Monday, February 06, 2006

Technology/ Hard Disk Drive/ HDD Components 0 comments

(P.S: Sorry for any disturbances the advertisements above may have caused you)

I don't know about other investors but I sometimes find it very useful, particularly for manufacturing and product firms, to get a basic technical knowledge of the device being made or sold by the company. Besides being intellectually fulfilling, it also allows me to understand the degree of complexity of the product (hence the defensibility of the niche and the profit margin); furthermore an understanding of the various components that go into the product also gives an indication which are the high-margin parts and which are not. The hard disk drive is an excellent example, especially it such an inportant export of Singapore, with so many local listed precision engineering firms involved in its component production and assembly.

The hard disk drive basically consists of a circular disc (coated chemically), the platter, as the data storage medium. The platter is mounted on a spindle which spins the platter at high speeds to facilitate data tracking and access; the data is read by a read/write head operated by another actuator mechanism.

A view of the typical hard disk drive and its main components, followed by a description and examples of main local suppliers, below:

CASE & MOUNTING HOLES (where the cover is attached to the case and also where the HDD is securely attached to the HDD bay in the computer case)
- Most Singapore precision engineering companies are in this field. Seksun manufactures top plates (the top cover over the HDD, not shown above). MMI and Beyonics are key manufacturers for the baseplates. And who can forget Unisteel and its unexpectedly high-margin niche for the simple and yet necessary electropolished HDD fasteners that attach the various parts together?
- The casing is normally sealed to prevent contaminants from entering inside the HDD, and a special seal (usually tape) is secured to where the case and cover join. In a sense, this seal acts like a gasket. Relate this to Seksun's new form-in-place gaskets which satisfy this purpose in a more advanced way, suitable for micro-drives.

PLATTERS (both sides of each platter are used for storage of data.)
- Used to be aluminium, but the newer ones use glass or ceramics. As far as I know the key player here is SDK, or Showa Denko, a Japanese company based in Singapore.

SPINDLE (located in the center of all the platters, and is used to spin the platters.)
- Operated by a spindle motor. It is designed to spin at high speed. In order for a unique location on the platter to be reached, the spindle is responsible for circumferential movement, while the head actuator (see below) is mainly responsible for radial movement. Innovalues Precision makes parts for this segment.

HEAD ACTUATOR (a mechanical device for moving or controlling the actuator arm to move the heads around the platters.)
- Also known as voice coil actuators, which are powered by voice coil motors (VCM). Companies like Cheung Woh and Seksun produce VCM plates which house the VCM (you can see that at the bottom left hand part of the HDD above)

ACTUATOR ARM (a mechanical arm enabling the HDD read/write heads to extend over & in-between the platters for reading and writing to the HDD.)

SLIDER & HEAD (located at the end of the actuator arm and is the mechanism used to read and write to the platters.)
- The distance between the head and platter is very small, so small that the drive must be assembled in a clean room because one dust particle can throw the whole thing off. This sensitivity and accuracy is what causes only bigger companies to be able to repair hard drives simply because of the expense of a clean room.
- The suspension assembly is the mechanism that positions the read/write head above the rapidly spinning disks to maintain a consistent "flying height". The suspension must hold the head at a precise microscopic distance above the disk without allowing unintended movement of the head in any direction. It maintains the position of the head within a safe range during these periods to keep it from hitting the disk's surface. Magnecomp, of course, is a global leader in these suspension assemblies, and judging from the precision required, the barriers to entry look high.

(1) PC Technology Workshop: The HDD
(2) Hardware Central: Internal Hard Disk Drive Parts
(3) Magnecomp webiste: What is a Suspension Assembly?




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