Magnetic Disk Aluminum Substrates (MD)
Hard disk drives (HDD) are built in to a variety of digital devices such as computers, video recorders and car navigation systems, supporting the current IT networked society as an important device for storing increased digital data.
Large size data such as high resolution photos and hi-vision video are also stored on HDDs, thus the recording sizes are dramatically increasing.
HDDs consist mainly of a magnetic disk installed to a motor. Magnetic disks are created using thin film magnetic layer coated to the surface and a aluminum substrate. (Photo 1).
Aluminum substrates are used mainly for desktop PCs and digital home appliances.
Writing data to media is done using a magnetic head, and the distance between the head and the substrate surface is several nanometers. This distance is made even smaller in order to increase the recording size (Photo 2).
In order to manufacture these substrates, high cleaning and nanolevel polishing technology is essential. Manufacturing is done in a very clean cleanroom, achieving a nanolevel roughness, microlevel waviness and flatness.
- Aluminum substrate
Toyo Kohan Kudamatsu Plant (Yamaguchi Prefecture): 6.00 million sheets/month
Toyo-Memory Technology (Kulim, Malaysia): 2.50 million sheets/month