Dynamic magnetic information storage or retrieval – Head – Core
Reexamination Certificate
2001-10-17
2004-05-04
Ometz, David L. (Department: 2653)
Dynamic magnetic information storage or retrieval
Head
Core
C360S313000, C360S317000
Reexamination Certificate
active
06731461
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic head, more precisely relates to a magnetic head capable of efficiently radiating heat generated in an element for reproducing data and preventing overheat of the element.
These days, magnetic disk units having large memory capacity and high memory density are required. Further, precise and compact magnetic disk units are required. The element for reproducing date of a conventional magnetic head is shown in
FIGS. 18A
,
18
B,
19
A and
19
B.
FIG. 18A
is a sectional view of a recording and reproducing section “A” of a slider
10
seen from a disk-side face thereof;
FIG. 18B
is a plan view of the slider
10
seen from the disk-side face;
FIG. 19A
is a sectional view of the writing and reproducing section “A” seen from a side face of the slider
10
;
FIG. 19B
is a side view of the slider
10
.
In
FIGS. 18A and 19A
, a symbol
12
stands for an ALTIC (Al
2
O
3
TiC) substrate which is a basic material of the slider
10
; a symbol
14
stands for an alumina insulating layer; a symbol
16
stands for a lower shielding layer; a symbol
18
stands for an MR element layer, a symbol
20
stands for a lower magnetic pole; a symbol
22
stands for a coil for writing data; and a symbol
24
stands for an upper magnetic pole. Note that, the lower magnetic pole
20
acts as an upper shielding layer of an element for recording data.
In the conventional compact magnetic head, heat is generated in elements for reproducing and writing data and a problem of overheating the magnetic head is occurred.
FIG. 20
is a plan view of the coil
22
for writing data. In the coil
22
, a part “B” enclosed by an upper magnetic pole
24
is made compact so as to write data with high frequency. With this structure, in the part “B”, thickness of the coil
22
is made thinner and width of the coil
22
is made narrower. Therefore, in the conventional compact magnetic head, sectional area of the coil wire must be smaller, spaces between the coil wire must be narrower, so that the coil
22
is apt to be overheated. By overheating the coil
22
, the wire of the coil
22
is apt to be broken and a span of life of the coil
22
is made shorter.
To prevent the overheat of the magnetic head, several methods have been invented. For example, sectional area of the coil wire other than a part enclosed by a magnetic pole is made broader and spaces between the coil wire other than said part is made wider; area of a lower magnetic pole is made broader to improve heat-radiativity (see Japanese Patent Gazette No. 62-128011); a non-magnetizable metal is made contact with an upper shielding layer so as to act as a heat sink (see Japanese Patent Gazette No. 9-167314); a heat radiating layer made of a non-magnetizable material is provided in an MR layer (see Japanese Patent Gazette No. 7-210829); an insulating layer of a lead element layer is made of a material having high heat conductivity, e.g., silicon, diamond-like-carbon (see Japanese Patent Gazette No. 6-223331); and an insulating layer of a lead element layer is made of a aluminum nitride having high heat conductivity (see Japanese Patent Gazette No. 6-274830).
However, the conventional methods have following disadvantages.
For example, in the case of making the sectional area of the coil wire broader and making the spaces between the coil wire wider, heat generated in the part of the coil enclosed by the magnetic pole cannot be effectively restricted. In the case of using the material having high heat conductivity for the insulating layer of the lead element layer, heat is conducted toward an upper face or a bottom face of the layers so the heat cannot be effectively radiated. Further, in the case of making the non-magnetizable metal contact with the upper shielding layer as the heat sink, another manufacturing step other than forming the coil for writing data is required.
SUMMARY OF THE INVENTION
The present invention has been invented to solve the disadvantages of the conventional magnetic heads.
An object of the present invention is to provide a magnetic head for a large-capacity magnetic disk unit, which is capable of improving heat radiativity and preventing overheat of the magnetic head.
To achieve the object, the present invention has following structures.
The magnetic head of the present invention comprises: a slider having a disk-side face; an element for reproducing data; a shielding layer; a coil for writing data; magnetic poles; a heat radiating layer for radiating heat generated in the magnetic head; and an insulating layer for electrically insulating the heat radiating layer, wherein the heat radiating layer is provided near the element or the coil without touching the element, the shielding layer, the coil and the magnetic poles, the heat radiating layer is made of a material whose heat conductivity is higher than that of the insulating layer, and an end of the heat radiating layer is exposed in the disk-side face of the slider.
Preferably, the heat radiating layer and the coil are formed in the same layer.
Further, the preferable heat radiating layer is made of a non-magnetizable material including at least Pt, Au, Ag, Cu, Co, Ni, Fe or Al. With this structure, heat radiativity and electric-magnetic converting property of the magnetic head can be improved.
In the present invention, the heat generated in the magnetic head can be effectively radiated from the heat radiating layer, so that rising temperature of the magnetic head can be restricted and overheat of the magnetic head can be prevented. Therefore, a reliable magnetic head for a large-capacity magnetic disk unit can be provided. Since the heat radiating layer is provided without touching the element, the shielding layer, the coil and the magnetic poles, the electric-magnetic converting property of the magnetic head is not badly influenced. Further, the heat radiating layer can be formed in a step of forming the element, so the magnetic head of the present invention can be manufactured by a system for manufacturing the conventional magnetic heads.
REFERENCES:
patent: 5668688 (1997-09-01), Dykes et al.
patent: 6163436 (2000-12-01), Sasaki et al.
patent: 6381094 (2002-04-01), Gill
patent: 62-128011 (1987-06-01), None
patent: 06-223331 (1994-08-01), None
patent: 06-274830 (1994-09-01), None
patent: 07-210829 (1995-08-01), None
patent: 09-167314 (1997-06-01), None
patent: 2000057534 (2000-02-01), None
Hoshino Toshinori
Yamada Yuichi
Blouin Mark
Fujitsu Limited
Greer Burns & Crain Ltd.
Ometz David L.
LandOfFree
Magnetic head 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, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic head will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3228686