JP4492418B2 - Thin film magnetic head and manufacturing method thereof - Google Patents

Description

  The present invention relates to a thin film magnetic head used in a helical tape scanning system or the like compatible with high density recording, and a manufacturing method thereof.

  A magnetic recording / reproducing apparatus equipped with a magnetic head can be used as a camera-integrated video recorder using the helical tape scanning system shown in FIG. 31, a data storage tape streamer, a tape streamer using a linear tape system, and a hard disk drive. Many products have been put to practical use in response to this.

  In recent years, the total amount of information being handled has increased dramatically due to the high definition of video, image and audio information. There are a hard disk drive, an optical disk system, and a magnetic tape recording system as a method for storing such information, and an archival or the like often uses a magnetic tape system that can store a large amount of information at low cost and at high speed. In order to store information at a lower cost and at a higher speed with this magnetic tape recording system, it is necessary to shorten the recording pitch in the tape running direction (track direction) and the interval between the tracks (track pitch) to improve the surface recording density. Has been.

  A helical tape scanning system shown in FIG. 31, that is, a magnetic recording / reproducing apparatus 1, includes a rotating drum 3 on which a thin film magnetic head 2 for recording and reproducing information on a magnetic tape is mounted. The information is recorded and reproduced by being inclined with respect to the circumferential direction of the rotating drum 3 that is traveling. That is, in the magnetic recording / reproducing apparatus 1, the rotary drum 3 is configured to have a pair of upper drum 5 and lower drum 6 disposed with a required gap therebetween, and the magnetic head 2 rotates integrally with the upper drum 5, for example. Arranged to drive. The thin film magnetic head 2 is composed of two thin film magnetic heads 2 [2A, 2B] arranged at an interval of about 180 °. The two magnetic heads 2A and 2B are formed such that the recording gaps g1 and g2 are inclined at angles of about θ and −θ, respectively, with respect to the tape running direction. FIG. 32 shows one thin film magnetic head 2. The thin film magnetic head 2 is arranged such that a head element having a pair of thin film magnetic cores 8 and a coil conductor 9 is sandwiched between non-magnetic blocks 11 having a tape sliding surface 10, and the recording cap g is It is formed at an angle of θ with respect to the running direction D of the magnetic tape.

  FIG. 33 schematically shows a conventional inductive thin film magnetic head 2. The thin film magnetic head 2 includes a lower magnetic core 8A and an upper magnetic core 8B that form a recording gap g on a nonmagnetic substrate 7, and a coil conductor 9 that wraps the magnetic core 8 between the lower and upper magnetic cores 8A and 8B. And are constructed.

  In this helical tape scanning system, the magnetic recording pattern on the magnetic tape 4 is recorded at an angle of θ or −θ with respect to the tape running direction, and as shown in FIG. Using the so-called azimuth recording technique having the relationship, the information on the adjacent tracks is masked, and the track information is read stably.

  As another example of the thin film magnetic head, as shown in FIG. 35, a thin film magnetic head constructed by making the width of the lower magnetic core 8A larger than the width of the tip magnetic pole end of the upper magnetic core 8B (corresponding to the track width Tw). 2 is also known.

On the other hand, as a single magnetic pole head for perpendicular magnetic recording used for a magnetic disk, in order to prevent the recording magnetic field from decreasing at the track edge, the first portion of the two portions constituting the main magnetic pole has a width of A single magnetic pole head for perpendicular magnetic recording has been proposed in which the left and right sides are symmetrically and obliquely cut so as to continuously increase from the leading side to the trailing side in the moving direction of the magnetic disk (see Patent Document 1). .
JP 2003-242607 A

  In general, as shown in FIG. 34, a region 14 having a disordered magnetization pattern called a side erase exists between the recording tracks 12. This is caused by the influence of magnetic flux emitted from the end of the recording gap g of the magnetic core 2 and the side surface of the magnetic core 2 in the direction other than the track direction as shown in FIG. In addition, when writing magnetization information to a vapor-deposited recording medium suitable for high-density recording with a helical tape scanning system, as shown in FIG. 37, the easy magnetization domain of the magnetic tape moves in the relative scanning direction of the magnetic tape and the magnetic head. As a result, the magnetic field strength M in the magnetic tape easy axis direction from the trailing side in the head traveling direction (relatively traveling direction on the recording medium, that is, the traveling direction on the magnetic tape) is the recording level. Dominated. In FIG. 37, 2 is a recording magnetic core comprising magnetic cores 8A and 8B with a recording gap g interposed therebetween, M is a head magnetic field that contributes to recording, 4 is a vapor-deposited magnetic tape, 4A is a magnetization region, and 4B is a magnetization transition region. Indicates. That is, as shown in the schematic diagram of the magnetic head 2 in FIG. 35, the width of the upper magnetic core 8B is narrower than the lower magnetic core 8A, the magnetic flux density on the upper magnetic core 8B side is increased, and the upper magnetic core 8B is advanced. The higher the recording level.

  Therefore, if the magnetic core shape of the conventional thin film magnetic head 2 as shown in FIGS. 33 and 35, particularly the tape contact surface of the upper magnetic core 8B is square, the head running direction (relative to the magnetic gap on the trailing side) The magnetic field from the side surface of the magnetic core that is inclined toward the leading side of the magnetic tape (running direction on the magnetic tape) causes particularly remarkable side erasure. When the track pitch is shortened in order to improve the surface recording density in such a state where there are many side erased areas, the side erased area is more relative to the data area on the tape surface than the state where the surface recording density is low. There are many. If the track pitch is shortened by ignoring the side erase, the track on which the information is originally recorded disappears, and the magnetic recording / reproducing system using the reproducing head using the magnetoresistive effect having high magnetic field sensitivity does not function.

  In view of the above, the present invention provides a thin film magnetic head capable of reducing or eliminating recording pattern disturbance (so-called side erase) of adjacent tracks and a method of manufacturing the same.

A thin film magnetic head according to the present invention is a helical tape scanning thin film magnetic head for azimuth recording, and the width of the magnetic pole end and the width of the magnetic pole end gradually increase from the magnetic pole end behind the depth zero line. And a lower magnetic core, and a recording gap formed between the magnetic pole end of the upper magnetic core and the lower magnetic core. The upper magnetic core is disposed on the leading side in the head running direction, which is the track scanning direction to the magnetic recording medium, with respect to the lower magnetic core, and one side of the magnetic pole end of the upper magnetic core is at least an azimuth angle from the recording gap. The range of the diagonal cut from the depth zero line at the magnetic pole end portion of the upper magnetic core to the wide portion does not exceed 2 × t1 μm with the thickness of the upper magnetic core t1 (including 0) Z)) .

According to the present invention, in the above thin film magnetic head, one side of the magnetic pole end of the lower magnetic core is obliquely cut in the same manner as one side of the magnetic pole end of the upper magnetic core.
The thin film magnetic head according to the present invention has a configuration in which one side of the magnetic pole end is removed to the entire thickness of the upper magnetic core and to half or less of the thickness of the lower magnetic core.

A method of manufacturing a thin film magnetic head according to the present invention is a method of manufacturing a helical tape can thin film magnetic head for azimuth recording, and an insulating film is formed on a substrate on which a depth polishing sensor using a resistance sensor is formed. And forming a lower magnetic core comprising a magnetic pole tip and a wide portion gradually wider than the magnetic pole tip behind the depth zero line and having a constant width in the middle, and recording to cover the lower magnetic core A step of forming a gap film. Next, a step of forming a thin film coil on the recording gap film, a step of forming an upper core planarizing film by an insulating film on the surface corresponding to the lower magnetic core and the thin film coil, and a magnetic pole end on the upper core planarizing film And a step of forming an upper magnetic core comprising a wide portion having a width that gradually increases from the end of the magnetic pole and is constant from the middle after the depth zero line. Next, the entire surface including the upper magnetic core has a trimming opening for inclining one side of the magnetic pole end of the coarse upper magnetic core, and the inner surface of the opening is inclined at an azimuth angle or more, Forming a resist mask that is located at a position shifted in the track width direction by a required distance from the magnetic pole end of the lower magnetic core so that the opening has the track width of the magnetic pole end of the upper magnetic core after etching. Next, one side of the magnetic pole end portion of the upper magnetic core is etched away obliquely so as to be equal to or larger than the azimuth angle from the recording gap along the inclined surface of the opening of the resist mask, and in this etching, the magnetic pole end of the upper magnetic core is removed. Etching to form the upper magnetic core so that the range of diagonal cuts from the depth zero line of the portion to the wide portion does not exceed 2 × t1 μm (excluding 0), where the thickness of the upper magnetic core is t1 Process. Further, the method includes a step of forming a planarization insulating film on the entire surface and a step of obtaining a predetermined magnetic gap depth by using a depth polishing sensor after being divided into thin film head chips.

In the present invention, in the above etching step, one side of the magnetic pole end of the lower magnetic core is cut obliquely in the same manner as one side of the magnetic pole end of the upper magnetic core.

In the above-described etching step, the present invention can etch up to the entire thickness of the upper magnetic core and half or less of the thickness of the lower magnetic core.
In the present invention, the width of the magnetic pole end of the lower magnetic core before the etching step is preferably set larger than the final magnetic track width.

According to the thin film magnetic head according to the present invention, one side of the magnetic pole end portion of the upper magnetic core disposed on the leading side in the head running direction with respect to the lower magnetic core is cut obliquely so as to have an azimuth angle or more from the recording gap. By configuring as described above, there is no disturbance in the recording pattern of the adjacent track affected by the end of the upper magnetic core. Therefore, even if magnetic recording is performed using a thin film magnetic head, a decrease in output due to pattern disturbance can be prevented, and high-density and stable helical tape scanning azimuth recording is possible.
The upper-layer magnetic core has a range of oblique cuts from the depth zero line at the magnetic pole end portion of the upper-layer magnetic core to the wide-width portion not exceeding 2 × t1 μm (excluding 0), where the thickness of the upper-layer magnetic core is t1. Magnetic saturation near the core depth zero can be relaxed.

  As with one side of the magnetic pole end of the upper magnetic core, even when one side of the magnetic pole end of the lower magnetic core is cut obliquely, the recording pattern disturbance of the adjacent track is eliminated, and a high-density and stable helical tape scanning system is used. Enable azimuth recording. By aligning the inclined track edges of the upper and lower magnetic cores, recording blur due to submicron misalignment of the upper and lower magnetic cores is eliminated, and recording is performed more than when there is a subtle shift of the upper and lower magnetic core track edges. Pattern quality is improved.

According to the method of manufacturing a thin film magnetic head according to the present invention, the lower layer magnetic core, the recording gap film, the coil conductor, and the upper layer magnetic core are sequentially formed, and then one side of the magnetic pole end of the upper layer magnetic core is formed on the resist mask in the etching process. One side of the magnetic pole end portion of the upper magnetic core is etched away at an angle equal to or greater than the azimuth angle from the recording gap so as to follow the inclined surface of the opening. By having this step, it is possible to manufacture a thin film magnetic head capable of high-density and stable helical tape scanning azimuth recording without disturbing the recording pattern of adjacent tracks.
In this etching process, the range of the diagonal cut from the depth zero line at the magnetic pole end of the upper magnetic core to the wide portion does not exceed 2 × t1 μm (however, not including 0), where the thickness of the upper magnetic core is t1. Thus, the above-described thin-film magnetic head in which the magnetic saturation near the depth zero of the upper magnetic core is relaxed can be manufactured.

In the above etching process, as with one side of the magnetic pole end of the upper magnetic core, one side of the magnetic pole end of the lower magnetic core is cut obliquely, thereby eliminating the disturbance of the recording pattern of the adjacent track, high density and stable A thin-film magnetic head that enables azimuth recording by a helical tape scan method can be manufactured. By aligning the inclined track edges of the upper and lower magnetic cores, recording blur due to submicron misalignment of the upper and lower magnetic cores is eliminated, and recording is performed more than when there is a subtle shift of the upper and lower magnetic core track edges. A thin film magnetic head with improved pattern quality can be manufactured.

  In the etching step, the entire thickness of the upper magnetic core and half or less of the thickness of the lower magnetic core can be etched. In this case, by setting the width of the magnetic pole end of the lower magnetic core before the etching step to be larger than the final magnetic track width, etching removal on one side of the magnetic pole end of the lower magnetic core can be performed satisfactorily. it can.

  Embodiments of the present invention will be described below with reference to the drawings.

  An embodiment of a thin film magnetic head according to the present invention is a magnetic head used in a helical tape scan type azimuth magnetic recording system, comprising a lower magnetic core thin film, a recording gap thin film, a thin film coil conductor, and an upper magnetic core thin film. The upper magnetic core is provided on the leading side in the head running direction (relatively running direction on the magnetic recording medium, that is, running direction on the magnetic tape). The upper magnetic core thin film is formed on the magnetic recording pattern in which the tip magnetic pole end of the upper magnetic core is inclined more than the azimuth angle and the trajectory drawn on the magnetic tape of the recording gap, that is, the azimuth angle adjacent to the outside of the magnetic recording pattern is different. The tip magnetic pole end of the upper magnetic core thin film is formed in a shape that is obliquely cut so that only one side thereof has an azimuth angle or more from the recording gap.

  With this configuration, when the thin film magnetic head is moved relative to the magnetic tape, the tip magnetic pole end of the upper magnetic core thin film does not cross the guard band and straddle the adjacent track, and other than the recording gap. The magnetic flux leakage portion can be eliminated, and the side erase area is reduced.

  1 to 3 show an example of an embodiment of a thin film magnetic head according to the present invention, that is, a thin film magnetic head (recording head) used in a helical tape scan type magnetic recording system. The thin film magnetic head 31 according to the present embodiment includes a lower magnetic core 33 formed of a thin film on a nonmagnetic substrate 32, a recording gap film 34 that forms a recording gap g, a coil conductor 35, and an upper magnetic core 36. The thin film magnetic head element 41 is formed, and only one surface 37 of the tip magnetic pole end portion 36A of the upper magnetic core 36 is obliquely cut.

  The lower magnetic core 33 is composed of a tip magnetic pole end portion 33A and a wide portion 33B which is gradually wider than the tip magnetic pole end portion 33A behind the depth zero line and has a constant width from the middle. The upper magnetic core 36 is composed of a tip magnetic pole end portion 36A and a wide portion 36B having a width that is gradually wider than the tip magnetic pole end portion 33A behind the depth zero line and that is constant from the middle. In the lower magnetic core 33 and the upper magnetic core 36, the tip magnetic pole end 33A and the tip magnetic pole end 36A have the same track width Tw, and the wide portion 33B of the lower magnetic core 33 is the wide portion of the upper magnetic core 36. The lower magnetic core 33 is formed so as to have a larger area than the upper magnetic core 36 in terms of volume.

  Similar to FIG. 15, the thin-film magnetic head element 41 is sandwiched between non-magnetic blocks (some of which also serve as the substrate 32) 43 and 44 through an insulating layer 42 as shown in FIGS. Be placed. In the lower layer of the lower magnetic head core 33 of the thin film magnetic head element 41, a polishable resistance sensor 46 for determining the depth of the thin film magnetic head element is disposed.

  Here, in the tip magnetic pole end portion 36A of the upper magnetic core 36, the width on the side facing the tip magnetic pole end portion 33A of the lower magnetic core 33 across the recording gap film 34 is the track width Tw (see FIGS. 2 and 9B). Thus, a surface 37 inclined at a required angle in the film thickness direction from the width edge of the lower surface of the magnetic pole end portion 36A is formed. The inclined surface 37 of the tip magnetic pole end 36A of the upper magnetic core 36 is formed so as to be parallel to the edge in the width direction of the recording track or to enter the recording track when recording with the thin film magnetic head. (See the example of FIG. 5). In other words, the recording gap g is formed to be equal to or greater than the azimuth angle.

The inclined surface 37 on one side of the tip magnetic pole end portion 36A of the upper magnetic core 36 is formed by an etching process. At this time, the wide magnetic portion 36B side is also etched from the tip magnetic pole end portion 36A. However, the etched range DpT (see FIG. 9A described later) can be within 2 × t1 μm ( not including 0 μm) when the film thickness of the upper magnetic core 36 is t1. When it exceeds 2 × t1 μm, magnetic saturation near the depth zero of the upper magnetic core 36 appears remarkably. In the thin film magnetic head 31, the upper magnetic core 36 is disposed on the leading side in the head running direction (relative to the magnetic tape running direction) with respect to the lower magnetic core 33.

  FIG. 4 shows another schematic example of the thin film magnetic head according to the present invention. This example is a thin film magnetic head device having a pair of thin film head elements having different azimuth angles. The first azimuth head element 51 includes an upper magnetic core disposed on a nonmagnetic substrate 52 with a lower magnetic core 53A and a recording gap g1 interposed therebetween, as shown in FIG. A (cross-sectional view facing the tape sliding surface). 54A. In this case, the width of the lower magnetic core 53A is larger than the width of the recording gap portion of the upper magnetic core 54A, and the track width Tw is determined by the width of the upper magnetic core 54A. Then, one end of the upper magnetic core 54A, that is, the left end face 55 in the figure, is formed so as to be inclined at the required angle described above so that the width of the upper magnetic core 54A becomes narrower from the recording gap g1 in the film thickness direction. .

On the other hand, the second azimuth head element 56 has an upper layer disposed on the nonmagnetic substrate 52 with the lower magnetic core 53B and the recording gap g2 interposed therebetween, as shown in FIG. B (cross-sectional view facing the tape sliding surface). It consists of a magnetic core 54B. In this case, the width of the lower magnetic core 53B is larger than the width of the recording gap portion of the upper magnetic core 54B, and the track width Tw is determined by the width of the upper magnetic core 54B. Then, one side of the upper magnetic core 54B, which is opposite to the end surface 55 of the upper magnetic core 54A of the first azimuth head element 51 in the drawing, is arranged so that the width of the upper magnetic core 54B becomes narrower in the film thickness direction from the recording gap g2. The left end face 57 that is the side is formed to be inclined at the required angle described above. The first and second azimuth head elements 51 and 56 are configured such that the recording gaps g1 and g2 have different azimuth angles (see FIG. 5 ).

  Next, a recording pattern (so-called recording track) recorded by the thin film magnetic head for azimuth recording shown in FIG. 4 will be described with reference to FIG. The recording pattern 61 is recorded by the first azimuth head element 51. At this time, the inclined end surface 55 on one side of the upper magnetic core 54A runs along the edge in the width direction of the recording pattern 61 and is adjacent to the recording pattern 61. It does not enter the recording pattern 62 adjacent to the pattern 62 beyond the guard band 63. The recording pattern 62 is recorded by the second azimuth head element 56. At this time, the inclined end surface 57 on one side of the upper magnetic core 54B runs along the edge in the width direction of the recording pattern 62 and is adjacent to the recording pattern 62. The recording pattern 61 adjacent to the recording pattern 61 does not enter the adjacent recording pattern 61 beyond the guard band 63. Therefore, the mutual recording patterns 61 and 62 are not affected by the leakage magnetic flux from the end portions of the upper magnetic cores 54B and 54A of the respective azimuth head elements 56 and 51, and the recording patterns 61 and 62 recorded on the magnetic tape are recorded. In 62, a region having a disordered magnetization pattern called “dyed erase” is not formed.

  The recording pattern is formed in the same manner in the azimuth recording thin film magnetic head 31 having the configuration shown in FIG.

  Therefore, according to the thin film magnetic head according to the present embodiment, even if magnetic recording is performed on the magnetic tape, it is possible to prevent a decrease in output due to the disturbance of the recording pattern, and a high density and stable helical tape scan system. It becomes possible to build.

  Next, a first embodiment of a thin film magnetic head according to the present invention will be described together with a manufacturing method thereof with reference to FIGS. 14 to 30 and FIGS. Note that thin film processing in this embodiment mode uses a photolithography technique, and after forming a photoresist into a predetermined shape, the thin film is formed using the photoresist shape.

First, as shown in FIG. 14, a substrate 101 having a predetermined size for preparing a thin film magnetic head is prepared. A nonmagnetic substrate or a magnetic substrate 101 is typically provided with a diameter of 100 mm and a thickness of 2 mm.
Next, as shown in FIG. 15, the surface of the substrate 101 is polished smoothly, and an insulating film, in this example, an alumina film 102 is sputtered on the polished surface of the substrate 101 to a thickness of about 0.5 μm. Form a film.

  Next, as shown in FIG. 16, on the alumina film 102 of the substrate 101, a metal film such as Ti having a thickness of about 100 nm is used as a resistance sensor for determining the depth of the thin film magnetic head by means of a tape with abrasive grains. A resistor 103 made of a metal film is formed by forming a thick film and etching with a photoresist formed into a predetermined shape. Depth conductors 104 [104A, 104B] connected to both ends of the resistor 103 are formed by electroplating to form a depth polishing sensor 105 using a resistance sensor.

  Next, as shown in FIG. 17, on the surface of the substrate 101 on which the depth polishing sensor 105 is formed, an insulating film having a required thickness so as to cover the depth polishing sensor 105, in this example, the alumina film 106 is about 500 nm. The film is formed to a thickness of. Thereafter, a plating base film 111 for forming a lower magnetic core on the surface of the alumina film 106 by electroplating is formed with a film thickness of about 100 nm, for example.

  Next, as shown in FIG. 18, a plating frame 107 for forming a lower magnetic core by electrolytic plating is formed at a predetermined position on the plating base film 111 of the substrate 101. The plating frame 107 is formed using a photoresist in the shape of the lower magnetic core so that the magnetic pole width exposed on the sliding surface of the lower magnetic core becomes a predetermined track width Tw.

  Next, a ferromagnetic thin film is formed on the entire surface of the substrate including the inside and outside of the plating frame 107 by electrolytic plating. Thereafter, as shown in FIG. 19, the ferromagnetic thin film 109 ′ outside the other plating frame 107 is selectively removed while leaving the ferromagnetic thin film 109 ′ inside the plating frame 107.

  Next, as shown in FIG. 20, the plating frame 107 is removed, and the exposed plating base film 111 is etched away using the remaining ferromagnetic thin film 109 ′ as a mask to form a lower magnetic core 109. At this time, a part of the lower magnetic core 109 becomes connection portions 112A and 112B of the lead conductor of the thin film coil to be formed later.

  Next, as shown in FIG. 21, a recording gap film 110 made of alumina or the like is formed so as to cover the lower magnetic core 109. In this example, the recording gap 110 is formed by forming an alumina film having a thickness of about 200 nm by sputtering or the like.

  Next, as shown in FIG. 22, a part of the alumina film 110 serving as a recording gap is patterned by etching to form openings 113A and 113B in which some connection portions 112A and 112B of the lower magnetic core 109 are exposed. . Thereafter, the surface of the recording gap film 110 is polished and flattened so that the recording gap film 110 has a predetermined thickness, for example, about 180 nm.

  Next, as shown in FIG. 23, a thin film coil 114 that performs electromagnetic conversion is formed on the surface of the substrate. That is, for example, a Cu plating base film (not shown) is formed on the recording gap film 110 with a film thickness of about 100 nm, and then electrolytically plated through a photoresist mask with a film thickness of 3 μm so as to have an opening in a coil shape. A Cu film having a thickness of 2.7 μm is formed. Thereafter, the photoresist mask is removed, and the plating base film is removed by, for example, ion milling to form a thin film coil 114 made of a Cu film. At this time, a part of the thin film coil 114 is connected to the connection portions 112A and 112B on the lower magnetic core 109 side through the openings 113A and 113B. The current path of the thin film coil is as follows: thin film coil 114 (straight) -opening 113A-lower magnetic core 109-opening 113B-thin film coil 114 (spiral). The lower magnetic core 109 becomes a part of the current path, and the contact between the thin film coil 114 and the lower magnetic core 109 becomes the openings 113A and 13B.

  Next, as shown in FIG. 24, an upper core planarizing film 115 made of an insulating film for forming the upper magnetic core is formed on the surfaces corresponding to the lower magnetic core 109 and the thin film coil 114. The upper core planarizing film 115 is a base film for planarizing the upper magnetic core formed on the thin film coil 114, and is a film for insulating the thin film coil 114 from the upper magnetic core. The upper core planarizing film 115 is formed by applying a photoresist having a thickness of, for example, 4 μm on the thin film coil 114 so as to be equal to or greater than the thickness of the thin film coil 114 and thermally curing.

Next, a plating base film for forming the rough upper magnetic core by electrolytic plating is formed by sputtering, for example.
Next, as shown in FIG. 25, a plating frame 117 for forming a coarse upper magnetic core shape is formed. The plating frame 117 is formed so that the width of the portion corresponding to the tip magnetic pole end of the upper magnetic core is larger than the width of the magnetic pole tip that is the same as the track width on the tip of the lower magnetic core 109. In other words, the upper magnetic core is trimmed by etching only on one side after being formed into a rough shape, so that the width of the portion corresponding to the magnetic pole end at the tip of the upper magnetic core of the plating frame 117 is a required width from the track width Tw. Only the RPW is formed (see FIGS. 6 and 9A and B). The plating frame 117 is formed of, for example, a photoresist having a film thickness of 4 μm, similarly to the plating frame 107 for forming the lower magnetic core described above. However, the width RPW is smaller than the width of a trimming mask opening to be described later, more specifically, the distance Df2 (see FIG. 8A) between one edge of the track width Tw and the far end edge of the mask opening.

  Next, as shown in FIG. 26, the upper magnetic core 118 restricted by the plating frame 117 is formed. That is, an upper magnetic core thin film 118 [118A, 118B] having a required film thickness, for example, 3.5 μm, is formed on the plating base film having the plating frame 117 by electrolytic plating (see FIG. 6C), and then the plating frame 117 is formed. The upper magnetic core thin film 118A inside is protected with a photoresist, and the unnecessary upper magnetic core thin film 118B outside the plating frame 117 is etched away. Thereafter, the photoresist is removed, an unnecessary plating base film is removed, and the plating frame 117 is further removed to form the upper magnetic core 118. The upper magnetic core 118 is connected to the lower magnetic core 109 through the opening 113B. By integrating the upper and lower magnetic cores 118 and 109 as magnetic cores, the magnetic field output efficiency can be improved.

  Here, when the area of the magnetic core as viewed from above is viewed, the area of the lower magnetic core 109 is formed larger than the area of the upper magnetic core 118.

  Next, as shown in FIG. 27, a photoresist mask 120 having an opening 119 for trimming one side of the magnetic pole end at the tip of the coarse upper magnetic core 118 in an inclined manner on the entire surface including the upper magnetic core 118. Form. The photoresist mask 120 is such that the inner surface of the opening 119 is such that the magnetic pole end face of the upper magnetic core 118 having a rough shape is inclined at an azimuth angle or more from the normal direction of the substrate (wafer) surface and has a predetermined track width Tw. In consideration of the retraction amount, the lower end of the photoresist mask opening 119 is formed at a position shifted in the track width Tw direction by the distance Df from the magnetic pole end of the lower magnetic core 109 (FIGS. 7A, 7B and 8B). reference). To incline the inner surface 119a of the opening 119, the opening 119 is patterned and then heat-treated.

  Next, one surface of the magnetic pole end portion of the upper magnetic core 118 is aligned with the inclined surface of the opening 119 of the photoresist mask 120 by plasma ion etching using Ar gas or the like through the photoresist mask 120. As shown in FIGS. 28, 9A and 9B, the upper magnetic core 121 having the final shape, that is, the upper magnetic core 121 having the inclined surface 126 on one side of the tip pole end 121A is formed.

By this etching step, the uppermost portion in the thickness direction of the upper magnetic core 121 is etched in the depth depth direction by 0 <DpT ≦ (2 × t1) μm in the depth depth direction (see FIGS. 9A and 9B). Where t1 is the thickness of the upper magnetic core 121. When DpT is etched to exceed 2 × t1 μm, magnetic saturation near the depth zero of the upper magnetic core 121 appears remarkably.

  Next, as shown in FIG. 29, a planarization insulating film such as an alumina film 123 is formed on the entire surface. That is, an alumina film is formed on the substrate to a thickness including the maximum height difference on the substrate and the polishing allowance for flattening polishing. In this example, an alumina film with a film thickness of 30 μm is formed by sputtering, and flattening polishing is performed. Then, a planarized alumina film 123 necessary for attaching the protective substrate is formed.

Next, although not shown, in order to form the external connection terminals of the thin film coil 114 and the depth polishing sensor 105, the planarized alumina film 123 existing at the locations where the external connection terminals of the respective lead conductors are to be formed is removed by etching. To do. Next, in order to form the external connection terminals by plating, a plating base film is formed, and after forming a photoresist into the shape of the external connection terminals, a plating film is formed to a thickness of 100 μm, for example. The thin film magnetic head wafer is formed by removing.

  Next, as shown in FIG. 30, the thin film magnetic head wafer is cut into a predetermined shape to form a thin film magnetic head block 124. Thereafter, the thin film magnetic head block 124 and the substantially substrate are bonded together with an adhesive, and cylindrical polishing is performed so as to follow the shape of the sliding surface, and the thin film head chip is divided. After the division, a thin film head chip is attached to the base plate for mounting on the rotating drum with an adhesive, and tape polishing is performed while measuring the resistance of the resistor 103 so as to obtain a predetermined depth using the depth polishing sensor 105. A thin film magnetic head as shown in FIG.

  Next, a second embodiment of the thin film magnetic head according to the present invention will be described together with its manufacturing method with reference to FIGS. 14 to 30 and FIGS. In this embodiment, the upper magnetic core and the lower magnetic core are simultaneously etched and formed on one side of the tip end portion to obtain a thin film magnetic head.

First, as shown in FIG. 14, a substrate 101 having a predetermined size for preparing a thin film magnetic head is prepared. A nonmagnetic substrate or a magnetic substrate 101 is typically provided with a diameter of 100 mm and a thickness of 2 mm.
Next, as shown in FIG. 15, the surface of the substrate 101 is polished smoothly, and an insulating film, in this example, an alumina film 102 is sputtered on the polished surface of the substrate 101 to a thickness of about 0.5 μm. Form a film.

  Next, as shown in FIG. 16, on the alumina film 102 of the substrate 101, a metal film such as Ti having a thickness of about 100 nm is used as a resistance sensor for determining the depth of the thin film magnetic head by means of a tape with abrasive grains. A resistor 103 made of a metal film is formed by forming a thick film and etching with a photoresist formed into a predetermined shape. Depth conductors 104 [104A, 104B] connected to both ends of the resistor 103 are formed by electroplating to form a depth polishing sensor 105 using a resistance sensor.

  Next, as shown in FIG. 17, on the surface of the substrate 101 on which the depth polishing sensor 105 is formed, an insulating film having a required thickness so as to cover the depth polishing sensor 105, in this example, the alumina film 106 is about 500 nm. The film is formed to a thickness of. Thereafter, a plating base film 111 for forming a lower magnetic core on the surface of the alumina film 106 by electroplating is formed with a film thickness of about 100 nm, for example.

  Next, as shown in FIG. 18, a plating frame 107 for forming a lower magnetic core by electrolytic plating is formed at a predetermined position on the plating base film 111 of the substrate 101. The plated frame 107 is formed of a photoresist so that the magnetic pole width exposed on the sliding surface of the lower magnetic core becomes the shape of the lower magnetic core (see FIG. 12) so as to be larger than the predetermined track width Tw by the width RPWU. It is formed using.

  Next, a ferromagnetic thin film is formed on the entire surface of the substrate including the inside and outside of the plating frame 107 by electrolytic plating. Thereafter, as shown in FIG. 19, the ferromagnetic thin film 109 ′ outside the other plating frame 107 is selectively removed while leaving the ferromagnetic thin film 109 ′ inside the plating frame 107.

  Next, as shown in FIG. 20, the plating frame 107 is removed, and the exposed plating base film 111 is removed by etching using the remaining ferromagnetic thin film 109 'as a mask, so that the lower layer magnetic core 309 having a rough shape is formed. Form. At this time, a part of the coarse lower layer magnetic core 309 becomes connection portions 312A and 312B of the lead conductor of the thin film coil to be formed later.

  Here, the width RPWU will be described with reference to FIGS. The width RPWU of the lower layer magnetic core having a rough shape takes Df2 which is the position farthest from the track width Tw of the etching resist at the tip pole end as an index, and the upper layer magnetic core thickness t1, the lower layer magnetic core thickness t2, and the recording gap film If the thickness g and the azimuth angle are θ, Df2− (t1 + g) × tan (θ) ≧ RPWU ≧ 0 and (0.5 × t2 + g) × tan (θ) ≧ RPWU ≧ 0 are satisfied. Take the value.

  Next, as shown in FIG. 21, a recording gap film 110 made of alumina or the like is formed so as to cover the coarse lower magnetic core 309. In this example, the recording gap 110 is formed by forming an alumina film having a thickness of about 200 nm by sputtering or the like.

  Next, as shown in FIG. 22, a part of the alumina film 110 that becomes a recording gap is patterned by etching, and openings 113 </ b> A and 113 </ b> B from which part of the connection portions 312 </ b> A and 312 </ b> B of the coarse lower magnetic core 309 are exposed. Form. Thereafter, the surface of the recording gap film 110 is polished and flattened so that the recording gap film 110 has a predetermined thickness, for example, about 180 nm.

  Next, as shown in FIG. 23, a thin film coil 114 that performs electromagnetic conversion is formed on the surface of the substrate. That is, for example, a Cu plating base film (not shown) is formed on the recording gap film 110 with a film thickness of about 100 nm, and then electrolytically plated through a photoresist mask with a film thickness of 3 μm so as to have an opening in a coil shape. A Cu film having a thickness of 2.7 μm is formed. Thereafter, the photoresist mask is removed, and the plating base film is removed by, for example, ion milling to form a thin film coil 114 made of a Cu film. At this time, a part of the thin film coil 114 is connected to the connection portions 312A and 312B on the side of the coarse lower layer magnetic core 309 through the openings 113A and 113B.

  Next, as shown in FIG. 24, an upper core planarizing film 115 is formed on the surface corresponding to the coarse lower magnetic core 309 and the thin film coil 114 by an insulating film for forming the upper magnetic core. The upper core planarizing film 115 is a base film for planarizing the upper magnetic core formed on the thin film coil 114, and is a film for insulating the thin film coil 114 from the upper magnetic core. The upper core planarizing film 115 is formed by applying a photoresist having a thickness of, for example, 4 μm on the thin film coil 114 so as to be equal to or greater than the thickness of the thin film coil 114 and thermally curing.

Next, a plating base film for forming the rough upper magnetic core by electrolytic plating is formed by sputtering, for example.
Next, as shown in FIG. 25, a plating frame 117 for forming a coarse upper magnetic core shape is formed. The plating frame 117 is formed such that the width of the portion corresponding to the tip magnetic pole end of the upper magnetic core is larger than the width of the tip magnetic pole end of the lower layer magnetic core 309 having a rough shape. That is, since the upper magnetic core is trimmed by etching only on one side after being formed into a rough shape, the width of the portion corresponding to the magnetic pole end at the tip of the upper magnetic core of the plating frame 117 is set to the coarse lower magnetic core 309. It is formed to be larger than the track width Tw finally determined so as to be larger than the tip end portion of the magnetic pole. At this time, it is formed so as to be larger than the width RPWT removed by etching (see FIG. 11). The plating frame 117 is formed of a photoresist having a film thickness of 4 μm, for example, similarly to the plating frame 107 for forming the lower magnetic core described above.

  Next, as shown in FIG. 26, an upper magnetic core 118 having a rough shape restricted by the plating frame 117 is formed. That is, after an upper magnetic core thin film 118 [118A, 118B] having a required film thickness, for example, 3.5 μm, is formed on the plating base film having the plating frame 117 by electrolytic plating (similar to FIG. 6C described above), The upper magnetic core thin film 118A inside the plating frame 117 is protected with a photoresist, and the unnecessary upper magnetic core thin film 118B outside the plating frame 117 is etched away. Thereafter, the photoresist is removed, an unnecessary plating base film is removed, and the plating frame 117 is further removed to form the upper magnetic core 118. The upper magnetic core 118 is connected to the lower magnetic core 309 through the opening 113B.

  Here, when viewing the area of the magnetic core as viewed from above, the area of the lower magnetic core 309 is formed larger than the area of the upper magnetic core 118.

  Next, as shown in FIG. 27, a photoresist mask 120 having an opening 119 for trimming one side of the magnetic pole end at the tip of the coarse upper magnetic core 118 in an inclined manner on the entire surface including the upper magnetic core 118. Form. In the photoresist mask 120, the inner surface of the opening 119 is inclined so that the magnetic pole end surface of the upper magnetic core 118 having a rough shape is more than the azimuth angle from the normal direction perpendicular to the substrate (wafer) surface, and has a predetermined track width Tw. In consideration of the photoresist receding amount, the lower end of the photoresist mask opening 119 is formed at a position shifted in the track width Tw direction by a distance Df from the magnetic pole end portion of the lower magnetic core 109 that is not etched (as described above). (See the same FIG. 7 and FIG. 8). To incline the inner surface of the opening 119, the opening 119 is patterned and then heat-treated.

  Next, as shown in FIG. 28, the surface of one side of the magnetic pole ends of the upper magnetic core 118 and the lower magnetic core 309 is formed on the photoresist mask by plasma ion etching using Ar gas or the like through the photoresist mask 120, for example. The upper layer magnetic core 121 having the inclined surfaces 126 and 326 on one side of the end magnetic pole end portions 121A and 319A, which are processed along the inclined surface of the opening 119 of the 120 and finished in the final shape. And the lower magnetic core 319 is formed. At this time, the etching time is adjusted so that the width parallel to the recording gap is equal to the Tw width, facing the sliding surface of the upper magnetic core 118.

By this etching step, the uppermost portion in the thickness direction of the upper magnetic core 121 is etched in the depth depth direction by 0 <DpT ≦ (2 × t1) μm in the depth depth direction (see FIGS. 12A and 12B). When DpT is etched to exceed 2 × t1 μm, magnetic saturation near the depth zero of the upper magnetic core 121 appears remarkably.

  Next, as shown in FIG. 29, a planarization insulating film such as an alumina film 123 is formed on the entire surface. That is, an alumina film is formed on the substrate to a thickness including the maximum height difference on the substrate and the polishing allowance for flattening polishing. In this example, an alumina film with a film thickness of 30 μm is formed by sputtering, and flattening polishing is performed. Then, a planarized alumina film 123 necessary for attaching the protective substrate is formed.

  Next, although not shown, in order to form the external connection terminals of the thin film coil 114 and the depth polishing sensor 105, the flattened film 123 is etched at the place where the external connection terminals of the respective lead conductors are to be formed. Remove. Next, in order to form the external connection terminals by plating, a plating base film is formed, and after forming a photoresist into the shape of the external connection terminals, a plating film is formed to a thickness of 100 μm, for example. The thin film magnetic head wafer is formed by removing.

  Next, as shown in FIG. 30, the thin film magnetic head wafer is cut into a predetermined shape to form a thin film magnetic head block 124. Thereafter, the thin film magnetic head block 124 and the substantially substrate are bonded together with an adhesive, and cylindrical polishing is performed so as to follow the shape of the sliding surface, and the thin film head chip is divided. After the division, a thin film head chip is attached to the base plate for mounting on the rotating drum with an adhesive, and tape polishing is performed while measuring the resistance of the resistor 103 so as to obtain a predetermined depth using the depth polishing sensor 105. A thin film magnetic head as shown in FIG. 13 is completed.

According to the above-described thin film magnetic heads according to the first and second embodiments, the recording pattern is not disturbed in the adjacent track affected by the leakage magnetic flux from the end of the upper magnetic core, and the output is reduced due to the recording pattern disorder. Can be prevented. Therefore, a high-density and stable helical tape scanning thin film magnetic head can be provided.
In the thin film magnetic head according to the second embodiment, as shown in FIGS. 12 and 13, one side of each of the magnetic pole end portions 121A and 319A is formed with the entire thickness of the upper magnetic core and half the thickness of the lower magnetic core. When the inclined surfaces 126 and 326 are formed by continuously obliquely cutting up to the following, the inclined track edges of the upper and lower magnetic cores 121A and 319A can be aligned. As a result, the recording blur due to the submicron deviation of the upper and lower magnetic cores is eliminated, and the recording pattern quality is improved as compared with the case where there is a slight deviation of the upper and lower magnetic core track edges.
In addition, according to the manufacturing methods according to the first and second embodiments, a high-density and stable helical tape scan type thin film magnetic head can be manufactured without causing such recording pattern disturbance.

1 is a schematic configuration diagram showing an example of an embodiment of a thin film magnetic head according to the present invention. It is a cross-sectional view which passes along the front-end | tip magnetic pole end part of the magnetic core of FIG. It is a longitudinal cross-sectional view which passes along the magnetic core of FIG. It is a schematic block diagram which shows the other example of embodiment of the thin film magnetic head based on this invention. It is explanatory drawing of the recording pattern recorded using the thin film magnetic head of FIG. FIGS. 1A to 1C are process diagrams (part 1) illustrating a main part of a manufacturing process according to the present embodiment. It is process drawing (the 2) which shows the principal part of the manufacturing process which concerns on AB this Embodiment. A and B are a plan view in the middle of a process of the method of manufacturing a magnetic head according to the first embodiment and a front view as seen from the tape sliding surface side. 1A and 1B are a plan view of a thin film magnetic head according to a first embodiment and a front view as seen from the tape sliding surface side. 1 is a perspective view of a thin film magnetic head according to a first embodiment. A and B are a plan view in the middle of a process of a method of manufacturing a magnetic head according to a second embodiment and a front view seen from the tape sliding surface side. A and B are a plan view of a thin film magnetic head according to a second embodiment and a front view as seen from the tape sliding surface side. FIG. 6 is a perspective view of a thin film magnetic head according to a second embodiment. FIG. 6 is a manufacturing process diagram (No. 1) of a thin film magnetic head according to the embodiment; FIG. 7 is a manufacturing process diagram (No. 2) of the thin film magnetic head according to the embodiment; FIG. 7 is a manufacturing process diagram (No. 3) of the thin film magnetic head according to the embodiment; FIG. 6 is a manufacturing process diagram (No. 4) of the thin film magnetic head according to the embodiment; FIG. 10 is a manufacturing process diagram (No. 5) of the thin film magnetic head according to the embodiment; FIG. 6 is a sixth manufacturing process diagram of the thin-film magnetic head according to the embodiment. FIG. 7 is a manufacturing process diagram (No. 7) for the thin-film magnetic head according to the embodiment. FIG. 11 is a manufacturing process diagram (8) for the thin-film magnetic head according to the embodiment; It is a manufacturing process figure (the 9) of the thin film magnetic head which concerns on this Embodiment. FIG. 10 is a manufacturing process diagram (No. 10) of the thin film magnetic head according to the embodiment. It is a manufacturing process figure (the 11) of the thin film magnetic head which concerns on this Embodiment. It is a manufacturing process figure (the 12) of the thin film magnetic head which concerns on this Embodiment. It is a manufacturing process figure (the 13) of the thin film magnetic head which concerns on this Embodiment. It is a manufacturing process figure (14) of the thin film magnetic head which concerns on this Embodiment. FIG. 17 is a manufacturing process diagram (No. 15) of the thin film magnetic head according to the embodiment; FIG. 16 is a manufacturing process diagram (No. 16) of the thin-film magnetic head according to the embodiment. FIG. 17 is a manufacturing process diagram (17) for a thin film magnetic head according to the embodiment; It is a block diagram explaining a helical tape scanning system. It is a schematic block diagram of the thin film magnetic head used for a helical scan system. It is a perspective view of an example of the conventional thin film magnetic head. It is explanatory drawing of the recording pattern recorded using the thin film magnetic head of FIG. It is a perspective view of the other example of the conventional thin film magnetic head. FIG. 36 is an explanatory diagram of a recording pattern recorded using the thin film magnetic head of FIG. It is explanatory drawing of the scanning direction of a magnetic head, and the easy magnetization domain of a magnetic tape.

  31 .. Thin film magnetic head, 32 .. Nonmagnetic substrate, 33 .. Lower magnetic core, 34 .. Recording gap film, 35 .. Coil conductor, 36 .. Upper magnetic core, 33 A, 36 A. , 37 .. Oblique cut surface, 41.. Thin film magnetic head element, 43, 44 .. Nonmagnetic block, 46 .. Resistance sensor, 51, 56 .. Azimuth head element, 52 .. Nonmagnetic substrate, 53A, 53B ..Lower magnetic core, 54A, 54B..Upper magnetic core, 57..Inclined surface, 61, 62..Recording pattern (recording track), 63..Guard band

Claims (7)

A thin-film magnetic head for azimuth recording using a helical tape scanning method,
An upper magnetic core composed of a magnetic pole end and a wide portion that gradually becomes wider than the magnetic pole end behind the depth zero line and becomes a constant width from the middle; and
A lower magnetic core,
A recording gap formed between the magnetic pole end of the upper magnetic core and the lower magnetic core;
The upper magnetic core is disposed on the leading side in the head running direction which is the track scanning direction to the magnetic recording medium with respect to the lower magnetic core,
One side of the magnetic pole end portion of the upper magnetic core is obliquely cut so as to be an azimuth angle or more from the recording gap,
The range of the diagonal cut from the depth zero line to the wide portion of the magnetic pole end of the upper magnetic core does not exceed 2 × t1 μm (excluding 0), where the thickness of the upper magnetic core is t1.
A thin film magnetic head characterized by that. The thin film magnetic head according to claim 1, wherein one side of the magnetic pole end of the lower magnetic core is obliquely cut in the same manner as one side of the magnetic pole end of the upper magnetic core. 3. The thin film magnetic head according to claim 2, wherein one side of the magnetic pole end portion is removed to the thickness of the upper magnetic core and not more than half of the thickness of the lower magnetic core. A method for manufacturing a helical tape can thin film magnetic head for azimuth recording,
On the surface of the substrate on which the depth polishing sensor by the resistance sensor is formed, the magnetic pole end via the insulating film, and the wide part that gradually becomes wider from the magnetic pole end behind the depth zero line and becomes constant in the middle. Forming a lower magnetic core comprising:
Forming a recording gap film covering the lower magnetic core;
Forming a thin film coil on the recording gap film;
Forming an upper core planarizing film with an insulating film on the surface corresponding to the lower magnetic core and the thin film coil;
Forming an upper magnetic core on the upper core planarizing film, comprising a magnetic pole end portion and a wide portion gradually wider than the magnetic pole end portion behind the depth zero line and having a constant width from the middle; and
A trimming opening for trimming one side of the magnetic pole end portion of the coarse upper layer magnetic core in an inclined manner is provided on the entire surface including the upper layer magnetic core, and the inner surface of the opening is inclined at an azimuth angle or more. Forming a resist mask at a position shifted in the track width direction by a required distance from the magnetic pole end of the lower magnetic core so that the width of the magnetic pole end of the upper magnetic core after etching becomes the track width;
One side of the magnetic pole end of the upper magnetic core is obliquely etched away from the recording gap so as to have an azimuth angle or more along the inclined surface of the opening of the resist mask, and in this etching, the magnetic layer of the upper magnetic core is removed. The upper magnetic core is formed such that the range of oblique cuts from the depth zero line at the extreme portion to the wide portion does not exceed 2 × t1 μm (excluding 0), where the thickness of the upper magnetic core is t1. An etching process,
Forming a planarization insulating film on the entire surface;
And a step of obtaining a predetermined magnetic gap depth using the depth polishing sensor after being divided into thin film head chips. 5. The method of manufacturing a thin film magnetic head according to claim 4, wherein, in the etching step, one side of the magnetic pole end of the lower magnetic core is obliquely cut in the same manner as one side of the magnetic pole end of the upper magnetic core. . 6. The method of manufacturing a thin film magnetic head according to claim 5, wherein, in the etching step, etching is performed to the entire thickness of the upper magnetic core and to half or less of the thickness of the lower magnetic core. The method of manufacturing a thin film magnetic head according to claim 4, wherein a width of a magnetic pole end portion of the upper magnetic core before the etching step is set larger than a final magnetic track width.

Images