JPH1116125A - Magnetic head unit, its manufacturing method and magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively shield the bias signals in a UHF band. SOLUTION: At least the side surfaces of a head slider and a microstrip line unit 74 are covered by electrically conductive thin films 64, 65 and 84. A reproduced signal ground side electrode terminal 59 and a high frequency bias supplying ground side electrode terminal 60 are arranged between high frequency bias supplying electrode terminals 58. Moreover, the lines of the unit 74 corresponding to the respective electrode terminals are arranged in a similar manner to the terminals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active magnetic head unit using a high-frequency signal, a method of manufacturing the same, and a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art As a magnetic head for a hard disk (HDD), a ferrite head MIG head,
Inductive heads such as thin film heads have been put to practical use. In recent years, a magnetoresistive (MR) head has been put to practical use as a reproducing head.

FIG. 16 shows the structure of a composite head in which a recording inductive head and a reproducing MR head are integrated. For a similar head, see the Japan Society of Applied Magnetics, Vol. 15, No. 2,141-144
(1991). FIG. 17 is an enlarged view of only the MR detection unit.

A reproducing MR head has an MR film 3 in a gap 8 between a ferrite substrate 1 and a magnetic yoke 4 of a recording head.
The hard magnetic film 2 is formed to make the magnetic domains of the MR and MR into a single magnetic domain structure.

On the other hand, the recording head forms a recording gap 6 constituted by magnetic yokes 4 and 5. Here, by passing a signal current through the winding 7 of the recording head, a signal magnetic field is generated in the recording gap 6, and the magnetic layer 10 formed on the magnetic recording medium substrate 11 relatively moving with the composite magnetic head. , A signal magnetization 9 is formed.

At the time of reproduction, since the electric resistance of the MR film 3 changed by the magnetic flux of the signal magnetization 9 changes, the current flowing through the lead thin film 12 to the MR film 3 changes, and this change is detected. It is said that a sensitivity about 3 to 10 times that of the reproduction by the inductive head can be obtained.
In recent years, the development of giant MR has been promoted, and it is predicted that there is a possibility that the MR head has a reproduction sensitivity 3 to 10 times that of the MR head.

FIG. 18 is a technical report of IEICE MR95.
No.-85, an element and a head using a change in magnetic impedance have been proposed (MI head). FIG. 18 shows the operating principle of a magneto-impedance element in which a lead 15 made of a conductive metal thin film is sandwiched by a soft magnetic core 25 and 26 made of a laminated film of a permalloy film 22 and a SiO ₂ film 21 over a track width 16. . A high-frequency signal is applied from a high-frequency transmitter 13 in the UHF band via a resistor 14 to pass a current 17, and a voltage between the terminals 19 and 20 disposed at both ends of the lead 15 is determined based on a change in magnetic impedance between the terminals. A change is detected. When there is no signal magnetic field generated from the magnetization 23 on the magnetic recording medium 24, the current 17 and the terminal 1 of the lead 15 are connected between the terminals 19 and 20.
UHF equivalent to the product of the impedance between 9 and 20
When a bias signal voltage is generated and receives a signal magnetic field from the magnetic recording medium 24, the soft magnetic cores 25, 2
Since the easy magnetization direction of the magnetization of No. 6 is oriented in the track width direction, the magnetization is inclined from the orientation direction by the signal magnetic field, and the magnetic impedance is reduced. Therefore, UHF
The bias signal is A due to the signal magnetic field of the magnetic recording medium 24.
It is detected in an M-modulated form. This signal is A
The signal magnetization 23 on the magnetic recording medium 24 can be read out by M detection.

When this head is realized, it is expected that there is a possibility that an output about 10 times higher than that of an MR head or a giant MR head which is currently under development is obtained. In addition, since a high-frequency signal is used as a bias signal, its wavelength is such that the size of the object to be handled cannot be ignored, and the transmission line for adding the high-frequency signal and the transmission line for extracting the signal are treated as distributed constants. It has been reported that it is necessary to use an impedance matching line so that reflected waves do not occur in order to prevent loss. FIG. 19 shows a head suspension 86 usually used for an HDD, which is made of metal such as stainless steel. On the head suspension 86, a head gimbal, a head slider 89 to which the head is attached, a screw hole 87 for attaching to the rotating arm, and a folded portion 88 for increasing the strength and attaching a lead wire from the head are formed. ing. FIG. 20 shows FIG.
A cross section taken along the line cd of the head suspension surrounded by a circle is formed by bending the head suspension upward from the plane portion 90 of the head suspension. However, at present, there is a limit to thinning the coaxial wire used as a lead wire, and there is a limit to signal loss and impedance matching, and the rigidity is high. This has been an obstacle to securing the flying height between the head and the medium and reducing the load.

[0009]

As described above, the realization of an MI head is desired. However, these transmission lines are similar to an antenna when transmitting a high-frequency signal, and generate radio wave radiation, There is a problem in that a sufficient signal-to-noise ratio (SNR) cannot be obtained by inducing noise from the outside. Therefore, it is required to realize the configuration in consideration of the shield.

In the HDD, a head suspension provided with a magnetic head needs to seek a signal area at high speed. Therefore, it is extremely important how to manufacture and arrange a transmission line having a configuration that does not hinder the movement of the head suspension moving at high speed.

The present invention has been made in consideration of the above-described problems of the related art, and a magnetic head unit capable of effectively shielding a bias signal in the UHF band, a method of manufacturing the magnetic head unit, and a magnetic recording using the magnetic head unit. It is an object to provide a playback device.

[0012]

According to a first aspect of the present invention, there is provided a magnetic head unit including a head slider having a magnetic thin film element, wherein the magnetic thin film element includes a magnetic thin film element. A core, a conductive thin film sandwiched between the magnetic cores, and one or more electrodes disposed at both ends of the conductive thin film; and an electrode terminal of the electrode of the magnetic thin film element is provided with an electrode terminal of the head slider. A magnetic head unit which is exposed on a caps surface, and wherein at least one side surface of the head slider is coated with a conductive thin film.

According to a second aspect of the present invention, there is provided a magnetic head unit including a head slider having a magnetic thin film element, wherein the magnetic thin film element includes a magnetic core, a conductive thin film sandwiched between the magnetic cores, Two or more pairs of electrodes disposed at both ends of the conductive thin film, and the electrode terminals of the electrodes of the magnetic thin film element are exposed on the caps surface of the head slider; Is a reproduction signal electrode, and between the non-ground electrode terminal of the reproduction signal electrode and the non-ground electrode terminal of all the other pairs of electrodes, The magnetic head unit is arranged so that there is at least one of the ground-side electrode terminals of the pair of electrodes.

According to a third aspect of the present invention, the ground-side electrode terminals of all the pairs of electrodes are not the ground-side electrode terminals of the reproduction signal electrodes, and the ground terminals of all the other pairs of electrodes are grounded. The magnetic head unit according to claim 2, wherein the magnetic head unit is arranged between the side electrode terminal and the other terminal.

According to a fourth aspect of the present invention, in the magnetic head unit according to any one of the first to third aspects, a high-frequency oscillator for applying a high-frequency voltage to the conductive thin film is provided in a part of the head slider. is there.

According to a fifth aspect of the present invention, there are provided at least two pairs of the electrodes, and a pair of bias supply microstrip lines connecting the high frequency oscillator and one of the electrodes is formed on the caps surface. 5. The method according to claim 4, wherein
2. The magnetic head unit according to item 1.

According to a sixth aspect of the present invention, there is provided a microstrip line unit having a reproduction signal microstrip line pair for transmitting a reproduction signal of the magnetic thin film element, wherein the reproduction signal microstrip line pair is a conductor thin film. 6. The magnetic head unit according to claim 4, wherein a quarter wavelength matching transmission line is formed including the following.

According to a seventh aspect of the present invention, there is provided a reproduction signal microstrip line pair for transmitting a reproduction signal of the magnetic thin film element, and a bias for applying a high frequency voltage to the conductor thin film from a high frequency oscillator provided outside. A microstrip line unit having a supply microstrip line pair, wherein the reproduction signal microstrip line pair includes a quarter-wavelength matched transmission line including the conductor thin film. A magnetic head unit according to claim 1.

According to the present invention, there is provided a strip-shaped substrate having a ground surface formed of a conductive thin film on one surface thereof, and a dielectric formed on a surface of the ground surface opposite to the substrate side. And one or more pairs of microstrip lines formed on a surface of the dielectric opposite to the ground plane side, wherein the ground side line of the microstrip line pair penetrates through the dielectric to form the ground plane. And a microstrip line unit connected to the magnetic head unit.

According to a ninth aspect of the present invention, the plurality of microstrip line pairs are plural, one of the plurality of pairs of microstrip lines is a reproduction signal microstrip line pair, and the reproduction signal microstrip line is provided. At least one of the ground lines of all microstrip line pairs is between the non-ground line of the line pair and the non-ground line of all other microstrip line pairs. The magnetic head unit according to claim 8, wherein the magnetic head unit is arranged as follows.

According to a tenth aspect of the present invention, the ground line of all the microstrip line pairs is a line other than the ground line of the reproduction signal microstrip line pair and the other pair of microstrip line pairs. The magnetic head unit according to claim 9, wherein the magnetic head unit is disposed between the line and the other line that is not the ground side line.

[0022] In the eleventh aspect of the present invention, at least a side surface of the microstrip line unit is coated with a conductive thin film.
A magnetic head unit according to any one of the above.

According to a twelfth aspect of the present invention, a rectangular parallelepiped substrate having a rectangular back surface having a shorter side having the same length as the length of the head slider of the magnetic head unit to be manufactured, and having a thickness greater than the thickness of the head slider, is provided. A groove having a depth equal to or greater than the thickness of the head slider is polished from the back surface side, and a space obtained by adding the width of the groove to the width of the head slider parallel to the short side of the rectangle from the back surface side. Formed, out of all the surfaces formed on the rectangular parallelepiped substrate, at least, perpendicular to the back surface, parallel to the rectangular short side or on all surfaces including the rectangular short side, conductive After the thin film is formed, each head slider is separated by polishing from the sliding surface side opposite to the back surface until the thickness of the rectangular parallelepiped substrate becomes the same as the thickness of the head slider. Forming a magnetic head unit manufacturing method characterized by.

According to a thirteenth aspect of the present invention, a conductive thin film serving as a ground plane is formed on one surface of a strip-shaped substrate, and a dielectric is formed on the conductive thin film. A pair of microstrip line pairs is formed so that a ground side line thereof penetrates through the dielectric and is connected to the ground plane, and is at least perpendicular to one surface of the substrate and is connected to the microstrip line pair. A method for manufacturing a magnetic head unit, wherein a microstrip line unit is manufactured by applying a conductive thin film on parallel side surfaces.

The present invention of claim 14 is the invention of claim 8 or 1
1. A magnetic recording / reproducing apparatus comprising: the magnetic head unit according to claim 1, wherein a magnetic recording medium is configured to be grounded, wherein a line other than a ground side line of the microstrip line pair is connected to the ground plane and the magnetic field. A magnetic recording / reproducing apparatus is provided between the recording medium and the recording medium.

According to a fifteenth aspect of the present invention, there is provided a magnetic recording / reproducing apparatus comprising the magnetic head unit according to the ninth to eleventh aspects, wherein the magnetic recording medium is grounded. The magnetic recording / reproducing apparatus is characterized in that a line other than the ground side line of the strip line pair is arranged between the ground plane and the magnetic recording medium.

According to a sixteenth aspect of the present invention, there is provided a magnetic recording / reproducing apparatus comprising the magnetic head unit according to any one of the eighth to eleventh aspects, wherein the magnetic recording medium is configured to be grounded. The magnetic recording / reproducing apparatus is characterized in that a projection surface of the slider on the magnetic recording medium surface is included in a projection surface of the ground surface on the magnetic recording medium surface.

[0028]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a schematic configuration diagram showing a magnetic head unit according to Embodiment 1 of the present invention, and FIG. 2 is a schematic sectional view of a head suspension according to Embodiment 1 of the present invention. 3 is a magnetic recording and reproducing apparatus according to the first embodiment of the present invention, FIG. 4 is a configuration diagram of an equivalent circuit of the magnetic recording and reproducing apparatus according to the first embodiment of the present invention, and FIG. 5 is an embodiment of the present invention. FIG. 6 is an exploded perspective view of a magnetic head unit according to Embodiment 1, FIG. 6 is a sectional view of a microstrip line unit according to Embodiment 1 of the present invention, and FIG. 7 is a sectional view of a head slider according to Embodiment 1 of the present invention. It is a thing. 1 and 2 show the internal configuration on the surface to simplify the connection of leads and the like in order to clearly show the schematic configuration. The actual structure of each part is as shown in FIGS.

First, in FIG. 1, a head suspension 27 also serving as a microstrip line unit is
Dielectric 34 which is a strip-shaped silicon substrate having a high relative dielectric constant
A thin film made of copper having good conductivity is formed on one upper surface to form a ground plane 33 of the microstrip line unit. In the actual structure, as shown in FIG. 6, a strip-shaped substrate 76 made of a thin stainless steel plate or the like is formed on the upper surface of the ground plane 33, but is omitted in this drawing for the above-described reason. Further, a signal line 28 of a microstrip line is formed on the opposite surface by using photolithography technology. The cross section is shown in FIG. The head slider 31 is attached to the lower surface of the head suspension 27. Further, a head 29 (hereinafter referred to as an MI head) that corresponds to the magnetic thin film element of the present invention and detects a change in magnetic impedance is formed on one end surface of the head slider 31, and is provided by a magnetic core of the MI head 29. Some of the leads 40 and 30 are sandwiched. The lead 40 is connected to the signal line 28 of the microstrip line, and the lead 30 is connected to the ground plane 33 of the microstrip line unit 27. On the other hand, microstrip line unit 2
7 is provided with an electrode terminal 42 of the signal line 28 and an electrode terminal 41 of the ground plane 33 at one end, and leads these electrode terminals 41 and 42 to an electric circuit for demodulating AM modulation.

The unit length 32 of the microstrip line unit 27 is strictly shorter than the length of 1/4 wavelength since the microstrip line is formed including the lengths of the conductor leads 40 and 30. It is configured as follows. The UHF band high-frequency transmitter 44 is provided on the other end surface of the head slider 31 and is connected to the ground plane 33 and the signal line 28, not shown in the drawing.

With the above configuration, the maximum voltage is output between the electrode terminals 41 and 42, and the output of UHF can be detected. FIG.
Means that the head unit is a hard disk drive (HDD)
1 shows a state in which the camera is mounted on the camera. The ground surface 33 of the head suspension 27 is grounded to the ground 38 of the HDD, and the metal magnetic layer or the disk substrate of the magnetic recording medium 35 is grounded to the ground 39 of the HDD.

With this configuration, the signal line 28 of a microstrip line, which easily radiates radio waves like an antenna and easily induces external noise, is sandwiched between grounds, thereby shielding radio waves and noise. Things. Further, a head suspension 27 as the microstrip line unit is fixed to a rotating arm 36 having high rigidity so that the head position can be moved at a high speed by a rotating shaft 37. Regarding the shielding effect of radio waves and noise from the MI head 29, the microstrip line 2
8, when the leads 40, 30 and the head slider 31 are attached, the surface on which the head slider 31 is projected onto the magnetic recording medium 35 corresponds to the microstrip line unit 2;
It has been experimentally found that the shield effect can be provided by arranging the ground plane 33 of No. 7 so as to be included in the plane projected onto the magnetic recording medium 35.

As shown in FIG. 4, a bias signal is applied from a high-frequency oscillator 44 to an MI head 29 in which a conductive thin film 43 is sandwiched between magnetic cores 47. That is, the high-frequency oscillator 44 is connected to the high-frequency bias supply electrode 48 via the resistor 45. The high-frequency bias supply electrode 48 and the grounded high-frequency bias ground electrode 49 form a pair of electrodes, and are coupled to the conductive thin film 43. On the other hand, of the pair of electrodes 50 and 55 also connected to the conductive thin film 43, the reproduction signal electrode 5
0 is connected to a signal microstrip line 46 (corresponding to 28 in FIG. 1) forming a quarter wavelength matching line, and the other reproduction signal ground electrode 55 is grounded.

In this state, when a signal magnetic field 57 generated from the magnetic recording medium 35 is applied to the MI head 29, the high frequency bias signal is AM-modulated by the strength of the signal magnetic field. This signal is demodulated by an AM demodulation circuit provided on the electrode 56 at the other end of the microstrip line 46. This demodulation circuit is constituted by a combination of capacitors 51 and 53 and a diode 52. The signal demodulated in this manner becomes maximum and can be detected at the terminal 54.

Further, according to the present invention, at least the side surfaces of the head slider 31 on which the MI head 29 is formed and the microslip line unit 27 are covered with a conductive thin film,
This is to further improve the shielding effect. FIG.
The magnetic head unit on which the I head is mounted and whose side surface is shielded is disassembled into a head slider 31 and a microstrip line unit 27. 6 shows a section AA'-B'-B in FIG. 5, and FIG. 7 shows a section aa'-b'-b in FIG. As shown in FIG. 7, the high frequency bias supply electrode 48 and the high frequency bias supply ground electrode 4
9, a reproduction signal electrode 50, and a reproduction signal ground electrode 5
5 is formed. Furthermore, those electrodes 4
8, 49, 50, and 55, a high-frequency bias supply electrode terminal 58, a high-frequency bias supply ground electrode terminal 60, a reproduction signal electrode terminal 61, and a reproduction signal ground electrode terminal 59 are formed in this order. I have. The MI head 29
It is necessary to select the polarity of the lead immediately before coming out from the MI head 29 on one side to the ground side and the other side to the signal side. Since the extended portion of the lead is formed three-dimensionally by using photolithography technology, it can be designed at any position. Each electrode terminal uses photolithography technology and is about 10 μm in the direction perpendicular to the paper.
A conductive film such as copper, silver, or gold is formed on the surface of the substrate. Further, a protective layer (not shown) of alumina is formed on the MI head 29 at a thickness of about 30 μm, and its surface is polished flat. Each terminal is configured to be exposed on the caps surface 69 by polishing. The side surface of the head slider in FIG. 5 is coated with conductive thin films 64 and 65 by plating. At this time, a resist film is formed on a part of the caps surface 69 so that the conductive thin film is not coated. Further, the high-frequency bias supply electrode terminal 5 formed on the caps surface 69 by photolithography technology.
The high frequency bias supply microstrip line 70 including the high frequency bias supply 8 and the high frequency bias supply ground side microstrip line 75 including the high frequency bias supply ground side electrode terminal 60 are connected to the bias supply terminal 62 of the high frequency oscillator 44 and the ground thereof. It is connected to the side terminal 63. In addition,
It is important to adjust the specific resistance, cross-sectional shape, and length of the microstrip line 70 for supplying a high-frequency bias for impedance matching. In this example, since the output impedance of a normal oscillator is 50 ohms, Ta or Cr
The resistance value of the supply line is set to 50 ohms by using the method described above.

As shown in FIG. 6, the microstrip line unit 27 is formed by forming a grounding surface 33 which is a conductive film of copper or the like on a substrate 76 which is a thin stainless steel plate on a strip, and then forming a substrate such as alumina. The dielectric 34 is formed, and a reproduction signal microstrip line 79 and a reproduction signal ground side microstrip line 78 are formed by using photolithography technology. In order to improve the shielding effect, the microstrip line unit 2
A conductive thin film 84 is formed on the side and upper surfaces of 7 by plating. In the present embodiment, copper is used as the conductive thin film 84. The detailed description will be given later with reference to FIG.

The reproduction signal microstrip line 7
9 and the reproduction signal ground side microstrip line 78 are respectively brought into contact with the reproduction signal electrode terminal 61 and the reproduction signal ground side electrode terminal 59 to which solder or gold, aluminum, silver, or the like is welded in advance, and ultrasonic waves are applied. Being welded. The lower surface of the microstrip line unit 27 and the caps surface 69 are joined using lead glass having a low melting point.

Although the substrate 76 is described as a stainless steel plate, a metal plate or a plate polished thinly with silicon, glass, carbon, alumina or the like is also effective.

Although copper is used as the ground plane 33 of the microstrip line 27 and the conductive thin film 84, conductive materials such as gold, silver, and aluminum are also effective.

As the conductive thin films 64 and 65 on the side surfaces of the head slider 31, besides copper, magnetic alloys such as gold, silver, aluminum, permalloy, cobalt-based alloys and nickel alloys having low specific resistance are also effective.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described with reference to FIGS.

FIG. 8 is a configuration diagram of an equivalent circuit of a magnetic recording / reproducing apparatus according to the second embodiment of the present invention, and FIG. 9 is a schematic configuration diagram showing a magnetic head unit according to the second embodiment of the present invention. 10 is a schematic sectional view of a head suspension according to a second embodiment of the present invention, FIG. 11 is an exploded perspective view of a magnetic head unit according to the second embodiment of the present invention, and FIG.
FIG. 13 is a sectional view of the microstrip line unit according to the second embodiment of the present invention, and FIG. 13 is a second embodiment of the present invention.
1 is a cross-sectional view of a head slider according to the first embodiment. 9 and FIG. 10 show the internal cross section on the surface to simplify connection of leads and the like in order to easily show the schematic configuration. The actual structure of each part is shown in FIGS.
As shown in FIG. It shows. Embodiment 1
Similarly, FIG. 12 shows a cross section AA′-B ′ of FIG.
FIG. 13 shows a cross section aa'-b'-b of FIG. 11, respectively.

In the first embodiment of the present invention, the high-frequency oscillator 43 is arranged on the head slider 31. In the second embodiment of the present invention, the high-frequency oscillator 44 is not mounted on the magnetic head unit. It is configured to be mounted on the rotating arm 36 having high rigidity or another part on the magnetic recording / reproducing apparatus, to achieve high-speed movement of the head suspension, to secure a floating amount between the head and the medium, and to reduce the load. is there.

In FIG. 8, two signal lines are arranged in a microstrip line unit 74 also serving as a head suspension. The first signal line 28 is the same as in the first embodiment. The second signal line 71 is connected to the coaxial line 7 via the resistor 45 from the high-frequency signal transmitter 44.
3 applies a high frequency bias to the electrode terminal 72 of the second signal line 71. Since the diameter of the coaxial line 73 is large and the rigidity is extremely high, when the coaxial line 73 is disposed on the head suspension, the operation as the head suspension is considerably adversely affected. However, the configuration as in the second embodiment enables a configuration that does not affect the movement of the head suspension even with a coaxial line having a large rigidity. In addition, as can be seen from FIG. 10, the cross section of the head suspension has a configuration in which two signal lines 28 and 71 are provided.

Further, in the second embodiment, FIGS.
As shown in FIG. 5, at least the side surfaces of the head slider 31 and the microslip line unit 74 in which the MI head is formed are covered with conductive thin films 64, 65, 84,
The shielding effect is further improved. The configuration of the MI head 29 is the same as that of the first embodiment, and the second embodiment is characterized by the configuration of the caps surface 69 of the head slider 31 and the strip line unit.

That is, similarly to the first embodiment, each terminal 58, 59, 60, 61 of the head cap surface 69 is
The microstrip line 81 for supplying the high frequency bias, the ground side microstrip line 78 for the reproduction signal, the ground side microstrip line 80 for the high frequency bias supply, and the reproduction signal microstrip line 79 of the microstrip line unit 74 are welded together, and the caps surface is formed. 69 and the lower surface of the microstrip line unit 74 are joined. Since almost all surfaces of the magnetic head unit are covered with the conductive thin film in this way, in addition to preventing external noise, ground-side terminals of a plurality of pairs of electrodes are arranged between signal terminals, Correspondingly, by arranging the ground side microstrip line between the signal microstrip lines, the leakage signal from the high frequency bias supply microstrip line 81 is reduced to the reproduction signal ground side microstrip line 78 and the high frequency bias supply ground. Microstrip line 79 for the reproduction signal, which is shielded by the side microstrip line 80.
Has an important configuration that makes it difficult to leak. For this reason, it turned out that a shielding effect can be improved remarkably.

Next, a method of manufacturing the head slider according to the first and second embodiments of the present invention will be described with reference to FIG.

FIG. 14 shows a manufacturing process of the head slider of the present invention. First, the unit substrate wafer surface
On (aa′-b′-b), a head bar 83 is formed by forming a large number of arrays of surfaces (thin-film MI magnetic head surfaces) 82 shown in FIG. 7 or FIG. Head slider 31
The back surface (cut surface ad-d'-a ') of the head bar 83, which becomes the caps surface 69, is polished to form a groove 91 between the thin-film MI magnetic head surfaces 82.
A conductive thin film of copper or the like is formed on the entire surface of the groove 91 by plating. Next, the back surface (ad-d'-a ')
Surface) on the carrier with a fixing material such as brazing material,
The sliding surface (beee'-b 'surface) is polished to cc'. Thereafter, the head slider 31 is cut off by removing it from the carrier. In this way, a head slider whose side surface is shielded can be easily manufactured.

FIG. 15 shows a process of manufacturing the microstrip line unit 74 according to the second embodiment of the present invention. FIG. 15A shows a grounded surface 77 which is a conductive thin film of copper or the like on a stainless steel thin plate substrate 76 on a strip.
Is formed, and a dielectric 34 of an alumina film is further formed thereon by sputter deposition. FIG. 15 (B) shows that a hole is formed in the terminal forming portion of the dielectric 34 by ion milling, and copper is formed in the hole by sputtering. A high-frequency bias supply ground side microstrip line 80 is formed. Next, after forming a high-frequency bias supply microstrip line 81 and a reproduction signal microstrip line 79 on the dielectric 34, the microstrip line unit surface 85 from which each microstrip line is exposed is covered with a resist or the like. A conductive thin film 8 such as copper is formed on the entire microstrip line unit 74.
4 is formed. In this manner, the microstrip line unit 74 having an excellent shielding effect as shown in FIG. 12 is obtained.

In the second embodiment, the lines 81 and 7 on the microstrip line unit are used.
8, 80 and 79 need not be in this order;
It suffices that either 78 or 80 is arranged between 1. Although the description has been made on the assumption that the number of the microstrip line pairs is two, three or more pairs may be used. In this case, at least the line which is not the ground-side line of the reproduction signal microstrip line pair and all other microstrip lines Between the line that is not the ground side line of the line pair, at least one of the ground side lines of all the microstrip line pairs is arranged, and the corresponding electrode terminals are arranged similarly. I just need to.

In the first and second embodiments, alumina is used as the dielectric 34.
Inorganic materials such as O2, glass, and GaAs are also effective.

In the first and second embodiments described above, the conductive thin film is formed on the entire surface, the upper surface, and the side surface of the microstrip line unit. However, the conductive thin film is formed on at least both side surfaces parallel to the microstrip line. It is good. Similarly, it has been described that a conductive thin film is formed on the front and side surfaces of the head slider,
What is necessary is just to form on both sides parallel to a microstrip line at least.

[0054]

As is apparent from the above description, the present invention provides a magnetic head unit capable of effectively shielding a bias signal in the UHF band, a method of manufacturing the same, and magnetic recording / reproducing using the magnetic head unit. An apparatus can be provided.

That is, when extracting a signal from the MI head using the matching line, the microstrip line is used as a head suspension, and the signal of the strip line is provided between the ground plane of the microstrip line and the grounded magnetic recording medium surface. By deploying the line, UHF
An object of the present invention is to provide a magnetic head unit capable of effectively shielding a band bias signal between an MI head and a magnetic recording medium, a manufacturing method thereof, and a magnetic recording / reproducing apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a magnetic head unit according to a first embodiment of the present invention;

FIG. 2 is a schematic sectional view of the head suspension according to the first embodiment of the present invention;

FIG. 3 is a magnetic recording / reproducing apparatus according to the first embodiment of the present invention;

FIG. 4 is a configuration diagram of an equivalent circuit of the magnetic recording and reproducing apparatus according to the first embodiment of the present invention;

FIG. 5 is an exploded perspective view of the magnetic head unit according to the first embodiment of the present invention.

FIG. 6 is a sectional view of the microstrip line unit according to the first embodiment of the present invention.

FIG. 7 is a sectional view of the head slider according to the first embodiment of the present invention;

FIG. 8 is a configuration diagram of an equivalent circuit of the magnetic recording / reproducing apparatus according to the second embodiment of the present invention;

FIG. 9 is a schematic configuration diagram showing a magnetic head unit according to a second embodiment of the present invention.

FIG. 10 is a schematic sectional view of a head suspension according to a second embodiment of the present invention.

FIG. 11 is an exploded perspective view of a magnetic head unit according to the second embodiment of the present invention.

FIG. 12 is a sectional view of a microstrip line unit according to a second embodiment of the present invention.

FIG. 13 is a sectional view of a head slider according to the second embodiment of the present invention.

FIG. 14 is a diagram showing a manufacturing process of the head slider of the present invention.

FIG. 15 is a diagram showing a manufacturing process of the microstrip line unit according to the second embodiment of the present invention.

FIG. 16 is a sectional view of a composite head including an MR head and an inductive head.

FIG. 17 is an operation principle diagram of an MR head.

FIG. 18 is an operation principle diagram of an MI head.

FIG. 19 is a configuration diagram of a conventional head suspension.

FIG. 20 is a sectional view of a conventionally used head suspension.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ferrite substrate 2 Hard magnetic film 3 MR film 4 Magnetic yoke 5 Magnetic yoke 6 Recording gap 7 Winding 8 Gap 9 Signal magnetization 10 Magnetic layer 11 Magnetic recording medium substrate 12 Lead thin film 13 High frequency oscillator 14 Resistance 15 Lead 16 Track width 17 High frequency current 18 1/4 matching line 19 terminal 20 terminal 21 SiO ₂ film 22 permalloy 23 signal magnetization 24 magnetic recording medium 25 soft magnetic core 26 soft magnetic core 27 head suspension 28 signal line 29 MI head 30 lead 31 head slider 32 unit length Depth 33 Ground plane 34 Dielectric 35 Magnetic recording medium 36 Rotating arm 37 Rotating shaft 38 HDD ground 39 HDD ground 40 Lead 41 Electrode terminal 42 Electrode terminal 43 Conductive thin film 44 High frequency transmitter 45 Resistance 46 Signal line 4 7 Magnetic core 48 High frequency bias supply electrode 49 High frequency bias supply ground electrode 50 Reproduction signal electrode 51 Capacitor 52 Diode 53 Capacitor 54 Terminal 55 Reproduction signal ground electrode 56 Terminal 57 Signal magnetic field 58 High frequency bias supply electrode terminal 59 Reproduction signal Ground electrode terminal for high frequency 60 Ground electrode terminal for high frequency bias supply 61 Electrode terminal for reproduction signal 62 Terminal for bias supply of high frequency oscillator 63 Ground terminal for bias supply of high frequency oscillator 64 Conductive thin film 65 Conductive thin film 67 Upper magnetic pole 68 Lower magnetic pole 69 Caps surface 70 Microstrip line for supplying high frequency bias 71 Signal line 72 Electrode terminal 73 Coaxial line 74 Microstrip line unit 75 Ground side microstrip line for supplying high frequency bias 6 Substrate 78 Ground-side microstrip line for reproduction signal 79 Microstrip line for reproduction signal 80 Ground-side microstrip line for high-frequency bias supply 81 Microstrip line for high-frequency bias supply 82 Thin-film MI magnetic head surface 83 Head bar 84 Conductive thin film 85 Surface of Microstrip Line Unit 86 Head Suspension 87 Screw Hole 88 Folded Part 89 Head Slider 90 Head Suspension Flat Surface 91 Groove

Claims (16)

[Claims] 1. A magnetic head unit including a head slider having a magnetic thin film element, wherein the magnetic thin film element is disposed at both ends of a magnetic core, a conductive thin film sandwiched by the magnetic core, and both ends of the conductive thin film. One or more pairs of electrodes, the electrode terminals of the electrodes of the magnetic thin film element are exposed on the caps surface of the head slider, and at least one side surface of the head slider is conductive. A magnetic head unit characterized by being coated with a conductive thin film. 2. A magnetic head unit having a head slider having a magnetic thin film element, wherein the magnetic thin film element is disposed at both ends of a magnetic core, a conductive thin film sandwiched by the magnetic core, and both ends of the conductive thin film. Two or more pairs of electrodes are provided, the electrode terminals of the electrodes of the magnetic thin film element are exposed on the caps surface of the head slider, and one of the electrodes is provided with a reproduction signal. Between the non-ground electrode terminal of the reproduction signal electrode and the non-ground electrode terminal of all other pairs of electrodes. A magnetic head unit, wherein at least one of the ground-side electrode terminals is arranged. 3. The ground-side electrode terminal of the pair of electrodes is not the ground-side electrode terminal of the reproduction signal electrode and the ground-side electrode terminal of all the other pairs of electrodes is not the ground-side electrode terminal. The magnetic head unit according to claim 2, wherein the magnetic head unit is arranged between the terminal and the terminal. 4. The magnetic head unit according to claim 1, wherein a high-frequency oscillator for applying a high-frequency voltage to the conductive thin film is provided in a part of the head slider. 5. The method according to claim 1, wherein the number of the electrodes is two or more, and a pair of bias supply microstrip lines connecting the high-frequency oscillator and one of the electrodes is formed on the caps surface. The magnetic head unit according to claim 4. 6. A microstrip line unit having a pair of reproduction signal microstrip lines for transmitting a reproduction signal of the magnetic thin film element, wherein the reproduction signal microstrip line pair includes the conductor thin film.
6. The magnetic head unit according to claim 4, wherein a matching transmission line having a one-half wavelength is formed. 7. A pair of reproduction signal microstrip lines for transmitting a reproduction signal of the magnetic thin film element, and a pair of bias supply microstrip lines for applying a high frequency voltage to the conductor thin film from an externally provided high frequency oscillator. 4. The microstrip line unit for reproducing signals according to claim 1, wherein the pair of reproduction signal microstrip lines includes the conductor thin film to form a quarter wavelength matched transmission line. The magnetic head unit according to any one of the above. 8. A ground plane formed of a conductive thin film on one surface of a strip-shaped substrate, a dielectric formed on a surface of the ground surface opposite to the substrate side, and A microstrip line pair formed on a surface opposite to the ground plane side, wherein a ground side line of the microstrip line pair penetrates the dielectric and is connected to the ground plane; A magnetic head unit comprising a strip line unit. 9. The plurality of microstrip line pairs, one of the plurality of microstrip line pairs being a reproduction signal microstrip line pair, and a ground line of the reproduction signal microstrip line pair. The non-ground line and the non-ground line of all other microstrip line pairs are arranged so that there is at least one of the ground lines of all microstrip line pairs. The magnetic head unit according to claim 8, wherein: 10. The ground-side line of all the microstrip line pairs is not the ground-side line of the reproduction signal microstrip line pair and the ground-side line of the other pair of microstrip line pairs is not. 10. The magnetic head unit according to claim 9, wherein the magnetic head unit is disposed between the magnetic head unit and the line. 11. The magnetic head unit according to claim 6, wherein at least a side surface of the microstrip line unit is coated with a conductive thin film. 12. A rectangular parallelepiped substrate having a shorter side having the same length as the length of a head slider of a magnetic head unit to be manufactured as a back surface, and a rectangular parallelepiped substrate having a thickness greater than the thickness of the head slider is polished from the back surface side. Forming grooves having a depth equal to or greater than the thickness of the head slider in parallel with the short side of the rectangle from the back surface side and at intervals obtained by adding the width of the grooves to the width of the head slider; Of all the surfaces formed on the substrate, at least
Perpendicular to the back surface, after forming a conductive thin film on all surfaces including the short side of the rectangle or parallel to the short side of the rectangle, from the sliding surface side opposite to the back surface, Separate each head slider by polishing until the thickness of the rectangular parallelepiped substrate is the same as the thickness of the head slider.
Forming a magnetic head unit. 13. A strip-shaped substrate on one surface of which a conductive thin film serving as a ground plane is formed, and a dielectric is formed on the conductive thin film, and then one or more pairs of microstrip lines are formed on the dielectric. A pair is formed such that its ground side line penetrates through the dielectric and is connected to the ground plane, and at least a side surface perpendicular to one surface of the substrate and parallel to the microstrip line pair is electrically conductive. A method for manufacturing a magnetic head unit, wherein a microstrip line unit is manufactured by depositing a thin film. 14. A magnetic recording / reproducing apparatus comprising the magnetic head unit according to claim 8, wherein the magnetic recording medium is configured to be grounded, wherein the magnetic recording medium is not the ground-side line of the pair of microstrip lines. A magnetic recording / reproducing apparatus, wherein a line is disposed between the ground plane and the magnetic recording medium. 15. A magnetic recording / reproducing apparatus comprising the magnetic head unit according to claim 9, wherein a magnetic recording medium is configured to be grounded, wherein the reproduction signal microstrip line pair is provided. A magnetic recording / reproducing apparatus, wherein a line other than the ground-side line is disposed between the ground plane and the magnetic recording medium. 16. A magnetic recording / reproducing apparatus comprising the magnetic head unit according to claim 8, wherein the magnetic recording medium is configured to be grounded, wherein the magnetic recording medium of the head slider is provided. A magnetic recording / reproducing apparatus, wherein a projection surface on a surface is included in a projection surface of the ground surface onto the surface of the magnetic recording medium.