Entry sheet for drilling and method for drilling processing using same

Abstract

Entry sheet for drilling including a metallic foil and a layer of a resin composition, the layer formed on the metallic foil without interposing an adhesion layer, in which the layer of the resin composition has a peak attributable to a carbon atom-oxygen atom double bond appearing at 1700 to 1750 cm−1 and a peak attributable to a carbon atom-oxygen atom single bond appearing at 1080 to 1300 cm−1 in infrared spectroscopy, and when the absorbance at the peak attributable to the carbon atom-oxygen atom double bond appearing at 1700 to 1750 cm−1 is represented by Abs(C═O)L, and the absorbance at the peak of the carbon atom-oxygen atom single bond appearing at 1080 to 1300 cm−1 is represented by Abs(C—O)L, the layer of the resin composition has an absorbance ratio (C) of 0.12 to 1.80, the absorbance ratio (C) represented by the following expression (1). Absorbance ratio(C)=Abs(C═O)L/Abs(C—O)L   Expression (1).

Dependencies are inferred from the claim text.