JPH07115023A - Coil component - Google Patents

Abstract

PURPOSE:To facilitate the inspection of the soldering by making it possible to form solder fillets on the side surfaces of the edge parts of a core surely, at the time of mounting on a printed board. CONSTITUTION:External electrodes 12 are provided on the edge parts of a core ranging from its bottom to its sides. The end parts 5a, 5b, 6a and 6b of first and second wires are temporarily fixed on the external electrodes 12 by thermocompression bonding, and cream solder 15 is applied from above them. The surfaces of the cream solders 15 are flattened with a flat board 16 by shaping with heat and pressure.

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 or a transformer having a wire wound around a core.

[0002]

2. Description of the Related Art Conventional choke coils are shown in 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 end portions 5a, 5b, 6a, 6b of the wires 5, 6 are thermocompression-bonded to the electrode 3 provided on the collar portion 2 and temporarily fixed thereon. It is the one with solder. Each electrode 3 is provided from the bottom surface to the side surface of the collar portion 2 and has wire end portions 5a, 5b, 6a, 6
b is fixed to the bottom surface of the electrode 3. As shown in FIG. 9 (A), the electrode 3 is extended to the side surface so that the solder fillet 8 is formed on the side surface of the collar portion 2 when the soldering adhesiveness is improved and the choke coil is soldered on the printed circuit board 7. This is because it is possible to easily and visually confirm whether or not the soldering is performed and whether or not the soldering is reliably performed (good or bad solderability).

However, in the conventional choke coil shown in FIG. 7, for example, the end fixing portions of the wires 5 and 6 are raised, and when placed on the printed circuit board 7 as shown in FIG. A gap 9 is formed in the gap 9, the melted solder is sucked into the gap 9, and a fillet is not formed on the side surface of the collar portion 2 [see FIG. 9 (B)]. Further, in the choke coil shown in FIG. 10, a groove 2a is formed on the bottom surface of the collar 2 to eliminate the swelling of the fixed end portions of the wires 5 and 6. However, as shown in FIG. 11, when it is 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 Therefore, an object of the present invention is to ensure the formation of a solder fillet on the side surface of the collar portion when mounting on a printed circuit board, and to facilitate the inspection of solderability. To provide. In order to achieve the above object, in the coil component according to the present invention, the fixed portion of the wire end portion to the electrode provided on the flange portion is substantially flat. If the fixed part of the wire end is a flat surface,
When the coil component is placed on the printed circuit board, there is no gap between the printed circuit board and the bottom surface of the flange, solder suction is prevented, and the solder fillet is reliably formed on the side surface of the flange. Becomes

In order to make the fixed part of the wire end substantially flat, solder is applied to the electrode where the end of the wire is temporarily fixed, and the solder is heated and pressure-shaped. It is performed by pressure-shaping (crushing) the end portion of the wire, adhering a conductive plate material to an electrode where the end portion of the wire is temporarily fixed through a conductive adhesive, and the like.

[0006]

Embodiments of the coil component according to the present invention will be described below with reference to the accompanying drawings. In addition, 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. (First embodiment, see FIGS. 1 and 2) FIG. 1 shows a collar portion 11 provided at a lower portion of a core (a body portion is not shown) of a choke coil.
The electrodes 12 of the first and second wire ends 5a, 5b,
The steps of fixing 6a and 6b will be shown from the bottom side in the order of (A), (B), and (C). The electrodes 12 are respectively formed from the bottom surface to the side surfaces of the collar portion 11 by a thick film method by printing or 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 portion of each electrode 12 and is 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 the cream solder 15 is pressed by the flat plate 16 while heating or after heating [see FIG. 1 (B)]. With this, 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 end fixing portion of the wire becomes flat, and when this choke coil is placed on the printed circuit board, a gap is generated between the printed circuit board and the end fixing portion to suck up the solder. Therefore, the solder fillet is reliably formed on the side surface portion 12a (see FIG. 2) of the electrode 12. Therefore, it is easy to inspect the solderability at the time of mounting on the printed circuit board.

(Second Embodiment, see FIGS. 3 and 4) In the second embodiment, instead of the cream solder 15 used in the first embodiment, a preliminary solder 17 is used to replace the first solder and the second wire. Edge 5
a, 5b, 6a, 6b are applied on the temporarily fixed electrode 12, and the flat plate 16 is pressed while heating, and the preliminary soldering 1
The surface of 7 is pressed and shaped to be flat, and the wire end 5
A, 5b, 6a and 6b were also pressed to flatten them. For example, if the wire diameter is 0.1 mm, 0.05 mm
Crush up to flatten. Operation of the second embodiment,
The effect is similar to that of the first embodiment.

(Third Embodiment, FIGS. 5 and 6) In the third embodiment, the conductive plate material 19 is used for flattening, and the end portions 5a of the first and second wires are formed. , 5b, 6a, 6
A conductive adhesive 18 was applied on the electrode 12 on which b was temporarily fixed, and a conductive plate material 19 was pressure-bonded thereon. This plate material 19
Is a copper plate, for example, and will function as a frame terminal. The operation and effect of the third embodiment are similar to 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 gist thereof. In particular, the end fixing portion of the wire may be flattened to the extent that it is possible to prevent sucking up of the solder, and various flattening methods other than pressure shaping and plate material adhesion can be adopted.

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

[Brief description of drawings]

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

FIG. 2 is a sectional view of a main part of a choke coil completed by the process shown in FIG.

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

FIG. 4 is a cross-sectional view of essential parts of the choke coil completed by the process shown in FIG.

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

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

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

8 is a diagram showing a state in which the choke coil shown in FIG. 7 is placed on a printed board.

9A and 9B are diagrams showing a solder fillet formation state, 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 in which the choke coil shown in FIG. 10 is placed on a printed board.

[Explanation of symbols]

 5a, 5b, 6a, 6b ... Wire end 11 ... Collar 12 ... Electrode 15 ... Cream solder 17 ... Pre-solder 18 ... Conductive adhesive 19 ... Conductive plate material

Claims (4)

[Claims] 1. A coil component in which a plurality of electrodes are provided on a flange portion of a core from a bottom surface to a side surface of the core, and an end portion of a wire wound around the core is fixed to a bottom surface portion of the electrode. A coil component characterized in that the part is a flat surface. 2. The coil component according to claim 1, wherein solder is applied to an electrode where the end portion of the wire is temporarily fixed, and the solder is heated and pressure-shaped to form a flat surface. . 3. The surface of the wire is flattened by applying solder to an electrode where the end of the wire is temporarily fixed and heating and pressurizing the end of the solder and the wire. 1
Described coil parts. 4. The coil component according to claim 1, wherein a conductive plate material is adhered to the electrode, to which the end of the wire is temporarily fixed, via a conductive adhesive.