JP2948966B2 - Electronic component and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to surface mount electronic components and
More particularly, the present invention relates to a chip type inductor in which a lead wire of an axial lead type inductor is joined to a plate-like lead frame for external terminals, and portions other than the external terminal portions are covered with a resin mold, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Chip-type inductors in which a wire-wound inductor is molded with a resin and a terminal portion is led out are used for various purposes.

Conventionally, a lead wire of an axial wound inductor is processed into a flat plate, and the flat lead wire portion is led out of the mold and bent along the mold. Since the width of the lead wire cannot be obtained simply by processing the lead wire into a flat plate shape, a lead frame for a plate-shaped terminal (hereinafter referred to as a plate-shaped lead frame) as a separate component is joined to the lead wire, and the joining with an external circuit is performed. A chip type inductor using a plate-shaped lead frame has been proposed.

FIGS. 2 to 7 are views for explaining a manufacturing process of such a chip-type inductor. With reference to these, the manufacturing process including the soldering of the lead wire and the winding, and the lead wire and the plate-shaped lead frame will be described below. (1) has a flange 2 on both ends, and respectively to the central portion recess 3 is attached to the lead wire 4 to the recess 3 of the drum core 1 formed of an insulating adhesive (Fig. 2 mounting leads of the flange surface FIG. 3 is a perspective view of the drum core and the lead wire before, and FIG. 3 is a cross-sectional view of the drum core after the lead wire is attached. (2) The winding 5 is applied to the drum core, the end of the winding 5 is wrapped around the end of the lead wire 4 across the brim of the core, and soldered by immersion soldering or the like (see the side view in FIG. 4 ). ). (3) A cream solder is attached to the concave portion 7 of the plate lead frame 6 for external connection prepared separately, and the lead wire 4 of the drum core is set in the concave portion 7 and reflow soldered (FIG. 5 ).
). (4) Next, after cutting the extra part of the lead wire (see
6 ), as shown in the side view of FIG. 7 , a pair of plate-shaped lead frames 6 are led out to the outside from the bottom surface of the resin mold 8 and molded therefrom toward the respective ends of the mold. Each is bent along the bottom surface, and further, at each end, is bent upward in an L-shape along the end surface of the mold.

[0005]

However, in the conventional manufacturing method, the solder is used to join the winding to the lead wire 4 where the end of the winding 5 is entangled across the flange 2 of the drum core 1. It is necessary to perform the soldering twice, once each for the attachment and the soldering of the lead wire 4 set in the concave portion 7 of the plate-shaped lead frame 6 and the lead frame 6, respectively. There was a problem that the number of processes increased.

[0006] Accordingly, an object of the present invention is obtained by simplifying and once the soldering twice in the manufacturing process
An object of the present invention is to provide an electronic component and a manufacturing method thereof .

[0007]

Means for Solving the Problems The present inventors have developed the above-mentioned object.
As a result of research to achieve the target, the end of the winding was entangled with the lead wire.
The winding method when shaking should be dense, sparse,
By adjusting the ratio of this density to three stages,
Control the amount of solder supplied to these
Solder that is arranged in the same way as above with the plate-shaped lead frame
If used, reflow soldering or
Process by solder heating and soldering at the same time.
The inventors have found that the simplification can be made, and arrived at the present invention.

[0008] Accordingly, the present invention is fitted with a lead wire at both ends of the drum core to first, subjected to a wound on the drum core, tying the two ends of the winding to the lead wire attached to both ends of the drum core, the lead After joining the lead frame for the terminal to be connected to the external circuit to the wire, the drum core and the joint between the drum core and the lead wire of the lead frame are made of resin except for the terminal portion for connecting the lead frame to the external circuit. electronic component der for surface mounting comprising coated with mold
Therefore, the step of sparseness and denseness is applied to the part where the winding end is connected to the lead wire.
The actual amount characterized by providing and controlling the amount of solder
Secondly, electronic parts to be worn; secondly, a lead wire is attached to both ends of the drum core, a winding is applied to the drum core, and both ends of the winding are entangled with the lead wires attached to both ends of the drum core. After joining the lead frame for the terminal to be connected to the circuit, the drum core and the joint portion between the drum core and the lead wire of the lead frame are covered with a resin mold, except for the terminal portion for connecting the lead frame to the external circuit. In the method of manufacturing a surface-mount electronic component, when the ends of the windings are entangled with the lead wire, the ends of the lead wire are sparsely entangled at a position closest to the drum core, and then sparsely entangled,
Finally, after tightly entangled, solder to the end of the lead wire having these sparse and dense windings, with the terminal lead frame in contact with the soldered part of the winding and the lead. And a method for manufacturing a surface-mount electronic component characterized by reflow soldering.

[0009]

According to the method of the present invention, the amount of solder used for soldering the terminal portion of the winding and the lead wire is controlled,
Since it is used for soldering the lead wire and the plate-shaped lead frame in the next process, there is no need to apply a new process such as applying cream solder to the lead frame.
Since the number of times is enough, the amount of solder can be easily controlled in manufacturing control.

[0010]

DETAILED DESCRIPTION FIG. 1 in this embodiment, re the ends of the windings
FIG. 7 is a side view showing how to entangle the lead wire, and the manufacturing process will be described below with reference to this . (1) First, a plate-shaped lead frame 6 as shown in FIG. 5 is formed by a punching press or the like. (2) The lead wire 4 is attached to the concave portion 3 formed on the surface of the flange 2 at both ends of the drum core 1 which is the axial lead type inductor body manufactured in a separate process with an insulating adhesive (see FIGS. 2 and 3). ). (3) Next, as shown in FIG. 4, when the winding 5 is applied to the other lead wire from one lead wire across the drum core 1,
By changing the feed speed of the machine,
Provide a density step. Specifically, the drum core of the lead wire 4
A. From the side closer to 1, shown at 11 and 12 in FIG.
First, tightly entangled, then sparsely, and finally tightly entangled
I can. (4) Next, soldering is performed on these windings in the sparse and dense state
You. Although the amount of solder is large and small due to the density of windings,
Because it can be controlled. (5) Next, after cutting excess lead wires, the inductor main body is placed in the concave portion 7 of the plate-shaped lead frame 6. (6) After joining the axial lead type inductor body and the plate-shaped lead frame 6 by reflow soldering,
As shown in FIG. 7, the inductor main body and the connection between the main body and the plate-shaped lead frame 6 are covered with an insulating resin mold 8. (7) The lead frame 6 led out of the molded body is bent to form external connection terminals for surface mounting.

[0011]

As described above, according to the method of the present invention, the manufacturing process can be shortened and the amount of solder as a bonding agent can be easily controlled.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of the present invention, in which a winding end is wound on a lead wire in each lead wire connected to a concave portion of a flange surface of a drum core. FIG.

FIG. 2 is a perspective view showing a drum core and lead wires before lead wires are attached in a manufacturing process of a conventional axial lead type inductor.

FIG. 3 is a schematic cross-sectional view showing a state where the lead wire of FIG. 2 is coupled to a concave portion of a drum core flange surface.

FIG. 4 is a side view showing a state in which the drum core and the lead wires of FIG. 3 are wound.

FIG. 5 is a perspective view of a state in which a wound drum core and a lead wire are to be set on a plate-shaped lead frame.

FIG. 6 is a side view showing a state in which a wound drum core and lead wires are set on a plate-shaped lead frame.

FIG. 7 is a schematic side view of a conventional axial lead type inductor completed by resin-molding the plate-shaped lead frame and the drum core lead wire assembly of FIG. 6 and then bending the plate-shaped lead frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drum core 2 Drum core flange part 3 Recess of flange surface 4 Lead wire 5 Winding 6 Plate-shaped lead frame 7 Recess of lead frame 8 Resin mold 11 Sparsely wound winding part 12 Densely wound winding part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01F 15 / 02,15 / 10 H01F 27 / 28,41 / 10

Claims (2)

(57) [Claims] 1. A lead wire is attached to both ends of a drum core, a winding is applied to the drum core, and both ends of the winding are tied to the leads attached to both ends of the drum core, and the leads are connected to an external circuit. After joining the lead frame for the terminal, the drum core and the joint between the drum core and the lead wire of the lead frame are covered with a resin mold, except for the terminal portion for connection to the external circuit of the lead frame.
Comprising a surface mount electronic component, the winding end of the lead
Controls the amount of solder by providing a sparse / dense stage at the wire entanglement
An electronic component for surface mounting, characterized in that: 2. A lead wire is attached to both ends of the drum core, a winding is applied to the drum core, and both ends of the winding are tied to the leads attached to both ends of the drum core, and the leads are connected to an external circuit. After mounting the terminal lead frame for bonding, the surface of the lead frame is covered with a resin mold except for the drum core and the joining portion between the drum core and the lead wire of the lead frame except for the terminal portion for connecting to the external circuit of the lead frame. In the method of manufacturing electronic components for electronic devices, when the ends of the above windings are entangled with the lead wire, the ends of the lead wire are entangled densely at a position closest to the drum core, then sparsely entangled, and finally tightly entangled. After soldering, solder to the terminal end of the lead wire having these densely wound windings.In this case, reflow soldering with the terminal lead frame in contact with the soldered part of the winding and the lead wire A method for manufacturing an electronic component for surface mounting, characterized by attaching.