PRESSURE SENSITIVE ADHESIVE AND A PRESSURE SENSITIVE ADHESIVE FILM HAVING THEREON A LAYER OF THE SAME

摘要

A pressure sensitive adhesive film reducible in the adhesive force by the application thereto of the ultraviolet light which comprises: (a) a base film permeable to the ultraviolet light; and (b) a layer of a pressure sensitive adhesive formed on one side of the base film, the adhesive comprising: (i) at least one elastic polymer selected from the group consisting of a polymer mainly composed of acrylic acid ester copolymers and a saturated copolyester mainly composed of dibasic carboxylic acids and dihydroxy alcohols; (ii) an ultraviolet light polymerizable acrylic acid ester having not less than two acryloyl or methacryloyl groups in the molecule and having a molecular weight of not more than about 1000, in amounts of about 15-200 parts by weight in relation to 100 parts by weight of the elastic polymer; and (iii) a photopolymerization initiator in amounts sufficent to induce the photopolymerization of the ultraviolet light polymerizable acrylic acid ester; The film is especially suitable for use as a dicing film in dicing a semiconductor wafer to dices in which the wafer is fixed on the film with a relatively large adhesive force and thereafter the film is irradiated by the ultraviolet light from the other side thereof to substantially reduce the adhesive force of the film so that the dice is loosely adhered onto the film.