JPH08102003A - Method of manufacturing magnetic head - Google Patents

Abstract

PURPOSE: To greatly improve the reliability of products by drastically decreasing the number of retries at the time of adhering head chips and easily improving the accuracy of the differences in level between tracks in the respective head chips. CONSTITUTION: Magnetic core blocks 1, 2 subjected to cylindrical polishing are installed at a jig 12 and the one-side ends of the arbitrary track width of the magnetic core blocks 1, 2 are positioned and fixed to each other. The blocks are cut out by each of respectively one set of the head chips 4a, 4b and are adhered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetic head, for example, a method for processing a sliding surface of a magnetic recording medium of a magnetic head mounted on a VTR (video tape recorder).

[0002]

2. Description of the Related Art Usually, in the manufacturing process of a rotary magnetic head mounted on a VTR, a cylindrical grinding process (also called R process) for smoothly grinding a sliding surface of a magnetic recording medium into an arc shape is performed. Be seen. Generally, as the recording modes in the VTR, there are provided two kinds of modes, a standard time recording mode (SP mode) and a triple time recording mode (EP mode). Therefore, such V
In the rotary magnetic head mounted on the TR, two SP mode magnetic heads and two EP mode magnetic heads are provided on the rotary drum. At this time, one of the SP mode magnetic head and the EP mode magnetic head are installed on a single head base plate (head base) with a predetermined gap distance therebetween to form a so-called double azimuth head. It is necessary.

Conventionally, as a method of manufacturing the above-mentioned double azimuth head, first, as shown in FIG. 9, a pair of magnetic core block halves 101 and 102 for SP mode are butted against each other via a gap material and joined together. Then, the SP mode magnetic core block 103 is manufactured and fixed to the jig 111. Similarly, a pair of magnetic core blocks for EP mode are butted against each other via a gap material, joined and integrated to manufacture a magnetic head block for EP mode (all are not shown), and fixed to a jig. .

Next, as shown in FIG. 10, this SP mode magnetic core block 103 is installed in a jig, and a cylindrical grinder is used to set the center position of a predetermined gap distance to be described later to the apex of cylindrical grinding. The magnetic core block 103 is ground while displacing the center of the cylindrical grinder so that the magnetic recording medium sliding surface is subjected to cylindrical grinding in an amount half that of normal cylindrical grinding. Similarly, the above E
The magnetic core block for P mode is installed on a jig so that the center position of a predetermined gap distance to be described later with respect to the magnetic head core 103 for SP mode becomes the apex of cylindrical grinding (however, it is symmetrical with the magnetic core block 103). The magnetic recording medium sliding surface of the EP mode magnetic core block is subjected to the above-mentioned cylindrical grinding.

Thereafter, as shown in FIG. 11, each of the SP mode magnetic core blocks 103 is formed by using a single blade grindstone or a plurality of continuous grindstones so that the ground surface thereof has an angle corresponding to a required azimuth angle. Each head chip 104 is cut. Similarly, the magnetic core block for the EP mode is also cut at each head chip with an angle corresponding to the required azimuth angle.

Then, the SP mode head chip 104 manufactured as described above and the EP mode head chip are separated from each other by a predetermined gap distance and bonded and fixed to the same head substrate (head base). Then, the double azimuth head is completed through post-processes such as tape wrap and winding of these two types of head chips.

[0007]

As described above, the double azimuth head is composed of SP mode and EP mode head chips. In this double azimuth head, S having almost the same track height, that is, there is almost no step difference between the two tracks.
It is necessary to configure each head chip for P mode and EP mode.

Conventionally, as described above, for SP mode and E
From the magnetic core block for P mode to SP mode and E
The head chips for the P mode are cut so that each track has a prescribed track height. Therefore, in order to manufacture a double azimuth head with a small step difference between tracks, it is necessary to classify the cut-out head chips for each mode using a microscope and pair them for each set of head chips with almost the same track height. There is. Therefore, the number of inspection steps and the number of retries at the time of head chip adhesion are increased, which is a serious problem in terms of workability.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetic head in which two types of head chips are symmetrically arranged with a predetermined gap distance. , The number of retries at the time of head chip bonding can be significantly reduced, the accuracy of the step difference between tracks between the head chips can be easily improved, and the reliability of the magnetic head can be greatly improved. It is to provide a manufacturing method.

[0010]

SUMMARY OF THE INVENTION The present invention is directed to a method of manufacturing a magnetic head in which a set of head chips each having a predetermined magnetic gap has a predetermined azimuth angle. is there. In the present invention, the manufactured magnetic head is mainly mounted on a video tape recorder, and one set of head chips is mainly used for the standard time recording mode and the triple time recording mode, respectively. I will handle it.

That is, according to the present invention, a pair of magnetic core blocks each having a plurality of magnetic gaps each having a cylindrical surface and having a plurality of magnetic gaps formed at the same pitch are tilted to each other according to a prescribed azimuth angle. A pair of magnetic core blocks at the same time; a step of installing on a jig having a surface, a step of positioning and fixing one end portions of an arbitrary track width of a pair of magnetic core blocks in the state of being installed on the jig. A step of cutting each head chip into a predetermined chip width,
The magnetic head is manufactured by going through a step of adhering a set of cut head chips to the same head substrate so as to oppose each other with a predetermined gap distance.

Further, when performing the cylindrical grinding on the ground surfaces of the pair of magnetic core blocks, the pair of magnetic core blocks are fixed so as to face each other with a predetermined gap distance, and the ground surfaces of the pair of magnetic core blocks are fixed. It is desirable to simultaneously perform cylindrical grinding with the center position of the gap distance as the apex.

[0013]

In the method of manufacturing a magnetic head according to the present invention, one end of an arbitrary track width is positioned and fixed to a jig having a butting surface that is inclined with respect to a specified azimuth angle, and a plurality of jigs are provided. A pair of magnetic core blocks in which the magnetic gaps are formed at the same pitch are installed, and a set of head chips are simultaneously cut out to a predetermined chip width from the pair of magnetic core blocks. That is, in order to cut each set of head chips in a state where the track heights of the pair of magnetic core blocks are aligned, each set of cut head chips has almost no step difference between tracks. Become. Therefore, a set of head chips with extremely high accuracy of step difference between tracks can be manufactured very easily and efficiently.

By magnetically adhering and fixing this set of head chips to the same head substrate with a predetermined gap distance, a magnetic head having an extremely small step difference between tracks is produced, and each produced magnetic head is produced. The variation in the step difference between tracks for each magnetic head is reduced. Further, in the present invention, when performing the cylindrical grinding on the grinding surfaces of the pair of magnetic core blocks, the pair of magnetic core blocks are fixed so as to face each other with a predetermined gap distance, and the pair of magnetic core blocks are ground. Since the surfaces are simultaneously cylindrically ground with the center position of the gap distance as the apex, the entire ground surfaces of both magnetic core blocks are uniformly processed into a cylindrical shape. Therefore, the contact characteristic of the product with respect to the magnetic recording medium is improved, spacing loss is prevented, and S /
N is improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method of manufacturing a magnetic head according to the present invention will be described below with reference to the drawings. The magnetic head manufacturing method according to the present embodiment is composed of head chips for SP mode and EP mode in order to support a video tape recorder equipped with two recording modes of SP mode and EP mode. This method is suitable for producing a so-called double azimuth head.

In order to manufacture the above-mentioned magnetic head, first, a pair of magnetic core block halves 1a and 1b are butted against each other with a gap material therebetween, and they are joined and integrated with each other by using a fused glass to form S.
The first magnetic core block 1 for P mode is manufactured. Similarly, a pair of magnetic core block halves 2a and 2b are butted against each other via a gap material and joined together to produce a second magnetic core block 2 for EP mode. Here, winding grooves 1c and 2c for winding are respectively formed in the magnetic core block halves 1a and 2a.

At this time, each magnetic core block 1, 2
As shown in FIG. 1, the track widths of the plurality of magnetic gaps g1 and g2 are the same pitch, that is, the pitch P1 of the magnetic core block 1 and the pitch P2 of the magnetic core block 2.
Must be formed equally. Next, FIG.
As shown in, the first magnetic core block 1 and the second magnetic core block 2 are separated by a predetermined gap distance (from the magnetic gap g1 of the magnetic core block 1 to the magnetic core block 2).
The magnetic gap g2 is fixed to the jig 11 with an adhesive or the like in a state of being separated and abutted with each other by a predetermined distance in the facing direction.

After that, as shown in FIG. 3, a cylindrical shape (R shape) is formed with the apex at the center position of the predetermined gap distance with respect to the grinding surface 3 of the upper surface of the magnetic core blocks 1 and 2. As described above, cylindrical grinding is performed using a cylindrical grinding machine. At this time, the grinding surface 3 is ground into a uniform cylindrical shape while applying a required swing to the magnetic core blocks 1 and 2.
Thus, in this embodiment, the entire ground surface 3 of both magnetic core blocks 1 and 2 is uniformly processed into a cylindrical shape. Therefore, the contact property of the product with respect to the magnetic recording medium is improved, spacing loss is prevented, and S / N is improved.

In particular, as shown in FIG. 4, the cylindrically ground magnetic core blocks 1 and 2 are installed on a jig 12 (indicated by double-hatched lines in the drawing). This jig 12 is S
Specified azimuth angle θ1 for P mode and EP mode
The abutting surfaces 12a and 12 that are inclined to each other according to θ2
It has a structure with b, and has a substantially wedge shape. By installing the magnetic core blocks 1 and 2 on the mating surfaces 12a and 12b of the jig 12, respectively, each grinding surface 3a has a desired azimuth angle. When the video tape as a magnetic recording medium is for so-called VHS, both azimuth angles θ1 and θ2 are 6 °, and for 8 mm, both are 10 °.

In this state, that is, in the state where the pair of magnetic core blocks 1 and 2 are in contact with the side surface portions 12a and 12b of the jig 12, one end portion of the magnetic core blocks 1 and 2 having an arbitrary track width is positioned. Fix it. That is, as shown in FIG. 5, the magnetic gaps g1 and g2 at the left ends of the magnetic core blocks 1 and 2 are focused here, and one end portions 13 and 14 of these track widths are line segments aa in the figure. ', And in this state, the magnetic core blocks 1 and 2 are fixed to the mating surfaces 12a and 12b of the jig 12 using an adhesive or the like.

After that, the pair of magnetic core blocks 1 and 2 are simultaneously cut along the respective one-dot chain lines L, so that each set of head chips 4 having a predetermined chip width s shown by diagonal lines in the drawing.
It will be cut out every a and 4b. As described above, in the present embodiment, as shown in FIG. 6, a set of head chips 4a and 4b is provided in a state where the track heights h1 and h2 of the pair of magnetic core blocks 1 and 2 are substantially aligned (almost equal). In order to cut each of the head chips 4a and 4b, the cut head chips 4a and 4b are separated by a step d (= | h1−
It has almost no h2 |). Therefore, a pair of head chips 4a and 4b with extremely high accuracy of step difference between tracks can be manufactured very easily and efficiently.

A set of head chips 4 shown in FIG.
As shown in FIG. 8, a and 4b are separated from each other by the predetermined gap distance and bonded and fixed to the head substrate (head base) 5. Then, the double azimuth head 4 having a very small track-to-track step d is completed through post-processes such as winding and inspection of the first and second head chips 4a and 4b fixed to the head base 5. Then, the head substrate 5 on which the double azimuth head 4 is installed is mounted on the rotary drum 6.

The variation in the level difference between tracks of each double azimuth head 4 manufactured as described above is extremely small, and compared with that of each double azimuth head manufactured by the conventional method, the above-mentioned conventional dispersion is dispersed. While the value σ was 2.3 μm, the dispersion value σ of the above-mentioned variation of the double azimuth head 4 was 1.2 μm, which was about half the value.

The present invention is not limited to the above embodiment, and for example, when the magnetic core blocks 1 and 2 are manufactured, the track width for SP mode and the track width for EP mode are alternately formed. Then, a double azimuth head may be manufactured in the same manner as in the above embodiment.

[0025]

As is apparent from the above description, according to the method of manufacturing a magnetic head of the present invention, a magnetic head in which two types of head chips are symmetrically arranged with a predetermined gap distance is provided. The number of retries at the time of head chip bonding can be greatly reduced, the accuracy of the step difference between tracks between each head chip can be easily improved, and the product reliability can be greatly improved. Becomes

[Brief description of drawings]

FIG. 1 is a plan view schematically showing a pair of magnetic core blocks formed so that the pitches of their respective track widths are equal.

FIG. 2 is a perspective view schematically showing a state in which a pair of magnetic core blocks are separated by a predetermined gap distance and fixed to a jig.

FIG. 3 is a perspective view schematically showing a state where predetermined grinding is performed on the grinding surfaces of a pair of magnetic core blocks fixed to a jig.

FIG. 4 is a plan view schematically showing a state in which a pair of magnetic core blocks subjected to cylindrical grinding are installed on a jig.

FIG. 5 is a plan view schematically showing a state in which one ends of the track width of a pair of magnetic core blocks are positioned and fixed to each other.

FIG. 6 is a plan view schematically showing a set of head chips cut out from a pair of magnetic core blocks.

FIG. 7 is a perspective view schematically showing a set of head chips cut out from a pair of magnetic core blocks.

FIG. 8 is a side view showing a state in which the magnetic head manufactured in the above example is mounted on the head base.

FIG. 9 is a perspective view schematically showing how an SP mode or EP mode magnetic core block is installed in a jig in a conventional magnetic head manufacturing method.

FIG. 10 shows an SP in a conventional magnetic head manufacturing method.
FIG. 6 is a perspective view schematically showing a state where the grinding portion of the magnetic core block for mode or EP mode has been subjected to half the usual cylindrical grinding.

FIG. 11 is a perspective view schematically showing a head chip cut out from a magnetic core block in a conventional method of manufacturing a magnetic head.

[Explanation of symbols]

 1 Magnetic core block for SP mode 2 Magnetic core block for EP mode 3 Grinding surface 4 Double azimuth head 4a, 4b One set of head chip 5 Head substrate 11, 12 Jig 12a, 12b mating surface

Claims (3)

[Claims] 1. A pair of magnetic core blocks, each of which has a plurality of magnetic gaps formed by cylindrical grinding on the ground surface and formed at the same pitch, and has an abutting surface inclined to each other according to a prescribed azimuth angle. A step of installing on a jig, a step of positioning and fixing one end portions of an arbitrary track width of a pair of magnetic core blocks in the state of being installed on the jig, and a set of head chips simultaneously from a pair of magnetic core blocks And a step of adhering a set of the cut head chips to the same head substrate so as to face each other with a predetermined gap distance, Manufacturing method. 2. A pair of magnetic core blocks are fixed so as to face each other with a predetermined gap distance, and the grinding surfaces of the pair of magnetic core blocks are simultaneously cylindrically ground with the center position of the gap distance as the apex. The method of manufacturing a magnetic head according to claim 1, wherein: 3. The manufactured magnetic head is mounted on a video tape recorder, and a set of head chips is for a standard time recording mode and a triple time recording mode, respectively. The method of manufacturing a magnetic head according to claim 1.