| 摘要 |
PROBLEM TO BE SOLVED: To provide an adhesive, to provide an adhesive sheet using the adhesive, to provide a multilayered adhesive sheet using the adhesive sheet, and to provide a method for producing electronic elements by using the multilayered adhesive sheet. SOLUTION: A urethane-based polymer having polyol unit and polyisocyanate unit, an adhesive containing a multifunctional isocyanate curing agent, an adhesive sheet using the adhesive, a multilayered adhesive sheet using the adhesive sheet and a method for producing electronic elements by using the multilayered adhesive sheet are provided. The multilayered adhesive sheet is excellent in chip-retainability in dicing, hardly causes falling off from a ring frame in dicing and is easy in releasing the chip in pickup work. The multilayered adhesive sheet is suitable for the method for producing electronic elements, which method comprises, after dicing, picking up in a state adhering a die attach film layer on the rear side of a chip, mounting on a lead frame or the like, and curing and adhering by heating or the like. COPYRIGHT: (C)2007,JPO&INPIT
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