JPH06333762A - Choke coil, method of manufacturing the same, and hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To provide a small choke coil with reduced manufacturing cost, in which a core is fixed in a winding coil easily and surely. CONSTITUTION:A magnetic core 13 is inserted in a winding coil 12. A pair of broad brimmed end parts 16a and 16b are formed on a pair of conductors 14a and 14b at both axial ends of the winding coil 12 in solder plating used for forming an electrode. Then, the inside part of the conductors 14a and 14b are enlarged in a diametrical direction, and the core 13 are supported on both ends by the pair of broad brimmed end parts 16a and 16b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a choke coil suitable for surface mounting on a substrate of a hybrid IC (hybrid integrated circuit), a method for manufacturing the same, and a hybrid integrated circuit. In particular, the core is fixed in the coil. The present invention relates to a choke coil improved in method, a manufacturing method thereof, and a hybrid integrated circuit.

[0002]

2. Description of the Related Art Conventionally, as an example of this type of choke coil, there is one having a structure as shown in FIG.
In this choke coil 1, a coated wire 2 is wound in a coil shape to form a winding coil 3, and a core 4 made of a magnetic material such as ferrite is densely inserted into the coil 3 to form a coil shown in FIG.
The core 4 is fixed in the coil 3 with the adhesive 5 as shown in FIG.

The electrode of the choke coil is formed in an annular shape by removing the coating of the conductive wire in order to prevent the inductance from decreasing due to the eddy current.

However, the choke coil 1 requires a step of applying the adhesive 5 on the outer peripheral surface of the core 4 or the inner peripheral surface of the coil 3 and a step of drying the adhesive, and the number of steps is reduced. There is a problem that the workability is increased and the workability is reduced.

Further, there is a problem that the electrical characteristics of the choke coil 1 may be adversely affected depending on the components of the adhesive 5 and that the adhesive strength may be deteriorated or lost due to deterioration over time of the adhesive 5. is there.

Therefore, in another conventional choke coil 6 shown in FIG. 7, the entire outer peripheral surface of the coil 8 is, for example, molded in a state where the core 7 is simply inserted without being fixed in the coil 8 with an adhesive. Core 7 covered with resin 9 by
Are fixed in the coil 8.

[0007]

However, in such a conventional choke coil 6 as described above, since the entire outer peripheral surface of the coil 8 is covered with the resin 9 having a prismatic shape, the cost increases due to an increase in the coating process. In addition, since the outer diameter size is increased, there is a problem that, for example, when mounting on a substrate of a hybrid IC, high density mounting is hindered.

The present invention has been made in view of the above circumstances, and its purpose is to make it possible to fix the core in the coil easily and reliably, and to reduce the cost. Coil and its manufacturing method,
And to provide a hybrid integrated circuit.

[0009]

The present invention is configured as follows in order to solve the above-mentioned problems.

The invention according to claim 1 of the present application (hereinafter, referred to as the first
Of the invention) has a winding coil formed by winding a coated wire in a coil shape, and a magnetic core inserted into the coil, and at least the outer surface of the coated wire at both axial ends of the coil. By removing a part of the coating on each side to expose the core material, a pair of reduced diameter end portions for reducing the inner diameter of the coil are formed by plating on the pair of exposed portions. It is characterized in that the core is clamped from both ends in the axial direction by the radial ends and fixed in the coil.

In the invention according to claim 2 of the present application (hereinafter, referred to as the second invention), the pair of reduced diameter end portions expand the wire diameter of the conductor wire at both ends of the coil in the coil inner diameter direction. It is characterized by being plated as described above.

Further, in the invention according to claim 3 of the present application (hereinafter referred to as the third invention), the pair of reduced diameter end portions are plated by removing at least a part of the coating of the conductive wire at both end portions of the coil. It is characterized in that it is formed integrally with the pair of electrode terminals thus formed.

Furthermore, the invention according to claim 4 of the present application (hereinafter referred to as the fourth invention) is obtained by mounting the choke coil according to any one of claims 1 to 3 on a substrate. Is characterized by.

The invention according to claim 5 of the present application (hereinafter referred to as the fifth invention) includes a step of inserting a magnetic core into a winding coil formed by winding a covered wire into a coil, and the coil. A step of removing at least a part of the coating on the both ends in the axial direction to expose a core member to form a pair of exposed portions, and form a pair of electrode terminals by plating. In the method of manufacturing a choke coil, during the plating step, a pair of reduced-diameter end portions that reduce the inner diameters of the coil end portions are formed by plating, and the pair of reduced-diameter end portions form both end portions of the core. It is characterized in that it is sandwiched in the coil.

The invention according to claim 6 of the present application (hereinafter referred to as the sixth invention) is characterized in that the plating is solder plating.

[0016]

[Operation] With a pair of reduced diameter end portions of both ends of the winding coil,
Since the core in the winding coil is sandwiched from the axial direction and fixed in the coil, the core can be fixed easily and surely without being adhered in the coil.

Further, since the pair of diameter-reduced ends can be formed at the same time in the solder plating process for forming the electrode terminals at both ends of the winding coil, the pair of diameter-reduced ends can be obtained without increasing the number of steps. The ends can be easily formed. Therefore, the manufacturing workability can be improved and the manufacturing cost can be reduced.

Furthermore, since the entire outer peripheral surface of the coil is not covered with a resin mold or the like, the size can be reduced. Therefore, when these choke coils are mounted on, for example, the substrate of a hybrid IC, these choke coils can be mounted with high density.

[0019]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5, the same or corresponding parts are designated by the same reference numerals.

FIG. 1 is a perspective view of an embodiment including the first and second inventions of the present application, and FIG. 2 is a longitudinal sectional view of FIG. The body core 13 is simply inserted tightly.

The core 13 is formed of a magnetic material such as ferrite into a solid columnar shape, and its axial length is slightly shorter than the axial length of the coil 12.

On the other hand, in the winding coil 12, a coated conductor 14 is wound in a coil shape, and at least a part of the insulating coating 14c on the outer surface side of each of the conductors 14a and 14b at both axial ends of the coil 12 is substantially formed. Removed over one turn, core material 14d
A part of the ring is exposed in an annular shape, and a pair of left and right annular exposed portions 15
a and 15b are formed.

The pair of annular exposed portions 15a,
A large-diameter end portion 16a, 16b that expands in the inner diameter direction is formed on the inner peripheral edge portion of 15b by solder plating, and the inner diameter is reduced by the pair of large-diameter end portions 16a, 16b. While the core is used as an electrode terminal, the core 14 in the coil 12 is sandwiched or locked from the axial direction to fix or lock the core 13 in the coil 12 and prevent the core 13 from falling out of the coil 12. It is supposed to do.

Next, an example of a method of manufacturing the choke coil 11 will be described.

First, the coated conductive wire 14 is wound into a coil to form a winding coil 12, and the insulating coating 14c on at least the outer surface side of the pair of conductive wires 14a and 14b at both axial ends of the coil 12 is removed. A part of the core material is exposed to form a pair of annular exposed portions 15a and 15b.

Next, the core 13 is densely inserted inside the coil 12 (air core).

After this, the pair of annular exposed portions 1 of the coil 12
A large-diameter end portion 16a, 16b is formed by subjecting the entire surface of 5a, 15b and the like to a base treatment such as nickel plating to facilitate solder plating, and then solder plating. The pair of large-diameter end portions 16a and 16b have their inner peripheral surfaces abutted on the outer peripheral edge portions of both ends of the core 13 to sandwich the core 13 from both ends thereof, and form the outer peripheral surface of the electrode terminal, or The lead wire is pulled out from the outer peripheral surface.

Therefore, according to this embodiment, the coil 12
Since the core 13 in the coil 12 is sandwiched from both ends in the axial direction by the pair of large-diameter end portions 16a and 16b at both ends of the core 13, the core 13 can be easily and reliably fixed in the coil 12.

Further, the pair of large-diameter end portions 16a, 16b are
Since it is formed in the conventional solder plating process for forming the electrode terminals, it is possible to prevent an increase in the number of processes, while FIG.
Since the adhesive 5 is not used unlike the choke coil 1 shown in (3), the bonding step can be omitted and the number of steps can be reduced. Therefore, the manufacturing workability can be improved and the cost can be reduced.

Further, the choke coil 11 of this embodiment is
Unlike the conventional choke coil 6 shown in FIG. 7, since the entire outer peripheral surface of the coil 8 is not covered with the resin 9 or the like, the size can be reduced. For this reason, this choke coil 1
When 1 is mounted on the substrate of the hybrid IC (not shown), high density mounting can be achieved.

FIG. 3 is a perspective view of an embodiment of the third invention of the present application, and FIG. 4 is a vertical sectional view of FIG. 3. In these drawings, a choke coil 21 is a pair of annular coils 12 of the above embodiment. A pair of annular flat plate-shaped electrode terminals 22a and 22b are formed on the exposed portions 15a and 15b by solder plating, and the core 1 is formed on the inner peripheral edge of the electrode terminals 22a and 22b.
3, the reduced diameter end portions 23a and 23b having a diameter smaller than the outer diameter of 3 are integrally formed by solder plating.
It is characterized in that both ends of the core 13 are sandwiched by a and 23b from the axial direction.

Therefore, as shown in FIG. 5 (A), the choke il 21 does not have the core 13 simply inserted into the coil 12 and is not fixed by an adhesive or the like.
As shown in (B), at both ends of the coil 12, both ends of the core 13 are sandwiched by the pair of reduced-diameter end portions 23a and 23b from the axial direction. Can be fixed.

The pair of reduced diameter end portions 23a and 23b are formed integrally with the electrode terminals 22a and 22b when the electrode terminals 22a and 22b are formed by solder plating, so that the number of steps is not increased. Rather, the conventional bonding process of the choke coil 1 shown in FIG. 6 can be omitted, so that the number of processes can be reduced.

Further, the choke coil 21 of the present embodiment.
Since the outer periphery of the coil 8 is not entirely covered with the resin 9 unlike the choke coil 6 shown in FIG. 7, the size can be reduced. For this reason, this choke coil 21
When mounted on a hybrid IC substrate or the like, high-density mounting can be achieved.

In the above embodiment, the case where the insulating coatings 14c on both ends of the coil 12 are removed over almost one turn has been described, but the present invention is not limited to this. For example, the insulating coatings 14c may be formed. A part of the wire diameters of the conductive wires 14a and 14b may be locally thickened by removing a part of the conductive wires 14a and 14b, and the shape of the electrode terminals 22a and 22b is not limited.

[0036]

As described above, according to the first to fifth inventions of the present application, the core in the coil is clamped and fixed by the pair of reduced-diameter end portions at both ends of the winding coil. It can be fixed easily and securely inside.

Since the pair of reduced diameter end portions are also formed by solder plating for forming the electrode terminals on both end portions of the coil, the choke coil can be manufactured without increasing the number of steps. In addition, it is possible to improve the manufacturing workability and reduce the cost.

Further, according to the present invention, since the outer peripheral surface of the coil is not covered with a resin mold or the like, it is possible to achieve miniaturization, and when mounting on the substrate of the hybrid IC, these choke coils are mounted at high density. be able to.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a choke coil including the first and second inventions of the present application.

FIG. 2 is a vertical cross-sectional view of FIG.

FIG. 3 is a perspective view of an embodiment of the third invention of the present application.

FIG. 4 is a vertical sectional view of FIG.

5A is a VA-VA arrow view of FIG. 4, and FIG. 5B is a side view of FIG.

FIG. 6A is a perspective view of a conventional choke coil,
(B) is a side view of the same (A).

FIG. 7 is a perspective view of another conventional example.

[Explanation of symbols]

 11,21 Choke coil 12 Winding coil 13 Core 14 Conductive wire 14a, 14b Conductive wire 14c at both ends 14c Insulation coating 14d Core material 15a, 15b Annular exposed portion 16a, 16b Large diameter end 22a, 22b Pair of electrode terminals 23a, 23b Pair of Reduced end

Claims (6)

[Claims] 1. A winding coil in which a coated wire is wound in a coil shape, and a magnetic core inserted into the coil, and at least an outer surface side of the coated wire at both axial ends of the coil. A part of the coating is removed to expose the core material, and a pair of reduced diameter ends for reducing the inner diameter of the coil are formed by plating on the pair of exposed portions. A choke coil characterized in that the core is clamped from both ends in the axial direction by end portions and fixed in the coil. 2. The choke coil according to claim 1, wherein the pair of reduced diameter end portions are plated so as to expand the wire diameter of the conductor wire at both ends of the coil in the inner diameter direction of the coil. 3. The pair of reduced diameter end portions are integrally formed with a pair of electrode terminals formed by plating by removing at least a part of the coating of the conductive wire at both end portions of the coil. The choke coil according to item 1. 4. A hybrid integrated circuit comprising the choke coil according to claim 1 mounted on a substrate. 5. A core material in which a magnetic core is inserted into a winding coil formed by winding a coated wire into a coil shape, and at least a part of the coating of the conductive wire at both axial ends of the coil is removed. A step of forming a pair of electrode terminals by plating each of a pair of exposed portions that are exposed to each other, and an inner diameter of both ends of the coil during the plating step. A method of manufacturing a choke coil, characterized in that a pair of reduced diameter end portions for reducing the diameter are formed by plating, and both ends of the core are sandwiched by the pair of reduced diameter end portions. 6. The choke coil according to claim 1, wherein the plating is solder plating, the manufacturing method thereof, or the hybrid integrated circuit.