JPS62159311A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic head which has precise track width accuracy and is excellent in wear resisting property and head characteristics, by forming the magnetic core in such a way that both magnetic core half mirrors are heated under a condition where they are pressure-contacted with each other and joined together above and below their winding windows. CONSTITUTION:A face 11 of the 1st magnetic core half body 10 made of a Mn-Zn ferrite is lapped to a mirror surface and the groove 12 of a depth G and width W which are equal to a desired gap length is formed in a part of the lapped surface 11 by chemical etching. Then a gap material 13 is formed by depositing a high-melting point nonmagnetic material, such as SiO2, etc., in the groove 12 to a thickness which is equal to or a little thicker than the depth G of the groove 12 by sputtering, etc. Then a winding window 16 is formed in the 2nd magnetic core half body 14 and the surface 15 in which the winding window 16 is formed is lapped to a mirror surface. The mirror surfaces 11 and 15 of the magnetic core half bodies 10 and 14 are allowed to contact with each other and heated at about 1,300 deg.C in N2 atmosphere while a pressure is applied in the direction shown by the arrow B. Finally, a groove 20 is formed in the upper section of the magnetic core formed with a magnetic gap.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a magnetic head for recording and reproducing signals on a magnetic recording medium such as a magnetic tape.

Conventional technology As the recording density of magnetic recording progresses, the effective track width also becomes extremely narrow, and for 8mm video it is 10μ.
It has reached m. FIG. 8 shows an example of a conventional magnetic head structure having such a narrow track. Here, a magnetic core half body 131 made of ferrite
．． A part of 132 is cut out to have a track width T by cutting to form magnetic cores PL and P2, and a thin film layer of a non-magnetic material such as Sio is formed between the magnetic cores P□ p2 to form one magnetic core. A gap 133 is formed by joining the core halves 131 and 132 through the thin film layer, and in this way a narrow track head is obtained. In addition,
134 is a glass for joining the magnetic core halves 131 and 132. In this case, wear resistance is imparted by making the width W of the portion of the sliding surface A away from the gap 133 sufficiently larger than the track width T.

In addition, as another conventional example, as shown in FIG. 9, a gap 137 is formed by a pair of magnetic cores 135, 136, and both cores 135, 136 are wrapped by lapping one surface.
There is also a structure in which the abutting portions of the cores 135 and 136 are finished without slipping, and side plates 138 and 139 made of a wear-resistant material are bonded to both sides of the cores 135 and 136. Note that when the side plates 138 and 139 are made of a magnetic material such as ferrite, the portion 1 adjacent to the gap 137
40 is filled with a non-magnetic material such as glass.

As another conventional example, as shown in FIG. 11, S
A long gap bar having a gap 144 is formed by forming a thin film layer of iO□, and a track of width T is formed by sequentially forming grooves 145 on the surface having the gap 144. There is also a method of making a head chip by melting and filling the glass 146 and then cutting it at the dotted lines 152 and 153. Reference numeral 154 indicates a magnetic head manufactured by this method. Here, the sliding surface A with the tape has a structure including a ferrite magnetic core 147, 148 having a width equal to 1 to rack width T, and glass 150, 151 melt-filled on both sides of the ferrite magnetic core 147, 148. A gap 149 is formed uniformly below the winding window 155. Also, the thickness of the lower part of the herad core S
is set to a value larger than the track width T.

Problems to be Solved by the Invention However, in the conventional example shown in FIG.
It is extremely difficult to accurately determine the butting position of the two, and it is difficult to obtain an accurate track width T. That is, although FIG. 10 shows an enlarged view of the vicinity of the gap 133, even if the width of the magnetic cores P1 and P2 is processed to exactly match the track width T, when the two cores P□ and P2 are brought together, When the deviation t occurs, the track width To of the entire head becomes To=T-7, and there is a problem that an accurate track width cannot be obtained.

Further, in the conventional example shown in FIG. 9, although the deviation of the track portion as shown in FIG. 10 is eliminated, there is a problem that the manufacturing process of the magnetic head becomes extremely complicated.

Furthermore, in the case of the conventional example shown in FIG. 11, it is easy to achieve accurate track width accuracy, but when the track becomes narrow, glass occupies most of the tape sliding surface, and the conventional example shown in FIG. In comparison, glass is much inferior in terms of wear resistance, and glass is softer than ferrite, so it can become rough due to sliding with the magnetic tape, causing clogging and a reduction in head output. Another drawback is that the gap 144 becomes loose when glass 146 is melted and filled into the groove 145 during the head manufacturing process, resulting in poor gap length accuracy.

SUMMARY OF THE INVENTION The present invention solves these problems and provides a method for manufacturing a magnetic head that can accurately measure the track width, has excellent head characteristics, and exhibits less head wear.

Means for Solving the Problems In order to solve the above problems, the present invention provides: Of the first and second magnetic core halves each consisting of a rectangular parallelepiped block of high magnetic permeability ferrite with one surface mirror-wrapped, A groove having a predetermined depth is formed in a part of the mirror surface of at least one magnetic core half, and a gap material made of a non-magnetic material with a high melting point is placed in the groove to a thickness equal to or more than the depth of the groove. forming a winding window on the mirror surface of the other magnetic core half; pressing and heating the mirror surfaces of both magnetic core halves in contact with each other; bonding above and below the wire window to form a magnetic core;

forming a plurality of kerfs whose depth exceeds the upper end of the winding window and which are parallel to each other in the upper part of the winding window in the formed magnetic core to form a predetermined track; inserting a wear-resistant member and melting and filling glass between the magnetic core and the wear-resistant member; The method includes the steps of cutting the magnetic core at a location where portions of the member remain on both sides of the track, and polishing the upper part of the winding window to a suitably curved surface.

Operation: By doing so, a magnetic head with accurate track width accuracy can be obtained. It also has excellent wear resistance, and wear on the head surface is even.

Since good contact between the head and the tape can be obtained, a magnetic head with excellent head characteristics can be obtained.

Embodiment An example of the structure of a magnetic head manufactured according to the present invention is shown in FIG. Here, numerals 1 and 2 are magnetic cores made of Mn--Zn ferrite, which form the rear part of the magnetic head. The magnetic helad cores 4 and 5 at the sliding surface A with the magnetic tape are perpendicular to the sliding surface A and are arranged so that they have the same width due to the two faces C and C that are approximately parallel to the side surface A of the head, and the width thereof is is formed to be equal to the track width T. Note that the track width T is smaller than the width S of the magnetic cores 1 and 2. Furthermore, a gap 3 is formed on the opposing surfaces of the magnetic helad cores 4 and 5 by depositing a non-magnetic material such as 5i02 to a predetermined thickness by a method such as sputtering. 6 is a reinforcing member made of a wear-resistant material, and this wear-resistant material includes non-magnetic ferrite,
Magnetic ferrite or ceramics such as alumina can be used. The desirable conditions for the reinforcing member 6 are that the wear rate due to sliding with the magnetic tape is approximately equal to that of the magnetic head core 4.5, that the coefficient of thermal expansion is approximately equal to that of the magnetic head cores 4 and 5, and that the surface of the magnetic tape is For example, it must not cause any damage.

7 is an adhesive layer for bonding the magnetic helad cores 4, 5 and the reinforcing member 6, and glass is most commonly used. Note that the adhesive layer 7 connects the magnetic core 4.5 and the reinforcing member 6.
If the reinforcing member 6 is magnetically insulated, magnetic ferrite similar to that of the magnetic head core 4.5 may be used as the material of the reinforcing member 6.

8 is a winding window, and 9 is a joint between the magnetic cores 1 and 2.

The magnetic cores 1 and 2 may be joined directly to each other by hot pressing or the like, or by melting glass as in the conventional method.

Next, an example of how to make the magnetic head of the present invention will be described with reference to FIG. First, as shown in Fig. 2(a), Mn-Zn
A surface 11 of a first magnetic core half 10 made of ferrite is lapped to a mirror surface, and a groove 12 having a depth G and a width W equal to a desired gap length is formed in a part of the lapped surface 11 by chemical etching. Next, a high melting point nonmagnetic material such as Sio2 is deposited in the groove 12 to a depth equal to or slightly thicker than the depth G by a method such as sputtering to form the gap material 13. At this time, the width of the gap material 13 is made slightly smaller than the width W of the groove 12. Further, a winding window 16 is formed in the second magnetic core half 14, and the surface 15 on which the winding window 16 is formed is lapped to a mirror finish. Next, Figure 2(b)
As shown in , the mirror-wrapped surfaces 11.15 of the pair of magnetic core halves 10.14 are brought into contact with each other.

Apply pressure from the direction of arrow B to approximately 130°C in a N2 atmosphere.
Heat to 0°C. At this temperature, the ferrite material softens slightly and the two magnetic core halves 10.14 are firmly joined above and below the groove 12, ie in the area indicated by the dotted line 18.17. In addition, the gap material 13, which has a thickness equal to or greater than the depth G of the groove, also softens slightly at this temperature and is crimped by the magnetic core halves 10.14, leaving a gap between the two magnetic core halves 10.14. Groove 1 without creating
A gap with a constant thickness corresponding to the depth G of 2 can be formed.

Next, as shown in FIG. 2(c), a predetermined angle α is applied to the upper part of the magnetic core in which the magnetic gap is formed, from a direction perpendicular to the gap line, that is, the joining line 19 of both magnetic core halves 10.14. Machining a groove 20 having a surface inclined by
A magnetic head front portion 21 having a width T is sequentially formed. At this time, the depth D of the kerf 20 is made larger than the height H from the top of the core to the winding window 16. Next, as shown in FIG. 2(d), non-magnetic ferrite, alumina,
A wear-resistant member 22 made of a material with excellent wear resistance such as crystallized glass is disposed, and glass 24 is melted and filled between the wear-resistant member 22 and the head front portion 21 .

Then, by cutting at the dotted line 23, as shown in Fig. 2 (
Obtain a magnetic herad tip as shown in e). FIG. 2(e) shows a cross section taken along the dotted line 23. The magnetic head shown in FIG. 1 can be obtained by dropping the magnetic head front portion of this head chip on a suitable curved surface 25 until the gap material I3 appears. In addition,
It is important to select the glass 24 to be melted and filled here whose softening and melting temperature is lower than the temperature at which the magnetic core halves 10.
Glass at around ℃ is desirable.

The method of arranging the wear-resistant member 22 is shown in FIG. 3(a).
As shown in Fig. 2, a kerf 2 is formed in the magnetic core after the gap is formed.
0, and the magnetic head front section 21 is sequentially formed, and then the member 26 shown in FIG. 3(b) is fitted. That is, the member 26 is made of alumina.

Protrusions 28 whose pitch E' is the same as the pitch E of the cut grooves 20 and whose width F' is smaller than the width F of the cut grooves 20 are formed on the substrate 30 of a wear-resistant reinforcing member such as non-magnetic ferrite. A groove 27 is inserted. Cut this protrusion 28 into the groove 2.
Combine the two into 0.

And as shown in FIG. 2(d), there is a glass 24 in the gap between the two.
The magnetic head shown in Fig. 4 can be obtained by melting, pouring, and bonding, then scraping off the excess portion, and cutting into individual helad chips as shown in Fig. 2(d) and below. .

In the thus obtained magnetic head, the side surfaces d and e of the reinforcing member 6 made of the wear-resistant member 22 disposed on both sides of the gap are parallel, and the magnetic head cores 4 and 5 and the reinforcing member 6 are parallel to each other. Parallelism can be easily obtained, wear of the head surface due to sliding with the tape becomes uniform, and good head characteristics can be obtained. In addition, the magnetic head cores 4 and 5
If the reinforcing member 6 or the two reinforcing members 6 are not arranged in parallel, the head surface will wear unevenly, making it difficult to obtain a good contact between the head and the tape, and damaging the head characteristics. .

Furthermore, as shown in FIG. 3(c), if a groove 29 is made in a direction perpendicular to the groove 27 before making the groove 27,
It becomes possible to obtain the magnetic head shown in FIG. Fifth
As shown in the figure, the magnetic head! Being able to detect the gap depth X during the two-manufacturing process is extremely effective in making the head characteristics uniform. This is because the head characteristics and the gap depth X are closely related, and making the gap depth X constant makes the head characteristics uniform. In the example shown in FIG. 5, the magnetic herad cores 4, 5
There are four reinforcing members 31, 32, 33, and 34 arranged on both sides of the reinforcing member 31, 32, 33, and 34, but since they are made as described above, the reinforcing members 31, 32, and 33, 34 are the same as in the example of Fig. 4. are parallel to each other and parallel to the magnetic helad cores 4 and 5, making it possible to obtain uniform head surface wear. Also, the distance N between the reinforcing members 33 and 34 and the reinforcing member 31.
The intervals M of 32 are also equal, making it easy to obtain uniform wear. In addition, here the reinforcing members 31.32.33.34
The same magnetic ferrite as the magnetic herad cores 4 and 5 is used, and the magnetic herad cores 4 and 5 are made of molten filled glass 7.
If the reinforcing members 31° 32, 33.34 are arranged so that they do not come into contact with each other, the wear rate, thermal expansion coefficient, and other physical properties of the reinforcing members 31° 32, 33.34 and the magnetic helad cores 4, 5 will be completely reduced. Accordingly, it becomes possible to obtain a more preferable magnetic head.

Next, FIG. 6 shows another embodiment in which a gap is formed.
It is shown in FIG.

In FIG. 6, grooves 12.40 are formed on the mirror-wrapped surfaces of both magnetic core halves 10.14 by a method such as etching so that the total depth G of both grooves 12.40 is equal to the gap thickness. Then, a gap material 13.41 made of a non-magnetic material such as 5L02 is deposited in both grooves 12.40 to a thickness equal to or greater than the gap thickness by a method such as sputtering, and the rear core halves 10.14 are mirror-polished to each other. Apply pressure while in contact with the
It is heated and joined.

In this case, the gap materials 13.41 are softened by heating, and the gap materials 13.41 are bonded together.
This enables even stronger gap bonding.

Further, by depositing the gap material 13° 41 up to the oblique side 42 of the winding window 16, it is effective in preventing chipping and chipping of the oblique side 42 during track machining during the head manufacturing process.

Further, in the example shown in FIG. 7, two types of materials having different softening points are used as the gap material. That is, in the groove 12, there is a thin film layer 4 made of 99% quartz and Sin having a softening temperature of about 1250°C.
3 is first formed, and then Si0 with a softening temperature of about 1100°C is formed.
A thin film layer 44 of a glass material containing 95% □, B, O, and 5% others is formed in an overlapping manner. The total thickness G' of both groove film layers 43 and 44 is made equal to or greater than the gap thickness, that is, the depth G of the groove 12. In this state, when joining the other half of the magnetic core at a high temperature of 1200°C, the gap material 44 softens and the joining force with the other half of the magnetic core becomes stronger. The thickness of the gap material becomes exactly equal to the groove depth G6.In addition, in the manufacturing process of the head explained in FIG.
When cutting along the dotted line 23 in step d), finish the upper part of the winding window 16 by grinding and lapping so that a gap appears, and after confirming that the correct gap length has been obtained, proceed to the procedure of cutting into each chip. 1 makes it more efficient.

Effects of the Invention According to the present invention, a magnetic head having accurate track width accuracy can be obtained. In addition, it has excellent wear resistance and
Since the wear on the head surface becomes uniform and the contact between the head and the tape becomes good, a magnetic head with excellent head characteristics can be obtained.

Furthermore, in the present invention, since the pair of magnetic helad cores are obtained by simultaneous processing, they are perfectly straight and it is possible to prevent unnecessary signals from adjacent tracks.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the configuration of a magnetic head obtained by a method for manufacturing a magnetic head based on an embodiment of the present invention, and FIG.
3 shows the method of manufacturing the same, FIG. 3 shows the method of arranging the wear-resistant member, FIG. 4 shows an example of the magnetic head obtained based on FIG. 3, and FIG. 3 is a diagram showing another example of the magnetic head obtained based on FIG. 3, FIG. 6 is a diagram showing another embodiment of the present invention, FIG. 7 is a diagram showing still another example of the present invention, and FIG. The figure shows the first conventional example, Fig. 9 shows the second conventional example, Fig. 10 shows the main part in Fig. 8 in detail, and Fig. 11 shows the third conventional example. FIG. 1.2... Magnetic core, 10... First magnetic core half, 11, 15... Surface, 12... Groove, 13... Gap material, 14... Second magnetism Core half, 16... Winding window, 20... Cut groove, 22... Wear-resistant member, 24
...Glass, 25...Curved surface agent Morimoto
YoshihiroFigure 7Figure 4Figure 5Figure 7Figure 7

Claims (1)

[Claims] 1. The mirror surface of at least one of the first and second magnetic core halves each consisting of a rectangular parallelepiped block of high magnetic permeability ferrite wrapped with a mirror surface on one surface. A step of forming a groove having a predetermined depth in one part, and forming a gap material made of a high melting point non-magnetic material in the groove to a thickness equal to or more than the depth of the groove, and the other magnetic core half. A process of forming a winding window on the mirror surface of the body, pressing and heating the mirror surfaces of both magnetic core halves in contact with each other, and joining both magnetic core halves above and below the winding window to create a magnetic forming a core, and forming a plurality of grooves in the upper part of the winding window in the formed magnetic core, the depth of which exceeds the upper end of the winding window and which are parallel to each other to form a predetermined track; a step of inserting a wear-resistant member into the kerf and melting and filling glass between the magnetic core and the wear-resistant member; and a plane parallel to the direction of the kerf formed in the magnetic core. and cutting the magnetic core at a position where a portion of the wear-resistant member is left on both sides of the track; and polishing the upper part of the winding window into an appropriate curved surface. manufacturing method. 2. The method of manufacturing a magnetic head according to claim 1, wherein the gap material is formed by laminating two layers of two types of nonmagnetic materials with different melting points. 3. The method of manufacturing a magnetic head according to claim 1 or 2, wherein the wear-resistant material is made of a non-magnetic material. 4. The method of manufacturing a magnetic head according to claim 1 or 2, wherein the wear-resistant material is made of a ferrite material that is the same as the high magnetic permeability ferrite constituting the magnetic core.