JP3097415B2 - Coil parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil component, and more particularly to a coil component such as a choke coil and a transformer having a core wound with a wire.

[0002]

2. Description of the Related Art Conventionally, as a choke coil, FIG.
The one shown in FIG. 10 was provided. These are Core 1
The first wire 5 and the second wire 6 are wound around, and the ends 5a, 5b, 6a, 6b of the wires 5, 6 are thermocompression-bonded to the electrode 3 provided on the flange portion 2 and temporarily fixed. Is soldered. Each electrode 3 is provided from the bottom surface to the side surface of the flange portion 2 and has wire ends 5a, 5b, 6a, 6
b is fixed to the bottom surface of the electrode 3. The reason why the electrode 3 is extended to the side surface is that, as shown in FIG. 9A, when the choke coil is soldered on the printed circuit board 7 and the solder fillet 8 is The purpose of this is to make it easy to visually check whether or not the soldering has been performed reliably (good or poor solderability).

However, in the conventional choke coil, for example, in the coil shown in FIG. 7, the end fixing portions of the wires 5 and 6 are raised, and as shown in FIG. A gap 9 is formed in the gap 9 and the melted solder is sucked into the gap 9 so that no fillet is formed on the side surface of the flange portion 2 (see FIG. 9B). In the choke coil shown in FIG. 10, a groove 2a is formed on the bottom surface of the flange portion 2 so as to prevent the end portions of the wires 5 and 6 from rising. However, as shown in FIG. 11, when placed on the printed circuit board 7, a gap 9 is generated, and the formation of the solder fillet is hindered as described above.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a coil component that ensures formation of a solder fillet on the side surface of a flange portion when mounted on a printed circuit board, and allows easy inspection of solderability. Is to provide. In order to achieve the above object, the coil component according to the present invention has a
Each electrode is a flat surface, and
Flatten the surface of the solder provided to fix the end of the ear
Was shaped. If the surface that substantially functions as an electrode surface during mounting is a flat surface, when the coil component is mounted on the printed board, no gap is generated between the printed board and the mounting surface , The suction of the solder is prevented, and the solder fillet is reliably formed on the side surface of the flange portion.

In order to make the fixed portion of the wire end substantially flat, a solder is applied to an electrode to which the wire end is temporarily fixed, and this solder is heated and pressurized. Pressing and shaping (crushing) also the end of the wire, bonding a conductive plate material to the electrode to which the end of the wire is temporarily fixed via a conductive adhesive, and the like.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a coil component according to an embodiment of the present invention. In the embodiments described below, the present invention is applied to a choke coil, and the same parts and portions are denoted by the same reference numerals in each drawing. FIG. 1 shows a flange 11 provided below a core of a choke coil (a main body is not shown).
Of the first and second wires 5a, 5b,
The steps of fixing 6a and 6b are shown from the bottom side in the order of (A), (B) and (C). The electrodes 12 are formed from the bottom surface to the side surfaces of the flange portion 11 by a thick film method by printing and baking a conductive paste, or a thin film method by vapor deposition, sputtering, or the like.

Each end 5a, 5b, 6a, 6b of the wire
Is first drawn out to the bottom surface of each electrode 12, temporarily fixed on the electrode 12 by thermocompression bonding, and unnecessary portions are cut. Next, the cream solder 15 is applied on the electrode 12 [see FIG. 1 (A)], and while heating or after heating, the cream solder 15 is pressed by the flat plate 16 [see FIG. 1 (B)]. Thus, the wire ends 5a, 5
b, 6a, 6b are embedded in the cream solder 15, and
The surface of the cream solder 15 becomes a flat surface [FIG. 1 (C),
See FIG. 2].

That is, the fixed portion at the end of the wire becomes flat, and when the choke coil is mounted on the printed circuit board, a gap is generated between the printed circuit board and the fixed portion at the end to suck up the solder. Therefore, the solder fillet is reliably formed on the side surface portion 12a of the electrode 12 (see FIG. 2). Therefore, it is easy to inspect the solderability at the time of mounting on a printed circuit board.

(Second Embodiment, see FIGS. 3 and 4) In the second embodiment, a spare solder 17 is used instead of the cream solder 15 used in the first embodiment, and the first and second wires are replaced. End 5
a, 5b, 6a, and 6b are applied onto the temporarily fixed electrode 12, and the flat plate 16 is pressed down while being heated.
7 is flattened under pressure and the wire end 5
a, 5b, 6a and 6b were also pressed to flatten. For example, if the diameter of the wire is 0.1 mm, 0.05 mm
Crush until flattened. The operation of the second embodiment,
The effects are the same as in the first embodiment.

(Third Embodiment, FIGS. 5 and 6) In the third embodiment, flattening is performed by using a conductive plate material 19, and ends 5a of first and second wires are provided. , 5b, 6a, 6
A conductive adhesive 18 was applied on the electrode 12 to which the b was temporarily fixed, and a conductive plate 19 was pressed thereon. This plate 19
Is a copper plate, for example, and functions as a frame terminal. The operation and effects of the third embodiment are the same as those of the first embodiment.

(Other Embodiments) The coil component according to the present invention is not limited to the above embodiment, but can be variously modified within the scope of the invention. In particular, it is sufficient that the end fixed portion of the wire is flattened to the extent that solder suction can be prevented, and various flattening methods other than pressure shaping and plate bonding can be employed.

Further, the present invention can be widely applied to transformers, inductors, etc. other than the choke coil, as long as the wire is wound around the core.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention and showing a step of fixing a wire end to an electrode of a flange.

FIG. 2 is an essential part cross-sectional view of the choke coil completed by the process shown in FIG. 1;

FIG. 3 is a perspective view showing a second embodiment of the present invention and showing a step of fixing a wire end to an electrode of a flange portion.

FIG. 4 is a sectional view of a main part of the choke coil completed by the process shown in FIG. 3;

FIG. 5 is a perspective view showing a third embodiment of the present invention and showing a step of fixing a wire end to an electrode of a flange portion.

FIG. 6 is a sectional view of a main part of the choke coil completed by the process shown in FIG. 5;

FIG. 7 is a perspective view showing an example of a conventional choke coil.

8 is a diagram showing a state where the choke coil shown in FIG. 7 is mounted on a printed circuit board.

9A and 9B are views showing a state of forming a solder fillet, FIG. 9A shows a good example, and FIG. 9B shows a bad example.

FIG. 10 is a perspective view showing another example of a conventional choke coil.

11 is a diagram showing a state where the choke coil shown in FIG. 10 is mounted on a printed circuit board.

[Explanation of symbols]

 5a, 5b, 6a, 6b ... wire end 11 ... flange 12 ... electrode 15 ... cream solder 17 ... spare solder 18 ... conductive adhesive 19 ... conductive plate

Claims (4)

(57) [Claims] 1. A plurality of electrodes are provided on a flange portion of a core from a bottom surface to side surfaces thereof, and an end of a wire wound around the core is attached to a bottom portion of the electrode.
In the coil component fixed using solder, the bottom surface of the flange portion is a flat surface, each of the electrodes is a flat surface, and the end of the wire is
The surface of the solder provided for fixing is shaped into a flat surface
Coil component to Being, a features. 2. The coil component according to claim 1, wherein solder is applied to the electrode to which the end of the wire is temporarily fixed, and the surface is flattened by heating and press-forming the solder. . 3. The method according to claim 1, wherein solder is applied to the electrode to which the end of the wire is temporarily fixed, and the end of the solder and the wire is heated and pressed to form a flat surface. 1
The described coil component. 4. The core flange extends from the bottom surface to the side surface.
A plurality of electrodes, and the ends of the wire wound around the core are
In the coil component fixed to the bottom portion of the electrode, the bottom surface of the flange portion is a flat surface, and a conductive adhesive is applied to each electrode to which the end portion of the wire is temporarily fixed.
A conductive plate material is adhered through the coil component.