Manufacturing method of back contact photovoltaic module and back contact photovoltaic module

Abstract

The invention provides a manufacturing method of a back contact photovoltaic module and the back contact photovoltaic module, and the method comprises the steps: enabling a probe to be loaded on the positive and negative electrodes of a metal conductive layer for electrifying when a conductive backboard of a photovoltaic cell is manufactured; forming an access of a metal conductive layer positive electrode, conductive adhesive, a battery piece positive electrode, a battery piece negative electrode, conductive adhesive and a metal conductive foil negative electrode; and in the path, the conductive adhesive generates the maximum heat in several layers of materials, the conductive adhesive is cured in the heating process, the battery piece is adhered to the metal conductive foil, and the position of the battery piece is fixed. According to the manufacturing method of the back contact photovoltaic module provided by the invention, the conductive adhesive of the battery is cured by electrifying the positive electrode and the negative electrode of the semi-finished product of the module, so that the position of the battery piece is fixed. And the original halogen lamp heating process is replaced, so that the energy consumption is reduced, the takt time is shortened, the production yield is improved, and cost reduction and efficiency improvement are realized.

Description

Technical Field

[0001] This invention belongs to the field of solar cell manufacturing technology, specifically relating to a photovoltaic solar cell module and its manufacturing method. Background Technology

[0002] Back-contact (BC) photovoltaic solar cells are increasingly popular due to their high conversion efficiency and aesthetic appeal. However, traditional ribbon-type back-contact solar cells, where the ribbon is only welded to the back of the crystalline silicon cell, experience significant welding stress, leading to cell warping. Therefore, traditional ribbon-type back-contact solar cells face considerable difficulties in manufacturing, resulting in low yields and high costs. This also limits the widespread application of BC photovoltaic modules.

[0003] A conductive backsheet technology for BC photovoltaic modules, replacing traditional solder strips, can overcome the problem of cell warping caused by solder strip welding and has significant potential for widespread application. The specific construction process is as follows: 1. A patterned conductive metal layer (PEC) is laid on the photovoltaic backsheet, followed by a patterned insulating layer (IEC). Then, a robotic arm is used to pick up the solar cells printed with conductive adhesive and place them on the IEC layer.

[0004] 2. Laying the pre-sealing film, transparent front panel, and carrier glass. 3. Preheating: Use a halogen lamp to heat the battery cells, causing them to adhere to the pre-coating film. 4. After flipping, the components are laminated to obtain the final product.

[0005] In this process, step 3, the preheating step, is to bond the solar cells to the pre-coating film, preventing displacement of the module during the flipping and lamination vacuuming processes. However, the preheating process often introduces other adverse effects. Specifically, in the preheating process, halogen lamps heat both the solar cells and the pre-coating film, with the pre-coating film temperature exceeding 150°C. At this temperature, the pre-coating film undergoes a cross-linking reaction, leading to reduced film fluidity. During this process, if air bubbles exist between the film and the cell in the area irradiated by the halogen lamp, these bubbles cannot escape, resulting in residual bubbles and poor module appearance. If the heating time of the halogen lamp is reduced, the adhesion strength between the solar cells and the pre-coating film is insufficient, causing the solar cells to shift in subsequent processes. This contradiction results in a low process window and low yield for the preheating process. Summary of the Invention

[0006] To address the shortcomings of the existing technology, the present invention aims to provide a method for manufacturing a back-contact photovoltaic module. This method involves curing the conductive adhesive of the battery cells by energizing the positive and negative electrodes of the semi-finished module, thereby fixing the position of the battery cells. This replaces the original halogen lamp heating process, reducing energy consumption, shortening cycle time, improving production yield, and achieving cost reduction and efficiency improvement.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention discloses a method for manufacturing a back-contact photovoltaic module. In the process of manufacturing a conductive backsheet for a photovoltaic cell, a probe is loaded onto the positive and negative electrodes of a metal conductive layer and energized to form a path from the positive electrode of the metal conductive layer to the conductive adhesive, the positive electrode of the solar cell, the negative electrode of the solar cell, the conductive adhesive, and the negative electrode of the metal conductive foil. In the aforementioned pathway, the conductive adhesive generates the most heat among the several layers of material. During the heating process, the conductive adhesive cures, adhering the battery cell to the metal conductive foil and thus fixing the position of the battery cell.

[0008] Furthermore, the method confirms the connection between the conductive adhesive and the battery cell and the metal conductive foil based on the probe current.

[0009] Furthermore, the method includes the following steps: S1 is used to fabricate conductive metal foil. S2 uses PET or PC as the insulating layer substrate, and punches holes in the substrate to obtain the insulating layer IEC; S3 lays conductive metal foil and insulating layer sequentially on the backsheet of photovoltaic cell, and fixes the backsheet, PET material and insulating layer IEC to obtain a natural integrated backsheet; S4 battery cell printing and layout; S5 performs electrical welding, causing the two probe electrodes to automatically press down and form contact with the positive and negative electrodes of the conductive metal foil, so that the conductive adhesive adheres to the battery cell and the metal conductive foil; the probe current is adjusted to confirm the connection between the conductive adhesive and the battery cell and the metal conductive foil. S6 front adhesive film and front panel laying, laying the front adhesive film and front panel; S7 lamination yields laminated components; S8 installation of junction boxes, sorting, testing, and warehousing.

[0010] Furthermore, the probe is gold-plated; the current is a constant current source, the current is 5-25A, and the energizing time is 5-15 seconds.

[0011] Furthermore, in step S3, an infrared camera is also provided to monitor the heated conductive adhesive dots. If a short circuit is detected in a local area, the system will issue an alarm and prompt employees to carry out rework.

[0012] Furthermore, the conductive metal foil is copper foil or copper-aluminum foil. First, the metal foil is laminated with the conductive backing film through a lamination process at a lamination temperature of 80-150℃. The lamination film is made of low-basis-weight EVA with a basis weight of 200-300. After lamination, the metal foil is patterned by engraving or laser processing.

[0013] Furthermore, the conductive metal foil is a copper foil with a thickness of 15-50 μm, or a copper-aluminum foil with a thickness of 35-75 μm.

[0014] Furthermore, in step S3, the back panel, PET material, and insulating layer IEC are fixed by hot stamping to obtain an integrated back panel. Then, the integrated back panel is transferred to a carrier plate to reach the next work station.

[0015] Furthermore, in step S7, the lamination process is either two-cavity lamination or three-cavity lamination; for two-cavity lamination, the lamination temperature of the first cavity is 115-140℃, the lamination time is 5-20 minutes, and the lamination pressure is -60~-80kPa; the lamination temperature of the second cavity is 130-160℃, the lamination time is 5-20 minutes, and the lamination pressure is -70~-90kPa. For three-cavity lamination, a cooling process is added to the two-cavity lamination. The three-cavity lamination temperature is 25℃, the lamination time is 5-10 minutes, and the lamination pressure is -60~-80kPa.

[0016] This application also provides a back-contact photovoltaic module, which is manufactured using the above-described manufacturing method.

[0017] This invention improves the process method. Compared with existing processing methods, it fixes the position of the battery cells by curing the conductive adhesive of the battery through energizing the positive and negative electrodes of the semi-finished component. This replaces the original halogen lamp heating process, reducing energy consumption, shortening cycle time, improving production yield, and achieving cost reduction and efficiency improvement.

[0018] The present invention has the following advantages: 1. High yield rate, which can completely avoid the problem of preheating bubbles.

[0019] 2. High production efficiency: The processing cycle of this process is faster than that of the preheating process. The preheating process takes about 20 seconds to produce a component, while the power-on process only takes 5-10 seconds.

[0020] 3. This process also has the function of electrode detection, so that processing and detection can be carried out simultaneously.

[0021] 4. Reduce costs: The preheating process has high energy consumption (5KW power, 17KWh per day), while the PEC power-on process has low energy consumption (approximately 100W power, 0.17kWh per day, only one percent of the original process). Attached Figure Description

[0022] Figure 1 This is a flowchart of a method for manufacturing a back-contact photovoltaic module according to an embodiment of the present invention; Figure 2 This is a flowchart of the manufacturing method of the back-contact photovoltaic module in the comparative example of the present invention; Figure 3 The graphs show the relationship between energizing time and electrode temperature under different currents in Examples 1 to 4. Figure 4 Comparison chart of 2-hour yield data and statistical distribution of products made using the schemes provided in Example 1 and Comparative Example 1; Figure 5 This is a schematic diagram of the structure of the back-contact photovoltaic module provided in this application; In the figure, 1-front panel material layer, 2-first encapsulation material, 3-BC battery, 4-insulating material, 5-conductive metal foil and conductive adhesive, 6-second encapsulation material, 7-back panel material layer. Detailed Implementation

[0023] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0024] Example 1:

[0025] This embodiment is a method for manufacturing a back-contact photovoltaic module. In the process of manufacturing a conductive backsheet for a photovoltaic cell, a probe is loaded onto the positive and negative electrodes of a metal conductive layer and energized to form a path from the positive electrode of the metal conductive layer to the conductive adhesive, the positive electrode of the solar cell, the negative electrode of the solar cell, the conductive adhesive, and the negative electrode of the metal conductive foil. In the aforementioned pathway, the conductive adhesive generates the most heat among the several layers of material. During the heating process, the conductive adhesive cures, adhering the battery cell to the metal conductive foil and thus fixing the position of the battery cell.

[0026] This invention improves the process by curing the conductive adhesive of the battery cells by energizing the positive and negative electrodes of the semi-finished module, thereby fixing the position of the battery cells. This replaces the original halogen lamp heating process, reducing energy consumption, shortening cycle time, improving production yield, and achieving cost reduction and efficiency improvement.

[0027] Furthermore, based on the current, the connection between the conductive adhesive and the battery cell and conductive metal layer can also be determined. Therefore, this process not only fixes the battery cell but also performs a detection function, achieving simultaneous processing and detection and improving production efficiency.

[0028] Furthermore, the method includes the following steps: S1 is used to fabricate conductive metal foil. S2 uses PET or PC as the insulating layer substrate, and punches holes in the substrate to obtain the insulating layer IEC; S3 lays conductive metal foil and insulating layer sequentially on the backsheet of photovoltaic cell, and fixes the backsheet, PET material and insulating layer IEC to obtain a natural integrated backsheet; S4 battery cell printing and layout; S5 performs electrical welding, causing the two probe electrodes to automatically press down and form contact with the positive and negative electrodes of the conductive metal foil, so that the conductive adhesive adheres to the battery cell and the metal conductive foil; the probe current is adjusted to confirm the connection between the conductive adhesive and the battery cell and the metal conductive foil. S6 front adhesive film and front panel laying, laying the front adhesive film and front panel; S7 lamination yields laminated components; S8 installation of junction boxes, sorting, testing, and warehousing.

[0029] Furthermore, the probe is gold-plated; the current is a constant current source, the current is 5-25A, and the energizing time is 5-15 seconds.

[0030] Furthermore, in step S3, an infrared camera is also provided to monitor the heated conductive adhesive dots. If a short circuit is detected in a local area, the system will issue an alarm and prompt employees to carry out rework.

[0031] Furthermore, the conductive metal foil is copper foil or copper-aluminum foil. First, the metal foil is laminated with the conductive backing film through a lamination process at a lamination temperature of 80-150℃. The lamination film is made of low-basis-weight EVA with a basis weight of 200-300. After lamination, the metal foil is patterned by engraving or laser processing.

[0032] Furthermore, the conductive metal foil is a copper foil with a thickness of 15-50 μm, or a copper-aluminum foil with a thickness of 35-75 μm.

[0033] Furthermore, in step S3, the back panel, PET material, and insulating layer IEC are fixed by hot stamping to obtain an integrated back panel. Then, the integrated back panel is transferred to a carrier plate to reach the next work station.

[0034] Furthermore, in step S7, the lamination process is either two-cavity lamination or three-cavity lamination; for two-cavity lamination, the lamination temperature of the first cavity is 115-140℃, the lamination time is 5-20 minutes, and the lamination pressure is -60~-80kPa; the lamination temperature of the second cavity is 130-160℃, the lamination time is 5-20 minutes, and the lamination pressure is -70~-90kPa. For three-cavity lamination, a cooling process is added to the two-cavity lamination. The three-cavity lamination temperature is 25℃, the lamination time is 5-10 minutes, and the lamination pressure is -60~-80kPa.

[0035] This invention provides a manufacturing process for photovoltaic solar cells and modules. By energizing the positive and negative electrodes of the semi-finished module, the conductive adhesive of the cells is cured, fixing the position of the cells and preventing displacement and defects in subsequent processes. This invention overcomes the shortcomings of existing manufacturing processes (halogen lamp heating of the cells to adhere them to the pre-coating film), such as narrow process window, low yield, susceptibility to air bubbles, high energy consumption, and slow production cycle. It provides an integrated processing and inspection solution with high yield, low cost, and high efficiency.

[0036] Regarding the process steps, the existing process steps for conductive backsheet type back contact photovoltaic modules are as follows: 1. Fabrication of Conductive Metal Foil (PEC): Conductive metal foil is typically made of copper or copper-aluminum foil. First, the metal foil is laminated with a backing adhesive film using a lamination process at a temperature of 80-150℃. The copper foil thickness is 15-50µm, and the copper-aluminum foil thickness is 35-75µm. The laminating film is generally made of low-basis-weight EVA, with a basis weight between 200-300. After lamination, the metal foil is patterned using a scriber or laser processing. Tungsten carbide blades are typically used for scribes, with a scribe speed of 150-300mm / s.

[0037] 2. Insulation layer (IEC) processing: The substrate of the insulation layer can be PET or PC. Taking PET as an example, the processing method can be mechanical punching or laser drilling.

[0038] 3. Integrated backsheet stacking and loading: Conductive metal foil and insulating layer are laid on the photovoltaic backsheet in one go. The backsheet, PEC, and IEC are fixed by hot stamping. Then, the integrated backsheet is transferred to a carrier plate, which carries the integrated backsheet to the next station on the production line. 4. Cell printing and layout: At this station, the cells undergo conductive adhesive printing and laser scribing. Then, the robotic arm places the processed cells onto the IEC according to the predetermined position, and the carrier board flows to the next station.

[0039] 5. Front film and front panel installation: The film-laying machine cuts the roll of film into sheets, then uses suction cups to pick them up and place them onto the solar cells. Subsequently, the suction cups pick up the front panel and glass, and sequentially lay them onto the front film. The front film can be EVA, POE, or EPE, and the front panel can be a photovoltaic transparent front panel or photovoltaic glass. 6. Halogen lamp preheating process: At this station, each solar cell is placed above a halogen lamp, with the lamp positioned 25-50mm above the cell. The halogen lamp heats each cell 2-5 times, with each heating cycle lasting 5-10 seconds. After each heating cycle, the carrier plate moves forward 10-30mm before proceeding to the next heating point. After the last heating point is completed, the carrier plate flows to the next station. 7. Lamination: After the semi-finished product with the front panel and front adhesive film laid, lamination is performed to obtain the laminated part. The lamination process is generally two-cavity lamination or three-cavity lamination. For two-cavity lamination, the lamination temperature of the first cavity is 115-140℃, the lamination time is 5-20 minutes, and the lamination pressure is -60~-80kPa; the lamination temperature of the second cavity is 130-160℃, the lamination time is 5-20 minutes, and the lamination pressure is -70~-90kPa. For three-cavity lamination, a cooling process is added to the two-cavity lamination process; the temperature of the third cavity is 25℃, the lamination time is 5-10 minutes, and the lamination pressure is -60~-80kPa. 8. Install junction boxes and sort, test, and store the products. This step yields the final product.

[0040] Compared with existing processing technologies, this invention has the following advantages: high yield, completely avoiding preheating bubble problems; high production efficiency, with a faster processing cycle than the preheating process, which requires about 20 seconds to produce one component, while the energized process only requires 5-10 seconds; the process also has electrode detection capabilities, enabling processing and detection to be performed simultaneously; and reduced costs, as the preheating process has high energy consumption (5KW power, 17KWh per day), while the PEC energized process has low energy consumption (approximately 100W power, 0.17kWh per day, only one percent of the energy consumption of the original process).

[0041] The technical effects of the present application's technical solution are illustrated below with reference to one comparative example and four embodiments: Comparative Example 1: like Figure 2 As shown in the comparison, the photovoltaic module manufacturing process is as follows: 1. Lay the prefabricated integrated conductive backsheet (the integrated conductive backsheet includes a photovoltaic backsheet, conductive metal foil, and insulating material) on the carrier.

[0042] 2. The carrier is transferred to the next station, where the robotic arm picks up the battery cells and places them face down on the integrated conductive backplate according to the preset layout.

[0043] 3. The carrier is transferred to the next station, where the film-laying machine lays the POE onto the battery cells. Then, the robotic arm controls the suction cup to grab the front panel and glass and place them onto the film.

[0044] 4. The carrier transfers the battery to the halogen lamp preheating station. The halogen lamp is 35mm above the battery cell. There is one halogen lamp above each battery cell. Each heating time of the lamp is 8 seconds. Each battery cell is heated a total of 3 times.

[0045] 5. The preheated components enter the laminator, where they are laminated, fitted with junction boxes, cured, inspected, and then stored.

[0046] like Figure 1 The diagram shows a flowchart of the manufacturing method of the back-contact photovoltaic module of this application. The specific implementation process is listed in the following embodiments: Example

[0047] 1. Lay the prefabricated integrated conductive backsheet (the integrated conductive backsheet includes a photovoltaic backsheet, conductive metal foil, and insulating material) on the carrier.

[0048] 2. The carrier is transferred to the next station, where the robotic arm picks up the battery cells and arranges them according to a preset layout. The battery cells are then placed face down on the integrated conductive backplate to form an assembly.

[0049] 3. The carrier is transferred to the next station, where the gold-plated electrode probes are pressed onto the positive and negative terminals of the conductive metal backplate. A constant current source powers the positive and negative terminals of the assembly with a current of 6 amps for 18 seconds, completing the connection between the battery cell and the conductive metal backplate.

[0050] 4. The carrier is transferred to the next station, where the film-laying machine lays the POE onto the battery cells. Then, the robotic arm controls the suction cup to grab the front panel and glass and place them onto the film.

[0051] 5. The preheated components enter the laminator, where they are laminated, fitted with junction boxes, cured, inspected, and then stored.

[0052] Example 2:

[0053] 1. Lay the prefabricated integrated conductive backsheet (the integrated conductive backsheet includes a photovoltaic backsheet, conductive metal foil, and insulating material) on the carrier.

[0054] 2. The carrier is transferred to the next workstation, where the robotic arm picks up the battery cells and arranges them according to a preset layout. The battery cells are then placed face down on the integrated conductive backplate to form an assembly. 3. The carrier is transferred to the next station, where the gold-plated electrode probes are pressed onto the positive and negative terminals of the conductive metal backplate. A constant current source powers the positive and negative terminals of the assembly with a current of 8 amps for 14 seconds, completing the connection between the battery cell and the conductive metal backplate.

[0055] 4. The carrier is transferred to the next station, where the film-laying machine lays the POE onto the battery cells. Then, the robotic arm controls the suction cup to grab the front panel and glass and place them onto the film.

[0056] 5. The preheated components enter the laminator, where they are laminated, fitted with junction boxes, cured, inspected, and then stored.

[0057] Example 3:

[0058] 1. Lay the prefabricated integrated conductive backsheet (the integrated conductive backsheet includes a photovoltaic backsheet, conductive metal foil, and insulating material) on the carrier.

[0059] 2. The carrier is transferred to the next workstation, where the robotic arm picks up the battery cells and arranges them according to a preset layout. The battery cells are then placed face down on the integrated conductive backplate to form an assembly. 3. The carrier is transferred to the next station, where the gold-plated electrode probes are pressed onto the positive and negative terminals of the conductive metal backplate. A constant current source powers the positive and negative terminals of the assembly with a current of 10 amps for 12 seconds, completing the connection between the battery cell and the conductive metal backplate.

[0060] 4. The carrier is transferred to the next station, where the film-laying machine lays the POE onto the battery cells. Then, the robotic arm controls the suction cup to grab the front panel and glass and place them onto the film.

[0061] 5. The preheated components enter the laminator, where they are laminated, fitted with junction boxes, cured, inspected, and then stored.

[0062] Example 4:

[0063] 1. Lay the prefabricated integrated conductive backsheet (the integrated conductive backsheet includes a photovoltaic backsheet, conductive metal foil, and insulating material) on the carrier.

[0064] 2. The carrier is transferred to the next workstation, where the robotic arm picks up the battery cells and arranges them according to a preset layout. The battery cells are then placed face down on the integrated conductive backplate to form an assembly. 3. The carrier is transferred to the next station, where the gold-plated electrode probes are pressed onto the positive and negative terminals of the conductive metal backplate. A constant current source powers the positive and negative terminals of the assembly with a current of 12 amps for 12 seconds, completing the connection between the battery cell and the conductive metal backplate.

[0065] 4. The carrier is transferred to the next station, where the film-laying machine lays the POE onto the battery cells. Then, the robotic arm controls the suction cup to grab the front panel and glass and place them onto the film.

[0066] 5. The preheated components enter the laminator, where they are laminated, fitted with junction boxes, cured, inspected, and then stored.

[0067] Based on the fabrication method described in the embodiments of this application, the relationship between the energizing time and the temperature of the electrode point under different currents is as follows: Figure 3 As shown, from 6A to 12A, the highest electrode temperature remained between 155-160℃, indicating that the conductive adhesive cured at this temperature, resulting in lower resistance and thus lower heat generation. At 6A, it took more than 10 seconds for the electrode to begin curing. As the current increased, the curing time decreased, reaching 6 seconds at 12A. Further increasing the current did not significantly reduce the curing start time and posed a risk of damage to the photovoltaic modules; therefore, the current should not exceed 12A.

[0068] The 2-hour yield data and statistical distribution of Example 1 and Comparative Example 1 are as follows: Figure 4 As shown, the yield trends of the two processes were statistically analyzed for the same materials and within the same time period. The yield of the traditional process (i.e., the comparative example) in Comparative Example 1 fluctuated between 85% and 92%, with an average of less than 89%. In Example 1 of the process of this invention, the yield varied between 89% and 96% within the same time period, with an average of 92.8%, which is a significant improvement compared to the traditional process.

[0069] Example 5:

[0070] like Figure 5 As shown, this application also provides a back-contact photovoltaic module, which is manufactured using the above-described method. The module structure includes a front panel material layer 1, a first encapsulation material 2, a BC cell 3, an insulating material 4, a conductive metal foil and conductive adhesive 5, a second encapsulation material 6, and a back panel material layer 7.

[0071] The material composition of the front panel material layer 1 includes any one or a combination of the following: tempered glass, PC board, PET board, ETFE board, FEP board, PMMA board.

[0072] The encapsulation materials are EVA, POE, PVB, adhesives, silicone materials, or adhesive films or adhesive materials containing colored particles.

[0073] The BC battery 3 can be a P-type BC battery, an N-type BC battery, a TOPCon-type BC battery (TBC), an HJT-type BC battery (HBC), etc.

[0074] The insulating material 4 can be PET, PC, silicone, or a combination thereof. In the conductive metal foil and conductive adhesive 5, the conductive metal foil can be copper foil, aluminum foil, tin foil, or their alloy metal foil, and the conductive adhesive can be silver paste, aluminum paste, tin paste, or their alloy paste. The material composition of the back panel material layer 7 includes any one or a combination of the following: tempered glass, PC board, PET board, ETFE board, FEP board, PMMA board, carbon fiber board, and aluminum alloy board.

[0075] This invention has many specific applications. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A method of fabricating a back contact photovoltaic module, comprising: The method is used for making the conductive backboard of the photovoltaic cell, and the probes are loaded on the positive and negative electrodes of the metal conductive layer to form a path of the positive electrode of the metal conductive layer-conductive adhesive-positive electrode of the cell-negative electrode of the cell-conductive adhesive-negative electrode of the metal conductive foil. In the path, the conductive adhesive generates the maximum heat in the several layers of materials, the conductive adhesive is solidified in the process of heat generation, the cell is adhered to the metal conductive foil, and the fixing of the position of the cell is completed.

2. The method of making a back contact photovoltaic assembly of claim 1, wherein, The method confirms the connection between the conductive adhesive and the cell and the metal conductive foil according to the probe current.

3. The method of making a back contact photovoltaic assembly of claim 1, wherein, The method comprises the following steps: S1, making the conductive metal foil; S2, using PET or PC as the base material of the insulating layer, punching the base material to obtain the insulating layer IEC; S3, sequentially laying the conductive metal foil and the insulating layer on the backboard of the photovoltaic cell, fixing the backboard, the PET material and the insulating layer IEC to obtain the integrated backboard; S4, printing and layout of the cell; S5, welding by electrifying, automatically pressing the two probe electrodes to form the contact with the positive and negative electrodes of the conductive metal foil, adhering the conductive adhesive to the cell and the metal conductive foil, adjusting the probe current to confirm the connection between the conductive adhesive and the cell and the metal conductive foil; S6, laying the front adhesive film and the front plate; S7, obtaining the laminated part after lamination; S8, installing the junction box and sorting and testing to store.

4. The method of making a back contact photovoltaic assembly of claim 3, wherein, The probe is gold-plated; the current is a constant current source, the current is 5-25 A, and the electrifying time is 5-15 seconds.

5. The method of making a back contact photovoltaic assembly of claim 4, wherein, In the step S3, an infrared camera is further arranged to monitor the conductive adhesive points generating heat, and if the local area short circuit is found, the system will issue an alarm and prompt the staff to repair.

6. The method of making a back contact photovoltaic assembly of claim 3, wherein, The conductive metal foil is a copper foil or a copper-aluminum foil, the metal foil is first compounded with the conductive backboard adhesive film through a film coating process, the compounding temperature is 80-150 DEG C, the film coating adhesive film selects low gram weight EVA, the gram weight is 200-300; after the compounding of the metal foil, the patterning is realized through the way of a graver or laser processing.

7. The method of making a back contact photovoltaic assembly of claim 6, wherein, The conductive metal foil is a copper foil, the thickness is 15-50 um, the conductive metal foil is a copper-aluminum foil, the thickness is 35-75 um.

8. The method of making a back contact photovoltaic assembly of claim 3, wherein, In the step S3, the backboard, the PET material and the insulating layer IEC are fixed by the way of spot pressing to obtain the integrated backboard, and then the integrated backboard is transferred to the carrier plate to reach the next station.

9. The method of making a back contact photovoltaic assembly of claim 3, wherein, In the step S7, the lamination process is double-cavity lamination or three-cavity lamination; for the double-cavity lamination, the one-cavity lamination temperature is 115-140 DEG C, the lamination time is 5-20 minutes, the lamination pressure is -60~-80 kPa, the two-cavity lamination temperature is 130-160 DEG C, the lamination time is 5-20 minutes, and the lamination pressure is -70~-90 kPa; For the three-cavity lamination, the cooling process is added on the basis of the double-cavity lamination, the three-cavity lamination temperature is 25 DEG C, the lamination time is 5-10 minutes, and the lamination pressure is -60~-80 kPa.

10. Back contact photovoltaic module, characterized in that The photovoltaic module is made by the manufacturing method in any one of claims 1 to 9.

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