A method for leading out positive and negative electrodes of a thin film photovoltaic module

Abstract

The application relates to a method for leading out positive and negative electrodes of a thin-film photovoltaic module, which increases corresponding edge cleaning processes in conventional P1 scribing / P2 scribing / P3 scribing three processes, leads out the positive and negative electrodes without damaging the original structure of the thin-film photovoltaic module, and has no adverse effect on the packaging and detection of the thin-film photovoltaic module. The application can regionally clean the film layers of the thin-film photovoltaic module at different stages, connects the bus bars through the leading-out mode of the back electrode layer, realizes the required conduction, avoids the problems of abrasion, scratch and stress aging attenuation existing in the conventional contact type, and simultaneously reduces the cost of the bus bars by more than 80%.

Description

Technical Field

[0001] This invention belongs to the field of thin-film photovoltaic module manufacturing technology, and specifically relates to a method for leading out the positive and negative electrodes of a thin-film photovoltaic module. Background Technology

[0002] The current method for leading out the positive and negative electrodes of thin-film photovoltaic modules is mostly to directly attach the busbar to the positive and negative electrodes of the back electrode film layer of the module. During the alignment and placement process, the busbar will cause a certain degree of scratches and wear to the back electrode film layer of the thin-film photovoltaic module. Furthermore, after the thin-film photovoltaic module and the busbar are laminated at the same time, the main stress will be concentrated in the area where the busbar is located. After normal use and aging test, this will accelerate the performance degradation and functional decline of the positive and negative electrodes of the thin-film photovoltaic module, thereby causing a qualitative change in the performance and appearance of the thin-film photovoltaic module. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for leading out the positive and negative electrodes of a thin-film photovoltaic module, which avoids direct contact between the functional layer of the thin-film photovoltaic module and the busbar, reduces damage caused by friction between them, and also greatly reduces the material cost of the busbar. The thin-film photovoltaic module is more aesthetically pleasing and facilitates subsequent encapsulation processes.

[0004] This invention is implemented by providing a method for leading out the positive and negative electrodes of a thin-film photovoltaic module, comprising the following steps: Step 1: The substrate with the pre-formed front electrode layer includes a battery region in the middle and an edge region around the battery region. P1 lines are etched on the battery region to obtain multiple P1 grooves. The bottom of each P1 groove exposes the substrate. The multiple parallel P1 grooves divide the front electrode layer of the battery region into multiple independent sub-battery regions. Then, the front electrode layers at the top and bottom ends of the leftmost and rightmost sub-battery regions are removed to expose the substrate, resulting in the P1 edge clearing region. The P1 edge clearing region is located within the edge region. The width of the P1 edge clearing region is not greater than the width of the sub-battery region it belongs to and does not exceed the position of its adjacent P1 groove.

[0005] Step 2: Continue to prepare a light-absorbing layer on the surface of the front electrode layer. Make P2 lines on the light-absorbing layer to obtain multiple P2 grooves. Each P2 groove is close to the position of its corresponding P1 groove. The bottom of each P2 groove exposes the front electrode layer. Then remove the light-absorbing layers at the top and bottom ends of the leftmost and rightmost sub-cell areas to expose the front electrode layer, thus obtaining the P2 edge clearing area. The width of the P2 edge clearing area is not greater than the width of the corresponding P1 edge clearing area, and the height of the P2 edge clearing area is less than the height of the corresponding P1 edge clearing area. The length direction of the P2 edge clearing area leaves a gap with the position of the corresponding cell area.

[0006] Step 3: Continue to prepare the back electrode layer on the surface of the light-absorbing layer. Make P3 lines on the back electrode layer to obtain multiple P3 grooves. Each P3 groove is close to the position of its corresponding P2 groove. The bottom of each P3 groove exposes the light-absorbing layer. Set busbar lead-out areas in the upper and lower edge areas of the leftmost and rightmost sub-cell areas respectively. Except for the back electrode layer located in the busbar lead-out areas, remove the back electrode layer in other positions in the edge areas to expose the light-absorbing layer to obtain the P3 clear edge area. The width of the busbar lead-out area is not greater than the width of the corresponding P2 clear edge area, and its length is less than the width of the edge area. Set busbars as positive and negative electrode lead-out ends on the busbar lead-out areas respectively.

[0007] Compared with existing technologies, the method for leading out the positive and negative electrodes of thin-film photovoltaic modules in this invention adds a corresponding edge-cleaning process to the conventional three-step process of P1, P2, and P3 etching. A busbar lead-out area is set in the region where the edge area of ​​the back electrode layer is located. The busbar, serving as the positive and negative electrodes, is only connected to the back electrode layer within the busbar lead-out area, and is no longer directly connected to the back electrode layer in the cell area. This leads out the positive and negative electrodes without damaging the original structure of the thin-film photovoltaic module, and has no adverse effects on the encapsulation and testing of the thin-film photovoltaic module. This invention can perform regional cleaning of the film layers of thin-film photovoltaic modules at different stages. By changing the connection method between the back electrode layer and the busbar, the required conductivity for the positive and negative electrodes is achieved, avoiding the wear, scratches, and stress aging attenuation problems of conventional contact methods, while reducing the cost of the busbar by over 80%. Attached Figure Description

[0008] Figure 1 This is a schematic diagram illustrating the principle of step one of the thin-film photovoltaic module positive and negative electrode lead-out method of the present invention; Figure 2 This is a schematic diagram illustrating the principle of step two in the method for leading out the positive and negative electrodes of the thin-film photovoltaic module of the present invention; Figure 3 This is a schematic diagram illustrating the principle of step three in the method for leading out the positive and negative electrodes of the thin-film photovoltaic module according to the present invention. Detailed Implementation

[0009] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0010] Please refer to the following at the same time Figures 1 to 3 As shown, a preferred embodiment of the method for leading out the positive and negative electrodes of a thin-film photovoltaic module according to the present invention includes the following steps: Step 1: The substrate with the pre-formed front electrode layer 1 includes a battery region 2 in the middle and an edge region 3 around the battery region. Multiple P1 grooves 4 are formed on the battery region 2 using P1 scribe lines. The bottom of each P1 groove 4 exposes the substrate. The multiple parallel P1 grooves 4 divide the front electrode layer 1 of the battery region into multiple independent sub-battery regions 5. Then, the front electrode layer 1 at the top and bottom ends of the leftmost sub-battery region 5′ and the rightmost sub-battery region 5″ is removed to expose the substrate, resulting in a P1 edge clearing region 6. The P1 edge clearing region 6 is located within the edge region 3. The width of the P1 edge clearing region 6 is no greater than the width of the sub-battery region it belongs to and does not exceed the position of its adjacent P1 groove 4 to prevent it from affecting the adjacent second sub-battery region and causing a short circuit.

[0011] The purpose of setting up the P1 edge clearing area 6 is to completely remove the front electrode layer 1 here, so as to prevent the subsequent back electrode layer 11 from connecting with it and causing a short circuit.

[0012] like Figure 1 As shown, on the front electrode layer 1, the P1 clearing area 6 located above and below the leftmost sub-cell region 5′ is the starting end A and the ending end C of the positive electrode, respectively, and the P1 clearing area 6 located above and below the rightmost sub-cell region 5″ is the starting end B and the ending end D of the negative electrode, respectively.

[0013] Step 2: A light-absorbing layer 7 is prepared on the surface of the front electrode layer 1. Multiple P2 grooves 8 are obtained by scriber P2 lines on the light-absorbing layer 7. Each P2 groove 8 is located close to its corresponding P1 groove 4, and the bottom of each P2 groove 8 exposes the front electrode layer 1. The light-absorbing layers 7 at the top and bottom ends of the leftmost sub-cell region 5′ and the rightmost sub-cell region 5″ are then removed to expose the front electrode layer 1, resulting in P2 edge-clearing regions 9. The width of the P2 edge-clearing region 9 is no greater than the width of its corresponding P1 edge-clearing region 6, and the height of the P2 edge-clearing region 9 is less than the height of its corresponding P1 edge-clearing region 6. A gap 10 is left between the length of the P2 edge-clearing region 9 and the location of its corresponding cell region 2.

[0014] like Figure 2 As shown, on the light-absorbing layer 7, the P2 edge clearing regions 9 located above and below the leftmost sub-cell region 5′ are the starting end E and the ending end G of the positive electrode, respectively. The P2 edge clearing regions 9 located above and below the rightmost sub-cell region 5″ are the starting end F and the ending end H of the negative electrode, respectively. Both the P2 edge clearing regions 9 and the gap 10 are located within the edge region 3.

[0015] A gap 10 is provided, and a portion of the light-absorbing layer 7 is retained to cover the front electrode layer 1 of step one, preventing a short circuit between it and the subsequent back electrode layer 11.

[0016] Step 3: Continue to prepare the back electrode layer 11 on the surface of the light-absorbing layer 7, and perform P3 scribe lines on the back electrode layer 11 to obtain multiple P3 grooves 12. Each P3 groove 12 is located close to the position of its corresponding P2 groove 8, and the bottom of each P3 groove 12 exposes the light-absorbing layer 7. Busbar lead-out areas 13 are respectively set in the upper and lower edge regions located at the leftmost sub-cell region 5′ and the rightmost sub-cell region 5″. Except for the back electrode layer 11 in the busbar lead-out area 13, remove the back electrode layer 11 in other positions in the edge region 3 to expose the light-absorbing layer 7 to obtain the P3 clearing region 15. Only the busbar lead-out area 13 in the edge region 3 and the sub-cell region 5 in the cell region 2 retain the back electrode layer 11. The width of the busbar lead-out area 13 is not greater than the width of the corresponding P2 clearing region 9, and its length is less than the width of the edge region 3.

[0017] Busbars 14, serving as positive and negative electrode leads, are respectively provided on the busbar lead-out area 13 to complete the lead-out process of the positive and negative electrodes. The busbar lead-out area 13 is provided in the area where the edge region 3 of the back electrode layer 11 is located. The busbars 14, serving as positive and negative electrodes, are only connected to the back electrode layer 11 in the busbar lead-out area 13, and are no longer directly connected to the back electrode layer 11 in the battery region 2. This avoids direct contact between the back electrode layer 11 in the battery region 2 and the busbars 14, reducing the damage from mutual friction and stress aging attenuation, while also reducing the cost of the busbars 14 by more than 80%.

[0018] like Figure 3 As shown, on the back electrode layer 11, the busbar lead-out areas 13 located above and below the leftmost sub-cell region 5′ are the starting end I and the ending end K of the positive electrode, respectively, and the busbar lead-out areas 13 located above and below the rightmost sub-cell region 5″ are the starting end J and the ending end L of the negative electrode, respectively.

[0019] Specifically, the processing methods for the P1, P2, and P3 lines are laser etching or mask etching, respectively.

[0020] Specifically, the processing methods for the P1 edge clearing area 6, the P2 edge clearing area 9, and the busbar lead-out area 13 are laser etching or mask plate processing, respectively.

[0021] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for leading out the positive and negative electrodes of a thin-film photovoltaic module, characterized in that, Includes the following steps: Step 1: The substrate with the pre-formed front electrode layer includes a battery region in the middle and an edge region around the battery region. P1 lines are etched on the battery region to obtain multiple P1 grooves. The bottom of each P1 groove exposes the substrate. The multiple parallel P1 grooves divide the front electrode layer of the battery region into multiple independent sub-battery regions. Then, the front electrode layers at the top and bottom ends of the leftmost and rightmost sub-battery regions are removed to expose the substrate, resulting in the P1 edge clearing region. The P1 edge clearing region is located within the edge region. The width of the P1 edge clearing region is not greater than the width of the sub-battery region it belongs to and does not exceed the position of its adjacent P1 groove. Step 2: Continue to prepare a light-absorbing layer on the surface of the front electrode layer. Make P2 lines on the light-absorbing layer to obtain multiple P2 grooves. Each P2 groove is close to the position of its corresponding P1 groove. The bottom of each P2 groove exposes the front electrode layer. Then remove the light-absorbing layers at the top and bottom ends of the leftmost and rightmost sub-cell areas to expose the front electrode layer and obtain the P2 clearing area. The width of the P2 clearing area is not greater than the width of the corresponding P1 clearing area, and the height of the P2 clearing area is less than the height of the corresponding P1 clearing area. The length direction of the P2 clearing area leaves a gap with the position of the corresponding cell area. Step 3: Continue to prepare the back electrode layer on the surface of the light-absorbing layer. Make P3 lines on the back electrode layer to obtain multiple P3 grooves. Each P3 groove is close to the position of its corresponding P2 groove. The bottom of each P3 groove exposes the light-absorbing layer. Set busbar lead-out areas in the upper and lower edge areas of the leftmost and rightmost sub-cell areas respectively. Except for the back electrode layer located in the busbar lead-out areas, remove the back electrode layer in other positions in the edge areas to expose the light-absorbing layer to obtain the P3 clear edge area. The width of the busbar lead-out area is not greater than the width of the corresponding P2 clear edge area, and its length is less than the width of the edge area. Set busbars as positive and negative electrode lead-out ends on the busbar lead-out areas respectively.

2. The method for leading out the positive and negative electrodes of a thin-film photovoltaic module as described in claim 1, characterized in that, The P1, P2, and P3 lines are processed by laser etching or by masking, respectively.

3. The method for leading out the positive and negative electrodes of a thin-film photovoltaic module as described in claim 1, characterized in that, The processing methods for the P1 edge clearing area, P2 edge clearing area, and busbar lead-out area are laser etching or masking, respectively.

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