JPH04265505A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To suppress the occurrence of crack, fracture and coagulation and to suppress the deterioration of the characteristics of a thin soft magnetic film formed on the surface of a groove wall by reducing machining force and increasing a cooling effect for the abrasive grains of a grindstone and a bond used at the time of machining by means of a recessed part provided on the grinding surface of the grindstone, for finish machining and by means of the reduction of grounding area at the time of finish machining. CONSTITUTION:The finish machining is performed on the tilted surface of a groove 2 with an approximate V-shape which is formed on the surface of a circuit board by a rotary grindstone for rough machining, excluding the part adjacent part to the top part of the approximate V-shaped groove, by means of a grindstone 5 for finish machining which has finer abrasive grains than that of the grindstone for rough machining, whose grinding surface is formed in the shape obtained by cutting off the top part of the approximate V-shaped cross section, and which is provided with a part on its grinding surface.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic head having a high saturation magnetic flux density necessary for high-density magnetic recording and reproduction.

0002

2. Description of the Related Art With the increasing density of magnetic recording, magnetic recording media such as magnetic tapes are required to have a high coercive force, and magnetic heads are also required to have a high saturation magnetic flux density. Therefore,
A magnetic head chip is used in which a soft magnetic thin film having a high saturation magnetic flux density is provided on a substrate made of a non-magnetic material. As the substrate, a part of which becomes the sliding contact surface of the magnetic tape, a non-magnetic material such as ceramics or crystallized glass, which has excellent wear resistance, is selected.

In the manufacturing process of such a magnetic head, as shown in FIG. A soft magnetic thin film is formed on one inclined surface of each. Since the soft magnetic thin film is thus formed on the surfaces of the grooves 32, it is necessary to finish the surfaces of these grooves as smooth as possible. Therefore, conventionally, since the substrate 31 is made of a material that is difficult to process as described above, the grooves 32 are first formed on the substrate surface using a rotary grindstone for rough machining having a roughly V-shaped cross section, and then the grooves 32 are formed on the substrate surface. The second method involves finishing the surface of the grooves 32 formed by the rough-processing whetstone using a finishing-use rotary whetstone that has finer abrasive grain size than the processing whetstone and has the same cross-sectional shape as the rough-processing whetstone. Staged processing is being carried out.

0004

[Problems to be Solved by the Invention] However, when finishing grooves using the above-mentioned rotating grindstone for finishing, conventional methods tend to cause wear of the abrasive grains, softening of the binder, falling off of the abrasive grains, etc. As a result, cracks, cracks, adhesion, etc. occur in the grooves 32 formed on the substrate 31, resulting in a problem of deterioration of the characteristics of the soft magnetic thin film formed on the surface of the grooves. In other words, when processing with a finishing grindstone,
Since the microscopic contact area with the substrate 31 is larger than that of a rough processing grindstone with large surface irregularities, the overall contact area is also larger than during rough processing. As a result, even if the cutting speed during finish machining is reduced, the grinding process requires a large machining force. Further, along with such processing, a large amount of heat is generated, and this amount of heat is not sufficiently dissipated, causing a rise in temperature, resulting in the above-mentioned problems.

[0005]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the method for manufacturing a magnetic head of the present invention includes forming grooves having a substantially V-shaped cross section on the surface of a substrate using a rotary grindstone for rough processing, and then In a method for manufacturing a magnetic head in which a groove surface is finished by a finishing grinding wheel having a finer abrasive grain size than a roughing grinding wheel, the grinding surface of the finishing grinding wheel is cut from a substantially V-shaped cross section to an apex. The grinding surface is formed with a cut-out shape, and a recess is provided on the grinding surface, and the finishing grindstone is used to finish the sloped surface of the groove formed by the rough grinding wheel, excluding the vicinity of the apex. It is said that

[0006]

[Operation] In the method for manufacturing a magnetic head described above, the grinding wheel for finishing has a grinding surface with the apex removed from a substantially V-shaped cross section, and using this grinding wheel for finishing, Finish processing is performed on the sloped surface of the groove formed by the rough processing grindstone, except for the vicinity of the apex. Therefore, the area to be ground in contact with the substrate during this finishing process is smaller than in the past, so the finishing process is performed with smaller processing force. Furthermore, a recess is formed in the grinding surface of the finishing grindstone, and for example, the cooling liquid flowing into the recess is guided into the grinding region where the grindstone and the substrate come into sliding contact, thereby increasing the cooling effect. In this way, finishing machining can be performed with less machining force, and a more suitable cooling effect is generated to suppress temperature rise. Falling off, etc. is prevented.

[0007]

[Example] An embodiment of the present invention FIGS. 1 to 11
The explanation based on this is as follows.

When manufacturing a magnetic head, first, as shown in FIG. 2, a plurality of grooves 2 having a substantially V-shaped cross section are formed adjacent to each other on the surface of a substantially rectangular parallelepiped substrate 1 at a predetermined pitch A. It is formed in a shape that extends in parallel. The substrate 1 may be made of, for example, ceramics, since one surface of the substrate 1 becomes the sliding contact surface of the magnetic tape as described later.
Alternatively, a non-magnetic material with excellent wear resistance such as crystallized glass is selected. The substrate 1 made of such a non-magnetic material
Although it has excellent wear resistance, it is difficult to machine, so groove 2...
The formation is carried out using two types of rotating grindstones with different abrasive grain sizes and shapes through a two-step process of rough machining and finishing machining.

In the rough machining step, as shown in FIG. 3, groove machining is performed using a rotary grindstone 3 for rough machining whose outer peripheral edge has a V-shaped cross section and whose abrasive grain size is coarse. Next, the rough processing grindstone 3
Finishing of the groove is performed using a rotary grindstone 5 for finishing which has a finer abrasive grain size than the grinding wheel 5, but as shown in FIGS. It is formed in the shape of a V-shaped cross section with the apex removed, and both inclined grinding surfaces are provided with a plurality of groove-shaped recesses 6 radially arranged at appropriate intervals in the circumferential direction at the tips. ing.

[0010] With the finishing grindstone 5 having the above shape,
As shown in FIG. 1, the inclined surfaces (surfaces indicated by two-dot chain lines in the figure) of the grooves 2 formed by the rough processing grindstone 3 except for the vicinity of the apex portions are ground and finished.

Thereafter, as shown in FIG. 5, a soft magnetic thin film 7 is formed on one slope portion 2a of each groove 2 to a thickness corresponding to the track width of the magnetic head. Then,
As shown in FIG. 6, welded glass 8 is molded to fill each groove 2 from the surface, and then, as shown in FIG. The welded glass 8 is polished into a flat surface until the welded glass 8 is polished.

Next, as shown in FIG. 8, a coil winding window 9 and a coil winding fixing groove 10 are formed on the substrate 1, and
A film of gap material such as SiO2 is applied to the polished surface of the welded glass 8 to form a gap surface 12, and a one-sided core block 11 is produced.

After this, as shown in FIG.
2 are pressed and fixed facing each other, welded and joined,
It is formed as a core block 13. Next, this core block 13 is sequentially cut at a predetermined pitch B along the broken line in the figure to produce a magnetic head chip 14 as shown in FIG. Furthermore, as shown in FIG. 11, this magnetic head chip 14 is polished on the tape sliding surface (upper end surface in the figure) 16 on which the magnetic tape slides.
Coil winding 15 is applied to produce magnetic head 17.

In this way, in the above manufacturing method, the substrate 1
When grooves 2 are formed in the
Grooves 2 with a V-shaped cross section are formed using a rotary grindstone 5, which has a finer abrasive grain size than the rough processing grindstone 3, and whose grinding surface has a shape in which the apex is cut from the V-shaped cross section. , finishing processing is performed on the sloped surfaces excluding the apex portions of the grooves 2 formed by the rough processing grindstone 3.

[0015] Therefore, when performing finishing processing, the area to be ground in contact with the substrate is smaller than when processing the entire inclined surface of the rough processing groove, and the load on the finishing grindstone 5 during grinding is reduced. In addition, this finishing whetstone 5
Since the recesses 6 are radially provided on the grinding surface of the grinding surface, the cooling effect on the abrasive grains and the binder of the grinding wheel 5 is increased, and wear and drop of the abrasive grains, softening of the binder, etc. are suppressed. In this way, by reducing the grinding resistance of the finishing grindstone and the temperature rise, cracks, cracks, and adhesion occurring in the grooves 2 formed in the substrate 1 are suppressed, and the groove wall surfaces 2a...
Deterioration of the characteristics of the soft magnetic thin film 7 formed in the soft magnetic thin film 7 is prevented.

In the above embodiment, the substrate 1 is made of crystallized glass, ceramics, etc., but other non-magnetic materials such as photosensitive crystallized glass, and ferrite may also be used. The present invention can also be applied to a structure using magnetic materials such as.

[0017]

[Effects of the Invention] The method for manufacturing a magnetic head according to the present invention includes:
As described above, the grinding surface of the finishing grindstone, which has a finer abrasive grain size than that of the roughing grindstone, is formed by cutting off the apex from the approximately V-shaped cross section, and the grinding surface is provided with a recess. The finishing grindstone is used to finish the sloped surface of the groove, which has a substantially V-shaped cross section, formed by the rough processing grindstone, except for the vicinity of the apex.

Therefore, when finishing the groove, the contact area between the finishing grindstone and the substrate is smaller than before, and therefore, the processing force is reduced, and
Increases the cooling effect of the grindstone during processing. As a result, cracks, cracks, and adhesion on the groove wall surfaces are less likely to occur, and deterioration in the characteristics of the soft magnetic thin film formed on the groove wall surfaces is suppressed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing a finishing process of a groove formed on a substrate in an embodiment of the present invention.

FIG. 2 is a perspective view of the substrate in which grooves have been formed using a rotary grindstone for rough processing.

FIG. 3 is a cross-sectional view of a main part showing a step of forming grooves on the substrate using a rotary grindstone for rough processing.

FIG. 4 is a diagram showing the shape of the finishing grindstone, in which a is a partial sectional view and b is a front view.

FIG. 5 is a sectional view of a main part of a substrate in which a soft magnetic thin film is provided on one slope of the groove formed by a finishing grindstone.

FIG. 6 is a sectional view of a main part of a substrate in which the grooves are molded with fused glass.

FIG. 7 is a sectional view of a main part of a substrate in which the surface of the welded glass is polished into a flat surface.

FIG. 8 is a perspective view of a one-sided core block in which a coil winding window, a coil winding fixing groove, and a gap material are provided on the substrate.

FIG. 9 is a perspective view of a core block obtained by joining the two one-sided core blocks facing each other.

FIG. 10 is a perspective view of a magnetic head chip cut out from the core block.

FIG. 11 is a perspective view of a magnetic head obtained by subjecting the magnetic head chip to coil winding and tape sliding surface polishing.

FIG. 12 is a cross-sectional view of a main part of a substrate in which grooves are formed in a conventional example.

[Explanation of symbols]

1　　　　Substrate 2 Groove 3 Rough processing grindstone 5. Grindstone for finishing processing

Claims (1)

[Claims] 1. After forming a groove having a substantially V-shaped cross section on the surface of a substrate using a rotary grindstone for rough processing, the groove surface is polished using a rotary grindstone for finishing processing which has a finer abrasive grain size than the rotary grindstone for rough processing. In the method of manufacturing a magnetic head for finishing, the grinding surface of the finishing grindstone is formed in a shape with the apex removed from a substantially V-shaped cross section, and a recess is provided in the grinding surface, A method for manufacturing a magnetic head, comprising using a grindstone to finish an inclined surface of a groove formed by a rough processing grindstone, excluding the vicinity of the apex.