Chemistry: electrical and wave energy – Processes and products – Coating – forming or etching by sputtering
Reexamination Certificate
2001-11-09
2004-08-17
VerSteeg, Steven (Department: 1753)
Chemistry: electrical and wave energy
Processes and products
Coating, forming or etching by sputtering
C204S192120, C427S402000
Reexamination Certificate
active
06776882
ABSTRACT:
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a method for producing hybrid disks, with a first substrate transparent at a given spectral band, as well as, succeeding it, a layer system semi-transparent in said band, further, again succeeding it, a further substrate transparent in said band and lastly, again succeeding it, a reflection layer system.
Reference is made to the documents found within the scope of the International Search, specifically:
EP 0 516 178 (JP 4353641)
EP 0 762 406 (U.S. Pat. No. 5,965,228; WO 9709715; JP 9265659)
JP 0714696 (Patent Abstract of Japan Vol. 1995, No. 09, 31 October 1995)
EP 0 467 705 (U.S. Pat. No. 5,490,131; JP-4364248)
U.S. Pat. No. 5,450,380
EP 0 834 874,
without any assessment of their significance for the present invention.
In
FIG. 1
is schematically represented the conventional structure of a hybrid disk, also known as Super Audio CD. The disk comprises a first transparent substrate
1
whose one face A
1
is disposed on the outside against ambient atmosphere. At its second face A
1/2
, disposed on the inside, a semi-transparent layer system
2
is provided which, in turn is in contact with its inner face A
2/3
on an adhesive substance layer
3
. The inner face A
3/5
of the adhesive substance layer is in contact on a further transparent substrate
5
, whose inner face A
5/6
is in contact on a reflection layer system
6
. The latter is conventionally protected against the ambient atmosphere by a protective layer
8
, for example a protective lacquer.
In the proximity of face A
1/2
an informational engraved data pattern is provided, a second in the proximity of face A
5/6
. Laserlight L within a predetermined spectral band, conventionally in the range between 600 nm and 800 nm, in particular between 630 nm and 780 nm, is applied onto the disk for reading out the data, as schematically represented in FIG.
1
. Said data is read out, for one, from the reflected partial beam from the semi-transparent layer
2
, for another, on the partial beam reflected on the reflection layer system. Either a single laser beam is employed for reading out the entire information, which subsequently is divided at the semi-transparent layer
2
, or two different laser beams are employed with specific wavelengths in said spectral band.
Within the scope of the present invention the structural formation of such hybrid disks is essential, and not the technique of reading out or applying the data; both are known.
It is evident and it is essential within the scope of the present invention, that the layering formation of the disk is asymmetric; while, on the one hand, the substrate face A
1
is at ambient atmosphere, on the other hand, a layer system, be that a protective layer
8
, be that the reflection layer system
6
, is at ambient atmosphere.
Substrate materials, which are employed for said disks, such as for example polycarbonate, when uncoated absorb relatively rapidly moisture from the environment. Thus, as readily evident in FIG.
1
and indicated with arrows F, an expansion of the outer substrate
1
results, wherewith the disk similar to bimetals according to
FIG. 1
bends concavely upwardly. When lowering the ambient air humidity said substrate
1
contracts, the disk bends according to the representation of
FIG. 1
, concavely downwardly.
This deformation is characterized by the so-called radial deviation. It is defined as the angular deviation of a beam reflected by the substrate face A
1
and for the DVD standard (DVD: Digital Video Disk) must not exceed ±0.8°. But heating to 30° at a relative air humidity of 95% causes a change of the radial deviation of about 1.2°.
It is in principle known to protect substrates of storage disks against moisture by means of a moisture protection layer. Therein coating methods are employed for applying this moisture protection layer, which do not fit into the production cycle of hybrid disks, since they replace, for example, protective lacquering or vacuum coating techniques, which differ fundamentally —in particular also regarding the coating times—from those which are employed for depositing the remaining layer systems on the hybrid disk. The following types of vacuum coating methods are differentiated:
Sputtering, therein reactive or non-reactive with all known electric supplying techniques, namely DC supply, AC+DC supply, AC supply or pulsed DC supply, each magnetic field-supported or not.
Arc evaporation by utilizing a low-voltage high-current arc discharge, through which target material is fused at the migrating base point (ARC Evaporation), again reactive or non-reactive, magnetic field-affected or not.
Thermal evaporation, such as electron beam evaporation, reactive or non-reactive.
CVD methods, in which material is deposited out of the gas phase without plasma enhancement,
plasma polymerization.
PE-CVD methods are basically called mixed methods, in which, such as for example in reactive sputtering, plasma-enhanced coating materials are deposited out of the gas phase.
If, within the scope of the present description the same type of vacuum coating methods are mentioned, the above listed types are addressed.
SUMMARY OF THE INVENTION
Under a first aspect of the present invention it is the task of providing a method of the above described type, which can be integrated simply into existing fabrication cycles for hybrid disks.
In the method of the type described in the introduction, in which the semi-transparent layer system as well as the reflection layer system is deposited with a vacuum coating method of the same type, this first task is solved according to the invention thereby that over the first substrate is deposited a moisture protection layer system transparent in said spectral band, in particular in the spectral band of 600 nm to 800 nm, comprised of at least one layer with a vacuum coating method, which, again, is of the same type.
If it is taken into consideration that the hybrid disks are fabricated in an in-line sequence of coating cycles, as for the deposition of the semi-transparent layer system and of the reflection layer system, it is evident that with respect to the installation configuration as well as also with respect to the clock control significant advantages are gained if the procedure as proposed is carried out.
According to prior known techniques, moisture protection layers are furthermore deposited onto storage disks with methods which required, for example, several treatment steps, which can only be automated and mastered with relative difficulties, such as for example through heat treatment, subsequently fluid coating, spin coating etc. or, for example, by means of plasma pretreatment, coating, subsequently heat treatment, to mention some examples.
Under a second aspect thus the present invention is based on the task of providing a method of the type described in the introduction, in which said moisture-caused problems, bending of the disk, are solved highly efficiently and so that they are relatively simply automatable and masterable.
For this purpose, the method described in the introduction is distinguished thereby that over the first transparent substrate a moisture protection layer system, transparent in said spectral band comprising at least one layer, is applied by sputtering.
Under a third aspect of the present invention the invention poses the task of solving said moisture-caused bending problems as efficiently as feasible.
This is solved in the method described in the introduction thereby that over the transparent substrate a moisture protection layer system is deposited comprised of at least one layer of substoichiometric silicon oxide and/or of at least one layer of silicon oxinitride.
Preferably at least two of said solutions, thus, application of a coating method already used for the disk production method, deposition of a moisture protection layer system by sputtering, deposition of a moisture protection layer system of substoichiometric silicon oxide and/or of silicon oxinitride, are applied at least combined in pairs or, in
Notaro & Michalos P.C.
Unaxis Balzers Aktiengesellschaft
VerSteeg Steven
LandOfFree
Method for producing a hybrid disk and hybrid disks does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for producing a hybrid disk and hybrid disks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing a hybrid disk and hybrid disks will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3339051