KR910000190B1 - Flying magnetic head - Google Patents

Abstract

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Description

Floating Magnetic Head

1 is a perspective view of a flying magnetic head in accordance with one embodiment of the present invention.

2 is a cross sectional view taken along line A-A of FIG.

3 is a perspective view of a floating magnetic head according to another embodiment of the present invention.

4A-4F are perspective views illustrating the steps of manufacturing the floating magnetic head of the present invention.

5 is a perspective view of a Winchester-type magnetic head.

6 is a perspective view of a mixed-type magnetic head.

* Explanation of symbols for main parts of the drawings

1, 2: core 3: slide rail

8 L-shaped protrusion 11 Glass layer

18: magnetic gap 19, 19 ': recess

37: upper protrusion 51: magnetic slider body

101, 103: core blocks 107, 107 ', 108, 108': notch

110: glass rod

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a floating magnetic head for use in a magnetic disk drive or the like, and more particularly, to a floating magnetic head floating on a magnetic recording medium due to air flow due to relative movement of the magnetic head and the magnetic recording medium.

Magnetic recording systems utilize magnetic heads, which are well known in the art to rise into the air stream relative to the magnetic recording disk surface. Reducing the gap between the magnetic head gap and the magnetic recording medium improves system performance. At the same time, the closer the magnetic head is to the magnetic recording medium, the more likely the magnetic head is to come into contact with the magnetic recording medium.

Typically, the magnetic head contacts the magnetic disk while the magnetic disk is not rotating, and when the disk starts to rotate, the magnetic head begins to float by the air flow therebetween. The magnetic head floats on the magnetic disk at fixed intervals while the disk is rotating, but the head comes in contact with the magnetic disc again when the disk is stopped. This process is called a contact-start-stop (CSS) cycle. In order to withstand the impact of contact with the magnetic disk during the CSS cycle, the magnetic head is required to withstand such an impact well. Such a characteristic of the magnetic head is called a CSS characteristic.

Efforts have been made to provide magnetic heads that can float as closely as possible on magnetic disks and at the same time have good CSS properties.

Typical, conventional floating magnetic heads are the Wichester-type magnetic heads shown in FIG. 5, as disclosed in US Pat. No. 3,823,416. The Winchester-type magnetic head has a magnetic slider body 51 and a magnetic core 52, which has a pair of longitudinal side rails 53, 54 and a central rail 55. Each rail has a taper-flat profile with respective planar portions 56, 57 and 58. The three rails are separated into bleed slots 59 and 60 which provide a passage for allowing unnecessary air to escape from the air bearing outer rail surface during the floating operation without giving the slider an effective air bearing surface or changing the floating height. It is. The magnetic core 52 is bonded to the rear front surface of the slider main body 51 by the glass 61, and the conducting wire is wound around it. The magnetic gap 62 is defined by the center rail 55 and the magnetic core 52.

However, since the magnetic gap 62 is provided between the central rail 55 and the thin portion of the magnetic core 52, the winchester-shaped magnetic head does not have good CSS characteristics.

A mixed-type magnetic head as shown in FIG. 6 is disclosed in, for example, Japanese Utility Model Publication No. 57-189173. The magnetic head has a slider body 61 having a pair of longitudinal rails 62, 63 with upwardly inclined ends 64, 65. Internal to the lower side of the side rails is a magnetic core 66 consisting of two core pieces with a magnetic gap 67. The magnetic core 66 is secured in the slot 69 of the side rail 62 with glass 68.

Since the magnetic gap 67 is coplanar with the surface of the side lane 62, the mixed-type magnetic head has a relatively improved CSS characteristic. However, the magnetic head is not easy to manufacture and requires high precision and very complicated steps. For this reason, mainly bonded magnetic cores 66 must be inserted and fixed in the slots 69 of the side rails 62 for each head. In fact, since the magnetic core 66 is very small, the assembling operation needs to be performed by hand using a microscope.

It is therefore an object of the present invention to provide a floating magnetic head having good CSS properties.

Another object of the present invention is to provide a floating magnetic head of a structure that can be easily manufactured.

In view of the above object, the present inventor has conducted subjective research on the structure of the floating magnetic head. As a result, it has been found that good CSS characteristics can be achieved without the need for complicated manufacturing steps by forming a magnetic gap with two core bodies directly on one of the slide rails of the magnetic head.

That is, the floating magnetic head according to the present invention comprises a first core and a second core bonded to each other by glass, and includes a pair of slide rails extending longitudinally on both sides of the head, and at least one of the slide rails. A gap defined by the first and second cores on the rail and extending laterally, and a pair of recesses filled with glass and located on both sides of the gap, thereby determining the track width of the gap.

Referring to FIG. 1, a floating magnetic head according to the present invention is composed of a first core 1 and a second core 2. The first core 1 consists of a slide body having a pair of longitudinal slide rails 3, 4 with upwardly inclined ends 5, 6. By the way, the magnetic head is shown upside down for convenience in the accompanying drawings, it should be noted that the word "upward" means "downward" in this drawing. The second core has a lower surface with the same profile as that of the first core, so that the slide rails 3, 4 extend smoothly.

2 shows a cross section of the first and second cores 1, 2 bonded to each other. The first core has an upper projection 7 at the front end, an L-shaped projection 8 near the rear anterior end, and a triangular transverse projection 9 at the anterior anterior end. The L-shaped protrusion 8 has a horizontal protrusion 10. On the other hand, the second core 2 is a flat plate having a profile corresponding to that of the first core 1. The second core 2 is glass bonded to the tip end of the triangular protrusion 9 and the horizontal protrusion 10. (11) shows a glass layer for reinforcing the glass bonding of the said 1st and 2nd core.

As shown in FIG. 1, the L-shaped protrusions 8 and the corresponding protrusions 12 of the second core 2 are characterized by their outer surface being recessed laterally from the side surface of the protrusions 7. With a relatively wide gap 13 and the intermediate surface 14 of the first core 1 and the intermediate surface 15 of the second core 2 for winding the conductors between their inner surfaces; Have the same reduced width. In addition, the upper surface 16 of the first core 1 has a portion 17 inclined downward at the trailing front end. The downwardly inclined portion 17 extends linearly past the glass layer 11 towards the second core 2. As mentioned below, the downwardly inclined portion 17 and the gap 13 can be formed by polishing after assembly.

As is apparent from FIG. 1, the magnetic gap 18 with the track width Tw is defined by the first and second cores 1, 2 close to the rear front end of the magnetic head. Provided on both sides of the magnetic gap 18 are a pair of resets 19, 19 ′ filled with glass. In this embodiment, each recess is defined by notches the first and second cores 1, 2. However, it will be noted that the recess can be defined by a notch in which only one of the first and second cores 1, 2 is formed.

The track width Tw of the magnetic gap 18 can be adapted by varying the side lengths of the recesses 19 and 19 'respectively filled with glass. At any length of the glass filled recesses 19, 19 ′, the magnetic gap 18 is flush with the surface of the slide rail 3. Therefore, it is very resistant to impacts caused by contact with the magnetic disk surface during operation, in particular during start up and stop. In other words, the magnetic gap 18 of the present structure has excellent CSS characteristics.

In the present embodiment, the conductor 20 is wound around the vertical projection 12 of the second core 2. However, if desired, it may also be wound around the horizontal protrusion 10 of the first core 1.

In the preferred embodiment both the first and second cores 1, 2 are made of magnetic material such as ferrite. The magnetic thin metal layer can be formed, for example, by sputtering on the gap-forming surfaces of the first and second cores 1.2. In this case, the magnetic thin metal layer should have a higher saturation magnetic flux density than the magnetic core. The magnetic head having the magnetic thin metal layer can use a saturated coercive recording medium and has good electron conversion efficiency.

In another preferred embodiment, the first and second cores 1, 2 are non-magnetic if a magnetic thin metal layer is formed on the gap = forming surface of the first and second cores 1, 2. Can be. The gap structure is composed of only the magnetic thin metal layer, so that almost pseudo-gap effect is reduced, thereby improving frequency characteristics.

3 shows a floating magnetic head according to another embodiment of the present invention, and is essentially the same as that shown in FIG. 1 except for the upper projections of the first and second cores 31, 32. Therefore, the description of the same parts will be omitted. The upper protrusion 37 is laterally recessed by a predetermined distance from the side surface 33 of the head. Similarly, the upper protrusion 38 of the first core 31 and the upper protrusion 39 of the second core 32 also laterally dent from the side surface 33 by the same distance. Because of this structure, the lower slope 17 as shown in FIG. 1 is not necessary for the magnetic head of FIG. A separation core piece 40 having a width equal to the width of the protrusions 38 and 39 is joined to the protrusions 38 and 39. In the above structure, the conductive wire 41 is wound around the separating core piece 40 in advance, and the core piece 40 is joined with the protrusions 38 and 39 to facilitate the winding of the conductive wire. Of course, the conductive wire may be wound around the protrusion 39 with or without bobbins before joining the separating core pieces 40.

Fabrication of the floating magnetic head of the present invention will be described in detail with reference to FIGS. 4A to 4F.

In FIG. 4A, a first core block 101 and a second core block 103 having longitudinal grooves 102 are prepared.

As shown in FIG. 4A, the second core block 103 is a thin plate having a width equal to the width of the first core block 101. The opposing surfaces 104, 105, 106 of the first and second core blocks 101, 103, which should be joined to each other, are mirror-finished.

In FIG. 4B, a pair of inclined notches 107, 107 'are formed at the edges of the opposing surface 104 with a distance equal to the track width Tw. Corresponding beveled notches 108, 108 'are also formed at the edges of the opposing surface 106 with the same track width Tw. Many such pairs are formed at intervals equal to the lateral width of the magnetic head to be produced at the corners of the first core block 101 as well as at the corresponding corners of the second core block 103. As a result, when the first and second core blocks 101, 103 are assembled, the corresponding notches 107, 108 and 107 ′, 108 ′ have a pair of recesses 109 as shown in FIG. 4C. 109 ').

The glass rod 110 is located in the longitudinal grooves 102 as shown in FIG. 4D. Because the recesses 109, 109 ′ partially reciprocate with the longitudinal grooves 102, the recesses may be filled with glass when the glass rod 110 is dissolved. The glass layer 111 is also formed in the vicinity of the recesses 109 and 109 'to reinforce the glass bonding as shown in FIG. 4E. In the above connection, it is noted that the figures are shown upside down in order to clearly understand the manufacturing steps.

10^-7내지 130

10^-7deg^-1를 가진 납-규산 유리이다.The glass used to join the first and second cores has a coefficient of thermal expansion as close as possible to that of the core material. Typical example of good glass, coefficient of thermal expansion 7

10 ^-7 to 130

Lead-silicate glass with 10 ⁻⁷ deg ⁻¹ .

Glass bonding is carried out at 500 degrees to 900 degrees Celsius for 15 to 60 minutes. In order to ensure glass bonding, a thin glass layer can be previously formed on the gap-forming surfaces of the first and second core blocks 101, 103.

After completion of the glass bonding, a longitudinal direction 120 is formed on the upper surface of the first core block 101 so that the upper protrusion 121 and the L-shaped protrusion 122 are shown in FIG. 4f. Is formed. The upper and lower surfaces are appropriately polished. The bonded block assembly is cut into each magnetic head body. In order to provide the magnetic head of FIG. 1, the L-shaped protrusion 122 and the second core block 103 are machined diagonally to provide a downwardly inclined portion 17 and the gap 13. Processed. Because of the inclination of the portion 17 and the lower surface of the gap 13, machining can be carried out without being disturbed by the upper projection 7. The lead winding is finally conducted to finish the head.

However, a magnetic thin metal layer may be previously formed on the gap-forming surfaces 104, 105, and 106 of the first and second core blocks 101, 103 if desired. Even in such cases, the subsequent procedure is essentially the same.

The first and second cores are made of a magnetic material such as manganese zinc ferrite or a nonmagnetic material such as MnO-NiO, TiBaO ₃ and TiCaO ₃ . Magnetic thin metal layers that can be formed on the gap-forming surface are made, for example, of co-base alloys and iron-aluminum-silicon alloys. The glass used for the fitting can be, for example, PbO-ZnO-B ₂ O ₃ -SiO ₂ glass.

As mentioned above, the magnetic gap, whose track width is determined by a recess filled with a pair of adjacent glass, is flush with one of the slide rails extending longitudinally on both side sides of the floating magnetic head according to the invention. Therefore, it is very strong against any impact caused by contact with the magnetic recording disc. This means that the magnetic head of the present invention has the same CSS properties as those of the mixed-type magnetic head. In addition, as illustrated in FIGS. 4A to 4F, the magnetic head of the present invention can be manufactured without complicated steps. Therefore, it is suitable for mass production at a low price.

Although the magnetic head with one magnetic gap has been described with reference to the accompanying drawings, it should be noted that two magnetic gaps may be provided on both slide rails of the head. In addition, any other modification may be adopted without departing from the scope of the present invention.

Claims (14)

In a floating magnetic head composed of a first core 1 and a second core 2 bonded together by glass to each other, a pair of slide rails 3 and 4 extending longitudinally on both sides of the head, and the slide A gap 18 defined by the first core 1 and the second core 2 and laterally extending on at least one of the rails 3, 4, and filled with glass 11 and the Floating magnetic head, characterized in that it has a pair of recesses (19, 19 ') located on both sides of the gap (18), thereby determining the track width (Tw) of the gap (18). The method of claim 1 wherein each of the first core 1 and the second core 2 has a pair of notches, and the recesses 19, 19 ′ are provided with the first and second cores 1, 2. A floating magnetic head, which is defined by the corresponding notch in 2). 2. The window for conducting wire winding on the gap 18 is defined by the side grooves of the first core 1 and the vertical extension 12 of the second core 2. Floating magnetic head characterized by. Floating magnetic head according to claim 3, characterized in that the conductor (20) is wound around the vertical extension (12) of the second core (2). The method of claim 1, wherein the vertical extension portion 38 of the first core 31, the vertical extension portion 39 of the second core 32, and the first and second cores 31, 32 Floating magnetic head, characterized in that the window for conducting wire winding is defined on the gap by a longitudinal core piece (40) bonded to the vertical extension (38, 39). Floating magnetic head according to claim 5, characterized in that the conducting wire (41) is wound around the longitudinal core piece (40). Floating magnetic head according to claim 5, characterized in that the conductor (41) is wound around the vertical extension (39) of the second core (32) by a bobbin. 8. Floating magnetic head according to any one of the preceding claims, wherein the first and second cores are made of magnetic material. 10. The floating magnetic head of claim 8 wherein the magnetic material is manganese-zinc ferrite. 9. The flotation according to claim 8, further comprising a magnetic thin metal layer formed on at least one of the opposing surfaces of the gap 18, the magnetic thin metal layer having a higher saturation magnetic flux density than the first and second magnetic cores. Type magnetic head. 11. The floating magnetic head of claim 10 wherein the magnetic thin metal layer is an amorphous cobalt-based alloy. 8. The magnetic strip according to claim 1, wherein the first and second cores 1, 2 are made of nonmagnetic material and the head comprises a magnetic thin metal layer formed on each opposing surface of the gap. Floating magnetic head characterized in that it further comprises. 13. The floating magnetic head of claim 12, wherein the nonmagnetic material is MnO-NiO, TiBaO ₃ and TiCaO ₃ ceramics. 14. The floating magnetic head of claim 13, wherein the magnetic thin metal layer is made of an amorphous cobalt-based alloy or senddust.

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