JPH06251316A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To manufacture a magnetic head in which flatness of opposed surfaces of a medium is enhanced, which has stable magnetic conversion characteristics, with which high density recording can be performed and contributes to improving the service lives of the medium and the head itself. CONSTITUTION:Slider members 2, 3 constituting a slider are glass bonded to a magnetic head core 1, opposed surfaces 1a, 2a, 3a of then are ground, and then grooves 4 are formed in back surfaces of the media. In this case, the flatness of the surfaces 1a, 2a, 3a of the media may be set to 30 deg.nm or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a floppy disk,
The present invention relates to a method of manufacturing a magnetic head mounted in a drive magnetic head device.

[0002]

2. Description of the Related Art Since a disk-shaped floppy disk is relatively easy to handle and can record a large capacity of signals, it is widely used as an external storage device for various computers, word processors and the like.

When recording / reproducing information on / from the floppy disk, as a matter of course, the floppy disk is rotated and the magnetic head is brought into contact with the floppy disk to record / reproduce information. However, since the floppy disk has flexibility, it easily vibrates due to rotation,
The magnetic head cannot make stable and reliable contact with the floppy disk. Therefore, a magnetic head device for a floppy disk drive, which is constructed so that the floppy disk is sandwiched by magnetic heads, is used so that the magnetic head is brought into stable and reliable contact with the floppy disk. That is, in the above-mentioned magnetic head device for a floppy disk drive, a magnetic head core is supported by a slider having a flat medium facing surface to form a magnetic head, and the magnetic head is supported by a support through a spring member such as a gimbal. By supporting the floppy disk so as to sandwich it while applying a load, stable and reliable contact between the magnetic head and the floppy disk is achieved.

The magnetic head has a shape as shown in FIG. 12, for example. As shown in the figure, the magnetic head includes a slider member 1 having two magnetic head cores 11.
It is formed so as to be sandwiched by 2 and 13, and the medium facing surface 12a of one slider member 12 is
A groove portion 12b which is an air groove is formed. Each medium facing surface 11a, 12a, 13a is ground, and a groove 14 for coil winding is formed on the back surface thereof, and a coil (not shown) is wound. In addition, in the gap of the groove portion 14, a leg portion 15 which will be used later as a fixing portion to the gimbal is formed.

Such a magnetic head is manufactured as follows. First, a magnetic head core having a magnetic gap is joined so as to be sandwiched by two slider members, and a groove portion is formed on the back side of the medium facing surface of the magnetic head core and the slider member to form a groove portion for coil winding.
Then, surface grinding is performed on the medium facing surface of the magnetic head core and the slider member, and a coil is wound around the groove to obtain a magnetic head as shown in FIG.

[0006]

In recent years, there has been a demand for higher capacity of a floppy disk as a medium and improvement of a magnetic head device for a floppy disk drive, which is a device, and a high capacity from the current 2 MB to 4 MB has been demanded. Is required. In the above-mentioned floppy disk drive magnetic head device, it is required to improve the flatness of the medium facing surface of the magnetic head particularly for the purpose of stabilizing the magnetic conversion characteristics. Specifically, the flatness of the medium facing surface of the 2 MB floppy disk drive magnetic head device was about 150 nm, but the flatness of about 30 nm is required for the 4 MB floppy disk drive magnetic head device. Therefore, in the medium facing surface polishing treatment, the medium facing surface is grinded to a surface having a flatness of about 30 nm.

However, when mounting such a magnetic head in a floppy disk drive magnetic head device, there is a problem that the flatness of the medium facing surface is impaired. The above problem occurs as follows.
When the magnetic head is mounted on the floppy disk drive magnetic head device, it is supported by the support through the spring member such as a gimbal as described above. At this time, the magnetic head is fixed to the gimbal with an adhesive, but the contraction of the adhesive in the process of adhering to the gimbal impairs the flatness of the medium facing surface of the magnetic head.

As the above-mentioned adhesive, an epoxy resin or an ultraviolet curable resin is generally used. However, these adhesives are prepared by dissolving a resin in a solvent. Since the solvent volatilizes and cures, the adhesive adheres by curing. The volume of the agent shrinks.

For example, the volume contraction rate of a certain ultraviolet curable resin at the time of curing is obtained as follows. When the non-volatile component coefficient A is 1.00, the liquid specific gravity B is 1.03, and the curing specific gravity C is 1.12, the volume shrinkage ratio D is calculated by the following equation. D = {1- (AB / C)} * 100 = {1- (1.00 * 1.03 / 1.12)} = 8.04 That is, in the said ultraviolet curable resin, it is 8. at the time of hardening.
A volume contraction of 04% occurs.

Therefore, when the magnetic head is fixed to the gimbal with such an ultraviolet curable resin, the magnetic head receives a force due to the contraction of the ultraviolet curable resin during curing during the bonding process. For example, when the magnetic head composed of the magnetic head core 11 and the slider members 12 and 13 is fixed to the gimbal 16 by the ultraviolet curable resin 17 as shown in FIG. A force in the direction indicated by an arrow P ₂ in the figure, which is generated by contraction of the ultraviolet curable resin 17 during curing, is applied to the portion 15. That is, the magnetic head has medium facing surfaces 11a, 12a, 13a.
A force will be applied in the direction of bending. Therefore, a warp occurs in the medium facing surface of the magnetic head portion after the gimbal is fixed, and the medium facing surface has a convex shape, impairing the flatness thereof. The same is true when an epoxy resin is used as the adhesive, and the shrinkage of the resin during curing causes the medium facing surface of the magnetic head to have a convex shape, impairing its flatness.

When the medium facing surface of the magnetic head has a convex shape and its flatness is lowered, the reproduction output waveform is not constant and the computer or the like cannot read the signal, resulting in a read error. A defect occurs and it is impossible to achieve stabilization of the magnetic conversion characteristics. Further, the convex surface of the medium facing surface is not preferable because it causes inconveniences such as a decrease in product life of the medium and the magnetic head due to scratches on the medium surface.

Therefore, it has been attempted to prevent the change of the shape of the medium facing surface of the magnetic head by changing the kind and the coating amount of the adhesive to suppress the generation of force due to the contraction of the adhesive during curing. However, because there are variations in the amount of adhesive applied,
It is impossible to completely suppress the change in the shape of the medium facing surface of the magnetic head.

On the other hand, the above-mentioned magnetic head device for a floppy disk is also required to be downsized, which is also required to improve the flatness of the medium facing surface of the magnetic head. That is, the magnetic head has a structure as shown in FIG. 12, and the groove portion 1 provided for winding the coil is provided.
Since the depth D of 4 cannot be made too small for the convenience of coil winding, it is necessary to reduce the thickness W of the medium facing portion 18 in order to reduce the size. At this time,
Medium facing surfaces 11a, 12a, 13a of the medium facing portion 18
If the flatness is too low, the strength of the magnetic head cannot be secured and the product life of the magnetic head is shortened, which is not preferable.

Therefore, the present invention has been proposed in view of the actual situation of the related art, and it has a high flatness of the medium facing surface, has a stable magnetic conversion characteristic, and can cope with a high recording density. An object of the present invention is to provide a magnetic head manufacturing method for manufacturing a magnetic head capable of improving the product life of the head.

[0015]

As a result of intensive studies by the present inventors in order to achieve the above-mentioned object, as a result, a shape that cancels the deformation that occurs when the medium facing surface of the magnetic head is fixed to the gimbal is cancelled. By pre-processing and fixing to the gimbal, the flatness of the medium facing surface can be increased, stable magnetic conversion characteristics can be achieved, high recording density can be supported, and the product life of the medium and magnetic head can be improved. It has been found that it is possible to manufacture a possible magnetic head.

That is, according to the method of manufacturing a magnetic head of the present invention, after the slider and the magnetic head core are glass-bonded,
Surface-grinding is performed on the medium facing surface of the slider and the magnetic head core, and grooves are formed on the back surface side of the medium facing surface.

Further, according to the present invention, in the above-mentioned magnetic head manufacturing method, the flatness of the medium facing surface is 30 nm.
It is characterized by the following.

[0018]

In the method of manufacturing a magnetic head of the present invention, after the slider and the magnetic head core are glass-bonded, the medium facing surface of the slider and the magnetic head core is subjected to surface grinding, and a groove is formed on the back side of the medium facing surface. Therefore, it can be preliminarily formed into a shape that cancels out the deformation occurring in the medium facing surface of the slider and the magnetic head core when the slider and the magnetic head core are fixed to the gimbal in the subsequent step.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described below with reference to the drawings.

First, FIG. 1 shows a magnetic head manufactured by the method of manufacturing a magnetic head of this embodiment. As shown in the drawing, the magnetic head has a shape in which a magnetic head core 1 is sandwiched between two slider members 2 and 3, and one slider member 2 has a medium facing surface 2a.
A groove portion 2b, which is an air groove, is formed in the.
Further, each medium facing surface 1a, 2a, 3a is subjected to polishing, and the back surface thereof has a groove portion 4 for coil winding.
Is formed and a coil (not shown) is wound. In addition, a leg portion 5 which will be used later as a fixing portion to a gimbal which is a spring member is formed in the gap of the groove portion 4.

Next, a method of manufacturing the magnetic head of this embodiment will be described in the order of steps. First, as shown in FIG. 2, a magnetic head core 1 having a magnetic gap is attached to two slider members 2 and 3.
Bonding is carried out so as to be sandwiched by, and a bonded article as shown in FIG. 3 is obtained. At this time, a groove portion 2b, which is an air groove, is provided on the medium facing surface 2a of one slider member 2 of the joined object, and the magnetic head core 1 is provided on the other slider member 3 of the magnetic head core 1.
It is in a state of being mounted on the slider rail 3b.

Then, as shown in FIG. 4, the medium facing surfaces 1a, 2a, 3 of the magnetic head core 1, slider members 2, 3 are shown.
Surface grinding such as surface grinding and polishing is performed on a.
These surfaces are finished into smooth surfaces having a flatness of 20 to 30 nm.

Next, as shown in FIG. 5, the medium facing surfaces 1a, 2a of the magnetic head core 1, the slider members 2, 3,
A groove is formed on the back surface of 3a to form a groove portion 4 for winding a coil, and a coil (not shown) is wound to obtain a magnetic head as shown in FIG. At this time, the leg portion 5 is formed in the gap between the groove portions 4.

When the magnetic head manufactured in this manner is mounted on the floppy disk drive magnetic head device, as shown in FIG. 6, the leg portion 5 formed together with the formation of the groove portion 4 is used as a fixing portion for ultraviolet curing. The resin 7 is fixed to the gimbal 6 and mounted on the floppy disk drive magnetic head device.

At this time, as described above, the hardening of the ultraviolet curable resin 7 as an adhesive causes the leg portion 5 of the magnetic head to contract due to the contraction of the ultraviolet curable resin 7 at the time of curing.
A force is applied in the direction indicated by ₁ . That is, a force is applied to the magnetic head in the direction of bending the medium facing surfaces 1a, 2a, 3a. However, in the magnetic head manufactured by the method of manufacturing the magnetic head of this embodiment, the medium facing surfaces 1a, 2a, 3a do not warp.

In the conventional magnetic head manufacturing method,
A groove for coil winding is formed on the back surface of the medium facing surface of the magnetic head core and the slider member, and the medium facing surface is made a flat surface and then fixed to the gimbal. Due to the sticking to the gimbal, it receives a force and becomes a convex surface.

On the other hand, in the method of manufacturing the magnetic head of the present embodiment, the medium facing surface of the magnetic head core and the slider member is made flat as described above, and the groove for coil winding is formed on the back surface of the medium facing surface. After that, it is fixed to the gimbal. At this time, the magnetic head core and the slider member are released from the internal strain by the surface grinding of the medium facing surface while the internal strain is generated due to the joining of the magnetic head core and the slider member, and the subsequent groove formation. That is, FIG.
Magnetic head core 1 and slider members 2 and 3 as shown in FIG.
The legs 5 of the medium are spread outward, and the medium facing surface 1
A, 2a, 3a will be concave. Therefore,
When the magnetic head having such a concave-shaped medium facing surface is fixed to the gimbal, the concave-shaped medium facing surface is flattened by the force in the direction of bending the medium facing surface as described above, and the medium facing surface is No warpage occurs.

Therefore, the flatness of the medium facing surface of the magnetic head manufactured by the conventional magnetic head manufacturing method and the magnetic head manufactured by the magnetic head manufacturing method of this embodiment were actually measured.

A non-contact three-dimensional roughness / shape measuring device of a laser light source is used as a measuring device, and the medium facing surface is divided into several line regions for measurement, and the highest point in the entire range of the medium facing surface is measured. The difference between the low points was defined as the flatness. In the magnetic head manufactured by the conventional method for manufacturing a magnetic head, when the magnetic head is completed, that is, the flatness immediately after the surface grinding of the medium facing surface and the flatness when fixed to the gimbal are measured, The respective results are shown in FIGS. On the other hand, in the magnetic head manufactured by the method of manufacturing the magnetic head of the present embodiment, the flatness at the time of surface grinding of the medium facing surface, at the time of forming the groove portion (at the completion of the magnetic head), and at the time of fixing the gimbal was measured, and the respective results were obtained. Are shown in FIGS. The charts of FIGS. 7 to 11 show the measurement results of the surface state in the one-line region of each sample, and in each figure, the numerical value showing the flatness of the entire surface is shown, and the shape thereof is also shown.

From the results of FIGS. 7 and 8, in the magnetic head manufactured by the conventional method of manufacturing a magnetic head, a flat medium facing surface having a flatness of 30 nm or less can be obtained when the magnetic head is completed, but it is fixed to the gimbal. It was confirmed that the deformation caused a flat surface having a flatness larger than 30 nm. On the other hand, in the magnetic head manufactured by the method for manufacturing a magnetic head of the present embodiment, first, a flat medium facing surface having a flatness of 30 nm or less is obtained by surface grinding, and then a groove is formed on the back surface of the medium facing surface. It was confirmed that the medium facing surface was formed into a concave surface, and a flat medium facing surface having a flatness of 30 nm or less was obtained again by the subsequent fixing to the gimbal.

Further, the occurrence rate of modulation failure when these magnetic heads were used in a 4 MB floppy disk drive magnetic head device was investigated, and the present embodiment having a flat medium facing surface with a flatness of 30 nm or less was carried out. In the magnetic head manufactured by the manufacturing method of the example magnetic head, the magnetic head manufactured by the conventional manufacturing method of the magnetic head having the medium facing surface having the flatness of 30% or less is 5% or less. , 30
Was 50%. That is, the magnetic head manufactured by the method of manufacturing a magnetic head of the present embodiment has a flat medium facing surface having a flatness of 30 nm or less, and thus has a low occurrence rate of poor modulation and stable magnetic conversion characteristics. Was confirmed.

[0032]

As is apparent from the above description, in the method of manufacturing a magnetic head of the present invention, after the slider and the magnetic head core are glass-bonded, the medium facing surfaces of the slider and the magnetic head core are surface-ground. Since the groove is formed on the back surface side of the medium facing surface, it is preformed in a shape that cancels out the deformation of the slider and the magnetic head core, which occurs in the medium facing surface when the spring member is fixed to the gimbal in a later step. It is possible to keep it. Therefore, it is possible to obtain a flat medium facing surface after being fixed to the gimbal, stabilize the magnetic conversion characteristics, and form a magnetic head compatible with high density recording. Further, since the flat medium sliding surface can be obtained, the medium is not damaged and the product life of the medium and the magnetic head can be improved. Furthermore, since it is possible to form a flat medium facing surface, it is possible to achieve miniaturization.

Further, in the method of manufacturing a magnetic head of the present invention, a higher effect can be obtained by setting the flatness of the medium facing surface to 30 nm or less.

[Brief description of drawings]

FIG. 1 is a perspective view showing a magnetic head manufactured by a method of manufacturing a magnetic head to which the present invention is applied.

FIG. 2 is a perspective view showing a method of manufacturing a magnetic head to which the present invention is applied, in the order of steps, and showing a step of joining a magnetic head core and a slider member.

FIG. 3 is a perspective view showing a state in which a magnetic head core and a slider member are joined together.

FIG. 4 is a perspective view showing a step of performing surface grinding on the medium facing surfaces of the magnetic head core and the slider member.

FIG. 5 is a perspective view showing a step of forming a groove on the back surface of the medium facing surface of the magnetic head core and the slider member.

FIG. 6 is a schematic perspective view of essential parts showing a state in which a magnetic head manufactured by a method of manufacturing a magnetic head according to the present invention is fixed to a gimbal.

FIG. 7 is a chart showing a surface state of a medium facing surface of a magnetic head manufactured by a conventional magnetic head manufacturing method when the magnetic head is completed.

FIG. 8 is a chart showing a surface state of a medium facing surface when a magnetic head manufactured by a conventional magnetic head manufacturing method is fixed to a gimbal.

FIG. 9 is a chart showing the surface state of the medium facing surface of the magnetic head manufactured by the method of manufacturing a magnetic head according to the present invention during polishing of the medium facing surface.

FIG. 10 is a chart showing a surface state of a medium facing surface when a groove is formed in a magnetic head manufactured by a method of manufacturing a magnetic head to which the invention is applied.

FIG. 11 is a chart showing a surface state of a medium facing surface when a magnetic head manufactured by a method of manufacturing a magnetic head according to the present invention is fixed to a gimbal.

FIG. 12 is a perspective view showing a magnetic head manufactured by a conventional method of manufacturing a magnetic head.

FIG. 13 is a main part schematic perspective view showing a state in which a magnetic head manufactured by a conventional magnetic head manufacturing method is fixed to a gimbal.

[Explanation of symbols]

 1 ... ・ Magnetic head core 2, 3 ・ ・ Slider member 4 ・ ・ ・ ・ Groove 5 ・ ・ ・ ・ Legs 6 ・ ・ ・ ・ Gimbal 7 ・ ・ ・ ・ ・ ・ UV curing resin

Claims (2)

[Claims] 1. A magnetic head characterized in that a slider and a magnetic head core are glass-bonded, the medium facing surface of the slider and the magnetic head core is surface-ground, and then a groove is formed on the back side of the medium facing surface. Manufacturing method. 2. The method of manufacturing a magnetic head according to claim 1, wherein the flatness of the medium facing surface is 30 nm or less.