JPH10143831A - Device and method for inspecting magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generally evaluate and inspect relation between the reliability of a magnetic disk device and dust. SOLUTION: A transparent disk substrate 11 is covered by a thin film 11A, which is of the same material as a magnetic disk and which has a thickness so as not to impair the optical transparency; with this disk substrate 11 rotated and with a magnetic head slider 14 brought into slidable contact with the rotating disk substrate, the thin film is thereby made to stick to the air bearing surface of the slider in the form of an abrasion powder from the disk surface layer. Then, the floating posture and quantity of the slider incident to the formation of the adhered powder are observed through an optical observation system, the vibration state of the slider is measured through a vibration measuring system, the electric resistance of the head element is also measured through a resistance measuring system and, on the basis of each of these continuous measurements, it is made possible to compare and decide resistance against contamination of the slider.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus and an inspection method for a magnetic head used on a magnetic storage device and mounted on a magnetic head slider.

[0002]

2. Description of the Related Art In recent years, as the density of magnetic disk devices has increased, the flying height of a magnetic head has been required to be reduced. There is a demand for floating stability that can maintain a posture. The first factor that impairs the flying attitude of the magnetic head slider is a phenomenon in which dust in the magnetic disk device, a lubricating film, a protective film, and the like of the magnetic disk adhere to the air bearing surface of the magnetic head slider. In such a case, there is an urgent need to suppress the formation of the attached matter or to develop a slider whose flying attitude does not change even if the attached matter is formed.

[0003] Here, the following documents are known as related to the reliability evaluation of a magnetic head slider focusing on the relationship with dust. That is, in Japanese Patent Application Laid-Open No. Hei 7-21752 (first publicly known document), a magnetic disk and a magnetic head slider are housed in an airtight container that can be decompressed by a vacuum pump, and the pressure in the container is reduced so that the slider and the disk are separated. By creating an environment where contact is likely to occur, and by intentionally mixing desired organic gas and dust from the gas chamber, particle charging chamber and gas generating section into the atmosphere, the deposits on the slider when the head comes into contact with the disk Alternatively, a technique for observing and evaluating the amount of dust with a TV camera or a VTR monitor has been disclosed.

Further, Japanese Patent Application Laid-Open No. 2-76115 (No. 2)
In Japanese Patent Application Laid-Open No. H11-163, there is provided a magnetic head slider and a disk which run relatively to each other, and a wear pin is arranged on the upstream side of the magnetic head with respect to the running direction of the disk so as to contact the disk. A technique of performing a sliding durability test with dust by generating the wear powder and supplying the wear powder between the magnetic head disks is disclosed. JP-A-60-73340 (third known document) discloses an accelerated mechanical durability test between a magnetic head slider and a magnetic disk in a high-concentration dust atmosphere in which cellulose and silicon oxide fine powder are mixed. A technique for evaluating the head crash resistance of a magnetic head slider and a magnetic disk system has been disclosed.

[0005]

As described above, each of the above-mentioned documents discloses an evaluation method which focuses on the influence of dust on the contact sliding durability between the magnetic disk and the magnetic head slider. Before describing the problems of such an evaluation method, the following describes in detail how dust in a magnetic disk device affects the reliability and durability of a head-disk interface (HDI) through the following processes. .

[0006] Dust and contaminants in the magnetic disk drive can be roughly classified into two types. One of them is called primary dust, which is dust and contaminants existing in the materials and components constituting the magnetic disk in advance. For example, a residual component of an organic solvent used for cleaning a part evaporates as an organic gas during operation of the apparatus, and contaminates other parts. Further, dust that cannot be removed in the component cleaning process is separated from the component due to vibration at the time of starting the apparatus or rotating the disk, and contaminates other components. Thus, primary dust depends on the degree of contamination of the initial component material,
The amount of primary dust generally increases sharply during the initial operation of the apparatus, and tends to occur suddenly with a certain period thereafter.

Next, the other dust is called secondary dust, and is dust generated due to sliding contact between the magnetic head and the magnetic slider. That is, mechanical damage occurs at the contact portion due to contact start / stop at the start and stop of the apparatus and intermittent contact sliding at the time of seek operation of the magnetic head, thereby generating abrasion powder. The secondary dust tends to increase in proportion to the operation time of the apparatus, and the film thickness is several 10 nm.
Reflecting the dimensions of the protective film and the lubricating film, the size of the primary dust is smaller than the particle diameter (micron unit) of the primary dust. The amount of dust in the magnetic disk device increases due to the dust generated through the above process.

Next, as a process in which such dust impairs the reliability of the magnetic disk drive, the following phenomena can be mentioned.
That is, the first point is that dust adheres to the head element portion to promote deterioration of the recording / reproducing signal.
This is because the adhesion of dust simply leads to a spatial separation length between the magnetic disk medium and the magnetic head, and the recording / reproducing signal is reduced. A decrease in the playback signal increases errors,
If the number of errors exceeds the reference value, the magnetic disk device will be inoperable. If the dust contains corrosive substances,
The thin film material constituting the head element is corroded, and the quality of the recording / reproduction signal is deteriorated due to the deterioration of the function of the head element. In the worst case, the recording / reproduction becomes impossible.

When the magnetic head element is an MR head based on the magnetoresistive effect, the generation of a noise signal due to the thermal asperity phenomenon peculiar to the MR head element is caused by the adhesion of dust. The thermal asperity phenomenon means that the MR head element contacts the surface of the rotating magnetic disk for some reason,
This is a phenomenon in which a pseudo signal is generated due to a resistance change due to a sudden change in the electric resistance of the MR element due to a rapid temperature rise of the element. This pseudo signal is detected as an error signal, and if the signal exceeds a certain reference value, the magnetic disk device falls into an inoperable state.

The second point is that dust adheres to the air bearing surface of the magnetic head slider, and promotes a change in the flying attitude of the magnetic head slider. That is, when dust adheres to the air bearing surface of the magnetic head slider, the flying attitude of the magnetic head slider changes. The degree of the change depends on the amount of attached dust and the attachment position. The spatial separation length between the head element and the medium increases or decreases depending on the change in the flying attitude, and the reproduction output also changes accordingly. A change in the flying attitude often leads to a decrease in the minimum flying height, which leads to an increase in the contact probability between the magnetic head slider and the surface of the magnetic disk. The increase in the contact probability promotes an increase in the amount of dust generated, and the durability decreases at an accelerated rate in a chain reaction state in which the contact probability increases. Naturally, such a change in the sliding probability leads to the above-described change in the magnetic head output.

As described above, the relationship between the reliability of the magnetic disk drive and the dust must consider not only the flying characteristics of the magnetic head slider such as the flying attitude and the flying height change but also the recording and reproducing characteristics of the magnetic head element. It turns out we have to. There is a problem in that none of the above-mentioned three known documents takes into account the points relating to the recording / reproducing characteristics of the magnetic head.

Next, the problems that the above-mentioned known documents individually have are described below. That is, the reliability evaluation method disclosed in the first publicly known document employs a method of intentionally mixing dust and organic gas in a closed container by providing a particle introduction mechanism and a gas introduction mechanism. It is possible to control the amount of dust introduced. However, it is difficult to control the amount of dust interposed between the head and the disk, and the size of dust that can be introduced (described as particles in the first known document) is generated by actual contact between the head and the disk. It becomes significantly larger than the size of dust, especially secondary dust, and is not sufficient for reliability evaluation of an actual device.

The reliability evaluation method of the second known document is as follows.
A wear pin that slides in contact with the disk is arranged upstream of the magnetic head, and the size of the dust is made to approach the size of the secondary dust by intentionally generating wear powder with the wear pin. However, the contact sliding phenomenon between the wear pin and the disk affects the contact sliding phenomenon between the magnetic head and the disk disposed behind the wear pin. There is a problem that a sliding durability test between the magnetic head and the disk is performed while the separation is unclear.

Further, in the third known document, fine particles of cellulose and silicon oxide are used as dust, and the size (particle size) is not clear, but even if the particle size of the fine particles of cellulose or silicon oxide is small. It is on the order of microns and extremely large for the size of the secondary dust, causing the same problem as in the first known document. Accordingly, an object of the present invention is to comprehensively evaluate and inspect the relationship between the reliability of a magnetic disk device and dust.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an optically transparent disk substrate coated with a thin film, a rotation drive system for rotating the disk substrate, and a disk substrate facing the disk substrate. A magnetic head, a magnetic head slider mounted with the magnetic head, an optical observation system for observing the flying attitude and the flying height of the magnetic head slider through the disk substrate, and a vibration measuring system for measuring the vibration state of the magnetic head slider,
And an electric resistance measuring system for measuring the electric resistance of the head element of the magnetic head. The thin film is formed on the disk substrate with a thickness having optical transparency within a range that does not impair the flying characteristics of the magnetic head slider. The thin film is made of a Co-based magnetic medium thin film, a ferrite-based medium thin film, a carbon-based protective film, an oxide protective film such as SiO ₂ , a carbide protective film such as SiC, and the like, which are materials of a magnetic medium constituting a magnetic disk. It is composed of a lubricating film. In addition, the magnetic head slider is brought into contact with the rotating disk substrate by sliding, so that a thin film is attached from the surface layer of the disk substrate as wear powder to the air bearing surface of the magnetic head slider, and the magnetic head slider flies due to the formation of the attached matter. The attitude and flying height are observed via an optical observation system, the vibration state of the magnetic head slider is measured via a vibration measurement system, and the electric resistance of the head element is measured via an electric resistance measurement system. This is a method for inspecting the magnetic head based on each measurement result.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a magnetic head inspection apparatus according to an embodiment of the present invention. In FIG.
Is an optically transparent disk substrate coated with a thin film 11A, on which a disk is mounted and whose optical transparency is ensured within a range in which flying characteristics of a magnetic head slider described later can be measured. It has a role as a dust source. Reference numeral 12 denotes a motor system for rotating the disk substrate 11, and reference numeral 13 denotes a rotation control system for controlling the rotation speed of the motor system 12.

Reference numeral 14 denotes the above-described magnetic head slider on which a magnetic head is mounted, 15 denotes a seek operation system for performing a positioning operation and seek operation of the magnetic head slider 14 with respect to the disk substrate 11, 16 denotes a seek operation control system, and 17 denotes a seek operation control system. Is an optical system for observing the air bearing surface of the magnetic head slider 14 through the disk substrate 11, 18 is a high-speed video imaging system for recording image information from the optical system 17, and 19 is an optical system 17.
Is a flying height measurement / analysis system that determines the flying height of the magnetic head slider 14 from the image information. Reference numeral 20 denotes a resistance amplifying system for amplifying a change in electric resistance value generated in the magnetic head element due to rotation and sliding of the disk substrate 11, and reference numeral 21 denotes a resistance measurement / analysis system for measuring the amplified change in electric resistance value.

Reference numeral 22 denotes a vibration measurement optical system for measuring the vibration state of the magnetic head slider 14, reference numeral 23 denotes a measurement / analysis system for analyzing the measurement result of the vibration measurement optical system 22, and reference numeral 24 denotes a resistance change measurement result of the magnetic head element. , Magnetic head slider 1
4 is a data analysis system that receives the vibration measurement analysis result, the flying height measurement result of the magnetic head slider 14, the rotation signal of the motor system 12, and the seek signal of the magnetic head slider 14, and comprehensively analyzes these data.

Now, the main parts of the above inspection apparatus will be described more specifically. First, in this embodiment, a tempered glass substrate having a diameter of 3.5 inches is used as the transparent disk substrate 11. Note that a glass substrate such as blue plate glass or quartz glass may be used. In addition, thin film 1
As the material of 1A, a thin film material constituting an actual magnetic disk, for example, a Co (cobalt) -based magnetic medium thin film, a carbon-based protective film, an oxide protective film such as SiO ₂ (silicon oxide), SiC (silicon carbide) It is desirable to use a carbide protective film such as a film and an organic lubricating film.

The motor system 12 is composed of an inverter motor and an air spindle. The motor rotation control system 13 for controlling the motor system 12 has a rotation speed of the inverter motor and a rotation mode (steady rotation at a constant rotation speed). CS that performs mode, contact start / stop operation
(S mode), and outputs a rotation index signal obtained by dividing the circumference of the disk substrate 11 by 1024.
The rotation index signal is an index for confirming in which portion of the disk substrate 11 the flying height variation and the resistance change of the magnetic head element have occurred. As the magnetic head slider 14, a slider on which a magnetoresistive (MR) effect element generally called an MR head is mounted is used.

The seek operation system 15 is a mechanism for moving the magnetic head slider 14 by the voice coil motor in the radial direction of the disk substrate 11, and is controlled by a signal indicating the radial position from the seek operation control system 16. . The optical system 17 and the flying height measurement / analysis system 19 measure the flying height between the disk substrate 11 and the magnetic head slider by an optical interference method. The optical system 17 and the flying height measuring / analyzing system 19 use a flying height measuring device which is commercially available from Fize Metrics Co., USA.

This flying height measuring apparatus irradiates a predetermined measuring point with three laser light beams having different wavelengths,
It has the ability to measure the flying height of the measurement point to a minimum of 10 nm. Then, it is possible to irradiate the entire air bearing surface of the magnetic head slider 14 with white light, and it is possible to measure a state in which the pitch angle and the roll angle of the entire magnetic head slider 14 change due to the formation of the deposit on the air bearing surface. To Further, the high-speed video imaging system 18 records image information relating to the flying state of the magnetic head slider 14 obtained via the optical system 17. Further, the resistance amplification system 20 is an electric circuit that amplifies a change in electric resistance value generated in the head element due to a rise in temperature applied to the head element when the disk substrate 11 and the magnetic head element of the magnetic head slider 14 slide in contact with each other. And a control circuit for controlling the sense current flowing through the head element.

The resistance measurement / analysis system 21 mainly includes an oscilloscope and a personal computer, and measures a change in electric resistance caused by contact sliding of the head element. As the vibration measurement optical system 22 and the vibration measurement / analysis system 23, a laser Doppler vibrometer commercially available from Polytec of the United States is used. This vibrometer can measure the mechanical vibration of the magnetic head slider 14 in a frequency band of 10 KHz to 1 MHz. The data analysis system 24 is mainly composed of a personal computer, and includes rotation information of the disk substrate 11, position information of the disk substrate 11, flying height of the head element of the magnetic head slider 14, vibration information of the magnetic head slider 14, and resistance change of the head element. Input information and analyze them in chronological order.

As described above, the thin film 11A serving as a dust generation source is coated on the optically transparent disk substrate 11 such as glass with a thickness within a range that does not impair optical transparency. Then, the magnetic head slider 14 is brought into contact with the rotating disk substrate 11 so as to slide on the disk substrate 11.
The thin film 11A is removed as wear powder from the surface layer of the magnetic head slider 14, and the wear powder is attached to the air bearing surface of the magnetic head slider 14. Then, the flying attitude of the magnetic head slider 14 due to the formation of the deposits is observed via the optical system 17, and a change in the flying height of the slider 14 due to the formation of the deposits is detected by the flying height measurement / analysis system 19.

The vibration state of the magnetic head slider 14 is measured and analyzed by the vibration measurement optical system 22 and the vibration measurement analysis system. Further, simultaneously with the measurement of the flying attitude and the vibration state of the magnetic head slider 14, the change in the electric resistance of the head element of the magnetic head slider 14 under test is measured by the resistance amplification system 2.
The measurement is continuously performed by the zero and resistance measurement analysis system 21. As a result, the first problem that the conventional problem, that is, the problem relating to the recording / reproducing characteristics of the magnetic head is not taken into account, and that the inspection information relating to the recording / reproducing characteristics cannot be obtained, and the magnetic head and the magnetic disk The second problem is that it is difficult to control the amount of dust interposed between them, and the second problem is that the size of dust that can be introduced is significantly larger than the size of dust (secondary dust) generated by the actual contact phenomenon between the head and the disk. The third problem can be solved.

That is, since the disk substrate 11 is coated with a film thickness in a film thickness region that does not impair optical transparency as a dust generation source, the problem of the method of externally introducing dust (that is, the second problem described above). The control of dust supply between the magnetic head and the disk can be improved. At least, a state close to a contamination phenomenon occurring in an actual magnetic disk device can be reproduced as compared with the external introduction method. The thin film may be made of a thin film material used for a magnetic disk medium, for example, a Co-based magnetic medium thin film, a carbon-based protective film, an oxide protective film such as SiO ₂ ,
By using a carbide protective film such as iC and an organic lubricating film, a state close to an actual contaminated environment in a magnetic disk drive can be reproduced, and the above-mentioned third problem can be solved.

The disk substrate 11 which is a glass substrate
Observing the magnetic head slider 14 using an optical system through the optical disk allows observation of the flying attitude of the magnetic head slider 14 and measurement of the flying height. The flying characteristics observation system using the optical system is suitable for measuring the flying attitude change and the flying height of the entire magnetic head slider 14 which occur for a relatively long time, but has a drawback at a flying height of several tens KHz. It is difficult to measure the posture variation. A vibration measurement system that can measure the mechanical vibration of the magnetic head slider 14 in a frequency band of 10 KHz to 1 MHz compensates for this drawback. And a vibration amount as an integral value thereof or a vibration acceleration as a differential value thereof. As described above, the flying characteristics observation system and the vibration measuring system using the optical system compensate for each other's shortcomings, and can obtain information related to the fluctuation of the flying characteristics of the magnetic head slider 14 in a wide frequency band.

The first problem can be solved by providing a means for measuring a change in electric resistance of the magnetic head element. That is, in this case, it is most desirable to measure the recording / reproducing signal of the magnetic head, but as described above, the thickness of the thin film is limited to a range that does not impair the transparency in order to enable measurement of the flying attitude. For this reason, it is impossible to make a recording / reproducing medium thin film. To solve these problems, the development of the slider's flying characteristics → a change in the contact probability between the disk and the head → a change in the temperature of the head element due to the contact sliding → a change in the electrical resistance of the head element are used to develop the resistance of the head element. By continuously measuring the change in the value, the change in the recording / reproducing signal can be estimated. The resistance change of the magnetic head element can be measured irrespective of the medium configuration of the magnetic disk, that is, whether or not recording and reproduction are possible. As described above, the present inspection apparatus is capable of comprehensively determining and evaluating the relationship between the flying / vibration characteristics of the magnetic head slider and the recording / reproducing characteristics by the optical measurement system.

Hereinafter, the results of actual measurement using the present inspection apparatus will be described in detail with reference to FIGS. On the 3.5-inch tempered glass disk substrate 11, a CoCrTa alloy film and a carbon film are sequentially formed to a thickness of 1 nm and a carbon film by a sputtering method, and a perfluoropolyether. Diol (PFPE
-DIOL) formed by spin coating to a thickness of 1 nm. Such a film configuration is the result of selecting a film configuration close to the actual film configuration of the magnetic disk without impairing the optical transparency.

As the magnetic head slider 14, FIG.
A center pad type 50% negative pressure slider having an air bearing surface shape as shown in FIG. Here, in the figure, 14A and 14B are air bearing surfaces,
14C indicates a negative pressure generating unit. The reproducing head mounted on the magnetic head slider 14 is an MR head to which a magnetoresistive element made of a NiMn thin film is applied, and is provided on a center pad (the air bearing surface 14 in FIG. 2).
B part 14D).

When the air bearing surface is normal as shown in FIG. 2B, the flying height of the MR head element portion of the magnetic head slider 14 (substantially coincides with the flying height of the magnetic head slider 14) is 30 nm. . This magnetic head slider 1
4, the disk substrate 11 was rotated at 5400 rpm.
2, even if the magnetic head slider 14 flies with the minimum flying height of 30 nm on average, the slider 14 and the disk substrate 11 intermittently contact and slide due to instantaneous flying fluctuation. As shown in (c), the air bearing surface of the slider 14 is gradually contaminated, and deposits made of a thin film material formed on the surface of the disk substrate 11 are formed.

With the formation of the deposits, the flying height of the MR head element changes. FIG. 3 shows a continuous measurement result of the change in the flying height of the MR head element portion, the amplitude value of the mechanical vibration of the magnetic head slider 14, and the change in the electric resistance of the MR head element. From this measurement result, it can be seen that the formation of deposits on the air bearing surface of the slider 14 generally lowers the flying height of the MR head element portion (FIG. 3A).
(4) amplifying the mechanical vibration of the whole (FIG. 3 (b));
Further, it can be seen that the electric resistance of the MR head element portion is varied (FIG. 3C).

Further, as the contamination state of the air bearing surface of the slider 14 progresses and the state of FIG. 2C shifts to the state of FIG. 2D, as shown in the measurement results of FIG. The pitch angle changes (FIG. 4B), the flying height of the MR head element portion (FIG. 4A), and the amplitude value of the mechanical vibration of the magnetic head slider (FIG. 4C) changes. Here, when the pitch angle changes (that is, the flying attitude of the entire slider 14 changes), the position of the minimum flying height moves from the MR head element portion to the center of the air bearing surface, and the flying height of the MR head element portion changes. Is slightly increased due to the crown shape of the magnetic head slider 14, so that the MR head element portion does not directly contact and slide on the disk substrate 11. For this reason, FIG.
As shown in (d), the electric resistance value of the MR head element portion does not change. However, since the slider slides on the air bearing surface of the slider, the mechanical vibration of the entire slider is amplified as shown in FIG.

As described above, the present inspection apparatus is one of the factors governing the mechanical durability and the recording / reproducing characteristics of the magnetic disk drive.
Magnetic head slider 14 resulting from the formation of deposits
For the change in the flying attitude, a comprehensive evaluation was made possible by measuring the change in the flying height, the vibration state of the entire slider, and the electric resistance value of the magnetic head element. As a result, the magnetic head slider 1
4 and the shape of the magnetic head slider 14 can be optimized.

[0035]

As described above, according to the present invention, an optically transparent disk substrate coated with a thin film, a rotation drive system for rotating the disk substrate, and a magnetic disk disposed facing the disk substrate. A head, an optical observation system for observing the flying attitude and flying height of a magnetic head slider equipped with a magnetic head through a disk substrate, a vibration measuring system for measuring a vibration state of the magnetic head slider, and an electric resistance of a head element of the magnetic head. And a magnetic head slider is brought into contact with the rotating disk substrate to slide the thin film from the surface layer of the disk substrate as abrasion powder on the air bearing surface of the magnetic head slider. The flying attitude and the flying height of the magnetic head slider accompanying the formation of the kimono are observed through an optical observation system, and the vibration of the magnetic head slider is measured. The state was measured through the vibration measurement system,
In addition, since the electric resistance of the head element is measured via an electric resistance measuring system and the magnetic head is inspected based on the results of these measurements, the mechanical durability and recording / reproducing characteristics of the magnetic disk device are controlled. A change in the flying attitude of the magnetic head slider, which is one of the factors, due to the formation of deposits, can be comprehensively evaluated. As a result, the overall evaluation results can be used to judge the quality of the magnetic head slider, It is possible to optimize the shape of the head slider. In addition, since the thin film is formed on the disk substrate with a thickness having optical transparency within a range that does not impair the flying characteristics of the magnetic head slider, the flying characteristics of the magnetic head slider can be accurately measured. The thin film is made of a Co-based magnetic medium thin film, a ferrite-based medium thin film, a carbon-based protective film, which is a material of a magnetic medium constituting a magnetic disk.
Oxide protective film such as SiO ₂ , carbide protective film such as SiC,
Further, since the magnetic head slider is constituted by the organic lubricating film, the magnetic head slider can be inspected by reproducing a state close to a contaminated environment in an actual magnetic disk device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a magnetic head inspection apparatus according to the present invention.

FIG. 2 is a diagram showing a configuration of a magnetic head slider (FIG. 2)
(A)) and photographs ((b) to (b)) showing the state of change in the contamination state of the magnetic head slider evaluated using the inspection apparatus as a state of a halftone image displayed on a display.
(D)).

FIG. 3 shows a change in the flying height of the MR head element portion due to a change in the contamination state of the magnetic head slider, a vibration amplitude value of mechanical vibration of the magnetic head slider,
FIG. 7 is a diagram showing a result of continuous measurement of a change in electric resistance of an MR head element.

FIG. 4 shows a change in the flying height of the MR head element, a pitch angle of the magnetic head slider, a vibration amplitude value of mechanical vibration, and a vibration amplitude of the MR head element due to a change in the contamination state of the magnetic head slider evaluated using the inspection apparatus. It is a figure showing the continuous measurement result of electric resistance value change.

[Explanation of symbols]

11: disk substrate, 11A: thin film, 12: motor system,
13: motor rotation control system, 14: magnetic head slider,
15: seek operation system, 16: seek operation control system, 17:
Optical system, 18: High-speed video imaging system, 19: Measurement of flying height
Analysis system, 20: Resistance amplification system, 21: Resistance measurement / analysis system,
22: Vibration measurement optical system, 23: Vibration measurement / analysis system, 24
... Data analysis system.

Claims (6)

[Claims] 1. An optically transparent disk substrate coated with a thin film, a rotation drive system for rotating the disk substrate, a magnetic head arranged facing the disk substrate, and a magnetic head mounted with the magnetic head An optical observation system for observing the flying attitude and flying height of the slider through the disk substrate, a vibration measuring system for measuring the vibration state of the magnetic head slider,
An inspection apparatus for a magnetic head, comprising: an electric resistance measuring system for measuring an electric resistance of a head element of the magnetic head. 2. The magnetic head inspection apparatus according to claim 1, wherein the thin film is formed on the disk substrate with a thickness having optical transparency within a range that does not impair the flying characteristics of the magnetic head slider. . 3. The thin film according to claim 1, wherein the thin film is a Co-based magnetic medium thin film, a ferrite-based medium thin film, a carbon-based protective film, an oxide protective film such as SiO ₂ , which is a material of a magnetic medium constituting a magnetic disk; An inspection apparatus for a magnetic head, comprising a carbide protective film such as SiC and an organic lubricating film. 4. An optically transparent disk substrate coated with a thin film, a rotation drive system for rotating the disk substrate, a magnetic head disposed facing the disk substrate, and a magnetic head mounted with the magnetic head An optical observation system for observing the flying attitude and flying height of the slider through the disk substrate, a vibration measuring system for measuring the vibration state of the magnetic head slider,
An electric resistance measuring system for measuring the electric resistance of the head element of the magnetic head, and by contacting and sliding the magnetic head slider against the rotating disk substrate, the thin film from the surface layer of the disk substrate is turned into wear powder to produce a magnetic head slider. The magnetic head slider is attached to the air bearing surface, and the flying attitude and the flying height of the magnetic head slider accompanying the attached matter are observed through an optical observation system, and the vibration state of the magnetic head slider is measured through a vibration measuring system, and A method for inspecting a magnetic head, comprising: measuring an electric resistance of a head element via an electric resistance measuring system; and performing an inspection of the magnetic head based on each measurement result. 5. The magnetic head inspection method according to claim 4, wherein the thin film is formed on the disk substrate with a thickness having optical transparency within a range that does not impair the flying characteristics of the magnetic head slider. . 6. The thin film according to claim 4, wherein the thin film is a Co-based magnetic medium thin film, a ferrite-based medium thin film, a carbon-based protective film, an oxide protective film such as SiO ₂ , which is a material of a magnetic medium constituting a magnetic disk; A method for inspecting a magnetic head, comprising: a carbide protective film such as SiC; and an organic lubricating film.