JP2598699B2 - 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.

[Prior 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 characteristics, and a carriage arranged between the first disk and the second disk and mounted with a magnetic head opposed to the first disk for measuring flying characteristics by rotation Are selectively positioned at a first carriage position at which a magnetic head is mounted and a second carriage position at which a magnetic head-mounted carriage is arranged facing the second disk to measure electrical characteristics. And a carriage on which a magnetic head to be tested is mounted.

[Operation] As described above, the disk for measuring the flying height and the disk for measuring the electrical characteristics are juxtaposed, one carriage is provided in common between them, and the disk is rotated. By accessing each disk, it is not necessary to attach and detach the magnetic head to be tested for each measurement, and it is only necessary to rotate the carriage, which is related to the mechanism such as the carriage in each measurement. It is not necessary to independently drive and stop the motor to be activated, and to start and control each test device and related circuits independently.The magnetic head tests the data of the flying characteristics and electromagnetic conversion characteristics of the magnetic head. It is easy to obtain.

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 diagram of one embodiment to which the magnetic head tester of the present invention is applied, FIG. 2 is a detailed diagram of a platen portion thereof, and FIG. 3 is a schematic diagram of another embodiment. .

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 platen table provided in the measuring mechanism section 21. On the platen table 1, a glass disk 2 for measuring a floating characteristic is fixed to a spindle 3 as shown on the left side of the drawing. A magnetic disk 4 (hard disk) for measuring electromagnetic conversion characteristics is fixed to a spindle 5 as seen on the right side of the drawing. Between the glass disk 2 and the magnetic disk 4, there is provided a carriage 7 which is rotated to access these disks and is positioned opposite to a position which becomes a dedicated carriage for each disk. In addition, 23 shown by the dotted line is
A flying height measuring optical system disposed on the upper side of the glass disk 2 for irradiating a laser beam or a normal light beam to receive reflected light, and the magnetic head 9 in a loaded state with the glass disk 2 Is measured, the measurement result is converted into an electric signal, and sent to the measurement control / data processing unit 22.

Here, the spindle 3 and the spindle 5 are connected to independent motors, respectively, and are independently driven at the time of each measurement in accordance with a control signal from the measurement control / data processing unit 22.

The carriage 7 is rotated by 180 degrees by a rotation drive mechanism 6 (indicated by a dotted line) provided below the surface table 1 to selectively move to a position where the magnetic head 9 accesses the glass disk 2 or the magnetic disk 4. Positioned and used as these carriages. In the drawing, the position indicated by a solid line is a state in which the carriage 7 is positioned to face the glass disk 2, and the position indicated by a dashed line is a state in which the carriage 7 is positioned to face the magnetic disk 4. The shaft 6a rotated by the rotation drive mechanism 6 is the center of rotation.

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. 1 (see FIG. 1) is contacted and connected to a read / write amplifier (R / W amplifier) 19a arranged on the base table 1. As a result, the magnetic head 9 is connected to the electric circuit of the measurement control / data processing unit 22 disposed below the base table 1 via the read / write amplifier 19a.

17a, 17b, 17c, and 17d are position detecting sensors such as a photo interrupter and a photo sensor, respectively. The position of the carriage 7 is provided on the carriage 7 when the carriage 7 is rotationally driven by the rotation driving mechanism 6. By detecting the detected detection pieces, holes, and the like, it is detected that they are at the positioning reference position, and their detection outputs are sent to the measurement control / data processing unit 22.

Therefore, the carriage 7 is disposed so as to face the center of the glass disk 2 so that the access movement trajectory of the magnetic head 9 mounted on the platen 8 of the carriage 7 is detected by the position detection of the position detection sensor 17a. Is stopped. 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 4, and the carriage 7 becomes the carriage of the glass disk 2. Further, a stopper or the like may be provided at this stop position. This position is the rotation stop position of the carriage 7 indicated by a solid line corresponding to the glass disk 2, and is the positioning position of the carriage with respect to the glass disk 2 in the measurement of the flying characteristics. The position detection sensor 17b detects that the carriage 7 has been positioned at a reference position when the glass disk 2 is accessed.

In addition, the carriage 7 is disposed so as to oppose the access movement locus of the magnetic head 9 corresponding to the center of the magnetic disk 4 by the position detection of the position detection sensor 17c, and its rotation is stopped. At this time, the carriage 7 and the magnetic disk 4 are arranged to face each other, the center line of the magnetic head 9 coincides with the rotation center of the magnetic disk 4, and the carriage 7 becomes the carriage of the magnetic disk 4. Also, a stopper or the like may be provided at this stop position. This position is a rotation stop position of the carriage 7 indicated by a dotted line corresponding to the magnetic disk 4, and is a positioning position of the carriage with respect to the magnetic disk 4 in electromagnetic conversion characteristic measurement. The position detection sensor 17d detects that the carriage 7 has been positioned at a reference position for accessing the magnetic disk 4.

Reference numerals 18 and 19 denote head loading mechanisms for the magnetic head 9 provided respectively corresponding to the glass disk 2 and the magnetic disk 4, and the electric load from the magnetic head 9 is provided on the magnetic disk 9 side as described above. A read / write amplifier 19 a for amplifying a typical signal is provided adjacent to the head load mechanism 19.

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 set 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 determines whether the carriage 7 on which the platen 8 is mounted is located on the glass disk 2 side or the magnetic disk 4 side.
Confirm by the output of c. When it is located on the magnetic disk 4 side, the rotation drive mechanism 6 is driven in accordance with a control signal from the measurement control / data processing unit 22, and the carriage 7 is rotationally positioned on the glass disk 2 side. The same is confirmed by the outputs of the detection sensors 17a and 17c. In this case, the detection of the positioning position is performed as follows.
This is because the position detection sensor 17a is in the "ON" state and the position detection sensor 17c for the glass disk 2 is in the "OFF" state.

When the positioning of the carriage 7 with respect to the measurement position of the glass disk 2 is completed, the measurement of the flying height is started. First, the measurement control / data processing unit 22
The carriage 7 is driven after confirming whether or not is at a regular position by the signal of the position detection sensor 17b, and the magnetic head 9 is moved in the direction of the spindle 3 which is the center of the glass disk 2. 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, and 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. Then, the process proceeds to the measurement of the electromagnetic conversion characteristics. This is because the rotation drive mechanism 6 is driven in response to a control signal from the measurement control / data processing unit 22, the carriage 7 is rotationally positioned on the magnetic disk 4 side, and the output of the position detection sensor 17c determines whether or not the positioning has been performed. Is also confirmed by The detection of this positioning position
This is because the position detection sensor 17a is in the "OFF" state and the position detection sensor 17c for the magnetic disk 4 is in the "ON" state.

Next, the carriage 7 is controlled by a control signal from the measurement control / data processing unit 22. First, the measurement control / data processing unit 22 determines whether the carriage 7 is at a regular position by the position detection sensor 17d. The carriage 7 is further driven based on the signal, and the magnetic head 9 is moved toward the spindle 5 which is the center of the magnetic disk 4.
To move. Then, the magnetic head 9 is loaded onto the magnetic disk 4 by the head loading mechanism 18, and the magnetic disk 4 is driven to rotate. This is also the case of contact start / stop. Then, as before,
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 a read / write (R / W) test 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 unit 22 via the write amplifier 19a, and the signal is sent to the measurement control / data processing unit 22 for analysis.The data is analyzed by the data processing unit 22 in the same manner as the measurement of the flying height. 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 measurement of the electromagnetic conversion characteristics is unacceptable, the platen 8 is removed from the carriage 7 and
The magnetic head 9 is removed from the platen, the magnetic head 9 to be tested next 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 and the measurement of the electromagnetic conversion characteristics have been completed in this way, the rotation drive mechanism 6 is driven, and the carriage 7 returns to the initial position as indicated by the solid line in the drawing, and the measurement ends. Then, the platen 8 is removed from the carriage 7, the magnetic head 9 of the platen 8 for which the test is completed is removed, and the next magnetic head to be tested is the platen 8.
Attached to

FIG. 3 shows an embodiment in which the rotation angle of the carriage 7 is changed from 180 degrees to 90 degrees, and the operation of each part is as follows. Except for the positioning, it is the same as the above-mentioned embodiment, and will not be described.

As described above, in the embodiment, it is needless to say that the rotation angle of the carriage is not limited to 180 degrees or 90 degrees. Further, the trajectory of the access process of the magnetic head 9 coincides with the center of each disk, but the access direction of the magnetic head may be arranged at right angles without doing so.

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

[Effects of the Invention] As can be understood from the above description, according to the present invention, a disk for measuring the flying height and a disk for measuring the electrical characteristics are juxtaposed, and one disk is provided between them. By providing a common carriage and rotating it to access each disk, it is not necessary to attach and detach the magnetic head to be tested for each measurement, just rotate the carriage. It is not necessary to independently drive and stop the motor related to the mechanism such as the carriage in each measurement, and to start and control each test device and related circuits independently,
The data of the flying characteristics and the electromagnetic conversion characteristics of the magnetic head can be easily obtained in correspondence with 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 diagram of an embodiment to which the magnetic head tester of the present invention is applied, FIG. 2 is a detailed diagram of a platen portion thereof, and FIG. 3 is a schematic diagram of another embodiment. Reference Signs List 1 ... Stable table, 2 ... Glass disk, 3,5 ... Spindle, 3 ... Measurement position, 4 ... Magnetic disk, 6 ... Rotation drive mechanism, 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 a flying characteristic of a magnetic head; a second disk for measuring an electrical characteristic of the magnetic head; and a first disk for measuring an electrical characteristic of the magnetic head. And a second carriage for measuring an electrical characteristic and a first carriage position where a carriage on which a magnetic head is mounted is arranged opposite to the first disk to measure the flying characteristics by rotating. A magnetic head tester, comprising: a carriage for mounting the magnetic head, which is selectively positioned at a second carriage position where a carriage for mounting the magnetic head is disposed facing the disk.