Color photoengraving techniques for producing conductor devices

Claim 1

A METHOD OF PRODUCING A PLURALITY OF MASKS HAVING CUT-OUT PORTIONS WHICH WILL BE IN REGISTER WHEN THE MASKS ARE SUPERPOSED WHICH COMPRISES: (A) CONSTRUCTING A MASTER DRAWING HAVING REGIONS IN DIFFERENT COLOURS EACH CORRESPONDING IN SHAPE TO A DIFFERENT ONE OF SAID CUT-OUT PORTIONS, SAID REGIONS BEING ON A BLACK BACKGROUND; (B) PHOTOGRAPHING SAID DRAWING ON COLOURED FILM, WHEREBY SAID REGIONS APEAR ON SAID FILM IN THEIR RESPECTIVE COLOURS WITH THE BACKGROUND OPAQUE; (C) PRODUCING A PLURALITY OF FURTHER PHOTOGRAPHS FROM SAID COLOURED FILM EACH CONTAINING OPAQUE REGIONS CORRESPONDING TO THE REGIONS OF A PARTICULAR COLOUR BUT NO OTHER REGION, THE BACKGROUND BEING TRANSPARENT, SAID FURTHER PHOTOGRAPHS BEING EXACTLY THE SAME SIZE AND CAPABLE OF EXACT REGISTRATION; (D) PROVIDING A PLURALITY OF THIN METAL SHEETS, ONE FOR EACH FURTHER PHOTOGRAPH; (E) COATING SAID SHEETS WITH A LIGHT-SENSITIVE MATERIAL WHOSE RESISTANCE TO A DEVELOPER IS INCREASED BY THE ACTION OF LIGHT; (F) EXPOSING SAID SHEETS, THUS COATED, TO LIGHT THROUGH RESPECTIVE ONES OF SAID FURTHER PHOTOGRAPHS, WHEREBY IN EACH CASE THE REGIONS CORRESPONDING TO THE OPAQUE REGIONS ON THE FURTHER PHOTOGRAPHS WILL BE UNAFFECTED, WHILE THE RESISTANCE TO THE DEVELOPER OF THE BACKGROUND IS INCREASED; (G) TREATING THE SHEETS WITH DEVELOPER TO REMOVE THE UNEXPOSED PARTS OF THE LIGHT SENSISTIVE LAYER; AND (H) ETCHING AWAY THE PORTIONS OF THE SHEETS FROM WHICH THE LIGHT SENSISTIVE LAYER HAS BEEN REMOVED, LEAVING HOLES THROUGH THE SHEETS CORRESPONDING IN SHAPE TO THE ORIGINAL RESPECTIVE COLOUR REGIONS ON SAID DRAWING.

Claim 2

A METHOD OF PRODUCING A PLURALITY OF MASKS HAVING CUT-OUT PORTIONS WHICH WILL BE IN REGISTER WHEN THE MASKS ARE SUPERPOSED WHICH COMPRISES: (A) CONSTRUCTING A MASTER DRAWING HAVING REGIONS IN DIFFERENT COLOURS EACH CORRESPONDING IN SHAPE TO A DIFFERENT ONE OF SAID CUT-OUT PORTIONS, SAID REGIONS BEING ON A BLACK BACKGROUND; (B) PHOTOGRAPHING SAID DRAWING ON COLOURED FILM, WHEREBY SAID REGIONS APEAR ON SAID FILM IN THEIR RESPECTIVE COLOURS WITH THE BACKGROUND OPAQUE; (C) PRODUCING A PLURALITY OF FURTHER PHOTOGRAPHS FROM SAID COLOURED FILM EACH CONTAINING OPAQUE REGIONS CORRESPONDING TO THE REGIONS OF A PARTICULAR COLOUR BUT NO OTHER REGION, THE BACKGROUND BEING TRANSPARENT, SAID FURTHER PHOTOGRAPHS BEING EXACTLY THE SAME SIZE AND CAPABLE OF EXACT REGISTRATION; (D) PROVIDING A PLURALITY OF THIN METAL SHEETS, ONE FOR EACH FURTHER PHOTOGRAPH; (E) COATING SAID SHEETS WITH A LIGHT-SENSITIVE MATERIAL WHOSE RESISTANCE TO A DEVELOPER IS INCREASED BY THE ACTION OF LIGHT; (F) EXPOSING SAID SHEETS, THUS COATED, TO LIGHT THROUGH RESPECTIVE ONES OF SAID FURTHER PHOTOGRAPHS, WHEREBY IN EACH CASE THE REGIONS CORRESPONDING TO THE OPAQUE REGIONS ON THE FURTHER PHOTOGRAPHS WILL BE UNAFFECTED, WHILE THE RESISTANCE TO THE DEVELOPER OF THE BACKGROUND IS INCREASED; (G) TREATING THE SHEETS WITH DEVELOPER TO REMOVE THE UNEXPOSED PARTS OF THE LIGHT SENSISTIVE LAYER; AND (H) ETCHING AWAY THE PORTIONS OF THE SHEETS FROM WHICH THE LIGHT SENSISTIVE LAYER HAS BEEN REMOVED, LEAVING HOLES THROUGH THE SHEETS CORRESPONDING IN SHAPE TO THE ORIGINAL RESPECTIVE COLOUR REGIONS ON SAID DRAWING.