[CEATEC] TDK Closer to 1Tb/inch2 HDD Recording Density

Oct 6, 2009
Hideyoshi Kume, Nikkei Electronics
The read/write head made by integrating optical elements is moving above a disk. A transparent disk is used to make laser light visible.
The read/write head made by integrating optical elements is moving above a disk. A transparent disk is used to make laser light visible.
[Click to enlarge image]
The concept image of the head supporting the heat-assisted recording technology. The magnetic layer of a recording medium is heated by laser to lower its coercive field strength so that data can be written on the medium.
The concept image of the head supporting the heat-assisted recording technology. The magnetic layer of a recording medium is heated by laser to lower its coercive field strength so that data can be written on the medium.
[Click to enlarge image]

TDK Corp recorded and read data on and from a recording medium with a coercivity of 16kOe by using the "heat-assisted recording" technology, which is expected to enhance the areal density of hard disk drives (HDDs) to more than 1 Tbit/(inch)2.

The coercivity of 16kOe is much higher than the about 5kOe of existing products. TDK used an HGA (head ginbal assembly) integrated with laser elements, which is similar to the HGA the company announced in the past year. According to TDK, this is the first time that data has been recorded and read on and from an actual disk by using an HGA integrated with laser elements.

The disk rotation speed is 7,200rpm, which the company claims is the industry's record and is equivalent to that of existing 3.5-inch HDDs. The details of the technology will be announced at CEATEC JAPAN 2009, which will take place from Oct 6 to 10, 2009, at Makuhari Messe in Chiba Prefecture, Japan.

The heat-assisted recording is a technology to solve a problem called "thermal fluctuation." As the areal density of an HDD increases, magnetically-recorded data becomes more likely to be erased due to heat.

To prevent this problem from occurring, a recording medium with a high coercivity has to be used. But, when a coercivity is too high, it becomes impossible to record data by using existing magnetic recording heads.

The heat-assisted recording method enables to record data in such a case by heating a recording medium with laser to temporarily lower its coercivity.

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