JP2001210531A - Electrical component and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electrical component of a chip-shaped inductor or the like, that restrains heat damages to an insulating coating conductor by being electrically connected in a one time soldering process, and to provide its manufacturing method. SOLUTION: Lead wires 5, 5 are attached with both end parts of a drum core 1, the insulating coating conductor 6 is wound about this drum core 1, and both end parts are twined about the lead wires 5, 5 of both the end parts of the drum core 1, recessed parts 8 of lead frames 7, 7 for terminals are fitted together and attached with twined positions of lead wires 5, 5. A position, separated from the drum core 1 of this fitting parts, is heated by applying a laser beam, and then solder as a jointing material arranged in advance is fused. As a result, both the end parts of the insulating coating conductor 6, the lead wires 5, 5, and the lead frames 7, 7 for the terminals are electrically connected in batch and dispensed simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component for surface mounting and a method of manufacturing the same. More specifically, the present invention relates to a method for simultaneously conducting a lead wire of an axial lead type inductor and both ends of a winding and a plate-shaped terminal lead frame. The present invention relates to a chip-shaped inductor in which terminals other than terminals are covered with a resin mold and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a chip inductor in which an axial lead type inductor element and a plate-shaped terminal lead frame are joined by fitting and soldering, and covered with a resin mold to form a chip. FIG. 4 to FIG. 10 are diagrams for explaining a manufacturing process of such a chip inductor. Hereinafter, the structure and manufacturing method of the chip inductor will be described in detail. (1) As shown in the perspective view of FIG. 4 and the cross-sectional view of FIG. 5, flanges 2 are provided at both ends, and a recess 3 is formed at the center of the end face of each of the flanges 2. Lead wires 5 and 5 are attached to the concave portion 3 of the drum core 1 with an insulating adhesive 4. (2) As shown in FIG. 6, the insulated conductor 6 is wound around the drum core 1, and both ends of the insulated conductor 6 are respectively attached to the roots of the lead wires 5 across the flanges 2 and 2 of the drum core 1. After entanglement, as shown in FIG. 7, each lead wire 5, 5 is immersed in molten solder 12 to a root portion close to the flange portion 2 and soldered by immersion soldering or the like. (3) Next, as shown in FIG. 8, the lead wire 5 attached to the drum core 1 is insulated in the concave portion 8 (a receiving portion of the lead wire 5) of the separately prepared plate-shaped terminal lead frame 7. The solder of the lead wire 5 is melted by fitting at the root where the covered conductor 6 is entangled, and bringing the molten solder 16 into contact with the vicinity of the outside of the fitted portion via the roller-shaped iron 11. Each lead wire 5 and the terminal lead frame 7 are electrically conductively bonded together with the insulated conductor 6. (4) Next, as shown in FIG. 9, after removing extra parts of the lead wires 5, 5, as shown in FIG. The drum core 1 and the joint portion 14 that is conductively joined are molded into a chip shape with the resin 13, and the terminal portions of the pair of terminal lead frames 7, 7 are led out from the side surfaces of the molded resin 13 and then go downward. The chip-shaped inductor 20 is completed by being bent along the mold side surfaces and further bent along the mold bottom surface.

[0003]

However, in the conventional method of manufacturing the axial lead type chip-shaped inductor 20 described above, both ends of the insulated wire 6 across the flange 2 of the drum core 1 are connected to the root of the lead 5. At the same time as the soldering performed to join the conductor wires by entanglement, the conductor is immersed in a high-temperature molten solder in order to remove the insulation coating of the insulation-coated conductor wire 6. For this reason, there has been a problem that the insulation property of the insulation-coated conductor 6 (winding) wound around the drum core 1 is deteriorated due to heat damage due to heat conduction, and the yield is reduced.

Further, in the conventional manufacturing method, the above-mentioned soldering step of the insulated conductor 6 and the lead 5 is performed, and the lead frame 7 for the terminal and the lead wire fitted into the recess 8 of the lead frame 7 for the terminal are formed. In this case, it is necessary to perform a total of two soldering steps, that is, the soldering step with No. 5, and there is a problem that there are many heating steps that cause thermal damage to the drum core 1 and the insulated coated conductor 6.

The present invention has been made in consideration of the above circumstances, and requires only one bonding step of the electronic component which suppresses the influence of thermal damage to the drum core 1 and the insulated conductor 6 and the insulated conductor 6. And a method of manufacturing an electronic component which is less affected by thermal damage to the insulation-covered conductive wire 6 due to heat conduction.

[0006]

SUMMARY OF THE INVENTION The present invention provides: (1) a drum core having lead wires attached to both ends thereof;
An insulated conductive wire wound around the drum core and wound at both ends with lead wires at both ends of the drum core,
A terminal lead frame for connecting to an external circuit that is conductively bonded to the lead wire and the insulated conductive wire entangled with the lead wire; and the drum core is conductively bonded to the drum core except for a terminal portion of the terminal lead frame. In the electronic component for surface mounting, comprising: a resin mold for covering a conductor joining portion, wherein the conductor joining portion of the lead wire, the insulating covering conductor, and the terminal lead frame is collectively formed by laser irradiation. The above problem is solved by providing an electronic component. (2) As a method for manufacturing the electronic component, lead wires are attached to both ends of a drum core, and then an insulating coating wire is wound around the drum core, and both ends are connected to lead wires at both ends of the drum core. Each is tied to form a winding, and then a terminal lead frame for connecting to an external circuit is attached to a place where the insulating coated wire is tied to the lead wire, and then a place where the lead wire and the terminal lead frame are attached By applying laser irradiation to a position separated from the drum core and heating to melt the bonding material, the conductive bonding of the insulating coated lead wire, the lead wire, and the terminal lead frame is simultaneously performed, and then the excess portion of the lead wire And then covering the drum core and the conductive joint portion with a resin mold except for the terminal portion of the terminal lead frame. The above object is achieved by providing a method for manufacturing an electronic component characterized by the following.

[0007]

Embodiments of the present invention will be described with reference to the drawings. 1 to 3 are diagrams for explaining a method of manufacturing a chip inductor as an electronic component according to the present invention. In addition, the same code | symbol is shown about the member equivalent to FIGS. 4-10 explaining a prior art example.

As shown in FIG. 1, the method for manufacturing an electronic component according to the present invention comprises the steps of:
(See FIG. 4). Next, an insulated conductor 6 is wound around the drum core 1 and both ends are wound around the roots of the lead wires 5 at both ends of the drum core 1 to form windings. Then, the insulating coated conductor 6 is connected to the lead wire 5,
5 is fitted with a concave portion 8 of a terminal lead frame 7, 7 (for example, a thin plate made of phosphor bronze formed by punching press or the like) for connection to an external circuit. As shown in (2), attachment points (fitting portions) between the lead wires 5, 5 and the lead frames 7, 7 for terminals.
Laser irradiation (for example, irradiation of a circular laser irradiation unit 9 with a YAG laser) is applied to a position separated from the drum core and heated to form a plate-like solder pellet 10 as a bonding material previously arranged as shown in FIG. By melting, both ends of the insulated conductor 6, the lead wires 5, 5 and the terminal lead frames 7, 7 are simultaneously subjected to conductive bonding. Note that cream solder or powder solder (for example, a SnAg alloy having a particle size of about 75 μm) is used instead of the solder pellet 10.
Alternatively, solder plating obtained by electroplating at least the inner peripheral surfaces of the concave portions 8 of the lead frames 7 for terminals may be used as the joining material. In this case, the thickness of the solder plating is desirably 5 μm or more, preferably about 10 μm, from the viewpoint of securing the bonding strength. Of course, this solder plating may be applied to the entire terminal lead frame 7.

After conductive bonding, lead wires 5 and
5, the terminal portion is bent and a chip is formed through a process of covering the drum core and the conductive joint portion with a resin mold except for the terminal portions of the terminal lead frames 7, 7 as in FIG. The shape inductor is completed.

In the above-described method of manufacturing an electronic component according to the present invention, it is not necessary to immerse the solder between the both ends of the insulated conductor 6 and the leads 5,5, and the insulated conductor 6 and the lead are not required. Since the soldering of the wires 5 and 5 to the terminal lead frames 7 and 7 is a short-time (several milliseconds) output-controlled and high-energy heat input by the YAG laser, the insulated conductive wire wound around the drum core 1 is used. 6 can be suppressed (heat damage) and variations in bonding strength can be suppressed. Then, when the thermal damage of the insulated wire 6 of the electronic component actually manufactured by this manufacturing method and the electronic component manufactured through the conventional two heating steps is compared and observed, the superiority of the present invention is found. is there.

In the solder plating on the inner peripheral surface of the recess 8 of the terminal lead frame 7, the thickness can be controlled by the voltage and time of electroplating.
Has a merit of being easy to control the amount of solder as compared with the application of cream solder or the like.

Further, when the both ends of the insulated conductor 6, the lead wires 5, 5 and the terminal lead frames 7, 7 are collectively soldered, the temperature of the laser irradiation portion 9 instantaneously becomes high, so that the surface tension of the molten metal is increased. And there is an advantage that it is not necessary to use a flux (a metastatic agent) since the time for forming an oxide film is not given.

It should be noted that the YAG laser used for laser irradiation in the above embodiment is a solid-state laser widely used for the finest processing and the like using a YAG (abbreviation for yttrium / aluminum / garnet) crystal. It is. Alternatively, a ruby laser or a semiconductor laser may be used.

As the bonding material, solder is suitable as in the above embodiment, but other low melting point metals, for example, tin (S
n), an alloy of tin and copper (Sn—Cu), an alloy of tin and silver (Sn—Ag), silver (Ag), gold (Au), and the like can be applied.

[0015]

As described above, the electronic component and the method of manufacturing the same according to the present invention have the following excellent effects. (1) In the manufacturing method of the present invention, the laser irradiation is local and instantaneous, and the laser output and the irradiation time are appropriately set depending on the shape and size of the target joint and the joining material to be used. Since the irradiating location is instantaneous and limited to the vicinity of the fitting portion separated from the drum core, thermal damage to the insulated conductor is small, and good insulation is maintained. (2) Variations in bonding strength between both ends of the insulated conductor, the lead wire, and the terminal lead frame can be suppressed. (3) Further, since a cleaning step is not required and only one soldering step is required, efficiency in manufacturing control can be improved.

[Brief description of the drawings]

FIG. 1 is a view for explaining a method of manufacturing a chip-shaped inductor according to the present invention, in which a drum core wound with an insulated conductor and entangled with a lead wire is fitted into a concave portion of a terminal lead frame. It is a perspective view showing a state.

FIG. 2 is a plan view showing a state where laser irradiation is performed.

FIG. 3 is a side view showing a state where laser irradiation is performed.

FIG. 4 is a diagram for explaining a manufacturing process of a conventional axial lead type chip inductor, and is a perspective view showing a drum core and lead wires before lead wires are attached.

FIG. 5 is a cross-sectional view showing a state where a lead wire is attached to a drum core.

FIG. 6 is a side view showing a state where an insulated conductor is wound around a drum core and entangled with a lead wire.

FIG. 7 is a view in which a lead wire is immersed in molten solder and a tangled portion is subjected to immersion soldering processing.

FIG. 8 is a side view showing a state in which the solder of the lead wires is melted and the respective lead wires and the terminal lead frame are conductively joined together with the insulated conductor.

FIG. 9 is a side view of the axial lead type inductor main body after an extra portion of a lead wire is removed.

FIG. 10 is a schematic side view of the inside of a chip-shaped inductor completed by molding a resin and bending a terminal portion of a terminal lead frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drum core 2 Flange part 3 Concave part 4 Insulating adhesive 5 Lead wire 6 Insulating coating conductor (winding) 7 Terminal lead frame 8 Concave part 9 Laser irradiation part 10 Solder pellet 11 Roller-shaped iron 12 Melt solder 13 Resin 14 Joint part 16 Solder 20 Chip inductor

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[Procedure amendment]

[Submission date] January 28, 2000 (2000.1.2
8)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG. 2

FIG. 3

FIG.

FIG. 4

FIG. 5

FIG. 6

FIG. 7

FIG. 8

FIG. 9

FIG. 10

Continued on the front page F term (reference) 4E068 BA05 BH01 DA09 5E043 AA01 EA04 5E044 AD06 CA07 5E062 FG02 FG04 FG12 FG15

Claims (2)

[Claims] 1. A drum core having lead wires attached to both ends, an insulated conductive wire wound around the drum core and wound at the both ends with the lead wires at both ends of the drum core, and the lead wire. And a terminal lead frame for connecting to an external circuit conductively bonded to the insulation-covered lead entangled with the lead wire, and a conductive wire bonding portion conductively bonded to the drum core except for a terminal portion of the terminal lead frame. An electronic component for surface mounting, comprising: a resin mold for coating the lead wire, an insulating coating conductive wire, and a lead wire connecting portion of the terminal lead frame, which are collectively formed by laser irradiation. 2. A lead wire is attached to both ends of a drum core, and then an insulated conductor is wound around the drum core, and both ends are wrapped around lead wires at both ends of the drum core to form windings. A terminal lead frame for connecting to an external circuit is attached to a portion where the insulating coating wire is entangled with the lead wire, and then a laser is attached to a position where the lead wire and the terminal lead frame are attached away from the drum core. By irradiating and heating to melt the bonding material, conductive bonding of the insulating coated lead wire, the lead wire, and the lead frame for the terminal is simultaneously performed, and then, an excess portion of the lead wire is removed, and then the terminal for the terminal is removed. A method for manufacturing an electronic component, comprising a step of covering the drum core and the conductive joint part with a resin mold except for a terminal part of a lead frame.