JPH0229907A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To improve the production yield of the magnetic head by fixing a square bar-shaped work to constitute the core of the magnetic head by utilizing the slopes provided to the two side surfaces in the longitudinal direction intersecting with the surfaces to constitute the magnetic gap forming surfaces of the work then working the work. CONSTITUTION:The work 1 is previously so sloped that the inside angles theta between the two side surfaces in the longitudinal direction intersecting with the surface 2 to form the gap forming surface of the square bar-shaped work 2 to constitute the core and the surface 2 attains respectively 100-150 deg.. Leaf springs 5, etc., are screwed to this surface and the work is fixed onto a base plate by exerting a pressing force F thereto; thereafter, the work is subjected to working such as cutting or polishing. The components Fh of force in the transverse direction of the force F by the leaf springs, etc., act in the directions opposite to each other from both slopes, thus preventing the deviation of the work 1. The components Fv of force in the direction perpendicular to the base plate act to press the work 1 to the base plate, thus preventing the work 1 from floating from the base plate. The need for fixing the work to the base plate by using an adhesive agent, etc., is then eliminated and production yield is improved without receiving the influence of the fluctuation in the thickness of the adhesive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a magnetic head used in magnetic recording and reproducing devices such as VTRs and floppy disk drives, and in particular, during polishing and cutting of the magnetic gap forming surface. The present invention relates to a method for fixing a rectangular bar-shaped workpiece made of a magnetic material, which becomes the core of a magnetic head, to a base.

Conventional Δ1 Hill Conventionally, the method of fixing this type of workpiece to a base is to first heat the base to 80°C to 120°C, apply wax that melts at this temperature to the surface of the base, and then After pressing the workpiece, it is common practice to cool it and bond it, or to apply a -liquid or two-liquid adhesive to the surface of the base, and then press the workpiece to this surface and adhesively fix it.

In the conventional method of fixing a workpiece to a base as described above, an adhesive layer is interposed between the workpiece and the base, but the thickness of this layer is
Not only does a deviation of 1 μm to several tens of μ- occur each time adhesive fixing work is performed, but even within a single workpiece, even if well managed, deviations of 1 μm or more occur.
There are variations on the order of several μm.

If such variations exist, variations will occur in the magnetic gap length and track width, which play an important role in the electromagnetic conversion characteristics of the magnetic head, resulting in a significant reduction in manufacturing yield.

Figures 2a and 2b are cross-sectional views showing how the magnetic gap length varies within the workpiece. A workpiece 12 shown in FIG. 2a is fixed to a base 16 with an adhesive 15. adhesive 15
The thickness of the center part of the left and right ends of the workpiece 12 is ds and d, respectively.
s, d2, then ds < d2. It is different from d2>ds. When the surface 13 is polished with a flat polishing agent, each part of the surface 13 becomes the same plane, and as a result, 4.
Now, the center of the left and right edges are ta > t+ + t4
The thickness will be different from < ta. When workpieces with varying thicknesses are brought together as shown in Figure 2, the magnetic gap length is I! If gt<12g2.1g2>, the length will be different like g3, resulting in variation.

FIG. 3 is a cross-sectional view showing how the track width varies depending on the thickness of the adhesive layer.

A workpiece 12 is fixed to a base 16 with an adhesive 15. At this time, assume that the adhesive layer is thicker toward the right in the figure. Track defining grooves 14 are formed on the workpiece 12 using a dicer etc.
At this time, the height of the blade is the height from the surface of the base 18, so the bottom surface 1 of the groove 14 is
7's height from the base 16 hs, h2 + 113 is ht
: h2: hs, and as a result, the depth of the groove 14 becomes deeper as it goes to the right in the figure.

Therefore, the track width Tw11 TW2, Tv
3 is due to large variations as TWI > TV2 > TW3.

``The fixing method of the workpiece to the base of the present invention is such that the internal angles formed by the gap forming surface and the two longitudinal sides intersecting the gap forming surface of the rectangular bar shape are 100' to 15'', respectively.
This is done by making an inclination of 0° in advance and applying a pressing force to this surface by threading a leaf spring or the like in the direction of the base.

1. If the two longitudinal sides intersecting the gap forming surface of the workpiece are sloped in this way, and a force F is applied to these two slopes in a direction perpendicular to the slopes using a leaf spring, etc., as shown in Figure 4. Two component forces are generated: a force Fu that presses the workpiece against the substrate and a force Fh that pushes the workpiece sideways. The force pushing in the lateral direction acts in opposite directions from both slopes to prevent the workpiece from shifting, and the force perpendicular to the base acts in the direction of pressing the workpiece against the base, preventing the workpiece from lifting off the base. It acts to prevent Here, if the internal angle formed by the gap forming surface and the two slopes is smaller than 100°, the force Fu that presses the workpiece against the base will be small and the fixation will be insufficient.

On the other hand, if it is larger than 150", the workpiece installation interval becomes wide (
The number of workpieces fixed to the base will be reduced, which will reduce productivity.

1. Next, embodiments of the present invention will be described with reference to the drawings. FIGS. 1a to 1d are diagrams showing the main steps of the method for manufacturing a magnetic head of the present invention.

Figure 1a is a perspective view of a rectangular bar-shaped workpiece made of a metal oxide magnetic material such as Mn-Zn ferrite or a metal magnetic material such as sendust, which serves as the half core of the magnetic head, and 2 is the magnetic gap forming surface after processing. 3.4 is a slope, and the internal angle θ1=02 formed with the surface 2 is in the range of 100° to 150″.

FIG. 1 is a sectional view showing how the workpiece is fixed to the substrate 7. The workpiece formed as shown in Figure 1a is fixed to the workpiece fixing base 7 as shown in this figure.At this time, the distance between the workpiece and the top surface is larger than the distance Jt between the workpiece and the bottom surface. A strip-shaped leaf spring 5 having a width smaller than 2 and having a thickness thinner than the thickness tl of the workpiece is tightened with a screw 6 so that the end 5' of the leaf spring pushes against the slope of the workpiece, and is fixed on the workpiece. . At this time, it goes without saying that the height t2 between the tip of the screw 6 and the base must be smaller than the height tl of the workpiece by more than a machining substitute.

In Figure 1C, the base 7 on which the workpiece is fixed as shown in Figure 1 is turned over, placed on a polishing disk 8 coated with an abrasive such as diamond abrasive, and the center line 9 of the base 7 is set as the axis. FIG. In this step, the magnetic gap forming surface 2 is polished until it becomes a mirror surface.

Figure 1 d shows the base 7 on which the workpiece is fixed as shown in Figure 1.
FIG. 3 is a perspective view illustrating a process of fixing the disc to a cutting device such as a dicer and machining grooves such as track width defining grooves. 10 is
This is a track width defining groove cut and formed by a rotating blade 11 of a dicer. In this step, the track width of the magnetic head is defined.

The main parts of the manufacturing process using the magnetic manufacturing method according to the present invention have been explained above, but the detailed flow of the entire process can be found in the document "Industrial Materials, Vol. 36, No. 8 (June 1988 issue) J PP,
As shown in B2, the present invention can be applied to all of the fixing to the rectangular bar-shaped work base in each step.

As explained above, according to the magnetic head manufacturing method of the present invention, the workpiece is fixed to the base by pressing the slope of the workpiece with a spring without using adhesive or wax. Since it is fixed mechanically, the thickness of the adhesive layer is not affected by variations, and it is possible to reduce variations in the thickness of the workpiece after polishing and the track width after machining track width defining grooves.
Manufacturing yield is significantly improved.

[Brief explanation of the drawing]

FIGS. 1a to 1d are diagrams showing an embodiment of the method for manufacturing a magnetic head of the present invention. FIG. 1a is a perspective view of a workpiece made of a metal oxide magnetic material and serving as a core. FIG. 1 is a sectional view showing a method of fixing a workpiece to a base. FIG. 1C is a cross-sectional view showing how the magnetic gap forming surface of the workpiece fixed to the base is polished. FIG. 1d is a perspective view showing how a dicer is used to form track-defining grooves on a workpiece fixed to a base. FIGS. 2a, 2b and 3 are cross-sectional views of a workpiece showing a conventional method of manufacturing a magnetic head. FIG. 4 is a sectional view of a workpiece for explaining the workpiece fixing method of the present invention. Top... Work made of metal oxide magnetic material, 2... Magnetic gap forming surface, 3.4... Slanted surface, 5... Leaf spring, 5'... End of leaf spring Part, 6... Screw, 7... Base, 8... Polishing machine, 9... Center line of base, 10... Track defining groove, 11... Dicer blade, 12. ... Workpiece, 13... Polished surface, 14... Track regulation groove, 15... Adhesive groove. TomojlliS Shiichi Shikano (b) Ishibato Pass Figure 2

Claims (1)

[Claims] A workpiece made of a rod-shaped magnetic material that becomes the core of a magnetic head is tilted so that the internal angle of the surface that becomes the magnetic gap forming surface and the two longitudinal sides intersecting the surface are 100° to 150°, respectively. A method for manufacturing a magnetic head, characterized in that when polishing or cutting the gap forming surface, a pressing force is applied to both inclined surfaces to fix the bar-shaped workpiece to a base.