公开(公告)号：GB1055073A

公开(公告)日：1967-01-11

申请号：GB2479964

申请日：1964-06-15

Applicant: IBM

Inventor： HUSSEY HUGH HARRY DONALD ,  DAVIES MICHAEL BASIL ,  LENOBLE JEAN PAUL ,  RUSSELL ALAN DAVID

IPC: C23C18/16 ,  G03C5/40 ,  H05K3/10

Abstract: An electrically conductive surface is formed on a base of e.g ceramic, mica, wood, paper, glass or plastics, by partly exposing and developing a silver halide emulsion, removing the exposed part with a bleach-etch solution and then fully exposing and developing the remaining unexposed part. In an example for forming a printed circuit, a film is partly exposed through a negative mask, developed, rinsed, immersed in a bleach-etch solution comprising cupric sulphate, citric acid, potassium bromide, and hydrogen peroxide, reexposed, developed, rinsed, immersed in a similar bleach-etch solution, rinsed, fully exposed, developed, rinsed, and the printed wiring so formed is polished. The wiring may be built up by electroless deposition of copper using an alkaline solution of copper sulphate with formaldehyde. The conductive layer may be baked to remove residues of gelatine, and lacquered to make the surface non-hygroscopic.