I-V testing device for back contact battery

Abstract

The utility model provides a back contact battery I-V testing device, which comprises a testing mechanism and a pressing mechanism for pressing a battery above the testing mechanism, the testing mechanism comprises a bearing platform and a tester arranged on the bearing platform, a probe of the tester protrudes out of the upper surface of the bearing platform, and the probe is arranged on the bearing platform. The pressing mechanism comprises a frame and a plurality of parallel silk threads arranged on the frame, the cross section of each silk thread is triangular, one side of the frame is rotationally connected with the bearing table, and when the frame rotates to be horizontal, the bottom surfaces of the silk threads are in contact with the upper surface of the battery. According to the utility model, the triangular wire is arranged to press down the battery, and the pressure is uniformly controlled within an acceptable range through geometric stress dispersion, so that the hidden crack of the battery caused by local stress concentration is avoided; the light in the shielded area is directionally reflected to the surface of the adjacent cell through the side surface of the silk thread, so that the light compensation efficiency is high, and the current measurement deviation caused by shading is remarkably reduced.

Description

Technical Field

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

[0002] With the rapid development of the photovoltaic industry, the technological iteration and upgrading in the photovoltaic field are accelerating. Existing TOPCon and HJT cells are developing towards a combination of BC cells (TBC or HBC). BC cells, short for back contact cells, are based on IBC cells (interdigitated back contact cells). The biggest difference between BC cells and other crystalline silicon cell routes is that the emitter, surface field, and metal electrodes are all located on the back of the cell and distributed in an interdigitated pattern. There are no grid lines obstructing the front surface of the cell, maximizing the utilization of incident light, reducing optical losses, resulting in a larger effective power generation area and high conversion efficiency. Because there are no grid lines as electrodes on the front, it is difficult to extract electrical signals during testing, and it cannot be tested using upper and lower probe arrays like traditional cells. Based on the above reasons, current BC cell testing methods include: 1. Integrating positive and negative probe electrical signal acquisition points under the test platform and using vacuum adsorption to bring the cell into contact with the probes below for testing; 2. Based on the first method, eliminating vacuum adsorption and instead using high-transparency glass to press the cell down from above to bring it into contact with the probes below for testing.

[0003] In the existing first method, the quality of contact is greatly affected by vacuum pressure. Vacuum pressure is difficult to control within a suitable range; low vacuum pressure results in poor contact between the battery and the probe, leading to inadequate contact, while high vacuum pressure can easily damage the battery. The second testing method uses high-transmittance glass to press the battery down during testing. However, the glass is not completely transparent to light, which causes the actual light intensity received by the battery to be lower than the standard value. The light intensity can only be increased through calibration, but the light intensity calibration process itself introduces testing errors.

[0004] Therefore, it is necessary to design a back-contact battery IV testing device to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a back contact battery IV testing device with good contact effect and small test error.

[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 plurality of parallel wires disposed on the frame. The cross-section of the wires is triangular. One side of the frame is rotatably connected to the support platform. When the frame is rotated to a horizontal position, the bottom surface of the wires contacts the upper surface of the battery.

[0007] As a further improvement of this utility model, the cross-section of the silk thread is an isosceles triangle, and the vertex angle of the triangle is 14° < a < 20°.

[0008] As a further improvement of this utility model, the width of the base of the triangle is 0.1mm < w < 0.5mm.

[0009] As a further improvement of this utility model, the upper surface of the support platform is set in an arc along the length of the wire, and the arc of the arc is 3°-5°.

[0010] As a further improvement of this utility model, the support platform is also provided with a vacuum suction cup. When the frame is rotated to a horizontal position, the vacuum suction cup adsorbs the other side of the frame.

[0011] As a further improvement of this utility model, a reflective film is attached to both sides of the thread.

[0012] As a further improvement of this utility model, the reflective film is aluminum foil.

[0013] As a further improvement of this utility model, the spacing between the threads is 5-20cm.

[0014] As a further improvement of this utility model, the frame is provided with a V-shaped groove on the side facing the support platform, the wire is placed in the V-shaped groove and pressed against the frame by a pressure strip.

[0015] As a further improvement to this utility model, the material of the thread is gold.

[0016] As can be seen from the above technical solutions, the back contact battery IV testing device provided by this technical solution achieves significant performance improvement through several innovative designs, and the specific technical effects are as follows:

[0017] 1. The clamping mechanism provides uniform pressure and convenient operation: the base of the wire triangle (base edge 0.1~0.5mm) forms a surface contact with the upper surface of the battery, and the pressure is uniformly controlled within an acceptable range through geometric stress dispersion, avoiding battery microcracks caused by local stress concentration; when the frame is horizontally positioned, a vacuum suction cup provides stable locking, and the frame can be quickly opened and closed by rotation connection on the other side.

[0018] 2. Optical compensation optimization: The light from the blocked area is directionally reflected to the surface of the adjacent battery through the side of the wire, achieving high light compensation efficiency and significantly reducing the current measurement deviation caused by light blocking. Attached Figure Description

[0019] Figure 1 This is a side view schematic diagram of a back contact battery IV test device according to an embodiment of the present invention.

[0020] Figure 2 This is a top view of the clamping mechanism.

[0021] Figure 3 This is a schematic diagram of the installation of the wire and frame.

[0022] Figure 4 This is a schematic diagram of light reflection from the side of the silk thread. Detailed Implementation

[0023] 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.

[0024] 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 that presses the battery 1 onto the test mechanism 10.

[0025] The testing mechanism 10 includes a support platform 11 and a testing instrument 12 mounted on the support platform 11. The support platform 11 is used to support the battery 1, and the back side of the battery 1 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 1.

[0026] Please refer to Figure 2 and Figure 3 As shown, the clamping mechanism 20 includes a frame 21, a plurality of parallel wires 22, and a pressure strip 23 for fixing the wires to the frame. One side of the frame 21 is rotatably connected to the support platform 11 (e.g., connected by a hinge 13). The support platform 11 is also provided with a vacuum suction cup 14. When the frame 21 rotates to a horizontal position about the hinge 13, the vacuum suction cup 14 adheres to the other side of the frame 21.

[0027] The inner side of frame 21 has a rectangular cutout. Wires 22 are arranged in the cutout, with a spacing of 5-20cm. The upper surface of the support platform 11 is curved along the length of the wires 22, with an arc angle of 3°-5°. Adaptive stress adjustment: The curved surface design allows the battery to undergo micron-level elastic deformation during the pressing process, dynamically compensating for battery thickness tolerances and battery warpage, further improving the contact effect and stability between the battery electrodes and the probe.

[0028] The cross-section of wire 22 is triangular. When the frame is rotated to a horizontal position, the base of the wire contacts the upper surface of the battery. The cross-section of the wire is an isosceles triangle, with the vertex angle being 14° < a < 20°. The width of the base of the triangle is 0.1mm < w < 0.5mm.

[0029] A V-shaped groove is provided on the side of the frame 21 facing the support platform 11. The wire 22 is placed in the V-shaped groove and pressed against the frame 21 by the pressure strip 23. The wire 22 is pre-tightened and fixed in the V-shaped groove of the frame by the pressure strip 23 to prevent axial displacement of the wire 22, ensure that the wire 22 is in surface contact with the battery surface, and prevent the sharp edges of the wire from damaging the battery surface.

[0030] The material of wire 22 is gold. The ductility of gold allows it to be drawn into extremely fine wires, meeting the requirements of the testing device for small contact area and lightweight design; in addition, gold does not oxidize or sulfide under high temperature, high humidity, salt spray and other environments, completely avoiding the risk of reflectivity attenuation or contamination caused by traditional metals.

[0031] Reflective films are attached to both sides of the wire 22. The reflective film is preferably aluminum foil, with a thickness in the micrometer range. This allows it to completely adhere to the sides of the triangular wire, resulting in extremely low surface roughness and minimizing diffuse reflection loss. Please refer to... Figure 4 As shown, the reflective film on the side forms a closed light channel. The light from the area blocked by the wire 22 (the vertically downward dashed line represents the light when there is no wire blocking) is directionally reflected to the surface of the adjacent battery. The light compensation efficiency is high, and the current measurement deviation caused by light blocking is significantly reduced.

[0032] The terms used herein, such as "upper" and "lower," indicating spatial relative position, are for illustrative purposes to describe the relationship of one feature relative to another, as shown in the accompanying drawings. It is understood that, depending on the product's placement, these terms may be intended to include different orientations besides those shown in the figures, and should not be construed as limiting the claims.

[0033] Furthermore, 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 battery IV testing device, characterized in that: The device includes a testing mechanism and a clamping mechanism for pressing the battery onto the testing mechanism. The testing mechanism includes a support platform and a tester mounted on the support platform. The probe of the tester protrudes from the upper surface of the support platform. The clamping mechanism includes a frame and a plurality of parallel wires mounted on the frame. The cross-section of the wires is triangular. One side of the frame is rotatably connected to the support platform. When the frame is rotated to a horizontal position, the bottom surface of the wires contacts the upper surface of the battery.

2. The back contact battery IV test device as described in claim 1, characterized in that: The cross-section of the thread is an isosceles triangle, and the vertex angle of the triangle is 14° < a < 20°.

3. The back contact battery IV test device as described in claim 2, characterized in that: The width of the base of the triangle cross-section of the silk thread is 0.1mm < w < 0.5mm.

4. The back contact battery IV test device as described in claim 1, characterized in that: The upper surface of the support platform is arc-shaped along the length of the thread, and the curvature of the arc is 3°-5°.

5. The back contact battery IV test device as described in claim 1, characterized in that: The support platform is also equipped with a vacuum suction cup. When the frame is rotated to a horizontal position, the vacuum suction cup will adhere to the other side of the frame.

6. The back contact battery IV test apparatus as described in claim 1, characterized in that: Reflective films are attached to both sides of the thread.

7. The back contact battery IV test apparatus as described in claim 6, characterized in that: The reflective film is aluminum foil.

8. The back contact battery IV test apparatus as described in claim 1, characterized in that: The spacing between the threads is 5-20cm.

9. The back contact battery IV test apparatus as described in claim 1, characterized in that: The frame has a V-shaped groove on the side facing the support platform, and the wire is placed in the V-shaped groove and pressed against the frame by a pressure strip.

10. The back contact battery IV test apparatus as described in claim 1, characterized in that: The material of the thread is gold.

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