JP3790224B2 - Magnetic head - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic head used for recording / reproducing data on / from a magnetic recording medium. The term “magnetic head” as used in this specification means a data recording / reproducing head having a magnetic field generating coil, and includes a magneto-optical head. Further, the “magnetic recording medium” in the present specification means a recording medium capable of recording and / or reproducing data by using magnetic means. Therefore, it is a wide concept including a data recording medium using magnetic means having any shape in addition to a magnetic disk and a magneto-optical disk.
[0002]
[Prior art]
Data recording on the magnetic recording medium is performed by controlling the direction of the magnetic flux of the recording magnetic field generated by the coil provided in the magnetic head. The magnetic field for recording is abruptly and continuously reversed in the direction of the magnetic flux when a high frequency current is passed through the coil. The magnetic recording medium preferably has a magnetic field for recording as effective as possible. As a means for that purpose, there is a means for providing a magnetic film having a high magnetic permeability in a magnetic head (for example, see Patent Document 1). .)
[0003]
Conventionally, as an example of a magnetic head for recording / reproducing such data, there is a configuration as shown in FIG. 11, for example. The magnetic head H ′ includes a slider 80, an objective lens 81 mounted on the slider 80, a coil 82, and a magnetic film 83. The coil 82 is for generating a magnetic field for recording, is formed by two spiral conductor films 82a and 82b, and is covered with a dielectric layer 86 from the viewpoint of insulation protection. The inner peripheral end portions of the two conductor films 82 a and 82 b are connected to each other via the connection portion 84. Lead wire portions 85a and 85b extending in the radial direction of the coil 82 are connected to the outer peripheral end portions of the conductor films 82a and 82b. By connecting the wiring members 86a and 86b to the conductor films 82a and 82b, external conductors for the coil 82 are connected. The power supply from can be performed. The magnetic film 83 is made of a material having high magnetic permeability, and is disposed below the coil 82. According to such a configuration, the recording magnetic field generated by the coil 82 is suppressed from leaking below the magnetic film 83, and the magnetic field can be effectively applied toward the magneto-optical disk D. it can.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2003-511144
[Problems to be solved by the invention]
However, the conventional means has the following problems.
[0006]
When writing data to the magneto-optical disk D by the magnetic field modulation method, the direction of the magnetic flux of the magnetic field is switched by passing a high-frequency current through the coil 82. As shown in FIG. 12, the power supply device 88 including a pair of output terminals 88a and 88b for supplying power to the coil 82 needs to have a function of switching the direction of the high-frequency current sharply and continuously. . For this reason, the power supply device 88 becomes complicated, which may increase the cost and reduce the reliability of the device. In addition, in response to a request for a higher-speed writing process, the switching speed of the current by the power supply device 88 may not be sufficient.
[0007]
As a means for solving such a problem, it is conceivable to employ a coil having a structure shown in FIG. The coil 91 shown in the figure is composed of two conductor films 91a and 91b. One end portions of these conductor films 91a and 91b are connected to a terminal 93, and the terminal 93 is connected to a negative terminal of a power supply device (not shown). The other end portions 94 and 95 of the conductor films 91a and 91b are respectively connected to the positive terminal of the power supply device. When energization is performed on the end 94 side, an upward magnetic field is generated at the center of the conductor film 91a. On the other hand, when energization is performed on the end portion 95 side, a downward magnetic field is generated in the central portion of the coil 91b. If the coil having such a structure is used, the direction of the magnetic field generated by the coil can be reversed without changing the direction of the current supplied from the power supply device. That is, the power supply device does not need to have a function of generating a high-frequency current, and can perform high-speed inversion with a constant current direction. In addition, the configuration of the power supply device can be simplified.
[0008]
However, the coil 91 having the structure shown in FIG. 13 has three lead-out wiring portions, whereas the conventional magnetic head H ′ has two lead-out wiring portions 85a and 85b. Many. Therefore, if the structure shown in FIG. 13 is used as it is, a space for providing an increased lead-out wiring portion is required, and the thickness of the magnetic head increases accordingly. Accordingly, when the thickness of the dielectric layer 86 increases, the stress due to the formation increases, and this stress acts on the slider 80. Since the slider 80 is made of, for example, glass, there is a possibility that problems such as the slider 80 being warped or cracked due to the stress. In the conventional magnetic head H ′, there is almost no margin in the strength of the slider 80 against the stress due to the formation of the dielectric layer 86, and it is difficult to increase the thickness of the dielectric layer 86.
[0009]
The present invention has been conceived under the circumstances described above, and an object thereof is to enable high-speed data writing while suppressing an increase in the thickness of the magnetic head.
[0010]
DISCLOSURE OF THE INVENTION
In order to solve the above problems, the present invention takes the following technical means.
[0011]
The magneto-optical head provided by the present invention includes a magnetic field generating coil disposed opposite to a magnetic recording medium, a plurality of lead-out wiring portions for energizing the coil, and the magnetic member sandwiching the coil. the recording medium a magnetic head and a, a magnetic film provided on the opposite side, at least one of said plurality of lead-out wiring portion, notch portion formed in the upper Symbol magnetic film In the in-plane direction of the magnetic film .
[0012]
According to the above configuration, at least one of the plurality of lead-out wiring portions connected to the coil has a structure provided using a space for providing the magnetic film, and the thickness of the entire magnetic head is increased. It is possible to suppress this. Therefore, for example, in order to increase the reversal speed of the coil, even when the number of lead-out wiring portions is increased, an increase in the thickness of the magnetic head is suppressed, and the magnetic head is warped or cracked. It is possible to suppress problems such as end.
[0013]
In a preferred embodiment of the present invention, the coil has a structure in which two spiral conductor films having different winding directions are laminated and inner peripheral ends of the two conductor films are connected to each other. The plurality of lead-out wiring portions include a pair of first lead-out wiring portions whose one ends are connected to the respective outer peripheral ends of the two conductor films and one ends connected to the respective inner peripheral end portions of the two conductor films. And a second lead-out wiring portion.
[0014]
According to the above configuration, for example, the pair of first lead-out wiring portions are connected to the positive terminal of the power supply device, the second lead-out wiring portion is connected to the negative terminal of the power supply device, and the power supply device is provided. Using the switching function thus provided, it is possible to reverse the direction of the recording magnetic field and to perform writing in the magnetic field modulation method by energizing one of the pair of first lead-out wiring portions. Therefore, since it is not necessary to use a power supply device that can generate a high-frequency current, the power supply device can have a simple configuration as compared with the conventional case. Further, according to the above-described switching, it is possible to increase the speed of data writing.
[0015]
In a preferred embodiment of the present invention, a portion of the second lead-out wiring portion, a cutout portion formed in the upper Symbol magnetic layer is configured to have passed in the plane direction of the magnetic film In addition, each of the first lead-out wiring portions is formed in the same layer as the two conductor films. Such a configuration is suitable in terms of reducing the thickness of the magnetic head.
[0016]
In a preferred embodiment of the present invention, when the same voltage is applied to the two conductor films of the coil, the magnetic field intensity of the two conductor films is the same in the magnetic recording medium. Of the two conductor films, one located on the side far from the magnetic recording medium has a larger number of turns than the other.
[0017]
According to the above configuration, even when the conductor films have different distances from the magnetic recording medium on which data is written, when the same voltage is applied, the magnetic field generated by them in the recording layer of the magnetic recording medium It is possible to equalize the strength. Therefore, the power supply device does not need to be adjustable in voltage, and can have a simple structure. In addition, it is possible to prevent a decrease in the reliability of the writing process.
[0018]
Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be specifically described with reference to the drawings.
[0020]
1 to 3 show a reference example of magnetic head.
[0021]
First, an example of the configuration of a magnetic information processing apparatus using a magnetic head as a reference example will be described with reference to FIG. The magnetic information processing apparatus P shown in FIG. 1 is configured as a magneto-optical disk apparatus including a magnetic head H, a carriage 6, a fixed optical unit 7, and a power supply device 8. The configuration of the magnetic information processing apparatus P and the role of the magnetic head H in the magnetic information processing apparatus P are the same in the case of the magnetic head according to the present invention described later.
[0022]
The magneto-optical disk D is supported by the spindle Sp and can be rotated at high speed around the spindle Sp by the driving force of the spindle motor M. A recording layer 40 is provided on the opposite surface of the magneto-optical disk D to the side facing the magnetic head H. The surface of the recording layer 40 is covered with an insulating protective film 41 having translucency.
[0023]
The carriage 6 is disposed below the magneto-optical disk D and is movable in the radial direction of the magneto-optical disk D by a driving force of a voice coil motor (not shown), for example. By the movement of the carriage 6, a seek operation for placing the magneto-optical head H in the vicinity of the target track is performed. The fixed optical unit 7 includes a laser diode, a collimator lens, and the like (both not shown), and the laser light L emitted from the fixed optical unit 7 travels toward the carriage 6 and is mounted on the carriage 6. It is configured to reach the rising mirror 13. The fixed optical unit 7 is also provided with a beam splitter and a photodetector (both not shown).
[0024]
The actuator 9 is for performing focus control and tracking control during recording and reproduction on the magneto-optical disk D. The actuator 9 is mounted on the carriage 6 and enables the lens holder 10 on which the objective lens 5b is mounted to move in the vertical direction and the magneto-optical disk D in the radial direction.
[0025]
As clearly shown in FIG. 2, the magnetic head H is configured as a magneto-optical head including a slider 1, an objective lens 5 a mounted on the slider 1, a coil 2, and a magnetic film 3. ing. The slider 1 is supported by a suspension 12 that can be bent and deformed in the vertical direction, and is disposed to face the magneto-optical disk D. The slider 1 floats with a small gap between the slider 1 and the magneto-optical disk D due to a so-called wedge effect caused by an air flow flowing between the slider 1 and the magneto-optical disk D. is there. The slider 1 is made of, for example, glass made of the same material as that of the objective lens 5a, and a light-transmitting dielectric layer 4 is formed on the surface thereof.
[0026]
The objective lens 5a is for focusing the laser beam L transmitted through the objective lens 5b and forming a laser spot on the recording target portion of the recording layer 40 of the magneto-optical disk D.
[0027]
The coil 2 is embedded in the vicinity of the surface layer of the dielectric layer 4 and includes a first conductor film 20a and a second conductor film 20b. The first and second conductor films 20a and 20b are both spiral coils, and the winding directions are different from each other. The first and second conductor films 20a and 20b are formed so as not to block the laser light L transmitted through the objective lens 5a, and have the optical axis A of the objective lens 5a as the center.
[0028]
A connection portion 24 made of a conductor is provided between the first and second conductor films 20a and 20b. The inner peripheral end 21 a of the first conductor film 20 a and the inner peripheral end 21 b of the second conductor film 20 b are conductively connected to each other through this connection portion 24. A pair of first lead wiring portions 25a and 25b extending in the radial direction of the coil 2 are connected to the outer peripheral ends 22a and 22b of the first and second conductor films 20a and 20b, respectively. A second lead wiring portion 25c is connected to the inner peripheral end portion 21b of the second conductor film 20b. A part of the second lead-out wiring portion 25 c is formed by the magnetic film 3, and is connected to the magnetic film 3 and a wiring portion 25 c ₁ that connects the end 21 b and the magnetic film 3. And a wiring portion 25c ₂ extending in the radial direction of the magneto-optical disk D. These first and second lead-out wiring portions 25 a to 25 c are portions for energizing the first and second conductor films 20 a and 20 b and extend to the outside of the dielectric layer 4. Each of the one end portions is exposed to the outside on one side surface of the dielectric layer 4 or one side surface of the slider 1. The exposed portions are connected to wiring members 26a to 26c made of a metal film such as copper, which are electrically connected to the first and second lead wiring portions 25a to 25c. The coil members are connected to the exposed portions through the wiring members 26a to 26c. 2 can be supplied with power from the power supply device 8.
[0029]
The magnetic film 3 is disposed below the coil 2 and suppresses the leakage of the recording magnetic field generated by the coil 2 so that the magnetic field acts efficiently on the magneto-optical disk D. It is. The magnetic film 3 is made of a material having a high magnetic permeability such as permalloy, and has a ring shape centered on the optical axis A so as not to block the laser light L.
[0030]
The first and second conductor films 20a and 20b, the first and second lead wiring portions 25a to 25c, the magnetic film 3 and the like constituting the coil 2 can be manufactured by a process similar to the semiconductor manufacturing process. Is possible. The first and second conductor films 20a and 20b and the first and second lead wiring portions 25a to 25c are formed by patterning a metal film such as copper into a predetermined shape. A thin dielectric layer is formed so as to cover the two conductor films 20a and 20b. Similarly, the magnetic film 3 is also formed by patterning a film such as permalloy, and a thin dielectric layer is formed so as to cover the magnetic film 3. By repeating such steps, a dielectric layer 4 having a laminated structure is formed on the surface of the slider 1, and the first and second conductor films 20a and 20b, the first and second lead layers are formed therein. A structure in which the wiring portions 25a to 25c and the magnetic film 3 are embedded is obtained.
[0031]
As clearly shown in FIG. 3, the power supply device 8 is for supplying power to the coil 2, and includes a pair of positive terminals 8 a and 8 b and a negative terminal 8 c. The pair of first lead-out wiring portions 25a and 25b are connected to the pair of positive terminals 8a and 8b via the wiring members 26a and 26b, and the second lead-out wiring portion 25c is connected to the negative terminal 8c. Connected to. The power supply device 8 has a switching function, and can be switched to one of the positive terminals 8a and 8b to be energized. When the terminal 8a is energized by the switching, as shown in FIG. 3A, power is supplied to the first conductor film 20a through the first lead-out wiring portion 25a and the second lead-out wiring portion 25c. A supply circuit is formed. At this time, a recording magnetic field 40 in a downward direction is generated at the center of the first conductor film 20a formed as a spiral coil. On the other hand, when energized from the terminal 8b by the switching, as shown in FIG. 3B, the second conductor film 20b is connected to the second conductor film 20b via the first lead-out wiring portion 25b and the second lead-out wiring portion 25c. A circuit for supplying power is formed. Since the winding directions of the first and second conductor films are opposite to each other, the direction of the recording magnetic field 40 generated by the second magnetic film is opposite to the direction of the magnetic field generated by the first magnetic film. And upwards.
[0032]
Next, the operation of the magnetic head H will be described.
[0033]
When writing data to the magneto-optical disk D by the magnetic field modulation method, first, the magneto-optical disk D is rotated to float the slider 1 from the magneto-optical disk D at a minute interval. Then, the temperature of the recording layer 40 is raised by continuously irradiating the recording target portion of the recording layer 40 with the laser light L. On the other hand, the direction of the recording magnetic field generated by the coil 2 is switched according to the content of the recording data. Thereby, the direction of magnetization of the magnetic material constituting the recording layer 40 is controlled. At this time, the direction of the magnetic field for recording by the coil 2 is switched by the switching function provided in the power supply device 8 so that the current from the power supply device 8 is either the first conductor film 20a or the second body film 20b. This is done by energizing appropriately. Therefore, data can be written by a magnetic field modulation method using a power supply device having a simple structure, and an increase in cost and a decrease in reliability of the device can be suppressed. Furthermore, in comparison with the power supply device having the function of generating a high-frequency current used in the prior art, the reversal of the current by switching provided in the power supply device 8 can be speeded up, and the data writing speed is high. Can be achieved.
[0034]
In addition, a part of the second lead-out wiring portion 25 c provided to enable the adoption of the power supply device 8 that exhibits the above-described effect is formed using the magnetic film 3. Therefore, no new space is required to provide the second lead-out wiring portion 25c, and for example, the dielectric layer 4 is not thickened to provide the second lead-out wiring portion 25c. Therefore, the thickness of the magnetic head H can be made the same as that of the magnetic head according to the prior art, and the occurrence of problems such as the magnetic head H being warped or broken can be prevented.
[0035]
Figures 4-8 show an implementation form of the magnetic head according to the present invention. In these figures, the Reference Example and the same or similar elements are denoted by the reference example and the same reference numerals.
[0036]
In the embodiment shown in FIGS. 4 to 7, the second lead-out wiring portion 25 c is configured to pass through the notch formed in the magnetic film 3.
[0037]
More specifically, in the configuration shown in FIG. 4, the second lead-out wiring portion 25 c connected to the inner peripheral end portion 21 b of the conductor film 20 b is not connected to the magnetic film 3 and the magnetic film 3 And extends outside the dielectric layer 4. As clearly shown in FIG. 5, a part of the magnetic film 3 is divided to form a cutout portion 3a, and the second lead-out wiring portion 25c passes through the cutout portion 3a. is doing. According to such a configuration, the current supplied to the coil 2 does not flow through the magnetic film 3. Therefore, in addition to the effects described above, an effect of preventing an overcurrent loss in the magnetic film 3 is also obtained. Even when the magnetic film 3 is formed of a material having a high resistivity, energy loss due to heat generation or the like. And the power supply to the coil 2 can be performed efficiently.
[0038]
6 and 7, the magnetic film 3 has a structure in which a notch 3b having a depth of about half the thickness is formed. The second lead-out wiring portion 25c passes through the cutout portion 3b. Even with such a configuration, the same effect as described above can be obtained.
[0039]
In the embodiment shown in FIG. 8, the number of turns of the second conductor film 20b on the side far from the magneto-optical disk D is larger than the number of turns of the first conductor film 20a on the side near the magneto-optical disk D. Yes. In the data writing, either the first conductor film 20a or the second conductor film 20b is used independently depending on the direction of the recording magnetic field to be generated. Unlike the present embodiment, when the number of turns of each of the first and second conductor films 20a and 20b is the same, assuming that the voltages applied to them are the same, the recording on the magneto-optical disk D is performed. Due to the difference in the distance to the layer 40, the recording magnetic field strengths of the first and second conductor films 20a and 20b in the recording layer 40 are different. Such a difference in the strength of the recording magnetic field may cause an error in data writing. On the other hand, according to this embodiment, since the number of turns of the second conductor film 20b disposed at a position far from the magneto-optical disk D is larger than that of the first conductor film 20a, both When the same voltage is applied to the recording layer 40, the strength of the recording magnetic field in the recording layer 40 can be made equal. Therefore, it is possible to prevent a decrease in the reliability of the writing process. In addition, the configuration of the power supply device can be further simplified.
[0041]
In the reference example shown in FIG. 9, the coil 2 is formed of one conductor film 20a. The second lead-out wiring portion 25 c connected to the inner peripheral end portion 21 a of the conductor film 20 a is formed using a part of the magnetic film 3. In this configuration, as shown in FIG. 10, the recording magnetic field is controlled by supplying a high-frequency current to the coil 2 as in the prior art, and has a function of generating a high-frequency current. A power supply device 8 ′ is used .
[0042]
【The invention's effect】
As can be understood from the above description, according to the present invention, it is possible to increase the speed of data writing while suppressing an increase in the thickness of the magnetic head.
[Brief description of the drawings]
1 is a schematic explanatory view showing an example of a magnetic information processing device using a reference example of magnetic head.
Figure 2 is a fragmentary cross-sectional view showing a reference example of magnetic head.
FIG. 3 is an explanatory diagram of generation of a magnetic field by a coil and a power supply device.
Is a fragmentary cross-sectional view showing an embodiment of a magnetic head according to Figure 4 the present invention.
5 is a cross-sectional view of a principal part taken along line VV in FIG. 4. FIG.
FIG. 6 is a cross-sectional view of a main part showing another embodiment of a magnetic head according to the present invention.
7 is a cross-sectional view of a main part along the line VII-VII in FIG. 6;
FIG. 8 is a cross-sectional view of a main part showing another embodiment of a magnetic head according to the present invention.
9 is a fragmentary cross-sectional view showing another reference example of magnetic head.
FIG. 10 is an explanatory diagram of generation of a magnetic field by a coil and a power supply device.
FIG. 11 is an explanatory diagram of a conventional technique.
FIG. 12 is an explanatory diagram of magnetic field generation by a coil and a power supply device.
FIG. 13 is an explanatory diagram of a structure of a magnetism generating coil.
[Explanation of symbols]
H Magnetic head 1 Slider 2 Coil 3 Magnetic films 3a and 3b Notch 4 Dielectric layers 5a and 5b Objective lens 8 Power supply device 20a First conductor film 21b Second conductor films 25a and 25b First lead-out wiring section 25c 2nd lead-out wiring part

Claims (4)

A magnetic field generating coil disposed to face the magnetic recording medium;
A plurality of lead wiring portions for energizing the coil;
A magnetic film provided on the opposite side of the magnetic recording medium across the coil;
A magnetic head comprising:
At least one of said plurality of lead-out wiring portion is characterized in that a cutout portion formed in the upper Symbol magnetic layer is configured to have passed in the plane direction of the magnetic film, the magnetic head . The coil has a configuration in which two spiral conductor films having different winding directions are laminated, and inner peripheral ends of the two conductor films are connected to each other.
As for the plurality of lead-out wiring sections, one end is connected to a pair of first lead-out wiring sections whose one ends are connected to the respective outer peripheral ends of the two conductor films, and one inner end of each of the two conductor films. The magnetic head according to claim 1, further comprising a second lead wiring portion. Part of the second lead-out wiring portion, a cutout portion formed in the upper Symbol magnetic film with has a configuration that has passed through the in-plane direction of the magnetic film, each of the first lead-out wiring The magnetic head according to claim 2, wherein the portion is formed in the same layer as the two conductor films. Of the two conductor films of the coil, the magnetic recording medium is such that when the same voltage is applied to the two conductor films of the coil, the magnetic field strength of the two conductor films is the same in the magnetic recording medium. 4. The magnetic head according to claim 2, wherein the number of turns on one side farther from the second side is larger than that on the other side.

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