CONTENT
 CD Basics

 CD Audio

 CD-ROM

 DVDBasics

 DVD-Video

 DVD-ROM

 DVD-Audio

 DVD-Recordable

 Replication

 DigitalVideo

 Glossary


 
Replication introduction title graphic

CD & DVD Replication 

CD & DVD discs are replicated using similar processes but DVDs require new equipment and tighter process control.

CD and DVD disc replication involves the following processes:

Premastering and/or authoring which creates the data which is to be contained on the replicas to be produced.
Glass Mastering which is needed to create stampers which are used to mould the individual discs.
Producing individual discs by moulding using stampers followed by metallising and lacquering (for CDs) or bonding (for DVDs)
Printing of disc labels on each disc. CD and DVD have different print specifications.
Packaging of discs in suitable cases, usually different for CD and DVD.
Quality assurance to ensure discs meet the necessary specifications.

The CD and  DVD physical formats are listed in the table below.

Format Capacity  Description
CD 0.7 GB Single layer, single side;
read from one side only
DVD-5 4.7 GB single layer, single side;
read from one side
DVD-10  9.4 GB  single layer, double side;
read from both sides
DVD-9  8.5 GB  dual layer, single side;
read from one side 

DVD vs CD Replication

DVD discs are more difficult to manufacture than CDs, requiring new, purpose designed equipment rather than upgraded equipment. DVD discs are different from CDs in the following ways:

  • Pit sizes half that of CD pits
  • Track pitch half that for CDs, with tighter tolerances
  • Higher mastering speeds, both in angular and linear velocity and data rate
  • New data formatting requirements, particularly for dual layer discs.
  • Two disc substrates to mould per final disc, each half the thickness of a CD

CD vs DVD disc cross-section

  • Tighter tolerances on tilt and jitter in particular
  • Additional bonding stage, which for dual layer discs must be optically transparent and of the correct thickness.
  • A range of disc formats including dual layer and double sided discs.

These differences require new or modified mastering equipment, moulding machines, metallisers and inspection equipment plus a new bonding stage, which present new challenges for equipment manufacturers and replicators. 

DVD replication has now reached a stage when over 1 billion discs have been replicated for commercial purposes.  As a result it has become a more mature format than a few years ago.  Cycle times are faster and yields are higher.  Replication capacity has also increased dramatically over the last few years.
 

In this page:

DVD vs CD Replication

See also:

Replication (PDF document)

 

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