US Patent 7968039 Method of producing pressure-sensitive adhesive sheet

To produce a pressure-sensitive adhesive sheet according to which air entrapment and blistering can be prevented or eliminated through through-holes, and yet the through-holes are not readily visible at a substrate surface, a pressure-sensitive adhesive surface of a pressure-sensitive adhesive layer 12 in a laminate comprising a substrate 11 and the pressure-sensitive adhesive layer 12 is irradiated with a CO2 laser having a pulse width of from 1 to 140 μsec, a pulse energy at each processing point of from 0.01 to 3.0 mJ, and a beam spot diameter at each processing point of from 30 to 160 μm, so as to form through-holes 2 having a diameter at the surface of the substrate 11 of from 0.1 to 42 μm at a hole density of from 30 to 50,000 per 100 cm2.