Integrated packaging manufacturing method for photovoltaic module

Abstract

The invention discloses an integrated packaging and manufacturing method for a photovoltaic module, and the method comprises the following steps: 1, laying a transparent front plate; step 2, flatly laying a first laminated layer; 3, placing a plurality of battery strings which are connected in series, and carrying out series welding or parallel welding; 4, leading out the positive / negative electrodes of all or part of the battery pieces by using a plurality of conductive adhesive tapes according to the set layout; 5, placing a plurality of diode strings, enabling the conductive layers at the plurality of windows on the substrate layers of the diode strings to be in one-to-one correspondence overlapping contact electric connection with the plurality of conductive adhesive tapes, and keeping the diode strings and the battery strings at parallel intervals or overlapping; 6, laying a second laminated layer and a back plate; 7, laminating is conducted, and a laminated piece is obtained; and 8, trimming the laminated piece, and installing a junction box to obtain the finished photovoltaic module. The diode string and the battery string are integrally and synchronously packaged in the laminated layer, so that the reliability of the whole photovoltaic module is improved, and the photovoltaic module is convenient to produce and manufacture.

Description

[0001] This application is a divisional application of the invention patent application filed on August 26, 2024, with application number 202411174155.7 and entitled "A method for manufacturing a photovoltaic module with multiple bypass diodes". Technical Field

[0002] This invention specifically relates to a method for manufacturing a photovoltaic module with multiple bypass diodes, belonging to the field of solar photovoltaic module manufacturing technology. Background Technology

[0003] A photovoltaic (PV) module is a solar panel formed by connecting a certain number of PV cells in series and parallel according to a predetermined sequence, creating a PV power generation panel with a specific voltage and current. Traditional PV modules, such as the 60-cell and 72-cell models, divide 60 and 72 cells respectively into six strings of 10 and 12 cells each. These six strings are connected in series. Furthermore, a diode is connected in reverse parallel to each pair of adjacent strings near the lead wires, for a total of three diodes. These three diodes, along with the two lead wires, are integrated into the junction box of the PV module. These diodes are referred to in the industry as bypass diodes because when any one or more cells in the corresponding two strings are damaged, shaded, or experience a significant reduction in current, this diode conducts. The current generated by the other normally generating strings will partially or completely pass through this diode, acting as a bypass to prevent damaged or shaded cells from becoming a load and overheating, thus reducing the loss of power generation from the PV module. This conventional photovoltaic module with three bypass diodes is suitable for large-scale photovoltaic power plants because the failure of one or more strings of cells in a photovoltaic module to generate electricity has a very small impact on the entire photovoltaic power plant, which can be described as negligible. However, for portable mobile photovoltaic modules used outdoors alone or with a small number of modules connected in series and parallel, even the damage to one cell will affect the power output of the entire system. Therefore, it is necessary to connect bypass diodes in parallel to all cells or a specified portion of cells in the photovoltaic module to improve its reliability. However, the existing photovoltaic module design cannot meet this requirement, and there is no mature method to integrate all bypass diodes into the photovoltaic module. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides a method for manufacturing a photovoltaic module with multiple bypass diodes.

[0005] The technical solution adopted in this invention is: A method for manufacturing a photovoltaic module with multiple bypass diodes includes the following steps: Step 1: Lay the transparent front panel horizontally on a flat surface; Step 2: Lay the first laminated layer flat on the front panel; Step 3: Place multiple battery strings that have been connected in series on the first interlayer, with the light-receiving surface of the battery cells in the battery strings facing down, and weld the battery strings in series or in parallel using busbars according to the set layout. Step 4: According to the set layout, use multiple conductive tapes to lead out all or part of the positive / negative electrodes of the battery cells, and bond the conductive tapes to the first interlayer. Step 5 includes the following sub-steps: 5.1 Lay a backing plate on a flat surface, stack a second adhesive layer on the backing plate, place multiple diode strings at specific positions on the second adhesive layer, and fix the diode strings with positioning tape. 5.2 Cover the diode string with a release film, and then transfer the entire backplate and its carrier to a laminator for vacuum high-temperature lamination pre-pressing. After the pre-pressing is completed, remove the release film to obtain the backplate pre-pressed part. 5.3. The aforementioned backplate pre-pressed component is inverted onto the battery cell with conductive tape pasted in step 4 above, so that the diode string and multiple conductive tapes are perpendicularly overlapped and electrically connected, and the diode string and battery string are kept parallel and spaced apart or overlapped; then the laminated component is transferred to a laminator for final lamination to obtain the laminated component; Finally, after trimming the laminate, the junction box is installed to obtain the finished photovoltaic module with multiple bypass diodes.

[0006] Furthermore, the finished photovoltaic module contains m cell strings and p diode strings. Each cell string includes n series-connected cells, and each diode string includes q series-connected diodes. The n cells are aligned in the same direction and arranged in a straight line, and the q diodes are aligned in the same direction and arranged in a straight line. The diode strings are connected in antiparallel to one or more corresponding cell strings, and the diodes are connected in antiparallel to one or more corresponding cells. Here, m, n, p, and q are all positive integers, m≥1, n≥2, p≤m, and q≤n.

[0007] Furthermore, the diode string includes a long strip-shaped substrate layer on which multiple diodes are disposed. The positive and negative terminals of adjacent diodes are electrically connected through a conductive layer. The positive and negative terminals of two diodes at both ends are also led out through the conductive layer. The conductive layer is centrally disposed on the substrate layer, and the width of the conductive layer is smaller than the width of the substrate layer.

[0008] Furthermore, in the finished photovoltaic module, the conductive tape leads out the positive or negative electrode of the corresponding cell and makes a conductive connection with the negative or positive electrode of the corresponding diode, respectively.

[0009] Furthermore, the substrate layer is an insulating substrate layer, and multiple windows are centrally spaced on the insulating substrate layer, which allow the conductive layer on the insulating substrate layer to conduct downwards.

[0010] Furthermore, in step 5.3, the substrate layer of the diode string is in perpendicular overlapping contact with the conductive tape, and multiple windows on the substrate layer of the diode string overlap with multiple conductive tapes in a one-to-one correspondence, with the conductive layer at the window electrically connected to the conductive tape.

[0011] Furthermore, the window is rectangular or square, with the long side of the rectangle perpendicular to the long side of the substrate layer. The length of the long side of the rectangle is greater than the width of the conductive layer, or the side length of the square is greater than the width of the conductive layer. The substrate material at the window is not completely removed, but is cut along the two long sides of the rectangle, leaving the two short sides connected to the substrate body. It is then cut along the centerline parallel to the short sides, forming two substrate blades similar to two double doors. After the two substrate blades are folded over, they simultaneously press the conductive layer underneath.

[0012] Furthermore, the battery cell is a conventional battery cell with the positive and negative electrodes located on both sides of the battery cell, and conductive tape is pasted on the middle of the back of all or part of the battery cell, and the conductive tape is bonded to the first interlayer.

[0013] Furthermore, the battery cell can also be a back contact cell with both positive and negative electrodes located on the back side of the battery cell. Conductive tape is pasted on the interconnecting strips at both ends of all or part of the battery cells and on the interconnecting strips between the battery cells, and the conductive tape is bonded to the first interlayer.

[0014] Beneficial Effects: This invention provides a photovoltaic module with multiple bypass diodes and its manufacturing method. m cell strings and p diode strings are encapsulated in an adhesive layer between the front and back panels of the photovoltaic module. The diode strings are parallel or overlapping with the cell strings, and are connected in reverse parallel with one or more corresponding cell strings. The diodes are also connected in reverse parallel with one or more corresponding solar cells. The diode strings and cell strings are synchronously or sequentially encapsulated within the adhesive layer of the photovoltaic module, perfectly integrated, thereby improving the overall reliability of the photovoltaic module and facilitating manufacturing. When any one or more solar cells in the photovoltaic module are shaded or damaged, corresponding bypass diodes provide bypass protection, minimizing the impact on the photovoltaic module's power output. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the photovoltaic module layout in Example 1.

[0016] Figure 2 yes Figure 1 The circuit diagram.

[0017] Figure 3 This is a schematic diagram of the photovoltaic module layout in Example 2.

[0018] Figure 4 yes Figure 3 The circuit diagram.

[0019] Figure 5 This is a schematic diagram of the photovoltaic module layout in Example 3.

[0020] Figure 6 yes Figure 5 The circuit diagram.

[0021] Figure 7 This is a schematic diagram of the photovoltaic module layout in Example 4.

[0022] Figure 8 yes Figure 7 The circuit diagram.

[0023] Figure 9 This is a schematic diagram of a diode string structure.

[0024] Figure 10 This is a schematic diagram of a conventional solar cell structure.

[0025] Figure 11 This is a schematic diagram of the photovoltaic module layout in Example 5.

[0026] Figure 12 This is a schematic diagram of the front plate pre-compression component in Example 5.

[0027] Figure 13 This is a schematic diagram of the backplate pre-compression component in Example 5.

[0028] Figure 14 This is a schematic diagram of the photovoltaic module layout in Example 6.

[0029] Figure 15 This is a schematic diagram of the grid lines on the back of the back-contact solar cell.

[0030] Figure 16 This is a schematic diagram of the intermediate circuit layer structure in Example 7.

[0031] Figure 17 This is a schematic diagram of the battery cells and diodes connected on the intermediate circuit layer of Example 7.

[0032] The markings in the diagram are: 1. Battery string, 2. Diode string, 3. Conductive tape, 4. Busbar, 5. Front panel, 6. Back panel, 7. Second adhesive film, 8. Positioning tape, 9. First adhesive film, 10. Interconnect strip, 11. Battery cell, 12. Positive lead strip, 13. Negative lead strip, 21. Substrate layer, 22. Diode, 23. Conductive layer, 211. Substrate blade, 212. Window, 213. Lead group, 2131. Positive lead, 2132. Negative lead, 214. Interconnect line, 215. Busbar, 216. Lead line, 217. Diode connection terminal, 218. Positioning mark, 219. Component positive and negative connection terminal, 111. Positive grid line, 112. Negative grid line. Detailed Implementation

[0033] To better understand the technical solutions of this application, a clear and complete detailed description of this application is provided below with reference to the accompanying drawings. It should be understood that the described embodiments are merely some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort, as well as new embodiments obtained by recombination of features between different embodiments without conflict, are within the scope of protection of this application.

[0034] A typical crystalline silicon solar photovoltaic module usually consists of a front panel and a back panel, with crystalline silicon photovoltaic cells encapsulated between them via an adhesive layer. The front panel, requiring light transmission, is typically made of transparent materials such as glass or other inorganic or organic transparent materials like ETFE. The back panel is usually made of organic polymer materials such as TPT, with an air surface and an adhesive surface on its two sides. The adhesive layer usually consists of two layers of EVA material fused together, with adjustable thicknesses, for example, both 0.5mm. Multiple cells are interconnected and positioned between the two EVA layers, temporarily secured with positioning tape to prevent cell displacement. Because the distance between cells and between cell strings is very narrow, typically only 2-3mm, temporary fixation with positioning tape is necessary before lamination. After high-temperature vacuum lamination, the EVA material undergoes a cross-linking reaction, fusing together to encapsulate and fix the cells, bonding the front and back panels into a single unit. Finally, the junction box and frame are installed to obtain the finished photovoltaic module.

[0035] This patent improves upon existing photovoltaic modules by providing a photovoltaic module with multiple bypass diodes. It encapsulates m cell strings and p diode strings between the front and back panels via an adhesive layer. Each cell string includes n cells connected in series, and each diode string includes q bypass diodes connected in series. The cells are conventional crystalline silicon cells, and their structure is as follows: Figure 10As shown, a conventional battery cell 11 includes two sides, corresponding to the positive / negative electrode (or negative / positive electrode) of the battery. Both sides are screen-printed with silver grid lines for collecting current, and multiple positive and negative electrode lead interconnection strips are soldered out from the main grid lines. The battery cell shown in the figure is placed with the back side (reverse side) facing up and has a positive electrode lead interconnection strip 12, and the battery cell is placed with the front side (light-receiving side) facing down and has a negative electrode lead interconnection strip 13. The distinction between the positive and negative polarities of the two sides of the battery is related to the battery manufacturing process. The size of the solar cells can be a standard full square (or a square with chamfered corners), such as 125*125mm, 156*156mm, 182*182mm, 210*210mm, etc., or a 1 / 2, 1 / 3, or 1 / 4 slice of a square. n solar cells are aligned in a straight line, with the positive and negative terminals of adjacent cells connected. q bypass diodes are aligned in a straight line, with the positive and negative terminals of adjacent diodes connected. The diode string is parallel or overlaps with the battery string. The diode string is connected in anti-parallel to one or more corresponding battery strings, and the diode is connected in anti-parallel to one or more corresponding solar cells. Where m, n, p, and q are all positive integers, m≥1, n≥2, p≤m, q≤n. For example, m or p can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc., and n or q can be 2, 4, 6, 8, 9, 10, 12, 18, 24, 36, 48, 60, 72, etc.

[0036] like Figure 9As shown, the diode string 2 includes a long strip-shaped substrate layer 21 on which multiple surface-mount diodes 22 are disposed. These diodes, such as thin-film Schottky diodes, have a thickness ranging from tens to hundreds of micrometers, for example, 200 micrometers. Their electrical performance is matched to that of the photovoltaic cell. They are attached to the substrate layer by adhesive. The positive and negative terminals of adjacent diodes 22 are electrically connected through a conductive layer 23, which is also attached to the substrate layer by adhesive. The positive and negative terminals of two diodes at opposite ends are also led out through the conductive layer. The conductive layer can be a metal foil, such as copper foil, and is centrally located on the substrate layer. The width of the conductive layer is smaller than the width of the substrate layer. Further, the substrate layer 21 is an insulating substrate layer, such as PET. Its width is determined according to actual needs, for example, 10 mm, and its thickness can range from tens to 100 micrometers or even hundreds of micrometers. Multiple windows 212 are centrally spaced on the insulating substrate layer. The window shape can be rectangular, square, or circular. These windows allow the conductive layer 23 on the insulating substrate layer to conduct downwards. The window shown in the figure is rectangular, and the substrate material at the window is not completely removed. Instead, it is cut along the two long sides of the rectangle, leaving the two short sides connected to the substrate body. It is then cut along the midline parallel to the short sides, forming two substrate blades 211 resembling two double doors. These two substrate blades are then folded over, simultaneously pressing the conductive layer underneath, allowing the conductive layer to conduct electricity downwards through the window. When pressure is applied to the two substrate blades at the window, the corresponding conductive layer bends at the window, making the conductive layer coplanar with the back of the substrate. The substrate layer serves as a support layer, facilitating the fabrication and overall movement of the diode string; it also provides insulation to avoid unnecessary electrical contact. The overall thickness of the diode string is less than 0.5mm. During module encapsulation, the cell string and diode string can be laminated between two layers of EVA and electrically connected using conductive adhesive tape. The EVA melts and cross-links, simultaneously encapsulating the cell and diode, perfectly integrating multiple diodes into a conventional photovoltaic module.

[0037] Example 1 like Figure 1As shown, in this example, m=2, n=4, p=2, q=4. The photovoltaic module in this example includes two cell strings 1 and two diode strings 2, shown in the dashed boxes. Each cell string includes four interconnected solar cells 11, and the two cell strings 1 are also interconnected via busbars 4. Each diode string includes four interconnected diodes, located outside the cell strings, parallel but not overlapping. The photovoltaic module also includes multiple regularly arranged long rectangular double-sided conductive tapes 3. Each cell has one conductive tape 3 attached to it. The conductive tape 3 is attached to the middle of the back of the cell and extends outward to bond with the EVA film under the cell. The conductive tape 3 leads out the positive and / or negative electrode of the corresponding cell. The conductive tape 3 at one end of the cell string is conductively connected to the bus bar 4. The diode string 2 is vertically stacked on the outer end of the conductive tape 3, and the window on the diode string corresponds one-to-one with the conductive tape below it. After subsequent lamination and pressure, the conductive layer 23 on the diode string can be conductively connected to the conductive tape 3 below it through the window 211, realizing the conductive connection between the conductive tape 3 and the negative and / or positive electrode of the corresponding diode. The conductive tape serves two purposes: it leads out the positive and negative terminals of the corresponding solar cells and makes them conductively connected to the negative and positive terminals of the corresponding diodes, respectively; it also serves to bond and position the solar cells (strings), preventing displacement of the cell strings during subsequent movement or lamination. It can partially or completely replace the use of positioning tape in the conventional paving process of photovoltaic module manufacturing. The circuit diagram of this photovoltaic module is shown below. Figure 2 As shown, in this example, eight solar cells are connected in series, and each solar cell is connected in reverse parallel with a diode, for a total of eight diodes. When any solar cell is blocked or damaged, the diode connected in reverse parallel with that solar cell can immediately bypass the circuit.

[0038] Example 2 like Figure 3 As shown, in this example, m=2, n=4, p=2, q=2. Similar to Example 1, this photovoltaic module also includes two cell strings and two diode strings. Each cell string includes four cells connected in series, and the two cell strings are also connected in series. The diode strings are located outside the cell strings, parallel but not overlapping. The photovoltaic module also includes multiple conductive tapes 3, which have the same function. The difference from Example 1 is that each diode string includes two diodes connected in series, and a conductive tape is placed every other cell. The circuit diagram of this photovoltaic module is shown below. Figure 4As shown, in this example, eight solar cells are connected in series, and a diode is connected in reverse parallel for every two series-connected solar cells, for a total of four diodes. This means one diode bypasses and protects two series-connected solar cells, thus reducing the number of diodes required. Of course, the diode configuration can be flexibly configured according to needs. For example, when the number of solar cells in each string is a multiple of three (e.g., nine cells), a diode connected in reverse parallel for every three series-connected solar cells can be used. An unevenly distributed configuration is also possible.

[0039] Example 3 like Figure 5 As shown, in this example, m=2, n=4, p=1, q=4. The photovoltaic module in this example also includes two battery strings, each containing four cells connected in series. The difference from Example 1 is that in this example, the two battery strings are connected in parallel, sharing one diode string. The diode string is parallel or overlaps with the battery strings; the diode string shown in the figure is located between the two battery strings, and all three are parallel but do not overlap. The photovoltaic module also includes multiple conductive tapes 3; in this example, there are five conductive tapes, whose function is the same as in Example 1, and corresponding cells in the two battery strings share one conductive tape. The circuit diagram of this photovoltaic module is shown below. Figure 6 As shown, a diode is connected in reverse parallel for every two parallel solar cells, for a total of four diodes. This means that one diode bypasses and protects two solar cells, which also reduces the number of diodes required.

[0040] Example 4 like Figure 7 As shown, in this example, m=2, n=4, p=2, q=4. The photovoltaic module in this example also includes two cell strings, each containing four cells connected in series. The two cell strings are connected in parallel, and the cell layout is the same as in Example 3. The difference from Example 3 is that this example includes two diode strings, with one cell string corresponding to one diode string, and the diode strings and cell strings are arranged overlapping. Conductive tape is applied to each cell before overlapping, serving both a conductive and positioning function. The circuit diagram of the photovoltaic module in this example is shown below. Figure 8 As shown.

[0041] Example 5 like Figure 11 As shown, in this example, m=2, n=4, p=2, q=4. The battery string and diode string in this example are the same as in Example 1, and their circuit diagram is shown below. Figure 2 The only difference from Example 1 is that the diode string and the battery string are arranged in an overlapping manner.

[0042] Example 6 like Figure 14As shown, in this example, m=2, n=4, p=2, q=4. The layout of the battery string and diode string in this example is the same as in Example 5, both using an overlapping arrangement. The difference between this example and Example 5 is that the conductive tape 3 is pasted onto the interconnecting strip 10 between the battery cells and at the intersection of the interconnecting strip 10 and the busbar 4 at both ends of the battery string. This method of pasting the conductive tape is applicable to applications such as... Figure 10 The image shows a conventional solar cell (with the positive and negative electrodes on both sides), and it is also compatible with... Figure 15 The back contact cell shown, Figure 15 The back-contact solar cell shown has no grid lines on its front side (light-receiving surface), so there is no light obstruction. Multiple positive grid lines 111 and multiple negative grid lines 112 are arranged in parallel and intersecting directions on its back side. That is, the positive and negative grid lines of the back-contact solar cell are simultaneously located on the back side of the cell. The positive and negative electrodes can be led out separately by welding interconnecting strips to the grid lines. Therefore, conductive tape cannot be directly pasted onto the back side of the solar cell, otherwise a short circuit will occur. The conductive tape can only be pasted onto the interconnecting strips between the solar cells. For photovoltaic modules using back-contact solar cells, the arrangement between the diode strings and the cell strings can also adopt a parallel but non-overlapping arrangement similar to that shown in Example 1.

[0043] The integrated packaging manufacturing method for photovoltaic modules with multiple bypass diodes described in Examples 1-6 above is as follows: Step 1: Lay the transparent front panel horizontally on a flat surface; Step 2: Lay the first laminated layer flat on the front panel; Step 3: Place multiple battery strings with multiple battery cells connected in series on the first interlayer, with the light-receiving surface of the battery cells facing down, and weld the battery strings in series or in parallel using busbars according to the set layout. Step 4: According to the set layout, use multiple conductive tapes to bring out all or part of the positive / negative electrodes of the battery cells; for example, for conventional battery cells, conductive tape can be pasted on the middle of the back of all or part of the battery cells and bonded to the first interlayer; for back contact battery cells, conductive tape can be pasted on both ends of the battery cells and on the interconnecting strips between the battery cells and bonded to the first interlayer. Step 5: Place multiple diode strings according to the set layout. The substrate layer of the diode string is perpendicularly overlapped with the conductive tape and made to make electrical contact. The conductive layer at multiple windows on the substrate layer of the diode string is overlapped with multiple conductive tapes and made to make electrical contact. The diode string and the battery string are kept parallel and spaced apart or overlapped. Step 6: Lay the second interlayer and the backplate in sequence. The adhesive side of the backplate is facing down and in contact with the second interlayer, and the air side of the backplate is facing up. If necessary, the positive and negative leads of the battery string can be led out from the backplate or the front plate to obtain the laminated part. Step 7: Transfer the above-mentioned laminated parts to a vacuum high-temperature laminator for lamination to obtain the laminated parts; Step 8: After trimming the laminate, install the frame and install the junction box at the positive and negative leads on the back or front panel to obtain the finished photovoltaic module with multiple bypass diodes. No diodes are required in the junction box.

[0044] When using the integrated packaging manufacturing method described above to produce the modules shown in Examples 1-6, the problem of needing to configure bypass diodes for multiple solar cells is solved. However, for Examples 1-3, since the diode strings and solar cell strings are parallel and spaced apart and do not overlap, the diode strings need to occupy a certain space area. Under the premise that the solar cell layout of the photovoltaic module remains unchanged, this will lead to an increase in the size of the photovoltaic module, a decrease in the efficiency of the module, and poor compatibility with conventional photovoltaic modules. Therefore, in order to maintain the size of conventional photovoltaic modules, it is best to adopt a method similar to Examples 4-6, that is, to place the diode strings and solar cell strings in parallel and overlapping. However, this may lead to new problems, because the substrate layer, conductive layer, and diodes that make up the diode strings all have a certain thickness, and the diodes also have a certain degree of hardness. Stacking them on the crystalline silicon solar cell may cause the crystalline silicon solar cell to crack or develop microcracks during the subsequent lamination process, which has certain potential risks.

[0045] To address the issue that overlapping diode strings may cause cracks or microcracks in crystalline silicon solar cells, the following backsheet pre-pressing method can be adopted: The following modifications are made to steps 5-7 of the above manufacturing method: 5.1, such as Figure 13 A backing plate 6 is laid on a flat surface with the air side of the backing plate facing down and the adhesive side facing up. A second adhesive layer 7 is stacked on the backing plate. Multiple diode strings 2 are placed at specific positions on the second adhesive layer, with the conductive layer and diodes of the diode strings facing down and the substrate layer facing up, exposing multiple windows 211 set on the substrate layer. The substrate layer of the diode strings can also be fixed with positioning tape 8 to prevent its position from shifting. When pasting the positioning tape 8, the position of the windows 211 should be avoided. 5.2 A release film is then applied to the diode string described above. The entire backplane and its carrier are then transferred to a laminator for vacuum high-temperature pre-pressing. After pre-pressing, the release film is removed to obtain the pre-pressed backplane component, as shown below. Figure 13 As shown; the process uses a second adhesive layer to bond the backplate and the diode string into a whole, so that the diode string is embedded in the second adhesive layer, and the substrate layer and the second adhesive layer are coplanar and maintain a certain degree of flexibility, while the conductive layer is exposed through the window; 5.3. The above-mentioned backplate pre-pressed part is inverted on the battery cell with conductive tape pasted in step 4 above, so that the air surface of the backplate faces upward, and the conductive layer at the window makes electrical contact with the conductive tape below one by one. Then the laminated part is transferred to the laminator for lamination. Finally, proceed to step 8 mentioned above to complete the production of the photovoltaic module. The finished photovoltaic module has almost no microcracks in the cells caused by diode strings.

[0046] When using the above-mentioned photovoltaic module manufacturing method, the first and second encapsulants must be made of the same material, such as any one of EVA, POE, EPE, PVB, SGP, etc. When using EVA, to control the consistency of the crosslinking degree of the first and second encapsulants, a step-by-step photovoltaic module encapsulation manufacturing method can also be used. This involves adding a front-panel pre-pressing method after step 4 of the aforementioned manufacturing method. Specifically, a release film is covered on the solar cells where the positive and negative electrodes are led out using conductive tape. Then, the front panel and its substrate are transferred to a laminator for pre-pressing. After lamination, the release film is removed to obtain the front-panel pre-pressing component, such as... Figure 12 As shown; adjust the lamination process parameters to control the crosslinking degree of EVA in the front and back pre-pressed components to be consistent, for example, both around 40%; then, invert the back pre-pressed component onto the front pre-pressed component, aligning them vertically, so that the conductive layer through the window in the back pre-pressed component makes contact and conduction with the conductive tape in the front pre-pressed component. If necessary, conductive adhesive can also be applied to the corresponding positions of the window to achieve reverse parallel connection between the diode string and the battery string; if needed, the positive and negative leads on the front pre-pressed component can also be passed through the back pre-pressed component; finally, send the stacked front and back pre-pressed components into the laminator for further lamination, controlling the crosslinking degree of EVA to reach approximately 85%-90% to complete the final bonding of the front and back pre-pressed components, and finally install the junction box. Whether to install a frame can be decided according to actual needs; this completes the manufacturing of the entire photovoltaic module. The process employed here involves first laminating and encapsulating the battery strings and diode strings into the front and back sheet pre-pressing components respectively, and then finally laminating and encapsulating them together. Experiments have shown that the cross-linking degree of the front and back films in the modules manufactured using this step-by-step encapsulation method is basically consistent, and the encapsulation reliability is basically consistent with that of the integrated encapsulation method. Furthermore, no obvious cracks or microcracks were observed in the battery cells of the photovoltaic modules.

[0047] Example 7 When the solar cells in photovoltaic modules use such Figure 15 When back-contacting solar cells as shown, based on the characteristics of back-contact solar cells, in order to simplify the processes such as connecting the solar cells in series and applying conductive tape, the structure and manufacturing method of the back-contact photovoltaic module with bypass diodes can also be as follows: S1. Prepare the intermediate circuit layer: The structure of the intermediate circuit layer is as follows: Figure 16As shown, the system includes a substrate layer 21. The substrate material can be selected from the aforementioned PET or fiberglass FR4, etc. The size of the substrate layer is slightly smaller than the size of the front and back panels. Conductive lines are fabricated on the substrate layer 21 using screen printing or PCB printing technology. The conductive lines include multiple sets of lead groups 213 and multiple sets of interconnecting lines 214. The layout of the lead groups 213 on the substrate layer is consistent with the series and parallel layout of the solar cells. Four solar cell positioning marks 218 are set around each lead group 213 to facilitate the positioning and placement of the solar cells. Each lead group 213 includes multiple positive electrode leads 2131 and negative electrode leads 2132. The diagram shows multiple positive and negative leads arranged in parallel and intersecting patterns. Each group of leads can be matched with the positive and negative grid lines of a back-contact solar cell. The positive and negative leads of adjacent lead groups 213 are connected by a set of interconnecting lines 214 to form a lead string. The two ends of the lead string are also connected to the bus line 215 by interconnecting lines 214. Each set of interconnecting lines 214 is connected to a lead line 216, and a diode connection terminal 217 is provided between adjacent lead lines 216. The conductive lines also include module positive and negative connection terminals 219. The layout of the conductive lines determines the series and parallel connection method between the solar cells in the final photovoltaic module.

[0048] S2. Place the battery cells and diodes on the aforementioned intermediate circuit layer: (e.g.) Figure 17 As shown, firstly, according to the positioning mark 218, the back contact cell 11 is aligned and placed on each group of lead wires 213, with the grid line side of the cell facing down and the grid-free side (light-receiving side) facing up. The positive and negative grid lines of the cell are electrically and fixedly connected to the positive and negative lead wires below it by welding or bonding. Next, a diode 22 is electrically and fixedly connected to each diode connection terminal 217. Multiple diodes are connected to form a diode string, and each diode is connected in reverse parallel with its corresponding cell. Finally, the positive and negative lead wires of the module are fixedly connected to the module positive and negative terminal connection terminal 219.

[0049] S3. Lamination and Delamination: Lay a backplate flat on a horizontal platform, lay a second interlayer on the backplate, lay the intermediate circuit layer (connecting the solar cells and diodes in S2) in the center of the second interlayer, lay a first interlayer on the intermediate circuit layer, lay a transparent front plate on the first interlayer, and lead the positive and negative leads of the module out of the front plate or backplate to obtain the laminated component; when the front plate is heavy glass, to prevent the solar cells from cracking, the above lamination order can also be reversed, that is, place the front plate, first interlayer, intermediate circuit layer, second interlayer, and backplate in sequence, and keep the light-receiving surface of the solar cells facing the front plate; wherein the dimensions of the backplate, front plate, first interlayer, and second interlayer are as follows: The dimensions of the laminated components are generally consistent, but the substrate layer of the intermediate circuit layer is slightly smaller than the other layers. For example, the substrate layer is 10-20mm smaller than the first and second adhesive layers on all four sides. Finally, the laminated components are placed in a high-temperature vacuum laminator for lamination. The two adhesive layers melt and fuse together, remaining transparent and encapsulating the substrate, cells, and diodes, while also bonding the front and back panels into a single unit. For aesthetic purposes, a shielding sheet can be placed over the diode strings in the laminated components. The shielding sheet is the same color as the substrate and back panel and is also encapsulated by the adhesive layer, so that the diodes are not visible on the front of the photovoltaic module after lamination. Finally, after trimming and installing the junction box, a back-contact photovoltaic module with bypass diodes is obtained.

Claims

1. A method for manufacturing an integrated photovoltaic module encapsulation, characterized in that, Includes the following steps: Step 1: Lay the transparent front panel horizontally on a flat surface; Step 2: Lay the first laminated layer flat on the front panel; Step 3: Place multiple battery strings that have been connected in series on the first interlayer, with the light-receiving surface of the battery cells in the battery strings facing down, and weld the battery strings in series or in parallel using busbars according to the set layout. Step 4: According to the set layout, use multiple conductive tapes to lead out all or part of the positive / negative electrodes of the battery cells, and bond the conductive tapes to the first interlayer. Step 5: Place multiple diode strings according to the set layout. The substrate of the diode string overlaps vertically with the conductive tape, and make the conductive layer at multiple windows on the substrate of the diode string overlap and make contact with multiple conductive tapes one by one. The diode string and the battery string are kept parallel and spaced apart or overlapped. Step 6: Lay the second laminated layer and the backing plate in sequence to obtain the laminated component; Step 7: Transfer the above-mentioned laminated parts to a vacuum high-temperature laminator for lamination to obtain the laminated parts; Step 8: Trim the laminate and install the junction box to obtain the finished photovoltaic module with multiple bypass diodes.

2. The photovoltaic module integrated packaging manufacturing method according to claim 1, characterized in that, The finished photovoltaic module contains m battery strings and p diode strings. Each battery string includes n battery cells connected in series, and each diode string includes q diodes connected in series. The n battery cells are aligned in the same direction and arranged in a straight line, and the q diodes are aligned in the same direction and arranged in a straight line. The diode strings are connected in antiparallel with one or more corresponding battery strings, and the diodes are connected in antiparallel with one or more corresponding battery cells. Where m, n, p, and q are all positive integers, m≥1, n≥2, p≤m, and q≤n.

3. The photovoltaic module integrated packaging manufacturing method according to claim 1, characterized in that, The diode string includes a long strip-shaped substrate layer on which multiple diodes are disposed. The positive and negative terminals of adjacent diodes are electrically connected through a conductive layer. The positive and negative terminals of two diodes at both ends are also led out through the conductive layer. The conductive layer is centrally disposed on the substrate layer and its width is smaller than that of the substrate layer.

4. The photovoltaic module integrated packaging manufacturing method according to claim 3, characterized in that, In the finished photovoltaic module, the conductive tape leads out the positive or negative electrode of the corresponding cell and makes a conductive connection with the negative or positive electrode of the corresponding diode.

5. The photovoltaic module integrated packaging manufacturing method according to claim 3, characterized in that, The substrate is an insulating substrate, and multiple windows are centrally spaced on the insulating substrate, which allow the conductive layer on the insulating substrate to conduct downwards.

6. The photovoltaic module integrated packaging manufacturing method according to claim 5, characterized in that, The substrate material at the window is not completely removed; instead, there are two substrate blades with a double-door structure. After the two substrate blades are folded over, the conductive layer is pressed underneath.

7. The photovoltaic module integrated packaging manufacturing method according to claim 1, characterized in that, The battery cell is a conventional battery cell with the positive and negative electrodes located on both sides of the battery cell. Conductive tape is pasted on the middle of the back of all or part of the battery cell and is bonded to the first interlayer.

8. The photovoltaic module integrated packaging manufacturing method according to claim 1, characterized in that, The battery cell is a back contact cell with both positive and negative electrodes located on the back side of the battery cell. Conductive tape is pasted on the interconnecting strips at both ends of all or part of the battery cells and on the interconnecting strips between the battery cells, and the conductive tape is bonded to the first interlayer.

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