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.
A magnetic head of a first embodiment is shown in
In the first embodiment, the magnetic head 20 is a GMT type magnetic head, and its basic structure is the same as that of the conventional magnetic head shown in
A write-head 18 includes a lower magnetic pole 9 and a coil 19 for writing data. The coil 19 is connected to terminals 15a and 15b via cable wires 14a and 14b.
As shown in
The first embodiment is characterized in that the lower shield 7 is extended in the height direction and the width direction so as to cover a resistance area (a planar area), in which the resistance 10 is formed, with a shield pattern 7a.
The resistance 10 has a prescribed resistance value and made of a metallic material, e.g., tantalum, by sputtering. A resist pattern is formed on the substrate 4 so as to form the meandered resistance, then the metallic material, e.g., tantalum, is sputtered so as to form the meandered resistance 10 having the prescribed resistance value. The lower shield 7, the upper shield 8 and the lower magnetic pole 9 are grounded to the substrate 4 via the resistance 10, so that the read-element 5 can be protected from static electricity.
As shown in
The lower shield 7 is made of a magnetic material, e.g., NiFe, and formed by electrolytic plating. When the lower shield 7 is pattern-formed, the lower shield 7 having the shield pattern 7a is formed so as to integrate the shield pattern 7a with the lower shield 7. In other words, the lower shield 7 having the shield pattern 7a which acts as an electromagnetic wave shielding layer is formed. Of course, the entire lower shield 7 including the shield pattern 7a shields external electromagnetic waves.
The magnetic head of a second embodiment is shown in
The second embodiment is characterized in that the upper shield 8 is extended in the height direction and the width direction so as to cover the resistance area, in which the resistance 10 is formed, with a shield pattern 8a, which acts as an electromagnetic waves shielding layer.
The resistance 10 is formed between the lower shield 7 and the upper shield 8, and the resistance 10 in the height direction is meandered in an upper part of the area. The lower shield 7, the upper shield 8 and the lower magnetic pole 9 are electrically connected and grounded to the substrate 4 via the resistance 10, so that the read-element 5 can be protected from static electricity.
Since the upper shield 8 has the shield pattern 8a which covers over the resistance area including the resistance 10, external electromagnetic waves working to the magnetic head 20 can be shielded by the shield pattern 8a. Therefore, noises in the resistance 10, which are generated by the external electromagnetic waves, can be prevented, and the read-element 5 can be protected from the external electromagnetic waves.
The upper shield 8 is a magnetic film made of, for example, NiFe and has a prescribed thickness. The upper shield 8 may be formed by, for example, electrolytic plating. The shield pattern 8a may be simultaneously patterned in a process of forming the upper shield 8.
The magnetic head of a third embodiment is shown in
The third embodiment is characterized in that the lower shield 7 and the upper shield 8 are extended in the height direction and the width direction so as to cover the resistance area, in which the resistance 10 is formed, with both of the shield pattern 7a and the shield pattern 8a.
The resistance 10 is formed between the lower shield 7 and the upper shield 8 in the layering direction, and the resistance 10 is meandered, as well as the second embodiment.
In the third embodiment, the resistance 10 sandwiched between the shield pattern 7a of the lower shield 7 and the shield pattern 8a of the upper shield 8. With this structure, external electromagnetic waves working to the magnetic head 20 can be shielded on the both sides of the resistance 10, so that resistance property of the magnetic head of the third embodiment can be improved more than those of the former embodiments.
The shield patterns 7a and 8a may be simultaneously formed, by electrolytic plating, etc., in processes of forming the lower shield 7 and the upper shield 8. Therefore, the conventional processes for forming the lower shield 7 and the upper shield 8 can be used without changing steps.
The magnetic head of a fourth embodiment is shown in
The fourth embodiment is characterized in that the shield pattern 7a is formed in the lower shield 7 as well as the first embodiment. In the first embodiment, the resistance 10 is formed between the substrate 4 and the lower shield 7 in the layering direction. On the other hand, in the third embodiment, the resistance 10 is formed between the lower shield 7 and the upper shield 8.
Since the resistance 10 is formed in a process of forming films on the substrate 4, the resistance 10 may be formed between the substrate 4 and the lower shield 7 or between the lower shield 7 and the upper shield 8.
In the present embodiment too, the shield pattern 7a of the lower shield 7 covers over the resistance 10. Therefore, the resistance 10 can be shielded from external electromagnetic waves working to the magnetic head 20, generating noises in the resistance 10 can be prevented and deterioration of the read-element 5 can be prevented.
The magnetic head of a fifth embodiment is shown in
The fifth embodiment is characterized in that an electromagnetic wave shielding layer 16, which is separately formed from the lower shield 7, is formed on the lower side of the lower shield 7 (located close to the air bearing surface “B”).
Structures of the read-head and the write-head are the same as those of the former embodiments. As shown in
The electromagnetic wave shielding layer 16 is formed between the resistance 10 and the lower shield 7, in the layering direction, on the substrate 4. Since the electromagnetic wave shielding layer 16 is separately formed from the lower shield 7, the electromagnetic wave shielding layer 16 may be extended beyond the resistance 10 until reaching the air bearing surface “B”. In
A material of the electromagnetic wave shielding layer 16 is not limited to a magnetic material. It may be made of any materials, which are capable of shielding electromagnetic waves. The electromagnetic wave shielding layer 16 may be formed on the substrate 4 by a film forming process, e.g., plating, sputtering.
In the magnetic head 20 of the present embodiment, the electromagnetic wave shielding layer 16 covers over at least the resistance area, in which the resistance 10 is formed. With this structure, external electromagnetic waves working to the resistance 10 can be shielded, and deterioration of characteristics of the read-element 5, which is caused by the external electromagnetic waves, can be prevented.
By covering the broad area, in which the read-head is formed and the resistance 10 is included, with the electromagnetic wave shielding layer 16, the entire magnetic head 20 can be shielded from external electromagnetic waves.
The magnetic head of a sixth embodiment is shown in
The sixth embodiment is characterized in that the electromagnetic wave shielding layer 16 is formed under the lower shield 7 as well as the fifth embodiment. In the fifth embodiment, the electromagnetic wave shielding layer 16 is formed between the resistance 10 and the lower shield 7 in the layering direction; in the sixth embodiment, the electromagnetic wave shielding layer 16 is formed between the substrate 4 and the resistance 10.
The electromagnetic wave shielding layer 16 covers over the resistance area, in which the resistance 10 is formed, and is extended near the air bearing surface “B”, as well as the fifth embodiment.
In the present embodiment too, the resistance 10 is shielded from external electromagnetic waves by the electromagnetic wave shielding layer 16, so that the read-element 5 can be protected from the external electromagnetic waves.
The magnetic head of a seventh embodiment is shown in
The seventh embodiment is characterized in that the electromagnetic wave shielding layer 16 is formed between the upper shield 8 and the lower magnetic pole 9 as shown in
As shown in
The magnetic head of an eighth embodiment is shown in
The eighth embodiment is characterized in that the electromagnetic wave shielding layer 16 is formed above a write-head in the layering direction as shown in
As shown in
With this structure, the electromagnetic wave shielding layer 16 is capable of shielding and protecting not only the resistance 10 but also the read-head and the write-head of the magnetic head 20 from external electromagnetic waves.
The magnetic head of a ninth embodiment is shown in
The ninth embodiment is characterized in that the electromagnetic wave shielding layers 16a and 16b are respectively formed between the substrate 4 and the lower shield 7 and between the upper shield 8 and the lower magnetic pole 9 in the layering direction. Namely, the electromagnetic wave shielding layers 16 of the sixth embodiment and the seventh embodiment are combined. The resistance 10 against static electricity is formed as well as the eighth embodiment.
In the present embodiment, the resistance 10 is sandwiched between the electromagnetic wave shielding layers 16a and 16b. In comparison with the magnetic head having the single shielding layer 16, the function of shielding the resistance 10 and the read-head from external electromagnetic waves can be further improved.
The magnetic head of a tenth embodiment is shown in
The tenth embodiment is characterized in that the electromagnetic wave shielding layers 16a and 16c are respectively formed between the substrate 4 and the lower shield 7 and above the write-head. Namely, the electromagnetic wave shielding layers 16 of the sixth embodiment and the eighth embodiment are combined. The resistance 10 against static electricity is formed as well as the ninth embodiment.
In the present embodiment, the read-head and the write-head of the magnetic head 20 are sandwiched between the electromagnetic wave shielding layers 16a and 16c in the resistance area, in which the resistance 10 is formed. In comparison with the magnetic head having the single shielding layer 16, the function of shielding the resistance 10, the read-head and the write-head from external electromagnetic waves can be further improved.
Note that, in the above described embodiments, the magnetic heads have the GMR type read-elements, but the type of the read-element is not limited. For example, the shield patterns and the electromagnetic wave shielding layers may be similarly applied to magnetic heads having TMR type read-elements so as to improve resistance properties of the magnetic heads against electromagnetic waves.
In the above described embodiments, the upper shield 8 of the read-head and the lower magnetic pole 9 of the write-head are separately formed, but the present invention may be applied to a magnetic head, in which the upper shield 8 works as not only the upper shield but also the lower magnetic pole. The magnetic head of the above described embodiments are horizontal magnetic recording heads, but the type of the write-head is not limited. The present invention may be applied to vertical magnetic recording heads as well. Further, an entire structure of the magnetic head is not limited to the above described embodiments.
The magnetic head 20 of each of the embodiments is formed by forming the films on the substrate 4, etching the films, etc., and the magnetic head 20 is assembled in a head slider 30 shown in
A magnetic disk drive unit, in which the head slider 30 is attached, is shown in
The head slider 30 is elastically pressed onto the surface of the magnetic disk 53 by the head suspension 55. Therefore, the head slider 30 contacts the surface of the magnetic disk 53 while stopping the rotation of the magnetic disk 53. When the magnetic recording disk 53 is rotated by the spindle motor 52, the head slider 30 is floated from the surface of the magnetic recording disk 53 by the air stream generated by rotation of the magnetic recording disk 53. Then, an actuator 56 performs a seeking action, so that the carriage arm 54 is turned to move to prescribed positions and the magnetic head 20 is capable of recording data in and reproducing data from the magnetic recording disk 53.
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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2006-176983 | Jun 2006 | JP | national |