Dynamic magnetic information storage or retrieval – Head mounting – Disk record
Reexamination Certificate
1999-10-29
2001-05-08
Renner, Craig A. (Department: 2652)
Dynamic magnetic information storage or retrieval
Head mounting
Disk record
C360S125330, C360S234500, C360S234600, C360S244300, C360S246100
Reexamination Certificate
active
06229673
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a magnetic head assembly for information recording and reproduction on and from a magnetic disk using a magnetic head, a method of manufacturing the same and a magnetic disk apparatus, and, more particularly, to a magnetic head assembly using a thin-film head chip, a method of manufacturing the same and a magnetic disk apparatus.
BACKGROUND ART
A magnetic disk apparatus is a storage device which allows an actuator to position the magnetic head to a desired track on a rotating magnetic disk to thereby read data from that track or write data on that track by the magnetic head.
This magnetic disk apparatus is widely used as an external storage device. To meet the recent demand of downsizing of computer systems, there is a demand for a small magnetic disk apparatus with a large capacity. The size of magnetic disks tends toward 3.5 inches or 1.8 inches from 5.25 inches.
The size reduction of the magnetic disk apparatus and the large capacity require high-density recording. When high-density recording is performed, however, the magnetic force lines of a magnetic disk medium become short, so that it is preferable that planar recording or perpendicular recording be performed with the floating amount of the head set as small as or below the order of microns, or that perpendicular recording be performed with the head brought in contact with the magnetic disk.
In the case where the floating amount of the head is small or the head is brought in contact with the disk, if the head is heavy, the trackability to undulations or protrusions of the magnetic disk medium decreases on the order of microns.
If the load of the head is increased to improve this trackability, on the other hand, the force of contact with the protrusions of the magnetic disk medium increases, increasing the risk of head crash and medium crash.
Therefore, as the mass of the head decreases and the load of the head decreases, the trackability to a magnetic disk medium increases, so that high-density recording becomes possible with the reduced floating amount of the head or the head brought in contact with the medium.
FIGS.
1
(A),
1
(B) and
1
(C) are diagrams showing the structure of a conventional magnetic head, and
FIG. 2
is a diagram illustrating a fabrication process for the head.
As an example of a contact type perpendicular recording head, a flexible magnetic head
9
as shown in FIGS.
1
(A-C) has been proposed (see Japanese Unexamined Patent Publication No. 178017/1991, for example).
In this head
9
, as shown in FIG.
1
(B), a main pole (main magnetic pole)
90
is formed vertically in a dielectric flexure body
96
of aluminum oxide or the like, a yoke
91
connected to this pole is formed horizontally, a back stud
93
connected to this yoke is formed vertically, and a return yoke
94
connected to this stud is formed horizontally, those components constitute a reluctance path. This path ends at a high reluctance gap
95
between the main pole
90
and the return yoke
94
.
A spiral coil is inductively coupled to the yoke
91
, both ends of the coil
92
connected via lead conductors
97
to bonding pads
98
.
This head is called a probe type head, which is fabricated with thin-film forming technology and can be made very small. For instance, as shown in FIG.
1
(A), the head
9
has a width D of 0.5 mm, a thickness B of 0.05 mm, a length A of 12.5 mm, and mass of 100 micrograms.
By attaching such a head
9
to an arm, low mass and low load of the head become possible, thus ensuring high-density perpendicular recording in tracking with the undulation of the magnetic disk medium.
This head
9
is formed as an integrated unit using thin film and photolithography technologies. As shown in
FIG. 2
, many heads are formed on a polished wafer
9
-
1
of barium titanate or the like in the order of microns through tens of steps by sputtering, vapor deposition, plating, chemical deposition, ion beam deposition and etching, etc., and those heads are scribed to be individual heads.
But, the prior art has the following problems.
(1) The greater the number of heads formed on the wafer
9
-
1
is, the lower the cost becomes. However, since the lead conductor portion is formed integrally in the prior art, the number of heads formable on the wafer
9
-
1
is limited; for example, only about 270 heads can be formed on a 3-inch wafer. This significantly increases the cost of the heads.
(2) If the heads are large, the number of defects in the heads cut out of the wafer
9
-
1
increases; for example, even if the lead conductor portion alone is defective, the whole head becomes defective. This further increases the cost of the heads.
DISCLOSURE OF THE INVENTION
It is therefore a primary object of the present invention to provide a magnetic head assembly designed to increase the number of heads formable on a wafer to thereby lower the cost of the heads.
It is another object of the present invention to provide a magnetic disk apparatus designed to increase the number of heads formable on a wafer to thereby lower the cost of the heads, thus reducing the cost of the apparatus.
It is still another object of the present invention to provide a magnetic head assembly designed to increase the number of heads formable on a wafer and to reduce thin-film forming steps, thereby further reducing the cost of the heads.
It is a further object of the present invention to provide a magnetic disk apparatus designed to increase the number of heads formable on a wafer and to reduce thin-film forming steps for further reduction in the cost of the heads, thus further lowering the cost of the apparatus.
It is a still further object of the present invention to provide a method of manufacturing a magnetic head assembly, which facilitates assembling of the assembly even if the number of heads formable on a wafer is increased.
A magnetic head assembly according to the present invention, to be mounted to an arm for recording and reproducing data on and from a magnetic disk, comprises a head chip having a lamination of an insulating layer, a magnetic pole, a coil and a terminal portion of the coil formed of thin films; and a flexible support body having a terminal portion to be connected to the terminal portion of the head chip and attached to the arm, for supporting the head chip.
A magnetic disk apparatus according to the present invention comprises a magnetic disk; a spindle motor for rotating the magnetic disk; an actuator with an arm, for moving the arm in a direction intersecting tracks of the magnetic disk; a magnetic head assembly mounted to the arm for recording and reproducing data on and from the magnetic disk, the magnetic head assembly including a head chip having a lamination of an insulating layer, a magnetic pole, a coil and a terminal portion of the coil formed of thin films, and a flexible support body having a terminal portion to be connected to the terminal portion of the head chip and attached to the arm, for supporting the head chip.
According to the prior art, since the magnetic head assembly is directly mounted to the arm, the magnetic head assembly is given a flexibility and the lead conductor needs a length for that amount, requiring a long head flexure body. However, thin-film lamination is merely necessary for only a low reluctance path primarily including a magnetic pole and the coil, and the lead conductor portion can be formed by another means.
The length of the low reluctance path including the magnetic pole and the coil is merely about {fraction (1/20)} of the entire length, and it is useless to form the other portion on a wafer in tens of steps.
According to the present invention, therefore, the low reluctance path primarily including a magnetic pole and the coil, which should be formed on a wafer, are provided on the wafer using thin-film lamination technology and the other portion or the lead conductor portion is formed separately by a flexible support body to allow the number of head portions formable on a wafer to be increased, thus ensuring cost reduction.
As this design
Hiyane Masao
Kasamatsu Yoshiharu
Nakamura Yukio
Shinohara Masayoshi
Takahashi Minoru
Fujitsu Limited
Greer Burns & Crain Ltd
Renner Craig A.
LandOfFree
Magnetic head assembly with contact-type head chip mounting... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetic head assembly with contact-type head chip mounting..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic head assembly with contact-type head chip mounting... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2567778