Title: Method of manufacturing a thin-film magnetic head
Abstract: The invention allows a thin-film magnetic head that meets specifications required by the customer to be provided in a short period of time and manufacturing costs to be reduced. A slider includes a first surface and a second surface each facing opposite directions. Two magnetic head element portions are formed in the slider near an end face orthogonal to the direction of air flow. One of the element portions is placed to face the first surface. The other element portion is placed to face the second surface. The element portions are placed in symmetrical positions with respect to a place parallel to the first and second surfaces. On the end face four pad-shaped electrodes are provided for electrically connecting the two element portions to an external device. The electrodes are selectively connected to any of the element portions through four conductors.
Patent Number: 6,892,442 Issued on 05/17/2005 to Sasaki
| Inventors:
|
Sasaki; Yoshitaka (Yokohama, JP)
|
| Assignee:
|
TDK Corporation (Tokyo, JP)
|
| Appl. No.:
|
101853 |
| Filed:
|
March 21, 2002 |
Foreign Application Priority Data
| Oct 02, 1998[JP] | 10-281704 |
| Current U.S. Class: |
29/603.07; 29/603.13; 29/603.14; 29/603.15; 29/603.16; 29/603.18; 29/846; 360/122; 360/126; 360/234.5; 360/234.7; 360/245.8; 360/245.9; 360/317; 427/127; 427/128 |
| Intern'l Class: |
G11B 005/12.7; H04R031/00 |
| Field of Search: |
29/60307,60313-60316,603.18
360/121,122,126,317,234.5,234.7,245.8,245.9
427/127,128
|
References Cited [Referenced By]
U.S. Patent Documents
| 5146379 | Sep., 1992 | Iwata et al.
| |
| 5694677 | Dec., 1997 | Tsunoda.
| |
| 5798890 | Aug., 1998 | Fontana, Jr. et al.
| |
| 5896249 | Apr., 1999 | Fontana, Jr. et al.
| |
| 6198600 | Mar., 2001 | Kitao et al.
| |
| Foreign Patent Documents |
| A-61-2965/18 | Dec., 1986 | JP.
| |
| A-3-95715 | Apr., 1991 | JP.
| |
| 04082005 | Mar., 1992 | JP.
| |
| A-6-203330 | Jul., 1994 | JP.
| |
| A-8-87848 | Apr., 1996 | JP.
| |
Other References
"Floating thin film head fabricated by ion etching method"; Nakanishi, T.; Kogure,
K.; Toshima, T.; Yanagisawa, K.; Magnetics, IEEE Transactions on , vol.: 16 , Issue:
5 , Sep. 1980; pp.: 785-787.
|
Primary Examiner: Kim; Paul
Attorney, Agent or Firm: Oliff & Berridge, PLC
Parent Case Text
This is a division of application Ser. No. 09/184,284 filed Nov. 2, 1998, now
U.S. Pat. No. 6,385,012.
Claims
1. A method of manufacturing a thin-film magnetic head, including the steps of:
forming a plurality of thin-film magnetic head element portions in a section
to be a main body wherein a thin-film magnetic head element is to be formed in
a substrate, the section having a first surface and a second surface facing directions
opposed to each other, the element portions including at least one first thin-film
magnetic head element portion having a pole tip that faces the first surface and
at least one second thin-film magnetic head element portion having a pole tip that
faces the second surface;
forming a plurality of electrodes, in the section to be the main body, to be
provided for a single thin-film magnetic head element portion, each of the plurality
of electrodes for electrically connecting any one of the element portions to an
external device; and
forming a plurality of conductors, in the section to be the main body, for electrically
connecting either the at least one first thin-film magnetic head element portion
or the at least one second thin-film magnetic head element portion to the electrodes,
the other of the at least one first thin-film magnetic head element portion or
the at least one second thin-film magnetic head element portion is not connected
to the electrodes.
2. A method of manufacturing a thin-film magnetic head according to claim 1 wherein
the at least one first thin-film magnetic head element portion and the at least
one second thin-film magnetic head element portion are placed in symmetrical positions
with respect to a plane parallel to the first and second surfaces in the step of
forming the element portions.
3. A method of manufacturing a thin-film magnetic head according to claim 1 wherein
the step of forming the electrodes is performed after the step of forming the conductors.
4. A method of manufacturing a thin-film magnetic head according to claim 1 wherein
the step of forming the electrodes is performed before the step of forming the conductors.
5. A method of manufacturing a thin-film magnetic head according to claim 1 wherein:
the thin-film magnetic head element portions each comprise: an induction-type
magnetic transducer having first and second magnetic layers magnetically connected
to each other and each made up of at least one layer and including pole portions
parts of which facing a recording medium are opposed to each other with a recording
gap layer in between, and thin-film coil placed between the first and second magnetic
layers; and the conductors are connected to the thin-film coil; and
the step of forming the element portions includes the steps of forming the first
magnetic layer, forming the thin-film coil on the first magnetic layer, and forming
the second magnetic layer on the thin-film coil.
6. A method of manufacturing a thin-film magnetic head according to claim 1 wherein
the thin-film magnetic head element portions each comprise a magnetoresistive element;
and the conductors are connected to the magnetoresistive element.
7. A method of manufacturing a thin-film magnetic head according to claim 1,
further including, before the step of forming the conductors, the step of forming
intermediate connecting portions for the respective thin-film magnetic head element
portions, connected to the element portions, to which the conductors are selectively
connected; wherein
the conductors are connected to the intermediate connecting portion corresponding
to selected one of the element portions.
8. A method of manufacturing a thin-film magnetic head according to claim 5 wherein
the step of forming the conductors is performed simultaneously with the step of
forming the thin-film coil.
9. A method of manufacturing a thin-film magnetic head according to claim 5 wherein
the step of forming the conductors is performed simultaneously with the step of
forming the second magnetic layer.
10. A method of manufacturing a thin-film magnetic head according to claim 5
wherein the step of forming the conductors is performed after the step of forming
the second magnetic layer.
11. A method of manufacturing a thin-film magnetic head sub-structure used for
manufacturing a thin-film magnetic head that comprises: a main body having a first
surface and a second surface facing directions opposed to each other wherein a
thin-film magnetic head element is to be formed; a plurality of thin-film magnetic
head element portions formed in the main body, and including at least one first
thin-film magnetic head element portion having a pole tip that faces the first
surface and at least one second thin-film magnetic head element portion having
a pole tip that faces the second surface; a plurality of electrodes, formed in
the main body, and provided for a single thin-film magnetic head element portion,
each of the plurality of electrodes for electrically connecting any one of the
element portions to an external device; and a plurality of conductors, formed in
the main body, and electrically connecting either the at least one first thin-film
magnetic head element portion or the at least one second thin-film magnetic head
element portion to the electrodes, and the other of the at least one first thin-film
magnetic head element portion or the at least one second thin-film magnetic head
element portion is not connected to the electrodes, the method including the step
of forming the at least one first thin-film magnetic head element portion and the
at least one second thin-film magnetic head element portion in a section to be
the main body.
12. A method of manufacturing a thin-film magnetic head sub-structure according
to claim 11 wherein the at least one first thin-film magnetic head element portion
and the at least one second thin-film magnetic head element portion are placed
in symmetrical positions with respect to a plane parallel to the first and second
surfaces in the step of forming the element portions.
13. A method of manufacturing a thin-film magnetic head sub-structure according
to claim 11, further including the step of forming the electrodes.
14. A method of manufacturing a thin-film magnetic head sub-structure according
to claim 11 wherein the thin-film magnetic head element portions each comprise
at least part of an induction-type magnetic transducer having first and second
magnetic layers magnetically connected to each other and each made up of at least
one layer and including pole portions parts of which facing a recording medium
are opposed to each other with a recording gap layer in between, and thin-film
coil placed between the first and second magnetic layers.
15. A method of manufacturing a thin-film magnetic head sub-structure according
to claim 11 wherein the thin-film magnetic head element portions each comprise
a magnetoresistive element.
16. A method of manufacturing a thin-film magnetic head sub-structure according
to claim 11, further including the step of forming intermediate connecting portions
for the respective thin-film magnetic head element portions, the connecting portions
being connected to the element portions, the conductors being selectively connected
to the connecting portions.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a thin-film magnetic head having a thin-film
magnetic head element and a plurality of electrodes for electrically connecting
the element to an external device and a method of manufacturing the thin-film magnetic
head, and to a thin-film magnetic head material used for manufacturing the thin-film
magnetic head and a method of manufacturing the material.
2. Description of the Related Art
Performance improvements in thin-film magnetic heads have been sought
with an increase in surface recording density of a hard disk drive. A composite
thin-film magnetic head has been widely used which is made of a layered structure
including a recording head (which may be called recording element in the following
description) having an induction magnetic transducer for writing and a reproducing
head having a magnetoresistive (MR) element for reading. MR elements include an
anisotropic magnetoresistive (AMR) element that utilizes the AMR effect and a giant
magnetoresistive (GMR) element that utilizes the GMR effect. A reproducing head
using an AMR element is called AMR head or simply MR head. A reproducing head using
a GMR element is called GMR head. An AMR head is used as a reproducing head whose
surface recording density is more than 1 gigabit per square inch. A GMR head is
used as a reproducing head whose surface recording density is more than 3 gigabits
per square inch.
In general, an AMR film is made of a magnetic substance that exhibits the MR
effect
and has a single-layer structure. In contrast, many of GMR films have a multilayer
structure consisting of a plurality of films. There are several types of mechanisms
of producing the GMR effect. The layer structure of a GMR film depends on the mechanism.
GMR films include a superlattice GMR film, a spin valve film and a granular film.
The spin valve film is most efficient since the film has a relatively simple structure,
exhibits a great change in resistance in a low magnetic field, and suitable for
mass production.
Besides selection of a material as described above, the pattern width such
as the MR height, in particular, is one of the factors that determine the performance
of a reproducing head. The MR height is the length (height) between the end of
an MR element closer to the air bearing surface (medium facing surface) and the
other end. The MR height is basically controlled by an amount of lapping when the
air bearing surface is processed.
Performance improvements in a recording head have been expected, too,
with performance improvements in a reproducing head. It is required to increase
the track density of a magnetic recording medium in order to increase the recording
density among the performances of a recording head. In order to achieve this, a
recording head of a narrow track structure has been desired to be manufactured
by processing the magnetic pole into the submicron order through the use of semiconductor
process techniques. The magnetic pole made of a magnetic material having high saturation
flux density has been desired in order to achieve the narrow-track recording head.
Another factor determining the recording head performance is the throat height.
The throat height is the length (height) of the portion (called pole portion in
the present invention) between the air bearing surface and the edge of the insulating
layer electrically isolating the thin-film coil. A reduction in throat height is
desired in order to improve the recording head performance. The throat height is
controlled as well by an amount of lapping when the air bearing surface is processed.
As thus described, it is important to fabricate a recording head and a reproducing
head appropriately balanced so as to improve performances of a thin-film magnetic head.
The manufacturing process of a thin-film magnetic head includes a wafer process
for forming thin-film patterns on a wafer as a substrate and a lapping process
for adjusting the throat height and the MR height by lapping. The wafer process
includes a number of mask steps, film forming steps by plating and sputtering,
etching steps by sputtering, dry etching, wet etching and so on, and lapping steps
by chemical mechanical polishing (CMP) and the like. The performance and characteristics
of the thin-film magnetic head may be modified by changing the track width of the
reproducing element and the track width of the recording element and so on. Therefore,
thin-film magnetic heads that meet a variety of needs of customers may be manufactured
by determining the track width of the reproducing element and that of the recording
element and so on, using masks that satisfy required specifications.
The manufacturing process of a thin-film magnetic head includes a number of steps
and it takes an extremely long period of time to manufacture one product. Therefore,
in order to manufacture the magnetic head having the performance and characteristics
that meet the needs of the customer, it is required to carefully work out a detailed
production plan so that the performance and characteristics of the magnetic head
may be changed by photomask selection.
However, the needs of the customers are not limited to those relating to
the performance and characteristics of the thin-film magnetic head that are determined
in the wafer process but embrace the needs relating to a slider for retaining the
magnetic head element and flying over the surface of a hard disk platter. The needs
of the customers for a slider may be, for example, whether to choose a side element
type slider or a center element type slider. The side element type slider is a
slider wherein a thin-film magnetic head element is formed near an end of the slider
in the direction orthogonal to the direction of air flow. The center element type
slider is a slider wherein a thin-film magnetic head element is formed in the center
of the slider in the direction orthogonal to the direction of air flow. The side
element type slider and the center element type slider are typical sliders. In
these days sliders are tend to be largely categorized into the above two types
for satisfying the demand for the flying characteristics over the surface of the
hard disk platter.
Reference is now made to FIG. 35 to FIG. 38 for describing the side element
type slider and the center element type slider.
FIG. 35 is a schematic front view of a surface of the side element type slider
in which a thin-film magnetic head element is formed. FIG. 36 is a schematic bottom
view of the air bearing surface of the side element type slider. In FIG. 36 the
arrow indicated with numeral
120 shows the direction of air flow. ‘LE’
indicates the air inflow end. ‘TR’ indicates the air outflow end.
In the side element type slider, as shown in FIG.
35 and FIG. 36, a thin-film
magnetic head element
111 is formed near an end of the slider in the direction
orthogonal to the direction of air flow, in the vicinity of an end face (end face
of air outflow end TR in this example)
110 orthogonal to the direction of
air flow. On the end face
110, four pad-shaped electrodes
112 are
provided for electrically connecting the magnetic head element
111 to an
external device. The four electrodes
112 are connected to the magnetic head
element
111 through four conductors
113. A rail
115 is formed
in the air bearing surface of the slider.
FIG. 37 is a schematic front view of a surface of the center element type slider
in which a thin-film magnetic head element is formed. FIG. 38 is a schematic bottom
view of the air bearing surface of the center element type slider. Numeral
120,
‘LE’ and ‘TR’ of FIG. 38 are similar to those of FIG.
36. In the center element type slider, as shown in FIG.
37 and FIG.
38, the thin-film magnetic head element
111 is formed in the middle of the
slider in the direction orthogonal to the direction of air flow, in the vicinity
of an end face (end face of air outflow end TR in this example)
110 orthogonal
to the direction of air flow. On the end face
110, four pad-shaped electrodes
112 are provided for electrically connecting the magnetic head element
111
to an external device. The four electrodes
112 are connected to the magnetic
head element
111 through the four conductors
113. The rail
115
is formed in the air bearing surface of the slider.
However, it is impossible to change between the side element type slider
and the center element type slider by simply changing a photomask in an intermediate
step in the manufacturing process of the thin-film magnetic head. It is therefore
required in related-art techniques to prepare different sets of masks for the respective
types of sliders and separately manufacture the sliders in volume.
In a hard disk drive for high density recording, a plurality of hard disk platters
such as four or six platters are placed on top of one another. FIG. 39 illustrates
an arrangement of thin-film magnetic heads in such a hard disk drive using a plurality
of platters. A plurality of hard disk platters
122 are held by a rotating
axis
121 in such a hard disk drive. The hard disk drive includes a thin-film
magnetic head (called up-type magnetic head in the following description)
123,
placed beneath the platter
122, whose medium facing surface faces upward;
and a thin-film magnetic head (called down-type magnetic head in the following
description)
124, placed above the platter
122, whose medium facing
surface faces downward. The up-type magnetic head
123 and the down-type
magnetic head
124 are coupled to a moving arm
125 through a suspension
126. The structural difference between the up-type magnetic head
123
and the down-type magnetic head
124 is the difference in position of the
reproducing element and the recording element.
Accordingly, two kinds of the side element type slider and the center
element type slider are each required for the up-type magnetic head and the down-type
magnetic head. The total of four kinds of thin-film magnetic heads are thus required.
In related-art techniques different sets of masks for twenty to thirty mask processing
steps are prepared for each kind of magnetic head and magnetic heads of each kind
are produced in volume. In a planned production, different mass-production lots
are prepared for the respective kinds of magnetic heads for manufacturing magnetic
heads that meet the customer's needs.
In the related-art techniques thus described, thin-film magnetic heads are produced,
using different masks or different mass-production lots for the respective kinds
of magnetic heads. As a result, a cycle time, that is, a period of time between
an order and a shipment is long and manufacturing costs are raised.
In particular, modifications and improvements in specifications of hard disk
drives
are made in a short period of time in these days. The customers of thin-film magnetic
heads therefore demand that the magnetic heads that meet desired specifications
are supplied shortly after the order. Consequently, the manufacturer of thin-film
magnetic heads is required to manufacture a variety of products in small quantities
that meet specifications demanded by the customers in a short period of time. The
above-mentioned problems are therefore noticeable.
Where the related-art techniques are used, there are many cases in which specifications
required by the customer are modified in the course of mass-production of thin-film
magnetic heads meeting the specifications and mass-production is required to be
restarted from the first step. Consequently, waste results and manufacturing costs
are raised.
Where the related-art techniques are used, the manufacturer of thin-film magnetic
heads estimates the number of products to be ordered by the customer and specifications
required and mass-produces magnetic heads prior to the order, in some cases, in
order to strictly maintain the product shipping schedule of the customer or to
beat the competitors by immediate delivery. However, the number of products ordered
by the customer and specifications required may go far beyond the estimates of
the manufacturer since the customer may quickly respond to the users' needs. In
such a case the manufacturer has to keep a number of undelivered stocks and to
produce new mass-production lots that meet the demand of the customer extremely
quickly, regardless of the average cycle time. Since the specifications required
by the customer or those of a final product change every six months, for example,
in these days, undelivered products in stock for a couple of months are equivalent
to nonconforming stocks to be wasted. Mass-production disregarding the average
cycle time affects the balance of the mass-production line and reduces the mass-production capacities.
Techniques of forming two head elements in one slider and selecting one
of the head elements for use are disclosed in Japanese Patent Application Laid-open
Sho 61-296518 (1986), Japanese Patent Application Laid-open Hei 3-95715 (1991)
and Japanese Patent Application Laid-open Hei 6-203330 (1994). The techniques allow
most of photomasks to be common and to manufacture the up-type thin-film magnetic
heads and the down-type thin-film magnetic heads.
In the techniques disclosed in the above-mentioned publications, however, the
two heads elements are placed so that the magnetic poles of the two head elements
face the same surface of the slider. Therefore, in order to form the up-type head
element for the center element type and the down-type head element for the center
element type in one slider through the techniques, there is no way but to place
the two head elements side by side in a position near the middle of the slider
in the direction orthogonal to the direction of air flow, in the vicinity of an
end face orthogonal to the direction of air flow. Therefore, it is impossible to
form the two head elements for the center element type both in the middle of the
slider in the direction orthogonal to the direction of air flow, according to the
techniques disclosed in the above-mentioned publications. Consequently, it is impossible
in some cases to supply thin-film magnetic heads that meet the specifications required
by the customer.
In Japanese Patent Application Laid-open Hei 8-87848 (1996), a technique is disclosed
for forming rails on both sides of a slider and forming two head elements so that
the tips of the head elements are placed on both of the rails. The technique allows
the single slider to read and write data on neighboring two magnetic disk platters.
However, the technique requires pad-shaped electrodes for the two head elements.
Eight electrodes are therefore required if the technique is applied to a composite
thin-film magnetic head. It is difficult to place the eight electrodes in one slider.
It is therefore difficult to implement the technique.
OBJECT AND SUMMARY OF THE INVENTION
The invention is designed to overcome the foregoing problems. It is an object
of the invention to provide a thin-film magnetic head and a method of manufacturing
the same and a thin-film magnetic head material and a method of manufacturing the
same for providing a thin-film magnetic head that meets specifications required
by the customer in a short period of time and reducing manufacturing costs.
A thin-film magnetic head of the invention comprises: a main body having a first
surface and a second surface facing directions opposed to each other wherein a
thin-film magnetic head element is to be formed; a plurality of thin-film magnetic
head element portions formed in the main body, each having a main part of the thin-film
magnetic head and including at least one first thin-film magnetic head element
portion whose tip faces the first surface and at least one second thin-film magnetic
head element portion whose tip faces the second surface; a plurality of electrodes,
formed in the main body, for electrically connecting any of the element portions
to an external device; and a plurality of conductors, formed in the main body,
for electrically connecting selected one of the element portions to the electrodes.
According to the thin-film magnetic head, selected one of the element portions
is electrically connected to the electrodes through the conductors. As a result,
thin-film magnetic heads of several types of specifications may be selectively provided.
In the thin-film magnetic head of the invention the first thin-film magnetic
element
portion and the second thin-film magnetic element portion may be placed in symmetrical
positions with respect to a place parallel to the first and second surfaces. The
place parallel to the first and second surfaces is an imaginary plane placed in
a midpoint between the first and second surfaces.
In the thin-film magnetic head of the invention the thin-film magnetic element
portions may each comprise: an induction-type magnetic transducer having first
and second magnetic layers magnetically connected to each other and each made up
of at least one layer and including pole portions parts of which facing a recording
medium are opposed to each other with a recording gap layer in between, and thin-film
coil placed between the first and second magnetic layers. The conductors may be
connected to the thin-film coil.
In the thin-film magnetic head of the invention the thin-film magnetic head element
portions may each comprise a magnetoresistive element and the conductors may be
connected to the magnetoresistive element.
The thin-film magnetic head of the invention may further comprise intermediate
connecting portions, provided for the respective thin-film magnetic head element
portions and connected to the element portions, to which the conductors are selectively connected.
A method of manufacturing a thin-film magnetic head of the invention includes
the
steps of: forming a plurality of thin-film magnetic head element portions in a
section to be a main body wherein a thin-film magnetic head element is to be formed
in a substrate, the section having a first surface and a second surface facing
directions opposed to each other, the element portions each having a main part
of a thin-film magnetic head and including at least one first thin-film magnetic
head element portion whose tip faces the first surface and at least one second
thin-film magnetic head element portion whose tip faces the second surface; forming
a plurality of electrodes, in the section to be the main body, for electrically
connecting any of the element portions to an external device; and forming a plurality
of conductors, in the section to be the main body, for electrically connecting
selected one of the element portions to the electrodes.
According to the method of manufacturing a thin-film magnetic head, selected
one of the element portions is electrically connected to the electrodes through
the conductors. As a result, thin-film magnetic heads of several types of specifications
may be selectively provided.
In the method of the invention the first thin-film magnetic element portion and
the second thin-film magnetic element portion may be placed in symmetrical positions
with respect to a place parallel to the first and second surfaces in the step of
forming the element portions.
In the method of the invention the step of forming the electrodes may be performed
either before or after the step of forming the conductors.
In the method of the invention the thin-film magnetic element portions may each
comprise an induction-type magnetic transducer having first and second magnetic
layers magnetically connected to each other and each made up of at least one layer
and including pole portions parts of which facing a recording medium are opposed
to each other with a recording gap layer in between, and thin-film coil placed
between the first and second magnetic layers. The conductors may be connected to
the thin-film coil. The step of forming the element portions may include the steps
of forming the first magnetic layer, forming the thin-film coil on the first magnetic
layer, and forming the second magnetic layer on the thin-film coil.
In the method of the invention the thin-film magnetic head element portions may
each comprise a magnetoresistive element. The conductors may be connected to the
magnetoresistive element.
The method of the invention may further include, before the step of forming the
conductors, the step of forming intermediate connecting portions for the respective
thin-film magnetic head element portions, connected to the element portions, to
which the conductors are selectively connected. The conductors may be connected
to the intermediate connecting portion corresponding to selected one of the element portions.
In the method of the invention the step of forming the conductors may be performed
simultaneously with the step of forming the thin-film coil or with the step of
forming the second magnetic layer, or may be performed after the step of forming
the second magnetic layer.
A thin-film magnetic head material of the invention comprises a plurality of
thin-film
magnetic head element portions formed in a section to be a main body wherein a
thin-film magnetic head element is to be formed in a substrate, the section having
a first surface and a second surface facing directions opposed to each other, the
element portions each having a main part of a thin-film magnetic head and including
at least one first thin-film magnetic head element portion whose tip faces the
first surface and at least one second thin-film magnetic head element portion whose
tip faces the second surface, the element portions being selectively connected
through a plurality of conductors to a plurality of electrodes providing electrical
connection to an external device.
According to the thin-film magnetic head material, selected one of the
element portions is electrically connected to the electrodes through the conductors,
using the material. As a result, thin-film magnetic heads of several types of specifications
may be selectively manufactured.
In the thin-film magnetic head material of the invention the first thin-film
magnetic
element portion and the second thin-film magnetic element portion may be placed
in symmetrical positions with respect to a place parallel to the first and second surfaces.
The thin-film magnetic head material may further comprise the electrodes.
In the thin-film magnetic head material the thin-film magnetic element portions
may each comprise at least part of an induction-type magnetic transducer having
first and second magnetic layers magnetically connected to each other and each
made up of at least one layer and including pole portions parts of which facing
a recording medium are opposed to each other with a recording gap layer in between,
and thin-film coil placed between the first and second magnetic layers.
In the thin-film magnetic head material the thin-film magnetic head element portions
may each comprise a magnetoresistive element.
The thin-film magnetic head material may further comprise intermediate connecting
portions, provided for the respective thin-film magnetic head element portions
and connected to the element portions, to which the conductors are selectively connected.
A method of manufacturing a thin-film magnetic head material of the invention
includes
the step of forming a plurality of thin-film magnetic head element portions in
a section to be a main body wherein a thin-film magnetic head element is to be
formed in a substrate, the section having a first surface and a second surface
facing directions opposed to each other, the element portions each having a main
part of a thin-film magnetic head and including at least one first thin-film magnetic
head element portion whose tip faces the first surface and at least one second
thin-film magnetic head element portion whose tip faces the second surface and
the element portions being selectively connected through a plurality of conductors
to a plurality of electrodes providing electrical connection to an external device.
According to the method of manufacturing a thin-film magnetic head material,
a material comprising a plurality of element portions may be manufactured. Selected
one of the element portions is electrically connected to the electrodes through
the conductors, using the material. As a result, thin-film magnetic heads of several
types of specifications may be selectively manufactured.
In the method the first thin-film magnetic element portion and the second thin-film
magnetic element portion may be placed in symmetrical positions with respect to
a place parallel to the first and second surfaces in the step of forming the element portions.
The method may further include the step of forming the electrodes.
In the method the thin-film magnetic element portions may each comprise at least
part of an induction-type magnetic transducer having first and second magnetic
layers magnetically connected to each other and each made up of at least one layer
and including pole portions parts of which facing a recording medium are opposed
to each other with a recording gap layer in between, and thin-film coil placed
between the first and second magnetic layers.
In the method the thin-film magnetic head element portions may each comprise a
magnetoresistive element.
The method may further include the step of forming intermediate connecting portions
for the respective thin-film magnetic head element portions, the connecting portions
being connected to the element portions, the conductors being selectively connected
to the connecting portions.
Other and further objects, features and advantages of the invention will appear
more fully from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A and FIG. 1B are cross sections for illustrating a step in a method
of manufacturing the main part of a composite thin-film magnetic head common to
embodiments of the invention.
FIG. 2A and FIG. 2B are cross sections for illustrating a step that follows
FIG. 1A and FIG. 1B.
FIG. 3A and FIG. 3B are cross sections for illustrating a step that follows
FIG. 2A and FIG. 2B.
FIG. 4A and FIG. 4B are cross sections for illustrating a step that follows
FIG. 3A and FIG. 3B.
FIG. 5A and FIG. 5B are cross sections for illustrating a step that follows
FIG. 4A and FIG. 4B.
FIG. 6A and FIG. 6B are cross sections for illustrating a step that follows
FIG. 5A and FIG. 5B.
FIG. 7 is a schematic front view of the surface of the up type of the center
element type slider of a first embodiment of the invention in which thin-film magnetic
head element portions are formed.
FIG. 8 is a schematic front view of the surface of the down type of the center
element type slider of the first embodiment in which thin-film magnetic head element
portions are formed.
FIG. 9 is a schematic bottom view of the air bearing surface of the slider of
the first embodiment.
FIG. 10 is a top view of the head element portions wherein the step of forming
the conductors are performed simultaneously with the steps of forming thin-film
coils in the first embodiment.
FIG. 11 is a cross section taken along line 11—11 of FIG. 10.
FIG. 12 is a cross section taken along line 12—12 of FIG. 10.
FIG. 13 is a top view of the head element portions wherein the step of forming
the conductors are performed simultaneously with the step of forming the top pole
layer in the first embodiment.
FIG. 14 is a cross section taken along line 14—14 of FIG. 13.
FIG. 15 is a cross section taken along line 15—15 of FIG. 13.
FIG. 16 is a schematic front view of the surface of the up type of the side
element type slider of a second embodiment of the invention in which thin-film
magnetic head element portions are formed.
FIG. 17 is a schematic front view of the surface of the down type of the side
element type slider of the second embodiment in which thin-film magnetic head element
portions are formed.
FIG. 18 is a schematic bottom view of the air bearing surface of the slider
of the second embodiment.
FIG. 19 is a schematic front view of the surface of the slider of a third embodiment
in which thin-film magnetic head element portions are formed.
FIG. 20 is a schematic bottom view of the air bearing surface of the slider
of the third embodiment.
FIG. 21 is a schematic front view of the surface of the up type of the center
element type slider of a fourth embodiment of the invention in which thin-film
magnetic head element portions are formed.
FIG. 22 is a schematic front view of the surface of the down type of the center
element type slider of the fourth embodiment in which thin-film magnetic head element
portions are formed.
FIG. 23 is a schematic front view of the surface of the up type of the side
element type slider of the fourth embodiment in which thin-film magnetic head element
portions are formed.
FIG. 24 is a schematic front view of the surface of the down type of the side
element type slider of the fourth embodiment in which thin-film magnetic head element
portions are formed.
FIG. 25 is a schematic bottom view of the air bearing surface of the slider
of the fourth embodiment.
FIG. 26 is a schematic front view of the surface of the slider of a fifth embodiment
in which thin-film magnetic head element portions are formed.
FIG. 27 is a schematic bottom view of the air bearing surface of the slider
of the fifth embodiment.
FIG. 28 is a schematic front view of the surface of the slider of a sixth embodiment
in which thin-film magnetic head element portions are formed.
FIG. 29 is a schematic front view of the surface of the up type of the center
element type slider of the sixth embodiment in which thin-film magnetic head element
portions are formed.
FIG. 30 is a schematic front view of the surface of the down type of the center
element type slider of the sixth embodiment in which thin-film magnetic head element
portions are formed.
FIG. 31 is a schematic front view of the surface of the up type of the side
element type slider of the sixth embodiment in which thin-film magnetic head element
portions are formed.
FIG. 32 is a schematic front view of the surface of the down type of the side
element type slider of the sixth embodiment in which thin-film magnetic head element
portions are formed.
FIG. 33 is a cross section for describing a method of forming the conductors
and electrodes of the sixth embodiment.
FIG. 34 is a schematic front view of the surface of the slider of a seventh
embodiment in which thin-film magnetic head element portions are formed.
FIG. 35 is a schematic front view of the surface of the side element type slider
of related art in which thin-film magnetic head element portions are formed.
FIG. 36 is a schematic bottom view of the air bearing surface of the side element
type slider of related art.
FIG. 37 is a schematic front view of the surface of the center element type
slider of related art in which thin-film magnetic head element portions are formed.
FIG. 38 is a schematic bottom view of the air bearing surface of the center
element type slider of related art.
FIG. 39 is an explanatory view for illustrating the arrangement of the thin-film
magnetic heads in the hard disk drive in which a plurality of platters are used.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the invention will now be described in detail
with reference to the accompanying drawings. The following embodiments are examples
wherein the invention is applied to composite thin-film magnetic heads.
Reference is now made to FIG.
1A and FIG. 1B to FIG.
6A and
FIG. 6B for describing a method of manufacturing the main part of a composite thin-film
magnetic head that is common to the embodiments. FIG. 1A to FIG. 6A are cross sections
each orthogonal to an air bearing surface. FIG. 1B to FIG. 6B are cross sections
of a pole portion each parallel to the air bearing surface. The configuration and
the manufacturing method that will be described with reference to the drawings
are those of an example of the thin-film magnetic head of the invention.
In the method of manufacturing the thin-film magnetic head, as shown in FIG.
1A
and FIG. 1B, an insulating layer
2 made of alumina (Al
2O
3),
for example, of about 5 to 10 μm in thickness is deposited on a substrate
1 made of aluminum oxide and titanium carbide (Al
2O
8—TiC),
for example. Next, a bottom shield layer
3 made of a magnetic material for
a reproducing head is formed on the insulating layer
2.
Next, as shown in FIG.
2A and FIG. 2B, on the bottom shield layer
3
alumina of 100 to 200 nm in thickness, for example, is deposited through sputtering
to form a bottom shield gap film
4 as an insulating layer. On the bottom
shield gap film
4 an MR film of tens of nanometers in thickness for making
up an MR element
5 for reproducing is formed. The MR film is then etched
by ion milling, for example, with a photoresist pattern as a mask to form the MR
element
5. The MR element
5 may be either a GMR element or an AMR
element. Next, an electrode layer
6 to be electrically connected to the
MR element
5 is formed on the bottom shield gap film
4 through the
lift-off method, for example. Next, a top shield gap film
7 as an insulating
layer is formed on the bottom shield gap film
4, the MR element
5,
and the electrode layer
6. The MR element
5 is then buried in the
shield gap films
4 and
7. Next, on the top shield gap film
7
a top shield layer-cum-bottom pole (called top shield layer in the following description)
8 made of a magnetic material, of about 3 μm in thickness is formed.
The top shield layer
8 is used for both reproducing head and recording head.
Next, as shown in FIG.
3A and FIG. 3B, a recording gap layer
9
made of an insulating film of alumina, for example, having a thickness of about
200 nm is formed on the top shield layer
8. A contact hole is then formed
in the backward portion (the right-side region of FIG. 3A) by partially etching
the recording gap layer
9 for forming a magnetic path. Next, on the recording
gap layer
9 in the pole portion, a pole tip
10 of 0.5 to 1 μm
in thickness is formed. The pole tip
10 is made of a magnetic material for
a recording head such as FeN or Permalloy (NiFe) that exhibits a high saturation
flux density and forms part of the top pole. At the same time, a magnetic layer
20 made of a magnetic material for forming the magnetic path is formed on
the contact hole for forming the magnetic path.
Next, as shown in FIG.
4A and FIG. 4B, the recording gap layer
9
and the top shield layer (bottom pole)
8 are etched by ion milling with
the pole tip
10 as a mask. As shown in FIG. 4B, the sidewalls of the top
pole (the pole tip
10), the recording gap layer
9 and part of the
top shield layer (bottom pole)
8 are vertically formed in a self-aligned
manner. Such a structure is called trim structure. The trim structure suppresses
an increase in the effective track width due to expansion of the magnetic flux
generated during writing in the narrow track.
Next, an insulating layer
11 of alumina, for example, of about 3 μm
in thickness is formed over the entire surface. The insulating layer
11
is then ground to the surfaces of the pole tip
10 and the magnetic layer
20 and flattened through mechanical polishing or chemical mechanical polishing
(CMP). The surfaces of the pole tip
10 and the magnetic layer
20
are exposed through the flattening.
Next, as shown in FIG.
5A and FIG. 5B, on the flattened insulating layer
11, a thin-film coil
12 of a first layer made of copper (Cu), for
example, for an induction recording head is formed through plating, for example.
Next, a photoresist layer
13 of a specific pattern is formed on the insulating
layer
11 and the coil
12. Heat treatment at a temperature of 250
to 300° C., for example, is performed to flatten the surface of the photoresist
layer
13. Next, on the photoresist layer
13, a thin-film coil
14
of a second layer, made of copper, for example, is formed through plating, for
example. Next, a photoresist layer
15 of a specific pattern is formed on
the photoresist layer
13 and the coil
14. Heat treatment at a temperature
of 250 to 300° C., for example, is performed to flatten the surface of the
photoresist layer
15.
Next, as shown in FIG.
6A and FIG. 6B, a top pole layer
16 made
of a magnetic material for a recording head such as Permalloy is formed on the
pole tip
10, the photoresist layers
13 and
15, and the magnetic
layer
20. An overcoat layer
17 of alumina, for example, is formed
over the top pole layer
16. Finally, mechanical processing of the slider
is performed and the air bearing surface of the recording head and the reproducing
head is formed. The composite thin-film magnetic head is thus completed.
Reference is now made to FIG. 7 to FIG. 9 for describing a thin-film magnetic
head and a method of manufacturing the same, and a thin-film magnetic head material
and a method of manufacturing the same of a first embodiment of the invention.
According to the embodiment, two thin-film magnetic head element portions are formed
in one slider, that is, a portion to be a main body of a thin-film magnetic head
on a substrate. The two thin-film magnetic head element portions include a portion
having the main part of an up-type thin-film magnetic head element for the center
element type, and a portion having the main part of a down-type thin-film magnetic
head element for the center element type. Selection between the up type of the
center element type and the down type of the center element type is allowed by
changing the pattern of conductors between the thin-film magnetic head element
portions and electrodes.
FIG.
7 and FIG. 8 are schematic front views of the surface of the slider
of the embodiment in which the thin-film magnetic head element portions are formed.
FIG. 7 illustrates the up type of the center element type. FIG. 8 illustrates the
down type of the center element type. FIG. 9 is a schematic bottom view of the
air bearing surface of the slider of the embodiment. In FIG. 9 the arrow indicated
with numeral
50 shows the direction of air flow. ‘LE’ indicates
the air inflow end. ‘TR’ indicates the air outflow end.
As shown in FIG. 7 to FIG. 9, the thin-film magnetic head of the embodiment comprises
a slider
25 that flies over the surface of a recording medium (hard disk
platter). The slider
25 corresponds to a main body of the invention. The
slider
25 includes a first surface
25A and a second surface
25B
facing the directions opposite to each other. Either the first surface
25A
or the second surface
25B is to be the air bearing surface (medium facing surface).
In the slider
25 two thin-film magnetic head element portions
31U
and
31D are formed near an end face
30 orthogonal to the direction
of air flow. The one thin-film magnetic head element portion
31U is provided
for the up type of the center element type. The head element portion
31U
is formed in the middle of the slider in the direction orthogonal to the direction
of air flow so that the tip thereof faces the first surface
25A. The other
thin-film magnetic head element portion
31D is provided for the down type
of the center element type. The head element portion
31D is formed in the
middle of the slider in the direction orthogonal to the direction of air flow so
that the tip thereof faces the second surface
25B. The two head element
portions
31U and
31D are each placed in symmetrical positions with
respect to a plane parallel to the first surface
25A and the second surface
25B.
On the end face
30 four pad-shaped electrodes
33 are provided for
electrically connecting the head element portions
31U and
31D to
an external device. The electrodes
33 are electrically connected to either
the head element portion
31U or
31D through four conductors
34.
As shown in FIG. 7, if the head element portion
31U is connected to the
electrodes
33 through the conductors
34, the up-type thin film magnetic
head for the center element type is obtained. As shown in FIG. 8, if the head element
portion
31D is connected to the electrodes
33 through the conductors
34, the down-type thin film magnetic head for the center element type is obtained.
As shown in FIG. 9, a rail
35 is formed in the air bearing surface of
the
slider
25. FIG. 9 illustrates the up-type thin film magnetic head for the
center element type wherein the head element portion
31U is used. In this
case the first surface
25A functions as the air bearing surface. The second
surface
25B functions as the air bearing surface for the down-type thin
film magnetic head for the center element type wherein the head element portion
31D is used.
An example of the basic configuration of the head element portions
31U
and
31D is shown in FIG.
6A and FIG.
6B. The head element
portions
31U and
31D each include the MR element
5 for reading
and the induction magnetic transducer for writing. The induction magnetic transducer
includes the first and second magnetic layers and the thin-film coils
12
and
14 placed between the first and second magnetic layers. The first and
second magnetic layers are each made up of at least one layer, and magnetically
connected to each other. The first and second magnetic layers each include pole
portions. The parts of the pole portions facing the recording medium are opposed
to each other with the recording gap layer
9 in between. In the embodiment
the top shield layer (bottom pole)
8 corresponds to the first magnetic layer.
The pole tip
10, the top pole layer
16 and the magnetic layer
20
correspond to the second magnetic layer.
Two of the four conductors
34 shown in FIG. 7 or FIG. 8 are connected
to the thin-film coils
12 and
14. The remaining two are connected
to the MR element
5 through the electrode layer
6.
In the embodiment the steps of forming the conductors
34 may be performed
simultaneously with the steps of forming the thin-film coils
12 and
14
or with the step of forming the top pole layer
16 as the second magnetic layer.
Reference is now made to FIG. 10 to FIG. 12 for describing a method of
forming the conductors
34 and the electrodes
33 wherein the step
of forming the conductors
34 are performed simultaneously with the steps
of forming the thin-film coils
12 and
14. FIG. 10 is a top view of
the head element portions
31U and
31D. FIG. 11 is a cross section
taken along line
11—
11 of FIG.
10. FIG. 12 is a cross
section taken along line
12—
12 of FIG.
10.
According to the method, the head element portions
31U and
31D
are manufactured through one kind of steps until the step prior to the steps of
forming the thin-film coils
12 and
14. Contact holes or via holes
36 are each formed for providing connection to the electrode layer
6
near the element portions
31U and
31D, respectively, in the top shield
gap film
7 (not shown in FIG.
10). In the steps of forming the thin-film
coils
12 and
14, the four conductors
34 of the material same
as the thin-film coils
12 and
14 are formed by plating, for example,
on the top shield gap film
7. Two of the four conductors
34 are connected
to the thin-film coils
12 and
14 of the element portion to be used.
The remaining two of the four conductors
34 are each connected to the electrode
layer
6 of the element portion to be used through the contact hole
36
formed in the top shield gap film
7, and further connected to the MR element
5 of the element portion to be used through the electrode layer
6.
The pole tip
10, the top pole layer
16 and the magnetic layer
20
as the second magnetic layer are then formed.
In the steps of forming the thin-film coils
12 and
14 and the steps
of forming the second magnetic layer, the thin-film coils
12 and
14
and the second magnetic layer of the head element portion
31U or
31D
which is to be used may be only formed.
Next, before forming the overcoat layer
17, the columnar electrodes
(bumps)
33 made of copper, for example, are formed by plating, for example.
The electrodes
33 are formed such that the lower ends thereof are connected
