JPH0536031A - Grinding controller - Google Patents

Abstract

PURPOSE:To improve a working efficiency by operating the management of the dimension of the grinding area of an object to be ground in parallel with the grinding operation by a control means. CONSTITUTION:A grinding controller 1 is equipped with a grinding device 2 having a shaft 2a formed like a disc of a conductive material such as an Sn, and a jig 5 constituted of a four-sided jig made of the conductive material arranged in parallel with the grinding device 2 at a prescribed interval, and a prismatic jig made of the conductive material attached to the outside of the four sides. Moreover, this device is equipped with a magnetic head assembly 6 as a rectangular parallelipiped object to be ground, which is attached to the lower face side of the four-sided jig, and whose lower face is connected with the upper face of the grinding device 2. The grinding controller 1 detects the continuity of conductive patterns provided at the both corners of the upper face of the prismatic jig with the grinding device 2, and the detected result is transmitted by a pair of continuity detecting means 11 as an optical signal, and this light is received by a pair of light receiving means 12. Then, the output signal is processed, and a control signal for driving the rotation of the jig 5 and the grinding device 2 is controlled by a control means 13. Thus, the manage of the grinding operation can be exactly operated in parallel with the management of the dimension of the grinding area, so that the working efficiency can be improved.

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 which is suitable for polishing 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 the throat height of a pole portion of a thin film magnetic head to a predetermined size, a head support body that supports the thin film magnetic head on its end face is conventionally attached to a jig and It is known that the throat height of the pole portion is set to a predetermined value by coming into contact with a rotating polishing machine.

In this case, in order to control the polishing state of the pole portion, a conductive pattern is provided in advance in a blank area other than the pole portion of the head support, and a conductive brush is placed in contact with the polishing plate, This is done by detecting the conduction state based on the resistance value change between the conductive pattern and the conductive brush and controlling the rotation of the polishing plate.

Further, as another means for controlling the throat height dimension of the pole portion in the related art, the polishing state of the pole portion is measured by an optical means, and the polishing time of the pole portion by the polishing disk is measured according to the measurement result. It is also under control to optimize the throat height dimension of this pole part.

[0005]

However, in the case of the above-mentioned conventional apparatus, since the conductive brush is brought into contact with the polishing plate to detect the conduction state with the conductive pattern, the contact resistance between the conductive brush and the polishing plate is detected. The value is not constant, and as a result, the detection result becomes unstable, the polished state of the pole portion cannot be strictly controlled, and it is difficult to obtain the optimum throat height.

Further, in the means which uses optical measurement together, there is a time lag between the time of polishing the pole portion and the time of dimension measurement,
Further, there is a problem in that the throat height dimension control of the pole portion lacks accuracy because of a measurement error.

Therefore, an object of the present invention is to provide a polishing control device capable of accurately controlling the size of a polishing region of an object to be polished in parallel with the polishing operation.

[0008]

A polishing control apparatus of the present invention has an arbitrary number of electromagnetic conversion elements having a pole portion and a yoke portion at an end thereof, and a polishing region is made to face a lower end side of the polishing control device. Polishing of a thin film magnetic head assembly, which has an arbitrary number of conductive patterns with different distances and is supported by a rotationally driven conductive jig, and a thin film magnetic head assembly, which is rotationally driven and supported by the jig. A light emitting plate which is provided on the jig to detect the stepwise conduction between the polishing plate and each conductive pattern and sends the detection result as an optical signal. Continuity detecting means having an element and a light receiving element for receiving the optical signal of the light emitting element in a non-contact manner and transmitting a signal according to the stepwise conduction of each conductive pattern, and a signal from the continuity detecting means. Based on A signal processing means for calculating a polishing rate and a polishing inclination, and a control means for controlling the driving of the jig and the polishing plate based on the calculation result of the signal processing means to polish the thin film magnetic head assembly to a desired throat height dimension. It is characterized by having.

[0009]

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

A polishing object having a polishing region facing the lower end side and provided with an arbitrary number of conductive patterns having different distances from the lower end surface is supported by a jig, and the polishing object is electrically driven to rotate. Touch the plate and polish.

With the polishing of such an object to be polished, the polishing region and an arbitrary number of conductive patterns are gradually polished. At this time, the conduction 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, and the light receiving element captures the optical signal from the light emitting element in a non-contact manner, and 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 inclination based on the optical signal and sends it to the control means.

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

[0014]

EXAMPLES Examples of the present invention will be described in detail below.

The polishing control apparatus 1 shown in FIG. 1 is parallel to a polishing plate 2 having a disc-shaped shaft 2a made of a conductive material such as tin and an upper surface of the polishing plate 2 at a predetermined interval. A jig 5 made up of a rectangular parallelepiped jig 3 made of a conductive material and arranged on the outer sides of the four sides of the rectangular jig 3, and a jig 5 comprising a conductive material prismatic jig 4 and the lower surface of the square jig 3. And a magnetic head assembly 6 as a rectangular parallelepiped object whose lower surface is brought into 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.
And an arbitrary number of electromagnetic conversion elements 9 each having a pole portion 9a provided inside the 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. And 10 are provided.

The polishing control device 1 further detects the conduction between the conductive pattern 10 arranged at both corners of the upper surface of the prismatic jig 4 and the polishing platen 2, and outputs a detection result as an optical signal. Detecting means 11 and each conduction detecting means 1
1, a pair of light receiving means 12 for receiving the optical signal from 1, and a control for processing the output signals of the respective light receiving means 12 and sending out a control signal for rotationally driving the jig 5 and the polishing board 2 based on the output signals. It has a means 13 and a rotation driving means 14 which takes in a control signal and drives and stops the polishing board 2 based on the control signal.

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

Therefore, the jig 5 is rotated by the linear drive of the polishing disk 2 and the arm 3b which are rotationally driven, 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. I am trying.

Here, the pole portion 9a of the electromagnetic conversion element 9 in the magnetic head assembly 6 and the conductive pattern 10 are formed.
The arrangement and dimensional relationship with and will be described with reference to FIGS.

Two conductive patterns 10 are formed at each corner of the insulator 8 in total, four in total. The conductive pattern 10 includes first and second patterns 15 and 16 formed at a thickness of about 1000 to 3000 angstroms by a thin film technique using a conductive material such as Ti, Cr, Fe and Ni alloys with a minute interval. Formed and equipped.

The first and second patterns 15 and 16 are pin contact patterns 15a and 16a each having a length of 400 μm and a width of 250 μm in FIG.
Width 1 derived from 5a, 16a to near the lower surface of the insulator 8
It is provided with 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 to fourth patterns 17 and 18 are formed at the other corner.

Further, pin contact patterns 17a, 18a and detection patterns 17b, 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 about 1 μm.
They are formed with a difference of m, L1 and L3, L2 and L4
Are designed and arranged at the same distance as seen from the electromagnetic conversion element 9.

The conduction detecting means 11 is fixedly arranged on the jig 5 by a magnet or the like, is led out from the inside of the conduction detecting means 11, and passes through the side of the prismatic jig 4.
Further, each of the pin contact patterns 15a, 16a, 17
contact pins 1 made of a conductive material that are brought into contact with a and 18a
4 corresponding to 9, 20, 21, 22 and the contact pins 19, 20, 21, 22 arranged in the detecting means 11, respectively.
Individual detection circuits (shown in FIG. 5) 23, 24, 25, 26
And light-emitting elements 27, 28 such as four LEDs, which are connected to the output sides of the detection circuits 23, 24, 25, 26 and are arranged on the upper surface of the detection means 11 in a radial direction from the center of rotation. , 29, 30 are provided. The ground terminal 31 of the detecting means 11 is maintained at the ground level through the slider portion 7, the prismatic jig 4, and the square jig 3 by connecting the 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 (same for 24, 25 and 26). This detection circuit 23
Is a C-MOS in which a clock (CLK) terminal is connected to the contact pin 19 and an output terminal is 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 source (Vcc) such as a battery, a capacitor C connected between the clock terminal and ground, and a flip-flop 33 Set terminal (S)
It has 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 resistor 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 on the continuity detecting means 11 are arranged.
The light receiving elements 3 are arranged in a row in the radial direction with the rotating shaft 3a as a center so as to receive an optical signal from 30 (shown in FIG. 5).
4, 35, 36, 37 are provided.

Therefore, the light emitting elements 27, 28, 29, 30
The respective optical signals from the optical signals are opposed to each other each time the jig 5 is rotated, and are incident on the respective light receiving elements 34, 35, 36, 37,
Each is converted into an electric signal.

The control means 13 controls the respective light receiving elements 34, 3
5, 36 and 37, a signal processing unit 38 that takes in the signal, processes the signal and outputs the signal, and a control signal for driving or stopping the rotation driving unit 14 based on the signal 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-mentioned structure will be described.

As shown in FIGS. 1 to 3, with the magnetic head assembly 6 mounted on the lower surface side of the prismatic jig 4 in contact with the upper surface of the polishing platen 2, the polishing platen 2 is rotated by α by the rotation driving means 14. Direction, the jig 5 is moved to the arm 3
It is linearly driven in the β direction by b. Then, the jig 5
Performs a rotary motion, and the lower surface side of the magnetic head assembly 6 and the lower end side of the pole portion 9a are gradually polished. When the polishing dimension of 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 and the polishing platen 2 come into contact with each other, whereby the contact pattern of the second pattern 16 is made. The contact pin 20 that is 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 plate 2, the slider portion 7, the prismatic jig 4, and the square jig 3 are all made of a conductive material, so that they are in a conductive state, and the square jig 3 and the ground terminal 31 are grounded. Because it is connected by the line 32.

When the contact pin 20 and the ground terminal 31 are brought into conduction, an input signal is input to the clock terminal of the flip-flop 33, which causes the output terminal of the flip-flop 33 to change from its previous "high" state to "low". Turn into a state,
A current flows through the light emitting element 28, and the light emitting element 28
An optical signal indicating conduction between the pattern 16 and the polishing plate 2 is radiated upward.

In this case, the conduction detecting means 11 including the light emitting element 28 is rotating together with the jig 5, but the light emitting element 2
Since the light receiving element 35 of the light receiving means 12 is fixedly arranged above the rotation region of 8, the optical signal from the light emitting element 28 is periodically incident on 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 progresses, 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 contacts the polishing platen 2, and the conduction detecting means 11,
An electric signal is sent to the signal processing unit 38 through the light receiving means 12. (In some cases, electric signals may be simultaneously sent from the left and right light receiving elements 35, 37 and 36, 38.) In the signal processing unit 38, polishing is performed based on the difference in signal input time from the conductive patterns 16, 15. Calculate the polishing rate on the way,
Further, the polishing inclination during polishing is calculated from the difference in the signal input time from the conductive patterns 16 and 18, and the processing result is calculated by 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 the desired throat height LX, for example, a control signal for stopping the polishing machine 2 is applied to the rotation driving means 14.
Send to. As a result, the rotation driving means 14 stops the polishing board and stops polishing. The signal processing unit 38 will be described below.
I will explain about the calculation method in.

Polishing size L1 of the conductive patterns 15 and 16,
Let h be the difference between L2. Further, it is 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 designated as T1, T2 and T4. Then,
The polishing rate Δh and the polishing gradient Δd are Δh = h / (T1 −T2) (μm / sec) Δd = (T4 −T2) Δh / L (μm).

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

In the above-mentioned operation, by appropriately setting the values of the first resistor R1 and the capacitor C, the disturbance noise can be blocked and the detection sensitivity of the continuity detecting means 11 can be improved.

Further, 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 dimension control of the pole portion 9a is more accurate as compared with the conventional example using the conductive brush. It becomes possible to do it.

Moreover, 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 operations. The present invention can be modified in various ways within the scope of the invention in addition to the embodiments described above.

For example, in the above-described embodiment, each contact pin has a structure of one, but each of the contact pins has a structure of two, and by making contact with different positions of each conductive pattern, each conductive pattern is formed. The contact with can be made more reliable.

Further, instead of using the contact pins to connect the conductive pattern and the conductive detecting means, a conductive wire may be bonded.

[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 can be performed accurately in parallel. It is possible to provide a polishing control device that can be performed and can contribute to improvement of work efficiency and productivity.

[Brief description of 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 plate, a jig, a magnetic head assembly, a detecting means, and a light receiving means of the same device.

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

FIG. 4 is an enlarged plan view of an electromagnetic conversion element and a conductive pattern according to this embodiment.

FIG. 5 is a block diagram of a detection unit and a light receiving unit of this embodiment.

FIG. 6 is a specific circuit diagram of the detecting means and the light receiving means of this embodiment.

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

[Explanation of symbols]

1 Polishing control device 2 polishing machine 5 jigs 6 Magnetic head assembly 10 Conductive pattern 11 Continuity detection means 12 Light receiving means 13 Control means 14 Rotational drive means

Claims (7)

[Claims] 1. An arbitrary number of conductive patterns having, at their ends, an arbitrary number of electromagnetic conversion elements having a pole portion and a yoke portion, a polishing region facing the lower end side and different distances from the lower end surface. A thin film magnetic head assembly supported by a rotationally driven conductive jig, a polishing region of the thin film magnetic head assembly rotationally driven and supported by the jig, and a conductive material for contact polishing the conductive patterns. Of the polishing plate, a light emitting element which is arranged on the jig, detects stepwise conduction between the polishing plate and each conductive pattern, and sends out the detection result as an optical signal, and the optical signal of the light emitting element A signal for calculating the polishing rate and the polishing inclination based on the signal from the conduction detecting means, which has a light receiving element which receives by contact and sends out a signal according to the stepwise conduction of each of the conductive patterns. Processing hand Polishing control comprising: a step and a control means for controlling the driving of the jig and the polishing disk based on the calculation result of the signal processing means and polishing the thin film magnetic head assembly to a desired throat height dimension. apparatus. 2. The polishing control apparatus according to claim 1, further comprising a jig having a mechanism for connecting the conductive pattern and the conduction detecting means through a contact pin. 3. A flip-flop circuit for detecting a voltage drop due to conduction to be a conduction detection signal is provided for each of both end portions of the thin film magnetic head assembly, and the conduction detection signal is used as an optical signal during polishing rotation. 2. The polishing control apparatus according to claim 1, further comprising the conduction detecting unit including four light emitting elements and four light receiving elements for transmitting to an external signal processing unit. 4. The polishing control according to claim 1, wherein the jig is provided with a mechanism for raising two contact pins on the pattern in order to confirm reliable conduction between the pattern and the contact pin. apparatus. 5. The conductive pattern has a tip shape that allows good conductive contact with a polishing plate, and has a shape required to stand two contact pins. Item 1. The polishing control device according to item 1. 6. The thin film magnetic head assembly having conductivity and the head support having conductivity are used to detect conduction between the conductive pattern and the conductive polishing plate, and the conductive pattern and the head support. The polishing control device according to claim 1, wherein continuity between the two is detected. 7. The conductive pattern is connected to the continuity detecting means by bonding a conductive wire.
The polishing control device described.