JP2008010026A - Light source unit for heat assisted magnetic recording and manufacturing method of thin film magnetic head incorporating the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means in a thin film magnetic head having a structure where the mounting surface and the ABS are vertical, that can prevent the oscillations property of the light source from degrading by the reflected return light by installing the light source apart from the ABS and also prevent the production yield of the whole head from falling by the evaluation of the light source characteristics. <P>SOLUTION: This light source for heat assisted magnetic recording has a unit substrate having an adhering surface on the slider at the side opposite to the ABS, a light source mounted on this unit substrate, a propagating layer provided on the element forming surface vertical to the adhering surface of the unit substrate and including the light path of the light extending from the light source to the end of the adhering surface, and a lens provided on this propagating layer, wherein the end of the adhering surface side of the propagating layer is positioned at a location retreated from the adhering surface. Further, this thin film magnetic head having this light source, and a refractivity adjusting layer at a retreated area of this end is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a light source unit including a light source such as a laser diode, a thin film magnetic head including the light source unit, and a thin film magnetic head, which are constituent elements of a thin film magnetic head that writes signals by a thermally assisted magnetic recording method. The present invention relates to a head gimbal assembly (HGA) and a magnetic disk device including the HGA, and a method of manufacturing a thin film magnetic head including the light source unit.

  As the recording density of magnetic disk devices increases, further improvements in performance of thin film magnetic heads are required. As a thin film magnetic head, a composite thin film magnetic head having a structure in which a magnetoresistive (MR) effect element for reading and an electromagnetic coil element for writing are stacked is widely used. Data signals are read from and written to a magnetic disk.

  Generally, a magnetic recording medium is a discontinuous body in which magnetic fine particles are aggregated, and each magnetic fine particle has a single magnetic domain structure. Here, one recording bit is composed of a plurality of magnetic fine particles. Therefore, in order to increase the recording density, the magnetic fine particles must be made smaller to reduce the irregularities at the boundaries of the recording bits. However, if the magnetic fine particles are made smaller, a decrease in the thermal stability of magnetization accompanying volume reduction becomes a problem.

A measure of the thermal stability of magnetization is given by K _U V / k _B T. Here, K _U is the magnetic anisotropy energy, V the magnetic microparticle volume of one magnetic particle, k _B the Boltzmann constant, T is the absolute temperature. Making the magnetic fine particles smaller means exactly reducing V, and if it is left as it is, K _U V / k _B T becomes smaller and thermal stability is impaired. As a countermeasure to this problem, it is conceivable to increase the K _U simultaneously, increase in K _U results in an increase in the coercive force of the recording medium. On the other hand, the write magnetic field strength by the magnetic head is almost determined by the saturation magnetic flux density of the soft magnetic material constituting the magnetic pole in the head. Therefore, if the coercive force exceeds an allowable value determined from the limit of the write magnetic field strength, writing becomes impossible.

As a first method for solving the problem of the thermal stability of magnetization, a transition from the in-plane magnetic recording method to the perpendicular magnetic recording method can be considered. In the perpendicular magnetic recording medium, the recording layer thickness can be increased, and as a result, V can be increased to improve the thermal stability. As a second method, use of patterned media can be considered. In normal magnetic recording, as described above, one recording bit is composed of N magnetic fine particles and recorded, but using a patterned medium, one recording bit is set as one area of volume NV. As a result, the thermal stability index becomes K _U NV / k _B T, and the thermal stability is dramatically improved.

Further, as a third method for solving the thermal stability problem, while using a large magnetic material K _U, by applying heat to the recording medium immediately before the write magnetic field is applied, the write to reduce the coercive force A so-called heat-assisted magnetic recording system has been proposed. This method is roughly classified into a magnetic dominant recording method and an optical dominant recording method. In the magnetic dominant recording system, the main subject of writing is an electromagnetic coil element, and the radiation diameter of light is larger than the track width (recording width). On the other hand, in the optical dominant recording method, the main subject of writing is the light emitting portion, and the light emission diameter is substantially the same as the track width (recording width). In other words, the magnetic dominant recording system provides spatial resolution to the magnetic field, whereas the optical dominant recording system provides spatial resolution to the light.

  In this thermally assisted magnetic recording system, as a light emitting part for irradiating a recording medium with light, in Patent Document 1, a metal scatterer having a shape such as a cone formed on a substrate, and the scatterer A near-field optical probe including a film made of a dielectric or the like formed around the periphery of the substrate is disclosed. In Patent Document 2, a head using a solid immersion lens in a recording / reproducing apparatus is disclosed. Further, in Patent Document 3, a scatterer constituting a near-field optical probe is formed in contact with the main magnetic pole of a single magnetic pole write head for perpendicular magnetic recording so that the irradiated surface is perpendicular to the recording medium. The configuration is disclosed. Further, Non-Patent Document 1 discloses a U-shaped near-field optical probe formed on a quartz slider. Furthermore, Non-Patent Document 2 discloses a grating in which a diffraction grating that transmits light well is abutted against a diffraction grating that transmits little light.

  As described above, various light emitting portions have been proposed in practice, but what is very important in realizing heat-assisted magnetic recording is that this is provided near the air bearing surface (ABS) of the head. This is means for supplying laser light to the light emitting section.

  For example, the techniques disclosed in Patent Documents 4 and 5 use an optical fiber for supplying laser light. Here, Patent Document 4 discloses a configuration in which a metal film having pinholes is provided on an end face of an optical fiber or the like cut obliquely. Patent Document 5 discloses an optical flying head provided with a movable mirror for appropriately directing laser light emitted from an optical fiber to a lens optical system.

  On the other hand, the techniques disclosed in Patent Document 6 and Patent Document 3 use a semiconductor laser element provided in the head for supplying laser light. Here, Patent Document 6 discloses a configuration in which heat assist is performed by irradiating light from a built-in laser element portion to a minute optical aperture facing a medium. Patent Document 3 discloses a configuration in which a laser element is provided near the ABS or above a head element, and the laser beam is irradiated to a scatterer constituting the above-mentioned near-field light probe.

  Here, an optical fiber as a laser beam supply means is compared with a semiconductor laser element provided in the head. When an optical fiber is used, it is not necessary to form a complicated structure like a semiconductor laser inside the head, and fine near-field light having a desired intensity can be obtained relatively easily. However, when the optical fiber is fixed to the head, it is necessary to bend the optical fiber considerably. In particular, the allowable bending radius is large in a glass fiber, and bending is difficult. In the case of a plastic fiber, the allowable bending radius is reduced to some extent, but the loss is high and the propagation efficiency is lowered.

  In addition, when using an optical fiber, the optical fiber that jumps out of the head may be shaken, adversely affecting the flying characteristics of the slider, or if the head is placed between magnetic disks, there is a risk of contact. There is. In addition, a very large loss occurs at the joint between the optical fiber end and the light source, waveguide layer, or the like. On the other hand, when the semiconductor laser is provided in the head, such a problem does not occur, and the laser beam can be supplied with a relatively low loss without greatly affecting the flying characteristics.

JP 2001-255254 A JP-A-10-162444 JP 2004-158067 A JP 2000-173093 A Japanese translation of PCT publication No. 2002-511176 JP 2001-283404 A Shintaro Miyanishi et al. “Near-field Assisted Magnetic Recording” IEEE TRANSACTIONS ON MAGNETICS, 2005, Vol. 41, No. 10, p. 2817-2821 Koji Shono and Mitsuga Oshiki “Current Status and Issues of Thermally Assisted Magnetic Recording” Journal of Japan Society of Applied Magnetics, 2005, Vol. 29, No. 1, p. 5-13

  However, even when a light source such as a semiconductor laser is used to introduce light, problems such as a decrease in head manufacturing yield and instability of laser oscillation operation due to reflected return light have become problems.

  In general, in a diode chip of a semiconductor laser, it is very difficult to perform nondestructive evaluation of characteristics such as output, laser beam divergence angle, and lifetime. Therefore, when the semiconductor laser is provided in the head, the characteristics are evaluated after the semiconductor laser is installed on the slider or the like, and the quality is determined. As a result, both the yield of the magnetic head portion and the yield of the semiconductor laser portion affect the manufacturing yield of the entire head in an integrated manner, and the yield of the entire head is significantly reduced.

  Considering the problem of installation of the light source on the slider, for example, as disclosed in Patent Document 3, in order to appropriately irradiate light to the scatterer, the light source is extremely applied to the recording medium near the head end surface. When it is installed at a close position, there is a possibility that the light source position is in contact with the recording medium, which is very undesirable from the viewpoint of the reliability of the apparatus.

  On the other hand, for example, according to the technique described in Non-Patent Document 1, light can be incident in a state where a light source such as a semiconductor laser is away from the medium surface. In this case, the light converged from the optical pickup head is directly incident on the near-field optical probe. However, this technique is based on the premise that the integrated surface of the near-field optical probe and the medium facing surface coincide with each other, and the general thin film magnetic field in which the integrated surface and the medium facing surface (ABS) are perpendicular to each other. Unlike the configuration of the head, the affinity is not good. That is, for example, it is very difficult to apply to a thin film magnetic head provided with a vertical conduction type giant magnetoresistive (CPP (Current Perpendicular to Plain) -GMR) effect element or an electromagnetic coil element for perpendicular magnetic recording.

  In addition, when the semiconductor laser is provided in the head in a state of being away from the medium surface, there are usually many interfaces having different refractive indexes in the front and rear on the optical path. Reflected and returned to the semiconductor laser as reflected return light. In addition, reflected return light may be generated for various structural reasons. As a result, the oscillation operation of the semiconductor laser becomes unstable and the oscillation characteristics deteriorate. Such a situation is very likely to occur in a micromachined head, which is a big problem. In order to avoid this problem, it is conceivable to provide an optical isolator, but it is considerably difficult to provide it in a fine head, and the number of man-hours increases.

  Accordingly, an object of the present invention is to prevent a decrease in oscillation characteristics of a light source due to reflected return light in a thin film magnetic head having a structure in which an integration surface and ABS are perpendicular to each other, after the light source is installed at a position away from the ABS. Further, it is an object of the present invention to provide a means capable of avoiding a decrease in manufacturing yield of the entire head due to a light source characteristic evaluation.

  Another object of the present invention is to provide a thin film magnetic head using such means, an HGA equipped with the thin film magnetic head, and a magnetic disk device equipped with the HGA. Another object of the present invention is to provide a method for manufacturing the thin film magnetic head.

  Before describing the present invention, the terms used in the specification are defined. In the laminated structure of the magnetic head elements formed on the integration surface of the substrate, the component on the substrate side of the reference layer is assumed to be “below” or “below” the reference layer, and the reference layer It is assumed that the component on the side in which the layers are stacked is “above” or “above” the reference layer.

  According to the present invention, a unit substrate having an adhesive surface bonded to the surface of the slider opposite to the ABS, a light source provided on the unit substrate, and an element forming surface perpendicular to the adhesive surface of the unit substrate A propagation layer including an optical path of light radiated from the light source and reaching its end face on the adhesive surface side, and provided in this propagation layer, for adjusting the propagation of the light emitted from the light source There is provided a light source unit for thermally assisted magnetic recording in which the end surface on the adhesion surface side of the propagation layer is in a position retracted from the adhesion surface.

  When manufacturing a thin film magnetic head using the light source unit according to the present invention, the refractive index of the propagation layer and the refractive index on the slider side are adjusted to a portion where the end surface on the adhesion surface side of the propagation layer has receded from the adhesion surface. A layer can be provided. This eliminates the air layer between the propagation layer and the slider and allows the light from the light source to propagate in an appropriate environment with no significant difference in refractive index. As a result, the reflection of light can be suppressed to a very low level, and the deterioration of the oscillation characteristics of the light source can be prevented.

  Further, when a thin film magnetic head is manufactured by fixing the light source unit according to the present invention and a slider, for example, if the characteristics of the light source unit are evaluated in advance and only non-defective products are used for manufacturing the thin film magnetic head, the head The yield of the entire head at the time of manufacturing is almost the same as the manufacturing yield of the slider, and a decrease in the manufacturing yield of the entire head due to the characteristic evaluation of the light source unit can be avoided.

  Further, since the light source unit according to the present invention is bonded to the surface of the slider opposite to the ABS, it is possible to always install the light source at a position away from the ABS. Further, by using such a light source unit, it is possible to make the light having an appropriate traveling direction and adjusted in propagation incident on the slider. That is, in a thin film magnetic head having a structure in which the integration surface and the ABS are perpendicular, light having an appropriate size and direction can be reliably supplied. As a result, heat-assisted magnetic recording with high heating efficiency of the magnetic recording medium can be realized.

  Further, in the light source unit according to the present invention, a layer surface that is the layer surface of the propagation layer and is formed obliquely with respect to the element formation surface is used as an optical path changing unit for directing light to the end surface on the adhesion surface side of the propagation layer. It is preferable to further include a prism portion as a reflecting surface. Furthermore, it is preferable that the lens unit is a diffractive optical element unit. Furthermore, the light source is a laser diode, and this laser diode is formed on the surface opposite to the bonding surface of the unit substrate and is provided in a trench extending to the element formation surface. The light emitting end is exposed without being blocked by the unit substrate, and the unit substrate has conductivity, and the electrode forming the bottom surface of the laser diode is electrically connected to the unit substrate. preferable.

  According to the present invention, there is further provided a unit processing bar in which the individual chips after separation become the light source unit described above by being cut and separated.

  According to the present invention, furthermore, the ABS and the slider substrate having the integrated surface perpendicular to the ABS, the magnetic head element formed on the integrated surface, and the light from the end surface on the side opposite to the ABS receive the ABS side. The slider includes a waveguide layer for propagating toward the slider end surface, a magnetic head element and a coating layer formed on the integrated surface so as to cover the waveguide layer, and the slider ABS is opposite The adhesive surface is in contact with the side surface, and the light emitted from the end surface on the adhesive surface side of the propagation layer is fixed in position so that the light propagates through the waveguide layer and reaches the slider end surface on the ABS side. The light source unit described above, and at least between the end surface of the propagation layer that emits light and the end surface on the side opposite to the ABS of the waveguide layer that receives light, A refractive index adjustment layer is provided. Thin film magnetic head have is provided.

  Usually, when a thin film magnetic head is manufactured by fixing a light source unit and a slider, the facing portions of the two do not completely adhere to each other, and an air layer is inevitably formed between them. When this air layer is present on the optical path, a large amount of light is reflected and returned to the light source as reflected return light. As a result, the oscillation operation of the light source is destabilized. On the other hand, according to the thin film magnetic head of the present invention, the provision of the refractive index adjustment layer eliminates such an air layer and provides an appropriate environment in which light does not have a large difference in refractive index. Will propagate. Therefore, reflection between the propagation layer and the waveguide layer can be kept very small. As a result, it is possible to prevent a decrease in the oscillation characteristics of the light source.

  In the thin film magnetic head according to the present invention, the refractive index adjusting layer is formed of a UV curable resin, and the refractive index of the UV curable resin is a value between the refractive index value of the propagation layer and the refractive index value of the waveguide layer. It is preferable that Furthermore, it is more preferable that the propagation layer is silicon dioxide or alumina, the waveguide layer is tantalum oxide, niobium oxide or titanium oxide, and the refractive index adjustment layer is polymethylphenylsilane.

  In the thin film magnetic head according to the present invention, the slider is provided at a position in contact with the ABS end face of the waveguide layer or at a position close to the end face, and a near field light is generated to write a data signal. In this case, it is preferable to further include a near-field light generating section having an end reaching the slider end surface on the ABS side for heating the magnetic recording medium.

  Further, according to the present invention, the thin film magnetic head described above, a support mechanism for supporting the thin film magnetic head, a signal line for the magnetic head element, and a power supply line for the light source are provided. An HGA is provided. Furthermore, at least one HGA is provided, and at least one magnetic recording medium, and writing and reading operations performed by the thin film magnetic head on the at least one magnetic recording medium are controlled, and the light emission operation of the light source is performed. There is provided a magnetic disk device further comprising a recording / reproducing and light emission control circuit for controlling.

According to the present invention, a unit substrate having an adhesive surface, a light source provided on the unit substrate, and an adhesive surface of the unit substrate are provided on a vertical element formation surface, and are emitted from the light source and bonded. Forming a light source unit comprising a propagation layer including an optical path of light reaching the end face of the surface side, and a lens part;
After the light source unit is formed or before the light source unit is cut and separated from the unit processing bar, the adhesive layer side or the end surface of the bar adhesive surface side of the propagation layer or the layer serving as the propagation layer is retracted from the adhesive surface or the bar adhesive surface. Let
A slider substrate having an ABS and an integrated surface perpendicular to the ABS, a magnetic head element formed on the integrated surface, and light received from its own end surface opposite to the ABS and propagated toward the slider end surface on the ABS side A slider having a waveguide layer and a coating layer formed on the integrated surface so as to cover the magnetic head element and the waveguide layer;
Adhesive resin is applied to the surface of the light source unit on the bonding surface side and / or the surface of the slider opposite to the ABS, and the surface on the bonding surface and the surface opposite to the ABS are in contact with each other. The adhesive resin is filled between at least the end surface of the propagation layer on the adhesive surface side and the end surface of the waveguide layer opposite to the ABS, and the radiation is emitted from the end surface of the propagation layer on the adhesive surface side. A method of manufacturing a thin film magnetic head is provided in which the light is propagated through the waveguide layer and aligned so as to reach the slider end surface on the ABS side, and the light source unit and the slider are fixed.

  By forming the above-described refractive index adjustment layer using such a manufacturing method, the air layer is excluded between the propagation layer and the waveguide layer, and the refractive index of the light from the light source is reduced. Proper environment with no big difference can be propagated. Therefore, reflection between the propagation layer and the waveguide layer can be kept very small. As a result, it is possible to prevent a decrease in the oscillation characteristics of the light source. That is, according to the method of manufacturing a thin film magnetic head according to the present invention, the integration surface and the ABS are perpendicular to each other, and the light source oscillation characteristics of the reflected light by the reflected return light after the light source is installed at a position away from the ABS. A thin film magnetic head capable of preventing the decrease can be manufactured.

  Furthermore, for example, if the characteristics of the light source unit are evaluated in advance and only non-defective products are used for manufacturing the thin film magnetic head, the yield of the entire head at the time of manufacturing the head becomes almost the manufacturing yield of the slider. A decrease in manufacturing yield of the entire head can be avoided.

  In this manufacturing method according to the present invention, a material having a polishing rate larger than that of the constituent material of the unit substrate is selected as the constituent material of the propagation layer, and then the surface of the light source unit on the bonding surface side is polished, thereby It is preferable to retract the end surface on the adhesive surface side from the adhesive surface. In addition, as the adhesive resin, a UV curable resin having a refractive index between the refractive index value of the propagation layer and the refractive index value of the waveguide layer is selected, and then the adhesive resin is applied. After that, it is also preferable that the contact surface between the light source unit and the slider is fixed by being irradiated with ultraviolet rays.

Further, according to the present invention, the individual chips after separation are formed on the unit substrate having the adhesion surface, the light source that emits light, and the element formation surface perpendicular to the adhesion surface by being cut and separated. A light source unit for heat-assisted magnetic recording comprising a propagation layer for propagating light and a lens part, forming a unit processing bar having a bar adhesion surface that becomes an adhesion surface by being cut and separated,
After forming the unit processing bar or before providing a light source to the unit processing bar, the end surface on the bar bonding surface side of the layer that becomes a propagation layer by being cut and separated is retreated from the bar bonding surface,
By being cut and separated, the individual chips after separation are separated from each other by the ABS and the slider substrate having the integrated surface perpendicular to the ABS, the magnetic head element formed on the integrated surface, and the light on its own side opposite to the ABS. Forming a slider processing bar serving as a slider comprising a waveguide layer for receiving from the end face and propagating toward the slider end face on the ABS side, and a covering layer covering the magnetic head element and the waveguide layer;
Apply the adhesive resin to the bar bonding surface side of the unit processing bar and / or the surface opposite to the ABS surface of the slider processing bar, and this bar bonding surface side The adhesive resin is provided between the end surface on the side of the bar bonding surface of the layer serving as the propagation layer and the end surface on the side opposite to the ABS of the waveguide layer, with the surface opposite to the surface serving as the ABS being in contact. The unit processing bar and slider processing are performed after positioning so that the light emitted from the end surface on the adhesion surface side of the propagation layer propagates through the waveguide layer and reaches the slider end surface on the ABS side. A method of manufacturing a thin film magnetic head is provided in which the bar is fixed and then the unit processing bar and the slider processing bar which are fixed are cut and separated.

  Here, as the constituent material of the layer to be the propagation layer, a material having a polishing rate larger than that of the constituent material of the unit substrate is selected, and then the surface on the bar bonding surface side of the unit processing bar is polished, It is preferable that the end surface on the bar bonding surface side of the layer to be formed is retracted from the bar bonding surface. In addition, as the adhesive resin, a UV curable resin having a refractive index between the refractive index value of the layer serving as the propagation layer and the refractive index value of the waveguide layer is selected. After applying the resin, it is also preferable that the contact surface between the unit processing bar and the slider processing bar is fixed by irradiation with ultraviolet rays.

  According to the light source unit for thermally assisted magnetic recording according to the present invention, the thin film magnetic head using the light source unit, the HGA including the thin film magnetic head, and the magnetic disk device including the HGA, the integration surface and the ABS are perpendicular to each other. In this head configuration, the light source can be installed at a position away from the ABS, and the oscillation characteristics of the light source can be prevented from being deteriorated by the reflected return light. Further, the production yield of the entire head can be avoided by evaluating the characteristics of the light source. can do.

  Further, according to the method of manufacturing a thin film magnetic head according to the present invention, the integration surface and the ABS are vertical, and the light source oscillation characteristics of the light source due to the reflected return light after the light source is installed at a position away from the ABS. It is possible to manufacture a thin film magnetic head capable of preventing a decrease, and further, it is possible to avoid a decrease in manufacturing yield due to a light source characteristic evaluation.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated in detail, referring an accompanying drawing. In the drawings, the same elements are denoted by the same reference numerals. In addition, the dimensional ratios in the components in the drawings and between the components are arbitrary for easy viewing of the drawings.

  FIG. 1 is a perspective view schematically showing a configuration of a main part in an embodiment of a magnetic disk device and an HGA according to the present invention. Here, in the perspective view of the HGA, the side facing the surface of the magnetic disk of the HGA is displayed facing up.

  In the figure, 10 is a magnetic disk which is a plurality of magnetic recording media rotating around the rotation axis of the spindle motor 11, 12 is an assembly carriage device for positioning the thin film magnetic head 21 on the track, and 13 is A recording / reproducing and light emission control circuit for controlling writing and reading operations of the thin-film magnetic head 21 and for controlling a laser diode as a light source for generating laser light for heat-assisted magnetic recording, which will be described in detail later, are shown. Yes.

  The assembly carriage device 12 is provided with a plurality of drive arms 14. These drive arms 14 can be angularly swung about a pivot bearing shaft 16 by a voice coil motor (VCM) 15 and are stacked in a direction along the shaft 16. An HGA 17 is attached to the tip of each drive arm 14. Each HGA 17 is provided with a thin film magnetic head 21 so as to face the surface of each magnetic disk 10. The magnetic disk 10, the drive arm 14, the HGA 17, and the thin film magnetic head 21 may be singular.

  The HGA 17 is configured by fixing a thin film magnetic head 21 to the tip of the suspension 20 and further electrically connecting one end of a wiring member 203 to a terminal electrode of the thin film magnetic head 21. The suspension 20 includes a load beam 200, an elastic flexure 201 fixed and supported on the load beam 200, a base plate 202 provided at the base of the load beam 200, and a lead conductor provided on the flexure 201. And a wiring member 203 composed of connection pads electrically connected to both ends thereof.

  It is obvious that the suspension structure in the HGA 17 of the present invention is not limited to the structure described above. Although not shown, a head driving IC chip may be mounted in the middle of the suspension 20.

  FIG. 2 is a perspective view showing an embodiment of a light source unit according to the present invention and a thin film magnetic head provided with the light source unit.

  According to FIG. 2, the thin film magnetic head 21 includes a slider 22 having a magnetic head element 32 for writing and reading data signals, and a light source unit 23 having a laser diode 40 serving as a light source for thermally assisted magnetic recording. However, it has a configuration in which the respective back surface 2201 and the bonding surface 2300 are brought into contact with each other and bonded and fixed. Here, the back surface 2201 of the slider 22 is the surface of the slider 22 opposite to the ABS 2200.

  The slider 22 reads a data signal provided on a slider substrate 220 having an ABS 2200 which is a medium facing surface processed so as to obtain an appropriate flying height, and an integration surface 2202 perpendicular to the ABS 2200 of the slider substrate 220. A magnetic head element 32 composed of an MR effect element 33 and an electromagnetic coil element 34 for writing a data signal, a waveguide layer 35 provided between the MR effect element 33 and the electromagnetic coil element 34, and a magnetic disk An integrated surface 2202 so as to cover the near-field light generator 36 for generating near-field light for heating the recording layer portion, and the MR effect element 33, the electromagnetic coil element 34, the waveguide layer 35, and the near-field light generator 36. 2 on the MR effect element 33 and the electromagnetic coil element 34 exposed from the layer surface of the cover layer 38 provided on the cover layer 38. Each and a total of four signal electrodes 37 are connected.

  One end of the MR effect element 33, the electromagnetic coil element 34, and the near-field light generating unit 36 reaches the slider end surface 221 on the ABS 2200 side. During the actual writing or reading operation, the thin film magnetic head 21 floats hydrodynamically on the surface of the rotating magnetic disk with a predetermined flying height. At this time, the MR effect element 33 and the end of the electromagnetic coil element 34 are opposed to the magnetic disk through a minute spacing, whereby reading by sensing the data signal magnetic field and writing by applying the data signal magnetic field are performed.

  Here, when the data signal is written, the laser light propagating from the light source unit 23 through the waveguide layer 35 irradiates the near-field light generating unit 36, and by this irradiation, the slider end surface of the near-field light generating unit 36. Near-field light is generated from the end reaching 221. With this near-field light, heat-assisted magnetic recording can be performed as described later.

  The waveguide layer 35 has two side surfaces 351 that are curved along a parabola and that are opposite to each other in the track width direction, and are aligned in parallel to the incident surface 352 that reaches the slider end surface 222 opposite to the ABS 2200. The reflected laser light 39 can be condensed on the condensing surface 350 which is the end surface on the slider end surface 221 side by reflection on the both side surfaces 351. Here, the slider end surface 221 is a surface on the ABS 2200 side of the slider 22 and is a surface other than the ABS 2200, and the slider end surface 222 is a surface opposite to the ABS 2200 of the slider 22 and a portion other than the back surface 2201. This is the aspect. Further, the near-field light generating part 36 is in contact with a fine near-field light gap part 361 whose one end is in contact with the condensing surface 350 of the waveguide layer 35 and whose other end reaches the slider end face 221. Are provided with two opposing metal layers 360 that face each other through the near-field light gap portion 361. In the near-field light generating part 36, the near-field light gap part 361 and the opposing metal layer 360 sandwiching the fine near-field light gap part 361 realize a so-called “bow tie type” structure. In this “bow tie type” structure, near-field light is generated due to the concentration of a very strong electric field generated at the center thereof.

  The electric field strength of this near-field light is orders of magnitude stronger than that of incident light, and this very strong near-field light rapidly heats the opposing local portion of the magnetic disk surface. As a result, the coercive force of this local portion is reduced to a size that allows writing by a write magnetic field, so that even if a high coercivity magnetic disk for high-density recording is used, writing by the electromagnetic coil element 34 is possible. Become. The near-field light is present in a region from the slider end surface 221 toward the surface of the magnetic disk up to the width or the layer thickness of the near-field light gap portion 361 described above in the track width direction. Accordingly, in the present situation where the flying height is 10 nm or less, the near-field light can sufficiently reach the recording layer portion. Further, the width of the near-field light generated in this way is approximately the same as the above-described width or layer thickness, and the electric field intensity of the near-field light is exponentially in a region greater than this width or layer thickness. Since it attenuates, the recording layer portion of the magnetic disk can be heated very locally.

  Similarly, according to FIG. 2, the light source unit 23 is formed on a unit substrate 230 having an adhesive surface 2300 bonded to the back surface 2201 of the slider 22 and a unit upper surface 2301 opposite to the adhesive surface 2300 of the unit substrate 230. The laser diode 40 is located in the trench 2003 extending to the element formation surface 2302 perpendicular to the adhesive surface 2300 and is exposed to the light emitting end 400 without being blocked by the unit substrate 230. And a propagation layer 41 that is provided on the element formation surface 2302 and includes an optical path of the laser light emitted from the laser diode 40, and propagates the laser light to the end surface 410 on the bonding surface side thereof. A lens portion provided in the propagation layer 41 for adjusting the propagation of the laser light emitted from the laser diode 40; The diffractive optical element unit 42 and the propagation layer 41 are provided on the propagation layer 41 and formed obliquely with respect to the element formation surface 2302. The layer surface of the propagation layer 41 is a reflection surface 430, and laser light is directed to the end surface 410. For this purpose, a prism portion 43 as an optical path changing portion and drive terminal electrodes 440 and 441 for the laser diode 40 are provided.

  Note that the end surface 410 is parallel to the bonding surface 2300 but is not aligned on one plane, and is provided at a position retracted (recessed) from the bonding surface 2300 in the direction of going back the optical path. As will be described in detail later, the receding space is filled with the refractive index adjustment layer, so that, for example, the end surface 410 does not have to be parallel to the bonding surface 2300. However, the end face 410 is preferably optically smooth in order to minimize the scattering loss of the laser light.

The laser light emitted from the light emitting end 400 of the laser diode 40 spreads around the axis a _L perpendicular to the element formation surface 2302 as it propagates through the propagation layer 41. a By passing through the diffractive optical element section 42 having _L as its own axis, the light is converted into parallel light or focused light. The laser light adjusted in this way reaches the reflection surface 430 of the prism portion 43 and is totally reflected on the same surface, thereby changing its traveling direction to 90 °, that is, a direction perpendicular to the bonding surface 2300 (ABS 2200). It is done. Thereafter, the laser light propagates to the end surface 410 on the adhesion surface 2300 side of the propagation layer 41 and is emitted from the end surface 410.

  The laser light emitted from the end face 410 enters the end face 352 of the waveguide layer 35 through the refractive index adjustment layer 45 as laser light propagating in a direction parallel to the layer surface of the waveguide layer 35. Here, the refractive index adjustment layer 45 is at least between the end face 410 and the end face 352 of the waveguide layer 35, and preferably the face opposite to the end face 410 and the ABS 2200 of the slider 22 (slider end face 222 and back face 2201). It is formed so as to be filled in between. Further, the refractive index of the refractive index adjusting layer 45 is set to a value between the refractive index value of the propagation layer 41 and the refractive index value of the waveguide layer 35.

  Usually, when the slider 22 and the light source unit 23 are fixed, the surface of the slider 22 opposite to the ABS 2200 and the end surface 410 of the propagation layer 41 of the light source unit 23 are not completely in close contact with each other. An air layer is inevitably formed. If this air layer is present on the optical path of the laser light, the difference in refractive index is large at the interface between the end face 410 and the air layer, so that a lot of laser light is reflected. The reflected laser light returns to the laser diode 40 as reflected return light, which destabilizes the oscillation operation of the laser diode 40.

  On the other hand, the refractive index adjustment layer 45 whose refractive index is adjusted to a value between the refractive index value of the propagation layer 41 and the refractive index value of the waveguide layer 35 is provided in a filled manner. The laser light propagates through an appropriate environment without a large difference in refractive index after eliminating a layer of air. Therefore, the reflection between the propagation layer 41 and the waveguide layer 35 can be suppressed to be very small. As a result, deterioration of the oscillation characteristics of the laser diode 40 can be prevented.

  Further, as described above, the thin film magnetic head 21 has a configuration in which the slider 22 and the light source unit 23 are combined, and can be manufactured by combining them after forming each. Therefore, for example, if the characteristics of the light source unit are evaluated in advance and only non-defective products are used in the manufacture of thin film magnetic heads, the manufacturing yield of the entire head at the time of manufacturing the head becomes almost the manufacturing yield of the slider, and the laser diode as the light source It is possible to avoid a decrease in manufacturing yield of the entire head due to the characteristic evaluation.

  Further, since the light source unit 23 is bonded to the surface of the slider 22 opposite to the ABS 2200, the laser diode 40 can always be installed at a position away from the ABS 2200.

  Further, by using such a light source unit 23, as described above, the laser beam propagating in the direction parallel to the layer surface of the same layer can be made incident on the end surface 352 of the waveguide layer 35 of the slider 22. That is, in the thin film magnetic head 21 having a configuration in which the integration surface 2202 and the ABS 2200 are perpendicular, laser light having an appropriate size and direction can be reliably supplied. As a result, heat-assisted magnetic recording with high heating efficiency of the recording layer of the magnetic disk can be realized.

  The sizes of the slider 22 and the light source unit 23 are arbitrary. For example, the slider 22 may be a so-called femto slider having a width in the track width direction of 700 μm × length (depth) 850 μm × thickness 230 μm. In this case, the light source unit 23 may be one size smaller than this, for example, 700 μm width in the track width direction × 700 μm length (depth) × 180 μm thickness. The width of the light source unit 23 in the track width direction is preferably the same as the width of the slider 22 in the track width direction so that it can be easily confirmed when alignment is performed. It can be smaller.

  Further, a typical size of a laser diode that is usually used is, for example, about 250 μm wide × 250 μm long (depth) × 65 μm thick. For example, the upper surface 2301 of the light source unit 23 having the above-described size It is sufficiently possible to form a trench 2003 in which a laser diode 40 of a size can be installed. At this time, if the depth of the trench 2003 is 65 μm or several μm deeper than this, the upper surface of the laser diode 40 can be made equal to or lower than the unit upper surface 2301. However, the depth of the dug 2003 may be about 30 μm, for example, and the upper surface of the laser diode 40 may be slightly protruded. Further, by reducing the size of the light source unit 23 within a range in which the laser diode 40 can be installed, a larger number of light source units 23 can be obtained from one substrate wafer.

  Further, in the spot of the laser beam reaching the end surface 410 of the propagation layer 41, the diameter in the track width direction can be set to about 5 to 40 μm, for example, and the diameter orthogonal to the diameter can be set to about 1 to 6 μm, for example. On the other hand, the thickness of the waveguide layer 35 that receives this laser light can be set to about 1 to 6 μm, for example, and the width in the track width direction at the end face 352 of the waveguide layer 35 can be set to about 50 to 500 μm, for example. When the size is set as described above, the light emitted from the end surface 410 of the propagation layer 41 propagates through the waveguide layer 35 and reaches the slider end surface 221 (near-field light generating unit 36) on the ABS 2200 side. When aligning the positions of the slider 22 and the light source unit 23, the positioning in the track width direction can be performed relatively easily as compared with the positioning in the direction perpendicular to the track width direction.

  As a change mode, the condensing surface 350 of the waveguide layer 35 is exposed from the slider end surface 221 without providing the near-field light generating unit 36 in the slider 22 and irradiated with the laser beam condensed on the magnetic disk. The magnetic disk may be heated.

  3A is a cross-sectional view taken along the line AA of FIG. 2, schematically showing the configuration of the main part of the thin-film magnetic head 21 shown in FIG. 2, and FIG. 4 is a plan view showing the shape of the end of the slider end surface 221 of the near-field light generating unit 36. FIG.

  First, components of the slider 22 of the thin film magnetic head 21 will be described.

In the slider 22 of FIG. 3A, reference numeral 220 denotes a slider substrate made of AlTiC (Al ₂ O ₃ —TiC) or the like, and has an ABS 2200 facing the surface of the magnetic disk. An MR effect element 33 for reading, an electromagnetic coil element 34 for writing, and a coating layer 38 for protecting these elements are formed on the integrated surface 2202 which is one side surface of the slider substrate 220 with the ABS 2200 as the bottom surface. Is mainly formed.

  The MR effect element 33 includes an MR multilayer 332, and a lower shield layer 330 and an upper shield layer 334 disposed at positions sandwiching the multilayer. The lower shield layer 330 and the upper shield layer 334 may be made of, for example, NiFe, CoFeNi, CoFe, FeN, or FeZrN having a thickness of about 0.5 to 3 μm formed by a pattern plating method including a frame plating method. it can.

  The MR multilayer 332 is composed of a current in plain (CIP) giant magnetoresistive (GMR) multilayer film, a vertical current type (CPP (Current Perpendicular to Plain)) GMR multilayer film, or a tunnel. It includes a magnetoresistive (TMR (Tunnel Magneto Resistive)) multilayer film and senses a signal magnetic field from a magnetic disk with very high sensitivity. The upper and lower shield layers 334 and 330 prevent the MR multilayer 332 from being affected by an external magnetic field that causes noise.

  When the MR multilayer 332 includes a CIP-GMR multilayer film, insulating upper and lower shield gap layers are provided between the upper and lower shield layers 334 and 330 and the MR multilayer 332, respectively. Further, an MR lead conductor layer for supplying a sense current to the MR multilayer 332 and taking out a reproduction output is formed. On the other hand, when the MR multilayer 332 includes a CPP-GMR multilayer film or a TMR multilayer film, the upper and lower shield layers 334 and 330 also function as upper and lower electrode layers, respectively.

  When the MR multilayer 332 includes, for example, a TMR effect multilayer film, the antiferromagnetic layer having a thickness of about 5 to 15 nm made of IrMn, PtMn, NiMn, RuRhMn, and the like, and CoFe that is a ferromagnetic material, for example, or Ru A magnetization pinned layer composed of two layers of CoFe or the like with a nonmagnetic metal layer or the like sandwiched therebetween and the magnetization direction of which is pinned by an antiferromagnetic layer, and a thickness of 0.5 to 1 nm made of, for example, Al or AlCu A tunnel barrier layer made of a non-magnetic dielectric material in which a metal film of a degree is oxidized by oxygen introduced into the vacuum apparatus or by natural oxidation, and a CoFe having a thickness of about 1 nm, for example, a ferromagnetic material, A magnetization free layer that is composed of a two-layer film of about 4 nm of NiFe or the like and that forms a tunnel exchange coupling with the magnetization fixed layer via the tunnel barrier layer is sequentially laminated. Have a structure.

  The electromagnetic coil element 34 is for perpendicular magnetic recording, and includes a main magnetic pole layer 340, a gap layer 341, a coil layer 342, a coil insulating layer 343, and an auxiliary magnetic pole layer 344. The main magnetic pole layer 340 is a magnetic path for guiding the magnetic flux induced by the coil layer 342 while converging it to the recording layer of the magnetic disk on which writing is performed. Here, the length (thickness) in the layer thickness direction of the end portion 340a on the slider end surface 221 side of the main magnetic pole layer 340 is smaller than the other portions. As a result, it is possible to generate a fine write magnetic field corresponding to an increase in recording density.

Here, the main magnetic pole layer 340 has, for example, a total thickness of about 0.01 μm to about 0.5 μm at the end on the ABS side, and a total thickness of other than this end is about 0.5 μm to about 3 μm. 0.0 μm, for example, an alloy composed of any two or three of Ni, Fe and Co formed by using a frame plating method, a sputtering method or the like, or an alloy to which a predetermined element is added based on these alloys Etc. The gap layer 341 is made of, for example, Al ₂ O ₃ or DLC having a thickness of about 0.01 μm to about 0.5 μm formed by using, for example, a sputtering method or a CVD method. The coil layer 342 is made of, for example, Cu or the like having a thickness of about 0.5 μm to about 3 μm and formed using, for example, a frame plating method. The coil insulating layer 343 is composed of, for example, a heat-cured resist layer having a thickness of about 0.1 μm to about 5 μm. The auxiliary magnetic pole layer 344 is, for example, an alloy having a thickness of about 0.5 μm to about 5 μm and formed of any two or three of Ni, Fe, and Co, for example, using a frame plating method, a sputtering method, or the like. Or an alloy containing these as a main component and a predetermined element added thereto.

The waveguide layer 35 is located between the MR effect element 33 and the electromagnetic coil element 34 and extends in parallel with the integration surface 2202. However, the thickness of the waveguide layer 35 toward the slider end surface 221 is near the slider end surface 221. It also has a tapered shape in the vertical direction. The waveguide layer 35 is formed by patterning a dielectric material having a higher refractive index n than that of the material forming the covering layer 38, for example, using a sputtering method or the like, using a photolithography method, an ion milling method, or the like. Is formed by. For example, when the coating layer 38 is made of silicon dioxide SiO ₂ (n = 1.5), the waveguide layer 35 may be made of alumina Al ₂ O ₃ (n = 1.63). . Furthermore, when the coating layer 38 is made of alumina Al ₂ O ₃ (n = 1.63), the waveguide layer 35 is made of tantalum oxide Ta ₂ O ₅ (n = 2.16), niobium oxide Nb _2. It may be formed of O ₅ (n = 2.33), titanium oxide TiO (n = 2.3 to 2.55) or titanium oxide TiO ₂ (n = 2.3 to 2.55). By configuring the waveguide layer 35 with such a material, not only the good optical properties of the material itself but also the total reflection conditions at the interface are adjusted, so that the propagation loss of the laser light is reduced and the near field is reduced. Light generation efficiency is improved.

  In FIG. 3A, the near-field light gap part 361 of the near-field light generating part 36 is formed of the same dielectric material as that of the waveguide layer 35. Further, the counter metal layer 360 of the near-field light generator 36, which is not shown in FIG. 3A and shown in FIG. 2, is made of Au, Pd, Pt, Rh, Ir, or any of these. It is made of a conductive material such as an alloy composed of several combinations or an alloy containing Al, Cu or the like.

  The width and layer thickness of the near-field light gap 361 in the track width direction are sufficiently smaller than the wavelength of the incident laser light, and are about 10 nm to about 300 nm and about 10 nm to about 200 nm, respectively. The length of the near-field light gap 361 in the direction perpendicular to the slider end surface 221 is, for example, about 10 to 500 nm. The width in the track width direction at the end face 352 of the waveguide layer 35 is, for example, about 50 to 500 μm.

  3B, on the slider end surface 221, the generation end 361a of the near-field light gap 361 is close to the end 340b of the main magnetic pole layer 340 of the electromagnetic coil element 34, and the leading side of the end 340b. Is located. The shape of the generating end 361a is a regular trapezoid having a short side on the trailing side.

  Here, the near-field light generally has the strongest intensity in the vicinity of the short side on the trailing side having the narrowest width, although it depends on the wavelength of the incident laser light and the shape of the waveguide layer 35. That is, in the heat assist operation for heating the recording layer portion of the magnetic disk, the vicinity of the short side on the trailing side is the main heating operation portion.

  The shape of the end 340b of the main magnetic pole layer 340 is an inverted trapezoid having a long side on the trailing side. That is, the side surface of the end portion 340a of the main magnetic pole layer 340 is provided with a bevel angle so that unnecessary writing or the like is not exerted on the adjacent track due to the influence of the skew angle generated by driving with the rotary actuator. The size of the bevel angle is, for example, about 15 °. Actually, the write magnetic field is mainly generated in the vicinity of the long side on the trailing side, and the width of the write track is determined by the length of the long side.

  According to the arrangement and shape of the generation end 361a of the near-field light gap 361 and the end 340b of the main magnetic pole layer 340 described above, the vicinity of the short side on the trailing side of the generation end 361a which is the main heating action portion However, since it is at a position very close to the end 340b of the main magnetic pole layer, which is the writing portion, immediately after the heat is applied to the recording layer portion of the magnetic disk, the writing magnetic field can be applied with almost no gap. As a result, a stable writing operation by heat assist can be surely executed.

  As a modification, the electromagnetic coil element 34 may be for longitudinal magnetic recording. In this case, instead of the main magnetic pole layer 340 and the auxiliary magnetic pole layer 344, a lower magnetic pole layer and an upper magnetic pole layer are provided, and a write gap sandwiched between ends of the lower magnetic pole layer and the upper magnetic pole layer on the slider end surface 221 side. A layer is provided. Writing is performed by a leakage magnetic field from the position of the write gap layer.

  An inter-element shield layer 48 is formed between the MR effect element 33, the waveguide layer 35, and the near-field light generator 36. The inter-element shield layer 48 and the waveguide layer 35 are interposed between the MR effect element 33 and the waveguide layer 35. Further, a backing coil portion may be formed. The backing coil section generates a magnetic flux that is generated from the electromagnetic coil element 34 and cancels the magnetic flux loop passing through the upper and lower electrode layers of the MR effect element 33, and is a wide adjacent track that is an unnecessary write or erase operation on the magnetic disk. This is intended to suppress the erasing (WAIT) phenomenon. This backing coil portion is omitted in the case of a head for longitudinal magnetic recording, or even if it is a head for perpendicular magnetic recording. The coil layer 342 is one layer in FIG. 3A, but may be two or more layers or a helical coil.

  Next, components of the light source unit 23 of the thin film magnetic head 21 will be described.

In the light source unit 23 of FIG. 3A, reference numeral 230 denotes a unit substrate made of AlTiC (Al ₂ O ₃ —TiC) or the like, and has a bonding surface 2300 bonded to the back surface 2201 of the slider substrate 220. . A propagation layer 41 is provided on an element formation surface 2302 that is one side surface when the adhesive surface 2300 is used as a bottom surface. The propagation layer 41 is provided with a diffractive optical element portion 42 and a prism portion 43. In addition, a laser diode 40 is installed in a trench 2003 formed in the unit substrate 230.

The propagation layer 41 includes an optical path from the light output end 400 of the laser diode 40 to the end face 410 of the laser diode 40 via the diffractive optical element portion 42 and the prism portion 43. The diffractive optical element 42 is an optical lens having an ordinary curved surface, on which remove the material of the multiple of wavelength for the lens thickness direction, and the 2 ^-n-th power of the height of the wave units (n-1) This is a lens pattern approximated by a staircase structure of individual layers.

As the constituent material of the propagation layer 41, a material whose polishing rate in polishing for recessing the propagation layer 41 described later is larger than the constituent material of the unit substrate 230 is selected. For example, when the chemical mechanical polishing (CMP) method is used as this polishing, and the unit substrate 230 is made of AlTiC (Al ₂ O ₃ —TiC), the propagation layer 41 is made of the dioxide dioxide. It may be formed from silicon SiO ₂ or alumina Al ₂ O ₃ . The polishing rate is an amount by which the material is polished by a predetermined polishing operation, and can be expressed by a decrease in thickness in the polishing direction when the layer surface (end surface) of the layer is polished.

The configuration of the diffractive optical element portion 42 will be described later in detail with reference to other drawings. However, the diffractive optical element portion 42 has a higher refractive index n than the material forming the propagation layer 41, and is formed using, for example, a sputtering method. Made of a dielectric material. For example, when the propagation layer 41 is made of silicon dioxide SiO ₂ (n = 1.5), the diffractive optical element portion 42 may be made of alumina Al ₂ O ₃ (n = 1.63). Good. Further, when the propagation layer 41 is made of alumina Al ₂ O ₃ (n = 1.63), the diffractive optical element section 42 is made of tantalum oxide Ta ₂ O ₅ (n = 2.16), niobium oxide Nb. _It may be formed of ₂ O ₅ (n = 2.33), titanium oxide TiO (n = 2.3 to 2.55), or titanium oxide TiO ₂ (n = 2.3 to 2.55). When the diffractive optical element unit 42 has a higher refractive index than the propagation layer 41, the laser light passing through the diffractive optical element unit 42 is adjusted to parallel light or focused light by a lens action based on refraction at the interface. . In addition, the thickness of the propagation layer 41 is, for example, about 30 to 60 μm, and the thickness of the diffractive optical element portion 42 depends on the wavelength of the laser beam as described later, but is, for example, about 0.5 to 5 μm. is there.

The prism portion 43 is formed obliquely with respect to the element formation surface 2302 and changes the traveling direction of the laser light with the layer surface of the propagation layer 41 as the reflection surface 430. For example, when laser beams aligned in parallel by the diffractive optical element unit 42 are incident on the reflecting surface 430 of the prism unit 43 at an incident angle greater than the critical angle, the laser beam is totally reflected by the reflecting surface 430 and is parallel. The traveling direction is changed in the direction of the end face 410 while being aligned. Actually, regardless of whether the propagation layer 41 is formed of SiO ₂ (n = 1.5) or Al ₂ O ₃ (n = 1.63), the atmosphere in the magnetic disk device (refractive index n is about 1). ), A total refractive index is possible. For example, when laser light aligned in parallel by the diffractive optical element unit 42 travels in a direction perpendicular to the element formation surface 2302, the side on the end face 410 side is lifted parallel to the element formation surface 2302. The flat reflection surface 430 is formed at an angle of °, so that the laser light after total reflection can be light having a direction perpendicular to the bonding surface 2300.

  Next, the refractive index adjustment layer 45 of the thin film magnetic head 21 will be described.

As described above, the refractive index adjustment layer 45 is filled at least between the end surface 410 of the propagation layer 41 and the end surface 352 of the waveguide layer 35, and the refractive index is equal to the refractive index value of the propagation layer 41 and the waveguide layer. It is adjusted to a value between the refractive index values of 35. Here, for example, the propagation layer 41 is made of silicon dioxide SiO ₂ (n = 1.5) or alumina Al ₂ O ₃ (n = 1.63), and the waveguide layer 35 is made of tantalum oxide Ta. ₂ O ₅ (n = 2.16), niobium oxide Nb ₂ O ₅ (n = 2.33), titanium oxide TiO (n = 2.3-2.55) or titanium oxide TiO ₂ (n = 2.3) ~ 2.55), the refractive index adjusting layer 45 may be formed of polymethylphenylsilane which is one of high refractive index UV (ultraviolet) curable resins (UV curable adhesives). Good. Polymethylphenylsilane has a refractive index in the thin film state of about 1.69 to 1.71, and is a value between the refractive index value of the propagation layer 41 and the refractive index value of the waveguide layer 35.

  When the refractive index adjusting layer 45 is an adhesive resin having such a high appropriate refractive index, as will be described later, for example, in the fixing process of the slider 22 and the light source unit 23, there is no gap in a certain position. The filled refractive index adjustment layer 45 can be obtained.

  As a modification, the diffractive optical element unit 42 is not on the optical path connecting the laser diode 40 and the prism unit 43 as in the present embodiment, but on the optical path reached after the laser beam is totally reflected by the prism unit 43. It may be provided at a position. Further, the laser diode 40 is not formed in the trench 2003 as in the present embodiment, but is fixed in a state where the electrode on the bottom surface is electrically connected to the element formation surface 2302 of the unit substrate 230. May be. In this case, it is preferable that the laser light is emitted from the light emitting end of the laser diode toward the end surface 410 of the propagation layer 41, passes through a plane lens formed in the propagation layer 41, and the propagation is adjusted.

  As a further modification, the optical path changing unit may be a grating coupler unit instead of the prism unit 43 as in the present embodiment. Furthermore, only the grating coupler unit may be provided as the lens unit and the optical path changing unit. Also in the modified mode described above, it is possible to obtain a laser beam with an appropriate direction and adjusted propagation.

  4A and 4B are schematic views showing the configuration of the laser diode 40 and a method for mounting the laser diode 40 on the unit substrate 230. FIG.

According to FIG. 4A, the laser diode 40 may have the same structure as that normally used for optical disk storage, for example, an n-electrode 40a, an n-GaAs substrate 40b, an n-InGaAlP cladding layer 40c, a first InGaAlP guide layer 40d, an active layer 40e made of multiple quantum wells (InGaP / InGaAlP), a second InGaAlP guide layer 40f, a p-InGaAlP cladding layer 40g, ^* It has a structure in which an n-GaAs current blocking layer 40h, a p-GaAs contact layer 40i, and a p-electrode 40j are sequentially stacked. Reflective films 50 and 51 made of SiO ₂ , Al ₂ O ₃ or the like for exciting oscillation due to total reflection are formed before and after the cleavage planes of these multilayer structures, and the emitted light from which laser light is emitted At the end 400, an opening is provided at the position of the active layer 40e in one reflective film 50.

The wavelength λ _L of the emitted laser light is, for example, about 600 to 650 nm. However, when providing the near-field light generating part 36 on the slider 22 (FIG. 2), it should be noted that there is an appropriate excitation wavelength according to the metal material of the counter metal layer 360 (FIG. 2). For example, when Au is used for the counter metal layer 360, the wavelength λ _{L of the} laser light is preferably near 600 nm. Further, the excitation wavelength depends not only on the type of the metal material but also on the dimension (length) of the metal material. Even with the same material, when the length of the metal pattern is large, the excitation wavelength tends to be long.

  As described above, the size of the laser diode 40 is, for example, about 250 μm wide × 250 μm long (depth) × 65 μm thick. Here, the width of the laser diode 40 can be reduced to, for example, about 100 μm, with the interval between the opposing ends of the current blocking layer 40 h as a lower limit. However, the length of the laser diode 40 is an amount related to the current density and cannot be made so small. In any case, it is preferable that the laser diode 40 has a considerable size in consideration of handling during mounting.

  In driving the laser diode 40, a power source in the magnetic disk device can be used. Actually, the magnetic disk device usually has a power supply of about 2 V, for example, and has a sufficient voltage for the laser oscillation operation. The power consumption of the laser diode 40 is, for example, about several tens of mW, and can be sufficiently covered by the power supply in the magnetic disk device.

  According to FIG. 4B, the laser diode 40 is mounted on a trench 2003 formed on the unit substrate 230, and one electrode is soldered by an AuSn alloy 52 which is one of lead-free solders. It is fixed while being electrically connected to the bottom surface of the digging 2003. Here, the unit substrate 230 is made of, for example, Altic and has conductivity. In actual fixing, for example, an AuSn alloy vapor deposition film having a thickness of about 0.7 to 1 μm is formed on the bottom surface of the trench 2003, and after placing the laser diode 40, it is heated by a hot plate or the like 200 under a hot air blower. You may fix by heating to about -300 degreeC. The electrode connected to the bottom surface of the trench 2003 may be the n electrode 40a or the p electrode 40j.

  Here, when soldering with the above-described AuSn alloy, the light source unit is heated to a high temperature of about 300 ° C., for example. According to the present invention, the light source unit is manufactured separately from the slider. The magnetic head element in the slider is not affected by this high temperature.

  The drive terminal electrode 440 is formed on the unit upper surface 2301 of the unit substrate 230 through a base layer made of Ta, Ti or the like having a thickness of about 10 nm, and using a sputtering method or the like having a thickness of about 1 to 3 μm. And formed of a layer of Au, Cu or the like. Further, the drive terminal electrode 441 is formed on the other unsoldered electrode of the laser diode 40 through a base layer made of Ta, Ti or the like having a thickness of about 10 nm. It consists of a layer made of Au, Cu or the like having a thickness of about 3 μm, for example, formed by sputtering or the like.

  Of course, the laser diode 40 and the drive terminal electrodes 440 and 441 are not limited to the above-described embodiment. For example, the laser diode 40 may have other configurations using other semiconductor materials such as a GaAlAs system. It may be. Further, it is possible to use other brazing material for soldering the electrodes of the laser diode 40. Furthermore, the drive terminal electrode may be formed by insulating both electrodes of the laser diode 40 from the unit substrate. Furthermore, the laser diode 40 may be formed by epitaxially growing a semiconductor material directly on the unit substrate.

  FIG. 5A is a schematic diagram for explaining the principle of the diffractive optical element unit 42, and FIG. 5B is a unit upper surface 2301 of the light source unit 23 of the propagation layer 41 including the diffractive optical element unit 42. It is sectional drawing by a surface parallel to.

First, the principle of the diffractive optical element unit 42 will be described. First, in an optical convex lens having a normal curved surface as in the cross section shown in FIG. 5 (A-1), the wavelength of the laser light in the lens thickness direction as in the cross section shown in FIG. 5 (A-2). Delete multiple materials. Next, as shown in the cross section of FIG. 5A-3, for example, a stepped structure including three layers with the height of a quarter wavelength of the laser light as a unit is illustrated in FIG. 5A-2. Approximate the cross section discretely. In general, the number of layers of the staircase structure is (n−1) when the height of the wavelength is the power of 2− ⁿ . The staircase structure portion having a cross section as shown in FIG. 5A-3 is the diffractive optical element portion 42, which is equivalent to the lens having the cross section shown in FIG. 5A-1. It will have a function.

  According to FIG. 5B, the diffractive optical element unit 42 is formed by appropriately stacking annular first, second, and third diffraction grating layers 420, 421, and 422 stacked in parallel to the integration surface. A laminate pattern having a cross section corresponding to FIG. The thickness of the diffractive optical element portion 42 can be reduced to be equal to or less than the wavelength of the laser light at the center portion thereof. That is, the diffractive optical element portion 42 can be made thin in a planar shape using a thin film microfabrication technique, and thus is very suitable for adjusting the propagation of the light source unit. Note that the diffractive optical element portion 42 in the figure is a case where the height of the quarter wavelength of the laser beam is set as a unit as described above, but it is natural that the diffractive optical element portion 42 has a height of ½ wavelength, 1/8 wavelength or the like. A diffractive optical element portion may be formed in units of thickness.

Here, a method of forming the diffractive optical element portion 42 will be described. In FIG. 5B, on the first propagation layer 41a made of SiO ₂ formed on the element formation surface 2302 of the unit substrate 230, for example, using the sputtering method or the like, for example, the sputtering method or the like. Is used to form a TiO ₂ film having a predetermined thickness. Next, after a predetermined pattern made of NiFe or the like is formed on the TiO ₂ film, for example, etching using an RIE method using a chlorine-based gas is performed using the pattern of NiFe or the like as a mask, and the first diffraction grating Layer 420 is formed. Next, the second diffraction grating layer 421 and the third diffraction grating layer 422 are sequentially stacked to form the diffractive optical element unit 42 by using a method similar to the method of forming the first diffraction grating layer 420. Complete the formation. Thereafter, an SiO ₂ film is formed by using, for example, a sputtering method so as to cover the formed diffractive optical element portion 42, and then this film surface is planarized by using a CMP method or the like to perform the second propagation. The formation of the propagation layer 41 is completed by forming the layer 41b.

  Note that the diffractive optical element portion has a first diffractive optical element portion for adjusting the spread of the laser light in the track width direction and a direction perpendicular to the laser light adhesion surface 2300 (a direction perpendicular to the drawing sheet). It may be an optical system combined with a second diffractive optical element unit for adjusting the spread.

  6A is a flowchart schematically showing an embodiment of the slider processing bar and slider 22 forming method according to the present invention, and FIG. 6B is a unit processing bar and light source unit 23 according to the present invention. It is a flowchart which shows one Embodiment of the formation method of this.

  First, a manufacturing method of the slider processing bar and the slider 22 will be described. According to FIG. 6A, first, the MR effect element 33 is formed on the integration surface of the slider wafer substrate (step SS1). Next, the near-field light generator 36 is formed (step SS2), and then the waveguide layer 35 is formed (step SS3). Next, if necessary, a backing coil portion is formed (step SS4). Next, the electromagnetic coil element 34 for writing data is formed (step SS5), and then the coating layer 38 and the signal terminal electrode 37 are formed (step SS6). Thus, the wafer thin film process for mainly forming the magnetic head element pattern including the magnetic head element 32, the waveguide layer 35, the near-field light generating portion 36, and the signal terminal electrode 37 on the wafer substrate is completed.

  Next, the wafer substrate after the wafer thin film process is cut, and a slider processing bar is cut out (step SS7). Thereafter, MR height processing is performed on the slider processing bar (step SS8). Next, a protective film is formed on the slider end surface on the ABS side (step SS9). Thereafter, a process of forming a rail on the ABS is performed (step SS10). Thus, the manufacturing process of the slider processing bar is completed. Thereafter, when the slider processing bar and the unit processing bar are fixed in manufacturing the thin film magnetic head 21, the manufactured slider processing bar is used.

  On the other hand, when the slider 22 is used for manufacturing the thin film magnetic head 21 thereafter, the processing bar is cut and separated into individual sliders 22 (step SS11). Thus, the machining process is completed and the manufacturing process of the slider 22 is completed.

  Next, a method for manufacturing the unit processing bar and the light source unit 23 will be described. According to FIG. 6B, first, the first propagation layer 41a is formed on the element formation surface of the wafer substrate for the light source unit (step SU1). Next, the diffractive optical element unit 42 is formed (step SU2), and then the second propagation layer 41b is formed (step SU3). Thus, the wafer thin film process for forming the diffractive optical element portion 42 on the wafer substrate is completed.

  Next, the wafer substrate after the wafer thin film process is cut, and a unit processing bar is cut out (step SU4). Thereafter, the prism layer 43 is formed by grinding the layer to be the propagation layer 41 (step SU5). Next, a recess 2003 is formed in the unit processing bar (step SU6), and the laser diode 40 is mounted on the formed recess 2003 (step SU7). Thereafter, drive terminal electrodes 440 and 441 are formed (step SU8). Note that the order of the formation process of the prism portion 43 (step SU5) and the formation process of the engraving 2003 (step SU6) may be reversed. However, the mounting of the laser diode 40 (step SU7) is preferably after the step of forming the prism portion 43 (step SU5) is completed.

  Here, when the slider processing bar and the unit processing bar are fixed in the manufacture of the thin film magnetic head 21, the characteristic inspection of the laser diode 40 is performed (step SU10 '), and the unit processing bar determined to be non-defective in this inspection is obtained. Used in subsequent manufacturing processes. Thereafter, in the unit processing bar in which all the laser diodes are determined to be non-defective products, the end surface on the side to which the layer to be the propagation layer 41 is bonded is from the bar bonding surface which is the surface to which the substrate portion of the unit processing bar is bonded Retreat (recess) (step SU11 ′). Thus, the manufacturing process of the unit processing bar is completed. Note that the recessing step (step SU11 ′) may be performed first, and then the characteristic inspection (step SU10 ′) may be performed at the retracted end surface position.

  On the other hand, when the light source unit 23 is used for manufacturing the thin film magnetic head 21 thereafter, the unit processing bar is cut and separated into the individual light source units 23 (step SU9). Thereafter, a characteristic inspection of the laser diode 40 is performed (step SU10). In this inspection, only the light source unit 23 in which the mounted laser diode is determined to be non-defective is used in the subsequent manufacturing process. Next, in the light source unit 23 in which the laser diode is determined to be non-defective, the end surface of the propagation layer 41 on the adhesive surface 2300 side is retracted (recessed) from the adhesive surface 2300 (step SU11). Thus, the machining process is completed, and the manufacturing process of the light source unit 23 is completed. Note that the recessing step (step SU11) may be performed first, and then the characteristic inspection (step SU10) may be performed at the position of the retracted end surface 410.

Further, in the manufacture of the thin film magnetic head 21, in both cases where the slider processing bar and the unit processing bar are fixed and when the light source unit 23 is used, a recessing step (step SU11 ′ or instead of step SU11), (step SU _R), the unit machining bar-cutting process step (step SU4) immediately after (Fig. 6 (B) recessing process layers of the propagation layer be performed on the position of SU _R) of Good. The recessing step (step SU _R ) may be performed at any point from immediately after the unit processing bar cutting step (step SU4) to immediately after the drive terminal electrode forming step (step SU8).

  FIG. 7A is a flowchart schematically showing an embodiment of a method of manufacturing a thin film magnetic head 21 for fixing the slider 22 and the light source unit 23 according to the present invention, and FIG. 3 is a flowchart schematically showing an embodiment of a method for manufacturing a thin film magnetic head 21 for fixing a slider processing bar and a unit processing bar.

  First, a method for manufacturing the thin film magnetic head 21 to which the slider 22 and the light source unit 23 are fixed will be described. 7A, first, the surface of the slider 22 opposite to the ABS (the back surface 2201 and the slider end surface 222) and the surface of the light source unit 23 on the bonding surface 2300 side (the bonding surface 2300 and the end surface 410). The high refractive index UV curable resin described above is applied in advance to both or either one (step S1).

  Next, the surface of the slider 22 opposite to the ABS and the surface of the light source unit 23 on the adhesive surface 2300 side are brought into contact with each other, and at least between the end surface 410 of the propagation layer 41 and the end surface 352 of the waveguide layer 35. The high refractive index UV curable resin is filled, and alignment is performed so that light emitted from the end face 410 of the propagation layer 41 propagates through the waveguide layer 35 and reaches the slider end face 221 on the ABS side (step S2). ). Finally, the slider 22 and the light source unit 23 are fixed by irradiating ultraviolet rays (step S3), thereby completing the manufacturing process of the thin film magnetic head 21.

  Next, a method for manufacturing the thin film magnetic head 21 for fixing the slider processing bar and the unit processing bar will be described. According to FIG. 7B, first, the above-described high refractive index UV curable resin is applied in advance to either or either of the slider processing bar and the unit processing bar to be bonded (step S1 ′). Next, the slider processing bar and the unit processing bar are brought into contact with each other, and a high refractive index is provided between the end surface on the bar bonding surface side of the layer serving as the propagation layer 41 and the end surface 352 of the waveguide layer 35. The alignment is performed so that the light radiated from the end surface 410 of the propagation layer 41 propagates through the waveguide layer 35 and reaches the slider end surface 221 on the ABS side (step S2 ′). Thereafter, the slider processing bar and the unit processing bar are fixed by irradiating with ultraviolet rays (step S3 ′). Finally, by cutting and separating the fixed processing bar (step S4 ′), the manufacturing process of the thin film magnetic head 21 is completed.

  Hereinafter, an embodiment of a method of manufacturing the thin film magnetic head shown in the above-described flowchart will be further described in detail with reference to the drawings.

  8A to 8E are schematic views showing an embodiment of a slider processing bar and a method for forming the slider 22 according to the present invention.

  As shown in FIG. 8A, a large number of magnetic head element patterns 71 are formed in a matrix on the element forming surface of a slider wafer 70, which is a wafer substrate on which the wafer thin film process of the slider has been completed. Yes. The magnetic head element pattern 71 is a part of the formed slider 22 that mainly becomes the MR effect element 33, the electromagnetic coil element 34, the waveguide layer 35, the near-field light generator 36, and the signal terminal electrode 37.

  First, the slider wafer 70 is cut by bonding to a cutting and separating jig using resin or the like, and as shown in FIG. 8B, slider processing in which a plurality of magnetic head element patterns 71 are arranged in a line. Cut out the bar 72. Next, the slider processing bar 72 is adhered to a polishing jig using a resin or the like, and the MR height (MR height) of the MR effect element, that is, the slider is formed on the end surface 720 on the ABS side of the slider processing bar 72. Polishing is performed as an MR height process for determining a length in a direction perpendicular to the end face 221. In this MR height processing, as shown in FIG. 8C, the magnetic head element 32 and the near-field light generator 36 are finally exposed to the slider end surface 221, and the MR multilayer 332 of the MR effect element 33 is formed. The process is performed until the MR height reaches a predetermined MR height and the near-field light gap 361 of the near-field light generator 36 reaches a predetermined height (length in a direction perpendicular to the slider end surface 221).

  Next, a protective film made of, for example, diamond-like carbon (DLC) for protecting the end of the magnetic head element is formed on the slider end surface 221. Thereafter, the slider processing bar 72 on which the protective film is formed is adhered to a rail forming jig using a resin or the like, and ABS is used using a photolithography method, an ion milling method, a reactive ion etching (RIE) method, or the like. A process for forming a rail is performed to complete the slider processing bar 73 as shown in FIG.

  On the other hand, when the slider 22 is used for manufacturing the thin film magnetic head 21 thereafter, the slider processing bar 73 is bonded to a cutting jig using a resin or the like, and after grooving, Cutting processing is performed, and the slider processing bar 73 is cut and separated to complete the slider 22 as shown in FIG.

  9A to 9I are schematic views showing an embodiment of a method of forming the unit processing bar and the light source unit 23 according to the present invention.

  According to FIG. 9A, first, the dielectric film 80 and the diffractive optical element portion 42 to be the propagation layer 41 are formed on the substrate wafer to be the unit substrate. At this time, the constituent material of the dielectric film 80 is selected so that the polishing rate in the polishing for the recess using the CMP method or the like to be performed later becomes larger than the constituent material of the substrate wafer. Next, the unit wafer 81 on which the dielectric film 80 and the diffractive optical element portion 42 are formed is cut by bonding to a cutting / separating jig using a resin or the like, as shown in FIG. The unit processing bar 82 in which the diffractive optical element portions 42 are aligned is cut out. Note that the interval at which the diffractive optical element portion 42 is formed is the same as the interval between the magnetic head element patterns 71 formed on the slider wafer 70 (FIG. 8A), and is in the track width direction of the unit processing bar 82. The width is set to be the same as the width of the slider processing bar 72 in the same direction.

  Next, the edge of the dielectric film 80 of the unit processing bar 82 is polished by being pressed against a polishing means such as a grindstone at a predetermined angle. The polished surface at this time will later become the reflective surface 430. The inclination angle of the reflective surface 430 is controlled by a predetermined angle to be pressed during polishing. Next, as shown in FIG. 9C, the engraving 2003 is formed on the surface of the unit processing bar 82 that becomes the unit upper surface 2301 of the light source unit 23 using a photolithographic method, an ion milling method, an RIE method, or the like. Form.

  Next, as shown in FIG. 9C, the laser diode 40 is mounted on the formed recess 2003 using soldering with an AuSn alloy as described above. Thereafter, as shown in FIG. 9D, drive terminal electrodes 440 and 441 for the laser diode 40 are formed, and a unit processing bar 83 is formed.

  Here, when the slider processing bar 73 (FIG. 9 (D)) and the unit processing bar 83 are fixed in the manufacture of the thin film magnetic head 21, they are mounted on the unit processing bar 83 as shown in FIG. 9 (E). The characteristics of the laser diode 40 are inspected. In the characteristic inspection, the inspection probe 84 is brought into contact with the drive terminal electrodes 440 and 441 to actually drive the laser diode 40, and a light-receiving element 85 such as a photodiode is used to form a dielectric that becomes the slider end surface 221 on the ABS side. This is done by detecting laser light emitted from the end face 86 of the film 80.

  The inspection items include the radiation intensity at the end face 86 (the light emission intensity of the laser diode 40), the radiation position at the end face 86, the life of the laser diode 40, and the like. In this characteristic inspection, only the unit processing bar in which all the mounted laser diodes are determined as non-defective products is used in the subsequent manufacturing process. However, as one modification, the laser diode determined as a defective product is all specified, the slider processing bar and the unit processing bar are fixed and cut and separated, and then the specified laser diode is provided. The thin film magnetic head may be removed as a defective product.

  Next, as shown in FIG. 9F, when this unit processing bar 83 is used for manufacturing the thin film magnetic head 21, a recess using a CMP method or the like is applied to the bar bonding surface side of the unit processing bar 83. For polishing. Here, as described above, since the polishing rate of the dielectric film 80 is set to be larger than the polishing rate of the substrate wafer, the end surface on the bar bonding surface 89 side of the dielectric film 80 is obtained by this polishing. 88 will retreat from the bar adhesive surface 89. Thus, the manufacture of the unit processing bar 83 is completed.

  On the other hand, when the light source unit 23 is used to manufacture the thin film magnetic head 21 thereafter, the unit processing bar 83 is bonded to a cutting jig using a resin or the like, and after grooving, A cutting process is performed, and the light source unit 23 is separated as shown in FIG. Thereafter, as shown in FIG. 9H, the characteristic inspection of the laser diode 40 mounted on the light source unit 23 is performed. In the characteristic inspection, the inspection probe 84 is brought into contact with the drive terminal electrodes 440 and 441 to actually drive the laser diode 40, and the end face 87 on the adhesion surface side of the propagation layer 41 using the light receiving element 85 such as a photodiode. This is performed by detecting laser light emitted from the laser beam. Here, in this inspection, only the light source unit 23 in which the mounted laser diode is determined to be non-defective is used in the subsequent manufacturing process.

  Next, as shown in FIG. 9I, the surface on the bonding surface side of the light source unit 23 is polished for recession using a CMP method or the like. Here, as described above, the polishing rate of the dielectric film 80, that is, the propagation layer 41 is set to be larger than the polishing rate of the substrate wafer, that is, the unit substrate 230. Thus, the end surface 410 on the bonding surface 2300 side of 41 is retracted from the bonding surface 2300. Thus, the manufacture of the light source unit 23 is completed. Note that the process for generating such a recess is not limited to polishing, and may be dry etching such as ion beam etching (IBE) or wet etching using an alkaline solution.

  10A to 10C are schematic views showing an embodiment of a method of manufacturing a thin film magnetic head 21 for fixing the slider 22 and the light source unit 23 according to the present invention.

  10A, first, both the surface of the slider 22 opposite to the ABS (the back surface 2201 and the slider end surface 222) and the surface of the light source unit 23 on the bonding surface 2300 side (the bonding surface 2300 and the end surface 410). Alternatively, the above-described high refractive index UV curable resin 90 is applied in advance to either one. Next, as shown in FIG. 10B, the surface on the side opposite to the ABS of the slider 22 and the surface on the adhesive surface 2300 side of the light source unit 23 are brought into contact with each other, and at least the end surface 410 of the propagation layer 41 is guided. The high refractive index UV curable resin 91 is filled with the end face 352 of the waveguide layer 35, and the light emitted from the end face 410 of the propagation layer 41 propagates through the waveguide layer 35 and the slider end face 221 on the ABS side. Align to reach. Finally, as shown in FIG. 10C, the thin film magnetic head 21 is formed by irradiating the contacted portion with ultraviolet rays, fixing the slider 22 and the light source unit 23, and forming the refractive index adjustment layer 45. The manufacturing process is completed.

  FIGS. 11A to 11D are schematic views showing an embodiment of a method of manufacturing a thin film magnetic head 21 for fixing a slider processing bar and a unit processing bar according to the present invention.

  11A, first, the surface 7301 of the formed slider processing bar 73 opposite to the surface to be ABS, the end surface 88 of the dielectric film 80 of the formed unit processing bar 83, and the bar bonding. The high refractive index UV curable resin 92 described above is applied in advance to either or both of the surface 89. Next, as shown in FIG. 11B, the high refractive index UV curable resin 93 is filled between the end surface 88 and the end surface 352 of the waveguide layer 35, and is emitted from the end surface 410 of the propagation layer 41. Positioning is performed so that the light propagates through the waveguide layer 35 and reaches the slider end surface 221 on the ABS side.

  Thereafter, as shown in FIG. 11C, the contacted portion is irradiated with UV (ultraviolet rays), and the slider processing bar 73 and the unit processing bar 83 are fixed. Finally, as shown in FIG. 11 (D), the fixed processing bar is bonded to a cutting jig using a resin or the like, grooved, and then cut and separated. The manufacturing process of the thin film magnetic head 21 provided with the rate adjusting layer 45 is completed.

  As described above, the refractive index adjustment layer in which the refractive index is adjusted to a value between the refractive index value of the propagation layer 41 and the refractive index value of the waveguide layer 35 by any of the manufacturing methods described with reference to FIGS. 45 is provided so as to be filled at least between the end face 410 of the propagation layer 41 and the end face 352 of the waveguide layer 35, and the air layer therebetween is excluded. Therefore, the laser beam propagates through an appropriate environment where there is no great difference in refractive index. As a result, reflection between the propagation layer 41 and the waveguide layer 35 can be suppressed to a very small level. Thereby, the fall of the oscillation characteristic of the laser diode 40 can be prevented.

  All the embodiments described above are illustrative of the present invention and are not intended to be limiting, and the present invention can be implemented in other various modifications and changes. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

1 is a perspective view schematically showing a configuration of a main part in an embodiment of a magnetic disk device and an HGA according to the present invention. 1 is a perspective view showing an embodiment of a light source unit according to the present invention and a thin film magnetic head including the light source unit. FIG. 2 is a cross-sectional view taken along the line AA in FIG. 2 schematically showing the configuration of the main part of the thin film magnetic head shown in FIG. 2, and a plan view showing the shape of the end of the magnetic head element and the slider end face of the near-field light generator. It is. It is the schematic which shows the structure of a laser diode, and the mounting method to the unit board | substrate of a laser diode. It is the schematic for demonstrating the principle of a diffractive optical element part, and sectional drawing by the surface parallel to the unit upper surface of the light source unit of the propagation layer containing a diffractive optical element part. 1 is a flowchart schematically showing an embodiment of a slider processing bar and a method for forming a slider according to the present invention, and a flowchart schematically showing an embodiment of a method for forming a unit processing bar and a light source unit according to the present invention. 1 is a flowchart schematically showing an embodiment of a method of manufacturing a thin film magnetic head for fixing a slider and a light source unit according to the present invention; and FIG. 2 is a flowchart of a method of manufacturing a thin film magnetic head for fixing a slider processing bar and a unit processing bar according to the present invention. 3 is a flowchart schematically illustrating an embodiment. It is the schematic which shows one Embodiment of the formation method of the slider processing bar and slider by this invention. It is the schematic which shows one Embodiment of the formation method of the unit processing bar and light source unit by this invention. It is the schematic which shows one Embodiment of the manufacturing method of the thin film magnetic head which adheres a slider and a light source unit by this invention. It is the schematic which shows one Embodiment of the manufacturing method of the thin film magnetic head which adheres a slider processing bar and a unit processing bar by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Magnetic disk 11 Spindle motor 12 Assembly carriage apparatus 13 Recording / reproduction | regeneration and light emission control circuit 14 Drive arm 15 Voice coil motor (VCM)
16 Pivot bearing shaft 17 Head gimbal assembly (HGA)
20 Suspension 200 Load beam 201 Flexure 202 Base plate 203 Wiring member 21 Thin film magnetic head 22 Slider 220 Slider substrate 2200 ABS
2201 Rear surface 2202 Integrated surface 221, 222 Slider end surface 23 Light source unit 230 Unit substrate 2300 Adhesive surface 2301 Unit upper surface 2302 Element formation surface 32 Magnetic head element 33 MR effect element 330 Lower shield layer 332 MR laminate 334 Upper shield layer 34 Electromagnetic coil element 340 Main magnetic pole layer 340a End portion 341 Gap layer 342 Coil layer 343 Coil insulation layer 344 Auxiliary magnetic pole layer 35 Waveguide layer 350 Condensing surface 351 Side surface 352 End surface 36 Near-field light generating portion 360 Opposing metal layer 361 Near-field light gap portion 37 Signal terminal electrode 38 Cover layer 39 Laser light 40 Laser diode 400 Output end 41 Propagation layer 410 End face 42 Diffractive optical element part 43 Prism part 430 Reflective surface 440, 441 Drive terminal electrode 45 Refractive index adjustment layer 8 Inter-element shield layer 50, 51 Reflective film 52 AuSn alloy 70 Slider wafer 71 Magnetic head element pattern 72, 73 Slider processing bar 7301 Surface opposite to the surface to be ABS 720 End surface 80 Dielectric film 81 Unit wafer 82, 83 Unit processing bar 84 Inspection probe 85 Light receiving element 86, 87, 88 End face 89 Bar adhesive surface 90, 91, 92, 93 High refractive index UV curable resin

Claims (17)

A unit substrate having an adhesive surface bonded to a surface opposite to the air bearing surface of the slider, a light source provided on the unit substrate, and an adhesive surface of the unit substrate are provided on a vertical element forming surface. A propagation layer including an optical path of light emitted from the light source and reaching its end face on the adhesion surface side, and provided in the propagation layer, for adjusting propagation of light emitted from the light source With a lens part,
A light source unit for heat-assisted magnetic recording, wherein an end surface of the propagation layer on the adhesive surface side is in a position retracted from the adhesive surface.   As an optical path changing part for directing the light to the end face on the adhesion surface side of the propagation layer, a prism part using a layer surface of the propagation layer that is formed obliquely with respect to the element formation surface as a reflection surface The light source unit according to claim 1, further comprising:   The light source unit according to claim 1, wherein the lens unit is a diffractive optical element unit.   The light source is a laser diode, and the laser diode is provided in a recess formed on the surface opposite to the bonding surface of the unit substrate and extending to the element formation surface. The end is exposed without being blocked by the unit substrate, and the unit substrate has conductivity, and the electrode forming the bottom surface of the laser diode is electrically connected to the unit substrate. The light source unit according to claim 1, wherein the light source unit is a light source unit.   5. A unit processing bar, wherein each chip after separation becomes the light source unit according to claim 1 by being cut and separated. A slider substrate having the air bearing surface and an integrated surface perpendicular to the air bearing surface; a magnetic head element provided on the integrated surface; and receiving the light from its own end surface opposite to the air bearing surface. A slider provided with a waveguide layer for propagating toward the slider end surface on the side, and a coating layer provided on the integrated surface so as to cover the magnetic head element and the waveguide layer;
The adhesive surface is in contact with the surface opposite to the air bearing surface of the slider, and light emitted from the end surface on the adhesive surface side of the propagation layer propagates through the waveguide layer to the air bearing surface side. The light source unit according to any one of claims 1 to 4, wherein the light source unit is fixed so as to reach a slider end surface.
A refractive index adjustment layer is provided at least between the end surface on the adhesion surface side of the propagation layer that emits the light and the end surface opposite to the air bearing surface of the waveguide layer that receives the light. Thin film magnetic head featuring   The refractive index adjusting layer is formed of a UV curable resin, and the refractive index of the UV curable resin is a value between the refractive index value of the propagation layer and the refractive index value of the waveguide layer. The thin film magnetic head according to claim 6.   8. The propagation layer according to claim 7, wherein the propagation layer is silicon dioxide or alumina, the waveguide layer is tantalum oxide, niobium oxide, or titanium oxide, and the refractive index adjustment layer is polymethylphenylsilane. The thin film magnetic head described.   The slider is provided at a position in contact with or close to the end surface on the air bearing surface side of the waveguide layer, and generates a near-field light to heat the magnetic recording medium when writing a data signal. 9. The thin film magnetic head according to claim 6, further comprising a near-field light generating portion having an end reaching the slider end surface on the air bearing surface side.   A thin film magnetic head according to any one of claims 6 to 9, a support mechanism that supports the thin film magnetic head, a signal line for the magnetic head element, and a power supply line for the light source. A head gimbal assembly characterized by that.   At least one head gimbal assembly according to claim 10 is provided, and controls at least one magnetic recording medium and writing and reading operations performed by the thin film magnetic head on the at least one magnetic recording medium, A magnetic disk apparatus, further comprising a recording / reproducing and light emission control circuit for controlling a light emission operation of the light source. A unit substrate having an adhesive surface, a light source provided on the unit substrate, and an adhesive surface of the unit substrate are provided on a device forming surface perpendicular to the unit substrate. Forming a light source unit including a propagation layer including an optical path of light reaching the end face of the lens, and a lens unit;
After the light source unit is formed or before the light source unit is cut and separated from the unit processing bar, the end surface of the propagation layer or the layer to be the propagation layer on the bonding surface side or the bar bonding surface side is the bonding surface or the bar. Retreat from the adhesive surface,
A slider substrate having an air bearing surface and an integrated surface perpendicular to the air bearing surface, a magnetic head element provided on the integrated surface, and receiving the light from its own end surface opposite to the air bearing surface, the air bearing surface side Forming a slider including a waveguide layer for propagating toward the slider end surface, and a coating layer provided on the integrated surface so as to cover the magnetic head element and the waveguide layer;
An adhesive resin is applied to the surface of the light source unit on the bonding surface side and / or the surface of the slider opposite to the floating surface, and the bonding surface side surface and the floating surface are opposite to each other. The adhesive resin is filled between at least the end face on the adhesive face side of the propagation layer and the end face on the opposite side of the air bearing surface of the waveguide layer, The light source unit and the slider are fixed after positioning so that the light emitted from the end surface on the adhesion surface side of the propagation layer propagates through the waveguide layer and reaches the slider end surface on the air bearing surface side. A method of manufacturing a thin film magnetic head.   As a constituent material of the propagation layer, a material having a polishing rate larger than that of the constituent material of the unit substrate is selected, and then the surface on the adhesive surface side of the light source unit is polished, thereby The manufacturing method according to claim 12, wherein the end surface is retracted from the bonding surface.   As the adhesive resin, a UV curable resin having a refractive index between the refractive index value of the propagation layer and the refractive index value of the waveguide layer is selected. The method according to claim 12 or 13, wherein after the coating, the contact surface between the light source unit and the slider is fixed by irradiating with ultraviolet rays. By being cut and separated, each separated chip has a unit substrate having an adhesive surface, a light source that emits light, and a propagation layer that propagates the light formed on an element formation surface perpendicular to the adhesive surface. And a light source unit for heat-assisted magnetic recording provided with a lens part, forming a unit processing bar having a bar bonding surface that becomes the bonding surface by being cut and separated,
After the unit processing bar is formed or before the light source is provided on the unit processing bar, the end surface on the bar bonding surface side of the layer serving as the propagation layer is cut back from the bar bonding surface by cutting and separating. ,
By cutting and separating, each separated chip has a floating surface and a slider substrate having an integrated surface perpendicular to the floating surface, a magnetic head element provided on the integrated surface, and the light to the floating surface. The slider is provided with a waveguide layer that is received from its own end surface opposite to the substrate and propagates toward the slider end surface on the air bearing surface side, and a covering layer that covers the magnetic head element and the waveguide layer. Form the slider processing bar,
A bonding resin is applied to both or one of the surface on the bar bonding surface side of the unit processing bar and the surface on the side opposite to the air bearing surface of the slider processing bar, and the surface on the bar bonding surface side And a surface opposite to the surface to be the air bearing surface, at least an end surface of the layer serving as the propagation layer on the bar bonding surface side and an end surface on the opposite side of the air bearing surface of the waveguide layer So that the light emitted from the end face on the adhesive surface side of the propagation layer propagates through the waveguide layer and reaches the slider end face on the air bearing surface side. A method of manufacturing a thin film magnetic head comprising: fixing the unit processing bar and the slider processing bar, and then cutting and separating the fixed unit processing bar and the slider processing bar.   As the constituent material of the layer to be the propagation layer, a material having a polishing rate larger than that of the constituent material of the unit substrate is selected and then the propagation layer is polished by polishing the surface of the unit processing bar on the bar bonding surface side. The manufacturing method according to claim 15, wherein an end surface of the layer to be formed on the bar bonding surface side is retracted from the bar bonding surface.   As the adhesive resin, a UV curable resin having a refractive index that is between the refractive index value of the layer serving as the propagation layer and the refractive index value of the waveguide layer is selected. The manufacturing method according to claim 15 or 16, wherein after the resin is applied, the contact surface between the unit processing bar and the slider processing bar is fixed by irradiation with ultraviolet rays.

Images