JP2008059669A - Thin film magnetic head with heater - Google Patents

Abstract

In a thin film magnetic head equipped with a heater, when the heater is over-energized, electromigration occurs between the heater resistance wire and the insulator, the heater resistance value changes, and the heater energization life is reduced. This causes a problem that the resistance wire is disconnected.
A thin film magnetic head (1) includes a heater (4) adjacent to a lower magnetic shield layer (5). The heater 4 is a meandering resistance wire 40. The resistance wire 40 is a laminated film of a NiCr thin film 41 and a Ta thin film 42, and the Ta thin film 42 is arranged above and below the NiCr thin film 41 so as to sandwich the NiCr thin film 41. When comparing the current resistance of Ta and NiCr, the so-called electromigration resistance, Ta, which is a refractory metal, is significantly superior. By adopting a structure in which the NiCr thin film 42 is sandwiched between such Ta thin films 42, resistance is improved. The electromigration resistance of the line 40 itself is greatly improved.
[Selection] Figure 4A

Description

  The present invention relates to a thin film magnetic head mounted on a magnetic recording apparatus, and more particularly to a thin film magnetic head provided with a heater for controlling a flying height on a magnetic recording medium.

  In recent years, the recording density of magnetic recording devices has been dramatically increased. This is because the gap between the magnetic recording medium and the magnetic head, which is one of the main technologies for realizing it, that is, the flying height of the magnetic head is extremely high. This is largely due to the small size. However, as the flying height decreases, the probability of collision between the medium and the head increases, and various problems such as generation of thermal asperity, attenuation of head output, and increase of head noise are becoming apparent. For this reason, a technique for reducing the gap only when recording a signal on the medium or reproducing the signal of the medium is used while controlling the flying height between the medium and the head to such an extent that the above problems do not occur. Magnetic recording heads and magnetic recording apparatuses have been proposed.

  As such a prior art, for example, Patent Document 1 discloses an electromagnetic induction type magnetic head and a magnetic disk device in which a thin film resistor (heater) is embedded in a head and the amount of flying is varied by generating heat. Yes. Patent Document 2 discloses that a signal recording unit and a signal reproducing unit that detects a signal recorded on a magnetic recording medium using a magnetoresistive effect are separated, and the flying height between the magnetic recording medium and the head is determined. A magnetoresistive head and a magnetic disk device provided with a heater for control are disclosed. Further, Patent Document 3 describes a magnetic head slider and a magnetic disk device that provide a heater at a position that does not raise the temperature of the magnetoresistive element and control the flying height.

  In the above prior art, regarding the control of the optimum energization amount necessary for heating the thin film resistor, the head and the medium are detected, the head output level is detected, the head output level is detected. Various methods are employed such as contact or line contact, or detection of the temperature in the vicinity of the head and conversion of the temperature into information on the flying height.

  On the other hand, regarding the structure of the heater, Patent Document 4 discloses that the heating part of the heater member has a two-layer structure of a heater layer having a low specific resistance and a cap layer having a high specific resistance, so that the resistance value of the entire heater member is reduced. A technique for reducing the variation is disclosed. Patent Document 5 forms a temperature gradient relaxation material having a higher thermal conductivity than the heater (alumina) that fills the periphery of the heater in the vicinity of the heater. A technique for reducing disconnection due to migration is disclosed.

JP-A-5-20635 JP 2003-272335 A JP 2004-241092 A Japanese Patent Laid-Open No. 2004-280887 JP 2006-53972 A

  As described above, in the prior art, as a method for determining the energization amount necessary to generate heat in the thin film resistor (heater), the contact between the head and the medium is detected, the output level of the head is detected, and the head and the medium Are point contact or line contact, or the temperature in the vicinity of the head is detected and converted into the flying height information. However, the method of detecting contact between the head and the medium, or making the point and line contact between the head and the medium has a large damage to the head due to the contact, which may hinder subsequent use of the head. There's a problem. In the method of detecting the output level of the head, or detecting the temperature in the vicinity of the head and converting this to information on the flying height, the individual heads caused by lots, wafers, wafers, and processing processes, etc. Therefore, depending on the head, the heater is energized until a desired output is obtained unless the head contacts the medium. In this case, the temperature of the magnetoresistive element portion of the magnetoresistive head is significantly increased, resulting in a significant decrease in the energization life of the element. In addition, the heater itself is excessively energized, electromigration occurs between the resistance wire and the insulator, and the metal component of the resistance wire moves preferentially at the interface with the insulating layer. The resistance value changes (increases). When the resistance value of the resistance wire increases, the amount of heat generation increases with respect to the same energization amount, so that the flying height of the head cannot be accurately controlled, and the energization life of the heater also decreases. In addition, due to electromigration, the resistance wire may be deteriorated more than expected, and in this case, the resistance wire is disconnected.

  An object of the present invention is to improve electromigration resistance of a heater resistance wire in a thin film magnetic head incorporating a heater.

  The thin film magnetic head of the present invention includes a reproducing head in which a magnetoresistive effect element is provided between a lower magnetic shield layer and an upper magnetic shield layer, and a recording head in which a coil is provided between the lower magnetic core and the upper magnetic core; A thin film magnetic head having a heater provided in the vicinity of the read head, and a resistance wire constituting the heater is at least one metal thin film selected from the group consisting of NiCr, Nb, Ta, Ti and W And a high melting point metal thin film provided above and below the metal thin film.

  The thin film magnetic head of the present invention is a recording head in which a magnetoresistive effect element is provided between the lower magnetic shield layer and the upper magnetic shield layer, and a coil is provided between the lower magnetic core and the upper magnetic core. In a thin film magnetic head having a head and a heater provided in the vicinity of the reproducing head, a nonmagnetic metal layer is provided above the heater and in the vicinity of the lower magnetic shield layer.

  Furthermore, the thin film magnetic head of the present invention is a recording head in which a magnetoresistive effect element is provided between the lower magnetic shield layer and the upper magnetic shield layer, and a coil is provided between the lower magnetic core and the upper magnetic core. In a thin film magnetic head having a head and a heater provided in the vicinity of the reproducing head, the heater has a resistance wire patterned in a U-shape, and the corner portion of the resistance wire has a higher melting point than the resistance wire. The resistance wire corners are arc-shaped, or the cross pattern portion connecting the resistance wire corners is made of a metal thin film having a higher melting point than the resistance wires. It is what.

  According to the present invention, since the resistance to electromigration of the heater resistance wire can be improved, a thin film magnetic film having a heater having a sufficient margin with respect to the energization amount is optimal for high-density magnetic recording / reproduction. A head can be provided.

  With reference to FIG. 8 and FIG. 9, a schematic configuration of a magnetic disk device and a thin film magnetic head related to the present invention will be described. FIG. 8 is a top view showing the overall configuration of the magnetic disk device, and FIG. 9 is a perspective view of the thin film magnetic head as seen from the air bearing surface side. The magnetic disk device 100 includes a magnetic disk 104 rotated by a spindle motor 102, a thin film magnetic head 1 on which a reproducing head and a recording head are mounted, a suspension 106 that supports the thin film magnetic head 1, and an actuator 110 that rotates the suspension 106. And a ramp mechanism 112 for retracting the thin film magnetic head 1. The thin film magnetic head 1 is supported by a suspension 106, floats on a rotating magnetic disk, and reads / writes magnetic information recorded on the magnetic disk. The actuator 110 is constituted by a voice coil motor. When the recording / reproducing operation of the thin film magnetic head 1 is completed or when the magnetic disk device 100 is stopped, the thin film magnetic head 1 is connected to the ramp mechanism 112 via the lift tab 108 at the tip of the suspension. Evacuate.

  Referring to FIG. 9, the thin film magnetic head 1 has a slider (substrate) 2 and an element portion 15, and a head element portion 16 in which a reproducing head and a recording head are stacked is formed on the element portion 15. A flying rail 17, a shallow groove rail 18, and a deep groove 19 are formed on the flying surface of the slider 2 facing the magnetic disk. FIG. 10A shows a state in which the thin film magnetic head 1 is flying above the magnetic disk 104. The thin film magnetic head 1 rides on a viscous laminar flow generated by the rotation of the magnetic disk 104 in the direction of the arrow, and floats by lifting the air inflow end side from the air outflow end side (head element unit 16 side). The distance from the surface of the magnetic disk 104 to the head element unit 16 is defined as the flying height h of the thin film magnetic head 1.

  1 is a diagram showing a configuration of a head element portion of a thin film magnetic head according to Embodiment 1 of the present invention, and is a cross-sectional view taken along line AA of FIG. In the thin film magnetic head 1 according to the present embodiment, a heater 4 for adjusting the flying height between the head and the medium is formed in a predetermined shape on the substrate (slider) 2 via the alumina insulating layer 3. A magnetoresistive effect element portion 7 and an upper magnetic shield layer 8 are formed in the lower magnetic shield layer 5, the alumina insulating layer 6, and the alumina insulating layer 6 constituting the reproducing head, and the alumina insulating layer 6 ′ is interposed therebetween. The lower magnetic core 9, the coil 10, the upper pole 11, and the upper magnetic core 12 constituting the recording head are formed, and the protective insulating layer 13 is formed thereon.

  FIG. 2 is an enlarged view of the magnetoresistive effect element portion 7 as viewed from the air bearing surface side, and shows a layer structure of a GMR (Giant Magnetoresistine) element. In the magnetoresistive effect element portion 7, an antiferromagnetic layer 71 is formed on an insulating layer (not shown), followed by a ferromagnetic fixed layer 72, a nonmagnetic conductive layer 73 such as Cu, and a ferromagnetic free layer 74. Is a multilayer film laminated. A magnetic domain control layer 75 and an electrode layer 76 are disposed on both ends of the multilayer film. The magnetization direction of the fixed layer 72 is fixed by an exchange coupling magnetic field generated at the interface with the antiferromagnetic layer 71. On the other hand, the magnetization direction of the free layer 74 can be changed according to the direction of the external magnetic field. The magnetic disk device reproduces information on the magnetic disk by utilizing the characteristic that the resistance of the GMR element 7 changes depending on the angle formed by the fixed layer 72 and the free layer 74. Specifically, when the magnetization direction of the fixed layer 72 and the magnetization direction of the free layer 74 are parallel, the resistance of the GMR element 7 is minimum, and when it is antiparallel, the resistance of the GMR element 7 is maximum.

  FIG. 3 shows a planar shape of the heater 4. The heater 4 has a structure in which a resistance wire 40 meanders, and has lead wires 43 and 44 for supplying current at both ends thereof. 4A and 4B are sectional views showing the configuration of the resistance wire 40. FIG. The resistance wire 40 shown in FIG. 4A is composed of a laminated film of a NiCr thin film 41 and a Ta thin film 42. The feature of this configuration is that the Ta thin film 42 is disposed in the upper layer and the lower layer of the NiCr thin film 41 and is formed so as to sandwich the NiCr thin film 41 therebetween. When comparing the current resistance of Ta and NiCr, so-called electromigration resistance, Ta, which is a refractory metal, is significantly superior. By adopting a structure in which the NiCr thin film is sandwiched between such Ta thin films, the resistance wire Electromigration resistance will be greatly improved. Further, by sandwiching the NiCr thin film 41 with the Ta thin film 42, the interface between the NiCr thin film and the insulating layer, which is the origin of electromigration of the NiCr thin film 41, is eliminated, and the electromigration resistance of the NiCr thin film itself is improved. Can do. The resistance wire 40 shown in FIG. 4B is obtained by forming a NiCr thin film 41 into a multilayer and disposing Ta thin films 42 above and below each NiCr thin film 41. Also in this case, since each NiCr thin film 41 is sandwiched by the Ta thin film 42, the resistance resistance and the electromigration resistance of the NiCr thin film are greatly improved.

  The thin-film magnetic head 1 shown in FIG. 1 on which the heater 4 having excellent electromigration resistance shown in FIGS. 4A and 4B is mounted has a small resistance change of the resistance wire 40, and therefore a predetermined amount of heat generation can be obtained with respect to the energization amount. It is done. Therefore, the flying height control of the thin film magnetic head 1 using the heater 4 can be accurately performed. Moreover, since it can be used stably with the planned calorific value, the energization life of the heater 4 can be extended. Furthermore, since the deterioration due to electromigration is small, disconnection of the resistance wire 40 can be prevented.

  Here, the flying height control of the thin film magnetic head 1 will be described with reference to FIGS. 10A and 10B. FIG. 10A shows a case where the heater 4 is not energized, and FIG. 10B shows a case where the heater 4 is energized. In the heater 4 of the thin film magnetic head 1, since the resistance wire 40 does not cause electromigration, the resistance value of the resistance wire 40 maintains a predetermined value, and a predetermined heat generation amount is obtained with respect to the energization amount. Accordingly, as shown in FIG. 10B, the protrusion amount p of the head element portion 16 can be accurately controlled. Therefore, the flying height h of the thin film magnetic head 1 shown in FIG. 10A is reduced by the protrusion amount p. It can be accurately controlled.

  As described above, since the heater structure according to the first embodiment is used, in order to adjust and control the optimum flying height for each head, it is reliable for the optimum energization amount set to the heater. Therefore, it is possible to realize a heater having a sufficient current resistance margin, and to obtain a thin film magnetic head that is optimal for high-density magnetic recording / reproduction.

  In Example 1, the NiCr thin film and the Ta thin film were used as the heater material. However, instead of the NiCr thin film, a refractory metal thin film such as Ta, Ti, Nb, or W or other transition metal thin film can be used. . Further, in place of the Ta thin film 42, a refractory metal thin film of Ti, Nb, W or the like can be used.

  FIG. 5 is a sectional view of the head element portion of the thin film magnetic head according to the second embodiment. The thin-film magnetic head 1 'shown in FIG. 5 is close to the lower magnetic shield layer 5 so as to cover the upper portion of the heater 4 as shown in the figure with respect to the heater 4 installed at the rear of the lower magnetic shield layer 5. Thus, a nonmagnetic metal layer 46 made of Cu is laminated. Other configurations are the same as those in the first embodiment. By covering the entire heater 4 with the nonmagnetic metal layer 46 made of Cu and forming the nonmagnetic metal layer 46 so as to be close to the lower magnetic shield layer 5, the heat generated by the heater 4 is efficiently reduced. Since it can escape to the lower magnetic shield layer 5 side through the magnetic metal layer 46, it has the effect of efficiently projecting the air bearing surface, and at the same time, the temperature rise of the heater 4 itself is mitigated. Resistance is greatly improved.

  Even with the heater configuration according to the second embodiment, a heater having a sufficient withstand current margin can be realized with respect to the optimum heater energization amount set for each head. A thin film magnetic head optimal for high-density magnetic recording / reproduction can be provided.

  In Example 2, a Cu layer was used as the nonmagnetic metal layer 43 covering the heater 4. However, instead of this, another metal material that is nonmagnetic and has good thermal conductivity can be used. Further, there is no particular problem even if the nonmagnetic metal layer 43 is provided so as to be in contact with the lower magnetic shield layer 5, and the efficiency of the protrusion of the air bearing surface due to the heat generated by the heater 4 is rather improved.

  Next, the heater configuration of the thin film magnetic head according to the third embodiment will be described with reference to FIGS. 6A to 6D. FIG. 6A shows a basic configuration of the heater 4. The heater 4 is obtained by patterning a resistance wire 40 of a NiCr thin film into a U-shape. FIG. 6B shows a specific configuration example. This example is characterized in that a metal film different from the NiCr thin film, for example, a Ta thin film 40b, is stacked at the corner 40a of the resistance wire 40 of the U-shaped NiCr thin film. That is. With this configuration, electromigration caused by a current concentrated on the corner portion 40a is suppressed, so that the electromigration resistance of the resistance wire itself can be greatly improved.

  FIG. 6C shows another configuration example. The feature of this configuration is that the corner portion 40a of the resistance wire 40 of the U-shaped NiCr thin film has an arc shape 40c or a chamfered shape 40d. Also with this configuration, electromigration caused by the current concentrated on the corner portion 40a is suppressed, so that the electromigration resistance of the resistance wire itself can be greatly improved.

  FIG. 6D shows still another configuration example. The feature of this configuration is that a pattern 40e of the U-shaped resistance wire 40 extending in the head element height direction is formed of a NiCr thin film, and an end portion of this pattern is formed. The cross pattern 40f that connects the two is formed of a metal film different from the NiCr thin film, for example, a Ta thin film. Also with this configuration, electromigration caused by the current concentrated on the corner 40a of the U-shaped pattern is suppressed, so that the electromigration resistance of the resistance wire itself can be greatly improved.

  Further, in the patterned heater 4 shown in FIGS. 6B, 6C, and 6D, as shown in FIG. 6A, the interval b between the patterns of the resistance lines 40 is set to be not less than 1 times the pattern width a. The heater resistance can be controlled from 100Ω to 1000Ω by forming the length pattern C so that the ratio C / D of the length C and D of the line patterns intersecting each other is within 1-2. This has the effect of alleviating the temperature rise due to the concentration of heat generated by the heater itself, and this can also improve the resistance to electromigration of the resistance wire.

  By the way, in order to control the flying height to the optimum value by projecting the floating surface by the heat generation of the heater 4, when the thin film magnetic head 1 is mounted on the magnetic recording device, the flying height when the heater 4 is not energized is set. On the other hand, a protrusion of about 2 to 10 nm is necessary by energization. For this purpose, the protrusion sensitivity of the air bearing surface in the magnetoresistive effect element portion 7 with respect to the electric power applied to the heater 4 is designed to be about 1-2 nm / 10 mW. Is desirable. FIG. 7 shows the resistance due to self-heating of the heater 4 in Example 3 when the resistance line pattern width a is 2 μm, the resistance of the heater 4 is designed to be 500Ω, and the protrusion sensitivity of the air bearing surface is about 1 nm / 10 mW. The relationship between the ratio b / a of the resistance line pattern interval b to the pattern width a with respect to the rate of change and the ratio C / D of the lengths of the line patterns is shown. From the figure, the resistance change rate decreases as b / a increases and C / D approaches 1. That is, it can be seen that there is an effect that the temperature rise of the heater 4 can be suppressed while keeping the protrusion sensitivity of the air bearing surface constant. This effect improves the electromigration resistance of the resistance wire itself as described above. In this embodiment, the resistance line pattern width a is set to 2 μm, but the pattern width a is preferably designed in the range of 0.5 to 5 μm.

  As described above, according to the present invention, it is possible to greatly improve the electromigration resistance of the heater, and therefore, with respect to the optimum heater energization amount set for each thin film magnetic head using the heater. Thus, a heater having a sufficient current withstanding margin can be realized, and a thin film magnetic head optimal for high-density magnetic recording / reproduction can be provided.

It is sectional drawing of the head element part of the thin film magnetic head by Example 1 of this invention. It is the enlarged view which looked at the magnetoresistive effect element part of FIG. 1 from the air bearing surface. It is a top view which shows the shape of the heater of FIG. FIG. 3 is a cross-sectional view showing a resistance wire of a heater in Example 1. 6 is a cross-sectional view showing another example of a resistance wire of a heater in Embodiment 1. FIG. It is sectional drawing of the head element part of the thin film magnetic head by Example 2 of this invention. It is a top view which shows the basic composition of a heater of the thin film magnetic head by Example 3 of this invention. It is a top view which shows the specific structure of a heater of the thin film magnetic head by Example 3 of this invention. It is a top view which shows the other example of the specific structure of a heater of the thin film magnetic head by Example 3 of this invention. It is a top view which shows the further another example of the specific structure of a heater of the thin film magnetic head by Example 3 of this invention. It is a figure which shows the relationship of the ratio b / a of the resistance line pattern space | interval b and the pattern width a with respect to the resistance change rate by self-heating of the heater in Example 3, and ratio C / D of the length of line patterns. It is a top view which shows the whole structure of the magnetic disc apparatus relevant to this invention. It is the perspective view seen from the air bearing surface side of the thin film magnetic head relevant to this invention. It is a side view which shows a mode that the thin film magnetic head has floated on the magnetic disk. It is a side view which shows a mode that the flying height of a thin film magnetic head is controlled by supplying with electricity to a heater.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1 '... Thin-film magnetic head, 2 ... Substrate (slider), 3, 6, 6' ...: Alumina insulating layer, 4 ... Heater, 5 ... Lower magnetic shield layer, 7 ... Magnetoresistive element part, 8 ... Upper Magnetic shield layer, 9 ... Lower magnetic core, 10 ... Coil, 11 ... Upper pole, 12 ... Upper magnetic core, 13 ... Protective insulating layer, 15 ... Element part, 16 ... Head element part, 17 ... Floating rail, 18 ... Shallow Groove rail, 19 ... deep groove, 40 ... resistance wire, 40a ... corner, 40b, 40f ... Ta thin film, 40e ... resistance wire pattern, 40f ... cross pattern, 41 ... NiCr thin film, 42 ... Ta thin film, 43, 44 ... lead Reference numeral 46: Nonmagnetic metal layer 100: Magnetic disk device 102: Spindle motor 104: Magnetic disk 106: Suspension 108: Lift tab 110: Actuator 112: Ramp mechanism

Claims (16)

  A reproducing head in which a magnetoresistive element is provided between the lower magnetic shield layer and the upper magnetic shield layer, a recording head in which a coil is provided between the lower magnetic core and the upper magnetic core, and provided in the vicinity of the reproducing head In the thin film magnetic head having the heater, at least one metal thin film selected from the group consisting of NiCr, Nb, Ta, Ti and W, the resistance wire constituting the heater, and the upper and lower sides of the metal thin film A thin-film magnetic head comprising a high-melting-point metal thin film provided on the head.   2. The thin film magnetic head according to claim 1, wherein the high melting point metal thin film is made of at least one metal selected from the group consisting of Ta, Nb, Ti and W.   2. The thin film magnetic head according to claim 1, wherein the metal thin film is a NiCr film, and the high melting point metal thin film is a Ta film.   The resistance wire of the heater has two or more thin films of at least one metal selected from the group consisting of NiCr, Nb, Ta, Ti and W, and is provided above and below each of the two or more metal thin films. 2. The thin film magnetic head according to claim 1, further comprising a thin metal film having a high melting point.   5. The thin film magnetic head according to claim 4, wherein the high melting point metal thin film is made of at least one metal selected from the group consisting of Ta, Nb, Ti and W.   5. The thin film magnetic head according to claim 4, wherein the metal thin film is a NiCr film, and the high melting point metal thin film is a Ta film.   A reproducing head in which a magnetoresistive element is provided between the lower magnetic shield layer and the upper magnetic shield layer, a recording head in which a coil is provided between the lower magnetic core and the upper magnetic core, and provided in the vicinity of the reproducing head A thin film magnetic head having a heater, wherein a nonmagnetic metal layer is provided in the vicinity of the lower magnetic shield layer above the heater.   The resistance wire of the heater is composed of a thin film of at least one metal selected from the group consisting of NiCr, Nb, Ta, Ti and W, and the nonmagnetic metal layer is composed of Cu. The thin film magnetic head according to claim 7.   8. The thin film magnetic head according to claim 7, wherein the nonmagnetic metal layer is provided at a rear portion of the lower magnetic shield layer.   8. The thin film magnetic head according to claim 7, wherein the nonmagnetic metal layer is provided in contact with a rear portion of the lower magnetic shield layer.   A reproducing head in which a magnetoresistive element is provided between the lower magnetic shield layer and the upper magnetic shield layer, a recording head in which a coil is provided between the lower magnetic core and the upper magnetic core, and provided in the vicinity of the reproducing head In the thin film magnetic head having a heater, the heater has a resistance wire patterned in a U shape, and a corner portion of the resistance wire is covered with a metal thin film having a higher melting point than the resistance wire. Or the corners of the resistance wire are arcuate, or the cross pattern portion connecting the corners of the resistance wire is made of a metal thin film having a melting point higher than that of the resistance wire. Thin film magnetic head.   The resistance wire is a NiCr film, and when a corner portion of the resistance wire is covered with a metal thin film having a higher melting point than the resistance wire, the high melting point metal thin film is a Ta film. 11. The thin film magnetic head according to 11.   When the pattern width of the resistance line is a and the pattern interval is b, b / a is 1 or more, the length of the resistance line in the element height direction is C, and the length of the cross pattern is D. 13. The thin film magnetic head according to claim 12, wherein C / D is 1 to 2.   When the resistance wire is a NiCr film and the cross pattern portion connecting the corners of the resistance wire is composed of a metal thin film having a higher melting point than the resistance wire, the high melting point metal thin film is a Ta film. The thin film magnetic head according to claim 11.   When the pattern width of the resistance line is a and the pattern interval is b, b / a is 1 or more, the length of the resistance line in the element height direction is C, and the length of the cross pattern is D. 15. The thin film magnetic head according to claim 14, wherein C / D is 1 to 2.   When the corner portion of the resistance wire has an arc shape, the pattern width of the resistance wire is a, and the pattern interval is b, b / a is 1 or more, and the element height direction of the resistance wire 16. The thin film magnetic head according to claim 15, wherein C / D is 1 to 2 where C is the pattern length and D is the cross pattern length.

Images