Patent ID: 6500281
Filing Date: 2002-12-31
Classification: C22C,H01J

Abstract:
Material used for a shadow mask having through-holes for passing an electron beam formed by etching, with improved uniformity of diameter, and consisting of an Feâ€”Ni alloy, which consists of, by mass percentage (%), from 34 to 38% of Ni, not more than 0.5% of Mn, from 5 to 40 ppm of B, from 5 to 40 ppm of N, the balance being Fe and unavoidable and incidental impurities with the proviso of 0.10% or less of C, 0.30% or less of Si, 0.30% or less of Al, 0.005% or less of S, and 0.005% or less of P, characterized in that the precipitates and inclusions, observed by an anodic solution method essentially consist of 2000 or more of precipitates and inclusions from 0.01 &mgr;m to 5 &mgr;m in diameter are varied on the surface of said material per mm2 of said surface, with said anodic solution method comprising subjecting a sample to an anodic solution in an acid solution containing 20 g/L of hydrochloric acid at a potential of 250 mV relative to the standard hydrogen electrode.