JPS62159308A - Electromagnetic transducer - Google Patents

Abstract

PURPOSE:To sharply improve the productivity of an electromagnetic transducer, by using a coil formed by installing coil conductors to a flexible base body integrally and connecting the coil conductors with another conductors installed to another base body integrally under a wireless condition. CONSTITUTION:A coil forming member 14 formed by sticking coil conductors to a flexible film base is fitted through a hole 2 for winding and a winding coil is formed wit this film. In the source of the manufacturing, the material for making the coil conductors is made to adhere to the entire surface of a base 15 and processed to a coil conductor pattern 13 after adhering, and then, terminals 16 for connection are formed at each terminal section integrally. Then the surface is covered with an insulating layer 17. When the coil forming member 14 thus manufactured is passed through the hole 2 for wiring of a head at least one time and terminals are connected with each other by means of a printed circuit board 3 as shown in the figure under a condition where each terminal section is faced to another, and then, input and output are pulled out, the coil forming member 14 can be caused to operate as a coil.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Application of Sanchido The present invention relates to an electromagnetic transducer, and more particularly, to an electromagnetic transducer particularly suitable for a small electromagnetic transducer such as a magnetic head.

Conventionally, the winding of a magnetic head, for example, a bulk head, has a 13th winding.
As shown in the figure, the coil 3 is wound around the coil winding hole 2 of the core 1 by hand or by an automatic winding machine. However, this is a small size C1 = 700 μ
(nSm=700 μm) This is very troublesome because it is done through the winding hole 2.

In particular, in the case of a multi-head (a plurality of single heads arranged) shown in FIG. 14, for example, in the case of an electronic still camera, the track interval is 0.04 mm, corresponding to the minute pitch between each head.
It is as narrow as 0.1 to 0.2 mm even for PCM heads. In this case, the size of the coil winding hole 2 of the head is j! '' = 500 μm 1 m' = 500 μm, which is even smaller, and the gap d between each head is 40 μm, so winding is no longer possible with an automatic winding machine and can only be done by hand.

That is, the coil is made of formal conducting wire with a diameter of 0.035 to 0.020, and it is very difficult to wind it through the above-mentioned minute gap. For example, the winding portion is enlarged using an illuminating magnifying glass and wound using a bin set, etc., but it takes a lot of effort and is even more difficult to wind the wire around adjacent head cores one after another. In the case of heads for electronic still cameras, the track spacing is 0.04 fins,
It is impossible to wind it using a looper or the like.

Purpose of the Invention The present invention has been made in view of the above circumstances, and includes:
The object of the present invention is to provide an electromagnetic transducer capable of attaching coils with high productivity and yield.

21. Structure of the Invention The present invention provides a coil forming member in which a coil conductor is integrally provided on a flexible base, which is inserted into a coil winding hole in a core portion, and is connected to a base other than the flexible base. The present invention relates to an electromagnetic transducer configured such that an end portion of the coil conductor is wirelessly connected to an integrally provided conductor to form a coil.

E. Example Hereinafter, an example in which the present invention is applied to a magnetic head will be described.

FIG. 1 shows an example of a magnetic head called a balanced type.

The core 1 of this head is provided with a winding hole 2 similar to that described above, and according to this embodiment, a coil conductor is attached to the flexible film base through this winding hole 2. A coil forming member 14 is attached and the film forms a wound coil.

That is, this coil forming member 14 is completely different from conventional coils, and has a thickness of, for example, 5 μm as shown in FIGS. 2 and 3.
m film base (e.g. polyethylene terephthalate base) 15, Cu % A u s F e SA
A coil conductor NlA13 made of G, A1, or an alloy thereof is formed by sputtering, vacuum evaporation, or the like. In manufacturing, a coil conductor material (for example, Cu) is adhered to the entire surface of the base 15, and then a predetermined coil 46! is formed using known photolithography techniques. Processed into a pattern 13, with connection terminals 16 at each end.
be formed into one piece. Then, the surface is covered with an insulating layer 17, for example, a polyimide resin. Alternatively, a one-color sewing material such as SiO□ or Si 2 N 4 is applied by sputtering. After this, it is etched and melted into the shape shown in FIG. 2, and the coil forming members can be cut out individually.

Such a coil forming member 14 is passed through the winding hole 2 of the head at least once in FIG. If the outputs are respectively taken out, it can be operated as a coil (note that the coil forming member 14 may be attached to the left side of the winding hole 2 in the same manner as above, but this is not shown).

Therefore, even if the winding hole 2 is small and the spacing or gap is narrow as shown in FIG. A similar coil can be created by passing it through hole 2, so
Productivity is greatly improved, workability is good, and yield is also significantly improved.

The printed circuit board 3 includes wiring 5 made of Cu or the like formed in a predetermined pattern by photolithography on an insulating translucent substrate (for example, a thin plate made of polyimide film) 4, and solder plating is applied to the wiring 5. , the wiring 5 is aligned with the terminal 16 and heated, and the two are connected by solder. Since the insulating substrate 4 is semi-transparent, alignment is possible; however,
By attaching a marker to the support 6 that supports the coil forming member, accurate alignment can be achieved.

Connections between terminals, terminals and people, and connections between output terminals are as follows:
This is generally done by wire bonding. Generally, the number of turns of the coil is about 15 turns, and wire bonding needs to be performed one more time than the above number of turns, which takes a considerable amount of time. Moreover, when wire bonding is performed multiple times, if there is a defect in even one connection, the magnetic held ε will not work, resulting in a high failure rate.

Under these circumstances, in the present invention, the terminals are connected by the method described above without wire bonding. According to this method, the connection work is simple and reliable.

When inserting the coil forming member 14 into the winding hole 2, the enlarged end portion can be elastically deformed so as to be reduced in size, and then the coil forming member 14 can be passed through the coil forming member 14. However, after Shintoism, the coil forming member 14 is restored to its original shape as shown in the figure.

Thereafter, the coil forming member 14 is pressed against the surface of the core 1 to deform it as shown in FIG.
5 is made sufficiently thin, the core forming member 14
is deformed along the surface of the core 1 and is in close contact with the core 1, so that the winding shape is good.

In addition, in FIG. 1, when attaching the coil forming member 14, it is preferable to attach the pair of cores 1 after glass fusing. If the coil forming member 14 is attached before the glass is fused, it will interfere with the fusion work and tend to cause misalignment between the cores (the misalignment between the cores must be several μm or less).

Moreover, the glass may protrude into the winding hole 2, enter between the film base 15 and the core 1, and solidify. If the coil forming member 14 is installed out of position, it is no longer possible to correct it, so it is desirable to install the coil forming member 14 after the glass is fused.

In FIG. 4, coil conducting wires 13 are laminated with an insulating layer 17 (for example, polyimide resin) interposed therebetween. The upper coil conductor wire is also coated with an insulating layer 17. In this way, since the number density of the conducting wires 13 can be increased, it is possible to narrow the width W1 of the coil forming member 14 and increase the magnetic field strength to improve the magnetic properties. It is also possible to improve workability, such as making it easier to pass the wire through the hole 2.

In this case, a through hole is provided in the insulating layer 17 on the end of the lower layer coil conducting wire 13, and when forming the connecting terminal on the surface, the connecting terminal and the lower layer coil conducting wire are connected through the through hole. .

As the film base, polyimide resin, polycarbonate resin, polytetrafluoroethylene resin, etc. are used. Film base thickness: 4 to 100 μm
is desirable.

Using these film bases, a coil forming member was manufactured through the following steps, and was attached to a core to form a magnetic head.

1) Place the film base in a vacuum chamber.1. OX 10-
'Pull the vacuum to Torr.

2) Set the gas pressure to 6.0×10-” Torr using Ar gas.

3) Apply a voltage of 2.0 to 3.0 W/c11 between the Cu target or Au target and the film base to generate glow discharge and perform sputtering to reduce the film thickness to 2.0 W/c11.
Let it be X10-'m.

4) Apply a resist (AZ-1350; manufactured by Hoechst) to the film base to which the Cu film or Au film is attached.

5) The above material is exposed, developed, and etched (acid resistant) to obtain a desired pattern.

6) After obtaining the desired pattern, remove the resist (organic solvent resistant).

7) Etching and fusing into the desired shape, 8) Attach it to the core and use it as a magnetic head.

FIG. 5(a) shows an intermediate product of the coil forming member patterned in the step 5) above. If part A in the figure is shown in an enlarged view, it becomes as shown in figure (b). The width of the densely formed portion 13a of the Cu or Au conductor 13 is 10μ.
m, and the width of the roughly formed portion 13b on both sides thereof is 50 μm.

A large number of patterns shown in FIG. 2(b) are formed and the pattern shown in FIG.
It consists of the intermediate products shown in .

This process is performed using a photolithography method. That is, as shown in FIG. 6, a photoresist 13-3 is formed in a predetermined pattern on a conductive layer 13-2 of Cu or Au that is entirely covered on the film base 15, and this is used as a mask. The coil conductor 13 is formed by pattern etching the conductor layer 13-2.

FIG. 7 shows a state in which each portion A of the intermediate product shown in FIG. 6(a) is sampled in a predetermined shape in the step 7) above.

This process is also performed using a photolithography method. That is, as shown in FIG. 8, a photoresist (13-4) is formed in a predetermined pattern on the intermediate product, and using this as a mask, unnecessary portions of the film base 15 are etched away, as shown in FIG. It is used as a coil forming member.

Specific examples will be described below.

A coil forming member shown in FIG. 9 was prepared. The width W of the central portion 14a of this coil forming member 14 is 0.35 mm, and the width W2 of the wide portion 14b is 1.5 mm.

This coil forming member is provided with 15 coil conducting wires 13, and its cross-sectional structure is the same as that shown in FIG.

The film base 15 is made of polyimide resin or polycarbonate resin and has a thickness of 10 μm, and the coil conductor 13 is made of Cu or Au and has a thickness of 2 μm.
The insulating layer is made of SiOz or 5lsNa.

This coil forming member was manufactured by the photolithography method explained in FIGS. 5 to 8.

FIG. 11 shows a magnetic head to which the coil forming member of FIG. 9 is attached.

This magnetic head is a multi-head for electronic still cameras, and the thickness 14 of the core 1 is 60 μm, and the core gap d is 40 μm.
m, the height 2h of the winding hole 2 is 0.4, and the width l is 0.3.
It is u.

First, the second printed circuit board 20, in which the output leads 21 are formed on the insulating substrate 22, is attached to a predetermined position on the surface of the core 1. Next, the wide portion 14b is rolled up and inserted into the winding hole 2, and then the coil forming member 14 is wound around the core 1 and attached as shown in the figure.

At this time, the coil forming member 14 is brought into close contact with the core 1 so that the wide portion 14b is accurately positioned at a predetermined position on the surface of the core 1. The coil forming member 14 is attached to the core 1 using an adhesive that is previously applied to the back surface of the film base.

Next, the first printed circuit board 4-2 shown in FIG. 10 is placed on both wide portions 14b with the wiring 5 facing downward, the wiring 5 is aligned with the terminal 16, and the terminal portion is heated, as described above. Connect the two using solder.

As described above, the first printed circuit board 4-2 has the wiring 5 formed on the insulating semi-transparent substrate 6 by photolithography, and the wiring 5J: is plated with solder.

Solder plating on the wiring is accomplished by briefly dipping the first printed circuit board into a molten solder bath. The wiring is made of a metal such as Cu that has good thermal conductivity and good solder wettability, so it is instantly heated to above the melting point of the solder.
Since the base body has low thermal conductivity, it is not heated much, and a solder plating layer is formed only on the wiring.

The wide portion 14b and the first printed circuit board 4-2 are accurately aligned using the markers 7 and 8 previously attached to the surface of the core 1, respectively, as shown in an enlarged view in FIG.

Connections between the pads 5a at both ends of the wiring 50 on the first printed circuit board 4-2 and the pads 21a at the ends of the leads 21 on the second printed circuit board 20 are also made by soldering in the same manner as described above.

Further, the base 22 of the second printed circuit board 20 is provided with a window 22a so that the markers 7 and 8 can be seen.

The results of conducting a coil continuity test on 200 magnetic heads assembled as described above are shown in the table below. For comparison, the same table also lists the same test results for a magnetic head manufactured in the same manner as in the above example, except that the wiring between the terminals and the connections between the terminals and the output wires were made using wire bonding. .

As described above, the magnetic head based on the present invention has a high yield (and is easy to manufacture).

In the above example, a magnetic head is created by inserting a coil forming member into the winding hole of a core that has already been fused with glass.
It is also possible to wrap the coil-forming member around one core portion and then glass-fuse the core.

That is, the coil forming member 14 is wound around one core part, the two cores are butted together, the glass rod 10 shown by the dashed line in FIG. 11 is placed in the butt part of the winding hole 2, and the glass rod
0 is heated and melted, and core 1 is fused. In this way, the work of assembling the magnetic head becomes easier. Since a heat-resistant polyimide resin or polycarbonate resin is used for the film base, it can sufficiently withstand the temperature of glass fusing. In addition, since the coil forming member 14 is already tightly wound around the core 1 at an accurate position, it does not interfere with the fusion work, and prevents the positional deviation of the coil forming member and the deviation of the core fused portion as described above. There is no risk of this happening.

Although the present invention has been illustrated above, the above-mentioned example can be further modified based on the technical idea of the present invention.

For example, the pattern of the conducting wire of the above-mentioned film-like coil, the shape of the coil itself, etc. may be changed in various ways.

In some cases, the above-mentioned film-like coil can be wound by passing it through the winding hole multiple times, but even in this case, each film can be used while holding a large number of conductors. The ease of connection improves work efficiency and reduces mistakes. In addition, the applicable head is not limited to the balanced type, but may also be a semi-balanced type (a type in which the coil is installed at the back gap position of the core part) or a staggered type (a type in which the coil is installed only in one core part). In addition to magnetic heads, the present invention can be applied to various electromagnetic transducers using coils.

As described above, the present invention uses a coil in which a coil conductor is integrally provided on a flexible base, so the winding hole is small and the coil insertion portion has narrow intervals or gaps. However, there is no need to wind the coil wire many times as in the conventional method, and a similar coil can be created by simply passing the flexible base with four members through the winding holes. Furthermore, since the coil conductor is wirelessly connected to a conductor that is integrally provided on a base other than the flexible base, this connection is not troublesome like wire bonding, and is reliable. And easy. Therefore, productivity is greatly improved and yield is also improved.

[Brief explanation of drawings]

1 to 12 show embodiments of the present invention, in which FIG. 1 is a schematic perspective view of a magnetoresistive device, FIG. 2 is a perspective view of a coil forming member, and FIG. 3 is a perspective view of a coil forming member. Fig. 4 is a sectional view similar to Fig. 3 of a coil forming member according to another example; Fig. 5 shows an intermediate product of the coil forming member;
is a perspective view, FIG. 6 is an enlarged plan view of FIG. FIG. 8 is a sectional view showing a method of collecting a coil forming member from an intermediate product of coil forming members; FIG. 9 is a plan view of a coil forming member according to another example; FIG. 10 11 is a perspective view of a magnetic head using the coil forming member of FIG. 9, and FIG. 12 is a partially enlarged view of FIG. 11. 13 and 14 show conventional examples. FIG. 13 is a schematic perspective view of a magnetic head, and FIG. 14 is a schematic perspective view of a multi-head. In addition, in the reference numerals shown in the drawings, 1...Core portion 2...Winding hole 3...Printed circuit board 4-2...First printed circuit board 4.6...Semi-transparent base 5... -Wiring 13...Coil conductor 14...Coil forming member 14a...Central part 14b...Wide part 15...Film base 17...'4f! A edge layer 20...Second printed circuit board 21...Blade 22...Substrate. Agent Patent Attorney Hiroshi Aisaka Figure 3 Figure 5 Figure 6 Figure 7 cy t:y cy j'-AcI Figure 8 Figure 9 Nagi Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 7-'' Commissioner of the Japan Patent Office Kuro 1) Mr. Akio 1, Indication of the case 1985 Patent Application No. 299097 2, Name of the invention Electromagnetic conversion device 3, Relationship with the person making the amendment Patent applicant address Tokyo 1-26-2 Nishi-Shinjuku, Shinjuku-ku Name
(127) Konishiroku Photo Industry Co., Ltd. 4, Agent address: 0425-24-5411, FINE Building, 2-4-11 Shibasaki-cho, Tachikawa-shi, Tokyo (Ya (1) 0 Figure 11 of the drawing has been corrected as shown in the attached sheet) To do.

Claims (1)

[Claims] 1. A coil forming member in which a coil conductor is integrally provided on a flexible base is inserted into a coil winding hole in a core part, and the coil forming member is formed by a coil conductor integrally provided on a base other than the flexible base. ,
An electromagnetic transducer configured such that ends of the coil conductor are wirelessly connected to form a coil.