NOVELTY - Processing vertical plate freezer (VPF) back plate for solar battery involves a) taking functional polyethylene terephthalate (PET) and normal PET slice into extruder, heating at 270-285 degrees C, melting to form melt stream having melt flow rate, passing melt flow through groove body, where each flow from the lip in the cold extrusion casting, drum up fast cooling, the cooling time is 2-5 minutes, b) entering the cooled composite structure into stretcher to finish bidirectional stretching, and forming functional PET layer (1) and normal composite PET layer (2).    USE - For processing vertical plate freezer (VPF) back plate for solar battery (claimed).    ADVANTAGE - The casting process using the functional layer PET and normal PET layer composite together, overcomes problem of delamination when using existing PET adhesive layer, and prolongs service life. Meanwhile, the use of functional PET layer and conventional PET layer composite structure, improve the overall performance of the back plate. The fluorine-containing coating on the side in contact with the ethylene vinyl acetate (EVA) has a good resistance to UV aging ability. The functional PET used in the outer surface of the air provides ultraviolet (UV) and heat aging double performance. The back plate has strong anti-aging properties of the environment.    DETAILED DESCRIPTION - Processing vertical plate freezer (VPF) back plate for solar battery involves a) taking functional polyethylene terephthalate (PET) and normal PET slice into extruder, heating at 270-285 degrees C, melting to form melt stream having melt flow rate, passing melt flow through groove body, where each flow from the lip in the cold extrusion casting, drum up fast cooling, the cooling time is 2-5 minutes, b) entering the cooled composite structure into stretcher to finish bidirectional stretching, and forming functional PET layer (1) and normal PET composite layer (2). The functional pet (polyethylene terephthalate) layer and conventional PET (polyethylene terephthalate) layer forming compound layer in the conventional PET-side coating fluorine resin, and carrying out microwave curing.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of the vertical plate freezer (VPF) back plate for solar battery.    Functional polyethylene terephthalate (PET) layer (1)    Conventional polyethylene terephthalate layer (2)