The back panel needs to have good aging resistance and be able to maintain its performance during long-term outdoor use. Aging resistance includes resistance to UV rays, moisture and heat, high and low temperature, etc. Polymer materials can be improved through special treatment and formula design to improve their aging resistance. For example, adding additives such as UV absorbers and antioxidants can effectively resist the effects of UV rays and oxidation; using special coating technology can improve the moisture and heat resistance of the back panel.