| 摘要 |
PROBLEM TO BE SOLVED: To prevent solder residue or solder ball by forming the pattern of backside electrode as a thin wire, immersing a cell in a solder dipping tank such that it may be almost vertical to the level of a solder liquid, and pulling up it in the same manner. SOLUTION: The pattern of a backside silver electrode with approximately square cell of 5 inches is formed to be a unit pattern which is provided with three thin grids 16 together with one main grid 17, and a bridge electrode 18 is arranged vertically to the thin wiry electrode with a specified clearance. In addition, the wire width of the main grid 17 is about +0.5-2.0 mm larger than that of the grid 16. In solder dipping step, a cell is immersed and pulled up in/from the dipping tank in a manner that the main grid 17 and the grid 16 are parallel to each other. Thus, a cell in which no solder residue is generated on the surface and backside electrodes and which is excellent in reliability enough to have a predetermined electrode tensile strength can be obtained. |
