JP2000100104A - Correcting method and device for head supporting elastic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head supporting elastic member correcting method and device which can correct the static attitude of head quickly with high accuracy to have reproducibility, based on a fixed rule and also enable automatic correction thereof. SOLUTION: A supporting end 6 of head supporting elastic member 1 is fixed to the supporting portion 15 and a load beam portion 3 of the head supporting elastic member 1 is held by holding arms 19 and 21. A rotating force of constant drive torque is given at the constant angular velocity to the holding arms 19 and 21 using a rotating actuator 26. Automatic correcting work is realized with higher reproducibility of correction by previously inputting the relationship between the rotating angle and correcting amount of twisting to a computer 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic head for a hard disk drive, a magnetic head for a magneto-optical disk drive,
For a magnetic head for a flexible magnetic disk or the like in which a head is fixed to a head supporting elastic body such as a leaf spring, the head supporting elastic body is deformed so that a displacement error of a head posture can be automatically corrected. The present invention relates to a repair method and a repair device for a head support elastic body.

[0002]

2. Description of the Related Art A magnetic head, which faces or slides in a flying posture with respect to a recording medium such as a disk, is fixed to a head supporting elastic body such as a leaf spring. The initial posture (static posture) of the head supported by the head support elastic body affects recording characteristics and reproduction characteristics when the head faces the disk.

In particular, when the head faces the disk surface in a flying attitude, the static attitude affects the flying attitude of the head on the disk, and the spacing between the recording / reproducing element mounted on the head and the disk is increased. In addition, there is a problem that the head and / or the disk surface is easily damaged by careless contact between the head and the disk.

Until now, the error in the static attitude of the head has not been regarded as a serious problem, and no correction work has been performed to correct the static attitude by deforming and adjusting the head supporting elastic body. . However, as the recording capacity (recording density) of a recording medium such as a disk has rapidly increased, the flying height of the head has been reduced. As a result, the displacement of the static attitude of the head has a significant effect on the spacing and damage to the head. Therefore, in the magnetic head device for high recording capacity described above, when the error of the static attitude of the head is large, the work of correcting the static attitude of the head by manually deforming the elastic body supporting the head is gradually attempted. ing.

[0005]

However, the work of manually twisting or bending the head supporting elastic body by manual work may or may not be properly adjusted due to the manual operation of the operator, resulting in poor reproducibility of the work. . This is because the torsion or bending operation of the elastic body is delicately changed not only by the amount of torsion or bending but also by the rotational speed or torque of the tool for torsion or the like. Therefore, the operation of correcting the static attitude of the head by deforming the head support elastic body so as to be within the allowable range is affected by the skill of the operator, resulting in extremely low work efficiency.

The present invention has been made to solve the above-mentioned conventional problems, and enables a static attitude of a head to be quickly and accurately corrected so as to have reproducibility based on a certain rule, and to enable automation thereof. It is an object of the present invention to provide a method and a device for correcting a head support elastic body.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method of correcting a head supporting elastic body, which comprises fixing a supporting end of a head supporting elastic body supporting a head to a supporting portion and leaving the head supporting elastic body in a free state. A measuring step of measuring the attitude of the head to determine an error amount Y0 of the attitude, and clamping the head support elastic body with a clamping member to correct the error amount Y0;
A correcting step of rotating at least one of the supporting portion and the holding member at a constant angular velocity and a constant driving torque using a rotary actuator to deform the head supporting elastic body, and in the correcting step, Error amount Y0,
The rotation angle X of the support portion and / or the holding member required to deform the head support elastic body by this error amount Y0.
1 is obtained in advance, and the support and / or the holding member are rotated by the rotation angle X1 corresponding to the error Y0.

In the present invention, the head supporting elastic body is twisted or bent at a constant angular velocity with a constant driving torque to deform the head supporting elastic body and correct the static attitude of the head. By deforming the head support elastic body at a constant angular velocity and a constant drive torque, it is possible to have regularity in the amount of bending given from the outside by a clamping member and the amount of correction of the error of the actual static attitude of the head. Corrective work with reproducibility is possible.

The relationship between the rotation angle of the support and / or the holding member and the correction amount of the error of the attitude of the head can be quantitatively controlled by using the following equations. However, the following formulas are not strictly limited to the above formulas.
Including adding or subtracting an equation for correction. That is, the gist is that control is performed in a relationship including at least the following mathematical expressions. The torsional or bending applied to the head support elastic body has directionality, and if one direction is expressed as positive, the other direction becomes negative. The following formula can be applied to any of the above directions, and the formula is represented by an absolute value.

First, in the first deformation correction, the relationship between the error amount (correction target amount) Y0 of the attitude of the head and the rotation angle X1 of the supporting portion and / or the holding member is expressed by the following equation (1).
From the cubic equation of As described above, it is possible to add a quadratic term, a first-order term, and a constant term to this cubic equation.

Next, after deforming the head support elastic body, the head support elastic body is set in a free state, and a second measurement of the attitude of the head is performed. By substituting the head posture change amount Yx obtained as a result of the correction into the above equation 1, a unique constant A1 (n) of the actually corrected head supporting elastic body is obtained, and the constant A1 (n) is obtained for each correction of the plurality of heads. It is preferable that the obtained average value of A1 (n) be a constant A1 in a subsequent correction.

The number of constants A1 (n) for obtaining the average value is preferably 5 or more and 100 or less. If it is less than 5, 1
When the ratio of one abnormal value to the average value increases, and exceeds 100, one abnormal value is involved in setting the next constant for a long time. For example, when the constant A1 (n) is extremely different from the value obtained by the correction before and after that, this is excluded as an abnormal value from the calculation of the average value, and the abnormal value of the constant A1 (n) is determined. When the value continues for a predetermined number of times, it is preferable that the abnormal value is regarded as a normal value, and the constant A1 in subsequent correction is determined based on the abnormal value.

A constant A1 for calculating the average value
(N) is more preferably 5 or more and 30 or less. That is, it is preferable that the average value of the unique constants A1 (n) obtained from 5 or more and 30 or less heads on which the correction work is continuously performed be the constant A1 in the subsequent correction. If the static attitude of the head does not fall within the allowable range in the first correction performed in this manner, it is preferable to perform the second correction work. However, since the head support elastic body is given a twist or bend in the first correction, this second correction must be performed based on a function different from the first, as described below. Is preferred.

For example, after rotating the support portion and / or the holding member by the rotation angle X1, the holding position of the head when the holding member is released and the head supporting elastic body is in a free state is measured. When the attitude of the head is within the allowable range, the correction is completed, and when the attitude does not reach the allowable range, the head supporting member is again clamped by the clamping member to deform the head supporting elastic body in the same direction as the correction. A second correction step is performed, and the rotation angle X2 of the support portion and / or the holding member at this time can be set based on the above equation (2).

Alternatively, after rotating the support portion and / or the holding member by the rotation angle X1, the holding position of the head when the holding member is released and the head supporting elastic body is in a free state is measured. When the posture of the head is within the allowable range, the correction is completed, and when the posture exceeds the allowable range, the head supporting member is again clamped by the clamping member to move the head supporting elastic body in the opposite direction to the correction. A second correction step for deforming is performed, and a rotation angle X2 of the support portion and / or the holding member at this time is set based on the above-described equation (3).

As the constant A used in the second correction step, the constant A1 at the time of the first correction can be used as it is. Alternatively, by substituting the rotation angle X1 in the first correction process and the change amount Yx of the attitude of the head as a result of the actual correction into the above equation 1, the inherent constant A2 of the actually corrected head support elastic body is obtained. Then, the constant A2 is used as the constant A.

Alternatively, the rotation angle X1 in the first correction process and the amount of change Yx in the attitude of the head as a result of the actual correction.
Is substituted into the above equation (1) to determine a constant A2 unique to the head support elastic body that is actually corrected. As the constant A, (A1
+ A2) / 2 is used. If only A1 is used, it does not necessarily match the inherent elastic characteristics due to the internal stress of the individual head support elastic members that are to be corrected for the second time, and the second correction, which is more delicate than the first correction, is performed with a high probability. There are limits to success. Also, when using only A2,
The influence of the inherent measurement error and positioning error of the head support elastic body subjected to the first correction increases. Therefore, by using (A1 + A2) / 2, it is possible to increase the correction completion probability by the second correction.

Further, after the correcting step of rotating the holding member, the holding by the holding member is released, and the process is shifted to the heating step. In the correcting step, the return amount of the head supporting member by performing the heating step is determined in advance. It is preferable to set the rotation angle of the support portion and / or the holding member in consideration of the above. When the heat shock is given by performing the heat treatment after the correction as described above, the static attitude of the head is less likely to change when the temperature changes in an actual use environment. Therefore, by performing the correction in consideration of the return of the static attitude of the head after the heat treatment, a head device excellent in environmental resistance can be completed.

For example, assuming that the rate of return of deformation of the head supporting elastic body after the heating step is k, the rotation angle of the supporting portion and / or the holding member in the first correction step is expressed by the above equation (4). Based on

Further, the head supporting elastic body correcting apparatus of the present invention comprises a supporting portion for supporting a base end of the head supporting elastic body to which the head is fixed, a holding member for holding the head supporting elastic body, and the supporting portion. A rotation actuator that rotates at least one of the holding members to apply torsion to the head support elastic body at a constant angular velocity and a constant drive torque;
An angle detection unit that detects the posture of the head, and a control unit that performs a calculation based on any of the correction methods and controls the rotational drive of the rotary actuator based on the posture of the head detected by the angle detection unit. , Are provided. The use of such a head supporting elastic body correcting apparatus enables the static posture of the head to be corrected quantitatively, at high speed, and with a minimum defect rate.

[0021]

FIG. 1 is a side view showing an apparatus for correcting a head supporting elastic body according to the present invention, and FIG. 2 is a perspective view showing an example of a head supporting elastic body to be corrected by the correcting apparatus. The head supporting elastic body 1 shown in FIG. 2 is for a hard disk drive, and is press-formed with a leaf spring material exhibiting elastic force.

At the front portion of the head supporting elastic body 1, ribs 2 and 2 are bent at both side edges to form a load beam portion 3 having a predetermined rigidity. No ribs 2 are formed at the base end thereof, and a cutout window 4 is formed at the center to form an elastic deformation portion 5. Furthermore, the base supporting end 6
In the hard disk drive, the head support elastic body 1 has the support end 6 fixed together with the mount plate 7 to a head support arm or the like.

A flexure 8 made of a leaf spring material thinner than the head support elastic body 1 is joined to the front end of the load beam portion 3, and a head H is fixed to the flexure 8 by bonding. The head H includes a slider 9 facing the recording medium and a recording / reproducing element 10 having a thin film structure provided on an end surface of the slider 9 on the trailing side. A cable 11 is fixed on the load beam section 3, and a lead of the cable 11 is connected to the recording / reproducing element 1.
0 electrode part.

When the head H is mounted on the hard disk drive, the ABS surface Ha of the head H faces the disk, and the ABS surface Ha is pressed against the disk by the elastic force of the elastic deformation portion 5 with a light elastic force. When the disk rotates, a levitation force acts on the ABS Ha by the airflow on the surface of the disk, and the trailing side end surface on which the recording / reproducing element 10 is provided is inclined toward the disk. The recording / reproducing element 10 performs recording of the magnetic signal on the disk or reproduction of the magnetic signal recorded on the disk in the tilted posture.

In this type of magnetic head device, the ABS H of the head H when the support end 6 of the head support elastic body 1 is fixed and in a free state where the head H is not in contact with a disk in a stationary state. Is referred to as a static posture. In the following correction device and correction method, the load beam 3 is twisted around the center line O with the support end 6 fixed, and the static attitude in the roll direction of the ABS Ha is adjusted (corrected).
I do.

The correction device shown in FIG. 1 is provided with a support portion 15. The support portion 15 is provided with the head support elastic body 1.
Fixing stand 16 for fixing the supporting end 6 and the mounting plate 7
Holding members 17a, 17 for holding the head support elastic body 1 at the end of the elastic deformation portion 5 on the head element support side.
b. The support end 6 of the head support elastic body 1 is fixed to the support portion 15 with the ABS H of the head H facing upward, and measurement and correction are performed.

The leading end of the load beam section 3 of the head support elastic body 1 fixed to the support section 15 is held by a holding member 18. This holding member 18 is a pair of holding arms 1.
9 and 21. The holding arm 19 is obtained by bending a leading end of a sheet metal material, and a holding end 19 a corresponds to a portion of the load beam portion 3 where the ribs 2 and 2 are not formed. The other holding arm 21 is formed of a sheet metal material, and a soft or elastic rotating member 22 such as a tube or a rubber roller formed of a resin material such as vinyl is attached to a tip portion thereof. The rotating member 22 contacts the tops of the ribs 2 and 2 of the load beam unit 3. By using the rotating member 22, when a large number of head supporting elastic members 1 are repeatedly measured and corrected, the portion corresponding to the tops of the ribs 2 and 2 is updated, and the holding force of the holding member 18 fluctuates. Can be prevented. The holding arms 19 and 21 are supported by a holding base 23,
The pair of holding arms 19 and 21 are moved up and down by a cylinder mechanism or the like provided on the holding base 23, so that the holding of the load beam unit 3 and the holding release operation can be repeated.

The holding base 23 is fixed to a rotary shaft 25, and the rotary shaft 25 is driven to rotate by a rotary actuator 26. The rotary actuator 26 includes, for example, a stepping motor and a speed reduction mechanism that reduces the output of the stepping motor. One rotation (360 degrees) of the stepping motor is, for example, 500 steps. By combining this with a reduction mechanism of 1:50, the holding base 23 is rotated by 25000 steps per rotation. By using this rotation actuator 26, the holding base 23 (holding member 18)
At a constant angular velocity and a constant driving torque, the center line O
It can be rotated in both positive and negative directions.

The stepping motor constituting the rotary actuator 26 is feedback-controlled by a motor control device 27. A rotation angle command to the rotary actuator 26 is transmitted from a computer 28 serving as a control unit to the motor control device 27. Given. A monitor 29 is connected to the computer 28.

Angle detection means 31 is provided on the ABS Ha of the head H fixed to the tip of the head support elastic body 1.
Are facing each other. The angle detecting means 31 is a collimator, a laser collimator, a laser reflection type angle measuring device, a laser displacement type angle measuring device, a light reflection type angle measuring device, an interference fringe type angle measuring device, or the like. The posture, in particular, the roll direction inclination posture around the center line O is detected.

A measured by the angle detecting means 31
The attitude of the BS surface Ha is sent to the computer 28 and displayed on the monitor 29, and the image processing by the computer 28 calculates the angular displacement about the center line O of the ABS surface Ha.

Next, a description will be given of a method of repairing the head supporting elastic body 1 using the above-described repair device. FIG. 3 is a flowchart showing the flow of the correction method. As shown in the flow chart of FIG. 3, in step 1 (ST1), as shown in FIG.
Fixed to At that time, the holding members 17a, 17
The load beam portion 3 cannot be held by the holding arm 19 and the holding arms 19 and 21 of the holding member 18, and the head supporting elastic body 1 is in a free state. In ST2, in the free state,
The tilt angle of the ABS Ha of the head H is detected by the angle detecting means 31. Based on this measurement, image processing is performed by the computer (control unit) 28, and the roll inclination angle around the center line O of the ABS Ha is measured.

As a result of the first measurement in ST2 and the image processing by the computer 28, if the inclination posture of the ABS Ha is within a predetermined angle range (permissible range), S
The process proceeds to T3, and the inspection processing of the head support elastic body 1 is completed.

According to the first measurement in ST2, the ABS surface H
When it is determined that the inclination posture of the roll member a in the roll direction is out of the permissible range, as shown in FIG.
7b, the base end side is held, and the load beam portion 3 is held between the holding arms 19 and 21 of the holding member 18. Then, in ST4, the first correction is performed. In this first correction, the holding member 18 is rotated by the rotary actuator 26.
Is rotated, the load beam unit 3 is rotated by an angle X1 in a direction for correcting the attitude error of the ABS Ha, and the load beam unit 3 is twisted.

Thereafter, the holding of the load beam portion 3 by the holding members 17a and 17b and the holding arms 19 and 21 of the holding member 18 is released, and the head supporting elastic body 1 becomes free. In ST5, in the free state, the angle of the inclined posture in the roll direction of the ABS Ha is detected. As a result of this detection, the ABS corrected in the first correction process in ST4
If the correction amount Y1 of the surface Ha is within the allowable range with respect to the posture error amount Y0 measured in the first measurement (ST2), the process proceeds to ST3 to complete the processing.

In the measurement of ST5, when it is determined that the correction amount Y1 by the first correction is out of the allowable range with respect to the error amount Y0, the process proceeds to ST6. S
At T6, ΔY = Y0−Y1, that is, the correction amount of the ABS Ha required in the second correction is obtained. At the same time, it is determined whether or not the absolute value of the correction amount Y1 corrected by the first correction is smaller than the absolute value of the error amount Y0 obtained in the first measurement.

The correction amount Y1 corrected by the first correction
Is determined to be smaller than the absolute value of the error amount Y0 obtained in the first measurement, the second
Shift to the second correction process. In the correction step of ST7, the rotation position of the holding member 18 by the rotation actuator 26 shown in FIG.
a, 17b and the holding arms 19 and 21 hold the load beam portion 3 therebetween. Then, the rotation actuator 26
By rotating the holding member 18 at a constant angular velocity and a constant driving torque by the angle X2 in the same direction as the first correction direction, the head support elastic body 1 is deformed in the direction of increasing torsion.

After the second correction process, the holding member 1
The holding of the load beam portion 3 by the holding members 7a and 17b and the holding member 18 is released, and the second measurement is performed in ST8. When it is determined from this measurement that the attitude angle of the ABS Ha in the roll direction is within the allowable range of the product, it is recognized as a non-defective product, and the process proceeds to ST3 to complete the process. If it is out of the allowable range, it is determined to be defective (ST
9).

If it is determined in ST6 that the absolute value of the correction amount Y1 corrected by the first correction exceeds the absolute value of the error amount Y0 obtained in the first measurement, the second round of ST10 is performed. To the correction process. ST1
0, the rotation actuator 26 shown in FIG.
Is returned to the initial position (angle 0) by the holding members 17a, 17b and the holding arms 19.
And 21 sandwich the load beam portion 3. Then, the holding member 18 is rotated by the rotation actuator 26 at a constant angular velocity and a constant driving torque by the angle X2 in a direction opposite to the first correction direction, and the head support elastic body 1 is deformed in the untwisting direction. Let it.

After the second correction step in ST10, the holding of the load beam portion 3 by the holding members 17a and 17b and the holding member 18 is released, and in ST11, the second measurement is performed. When it is determined from this measurement that the attitude angle of the ABS Ha in the roll direction is within the allowable range of the product, it is recognized as a non-defective product, and the process proceeds to ST3 to complete the process. If it is out of the allowable range, it is determined to be defective (ST
9).

Next, details of the correction process in each step shown in FIG. 3 will be described. According to the correction method of the present invention, the specific correction characteristic of the head supporting elastic body 1 of a predetermined standard, that is, the rotation (torsion) at a constant angular velocity and a constant driving torque by clamping the load beam portion 3 with the clamping member 18 is performed. A relational expression between the rotation angle at the time of giving and the correction amount of the angular attitude of the ABS Ha in the free state after the correction is stored in a table of the computer 28 in advance, and the error amount is corrected from the relational expression. The required torsional rotation angle is determined. (First Correction Step; ST4) In the first correction step of ST4, the rotation angle X1 of the holding member 18 for correction is determined as follows. Head supporting elastic body 1 of a predetermined standard (predetermined shape and size) (AB in assembled state)
A plurality of samples having the S-plane Ha having a posture angle error of 0) are prepared as reference samples. First, the first sample is fixed to the support portion 15 shown in FIG. 1, the load beam portion 3 is held by the holding members 17a, 17b, and the holding member 18, and the holding member 18 is rotated in the forward direction by a predetermined rotation angle (stepping). The motor is rotated by a predetermined number of steps (X1). Then,
The holding members 17a and 17b and the holding member 18 are released from being held, and the amount of change (correction amount) in the angular posture of the ABS Ha is measured. Next, for the second sample, the holding member 18 is used.
Then, the holding member 18 is rotated in the same manner except that the rotation angle X1 is different from the first rotation angle X1, and then the ABS (Ha) in the free state is measured to measure the amount of change (the amount of correction).

FIG. 4 shows the relationship between the rotation angle X1 and the correction amount plotted on the xy coordinates by setting different rotation angles X1 in the positive and negative directions for a plurality of samples.
The inventor has confirmed that the line connecting the plots on the xy coordinates approximates a cubic curve. This cubic curve is expressed as y =
If A1.times.x3, A1 is a constant unique to the head supporting elastic body 1 having a predetermined shape (predetermined standard).
The computer 28 receives a constant A1 unique to the product group.

In the actual correction method, if it is determined in the first measurement in ST2 shown in FIG. 3 that the inclination attitude of the ABS H of the head H is out of the allowable range of the normal value, the error amount is determined. Y0 is detected, and this Y0 is substituted into the cubic expression y = A1 · x3 as a correction target value, that is, the calculation of Expression 1 is performed to obtain the rotation angle X1 of the holding member 18 corresponding to the correction amount Y0. The number of steps of the stepping motor corresponding to the rotation angle X1 is given from the computer 28 to the motor control device 27 as a rotation command, and the load beam unit 3 is twisted by the holding member 18 by the angle X1.

After the above-mentioned correction work is performed on the actual product, the ABS H of the head H is thereafter made in ST5.
The measurement of a is performed. By this measurement, it is possible to know how much the angular posture of the ABS Ha has been corrected as a result of twisting by the angle X1. Therefore, the computer 28 substitutes the torsional rotation angle X1 and the resulting correction amount Y1 into the cubic expression y = A1 · x3, and calculates the constant A1 corresponding to the actual product in reverse.

The inversely calculated constant A1 is represented by A1 in FIG.
(N), A1 (n + 1), A1 (n + 2)... Are stored, an average value of a predetermined number, for example, 10 values is calculated, the average value is set as a new constant A1, and the next correction is made. In the operation, the average value is used as a constant A1 of Equation 1. That is, the average of the ten values of the constant A1 obtained by performing the back calculation for each of the corrections and measurements of ST4 and ST5 is calculated one after another, and this value is sequentially fed back to the next correction, and this is repeated. To go.

The number of constants A1 for obtaining the average value is preferably 5 or more and 100 or less, and more preferably 5 or more and 3 or less.
0 or less is preferable. If the number is less than 5, the influence of the extremely changing constant A1 will have a large effect on the average value, and if it exceeds 30 or 100, the extremely changing constant A1 will always be the average. It is not preferable because it involves the calculation of the value.

When the constant A1 newly calculated based on the measurement in ST5 indicates an extremely abnormal value with respect to the average value, for example, the constant A1 out of the range of ± 20% of the average value appears. In this case, as shown in the lower part of FIG. 5, the abnormal value A1 (S) is not used as the basis for calculating the average value. Specifically, it is stored in a table different from the table for calculating the average value.

However, the abnormal values are A1 (S), A1
When a predetermined number (for example, three or more) continues as in (S + 1) and A1 (S + 2), the average value of the three abnormal values is set as the next correction constant A1. The appearance of such abnormal values is mainly due to the switching of product lots,
In this case, switching to a new constant A1 is performed.
The defective rate can be reduced. The inventor calculates the average value,
As a result of performing correction based on the method of handling abnormal values, the defect rate due to the first correction was several percent. (Second Correction Step (Torsion Increasing Direction); ST7) ST7 is corrected when the correction amount Y1 by the first correction does not fall within the allowable range of the actual error amount (correction target value) Y0 (allowable range). If it does not reach within). At this time, a method of calculating the rotation angle X2 given to the holding member 18 will be described with reference to FIG.

In the first correction method in ST4, the torsion angle (rotation angle X1) given to the head supporting elastic body 1 is changed as shown in FIG.
Are set based on the cubic expression y = A1 · x3 shown by the solid line in FIG. If the characteristic according to this equation is shown, the correction amount Y of the head supporting elastic body 1 is obtained as a result of giving the rotation angle X1.
1 must be within the allowable range of the correction target value Y0. However, the fact that the correction cannot be completed by the first correction means that the head support elastic body 1 is twisted by the rotation angle of X1, and as a result, does not reach the line of the cubic expression y = A1 · x3,
This means that the correction amount remains at the position (i) of Y1 (see FIG. 6) smaller than that.

Therefore, in the present invention, in this case, a cubic expression indicating the relationship between the measured rotation angle x applied to the head support elastic body 1 and the resulting correction amount y is originally a curve passing through the above (i). Assume that (y = A1.x3-E). Assuming that the rotation angle that can reach the original correction target value Y0 in the assumed curve is X2, the correction amount ΔY required by the second correction is Y0−Y1, and this is expressed by the following equation (5). Can be calculated.

[0051]

(Equation 5) Equation (6) is transformed from Equation (5). By substituting the insufficient amount ΔY corrected by one correction and measurement into Equation (6), the rotation of the holding member 18 at the time of the second correction in ST7 is obtained. The angle X2 can be obtained. As A1, the average value used for the first correction described with reference to FIG. 5 is used as it is.

[0052]

(Equation 6) Before performing the second correction, since the rotation angle X1 and the correction amount Y1 of the head supporting elastic body 1 are known in ST4 and ST5, this is converted into a cubic expression y = A1 · x3. By substituting, the constant A2 unique to the head support elastic body 1 can be calculated backward. Therefore, in Equation 6, the rotation angle X2 of the holding member 18 required for the second correction may be obtained using the constant A2 unique to the product instead of the constant A1.

Alternatively, the average value of A1 and A2 A = (A
1 + A2) / 2 may be used instead of A1 in Equation 6. That is, the constant A in Equation 2 may be A1 or A2, but it is preferable that A = (A1 + A2) / 2.

If only A1 is used in determining the rotation angle X2 required for the second correction in ST7, this is an average value used for the first correction and may not be optimal for the second correction. . If only A2 is used, errors in the measurement of the product may be accumulated, and may not be optimal. Therefore, A1 and A2
By using the average value, the optimum correction can be performed, and the defect rate can be reduced.

As a result of experiments conducted by the present inventor, the constant A
When only one of A1 and A2 was used, the failure rate by the second correction was almost 50%, but the average value A =
As a result of using (A1 + A2) / 2, the defective rate was less than 10%. (Second correction process (twist return direction); ST10) ST
The correction of 10 is performed when the correction amount Y1 by the first correction exceeds the allowable range of the actual error amount (correction target value) Y0. At this time, the holding member 18 gives a force to the head supporting elastic body 1 to return the twist.

The rotation angle X2 of the holding member 18 and the untwisting correction of the head supporting elastic body 1 when the head supporting elastic body 1 is first twisted and then rotated in the direction opposite to the first twisting direction. FIG. 7 shows the relationship with the amount ΔY.

FIG. 7 shows that a plurality of arbitrarily extracted head supporting elastic bodies 1 are twisted only once by applying rotation in the positive and negative directions, respectively, and then clamped in a direction opposite to the first twisting direction. The member 18 is rotated to deform the head support elastic body 1 back, and at this time, the relationship between the return rotation angle X2 given to the head support elastic body 1 and the return correction amount (return deformation amount) ΔY at that time Is shown diagrammatically.

In the correction device shown in FIG. 1, when the stepping motor of the rotary actuator 26 performs 25000 steps, the holding member 18 rotates 360 degrees.
The first torsional force is applied to each of the plurality of head supporting elastic members 1 by rotating the head supporting members 1 by 00 steps. After that, a torsional return force in the opposite direction to the above-mentioned torsion is applied to each of the head support elastic members 1. The rotation angle X in the return direction of the holding member 18 at this time
2 was changed for each of the plurality of head supporting elastic members 1, and the return correction amount ΔY with respect to the rotation angle X2 given to each of the head supporting elastic members 1 was measured. The relationship is plotted and connected by a line as shown by the solid line in FIG.

The broken line in FIG. 7 indicates that a plurality of head supporting elastic members 1
Is subjected to the first torsional deformation, the rotation angle X2 of the holding member 18 at the time of the return deformation applied thereafter is changed for each head support elastic body 1, and the return correction amount ΔY of the head support elastic body 1 for each torsional deformation X2. Is plotted and connected by a line. The dotted line in FIG. 7 indicates the relationship between the rotation angle X2 of the return force applied to the head support elastic body and the return correction amount ΔY after the stepping motor is rotated 1500 steps for the first time.

The inventor made a plurality of diagrams relating to the return correction as shown in FIG. 7, and tried to express each diagram in common as a linear function of X2. As a result, the following Expression 7 was found as the closest approximation.

[0061]

(Equation 7) In the above formula 7, X1 is the rotation angle of the bending applied to the head support elastic body 1 for the first time, which is 1000 steps, 1250 steps, 1500 steps, etc. of the stepping motor used to obtain the diagram shown in FIG. Is the angle corresponding to B, C, and D are constants derived from the modified shape of the head support elastic body 1 based on the standard. The specific function of Equation 7 obtained as a result is, for example, as shown in Equations 8 and 9 below.

[0062]

(Equation 8)

[0063]

(Equation 9) The constant A1 is the average value of 10 constants A1 (n) of the constant A1 (n) obtained by back calculation for each head support elastic body at the time of the first deformation correction as in the case of ST7, and the head support here. The average value with the unique constant A2 obtained by back calculation when the elastic body 1 is bent for the first time, that is, A = (A1 + A
2) / 2. Alternatively, A may be A1 or A
May be A2.

In ST10 shown in FIG. 3, the second correction amount ΔY is substituted into the above equation 7, specifically, for example, the equations 8 and 9, and is given to the holding member 18 at the time of the second return bending. The power rotation angle X2 is determined. That is Equation 3.

The rotation angle X2 obtained in this manner, particularly the rotation angle X2 obtained from Equation 3 (specifically, Equations 7 and 8) when A = (A1 + A2) / 2, is used as the head supporting elastic member. As a result of giving the second torsion to No. 1, the head support elastic body 1 determined to be out of the allowable range in the measurement after the first correction (ST5) could be corrected with a probability of 90% or more. (In the case of performing heat treatment) After performing each of the above-mentioned corrections on the head supporting elastic body 1, the head supporting elastic body 1 is mounted on a disk device or the like.
When there is a sudden change in the environmental temperature, the torsional deformation performed for the correction on the head supporting elastic body 1 is returned, and as a result,
An error may again occur in the attitude angle of the ABS H of the head H after the adjustment.

Therefore, it is preferable to perform a heat treatment after the above-mentioned correction to give a heat shock, and in this case, it is preferable to consider a return of the correction amount due to the heat shock at the time of the above-mentioned correction. In the heat treatment, the head H was moved to the flexure 8
It may be performed together with the drying process of the adhesive adhered to the
It may be performed independently of the adhesive drying step.

In the diagram of FIG. 8, the correction amount is shown on the vertical axis. Y0 is a correction target, that is, an error amount of the attitude angle of the ABS Ha detected in the first measurement shown in ST2 of FIG. The line α in FIG. 8 indicates that the head support elastic body 1 is subjected to the heat shock after the first correction to the correction amount Ym, so that the attitude of the ABS Ha is within the correction target Y0 or the allowable range thereof. Shows the case.

As a result of heat shock, ABS surface H
The attitude angle of a returns from Ym to Y0.
Assuming that Y, k shown in the following Expression 10 is the return rate due to the heat shock. This can be determined experimentally from the shape and material of the head supporting elastic body 1 and the heat treatment conditions.

[0069]

(Equation 10) Equation 11 shows the relationship between Ym and Y0 using the return rate k.

[0070]

[Equation 11] Ym shown in the above equation 11 is the first correction target taking into account the return rate k due to the subsequent heat shock. The angle X1 for rotating the holding member 18 to reach the target value Ym is obtained from the cubic curve in FIG. Therefore, Y0 in FIG. 4 may be replaced with Ym, and the rotation angle X1 for that may be obtained. The relational expression is Expression 12.

[0071]

(Equation 12) In the first correction of ST4 shown in FIG.
8 is rotated by a rotation angle X1 based on the above Expression 4, and ST
When the correction amount reached the above-mentioned allowable value of Ym in 2 as a non-defective product, and then heat treatment is performed, the heat treatment results almost coincide with the final correction target Y0. The process is terminated after measuring whether or not Y0 has been reached.

In FIG. 8, β indicates the case where the first correction was made based on the equation 4, but the first correction did not reach Ym. At this time, a difference between the correction value obtained by the first correction and the first target value Ym is obtained, and this difference is expressed by Equation 2 below.
A second correction (ST7) is made as ΔY. Then, the process proceeds to heat treatment.

Alternatively, as shown by γ in FIG.
At the time of the first correction, the return rate k due to heat shock k
Is deformed to an amount that exceeds the first correction target value Ym taking into account the final target value Ym by the second return bending.
It may be set to zero. When such return bending is performed, return in the subsequent heat treatment hardly occurs.

[0074]

As described above, according to the present invention, a head support elastic body for supporting a magnetic head for a hard disk or the like can be corrected with high reproducibility and high accuracy. It is also possible to automate the correction work. Further, by obtaining the constant A1 used for the correction operation from the average value, it is possible to correct the characteristics of the magnetic head with high accuracy even if the bending characteristics vary due to the shape and material of the head support elastic body.

By performing the second correction by increasing the bending or returning the bending, even if the correction does not fall within the allowable value in the first correction, the correction can be surely performed. Further, by adding a heating step and performing correction in consideration of the return characteristic due to heating, it is possible to prevent the magnetic head characteristic from being disordered when used for a long time.

[Brief description of the drawings]

FIG. 1 is an apparatus configuration diagram showing a head supporting elastic body correcting apparatus of the present invention;

FIG. 2 is a perspective view showing an example of a head supporting elastic body.

FIG. 3 is a flowchart showing a method of correcting a head supporting elastic body,

FIG. 4 is a diagram showing a relationship between a rotation angle of a holding member and a correction amount at the time of a first correction;

FIG. 5 is an explanatory diagram of a method of calculating a constant A1 used for a first correction,

FIG. 6 shows a case where the first correction does not reach the target value.
Diagram showing the relationship between the rotation amount of the holding member and the amount of correction in the second correction,

FIG. 7 is a diagram showing a relationship between a rotation angle of the holding member and a correction amount in a second correction when the first correction exceeds a target value;

FIG. 8 is a diagram for explaining a correction in which a heat treatment is performed after the correction in consideration of a correction return by the heat treatment;

[Explanation of symbols]

 H head Ha ABS surface 1 head support elastic body 3 load beam section 6 support end 8 flexure 9 slider 10 recording / reproducing element 15 support section 18 holding member 19, 21 holding arm 26 rotation actuator 28 computer (control section) 31 angle detecting means

Claims (13)

[Claims] 1. A supporting end of a head supporting elastic body supporting a head is fixed to a supporting portion, and a posture of the head when the head supporting elastic body is in a free state is measured to obtain an error amount Y0 of the posture. In the measuring step, in order to correct the error amount Y0, the head support elastic body is clamped by a clamping member, and at least one of the support portion and the clamping member is driven at a constant angular velocity and a constant by using a rotary actuator. Correcting the head support elastic body by rotating the head support elastic body by rotating with a torque. In the correction step, the error amount Y0 and the support portion necessary to deform the head support elastic body by the error amount Y0 are provided. And / or rotation angle X1 of the holding member
The head support elastic body is rotated by the rotation angle X1 corresponding to the error amount Y0. 2. The head support elastic body according to claim 1, wherein a relationship between an error amount Y0 of the attitude of the head and a rotation angle X1 of the support portion and / or the holding member is obtained from a cubic equation of the following equation 1. How to fix. (Equation 1) (However, A1 is a constant peculiar to the head supporting elastic body to be corrected.) 3. After the head support elastic body is deformed, the head support elastic body is set in a free state, and a second posture of the head is set.
The second measurement is performed, and the rotation angle X1 of the holding member in the correction process and the change amount Y of the attitude of the head as a result of the actual correction.
x is substituted into the above equation (1) to obtain a specific constant A1 (n) of the head support elastic body actually corrected, and the average value of A1 (n) obtained for each correction of a plurality of heads is thereafter calculated. 3. The method according to claim 2, wherein the correction is made to be a constant A1. 4. The unique constant A1 obtained from 5 or more and 30 or less heads for which correction work is continuously performed.
4. The method according to claim 3, wherein the average value of (n) is defined as a constant A1 in the subsequent correction. 5. When the constant A1 (n) is extremely different from a value obtained by correction before and after the constant A1 (n), this is excluded from the calculation of the average value as an abnormal value, and the constant A1 (n) is excluded.
5. The head support elastic body according to claim 3, wherein when the abnormal value of (n) is repeated a predetermined number of times, the abnormal value is regarded as a normal value, and the constant A1 in subsequent correction is determined based on the abnormal value. Method. 6. After the supporting portion and / or the holding member are rotated by the rotation angle X1, the holding position of the head when the holding member is released and the head supporting elastic body is in a free state is measured. When the attitude of the head is within the allowable range, the correction is completed, and when the attitude does not reach the allowable range, the head supporting member is again clamped by the clamping member to deform the head supporting elastic body in the same direction as the correction. The head support elastic body according to any one of claims 2 to 5, wherein a second correction process is performed, and a rotation angle X2 of the support portion and / or the holding member at this time is set based on the following Expression 2. How to fix. (Equation 2) (However, when the amount of change in the attitude of the head that can be corrected in the first correction step is Y1, ΔY = Y0−Y1. A is a constant specific to the head support elastic body to be corrected.) Is.) 7. After the supporting portion and / or the holding member are rotated by a rotation angle X1, the holding position of the head when the holding member is released and the head supporting elastic body is in a free state is measured. When the posture of the head is within the allowable range, the correction is completed, and when the posture exceeds the allowable range, the head supporting member is again clamped by the clamping member to move the head supporting elastic body in the opposite direction to the correction. The head support elasticity according to any one of claims 2 to 5, wherein a second correction step of deforming is performed, and a rotation angle X2 of the support portion and / or the holding member at this time is set based on the following Expression 3. How to fix the body. (Equation 3) (However, when the amount of change in the attitude of the head that can be corrected in the first correction step is Y1, ΔY = Y0−Y1. A, B, C, and D are the head supports to be corrected.) It is a constant peculiar to the elastic body.) 8. The head supporting elastic body correcting method according to claim 6, wherein the constant A uses the constant A1 at the time of the first correction as it is. 9. A method of substituting the rotation angle X1 in the first correction step and the amount of change Yx of the attitude of the head as a result of the actual correction into the above-described equation (1), and setting the intrinsic angle of the head support elastic body actually corrected. A constant A2 is obtained, and the constant A2
The method for correcting a head supporting elastic body according to claim 6 or 7, wherein: 10. The rotation angle X1 in the first correction process
And the amount of change Yx of the attitude of the head as a result of the actual correction is substituted into the above equation (1) to obtain a specific constant A2 of the actually corrected head support elastic body, and as the constant A, (A1 + A
The method according to claim 6 or 7, wherein (2) / 2 is used. 11. After the correcting step of rotating the holding member, the holding by the holding member is released, and the process is shifted to the heating step. In the correcting step, the return amount of the head support member by performing the heating step is determined in advance. The method according to any one of claims 1 to 10, wherein the rotation angle of the support portion and / or the holding member is set in consideration of the rotation angle. 12. When the return rate of deformation of the head support elastic body after the heating step is represented by k, the rotation angle of the support portion and / or the holding member in the first correction step is as follows. The method of correcting a head supporting elastic body according to claim 11, wherein the correcting method is based on Expression 4. (Equation 4) 13. A support for supporting a base end of a head support elastic body to which a head is fixed, a holding member for holding the head support elastic, and rotating at least one of the support and the holding member, A rotation actuator that applies torsion at a constant angular velocity and a constant drive torque to the head support elastic body, an angle detection unit that detects the posture of the head, and a head posture detected by the angle detection unit, A head support elastic body correction device, comprising: a control unit that performs a calculation based on the correction method according to any one of claims 1 to 12 and controls rotation driving of the rotary actuator.