JPH01161706A - Manufacture of small-sized choke coil - Google Patents

Abstract

PURPOSE:To obtain an inexpensive common mode small-sized choke coil which can be continuously manufactured in a mass production by aligning many lead terminal pieces each having a slit hole at the center on a reinforcing frame, aligning a plurality of bead cores, inserting fixedly them to the terminal pieces, integrally molding them, then cutting and shaping the terminal pieces. CONSTITUTION:A small-sized ferrite bead core 31 having a through hole, and groups of lead terminal pieces 34 disposed at a predetermined interval coupled at their roots by a reinforcing frame 32 are provided. A pectinated and 37 is formed in a sharp dovetail state, slit holes 37 for forming at least two signal wirings are formed at the center, the pieces 34 of thin stripelike metal plate plated with affine solderability are partly penetrated to the through hole of the core 31. Then, the pieces 34 are coated with adhesive, the pieces 34 are penetrated, positioned fixedly, integrally molded sealingly with electrically insulating resin 33, the pieces 34 of the part divided by the slit holes 37 of the pieces 34 are cut and shaped, and the divided pieces are respectively used as signal wirings.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a common mode F type small choke coil (hereinafter referred to as a small choke coil) which is used in a circuit board of a digital device and is integrally sealed and molded using an electrically insulating resin. ).

[Conventional technology]

Conventionally, this type of small choke coil has a structure including a small diameter ferrite bead core (hereinafter referred to as bead core) 11. as shown in FIG. Coated copper M12° lead terminal frame 13. First, the coated copper wire 12 is inserted into the bead core 11 for the required number of signal lines, and then the bead core 11 and the coated copper wire 1 are bonded together using an adhesive 15.
Fix 2. Next, the coated copper wire 12 is attached to the positioning piece 16 of the lead terminal frame 13 after shaping the lead, and the coating of the coated copper wire 12 is removed by thermal peeling or chemical peeling, etc. The lead terminal frame 13 is connected to the connection seat 17 by welding or soldering.

Next, the mold resin 14 is integrally sealed and molded with an electrically insulating resin, and the lead terminals are shaped to obtain a small choke coil.

The bead core 11 conventionally used in this type of small choke coil is usually a ferrite magnetic core, with a diameter of 1 to 3 mm, a through hole diameter of 0.4 to 1.0 mm, and a length of about 5 to 10 mm. A small diameter bead core is used, and the thickness of the through signal line is, for example, 0.1 to 0.
．． A coated copper wire with a thickness of 4 mm is used.

Therefore, it is necessary to penetrate several ultra-thin wires into a small-diameter bead core and fix them with adhesive.The work of penetrating and fixing the ultra-thin wires is very troublesome, and since several bead cores are usually used, it takes a lot of time to assemble. It took a lot of man-hours.

In addition, it is necessary to connect the wires to the lead terminal frame, and there is also the work of shaping and positioning the leads of the ultra-fine wires that have penetrated in advance, so conventional structures and manufacturing methods tend to increase processing costs. It had drawbacks.

[Purpose of the invention]

The present invention provides a lead terminal frame having a lead frame structure.
A large number of lead terminal pieces with arrowhead-shaped tips and slit holes for dividing each signal line are lined up in the center, and multiple bead cores are placed in front of each other, inserted into the lead terminal pieces as one piece, and fixed with resin.
Multiple bead cores are resin-molded together, and the molded resin part is cut and separated from the rear lead terminal frame to create a common-mode compact choke coil.It is an inexpensive common-mode compact choke coil that can be mass-produced continuously. The purpose is to provide choke coils.

[Structure of the invention]

In the present invention, the penetrating signal wire is a lead terminal piece made of a thin strip-shaped metal plate, the tip of which has a sharp arrowhead shape, the center part of which has a slit hole for dividing each signal wire, and the root part of the lead terminal piece that is made of a thin strip-shaped metal plate. They are connected by a reinforcing frame, and a large number of groups of lead terminal pieces are provided at regular intervals. After partially penetrating the lead terminal pieces into the bead core through holes and applying adhesive on the lead terminal pieces, further lead terminals are attached. Penetrate the piece, position it and fix it.

Next, after integrally sealing molded with an electrically insulating resin, the lead terminal pieces are cut and shaped in the portions separated by the slit holes of the lead terminal pieces to obtain a common mode type small choke coil.

〔Example〕

In FIG. 3, the shape and dimensions of the bead core 31 are, for example, an outer diameter of 2.5 mm, an inner diameter of 1-6 mm, and a length of 10.5 mm.
This is a cylindrical toroidal ferrite magnetic core, and the lead terminal piece 34 is made of a thin strip-shaped metal plate made of stainless steel, iron, phosphor bronze, or an alloy thereof, which is highly elastic and has a good conductivity. The parent solder has a surface treatment such as plating with tin or solder, and the tip of the insertion part 37° has a sharp arrowhead shape, and each lead terminal piece 3 is in the center.
Each lead terminal piece 34a is provided with a slit hole 36 for dividing it into 4a and 34b.

34b is provided with a positioning piece 35 protruding toward the outside, and furthermore, the base portion is connected to a reinforcing frame 32, and the reinforcing frame is provided with a large number of groups of lead terminal pieces 34 at regular intervals to form a comb shape, forming a chain lead frame. is formed. Further, positioning holes 38 are provided in the reinforcing frame 32 at regular intervals.

Now, as shown in FIG. 2, a plurality of bead cores 31 are arranged at a predetermined array pitch and held in a special jig, and the series of lead terminal pieces 34 are faced to each other, with the insertion portion 37 at the tip thereof exposed. Insert it into the bead core 31 while maintaining it at a predetermined arrangement pitch, apply an anaerobic adhesive or a heated room temperature curing adhesive onto the lead terminal pieces 34a, 34b, and insert it until the positioning piece 35 comes into contact with the bead core 31 for positioning. stick.

Next, the lead terminal pieces 34a and 34b, which are separated by the slit hole 36 of the lead terminal piece 34, are integrally sealed and molded with an electrically insulating resin such as epoxy resin, phenol resin, or 8MC resin, and are shaped into predetermined dimensions. The small choke coil of the present invention shown in FIG. 1 is obtained by cutting the wire into shapes and shaping the leads. In addition, by selecting the inner diameter of the through-hole of the bead core 31 and the dimensions of the lead terminal piece 34, the gap can be made smaller, and accidents such as movement of the bead core during sealing molding work can be avoided even if the adhesive 15 is not used. Therefore, the lead terminal pieces 34a and 34b can be sufficiently held.

FIG. 4 shows another embodiment according to the present invention. The lead terminal pieces 34 are four lead terminal pieces 34a, 34b, 34c.
, 34d, and when the lead terminal piece is inserted into the bead core, fixed to the bead core with resin, and separated into each lead terminal piece by sealing mold with resin, a small choke coil through which four signal lines pass can be constructed.

Furthermore, FIGS. 5(a), (b), and (c) show other shapes of the bead core constituting the present invention, and (a) shows a shape in which one ferrite core has a large number of through holes. The positions of the respective through holes and the positions of the lead terminal pieces shown in FIG. 2 correspond to each other, so that a plurality of small choke coils can be constructed with one bead core.

Figures 5(b) and 5(c) have bead cores whose through holes are not circular but oval, and are used when the lead terminal piece of Figure 4 has a large number of lead terminal pieces.

〔Effect of the invention〕

As explained above, according to the present invention, the signal wires penetrating into the microholes can be handled as a single signal wire insertion operation at once, and can also be inserted into multiple bead cores at once. Become.

Furthermore, the positions of the lead terminal piece and the bead core are accurately determined by the positioning piece, and the positions of the inserted signal lines are also accurately positioned.

Furthermore, there is no need to use any connection points on the signal lines. Therefore, the structural shape is simple and the number of parts can be reduced, and during assembly work, the insertion signal wires can be treated as a single line, and several bead cores can be inserted at once, making the assembly work easier. Man-hours can be significantly reduced.

Therefore, it has become possible to provide a small choke coil that is inexpensive, has stable quality, and is excellent in mass production.

Below margin

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of a small choke coil according to the present invention. FIG. 2 is an external view for explaining the present invention. FIG. 3 shows a bead core also used in the present invention. The figure which shows one example of a lead terminal piece. FIG. 4 is a diagram showing lead terminal pieces of other shapes. FIG. 5 is a diagram showing the shape of a ferrite bead core having another shape. FIG. 6 is an external perspective view of a conventionally used small choke coil. 11...Bead core. 12...Coated copper wire. 13...Lead terminal frame. 14...Mold resin. 15...Adhesive. 16...Positioning piece. 17...
Conjunction locus. 30...Chain lead frame. 31...Bead core. 32... Reinforcement frame. 33...Mold resin. 34, 34a, 34b, 34c, 34d...Lead terminal pieces. 35...Positioning piece. 36...Slit hole. 37・
...Insertion part. 38...Positioning hole. Figure 3 Figure 5 (G) Cb) <c) Figure 6

Claims (1)

[Claims] A small choke coil in which a signal line penetrates a small diameter ferrite bead core and is integrally sealed and molded with electrically insulating resin, includes a small diameter ferrite bead core having at least one through hole and a reinforcing frame at the base. A group of lead terminal pieces are provided at regular intervals by being connected to each other and hanging from the reinforcing frame, and the ends of the comb-shaped ends are formed in the shape of a sharp arrowhead, and a slit in the center for forming at least two signal lines. A lead terminal piece of a thin strip-shaped metal plate with a hole and plated with solderability is partially penetrated into the through hole of the small diameter ferrite bead core, an adhesive is applied onto the lead terminal piece, and an adhesive is applied onto the lead terminal piece. After the lead terminal piece is inserted, positioned and fixed, and integrally sealed and molded with electrically insulating resin, the lead terminal piece is cut and shaped in the portion divided by the slit hole of the lead terminal piece. A method for manufacturing a small choke coil having at least two signal lines passing through each divided lead terminal piece as one signal line.