Preparation method of back glass prefabricated circuit

Abstract

The present invention discloses a method for preparing a prefabricated circuit on a back glass, comprising providing and cleaning a glass substrate; processing a first metal layer on a first surface of the glass substrate to obtain a first semi-finished product; performing pattern transfer on the first semi-finished product to form interconnecting bars and bus bars on the first metal layer to obtain a second semi-finished product; and electroplating the second semi-finished product to form conductive pads on the interconnecting bars and lead contacts on the bus bars, with the conductive pads and lead contacts being located on opposite sides of the first metal layer. The present invention enables prefabricating a circuit on the back glass, interconnecting with external cells via the conductive pads and with an external junction box via the lead contacts, thereby eliminating the need for ribbon welding.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaics, and in particular to a method for preparing a back glass prefabricated circuit. Background Art

[0002] In photovoltaic cell technology, back contact (BC) technology removes the grid lines from the front of the cell and places electrodes only on the back, reducing front-side obstruction and improving conversion efficiency. However, back contact cell modules are encapsulated using a ribbon welding process. When the back electrode of the cell is welded to the ribbon, the entire cell is heated. The localized high temperature (e.g., 200-300°C) at the ribbon connection point can cause thermal stress concentration in the cell, making it prone to warping after cooling and, in severe cases, even fragmentation. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for preparing a back glass prefabricated circuit, which can prefabricate the circuit on the back glass to achieve the purpose of eliminating the soldering process of the soldering ribbon.

[0004] An embodiment of the present invention provides a method for preparing a back glass prefabricated circuit, comprising:

[0005] Providing a glass substrate and cleaning the glass substrate;

[0006] Processing a first metal layer on the first surface of the glass substrate to obtain a first semi-finished product;

[0007] Performing pattern transfer on the first semi-finished product to form connected interconnecting bars and bus bars on the first metal layer to obtain a second semi-finished product;

[0008] The second semi-finished product is electroplated to form conductive pads on the interconnection bars and lead contacts on the bus bars, respectively. The conductive pads and the lead contacts are distributed on opposite sides of the first metal layer.

[0009] According to some embodiments of the present invention, the cleaning of the glass substrate includes:

[0010] performing ultrasonic cleaning on the glass substrate;

[0011] Rinse the glass substrate with deionized water so that the resistivity of the glass substrate is ≥18 MΩ·cm;

[0012] The washed glass substrate is dried at a temperature of 80-100° C. for 10-15 minutes.

[0013] According to some embodiments of the present invention, the glass substrate is provided with a through hole positioned to fit the lead-out contact, and the processing of the first metal layer on the first surface of the glass substrate further includes: plugging the through hole.

[0014] According to some embodiments of the present invention, before performing the electroplating treatment on the second semi-finished product, the process further includes:

[0015] The plugging material of the through hole is removed to expose the through hole.

[0016] According to some embodiments of the present invention, processing the first metal layer on the first surface of the glass substrate includes:

[0017] The first metal layer is processed on the first surface of the glass substrate by magnetron sputtering, and the power density of the magnetron sputtering is 3-5 W / cm 2 , the argon flow rate is 50~100sccm, and the vacuum degree is 5×10 -4 Pa.

[0018] According to some embodiments of the present invention, performing pattern transfer on the first semi-finished product to form interconnect bars and bus bars on the first metal layer to obtain a second semi-finished product includes:

[0019] Coating a photoresist on the surface of the first metal layer, and performing exposure and development processing on the photoresist to expose the area to be etched of the first metal layer;

[0020] The area to be etched is etched to form interconnection bars and bus bars on the first metal layer to obtain a second semi-finished product.

[0021] According to some embodiments of the present invention, the pattern transfer is performed on the first semi-finished product to form interconnect bars and bus bars on the first metal layer to obtain a second semi-finished product, and then the process further includes:

[0022] coating photoresist on the second semi-finished product and performing exposure and development processing to expose the bus bar;

[0023] The busbar is electroplated to increase the thickness of the busbar.

[0024] According to some embodiments of the present invention, the electroplating of the second semi-finished product to form conductive pads on the interconnecting bars and lead contacts on the bus bars includes:

[0025] Coating photoresist on the second semi-finished product and performing exposure and development processing to expose the area to be electroplated of the interconnection bar and the area to be electroplated of the bus bar;

[0026] Electroplating is performed on the areas to be electroplated of the interconnecting bars and the areas to be electroplated of the bus bars, and conductive pads are formed on the interconnecting bars and lead contacts are formed on the bus bars, respectively, to obtain a third semi-finished product.

[0027] According to some embodiments of the present invention, the electroplating of the interconnect bar and the bus bar to be electroplated may further include:

[0028] removing the photoresist on the third semi-finished product to obtain a fourth semi-finished product;

[0029] coating photoresist on the fourth semi-finished product and performing exposure and development processing to expose the lead-out contacts;

[0030] The lead-out contacts are electroplated to increase the thickness of the lead-out contacts.

[0031] According to some embodiments of the present invention, the electroplating of the second semi-finished product to form conductive pads on the interconnecting bars and lead contacts on the bus bars may further include:

[0032] A soldering flux is coated on the surface of the conductive pad to perform surface treatment.

[0033] The embodiments of the present invention have at least the following beneficial effects:

[0034] After the glass substrate is cleaned, the first metal layer is processed, and the pattern is transferred, connected interconnection bars and bus bars are processed on the first metal layer, and conductive pads are electroplated on the interconnection bars and lead contacts are electroplated on the bus bars. Circuits can be prefabricated on the back glass, interconnected with external battery cells through conductive pads, and interconnected with external junction boxes through lead contacts, thereby eliminating the soldering process of soldering ribbons.

[0035] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0037] Figure 1 Flowchart of the steps of the method for preparing the back glass prefabricated circuit according to an embodiment of the present invention;

[0038] Figure 2 Schematic diagram of the structure of the glass substrate and the first metal layer according to an embodiment of the present invention;

[0039] Figure 3 This is one of the structural schematic diagrams of the glass substrate, interconnection bars and bus bars according to an embodiment of the present invention;

[0040] Figure 4 This is a second structural diagram of a glass substrate, interconnecting bars, and bus bars according to an embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of the assembly structure of the back glass, battery cell and junction box according to an embodiment of the present invention;

[0042] Figure 6 is a schematic plan view of the back glass of an embodiment of the present invention;

[0043] Figure 7 This is the second schematic diagram of the assembly structure of the back glass, battery cell and junction box according to an embodiment of the present invention.

[0044] Reference numerals:

[0045] Back glass 100 , glass substrate 110 , first metal layer 111 , through-hole 112 , interconnection bar 120 , conductive pad 121 , bus bar 130 , lead contact 131 , junction box 200 , conductive contact 201 , battery cell 300 , conductive solder joint 301 . DETAILED DESCRIPTION

[0046] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0047] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0048] In the description of the present invention, "several" means one or more, "multiple" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, and "above," "below," and "within" are understood to include the number itself. The use of terms such as "first" and "second" is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0049] In the description of the present invention, unless otherwise clearly defined, words such as “setting”, “installation” and “connection” should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above words in the present invention based on the specific content of the technical solution.

[0050] Please refer to Figure 1 This embodiment discloses a method for preparing a back glass prefabricated circuit, including steps S100 to S400. It should be noted that the numbering of the steps in this embodiment is only for ease of review and understanding, and does not limit the order in which the steps are executed. The following details the contents of each step:

[0051] S100, providing a glass substrate 110, and cleaning the glass substrate 110;

[0052] For example, the glass substrate 110 can be a conventional substrate for photovoltaic cells to provide sufficient mechanical strength, improve compatibility with upstream raw materials, and reduce production costs. Cleaning the glass substrate 110 includes: ultrasonically cleaning the glass substrate 110; rinsing the glass substrate 110 with deionized water to achieve a resistivity of ≥18 MΩ·cm. This increases the resistance of the glass substrate 110 and reduces its conductivity, preventing short circuits from forming conductive connections in the prefabricated circuits; and drying the rinsed glass substrate 110 to remove residual moisture and organic solvents, improving the cleanliness and surface smoothness of the glass substrate, and enhancing adhesion with subsequent materials (such as the photoresist and first metal layer 111 described below). This ensures smooth processing during subsequent processing. Furthermore, drying eliminates internal stresses, improving the stability and reliability of the glass substrate. Considering that the glass substrate is prone to cracking or deformation due to thermal stress at high temperatures, the drying temperature is set to 80-100°C and the baking time is 10-15 minutes, which can avoid damage to the glass substrate 110 and avoid aging or performance degradation of the glass substrate 110.

[0053] S200, processing the first metal layer 111 on the first surface of the glass substrate 110 to obtain a first semi-finished product;

[0054] For example, please refer to Figure 2 Step S200 includes: processing the first metal layer 111 on the first surface of the glass substrate 110 by magnetron sputtering, and the power density of the magnetron sputtering is 3-5 W / cm 2, which can ensure the stability of the magnetron sputtering process and the uniformity of the first metal layer 111, while avoiding problems such as target overheating or insufficient sputtering rate during the magnetron sputtering process. Argon is used as the working gas in the magnetron sputtering process. The flow rate directly affects the density and stability of the plasma. Controlling the argon flow rate at 50-100 sccm (standard cubic centimeters per minute) can ensure that there is enough argon ionization to form plasma, thereby effectively bombarding the target and depositing a high-quality metal layer. In addition, the vacuum degree is configured to 5×10 - 4 Pa helps reduce the impact of impurity gases in the sputtering environment on the sputtering process, ensuring that the sputtered atoms or molecules are directly deposited on the surface of the glass substrate 110, thereby improving the purity and adhesion of the first metal layer 111. At the same time, a high vacuum level helps control the particle energy during the sputtering process and prevent defects in the first metal layer 111. By properly configuring the power density, argon gas flow rate, and vacuum level of the magnetron sputtering process, the efficiency of the magnetron sputtering process and the deposition quality of the first metal layer 111 can be improved.

[0055] S300 , performing pattern transfer on the first semi-finished product to form connected interconnection bars 120 and bus bars 130 on the first metal layer 111 to obtain a second semi-finished product;

[0056] For example, please refer to Figure 2 and Figure 3 Pattern transfer technology refers to sticking or coating a photosensitive film layer (such as photoresist) on the processed copper surface (such as the first metal layer 111), and transferring the circuit pattern on the film (such as the pattern of the interconnection bar 120 and the bus bar 130) to the copper surface under ultraviolet light to form an anti-corrosion mask layer. The copper surface not protected by the mask layer will be etched away during the chemical etching process. After the etching process, the anti-corrosion mask layer is removed to obtain the required bare copper circuit pattern.

[0057] In a specific application example, step S300 includes: coating a photoresist on the surface of the first metal layer 111, and exposing and developing the photoresist to expose the area to be etched of the first metal layer 111; etching the area to be etched to process the interconnection bar 120 and the bus bar 130 in the first metal layer 111 to obtain a second semi-finished product.

[0058] Illustratively, the first metal layer 111 is deposited on the surface of the glass substrate 110, and a photoresist is coated on the surface of the first metal layer 111 to shield the first metal layer 111. The photoresist is exposed and developed using a film to form a preset circuit pattern on the photoresist. After etching, the circuit pattern of the interconnection bar 120 and the bus bar 130 can be obtained, and the rest of the first metal layer 111 is etched away.

[0059] In some application examples, the interconnection bar 120 and the bus bar 130 may have the same thickness but different widths, thereby having different conductive capabilities; or, in other application examples, the thickness of the interconnection bar 120 and the bus bar 130 may be different. Then, after step S300, the following steps are further included: coating photoresist on the second semi-finished product and performing exposure and development treatment to expose the bus bar 130; and electroplating the bus bar 130 to increase the thickness of the bus bar 130.

[0060] Exemplarily, a photoresist is coated on the second semi-finished product. The photoresist covers the surface of the glass substrate 110 and the surface of the first metal layer 111. That is, the photoresist covers the interconnection bars 120 and the bus bars 130. The photoresist is exposed and developed to expose the bus bars 130 and cover the interconnection bars 120. During the electroplating process, the interconnection bars 120 are protected by the photoresist and no metal is deposited. In other words, only the exposed bus bars 130 are electroplated with metal, thereby increasing the thickness of the bus bars 130. After the circuit thickening process is completed, the photoresist is removed.

[0061] S400 , electroplating the second semi-finished product to form conductive pads 121 on the interconnection bar 120 and lead contacts 131 on the bus bar 130 , respectively. The conductive pads 121 and the lead contacts 131 are distributed on opposite sides of the first metal layer 111 .

[0062] For example, please refer to Figure 3 and Figure 4The thickness of the conductive pads 121 and the lead contacts 131 is different from that of the busbars 130, so the second semi-finished product needs to be electroplated to form the conductive pads 121 and the lead contacts 131. It is worth noting that the back glass 100 obtained in this embodiment is used in combination with the XBC cell 300. XBC cell technology is a back-contact solar cell technology. The "X" represents its ability to be combined with various technologies, such as TOPCon (tunneling oxide passivation contact) and HJT (heterojunction technology). It can be combined with TOPCon technology to form a TBC, or with HJT technology to form an HBC. XBC cells locate the PN junction and metal contacts on the back of the cell, while the front is covered with an anti-reflective passivation film. This prevents metal electrodes from blocking the front surface, maximizes the use of incident light, reduces optical losses, increases the effective power generation area, thereby achieving high conversion efficiency, and enhancing the appearance of the cell module. Therefore, the conductive pads 121 are all arranged on the first side of the first metal layer 111 to facilitate connection with the conductive solder joints 301 of the battery cells 300, and the lead contacts 131 of the busbars 130 are arranged on the second side of the first metal layer 111 to facilitate connection with the junction box 200, wherein the first side and the second side of the first metal layer 111 are opposite sides, such as the upper and lower sides.

[0063] Through the above solution, after the glass substrate 110 is cleaned, the first metal layer 111 is processed, and the pattern is transferred, connected interconnection bars 120 and bus bars 130 are processed on the first metal layer 111, and conductive pads 121 are electroplated on the interconnection bars 120 and lead contacts 131 are electroplated on the bus bars 130. Circuits can be prefabricated on the back glass 100, interconnected with external battery cells 300 through the conductive pads 121, and interconnected with external junction boxes 200 through the lead contacts 131, thereby achieving the purpose of eliminating the soldering process of soldering ribbons.

[0064] Please refer to Figure 4 、 Figure 5 、 Figure 6 and Figure 7During use, multiple cells 300 with conductive solder joints 301 are stacked on the back glass 100. The conductive solder joints 301 of the cells 300 correspond one-to-one with the conductive pads 121 on the back glass 100. Local alloying welding technology allows the conductive solder joints 301 and conductive pads 121 to be interconnected, thereby interconnecting different cells 300 through the interconnection bars 120, and integrating and transmitting current between different interconnection bars 120 through the busbars 130. This eliminates the need for soldering ribbons to connect different cells 300, eliminating the need for soldering ribbons, preventing warping or fragmentation of the cells 300 caused by soldering ribbons, and simplifying the manufacturing process, improving processing efficiency. In conventional processes, before the stacking assembly process, the individual busbars 130 need to be soldered to the soldering ribbons to interconnect the soldering ribbons and busbars 130. After the busbars 130 are connected, they extend to the surface of the back glass 100 to facilitate connection to the junction box 200. In this embodiment, the bus bar 130 is prefabricated on the glass substrate 110 , and the lead contacts 131 are electroplated on the bus bar 130 , which can be directly connected to the junction box 200 , thereby simplifying the assembly of the junction box 200 .

[0065] Please refer to Figure 6 and Figure 7 The interconnection bar 120 is divided into an N-type interconnection bar and a P-type interconnection bar. The N-type interconnection bar is used to connect the negative electrode of the battery cell 300. The N-type conductive pad 121 is provided on the N-type interconnection bar. Figure 6 The square pad shown on the left is a P-type interconnection bar used to connect the positive electrode of the battery cell 300. A P-type conductive pad 121 is provided on the P-type interconnection bar. Figure 6 The circular pads shown on the right. It should be noted that the shapes of the conductive pads 121 shown in the figure are for differentiation purposes only and do not represent the actual pad shapes. Interconnect bars 120 of the same type are connected to corresponding bus bars 130 to output electrical energy through the bus bars 130.

[0066] In some application examples, step S400 includes: coating photoresist on the second semi-finished product and performing exposure and development processing to expose the area to be electroplated of the interconnection bar 120 and the area to be electroplated of the bus bar 130; electroplating the area to be electroplated of the interconnection bar 120 and the area to be electroplated of the bus bar 130, and electroplating to form a conductive pad 121 on the interconnection bar 120 and a lead contact 131 on the bus bar 130, respectively, to obtain a third semi-finished product.

[0067] For example, the conductive pads 121 can be processed in the area to be plated of the interconnection bar 120 , and the lead contacts 131 can be processed in the area to be plated of the bus bar 130 through electroplating.

[0068] In some application examples, the thickness of the conductive pad 121 is the same as that of the lead-out contact 131, or, in other application examples, the thickness of the lead-out contact 131 is greater than the thickness of the conductive pad 121. Then, the area to be plated of the interconnection bar 120 and the area to be plated of the bus bar 130 are electroplated, and then the following steps are included: removing the photoresist on the third semi-finished product to obtain a fourth semi-finished product; coating the fourth semi-finished product with photoresist and performing exposure and development treatment to expose the lead-out contact 131; and electroplating the lead-out contact 131 to increase the thickness of the lead-out contact 131.

[0069] After step S400 , the following step further includes: coating flux on the surface of the conductive pad 121 to perform surface treatment.

[0070] For example, conventional battery cell 300 welding uses an infrared heating process to heat the battery cell 300 as a whole, so that the soldering ribbon on the battery cell 300 is heated, thereby connecting to the main grid line of the battery cell 300. This is prone to uneven stress problems, which leads to the phenomenon of warping of the battery cell 300 after welding. In this embodiment, flux is coated on the surface of the conductive pad 121 to enhance the welding performance of the conductive pad 121. After the battery cell 300 is stacked with the back glass 100, the position of the conductive pad 121 is adapted to the position of the conductive solder joint 301 of the battery cell 300. The conductive pad 121 and the conductive solder joint 301 are locally alloyed and welded based on the pulse hot pressing technology. Pulse hot pressing welding achieves the purpose of molten welding by loading a certain pulse voltage on the hot pressing head to heat the hot pressing head and heat up the object connected to the hot pressing head. Pulse hot pressing welding performs local heating at the position where the back glass 100 and the conductive pad 121 are matched, and radiates heat to the conductive solder joint 301 of the battery cell 300, so that the conductive pad 121 is in a hot-melt state and connected to the conductive solder joint 301. There is no need to weld the battery cell 300, which can greatly reduce the stress problem of the battery cell 300. Since the solder strip is eliminated and the battery cell 300 is directly connected through the interconnection strip 120, ultra-low stress is achieved, which can avoid local stress concentration and prevent the battery cell 300 from warping or fragmenting after cooling, thereby ensuring the reliability of the battery cell 300.

[0071] For some application examples, see Figure 2 and Figure 3 The glass substrate 110 is provided with a through hole 112 whose position is adapted to the lead-out contact 131 . Before step S200 , the process further includes: performing a plugging process on the through hole 112 .

[0072] For example, the junction box 200 is typically installed on the back side of the rear glass 100, that is, the junction box 200 and the bus bar 130 are distributed on two different surfaces of the glass substrate 110. In order to achieve the connection between the junction box 200 and the bus bar 130, it is necessary to open a through hole 112 in the glass substrate 110 to allow the conductive contacts 201 of the junction box 200 to pass through the glass substrate 110 and thus connect to the bus bar 130. The diameter of the through hole 112 is 1 to 1.5 mm. In order to allow the bus bar 130 to cover the through hole 112, the through hole 112 needs to be plugged before magnetron sputtering so that the location of the through hole 112 can be covered by the first metal layer 111. The plugging material can be EVA material, which is the abbreviation of polyethylene vinylacetate, a polyethylene-polyvinyl acetate copolymer.

[0073] Please refer to Figure 3 and Figure 4 Before step S400 , the method further includes: removing the plugging material of the through hole 112 to expose the through hole 112 .

[0074] For example, after pattern transfer, busbar 130 is processed. Busbar 130 can cover through-hole 112. Lead contacts 131 need to be electroplated in through-hole 112 to facilitate connection to junction box 200. Therefore, before electroplating, the plugging material of through-hole 112 needs to be removed to expose through-hole 112. The removal method is selected based on the plugging material, and laser etching or chemical etching can be used.

[0075] In other application examples, the glass substrate 110 provided in step S100 may be made of ordinary glass, and the through holes 112 may not be provided on the glass substrate 110. After the bus bars are processed by pattern transfer in step S200, the through holes 112 are provided on the glass substrate 110 using laser depth-controlled cutting technology.

[0076] Please refer to the following Figures 2 to 7 , a specific application example is used to describe the method for preparing the back glass prefabricated circuit according to an embodiment of the present invention:

[0077] Providing a glass substrate 110 and cleaning the glass substrate 110, wherein a through hole 112 is formed on the glass substrate 110;

[0078] Performing plugging treatment on the through hole 112;

[0079] Processing a first metal layer 111 on a first surface of a glass substrate 110 by magnetron sputtering to obtain a first semi-finished product;

[0080] A first photoresist is coated on the surface of the first metal layer 111, and the first photoresist is exposed and developed to expose the area to be etched of the first metal layer 111; the area to be etched is etched to form the interconnection bar 120 and the bus bar 130 on the first metal layer 111, thereby obtaining a second semi-finished product;

[0081] Removing the first photoresist from the second semi-finished product, coating the second photoresist on the second semi-finished product, and performing exposure and development processing to expose the busbar 130; performing electroplating processing on the busbar 130 to increase the thickness of the busbar 130;

[0082] removing the plugging material of the through hole 112 to expose the through hole 112 ;

[0083] The second photoresist is removed, and a third photoresist is applied to the second semi-finished product, followed by exposure and development, to expose the areas to be plated of the interconnection bar 120 and the bus bar 130; the areas to be plated of the interconnection bar 120 and the bus bar 130 are electroplated to form conductive pads 121 on the interconnection bar 120 and lead contacts 131 on the bus bar 130, respectively, to obtain a third semi-finished product;

[0084] removing the third photoresist on the third semi-finished product to obtain a fourth semi-finished product; coating the fourth photoresist on the fourth semi-finished product and performing exposure and development processing to expose the lead-out contact 131; and electroplating the lead-out contact 131 to increase the thickness of the lead-out contact 131;

[0085] A soldering flux is applied to the surface of the conductive pad 121 to perform surface treatment.

[0086] Through the above solution, after the glass substrate 110 is cleaned, the first metal layer 111 is processed, and the pattern is transferred, connected interconnection bars 120 and bus bars 130 are processed on the first metal layer 111, and conductive pads 121 are electroplated on the interconnection bars 120 and lead contacts 131 are electroplated on the bus bars 130. Circuits can be prefabricated on the back glass 100, interconnected with external battery cells 300 through the conductive pads 121, and interconnected with external junction boxes 200 through the lead contacts 131, thereby achieving the purpose of eliminating the soldering process of soldering ribbons.

[0087] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. A method for preparing a back glass prefabricated circuit, characterized in that: include: Providing a glass substrate (110), and cleaning the glass substrate (110); Processing a first metal layer (111) on a first surface of the glass substrate (110) to obtain a first semi-finished product; Performing pattern transfer on the first semi-finished product to form connected interconnection bars (120) and bus bars (130) on the first metal layer (111), thereby obtaining a second semi-finished product; Performing electroplating on the second semi-finished product, respectively electroplating to form conductive pads (121) on the interconnection bar (120) and to form lead-out contacts (131) on the bus bar (130), wherein the conductive pads (121) and the lead-out contacts (131) are distributed on opposite sides of the first metal layer (111); The electroplating treatment of the second semi-finished product, respectively electroplating to form a conductive pad (121) on the interconnection bar (120) and electroplating to form a lead contact (131) on the bus bar (130), comprises: Coating photoresist on the second semi-finished product and performing exposure and development processing to expose the area to be electroplated of the interconnection bar (120) and the area to be electroplated of the bus bar (130); Electroplating the area to be electroplated of the interconnection bar (120) and the area to be electroplated of the bus bar (130), respectively forming a conductive pad (121) on the interconnection bar (120) and a lead contact (131) on the bus bar (130), to obtain a third semi-finished product; removing the photoresist on the third semi-finished product to obtain a fourth semi-finished product; Coating photoresist on the fourth semi-finished product and performing exposure and development processing to expose the lead-out contact (131); The lead-out contact (131) is electroplated to increase the thickness of the lead-out contact (131).

2. The method for preparing a back glass prefabricated circuit according to claim 1, characterized in that: The cleaning of the glass substrate (110) comprises: Performing ultrasonic cleaning on the glass substrate (110); The glass substrate (110) is rinsed with deionized water so that the resistivity of the glass substrate (110) is ≥18 MΩ·cm; The washed glass substrate (110) is dried at a temperature of 80-100° C. and a baking time of 10-15 minutes.

3. The method for preparing a back glass prefabricated circuit according to claim 1, wherein: The glass substrate (110) is provided with a through hole (112) whose position is adapted to the lead contact (131). Before processing the first metal layer (111) on the first surface of the glass substrate (110), the method further includes: plugging the through hole (112).

4. The method for preparing a back glass prefabricated circuit according to claim 3, wherein: The electroplating treatment of the second semi-finished product further comprises: The plugging material of the through hole (112) is removed to expose the through hole (112).

5. The method for preparing a back glass prefabricated circuit according to claim 1, wherein: The step of processing the first metal layer (111) on the first surface of the glass substrate (110) comprises: A first metal layer (111) is processed on the first surface of the glass substrate (110) by magnetron sputtering, wherein the power density of the magnetron sputtering is 3-5 W / cm 2 , the argon flow rate is 50~100sccm, and the vacuum degree is 5×10 -4 Pa.

6. The method for preparing a back glass prefabricated circuit according to claim 1, wherein: The pattern transfer is performed on the first semi-finished product to form interconnection bars (120) and bus bars (130) on the first metal layer (111) to obtain a second semi-finished product, comprising: Coating a photoresist on the surface of the first metal layer (111), and performing exposure and development processing on the photoresist to expose the area to be etched of the first metal layer (111); The area to be etched is etched to form interconnection bars (120) and bus bars (130) on the first metal layer (111), thereby obtaining a second semi-finished product.

7. The method for preparing a back glass prefabricated circuit according to claim 1 or 6, characterized in that: The first semi-finished product is subjected to pattern transfer to form interconnection bars (120) and bus bars (130) on the first metal layer (111) to obtain a second semi-finished product, and then further comprises: coating photoresist on the second semi-finished product and performing exposure and development processing to expose the busbar (130); The bus bar (130) is subjected to an electroplating process to increase the thickness of the bus bar (130).

8. The method for preparing a back glass prefabricated circuit according to any one of claims 1 to 6, characterized in that: The second semi-finished product is subjected to electroplating treatment to form conductive pads (121) on the interconnection bar (120) and lead contacts (131) on the bus bar (130), and then further comprises: A soldering flux is applied to the surface of the conductive pad (121) to perform surface treatment.

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