CN111477713A - Welding strip for IBC photovoltaic module - Google Patents

Abstract

The purpose of the present invention is to disclose a welding tape for IBC photovoltaic modules, comprising a base material and a coating covering the surface of the base material, the base material is provided with stress buffer grooves, and the stress buffer grooves are distributed in the The length direction and width direction of the substrate; compared with the prior art, the coating adopts three materials, Sn, Bi and Pb, with a melting point of 160-180°C, which can realize low-temperature welding and has good tensile force, which can solve the problem of IBC. The insulating paste of the battery is not resistant to high temperature; the substrate contains a stress buffer tank, coupled with low-temperature welding, which can effectively reduce the problem of stress concentration and easy cracking during welding of the IBC battery; the vacuum evaporation method is used to coat the coating, The film forming speed is fast, the quality is high, and the thickness can be precisely controlled, so as to achieve the purpose of the present invention.

Description

A welding tape for IBC photovoltaic modules

technical field

The invention relates to a welding tape for photovoltaic modules, in particular to a welding tape for IBC photovoltaic modules.

Background technique

As a kind of low-carbon renewable energy, the solar energy industry is gaining more and more attention worldwide. At present, the most important application of solar energy is photovoltaic power generation.

Solar photovoltaic modules connect cells in series through welding strips. The quality of welding strips directly affects the output efficiency and fragmentation rate of current in the production of photovoltaic modules, and also has a great impact on the cost and output power of photovoltaic modules. It is an important component of photovoltaic modules. The main reason for the breakage of the crystalline silicon cell during the welding process is that the silicon wafer will rapidly decrease from 250 °C to room temperature in a short time during welding, and the severe temperature fluctuation will make the photovoltaic ribbon with a large thermal expansion coefficient and the crystalline silicon wafer. A large stress is generated between them. After cooling, under the action of the stress, the cells will be bowed, which may develop into cracks or directly cause fragments in the subsequent laying and lamination. The electrodes of the IBC battery are all concentrated on the back side. The use of conventional ribbon welding will lead to stress concentration and large warpage of the battery sheet. Moreover, the insulating paste of the IBC battery is not resistant to high temperature and cannot be welded with conventional ribbons.

At present, IBC batteries can be welded with conductive tape. The conductive tape can be welded at low temperature, and because of its own stretchability, it can buffer the stress of the welding tape and the IBC battery, reduce the warpage of the battery, and reduce the Cracks and chips, but this method is more expensive.

Therefore, a welding tape for IBC photovoltaic modules is particularly required to solve the above-mentioned existing problems.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a welding tape for IBC photovoltaic modules, which can buffer the stress after welding, reduce the fragmentation rate during the component preparation process, and solve the problem of the insulation paste of IBC cells. It is resistant to high temperature and cannot be welded with conventional welding tapes.

The technical problem solved by the present invention can be realized by the following technical solutions:

A welding tape for IBC photovoltaic modules, characterized in that it comprises a base material and a coating covering the surface of the base material, the base material is provided with stress buffer grooves, and the stress buffer grooves are distributed on the base material lengthwise and widthwise.

In an embodiment of the present invention, the thickness of the welding strip is 0.18-0.25 mm, and the width of the welding strip is 1-2 mm.

In one embodiment of the present invention, the substrate is oxygen-free copper.

In an embodiment of the present invention, there are 2-3 stress buffer grooves in the length direction of the substrate, and 1-2 stress buffer grooves in the width direction of the substrate.

In one embodiment of the present invention, the composition of the coating is Sn50-55wt%, Bi 10-15wt% and Pb35-40wt%.

In an embodiment of the present invention, the thickness of the coating is 20-40 μm, and the yield strength is less than or equal to 65 Mpa.

In an embodiment of the present invention, the coating is prepared by vacuum evaporation, and the three metals Sn, Bi, and Pb are respectively loaded into the three evaporation sources of the vacuum coating machine, and each evaporation is independently controlled. The evaporation rate of the source such that the various atoms reaching the substrate correspond to the composition of the desired coating.

Compared with the prior art, the welding tape used for the IBC photovoltaic module of the present invention adopts three materials of Sn, Bi and Pb for the coating, and has a melting point of 160-180° C. It can realize low-temperature welding and has good tensile force, which solves the problem of The insulating paste of the IBC battery is not resistant to high temperature; the substrate contains a stress buffer tank, coupled with low-temperature welding, which can effectively reduce the problem of stress concentration and easy cracking during welding of the IBC battery; vacuum evaporation method is used to coat the coating , the film forming speed is fast, the quality is high, and the thickness can be precisely controlled, so as to achieve the purpose of the present invention.

The features of the present invention can be clearly understood by referring to the drawings and the detailed description of the preferred embodiments below.

Description of drawings

FIG. 1 is a schematic structural diagram of a welding tape for an IBC photovoltaic module of the present invention;

FIG. 2 is a schematic top view of a welding tape for an IBC photovoltaic module of the present invention;

FIG. 3 is a schematic side view of the welding tape for the IBC photovoltaic module of the present invention.

Detailed ways

In order to make it easy to understand the technical means, creation features, achieved goals and effects of the present invention, the present invention will be further described below with reference to the specific figures.

According to FIG. 1 to FIG. 3 , the welding tape for IBC photovoltaic modules provided by the present invention includes a substrate 1 and a coating 2 covering the surface of the substrate 1. The substrate 1 is provided with a stress buffer groove 3, and the stress The buffer grooves 3 are distributed in the longitudinal direction and the width direction of the base material 1 .

The base material 1 is oxygen-free copper, the composition of the coating layer 2 is Sn 50-55wt%, Bi 10-15wt% and Pb35-40wt%, the melting point of the coating layer 2 is 160-180 ℃, low temperature welding can be carried out, stability, Fluidity and wettability are relatively good.

Preferably, when the composition of the coating 2 is Sn 53wt%, Bi 10wt% and Pb 37wt%, the welding temperature is 170°C, when the substrate 1 of the proportional coating 2 is welded, the peeling of the lamination is avoided, while reducing the The temperature during welding is reduced, thereby reducing the cracking and chipping rate of the component.

In this embodiment, there are 2-3 stress buffer grooves 3 in the longitudinal direction of the base material 1 , and 1-2 stress buffer grooves 3 in the width direction of the base material 1 .

Preferably, there are two stress buffer grooves 3 in the length direction of the base material 1, and two stress buffer grooves 3 in the width direction of the base material 1; during welding, when the base material 1 is heated, the stress on the base material 1 is buffered The groove 3 can provide a certain deformation space, which can avoid battery cracks caused by thermal expansion and cold contraction, and buffer the stress of the base material 1 during welding.

In this embodiment, the thickness of the welding strip is 0.18-0.25 mm, and the width of the welding strip is 1-2 mm.

In this embodiment, the thickness of the coating layer 2 is 20-40 μm, and the yield strength is less than or equal to 65 Mpa.

Preferably, the thickness of the coating 2 is 25 μm, the yield strength is less than or equal to 65Mpa, the tensile strength is greater than or equal to 150Mpa, the elongation is greater than or equal to 25%, the thickness of the welding strip is 0.2 mm, and the width of the welding strip is 1.5 mm,

In this embodiment, the coating layer 2 is prepared by vacuum evaporation, and the evaporation rate of each evaporation source is independently controlled by loading the three metals Sn, Bi, and Pb into the three evaporation sources of the vacuum coating machine. , so that the various atoms reaching the substrate correspond to the composition of the desired coating.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above-mentioned embodiments, and the descriptions in the above-mentioned embodiments and the description are only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have Various changes and improvements fall within the scope of the claimed invention, which is defined by the appended claims and their equivalents.

Claims (7)

1. The solder strip for the IBC photovoltaic module is characterized by comprising a base material and a coating covering the surface of the base material, wherein the base material is provided with stress buffer grooves, and the stress buffer grooves are distributed in the length direction and the width direction of the base material.

2. The solder ribbon for IBC photovoltaic modules according to claim 1, wherein the solder ribbon has a thickness of 0.18-0.25mm and a width of 1-2 mm.

3. The solder ribbon for an IBC photovoltaic module according to claim 1, wherein the substrate is oxygen free copper.

4. A solder ribbon for IBC photovoltaic module according to claim 1, wherein said stress buffering grooves are 2-3 in length direction of said substrate and 1-2 in width direction of said substrate.

5. A solder ribbon for IBC photovoltaic modules according to claim 1, wherein the composition of the coating is Sn50-55 wt%, Bi 10-15 wt% and Pb35-40 wt%.

6. The solder ribbon for IBC photovoltaic modules according to claim 1, wherein the coating has a thickness of 20-40 μm and a yield strength of 65Mpa or less.

7. The solder ribbon for IBC photovoltaic module according to claim 1, wherein said coating is prepared by vacuum evaporation by loading three metals of Sn, Bi and Pb into 3 evaporation sources of a vacuum coater, and independently controlling the evaporation rate of each evaporation source so that the atoms reaching the substrate correspond to the composition of the desired coating.

Images