JP2867190B2 - Polishing control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing control device, and more particularly, to a polishing control device suitable for polishing, for example, a pole portion of a thin film magnetic head.

[0002]

2. Description of the Related Art For example, as a device for finishing and polishing a throat height of a pole portion of a thin-film magnetic head to a predetermined size, a head support having the thin-film magnetic head supported on an end face is conventionally mounted on a jig, and this jig is mounted. It is known that the throat height of the pole portion is set to a predetermined value by contacting a rotatingly driven polishing plate.

[0003] In this case, the polishing state of the pole portion is controlled by providing a conductive pattern in advance in a blank area other than the pole portion of the head support and by arranging a conductive brush in contact with the polishing board. This has been done by detecting a conduction state based on a change in resistance between the conductive pattern and the conductive brush and controlling the rotation of the polishing machine.

As another conventional means for controlling the throat height of the pole portion, a polishing state of the pole portion is measured by optical means, and the polishing time of the pole portion by the polishing machine is measured in accordance with the measurement result. In some cases, the throat height of the pole portion is optimized to be controlled.

[0005]

However, in the case of the above-described conventional apparatus, the conductive state of the conductive pattern is detected by bringing the conductive brush into contact with the polishing disk. Therefore, the contact resistance between the conductive brush and the polishing disk is detected. The value is not constant, and as a result, the detection result becomes unstable, and the polishing state of the pole portion cannot be strictly controlled, so that it is difficult to obtain an optimum throat height.

In the means using optical measurement together, there is a time lag between the polishing of the pole portion and the dimension measurement.
In addition, there is a problem that the measurement of the throat height of the pole portion lacks accuracy due to the measurement error. by the way,
As a prior art, there is JP-A-61-115213.
This is because "Either the upper magnetic layer or the lower magnetic layer
Position the board so that the edge is at the position that defines the gap depth.
Formed and positioned in this upper magnetic layer or lower
With a voltage applied between the magnetic layer and the polishing platen,
Polished on one end of
Contact with the top of the layer or lower magnetic layer and it conducts
Finishes the polishing work at the point ".
It is necessary to form the tip of the conductive layer at the specified position.
And formation of a terminal extraction layer to make it conductive.
This increases the number of extra steps. One
In other words, the upper part of the throat height adjustment range is determined at the time of manufacture.
Or it is restricted by the tip position of the lower magnetic layer
Have a title. For this reason, the processing accuracy of the head
Continuity detection is affected and accurate dimensional control can be performed.
Leads to the problem of not having.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polishing control device capable of controlling the size of a polishing area of a polishing object in parallel with the polishing operation and accurately.

[0008]

A polishing control device according to the present invention has an arbitrary number of electromagnetic transducers having a pole portion and a yoke portion at an end, a polishing region facing a lower end, and a polishing region from a lower end. A thin-film magnetic head assembly provided with an arbitrary number of conductive patterns having different distances and supported by a conductive jig that is driven to rotate, and polishing of a thin-film magnetic head assembly supported by the jig that is driven to rotate. A conductive polishing plate for contact-polishing an area and each of the conductive patterns; and a light emitting device disposed on the jig for detecting stepwise conduction between the polishing plate and each of the conductive patterns and transmitting a detection result as an optical signal. A conduction detecting means having an element, a light receiving element for receiving the optical signal of the light emitting element in a non-contact manner and transmitting a signal corresponding to the stepwise conduction of each of the conductive patterns; and a signal from the conduction detecting means. Based on Signal processing means for calculating a polishing rate and a polishing inclination, and control means for controlling the driving of the jig and the polishing board based on the calculation results of the signal processing means and polishing the thin film magnetic head assembly to a target throat height dimension. And characterized in that:

[0009]

The operation of the above-described polishing control device will be described below.

An object to be polished having an arbitrary number of conductive patterns having a polishing area facing the lower end and having a different distance from the lower end face is supported by a jig, and the object to be polished is rotated and driven. Polish by contacting the board.

With the polishing of the object to be polished, the polishing area and an arbitrary number of conductive patterns are gradually polished. At this time, the continuity detecting means on the jig is connected to the polishing plate and each conductive pattern. The stepwise conduction with the pattern is detected, and the detection result is sent out as an optical signal. The light receiving element takes in the optical signal from the light emitting element in a non-contact manner and sends it to the signal processing means as a signal corresponding to the stepwise conduction. Send out.

The signal processing means calculates a polishing rate and a polishing / polishing inclination based on the optical signal, and sends them to the control means.

The control means controls the continuation or stop of the rotation of the jig and the polishing disc based on the signal from the signal processing means. Thus, the size of the polishing region becomes a predetermined size according to the polishing amount of each conductive pattern.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail.

A polishing control device 1 shown in FIG. 1 has a polishing plate 2 having a disk-shaped shaft 2a made of a conductive material such as tin and a polishing plate 2 parallel to the upper surface of the polishing plate 2 at a predetermined interval. A rectangular jig 3 made of a conductive material and arranged in a substantially rectangular parallelepiped, and a jig 5 composed of a rectangular jig 4 made of a conductive material attached to each of four sides of the rectangular jig 3, And a magnetic head assembly 6 as a rectangular parallelepiped object to be polished, the upper surface side of which is attached and the lower surface side of which is in contact with the upper surface of the polishing plate 2.

As shown in FIGS. 2 and 3, the magnetic head assembly 6 has a slider portion 7 made of a conductive ceramic material.
An arbitrary number of electromagnetic transducers 9 each having a pole portion 9a provided inside an insulator 8 laminated on one end surface of the slider portion 7; and a conductive pattern which will be described in detail after being provided inside the insulator 8 as well. 10 is provided.

The polishing control device 1 further detects conduction between the conductive pattern 10 disposed at both corners of the upper surface of the prism jig 4 and the polishing board 2, and transmits a pair of conduction signals for transmitting the detection result as an optical signal. Detecting means 11 and each conduction detecting means 1
A pair of light receiving means 12 for receiving an optical signal from the light receiving means 1 and a control for processing an output signal of each light receiving means 12 and transmitting a control signal for rotationally driving the jig 5 and the polishing board 2 based on the output signal. It has a means 13 and a rotation driving means 14 for taking in a control signal and driving and stopping the polishing disk 2 based on the control signal.

A shaft 3 having a rotary bearing only at a lower end from the center of the square jig 3 constituting the jig 5 upward.
a is protruded and connected to the arm 3b. Arm 3
b is repeatedly linearly driven from the outside.

Accordingly, the jig 5 is rotated by the linear driving of the polishing disk 2 and the arm 3b which are driven to rotate, whereby the lower surface of the magnetic head assembly 6 brought into contact with the upper surface of the polishing disk 2 can be polished. And

Here, the pole portion 9a of the electromagnetic transducer 9 in the magnetic head assembly 6 and the conductive pattern 10
Will be described with reference to FIGS. 3 and 4. FIG.

A total of four conductive patterns 10 are formed at both corners of the insulator 8. The conductive pattern 10 is formed by forming first and second patterns 15 and 16 formed to a thickness of about 1000 to 3000 angstroms by a thin film technique using a conductive material such as Ti, Cr, Fe, and Ni alloy with a small interval. Formed and provided.

The first and second patterns 15 and 16 are respectively pin contact patterns 15a and 16a having a length of about 400 μm and a width of about 250 μm in FIG.
Width 1 derived from 5a, 16a to the vicinity of the lower surface of insulator 8
It has detection patterns 15b and 16b of 0 to 50 μm. The distances L1 and L2 from the protruding ends of the detection patterns 15b and 16b to the lower surface of the insulator 8 are, for example, about 1 μm.
It is formed with the difference of. Similarly, third and fourth patterns 17 and 18 are formed at the other corners.

Further, pin contact patterns 17a and 18a and detection patterns 17b and 18b are formed.

The distances L3 and L4 from the protruding ends of the detection patterns 17b and 18b to the lower surface of the insulator 8 are also about 1 μm.
m and L1 and L3, L2 and L4
Are designed and arranged at the same distance from the electromagnetic conversion element 9.

The continuity detecting means 11 is fixedly arranged on the jig 5 by a magnet or the like, is led out of the continuity detecting means 11, passes through the side of the prism jig 4, and
Further, each of the pin contact patterns 15a, 16a, 17
a, four contact pins 1 made of conductive material abutting against 18a
9, 20, 21, 22 and 4 corresponding to the respective contact pins 19, 20, 21, 22 arranged in the detection means 11.
Detection circuits 23, 24, 25, 26 (shown in FIG. 5)
And four light-emitting elements 27 and 28 such as LEDs connected to the output sides of the detection circuits 23, 24, 25 and 26, respectively, and arranged on the upper surface of the detection means 11 radially from the center of rotation. , 29, and 30. The ground terminal 31 of the detecting means 11 is maintained at a ground level through the slider part 7, the prism jig 4 and the square jig 3 by connecting a ground wire 32 to the detecting means 11 and the square jig 3. It has become so.

FIG. 6 shows a concrete circuit example of the detection circuit 23 (the same applies to the detection circuits 24, 25 and 26). This detection circuit 23
Is a C-MOS having a clock (CLK) terminal connected to the contact pin 19 and an output terminal connected to the light emitting element 27.
A D-type flip-flop 33; a first resistor R1 connected between the clock terminal and a power supply (Vcc) such as a battery; a capacitor C connected between the clock terminal and ground; Set terminal (S)
A second resistor R2 connected between the power supply and the ground, and a reset switch 41 connected between the power supply and the set terminal. In FIG. 6, R3 is a bias resistance of the light emitting element 27.

The light receiving means 12 is fixedly arranged on the shaft 3a, and the light emitting elements 27, 28, 29,
In order to receive the optical signal from the light receiving element 30 (shown in FIG. 5), the light receiving elements 3 arranged in a row in the radial direction with respect to the rotation axis 3a are opposed to each other.
4, 35, 36 and 37 are provided.

Therefore, the light emitting elements 27, 28, 29, 30
Each time the jig 5 makes one rotation, the respective optical signals from the optical elements are incident on the respective light receiving elements 34, 35, 36, and 37.
Each is converted into an electric signal.

The control means 13 includes the light receiving elements 34 and 3
A signal processing unit 38 which takes in the output signals from the signal processing units 5, 36 and 37, processes the signals, and outputs the signals; and a control signal for driving or stopping the rotation driving means 14 based on the signals from the signal processing unit 38. And a control unit 39 for sending out.

Next, the operation of the polishing control device 1 having the above configuration will be described.

As shown in FIGS. 1 to 3, while the magnetic head assembly 6 attached to the lower surface of the prism jig 4 is in contact with the upper surface of the polishing disk 2, the polishing disk 2 is rotated by the rotation driving means 14. And the jig 5 is moved in the arm 3 direction.
b drives linearly in the β direction. Then, the jig 5
Performs a rotary motion, and the lower surface of the magnetic head assembly 6 and the lower end of the pole portion 9a are gradually polished. When the polishing dimension on the lower surface side of the magnetic head assembly 6 becomes L2, the protruding end of the polishing pattern 16b of the second pattern 16 comes into contact with the polishing board 2, thereby forming the contact pattern of the second pattern 16. The contact pin 20 in contact with 16a and the ground terminal 31 have the same potential, that is, the ground potential, and are in a conductive state. This is because the polishing machine 2, the slider part 7, the prism jig 4, and the square jig 3 are all made of conductive material, so that they are in a conductive state, and the square jig 3 and the ground terminal 31 are grounded. This is because the connection is made by the line 32.

When the contact pin 20 and the ground terminal 31 become conductive, an input signal is input to the clock terminal of the flip-flop 33, whereby the output terminal of the flip-flop 33 is changed from the previous “high” state to the “low” state. Turned into a state,
When a current flows through the light emitting element 28, the light emitting element 28
An optical signal indicating the conduction between the pattern 16 and the polishing board 2 is emitted upward.

In this case, the conduction detecting means 11 including the light emitting element 28 rotates together with the jig 5,
Since the light receiving element 35 of the light receiving means 12 is fixedly disposed above the rotation region 8, the optical signal from the light emitting element 28 periodically enters the light receiving element 35.

The light receiving element 35 converts the incident optical signal into an electric signal and sends it to the signal processing section 38. As the polishing proceeds, that is, when the polishing dimensions on the lower surface side of the magnetic head assembly 6 become L4 and L1, the detection patterns 18b and 1 are detected.
5b sequentially comes into contact with the polishing machine 2, and the conduction detecting means 11,
An electric signal is transmitted to the signal processing unit 38 through the light receiving unit 12. (Electrical signals may be sent simultaneously from the left and right light receiving elements 35, 37 and 36, 38.) In the signal processing unit 38, polishing is performed based on a difference in signal input time from the conductive patterns 16 and 15. Calculate the polishing rate in the middle,
Further, the polishing inclination during polishing is calculated from the difference between the signal input times from the conductive patterns 16 and 18, and the processing result is sent to the control unit 3.
Send to 9. The control unit 39 determines the pole unit 9 based on the processing result.
In order to set a to a desired throat height LX, for example, a control signal for stopping the polishing disc 2 is transmitted to the rotation driving unit 14.
To send to. As a result, the rotation driving means 14 stops the polishing machine and stops the polishing. The signal processing unit 38 is described below.
The calculation method in is described.

The polishing dimensions L 1,
Let h be the difference between L2. It is also assumed that there is no difference between the polishing dimensions L2 and L4 of the conductive patterns 16 and 18, and the distance between the patterns 16 and 18 is L.

The signal input times from the conductive patterns 15, 16 and 18 are T1, T2 and T4. Then
The polishing rate Δh and the polishing inclination Δd are as follows: Δh = h / (T1−T2) (μm / sec) Δd = (T4−T2) Δh / L (μm)

By the above operation, an arbitrary number of electromagnetic transducers 9
The magnetic head assembly 10 having a shape close to the target throat height LX can be formed. Thereafter, the magnetic head assembly 6 is removed from the prism jig 4, and the magnetic head assembly 6 is cut into a predetermined size. As a result, a thin-film magnetic head 40 having the electromagnetic transducer 9 having the desired throat height shown in FIG. 7 on the end face can be obtained.

In the operation described above, by appropriately changing and setting the values of the first resistor R1 and the capacitor C, disturbance noise can be cut off and the detection sensitivity of the conduction detecting means 11 can be improved.

Since the signal transmission between the conduction detecting means 11 and the light receiving means 12 is performed in a non-contact state by an optical signal, the throat height of the pole portion 9a can be controlled more accurately than in the conventional example using a conductive brush. Can be performed.

Since the polishing of the pole portion 9a and the throat height dimension control are performed in parallel, it is possible to improve the efficiency of the polishing and throat height dimension control work. The present invention can be variously modified within the scope of the gist, in addition to the embodiments described above.

For example, in the above-described embodiment, each contact pin is constituted by one contact. However, each contact pin is constituted by two contact pins, and each contact pin is brought into contact with a different position of each conductive pattern, thereby forming each contact pin. Contact can be further ensured.

Further, the connection between the conductive pattern and the conductive detecting means may be performed by bonding a conductive wire instead of using the contact pins.

[0043]

According to the present invention described in detail above, with the above-described structure, the polishing operation of the polishing region of the thin-film magnetic head assembly and the management of the polishing region size are performed in parallel and accurately. It is possible to provide a polishing control device which can perform the polishing and contribute to the improvement of work efficiency and productivity.

[Brief description of the drawings]

FIG. 1 is a schematic layout diagram showing a configuration of an apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a polishing machine, a jig, a magnetic head assembly, detecting means, and light receiving means of the apparatus.

FIG. 3 is a partially enlarged side view of a polishing machine, a jig, a magnetic head assembly, detecting means, and light receiving means of the apparatus.

FIG. 4 is an enlarged plan view of the electromagnetic transducer and the conductive pattern of the present embodiment.

FIG. 5 is a block diagram of a detecting unit and a light receiving unit according to the embodiment;

FIG. 6 is a specific circuit diagram of a detecting unit and a light receiving unit of the present embodiment.

FIG. 7 is a perspective view of a thin-film magnetic head obtained by a polishing operation of the apparatus of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polishing control apparatus 2 Polishing board 5 Jig 6 Magnetic head assembly 10 Conductive pattern 11 Conduction detecting means 12 Light receiving means 13 Control means 14 Rotation driving means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-5709 (JP, A) JP-A-4-368605 (JP, A) JP-A-4-241209 (JP, A) JP-A-5-Japanese 28433 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) G11B 5/31

Claims (7)

(57) [Claims] 1. An electro-optical device comprising: an arbitrary number of electromagnetic transducers having a pole portion and a yoke portion at an end portion; and an arbitrary number of conductive patterns having a polishing region facing a lower end and a different distance from the lower end surface. A thin-film magnetic head assembly supported by a conductive jig that is rotationally driven; and a conductive layer that is contact-polished with a polishing region of the thin-film magnetic head assembly supported by the jig and each of the conductive patterns. A polishing disc, a light emitting element disposed on the jig, for detecting stepwise conduction between the polishing disc and each conductive pattern, and transmitting a detection result as an optical signal; A continuity detecting means having a light receiving element for transmitting a signal corresponding to the stepwise conduction of each of the conductive patterns taken in by contact, and a signal for calculating a polishing rate and a polishing inclination based on a signal from the continuity detecting means Processing hand Polishing control, comprising: a step; and control means for controlling the driving of the jig and the polishing board based on the calculation result of the signal processing means and polishing the thin film magnetic head assembly to a target throat height dimension. apparatus. 2. The polishing control device according to claim 1, further comprising a jig provided with a mechanism for connecting said conductive pattern and said conduction detecting means through a contact pin. 3. A flip-flop circuit for detecting a voltage drop due to conduction and providing a conduction detection signal is provided for each of both ends of the thin film magnetic head assembly, and the conduction detection signal is converted into an optical signal during polishing rotation. 2. The polishing control device according to claim 1, further comprising the conduction detecting means including four light emitting elements and four light receiving elements for transmitting to an external signal processing means. 4. The polishing control according to claim 1, wherein the jig has a mechanism for standing two contact pins on the pattern in order to confirm reliable conduction between the pattern and the contact pins. apparatus. 5. The conductive pattern according to claim 1, wherein the conductive pattern has a tip shape capable of making good conductive contact with a polishing board, and has a shape necessary for erecting two contact pins. Item 4. A polishing control device according to Item 1. 6. The conductive pattern and the head support using the thin-film magnetic head assembly having conductivity and the head support having conductivity to detect conduction between the conductive pattern and the conductive polishing machine. 2. The polishing control device according to claim 1, wherein conduction between the two is detected. 7. The connection between the conductive pattern and the conduction detecting means by bonding a conductive wire.
The polishing control device according to the above.