Process for making multiple data storage disk stampers from one master

#The present invention relates generally to the field of manufacture of data storage disks, and in particular, to a method of making multiple optical data storage disk stampers from one master, while maintaining the integrity of data tracks encoded therein.

#Optical data storage disks have gained widespread acceptance for the storage, distribution and retrieval of large volumes of information. These disks include audio and video program material, as well as computer programs and data. Formats of optical data disks include audio CD (compact disc), CD-R (CD-recordable), CD-ROM (CD-read only memory), DVD (digital versatile disk or digital video disk) media, DVD-RAM (random access memory), and various types of rewritable media, such as magneto-optical (MO) disks and phase change optical disks.

#In general, optical disks (such as CD-ROMs) are produced by making (e.g., laser recording) a master which has physical features representing the data formed in or on a reference surface therein. The master is used to make a stamper, which, in turn, is used in an injection molding process to make production quantities of replica disks, each containing the data and tracking information which was encoded in the master.

#Other options of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof, and wherein:

#FIG. 1 is a block diagram illustrating one exemplary embodiment of a process for making multiple optical disk stampers from one master in accordance with the present invention;

#FIG. 2 is a diagram illustrating information layer orientation for an optical disk molded from a first generation, second generation or third generation stamper in accordance with the present invention;

#The present invention provides a process for making multiple stampers from one master. The process techniques described herein can be used for making a first, second, or third generation stamper. The process includes a step which is a photopolymerization step which is non-destructive to either the recorded master, first generation stamper or second generation stamper. This allows many next generation stampers to be made, while maintaining the integrity of the information layer transferred from the previous generation disk. In one preferred embodiment, a portion of a first stamper, which defines the information layer is transferred to and becomes part of a second stamper without changing the integrity of the information layer.

#In FIG. 1, a block diagram illustrating a process for making multiple stampers from one master in accordance with the present invention 30 is shown. In the exemplary embodiment shown, the process for making a stamper 30 provides for making a second generation stamper for use in a process for molding optical data storage disk substrates.

#The process 30 begins with providing a recorded master disk 32. A first generation stamper is made from the recorded master using a photopolymerization process, indicated at 34, which is nondestructive to the recorded master allowing for many first generation stampers to be made from a single recorded master. A second generation stamper is made from the first generation stamper, indicated at 36.