GB1441745A - Manufacture of a pattern on a substrate - Google Patents

Abstract

1441745 Removing material by lasers and ions EMI Ltd 25 Sept 1973 [6 Oct 1972] 46106/72 Heading B3V [Also in Division G2] A light filter pattern on a substrate is produced by coating a substrate 3 with a first layer 2 of filter material and an absorption layer 1 capable of absorbing electromagnetic energy, removing portions of the absorption layer 1 with a beam of electromagnetic radiation to expose parts of the first layer 2, Fig. 2, removing the exposed parts of the first layer 2 to expose the substrate 3 and removing the remaining parts of the absorption layer 1, Fig. 4. In the manufacture of a dichroic filter for a colour television, a glass substrate 3 is coated with an oxide layer 2 of dichroic filter material and a layer 1 of lead. After removing portions of the lead layer 1 with a laser beam, Fig. 2, the exposed filter layer 2 and part of the remaining lead layer 1 are removed by sputter etching (Fig. 3, not shown). The remaining lead layer 1 is removed by a laser to form a pattern of dots or parallel lines of dichroic material Fig. 4. A protective layer 4 of quartz may be applied to the filter and the process repeated using the quartz layer 4 as the substrate.