Abstract: The present invention relates to a removable pressure-sensitive adhesive composition containing an acrylic polymer, a photopolymerization initiator and a crosslinking agent, in which the acrylic polymer and the photopolymerization initiator each are chemically bonded to the crosslinking agent. The present invention also relates to a removable pressure-sensitive adhesive composition containing an acrylic polymer and a photopolymerization initiator, the composition further containing a crosslinking agent having a reactive functional group which is capable of reacting with a reactive functional group of the acrylic polymer and a reactive functional group of the photopolymerization initiator.

Abstract: An adhesive sheet for processing semiconductor wafers and/or substrates comprises a UV- and/or radiation-transmittable base film and an adhesive layer that undergoes a polymerization curing reaction by means of UV rays and/or radiation, wherein the adhesive layer comprises at least a tackifier and a surfactant. The adhesive sheet of the present invention can be to lower the adhesive strength to the optimal level during pick up or the like after irradiation with UV rays and/or radiation, while maintaining adhesion with adherends before irradiation with UV rays and/or radiation by ensuring that, regardless of the texture on the surface of adherends such as semiconductor wafers and/or substrates, the adhering surface favorably conforms to the texture with preserving enough adhesive and cohesive strength.

Abstract: The present invention provides an adhesive sheet for water jet laser dicing, comprising an adhesive layer laminated on a base film which has a mean opening diameter of 5 ?m to 30 ?m. According to the adhesive sheet of the invention, a base film having a mean opening diameter of a certain size is used, thus ensuring better permeability to liquids originating in a liquid stream, and preventing the material that is being processed from being separated by the liquids from the adhesive sheet. In addition, the relatively low mean opening diameter makes it possible to control rippling on the surface of the base film and kept the surface flat, resulting in better adhesion to the material being processed and ensuring that the material being processed is secured during the dicing stage.

Abstract: An adhesive sheet for laser processing comprises an adhesive layer laminated on the surface of a base film, wherein the base film has a textured contact-reducing layer on the back side thereof. According to the adhesive sheet for laser processing of the present invention, the melting of the base film caused by the local concentration of laser beam energy at the places irradiated with the laser beam can be effectively prevented. Accordingly, the back side of the base film can be prevented from locally adhering to the processing table in the dicing apparatus, and subsequent steps, namely, drawing the base film to separate the workpiece from the adhesive layer, and individually recovering these, can be carried out easily and efficiently.

Abstract: The present invention relates to a method of semiconductor wafer back processing, which includes applying a radiation-curable pressure-sensitive adhesive sheet comprising a base film and a pressure-sensitive adhesive layer disposed on one side of the base film to a front side of a semiconductor wafer, the front side of the semiconductor wafer having recesses and protrusions; grinding the back side of the semiconductor wafer in such a state that the radiation-curable pressure-sensitive adhesive sheet is adherent to the front side of the semiconductor; and irradiating the pressure-sensitive adhesive sheet with a radiation to thereby cure the pressure-sensitive adhesive layer, followed by subjecting said ground back side of the semiconductor wafer to a surface treatment; and a radiation-curable pressure-sensitive adhesive sheet for use in the method of semiconductor wafer back processing.

Abstract: An adhesive sheet for water jet laser dicing, comprises an adhesive layer laminated on a base film, wherein the adhesive sheet has perforations, has a porosity of 3 to 90% and has a fracture elongation of at least 100%.

Abstract: An adhesive sheet for laser processing, comprises a base film and an adhesive layer laminated on the surface of the base film, wherein the base film has a melting protection layer on the back side thereof. According to the adhesive sheet for laser processing of the present invention, the melting of the base film caused by the local concentration of laser beam energy at the places irradiated with the laser beam can be effectively prevented. Accordingly, the back side of the base film can be prevented from locally adhering to the processing table in the dicing apparatus, and subsequent steps, namely, drawing the base film to separate the workpiece from the adhesive layer, and individually recovering these, can be carried out easily and efficiently.

Abstract: An adhesive sheet for water jet laser dicing, comprises an adhesive layer laminated on a base film, wherein the adhesive constituting the adhesive layer is an energy radiation curing type adhesive, and said adhesive sheet has an adhesive strength of at least 1.5 N/20 mm.

Abstract: The present invention relates to a pressure-sensitive adhesive sheet for semiconductor wafer processing, which includes a substrate and a pressure-sensitive adhesive layer disposed on the substrate, the pressure-sensitive adhesive sheet or said substrate having a thermal shrinkage ratio of 2% or lower after having been allowed to stand at 60° C. for 10 minutes. This pressure-sensitive adhesive sheet preferably has a degree of elongation of 2% or lower in a silicon wafer application test of the pressure-sensitive adhesive sheet. According to this pressure-sensitive adhesive sheet, the back side of a semiconductor wafer can be ground to an extremely small thickness without bending the wafer.

Abstract: The present invention relates to a pressure-sensitive adhesive sheet for processing a semiconductor wafer or semiconductor substrate, which includes a base material and a pressure-sensitive adhesive layer which is polymerizable and curable by an energy ray, the pressure-sensitive adhesive layer being disposed on a surface of the base material, in which the pressure-sensitive adhesive layer includes a base polymer, a multifunctional acrylate-based oligomer which has an energy-ray polymerizable carbon-carbon double bond and has a molecular weight of 1000 to 2500, and a multifunctional acrylate-based compound which has an energy-ray polymerizable carbon-carbon double bond and has a molecular weight of 200 to 700. The pressure-sensitive adhesive sheet of the invention is excellent in follow-up properties to a minute unevenness with a depth of about 0.

Abstract: The present invention relates to a pressure-sensitive adhesive tape or sheet for dicing which is to be applied to an active surface in the state of being not wholly covered with a native oxide film. The adhesive tape or sheet includes a substrate, and a radiation-curable pressure-sensitive adhesive layer disposed on at least one side of the substrate, in which the pressure-sensitive adhesive layer contains an acrylic polymer (A) having a weight-average molecular weight of 500,000 or higher and at least one radiation-polymerizable compound (B) selected from cyanurate compounds having one or more groups containing a carbon-carbon double bond and isocyanurate compounds having one or more groups containing a carbon-carbon double bond, and the ratio of the radiation-polymerizable compound (B) with respect to 100 parts by weight of the acrylic polymer (A) is 5 to 150 parts by weight.

Abstract: To provide a pressure-sensitive adhesive sheet for use in processing wafers and the like articles, that produces less cutting sludge of the pressure-sensitive adhesive sheet and that can follow up unevenness of a wafer even when a difference in height of the unevenness is large, the pressure-sensitive adhesive sheet includes a base having on one surface thereof an intermediate layer and a pressure-sensitive adhesive layer in order, wherein the intermediate layer has an initial elastic modulus of 0.5 N/mm2 or less, a loss tangent (tan?) at 20° C. to 70° C. of 0.

Abstract: According to the invention, a pressure-sensitive adhesive sheet for use in dicing of a workpiece is provided which comprises a base film and at least a pressure-sensitive adhesive layer provided on the base film, wherein the pressure-sensitive adhesive layer comprises an acrylic polymer that contains at least 5% by weight of a monomer unit having an alkoxyl group in its side chain. According to the structure, there are provided a pressure-sensitive adhesive sheet for dicing that can produce good pickup performance even after a long time and a method of picking up a product worked with the pressure-sensitive adhesive sheet.

Abstract: A wired circuit board having a terminal portion formed as a flying lead that can provide enhanced strength of the conductive pattern, both sides of which are exposed, by simple construction to effectively prevent disconnection of the conductive pattern. The wired circuit board having the terminal portion formed as the flying lead in which the both sides of the conductive pattern are exposed includes, in crossing areas where ends of a cover-side opening and ends of a base-side opening and the conductive pattern are crossed each other, (i) the widened portions formed in the conductive pattern or (ii) cover-side projections and base-side projections formed in the cover layer and the base layer, respectively.

Abstract: A nickel plating layer having a thickness within a range of 1.0 to 4.0 &mgr;m is formed in a terminal portion of a circuit board as an underlying plating layer. After a soldering bump is formed on the underlying plating layer, the soldering bump is connected to an external terminal formed in an external circuit.

Abstract: A wired circuit board having a terminal portion formed as a flying lead that can provide enhanced strength of the conductive pattern, both sides of which are exposed, by simple construction to effectively prevent disconnection of the conductive pattern. The wired circuit board having the terminal portion formed as the flying lead in which the both sides of the conductive pattern are exposed includes, in crossing areas where ends of a cover-side opening and ends of a base-side opening and the conductive pattern are crossed each other, (i) the widened portions formed in the conductive pattern or (ii) cover-side projections and base-side projections formed in the cover layer and the base layer, respectively.

Abstract: A nickel plating layer having a thickness within a range of 1.0 to 4.0 &mgr;m is formed in a terminal portion of a circuit board as an underlying plating layer. After a soldering bump is formed on the underlying plating layer, the soldering bump is connected to an external terminal formed in an external circuit.