CD MANUFACTURING
CYCLE
REPLICATED CD
PREMASTERING is
the first step in the CD manufacturing process. It all begins
with a customer providing the manufacturer with a digital format
tape containing information (ie: music) stored in binary form.
CRC (Cyclic Redundancy
Check): a mathematical process designed to detect
possible errors occurring during digital data transfer.
P&Q Encoding:
marking the beginning and the end of each track while calculating
its duration.
MASTERING is
the process of transferring digital information from a tape to
a polymer film. The mastering process entails several distinct
operations.
GLASS COATING:
the process of applying a photosensitive or thermosensitive polymer
layer (depending on the mastering system) onto a clean, polished
glass-like surface.
DECODING: deciphering
of information on the P&Q encoded tape. Decoding is done
in conjunction with the writing process.
WRITING: transferring
of digital information from the master tape to the polymer-coated,
glass disc (Glass Master). This process eventually creates Data
Pits.
FILM DEVELOPMENT:
the process of developing the film (polymer layer) and forming
the Data Pits -physical indentations which contain digital information.
When scanned by a D/A (Digital to Analog) converter, Data Pits
produce analog signals (ie: music).
DIRECT WRITING:
an option to Writing and Film Development, this one-step process
utilizes laser technology. Direct Writing permits transferring
of digital information from the master tape to the polymer-coated,
glass disc while simultaneously forming and finishing the Data
Pits.
GLASS MASTER METALLIZATION:
as a preparation for electroplating, a conductive layer is applied
over the developed polymer film.
REPLICATION:
is the actual process of CD manufacturing from electroplating
to inspection and complete packaging.
ELECTROPLATING:
formation of a negative copy of the Glass Master to form a Stamper.
The electroplating process involves several steps. First, the
Glass Master is immersed in an electroplating bath to produce
a negative copy referred to as a Metal Master, or the Father.
It undergoes further replication to ultimately produce another
negative copy referred to as a Stamper, or the Son. The end product
of the electroplating process is a rough, unfinished replication
template.
STAMPER PREPARATION:
to ensure high-quality molding, the back of the Stamper is polished
and its outer and inner edges are trimmed. MOLDING: the mold
containing the Stamper (negative copy of data pits) is injected
with plastic melt at a high temperature and pressure to form
a positive plastic copy of the Metal Master, known as the Raw
Disc.
METALLIZATION:
the process of sputtering a Raw Disc under vacuum producing an
aluminum coating. The coating forms a reflective layer that allows
a scanning laser beam to read the information from the CD.
SPINCOATING:
the process of applying an ultra-violet sensitive lacquer layer
over a metallized disc while spinning the disc at a high rate
of speed. This process produces a smooth, thin layer of lacquer
covering the metallized disc. The lacquer is then cured under
an ultra-violet light. Spincoating provides a protective layer
for the information on the disc. It also provides a smooth surface
for printing.
QUALITY CONTROL:
The compact disc is tested for signal strength and decoding errors
in compliance with the Sony/Philips Red Book standards.
PRINTING: Silk
screening or pad printing label information containing text and/or
graphic elements onto the lacquered surface of the disc. Once
the label is transferred to the disc, it is cured under the ultra-violet
light. Depending on the production process, printing can be performed
either in-line (usually for one or two color prints), or off-line
(three or more colors).
INSPECTION:
final check for possible physical defects resulting from any
of the production steps.
PACKAGING:
placing the compact disc (on a tray), along with information
booklet, into a Jewel Box. The Jewel Box can be shrink wrapped,
placed in a corrugated long box, or packaged in a blister PVC
container.
DUPLICATED CD (CD-R)
CD-R is a one time recordable medium and are run
directly from your mastered CD-R or Digital Audio Tape (DAT)
at one or two times speed. The lack of computer checked mastering,
makes this process dependant upon the supplied master. The reliability
could be in question resulting from data errors from the original
source equipment.
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