A brief analysis of the basic composition and glue requirements of solar photovoltaic modules

A set of solar photovoltaic modules is roughly composed of tempered glass, EVA film, battery sheet, backplane, aluminum alloy frame, junction box, and component glue.

Solar photovoltaic modules are mainly used outdoors, so the sealant selected must adapt to the climate differences of different regions when used outdoors for a long time, such as high temperature, high humidity, high and low temperature, strong ultraviolet rays, ozone, wind and rain and other natural conditions.

Silicone sealants are currently used in solar energy because of their excellent high and low temperature resistance, excellent adhesion, excellent aging resistance, excellent insulation properties, good elasticity, hydrophobicity, simple application process and high production efficiency. It is widely used in photovoltaic module packaging production.

1. Glue requirements for bonding and sealing of frames, backplanes and junction boxes

Solar cells are the core components of solar photovoltaic power generation systems. Due to the defects of thin, brittle and easy oxidation of solar cells, they need to be protected and packaged to form solar cell modules with stable performance. Therefore, the performance requirements of bonding and sealing adhesives are as follows:

(1) The curing speed is fast and the production operation process is simple;

(2) It has good adhesion to various backplanes, frames and junction boxes;

(3) Small thermal stress, good heat dissipation, good weather resistance, good UV resistance, good waterproof performance, and good electrical insulation;

(4) Maintain the physical and electrical characteristics of the sealed assembly under a wide range of temperature (-40 ℃~ 150 ℃), humidity and harsh environmental conditions;

(5) The stress generated by shock and vibration is absorbed, and the waterproof seal keeps the battery dry and not damaged by stress, resistant to yellowing, repairable, and has a lifespan of more than 20 years.

2. Glue requirements for junction box potting

The solar photovoltaic junction box is a connector between the solar cell square array composed of solar cell modules and the solar charging control device. It is an indispensable supporting component for solar power generation equipment. The performance requirements of the potting glue are as follows:

(1) Simple operation, good self-leveling and self-foaming performance, fast curing;

(2) After curing, it has good waterproof, insulation and thermal conductivity, and has good bonding;

(3) Excellent anti-aging performance, outdoor use can resist the adverse effects of ultraviolet light, ozone, moisture, acid and alkali, and maintain physical properties and electrical insulation properties.

Combined with the application, the main things that need to be investigated for the bonding and sealing glue for frames, backplanes, and junction boxes are its curing speed, as well as its adhesion, mechanical properties and electrical properties after hot and humid aging; The application period and the adhesion, heat dissipation and electrical properties before and after hot and humid aging.