| 摘要 |
PROBLEM TO BE SOLVED: To provide a protective film of a segment structure, in which a groove structure is prevented, especially by a structure leading from the side face of a groove to a bottom part of the groove and a structure of the bottom part of the groove, from being broken and damaged by the load deformation stresses of internal and external forces thereby to obtain a segment structure stable in strength.SOLUTION: A protective film has a segment structure, in which a film is stacked on a base material. After the base material is grooved, the protective film is stacked to form a spacing between the segment protective films. The longitudinal sections of portions, in which the groove side face and the bottom of the groove intersect, are jointed by a curve line bulging downward, and the longitudinal section of the bottom of the groove is a curve line bulging downward or a straight line.SELECTED DRAWING: Figure 1 |
