| 摘要 |
<p>Disclosed is an adhesive sheet comprising a base material and an adhesive layer formed on the base material, wherein the adhesive layer has a creep ratio of 2.5% or less, an elasticity change ratio of 73% or more and Martens hardness of 80 N/mm2 or less. When the adhesive sheet is compressed to convex parts in a material having concave parts and the convex parts repeatedly, the deformation occurring in the convex parts can be prevented and the reduction in light permeability caused by the deformation, i.e., whitening, can be prevented. Therefore, the adhesive sheet can be used suitably as a surface-protecting film for a photomask, which is used in the production of a printed wiring board or the like using a substrate having concave parts and the convex parts such as through holes formed thereon.</p> |
