NOVELTY - The method comprises providing (202) a solar cell having a front side and a back side, heating (204) a thermoplastic polyimide (300-375 degrees C) to a reflow temperature, electrically connecting a harness to the back side of the solar cell, flowing (206) the thermoplastic polyimide onto the back side of the solar cell while heated to the reflow temperature, and cooling (208) the thermoplastic polyimide to a temperature below the reflow temperature to bond the thermoplastic polyimide directly to the solar cell.    USE - The method is useful for constructing a solar cell panel.    ADVANTAGE - The method is capable of economically constructing the solar cell panel with long life span and less energy consumption.    DETAILED DESCRIPTION - The method comprises providing (202) a solar cell having a front side and a back side, heating (204) a thermoplastic polyimide (300-375 degrees C) to a reflow temperature, electrically connecting a harness to the back side of the solar cell, flowing (206) the thermoplastic polyimide onto the back side of the solar cell while heated to the reflow temperature, cooling (208) the thermoplastic polyimide to a temperature below the reflow temperature to bond the thermoplastic polyimide directly to the solar cell, bonding (210) a composite material substrate comprising graphite, aramid-based material and/or carbon fibers directly to the thermoplastic polyimide, without an adhesive, opposite the back side of the solar cell, providing the thermoplastic polyimide as a polyimide sheet, placing the polyimide sheet on the solar cell before heating, flowing and cooling the thermoplastic polyimide, and placing the substrate on the thermoplastic polyimide before to cooling the thermoplastic polyimide. The front side of the solar cell faces the sun during normal operation. The thermoplastic polyimide has a coefficient of thermal expansion that matches a coefficient of thermal expansion of the solar cell. The coefficient of thermal expansion of the solar cell is 3-8 ppm/ degrees C. The reflow temperature is 300-400 degrees C. The step of cooling of the thermoplastic polyimide includes cooling to an ambient temperature. The step of bonding the substrate to the thermoplastic polyimide includes applying heat and pressure to the composite after the cooling step. The substrate comprises a honeycomb composite that includes a graphite face sheet or an aramid-based face sheet. The back side of the solar cell includes a metal or ceramic. The harness is connectable to another solar cell, or solar cell panel. An INDEPENDENT CLAIM is included for a method of constructing a modular solar cell array.    DESCRIPTION OF DRAWING(S) - The diagram shows a flow chart of a method for constructing a solar cell panel.    Providing a solar cell having a front side and a back side (202)    Heating a thermoplastic polyimide to a reflow temperature (204)    Flowing the thermoplastic polyimide onto the back side of the solar cell (206)    Cooling the thermoplastic polyimide to a temperature below the reflow temperature (208)    Bonding a composite material substrate to the thermoplastic polyimide. (210)