NOVELTY - A solar backplane comprises inner surface layer, core layer, and outer surface layer. The inner surface layer comprises polyamide resin; filler comprising polyethylene resin or ethylene-vinyl acetate copolymer; and additive comprising antioxidants, UV absorbers, and/or light stabilizers. The outer surface layer comprises polyamide resin; filler; and additive comprising antioxidants, UV absorbers, and/or light stabilizers. The core layer comprises modified polyethylene resin composition comprising polyethylene resin, graft polyethylene, filler, and additives.    USE - Solar backplane used for solar cell modules.    ADVANTAGE - The backplane has low water absorption and water vapor transmission, interlayer peeling strength superior to other backplanes, excellent electrical insulating properties, shrinkage rate, and hot air aging resistance.    DETAILED DESCRIPTION - A solar backplane comprises inner surface layer, core layer, and outer surface layer at a mass ratio of 10-20:20-40:40-60. The inner surface layer comprises polyamide resin; filler comprising polyethylene resin or ethylene-vinyl acetate copolymer; and additive comprising antioxidants, UV absorbers, and/or light stabilizers. The outer surface layer comprises polyamide resin; filler; and additive comprising antioxidants, UV absorbers, and/or light stabilizers. The core layer comprises modified polyethylene resin composition comprising 100 pts. wt. polyethylene resin comprising mixture of homo polyethylene resin and/or polyethylene copolymer resin, and has differential scanning calorimetry (DSC) melting point of 120-135 degrees C and melt flow rate of 1-2 g/10 minutes; 5-50 pts. wt. graft polyethylene; 0-100 pts. wt. filler; and 0-2.5 pts. wt. additives comprising antioxidants, UV absorbers, and/or light stabilizers. The graft polyethylene comprises 100 pts. wt. polyethylene resin comprising mixture of homo polyethylene resin and/or polyethylene copolymer resin, and has DSC melting point of 120-135 degrees C and melt flow rate of 1- 2 g/10 minutes; 0.5-2 pts. wt. grafting agent; and 0.03-0.2 pts. wt. initiator. An INDEPENDENT CLAIM is included for preparation of solar backplane by mixing polyethylene resin, grafting agent, and initiator, and melt extruding to obtain graft polyethylene; mixing with polyethylene resins, fillers and additives, and melt extruding to obtain modified polyethylene resin composition; and adding internal surface, core layer, and surface layer materials into first, second, and third extruders, simultaneously melt-extruding, casting, cooling, drawing out, and coiling.