The present invention relates to a method of manufacturing a magnetic head, more precisely relates to a method of manufacturing a magnetic head having a write-head, in which a plurality of write-coils are layered.
An example of a conventional magnetic head of a magnetic disk drive unit is shown in
In some cases, the coils 14 are formed as a single-layer. In the case shown in
A conventional method of manufacturing the magnetic head, in which the coils 14 are layered, will be explained with reference to
In
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In
Conventionally, when the coils 14 are layered in the write-head of the magnetic head, unnecessary parts of the insulating layer 24 are removed by ion milling. To perfectly remove the insulating layer 24 from the surfaces of the tip magnetic pole section 12a and the connecting sections 14c and 15a, the surfaces of the tip magnetic pole section 12a and the connecting sections 14c and 15a are slightly grooved by ion milling. Parts A shown in
Conventionally, the tip magnetic pole section 12a is large, and a pattern of the coil 14 is wide. Therefore, the unnecessary parts of the insulating layer 24 can be easily removed by ion milling. However, recent magnetic heads are very small, and components parts of write-heads must be minute. So, it is very difficult to uniformly and precisely remove the unnecessary parts of the insulating layer 24 from an entire wafer by ion milling. Since amounts of grooving the tip magnetic pole section 12a and the connecting sections 14c and 15a are varied, thickness of the resist coating them must be varied, so that accuracy of patterning the resist must be lowered.
The present invention was conceived to solve the above described problems.
An object of the present invention is to provide a method of manufacturing a magnetic head, which is capable of securely insulating coils in different layers when the magnetic head including a write-head constituted by a plurality of the layered coils is formed and which is capable of easily and securely manufacturing the magnetic head with securely removing unnecessary parts of an insulating layer when a magnetic pole is formed.
To achieve the object of the present invention, the present invention has following constitutions.
Namely, the method of manufacturing a magnetic head, which includes a lower magnetic pole, an upper magnetic pole and a write-head, which is sandwiched between the magnetic poles and constituted by a plurality of layered coils, comprises the steps of: forming a tip magnetic pole section, which is located at a front end of the lower magnetic pole, and the coil of the first layer on a surface of a substrate; polishing the entire surface of the substrate so as to make the entire surface of the substrate, which includes a surface of the tip magnetic pole section and a surface of the coil of the first layer, even flat face; coating the surface of the substrate other than specific parts, which electrically insulate the coil of the first layer from the coil of a second layer, with resist; coating the entire surface of the substrate, on which the resist has been applied, with an insulating layer; removing the insulating layer from the specific parts together with the resist by liftoff; and forming the coil of the second layer on the insulating layer formed on the substrate.
The method may further comprise the step of forming a tip magnetic pole section of an upper layer, which is electrically connected to the tip magnetic pole section. By coating the surface of the tip magnetic pole section with the resist, coating the surface of the substrate with the insulating layer and lifting off the insulating layer, the insulating layer is removed from the surface of the tip magnetic pole section. Further, the surfaces of the tip magnetic pole section and the coil of the first layer are included in the same plane, so that the coil, etc. of the second layer can be precisely formed.
In the method, a connecting section, which connects the lower magnetic pole with the upper magnetic pole, may be formed when the tip magnetic pole section is formed in the surface of the substrate, and the entire surface of the substrate, which includes the surface of the tip magnetic pole section, the surface of the coil of the first layer and a surface of the connecting section, may be polished and formed into the even flat face. In this case, the insulating layer can be securely removed from the surface of the connecting section when the magnetic head is manufactured.
The method may further comprise the steps of: polishing the entire surface of the substrate, which includes the surface of the coil of the second layer, so as to make the entire surface even flat face; coating the surface of the substrate other than specific parts, which electrically insulate the coil of the second layer from a coil of a third layer, with resist; coating the entire surface of the substrate, on which the resist has been applied, with another insulating layer; removing the insulating layer from the specific parts together with the resist by liftoff; and forming the coil of the third layer on the insulating layer formed on the substrate. With this method, in case of forming the coils of three layers or more, the coils can be mutually securely insulated and precisely formed.
By employing the method of the present invention, the insulating layer, which insulates the coil of the first layer from the coil of the second layer, can be securely formed between the layers. Further, in the lifting off step, the entire surface of the substrate is polished after forming the coil of the first layer and the tip magnetic pole section. The tip magnetic pole section, whose surface has been made flat, can be processed in the following step in the state, in which the surfaces of the tip magnetic pole section and the coil are included in the same horizontal plane. Therefore, component parts of the magnetic head can be precisely formed, and a minute magnetic head can be precisely formed.
Embodiments of the present invention will now be described by way of examples and with reference to the accompanying drawings, in which:
Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
In
To form the coil 14a, photosensitive resist, whose thickness is thicker than that of the coil 14a, is coated on a surface of the insulating layer 20, the resist is patterned by photolithographic method so as to form a part of the coil 14a, which will be an electrically conductive part, into a groove, and the groove part is filled with copper by plating. After forming the coil 14a, the resist pattern is removed, and a spiral space in the coil 14a is filled with resist 22.
A tip magnetic pole section 12a and a connecting section 15a are formed by plating a surface of the lower magnetic pole 12 with a magnetic material.
After forming the coil 14a, the tip magnetic pole section 12a and the connecting section 15a, an entire surface of the wafer is coated with alumina by sputtering, the surface of the wafer is polished by CMP (Chemical Mechanical Polishing) method, so that surfaces of the tip magnetic pole section 12a, the coil 14a, the connecting section 15a and the resist 22 are included in the same plane. In
In the present embodiment, the step shown in
To coat the specific parts with the resist 30, firstly the entire surface of the wafer is coated with resist, then the wafer is optically exposed and developed so as to leave the resist 30 in the specific parts. Since many elements are arranged in the wafer, patterns of the tip magnetic pole sections 12a and the connecting sections 15a and 14c are correctly positioned and exposed so that the resist patterns 30 can be correctly formed.
The resist 30 is optically exposed and developed in a state shown in
Next, the entire surface of the wafer, in which the resist patterns 30 have been formed, is coated with the insulating layer 24, which is an inorganic insulating film made of, for example, alumina or SiO2, by sputtering. In
Then, the insulating layer 24 in the specific parts, in which the resist patterns 30 exist under the insulating layer 24, is removed, together with the resist 30, by liftoff. Namely, the resist 30 coating the surface of the wafer is removed. At that time, the insulating layer 24 adhering to the resist 30 is removed together with the resist 30.
In
The process of removing the insulating layer 24 from the specific parts by liftoff is capable of securely removing the insulating layer 24 from the specific parts, e.g., the tip magnetic pole sections 12a, the connecting sections 15a and 14c, in which no insulating layer must be left. By removing the insulating layer 24, the surfaces, which have been polished together with the coil 14a, can be exposed.
By exposing the polished surfaces of the tip magnetic pole section 12a and the connecting sections 15a and 14c as they are, their exposed surfaces can be included in the same plane. Therefore, a magnetic layer can be precisely formed on the surfaces of the tip magnetic pole section 12a and the connecting sections 15a and 14c, so that the tip magnetic pole section and the connecting sections can be finally precisely formed with prescribed thickness.
After the liftoff step, a part of the insulating layer 24, which corresponds to the coil 14a of the first layer, is left. Further, step-shaped parts of the insulating layer 24 are formed between the specific parts, which correspond to the tip magnetic pole section 12a and the connecting sections 15a and 14c, and the part corresponding to the coil 14a. Forming the step-shaped parts are previously estimated in a designing stage, so they are not formed by variations of the process. When resist is applied to the wafer so as to form a resist pattern for the coil 14b of the second layer, the resist can be patterned with high accuracy so that the coil 14b, etc. of the second layer can be precisely formed.
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Since the surfaces of the tip magnetic pole section 12a and the connecting section 15a of the first layer are not coated with the insulating layer 24, the tip magnetic pole section 12b and the connecting section 15b of the second layer can be electrically connected to the tip magnetic pole section 12a and the connecting section 15a of the first layer.
In the above described embodiment, when the coil 14a, the tip magnetic pole section 12a and the connecting section 15a of the first layer are formed on the wafer, the surface of the wafer is polished and flattened. The insulating layer 24 is formed on the highly flattened surface. Further, the coil 14b, etc. of the second layer can be formed on the highly flattened insulating layer 24. Therefore, even if the magnetic head is minute, the coils, the tip magnetic pole sections, etc. can be precisely formed with securing electric conductivity.
Note that, in the above described embodiment, the coils are formed as two layers. The present invention is not limited to the embodiment. For example, the coils may be formed as three layers or more. For example, after forming the coil 14b of the second layer, the surface of the wafer is flattened. Then, a part corresponding to the coil of a third layer is coated with an insulating layer by the liftoff process, and the insulating layer is removed from the specific parts. Namely, the components of the third layer can be formed as well as the components of the second layer.
The invention may be embodied in other specific forms without departing from the spirit of essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Number | Date | Country | Kind |
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2006-40162 | Feb 2006 | JP | national |