Application cases of photovoltaic EVA hot melt adhesive film used for cell lamination

Photovoltaic EVA hot-melt adhesive film is a key material for solar cell module packaging. It plays a dual role of bonding and protection in the cell lamination process. Several typical application scenarios are described below.

It is most widely used in conventional crystalline silicon component packaging. During lamination, EVA adhesive films are placed on the upper and lower sides of the cell, with the upper layer covered with glass and the lower layer attached to the back panel. When the temperature of the laminator rises to about 145 to 155 degrees Celsius, the adhesive film melts from a solid state to a viscous flow state, fully infiltrating the surface of the cell and the welding ribbon area under vacuum conditions, filling all gaps, and then a curing reaction occurs under the action of the cross-linking agent to form a dense and strong bonding layer. A large-scale ground power station project uses modules with this packaging method. After long-term outdoor operation testing, the bond strength attenuation rate is less than 10%, and the annual module power attenuation is controlled within 0.5%, fully verifying its reliability.

The application in double-glass modules is also becoming increasingly mature. Bifacial power generation components use a two-layer glass structure, which requires higher light transmittance and weather resistance of the film. By optimizing the ratio of tackifier and anti-UV agent in the EVA formula, the film performed stably in the humid heat aging test, and the power loss was significantly reduced after the potential-induced attenuation test, meeting the thirty-year service life requirement of the double-sided module.

In heterojunction battery packaging, low-temperature curing EVA adhesive films have been widely used. The amorphous silicon passivation layer of heterojunction cells is temperature sensitive, and traditional high-temperature lamination processes can easily damage battery performance. The low-temperature fast-setting adhesive film can complete cross-linking at 120 to 135 degrees Celsius, which not only ensures the packaging quality, but also avoids high-temperature damage to the cells. The loss of module efficiency after lamination is controlled within 0.1%.

In addition, in the field of building-integrated photovoltaics, colored EVA film and cells are laminated together to achieve the unification of power generation function and architectural decoration effect, expanding the application boundaries of photovoltaic products.