JP2598698B2 - Magnetic head tester - Google Patents

Description

The present invention relates to a magnetic head tester, and more particularly, to a magnetic head tester.
The present invention relates to a magnetic head tester that requires a short time to inspect a magnetic head used such as a hard magnetic disk.

2. Description of the Related Art Conventional magnetic head testers include a test device for measuring a flying height of a magnetic head, which is a physical characteristic, and a test device for measuring an electromagnetic conversion characteristic, which is an electrical characteristic. There are types.

Usually, the characteristics of the magnetic head are inspected by these two types of measuring devices. In general, first, the flying characteristics of the magnetic head are measured, and then the electromagnetic conversion characteristics of the acceptable products are measured.

[Problem to be Solved] Therefore, in order to test the magnetic head, it is necessary to mount the magnetic head on each of two test devices, and it takes time and effort to mount and remove the magnetic head.
It is necessary to manage the magnetic head with respect to one of the measurement results, and it takes a lot of time to test one magnetic head.

On the other hand, in recent years, hard magnetic disk devices have been demanded for higher density recording than before, and are required to ensure high reliability. Accuracy is also getting higher. Therefore, the overall throughput of the magnetic head inspection tends to decrease. For this reason, when different tests are performed by the two test devices as described above, it takes time to mount the magnetic head and to remove the magnetic head in this case, and furthermore, the influence of the mounting state on the test results. Which is also a factor that reduces the yield.

The present invention solves such problems of the prior art, and can measure head flying characteristics and electromagnetic conversion characteristics with a single test device, and can improve measurement efficiency. An object of the present invention is to provide a magnetic head tester.

Means for Solving the Problems The configuration of the magnetic head tester of the present invention for achieving the above object includes a first disk for measuring the flying characteristics of the magnetic head, and an electric drive for the magnetic head. A second disk for measuring a characteristic, a measurement position provided between the first and second disks, wherein one of the first and second disks is selectively positioned, and a measurement position opposite to the measurement position. And a carriage mounted with a magnetic head to be tested for accessing each of the first and second disks selectively positioned at the measurement position, and measuring the flying characteristics. Sometimes, the first disk is positioned at the measurement position, and when measuring electrical characteristics, the second disk is positioned at the measurement position.

[Operation] As described above, the disk for measuring the flying height and the disk for measuring the electrical characteristics are juxtaposed, a measurement position is provided therebetween, and one carriage is placed at the measurement position. Since the disks are provided so as to face each other and are selectively positioned at this measurement position, there is no need to attach / detach a magnetic head to be tested for each measurement. It is not necessary to drive and stop the motors related to the mechanism, and to start and control each test device and related circuits independently, and to test each data of the flying characteristics and electromagnetic conversion characteristics of the magnetic head. It can be easily obtained for a magnetic head.

As a result, the time required to perform each measurement can be reduced, the head flying characteristics and the electromagnetic conversion characteristics can be measured in a short time with one test apparatus, and the measurement efficiency of the entire measurement process can be improved. .

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view of an embodiment to which the magnetic head tester of the present invention is applied, and FIG. 2 is a detailed view of a platen portion thereof.

In FIG. 1, reference numeral 20 denotes a magnetic head tester, reference numeral 21 denotes a measurement mechanism unit, and reference numeral 22 denotes a measurement control / data processing unit, which includes a microprocessor, a memory, and the like.

Reference numeral 1 denotes a surface table provided with a measuring mechanism 21. On the surface table 1, a glass disk 2 for measuring a floating characteristic is fixed to a spindle 2a as shown on the right side of the drawing. A magnetic disk 4 (hard disk) for measuring electromagnetic conversion characteristics is fixed to a spindle 4a as seen on the left side of the drawing. Further, between the glass disk 2 and the magnetic disk 4, a measurement position (refer to a position indicated by a dashed line in the center of the drawing) 3 at which the disks are selectively positioned is provided.

Reference numeral 23 shown by a dotted line denotes an optical system for measuring the flying height, which is disposed above the measuring position 3 and receives reflected light by irradiating a laser beam or a normal light beam to the glass disk 2. Is set at the measurement position 3, the distance between the glass disk 2 and the magnetic head 9 in the loaded state is measured,
The measurement result is converted into an electric signal and transmitted to the measurement control / data processing unit 22.

An air cylinder 5 indicated by a dotted line is an air cylinder that moves the glass disk 2 to the measurement position 3 and returns the glass disk 2 to the original position. The air cylinder is provided below the platen table 1, and the tip of the moving rod moves to the spindle 2a. Are combined. Similarly, reference numeral 6 indicated by a dotted line denotes an air cylinder which moves the magnetic disk 4 to the measurement position 3 and returns it to the original position. It is connected to the spindle 4a. In order to allow this movement, the table 1 has spindles 2a, 4
A linear opening is provided so that a can be moved to the measurement position 3. By driving these air cylinders 5 and 6 at the leading end, the glass disk 2 and the magnetic disk 4 are selectively positioned at the measurement position. No. 3.

When the spindle 2a and the spindle 4a are respectively positioned at the measurement positions, they are coupled to the same drive motor, and the measurement control / data processing unit 22 is used for each measurement.
Is rotationally driven in response to a control signal from the controller.

The carriage 7 is placed and arranged on an XY table fixed on the surface table 1 so as to face the measurement position 3.
Its position can be fine-tuned. Then, the magnetic head 9 mounted on the carriage 7 is moved forward and backward to access the glass disk 2 and the magnetic disk 4 arranged at the measurement position 3 in common.

Reference numeral 8 denotes a platen which is positioned at an accurate position on the carriage 7 by a claw mechanism, a screw, or the like, and is detachably fixed to the platen. As shown in FIG. Is mounted. As can be seen from FIG. 2 showing this state, the magnetic head 9 is detachably fixed to the holder 10 on the platen 8.

The holder 10 includes a right-angle hook-shaped fixing member 11 having two sides in a right angle direction serving as a guide and a stopper, and two positioning pins 12 and 12 provided therein. By moving back and forth in the direction of 45 degrees, the rectangular member 9a at the base of the magnetic head 9 is brought into contact with each side at a right angle, and abutting in the XY direction is performed, so that the two positioning pins 12, 1
Positioning is fixed between the two. Note that positioning pin 1
The magnetic heads 2 and 12 are positioned in a more accurate position on the platen 8 by being fitted into two positioning holes provided in the rectangular member 9a at the base of the magnetic head 9, respectively.

Reference numeral 13 denotes a paddle, which has contact stripes 13a and 13b with which the probe contacts, and the lead wire 9b of the magnetic head 9 is connected to the contact stripes 13a and 13b. This is, for example, a small ceramic substrate, which is mounted on a box-shaped paddle guide 14 having an open end provided on the platen 8 and having rotating claws 15, 15 from both sides.
It is detachably fixed by the rotation of.

Therefore, when the magnetic head 9 to be tested is mounted on the holder 10, the lead wire 9b of the magnetic head 9 is connected to the paddle 13, so that the probe 16 is connected to the contact stripes 13a, 13b provided on the paddle 13. (See FIG. 1) is contacted and connected to a read / write amplifier (R / W amplifier) 19 arranged on the table 1. Thus, the magnetic head 9 is connected via the read / write amplifier 19 to the electric circuit of the measurement control / data processing unit 22 arranged below the table 1.

17a, 17b, 17c, 17d, 17e, respectively, for example, a photo interrupter, a position detection sensor such as a photo sensor,
The detection of detection pieces, holes, and the like provided on the carriage 7, the spindles 2a, 4a, and the like is performed to detect that they are at the reference positioning position. Sent to 22.

That is, the position detection sensor 17a is provided at the rear portion of the carriage 7, and detects that the carriage 7 is at the reference position in the Y direction of the carriage 7 (the direction perpendicular to the moving direction of the two disks). The position detection sensor 17b is connected to the carriage 7 and the measurement position 3 on the side opposite to the position detection sensor 17a.
, And detects that the magnetic disk 4 (its spindle 4a) is positioned at the reference position of the measurement position 3 at the reference position of the measurement position 3. At this time, the carriage 7 and the magnetic disk 4 are arranged to face each other, and the center line of the magnetic head 9 is aligned with the magnetic disk 4.
, And the carriage 7 becomes the carriage of the magnetic disk 4. The position detection sensor 17c is arranged at substantially the same position as the position detection sensor 17b, and detects that the glass disk 2 (its spindle 4a) is positioned at the reference position of the measurement position 3 at the reference position of the measurement position 3. At this time, the carriage 7 and the glass disk 2 are arranged to face each other, the center line of the magnetic head 9 coincides with the rotation center of the glass disk 2, and the carriage 7 becomes the carriage of the glass disk 2. The position detection sensors 17d and 17e
It is detected that the glass disk 2 and the magnetic disk 4 are positioned at the initial positions (disk positions indicated by solid lines in the drawing).

Reference numeral 18 denotes a head loading mechanism for the magnetic head 9 mounted on the carriage 7. As described above, the read / write amplifier 19 for amplifying the electric signal from the magnetic head 9 is adjacent to the head loading mechanism 18. It is arranged.

Next, the operation will be described.
Are usually arranged on a pallet or the like and are placed separately from the magnetic head tester 20. One of them is first mounted on the holder 10 of the platen 8 and mounted. The platen 8 on which the magnetic head 9 is mounted is positioned at a predetermined position provided on the carriage 7 and mounted on the carriage 7. If the magnetic head 9 can be replaced by making the platen 8 an independent unit as described above, even if the shape and form of the magnetic head 9 change, the platen 8 and the magnetic head 9 can be replaced.
It is only necessary to change the mounting relationship with the device, and no modification on the device side is required.

First, the measurement control / data processing unit 22 checks whether or not the carriage 7 is at the measurement reference position based on the output of the position detection sensor 17a, and drives the air cylinder 5. As a result, the air cylinder 5 is driven according to the control signal from the measurement control / data processing unit 22, the rod advances, and the glass disk 2 moves to the measurement position 3 and is positioned at the measurement position 3. Note that a stopper or the like may be provided for the movement of the air cylinder 5 for this positioning.

The detection of the positioning position in this case is performed by determining the signal of each position detection sensor by the measurement control / data processing unit 22. At this time, the position detection sensor 17e for the magnetic disk 4 is turned on. In the state where the magnetic disk 4 is at the initial position,
This is because 17c is turned “ON”.

When the positioning of the glass disk 2 at the measurement position 3 is completed, the measurement of the flying height is started. First, the measurement control / data processing unit 22 checks whether or not the carriage 7 is at a regular position by a signal of the position detection sensor 17a, drives the carriage 7, and moves the carriage 7 in the direction of the spindle 2a which is the center of the glass disk 2. The magnetic head 9 is moved toward. Then, the magnetic head 9 is loaded on the glass disk 2 by the head loading mechanism 18, and the glass disk 2 is driven to rotate. Here, the magnetic head 9 flies. Note that this is an example of a contact start / stop,
The glass disk 2 may be rotated before head loading.

Next, the measurement control / data processing unit 22 controls the carriage 7
Is controlled, and the magnetic head 9 moves to a predetermined measurement point which is a light irradiation point of the optical system 23 for measuring the flying height. At this position, the flying height is measured by the flying height measuring optical system 23, and the measurement is performed by the measurement control / data processing unit.
22 are stored in the memory corresponding to the data of the magnetic head. If the flying height measurement results in a failure, the platen 8 is removed from the carriage 7, the magnetic head 9 is removed from the platen, and the magnetic head 9 to be tested next is removed.
Is mounted on the platen 8, and the next magnetic head test is performed in the same manner as described above.

When the measurement of the flying height is completed, the carriage 7 returns to the initial position, which is the original reference position. Next, the air cylinder 5 is driven, the rod is retracted, and the glass disk 2 is returned to the initial position indicated by the solid line. Then, the process proceeds to the measurement of the electromagnetic conversion characteristics. First, the air cylinder 6 is driven in accordance with a control signal from the measurement control / data processing unit 22, the rod advances, and the magnetic disk 4 moves to the measurement position 3 and is positioned at the measurement position 3. . As described above, a stopper or the like for the movement of the air cylinder 6 may be provided for this positioning. In this case, the position detection sensor 17d for the glass disk 2 is in the “ON” state, and when the glass disk 2 is in the initial position, the position detection sensor 17b is set to “O”.
Then, the carriage 7 is controlled by the control signal from the measurement control / data processing unit 22 to move the magnetic head 9 toward the spindle 4a which is the center of the magnetic disk 4. Then, the magnetic head 9 is loaded on the magnetic disk 4 by the head loading mechanism 18 and the magnetic disk 4 is driven to rotate, which is also the case of contact start / stop.
As described above, the carriage 7 is controlled by the measurement control / data processing unit 22, and the magnetic head 9 is moved to a predetermined track position for measuring the electrical characteristics, where the read / write (R / W) test is performed. Is performed.

In the R / W test, the probe 16 comes into contact with the contact provided on the paddle with the magnetic head 9 positioned at a predetermined track position, and the electrical output of the magnetic head 9 is changed to the paddle 13, the probe 16, and the lead. A signal is sent to the measurement control / data processing section 22 via the write amplifier 19, and the signal is sent to the measurement control / data processing section 22 for analysis. This is performed by storing the data in a memory corresponding to the data. As in the case of the flying height measurement, if the result of the electromagnetic conversion characteristic measurement is unacceptable, the platen 8 is removed from the carriage 7, the magnetic head 9 is removed from the platen, and The magnetic head 9 is mounted on the platen 8 and the next magnetic head test is performed in the same manner as described above.

In this way, when the measurement of the flying height and the measurement of the electromagnetic conversion characteristics are completed, the air cylinder 6 is driven, and the rod is retracted, and the magnetic disk 4 is moved from the measurement position 3 to the position indicated by the solid line in the drawing, which is the initial position. Return and end the measurement. Then, the platen 8 is removed from the carriage 7, the magnetic head 9 of the platen 8 for which the test has been completed is removed, and the magnetic head to be tested next is attached to the platen 8.

As described above, in the embodiment, the rotation axis of the glass disk and the magnetic disk and the center of the measurement position are arranged on a straight line, and each disk moves on the same straight line and is positioned at the measurement position. The straight line connecting the rotation axis of the glass disk and the magnetic disk to the center of the measurement position may be bent in a V-shape with the measurement position as a contact point, or may be inclined. The measurement position may be arranged at the midpoint of the straight line.

In short, as long as the measurement position of the disk is located between the initial position of the glass disk and the initial position of the magnetic disk, it is not always necessary to be on a line connecting these centers. Further, although a glass disk is used as a disk for measuring the flying characteristics, the disk is not limited to a glass disk as long as it is a disk used for measuring the flying height.

In the embodiment, the trajectory of the access process of the magnetic head 9 coincides with the center of each disk. The access direction of the magnetic head may be arranged at right angles.

Further, in the embodiment, each device is placed on the surface plate table. However, this need not necessarily be on the surface plate table.

[Effects of the Invention] As can be understood from the above description, in the present invention, a disk for measuring the flying height and a disk for measuring the electrical characteristics are juxtaposed, and the measurement position is located between them. , And one carriage is provided in common at this measurement position so as to selectively position each disk at this measurement position, so that a magnetic head to be tested for each measurement is attached and detached. There is no need to drive and stop the motors related to the mechanism such as the carriage in each measurement, and it is not necessary to independently start and control each test device and related circuits. The respective data of the conversion characteristics can be easily obtained for the magnetic head being tested.

As a result, the time required to perform each measurement can be reduced, the head flying characteristics and the electromagnetic conversion characteristics can be measured in a short time with one test apparatus, and the measurement efficiency of the entire measurement process can be improved. .

[Brief description of the drawings]

FIG. 1 is a schematic view of an embodiment to which a magnetic head tester of the present invention is applied, and FIG. 2 is a detailed view of a platen portion thereof. 1 ... Stable table, 2 ... Glass disk, 2a, 4a ... Spindle, 3 ... Measurement position, 4 ... Magnetic disk, 5,6 ... Air cylinder, 7 ... Carriage, 8 ... Platen, 9 ... magnetic head, 10 ... holder, 11 ... fixing member, 12 ... positioning pin, 13 ... paddle.

Claims (1)

(57) [Claims] A first disk for measuring flying characteristics of a magnetic head; a second disk for measuring electrical characteristics of the magnetic head; and a first disk between the first and second disks. A measurement position provided for selectively positioning one of the first and second disks; and a first and second disk selectively positioned at the measurement position disposed opposite to the measurement position. A carriage mounted with the magnetic head for accessing each of the
A magnetic head tester wherein the first disk is positioned at the measurement position when measuring the flying characteristics, and the second disk is positioned at the measurement position when measuring the electrical characteristics.