JPS63275008A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve the reliability by forming a nonmagnetic layer to both ends at the outside of a track width of a magnetic head so as to prevent the production of a step difference and air bubbles to a sliding face of a recording medium and prevent the occurrence of a damage to the recording medium thereby extending the service life of the magnetic head. CONSTITUTION:Step difference parts 11, 12 are formed in parallel with the recording medium running direction by gouging processing at the outside of a track width Tw of a recording medium sliding face 8 and a nonmagnetic layer 13 is formed to a track width forming slot 2 at the inner side of the steps 11, 12. The nonmagnetic substance layer is made of a material such as Al2O3, SiO2 or high melting point glass, and the wear resistance and the melting point of the material are selected higher than that of a bonding glass 6 bonding the magnetic cores 3, 4 in such a way that no air bubbles exist therein. Thus, no local wear is caused between the magnetic cores 3, 4 and no air bubble is produced in the nonmagnetic layer 13, then the recording medium is not damaged and the bonding strength of the magnetic cores 3, 4 is improved and the service life is extended.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective 5 of the Invention (Field of Industrial Application) The present invention relates to a magnetic head mounted on a magnetic recording/reproducing device such as a video tape recorder (hereinafter referred to as VTR) or a floppy disk device.

(Prior Art) A magnetic head mounted on a magnetic recording/reproducing apparatus such as a VTR has conventionally been configured as shown in FIG. That is, a pair of magnetic cores 3.4 in which winding grooves 1 and track width forming grooves 2 are formed in directions perpendicular to each other are butted together with a gap holding film 5 interposed therebetween, and are integrally bonded by a bonding glass 6. and roughly sliced to a predetermined thickness A to obtain the magnetic helad core 7. In such a magnetic held core 7, the recording medium sliding contact surface 8 on which a recording medium such as a magnetic tape (not shown) comes into sliding contact has the above-described grooves in the vicinity of the gap holding film 5 of the track width T and the gear book Q. Bonded glass 6 is arranged.

This bonding glass 6 is made of low melting point glass in order to improve the abrasion resistance of the sliding contact surface with the magnetic recording medium and to firmly bond the magnetic core 3゜4. As shown in FIG. 9, there was a problem in that bubbles 9 were generated in the bonded glass 6. The generation of the bubbles 9 may damage the recording medium or cause the bonding strength between the cores 3 and 4 to become incomplete. Furthermore, since low-melting glass is used, the amount of wear of the bonding glass 6 on the recording medium sliding surface 8 is less than that of the magnetic core 3°4.
As shown in FIG. 10, the recording medium sliding contact surface 8
A step difference ΔH occurs. As a result, there is a problem in that the depth D of the magnetic gap decreases quickly and the life of the magnetic head is shortened.

In order to solve this problem, it is possible to use high melting point glass with high wear resistance as the bonding glass 6 that joins the magnetic cores 3 and 4, but in this case as well, the generation of air bubbles 9 is unavoidable. Ta. In order to suppress the generation of bubbles 9,
If the temperature range when bonding the magnetic cores 3.4 is set to a high temperature, the bonding glass 6 will penetrate into the gap holding film 5, causing a change in the gap length Q, as shown in FIG. , 4, there is a problem in that stress due to the difference in thermal expansion coefficient of each material of the gap holding film 5 and the bonding glass 6 is generated at the interface of each material, and cracks 10 are generated in the magnetic cores 3 and 4.

(Problems to be Solved by the Invention) The present invention solves the problems of conventional magnetic heads, such as bubbles in the glass portion of the sliding contact surface of the recording medium and uneven wear of the glass portion due to low-melting glass bonding. The purpose of the present invention is to provide a magnetic head that solves the problems of gap length fluctuations and cranks occurring in the magnetic core due to melting point glass bonding, and that can extend the service life without damaging the recording medium. .

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a magnetic head in which a pair of magnetic cores are joined and integrated via a gap holding film. A nonmagnetic layer with high wear resistance is formed on both outer ends of the track width formed by the gap holding film.

(Function) According to the above structure, a highly wear-resistant non-magnetic layer is formed at both ends of the track width of the recording medium sliding surface, so uneven wear does not occur between it and the magnetic core. There isn't. Furthermore, since bubbles can be prevented from being generated in the nonmagnetic layer, the recording medium is not damaged and the bonding strength of the magnetic core is improved.

(Embodiment) An embodiment of the magnetic head according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In the figure, parts that are the same or equivalent to those of the conventional example shown in FIG. 8 are designated by the same reference numerals, and their explanation will be omitted. The feature of this embodiment is that a stepped portion 11.12 is formed on the outside of the track width T of the recording medium sliding contact surface 8 by edging process in parallel to the recording medium running direction.
Track width forming grooves 2 inside these stepped portions 11° 12
The point is that a non-magnetic layer 13 having high wear resistance and a high melting point is formed. This non-magnetic layer 13 is, for example, A1203',
S f 02 .

It is made of high melting point glass, etc., and has higher wear resistance and melting point than the bonding glass 6 that bonds the magnetic core 3゜4.
Moreover, it is formed so that there are no air bubbles inside.

Next, a method of manufacturing the magnetic helad core 14 according to this embodiment will be explained with reference to FIGS. 2 to 7. First, as shown in FIG. 2, a plurality of track width forming grooves 2 having a substantially V-shaped cross section are formed in parallel in the magnetic core block 15. As shown in FIG. Next, as shown in FIG. 3, on the track width forming groove 2 of the magnetic core block 15 and the magnetic core facing surface 15a on the side of the track width forming groove 2, a nonmagnetic layer 13 with good wear resistance and no bubbles, For example, Al1203.5i02, high melting point glass, or the like is formed by sputtering, vapor deposition, plating, or the like. After that, as shown in FIG. 4, the opposing surface i5 of the magnetic core block 15 is
A is mirror-finished by lapping or the like, and the non-magnetic layer 13 on the opposing surface 15a is removed, leaving only the non-magnetic layer 13 in the track width forming groove 2. Next, as shown in FIG. 5, winding grooves 1 and glass grooves 16 of predetermined dimensions and shapes are formed in the direction perpendicular to the track width forming grooves 2 on this opposing surface 15a, and then a non-magnetic A gap holding film 5 made of solid material is formed by sputtering, vapor deposition, or the like. Next, as shown in FIG. 6, the pair of magnetic core blocks 15 and 17 made as described above are butted against each other at a position where the multi-grooves 1 and 16 are aligned so that the non-magnetic layer 13 does not melt. A low-melting glass 18 having a processing temperature within the range is inserted into the winding groove 1 and the glass groove 16, and heated and bonded to form a core block 19 as shown in FIG. Next, dotted line 20 in Figure 7
At the position shown in , the recording medium 1g of the core block 19
The low-melting point glass embedded portion 21 of the contact surface 8 is removed by grinding, and then sliced at the position indicated by the dotted line 22, and the sliding contact surface 8 is roughly cylindrical polished to form the magnetic held core 14 shown in FIG. form.

Next, the operation and effects of the magnetic head according to this embodiment will be explained. Since the non-magnetic layer 13 filled in the track width regulating groove 2 exposed on the recording medium sliding surface 8 has high wear resistance and is free of bubbles, a step may not occur between the sliding surface 8 and the regulating groove 2. The magnetic gap depth can be prevented from decreasing. It is also possible to prevent damage to the recording medium and deterioration of bonding strength due to the generation of bubbles. Moreover, magnetic cores 3 and 4
Since the bonding glass 6 for bonding the magnetic cores 3 and 4 is a low melting point glass, the bonding temperature can be kept low, and the bonding glass 6 can be prevented from penetrating the gap holding film 5 and changing the gap length q. It can also prevent cracks from forming. As a result, the life of the magnetic head can be extended and reliability can be improved.

In the embodiment described above, the recording medium sliding contact surface 8 has stepped portions 11, 1.
2, the recording medium is a magnetic tape, and the width of the nonmagnetic layer 13 is smaller than the width of the magnetic tape.
If the distance between the outer sides is long, the stepped portions it, 12 may be omitted.

[Effects of the Invention] As described above, according to the present invention, a non-magnetic layer with high wear resistance and no bubbles is formed at both ends outside the track width of the magnetic head, so that there are no steps or bubbles on the recording medium sliding surface. It is possible to prevent the occurrence of damage to the recording medium, and it is possible to extend the life of the magnetic head and improve its reliability.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the magnetic head according to the present invention, FIGS. 2 to 7 are perspective views showing the manufacturing process of the magnetic head shown in FIG. 1, and FIG. 8 is a conventional magnetic head. FIGS. 9 to 11 are perspective views showing problems with conventional magnetic heads. 3.4...Magnetic core 5...Gap holding film 6...Bonding glass material 8...Recording medium sliding contact surface 9...Bubble it, 12...Step portion 13...Non Magnetic layer T oath...Track width agent Patent attorney Noriyuki Chika Yudo Hiroshi UjiFigure 1Figure 2Figure 3Figure 4Figure 5Figure 8Figure 9

Claims (2)

[Claims] (1) In a magnetic head in which a pair of magnetic cores are integrally bonded via a gap holding film, a non-magnetic layer with high wear resistance is provided at both outer ends of the track width formed by the gap holding film. What is claimed is: 1. A magnetic head characterized in that a glass material having a low melting point is formed on both outer ends of the magnetic head. (2) The magnetic head according to claim 1, wherein a stepped portion is formed on the recording medium sliding surface on the outside of the track width.