JPH0411303A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve joint strength and magnetic characteristics by butting and joining a pair of right and left core half bodies against and to each other, forming a winding groove and back groove respectively on either butt surface of a pair of the core half bodies and expanding the width of the grooves near the end on the outer peripheral side of the core of the back groove to a stepped shape. CONSTITUTION:The width of the part 6b on the outer peripheral side of the core of the back groove 6 is set wider than the width in the part 6a on the winding groove 6 side and is formed to the stepped shape. A joining material is, therefore, surely packed into the narrow width part of the back groove 6 contributing strongly to the joining of the core half bodies. A large difference is not generated in the joint strength even if the packing to the broad width part of the back groove 6 is insufficient as the packing amt. of the joining material changes. The butt surfaces are formed over the entire surface in the transverse direction of the thickness of the cores and, therefore, the butting area is assured. The joint strength and magnetic characteristics are improved in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head provided in a magnetic recording/reproducing device such as a video tape recorder.

[Conventional technology]

2. Description of the Related Art Magnetic recording and reproducing devices such as video tape recorders are equipped with magnetic heads that record and reproduce information on and from recording media such as magnetic tapes.

FIG. 9 shows an example of a conventional magnetic herad chip 1. As shown in FIG. In the figure, a pair of core halves 2 made of ferrite etc.
．． 3 are butt-jointed with molded glass or the like.

Further, a winding groove 5 is formed on the abutting surface of one core half 2 on the recording medium sliding surface 4 side formed in an R shape, and a back groove 6 is formed on the opposite side. Also, track width regulating grooves 7 are provided on both sides between the winding groove 5 and the recording medium sliding surface 4.
are provided, and a gap film (not shown) is formed on the core abutting surface between these grooves 7.

The conventional back groove 6 was formed parallel to the abutting surfaces.

In addition, as shown in FIG. 10, in another conventional magnetic helical core, the track width regulating groove 7 is extended as it is on both sides of the abutting surface to form a pack gap bonding groove.

[Problem to be solved by the invention]

The magnetic helad tip l shown in FIGS. 9 and 10 is a finished product by slicing the outer periphery into predetermined dimensions. Here the ninth
When slicing the magnetic head chip l shown in the figure, the first
If the back groove 6 is sufficiently filled with glass 8 as shown in FIG. 1(a), there is no problem even if the glass is sliced along the line A. However, as shown in FIG. 11(b), if the amount of glass 8 filled was insufficient, the bonding strength between the core halves 2 and 3 after slicing would be reduced, and there was a risk that the chip would break.

In addition, when the chip height is short as shown in FIG. 11(c) and the slicing position is moved by Q from the position shown in FIG. 11(a), the position of the back groove 6 is also Only Q needs to be changed. For this reason, the machining of the back groove 6 had to be changed depending on the chip height, resulting in a problem that the core was less versatile.

On the other hand, the magnetic head chip 1 shown in FIG. 10 does not have the above-mentioned problems, but the abutting area of the core halves 2.3 is small due to the track width regulating groove 7, and the bonding strength is poor. It had the disadvantage that it had unfavorable magnetic properties.

The present invention has been made in view of the above points, and an object of the present invention is to provide a magnetic head that can stably improve bonding strength and magnetic properties.

[Means to solve the problem]

In the magnetic head of the present invention, a pair of left and right core halves are butted and joined, a winding groove and a back groove are respectively formed on the abutting surface of one of the pair of core halves, and a recording medium of the core is formed. A magnetic head in which a gap film is interposed between abutting surfaces on the sliding surface side is characterized in that the back groove is widened near the end on the outer peripheral side of the core to form a stepped shape.

[Effect]

In the magnetic head configured as described above, the narrow portion of the back groove that strongly contributes to the bonding of the core halves is reliably filled with the bonding material. Further, even if the filling amount of the bonding material changes and the wide portion of the back groove is insufficiently filled, there is no significant difference in bonding strength. Furthermore, since the abutting surface is also formed over the entire surface of the core in the thickness direction, the abutting area can be secured, and the bonding strength and magnetic properties can be improved.

〔Example〕

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

FIG. 1 shows an embodiment of the present invention. In FIG. 1, parts corresponding to those in the conventional case shown in FIG. 9 are denoted by the same reference numerals, and the explanation thereof will be omitted as appropriate.

The feature of this embodiment lies in the shape of the back groove 6, and the structure of other parts is similar to the conventional example shown in FIG.

The width of the portion 6b of the back groove 6 on the outer peripheral side of the core is wider than the width of the portion 6a on the side of the winding groove 5, and is formed in a single step shape.

Here, the manufacturing process of the magnetic head of this embodiment will be explained with reference to FIG. In (a), a winding groove 5 and a stepped back groove 6 are formed by cutting parallel to the longitudinal direction on the abutting surfaces of the core half block 2 of the pair of core half blocks 2 and 3. Form.

Furthermore, between the winding groove 5 and the outer periphery of the abutting surface, a plurality of track width regulating grooves 7 are formed by cutting in a direction perpendicular to the winding groove 5 with a predetermined dimension.

Further, a similar track width regulating groove 7 is formed on the abutting surface of the other core half block 3.

Next, in (b), on the abutting surface between the track width regulating grooves 7 formed in the core half block 2.

A gap film 9 having a predetermined thickness is formed by sputtering or the like. The gap film 9 becomes a magnetic gap of a predetermined width separated by the track width regulating groove 7.

Next, in (c), the pair of core half blocks 2.3 are butted against each other, and the position of the track width regulating groove 7 is set to -M, thereby aligning the tracks. Then, in (d), the rod-shaped glass 8 is inserted into the winding groove 5 and the back groove 6 with the winding groove 5 facing down and welded by heating.

Further, in (e), the end surface of the integrated core half block 2.3 on the recording medium sliding surface side is ground into an R shape to form the recording medium sliding surface 4. Next, in (f), slicing is performed at the position of each track width regulating groove 7 in a direction perpendicular to the groove direction to obtain a magnetic held tip 1 as shown in (g). Note that the core half block 3 of the magnetic helad tip 1 is sliced parallel to the abutting surface, and
) The magnetic head chip 10 may have a shape as shown in FIG.

In the magnetic helad tip 1 manufactured as described above, the glass 8 inserted into the back groove 6 is melted by heating, and is first filled into the narrow part 6a that strongly contributes to bonding, and then filled into the wide part 6a. Portion 6b is filled. Here, as shown in FIG. 3, if the glass 8 is sufficiently filled, the back groove 6 up to the slice position A in the height direction is completely filled with the glass 8. - As shown in Figure 4, even if the amount of glass 8 filled is insufficient and the glass 8 is not filled to the slice position A,
For the length Ql in the height direction of the back groove 6 shown in FIG.
There is no significant difference in the glass filling height Q2 shown in FIG. That is, as long as there is enough glass to fill the narrow portion 6a, there will be no significant difference in the adhesive strength of the chip 1.

Further, as shown in FIG. 5, the slice position of the magnetic head chip 1 in the height direction is shifted from A to B.

When the height is reduced, even if the bonding length Q is shortened, there is no significant difference in bonding strength. Therefore, there is no need to change the position of the back groove in the height direction in advance.

FIGS. 6 to 8 show a comparison of the abutting surfaces of the magnetic head of this embodiment and a conventional magnetic head. The abutting surfaces of the conventional magnetic head core shown in FIGS. 9 and 10, respectively, and the magnetic head core of this embodiment shown in FIG.
They are shown by diagonal lines in FIGS. 6, 7, and 8, respectively. In the figure, (a) is the abutting surface on the core half 2 side, (b) is the abutting surface on the core half 3 side, and (c) is the abutting surface where both core halves 2.3 come into contact. . Although the abutting surfaces shown in FIG. 6 have a smaller area than those shown in FIG. 7, as described above, this has little effect on the joint strength. Furthermore, since the wide portion 6b of the back groove 6 is located away from the winding groove 5, its influence on the magnetic properties is small.

Further, since the abutting surface shown in FIG. 8 is significantly smaller due to the track width regulating groove 7, the magnetic properties are deteriorated.

According to this embodiment, the narrow portion of the back groove 6 that strongly contributes to bonding is reliably filled with glass 8, so that the bonding strength can be stably improved. Furthermore, since the area of the abutting surfaces is large, the magnetic properties are also improved.

In the above embodiments, the case where the core is made of ferrite has been described, but the present invention can also be applied to cases where the core is made of other materials such as amorphous.

Further, the same effect can be obtained even when the back groove 6 is formed on the side of the core half body 3 where the winding groove 5 is not formed.

Furthermore, although glass 8 is mainly used as the bonding agent, by using a magnetic material with high magnetic permeability as the bonding material, it is also possible to reduce the magnetic resistance in the gap portion of the back groove 6 and improve the magnetic properties. .

〔Effect of the invention〕

As described above, according to the magnetic head of the present invention, since the back groove has a stepped shape, the bonding strength and magnetic properties can be stably improved.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the structure of the magnetic bed according to the present invention, Fig. 2 is a perspective view and front view illustrating the manufacturing process, and Figs. 3 and 4 are illustrating the glass filling state. A front view, FIG. 5 is a front view showing the core slice position, and FIG. 6 is a side view showing the gap abutting surface.
7 and 8 are side views showing gap abutting surfaces of an example of a conventional magnetic head, FIGS. 9 and 10 are front views showing an example of a conventional magnetic head, respectively, and FIG.
FIG. 1 is a front view illustrating the state of glass filling. 2.3... Core half, 4... Recording medium sliding surface, 5...
... Winding groove, 6... Back groove, 9 River gap membrane. Patent applicant Victor Japan Co., Ltd.

Claims (1)

[Claims] A pair of left and right core halves are butt-joined, a winding groove and a back groove are respectively formed on the abutting surface of one of the pair of core halves, and a winding groove and a back groove are formed on the side of the core that is in sliding contact with the recording medium. 1. A magnetic head comprising a gap film interposed between abutting surfaces, characterized in that the back groove is widened near an end on the outer peripheral side of the core to form a stepped shape.