TECHNOLOGY FOCUS - ELECTRONICS - Preferred Process: An impurity diffused layer (2) is formed in the light receiving surface side of crystalline silicon substrate (1) containing single crystal silicon or polycrystalline silicon. An electrode (5) is formed in the impurity diffused layer surface at the side of the light receiving surface, and another electrode (6) is formed in the back surface side of the substrate. A back surface reflection layer is formed in the back surface side of the substrate. A solar cell is formed by connecting the electrode through the back surface side of the substrate and opening portion of polyimide ink.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Particles: The light reflective particles are white pigment particles chosen from silica, zirconia, alumina, tantalum oxide, titanium oxide, zinc oxide and vanadium oxide. The composition contains 1-80 parts weight of light reflective particles with respect to 100 parts weight of polyimide resin.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The composition contains 0-20 mol% of 1,3-bis(3-aminopropyl)tetramethyl disiloxane having glass transition temperature of 150 degrees C or more with respect to the total amount of diamine components. The solvents (A,B) have different evaporation rate. The solubility of the polyimide is low in the solvent with slow evaporation rate. The solvent (A) is hydrophobic solvent and the solvent (B) is hydrophilic solvent.    TECHNOLOGY FOCUS - POLYMERS - Preferred Resin: The polyimide resin is heat-resistant resin soluble in mixed solvent comprising organic solvent (A) and organic solvent (B). The polyimide resin has thixotropic property and contains 1-4C alkyl group and/or 1-4C perfluoroalkyl group in the repeating unit. The polyimide resin has repeating unit of formula (I).Ar1=tetravalent organic group, preferably group of formula (a);Ar2=divalent organic group, preferably group of formula: -(CH2)n-(Si(-R2)(-R1)-O)m-Si(-R3)(-R4)-(CH2)n or group of formula (b) or (c);T,W'=-C(CH3)2- or -C(CF3)2-;R1-R4=H, hydroxy, 1-4C alkyl, phenyl, F, Cl or Br, at least one being 1-4C alkyl;m,n=1-10;X,Y'=-C(=O)-, -SO2-, -O-, -S-, -(CH2)a-, -NHCO-, -C(CH3)2-, -C(CF3)2-, -C(=O)O- or single bond;a=1-5;R5-R7=H, hydroxy, 1-4C alkyl, phenyl, F, Cl or Br, at least one being 1-4C alkyl;andp1-p3=1-4.The polyimide membrane is formed by screen printing method, inkjet method or dispensing method. The thickness of the dry polyimide membrane is 1 mu m or more. Preferred Property: The composition has viscosity of 20000-200000 mPa.second at shear rate of 1-100/second, and thixotropy coefficient of 1.5-10.0.