| 摘要 |
<p>1365426 Electroless plating RCA CORPORATION 2 Feb 1972 [8 Feb 1971] 4960/72 Heading C7F [Also in Division G2] Photo-masks comprise a glass substrate bearing a pattern of a nickel-phosphorus at least 1500A thick which has been formed on the substrate by (1) sensitizing the glass surface with an electroless deposition bath sensitizing solution (2) treating the sensitized surface with an activating solution to deposit nuclei of a metal which are catalytic to the deposition of nickel from an electroless autocatalytic bath, (3) contacting the activated areas with an electroless nickel bath comprising Ni sulphamate and hypophosphite ions to deposit a nickel-phosphorus coating and (4) baking to harden the coating. The pattern may be produced by (a) forming a continuous Ni-P layer, coating with photo-resist, exposing, developing, etching the bared Ni-P layer (e.g. with conc. HNO 3 ) baking at 100-250‹C, removing remaining photo-resist (e.g. with isopropanol or acetone), and rebaking, preferably at 380‹ C; or (b) forming a photo-resist pattern on the glass surface and then either treating the surface with a catalyst poison to prevent Ni deposition in the treated areas, or coating Ni directly over the photo-resist pattern and glass surface and removing the photo-resist and any over-lying Ni. Preferably the glass is cleaned with detergent and optionally chromic acid, sensitized with aqueous SnCl 2 /HCl, activated with aqueous palladium chloride/HCl, and plated with an aqueous solution prepared from NiCO 3 (31 g/l.<SP>-1</SP>), sulphamic acid (51g.) and NaH 2 FO 2 H 2 O (25g.) at pH 4-5 and 50-70‹ C to give a 1500-4000Š layer containing 11 wt per cent P. Reference is also made to plating in 2 stages, the sensitizing and actuating steps being repeated before the second plating and to adding an alloying metal e.g. tungsten or molybdenum to the plating bath.</p> |
