Mass production method for fabricating multi-layer CDs

A method for mass-producing optical disk copies of two or more independent masters or stampers to increase data storage density, comprising the steps of:

• molding a substrate and first image layer by injecting hot molten plastic under pressure to press in intimate contact with a first stamper having a physical relief pattern in plan which represents digital information;
• cooling and separating said substrate and first image layer from said first stamper;
• depositing a partially reflective layer on said substrate and first image layer;
• pouring a liquid monomer having a first viscosity onto a second stamper having a physical relief pattern in plan which represents digital information independent of said first stamper and spinning said second stamper for a first time and a first speed;
• curing said liquid monomer to harden it into a polymer film representing a second image layer;
• adhering said polymer film to said partially reflective layer and said substrate and first image layer;
• separating said second stamper from said polymer film;
• and
• depositing a reflective film on said separated polymer film.

A method for mass-producing optical disk copies of two or more independent masters or stampers to increase data storage density, comprising the steps of:

• molding a substrate and first image layer by a photo-polymerization process in which an unheated liquid first monomer plastic is injected under pressure to press in intimate contact with a first stamper having a physical relief pattern in plan which represents digital information;
• curing said monomer with ultraviolet light to harden it into a polymer and separating said hardened-polymer substrate and first image layer from said first stamper;
• depositing a partially reflective layer on said substrate and first image layer;
• pouring a liquid second monomer plastic having a first viscosity onto a second stamper having a physical relief pattern in plan which represents digital information independent of said first stamper and spinning said second stamper for a first time and a first speed;
• curing said liquid monomer to harden it into a polymer film representing a second image layer;
• adhering said polymer film to said partially reflective layer and said substrate and first image layer;
• separating said second stamper from said polymer film;
• and
• depositing a reflective film on said separated polymer film.