CN102544144A - Solar module welding strip - Google Patents

Abstract

The invention discloses a solar module welding strip, which has at least two layers of metal foils, an adhesive layer with a conductive function that can bond the metal foils together is arranged between two adjacent layers of metal foils, and the outermost layer of metal foils is Tin alloy layers are respectively provided on the outer surfaces of each. The invention can reduce the internal stress of the solar cells after welding, reduce the hidden cracks of the solar modules and improve the yield.

Description

Solar Module Ribbon

technical field

The invention relates to the technical field of solar energy, in particular to a solar module welding ribbon.

Background technique

The solar cells are connected by solar module ribbons. The common solder strip structure consists of three parts, the middle is a copper strip, and the upper and lower layers are tin alloy or silver layers, whose thickness accounts for less than 25% of the total thickness. Due to the good welding performance and electrical conductivity of the ribbon, each solar battery sheet forms a complete electrical path after connection, and the current and voltage are transmitted through the ribbon. However, in the actual use process, as the thickness of the battery sheet becomes thinner, the thermal expansion coefficient between the copper strip and the battery sheet differs greatly, and the two generate a lot of stress during the cooling process after welding, resulting in a high rate of cell fragmentation , there are more hidden cracks in the later components.

Contents of the invention

The technical problem to be solved by the present invention is: to overcome the deficiencies in the prior art, to provide a solar module soldering strip which reduces the internal stress of the solar battery sheet after welding, reduces the hidden cracks of the solar module and improves the yield.

The technical solution adopted by the present invention to solve the technical problem is: a solar module soldering strip, which has at least two layers of metal foils, and a conductive film that can bond the metal foils together is arranged between the two adjacent layers of metal foils. The functional bonding layer is provided with a tin alloy layer on the outer surface of the outermost metal foil respectively.

The number of metal foil layers is six, and the metal foil is copper foil or aluminum foil.

The beneficial effect of the present invention is that: the solar module soldering strip provided by the present invention has multi-layer metal foil, which produces multi-layer temperature difference and absorbs multi-layer stress, so that the stress applied to the battery sheet is much smaller than that of a single-layer metal foil with the same thickness. The stress of the belt reduces the deformation of the cell sheet, reduces the fragmentation rate of the solar cell sheet, reduces the cracks of the solar module, and improves the yield.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is a structural schematic diagram of the present invention.

In the figure 1. Metal foil 2. Adhesive layer 3. Tin alloy layer

Detailed ways

The present invention will now be further described in conjunction with the accompanying drawings and preferred embodiments. These drawings are all simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, so they only show the configurations related to the present invention.

A solar module welding ribbon as shown in Figure 1 has at least two layers of metal foils 1, and an adhesive layer 2 with a conductive function that can bond the metal foils 1 together is arranged between adjacent two layers of metal foils 1 , the outer surfaces of the outermost metal foil 1 are respectively provided with tin alloy layers 3 .

Embodiment 1: The solar module welding ribbon has six layers of metal foil 1, the metal foil 1 is preferably copper foil with a thickness of 0.02mm, and the adhesive layer 2 is a conductive adhesive. Apply a layer of conductive adhesive evenly on one side of the first layer of copper foil, stick the second layer of copper foil on it, then apply a layer of conductive adhesive on the second layer of copper foil, and stick the third layer of copper foil on it, The fourth layer, the fifth layer, and the sixth layer in sequence. After the six layers of copper foil are pasted, pressurize and heat the equipment to bond the six layers of copper foil together. After cleaning the surface, immerse it in a tin bath. The temperature of the tank is controlled at 240 degrees, and the surface of the solder strip is uniformly dip-coated with a layer of tin alloy layer 3 when passing through the molten alloy plating solution.

Embodiment 2: The solar module welding ribbon has six layers of metal foil 1, the metal foil 1 is preferably four layers of copper foil with a thickness of 0.02 mm and two layers of aluminum foil with a thickness of 0.02 mm, and the adhesive layer 2 is a conductive adhesive. Apply a layer of conductive adhesive evenly on one side of the first layer of copper foil, stick the second layer of copper foil on it, then coat a layer of conductive adhesive on the second layer of copper foil, stick the first layer of aluminum foil on it, and then It is the second layer of aluminum foil, the third layer of copper foil, and the fourth layer of copper foil. After the six layers of metal foil 1 are pasted, pressurize and heat the equipment to bond the six layers of metal foil 1 together, and then clean the surface , immersed in the tin bath, the temperature of the tin bath is controlled at 240 degrees, and the surface of the solder strip is uniformly dip-coated with a layer of tin alloy layer 3 when passing through the molten alloy plating solution.

The above-mentioned tin alloy layer 3 can also be immersion-plated with a silver layer by means of silver plating.

During the cooling process of the solar module ribbon after welding with the battery sheet, the outermost metal foil 1 is in contact with the air, and is cooled first. Compared with the first layer of metal foil 1, the temperature of the second layer is higher, and the first layer The metal foil 1 shrinks when it cools, and the second layer is stressed, but due to the small temperature difference and the buffer of the intermediate adhesive layer 2, the stress is much smaller. In the same way, through the third layer, the fourth layer, etc., until the layer that is pasted into the battery sheet at the end, the last layer cools down and shrinks, and the stress is applied to the battery sheet. The stress on the sheet is much smaller than the stress of a single-layer metal ribbon with the same thickness, the deformation of the cell sheet is reduced, the fragmentation rate of the solar cell sheet is reduced, and the hidden cracks of the solar module are reduced.

The above-mentioned embodiments are only to illustrate the technical conception and characteristics of the present invention. Substantial equivalent changes or modifications shall fall within the protection scope of the present invention.

Claims (3)

1. A solar module soldering strip, characterized in that: it has at least two layers of metal foils (1), and the metal foils (1) can be bonded together between the two adjacent layers of metal foils (1). An adhesive layer (2) having a conductive function, and tin alloy layers (3) are respectively provided on the outer surfaces of the outermost metal foil (1). 2. The solar module welding ribbon according to claim 1, characterized in that: said metal foil (1) has six layers. 3. The solar module welding ribbon according to claim 1, characterized in that: said metal foil (1) is copper foil or aluminum foil.

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