JP2002083407A - Magnetoresistive magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an MR head provided with an auxiliary substrate strong to electrostatic breakdown. SOLUTION: In, the magnetoresistive magnetic head provided with an auxiliary substrate, its main substrate and the auxiliary substrate are grounded to the same conductive member as a ground potential. A conductive material having a specific resistance value smaller than the main substrate and the auxiliary substrate is formed on at least a part excluding a head sliding surface, the main substrate and the auxiliary substrate are electrically connected to each other, and a similar effect is provided even when at least one of the main substrate and the auxiliary substrate is set at a ground potential. As a specific method of electrically connecting the main substrate and the auxiliary substrate to each other, a conductive material is formed on in a step part for regulating a sliding width by using a thin film forming technology such as a sputtering method, a deposition method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive head provided with an auxiliary substrate for detecting a signal from a magnetic recording medium by sliding with the magnetic recording medium. The present invention relates to a magnetoresistive effect type magnetic head device having an auxiliary substrate, which is configured to remove static electricity generated when sliding with a recording medium such as a magnetic tape during recording / reproducing of signals. is there.

[0002]

2. Description of the Related Art In recent years, in the field of magnetic disks, a magneto-resistive effect type magnetic head (Magneto Resistiv
e head, hereinafter abbreviated as MR head). MR
The head is a reproducing head using a magnetoresistive element (hereinafter, abbreviated as MR element) whose electric resistance changes according to the strength of a magnetic field.

[0003] MR heads can be roughly classified from the aspect of the MR element to which they are applied.
sotropic Magneto Resistive head), GMR head using giant magnetoresistive effect (Giant Magneto Resistive head), TMR head using tunnel magnetoresistive effect (Tun
nel Magneto Resistive heads), and in the field of magnetic disks, products equipped with GMR heads are currently the mainstream, and research on TMR heads with high sensitivity for the purpose of further increasing the recording density is active. It is.

On the other hand, in the field of a tape streamer using a magnetic tape as a recording medium, a helical scan method in which a magnetic head mounted on a rotating drum scans a magnetic tape obliquely to record / reproduce a signal is used. There are systems that are. The magnetic heads used for these are, as a recording head, a so-called composite type magnetic head combining a metal magnetic film having a high saturation magnetic flux density and ferrite, or a metal magnetic film having a high saturation magnetic flux density on a non-magnetic substrate. A so-called laminated magnetic head having a laminated structure is mainly used, and as a reproducing head, an electromagnetic induction type magnetic head such as a ferrite head, a composite magnetic head employing a multilayer film structure, a laminated magnetic head, etc., a so-called inductive head. Used. However, in order to realize the recent demand for higher recording density and higher transfer rate, it is necessary to use the above-mentioned MR head, which can obtain higher output than the conventional inductive head, as a reproducing head. The research and development of applying this to magnetic tape systems has been actively conducted. For example, in the Technical Report of the Institute of Electronics, Information and Communication Engineers (MR99-70, 1999-12, p.21-p.27), an AMR head was used under the title `` High-density recording / reproduction characteristics of a rotating drum-mounted MR head. '' Reports have been made. The MR head reported in this report adopts a shielded magnetic head structure conventionally used in a magnetic disk drive, and is composed of an auxiliary substrate joined at an upper portion. By joining the auxiliary substrate in this manner, the sliding surface shape of the head can be made substantially the same as that of the conventional inductive head, and the existing technology can be applied to the problem of sliding between the tape and the head.

As described above, the MR head has a higher sensitivity as a reproducing head than a conventional inductive magnetic head. However, as is well known, MR
The element is susceptible to static electricity, and it is important to prevent the electrostatic discharge of the MR element. As a countermeasure against electrostatic breakdown of the MR head, for example, as disclosed in JP-A-6-251338, the potential of the magnetoresistive thin-film magnetic circuit formed on the conductive substrate and the potential of the conductive substrate are grounded. It has been shown that it is effective to maintain the potential.

[0006]

In a system in which an MR head and a tape medium are combined, a cylindrical grinding process at the time of head processing, a polishing surface forming and polishing process using a polishing tape, and a sliding operation with the tape in an actual running state. It comes into contact with whetstones, polishing tapes, and magnetic tape as a medium. In the cylindrical grinding process, the MR element may not be polished, but the sliding of the MR head and the polishing tape or the magnetic tape is inevitable in the polishing of forming the sliding surface with the polishing tape or in the actual running state. For this reason, the charge accumulated on the tape jumps into the magnetoresistive head and the MR element is damaged.
It has been found that there is a problem that so-called electrostatic breakdown occurs and lowers the yield of the MR head.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an MR with an auxiliary substrate which is resistant to electrostatic breakdown.
Is to provide the head.

[0008]

SUMMARY OF THE INVENTION The present invention has been derived from the results of detailed examinations on the improvement of the yield and the head reliability in the head processing step of an MR head having an auxiliary substrate.

In other words, it is clear that the MR head provided with an auxiliary substrate and having a countermeasure against static electricity used in a conventional magnetic disk and the MR head provided with an auxiliary substrate have different resistance to electrostatic breakdown against sliding of a tape or the like. Was.

After the completion of the MR element formed on the main substrate, the auxiliary substrate is electrically floated because it is bonded to the protective film forming surface side. It is considered that a current path that passes through the protective film joined to the substrate to the main substrate is employed. As a result of an experimental verification, it has been clarified that many defects such as an increase in the MR resistance value occur in the MR head in which the auxiliary substrate is electrically floated.

From this, it can be seen that preventing charging of the auxiliary substrate leads to improvement in yield and reliability of the MR head having the auxiliary substrate.

More specifically, the present invention is realized by a magnetoresistive magnetic head characterized in that the main substrate and the auxiliary substrate are grounded to the same conductive member at a ground potential. By doing so, the potential difference between the auxiliary substrate and the main substrate is eliminated, and the charge flowing into each substrate does not pass through the MR element portion.

As the grounding member, a head base having a ground potential is preferable. If necessary, the MR head joint portion of the head base is formed to have a shape protruding toward the auxiliary substrate side, so that the head substrate can be connected to the auxiliary substrate side. The head base is securely joined and effective.

A conductive material having a lower specific resistance than the main substrate and the auxiliary substrate is formed on at least a part except for the head sliding surface to electrically connect the main substrate and the auxiliary substrate. The same effect can be obtained when at least one of them is at the ground potential. As a specific method of electrically connecting the main substrate and the auxiliary substrate, a conductive material is formed on a step portion that regulates a sliding width by using a thin film forming technique such as a sputtering method, an evaporation method, or a plating method. It is valid.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail.

FIG. 1 shows an example of a magnetic head device 1 according to a first embodiment of the present invention. A main substrate and an auxiliary substrate of an MR head 2 having an auxiliary substrate shown in FIG. In addition, the head base is structured to be at the ground potential. This embodiment is an example of application to a magnetic recording / reproducing apparatus employing a helical scan method.

In FIG. 2, 10 is a main substrate, 11 is a head portion including a recording head and a reproducing head formed on the main substrate 10, 12 is a protective film formed for protecting the head portion 11, 13 Is an auxiliary substrate, 14 is an electrode terminal, and 15 is a sliding width regulating groove.

FIG. 3 is an enlarged view of the head section 11. As shown in FIG. 3, the protective film 12 shown in FIG. 2 is omitted. In FIG. 3, 10 is a main substrate, 21 is a base film formed on the main substrate, 22 is a lower magnetic shield film, and 23 is an upper magnetic shield film. Reference numeral 24 denotes an MR element, and reference numeral 25 denotes electrodes connected to both sides of the MR element 24. 26 is an upper core of the recording head, 27 is a coil of the recording head, and 28 is a recording gap.

Next, a method of manufacturing the MR head device of the present invention will be described with reference to FIGS.

First, as shown in FIG. 4, the head portion 11, the main substrate 10 on which the protective film is formed, and the auxiliary substrate 13 are joined using an adhesive such as a resin to obtain a bonding block 41. Here, the electrode terminals 14 shown in FIG. 2 are not shown. Next, as shown in FIG. 5, the sliding width regulating groove 51 is formed using a cutting device such as a dicer or a wire saw so as to obtain a predetermined sliding width, and the bonding provided with the sliding width regulating groove 51 is performed. Get block 52. Subsequently, the sliding surface of the bonding block 52 is subjected to a curved surface processing and cut along the imaginary line 61 shown in FIG. 6 to obtain the head chip 2 shown in FIG. This is ground-bonded to the head base 3 to obtain the magnetic head device 1 shown in FIG. Here, the curved surface processing of the head is performed after forming the sliding width regulating groove, but the sliding width regulating groove may be processed after the curved surface processing is performed on the bonding block 41.

The size (length in the MR height direction) of the auxiliary substrate is restricted by the position and size of various terminal plates on the joint surface of the main substrate and the workability of connecting wires and the like to the various terminal plates. receive. If the size of the auxiliary substrate (length in the MR height direction) cannot be obtained sufficiently, as shown in FIGS. It is effective to provide a projection. Further, by providing the wire guide groove 70, the auxiliary substrate is reliably grounded to the head base, and the wires connected to the terminal plate from the lower portion of the auxiliary substrate can be easily connected to the terminal plate (not shown) of the head base. It can be pulled out, which leads to improvement in the work efficiency of the wire connection work.

An auxiliary substrate having the above configuration is provided.
With the MR head, damage to the MR head due to static electricity can be prevented.

In the present embodiment, a head having a configuration in which a recording head and an MR head are combined has been described as an example.
The same effect can be obtained even in the case of a read-only head including only the MR head.

FIG. 9 shows an example of a magnetic head device 1 'according to a second embodiment of the present invention. The main substrate of an MR head 2' having an auxiliary substrate shown in FIG. And the head base has a structure of a ground potential. This embodiment is an example of application to a magnetic recording / reproducing apparatus employing a helical scan method.

In FIG. 10, the same parts as those in FIG. 2 are denoted by the same reference numerals. MR head 2 'with auxiliary substrate
Has a conductive material 71 formed in the sliding width regulating groove 15,
The main board and the auxiliary board are electrically connected.

Next, a method of manufacturing an MR head device according to the present invention will be described with reference to FIGS.

The steps up to obtaining the bonding block 52 provided with the sliding width regulating groove shown in FIG. 5 are the same as in the first embodiment. Next, a conductive material 71 having a lower specific resistance than the substrate material is formed inside the sliding width regulating groove of the bonding block 52 provided with the sliding width regulating groove using thin film forming equipment such as sputtering or vapor deposition. A bonding block 72 as shown in FIG. 11 is obtained. Subsequently, the head chip 2 'shown in FIG. 10 is obtained by performing the curved surface processing as shown in FIG. The head device shown in FIG. 9 is attached by attaching this head chip to a head base.
1 'is obtained.

In the head device shown in FIG. 9, since the main substrate and the auxiliary substrate are made of a conductive material and have the same potential, at least one of the main substrate and the auxiliary substrate is grounded to the head base. A magnetic head device having a high resistance to static electricity can be obtained.

An auxiliary substrate having such a configuration is provided.
With the MR head, damage to the MR head due to static electricity can be prevented.

In the present embodiment, a head having a configuration in which a recording head and an MR head are combined has been described as an example.
The same effect can be obtained even in the case of a read-only head including only the MR head.

[0031]

As described above, the magneto-resistive magnetic head for detecting a signal from the magnetic recording medium by sliding with the magnetic recording medium uses the main substrate on which the MR element is formed and the auxiliary substrate. The MR element part is sandwiched between the main substrate and the auxiliary substrate and integrally joined, and the magnetoresistive effect type magnetic head whose head sliding surface is regulated by the sliding width regulating groove is attached to the head base. In a magnetoresistive head device integrally joined, the main substrate and the auxiliary substrate are grounded to the same conductive member having a ground potential. The proof stress against is greatly improved.

Also, a magnetoresistive head having an auxiliary substrate is integrally connected to the head base, and the head base at the joint between the head base and the magnetoresistive head is convex in the direction of the auxiliary substrate. In the magnetic head device characterized in that the auxiliary substrate and the head base can be reliably ground-bonded, and the resistance to static electricity is improved.

Further, a conductive material having a lower resistance than the main substrate and the auxiliary substrate is formed in the sliding width regulating groove,
Even when at least one of the main substrate and the auxiliary substrate is at the ground potential, the resistance to static electricity is similarly improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an MR head according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of an MR head according to a first embodiment including an auxiliary substrate.

FIG. 3 is an enlarged view of a head unit.

FIG. 4 is an explanatory diagram of the method for manufacturing the MR head according to the first embodiment.

FIG. 5 is an explanatory diagram of the method for manufacturing the MR head according to the first embodiment.

FIG. 6 is an explanatory diagram of the method for manufacturing the MR head according to the first embodiment.

FIG. 7 shows an M in which an MR head is integrally joined to a head base.
FIG.

FIG. 8 shows an M in which an MR head is integrally joined to a head base.
FIG.

FIG. 9 is a schematic diagram of an MR head according to a second embodiment of the present invention.

FIG. 10 is a schematic view of an MR head according to a second embodiment including an auxiliary substrate.

FIG. 11 is an explanatory diagram of the method for manufacturing the MR head according to the second embodiment.

FIG. 12 is an explanatory diagram of the method for manufacturing the MR head according to the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic head device of this invention, 1 '... Magnetic head device of this invention, 2 ... MR head, 2' ... MR head which formed conductive material in the sliding width | variety restricting groove, 3 ... Head base, 3 '... Head base having a convex shape on the auxiliary substrate side, 3 '' ... Head base having a convex shape on the auxiliary substrate side, 10 ... Main substrate, 11 ... Head part, 12 ... Protective film, 13 ... Auxiliary substrate, 14 ... Electrode terminals , 15: groove for restricting sliding width, 21: base film, 22: lower magnetic shield film,
23: Upper magnetic shield film, 24: MR element part, 25: Electrode, 26
... upper core of recording head, 27 ... coil of recording head, 28
… Recording gap, 41… bonding block, 51… sliding width regulating groove, 52… bonding block after processing the sliding width regulating groove, 61… virtual line, 70… wire guiding groove, 71… conductive material, 72… conductive Bonding block after formation of conductive material.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Noboru Hotta 1410 Inada, Hitachinaka-shi, Ibaraki Co., Ltd. Digital Media Products Division, Hitachi, Ltd. Hitachi Digital Media Products Division F term (reference) 5D034 AA02 BA02 BA18 BA19 BB12 BB20 CA07 DA07 5D093 AB03 BA20 BB01 BB04 CA07 5D111 AA11 AA12 AA19 BB01 BB09 BB50 FF01 HH16 JJ22 KK06

Claims (4)

[Claims] 1. A magnetoresistive magnetic head for detecting a signal from a magnetic recording medium by sliding with the magnetic recording medium, comprising: a magnetoresistive element unit; a main substrate; and an auxiliary substrate. The magnetoresistive element portion is sandwiched between the main substrate and the auxiliary substrate and integrally joined, and the main substrate and the auxiliary substrate are connected to a conductive member that is set to a ground potential. Magnetoresistive magnetic head. 2. A magnetoresistive magnetic head for detecting a signal from a magnetic recording medium by sliding with the magnetic recording medium, comprising: a main substrate; an auxiliary substrate having an outer dimension smaller than the main substrate; A head base as a conductive member, the head base having a convex protrusion on an upper part thereof; The main substrate is connected to the head base, the auxiliary substrate is connected to the head base only at the protrusion, and the head base is set to a ground potential. head. 3. A magnetoresistive effect type magnetic head for detecting a signal from the magnetic recording medium by sliding with the magnetic recording medium, comprising: a magnetoresistive element portion; a main substrate; and an auxiliary substrate. The magnetoresistive element section is sandwiched and integrally joined between the main substrate and the auxiliary substrate, and has at least a portion except for a head sliding surface that slides with the magnetic recording medium, in comparison with the main substrate and the auxiliary substrate. A conductive material having a small resistance value is formed, and the main substrate and the auxiliary substrate are electrically connected to each other, and at least one of the main substrate and the auxiliary substrate is connected to another conductive member having a ground potential. A magnetoresistive effect type magnetic head. 4. A method according to claim 1, wherein the magnetic head having the auxiliary substrate has a concave step portion for regulating a sliding width in the magnetoresistive head, and a conductive material is formed on the step portion. 4. The magneto-resistance effect type magnetic head according to claim 1, wherein: