Seamless Encapsulation For Higher Efficiency

• LONGi Solar says it has completely eliminated gap between cells with seamless soldering technology
• It achieved the feat using solder ribbon for tiled interconnection of the cell for this soldering that completely closes the typical 2mm wide cell gap
• LONGi said it plans to start mass production of the technology beginning H2/2019
• Seamless soldering technology is compatible with existing module encapsulation processes and equipment and can be easily scaled up, said LONGi

LONGi Solar announced plans to start mass production of a technology it terms as 'seamless soldering' that completely eliminates the gap between cells and increases the efficiency of PV modules. The technology, when combined with innovative module design, has the potential to increase LONGi Solar's high efficiency PERC module power record to 500 W, according to a test by Germany's TÜV SÜD, said LONGi.

LONGi says it uses a solder ribbon to achieve 'tiled' interconnection of the cell for seamless soldering which completely closes the typical 2 mm wide cell gap. Along with increasing efficiency of the module, it reduces the bill of material (BOM) cost of the module, the company said.

It adds that the technology has good technical compatibility to integrate with M6 monocrystalline silicon wafers, thin silicon wafers, soldering wire and reflective ribbon. LONGi also said the technology is 'perfectly compatible' with existing module encapsulation processes and equipment, adding that it has high mass production maturity and stability. The capacity can also be easily scaled up.

The tech giant said it has carried out intellectual property research on this technology and has also applied for a number of related patents. LONGi's tiled interconnection is also called "shingle" technology, which was originally developed by two American companies – SunPower and Solaria. An overview on shingle panels and other module innovations is available in TaiyangNews' Advanced Solar Module Technology Report.

While all larger module manufacturers have displayed shingle modules at recent trade fairs, most were not selling commercial products as they tried to avoid patent issues. However, as TaiyangNews was told by one leading Chinese company that is also moving into shingles there are ways to enter shingle module production without infringing any patents.

Patent infringement is currently a hot topic in the field of PERC technology. LONGi Solar along with JinkoSolar and REC Group are embroiled in a legal tangle with a patent infringement case regarding passivation technology filed against the 3 by Hanwha Group. The United States International Trade Commission (USITC) has accepted the lawsuit (see USITC To Investigate Hanwha's Claims).