Main-grid-free assembly prepared by graphical carrier film

Abstract

The utility model discloses a main-grid-free assembly prepared from a graphical bearing film, which structurally comprises transparent glass, an upper-layer adhesive film, an upper-layer graphical bearing film, an OBB battery string, a lower-layer graphical bearing film, a lower-layer adhesive film and a back plate in sequence from a light receiving surface to an outer surface, the OBB battery string is composed of a plurality of main-grid-free battery pieces arranged in an array mode, the adjacent battery pieces of the OBB battery string are connected in parallel through a plurality of sets of low-temperature welding strips, and the upper-layer graphical bearing film and the lower-layer graphical bearing film conduct graphical cutting on blocky bearing films in a laser cutting mode or an automatic cutter mode. And the cut patterns are pasted and fixed on the front and back surfaces of the OBB battery string in a #-shaped manner. The low-temperature thin welding strip is wrapped by the patterned bearing film through infrared low-temperature hot welding and is pasted and fixed on the front and back surfaces of the battery string, so that the connection between the welding strip and the battery piece is reinforced, the delamination phenomenon in a full-film-covering state is avoided, and the reliability verification of the module is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of solar photovoltaics, in particular to a main grid-free component prepared by a patterned carrier film. Background Art

[0002] As the improvement of the power generation efficiency of silicon-based solar cells has reached a certain bottleneck, finding ways to reduce costs has become a goal for major companies for a long time to come. Generally, the main grid of photovoltaic cells usually uses silver paste, which is very expensive. Therefore, it is crucial to reduce the consumption of silver paste. Based on the perspective of reducing the absolute value of silver paste usage and seeking silver substitutes, more and more researchers are focusing on the research and development of busbar-less batteries. Busbar-less batteries eliminate the original busbar silver paste and use welding ribbons to collect fine grid currents and achieve battery interconnection. In the existing technology, dispensing or lamination methods are usually used. However, the lamination method usually involves covering the entire mask material on the battery cell and then fixing it through other processes. This treatment will prevent the battery cell from having good contact with the adhesive film. During lamination, the battery string will have a large offset and there is a risk of parallel connection, and the subsequent reliability verification will also have a certain impact.

[0003] To this end, the applicant has carried out certain graphic processing on the mask material so that part of the battery cell is exposed and in full contact with the film, thereby solving the risk of battery strings being offset and connected in parallel during the lamination process and improving the reliability verification of the components. Utility Model Content

[0004] In response to the above problems, the present invention provides a main-grid-free component prepared with a patterned carrier film that strengthens the connection between the welding strip and the battery cell, avoids delamination in the full-film state, and improves the reliability verification of the component.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a main-grid-free component prepared by a patterned carrier film, the main-grid-free component structure is transparent glass, an upper adhesive film, an upper patterned carrier film, an OBB battery string, a lower patterned carrier film, a lower adhesive film, and a backplane from the light-receiving surface to the outer surface. The OBB battery string is composed of a plurality of array-arranged main-grid-free battery cells. The adjacent battery cells of the OBB battery string are connected in parallel by several groups of low-temperature soldering tapes. The two ends of the low-temperature soldering tapes are respectively connected to the light-receiving surface of one battery cell and the backlight surface of the next battery cell. The low-temperature soldering tapes at both ends of the OBB battery string are led outward. The upper patterned carrier film and the lower patterned carrier film are patterned by laser cutting or automatic cutting to cut the block carrier film. The cut pattern is in the shape of a "well". The upper patterned carrier film and the lower patterned carrier film are pasted and fixed to the front and back sides of the OBB battery string.

[0006] Furthermore, the upper patterned carrier film and the lower patterned carrier film are both composed of a light absorbing layer, an ultraviolet light conversion layer and an adhesive layer formed by multi-layer co-extrusion.

[0007] Furthermore, the thickness of the upper patterned carrier film and the lower patterned carrier film is set to 0.05-0.5 mm.

[0008] Furthermore, the overall length and width of the upper patterned carrier film and the lower patterned carrier film are both less than or equal to the length and width of half a battery cell, the horizontal line width is set to 1-6 mm, the number of horizontal lines is set according to the number of welding strips on the single battery cell, and the length is set to be less than or equal to the width of half a battery cell, the number of vertical lines is between 2-6, the width is set to 5-30 mm, and the length is set to be less than or equal to the length of half a battery cell.

[0009] Furthermore, the OBB battery string uses thickened and widened secondary grid lines in the welding ribbon area, or thinned main grid lines to the same width as the fine grid lines, so that the low-temperature welding ribbon is welded to the battery cell, and the welding ribbon coating on the low-temperature welding ribbon forms an alloy with the secondary grid lines of the battery cell.

[0010] Furthermore, the diameter of the low-temperature soldering tape is set at 0.15mm-0.35mm.

[0011] From the above description of the structure of the utility model, it can be seen that compared with the prior art, the utility model has the following advantages:

[0012] 1. Use a graphic carrier film to wrap the low-temperature thin solder ribbon through infrared low-temperature heat welding and stick it to the front and back of the battery string. This can effectively strengthen the connection between the solder ribbon and the battery cell, protect the solder ribbon and the battery cell secondary grid line from alloying, so that the current of the series battery string can flow well, and can also isolate the contact between the solder ribbon and the adhesive film, preventing the adhesive film from penetrating into the solder ribbon and battery cell in a molten state, which directly leads to the phenomenon of filling reduction.

[0013] 2. The patterned carrier film has incisions at corresponding positions, so that most of the battery cells can be in good contact with the adhesive film, preventing the battery string from shifting due to the melt flow of the film during the lamination process, and avoiding the delamination phenomenon after lamination in the full-film state, thereby further improving the reliability verification of the component. At the same time, the transmittance of incident light to the battery will be reduced to a certain extent, and the transmittance will be higher than that of full-film. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0015] Figure 1This is a cross-sectional view of a busbar-free assembly prepared using a patterned carrier film according to the present invention;

[0016] Figure 2 This is a structural diagram of the upper graphic carrier film covering the OBB battery string of the utility model. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] Example

[0019] refer to Figure 1 、 Figure 2 , a main-grid-free component prepared by a patterned carrier film, the main-grid-free component structure from the light-receiving surface to the outer surface is transparent glass 4, upper adhesive film 3, upper patterned carrier film 2, OBB battery string 1, lower patterned carrier film 5, lower adhesive film 6, backplane 7, the OBB battery string 1 is composed of a plurality of array-arranged main-grid-free battery cells, the adjacent battery cells of the OBB battery string are connected in parallel by several groups of low-temperature welding strips 8, the battery cell is 182mm long and 91mm wide, the two ends of the low-temperature welding strip 8 are respectively connected to the light-receiving surface of one battery cell and the next The backlight surface of the battery cell is connected, and the low-temperature welding strips 8 at both ends of the OBB battery string 1 are led outward. The upper patterned carrier film 2 and the lower patterned carrier film 5 are patterned by laser cutting or automatic cutting. The block carrier film is cut out, and the pattern after cutting is in the shape of a "well", with 20 lines, a length of 88mm, a width of 3mm, and a gap of 8.65mm. The number of vertical lines is set to 2, with a length of 180mm, a width of 15mm, and a gap of 30.3mm. The upper patterned carrier film 2 and the lower patterned carrier film 5 are glued and fixed to the front and back of the OBB battery string 1.

[0020] The upper patterned carrier film 2 and the lower patterned carrier film 5 are both composed of a light absorption layer, an ultraviolet light conversion layer and an adhesive layer formed by multi-layer co-extrusion. The film thickness of the upper patterned carrier film 2 and the lower patterned carrier film 5 is set to 0.2 mm.

[0021] The OBB battery string 1 uses the auxiliary grid lines in the welding ribbon area to be thickened and widened, or the main grid lines to be thinned, the same as the width of the fine grid lines, so that the low-temperature welding ribbon is welded to the battery cell, and the welding ribbon coating on the low-temperature welding ribbon 8 forms an alloy with the auxiliary grid lines of the battery cell. The diameter of the low-temperature welding ribbon 8 is set at 0.25mm.

[0022] The method for preparing a main-grid-free component prepared by the patterned carrier film is as follows: first, the patterned carrier film is patterned and cut out of a block carrier film by laser cutting or an automatic cutter, and the cut pattern is in the shape of a "well", and then the patterned carrier film is wrapped with a low-temperature fine welding tape by infrared low-temperature heat welding and pasted and fixed on the front and back of the OBB battery string, and the patterned carrier film is affixed to the upper and lower sides of the OBB battery string on the laminating platform, and then the laminated OBB battery string and the pressing tool are transported as a whole to the infrared heating zone, and by controlling the heating temperature at about 120°C, the patterned carrier film shrinks and melts due to heat and is pasted together with the OBB battery string, and finally, from the light-receiving surface to the outer surface, transparent glass, upper adhesive film, upper patterned carrier film, OBB battery string, lower patterned carrier film, lower adhesive film, and backplane enter the laminator for lamination.

[0023] The patterned carrier film is composed of bio-based resin, polyethylene, ethylene-vinyl acetate copolymer and terpene resin.

[0024] The low-temperature solder strip coating is made of any one or more combinations of tin-lead-bismuth, tin-lead-bismuth-silver, tin-bismuth-silver, and tin-lead materials, and has a melting point below 150° C.

[0025] The utility model uses a graphic carrier film to wrap the low-temperature thin solder strip through infrared low-temperature heat welding and stick it to the front and back of the battery string. It can effectively strengthen the connection between the solder strip and the battery cell, protect the solder strip and the battery cell secondary grid line from alloying, so that the current of the series battery string can flow well, and can also isolate the contact between the solder strip and the adhesive film, preventing the adhesive film from penetrating into the solder strip and the battery cell in a molten state, which directly causes the filling to decrease. The graphic carrier film has incisions at corresponding positions, so that most of the battery cell can be in good contact with the adhesive film, preventing the battery string from being displaced due to the melt flow of the adhesive film during the lamination process, avoiding the delamination phenomenon after lamination in a fully covered state, thereby further improving the reliability verification of the component. At the same time, the transmittance of incident light to the battery will be reduced to a certain extent, and the transmittance will be higher than that of a fully covered film.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A busbar-less component prepared using a patterned carrier film, characterized in that: The main grid-free component structure is transparent glass, upper adhesive film, upper graphic carrier film, OBB battery string, lower graphic carrier film, lower adhesive film, and backplane from the light-receiving surface to the outer surface. The OBB battery string is composed of a plurality of battery cells arranged in an array without main grids. The adjacent battery cells of the OBB battery string are connected in parallel by several groups of low-temperature welding tapes. The two ends of the low-temperature welding tapes are respectively connected to the light-receiving surface of one battery cell and the backlight surface of the next battery cell. The low-temperature welding tapes at both ends of the OBB battery string are led outward. The upper graphic carrier film and the lower graphic carrier film are graphic-cut by laser cutting or automatic cutting. The pattern after cutting is in the shape of a "well". The upper graphic carrier film and the lower graphic carrier film are pasted and fixed to the front and back sides of the OBB battery string.

2. The busbar-free assembly prepared by the patterned carrier film according to claim 1, characterized in that: The upper patterned carrier film and the lower patterned carrier film are both composed of a light absorbing layer, an ultraviolet light conversion layer and an adhesive layer formed by multi-layer co-extrusion.

3. The busbar-free assembly prepared by the patterned carrier film according to claim 1, characterized in that: The thickness of the upper patterned carrier film and the lower patterned carrier film is set to 0.05-0.5 mm.

4. The busbar-free assembly prepared by the patterned carrier film according to claim 1, characterized in that: The overall length and width of the upper patterned carrier film and the lower patterned carrier film are both less than or equal to the length and width of half a battery cell. The horizontal line width is set to 1-6 mm, the number of horizontal lines is set according to the number of welding strips on the single battery cell, and the length is set to be less than or equal to the width of half a battery cell. The number of vertical lines is between 2-6, the width is set to 5-30 mm, and the length is set to be less than or equal to the length of half a battery cell.

5. The busbar-free assembly prepared by using a patterned carrier film according to claim 1, characterized in that: The OBB battery string uses the same width of the auxiliary grid lines and main grid lines in the welding ribbon area, so that the low-temperature welding ribbon is welded to the battery cell, and the welding ribbon coating on the low-temperature welding ribbon forms an alloy with the auxiliary grid lines of the battery cell.

6. The busbar-free assembly prepared by the patterned carrier film according to claim 1, characterized in that: The diameter of the low-temperature soldering tape is set at 0.15mm-0.35mm.

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