JPS5990216A - Winding type thin-film magnetic head and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a thin-film head which has an improved reproduction output, etc., by providing a groove for winding to at least either of a couple of nonmagnetic substrates, forming a magnetic thin film which increases in width from a pole piece part to a winding part, and beveling the edge of the magnetic film and the edge of the groove part. CONSTITUTION:A hollow part 11 and the groove 10 for the winding are formed in at least either of nonmagnetic substrates 2 and 2', i.e. substrate 2 and magnetic thin films 4 and 4' are formed on the opposite surfaces of the substrates 2 and 2' so that the width W increases from pole piece parts 13 and 13' to the winding part and the width W' of the winding part is >=5 times as large as the width W of the pole piece part 13. Further, the edge 4a of the film 4 of the winding part and the edge 10b of the groove 10 are beveled; the winding 8 contacts with the wall of the groove 10 and the film 4, the inductance of the winding 8 is minimized, and the generation of a noise at the edge parts is prevented. Thus, the winding 8 is turned many times easily to obtain the head which has the improved reproduction output and superior wear resistance, mechanical strength, high frequency characteristics, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thin film magnetic head for a magnetic recording/reproducing device using a magnetic thin film.

Conventionally, various types of thin film magnetic heads have been proposed, one of which is called an integrated type head. The integrated head is a thin film magnetic head manufactured using well-known integrated circuit manufacturing technology, that is, thin film forming technology and patterning technology such as photolithography, and has the following features: Easy to track.

(2) Uniformity of characteristics and ease of mass production.

(3) Has high-speed switching characteristics, at least 60M
Usable up to Hz.

(4) In the case of a multi-track configuration, there is less crosstalk due to magnetic coupling between adjacent magnetic cores.

It has the following advantages. On the other hand, such an integrated thin-film magnetic head requires a process of vapor deposition, electrodeposition, and masking to form its components, such as a magnetic layer corresponding to the magnetic core, a conductor layer corresponding to the coil, and a gear part spacer. It has the disadvantage that it requires the use of various complicated processes.

In particular, the winding formation, that is, the formation of the conductor layer, must be performed seamlessly above and below the magnetic layer, and it is necessary to maintain insulation from other layers than the conductor layer, making it extremely difficult to increase the number of coil turns. Ta. The increase in the number of turns of the coil makes the manufacturing process extremely difficult and is one of the causes of a significant decrease in yield. Therefore, if the number of coil turns is reduced in order to simplify the manufacturing process of a thin-film magnetic head, the recording current must be increased, and it is necessary to maintain insulation between each conductor layer and between a conductor layer and a portion other than the conductor layer. becomes difficult. Since there is a limit to the increase in recording current, the playback output naturally becomes small, and it becomes necessary to provide a step-up transformer in the readout circuit, which leads to miniaturization, weight reduction, and cost reduction of magnetic recording and playback devices. That's not a good thing.

As mentioned above, the efficiency of the coil as a magnetic circuit in a thin film magnetic head called an integrated head is only about 1/10 that of a normal bulkhead type coil.

In order to solve the drawbacks of such an integrated head, Japanese Patent Application Laid-Open No. 1986-
No. 19514, as shown in FIG. This is a so-called wire-wound type thin film magnetism, which has a non-magnetic spacer film 6 that fills the operating gap formed by butting the thin films together, and the coil winding is constructed by surrounding the magnetic thin film 4 with a continuous conducting wire 8 similar to a bulkhead. The wire-wound thin film magnetic head of which head 1a was proposed has the advantages of conventional integrated magnetic heads, and also makes it easier to increase the number of coil turns, which was one of the disadvantages of integrated magnetic heads. This enabled significant improvements in recording magnetic field and output.

The present invention relates to an improvement of the above-mentioned wire-wound thin film magnetic head. The wire-wound 3-type thin film magnetic head solves the drawbacks of the integrated thin film magnetic head, which attempts to construct the originally three-dimensional coil with a two-dimensional thin film.The magnetic core is made of a thin film, and the winding This is constructed using a continuous conductive wire similar to the conventional bulkhead, but the conventional wire-wound thin film magnetic head has been insufficient in reducing the inductance of the winding itself as much as possible. Furthermore, when a magnetic head is configured to accommodate narrower tracks, the mechanical strength and abrasion resistance of the magnetic head are insufficient.

Accordingly, a principal object of the present invention is to provide a wire-wound thin film magnetic head that retains the advantages of an integrated thin film magnetic head while minimizing the inductance of the winding itself. More specifically, the purpose of the present invention is to improve the efficiency of the winding, so that even if the inductance is kept to the same value as a conventional thin film magnetic head, the number of coil turns can be increased to improve the reproduction output. An object of the present invention is to provide a wire-wound thin film magnetic head that can maintain good high frequency characteristics, which is the greatest advantage of magnetic heads.

Another object of the present invention is to provide a wire-wound thin film magnetic head that can record even on recording media with high coercive force by using a metal ferromagnetic material with high saturation magnetization for the magnetic thin film (magnetic layer). .

The purpose of the present invention is to have sufficient mechanical strength and wear resistance,
It is an object of the present invention to provide a wire-wound thin film magnetic head which can be suitably used as a head for narrow tracks.

Still another object of the present invention is to provide a method for manufacturing a wire-wound thin film magnetic head that can extremely quickly, accurately, and easily manufacture wire-wound thin film magnetic heads in large quantities on a monthly basis. That's true.

Next, the wire-wound thin film magnetic head according to the present invention will be described in detail with reference to embodiments illustrated in the drawings.

The wire-wound thin film magnetic head 1 according to the present invention has two magnetic heads arranged opposite to each other, as understood with reference to FIGS. 2 and 3.
It has a pair of non-magnetic substrates 2, 2'.

Magnetic layers, that is, magnetic thin films 4, 4' are formed on opposing surfaces of the substrates 2, 2', and the substrates 2, 2' are butted against each other so that the magnetic thin films 4, 4' are in close contact with each other. are combined together. In this embodiment, grooves 10 and 10a are formed in at least one of the substrates 2 and 2', so that a space 11 is formed at the junction of both magnetic thin films 4 and 4'.
is formed.

Further, the thin film magnetic head 1 is connected to a recording medium such as a magnetic tape (
The operating surface (not shown), that is, the sliding surface 12, has a
There are pole piece portions 13, 13' for exchanging magnetic flux with the recording medium during recording and reproduction, the width of which corresponds to the predetermined recording track width. A spacer film 6 is interposed between the two magnetic thin films 4, 4' to form a predetermined gap. Furthermore, a winding 8 is wound in the grooves 10 and 10a of the substrate 2 so as to surround the magnetic thin film 4 on the substrate 2.

In the present invention, the magnetic thin films 4, 4' are not formed with a constant width on the surfaces of the substrates 2, 2', but are formed in the winding portion where the winding 8 is applied, that is, the void 11 or the groove 10a. From area to sliding surface 1
2, that is, the width (W
) is configured to gradually decrease (from the maximum width W' of the magnetic thin film to the width W of the pole piece portion). To explain in more detail with reference to FIGS. 3 and 4, the magnetic thin films 4, 4' are formed to satisfy the following equation.

g/w<G/W (preferably W'≧5w) w: Width of both magnetic thin films at the pole piece part of the thin film head g: Gap W between both magnetic thin films at the pole piece part of the thin film head: Width G of both magnetic thin films in the portion from the rear of the pole piece part of the thin film head to the winding part (including the winding part): Gap between both magnetic thin films at the position of the magnetic film width (W) Further, a preferred embodiment is shown below using specific numerical values.

g = 0.2 to 0.4 μm w = 5 to 20 μm G' (maximum value of G) = 0.1 to 0.2 mm W' (maximum value of W) = 0.1 to 0.2 mm L = 10 to 50 μm Here The dimension (L) indicates the length of the magnetic thin film portion uniformly formed with the width (w) of the pole piece portions 13, 13', and provides a wear allowance for the tip of the magnetic thin film head. do.

As described above, the thin film magnetic head according to the present invention has the effect that the width of the magnetic thin film is increased from the pole piece part to the winding part, so that the current supply to the winding wire during recording can be reduced. Since the width of the magnetic thin film in the rear gap portion of the magnetic head, that is, the region from the winding portion to the rear end portion 14 of the head is wide, the magnetic resistance of the rear gap portion can be suppressed to an extremely low level, thereby improving head efficiency. I can do it.

Further, in the head 1 of the present invention, the width W of the magnetic thin film in the winding portion and the region extending from the winding portion to the rear end portion 14 of the head is equal to the width of the recording track, that is, the width of the magnetic thin film of the pole piece portion 12. lol
Due to its wider configuration, it has the advantage that even when used in a narrow track head of, for example, 20 μm or less, winding can be facilitated and the mechanical strength of the head can be maintained sufficiently high.

Furthermore, the film thickness t of the magnetic thin films 4, 4' is uniformly formed to a certain value, for example, 3 μm or more, but it is formed so that it gradually increases from the pole piece part 12 toward the rear end part 14 of the head, for example. 3μm in the pole piece part, 1μm in the rear gap part
It can also be configured to have a thickness of 0 μm. With such a configuration, magnetic resistance tends to concentrate on the pole piece portion 12, and head efficiency can be increased.

Further, in the thin film magnetic head according to the present invention, the magnetic thin film 4 has the winding wire 8 bent in order to sufficiently adhere to the magnetic thin film 4 in the winding portion and reduce the length of the conducting wire per number of turns; Preferably, the corners 4a and 10b of the groove 10 of the substrate 2 are chamfered. This chamfering process allows the inductance of the winding itself to be minimized, and when the inductance is set to a certain value, the number of turns in the coil can be increased compared to conventional thin film magnetic heads, improving the reproduction output. In particular, good high frequency characteristics can be maintained. In addition, by chamfering the sharp edges of the magnetic thin film 4 in the winding section, the generation of a minute magnetic domain structure at the edge, which becomes a noise source during high frequency operation, is eliminated or made difficult to occur. be able to.

The degree of chamfering can be selected as desired, but if the diameter of the conductor is d, then (1/2d)R or (1
/2d) It is preferable to carry out at C.

In the above description, the pole piece parts 13 and 13' were explained as being located approximately at the center of the width of the sliding surface 12, but as shown in FIGS. It is also possible to configure it so that it is offset to one side of the surface 12.

Next, a method of manufacturing a wire-wound thin film magnetic head according to the present invention will be explained.

FIG. 7 shows an embodiment of the method for manufacturing a thin film magnetic head according to the present invention. (a) In the step, a pair of non-magnetic substrates 2
and 2' are provided. A groove 10a is formed in the substrate 2. Among both side walls 10'a and 10''a of the groove 10a, at least the side wall adjacent to the end that will form the pole piece portion in the future, in this embodiment, the side wall 10'a is inclined toward the end. The substrates 2, 2' are made of a non-magnetic material, for example ceramic or glass.

In step (b), magnetic thin films 4, 4' are formed on the entire surface of the substrates 2, 2' by vapor deposition, electrodeposition, sputtering, or the like. Examples of magnetic thin film materials include permalloy and F.
Metal ferromagnetic materials such as e-Si-Ai alloy (Sendust) and Co-based amorphous are suitable. (c) Adhesive 5 made of glass, silver solder, resin, etc. is applied to the magnetic thin film portion provided on the sloped side wall 10'a of the groove 10a formed in the substrate 2 in the step in a manner that complements the sloped portion. will be placed.

The adhesive 5 also serves to reinforce the area from the pole piece to the winding of the magnetic head. Next, substrates 2 and 2'
The surfaces of the upper magnetic films 4, 4' and adhesive 5 are polished to provide a uniform plane. Next, in step (d),
A non-magnetic spacer film 6 is deposited on a portion of one of the magnetic thin films 4 or 4', which in this embodiment is to become a pole piece portion of the magnetic thin film 4 provided on the grooved substrate 2.
It is formed by electrodeposition, sputtering, etc. Alumina or the like is suitable as the material for the spacer film.

In the step (e), the substrates 2, 2' are coated with magnetic thin films 4, 4'.
are butted together so as to face each other, and are integrally joined using a well-known adhesive such as glass, silver solder, or resin. Head block 1 formed by joining
In step (f), grooves 20 are formed at equal intervals across the surface to become the pole piece portion, that is, the sliding surface, that is, in the direction perpendicular to the magnetic thin films 4, 4'. As can be more clearly understood with reference to FIG. 8, the shape of each groove 20 has a width W and a length L in the portion that becomes the pole piece portion of the magnetic thin films 4 and 4' by each adjacent groove 20. It is said to form a magnetic thin film. The depth T' of the leading edge of the groove 20 is equal to the adhesive placement depth T shown in FIG. 7(c).
be the same as or slightly smaller. Each groove 20 thus formed is then filled with a protective material 22 made of a non-magnetic material, such as glass, silver solder, or resin. In the next step (f), the protective material-filled portion of the head block 1A filled with the protective material, which becomes the pole piece portion, is polished to create a sliding surface 12 that comes into contact with a recording medium such as a tape.

Next, grooves 10 for winding are bored parallel to the magnetic thin films 4, 4' from the sliding surface side, and then sliced along the cutting line A-A' passing through the center position of each groove 20. A magnetic head chip (W') is cut out. In the step (h) of the magnetic head chip thus produced, each acute edge of the portion where the winding is to be applied is chamfered (4a, 10b). Next, such a magnetic head chip is wound with a wire so as to surround the magnetic film 4 in the groove 10 provided in the substrate 2 by a well-known method, and a wire-wound thin film magnetic film as shown in FIG. 2 is formed. Head 1 is produced. The diameter of the conducting wire used as the winding wire is preferably 0.01 to 0.1 mm.

In the above manufacturing method, in order to form the magnetic thin film 4 into a shape that gradually increases from the pole piece part 12 toward the winding part, after forming the head block 1A, the above formula w/g9<
Although this was done by drilling a roughly semicircular groove 20 that satisfies W/G, other methods are also possible. For example, as shown in FIG. 9, the magnetic thin films 4, 4' are formed on the substrates 2, 2' into a predetermined shape using patterning technology, that is, the magnetic thin films 4, 4' are formed from the pole piece part 12 to the winding part. The voids 2a and 2'a are filled with a filler such as glass, silver solder, or resin. It can also be configured as After that, a spacer film is provided on the portion corresponding to the pole piece part 12 of one of the magnetic thin films 4, 4', and then both substrates 2, 2' are arranged so that the magnetic thin films 4, 4' face each other. They are butted together and integrally joined using an adhesive such as glass, silver solder, or resin, and a sliding surface is immediately created by polishing.Subsequently, a magnetic head chip is cut out in the same manner as in the previous embodiment, and a thin film magnetic Heads can be made.

In the above description, the groove 10 is provided only in the substrate 2,
Then, winding was applied, but as shown in FIG. 10, grooves 10' can also be formed in the other substrate 2', and winding can be applied.

To the east, as shown in FIG.
The grooves 10 and 10' can be formed to have the same shape and windings can be applied to both grooves 10 and 10'. It will be understood that the thin film magnetic head illustrated in FIGS. 10 and 11 can be similarly manufactured by the manufacturing method described above.

Furthermore, in the magnetic head according to the present invention, the grooves 10 and 10' can be formed so as to be perpendicular to the magnetic thin films 4 and 4', as shown in FIGS. 12 to 14. Furthermore, the first
As shown in FIGS. 5 and 16, instead of the grooves 10, 10', a so-called convex head may be formed in which a notch 10'' is formed and the sliding surface 12 becomes narrower.

Since the present invention is configured as described above, it is possible to achieve the effects of improving winding efficiency and increasing reproduction output. Furthermore, the thin film magnetic head according to the present invention can be used as a narrow track head, and the mechanical strength and wear resistance of the pole piece portion can be greatly improved.

Further, according to the manufacturing method according to the present invention, wire-wound thin film magnetic heads can be manufactured in large quantities and quickly.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional wire-wound thin film magnetic head. FIG. 2 is a perspective view of a wire-wound thin film magnetic head according to the present invention. FIG. 3 is an exploded perspective view of the thin film magnetic head of FIG. 2, with the gear spacer film and windings omitted. FIG. 4 is a partially detailed vertical sectional view of the thin film magnetic head of FIG. 2. FIG. FIG. 5 is a perspective view showing another embodiment of the wire-wound thin film magnetic head according to the present invention. FIG. 6 is an exploded perspective view of the thin film magnetic head of FIG. 5, with the gear spacer film and windings omitted. FIGS. 7(a) to 7(h) are perspective views showing the manufacturing process of the wire-wound thin film magnetic head according to the present invention. FIG. 8 is a detailed cross-sectional view taken along line VIII-VIII of FIG. 7(f). FIG. 9 is a perspective view illustrating another embodiment of the manufacturing method of the wire-wound thin film magnetic head according to the present invention. 10 to 16 are perspective views showing other embodiments of the wire-wound thin film magnetic head according to the present invention. 1: Wire-wound thin film magnetic head 2, 2': Non-magnetic substrate 4, 4': Magnetic thin film 4a, 10b: Chamfered portion 6: Gear spacer film 8, 8': Winding 10, 10', 10a: Groove 10'': Notch 12: Sliding surface 13, 13': Name of pole piece department representative Motoi Kurauchi Hirodo Kurahashi Akite Tsuzuki Sleeve tl, i -r': C method) 1981 3 no] 241" Special i Display of 'i'l agency official Wakasugi Kazuten incident
1981 Patent Application No. 197810 Name of the invention
Wire-wound thin film 6. Relation to the Ministry's case for amending the air head and its manufacturing method Name of patent applicant 1
”Hon Mining Forestry Company Agent Telephone: 273-6436 Funoma
-Address
” - Name (7563) Patent attorney Akira Kurahashi (・2. Notification of Kabu, Ouramasa's order 1 attached February 22, 1988 - Supplementary iH Motori 1
Soka→=The present invention-0 number--r\Object of Sodeichi ■Correct content As shown in the attached sheet (-) "Drawing" is corrected as follows. Regarding Figures 7(d) to (g) and (h) submitted earlier,
J: Sea urchin drawing number “7th
Describe the figure. 11

Claims (1)

[Claims] 1) A pole piece formed by a pair of non-magnetic substrates facing each other, magnetic thin films provided on opposing surfaces of each substrate, and abutment of both magnetic thin films. a non-magnetic spacer film that fills a gap between the two substrates, and a winding wound around a magnetic thin film on the substrate in a groove formed in at least one of the substrates; 1. A wire-wound thin film magnetic head, characterized in that the thin film is formed so that its width increases from the pole piece portion toward the winding portion. 2) The edges of the magnetic thin film in the winding section are chamfered! A wire-wound thin film magnetic head according to claim 1. 3) A wire-wound thin film magnetic head according to claim 2, wherein the edge of the groove of the substrate is chamfered. 4) The wire-wound thin film magnetic head according to claim 1, wherein the width (W') of the winding portion of the magnetic thin film is five times or more the width (w) of the pole piece type. 5) Width (w) of the pole bead part of the magnetic thin film, width (W) of the magnetic thin film from the rear of the pole piece part to the winding part (including the winding part), and the pole between both magnetic thin films. Between the gap size (g) in the piece part and the gap size (G) in the winding part between both magnetic thin films at the position of the magnetic thin film width (W), g/w<G/W. 5. A wire-wound thin film magnetic head according to claim 4, which is configured such that a relationship is established. 6) A wire-wound thin film magnetic head according to claim 1, wherein the thickness of the magnetic thin film is constant. 7) The wire-wound thin film magnetic head according to claim 1, wherein the thickness of the magnetic thin film is formed so as to gradually increase from the pole piece portion toward the winding portion. 8) Providing a pair of non-magnetic substrates each having a groove on at least one of the substrates, the wall portion of the groove adjacent to the pole piece forming end being inclined toward the pole piece forming end; forming a magnetic thin film on opposing surfaces of each of the substrates; filling the sloped portion of the magnetic thin film portion provided on the sloped wall of the groove portion with an adhesive so as to complement the sloped portion; A step of polishing the surface of the magnetic thin film on the substrate to make it flat; a step of forming a non-magnetic gear spacer film on a portion corresponding to the pole piece portion of at least one of the magnetic thin films; a step of forming the two substrates so that the magnetic thin films face each other; a step of butting and joining them together to form a headblock; a step of drilling a groove across the pole piece portion of the headblock in a direction perpendicular to the magnetic thin film; a step of filling the groove with a non-magnetic protective material. a step of polishing the sliding surface of the headblock, including the pole piece portion, into a predetermined shape;
A wire-wound thin film magnetic head comprising the steps of: slicing the head block to a predetermined width to cut out a head chip; and winding a conductive wire around the winding portion of the head chip so as to surround a magnetic thin film on the substrate. manufacturing method. 9) Prior to cutting out the individual head chips, grooves or notches are formed along the magnetic thin film in at least the grooved substrate of the headblock in order to cooperate with the grooves to form the windings; 9. The method of manufacturing a wire-wound thin film magnetic head according to claim 8, wherein the acute edge of the winding portion of each individually cut out head chip is chamfered prior to winding. 10) Providing a pair of non-magnetic substrates each having a groove on at least one of the substrates; forming a magnetic thin film in a predetermined shape on opposing surfaces of each substrate; forming a magnetic thin film on each substrate surface; A step of filling an empty gap with a non-magnetic filler; a step of forming a non-magnetic gear spacer film in a portion corresponding to the pole piece portion of at least one of the magnetic thin films; a step of forming the two substrates so that the magnetic thin films face each other; a step of butting and joining together to form a headblock; a step of polishing the sliding surface of the headblock including the pole piece portion into a predetermined shape; a step of slicing the headblock to a predetermined width and cutting out a head chip; and a step of cutting out the head chip. 1. A method of manufacturing a wire-wound thin film magnetic head, comprising the step of winding a conductive wire in a substrate groove so as to surround a magnetic thin film on the substrate. 11) Prior to cutting out individual head chips, grooves or notches are formed along the magnetic thin film in at least the grooved substrate of the headblock in order to cooperate with the grooves to form the windings, and 11. The method of manufacturing a wire-wound thin film magnetic head according to claim 10, wherein the acute edge of the winding portion of each individually cut out head chip is chamfered prior to winding.