Photovoltaic soldering ribbon with twisted carbon fibers

Abstract

The application provides a photovoltaic welding strip with twisted carbon fibers, which comprises a copper strip layer, a solder layer, friction particles and carbon fibers, the copper strip layer constitutes a strip body, the carbon fibers are arranged in parallel and embedded in the copper strip layer, the surface of the carbon fibers is provided with the friction particles, and the carbon fibers have a twist degree; the carbon fibers are compounded into the copper strip, the thermal expansion coefficient of the carbon fibers is far smaller than that of copper and solder, so that the carbon fibers can play a good anchoring role, that is, the role of inhibiting metal thermal deformation; meanwhile, the friction particles can well connect and fix the mutual deformation between the carbon fibers and the copper strip, the anchoring role of the carbon fibers is strengthened, the carbon fibers have a twist degree, the surface of the carbon fibers is roughened, the carbon fibers can be better anchored with the copper strip through the friction particles, the carbon fibers with the twist degree are in a tensile state, have a shrinkage stress, and can well resist the elongation deformation of the copper strip in the welding process.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and more particularly to a photovoltaic welding ribbon composited with twisted carbon fiber. Background Technology

[0002] Due to the significant difference in thermal expansion coefficients between the metal and the solar cell, the photovoltaic welding ribbon will bring thermal expansion and contraction stress to the solar cell. In severe cases, it can cause the solar cell to bend and deform. During the alternating hot and cold periods of day and night, the periodic stress brought by the photovoltaic welding ribbon to the solar cell is a destructive form of thermal fatigue damage. Therefore, it is necessary to avoid thermal fatigue cracking of the photovoltaic welding ribbon. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention attempts to overcome the above defects. Therefore, the present invention provides a photovoltaic welding ribbon with twisted carbon fiber, which reduces the thermal fatigue damage of solar cells caused by the thermal expansion of metal through the anchoring effect of carbon fiber.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a photovoltaic ribbon with twisted carbon fiber, comprising a copper strip layer, a solder layer, friction particles, and carbon fiber, wherein the copper strip layer forms the ribbon body, the carbon fiber is arranged in parallel and embedded in the copper strip layer, the surface of the carbon fiber is provided with friction particles, the carbon fiber has twist, and the friction particles are silica powder with an average size of 0.5 micrometers to 20 micrometers and sharp edges.

[0005] Furthermore, the diameter of the carbon fiber is 0.01-0.05 mm.

[0006] Furthermore, the thickness of the copper strip layer is 0.035-0.2 mm, and the width of the copper strip layer is 0.2-1 mm.

[0007] Furthermore, the twist of the carbon fiber is 80-850 twists / 10cm.

[0008] Furthermore, the carbon fiber with twist is in a stretched state with a stretch rate of 10%-30%.

[0009] Furthermore, the thickness of the solder layer is 0.01-0.03 mm.

[0010] Compared with the prior art, the present invention has the following beneficial effects: Incorporating carbon fiber into copper strips provides excellent anchoring, as the coefficient of thermal expansion of carbon fiber is much lower than that of copper and solder. This effectively suppresses thermal deformation of the metal. Simultaneously, the friction particles effectively connect and fix the mutual deformation between the carbon fiber and copper strip, strengthening the anchoring effect of the carbon fiber. The twist of the carbon fiber roughens its surface, further enhancing anchoring with the copper strip through the friction particles. The twisted carbon fiber, under tension, exhibits shrinkage stress, effectively resisting the elongation deformation of the copper strip during welding. Furthermore, the carbon fiber increases the tensile rigidity of the solder strip, improving its mechanical strength. Most importantly, using carbon fiber as a deformation-resistant skeleton reduces the thermal fatigue damage to solar cells caused by metal thermal expansion. Attached Figure Description

[0011] Figure 1 : This is a cross-sectional view of this patent; In the diagram: 1. Copper strip layer; 2. Solder layer; 3. Friction particles; 4. Carbon fiber. Detailed Implementation

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] like Figure 1 As shown, the present invention provides a photovoltaic solder ribbon with twisted carbon fiber, comprising a copper strip layer 1, a solder layer 2, friction particles 3, and carbon fiber 4. The copper strip layer 1 forms the ribbon body, and the carbon fiber 4 is arranged in parallel and embedded in the copper strip layer 1. The surface of the carbon fiber 4 is provided with friction particles 3, which are silica powder with an average size of 0.5 micrometers to 20 micrometers and sharp edges. The carbon fiber 4 has twist, with a diameter of 0.01-0.05 mm. The thickness of the copper strip layer 1 is 0.035-0.2 mm, and the width of the copper strip layer is 0.2-1 mm. The twist of the carbon fiber 4 is 80-850 twists / 10 cm. The twisted carbon fiber 4 is in a stretched state with a stretch rate of 10%-30%. The thickness of the solder layer is 0.01-0.03 mm.

[0014] Working principle: Carbon fiber 4 is incorporated into the copper strip. Since the coefficient of thermal expansion of carbon fiber 4 is much smaller than that of copper and solder, it provides excellent anchoring, thus suppressing thermal deformation of the metal. Simultaneously, the friction particles 3 effectively connect and fix the mutual deformation between the carbon fiber 4 and the copper strip, strengthening the anchoring effect of the carbon fiber 4. The twist of the carbon fiber 4 roughens its surface, allowing for better anchoring with the copper strip via the friction particles 3. The twisted carbon fiber 4 is in a tensile state, exhibiting contraction stress, which effectively counteracts the elongation deformation of the copper strip during welding. Furthermore, carbon fiber 4 increases the tensile rigidity of the solder strip, enhancing its mechanical strength. Most importantly, using carbon fiber 4 as an anti-deformation skeleton reduces the thermal fatigue damage to the solar cell caused by metal thermal expansion. Example

[0015] The carbon fiber spool rotates continuously, causing the pulled carbon fiber to twist. Two feed rollers straighten the carbon fiber and stretch the twisted carbon fiber by 10% to 15%. Copper foil is spirally wound around the carbon fiber in the middle. Above the contact point between the copper foil and the carbon fiber, there is a hopper containing silica powder. The falling silica powder adheres tightly to the surface of the carbon fiber and is wrapped by the copper foil. Then, the composite line of carbon fiber wrapped with copper foil is drawn into and transported to the electroplating bath, so that a layer of copper is electroplated on the surface of the copper foil. Then, it is drawn into the heating furnace area, which is protected by nitrogen. The furnace temperature reaches the annealing temperature of copper. Then, it is drawn into the heating furnace area and flattened by rollers into a flat wire. Then, it is drawn into the hot-dip tin plating bath, cooled by an air gun, and finally wound up. Example

[0016] Two wire feed rollers straighten the copper wire. Interlocking convex and concave rollers transform the cross-section of the copper wire into a concave shape. Twisted and stretched carbon fibers are embedded in the concave area. Above the carbon fibers embedded in the concave area is a hopper containing silica powder. The falling silica powder also falls into the concave area. Then, another pair of convex and concave rollers transforms the concave cross-section copper wire into a circular cross-section composite wire. It is then pulled into and sent to the heating furnace area, which is protected by nitrogen. The furnace temperature reaches the annealing temperature of copper. It is then pulled into the furnace and flattened by rollers to become a flat wire. It is then pulled into the hot-dip tin plating bath, cooled by an air gun, and finally wound up.

[0017] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A photovoltaic welding ribbon composited with twisted carbon fiber, characterized in that: It includes a copper strip layer (1), a solder layer (2), friction particles (3) and carbon fiber (4). The copper strip layer (1) forms a strip body. The carbon fiber (4) is arranged in parallel and embedded in the copper strip layer (1). The surface of the carbon fiber (4) is provided with friction particles (3). The carbon fiber (4) has twist. The friction particles (3) are silica powder with an average size of 0.5 micrometers to 20 micrometers and sharp edges.

2. The photovoltaic welding ribbon with composite twisted carbon fiber according to claim 1, characterized in that: The carbon fiber has a diameter of 0.01-0.05 mm.

3. The photovoltaic welding ribbon with composite twisted carbon fiber according to claim 1, characterized in that: The thickness of the copper strip layer (1) is 0.035-0.2 mm, and the width of the copper strip layer is 0.2-1 mm.

4. A photovoltaic welding ribbon with composite twisted carbon fiber according to claim 1, characterized in that: The carbon fiber (4) has a twist of 80-850 twists / 10cm.

5. A photovoltaic welding ribbon with composite twisted carbon fiber according to claim 1, characterized in that: The carbon fiber (4) with twist is in a stretched state with a stretch rate of 10%-30%.

6. A photovoltaic welding ribbon with composite twisted carbon fiber according to claim 1, characterized in that: The thickness of the solder layer is 0.01-0.03 mm.

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