DICING-SHEET BASE FILM, DICING SHEET CONTAINING SAID BASE FILM, AND METHOD FOR MANUFACTURING SAID BASE FILM

摘要

A base film of a dicing sheet is provided which is less likely to generate cutting fragments in the dicing step and excellent in the expandability and recoverability. The base film (2) of a dicing sheet includes a cutting-fragment suppression layer (A) and an expandable layer (B) laminated on one main surface of the cutting-fragment suppression layer (A) . The expandable layer (B) has a laminate structure of a plurality of resin-based sublayers. The plurality of resin-based sublayers comprises a resin-based sublayer (B1) that is disposed nearest to the cutting-fragment suppression layer (A) and a resin-based sublayer (B2) that is at least one of other resin-based sublayers than the resin-based sublayer (B1). The resin-based sublayer (B1) comprises a linear polyethylene as a primary resin. The resin-based sublayer (B2) comprises an ethylene- (meth) acrylic acid series copolymer as a primary resin. The cutting-fragment suppression layer (A) comprises a ring-containing resin (a1) that is a thermoplastic resin having at least one type of an aromatic series-based ring and an aliphatic series-based ring and an acyclic olefin-based resin (a2) that is an olefin-based thermoplastic resin other than the ring-containing resin (a1).