Improved Stamper
The groove patterns on the HD DVD disc surface are created by the process of moulding melted polycarbonate resin on a metal plate stamper, however, compared with DVD-R, HD DVD-R needs a narrower track pitch due to its higher recording density (DVD 0.74μm, HD DVD 0.4μm). This requirement for a narrower track pitch can not be made with existing manufacturing processes; therefore Verbatim has introduced a new stamper technology which makes this possible.



 Cross section with AFM (Replica)
 Conventional Stamper
 Rounded groove shape due to narrower track pitch than DVD






 Cross section with AFM (Replica)
 Improved Stamper
 Steep groove shape achieved by employing a new stamper  making process



Manufacturing Process
The HD DVD-R disc is based upon the same disc structure as current DVD discs, i.e. back-to-back bonding of two 0.6mm thick substrates. This being the case, current DVD-R manufacturing facilities can be modified - using a new dye - for the efficient production of HD DVD-R discs.

The use of existing (modified) DVD-R production facilities means that there is no need to invest in further manufacturing equipment for the conversion of current DVD-R production lines to HD DVD-R ones.

The manufacturing process:
Stage 1 - Stamper, Injection Moulding
Stage 2 - Cooling
Stage 3 - Dye coating
Stage 4 - Spin coating
Stage 5 - Dry
Stage 6 - Sputtering
Stage 7 - UV Cure
Stage 8 - Glue dispense
Stage 9 - Finished disc


High Quality Dye

Signal performance and high recording sensitivity
Verbatim has achieved excellent signal performance and high recording sensitivity, using a blue laser. PRSNR and SbER are standard indicators for signal quality. The higher the PRSNR value is, the better the quality. The lower the SbER value is, the better the quality. The standard requires a value of over 15 in PRSNR and under 5E10-5 in SbER. Our new dye exceeds the requirements of the standard. It can cope with a laser power variation (margin) of over 20%. The optimal power of Verbatim HD DVD R discs is around 8mW, while that of the book specifications is a maximum 10mW. This means that the Verbatim discs have a higher power margin than the book specification standard discs, resulting in improved compatibility across a wide variety of hardware.