JPS63113818A - Manufacture of thin film magnetic head - Google Patents

Abstract

PURPOSE:To control the unevenness of a slider surface, and to set the flatness of a floating surface with high accuracy by controlling a working distortion of the slider surface containing the floating surface, and the reverse side opposed to the slider surface. CONSTITUTION:In a thin film magnetic head of a floating type, a slider surface 11 becomes a projecting surface or a recessed surface, by a difference between the sum of working surface distortion energies of floating surfaces 111, 112, and recessed surfaces 113-117, which are formed on the slider surface 11, and the working surface distortion energy of the reverse side 118. In case a working abrasive grain size of the slider surface 11 and a working abrasive grain size of the reverse side 118 are made different from each other, and working is executed by using a diamond abrasive grain tool, the working abrasive grain size of the recessed surfaces 113-117 is made larger than the working abrasive grain size of the reverse side 118. In such a way, between the recessed surfaces 113-117 and the reverse side 118, a working surface distortion by which the slider surface 11 becomes a projecting surface is generated. By utilizing this working surface distortion difference, the floating surfaces 111, 112 are allowed to have the flatness by the projecting surface.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a floating type thin film magnetic head, and the present invention relates to a method for manufacturing a floating type thin film magnetic head. By controlling the flatness, the flatness of the air bearing surface formed on the slider surface can be easily set to a target value with high accuracy.

Conventional technology A floating thin-film magnetic head uses dynamic pressure generated by the viscosity of air to create a small flying height between the magnetic recording medium and the magnetic recording medium when the medium moves relatively at high speed. It was designed to be maintained. Therefore, in the floating type thin film magnetic head, it is extremely important to set the flatness of the air bearing surface, which generates dynamic pressure, to a predetermined value.

FIG. 1 is a perspective view of a floating type thin film magnetic head.
One side of the substrate 1 made of ceramics such as 2O3-TiC is used as a slider surface 11 facing the magnetic recording medium, and strip-shaped air bearing surfaces 111 and 112 are formed parallel to each other at intervals on the slider surface 11. It has a structure in which thin film read/write elements 2 and 3 are attached to the side end faces. Floating surface 111
, 112, a lower concave surface 113, a concave surface 1
Concave surfaces 114 and 115 lower than 13 are formed,
Furthermore, concave surfaces 118 and 1 are provided on the outside of the air bearing surfaces 111 and 112.
17 is formed. By attaching and assembling this to a support spring or the like, a completed floating type thin film magnetic head can be obtained.

FIGS. 2A to 2C are diagrams showing the manufacturing process of a thin film magnetic head. First, as shown in FIG. 2(a), the head piece group 10 is
1, 1021. , , , 10n is cut out into a rod shape.

Next, as shown in FIGS. 2(b) and 2(C), necessary grooving is performed on the cut out head piece groups 101 to 10n.
A floating surface 111 is formed on the slider surface 11 by polishing or the like.
, 112 and the concave surfaces 113 to 117, the air bearing surfaces 111 , 112 , the concave surfaces 113 to 117 and the back surface 118 facing the slider surface 11 are polished using a diamond abrasive tool to improve the flatness of the slider surface 11. Set to the desired value.

Next, by separating and cutting each head piece group 101-1On (see FIG. 2(b)), the thin film magnetic head shown in FIG. 1 is obtained.

When performing the polishing step shown in FIG. 2(b), the following processing method has conventionally been used.

(a) The air bearing surfaces 111 and 112 are borised with Gouya powder of several IL11.

(b) The concave surfaces 113 to 117 and the back surface are processed with a rotary whetstone using a diamond abrasive grindstone of several tens of JLm.

Problems to be Solved by the Invention In the floating type thin film magnetic head, the air bearing surfaces 111, 1
12 and the magnetic recording medium, the air bearing surfaces 111 and 112 have 0 and i p-ra.
The following degree of flatness is required. However, concave surface 11
3 to 117 and the back surface 118 with a rotary grindstone using a diamond abrasive grindstone of several tens of tons.
It was difficult to suppress the flatness of Nos. 11 and 112 to 0.14 m or less.

Furthermore, when the flying height becomes smaller, generally in the case of a floating head, the flying surface must be convex to avoid head crashes, and the conventional processing method of machining the convex surface after machining the shape lengthens the process and increases costs. This was disadvantageous both in terms of performance and yield.

Means for Solving the Problems In order to solve the above-mentioned conventional problems, the present invention provides a method for improving the air bearing surface by controlling processing distortion of the slider surface including the air bearing surface and the back surface facing the slider surface. It is characterized by controlling flatness.

Function Generally, the shape of solids such as ceramics and metals changes due to surface strain and internal strain in addition to external forces.For example, Al2
O3 ceramics curves toward the side with less distortion based on the difference in processed surface strain between the first and back surfaces. Focusing on this point, the present invention controls the unevenness of the slider surface by controlling the processing distortion of the slider surface including the air bearing surface and the back surface facing the slider surface, and the flatness of the air bearing surface is reduced to 0.1 pm. The following values can be easily set. Furthermore, the air bearing surface can be easily set to a convex or concave surface.

As mentioned above, the thin-film head slider of a floating thin-film magnetic head is equipped with a substrate made of ceramics such as Al203-Tie, and is subject to processing distortion on the slider surface on the front surface of the substrate and on the back surface opposite the slider surface. By controlling the difference from the processing strain, it is possible to control the flatness of the air bearing surface on the slider surface.

In a general machining method using a diamond abrasive tool, one effective means to control machining distortion on the slider surface and the opposite back surface is to control the machining abrasive grain diameter on the slider surface and the machining abrasive grain on the back surface. This is to process the parts with different diameters. When machining using a diamond abrasive tool, the machining surface strain energy is correlated with the machining abrasive grain diameter.
Generally, the larger the diameter of the processed abrasive grains, the larger the processed surface strain energy. Therefore, by processing with different abrasive grain diameters on the slider surface and back surface, the machining surface strain on the slider surface and back surface can be controlled by the difference in machining abrasive grain diameter, and the machining surface strain difference The flatness of the air bearing surface on the slider surface can be controlled by making the slider surface concave or convex depending on the conditions. For example, if the abrasive grain diameter on the slider surface is made larger than the abrasive grain diameter on the back surface, the slider surface becomes a convex surface. On the contrary, if the abrasive grain diameter on the slider surface is made smaller than the abrasive grain diameter on the back surface, the slider surface becomes a concave surface.

In the thin film magnetic head shown in FIGS. 1 and 2(C), an air bearing surface 111 formed on the slider surface 11
, 112 and the concave surfaces 113 to 117, and the difference in the machining surface strain energy of the back surface 118, the slider surface 11 becomes a convex surface or 1F3' crosses the concave surface.

In view of the functionality of the thin film magnetic head, it is desirable that the slider surface 11 be a convex surface with a predetermined degree of flatness.

Further, although the processing conditions for the concave surfaces 113 to 117 and the back surface 118 are similar, the processing conditions for these and the air bearing surfaces 111 and 112 are different. Therefore, when machining is performed using a diamond abrasive tool by making the abrasive grain diameter on the slider surface 11 different from that on the back surface 118, the concave surfaces 113 to 11
By making the machining abrasive grain diameter of No. 7 larger than the machining abrasive grain diameter of the back surface 118, a machining surface strain difference is generated between the concave surfaces 113 to 117 and the back surface 11B with the slider surface 11 being a convex surface, and this machining surface Using the strain difference, the air bearing surface 111,
It is desirable that the convex surface 112 has flatness.

By the way, when the back surface 118 is processed with an abrasive grain size that is approximately half of the abrasive grain diameter used for processing the concave surfaces 113 to 117,
It was possible to make the air bearing surfaces 111 and 112 convex surfaces with a flatness of within 0.05 pm.

Next, the content of the present invention will be explained in more detail with reference to Examples.

Example 1 In a thin film magnetic head having the structure shown in FIG. 2(C), the air bearing surfaces 111 and 112 and the concave surface 11 were
3 to 117 and the back surface 118 were processed.

(al) Concave surface 114-11? Processing machine; Perimeter slicer grindstone; Metal pound diamond #320 circumferential speed;
4000m/min (bl) concave 113 processing machine; surface grinder grinding wheel; resin pound diamond #280 circumferential speed;
2000m/min (C1) Air bearing surface 111, 112 Processing machine; Polishing disk grinding wheel: m diamond powder circumferential speed for tin surface plate 1;
3Bm/min (d 1) FAAl2S 3 machine; Surface grinder grinding wheel; Resin pound diamond #800 circumferential speed;
1800 m/min Under the above-mentioned processing conditions, it was possible to obtain convex air bearing surfaces 111 and 112 with a flatness of within 0.05 pm.

Example 2 In a thin film magnetic head having the structure shown in FIG. 2(C), the air bearing surfaces 111 and 112 and the concave surface 11 were
3 to 117 and the back surface 118 were processed.

(C2) Concave surface 114-117 Processing machine: Periphery slicer grindstone; Metal pound diamond #320 circumferential speed;
4000m 7 minutes (b2) 4 sides 113 machining m; Surface grinder grindstone; Resin pound diamond #320 circumferential speed;
4000m/min (C2) Air bearing surface 111, 112 Processing machine; Boring wheel grinding wheel; Tin surface plate 1pm diamond powder circumferential speed;
38m/min (d2) Back side 118 Processing machine; Surface grinder grindstone; Resin pound diamond #400 circumferential speed;
2000 m/min Under the above-mentioned processing conditions, convex air bearing surfaces 111 and 112 with a flatness of 0.01 g could be obtained.

Effects of the Invention As described above, the method for manufacturing a thin film magnetic head according to the present invention improves the flatness of the air bearing surface by controlling processing distortion of the slider surface including the air bearing surface and the back surface facing the slider surface. Since the flatness of the air bearing surface formed on the slider surface is 0.1, LL
It can be easily set to a highly accurate value of II or less.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a floating thin film magnetic head, Figure 2 (a)
-(C) are diagrams similarly showing the manufacturing method. l...Guardian board 11-...Slider surface 111,
112...Flying surface 113-117...Concave surface 118・Fist II! A side No. 10 1QI NIIJll

Claims (3)

[Claims] (1) A method for manufacturing a thin film magnetic head, characterized in that the flatness of the air bearing surface is controlled by controlling processing strain on a slider surface including the air bearing surface and a back surface facing the slider surface. (2) Controlling the machining strain on the slider surface and the back surface by using a diamond abrasive tool and processing the slider surface with a different abrasive grain diameter and the back surface. Claim 1 characterized by
A method for manufacturing a thin-film magnetic head as described in 2. (3) The method for manufacturing a thin-film magnetic head according to claim 2, wherein the slider surface is processed with a processing abrasive grain diameter larger than that of the back surface.