JPH04353606A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To reduce air bubbles generated in a glass member for reinforcement use by a method wherein a melting furnace is pressurized from a temperature which is lower than the softening temperature of a glass, the glass is melted and filled into a ground groove at the softening temperature of the glass for reinforcement use and a pressurization operation is held until the glass is solidified. CONSTITUTION:Track parts 1 are left in one ridge part each at core blocks 7, 8 which have been bonded by a bonding glass via gaps; ground grooves 6 are formed; a glass 2 for reinforcement use is melted and filled into the grooves 6. The obtained core blocks 7, 8 are bonded via a center spacer 9. When the glass 2 for reinforcement use is melted and filled, the pressure of a melting furnace is raised to atmospheric pressure or higher at a temperature which is lower than the softening point of the glass material 2 for reinforcement use. The glass 2 for reinforcement use is melted and filled into the ground grooves 6, and a pressurization state is maintained until the glass 2 is solidified. Since the pressure of the melting furnace is high at the melting operation of the glass 2 for reinforcement use in this manner, it is possible to restrain air bubbles from being generated from an adsorbed gas or the like. As a result, it is possible to prevent a gap part from being produced by the air bubbles.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to recording in a magnetic recording device,
The present invention relates to a method of manufacturing a magnetic head used for reproduction.

0002

2. Description of the Related Art In recent years, a method of manufacturing a magnetic head reinforced with glass has been developed in order to improve the abrasion resistance of the magnetic head and to prevent damage to magnetic recording media such as floppy disks made of soft resin. For example, JP-A-51-1356
No. 29 discloses a manufacturing method in which a melting furnace is pressurized with an inert gas after the reinforcing glass is melted.

A conventional method of manufacturing a magnetic head will be explained below. FIG. 2 is a perspective view of a conventional magnetic head. 1 is a track portion formed by grinding to a predetermined width; 2 is a reinforcing glass material portion filled in a grinding groove to reinforce the track portion 1; 3 is a gap portion; 4 is a bonding glass material;
5 is a magnetic head.

A method of manufacturing the conventional magnetic head constructed as described above will be described below. FIG. 3 is a manufacturing process diagram of a conventional magnetic head. In step (a), a ferrite core block 51 having a winding groove and a flat ferrite core block 52 are formed, and a glass thin film layer 31 forming a gap 3 is further formed at one end of the ferrite core block 51. After bonding the ferrite blocks 51 and 52 with the bonding glass material 4 in step (b), in step (c), a grinding groove 6 is formed on one edge of the bonded core block 53, leaving a track portion 1 with a predetermined width. In step (d), the grinding groove 6 is filled with a glass material to form the reinforcing glass material portion 2. In step (e), Er created in the same process as R/W block 7 created in this way.
The block 8 was bonded with resin or glass via a center spacer 10 made of a non-magnetic material such as CaTiO3, and then cut as shown by dotted lines and processed to manufacture a magnetic head.

[0005]

[Problems to be Solved by the Invention] However, in the above-mentioned conventional configuration, glass components remaining in the raw glass material, atmospheric gases drawn in during melting of glass in the furnace, or gas components adsorbed on the core block. is emitted at high temperatures, and the attached dust gasifies at high temperatures, causing bubbles to form and grow in the glass material, and after the bubbles escape, voids are formed. Furthermore, when this gap appears on the surface facing the magnetic medium, there is a problem in that the gap is clogged with floating dust and the like, leading to demagnetization of the recording signal. Furthermore, there are problems in that the magnetic recording medium is damaged, data is destroyed, and the magnetic head is clogged. Also,
Although the method disclosed in JP-A-51-135629 is effective in suppressing the growth of bubbles, it has the problem that it is impossible to prevent the generation of bubbles.

The present invention solves the above-mentioned conventional problems, and provides a high-quality magnetic head that suppresses the generation of bubbles in the reinforcing glass material and does not cause demagnetization of recording signals or damage to the magnetic recording medium. The purpose is to provide a manufacturing method for.

[0007]

[Means for Solving the Problems] In order to achieve this object, the magnetic head manufacturing method of the present invention increases the pressure of the melting furnace at a temperature lower than the softening temperature of the glass in the reinforcing glass melting and filling step. It consists of a process of increasing the pressure to above atmospheric pressure, then melting and filling the reinforcing glass material into the grinding groove while increasing the temperature, and lowering the temperature while maintaining the pressurized state at least until the reinforcing glass material is solidified.

[0008]

[Function] With this structure, when the reinforcing glass is melted, since the pressure in the melting furnace is high, it is possible to suppress foaming of adsorbed gas, etc., and as a result, it is possible to prevent the formation of voids due to air bubbles.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a state diagram showing the relationship between the molten state of reinforcing glass and pressure, temperature, and time in a method of manufacturing a magnetic head according to an embodiment of the present invention. The method of manufacturing the magnetic head of this embodiment will be described below with reference to the manufacturing process diagram of FIG.

In FIG. 3, conventional (a), (b), (
After going through each step of c), PbO52%, SiO235%
, 4.8% Na2O, 4.8% ZnO, etc., is placed in the grinding groove 6 and placed in the melting furnace using a jig. Next, as shown in FIG. 1, the ferrite core block 53 is replaced with an inert gas such as nitrogen or argon under reduced pressure at room temperature or at a relatively low temperature where the ferrite core block 53 is not adversely affected by oxygen in the air. After complete substitution, the pressure of the inert gas such as nitrogen is increased to approximately 6.5 atmospheres. Pressurization can be effective if the pressure is raised to above atmospheric pressure using a cylinder, booster pump, etc., and the higher the pressure, the greater the effect of preventing bubble formation, but consideration should be given to cost aspects such as equipment and safety management. In this case, economical and sufficiently excellent effects can be obtained even at a pressure of 3 to 10 atm. Then increase the temperature to 690℃
After the temperature was maintained for about 30 minutes for welding, the temperature was lowered under certain conditions, and the pressure was released when the furnace temperature reached 200°C. Thereafter, a magnetic head was obtained in step (e) in the same manner as in the conventional example.

Next, the reinforcing glass material part of the grinding groove of the magnetic head manufactured in this example was observed with a microscope, and the bubble diameter was 20.
The generation rate of bubbles larger than μm was determined for each 10 points, and the average thereof is shown in (Table 1).

(Comparative Example 1) A magnetic head was manufactured by the method disclosed in Japanese Patent Laid-Open No. 51-135629, and the reinforcing glass material portion was observed in the same manner as in the examples. The result (
Table 1) shows the results.

(Comparative Example 2) A magnetic head was manufactured according to a conventional method. Next, the reinforcing glass material portion was observed under a microscope in the same manner as in the examples. The results are shown in (Table 1).

[0015]

[Table 1]

As is clear from this (Table 1), the bubble diameter of the magnetic head obtained by the manufacturing method according to this example was 20 μm.
The generation rate of bubbles larger than m is only about 1/40 of the conventional example,
It can be seen that foaming of adsorbed gas, etc. is suppressed. Also, regarding the method of Japanese Patent Application Laid-Open No. 51-135629, Part 1
/10 or less was observed. This is considered to be because the gas foamed in the low temperature range expanded at high temperatures, resulting in a higher generation rate than in this example. The gas pressure of nitrogen gas lines commonly used in factories is 5 to 6 atmospheres, so if you use existing equipment as is, you can do it without using a boost pump, so you can mass-produce at a low cost. be able to.

[0017]

As described above, in the process of melting and filling reinforcing glass, the melting furnace is pressurized from a temperature lower than the softening temperature of the glass, and the grinding grooves are melted and filled at a temperature higher than the softening temperature of the reinforcing glass. However, by providing a step of maintaining the pressurized state at least until the glass solidifies, it is possible to reduce the generation of air bubbles in the reinforcing glass material part, and as a result, demagnetization of the magnetic head etc. does not occur. Moreover, it is possible to realize an excellent method of manufacturing a magnetic head that can mass-produce high-quality magnetic heads at low cost without damaging the magnetic recording medium.

[Brief explanation of drawings]

FIG. 1 is a state diagram showing the relationship between the molten state of reinforcing glass and pressure, temperature, and time in a method for manufacturing a magnetic head according to an embodiment of the present invention.

[Figure 2] Perspective view of a conventional magnetic head

FIG. 3: (a) Gap part formation process diagram (b) Core joining process diagram (c) Grinding groove formation process diagram (d) Reinforcing glass material part melt filling process diagram (e) Magnetic head cutting process figure

[Explanation of symbols]

1 Track section 2 Reinforcement glass material part 3 Gap part 4 Bonding glass material 5 Magnetic head core 6 Grinding groove 7 R/W block 8 Er block 9 Center spacer

Claims (1)

[Claims] 1. A step of forming a grinding groove by leaving a track portion of a predetermined width on one edge of a ferrite core block bonded with bonding glass through a gap, and melting a reinforcing glass material into the grinding groove. A method for manufacturing a magnetic head comprising a step of filling the ferrite core blocks obtained in the step and a step of bonding each ferrite core block obtained in the step through a center spacer, the step of melting and filling the reinforcing glass material with the reinforcing glass material. Pressure is raised in a melting furnace to atmospheric pressure or higher at a temperature lower than the softening point of the glass material for use in the process, and then the reinforcing glass material is melted and filled into the grinding groove while the temperature is raised, and the pressure is applied at least until the glass material for reinforcement is solidified. A method for manufacturing a magnetic head, comprising a step of lowering the temperature while maintaining the state.