JP2020009836A - Coil substrate - Google Patents

Abstract

To provide a coil substrate that generates high torque.SOLUTION: In a coil substrate 20, a line-to-line distance (pitch) G1 of spiral wirings 24F, 24F of a coil is formed at a narrow pitch. Since the distance between spiral wirings that make up the coil is a narrow pitch, in the coil substrate 20, an area of a coil inner side CE on a center side is not reduced, so that high torque can be obtained with a small size.SELECTED DRAWING: Figure 2

Description

The present invention relates to a coil board constituting an armature of a DC motor.

Patent Literature 1 discloses a coil body formed by stacking laminated coils on a cylindrical flexible substrate. Patent Literature 2 discloses a coreless armature in which one coil substrate is circumferentially wound a plurality of times via an insulating sheet to form a cylindrical shape.

JP-A-5-276699 JP 2011-87437 A

[Issues in Patent Literature]
In Patent Literature 1, it is considered that it is difficult to obtain a high torque with a small DC motor because it is not wound a plurality of times with one rotation in the circumferential direction. In Patent Document 2, since the upper layer and the lower layer are connected via solder, the solder is expected to soften due to heat generated by the motor, and it is considered difficult to increase the reliability of the motor to which centrifugal force is applied. Further, it is presumed that the solder has a high resistance value and it is difficult to increase the efficiency.

A coil substrate according to the present invention is provided on a cylindrical flexible substrate having a first surface and a second surface opposite to the first surface, and on the first surface and the second surface of the flexible substrate. And a via conductor made of copper plating penetrating through the flexible substrate and connecting the first surface wiring and the second surface wiring. Further, the distance between the spiral wirings constituting the coil is 0.002 mm or more and 0.5 mm or less.

A coil substrate according to another aspect of the present invention includes a cylindrical flexible substrate having a first surface and a second surface opposite to the first surface, and the first surface and the second surface of the flexible substrate. And a via conductor made of copper plating that penetrates through the flexible board and connects the first surface wiring and the second surface wiring. One half turn of the coil is formed on the first surface side, and the remaining half turn is formed on the second surface side, and adjacent turns are arranged while being shifted.

[Effects of Embodiment]
According to the embodiment of the present invention, since the line-to-line distance of the spiral wiring constituting the coil is narrow, the area inside the coil on the center side is not reduced, and a small and high torque can be obtained. Coils made of spiral wiring provided on the first surface and the second surface of the flexible substrate are connected by via conductors made of copper plating penetrating the flexible substrate. Therefore, unlike solder connection, it has high reliability and high efficiency can be realized because current flows through the low-resistance via conductor.

According to another aspect of the present invention, half of one turn of the coil is formed on the first surface side, and the other half turn is formed on the second surface side, and adjacent turns are arranged while being shifted. . Since all coils can be formed in the same size, a small and high torque can be obtained. A coil composed of wiring provided on the first surface and the second surface of the flexible substrate is connected by a via conductor made of copper plating penetrating the flexible substrate. Therefore, unlike solder connection, it has high reliability and high efficiency can be realized because current flows through the low-resistance via conductor.

FIG. 1A is a cross-sectional view of a DC motor using the coil substrate of the first embodiment, FIG. 1B is a developed plan view of the coil substrate, and FIG. 1C is a perspective view of the coil substrate. is there. FIG. 4 is a diagram illustrating coil connection of a coil board according to the first embodiment. Explanatory drawing which shows some coils of the coil board of 2nd Embodiment. 4A is a schematic diagram illustrating a configuration of a coil of the coil substrate, FIG. 4B is a schematic diagram illustrating a cross-sectional shape of the coil of the coil substrate, and FIG. 4C is a plan view of the coil substrate. It is. FIG. 5A is an explanatory diagram of an area inside the coil of the coil substrate according to the first embodiment, and FIG. 5B is an explanatory diagram of an inner diameter of a coil according to a modification of the first embodiment.

[First Embodiment]
FIG. 1A is a cross-sectional view of a DC motor 10 using the coil board of the first embodiment.
The DC motor 10 includes an armature (rotor) 30 including the coil substrate 20 of the first embodiment, a magnet 48, an output shaft 50, a commutator 52, a brush 54, an angle detecting magnet 56, a Hall element 58 and a cable 60. The Hall element 58 is arranged at a position facing the angle detecting magnet 56. The angle detecting magnet 56 is used for detecting an angle, a rotation direction, and a speed.

FIG. 1B is a developed plan view of the coil board, and FIG. 1C is a perspective view of a coil board 20 constituting the armature 30.
The coil substrate 20 includes coils C1, C2, C3 formed by plating patterns on a flexible substrate 22 made of polyimide, a commutator (motor internal terminal) 52 connected to the coils C1, C2, C3, and coils C1, C2. , C3, and an angle detecting magnet 56 arranged at a position corresponding to C3. The commutator (motor internal terminal) 52 is made of a metal plate having abrasion resistance to the brush, and is arranged on connection wiring (not shown) formed simultaneously with the coils connected to the coils C1, C2, and C3. Although seven coils C1 to C7 are arranged on the coil substrate 20, only three coils C1, C2, and C3 are shown in FIG. The surface of the angle detecting magnet is divided into three or four by a groove provided on the angle detecting magnet 56 for increasing the angle detecting accuracy of the motor. As shown in FIG. 1C, the coil substrate 20 is wound 2.5 turns in the circumferential direction (axial direction of the motor) so as to surround the cavity AH.

The coil board 20 of the first embodiment has the effect that the commutator (motor internal terminal) 52 and the angle detecting magnet 56 are provided together with the coil on one flexible board, so that the structure is simple and easy to manufacture. .

As shown in FIG. 1C, the coil substrate 20 wound by 2.5 turns constitutes an armature 30. In the coil substrate 20 of the first embodiment, the flexible substrate 22 is wound 2.5 turns in the circumferential direction so that the inner first surface F and the outer second surface S face each other. Simulation results have shown that a torque that is twice or more higher than that of an armature having a diameter can be expected.

FIG. 2 shows a coil arrangement of the coil substrate according to the first embodiment.
The coil substrate has seven coils C1 to C7 and terminals (commutators) T1 to T7 connected to the coils C1 to C7. The coil C1 is configured by a first coil CF including a first wiring 24F indicated by a solid line and formed on a first surface of the flexible substrate. The coil C2 is constituted by a second coil CS including a second wiring 24S indicated by a broken line formed on the second surface of the flexible substrate. The coil C3 includes a first coil CF including a first wiring 24F formed on the first surface of the flexible substrate. The coil C4 is configured by a second coil CS including the second wiring 24S formed on the second surface of the flexible substrate. The coil C5 includes a first coil CF including a first wiring 24F formed on the first surface of the flexible substrate. The coil C6 is configured by a second coil CS including the second wiring 24S formed on the second surface of the flexible substrate. The coil C7 includes a first coil CF including a first wiring 24F formed on a first surface of the flexible substrate.

The terminal T1 is connected to the coil C5 together with the coil C1. The terminal T2 is connected to the coil C6 together with the coil C2. The terminal T3 is connected to the coil C7 together with the coil C3. The terminal T4 is connected to the coil C1 together with the coil C4. The terminal T5 is connected to the coil C2 together with the coil C5. The terminal T6 is connected to the coil C3 together with the coil C6. The terminal T7 is connected to the coil C4 together with the coil C7. The coil C1 connected to the terminal T1 is connected to the terminal T4 via a second wiring 24S connected via a via conductor 24AD that falls at the end of the first wiring 24F arranged in a spiral shape. The coil C2 connected to the terminal T2 is connected to the terminal T5 via the first wiring 24F connected via the rising via conductor 24AU at the end of the spirally arranged second wiring 24S. The coil C3 connected to the terminal T3 is connected to the terminal T6 via the second wiring 24S connected via the falling via conductor 24AD at the end of the spirally arranged first wiring 24F. The coil C4 connected to the terminal T4 is connected to the terminal T7 via the first wiring 24F connected via the rising via conductor 24AU at the end of the spirally arranged second wiring 24S. The coil C5 connected to the terminal T5 is connected to the terminal T1 via the second wiring 24S connected via the falling via conductor 24AD at the end of the spirally arranged first wiring 24F. The coil C6 connected to the terminal T6 is connected to the terminal T2 via the first wiring 24F connected via the rising via conductor 24AU at the end of the second wiring 24S arranged in a spiral shape. The coil C7 connected to the terminal T7 is connected to the terminal T3 via the second wiring 24S connected via the via conductor 24AD which falls at the end of the spirally arranged first wiring 24F.

The coil C2 on the second surface S of the flexible substrate is arranged so that the coil C1 and the coil C3 on the first surface F of the flexible substrate partially overlap. The coil C4 on the second surface S of the flexible substrate is arranged so that the coil C3 and the coil C5 on the first surface F of the flexible substrate partially overlap. The coil C6 on the second surface S of the flexible substrate is arranged so that the coil C5 and the coil C7 on the first surface F of the flexible substrate partially overlap. Although C1 to C7 are illustrated for three turns in the drawing, they are formed for 35 turns in the embodiment. The via conductors 24AD and 24AU are made of copper plating penetrating the flexible substrate 22.

The inter-line distance (pitch) G1 of the spiral wirings 24F of the coil of the coil substrate of the first embodiment is formed at a narrow pitch of 0.002 mm or more and 0.5 mm or less. If the thickness is less than 0.002 mm, insulation cannot be secured. If it exceeds 0.5, narrow pitch cannot be realized. FIG. 5A is an explanatory diagram showing the areas of the outermost one-turn coil C11, the central one-turn coil C12, and the innermost one-turn coil C13 that constitute the coil C1. The area of the outermost one-turn coil C11 of the coil C1 is CE1, the area of the central one-turn coil C12 is CE2, and the area of the innermost one-turn coil C13 is CE3. According to the coil substrate of the first embodiment, since the line-to-line distance of the spiral wiring constituting the coil is narrow, the area CE2 of the center-side coil (one-turn coil C12) and (one-turn coil C13) Area CE3 is not reduced, and a small and high torque can be obtained. Coil C1, C3, C5, C7 formed of spiral first wiring 24F provided on first surface F of flexible substrate 22, and coils C2, C4 formed of second wiring 24S provided on second surface S. C6 is connected to via conductors 24AD and 24AU made of copper plating penetrating the flexible substrate 22. Therefore, unlike solder connection, it has high reliability, and high efficiency can be realized because current flows through the low-resistance via conductors 24AD and 24AU.

[Modification of First Embodiment]
FIG. 5B is an explanatory diagram showing the inner diameters of the outermost one-turn coil C11, the central one-turn coil C12, and the innermost one-turn coil C13 that constitute the coil C1. In the modification of the first embodiment, the gap GP1 between the outer one-turn coil C11 and the center one-turn coil C12, and the gap GP2 between the center one-turn coil C12 and the innermost one-turn coil C13 are set to be narrow. . The inner diameter of the central one-turn coil C12 is W2, and the inner diameter of the innermost one-turn coil C13 is W3. According to the coil substrate of the modified example of the first embodiment, since the spiral wiring constituting the coil has a narrow gap, the inner diameter W2 of the center-side coil (one-turn coil C12) and the inner diameter W2 of the (one-turn coil C13) The inner diameter W3 is not reduced, and a small and high torque can be obtained.

[Second embodiment]
FIG. 3 is an explanatory diagram illustrating a part of the coil of the coil substrate 20 according to the second embodiment. The hexagonal coil C1 is composed of 35 one-turn coils, and FIG. 3 shows three one-turn coils C11, C12, and C13. The first wiring 24F forming a half turn of the one-turn coil C11 is formed on the first surface F of the flexible substrate 22, and the second wiring 24S forming the remaining half turn is formed on the second surface S of the flexible substrate 22. ing. Similarly, one-turn coils C12 and C13 are formed. The one-turn coil C12 that is in contact with the one-turn coil C11 is arranged so as to be displaced from the one-turn coil C11 in the longitudinal direction of the rectangular coil substrate 20 described later. Similarly, the one-turn coil C13 is displaced from the one-turn coil C12.

4A is a schematic diagram illustrating a configuration of a coil of the coil substrate 20, FIG. 4B is a schematic diagram illustrating a cross-sectional shape of the coil of the coil substrate 20, and FIG. It is a top view.
The flexible substrate 22 has a first surface F and a second surface S opposite to the first surface.
The first wiring 24F forming a half turn of the hexagonal coil C1 is formed on the first surface F of the flexible substrate 22, and the second wiring 24S forming the remaining half turn is formed on the second surface S of the flexible substrate 22. The half-turn first wiring 24F and the remaining half-turn second wiring 24S are connected via via conductors 24A formed in the through holes 22a of the flexible substrate 22. The first wiring 24F, the second wiring 24S, and the via conductor 24A are formed by copper plating. Here, each of the coils C1 to C7 is formed so as to be spirally wound for 35 turns. In the first embodiment, 35 turns are formed. However, the number of turns is an example, and an arbitrary number of turns can be used.

As shown in FIG. 4B, the first wiring 24F on the first surface F side of the coil C1 partially overlaps the second wiring 24S on the second surface S side of the coil C2. Similarly, the first wiring 24F on the first surface F side of the coils C2 to C6 partially overlaps the second wiring 24S on the second surface S side of the coils C3 to C7.

As in the first embodiment, the coil substrate 20 having the coils C1 to C7 in which some of the wirings overlap is formed such that the inner first surface F and the outer second surface S of the flexible substrate 22 face each other. It is wound 2.5 turns in the direction (axial direction of the motor).

As shown in FIG. 4C, the width W1 of the coils C1 to C7 is 18 mm, and the circumferential length L1 of the width W1 of the coils C1 to C7 is 52.5 mm. The coils C1 to C7 are arranged at equal intervals. In the first embodiment, the coils are arranged at regular intervals. However, the coils can be arranged at irregular intervals.

According to the coil board of the second embodiment, the first wiring 24F constituting one half turn of the coil is formed on the first surface F side, and the second wiring 24S constituting the remaining half turn is formed in the second turn. It is formed on the side of the surface S, and is arranged such that adjacent turns are shifted. Since all the one-turn coils can be formed in the same size, a small and high torque can be obtained. That is, as shown in FIG. 3, since the inner diameter W21 of the one-turn coil C11, the inner diameter W22 of the one-turn coil C12, and the inner diameter W23 of the one-turn coil C13 can be increased, a high torque can be obtained. The first wiring 24F and the second wiring 24S provided on the first surface F and the second surface S of the flexible substrate 22 are connected by via conductors 24A made of copper plating penetrating the flexible substrate 22. Therefore, unlike the solder connection, it has high reliability, and high efficiency can be realized because current flows through the low-resistance via conductor 24A.

In the above-described embodiment, the coil substrate having seven coils is exemplified. However, the coil substrate of the embodiment can be configured as long as there are three or more coils.

DESCRIPTION OF SYMBOLS 10 Motor 20 Coil board 22 Flexible board 24A Via conductor 24F 1st wiring 24S 2nd wiring C1-C7 Coil T1-T7 Terminal

Claims (6)

A coil comprising a cylindrical flexible substrate having a first surface and a second surface opposite to the first surface, and a spiral wiring provided on the first surface and the second surface of the flexible substrate. And a via conductor made of copper plating that penetrates the flexible substrate and connects the wiring on the first surface and the wiring on the second surface,
The distance between the spiral wirings constituting the coil is 0.002 mm or more and 0.5 mm or less. A cylindrical flexible substrate having a first surface and a second surface opposite to the first surface, a coil comprising wiring provided on the first surface and the second surface of the flexible substrate, A coil substrate having a copper-plated via conductor that penetrates a flexible substrate and connects the first surface wiring and the second surface wiring,
One half turn of the coil is formed on the first surface side, and the other half turn is formed on the second surface side,
Adjacent turns are staggered. The coil substrate according to claim 1 or 2, wherein:
The flexible substrate is wound so as to exceed one rotation in the circumferential direction so that the inner first surface and the outer second surface face each other. The coil substrate according to claim 1,
A coil formed on the first surface;
And a coil formed on the second surface,
A part of the coil formed on the first surface and a part of the coil formed on the second surface are arranged to overlap. The coil substrate according to any one of claims 1 to 4, wherein the flexible substrate is wound twice or more. The coil substrate according to claim 1 or 2, wherein:
The coil is hexagonal.

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