6.
Miller indices are relevant to the ’754 Patent because many of the claim limitations
require certain crystallographic orientations. The (200) orientation [for the underlayer] and the (1120)
orientation [for the magnetic layer] are illustrated by the following figures:4
_ ~°~"···` i
$$1*11*
r'
'¥ ]§U]
a) b)
As explained below, the ’754 Patent explains how the (200) and (11 2 0) crystallographic orientations are
undesirable.
A magnetic recording layer, which is a collection of cobalt grains lying in a plane, has
several magnetic properties, including the following three characteristics which are featured in the ’754
Patent:
• Remanent coercivity (H,) which relates to the magnetic field strength necessary to
flip the magnetic poles from north/south to south/north.
• Remanent coercivity squareness (S*) refers to the sharpness of the transition
when the polarity of the grains is switched by an external field from north/south
to south/north.
• Remcment moment (M,) refers to the remaining magnetization in the direction of
an applied field when the external field is removed.
These three magnetic properties can be separately measured on a disk in the
circumferential and radial directions. That is, each of these three magnetic properties can be measured
both in a direction running from the center of the disk to the outside of the disk (i. e., radially), and in a
direction running along the circumference of the disk (i. e., circumferentially):
4 See Ex. C [David E. Laughlin et al., “The Crystallography and Texture of Co-Based Thin Film
Deposited On Cr Underlayers," IEEE Trans. Mag., Vol. 27, No. 6, November 1991, pp. 4713-17]
at 4714, Fig. 2 (entitled "Schematic Drawing of the low index planes and directions in (a) bcc and
(b) hcp.").
Case 1:04-cv-00418-SLR Document 219-2 Filed 11/28/2005 Page 2 of 4
7.
Radial Circumferential
Measurement Measurement
If the cobalt grains are randomly oriented on the disk, then the magnetic properties will
be the same in the circumferential and radial directions — i.e., the disk will be magnetically isotropic. If
the cobalt grains are physically oriented (i.e., such that they predominantly point in either the
circumferential or radial direction), then their magnetic properties will also be oriented, or anisotropic.
One way to make a disk anisotropic is to form circumferential grooves in the disk, such that the cobalt
grains orient themselves circumferentially along the grooves (under proper conditions). Following is an
illustration of randomly oriented (isotropic) crystals on an un—grooved disc, and circumferentially oriented
(anisotropic) crystals on a grooved disc:
A Q
e It , n Q
In- my I I _
Randomly Oriented { isotropic) Grains On Oriented Crystals (/xnisntrupictt On
Un—Gr¤0v¢d Disc Grtmvcd Disc
An "orientation ratio" ("OR") is a measure of how isotropic or anisotropic a disk is. It
represents the ratio ofthe magnetic properties in the circumferential direction to the magnetic properties
Case 1:04-cv—00418-SLR Document 219-2 Filed 11/28/2005 Page 3 of 4
8.
in the radial direction. A separate orientation ratio can be determined for each of the three properties (i. e.,
for coercivity, coercive squareness, and magnetic remanence). For any of these properties, an orientation
ratio of l means that, for that property, the disk is isotropic. The more anisotropic the disk, the greater the
orientation ratio.
II. THE ’754 PATENT
The ’754 Patent is directed to a substantially isotropic magnetic medium. In order to
produce a magnetic medium with substantially isotropic magnetic properties, the patent claims using a
particular layered structure, as illustrated below in Figure 5 of the ’754 Patent:
ummm: A 5*
Ovsrcum p 54
Magnetic Layer 53 p
Uvvdnrimr 52
(3:0: Soociayar 51
Subslmn 50
FIG. 5
’754 Patent at Figure 5. The bottom-most portion of Figure 5, labeled "50", is the substrate. A substrate
can be made from glass or an aluminum alloy. The patent discloses using a "seedlayer" formed directly
on top of the substrate. The "seedlayer" is made from chromium or a chromium alloy. The underlayer is
formed on top of the seedlayer. Then, the cobalt crystals of the magnetic layer are formed on top of the
underlayer. A protective overcoat and lubricant are formed on top of the magnetic layer.
Case 1:04-cv—00418-SLR Document 219-2 Filed 11/28/2005 Page 4 of 4
9.
III. PRIOR ITC PROCEEDINGS
In response to Cornice’s motion for summary determination of invalidity of the ’754
Patent in the prior ITC action, Seagate took several contorted claim construction positions in an attempt to
avoid invalidity. See Ex. D [Comice’s Motion for Summary Determination of Invalidity of the ’754
Patent]. Cornice’s summary determination motion asserted that there were a number of prior art
references that invalidated the ’754 Patent based on Seagate’s assumed claim constructions. See id
Furthermore, each of these prior art references describe the same layer structure described by the ’754
Patent (the ’754 Patent layer structure is illustrated in Fig. 5 above). Further, each of these prior art
references explicitly disclosed a media that exhibited magnetic isotropy. Accordingly, since the layer
structure of the ’754 Patent was not unique, Seagate had to craft additional functional limitations to claim
terms in order to attempt to preserve validity.
To illustrate, the following picture shows the layer structure disclosed by the "Ol
unless its definition of the term “alloy" is adopted:
F I G. 2
!\ 6 cmm oi-mlm
Cobalt Alloy
ZHIIKZII 5 ““g“°"“L“’"°'
IIIIIIIIIIIIIIIIII
YHKIIIIHIWKE 1 S°°°‘L""°'
2; M ......
I
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