Patent Application
20080049594
The preferred embodiments of a single-sided double layer disc with improved protective layer and a manufacturing method of the same according to the invention will be described in detail with reference to the drawings, in which like reference numerals denote like elements.
A write-once, single-sided double layer disc, like DVD-R dual, is used as an illustration in the following description. Referring to
The boding layer 13 is used for bonding the first access layer 1 and the second access layer 2, and the two access layers are bonded with the second recording layer 121 of the second access layer 2 facing the first access layer 1. The bonding layer 13 is between the semi-reflective layer 112 and the protective layer 14. The protective layer 14 is laminated between the second recording layer 121 and the bonding layer 13; the material of the protective layer 14 can be metal or semiconductor material. For example, the material of the protective layer 14 can be a noble metal such as gold, silver, platinum, palladium, rhodium, or iridium, or a semiconductor material like silicon, gallium, indium, or germanium; it can also be titanium or titanium alloy like silver-titanium or aluminum-titanium, molybdenum, or tantalum. Since the aforementioned materials for the protective layer are dense, a relatively-thinner protective layer 14 can prevent reaction between the bonding layer 13 and the second recording layer 121; for example, the thickness of the protective layer 14 can be less than 20 nm, preferably less than 10 nm, and more preferably less than 5 nm.
A manufacturing method of the aforementioned single-sided double layer disc according to an embodiment of the invention is herein described. First, a first access layer 1 and a second access layer 2 are prepared. For example, the preparation of the first access layer 1 includes steps of: providing a first substrate 11; forming a first recording layer 111 on a first coating surface 11a; and forming a semi-reflective layer 112 on the first recording layer 111. The steps for preparing the second access layer 2 include: providing a second substrate 12 having a second coating surface 12a; forming a reflective layer 122 on the second coating surface 12a; and forming a second recording layer 121 on the reflective layer 122.
Next, a protective layer 14 is formed on the second recording layer 121 and the material of the protective layer 14 is as stated in the above and will not be described herein. It is to be noted that the protective layer 14 can be formed by DC sputtering or RF sputtering, preferably by DC sputtering. Last, the first access layer 1 and the second access layer 2 are bonded together by a bonding layer between the first access layer 1 and the protective layer 14, and in particular, the bonding layer is between the semi-reflective layer 112 and the protective layer 14, wherein the second recording surface 121 is arranged to face the first access layer 1 when the two access layers are bonded.
With the single-sided double layer disc having an improved protective layer and the manufacturing method thereof according to the invention, the production cost is lowered because the material of the improved protective layer can be coated by DC sputtering, for which the production parameters are easy to control, and the price of the aforementioned materials for the protective layer is cheaper than the price of conventional dielectric materials. Moreover, due to the characteristic of the materials, a relatively-thinner protective layer can effectively prevent reaction between the bonding layer and the second recording layer, and therefore, in the fabrication process, the time that the disc stays in the sputtering chamber is shorter, which in turn minimizes the warping and deforming of the disc caused by the high-temperature in the sputtering chamber. And thus, the yield of disc is effectively increased.
While the invention has been described by way of example and in terms of the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. In other words, it is intended to include equivalent modifications and changes of the above embodiments without departing from the spirit and scope of the invention as would be apparent to those skilled in the art. For example, although DVD-R dual is used as an illustration in the above description, the invention can also be implemented to other single-sided double layer discs, e.g. HD DVD-dual, or to a multi-layer disc. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such equivalent modifications and changes.
| Number | Date | Country | Kind |
|---|---|---|---|
| 95131313 | Aug 2006 | TW | national |
