JPH0453002B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a multi-element magnetic head, and more particularly to a multi-element magnetic head that can be applied to a data recorder.

Prior Art As a multi-element magnetic head of this type, for example, the present applicant proposed and published an application in Japanese Patent Publication No. 47-1989.
There is one shown in Publication No. 32013. 14th
15 and 15 respectively show the multi-element magnetic head 1 shown in this publication, and FIGS. 16 to 20 show the manufacturing process of this magnetic head 1, respectively. The magnetic head 1 has a structure in which a front core assembly 2 and a back core assembly 3 are combined and incorporated into a holder 4. A plurality of head elements 6 each having a gap 5 are arranged with a channel shield plate 7 interposed therebetween. are gathering. Each gap 5 has a track width w ₁ and is aligned on a straight line at pitch p ₁ .

The front core block 13, which is the basis of the front core assembly 2, is first made by glass bonding so that a gap 10 is formed between a pair of elongated ferrite core blocks 8 and 9, as shown in FIGS. 16 and 17. Then, as shown in FIG. 18, cuts are made from the bottom surface 11 side to form a plurality of grooves 12. This front core block 13 has a structure in which a plurality of upper head element parts 14 are connected at an upper surface part 15 and integrated. The depth a of the groove 12 is such that the thickness b of the upper surface portion 15 is smaller than the depth c of the gap 10, and is relatively large.

On the other hand, the back core assembly 3 is formed by bonding a ferrite core block 18 onto a ceramic block 17, forming a groove, and fitting a coil 19 therein, as shown in FIG. This back core assembly 3 has an integrated structure in which lower head element parts 20 each having a coil 19 wound thereon are connected by a ceramic block 17.

The front block 13 is shown in FIGS. 19 and 20.
As shown in the figure, the upper head element section 14 is opposed to the corresponding lower head element section 20, and the opposing surfaces 27 and 28 are bonded together to be connected to the back core assembly 3.

Next, a channel shield plate 7 consisting of a ferrite plate 21 and ceramic plates 22 and 23 on both sides thereof.
into the matching grooves 12 and 24 and
The front/back core assembly 25 shown in FIG.
By polishing and removing the head to the position of the polishing line 26 shown by the two-dot chain line in FIG. 0, the multi-element magnetic head 1 having a head surface with the channel shield plate 7 exposed as shown in FIGS. .

Problems to be Solved by the Invention In the above magnetic head 1, each head element 6
The track width w ₁ of the groove 12 is determined by the groove 12 .
This groove 12 is for inserting the channel shield plate 7, and has a depth a of about 3 mm. For this reason, the groove cutting cutter tends to run out, run out, etc., and the grooves 12a to 12e in Fig. 21 are
The shape may end up as shown in the figure. When the grooves are formed in this way, the head surface when the upper part of the front core block 13 is polished up to the polishing line 30 will be as shown in FIG. 22, and the head surface will be as shown in FIG. is as shown in FIG. As can be seen by comparing the two figures, for example, the track widths of the head elements 32 are different, as shown by w ₄ and w ₅ , and the center of the other head element 33 is offset, as shown by l. In this way, the track width and track pitch change due to the difference in the amount of wear on the upper surface. More importantly, no matter how the amount of polishing is determined, it becomes difficult to determine the track width and track pitch of each head element so as to satisfy a predetermined dimensional accuracy.

Means and Effects for Solving the Problems The present invention provides, in particular, as shown in FIGS. 3 and 5, of the first core block 47 and the second core block 48 constituting the upper head element assembly 52. A second groove 55, which is wider than the width _w3 of the first groove 51 into which the channel shield plate 46 is inserted and which is extremely shallow, is formed on the abutting surface 47a of one core block 47 with the other core block 48. By polishing both ends of the second groove 55 in the width direction,
The protrusions 56, which are exposed on both sides of the channel shield plate 46 and are formed relative to each other between adjacent second grooves 55 without being affected by distortion during processing of the first grooves 51, have a track width w ₁ It is designed to regulate the amount of water with high precision.

Embodiment Next, an embodiment of the multi-element magnetic head according to the present invention will be described.

1 and 2 show a multi-element magnetic head 40, and FIGS. 3 to 10 respectively show this magnetic head 1.
The manufacturing process is shown below. The magnetic head 40 has a structure in which a front core assembly (upper head element assembly) 41 and a back core assembly (lower head element assembly) 42 are combined and incorporated into a holder 43, and has a gap 44. A plurality of head elements 45
are assembled with a channel shield 46 interposed therebetween. Each gap 44 has a track width w ₁ as before, and is aligned in a straight line at pitch p ₁ .

The front core block 52, which is the basis of the front core assembly 41, is made up of a pair of elongated ferrite core blocks 4, as shown in FIGS. 3 and 4.
7 and 48 are glass bonded so that a gap 49 is formed between them, and then, as shown in FIG. 5, a plurality of grooves 51 (the first
grooves) with a pitch p ₁ equal to the pitch p ₁ described above. This front core block 52 has a structure in which a plurality of upper head element portions 53 are connected at an upper surface portion 54 and integrated. Groove 5
1, the thickness e of the upper surface portion 54 is the gap 4.
The dimensions are smaller than the depth f of No. 9.

On the other hand, the abutting surface 47a of the core block 47
, a plurality of grooves 55 (second grooves) having a width w ₂ , a depth g (0.1 to 0.2 mm), and a length f are formed in the vertical direction in FIG. 3 with a pitch p ₁ equal to the above pitch p ₁ . It has been done. Since the depth of this groove 55 is extremely shallow, grooving is not difficult, and the groove 55 is formed with high precision and with almost no processing distortion remaining. By this groove machining, a plurality of protrusions 56 having a width w ₁ that is relatively equal to the above width w ₁ are formed with high precision at pitch p ₁ . As will be described later, the ridges 56, ie, the inner edges of adjacent grooves 55, regulate the track width of the head element. Furthermore, the width w ₃ of the groove 51 and the width w ₂ of the groove 55 have a relationship of w ₃ <w ₂ .

The back core assembly 42 is made by bonding a ferrite core block 58 onto a ceramic block 57 as shown in FIG. 6, forming a groove 59 in the longitudinal direction of the core block 58 as shown in FIG. As shown in FIG. 3, a groove 60 corresponding to the groove 51 is formed in the width direction of the core block 58. The groove 60, like the groove 51 described above, has a width of w ₃
It is formed by cutting down to the ceramic block 57 with pitch _p1 . This back core assembly 42 has a structure in which a plurality of lower head element portions 61 are connected by a ceramic block 57 and integrated. A coil 62 is fitted into each lower head element portion 61, as shown in FIG.

The front core block 52 is shown in FIGS.
As shown in FIG.
4 is in direct contact with the back core assembly 42 and the grooves 51 and 60 are aligned,
It is fixed by a jig (not shown).

Next, a channel shield plate 46 having a laminated structure in which ceramic plates 66 and 67 are bonded to both sides of a ferrite plate 65 is inserted laterally into the matching grooves 51 and 60. Here, the height dimension h of the ceramic plates 66, 67 and the depth dimension d of the groove 51 have a relationship of h>d, and in the inserted state, as shown in FIG. 6
Of the parts 6 and 67, the hatched portion i×j enters into the groove 60, and the adjacent lower head element portion 6
contact the opposite surfaces of 1. That is, the ceramic plates 66 and 67 are in a state where they straddle the grooves 51 and 60. Further, the channel shield plate 46 has the grooves 51 and 69 with adhesive applied to both sides 68 and 69.
60.

As a result, the opposing surfaces of the adjacent upper head element portions 53 are bonded to the channel shield plate 46, and the portion near the upper portion of the opposing surfaces of the adjacent lower head element portions 61 is attached to the lower end of the channel shield plate 46. Glue to nearby parts. As a result, the front core block 52 and the back core assembly 42
are coupled via a channel shield plate 46,
A front/back core assembly 70 is obtained. In this front/back core assembly 70, the upper head element portion 53 and the lower head element portion 61 are in a state in which opposing surfaces 63 and 64 are in direct contact with each other without an adhesive layer interposed therebetween.

Next, this assembly 70 is fitted into the holder 43 (see FIG. 1) and fixed, and in this state, the position of the polishing line 71 shown by the two-dot chain line in FIG. Polish until removed. As a result, as shown in FIGS. 1 and 2, the head element 45 has a head surface with the channel shield plate 46 exposed, and has a gap 44 with a track width w ₁ and a gap depth k with a pitch p _{1 .} A multi-element magnetic head 40 is obtained which is integrated with the elements aligned and shielded from each other by the channel shield plate 46.

In this multi-element magnetic head 40, the upper head element part 53 and the lower head element part 61 constituting each head element 45 are in a state in which opposing surfaces 63 and 64 are in direct contact with each other without using an adhesive between them. Since no back gap is formed, magnetic resistance is reduced, core efficiency is improved, and recording and reproducing characteristics are also improved.

Next, the function of the groove 55 will be explained with reference to FIGS. 11 to 13.

FIG. 11 is a front view of the front core block 52, in which 55 is a groove and 56 is a protrusion. It is assumed that the grooves 51 are formed in the same manner as shown by reference numerals 12a to 12e in FIG. When the upper part of the front core block 52 is polished to the polishing line 72, the head surface becomes as shown in FIG. 12, and when it is polished to the polishing line 73, the head surface becomes as shown in FIG. Figures 12 and 13
As can be seen from the figure, the track width and track pitch of each head element 45 are determined by the inner end of the adjacent groove 55, that is, the protrusion 5, regardless of the groove 51.
6, and have predetermined dimensions w ₁ and p ₁ , respectively. Further, even if the amount of polishing varies, the track pitch is maintained at a predetermined track pitch _p1 and does not change, and the track width is also maintained at a predetermined track width _w1 and does not change. Therefore, with the multi-element magnetic head 40 having the above structure, it is possible to improve the precision of track width, track pitch, and track alignment.

In addition, with the formation of the groove 55, the groove 51
and 60 can be made smaller than before, and thereby the width w ₄ (see FIGS. 5 and 8) of the upper head element section ₅₃ and the lower head element section 61 can be made larger than before. As a result, each head element portion 5
The strength of 3,61 increases and it becomes less likely to chip. Furthermore, as the width of each head element portion 53, 61 increases, the magnetic resistance of the core decreases.

Effects of the Invention As described above, according to the multi-element magnetic head of the present invention, the track width of each head element is not the deep first groove into which the channel shield plate is inserted;
The track width is regulated by a protrusion formed relative to a second groove formed in a portion of the abutting surface of the first core block where the first groove is formed. Since it is determined by the groove machining of the second groove, which can be formed with high precision, without being affected by the first groove machining, it is possible to achieve high precision in track width and track pitch, and also to improve the accuracy of the track width and track pitch. Since the depth of the grooves may be shallow, they can be formed with narrow pitches, which allows each head element to have a narrow track.Furthermore, by narrowing the groove width of the first groove, the thickness of the upper head element portion can be reduced. It is also possible to make it relatively thick, and by doing so, it has the advantage of increasing the strength and lowering the magnetic resistance.

[Brief explanation of the drawing]

1 and 2 are a partially cutaway perspective view and a plan view, respectively, of an embodiment of a multi-element magnetic head according to the present invention, and FIGS. 3 to 5 each illustrate a method of manufacturing a front core block. Figures 6 to 8
The figures are diagrams each explaining the method of manufacturing the back core assembly, Figures 9 and 10 are diagrams explaining the method of manufacturing the front back core assembly, respectively, and Figure 11 is a diagram showing the front core block cut from the bottom. FIGS. 12 and 13 are front views of the front core block showing exaggerated groove shapes; FIGS. 14 and 13 are views showing the head surface obtained by polishing the upper part of the front core block of FIG. FIG. 15 is a partially cutaway perspective view and a plan view of an example of a conventional multi-element magnetic head, and FIGS. 16 to 18 are diagrams illustrating a method of manufacturing a front core block.
9 and 20 are diagrams explaining the method of manufacturing the front/back core assembly, respectively. FIG. 21 is a diagram exaggerating the deformation of the groove cut into the front core block from the bottom surface. FIG. 23 is a view showing the head surface obtained by polishing the upper part of the front core block of FIG. 21, respectively. 40...Multi-element magnetic head, 41...Front core assembly (upper head element assembly), 42...
Back core assembly (lower head element assembly), 4
4...Gap, 45...Head element, 46...
Channel shield plate, 47...Core block, 4
7a...Abutment surface, 51...Groove (first groove),
52... Front core block, 53... Upper head element portion, 55... Groove (second groove), 56...
Projection portion, 61... Lower head element portion, 65... Ferrite plate, 66, 67... Ceramic plate, 70
...Front/back core assembly, 71...Polishing line.

Claims (1)

[Claims] 1. An upper head element assembly in which a plurality of upper head element portions each forming a gap are aligned and integrated, and a plurality of lower head element portions are aligned and integrated. is coupled to a lower head element assembly;
A corresponding upper head element portion and a lower head element portion form one head element, and the upper head element assembly includes a first core block and a second core block forming a gap therebetween. A multi-element assembly comprising channel shield plates inserted into a plurality of first grooves formed by cutting from the bottom side of the assembly, which are butted against each other, and the upper surface of the assembly is polished to expose the channel shield plates. In the magnetic head, a portion of the abutting surfaces of the first core block and the second core block, where the first groove is formed, has a width wider than the width of the first groove and a pole. A plurality of shallow second grooves are formed extending in the depth direction of the gap, and the abutting surface is formed with a protrusion extending in the depth direction of the gap between the adjacent second grooves. The striations are formed relative to each other, the upper ends of the second groove in the width direction are exposed on both sides of the exposed channel shield plate, and the protrusion restricts the track width of the head element. A multi-element magnetic head characterized by: