JPH0578159U - Thin coil - Google Patents

Abstract

(57) [Summary] [Purpose] To stabilize the coil winding shape with uniform tightening and uniform interlayer thickness. [Structure] The innermost corners 3, 3, ...
It is formed to have a curved surface with a radius of curvature of 5 mm to 1.0 mm.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a thin coil. More specifically, the present invention relates to a thin coil having a substantially triangular planar shape.

[0002]

[Prior Art]

 For example, in a face-to-face motor such as a small 8 mm VTR motor, a substantially triangular thin coil suitable for annular arrangement is used as shown in FIG. 3 in order to increase the space factor of the coil. There is. This coil is made by coating a foil of conductive material, such as copper foil, coated on one side with an adhesive on a triangular core jig, winding it, forming it into a predetermined shape by forming, and then fixing it with the adhesive. It is a slice from.

The corner portion (triangular ridge portion) of the innermost layer of this thin coil has conventionally been an acute angle or substantially 0.2 mm, which is similar to an acute angle, in order to make it more fan-shaped and increase the space factor. It is formed on a curved surface with a small radius of curvature. However, since the corners of the winding jig are substantially acute angles, the tightening force when winding the copper foil is different and uneven between the corners and other parts. The shape of the rod-shaped coil obtained by winding it around the jig becomes unstable, and the layer is likely to swell in the part away from the corners of the triangle. Therefore, forming is performed using a compulsory jig after the winding process.

On the other hand, since the copper foil generally used as the conductive foil film has a thickness of about 5 μm to 30 μm and is soft, the cut surface is welded or burrs are generated during slicing, which causes a short circuit (short circuit) between layers. I will end up. Therefore, both end faces of the thin coil are subjected to end face treatment by etching so that each layer of copper foil is clearly separated by the insulating material layer and the adhesive layer.

[0005]

[Problems to be solved by the device]

 However, the looseness of the rod-shaped coil that can be corrected by forming is slight, and a large deformation cannot be corrected. In addition, in this bulged portion, the etching liquid easily enters the adhesive layer between the copper foils, the adhesive swells with the etching liquid and the coil is deformed, or the adhesive pops out from the end face of the coil. I have a problem. For this reason, the coil that has been greatly deformed must be discarded, resulting in poor yield.

Further, in the bar-shaped coil wound around the core jig, the corner portions of the triangle are tightened more strongly than the other portions, so the innermost copper foil is extracted together when the core jig is removed. There is also a problem that causes it.

An object of the present invention is to provide a thin coil having a uniform tightening and interlayer thickness and a stable coil winding shape.

[0008]

[Means for Solving the Problems]

 In order to achieve such an object, the present invention is a thin coil formed by winding a conductive foil into a substantially triangular shape, and the corner portion of the innermost layer of the coil has a radius of curvature of approximately 0.5 mm to 1.0 mm. It has a curved surface. The radius of curvature of the corner of the innermost layer of the coil is 0. If it is less than 5 mm, a phenomenon occurs in which only the corner portion is tightened when the foil film is wound. If it is larger than 0 mm, the tightening will be uniform, but the area occupied by the coil will be small and the motor characteristics will deteriorate.

[0009]

[Action]

 When the radius of curvature of the corner of the innermost layer of the coil, that is, the radius of curvature of the corner of the outer peripheral surface of the substantially triangular winding jig is set to approximately 0.5 mm to 1.0 mm, the corners and the plane between them Since the coil tightening force is transmitted to and from the part without being interrupted, the coiling force is uniformly applied to the entire circumference and the coil is wound. For this reason, partial tightening at the corners of the coil is avoided, and evenly tightened so that the thickness of the adhesive layer between the layers of the coil is constant, resulting in a substantially triangular coil. Swelling in the space is suppressed.

[0010]

【Example】

 Hereinafter, the configuration of the present invention will be described in detail based on the embodiments shown in the drawings.

FIG. 1 shows an embodiment of the thin coil of the present invention. For example, as shown in FIG. 1, the thin coil 1 is obtained by applying an adhesive (not shown) to a foil film of a conductive material having a thickness of about 30 μm, for example, a copper foil 2 coated on one side with an insulating material (not shown). It is wound into a substantially triangular shape and solidified. Each of the corners 3, 3, 3, 3 of the substantially triangular coil 1 is composed of a curved surface having a half radius of curvature of 0.5 mm to 1.0 mm, more preferably about 0.5 mm. Further, the corners 3 of the innermost layer of the coil and the surfaces 4, 4, 4 connecting the corners 3 are composed of substantially flat surfaces. Further, the surface 5 corresponding to the base of the triangle is composed of a curved surface having a large radius of curvature corresponding to the outer diameter of the motor.

The thin coil 1 is, for example, as shown in FIG. 2, a substantially triangular shape obtained by winding a copper foil 2 having an insulating material 6 and an adhesive 7 applied on at least one surface around a winding jig 8. It is obtained by cutting the rod-shaped copper foil wound body of. The core jig 8 is composed of a split mold, and the stick-shaped winding body of the copper foil 2 is hardened by hardening the adhesive 7 and then disassembled and taken out. Then, after slicing to a predetermined thickness using a wire saw or the like, burrs and the like on the cut surface are removed by etching or the like to obtain a thin coil 1 as shown in FIG.

Further, the thin coil 1 has an electrode terminal formed at a corner portion 9 of the outermost copper foil, which is shown by hatching, or an exposed electrode in which the insulating material layer is removed is formed. There is. Further, electrode terminals are similarly formed on the surface 4 of the innermost layer of the copper foil, which is shown by hatching, or an exposed electrode is formed by removing the insulating material layer at that portion.

The thin coil 1 configured as described above is inserted into a recess 12 of a substrate 11 formed of synthetic resin or the like as shown in FIG. To form an integrated coil. In the recess 12 of the substrate 11, for example, a coil connection frame circuit 13 for wiring the thin coils 1, 1, ..., 1 is provided. The exposed electrode (or electrode terminal) portion of the outer layer and the exposed electrode (or electrode terminal) portion of the innermost layer are placed. Therefore, a paste solder is placed on the edge portion of the coil 1 above the exposed electrode portion by screen printing, or a paste jig is directly injected onto the exposed electrode portion on the side surface of the coil using a supply jig. Apply it and run it in a reflow furnace to connect it. Or soldering is done manually by the operator. At this time, the exposed electrode portion of the outermost layer is formed at the corner portion 3 of the side 5 arranged along the outermost periphery of the motor, so that a gap between the adjacent coil 1 is ensured as much as possible. At this time, since the corners of the coil have a radius of curvature of 0.5 mm to 1.0 mm in the innermost layer, a considerably large curved surface is formed, which facilitates soldering.

It should be noted that the above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention. For example, the term “substantially triangular” as used in the present specification means not only a regular triangle having an angled corner rounded with a predetermined radius of curvature or an isosceles triangle, but also a corner closer to the center of the rotor shaft than other corners. It also includes the case shown in Fig. 1, which is much larger and has a shape close to a ladder, and includes all that fall within the range of a fan in which a circle is evenly divided.

[0016]

[Effect of the device]

 As is clear from the above description, the thin coil of the present invention is a thin coil formed by winding a conductive foil into a substantially triangular shape, and the innermost corner portion of the coil is approximately 0. Since a curved surface with a radius of curvature of 5 mm to 1.0 mm is formed, the coil shape can be stably formed with a uniform interlayer thickness without degrading the motor characteristics. That is, when the radius of curvature of the corner portion of the coil is in the range of about 0.5 mm to 1.0 mm, the difference between the tightening force of the coil at this corner portion and the tightening force at other portions becomes small, Swelling between the coil layers is suppressed in the substantially flat surface portion between the corners, and the uniform thickness of the adhesive layer can be maintained. Therefore, the etching solution does not partially invade the adhesive layer and swell during the etching end face treatment, which does not deform the coil or eject the adhesive.

In addition, since the thin coil of the present invention does not cause the coil shape to partially bulge, correction by forming after winding is unnecessary, and the forming process can be omitted. In addition, defective products due to swelling of the adhesive and defective molding are reduced, and the yield is improved.

Further, since the tightening force of the coil is made uniform over the entire circumference, the innermost layer of the coil is not peeled off when the core jig is removed.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a thin coil of the present invention.

FIG. 2 is a perspective view showing an example of a process of manufacturing a thin coil.

FIG. 3 is a diagram showing an example of use of a thin coil, (A) is a plan view and (B) is a sectional view.

[Explanation of symbols]

 1 Thin coil 3 Corner

Claims (1)

[Scope of utility model registration request] 1. A thin coil formed by winding a conductive foil in a substantially triangular shape, wherein an innermost layer of the coil has a corner portion having a curved surface with a radius of curvature of approximately 0.5 mm to 1.0 mm. Thin coil that does.