JP2007010386A - Discharge detecting system and discharge detecting technique - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent destruction of magnetic heads by electric discharge. <P>SOLUTION: An end of a coaxial cable 10 arranging a core wire transmitting electric signal, an insulator, shielding materials, and insulating materials sequentially from within is prepared near a section polishing a magnetic head of a magnetic head polishing device 30. A discharge detecting device 20 connected to the coaxial cable 10 detects discharge generated by polishing of a magnetic head in the magnetic head polishing device 30. Thus, since the presence and degree of discharging can be checked, setting conditions, such as the polishing process polishing magnetic heads according to detected results, can be optimized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a discharge detection system for detecting discharge and a discharge detection method.

  As an apparatus for recording or reproducing a signal on a magnetic tape type magnetic recording medium, for example, there is a helical scan apparatus using a rotating drum. A magnetic head such as an MR (Magneto Resistive) head or a GMR (Giant Magneto Resistive) head is mounted on the rotating drum of this apparatus. These MR heads and GMR heads are equipped with thin film head elements formed by a thin film process. In the apparatus for recording or reproducing the signal, the magnetic head and the magnetic tape are brought into contact with each other on the outer peripheral surface of the rotating drum, and the signal is recorded or reproduced.

  Here, the manufacturing process of the magnetic head includes a polishing process for polishing the magnetic head, which is important. In this polishing step, a minute discharge due to friction occurs, and controlling this discharge is important for improving the quality of the magnetic head.

As a technique related to this, a technique for detecting a partial discharge generated in a power cable has been proposed (see, for example, Patent Document 1).
JP-A-6-66874

  As described above, in the polishing process for polishing the magnetic head, radiation noise generated by minute discharge due to friction occurs. The discharge that is the cause of the radiation noise destroys the magnetic head.

  The present invention has been made in view of these points, and an object of the present invention is to provide a discharge detection system and a discharge detection method for preventing discharge from destroying a magnetic head.

  In the present invention, in order to solve the above problems, as illustrated in FIG. 1, in a discharge detection system for detecting discharge, a magnetic head polishing apparatus 30 for polishing a magnetic head and a magnetic head of the magnetic head polishing apparatus 30 are provided. One end is disposed in the vicinity of the portion to be polished, and the core cable, the insulator, the shield material, and the coaxial cable 10 in which the insulating material is disposed in order from the inside are connected to the coaxial cable 10 and the magnetic head is polished. There is provided a discharge detection system including a discharge detection device 20 that detects a discharge generated by the discharge.

According to such a discharge detection system, the presence / absence and degree of discharge can be confirmed, so that setting conditions such as a polishing process for polishing the magnetic head can be optimized according to the detection result.
Further, in the present invention, in order to solve the above-mentioned problem, as illustrated in FIG. 1, in the discharge detection method for detecting discharge, in the vicinity of the portion of the magnetic head polishing apparatus 30 for polishing the magnetic head that polishes the magnetic head. A discharge detecting method is provided, in which one end of the coaxial cable 10 is disposed and a discharge generated by polishing the magnetic head is detected via the coaxial cable 10.

  According to such a discharge detection method, since the presence or absence and degree of discharge can be confirmed, it is possible to optimize setting conditions such as a polishing process for polishing the magnetic head according to the detection result.

In the present invention, the discharge generated by polishing the magnetic head is detected through the coaxial cable.
In this way, since the presence / absence and degree of discharge can be confirmed, setting conditions such as a polishing process for polishing the magnetic head can be optimized according to the detection result. Therefore, it is possible to prevent discharge from destroying the magnetic head.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiment of the present invention is applied to a magnetic head polishing apparatus for polishing a magnetic head.
First, the case where a discharge detection system is constructed for the magnetic head polishing apparatus will be described. FIG. 1 is a diagram showing a discharge detection system for a magnetic head polishing apparatus.

  The discharge detection system includes a coaxial cable 10, a discharge detection device 20, and a magnetic head polishing device 30. In addition, the magnetic head polishing apparatus 30 includes a rotating jig 31 and a rotating surface plate 32.

  Here, one end of the coaxial cable 10 is disposed in the vicinity of the portion of the magnetic head polishing device 30 that polishes the magnetic head, and the other end is connected to the discharge detection device 20. The coaxial cable 10 is formed by sequentially arranging a core wire, an insulator, a shield material, and an insulating material for transmitting an electric signal from the inside. The discharge detection device 20 detects a discharge generated by polishing the magnetic head via the coaxial cable 10. The magnetic head polishing apparatus 30 rotates a rotating jig 31 and a rotating surface plate 32 on which a magnetic head to be polished is mounted, and polishes the magnetic head.

  In such a discharge detection system for the magnetic head polishing apparatus 30, the rotating jig 31 and the rotating platen 32 on which the magnetic head to be polished is rotated in a polishing process or the like for polishing the magnetic head. Polished. Radiation noise generated by minute electrostatic discharge due to friction is generated at the interface between the rotating jig 31 and the rotating surface plate 32. The radiation noise is detected via the coaxial cable 10. The detection result is measured and displayed for each frequency band by the discharge detection device 20 such as a spectrum analyzer. This measurement result confirms electrostatic discharge.

Next, the coaxial cable 10 used in the first embodiment will be described. FIG. 2 is a diagram illustrating the coaxial cable according to the first embodiment.
The coaxial cable 10 has a shield material 12 encased in an insulating material 11 and partially exposed to the outside. This shield material 12 is a mesh braid having a twisted structure. Further, the coaxial cable 10 has an insulator 13 wrapped in a shield material 12. The coaxial cable 10 has a core wire 14 that is encased in an insulator 13 and partly exposed to the outside. The length of the exposed portion of the core wire 14 is several mm.

  Here, the insulating material 11 electrically insulates the coaxial cable 10 from the outside. The insulating material 11 protects the coaxial cable 10 and maintains its shape. The shield material 12 prevents an electromagnetic wave caused by an electrical signal transmitted to the core wire 14 from leaking outside. The shield material 12 prevents electromagnetic waves from entering from the outside. The insulator 13 electrically insulates the shield material 12 and the core wire 14. The insulator 13 protects the core wire 14 and maintains its shape. The core wire 14 transmits an electrical signal. Moreover, the core wire 14 adjusts the sensitivity of the discharge detection apparatus 20 by adjusting the length of the exposed part.

  In such a coaxial cable 10, the length of the exposed core wire 14 is adjusted according to the radiation noise from the surrounding devices, and the sensitivity of the discharge detection device 20 is adjusted. Specifically, when there is little radiation noise from surrounding devices, the length of the exposed core wire 14 is lengthened, and the sensitivity of the discharge detection device 20 is improved. Moreover, when there is much radiation noise from surrounding devices, the length of the exposed core wire 14 is shortened, and the sensitivity of the discharge detection device 20 is lowered.

The sensitivity of the discharge detection device 20 may be adjusted by wrapping a part of the exposed core wire 14 with the shield material 12.
Next, the shield jig attached to the coaxial cable 10 will be described. FIG. 3 is a diagram illustrating the shield jig according to the first embodiment.

  The shield jig 15 has a cylindrical shape made of metal and is disposed so as to cover all or part of the insulating material 11, the shielding material 12, the insulator 13, and the core wire 14. The shield jig 15 can move in a direction parallel to the insulating material 11.

  In such a shield jig 15, the length of the shield jig 15 covering the exposed core wire 14 is adjusted according to the radiation noise from the surrounding devices, and the sensitivity of the discharge detection device 20 is adjusted. Specifically, when the radiation noise from the surrounding devices is small, the length of the shield jig 15 covering the exposed core wire 14 is shortened to improve the sensitivity of the discharge detection device 20. Moreover, when there is much radiation noise from the surrounding apparatus, the length which the shield jig | tool 15 covers the exposed core wire 14 is lengthened, and the sensitivity of the discharge detection apparatus 20 is reduced.

Next, the coaxial cable 10a used in the second embodiment will be described. FIG. 4 is a diagram illustrating a coaxial cable according to the second embodiment.
The coaxial cable 10a has a shield material 12a that is encased in an insulating material 11a and partially exposed to the outside. This shield material 12a is a braided wire having a twisted structure. The coaxial cable 10a has an insulator 13a that is encased in a shield material 12a and partially exposed to the outside. The length of the exposed portion of the insulator 13a is several mm. The coaxial cable 10a has a core wire 14a wrapped in an insulator 13a.

  Here, the insulating material 11a electrically insulates the coaxial cable 10a from the outside. The insulating material 11a protects the coaxial cable 10a and maintains its shape. The shield material 12a prevents an electromagnetic wave caused by an electrical signal transmitted to the core wire 14a from leaking outside. The shield material 12a prevents electromagnetic waves from entering from the outside. The insulator 13a electrically insulates the shield material 12a and the core wire 14a. The insulator 13a protects the core wire 14a and maintains its shape. Moreover, the insulator 13a adjusts the sensitivity of the discharge detection device 20 by adjusting the length of the exposed portion. Further, the insulator 13a prevents the generation of noise due to the contact between the core wire 14a and the device to be detected, and the inflow of current to the core wire 14a. The core wire 14a transmits an electrical signal.

  In such a coaxial cable 10a, the length of the exposed insulator 13a is adjusted according to the radiation noise from the surrounding devices, and the sensitivity of the discharge detection device 20 is adjusted. Specifically, when there is little radiation noise from surrounding devices, the length of the exposed insulator 13a is increased to improve the sensitivity of the discharge detection device 20. Moreover, when there is much radiation noise from surrounding devices, the length of the exposed insulator 13a is shortened, and the sensitivity of the discharge detection device 20 is lowered.

In addition, you may adjust the sensitivity of the discharge detection apparatus 20 by wrapping a part of core wire 14a wrapped in the insulator 13a with the shielding material 12a.
Next, the shield jig attached to the coaxial cable 10a will be described. FIG. 5 is a diagram illustrating a shield jig according to the second embodiment.

  The shield jig 15a has a cylindrical shape made of metal and is disposed so as to cover all or a part of the insulating material 11a, the shielding material 12a, the insulator 13a, and the core wire 14a. The shield jig 15a can move in a direction parallel to the insulating material 11a.

  In such a shield jig 15a, the length that the shield jig 15a covers the exposed insulating material 11a is adjusted according to the radiation noise from the surrounding devices, and the sensitivity of the discharge detection device 20 is adjusted. Specifically, when the radiation noise from surrounding devices is small, the length of the shield jig 15a covering the exposed insulating material 11a is shortened, and the sensitivity of the discharge detection device 20 is improved. Further, when there is a lot of radiation noise from the surrounding devices, the length of the exposed insulating material 11a covered by the shield jig 15a is increased, and the sensitivity of the discharge detection device 20 is lowered.

  According to each of the above embodiments, the electrostatic discharge generated by polishing the magnetic head can be detected via the coaxial cables 10 and 10a, and the presence and degree of the electrostatic discharge can be confirmed. Thus, the setting conditions such as a polishing process for polishing the magnetic head can be optimized. Specifically, the voltage values of the rotating jig 31 and the rotating surface plate 32 are optimized so that the discharge is reduced. Further, the rotational speeds of the rotating jig 31 and the rotating surface plate 32 are optimized. Further, the type of lubricating oil disposed between the rotating jig 31 and the rotating surface plate 32 is optimized. In addition, the type and number of diamonds and the like arranged on the rotating platen 32 for polishing the magnetic head are optimized. Therefore, radiation noise generated by minute electrostatic discharge due to friction can be prevented from destroying the magnetic head.

  In addition, in the polishing process for polishing the magnetic head, etc., the sensitivity of the discharge detection device 20 is adjusted in accordance with the radiation noise from the surrounding device. Therefore, the radiation noise from the surrounding device or radiation generated by minute electrostatic discharge due to friction. Can determine whether it is noise.

In addition, in the predetermined manufacturing process other than the polishing process, even when radiation noise generated by minute electrostatic discharge occurs, the electrostatic discharge can be detected.
In addition, in a predetermined apparatus other than the magnetic head polishing apparatus 30, even when radiation noise generated by a minute electrostatic discharge occurs, the electrostatic discharge can be detected.

In addition, an electric signal converted from radiation noise can be amplified by an amplifier (not shown).
(Supplementary note 1) In a discharge detection system for detecting discharge,
A magnetic head polishing apparatus for polishing the magnetic head;
One end is disposed in the vicinity of the portion of the magnetic head polishing apparatus for polishing the magnetic head, a core wire for transmitting an electrical signal, an insulator, a shield material, and a coaxial cable in which the insulating material is sequentially disposed from the inside,
A discharge detecting device connected to the coaxial cable and detecting discharge generated by polishing the magnetic head;
A discharge detection system comprising:

  (Appendix 2) The one end of the coaxial cable has the shield material wrapped in the insulating material and partly exposed to the outside, the insulator is wrapped in the shield material, and the core wire is wrapped in the insulator. The discharge detection system according to appendix 1, wherein a part of the discharge detection system is exposed to the outside.

  (Appendix 3) The one end of the coaxial cable is partially exposed to the outside when the shield material is encased in the insulating material, and partially exposed to the outside when the insulator is encased in the shield material, The discharge detection system according to appendix 1, wherein the core wire is encased in the insulator.

(Supplementary note 4) The discharge detection system according to supplementary note 1, wherein the electrical signal is transmitted to the discharge detection device via an amplifier that amplifies the electrical signal.
(Additional remark 5) In the discharge detection method which detects discharge,
One end of a coaxial cable is disposed in the vicinity of the portion of the magnetic head polishing apparatus for polishing the magnetic head, and the discharge generated by polishing the magnetic head is detected via the coaxial cable. Discharge detection method characterized.

(Additional remark 6) In the discharge detection apparatus which detects discharge,
One end is arranged in the vicinity of the portion for polishing the magnetic head, and a coaxial cable in which the core wire, the insulator, the shielding material, and the insulating material for transmitting an electric signal are sequentially arranged from the inside,
A discharge detecting means connected to the coaxial cable for detecting a discharge generated by polishing the magnetic head;
A discharge detection device comprising:

It is a figure which shows the discharge detection system with respect to a magnetic head polisher. It is a figure which shows the coaxial cable of 1st Embodiment. It is a figure which shows the shield jig | tool of 1st Embodiment. It is a figure which shows the coaxial cable of 2nd Embodiment. It is a figure which shows the shield jig | tool of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Coaxial cable 20 Discharge detection apparatus 30 Magnetic head grinding | polishing apparatus 31 Rotating jig 32 Rotating surface plate

Claims (5)

In a discharge detection system for detecting discharge,
A magnetic head polishing apparatus for polishing the magnetic head;
One end is disposed in the vicinity of the portion of the magnetic head polishing apparatus for polishing the magnetic head, a core wire for transmitting an electrical signal, an insulator, a shield material, and a coaxial cable in which the insulating material is sequentially disposed from the inside,
A discharge detecting device connected to the coaxial cable and detecting discharge generated by polishing the magnetic head;
A discharge detection system comprising:   The one end of the coaxial cable is partially exposed by the shield material being encased in the insulating material and partially exposed to the outside, the insulator being encased in the shield material, and the core wire being encased in the insulator. The discharge detection system according to claim 1, wherein is exposed to the outside.   The one end of the coaxial cable has the shield material wrapped in the insulating material and partly exposed to the outside, the insulator is wrapped in the shield material and partly exposed to the outside, and the core wire is The discharge detection system according to claim 1, wherein the discharge detection system is encased in an insulator.   The discharge detection system according to claim 1, wherein the electrical signal is transmitted to the discharge detection device via an amplifier that amplifies the electrical signal. In the discharge detection method for detecting discharge,
One end of a coaxial cable is disposed in the vicinity of the portion of the magnetic head polishing apparatus for polishing the magnetic head, and the discharge generated by polishing the magnetic head is detected via the coaxial cable. Discharge detection method characterized.

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