JP2598700B2 - 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] To achieve such an object, a magnetic head tester according to the present invention comprises a first disk fixed to a rotating shaft for measuring a flying characteristic of a magnetic head. A second disk fixed to the rotating shaft for measuring electrical characteristics of the magnetic head; and a carriage for the disk provided opposite to one of the first and second disks. And a carriage for mounting a magnetic head serving as a carriage for the first and second disks by being moved upward or downward by a predetermined amount and facing the other of the first and second disks.

[Operation] As described above, the disk for measuring the flying height and the disk for measuring the electrical characteristics are vertically arranged on the same rotation axis, and one carriage is commonly provided for these. It is not necessary to attach / detach the magnetic head to be tested for each measurement, and only the vertical movement of the carriage is required, so that the motor related to the mechanism such as the carriage in each measurement is driven and stopped, and each test is performed. It is not necessary to independently start and control the apparatus and related circuits, and 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 testing.

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.

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

In FIG. 1A, 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. And a magnetic disk 4 for measuring electromagnetic conversion characteristics as seen in the side view of FIG.
A (hard disk) is fixed to the same spindle 3 below the glass disk 2. A carriage 7 is provided to face the glass disk 2 and the magnetic disk 4. As shown in the side view of FIG. 2B, an optical system 23 for measuring the flying height is provided on the upper side of the glass disk 2, and is irradiated with laser light or a normal light beam to reflect the light. Upon receiving the light, the distance between the glass disk 2 and the magnetic head 9 in the loaded state is measured, and the measurement result is converted into an electric signal, and the measurement control / data processing unit is used.
Send to 22.

Here, the spindle 3 is connected to the motor 5 and is driven according to a control signal from the measurement control / data processing unit 22 at each measurement.

The carriage 7 is moved up and down by an up and down movement mechanism 6 (see FIG. 1 (b)) provided below the platen table 1, and is selectively positioned on the glass disk 2 or the magnetic disk 4. Used as a carriage. The position shown by the solid line in FIG.
Is located at the lower initial position and is positioned facing the magnetic disk 4, and the position indicated by the dotted line is
In this state, the carriage 7 is moved upward by the up-down movement mechanism 6 and is positioned to face the glass disk 2.

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 to abut in the XY direction to perform two positioning pins 12,12.
Is fixed between them. 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. When the carriage 7 is moved up or down by the up-down moving mechanism 6, the position of the carriage 7 is changed. By detecting the detection pieces, holes, and the like provided in the device, they detect the positioning reference position, and their detection outputs are sent to the measurement control / data processing unit 22.

Therefore, when the carriage 7 is at the upper position,
By detecting the position of the position detecting sensor 17a, the access movement locus of the magnetic head 9 mounted on the platen 8 of the carriage 7 is arranged on the access surface corresponding to the center of the glass disk 2, and the upward movement is stopped. Note that, in this case, a stopper for preventing further upward movement may be provided. At this time, the position detection sensor 17b detects that the carriage 7 is at the reference position when the glass disk 2 is accessed. This position is the position of the carriage 7 indicated by a dotted line corresponding to the glass disk 2, and is the positioning position of the carriage relative to the glass disk 2 in the measurement of the flying characteristics.

When the carriage 7 is in the lower position (initial position), the position of the magnetic head 9 is detected by the position detection sensor 17c so that the access movement trajectory of the magnetic head 9 corresponds to the access surface corresponding to the center of the magnetic disk 4. Placed. At this time, the carriage 7 is mounted on the base table 1 or fixed thereto and stopped on the base. At this time, the position detection sensor 17d detects that the carriage 7 is at the reference position when the magnetic disk 4 is accessed. This position is the position of the carriage 7 indicated by a dotted line corresponding to the magnetic disk 4, and is the positioning position of the carriage with respect to the magnetic disk 4 in the measurement of electromagnetic conversion characteristics.

18 and 19 are glass disk 2 and magnetic disk 4 respectively
And a head loading mechanism for the magnetic head 9 provided vertically above and below the read / write amplifier 19a for amplifying the electric signal from the magnetic head 9 on the carriage 7 as described above. Is disposed 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 up / down moving mechanism 6 is driven in accordance with a control signal from the measurement control / data processing unit 22, the carriage 7 is positioned on the glass disk 2 side, and it is determined whether or not the positioning has been performed. The same is confirmed by the outputs of the sensors 17a and 17c. The detection of the positioning position is based on the fact that 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 in the horizontal direction, which is the original reference position. Then, the process proceeds to the measurement of the electromagnetic conversion characteristics. This is because the vertical movement mechanism 6 is driven in response to a control signal from the measurement control / data processing unit 22, the carriage 7 descends and returns to the lower initial position, and the carriage 7 is positioned on the magnetic disk 4 side. Whether or not positioning has been performed is similarly confirmed by the output of the position detection sensor 17c. The detection of the positioning position is based on the fact that 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.
W) The 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 are completed in this way, the vertical moving mechanism 6 is driven, and the carriage 7 ends the measurement at the initial position indicated by the solid line in the drawing. 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 axis in which the glass disk and the magnetic disk are fixed vertically is set up vertically, but this axis may be arranged, for example, in the horizontal direction. In this case, The glass disk and the magnetic disk are both arranged vertically. Therefore, in the present invention,
The angle at which the disks are arranged does not matter.

In the embodiment, the glass disk is on the upper side and the magnetic disk is on the lower side, but it is not necessary to place an optical system for measuring the flying characteristics on the upper side. It may be on the lower side. Therefore, the upper and lower relations of these disks may be either.

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. 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, in the present invention, a disk for measuring the flying height and a disk for measuring the electrical characteristics are arranged vertically on the same rotation axis, and By providing one carriage in common, there is no need to attach / detach a magnetic head to be tested for each measurement, and only the vertical movement of the carriage is required, which is related to a mechanism such as a carriage in each measurement. There is no need to independently drive and stop the motor, and start and control each test device and related circuits.
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]

FIGS. 1A and 1B are a schematic plan view and a schematic side view of an embodiment to which a magnetic head tester according to the present invention is applied.
FIG. 2 is a detailed view of the platen portion. DESCRIPTION OF SYMBOLS 1 ... Surface plate table, 2 ... Glass disk, 3 ... Spindle, 3 ... Measurement position, 4 ... Magnetic disk, 5 ... Motor, 6 ... Vertical movement mechanism, 7 ... Carriage, 8 ... Platen, 9 ... magnetic head, 10 ... holder, 11 ... fixing member, 12 ... positioning pin, 13 ... paddle.

Claims (1)

(57) [Claims] 1. A method for measuring the flying characteristics of a magnetic head, comprising:
A first disk fixed to a rotating shaft, a second disk fixed to the rotating shaft for measuring electrical characteristics of the magnetic head, and one of the first and second disks , Which is provided as a carriage for the disk and is moved upward or downward by a predetermined amount to
A magnetic disk tester comprising: a carriage for mounting the magnetic head, which is arranged to face the other of the second disk and serves as a carriage for the disk.