JPS6173221A - Inspecting system of magnetic head - Google Patents

Abstract

PURPOSE:To inspect a magnetic head, by connecting a master magnetic head and the magnetic head to be inspected with a head tester, with the gap of the magnetic head being faced to the gap of the master head with a prescribed interval in between, and detecting the magnetic flux induced by the master head by means of the head to be inspected. CONSTITUTION:A master head (tester head) 11 is connected with a head tester 7 through a write amplifier 8 and a magnetic head to be inspected 12 is also connected with the tester 7 closely to the master head 11 through a read amplifier 9. When a write current is made to flow to the master head 11, a leakage magnetic flux 14 is produced at the gap 13 of the master head 11 and the magnetic flux 14 is detected by the gap 15 of the magnetic head to be inspected 12 and amplified by the read amplifier 9. That is to say, the crosstalk of the master head 11 against the magnetic head to be inspected 12 is received and detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to magnetic head testing, and involves passing a write current to another magnetic head (master magnetic head) connected adjacent to the magnetic head to be tested; The present invention relates to a magnetic head inspection method that actively uses the leakage magnetic flux to detect and amplify it for inspection.

For example, as shown in FIG. 3, a magnetic disk device using a magnetic head includes a magnetic disk 1 rotated by a drive device (not shown), a head arm 3 attached to a head drive positioner 2, and the head arm. 3 through a gimbal spring 4. Note that the positioner 2 in the figure shows a swing arm type, and 6 is a base.

Information is written onto or read from the magnetic disk 1 by the magnetic head 5 during the relative movement between the magnetic nodule 5 and the magnetic disk I.

Since the magnetic head 5 performs reading/writing as described above, characteristic tests such as head output and level resolution are generally performed. This test is performed using a head tester by rotating the master disk disk to levitate the magnetic head, but since the flying height of the magnetic head is small, it is easy to cause a head crash, and magnetic head testing is required to prevent head crashes. A method is desired.

[Conventional technology]

In the conventional magnetic head testing method, as shown in FIG. 4, a head tester 7 includes a write amplifier 8. A magnetic helad 5 is connected through a read amplifier 9, floats above a rotating mask disk 10, and performs read/write operations.
Characteristics are being inspected.

The mask disk 10 is selected from a general magnetic disk, all of its characteristics are measured, and the characteristics of the magnetic head 5 to be tested are evaluated based on the measured characteristics. Also, the magnetic head to be inspected 5
is a printed board with an amplifier mounted on it, lead wires, connectors,
This is the state of the head assembly with the arm etc. assembled.

[Problem that the invention seeks to solve]

In the magnetic head testing method described above, the magnetic head 5 to be tested must be floated above the mask disk 10, and the flying height is as small as 0.2 micrometers.

Therefore, during the rotation of the mask disk 10, the magnetic field to be inspected.

There is a risk that the disk 5 may come into contact with the mask disk 1o due to vibration or the like, causing damage to the magnetic head or causing a crash.

Furthermore, if a head crash occurs, the mask disk 10 becomes unusable, a new mask disk LO must be made, and the magnetic head 5 to be inspected becomes unusable. Furthermore, when setting the magnetic head 5 to be inspected on the master disk 10, the magnetic head 5 is held by the arm 3 via the gimbal spring 4, so be careful not to handle it carefully as it may cause a shock to the mask disk 10. There is a problem that the inspection process is complicated.

[Means for solving problems]

The above problem can be solved by connecting a master magnetic head to a head tester, and connecting the magnetic head to the head tester with the gap of the magnetic head to be tested facing the gap of the master magnetic head at a predetermined distance. This problem is solved by the magnetic head testing method of the present invention, characterized in that the testing magnetic head detects the magnetic flux induced by the master magnetic head to test for abnormalities in the magnetic head to be tested.

[Effect]

The master magnetic head is connected to the head tester through a write amplifier, and the head to be tested is connected closely to the master head through a read amplifier, and the gap magnetic flux of the master head generated by passing a write current is measured. By amplifying and detecting with the magnetic head, each characteristic (resolution, disconnection, etc.) of the magnetic head can be inspected.

〔Example〕

Hereinafter, the gist of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a diagram for explaining one embodiment of the present invention, and FIG. 2 is a diagram showing write current and head output.

Note that the same reference numerals throughout the figures indicate the same objects.

In FIG. 1, the head tester 7 includes a light amplifier 8.
A master head (tester head) 11 is connected through the read amplifier 9, and a magnetic head 12 to be tested is connected in close proximity to the master head 11 through a read amplifier 9. By passing a write current through the master head 11, the gap 13 is
A leakage magnetic flux 14 is generated, this leakage magnetic flux 14 is detected by the magnetic head 12 gear to be inspected and the gear 15, and is amplified by the read amplifier 9. That is, the crosstalk of the master head 11 with respect to the magnetic head 12 to be tested is detected.

Specifically, the differentiated waveform of the write current (rectangular wave) of the master head 11 shown in FIG.
(head output). By using this detected waveform, various characteristics (resolution, disconnection, etc.) of the magnetic head can be inspected. Note that the differentiated waveform described above is the same waveform when reading the magnetic flux written on the magnetic disk.

The magnetic head 12 to be inspected is close to the master head 11 (distance a) as described above, and the proximity a is, for example, 5 dragons in the embodiment, and the magnetic head 12 to be inspected is mounted using a jig and the magnetic head to be inspected at this distance is Standards for determining the quality of the head 12 are determined in advance.

The steps are summarized below: (1) Determine the master head 11 and insert it into the head tester 7.

(2) Determine the magnetic head for determining the standard and place it in the jig.

(3) The influence of the magnetic head on the master head 11 is tested using the head tester 7 and standardized.

(4) After standardization, remove the magnetic head, set the magnetic head 12 to be tested in its place, and judge the test results according to the standard.

The magnetic head inspection described above does not use a master disk as in the conventional method, so the magnetic head 12 to be inspected is not brought into contact with the rotating disk without being levitated above it. Therefore, there is no possibility that a head crash will occur and damage the magnetic head 12 to be inspected, unlike in the conventional case.

Furthermore, since it is only necessary to place the magnetic head 12 to be tested on a jig, the testing process is simple.

〔Effect of the invention〕

As explained above, according to the present invention, the magnetic head to be tested can be easily tested in a non-contact manner by bringing the magnetic head to be tested close to the master head connected to the tester and detecting the leakage magnetic flux of the master head. , there is no damage to the magnetic head like in the conventional case.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining one embodiment of the present invention, Fig. 2 is a diagram showing write current and head output, Fig. 3 is a diagram showing a magnetic disk device, and Fig. 4 is a diagram showing a conventional magnetic disk drive. FIG. 3 is a diagram illustrating a head inspection method. In the figure, 7 is a head tester, 8 is a write amplifier, 9 is a read amplifier, 11 is a master head, 12 is a magnetic head to be tested, 13.15 is a gear, 7 is a pin, and 14 is a magnetic flux.

Claims (1)

[Claims] In a method of testing a magnetic head using a head tester, a master magnetic head is connected to the head tester, and the gap of the magnetic head to be tested is opposed to the gap of the master magnetic head at a predetermined interval. A magnetic head testing method characterized in that the magnetic head to be tested is connected to the head tester, the magnetic head to be tested detects magnetic flux induced by the master magnetic head, and the magnetic head to be tested is tested for abnormalities.