Twenty-Layer Optical Disc Fabricated by Web Coating and Lamination

Abstract

We developed a new fabrication method for multilayer optical discs for the high-throughput production of such discs. We used web coating and lamination to prepare a stacked unit. The stacked unit was a layered structure consisting of a recording layer, a UV resin layer, a recording layer, and a pressure-sensitive adhesive layer. We obtained a 20-layer disc simply by laminating the stacked units 10 times. The transmittance of the 20 recording layers was 87% owing to the high transparency of the two-photon recording material. A scanning electron microscopy (SEM) image of the disc showed a clear multilayer structure. The recording layers of the disc were recorded using a pulse laser without interlayer cross write. The thickness variation of the transparent part of the disc was within ±2 µm, and the tilt angles of the disc satisfied the Blu-ray disc (BD) specifications.

A high transmittance optical recording material with long-term reliability for super-multilayer discs

“…[1][2][3][4][5] As a means of increasing the data storage capacity, several technologies have been reported, such as holographic technology, 6,7) near-field technology, 8,9) multilayer technology, [10][11][12][13][14][15][16] and others. [17][18][19][20][21][22][23][24] Among these, multilayer recording technology is a promising approach because it can utilize most technologies of the Blu-ray Disc™ system that is already in use as a commercial technology. 25) Because many recording layers are stacked in a supermultilayer disc, the intensities of the reading and recording lasers are attenuated at the deeper layers.…”