MATRIX: Keeping Up to Unaxis upgrades their DVD pre-recorded line to HD DVD

For the disc manufacturer, the continuing market success of DVD9 is offset by increasing cost pressures on the disc manufacturer. The MATRIX2 line from Unaxis offers high uptime, consistent throughput and low resource costs – to meet the demands for reduced manufacturing costs. The newest version – “MATRIX HD” – now produces high density DVD with similar performance advantages.

Introduced two years ago to favorable reviews by clients around the world, MATRIX continues to establish its reputation as a “workhorse” for mass- production of pre-recorded discs. Continual evolution of the platform is ongoing. Working closely with key customers, development teams optimized the production processes and key disc manufacturing steps. The result – the MATRIX2 – is an enhanced DVD9 line with even better throughput and uptime characteristics than the previous MATRIX line.

“It’s this sort of constant attention to the production platform that helps our development team to consistently reduce investment and production costs for the disc manufacturer,” adds Peter Hillenbrand, Pre-recorded Solutions Manager at Unaxis. “At the same time, the high quality of the discs remains constant.”

Getting ready for HD – and Blu-Ray At the peak of success for DVD9 – firmly entrenched as the movie standard in North America, and making tangible gains every month in both the Asian and European markets – both the industry and the Hollywood movie studios are already gearing up for the next generation format based on technology: HD DVD.

1 “HD DVD was under development even before DVD came out and offers more of what makes the original DVD so seductive – superior visual and sound quality, and even more storage capacity,” adds Hillenbrand. “Of course, with a blue laser, all the production specifications become a bit tighter, but maintain a similar physical structure with back-to-back bonding of two 0.6 mm substrates.”

HD DVD is only one half of the biggest topic in the industry today. The other half is ’s Blu-Ray (BD) format, the other main high-density contender for the next generation disc standard. With all the same performance features as HD DVD (but even more storage capacity), BD has a different physical structure that bonds a 1.1 mm substrate with a 0.1 mm cover layer. This structure will require significant changes to disc production equipment because of the needed cover layer. Unaxis is currently developing a MATRIX replication line for Blu-Ray production, which will be available soon.

MATRIX does it all Whatever the format and whatever the production specifications, what has not changed in DVD production is the continued pressure to keep reducing manufacturing costs. High uptime, consistent throughput and low resource costs are fundamental performance standards demanded by the industry. The concept for the new MATRIX HD line integrated these parameters.

“It doesn’t matter if you need to manufacture DVD or HD DVD, the MATRIX line does it all,” exclaims Hillenbrand. “Manufacturers running a MATRIX line for DVD9 now can rest assured – switching to HD DVD is not a big deal. No hardware changes to the MATRIX platform are necessary, all you need to do is adjust some of the current production settings.”

At the start of the HD project, the MATRIX product development teams took advantage of Unaxis’ industry-leading technology expertise in metallizing and

2 bonding to put together a compact (23 m2 including two injection molders) and mechanically reliable line with unbeatable performance features: • Best process stability: proven at major brand production sites, the vacuum bonder is very stable and meets all production specifications for HD DVD • Lowest cost per disk: the high-performance ARQ 931 cathode can sputter over 1 million discs with one silver target • Highest throughput: 2.5 seconds for DVD, currently 3-4 seconds for HD DVD

A proven process for all pre-rec formats The individual modules of MATRIX undergo constant improvement and performance enhancement. Based on Unaxis strengths in vacuum bonding and metallizing, each production phase is the result of close cooperation with key technology leaders and exhaustive testing by disc manufacturers.

Molding: Because of the smaller pits and narrower pit tracks used for DVD and HD DVD substrates, the production tolerances are much tighter. Absolutely uniform pit replication from inner to outer radii – and low radial (± 0.8°) and tangential deviations (± 0.3°) – during molding are necessary for high signal performance. In addition, the higher molding temperatures ask for longer cooling times and also prolongs the overall cycle times for HD. Of course, the line configuration must meet the manufacturer’s throughput needs. All the major injection molding systems currently available on the market are compatible with the MATRIX lines.

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Cooling: The vertical cooling system developed for MATRIX ensures the best cooling capacity combined with a compact module footprint. The spindle cooler provides efficient and homogeneous cooling of discs coming directly from the injection molders. They are rotated for even and optimal heat reduction to 30° C. Both the L0 and L1 disc halves are carried on cooling tracks for about 100 seconds, then pick and place grippers move the stable discs to the next stage.

Metallizing: Pre-recorded formats require mainly the sputter deposition of two layers: the semi-reflective L0 and the reflective L1 layers. The coating materials used for these layers include aluminum, silicon, silver and silver alloys. A MATRIX line can be configured with dual or single metallizers, depending on throughput needs, type of sputter target, and initial investment budget: • Single metallizer sputtering is appropriate when silver alloy and aluminum targets are used for the L0 and L1 layers. The production advantages are obvious – less investment, less complexity and a smaller line footprint. • Dual metallizer sputtering (simply a matter of adding another metallizer, no hardware or software modifications required) is used to sputter Ag/Al, Al/Al, Au/Al, or Si/Al layers on the L0 and L1 disc halves.

The enhanced sputter cathode technology (ARQ 931) from Unaxis enables a single ”DVD Silver” target to now sputter over one million L0 layers! Under normal production runs, this means only one target change per month!

Bonding: The “wet-to-wet” vacuum bonding process applies UV resin to both DVD halves; then spin coats, aligns, and joins them in a vacuum chamber (to prevent air getting trapped between disc halves). Compared to conventional bonding technologies, the space layer is already set with the spin coating, rather than the bonding step. This assures a very consistent space layer

4 thickness between the disc halves thanks to spinning without capillary forces. Other advantages include: • Space layers conform to DVD specs (overall thickness specification ± 10 µm, space layer specification on track ± 4 µm) and HD DVD specs (overall thickness spec ± 5 µm, space layer spec on track ± 2 µm) • Optically attractive lacquer appearance around the center hole • No moving parts near the disc

UV curing: After bonding, the UV resin is cured by an integrated UV dryer in a 6-stage “wet-to-dry” process. Prior to curing, the discs ‘relax’ on trays for 5 cycles. The “light corridor” technology developed by Unaxis assures homogenous disc curing; rotating is unnecessary. The advantage of a pure UV dryer is the lower curing temperature, which diminishes “dishing” of the disc. The station is also water-cooled, further reducing penetration of heat into the replication line environment. Finally, a special reflector ensures optimal edge drying of the disc.

Inspection: Because every line is only as good as its output, MATRIX provides a 100% quality control capability to test every disc: • Mechanical testing – consistency of the space layer thickness, radial (“dishing”) and tangential (“tilting”) deviation of the disc to assure the disc is absolutely flat; detection of any distortions or bubbles in the pressed disc or in the adhesive resin in the space layer • Optical testing – assures that the semi-reflective (L0) layer corresponds to the established reflection window values, and that the reflective (L1) layer is also flawless

“Whether you want to produce DVD or HD DVD, the performance statistics are remarkable,” adds Hillenbrand. “However, the most convincing argument for MATRIX is the market acceptance our pre-recorded production solution – the MATRIX2 – continues to enjoy.”

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For more information please contact your local representative on our website at http://datastorage.unaxis.com/en/contacts.asp.

A crucial production step – bonding for DVD and HD DVD

A key part of MATRIX’s performance is the reliability of the bonding process. Here a summarized overview of the patented Unaxis solution:

Spin coating • Disc halves are placed in the spin cups • The UV resin is applied on the halves and spin coated at high rpm

Bonding • Disc halves are placed in bonding pads and centered by pins • A servo-controlled pin movement ensures precise alignment and joining of the two halves • During venting the two halves are pressed together at the center to enhance the disc’s visual appearance • Lid opens, and the gripper picks up the bonded disc to place on the UV tray

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