JPS62132208A - Manufacture for 'sendust(r)' type alloy magnetic head core - Google Patents

Abstract

PURPOSE:To improve a gap accuracy all the more and to prevent the flowing of the reinforced material to a coil winding window by executing a head groove processing of a junction block so that a track width remains in the direction to cross in the length direction of rectangular space and charging the reinforced material to the formed head groove after a filling chock is filled along the length direction at the front part side of the rectangular space. CONSTITUTION:From 'Sendust(R)' rectangular block, block plates 2a and 2b are cut out, a linear groove is formed on the plate surface of one side block plate 2a, and therefore, a non-bonding processing is executed to a front part, a brazing material processing is executed to a back part, the block plates 2a and 2b are laminated to face each other, said linear groove is left as a rectangular coil winding window W and both of them are junctioned. Next, after at the area of the front part side of the coil winding window W, along the length- wise direction, an SiO2 type glass 14 is filled, in the direction to cross the coil winding window W up to the depth to cut into a filling chock 14 a little, a head groove processing is executed so as to remain the track width, and next, a reinforced material 13 of the same material as the filling chock is charged to the head groove. At such a time, since the head groove bottom part is closed by the filling chock, the reinforced material 13 will not flow into the coil winding window W.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a magnetic head core used for high-density magnetic recording in VTRs, etc., and more particularly, to a method for manufacturing a magnetic head core using a sendust alloy as a material. ,
By improving the manufacturing process, we have succeeded in eliminating problems such as poor gap accuracy and blocked coil winding windows, which were considered unavoidable in conventional manufacturing procedures.

[Prior Art] Regarding magnetic recording media for video or audio, there is a strong desire to record information signals at high density within a narrow track. In order to meet this demand, magnetic head cores using sendust alloys are being developed, and magnetic head cores with narrow gap widths and narrow track widths are being provided. Metallic magnetic materials, represented by sendust alloys, have the property of having a higher saturation magnetic flux density than conventional ferrite-based materials, and are attracting attention for this reason. There are some aspects that cannot be applied to the production of heads made of metal magnetic materials, and for example, new methods have been developed that use silver solder for fixing block plates.

FIG. 3 is an explanatory diagram showing a conventional manufacturing procedure using a Sendust alloy (hereinafter simply referred to as Sendust in this specification) as a material. First, in step (A), a block plate 2 is cut out from a rectangular block 1 of sendust. Next, in the CB) process (generally referred to as wafer processing), the block plate is divided into a groove processing block plate 2a and a non-groove processing block plate 2b.
A straight groove 3 is formed on the plate surface (particularly one side surface) of the former 2a.

The straight groove 3 is a coil winding window W (see Fig. 4 (H)), which will be described later.
It is generally formed to be placed on one side of the groove machining block plate 2a and parallel to the side 14S. The narrower bank with the straight groove 3 in between is called the front part 4, and the wider bank is called the back part 5. In step (C), the surface of the front part 4 is subjected to non-adhesive processing (a process in which a non-magnetic substance is applied in a thin film form, also referred to as non-magnetic film adhesion processing) 4a, and non-groove processing is performed. The block plate 2b has a fourth side facing the front part 4b.
Referring to FIG. (E), a comb blade 6 having a narrow track width T is formed by cutting the surface in a direction perpendicular to the straight groove 3. In step CD), the comb blades 7 are formed on the front portion of the block plate 2a so that the track widths T described above are completely matched.

Next, in step (E), two block plates 2a are formed.

2b are stacked so as to face each other, and the two are joined while leaving the above-mentioned straight groove as a rectangular space. For joining, silver solder or the like is interposed between the surface of the back part 5 and the surface of the block 2b facing it, but the front part 4 is treated with non-adhesive processing (for example, silica vapor deposition) as described above. (formation of a film), only the back portion 5 is joined, and the front portion 4 is merely in opposing contact.

However, this opposing abutment is required to be extremely accurate considering the narrow track width T. However, since this track width T is generally about 20 to 30 μm and extremely thin, it is difficult to avoid the occurrence of burrs no matter how much comb cutting is performed using an ultra-precision cutting machine (reference photo). This poses a serious obstacle to improving the gap accuracy between opposing contact surfaces. Also, both block plates 2a
, 2b must be avoided at all costs when stacking and bonding (particularly in the track width direction); however, due to insufficient work jigs to guarantee positioning accuracy, misalignment often occurs and the magnetic head This causes the playback output to decrease.

The magnetic head core is then filled with reinforcing material 8 in the (F) process, and cut and divided in the (G) process [the cutting line is indicated by a broken line in the (F) process, and α is called the azimuth angle. ], the front part is polished in the (H) process, but in the (F) process, the reinforcing material may flow into the rectangular space and fill the coil winding window W. It has also been pointed out that the coil winding operation becomes impossible.

[Problems to be solved by the invention, namely, in the above manufacturing method, (C) Occurrence of defects in the process, (E) Track positional deviation in the process, (F
) There were problems such as reinforcing material flowing into the process, which caused problems such as poor gap accuracy in the magnetic head and blockage of the coil winding window.

The present inventors have been researching ways to solve these problems for some time, and have changed the conventional technique of cutting the front part and then joining the block plates.
After joining the block plates and forming a dummy joint on the front side of the block plates (after the front parts are brought into contact with each other), we discovered a method to perform the machining process, and we applied for a patent earlier. No. 59-98398). That is, in the method of the prior application, as shown in FIG. 4, a cutout step 9 is formed on the front end side of one block plate, and then, as shown in step (C), a cutout step 9 is formed in the part corresponding to the cutout step of the block after joining. A dummy joint is formed on the tip side of the front part by charging a low melting point brazing filler metal etc.
After that, as shown in step (D), the combing process is performed including the dummy joint, and the combing process is performed on the joint block with the front part reinforced by the dummy joint, so the position of the track is Misalignment has been eliminated, and the occurrence of dents that degrade gap accuracy has also been reduced.

However, when applying the comb cutting process to the joint block, it is necessary to set the cutting depth so that it reaches a part of the coil winding window, so when pouring reinforcing material into the joint block after the comb cutting process, However, it was not possible to prevent the reinforcing material from flowing into the coil winding window, and it was not possible to solve the problem of the coil winding window being blocked. In addition, gap accuracy on the lower side of the front part, that is, on the side of the coil winding window, is important for a manufactured magnetic head, but in the method of the prior application, only the upper side of the front part is dummy-bonded, so the part following the coil winding window is large. This left the opening open, causing burrs to appear when facing the coil winding window during the cutting process, resulting in poor gap accuracy. In addition, the present inventors subsequently filed a patent application (Japanese Patent Application No. 179031/1986) for another improvement method.
However, the above-mentioned drawbacks have not yet been solved.

The present invention has been made in view of these circumstances, and improves the method of the prior application to provide a Sendust magnetic head core that can further improve gap accuracy and prevent reinforcing material from flowing into the coil winding window. The purpose of this invention is to provide a method for manufacturing.

[Means for Solving the Problems] In the method of the present invention that achieves the above object, after filling the front part side of the rectangular space with a stuffing material along the length direction, the joining block is placed along the length of the rectangular space. The gist of this method is that it includes a step of processing a head groove so as to leave a track width in a direction intersecting the direction, and filling the formed head groove with a reinforcing material.

[Function] In the present invention, it is believed that these drawbacks can be solved all at once by sealing the front side of the rectangular coil winding window, which is the entry point of the reinforcing material and the location where the burr occurs. As a result of further studies based on the guidelines, we arrived at the above configuration.

In other words, when sealing the front side of the coil-wound window, it was decided to fill that part with a filler, but if the filler falls off easily after being filled, it will not be able to fully function as a seal. Since this cannot be achieved, it must be bonded to the inner wall of the block with considerable strength. Therefore, in the present invention, the filling material also has the function of the dummy bonding material of the prior invention, thereby omitting the operations of forming the notch step and filling the dummy bonding material. That is, the filling material not only seals the front side of the coil-wound window but also plays the role of reinforcing the non-bonded front part.

The front side of the coil winding window must be sealed at least before the combing process. However, since the coil winding window is formed after the block plates are joined, the sealing must be carried out either after the joining block is formed or after cutting off the unnecessary portion of the front part of the joining block.

In addition, there are no particular limitations on the type of filling material, but
It is desirable to use a material that exhibits the same thermal behavior as the base material sendust, and a material with a thermal expansion coefficient of (100 to 200) x 10-'/'e is recommended. Further, it is desirable that the melting point is higher than the filling temperature of the head groove reinforcing material and lower than the brazing temperature.

Examples of filling materials that exhibit these characteristics include low-melting silver wax and glass.

Examples include barium titanate, manganese oxide-nickel oxide type ceramics, and the like.

In the present invention, after filling the above-mentioned stuffing material along the longitudinal direction on the front side of the coil winding window, the following operations are performed: machining the head groove for track formation and filling the head groove with reinforcing material. By performing cutting and single curved surface polishing as in the conventional method, a magnetic head core that exhibits high performance can be obtained at a high yield.

[Example] Fig. 1 is an explanatory diagram showing the process of manufacturing a magnetic head core according to the procedure of the present invention, in which (A) block plates 2a and 2b are cut out from a rectangular block of sendust, and one block plate 2a is cut out. After forming a straight groove on the plate surface, the front part is treated with no adhesive and the back part is treated with a brazing material, and the block plates 2a and 2b are stacked so as to face each other, and the straight groove is used as a rectangular coil winding window W. The figure shows a state in which the two are joined while leaving the two parts intact. Note that the operations up to this point are the same as in the conventional case. However, in this example, the length of the front part was determined according to the earlier application method (Japanese Patent Application No. 6
0-179031) < 0.03~0.06m
It is adjusted so that it becomes m. Next, in the step (B), 70 mm is applied to the front side area of the coil winding window W along the longitudinal direction.
After filling the 5i02 glass (filling material) 14 adjusted to 0°C, in step (C), the filling material 14 is cut in a direction transverse to the coil winding window W to a depth L 10μ) so as to slightly cut into the filling material 14. Head groove processing is done to leave the width, (D)
In the process, a reinforcing material 13 made of the same material as the filling material was filled into the head groove. During these operations, the padding material 14 supports the track piece 12 from the bottom side, so the track will not be torn off or misaligned due to external force during head groove machining, and will not penetrate further into the coil winding window W. There will be no occurrence of any kind of accident. Further, when filling the reinforcing material 13, the bottom of the head groove is closed by the stuffing material, so that the reinforcing material 13 does not flow into the coil winding window W. Incidentally, since a part of the coil winding window W is filled with the filler 14, the cross-sectional area of the coil winding window W is reduced, but there is no particular problem in winding the coil. Next, the joint block shown in (D) is cut and divided along the broken lines in the figure to obtain the core shown in (E), and the top surface of the core chip is further ground into a curved shape (F).
A magnetic head core as shown in the figure is obtained.

FIG. 2 is a graph comparing the yield of good products when magnetic head cores were manufactured using the method of the prior application (Japanese Patent Application No. 179031/1982) and the method of the present invention.

The cause of the failure is limited to the occurrence of cracks and the flow of reinforcing material. As shown in FIG. 2, the present invention was able to dramatically improve the yield of non-defective products.

[Effects of the Invention] The present invention is configured as described above, and a gap can be stably formed without the coil winding extending toward the window side. Additionally, since the reinforcing material does not flow into the coil winding window, the number of coil winding defects in the subsequent process has been drastically reduced. In this way, we were able to dramatically improve the yield of product magnetic head cores.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the method of the present invention, Figure 2 is a graph comparing the yield of the method of the present invention and the method of the prior application, Figure 3 is an explanatory diagram showing the conventional method, and Figures 4.5 are the method of the prior application. FIG. 2a, 2b...Block plate 3...Straight groove 4...
Front part 4a... Non-adhesive processing 5... Back part 12... Head groove 12a... Track piece 13... Reinforcement material 14... Filling material

Claims (1)

[Claims] A pair of block plates made of sendust alloy are used as raw materials, and a straight groove is formed on the surface of at least one of the block plates to make the bank on one side the front part and the bank on the other side the back part. Both block plates were stacked so as to sandwich the two block plates, and the back part was joined to the other block plate surface while leaving the straight groove as a rectangular space, and the resulting joined block was cut and divided in the direction intersecting the rectangular space. In the method for manufacturing a sendust alloy magnetic head core, the method includes a step of polishing the front portion of each divided piece to give a curved surface.
After filling the front part side of the rectangular space with filler material along the length direction, the joint block is formed by processing a head groove so as to leave a track width in a direction intersecting the length direction of the rectangular space. A method for manufacturing a sendust-based alloy magnetic head core, the method comprising the step of filling a reinforcing material into a head groove formed by a magnetic head.