JPS637608A - Manufacture of flat coil - Google Patents

Abstract

PURPOSE:To improve productivity, by cutting the wound body of metal foils, in which insulating layers are laminated, by a discharge machining method. CONSTITUTION:Insulating layers 3 and 4 are laminated in the wound body of metal foils 1 by a discharge machining method. Therefore, the insulating layers 3 and 4 are slightly protruded from the metal foils 1. Insulation between the metal foils 1 is kept, and the occurrence of short circuits and the like is suppressed. By the discharge machining method, the metal foils 1 and the central core can be simultaneously cut together. Since a plurality of the wound bodies 7 can be cut one time together, the productivity of flat coils can be improved. Since a central shaft 6 and the coil are simultaneously cut by the discharge machining method, the coil having the central core comprising a high permeability material is obtained. Specified inductance is obtained with the small number of turns. With the same diameter, the higher inductance is obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing flat coils used in motors, deflection yokes, transformers, etc. The present invention relates to a method for manufacturing a flat coil, in which a central shaft made of conductive material is simultaneously cut by electrical discharge machining.

C. Summary of the Invention] The present invention comprises the steps of applying an insulating layer to a metal foil, and winding the gold IX foil provided with the insulating layer around a central shaft made of a high magnetic permeability material while thermocompression bonding, a thin metal WJ, The process of creating the one-piece body and the process of cutting the wound body to a predetermined thickness by electric discharge machining in a direction perpendicular to the central axis and simultaneously with the central axis results in high inductance, high reliability and high reliability. The aim is to manufacture a flat coil with high workability.

[Conventional technology]

Conventionally, motor coils and cathode ray tube deflection yokes have
Wire-wound coils in which copper wire is wound many times are generally used, but as these devices become smaller, thinner so-called flat coils have been developed and put into practical use.

For example, sheet coils for flat motors are made by etching a copper foil laminated to an insulating sheet in an IT-like pattern with a line width of about 50 μm, which helps make the motor thinner.

This greatly contributes to miniaturization.

However, although the sheet coil described above is extremely useful for thinning, it is difficult to mass produce because it requires extremely high precision etching technology, and because it requires special technology, it can be easily produced anywhere. That cannot be said.

- On the other hand, the idea of winding up copper foil coated with an insulating film and cutting it into rings to make flat coils has been devised, and various attempts have been made, but there are problems in terms of reliability, mass production, etc. It has not yet been put into practical use. In particular, it is difficult to cut the wound copper foil to a predetermined thickness, and when it is cut using, for example, mechanical means or a laser, the cross section is warped and defects such as short-circuiting of the coil are likely to occur. In order to solve this blurring of the cut surface, there is no choice but to polish the cut surface smoothly.
This process complicates the manufacturing process and is not suitable for mass production.

[Problem that the invention seeks to solve]

When trying to cut a copper foil enclosure to create a flat coil, conventional cutting methods do not have the capacity to justify the cost, post-processing is difficult, and production costs are high. The reality is that it has not been mass-produced.

Therefore, an object of the present invention is to provide a method for manufacturing a flat coil that eliminates the drawbacks of the above-mentioned conventional methods, which does not cause short circuits when cutting a wound body of metal foil, has a large inductance, and has a high inductance. The purpose is to manufacture highly reliable coils with high productivity.

[Means for solving problems]

The inventors of the present invention have repeatedly investigated various methods for cutting a rolled body of metal foil, and have come to the conclusion that electrical discharge machining is suitable. The present invention was completed based on such findings, and includes a process of applying an insulating layer to a metal foil, and a process of bonding the metal foil with the insulating layer with a high magnetic permeability material while thermocompression bonding. The method includes the steps of: creating a surrounding body with a metal thin film by winding it around a central axis; and cutting the wound body to a predetermined thickness by electric discharge machining in a direction perpendicular to the central axis and simultaneously with the cough central axis. It is characterized by:

[Effect]

When a rolled body of metal foil with an insulating layer laminated thereon is cut by electrical discharge machining, the insulating layer protrudes slightly beyond the metal foil at the cut surface, and insulation between the metal foils is maintained. Therefore, occurrence of defects such as short circuits can be suppressed.

Further, according to the electrical discharge machining method, the metal foil and the central core can be cut at the same time, and a plurality of wound bodies can be cut at the same time, thereby improving the productivity of the flat coil.

Furthermore, since the central axis is cut at the same time as the coil using the electric discharge machining method, the coil has a central core made of high magnetic permeability material, and the desired inductance can be obtained with a small number of turns. Larger inductance can be obtained.

〔Example〕

Hereinafter, the method for manufacturing a flat coil according to the present invention will be explained using specific examples.

To fabricate a flat coil, first, as shown in FIG. 3, an adhesive layer serving as an insulating layer is laminated onto iPI foil (1). In this example, a polymer film (2) such as a polyimide film was used to ensure insulation.
Laminate and sandwich this with two adhesive layers (3)
, (4) was coated.

Here, the thickness of the copper foil is 35 μm, and the adhesive is 1'ffl.
(3).

(4) had a thickness of 6 μm, and a 13 μm thick polyimide film was used as the polymer film (2).

Note that the polymer film (2) is not necessarily necessary.
For example, as shown in FIG. 4, it is sufficient to simply coat both surfaces of the copper foil (1) with adhesive layers (3) and (4).

A polymer film (2) or adhesive layers (3) and (4) are laminated onto a copper foil (1), which is a raw material for a flat coil, using an 'AN' as shown in FIG. That is, the polymer film (2) supplied from the unwinding/unwinding roll (11) is guided to the adhesive coating a (12), and both surfaces thereof are coated with adhesive. Next, the adhesive is dried (semi-cured) through a dryer (13), and is then pressure-bonded with the W4 foil (1) supplied from an unwinding roll (15) by a laminator (14), and then rolled onto a winding roll (16). Wind it up.

Through the above steps, as shown in FIG. 2, a raw roll of laminate (5) consisting of W4 foil (1), polymer film (2), adhesive layers (3) and (4) is obtained.

Next, the raw fabric roll of this laminate (5) is cut into a predetermined width using a cutting machine, and each is wound into a roll.

Subsequently, the laminate (5) produced in the above steps is fed out from an unwinding roll, and a central shaft (6) having a substantially triangular cross section is rolled while applying back tensioning with a tensioning roll.
to obtain a rolled body (7) of the laminate (5).

In this embodiment, when winding the laminate (5) around the central shaft (6), hot rolls energized by an air cylinder are crimped from three sides to adjust the winding state of the rolled body (7). There is.

In addition, each laminate (
5) They are bonded together by adhesive layers (3) and (4).

The central axis (6) becomes the central core when it becomes a flat coil, and is made of high magnetic permeability materials such as ferrite, iron, iron, etc. Further, the cross-sectional shape of the central shaft (6) may be changed according to the desired shape of the coil.
It can have any number of shapes such as circular, oval, quadrangular, polygonal, etc. Further, this central shaft (6) has a groove cut therein for forming an electrode terminal as shown in FIG. A conductive metal rod (8) such as a solder rod or copper is provided at the innermost end of the laminate (5) wound around the central shaft (6), and is fitted into a groove provided in the central shaft (6). It is attached and electrically connected to the innermost circumferential portion of the laminate (5) to be wound, so that when the coil is cut in the process described later, it becomes a d-direction lead-out electrode terminal.

Next, a solder rod (9) is connected along the end of the wound body (7) [the end of the winding of the laminated body (5)] so that when it is cut into a coil, it will become the other lead-out electrode terminal. Make it. As shown in FIG. 6, the solder rod (9) is
It is easily formed by extruding solder in a softened state from the nozzle (17).

FIG. 7 is an external perspective view showing a state in which the solder rod (9) is attached along the negative side edge of the winding body (7), and this state is a state in which all the constituent elements of the coil are provided. This is collectively referred to as a coil block (10).

The coil block (10) obtained in the above process is heated at a predetermined temperature in a heating furnace to completely remove the adhesive layers (3) and (4) interposed between the layers of the wound body (7). harden.

Next, as shown in FIG. 8, the coil block (1
0), the wound body (7) and the central shaft (6) are simultaneously cut at predetermined intervals by electrical discharge machining.

The electric discharge machining method described above is a non-contact machining method (energy machining method) that utilizes pulsed spark discharges at minute intervals in a dielectric liquid (cooling liquid) and the associated short arc discharges. It can also be referred to as abnormal wear of metal at points. This electrical discharge machining method is usually used for processing conductors such as forming molds, but according to the experiments of the present inventors,
It has been found that good results are also obtained when cutting a laminate of metal foil and insulating stone and when cutting a central shaft (6) made of a material exhibiting high magnetic permeability.

Here, the center! J] (6) along with the coil is extremely important in terms of flat coil performance.

That is, by providing a high magnetic permeability material at the center of the coil, the inductance of the coil is affected, and the inductance increases. Therefore, a predetermined inductance can be obtained with a small number of coil turns (small winding diameter), and a larger inductance can be obtained with coils having the same shape and diameter.

In order to perform the above electric discharge machining, the above coil block (10)
may be soaked in the machining fluid (18), and pulsed power may be applied from plate electrodes (19) arranged at predetermined intervals in the longitudinal direction of the intermediate shaft (6). In this example, 20A, 40
~50 V (using DNR, peak '7: tilOA
A pulsed power supply with a pulse width of 3 μsec on and 6 μsec off was applied. Further, as the machining fluid (18) during electrical discharge machining, water or petroleum-based machining fluid (for example, kerosene) can be used.

In addition, in this embodiment, the central axis (6) of the coil block (10) is fixed to the rotating shafts (20) and '(21),
The wound body (7) was cut at a portion corresponding to each side of the triangular shape of the central axis (6) while rotating by 120 degrees.

The coil blocks (10) do not necessarily need to be cut one by one; for example, as shown in FIG. The cutting may be performed using a shaped electrode (19).

In any case, when performing the electrical discharge machining, it is necessary to ground the coil block (10) side. For example, as shown in FIG. 10, the coil block (10)
may be placed on a conductive metal fixture (22), and this fixture (22) may be grounded.

By the electric discharge machining method described above, the coil block (10) is formed into a coil (23) having a predetermined thickness, as shown in FIG.
) is cut off. Figure 12 shows the flat coil (23)
This shows the external shape of the .

The obtained flat coil (23) is made up of densely laminated copper foil (1), adhesives (3), (4), and polymer film (2), and is extremely thin, and the contact area of the electrode terminals is also small. Since it can be formed over a wide range of areas with high connection reliability, it is useful as a motor coil.

Furthermore, when the present inventors observed the cut surface obtained by the electrical discharge machining using a microscope, as shown in FIG.
, (4) ) protruded from the copper foil (1), and the insulation between the laminated copper foils (1) was completely maintained.

The flat coil (23) produced through these steps is subjected to a terminal masking process, a resin coating process, and an inductance 1 conduction resistance, as required.
After going through inspection processes such as insulation tests, it is assembled into the motor.

〔Effect of the invention〕

As is clear from the above description, in the present invention,
Since the roll of metal foil laminated with an insulating layer is cut using electrical discharge machining, the metal foil and center core can be cut at the same time, and multiple enclosures can be cut at the same time. This improves the productivity of flat coils.

Furthermore, since the metal foil and the center core can be formed together at the same time, flat coils can be easily produced without the need for special processing of the center core for each coil.

In the cut surface of the wound body produced by the electric discharge machining method of the present invention, the insulating layer is in a state slightly protruding from the metal foil, so insulation between the gold foils is maintained and defects such as short circuits are suppressed. It will be done. Therefore, a highly reliable flat coil can be manufactured.

Furthermore, when producing the flat coil, the high magnetic permeability material that is the central axis is also cut at the same time, so it is possible to produce a flat coil with large inductance.

The method of the present invention does not require special techniques or high precision, and is extremely simple, so it can be said to have high practical value.

[Brief explanation of drawings]

1 to 13 show an example of a method for manufacturing a flat coil to which the present invention is applied according to the process order, and FIG. 1 is a schematic diagram showing the step of forming an insulating layer on copper foil, and FIG.
The figure is a perspective view of the appearance of the raw coil with an insulating layer attached, Figure 3 is an enlarged sectional view of the main part of the raw coil, and Figure 4 is an enlarged cross-section of the main part of the raw coil when no polymer film is used. Fig. 5 is a schematic perspective view showing the state before the coil is wound around the central shaft, and Fig. 6 is a schematic perspective view showing the state before winding the coil around the central shaft. Fig. 7 is an external perspective view showing the process of connecting the solder rods that become the IT poles, Fig. 7 is an external perspective view of the coil block, Fig. 8 is a schematic side view showing the cutting process using electrical discharge machining, and Fig. 9 is the coil block. Figure 10 is a schematic perspective view showing the arrangement of electrodes for simultaneously cutting the coil blocks.
Figure 1 is an external perspective view showing the coil block after cutting.
FIG. 2 is an external perspective view of the obtained flat coil, and FIG. 13 is an enlarged sectional view of the main part showing the vicinity of the cut surface obtained by electrical discharge machining. 1...Metal foil (W4 foil) 3.4...Adhesive layer 6...Central axis 7...Wound body Patent applicant Sony Chemical Co., Ltd. agent Patent attorney Sakae Kobu Mima Enso - Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. LJ Fig. 9 Fig. 12 Fig. 11 Fig. 13 Issued by the head of procedure March 30, 1986 Patent side No. 152204 2, Name of the invention Method for manufacturing flat coil 3, Relationship with the case of the person making the amendment Patent applicant representative director Norio Yamaguchi 4, agent 583. Engineering. . Yes, () Voluntary action 6, Subject of amendment 7, The statement in the "Claims" column of the description of the contents of the amendment is amended as shown in the attached sheet. The description "thermocompression bonding" on page 2, line 7 of the specification is amended to read "crimping". The description "thermocompression bonding" on page 6, line 4 of the specification is amended to read "crimping". (Above) The scope of the appended patent claims: ``A step of applying an insulating layer to a metal foil, and winding the metal foil provided with the insulating layer around a central shaft made of a high magnetic permeability material while pressing the metal foil to form a metal thin film wound body. 1. A method for manufacturing a flat coil, comprising: a step of cutting the wound body to a predetermined thickness by electric discharge machining in a direction perpendicular to the central axis thereof and simultaneously with the central axis. ”

Claims (1)

[Claims] A step of applying an insulating layer to a metal foil, and winding the metal foil provided with the insulating layer around a central shaft made of a high magnetic permeability material while thermocompression bonding to create a metal thin film wound body. A method for manufacturing a flat coil, comprising the steps of: cutting the wound body to a predetermined thickness by electric discharge machining in a direction perpendicular to the central axis thereof and simultaneously with the central axis.