatigue resistance of the multi-layer fully open steel plate.

[0024] Advantages of the present invention:

[0025] The present invention consists of a plurality of shaping patterns on a plurality of shaping layers to form an ink storage channel, so that the ink passing amount of the ink storage channel is significantly increased compared with the single-layer structure adopted by the traditional fully open steel plate. Therefore, when printing narrow line widths, the slurry pushed by the squeegee can continuously infiltrate the mesh holes and be stably transferred to the battery chip, thereby ensuring sufficient slurry supply during the printing process to ensure plump plasticity of the grid lines and reducing the proportion of broken grids at the same time. That is to say, through the cooperation of the squeegee movement and the multi-layer mesh hole structure composed of a plurality of shaping layers, the "direct extrusion of ink" of the traditional single-layer steel plate is transformed into "controlled ink release of the ink storage channel", significantly improving the uniformity and reliability of slurry transfer during narrow line width printing. In addition, it can also eliminate the loss of battery conversion efficiency caused by unstable ink supply, and meet the manufacturing requirements of high-precision metallized electrodes for efficient batteries such as TOPCon and HJT. Description of the Drawings

[0026] Figure 1Structural schematic of the multi-layer fully open steel plate provided by the present invention Figure 1 ;

[0027] Figure 2 Structural schematic of the multi-layer fully open steel plate provided by the present invention Figure 2 。

[0028] In the figure:

[0029] 100, shaping layer; 200, skeleton layer; 300, ink storage channel. Specific embodiments

[0030] Before explaining any embodiments of the present application in detail, it should be understood that the present application is not limited to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0031] In the present application, the terms "comprise", "include", "have" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or apparatus comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or apparatus. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising such element.

[0032] In the present application, the term "and / or" describes the relationship between associated objects and indicates that three relationships can exist. For example, a centrifugal vortex magnetic pump and / or a centrifugal vortex magnetic pump can represent: the sole existence of a centrifugal vortex magnetic pump, the simultaneous existence of a centrifugal vortex magnetic pump and a centrifugal vortex magnetic pump, and the sole existence of a centrifugal vortex magnetic pump. Additionally, in the present application, the character " / " generally represents an "and / or" relationship between the associated objects before and after.

[0033] In the present application, the terms "connect", "combine", "couple", "mount" can be direct connection, combination, coupling or mounting, or indirect connection, combination, coupling or mounting. Among them, by way of example, direct connection means that two parts or components are connected together without the need for an intermediate member, and indirect connection means that two parts or components are respectively connected to at least one intermediate member, and these two parts or components are connected through the intermediate member. In addition, "connect" and "couple" are not limited to physical or mechanical connection or coupling and can include electrical connection or coupling.

[0034] In this application, those of ordinary skill in the art will understand that relative terms used in connection with quantities or conditions (such as "about", "approximately", "substantially", etc.) are intended to include the stated value and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances resulting from manufacturing, assembly, use, etc. associated with a particular value. Such terms should also be considered to disclose a range defined by the absolute values of two endpoints. Relative terms may refer to a plus or minus of a certain percentage (such as 1%, 5%, 10% or more) of the indicated value. Numerical values that do not use relative terms should also be disclosed as specific values with tolerances. In addition, when expressing relative angular positional relationships (such as substantially parallel, substantially perpendicular), "substantially" may refer to a plus or minus of a certain number of degrees (such as 1 degree, 5 degrees, 10 degrees or more) based on the indicated angle.

[0035] In this application, those of ordinary skill in the art will understand that the functions performed by components can be performed by one component, multiple components, one part, or multiple parts. Similarly, the functions performed by parts can also be performed by one part, one component, or a combination of multiple parts.

[0036] In this application, the orientation terms such as "upper", "lower", "left", "right", "front", "rear", etc. are described based on the orientation and positional relationship shown in the drawings, and should not be construed as limiting the embodiments of this application. In addition, in the context, it should also be understood that when it is mentioned that one element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element. It should also be understood that orientation terms such as the upper side, lower side, left side, right side, front side, rear side, etc. not only represent the positive orientation, but can also be understood as the side orientation. For example, the lower side can include directly below, lower left, lower right, lower front, and lower rear, etc.

[0037] Please refer to Figure 1 and Figure 2 , this embodiment provides a multi-layer fully open steel plate. The multi-layer fully open steel plate includes a plurality of stacked shaping layers 100 and a skeleton layer 200 disposed above the uppermost shaping layer 100. Among them, a plurality of shaping layers 100 are each formed with a shaping pattern. A plurality of shaping patterns enclose an ink storage channel 300 that can temporarily store the slurry during printing, and transfer the slurry to the surface of the battery cell through the ink storage channel 300. The skeleton layer 200 forms an ink-permeable pattern, and the ink-permeable pattern corresponds to each of the plurality of shaping patterns one by one. The opening width of the ink-permeable pattern is greater than the opening width of the plurality of shaping patterns.

[0038] When the squeegee scrapes across the surface of the skeleton layer 200, the slurry first enters the openings of the ink-permeable patterns, and then converges into the ink storage channels 300 surrounded by several shaping patterns. Subsequently, the slurry pushed by the squeegee can continuously enter the ink storage channels 300, so that the slurry can be stably and continuously printed onto the battery cell.

[0039] It can be understood that the ink storage channels 300 are formed by several shaping patterns on several shaping layers 100, so that the ink passing capacity of the ink storage channels 300 is significantly increased compared with the single-layer structure used in traditional fully open steel plates. Thus, when printing narrow line widths, the slurry pushed by the squeegee can continuously infiltrate the mesh holes and be stably transferred to the battery cell, thereby ensuring sufficient slurry supply during the printing process to ensure plump plastic grid lines, while reducing the proportion of broken grids. That is to say, through the cooperation of the squeegee movement and the multi-layer mesh structure composed of several shaping layers 100, the "direct extrusion ink output" of the traditional single-layer steel plate is transformed into "controlled ink release of the ink storage channels 300", significantly improving the uniformity and reliability of slurry transfer during narrow line width printing. In addition, it can also eliminate the loss of battery conversion efficiency caused by unstable ink supply, and meet the manufacturing requirements of high-precision metallized electrodes for high-efficiency batteries such as TOPCon and HJT.

[0040] It should be noted that due to design differences in different battery cells such as overlapping tiles and half cells, the demand for grid line linear morphologies such as arcs and variable cross-sections, which are non-trapezoidal structures, is becoming increasingly diverse. The performance bottleneck of traditional fully open steel plates is gradually emerging in practical applications.

[0041] Therefore, in this embodiment, the opening widths of several shaping patterns are different, so that the side walls of the ink storage channels 300 change along a preset path.

[0042] With such a setting, when the squeegee squeezes the slurry flowing through the ink storage channels 300, the slurry is directionally flowed under the constraint of the side walls, so that the outline of the grid lines is restricted by the widths of various positions of the side walls of the ink storage channels 300, thereby printing grid lines with a specific linear morphology. Compared with the traditional method of relying on post-processing to adjust the line type of the steel plate, it has higher precision controllability and consistency, and higher processing efficiency.

[0043] Exemplarily, the opening widths of several shaping patterns gradually decrease from top to bottom. It can be understood that the gradually decreasing opening widths of the shaping patterns from top to bottom form an ink storage channel 300 structure that is wider at the top and narrower at the bottom. The larger openings on the upper side can accommodate more slurry, increasing the ink storage capacity. In addition, during printing, the slurry can flow more smoothly from the wider shaping patterns on the upper side into the narrower shaping patterns on the lower side, ensuring that sufficient slurry is delivered to the surface of the battery cell during narrow line width printing, thereby ensuring the plumpness of the grid lines and reducing the proportion of broken grids.

[0044] More importantly, since the opening width of the lowermost shaping layer 100 is smaller than that of the upper shaping layer 100, when the steel plate leaves the battery cell, the slurry usually breaks at the top surface of the lowermost shaping layer 100. At the same time, affected by the frictional force when the steel plate leaves and the viscosity of the slurry, finally, grid lines with a frustum-shaped or conical shape that is narrower at the top and wider at the bottom are shaped to meet the design requirements of different battery cells such as overlapping tiles and half cells. For example, in the case of overlapping tile batteries, the grid lines that are narrower at the top and wider at the bottom can reduce the shading area during lamination and improve the photoelectric conversion efficiency of the battery.

[0045] In other embodiments, the opening widths of several shaping patterns gradually increase from top to bottom, so that the ink storage channel 300 is arranged to be narrower at the top and wider at the bottom. When the steel plate leaves the battery cell, due to the larger opening at the lower side and sufficient ink storage space, when the slurry flows downward, under the action of viscous force and frictional force, the slurry usually breaks at the top surface of the uppermost shaping layer 100. Compared with the way of breaking at the lowermost shaping layer 100, it makes the side wall of the grid line closer to vertical, avoiding the inclined side walls of the frustum shape or cone shape. That is to say, the ink storage channel 300 is arranged to be narrower at the top and wider at the bottom, and the slurry in the ink storage channel 300 is also generally arranged to be narrower at the top and wider at the bottom. When the steel plate leaves the battery cell, more slurry at the lower side will move upward due to the action of viscous force and frictional force to make up for the problem of less slurry at the upper side, so that the grid line approaches vertical, and further meets the stringent requirements of high-efficiency batteries for the vertical side wall line type. For example, the high-width ratio grid lines of HJT batteries to reduce the electrode shading area and improve the current transmission efficiency at the same time.

[0046] To improve the service life of the multi-layer full-opening steel plate, the skeleton layer 200 is made of a metal material. It can be understood that the metal material has relatively high tensile strength and compressive strength. Under the high-frequency pressure load of the reciprocating movement of the squeegee, it can prevent the skeleton layer 200 from undergoing plastic deformation or fracture, ensuring the long-term stability of key parameters such as the opening width and side wall angle of the ink storage channel 300, so as to maintain the consistency of grid line printing. Especially during narrow line width printing, the rigidity of the skeleton layer 200 made of metal material can inhibit the local collapse of the steel plate caused by the squeegee pressure, and avoid the problem of poor slurry diversion or line type defects caused by structural deformation. In this embodiment, the skeleton layer 200 is made of a nickel-based alloy. Of course, in other embodiments, the skeleton layer 200 can also be made of materials such as stainless steel and aluminum alloy, and no specific requirements and restrictions are made in this regard.

[0047] To improve the structural strength of the multi-layer full-opening steel plate, several shaping layers 100 are integrally formed on the skeleton layer 200. With such an arrangement, compared with the bonding or welding method of multi-layer assembly, it can avoid peeling and misalignment caused by interlayer shear force under the reciprocating pressure of the squeegee and the dynamic load of the steel plate quickly separating from the battery cell, ensuring the long-term stability of the ink storage channel 300 and avoiding the deviation of the grid line type caused by interlayer displacement.

[0048] This embodiment further provides a method for preparing the above-mentioned multi-layer fully open steel plate, and the method for preparing the multi-layer fully open steel plate includes:

[0049] Prepare the skeleton layer 200, and deposit the skeleton layer 200 by electroforming process;

[0050] The shaping layer 100 is prepared, and a plurality of shaping layers 100 are grown on the skeleton layer 200 by using an electroplating process.

[0051] It is understood that the electroforming process can achieve the preparation of the skeleton layer 200 with a dimensional tolerance of ±1μm through electrochemical deposition, which has higher precision than mechanical processing, and can ensure that the conductive path and support structure of the skeleton layer 200 are completely consistent with the design model, providing a good benchmark for the shaping layer 100. It is also understood that the electroplating process can grow shaping layers 100 of different thicknesses / widths layer by layer on the surface of the skeleton layer 200 by adjusting the current density, time and electrolyte composition.

[0052] In order to ensure the accuracy of the processing size, the preparation method of the multi-layer fully open steel plate also includes:

[0053] Before preparing the shaping layer 100 , an ink-permeable pattern is laser engraved or photolithographically formed on the skeleton layer 200 .

[0054] It is understandable that both laser engraving and photolithography can achieve fine processing below the sub-millimeter level. Laser engraving achieves accurate line width depiction through focusing the light spot, and photolithography achieves line width pattern transfer through ultraviolet exposure and mask. Both are far superior to traditional mechanical processing and meet the needs of fine ink-transmitting patterns. In addition, both laser engraving and photolithography can avoid material deformation caused by mechanical contact to ensure the accuracy of processing dimensions.

[0055] In order to improve the yield rate of the multi-layer fully open steel plate, the preparation method of the multi-layer fully open steel plate also includes:

[0056] After the shaping layer 100 is prepared, the flatness of some shaping layers 100 and the skeleton layer 200 is detected, and the opening widths of some shaping patterns and ink-permeable patterns are detected.

[0057] It should be noted that the above detection method can select any existing detection method according to the actual application scenario. For example, a laser level meter is used for detection, the laser beam is used to scan the surface to be measured, the reflected light signal is received to calculate the height of each point on the surface, and a three-dimensional profile is constructed. Another example is the detection method of a combination of a scanning electron microscope SEM and an energy dispersive X-ray spectrometer EDS, where a high-resolution SEM is used to observe the microscopic morphology of the opening edge, detect burrs or coating defects, and EDS is used to simultaneously analyze the element distribution.

[0058] In particular, the method for preparing the multi-layer fully open steel plate also includes:

[0059] After preparing the shaping layer 100, a printing test is performed on the multi-layer fully open steel plate to verify the anti-fatigue performance of the multi-layer fully open steel plate by simulating the movement of the squeegee.

[0060] With such a setting, by simulating the reciprocating movement of the squeegee on the surface of the steel plate, the mechanical stress borne by the steel plate during the printing process is directly restored to expose potential fatigue defects in advance, avoiding quality problems caused by the fatigue failure of the steel plate during actual printing.

[0061] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, several obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A multi-layer fully open steel plate, characterized in that: The multi-layer fully open steel plate comprises a plurality of stacked shaping layers (100) and a skeleton layer (200) arranged on the uppermost shaping layer (100), wherein: A plurality of the shaping layers (100) are formed with shaping patterns, and the plurality of the shaping patterns enclose an ink storage channel (300) capable of temporarily storing slurry during printing, and the slurry is transferred to the surface of the battery cell through the ink storage channel (300); The skeleton layer (200) forms an ink-permeable pattern, the ink-permeable pattern corresponds one-to-one to a plurality of the shaping patterns, and the opening width of the ink-permeable pattern is greater than the opening width of the plurality of the shaping patterns.

2. A multi-layer fully open steel plate according to claim 1, characterized in that: The opening widths of the plurality of shaping patterns are different, so that the side wall of the ink storage channel (300) changes along a preset path.

3. A multi-layer fully open steel plate according to claim 2, characterized in that: The opening widths of the plurality of shaping patterns gradually decrease from top to bottom.

4. A multi-layer fully open steel plate according to claim 2, characterized in that: The opening widths of the plurality of shaping patterns gradually increase from top to bottom.

5. The multi-layer fully open steel plate according to claim 1, characterized in that: The skeleton layer (200) is made of metal material.

6. A multi-layer fully open steel plate according to claim 5, characterized in that: The plurality of shaping layers (100) are integrally formed on the skeleton layer (200).

7. A method for preparing a multi-layer fully open steel plate as claimed in any one of claims 1 to 6, characterized in that: The preparation method of the multi-layer fully open steel plate comprises: Preparing a skeleton layer (200), depositing the skeleton layer (200) by electroforming; A shaping layer (100) is prepared, and a plurality of the shaping layers (100) are grown on the skeleton layer (200) using an electroplating process.

8. The method for preparing a multi-layer fully open steel plate according to claim 7, characterized in that: The method for preparing the multi-layer fully open steel plate also includes: Before preparing the shaping layer (100), an ink-permeable pattern is laser engraved or photoetched on the skeleton layer (200).

9. The method for preparing a multi-layer fully open steel plate according to claim 7, characterized in that: The method for preparing the multi-layer fully open steel plate also includes: After the shaping layer (100) is prepared, the flatness of a number of the shaping layers (100) and the skeleton layer (200) is detected, and the opening widths of a number of the shaping patterns and the ink-permeable patterns are detected.

10. The method for preparing a multi-layer fully open steel plate according to claim 7, characterized in that: The method for preparing the multi-layer fully open steel plate also includes: After the shaping layer (100) is prepared, a printing test is performed on the multi-layer fully open steel plate to verify the fatigue resistance of the multi-layer fully open steel plate by simulating the movement of a scraper.

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