JP3496259B2 - Manufacturing method of magnetic head - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention improves the medium sliding surface of a magnetic head, particularly a magnetic head used in cooperation with a magnetic medium such as a floppy disk. The present invention relates to a method for manufacturing a polished magnetic head. 2. Description of the Related Art In the following description, a magnetic head for a floppy disk will be taken as a magnetic head, and a composite magnetic head composed of a front core and a rear core will be described. A method of manufacturing a magnetic head according to the related art will be described with reference to FIGS. FIG. 3 is an enlarged perspective view showing a magnetic head element constituting a current magnetic head, and FIG. 4 is an enlarged perspective view of a front core assembly incorporating the front core of the magnetic head element of FIG. FIG. 5 is a process diagram for explaining a fixing method for fixing the front core assembly to a jig in polishing the medium sliding surface of the front core assembly as shown in FIG. 4, and FIG. FIG. 4 is a perspective view showing a rear end surface of the front core assembly for explaining an undesired phenomenon caused by a method of fixing the front core assembly to the jig according to the technique. [0003] First, the configuration of the composite magnetic head element 1 will be described with reference to FIG. In the magnetic head element 1, a magnetic path is formed by the front core 2A and the rear core 2B.
Further, the front core 2A is a magnetic recording / reproducing head element 5A having a recording / reproducing gap 4A formed on a magnetic medium sliding surface 3A.
And a magnetic erasing head element 5B in which an erasing gap 4B is formed on a magnetic medium sliding surface 3B constituting the same surface as the magnetic medium sliding surface 3A, is bonded with glass 6A to form a composite type. It is configured. Therefore, the rear core 2B is also configured to correspond to the front core 2A, and includes a U-shaped core 7A for the magnetic recording / reproducing head element 5A and a magnetic erasing head element 5A.
The U-shaped core 7B for B is bonded and integrated with glass 6B. The rear core 2B of this configuration is joined to the rear side surface (the shaded portion in FIG. 3) of the front core 2A to form a magnetic path, and the magnetic recording / reproducing head element 5A is formed.
And the magnetic erasing head element 5B. In order to reinforce the magnetic head element 1 and to prevent the magnetic medium from being damaged by the magnetic head element 1, the front core 2A of the magnetic head element 1 is used.
As shown in FIG. 4, the ceramic guard members 8A and 8B are sandwiched between the two gap forming portions.
To form a front core assembly (hereinafter simply referred to as “assembly”) 10. Therefore, these guard members 8A, 8B also have the magnetic medium sliding surfaces 9A, 9B.
B is the magnetic medium sliding surface 3A, 3B of the magnetic head element 1.
And a surface that is continuous. The rear end face 2C of the front core 2A and the rear end faces 8Ca, 8Cb of the guard members 8A, 8B are also formed to be coplanar in design. Reference numeral 11 denotes a groove formed in the guard member 8B. The sliding surfaces 3A, 3B, 9A and 9B of the magnetic medium of the assembly 10 having such a structure must be finished to an ultra-smooth surface on the order of several nanometers. Therefore, the assembly 10 is polished in the next grinding and polishing steps. Before performing the polishing, the platen 20 which is a jig as shown in FIG.
A wax 23 is applied to a predetermined thickness on the smooth surface 21 on the upper surface, and the wax 23 is melted.
3, a plurality of the assemblies 10 are arranged in a line from above, and as shown in FIG.
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 the weight is uniformly 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 cured, the weight 24 is removed and sent to the next grinding and polishing steps, and the magnetic medium sliding surfaces 3A, 3B, 9A, 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 as to be the same in design, but in practice, the machining accuracy is limited. As shown in FIG. 6A, the rear end face 8Ca of the guard member 8A with respect to the rear end face 2C of the front core 2A is shifted by a length T at one side edge thereof. This shift is very slight, but this shift causes 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, and 8Cb are twisted. When the assembly 10 having this twist is pressed as shown in FIG. 5C, it follows the smooth surface 21 of the platen 20, and as shown in FIG.
C, 8Ca, 8Cb will be aligned on a plane,
Magnetic medium sliding surface of assembly 10 Magnetic medium sliding surface 3A,
3B, 9A, and 9B show the amount of the twist of the dimension T of the rear end faces 2C, 8Ca, and 8Cb, which means that the end faces are deformed. Therefore, in FIG.
In many cases, the magnetic medium sliding surfaces 3A, 3B, 9A, and 9B in this state are ground and polished in the next step.
Although it can be finished to a plane, in the next process,
When the hardened wax 23 is removed using a solvent and all the assemblies 10 are removed from the platen 20, the individual assemblies 10 return to the state shown in FIG. 6A. Accordingly, the ground and polished assembly 10
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. As a result, the flatness deteriorates. The size of this twist is actually on the order of several to several tens of nanometers, but when performing high-density recording / reproduction, even with this small 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 present invention is to eliminate such inconvenience. According to the method of manufacturing a magnetic head of the present invention, molten wax is attached to a smooth surface of a heated platen, and a plurality of the assemblies are mounted on the platen in this state. Is placed with its end face facing the smooth surface of the platen, pressurized with a weight or the like from above the medium sliding surface, and cooling the molten wax in this pressurized state, Similar to the prior art, but the melt pressure before the molten wax is cured, the pressure is released when the magnetic core becomes high enough to restore the strain caused by the pressure, and, furthermore, The wax is cooled in this non-pressurized state, and after the wax is completely cured and the assembly is fixed to the surface plate, a method of polishing the medium sliding surface of the assembly is adopted. Solve the problem did. Accordingly, the flatness of the medium sliding surface of the assembly can be finished with high precision. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a magnetic head according to the present invention will be described below with reference to FIGS. FIG. 1 is a process chart for explaining a fixing method of the present invention for fixing the assembly to a jig in polishing the medium sliding surface of the assembly as shown in FIG. 4, and FIG. 2 is a molten clay curve of the wax used in the fixing method 1; In FIG. 1, the same components as those of the jig used in the conventional fixing method are denoted by the same reference numerals. As shown in FIG. 1A, the fixing method of the assembly in the method of manufacturing a magnetic head according to the present invention is such that a platen 20 as a jig is heated by a heater 22 and a wax 23 is coated on a smooth surface 21 on the upper surface thereof. The wax 23 is applied to a predetermined thickness, and the wax 23 is melted.
A plurality of the assemblies 10 are placed in a line, and their rear end surfaces 2C, 8Ca, 8Cb face the smooth surface 21 of the platen 20, as shown in FIG. Up to this step, it is the same as the conventional fixing method described with reference to FIG. Next, as shown in FIG. 2C, a common weight 24 is placed on all the assemblies 10, and the weight is uniformly 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 melt viscosity of the molten wax 23 is increased. Next, as shown in FIG. 2D, when the molten wax 23 is not cured and the pressurization by the weight 24 is released, the distortion caused by the pressurization in the assembly 10 can be restored. When the melt viscosity becomes high, the weight 24 is removed and the pressurization is released (pressurized release).
Then, the natural cooling is continued in the non-pressurized state. After the molten wax 23 is completely hardened and the assembly 10 is firmly fixed to the surface plate 20, it is sent to the next grinding and polishing step, and the magnetic medium sliding surfaces 3A, 3B, 9A and 9B are ground and polished to a flat surface and finished flat. The wax used in the present invention is "Micron MW" manufactured by Nikka Seiko Co., Ltd. FIG. 2 shows its melt viscosity characteristics. When the wax is used, when the pressure is released, for example, when the temperature of the platen 20 reaches 70 ° C., the wax has a melt viscosity of 3 from a molten state.
When the temperature rises to 000 CP and the molten state is reached, the assembly 10 no longer changes its position on the platen 20 from front to back and left and right. However, the rear end surfaces 2C, 8 of the assembly 10
When Ca and 8Cb are twisted as shown in FIG. 6A, the rear end faces 2C, 8Ca and 8Cb are flattened as shown in FIG. The melt viscosity of wax 23 is 3,000
By releasing the pressurization in the state where the CP is high, the rear end surfaces 2C, 8Ca and 8Cb can return to the original state shown in FIG. 6A. Accordingly, the magnetic medium sliding surfaces 3A, 3B,
By grinding and polishing 9A and 9B (FIG. 4), a good magnetic head could be obtained, and the above problem could be solved. In the above embodiment, the magnetic head is constituted by a front core and a rear core, and the magnetic head element is reinforced by a guard member, and is constituted by a magnetic recording / reproducing head element and a magnetic erasing head element. Although the composite type magnetic head has been exemplified, the present invention is not limited to a magnetic head having such a configuration, and it is noted that the present invention can be widely applied to a method of manufacturing a magnetic head. 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 accuracy. Improved head-to-head squeal at the time of magnetic recording and reproduction, and improved contact between the magnetic head and the magnetic medium, thereby improving the electromagnetic conversion characteristics. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a process diagram showing a fixing method for 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 constituting a current magnetic head. FIG. 4 is an enlarged perspective view of a front core assembly incorporating the front core of the magnetic head element shown in FIG. 3; FIG. 5 is a process diagram showing a fixing method for fixing a front core assembly to a jig, for explaining a conventional method of manufacturing a magnetic head. FIG. 6 is a perspective view showing a rear end surface of the front core assembly for explaining an undesired phenomenon caused by a conventional method of fixing the front core assembly to the jig. [Description of Signs] 1 Magnetic head element 2A Front core 2B Rear core 2C Rear end face 3A 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 erase head element 6A Glass 8A Guard member 8B Guard member 8Ca Rear end surface 8Cb of guard member 8A Rear end surface 9A of guard member 8B Magnetic medium sliding surface 9B Magnetic medium sliding surface 10 Front core assembly 20 Surface plate (jig) ) 22 heater 23 molten wax 24 weight

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Eiji Yamauchi Inside, Sony Precision Magne Co., Ltd. 30 Sakai Kagano, Takae Niida, Nakata-cho, Tome-gun, Miyagi Pref. JP-A-63-245366 (JP, A) JP-A-5-159215 (JP, A) JP-A-6-251316 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 5/187-5/255 G11B 5/31-5/325 B24B 1/00-1/04 B24B 9/00-19/28

Claims (1)

(57) [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 platen. A plurality of the magnetic cores are placed on the surface plate, with their rear end faces facing the smooth surface of the surface plate, and then, in this state, the magnetic cores are
Pressing with a weight or the like from above the medium sliding surface, and cooling the molten wax in this pressurized state,
The melt viscosity before the molten wax is cured, the magnetic
When the strain caused by the pressurization of the core becomes high enough to be restored , the pressurization is released, and the wax is cooled in the non-pressurized state, and the wax is completely cured. And a step of polishing the medium sliding surface of the magnetic core after the magnetic core is fixed to the surface plate.