Good points as applicable to CD discs where the metal layer may be protected
by only a few micrometer thick protective layer. I am not sure that the gold
vs. silver issue is as significant for DVD where the information layer,
including metal, is sandwiched between two 0.6 mm thick half discs that
isolate it from harmful chemicals. Of course, the bonding layer must extend
fully to the rim.
Media Sciences, Inc.
> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:[log in to unmask]] On Behalf Of [log in to unmask]
> Sent: Wednesday, April 26, 2006 8:47 AM
> To: [log in to unmask]
> Subject: Re: [ARSCLIST] TY vs Mitsui
> How much of an error rate difference are we talking about?
> For sure, when you burn a disc, you want a low error rate and no E22 and
> E32 errors. However, all other things being equal if we are talking about
> BLER of 0.5 versus BLER 3.0, this is not an issue.
> I have burned a large variety of discs on different burners and different
> speeds for the research I have performed. The TY/cyanine does tend to
> produce a BLER <1 on many occasions. The Mitsui/MAM can attain this, but
> the BLER is usually slightly higher (in the 2 to 3 range).
> That being said, gold metal layer will not corrode, silver alloy will.
> Phthalocyanine dye is very stable to light, heat, RH and cyanine is not.
> These points are not theoretical.
> So, as Jerry briefly pointed out as well, here is a basic example:
> Disc A (gold metal/phthalocyanine): Initial Bler = 10.0
> Disc B (silver metal/cyanine): Initial Bler =0.2
> Disc A is very stable and over 10 years does not change. However, Disc B
> less stable and does change over the 10 years due to exposure to one or
> of the following: light, elevated temperature and relative humidity, high
> levels of pollutants from the atmosphere, or exposure from aggressive
> from poor storage enclosures.
> After ten years you have:
> Disc A (gold metal/phthalocyanine): Ten year Bler = 10.8
> Disc B (silver metal/cyanine): Ten year Bler =100.0
> Where would you rather be?