CN102280112B - Thermal flying-height control slider for hard disk drive - Google Patents

Abstract

The invention provides a thermal flying-height control slider for a hard disk drive. In the thermal flying-height control slider, according to a principle that the read-write magnetic head area of the slider can be subjected to thermal expansion so as to further reduce flying height by electrifying a write coil in a magnetic head write process, a microheater is additionally arranged at a selected middle position of a read-write magnetic head on the hard disk slider, and a unique and efficient W-shaped microheater structure is designed. By means of the structure, the magnetic reading head can obviously move downwards in a read operation process, the flying height of the hard disk magnetic head in the read operation process is decreased, and the precision and the efficiency of data read are increased.

Description

A thermal fly height control slider for hard drives

technical field

The invention belongs to the technical field of computer storage devices, and in particular relates to a thermal flying height control slider, which can effectively reduce the flying height of a magnetic head during a hard disk data reading operation, so as to improve the storage density of the hard disk.

Background technique

In the hard disk drive, with people's pursuit of large-capacity data storage, it is very important to greatly increase the storage capacity of the hard disk by reducing the information bit area of the recorded data within a relatively limited disk area. However, based on the fact that when the data bits recorded on the hard disk do not reach a certain level of magnetic force, the inductive magnetic head cannot read the information bits. Therefore, while the information bit area is small, the flying height of the magnetic head of the hard disk must be reduced, thereby increasing the magnetic coupling between the magnetic head and the information bit, so as to facilitate accurate data reading and writing. The reduction of the fly height of the hard disk head is an effective measure to increase the storage density of the hard disk, but at the same time, it also brings the possible head-disk collision, which is also one of the direct reasons that hinder the further reduction of the fly height.

At the same time, both in terms of technology and stability, the magnetic head must be reduced accordingly to achieve light weight and miniaturization. In order to ensure that such a small read-write head can run stably on the surface of the disk platter, the read-write head is actually embedded in a relatively large slider through semiconductor manufacturing technology.

By designing the air bearing surface of the slider, the slider can be controlled at an appropriate flying height to meet the requirements for accurate reading and writing of data. With the development of hard disk technology, the shape and size of the air bearing slider have undergone great changes. In 1975, the size of the standard mini slider was 4×3.2×0.86mm, and the shape of the air bearing surface was also very simple. The size of the latest femto slider invented in 2003 is 0.85×0.70×0.23mm, and the shape of the air bearing surface is very complicated. Under the condition of the high-speed operation of the disk, the slider is supported by the suspension component and supported by the upward force generated by the principle of aerodynamics to run stably on the surface of the disk. Currently using femto sliders, the flying height of the magnetic head has been reduced to below 10nm. In order to further reduce the flying height of the magnetic head, factors such as thermal expansion, which have nanometer-level effects on the flying height, have to be considered.

Existing hard disk drives have adopted a separate dual-head structure for reading and writing, and their reading and writing principles are completely different. During the writing operation of the magnetic head, the heat generated by the energization of the write coil and the heat of the surrounding environment will cause the thermal expansion of the read-write head, and then affect the distance between the read-write head and the disk in the head-disk interface. The read operation is to read data through the magnetoresistance effect, without additional power supply, and will not cause thermal expansion of the magnetic head. Due to the downward displacement of the write head caused by the thermal expansion of the write coil during the write operation, considering this displacement, a sufficient margin must be maintained during the head flight to avoid the head-disk interface during the write operation. collision. The maintenance of the margin makes the flying height of the magnetic head slider higher than the minimum flying height that can be achieved, which seriously affects the accuracy and efficiency of the hard disk head for data reading, and thus makes it impossible to further improve the storage capacity of the hard disk using traditional disk sliders. capacity.

Therefore, in order to solve this problem, D.W.Meyer proposed a thermal fly height control slider in 1999, and the patent application number is U.S. Patent 5 991 113. The design uses a microheater, a small heater with high input power and precise control. However, most of the micro-heaters in the existing thermal fly height control slider structure adopt a completely symmetrical structure with uniform line width, which makes the thermal deformation generated in the region evenly distributed around, not only vertically along the disk surface Downward thermal deformation also has thermal deformation vertically upward along the disc surface. The upward thermal deformation not only has no positive effect on improving the read-write performance and storage capacity, but will cause instability of the read-write head and affect the improvement of read-write performance and storage capacity. In this background, the present invention proposes a novel thermal fly height control slider to solve this problem and further reduce the flying height of the magnetic head slider.

Contents of the invention

The object of the present invention is to provide a thermal fly-high control slider structure for a hard disk drive, by reducing the upward thermal deformation and increasing the downward thermal deformation during the data reading process of the magnetic head, so that the hard disk will The magnetic head flies at the lowest possible height, which improves the stability, read and write performance, data reading efficiency and storage capacity of the read and write magnetic head.

A thermal fly height control slider for a hard disk drive, comprising a slider substrate, an air bearing surface is provided on the surface of the slider substrate close to the drive disk, a slider gasket is provided on the side of the slider substrate, and the slider The top protective layer, the upper protective layer of the reading head and the lower protective layer of the reading head are arranged in sequence in the gasket. The reading head is arranged between the upper protective layer and the lower protective layer of the reading head. The writing coil is wound on the top protective layer. A micro heater is placed between the protective layer and the upper protective layer of the read head.

The micro-heater includes a W-shaped substrate and a coil wound on it, and the tip of the W-shaped substrate is close to the air bearing surface.

The coil density wound on the W-shaped substrate changes from small to large in the direction from the open end of the W-shaped to the tip.

The middle protruding portion of the W-shaped base body is in the shape of a smooth arc and is lower than the height of both sides.

Technical effect of the present invention is embodied in:

When a certain current is applied to the coil wound on the micro heater, corresponding heat will be generated in the heater, and then thermal expansion will occur, that is, the magnetic head will have a certain displacement in the direction of the disk, reducing the flying height of the magnetic head .

Further, the present invention adopts a W-shaped heater, because the coil line density of the V-shaped protruding part is larger than that of other parts, thereby generating more heat, so that the downward displacement is relatively large, while the coil in the middle of the two V-shaped The arc area is relatively smooth, the linear density is relatively small, and the heat generated is relatively small, so the upward displacement is small. The relationship between the magnitude of the applied current and the displacement can be effectively measured and controlled through precise experimental data, so that the coil current can be turned off during the data writing process, and the current can be applied during the data reading process to make the hard disk head fly as fast as possible during the data reading process. Possibly low height, which improves the speed and efficiency of data reading.

This structure can make the magnetic head approach the disk as low as possible during the data reading process, thereby realizing faster and more accurate track seeking, improving the stability of the operation of the hard disk magnetic head, and improving the efficiency of reading data by the hard disk magnetic head. And because it only adds an accessory device on the basis of the original slider structure, it is easy to manufacture and install.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the slider;

Fig. 2 is a schematic diagram of the local structure of the slider without a micro heater;

Fig. 3 is the partial structure schematic diagram of slide block with micro-heater;

Figure 4 is the specific structure of the micro heater.

Detailed ways

Below in conjunction with accompanying drawing and example the structure of the thermal flying high control slider in the present invention is described in further detail.

Fig. 1 is an overall structural diagram of an existing slider, Fig. 2 is a partial structural diagram of an existing slider without a micro heater, and Fig. 3 is a part of a thermal fly height control slider including a micro heater in an embodiment of the present invention structure diagram. Among them, the larger cube in Figure 1 is the slider substrate, and its upper surface is the air bearing surface, while the smaller cube on the side is the slider gasket, and the magnetic head and the heater are embedded inside the gasket. In Figure 2, two separate protective layers sandwich the read head, and the write head is a helically wound coil, and the ten small circles in the figure are the cross-sections of the helix. In Figure 2, perpendicular to the graph, inward is the direction away from the current track, upward is the direction tangent to the current track, and horizontal is the direction perpendicular to the disk.

As can be seen from the comparison of Fig. 2 and Fig. 3, the main device of the present invention is installed in the middle of the read head and the write head, and a heating device, ie a micro heater, is added in the middle area.

Figure 2 and Figure 3 are schematic diagrams of the design of the thermal fly height control slider, in which a micro heater is newly added between the upper protective layer of the read head and the protective layer of the write head, which is located in the middle of the read head and the write head.

Fig. 4 is the concrete structure of micro heater in the embodiment of the present invention, and the dotted line among the figure has represented the direction with protective layer level, and micro heater comprises a W-shaped substrate, and the lower end of this substrate, i.e. two V-shaped tips The structural part is facing the air bearing surface, and it can be seen from Figure 4 that the middle protrusion of the W-shaped base is smooth and arc-shaped, and is relatively short, and its position is lower than the support structures on both sides of the W-shaped base, while its bottom The two V-shaped protrusions at the end are sharp edges and corners. The energized coil is wound on the W-shaped substrate, and the winding density changes from small to large in the direction from the open end of the W-shaped to the tip. The substrate can be made of photoresist material, which has a high thermal expansion rate and can achieve large deformation while absorbing a small amount of heat, which can achieve the purpose of saving power. At the same time, after the winding coil is energized, it will not generate a magnetic field that interferes with the read-write head. The size and power of the micro-heater can be adjusted accordingly according to the specific slider structure.

W-shaped substrate is the best form, but it is not limited to this form, and can also be designed as U-shaped, V-shaped and so on. The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the content disclosed in this embodiment and the accompanying drawings. Therefore, all equivalents or modifications that do not deviate from the spirit disclosed in the present invention fall within the protection scope of the present invention.

Claims (2)

1. A heat fly high control slider for hard disk drives, comprising a slider substrate, the surface of the slider substrate near the drive disc is provided with an air bearing surface, and the side of the slider substrate is provided with a slider gasket, A top protective layer, an upper protective layer of the reading head and a lower protective layer of the reading head are provided in sequence in the slider gasket, a reading head is arranged between the upper protective layer and the lower protective layer of the reading head, and a write coil is wound on the top protective layer, and It is characterized in that a micro heater is placed between the top protective layer and the upper protective layer of the read head; the micro heater includes a W-shaped substrate and a coil wound thereon, and the tip of the W-shaped substrate is close to the air bearing surface; The coil density wound on the W-shaped substrate changes from small to large in the direction from the open end of the W-shaped to the tip. 2. The thermal fly height control slider according to claim 1, characterized in that, the middle protrusion of the W-shaped base body is in the shape of a smooth arc and is lower than the height of both sides.

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