Back contact cell i-v testing apparatus

Abstract

The utility model provides a kind of back contact battery I-V testing device, it includes test mechanism and the compacting mechanism of battery compression in the test mechanism above, test mechanism includes bearing station and is set on the tester of bearing station, the probe of tester protrudes from the upper surface of bearing station, compacting mechanism includes frame and is set on the transparent pressboard of frame, transparent pressboard includes the frame portion of four around, multiple parallelly arranged strip portion and openwork, two ends of strip portion are fixedly connected with frame portion, strip portion corresponds with the main grid line position of battery, the width of strip portion is greater than the width of main grid line, openwork is formed between strip portion and frame portion.The probe of the compacting mechanism of the utility model cooperates with test mechanism, not only can ensure that test measuring needle and battery main grid line are in full contact, can form stable electrical connection, reduce contact resistance, but also can reduce shading, provide reliable current transmission path for battery I-V test, effectively guarantee the accuracy and stability of test data.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic module testing equipment technology, and in particular to a back contact cell IV testing device. Background Technology

[0002] With the rapid development of the photovoltaic industry and the accelerating pace of technological iteration, existing TOPCon and HJT cells are evolving towards integration with BC cells (TBC or HBC). BC cells, or back-contact cells, are based on IBC cells (interdigitated back-contact cells). Their significant difference from other crystalline silicon cell approaches lies in the fact that the emitter, surface field, and metal electrodes are all located on the back of the cell in an interdigitated pattern, with no grid lines obstructing the front surface. This unique structure allows BC cells to maximize the utilization of incident light, reduce optical losses, and expand the effective power generation area, thus achieving higher conversion efficiency.

[0003] However, the absence of grid-line electrodes on the positive surface of BC batteries makes it difficult to extract electrical signals during testing using upper and lower probe arrays, unlike traditional batteries. Currently, there are two main testing solutions to address this issue: One is to integrate positive and negative probe signal acquisition points under the test platform, using vacuum adsorption to bring the battery into contact with the probes for testing. However, the contact effect between the battery and probes in this solution is greatly affected by vacuum pressure; excessive pressure can damage the battery, while insufficient pressure leads to poor contact. The second solution, based on the first, uses high-transmittance glass (approximately 95% transmittance) to press the battery into contact with the probes. However, insufficient glass transmittance will cause the actual light intensity received by the battery to be lower than the standard value, requiring light intensity calibration. This will cause an imbalance in the proportion of light intensity across different wavelengths, introducing testing errors. Furthermore, the hard contact between the glass and the textured surface of the battery can also cause contact damage.

[0004] Therefore, it is necessary to design a back-contact battery IV test device to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a back-contact battery IV test device that effectively improves the accuracy and reliability of battery testing and has a simple structure.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a back contact battery IV testing device, comprising a testing mechanism and a pressing mechanism for pressing the battery onto the testing mechanism. The testing mechanism includes a support platform and a testing instrument disposed on the support platform. The probe of the testing instrument protrudes from the upper surface of the support platform. The pressing mechanism includes a frame and a transparent pressure plate disposed on the frame. The transparent pressure plate includes a frame portion around its perimeter, a plurality of parallel strip portions and a hollow portion. The two ends of the strip portions are fixedly connected to the frame portion. The strip portions correspond to the positions of the main grid lines of the battery. The width of the strip portions is greater than the width of the main grid lines. The hollow portion is formed between the strip portions and the frame portion.

[0007] As a further improvement of this utility model, each of the strip-shaped portions is provided with an elastic buffer strip on the side facing the battery. When the pressing mechanism presses the battery onto the testing mechanism, the elastic buffer strip contacts the battery, and the light transmittance of the elastic buffer strip is ≥95%. The elastic buffer strip can play a buffering role during the pressing process, avoiding physical damage such as scratches and breaks on the battery surface due to excessive pressure, effectively protecting the battery integrity, reducing the battery loss rate during the test, and extending the battery life. It is especially suitable for back contact battery testing where surface quality requirements are high.

[0008] As a further improvement of this utility model, the thickness of the elastic buffer strip is 150-300μm.

[0009] As a further improvement of this utility model, the material of the elastic buffer strip is EVA film.

[0010] As a further improvement of this utility model, the thickness of the strip portion is 150-300μm.

[0011] As a further improvement of this utility model, the width of the strip portion is 2-5mm.

[0012] As a further improvement to this invention, the strip-shaped portion is made of glass, and its light transmittance is ≥95%. The high light transmittance of the strip-shaped portion and the elastic buffer strip ensures the consistency of the testing conditions.

[0013] As a further improvement of this utility model, the upper surface of the support platform is provided with a plurality of limiting blocks for restricting the position of the clamping mechanism, and the limiting blocks abut against the four sides of the frame respectively. The setting of the limiting blocks allows the clamping mechanism to be in place in one go, and the strip part can be accurately positioned to the location of the main grid line, making the testing operation simple and fast.

[0014] As can be seen from the above technical solutions, the strip-shaped part in the clamping mechanism of this utility model corresponds to the position of the main grid line of the battery, and in conjunction with the probe protruding from the support platform in the testing mechanism, it can ensure that the test probe and the main grid line of the battery are in full contact, forming a stable electrical connection and reducing contact resistance. The clamping mechanism provides a reliable current transmission path for battery IV testing, effectively ensuring the accuracy and stability of test data. The hollowed-out design can minimize the impact of light obstruction caused by the clamping mechanism, ensuring that the battery is under illumination conditions close to the actual working environment, so that the test results more realistically reflect the photoelectric performance of the battery in actual applications, improving the validity and reliability of the test results. On the other hand, the hollowed-out part can reduce the overall weight of the transparent pressure plate, making operation easier. In addition, the hollowed-out part increases air circulation, which helps the battery dissipate heat during the test and prevents performance fluctuations caused by battery heating from affecting the test results. Furthermore, the hollowed-out part can also prevent the battery from adhering to the pressure plate during the test, making it easy to remove the clamping mechanism after the test is completed. Attached Figure Description

[0015] Figure 1 This is a front view schematic diagram of a back contact battery IV testing device according to an embodiment of the present invention.

[0016] Figure 2 for Figure 1 A top view of the IV test apparatus for the back contact battery.

[0017] Figure 3 for Figure 1 Cross-sectional view of the central clamping mechanism. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. The accompanying drawings are for illustrative purposes only, aiming to assist in understanding the structure, principle, and workflow of this utility model. It should be clarified that the dimensions and proportions between components shown in the drawings are schematic representations and do not represent the precise dimensions and proportions of the actual product. Dimensions and proportions in actual applications will be adjusted and determined according to specific implementation requirements, and the aforementioned schematic representations do not constitute any limitation on the scope of protection of this patent.

[0019] Please refer to Figure 1 As shown, this utility model provides a back contact battery IV test device, which includes a test mechanism 10 and a pressing mechanism 20 for pressing the battery 10000 onto the test mechanism 10.

[0020] The testing mechanism 10 includes a support platform 11 and a testing instrument 12 disposed on the support platform 11. The support platform 11 is used to support the battery 100, and the back side of the battery 100 is in contact with the upper surface of the support platform 11 under the action of a clamping mechanism. The probe of the testing instrument 12 protrudes from the upper surface of the support platform 11 to contact the back electrode of the battery 100.

[0021] Please participate together Figure 2 and Figure 3 As shown, the clamping mechanism 20 includes a frame 21 and a transparent pressure plate 22 disposed on the frame 21. The frame 21 is a rectangular metal frame. The transparent pressure plate 22 is rectangular in shape and is disposed inside the frame 21.

[0022] The transparent pressure plate 22 includes a frame 221 around its perimeter, multiple parallel strip sections 222, and a cutout section 223. The two ends of the strip sections 222 are fixedly connected to the frame 221. The strip sections 222 correspond to the positions of the main grid lines of the battery 100, and the width of the strip sections 222 is greater than the width of the main grid lines. A cutout section 223 is formed between the strip sections 222 and the frame 221. The thickness of the strip sections 222 is 150-300 μm, and the width is 2-5 mm. The strip sections 222 are made of glass with a light transmittance ≥95%.

[0023] In this embodiment, the transparent pressure plate 22 is integrally formed, that is, the transparent pressure plate 22 is a glass plate in its entirety, and the glass at the hollowed-out positions is cut off at predetermined positions, leaving only the frame portion 221 around the perimeter and the strip portion 222 inside the frame portion 221. In other embodiments, the strip portion and the frame portion can also be set separately, and the material of the frame portion can be the same as or different from that of the strip portion, which is not limited here.

[0024] Please refer to Figure 1 and Figure 3 As shown, each strip 222 has an elastic buffer strip 23 on the side facing the battery 100. When the pressing mechanism 20 presses the battery 100 onto the testing mechanism 10, the elastic buffer strip 23 contacts the battery 100, preventing the transparent pressure plate 22 from directly contacting the battery 100. The elastic buffer strip 23 can play a buffering role during the pressing process, avoiding physical damage such as scratches and breaks on the battery surface due to excessive pressure, effectively protecting the battery integrity, reducing the battery loss rate during the test, and extending the battery life. It is especially suitable for back contact battery testing where surface quality requirements are high.

[0025] The elastic buffer strip 23 has a light transmittance of ≥95%, a thickness of 150-300μm, and a width consistent with the strip portion 222. The elastic buffer strip is preferably made of EVA film, which not only has good elasticity and extremely high light transmittance, but is also removable. After several tests, if the light transmittance of the elastic buffer strip 23 decreases beyond an acceptable range, a new elastic buffer strip can be replaced to maintain the overall light transmittance of the transparent pressure plate.

[0026] The upper surface of the support platform 11 is also provided with multiple limiting blocks 111 for limiting the position of the clamping mechanism 20. The multiple limiting blocks 111 abut against the four sides of the frame 21 respectively. The setting of the limiting blocks 111 allows the clamping mechanism 20 to be in place in one go, and the strip part 222 can be accurately positioned to the location of the main grid line, making the testing operation simple and fast.

[0027] The test operation procedure of the back contact battery IV test device in this embodiment is as follows: Check the integrity of the testing device: Carefully check whether all components of the testing mechanism 10 and the clamping mechanism 20 are complete and intact. Pay special attention to whether the light transmittance of the elastic buffer strip 23 is ≥95%. If its light transmittance decreases to an unacceptable range, replace it with a new elastic buffer strip in time to ensure the accuracy of the test and the protection effect on the battery surface. Clean the device surface: Use a clean, lint-free cloth and a special cleaning agent to clean the upper surface of the support platform 11, the surface of the transparent pressure plate 22, and the back of the battery 100 to be tested, to remove dust, impurities and stains from the surface, so as to avoid affecting the accuracy of the test results and the good contact between the battery and the probe.

[0028] Connect the power supply: Connect the tester 12 to a stable power source and turn on the power switch of the tester. Perform the initialization settings according to the tester's operation manual to ensure that the tester is in normal working condition. Battery placement: Place the back contact battery 100 to be tested smoothly on the support platform 11, ensuring that the back of the battery is in contact with the upper surface of the support platform 11, and align the main grid line with the probe row. Install the clamping mechanism: Align the frame 21 of the clamping mechanism 20 with the limiting block 111 on the support platform 11, and slowly lower the frame 21 so that the four sides of the frame 21 are in close contact with the limiting block 111, ensuring that the strip portion 222 of the transparent pressure plate 22 is accurately positioned at the location of the battery main grid line. At this time, the elastic buffer strip 23 contacts the battery surface. Start the clamping operation: According to the device design, start the clamping mechanism 20 manually or by other means, so that the frame drives the transparent pressure plate 22 to gradually press the battery 100 down until the preset clamping force is reached (the clamping force can be applied by the weight of the clamping mechanism itself, or the pressure can be adjusted by evenly setting counterweights on the frame), to ensure that the back electrode of the battery 100 is in full and stable contact with the probe of the tester 12. Testing: After confirming good contact between the battery and the probe and appropriate clamping force, start the IV test program on the operating interface of the tester 12. The tester 12 will perform voltage-current characteristic tests on the battery according to preset parameters, automatically collect and record test data, and simultaneously display the test curve and relevant parameters on the tester's display screen in real time.

[0029] Please refer to Table 1, which compares the test results of this embodiment's back-contact battery IV test device on 200 battery cells with the test results of an existing all-glass clamping mechanism test device. It can be seen that compared with the test results of the existing test device, the test device of this embodiment significantly reduces the contact resistance fluctuation value and the breakage rate. Furthermore, regarding the reliability of the test device, by measuring the light transmittance of the strip section and the elastic buffer strip after multiple consecutive tests, it can be seen that the clamping mechanism of this embodiment can be stably measured multiple times, demonstrating high reliability.

[0030] Table 1. Comparison of test results:

[0031] The above embodiments are only used to illustrate the present utility model and are not intended to limit the technical solutions described in the present utility model. The understanding of this specification should be based on those skilled in the art. Although the present utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications or equivalent substitutions to the present utility model. All technical solutions and improvements that do not depart from the spirit and scope of the present utility model should be covered within the scope of the claims of the present utility model.

Claims

1. A back contact cell I-V test apparatus, characterized by: The device includes a testing mechanism and a pressing mechanism for pressing the battery onto the testing mechanism. The testing mechanism includes a support platform and a testing instrument mounted on the support platform. The probe of the testing instrument protrudes from the upper surface of the support platform. The pressing mechanism includes a frame and a transparent pressure plate mounted on the frame. The transparent pressure plate includes a frame portion around its perimeter, multiple parallel strip portions, and a hollow portion. The two ends of the strip portions are fixedly connected to the frame portion. The strip portions correspond to the positions of the main grid lines of the battery. The width of the strip portions is greater than the width of the main grid lines. The hollow portion is formed between the strip portions and the frame portion.

2. The back contact cell I-V test apparatus of claim 1, wherein: Each of the strip sections has an elastic buffer strip on the side facing the battery. When the pressing mechanism presses the battery onto the testing mechanism, the elastic buffer strip contacts the battery, and the light transmittance of the elastic buffer strip is ≥95%.

3. The back contact cell I-V test apparatus of claim 2, wherein: The thickness of the elastic buffer strip is 150-300μm.

4. The back contact cell I-V test apparatus of claim 2, wherein: The elastic buffer strip is made of EVA film.

5. The back contact cell I-V test apparatus of claim 1, wherein: The thickness of the strip portion is 150-300 μm.

6. The back contact cell I-V test apparatus of claim 1, wherein: The width of the strip is 2-5mm.

7. The back contact cell I-V test apparatus of claim 1, wherein: The strip is made of glass, and its light transmittance is ≥95%.

8. The back contact cell I-V test apparatus of claim 1, wherein: The upper surface of the support platform is provided with a plurality of limiting blocks for restricting the position of the clamping mechanism, and the limiting blocks abut against the four sides of the frame respectively.

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