A typical photovoltaic module consists of solar cells, backsheets, photovoltaic glass, junction boxes, frames, packaging materials, etc. The packaging film material is located between the optical glass and the solar cell, and can be bonded to the solar cell, copper-tin soldering tape, backplane and optical glass, etc., and is an important part of the optical module. Ethylene vinyl acetate (EVA) encapsulation films in photovoltaic cells are thermoset and adhesive films. High quality EVA film has special advantages in terms of adhesion, durability, and optical properties, so it is widely used in photovoltaic modules and various optical products.

The single-glass photovoltaic module whose backplane is plastic and front is glass, mainly uses EVA packaging film, because it is non-adhesive at room temperature, it can be melted and bonded and cross-linked and solidified under certain conditions, and it is completely transparent. The light transmittance plays the role of penetration.

Double-sided glass double-glass photovoltaic modules, POE (ethylene-octene polymer) film is a commonly used packaging material in the market. Compared with EVA film, POE film has better performances such as safety and aging resistance. However, this material is 30%-50% more expensive than EVA film.

The thickness of double-glass photovoltaic module glass is now reduced from 2.5mm to 2.0mm, and is expected to drop to 1.6mm in the future. Due to the glass thickness of double-glass photovoltaic modules decreases, EVA film can also seal the frame of double-glass modules. In the future, EVA film will be widely used in double-glass modules.

The EVA raw material VA (vinyl acetate) content in the production of photovoltaic packaging film is more than 28%, and it is mainly produced by the extrusion method at present. With the rapid development of China’s photovoltaic market, the EVA film market is also growing rapidly. Since 2013, EVA film has been monopolized by overseas companies, and now domestic companies account for more than 90% of the domestic film field, and more and more oversea manufactures are using Chinese-made encapsulating film PV production.