JPH02301011A - Magnetic head tester - Google Patents

Abstract

PURPOSE:To measure floating characteristic and electrical characteristic with one tester in a short time and efficiently by arranging two disks for measuring a floating quantity and the electrical characteristic on the same rotary shaft in upper and lower sides, respectively, and arranging a carriage in common. CONSTITUTION:A magnetic head 9 to be tested is loaded at the prescribed position of the platen 8 of the carriage 7. The measurement of the floating quantity is performed by moving the head 9 to the measuring point of an optical system 23 for measurement after confirming the fact that the carriage 7 is located at the normal position of a glass disk 2 with detecting sensors 17a and 17b by applying the control of a measuring control data processing part 22, and rotating the disk 2. Next, the carriage 7 is moved to a prescribed track on a magnetic disk 4, and the R/W test of the electrical characteristic is performed. All the measurement data are analyzed by the control part 22, and are stored in a memory correspondingly to the data of the magnetic head, then, it is decided whether it is valid or invalid.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head tester, and more particularly to a magnetic head tester that can test a magnetic head used such as a hard magnetic disk in a short time.

[Prior Art] Conventional magnetic head testers have two types: a test device that measures the flying height of a magnetic head, which is its physical characteristic, and a test device that measures its electrical characteristics, which are electromagnetic conversion characteristics. There are different types.

Normally, the characteristics of the magnetic head are inspected using these two types of measuring devices, and generally, the flying characteristics of the magnetic head are first measured, and then the electromagnetic conversion characteristics are measured for those that pass.

[Problem to be solved] Therefore, in order to test a magnetic head, it is necessary to mount the magnetic head on each of two test devices, and the installation and removal work is either time-consuming or difficult. It is necessary to manage the magnetic heads regarding 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 drives have been required to record even higher density than before, and also to ensure high reliability, so they are required to measure the characteristics of magnetic heads. The accuracy is also becoming higher. Therefore, the overall throughput of magnetic head testing tends to decrease. For this reason, when conducting different tests using two test devices as described above, the time it takes to install the magnetic head, and in this case to remove the magnetic head, becomes an issue. The influence is also large, and it becomes a factor that lowers the yield.

The present invention solves the problems of the conventional technology, and makes it possible to measure head flying characteristics and electromagnetic conversion characteristics with one test device, and to improve measurement efficiency. The purpose is to provide a magnetic head tester.

[Means for Solving the Problems] The configuration of the magnetic head tester of the present invention to achieve such objects includes a first disk fixed to a rotating shaft for measuring the flying characteristics of a magnetic head; , for measuring the electrical characteristics of the magnetic head, a second disk fixed to the rotating shaft, and a carriage provided opposite to either the first or second disk and serving as a carriage for the disk. , and a carriage on which a magnetic head is mounted, which is arranged to face the other of the first and second disks by moving a predetermined amount toward the first side or downward, and becomes a carriage for that disk.

[Operation] In this way, by arranging the disk for measuring the flying height and the disk for measuring the electrical characteristics one above the other on the same rotation axis, and providing them with one carriage in common, There is no need to attach or detach the magnetic head to be tested for each measurement, and it is only necessary to move the carriage down -L, so it is possible to drive or stop the motors related to mechanisms such as the carriage in each measurement, and There is no need to start or control each test device or related circuit independently, and data on the flying characteristics and electromagnetic conversion characteristics of the magnetic head can be easily obtained for the magnetic head being tested.

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

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIGS. 1(a) and 1(b) are plane m factor and side schematic views of an embodiment to which the magnetic head tester of the present invention is applied, and FIG. 2 is a detailed view of the platen portion thereof.

In FIG. 1(a), 20 is a magnetic head tester, 21 is a measurement mechanism thereof, and 22 is a measurement control section thereof.
It is a data processing unit and includes a microprocessor, memory, etc.

Reference numeral 1 denotes a surface table provided in the measurement mechanism section 21. On the surface table 1, as shown on the left side of the drawing, a glass disk 2 for measuring the flying characteristics is fixed to the spindle 3. As shown in the side view of FIG. 2B, a magnetic disk 4 (hard disk) for measuring electromagnetic conversion characteristics is fixed to the same spindle 3 below the glass disk 2. A carriage 7 is provided facing the glass disk 2 and magnetic disk 4. As seen in the side view of the same figure (b), an optical system 23 for measuring the flying height is provided on the upper side of the glass disk 2, and a laser beam or a normal light beam is irradiated and reflected. Upon receiving the light, it measures the distance between the glass disk 2 and the magnetic head 9 in the loading state, converts the measurement result into an electrical signal, and converts the measurement result into an electrical signal.
Send to 2.

Here, the spindle 3 is coupled to a motor 5,
It is driven according to a control signal from the measurement control/data processing section 22 during each measurement.

The carriage 7 is moved up and down by a vertical movement mechanism 6 (see FIG. 1(b)) provided under the surface table 1.
It is selectively positioned on the glass disk 2 or the magnetic disk 4 and used as a carriage for these. In addition,
In Figure (b), the position indicated by the solid line is the state where the carriage 7 is placed at the lower initial position and is positioned facing the magnetic disk 4, and the position indicated by the dotted line is the state where the carriage 7 is moved by the vertical movement mechanism. 6 and is positioned opposite the glass disk 2.

Reference numeral 8 denotes a platen which is positioned on the carriage 7 at an accurate position by a pawl mechanism, screws, etc., and is removably fixed thereto.As shown in FIG. A magnetic head 9 is attached. As you can see from Figure 2, which shows the situation,
The magnetic helad 9 is removably fixed to a holder lO above the platen 8.

The holder 10 is composed of a right-angled hook-shaped fixing member 11 having two sides in the right angle direction, which serves as a guide and a stopper, and two positioning pins 12° 12 provided inside the fixing member 11. By moving forward and backward in the direction of 45 degrees, the rectangular member 9a at the base of the magnetic helad 9 comes into contact with each of the right angle sides, and the abutment in the XY direction is stopped and the contact with the two positioning pins 12 and 12 is made. The position and fixation are made between the two. The positioning pins 12.12 position the magnetic head 9 at a more accurate position on the platen 8 by fitting into two positioning holes provided in the rectangular member 9a at the base of the magnetic head 9. do.

13 is a paddle, which has contact stripes 13a and 13b with which the probe comes into contact, and the lead wire 9b of the magnetic helad 9 is connected to this contact stripe l3.
a, 13 connected to b. This is made up of, for example, a small ceramic substrate, and is attached to a box-shaped paddle guide 14 with one end open provided on the platen 8, and is removably fixed from both sides by rotation of rotary molds 15 and 15. Ru.

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 this paddle 13, so that the probe 1B is connected to the contact stripes 13a, 13b provided on the paddle 13. (
(see FIG. 1) is connected to a read/write amplifier (R/W amplifier) 19a arranged on the surface table 1H.

As a result, the magnetic head 9 is connected to the electric circuit of the measurement control/data processing section 22 disposed below the surface plate table 1 via the read/write amplifier 19a.

Reference numerals 17a, 17b, 17c, and 17d are position detection sensors such as photointerrupters and photosensors, respectively, which detect the position of the carriage 7 when the carriage 7 is moved upward or downward by the vertical movement mechanism 6. They detect the positioning reference position by detecting a detection piece, hole, etc. provided in the
These detection outputs are sent to the measurement control/data processing section 22.

Therefore, when the carriage 7 is in the upper position, the position detection sensor 17a detects the position so that the access movement locus of the magnetic disk 9 placed on the platen 8 of the carriage 7 is on the access surface corresponding to the center of the glass disk 2. It is placed at the top and stops moving upwards. In this case, a stopper may be provided to prevent further upward movement. Further, the position detection sensor 17b detects that the carriage 7 is at the reference position when accessing the glass disk 2 at this time. This position is the position of the carriage 7 shown by the dotted line corresponding to the glass disk 2, and is the positioning position of the carriage with respect to the glass disk 2 in measuring the flying characteristics.

When the carriage 7 is in the lower position (initial position), the position detection sensor 17c detects the position so that the access movement locus of the magnetic head 9 faces the access surface corresponding to the center of the magnetic disk 4. will be placed. At this time, the carriage 7 is placed on the base table 1 or fixed thereto and stopped. Further, the position detection sensor 17d detects that the carriage 7 is at the reference position when accessing the magnetic disk 4 at this time. This position is the position of the carriage 7 shown by the dotted line corresponding to the magnetic disk 4, and is the positioning position of the carriage with respect to the magnetic disk 4 in measuring the electromagnetic conversion characteristics.

18 and 19 are respectively glass disks 2. It is a head loading mechanism for the magnetic head 9 provided above and below in correspondence with the magnetic disk 4, and the carriage 7 includes a read/write amplifier that amplifies the electrical signal from the magnetic head 9, as described above. 19a is disposed adjacent to the lower head loading mechanism 19.

Next, the operation will be explained. The magnetic head 9 to be tested is usually placed on a pallet or the like, and is placed separately from the magnetic head tester 20.

One of them is first attached to the holder 10 of the platen 8 and mounted. A platen 8 on which a magnetic head 9 is mounted
is positioned at a predetermined position set on the carriage 7 and mounted on the carriage 7. Note that if the platen 8 is made into an independent unit and the magnetic head 9 is replaceable in this way, even if the shape or form of the magnetic head 9 changes, it is only necessary to change the mounting relationship between the platen 8 and the magnetic head 9. No modification of the device is required.

First, the 7It11 constant control/data processing unit 22 confirms whether the carriage 7 on which the platen 8 is mounted is located on the glass disk 2 side or on the magnetic disk 4 side based on the outputs of the position detection sensors 17a*17c. When it is on the magnetic disk 4 side, the downward movement mechanism 6 is driven in response to a control signal from the measurement control/data processing section 22, and the gear is positioned on the glass disk 2 side. Whether or not the position detection sensor
Similarly confirmed by the output of 7 al l 7 c. Note that this positioning position is detected because the position detection sensor 17a is in the "ON" state and the position detection sensor 17c with respect to the glass disk 2 is in the "OFF" state.

Carriage 7 for the measurement position of this glass disk 2
When the positioning is completed, measurement of the flying height is started.

First, the measurement control/data processing unit 22 checks whether the carriage 7 is in the correct position based on the signal from the position detection sensor 17b, drives the carriage 7, and drives the carriage 7 in the direction of the spindle 3, which is the center of the glass disk 2. The magnetic head 9 is moved toward. Then, the magnetic head 9 is loaded onto the glass disk 2 by the head loading mechanism 18, and the glass disk 2 is rotationally driven. At this point, the magnetic head 9 floats. This is an example of contact start/stop, and the glass disk 2 is inserted before the head is loaded.
may be rotated.

Next, the measurement control/data processing unit 22
is controlled, and the magnetic herad 9 is connected to an optical system 23 for measuring the flying height.
move to a predetermined measurement point, which is the light irradiation point. Then, at this position, the flying height is measured by the optical system 23 for measuring the flying height, and the measurement is stored in the memory of the measurement control φ data processing section 22 in correspondence with the data of the magnetic head.

Note that 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 next magnetic head 9 to be tested is mounted on the platen 8. Then, test the next magnetic head in the same manner as above.

When the measurement of the two floats is completed, the carriage 7 returns to the initial position in the horizontal direction, which is the original reference position. Then, we move on to the measurement of electromagnetic conversion characteristics. The vertical movement mechanism 6 is driven in response to a control signal from the measurement control/data processing unit 22, and the carriage 7 is lowered and returned to the initial position on the lower side.
The carriage 7 is positioned on the side of the magnetic disk 4, and whether or not the carriage 7 has been positioned is similarly confirmed by the output of the position detection sensor 17c. Note that this positioning position detection is performed 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, and first, the CI constant sub-control data processing unit 22 determines that the carriage 7 is correct.

The carriage 7 is further driven based on the signal from the position detection sensor 17d, and the magnetic head 9 is moved toward the spindle 5, which is the center of the magnetic disk 4. let Therefore, the head loading mechanism 18 loads the magnetic head 9 onto the magnetic disk 4.
The magnetic disk 4 is loaded onto the top and driven to rotate. Note that this also applies to the case of contact φ start/stop.

Next, in the same manner as described above, the carriage 7 is controlled by the measurement control/data processing section 22, and the magnetic head 9 is moved to a predetermined track position where the electrical characteristics are to be measured.
Therefore, a read/write (R/W) test is performed.

In the R/W test, with the magnetic head 9 positioned at a predetermined track position, the probe 16 comes into contact with a contact provided on the paddle, and the electrical output of the magnetic head 9 is transmitted to the paddle 13. Probe 16, read/write amplifier 1
A signal is sent to the measurement control/data processing unit 22 via the signal line 9a, which is analyzed by the measurement control φ data processing unit 22, and the data is applied to the data of this magnetic head in the same way as in the measurement of the flying height described above. This is done by storing it in memory. In addition, as in the case of the flying height measurement, if the electromagnetic conversion characteristic measurement results fail, the platen 8 is removed from the Kya'J-/Sif, the magnetic radar 9 is removed from the platen, The next magnetic head 9 to be tested is mounted on the platen 8, and the next magnetic head is tested in the same manner as described above.

In this manner, when the measurement of the floating height and the measurement of the electromagnetic conversion characteristics are completed, the vertical movement mechanism 6 is driven, and the carriage 7 ends the measurement at the position indicated by the solid line in the drawing, which is the initial position. Then, the platen 8 is removed from the carriage 7), the magnetic head 9 of the platen 8 that has been tested is removed, and the next magnetic head to be tested is attached to the platen 8.

As has been explained above, in the embodiment, the glass disk and the magnetic disk are fixed vertically on the axis, but this axis may also be arranged in the horizontal direction, for example, and in this case, , both the glass disk and the magnetic disk will be arranged vertically. Therefore, in the present invention, the angle at which the disk is arranged does not matter.

In the example, the glass disk is on the upper side and the magnetic disk is on the lower side, but the optical system for measuring floating characteristics is placed on -L.
If the glass disk does not need to be placed on the lower side, and the flying characteristics can be measured even with the glass disk on the lower side, the glass disk may be placed on the lower side. Therefore, the vertical relationship between these disks does not matter.

Further, although a glass disk is used as the disk for measuring the flying characteristics, this is not limited to a glass disk as long as it is a disk used for measuring the flying height. Furthermore, in the embodiment, the -
Each device is placed on L, but this does not necessarily have to be on the surface plate.

[Effects of the Invention] As can be understood from the above explanation, in this invention, a disk for measuring flying height and a disk for measuring electrical characteristics are arranged one above the other on the same rotation axis, and these disks are arranged vertically on the same rotation axis. By providing one carriage in common for each measurement, there is no need to attach or detach the magnetic head to be tested for each measurement, and it is only necessary to move the carriage up and down. A magnetic head that tests data on the magnetic head's flying characteristics and electromagnetic conversion characteristics without the need to start or control each test device or related circuit independently. Easily obtained to accommodate.

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

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are a schematic plan view and a schematic side view of an embodiment to which the magnetic head tester of the present invention is applied;
FIG. 2 is a detailed view of the platen portion. ■...Surface table, 2...Glass disk, 3.
...Spindle, 3...Measurement position, 4...Magnetic disk, 5...Motor, 6...-L upward movement mechanism, 7.
... Carriage, 8... Platen, 9... Magnetic head, 10... Holder, 11... Fixing member, 12...
...Positioning bin, 13...Paddle.

Claims (1)

[Claims] (1) A first disk fixed to the rotating shaft for measuring the flying characteristics of the magnetic head, and a second disk fixed to the rotating shaft for measuring the electrical characteristics of the magnetic head. The carriage is provided facing the disk and one of the first and second disks, and is used as a carriage for the disk. A magnetic head tester comprising: a carriage on which the magnetic head is mounted and which is disposed facing each other and serves as a carriage for the disk.