JPS58113869A - Inspecting apparatus for medium of magnetic record - Google Patents

Abstract

PURPOSE:To increase the efficiency of manufacturing and inspecting processes by performing a varnishing process for a medium of magnetic record and a floatation inspecting process therefor as one process. CONSTITUTION:The output of a detecting means 14 amplified by a preamplifier 22 passes through a filter circuit 31 and is given to a comparison circuit 32. The output of the comparison circuit 32 controls a carriage driving control circuit 34, a spindle motor driving control circuit 35 and the brake circuit 36 of a motor 5. When a floatation inspecting head slider 18 is moved in the direction of the radius of a disc 1 and a projection on the disc 1 is detected by the detecting means, a carriage driving motor 16 and a driving motor for spindle are stopped at the position, and the floatation inspecting head slider touches the disc slidably and removes the projection. Thereafter, the spindle driving motor 5 is restarted while monitoring is made by a rotation speed monitoring circuit 37, and this operation is repeated until the output from the detecting means 14 disappears. By this constitution, the inspection and varnishing are performed simultaneously, and thus the efficiency is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a flying test device for a magnetic recording medium, and more particularly to a device for testing the flying properties of a magnetic recording medium using a flying test head.

(2) Background of the technology In order to test the quality of magnetic recording media such as magnetic disks, tests are performed to see if the floating magnetic head is in a normal state. After applying a magnetic medium to the disc and performing baking, burnishing is performed. This vanishing uses an alumina slider or the like to levitate a head with a low flying height with a certain amount of spring pressure on a magnetic disc, move it in the radial direction between the outer and inner peripheries of the disc, and move the disc at 1000 to 3000 r. ,
It is made to rotate at p and m.

Such a burnishing process can remove minute protrusions, dust, etc. from the disk surface.

After performing such a burnishing process, in order to inspect whether the disk can be used without problems with the head used in the device, it is necessary to install an AE element or piezoelectric It was equipped with elements to inspect the contact between the magnetic disk and the inspection head, as well as its buoyancy.

For this reason, two processes, the baninosh process and the magnetic disk floating/inspection process, have to be performed separately, which is complicated.
Furthermore, there has been a problem in that the defective rate in the disk buoyancy inspection process increases due to dust that adheres to the magnetic disk between the burnishing process and the buoyancy inspection process.

(3) Prior art and problems Figure 1 shows the process of a conventional magnetic recording medium levitation inspection device. The disk is rotated and moved back and forth in this direction to remove any protrusions or attached dust on the surface of the disk. FIG. 2(a) is a measured curve C1 showing the surface condition in a predetermined range before burnishing, and after burnishing, a considerable improvement is seen as shown in measured curve C2 in FIG. 2(b). For example, the number of touches with the floating inspection head before the vanish was 47, but after 3 reciprocations of the vanish, it became 15, and after 10 reciprocations, it became 5. After the burnishing process using such a burnish head, the flying test head, which has a smaller flying height than the magnetic head actually used in the product (the flying height is larger than the vanishing head), is inspected using a detection means such as an AE element or a piezoelectric element to check the flying properties. Perform inspection. Baninosh process FP described above
When the vanish head was reciprocated three times in the radial direction of the magnetic disk, the number of contacts between the head and the disk surface was 15 when the levitation test was performed immediately. The number of contacts for row 7 has increased to 37.

That is, the defect rate of the disks to be inspected is increasing with the passage of time. This is thought to be because dust adhered to the surface of the magnetic medium of the disk after burnishing.

(4) Object of the Invention In view of the above-mentioned conventional drawbacks, the first object of the present invention is to improve the efficiency of the manufacturing inspection process by performing the burnishing process and the flotability inspection process at the same time.

Another object of the present invention is to reduce noise from the burnish head to the contact detection element of the head mounted on the flying height -5 = = 4- head, which is produced by integrating the burnishing process and the flying property inspection process. It also provides a means of preventing transmission.

Still another object of the present invention is to perform C3S (start/stop control) when the flying test head detects contact in the flying test process to bring the flying test head into contact with the magnetic disk and remove the contact portion. It was designed so that

(5) Structure of the Invention An object of the present invention is to provide a magnetic recording medium inspection apparatus for inspecting whether or not a magnetic recording medium is capable of stably flying a head having a predetermined flying height. A flying inspection head having a lower flying height than the head and having a detection means for detecting a protrusion of the magnetic recording medium, and one or more vanish heads having a lower flying height than the flying testing head are disposed on one arm. This is achieved by providing a magnetic recording medium levitation inspection apparatus characterized by:

(6) Embodiment of the Invention Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. Figure 3 is a side view and a system diagram of the magnetic recording medium float inspection device of the present invention, and Figure 4 is a side view and its system diagram. 3 is an enlarged view of section A in FIG. 3, in which reference numeral 1 indicates a magnetic disk serving as a magnetic recording medium, which is fixed to a turntable 3 on a spindle 2 by a clamp 4.

The spindle 2 is rotatably pivoted to the base 9 of the casing, and has a pulley 6 fixed to the shaft of the drive motor 5 and the spindle.
．． During the period 7, the hook is rotated via a belt 8 that is passed over the space. 1
0 is a shroud surrounding the disk 1 to prevent the vanished magnetic powder from scattering and to prevent dust from entering from the outside.

Two rails 11 are arranged on the base 9, a carriage 12 is slidably rolled onto the rails, and an arm 14 is fixed to an arm holder 13 provided on the carriage. There is a gimbal 15 at the tip as shown in Figure 4.
and is fixed to the arm 14 with screws 19 or the like. 1゛□ The gimbal 15 has a slider holding part 15b at the tip and a spring part 15a for pressing the head slider 18 with a constant pressure toward the surface of the disk 1 in the =7- direction.
Constructed from a spring plate with great spring characteristics.

18. 18' is the hemlock slider with air passage groove 20°20
', and the head slider has a substantially concave cross section.

In the present invention, a vanish gimbal and a floating test gimbal 15 are attached to one arm 14. At this time, as shown in FIG. 5, the navel slider 18 for vanishing
The flying height of ' is 11 from the surface of disk 1, the floating amount of slider 18 is 12 from the surface of disk 1,
Assuming that the amount of levitation of the slider 18'' attached to an actual magnetic recording device is 13, the respective levitation amounts are selected in the relationship I+<12<13.

Furthermore, since the linear velocity differs between the inner and outer circumferences of the disk 1, the flying height of each of the head sliders can be selected so as to linearly increase the flying height from the inner circumference toward the outer circumference.

In FIG. 3, the carriage 12 is configured to be slid by a carriage drive motor 16 in the radial direction of the disk 1 from the inner circumference to the outer circumference or from the outer circumference to the inner circumference. Reference numeral 17 is a screw rod for sliding the carriage 12.

When the carriage 12 is slid in the radial direction of the disk, the disk 1
Since it is rotated at approximately 300 Or, p, m, it is of course that it floats an appropriate distance 11 or 12 above the disk surface.

In the present invention, a detection means 21 such as an AE element or a piezoelectric element for detecting acceleration is provided at the base of the gimbal 15 of the flying inspection head (head slider 18). The detection means detects the smiling protrusion of the magnetic 1- coated on the disc 1, and if the detection signal is amplified by the preamplifier 22 and displayed on a synchroscope 23 or the like, contact of the disc 1 can be observed.

In the case of the above configuration, that is, in order to perform the burnishing process and the floating inspection process at the same time by attaching the vanishing navel slider 18' and the floating inspection head slider 18 to one arm 14, as shown in FIG. The slider is moved from the outermost circumference O8 to the burnish in the innermost circumference IB force direction, and then moved from the inner circumference to the outer circumference, and after repeating this burnishing process 24 several times, from the innermost circumference to the outer circumference 9-8- At the time of the final movement towards the end 25, the inspection can be carried out by operating the slider 18 for inspection. Like this above 16
In this example, alumina is used for the vanish slider, but instead of using a gimbal 15 for mounting the head as shown in FIG. 26, the pressing force is selected to be several hundred grams, and a polishing tape (3 to 9 μm particles) 27 is attached to the tip of the leaf spring 26. In the case of such a vanish head, seizure is likely to occur, so the rotation speed of the spindle should be adjusted to 1000 to 1500 r, p,
m.

should be selected. In this way, when the burnishing process and the flotation test are performed at the same time, the shock vibrations generated when the head sliders 18', 27, etc. of the burnishing -10- come into contact with the protrusion of the disk 1 are placed on the flotation test head 18. There is a problem in that this is transmitted to the detecting element 21 which is being used, and reduces the reliability of pass/fail determination.

For this purpose, the inventor has developed a hent slider 18 for vanishing.
A cushioning material 28 such as adhesive tape is attached to the gimbal 15 of Installation is gimbal 1
A similar cushioning material 30 is also provided between the arm 14 and the arm 14. Furthermore, a washer-like cushioning material is interposed between the male screw or the female screw for attaching the RAD slider or gimbal to the vanish, if necessary.

Table 2 shows the results of comparing the effect of inserting such a cushioning material with that of Comparative Example (A) under the following conditions.

First, the following conditions were selected with the head slider for floating inspection not in contact with the disk 1.

(a) When the hent slider for levitation inspection and the vanish rad slider are attached to one arm and no cushioning material is provided. Attaching is possible when a cushioning material is provided to the object (c) when a cushioning material such as adhesive tape is attached to the gimbal of the vanish head slider (d) when (b) and (c) are combined. This makes it possible to prevent the high frequency vibrations applied to the cymbal from the Vanish Rad Slider and to significantly reduce the high frequency noise applied to the detection means from the Vanish Rad Slider's gimbal through the arm.

Still another embodiment of the present invention will be described with reference to a system diagram shown within the broken line in FIG. In this case, the head for vanish,
The head for flying height inspection can be used in combination, and it is possible to perform vanishing and flying height testing at the same time. The output of the detection means 14, which is amplified by -19- from the preamplifier 22 within the dashed line, is applied to the comparator circuit 32 through the filter circuit 31. A plus or minus slice reference level is applied to the comparator circuit 32 from a reference circuit 33, and is compared with the detection output from the comparator circuit 32.

The carriage drive control circuit 3 uses the output from the comparison circuit 32.
4. Spindle motor drive control circuit 35 and motor 5
The brake circuit 36 is controlled to drive the spindle drive motor 5 and carriage drive motor 16.

That is, for the levitation inspection, the rad slider 18 is moved in the radial direction of the disk 1, and the carriage drive motor 16 and the spindle drive motor are stopped at the position where the protrusion on the disk 1 is detected by the detection means. The Herad slider slides into contact with the disc and acts to remove the protrusion.

Next, when the restart circuit 38 is operated while the spindle rotation speed monitor circuit 37 monitors the spindle drive motor 5, the levitation inspection hent slider 8 floats again. When the output from the detection means 14 disappears after repeating this operation several times, the carriage drive motor 16 is restarted.

Note that if the output from the detection means does not disappear even after repeating the C5S (start/stop control) described above several times, the disk may be determined to be defective. In this way, the inspection and vanishing were done at the same time,
In particular, there is no need to provide a helad slider for vanishing (
Become.

(7) Effects of the Invention As described above in detail, the magnetic recording medium flotation inspection apparatus of the present invention can perform the baninosh process and the flotation inspection process simultaneously, and can also cause defects in magnetic recording media due to adhesion of dust. In addition to reducing the detection rate, even if a vanish head slider and a rad slider are fixed to one arm, the detection output is hardly affected due to the effect of the cushioning material, and CC8 is performed on the contact area. This has the advantage that vanishing and floating inspections can be performed at the same time.

[Brief explanation of the drawing]

FIG. 1 is a process explanatory diagram of a conventional magnetic recording medium inspection device.
Figure 2 (a) is a curve diagram showing the uneven state of the magnetic medium surface when the burnishing process of a conventional magnetic recording medium inspection device is not performed, and Figure 2 (b) is a curve diagram showing the same condition after the burnishing process. 3 is a system diagram and a route diagram of the mechanical part of the magnetic recording medium levitation inspection apparatus of the present invention, FIG. 4 is an enlarged plan view of section A in FIG. 3, and FIG. FIG. 6 is an explanatory view showing the burnishing process and the floating inspection device, and FIG. 7 is a perspective view showing another embodiment of the burnishing head used in the present invention. 1... Magnetic recording medium (magnetic disk), 2... Spindle, 3... Turntable, 4... Clamp, 5...
... Drive motor, 6, 7... Boo IJ, 8... Belt, 9... Base, 10... Shroud, 11...
・Rail, 12... Carriage, 13... Arm holder, 14... Arm, 15... Gimbal, 15a
...Spring part, 15b...Slider holding part, 1
6... Carriage drive motor, 17... Screw rod, 18
．． 18', 18"...Head slider, 20.20'
... Air passage groove, 21 ... Detection means, 22 ... Preamplifier, 23 ... Synchro scope, 26 ... Leaf spring, 27 ... Polish tape, 2B, 29.30.
...Buffer material, 3 parts...Filtering circuit, 32...Comparison circuit, 33...Reference circuit, 34...Carriage drive control circuit, 35...Spindle motor drive control circuit. Sun tile me U) Q) (K) c.

Claims (9)

[Claims] (1) In a magnetic recording medium inspection device for inspecting whether a head with a predetermined flying height is a magnetic recording medium that flies stably, a head with a lower flying height than a head with a predetermined flying height , characterized in that one or more of a flying inspection head having a detection means for detecting irregularities of the magnetic recording medium and a vanishing head having a lower flying height than the flying inspection head are disposed on one arm. A floating inspection device for magnetic recording media. (2) A floating inspection device for a magnetic recording medium according to claim 1, wherein alumina is used for a slider as the burnish head. (3) A floating inspection device for a magnetic recording medium according to claim 1, wherein a polishing tape is attached to a plate spring as the vanish head. (4) A floating inspection device for a magnetic recording medium according to claim 1, wherein a buffer member such as an adhesive tape is attached to the gimbal of the vanish head. (5) A floating inspection device for a magnetic recording medium according to claim 3, wherein a buffer member such as an adhesive tape is attached to the leaf spring of the vanish head. (6) A floating magnetic recording medium according to claim 3, wherein a tape is attached to the vanish head and attached to a plate spring, and a buffer member such as rubber is disposed between the plate spring and the arm. Inspection equipment. (7) A floating inspection device for a magnetic recording medium according to claim 1, wherein a cushioning member such as rubber is disposed between the arm and the gimbal to which the vanish head is attached. (8) The magnetic recording medium floating inspection device according to claim 1, wherein a buffer member such as rubber is disposed between the floating inspection head and the arm. (9) The magnetism according to claim 1, wherein the rotation of the magnetic recording medium is temporarily stopped and then restarted depending on the output of a detection means for detecting irregularities of the magnetic recording medium. Levitation inspection device for recording media.