JPS61265721A - Magnetic head device - Google Patents

Abstract

PURPOSE:To make the thickness of a holder uniform at a side where it contacts with a base plate of a head core chip without changing with the lapse of time in the height of the head by providing a recessed part or a step to the 1st plane of the base plate on which the magnetic head is arranged and arranging the magnetic head to the recessed part or the step. CONSTITUTION:A hard material is used for a base plate 15 more than that of holders 16, 17 of a head chip 14. Further, the recessed part 18 of nearly the same size as that of the head chip 14 is formed to a stuck part of the head chip 14 of the base plate 15 by machine processing. Then a holder 16 having a thickness tHO with a glass member 27 is stuck to the recessed part 18 by using a glass member 30 having a lower softening point than the glass member 27. Then the incorporated base plate 15 and holder 16 is processed by both-face lapping or cut processing. Since the type of material of the base plate 15 is harder than that of the holder 16, the processed face of the holder 16 and a reference face 25 of the base plate 15 are finished on the same plane and the thickness of the holder 16 is an object value tH. Finally, the core 21 and the holder 17 made of a magnetic metallic material are connected by lamination into a specified size and position by an organic adhesives or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetic head device, and more particularly to a magnetic head device having a core made of a metallic magnetic material.

[Technical background of the invention]

In recent years, video tape recorders (VTRs) have been on the path to miniaturization. In addition, in keeping with this trend, magnetic recording media are also being made to have higher coercive force in order to improve their recording density. For example, coated or vapor-deposited metal tapes having a coercive force of 1,400 to 15,000 eali have appeared. By the way, in the conventionally commonly used ferrite head, the magnetic flux density is 6QQQG even if it is made of high magnetic flux density material.
This makes it impossible to perform sufficient recording on a magnetic recording medium with high coercive force. The maximum magnetic flux density is soo.

Metallic magnetic materials with G: around 11138 are attracting attention. For example, when sendust material is used as the core, as shown in Figure 2JcQ, the core (1) has a gap length g finished to a thickness that matches the track width Tw, and has a high magnetic permeability and a large specific resistance (1) from both sides. 01Ω・(1)
above), the head core chip (4) is formed by holding the head core chip (4) between the holders (2), (3) made of, for example, M low Zn ferrite material. At this time, the vicinity of the gap of the core (1) is protected by a glass material (Gl, +6) filled in the tip of the winding hole (5) of the holder (21, +3).

Then, fix the head chip (4) to a separately prepared metal or ceramic base plate as shown in Fig. Furthermore, the terminal plate (8) is pasted at the specified position with organic adhesive, etc. Then, the winding coil (9) is wound, and the end of this coil (9) is inserted into the lead wire through hole Q1.
and soldered to the copper foil part of the terminal board (8).

αB is the fixing screw hole in the base plate (7).The magnetic head thus created has efficient recording characteristics, and the Eddy current loss during reproduction, which is characteristic of metal magnetic materials, has been improved. .

[Problems with background technology]

FIG. 11 is a front view of essential parts of the magnetic head device shown in FIG. 1O. It is understood that the head chip (4) is attached with a low viscosity organic adhesive αa or the like. By the way, V
In TR, two or more magnetic heads are installed in the cylinder, but in this case, the reference surface (
For 13t/C, heads assembled in the same cylinder are combined with a head height H. however,
This dimension H also includes the thickness of the organic adhesive layer present between the base plate (7) and the helad chip (4). The thickness la of this layer is generally 1 to 15 μm thick, and this layer is easily influenced by humidity, and has a tendency for la to increase by 5 μm to (9) μm from the initial value due to changes over time. In severe cases, the head chip (force) may peel off from the base plate (7) due to long-term high humidity conditions.Furthermore, if the dimensions 1a of the head devices assembled in the same cylinder change, This will lead to large image disturbances.Furthermore, the accuracy of the thickness tH of the holder (2) or (3) will depend on the machining conditions, and for example, if the target thickness is 100 μm, it will be approximately 3 μm. Therefore, as a matter of course, it is difficult to keep the dimension H constant, resulting in a disadvantage of +5.

[Purpose of the invention]

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 device in which the head height dimension H does not change over time and the thickness of the holder on the side of the head core chip in contact with the base plate is uniform. With the goal.

[Summary of the invention]

The present invention provides a concave portion or a stepped portion on the first surface of the base plate on which the magnetic head is disposed, and when the magnetic head is disposed here, the joint surface between the first holder and the core of the magnetic head is It is configured to be substantially flush with the first surface of the base plate.

[Embodiments of the invention]

An embodiment of a magnetic head device according to the present invention will be described below. FIG. 1 is a perspective view showing the above embodiment. The base plate to which the magnetic head chip α is attached (19 is the holder ue of the magnetic head chip I, (I7) is made of ceramic harder than ferrite (Vickers hardness 650), such as M2O3 or AA'T i C (Vickers hardness of 1000 or more).

The head chip 0 is attached to the recessed part A armor-1. Next, the detailed structure of the magnetic head tip and the mounting state of the tip will be explained with reference to FIG. 2, which is a front view of the main parts of the magnetic head device shown in FIG. For example, the core Qυ made of Sendust) is held in the aforementioned holder (IG, αη), and the winding hole @ of this chip I is wound with a coil (c). Both terminals of the terminal board (to) are connected to the pattern of the terminal board (■
20a) and (20b), respectively.

To describe the installation of the head chip (14) to the base plate (1), the attachment surface (reference surface) 2!1 to the cylinder of the base plate a9, the holder αe of the head chip 04) and the core (20 The bonding surfaces with (c) are almost the same.
is an inorganic adhesive (for example, glass) layer, and (to) is a glass material filled in the holder ae, αη.

According to the above configuration, since the magnetic held tip O and the base plate αS are bonded by an inorganic adhesive, there is no change in the thickness of the adhesive layer due to aging. When a plurality of devices of this example are installed, there is no difference in the H dimension shown in FIG. 2 between them, and good recording and reproduction can be performed.

Note that there is no problem since the magnetic radchip is performed using an inorganic adhesive.

Next, an embodiment of a method for manufacturing the above magnetic head device will be described. First, a base plate a9 as shown in FIG. 3 is manufactured.

The material of this base plate Q9 is as described in 1. As mentioned above, a material harder than the material of the holders u, e, and αη of the magnetic helad tip α ship is used. Further, on the base plate a9, a concave portion having approximately the same size as the head chip a4 is formed by machining in the area where the helad chip 0 is attached. In this case, the depth d of the recess α$ is set so as to satisfy the relationship dMkitH with respect to the target height j′H of the head tip lino holder αe. FIG. 4 is a front view of essential parts of the base plate α9. Next, as shown in FIG. 5, a holder αe having a glass material (2) and a thickness 'f (O) is joined to the recess α mallet with a glass material (30) having a lower softening point than the glass material ■. is 'HO> for dM
The base plate a9 shown in FIG. 5 and the holder αe are integrated into a 0-order set so as to satisfy the relationship du, and are processed into the shape shown in FIG. 6 by double-sided lapping and cutting. . In other words, the base plate (Is is made of material of the holder α
Because it is harder than the material of Q, it does not wear out during lapping, and only the part protruding from the base plate α9 of the holder (Ie) is lapped. The machining surfaces of c) and holder αe are always finished on the same plane.Then, the thickness of holder ae becomes the target tH.Finally, place core Qυ made of metal magnetic material such as sendust and holder a in the specified dimensional positions. The glass of the organic adhesive or the glass filling part (3) is also laminated and bonded to the glass having a low softening point.As a result, the shape shown in FIG. 2 above is finally obtained.

Another embodiment of the invention is shown in FIGS. 7 and 8.

In this case, only the shape of the base plate has been changed, and the rest is no different from the previous embodiment. That is, the base plate Gυ shown in FIG. 7 has a concave portion (concave S) formed up to the rear end of the reference surface G3 of the base plate Gυ, and can be easily cut with a whetstone or cutting tool. In addition, the base plate (b) shown in Fig. 8 has the protruding part of the base plate 0 in the reference plane (to).
The finally completed magnetic herad device is approximately the same as the one shown in FIG. 1, in which the stepped portion (to) is formed by reducing the dimension by dM.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent the adhesive layer from deteriorating over time, which has been a problem in the prior art, and it is possible to improve recording and reproduction in a VTR.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the magnetic head device according to the present invention, FIG. 2 is a front view of main parts of the device shown in FIG. 1, and FIGS. 3 to 6 are manufacturing of the device shown in FIG. 1. 7 and 8 are perspective views showing other embodiments of the base plate of the present invention. FIG. 9 is a perspective view showing a conventional magnetic helad tip.
0 is a perspective view showing a conventional magnetic head device, and FIG. '11 is a front view of the main part of the device shown in FIG. 15...Base plate, 16.17...Holder,
18... recess, 21... core. Agent Patent Attorney Noriyuki Chika (and 1 other person) Figure 1ciQ Figure 12 Figure 4 Figure 5 Figure 8 Figure 9 Figure 10 Figure 11

Claims (3)

[Claims] (1) A magnetic head consisting of a first and second holder and a core made of a metal magnetic material held by these holders, and a recess or stepped portion in which the magnetic head is disposed on the first surface. a base plate having a base plate, and in a state where the magnetic head is attached to the base plate, the joint surface between the first holder and the core of the magnetic head is substantially flush with the first surface of the base plate. A magnetic head device characterized by: (2) The magnetic head device according to claim 1, wherein the material of the base plate is harder than the material of the first and second holders. (3) The magnetic head device according to claim 2, wherein the base plate is made of a ceramic material such as Al_2O_3 or AlTiC.