JPS5868913A - Inductance element and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent any external electromagnetic induction and improve the mechanical stability, by surrounding both a core and a coil wound thereon with a resin molded layer containing a magnetic material, and securing the terminals of the coil to respective lead wires. CONSTITUTION:Ends of lead wires 6, 7 are inserted into holes formed in the centers of flange-like end surfaces of a ferrite drum-like core 1, respectively, and secured by means of a bonding agent. Then, a coil 9 is wound on the core 1 by an automatic winder, and at the same time, terminals 9a, 9b of the coil 9 are wound on the lead wires 6, 7, respectively. Subsequently, the terminals 9a, 9b and the lead wires 6, 7 are secured to each other by means of solder 10, respectively. Finally, a resin 11 containing an insulating magnetic material consisting of 90wt% ferrite powder of 150 mesh and 10wt% epoxy resin is molded so as to surround all the parts except for projecting parts 6a, 6b of the lead wires 6, 7. Thus, the coil 9 is made strong against a mechanical force. In addition, the effect of an external magnetic field can be shielded, since the coil 9 is surrounded by the resin 11 containing the magnetic material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inductance element that can downsize an electric circuit device and a method for manufacturing the same.

To attach the axial lead type inductance element, which is made by winding a drum core RTC*m to which a pair of lead wires are fixed, to the circuit board, the lead wires must be bent and inserted into the through holes of the circuit board. Therefore, not only is it troublesome to attach the circuit board to the circuit board, but it is also difficult to miniaturize the circuit device. There was also a risk that one winding would be cut when the lead wire was bent. In order to solve this type of drawback, various chip-type inductance elements have been proposed in which electrode layers or metal electrode members are arranged at both ends of the core, and the ends of the windings are connected to these electrode layers or metal electrode members. However, these devices have drawbacks such as complicated structures that make mass production difficult, and troublesome terminal processing.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an inductance element that can be easily mass-produced and is less susceptible to external induction, and a method for manufacturing the same.

A first invention of the present application to achieve the above object includes a drum-shaped or columnar core, and one and the other cores fixed to one and the other end face portions of the core and led out in the axial direction of the core. a lead wire, a winding wire that is wound around the core and whose one and other ends are connected to the one and the other lead wires, respectively, and the end surfaces of the one and the other lead wires are exposed. a molded resin layer containing an insulating magnetic material that covers the core, the winding wire, and the one and the other lead wires; one electrode layer electrically coupled to the end face of the lead wire;
An inductance characterized by comprising another electrode layer provided directly at least at the other end of the insulating Usuda material-containing resin molded layer and electrically coupled to the end face Km of the other lead wire. It is related to the element.

According to the present invention, the ends of the windings are fixed to the lead wires and are further surrounded by the resin molded layer containing K11B material. ) and can significantly improve reliability. Moreover, it becomes possible to provide the magnetic material-containing resin molded layer with a function as an exterior package, and it is possible to provide an element with high mechanical stability.

In addition, the pair of lead wires does not substantially protrude from both end surfaces of the element, and the electrode layer connected to the lead wires is used to electrically connect to the external circuit, making the circuit device compact and magnetic. Since the winding wire and the core are surrounded by the material-containing resin molding layer and a closed magnetic path is formed, the element has less electrical conduction from the outside. Furthermore, since it becomes a closed magnetic circuit, it is possible to obtain a large inductance value with a small size. Moreover, since the outer surface shape is simple, automatic supply and automatic attachment to a circuit board, etc., becomes easy.

The second invention of the present application relates to a method for manufacturing the above-mentioned inductance element, in which one and the other of the drum-shaped or columnar cores are led out in the axial direction of the core at the end face portions of the one and the other of the cores. fixing a lead wire, winding a winding around the core, and connecting one and the other ends of the winding to the one and the other leads lll1! winding around;
fixing one and the other ends of the windings wound around the one and the other lead wires to the one and the other lead wires with a conductive bonding material, and protruding a part of the one and the other lead wires. molding the core, the winding, the remaining parts of the one and the other lead wires, and the binding material with a resin containing an insulating straight material in such a state that the insulation obtained by the molding Cutting the one and the other lead wires protruding from one and the other end faces of the magnetic material-containing resin molding layer, the end faces of the one and the other lead wires, and the entire surface of the insulating magnetic material-containing resin molding layer. forming an electrode layer thereon by plating, at least on the end surfaces of the one and the other lead wires and the one and the other end surfaces of the insulating magnetic material-containing resin molded layer;
The present invention relates to a method of manufacturing an inductance element, which includes selectively removing the electrode layer while leaving the pole layer to form separated one and the other electrode layers.

According to the present invention, winding of the winding around the core and processing of the terminal where the lead wire is connected can be efficiently accomplished in the same manner as in the conventional axial lead type. Furthermore, since the protruding portions of the IJ leads are cut after the magnetic material-containing resin molded layer is provided, the lead 〇 end faces can be reliably exposed on both end faces of the magnetic material-containing resin molded layer. In addition, since the electrode layer is provided on the entire surface of the magnetic material-containing resin molded layer by plating and then separated into one and the other electrode layers, the one and the other electrode layers can be formed with high mass productivity. I can do it.

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

First, as shown in FIG.
Insert one and the other lead wire into the center hole +41 +51 of
61 (71) are inserted and fixed with adhesive (8) K to form a pair of lead wires +61 (71) led out in the axial direction of the core.
The diameter of + +31 is 2.2 m, the length from one end face to the other end face is 3.4 m, and the diameter of lead wire f61 +71 is 0.5 m.

Next, using an automatic winding machine, wind the winding (9) around the core jl+, and at the same time wind one and the other terminals (9a) (9b) around the lead wire +61 (71).This winding (9) and Terminal (
Windings 9a) and 9b are made using a pair of lead wires (61 (7)
1 as an axis, it can be easily achieved with an automatic winding machine.

Next, the terminals (9a) and (9b) are fixed to the respective lead wires +61 and +71 with solder (10) as a conductive bonding material.

Next, about 90 weight t% of 150 mesh ferrite powder,
A pair of lead wires (61 (71) protruding portion (6 (71)
Core (1), winding (9), lead wire (6)
Form a ferrite-containing resin acid 11υ so as to surround the remaining parts (6b) and (7b) of (7) and solder (1 It was formed into a cylindrical shape with a diameter of 2,51111 cm and a length of 5 cm using a transfer molding method.

Next, use a diamond cutter to cut a pair of lead wires +61
Cut the protruding parts (6m) (7m) of (7) from the root,
A pair of lead wires (6) as shown in Figures 3 and 4
The end face of (7) was exposed at the center of one and the other end faces (l1M) (llb) of the ferrite-containing resin molded layer aυ.

Next, the entire surface of the molded body shown in Figures 3 and 4 was coated with a nickel plating layer (approximately 1μ thick) by electroless nickel plating.
I3 was formed. At this time, the ferrite-containing resin molded layer α
Not only the surface of B, but also the pair of lead wires +6) +7)
A nickel plating layer α2 as an electrode layer is also formed on the end face of.

Next, a part of the nickel plating layer (13) on the outer peripheral surface of the cylinder was selectively removed by polishing with a diamond wheel, as shown in FIG. At the same time, as shown in FIG. 6, the nickel plating layer 17J is removed by polishing, and if necessary, a part of the ferrite-containing resin molded layer I is also removed by polishing as shown in FIG. Then, correct the inductance value.

The basic structure of the chip shop inductance element is completed through the steps up to Figure 6, but in this example, in order to make it easier to attach the inductance element to the circuit board, the nickel plating layer α shown in Figure 6 is By electrolytic nickel plating, a secondary nickel plating layer of approximately 2 μm (
12a) and then electrolytic solder plating to approximately 4μ
The inductance element tt is formed by forming a solder plating layer a3 of
Completed S.

When injecting the completed inductance elements A4 into the circuit board, they are arranged using a vibrator, etc., transferred one by one using a pipe, etc., and temporarily fixed to the circuit board (161 with adhesive U71, for example) as shown in Fig. 8. Then, solder u9 to the next busy wiring conductor u mallet.
The pair of electrode layers (14a) and (14b) are fixed together.

As is clear from the above, this embodiment has the following advantages.

Since the terminals (9m) and (9b) are not only easily processed, but also the terminals (9J1) and (9b) are tightly connected and protected, greatly improving reliability.

tbl Exterior body is ferrite-containing resin molded layer I7
)+7), a closed magnetic path is formed by this and the core (1), and the influence of electric fIi induction from the outside is reduced. Moreover, it becomes possible to obtain a large inductance value with a small size.

Since the circuit board is attached to the circuit board, the circuit lid can be made smaller.

ld) A pair of electrode layers (14 m) on a cylindrical molded body (
14b), there is little risk of damage even if the busy devices collide with each other during device transportation.

Moreover, the transfer can be accomplished smoothly and efficiently.

(・) As shown in Figure 2, a pair of lead wires (6) (
7) Ferrite-containing resin molded layer Uυ to protrude
After that, as shown in Fig. 3, the protrusion (6
When cutting 71), it becomes possible to more reliably expose the end face of l1(6) (71) to the end face (l1m) (llb).

(f) Electrode layers (14a) (14b) by plating
, the connection between the end ml of the lead wire +61 (7) and the electrode /* (Ha) (t4b) can be reliably achieved.

(g) A nickel plating layer U is formed on the entire surface by electroless plating, and then one and the other electrodes (14m) (14b) K are separated by polishing, so that the electrodes can be formed efficiently.

(h) When obtaining the pair of electrode layers (14Jl) (14b), it becomes possible to adjust the inductance value by polishing the ferrite-containing resin molded layer Uυ.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and can be further modified. Apply and lead! +61 (7) and core +13
The ferrite-containing resin molded layer υ may be provided after the bonding with the terminals (9a) and (9b) is further strengthened. In addition, a conductive adhesive may be used as a binding material instead of solder 110, and the composition of the ferrite-containing resin molded layer αυ may be, for example, 80 to 90% by weight of ferrite powder, 10 to 20% by weight of resin.
The weight percentage may be varied within a range, the magnetic material may be other than ferrite, and the resin may be a thermosetting or thermoplastic resin other than epoxy. Further, the ferrite-containing resin molded layer a1) ik, ) lance 7 may be formed by an injection molding method or the like other than the amolding method. However, it is preferable to make the molded layer Qυ by a molding method in which a fluidized ferrite-containing resin is pressed into a mold and solidified in the mold. (14b), as shown in FIG. 7, a primary nickel plating layer α2, a secondary nickel metal middle layer (12M), and a solder plating layer u3 are provided on the entire surface and then selectively polished to form a pair of electrodes. Layer (14a) (14
b) may be separated. Further, another plating layer of copper, silver, etc. may be formed instead of the solder plating layer.

Alternatively, the electrode layers (14a) (14b) may be formed by applying silver paste 7 and baking it. Furthermore, metal caps may be fitted onto the electrode layers (14a) (14b) as needed. Further, the core 111 may be formed into a columnar shape instead of a drum shape. In addition, ferrite-containing resin molded layer α
B may be formed into a prismatic shape instead of a cylindrical shape.

Furthermore, another paint may be applied on the ferrite-containing resin molded layer αυ.

[Brief explanation of the drawing]

Figures 1 to 9 show examples of the present invention. Figure 1 is a sectional view of an inductance element before molding, Figure 2 is a sectional view of an inductance element after molding, and Figure 3 is a lead. Figure 6 is a cross-sectional view of a state where a pair of electrode layers are formed, and Figure i@7 is a cross-sectional view of an inductance element with a solder plating layer formed. FIG. 8 is a partially cutaway front view showing the state in which it is mounted on a circuit board, and FIG. 9 is a sectional view showing the state in which the ferrite-containing resin molded layer has been polished. In the symbols used for the drawing buttons, tl+ is core,
(61 (71 is lead wire, (9) is winding wire, (9aX9b
) is the terminal, aα is the solder, aυ is the ferrite-containing resin molding layer, a2 is the nickel plating/-1 (14 is one electrode layer, (14q') & the other electrode layer. It depends on the agent Takano Vice. 1Figure 11 11

Claims (1)

[Scope of Claims] (11) A drum-shaped or columnar core; one and the other lead wires fixed to one and the other end face portions of the core and led out in the axial direction of the core; a winding wire which is wound and whose one end and the other end are connected to the one lead wire and the other lead wire, respectively; a molded resin layer containing an insulating magnetic material that covers the one lead wire and the other lead wire; one electrode layer that is coupled to the other electrode layer that is provided on at least the other end surface of the insulating magnetic material-containing resin molded layer and that is electrically coupled to the end INK of the other lead wire; An inductance element characterized by comprising: (2) fixing one and the other lead wires led out in the axial direction of the core to the end face portions of one and the other of the drum-shaped or columnar core; winding the core wire and winding one and the other ends of the winding around the one and the other lead wires; fixing the terminals to the one and the other lead wires with a conductive bonding material; The remainder of the bonding material and the insulating material
molding so as to be coated with a magnetic material-containing resin; cutting the one and the other lead wires protruding from one and the other end surfaces of the insulating magnetic material-containing resin molded layer obtained by the molding; forming an electrode layer by plating on the end surfaces of the one and the other lead wires and the entire surface of the resin molded layer containing the insulating magnetic material, at least the end surfaces of the one and the other lead wires and the entire surface of the resin molding layer containing the insulating magnetic material selectively removing the electrode layer while leaving the electrode layer on one and the other end surfaces of the resin molded layer to form separated one and the other electrode layers. Production method. (3) The method for manufacturing an inductance element according to claim 2, wherein forming the electrode layer by plating means forming a nickel plating layer. (4) Selectively removing the electrode layer is selectively removing the electrode layer by polishing.
The method for manufacturing an inductance element according to item 3 or 3fJ4.