JPH04328316A - Magnetic head - Google Patents

Abstract

PURPOSE:To reduce the size and weight of the magnetic head by improving the head space material of the head and to improve the chip sticking strength of a head chip to a head base and conductive performance. CONSTITUTION:The head base 22 for fixing the head chip 21 consisting of a magnetic material is formed by using a conductive resin material. Further, the surface roughness in the head chip sticking part 22B constituted on the head base 22 is formed rougher in surface roughness than the other parts, by which the chip sticking strength is increased.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used in a rotary head of a video tape recorder or the like.

0003

[Prior Art] Conventionally, a video tape recorder (VTR)
The configuration of the magnetic head 1 used in FIG. 7(a) is as follows.
, (b), a head chip 2 made of a magnetic material was attached to a brass fixing base 3 and wound. A terminal board 4 is attached to one side of the head base 3.
One end of a winding material 5 is soldered to this terminal plate 4. The magnetic head 1 assembled in this way is shown in FIG.
c) As shown in , it is fixed with screws 7 to one surface of an upper drum 6 that constitutes one of the rotating drums. The state is shown in FIG. 7(d). (c) and (d) show a two-head rotating drum. The upper drum 6 assembled as shown in FIG. 7(d) is fitted and attached to the lower drum 8 on the fixed side shown in FIG. 7(e) and the rotating portion constructed at the center thereof. Below this rotating part,
A rotary transformer 9 consisting of a stationary core 9a and a rotating core 9b is provided. Each core 9a, 9b is wound with a wire. Through this rotary transformer 9, the magnetic head 1 side and a recording/reproducing circuit side (not shown) are electromagnetically coupled.

FIG. 8 shows an upper drum 6 and a lower drum 8.
This shows the state in which they are combined. In FIG. 8, 10 is a fixed part;
11 indicates a rotating part, and the upper drum 6 on the rotating part 11 side
is fixed to the tip of the rotating shaft 12, and is rotated by a rotation drive means (not shown). A printed circuit board 13 is fixed to the upper surface of the upper drum 6, and a rotating coil of the rotary transformer 9 is connected to this printed circuit board 13 by a wire 14.

By the way, in the conventional magnetic head 1 described above, the brass base 3 is finished one by one by molding, and when assembling the magnetic head 1, the head chip 2 is assembled with the head base 3 as a single item. used. Therefore, from the process of attaching the pre-finished head chip 2 to this brass base 3, winding, molding, etc.
This brass base 3 also serves as a jig in a series of manufacturing processes such as finishing the curvature of the sliding surface of the chip. and,
In order to carry the magnetic head 1 that is finished as a single item in this way, a special storage case is required to prevent each head from being damaged. On the other hand, for example, a movie-type video tape recorder (VTR) with an integrated camera, etc.
As devices become smaller and lighter, it is necessary to reduce the weight in grams. Furthermore, the head base used in miniaturized video tape recorders must also be small and light.
Its structure is also required to be precise and have excellent workability.

[0006] For example, the size of the base plate used in 8 mm movies has to be reduced because the cylinder diameter of the rotating drum is as small as 30 mm or less.

[0007] Brass also has very high thermal conductivity, so when fixing the end of the wire to the terminal board with solder during wiring,
Due to the speed of heat conduction from, for example, a glass epoxy board pasted onto a brass base, the adjacent solder melts, making it difficult to apply a soldering iron for a sufficient amount of time. was.

[0008] Furthermore, when a so-called flying erase head is attached to a rotating drum, which is used to completely erase the previously recorded portion and eliminate so-called rainbow noise when recording with a video tape recorder, the rotating drum In order to maintain balance during rotation, it was necessary to place a dummy base of the same weight on the diagonal.

[0009] Under these circumstances, materials for the base plate have been considered, ranging from metal brass to ceramic materials and plastic materials. However, since the former is a metal material, it has poor workability and is difficult to form into complex shapes. The latter has poor weather resistance and mechanical strength, has a large coefficient of thermal expansion, and has poor thermal stability, so although it is lightweight, it is not suitable for brass. It could not be replaced. Further, in order to prevent charging within the head chip, the chip and base plate are normally required to be grounded. In this respect as well, in terms of materials, the ceramic materials and plastic materials mentioned above cannot be used.

Furthermore, with conventional base materials, when a head chip is attached to a head base, the permeability of an adhesive is poor, resulting in a problem in that the adhesion strength of the chip is weak.

[0011]

[Problems to be Solved by the Invention] As mentioned above, conventional magnetic heads have manufacturing problems such as workability, chip adhesion strength, thermal conductivity, and portability due to the base plate material. However, there was a problem that it was not suitable for miniaturization and weight reduction.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a magnetic head that can be made smaller and lighter by improving the material of the base plate, and can also eliminate manufacturing problems.

[Configuration of the invention]

[0014]

[Means for Solving the Problems] A magnetic head according to the present invention as set forth in claim 1 uses a conductive resin material for a head base for fixing a head chip, and a surface roughness of a chip sticking portion of the head base is provided. It is characterized by having a rougher surface than other parts.

[0015]

[Function] In the present invention, by using a conductive resin material for the head base, lightness, precision (dimensional stability),
It becomes possible to have conductivity. Additionally, since it is a synthetic resin, injection molding is possible, making it possible to manufacture base plates with complex structures. Using conductive molding material,
In addition, by increasing the surface roughness of only the chip sticking portion, it is possible to increase the chip sticking strength and the conductivity. Therefore, the mechanical strength of the magnetic head consisting of the head base and the head chip can be increased, as well as the electrical performance.

[0016]

[Example] An example will be described with reference to the drawings. FIG. 1 is a perspective view illustrating a chip attaching section in a magnetic head according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a side sectional view showing a method for attaching a chip. Figure 4
, 5 and 6 are process diagrams illustrating the manufacturing process of a magnetic head and a head device using the same according to the present invention.

First, the manufacturing process of the magnetic head and head device will be explained with reference to FIGS. 4 to 6. In FIG. 4(a), 21 is a head chip, and this head chip 21 sandwiches the gap between the pair of core halves (
It is formed by bonding magnetic materials). Reference numeral 22 denotes a head base, and this head base 22 is an injection molded product made of a molding material and formed into a substantially circular shape to match the shape of the rotating drum. This head base 22 is provided with two base parts 22A so as to protrude on the circumference of the circular part.
It is for the head. Furthermore, a chip pasting part 22B is provided so as to protrude from the tip of each base part 22A. A hole 23 is formed in the center of the head base 22 to fit the rotating shaft of the rotating drum, and a terminal plate 24 is attached to one surface of each of the two base parts 22A. The head base 22 is formed by injection molding a molding material made of a conductive resin material. This molding material is
For example, as described in JP-A No. 62-207313, (A) 14 to 40% by weight of a thermosetting resin (e.g., epoxy resin) containing a curing (accelerator) agent and a catalyst;
B) 10 to 85% by weight of spherical carbon and/or graphite with a diameter of 5 to 150 μm; (C) fine powder of silica, Ca CO3, glass beads, etc., with a particle size of 50 μm or less or a fiber length of 1 mm or less; montmolinite; A filler containing 5 to 56% by weight of an inorganic filler selected from clays such as hectorite and hydrated halloysite, and layered inorganic compounds such as thallium sulfide, zirconium hydrogen phosphate, and ferric oxychloride is used. In addition, as a molding material, JP-A-1-951
A thermoplastic resin as described in Japanese Patent No. 58 may also be used.

Each chip attachment portion 2 of this head base 22
The head chip 21 is glued on one side of 2B, and then further shown in FIG.
b) As shown in FIG. 2, the head chip 21 is wound with a wire, and one end of the wire 25 is soldered to the terminal plate 24.

Next, as shown in FIG. 4(c),
b) The magnetic head is attached to the tape wrapping jig (processing cylinder) 26, and the head chip 21 is tape wrapped (sliding surface finishing). FIG. 4(d) shows the completed magnetic head 20.

The magnetic head 20 shown in FIG. 4(d) is similar to the magnetic head 20 shown in FIG. 5(a).
) As shown in FIG.
It is fixed with screws. FIG. 6 shows a cross-sectional view of the magnetic head 20 and the upper drum 27 before they are assembled. Then, the upper drum 27 shown in FIG. 5(a) to which the magnetic head 20 is screwed is replaced with the lower drum 29 shown in FIG. 5(b).
Fit and attach to the rotating part inside.

In the magnetic head manufactured as described above,
By using a conductive material for the head base, it is possible to have light weight, precision (dimensional stability), and conductivity. Furthermore, since it is a synthetic resin, injection molding is possible, making it possible to manufacture base plates with complex structures. Head bases with complex shapes can be manufactured with high precision, so when multiple head bases are integrally formed on the same disc shape, the circumferential position and height position of each head can be accurately determined in advance during molding. can be determined. In addition, the base material used has low thermal conductivity, so when soldering the lead wire material that connects the rotary transformer to the terminal board on the base, the adjacent soldered parts will not melt. Good workability. Furthermore, since we use a molding material with conductivity,
Since electrical conduction between the head chip and the head base, which needs to be prevented from charging, is possible, and the head base is lightweight, a dummy head for balance is not required when placed on the drum. Also,
Even when dummy formation is required, it can be done at the same time during molding.

Next, the chip attaching portion of the magnetic head will be explained with reference to FIGS. 1 to 3. In this embodiment, when attaching the head chip 21 onto the conductive head base 22 formed by injection molding, the attaching portion 22 is
By partially increasing the surface roughness of B, it is possible to increase the chip adhesion strength, which is a drawback peculiar to injection molded plastics, and also to increase the conductivity. The chip attachment surface can be partially roughened easily by chemical etching or the like when manufacturing a mold in advance. To attach the head chip 21 to the head base 22, attach the head chip 2 to the roughened attachment part 22B with adhesive 60.
Glue 1. Thereafter, the head chip 21 is wound with a wire as described above, and one end of the wire is connected to a terminal plate formed on one surface (the opposite surface from the one shown) of the base portion 22A.

As described above, by increasing the surface roughness of the bonding portion 22B to which the head chip 21 is bonded, the strength of bonding the head chip increases, making it possible to support mass production. Furthermore, the conductivity of the head chip and head base is increased, and a magnetic head with stable performance can be manufactured.

[0024]

[Effects of the Invention] As described above, according to the present invention, the base
By forming the base plate material using a conductive resin material, it is possible to reduce the size and weight, and the surface roughness of the chip attachment part of the head base is made rough, which increases the strength of chip attachment and improves the base plate. The conductivity between the chips and the chips increases, which can improve mechanical strength and electrical performance.

[Brief explanation of drawings]

FIG. 1 is a perspective view illustrating a chip attaching section in a magnetic head according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG. 1.

FIG. 3 is a side sectional view showing a method of attaching a chip.

FIG. 4 is a process diagram illustrating the manufacturing process of the magnetic head according to the present invention.

FIG. 5 is an exploded perspective view of a head device using the magnetic head of FIG. 4;

FIG. 6 is an exploded cross-sectional view of a head device using the magnetic head of FIG. 4;

FIG. 7 is an explanatory diagram illustrating a conventional magnetic head and a head device using the same.

FIG. 8 is a sectional view showing a conventional head device.

[Explanation of symbols]

20 Magnetic head 21 Head chip 22 Head base 22A Base part 22B Chip attachment part

Claims (1)

[Claims] 1. A head chip made of a magnetic material and a sticking part made of a conductive resin material for sticking the head chip to the tip of a base part, the surface roughness of the sticking part being and a head base formed more roughly than other parts.