Solar panels need to be used outdoors for a long time, so the backplane needs to have good waterproof performance to prevent water vapor from penetrating into the solar cell and affecting its performance and life. Polymer materials such as TPT and PET have low water vapor permeability and can effectively prevent water vapor penetration. At the same time, the edge of the backplane is usually sealed with sealant to further improve the waterproof performance of the solar panel.