Most reliable standard hard drive.

[Rubycon]

Originally posted by: Concillian
Glass drives have far superior operating shock specs, which is the reason they're used in notebook size drives.)

Yes - they use them in ipods too.

 

[Old Hippie]

Also, I'd expect delamination issues to be isolated to glass substrate drives

What are the other platter materials?

 

[RebateMonger]

Originally posted by: Old Hippie
What are the other platter materials?

Wikipedia.org: Hard Disk Platter

"Platters are typically made using an aluminium or glass and ceramic substrate. In disk manufacturing, a thin coating is deposited on both sides of the substrate, mostly by a vacuum deposition process called magnetron sputtering."

 

[Concillian]

Originally posted by: Old Hippie

Also, I'd expect delamination issues to be isolated to glass substrate drives

What are the other platter materials?

I can tell you basic structure, but beyond that gets into pretty proprietary information.

Basic layer structure is
- a "soft" magnetic material (soft-underlayer, you can find information on this through a simple google search of perpendicular recording)
- then non-magnetic materials to set-up the grain size and crystal orientation of the hard magnetic recording layer
- then "hard" magnetic material for the recording layer
- then high energy carbon deposition for a protective layer
- finally a very thin layer of lubricant is bonded to the carbon to help improve head flyability and will help minimize drag

Each of these basic sections have highly proprietary material compositions and may be multiple actual layers to compose one 'section'. It is the development of the exact materials and deposition process parameters, coupled with advances in the head and the chips on the PCB (which I'm much less familiar with) that are the primary differences with each generation.

Note that the carbon and lubricant processes are pretty similar to what goes on razor blades these days to help them stay sharp longer and glide with less friction. They just use signficantly thicker layers than in hard disks.

 

[Old Hippie]

Thanks for the info gents. :thumbsup:

Computer technology is just amazing to me.

I'm always in awe that all these little pieces work together mostly flawlessly.

When I "see" what's involved with just the pieces we take for granted, I always think "Who in the hell thinks of this shit"?

It's just incredible.

 

[Idontcare]

Originally posted by: Concillian
Seagate doesn't manufacture disks in China. They assemble drives there, but the disks are all in Singapore or purchased from external media suppliers.

Do any of those external media suppliers manufacture disks in China?

 

[Concillian]

Originally posted by: Idontcare

Originally posted by: Concillian
Seagate doesn't manufacture disks in China. They assemble drives there, but the disks are all in Singapore or purchased from external media suppliers.

Do any of those external media suppliers manufacture disks in China?

Most of the media plants I'm aware of are in Singapore, Malaysia, and Thailand, but that doesn't mean there aren't any in China. I don't know. Anyway, if the problem indicated were from external suppliers it wouldn't likely be isolated to Seagate, since those same external media suppliers also supply to WD, Hitachi and Samsung.

There used to be a LOT of external suppliers, but there has been rather significant consolidation, there's really only a few now, and everyone keeps at least a little bit of their supply from third parties so they have a comparison point on their internal supply (and so management can twist the screws on their teams if the external supplier ever starts having any significant edge over the internal supply.)

 

[Russwinters]

Wel;, even if the disks are made at the same supplier that doesn't mean that them exact same materials are used. Different manufacturers use different coating depending on the engineered specs.

So just because the Seagate platters are failing in this manor /= WD failing in this manor.


Also, all platters now are either glass, or polymer/ceramic. Aluminum has not been used since before 2005 or so.


Originally platters where glass, but at the time they where having trouble with the adhesion layer materials with the glass, and also they could not make the glass smooth enough, so they moved to aluminum.

When perpendicular recording began to pick up, they made the move back to glass now that they had developed new technology to properly smooth the glass/ceramic materials, and also had developed better adhesion material.

The glass and ceramic is much lighter, amongst other things.

 

[Concillian]

Originally posted by: Russwinters

Also, all platters now are either glass, or polymer/ceramic. Aluminum has not been used since before 2005 or so.

I can personally attest to this being false. At least some manufacturers still make wide use of aluminum on their 3.5" drives (typical desktop size).

When perpendicular recording began to pick up, they made the move back to glass now that they had developed new technology to properly smooth the glass/ceramic materials, and also had developed better adhesion material.

It has nothing to do with total roughness, but more the orientation and shape of the roughness. It has a lot to do with longitudinal media requiring circumferential surface texture in order to get the right crystal orientation, while for perpendicular, surface texture orientation wants to be perpendicular to the plane of the surface, which is way easier to make.

For longitudinal media, you wanted to "stretch" the crystal in a particular direction (parallel to the surface) to add to the possible magnetism. In order to do this, you needed specific crystal orientation. The way this happened was to texture the substrate circumferentially. Then the right sputter materials would set up the appropriate crystallographic orientation for the magnetic layers.

Glass substrates were difficult to texture properly. So generally would be isotropic (fancy word for "not stretched" in any direction). As a result you couldn't reach the same density with the same design as used on circumferentially textured substrated. So glass media generally had direct disadvantages over aluminum aside from the increased cost.

In perpendicular media, the orientation is not as much of a concern.

The roughness type required for perpendicular is pretty easy to create in the sputter system. It's not circumferential, but more very small bumps, which is much can be done as a part of the sputter deposition process. So it can be created on any kind of substrate (that is smooth enough to begin with). The only differences then between glass and aluminum become the cost (aluminum being cheaper) and the mechanical performance parameters.