Pattern marking method for surface of solar cell

Abstract

The invention relates to the field of pattern marking, in particular to a pattern marking method for the surface of a solar cell, which comprises the following steps of: designing a composite pattern and accurately positioning the solar cell; the solar cell is preprocessed; the designed composite pattern is imported into printing equipment, printing parameters are adjusted, and pattern printing is conducted through printing ink; and carrying out curing treatment on the printed pattern. Through a printing or ink-jet printing technology, high-precision and high-definition graph printing is realized on a solar cell or assembly, and an efficient and lossless product tracing, anti-counterfeiting and fault diagnosis scheme is provided by combining a microscope and an ultraviolet light detection technology; and the method has important significance for promoting intelligent and fine management of the solar energy industry.

Description

Technical Field

[0001] The invention relates to the field of graphic marking, in particular to a graphic marking method for the surface of a solar cell. Background Art

[0002] With the rapid development of the solar energy industry, the production of solar cells and modules has increased dramatically. The demand for quality monitoring, traceability and anti-counterfeiting of solar cells and modules has become increasingly urgent, which requires marking of solar cells and modules.

[0003] Traditional marking methods such as etching and spraying have problems such as high cost, low efficiency, and easy wear, and cannot meet people's needs. Summary of the Invention

[0004] The present invention proposes an innovative solution, which is to use printing or inkjet printing technology to accurately print specific graphics containing identity information, production batch, anti-counterfeiting patterns, etc. on the surface of solar cells without affecting their performance, and use microscopes or ultraviolet light to perform efficient and non-destructive testing, thereby achieving comprehensive management of solar products.

[0005] The present invention provides the following technical solutions:

[0006] A method for pattern marking on the surface of a solar cell comprises the following steps:

[0007] Design composite graphics and precisely position solar cells to ensure the accuracy of graphic printing positions;

[0008] Pre-treat the solar cell to ensure good adhesion between the subsequent ink and the solar cell;

[0009] Import the designed composite graphics into the printing device, adjust the printing parameters and print the graphics using ink;

[0010] The printed graphics are cured to enhance the adhesion and durability of the ink. The adhesion of the ink after curing is not less than 4B.

[0011] As a further solution of the present invention: the method for marking the graphic on the surface of a solar cell further includes detecting the solidified graphic, recording data and performing software analysis to achieve rapid identification and tracing of product information.

[0012] As a further solution of the present invention: the detection includes at least one of high-resolution microscope detection, ultraviolet light detection and infrared reflection detection. The high-resolution microscope detection can observe the edge clarity, integrity and ink adhesion of the pattern under 200-1000 times magnification. The ultraviolet light detection uses an ultraviolet light source to illuminate the surface of the solar cell and observe the luminescence or color change effect of the pattern under ultraviolet light to verify its authenticity and integrity. For example, the fluorescence characteristics under 365nm or 254nm wavelength excitation are observed, and the luminescence intensity is not less than 100cd / m 2 The infrared reflection test is carried out in the 850-1550nm band, and the reflectivity difference is not less than 15% to be qualified.

[0013] As a further solution of the present invention: printing adopts screen printing or inkjet printing technology.

[0014] As a further solution of the present invention: screen printing uses a 200-500 mesh screen, a printing thickness of 5-50μm, the pattern coverage area accounts for 0.1-10% of the surface area of ​​the solar cell, and inkjet printing uses a piezoelectric nozzle no larger than 10pL, with a positioning accuracy of ±25μm.

[0015] As a further solution of the present invention: the ink adopts a weather-resistant ink material, the ultraviolet ray tolerance wavelength range of which is 200-400nm, the high temperature tolerance threshold is not less than 150°C, and the humidity tolerance range is 20-98%RH.

[0016] As a further solution of the present invention: the pretreatment of solar cells includes cleaning treatment, which is to remove dust, oil and other impurities on the surface of solar cells or components to ensure ink adhesion. Furthermore, if necessary, surface modification treatment can be performed. Surface modification treatment is only required for specific materials, such as plasma treatment, chemical etching, etc., to improve ink adhesion.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention uses printing or inkjet printing technology to achieve high-precision and high-definition graphic printing on solar cell panels or modules. Combined with microscopy and ultraviolet light detection technology, it provides an efficient and non-destructive product traceability, anti-counterfeiting and fault diagnosis solution, which is of great significance for promoting intelligent and refined management of the solar energy industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the printing result of Example 1.

[0020] Figure 2 This is the printing result of Example 2.

[0021] Figure 3This is the detection image of Example 1. DETAILED DESCRIPTION

[0022] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0023] The ink needs to be weather-resistant, transparent and conductive, detectable and have good adhesion. Weather resistance: Select inks with excellent resistance to UV rays, high temperatures and humidity to ensure the long-term stability of the marking in harsh outdoor environments. Transparency and conductivity: For areas where the transmittance or conductivity of solar cells needs to be maintained, use high-transparency or special conductive inks to avoid affecting the performance of the battery. Detectability: The graphics designed by the ink can be detected under an electron microscope or the ink should contain components that can emit light or produce special color changes at specific wavelengths (such as ultraviolet light) to facilitate detection and identification. Adhesion: Ensure that the ink has good adhesion to the surface of the solar cell to prevent it from falling off during use. For example, the ink includes a matrix resin, a functional filler and a conductive component. The matrix resin is made of acrylate or epoxy-modified polyurethane, accounting for 60-80wt% of the ink. The functional filler is a rare earth-doped aluminate phosphor (SrAl2O4:Eu,Dy) or quantum dots (CdSe / ZnS) with a particle size not greater than 1μm, accounting for 5-15wt% of the ink. The conductive component is silver nanowires (diameter not greater than 100nm, aspect ratio not less than 50) or ITO nanoparticles, accounting for 0-20wt% of the ink. The combination of rare earth phosphor and conductive component realizes the dual functions of "detectability and electrical compatibility".

[0024] Printing is done using either screen printing or inkjet printing. Screen printing can be done using conventional high-speed screen printers used in the solar industry, with a 200-500 mesh screen. The printed pattern thickness should be between 5-50 microns, with the pattern covering 0.1-10% of the solar cell area. The inkjet printer uses a high-precision nozzle, calibrated using software to ensure uniform ink delivery and precise positioning. Print speed and nozzle pressure are optimized to minimize blurring and bleeding during printing. The number of print layers is then appropriately determined based on the pattern complexity and ink characteristics to achieve optimal visual quality and durability.

[0025] Graphic design should be based on product characteristics and requirements, resulting in a composite graphic that includes elements such as a QR code, barcode, and anti-counterfeiting patterns. For example, the graphic should include a machine-readable coding layer and a visual anti-counterfeiting layer. The machine-readable coding layer should use a QR code or DataMatrix code with a minimum cell size of no less than 100μm. Machine vision technology should then be used to precisely position the solar cell before printing to ensure the accuracy of the graphic's print position. The graphic should be located within a circular marking band on the backside field of the solar cell, 1-3mm from the edge, and with a line width of 50-200μm, ensuring a clear understanding of the graphic's location.

[0026] When curing the graphics, UV curing with a wavelength of 200-420nm and an energy density of 100-10000mJ / cm 2 The adhesion of the cured ink reaches ASTM D3359 standard 4B or above.

[0027] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0028] Example 1 (screen printing scheme):

[0029] Materials preparation:

[0030] Cell: PERC monocrystalline silicon cell (size 156×156mm),

[0031] Ink: Transparent UV curing ink ( OE-6630), adding 10wt% SrAl2O4:Eu,Dy phosphor,

[0032] Screen: 350 mesh stainless steel screen, pattern is 1.5×1.5mm Data Matrix code.

[0033] Process parameters:

[0034] Printing pressure: 0.3MPa,

[0035] Off-grid distance: 1.2mm,

[0036] Curing conditions: 385nm UVLED, energy density 1500mJ / cm 2 , operate according to the method of the present invention, the results are shown in Figure 1 and Figure 3 .

[0037] Test results:

[0038] Adhesion test: 5B grade (tape method),

[0039] UV response: emits 520nm green light under 365nm excitation, see Figure 3, brightness up to 350cd / m 2 ,

[0040] Impact on battery efficiency: Δη<0.05% (IEC 60904-3 standard test).

[0041] Example 2 (inkjet printing scheme):

[0042] Device configuration:

[0043] Industrial inkjet printer (Fuji Dimatix DMP-2850),

[0044] Printhead: 10pL ink droplet, 256 nozzle array,

[0045] Positioning system: Basler ace series CMOS camera (5MP),

[0046] Printing process:

[0047] Graphic design: including invisible anti-counterfeiting logo (line width 80μm) and clear code batch number,

[0048] Print resolution: 600×600dpi,

[0049] Number of layers: 2 reciprocating prints, operate according to the method of the present invention, the results are shown in Figure 2 .

[0050] Performance Verification:

[0051] Weather resistance: After passing the 2000-hour aging test according to IEC 61215 standard, the graphic readability remains 100%.

[0052] Detection speed: The online detection system can process up to 1,200 pieces per hour.

[0053] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for pattern marking on the surface of a solar cell, characterized in that: The following steps are involved: Design composite graphics and precisely position solar cells; Pre-processing of solar cells; Import the designed composite graphics into the printing device, adjust the printing parameters and print the graphics using ink; Solidify the printed graphics.

2. The method for pattern marking on the surface of a solar cell according to claim 1, characterized in that: It also includes testing, data recording and software analysis of the solidified graphics.

3. The method for pattern marking on the surface of a solar cell according to claim 2, characterized in that: The detection includes at least one of high-resolution microscopy detection, ultraviolet light detection, and infrared reflectance detection.

4. The method for pattern marking on the surface of a solar cell according to claim 1, wherein: Printing is done using screen printing or inkjet printing technology.

5. The method for pattern marking on the surface of a solar cell according to claim 4, characterized in that: Screen printing uses a 200-500 mesh screen, a printing thickness of 5-50 μm, and a pattern coverage area of ​​0.1-10% of the surface area of ​​the solar cell. Inkjet printing uses a piezoelectric nozzle no larger than 10 pL.

6. The method for pattern marking on the surface of a solar cell according to claim 1 or 2, characterized in that: The ink is made of weather-resistant ink material, and its ultraviolet tolerance wavelength range is 200-400nm, the high temperature tolerance threshold is not less than 150°C, and the humidity tolerance range is 20-98%RH.

7. The method for pattern marking on the surface of a solar cell according to claim 1, wherein: The pretreatment of the solar cell includes at least one of a cleaning treatment and a surface modification treatment.

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