JPH08185606A - Magnetic head and its production - Google Patents

Abstract

PURPOSE: To eliminate the need for precision working, etc., and to provided a magnetic head having excellent wear resistance by butting a pair of core base materials formed with magnetic metallic films on their butt surfaces against each other and joining these core base materials to each other in this state by adhesive glass. CONSTITUTION: The magnetic metallic films 2L, 2R consisting of Fe-Al-Si alloys are respectively formed on the butt surfaces of a pair of the core base materials 1A, 1B formed of, for example, Nn-Zn ferrite, etc., to a U shape in section. These butt surfaces are butted against each other via gap materials 1c and both core base materials 1A, 1B are joined by using the adhesive glass 3. Many track forming grooves 6L, 6R of a specified pitch arriving at the gap part 1c from the outer side faces of the respective core base materials 1A, 1B are thereafter cut down to the surfaces corresponding to a tape sliding part 1a of the core base materials 1A, 1B. Gap parts 1c of each of respective chips are formed by these track forming grooves 6L, 6R, by which the track width of the gap parts 1c is limited to the regulated size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used for a rotary head of a video tape recorder or a digital audio tape recorder, and more particularly to a method of manufacturing the same and a magnetic head obtained by the method.

[0002]

2. Description of the Related Art As is well known, a magnetic head A as shown in FIGS. 11 and 12 is used in a rotary head of a video tape recorder or a digital audio tape recorder. Thus, for example Mn-Zn ferrite or the like a pair of core blocks B _L made with, the abutting surface of B _R, for example, Fe-Al-Si comprising an alloy metal magnetic film C _L, C _R
After the film is formed, the recording / reading coil E is wound around the coil winding portion B ₁ after being bonded to each other with the adhesive glass D, but the running direction of the magnetic tape (not shown) is on the upper end surface thereof. The tape sliding portion B ₂ extended to the end is projected. That is, the gap material F is provided at the center of the tape sliding portion B _2.
Are formed interposed gap-unit B ₃ a, the tape sliding portion B ₂ in order to maintain the adhesion and mechanical strength with respect to the magnetic tape, a large tape than the track width L ₁ of the gap portion B ₃ It has a contact width L ₂ .

By the way, the above-mentioned conventional magnetic head is
It is usually manufactured by the manufacturing process as shown in FIGS. That is, as shown in FIG. 8, the abutting surfaces of the pair of core base materials b _L and b _R having the “U” -shaped cross section have vertical directions adjacent to each other in the longitudinal direction of the core base materials b _L and b _R. number after the track grooves G are formed of a metal magnetic film C _L, it is C _R is formed in the abutting surfaces. Then, as shown in FIG.
Both core base materials b _L and b _R are adhered to each other by the adhesive glass D. In this case, the adhesive glass D is also filled inside the track groove G so that the track groove G is in a blind state.

[0004] Further, the core preform b _L, on the upper surface of the b _R, a plurality of step groove H is the core preform b _L a pitch corresponding to the track grooves G, in a direction perpendicular to the abutting surface of the b _R The tape slide portion B _{2 which} is processed in the extended state and has a protruding portion with a gap portion B ₃ is left by the step groove H, and the core base material b _L , which is parallel to each step groove H and has a predetermined core chip thickness, FIG. 11 is obtained by slicing b _R.
Magnetic head A is completed.

[0005]

Therefore, in the magnetic head A manufactured by such a manufacturing process, the core base materials b _L and b _R are joined while being displaced in the length direction, or the track groove G has a pitch error. When there is or machining errors, the gap portion B ₃ in the magnetic head a, as shown in FIG. 12, the core block B _L, the state was "offset" in the thickness direction of B _R. That is,
Left and right core block B _L, the track deviation δ is generated in the gap portion B ₃ of B _R, because the boundary portion of the recording pattern on the magnetic tape becomes unclear state, dense magnetic recording becomes difficult.

Therefore, conventionally, a magnetic head A which does not cause the track deviation δ as shown in FIG. 15 has been proposed. That is, as shown in FIG. 13, this magnetic head A has a plurality of track grooves G ₁ wider than the above-mentioned track groove G on the gap side surface of the core base materials b _L and b _R manufactured in the state of FIG. by processing, limiting the track width, after filling anew each track grooves G filling glass I, these filled glass I form cutting in step groove G ₂ is the state of FIG. 14, step groove G ₂ The magnetic head A ₁ as shown in FIG. 15 is obtained by slicing in the direction parallel to.

Therefore, also in the magnetic head A having such a structure, a tape sliding portion B ₂ having a required tape contact width L ₂ reinforced by the filling glass I is obtained, and the gap portion is formed by processing the primary track groove G. The track width L _{1 of} B ₃ is limited and the track shift δ is prevented. However, in the magnetic head A having such a structure, since the filled glass I having poor wear resistance is exposed on the tape sliding surface, the filled glass I may be worn early at the time of use and may not be usable. There is a problem in practical application. In view of the problems of the conventional magnetic head as described above, the first object of the present invention is to obtain a magnetic head having a structure with excellent wear resistance without the risk of causing track deviation. To obtain a manufacturing method of. A second object of the present invention is to obtain a practical magnetic head that is free from track deviation and has excellent wear resistance.

[0008]

According to the present invention, the above-mentioned first object is to provide a pair of "U" -shaped core blocks with a metal magnetic film formed on the abutting surfaces of the core blocks in the abutting state. In a magnetic head that joins blocks with adhesive glass and forms a gap on the tape sliding surface of the tape sliding portion that is made to protrude by forming a step groove, a pair of core base materials with a metal magnetic film formed on the abutting surfaces A step of joining with adhesive glass in a butt state, and forming a prescribed track width by cutting a number of track forming grooves with a constant pitch from the outer surface of each core base material to the gap portion on the tape sliding portion corresponding surface And a step of filling the track forming grooves with a filling glass, and a plurality of steps on the surfaces of the core base materials corresponding to the gaps in a direction orthogonal to the abutting surface. A step of projecting the tape sliding portion to form a groove, parallel to the step groove is accomplished by providing a step of slicing a given core chip thickness. Further, in a preferred embodiment of the present invention described later, the track forming groove is described as a groove having an angle with the slice direction parallel to the step groove. According to the present invention, the above-mentioned second object can be achieved by the magnetic head obtained by the method of manufacturing a magnetic head capable of achieving the first object.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the embodiments of the present invention will be described below with reference to FIGS. 1 to 6 show a magnetic head according to a first embodiment of the present invention, and in particular, FIGS. 1 and 2 show a completed magnetic head.

That is, in the magnetic head X shown in FIGS. 1 and 2, metal magnetic films 2L and 2R are formed on the abutting surfaces of a pair of "U" -shaped core blocks 1L and 1R, and the magnetic heads are in an abutting state. The core blocks 1L and 1R are bonded to glass 3
And a gap portion 1c is formed on the tape sliding surface 1b of the tape sliding portion 1a that is projected by forming a step groove, which will be described later. The gap portion is located at the center of the tape sliding surface 1b. The track width L ₁ of 1c is characterized in that it is limited by the filling glasses 4L and 4R located on both sides of the same gap portion 1c. That is, the entire tape sliding surface 1b with which the magnetic tape slides contacts the core blocks 1L, 1R.
Of the tape sliding portion 1a having abrasion resistance, and the filling glasses 4L and 4R are exposed only on a part of both sides of the gap portion 1c.
The recording / reading coil 5 is wound around d.

3 to 6 show a manufacturing process of the magnetic head X according to the first embodiment of the present invention. For example, a pair of core base materials 1A, which are formed of Mn-Zn ferrite or the like in a "U" -shaped cross section, On the butt surface of 1B, for example, Fe-Al-S
Metal magnetic films 2L and 2R made of an i alloy are respectively formed, and their abutting surfaces are abutted in the direction of the arrow in FIG. 3 (a gap material is interposed in this step),
Both core base materials 1A and 1B are joined using the adhesive glass 3 of FIG. 4 while maintaining the same butted state.

Thereafter, in the present invention, each core base material 1
For A and 1B, a large number of track forming grooves 6L and 6R with a constant pitch reaching the gap portion 1c from the outer surface of each core base material 1A and 1B are cut into the surface corresponding to the tape sliding portion 1a. The track forming grooves 6L and 6R form the gap portion 1c for each chip, and the track width L ₁ of the gap portion 1c is limited to a prescribed dimension. In the case of the first embodiment, the direction of each of the track forming grooves 6L and 6R when viewed from above is such that the core base materials 1A and 1B to be described later are arranged.
Is selected from those having an inclination angle θ ₁ of 0 to 30 degrees, preferably 5 to 20 degrees with respect to the slice line, that is, the plane perpendicular to the length direction of the core preforms 1A and 1B. The reason for this is to minimize the exposure of the below-described filling glasses 4L and 4R to the tape sliding surface 1b with which the magnetic tape is in sliding contact.

Further, these track forming grooves 6L, 6R
Has a drive-in angle θ ₂ with respect to a horizontal plane, and the drive-in angle θ ₂ is in the range of 1 to 45 degrees, preferably 5 to 20 degrees. That is, by giving the drive-in angle θ ₂ to each track forming groove 6L, 6R, the gap portion 1c in the height direction of each chip can be completely separated, and the gap portion 1c having a high magnetic flux density can be obtained. it can.

After the track forming grooves 6L and 6R are formed on the core base materials 1A and 1B at a constant pitch, the track forming grooves 6L and 6R are filled with glass 4L and 4R.
Are filled and fixed, and as shown in FIG. 5, the track forming grooves 6L and 6R are filled with the filling glasses 4L and 4R, and the entire outer surface shape is returned to a square bar shape.

After the glass filling step, a plurality of step grooves 7 having a constant pitch are formed on the surfaces of the core base materials 1A and 1B corresponding to the gap portion 1c, and the gap portion 1c is formed as shown in FIG. The tape sliding portion 1a is projected. That is, these step grooves 7 are formed in the gap portion 1
Since the core base materials 1A and 1B extend in the abutting direction at a position not corresponding to c, the track forming grooves 6L and 6R are inclined with respect to the step grooves 7, and are shown enlarged in FIG. Thus, the tips of the filling glasses 4L and 4R are slightly exposed on both sides of each gap 1c.

Therefore, the core preforms 1A and 1B joined together by the adhesive glass 3 are parallel to the step groove 7, and along the plane perpendicular to the longitudinal direction of the core preforms 1A and 1B, that is, the slice line, The magnetic head X shown in FIG. 1 can be completed by slicing with a predetermined core chip thickness.

The manufacturing process of the magnetic head X according to the first embodiment is as described above. Therefore, when compared with the conventional manufacturing process described above with reference to FIGS. Since no special alignment work is required and the conventional work for processing the track grooves formed in each core base material can be omitted, the number of steps can be reduced and the manufacturing cost can be reduced.

Further, in the magnetic head X obtained in the manufacturing process of the first embodiment, the track width L ₁ of the gap portion 1c is strictly defined in the process of cutting the track forming grooves 6L, 6R. Therefore, the structure has a clear edge of the gap portion 1c and is suitable for high-density recording. Further, the entire tape sliding surface 1b of the magnetic head X is composed of the ferrite of the core blocks 1L and 1R, and only the filling glasses 4L and 4R are exposed to a very small portion, so that the tape sliding surface 1b is wear-resistant. It has excellent properties and the contact state with the magnetic tape is the same as before.

FIG. 7 is a perspective view of a magnetic head X ₁ according to a second embodiment of the present invention, which corresponds to FIG. _{1. In} the case of the magnetic head X ₁ of this embodiment, the tilt angle θ ₁ described in the first embodiment is the same. It is set to "0". That is, the tape sliding surface 1 of the magnetic head X ₁
Since only a pair of filled glasses 4L and 4R extending in the lengthwise direction of the tape sliding portion 1a are exposed at b, the abrasion resistance is much higher than that of the magnetic head shown in FIG. A flexible structure can be obtained.

[0020]

As is apparent from the above description, the method of manufacturing a magnetic head according to the present invention does not require strict positioning and precise processing, and has a small number of steps as compared with the conventional method. The track width of the gap portion of the obtained magnetic head becomes strict, and the structure has a practically excellent abrasion resistance.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a magnetic head obtained according to a first embodiment of the present invention.

FIG. 2 is an enlarged plan view of an essential part of the magnetic head.

FIG. 3 is an explanatory diagram of a butting process in the manufacturing process according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of a track forming groove processing step in the same manufacturing step.

FIG. 5 is an explanatory diagram of a glass filling step of the manufacturing process.

FIG. 6 is an enlarged explanatory view of a step groove processing step of the manufacturing process.

FIG. 7 is a perspective view corresponding to FIG. 1 of a magnetic head obtained according to a second embodiment of the present invention.

FIG. 8 is an explanatory diagram of a butting process in a conventional manufacturing process.

FIG. 9 is an explanatory diagram of a glass bonding step in the same manufacturing process.

FIG. 10 is an explanatory diagram of a step groove processing step in the manufacturing process.

FIG. 11 is an overall perspective view of a magnetic head obtained in the same manufacturing process.

FIG. 12 is an enlarged perspective view of a main part of the magnetic head.

FIG. 13 is an explanatory diagram of a track forming process in another conventional manufacturing process.

FIG. 14 is an explanatory diagram of a step groove processing step in the manufacturing process.

FIG. 15 is an overall perspective view of a magnetic head obtained by the manufacturing process.

[Explanation of symbols]

X, X ₁ Magnetic head θ ₁ Tilt angle θ ₂ Drive-in angle L ₁ Track width L ₂ Width per tape 1L, 1R Core block 1A, 1B Core base material 2L, 2R Metal magnetic film 3 Adhesive glass 4L, 4R Filled glass 5 Recording・ Reading coil 6L, 6R Track forming groove 7 Step groove

Claims (3)

[Claims] 1. A tape slide in which a metal magnetic film is formed on the abutting surfaces of a pair of "U" -shaped core blocks, the core blocks in the abutting state are joined by adhesive glass, and the protrusions are formed by forming step grooves. In a magnetic head in which a gap is formed on the tape sliding surface of the moving part, a step of joining a pair of core base materials with a metal magnetic film formed on the abutting surfaces in abutting state with adhesive glass, and the outer surface of each core base material From a plurality of track forming grooves having a constant pitch reaching the gap portion to form a specified track width on the tape sliding surface; and a step of filling the track forming grooves with a filling glass, Forming a plurality of step grooves on the surfaces of both core base materials corresponding to the gap portions in a direction orthogonal to the abutting surface to project the tape sliding portion; And a step of slicing to a predetermined core chip thickness parallel to the groove. 2. The method of manufacturing a magnetic head according to claim 1, wherein the track forming groove is a groove having an angle with respect to the slice direction parallel to the step groove. 3. A magnetic head in which a recording / reading coil is wound around a coil winding portion on the side opposite to the gap portion of the core block obtained in the slicing step according to claim 1 or 2.