WO2009096471A1 - Heat-assisted-type hard disk drive - Google Patents

Abstract

Disclosed is a heat-assisted-type hard disk drive in which an LD module 101 having a built-in LD array element 102 is disposed in a hard disk drive housing 140, and a plurality of channels of the LD module 101 and the same number of flexible optical waveguides 121 are connected one-to-one using optical connectors 111. The optical waveguides 121 are disposed so as to each pass through the surface of one arm 143 or suspension means, and guide light to sliders 142 at the tip ends of the arms 143 or suspension means.

Description

Thermally assisted hard disk drive

The present invention relates to a heat-assisted hard disk drive, and more particularly to a technique that is effective when applied to the configuration of a portion that guides laser light to the information recording medium.

As the technology examined by the present inventor, for example, the following technology is conceivable for a heat-assisted hard disk drive.

With the development of the information-oriented society in recent years, the digitization and high quality of voice and video have progressed, and the amount of Internet data communication has increased remarkably. Along with this, the amount of electronic data stored in servers and the like has increased, and there has been a demand for an increase in capacity of information recording systems. As one of information recording devices, a magnetic disk device mounted on a computer or the like is required to have a high recording density in order to store a large amount of information without increasing the size of the device. Higher density means smaller recording bit size.

In order to realize a high recording density of the magnetic disk device, it is necessary to reduce the distance between the magnetic recording medium and the head and to reduce the crystal grain size of the magnetic film of the magnetic recording medium. In a recording medium, reducing the crystal grain size involves a problem that the particles become thermally unstable. Increasing the coercive force is effective in reducing the crystal grain size and simultaneously ensuring thermal stability. Increasing the coercive force necessitates an increase in the head magnetic field strength necessary for recording. However, it is difficult to increase the coercive force as the recording density increases because the physical properties of the magnetic pole material used for the recording head and the distance between the magnetic disk and the head are limited.

In order to solve the above problems, a hybrid recording technology that combines optical recording technology and magnetic recording technology has been proposed. During recording, the medium is heated simultaneously with the generation of the applied magnetic field to reduce the coercive force of the medium. This facilitates recording on a recording medium with high coercive force, which has been difficult to record due to insufficient recording magnetic field strength with a conventional magnetic head. Reproduction uses the magnetoresistive effect used in conventional magnetic recording. This hybrid recording method is called heat-assisted magnetic recording or optically-assisted magnetic recording.

Here, the heating mechanism using light can use a method of squeezing a laser beam used in conventional optical recording with a lens. Shortening the wavelength of the laser light is effective for reducing the spot size. The minimum spot diameter obtained by condensing the light with the lens is represented by the ratio of the wavelength and the numerical aperture of the lens used for condensing, and the shorter the wavelength, the more advantageous for higher density. However, there is a limit to the increase in density when the spot size is reduced by shortening the wavelength of the laser beam, and a smaller light spot is required for the bit size required for the Tb / in ² class recording density. In order to solve this problem, it is considered to reduce the spot size by using the near-field light by narrowing the distance between the recording medium and the head instead of condensing by a lens.

Thermally assisted magnetic recording using near-field light uses an element (hereinafter referred to as “near-field light generating element”) that has a function of guiding laser light generated by a laser light source to a recording head and generating near-field light. The light spot diameter is converted into a size and shape suitable for recording. As a laser light source, it is suitable to use a semiconductor laser diode (hereinafter referred to as “LD”) that is small and has low power consumption among laser light sources because of the necessity to use it in a package of a hard disk drive.

In heat-assisted magnetic recording, a sufficient light intensity suitable for recording is required, which is the light intensity necessary for heating to reduce the coercive force sufficiently to facilitate the magnetization reversal of the recording medium.

The optical output generated by the semiconductor laser is usually about several tens to a hundred mW in the 780 nm wavelength band and the 650 nm wavelength band, which are the most widespread wavelength bands as current optical recording light sources. By the time the light output reaches the surface of the recording medium, an optical loss occurs, which is about several mW. Even in applications used in a thermally assisted magnetic recording apparatus using a near field that realizes a recording density of Tb / in ² or higher, it is assumed that the same level of light output is required on the surface of the recording medium.

The near-field light generating element is an element that receives light on the surface of the element and generates light having a very small spot size using a surface plasmon resonance phenomenon. At the recording density of Tb / in ² class, the size of 1 bit is several tens of nm, and the size of the near-field light generating element is about several hundred nm.

Since this near-field light generating element is used at the interface with the disk (information recording medium), it is formed on the ABS surface (floating surface) of the slider. Accordingly, one of the key technologies is how to efficiently guide the near-field light generating element to the ABS surface of the slider. Moreover, at the same time, it is required to construct a realistic light guiding system by arranging a light source and an optical component for guiding light in a package on a platform called a hard disk drive.

Optical parts are used to guide the light generated by the LD element to the slider. The light generated by the LD element has an optical loss in the middle, and reaches the recording medium in about several percent of the incident light. Therefore, the LD element is required to have a sufficient light output in consideration of the optical loss that occurs before reaching the recording medium. However, the light intensity that can be generated by the LD element cannot be increased indefinitely, and it must be driven within the light output generated at a constant drive current or power consumption, which is the rating of the LD element.

The optical components that guide the laser light generated by the LD element to the slider are a reflection mirror, a lens, an optical waveguide, and the like. The light generated by the LD element propagates through the optical component arranged in the optical path and reaches the near-field light generating element and the recording medium ahead. The light intensity attenuates while passing through the optical path, and becomes several to several tenths of the light output generated by the LD element. The main causes of attenuation of light intensity are due to absorption loss and scattering loss when propagating through optical components, and misalignment (optical axis misalignment and spot size difference) that occurs when optical components are connected. Coupling loss, etc. These optical losses are collectively referred to as “propagation loss”.

In order to obtain a sufficient light intensity necessary for recording, it is necessary to increase the light intensity of light generated by the LD element or reduce the propagation loss. In order to increase the optical output of the LD element, it is necessary to drive the LD element with a large current, and it is necessary to increase the output of the LD element. However, since there is a limit to the light intensity of the light generated in the LD element, it is not realistic to increase only the light intensity of the LD element. This is because, in general, increasing the output of an LD element entails an increase in the size of the element. The increase in size not only causes a significant increase in power consumption and heat generation of the LD element, but also makes it difficult to generate short pulse light necessary for high-speed writing.

Therefore, it is one of the key technologies to efficiently guide the light generated from the LD element to the tip of the head, that is, to reduce the propagation loss. By installing the LD element as close to the head as possible, the propagation loss can be reduced. There is a possibility that a light guide system can be realized by arranging an LD element on or near the slider at the tip of the head.

However, the arrangement of the LD elements described above can reduce propagation loss, but has the following problems.

Normally, there are as many magnetic head sliders as there are magnetic heads in a plurality of magnetic heads of a hard disk drive. Therefore, there are as many magnetic recording elements as the number of sliders. Therefore, in order to realize heat-assisted recording in a hard disk drive, it is necessary to supply light to each slider, and LD elements serving as light sources having the same number as the number of sliders are required. Therefore, mounting the LD element on the magnetic head or slider requires parts cost and mounting cost proportional to the number of heads, and if the number of magnetic heads is large, the cost corresponding to the number of units is required.

In a hard disk drive with a size of 2.5 inches or more, the number of magnetic heads is as large as four or more. Therefore, if the heat assist method is to be realized in a relatively large hard disk drive such as 2.5 inches or 3.5 inches, the number of necessary light sources increases and the cost increases.

In addition to the increase in simple component cost and mounting cost, the yield of integrated components including the magnetic head (called head gimbal assembly or head stack assembly) deteriorates by integrating many components on the slider. The problem also arises. The magnetic head slider is an expensive part of the hard disk drive, and it is difficult to realize a heat-assisted hard disk drive unless the slider part can be simply assembled without waste.

As a method other than mounting the LD element on the magnetic head slider, the LD element is arranged in a portion other than the slider in the hard disk drive housing, and the light is guided to the tip of the magnetic head mounted on the slider using an optical component. A method is conceivable. In this method, the number of components used from the LD element serving as the light source to the slider, the near-field light generating element beyond that, and the information recording medium where the final light reaches is increased, and the optical distance is also increased. , Propagation loss increases.

In addition, the LD element as a light source is generally supplied in a bare chip state or mounted in a module such as the TO-CAN standard and handled, for example, in units of module packages. When handled in a bare chip state, it is suitable for an application in which an LD element is directly mounted to form an integrated component. Mounting with a bare chip is advantageous for miniaturization of integrated components. However, in the case of a bare chip, since the element is fixed with solder or an adhesive, the mounting process is often complicated, and once mounted, it cannot be separated into elements again. This causes the same problems of increase in mounting cost and deterioration in yield of integrated components as described above. Therefore, in a hard disk drive having a large number of magnetic head sliders, when an LD element is arranged in a drive excluding the slider part, the LD element is in the state of an LD module mounted in the module in consideration of the yield of integrated components. It is more convenient to be treated.

However, although the size of the bare chip of the LD element is several hundred μm, the LD module is as large as several mm to several cm. Hard disk drives become thinner as they become smaller, and the space available for 2.5-inch drives is several millimeters in both the thickness and width directions. Therefore, in order to install the LD modules in the space inside the housing of the hard disk drive, an arrangement space corresponding to the number of LD modules is required in the hard disk drive, which is practically impossible.

Accordingly, one object of the present invention is to provide a technology capable of realizing space saving and cost reduction in a heat-assisted hard disk drive.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

Of the embodiments disclosed in the present application, the outline of typical ones will be briefly described as follows.

In other words, the heat-assisted hard disk drive according to the representative embodiment has a laser module containing a semiconductor laser array element arranged in the housing of the hard disk drive, and a plurality of channels of the semiconductor laser array element and a flexible number of channels equal to the number of channels. Optical waveguides are connected one by one using an optical connector, and the optical waveguides are arranged one by one so as to pass through the surface of each suspension or arm, and guided to a slider at the tip of the suspension or arm. It is what you do.

Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

(1) By constructing an optical delivery system using a laser module, optical connector, and flexible optical waveguide, space saving and cost reduction can be realized by reducing the number of parts.

(2) By making the magnetic head slider part and the light supply part as separate platforms, the slider assembly process is simplified, the yield is improved by the reworkable structure, and the parts are spread by independent development.

FIG. 3 is a schematic diagram showing a configuration of main components of a light delivery mechanism that is housed in the housing of the thermally-assisted hard disk drive according to Embodiment 1 of the present invention. FIG. 6 is a schematic diagram showing a configuration of main parts of a light delivery mechanism that is housed in a housing in a heat-assisted hard disk drive according to Embodiment 2 of the present invention. FIG. 10 is a schematic diagram showing a configuration of main components of a light delivery mechanism that is housed in a housing in a heat-assisted hard disk drive according to Embodiment 3 of the present invention. FIG. 10 is a schematic diagram showing a configuration of an LD module housed in a housing in a heat-assisted hard disk drive according to Embodiment 4 of the present invention. FIG. 10 is a schematic diagram showing a configuration of an LD module housed in a housing in a heat-assisted hard disk drive according to a fifth embodiment of the present invention. In the heat-assisted hard disk drive according to Embodiment 6 of the present invention, it is a perspective view depicting the main components. FIG. 16 is a perspective view illustrating main components of a heat-assisted hard disk drive according to a seventh embodiment of the present invention. It is explanatory drawing of the conversion table which shows an example which converts the head address information by this Embodiment 7 into lead line identification information. FIG. 20 is a perspective view illustrating main components of a heat-assisted hard disk drive according to an eighth embodiment of the present invention.

As described in the above [Problems to be Solved by the Invention], even in a light guide system using an LD module that seems to be less advantageous at first glance, by using the method proposed below, the head As a result, it is considered that a light delivery system (light guide system) that is advantageous as a total system can be realized with a relatively large number of hard disk drives.

In order to introduce a set of light guide systems using LD modules, the arrangement of the LD modules in the hard disk drive and the way of guiding the light from the LD elements to the sliders are key technologies, which are realistic from the viewpoint of cost and space. Is necessary. The present specification proposes a practical method for simultaneously solving the problems of an increase in cost due to an increase in the number of LDs, a shortage of LD module installation space, a complicated mounting, and a deterioration in the yield of integrated components including the head. The method will be specifically described below.

First, as the number of LDs increases, LD elements can be integrated to reduce the number of elements and reduce the size. An LD element can be formed by forming an elongated current confinement region (called a mesa stripe) on a semiconductor substrate having a multilayer structure, but a plurality of current confinement structures can be formed by forming a plurality of current confinement structures on one LD element. LD elements can be integrated. Usually, an element manufactured with the current confinement structure in the same direction and interval is called an LD array element, and is generally used as a light source in optical communication or the printer industry. is there.

Since the LD element can be made into one LD element by arraying, the LD element can be miniaturized and the LD element unit price can be greatly reduced. In addition, only one LD module is required as many as the head, and the mounting space is small.

In some cases, it may be possible to mount as many single LD elements as the number of heads in one LD module. Also in this case, the number of LD modules becomes one, and the mounting space can be reduced.

Also, in order to guide light from the LD module to the slider, an organic or inorganic optical waveguide can be used. Light emitted from the LD module propagates through the optical waveguide and reaches the slider. The optical path from the LD module to the slider is not a straight line, and in order to reach the slider, the optical waveguide is formed on a component such as a suspension connected to the slider.

Since the slider fixed to the gimbal at the tip of the suspension floats on a rotating disk as an information recording medium, the relative position and direction with respect to the suspension must be able to change without receiving a strong external force. In addition, the hard disk arm and suspension move quickly to read and write recorded information on the outer and inner peripheral parts of the disk. Therefore, in the optical waveguide, there is a portion that is not only formed and fixed on a flat substrate-like component but also has to be floated in the air without being supported. To accommodate the above, the optical waveguide must be flexible. Therefore, an organic polymer material that is soft and stretchable and mechanically resistant to bending is more suitable than inorganic materials such as quartz.

The slider and optical waveguide are directly connected with an adhesive after aligning the optical axes. Since the optical waveguide is connected to the slider from the direction of the suspension, the light guiding direction is parallel to the ABS surface of the slider. However, since it is necessary to finally guide light to the ABS surface, it is necessary to bend the optical path direction on the slider and to direct it in a direction perpendicular to the ABS surface. Therefore, it is necessary to install a reflection mirror at 45 degrees with respect to the optical waveguide at the tip of the optical waveguide. However, considering the size of the slider, in order to install the reflecting mirror on the slider, it is necessary to make the mirror ultra-small, and to implement a mounting technique and an optical axis alignment technique corresponding to the ultra-small mirror. This request is not easy. However, by cutting the end of the optical waveguide on the side of the magnetic head slider at an oblique angle of 45 degrees to form a tapered surface, the end of the optical waveguide can have the function of a reflecting mirror, which is relatively easy to form. is there. Therefore, by forming a tapered surface at the end of the optical waveguide, the reflecting mirror can be monolithically integrated into the optical waveguide.

Several methods are conceivable for connecting the LD module and the optical waveguide, but the detachable method is more effective in the assembly process than the method in which the LD module and the optical waveguide are not separable after the LD module and the optical waveguide are connected. desirable. This can be realized by providing an optical connector between the LD module and the optical waveguide. In this case, the optical connector is desirably small in space. The smaller the size, the more flexible the installation location. For example, it can be installed on the arm as a place where the optical connector can be fixed. Further, the optical connector may be directly attached to the LD module to form an LD module with a connector (pluggable LD module).

∙ By attaching the LD module with a connector, it can be handled as a separate part from the head even after assembly. This means that the head and the light source are made into separate platforms, and yield reduction due to excessive hybrid integration can be suppressed by reworking, and the head assembly process can be simplified.

Next, the configuration of the LD module will be described.

LD module has LD array elements mounted inside, and LD array elements have as many channels as the number of heads. Laser light emitted from each channel is guided to a separate optical waveguide connected to each magnetic head slider via a plurality of optical input terminals provided in the optical connector, and from the optical waveguide to a slider at the tip of each head. Led. In general, the smaller the LD array element chip, the smaller the LD array element chip pitch, the higher the number of acquisitions from the viewpoint of semiconductor wafer fabrication, resulting in lower unit costs and cost reduction. Good.

However, in the LD module, each channel of the LD array element is branched to each head by an optical connector. An optical connector is a device that mechanically connects a plurality of optical waveguides with their optical axes coincident with each other, but the size of the optical connector is practically in the order of millimeters even if it is small. Therefore, when a plurality of optical connectors are arranged, the pitch interval between the optical connectors or the optical input terminals is limited to about 1 mm. Therefore, in order to connect the LD array element and the optical connector, a means for expanding the pitch interval of each channel formed in the LD array element in accordance with the pitch interval of the optical input terminal of the optical connector is required. For this reason, in this embodiment, an optical waveguide for pitch adjustment is also provided inside or outside the LD module to eliminate the discrepancy between the channel pitch interval and the adjacent pitch of the optical connector. This optical waveguide for pitch adjustment is preferably provided in the LD module. This is because handling properties such as ease of assembly are improved.

When an optical waveguide for pitch adjustment is provided in the LD module, a microlens array may be disposed between the LD array element and the optical waveguide section in order to improve coupling efficiency between the LD array element and the optical waveguide section. good. The microlens array is an optical element in which a large number of minute lens elements (microlenses) are arranged adjacent to each other. Considering the pitch of the microlens constituting the microlens array, 50 μm to 200 μm is appropriate in practice. Therefore, when a microlens array is used, the pitch between channels of the LD array element is formed to be the same as the pitch interval of the microlens.

In addition, as long as there is a sufficient mounting space, a single LD element can be arranged for the number of heads instead of the LD array element. However, a mounting space is required rather than using an LD array element.

Next, the installation position of the LD module is described.

The head including the slider and suspension moves greatly during the drive operation. The light guide made of the above-mentioned polymer material must be installed at a position where the optical waveguide does not bend even though it can mechanically withstand the movement, because the optical waveguide has an optical bending limit. There is. For this reason, it is desirable that the relative position of the LD module does not change with respect to the head suspension, arm, and rotation axis (pivot), and it is preferable that the LD module be installed so as to move integrally therewith. From the viewpoint of the installation location due to the size and weight of the LD module itself, it is difficult to install it on the suspension or arm, and it is practical to install it on the rotating shaft. Since the upper part of the rotating shaft is not flat and there is no allowance in the thickness direction of the drive, it is desirable to provide a flat part with a substrate or the like on the side of the rotating shaft with a sufficient space and arrange the LD module. The flat portion also serves as a heat sink for the LD module. It is also advantageous that the movement around the rotation axis is relatively small and the vibration to the LD module is relatively small.

In order to drive the LD element, a driver IC is necessary. From the viewpoint of saving installation space, it is desirable that the driver IC is built in the LD module or integrated in the signal processing LSI. Since it is considered that the LD package is required to be considerably reduced in size, it is more realistic to integrate the driver IC in the signal processing LSI than in the LD module.

Next, optical functions desirable for optical waveguides are described.

In the heat-assisted hard disk drive, near-field light may be used as light to irradiate the recording medium. In this case, a near-field light generating element is disposed in the vicinity of the magnetic head slider or the ABS surface of the magnetic head. The near-field light generating element is an element having a size of about several hundred nanometers, and has a function of entering a resonance state and emitting near-field light when coherent light is incident thereon. When the near-field light generating element is used, the light incident on the near-field light generating element needs to have the same polarization direction. Therefore, it is necessary that the optical waveguide serving as the optical path has a polarization maintaining function. Therefore, in the heat-assisted hard disk drive of this embodiment, an LD array element that oscillates in a single mode is used as the LD array element, and an optical waveguide for guiding laser light from the LD module to the near-field light generating element is a single mode. A light guide or a light guide having a mode field close to a single mode is used. By using the single mode light guide, the polarization state of the emitted light can be maintained, and therefore the near-field light generating element can be used. In addition, the light utilization efficiency is increased.

In the case where near-field light is not used as a heat-assisted recording light source, it is possible in principle to use an LD array element that oscillates in multimode. The LD array element that oscillates in multimode has an advantage that the intensity of the generated laser light is higher than the LD array element that oscillates in single mode. However, since the spot size of the generated laser beam is larger than that of an LD array element that oscillates in a single mode, an LD array element that oscillates in a single mode is more suitable for performing high-density recording.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

In the following embodiment, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant, and one is the other. Some or all of the modifications, details, supplementary explanations, and the like are related. Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

(Embodiment 1)
FIG. 1 is a diagram schematically showing the configuration of main components of a light delivery mechanism housed in a housing of the thermally-assisted hard disk drive according to the first embodiment.

In the hard disk drive housing 140, the LD array element 102 is mounted in the LD module 101 (laser module), and the optical waveguide 121 and the optical fiber are connected from the LD module 101 through the optical waveguide 105 and the optical connector 111 of the LD module. Connected mechanically and mechanically. The optical waveguide 121 is formed or fixed on a slider support mechanism such as an arm 143 and a suspension (reference numeral 144 in FIG. 6), and one end opposite to the optical connector 111 is fixed on the slider 142. Connected. One LD module 101 is provided in the hard disk drive housing 140 and branches into a plurality of arms 143 and suspensions (reference numeral 144 in FIG. 6) by the optical connector 111 and the optical waveguide 121. The optical connector 111 may be fixed to the arm 143 or the suspension.

(Embodiment 2)
FIG. 2 is a diagram schematically showing the main parts configuration of the light delivery mechanism housed in the housing of the heat-assisted hard disk drive according to the second embodiment.

In the second embodiment, as compared with FIG. 1, instead of the LD array element 102, a single number of LD elements 103 are mounted in the same number as the number of heads.

(Embodiment 3)
FIG. 3 is a diagram schematically showing the main parts configuration of the light delivery mechanism housed in the housing of the heat-assisted hard disk drive according to the third embodiment.

In the third embodiment, the LD array element 102 is mounted in the LD module 101, and the optical connector 112 is directly provided in the LD module 101, and optically and mechanically with the optical waveguide 121 via the optical connector 111. It is connected to the.

¡By using a compact pluggable module with an optical connector directly on the LD module, the module is easy to handle and easy to assemble with a hard disk drive.

The LD driver IC 148 that drives the LD array element 102 is also installed in the hard disk drive housing 140 and is electrically connected to the LD module 101 by the flexible electric wiring board 152. Further, the LD driver IC 148 can be a multi-function integrated driver IC (reference numeral 149 in FIG. 9) integrated with other ICs such as a signal processing LSI.

(Embodiment 4)
FIG. 4 is a diagram schematically showing an example of the configuration of the LD module housed in the housing of the thermally-assisted hard disk drive according to the fourth embodiment. The LD module 101 and the optical connector 112 shown in FIG. 4 correspond to the LD module 101 and the optical connector 112 of FIG.

In the LD module 101, an LD array element 102 is mounted on a submount 106 made of an insulating material such as ceramics, and a power supply lead pattern 107 made of a conductive material such as gold and a ground lead formed on the submount 106. The pattern 108 is electrically connected to the lead line 109 of the LD module. The lead line 109 is connected to an LD driver (not shown). As shown in FIG. 4 as “LEAD LINE 1 to 4”, each lead line is given an identifier (identification information) for identifying each, and the LD driver is a channel for supplying a laser excitation current. Is identified using the above identification information.

Optically, the pitch is widened by the optical waveguide 105 of the LD module formed on the submount 106 and guided to the optical connector 112 attached to the LD module. The optical connector 112 attached to the LD module is mechanically and optically connected to the optical connector 111 and guides it to the optical waveguide 121 connected to the suspension and the slider ahead.

There are various modes of the optical waveguide 105 of the LD module formed on the submount 106, and it can be formed integrally with the submount 106 using an organic or inorganic material, or can be separately manufactured and fixed by a mounting technique. You can also.

(Embodiment 5)
FIG. 5 is a diagram schematically showing an example of the configuration of the LD module housed in the housing of the thermally-assisted hard disk drive according to the fifth embodiment. The LD module 101 and the optical connector 112 shown in FIG. 5 correspond to the LD module 101 and the optical connector 112 of FIG.

In the LD module 101, a microlens array 115 is inserted to increase the optical coupling efficiency between the LD array element 102 and the optical waveguide 105 of the LD module. The pitch of the LD array element 102 should be as narrow as possible from the viewpoint of the cost of the LD element, and if it is narrower than 200 μm, which is the practical minimum value of the width of the single LD element, the advantage of the array is expected. The microlens array 115 is considered to have a pitch of 50 μm or more that can be manufactured from the accuracy of the lens. Therefore, the pitch of the LD array elements 102 is desirably 50 μm or more and 200 μm or less, and needs to be the same as the pitch of the microlens constituting the microlens array 115.

(Embodiment 6)
FIG. 6 is a perspective view schematically illustrating main components of the heat-assisted hard disk drive according to the sixth embodiment. The LD module 101 and the optical connector 111 illustrated in FIG. 6 correspond to the LD module 101 and the optical connector 111 illustrated in FIGS. 1 and 2.

In the hard disk drive housing 140, there are a recording disk 141 as an information recording medium and a spindle 145 for rotating the recording disk 141. The head portion has an arm 143, a rotation shaft (pivot) 150 serving as a rotation center of the arm 143, an arm. There are a voice coil motor 146 for driving 143, a suspension 144 attached to the arm 143, and a slider 142 at the leading end portion on which the recording element and the reading are formed and levitated above the recording disk 141. An electrical signal for reading and writing magnetic information is processed by a signal processing LSI 147 installed in a casing connected by a flexible electrical wiring board 153.

In the heat-assisted hard disk drive according to the sixth embodiment, the light delivery (light guide) system of the first or second embodiment is added, and the LD module 101 and the LD driver IC 148 for driving the LD element are installed in the housing. The LD module 101 and the LD driver IC 148 are electrically connected by the flexible electric wiring board 152.

The light from the LD module 101 is guided through the optical waveguide 121 connected by the optical connector 111 installed on the arm 143, passes through the suspension 144, and is guided to the slider 142.

The LD module 101 is provided with a flat portion 151 on the side surface of the rotating shaft 150 and is installed and fixed thereon.

(Embodiment 7)
FIG. 7 is a perspective view schematically illustrating main components of the heat-assisted hard disk drive according to the seventh embodiment. FIG. 8 is a diagram for converting head address information according to the seventh embodiment into lead line identification information. It is explanatory drawing of the conversion table which shows an example.

The heat-assisted hard disk drive shown in FIG. 7 includes a plurality of recording disks 141 that are information recording media, a plurality of magnetic head sliders 142 provided on both surfaces of the magnetic disk, and a suspension 144 and an arm that support the magnetic head slider 142. 143, a spindle 145 for rotating a plurality of recording disks, a rotation shaft (pivot) 150 serving as a rotation center of the arm 143, a voice coil motor 146 for driving the arm 143, and a signal processing LSI 147 for processing an electric signal for reading and writing magnetic information. And an LD module 101 that serves as a laser light source, an LD driver 148 that controls the LD module, flexible electric wiring boards 152 and 153 that interconnect these LD module, LD driver, and signal processing LSI. .

On the arm 143 and the suspension 144, there are formed optical waveguides 121 for guiding the laser light generated by the LD module 101 to the plurality of magnetic head sliders one-on-one. The optical waveguide 121 and the LD module 101 are Are connected via an optical connector 112. In the heat-assisted hard disk drive shown in FIG. 7, the LD module 101 and the optical connector 112 shown in FIGS. 3 to 5 are used as the LD module 101 and the optical connector 112.

Although not shown, a hard disk controller that performs overall control of the operation of the entire hard disk is disposed on the back surface of the hard disk housing 140. The hard disk controller includes a CPU that executes various control programs and a memory that stores the control programs. During a recording operation or a reproducing operation, the hard disk controller controls the voice coil motor 146 and the signal processing LSI 147 based on a command from a host device such as a host computer. For example, when recording information at the address specified by the host device, the hard disk controller specifies the physical address on the magnetic disk corresponding to the address specified by the host device and the head address corresponding to the physical address, The signal is transmitted to the signal processing LSI 147 together with user data transmitted from the host device. The signal processing LSI 147 encodes the transmitted user data and transmits the encoded user data to a write amplifier that generates a drive current for the magnetic recording element. At the same time, the signal processing LSI 147 transmits the head address information to the LD driver 148, and the LD driver 148 selects the lead line to which the excitation current of the laser beam is to be supplied based on the transmitted head address information, and the head Laser light is generated from the channel corresponding to the address. For this reason, the LD driver 148 includes a conversion table for converting the head address information into lead line identification information.

FIG. 8 shows one form of the conversion table. The head address field stores head address information, and the lead line identification information field stores lead line identification information corresponding to the head address information. The conversion table is stored in various storage circuits such as a register in the LD driver and SARM. Further, the conversion table shown in FIG. 8 may be included in the signal processing LSI 147. In this case, during the recording operation, the signal processing LSI 147 converts the head address information into lead line identification information and transmits it to the LD driver. The LD driver supplies a channel excitation current to the lead line corresponding to the transmitted lead line identification information. Various circuits are commercially available for the LD driver, and it is more convenient for the signal processing LSI 147 to have the function of converting the head address information into the lead line identification information because an inexpensive commercially available LD driver circuit can be used. .

In the above description, the hard disk controller and the signal processing LSI are formed separately, but both may be formed integrally.

(Embodiment 8)
FIG. 9 is a perspective view schematically illustrating main components of the heat-assisted hard disk drive according to the eighth embodiment. The LD module 101 and the optical connector 111 illustrated in FIG. 9 correspond to the LD module 101 and the optical connector 111 illustrated in FIGS. 1 and 2.

In the eighth embodiment, a multi-function integrated driver IC 149 in which an LD driver IC 148 and a signal processing LSI 147 are integrated is used in the hard disk drive housing 140 as compared with FIG. 6 of the sixth embodiment.

(Effects of Embodiments 1 to 8)
Therefore, the heat-assisted hard disk drives according to the first to eighth embodiments configure an optical delivery (light guide) system using an LD module, an optical connector, and a flexible optical waveguide. Cost reduction can be realized. Further, by making the head part and the light supply part as separate platforms, there are advantages of simplifying the head assembly process, improving the yield by a reworkable structure, and spreading parts by independent development.

As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

The present invention is effective for a high recording density information recording apparatus, particularly a hard disk drive.

Claims (14)

In a heat-assisted hard disk drive including a recording medium, a plurality of magnetic head sliders mounted with a magnetic head that performs a recording operation or a reproducing operation on the recording medium, and a plurality of support mechanisms that support the magnetic head slider ,
The heat-assisted hard disk drive is
A laser module on which a semiconductor laser array element in which a plurality of channels for oscillating laser light are formed on one chip is mounted;
A plurality of optical waveguides for guiding the plurality of laser beams to the magnetic head slider;
An optical connector for connecting the laser module and a plurality of optical waveguides;
A heat-assisted hard disk drive characterized in that laser light emitted from the plurality of channels is guided to the plurality of magnetic head sliders on a one-to-one basis via the plurality of optical waveguides. The heat-assisted hard disk drive according to claim 1,
The plurality of channels and the optical input terminals of the optical connector are arranged at mutually different pitch intervals,
The heat-assisted hard disk, wherein the laser module includes a pitch adjusting optical waveguide for inputting laser light emitted from the plurality of channels to an optical connector in accordance with a pitch interval of the optical input terminals. drive. The heat-assisted hard disk drive according to claim 2,
A heat-assisted hard disk drive characterized in that the pitch of adjacent channels in the semiconductor laser array element is not less than 50 μm and not more than 200 μm. The heat-assisted hard disk drive according to claim 1,
The heat-assisted hard disk drive, wherein the laser module includes a lens array disposed between a mesa stripe for applying a laser excitation current to the semiconductor laser array element and the optical connector. The heat-assisted hard disk drive according to claim 1,
A heat-assisted hard disk drive comprising a near-field light generating element in at least one of the plurality of magnetic head sliders. The heat-assisted hard disk drive according to claim 5,
A heat-assisted hard disk drive characterized in that, of the plurality of optical waveguides, the optical waveguide for guiding the laser beam to a magnetic head slider including the near-field generating element is a single mode optical waveguide. The heat-assisted hard disk drive according to claim 1,
The heat-assisted hard disk drive, wherein the optical connector is provided on a surface of the support mechanism. The heat-assisted hard disk drive according to claim 1,
A heat-assisted hard disk drive, wherein the optical connector is directly provided on the laser module. The heat-assisted hard disk drive according to claim 1,
In the laser module, a single-channel laser element is mounted in one package by the number of the magnetic head sliders instead of the semiconductor laser array element. The heat-assisted hard disk drive according to claim 1,
A heat-assisted hard disk drive, wherein the optical waveguide is an optical waveguide made of an organic polymer. The heat-assisted hard disk drive according to claim 1,
A tapered surface is formed at one end of the optical waveguide on the magnetic head slider side, and a reflecting surface is formed by the tapered surface for allowing the laser light guided through the light guide path to reach the ABS surface of the magnetic head slider. Thermally assisted hard disk drive characterized by The heat-assisted hard disk drive according to claim 1,
A signal processing circuit for switching a magnetic head to be operated using predetermined head address information during the recording operation or the reproducing operation;
An LD driver for driving the semiconductor laser array element;
The laser module includes a plurality of lead lines for supplying a laser oscillation current to the plurality of channels,
The LD driver selects the plurality of lead lines according to head address information transmitted from the signal processing circuit, and supplies a current to the thermally assisted hard disk drive. The heat-assisted hard disk drive according to claim 1,
A signal processing circuit for switching a magnetic head to be operated using predetermined head address information during the recording operation or the reproducing operation;
An LD driver for driving the semiconductor laser array element;
The laser module includes a plurality of lead lines for supplying a laser oscillation current to the plurality of channels,
The signal processing circuit converts the head address information into identification information of the lead line and transmits the identification information to the LD driver, thereby causing the LD driver to drive a predetermined channel. drive. The heat-assisted hard disk drive according to claim 12,
The LD driver includes a data table indicating a correspondence relationship between the head address information and identification information of the plurality of lead lines.

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