KODAK Ultima Lifetime Discussion
The KODAK Ultima CD-R disc is fundamentally the same
as the Gold Ultima CD-R media except the reflective layer material
is changed. The Ultima disc incorporates an alloy containing 24
karat gold which has been selected to provide maximum
performance, as well as improved stability relative to pure silver.
Media recording and playback performance is comparable to Gold
Ultima, and in fact, enhanced compatibility has been found with
the Ultima CD-R.
Ultima Stability
The CD-R industry has been offering customers the option
of purchasing media with a silver reflective layer in place of the
traditional gold layer. This has been done for a number of reasons
including increased reflectivity of the reflective layer, a disc
appearance similar to CD-ROM, and reduced manufacturing costs.
Customers are aware that everyday silver-based products (jewelry,
silverware, coins etc.) can oxidize and tarnish over time. For this
reason, there has been some skepticism about the stability of the
new silver-based CD-R discs. Kodak has shared these concerns,
and has opted not to offer a 100% silver-based CD-R product. We
have found that by using a stable gold alloy, the lifetime of the CDR media can be significantly enhanced.
The data life of storage media is a key consideration of
customers. It is also one of the most difficult parameters to
measure, and consequently one of the most misunderstood and
misleading parameters to be reported. By necessity, data lifetime
must be tested under accelerated aging conditions which are well
outside normal storage conditions. These results must then be used
to project an anticipated lifetime at actual storage conditions. The
key problem is how this projection is to be made.
Estimating media life would be difficult enough if lifetime
depended only on temperature. Unfortunately, humidity also plays
a significant role. Atmospheric pollutants could also have an effect,
but due to the encapsulation of the recording layers in a
polycarbonate/lacquer package this is considered a low risk, and is
usually ignored. During the early stages of evaluation, it is
common practice to select a single stressful condition which is
known to cause media failure within a manageable time span of
several weeks. In the case of silver-based CD-R media Kodak has
selected a condition which is quite extreme, consisting of a
temperature of 80°C, a relative humidity of 85%, and an
atmosphere of local air (which will contain some of the
aforementioned pollutants). We then assume that the longer the
media survives under these conditions, the more stable discs will
be under recommended storage conditions (25°C, 40%RH).
We have tested other manufacturers’ 100% silver media as
well as our own Ultima media under these conditions. The results
are summarized in Table 1.
Manufacturer 80/85 Survival Time Cause of Failure
Kodak Ultima > 3 weeks none yet
Company A <1 week extensive corrosion
Company B <1 week overall reticulation
Company C <1 week package delamination
Company D <3 weeks blisters
Company E <3 weeks patchy corrosion
Company F <3 weeks contrast loss
Table 1. 80/85 survival times for various manufacturers’ silver CD-R media
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These survival times cannot, by themselves, be used to
predict the lifetime of data on discs stored at recommended
conditions, but they are a good indicator on a relative basis.
Accurate lifetime estimates require extensive testing over
many months, at a variety of temperature and humidity conditions,
and using a statistical population of discs. The test plan which was
utilized to predict lifetime for Kodak’s Gold Ultima media required
over 210 discs, stored at 5 different temperature-humidity
conditions, and tested for performance on over 40 separate
occasions over the course of more than one year.
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Failure was considered to be the time at which the maximum BLER (block error rate) on a fully recorded
disc exceeded 50.
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At this time, survival tests at (80°C, 85%RH) have been
conducted on silver-based CD-R media. We have found that using
100% silver for the reflective layer produced media which failed in
less than 1 week and with failure highly dependent on the small
variations in the coating process conditions.
In the case of our Ultima reflective layer, our standard
coating conditions were able to produce media with a superior
survival time (in excess of 3 weeks at 80°C, 85%RH). We have
demonstrated that the Ultima reflective layer is both stable and
robust because it is resistant to small, but expected variations, in
the coating process.
The robust manufacturing process demonstrated with the
gold alloy will provide users of KODAK's Ultima media with an
additional degree of confidence that they are receiving a high
performance and uniformly stable product.
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Product Performance Specifications
KODAK Ultima CD-R media will meet the same specifications as
KODAK Gold Ultima CD-R media product. Some critical
specifications for the Ultima media have been measured on various
speed writers and compared with specification. The results are
summarized in Table 2.
Table 2 : Key parameters for Ultima CD-R media compared to specification
Parameter Orange Book Ultima
Specification Media
Stability
Shelf Light Stability 50Klux/3day pass
Archive Light Stability 50Klux/5day pass
Unwritten
RCb >.05 0.080 min.
PPb none 0.107 min.
PPb var. <+-15% ±7%
RGb 65% 72% min.
WCNRb >35dB 39dB min.
2X full surface write
Rtop >65% 71%
I3/Itop 0.3-0.7 0.36
I11/Itop >0.6 0.63
BLER <220 1
4X full surface write
Rtop >65% 71%
I3/Itop 0.3-0.7 0.33
I11/Itop >0.6 0.62
BLER <220 1
6X full surface write
Rtop >65% 71%
I3/Itop 0.3-0.7 0.33
I11/Itop >0.6 0.62
BLER <220 1
2X Power Series
I3/Itop @ β=0 none 0.30
I11/Itop @ β=0 none 0.64
3TMJIT @ β=0 none 31/32ns
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