JPS63188906A - Flat coil and its manufacture - Google Patents

Abstract

PURPOSE:To prevent the exfoliation of a conductor foil from being caused at a winding-terminating part and to prevent an electrical loop from being generated at a metal reinforced layer by installing an insulating resin layer at the winding-terminating part. CONSTITUTION:An insulating resin layer 4 is coated in a belt-like shape at a winding-terminating part 1a at the outermost circumference of a coil part 1; the winding-terminating part 1a is sealed. A metal reinforced layer 5 is plated on the outer circumference face excluding the insulating resin layer 4 at this coil part 1; as a result, the thickness of a wound part at the outermost circumference out of the wound conductor foil layers is composed of the thickness of the conductor foil itself and that of the metal reinforced layer 5. The mechanical strength of a flat coil 10 which is constituted in this manner is enhanced by the metal reinforced layer 5; the coil is resistant to the deformation or the like. In addition, because the metal reinforced layer 5 is divided by the insulating resin layer 4, it does not generate an electrical loop by itself and does not lower the performance of the coil part 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flat coil used in motors, deflection yokes, transformers, etc., and further relates to a manufacturing method thereof.

[Summary of the invention]

This invention! In a flat coil made by cutting a wound body in which an insulating film and a conductive foil are alternately wound to a predetermined thickness,
The end of the winding is sealed with an insulating resin layer, and the outer periphery is reinforced with a metal reinforcing layer to improve strength.Furthermore, the periphery is plated with metal before cutting. This aims to improve the cutting speed and prevent breakage at the outer periphery, thereby providing a manufacturing method with excellent productivity.

[Conventional technology]

Conventionally, motor coils and cathode ray tube deflection yokes have
Wire-wound coils in which copper wire is wound several times are generally used, but as devices become smaller, thinner so-called flant 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 a spiral shape with a line width of about 50 μm.This is used to make the motor thinner and smaller. He has contributed greatly.

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 it is difficult to mass produce because it requires special technology. There is no way that it can be made in the same way.

Therefore, the idea of creating a wound body by winding copper foil coated with an insulating film and cutting this into rings to create a flat coil was proposed, and the applicant of the present application filed, for example, Japanese Patent Application No. 61-1981.
In the specification of No. 32513, a method was proposed in which the above-mentioned wound body was cut by electric discharge machining to efficiently produce a highly reliable coil without causing short circuits or the like.

[Problems to be Solved by the Invention] By the way, as a result of further study by the present inventors, when trying to cut a wound body in which a conductive foil and an insulating film are alternately wound by electrical discharge machining, In particular, if extremely thin conductor foil is used, there is a risk that the strength of the conductor foil at the outer periphery of the coil will be insufficient and so-called curling will occur, slowing down the cutting speed, or the conductor foil at the outer periphery will be cut and the coil will become defective. It has been found.

In the worst case, amputation may become impossible.

Furthermore, when looking at the flant coil itself, there remained problems such as deformation due to cutting and insufficient strength of the terminal portion.

The present invention was proposed in view of the above-mentioned problems, and an object of the present invention is to provide a flant coil having excellent mechanical strength and even higher reliability.

Furthermore, it is an object of the present invention to provide a method for manufacturing a flat coil that allows good cutting even when the conductor foil strength is insufficient, has a fast cutting speed, and is advantageous in terms of productivity.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the flant coil of the present invention is produced by cutting a wound body in which an insulating film and a conductive foil are alternately wound to a predetermined thickness. In a flat coil, the outermost periphery of the above-mentioned body is made of a conductive foil, an insulating resin layer is provided at the end of the winding of the wound body, and a portion other than the end of the winding is covered with a metal reinforcing layer. The flat coil manufacturing method of the present invention includes the steps of: winding an insulating film and a conductive foil around a central axis so that the outermost periphery is a conductive foil to create a wound body; , a step of applying an insulating resin to the winding end portion of the wound body, a step of applying metal plating to the wound body coated with the insulating resin, and a step of applying a metal plating to the wound body coated with the above-mentioned insulating resin; The method is characterized in that it has a step of cutting it to a predetermined thickness by electric discharge machining in the direction of cutting.

[Effect]

In the flat coil of the present invention, mechanical strength is ensured by providing a metal reinforcing layer on the outermost periphery, and connection reliability of the terminal portion is also ensured.

On the other hand, by providing an insulating resin layer at the end of the winding,
Peeling of the conductor 7rI at the end of the winding is prevented, and at the same time, electrical loops in the metal reinforcing layer E are prevented.

In addition, 1. Formation of the metal reinforcing layer is advantageous when manufacturing a flat coil, and by increasing the strength of the outer peripheral portion of the wound body, processing conditions can be strengthened, and cutting speed can be improved. Furthermore, the metal reinforcing layer protects the conductor foil on the outer periphery, making it possible to cut a wound body using extremely thin conductor foil, which was difficult to cut in the past.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

As shown in Fig. 1, the flat coil (10) of this embodiment has a coil portion (1) that is a wound body of conductive foil that is wound and laminated via an insulating film until the desired characteristics are obtained. in,
Terminals (2) and (3), which serve as external connection parts, are attached to the inner end and outermost surface, respectively, and the outermost part is surrounded by a metal reinforcing layer (5). It has become.

The conductor foil constituting the coil part (1) is made of copper foil, etc.
A metal foil made of an electric metal material is used, and an adhesive layer is laminated as interlayer insulation.

As the interlayer insulating film, this adhesive layer may be formed on one or both sides of the conductor foil, or a polymer film such as a polyimide film may be laminated to ensure insulation. Two adhesive layers may be formed sandwiching this. However, in any case, the conductor foil should face the outermost peripheral surface of the coil portion (1).

Terminals (2) and (3) of the coil (10) are made by directly soldering a bar-shaped conductive metal to the winding start position [i.e., the inner circumferential surface of the coil] and the winding end position (i.e., the outer circumferential surface of the coil) of the conductor foil. When mounting the coil (10), these terminals (2) and (3) can be soldered to the designated terminals to achieve mechanical connection and electrical continuity. It is possible. Terminal <2)
, (3) is a cylindrical shape with a circular cross section in this example, but it is not limited to this, and can be changed as appropriate, for example, to a semicircular cross section. Furthermore, the positions of the terminals (2) and (3) are arbitrary as long as they are on the inner peripheral surface and the outer peripheral surface of the wound body.

On the other hand, the winding end (la) at the outermost circumference of the coil part (1)
An insulating resin layer (4) is applied and formed in a band shape, and the end portion (1a) of the winding is sealed.

In addition, a metal reinforcing layer (5) is formed by plating on the outer circumferential surface of the coil portion (1) except for the insulating resin layer (4), so that it is wrapped around the outermost part of the conductor foil. The rotated portion has a thickness I'7- which is the sum of the thickness I19 of the conductor foil itself and the thickness of the metal reinforcing layer (5).

The flat coil (10) having such a configuration has improved mechanical strength due to the metal reinforcing layer (5), and is strong against deformation and the like. In addition, since the terminal (3) provided on the outer peripheral surface is wrapped in the metal reinforcing layer (5) and tightly adhered to the conductive foil, the connection state is ensured, and the terminal (3) The installation strength has also increased.

Since the metal reinforcing layer (5) is separated by the insulating resin layer (4), it does not constitute an electrical loop by itself and does not reduce the performance of the coil portion (1).

Next, a method for manufacturing the above-mentioned flat coil will be explained.

To manufacture a flat coil, first, as shown in FIG. 4, an adhesive layer serving as an insulating layer is laminated onto a copper foil (11). In this example, in order to ensure insulation, a polymer film (12) such as a polyimide film is laminated, and two adhesive layers (13) are placed between them.
(14) was coated. Here, the above copper foil (1
) thickness is 35 μm, adhesive layer (13), (14)
The thickness of each film is about 6 μm, and a polyimide film with a thickness of about 13 μm is used as the polymer film (2), but it is of course not limited to this, and the thickness of each film can be set as appropriate. Bye.

Note that the polymer film (12) is not necessarily necessary; for example, as shown in FIG. The agent layer may be provided on only one side. In particular, in order to have the copper foil (11) facing the outermost surface, it is convenient to form the adhesive layer on only one side.

The polymer film (12) or the adhesive jiJ (13), (1,1) is laminated onto the copper foil (11) using an apparatus as shown in FIG. That is,
The polymer film (
12) is introduced into the adhesive applicator (22), and both sides thereof are coated with adhesive. Next, the adhesive is dried (semi-cured) through a dryer a (23), and then the copper foil (11) supplied from the unwinding roll (25) is bonded by the laminator (24), and then the adhesive is bonded to the winding roll (16). Wind it up.

With the above, as shown in FIG. 3, the copper foil (11) is formed.

Polymer film (12), adhesive layer (13), (1
A raw fabric roll of the laminate (15) consisting of 4) is obtained.

Next, as shown in FIG. 6, a conductive metal rod (17) is attached to one end of the laminate (15), and a groove (16a) is formed to match the shape of the metal rod (17). It is wound around a central shaft (16) having a diameter.

During winding, the raw fabric roll of this laminate (15) is sent out from the roll (29), and as shown in FIG. 7, the central axis (16) having a substantially triangular cross section is to obtain a rolled body (18) of the laminate (15). In this embodiment, when the laminate (15) is wound around the center shaft (16), the heat roll (3
2) is crimped from three sides to adjust the winding condition of the wound body (18). Moreover, at this point, the illumination foils (11) of each laminate (15) are bonded by the adhesive layers (13) and (14) by the pressure bonding of the heat roll (32). The external shape of the resulting wound body (18) is shown in FIG. 8. The copper foil (11) must be exposed at the outermost periphery of this wound body (18), so the laminate (15) Care must be taken regarding the winding direction. Further, when adhesive layers are formed on both sides, it is preferable to remove the adhesive layer near the winding end only on the outer circumferential surface side in advance.

The cross-sectional shape of the central axis (16) may be changed depending on the shape of the desired coil, and may be circular or oval.

It can have various shapes such as a quadrangle and a polygon.

Next, the end of the wound body (18) (the laminate (15)
A solder rod (19) is connected along the winding end of ) so that it becomes the other lead electrode when it is cut into a coil. This solder rod (19) is easily formed by extruding solder in a softened state from a nozzle (33), as shown in FIG.

Next, as shown in FIG. 10, an insulating resin layer (40) is applied and formed along the end portion (18a) of the winding body (1B). Various resin materials can be used as the material for this insulating resin layer (40).

Furthermore, the rolled body (1) provided with the insulating resin layer (40)
For 8), electrolytic plating is applied and metal reinforcement N (50) is applied.
Cover the entire surface. Possible electrolytic plating includes hole plating, nickel plating, zinc plating, chrome plating, solder plating, and tin plating.

By applying this electrolytic plating, the above-mentioned wound body (18)
Is there a metal supplement in the conductor part? A Jffi layer (50) is formed, and a metal reinforcing layer (
50) is never formed, and this metal reinforcing layer (50)
) does not form an electrical loop.

FIG. 11 shows a wound body (18) with the metal reinforcing layer (50)
In this state, the coiled body (18) of copper'; f3 (11), the conductive metal rod (17) that becomes one electrode of the coil, and the All the components of the coil are now assembled, including the solder rod (19), the insulating resin layer (40), and the metal reinforcing layer (50). Therefore, these are combined into a coil block (2
0).

The coil block (20) obtained in the above steps is heated at a predetermined temperature to completely cure the adhesive Ji (13) and (14) interposed between the layers of the wound body (18), and then , as shown in FIG. 12, the coil block (20
) is cut at predetermined intervals using 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 consumption of metal at a point. This electrical discharge machining method is usually used for processing conductors, such as forming molds, but it also shows good results when cutting laminates of metal foil and insulating layers.

In order to perform the above electric discharge machining, the above coil block (20)
is immersed in a machining fluid (35), and pulses N and a are applied from plate electrodes (36) arranged at predetermined intervals in the longitudinal direction of the central axis (16). Furthermore, water or a petroleum-based machining fluid (for example, kerosene) can be used as the machining fluid during electrical discharge machining.

In addition, in this embodiment, the central shaft (16) of the coil block (20) is fixed to the rotation shafts (37) and (38),
The wound body (18) was cut at a portion corresponding to each side of the triangular shape of the central axis (16) while rotating by 120 degrees.

The coil blocks (20) do not necessarily need to be cut one by one; instead, a plurality of coil blocks (20) may be arranged in parallel and cut at the same time by plate-shaped electrodes (36) arranged at predetermined intervals. You can do it like this.

When performing the above electric discharge machining, the above coil block (20
) side must be grounded. Therefore, a method for establishing this grounding is illustrated in FIG. 13. In this example, the coil block (20) is attached to a conductive metal fixture (39).
l! In this method, the fixing metal fitting (39) is grounded.

By the electric discharge machining method described above, the coil block (20) is cut into flat coils having a predetermined thickness, as shown in FIG. During electric discharge machining, since the metal reinforcing layer (50) is formed, the machining conditions can be made stricter and the cutting speed can be improved. This cutting speed is particularly influenced by the speed at the start of cutting, and the provision of the metal reinforcement JW (50) is significant. In addition, the mechanical strength of the outer periphery of the coil has been increased by forming the metal reinforcement N (50), so it is now possible to cut ultra-thin copper foil, which could not be cut conventionally, and deformation after cutting is reduced. It can be suppressed.

In fact, the present inventors created a flat coil under the following conditions and confirmed that the cutting time and yield were improved.

That is, first, adhesive (
The adhesive coated copper foil was coated with a dry thickness of 5 μm) and wound to form a rolled body as shown in FIG. 9.

Next, a resin composition having the composition shown below was applied in the form of a band to the end of the winding of the wound body. The coating thickness was 35 μm.

Resin composition Butyral resin 100 parts by weight (manufactured by Block Chemical Co., Ltd., Eslenoku BX-1) Phenol resin
60 heavy duty section (manufactured by Sumitomo Juret Co., Ltd., P
R50838) Vine mix 1
The solid content was adjusted to 20% using 50 parts by weight of toluene, 330 parts by weight, and 120 parts by weight or more of acetone.

Next, the rolled body coated with the resin composition was placed in a copper pyrophosphate plating bath, and electrolytic plating was performed.

Plating conditions were: current density 3A/da'', plating time 60
The plating thickness was 45 μm.

The rolled body subjected to the above plating treatment was cut by electric discharge machining to create a flat coil. The cutting time and yield were compared with those without plating treatment. The results are shown in the table below.

As is clear from this table, the cutting time is approximately 38%
7 The yield was improved by about 30%. Also,
The resin composition layer could also be cut without any problem.

〔Effect of the invention〕

As is clear from the above explanation, since the flat coil of the present invention has a metal reinforcing layer on its outermost periphery, its mechanical strength is improved and the occurrence of deformation is extremely low. ing.

Furthermore, the metal reinforcing layer allows the connection terminal to be attached in a stable manner, and in particular, the terminal strength can be improved.

Furthermore, since this metal reinforcing layer is provided with an insulating resin layer, no electrical loop is formed and the performance of the coil is not reduced.

On the other hand, in the manufacturing method of the present invention, a metal reinforcing layer is provided in advance by metal plating on the outer periphery of the wound body made of conductive foil, and then it is cut by electrical discharge machining. Even when foil is used, good cutting is possible, and cutting speed can also be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an embodiment of a flat coil to which the present invention is applied. Figures 2 to 14 show an example of a method for producing a flant coil to which the present invention is applied in accordance with the process order. Figure 2 is a schematic diagram showing the process of forming an insulating layer on copper foil, and Figure 3 is an insulating Fig. 4 is an enlarged sectional view of the main part of the coil original fabric with layers applied thereto; Fig. 5 is an enlarged sectional view of the main part of the coil original fabric when no polymer film is used; Figure 6 is a schematic perspective view showing the starting state of winding the original coil, Figure 7 is a schematic diagram showing the process of winding around the central axis, and Figure 8 is an external perspective view of the wound body wound around the central axis. , FIG. 9 is an external perspective view showing the process of connecting solder rods that become electrodes, FIG. 10 is an external perspective view showing the insulating resin layer coating process, FIG. 11 is an external perspective view showing the metal agate process, and FIG. FIG. 13 is a schematic side view showing a cutting process by electric discharge machining, FIG. 13 is a schematic diagram showing a method of connecting a ground to a coil block, and FIG. 14 is an external perspective view showing the coil block after cutting. 1... Coil portion 2.3... Terminal 4... Insulating resin layer 5... Metal reinforcing layer Patent applicant: Sony Chemical Co., Ltd. Representative Patent attorney: Koike Miwami Tamura Sakae - Figure 1 Figure 2 Figure 12 Figure 13 Figure 14 %s('v') Figure 9 Figure 10 Figure 11

Claims (2)

[Claims] (1) In a flat coil formed by cutting a winding body in which an insulating film and a conductive foil are alternately wound to a predetermined thickness, the outermost periphery of the winding body is the conductive foil, and the winding body is A flat coil characterized in that an insulating resin layer is provided at a winding end, and a portion other than the winding end is covered with a metal reinforcing layer. (2) A step of creating a wound body by winding an insulating film and a conductive foil around a central axis so that the outermost periphery becomes a conductive foil, and applying insulating resin to the end of the winding of the wound body. a step of applying metal plating to the wound body coated with the insulating resin; and a step of cutting the wound body to a predetermined thickness by electrical discharge machining in a direction perpendicular to the central axis. A method for manufacturing a flat coil, comprising: