CN1758342A - Magnetic head folding sheet combination, magnetic disk driver and flying height adjusting method and system thereof - Google Patents

Abstract

The present invention discloses a head-fold assembly, comprising a head, a cantilever for supporting the head, a flying height adjusting device for adjusting the flying height of the head; and a flexible cable for electrically connecting the head and the flying height adjusting device. In the present invention, the flying height adjusting device comprises at least one piezoelectric sheet disposed between the head and the cantilever. The head-fold assembly further comprises an anisotropic conductive film for connecting the flying height adjusting device to the cantilever and the flexible cable. The present invention also discloses a hard disk drive structure using the head-fold assembly, and a method and system for performing flying height adjustment using the same.

Description

Magnetic head flap assembly, magnetic disk drive and its flying height adjustment method and system

technical field

The invention relates to a magnetic head flap assembly and a disk drive with good flying height (FH) adjustment capability, and also relates to a method and system for adjusting the flying height.

Background technique

A data storage system, such as a magnetic disk drive, usually includes one or more magnetic disks driven by a spindle motor to rotate at a certain speed, and one or more information storage heads ( commonly referred to as heads). The magnetic head includes a supporting surface facing the surface of the magnetic disk, such as an air bearing surface (ABS). As the disk rotates, the air pressure between the disk and the air bearing surface increases, creating a lift that lifts the head up and flies over the surface of the disk.

As is well known, each of the magnetic heads is mounted on a suspension (suspension), and the suspension is supported by a driving arm (the suspension with the magnetic head is called a head gimbal assembly (HGA). The driving arm is movable And is controlled by the voice coil motor (voice coil motor, VCM).However, the flying height of the magnetic head is very easy to change due to the following reasons: 1. The magnetic disk suspended at high speed; 2. The tolerance of the air bearing surface of the magnetic head (tolerance); 3. The static posture of the cantilever. And the change of flight height has greatly affected the performance of disk drive. That is, if the flight height is too high, it will affect the magnetic head to read or write data from the disk; on the contrary, if the flight height is too high Low, the magnetic head may scratch the disk when it is impacted, thereby damaging the magnetic head and/or the disk.In today's disk drive industry, with the rapid increase in disk drive capacity, the track pitch and track width of disk drives It becomes narrower and narrower, and correspondingly, the flying height of the magnetic head becomes lower and lower. In this way, it becomes more and more important to control the dynamic flying height of the magnetic head.

In order to meet the above needs, US Patent No. 5,611,707 discloses a device for controlling the dynamic flying height of a magnetic head. Referring to FIG. 1 , the disk drive includes a disk 100 and a HGA 120, wherein the disk 100 rotates around a spindle motor 110 (spindle motor) at high speed, and the HGA 120 includes a magnetic head flying on the surface of the disk 100. A fly height controller 130 for controlling the dynamic fly height of the magnetic head is mounted on the HGA 120 . Referring to FIG. 2 , the flying height controller 130 includes a base 131 and a movable aerodynamic element 132 . The aerodynamic element 132 can rotate along the edge 135 of the base 131 and the movable aerodynamic element 132 . The aerodynamic element 132 is movable from a closed position parallel to the base 131 to an open position perpendicular to the base 131 . When in the closed position, the fly height control 130 does not affect fly height control. When in the open position, the fly height controller 130 will depress the HGA 120, correspondingly, lowering the fly height of the head.

However, the fly height adjustment capability of the fly height controller 130 has a limitation that the fly height can only be lowered and cannot be increased. In practice, however, it is necessary to increase the fly height to compensate for the instability of the manufactured head and head gimbal combination. In addition, because the flying height controller 130 is installed on the HGA 120, the weight of the HGA will increase, and the increase in weight will greatly affect the performance of the HGA 120, such as resonance performance (resonance performance). ) and shock performance. At the same time, because the flying height controller 130 is far away from the magnetic head, its adjustment accuracy is quite limited. Finally, because the fly height controller 130 has a complex structure, its manufacturing process is quite time-consuming and labor-intensive.

Therefore, it is necessary to provide a head gimbal assembly with a flying height adjustment device and a disk drive including the same to overcome the disadvantages of the prior art.

Contents of the invention

Based on the deficiencies of the prior art, the main purpose of the present invention is to provide a head gimbal assembly capable of good flying height adjustment, a hard disk drive, and a method of using the same for flying height adjustment.

Another object of the present invention is to provide a system for dynamically adjusting the flying height of the magnetic head.

In order to achieve the above object, the present invention discloses a head gimbal assembly comprising: a magnetic head, a suspension for supporting the magnetic head, a flying height adjusting device for adjusting the flying height of the magnetic head; A flexible cable that is permanently connected to the magnetic head and the flying height adjustment device. In the present invention, the flying height adjustment device includes at least one piezoelectric sheet placed between the magnetic head and the suspension. The HGA further includes an anisotropic conductive film (ACF) for connecting the flying height adjustment device with the suspension and the flexible cable.

In the present invention, the piezoelectric sheet is a piezoelectric film sheet, a piezoelectric ceramic sheet or a relaxor ferroelectric ceramic (PMN-Pt) piezoelectric sheet, which may be a single-layer piezoelectric sheet or a multi-layer piezoelectric sheet. In one embodiment, the piezoelectric sheet is bonded to one or both sides of the cantilever tongue region of the cantilever member. Furthermore, at least one slot is formed in the region of the cantilever tongue of the cantilever member.

A method for adjusting the flying height with the combination of the aforementioned magnetic head flaps, comprising the steps of: (1) rotating a magnetic disk, the magnetic disk is used to store information; (2) reading the information through the magnetic head; (3) when the magnetic disk rotates, exciting Piezoelectric sheet to control the height of the head relative to the disk.

A hard disk drive of the present invention includes: a magnetic disk for storing information and a combination of magnetic head flaps. The magnetic head flap assembly includes: a magnetic head flying on the magnetic disk, a suspension for supporting the magnetic head, a flying height adjustment device for adjusting the flying height of the magnetic head, and an electrical connection between the magnetic head and the flying height. Flexible cable for adjustment unit.

A system for dynamically adjusting the flight height of the present invention, comprising: (1) a servo control system; used to pick up a position error signal (position error signal, PES) and divide it into two-way PES signals; (2) a voice coil motor controller (VCM controller); used to receive a PES signal to control the voice coil motor driver (VCM driver), thereby driving the voice coil motor to adjust the head position; (3) Flying height adjustment counter; used to receive another PES signal, and pass Comparing the signal required by the servo control system to calculate the required flying height adjustment, and then output a driving voltage; (4) piezoelectric operation driver; receive the driving voltage and apply it to the flying height adjustment device to change the magnetic head flight altitude.

Compared with the prior art, firstly, because the present invention does not need to provide a complex flying height adjustment device on the HGA, it can reduce the weight of the HGA, and there is no need to worry about the anti-vibration performance of the HGA . In addition, other properties of the HGA, such as resonance, will not be affected.

In addition, since the flying height adjusting device provided by the present invention is a piezoelectric sheet arranged under the magnetic head, the flying height of the magnetic head can be adjusted more precisely. Furthermore, the present invention can adjust the flying height of the magnetic head in a desired manner. Obviously, the present invention is also easier to implement and less expensive.

In order to make the present invention easier to understand, the specific embodiments of the magnetic head gimbal assembly, the hard disk drive and the flying height adjustment method and system thereof of the present invention will be further described below with reference to the accompanying drawings.

Description of drawings

Fig. 1 is the perspective view of traditional flying height control system;

Fig. 2 is the partially enlarged view of Fig. 1, to show the traditional flying height controller;

3 is a perspective view of the first embodiment of the HGA (HGA) of the present invention;

FIG. 4 is a partial enlarged exploded view of the magnetic head flap assembly in FIG. 3;

FIG. 5 is a partial enlarged view of the assembled magnetic head flaps in FIG. 3;

6 is a cross-sectional view of the head gimbal assembly in FIG. 3 in the microdrive area;

Fig. 7 is a sectional view of an embodiment of the piezoelectric sheet used in the present invention;

8 is a cross-sectional view of another embodiment of the piezoelectric sheet used in the present invention;

9A-9C show three different working states of the piezoelectric sheet used in one embodiment of the present invention;

Figures 10A, 10B, 11A, 11B show two different voltages applied to the piezoelectric sheet;

12A-12C show three different working states of the piezoelectric sheet used in another embodiment of the present invention;

Fig. 13 shows the connection between the flying height of the magnetic head and the camber of the magnetic head;

14 is a partial enlarged exploded view of the second embodiment of the magnetic head gimbal assembly of the present invention;

FIG. 15 is a partial view of the assembled magnetic head gimbal assembly in FIG. 14;

Figure 16 is a cross-sectional view of the magnetic head gimbal assembly in the microdrive area in Figure 14;

17 is a perspective view of a third embodiment of the HGA of the present invention;

FIG. 18 is a partially enlarged and exploded view of the magnetic head gimbal assembly in FIG. 17;

19 is a perspective view of a fourth embodiment of the HGA of the present invention;

FIG. 20 is a partial enlarged view of the magnetic head gimbal assembly in FIG. 19;

21 is a cross-sectional view of the head gimbal assembly in FIG. 19 in the microdrive area;

Figure 22 is a perspective view of the disk drive of the present invention;

Fig. 23 is a system diagram of dynamically adjusting the flight height of the present invention.

Detailed ways

Referring to FIG. 3 , according to the first embodiment of the present invention, a HGA 2 includes a magnetic head 240 , a flying height adjustment device and a suspension 100 .

Referring to FIGS. 3 and 4 , a plurality of electrode contacts 241 are provided on one side of the magnetic head 240 . The flying height adjustment device is actually a piezoelectric piece 30 (PZT piece) with two electrode contacts 301 at both ends. The cantilever 100 includes a load beam 219 , a flexure 217 , a hinge 215 and a base plate 213 . As an embodiment of the present invention, the flexible member 217 is connected to the pivot member 215 , the load bar 219 and the base plate 213 by means of laser welding. In this embodiment, a small protrusion 329 (see FIG. 6 ) and a limiting device 511 are provided on the load rod 219 . Two holes 201 and 203 are respectively formed on the pivot member 215 and the base plate 213 . The hole 201 is used for swaging the HGA 2 and the driving arm (not shown), and the hole 203 is used for reducing the weight of the suspension 100 . Also referring to FIGS. 3 and 4 , one end of the flexible member 217 is provided with a plurality of connection contacts 251 for connecting with a control system (not shown), and the other end is provided with a plurality of electrode contacts 351 , 361 . The connection contact 251 is connected to the electrode contacts 351 , 361 through a plurality of cables 210 . In this embodiment, the flexible member 217 also includes a suspension tongue (suspension tongue) 328, and the suspension tongue 328 is used to support the magnetic head 240, so that the bearing force always passes through the small hole on the load bar 219. A protrusion 329 (see FIG. 6 ) is applied to the central area of the magnetic head 240 . In this embodiment, corresponding to the electrode contacts 301 on the piezoelectric sheet 30 , two electrode contacts 351 are provided on the cantilever tongue piece 328 . Meanwhile, corresponding to the electrode contacts 241 on the magnetic head 240 , a plurality of electrode contacts 361 are provided on the cantilever tongue piece 328 .

Referring to FIGS. 7 and 8 , in the present invention, the piezoelectric sheet 30 can be a single-layer piezoelectric sheet 380 or a multi-layer piezoelectric sheet 382 . In one embodiment of the present invention, the single-layer piezoelectric sheet 380 includes a piezoelectric layer 373 , two conductive layers 372 and two bottom layers 371 . The piezoelectric layer 373 is sandwiched between two conductive layers 372 . The two bottom layers 371 are used to support and protect the piezoelectric layer 373 and the conductive layer 372 . In the present invention, the single-layer piezoelectric sheet 380 can be a piezoelectric film sheet, a piezoelectric ceramic sheet or a PMN-Pt piezoelectric sheet. The thickness of the piezoelectric layer 373 is 1-3 μm, the thickness of each conductive layer 372 is less than 1 μm, and the thickness of the bottom layer 371 is between 0.1 μm and several microns. In this way, the total thickness of the single-layer piezoelectric sheet 380 will be very thin. In the present invention, the multilayer piezoelectric sheet 382 includes two or more single-layer piezoelectric sheets 380 connected together (excluding the bottom layer 371 ) and two bottom layers for covering the single-layer piezoelectric sheet 380 371. Every two single-layer piezoelectric sheets 380 of the multi-layer piezoelectric sheet 382 are connected together by epoxy glue or resin 383 . It can be understood that the above approach will increase the bending performance (bending performance) of the piezoelectric sheet 30, thereby not only helping to change the camber of the magnetic head (camber, the curvature in the width direction of the magnetic head is called the camber of the magnetic head), but also making it possible to adjust the camber of the magnetic head. It is easier to adjust the speed and flight altitude. In a preferred embodiment, the thickness of the epoxy glue or resin 383 is less than 5 μm, which will keep the piezoelectric film 30 thin and have good adjustment performance.

Referring to FIG. 4 , two slots 218 are formed on the cantilever tongue 328 for reducing the stiffness of the cantilever tongue 328 . This structure contributes to good flying height adjustment capability when the piezoelectric sheet 30 is bent. Meanwhile, an opening 512 is formed on the cantilever tongue 328 corresponding to the limiter 511 on the load bar 219 . The limiter 511 passes through the opening 512 to prevent the cantilever tongue 328 from moving beyond the limit.

In this embodiment, referring to FIG. 4 , in the assembly process, first, the piezoelectric sheet 30 is bonded to the cantilever tongue 328 through the ACF sheet 70, and correspondingly, the two electrode contacts 351 on the cantilever tongue 328 are connected to The electrode contacts 301 on the piezoelectric sheet 30 are electrically connected to establish an electrical connection between the cantilever tongue 328 and the piezoelectric sheet 30 . Next, the magnetic head 240 is placed on the cantilever tongue 328 , so that the piezoelectric film 30 is clamped between the magnetic head 240 and the cantilever tongue 328 . In the present invention, the magnetic head 240 is partially connected to the cantilever tongue 328 through epoxy glue or adhesive 257 (see FIG. 6 ). At the same time, by connecting the electrode contact 361 on the cantilever tongue 328 and the electrode contact 241 on the magnetic head 240 with a plurality of metal balls 501 (GBB or SBB; gold ball welding or tin ball welding), the magnetic head 240 and the cantilever tongue 328 are electrically connected. sexually connected. In this way, the HGA 2 is formed, as shown in FIGS. 5 and 6 .

9A-9C describe the working principle of the piezoelectric sheet 30 in detail. When no voltage is applied to the piezoelectric sheet 30, the piezoelectric sheet 30 stops at its original position, and the magnetic head 240 maintains its original shape, as shown in FIG. 9A. Referring to FIGS. 10A and 11A, when a positive DC voltage 411 is applied to the piezoelectric sheet 30 with positive polarization, the piezoelectric sheet 30 with positive polarization will be bent due to the Weiss domain effect. Next, as shown in FIG. 9B, since the piezoelectric sheet 30 with positive polarization characteristics is clamped between the magnetic head 240 and the cantilever tongue 328 and the stiffness of the cantilever tongue 328 is low, in this way, the piezoelectric sheet with positive polarization characteristics Under the positive action of 30, the shape of the magnetic head 240 (mainly the crown of the magnetic head) will become positive. On the contrary, referring to FIG. 11B, when the negative DC voltage 411a is applied to the piezoelectric sheet 30 with positive polarization characteristics, under the negative action (negativeaction) of the piezoelectric sheet 30 with positive polarization characteristics, the shape of the magnetic head 240 (mainly Head crown) will become a negative state, as shown in FIG. 9C. 10B and 11A, when a positive DC voltage 411 is applied to the piezoelectric sheet 30 with negative polarization, the piezoelectric sheet 30 with negative polarization will be bent due to the Weiss domain effect. Then, since the piezoelectric sheet 30 with negative polarization characteristics is clamped between the magnetic head 240 and the cantilever tongue 328 and the stiffness of the cantilever tongue 328 is low, like this, in the positive effect (positive effect) of the piezoelectric sheet 30 with negative polarization characteristics action), the shape of the magnetic head 240 (mainly the crown of the magnetic head) will become negative, as shown in FIG. 9C . On the contrary, referring to FIG. 11B, when the negative DC voltage 411a is applied to the piezoelectric sheet 30 with negative polarization characteristics, under the negative action (negative action) of the piezoelectric sheet 30 with negative polarization characteristics, the shape of the magnetic head 240 ( Mainly head camber) will become positive, as shown in FIG. 9B.

In another embodiment, as shown in FIGS. 12A-12C , the piezoelectric sheet 30 can also be installed on the back of the cantilever tongue 328 . In this way, the magnetic head 240 is directly installed on one side of the cantilever tongue 328 and the piezoelectric film 30 is installed on the other side of the cantilever tongue 328 . Similarly, when no voltage is applied to the piezoelectric sheet 30, the piezoelectric sheet 30 will stay at its original position, and the magnetic head 240 will also maintain its original shape, as shown in FIG. 12A. When a positive DC voltage is applied to the piezoelectric sheet 30 with positive polarization, the piezoelectric sheet 30 with positive polarization will be bent due to Weiss domain effect. And because the piezoelectric sheet 30 with the positive polarization characteristic is installed on the back of the cantilever tongue 328 and the magnetic head 240 is installed on the front of the cantilever tongue 328, the cantilever tongue 328 has low stiffness simultaneously, as shown in Figure 12B. In this way, under the active action of the piezoelectric sheet 30 with positive polarization characteristics, the profile of the magnetic head 240 (mainly the crown of the magnetic head) will become a positive state. On the contrary, when a negative DC voltage is applied to the piezoelectric sheet with positive polarization characteristics 30, the shape of the magnetic head 240 (mainly the crown of the magnetic head) will become negative under the negative action of the piezoelectric sheet 30 with positive polarization characteristics, as shown in FIG. 12C. If the piezoelectric sheet 30 has a negative polarization characteristic, its working principle is similar to the above-mentioned principle, which will not be described in detail here. In another embodiment of the present invention, one or both sides of the cantilever tongue 328 can be provided with two or more piezoelectric plates 30, which will improve the ability to adjust the shape of the magnetic head 240 (mainly the crown of the magnetic head) , thereby improving the ability to adjust the flying height of the magnetic head 240 .

FIG. 13 illustrates the relationship between the crown of the magnetic head 240 and its flying height in one embodiment of the present invention. It demonstrates that high camber results in a low flight altitude.

In another embodiment of the HGA of the present invention, as shown in FIG. 14 , the cantilever tongue 328 is divided into two parts: one part is the movable part 703 , and the other part is the fixed part 702 . Two narrow cutouts 298 are formed on the fixing portion 702 , and the small protrusion 329 (see FIG. 16 ) on the load rod 219 is placed between the two narrow cutouts 298 for supporting the fixing portion 702 .

Referring to FIGS. 14-16 , in assembly, firstly, the piezoelectric sheet 30 is bonded to the movable part 703 of the cantilever tongue 328 through the ACF sheet 70 . Next, the magnetic head 240 is placed on the suspension tongue 328 , so that the piezoelectric film 30 is clamped between the suspension tongue 328 and the magnetic head 240 . In this embodiment, the magnetic head 240 is partially bonded to the fixing portion 702 of the cantilever tongue 328 by epoxy glue or adhesive 257'. Similarly, after the above assembly, the electrical connection between the magnetic head 240 , the cantilever tongue 328 and the piezoelectric sheet 30 is established through the metal ball 501 or the ACF sheet 70 .

In another embodiment of the magnetic head gimbal assembly of the present invention, referring to FIGS. 17-18 , the magnetic head gimbal assembly further includes a U-shaped ceramic frame in addition to the piezoelectric sheet 30 provided with two electrode contacts 301 801, the U-shaped ceramic frame 801 is provided with two PZT sheets 803 on both sides. The magnetic head 240 is installed in a U-shaped ceramic frame 801, and the four electrode contacts 241 on it are exposed outside. The two PZT sheets 803 are piezoelectric film sheets or piezoelectric ceramic sheets. Each piezoelectric sheet 803 is provided with two electrode contacts 802 . The cantilever tongue 328 is divided into two parts, one part is the movable part 703', and the other part is the fixed part 702'. Two slots 218' are provided on the fixing portion 702' to reduce the rigidity of the cantilever tongue 328. On the fixed part 702' of the cantilever tongue 328, a plurality of electrode contacts 824 are provided corresponding to the electrode contact 802, and at the same time, a plurality of electrode contacts 351, 361 are provided corresponding to the electrode contacts 301 and 241. In addition, a plurality of connection contacts 251 are provided on the flexible member 217 , one end of which is connected to a control system (not shown), and the other end is connected to the cables 210 , 211 . The connection contact 251 connects the magnetic head 240 , the piezoelectric sheet 30 and the two piezoelectric sheets 803 to a control system (not shown) through the cables 210 and 211 .

In this embodiment, first, the piezoelectric sheet 30 is electrically and physically connected to the movable part 703' of the cantilever tongue 328 through the ACF sheet 70, and correspondingly, the electrode contact 301 and the electrode contact 351 are also connected to each other. Then, the U-shaped ceramic frame 801 is partially connected to the cantilever tongue 328, and a plurality of metal balls (GBB or SBB, not shown) are used to connect the electrode contacts 824, 351 with the electrode contacts 802, 804, thereby connecting The two piezoelectric sheets 803 are connected with the cable 211 . In addition, there are also a plurality of metal balls (GBB or SBB, not shown) connected to the electrode contact 241 and the electrode contact 361 , so as to electrically connect the magnetic head 240 to the suspension tongue 328 .

When power is applied to the piezoelectric sheet 803 through the cable 211, the piezoelectric sheet 803 will expand or contract to cause deformation of the U-shaped ceramic frame 801, and then the magnetic head 240 will rotate along the radial direction of the magnetic disk to achieve good position adjustment. When power is applied to the piezoelectric sheet 30 through the cable 210, the piezoelectric sheet 30 will cause changes in the shape of the magnetic head 240 (mainly the crown of the magnetic head) so as to obtain good flying height adjustment. In the fourth embodiment of the HGA of the present invention, referring to FIGS. 19-21 , the U-shaped ceramic frame 801 with two piezoelectric plates 803 can also be replaced by a metal support base 860 and a piezoelectric unit 850 . The piezoelectric unit 850 includes two piezoelectric film sheets 853 (or piezoelectric ceramic sheets) and a plurality of electrode contacts (not shown) on one side thereof. The supporting base 860 includes a base 861 , a guiding column 862 and a movable piece 865 . The movable piece 865 has two side arms 863 on both sides thereof. In one embodiment of the present invention, the width of the guiding post 862 is narrower than that of the movable piece 865 . The piezoelectric unit 850 is physically connected to the support base 860 by conventional means, such as adhesives. The cantilever tongue 328 of the cantilever 100 is divided into two parts, one part is the movable part 703", and the other part is the fixed part 702". Two slots 218' are provided on the fixed part 702" to reduce the stiffness of the cantilever tongue 328, and the small protrusion 329 (referring to Figure 21) on the load bar 219 is placed between the two slots 218' for to support the fixing part 702".

19-21, in the present invention, after the piezoelectric unit 850 and the support base 860 are combined to form an additional micro-driver, the additional micro-driver is electrically and Physically connected. A parallel gap 313 is formed between the additional micro-driver and the cantilever tongue 328, thereby ensuring the smooth movement of the additional micro-driver. Then, the piezoelectric sheet 30 is connected to the active part of the cantilever tongue 328 by the ACF sheet 70 703" on. Afterwards, the magnetic head 240 is placed on the piezoelectric sheet 30 and the additional micro-actuator, and then electrically and partially physically connected to the movable sheet 865 of the supporting base 860 through ACF or adhesive 257'. The physical connection allows the head 240 to move with the attached micro-driver, while the electrical connection is used to prevent the head 240 from being damaged by electrostatic discharge (ESD).

In this embodiment, four metal balls 501 (GBB or SBB) are used to electrically connect the magnetic head 240 and the two cables 210 . The piezoelectric unit 850 on the cantilever tongue 328 is connected to the cable 211 through ACF or conductive glue through the electrode contacts thereon. Through the cables 210, 211, the connection contacts 251 electrically connect the magnetic head 240, the piezoelectric film 30 and the additional micro-driver with a control system (not shown). When power is applied to the piezoelectric unit 850 through the cable 211 , the piezoelectric unit 850 will expand or contract to deform the supporting base 860 , thereby making the magnetic head 240 rotate along the radial direction of the magnetic disk to achieve good position adjustment. When power is applied to the piezoelectric sheet 30 through the cable 210, the piezoelectric sheet 30 will cause changes in the shape of the magnetic head 240 (mainly the crown of the magnetic head) so as to obtain good flying height adjustment.

In the present invention, after the assembly of the HGA 2 is completed, the HGA 2 and the driving arm 587 are then loaded into the casing 581 and fixed thereto. Other necessary components, such as magnetic disk 583, spindle motor (spindle motor) 585 and voice coil motor (VCM) 914' are also housed in housing 581. Thus, a disk drive is formed, as shown in Fig. 22.

A method for adjusting flying height with the magnetic head flap combination of the present invention comprises the following steps: (1) rotating magnetic disk 583, which is used to store information; (2) reading said information by magnetic head 240; When the magnetic disk 583 rotates, the piezoelectric plate 30 is excited to control the height of the magnetic head 240 relative to the magnetic disk 583 .

Figure 23 illustrates an electrical control loop for fly height adjustment of the disk drive of the present invention. The magnetic head 240 flies over the magnetic disk 583 and reads or writes data information therefrom. A position error signal (position error signal, PES) 990 is picked up by a servo control system (not shown) and split into two signals, ie signals 904 and 905 . Wherein, the signal 904 is sent to a voice map motor controller (VCM controller) 907 for controlling a voice coil motor driver 908 (VCM driver). The voice coil motor driver 908 is used to drive or adjust a voice coil motor (VCM) 909 to adjust the position of the magnetic head 240 . The signal 905 is then converted into a PW50 (50% width of amplitude, 50% amplitude width) signal, and sent into the flight height adjustment counter 910 . The flying height adjustment counter 910 calculates the required flying height adjustment by comparing the PW50 signal required by the servo control system (not shown), and then outputs a driving voltage, which can deform the piezoelectric sheet 30 and change the flying height of the magnetic head 240. high. Then the driving voltage is sent to the piezoelectric operation driver (PZT operation driver) 911 and applied to the piezoelectric sheet 30, so as to perform good flight height adjustment.

The above disclosures are only preferred embodiments of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the patent scope of the present invention still fall within the scope of the present invention.

Claims (14)

1. a magnetic head fold piece combination (head gimbal assembly) comprising:

Magnetic head (slider);

Be used to support the cantilever part (suspension) of magnetic head;

Be used to adjust the fly-height adjustments device of magnetic head flight height (flying height); And

Be used to electrically connect the flexible cable of described magnetic head and fly-height adjustments device.

2. magnetic head fold piece combination as claimed in claim 1 is characterized in that: described fly-height adjustments device comprises at least one piezoelectric patches that places between described magnetic head and cantilever part.

3. magnetic head fold piece combination as claimed in claim 1 is characterized in that further comprising being used for anisotropic conductive film (anisotropic conductive film) that described fly-height adjustments device and described cantilever part are connected with flexible cable.

4. magnetic head fold piece combination as claimed in claim 2 is characterized in that: described piezoelectric patches is piezoelectric membrane sheet, piezoelectric ceramic piece or relaxation ferroelectric ceramic (PMN-Pt) piezoelectric patches.

5. magnetic head fold piece combination as claimed in claim 2 is characterized in that: described piezoelectric patches is individual layer piezoelectric patches or multi-layer piezoelectric sheet.

6. magnetic head fold piece combination as claimed in claim 2 is characterized in that: described piezoelectric patches is bonded in the one or both sides in the cantilever tongue piece zone of cantilever part.

7. magnetic head fold piece combination as claimed in claim 1 is characterized in that: the cantilever tongue piece zone at cantilever part forms at least one slit.

8. the method with the described magnetic head fold piece combination adjustment of claim 1 flying height comprises the steps:

Spinning disk, disk is used for canned data;

Read described information by magnetic head;

When disk rotates, excite piezoelectric patches with the height of control head with respect to disk.

9. method as claimed in claim 8 is characterized in that: described fly-height adjustments device comprises at least one piezoelectric patches that places between described magnetic head and cantilever part.

10. method as claimed in claim 8 is characterized in that: anisotropic conductive film (anisotropicconductive film) is used for described fly-height adjustments device is connected with flexible cable with described cantilever part.

11. a hard disk drive comprises:

The disk that is used for canned data; And

Magnetic head fold piece combination; It is characterized in that described magnetic head fold piece combination comprises:

The magnetic head that on disk, flies (slider);

Be used to support the cantilever part (suspension) of magnetic head;

Be used to adjust the fly-height adjustments device of magnetic head flight height (flying height); And

Be used to electrically connect the flexible cable of described magnetic head and fly-height adjustments device.

12. hard disk drive as claimed in claim 11 is characterized in that: described fly-height adjustments device comprises at least one piezoelectric patches that places between described magnetic head and cantilever part.

13. hard disk drive as claimed in claim 11 is characterized in that further comprising being used for anisotropic conductive film (anisotropic conductive film) that described fly-height adjustments device and described cantilever part are connected with flexible cable.

14. a system that dynamically adjusts flying height is characterized in that comprising:

Servo-control system; Be used for the take-off location error signal (position error signal, PES) and be divided into two-way PES signal;

Voice coil motor controller (VCM controller); Be used to receive one road PES signal and control voice coil motor driver (VCM driver), thereby drive voice coil motor and adjust head position;

Flying height is adjusted counter; Be used to receive another road PES signal, and go out required flying height adjustment, export a driving voltage then by contrasting the needed calculated signals of described servo-control system;

Piezoelectricity operation driver; Receive described driving voltage and it is put on the fly-height adjustments device to change the flying height of magnetic head.

Images