TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The copper ink further comprises surfactant and solvent. Preferred Components: The mass ratio of copper powder, soldering flux, glass material and bonding agent is 1:(0.2-0.05):(0.1-0.02):(0.05-0.008). The copper powder is pure copper or silver-plated copper powder. The grain diameter of copper powder is 0.2-20 mu m. The soldering flux includes tin, lead, bismuth, zinc, gallium or indium. The grain diameter of soldering flux is 0.2-30 mu m. The glass material includes at least two of silica, calcium oxide, bismuth oxide, zinc oxide, barium oxide and aluminum oxide. The grain diameter of the glass material is 0.2-10 mu m. The mass ratio of copper powder, surfactant, soldering flux, glass material, bonding agent and solvent is 1:(0.05-0.002):(0.2-0.05):(0.1-0.02):(0.05-0.008): (2-0.1).    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The solar energy cell includes crystalline silicon solar cell, thin film solar battery and/or composite solar battery. Preferred Method: The drying temperature is 70-120 degrees C, and the sintering temperature is 350-800 degrees C.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The bonding agent includes carboxymethyl cellulose, ethyl cellulose, butyl cellulose, polytetrafluoroethylene, polyvinylidene fluorine ethylene or styrene-butadiene rubber. The surfactant includes sodium dodecyl phenol polyoxyethylene ether, polyoxyethylene octylphenyl ether (non-ionic), nonyl phenol polyethenoxy ether, dodecyl dimethyl amine oxide, tetradecyl dimethyl amine oxide, fatty alcohol polyoxyethylene ether, polyoxyethylene octylphenol, cetylpyridinium chloride, isooctyl phenol polyoxyethylene ether, cetylpyridinium bromide, alkyl dimethyl betaine, hexadecyl trimethylamine, cocamidopropyl betaine, cetyltributylammonium chloride, polyethylene glycol mono stearate or hexadecyl trimethyl ammonium bromide. The solvent includes nitrogen methyl pyrrolidone, dimethyl sulfone, terpineol or diethylene glycol butyl ether.