Sony Corp developed a magnetic tape with an areal density of 201Gbit/(inch)2 in collaboration with IBM Zurich Laboratories in Switzerland.
In terms of magnetic tape cartridge, the new tape can realize about 330 Tbytes, which means an areal density about 20 times higher than that of existing cartridge products. This time, Sony developed a recording medium, tape, etc, and IBM Zurich Laboratories was responsible for drive technologies such as a magnetic head, servo control technology, etc.
For the magnetic layer of the new tape, a "nano-grain magnetic film," which has minute magnetic particles (size: about 7nm on average), was employed. Sony developed a nano-grain magnetic film of the same size in 2014. This time, based on the film developed in 2014, the company increased its length and reliability so that it can be commercialized.
Improvement of sputtering conditions
The lengths of the tapes of the existing tape cartridge products are shorter than 1,000m. For example, the "LTO7" tape cartridge has a tape length of 960m. On the other hand, the newly-developed product has a tape length of 1,000m. The longer tape was realized by improving production technologies.
The existing magnetic tape products are made by using mainly a coating method. On the other hand, Sony attaches a magnetic material to the base film by using a sputtering method to form a magnetic layer.
With the coating method, a magnetic layer is formed by mixing a magnetic material with an adhesive binder and applying it to the base film. The sputtering method does not require a binder, making it easier to increase storage capacity.