JPH07176011A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To finish the medium-sliding surface of a magnetic head with high accuracy. CONSTITUTION:Fused wax 23 is adhered to a smooth surface 21 of a heated surface plate 20 and plural front part core assemblies 10 are placed on the surface plate in this state by directing their rear end faces 2C, 8Ca, 8Cb toward the smooth surface of the surface plate. A weight 24 is placed thereon and is pressurized from their medium-sliding surfaces. The wax 23 is cooled in this pressurized state. The pressurization is released at the point of the time when the melt viscosity before curing rises. Further, the wax is cooled in this non-pressurized state and the medium-sliding surfaces of the assemblies are ground after the wax cures completely and the assemblies are held fixed to the surface plate. Then, the flatness of the medium-sliding surfaces of the assemblies is finished with high accuracy, by which the head squeaking at the time of magnetic recording and reproducing is prevented. Since the touch of the magnetic head and the magnetic medium is improved, the electromagnetic conversion characteristics are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head, and more particularly to a method of manufacturing a magnetic head which can be used in cooperation with a magnetic medium such as a floppy disk so that the sliding surface of the medium can be polished well. is there.

[0002]

2. Description of the Related Art In the following description, a magnetic head for a floppy disk will be taken up as a magnetic head, and a magnetic head of the prior art will be taken up by taking a composite type magnetic head composed of a front core and a rear core. A method of manufacturing the head will be described with reference to FIGS. 3 is an enlarged perspective view showing a magnetic head element that constitutes a magnetic head in use, and FIG. 4 is an enlarged perspective view of a front core assembly incorporating the front core of the magnetic head element of FIG. 5 is a process diagram for explaining a fixing method of fixing the front core assembly to a jig when polishing the medium sliding surface of the front core assembly as shown in FIG. 4, and FIG. FIG. 7 is a perspective view showing a rear end surface of the front core assembly for explaining an unfavorable phenomenon caused by the method of fixing the front core assembly to the jig in the art.

First, the structure of the composite magnetic head element 1 will be described with reference to FIG. This magnetic head element 1 has a magnetic path composed of a front core 2A and a rear core 2B.
Further, the front core 2A is a magnetic recording / reproducing head element 5A in which a recording / reproducing gap 4A is formed on a sliding surface 3A of the magnetic medium.
And a magnetic erasing head element 5B in which an erasing gap 4B is formed on a magnetic medium sliding surface 3B that is on the same surface as the magnetic medium sliding surface 3A are bonded together by glass 6A to form a composite type. It is configured.

Therefore, the rear core 2B is also constructed corresponding to the front core 2A, and the U-shaped core 7A for the magnetic recording / reproducing head element 5A and the magnetic erasing head element 5 are provided.
The U-shaped core 7B for B is bonded and integrated with the glass 6B.

The rear core 2B having this structure is joined to the rear side surface (the hatched portion in FIG. 3) of the front core 2A to form a magnetic path, and each magnetic recording / reproducing head element 5A is formed.
And the magnetic erasing head element 5B are combined to form the magnetic head element 1.

In order to reinforce the magnetic head element 1 and prevent the magnetic medium from being scratched by the magnetic head element 1, the front core 2A of the magnetic head element 1 is used.
As shown in FIG. 4, the guard members 8A, 8B made of ceramic are sandwiched between the gap forming portions.
Are abutted and adhered to each other to form a front core assembly (hereinafter, simply referred to as “assembly”) 10. Therefore, the magnetic medium sliding surfaces 9A, 9B are also attached to these guard members 8A, 8B.
B is the magnetic medium sliding surfaces 3A, 3B of the magnetic head element 1.
It is formed by a surface that is continuous with. The rear end surface 2C of the front core 2A and the rear end surfaces 8Ca and 8Cb of the guard members 8A and 8B are also designed to be flush with each other. Reference numeral 11 is a groove formed in the guard member 8B.

The magnetic medium sliding surfaces 3A, 3B, 9A and 9B of the assembly 10 having such a structure must be finished to be super smooth surfaces of the order of several nanometers. Therefore, the assembly 10 is polished in the next grinding and polishing steps. Before performing this polishing, the platen 20 which is a jig as shown in FIG. 5A is heated by the heater 22,
A wax 23 is applied to the upper smooth surface 21 to a predetermined thickness, the wax 23 is melted, and the molten wax 2
3, the plurality of the assemblies 10 in a row, and as shown in FIG. 3B, their rear end faces 2C, 8C.
The a and 8Cb are placed facing the smooth surface 21 of the surface plate 20.

Next, as shown in FIG. 1C, a common weight 24 is placed on all the assemblies 10 and a weight is evenly applied to the magnetic media sliding surfaces 3A, 3A of all the assemblies 10.
With B, 9A, and 9B aligned, the heater 22 is stopped, the surface plate 20 is naturally cooled, and the molten wax 23 is cured.

Then, after the molten wax 23 is completely hardened, the weight 24 is removed and sent to the next grinding and polishing steps, and the magnetic medium sliding surfaces 3A, 3B, 9A of all the assemblies 10 are 9B is ground and polished to obtain a smooth surface.

[0010]

However, the rear end surfaces 2C, 8Ca, 8Cb of the assembly 10 are machined so that they are flush with each other in design, but in reality, there is a limit in machining accuracy, and As shown in 6A, the rear end faces 2C, 8Ca, 8Cb, for example, the rear end face 8Ca of the guard member 8A with respect to the rear end face 2C of the front core 2A, is offset by a length T at one side edge thereof, This deviation is extremely slight, but due to this deviation, the rear end faces 2C, 8
The surface formed by Ca and 8Cb is twisted. As described above, there are relatively many front cores 2A in which the rear end surfaces 2C, 8Ca, 8Cb are twisted.

When this twisted assembly 10 is pressed as shown in FIG. 5C, it follows the smooth surface 21 of the surface plate 20, and as shown in FIG. 6B, all the rear end surfaces 2 are formed.
C, 8Ca, and 8Cb will be aligned on the plane, so
Magnetic medium sliding surface of assembly 10 Magnetic medium sliding surface 3A,
The amount of the twist of the dimension T of the rear end faces 2C, 8Ca, 8Cb appears on 3B, 9A, 9B, which means that they are deformed.

Thus, in FIG. 5C, the assembly 1
Many of the magnetic medium sliding surfaces of 0 are in such a deformed state. Therefore, when the magnetic medium sliding surfaces 3A, 3B, 9A, 9B in this state are ground and polished in the next step,
Although it can be finished on a flat surface, in this next step,
If the wax 23 cured with a solvent is removed and all the assemblies 10 are removed from the surface plate 20, the individual assemblies 10 will return to the state of FIG. 6A.

Accordingly, the ground and polished assembly 10
Of the magnetic medium sliding surface 3A, 3B, 9A, 9B, in the above example, the plane of the magnetic medium sliding surface 9A of the guard member 8A with respect to the plane of the magnetic medium sliding surface 3A, 3B of the front core 2A is also twisted. Therefore, the flatness becomes poor. The size of this twist is actually on the order of several to several tens of nanometers. However, when high-density recording / reproduction is performed, even with this minute size, the touch between the magnetic head and the magnetic medium becomes poor, Good magnetic recording and reproduction cannot be expected. An object of the method of manufacturing a magnetic head of the present invention is to eliminate such inconvenience.

[0014]

Therefore, in the method of manufacturing a magnetic head according to the present invention, molten wax is adhered to a smooth surface of a heated surface plate, and a plurality of the above-mentioned assemblies are then placed on the surface plate in this state. Placing the end face toward the smooth surface of the surface plate, pressurizing it with a weight or the like from above the medium sliding surface, and cooling the molten wax in this pressurized state are Similarly, the pressure is released when the melt viscosity before hardening of the molten wax becomes high, and the wax is further cooled in the non-pressurized state to completely cure the wax, The problem has been solved by adopting a method of polishing the medium sliding surface of the assembly after the assembly is fixed to the surface plate.

[0015]

Therefore, the flatness of the medium sliding surface of the assembly can be finished with high precision.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a magnetic head according to the present invention will be described below with reference to FIGS. FIG. 1 is a flow chart for explaining a fixing method of the present invention in which the assembly is fixed to a jig when polishing the medium sliding surface of the assembly shown in FIG. 4, and FIG. It is a molten clay curve of the wax used for the fixing method of 1. It should be noted that, in FIG. 1, the same components as those used in the fixing method of the prior art are designated by the same reference numerals and described.

As shown in FIG. 1A, in the method of fixing the assembly in the method of manufacturing a magnetic head according to the present invention, a platen 20 which is a jig is heated by a heater 22, and a wax 23 is applied to a smooth surface 21 on the upper surface thereof. Apply to a predetermined thickness, melt this wax 23, from above the molten wax 23,
The plurality of assemblies 10 are placed in a row, and as shown in FIG. 6B, their rear end surfaces 2C, 8Ca, 8Cb are placed facing the smooth surface 21 of the surface plate 20. Up to this step, it is the same as the conventional fixing method described with reference to FIG.

Next, as shown in FIG. 1C, the common weight 24 is placed on all the assemblies 10 and the weight is evenly applied to the magnetic medium sliding surfaces 3A, 3A of all the assemblies 10.
With B, 9A, and 9B aligned, the heater 22 is stopped, the surface plate 20 is naturally cooled, and the melt viscosity of the molten wax 23 is increased.

Then, as shown in FIG. 3D, when the molten wax 23 is not cured and the pressure applied by the weight 24 is released, the distortion caused by the pressure applied to the assembly 10 can be restored. When the melt viscosity becomes high, the weight 24 is removed to release the pressure (release of pressure),
Then, the natural cooling is continued in this non-pressurized state.

Then, after the molten wax 23 is completely hardened and the assembly 10 is firmly fixed to the surface plate 20, the assembly 10 is sent to the next grinding and polishing step, and the magnetic medium sliding surfaces 3A of all the assemblies 10 are 3B, 9A, and 9B are ground and polished to a flat surface.

The wax used in the present invention is a product "Micron MW" manufactured by Nikka Seiko Co., Ltd., and its melt viscosity characteristic is shown in FIG. When the pressure is released when this wax is used, for example, when the temperature of the platen 20 reaches 70 ° C., the wax has a melt viscosity of 3 to 3 from a molten state.
When the pressure rises to 000 CP and becomes in this molten state, the assembly 10 no longer changes its position on the surface plate 20 to the front, rear, left and right thereof.

However, the rear end faces 2C, 8 of the assembly 10 are
When Ca and 8Cb have a twist as shown in FIG. 6A, the rear end faces 2C, 8Ca, and 8Cb of these Ca and 8Cb are flattened as shown in FIG. The melt viscosity of the wax 23 is 3,000
By releasing this pressure in the high CP state, the rear end faces 2C, 8Ca, 8Cb can be returned to the original state shown in FIG. 6A.

Therefore, the magnetic medium sliding surfaces 3A, 3B of the assembly 10 in which the twist of the original restored state exists,
By grinding and polishing 9A and 9B (FIG. 4), a good magnetic head could be obtained, and the above problems could be solved.

In the above embodiment, the magnetic head is composed of the front core and the rear core, the magnetic head element is reinforced by the guard member, and is composed of the magnetic recording / reproducing head element and the magnetic erasing head element. Although the composite type magnetic head has been illustrated, it should be added that the present invention is not limited to the magnetic head having such a configuration, but can be widely applied to a method of manufacturing a magnetic head.

[0025]

As is apparent from the above description, according to the method of manufacturing a magnetic head of the present invention, the flatness of the medium sliding surface of the assembly can be finished with high precision, and the improvement of the flatness can be achieved. Since the head squeal can be prevented at the time of magnetic recording / reproducing and the touch between the magnetic head and the magnetic medium is improved, the electromagnetic conversion characteristics can be improved, and various excellent effects are obtained.

[Brief description of drawings]

FIG. 1 is a process diagram showing a fixing method of fixing a front core assembly to a jig for explaining a method of manufacturing a magnetic head according to the present invention.

FIG. 2 is a molten clay curve of the wax used in the fixing method of FIG.

FIG. 3 is an enlarged perspective view showing a magnetic head element that constitutes a current magnetic head.

4 is an enlarged perspective view of a front core assembly incorporating the front core of the magnetic head element shown in FIG.

FIG. 5 is a process diagram showing a fixing method for fixing the front core assembly to a jig, for explaining a conventional magnetic head manufacturing method.

FIG. 6 is a perspective view illustrating a rear end surface of the front core assembly for explaining an unfavorable phenomenon caused by a method of fixing the front core assembly to a jig according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 magnetic head element 2A front core 2B rear core 2C rear end surface of front core 3A magnetic medium sliding surface 3B magnetic medium sliding surface 4A recording / reproducing gap 4B erasing gap 5A magnetic recording / reproducing head element 5B magnetic erasing head element 6A glass 8A guard member 8B guard member 8Ca guard member 8A rear end surface 8Cb guard member 8B rear end surface 9A magnetic medium sliding surface 9B magnetic medium sliding surface 10 front core assembly 20 surface plate (jig) 22 heater 23 melting Wax 24 weight

Front page continuation (72) Inventor Eiji Yamauchi 30 Takagami, Takae, Niida, Nakata-cho, Tome-gun, Miyagi Prefecture Sony Precision Magne Co., Ltd.

Claims (1)

[Claims] 1. In polishing a medium sliding surface of a magnetic core constituting a magnetic head, molten wax is adhered to a smooth surface of a heated surface plate, and a plurality of the magnetic particles are placed on the surface plate in this state. Place the core with its rear end facing the smooth surface of the surface plate, and then, in this state, place the magnetic cores
Pressure is applied from above the medium sliding surface with a weight or the like, and the molten wax is cooled under this pressure,
When the melt viscosity before the molten wax becomes high, the pressure is released, and the wax is cooled in the unpressurized state so that the wax is completely cured and the magnetic core is A method of manufacturing a magnetic head, which comprises polishing the medium sliding surface of the magnetic core after being fixed to a surface plate.