TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The inorganic filler is chosen from titanium dioxide, silicon dioxide, zinc oxide, mica, wollastonite, talc, zinc sulfide, calcium carbonate, barium sulfate, tungsten carbide, silicon carbide, boron nitride, montmorillonite, clay, glass fiber, glass micro-beads and magnesium oxide.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The base film layer material contains polyamide or polyester, preferably chosen from 41 compounds e.g. polyamide 6, polyamide 66, polytrimethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate. The thin film layer (b) contains fluorine-containing polymer or polycarbonate. The fluorine-containing polymer is obtained from tetrafluoroethylene, ethylene, maleic anhydride, hexafluoropropylene, propylene, vinylidene fluoride, vinyl fluoride, vinylidene fluoride, vinylidene fluoride and chlorotrifluoroethylene. The thin film layer (b) contains polyolefin or olefin copolymer. The polyolefin comprises high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear-low-density polyethylene, ultra-high-molecular weight polyethylene, metallocene linear-low-density polyethylene, chlorosulfonated polyethylene, chlorinated polyethylene, polypropylene, ethylene-vinyl alcohol copolymer, ethylene-acrylic acid polymer, silane-grafted polyethylene, maleic anhydride-grafted polyethylene, polypropylene and maleic anhydride-grafted polypropylene. The olefin copolymer comprises ethylene, vinyl acetate, 1-4C alkyl acrylate, 14-C alkyl methacrylate, acrylic acid, methacrylic acid and maleic anhydride. The thickness of each thin film layer (b) and thin film layer (c) is 10-500 mu m, respectively. The base film layer and/or thin film layers (a) and (b) contain inorganic filler, antioxidant, ultraviolet stabilizer, anti-hydrolysis agent, flame retardant, plasticizer, pigment and silane coupling agent. The solar cell assembly back plate further has back adhesive layer containing polyethylene-ethylene copolymer, polypropylene, modified polypropylene, thermoplastic polyurethane, acrylic resin and acrylonitrile-butadiene-styrene resin