PV ribbon may affect the future of the PV industry

The business difficulties of PV ribbon suppliers, coupled with the continued shortage of tin metal, may at some point cause a crisis in the PV ribbon supply chain and warrant the vigilance of PV module companies.

According to the link of the photovoltaic industry chain, the photovoltaic industry chain mainly includes the upstream: silicon material, cell equipment manufacturers. Midstream: Mono/polycrystalline cell and module manufacturers. Downstream: inverter, power station. Photovoltaic ribbons made of tin-lead solder and copper substrates are mainly used in mid-stream photovoltaic modules. Photovoltaic ribbons are mainly divided into two types: Tabbing wires and busbar ribbons.

The photovoltaic ribbon is a uniform layer of tin-based solder material coated on the surface of copper tape. Photovoltaic ribbons are mainly processed from copper base material, tin alloy coating, and flux, and the raw material cost accounts for more than 90%. According to the application, we can divide it into interconnection tape (connecting the cell, soldering on the grid line with the cell) and convergence tape (connecting the cell string and junction box).

From the perspective of the cost structure of PV modules, the proportion of welding tape to the cost of the module is only 2.7%. However, the quality of solder tape products directly affects the collection efficiency of PV module current and has a large impact on the power generated by PV modules.

1. SMBB will become the mainstream, putting higher requirements on the accuracy of the welding tape process

1) Various main gate technology market share forecast

The development of photovoltaic solder tape follows the iteration of photovoltaic cell technology. From the initial 2BB-5BB to the current MBB, solder tapes have evolved from the initial calendered flat tin-coated tapes to the current round and shaped tapes. At present, the mainstream photovoltaic tape products in the market are MBB tapes which are suitable for multi-grid modules. It is finer and denser than conventional tapes. And it helps to reduce the shading of the cells and reduce the power loss of the cells.

• MBB round wire welding tape

With the development of battery technology, the grid line becomes smaller and smaller

Conventional round wire ribbon will develop into a thin wire

The low-temperature tape will be a thin wire

• MBB profiled welding tape

Continued advancement toward the reflective converging tape

Ultra-thin husbands

• Black welding tape

166/182/210 Late Xunjunhui involved in segmented welding tape

Shaped welding tape towards thin wire and shape diversification

Circulation accuracy and tin layer size accuracy requirements are higher

• Converging tape

Interconnection black solder tape and convergence black continue to develop

The emergence of diversified black solder tape

2) Photovoltaic welding tape future technology development trend

With the development of the new TOPCon and HJT cell technology, the welding grid line will further become thinner and thinner, and the diameter ≤ 0.25mm SMBB ultra-fine round welding tape will become the mainstream demand in the future. Photovoltaic welding tape will be towards the development of fine lines mainly. And it shaped welding tape as a supplement to the technical route. The ultra-fine line of welding tape, inevitably on the welding tape production enterprises process accuracy, yield, R & D capabilities, financial strength, management capabilities, and other aspects of higher requirements, thereby further improving the manufacturing threshold and production capacity concentration of welding tape.

In addition, the large-scale application of flexible segmented welding tape has given rise to the birth of small-pitch cell layout techniques such as patchwork and stacked welding. On the basis of traditional module technology, this micro-innovation was developed. And nevertheless achieves a similar energy density to that of stacked tile modules.

2. Photovoltaic solder tape is difficult to be replaced

Stacked tile modules partially replace photovoltaic welding tape with conductive adhesive. Stacked tile modules have obvious advantages over conventional modules in terms of power density, as well as resistance to hot spots, and many other advantages. Compared to photovoltaic tape, the cost of conductive adhesive is much higher. Related technology and patents in the hands of a few foreign companies, and to ensure the stability of the bonding of conductive adhesive in large-scale mass production also have a high technical threshold.

In addition, the large-scale application of flexible segmented welding tape has given rise to the birth of small-pitch cell layout techniques such as patchwork and stacked welding. And we developed this micro-innovation on the basis of traditional module technology. And nevertheless achieves a similar energy density to that of stacked tile modules.

Therefore, most module manufacturers have also reduced the incentive to shift to the stacked tile technology route. For all these reasons, stacked tile modules are not currently used on a large scale in the PV industry. And it is difficult to shake the dominant position of PV welding tape in the short and medium term.

3. The supply shortage of tin is the hidden worry

According to photovoltaic solder tape practitioners, the current mainstream solder tape coated tin alloy composition is generally 60% Sn, and 40% Pb. It means that more than 60% of the tin metal content. From the current mining, consumption of non-ferrous metals, tin in the 10 non-ferrous metals and is the most scarce species. The above-mentioned business difficulties of PV solder tape suppliers, coupled with the shortage of tin metal. It may cause a crisis in the PV solder tape supply chain at some point in time. And is worthwhile for PV module companies to be alert.