• slide 1

    Excellent flatness necessary for magnetic disks is attained by our sophisticated manufacturing technology and quality control.

  • slide 2

    The present invention relates to an aluminium alloy suitable for use as a substrate for magnetic disks and, in particular, to an improvement in the adhesion of electroless plating being the primer treatment for the covering with magnetic substance and the surface smoothness.

  • slide 3

    Magnetic disks made of aluminum alloys are used in hard disk drives (HDDs) because aluminum is non-magnetic, lightweight and grindable precisely.


About Hard Disk Drives

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. Aluminum substrates are used mainly for desktop PCs and digital home appliances.  

Hard Disk Drives Technology

Hard disk drive is the primary medium for memory storage in computers. It is commonly formulated on an aluminium or glass substrate base. Thin films of magnetic alloys are then sputtered on to the substrate and this will contain all the memory in the form of magnetic bits.

The orientation of magnetic bits determines the output signals which are then translated into binary signals for the computer to decipher information. Often media development progresses hand in hand with drive head development.

Hard disk drive come in several sizes, or form factors, depending on their application. Desktop PCs and home consumer electronics use the 3.5" form factor while laptop notebooks and other mobile applications employ smaller form factors like 2.5", 1.89", 1" and 0.85" media.


A typical HDD design consists of a spindle that holds flat circular disks, also called platters, which hold the recorded data. The platters are made from a non-magnetic material, usually aluminium alloy, glass, or ceramic, and are coated with a shallow layer of magnetic material typically 10–20 nm in depth, with an outer layer of carbon for protection. For reference, a standard piece of copy paper is 0.07–0.18 millimetres (70,000–180,000 nm).


Aluminium High Memory Disk Substrates


Magnetic disks made of aluminum alloys are used in hard disk drives (HDDs) because aluminum is non-magnetic, lightweight and grindable precisely. Aluminum substrates are less expensive than glass substrates, so they are used not only in personal computers but also in home electronics such as HDD recorders.


Aluminium High Memory Disk Substrates Process

HDD area densities have been growing at compound annual growth rate of 60 -- 100% for many years. This trend does not seem to be abating with growing demand for conventional computers and new emerging markets such as consumer electronics. SHDS continues to advance its technology to keep pace with this burgeoning market.

STEP 1 - Substrates

Substrates that not undergoing any process yet called BLANK


STEP 2 - Turning

Remove blank surface oxide layer, cut inner diameter (ID), outer diameter (OD), thickness, chamfer length, chamfer angle and chamfer radius disc


STEP 3 - Grinding

Control aluminium thickness, improve disc surface roughness and waviness

STEP 4 - Mekki

To plate a non–magnetic layer on surface, harden the surface and anti-corrosion on aluminium substrate


STEP 5 - Polishing

Finalise surface to improve roughness, waviness and remove plating defects on the disc surface to make it smooth and flat like glass


STEP 6 - Kensa

To inspect disc surface with AOI (Automatic Optical Inspection) machine



Inspection item including surface quality inspection and dimension inspection

STEP 8 - Packing

All disks that pass testing are then sealed in a vacuum package, ready for shipment to customers.

Disclaimer: Manufacturing flow may be modified depending on program requirements.

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