JP3477516B2 - Apparatus and method for detecting charged particle emission using magnetoresistive element - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for measuring charged particles emitted from a sliding contact portion between solids, particularly a frictional contact portion between a magnetic recording head of a magnetic recording device of a computer and a magnetic disk (hard disk). It is used to measure the positive and negative charged particles emitted.

[0002]

2. Description of the Related Art When a solid and a solid are in sliding contact with each other, frictional electrification occurs, and microplasma is generated due to discharge in the vicinity of the contact portion, and electrons, negative ions, and positive ions are emitted. So far, in the pin-disk friction tester in the laboratory, among these charged particles, positive ions are positively charged particles, electrons,
Negative ions and a mixture of electrons and negative ions are measured as negatively charged particles. Furthermore, it has been clarified that charged particles are released, that is, chemi-emission occurs due to the interaction between the new surface and surrounding molecules due to friction between solids.

Further, in a magnetic recording apparatus comprising a magnetic recording head and a rotating magnetic disk, positive and negative charged particle emission is measured in a pin-disk friction test simulating a head coating material and a hard disk coating film. Has been done. This indicates that the same phenomenon occurs at the contact surface between the magnetic recording head and the magnetic disk of the actual magnetic recording device. It is considered that these phenomena cause electrical noise in the magnetoresistive element, destroy the magnetoresistive element itself, decompose and deteriorate the lubricating oil thin film, and cause various troubles such as magnetic recording error.

In the current magnetic recording apparatus, the magnetic recording head is floated above the disk by the fluid lubrication action of air to the head by the rotating magnetic disk, but both are forced to contact each other when the computer is started and stopped. It Further, in order to improve the magnetic recording density, technological development has been carried out to reduce the distance between the magnetic recording head and the magnetic disk to the utmost limit. Ultimately, development of a contact type magnetic recording device in which a magnetic recording head and a magnetic disk contact each other is urgently needed. In this contact-type magnetic recording device, microplasma and chemi-emission are generated by the above discharge,
It is obvious that various troubles will occur. In order to develop a next-generation ultra-high density magnetic recording device, it is essential to develop technology for preventing troubles due to these phenomena.

For that purpose, it is necessary to investigate in detail the generation state of microplasma and chemi-emission generated at the contact portion between the actual magnetic recording head and the magnetic disk by the charged particle emission measurement.

However, although a simple pin-disk tester has been used for measurement, a device for measuring positive and negative charged particles generated at the sliding interface of the head-disk in an actual machine has not been developed so far. .

[0007]

The intensity of the charged particles emitted from the frictional contact portion between the minute magnetic recording head and the magnetic disk under a light load is extremely weak, and the generated microplasma is generated in the frictional contact portion. Since it occurs in an extremely narrow range of several micrometers, there is a problem that the detector of the charged particles must be minute and extremely close to the contact portion between the head and the disk in order to collect this.

Therefore, an object of the present invention is to provide a magnetic recording head, which is very close to the contact portion between the magnetic recording head and the magnetic disk, and for reading a weak magnetic line of force from a memory signal of the magnetic disk. Using a magnetoresistive element itself as a detector, a charged particle emission detection device capable of creating a charged particle measurement circuit and observing the actual emission state of charged particles on a computer magnetic disk of an actual machine. There is something to do.

[0009]

In order to achieve the above object, a charged particle measuring apparatus using a magnetoresistive element according to the present invention is a charging device attached to a detector head which makes frictional contact with an object at a minute frictional contact portion. The charged particle collecting device includes: a particle collecting device; a charged particle measuring device that is in contact with the charged particle collecting device through a current lead wire; and a trigger circuit that controls the operation of the charged particle measuring device. The element is attached to the detector head while being exposed to the subject in a non-contact manner in a state of being shielded by a shield member, and the charged particle collecting element is made of a magnetoresistive material, At least the charged particle measuring device,
The current of the charged particles input from the charged particle collecting element,
Alternatively, it is characterized by having a function of amplifying and integrating charges or a voltage obtained by converting the charges.

A charged particle measuring apparatus using a magnetoresistive element according to the present invention includes a magnetic head, a magnetic recording disk that comes into contact with the magnetic head while rotating, a magnetoresistive element provided at the rear of the magnetic head, and a magnetoresistive element. It consists of a current lead wire connected to both ends of the device, a charged particle measuring device, a personal computer, a display device, and a trigger circuit. Furthermore,
The charged particle measuring method using the magnetoresistive element of the present invention is
A magnetoresistive element of a reproducing magnetic head of a magnetoresistive effect type magnetic recording device is connected to a charged particle measuring device via a current lead wire, and charged particles generated at a contact portion between the magnetic head and a magnetic disk are described above. The present invention is characterized in that the current of the charged particles, the electric charge, or the voltage obtained by converting the electric charge is collected by the magnetoresistive element and amplified and counted by the charged particle measuring device.

[0011]

The magnetoresistive element collects weak positive or negative charged particles emitted from the contact portion between the magnetic disk and the magnetic head, and transmits them to the charged particle measuring device.

[0012]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. First, a charged particle detection device used in the charged particle detection method using the magnetoresistive element of the present invention will be described. As shown in FIGS. 1 and 2, a charged particle detection device 100a using the magnetoresistive element of the present invention is
The charged particle trapping element 1a attached to the detector head 2a that makes frictional contact with the subject 6a at the minute frictional contact portion.
A charged particle measuring device 10 connected to the charged particle collecting element 1a via a current lead wire 9 and a trigger circuit 13 for controlling the operation of the charged particle measuring device 10.
The charged particle collecting element 1a is attached to the detector head 2a in a state where it is exposed to the object 6a in a non-contact manner and is shielded from the object 6a by the shield member 4a, and the charged particle collecting element 1a is also attached. Is composed of a magnetoresistive material, and the charged particle measuring apparatus 1a at least amplifies and integrates the current or charge of the charged particles inputted from the charged particle collecting element, or the voltage obtained by converting the charges. It has a function.

Next, the charged particle emission detection device 1 described above
Charged particle emission detection device 10 in which 00a is configured by using a reproducing head of an existing magnetic disk device for a computer
An embodiment configured as 0 will be described.

The magnetoresistive element 1 used as a detector (charged particle collecting element) of the apparatus 100 is installed inside the reproducing portion of a magnetic head 2 for recording / reproducing through a current lead wire 3. The front and rear of the magnetoresistive element 1 are sandwiched by shields 4. The shield 4 and the bottom surface of the magnetic head 2 are generally diamond-like carbon (DL).
C) It is coated with a protective film 5. The magnetic recording layer 7 of the rotating magnetic disk 6 is also coated with a DLC protective film 8. A current lead wire 3 is coupled to both ends of the magnetoresistive element 1. Since the magnetoresistive element 1 is shorter than the shield 4, even if the magnetic head 2 and the rotating magnetic disk 6 come into contact with each other, the contact occurs between the DLC protective film 5 coated on the shield 4 and the DLC protective film 8 of the disk. The resistance element 1 does not contact the magnetic disk 6.
Due to the contact between the DLC protective films, microplasma and chemi-emission are generated in the contact part and its vicinity, and positive ions, electrons, and negative ions generated during the plasma and chemi-emission are released as positive and negative charged particles. It

The magnetoresistive element 1 is originally provided in the reproducing portion of the magnetic head to detect magnetic lines of force from the recording signal inside the magnetic recording layer 7, and there was a circuit therefor, but these were removed. As shown in FIG. 2, the other ends of the two current lead wires 3 are combined into one, and the combined current lead wire 9 forms one charged particle measuring device 1
It is tied to zero. As a result, the magnetoresistive element 1 is in a state in which its function is changed to a charged particle detector. The positive and negative charged particles generated at the contact portion between the magnetic head 2 and the rotating magnetic disk 6 are collected by the magnetoresistive element 1,
After passing through the current lead wire 3 and the current lead wire 9, they are amplified and integrated by the charged particle measuring device 10, processed by the personal computer 11 for signal processing, and displayed by the display device 12. On this occasion,
The measurement is started by the trigger circuit 13 coupled to the charged particle measuring device.

Generally, the magnetoresistive element 1 is made of a ferromagnetic material of Ni, Fe, Co or an alloy thereof, for example, an alloy such as Ni, Fe, etc., and is essentially a minute recording in the magnetic recording layer 7 of the magnetic disk 6. This is for detecting the weak magnetic lines of force of the magnetic element and detecting the signal of the magnetic element by the resistance change of the magnetoresistive element due to the change of the magnetic field strength. in this case,
By applying a predetermined magnetic field to both ends of the magnetoresistive element in advance, the resistance change due to the magnetic field change can be maximized. However, it is not necessary to obtain the signal of the magnetic field change by the magnetic element when detecting the charged particles. Therefore, from the electric circuit originally provided for functioning as the magnetic recording device, the current lead wire 3 of the magnetoresistive element 1 is provided.
Is separated, the ends of the two lead wires are combined or only one is left, and the combined or remaining lead wires are connected to the charged particle measuring device 10 to function as a charged particle detector. .

[0017]

As is apparent from the above, in the charged particle emission detection device using the magnetoresistive element of the present invention, the magnetoresistive element 1 in the reproducing portion of the magnetic head 2 is a charged particle detector, so that The positive and negative charged particles generated at the contact portion between the head 2 and the magnetic disk 6 can be efficiently measured.

In particular, when the charged particle detecting device is constructed by utilizing the reproducing head of the existing magnetic disk device for a computer, it is possible to detect the actual generation state of the charged particles in the actual machine.

[0019]

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a charged particle measuring device according to the present invention.

FIG. 2 is an explanatory diagram showing a measurement principle in the charged particle measuring method of the present invention.

[Explanation of symbols]

1 Magnetoresistive Element 1a Charged Particle Collection Element 2 Magnetic Head 2a Detector Head 3 Current Lead Wire 4 Shield 4a Shield Member 5 Diamond Like Carbon (DLC) Protective Film 6 Magnetic Disk 6a Subject 7 Magnetic Recording Layer 8 Diamond Like Carbon ( DLC) protective film 9 current lead wire 10 charged particle measurement device 11 personal computer 12 display device 13 trigger circuit 100 charged particle emission detection device 100a charged particle emission detection device

Claims (2)

(57) [Claims] 1. A magnetoresistive element in a reproducing section of a magnetic head of a magnetoresistive effect type magnetic recording apparatus is connected to a charged particle measuring apparatus via a current lead wire to generate at a contact section between the magnetic head and a magnetic disk. The charged particles to be charged are collected by the magnetoresistive element, and the current or charge of the charged particles or the voltage obtained by converting the charges is amplified and counted by the charged particle measuring device. A charged particle emission detection device using a resistance element. 2. A magnetoresistive element in a reproducing section of a magnetic head of a magnetoresistive effect type magnetic recording apparatus is connected to a charged particle measuring apparatus via a current lead wire, and generated at a contact section between the magnetic head and a magnetic disk. The charged particle emission detection method, characterized in that the charged particles to be collected are collected by the magnetoresistive element, and the current or charge of the charged particles or the voltage obtained by converting the charges is amplified and counted by the charged particle measuring device. .